• 한국유체기계학회 논문집
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• 제6권3호
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• pp.44-50
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• 2003

An experiment is conducted for measuring the performance of an air tool, which is operated at 100,000 RPM in an unloaded state with very low torque. A 551 kPa in gauge pressure is supply to the inlet of an air tool. An experimental apparatus is developed as a friction type dynamometer. Inlet total pressure, air flow rate, rotational speed and operating force are measured simultaneously. Torque, output power and specific output power are obtained with different rotational speeds. Those are compared with the experimental results which were obtained by a commercial dynamometer. However, no commercial dynamometers are available for measuring the torque above 30,000 RPM. In order to reduce the rotational speed, a reduction gear is applied between the air tool and the commercial dynamometer. Torque and power obtained by the commercial dynamometer show $55\%$ lower than those obtained by the developed friction type dynamometer, because the mass is added to the rotor of air tool for the braking system of the commercial dynamometer and power loss is generated by the reduction gear. From the compared results, the friction type dynamometer should be applied for measuring the performance of the air tool operating at low torque and high RPM.

• 한국철도학회논문집
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• 제14권6호
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• pp.484-488
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• 2011

해외 철도 선진국들은 고속열차의 독자적인 설계능력, 시험평가체계와 평가기술을 보유하고 있다. 국내에서도 열차의 성능을 평가하기 위한 선진화된 계측기술 및 시스템 개발이 필요하다. 본 연구는 400km/h급 동력분산식 차세대고속열차 개발의 중요한 요소인 차량시스템 및 부품의 성능과 안전성 및 신뢰성 검증을 종합적이고 효율적으로 평가하기 위한 종합계측시스템 개발에 대한 연구이다. 종합계측시스템은 차량계측장치, 팬터계측장치 및 영상장치 등으로 구성되며, 계측시험에 대한 총괄 모니터링을 위해 종합계측실을 구성하였다. 본 연구는 향후 열차의 성능평가기술 향상에 이바지 할 것으로 판단된다.

• 한국정밀공학회지
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• 제26권4호
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• pp.91-99
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• 2009

Because of both precise measurement and efficient quality control, coordinate measuring machines(CMMs) have been widely used in the industry. The purpose of this paper is to present a method to estimate the CMM measurement uncertainty using design of experiments. A factorial design is applied to carry out the performance test proposed by ISO 10360 and to investigate CMM measurement errors associated to orientation and length of the length bar. In order to assess the measurement uncertainty for the performance test, an analysis of the uncertainty components that make up the uncertainty budget has been carried out. The procedure for evaluating the uncertainty of it follows GUM ("Guide to the expression of uncertainty in measurement"). The results show that the proposed method is suitable to investigate CMM performance and determine the contribution of machine variables to measurement uncertainty.

• 한국과학교육학회지
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• 제17권2호
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• pp.127-137
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• 1997

The purpose of this study was to assess elementary student's ability of measuring length, area, and volume and reading metric scales. The findings of this study were as follows. All students were successful in measuring without scale, regardless of grades. But they were less successful in measuring the task using standard and nonstandard scales. Especially, in measuring area, lower grade students were not able to perform the task using nonstandard instruments, but higher grade students were able to perform the task. Measuring area using grade paper was least successful for sixth graders. In measuring volume, students under fifth grade read the upper scale when using graduated cylinder. In measuring by direct comparison, students were more successful in measuring length than in measuring area and volume using given material. The use of given nonstandard material was successful for 4th, 5th, and 6th grade students. In measuring using metric scale, lower grade students did not pay attention to the zero of the scale, but just read the end point. Higher grade students considered both zero and end points.

• 국제학술발표논문집
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• The 3th International Conference on Construction Engineering and Project Management
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• pp.738-746
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• 2009

The purpose of this study is to develop the web-based system for work performance analysis(WPAS). The need of work performance analysis system has already been suggested in many previous researches on the computerization of the performance measurement in the construction site by using the indicators such as time, cost and quality. However, they had focused on measuring or analyzing the result when the project would be over. The WPAS suggests three indicators - work reliability, work effectiveness and work efficiency - to manage the performance of the construction site. It can help the manager more easily recognize the status of on-going work in the construction site by measuring and analyzing the work reliability rate, the work effectiveness and work efficiency every day. This research includes the procedures for WPAS measurement process, database structure of WPAS which was analyzed by the IDEF0 and the data flow diagram. Finally, this research introduces the result of WAPS's case studies and validation in the Korean construction site.

