According to low earth orbit（LEO） satellite systems with users of different levels, a dynamic channel reservation scheme based on priorities is proposed. Dynamic calculation of the thresholds for reserved channels i...According to low earth orbit（LEO） satellite systems with users of different levels, a dynamic channel reservation scheme based on priorities is proposed. Dynamic calculation of the thresholds for reserved channels is the key of this strategy. In order to obtain the optimal thresholds, the traffic is predicted based on the high-speed deterministic movement property of LEO satellites firstly. Then, a channel allocation model based on Markov is established. Finally, the solution of the model is obtained based on the genetic algorithm. Without user location, this strategy effectively reduces handover failures and improves channel utilization by adjusting dynamically the thresholds according to traffic conditions. The simulation results show that the system＇s overall quality of service can be improved by this strategy.展开更多
Call admission control (CAC) and resource reservation (RR) for mobile communication are two important factors that guarantee system efficiency and quality of service (QoS) required for different services in a very sca...Call admission control (CAC) and resource reservation (RR) for mobile communication are two important factors that guarantee system efficiency and quality of service (QoS) required for different services in a very scarce resource as the radio spectrum. A new scheme was proposed which extends the concepts of resource sharing and reservations for wideband code division multiple access (WCDMA) systems with a unique feature of soft capacity. Voice and data traffic were considered. The traffic is further classified into handoff and new requests. The reservation thresholds were dynamically adjusted according to the traffic pattern and mobility prediction in order to achieve the maximum channel utilization, while guaranteeing different QoS constraints. The performance of proposed scheme was evaluated using Markov models. New call blocking probability, handoff call dropping probability, and channel utilization were used as benchmarks for the proposed scheme.展开更多
Objective To evaluate the association of GGN repeat polymorphism of androgen receptor(AR)with ovarian reserve and ovarian response in controlled ovarian stimulation(COS).Methods This genetic association study was cond...Objective To evaluate the association of GGN repeat polymorphism of androgen receptor(AR)with ovarian reserve and ovarian response in controlled ovarian stimulation(COS).Methods This genetic association study was conducted among a total of 361 women aged≤40 years with basal FSH≤12 U/L undergoing the GnRH-agonist long protocol for COS in a university affiliated IVF center.GGN repeat in the AR gene was analyzed with Sanger sequencing.The primary endpoint was the number of antral follicle counts(AFCs),and the secondary endpoints were stimulation days,total dose of gonadotropin(Gn)used,total number of retrieved oocytes,ovarian sensitivity index,and follicular output rate.Results The GGN repeat in exon 1 of the AR gene ranged from 13 to 24,and the median repeat length was 22.Based on the genotypes(S for GGN repeats<22,L for GGN repeats≥22),the patients were divided into 3 groups:SS,SL,and LL.Generalized regression analysis indicated that the number of AFCs in group SS was significantly lower than those in group SL(adjusted β=1.8,95%CI:0.2-3.4,P=0.024)and group LL(adjusted β=1.5,95%CI:0.2-2.7,P=0.021).No significant difference was observed in the number of AFCs between group SL and group LL(P>0.05).Generalized regression analysis indicated no significant differences in ovarian stimulation parameters among the 3 groups,either before or after adjusting for confounding factors(P>0.05).Conclusion GGN repeat length on the AR gene is associated with AFC but not with ovarian response in Chinese women,indicating that AR gene polymorphisms may affect ovarian reserve.展开更多
Demand assignment MAC protocols have been used widely in wireless networks. It can effectively utilize wireless bandwidth. Some strategies can he used by demand assignment MAC protocols to further improve their effici...Demand assignment MAC protocols have been used widely in wireless networks. It can effectively utilize wireless bandwidth. Some strategies can he used by demand assignment MAC protocols to further improve their efficiency. The concept of transmit probability is introduced. This concept allows a request slot to be assigned to many different traffic classes at the same time. Based on it, the dynamic random channel reservation （DRCR） protocol is proposed. The DRCR protocol operates dynamically by observing the traffic conditions. It uses information about the recent traffic conditions to assign transmit probability with which an mobile station can select request slots with lower traffic. The performance of DRCR is evaluated and compared with RSCA. The results show that DRCR is more stable than RSCA, it offers shorter delays of requests than RSCA and can relieve heavily stressed traffic classes faster than RSCA.展开更多
