This paper reviews the applications of the multi degree-of-freedom(MDOF)equivalent linear system in seismic analysis and design of planar steel and reinforced concrete framed structures.An equivalent MDOF linear struc...This paper reviews the applications of the multi degree-of-freedom(MDOF)equivalent linear system in seismic analysis and design of planar steel and reinforced concrete framed structures.An equivalent MDOF linear structure,analogous to the original MDOF nonlinear structure,is constructed,which has the same mass and elastic stiffness as the original structure and modal damping ratios that account for the effects of geometrical and material nonlinearities.The equivalence implies a balance between the viscous damping work of the equivalent linear structure and that of the nonlinearities in the original nonlinear structure.This work balance is established with the aid of a transfer function in the frequency domain.Thus,equivalent modal damping ratios can be explicitly determined in terms of the period and deformation levels of the structure as well as the soil types.Use of these equivalent modal damping ratios can help address a variety of seismic analysis and design problems associated with planar steel and reinforced concrete framed structures in a rational and accurate manner.These include force-based seismic design with the aid of acceleration response spectra characterized by high amounts of damping,improved direct displacement-based seismic design and the development of advanced seismic intensity measures.The equivalent modal damping ratios are also utilized in the context of linear modal analysis for the definition and construction of the MDOF response spectrum.Furthermore,the equivalent modal damping ratios are employed in a seismic retrofit method for steel-framed structures with viscous dampers.Finally,it is demonstrated that modal behavior(or strength reduction)factors can be easily constructed based on these modal damping ratios for a more rational and accurate force-based seismic design,including the determination of inelastic displacement profiles.展开更多
Background and Objective: HIV, hepatitis B virus (HBV) and hepatitis C virus (HCV) are very widespread in the world, however, less than 20% of the people affected are diagnosed and treated. This study aimed to determi...Background and Objective: HIV, hepatitis B virus (HBV) and hepatitis C virus (HCV) are very widespread in the world, however, less than 20% of the people affected are diagnosed and treated. This study aimed to determine the prevalence of HIV, HCV and HBV co-infections in pregnant women at Bangui Community University Hospital and the cost of screening. Methods: A cross-sectional study involving consenting pregnant women who came for antenatal care was performed. HIV, HCV antibodies and HBV antigens were detected using Exacto Triplex<sup>?</sup> HIV/HCV/HBsAg rapid test, cross-validated by ELISA tests. Sociodemographic and professional data, the modes of transmission and prevention of HIV and both hepatitis viruses were collected in a standard sheet and analyzed using the Epi-Info software version 7. Results: Pregnant women aged 15 to 24 were the most affected (45.3%);high school girls (46.0%), and pregnant women living in cohabitation (65.3%) were the most represented. Twenty-five (16.7%) worked in the formal sector, 12.7% were unemployed housewives and the remainder in the informal sector. The prevalence of HIV, HBV, and HCV viruses was 11.8%, 21.9% and 22.2%, respectively. The prevalence of co-infections was 8.6% for HIV-HBV, 10.2% for HIV-HCV, 14.7% for HBV-HCV and 6.5% for HIV-HBV-HCV. All positive results and 10% of negative results by the rapid test were confirmed by ELISA tests. The serology of the three viruses costs 39,000 FCFA (60 Euros) by ELISA compared to 10,000 FCFA (15.00 Euros) with Exacto Triplex<sup>?</sup> HIV/HCV/AgHBs (BioSynex, Strasbourg, France). Conclusion: The low level of education and awareness of hepatitis are barriers to development and indicate the importance of improving the literacy rate of women in the Central African Republic (CAR). Likewise, the high prevalence of the three viruses shows the need for the urgent establishment of a national program to combat viral hepatitis in the CAR.展开更多
A numerical analysis of the log-law behavior for the turbulent boundary layer of a wall-bounded flow is performed over a flat plate immersed in three nanofluids(Zn O-water,SiO_(2)-water,TiO_(2)-water).Numerical simula...A numerical analysis of the log-law behavior for the turbulent boundary layer of a wall-bounded flow is performed over a flat plate immersed in three nanofluids(Zn O-water,SiO_(2)-water,TiO_(2)-water).Numerical simulations using CFD code are employed to investigate the boundary layer and the hydrodynamic flow.To validate the current numerical model,measurement points from published works were used,and the compared results were in good compliance.Simulations were carried out for the velocity series of 0.04,0.4 and 4 m/s and nanoparticle concentrations0.1% and 5%.The influence of nanoparticles’ concentration on velocity,temperature profiles,wall shear stress,and turbulent intensity was investigated.The obtained results showed that the viscous sub-layer,the buffer layer,and the loglaw layer along the potential-flow layer could be analyzed based on their curving quality in the regions which have just a single wall distance.It was seen that the viscous sub-layer is the biggest area in comparison with other areas.Alternatively,the section where the temperature changes considerably correspond to the thermal boundary layer’s thickness goes a downward trend when the velocity decreases.The thermal boundary layer gets deep away from the leading edge.However,a rise in the volume fraction of nanoparticles indicated a minor impact on the shear stress developed in the wall.In all cases,the thickness of the boundary layer undergoes a downward trend as the velocity increases,whereas increasing the nanoparticle concentrations would enhance the thickness.More precisely,the log layer is closed with log law,and it is minimal between Y^(+)=50 and Y^(+)=95.The temperature for nanoparticle concentration φ=5%is higher than that for φ=0.1%,in boundary layers,for all studied nanofluids.However,it is established that the behavior is inverted from the value of Y^(+)=1 and the temperature for φ =0.1% is more important than the case of φ =5%.For turbulence intensity peak,this peak exists at Y^(+)=100 for v=4 m/s,Y^(+)=10 for v=0.4 m/s and Y^(+)=8 for v=0.04 m/s.展开更多
TheⅡ-Ⅵbased magnetic semiconductors with a direct and wide optical bandgap are expected to show high potential for optical applications utilizing short wavelength laser diodes(LDs),such as 532-nm green and475-nm blu...TheⅡ-Ⅵbased magnetic semiconductors with a direct and wide optical bandgap are expected to show high potential for optical applications utilizing short wavelength laser diodes(LDs),such as 532-nm green and475-nm blue LDs.We have confirmed that the Faraday rotationθ_F in the ZnMnTe and ZnMnSe films deposited on quartz glass(QG)and sapphire(SA)substrates by using molecular beam epitaxy(MBE)is large near the absorption edge.This paper reports the magneto-optical properties of ZnMnTe and ZnMnSe films synthesized on the QG and SA substrates,and shows the result of a direct Faraday rotation observation successfully made for the ZnMnTe films under 1.28-kHz alternating magnetic fields.The optical absorption characteristics of the ZnMnTe films grown on the SA substrates by MBE are discussed by comparing them with the optical absorption properties and photoluminescence spectra of theⅡ-ⅥZnTe parent single crystals.展开更多
Flat foot in children is a common deformation, which appears during the first years of life. It requires a rigorous evaluation to rule out congenital or neurological abnormality. It is characterized by a decrease of t...Flat foot in children is a common deformation, which appears during the first years of life. It requires a rigorous evaluation to rule out congenital or neurological abnormality. It is characterized by a decrease of the plantar concavity indeed collapse of the foot, often associated with other morphostatic deformations. The aim of this study is to find a correlation between the essential flat foot in children and lower limb disorders torsional. It is a cross-sectional descriptive study, recruiting 110 children (220 feet) aged between 3 and 6 years old. Each child was given an assessment of the morphology of the foot (Contact Index II…) and lower limb rotational profile (intoeing and femoral antétorsion and tibal torsion). Among 110 children, 21 (19.1%) have bilateral flat feet and 7 (6.4%) have unilateral flat feet, associated with an average value of Contact Index II equal to 0.921;the minimum value is 0.880 and the maximum value is 1.17. All children with flat feet have excessive femoral antétorsion;45 (92%) are associated with a hip intoeing and 38 (80%) present an insufficient external tibial torsion. The analysis of multiple regression shows a significantly elevated correlation among the flat foot and excessive internal rotation of the hip (F = 70.36, r = 0.77, P < 0.001), excessive femoral antetorsion (F = 54.78, r = 0.73, P < 0.001) and insufficient external tibial torsion (F = 7.79, r = 0.37, P < 0.001).展开更多
