• 한국화재소방학회논문지
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• 제30권3호
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• pp.79-85
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• 2016

원자력발전소의 방화지역에서 전기적인 단락, 지락, 전기회로 개방 등의 전기 문제로 화재가 발생할 수 있다. 전기 화재가 발생할 경우 안전계통 및 관련기기의 안전정지 기능이 상실된다. 이러한 사고를 예방하기 위하여 안전계통은 다중성, 독립성으로 설계되어 있다. 그러나 케이블 화재시 운전원은 오동작, 잘못된 지시 및 계측으로 발전소 상황을 잘 못 판단하여 적절한 조치를 하지 못할 수 있다. 따라서 주제어실 화재시 케이블 기능상실온도에서 최소 운전원 조치 요구시간인 5분은 매우 중요하다. 본 논문에서 주제어실 화재시 케이블의 기능상실온도 시간을 분석하여 운전원 조치시간이 충분한지 평가하여 주제어실 화재에 대한 안전성을 확인하였다.

• Structural Engineering and Mechanics
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• 제78권3호
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• pp.231-253
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• 2021

Pure bending loading conditions are not frequently occurred in practical engineering, but the flexural researches are important since it's the basis of mechanical property researches under complex loading. Hence, the objective of this paper is to investigate the flexural behavior of concrete-filled rectangular steel tube (CFRT) through combined experimental and numerical studies. Flexural tests were conducted to investigate the mechanical performance of CFRT under bending. The load vs. deflection curves during the loading process was analyzed in detail. All the specimens behaved in a very ductile manner. Besides, based on the experimental result, the composite action between the steel tube and core concrete was studies and examined. Furthermore, the feasibility and accuracy of the numerical method was verified by comparing the computed results with experimental observations. The full curves analysis on the moment vs. curvature curves was further conducted, where the development of the stress and strain redistribution in the steel tube and core concrete was clarified comprehensively. It should be noted that there existed bond slip between the core concrete and steel tube during the loading process. And then, an extensive parametric study, including the steel strength, concrete strength, steel ratio and aspect ratio, was performed. Finally, design formula to calculate the ultimate moment and flexural stiffness of CFRTs were presented. The predicted results showed satisfactory agreement with the experimental and FE results. Additionally, the difference between the experimental/FE and predicted results using the related design codes were illustrated.

• 농약과학회지
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• 제2권3호
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• pp.126-136
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• 1998

신규화합물인 thiamethoxam의 목화진딧물과 배추좀나방에 대한 살충효과를 분석하기 위하여 일반적인 생물검정 방법을 이용하여 접촉 및 섭식독성반응과 속효성, 침투이행성, 잔효성 등을 다른 약제들과 비교 검토하였다. Spray법을 이용하여 접촉독성을 조사한 결과 목화진딧물에 대한 반수치사농도($LC_{50}$)는 유기인계인 acephate 41.9 ppm, 카바메이트인 carbosulfan 5.2 ppm, 니코틴계인 imidacloprid와 thiamethoxam은 각각 1.1, 0.7 ppm을 나타냈다. 배추좀나방을 대상으로 엽침적법으로 처리했을 경우 섭식독성은 2령 유충의 경우 $LC_{50}$값이 imidacloprid 64.9 ppm, thiamethoxam 24.6 ppm, acetamiprid 15.2 ppm, 3령 유충에서는 각각 125.1, 42.7, 27.8 ppm이었고, 4령 유충에서는 각각 241.1, 44.5, 23.9 ppm으로 령기별로 약간의 차이를 보였다. 한편, 목화진딧물을 대상으로 한 약제의 속효성을 측정하는 반수치사시간 ($LT_{50}$)은 접종 후 약제살포시에 imidaclopid 26.6분, thiamethoxam 28.0분, carbosulfa 30.3분, acephate 41.7분의 순이었고, 약제살포 후 접종하였을 때에는 thiamethoxam 95.5분, imidaclopid 118.0분, carbosulfan 122.9분으로 진딧물에 직접 살포한 것이 살충시간을 단축시켰다. 또한, 잎표면으로부터 이면으로의 약효성분의 이행성을 비교한 결과 $LT_{50}$값은 thiamethoxam 162.2분, imidacloprid 168.9분, carbosulfan 564.1분이었고, 하위 잎으로부터 최상위 잎으로의 이행성에서는 carbosulfan 2.3일, thiamethoxam 2.9일, imidacloprid 3.0일, acephate 8.8일이었다. 뿌리로부터 잎으로의 이행성은 carbosulfan 0.6일, imidacloprid 1.0일, thiamethoxam 1.0일, acephate 13.8일로서 thiamethoxam의 침투이행성이 가장 빠른 것으로 나타났다. Spray법을 이용한 잔효성 시험결과 thiamethoxam과 imidaclopid는 약제처리 후 10일째에도 80%이상의 높은 살충효과를 나타내어 잔효성이 우수하였다.

