The current multicast model provides no access control mechanism. Any host can send data directly to a multicast address or join a multicast group to become a member, which brings safety problems to multicast. In this...The current multicast model provides no access control mechanism. Any host can send data directly to a multicast address or join a multicast group to become a member, which brings safety problems to multicast. In this paper, we present a new active multicast group access control mechanism that is founded on trust management. This structure can solve the problem that exists in multicast members' access control and distributing authorization of traditional IP multicast.展开更多
Water scarcity is a major problem for Namibia and South Africa as both countries are classified as "water stressed", based on their per capita water availability which is below the threshold of 1,000-1,666 ma-person...Water scarcity is a major problem for Namibia and South Africa as both countries are classified as "water stressed", based on their per capita water availability which is below the threshold of 1,000-1,666 ma-person^-1.year^-1. Water provision in both countries has traditionally relied on supply-side sources, and the potential for expansion is becoming dim, making efforts towards demand management approaches more feasible. Findings show that CBM (community based management) systems of water points offer an alternative in terms of ownership and self-reliance based on institutional arrangements at community level. However, the CBM system involves some forms of payment for water access, and affordability has become a main challenge, to the extent that some governments are considering the reintroduction of water subsidies for poor rural communities in the near future.展开更多
A new web product data management architecture is presented. The three-tier web architecture and Simple Object Access Protocol (SOAP) are combined to build the web-based product data management (PDM) system which incl...A new web product data management architecture is presented. The three-tier web architecture and Simple Object Access Protocol (SOAP) are combined to build the web-based product data management (PDM) system which includes three tiers: the user services tier, the business services tier, and the data services tier. The client service component uses the server-side technology, and Extensible Markup Language (XML) web service which uses SOAP as the communication protocol is chosen as the business service component. To illustrate how to build a web-based PDM system using the proposed architecture, a case PDM system which included three logical tires was built. To use the security and central management features of the database, a stored procedure was recommended in the data services tier. The business object was implemented as an XML web service so that client could use standard internet protocols to communicate with the business object from any platform. In order to satisfy users using all sorts of browser, the server-side technology and Microsoft ASP.NET was used to create the dynamic user interface.展开更多
Objective To introduce the accession procedure and evaluation of PIC/S,and help relevant departments in China to understand the requirements of PIC/S in detail,and to promote the process of China’s entry into PIC/S.M...Objective To introduce the accession procedure and evaluation of PIC/S,and help relevant departments in China to understand the requirements of PIC/S in detail,and to promote the process of China’s entry into PIC/S.Methods The procedures and steps of joining PIC/S,the evaluation process of PIC/S,and the experience of several countries in joining PIC/S were introduced and analyzed,which could help the relevant personnel in China understand the specific contents.Results and Conclusion According to the requirements of PIC/S,it is necessary to establish a unified GMP quality management system.展开更多
随着云计算的快速发展及其普及,企业的传统数据安全边界被打破,出现云资产管理混乱、越权、误操作等现象,对用户的信息安全产生巨大威胁。基于此,对目前云计算环境下身份认证和访问管理(identity and access management,IAM)的安全问题...随着云计算的快速发展及其普及,企业的传统数据安全边界被打破,出现云资产管理混乱、越权、误操作等现象,对用户的信息安全产生巨大威胁。基于此,对目前云计算环境下身份认证和访问管理(identity and access management,IAM)的安全问题进行研究,提出结合内生安全思想,采取拟态防御手段构建出一种具有内生安全效应的拟态身份认证和访问管理(mimicry identity and access management,MIAM)体系架构方案,并对其进行详细描述。将该方案分别进行稳定性测试、系统性能测试以及系统安全性评估,实验数据表明,该方案具有可行性和安全性。展开更多
Transcatheter aortic valve implantation(TAVI) using stent-based bioprostheses has recently emerged as a promising alternative to surgical valve replacement in selected patients. The main route for TAVI is retrograde a...Transcatheter aortic valve implantation(TAVI) using stent-based bioprostheses has recently emerged as a promising alternative to surgical valve replacement in selected patients. The main route for TAVI is retrograde access from the femoral artery using large sheaths(16-24 F). Vascular access complications are a clinically relevant issue in TAVI procedures since they are reported to occur in up to one fourth of patients and are strongly associated with adverse outcomes. In the present paper, we review the different types of vascular access site complications associated with transfemoral TAVI. Moreover, we discuss the possible optimal management strategies with particular attention to the relevance of early diagnosis and prompt treatment using endovascular techniques.展开更多
