We apply reweighted inversion focusing to full tensor gravity gradiometry data using message-passing interface (MPI) and compute unified device architecture (CUDA) parallel computing algorithms, and then combine M...We apply reweighted inversion focusing to full tensor gravity gradiometry data using message-passing interface (MPI) and compute unified device architecture (CUDA) parallel computing algorithms, and then combine MPI with CUDA to formulate a hybrid algorithm. Parallel computing performance metrics are introduced to analyze and compare the performance of the algorithms. We summarize the rules for the performance evaluation of parallel algorithms. We use model and real data from the Vinton salt dome to test the algorithms. We find good match between model efficiency and feasibility of parallel computing gravity gradiometry data. and real density data, and verify the high algorithms in the inversion of full tensor展开更多
Based on the basic content of advanced technology,safety and reliability, and economic reasonability and the definition of mine ventilation system, 16 assessment indexes of ventilation system are put forward from the ...Based on the basic content of advanced technology,safety and reliability, and economic reasonability and the definition of mine ventilation system, 16 assessment indexes of ventilation system are put forward from the point of 8 aspects such as mine ventilation power, ventilation network, ventilation equipments, ventilation quality, ventilation monitoring, capacity of preventing and fighting disaster, ventilation consumption of power, and the capacity of ventila- tion system. A new assessment index system is put forward and has a good effect after being applied in coal mines.展开更多
AIM:To prospectively assess the eff icacy and safety of stapled trans-anal rectal resection(STARR) compared to standard conservative treatment,and whether preoperative symptoms and findings at defecography and anorect...AIM:To prospectively assess the eff icacy and safety of stapled trans-anal rectal resection(STARR) compared to standard conservative treatment,and whether preoperative symptoms and findings at defecography and anorectal manometry can predict the outcome of STARR.METHODS:Thirty patients(Female,28;age:51 ± 9 years) with rectocele or rectal intussusception,a defecation disorder,and functional constipation were submitted for STARR.Thirty comparable patients(Female,30;age 53 ± 13 years),who presented with symptoms of rectocele or rectal intussusception and were treated with macrogol,were assessed.Patients were interviewed with a standardized questionnaire at study enrollment and 38 ± 18 mo after the STARR procedure or during macrogol treatment.A responder was def ined as an absence of the Rome Ⅲ diagnostic criteria for functional constipation.Defecography and rectoanal manometry were performed before and after the STARR procedure in 16 and 12 patients,respectively.RESULTS:After STARR,53% of patients were responders;during conservative treatment,75% were responders.After STARR,30% of the patients reported the use of laxatives,17% had intermittent anal pain,13% had anal leakage,13% required digital facilitation,6% experienced defecatory urgency,6% experienced fecal incontinence,and 6% required re-intervention.During macrogol therapy,23% of the patients complained of abdominal bloating and 13% of borborygmi,and 3% required digital facilitation.No preoperative symptom,defecographic,or manometric finding predicted the outcome of STARR.Post-operative defecography showed a statistically significant reduction(P < 0.05) of the rectal diameter and rectocele.The postoperative anorectal manometry showed that anal pressure and rectal sensitivity were not significantly modified,and that rectal compliance was reduced(P = 0.01).CONCLUSION:STARR is not better and is less safe than macrogol in the treatment of defecation disorders.It could be considered as an alternative therapy in patients unresponsive to macrogol.展开更多
AIM:To study the safety and effectiveness of propofol sedation for outpatient colonoscopy.METHODS:Propofol was given by bolus injection with an age-adjusted standard protocol consisting of 60 mg for patients < 70 y...AIM:To study the safety and effectiveness of propofol sedation for outpatient colonoscopy.METHODS:Propofol was given by bolus injection with an age-adjusted standard protocol consisting of 60 mg for patients < 70 years old,40 mg for patients age 70-89 years,and 20 mg for those ≥ 90 years,and additional injections of 20 mg propofol were given up to a maximum of 200 mg.The principal parameters were the occurrence of adverse events within 24 h after colonoscopy and overall satisfaction for this procedure.Secondary parameters included successful procedure,respiratory depression,and other complications.RESULTS:Consecutive patients were entered prospectively and all 2101 entered successfully completed outpatient colonoscopy.The mean dose of propofol used was 96.4 mg(range 40-200 mg).Younger patients required higher doses of propofol than older patients(20-40 years vs ≥ 61 years:115.3 ± 32 mg vs 89.7 ± 21 mg,P < 0.001).Transient supplemental oxygen supply was needed by five patients(0.2%);no other complications occurred.The questionnaires were completed by 1820(87%) of 2101 patients and most rated their overall satisfaction as excellent(80%) or good(17%).The majority(65%) of patients drove home or to their office after their colonoscopy.Most(99%) were willing to repeat the same procedure.No incidents occurred within 24 h after colonoscopy.CONCLUSION:Propofol sedation using a dose < 200 mg proved both safe and practical for outpatient colonoscopy.展开更多
