This commentary is intended to take China as a case to discuss the mission of the family planning program under low fertility scenario.After a brief review of the initiation of family planning program in the 1970s,as ...This commentary is intended to take China as a case to discuss the mission of the family planning program under low fertility scenario.After a brief review of the initiation of family planning program in the 1970s,as well as the reorientation of family planning program since ICPD in 1994,it will focus on the new mission for the family planning program under low fertility scenario in the twenty-first century,in particular concerning the issue of induced abortion among the others.Given the enormous evidence of unmet needs in reproductive health as identified in the discussion,it is argued that family planning programmes are in fact even more needed than ever before under low-fertility scenario,and should not be abandoned but strengthened,which clearly has nothing to do to call back to the program for population control in the 1970s-1980s,and nor even go back to the program for“two reorientations”in the 1990s,but to aim to serving the people to fulfill their reproductive health and reproductive rights in light of ICPD and SDGs,and to become truly integral component of“Healthy China 2030”Strategy.展开更多
At the first sight it seems that advanced operation research is not used enough in continuous production systems as comparison with mass production, batch production and job shop systems, but really in a comprehensive...At the first sight it seems that advanced operation research is not used enough in continuous production systems as comparison with mass production, batch production and job shop systems, but really in a comprehensive evaluation the advanced operation research techniques can be used in continuous production systems in developing countries very widely, because of initial inadequate plant layout, stage by stage development of production lines, the purchase of second hand machineries from various countries, plurality of customers. A case of production system planning is proposed for a chemical company in which the above mentioned conditions are almost presented. The goals and constraints in this issue are as follows: (1) Minimizing deviation of customer's requirements. (2) Maximizing the profit. (3) Minimizing the frequencies of changes in formula production. (4) Minimizing the inventory of final products. (5) Balancing the production sections with regard to rate in production. (6) Limitation in inventory of raw material. The present situation is in such a way that various techniques such as goal programming, linear programming and dynamic programming can be used. But dynamic production programming issues are divided into two categories, at first one with limitation in production capacity and another with unlimited production capacity. For the first category, a systematic and acceptable solution has not been presented yet. Therefore an innovative method is used to convert the dynamic situation to a zero- one model. At last this issue is changed to a goal programming model with non-linear limitations with the use of GRG algorithm and that's how it is solved.展开更多
For low-speed underwater vehicles, the ocean currents has a great influence on them, and the changes in ocean currents is complex and continuous, thus whose impact must be taken into consideration in the path planning...For low-speed underwater vehicles, the ocean currents has a great influence on them, and the changes in ocean currents is complex and continuous, thus whose impact must be taken into consideration in the path planning. There are still lack of authoritative indicator and method for the cooperating path planning. The calculation of the voyage time is a difficult problem in the time-varying ocean, for the existing methods of the cooperating path planning, the computation time will increase exponentially as the autonomous underwater vehicle(AUV) counts increase, rendering them unfeasible. A collaborative path planning method is presehted for multi-AUV under the influence of time-varying ocean currents based on the dynamic programming algorithm. Each AUV cooperates with the one who has the longest estimated time of sailing, enabling the arrays of AUV to get their common goal in the shortest time with minimum timedifference. At the same time, they could avoid the obstacles along the way to the target. Simulation results show that the proposed method has a promising applicability.展开更多
This paper attempts to optimize optimal capacities, block routing and mine sequencing problems in a mining system. The solution approach is based on a heuristics and the mixed integer programming (MIP). Unlike previou...This paper attempts to optimize optimal capacities, block routing and mine sequencing problems in a mining system. The solution approach is based on a heuristics and the mixed integer programming (MIP). Unlike previous sequential solution approaches, the problems are herein solved at the same time. Furthermore, the proposed approach guarantees practical solutions because it considers ore material distribution within orebody. The paper has two main contributions: (a) the proposed approach generates production rates in a manner that the capacities are satisfied; (b) the proposed approach does not use pre-defined marginal cut-off grades. Thus, idle capacity problem is eliminated and different scheduling combinations are allowed. To see the performance of the approach proposed, a case study is carried out using a gold data. The schedule generated shows that the approach can determine optimal production rates, block destination and sequencing effectively.展开更多
