• 한국정보과학회:학술대회논문집
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• 한국정보과학회 2003년도 봄 학술발표논문집 Vol.30 No.1 (B)
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• pp.49-51
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• 2003

성공적인 소프트웨어 개발을 위해서는 프로젝트 계획 수립단계에서 정확한 예측 모델을 연구하는 것이 중요하다. 소프트웨어 개발의 중요성이 대두됨에 따라 현재에는 많은 기존의 프로젝트 데이터를 보관하게 되었다. 기존의 예측모델에서는 개발환경에 따라 서로 다른 형태의 모델을 만들어 개발비용을 예측하였다. 모델의 형태에 따른 신뢰도 또한 주요 이슈로 작용하였다. 이 논문에서는 이러한 많은 프로젝트 데이터와 현재 개발하고자 하는 프로젝트에 대하여 과거의 데이터 중 가장 유사한 최적의 프로젝트를 찾아내기 위해 FP(Function Point)를 이용하는 많은 프로젝트 데이터에 유전자 알고리즘을 적용하여 최적의 유사 모델을 찾아내는 방법에 대하여 제안하고자 한다.

• 공업화학
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• 제20권1호
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• pp.9-14
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• 2009

양쪽성 계면활성제는 등전점 이하의 pH 조건에서 양이온 계면활성제로 작용함으로써 유연력을 나타낼 수 있으며, 등전점 이상의 pH 조건에서는 음이온 혹은 비이온 계면활성제로 작용하여 세정력을 나타낼 수 있다. 따라서 pH에 따른 양쪽성 계면활성제의 특성을 활용하면 한 종류의 계면활성제 분자로 세정력과 유연력을 동시에 발휘할 수 있다. 본 연구에서는 amine oxide 양쪽성 계면활성제에 대하여 계면활성제의 기본적인 물성(임계 마이셀 농도, 표면장력, 계면장력, 접촉각, 점도, 계면활성제 시스템의 상거동 등)을 측정하였으며, 또한 계면활성제 수용액에 대하여 zeta potential 측정과 QCM 실험을 통하여 양쪽성 계면활성제가 양이온 계면활성제에서 음이온 혹은 비이온 계면활성제로 작용이 전환되는 등전점을 결정하였다. 본 실험에서 사용한 amine oxide 양쪽성 계면활성제의 등전점은 7.35와 7.4인 것을 각각 zeta potential 측정과 QCM 실험을 통하여 확인할 수 있었으며, 이 결과는 문헌에 보고된 값과 유사한 결과를 나타냄을 알 수 있었다.

• 대한기계학회논문집B
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• 제33권7호
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• pp.477-485
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• 2009

The study of nitrogen dilution effect on the flame stability was experimentally investigated in a non-premixed turbulent lifted hydrogen jet with coaxial air. Hydrogen gas was used as a fuel and coaxial air was used to make flame liftoff. Each of hydrogen and air were injected through axisymetric inner and outer nozzles ($d_F=3.65\;mm$ and $d_A=14.1\;mm$). And both fuel jet and coaxial air velocity were fixed as $u_F=200\;m/s$ and $u_A=16\;m/s$, while the mole fraction of nitrogen diluents gas was varied from 0.0 to 0.2 with 0.1 step. For the analysis of flame structure and the flame stabilization mechanism, the simultaneous measurement of PIV/OH PLIF laser diagnostics had been performed. The stabilization point was selected in the most upstream region of the flame base and defined as the point where the turbulent flame propagation velocity was equal to the axial component of local flow velocity. We found that the turbulent flame propagation velocity increased with the decrease of nitrogen mole fraction. We concluded that the turbulent flame propagation velocity was expressed as a function of turbulent intensity and axial strain rate, even though nitrogen diluents mole fraction was changed.

• 한국정보통신학회논문지
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• 제8권1호
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• pp.185-191
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• 2004

본 논문은 컴퓨터 그래픽에서 주요 이슈중 하나인 의류 착장시스템 구현을 위하여 직물의 가장 큰 특성중의 하나인 드레이프성 측정에 관한 연구이다. 가장 최적의 직물의 드레이프성을 구하기 위해 거리함수를 이용하여 볼록점을 계산한 후 직물의 둘레 및 면적, 볼록점 사이의 최대 최소 점과 평균거리와 같은 정보를 구하였다. 그리고 직물의 드레이프성을 나타내는 척도로 직물의 둘레와 면적을 기준으로 원형도를 구하였다. 실험결과 원형도가 직물의 드레이프성을 나타내는 여러 특성치 중 가장 좋은 결과를 보였다. 측정된 직물의 드레이프성은 의류 착장시스템 개발에 기여할 것이다.

• 한국군사과학기술학회지
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• 제21권3호
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• pp.323-330
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• 2018

In this paper, design and fabrication of a MSP(Multiple Scattering Points) discriminator for a simulated target measurement using a HRR(High Range Resolution) RADAR are described. The MSP discriminator is designed to provide a reference signal at the installed point on the simulated target in an outdoor test. The MSP discriminator is designed to have a remote control function that can turn the MSP discriminator on and off when the target moves to a remote location. While the MSP discriminator is off, the MSP discriminator is designed to be small enough not to spoil the target's unique RCS. The MSP discriminator consists of RF components in the Ku-band. In order to prevent spreading of the signal, a cable were added to the MSP discriminator to have an appropriate feedback loop delay considering the resolution of the RADAR. The fabricated MSP discriminator provided a reference scattering point as an RCS of approximately 1 dBsm. As a result, by using the MSP discriminator, the physical scattering points of the target were clearly identified in the measured signals with the RADAR.

