• Journal of the Korean Solar Energy Society
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• v.30 no.1
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• pp.7-12
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• 2010

As many grid-connected photovoltaic power conditioning systems (PVPCS)are installed in many residential areas simultaneously, these have raised potential problems of network protection on electrical power system. One of the numerous problems is an Islanding phenomenon. In this paper, active frequency drift (AFD) method, one of the anti-islanding methods which is analyzed by current magnitude compensation and calculation of the fundamental component. Both harmonic component and RMS value of the output current for THD analysis are provided and verified by simulation.

• Journal of the Korean Solar Energy Society
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• v.29 no.6
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• pp.75-80
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• 2009

Recently, as the grid-connected photovoltaic power conditioning systems (PVPCS) are installed in many residential areas, these have raised potential problems of network protection on electrical power system. One of the numerous problems is an Islanding phenomenon. In this paper, active frequency drift (AFD) method, one of the anti-islanding methods which is analyzed by current magnitude compensation and calculation of RMS value of the output power is proposed and verified by simulation.

• ETRI Journal
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• v.20 no.2
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• pp.149-170
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• 1998

Between a wide range of distributed applications, this work is particularly focused on those applications which allow a group of persons, who are geographically distributed, to interact and cooperate exchanging different kind of information in order to realize group activities in a common work environment. In this paper we realized a study of this kind of applications to identify general and functional characteristics which will then enable us to determine their communication requirements. Also, we analyzed the existent support architectures to examine whether they support multimedia cooperative applications. Based on the results of analysis, we proposed a set of communication functions needed additionally to support these applications, using the ODP(Open Distributed Processing) modelling concepts, rules and view points as our global design methodology.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.27 no.2
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• pp.44-51
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• 2004

Competition of Business firms has become serious domestically and internationally. No one can deny that cooperation and peace between labour and management are essentially necessary in this seriously competitive business world and will form continuous national economic development. This paper is interested in consumer's cognizance of business firm, business CEO, and labor. The attributes of consumer dealt with are gender, education level, etc. We showed consumer's cognizance as forms of hypotheses, tested them, and found many statistically significant facts, and suggested their implication. It can be said that our research results can be utilized as good information and for judgement and decision for constructing cooperative and peaceful labour and management relation.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.19 no.38
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• pp.51-60
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• 1996

There is a general challenge offered to the field of engineering economics by the introduction of advanced technologies. A survey of the existing literature on evaluation of advanced information and manufacturing system indicate that the traditional approaches are inadequate for economic evaluation techniques used in its appraisal, difficulty in evaluating the potential benefits and criteria used to assess management performance. In this paper, an attempt has been made to overcome the above deficiencies by presenting an approach to account for the justification and selection of the Local Area Network(LAN) architectures. This is based on the Analytic Hierarchy Process(AHP) and is capable of taking into account many intangible factors as well. The usefulness of the proposed approach is demonstrated through a case situation and sensitivity analysis. Finally, some research directions for future work are identified.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.32 no.1
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• pp.20-25
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• 2009

Mahalanobis Taguchi System (MTS) is a pattern information technology, which has been used in different diagnostic applications to make quantitative decisions by constructing a multivariate measurement scale using data analytic methods without any assumption regarding statistical distribution. The MTS performs Taguchi's fractional factorial design based on the Mahahlanobis Distance (MS) as a performance metric. In this work, MTS is used for analyzing Wisconsin Breast Cancer data which has ten attributes. Ten different tests are conducted for the data to determine if the patient has cancer or not. Also, MTS is used for reducing the number of test to define the relationship between each attribute and diagnosis result. The accuracy of diagnosis is compare with two different previous research.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.32 no.1
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• pp.61-66
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• 2009

Usability study of the CU Medical "i-PAD" AED was conducted to validate the usability of the device, primarily focused on the trained user as well as the utility of the training material. Comparing these results of the trained participants to those obtained by Callejas et al. (2004), who studied video-trained users of two commercially available Philips AEDs (FR2 and HS1) using a male manikin only, the participants in this study were more successful (100% vs. 85.7%-FR2 vs. 88.9%-HS1) and faster to shock (58.5s-i-PAD vs. 91s-FR2 vs. 90s-HS1). While the focus of this study was on validating ease of use for trained bystanders, the results of the untrained condition showed that, from a usability perspective, these devices perform as well as any other AEDs already approved and available for purchase for untrained bystander use, as evidenced by the comparison to various published research results.

• Journal of Internet Computing and Services
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• v.11 no.2
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• pp.165-172
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• 2010

In Web-based learning systems, the techniques, as self-regulated learning, self-directed learning, are used to improve the effect of learner's study. These techniques are methods considering learner's study level but to consider the learner's study ability properly, the tailored course for learner should be applied. In this research, the learning system considering learner's study ability was proposed. To decide a learner's study ability, IRT(Item Response Theory) was applied and learning contents and question items were developed and applied by the degree of difficulty.

• Journal of Korean Society for Quality Management
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• v.23 no.3
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• pp.33-44
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• 1995

This paper presents an automated visual inspection system for the electronic parts manufacturing process. In this system, a statistical process control (SPC) method is integrated into the automated inspection method on a real time base. It shows how the collected data can be analyzed with the SPC to provide process information. Also presented are studies of subpixel image processing technology to improve the accuracy of parts measurements, and the cumulative-sum (CUSUM) control chart for fraction defectives. An application of the developed system to connector manufacturing process as a part of computer integrated manufacturing (CIM) is presented.

• Proceedings of the IEEK Conference
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• 2003.07e
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• pp.2315-2318
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• 2003

The Wavelet Transform has been applied in mathematics and computer sciences. Numerous studies have proven its advantages in image processing and data compression, and have made it a basic encoding technique in data compression standards like JPEG2000 and MPEG-4. Software implementations of the Discrete Wavelet Transform (DWT) appears to be the performance bottleneck in real-time systems in terms of performance. And hardware implementations are not flexible. Therefore, FPGA implementations of the DWT has been a topic of recent research. The goal of this thesis is to investigate of FPGA implementations of the DWT Processor for image compression applications. The DWT processor design is based on the Lifting Based Wavelet Transform Scheme, which is a fast implementation of the DWT The design uses various techniques. The DWT Processor was simulated and implemented in a FLEX FPGA platform of Altera