With diversified requirements and varying manufacturing environments, the optimal production planning for a steel mill becomes more flexible and complicated. The flexibility provides operators with auxiliary requireme...With diversified requirements and varying manufacturing environments, the optimal production planning for a steel mill becomes more flexible and complicated. The flexibility provides operators with auxiliary requirements through an implementable integrated production planning. In this paper, a mixed-integer nonlinear programming(MINLP) model is proposed for the optimal planning that incorporates various manufacturing constraints and flexibility in a steel plate mill. Furthermore, two solution strategies are developed to overcome the weakness in solving the MINLP problem directly. The first one is to transform the original MINLP formulation to an approximate mixed integer linear programming using a classic linearization method. The second one is to decompose the original model using a branch-and-bound based iterative method. Computational experiments on various instances are presented in terms of the effectiveness and applicability. The result shows that the second method performs better in computational efforts and solution accuracy.展开更多
The primary focus of this paper is to design a progressive restoration plan for an enterprise data center environment following a partial or full disruption. Repairing and restoring disrupted components in an enterpri...The primary focus of this paper is to design a progressive restoration plan for an enterprise data center environment following a partial or full disruption. Repairing and restoring disrupted components in an enterprise data center requires a significant amount of time and human effort. Following a major disruption, the recovery process involves multiple stages, and during each stage, the partially recovered infrastructures can provide limited services to users at some degraded service level. However, how fast and efficiently an enterprise infrastructure can be recovered de- pends on how the recovery mechanism restores the disrupted components, considering the inter-dependencies between services, along with the limitations of expert human operators. The entire problem turns out to be NP- hard and rather complex, and we devise an efficient meta-heuristic to solve the problem. By considering some real-world examples, we show that the proposed meta-heuristic provides very accurate results, and still runs 600-2800 times faster than the optimal solution obtained from a general purpose mathematical solver [1].展开更多
Modern biotechnology booms in the molecular life science. It brings about a promising future for improving human health, foodstuff, environment and energy and is of significance to improve traditional agriculture, dru...Modern biotechnology booms in the molecular life science. It brings about a promising future for improving human health, foodstuff, environment and energy and is of significance to improve traditional agriculture, druamakins and other展开更多
OBJECTIVE: A meta-analysis of published randomized controlled trials investigating the long- term effect of dexamethasone on the nervous system of preterm infants. DATA SOURCES: Online literature retrieval was condu...OBJECTIVE: A meta-analysis of published randomized controlled trials investigating the long- term effect of dexamethasone on the nervous system of preterm infants. DATA SOURCES: Online literature retrieval was conducted using The Cochrane Library (from January 1993 to June 2013), EMBASE (from January 1980 to June 2013), MEDLINE (from Janu- ary 1963 to June 2013), OVID (from January 1993 to June 2013), Springer (from January 1994 to June 2013) and Chinese Academic Journal Full-text Database (from January 1994 to June 2013). Key words were preterm infants and dexamethasone in English and Chinese. STUDY SELECTION: Selected studies were randomized controlled trials assessing the effect of intravenous dexamethasone in preterm infants. The quality of the included papers was evaluated and those without the development of the nervous system and animal experiments were exclud- ed. Quality assessment was performed through bias risk evaluation in accordance with Cochrane Handbook 5.1.0 software in the Cochrane Collaboration. The homogeneous studies were analyzed and compared using Revman 5.2.6 software, and then effect model was selected and analyzed. Those papers failed to be included in the meta-analysis were subjected to descriptive analysis. MAIN OUTCOME MEASURES: Nervous system injury in preterm infants. RESULTS: Ten randomized controlled trials were screened, involving 1,038 subjects. Among them 512 cases received dexamethasone treatment while 526 cases served as placebo control group and blank control group. Meta-analysis results showed that the incidence of