• Journal of Korean Institute of Industrial Engineers
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• v.27 no.3
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• pp.250-259
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• 2001

Given a tree structured network in which each node has its own demand and also stands for a candidate location of a potential facility, such as plant or warehouse, a capacitated facility location problem on the network (CFLPOT) is to decide capacitated facility locations so that the total demand occurred on the network can be satisfied from those facilities with the minimum cost. In this paper, we first introduce a mixed integer programming formulation for CFLPOT with two additional assumptions, the indivisible demand assumption and the contiguity assumption and then show that it can be reformulated as a tree partitioning problem with an exponential number of variables. We then show that it can be solved in O($n^2b$) time by utilizing the limited column generation method developed by Shaw (1993), where n is the total number of nodes in the network and b is the maximum facility capacity. We also develop a depth-first dynamic programming algorithm with a running time of O(nb) for finding the locally maximal reduced cost which plays an important role in the limited column generation method. Finally, we implement our algorithms on a set of randomly generated problems and report the computational results.

• Journal of the Korean Society of Safety
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• v.32 no.4
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• pp.1-6
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• 2017

Functionally Graded Materials (FGM) as advanced heterogeneous composite materials have a higher performance than a conventional composite or bimaterial composite under some severe environments. As a heterogeneous material, FGM is commonly used in spacecraft, defense, nuclear and automotive industries due to its excellent properties. The purposes of this study are to evaluate the stress distribution and crack behaviors by the multiscale simulation. FGM contains two or more than two materials that the composition is structured continuously. Two types of FGM model are suggested, which are created by arbitrary prediction of the volume fraction and the exponential function. Aluminum as the metal matrix constituent and silicon carbide as the ceramic particle constituent are structured gradually by two types and the three point bending test also estimated. Moreover, two kinds of crack location were introduced in order to get the influences of material property distribution on the stress intensity factor. From the results we found that the stress intensity factors are increased in the case from softer to stiffer material, while vice versa.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.14 no.2
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• pp.219-228
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• 1996

The list of the titles of surveying-related papers and books is updated by adding newly polished paper/book titles to the existing one. A special title-search program is developed for managing and searching the surveying-re-lated paper/book titles, and the database is established from the list of the papers. The total number of papers/books in surveying-related field published in Korea upto now is 971. The number of papers/books published in the specific fields are 206 in the conventional surveying field, 218 in Photogrammetry, 183 in Remote Sensing, 127 in Geodesy and GPS, and 237 in Digital Mapping and GIS. The special title-search program is developed using the Visual Basic 3.0 for Windows 3.1 to be operated in the Window environment. The SQL(Structured Query Language) is used for the searching commands.

• Journal of the Korean Operations Research and Management Science Society
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• v.23 no.1
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• pp.161-181
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• 1998

Translating expert knowledge into production rules has been the most difficult and time-consuming when building expert systems (Buchanan et al. 1983). Especially, buidling hierarchical structure, i. e. developing sequential or dominant relationship among production rules is one of the most important and difficult processes. Hierarchical relationship among rules has been typically determined in the course of interviewing human experts. Since this interviewing procedure is rather subjective, however, the hierarchically structured rules produced in terms of interviewing is widely exposed to the severe discussion about their validity (Nisbett and Wilson 1977 : Ericsson and Simon 1980 : Kellog 1982). We thus need an objective method to effectively translate human expert knowledge into structured rules. As such a method, this paper suggests the order anlaysis technique that has been studied in psychometries (Cliff 1977 : Reynolds 1981 : Wise 1983). In this paper we briefly introduce the order analysis and explain how it can be applied to building hierarchical structure of production rules. We also illustrate how bankrupcy prediction rules of small-medium companies can be developed using this order analysis technique. Further, we validata the effectiveness of these rules developed by the order analysis, in comparison with those built by other methods. The rules developed by the proposed outperform those of the other traditional methods in effectively screening the bankrupted firms.

