AIM:To establish a recording system with a direct view of the surgeon to supplement video recording under an operating microscope,which lacks information on the movement and position of the surgeon’s hands,and to fac...AIM:To establish a recording system with a direct view of the surgeon to supplement video recording under an operating microscope,which lacks information on the movement and position of the surgeon’s hands,and to facilitate the reproduction of a skilled surgeon’s technique by a surgeon in training.METHODS:A small camera was attached to the operating microscope with a custom adapter.Microscopic surgeon’s view and direct surgeon’s view through this new camera were recorded in the surgical recording system.Both movies were synchronized and analyzed how do surgeons handle the instruments.RESULTS:A small camera attached to the operating microscope allowed the surgeon’s hands motion to be recorded without interfering with the surgeon’s movements.Different surgeons used different methods to manipulate the ultrasound handpiece and the irrigation/aspiration device.Even in the simple paracentesis procedure,different surgeons used different methods.Surgeons-in-training were able to identify and improve their weaknesses by watching synchronized movies of their hand motions and microscopic view.CONCLUSION:Simultaneous recording the surgical field out of the operating microscopic view by a small camera set on the microscope is comprehensive and improves surgeons-in-training understanding and learning surgeries.展开更多
The adoption of new technologies often represents a crucial component of firms' investment decisions. This paper studies a dynamic duopoly model in which two firms compete in adoption of current technology with a fur...The adoption of new technologies often represents a crucial component of firms' investment decisions. This paper studies a dynamic duopoly model in which two firms compete in adoption of current technology with a further new technology anticipated. Here it is assumed that the operating costs are not zero which has more explanatory power of the real world. There exist three kinds of equilibria that may occur in adoption of current technology, which mainly depends on the level of operating costs and the first-move advantage. It shows that the faster technological substitution or innovation encourages the leader to invest earlier while induces the follower to invest later. Furthermore,like the investment costs,with the increase of operating costs the follower tends to invest later while the leader tends to invest earlier ,the investment thresholds are more sensitive to the change of operating costs than that of investment costs.展开更多
A continuous-flow ultrasound-assisted oxidative desulfurization(UAOD)of partially hydro-treated diesel has been investigated using hydrogen peroxide-formic acid as simple and easy to apply oxidation system.The effects...A continuous-flow ultrasound-assisted oxidative desulfurization(UAOD)of partially hydro-treated diesel has been investigated using hydrogen peroxide-formic acid as simple and easy to apply oxidation system.The effects of different operating parameters of oxidation stage including residence time(2–24 min),formic acid to sulfur molar ratio(10–150),and oxidant to sulfur molar ratio(5–35)on the sulfur removal have been studied using response surface methodology(RSM)based on Box–Behnken design.Considering the operating costs of the continuous-flow oxidation stage including chemical and electrical energy consumption,the appropriate values of operating parameters were selected as follows:residence time of 16 min,the formic acid to sulfur molar ratio of 54.47,and the oxidant to sulfur molar ratio of 8.24.In these conditions,the sulfur removal and the volume ratio of the hydrocarbon phase to the aqueous phase were 86.90%and 4.34,respectively.By drastic reduction in the chemical consumption in the oxidation stage,the volume ratio of the hydrocarbon phase to the aqueous phase was increased up to 10.Therefore,the formic acid to sulfur molar ratio and the oxidant to sulfur molar ratio were obtained 23.64 and 3.58,respectively,which lead to sulfur removal of 84.38%with considerable improvements on the operating cost of oxidation stage in comparison with the previous works.展开更多
Metal-halide perovskites are revolutionizing the world of X-ray detectors,due to the development of sensitive,fast,and cost-effective devices.Self-powered operation,ensuring portability and low power consumption,has a...Metal-halide perovskites are revolutionizing the world of X-ray detectors,due to the development of sensitive,fast,and cost-effective devices.Self-powered operation,ensuring portability and low power consumption,has also been recently demonstrated in both bulk materials and thin films.However,the signal stability and repeatability under continuous X-ray exposure has only been tested up to a few hours,often reporting degradation of the detection performance.Here it is shown that self-powered direct X-ray detectors,fabricated starting from a FAPbBr_(3)submicrometer-thick film deposition onto a mesoporous TiO_(2)scaffold,can withstand a 26-day uninterrupted X-ray exposure with negligible signal loss,demonstrating ultra-high operational stability and excellent repeatability.No structural modification is observed after irradiation with a total ionizing dose of almost 200 Gy,revealing an unexpectedly high radiation hardness for a metal-halide perovskite thin film.In addition,trap-assisted photoconductive gain enabled the device to achieve a record bulk sensitivity of 7.28 C Gy^(−1)cm^(−3)at 0 V,an unprecedented value in the field of thin-film-based photoconductors and photodiodes for“hard”X-rays.Finally,prototypal validation under the X-ray beam produced by a medical linear accelerator for cancer treatment is also introduced.展开更多
