• 대한방사선기술학회지:방사선기술과학
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• 제22권1호
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• pp.21-26
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• 1999

To make a comparative analysis for clinical application of total hip replacement arthroplasty(THRA) using fluoroscopy, we have performed total hip replacement arthroplasty making 30 patients an object with general radiography and fluoroscopy respectively. The results are as follows : 1) Reexamination rate was 80% of patients and mean 3.9 sheets in the general radiography, where as it was 46.7% and 0.37 sheets in the fluoroscopy(p<0.01) 2) Add examination was 2 cases in the general radiography, but fluoroscopy was no add examination. 3) The total film sheet used was mean 10.16 in the general radiography and 6.73 in the fluoroscopy. 4) In the cause of reexmination and add examination, inaccurate position of patient accounted for 72.6% in the general radiography and poor exposure condition accounted for 45.5% in the fluoroscopy. Total hip replacement arthroplasty using the fluoroscopy decreased reexamination and add examination rate, for these reasons, this method was effective abatement of pain, exposured radiation dose, and examination time and so on.

• 한국세라믹학회지
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• 제44권1호
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• pp.1-5
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• 2007

Fining and homogenization of melts during batch melting is closely related to the redox reaction of polyvalent element M (M: Sb, As etc), $M^{(x+n)+}+n/2O^{2-}{\rightarrow}M^{x+}+n/4O_2$. In this study, square wave voltammetry (SWV) measurements were performed to examine the redox behavior of an antimony ion in cathode ray tube (CRT) glass melts. According to results, well-separated two peaks are shown at low temperature while only one peak is shown at high temperature in voltammograms, which reveals that redox reaction of antimony consist of two steps: $Sb^{5+}/Sb^{3+}\;and\;Sb^{3+}/Sb^0$, depending on the temperature. Based on the peak potential shown in the voltammogram, the thermodynamic data and the redox ratio for two redox couple were determined.

• 한국군사과학기술학회지
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• 제12권2호
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• pp.146-151
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• 2009

It is known that muzzle flash can be generated by the reaction between the oxygen in the air and unburned gunpowder contained in the propellant gas if a barrel is not long enough to burn gunpowder fully inside of the barrel. A hugh muzzle flash, which is a characteristic of small arms with short barrel length, disturbs a shooter in aiming at the target at night by making the shooter blind for a while and endangers the shooter's life by revealing firing position to enemies. In addition, the heat of muzzle flash can deteriorate the performance of thermal sights, which are attached to small arms for effective night combat. In this paper, flash suppressors of different shapes were designed for a newly developed 5.56mm caliber rifle with short barrel length and the performance of each flash suppressor to reduce the muzzle flash was compared by on-site test firing. Through the test firing, a highly efficient design of flash suppressor for reducing the muzzle flash was identified. The result of the paper can be referred when designing flash suppressors for small arms with short barrel length.

• 한국군사과학기술학회지
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• 제14권3호
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• pp.380-387
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• 2011

In this paper, we considered the authoritative representation of Command and Fire Control System(CFCS) for the surface ship that was the engineering level model to develop system specifications and to analyze operational concepts on the concept design phase and to analyze military requirements, effectiveness and performance for the system. The engineering level model of CFCS can be used in simulation independently of the surface ship's type, and also it takes reuse, interoperability, and extension into consideration. The detailed sub-models, internal and external data interface, data flow among each sub-model, sensor and weapon models about the engineering level model of CFCS was defined. It was verified via engineering level simulations according to the V&V process.

• 한국군사과학기술학회지
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• 제13권3호
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• pp.343-348
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• 2010

Recently, unmanned electric vehicles are increasingly interested among all of the world since they can provide low exhaust gas, high efficiency and high mobility. To exploit their silent maneuver and high mobility, unmanned electric vehicles have been developed since early 1980's for military. However, it is not easy to design and control a power system satisfying operating duration and mobility performance requirements based on various mission profiles for military use under the conditions of limited space and weight. Moreover it is also necessary to prevent over-charge, over-discharge and voltage unbalance between cells of battery to secure high voltage battery which is serially connected with muti-cells. In this paper, we presents power control and optimal management method for the dog-horse robot which adopts a electric power system and suggests a guide-line to manage and control to secure high voltage battery.

• 한국군사과학기술학회지
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• 제16권4호
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• pp.456-464
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• 2013

Passive sonar in submarine can detect the target in long range and can attack using it. There are many noises which can be received at passive sonar of submarine. When noise received in the sonar it make diverse interference pattern depend on the ocean ambient and movement scenario. Interference pattern can be explained by theory of waveguide invariant. In this paper, analyze the interference pattern according to the relative motions of surface ship and submarine. And analyze the occurrence reason of 2 kinds of interference patterns those are usually display on the submarine console. The results show that if relative speed of submarine and target increase then gradient of interference pattern will increase. And closest point approach of submarine and target decrease then gradient of interference pattern will increase. Bathtube pattern usually appear when target pass though close to submarine and Pinetree pattern appear target pass though above of submarine.

• 한국추진공학회:학술대회논문집
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• 한국추진공학회 2011년도 제36회 춘계학술대회논문집
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• pp.318-325
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• 2011

이중연소 램제트 엔진의 작동특성 및 주요 설계인자를 파악하기 위하여 공기역학 및 열역학적 이론을 기반으로 한 기본적인 성능해석 모델을 수립하였다. 이중연소 램제트 엔진의 예비 성능해석을 수행하였고, 그 결과는 흡입구, 가스발생기, 초음속 연소기 사이의 상세한 관계를 설명하고 있다. 본 연구에서 제시된 방법은 가스발생기와 초음속 연소기의 기하학적 형상을 정량적으로 결정하고, 엔진 각 구성품의 성능에 대한 영향을 평가하기 위한 도구를 제공한다. 또한 예비 성능해석을 통해 이중 연소 램제트 엔진의 기본 형상 설계 결과를 도출하였다.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 2001년도 ICCAS
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• pp.114.3-114
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• 2001

The pure navigation system using Inertial Navigation Unit(INU) which has very accurate short term stabilities but not long term gives rise to position errors propotional to time. On the contrary, Global Positioning System(GPS) which is bounded its errors to some fixed ranges shows higher accuracy in the long term, and lower accuracy in the short term than that of INS. Recently the integration of these two systems is one of the main topic in the field of navigation system. In this thesis, the implementation of kalman filter on the real time navigation computer and step jump error compensation method is suggested.

• 한국군사과학기술학회지
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• 제14권4호
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• pp.700-709
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• 2011

In this paper, we propose a novel method which can detect ordnance firing events in IR images. The proposed algorithm is comprised of effective target detection and robust clutter rejection methods based on the temporalspatial cooperative filter. And additional clutter reduction is performed based on the proposed two features, NTFF (Number of Temporal Filter Frames) and SNS(Size-Normalized Signal). Experimental results show the effectiveness and feasibilities of our proposed algorithm.

• 한국군사과학기술학회지
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• 제13권5호
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• pp.785-792
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• 2010

This paper on the Research of Naval Electronic Warfare System HILS(Hardware In the Loop System) describes the EW engagement HILS construction method for evaluation of the operational concept analysis on active RF Decoy in staying in the air and the deceit ability to anti-ship missile seeker. We obtain the EW M&S technology of EW engagement HILS and EW efficiency analysis from this project. This Naval Electronic Warfare System HILS technology will support Active Decoy Development Project and any other HILS of EW weapon in KOREA ARMY/NAVY/AIR FORCE.