The quality traits of fresh marketable chicken eggs collected during winter, autumn and summer periods from different local markets in Lebanon were evaluated in order to understand the reproductive fitness of the chic...The quality traits of fresh marketable chicken eggs collected during winter, autumn and summer periods from different local markets in Lebanon were evaluated in order to understand the reproductive fitness of the chicken and the correlation between collection dates. A total of 2000 brown and white eggs were analyzed and compared for their external quality parameters such as egg weight, length, width, size, shell thickness, specific gravity and for their internal quality traits such as Haugh unit, yolk diameter, yolk color, and yolk height. Results show that egg weight and size varied markedly and tended to be smaller during summer period. A significant difference was found between white and brown eggs in some quality traits such as egg weight, shell thickness, egg length, and yolk diameter parameters. Egg quality parameters were significantly reduced during summer season where eggs are exposed to high temperature conditions. For grading analysis, 80% of the total eggs were classified as A with a significant difference (p < 0.05) between white and brown egg and during collection dates. Overall, brown eggs graded better than white eggs in external quality cleanliness and shape. Based on our analysis, the results of this study show that Lebanese eggs are of good quality and suggest that proper egg handling and storage conditions should be applied especially at warm environmental conditions to improve egg quality during summer season.展开更多
It is believed that mechanical stimuli, such as stretching of the extracellular matrix, are transmitted into cells via focal adhesion complexes and the actin cytoskeleton. Transmission dynamics of strain from the extr...It is believed that mechanical stimuli, such as stretching of the extracellular matrix, are transmitted into cells via focal adhesion complexes and the actin cytoskeleton. Transmission dynamics of strain from the extracellular matrix into intracellular organelles is crucial to clarify the mechanosensing mechanisms of cells. In this study, we observed deformation behavior of actin stress fibers under uniaxial stretch using an originally developed cell-stretching microelectromechanical system (MEMS) device. It was difficult to conduct in situ observation of cells under stretch using conventional cell stretching devices, because motion artifacts such as rigid displacement during stretch application were not negligible. Our novel cell-stretching MEMS device suppressed rigid displacement while stretching, and we succeeded in obtaining time-lapse images of stretched cells. Uniaxial strain with a 10% magnitude and strain rate of 0.5%/sec was applied to cells. Deformation behaviors of the cells and actin stress fibers were recorded using a confocal laser scanning microscope. In time-lapse images of stretched cells, strains along each stress fiber were measured manually. As a result, in cells with a relatively homogeneous stress fiber structure oriented in one direction, distribution of the axial strain on stress fibers generally corresponded to deformation of the stretching sheet on which the cells had adhered. However, in cells with a heterogeneous stress fiber structure oriented in several directions, we found that the strain distribution along stress fibers was not homogeneous. In regions around the cell nucleus, there was a more complicated strain distribution compared with other regions. Our results suggest the cell nucleus with a stiff mechanical resistance yields such a complicated strain distribution in stress fibers.展开更多
We investigate the dynamics of entanglement through negativity and witness operators in a system of four noninteracting qubits driven by a classical phase noisy laser characterized by a classical random external field...We investigate the dynamics of entanglement through negativity and witness operators in a system of four noninteracting qubits driven by a classical phase noisy laser characterized by a classical random external field(CREF).The qubits are initially prepared in the GHZ-type and W-type states and interact with the CREF in two different qubit-field configurations,namely,common environment and independent environments in which the cases of equal and different field phase probabilities are distinguished.We find that entanglement exhibits different decaying behavior,depending on the input states of the qubits,the qubit-field coupling configuration,and field phase probabilities.On the one hand,we demonstrate that the coupling of the qubits in a common environment is an alternative and more efficient strategy to completely shield the system from the detrimental impacts of the decoherence process induced by a CREF,independent of the input state and the field phase probabilities considered.Also,we show that GHZ-type states have strong dynamics under CREF as compared to W-type states.On the other hand,we demonstrate that in the model investigated the system robustness’s can be greatly improved by increasing the number of qubits constituting the system.展开更多
Thiswork investigates an oblique stagnation point flowof hybrid nanofluid over a rigid surface with power lawfluidas lubricated layers. Copper (Cu) and Silver (Ag) solid particles are used as hybrid particles acting i...Thiswork investigates an oblique stagnation point flowof hybrid nanofluid over a rigid surface with power lawfluidas lubricated layers. Copper (Cu) and Silver (Ag) solid particles are used as hybrid particles acting in water H2O asa base fluid. The mathematical formulation of flow configuration is presented in terms of differential systemthat isnonlinear in nature. The thermal aspects of the flow field are also investigated by assuming the surface is a heatedsurface with a constant temperature T. Numerical solutions to the governing mathematical model are calculatedby the RK45 algorithm. The results based on the numerical solution against various flow and thermal controllingparameters are presented in terms of line graphs. The specific results depict that the heat flux increases over thelubricated-indexed parameter.展开更多
Landscape urbanization broadly affects ecosystems in coastal watersheds, but, until now, the influence of nonpoint source urban inputs on dissolved organic matter (DOM) amount, composition, and source is poorly unders...Landscape urbanization broadly affects ecosystems in coastal watersheds, but, until now, the influence of nonpoint source urban inputs on dissolved organic matter (DOM) amount, composition, and source is poorly understood. To understand how DOM composition varied with urbanization, fluorescence excitation-emission matrices (EEMs) were determined for urban and non-urban waters from upstream to downstream sites along three adjacent coastal watersheds that flow into the Mediterranean Sea. Two humic DOM fluorescent components (humic-like and fulvic-like peaks) and two proteinic components (tyrosine-like and tryptophane-like peaks) were identified by EEM fluorescence. The results indicated that urbanization had an important influence on DOM concentration and composition, with urban waters having a high degree of DOM variation due to different land uses surrounding each body of water. Urban waters show a higher DOM fluorescence index (FI), the highest fluorescence intensity of protein-like manifested also by BIX values, and a lower value of the humification index (HIX) than non-urban waters which were dominated by allochthonous inputs. In addition, the EEM was compared in dry and wet season where higher DOM amounts and FI appeared in summer due to autochthonous production coming from algae growth compared to allochthonous input from rainfall dominated in wet season. The concentration of DOC increased from upstream to downstream for the three rivers, especially Beirut River. The increase in DOC values was observed in both dry and wet seasons by 39 and 19 times respectively compared to upstream (0.93 - 0.91 mgC/L).展开更多