In mine ventilation networks, the reasonable airflow distribution is very important for the production safety and economy. Three basic problems of the natural, full-controlled and semi-controlled splitting were review...In mine ventilation networks, the reasonable airflow distribution is very important for the production safety and economy. Three basic problems of the natural, full-controlled and semi-controlled splitting were reviewed in the paper. Aiming at the high difficulty semi-controlled splitting problem, the general nonlinear multi-objectives optimization mathematical model with constraints was established based on the theory of mine ventilation networks. A new algorithm, which combined the improved differential evaluation and the critical path method (CPM) based on the multivariable separate solution strategy, was put forward to search for the global optimal solution more efficiently. In each step of evolution, the feasible solutions of air quantity distribution are firstly produced by the improved differential evolu- tion algorithm, and then the optimal solutions of regulator pressure drop are obtained by the CPM. Through finite steps iterations, the optimal solution can be given. In this new algorithm, the population of feasible solutions were sorted and grouped for enhancing the global search ability and the individuals in general group were randomly initialized for keeping diversity. Meanwhile, the individual neighbor- hood in the fine group which may be closely to the optimal solutions were searched locally and slightly for achieving a balance between global searching and local searching, thus improving the convergence rate. The computer program was developed based on this method. Finally, the two ventilation networks with single-fan and multi-fans were solved. The results show that this algorithm has advantages of high effectiveness, fast convergence, good robustness and flexibility. This computer program could be used to solve lar^e-scale ~eneralized ventilation networks o^timization problem in the future.展开更多
When simulating the propagation of seismic waves in some special structures,such as tunnels and boreholes,finite difference forward modeling in the polar system has higher accuracy than the traditional Cartesian syste...When simulating the propagation of seismic waves in some special structures,such as tunnels and boreholes,finite difference forward modeling in the polar system has higher accuracy than the traditional Cartesian system.In actual situations,the polar space is the most irregular.To solve this problem,a forward modeling method for an irregular polar coordinate system is proposed to improve the simulation accuracy.First,an irregular surface of the polar space was meshed into an irregular polar system.After the transformation,the undulating surface was mapped into a plane one,and the wavefield was then computed in an irregular polar system.The Lebedev staggered grid was used to solve the wave equations in the irregular polar system.In addition,the artificial absorption boundary,cylindrical free boundary,and circumferential boundary conditions were used to absorb the boundary reflection.We selected three polar space models to demonstrate the new method in this study.The results show that the proposed elastic simulation method in an irregular polar coordinate system can produce more accurate and stable simulation results when modeling seismic wave propagation in an irregular polar space.Elastic full waveform inversion further shows that the irregular polar system elastic simulation method can accurately simulate the wavefield in an undulating polar space.展开更多
A mine ventilation system has a deterministic function for the safety of coal production and for the control of mine accidents. So, it has an important meaning to evaluate the security of a mine ventilation system. Th...A mine ventilation system has a deterministic function for the safety of coal production and for the control of mine accidents. So, it has an important meaning to evaluate the security of a mine ventilation system. This paper studied the evaluation index system of the security of a mine ventilation system, and the security of a mine ventilation system was described quantitatively in the safety degree. Finally, an example of the security evaluation was given.展开更多
Based on Mohr-Coulomb (M-C) criterion, the parameters of Druker-Prager (D-P) criterion for geomaterial were determined under non-associated flow rule, and thus a new D-P type criterion was presented. Two assumptio...Based on Mohr-Coulomb (M-C) criterion, the parameters of Druker-Prager (D-P) criterion for geomaterial were determined under non-associated flow rule, and thus a new D-P type criterion was presented. Two assumptions were employed during the derivation: 1) principal strains by M-C model and D-P model are equal, and 2) the material is under plane strain condition. Based on the analysis of the surface on rt plane, it is found that the proposed D-P type criterion is better than the D-P criterion with M-C circumscribed circle or M-C inscribed circle, and is applicable for stress Lode angle less than zero. By comparing the predicted results with the test data of sand under plane strain condition and other D-P criteria, the proposed criterion is verified and agrees well with the test data, which is further proved to be better than other D--P type criteria in certain range of Lode angle. The criterion was compiled into a finite difference package FLAC3D by user-subroutine, and was used to analyze the stability of a slope by strength reduction method. The predicted slope safety factor from the proposed criterion agrees well with that by Spencer method, and it is more accurate than that from classic D-P criteria.展开更多
The chromatically uniqueness of bipartite graphs K (m, n) - A(]A] = 2) was studied. With comparing the numbers of partitions into r color classes of two chromatically equivalent graphs, one general numerical condi...The chromatically uniqueness of bipartite graphs K (m, n) - A(]A] = 2) was studied. With comparing the numbers of partitions into r color classes of two chromatically equivalent graphs, one general numerical condition guaranteeing that K( m, n) - A ( I A ] = 2) is chromatically unique were obtained. This covers and improves the former correlative results.展开更多
