• 한국군사과학기술학회지
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• 제7권2호
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• pp.5-12
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• 2004

The erosion wear of gun barrel occurs due to heat and chemical reactions. The high pressure and temperature in chamber increase the erosion wear. It is known that the metal phase transfer is the primary wear factor in a gun barrel under high temperature. In this paper, the tool of wear prediction in high pressure gun tube has been developed. The program developed has three modules such as DIRECT(interior ballistics analysis module), INVERSE(gun design module), and WEAR(wear prediction module). The prediction of wear was compared with the experimental data which was collected in the field unit. The prediction results shows good trend with the collected data.

• 전기학회논문지P
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• 제59권4호
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• pp.440-443
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• 2010

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.

• Parasites, Hosts and Diseases
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• 제47권3호
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• pp.307-310
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• 2009

Fishborne trematode (FBT) metacercariae were investigated in yellowfin goby, Acanthogobius flavimanus, collected from Shinan-gun and Muan-gun, Jeollanam-do (province), Korea. All collected fishes were examined using the artificial digestion method. In all of 15 gobies from Aphae-myeon in Shinan-gun, metacercariae of Stictodora spp. (334 metacercariae/fish), Heterophyes nocens (153/fish), and Heterophyopsis continua (20/fish) were detected. In 2 of 14 gobies from Jido-myeon in Shinan-gun, 8 Echinostoma hortense metacercariae in total were detected. In 15 gobies from Haeje-myeon in Muan-gun, the metacercariae of H. continua were found in 100%, Stictodora spp. in 86.7%, and H. nocens in 6.7% of fish examined. The average numbers of metacercariae per infected fish were 23.3 (H. continua), 416.0 (Stictodora spp.), and 2.0(H. nocens), respectively. The metacercariae of E. hortense found in gobies were elliptical, with 150 ${\times}$ 138 ${\mu}m$, in average size, and had 27 collar spines on the head crown. The above results suggest that yellowfin gobies from 2 localities may be the potential infection sources of FBT. Moreover, it is proved for the first time that the yellowfin goby, A. flavimanus, acts as a second intermediate host for E. hortense.

• 한국항공우주학회지
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• 제31권7호
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• pp.94-99
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• 2003

액체로켓엔진의 연소 안정성 평가를 위한 압력 교란 장치인 펄스건은 내재된 화약 폭발시 충격파를 유도관을 통해 엔진 연소기 내부로 전달 발생시키게 된다. 본 연구에서는 펄스건 특성에 영향을 주는 여러 가지 인자 중 화약 충진량에 의한 충격파 특성 파악을 위해 KSR-III 주 엔진과 같은 직경 크기를 갖는 모사 챕버를 이용하였다. 펄스건 출구에서 발생하는 충격파는 축대칭의 균일한 형상의 세기를 지니고 있으며 전체적인 세기 분포는 챔버 내의 압력에 따라 변화함을 확인하였다. 펄스건의 충격파는 상온 상태 조건에서 챔버내의 공명 주파수를 가진하는 것으로 보아 실제 연소장에서도 충분한 압력 교란을 제공할 수 있을 것으로 보인다. 가장 중요한 점은 펄스건에 의해 발생하는 초기 압력 최대 값이 화약 충진량의 크기에 비례하는 경향을 보인다는 것이다.

• 농촌계획
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• 제29권3호
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• pp.79-89
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• 2023