Exergy indicates the maximal energy that can do work effectively. Different from optimization of product quality or calculation of generic energy conservation in most previous studies, the application of exergy analys...Exergy indicates the maximal energy that can do work effectively. Different from optimization of product quality or calculation of generic energy conservation in most previous studies, the application of exergy analysis and exergy cost optimization in petrochemical industry is of great economic and environmental significance. Based on the main fractionator in Jiujiang Petrochemical Complex No. 2 FCCU, an enhanced exergy cost optimization under different operating conditions by adjusting set points of temperature and valves opening degree for flow control is studied in this paper in order to reduce exergy cost and improve the quality of energy. A steadystate optimization algorithm to enhance exergy availability and an objective function comprehensively considering exergy loss are proposed. On the basis of ensuring the quality of petroleum products, the economic benefits can be improved by optimizing the controllable variables due to the fact that exergy cost is decreased.展开更多
In this in-depth exploration, I delve into the complex implications and costs of cybersecurity breaches. Venturing beyond just the immediate repercussions, the research unearths both the overt and concealed long-term ...In this in-depth exploration, I delve into the complex implications and costs of cybersecurity breaches. Venturing beyond just the immediate repercussions, the research unearths both the overt and concealed long-term consequences that businesses encounter. This study integrates findings from various research, including quantitative reports, drawing upon real-world incidents faced by both small and large enterprises. This investigation emphasizes the profound intangible costs, such as trade name devaluation and potential damage to brand reputation, which can persist long after the breach. By collating insights from industry experts and a myriad of research, the study provides a comprehensive perspective on the profound, multi-dimensional impacts of cybersecurity incidents. The overarching aim is to underscore the often-underestimated scope and depth of these breaches, emphasizing the entire timeline post-incident and the urgent need for fortified preventative and reactive measures in the digital domain.展开更多
Due to the pressure gain combustion characteristics,the rotating detonation combustor(RDC)can enhance thermodynamic cycle efficiency.Therefore,the performance of gas-turbine engine can be further improved with this co...Due to the pressure gain combustion characteristics,the rotating detonation combustor(RDC)can enhance thermodynamic cycle efficiency.Therefore,the performance of gas-turbine engine can be further improved with this combustion technology.In the present study,the RDC operation performance with a turbine guide vane(TGV)is experimentally investigated.Hydrogen and air are used as propellants while hydrogen and air mass flow rate are about 16.1 g/s and 500 g/s and the equivalence ratio is about 1.0.A pre-detonator is used to ignite the mixture.High-frequency dynamic pressure transducers and silicon pressure sensors are employed to measure pressure oscillations and static pressure in the combustion chamber.The experimental results show that the steady propagation of rotating detonation wave(RDW)is observed in the combustion chamber and the mean propagation velocity is above 1650 m/s,reaching over 84%of theoretical Chapman-Jouguet detonation velocity.Clockwise and counterclockwise propagation directions of RDW are obtained.For clockwise propagation direction,the static pressure is about 15%higher in the combustor compared with counterclockwise propagation direction,but the RDW dominant frequency is lower.When the oblique shock wave propagates across the TGV,the pressure oscillations reduces significantly.In addition,as the detonation products flow through the TGV,the static pressure drops up to 32%and 43%for clockwise and counterclockwise propagation process respectively.展开更多
With consideration that the controller parameters may vary from the designed value when the controller is realized, based on Lyapunov stability theory, a design method of nonfragile guaranteed cost control for a class...With consideration that the controller parameters may vary from the designed value when the controller is realized, based on Lyapunov stability theory, a design method of nonfragile guaranteed cost control for a class of Delta operator-formulated uncertain time-delay systems is studied. A sufficient condition for the existence of the nonfragile guaranteed cost controller is given. A numeric example is then given to illustrate the effectiveness and the feasibility of the designed method. The results show that even if the parameters of the designed controller are of variations, the closed-loop system is still asymptotically stable and the super value of the cost function can also be obtained, while the closed-loop system will be unstable if the variations of the controller parameters are not considered when the controller is designed. The nonfragile guaranteed cost controller derived from the traditional shift operator method may cause the closed-loop system to be unstable, while the nonfragile guaranteed cost controller based on Delta operator method can avoid the unstable problem of the closed-loop system.展开更多
