• 제목/요약/키워드: gun

검색결과 13,039건 처리시간 0.035초

기계적 필터를 이용한 포신형상 구조물의 진동신호 측정 (Measurement of Vibration Signals of a Gun Barrel Type Structure using Mechanical Filter)

  • 류봉조;이규섭;신광복;오부진
    • 한국소음진동공학회:학술대회논문집
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    • 한국소음진동공학회 2007년도 춘계학술대회논문집
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    • pp.181-184
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    • 2007
  • This paper deals with the method of vibration measurement of a gun barrel structure using mechanical filter. When a bullet with high speed is moving within a gun barrel type structure with low bending vibration frequencies, it is difficult to measure the bending vibration signals of the structure. For example, noncontact type sensors such as displacement or velocity sensor are not appropriate for the measurement of vibrational signals because of the movement effect of the equipment frame through the moving structures or effect of the ground vibration. One of contact type sensors such as accelerometer is profitable for measurement of vibrational signals because of its wide measurement ranges. In the case of a gun barrel structure including high vibrational signals like shock waves, however, it is necessary to propose vibration measurement method filtering high frequencies. The purpose of the paper is to propose the proper vibrational measurement technique filtering high frequencies of a gun barrel type structure.

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난지형 마늘의 농업수리학적 재배적지 분류 (Water Balance-based Farmland Suitability for Southern-type Garlic Cultivation)

  • 김용완;홍석영;김이현;장민원
    • 한국농공학회논문집
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    • 제54권6호
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    • pp.19-28
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    • 2012
  • This study carried out farmland suitability analysis for southern-type garlic cultivation considering soil and temperature as well as water deficit conditions. The spatial extent was limited within the area derived by Kim et al. (2012) using just soil and temperature constraints. Daily soil moisture was simulated using a one-layer soil water balance model at a $100{\times}100m$ grid unit, and then annual water deficit was calculated from 2000 to 2010. The farmland suitability was classified as four steps: best suitable, suitable, possible, and low productive. As a result, total area of best suitable or suitable farmland was about 375,900 ha, and Gimje-si and Haenam-gun were appeared as the largest favorable area for southern-type garlic cultivation. The best suitable or suitable area at Haenam-gun, Goheung-gun, Shinan-gun, Namhae-gun, and Muan-gun, major production regions of southern-type garlic, were extracted as 20,187 ha, 13,018 ha, 4,715 ha, 1,319 ha, and 349 ha, respectively. On the other hand, the result showed that the adoption of sprinkler irrigation systems might be critical in cultivating the southern-type garlic at some regions having poor water balance.

Fundamental Aspects of the Unbalance Condition for the Forces involved in Rail Gun Recoil

  • Banerjee, Arindam;Radcliffe, P.J.
    • Journal of international Conference on Electrical Machines and Systems
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    • 제3권3호
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    • pp.317-324
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    • 2014
  • The forces involved in the firing of the electromagnetic rail gun may be analyzed from Amperian, Maxwellian and Einsteinian approaches. This paper discusses these different paradigms with regard to rail gun performance modeling relating to the generation and balance of the forces caused by the currents and their induced magnetic fields. Recent experimental work on model rail guns, where the armature is held static, shows very little recoil upon the rails, thereby indicating a possible violation of Newton's Third Law of Motion. Dynamic testing to show this violation, as suggested by the authors in an earlier paper, has inherent technical difficulties. A purpose-built finite element C/C++ simulator that models that suspended rail gun firing action shows a net force acting upon the entire rail gun system. A new effect in physics, universal in scope, is thus indicated: a current circulating in an asymmetric and rigid circuit causes a net force to act upon the circuit for the duration of the current. This conclusion following from computer simulation based upon Maxwellian electrodynamics as opposed to the more modern relativistic quantum electrodynamics needs to be supported by unambiguous experimental validation.

경관보전직불제 시범사업의 시행사례 분석 및 개선방안: 봉화군, 청원군, 홍성군 사례를 중심으로 (Improvement Strategy by Case Study on the Direct Payment Program for Rural Landscape Preservation: Bonghwa-gun, Chungwon-gun, Hongsung-gun)

  • 장효선;김은순;엄대호
    • 농촌계획
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    • 제13권4호
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    • pp.69-77
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    • 2007
  • The purpose of this study is to analyze the problems of operating the Direct Payment Program for Rural Landscape Preservation and to derive the way of improvement based on case study for three areas in Bonghwa-gun, Cheongwon-gun, Hongseong-gun. The most important factor for the program is farmer's consciousness and positive participation of the farmer who are the subject of this project. Even if farmers are not satisfied with the amount of direct payment income, they try to create income by utilizing landscape preservation crops. Particularly current unit payment dose not surpass the for the crops farm operating costs and payment time is not appropriate for the farming cycle. Hence, it needs to be considered increasing unit payment and rearranging the payment time. Also, we need to introduce incentive system based the degree of fulfillment of the Direct Payment Program in each areas. In general the Direct Payment Program for Rural Landscape Preservation has potentiality to contribute farmer's income stability and the vitalization of region with three revisions.