By the aid of the international mining software SURPAC, a geologic database for a multi-metal mine was established, 3D models of the surface, geologic fault, ore body, cavity and the underground openings were built, a...By the aid of the international mining software SURPAC, a geologic database for a multi-metal mine was established, 3D models of the surface, geologic fault, ore body, cavity and the underground openings were built, and the volume of the cavity of the mine based on the cavity 3D model was calculated. In order to compute the reserves, a grade block model was built and each metal element grade was estimated using Ordinary Kriging. Then, the reserve of each metal element and every sublevel of the mine was worked out. Finally, the calculated result of each metal reserve to its actual prospecting reserve was compared, and the results show that they are all almost equal to each other. The absolute errors of Sn, Pb, and Zn reserves are only 1.45%, 1.59% and 1.62%, respectively. Obviously, the built models are reliable and the calculated results of reserves are correct. They can be used to assist the geologic and mining engineers of the mine to do research work of reserves estimation, mining design, plan making and so on.展开更多
With the gradual attention of the state to the protection of natural ecological environment,the planning and layout of the nature reserve will overlap with some coal mine areas.In order to strengthen the construction ...With the gradual attention of the state to the protection of natural ecological environment,the planning and layout of the nature reserve will overlap with some coal mine areas.In order to strengthen the construction of ecological civilization,it is necessary to study the impact of mining on the ecological environment of the nature reserve.Through the methods of GIS and RS,and evaluation of ecological protection index system,the differences and impacts of ecological environment changes before and after the planning of the nature reserve are analyzed.The results show that since 2002,the effect of water collection and artificial soil and water conservation measures on improving the ecological environment of vegetation are obvious,the dominant species of vegetation type in the overlapping area of coal mine and nature reserve have changed from grass vegetation to shrub vegetation,in which the area of arbor forest land has increased significantly,the vegetation coverage in the overlapping area has also increased considerably.The intensity of soil erosion has decreased year by year after mining the coal resources.Post-harvest hydraulic erosion intensity is mainly below mild,and the area of artificial soil and water conservation has increased significantly.The negative impact of the ground subsidence caused by coal mining on the ecological environment is less than the positive effect brought by artificial soil and water conservation measures,and it is generally developing in a more stable direction.The ecological protection status index increased from 32.98 to 45.94,and the change degree of ecological protection status in nature reserves is 12.9≥10.The ecological protection status of the nature reserve improved significantly.On the basis of ecological environment protection and restoration measures in the nature reserve,coal mines need to further study the comprehensive impact of human activities on the ecological environment of the nature reserve.展开更多
A novel approach was proposed to allocate spinning reserve for dynamic economic dispatch.The proposed approach set up a two-stage stochastic programming model to allocate reserve.The model was solved using a decompose...A novel approach was proposed to allocate spinning reserve for dynamic economic dispatch.The proposed approach set up a two-stage stochastic programming model to allocate reserve.The model was solved using a decomposed algorithm based on Benders' decomposition.The model and the algorithm were applied to a simple 3-node system and an actual 445-node system for verification,respectively.Test results show that the model can save 84.5 US $ cost for the testing three-node system,and the algorithm can solve the model for 445-node system within 5 min.The test results also illustrate that the proposed approach is efficient and suitable for large system calculation.展开更多
This paper discussed how to protect and control the quality of wild Chinese herbal medicine resources in nature reserves by taking Longyuwan National Forest Park within Funiu Mountain Nature Reserve as an example. Thr...This paper discussed how to protect and control the quality of wild Chinese herbal medicine resources in nature reserves by taking Longyuwan National Forest Park within Funiu Mountain Nature Reserve as an example. Through the combination of three methods including literature review, visiting and investigational studies, and field surveys, the data of investigation, collection and collation were analyzed. According to data of surveys, collection and collation, problems related to the protection of wild Chinese herbal medicine resources faced by Longyuwan Scenic Spot within Funiu Mountain Nature Reserve were also analyzed and protection strategies and quality control of wild Chinese herbal medicine resources in this nature reserve were discussed. It was expected that the results would provide important scientific references for the sustainable development, protection and quality control of wild Chinese herbal medicine resources within nature reserves.展开更多