cerebral palsy, visual im- pairment and hearing loss in preterm infants after dexamethasone treatment within 7 days after birth was similar to that in the control group (RR = 1.47, 95%CI: 0.97-2.21; RR = 1.46, 95%CI: 0.97-2.20; RR = 0.80, 95%CI: 0.54-1.18; P 〉 0.05), but intelligence quotient was significantly de- creased compared with the control group (MD = -3.55, 95%CI: -6.59 to -0.51; P = 0.02). Prete rm infants treated with dexamethasone 7 days after birth demonstrated an incidence of cerebral palsy and visual impairment, and changes in intelligence quotient similar to those in the control group (RR = 1.26, 95%CI: 0.89-1.79; RR = 1.37, 95%CI: 0.73-2.59; RR = 0.53, 95%CI: 0.32-0.89; RR = 1.66, 95%CI: -4.7 to 8.01; P 〉 0.05). However, the incidence of hearing loss was significantly increased compared with that in the control group (RR = 0.53, 95%CI: 0.32-0.89; P = 0.02). CONCLUSION: Dexamethasone may affect the intelligence of preterm infants in the early stages after birth, but may lead to hearing impairment at later stages after birth. More reliable conclusions should be made through large-size, multi-center, well-designed randomized controlled trials.展开更多
Optimization of long-term mine production scheduling in open pit mines deals with the management of cash flows, typically in the order of hundreds of millions of dollars. Conventional mine scheduling utilizes optimiza...Optimization of long-term mine production scheduling in open pit mines deals with the management of cash flows, typically in the order of hundreds of millions of dollars. Conventional mine scheduling utilizes optimization methods that are not capable of accounting for inherent technical uncertainties such as uncertainty in the expected ore/metal supply from the underground, acknowledged to be the most critical factor. To integrate ore/metal uncertainty into the optimization of mine production scheduling a stochastic integer programming(SIP) formulation is tested at a copper deposit. The stochastic solution maximizes the economic value of a project and minimizes deviations from production targets in the presence of ore/metal uncertainty. Unlike the conventional approach, the SIP model accounts and manages risk in ore supply, leading to a mine production schedule with a 29% higher net present value than the schedule obtained from the conventional, industry-standard optimization approach, thus contributing to improving the management and sustainable utilization of mineral resources.展开更多
Planning and production optimization within multiple mines or several work sites (entities) mining systems by using fuzzy linear programming (LP) was studied. LP is the most commonly used operations research metho...Planning and production optimization within multiple mines or several work sites (entities) mining systems by using fuzzy linear programming (LP) was studied. LP is the most commonly used operations research methods in mining engineering. After the introductory review of properties and limitations of applying LP, short reviews of the general settings of deterministic and fuzzy LP models are presented. With the purpose of comparative analysis, the application of both LP models is presented using the example of the Bauxite Basin Niksic with five mines. After the assessment, LP is an efficient mathematical modeling tool in production planning and solving many other single-criteria optimization problems of mining engineering. After the comparison of advantages and deficiencies of both deterministic and fuzzy LP models, the conclusion presents benefits of the fuzzy LP model but is also stating that seeking the optimal plan of production means to accomplish the overall analysis that will encompass the LP model approaches.展开更多
Objective: to assess the evolution of serum creatinine in patients undergoing radical nephrectomy (malignant) or total (benign), to identify risk factors connected with an unfavorable renal function outcome. Material ...Objective: to assess the evolution of serum creatinine in patients undergoing radical nephrectomy (malignant) or total (benign), to identify risk factors connected with an unfavorable renal function outcome. Material and Methods: observational, transversal and retrospective study, through analysis of records and lab exams of 146 patients undergoing nephrectomy from January 2015 to December 2018. Results: Statistically significant difference was found between etiology and patients’ age (p-value Conclusion: This study shows that a large number of young patients undergo nephrectomy, many times avoidable;within a benign disease context with an increased risk of developing renal failure. Greater attention from the public service is required to tackle such chronic condition and its complications.展开更多
