• 대한기계학회논문집
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• 제3권4호
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• pp.173-180
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• 1979

Temperature distriburion in a hollow chlinder has been analyzed mathematically. Unsteady condition considered assumed a constant heat flux input from the inside. The results are compared with experimental results of surface temperature rise of a gun barrel during continuous firing. Their agreements are acceptable. Effects of various dimensionless parameters on the surface temperature rise are discussed. For small Biot numbers, the external survface temperature approaches more rapidly to the steady temperature. Temperature difference between internal and external surfaces becomes greater for small Biot number. Steady solution assumed that the gas temperature inside the cylinder varies periodically. Relative amplitude and phase angles between the gas temperature and the internal or external surface temperature are obtained. Phase angles become smaller for large radiancy of gas temperature variation, small external Biot number, or large internal biot number. Relative amplitudes become samller as radiancy of gas temperature variation and internal Biot number become smaller. or external Biot number becomes larger. The solution obtained in this paper can be applied to gun barrels, heat pipes used in heat excangers, and reciprocation engines.

• Neonatal Medicine
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• 제17권2호
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• pp.161-167
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• 2010

Acute kidney injury (AKI), formerly referred to as acute renal failure (ARF) is defined as the sudden impairment of kidney function (estimated from the glomerular filtration rate [GFR]) that results in the lack of excretion of waste products. More than 30 definitions of AKI exist in the literature, most of which are based on serum creatinine. Lack of a uniform and multidimensional AKI definition has led to failure to recognize significant renal injury, delays in treatment, and inability to generalize single-study results. The RIFLE criteria were developed to standardize the diagnosis of ARF and in the process the term AKI has been proposed to encompass the entire spectrum of the syndrome from minor changes in renal function to requirement for renal replacement therapy. Large prospective studies are needed to test definitions and to better understand risk factors, incidence, independent outcomes, and mechanisms that lead to poor short- and long-term outcomes. Early biomarkers of AKI need to be explored in critically ill neonates.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2012년도 춘계학술대회 논문집
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• pp.588-593
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• 2012

Nowadays, various forms of electro-optical rifle scope have been developed and used in order to enhance the accuracy of small arms. However, firing shock acceleration has characteristics of pyroshock having a big acceleration value with very short duration time, which the electro-optical scopes should be designed to sustain. In this paper, the firing shock acceleration, which is transmitted to the electro-optical scope, was measured and SRS (Shock Response Spectrum) analysis was performed by using the measured firing shock acceleration. Furthermore, a shock test condition using a drop-table shock tester, which can simulate the actual firing shock acceleration, was devised. The devised shock test condition will be utilized to test the electro-optical scope itself before attaching it to the small arms.

• 한국지하수토양환경학회:학술대회논문집
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• 한국지하수토양환경학회 2003년도 추계학술발표회
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• pp.69-72
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• 2003

The purpose of this study is the development of hybrid horizontal electrokinetic(EK) remediation system on rifle range soil under unsaturated conditions. In order to remediate soil polluted by multi-species heavy metals, in pi]of scale, a series of EK remediation tests are carried out. PVC and PDB(Plastic Drain Board) electrode systems that connected with the power supply of constant voltage and vacuum pressure of 0.5kgf/$\textrm{cm}^2$ are installed, The test results showed that the pH distribution in the sample is below 8, which is maintained until the test is finished, because of the injection of flushing solution. The final concentration, which is normalized by initial concentration, is ranged about 50 to 90%.

• Journal of Advanced Marine Engineering and Technology
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• 제18권2호
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• pp.64-74
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• 1994

The gundrill is capable of machining for having large length to diameter ratio in single pass. The techniques of gundrill and gun boring began developing in the late 18th century with the need for more accurate bores in rifle, cannon, machinery part and marine part etc. The main feature of the gun drilling provides a stabilizing cutting force resultant necessary for self guidance of the drill head. A study of the accuracy and surface finish of holes produced would reveal quite useful information regarding the process. The thesis deals with the experimental results obtained during gun drilling on marine part materials for different machining conditions.

• Maxillofacial Plastic and Reconstructive Surgery
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• 제34권1호
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• pp.81-84
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• 2012

Gunshot wounds are unpredictable and require early, precise diagnosis and treatment. A penetrating gunshot wound can be fatal due to compromised airway, hypovolemic shock, lead poisoning and infection. This case report describes a 48-year-old male patient who had a suicidal gunshot wound on the right temporomandibular joint area using an air rifle. We successfully managed the patient by preoperative embolization, surgical removal of the foreign body and primary closure.

• 한국군사과학기술학회지
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• 제14권2호
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• pp.167-172
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• 2011

In this paper, a study on variation of an accuracy rate as the gradient of a rifle is shown. In the a state of hostilities, a soldier is not easy to take a shot vertically against the ground. If a soldier shoots as the pistol is inclined, how the accuracy rate is changed. While the pistol is shot, the change of ballistic curve is estimated. And we also verify the accuracy rate through the firing test. Then we compare two results and present some ideas which overcome the decrease of an accuracy rate. Hereafter, it is possible to adapt in the future soldier system and expected that the accuracy rate of the conventional gun is maintained.

• 한국국방경영분석학회지
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• 제34권2호
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• pp.1-26
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• 2008

본 연구에서는 현재 우리나라 육군이 사용하고 있는 보병화기와 포병화기(155M)의 기본 휴대량(B/L : Basic Load) 개념 정립 및 산정방법을 고찰하여 문제점을 도출하고 시뮬레이션 기법(ARENA Model)을 통해 최적의 B/L을 재산정하여 제시하였다. 본 논문을 통한 기대효과는 군수지원의 물동량 감소로 실질적인 전투 준비 태세 강화와 국방예산 절감이 예상되며, 효율적인 B/L운영 보장으로 전투 효율성을 증대시킴은 물론 궁극적으로 전장 승리를 보장하는데 기여할 것이다.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 1996년도 추계학술대회 논문집
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• pp.1039-1043
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• 1996

In the firing operation, muzzle jumping phenomenon was investigated, and a method of reducing muzzle jump was suggested. The muzzle jumping force was determined from the torque acting on the rifle due to a recoil force. For the purpose of reducing a muzzle jump, the gas flowing through the M16A1 flash suppressor was considered. A flash suppressor, improved in reducing a muzzle imp, was modeled and tested. The experiment shows that muzzle jump has quantitative relation to shape of a flash suppressor, and can be reduced by the improved modeling of a flash suppressor.

• 안보군사학연구
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• 통권5호
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• pp.281-350
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• 2007

The purpose of this study is to survey the circumstances of sniping warfare and to prove the importance of usage of snipers. The research method was referred to the history of foreign warfares and autobiographies, articles, and testimonies of snipers. Also, various news reports were also studied to collect information. The content of this study investigates the circumstances of sniping combat scenes from its first appearance in the world's major warfares to contemporary ones. Also, the research contains the history of weapons, ammunition, rifles, and the principle of rifle shooting including ballistics. We hope this study provides ROK Army and government agencies the foundation of sniping and thereby improving the effectiveness of correspondence to international conflicts and terrorism.