Pub Date : 2004-04-19DOI: 10.1109/CCNC.2004.1286888
Xiumei Yang, D. Yuan, Piming Ma, M. Jiang
A new scheme is proposed about how to make use of the unequal error protection (UEP) property of irregular low-density parity-check (LDPC) codes. By means of the construction of a weight-increasing parity-check matrix and systematic encoding, the mapping between the important information data and the elite bits of an irregular LDPC code becomes traceable and tractable. Thus, the inherent UEP property of irregular LDPC codes is not the theoretical interest any more. The proposed scheme makes it practical to implement UEP in system applications. Taking an irregular LDPC code with code length 10000 and code rate one half as an example, simulation results are presented over AWGN channels. The validity of the proposed scheme is verified by simulation.
{"title":"New research on unequal error protection (UEP) property of irregular LDPC codes","authors":"Xiumei Yang, D. Yuan, Piming Ma, M. Jiang","doi":"10.1109/CCNC.2004.1286888","DOIUrl":"https://doi.org/10.1109/CCNC.2004.1286888","url":null,"abstract":"A new scheme is proposed about how to make use of the unequal error protection (UEP) property of irregular low-density parity-check (LDPC) codes. By means of the construction of a weight-increasing parity-check matrix and systematic encoding, the mapping between the important information data and the elite bits of an irregular LDPC code becomes traceable and tractable. Thus, the inherent UEP property of irregular LDPC codes is not the theoretical interest any more. The proposed scheme makes it practical to implement UEP in system applications. Taking an irregular LDPC code with code length 10000 and code rate one half as an example, simulation results are presented over AWGN channels. The validity of the proposed scheme is verified by simulation.","PeriodicalId":316094,"journal":{"name":"First IEEE Consumer Communications and Networking Conference, 2004. CCNC 2004.","volume":"16 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2004-04-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"126969740","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2004-04-19DOI: 10.1109/CCNC.2004.1286896
A. Tsutsui, Hiroyuki Maeomiti, R. Kawamura, K. Yata
In today's Internet, which includes diverse and complex network technologies and services, it is difficult to achieve 'comfortable communication' that satisfies network users from the viewpoint of aspects such as communication usability, availability, quality and safety. To alleviate these problems and make communication a comfortable experience for users, we have developed a middleware named communication service concierge (CSC). CSC focuses on communication dataflow and coordinates various resources affecting the behavior of the flow, such as network applications, protocols, network devices and computing equipment. These elements can be scattered throughout the end-to-end communication link of the dataflow. CSC provides a distributed communication control framework, which improves user satisfaction on the basis of agent computing using configurable and downloadable software components. The paper briefly describes the design concept and basic architecture of CSC, as well as two prototype applications for it that are associated with home networking and mobile computing. These are the most effective ways in which CSC helps users to achieve more comfortable communication.
{"title":"An adaptive communication middleware for network service coordination","authors":"A. Tsutsui, Hiroyuki Maeomiti, R. Kawamura, K. Yata","doi":"10.1109/CCNC.2004.1286896","DOIUrl":"https://doi.org/10.1109/CCNC.2004.1286896","url":null,"abstract":"In today's Internet, which includes diverse and complex network technologies and services, it is difficult to achieve 'comfortable communication' that satisfies network users from the viewpoint of aspects such as communication usability, availability, quality and safety. To alleviate these problems and make communication a comfortable experience for users, we have developed a middleware named communication service concierge (CSC). CSC focuses on communication dataflow and coordinates various resources affecting the behavior of the flow, such as network applications, protocols, network devices and computing equipment. These elements can be scattered throughout the end-to-end communication link of the dataflow. CSC provides a distributed communication control framework, which improves user satisfaction on the basis of agent computing using configurable and downloadable software components. The paper briefly describes the design concept and basic architecture of CSC, as well as two prototype applications for it that are associated with home networking and mobile computing. These are the most effective ways in which CSC helps users to achieve more comfortable communication.","PeriodicalId":316094,"journal":{"name":"First IEEE Consumer Communications and Networking Conference, 2004. CCNC 2004.","volume":"11 3 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2004-04-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"124612470","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2004-04-19DOI: 10.1109/CCNC.2004.1286916
M. Furini, Lorenzo Alboresi
The large usage of multimedia portable devices has contributed to a rapid increase in the demand for multimedia entertainment services. We focus on the karaoke service: several systems have been proposed but they are too difficult to be used directly over audio devices. Conversely, we propose a very simple approach to providing a karaoke-like service over any audio device that can play out mp3 files. Our approach is essentially new, as no additional files, beyond the mp3 file, are necessary. A simple description language has been designed to characterize audio-text timing synchronizations, which are transparently stored inside the mp3 file. The effectiveness of our approach is proved through a developed Java mp3 player. The simplicity of our approach along with Java portability allow a straightforward use of our player over any OS and over any audio device that supports Java applications.