Relations of the 3D multi-directional derivatives are studied in this paper. These relations are applied to a geeral second-order linear elliptical operator and the corresponding expression are obtained. These relatio...Relations of the 3D multi-directional derivatives are studied in this paper. These relations are applied to a geeral second-order linear elliptical operator and the corresponding expression are obtained. These relations and expressions play important roles in the meshless finite point method.展开更多
We investigated forest road networks and forestry operations before and after mechanization on aggregated forestry operation sites. We developed equations to estimate densities of road networks with average slope angl...We investigated forest road networks and forestry operations before and after mechanization on aggregated forestry operation sites. We developed equations to estimate densities of road networks with average slope angles, operational efficiency of bunching operations with road network density, and average forwarding distances with operation site areas. Subsequently, we analyzed the effects of aggregating forests, establishing forest road networks, and mechanization on operational efficiency and costs. Six ha proved to be an appropriate operation site area with minimum operation expenses. The operation site areas of the forest owners' cooperative in this region aggregated approximately 6 ha and the cooperative conducted forestry operations on aggregated sites. Therefore, 6 ha would be an appropriate operation site area in this region. Regarding road network density, higher-density road networks increased operational expenses due to the higher direct operational expenses of strip road establishment. Therefore, road network density should be reduced to approximately 200 m.展开更多
We investigated a developed arm roll forwarder at Nasu in Tochigi Prefecture, Japan. An arm roll forwarder can only load a steel container that has been fully loaded with logs beforehand, and can later unload such a c...We investigated a developed arm roll forwarder at Nasu in Tochigi Prefecture, Japan. An arm roll forwarder can only load a steel container that has been fully loaded with logs beforehand, and can later unload such a container. Such a forwarder can shorten the loading and untoading times and improve operational efficiency. We examined two operation systems with an arm roll forwarder and a forwarder. In the first system the loading was done with a grapple-loader. In the second system the loading was done with a processor. The loading times of an arm roll forwarder were significantly tess than those of a forwarder. Because the optimal cycle times (excluding the waiting times for an arm roll for- warder) were significantly reduced, the costs of using an arm roll for- warder are lower, although the loading capacity was small and the hourly operation cost was high. The maximum operational efficiencies varied depending on forwarding distances. The second operation system with an arm roll forwarder exhibited the best operational efficiency within a 1,580-m forwarding distance, and beyond that distance it exhibited the highest operational efficiency when a forwarder was used. Similarly, the cost of operation of the system with an arm roll forwarder was the lowest within a 1,130-m forwarding distance, and beyond that distance the cost was the lowest when using the forwarder. Therefore, the arm roll for- warder is effective within a certain forwarding distance.展开更多
Edge detection is an important aspect to improve image edge quality in image processing. The purpose of edge detection is to identify the points in digital images with great brightness variation. However, the accuracy...Edge detection is an important aspect to improve image edge quality in image processing. The purpose of edge detection is to identify the points in digital images with great brightness variation. However, the accuracy of traditional edge detection methods in edge extraction is low. For the actual image, the grey edge is sometimes not very clear, the image also contains noise. The detection result of </span><span style="font-family:Verdana;">the </span><span style="font-family:Verdana;">traditional Sobel operator is relatively accurate, but the detection result is rough and sensitive to noise. To solve the above problems, this paper proposes an improved eight-direction Sobel operator based on grey relevancy degree, which combines 5</span><span style="font-family:""> </span><span style="font-family:Verdana;">×</span><span style="font-family:""> </span><span style="font-family:Verdana;">5 Sobel operator with </span><span style="font-family:Verdana;">a </span><span style="font-family:Verdana;">grey relational degree and a new eight-direction grey relevancy method. The results show that this method can detect the useful information of edge more accurately and improve the anti-noise performance. However, the drawback is that the algorithm is not automatic.展开更多
The growth of entire functions under the q-difference operators is studied inthis paper, and then some properties of Julia set of entire functions under the higher orderq-difference operators are obtained.
In this paper we establish direct local and global approximation theorems for Baskakov type operators and Szasz - Mirakjan type operators, respectively.
