• Asia pacific journal of information systems
• /
• v.22 no.4
• /
• pp.101-123
• /
• 2012

Currently, Social Media, it has widely a renown keyword and its related social trends and businesses have been fastly applied into various contexts. Social media has become an important research area for scholars interested in online technologies and cyber space and their social impacts. Social media is not only including web-based services but also mobile-based application services that allow people to share various style information and knowledge through online connection. Social media users have tendency to common identity- and bond-attachment through interactions such as 'thumbs up', 'reply note', 'forwarding', which may have driven from various factors and may result in delivering information, sharing knowledge, and specific experiences et al. Even further, almost of all social media sites provide and connect unknown strangers depending on shared interests, political views, or enjoyable activities, and other stuffs incorporating the creation of contents, which provides benefits to users. As fast developing digital devices including smartphone, tablet PC, internet based blogging, and photo and video clips, scholars desperately have began to study regarding diverse issues connecting human beings' motivations and the behavioral results which may be articulated by the format of antecedents as well as consequences related to contents that people create via social media. Social media such as Facebook, Twitter, or Cyworld users are more and more getting close each other and build up their relationships by a different style. In this sense, people use social media as tools for maintain pre-existing network, creating new people socially, and at the same time, explicitly find some business opportunities using personal and unlimited public networks. In terms of theory in explaining this phenomenon, social capital is a concept that describes the benefits one receives from one's relationship with others. Thereby, social media use is closely related to the form and connected of people, which is a bridge that can be able to achieve informational benefits of a heterogeneous network of people and common identity- and bonding-attachment which emphasizes emotional benefits from community members or friend group. Social capital would be resources accumulated through the relationships among people, which can be considered as an investment in social relations with expected returns and may achieve benefits from the greater access to and use of resources embedded in social networks. Social media using for their social capital has vastly been adopted in a cyber world, however, there has been little explaining the phenomenon theoretically how people may take advantages or opportunities through interaction among people, why people may interactively give willingness to help or their answers. The individual consciously express themselves in an online space, so called, common identity- or bonding-attachments. Common-identity attachment is the focus of the weak ties, which are loose connections between individuals who may provide useful information or new perspectives for one another but typically not emotional support, whereas common-bonding attachment is explained that between individuals in tightly-knit, emotionally close relationship such as family and close friends. The common identify- and bonding-attachment are mainly studying on-offline setting, which individual convey an impression to others that are expressed to own interest to others. Thus, individuals expect to meet other people and are trying to behave self-presentation engaging in opposite partners accordingly. As developing social media, individuals are motivated to disclose self-disclosures of open and honest using diverse cues such as verbal and nonverbal and pictorial and video files to their friends as well as passing strangers. Social media context, common identity- and bond-attachment for self-presentation seems different compared with face-to-face context. In the realm of social media, social users look for self-impression by posting text messages, pictures, video files. Under the digital environments, people interact to work, shop, learn, entertain, and be played. Social media provides increasingly the kinds of intention and behavior in online. Typically, identity and bond social capital through self-presentation is the intentional and tangible component of identity. At social media, people try to engage in others via a desired impression, which can maintain through performing coherent and complementary communications including displaying signs, symbols, brands made of digital stuffs(information, interest, pictures, etc,). In marketing area, consumers traditionally show common-identity as they select clothes, hairstyles, automobiles, logos, and so on, to impress others in any given context in a shopping mall or opera. To examine these social capital and attachment, we combined a social capital theory with an attachment theory into our research model. Our research model focuses on the common identity- and bond-attachment how they are formulated through social capitals: cognitive capital, structural capital, relational capital, and individual characteristics. Thus, we examined that individual online kindness, self-rated expertise, and social relation influence to build common identity- and bond-attachment, and the attachment effects make an impact on both the willingness to help, however, common bond seems not to show directly impact on information sharing. As a result, we discover that the social capital and attachment theories are mainly applicable to the context of social media and usage in the individual networks. We collected sample data of 256 who are using social media such as Facebook, Twitter, and Cyworld and analyzed the suggested hypotheses through the Structural Equation Model by AMOS. This study analyzes the direct and indirect relationship between the social network service usage and outcomes. Antecedents of kindness, confidence of knowledge, social relations are significantly affected to the mediators common identity-and bond attachments, however, interestingly, network externality does not impact, which we assumed that a size of network was a negative because group members would not significantly contribute if the members do not intend to actively interact with each other. The mediating variables had a positive effect on toward willingness to help. Further, common identity attachment has stronger significant on shared information.