석조문화재의 암석에 관한 지질학적 조사 연구 (I)-원주시, 원주군, 횡성군 및 홍천군 지역을 중심으로 (Geological Study on the Rocks of the Stone-Monuments-at the around the weonju City, Weonju-gun, Hwoengseong-gun and Hongcheon-gun)

  • 이상헌
    • 보존과학연구
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    • 통권13호
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    • pp.14-36
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    • 1992
  • The investigation has been made on the rocks consisting the pagoda(12), Buddhist Statues(9) Buldaejwa and cakra(2, rewpectively), stele(5), and Flagpole wupport and stupa(6) which are stood in Weonju city, Weonju-gun, Hwoengseong-gun and Hongcheon-gun, Kangweondo. These rock-monuments range mostly in age from late Shilla Kingdom to middle Korye Kingdom. The geology around this region is mainly composed of Precambrian metamorphic rocks and mesozoic granitic rocks. The granitic rocks are largely divided into Jurassic and cretaceous ones which are slightly different in rock phase. The main rock phase consisting the monumentsare are coarse biotite granite with minor amount of hornblende in Jurassic age. Variation in rock phase is abserved even in part of the stone used in the monuments. Inclusions composed of biotite and hornblende, porphyritic texture with microcline phenocryst, igneous lineation and exfoliation according to weathering are observable in all rocks in these monuments. In the case of stele whose a body and a capstone is remained, one is composed of black slate and the other white limestone. But the turtle shaped pedestal is constituted of coarse biotite granite. These stone-monuments are strongly weathered and exfoliated out about 1∼2mm.In case of exfoliated weathering along igneous lineation, some are taken off about 3∼5mm thick. In some monuments, the degree of weathering is somewhat different according to position, grade of sculpture, and biological activity.

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차열관을 이용한 포신의 진동 감쇠에 대한 연구 (A study on the Vibration Damping of a gun barrel using Dynamically Tuned Shroud)

  • 고재민;김견식;김진우;정현우;황재혁;배재성
    • 항공우주시스템공학회지
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    • 제4권4호
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    • pp.28-36
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    • 2010
  • Current tanks have been developed to increase mobility and firepower, and its maximum range and destructive power are improved. This great change causes remained vibration of a gun barrel after firing. For this reason, people are trying to control vibration of gun barrel effectively. This thesis presents a modeling method and analysis results for gun barrel by using a thermal shroud as an absorber mass. DTS(Dynamically Tuned Shroud) is a vibration damping system using a thermal shroud as an added mass for decreasing remained vibration. The model has an advantage that the gun barrel's vibration can be decreased by dissipating a kinetic energy of thermal shroud without install an additional dynamic absorber to tip of the gun barrel. For analyzing the damping performance of the DTS, We derived an equation of motion of the barrel after setting a mathematical modeling, and found out the frequency analysis and tendency according to stiffness ratio between barrel and shroud.

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가미향사육군자탕(加味香砂六君子湯)의 Indomethacin 유도 위점막손상 에 미치는 항산화효과(抗酸化效果) (Antioxidant Effects of GaMiHyangSaYukGunJaTang against Gastric Mucosal Lesions induced by Indomethacin)

