• Advances in aircraft and spacecraft science
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• 제2권3호
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• pp.303-328
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• 2015

A design methodology is presented to develop the hingeless control surfaces for MAV using adhesively bonded Macro Fiber Composite (MFC) actuators. These actuators have got the capability to deflect the trailing edge surfaces of the wing to attain the required maneuverability, besides achieving the set aerodynamic trim condition. A scheme involving design, analysis, fabrication and testing procedure has been adopted to realize the trailing edge morphing mechanism. The stiffness distribution of the composite MAV wing is tailored such that the induced deflection by piezoelectric actuation is approximately optimized. Through ground testing, the proposed concept has been demonstrated on a typical MAV structure. Electromechanical analysis is performed to evaluate the actuator performance and subsequently aeroelastic and 2D CFD analyses are carried out to see the functional requirements of wing trailing edge surfaces to behave as elevons. Efforts have been made to obtain the performance comparison of conventional control surfaces (elevons) with morphing wing trailing edge surfaces. A significant improvement in lift to drag ratio is noticed with morphed wing configuration in comparison to conventional wing. Further, it has been shown that the morphed wing trailing edge surfaces can be deployed as elevons for aerodynamic trim applications.

• 한국항행학회논문지
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• 제19권2호
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• pp.91-97
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• 2015

이 논문은 항공 분야에서의 안전필수 소프트웨어를 평가하기 위한 고려사항을 기술한다. 항공 분야에서의 안전필수 소프트웨어의 평가를 수행하기 위해서는 해당 소프트웨어의 평가 수준에 대한 정보가 필요하다. 그 수준은 표준에 명시되어 있으나 소프트웨어 자체적으로 결정되는 요소가 아니며 시스템 안전 평가 결과 및 시스템 설계 결과에 의존적이다. 그러므로 소프트웨어 평가수준을 결정하기 위해 시스템 개발 및 시스템 안전 평가 표준에서 필요로 하는 정보에 대해 설명한다. 그리고 소프트웨어를 평가하기 위한 기존의 방법론들을 조사하고 항공기 지상 유도 및 통제 시스템 소프트웨어의 평가에 적용할 방법을 제시한다.

• 비파괴검사학회지
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• 제6권2호
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• pp.7-16
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• 1987

Eddy Current Examination is expected as the effective technique for nondestructive inspection of steam generator and various kinds of heat exchanging tubes made of STS - 304. In Case of E. C. T, a study on the various factors which have an effect on coil impedance is very important to the sensitivity of defect detection and the ratio of signal to noise. Therefore, this study analyzed coil impedance by means of the variational principle, the minimized theory of energy functional and the application of Finite Element Method. Really by using E. C. T, the relationship between the size of defects and the intensity of Eddy Current Signals can be obtained. Signal intensity becomes maximum at certain frequency. This frequency is affected by the characteristics and the position of signal sources.

• ETRI Journal
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• 제22권1호
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• pp.1-11
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• 2000

The Satellite Operation System (SOS) has been developed for a low earth orbiting remote sensing satellite, Korea Multipurpose Satellite-I, to monitor and control the spacecraft as well as to perform the mission operation. SOS was designed to operate on UNIX in the HP workstations. In the design of SOS, flexibility, reliability, expandability and interoperability were the main objectives. In order to achieve these objectives, a CASE tool, a database management system, consultative committee for space data systems recommendation, and a real-time distributed processing middle-ware have been integrated into the system. A database driven structure was adopted as the baseline architecture for a generic machine-independent, mission specific database. Also a logical address based inter-process communication scheme was introduced for a distributed allocation of the network resources. Specifically, a hotstandby redundancy scheme was highlighted in the design seeking for higher system reliability and uninterrupted service required in a real-time fashion during the satellite passes. Through various tests, SOS had been verified its functional, performance, and inter-face requirements. Design, implementation, and testing of the SOS for KOMPSAT-I is presented in this paper.

• 대한수의학회지
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• 제44권2호
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• pp.317-322
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• 2004

This study was performed to evaluate echocardiographic parameters in dogs with experimental mitral regurgitation subjected to dobutamine stress testing. In 8 beagle dogs, a 4-prong grasping forceps was inserted into the left ventricle through the carotid artery with fluoroscopic guidance. The disruption of chordae or mitral valve leaflet was performed. Echocardiographic protocols included quantitative Doppler echocardiography and M-mode measurement for evaluating left ventricle function. After all measurement was obtained at rest, dobutamine was infused incrementally. In stress testing, all measurement also was performed at rest as the same method. In stress Doppler echocardiography, regurgitant fraction and aortic stroke volume was increased significantly (P<0.001). Effective regurgitant orifice and regurgitant volume was not changed. In M-mode examination, fractional shortening was increased significantly at stress test (P<0.001). From the results obtained in this study, it could be suggested that dobutamine stress echocardiography increase left ventricle performance in non-functional mitral regurgitation and quantitative Doppler echocardiography is non-invasive, accurate method in valvular regurgitation.