{"title":"Audio-text synchronization inside mp3 files: a new approach and its implementation","authors":"M. Furini, Lorenzo Alboresi","doi":"10.1109/CCNC.2004.1286916","DOIUrl":"https://doi.org/10.1109/CCNC.2004.1286916","url":null,"abstract":"The large usage of multimedia portable devices has contributed to a rapid increase in the demand for multimedia entertainment services. We focus on the karaoke service: several systems have been proposed but they are too difficult to be used directly over audio devices. Conversely, we propose a very simple approach to providing a karaoke-like service over any audio device that can play out mp3 files. Our approach is essentially new, as no additional files, beyond the mp3 file, are necessary. A simple description language has been designed to characterize audio-text timing synchronizations, which are transparently stored inside the mp3 file. The effectiveness of our approach is proved through a developed Java mp3 player. The simplicity of our approach along with Java portability allow a straightforward use of our player over any OS and over any audio device that supports Java applications.","PeriodicalId":316094,"journal":{"name":"First IEEE Consumer Communications and Networking Conference, 2004. CCNC 2004.","volume":"39 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2004-04-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"125120108","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2004-04-19DOI: 10.1109/CCNC.2004.1286847
Dongk-Kyun Kim, Ki-Il Kim, Kap-Dong Kim, I. Whang, Sang-Ha Kim
Various ALM (application layer multicast) mechanisms have been suggested to remove the barriers that block deployment of IP multicast. However, most ALM mechanisms do not consider the host group model, which is not a problematic portion, but advantageous feature of traditional IP multicast in terms of scalability, robustness, security, and transparency. Furthermore, those mechanisms build an overlay multicast network for data delivery mostly based on a simple measurement, with a few metrics, without directly considering the IP network topology. Thus, they might suffer some inefficiency, such as long join delay and large control overhead. We propose a scheme to take advantages of both IP multicast and ALM, based on two principal design factors. By adopting the host group model, our scheme can inherently acquire network topology information used to get rid of application level routing inefficiency, and to gain additional efficiency for many group members. Also, we exploit topology-awareness to reduce join delay and localize group members so that controls for setting up and maintaining overlay networks can be limited in a domain. Overall network performance is enhanced with our scheme by building an overlay network based on performance factors associated with network characteristics using a hierarchical structure.