Built-up area(BUA)significantly contributes to global greenhouse gas emissions,making strategic spatial planning crucial for carbon emission control.Given the diverse land use patterns and carbon emission sources in B...Built-up area(BUA)significantly contributes to global greenhouse gas emissions,making strategic spatial planning crucial for carbon emission control.Given the diverse land use patterns and carbon emission sources in BUAs,this study proposed a land-based strategy system for carbon emission assessment and optimization.A three-step method was devised to create a planner-friendly tool for implementing the system,which involves carbon emission intensity calculation based on current land use,spatial illustration of carbon emission intensities based on land use planning,and planning program optimization and emission reduction effect assessment.The method was applied to the central urban area of Changxing County(Zhejiang)in China.The results showed that the structures and emission intensities of urban land use substantially influenced the overall carbon emissions in the central urban area.Our comprehensive land use optimization strategies reduced the overall carbon emissions of the central urban area by 36.9%when compared to the original planning program.The Monte Carlo simulation indicated that land use structure optimization and emission intensity control measures could reduce carbon emission rate by 5.20%to 18.28%,and 18.44%to 31.67%,respectively.The results underlined the importance of making specific adjustments to land use structure and implementing intensity control measures for effective carbon reduction.In conclusion,this study offers methods and insights for urban planners in creating sustainable and low-carbon urban spaces.展开更多
The year 2018 marks the 40th anniversary of China’s reforms and opening to the world.As an important part of the overall reform effort,reform of the national family planning program,begun in the 1990s as a pilot proj...The year 2018 marks the 40th anniversary of China’s reforms and opening to the world.As an important part of the overall reform effort,reform of the national family planning program,begun in the 1990s as a pilot project focused on quality of care,has achieved historic and significant results.The pilot project,conducted by the State Family Planning Commission of China in a few select areas,was a response to the 1994 International Conference on Population and Development in Cairo,as well as to a range of social and economic changes in China.To achieve quality of care,the pilot project adopted a client-centered approach to refocus China’s family planning efforts on client needs and rights,informed choice of contraceptives and the provision of better quality services.After nearly 10 years of trials,the successful experiences of the pilot project served as the basis of a family planning program reform rolled out nationwide.This paper uses a logic framework approach to review the main activities,outputs,and impacts of the pilot project.The paper argues that the quality of care project not only developed a model that facilitated reorientation of China’s earlier family planning efforts,but has also provided experiences and lessons that can serve as references for the implementation of“Healthy China 2030”in the future.展开更多
China's Ministry of Science and Technology recently announced approval of China's National Basic Research Program (the 973 Program) and the Major Research Plan projects in 2008. Five Tsinghua research projects wil...China's Ministry of Science and Technology recently announced approval of China's National Basic Research Program (the 973 Program) and the Major Research Plan projects in 2008. Five Tsinghua research projects will be sponsored by the 973 Program and two by the Major Research Plan. Seven professors were appointed as chief scientists for the projects. Tsinghua has undertaken 28 projects since the 973 Program's inception involving 28 chief scientists and eight Major Research Plan projects involving eight chief scientists. Tsinghua is one of the country's leading institutions for supervision and conduct of the 973 Program projects.展开更多
In 2016 China began implementing a new population strategy after having maintained a one-child policy for 35 years.This paper draws on the lessons we can learn about low fertility and population aging in Japan and Sou...In 2016 China began implementing a new population strategy after having maintained a one-child policy for 35 years.This paper draws on the lessons we can learn about low fertility and population aging in Japan and South Korea to consider the implications of the newly announced'universal two-child'policy in China.Japan,Korea and China share many socio-cultural characteristics and have undergone similar processes with respect to low fertility and population aging at different periods of time.Many scholars argue that China's family planning program has greatly reduced China's fertility level,but the effects of other socioeconomic factors have,in fact,had a greater impact on the reduction of the fertility rate than the one-child policy had.Considering the effects of the fertility policy that limits the number of births in China and the lessons we can get from unsuccessful fertility boosting measures in Japan and Korea,this paper suggests that a fertility policy that puts no limits on births should be adopted in China.展开更多