In order to get to the desired target inside the body,it is essential to investigate the needle-tissue coupling process and calculate the tissue deformation.A cantilever beam model is presented to predicting the defle...In order to get to the desired target inside the body,it is essential to investigate the needle-tissue coupling process and calculate the tissue deformation.A cantilever beam model is presented to predicting the deflection and bending angle of flexible needle by analyzing the distribution of the force on needle shaft during the procedure of needle insertion into soft tissue.Furthermore,a finite element(FE)coupling model is proposed to simulate the needle-tissue interactive process.The plane and spatial models are created to relate the needle and tissue nodes.Combined with the cantilever beam model and the finite element needle-tissue coupling model,the simulation of needle-tissue interaction was carried out by the ABAQUS software.The comparing experiments are designed to understand the needle-tissue interactions,by which the same points in the experiments and simulation are compared and analyzed.The results show that the displacements in x and z directions in the simulation can accord with the experiments,and the deformation inside the tissue mainly occurs in the axial direction.The study is beneficial to the robot-assisted and virtual needle insertion procedure,and to help the physicians to predict the inside tissue deformation during the treatments.展开更多
We analyzed the effect of colored noise on the negativity dynamics of a hybrid system consisting of a qubit-qutrit and not interacting,prepared from the start in an entangled one-parameter state and acting with noise ...We analyzed the effect of colored noise on the negativity dynamics of a hybrid system consisting of a qubit-qutrit and not interacting,prepared from the start in an entangled one-parameter state and acting with noise in local and non-local environments.In this pink and brown noise we investigated two different situations:in the first situation,the noise is produced by a bistable oscillator with an unknown exchange rate;however,in the second situation,the noise is generated by a set of bistable oscillators.We found that entanglement decreases with time to zero,and undergoes the phenomenon of sudden death and rebirth.The pink noise is more prone to entanglement than the brown noise and the non-local environment is more prone to entanglement than the local one.When the number of fluctuators is increased,entanglement decays faster and finally,for certain parameters of the initial state,the subsystems are not affected by the noise.展开更多
Cadmium (Cd), one of the most toxic heavy metals added to soil after phosphate fertilizer treatment, was investigated. The effects of this metal on morphological and physiological changes of Lactuca sativa were studie...Cadmium (Cd), one of the most toxic heavy metals added to soil after phosphate fertilizer treatment, was investigated. The effects of this metal on morphological and physiological changes of Lactuca sativa were studied in addition to its partitioning in different parts of the crop. In parallel, Lactuca sativa was allowed to grow under hydroponic conditions with modifications of the Hoagland nutrient solution. This solution was submitted to five Cd concentrations, 0, 0.093, 0.186, 0.279 and 0.372 mg Cd/L and three P concentrations, 0, 299 and 1420 mg P/L. The study showed a positive effect of phosphorus on root elongation, surface area while cadmium inhibited plant growth and sometimes the death of the plants. Cadmium was found to be accumulated in roots while zinc was preferably accumulated in the leaves and stems. The increase of performance of Lactuca sativa under hydroponic condition and Hoagland contaminated solution with cadmium was found to be better than the ones grown in Cd amended soil with or without phosphorus.展开更多
Recent devastating earthquakes in some countries, such as Pakistan, Turkey, Algeria and China, call to the mind the high risk exposure of Lebanon which is located over an active seismic zone. Many experts shared the v...Recent devastating earthquakes in some countries, such as Pakistan, Turkey, Algeria and China, call to the mind the high risk exposure of Lebanon which is located over an active seismic zone. Many experts shared the view that major seismic event may occur in Lebanon in the future. Moreover, many earthquakes, of low magnitudes between three and four, have been registered in Lebanon during 2008. These events have increased the anxiety of Lebanese people because of the poor quality of the constructions and their behavior under moderate or severe earthquake events. The efficient way to minimize seismic effects, material and human losses, is the prevention. The system piles-foundation is an appropriate way and widely used to ensure the stability of constructions when subjected to seismic excitation. It seems necessary to study the interaction of pile-foundation-pile-cap-structure in the case of non linear soil behavior and the interface pile-soil. The study will be also conducted by using measures recorded during real earthquakes for example in Turkey (Kocaeli, 1999). In this paper, we present a numerical modeling of the interaction of using FLAC3D software. According to soil behavior and pile inclination, parametric studies are also performed. The analysis of the results could give the better piles group configuration in order to minimize the seismic effect on the structures.展开更多
The East Asian Very Long Baseline Interferometry(VLBI) Network(EAVN) is a rapidly evolving international VLBI array that is currently promoted under joint efforts among China,Japan and Korea.EAVN aims at forming a joi...The East Asian Very Long Baseline Interferometry(VLBI) Network(EAVN) is a rapidly evolving international VLBI array that is currently promoted under joint efforts among China,Japan and Korea.EAVN aims at forming a joint VLBI Network by combining a large number of radio telescopes distributed over East Asian regions.After the combination of the Korean VLBI Network(KVN) and the VLBI Exploration of Radio Astrometry(VERA) into Ka VA,further expansion with the joint array in East Asia is actively promoted.Here we report the first imaging results(at 22 and 43 GHz) of bright radio sources obtained with Ka VA connected to Tianma 65-m and Nanshan 26-m Radio Telescopes in China.To test the EAVN imaging performance for different sources,we observed four active galactic nuclei(AGN) having different brightness and morphology.As a result,we confirmed that the Tianma 65-m Radio Telescope(TMRT) significantly enhances the overall array sensitivity,a factor of 4 improvement in baseline sensitivity and 2 in image dynamic range compared to the case of Ka VA only.The addition of the Nanshan 26-m Radio Telescope(NSRT) further doubled the east-west angular resolution.With the resulting high-dynamic-range,high-resolution images with EAVN(Ka VA+TMRT+NSRT),various fine-scale structures in our targets,such as the counter-jet in M87,a kink-like morphology of the 3 C 273 jet and the weak emission in other sources are successfully detected.This demonstrates the powerful capability of EAVN to study AGN jets and to achieve other science goals in general.Ongoing expansion of EAVN will further enhance the angular resolution,detection sensitivity and frequency coverage of the network.展开更多
Open source software (OSS) has become an indispensable part of society, not only for personal use but also for corporate use. Projects developed and operated by OSS are called open source projects, and the number of s...Open source software (OSS) has become an indispensable part of society, not only for personal use but also for corporate use. Projects developed and operated by OSS are called open source projects, and the number of such projects is increasing. On the other hand, because anyone can participate in an open source project, the progress of the project is uncertain due to differences in project members’ skills, development environments, and time zones of activity. Therefore, many users and companies need to understand the development and operation status of open source project. Then, the developers carefully make decisions on upgrading or installing new OSS. In this paper, we focus on the maintenance effort estimation for open source projects considering uncertainty. Also, we evaluate the project quantitatively using Earned Value Management (EVM). Moreover, we examine the appropriateness of the model for predicting the maintenance effort expeditures. Furthermore, we discuss the appropriateness of this EVM method.展开更多
