• Journal of the Korea Society of Computer and Information
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• v.16 no.9
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• pp.115-122
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• 2011

In this paper, we propose an efficient dynamic workload balancing strategy which improves the performance of high-performance computing system. The key idea of this dynamic workload balancing strategy is to minimize execution time of each job and to maximize the system throughput by effectively using system resource such as CPU, memory. Also, this strategy dynamically allocates job by considering demanded memory size of executing job and workload status of each node. If an overload node occurs due to allocated job, the proposed scheme migrates job, executing in overload nodes, to another free nodes and reduces the waiting time and execution time of job by balancing workload of each node. Through simulation, we show that the proposed dynamic workload balancing strategy based on CPU, memory improves the performance of high-performance computing system compared to previous strategies.

• Journal of the Korea Institute of Information Security & Cryptology
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• v.23 no.5
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• pp.885-896
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• 2013

MTC(Machine Type Communications), providing a variety of services anytime and anywhere by connecting the cellular network to the machine and things without human intervention, is being considered as a major challenge of the next-generation communications. Currently, When a massive MTC devices simultaneously connect to the network, each MTC device needs an independent access authentication process. Because of this process, authentication signaling congestion and overload problems will cause in LTE-Advanced. In this paper, we propose a group-based authentication protocol and a key management protocol. For managing the MTC devices as group units, the proposed protocol elects a group leader and authentications only once with the core network. After the authentication is completed, a group leader manages the rest members and MME(Mobility Management Entity) by constructing a binary tree. Finally, the propose protocol analysis show that the proposed protocol not only can reduces the authentication signaling which generated in between the MTC devices and the core network but also can manages the MTC devices, efficiently.

• Journal of The Korean Association of Information Education
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• v.13 no.4
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• pp.423-432
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• 2009

This study aims to analyze strategy, one of the predictor variables that have influence on the effectiveness of learning in e-learning environment and to define the factors of e-learning strategies of elementary school students. Preceding studies on face-to-face strategy and e-learning strategy, and existing face-to-face and e-learning strategy test sheets were analyzed. Questions are developed based on the results to make clear the area of leaning strategies used by elementary school students in e-learning environment and to analyze the e-learning strategies of elementary school students. The results from this study are, the e-learning strategies of elementary school students are shown in five areas including strategy for learning activity, strategy for learning attitude, resource use strategy, planning strategy, and overload management strategy. It was found that five strategy areas have explanatory power in the order of strategy for learning activity, strategy for learning attitude, resource use strategy, planning strategy, and overload management strategy.

• Journal of Korea Multimedia Society
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• v.13 no.10
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• pp.1413-1422
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• 2010

With the emergence of digital TV broadcasting, various channels are provided to a TV audience. But it is getting hard for the audience to find his or her preferred TV programs due to the huge number of TV channels. In order to mitigate the difficulty, TV broadcasting companies provide an electronic program guide (EPG), which is a digital guide to scheduled broadcast TV programs. However, it results in the information overload problem and the time-consuming problem since the number of TV channels and programs is gradually on the increase. In this paper, we design and develop a channel filtering system, which recommends a small number of channels by filtering TV channels based on the watching pattern of the TV audience. The channel filtering system does not require the replacement or upgrade of existing TV or set-top box. In addition, it increases usability by skipping the channels that broadcast the audience's non-preferred TV programs while the TV audience presses the channel up/down button.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.37B no.12
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• pp.1102-1112
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• 2012

We propose a cell selection and resource allocation scheme that assigns users to nearby accessible cells in heterogeneous wireless networks consisting of macrocell, femtocells, and Wi-Fi access points, under overload situation. Given the current power level of all accessible cells nearby users, the proposed scheme finds all possible cell assignment mappings of which user should connect to which cell to maximize the number of users that the network can accommodate at the same time. We formulate the cell selection problem with heterogeneous cells into an optimization problem of binary integer programming, and compute the optimal solution. We evaluate the proposed algorithm in terms of network access failure compared to a local ad-hoc based cell selection scheme used in practical systems using network level simulations. We demonstrate that our cell selection algorithm dramatically reduces network access failure in overload situation by fully leveraging network resources evenly across heterogeneous networks. We also validate the practical feasibility in terms of computational complexity of our binary integer program by measuring the computation time with respect to the number of users.