Objective To calculate unmet need for contraception according to revised definition, mapping the contraception service needs and analyze factors related to the unmet need for contraception in Nusa Tenggara Barat (NTB...Objective To calculate unmet need for contraception according to revised definition, mapping the contraception service needs and analyze factors related to the unmet need for contraception in Nusa Tenggara Barat (NTB). Methods This research design was cross sectional, using data from Indonesia Demographic and Health Survey 2012. Subjects were from 1 362 household, and were married women aged 15-49 years in NTB Province (685 women). Calculating method of unmet need for contraception used revised version, and analysis method was univariate, bivariate, and multivariate (Logistic regression). Results Majority of married women aged 15-49 years in NTB need contraception service (73.1%). However, it was known that met need for contraception was only 56.0%. Meanwhile, unmet need rate for contraception in NTB was 17.1%, specifically 11.5% for spacing and 5.6% for limiting. Factors contributing to unmet need for contraception in NTB were: household assets at above average (OR=O. 77), parity of 2-3 children (OR=0. 73), women with junior high school education level (0R=0.68), never be visited by health workers (OR=O. 68). Conclusions Factors that contribute to unmet need for contraception in NTB are household assets, parity, education level and visited by health workers. Government has to prioritize those f our factors in policy intervention and promotion of family planning participation program in NTB.展开更多
文摘This commentary is intended to take China as a case to discuss the mission of the family planning program under low fertility scenario.After a brief review of the initiation of family planning program in the 1970s,as well as the reorientation of family planning program since ICPD in 1994,it will focus on the new mission for the family planning program under low fertility scenario in the twenty-first century,in particular concerning the issue of induced abortion among the others.Given the enormous evidence of unmet needs in reproductive health as identified in the discussion,it is argued that family planning programmes are in fact even more needed than ever before under low-fertility scenario,and should not be abandoned but strengthened,which clearly has nothing to do to call back to the program for population control in the 1970s-1980s,and nor even go back to the program for“two reorientations”in the 1990s,but to aim to serving the people to fulfill their reproductive health and reproductive rights in light of ICPD and SDGs,and to become truly integral component of“Healthy China 2030”Strategy.
文摘At the first sight it seems that advanced operation research is not used enough in continuous production systems as comparison with mass production, batch production and job shop systems, but really in a comprehensive evaluation the advanced operation research techniques can be used in continuous production systems in developing countries very widely, because of initial inadequate plant layout, stage by stage development of production lines, the purchase of second hand machineries from various countries, plurality of customers. A case of production system planning is proposed for a chemical company in which the above mentioned conditions are almost presented. The goals and constraints in this issue are as follows: (1) Minimizing deviation of customer's requirements. (2) Maximizing the profit. (3) Minimizing the frequencies of changes in formula production. (4) Minimizing the inventory of final products. (5) Balancing the production sections with regard to rate in production. (6) Limitation in inventory of raw material. The present situation is in such a way that various techniques such as goal programming, linear programming and dynamic programming can be used. But dynamic production programming issues are divided into two categories, at first one with limitation in production capacity and another with unlimited production capacity. For the first category, a systematic and acceptable solution has not been presented yet. Therefore an innovative method is used to convert the dynamic situation to a zero- one model. At last this issue is changed to a goal programming model with non-linear limitations with the use of GRG algorithm and that's how it is solved.
基金supported by the National Natural Science Foundation of China(5110917951179156+2 种基金5137917661473233)the Natural Science Basic Research Plan in Shaanxi Province of China(2014JQ8330)
文摘For low-speed underwater vehicles, the ocean currents has a great influence on them, and the changes in ocean currents is complex and continuous, thus whose impact must be taken into consideration in the path planning. There are still lack of authoritative indicator and method for the cooperating path planning. The calculation of the voyage time is a difficult problem in the time-varying ocean, for the existing methods of the cooperating path planning, the computation time will increase exponentially as the autonomous underwater vehicle(AUV) counts increase, rendering them unfeasible. A collaborative path planning method is presehted for multi-AUV under the influence of time-varying ocean currents based on the dynamic programming algorithm. Each AUV cooperates with the one who has the longest estimated time of sailing, enabling the arrays of AUV to get their common goal in the shortest time with minimum timedifference. At the same time, they could avoid the obstacles along the way to the target. Simulation results show that the proposed method has a promising applicability.