{"title":"Scheme for scalable ALM architecture based on topology-awareness","authors":"Dongk-Kyun Kim, Ki-Il Kim, Kap-Dong Kim, I. Whang, Sang-Ha Kim","doi":"10.1109/CCNC.2004.1286847","DOIUrl":"https://doi.org/10.1109/CCNC.2004.1286847","url":null,"abstract":"Various ALM (application layer multicast) mechanisms have been suggested to remove the barriers that block deployment of IP multicast. However, most ALM mechanisms do not consider the host group model, which is not a problematic portion, but advantageous feature of traditional IP multicast in terms of scalability, robustness, security, and transparency. Furthermore, those mechanisms build an overlay multicast network for data delivery mostly based on a simple measurement, with a few metrics, without directly considering the IP network topology. Thus, they might suffer some inefficiency, such as long join delay and large control overhead. We propose a scheme to take advantages of both IP multicast and ALM, based on two principal design factors. By adopting the host group model, our scheme can inherently acquire network topology information used to get rid of application level routing inefficiency, and to gain additional efficiency for many group members. Also, we exploit topology-awareness to reduce join delay and localize group members so that controls for setting up and maintaining overlay networks can be limited in a domain. Overall network performance is enhanced with our scheme by building an overlay network based on performance factors associated with network characteristics using a hierarchical structure.","PeriodicalId":316094,"journal":{"name":"First IEEE Consumer Communications and Networking Conference, 2004. CCNC 2004.","volume":"29 6 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2004-04-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"125695026","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2004-04-19DOI: 10.1109/CCNC.2004.1286928
H. Kunczier, H. Anegg
Mobile location based applications are in the first place designed for urban areas where providers find a high density of customers. Exactly in these environments, conventional trilateration location techniques often lack performance due to multipath propagation. We present results from a localization related usability study with a fully implemented mobile tourist guide, called LoL@ (local location assistant) in the City of Vienna. We show that GPS or cell ID based localization techniques are not sufficient to achieve user satisfaction. Based on these results, we introduce a new localization approach utilizing Bayesian networks to improve localization accuracy for mobile location based services in urban areas. The method uses power level measurements at the mobile station and can be generalized to use any location dependent parameters. The achieved accuracy, based on measurements in the City of Vienna, is less than 20 meters in 67% of all estimates, and about 50 meters in 90% of all estimates. This is adequate for most location applications, including emergency services.
{"title":"Enhanced cell ID based terminal location for urban area location based applications","authors":"H. Kunczier, H. Anegg","doi":"10.1109/CCNC.2004.1286928","DOIUrl":"https://doi.org/10.1109/CCNC.2004.1286928","url":null,"abstract":"Mobile location based applications are in the first place designed for urban areas where providers find a high density of customers. Exactly in these environments, conventional trilateration location techniques often lack performance due to multipath propagation. We present results from a localization related usability study with a fully implemented mobile tourist guide, called LoL@ (local location assistant) in the City of Vienna. We show that GPS or cell ID based localization techniques are not sufficient to achieve user satisfaction. Based on these results, we introduce a new localization approach utilizing Bayesian networks to improve localization accuracy for mobile location based services in urban areas. The method uses power level measurements at the mobile station and can be generalized to use any location dependent parameters. The achieved accuracy, based on measurements in the City of Vienna, is less than 20 meters in 67% of all estimates, and about 50 meters in 90% of all estimates. This is adequate for most location applications, including emergency services.","PeriodicalId":316094,"journal":{"name":"First IEEE Consumer Communications and Networking Conference, 2004. CCNC 2004.","volume":"7 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2004-04-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"128750181","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2004-04-19DOI: 10.1109/CCNC.2004.1286832
Ping Ding, J. Holliday, Aslihan Celik
802.1x is a security protocol based on the frame structure of 802.11. It attempts to provide strong authentication, access control, and WEP (wired equivalent privacy) key management for wireless LANs. Unfortunately, 802.1x misses its goals in access control denial-of-service attacks. Currently, there are no IEEE approved ways to solve this security hole. We propose a central manager, not only to take the responsibility of an authentication server, but also to add functionality to prevent denial of service attacks. We also analyze how the 802.11 MAC layer protocol works with our solution.