Background and purpose: The rising cost of health care is of concern worldwide, in particular, for cancer care. The costs of treatment, including chemotherapeutic drugs and radiotherapy, are no exceptions. The purpose...Background and purpose: The rising cost of health care is of concern worldwide, in particular, for cancer care. The costs of treatment, including chemotherapeutic drugs and radiotherapy, are no exceptions. The purpose of this study is to explore the direct medical cost of radiotherapy and the annual increasing trend of expenditures in Taiwan. Methods: This study utilized data retrieving from the original claim data of the reimbursement of the Health Insurance Research Database (HIRD) derived from Taiwan’s Health Insurance (HI) program. Detailed data on the direct medical cost within the radiotherapy process for beneficences were extracted from inpatient expenditures by admissions (DD) and ambulatory care expenditures by visits (CD) database according to the reimbursed expenditure code of radiotherapy from January 1, 2000 to December 31, 2005. Prescriptions for radiotherapy were retrieved and the direct medical costs for radiotherapy were collected based on the NHI reimbursement price list of 2005. The annual increasing trend of expenditures was also explored according to the perspective of Bureau Health Insurance of Taiwan. Results: The total direct medical costs of radiotherapy for cancer patients were increasing from 2000 to 2005, which were estimated to US $7.80 million, US $8.09 million, US $7.58 million, US $10.7 million, US $12.2 million and US $15.9 million in 2000, 2001, 2002, 2003, 2004 and 2005, respectively. The increased percentage corresponded to the total healthcare expenditures claimed was increased substantially from 0.82% in 2000 to 1.22% in 2005. The total direct medical costs within the radiotherapy process were also increased gradually if identified by different types of radiotherapy and teaching hospital levels. The direct medical costs attribute to radiotherapy, compared to total health care expenditures in Taiwan, were similar to the costs of anticancer drugs for cancer patients annually. Conclusions: The direct medical costs of radiation therapy increased substantially each year. Further cost analysis on radiation therapy is needed in years beyond 2005.展开更多
Due to its chronic nature with severe complications, diabetes needs costly prolonged treatment and care. The high economic burden of diabetes is particularly threatening low and middle income countries. World-wide, st...Due to its chronic nature with severe complications, diabetes needs costly prolonged treatment and care. The high economic burden of diabetes is particularly threatening low and middle income countries. World-wide, studies have shown that the cost of diabetes per person is much higher than the per capita health expenditure. This study is the first to estimate the direct and indirect cost of diabetes in Morocco. The direct cost of diabetes was computed by assuming three scenarios of prices (low, medium and high) due to different prices of insulin, oral drugs and other items used in diabetes treatment and care. Indirect costs of diabetes were estimated by the lifetime forgone earnings caused by premature death and disability due to diabetes. The direct cost of diabetes in Morocco was estimated to be between US $0.47 and US $1.5 billion whereas the indirect cost was estimated to be around US $2 billion accounting for 57% of the total cost of diabetes under the high cost scenario, 69% under the medium scenario and 81% under the low cost scenario. The average per capita indirect cost was estimated to be US $1113, relatively higher than the direct cost of diabetes which was seen to vary from US$ 259 to US $830. The results yielded by this study were compared to those obtained by similar studies in different regions and countries of the world. As a conclusion, the findings of this study indicate a high economic burden of diabetes and stress the importance that Moroccan health decision makers should give to sensitisation, early diagnosis and treatment of diabetes especially with the crucial growing trend of diabetes prevalence.展开更多
Introduction: Malaria is both a disease caused by poverty and a cause of poverty. Malaria is the leading cause of morbidity and mortality in Mali and is among the ten countries with the highest number of malaria cases...Introduction: Malaria is both a disease caused by poverty and a cause of poverty. Malaria is the leading cause of morbidity and mortality in Mali and is among the ten countries with the highest number of malaria cases and deaths. The objective was to estimate the direct economic cost borne by families in the treatment of severe malaria in children aged 0 - 5 years at the CSREF in Fana. Methodology: The study was cross-sectional, conducted from July 2017 to June 2018 with inclusion criteria and prospective data collection. The methodology was based on estimating the direct economic cost of severe malaria. Results: The sample consisted of 109 cases out of a total of 944 hospitalizations;59% of whom were boys and the 25 - 36 month age group was the most affected. The complications frequently encountered were severe anemia (50 cases) or 45.8%;convulsions (35 cases) or 32.1% and finally severe sepsis (8 cases) or 7.3%. The average direct cost was 25,324 Franc CFA (58.95 US Dollars) of which 66% represented the costs of medicines and consumables against 4% for the consultation. This cost was more than half the minimum wage in Mali. Conclusion: Despite the difficulties in estimating the cost in hospitals, the results obtained give us an estimate of the economic burden borne by families in the management of severe malaria cases among children in the district of Fana. Support is needed for parents in the fight against malaria in rural Mali.展开更多
