• Proceedings of the Korea Concrete Institute Conference
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• 2000.10a
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• pp.75-80
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• 2000

Evaluation method of seismic performance has mainly used elastic spectrum analysis. This method has simplicity of analysis but deficiency of accuracy. And evaluation method of seismic performance using inelastic dynamic analysis reflects accurately inelasticity of material but hardly reflects site effects. This study suggested evaluation scheme of seismic performance for bridge structure using capacity spectrum method applied inelastic static analysis and standard design response spectrum of Korea Standard Specification for Highway Bridge. Two results, capacity spectrum method and inelastic dynamic analysis method, are very similar. As a result, this study appropriately supply both simplicity of analysis and accuracy of result.

• 대한공업교육학회지
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• v.33 no.1
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• pp.92-113
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• 2008

The purpose of this study is to develop a standard for right performance assessment instrument for the practice CNC Lathe of work machine subject in technical high school. In this study, we developed the standard performance assessment instrument for the practice CNC Lathe through collecting and analyzing the standard performance assessment instrument of CNC Lathe from 13 technical high schools (11 public schools and 2 private schools). The developed standard of performance assessment instrument for the practice CNC Lathe is verified by getting proper estimation from 26 teachers in technical high schools (2 teachers from each school) who are taking charge of CNC Lathe practice, and mean value between 3.77 and 4.77 is very high in validity. The characteristics of assessment instrument developed in this study are as following. First, the standard of performance assessment instrument is redeveloped to evaluate the cognitive domain and affective domain as well as psychomotor domain of technical high school students. Second, the estimation field for practice subject is segmented for all practice processes and intends to do objective estimation which can be carried out by both teachers and students, not only teachers. Third, the developed standard of performance assessment instrument for the practice CNC Lathe has high validity and truthfulness because it is monitored by teachers who are teaching in technical high school.

• Journal of Information Technology Services
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• v.19 no.3
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• pp.139-149
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• 2020

There are now many different commercial weather sensors suitable for smart farms, and various smart farm devices are being developed and distributed by companies participating in the government-led smart farm expansion project. However, most do not comply with standard specifications and are therefore limited to use in smart farms. This paper proposed the connecting structure of operating non-standard node devices in smart farms following standard specifications supporting smart greenhouse. This connecting structure was proposed as both a virtual node module method and a virtual node wrapper method. In addition, the SoftFarm2.0 system was experimentally operated to analyze the performance of the implementation of the two methods. SoftFarm2.0 system complies with the standard specifications and supports non-standard smart farm devices. According to the analysis results, both methods do not significantly affect performance in the operation of the smart farm. Therefore, it would be good to select and implement the method suitable for each non-standard smart farm device considering environmental constraints such as power, space, distance of communication between the gateway and the node of the smart farm, and software openness. This will greatly contribute to the spread of smart farms by maximizing deployment cost savings.

• Fire Science and Engineering
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• v.26 no.5
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• pp.85-91
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• 2012

This paper analyzed firefighting officers' use situations such as the use time, maximum working pressure, hose diameter, etc. of fire pumps at fire sites and carried out various performance tests by pressures, hose diameters and quantities of fire pumps based on its results because the waterproof performance criterion for a fire pump installed in a fire engine is different from the operation situations at the site and is not clearly prescribed. As a result of site survey, the site uses a higher pressure than the standard water discharge pressure (0.85 MPa) or the high-pressure water discharge pressure (1.4 MPa) prescribed by the approval Standard of the fire pump performance on fire truck. In addition, as a result of pump performance test, the discharged water flow rate, water discharge pressure, etc. was measured to be very different from the currently prescribed the approval standard depending on the hose diameter and firefighting nozzle, so the result of this study proposes a new standard.