Dynamic spectrum access technologies based on Cognitive Radio(CR) is under intensive research carried out by the wireless communication society and is expected to solve the problem of spectrum scarcity.However,most en...Dynamic spectrum access technologies based on Cognitive Radio(CR) is under intensive research carried out by the wireless communication society and is expected to solve the problem of spectrum scarcity.However,most enabling technologies related to dynamic spectrum access are con-sidered individually.In this paper,we consider these key technologies jointly and introduce a new implementation scheme for a Dynamic Spectrum Access Network Based on Cognitive Radio(DSAN-BCR).We start with a flexible hardware platform for DSAN-BCR,as well as a flexible protocol structure that dominates the operation of DSAN-BCR.We then focus on the state of the art of key technologies such as spectrum sensing,spectrum resources management,dynamic spectrum access,and routing that are below the network layer in DSAN-BCR,as well as the development of technologies related to higher layers.Last but not the least,we analyze the challenges confronted by these men-tioned technologies in DSAN-BCR,and give the perspectives on the future development of these technologies.The DSAN-BCR introduced is expected to provide a system level guidance to alleviate the problem of spectrum scarcity.展开更多
Abstract: Two-tier heterogeneous networks (HetNets), where the current cellular networks, i.e., macrocells, are overlapped with a large number of randomly distributed femtocells, can potentially bring significant b...Abstract: Two-tier heterogeneous networks (HetNets), where the current cellular networks, i.e., macrocells, are overlapped with a large number of randomly distributed femtocells, can potentially bring significant benefits to spectral utilization and system capacity. The interference management and access control for open and closed femtocells in two-tier HetNets were focused. The contributions consist of two parts. Firstly, in order to reduce the uplink interference caused by MUEs (macrocell user equipments) at closed femtocells, an incentive mechanism to implement interference mitigation was proposed. It encourages femtoeells that work with closed-subscriber-group (CSG) to allow the interfering MUEs access in but only via uplink, which can reduce the interference significantly and also benefit the marco-tier. The interference issue was then studied in open-subscriber-group (OSG) femtocells from the perspective of handover and mobility prediction. Inbound handover provides an alternative solution for open femtocells when interference turns up, while this accompanies with PCI (physical cell identity) confusion during inbound handover. To reduce the PCI confusion, a dynamic PCI allocation scheme was proposed, by which the high handin femtocells have the dedicated PCI while the others share the reuse PCIs. A Markov chain based mobility prediction algorithm was designed to decide whether the femtoeell status is with high handover requests. Numerical analysis reveals that the UL interference is managed well for the CSG femtocell and the PCI confusion issue is mitigated greatly in OSG femtocell compared to the conventional approaches.展开更多
PMI (privilege management infrastructure) is used to perform access control to resource in an E-commerce or E-government system. With the ever-increasing need for secure transaction, the need for systems that offer ...PMI (privilege management infrastructure) is used to perform access control to resource in an E-commerce or E-government system. With the ever-increasing need for secure transaction, the need for systems that offer a wide variety of QoS (quality-of-service) features is also growing. In order to improve the QoS of PMI system, a cache based on RBAC (Role-based Access control) and trust is proposed. Our system is realized based on Web service. How to design the cache based on RBAC and trust in the access control model is deseribed in detail. The algorithm to query role permission in cache and to add records in cache is dealt with. The policy to update cache is introduced also.展开更多