AIM: To define the cost-effectiveness of strategies, including endoscopy and immunosuppression, to prevent endoscopic recurrence of Crohn's disease following intestinal resection.METHODS: In the "POCER" ...AIM: To define the cost-effectiveness of strategies, including endoscopy and immunosuppression, to prevent endoscopic recurrence of Crohn's disease following intestinal resection.METHODS: In the "POCER" study patients undergoing intestinal resection were treated with post-operative drug therapy. Two thirds were randomized to active care(6 mo colonoscopy and drug intensification for endoscopic recurrence) and one third to drug therapy without early endoscopy. Colonoscopy at 18 mo and faecal calprotectin(FC) measurement were used to assess disease recurrence. Administrative data, chart review and patient questionnaires were collected prospectively over 18 mo.RESULTS: Sixty patients(active care n = 43, standardcare n = 17) were included from one health service. Median total health care cost was $6440 per patient. Active care cost $4824 more than standard care over 18 mo. Medication accounted for 78% of total cost, of which 90% was for adalimumab. Median health care cost was higher for those with endoscopic recurrence compared to those inremission [ $ 26347( IQR 25045-27485) vs $2729(IQR 1182-5215), P < 0.001]. FC to select patients for colonoscopy could reduce cost by $1010 per patient over 18 mo. Active care was associated with 18% decreased endoscopic recurrence, costing $861 for each recurrence prevented. CONCLUSION: Post-operative management strategies are associated with high cost, primarily medication related. Calprotectin use reduces costs. The long term cost-benefit of these strategies remains to be evaluated.展开更多
On the basis of analysis and selection of factors influencing operation cost of coal resources development, fuzzy set method and artificial neural network (ANN) were adopted to set up the classification analysis model...On the basis of analysis and selection of factors influencing operation cost of coal resources development, fuzzy set method and artificial neural network (ANN) were adopted to set up the classification analysis model of coal resources. The collected samples were classified by using this model. Meanwhile, the pattern recognition model for classifying of the coal resources was built according to the factors influencing operation cost. Based on the results achieved above, in the light of the theory of information diffusion, the calculation model for operation cost of coal resources development has been presented and applied in practice, showing that these models are reasonable.展开更多
文摘AIM:To establish a recording system with a direct view of the surgeon to supplement video recording under an operating microscope,which lacks information on the movement and position of the surgeon’s hands,and to facilitate the reproduction of a skilled surgeon’s technique by a surgeon in training.METHODS:A small camera was attached to the operating microscope with a custom adapter.Microscopic surgeon’s view and direct surgeon’s view through this new camera were recorded in the surgical recording system.Both movies were synchronized and analyzed how do surgeons handle the instruments.RESULTS:A small camera attached to the operating microscope allowed the surgeon’s hands motion to be recorded without interfering with the surgeon’s movements.Different surgeons used different methods to manipulate the ultrasound handpiece and the irrigation/aspiration device.Even in the simple paracentesis procedure,different surgeons used different methods.Surgeons-in-training were able to identify and improve their weaknesses by watching synchronized movies of their hand motions and microscopic view.CONCLUSION:Simultaneous recording the surgical field out of the operating microscopic view by a small camera set on the microscope is comprehensive and improves surgeons-in-training understanding and learning surgeries.
文摘The adoption of new technologies often represents a crucial component of firms' investment decisions. This paper studies a dynamic duopoly model in which two firms compete in adoption of current technology with a further new technology anticipated. Here it is assumed that the operating costs are not zero which has more explanatory power of the real world. There exist three kinds of equilibria that may occur in adoption of current technology, which mainly depends on the level of operating costs and the first-move advantage. It shows that the faster technological substitution or innovation encourages the leader to invest earlier while induces the follower to invest later. Furthermore,like the investment costs,with the increase of operating costs the follower tends to invest later while the leader tends to invest earlier ,the investment thresholds are more sensitive to the change of operating costs than that of investment costs.
基金the supports provided by National Iranian Oil Engineering and Construction Company(NIOEC)。
文摘A continuous-flow ultrasound-assisted oxidative desulfurization(UAOD)of partially hydro-treated diesel has been investigated using hydrogen peroxide-formic acid as simple and easy to apply oxidation system.The effects of different operating parameters of oxidation stage including residence time(2–24 min),formic acid to sulfur molar ratio(10–150),and oxidant to sulfur molar ratio(5–35)on the sulfur removal have been studied using response surface methodology(RSM)based on Box–Behnken design.Considering the operating costs of the continuous-flow oxidation stage including chemical and electrical energy consumption,the appropriate values of operating parameters were selected as follows:residence time of 16 min,the formic acid to sulfur molar ratio of 54.47,and the oxidant to sulfur molar ratio of 8.24.In these conditions,the sulfur removal and the volume ratio of the hydrocarbon phase to the aqueous phase were 86.90%and 4.34,respectively.By drastic reduction in the chemical consumption in the oxidation stage,the volume ratio of the hydrocarbon phase to the aqueous phase was increased up to 10.Therefore,the formic acid to sulfur molar ratio and the oxidant to sulfur molar ratio were obtained 23.64 and 3.58,respectively,which lead to sulfur removal of 84.38%with considerable improvements on the operating cost of oxidation stage in comparison with the previous works.
基金supported by the project“PARIDE”(Perovskite Advanced Radiotherapy&Imaging Detectors),funded under the Regional Research and Innovation Programme POR-FESR Lazio 2014-2020(project number:A0375-2020-36698).
