• 한국군사과학기술학회지
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• 제22권1호
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• pp.27-34
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• 2019

This paper presents a chamber pressure model development of K2 rifle by applying Gaussian mixture model. In order to materialize a real recoil force of a virtual reality shooting rifle in military combat training, the chamber pressure which is one of major components of the recoil force needs to be investigated and modeled. Over 200,000 data of the chamber pressure were collected by implementing live fire experiments with both K100 and M193 of 5.56 mm bullets. Gaussian mixture method was also applied to create a mathematical model that satisfies nonlinear, asymmetry, and deviations of the chamber pressure which is caused by irregular characteristics of propellant combustion. In addition, Polynomial and Fourier Regression were used for comparison of results, and the sum of squared errors, the coefficient of determination and root-mean-square errors were analyzed for performance measurement.

• 한국환경교육학회:학술대회논문집
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• 한국환경교육학회 2003년도 전반기 정기 학술발표대회 발표논문집
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• pp.50-56
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• 2003

＃1 The Education from our Environment, The urgent subject for survival and prosperity in the future. - Around Yamaguchi in japan. - ＃2 Days of tour : January, 15, 2003 - January, 28, 2003 ＊ Comprehensive classes involved in ecosystems; Ryojo Elementary school, Guina Elementary school, Dabusei Junior High School, Ube Technical High School, Yashiro Elementary School, Toyota Nishi Junior High School, Seii Elementary School, Yamaguchi Prefectural School for the Mentally Impaired, Yamaguchi Institute for Educational Research and In-service Training, Kirara Beach Nature Watching Park ＃3 Characteristics of Yamaguchi Prefectural Environmental Education - Constant effort by concerned authorities and dedicated teachers - Cooperation of schools with community - Application of the comprehensive classes - Student-centered education through experiences - Acquirement of basic knowledge on environment in their daily lives - The harmony with the ability to survive' ＃4 Characteristics of the environmental education in each school $\square$ Ryojo Elementary School \longrightarrow Breeding the fireflies' larvae and releasing them into nature $\square$ Kuina Elementary School \longrightarrow Keeping the rivers clean $\square$ Yashiro Elementary School \longrightarrow Learning through exploring ‘Akiyoshido Cave’ $\square$ Seii Elementary School \longrightarrow Tree-planting campaign continued for 30 years $\square$ Tabuse Junior High School \longrightarrow Making their village good to live in $\square$ Toyota-Nishi Junior High School \longrightarrow Learning through working on the farm and in the forests $\square$ Ube Technical High School \longrightarrow Purifying the pond by the ‘biotope’ ＃5 Focus on Yashiro Elementary School \longrightarrow Children Guide Activity (25 hours annually) * To love their native place and tourists' attraction, Akiyoshidal * To introduce a variety of local events; - To make a fire in the mountains - To explore the cave - To hold a festival for tourists - To have a family-jointed bike riding ＃6 $\square$ conclusion - Gradual extension of environmental education * individuals \longrightarrow school \longrightarrow community - Finding the environmental problems around themselves and relating them with features of their community < Tips for the environmental education in the future > - Need for encouragement of more lively discussion in class - Expansive application of comprehensive classes to various areas

• 한국산학기술학회논문지
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• 제17권6호
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• pp.700-707
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• 2016

최근 군에서 사격 훈련 중 1990년에 제조된 40mm 저속유탄(K200)은 탄착불발에 의한 탄약 악작용이 발생하였다. 악작용 내용은 총 72발의 사격 중 11발의 불발탄이 발생되어 불발율은 15% 정도였다. 탄약은 장기 저장 후 사용하는 품질특성을 가지고 있으므로 장기 저장시에도 성능 및 안전성 등의 확보가 필수적이다. 따라서 본 연구에서는 40mm 저속유탄용 신관의 품질개선을 통해 불발율을 최소화하고자 하였다. 첫 번째로 기폭관 성능시험, 발사시험 등을 수행한 결과 불발의 원인을 신관 화공품인 기폭관의 경시변화에 의한 성능저하로 판단하였다. 두 번째로 불발율을 최소화하기 위해 기폭관의 화약량을 증가시키고 화약량 증가에 따른 부품의 치수를 변경하는 등 40mm 저속유탄 신관의 품질개선을 추진하였다. 마지막으로 품질 개선 전 후 기존품과 개선품의 가속노화시험을 통해 저장수명을 예측해 본 결과 기존품은 6.5년, 개선품은 45.5년으로 개선되어 신관의 수명이 약 7배 향상된 결과를 도출하였다. 이에 품질 개선된 40mm 저속유탄 신관은 장기 저장시 불발율이 감소되어 40mm 저속유탄의 안전성, 신뢰성, 성능 향상에 기여할 것으로 판단된다.