• Journal of the Korea Concrete Institute
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• v.17 no.2 s.86
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• pp.221-227
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• 2005

The presence of voids behind tunnel linings is very likely to result in settlement or structural collapse. One proposed method of detecting such voids by non-destructive method is radar. More than effectively judging the existence of voids behind tunnel linings, this study aims to develop the analysis algorithm of radar capable of estimation of the shape of specific voids. To acquire directional information and estimate the shape of three-dimensional voids, the radar of three-dipole antenna type is used. As a foundation to this ongoing research, an investigation of microwave polarization methods using three-dipole antenna carried out with various void orientations and void geometries. As a result, it is clarified that the response of four microwave polarization modes depends on void geometry and thus there is a possibility of identifying the geometry and orientation (the shape) of specific voids using radar of three-dipole antenna type.

• Journal of the Korean Solar Energy Society
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• v.36 no.1
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• pp.39-47
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• 2016

Geographic information system (GIS) based renewable energy resource map including potential analysis can play a crucial role not only to develop the national plan for renewable energy deployment but also to make strategic investment decision in the private sector. Korea Institute of Energy Research (KIER) has been developing domestic maps about several resources such as solar, wind, hydro, biomass, and geothermal, as well as conducting research on methodologies for potential analysis. Furthermore, the institute is trying to transfer related technologies and know-how to foreign countries, recently. In this context, the main purpose of this study is to introduce the business model of renewable energy resource map. From the value chain analysis, we focus on the government-side market in foreign countries, such as the development of the national level renewable energy resource map and the support of the national renewable energy plan. For about 180 countries, we segment the customers according to the consideration of economic capacity, renewable energy resource capacity, existence of renewable resource map, current portion of renewable energy facility capacity, and renewable energy policies, and we conclude that the target customers are non-Organization for Economic Co-operation and Development (non-OECD) countries or some OECD countries, their per capita GDP are under the average among OECD countries, that do not have renewable resource map yet. We segment the target customers into four groups, and suggest different strategies for market positioning and financing strategy based on Strengths, Weaknesses, Opportunities, Threats (SWOT) analysis. This study can help to develop the business strategy about the development of renewable energy resource map in foreign countries.

• Journal of the Korean Institute of Telematics and Electronics S
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• v.36S no.10
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• pp.123-131
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• 1999

In this paper, we proposed stereo matching algorithm by dynamic programming with edges emphasized. Existing algorithms show blur generally at depth discontinuities owing to smoothness constraint and non-existence of matching pixel in occlusion regions. Also it accompanies matching error by lackness of matching information in the untextured regions. This paper defines new cost function to make up for the problems occurred to existing algorithms. It is possible through deriving matching of edges in left and right images to be carried out between edge regions anf deriving that in the other regions to be peformed between the other regions. In case of the possibility that edges can be Produced in a large amount, matching between edge information adds weight to cost function in proportion to Path distance. Proposed algorithm was applied to various images obtained by convergent camera model as well as parallel camera model. As the result, proposed algorithm showed improved performance in the aspect of matching error and processing in the occlusion regions compared to existing algorithms. Also it could improve blur especially in discontinuity regions.

• International Journal of Computer Science & Network Security
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• v.22 no.2
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• pp.123-130
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• 2022

During the past decades, detection of gear defects remains as a major problem, especially when the gears are subject to non-stationary phenomena. The idea of this paper is to mixture a multilevel wavelet transform with a fast EMD decomposition in order to early detect gear defects. The sensitivity of a kurtosis is used as an indicator of gears defect burn. When the gear is damaged, the appearance of a crack on the gear tooth disrupts the signal. This is due to the presence of periodic pulses. Nevertheless, the existence of background noise induced by the random excitation can have an impact on the values of these temporal indicators. The denoising of these signals by multilevel wavelet transform improves the sensitivity of these indicators and increases the reliability of the investigation. Finally, a defect diagnosis result can be obtained after the fast transformation of the EMD. The proposed approach consists in applying a multi-resolution wavelet analysis with variable decomposition levels related to the severity of gear faults, then a fast EMD is used to early detect faults. The proposed mixed methods are evaluated on vibratory signals from the test bench, CETIM. The obtained results have shown the occurrence of a teeth defect on gear on the 5th and 8th day. This result agrees with the report of the appraisal made on this gear system.

• International Commerce and Information Review
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• v.13 no.3
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• pp.377-401
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• 2011

Under the WTO system, direct export support system that provides financial and tax related support is altogether prohibited. This presented an obstacle in strengthening competitiveness of Korean export business and in increasing exports continuously. One of the methods used to solve this problem was to actively leverage export insurance. In Korea, export insurance services have been conducted by the Korea Trade Insurance Corporation (k-sure) to promote export. Korea has been among the world's active users of the export insurance system. Given this situation, this paper examines the effectiveness of the Korea export insurance system in the promotion of export. In particular, this study analyzed about discriminating effects of the export insurance on the export of big and small-medium business. In order to analyze, We introduce a Export Supply Function model. In this paper, We construct two model. The one is about big business, the other is small-medium business. For empirical analysis, unit-root test was conducted to understand the safety of time series. The results show that all variables are not I(0) time series. Instead, they are I(1) time series. To this, cointegration verification was conducted based on the use of Johansen verification method to define the existence (or non-existence) of long-term balance relationship among variables. The results come out as follows. The export insurance of big business has a stronger effect on export than that of small-medium business. The cause of these results is due to the distinct structure of Korea industries. In view of the fact that the insurance can make the risk decreased. We can say that the export insurance affects the export of a high-risk country.