Ceramic porous MgTiO3 materials have been prepared by classical solid-state route. The sintered pellets of MgTiO3 with different LiF contents were characterized for humidity-sensing application. The sintered disks of ...Ceramic porous MgTiO3 materials have been prepared by classical solid-state route. The sintered pellets of MgTiO3 with different LiF contents were characterized for humidity-sensing application. The sintered disks of these mixtures were subjected to capacitance measurements at 20℃as function of the relative humidity from which revealed that the Mixture MgTiO3 + 2% LiF (w/w) has the better characteristics. The disks were subjected to DC resistance measurements as a function of relative humidity in the range 15% - 95% RH. The selectivity of this material was discussed and compared to commercial sensor results. The response and recovery characteristics were assessed.展开更多
Termite queens and kings live longer than nonreproductive workers.Several molecular mechanisms contributing to their long lifespan have been investigated;however,the underlying biochemical explanation remains unclear....Termite queens and kings live longer than nonreproductive workers.Several molecular mechanisms contributing to their long lifespan have been investigated;however,the underlying biochemical explanation remains unclear.Coenzyme Q(CoQ),a component of the mitochondrial electron transport chain,plays an essential role in the lipophilic antioxidant defense system.Its beneficial effects on health and longevity have been well studied in several organisms.Herein,we demonstrated that long-lived termite queens have significantly higher levels of the lipophilic antioxidant CoQ_(10) than workers.Liquid chromatography analysis revealed that the levels of the reduced form of CoQ_(10) were 4 fold higher in the queen's body than in the worker's body.In addition,queens showed 7 fold higher levels of vitamin E,which plays a role in antilipid peroxidation along with CoQ,than workers.Furthermore,the oral administration of CoQ_(10) to termites increased the CoQ_(10) redox state in the body and their survival rate under oxidative stress.These findings suggest that CoQ_(10) acts as an efficient lipophilic antioxidant along with vitamin E in long-lived termite queens.This study provides essential biochemical and evolutionary insights into the relationship between CoQ_(10) concentrations and termite lifespan extension.展开更多
Rivers are progressively being exposed to increased anthropogenic pollution stresses that are undermining their designated uses and affecting sensitive coastal areas. In this study, three adjacent eastern Mediterranea...Rivers are progressively being exposed to increased anthropogenic pollution stresses that are undermining their designated uses and affecting sensitive coastal areas. In this study, three adjacent eastern Mediterranean coastal rivers, Ibrahim, Kaleb and Beirut, were evaluated. Water quality samples were collected in dry and wet seasons from different sampling sites along the river from the source to the outlet which represent a gradient of increased urbanization. The spatiotemporal variability of the physio-chemical properties, heavy metals (Zn, Pb, Cu, Cr, and Cd) and organic matter (DOC) were statistically analyzed to better understand the contribution of point and nonpoint pollution sources. The three rivers (Beirut, Kaleb and Ibrahim) show a similar behavior in calcium and carbonate alkalinity due to the carbonate mineral weathering effect, so they are of calcium bicarbonate type due to their calcareous geological nature. The speciation of anions was affected by temporal variation. Moreover, it is obvious that the Beirut River has a different behavioral characteristic where the water is a sulfate type water with a preferable metal-OM complexation mainly with lead, zinc and copper, whereas Kaleb and Ibrahim are considered to be of a nitrate phosphate type with a preferable metal inorganic complexation, especially copper, that has a consistent behavior in both types of waters. This difference is attributed to the urbanization effect highly impacting the Beirut River.展开更多
The concept of sharing of personal health data over cloud storage in a healthcare-cyber physical system has become popular in recent times as it improves access quality.The privacy of health data can only be preserved...The concept of sharing of personal health data over cloud storage in a healthcare-cyber physical system has become popular in recent times as it improves access quality.The privacy of health data can only be preserved by keeping it in an encrypted form,but it affects usability and flexibility in terms of effective search.Attribute-based searchable encryption(ABSE)has proven its worth by providing fine-grained searching capabilities in the shared cloud storage.However,it is not practical to apply this scheme to the devices with limited resources and storage capacity because a typical ABSE involves serious computations.In a healthcare cloud-based cyber-physical system(CCPS),the data is often collected by resource-constraint devices;therefore,here also,we cannot directly apply ABSE schemes.In the proposed work,the inherent computational cost of the ABSE scheme is managed by executing the computationally intensive tasks of a typical ABSE scheme on the blockchain network.Thus,it makes the proposed scheme suitable for online storage and retrieval of personal health data in a typical CCPS.With the assistance of blockchain technology,the proposed scheme offers two main benefits.First,it is free from a trusted authority,which makes it genuinely decentralized and free from a single point of failure.Second,it is computationally efficient because the computational load is now distributed among the consensus nodes in the blockchain network.Specifically,the task of initializing the system,which is considered the most computationally intensive,and the task of partial search token generation,which is considered as the most frequent operation,is now the responsibility of the consensus nodes.This eliminates the need of the trusted authority and reduces the burden of data users,respectively.Further,in comparison to existing decentralized fine-grained searchable encryption schemes,the proposed scheme has achieved a significant reduction in storage and computational cost for the secret key associated with users.It has been verified both theoretically and practically in the performance analysis section.展开更多
文摘This paper reviews the applications of the multi degree-of-freedom(MDOF)equivalent linear system in seismic analysis and design of planar steel and reinforced concrete framed structures.An equivalent MDOF linear structure,analogous to the original MDOF nonlinear structure,is constructed,which has the same mass and elastic stiffness as the original structure and modal damping ratios that account for the effects of geometrical and material nonlinearities.The equivalence implies a balance between the viscous damping work of the equivalent linear structure and that of the nonlinearities in the original nonlinear structure.This work balance is established with the aid of a transfer function in the frequency domain.Thus,equivalent modal damping ratios can be explicitly determined in terms of the period and deformation levels of the structure as well as the soil types.Use of these equivalent modal damping ratios can help address a variety of seismic analysis and design problems associated with planar steel and reinforced concrete framed structures in a rational and accurate manner.These include force-based seismic design with the aid of acceleration response spectra characterized by high amounts of damping,improved direct displacement-based seismic design and the development of advanced seismic intensity measures.The equivalent modal damping ratios are also utilized in the context of linear modal analysis for the definition and construction of the MDOF response spectrum.Furthermore,the equivalent modal damping ratios are employed in a seismic retrofit method for steel-framed structures with viscous dampers.Finally,it is demonstrated that modal behavior(or strength reduction)factors can be easily constructed based on these modal damping ratios for a more rational and accurate force-based seismic design,including the determination of inelastic displacement profiles.
