• Title/Summary/Keyword: Explosive performance

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Characteristics of polymer arrester with pressure relief structure (폴리머 피뢰기의 방압구조 및 특성)

  • Han, Dong-Hee;Cho, Han-Goo;Han, Se-Won
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 2004.07b
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    • pp.1109-1112
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    • 2004
  • This study reports on the pressure relief design and braided composite of surge arrester. Surge arresters with porcelain housing must not have explosive breakage of the housing to minimize damage to other equipment when subjected to internal high short circuit current. As a solution, this study describes pressure relief design performance of arresters with braided composite module. In general, braided composite has Potential for improved impact and delamination resistance. Manufacturing processes of the braided composite could also be automated and could potentially lead to lower costs. Therefore, in consideration of characteristics of pressure relief for polymer arrester, the fabric pattern of braided composite was decided. And Polymer arrester module was manufactured with braid. The mechanisms of pressure occurrence and relief were investigated basically by analyzing arc energy and the correlation between thermal shock and indoor pressure in pressure relief test.

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A Study on Design and Performance of a Heat pipe for the application to Solar collector (태양열 집열기용 열파이프의 구조와 작동 특성에 관한 연구)

  • 임광빈;김철주;박이동;황영규;강환국
    • Proceedings of the Korea Society for Energy Engineering kosee Conference
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    • 1993.05a
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    • pp.70-78
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    • 1993
  • Heat pipes, applied to flat plate solar collectors, have a long and slender configuration with relatively low heat flux on the evaporator. Such a heat pipe has a tendency to build-up a liquid pool at the lower half of evaporator zone, and at this pool occurs such complicated phenomena of evaporation and fluid dynamics as superheat, sudden generation of bubble, its likely explosive growth process and flooding etc. In the present study, we tried to solve those problems by means of adjusting the two principle design parameters, liquid fill charge and wick length, using 4 heat pipes and 3 thermosyphons, with different values of parameter respectively. The corresponding results can be summarized as followings, - The thermal conductance of heat pipes was largely improved by el eliminating wick from adiabatic and condenser zone. - But on evaporator zone wick is inevitable to reduce behavior of the build -up of liquid pool , where arise diverse internal complex phenomena. - The liquid fill charge should have to be increased by 10∼20% more than the quantity to saturate the wick.

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Performance Evaluation of Hinge Driving Separation Nut-type Holding and Releasing Mechanism Triggered by Nichrome Burn Wire

  • LEE, Myeong-Jae;LEE, Yong-Keun;OH, Hyun-Ung
    • International Journal of Aeronautical and Space Sciences
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    • v.16 no.4
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    • pp.602-613
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    • 2015
  • As one of the mission payloads to be verified through the cube satellite mission of Cube Laboratory for Space Technology Experimental Project (STEP Cube Lab), we developed a hinge driving separation nut-type holding and releasing mechanism. The mechanism offers advantages, such as a large holding capacity and negligible induced shock, although its activation principle is based on a nylon cable cutting mechanism triggered by a nichrome burn wire generally used for cube satellite applications for the purpose of holding and releasing onboard appendages owing to its simplicity and low cost. The basic characteristics of the mechanism have been measured through a release function test, static load test under qualification temperature limits, and shock measurement test. In addition, the structural safety and operational functionality of the mechanism module under launch and on-orbit environments have been successfully demonstrated through a vibration test and thermal vacuum test.

Reservation based Resource Management for SDN-based UE Cloud

  • Sun, Guolin;Kefyalew, Dawit;Liu, Guisong
    • KSII Transactions on Internet and Information Systems (TIIS)
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    • v.10 no.12
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    • pp.5174-5190
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    • 2016
  • Recent years have witnessed an explosive growth of mobile devices, mobile cloud computing services offered by these devices and the remote clouds behind them. In this paper, we noticed ultra-low latency service, as a type of mobile cloud computing service, requires extremely short delay constraints. Hence, such delay-sensitive applications should be satisfied with strong QoS guarantee. Existing solutions regarding this problem have poor performance in terms of throughput. In this paper, we propose an end-to-end bandwidth resource reservation via software defined scheduling inspired by the famous SDN framework. The main contribution of this paper is the end-to-end resource reservation and flow scheduling algorithm, which always gives priority to delay sensitive flows. Simulation results confirm the advantage of the proposed solution, which improves the average throughput of ultra-low latency flows.

Modeling and control of a solenoid for high-speed actuation (솔레노이드의 고속 동작을 위한 모델링 및 제어)

  • Yoo, Seung-Ryeol;Shin, Dong-Hun
    • Journal of the Semiconductor & Display Technology
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    • v.10 no.4
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    • pp.1-5
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    • 2011
  • Electronics in modern life have become more miniaturized and precise and new technology of electronic components has made these trends possible. The explosive demand of electronic components needs more high-speed and accurate performance of manufacturing processes. For high-speed actuation, solenoids, voice coil motors and piezo motors have been used. A solenoid actuator characterized by low price, available small size, and convenience is one of the main components of production equipments requiring compact and high-speed actuators. Since these actuators show millisecond order responsiveness, the improvement of 1~2msec is very important in industrial applications. In this paper, the mathematical model of the solenoid is formulated and simulated using SIMULINK$^{(R)}$. To verify the model, the responses for step input with open-loop control is obtained and compared with the simulation result. In order to improve the responsiveness, Hold voltage method is introduced and optimal value between spring constant and hold voltage is suggested.