• The Journal of Korean Institute of Communications and Information Sciences
• /
• v.19 no.9
• /
• pp.1719-1729
• /
• 1994

In this paper, an adaptive CAC(Connection Admission Control) method is proposed. The adaptive CAC uses traffic estimates derived from both traffic parameter specified by user and cell flow measurements. Traffic estimation using user-specified parameters is performed at every moment of connection request or connection release by recursive formula which makes real-time calculation possible. Traffic estimation using cell flow measurement is carried out when the number of connected calls does not change during a measurement reflection period-renewal period. The most import ant thing for the traffic estimation using cell flow measurement is the determination of the length of a renewal period to trace a real traffic flow with an allowable time lag and the measurement reflection ratio(MRR) both to reduce the portion of overestimation and to avoid underestimation of real traffic flow. To solve these problems, the adaptive CAC updates renewal period and MRR adaptively according to the number of connections and the elapsed time after last connection or release respectively. Performance analysis for the proposed method is evaluated in several aspects for the cases of both homogeneous and heterogeneous bursty traffic. Numerical examples show the adaptive CAC method has the better performance compared with conventional CAC method based on burst model from the both utilization and QOS point of view.

• Journal of Intelligence and Information Systems
• /
• v.16 no.1
• /
• pp.93-116
• /
• 2010

Ensemble approach is applied to the detection modeling of illegal cash accommodation (ICA) that is the well-known type of fraudulent usages of credit cards in far east nations and has not been addressed in the academic literatures. The performance of fraud detection model (FDM) suffers from the imbalanced data problem, which can be remedied to some extent using an ensemble of many classifiers. It is generally accepted that ensembles of classifiers produce better accuracy than a single classifier provided there is diversity in the ensemble. Furthermore, recent researches reveal that it may be better to ensemble some selected classifiers instead of all of the classifiers at hand. For the effective detection of ICA, we adopt ensemble size reduction technique that prunes the ensemble of all classifiers using accuracy and diversity measures. The diversity in ensemble manifests itself as disagreement or ambiguity among members. Data imbalance intrinsic to FDM affects our approach for ICA detection in two ways. First, we suggest the training procedure with over-sampling methods to obtain diverse training data sets. Second, we use some variants of accuracy and diversity measures that focus on fraud class. We also dynamically calculate the diversity measure-Forward Addition and Backward Elimination. In our experiments, Neural Networks, Decision Trees and Logit Regressions are the base models as the ensemble members and the performance of homogeneous ensembles are compared with that of heterogeneous ensembles. The experimental results show that the reduced size ensemble is as accurate on average over the data-sets tested as the non-pruned version, which provides benefits in terms of its application efficiency and reduced complexity of the ensemble.

• The KIPS Transactions:PartB
• /
• v.15B no.1
• /
• pp.37-44
• /
• 2008

With the growing proliferation of mobile computing devices, several industrial and academic research groups have a vigorous studying to remote control for various appliances with mobile devices such as Notebooks, PDAs, and Smartphones in home network environments. We can utilize the good points of mobile devices such as portability and usability so that we can remote control and manage the mobile devices connected on home networks anytime, anywhere. However, mobile devices use different languages. Therefore, they cause some problems because their interfaces and the methods of operation are different each other. To solve these problems, there are two consideration. First, we may be solved development of the user interface and difficulty of maintenance in order to control various heterogeneous devices. Second, we may provide the user interface which is dynamically adapting user's preferences and device characteristics. To satisfy these considerations, we describe the design of an adaptive user interface for home network environments using the UIML (User Interface Markup Language) based on XML (eXtensible Markup Language) and the profile information of the user and device. Therefore, we present several implementation examples that show how the framework can form the basis of prototypical applications.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
• /
• 2009.10a
• /
• pp.1022-1025
• /
• 2009

USN(Ubiquitous Sensor Network) is a core infrastructure that makes come true the u-life in the ubiquitous society through various services of area such as u-city and u-Health. Therefore, we need to reseach about the domestic standards to establish the core technique of USN. Currently, the status of USN standards is most of technical standard and reseach that are technology for sensor node implementation and a protocol for energy-efficient communication and interlock with existing network. But, Standard and reseach for sensor network, integration management of heterogeneous sensor networks for USN application, sensing data management and USN database structure definition such as application and middleware are weak level. In this paper, we researched for standard development of the domestic sensor network service and relevant standard analysis to configure SWE(Sensor Web Enablement) of OGC(Open Geospatial Consortium) for standarded plattform technoloy in part of the middleware. Also we researched that it's a connection between domestic TTA (Telecommunications Technology Association) standards and SWE Standard. Finally, we researched for standard service plattform architecture on sensor network through analysis on the possibility of applying OGC-based services platform.