文摘Background and Objective: HIV, hepatitis B virus (HBV) and hepatitis C virus (HCV) are very widespread in the world, however, less than 20% of the people affected are diagnosed and treated. This study aimed to determine the prevalence of HIV, HCV and HBV co-infections in pregnant women at Bangui Community University Hospital and the cost of screening. Methods: A cross-sectional study involving consenting pregnant women who came for antenatal care was performed. HIV, HCV antibodies and HBV antigens were detected using Exacto Triplex<sup>?</sup> HIV/HCV/HBsAg rapid test, cross-validated by ELISA tests. Sociodemographic and professional data, the modes of transmission and prevention of HIV and both hepatitis viruses were collected in a standard sheet and analyzed using the Epi-Info software version 7. Results: Pregnant women aged 15 to 24 were the most affected (45.3%);high school girls (46.0%), and pregnant women living in cohabitation (65.3%) were the most represented. Twenty-five (16.7%) worked in the formal sector, 12.7% were unemployed housewives and the remainder in the informal sector. The prevalence of HIV, HBV, and HCV viruses was 11.8%, 21.9% and 22.2%, respectively. The prevalence of co-infections was 8.6% for HIV-HBV, 10.2% for HIV-HCV, 14.7% for HBV-HCV and 6.5% for HIV-HBV-HCV. All positive results and 10% of negative results by the rapid test were confirmed by ELISA tests. The serology of the three viruses costs 39,000 FCFA (60 Euros) by ELISA compared to 10,000 FCFA (15.00 Euros) with Exacto Triplex<sup>?</sup> HIV/HCV/AgHBs (BioSynex, Strasbourg, France). Conclusion: The low level of education and awareness of hepatitis are barriers to development and indicate the importance of improving the literacy rate of women in the Central African Republic (CAR). Likewise, the high prevalence of the three viruses shows the need for the urgent establishment of a national program to combat viral hepatitis in the CAR.
基金support he received through General Research Project under the grant number (R.G.P.2/138/42)。
文摘A numerical analysis of the log-law behavior for the turbulent boundary layer of a wall-bounded flow is performed over a flat plate immersed in three nanofluids(Zn O-water,SiO_(2)-water,TiO_(2)-water).Numerical simulations using CFD code are employed to investigate the boundary layer and the hydrodynamic flow.To validate the current numerical model,measurement points from published works were used,and the compared results were in good compliance.Simulations were carried out for the velocity series of 0.04,0.4 and 4 m/s and nanoparticle concentrations0.1% and 5%.The influence of nanoparticles’ concentration on velocity,temperature profiles,wall shear stress,and turbulent intensity was investigated.The obtained results showed that the viscous sub-layer,the buffer layer,and the loglaw layer along the potential-flow layer could be analyzed based on their curving quality in the regions which have just a single wall distance.It was seen that the viscous sub-layer is the biggest area in comparison with other areas.Alternatively,the section where the temperature changes considerably correspond to the thermal boundary layer’s thickness goes a downward trend when the velocity decreases.The thermal boundary layer gets deep away from the leading edge.However,a rise in the volume fraction of nanoparticles indicated a minor impact on the shear stress developed in the wall.In all cases,the thickness of the boundary layer undergoes a downward trend as the velocity increases,whereas increasing the nanoparticle concentrations would enhance the thickness.More precisely,the log layer is closed with log law,and it is minimal between Y^(+)=50 and Y^(+)=95.The temperature for nanoparticle concentration φ=5%is higher than that for φ=0.1%,in boundary layers,for all studied nanofluids.However,it is established that the behavior is inverted from the value of Y^(+)=1 and the temperature for φ =0.1% is more important than the case of φ =5%.For turbulence intensity peak,this peak exists at Y^(+)=100 for v=4 m/s,Y^(+)=10 for v=0.4 m/s and Y^(+)=8 for v=0.04 m/s.
基金supported by the Grants-in-Aid for Scientific Research(C)under Grant No.17560295-3620。
文摘TheⅡ-Ⅵbased magnetic semiconductors with a direct and wide optical bandgap are expected to show high potential for optical applications utilizing short wavelength laser diodes(LDs),such as 532-nm green and475-nm blue LDs.We have confirmed that the Faraday rotationθ_F in the ZnMnTe and ZnMnSe films deposited on quartz glass(QG)and sapphire(SA)substrates by using molecular beam epitaxy(MBE)is large near the absorption edge.This paper reports the magneto-optical properties of ZnMnTe and ZnMnSe films synthesized on the QG and SA substrates,and shows the result of a direct Faraday rotation observation successfully made for the ZnMnTe films under 1.28-kHz alternating magnetic fields.The optical absorption characteristics of the ZnMnTe films grown on the SA substrates by MBE are discussed by comparing them with the optical absorption properties and photoluminescence spectra of theⅡ-ⅥZnTe parent single crystals.