As the demand for environmental-friendly agricultural products continues to rise due to increased concerns regarding food safety and ecosystem conservation, it is becoming important to identify regions and spatial locations where environmental-friendly should be intensively established for production integration. This study aims to analyze the spatial distribution of environmental-friendly certified farms in Jeollanam-do, South Korea. Spatial statistical analysis based on Local Moran's I and Getis-Ord Gi^* were used to identify spatial cluster characteristics and landscape indices were utilized to analyze spatial patterns of environmental-friendly certified farms. The results indicated that Haenam-gun, Gangjin-gun, Muan-gun, and Jindo-gun were identified as hotspots, while Muan-gun, Goheung-gun, and Jindo-gun exhibited high connectivity. This suggests that environmental-friendly certified farms in Muan-gun and Jindo-gun were clustered and closely connected to one another. Based on the results of the spatial distribution of environmental-friendly certified farms, areas belonging to the hotspot and with high connectivity should be managed as clustered districts to secure the foundation and system of environmental-friendly certified farms. Areas that belong to cold spots and have low connectivity should be preceded by measures to promote conversion to environmental-friendly agriculture. In addition, it is necessary to make it possible to create a large-scale cluster district through a long-term spatial planning strategy to expand the environmental-friendly certified farms. The findings of this study can provide quantitative data on policies and discussions for developing a model for rural spatial planning.

• 한국농촌간호학회지
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• 제7권1호
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• pp.5-17
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• 2012

Purpose: The objectives of this study were to investigate the prevalence of the metabolic syndrome (MetS) and to identify associated factors with MetS among rural residents. Methods: Data were collected from 1,196 subjects over aged 30 years by a self-administered questionnaire, physical measurement, and blood test in a rural area. The prevalence of MetS was determined by the criteria of the American Heart Association/National Heart, Lung, and Blood Institute (AHA/NHLBI) and 2005 the Korean society for the study of obesity. Results: The prevalence of MetS was 40.5% for men, 49.2% for women. The prevalence of risk factors of MetS was 57.4% for elevated blood pressure, 49.0% for low HDL-cholesterol, and 48.6% for abdominal obesity. Unemployment and higher Body mass index (BMI) were associated factors for MetS regardless of gender. And higher age and physical inactivity in women only increased the odds of the MetS. Especially, BMI was a strong risk factor of MetS in both men and women. Conclusion: The prevalence of metabolic syndrome was higher in a rural area. Therefore, health care providers should develop lifestyle modification program to increase physical activity level and to prevent the obesity among rural residents in order to decrease the prevalence of MetS.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 1988년도 한국자동제어학술회의논문집(국내학술편); 한국전력공사연수원, 서울; 21-22 Oct. 1988
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• pp.654-657
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• 1988

In the existing GFCS (Gun Fire Control Systems) there is sometimes the problem of the miss distance which is between a target and the projectiles from gun and cannot be neglected. This errors are difficult to reduce either in the gun design phase or by precalibration exercise. In this paper the CLSA (Closed Loop Spotting Algorithm) which is applied to improve the performance of the GFCS is porposed and analysed. The results simulated by Monte Carlo technics show us better performance than the existing GFCS.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 1990년도 한국자동제어학술회의논문집(국내학술편); KOEX, Seoul; 26-27 Oct. 1990
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• pp.794-798
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• 1990

To improve gun hit probability and to correct miss distance between target and bullet. It assumes that a radar tracks both the targets and bullets fired by a gun system. This papers describes an adaptive algorithm developed for processing the large number of radar measurements. The gun-order computation is enhanced by feedback from the ballistic estimator.

• 한국군사과학기술학회지
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• 제3권2호
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• pp.7-14
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• 2000

In this paper, the possibility of plastic deformation of rifle and gun barrels is studied through the numerical methods. When a rifle or tank gun is fired, the expansive deformation of the barrel can occur by the explosive pressure and the thermal effect. Using the ABAQUS program, the stresses and displacements are computed for the elastic and elastic-plastic material property, and the possibility of plasticity deformation is investigated. In conclusion, rifle and tank gun barrel the plastic deformation occurred in some parts of the barrel

• 대한전기학회:학술대회논문집
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• 대한전기학회 2006년도 제37회 하계학술대회 논문집 C
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• pp.1552-1553
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• 2006

A thermionic gun of injector linac for pohang accelerator laboratory is required to generate beam pulse width less than 1 nsec. The gun uses cathode-grid assembly(EIMAC Y824) and operates up to 80 kV anode voltage. In order research characteristics of the electron gun, emission current from gun wear measured by the wall current monitor. In this paper the pulser system and characteristics of the emission current in region from 30 mA to 15 A are described.