The safety status of the coal mines is closely correlated with the operating status and its changes of the whole working system in the coal mines, and the safety system is the sub system of the whole production system...The safety status of the coal mines is closely correlated with the operating status and its changes of the whole working system in the coal mines, and the safety system is the sub system of the whole production system. In this paper, based on the analysis of the complicacy of the safety sub system and its affecting factors, the theory basis of the indexes system of the safety assessment was studied, including the establishing principles of the indexes system , the structure of the indexes system, the determining methods of the assessment indexes. The complete indexes system was established for the safety assessment of the coal mines in the paper.展开更多
The basic element in any sustainable dam project is safety, which includes the following safety elements: O structural safety, dam safety monitoring, operational safety and maintenance, and emergency planning. Lon...The basic element in any sustainable dam project is safety, which includes the following safety elements: O structural safety, dam safety monitoring, operational safety and maintenance, and emergency planning. Long-term safety primarily includes the analysis of all hazards affecting the project; that is, hazards from the natural environment, hazards from the man-made environment, and project-specific and site-specific hazards. The special features of the seismic safety of dams are discussed. Large dams were the first structures to be systematically designed against earthquakes, starting in the 1930s. How- ever, the seismic safety of older dams is unknown, as most were designed using seismic design criteria and methods of dynamic analysis that are considered obsolete today. Therefore, we need to reevaluate the seismic safety of existing dams based on current state-of-the-art practices and rehabilitate deficient dams. For large dams, a site-specific seismic hazard analysis is usually recommended. Today, large dams and the safety-relevant elements used for controlling the reservoir after a strong earthquake must be able to withstand the ground motions of a safety evaluation earthquake. The ground motion parameters can be determined either by a probabilistic or a deterministic seismic hazard analysis. During strong earthquakes, inelastic deformations may occur in a dam; therefore, the seismic analysis has to be car- ried out in the time domain. Furthermore, earthquakes create multiple seismic hazards for dams such as ground shaking, fault movements, mass movements, and others. The ground motions needed by the dam engineer are not real earthquake ground motions but models of the ground motion, which allow the safe design of dams. It must also be kept in mind that darn safety evaluations must be carried out several times during the long life of large storage dams. These features are discussed in this paper.展开更多
Linkage disequilibrium(LD) can be applied for mapping the actual genes responsible for variation of economically important traits through association mapping.The feasibility and efficacy of association studies are str...Linkage disequilibrium(LD) can be applied for mapping the actual genes responsible for variation of economically important traits through association mapping.The feasibility and efficacy of association studies are strongly dependent on the extent of LD which determines the number and density of markers in the studied population,as well as the experimental design for an association analysis.In this study,we first characterized the extent of LD in a wild population and a cultured mass-selected line of Pacific oyster(Crassostrea gigas).A total of 88 wild and 96 cultured individuals were selected to assess the level of genome-wide LD with 53 microsatellites,respectively.For syntenic marker pairs,no significant association was observed in the wild population;however,three significant associations occurred in the cultured population,and the significant LD extended up to 12.7 c M,indicating that strong artificial selection is a key force for substantial increase of genome-wide LD in cultured population.The difference of LD between wild and cultured populations showed that association studies in Pacific oyster can be achieved with reasonable marker densities at a relatively low cost by choosing an association mapping population.Furthermore,the frequent occurrence of LD between non-syntenic loci and rare alleles encourages the joint application of linkage analysis and LD mapping when mapping genes in oyster.The information on the linkage disequilibrium in the cultured population is useful for future association mapping in oyster.展开更多
Due to the limited amount of funds available for bridge inspection, maintenance and rehabilitation, the evaluation of load capacity for existing bridges is crucial to the Louisiana Department of Transportation and Dev...Due to the limited amount of funds available for bridge inspection, maintenance and rehabilitation, the evaluation of load capacity for existing bridges is crucial to the Louisiana Department of Transportation and Development. This paper includes the development of a methodology to assess the economic impact of overweight vehicles with permits, hauling Louisiana harvest products on state bridges. The proposed higher truck loads are applied on the existing bridges and their effects are determined using deterministic load capacity evaluations as well as reliability assessments. The target rehability level is derived from bridge structures designed to satisfy AASHTO Standard Design Specifications and also satisfy safe and adequate performance levels. The amount of harvest produced is used to select a representative sample of bridges to provide specific examples of expected changes in load ratings and safety levels. The bridges include simple and continuous span behavior. Strength and serviceability criteria are investigated under current legal loads and the expected changes, due to the proposed new weights, are determined. The results are used to assess the cost of crossing a bridge and the permit fees for the proposed truck weight regulation.展开更多