文摘Flat foot in children is a common deformation, which appears during the first years of life. It requires a rigorous evaluation to rule out congenital or neurological abnormality. It is characterized by a decrease of the plantar concavity indeed collapse of the foot, often associated with other morphostatic deformations. The aim of this study is to find a correlation between the essential flat foot in children and lower limb disorders torsional. It is a cross-sectional descriptive study, recruiting 110 children (220 feet) aged between 3 and 6 years old. Each child was given an assessment of the morphology of the foot (Contact Index II…) and lower limb rotational profile (intoeing and femoral antétorsion and tibal torsion). Among 110 children, 21 (19.1%) have bilateral flat feet and 7 (6.4%) have unilateral flat feet, associated with an average value of Contact Index II equal to 0.921;the minimum value is 0.880 and the maximum value is 1.17. All children with flat feet have excessive femoral antétorsion;45 (92%) are associated with a hip intoeing and 38 (80%) present an insufficient external tibial torsion. The analysis of multiple regression shows a significantly elevated correlation among the flat foot and excessive internal rotation of the hip (F = 70.36, r = 0.77, P < 0.001), excessive femoral antetorsion (F = 54.78, r = 0.73, P < 0.001) and insufficient external tibial torsion (F = 7.79, r = 0.37, P < 0.001).
文摘The quality traits of fresh marketable chicken eggs collected during winter, autumn and summer periods from different local markets in Lebanon were evaluated in order to understand the reproductive fitness of the chicken and the correlation between collection dates. A total of 2000 brown and white eggs were analyzed and compared for their external quality parameters such as egg weight, length, width, size, shell thickness, specific gravity and for their internal quality traits such as Haugh unit, yolk diameter, yolk color, and yolk height. Results show that egg weight and size varied markedly and tended to be smaller during summer period. A significant difference was found between white and brown eggs in some quality traits such as egg weight, shell thickness, egg length, and yolk diameter parameters. Egg quality parameters were significantly reduced during summer season where eggs are exposed to high temperature conditions. For grading analysis, 80% of the total eggs were classified as A with a significant difference (p < 0.05) between white and brown egg and during collection dates. Overall, brown eggs graded better than white eggs in external quality cleanliness and shape. Based on our analysis, the results of this study show that Lebanese eggs are of good quality and suggest that proper egg handling and storage conditions should be applied especially at warm environmental conditions to improve egg quality during summer season.
文摘It is believed that mechanical stimuli, such as stretching of the extracellular matrix, are transmitted into cells via focal adhesion complexes and the actin cytoskeleton. Transmission dynamics of strain from the extracellular matrix into intracellular organelles is crucial to clarify the mechanosensing mechanisms of cells. In this study, we observed deformation behavior of actin stress fibers under uniaxial stretch using an originally developed cell-stretching microelectromechanical system (MEMS) device. It was difficult to conduct in situ observation of cells under stretch using conventional cell stretching devices, because motion artifacts such as rigid displacement during stretch application were not negligible. Our novel cell-stretching MEMS device suppressed rigid displacement while stretching, and we succeeded in obtaining time-lapse images of stretched cells. Uniaxial strain with a 10% magnitude and strain rate of 0.5%/sec was applied to cells. Deformation behaviors of the cells and actin stress fibers were recorded using a confocal laser scanning microscope. In time-lapse images of stretched cells, strains along each stress fiber were measured manually. As a result, in cells with a relatively homogeneous stress fiber structure oriented in one direction, distribution of the axial strain on stress fibers generally corresponded to deformation of the stretching sheet on which the cells had adhered. However, in cells with a heterogeneous stress fiber structure oriented in several directions, we found that the strain distribution along stress fibers was not homogeneous. In regions around the cell nucleus, there was a more complicated strain distribution compared with other regions. Our results suggest the cell nucleus with a stiff mechanical resistance yields such a complicated strain distribution in stress fibers.
文摘We investigate the dynamics of entanglement through negativity and witness operators in a system of four noninteracting qubits driven by a classical phase noisy laser characterized by a classical random external field(CREF).The qubits are initially prepared in the GHZ-type and W-type states and interact with the CREF in two different qubit-field configurations,namely,common environment and independent environments in which the cases of equal and different field phase probabilities are distinguished.We find that entanglement exhibits different decaying behavior,depending on the input states of the qubits,the qubit-field coupling configuration,and field phase probabilities.On the one hand,we demonstrate that the coupling of the qubits in a common environment is an alternative and more efficient strategy to completely shield the system from the detrimental impacts of the decoherence process induced by a CREF,independent of the input state and the field phase probabilities considered.Also,we show that GHZ-type states have strong dynamics under CREF as compared to W-type states.On the other hand,we demonstrate that in the model investigated the system robustness’s can be greatly improved by increasing the number of qubits constituting the system.
文摘Thiswork investigates an oblique stagnation point flowof hybrid nanofluid over a rigid surface with power lawfluidas lubricated layers. Copper (Cu) and Silver (Ag) solid particles are used as hybrid particles acting in water H2O asa base fluid. The mathematical formulation of flow configuration is presented in terms of differential systemthat isnonlinear in nature. The thermal aspects of the flow field are also investigated by assuming the surface is a heatedsurface with a constant temperature T. Numerical solutions to the governing mathematical model are calculatedby the RK45 algorithm. The results based on the numerical solution against various flow and thermal controllingparameters are presented in terms of line graphs. The specific results depict that the heat flux increases over thelubricated-indexed parameter.
文摘Landscape urbanization broadly affects ecosystems in coastal watersheds, but, until now, the influence of nonpoint source urban inputs on dissolved organic matter (DOM) amount, composition, and source is poorly understood. To understand how DOM composition varied with urbanization, fluorescence excitation-emission matrices (EEMs) were determined for urban and non-urban waters from upstream to downstream sites along three adjacent coastal watersheds that flow into the Mediterranean Sea. Two humic DOM fluorescent components (humic-like and fulvic-like peaks) and two proteinic components (tyrosine-like and tryptophane-like peaks) were identified by EEM fluorescence. The results indicated that urbanization had an important influence on DOM concentration and composition, with urban waters having a high degree of DOM variation due to different land uses surrounding each body of water. Urban waters show a higher DOM fluorescence index (FI), the highest fluorescence intensity of protein-like manifested also by BIX values, and a lower value of the humification index (HIX) than non-urban waters which were dominated by allochthonous inputs. In addition, the EEM was compared in dry and wet season where higher DOM amounts and FI appeared in summer due to autochthonous production coming from algae growth compared to allochthonous input from rainfall dominated in wet season. The concentration of DOC increased from upstream to downstream for the three rivers, especially Beirut River. The increase in DOC values was observed in both dry and wet seasons by 39 and 19 times respectively compared to upstream (0.93 - 0.91 mgC/L).