文摘This paper attempts to optimize optimal capacities, block routing and mine sequencing problems in a mining system. The solution approach is based on a heuristics and the mixed integer programming (MIP). Unlike previous sequential solution approaches, the problems are herein solved at the same time. Furthermore, the proposed approach guarantees practical solutions because it considers ore material distribution within orebody. The paper has two main contributions: (a) the proposed approach generates production rates in a manner that the capacities are satisfied; (b) the proposed approach does not use pre-defined marginal cut-off grades. Thus, idle capacity problem is eliminated and different scheduling combinations are allowed. To see the performance of the approach proposed, a case study is carried out using a gold data. The schedule generated shows that the approach can determine optimal production rates, block destination and sequencing effectively.
基金Supported in part by the National High Technology Research and Development Program of China(2012AA041701)the National Natural Science Foundation of China(61320106009) the 111 Project of China(B07031)
文摘With diversified requirements and varying manufacturing environments, the optimal production planning for a steel mill becomes more flexible and complicated. The flexibility provides operators with auxiliary requirements through an implementable integrated production planning. In this paper, a mixed-integer nonlinear programming(MINLP) model is proposed for the optimal planning that incorporates various manufacturing constraints and flexibility in a steel plate mill. Furthermore, two solution strategies are developed to overcome the weakness in solving the MINLP problem directly. The first one is to transform the original MINLP formulation to an approximate mixed integer linear programming using a classic linearization method. The second one is to decompose the original model using a branch-and-bound based iterative method. Computational experiments on various instances are presented in terms of the effectiveness and applicability. The result shows that the second method performs better in computational efforts and solution accuracy.
文摘The primary focus of this paper is to design a progressive restoration plan for an enterprise data center environment following a partial or full disruption. Repairing and restoring disrupted components in an enterprise data center requires a significant amount of time and human effort. Following a major disruption, the recovery process involves multiple stages, and during each stage, the partially recovered infrastructures can provide limited services to users at some degraded service level. However, how fast and efficiently an enterprise infrastructure can be recovered de- pends on how the recovery mechanism restores the disrupted components, considering the inter-dependencies between services, along with the limitations of expert human operators. The entire problem turns out to be NP- hard and rather complex, and we devise an efficient meta-heuristic to solve the problem. By considering some real-world examples, we show that the proposed meta-heuristic provides very accurate results, and still runs 600-2800 times faster than the optimal solution obtained from a general purpose mathematical solver [1].
文摘Modern biotechnology booms in the molecular life science. It brings about a promising future for improving human health, foodstuff, environment and energy and is of significance to improve traditional agriculture, druamakins and other
基金supported by the Science and Technology Plan Program of Hunan Province,No.2011SK3234
文摘OBJECTIVE: A meta-analysis of published randomized controlled trials investigating the long- term effect of dexamethasone on the nervous system of preterm infants. DATA SOURCES: Online literature retrieval was conducted using The Cochrane Library (from January 1993 to June 2013), EMBASE (from January 1980 to June 2013), MEDLINE (from Janu- ary 1963 to June 2013), OVID (from January 1993 to June 2013), Springer (from January 1994 to June 2013) and Chinese Academic Journal Full-text Database (from January 1994 to June 2013). Key words were preterm infants and dexamethasone in English and Chinese. STUDY SELECTION: Selected studies were randomized controlled trials assessing the effect of intravenous dexamethasone in preterm infants. The quality of the included papers was evaluated and those without the development of the nervous system and animal experiments were exclud- ed. Quality assessment was performed through bias risk evaluation in accordance with Cochrane Handbook 5.1.0 software in the Cochrane Collaboration. The homogeneous studies were analyzed and compared using Revman 5.2.6 software, and then effect model was selected and analyzed. Those papers failed to be included in the meta-analysis were subjected to descriptive analysis. MAIN OUTCOME MEASURES: Nervous system injury in preterm infants. RESULTS: Ten randomized controlled trials were screened, involving 1,038 subjects. Among them 512 cases received dexamethasone treatment while 526 cases served as placebo control group and blank control group. Meta-analysis results showed that the incidence of cerebral palsy, visual im- pairment and hearing loss in preterm infants after dexamethasone treatment within 7 days after birth was similar to that in the control group (RR = 1.47, 95%CI: 0.97-2.21; RR = 1.46, 95%CI: 0.97-2.20; RR = 0.80, 95%CI: 0.54-1.18; P 〉 0.05), but intelligence quotient was significantly de- creased compared with the control group (MD = -3.55, 95%CI: -6.59 to -0.51; P = 0.02). Prete rm infants treated with dexamethasone 7 days after birth demonstrated an incidence of cerebral palsy and visual impairment, and changes in intelligence quotient similar to those in the control group (RR = 1.26, 95%CI: 0.89-1.79; RR = 1.37, 95%CI: 0.73-2.59; RR = 0.53, 95%CI: 0.32-0.89; RR = 1.66, 95%CI: -4.7 to 8.01; P 〉 0.05). However, the incidence of hearing loss was significantly increased compared with that in the control group (RR = 0.53, 95%CI: 0.32-0.89; P = 0.02). CONCLUSION: Dexamethasone may affect the intelligence of preterm infants in the early stages after birth, but may lead to hearing impairment at later stages after birth. More reliable conclusions should be made through large-size, multi-center, well-designed randomized controlled trials.
