Development of domestic and international computer forensics

With the increasing of computer crime, instant emergence of new digital product, new computer technology and computer forensics technology is promoted, developed constantly. This paper described basic information/content of computer forensics, and elaborated the development of current computer forensics at domestic and overseas market. The trends of computer forensics are pointed out and recent hot topics of research are introduced. © 2011 IEEE.published_or_final_versionThe 7th International Conference on Intelligent Information Hiding and Multimedia Signal Processing (IIH-MSP 2011), Dalian, China, 14-16 October 2011. In Proceedings of the 7th IIH-MSP, 2011, p. 388-39

Cloud-based data-intensive framework towards fault diagnosis in large-scale petrochemical plants

Industrial Wireless Sensor Networks (IWSNs) are expected to offer promising monitoring solutions to meet the demands of monitoring applications for fault diagnosis in large-scale petrochemical plants, however, involves heterogeneity and Big Data problems due to large amounts of sensor data with high volume and velocity. Cloud Computing is an outstanding approach which provides a flexible platform to support the addressing of such heterogeneous and data-intensive problems with massive computing, storage, and data-based services. In this paper, we propose a Cloud-based Data-intensive Framework (CDF) for on-line equipment fault diagnosis system that facilitates the integration and processing of mass sensor data generated from Industrial Sensing Ecosystem (ISE). ISE enables data collection of interest with topic-specific industrial monitoring systems. Moreover, this approach contributes the establishment of on-line fault diagnosis monitoring system with sensor streaming computing and storage paradigms based on Hadoop as a key to the complex problems. Finally, we present a practical illustration referred to this framework serving equipment fault diagnosis systems with the ISE

Asymmetric Peer Influence in Smartphone Adoption in a Large Mobile Network

Understanding adoption patterns of smartphones is of vital importance to telecommunication managers in today’s highly dynamic mobile markets. In this paper, we leverage the network structure and specific position of each individual in the social network to account for and measure the potential heterogeneous role of peer influence in the adoption of the iPhone 3G. We introduce the idea of coreperiphery as a meso-level organizational principle to study the social network, which complements the use of centrality measures derived from either global network properties (macro-level) or from each individual\u27s local social neighbourhood (micro-level). Using millions of call detailed records from a mobile network operator in one country for a period of eleven months, we identify overlapping social communities as well as core and periphery individuals in the network. Our empirical analysis shows that core users exert more influence on periphery users than vice versa. Our findings provide important insights to help identify influential members in the social network, which is potentially useful to design optimal targeting strategies to improve current network-based marketing practices

