• Nuclear Engineering and Technology
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• 제12권2호
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• pp.121-126
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• 1980

효과적인 저농도 인슈린 방사면역 측정법 확립 및 표지인슈린의 면역학적 환성과 탄소분말에 대한 흡착력의 상관관계를 밝히기 위하여 이들 두 다른 기준에 기초를 둔 두가지의 최적표지 인슈린선정방법을 비교한결과 탄소분말흡착에 의한 방법은 부적당함을 알 수 있었다. 일반적으로 표지인슈린의 방사능, 항체결합능, 탄소분말흡착능등은 서로 일치하지 않았다. 따라서 측정신뢰도를 높이기 위해서는 매 표지때마다 항체결합능으로 최적표지 인슈린을 선정해야 하며 탄소분말 흡착력으로 선정하면 안된다고 본다. 항체결합능에 따라 선정된 표지 인슈린을 써서 대조혈청중의 인슈린량이 정화히 측정되었으며 정온유지시간을 96시간으로 연장함으로써 5 $\mu$U/ml 하의 표준 인슈린투여 량에 대해서도 매우 예리한 응답곡선을 얻을 수 있었다.

• 한국해양공학회지
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• 제25권1호
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• pp.27-31
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• 2011

The previously developed method of estimating the propulsion performance of a UUV was applied to the high speed UUV, which is propelled by commercial thrusters. The thrusters were selected with an overdesign mentality; in other words, their capacities were excessive. At that point, the designer's concern was focused on a question regarding at what rpm the UUV could reach the design speed. Because the developed method required thrust coefficient curve data, the researchers asked for the POW data of the thrusters from the manufacturer. From the data, the researchers extracted the thrust coefficient and estimated the rpm value of design speed for the UUV. Finally, the researchers compared the estimated value and the result from a self-propulsion test using a VPMM (Vertical planar motion mechanism) test at a towing tank in MOERI.

• 조명전기설비학회논문지
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• 제25권9호
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• pp.50-55
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• 2011

This research is to apply the adaptive control of neuron networks for the real-time attitude control of Multi-articulated robot. Multi-articulated robot is expressed with a complicated mathematical model on account of the mechanic, electric non-linearity which each articulation of mechanism has, and includes an unstable factor in time of attitude control. If such a complex expression is included in control operation, it leads to the disadvantage that operation time is lengthened. Thus, if the rapid change of the load or the disturbance is given, it is difficult to fulfill the control of desired performance. In this research we used the response property curve of the robot instead of the activation function of neural network algorithms, so the adaptive control system of neural networks constructed without the information of modeling can perform a real-time control. The proposed adaptive control algorithm generated control signs corresponding to the non-linearity of Multi-articulated robot, which could generate desired motion in real time.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2003년도 춘계학술대회 논문집 전기기기 및 에너지변환시스템부문
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• pp.179-181
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• 2003

Conventional P/PI speed controller of today's servo drives should be manually tuned the controller switching set-point by trial-and-errors, which may translate the drive system down-time and loss of productivity. The adjustable drive performance is heavily dependent on the qualify of the expert knowledge and becomes inadequate in applications where the operating conditions change in a wide range, i.e., tracking command, cceleration/deceleration time, and load disturbances. In this paper, the demands on simple controls/setup are discussed for industry servo drives. Analyzing the frequency content of motor torque command, P/PI control mode switching is automatically peformed with some prior knowledge of the mechanical dynamics. The dynamic performance of the proposed scheme assures a desired tracking response curve with minimal oscillation and settling time over the whole operating conditions. For comprehensive comparison of traditional P/PI control scheme, extensive test is carried out on actual servo system.

• 동력기계공학회지
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• 제17권6호
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• pp.40-46
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• 2013

This paper describes the suggestion of the special seat with the auxiliary plastic member for movie theater chair. In the previous paper, we have reported on the development of foaming sponge seat with the auxiliary spring member. And we have confirmed that it was more effective on vibration transfer than the chair seat of foaming sponge only. In this study, we have examined the major design parameters needed in the development of a foaming sponge seat in which the mesh type plastic member are inserted to improve the vibration transfer effect of a chair seat. By applying experimentation to the prototype as well as the experimental modal analysis method, we made sure that the effect of the vibration transfer could be improved through the use of a mesh type plastic member as similar as the auxiliary spring member.