基金funded from the National Science and Engineering Research Council of Canada,Collaborative R&D Grant CRDPJ 335696 with BHP Billiton and NSERC Discovery Grant 239019 to R. Dimitrakopoulos
文摘Optimization of long-term mine production scheduling in open pit mines deals with the management of cash flows, typically in the order of hundreds of millions of dollars. Conventional mine scheduling utilizes optimization methods that are not capable of accounting for inherent technical uncertainties such as uncertainty in the expected ore/metal supply from the underground, acknowledged to be the most critical factor. To integrate ore/metal uncertainty into the optimization of mine production scheduling a stochastic integer programming(SIP) formulation is tested at a copper deposit. The stochastic solution maximizes the economic value of a project and minimizes deviations from production targets in the presence of ore/metal uncertainty. Unlike the conventional approach, the SIP model accounts and manages risk in ore supply, leading to a mine production schedule with a 29% higher net present value than the schedule obtained from the conventional, industry-standard optimization approach, thus contributing to improving the management and sustainable utilization of mineral resources.
文摘Planning and production optimization within multiple mines or several work sites (entities) mining systems by using fuzzy linear programming (LP) was studied. LP is the most commonly used operations research methods in mining engineering. After the introductory review of properties and limitations of applying LP, short reviews of the general settings of deterministic and fuzzy LP models are presented. With the purpose of comparative analysis, the application of both LP models is presented using the example of the Bauxite Basin Niksic with five mines. After the assessment, LP is an efficient mathematical modeling tool in production planning and solving many other single-criteria optimization problems of mining engineering. After the comparison of advantages and deficiencies of both deterministic and fuzzy LP models, the conclusion presents benefits of the fuzzy LP model but is also stating that seeking the optimal plan of production means to accomplish the overall analysis that will encompass the LP model approaches.
文摘Objective: to assess the evolution of serum creatinine in patients undergoing radical nephrectomy (malignant) or total (benign), to identify risk factors connected with an unfavorable renal function outcome. Material and Methods: observational, transversal and retrospective study, through analysis of records and lab exams of 146 patients undergoing nephrectomy from January 2015 to December 2018. Results: Statistically significant difference was found between etiology and patients’ age (p-value Conclusion: This study shows that a large number of young patients undergo nephrectomy, many times avoidable;within a benign disease context with an increased risk of developing renal failure. Greater attention from the public service is required to tackle such chronic condition and its complications.