• 대한전기학회논문지:전기물성ㆍ응용부문C
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• 제52권10호
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• pp.476-480
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• 2003

In this paper, we have performed 3-dimensional time-resolving measurement of the Ne light emitted from the cell of plasma display panel(PDP) as a function of the pressure using the scanned point detecting system. From the temporal behavior results, we could analyze the discharge behavior of panel with Ne-Xe(4%) mixing gas and 300 torr, 400 torr and 500 torr pressure. At the top view of panel, the discharge of 300 torr panel starts at the 634 ns and ends at the 722 ns. The emission duration time is about 90 ns. The discharge of 400 torr panel starts at the 682 ns and ends at the 786 ns. the emission duration time is about 100 ns. Also, the discharge of 500 torr panel starts at the 770 ns and ends at the 826 ns. the emission duration time is about 56 ns. The discharge moves from inner edge of cathode electrode to outer cathode electrode forming arc type. In the side view of 300 torr, 400 torr and 500 torr an emission shows that the light is detected up to 180${\mu}{\textrm}{m}$, 150${\mu}{\textrm}{m}$ and 70${\mu}{\textrm}{m}$ height of barrier rib and the emission distribution of the 300 torr is wider than 400 torr, 500 torr.

• 대한원격탐사학회:학술대회논문집
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• 대한원격탐사학회 2007년도 Proceedings of ISRS 2007
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• pp.540-543
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• 2007

The modulation transfer function (MTF) in a camera system is a measurement of how well the system will faithfully reproduce the original scene. The electro-optical camera system consists of optics, an array of pixels, and an electronics which is related to the image signal chain. The system MTF can be cascaded with each element's MTF in the frequency domain. That is to say, the electronics MTF including the detector MTF can be recalculated easily by the acquired system MTF if the well-known test optics is used in the measuring process. A Time-Delay and Integration (TDI) detector can make a signal increase by taking multiple exposures of the same object and adding them. It can be considered the various methods to measure the MTF of the TDI camera system. This paper shows the actual and practical MTF measuring methods for the detector and electronics in the TDI camera. The several methods are described according to the scan direction as well as the TDI stages such as the single line mode and the multiple-lines mode. The measuring is performed in the in the static condition or dynamic condition to get the point spread function (PSF) or the line spread function (LSF). Especially, the dynamic test bench is used to simulate on track velocity to synchronize with TDI read out frequency for the dynamic movement.

• 한국기계가공학회지
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• 제18권5호
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• pp.1-8
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• 2019

Breath analysis using a portable device is better than the classical breath analysis system in terms of installation and operation. There is an increasing need to develop cost-effective equipment for testing gas sensors from the viewpoint of functionalities that can be applied applicable to portable devices. In the present study, an economical gas chamber for in-situ gas measurement is implemented with a single gas chamber without using expensive gas storage and control equipment; the gas response characteristics are analyzed using the above-described chamber. The main features of the implemented gas chamber are simple injection procedure, improved gas diffusion, easy measurement and cleaning, support for low-power mode measurement function for portable devices, and open source platform. Moreover, an analysis of gas response characteristics based on changes in sensor voltage show that the sensitivity and 90% response time are affected by the sensor voltage. Furthermore, the sensitivity graph has an inflection point in a specific range. The gas sensor applied in this study showed fast response speed and high sensitivity for sensor voltages of 3.0-3.5 V, regardless of the concentration of acetone gas, the target gas used in this study.

• 대한물리치료과학회지
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• 제23권1호
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• pp.1-8
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• 2016

Purpose : The purpose of this study was to investigate the response of pulmonary function and heart rate recovery of smoker and nonsmoker in males aged 20s after graded maximal exercise. Method : The subjects were composed of smoker group (n=12) and nonsmoker group (n=12) in males aged 20s. Each groups completed an graded maximal exercise with Bruce protocol and were assessed on the pulmonary function(forced vital capacity : FVC, forced expiratory volume-one second : FEV1, FEV1/FVC) and heart rate. Result : The results were as follows: First, heart rate in the measurement point was a statistically significant difference for smoker and non-smoker group after maximal exercise, but FVC, FEV1, FEV1/FVC was no difference. Second, FEV1/FVC between smoker and nonsmoker group was a statistically significant difference after maximal exercise, but FVC, FEV1, heart rate was no difference. Conclusion : The results of this study is that smoking is negative effects on FEV1/FVC of pulmonary function in males aged 20s after maximal exercise.

• Smart Structures and Systems
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• 제24권2호
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• pp.233-242
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• 2019

In this paper, an inverse approach based on uniform load surface (ULS) is presented for structural damage localization and quantification. The ULS is excellent approximation for deformed configuration of a structure under distributed unit force applied on all degrees of freedom. The ULS make use of natural frequencies and mode shapes of structure and in mathematical point of view is a weighted average of mode shapes. An objective function presented to damage detection is discrepancy between the ULS of monitored structure and numerical model of structure. Solving this objective function to find minimum value yields damage's parameters detection. The teaching-learning based optimization algorithm has been employed to solve inverse problem. The efficiency of present damage detection method is demonstrated through three numerical examples. By comparison between proposed objective function and another objective function which make use of natural frequencies and mode shapes, it is revealed present objective function have faster convergence and is more sensitive to damage. The method has good robustness against measurement noise and could detect damage by using the first few mode shapes. The results indicate that the proposed method is reliable technique to damage detection in structures.