The history, current situation, and development trend of GIS (Geographic Information System) applied in the forest resources management were discussed in this paper. On the basis of geographic spatial characteristics ...The history, current situation, and development trend of GIS (Geographic Information System) applied in the forest resources management were discussed in this paper. On the basis of geographic spatial characteristics of forest resources data, a component geographic information system (ComGIS) was developed for forest resources management. The system embeds a GIS ActiveX control MapObjects (Inc. ESRI) on Visual C++ platform. System design, data organization and achieving way were studied and expatiated by taking Xigangzi Forestry Centre as study object. The system has many useful functions,, such as adding and display of various map layers, zoom of map by wheeling mouse, attribute and spatial data querying, map auto roaming, features rendering based on the spatial trait of data, label controlling through attribute data band with vector graph, as well as output of 'Column chart' for showing the result of statistics. At the same time, parts of source codes are attached.展开更多
The cloud radio access network(C-RAN) and the fog computing have been recently proposed to tackle the dramatically increasing traffic demands and to provide better quality of service(QoS) to user equipment(UE).Conside...The cloud radio access network(C-RAN) and the fog computing have been recently proposed to tackle the dramatically increasing traffic demands and to provide better quality of service(QoS) to user equipment(UE).Considering the better computation capability of the cloud RAN(10 times larger than that of the fog RAN) and the lower transmission delay of the fog computing,we propose a joint resource allocation and coordinated computation offloading algorithm for the fog RAN(F-RAN),which takes the advantage of C-RAN and fog computing.Specifically,the F-RAN splits a computation task into the fog computing part and the cloud computing part.Based on the constraints of maximum transmission delay tolerance,fronthaul and backhaul capacity limits,we minimize the energy cost and obtain optimal computational resource allocation for multiple UE,transmission power allocation of each UE and the event splitting factor.Numerical results have been proposed with the comparison of existing methods.展开更多
Information centric networking(ICN) is a new network architecture that is centred on accessing content. It aims to solve some of the problems associated with IP networks, increasing content distribution capability and...Information centric networking(ICN) is a new network architecture that is centred on accessing content. It aims to solve some of the problems associated with IP networks, increasing content distribution capability and improving users' experience. To analyse the requests' patterns and fully utilize the universal cached contents, a novel intelligent resources management system is proposed, which enables effi cient cache resource allocation in real time, based on changing user demand patterns. The system is composed of two parts. The fi rst part is a fi ne-grain traffi c estimation algorithm called Temporal Poisson traffi c prediction(TP2) that aims at analysing the traffi c pattern(or aggregated user requests' demands) for different contents. The second part is a collaborative cache placement algorithm that is based on traffic estimated by TP2. The experimental results show that TP2 has better performance than other comparable traffi c prediction algorithms and the proposed intelligent system can increase the utilization of cache resources and improve the network capacity.展开更多
This paper examines the hypothesis that non-native plant invasions are related to fluctuating resource availability as proposed by Davis et al. （2000）. I measured relative functional responses of both invasive and n...This paper examines the hypothesis that non-native plant invasions are related to fluctuating resource availability as proposed by Davis et al. （2000）. I measured relative functional responses of both invasive and native plants to changed resource availability due to nutrient enrichment and rainfall, and to increased disturbance. Data are presented from studies in two contrasting ecosystems. First is a series of glasshouse and field experiments on the invader Hieracium lepidulum and associated invasive and native species in subalpine temperate New Zealand. Second is a field study of invasive and native plant responses to altered disturbance regimes and rainfall from tropical savannas of north eastern Australia. Invaders responded differently from native species to changes in resource availability in both subalpine and tropical studies. However, invaders differed among themselves showing that different species exploit different functional niches to invade their respective habitats. These findings contribute to the contention that the fluctuating resource hypothesis does not provide a universal explanation for plant invasions. The diverse functional responses to increased resource availability among invaders in this and previous studies suggest that the cause of invasion depends on unique combinations of habitat and functional attributes of invaders and native assemblages. Such findings imply that universal predictions of what will happen under climate change scenarios across the globe will be difficult to make.展开更多
In centralized cellular network architecture,the concept of virtualized Base Station(VBS) becomes attracting since it enables all base stations(BSs) to share computing resources in a dynamic manner. This can significa...In centralized cellular network architecture,the concept of virtualized Base Station(VBS) becomes attracting since it enables all base stations(BSs) to share computing resources in a dynamic manner. This can significantly improve the utilization efficiency of computing resources. In this paper,we study the computing resource allocation strategy for one VBS by considering the non-negligible effect of delay introduced by switches. Specifically,we formulate the VBS's sum computing rate maximization as a set optimization problem. To address this problem,we firstly propose a computing resource schedule algorithm,namely,weight before one-step-greedy(WBOSG),which has linear computation complexity and considerable performance. Then,OSG retreat(OSG-R) algorithm is developed to further improve the system performance at the expense of computational complexity. Simulation results under practical setting are provided to validate the proposed two algorithms.展开更多