• Journal of the Society of Disaster Information
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• v.3 no.2
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• pp.55-78
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• 2007

Currently, the departments related to security and secretary service exist in 18 universities and 30 colleges in Korea in order to raise professional security and secretary personnel. Among the 18 four-year colleges in Korea, only two of them have the ethics course include in their curriculum. Also, among the 31 two-year colleges, only three of them have the ethics course included in their curriculum. Besides, as some private security and guardian companies were recently utilized in illegal actions of the rich and ruling class, contradicting their original purpose of existence, many people point out their downfall as a ?forced private army.? As a professional job, if security secretaries take advantage of the knowledge and top-secret technologies and use them for non-ethical purposes, the effect of the damage is far more serious than other fields of jobs. Therefore, taking this event as a turning point, the contract contents and the task area between the client and the security and secretary company must become more transparent in order to prevent illegal actions, and also for the people working in the security and secretary service area, it is necessary to establish a firm ethical consciousness in order to behave appropriately in their working environment. Therefore, this study examines the proper direction of work ethics of the people working in the security and secretary service according to the professionalization of their field, and also aims to propose an appropriate work ethic system such that they will not become an unfortunate victim of various scandals anymore. To do so, the concept of work ethics in professional jobs was examined; and after the code of ethics that reflect the ethical value system of each professional job was reviewed, the study suggested a specific solution for establishing the codes of ethics for security and secretary service.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.10 no.9
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• pp.4188-4206
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• 2016

Power control is widely used to reduce co-channel interference in wireless networks and guarantee the signal-to-interference plus noise ratio (SINR) of ongoing connections. This technique is also effective for wireless body area networks (WBANs). Although achieving satisfactory SINR is important for WBAN users, they may not be willing to achieve it at arbitrarily high power levels since power is a scarce resource in WBANs. Besides, for WBANs with different purposes, the QoS requirements and concern about the power consumption may be different. This motivates us to formulate the power control problem using the concepts from microeconomics and game theory. In this paper, the QoS objective is viewed as a utility function, which represents the degree of user satisfaction, while the power consumption is viewed as a cost function. The power control problem consequently becomes a non-cooperative multiplayer game, in which each player tries to maximize its net utility, i.e., the utility minus the cost. Within this framework, we investigate the Nash equilibrium existence and uniqueness in the game and derive the best response solution to reach the Nash equilibrium. To obtain the optimal transmission power in a distributed way, we further propose a utility-based and QoS-aware power control algorithm (UQoS-PCA). Tunable cost coefficient in UQoS-PCA enables this scheme to be flexible to satisfy diverse service requirements. Simulation results show the convergence and effectiveness of the proposed scheme as well as improvements over existing algorithm.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.14 no.11
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• pp.2463-2470
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• 2010

In some cases of u-health services, it is important and then required to pursue the location of users in real time because users could occasionally be in the situation beyond self-regulation. Location positioning has used two such typical techniques as trilateration and fingerprinting. A trilateration technique is usually based on three resident coordinates to identify the location of the target node. Ranging that measures distances between coordinates and the node is essential for applying the trilateration technique. Users especially in u-health services could be out of reachability in any such reasons as out of propagation ranges, fault of a communication counterpart, non-existence of possible communication facility, etc. This paper proposes a real-time locating method which can improve to identify and track the location of mobile objects. The method is based on references of identified mobile nodes as well as resident coordinates even though they may be partially out of communication reachability.

• Journal of KIISE:Information Networking
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• v.28 no.4
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• pp.455-462
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• 2001

In this paper, we propose a deterministic algorithm to solve the resource discovery problem, that is, some subset of machines to learn the existence of each other in a large distributed network. Harchol et al. proposed a randomized algorithm solving this problem within O($log^2\;n$) rounds with high probability, which requires O($nlog^2\;n$) connection communication complexity and O($n^2log^2\;n$) pointer communication complexity, where n is the number of machines in the network. His solution is based on randomization method and it is difficult to determine convergence time. We propose an efficient algorithm which improve performance and the non-deterministic characteristics. Our algorithm requires O(log n) rounds which shows O(mlog n) connection communication complexity and O($n^2log\;n$) pointer communication complexity, where m is the number of links in the network.

• Journal of the Korean Society for Precision Engineering
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• v.30 no.2
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• pp.206-215
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• 2013

In recent years, many companies have heavily invested in introducing production informatization systems in order to strengthen the competitiveness and to satisfy consumer's desires in quickly changing market environment. However, it is not effective due to the lack of understanding of systems and of non-existence of an optimal system for each company. Therefore, in this paper, manufacturing companies were classified according to its properties; size of the firm, type of business, production method and job production. After that, a model has been built to calculate the production informatization level, and it has been applied to 450 companies. Results of 450 surveys would be the base for figuring out strategies of introducing the production informatization to the companies which are wishing to build production informatization systems. Finally, Developed in this paper rule base system refer customized guideline to company that wants to adapt production information system.