• Management & Information Systems Review
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• v.10
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• pp.1-31
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• 2002

As the modern society is called the narcissistic society, the narcissism is widespread in the personality of individuals and the society at large. In consideration of this side, this study explored for several characteristics of the narcissistic personality and the job stress, and explored for the relationships between the two things theoretically. The narcissism is an attempt to repair self-esteem weakened by the splitting anxiety, the lack and the pathological fusion of self-structure. The job stress is a factor that a characteristic of the job influenced on the behavioral and affective response of the person on the job directly or indirectly. This study selected organizational justices, organizational constraints, role conflict, role ambiguity, role overload, organizational climate, interpersonal relations and career development as factors of the job stress. This study viewed that the stress is made from an interaction between environmental stimulus and personal particular reaction by defining the stress as an interaction model of stimulus-response and personal reaction is caused by psychological adjustment process, personal differences. On this occasion, this study discussed that the narcissistic personality is easy to get stress and weak in the job stress with regarding the personality as a mediation variation of psychological process. As a result, the narcissists estimated themselves positively and their self-esteem is high, but they excessively showed a self biased cognitive and affective response about the negative feedback to protect themselves. Moreover, this positive estimate on themselves and high self-esteem was vulnerable and weak in the self threat. In this view, the narcissistic personality is easy to get more job stress such as organizational justices, organizational constraints, role conflict, role ambiguity, role overload, organizational climate, interpersonal relations and career development.

• Journal of the Korea Society of Computer and Information
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• v.19 no.6
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• pp.81-92
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• 2014

In this paper, we propose an efficient dynamic workload balancing strategy which improves the performance of high-performance computing system. The key idea of this dynamic workload balancing strategy is to minimize execution time of each job and to maximize the system throughput by effectively using system resource such as CPU, memory. Also, this strategy dynamically allocates job by considering demanded memory size of executing job and workload status of each node. If an overload node occurs due to allocated job, the proposed scheme migrates job, executing in overload nodes, to another free nodes and reduces the waiting time and execution time of job by balancing workload of each node. Through simulation, we show that the proposed dynamic workload balancing strategy based on CPU, memory improves the performance of high-performance computing system compared to previous strategies.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.9 no.8
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• pp.1669-1675
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• 2005

Recently, the small sized wireless terminals have problems of processing of large sized file because of the trends of a small sized terminals and a large sized files. Moreover, the web servers or the file servers have problems of the overload because of the concentration with many number of files to the them. Also, There is a security vulnerability of the data processing caused by the processing with a unit of the independent file. To resolve the problems, this paper proposes a new scheme of fat splining distribution using the P2P networks with the mesh topology. The proposed scheme is to distribute blocks of file into any peer of P2P networks. It can do that the small sized wireless terminals can process the large size file, the overload problems of a web or file servers can solve because of the decentralized files, and, the security vulnerability of the data processing is mitigated because of the distributed processing with a unit of the blocks to the peers.

• Journal of KIISE:Computing Practices and Letters
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• v.8 no.3
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• pp.328-335
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• 2002

When we want to transfer video streaming data through computer networks, we will have to be allocated a larger bandwidth compared to a general application. In general, it causes a serious network overload inevitably due to the limited bandwidth. In this paper, in order to resolve the problem, we haute taken a method for transmitting video streaming data using RTP and RTCP. With RR(Receiver Report) packet in RTCP we will test it to check whether the traffic in a network has occurred or not. If it happened, we haute tried to reduce the overall network traffic by dynamically changing the quantization factor of the Motion JPEG that is one of the encoding styles in JMF. When the ratio of the average of transmission for each session to the average of overall transmission is greater than 7%, we should adjust the amount of data to be transmitted for each session to reach the session mean values. The experimental results show that the proposed method taken here reduces the overload effectively and therefore improves the efficiency for transmitting video streaming data.

• The Transactions of the Korea Information Processing Society
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• v.4 no.11
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• pp.2822-2831
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• 1997

A B-ISDN network based on ATM must support several kinds of transport services with different traffic characteristics and service requirements. There is neither link-by-link flow control nor error control in the ATM layer. For different services, different flow/error controls could be performed at the AAL layer or at a higher Iayer(e.g. transport layer). In traditional data networks, the window now control mechanism combined with error control was used prevalently. But, the window flow control mechanism might be useless in ATM networks because the propagation delay is too large compared with the transmission rate. In this paper, we propose a simple flow control mechanism, called RCT(Rate Control for end-to-end Transport), for end-to-end data transport. The RCT shows acceptable performance when the average overload period is bounded by a certain time.