• Title/Summary/Keyword: shaped charge

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휴대용 경대전차무기(LAW)-무엇이 문제인가

  • Gu, Sang-Hoe
    • Defense and Technology
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    • no.5 s.135
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    • pp.6-17
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    • 1990
  • 최근 Chobham과 같은 특수장갑과 특히 화약을 이용한 반응형장갑의 출현으로 인해 종래의 LAW로는 신형 전차의 파괴가 거의 불가능하게 되었다. 따라서 우리 군이 이러한 제반사항을 심층분석하여 종래의 LAW에 대한 전술운용개념을 유럽각국과 같이 대전차개념과 다목적 대장갑무기 개념으로 2원화시켜 발전시킬 필요가 있다고 판단된다. 종전과 같이 단일 LAW 체계를 계속 유지키로 한다면, 비록 지금은 기술적인 제약으로 LAW의 운용개념을 대장갑기능에 국한하더라도, 장차 Tandem shaped charge 탄두를 갖춘 Panzerfaust-3과 같은 경대전차 무기의 개발이 무엇보다도 시급하다고 믿는다

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FINITE-ELEMENT METHOD FOR THE IMPEDANCE ANALYSIS OF TRAVELING-WAVE MODULATORS

  • JONG CHANG YI
    • Proceedings of the Optical Society of Korea Conference
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    • 1989.02a
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    • pp.165-168
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    • 1989
  • A finite-element method is developed to calculate the impedance of arbitrarily shaped electrodes on traveling-wave modulators. This method employs the divergence theorem to obtain the total charge on an electrode from the node potential values. By using this method, the impedance of multi strip-line electrodes on anisotropic inhomogeneous dielectric media was analysed and the effect of non-zero electrode thickness was calculated.

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Design Parameters for Development of flexible Linear Shaped Charge (가소성 선형 성형폭약 제조를 위한 설계변수에 관한 연구)

  • 박근순;임한욱
    • Tunnel and Underground Space
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    • v.13 no.3
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    • pp.225-234
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    • 2003
  • The structures to be demolished have become diverse in types from reinforced concrete to steel. The demand for demolition of steel structures is recently increasing in Korea. Most of flexible linear-shaped charges for steel demolition are now imported from foreign countries. To determine the optimum parameters of design far domestic development of flexible linear-shaped charges, some basic experiments have been carried out and their results are summarized as follows; Copper is shown to be superior to aluminium and lead as a liner material. It is also proved that the optimum apex angle of liner is 90$^{\circ}$ in comparision with 45$^{\circ}$, 60$^{\circ}$ and 120$^{\circ}$ Adequate thickness of liners, standoff distance in terms of quantity of explosives are also examined. Explosives and liners are required to be plasticized in order to improve the bond between explosives and various shapes of steel structures.

Perspectives on the Composition Facilities of The Royal Garden at Wanggung-ri site, Iksan (익산 왕궁리유적 후원(後苑)의 조성 시설에 관한 고찰)

  • Choi, Moon-Jung
    • Journal of the Korean Institute of Traditional Landscape Architecture
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    • v.32 no.3
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    • pp.1-9
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    • 2014
  • This article is the results of excavation data and it aims to interpret the composition facilities of the Royal garden at the Wanggung-ri site. The base of research was prepared through excavation and study on the royal garden at the Wanggung-ri site, which was constructed in Sa-bi period of Baek-je. The elements for the royal garden at the Wanggung-ri site were divided in 3 parts. - 1) Stonework facility 2) Installation for conveyance of water : Large moat-shaped ditch and Winding waterway(1~6 and water catchment) 3) Square cornerstone building. In this article, I arrange the basic data about facilities and function of the royal garden for making recovery of original form. First of all, I reason that stonework facilities were in charge to make space for catchment and boundary. Especially the Round angel rectangular stonework facility took charge of complex roles as catchment and water conveyance, and water can be transferred to the large moat-shaped ditch through joint between them. I confirmed that the round angel rectangular stonework facility and the large moat-shaped ditch which were connected by joint are one of the facilities in the royal garden. The large moat-shaped ditch protected the eastern, the northern walls and workshop site under the inclined plane to minimize the damage. Also, the large moat-shaped ditch took several roles, especially water catchments and landscaping. The large moat-shaped ditch was continually used from the period of Baek-je to the unified Silla, as a result it was completely deposited inside. After that, the 6 winding waterway were built in the western inclined plane with similar needs with the large moat-shaped ditch, and the square cornerstone building was built in same time. I noticed that the square cornerstone building was built as a part of the royal garden in Sa-bi period of Baek-je through the remains of Baek-je tiles around the building. After that, the square cornerstone building was built in same place as reconstruction.