Due to the recent trend of software intelligence in the Fourth Industrial Revolution,deep learning has become a mainstream workload for modern computer systems.Since the data size of deep learning increasingly grows,m...Due to the recent trend of software intelligence in the Fourth Industrial Revolution,deep learning has become a mainstream workload for modern computer systems.Since the data size of deep learning increasingly grows,managing the limited memory capacity efficiently for deep learning workloads becomes important.In this paper,we analyze memory accesses in deep learning workloads and find out some unique characteristics differentiated from traditional workloads.First,when comparing instruction and data accesses,data access accounts for 96%–99%of total memory accesses in deep learning workloads,which is quite different from traditional workloads.Second,when comparing read and write accesses,write access dominates,accounting for 64%–80%of total memory accesses.Third,although write access makes up the majority of memory accesses,it shows a low access bias of 0.3 in the Zipf parameter.Fourth,in predicting re-access,recency is important in read access,but frequency provides more accurate information in write access.Based on these observations,we introduce a Non-Volatile Random Access Memory(NVRAM)-accelerated memory architecture for deep learning workloads,and present a new memory management policy for this architecture.By considering the memory access characteristics of deep learning workloads,the proposed policy improves memory performance by 64.3%on average compared to the CLOCK policy.展开更多
Management of recreational access on public forest lands is a complex issue of growing global importance. The provision of public recreation opportunities is part of the suite of ecological goods and services that mus...Management of recreational access on public forest lands is a complex issue of growing global importance. The provision of public recreation opportunities is part of the suite of ecological goods and services that must be considered by many forest managers. Effective access management is predicated on understanding the attitudes and perceptions of recreation users in order to predict and influence visitor behaviour and gauge the acceptance of new management strategies. Potential access management strategies vary given the nature of recreation activities and include: restricting the amount, type, and spatial distribution of use, visitor education, temporal restrictions and enhancing site durability. In this research we examined the views of recreation users on public lands in southwestern Alberta, Canada through implementation of an online survey (n = 945) with a focus on access management options. The results indicate a strong belief that the quality of the recreation experience is declining and that increased management and enforcement are required. More detailed analysis indicates that demographic and user-type variables strongly influence ideas about appropriate management. Forest managers need to engage with, understand, and respond to a wide variety of recreation user needs and preferences.展开更多
With the rapid development of automobile ownership and roadway network in China, there is more and more travel demand in the city of Beijing, China. Large commercial areas attract high volumes of traffic, which greatl...With the rapid development of automobile ownership and roadway network in China, there is more and more travel demand in the city of Beijing, China. Large commercial areas attract high volumes of traffic, which greatly impacts traffic movement on roadways, producing congestion and safety problems. What is more serious is that existing design of the parking lot, the location of access, layout of driveway, and passage of circulation are not desirable, causing potential conflicts and traffic delays. This paper mainly investigates the impact of the existing design of parking lot and layout of access and driveways at commercial areas around intersection in Beijing. The overall goal of this study is to use access management technologies to find out the measures for commercial area to improve roadway safety and operational efficiency. Some measures of improvements are proposed based on the analysis, including addition of right turn lanes, increase of driveway throat length and incorporation of traffic signs to guide on-site circulation. To accomplish the study objective, a total of 10 commercial areas around intersection were selected and some necessary data were collected at access points including traffic volume of each access and the frontage roadways during peak hours, access type, location, and spacing. The field investigations were conducted for 2 weekends for each area. Meanwhile, the peak hours were 10:00 to 12:00 a.m. on weekends. The data from field investigations show that the number and location of the access is different from place to place. Access driveway is closely located at the signalized intersection mostly. Other problems are also observed based on field investigation such as shortage of the access spacing. The result of this study can be a reference for traffic management on other similar areas in Beijing.展开更多