{"title":"Improving the security of wireless LANs by managing 802.1x disassociation","authors":"Ping Ding, J. Holliday, Aslihan Celik","doi":"10.1109/CCNC.2004.1286832","DOIUrl":"https://doi.org/10.1109/CCNC.2004.1286832","url":null,"abstract":"802.1x is a security protocol based on the frame structure of 802.11. It attempts to provide strong authentication, access control, and WEP (wired equivalent privacy) key management for wireless LANs. Unfortunately, 802.1x misses its goals in access control denial-of-service attacks. Currently, there are no IEEE approved ways to solve this security hole. We propose a central manager, not only to take the responsibility of an authentication server, but also to add functionality to prevent denial of service attacks. We also analyze how the 802.11 MAC layer protocol works with our solution.","PeriodicalId":316094,"journal":{"name":"First IEEE Consumer Communications and Networking Conference, 2004. CCNC 2004.","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2004-04-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"130990165","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2004-04-19DOI: 10.1109/CCNC.2004.1286840
Masayuki Kumazawa, Taisuke Matsumoto, Shinkichi Ikeda, M. Funabiki, H. Kobayashi, T. Kawahara
Personal area networks (PANs) are networks in which portable devices carried by a user are connected to each other by wireless interfaces. Mobile personal area networks (MPANs) allow a PAN to be mobile, enabling seamless Internet access even when the user is moving. A PAN router has a wireless access interface and connects the devices in the MPAN to the Internet. There might be two or more MPAN routers in an MPAN and it is necessary for the MPAN router most suitable for the location and/or situation to be in operation. For example, if the MPAN router currently operating as the default router fails, another available MPAN router should start to operate as the default, or an MPAN router might be selected from those available according to QoS. We propose methods for the switching and selection of MPAN routers. We show by experiment that they enable fast switching and selection of the MPAN router most suitable for various QoS.
{"title":"Router selection for moving networks","authors":"Masayuki Kumazawa, Taisuke Matsumoto, Shinkichi Ikeda, M. Funabiki, H. Kobayashi, T. Kawahara","doi":"10.1109/CCNC.2004.1286840","DOIUrl":"https://doi.org/10.1109/CCNC.2004.1286840","url":null,"abstract":"Personal area networks (PANs) are networks in which portable devices carried by a user are connected to each other by wireless interfaces. Mobile personal area networks (MPANs) allow a PAN to be mobile, enabling seamless Internet access even when the user is moving. A PAN router has a wireless access interface and connects the devices in the MPAN to the Internet. There might be two or more MPAN routers in an MPAN and it is necessary for the MPAN router most suitable for the location and/or situation to be in operation. For example, if the MPAN router currently operating as the default router fails, another available MPAN router should start to operate as the default, or an MPAN router might be selected from those available according to QoS. We propose methods for the switching and selection of MPAN routers. We show by experiment that they enable fast switching and selection of the MPAN router most suitable for various QoS.","PeriodicalId":316094,"journal":{"name":"First IEEE Consumer Communications and Networking Conference, 2004. CCNC 2004.","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2004-04-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"133270525","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2004-04-19DOI: 10.1109/CCNC.2004.1286861
H. Aouad, A. Ibrahim, S. Tohmé
The paper characterizes the statistical distribution of the interarrival packet time of UTRAN traffic at the SAP level of the MAC layer. We analyze a simulated traffic trace of UMTS networks to characterize the nature of the aggregated flows. We chose MMPP-2 (Markov modulated Poisson process) to model the packet interarrival time.
{"title":"UTRAN traffic parameters estimation","authors":"H. Aouad, A. Ibrahim, S. Tohmé","doi":"10.1109/CCNC.2004.1286861","DOIUrl":"https://doi.org/10.1109/CCNC.2004.1286861","url":null,"abstract":"The paper characterizes the statistical distribution of the interarrival packet time of UTRAN traffic at the SAP level of the MAC layer. We analyze a simulated traffic trace of UMTS networks to characterize the nature of the aggregated flows. We chose MMPP-2 (Markov modulated Poisson process) to model the packet interarrival time.","PeriodicalId":316094,"journal":{"name":"First IEEE Consumer Communications and Networking Conference, 2004. CCNC 2004.","volume":"21 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2004-04-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"133410772","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2004-04-19DOI: 10.1109/CCNC.2004.1286914
David C. Chu, Clement Song, Bei Zhang, M. Humphrey
The compact, mobile device, such as the PocketPC, is often regarded as little more than a handy, smaller "portal" by which to access information kept on larger back-end machines such as exchange servers and WWW servers. However, the true value of the device may ultimately result from more sophisticated approaches by which the device can fully recognize and change its behavior based on its context, such as location, remaining battery life, available networking, and user preferences. We present "UVa Bus.NET", a testbed at the University of Virginia for developing and evaluating general, context-aware, mobile solutions. We use .NET, .NET Compact Framework, GPS-enabled devices, and wireless networking inside buildings to notify students and professors of impending appointments and class meetings, give directions to their next appointment, and even direct them to the real-time location of the most appropriate bus to catch. The longer-term goals of UVa Bus.NET are also presented: to provide a more predictable experience to mobile device users by hiding and otherwise managing resource limitations.