  • 김경선;신흥묵
    • 대한한의학회지
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    • 제19권1호
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    • pp.165-178
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    • 1998
  • This study was carried out to investigate the protective effects of GaMiHyangSaYukGunJaTang on gastric mucosal lesions caused by indomethacin in rats.The test group was injected with indomethacin after the oral administration of GaMiHyangSaYukGunJaTang, while the control group was injected only with indomethacin. The lipid peroxidation level increased considerably in the control group, but superoxide disnurtase(SOD), catalase and glutathione(GSH) levels remarkably decreased. The following effects induced by indomethacin were observed in the stomach of the control group; mucosa hemoIThagic infarct, mucosa cell necrosis, leukocyte appearance, mucosa hemorrhagic erosion and gastric pit disawearance. In the test group, lipid peroxides level was significantly reduced compared with the control group While SOD, catalase and GSH levels considerably increased. The following effects were also observed in the stomach of the test group; mucosa hemorrhagic infarct, mucosa cell necrosis, leukocyte appearance and mucosa hemorrhagic erosion occured far less and gastric pit disappearance was not observed at all. This results suggest that GaMiHyangSaYukGunJaTang is effective in the remedy of gastric mucosal lesions as GaMiHyangSaYukGunJaTang suppresses the production of the lipid peroxides and free radicals induced by indomethacin and activates SOD, catalase and GSH.

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인제군 지역 활성화를 위한 인프라 구축에 관한 연구 - 도시조형공원 구축을 중심으로 - (A Study on the Establishment of Infrastructure for Revitalization of Inje gun -Focusing on the Construction of an Urban Art Park-)

  • 서명석
    • 문화기술의 융합
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    • 제6권2호
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    • pp.333-340
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    • 2020
  • 강원도 인제군민의 질 높은 생활을 향유하기 위하여 인제군의 지역 활성화를 위한 인프라 구축에 관하여 연구한 결과 인제군의 군민이 쉽게 접근이 가능하고 이용이 용이한 대상 부지를 분석한 결과 공원의 유형은 삶의 질을 높이고 도시 문화적인 체험과 휴식을 취 할 수 있으며, 정서생활의 증진을 도모할 수 있는 도시조형공원이 가장 적합한 것으로 분석된다. 전국에 지자체마다 생태공원, 테마공원, 체험공원 등은 많은 존재하고 있으나 인제군만의 특징을 담아내며 차별화를 이룰 수 있도록 도시공원 형태로 계획함이 바람직하다.

강선율 최적설계에 관한 연구 (A Study on the Optimal Design of Rifling Rate)

  • 차기업;이영현;이성배;조창기
    • 한국군사과학기술학회지
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    • 제13권6호
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    • pp.998-1005
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    • 2010
  • Rifling force has a torsion impulse effect on the gun tube and thus generates undesirable vibration of the gun tube about its bore axis, putting additional stress on the projectile. High rifling force at the muzzle of the gun tube may adversely influence the trajectory of the projectile. And, the service life of rifled gun barrels is known to depend on the rifling force. Rifling force along the path of the projectile in the longitudinal direction of the gun tube can be described with projectile mass, projectile velocity, gas pressure curve and rifling angle. Under the same conditions, the character of the rifling of the gun barrel decisively influences the rifling force curve. To reduce the above mentioned harmful effect, locally distinct maximum of rifling force has to be avoided and maximum rifling force needs to be minimized. The best way to minimize the maximum rifling force is to design a rifling angle function so that the rifling force curve has a near trapezoidal shape. In this paper a new approach to make the optimal rifling force curve is described. The rifling angle determining the rifling force is developed by combined Fourier series and polynomial function to satisfy both the convergence and boundary condition matching problems.

육군자탕(六君子湯)이 Cyclophosphamide로 손상(損傷)된 비장조직(脾臟組織)의 회복(恢復)에 미치는 영향(影響) (The Effect of Yook-Gun-Ja-Tang on The Side-Effect of Cyclophosphamide to The Spleen in The Rat)

  • 권오성;강윤호
    • 동국한의학연구소논문집
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    • 제2권1호
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    • pp.167-176
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    • 1993
  • The purpose of this study is to invesigate the effect of Yook-Gun-ja-Tang on the side effect of cyclophosphamide to splenical tissue in the rat. The experimental animal were divided into normal group, control group, sample group by way of method treatment of the drug. Each group was sacrificed and stained in accordance with the schedule and observed under light microscope. The results of this study were as follow : 1. After treatment of Yook-Gun-Ja-Tang, rat's weight and volume were more increased than normal group and control group. 2. The decrease of the numbers of the splenical tissue after administration of cyclophosphamide were recovered with prescription of the Yook-Gun-la-Tang ; The decreases of white pulp, red pulp, marginal zone, central artery were recovered. 3. Increased macrophages in red pulp of splenical tissue of rats with administration of cyclophosphamide were decreased after treatment of Yook-Gun-Ja-Tang. These results appeared to suggest that Yook-Gun-Ja-Tang might be effective on the: side effect of cyclophosphamide to splenical tissue of rat's and applied to the prescription for the recovery of the side effect of drug.

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