Natural reserve can provide ecology system with natural background for human being and has important significance for sustaining ecosystem service.The continuous damage and deterioration of ecosystem in natural reserv...Natural reserve can provide ecology system with natural background for human being and has important significance for sustaining ecosystem service.The continuous damage and deterioration of ecosystem in natural reserve caused by human activities have become one of the most serious environmental problems.The conflict between local展开更多
Already Bangladesh has proven to be a natural gas giant in the region and to the energy producing community of the world.The Bangladesh sub-surface is according to the present knowledge mainly gas prone,with some pote...Already Bangladesh has proven to be a natural gas giant in the region and to the energy producing community of the world.The Bangladesh sub-surface is according to the present knowledge mainly gas prone,with some potential for future oil discoveries. Within the 144549 km^2 territory,Bangladesh has展开更多
As a significant inducement during the development of oil and gas,the role of remaining recoverable reserves is more observable especially in the later phase of development of oilfield.Depended on the production decli...As a significant inducement during the development of oil and gas,the role of remaining recoverable reserves is more observable especially in the later phase of development of oilfield.Depended on the production decline method in petroleum reservoir engineering,a new model of predicting recoverable and remaining recoverable reserves has been展开更多
Many karst geodes have been found in the pure Iimestone on the top Maokou formation (Permian) in the axial part of anticlines and lower part hydrological networks in Chongqing region. It is sometimes a reservoir natur...Many karst geodes have been found in the pure Iimestone on the top Maokou formation (Permian) in the axial part of anticlines and lower part hydrological networks in Chongqing region. It is sometimes a reservoir natural gas. Calcite megacryst decorates the wall of the geodes which believed to he formed in Tertiary.展开更多
Soil organic carbon reserve is an important parameter for the study of carbon cycle and global change.Using the measured data of the multi-purpose regional geochemical survey,we estimated the SOC densities and reserve...Soil organic carbon reserve is an important parameter for the study of carbon cycle and global change.Using the measured data of the multi-purpose regional geochemical survey,we estimated the SOC densities and reserves of various land types in Jilin mid-west area.We found that chermozem’s organic carbon reserve is the highest,and dark brown soil’s and black soil’s are also quite high.Then,we carried a comparison research with the date of the second soil general survey.The result shows that the organic carbon densities of many soil types has increased,and among them chestnut soil,dark brown soil and brown soil are the most significant.Furthermore,We studied the change of soil organic carbon reserve in western Jilin during 1989-2004,which was caused by展开更多
基金supported by the National Natural Science Foundation of China(7130108161373137)+1 种基金the Natural Science Foundation of Jiangsu Province(BK20130877BK2012833)
文摘According to low earth orbit（LEO） satellite systems with users of different levels, a dynamic channel reservation scheme based on priorities is proposed. Dynamic calculation of the thresholds for reserved channels is the key of this strategy. In order to obtain the optimal thresholds, the traffic is predicted based on the high-speed deterministic movement property of LEO satellites firstly. Then, a channel allocation model based on Markov is established. Finally, the solution of the model is obtained based on the genetic algorithm. Without user location, this strategy effectively reduces handover failures and improves channel utilization by adjusting dynamically the thresholds according to traffic conditions. The simulation results show that the system＇s overall quality of service can be improved by this strategy.
文摘Call admission control (CAC) and resource reservation (RR) for mobile communication are two important factors that guarantee system efficiency and quality of service (QoS) required for different services in a very scarce resource as the radio spectrum. A new scheme was proposed which extends the concepts of resource sharing and reservations for wideband code division multiple access (WCDMA) systems with a unique feature of soft capacity. Voice and data traffic were considered. The traffic is further classified into handoff and new requests. The reservation thresholds were dynamically adjusted according to the traffic pattern and mobility prediction in order to achieve the maximum channel utilization, while guaranteeing different QoS constraints. The performance of proposed scheme was evaluated using Markov models. New call blocking probability, handoff call dropping probability, and channel utilization were used as benchmarks for the proposed scheme.