모바일 소셜네트워크에서 사용자간 기회적인 공유기반트래픽 오프로딩

학위논문 (박사)-- 서울대학교 대학원 : 전기·컴퓨터공학부, 2013. 8. 최양희.최근 모바일 트래픽의 빠른 증가는 이동통신 사업자에게 심각한 문제가 되고 있다. 이러한 문제를 해결하기 위해 단거리 통신 기술 및 모바일 소셜 네트워크 등을 이용하여 사용자간 직접 데이터를 주고 받는 오프로딩 기법을 사용하는 것에 대한 연구가 이루어지고 있다. 본 논문에서는 사용자간 직접 통신을 통한 효율적인 콘텐츠 공유 및 오프로딩 기법을 제안하고자 한다. 첫번째 연구로, 모바일 소셜 네트워크에서 사용자간 직접 전송기회를 활용해 데이터를 공유하는 모바일 트래픽 오프로딩의 핵심 기술인 TOSS를 제안 하였다. TOSS에서는 셀룰러 네트워크에서 급속히 증가하고 있는 트래픽으로 인한 네트워크 과부하를 경감시키기 위해 온라인 소셜 네트워크에서 사용자의 연결성 및 오프라인 네트워크에서 사용자의 이동성을 고려하여 콘텐츠를 전달할 사용자를 결정하고 블루투스나 와이파이 다이렉트 등의 기술을 이용해 콘텐츠를 직접 전달 하였다. 또한 소셜네트워크 서비스 사용자의 서로 다른 콘텐츠 접근 패턴, 즉 각 사용자가 콘텐츠 생성으로부터 오프로딩을 위해 콘텐츠에 접근하기까지의 시간을 고려 하였다. 본 연구에서는 이러한 요건을 고려하여 트래픽 오프로딩과 콘텐츠 확산을 모델링하고 분석 하였다. 모바일 소셜 네트워크의 데이타 셋을 기반으로 분석 결과에서 TOSS는 모든 사용자의 딜레이 요구조건을 만족시키면서 최대 86.5의 셀룰러 트래픽을 경감시키는 것을 보였다. 두번째의 연구에서는 모바일 네트워크에서 멀티셀을 고려하여 콘텐츠를 배포하는 프레임워크에 대한 연구를 진행 하였다. 해당 프레임워크에서 콘텐츠는 셀룰러 링크와 모바일 사용자간 로컬 링크를 통해 푸시-공유 기반의 통신으로 전달 되였다. 이러한 기법을 바탕으로 multi-compartment 모델을 이용하여 셀 간 핸드오버 및 콘텐츠 전달을 모델링 및 분석하고, 콘텐츠 전달 딜레이와 에너지 소모 사이의 trade-off를 수학적인 최적화 기법을 사용하여 해결 하였다. 본 논문에서는 이와 같이 기존의 측정 연구에 기반한 trace-driven 분석, 모델링 및 시스템 최적화에 대한 연구를 통해 모바일 소셜 네트워크에서 사용자간 직접 전송을 통한 오프로딩 기법이 고효율적임을 보였다. 또한 본 논문은 제안된 기법의 상용화 전망 및 이를 위한 이슈들에 대한 논의도 포함 하였다.The fast increasing traffic demand becomes a serious concern of mobile network operators. To solve this traffic explosion problem, there have been efforts to offload the traffic from cellular links to local short-range communications among mobile users that are moving around and forming mobile social networks. In my thesis, I mainly focus on the user-to-user opportunistic sharing and try to elaborate its effectiveness and efficiency for to offload mobile traffic. In the first work, I propose the Traffic Offloading assisted by Social network services via opportunistic Sharing in mobile social networks, TOSS. In TOSS, initially a subset of mobile users are selected as initial seeds depending on their content spreading impact in online social network services (SNSs) and their mobility patterns in offline mobile social networks (MSNs). Then users share the content via opportunistic local connectivity (e.g., Bluetooth, Wi-Fi Direct) with each other. Due to the distinct access patterns of individual SNS users, TOSS further exploits the user-dependent access delay between the content generation time and each user's access time for the purpose of traffic offloading. I model and analyze process of the traffic offloading and content spreading by taking into account various options in linking SNS and MSN data sets. The trace-driven evaluation shows that TOSS can reduce up to 86.5% of the cellular traffic while satisfying the access delay requirements of all users. In the second work, I focus on the analytical research on Push-Share framework for content disseminating in mobile networks. One content is firstly pushed the to a subset of subscribers via cellular links, and mobile users spread the content via opportunistic local connectivity. I theoretically model and analyze how the content can be disseminated, where handovers are modeled based on the multi-compartment model. I also formulate the mathematical optimization framework, by which the trade-off between the dissemination delay and the energy cost is explored. Based on the measurement study, trace-driven analysis, theoretical modeling and system optimization in above papers, the traffic offloading by user-to-user opportunistic sharing in mobile social networks is proved to be effective and efficient. Additionally, further discussions on the practical deployment, future vision, and open issues are discussed as well.Abstract i I. Introduction 1 II. RelatedWork 7 2.1 Opportunistic Sharing in DTNs/MSNs 7 2.2 Mobile Traffic Offloading 9 2.3 Information/Content Spreading in SNSs 10 III. TOSS 13 3.1 Framework Details 13 3.1.1 Preliminaries 13 3.1.2 Spreading Impact in the Online SNS 16 3.1.3 Access Delays of Users in the SNS 18 3.1.4 Mobility Impact in the Offline MSN 21 3.2 System Optimization 25 3.3 Trace-Driven Measurement 26 3.3.1 Measurement of the Online SNS 26 3.3.2 Measurement of Offline MSNs, λi j and IM 33 3.3.3 Content Obtaining Delays 36 3.3.4 How C Impacts the Obtaining Delay 38 3.4 Performance Evaluation 39 3.4.1 How C Impacts the Total Access Utility 39 3.4.2 Satisfying 100%, 90%, and 80% of Users 44 3.4.3 On-Demand Delivery 47 3.5 Conclusion 48 IV. Push-Share 50 4.1 Framework Details 50 4.2 System Model 53 4.3 Content Dissemination in Single Cell 56 4.3.1 Content Dissemination by Sharing Only 57 4.3.2 Content Dissemination with Initial Push and Final Push 59 4.3.3 Content Dissemination Energy Cost 62 4.4 Content Dissemination in Multiple Cells 63 4.4.1 Non-steady-state Modeling of MSs in Multiple Cells 66 4.4.2 Steady-State Modeling of MSs in Multiple Cells 66 4.4.3 How Handovers Affect the Content Dissemination 67 4.5 Optimization Framework 69 4.5.1 Minimum Dissemination Completion Delay 69 4.5.2 Minimum Dissemination Completion Cost 70 4.5.3 Conjunctive Minimization of Delay and Cost 71 4.6 Evaluation Results 73 4.6.1 Content Dissemination within One Single Cell 74 4.6.2 Content Dissemination within Multiple Cells 77 4.6.3 Optimization Framework 80 4.7 Conclusion 82 V. Summary and Future Work 84 5.1 A Comparison with Traffic Offloading based on Wi-Fi APs 85 5.2 Practical Deployment and Application 86 5.3 Future Work and Vision 88 Bibliography 90Docto