{"title":"UVa Bus.NET: enhancing user experiences on smart devices through context-aware computing","authors":"David C. Chu, Clement Song, Bei Zhang, M. Humphrey","doi":"10.1109/CCNC.2004.1286914","DOIUrl":"https://doi.org/10.1109/CCNC.2004.1286914","url":null,"abstract":"The compact, mobile device, such as the PocketPC, is often regarded as little more than a handy, smaller \"portal\" by which to access information kept on larger back-end machines such as exchange servers and WWW servers. However, the true value of the device may ultimately result from more sophisticated approaches by which the device can fully recognize and change its behavior based on its context, such as location, remaining battery life, available networking, and user preferences. We present \"UVa Bus.NET\", a testbed at the University of Virginia for developing and evaluating general, context-aware, mobile solutions. We use .NET, .NET Compact Framework, GPS-enabled devices, and wireless networking inside buildings to notify students and professors of impending appointments and class meetings, give directions to their next appointment, and even direct them to the real-time location of the most appropriate bus to catch. The longer-term goals of UVa Bus.NET are also presented: to provide a more predictable experience to mobile device users by hiding and otherwise managing resource limitations.","PeriodicalId":316094,"journal":{"name":"First IEEE Consumer Communications and Networking Conference, 2004. CCNC 2004.","volume":"14 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2004-04-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"133732892","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2004-04-19DOI: 10.1109/CCNC.2004.1286873
G. Papadimitriou
A new medium access control protocol for broadcast LANs, which is capable of achieving a high performance under bursty traffic conditions, is introduced. According to the proposed protocol, the network stations are separated into groups. All the groups are granted permission to transmit in a round-robin fashion. The main objective of the grouping algorithm is to have exactly one ready station in each group. In this way, idle slots and collisions are minimized and a nearly optimal throughput-delay performance is achieved. The grouping of stations is dynamically modified at each time slot according to the network feedback information. Due to the dynamic nature of the grouping algorithm, the protocol is capable of being adapted to the sharp changes of the stations' traffic.
{"title":"AGP: a self-adaptive MAC protocol for broadcast LANs with bursty traffic","authors":"G. Papadimitriou","doi":"10.1109/CCNC.2004.1286873","DOIUrl":"https://doi.org/10.1109/CCNC.2004.1286873","url":null,"abstract":"A new medium access control protocol for broadcast LANs, which is capable of achieving a high performance under bursty traffic conditions, is introduced. According to the proposed protocol, the network stations are separated into groups. All the groups are granted permission to transmit in a round-robin fashion. The main objective of the grouping algorithm is to have exactly one ready station in each group. In this way, idle slots and collisions are minimized and a nearly optimal throughput-delay performance is achieved. The grouping of stations is dynamically modified at each time slot according to the network feedback information. Due to the dynamic nature of the grouping algorithm, the protocol is capable of being adapted to the sharp changes of the stations' traffic.","PeriodicalId":316094,"journal":{"name":"First IEEE Consumer Communications and Networking Conference, 2004. CCNC 2004.","volume":"83 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2004-04-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"129840667","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
京公网安备 11010802042870号
京ICP备2023020795号-1
扫码关注我们
求助内容：
应助结果提醒方式：