文摘Objective To evaluate the association of GGN repeat polymorphism of androgen receptor(AR)with ovarian reserve and ovarian response in controlled ovarian stimulation(COS).Methods This genetic association study was conducted among a total of 361 women aged≤40 years with basal FSH≤12 U/L undergoing the GnRH-agonist long protocol for COS in a university affiliated IVF center.GGN repeat in the AR gene was analyzed with Sanger sequencing.The primary endpoint was the number of antral follicle counts(AFCs),and the secondary endpoints were stimulation days,total dose of gonadotropin(Gn)used,total number of retrieved oocytes,ovarian sensitivity index,and follicular output rate.Results The GGN repeat in exon 1 of the AR gene ranged from 13 to 24,and the median repeat length was 22.Based on the genotypes(S for GGN repeats<22,L for GGN repeats≥22),the patients were divided into 3 groups:SS,SL,and LL.Generalized regression analysis indicated that the number of AFCs in group SS was significantly lower than those in group SL(adjusted β=1.8,95%CI:0.2-3.4,P=0.024)and group LL(adjusted β=1.5,95%CI:0.2-2.7,P=0.021).No significant difference was observed in the number of AFCs between group SL and group LL(P>0.05).Generalized regression analysis indicated no significant differences in ovarian stimulation parameters among the 3 groups,either before or after adjusting for confounding factors(P>0.05).Conclusion GGN repeat length on the AR gene is associated with AFC but not with ovarian response in Chinese women,indicating that AR gene polymorphisms may affect ovarian reserve.
文摘Demand assignment MAC protocols have been used widely in wireless networks. It can effectively utilize wireless bandwidth. Some strategies can he used by demand assignment MAC protocols to further improve their efficiency. The concept of transmit probability is introduced. This concept allows a request slot to be assigned to many different traffic classes at the same time. Based on it, the dynamic random channel reservation （DRCR） protocol is proposed. The DRCR protocol operates dynamically by observing the traffic conditions. It uses information about the recent traffic conditions to assign transmit probability with which an mobile station can select request slots with lower traffic. The performance of DRCR is evaluated and compared with RSCA. The results show that DRCR is more stable than RSCA, it offers shorter delays of requests than RSCA and can relieve heavily stressed traffic classes faster than RSCA.
基金Project(50490274) supported by the National Natural Science Foundation of China
文摘By the aid of the international mining software SURPAC, a geologic database for a multi-metal mine was established, 3D models of the surface, geologic fault, ore body, cavity and the underground openings were built, and the volume of the cavity of the mine based on the cavity 3D model was calculated. In order to compute the reserves, a grade block model was built and each metal element grade was estimated using Ordinary Kriging. Then, the reserve of each metal element and every sublevel of the mine was worked out. Finally, the calculated result of each metal reserve to its actual prospecting reserve was compared, and the results show that they are all almost equal to each other. The absolute errors of Sn, Pb, and Zn reserves are only 1.45%, 1.59% and 1.62%, respectively. Obviously, the built models are reliable and the calculated results of reserves are correct. They can be used to assist the geologic and mining engineers of the mine to do research work of reserves estimation, mining design, plan making and so on.
基金National Key Research and Development Program of China(2017YFC0804100)Science and Technology Innovation Fund of Xi′an Research Institute of China Coal Technology&Engineering Group Corp(2017XAYZD012)。
文摘With the gradual attention of the state to the protection of natural ecological environment,the planning and layout of the nature reserve will overlap with some coal mine areas.In order to strengthen the construction of ecological civilization,it is necessary to study the impact of mining on the ecological environment of the nature reserve.Through the methods of GIS and RS,and evaluation of ecological protection index system,the differences and impacts of ecological environment changes before and after the planning of the nature reserve are analyzed.The results show that since 2002,the effect of water collection and artificial soil and water conservation measures on improving the ecological environment of vegetation are obvious,the dominant species of vegetation type in the overlapping area of coal mine and nature reserve have changed from grass vegetation to shrub vegetation,in which the area of arbor forest land has increased significantly,the vegetation coverage in the overlapping area has also increased considerably.The intensity of soil erosion has decreased year by year after mining the coal resources.Post-harvest hydraulic erosion intensity is mainly below mild,and the area of artificial soil and water conservation has increased significantly.The negative impact of the ground subsidence caused by coal mining on the ecological environment is less than the positive effect brought by artificial soil and water conservation measures,and it is generally developing in a more stable direction.The ecological protection status index increased from 32.98 to 45.94,and the change degree of ecological protection status in nature reserves is 12.9≥10.The ecological protection status of the nature reserve improved significantly.On the basis of ecological environment protection and restoration measures in the nature reserve,coal mines need to further study the comprehensive impact of human activities on the ecological environment of the nature reserve.