文摘Built-up area(BUA)significantly contributes to global greenhouse gas emissions,making strategic spatial planning crucial for carbon emission control.Given the diverse land use patterns and carbon emission sources in BUAs,this study proposed a land-based strategy system for carbon emission assessment and optimization.A three-step method was devised to create a planner-friendly tool for implementing the system,which involves carbon emission intensity calculation based on current land use,spatial illustration of carbon emission intensities based on land use planning,and planning program optimization and emission reduction effect assessment.The method was applied to the central urban area of Changxing County(Zhejiang)in China.The results showed that the structures and emission intensities of urban land use substantially influenced the overall carbon emissions in the central urban area.Our comprehensive land use optimization strategies reduced the overall carbon emissions of the central urban area by 36.9%when compared to the original planning program.The Monte Carlo simulation indicated that land use structure optimization and emission intensity control measures could reduce carbon emission rate by 5.20%to 18.28%,and 18.44%to 31.67%,respectively.The results underlined the importance of making specific adjustments to land use structure and implementing intensity control measures for effective carbon reduction.In conclusion,this study offers methods and insights for urban planners in creating sustainable and low-carbon urban spaces.
文摘The year 2018 marks the 40th anniversary of China’s reforms and opening to the world.As an important part of the overall reform effort,reform of the national family planning program,begun in the 1990s as a pilot project focused on quality of care,has achieved historic and significant results.The pilot project,conducted by the State Family Planning Commission of China in a few select areas,was a response to the 1994 International Conference on Population and Development in Cairo,as well as to a range of social and economic changes in China.To achieve quality of care,the pilot project adopted a client-centered approach to refocus China’s family planning efforts on client needs and rights,informed choice of contraceptives and the provision of better quality services.After nearly 10 years of trials,the successful experiences of the pilot project served as the basis of a family planning program reform rolled out nationwide.This paper uses a logic framework approach to review the main activities,outputs,and impacts of the pilot project.The paper argues that the quality of care project not only developed a model that facilitated reorientation of China’s earlier family planning efforts,but has also provided experiences and lessons that can serve as references for the implementation of“Healthy China 2030”in the future.
文摘China's Ministry of Science and Technology recently announced approval of China's National Basic Research Program (the 973 Program) and the Major Research Plan projects in 2008. Five Tsinghua research projects will be sponsored by the 973 Program and two by the Major Research Plan. Seven professors were appointed as chief scientists for the projects. Tsinghua has undertaken 28 projects since the 973 Program's inception involving 28 chief scientists and eight Major Research Plan projects involving eight chief scientists. Tsinghua is one of the country's leading institutions for supervision and conduct of the 973 Program projects.
基金Support System for Family Care for the Elderly in China,Japan and Korea"sponsored by Asia Research Center,Renmin University of China.
文摘In 2016 China began implementing a new population strategy after having maintained a one-child policy for 35 years.This paper draws on the lessons we can learn about low fertility and population aging in Japan and South Korea to consider the implications of the newly announced'universal two-child'policy in China.Japan,Korea and China share many socio-cultural characteristics and have undergone similar processes with respect to low fertility and population aging at different periods of time.Many scholars argue that China's family planning program has greatly reduced China's fertility level,but the effects of other socioeconomic factors have,in fact,had a greater impact on the reduction of the fertility rate than the one-child policy had.Considering the effects of the fertility policy that limits the number of births in China and the lessons we can get from unsuccessful fertility boosting measures in Japan and Korea,this paper suggests that a fertility policy that puts no limits on births should be adopted in China.
文摘Objective To calculate unmet need for contraception according to revised definition, mapping the contraception service needs and analyze factors related to the unmet need for contraception in Nusa Tenggara Barat (NTB). Methods This research design was cross sectional, using data from Indonesia Demographic and Health Survey 2012. Subjects were from 1 362 household, and were married women aged 15-49 years in NTB Province (685 women). Calculating method of unmet need for contraception used revised version, and analysis method was univariate, bivariate, and multivariate (Logistic regression). Results Majority of married women aged 15-49 years in NTB need contraception service (73.1%). However, it was known that met need for contraception was only 56.0%. Meanwhile, unmet need rate for contraception in NTB was 17.1%, specifically 11.5% for spacing and 5.6% for limiting. Factors contributing to unmet need for contraception in NTB were: household assets at above average (OR=O. 77), parity of 2-3 children (OR=0. 73), women with junior high school education level (0R=0.68), never be visited by health workers (OR=O. 68). Conclusions Factors that contribute to unmet need for contraception in NTB are household assets, parity, education level and visited by health workers. Government has to prioritize those f our factors in policy intervention and promotion of family planning participation program in NTB.