Conflicts are common phenomena in the field of traffic engineering, while are also the main cause of all the traffic problems. The vehicle access driveway of large shopping mall is often the conflict area of urban roa...Conflicts are common phenomena in the field of traffic engineering, while are also the main cause of all the traffic problems. The vehicle access driveway of large shopping mall is often the conflict area of urban roads, traffic engineers and city managers face a great challenge as to make the traffic enter and exit the shopping mall safely and or-derly. This paper studies the issues of access management of large shopping mall with a focus on Carrefour shopping mall in Shuangjin district, Beijing. This shopping mall attracts and generates lots of traffic during peak hours, those huge numbers of vehicles come in and out of the shopping mall through the access driveway, resulting in a lot of conflicts to the urban road traffic flow and deteriorating highly smooth movement of traffic on the urban roadway. The impacts of the existing design and layout of access driveway on surrounding traffic operation are also studied in this paper. Some countermeasure of improvements had proposed to decrease traffic conflicts and make sure that the traffic conditions get better off, all the improvement countermeasures are based on the access management principles. Results from this study can be a good reference on other similar driveways at large shopping mall areas.展开更多
In this paper, a theoretical analysis of Time Division Duplex-Code Division Multiple Access (TDD-CDMA) uplink capacity constraint is presented when employing the smart antenna techniques. The evaluation formulations o...In this paper, a theoretical analysis of Time Division Duplex-Code Division Multiple Access (TDD-CDMA) uplink capacity constraint is presented when employing the smart antenna techniques. The evaluation formulations of capacity and load for multi-services are proposed. In order to maximize the throughput, the objective of optimization is proposed, and an advanced uplink resource management algo-rithm is developed. The proposed algorithm based on the least interference admission control scheme focuses on the maximum throughput for the circuit switched multi-services. The simulation results show that the pro-posed strategy has a significant improvement in throughput when the optimum admission control threshold is set.展开更多
The Central Economic Working Conference of the CPC sets out an important mission for China’s economic development in 2007:"tak- ing energy conservation and protection of the ecological environment as the startin...The Central Economic Working Conference of the CPC sets out an important mission for China’s economic development in 2007:"tak- ing energy conservation and protection of the ecological environment as the starting point,actively promote optimization and upgrade of the industrial structure".展开更多
Global food security is a pressing issue that affects the stability and well-being of communities worldwide.While existing Internet of Things(IoT)enabled plant monitoring systems have made significant strides in agric...Global food security is a pressing issue that affects the stability and well-being of communities worldwide.While existing Internet of Things(IoT)enabled plant monitoring systems have made significant strides in agricultural monitoring,they often face limitations such as high power consumption,restricted mobility,complex deployment requirements,and inadequate security measures for data access.This paper introduces an enhanced IoT application for agricultural monitoring systems that address these critical shortcomings.Our system strategically combines power efficiency,portability,and secure access capabilities,assisting farmers in monitoring and tracking crop environmental conditions.The proposed system includes a remote camera that captures images of surrounding plants and a sensor module that regularly monitors various environmental factors,including temperature,humidity,and soil moisture.We implement power management strategies to minimize energy consumption compared to existing solutions.Unlike conventional systems,our implementation utilizes the Amazon Web Services(AWS)cloud platform for reliable data storage and processing while incorporating comprehensive security measures,including Two-Factor Authentication(2FA)and JSON Web Tokens(JWT),features often overlooked in current agricultural IoT solutions.Users can access this secure monitoring system via a developed Android application,providing convenient mobile access to the gathered plant data.We validate our system’s advantages by implementing it with two potted garlic plants on Okayama University’s rooftop.Our evaluation demonstrates high sensor reliabil-ity,with strong correlations between sensor readings and reference data,achieving determination coefficients(R2)of 0.979 for temperature and 0.750 for humidity measurements.The implemented power management strategies extend battery life to 10 days on a single charge,significantly outperforming existing systems that typically require daily recharging.Furthermore,our dual-layer security implementation utilizing 2FA and JWT successfully protects sensitive agricultural data from unauthorized access.展开更多