• Journal of the Institute of Electronics Engineers of Korea TC
• /
• v.43 no.11 s.353
• /
• pp.149-158
• /
• 2006

We proposed a method for improving a performance of TCP downstream between a desktop PC as a fixed host and a PDA as a mobile host in a wired and wireless network based on IEEE 802.11x wireless LAN. With data transmission between these heterogeneous terminals a receiving time during downstream is slower than that during upstream by 20% at maximum. The reason is that their congestion window size will be oscillated due to a significantly lower packet processing rate at receiver compared to a packet sending rate at sender. Thus it will cause to increase the number of control packets to negotiate their window size. To mitigate these allergies, we proposed two distinct methods. First, by increasing a buffer size of a PDA at application layer an internal processing speed of a socket receive buffer of TCP becomes faster and then the window size is more stable. However, a file access time in a PDA is kept nearly constant as the buffer size increases. With the buffer size of 32,768bytes the receiving time is faster by 32% than with that of 512bytes. Second, a delay between packets to be transmitted at sender should be given. With an inter-packet delay of 5ms at sender a resulting receiving time is faster by 7% than without such a delay.

• Journal of the Institute of Electronics Engineers of Korea SD
• /
• v.43 no.2 s.344
• /
• pp.60-75
• /
• 2006

The MPEG-21 Multimedia Framework initiative aims to support a wide range of networks and devices in the delivery and consumption of multimedia resources. One of the primary goals of MPEG-21 is universal multimedia access (UMA) through Digital Item Adaptation (DIA), which supports multimedia streaming to heterogeneous devices ensurung the same readability and seamlessness. We pioneer power saving of luminal devices with MPEG-21 DIA, so that the MPEG-21 DIA can also be used to support power saving, even though the framework is not primarily designed for power reduction and only limited power awareness is defined by DIA. We introduce several power-saving techniques conforming to MPEG-21 DIA specifications and show the dependency relation among introduced techniques. We achieve energy savings of up to $66\%$ in hand-held multimedia devices with minor QoS (quality of service) degradation.

• The KIPS Transactions:PartC
• /
• v.17C no.3
• /
• pp.271-280
• /
• 2010

For the next generation mobile communication system, diverse wireless network techniques such as beyond 3G LTE, WiMAX/WiBro, and next generation WLAN etc. are proceeding to the form integrated into the All-IP core network. According to this development, Beyond 3G integrated into heterogeneous wireless access technologies must support the vertical handover and network to be used of several radio networks. However, unified management of each network is demanded since it is individually serviced. Therefore, in order to solve this problem this study is introducing the theory of Common Radio Resource Management (CRRM) based on Generic Link Layer (GLL). This study designs the structure and functions to support the vertical handover and propose the vertical handover algorithm of which policy-based and MCDM are composed between LTE and WLAN systems using GLL. Finally, simulation results are presented to show the improved performance over the data throughput, handover success rate, the system service cost and handover attempt number.

• Journal of the Institute of Electronics Engineers of Korea TC
• /
• v.48 no.12
• /
• pp.17-27
• /
• 2011

Most of the previous mobility management protocols such as IETF MIPv4/6 and its variants standardized by the IETF do not support global seamless handover because they require partially changes of the existing network infrastructure. In this article, we propose a simple mobility management protocol (SMMP) which can support global seamless handover between homogeneous or heterogeneous wireless networks. To do this, the SMMP employs separate location management function as DMMS to support global user and service mobility and the bidirectional tunnels are dynamically constructed to support seamless IP mobility by using the IEEE MIH extension server, which is extended the IEEE 802.21 MIH standards. The detailed architecture and functions of the SMMP have been designed. Finally, the mathematical analysis and the simulation have been done. The performance results show the proposed SMMP outperforms the existing MIPv6 and HMIPv6 in terms of handover latency, packet loss, pear signal noise ratio (PSNR).

• Journal of Internet Computing and Services
• /
• v.14 no.5
• /
• pp.27-38
• /
• 2013

Currently a number of managers exist to manage heterogeneous networks, in this situation, the NETCONF protocol for efficient network management has been proposed as a new protocol. However, the standard NETCONF protocol stack continuous improvement since the establishment but in four layers still have some problems. Especially in situations where there are multiple administrators, problems are more highlighted in operation layer. In this paper, we focus on these issues and the Operation layer has improved the efficiency and flexibility of operations among NETCONF four layers. Additionally, for the inefficiency of updates improved the device settings based on improved operation techniques. In addition, standard protocol NETCONF did not proposed content layer data structure and we propose standard technique of content layer that can generate configuration structure of devices. Improved the three techniques are applied appropriately to the NETCONF, the proposed method and the existing NETCONF was performed experiment to compare with experimental four factors. Compare key factor are four kind as maintaining the probability of network function, the reaction performance about command, the number of control packets, performance of data creation in content layer. Such factors after performing the experiment, the proposed method in this paper is superior to the existing NETCONF and there was confirmed by analysis Experimental results.