• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.19 no.12
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• pp.1128-1133
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• 2006

The most important thing to secure safety and reliability of railway vehicles is to verify performance characteristics of equipments, and related companies or research institutes had many efforts to verify performances and functions of equipments synthetically and efficiently. KHST(Korean High Speed Train) has been developed by KRRI (Korea Railroad Research Institute). An electric railway system is composed of high-tech subsystems, among which main electric equipment such as transformers and converter are critical components determining the performance of rolling stock. We developed a measurement system for on-line test and evaluation of performances of KHST. The measurement system is composed of software part and hardware part. Perfect interface between multi-users is possible. A new method to measure temperature was applied to the ]measurement system. By using the system, fault diagnosis and performance evaluation of electric equipment in Korean High Speed Train was conducted during test running.

• Journal of Auto-vehicle Safety Association
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• v.7 no.2
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• pp.32-38
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• 2015

A sine with dwell test is well known as a test scenario for evaluation of performance of electronic stability control(ESC) on passenger vehicles and heavy commercial vehicles. However, when it comes to ESC for medium commercial vehicles, the test scenario has not been established yet. In this paper, the sine with dwell test was modified considering characteristics of medium commercial vehicles. The three main modifications of the original test scenario are the steering angle level, steering frequency, and loading condition of the vehicle. These modifications are derived from simulation study for different medium commercial vehicles. From simulation study, it was shown that the ESC system for medium commercial vehicle is objectively evaluated by the proposed test scenario. A clear improvement on vehicle stability was seen in the results when ESC system was used.

• Journal of the Korea Society of Computer and Information
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• v.4 no.4
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• pp.226-235
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• 1999

The purpose of this study is to present models for evaluation and selection of Electronic Commerce systems suppliers. The Major concern of management is that almost all decision problems have multiple, usually conflicting, criteria. The fuzzified multi-objective programming models are given to accommodate the aspiration level and satisfaction level of decision makers. The proposed models are classified into three types, that is, min-operator. additive and pre-emptive priority. Numerical Examples illustrating each type of model are presented and the implications of these models are discussed.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.26 no.8
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• pp.624-628
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• 2013

With the recent development of less-costly uncooled detector technology, expensive optics are among the remaining significant cost drivers in the thermography camera. As a potential solution to this problem, the fabrication of IR lenses using chalcogenide glass has been studied in recent years. We report on the molding and evaluation of a ultra-precision chalcogenide-glass lens for the thermography camera for body-temperature monitoring. In addition, we fabricated prototype thermography camera using the chalcogenide-glass lens and obtained the thermal image from the camera. In this work, it was found out that thermography camera discerned body-temperature between 20 and $50^{\circ}C$ through the analysis of thermal image. It is confirmed that thermography camera using the chalcogenide-glass lens is applicable to the body-temperature monitoring system.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.23 no.2
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• pp.103-117
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• 2010

In this study, the heart rate variability(HRV) signal of operating patient was acquired according to anesthesia progress and identified to evaluation possibility of depth of anesthesia in each anesthesia stage. The HRV signal was analyzed time-frequency domain applied to Wigner-Ville distribution method, the characteristic parameters were extracted for evaluation of depth of anesthesia in each anesthesia stage. The progress of general anesthesia was divided into the states of pre-operation, induction of anesthesia, operation, awaking and post-operation.

• Journal of Information Technology Services
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• v.1 no.1
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• pp.17-27
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• 2002

Buyer-carts to support the purchasing process in the B2B EC platform, can be categorized as s-cart, i-cart, and b-cart depending upon its residing sites : seller, intermediary, and buyer sites. In this paper, after proposing the desired features of buyer-carts in B2B EC as identification, collection, trashing, ordering, payment, tracking, recording, purchasing decision support, and transmission of records to e-procurement systems, we try to analyze each buyer-cart qualitatively from such viewpoints. Moreover, we propose an efficiency evaluation model for quantitative analysis. By setting variables from interview of employees in 30 listed companies In Korea, we try to evaluate the efficiency of buyer-carts in B2B EC. From this paper, we show that the b-cart platform is more efficient than other buyer-carts especially in B2B EC.

• Journal of electromagnetic engineering and science
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• v.19 no.1
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• pp.13-19
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• 2019

This paper proposes a systematic method for estimating detection performances of a frequency-modulated continuous wave radar using electromagnetic simulations. The proposed systematic method includes a radar system simulator that can obtain range-Doppler images using the electromagnetic (EM) simulations in conjunction with a test setup employed for performance evaluation of multiple targets at different velocities in a traffic environment. This method is then applied for optimizing the half-power beamwidths of the antenna array using an evaluation metric defined to improve the detection strengths for the multiple targets. The optimized antenna has vertical and horizontal half-power beam widths of $10^{\circ}$ and $60^{\circ}$, respectively. The results confirm that that the proposed systematic method is suitable to improve the radar detection performance with the enhanced radar-Doppler images.

• Journal of Engineering Education Research
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• v.23 no.6
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• pp.68-76
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• 2020

This study presents a teaching model to increase the participation and interest, and to improve their understanding of physical concepts of first-year engineering students taking physics(2) course at a three-year college. In the class, a team task solution based on teamwork and a peer learning method through questions and answers between participants in each team were applied so that learners could actively participate in the class to discuss and present. We examined how the activities of each team affected students' interest in subjects, motivation to learn, and the degree of understanding of physical concepts. In the team activity, students were able to actively participate through emotional sharing between learners and free questions and explanations, and it was confirmed that academic achievement was improved by comparing the final exam evaluation results with the evaluation results of the previous three years.

• The Journal of the Korea institute of electronic communication sciences
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• v.18 no.3
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• pp.441-448
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• 2023

The quality of the casting process generates the largest source of defects in the manufacturing process, so its management is a key factor in productivity and quality evaluation. Based on the results of factor analysis, correlation analysis, and regression analysis with process data, this study aims to optimize the machine learning model to reduce the defect rate and verify the data suitability for smart factories.

• Korean Management Science Review
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• v.23 no.2
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• pp.93-107
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• 2006

This paper attempts to improve the typical DEA model that is often used as a performance evaluation method for service firms. The after-sales service system in a Korean electronic company is chosen as a sample case. The performance evaluation method currently practiced in the firm was reviewed and some critical issues of the current method were discussed. DEA model would be considered a solution for solving those Issues. However, typical DEA models has various drawbacks in determining the weights over evaluation criteria. Proposed is the priority-constrained DEA model that accommodates the strategic Importance of each evaluation criterion. The results of the proposed model are compared with those of typical DEA models. It is shown that the priority-constrained DEA model is superior to the others in terms of evaluation quality.