Motorcycle dependent cities have specific characteristics in terms of urban accessibility.A rapid increase in the number of motorcycles and other private motorized modes make transport problems more serious and cause ...Motorcycle dependent cities have specific characteristics in terms of urban accessibility.A rapid increase in the number of motorcycles and other private motorized modes make transport problems more serious and cause severe capacity problems for the infrastructure systems in these cities.Therefore,it is necessary to optimize the development of different modes to meet travel demand and to ensure accessibility in all urban areas.This paper aims to explore accessibility conditions in Ho Chi Minh City,a typical motorcycle dependent city in Vietnam.Understanding of accessibility could be the key element for urban planning in Ho Chi Minh City in particular and motorcycle dependent cities in general.Then,management measures for motorcycles and competitive modes will be proposed to improve the accessibility conditions and thus support sustainable urban transport development for motorcycle dependent cities.展开更多
基金Supported by the National Natural Science Foun-dation of China (60363001 ,60373087 ,90104005 ,60473023)
文摘The current multicast model provides no access control mechanism. Any host can send data directly to a multicast address or join a multicast group to become a member, which brings safety problems to multicast. In this paper, we present a new active multicast group access control mechanism that is founded on trust management. This structure can solve the problem that exists in multicast members' access control and distributing authorization of traditional IP multicast.
文摘Water scarcity is a major problem for Namibia and South Africa as both countries are classified as "water stressed", based on their per capita water availability which is below the threshold of 1,000-1,666 ma-person^-1.year^-1. Water provision in both countries has traditionally relied on supply-side sources, and the potential for expansion is becoming dim, making efforts towards demand management approaches more feasible. Findings show that CBM (community based management) systems of water points offer an alternative in terms of ownership and self-reliance based on institutional arrangements at community level. However, the CBM system involves some forms of payment for water access, and affordability has become a main challenge, to the extent that some governments are considering the reintroduction of water subsidies for poor rural communities in the near future.
基金the National Key Project Foundation of China (No. 2001BA201A0605) and partially supported by the State Key Lab for Mechanical Transmission..
文摘A new web product data management architecture is presented. The three-tier web architecture and Simple Object Access Protocol (SOAP) are combined to build the web-based product data management (PDM) system which includes three tiers: the user services tier, the business services tier, and the data services tier. The client service component uses the server-side technology, and Extensible Markup Language (XML) web service which uses SOAP as the communication protocol is chosen as the business service component. To illustrate how to build a web-based PDM system using the proposed architecture, a case PDM system which included three logical tires was built. To use the security and central management features of the database, a stored procedure was recommended in the data services tier. The business object was implemented as an XML web service so that client could use standard internet protocols to communicate with the business object from any platform. In order to satisfy users using all sorts of browser, the server-side technology and Microsoft ASP.NET was used to create the dynamic user interface.
文摘Objective To introduce the accession procedure and evaluation of PIC/S,and help relevant departments in China to understand the requirements of PIC/S in detail,and to promote the process of China’s entry into PIC/S.Methods The procedures and steps of joining PIC/S,the evaluation process of PIC/S,and the experience of several countries in joining PIC/S were introduced and analyzed,which could help the relevant personnel in China understand the specific contents.Results and Conclusion According to the requirements of PIC/S,it is necessary to establish a unified GMP quality management system.
文摘随着云计算的快速发展及其普及,企业的传统数据安全边界被打破,出现云资产管理混乱、越权、误操作等现象,对用户的信息安全产生巨大威胁。基于此,对目前云计算环境下身份认证和访问管理(identity and access management,IAM)的安全问题进行研究,提出结合内生安全思想,采取拟态防御手段构建出一种具有内生安全效应的拟态身份认证和访问管理(mimicry identity and access management,MIAM)体系架构方案,并对其进行详细描述。将该方案分别进行稳定性测试、系统性能测试以及系统安全性评估,实验数据表明,该方案具有可行性和安全性。
文摘Transcatheter aortic valve implantation(TAVI) using stent-based bioprostheses has recently emerged as a promising alternative to surgical valve replacement in selected patients. The main route for TAVI is retrograde access from the femoral artery using large sheaths(16-24 F). Vascular access complications are a clinically relevant issue in TAVI procedures since they are reported to occur in up to one fourth of patients and are strongly associated with adverse outcomes. In the present paper, we review the different types of vascular access site complications associated with transfemoral TAVI. Moreover, we discuss the possible optimal management strategies with particular attention to the relevance of early diagnosis and prompt treatment using endovascular techniques.