文摘Metal-halide perovskites are revolutionizing the world of X-ray detectors,due to the development of sensitive,fast,and cost-effective devices.Self-powered operation,ensuring portability and low power consumption,has also been recently demonstrated in both bulk materials and thin films.However,the signal stability and repeatability under continuous X-ray exposure has only been tested up to a few hours,often reporting degradation of the detection performance.Here it is shown that self-powered direct X-ray detectors,fabricated starting from a FAPbBr_(3)submicrometer-thick film deposition onto a mesoporous TiO_(2)scaffold,can withstand a 26-day uninterrupted X-ray exposure with negligible signal loss,demonstrating ultra-high operational stability and excellent repeatability.No structural modification is observed after irradiation with a total ionizing dose of almost 200 Gy,revealing an unexpectedly high radiation hardness for a metal-halide perovskite thin film.In addition,trap-assisted photoconductive gain enabled the device to achieve a record bulk sensitivity of 7.28 C Gy^(−1)cm^(−3)at 0 V,an unprecedented value in the field of thin-film-based photoconductors and photodiodes for“hard”X-rays.Finally,prototypal validation under the X-ray beam produced by a medical linear accelerator for cancer treatment is also introduced.
基金Supported by the National Natural Science Foundation of China(61590924,61673273,61521063)
文摘Exergy indicates the maximal energy that can do work effectively. Different from optimization of product quality or calculation of generic energy conservation in most previous studies, the application of exergy analysis and exergy cost optimization in petrochemical industry is of great economic and environmental significance. Based on the main fractionator in Jiujiang Petrochemical Complex No. 2 FCCU, an enhanced exergy cost optimization under different operating conditions by adjusting set points of temperature and valves opening degree for flow control is studied in this paper in order to reduce exergy cost and improve the quality of energy. A steadystate optimization algorithm to enhance exergy availability and an objective function comprehensively considering exergy loss are proposed. On the basis of ensuring the quality of petroleum products, the economic benefits can be improved by optimizing the controllable variables due to the fact that exergy cost is decreased.
文摘In this in-depth exploration, I delve into the complex implications and costs of cybersecurity breaches. Venturing beyond just the immediate repercussions, the research unearths both the overt and concealed long-term consequences that businesses encounter. This study integrates findings from various research, including quantitative reports, drawing upon real-world incidents faced by both small and large enterprises. This investigation emphasizes the profound intangible costs, such as trade name devaluation and potential damage to brand reputation, which can persist long after the breach. By collating insights from industry experts and a myriad of research, the study provides a comprehensive perspective on the profound, multi-dimensional impacts of cybersecurity incidents. The overarching aim is to underscore the often-underestimated scope and depth of these breaches, emphasizing the entire timeline post-incident and the urgent need for fortified preventative and reactive measures in the digital domain.
基金the National Natural Science Foundation of China(No.11702143 and 11802137)the Fundamental Research Funds for the Central Universities(No.30918011343 and 30919011259).
文摘Due to the pressure gain combustion characteristics,the rotating detonation combustor(RDC)can enhance thermodynamic cycle efficiency.Therefore,the performance of gas-turbine engine can be further improved with this combustion technology.In the present study,the RDC operation performance with a turbine guide vane(TGV)is experimentally investigated.Hydrogen and air are used as propellants while hydrogen and air mass flow rate are about 16.1 g/s and 500 g/s and the equivalence ratio is about 1.0.A pre-detonator is used to ignite the mixture.High-frequency dynamic pressure transducers and silicon pressure sensors are employed to measure pressure oscillations and static pressure in the combustion chamber.The experimental results show that the steady propagation of rotating detonation wave(RDW)is observed in the combustion chamber and the mean propagation velocity is above 1650 m/s,reaching over 84%of theoretical Chapman-Jouguet detonation velocity.Clockwise and counterclockwise propagation directions of RDW are obtained.For clockwise propagation direction,the static pressure is about 15%higher in the combustor compared with counterclockwise propagation direction,but the RDW dominant frequency is lower.When the oblique shock wave propagates across the TGV,the pressure oscillations reduces significantly.In addition,as the detonation products flow through the TGV,the static pressure drops up to 32%and 43%for clockwise and counterclockwise propagation process respectively.
基金supported by the Natural Science Foundation of Fujian Province (No.2008J04016)
文摘With consideration that the controller parameters may vary from the designed value when the controller is realized, based on Lyapunov stability theory, a design method of nonfragile guaranteed cost control for a class of Delta operator-formulated uncertain time-delay systems is studied. A sufficient condition for the existence of the nonfragile guaranteed cost controller is given. A numeric example is then given to illustrate the effectiveness and the feasibility of the designed method. The results show that even if the parameters of the designed controller are of variations, the closed-loop system is still asymptotically stable and the super value of the cost function can also be obtained, while the closed-loop system will be unstable if the variations of the controller parameters are not considered when the controller is designed. The nonfragile guaranteed cost controller derived from the traditional shift operator method may cause the closed-loop system to be unstable, while the nonfragile guaranteed cost controller based on Delta operator method can avoid the unstable problem of the closed-loop system.
基金Supported by the National Natural Science Foundation of China 1060100910701014+1 种基金10871029)the Foundation of China Academy of Engineering Physics (2007B09008)
文摘Relations of the 3D multi-directional derivatives are studied in this paper. These relations are applied to a geeral second-order linear elliptical operator and the corresponding expression are obtained. These relations and expressions play important roles in the meshless finite point method.