Improvement of Network Traffic Monitoring Performance by Extending SNMP Function

  • Youn Chun-Kyun
    • Proceedings of the IEEK Conference
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    • summer
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    • pp.171-175
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    • 2004
  • Network management for detail analysis can cause speed decline of application in case of lack band width by traffic increase of the explosive Internet. Because a manager requests MIB value for the desired objects to an agent by management policy, and then the agent responds to the manager. Such processes are repeated, so it can cause increase of network traffic. Specially, repetitious occurrence of sending-receiving information is very inefficient for a same object when a trend analysis of traffic is performed. In this paper, an efficient SNMP is proposed to add new PDUs into the existing SNMP in order to accept time function. Utilizing this PDU, it minimizes unnecessary sending-receiving message and collects information for trend management of network efficiently. This proposed SNMP is tested for compatibility with the existing SNMP and decreases amount of network traffic largely

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Classifying Biomedical Literature Providing Protein Function Evidence

  • Lim, Joon-Ho;Lee, Kyu-Chul
    • ETRI Journal
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    • v.37 no.4
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    • pp.813-823
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    • 2015
  • Because protein is a primary element responsible for biological or biochemical roles in living bodies, protein function is the core and basis information for biomedical studies. However, recent advances in bio technologies have created an explosive increase in the amount of published literature; therefore, biomedical researchers have a hard time finding needed protein function information. In this paper, a classification system for biomedical literature providing protein function evidence is proposed. Note that, despite our best efforts, we have been unable to find previous studies on the proposed issue. To classify papers based on protein function evidence, we should consider whether the main claim of a paper is to assert a protein function. We, therefore, propose two novel features - protein and assertion. Our experimental results show a classification performance with 71.89% precision, 90.0% recall, and a 79.94% F-measure. In addition, to verify the usefulness of the proposed classification system, two case study applications are investigated - information retrieval for protein function and automatic summarization for protein function text. It is shown that the proposed classification system can be successfully applied to these applications.

A study on the characteristic of fire protection covering for high strength concrete (고강도 콘크리트 내화피복 특성연구)

  • Song, Young-Chan;Lee, Sea-Hyun;Kim, Woo-Jae;Yang, Wan-Hee;Park, Dong-Cheol;Baik, Byung-Hoon
    • Proceedings of the Korea Concrete Institute Conference
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    • 2006.11a
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    • pp.429-432
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    • 2006
  • In this study a board was made with good fireproof materials of which test was conducted according to the fireproof test for KS F 2257 construction members, and the temperature in coated steel which has a possibility to explode with concrete surface was measured. It is not appropriate to use normal mortar or mortar covering mixed with P.P. fiber to take a measure to prevent the explosive splalling of high-strength concrete. To finalize an Al-Si (aluminosilicates) board-requires over 30mm in thickness at the minimum for the required fire resistance performance and explosion prevention.

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Fabrication and Characteristics of High-performance Doped-$SnO_2$ Thin Films for Explosive Gas Sensor

  • Chwa, Sang-Ok;Park, Hee-Chan;Kim, Kwang-Ho
    • The Korean Journal of Ceramics
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    • v.2 no.2
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    • pp.83-88
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    • 1996
  • Long term stability, sensitization in air, and gas sensing behaviors of tin oxide films were investigated with doping of antimony and palladium. The tin oxide films were prepared on a Corning glass by reactive rf sputtering method and tested for detection of hydrogen gas. Sb-doping improved a long-term stability in the base resistance of $SnO_2$ film sensor. A small amount of Pd doping caused the optimum sensor operating temperature to reduce and also enhanced the gas sensitivity, compared with the undoped $SnO_2$ film. Gas sensitivity depended largely on the film thickness. The important sensitization reactions for sensor operating were $(O_{2ads})+e^-\;{\rightarrow}\;2(O_{ads})^-$ on the surface of $SnO_2$ film at elevated temperature in air and a followed reaction of hydrogen atoms with $(O_{ads})^-$ ions.

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Research on the Penetrator Characteristics and Flight Stability of Explosively Formed Penetrator (EFP 관통자 특성과 비행 안정성에 대한 연구)

  • Yi, Youngsun
    • Journal of the Korea Institute of Military Science and Technology
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    • v.23 no.4
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    • pp.355-362
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    • 2020
  • EFP composed of explosive, charge and liner generally penetrates standoff a target by Monroe effect. Its performance highly depends on penetrator characteristics and flight stability. Penetration ability can be dramatically reduced when the penetrator reaches the target with AOA, even if the penetrator has high kinetic energy and L/D ratio. Therefore, it is important to research not only penetrator characteristics and but also flight stability. In this work, the effect of liner shape on penetrator characteristics was examined using free flight test and numerical tools. It was found that tip velocity of penetrator was increased with decreasing liner thickness. It was also found that thicker liner had higher static margin leading to better flight status.