The permeability and sorptivity properties of the two prestressed concrete containment buildings (PCCBs) of a nuclear power plant in South China, which had been under operation for 5 years, were measured by using th...The permeability and sorptivity properties of the two prestressed concrete containment buildings (PCCBs) of a nuclear power plant in South China, which had been under operation for 5 years, were measured by using the autoclam permeability system. The air permeability, sorptivity and water permeability indexes of No.1 PCCB are smaller than or equal to 0.11 ln(102 Pa)/min, 0.98×10 ^7 m3/minl/2 and 1.93×10 ^7 m3/min1/2, respectively, and the air permeability, sorptivity and water permeability indexes of No.2 PCCB are smaller than or equal to 0.17 In(102 Pa)/min, 1.6×10 ^7 m3/min1/2 and 4.43 ×10 ^7 m3/min1/2, respectively. Based on the criteria for evaluating the protective quality of concrete structures in terms of their permeability and sorptivity properties, proposed by the research organization of the autoclam permeability system, the protective quality of No. 1 PCCB is still in very good grade and that of No.2 PCCB is not in very good grade but in good grade, and the in-service inspection of the protective quality of No.2 PCCB should be strengthened in the future.展开更多
The inherent selfishness of each node for the enhancement of message successful delivery ratio and the network overall performance improvement are reflected in the contradiction relationship of competition and coopera...The inherent selfishness of each node for the enhancement of message successful delivery ratio and the network overall performance improvement are reflected in the contradiction relationship of competition and cooperation in delay/disruption tolerant networks (DTN). In particular, the existence of malicious node aggravates this contradiction. To resolve this contradiction, social relationship theory and group theory of social psychology were adopted to do an in-depth analysis. The concrete balancing approach which leveraged Nash equilibrium theory of game theory was proposed to resolve this contradiction in reality. Thus, a new congestion control routing algorithm for security defense based on social psychology and game theory (CRSG) was put forward. Through the experiment, this algorithm proves that it can enhance the message successful delivery ratio by more than 15% and reduce the congestion ratio over 15% as well. This algorithm balances the contradiction relationship between the two key performance targets and made all nodes exhibit strong cooperation relationship in DTN.展开更多
Such an extremely difficult issue as cultural diversity is confronted by the existence and evolution of enterprises with the rapid development of global economy of the present. If the establishment is to boost competi...Such an extremely difficult issue as cultural diversity is confronted by the existence and evolution of enterprises with the rapid development of global economy of the present. If the establishment is to boost competitiveness, it must have a quite good knowledge of target market so as to formulate some efficient strategies of broadcasting in its management, and the best way to resolve such problem is to eliminate cultural barriers with the adoption of the transmission of cross-cultural advertisements. This thesis shall research cultural diversities between eastern nations and western ones, and explore the effect the diversities have upon cross-cultural transmission, thus to propose an approach of eliminating cultural isolation with the adoption of effective techniques and manners of the transmission of cross-cultural advertisements.展开更多
The necessity of adding safetyinformation which is in minority languagesinto standards is discussed.The requirementsof the WTO-TBT agreement and IECare analyzed.The relevant laws and foundationtechnology for minority ...The necessity of adding safetyinformation which is in minority languagesinto standards is discussed.The requirementsof the WTO-TBT agreement and IECare analyzed.The relevant laws and foundationtechnology for minority languages inChina are discussed.The precedents ofstandards or technical regulations are enumerated.The conclusion is put forward thatsafety information in minority languagesshould be added into standards as soon aspossible.展开更多
In this paper, we propose a new lightweight block cipher named RECTANGLE. The main idea of the design of RECTANGLE is to allow lightweight and fast implementations using bit-slice techniques. RECTANGLE uses an SP-netw...In this paper, we propose a new lightweight block cipher named RECTANGLE. The main idea of the design of RECTANGLE is to allow lightweight and fast implementations using bit-slice techniques. RECTANGLE uses an SP-network. The substitution layer consists of 16 4 × 4 S-boxes in parallel. The permutation layer is composed of 3 rotations. As shown in this paper, RECTANGLE offers great performance in both hardware and software environment, which provides enough flexibility for different application scenario. The following are3 main advantages of RECTANGLE. First, RECTANGLE is extremely hardware-friendly. For the 80-bit key version, a one-cycle-per-round parallel implementation only needs 1600 gates for a throughput of 246 Kbits/s at100 k Hz clock and an energy efficiency of 3.0 p J/bit. Second, RECTANGLE achieves a very competitive software speed among the existing lightweight block ciphers due to its bit-slice style. Using 128-bit SSE instructions,a bit-slice implementation of RECTANGLE reaches an average encryption speed of about 3.9 cycles/byte for messages around 3000 bytes. Last but not least, we propose new design criteria for the RECTANGLE S-box.Due to our careful selection of the S-box and the asymmetric design of the permutation layer, RECTANGLE achieves a very good security-performance tradeoff. Our extensive and deep security analysis shows that the highest number of rounds that we can attack, is 18(out of 25).展开更多