文摘Dynamic spectrum access technologies based on Cognitive Radio(CR) is under intensive research carried out by the wireless communication society and is expected to solve the problem of spectrum scarcity.However,most enabling technologies related to dynamic spectrum access are con-sidered individually.In this paper,we consider these key technologies jointly and introduce a new implementation scheme for a Dynamic Spectrum Access Network Based on Cognitive Radio(DSAN-BCR).We start with a flexible hardware platform for DSAN-BCR,as well as a flexible protocol structure that dominates the operation of DSAN-BCR.We then focus on the state of the art of key technologies such as spectrum sensing,spectrum resources management,dynamic spectrum access,and routing that are below the network layer in DSAN-BCR,as well as the development of technologies related to higher layers.Last but not the least,we analyze the challenges confronted by these men-tioned technologies in DSAN-BCR,and give the perspectives on the future development of these technologies.The DSAN-BCR introduced is expected to provide a system level guidance to alleviate the problem of spectrum scarcity.
基金Project(2012AA01A301-01)supported by the National High-Tech Research and Development Plan of ChinaProjects(61301148,61272061)supported by the National Natural Science Foundation of China+3 种基金Projects(20120161120019,2013016111002)supported by the Research Fund for the Doctoral Program of Higher Education of ChinaProjects(14JJ7023,10JJ5069)supported by the Natural Science Foundation of Hunan Province,ChinaProject(ISN12-05)supported by State Key Laboratory of Integrated Services Networks Open Foundation,ChinaProject(531107040276)supported by the Fundamental Research Funds for the Central Universities,China
文摘Abstract: Two-tier heterogeneous networks (HetNets), where the current cellular networks, i.e., macrocells, are overlapped with a large number of randomly distributed femtocells, can potentially bring significant benefits to spectral utilization and system capacity. The interference management and access control for open and closed femtocells in two-tier HetNets were focused. The contributions consist of two parts. Firstly, in order to reduce the uplink interference caused by MUEs (macrocell user equipments) at closed femtocells, an incentive mechanism to implement interference mitigation was proposed. It encourages femtoeells that work with closed-subscriber-group (CSG) to allow the interfering MUEs access in but only via uplink, which can reduce the interference significantly and also benefit the marco-tier. The interference issue was then studied in open-subscriber-group (OSG) femtocells from the perspective of handover and mobility prediction. Inbound handover provides an alternative solution for open femtocells when interference turns up, while this accompanies with PCI (physical cell identity) confusion during inbound handover. To reduce the PCI confusion, a dynamic PCI allocation scheme was proposed, by which the high handin femtocells have the dedicated PCI while the others share the reuse PCIs. A Markov chain based mobility prediction algorithm was designed to decide whether the femtoeell status is with high handover requests. Numerical analysis reveals that the UL interference is managed well for the CSG femtocell and the PCI confusion issue is mitigated greatly in OSG femtocell compared to the conventional approaches.
基金Supported by the National Tenth Five-rear Planfor Scientific and Technological Development of China (413160501)the National Natural Science Foundation of China (50477038)
文摘PMI (privilege management infrastructure) is used to perform access control to resource in an E-commerce or E-government system. With the ever-increasing need for secure transaction, the need for systems that offer a wide variety of QoS (quality-of-service) features is also growing. In order to improve the QoS of PMI system, a cache based on RBAC (Role-based Access control) and trust is proposed. Our system is realized based on Web service. How to design the cache based on RBAC and trust in the access control model is deseribed in detail. The algorithm to query role permission in cache and to add records in cache is dealt with. The policy to update cache is introduced also.