• The Journal of Asian Finance, Economics and Business
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• v.5 no.2
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• pp.73-79
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• 2018

The purpose of this study is to explore how small and medium enterprises in India has identified the opportunities and challenges in adopting the Web 3.0 technologies to improve their productivity and efficiency. After an in-depth literature review, researchers framed a semi-structured questionnaire with open-ended questions for collecting responses from managers working in 40 Indian SME's representing five key economic sectors. The collected data was analyzed, and themes were encoded using the NVivo 11 computer-assisted qualitative data analysis software. Content analysis was used to analyze the data collected with the semi-structured interviews. This study identified five key themes and 12 subthemes illustrating the key advantages and challenges as perceived by the managerial leadership of SMEs. The five key themes identified in this study include integration of data and services, the creation of new functionalities, privacy and security, financial and technological challenges, and organizational challenges. The results of this study will benefit the organizational leadership of SMEs in planning and developing their short-term and long-term information systems strategies and will enable SME leaders to make optimal use of their information technology assets, improving the productivity and competitiveness of the firms. Web 3.0 technologies are considered as emerging technologies, so the advantages and challenges of using these technologies for SMEs have not been explored in the context of emerging economies, such as India.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.9 no.2
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• pp.295-300
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• 2005

In this paper we have designed a two-stage Class I power amplifier operated at 2.4CHz for Class-1 Bluetooth application. The power amplifier employs class-I topology to exploit its soft-switching property for high efficiency. The latch-structured pre-amplifier with amplifiers makes its output signal as sharp as possible for soft switching of the next power amplifier. It improves the overall efficiency of the proposed power amplifier. It shows 65.8$\%$ PAE, 20dB power gain and 20dBm output power.

• Journal of the Korean Society for information Management
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• v.29 no.2
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• pp.113-133
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• 2012

This study is an exploratory research on the user relevance criteria in Korean search service environments that provide integrated search results. Data were collected from 10 participants using a semi-structured interview technique. The participants conducted a web search using integrated search services, such as Naver or Daum on a self-selected topic. They were asked to judge the relevance of retrieved documents and to report their relevance criteria. As a result, the research indicated 8 user-defined relevance and non-relevance criteria. The research shows that specificity and richness are the two most important criteria yet, the user's relevance criteria have not changed much despite the change in search environment.

• Safety and Health at Work
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• v.7 no.3
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• pp.185-193
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• 2016

Background: Management and workers in small and medium-sized enterprises (SMEs) often find it hard to comprehend the requirements related to controlling risks due to exposure to substances. An intervention study was set up in order to support 45 SMEs in improving the management of the risks of occupational exposure to chemicals, and in using the control banding tool and exposure model Stoffenmanager in this process. Methods: A 2-year intervention study was carried out, in which a mix of individual and collective training and support was offered, and baseline and effect measurements were carried out by means of structured interviews, in order to measure progress made. A seven-phase implementation evolutionary ladder was used for this purpose. Success and failure factors were identified by means of company visits and structured interviews. Results: Most companies clearly moved upwards on the implementation evolutionary ladder; 76% of the companies by at least one phase, and 62% by at least two phases. Success and failure factors were described. Conclusion: Active training and coaching helped the participating companies to improve their chemical risk management, and to avoid making mistakes when using and applying Stoffenmanager. The use of validated tools embedded in a community platform appears to support companies to organize and structure their chemical risk management in a business-wise manner, but much depends upon motivated occupational health and safety (OHS) professionals, management support, and willingness to invest time and means.

• Journal of Welding and Joining
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• v.27 no.3
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• pp.92-96
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• 2009

Metallic sandwich plate has many good properties such as high specific stiffness, high specific strength, good impact absorptivity, effective thermal insulation and soundproofing. In our study, a new bonding method, 3-layer roll projection welding, is introduced to fabricate the metallic sandwich plate. The new method uses a pair of roll electrodes like the seam welding, and projection welding is made at two internal interfaces of the 3-layer weldment consisting of a structured inner sheet and a pair of skin sheets. During the welding process, skin sheet temperature are measured to produce metallic sandwich plate with uniform and good quality. But it is difficult to observe or measure the temperature at the welding points during welding process because the welding points exist at the internal interfaces. Therefore FEM numerical analysis using ABAQUS is conducted to estimate the generated heat at the welding points with different welding conditions.

• Journal of Korean Society on Water Environment
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• v.33 no.2
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• pp.149-159
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• 2017

After the artificial barrage was constructed in 1990s, the Geumgang estuary has been experiencing considerable changes in nature as well as in socioeconomic and culture in the vicinity villages. In order to understand how the change of estuarine environment bring about conflicts among the local communities, and resolve the conflicts, the research investigated the causes of the conflicts in the Geumgang estuary using in-depth and semi-structured interview method. 100 local people who have lived in the vicinity of Geumgang estuary for more than 30 years were selected for the interviews. Results of the research shows that local people's jobs determine the opinions about the estuary barrage and the way of estuarine management. Understanding environmental change and local conflicts helps to develop a sustainable and integrated estuary management system in the region.