• 한국태양에너지학회 논문집
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• 제27권4호
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• pp.137-146
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• 2007

This study is about the passive cooling effects of three outdoor solar shading facilities as trees, pergola with wistaria vine and membrane shading structure, which are expected to provide cool spots in the summer. Field observations of measuring thermal environment of selected facilities is executed. Thermal environment measuring was categorized as short wave radiation, long wave radiation, net radiation, globe temperature, surface temperature measured by infrared camera. Heat transfer mechanism is analyzed with overall data from field measurement. Results from this study are as below; 1) Radiation balance measured on shaded surface under membrane shading structure was 17%($86W/m^2$) of the unshaded surface radiation balance($511W/m^2$). 2) Surface temperature comparison between vegetation and membrane of the shading structure is performed at 3 o'clock in the afternoon. Surface temperature of vegetation was same as air temperature and that of membrane was $5^{\circ}C$ higher than air temperature. Vegetation transpiration is considered as the causing factor which make those differences. 3) Results from this study could be used as fundamental data for reducing heat island phenomena and continuos research on this subject would be needed.

• 한국공간구조학회논문집
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• 제16권2호
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• pp.39-45
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• 2016

Membrane structure is a system that is stabilized by maintaining a tensile state of the membrane material that originally cannot resist the bending or pressure. Also, it is a system that allows the whole membrane structure to bear external loads caused by wind or precipitation such as snow, rain and etc. Tension relaxation phenomenon can transpire to the tension that is introduced to the fabric over time, due to the innate characteristics of the membrane material. Thus, it is important to accurately understand the size of the membrane tension after the completion of the structures, for maintenance and management purposes. The authors have proposed the principle of theoretically and indirectly measuring the tension by vibrating the membrane surface with sound waves exposures against the surface, which is compartmentalized by a rectangular boundary, and by measuring the natural frequency of the membrane surface that selectively resonates. The authors of this paper measured the tension of preexisting membrane structure for its maintenance by using the developed portable measurement equipment. Through analyzing the measurement data, the authors review the points that should be improved and the technical method for the new maintenance system of membrane tension.

• 한국콘텐츠학회:학술대회논문집
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• 한국콘텐츠학회 2015년도 춘계 종합학술대회 논문집
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• pp.15-16
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• 2015

Measuring sensor, equipment, ICT facilities and their software have relatively short life time comparing to constructional structure so that we should exchange or fix them continuously in the process of maintenance and management. In this paper, we propose a novel design of integrated maintenance, management, and measuring monitoring system applying the concept of mobile cloud. For the sake of disaster prevention for constructional structures such as bridge, tunnel, and other traditional buildings in the village of local heritage, we analyze status of these structures in the long term or short term period as well as disaster situations. Collecting data based on mobile cloud and analyzing future expectations based on probabilistic and statistical techniques, we implement our integrated monitoring system for constructional structures to solve these existing problems. Final results of this design and implementation are basically applied to the monitoring system for more than 10,000 structures spread over national land in Korea. In addition, we can specifically apply the monitoring system presented here to a bridge of timber structure in Asan Oeam Village and a traditional house in Andong Hahoe Village to watch them from possible disasters. Total procedure of system design and implementation as well as development of the platform LinkSaaS and application services of monitoring functions implemented on the platform. We prove a good performance of our system by fulfilling TTA authentication test, web accommodation test, and operation test using real measuring data.

• 한국공간구조학회:학술대회논문집
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• 한국공간구조학회 2008년도 춘계 학술발표회 논문집
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• pp.171-178
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• 2008

This paper is concerned with the development of a measurement system using field measuring device which will give the membrane stress of the membrane structures. Up to this point, several techniques on measurement of membrane stresses has been proposed and some have been used in the fields, but accuracy of the measured stresses to be far from reliable one. Such situation has not been changed until recent days, we do not have the measurement device on which we can depend. On top of that, due to the different properties in cross directions for material of the membrane, the stress in the warp direction is different from that in the fill one. A new method is proposed to measured membrane stresses in two different direction separately, where instead of membrane stresses directly, an external force perpendicular to the membrane to be applied. A portable device can measure the applied force and the displacement. A special testing bed to be fabricated to accommodate $50cm{\times}50$ manbrane specimen which can apply 5 ton load in two orthogonal direction. A special device using push-pull gage was developed. To measure the membrane stresses in warp and fill direction separately, a different length of the tips are used. The measuring device which can called tension meter, can be calibrated on the testing bed, and optimized the length and shape of tip.