基金This research work is sponsored by the National Natural Science Foundation of China(No.51665049).
文摘In order to get to the desired target inside the body,it is essential to investigate the needle-tissue coupling process and calculate the tissue deformation.A cantilever beam model is presented to predicting the deflection and bending angle of flexible needle by analyzing the distribution of the force on needle shaft during the procedure of needle insertion into soft tissue.Furthermore,a finite element(FE)coupling model is proposed to simulate the needle-tissue interactive process.The plane and spatial models are created to relate the needle and tissue nodes.Combined with the cantilever beam model and the finite element needle-tissue coupling model,the simulation of needle-tissue interaction was carried out by the ABAQUS software.The comparing experiments are designed to understand the needle-tissue interactions,by which the same points in the experiments and simulation are compared and analyzed.The results show that the displacements in x and z directions in the simulation can accord with the experiments,and the deformation inside the tissue mainly occurs in the axial direction.The study is beneficial to the robot-assisted and virtual needle insertion procedure,and to help the physicians to predict the inside tissue deformation during the treatments.
文摘We analyzed the effect of colored noise on the negativity dynamics of a hybrid system consisting of a qubit-qutrit and not interacting,prepared from the start in an entangled one-parameter state and acting with noise in local and non-local environments.In this pink and brown noise we investigated two different situations:in the first situation,the noise is produced by a bistable oscillator with an unknown exchange rate;however,in the second situation,the noise is generated by a set of bistable oscillators.We found that entanglement decreases with time to zero,and undergoes the phenomenon of sudden death and rebirth.The pink noise is more prone to entanglement than the brown noise and the non-local environment is more prone to entanglement than the local one.When the number of fluctuators is increased,entanglement decays faster and finally,for certain parameters of the initial state,the subsystems are not affected by the noise.
文摘Cadmium (Cd), one of the most toxic heavy metals added to soil after phosphate fertilizer treatment, was investigated. The effects of this metal on morphological and physiological changes of Lactuca sativa were studied in addition to its partitioning in different parts of the crop. In parallel, Lactuca sativa was allowed to grow under hydroponic conditions with modifications of the Hoagland nutrient solution. This solution was submitted to five Cd concentrations, 0, 0.093, 0.186, 0.279 and 0.372 mg Cd/L and three P concentrations, 0, 299 and 1420 mg P/L. The study showed a positive effect of phosphorus on root elongation, surface area while cadmium inhibited plant growth and sometimes the death of the plants. Cadmium was found to be accumulated in roots while zinc was preferably accumulated in the leaves and stems. The increase of performance of Lactuca sativa under hydroponic condition and Hoagland contaminated solution with cadmium was found to be better than the ones grown in Cd amended soil with or without phosphorus.
文摘Recent devastating earthquakes in some countries, such as Pakistan, Turkey, Algeria and China, call to the mind the high risk exposure of Lebanon which is located over an active seismic zone. Many experts shared the view that major seismic event may occur in Lebanon in the future. Moreover, many earthquakes, of low magnitudes between three and four, have been registered in Lebanon during 2008. These events have increased the anxiety of Lebanese people because of the poor quality of the constructions and their behavior under moderate or severe earthquake events. The efficient way to minimize seismic effects, material and human losses, is the prevention. The system piles-foundation is an appropriate way and widely used to ensure the stability of constructions when subjected to seismic excitation. It seems necessary to study the interaction of pile-foundation-pile-cap-structure in the case of non linear soil behavior and the interface pile-soil. The study will be also conducted by using measures recorded during real earthquakes for example in Turkey (Kocaeli, 1999). In this paper, we present a numerical modeling of the interaction of using FLAC3D software. According to soil behavior and pile inclination, parametric studies are also performed. The analysis of the results could give the better piles group configuration in order to minimize the seismic effect on the structures.
基金supported by The Graduate University for Advanced Studies (SOKENDAI)supported by the Japanese Government (MEXT) Scholarship+18 种基金supported by JSPS KAKENHI Grant Numbers JP18K03656 (M.K.),JP18H03721 (K.N.,K.H.and M.K.),JP19H01943 (K.H.,F.T.and Y.H.) and JP18KK0090 (K.H.and F.T.)supported by the Mitsubishi Foundation (grant number 201911019)supported by an EACOA Fellowship awarded by the East Asia Core Observatories Association,which consists of the Academia Sinica Institute of Astronomy and Astrophysics,the National Astronomical Observatory of Japan,the Center for Astronomical Mega-Science,the Chinese Academy of Sciencesthe Korea Astronomy and Space Science Institutethe financial support from the National Research Foundation (NRF) of Korea via Global Ph.D.Fellowship Grant 2014H1A2A1018695 and 2015H1A2A1033752,respectivelysupport from the NRF via Grant 2019R1F1A1059721supported by the Major Program of the National Natural Science Foundation of China (NSFC,Grant Nos.11590780 and 11590784)the Knowledge Innovation Program of the Chinese Academy of Sciences (Grant No.KJCX1-YW-18)the Scientific Program of Shanghai Municipality (08DZ1160100)Key Laboratory for Radio Astronomy,CASsupport from NSFC (Grant No.11803071)supported by the National Key R&D Program of China (Grant No.2018YFA0404602)the CAS ‘Light of West China’ Program (Grant No.2018-XBQNXZ-B021)the NSFC (Grant Nos.U2031212 and 61931002)the Youth Innovation Promotion Association of the CAS (Grant No.2017084)support from Fundamental Research Grant Scheme (FRGS) FRGS/1/2019/STG02/UM/02/6supported by the Max Planck Partner Group of the MPG and the CASthe support by the Key Program of the NSFC (Grant No.11933007)the Research Program of Fundamental and Frontier Sciences,CAS (Grant No.ZDBS-LY-SLH011)。
文摘The East Asian Very Long Baseline Interferometry(VLBI) Network(EAVN) is a rapidly evolving international VLBI array that is currently promoted under joint efforts among China,Japan and Korea.EAVN aims at forming a joint VLBI Network by combining a large number of radio telescopes distributed over East Asian regions.After the combination of the Korean VLBI Network(KVN) and the VLBI Exploration of Radio Astrometry(VERA) into Ka VA,further expansion with the joint array in East Asia is actively promoted.Here we report the first imaging results(at 22 and 43 GHz) of bright radio sources obtained with Ka VA connected to Tianma 65-m and Nanshan 26-m Radio Telescopes in China.To test the EAVN imaging performance for different sources,we observed four active galactic nuclei(AGN) having different brightness and morphology.As a result,we confirmed that the Tianma 65-m Radio Telescope(TMRT) significantly enhances the overall array sensitivity,a factor of 4 improvement in baseline sensitivity and 2 in image dynamic range compared to the case of Ka VA only.The addition of the Nanshan 26-m Radio Telescope(NSRT) further doubled the east-west angular resolution.With the resulting high-dynamic-range,high-resolution images with EAVN(Ka VA+TMRT+NSRT),various fine-scale structures in our targets,such as the counter-jet in M87,a kink-like morphology of the 3 C 273 jet and the weak emission in other sources are successfully detected.This demonstrates the powerful capability of EAVN to study AGN jets and to achieve other science goals in general.Ongoing expansion of EAVN will further enhance the angular resolution,detection sensitivity and frequency coverage of the network.