• Biomolecules & Therapeutics
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• 제8권1호
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• pp.93-98
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• 2000

This study has been carried out to investigate general pharmacological action of bamboo salt (jukyom) in terms of effects on central nervous system and cardiovascular system in experimental animals. After bamboo salt, crude salt or reagent-grade NaCl were orally administered into male ICR mice with dose of 2.0 g/kg, general behavioural syndromes such as body weight and locomotor activity, spontaneous motor activity, pento-barbital-induced sleeping time, muscle incoordination, electroshock-induced convulsion, body temperature and writhing response caused by 0.6% acetic acid solution were observed. Bamboo salt had no influences in these indices for examinition of effect on central nervous system. Additionally, conscious male Sprague Dawley rats fastened overnight won ere treated with bamboo salt, crude salt or reagent-grade NaCl (2.0 g/kg, p.o.) to examine the effect of these salts cardiovascular system. Systolic, median and diastolic food pressure and heart rate were dertemined using tail cuff indirect method. Treatment with Hydralazine (50 mg/kg, p.o) as a positive control produced the decreases in systolic, median and diastolic blood treasure and an increase in heart rate. whereas no changes were observed in bamboo salt, crude salt and reagent-grade NaCl treated groups. These results strongly suggest that bamboo salt may have no effects on general pharmacology of central nervous systems and cardio-vascular systems.

• International Journal of Aeronautical and Space Sciences
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• 제11권4호
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• pp.285-302
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• 2010

Active aeroelastic control is an emerging technology aimed at providing solutions to structural systems that under the action of aerodynamic loads are prone to instability and catastrophic failures, and to oscillations that can yield structural failure by fatigue. The purpose of the aeroelastic control among others is to alleviate and even suppress the vibrations appearing in the flight vehicle subcritical flight regimes, to expand its flight envelope by increasing the flutter speed, and to enhance the post-flutter behavior usually characterized by the presence of limit cycle oscillations. Recently adaptive and robust control strategies have demonstrated their superiority to classical feedback strategies. This review paper discusses the latest development on the topic by the authors. First, the available control techniques with focus on adaptive control schemes are reviewed, then the attention is focused on the advanced single-input and multi-input multi-output adaptive feedback control strategies developed for lifting surfaces operating at subsonic and supersonic flight speeds. A number of concepts involving various adaptive control methodologies, as well as results obtained with such controls are presented. Emphasis is placed on theoretical and numerical results obtained with the various control strategies.

• Archives of Pharmacal Research
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• 제22권6호
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• pp.565-570
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• 1999

DW2282,(S)-(+)-4-phenyl-1-[1-(4-aminobenzoyl)-indoline-5-sulfonyl]-4,5-dihydro-2-imidazolone hydrochloride, is a new anticancer agent which is thought to exhibit a characteristic mechanism of action in the inhibition of tumor growth. In this study, we estimated the toxicities of DW2282 in mice. When mice were orally dosed for five consecutive days at the dosages of 50, 100 and 150 mg/kg, DW2282 did not induced methemoglobinemia and hypoglycemia at any of these doses. However, increased ALT and AST values were observed in the 150 mg/kg dosing group, and white blood cells (WBC) were significantly decreased at all doses. However, the changes in WBC count, ALT and AST immediately reversed after the cessation of drug administration. In addition, we found that DW2282 did not cause an increase in hemolysis in human blood. Taken together, these data suggested that DW2282 may have a relatively low level of toxicity, and that there may be a quick recovery from any toxicity it dose produce.