文摘We investigated forest road networks and forestry operations before and after mechanization on aggregated forestry operation sites. We developed equations to estimate densities of road networks with average slope angles, operational efficiency of bunching operations with road network density, and average forwarding distances with operation site areas. Subsequently, we analyzed the effects of aggregating forests, establishing forest road networks, and mechanization on operational efficiency and costs. Six ha proved to be an appropriate operation site area with minimum operation expenses. The operation site areas of the forest owners' cooperative in this region aggregated approximately 6 ha and the cooperative conducted forestry operations on aggregated sites. Therefore, 6 ha would be an appropriate operation site area in this region. Regarding road network density, higher-density road networks increased operational expenses due to the higher direct operational expenses of strip road establishment. Therefore, road network density should be reduced to approximately 200 m.
文摘We investigated a developed arm roll forwarder at Nasu in Tochigi Prefecture, Japan. An arm roll forwarder can only load a steel container that has been fully loaded with logs beforehand, and can later unload such a container. Such a forwarder can shorten the loading and untoading times and improve operational efficiency. We examined two operation systems with an arm roll forwarder and a forwarder. In the first system the loading was done with a grapple-loader. In the second system the loading was done with a processor. The loading times of an arm roll forwarder were significantly tess than those of a forwarder. Because the optimal cycle times (excluding the waiting times for an arm roll for- warder) were significantly reduced, the costs of using an arm roll for- warder are lower, although the loading capacity was small and the hourly operation cost was high. The maximum operational efficiencies varied depending on forwarding distances. The second operation system with an arm roll forwarder exhibited the best operational efficiency within a 1,580-m forwarding distance, and beyond that distance it exhibited the highest operational efficiency when a forwarder was used. Similarly, the cost of operation of the system with an arm roll forwarder was the lowest within a 1,130-m forwarding distance, and beyond that distance the cost was the lowest when using the forwarder. Therefore, the arm roll for- warder is effective within a certain forwarding distance.
文摘Edge detection is an important aspect to improve image edge quality in image processing. The purpose of edge detection is to identify the points in digital images with great brightness variation. However, the accuracy of traditional edge detection methods in edge extraction is low. For the actual image, the grey edge is sometimes not very clear, the image also contains noise. The detection result of </span><span style="font-family:Verdana;">the </span><span style="font-family:Verdana;">traditional Sobel operator is relatively accurate, but the detection result is rough and sensitive to noise. To solve the above problems, this paper proposes an improved eight-direction Sobel operator based on grey relevancy degree, which combines 5</span><span style="font-family:""> </span><span style="font-family:Verdana;">×</span><span style="font-family:""> </span><span style="font-family:Verdana;">5 Sobel operator with </span><span style="font-family:Verdana;">a </span><span style="font-family:Verdana;">grey relational degree and a new eight-direction grey relevancy method. The results show that this method can detect the useful information of edge more accurately and improve the anti-noise performance. However, the drawback is that the algorithm is not automatic.
基金supported by the National Natural Science Foundation of China(11571049,11101048)
文摘The growth of entire functions under the q-difference operators is studied inthis paper, and then some properties of Julia set of entire functions under the higher orderq-difference operators are obtained.
文摘In this paper we establish direct local and global approximation theorems for Baskakov type operators and Szasz - Mirakjan type operators, respectively.
文摘Background and purpose: The rising cost of health care is of concern worldwide, in particular, for cancer care. The costs of treatment, including chemotherapeutic drugs and radiotherapy, are no exceptions. The purpose of this study is to explore the direct medical cost of radiotherapy and the annual increasing trend of expenditures in Taiwan. Methods: This study utilized data retrieving from the original claim data of the reimbursement of the Health Insurance Research Database (HIRD) derived from Taiwan’s Health Insurance (HI) program. Detailed data on the direct medical cost within the radiotherapy process for beneficences were extracted from inpatient expenditures by admissions (DD) and ambulatory care expenditures by visits (CD) database according to the reimbursed expenditure code of radiotherapy from January 1, 2000 to December 31, 2005. Prescriptions for radiotherapy were retrieved and the direct medical costs for radiotherapy were collected based on the NHI reimbursement price list of 2005. The annual increasing trend of expenditures was also explored according to the perspective of Bureau Health Insurance of Taiwan. Results: The total direct medical costs of radiotherapy for cancer patients were increasing from 2000 to 2005, which were estimated to US $7.80 million, US $8.09 million, US $7.58 million, US $10.7 million, US $12.2 million and US $15.9 million in 2000, 2001, 2002, 2003, 2004 and 2005, respectively. The increased percentage corresponded to the total healthcare expenditures claimed was increased substantially from 0.82% in 2000 to 1.22% in 2005. The total direct medical costs within the radiotherapy process were also increased gradually if identified by different types of radiotherapy and teaching hospital levels. The direct medical costs attribute to radiotherapy, compared to total health care expenditures in Taiwan, were similar to the costs of anticancer drugs for cancer patients annually. Conclusions: The direct medical costs of radiation therapy increased substantially each year. Further cost analysis on radiation therapy is needed in years beyond 2005.