文摘Open source software (OSS) has become an indispensable part of society, not only for personal use but also for corporate use. Projects developed and operated by OSS are called open source projects, and the number of such projects is increasing. On the other hand, because anyone can participate in an open source project, the progress of the project is uncertain due to differences in project members’ skills, development environments, and time zones of activity. Therefore, many users and companies need to understand the development and operation status of open source project. Then, the developers carefully make decisions on upgrading or installing new OSS. In this paper, we focus on the maintenance effort estimation for open source projects considering uncertainty. Also, we evaluate the project quantitatively using Earned Value Management (EVM). Moreover, we examine the appropriateness of the model for predicting the maintenance effort expeditures. Furthermore, we discuss the appropriateness of this EVM method.
文摘Ceramic porous MgTiO3 materials have been prepared by classical solid-state route. The sintered pellets of MgTiO3 with different LiF contents were characterized for humidity-sensing application. The sintered disks of these mixtures were subjected to capacitance measurements at 20℃as function of the relative humidity from which revealed that the Mixture MgTiO3 + 2% LiF (w/w) has the better characteristics. The disks were subjected to DC resistance measurements as a function of relative humidity in the range 15% - 95% RH. The selectivity of this material was discussed and compared to commercial sensor results. The response and recovery characteristics were assessed.
基金This work was supported by the Japan Society for the Promotion of Science(JSPS)KAKENHI grants No.JP20K06074 to Y.I.and JP22K14830 to E.T.We sincerely thank Yuuki Kiya,Tomonori Masui,and Daigo Ogawa at Tokyo University of Technology for their technical support as well as Kenji Matsuura and the members of the Laboratory of Insect Ecology at Kyoto University for valuable suggestions and comments.We also thank our laboratory colleagues at Yamaguchi University and Tokyo University of Technology for their cooperation during this study.
文摘Termite queens and kings live longer than nonreproductive workers.Several molecular mechanisms contributing to their long lifespan have been investigated;however,the underlying biochemical explanation remains unclear.Coenzyme Q(CoQ),a component of the mitochondrial electron transport chain,plays an essential role in the lipophilic antioxidant defense system.Its beneficial effects on health and longevity have been well studied in several organisms.Herein,we demonstrated that long-lived termite queens have significantly higher levels of the lipophilic antioxidant CoQ_(10) than workers.Liquid chromatography analysis revealed that the levels of the reduced form of CoQ_(10) were 4 fold higher in the queen's body than in the worker's body.In addition,queens showed 7 fold higher levels of vitamin E,which plays a role in antilipid peroxidation along with CoQ,than workers.Furthermore,the oral administration of CoQ_(10) to termites increased the CoQ_(10) redox state in the body and their survival rate under oxidative stress.These findings suggest that CoQ_(10) acts as an efficient lipophilic antioxidant along with vitamin E in long-lived termite queens.This study provides essential biochemical and evolutionary insights into the relationship between CoQ_(10) concentrations and termite lifespan extension.
文摘Rivers are progressively being exposed to increased anthropogenic pollution stresses that are undermining their designated uses and affecting sensitive coastal areas. In this study, three adjacent eastern Mediterranean coastal rivers, Ibrahim, Kaleb and Beirut, were evaluated. Water quality samples were collected in dry and wet seasons from different sampling sites along the river from the source to the outlet which represent a gradient of increased urbanization. The spatiotemporal variability of the physio-chemical properties, heavy metals (Zn, Pb, Cu, Cr, and Cd) and organic matter (DOC) were statistically analyzed to better understand the contribution of point and nonpoint pollution sources. The three rivers (Beirut, Kaleb and Ibrahim) show a similar behavior in calcium and carbonate alkalinity due to the carbonate mineral weathering effect, so they are of calcium bicarbonate type due to their calcareous geological nature. The speciation of anions was affected by temporal variation. Moreover, it is obvious that the Beirut River has a different behavioral characteristic where the water is a sulfate type water with a preferable metal-OM complexation mainly with lead, zinc and copper, whereas Kaleb and Ibrahim are considered to be of a nitrate phosphate type with a preferable metal inorganic complexation, especially copper, that has a consistent behavior in both types of waters. This difference is attributed to the urbanization effect highly impacting the Beirut River.
文摘The concept of sharing of personal health data over cloud storage in a healthcare-cyber physical system has become popular in recent times as it improves access quality.The privacy of health data can only be preserved by keeping it in an encrypted form,but it affects usability and flexibility in terms of effective search.Attribute-based searchable encryption(ABSE)has proven its worth by providing fine-grained searching capabilities in the shared cloud storage.However,it is not practical to apply this scheme to the devices with limited resources and storage capacity because a typical ABSE involves serious computations.In a healthcare cloud-based cyber-physical system(CCPS),the data is often collected by resource-constraint devices;therefore,here also,we cannot directly apply ABSE schemes.In the proposed work,the inherent computational cost of the ABSE scheme is managed by executing the computationally intensive tasks of a typical ABSE scheme on the blockchain network.Thus,it makes the proposed scheme suitable for online storage and retrieval of personal health data in a typical CCPS.With the assistance of blockchain technology,the proposed scheme offers two main benefits.First,it is free from a trusted authority,which makes it genuinely decentralized and free from a single point of failure.Second,it is computationally efficient because the computational load is now distributed among the consensus nodes in the blockchain network.Specifically,the task of initializing the system,which is considered the most computationally intensive,and the task of partial search token generation,which is considered as the most frequent operation,is now the responsibility of the consensus nodes.This eliminates the need of the trusted authority and reduces the burden of data users,respectively.Further,in comparison to existing decentralized fine-grained searchable encryption schemes,the proposed scheme has achieved a significant reduction in storage and computational cost for the secret key associated with users.It has been verified both theoretically and practically in the performance analysis section.