On August 24,2017,the Ministry of Land and Resources,Guangdong province and CNPC signed in Beijing a Strategic Cooperation Agreement on Promoting the Building of a Pilot Site for Exploring and Exploiting Gas Hydrate i...On August 24,2017,the Ministry of Land and Resources,Guangdong province and CNPC signed in Beijing a Strategic Cooperation Agreement on Promoting the Building of a Pilot Site for Exploring and Exploiting Gas Hydrate in the Shenhu Area of the South China Sea.The conclusion of this agreement will help accelerate the industrial development of gas hydrate in China,and展开更多
AIM To investigate the role of bloodtransfusion in TT viral infection(TTV).METHODS We retrospectively studied serumsamples from 192 transfusion recipients whounderwent cardiovascular surgery and bloodtransfusion betwe...AIM To investigate the role of bloodtransfusion in TT viral infection(TTV).METHODS We retrospectively studied serumsamples from 192 transfusion recipients whounderwent cardiovascular surgery and bloodtransfusion between July 1991 and June 1992.Allpatients had a follow-up every other week for atleast 6 months after transfusion.Eightyrecipients received blood before screeningdonors for hepatitis C antibody(anti-HCV),and112 recipients received screened blood.Recipients with alanine aminotransferase level】2.5 times the upper normal limit were testedfor serological markers for viral hepatitis A,B,C,G,Epstein-Barr virus and cytomegalovirus.TTV infection was defined by the positivity forserum TTV DNA using the polymerase chainreaction method.RESULTS Eleven and three patients,whoreceived anti-HCV unscreened and screened'blood,respectively,had serum ALT levels】90 IU/L.Five patients(HCV and TTV:1;HCV,HGV,and TTV:1;TTV:2;and CMV and TTV:1)were positive for TTV DNA,and four of them hadsero-conversion of TTV DNA.CONCLUSION TTV can be transmitted viablood transfusion.Two recipients infected byTTV alone may be associated with the hepatitis.However,whether TTV was the causal agentremains unsettled,and further studies arenecessary to define the role of TTV infection inchronic hepatitis.展开更多
The tracking, telemetry and command （TT＆C） mission is extremely reliable for its characters of small time horizon and high redundancy. The combined forcing and failure biasing （CFFB） method that is usually used f...The tracking, telemetry and command （TT＆C） mission is extremely reliable for its characters of small time horizon and high redundancy. The combined forcing and failure biasing （CFFB） method that is usually used for simulating the unreliability of the highly dependable mission system seems not so efficient for the TT＆C mission. The concept about the importance of failure transition is proposed based on the logical relationship between TT＆C mission and its involved resources. Then, the importance is used for readjusting the transition rate of the failure transition when using the forcing and failure biasing during the simulation. Examples show that the improved CFFB method can evidently increase the occurrence of the TT＆C mission failure event and decrease the sample variance. More redundancy of the TT＆C mission leads to the improved CFFB method more efficient.展开更多
基金This work was supported by Provincial Key Technologies R and D program of Heilongjiang (GC02B608)
文摘The history, current situation, and development trend of GIS (Geographic Information System) applied in the forest resources management were discussed in this paper. On the basis of geographic spatial characteristics of forest resources data, a component geographic information system (ComGIS) was developed for forest resources management. The system embeds a GIS ActiveX control MapObjects (Inc. ESRI) on Visual C++ platform. System design, data organization and achieving way were studied and expatiated by taking Xigangzi Forestry Centre as study object. The system has many useful functions,, such as adding and display of various map layers, zoom of map by wheeling mouse, attribute and spatial data querying, map auto roaming, features rendering based on the spatial trait of data, label controlling through attribute data band with vector graph, as well as output of 'Column chart' for showing the result of statistics. At the same time, parts of source codes are attached.
基金supported in part by National Natural Science Foundation of China(No. 61372070)Natural Science Basic Research Plan in Shaanxi Province of China(No. 2015JM6324)+3 种基金Ningbo Natural Science Foundation(2015A610117)Hong Kong, Macao and Taiwan Science & Technology Cooperation Program of China(No. 2015DFT10160)EU FP7 Project MONICA (No.PIRSES-GA-2011-295222)the 111 Project(No.B08038)
文摘The cloud radio access network(C-RAN) and the fog computing have been recently proposed to tackle the dramatically increasing traffic demands and to provide better quality of service(QoS) to user equipment(UE).Considering the better computation capability of the cloud RAN(10 times larger than that of the fog RAN) and the lower transmission delay of the fog computing,we propose a joint resource allocation and coordinated computation offloading algorithm for the fog RAN(F-RAN),which takes the advantage of C-RAN and fog computing.Specifically,the F-RAN splits a computation task into the fog computing part and the cloud computing part.Based on the constraints of maximum transmission delay tolerance,fronthaul and backhaul capacity limits,we minimize the energy cost and obtain optimal computational resource allocation for multiple UE,transmission power allocation of each UE and the event splitting factor.Numerical results have been proposed with the comparison of existing methods.