In this paper,we present a central cutting plane algorithm for solving convex min-max semi-infinite programming problems.Because the objective function here is non-differentiable,we apply a smoothing technique to the ...In this paper,we present a central cutting plane algorithm for solving convex min-max semi-infinite programming problems.Because the objective function here is non-differentiable,we apply a smoothing technique to the considered problem and develop an algorithm based on the entropy function.It is shown that the global convergence of the proposed algorithm can be obtained under weaker conditions.Some numerical results are presented to show the potential of the proposed algorithm.展开更多
基金supported by the Sino-Probe09(No.201011078)National High-tech R&D Program(No.863 and2014AA06A613)
文摘We apply reweighted inversion focusing to full tensor gravity gradiometry data using message-passing interface (MPI) and compute unified device architecture (CUDA) parallel computing algorithms, and then combine MPI with CUDA to formulate a hybrid algorithm. Parallel computing performance metrics are introduced to analyze and compare the performance of the algorithms. We summarize the rules for the performance evaluation of parallel algorithms. We use model and real data from the Vinton salt dome to test the algorithms. We find good match between model efficiency and feasibility of parallel computing gravity gradiometry data. and real density data, and verify the high algorithms in the inversion of full tensor
基金Project 0424220161 supported by Science and Technology Foundation of Education Bureau of Henan Province
文摘Based on the basic content of advanced technology,safety and reliability, and economic reasonability and the definition of mine ventilation system, 16 assessment indexes of ventilation system are put forward from the point of 8 aspects such as mine ventilation power, ventilation network, ventilation equipments, ventilation quality, ventilation monitoring, capacity of preventing and fighting disaster, ventilation consumption of power, and the capacity of ventila- tion system. A new assessment index system is put forward and has a good effect after being applied in coal mines.
文摘AIM:To prospectively assess the eff icacy and safety of stapled trans-anal rectal resection(STARR) compared to standard conservative treatment,and whether preoperative symptoms and findings at defecography and anorectal manometry can predict the outcome of STARR.METHODS:Thirty patients(Female,28;age:51 ± 9 years) with rectocele or rectal intussusception,a defecation disorder,and functional constipation were submitted for STARR.Thirty comparable patients(Female,30;age 53 ± 13 years),who presented with symptoms of rectocele or rectal intussusception and were treated with macrogol,were assessed.Patients were interviewed with a standardized questionnaire at study enrollment and 38 ± 18 mo after the STARR procedure or during macrogol treatment.A responder was def ined as an absence of the Rome Ⅲ diagnostic criteria for functional constipation.Defecography and rectoanal manometry were performed before and after the STARR procedure in 16 and 12 patients,respectively.RESULTS:After STARR,53% of patients were responders;during conservative treatment,75% were responders.After STARR,30% of the patients reported the use of laxatives,17% had intermittent anal pain,13% had anal leakage,13% required digital facilitation,6% experienced defecatory urgency,6% experienced fecal incontinence,and 6% required re-intervention.During macrogol therapy,23% of the patients complained of abdominal bloating and 13% of borborygmi,and 3% required digital facilitation.No preoperative symptom,defecographic,or manometric finding predicted the outcome of STARR.Post-operative defecography showed a statistically significant reduction(P < 0.05) of the rectal diameter and rectocele.The postoperative anorectal manometry showed that anal pressure and rectal sensitivity were not significantly modified,and that rectal compliance was reduced(P = 0.01).CONCLUSION:STARR is not better and is less safe than macrogol in the treatment of defecation disorders.It could be considered as an alternative therapy in patients unresponsive to macrogol.
文摘AIM:To study the safety and effectiveness of propofol sedation for outpatient colonoscopy.METHODS:Propofol was given by bolus injection with an age-adjusted standard protocol consisting of 60 mg for patients < 70 years old,40 mg for patients age 70-89 years,and 20 mg for those ≥ 90 years,and additional injections of 20 mg propofol were given up to a maximum of 200 mg.The principal parameters were the occurrence of adverse events within 24 h after colonoscopy and overall satisfaction for this procedure.Secondary parameters included successful procedure,respiratory depression,and other complications.RESULTS:Consecutive patients were entered prospectively and all 2101 entered successfully completed outpatient colonoscopy.The mean dose of propofol used was 96.4 mg(range 40-200 mg).Younger patients required higher doses of propofol than older patients(20-40 years vs ≥ 61 years:115.3 ± 32 mg vs 89.7 ± 21 mg,P < 0.001).Transient supplemental oxygen supply was needed by five patients(0.2%);no other complications occurred.The questionnaires were completed by 1820(87%) of 2101 patients and most rated their overall satisfaction as excellent(80%) or good(17%).The majority(65%) of patients drove home or to their office after their colonoscopy.Most(99%) were willing to repeat the same procedure.No incidents occurred within 24 h after colonoscopy.CONCLUSION:Propofol sedation using a dose < 200 mg proved both safe and practical for outpatient colonoscopy.
