• Transactions of the Korean Society of Mechanical Engineers A
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• v.29 no.12 s.243
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• pp.1653-1659
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• 2005

In this study, the performance of a DPRMs is evaluated and the measurement precision for the pile driving is presented. The DPRMs is a visual-measurement system for the pile rebound and the penetration movement using a high speed line-scan camera. The DPRMs generates the measurement deviation. It is caused by the strong impact for the pile driving. To reduce it, the vibration signal analysis about the pile driving is performed. As a result, it is confirmed that the tilting frequency of a camera-tripod structure corresponding to excitation frequency range of the ground is under 40Hz. Through the structure modification, the camera-tripod structure is redesigned to the model being free itself from the excitation frequency range of the ground. By the verification testing about the improvement effects, it is inspected that the tilting and measurement deviation of the redesigned DPRMs are reduced.

• Knowledge Management Research
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• v.21 no.4
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• pp.243-263
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• 2020

The purpose of this study is to propose the performance measurement model for open big data platform. In order to develop the performance measurement model, we have integrated big data reference architecture(NIST 2018) with performance prism model(Neely et al. 2001) in the platform perspective of open big data. Our proposed model consists of five key building blocks for measuring performance of open data platform as follows: stakeholder contribution, big data governance capabilities, big data service capabilities, big data IT capabilities, and stakeholder satisfaction. In addition, our proposed model have twenty four evaluation indices and seventy five measurement items. We believe that our model could offer both research and practical implications for relevant research.

• Journal of Power System Engineering
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• v.11 no.1
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• pp.28-32
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• 2007

This research proposed that development of wireless condition monitoring system using WLAN network. It offers the prospect of improved performance that removed a current a coaxial cable and reduced overall cost of condition monitoring. Recently, there is an interesting concern for wireless system as an infrastructure technology construct ubiquitous computing environment in the future. High performance computing board makes minimization with integrate of a various functions which support wireless LAN network. Instead of wired coaxial cable using measurement system in industry, wireless LAN network assists industry automation and engineer's convenience. Developed system adapted wireless LAN network on shipboard with engine room and deck house, it also executes wireless measurement test on 8500TEU containership.

• Proceedings of the KIEE Conference
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• 2003.11b
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• pp.95-98
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• 2003

Computer aided simulation is becoming an essential part in planning, design, and operation of railway systems. To determine the adequate performance and specification of railway system, it is necessary to calculate rolling stock's performance such as distance, speed, power etc when train's running. This paper presents result of train performance simulation using the program that developed in advance for Korea high speed train. To verify result of simulation, we have developed measurement system and compared simulation result with experiment data.

• Journal of the Korean Data and Information Science Society
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• v.19 no.4
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• pp.1123-1131
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• 2008

A considerable amount of research has focused on the dimensionality of service failure and recovery construct. This paper is focused on service failure and recovery in the Korean native cattle and imported beef restaurant industry in the Korea. So, this paper has adapted Kau and Loh's Service recovery measurement scale so that restaurant managers can use it to determine how customers perceive the service quality in Korean native cattle beef restaurant and imported beef restaurant. The purpose of this research is to test the difference in pre-purchase expectation and post-purchase actual performance of 4 dimensions between the restaurants that sell the beef of Korean native cattle and imported cattle. The paired t -test is used to test difference of pre-purchase expectation and post-purchase actual performance for service recovery measurement scale's 4 dimensions of the 2 restaurant types. But, there is significant difference between pre-purchase expectation and post-purchase actual performance in the 2 restaurant types.

• Aerospace Engineering and Technology
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• v.5 no.2
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• pp.27-36
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• 2006

This paper describes the performance test procedures and results of NRSB-1M and NRSB-2M Not only aerodynamic performance test but also sound measurement test were performed for the small-scaled blades in the ground Total thrusts and torques of the rotor were measured using rotating balance for aerodynamic performance test. Sound pressure levels were measured using microphone in 1.64D distance for sound measurement test. Non-dimensionalized test data are compared and analyzed. Consequently, It was confirmed that NRSB-2 was better than NRSB-1.

• Journal of the Society of Naval Architects of Korea
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• v.56 no.3
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• pp.242-250
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• 2019

The speed and power performance of a ship is not only a guarantee issue between the ship owner and the ship-yard, but also is related with the Energy Efficiency Design Index (EEDI) regulation. Recently, International Organization for Standardization (ISO) published the procedure of the measurement and assessment for ship speed and power at sea trial. The results of speed and power performance measured in actual sea condition must inevitably include various uncertainty factors. In this study, the influence for systematic error of shaft power measurement system was examined using the Monte Carlo simulation. It is found that the expanded uncertainty of speed and power performance is approximately ${\pm}1.2%$ at the 95% confidence level(k=2) and most of the uncertainty factor is attributed to shaft torque measurement system.

• Transactions of the Korean Society for Noise and Vibration Engineering
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• v.23 no.9
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• pp.789-796
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• 2013

Vibration measurements using image processing have been studied by many researchers as it can remotely measure vibration displacements at multiple points simultaneously. It is difficult, however, to obtain accurate displacement from the measured image signals because the resolution of image data is dependent on camera performance and normally lower than that of vibration transducer directly measured. This paper suggests the enhanced technique for vibration displacement measurement by applying the expected value of edge probability distribution to the varying pixel points in the image. The method can both increase the resolution limit of camera image and decrease the measurement errors. The working performance of the proposed technique is verified applying to the vibration measurement of a rotating machine.

• Proceedings of the IEEK Conference
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• 2003.11a
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• pp.493-496
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• 2003

Recently, Ryu et al. proposed a multiple target DOA tracking algorithm, which has good features that it has no data association problem and simple structure. But its performance is seriously degraded in the low signal-to-noise ratio. In this paper, a measurement fusion method is presented based on ML(Maximum Likelihood), and the new DOA tracking algorithm is proposed by incorporating the presented fusion method into Ryu's algorithm. The proposed algorithm has a better tracking performance than that of Ryu's algorithm, and it sustains the good features of Ryu's algorithm.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.27 no.9
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• pp.83-89
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• 2013

Power distribution system has been changed from radial system to closed loop or mesh system due to connection of distributed generation growth. Data from distribution equipments which are installed at distribution line is required to be accurate for the performance of DMS(Distribution Management System). This paper analyzes the voltage measurement data from distribution equipment. However, the results of the analysis are confirmed to have some errors in voltage measurement data from distribution equipment. These errors come from aging of voltage sensor in distribution equipment and inaccurate data transfer to FRTU(feeder remote terminal unit) through the controller. The main problem is that the voltage measurement data of distribution equipment can not be assessed after it's first installation at the distribution line. The voltage measurement accuracy assessment system is to assess the voltage measurement data from distribution equipment on hot-line. This study had a field test to verify the performance of system.