• Korean Management Science Review
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• v.21 no.1
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• pp.57-76
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• 2004

The development of informational technology has lead to a sharp change in not only the existing way of operations and management, but the way of human life or thinking as well. Those shifts of the paradigm in information technology have also affected Individuals to the organizational structure. A series of unexpected problems was, however, accompanied by the advance in informational technology, which had broaden its own area of application. Those problems include the losses of property or data the malfunction of systems and their wastefulness would result in, continuous increases in computer crimes, reliability and efficiency of the functional process with the development of information systems, such as the processing problems of inaccurate data, economical issues, and subjects related to safety, as interruptions of privacy, which would result from lots of one's exposure to the drains of personal information. Accordingly, Auditors' roles of information systems, for now, is more important than anything else in that they are responsible for the objective assessment of relevance and effectiveness of internal control systems under the environment of information systems. The objective of the study is, so as to obtain safety of information systems： First, to provide data to line-design internal control systems after finding internal control factors to prevent and eliminate the risks of information systems. Second, to evaluate the priorities of internal control factors with their effective management being considered as the key to settle the problems of risks of information systems. Third, to discriminate what factors affect In evaluating the relative degrees of Importance of internal control factors.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.35 no.7B
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• pp.1001-1008
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• 2010

In this paper, we propose the dynamic spectrum allocation (DSA) algorithm using spectrum sharing method considering the long-term priority between NOs and service classes for the maritime communication system environment where a ship locates at either near shore (or land) or off-shore. It was shown that the proposed algorithm using spectrum sharing with priorities could deliver better satisfaction ratio (SR) than the fixed allocation schemes, in the context of provision of required bandwidth (or spectrum) for each users. Therefore, we conclude that the proposed DSA with priorities could apply to the maritime communication environment and exploit the under-used (or unused, idle) spectrum of terrestrial communication networks.

• Journal of Distribution Science
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• v.15 no.10
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• pp.81-92
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• 2017

Purpose - One of the main objectives of this paper is to identify the most effective type of social media and to analyze the priority of blogs by their informational attributes in the aspect of their impacts on word-of-mouth intention(WOM) in on-line markets. Research design, data, and methodology - We set 'attitude' variable in the middle to see if there is mediating effects between blog information and word-of-mouth intention. We conducted a survey by questionnaire and received 206 answers. Employing the OLS statistical methods through the SPSS package, we tested our hypotheses. Results - Some of the main results are the followings. First, blog, micro-blog, and profile-based services showed significant effects on WOM, while Internet community and mini-homepages are not significant. Second, blog has positive impacts on WOM. Third, attitude has perfect mediating effects between blog and WOM. Fourth, in terms of effects on WOM, interactivity shows the first priority and reliability and usability follows. Finally, attitude has a more significant effect for users of 3 types of blog compared with those of 2 types. Conclusions - In this paper, we analyzed the effects of social network services by type and identified the priority among various attributes of information contained in blogs. It would provide businesses with viable strategic options to establish public relations in their sales promotion.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.13 no.8
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• pp.1653-1658
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• 2009

SoC(System on a Chip) has several masters, slaves, arbiter and decoder in bus architecture. Master initiates the data transactions like CPU, DMA and DSP and slave responses the data transactions like SRAM, SDRAM and register. Furthermore, as multiple masters can't use a bus concurrently, arbiter plays an role in bus arbitration. In compliance with the selection of arbitration method, SoC performance can be changed definitely. In this study, we compare the characteristics of various arbitration policies using TLM(Transaction Level Model) method. Fixed priority, round-robin, TDMA and Lottery bus policies are used in general arbitration method. We analyze the merit and demerit of these arbitration policies.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.33 no.6A
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• pp.607-613
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• 2008

In this paper, we investigate the performance of SMP-assisted 3GPP GERAN evolution system employing high order modulation and turbo coding. When applying the SMP which maps systematic bits into highly reliable bit positions, it is confirmed that there is the performance gain for the modulation and coding schemes of 16QAM(DAS-8) as well as 32QAM(DAS-11) by link level simulation.

