• 대한조선학회논문집
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• 제56권3호
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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.

• 전기의세계
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• 제26권6호
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• pp.66-71
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• 1977

In this paper a method is presented for the optimal control of a nuclear reactor at equilibrium state by use of a digital computer. Using the optimal control theory, we formulate the control problem of the reactor as a discrete-time linear regulator problem. A quadratic performance index is defined. The effects of choosing different performance index weighting matrices to the feedback gain matrix and reactor transient responses are studied for the deterministic optimal control with all state variables accessible to measurement.

• 한국건설관리학회:학술대회논문집
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• 한국건설관리학회 2008년도 정기학술발표대회 논문집
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• pp.497-500
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• 2008

최근 국내외에서 도시재생사업이 활발히 진행되고 있다. 이러한 도시재생사업은 사업주체 및 이해관계자가 다양하고, 복잡하며, 대규모의 긴 생애주기를 가지고 있다. 또한 대부분 입체 복합공간 개발 형태의 메가프로젝트라는 특징을 나타내고 있다. 이러한 대규모의 도시재생사업은 사업수행과정에서 많은 위험요인들이 존재하며, 그와 더불어 효율적이고 지속적인 성과관리가 필요하다. 그러나 국내의 성과관리는 건설업의 특성을 반영하지 못하고 있으며, 위험과 연계된 연구는 미비하다. 그래서 본 연구는 효율적인 성과관리를 위한 위험과 연계된 성과측정지표를 도출하기 위한 기초연구로 맵핑(mapping)을 통해 성과측정을 위한 성과지표와 위험요인을 연계하는 방법을 제시하고자 한다.

• 산업경영시스템학회지
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• 제32권1호
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• pp.111-116
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• 2009

Process capability indices have been widely used in manufacturing industries to provide a quantitative measure of process performance. PCIs have been developed to represent process capability more exactly. In the previous studies, only one designated location on each part has been measured. But multiple measurement locations on each part are required to calculate the reliable process capability. In this paper, we propose a new process capability index dealing the multiple measurement locations on each part. Also we showed the relationship between the new index and sigma level according to the number of measurement locations.

• 한국소음진동공학회논문집
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• 제24권1호
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• pp.35-44
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• 2014

Sound pressure levels in the receiving room while testing airborne sound insulation performance are varied by the measuring points. This may increase the measurement error, then decrease the measurement reliability. With this reason the research has carried out on the method to reduce deviations of sound pressure level in the ISO type rectangular laboratory focusing on the measurement of airborne sound insulation performance. Tests were made to see the effect of sound absorption in the receiving room, loudspeaker locations, microphones locations and flanking transmission path. Consequently, it was resulted that sound absorption in the receiving room and the loudspeaker location have influence on the sound level deviations especially in the low frequency. The microphone location was very important to get measurement reliability. The effective measuring point, which the sound level difference with average sound pressure level is within 2 dB, could yield most reliable average sound pressure level. Therefore it is necessary to find the effective measuring points in the receiving room. Flanking transmission path should be sealed using sound absorber or magnet etc. to prevent from lowering the sound insulation performance.

• 한국건설관리학회:학술대회논문집
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• 한국건설관리학회 2004년도 제5회 정기학술발표대회 논문집
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• pp.494-499
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• 2004

국내 건설사업의 경쟁력은 국내적으로 수주감소 등으로 인하여 치열한 경쟁상황을 맞고 있으며, 국외적으로 건설선진국 뿐만 아니라 경쟁국가에도 경쟁력이 취약한 상태이다. 이를 극복하고 건설 경쟁력을 확보할 수 있는 방안이 제시되어야 한다. 따라서 본 연구에서는 건설사업 단계별로 내재된 낭비요소를 제거하여, 비용절감효과를 극대화 할 수 있는 성과측정 방안을 실 사례를 통해 제시하여 향후 유사 건설사업의 성과측정을 위한 방향을 제시하였다.

• Journal of Biosystems Engineering
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• 제30권2호
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• pp.127-133
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• 2005

Precision tillage is designed to till lands variably according to their firmness. Therefore, it is necessary to measure soil firmness in fields and present it in a form with which the variable tillage on be performed. Such forms may be classified into two categories: sensor-based and map-based forms. The map-based approach appears to be inevitable until the technology develops high enough to secure the sensor-based approaches. The first step for map-based precision tillage may be to develop a tillage recommendation map. In this study, a tractor-mountable automatic soil firmness measurement system was developed to construct a cone index map. The system is comprised of three ASAE Standard cone penetrometers and a hydraulic unit for controlling operation of the penetrometers. The system is designed to conduct stop-and-go measurements in fields. The measurements from the three penetrometers are transferred to a microcomputer and the average cone index was calculated. This average cone index was taken as soil firmness of the location where the measurement was made. The cone indices thus determined were used to construct a cone index map using the ArcView software. The system also displays the soil penetration resistance, cone index and soil depth as the cone penetrates into the soil. The field performance of the system was evaluated and the cone index maps at different depths were also presented.

• 한국도서관정보학회지
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• 제41권1호
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• pp.121-147
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• 2010

이 연구의 목적은 우리나라 디지털도서관의 서비스 품질을 객관적으로 측정할 수 있는 표준화된 서비스 품질 측정모형과 지표를 개발하고 검증하는 것이다. 디지털도서관의 서비스 품질 측정모형과 지표를 개발하기위해 문헌연구와 델파이 조사를 실시하였으며 연구모형을 검증하기 위해 디지털도서관 이용자 설문조사를 실시 하였다. 연구결과 4개의 차원, 7개의 구성요인, 30개의 측정항목으로 이루어지는 DL-SQI 모형이 개발되었으며 신뢰성 분석과 확인적 요인분석을 통해 연구모형의 타당도를 검증하였다.

• 동력기계공학회지
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• 제11권3호
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• pp.66-72
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• 2007

This study proposed new method to decide the reference model necessary for design PID controller. In generally, control design problems using the reference model have the following two factors. One factor is that numerical model of the controlled system can be obtained extremely, and the other is that specification for the closed-loop dynamic performance is pure moderate. Therefore, the control design procedure is essentially based on the partial reference model matching which offers a reasonable method to simplify the design and the controller configuration under the controlled system uncertainty. ITAE(Integral of time-multiplied absolute error) performance index and Kitamori method etc. which were used a reference model method had a limit to settling time and rising time of reference model that it arrived to steady state response according to the controlled system. On this study, if it only knew peak time of overshoot and settling time by measurement signal of the controlled system, it can be made the reference model easily. We proposed new method to improve performance index of the reference model superior to existing reference model index and illustrate the numerical simulation results to show the effectiveness of proposed control method design.

• 대한인간공학회지
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• 제27권1호
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• pp.21-27
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• 2008

An increased use of teams of actors within complex systems has led to the emergence of various approaches for the assessment of different features associated with team performance. Over the last two decades, the performance of teams in complex systems has received considerable attention from the human factors community, and a number of methods have been developed in order to assess and evaluate team performance. The purpose of this paper is to propose a methodology for measuring team efficiency of operators in the advanced main control room of Korean nuclear power plant. Team efficiency is an index which is estimated of gabs between individual performances and team performance. The index was developed to compare among teams through past all performance measurements.