Numerical Study on Ground Vibration Reduction Performance of Concrete Drainage Protection Facility (콘크리트 배수관로 보호구의 지반진동 저감 성능에 관한 수치해석적 연구)

  • Jung, Seung-Won;Kim, Jung-Gyu;Kim, Jun-Ha;Baluch, Khaqan;Kim, Jong-Gwan
    • Explosives and Blasting
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    • v.39 no.4
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    • pp.12-21
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    • 2021
  • In this study, a series of FEM numerical analyses was conducted to compare the resistance performance of concrete drainage protection facility to blast vibration. Two different types of ㅁ-shaped protection facility, which are suggested in the study, were compared to the traditional ㄷ-shaped one. In the analyses, the vibration resistances of the three protection facilities were evaluated under the varying conditions of the standoff distance from the explosion and charge weight per delay. As a result, it was found that the two proposed types of drainage protection facilities are superior to the traditional one in the vibration reduction performance.

Development of an Inverted Y-Shaped Strip for the Detection of Organophosphorus and Carbamate Residual Pesticides (유기인계 및 카바메이트계 농약 신속 검출을 위한 역 Y자 스트립의 개발)

  • Lee, Jeong-Eun;Kim, Sol-A;Park, Hyun-Jin;Mun, Hyoyoung;Shim, Won-Bo
    • Journal of Food Hygiene and Safety
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    • v.36 no.1
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    • pp.1-8
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    • 2021
  • The inverted Y-shaped strip detection method based on acetylcholinesterase (AChE) was developed for the rapid detection of organophosphorus and carbamate pesticides. The inactivation of AChE by organophosphorus and carbamate pesticides has been well known. The AChE catalyzes acetylthiocholine into thiocholine having (-) and (+) charges, and the (+) charge results in aggregation of gold nanoparticle (GNP). Malaoxon and carbofuran were used as standard organophosphorus and carbamate for the development of the inverted Y-shaped strip, respectively. In order to optimize the method, various angles of the Y-shaped strip, different types of nitrocellulose membrane, and concentration of AChE were tested as key parameters. The detection limit of the method was 10 ng/mL for both malaoxon and carbofuran pesticides. No cross-reaction was observed to other pesticides such as atrazine, cyanazine, simazine, bifenthrin, boscalid, metalaxyl, and chlorobenzilate. Recoveries from lettuce spiked when known concentrations of malaoxon and carbofuran were found ranging from 96.4 to 100.7% and 81 to 112.7%, respectively. This study suggests that the inverted Y-shaped strip method based on AChE may be a useful tool for the sensitive, specific, rapid detection of organophosphorus and carbamate pesticides in agricultural products.

Coupled Thermo-Viscoplastic Three Dimensional Finite Element Anaysis of Compression Molding of Sheet Molding Compound (열유동을 고려한 SMC 압축성형공정의 3차원 유한요소 해석)

  • Kim, Soo-Young;Im, Yong-Taek
    • Transactions of the Korean Society of Mechanical Engineers A
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    • v.20 no.2
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    • pp.488-499
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    • 1996
  • SMC(Sheet molding compound) is a thermosetting material reinforced with chopped fiberglass. The compression molding of SMC was analyzed based on a rigid thermo-viscoplastic approach using a three dimensional finite element program coupled with temperatures. Only the temperature analysis part was tested in this paper by solving one-dimensional heat transfer problem and comparing with the exact solutions available in the literature. Based on this comparison the program was proved to be valid and was further applied in solving compression molding of SMC between flat dies. To investigate the usefulness of a rigid thermo-viscoplastic approach in the compression molding analysis of SMC charge, compression of rectangular shaped SMC charge at plane strain and three dimensionalde formation condition was analyzed under the same condition as given in the literature. From this comparison it was found out that the rigid thermo-viscoplastic approach was useful in analyzing SMC compression molding between flat dies.

