• Journal of Welding and Joining
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• v.20 no.6
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• pp.816-822
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• 2002

Laser flash method have been widely used for practical measuring method of thermal diffusivity. And it can be used for measurement of non-conductive materials as well as conductive materials and also for measuring thermal multi-properties. We have analyzed effects of error occurring during measurement of thermal properties in order to enhance measuring accuracy. Also we have studied delay time between measurement starting time with synchronizing signal and laser oscillating time, because it is important that measuring a time to rise temperature of specimen from room temperature to a half of measuring temperature at measuring a thermal diffusivity by laser flash method. We could reduce non-uniform heating error from non-uniform energy distribution by developing 3D uniformizer to eliminate non-uniform heating error. We have measured thermal diffusivities of POCO AXM-5Q1 and Glassy-Carbon which are standard specimen of NIST(USA) and candidate standard specimen of NRLM(japan) respectively for laser flash method. Maximum error fell within 2% for POCO AXM-5Ql gaphite and 2% for Glassy-Carbon. Those results showed error decreasing methods were effective.

• Journal of the Korean Society of Propulsion Engineers
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• v.6 no.1
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• pp.39-46
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• 2002

It is very difficult to measure an exact thrust in liquid rocket engine compared to solid rocket motor, however it is very important to estimate a performance of engine for developing rockets. To get a good result, we have to concern about errors of measurement and find a method of calibration. In this research, we developed new thrust measurement system for liquid rocket engine.

• Proceedings of the IEEK Conference
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• 2001.06e
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• pp.81-84
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• 2001

This paper presents a potable bio-signal measurement system using Bluetooth for the 24-hours continuous health state monitoring of the elderly and the disabled. The measurement system has the functions of acquisition of various bio-signals, wireless data transmission and adjustment of parameters such as gain and cut-off frequency. This measurement system is designed according to the international specifications of the recommendation of AAMI (Association for the Advancement of Medical Instrumentation). The design targets of the developing system about volume and power consumption are 20x30x5mm$^3$ and 8mW.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.61 no.8
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• pp.1216-1220
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• 2012

The current collection between pantograph and contact wire is a more critical component for need to train speed up in electric railway. The basic purpose of this paper is to establish a measure of determining arc by developing an arc detector assessment system. The system was designed under conditions of EN 50317 and simulations were conducted using the developed device. According to the results, it was possible to conduct certification tests following regulations of international standards. To check the validity of our approach for the intended application, we analysis contact loss of catenary system using developed arcing measurement system in Korea. The proposed arcing measurement system is expected to enhance precision of current collection quality performance assessment methods at high-speed lines and conventional lines.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2004.11a
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• pp.685-688
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• 2004

This paper addresses the study on developing the angular vibration calibration system which requires the highly accurate measurement technique of the amplitude and period of an oscillating angular motion. Two developed models for the low and high frequency ranges are introduced and their main features are also compared. In addition to the angular vibration exciters, a new measurement method, referred to the 'equi-angle sampling method', is proposed and its theoretical backgrounds are introduced. The proposed method is shown to provide much less measurement uncertainty, compared the fringe counting method. Experimental results demonstrate what amount of angular vibration amplitude measurement uncertainty is improved by suing the proposed equi-angle sampling method.

• Journal of Navigation and Port Research
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• v.32 no.2
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• pp.141-148
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• 2008

This paper is structured into three main parts and a conclusion. The main section provide definitions of efficiency, effectiveness and performance in terms of the distribution channel, followed by a review of related performance measurement, before discussing difficulties of measurement. According to the theoretical approach, it appears that key theroretical issues are centered around customer service, logistics excellence, time compression, the use of IT, and a move towards integrated logistics. The empirical approach shows that in the past, various financial performance indicators were regarded as relevant management information. However, today, management needs additional performance indicators. Therefore, external assessments of effectiveness must be performed to measure customers' satisfaction with the physical flow of product through the distribution channel network. So, what is needed is to take previous normative and explorative research and progress through a framework by developing valid measures of distribution channel's effectiveness and efficiency, and identifying research methodologies suited to the data collection requirements.