基金Projects(51007047,51077087)supported by the National Natural Science Foundation of ChinaProject(2013CB228205)supported by the National Key Basic Research Program of China+1 种基金Project(20100131120039)supported by Higher Learning Doctor Discipline End Scientific Research Fund of the Ministry of Education Institution,ChinaProject(ZR2010EQ035)supported by the Natural Science Foundation of Shandong Province,China
文摘A novel approach was proposed to allocate spinning reserve for dynamic economic dispatch.The proposed approach set up a two-stage stochastic programming model to allocate reserve.The model was solved using a decomposed algorithm based on Benders' decomposition.The model and the algorithm were applied to a simple 3-node system and an actual 445-node system for verification,respectively.Test results show that the model can save 84.5 US $ cost for the testing three-node system,and the algorithm can solve the model for 445-node system within 5 min.The test results also illustrate that the proposed approach is efficient and suitable for large system calculation.
基金Supported by Funding from the State Nationalities Affairs Commission(2015-GM-178)National Training Programs of Innovation and Entrepreneurship for Undergraduates(GCYS2016110001)
文摘This paper discussed how to protect and control the quality of wild Chinese herbal medicine resources in nature reserves by taking Longyuwan National Forest Park within Funiu Mountain Nature Reserve as an example. Through the combination of three methods including literature review, visiting and investigational studies, and field surveys, the data of investigation, collection and collation were analyzed. According to data of surveys, collection and collation, problems related to the protection of wild Chinese herbal medicine resources faced by Longyuwan Scenic Spot within Funiu Mountain Nature Reserve were also analyzed and protection strategies and quality control of wild Chinese herbal medicine resources in this nature reserve were discussed. It was expected that the results would provide important scientific references for the sustainable development, protection and quality control of wild Chinese herbal medicine resources within nature reserves.
文摘Natural reserve can provide ecology system with natural background for human being and has important significance for sustaining ecosystem service.The continuous damage and deterioration of ecosystem in natural reserve caused by human activities have become one of the most serious environmental problems.The conflict between local
文摘Already Bangladesh has proven to be a natural gas giant in the region and to the energy producing community of the world.The Bangladesh sub-surface is according to the present knowledge mainly gas prone,with some potential for future oil discoveries. Within the 144549 km^2 territory,Bangladesh has
文摘As a significant inducement during the development of oil and gas,the role of remaining recoverable reserves is more observable especially in the later phase of development of oilfield.Depended on the production decline method in petroleum reservoir engineering,a new model of predicting recoverable and remaining recoverable reserves has been
文摘Many karst geodes have been found in the pure Iimestone on the top Maokou formation (Permian) in the axial part of anticlines and lower part hydrological networks in Chongqing region. It is sometimes a reservoir natural gas. Calcite megacryst decorates the wall of the geodes which believed to he formed in Tertiary.
文摘Soil organic carbon reserve is an important parameter for the study of carbon cycle and global change.Using the measured data of the multi-purpose regional geochemical survey,we estimated the SOC densities and reserves of various land types in Jilin mid-west area.We found that chermozem’s organic carbon reserve is the highest,and dark brown soil’s and black soil’s are also quite high.Then,we carried a comparison research with the date of the second soil general survey.The result shows that the organic carbon densities of many soil types has increased,and among them chestnut soil,dark brown soil and brown soil are the most significant.Furthermore,We studied the change of soil organic carbon reserve in western Jilin during 1989-2004,which was caused by