Music festival motivation in China: free the mind

This paper explores the extent to which music festival attendance is ‘universally’ motivated or determined by the Chinese cultural and socio-political context. A novel qualitative approach was employed comprising observation of social media conversations and ‘chat room’ interviews with members of a festival online community. Seven motivators were identified, some similar to those in Western studies but others more specific to festival-goers in Mainland China. The culturally specific motivators were identified as ‘spiritual escape’ and ‘spiritual pursuit’ and the universal motivators as ‘togetherness’, ‘love of the music’, ‘novel experience’, ‘music sharing’ and ‘educational enrichment’. This paper focuses on the two culturally embedded motivators only. The implications of the study are that, although, growing, there are still very few music festivals featuring ‘pop’ or ‘western’ style music and these few are relatively new to Chinese people. Their attendance at them is, therefore, motivated differently to attendees at similar festivals in western countries. These motivating factors are mediated by the particular social, political and cultural factors at work in this complex country. The findings indicate that although many of the motivational factors for attending a music festival appear to be universal, there are clearly factors which are culturally bound and therefore unique to the cultural context. These differences appear to be created by the social constraints, rapidly changing economy and the many contradictions inherent in modern Mainland China. These conditions create a greater contrast between everyday life in Mainland China and the liminal hedonistic space provided by the festival. Further research is needed to validate theses initial findings within China and to explore how rock music festival motivations differ in other non-western cultures

Delay analysis of social group multicast-aided content dissemination in cellular system

Based on the common interest of mobile users (MUs) in a social group, the dissemination of content across the social group is studied as a powerful supplement to conventional cellular communication with the goal of improving the delay performance of the content dissemination process. The content popularity is modelled by a Zipf distribution in order to characterize the MUs’ different interests in different contents. The Factor of Altruism (FA) terminology is introduced for quantifying the willingness of content owners to share their content. We model the dissemination process of a specific packet by a pure-birth based Markov chain and evaluate the statistical properties of both the network’s dissemination delay as well as of the individual user-delay. Compared to the conventional base station (BS)- aided multicast, our scheme is capable of reducing the average dissemination delay by about 56.5%. Moreover, in contrast to the BS-aided multicast, increasing the number of MUs in the target social group is capable of reducing the average individual userdelay by 44.1% relying on our scheme. Furthermore, our scheme is more suitable for disseminating a popular piece of content