基金financially supported by the National Natural Science Foundation of China (No. 51134023)
文摘In mine ventilation networks, the reasonable airflow distribution is very important for the production safety and economy. Three basic problems of the natural, full-controlled and semi-controlled splitting were reviewed in the paper. Aiming at the high difficulty semi-controlled splitting problem, the general nonlinear multi-objectives optimization mathematical model with constraints was established based on the theory of mine ventilation networks. A new algorithm, which combined the improved differential evaluation and the critical path method (CPM) based on the multivariable separate solution strategy, was put forward to search for the global optimal solution more efficiently. In each step of evolution, the feasible solutions of air quantity distribution are firstly produced by the improved differential evolu- tion algorithm, and then the optimal solutions of regulator pressure drop are obtained by the CPM. Through finite steps iterations, the optimal solution can be given. In this new algorithm, the population of feasible solutions were sorted and grouped for enhancing the global search ability and the individuals in general group were randomly initialized for keeping diversity. Meanwhile, the individual neighbor- hood in the fine group which may be closely to the optimal solutions were searched locally and slightly for achieving a balance between global searching and local searching, thus improving the convergence rate. The computer program was developed based on this method. Finally, the two ventilation networks with single-fan and multi-fans were solved. The results show that this algorithm has advantages of high effectiveness, fast convergence, good robustness and flexibility. This computer program could be used to solve lar^e-scale ~eneralized ventilation networks o^timization problem in the future.
基金funded by the Science and Technology Project of CNPC Southwest Oil and Gas Field Branch (202,20301-01-03)。
文摘When simulating the propagation of seismic waves in some special structures,such as tunnels and boreholes,finite difference forward modeling in the polar system has higher accuracy than the traditional Cartesian system.In actual situations,the polar space is the most irregular.To solve this problem,a forward modeling method for an irregular polar coordinate system is proposed to improve the simulation accuracy.First,an irregular surface of the polar space was meshed into an irregular polar system.After the transformation,the undulating surface was mapped into a plane one,and the wavefield was then computed in an irregular polar system.The Lebedev staggered grid was used to solve the wave equations in the irregular polar system.In addition,the artificial absorption boundary,cylindrical free boundary,and circumferential boundary conditions were used to absorb the boundary reflection.We selected three polar space models to demonstrate the new method in this study.The results show that the proposed elastic simulation method in an irregular polar coordinate system can produce more accurate and stable simulation results when modeling seismic wave propagation in an irregular polar space.Elastic full waveform inversion further shows that the irregular polar system elastic simulation method can accurately simulate the wavefield in an undulating polar space.
文摘A mine ventilation system has a deterministic function for the safety of coal production and for the control of mine accidents. So, it has an important meaning to evaluate the security of a mine ventilation system. This paper studied the evaluation index system of the security of a mine ventilation system, and the security of a mine ventilation system was described quantitatively in the safety degree. Finally, an example of the security evaluation was given.
基金Project(2010B14814) supported by the Fundamental Research Funds for the Central Universities of ChinaProject(200801133) supported by the Ministry of Water Resources of China for Public Welfare ProfessionProject(50809023) supported by the National Natural Science Foundation of China
文摘Based on Mohr-Coulomb (M-C) criterion, the parameters of Druker-Prager (D-P) criterion for geomaterial were determined under non-associated flow rule, and thus a new D-P type criterion was presented. Two assumptions were employed during the derivation: 1) principal strains by M-C model and D-P model are equal, and 2) the material is under plane strain condition. Based on the analysis of the surface on rt plane, it is found that the proposed D-P type criterion is better than the D-P criterion with M-C circumscribed circle or M-C inscribed circle, and is applicable for stress Lode angle less than zero. By comparing the predicted results with the test data of sand under plane strain condition and other D-P criteria, the proposed criterion is verified and agrees well with the test data, which is further proved to be better than other D--P type criteria in certain range of Lode angle. The criterion was compiled into a finite difference package FLAC3D by user-subroutine, and was used to analyze the stability of a slope by strength reduction method. The predicted slope safety factor from the proposed criterion agrees well with that by Spencer method, and it is more accurate than that from classic D-P criteria.