基金supported by the National High Technology Research and Development Program(863)of China(No.2015AA016101)the National Natural Science Fund(No.61300184)Beijing Nova Program(No.Z151100000315078)
文摘Information centric networking(ICN) is a new network architecture that is centred on accessing content. It aims to solve some of the problems associated with IP networks, increasing content distribution capability and improving users' experience. To analyse the requests' patterns and fully utilize the universal cached contents, a novel intelligent resources management system is proposed, which enables effi cient cache resource allocation in real time, based on changing user demand patterns. The system is composed of two parts. The fi rst part is a fi ne-grain traffi c estimation algorithm called Temporal Poisson traffi c prediction(TP2) that aims at analysing the traffi c pattern(or aggregated user requests' demands) for different contents. The second part is a collaborative cache placement algorithm that is based on traffic estimated by TP2. The experimental results show that TP2 has better performance than other comparable traffi c prediction algorithms and the proposed intelligent system can increase the utilization of cache resources and improve the network capacity.
文摘This paper examines the hypothesis that non-native plant invasions are related to fluctuating resource availability as proposed by Davis et al. （2000）. I measured relative functional responses of both invasive and native plants to changed resource availability due to nutrient enrichment and rainfall, and to increased disturbance. Data are presented from studies in two contrasting ecosystems. First is a series of glasshouse and field experiments on the invader Hieracium lepidulum and associated invasive and native species in subalpine temperate New Zealand. Second is a field study of invasive and native plant responses to altered disturbance regimes and rainfall from tropical savannas of north eastern Australia. Invaders responded differently from native species to changes in resource availability in both subalpine and tropical studies. However, invaders differed among themselves showing that different species exploit different functional niches to invade their respective habitats. These findings contribute to the contention that the fluctuating resource hypothesis does not provide a universal explanation for plant invasions. The diverse functional responses to increased resource availability among invaders in this and previous studies suggest that the cause of invasion depends on unique combinations of habitat and functional attributes of invaders and native assemblages. Such findings imply that universal predictions of what will happen under climate change scenarios across the globe will be difficult to make.
基金funded by the key project of the National Natural Science Foundation of China (No.61431001)the National High-Tech R&D Program (863 Program 2015AA01A705)New Technology Star Plan of Beijing (No.xx2013052)
文摘In centralized cellular network architecture,the concept of virtualized Base Station(VBS) becomes attracting since it enables all base stations(BSs) to share computing resources in a dynamic manner. This can significantly improve the utilization efficiency of computing resources. In this paper,we study the computing resource allocation strategy for one VBS by considering the non-negligible effect of delay introduced by switches. Specifically,we formulate the VBS's sum computing rate maximization as a set optimization problem. To address this problem,we firstly propose a computing resource schedule algorithm,namely,weight before one-step-greedy(WBOSG),which has linear computation complexity and considerable performance. Then,OSG retreat(OSG-R) algorithm is developed to further improve the system performance at the expense of computational complexity. Simulation results under practical setting are provided to validate the proposed two algorithms.
文摘On August 24,2017,the Ministry of Land and Resources,Guangdong province and CNPC signed in Beijing a Strategic Cooperation Agreement on Promoting the Building of a Pilot Site for Exploring and Exploiting Gas Hydrate in the Shenhu Area of the South China Sea.The conclusion of this agreement will help accelerate the industrial development of gas hydrate in China,and
文摘AIM To investigate the role of bloodtransfusion in TT viral infection(TTV).METHODS We retrospectively studied serumsamples from 192 transfusion recipients whounderwent cardiovascular surgery and bloodtransfusion between July 1991 and June 1992.Allpatients had a follow-up every other week for atleast 6 months after transfusion.Eightyrecipients received blood before screeningdonors for hepatitis C antibody(anti-HCV),and112 recipients received screened blood.Recipients with alanine aminotransferase level】2.5 times the upper normal limit were testedfor serological markers for viral hepatitis A,B,C,G,Epstein-Barr virus and cytomegalovirus.TTV infection was defined by the positivity forserum TTV DNA using the polymerase chainreaction method.RESULTS Eleven and three patients,whoreceived anti-HCV unscreened and screened'blood,respectively,had serum ALT levels】90 IU/L.Five patients(HCV and TTV:1;HCV,HGV,and TTV:1;TTV:2;and CMV and TTV:1)were positive for TTV DNA,and four of them hadsero-conversion of TTV DNA.CONCLUSION TTV can be transmitted viablood transfusion.Two recipients infected byTTV alone may be associated with the hepatitis.However,whether TTV was the causal agentremains unsettled,and further studies arenecessary to define the role of TTV infection inchronic hepatitis.
基金supported by the National Natural Science Foundation of China (71071159)
文摘The tracking, telemetry and command （TT＆C） mission is extremely reliable for its characters of small time horizon and high redundancy. The combined forcing and failure biasing （CFFB） method that is usually used for simulating the unreliability of the highly dependable mission system seems not so efficient for the TT＆C mission. The concept about the importance of failure transition is proposed based on the logical relationship between TT＆C mission and its involved resources. Then, the importance is used for readjusting the transition rate of the failure transition when using the forcing and failure biasing during the simulation. Examples show that the improved CFFB method can evidently increase the occurrence of the TT＆C mission failure event and decrease the sample variance. More redundancy of the TT＆C mission leads to the improved CFFB method more efficient.
