• 한국정밀공학회지
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• 제27권5호
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• pp.56-62
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• 2010

This paper presents the development process of roof carrier assembly using a one side release system for a vehicle. An RV(Recreational Vehicle) or SUV(Sports Utility Vehicle) has a roof carrier system on an upper surface of a roof panel for loading large or long size baggage. Such a roof carrier system is comprised of a roof rack longitudinally mounted on a roof panel and cross bar perpendicularly installed in the horizontal direction. Several locking mechanisms used in most vehicle roof carrier systems are composed with both side releasable locking ones. The obvious drawback to this arrangement is that when the user desires to reposition the cross bar, first one of the locking members must be unlocked and then the user must walk around to the opposite side of the vehicle to unlock the other member. In this paper, we proposed a newly locking mechanism, which allows a user simultaneously place both locking members of the roof carrier in locked and unlocked positions. In order to estimate design compatibility, structural and modal analysis is performed. Furthermore, a prototype based on the proposed design has been made, and then durability test carried out. From the simulation and experimental results, the proposed roof carrier system is proved effective and safe.

• 제어로봇시스템학회논문지
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• 제7권8호
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• pp.680-688
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• 2001

In this paper, the fuzzy control with variable input gain is applied to maintain the consistent tension in the process of taking up and releasing texture. In the process of discharging web on one side rolling it on another, the take-up drum gets smaller on the release drum side as it gets bigger on the rolling side, thus it is necessary to change the balance of velocity between the sides. In order to solve the problem a tension controller is necessary. The PI control method has been employed to maintain the consistent tension, but the PI control method produces a problem which requires an experienced worker with the traits of the machine, in order to perform the fine adjustments according to the environment of the process. For solving the above problem, we apply fuzzy control to the tension system, in order to produce a uniform roll. For the performance test, the fuzzy controller does not need to revise the parameters. Therefore the fuzzy controller exhibits an excellent additivity for the tension system where the system is changed with time.

• 대한기계학회:학술대회논문집
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• 대한기계학회 2008년도 추계학술대회B
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• pp.2946-2951
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• 2008

Combustion instability is a major issue in design of gas turbine combustors for efficient operation with low emissions. Combustion instability is induced by the interaction of the unsteady heat release of the combustion process and the change in the acoustic pressure in the combustion chamber. In an effort to develop a technique to predict self-excited combustion instability of gas turbine combustors, a new stability analysis method based on the transfer matrix method is developed. The method views the combustion system as a one-dimensional acoustic system with a side branch and describes the heat source as the input to the system. This approach makes it possible to use the advantages of not only the transfer matrix method but also well-established classic control theories. The approach is applied to a simple gas turbine combustion system to demonstrate the validity and effectiveness of the approach.

• 폴리머
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• 제33권3호
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• pp.219-223
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• 2009

전기방사 공정을 이용하여 제조된 나노파이버는 나노 소자, 필터, 방호닦, 항균성 드레싱 및 약물전달 등 다양한 분야에서 이용되고 있다. 약물전달시스템(drug delivery system, DDS)은 기존 의약품의 부작용을 최소화하며 그 효능 및 효과를 극대화할 수 있어야 하고 필요한 양의 약물을 원하는 환부에 효율적으로 전달할 수 있어야 한다. 본 연구에서는 전기유체역학공정의 하나인 전기방사공정을 이용하여, poly($\varepsilon$-carprolactone)(PCL) poly(ethylene oxide(PEO)를 나노파이버 매트로 만들었으며, 고분자와 동시 방사된 Rhodamine B의 방출량을 측정하였다. PCL/Rhodamine B/PEO/PCL 나노파이버 매트는 전기방사 시간을 통한 두께 조절을 통하여 약물전달 거동이 조절될 수 있음을 확인하였으며, 실제 Peptide를 PEO와 동시 전기방사시켜 얻어진 나노파이버 peptide가 방출되는 거동을 확인하였다. PCL/Peptide/PEO/PCL시스템에서 방출된 peptide는 약물방출 시험 후에도 약물로서의 활성도를 잃지 않았으며, 이러한 나노파이버를 이용한 Peptide 방출메커니즘은 새로운 약물전달시스템으로 적용 및 응용될 수 있을 것으로 예상된다.

• Nuclear Engineering and Technology
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• 제54권6호
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• pp.2135-2146
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• 2022

A nuclear energy facility is one of the most critical facilities to be safely protected during and after operation because the physical destruction of its barriers by an external attack could release radioactivity into the environment and can cause harmful effects. The barrier walls of nuclear energy facilities should be sufficiently robust to protect essential facilities from external attack or sabotage. Physical protection system (PPS) vulnerability assessment of a typical small nuclear research reactor was carried out by simulating an external attack with a tri-nitro toluene (TNT) shaped charge and results are presented. The reinforced concrete (RC) barrier wall of the research reactor located at a distance of 50 m from a TNT-shaped charge was the target of external attack. For the purpose of the impact assessment of the RC barrier wall, a finite element method (FEM) is utilized to simulate the destruction condition. The study results showed that a hole-size of diameter 342 mm at the front side and 364 mm at the back side was created on the RC barrier wall as a result of a 143.35 kg TNT-shaped charge. This aperture would be large enough to let at least one person can pass through at a time. For the purpose of the PPS vulnerability assessment, an Estimate of Adversary Sequence Interruption (EASI) model was used, which enabled the determination of most vulnerable path to the target with a probability of interruption equal to 0.43. The study showed that the RC barrier wall is vulnerable to a TNT-shaped charge impact, which could in turn reduce the effectiveness of the PPS.