• The Transactions of the Korean Institute of Electrical Engineers D
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• v.53 no.5
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• pp.345-352
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• 2004

Currently, high data rate PLC(Power Line Communications), up to 100 Mbps, which use frequency bandwidth between 2 MHz and 30 MHz is investigated very hard, and commercial PLC modem for low voltage powerline network (indoor) is coming soon into communication market. For the purpose of developing a fit communication system which has little distortion of signal and attenuation, it is surely necessary to know about channel environments of powerline. Especially, the impedance measurement of the powerline and impedance matching are very important. As is known, since medium-voltage powerline (22.9 ㎸) is still working, it is not so simple to measure the powerline impedance. In our study, a portable impedance measurement equipment is developed. It consists of coupling capacitor, a drain coil and impedance matching transformer. The equipment is easily connected to medium voltage line and impedance of power line is measured using a network analyzer. Also, measurement results are used for impedance matching of PLC signal. In fact, matching transformer with several different impedances are used. The matching transformer is connected between coupling capacitor and signal port. In this paper, the developed portable impedance measurement equipment and impedance measurement results are presented. Also impedance matching technique using matching transformers will be explained. We showed the result of the improved performance by the impedance matching.

• Journal of Internet Computing and Services
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• v.23 no.3
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• pp.111-123
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• 2022

Artificial intelligence, which is developing as the core of an intelligent information society, is bringing convenience and positive life changes to humans. However, with the development of artificial intelligence, human rights and property are threatened, and ethical problems are increasing, so alternatives are needed accordingly. In this study, the most controversial artificial intelligence ethics problem in the dysfunction of artificial intelligence was aimed at researching and developing artificial intelligence ethical measurement indicators to protect human personality rights and property first under artificial intelligence ethical principles and components. In order to research and develop artificial intelligence ethics measurement indicators, various related literature, focus group interview(FGI), and Delphi surveys were conducted to derive 43 items of ethics measurement indicators. By survey and statistical analysis, 40 items of artificial intelligence ethics measurement indicators were confirmed and proposed through descriptive statistics analysis, reliability analysis, and correlation analysis for ethical measurement indicators. The proposed artificial intelligence ethics measurement indicators can be used for artificial intelligence design, development, education, authentication, operation, and standardization, and can contribute to the development of safe and reliable artificial intelligence.

• Convergence Security Journal
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• v.14 no.4
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• pp.41-53
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• 2014

In order to achieve efficient and effective organizational information security objectives, for the level of information security to accurately evaluation and direction for improving that performance evaluation index and method of measurement for information security outcomes are needed. For information security activities of domestic companies to measure the performance or effectiveness, that standard method of measuring and the available evaluation Index are insufficient. company is difficult to investment for information security budget. Therefore, the purpose of this study was developing of performance evaluation index and method of measurement for information security outcomes applying BSC available in the company. The results of this study that companies can determine the level of information security itself. Analysis of the information security status and the strategy establishment of the information security investment can be applied.

• IEIE Transactions on Smart Processing and Computing
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• v.3 no.1
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• pp.10-18
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• 2014

From the perspective of reducing the sampling cost of color images at high resolution, block-based compressive sensing (CS) has attracted considerable attention as a promising alternative to conventional Nyquist/Shannon sampling. On the other hand, for storing/transmitting applications, CS requires a very efficient way of representing the measurement data in terms of data volume. This paper addresses this problem by developing a measurement-coding method with the proposed customized Huffman coding. In addition, by noting the difference in visual importance between the luma and chroma channels, this paper proposes measurement coding in YCbCr space rather than in conventional RGB color space for better rate allocation. Furthermore, as the proper use of the image property in pursuing smoothness improves the CS recovery, this paper proposes the integration of a low pass filter to the CS recovery of color images, which is the block-based ${\ell}_{20}$-norm minimization. The proposed coding scheme shows considerable gain compared to conventional measurement coding.