• Journal of the Korean Operations Research and Management Science Society
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• v.38 no.4
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• pp.35-52
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• 2013

Markowitz's portfolio selection model is used to construct an optimal portfolio which has minimum variance, while satisfying a minimum required expected return. The model uses estimators based on analysis of historical data to estimate the returns, standard deviations, and correlation coefficients of individual stocks being considered for investment. However, due to the inaccuracies involved in estimations, the true optimality of a portfolio constructed using the model is questionable. To investigate the effect of estimation inaccuracy on actual portfolio performance, we study the changes in a portfolio's realized return and standard deviation as the accuracy of the estimations for each stock's return, standard deviation, and correlation coefficient is increased. Furthermore, we empirically analyze the portfolio's performance by comparing it with the performance of active mutual funds that are being traded in the Korean stock market and the KOSPI benchmark index, in terms of portfolio returns, standard deviations of returns, and Sharpe ratios. Our results suggest that, among the three input parameters, the accuracy of the estimated returns of individual stocks has the largest effect on performance, while the accuracy of the estimates of the standard deviation of each stock's returns and the correlation coefficient between different stocks have smaller effects. In addition, it is shown that even a small increase in the accuracy of the estimated return of individual stocks improves the portfolio's performance substantially, suggesting that Markowitz's model can be more effectively applied in real-life investments with just an incremental effort to increase estimation accuracy.

• Journal of the Institute of Electronics Engineers of Korea CI
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• v.44 no.3
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• pp.108-123
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• 2007

As H.264/AVC standard has proven to be a key technology of multimedia application, many researches to improve H.264/AVC standard are actively conducted. Those researches are conducted in various ways such as algorithm analysis and improvement or structure enhancement for reducing bottlenecks of performance. Even though targets and directions of those studies are not the same, performance of H.264/AVC standard is commonly analyzed in the early phase. In analysis phase, potential problems with H.264/AVC standard are identified and the most critical problem which has serious effects on performance is determined. Therefore, analysis phase is one of the important steps to decide overall directions and targets of the research. This research proposes a mathematical model which can be used in the early performance analysis phase to estimate performance in conducting research of improving the performance of H.264/AVC Baseline Profile decoder. The proposed model is designed by considering many variables of H.264/AVC decoder operation so that it is easy to predict its performance according to changes in each element.

• Proceedings of the Korea Concrete Institute Conference
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• 2002.05a
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• pp.861-866
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• 2002

This manuscript introduces the Capacity Design Methodology in the Building Standard Law of Japan revised at 2000, June. The Building Standard Law of Japan was revised into the performance-based design format following the trend of international. The structural performance was evaluated for two limiting states; soundness limit state and safety limit state. The design seismic forces were determined on taking into consideration (a)the properties of the planned building, (b)amplification by local surfaces geology, and (c)soil-structure interaction.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2001.05a
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• pp.226-229
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• 2001

Recently the impact sound insulation performance is regarded as one of the most import factors in determining the quality of housing environment. In order to reduce the impact sound level transmitted through the floors and structures, establishing the standard level of impact sound insulation performance is needed. In this consideration, The effecting facts for the standard insulation level is reviewed.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.67 no.3
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• pp.479-484
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• 2018

This paper describes domestic technical standard of Photovoltaic(PV) PCS(Power Conditioning Systems)-Characteristics of the utility interface. This standard tests utility compatibility and personnel safety and equipment protection of PV inverter performance functions. Especially utility compatibility part includes test items of 1)voltage, current and frequency, 2)normal voltage operating range, 3)DC injection, 4)normal frequency operating range, 5)harmonics and 6)waveform distortion, 7)power factor of PV inverter. Therefore in this paper each test item of domestic technical standard is studied and analyzed and finally full tested by PV inverter performance function.

• Journal of the Earthquake Engineering Society of Korea
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• v.18 no.5
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• pp.231-240
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• 2014

This study reviews the status and validity of seismic design criteria (SDC) for major facilities in Korea, which are composed of performance criteria and technical standard. Various facilities with different seismic design response spectra are analyzed to identify their seismic performance and necessity of eventual retrofit. The results are used to derive improvement directions of SDC. It is also concluded that the technical standard should be improved after the revision of the performance criteria.