• 설비공학논문집
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• 제22권3호
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• pp.156-164
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• 2010

Combustion instability is a major issue in design of gas turbine combustors for efficient operation with low emissions. Combustion instability is induced by the interaction of the unsteady heat release of the combustion process and the change in the acoustic pressure in the combustion chamber. In an effort to develop a technique to predict self-excited combustion instability of gas turbine combustors, a new stability analysis method based on the transfer matrix method is developed. The method views the combustion system as a one-dimensional acoustic system with a side branch and describes the heat source as the input to the system. This approach makes it possible to use not only the advantages of the transfer matrix method but also well established classic control theories. The approach is applied to a gas turbine combustion system, which shows the validity and effectiveness of the approach.

• 대한설비공학회:학술대회논문집
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• 대한설비공학회 2009년도 하계학술발표대회 논문집
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• pp.1449-1457
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• 2009

Combustion instability is a major issue in design of co-generation gas turbine combustors for efficient operation with low emissions. Combustion instability is induced by the interaction of the unsteady heat release of the combustion process and the change in the acoustic pressure in the combustion chamber. In an effort to develop a technique to predict self-excited combustion instability of co-generation gas turbine combustors, a new stability analysis method based on the transfer matrix method is developed. The method views the combustion system as a one-dimensional acoustic system with a side branch and describes the heat source as the input to the system. This approach makes it possible to use not only the advantages of the transfer matrix method but also well established classic control theories. The approach is applied to a simple co-generation gas turbine combustion system, which shows the validity and effectiveness of the approach.

• Journal of Ginseng Research
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• 제37권1호
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• pp.8-29
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• 2013

Ginseng is one of the most widely used herbal medicines in human. Central nervous system (CNS) diseases are most widely investigated diseases among all others in respect to the ginseng's therapeutic effects. These include Alzheimer's disease, Parkinson's disease, cerebral ischemia, depression, and many other neurological disorders including neurodevelopmental disorders. Not only the various types of diseases but also the diverse array of target pathways or molecules ginseng exerts its effect on. These range, for example, from neuroprotection to the regulation of synaptic plasticity and from regulation of neuroinflammatory processes to the regulation of neurotransmitter release, too many to mention. In general, ginseng and even a single compound of ginsenoside produce its effects on multiple sites of action, which make it an ideal candidate to develop multi-target drugs. This is most important in CNS diseases where multiple of etiological and pathological targets working together to regulate the final pathophysiology of diseases. In this review, we tried to provide comprehensive information on the pharmacological and therapeutic effects of ginseng and ginsenosides on neurodegenerative and other neurological diseases. Side by side comparison of the therapeutic effects in various neurological disorders may widen our understanding of the therapeutic potential of ginseng in CNS diseases and the possibility to develop not only symptomatic drugs but also disease modifying reagents based on ginseng.

• Journal of Pharmaceutical Investigation
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• 제13권4호
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• pp.153-172
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• 1983

The use of carrier systems for the delivery of drugs to areas in the body in need of pharmacological intervention is now the subject of intense research in many laboratories. Because of its obvious advantages (e.g. protection of drugs from hostile environments, facilitated target penetration and avoidance of side effects), drug delivery is expected to ease the pressure and expense of new drug development by making better use of drugs in existence. Generally, carrier-mediated delivery has been envisaged either as direct transport of drugs to a biological target by a carrier that will associate with it selectively, or as release of drugs from a carrier circulating in the blood or immobilized in tissues, at rates compatible with optimal action. One system that has attracted considerable attention is the use of liposomes as carriers of pharmacologically active agents. 154 references were reviewed with special emphasis on the targeting of drugs by use of liposomes in this respect. Recent advances in the other carrier systems and in methods for the preparation of liposomes were also reviewed briefly.

• 한국안전학회지
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• 제25권3호
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• pp.40-44
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• 2010

North Korea's discharge of water from a dam into the Imjin River that flows through the inter-Korean border swept away a riverside camping site early Sunday morning, killing six people. This tragic incident might have been prevented if the North had given prior notice of the release from its Hwanggang Dam to the South. Investigations are under way to determine the reasons behind the unexpected act. This incident was a man-made disaster not least death of six people. A water level monitoring system(WLMS) of the Imjin River was installed the bridge of Pilseung that operate three public institutions. The WLMS of the A institution set up warning siren and broadcasting as the water level has been rising the bridge of Pilseung in the Imjin River. But the A institution's system was already out of side before discharged of water a dam into the Imjin River and the operators were culpable negligence. The B institution's office employee on charges of negligence that might have contributed to the tragedy and one of the A institution's employees ignored 26 warning messages on the WLMS. This tragic incident was a man-made disaster not least death of six people and might have been prevented if the WLMS was normally operated and the system operators must be worked a tight.