基金supported in part by the NRF(National Research Foundation of Korea)Grant(No.2019R1A2C1009275)by the Institute of Information&communications Technology Planning&Evaluation(IITP)grant funded by theKorean government(MSIT)(No.2021-0-02068,Artificial Intelligence Innovation Hub).
文摘Due to the recent trend of software intelligence in the Fourth Industrial Revolution,deep learning has become a mainstream workload for modern computer systems.Since the data size of deep learning increasingly grows,managing the limited memory capacity efficiently for deep learning workloads becomes important.In this paper,we analyze memory accesses in deep learning workloads and find out some unique characteristics differentiated from traditional workloads.First,when comparing instruction and data accesses,data access accounts for 96%–99%of total memory accesses in deep learning workloads,which is quite different from traditional workloads.Second,when comparing read and write accesses,write access dominates,accounting for 64%–80%of total memory accesses.Third,although write access makes up the majority of memory accesses,it shows a low access bias of 0.3 in the Zipf parameter.Fourth,in predicting re-access,recency is important in read access,but frequency provides more accurate information in write access.Based on these observations,we introduce a Non-Volatile Random Access Memory(NVRAM)-accelerated memory architecture for deep learning workloads,and present a new memory management policy for this architecture.By considering the memory access characteristics of deep learning workloads,the proposed policy improves memory performance by 64.3%on average compared to the CLOCK policy.
文摘Management of recreational access on public forest lands is a complex issue of growing global importance. The provision of public recreation opportunities is part of the suite of ecological goods and services that must be considered by many forest managers. Effective access management is predicated on understanding the attitudes and perceptions of recreation users in order to predict and influence visitor behaviour and gauge the acceptance of new management strategies. Potential access management strategies vary given the nature of recreation activities and include: restricting the amount, type, and spatial distribution of use, visitor education, temporal restrictions and enhancing site durability. In this research we examined the views of recreation users on public lands in southwestern Alberta, Canada through implementation of an online survey (n = 945) with a focus on access management options. The results indicate a strong belief that the quality of the recreation experience is declining and that increased management and enforcement are required. More detailed analysis indicates that demographic and user-type variables strongly influence ideas about appropriate management. Forest managers need to engage with, understand, and respond to a wide variety of recreation user needs and preferences.
文摘With the rapid development of automobile ownership and roadway network in China, there is more and more travel demand in the city of Beijing, China. Large commercial areas attract high volumes of traffic, which greatly impacts traffic movement on roadways, producing congestion and safety problems. What is more serious is that existing design of the parking lot, the location of access, layout of driveway, and passage of circulation are not desirable, causing potential conflicts and traffic delays. This paper mainly investigates the impact of the existing design of parking lot and layout of access and driveways at commercial areas around intersection in Beijing. The overall goal of this study is to use access management technologies to find out the measures for commercial area to improve roadway safety and operational efficiency. Some measures of improvements are proposed based on the analysis, including addition of right turn lanes, increase of driveway throat length and incorporation of traffic signs to guide on-site circulation. To accomplish the study objective, a total of 10 commercial areas around intersection were selected and some necessary data were collected at access points including traffic volume of each access and the frontage roadways during peak hours, access type, location, and spacing. The field investigations were conducted for 2 weekends for each area. Meanwhile, the peak hours were 10:00 to 12:00 a.m. on weekends. The data from field investigations show that the number and location of the access is different from place to place. Access driveway is closely located at the signalized intersection mostly. Other problems are also observed based on field investigation such as shortage of the access spacing. The result of this study can be a reference for traffic management on other similar areas in Beijing.