• Journal of Environmental Impact Assessment
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• v.18 no.6
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• pp.367-376
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• 2009

This paper proposes an application methodology of AHP(Analytic Hierarchy Process) based decision making theory for improvement priority by assessment of various risk factors affecting on deterioration of water supply systems, as major social infrastructure. AHP method is organized with three level of hierarchy which is introduced for multi-criteria decision making in this study. In the first level, assessment outputs are calculated by AHP for each affecting factor. In the second level, criteria are estimated by using assessment results with respect to structural and environmental factors. Consequently, ranking decision is performed in the third level. In order to present the effectiveness, a proposed method is compared with FCP(Fuzzy Composite Programming) for decision making. Since the results of the proposed method show better performance with consistent results, it can be applied as an efficient information for the determination for improvement priority of the study infrastructure.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.21 no.8
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• pp.1928-1936
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• 1996

In this paper, we propose an adaptive bandwidth allocation algorithm for the transmission of VBR video through ATM Networks. In order to evaluate the required bandwidth for the VBR video, the characteristics of the compressed VBR video generated by the two-layered coder are analyzed with variations in the number of GOP(N), quantizer scale(q), and the number of low-frequency DCT coefficients(.betha.). The two-layer coder which is used to separate from the number of DCT coefficients is designed to transmit the VBR video efficiently. The compressed data generated by the two-layer coder are splitted into the high priority and low priority cells. If congestion is occurred in ATM networks, the minimum image quality is maintained by the high priority cells. The required bandwidth for VBR video is estimated with a prediction algorithm using the scene anframe correlations as well as the statistical properties of the VBR video sources. Strong correlation among the adjacent slices in a frame represents by the scene correlation andstrong correlation among the frames is represented by the frame correlation. The performance of the bandwidth allocation scheme proposed is evaluated in terms of the bandwith utilization, cell loss rate, and SNR with variations in q, n, .betha.. Simulation rewsults shown that the proposed scheme is superior to the conventional methods.

• Journal of the Korea Society of Computer and Information
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• v.12 no.2 s.46
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• pp.111-121
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• 2007

In mobile computing environments, data broadcasting is widely used to resolve the problem of limited power and bandwidth of mobile equipments. However, the previous broadcast scheduling methods can be inefficient in the environment where the user requests change dynamically since they are based on static data requests. Moreover, a high-priority user can wait long for infrequently requested data because they never consider the priority of listeners. In this paper, we propose a new broadcast scheduling method that reflects dynamic changes of user requests using user profiles. It also reflects user priorities to reduce the access time of high-priority users. We evaluate the performance of the proposed method through simulation.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.19 no.5
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• pp.842-856
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• 1994

The various services that a broadband integrated services digital network (B-ISDN) carries, have a wide range of delay, delay jitter and cell loss probability requirements. Design of appropriate control schemes for B-ISDN is an extremely important and challenging problem. In this paper, we proposed multiplexing algorithm with both delay and loss priorities in order to satisfy the diverse requirements. For the implementation of cell lose priority, we assumed that voice cells are generated as non-discardable(i.e., high priority) and discardable (i.e., low priotity)cells. The low priority voice cell may be discarded inside the network if congestion occurs. The cell dropping scheme is shown to reduce cell losses as well as delays for both voice and data. Such a load shedding scheme is expected to improve significantly utilization of B-ISDN.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.31 no.3B
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• pp.232-238
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• 2006

We propose a novel call admission control scheme which improves the handoff drop and the new call block probabilities of high priority services, minimizing the negative impact on low priority services, in multimedia service cellular networks. This paper proposes three schemes to solve this problem; the packing scheme in which available channels of a cell distributed to each frequency channel are concentrated on one frequency channel and a high transmission rate service is assigned to the frequency channel; the queuing scheme in which the queue is used for high transmission rate calls; and the power reallocation scheme in which the power assigned to calls under service is temporarily reduced and a high transmission rate service is allowed. The simulation results revealed that our scheme improved the drop and the block probabilities of the high priority services compared with the conventional scheme.