基金Supported by the Natural Science Foundation of Jiangxi , China (No.0511006)
文摘The chromatically uniqueness of bipartite graphs K (m, n) - A(]A] = 2) was studied. With comparing the numbers of partitions into r color classes of two chromatically equivalent graphs, one general numerical condition guaranteeing that K( m, n) - A ( I A ] = 2) is chromatically unique were obtained. This covers and improves the former correlative results.
文摘The safety status of the coal mines is closely correlated with the operating status and its changes of the whole working system in the coal mines, and the safety system is the sub system of the whole production system. In this paper, based on the analysis of the complicacy of the safety sub system and its affecting factors, the theory basis of the indexes system of the safety assessment was studied, including the establishing principles of the indexes system , the structure of the indexes system, the determining methods of the assessment indexes. The complete indexes system was established for the safety assessment of the coal mines in the paper.
文摘The basic element in any sustainable dam project is safety, which includes the following safety elements: O structural safety, dam safety monitoring, operational safety and maintenance, and emergency planning. Long-term safety primarily includes the analysis of all hazards affecting the project; that is, hazards from the natural environment, hazards from the man-made environment, and project-specific and site-specific hazards. The special features of the seismic safety of dams are discussed. Large dams were the first structures to be systematically designed against earthquakes, starting in the 1930s. How- ever, the seismic safety of older dams is unknown, as most were designed using seismic design criteria and methods of dynamic analysis that are considered obsolete today. Therefore, we need to reevaluate the seismic safety of existing dams based on current state-of-the-art practices and rehabilitate deficient dams. For large dams, a site-specific seismic hazard analysis is usually recommended. Today, large dams and the safety-relevant elements used for controlling the reservoir after a strong earthquake must be able to withstand the ground motions of a safety evaluation earthquake. The ground motion parameters can be determined either by a probabilistic or a deterministic seismic hazard analysis. During strong earthquakes, inelastic deformations may occur in a dam; therefore, the seismic analysis has to be car- ried out in the time domain. Furthermore, earthquakes create multiple seismic hazards for dams such as ground shaking, fault movements, mass movements, and others. The ground motions needed by the dam engineer are not real earthquake ground motions but models of the ground motion, which allow the safe design of dams. It must also be kept in mind that darn safety evaluations must be carried out several times during the long life of large storage dams. These features are discussed in this paper.
基金supported by the Shandong Seed Project and the National Natural Science Foundation of China (31372524)
文摘Linkage disequilibrium(LD) can be applied for mapping the actual genes responsible for variation of economically important traits through association mapping.The feasibility and efficacy of association studies are strongly dependent on the extent of LD which determines the number and density of markers in the studied population,as well as the experimental design for an association analysis.In this study,we first characterized the extent of LD in a wild population and a cultured mass-selected line of Pacific oyster(Crassostrea gigas).A total of 88 wild and 96 cultured individuals were selected to assess the level of genome-wide LD with 53 microsatellites,respectively.For syntenic marker pairs,no significant association was observed in the wild population;however,three significant associations occurred in the cultured population,and the significant LD extended up to 12.7 c M,indicating that strong artificial selection is a key force for substantial increase of genome-wide LD in cultured population.The difference of LD between wild and cultured populations showed that association studies in Pacific oyster can be achieved with reasonable marker densities at a relatively low cost by choosing an association mapping population.Furthermore,the frequent occurrence of LD between non-syntenic loci and rare alleles encourages the joint application of linkage analysis and LD mapping when mapping genes in oyster.The information on the linkage disequilibrium in the cultured population is useful for future association mapping in oyster.
文摘Due to the limited amount of funds available for bridge inspection, maintenance and rehabilitation, the evaluation of load capacity for existing bridges is crucial to the Louisiana Department of Transportation and Development. This paper includes the development of a methodology to assess the economic impact of overweight vehicles with permits, hauling Louisiana harvest products on state bridges. The proposed higher truck loads are applied on the existing bridges and their effects are determined using deterministic load capacity evaluations as well as reliability assessments. The target rehability level is derived from bridge structures designed to satisfy AASHTO Standard Design Specifications and also satisfy safe and adequate performance levels. The amount of harvest produced is used to select a representative sample of bridges to provide specific examples of expected changes in load ratings and safety levels. The bridges include simple and continuous span behavior. Strength and serviceability criteria are investigated under current legal loads and the expected changes, due to the proposed new weights, are determined. The results are used to assess the cost of crossing a bridge and the permit fees for the proposed truck weight regulation.