文摘Conflicts are common phenomena in the field of traffic engineering, while are also the main cause of all the traffic problems. The vehicle access driveway of large shopping mall is often the conflict area of urban roads, traffic engineers and city managers face a great challenge as to make the traffic enter and exit the shopping mall safely and or-derly. This paper studies the issues of access management of large shopping mall with a focus on Carrefour shopping mall in Shuangjin district, Beijing. This shopping mall attracts and generates lots of traffic during peak hours, those huge numbers of vehicles come in and out of the shopping mall through the access driveway, resulting in a lot of conflicts to the urban road traffic flow and deteriorating highly smooth movement of traffic on the urban roadway. The impacts of the existing design and layout of access driveway on surrounding traffic operation are also studied in this paper. Some countermeasure of improvements had proposed to decrease traffic conflicts and make sure that the traffic conditions get better off, all the improvement countermeasures are based on the access management principles. Results from this study can be a good reference on other similar driveways at large shopping mall areas.
基金Sponsored by the National Advanced Technologies Researching and Developing Programs (No.2004AA123160).
文摘In this paper, a theoretical analysis of Time Division Duplex-Code Division Multiple Access (TDD-CDMA) uplink capacity constraint is presented when employing the smart antenna techniques. The evaluation formulations of capacity and load for multi-services are proposed. In order to maximize the throughput, the objective of optimization is proposed, and an advanced uplink resource management algo-rithm is developed. The proposed algorithm based on the least interference admission control scheme focuses on the maximum throughput for the circuit switched multi-services. The simulation results show that the pro-posed strategy has a significant improvement in throughput when the optimum admission control threshold is set.
文摘The Central Economic Working Conference of the CPC sets out an important mission for China’s economic development in 2007:"tak- ing energy conservation and protection of the ecological environment as the starting point,actively promote optimization and upgrade of the industrial structure".
基金supported by the budget of GIC project at Okayama University.
文摘Global food security is a pressing issue that affects the stability and well-being of communities worldwide.While existing Internet of Things(IoT)enabled plant monitoring systems have made significant strides in agricultural monitoring,they often face limitations such as high power consumption,restricted mobility,complex deployment requirements,and inadequate security measures for data access.This paper introduces an enhanced IoT application for agricultural monitoring systems that address these critical shortcomings.Our system strategically combines power efficiency,portability,and secure access capabilities,assisting farmers in monitoring and tracking crop environmental conditions.The proposed system includes a remote camera that captures images of surrounding plants and a sensor module that regularly monitors various environmental factors,including temperature,humidity,and soil moisture.We implement power management strategies to minimize energy consumption compared to existing solutions.Unlike conventional systems,our implementation utilizes the Amazon Web Services(AWS)cloud platform for reliable data storage and processing while incorporating comprehensive security measures,including Two-Factor Authentication(2FA)and JSON Web Tokens(JWT),features often overlooked in current agricultural IoT solutions.Users can access this secure monitoring system via a developed Android application,providing convenient mobile access to the gathered plant data.We validate our system’s advantages by implementing it with two potted garlic plants on Okayama University’s rooftop.Our evaluation demonstrates high sensor reliabil-ity,with strong correlations between sensor readings and reference data,achieving determination coefficients(R2)of 0.979 for temperature and 0.750 for humidity measurements.The implemented power management strategies extend battery life to 10 days on a single charge,significantly outperforming existing systems that typically require daily recharging.Furthermore,our dual-layer security implementation utilizing 2FA and JWT successfully protects sensitive agricultural data from unauthorized access.
文摘Motorcycle dependent cities have specific characteristics in terms of urban accessibility.A rapid increase in the number of motorcycles and other private motorized modes make transport problems more serious and cause severe capacity problems for the infrastructure systems in these cities.Therefore,it is necessary to optimize the development of different modes to meet travel demand and to ensure accessibility in all urban areas.This paper aims to explore accessibility conditions in Ho Chi Minh City,a typical motorcycle dependent city in Vietnam.Understanding of accessibility could be the key element for urban planning in Ho Chi Minh City in particular and motorcycle dependent cities in general.Then,management measures for motorcycles and competitive modes will be proposed to improve the accessibility conditions and thus support sustainable urban transport development for motorcycle dependent cities.