Electrical Characteristics of Nano-Structural Monolayer (나노구조 단분자막의 전기적 특성)

  • Choi, Yong-Sung;Cho, Jang-Hoon;Song, Jin-Won;Lee, Kyung-Sup
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 2006.11a
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    • pp.166-167
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    • 2006
  • Dendrimers represent a new class of synthetic macromolecules characterized by a regularly branched treelike structure. Multiple branching yields a large number of chain ends that distinguish dendrimers from conventional star-like polymers and microgels. The azobenzene dendrimer is one of the dendrimeric macromolecules that include the azo-group exhibiting a photochromic character. Due to the presence of the charge transfer element of the azo-group and its rod-shaped structure, these compounds are expected to have potential interest in electronics and photoelectronics, especially in nonlinear optics. In the present paper, we give pressure stimulation to organic thin films and detect the induced displacement current. Functional photoisometrization organic molecular the photo-stimulus to organic monomolecular L-films and LB films of dendrimer and 8A5H were performed. The 8A5H organic monolayer in case of pressure stimulus occurred that positive course but in case of the photo-stimulus compared positive and negative. It is assumed that generation forms of displacement current were measured when photo-stimulus for Impression.

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A Study of Electrical Characteristics of Nano-Structural Monolayers (나노구조 단분자막의 전기적 특성 연구)

  • Song, Jin-Won;Shin, Hoon-Kyu;Lee, Kyung-Sup;Choi, Yong-Sung
    • The Transactions of the Korean Institute of Electrical Engineers C
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    • v.55 no.12
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    • pp.586-590
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    • 2006
  • Dendrimers represent a new class of synthetic macromoleculcs characterized by a regularly branched treelike structure. Multiple branching yields a large number of chain ends that distinguish dendrimers from conventional star-like polymers and microgels. The azobenzene dendrimer is one of the dendrimeric macromolecules that include the azo-group exhibiting a photochromic character. Due to the presence of the charge transfer element of the azo-group and its rod-shaped structure, these compounds are expected to have potential interest in electronics and photoelectronics, especially in nonlinear optics. In the present paper, we give pressure stimulation to organic thin films and detect the induced displacement current. Functional photoisometrization organic molecular the photo-stimulus to organic monomolecular L films and LB films of dendrimer and 8A5H were performed. The 8A5H organic monolayer in case of pressure stimulus occurred that positive course but in case of the photo-stimulus compared positive and negative. It is assumed that generation forms of displacement current were measured when photo-stimulus for impression.

Blast Fragility and Sensitivity Analyses of Steel Moment Frames with Plan Irregularities

  • Kumar, Anil;Matsagar, Vasant
    • International journal of steel structures
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    • v.18 no.5
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    • pp.1684-1698
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    • 2018
  • Fragility functions are determined for braced steel moment frames (SMFs) with plans such as square-, T-, L-, U-, trapezoidal-, and semicircular-shaped, subjected to blast. The frames are designed for gravity and seismic loads, but not necessarily for the blast loads. The blast load is computed for a wide range of scenarios involving different parameters, viz. charge weight, standoff distance, and blast location relative to plan of the structure followed by nonlinear dynamic analysis of the frames. The members failing in rotation lead to partial collapse due to plastic mechanism formation. The probabilities of partial collapse of the SMFs, with and without bracing system, due to the blast loading are computed to plot fragility curves. The charge weight and standoff distance are taken as Gaussian random input variables. The extent of propagation of the uncertainties in the input parameters onto the response quantities and fragility of the SMFs is assessed by computing Sobol sensitivity indices. The probabilistic analysis is conducted using Monte Carlo simulations. The frames have least failure probability for blasts occurring in front of their corners or convex face. Further, the unbraced frames are observed to have higher fragility as compared to counterpart braced frames for far-off detonations.