基金Project(20050487017) supported by the Specialized Research Fund for the Doctoral Program of Higher Education of ChinaProject (2009567) supported by China National Nuclear Corporation
文摘The permeability and sorptivity properties of the two prestressed concrete containment buildings (PCCBs) of a nuclear power plant in South China, which had been under operation for 5 years, were measured by using the autoclam permeability system. The air permeability, sorptivity and water permeability indexes of No.1 PCCB are smaller than or equal to 0.11 ln(102 Pa)/min, 0.98×10 ^7 m3/minl/2 and 1.93×10 ^7 m3/min1/2, respectively, and the air permeability, sorptivity and water permeability indexes of No.2 PCCB are smaller than or equal to 0.17 In(102 Pa)/min, 1.6×10 ^7 m3/min1/2 and 4.43 ×10 ^7 m3/min1/2, respectively. Based on the criteria for evaluating the protective quality of concrete structures in terms of their permeability and sorptivity properties, proposed by the research organization of the autoclam permeability system, the protective quality of No. 1 PCCB is still in very good grade and that of No.2 PCCB is not in very good grade but in good grade, and the in-service inspection of the protective quality of No.2 PCCB should be strengthened in the future.
基金Projects(61202488, 61070199, 61103182) supported by the National Natural Science Foundation of China
文摘The inherent selfishness of each node for the enhancement of message successful delivery ratio and the network overall performance improvement are reflected in the contradiction relationship of competition and cooperation in delay/disruption tolerant networks (DTN). In particular, the existence of malicious node aggravates this contradiction. To resolve this contradiction, social relationship theory and group theory of social psychology were adopted to do an in-depth analysis. The concrete balancing approach which leveraged Nash equilibrium theory of game theory was proposed to resolve this contradiction in reality. Thus, a new congestion control routing algorithm for security defense based on social psychology and game theory (CRSG) was put forward. Through the experiment, this algorithm proves that it can enhance the message successful delivery ratio by more than 15% and reduce the congestion ratio over 15% as well. This algorithm balances the contradiction relationship between the two key performance targets and made all nodes exhibit strong cooperation relationship in DTN.
文摘Such an extremely difficult issue as cultural diversity is confronted by the existence and evolution of enterprises with the rapid development of global economy of the present. If the establishment is to boost competitiveness, it must have a quite good knowledge of target market so as to formulate some efficient strategies of broadcasting in its management, and the best way to resolve such problem is to eliminate cultural barriers with the adoption of the transmission of cross-cultural advertisements. This thesis shall research cultural diversities between eastern nations and western ones, and explore the effect the diversities have upon cross-cultural transmission, thus to propose an approach of eliminating cultural isolation with the adoption of effective techniques and manners of the transmission of cross-cultural advertisements.
文摘The necessity of adding safetyinformation which is in minority languagesinto standards is discussed.The requirementsof the WTO-TBT agreement and IECare analyzed.The relevant laws and foundationtechnology for minority languages inChina are discussed.The precedents ofstandards or technical regulations are enumerated.The conclusion is put forward thatsafety information in minority languagesshould be added into standards as soon aspossible.
基金supported by National Natural Science Foundation of China(Grant No.61379138)Research Fund KU Leuven(OT/13/071)+1 种基金"Strategic Priority Research Program"of the Chinese Academy of Sciences(Grant No.XDA06010701)National High-tech R&D Program of China(863 Program)(Grant No.2013AA014002)
文摘In this paper, we propose a new lightweight block cipher named RECTANGLE. The main idea of the design of RECTANGLE is to allow lightweight and fast implementations using bit-slice techniques. RECTANGLE uses an SP-network. The substitution layer consists of 16 4 × 4 S-boxes in parallel. The permutation layer is composed of 3 rotations. As shown in this paper, RECTANGLE offers great performance in both hardware and software environment, which provides enough flexibility for different application scenario. The following are3 main advantages of RECTANGLE. First, RECTANGLE is extremely hardware-friendly. For the 80-bit key version, a one-cycle-per-round parallel implementation only needs 1600 gates for a throughput of 246 Kbits/s at100 k Hz clock and an energy efficiency of 3.0 p J/bit. Second, RECTANGLE achieves a very competitive software speed among the existing lightweight block ciphers due to its bit-slice style. Using 128-bit SSE instructions,a bit-slice implementation of RECTANGLE reaches an average encryption speed of about 3.9 cycles/byte for messages around 3000 bytes. Last but not least, we propose new design criteria for the RECTANGLE S-box.Due to our careful selection of the S-box and the asymmetric design of the permutation layer, RECTANGLE achieves a very good security-performance tradeoff. Our extensive and deep security analysis shows that the highest number of rounds that we can attack, is 18(out of 25).
基金supported by National Natural Science Foundation of China(Grant No.11271221)
文摘In this paper,we present a central cutting plane algorithm for solving convex min-max semi-infinite programming problems.Because the objective function here is non-differentiable,we apply a smoothing technique to the considered problem and develop an algorithm based on the entropy function.It is shown that the global convergence of the proposed algorithm can be obtained under weaker conditions.Some numerical results are presented to show the potential of the proposed algorithm.