• Toxicological Research
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• 제32권1호
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• pp.5-8
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• 2016

Risk assessment is the process of quantifying the probability of a harmful effect to individuals or populations from human activities. Mechanistic approaches to risk assessment have been generally referred to as systems toxicology. Systems toxicology makes use of advanced analytical and computational tools to integrate classical toxicology and quantitative analysis of large networks of molecular and functional changes occurring across multiple levels of biological organization. Three presentations including two case studies involving both in vitro and in vivo approaches described the current state of systems toxicology and the potential for its future application in chemical risk assessment.

• 반도체디스플레이기술학회지
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• 제3권2호
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• pp.27-33
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• 2004

This paper is concerned with development of a micro tensile testing machine for optical functional materials such as single or poly crystal silicon and nickel film. Two micro tensile testers have been developed for various types of materials and dimensions. One of the testers is actuated by a PZT and the other is actuated by a servo motor for a precise displacement control. The specifications of PZT actuated micro tensile tester developed are as follows: the volumetric size of tester is desktop sized of 710$\times$200$\times$270 $mm^3$; the minimum load capacity and the load resolution in the load cell of 1N are 3 mN and 0.1 mN respectively; the full stroke and the stoke resolution of piezoelectric actuator are 1 mm and 10nm respectively. A special automatic specimen installing equipment is applied in order to prevent unexpected deformation and misalignment of specimens during handling of specimen for testing.

• 한국기계가공학회지
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• 제20권11호
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• pp.86-91
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• 2021

Recently, functional clothes that can reduce deposition and/or penetration of fine dust have been developed. However, there are no methods to quantitatively evaluate the performance of these clothes. In this study, we developed a method to contaminate a fabric using fine dust and established an approach to quantitatively assess the degree of particle contamination on the fabric surface. Silicate powder was chosen as the particle to simulate fine dust because silicate particles are fluorescent under UV light; therefore, they can be distinguished from any color of non-fluorescent fabric surface. A camera with a high-resolution lens system was used to scan the surface of the contaminated fabric surface, and the degree of particle contamination of the fabric surface was analyzed in terms of the pixels corresponding to the area of the fabric surface contaminated by silicate particles. Finished or unfinished nylon fabrics as well as cotton fabrics were contaminated with silicate particles, and their surfaces were scanned using the established camera. The proposed assessment method was found to be useful for quantitatively comparing the degree of particle contamination of the fabrics.

• 한국항행학회논문지
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• 제20권2호
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• pp.148-154
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• 2016

안전과 관련된 CNS/ATM 시스템의 개발은 안전 평가 활동을 필요로 한다. 안전 평가에는 기능 위험 평가를 포함하며, 이는 시스템의 위험한 상황을 감소시키기 위한 시스템 안전 요구사항을 도출하는데 영향을 끼친다. 본 논문은 A-SMGCS에 대한 기능 위험 평가에 대한 사례 연구를 수행하였다. 이를 위해 관련연구인 Eurocontrol과 EMMA에서 수행한 연구를 분석하였으며 Eurocontrol 및 EMMA의 기능 위험 평가 체계를 통합하였다. FHA(functional hazard assessment) 범위뿐만 아니라 FHA를 위한 여러 가정 사항들을 인천국제공항에 대해서 정의하였다. 29개의 위험원이 식별되었고, 각각에 대해 심각도가 평가되었다. 그리고 위험원에 대한 노출빈도와 안전 목적이 이벤트 트리 분석 방법을 사용하여 분석되었다. 본 연구 결과와 EMMA의 결과에 대한 차이를 분석하였으며 또한 본 연구에서의 평가 결과에 대해서도 검토 하였다.

• 대한기관식도과학회지
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• 제9권1호
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• pp.83-86
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• 2003

Background and Objectives : Paradoxical vocal cord movement is a series of paroxysmal adduction of the anterior two-thirds of the vocal cords during respiration or during phonation. The choking, stridor, and wheezing in this condition occur primarily on inhalation, rather than on exhalation. The two pathognomonic diagnostic criterias that need to be assessed during an acute presentation are laryngoscopy with direct visualization of paradoxical adduction of the vocal cords and pulmonary function testing. Materials and Methods : A retrospective review of 3 patients who were referred to otolaryngologist from pulmonology department, and were confirmed by typical laryngoscopic findings with paradoxical adduction of the vocal cords was conducted. Results The patients were misdiagnosed as exercised-induced asthma, and unresponsive to corticosteroid and bronchodilators. Improvement was achieved only by diagnosis with paradoxial vocal cord movement. Biofeed back therapy, voice therapy, treatment for reflux laryngitis improved symptoms. Conclusion The etiology of paradoxical vocal cord movement is unknown. It may be functional or emotional. The functional factors that were proposed are neurologic deficit and gastroesophageal reflux. Management methods of this condition consist of psychological counselling, voice therapy, and antireflux medication.