文摘Due to its chronic nature with severe complications, diabetes needs costly prolonged treatment and care. The high economic burden of diabetes is particularly threatening low and middle income countries. World-wide, studies have shown that the cost of diabetes per person is much higher than the per capita health expenditure. This study is the first to estimate the direct and indirect cost of diabetes in Morocco. The direct cost of diabetes was computed by assuming three scenarios of prices (low, medium and high) due to different prices of insulin, oral drugs and other items used in diabetes treatment and care. Indirect costs of diabetes were estimated by the lifetime forgone earnings caused by premature death and disability due to diabetes. The direct cost of diabetes in Morocco was estimated to be between US $0.47 and US $1.5 billion whereas the indirect cost was estimated to be around US $2 billion accounting for 57% of the total cost of diabetes under the high cost scenario, 69% under the medium scenario and 81% under the low cost scenario. The average per capita indirect cost was estimated to be US $1113, relatively higher than the direct cost of diabetes which was seen to vary from US$ 259 to US $830. The results yielded by this study were compared to those obtained by similar studies in different regions and countries of the world. As a conclusion, the findings of this study indicate a high economic burden of diabetes and stress the importance that Moroccan health decision makers should give to sensitisation, early diagnosis and treatment of diabetes especially with the crucial growing trend of diabetes prevalence.
文摘Introduction: Malaria is both a disease caused by poverty and a cause of poverty. Malaria is the leading cause of morbidity and mortality in Mali and is among the ten countries with the highest number of malaria cases and deaths. The objective was to estimate the direct economic cost borne by families in the treatment of severe malaria in children aged 0 - 5 years at the CSREF in Fana. Methodology: The study was cross-sectional, conducted from July 2017 to June 2018 with inclusion criteria and prospective data collection. The methodology was based on estimating the direct economic cost of severe malaria. Results: The sample consisted of 109 cases out of a total of 944 hospitalizations;59% of whom were boys and the 25 - 36 month age group was the most affected. The complications frequently encountered were severe anemia (50 cases) or 45.8%;convulsions (35 cases) or 32.1% and finally severe sepsis (8 cases) or 7.3%. The average direct cost was 25,324 Franc CFA (58.95 US Dollars) of which 66% represented the costs of medicines and consumables against 4% for the consultation. This cost was more than half the minimum wage in Mali. Conclusion: Despite the difficulties in estimating the cost in hospitals, the results obtained give us an estimate of the economic burden borne by families in the management of severe malaria cases among children in the district of Fana. Support is needed for parents in the fight against malaria in rural Mali.
文摘AIM: To define the cost-effectiveness of strategies, including endoscopy and immunosuppression, to prevent endoscopic recurrence of Crohn's disease following intestinal resection.METHODS: In the "POCER" study patients undergoing intestinal resection were treated with post-operative drug therapy. Two thirds were randomized to active care(6 mo colonoscopy and drug intensification for endoscopic recurrence) and one third to drug therapy without early endoscopy. Colonoscopy at 18 mo and faecal calprotectin(FC) measurement were used to assess disease recurrence. Administrative data, chart review and patient questionnaires were collected prospectively over 18 mo.RESULTS: Sixty patients(active care n = 43, standardcare n = 17) were included from one health service. Median total health care cost was $6440 per patient. Active care cost $4824 more than standard care over 18 mo. Medication accounted for 78% of total cost, of which 90% was for adalimumab. Median health care cost was higher for those with endoscopic recurrence compared to those inremission [ $ 26347( IQR 25045-27485) vs $2729(IQR 1182-5215), P < 0.001]. FC to select patients for colonoscopy could reduce cost by $1010 per patient over 18 mo. Active care was associated with 18% decreased endoscopic recurrence, costing $861 for each recurrence prevented. CONCLUSION: Post-operative management strategies are associated with high cost, primarily medication related. Calprotectin use reduces costs. The long term cost-benefit of these strategies remains to be evaluated.
文摘On the basis of analysis and selection of factors influencing operation cost of coal resources development, fuzzy set method and artificial neural network (ANN) were adopted to set up the classification analysis model of coal resources. The collected samples were classified by using this model. Meanwhile, the pattern recognition model for classifying of the coal resources was built according to the factors influencing operation cost. Based on the results achieved above, in the light of the theory of information diffusion, the calculation model for operation cost of coal resources development has been presented and applied in practice, showing that these models are reasonable.