• 한국공간구조학회논문집
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• 제8권6호
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• pp.67-74
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• 2008

본 연구는 막구조물의 장력 측정을 위한 휴대용 막장력측정기기의 개발을 목적으로 한다. 2축시험기에 장착된 막의 장력을 간이 측정기에 의해 측정하여 구한 실험 데이터를 근거로 효율적인 2축방향 막 장력측정기기를 개발하는데 그 목적이 있다. 연구결과 개발된 휴대용 간이 장력측정기기는 정량적이고 정성적인 측면에서 데이터의 정밀도가 매우 높아 향후 상용제픔으로도 개발이 가능함을 알 수 있었다.

• 한국음향학회지
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• 제16권5호
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• pp.36-42
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• 1997

본 논문은 건축구조체 내에서 진동 에너지의 크기와 흐름을 측정하는 하나의 방법인 진동인텐시티측정법에 관한 내용이다. 진동인텐시티법의 기본적인 원리와 계측이론을 이론적 해석이 명쾌한 1차원 보를 대상으로 하여 이론 및 실험적으로 검토하였다. 또한 징동가속도레벨을 이용한 해석 결과와 비교함으로써 진동인텐시티의 계측가능성을 검토하였다. 그 결과, 근접장의 영향이 무시가능한 조건에서는 진동가속도 분포로부터 구한 계산값과 진동인텐시티법에 의한 측정값이 거의 일치하여, 이러한 류의 진동 계측에 진동인텐시티법이 응용될 가능성이 있음을 알수 있었다. 그러나 반사파의 성분이 많이 존재하는 음장, 특히 근접장에 있어서는 측정신호가능 위상차비가 적어 진동인텐시티를 계측하기 어렵다는 것을 알았다.

• 대한조선학회논문집
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• 제32권4호
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• pp.48-54
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• 1995

선박용 추진기의 단독시험을 위한 소형시험기를 설계제작하고 모형선 예인수조에서 검증시험을 실시하였다. 제작된 시험기는 전동기의 반동력을 스트레인 게이지를 이용하여 직접 계측함으로써 재래의 시험기에서 사용하고 있는 마모성 슬립링을(Slip Ring) 제거하였다. 또한 기기의 구조 부재를 검력계의 검출부로 사용함으로써 소형의 모형선에 탑재될 수 있도록 경량화 및 소형화를 이룩하였다. 개발된 이 제품은 회류수조 등에서 효과적으로 사용될 수 있을 뿐만 아니라 선형시험수조 및 캐비테이션 터널에서 사용될 각종 시험 기기 설계의 기초기술을 포괄하는 것으로 평가된다.

• Composites Research
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• 제16권6호
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• pp.56-61
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• 2003

In this Paper, a fiber Bragg grating(FBG) sensor system is described and FBGs are well-suited for long term and extremely severe experiments, where traditional strain gauges fail. In the system. a reflect wave-length measurement method which employs a tunable light source to find out the center wave-length of FBG sensor is used. We apply the FBG system to nuclear energy Power Plant for structural integrity test to measure the displacement of the structure under designed pressure and to check the elasticity of the structure by measuring the residual strain. The system works very well and it is expected that it can be used for a real-time strain, temperature and vibration detector of smart structure.

• 대한인간공학회지
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• 제12권2호
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• pp.85-91
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• 1993

Data obtained for sensory evaluation have a wide dispersion and fuzziness since human sensory organs are used as a means of measuring sensation instead of measuring instruments. Such dispersion and fuzziness are caused by all kinds of time error and have a great influence on the sensory evaluation, but most of previous papers not consider time errors. In this study, the comparative judgement capability of the evaluator was discriminated by means of the eigen- structure analysis on the premise that evaluation values of sensory evaluators obtained by a paired-comparison become different by the order of sample presentation.

• 한국연소학회:학술대회논문집
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• 한국연소학회 2014년도 제49회 KOSCO SYMPOSIUM 초록집
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• pp.315-316
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• 2014

Combustion gases emit various radiation signals by chemical reaction and excited molecules in combustion system. Since temperature measurement of combustion system is very difficult, non-contact temperature measuring methods are being researched. In this paper, we propose optical system of simple structure and implement technique for measuring temperature partially in furnace using radiation wavelength signals of high temperature $CO_2$ gas generated during combustion.