• 한국발생생물학회지:발생과생식
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• 제12권1호
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• pp.9-18
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• 2008

현존하는 생물들은 주변 환경에서 오는 반복되는 신호의 영향을 받고 있다. 그 신호는 태양 및 지구의 운동 관계에서 되풀이되어 일어나는 주기적인 변화이다. 생식 및 번식, 세포 내 각종 분자들의 작용, 발생 단계에 일어나는 다양한 변화 등등의 생리학적/행동학적 활동들은 모두 일주기든 연주기든 주기성을 띠고 있다. 일주기 리듬을 통하여 생물들은 근본적으로 주변의 외부 시간에 그 생물 자체가 적응하게 하여, 일상적으로 반복되는 환경에서 적절한 시기에 활동하도록 하는 것이다. 각종 리드미컬한 패턴 중에 편승 변환을 고찰하기 위해 제시된 한계주기궤도에 초점을 맞추어 고찰하고자 한다.

• 센서학회지
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• 제7권5호
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• pp.342-349
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• 1998

방사선 선량판독과 함께 열형광 현상의 연구가 가능한 다목적 TLD 판독장치를 제작하고 그 특성을 조사하였다. TLD에서 방출되는 열형광은 광전증배관과 전류-주파수 변환장치로 측정하였으며, 백금 열판을 사용하여 TLD를 가열하고 가온율을 선형적으로 변화시켰다. 개인용 컴퓨터와 interface board를 이용하여 전 장치를 제어하고 glow 곡선을 측정하였으며, 제어 소프트웨어로 자동이득조절이 가능하게 하였다. 제작한 TLD 판독장치는 선형적인 선량판독이 가능하였고 검출하한은 약 $10\;{\mu}Gy$였다.

• Industrial Engineering and Management Systems
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• 제4권2호
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• pp.176-183
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• 2005

The theory of signal detection has been applied to a wide range of practical situation for a long time, including sonar detection, air traffic control and so on. In general, in this theory, sensitivity parametric index d' and bias parametric index $\beta$ are used to evaluated the performance of vigilance. These indices use observer's response "hit" and "false alarm" to explain and evaluate vigilance, but not considering reaction time. However, the reaction time of detecting should be considered in measuring vigilance in some supervisory tasks such as unlimited monitoring tasks (e.g., supervisors in nuclear plant). There are some researchers have used the segments of reaction time to generate a pair of probabilities of hit and false alarm probabilities and plot the receiver operating characteristic curve. The purpose of this study was to develop a quantitative vigilance-measuring model by fuzzy sets, which combined the concepts of hit, false alarm and reaction time. The model extends two-values logic to multi-values logic by membership functions of fuzzy sets. A simulated experiment of monitoring task in nuclear plant was carried out. Results indicated that the new vigilance-measuring model is more efficient than traditional indices; the characteristics of vigilance would be realized more clearly in unlimited monitoring task.

• Structural Engineering and Mechanics
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• 제64권1호
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• pp.121-133
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• 2017

This paper proposes an analytical solution method for free vibration of curved functionally graded (FG) nonlocal beam supposed to different thermal loadings, by considering porosity distribution via nonlocal elasticity theory for the first time. Material properties of curved FG beam are assumed to be temperature-dependent. Thermo-mechanical properties of porous FG curved beam are supposed to vary through the thickness direction of beam and are assumed to be temperature-dependent. Since variation of pores along the thickness direction influences the mechanical and physical properties, porosity play a key role in the mechanical response of curved FG structures. The rule of power-law is modified to consider influence of porosity according to even distribution. The governing equations of curved FG porous nanobeam under temperature field are derived via the energy method based on Timoshenko beam theory. An analytical Navier solution procedure is used to achieve the natural frequencies of porous FG curved nanobeam supposed to thermal loadings with simply supported boundary condition. The results for simpler states are confirmed with known data in the literature. The effects of various parameters such as nonlocality, porosity volume fractions, type of temperature rising, gradient index, opening angle and aspect ratio of curved FG porous nanobeam on the natural frequency are successfully discussed. It is concluded that these parameters play key roles on the dynamic behavior of porous FG curved nanobeam. Presented numerical results can serve as benchmarks for future analyses of curve FG nanobeam with porosity phases.

• Geomechanics and Engineering
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• 제22권1호
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• pp.11-23
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• 2020

In this study, a new analytical-numerical procedure is developed to give the stresses and strains around a circular tunnel in rock masses exhibiting different stress-strain behavior. The calculation starts from the tunnel wall and continues toward the unknown elastic-plastic boundary by a finite difference method in the annular discretized plastic zone. From the known stresses in the tunnel boundary, the strains are calculated using the elastic-plastic stiffness matrix in which three dimensional Hoek-Brown failure criterion (Jiang and Zhao 2015) and Mohr-Coulomb potential function with proper dilation angle (i.e., non-associated flow rule) are employed in terms of stress invariants. The illustrative examples give ground response curve and show correctness of the proposed approach. Finally, from the results of a great number of analyses, a simple relationship is presented to find out the closure of circular tunnel in terms of rock mass strength and tunnel depth. It can be valuable for the preliminary decision of tunnel support and for prediction of tunnel problems.