• 한국정보통신학회논문지
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• 제22권6호
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• pp.888-894
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• 2018

본 논문에서는 연선의 성능 측정을 위한 혼합 모드 산란계수 측정시스템을 제안하였다. 연선은 균형 형태의 소자로써 일반적으로 동축 형태로 구현된 네트워크 분석기를 이용하여 특성 측정이 불가능하다. 이때, 발룬을 이용하여 균형 신호와 불균형 신호 간 변환을 통해 측정이 가능하지만 측정 주파수 대역폭이 제한되는 문제가 있다. 제안하는 시스템은 발룬을 사용하지 않고 4포트 벡터 네트워크 분석기와 설계한 고정구를 이용하여 혼합모드 산란계수를 측정하여 연선의 성능을 측정한다. 제안하는 시스템을 이용하여 상용 이더넷 케이블의 성능을 측정해보고 발룬의 이용한 결과와 비교해 보았다. 이를 통해 제안하는 시스템을 이용해 연선의 성능 측정이 가능함을 확인하였다.

• 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.

• International Journal of Quality Innovation
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• 제3권2호
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• pp.57-73
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• 2002

Recent interests in total quality management (TQM) and business excellence (BE) had been fuelled with a range of national and regional awards. These awards are being increasingly used by organisations as part of the business improvement process and strategic benchmarking. This paper reviews the concepts and approaches of performance measurement (PM) and discusses the integration of PM with the TQM and BE philosophies. A TQM-BE-PM framework with a set of self-assessment checklists was developed. In order to complement the literature base with empirical evidence, an industry survey was conducted and a trial implementation of the framework was carried out in a leading manufacturing firm in Hong Kong. The self-assessment performance data of the fm was evaluated and then benchmarked with the industry averages obtained from the survey. This paper presents the empirical findings and discusses the applicability of the framework in measuring and benchmarking organisational performance toward continual improvement.

• 한국과학교육학회지
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• 제20권1호
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• pp.1-11
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• 2000

본 연구에서는 초 중등 학생들의 눈금 읽기 능력과 측정도구의 용도 및 단위에 대한 개념을 조사했다. 초등학생 72명, 중1 학생 69명, 중3 학생 80명의 학생을 대상으로 수행 평가 및 지필 평가를 실시했다. 눈금읽기 능력을 평가하기 위해서 개별 수행 평가를 실시했는데, 학생 개개인은 서류 봉투의 가로 세로 길이, 물의 온도, 물의 부피 등을 실험실에서 주로 사용하는 주어진 측정 도구를 사용하여 측정했다. 측정 도구 및 단위와 관련된 개념을 평가하기 위해서는 그림과 사진이 그려진 질문지를 사용했다. 눈금 읽기 능력 면에서 각 학년마다 적지 않은 측정오차를 내는 학생이 있음이 드러났으며 특히 질량이나 부피 측정의 경우 그 수가 더욱 증가했다. 측정 도구에 대한 학생의 개념 조사 결과 학생들은 물리량 개념이 정확하지가 않아 측정 도구가 측정할 수 있는 물리량을 제대로 지적하지 못했다. 또한 단위에 대해서도 혼동이 있어서 특히 질량, 무게, 부피나 힘의 단위 등을 어려워하고 있음을 알 수 있었다.

• Journal of Construction Engineering and Project Management
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• 제5권1호
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• pp.1-10
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• 2015

In construction, stakeholders of extended project team play a key role in the overall project performance. Successful integration of stakeholders demands for good management practices at strategic, operational and project levels. Targets and measures to improve the stakeholder performance encourage the creativity and willingness of stakeholders of extended project team to develop the better ways to achieve the project objectives. This paper presents a generic descriptive method, showing how stakeholder's ability and influence impacts on project performance in the construction sector. The findings of a series of interviews with key informants are presented and the following main conclusion is drawn: improving project performance through stakeholder's contribution and measuring their performance can strengthen the project performance. This innovative approach which redefines the process of improving the project performance in construction projects will be of interest to those who intend to manage the projects in practice as well as to those who interested in advancing theory.