• Earthquakes and Structures
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• 제13권6호
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• pp.551-559
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• 2017

A large number of isolation systems are designed without considering the non-uniform friction distribution in space. In order to analyze the effects of non-uniform friction distribution on the structural response of isolation system, this paper presented a simplified rolling-damper-spring isolation system and analyzed the structural responses under earthquakes. The numerical results indicate that the calculation errors related to the peak values of structural acceleration, relative displacement and residual displacement are sequentially growing because of the ignorance of non-uniform friction distribution. However, the influence rule may be weakened by the spring and damper actions, and the unreasonable spring constant may lead to the sympathetic vibration of isolation system. In the case when the friction variability is large and the damper action is little, the non-uniform friction distribution should be taken into consideration during the calculation process of the peak values of structural acceleration and relative displacement. The non-uniform friction distribution should be taken into full consideration regardless of friction variability degree in calculating the residual displacement of isolation system.

• Structural Engineering and Mechanics
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• 제81권5호
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• pp.591-606
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• 2022

When the friction pendulum system and shear keys work together to resist the ground motion, which inclined inputs (non 45°) to the bridge structure, the shear keys in XY direction will be sheared asynchronously, endowed the friction pendulum system with a violent curvilinear motion on the sliding surface during earthquakes. In view of this situation, firstly, this paper abandons the equivalent linearization model of friction and constructs a Spring-Coulomb friction plane isolation system with XY shear keys, and then makes a detailed mechanical analysis of the movement process of friction pendulum system, next, this paper establishes the mathematical model of structural time history response calculation by using the step-by-step integration method, finally, it compiles the corresponding computer program to realize the numerical calculation. The results show that the calculation method in this paper takes advantage of the characteristic that the friction force is always µmg, and creatively uses the "circle making method" to express the change process of the friction force and resultant force of the friction pendulum system in any calculation time step, which can effectively solve the temporal nonlinear action of the plane friction; Compared with the response obtained by the calculation method in this paper, the peak values of acceleration response and displacement response calculated by the unidirectional calculation model, which used in the traditional research of the friction pendulum system, are smaller, so the unidirectional calculation model is not safe.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제17권2호
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• pp.559-575
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• 2023

3D human pose estimation is widely applied in various fields, including action recognition, sports analysis, and human-computer interaction. 3D human pose estimation has achieved significant progress with the introduction of convolutional neural network (CNN). Recently, several researches have proposed the use of multiview approaches to avoid occlusions in single-view approaches. However, as the number of cameras increases, a 3D pose estimation system relying on a CNN may lack in computational resources. In addition, when a single host system uses multiple cameras, the data transition speed becomes inadequate owing to bandwidth limitations. To address this problem, we propose a distributed real-time 3D pose estimation framework based on asynchronous multiple cameras. The proposed framework comprises a central server and multiple edge devices. Each multiple-edge device estimates a 2D human pose from its view and sendsit to the central server. Subsequently, the central server synchronizes the received 2D human pose data based on the timestamps. Finally, the central server reconstructs a 3D human pose using geometrical triangulation. We demonstrate that the proposed framework increases the percentage of detected joints and successfully estimates 3D human poses in real-time.

• 대한약리학회지
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• 제27권2호
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• pp.99-108
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• 1991

Racemic ketamine을 사용하여 개구리의 좌골신경 및 toe muscle에 대한 작용을 관찰하였다. 실험방법으로는 214 mM sucrose을 사용하여 서로 다른 두 종류의 투여 방법으로 세포막의 활동 전압에 대한 영향을 electric recording으로 관찰하였다. 즉, intracellular 투여는 single sucrose gap technique으로, extracellar 투여는 double sucrose gap technique을 사용하였으며 그 실험 결과는 아래와 같았다. 1. Racemic ketamine은 개구리의 좌골신경 및 toe muscle의 활동전압을 intracellular 및 extracellular 투여시 모두 의의 있게 억제하였다. 2. 개구의 toe muscle에서 $K^+$-수축을 억제하였다. 3. naloxone은 ketamine의 억제작용을 완전히 차단하지는 못하였다.