• 해양환경안전학회지
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• 제14권1호
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• pp.15-20
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• 2008

오염된 퇴적물은 연안의 생태계 파괴에 근본적인 원인이 되고 있음에 따라, 선진 외국에서는 1960년대부터 이러한 문제 해결을 위한 새로울 기술개발을 진행하여 오고 있다. 본 연구에서는 유기퇴적물 수거를 위한 시스템 설계 및 개발에 있어서 오탁확산에 의한 2차 오염을 방지하거나 최소화 할 수 있는 Pilot 규모 형태의 흡입식 펌프 준설 시스템을 설계 제작하였으며, 시스템의 성능시험을 통한 적용 가능성을 제시하였다. 시스템 최적화를 위하여 수치해석기법을 통한 퇴적물 수거 시스템의 형상에 대한 성능평가를 수행하고, 제작 시스템의 성능시험에 있어서는 시스템의 정지 상태와 이동 상태에서의 퇴적물 수거 성능에 대한 실험을 수행하였다. 본 연구를 통하여 해저 유기퇴적물의 상부만을 준설할 수 있는 시스템의 개발 가능성을 확인하였다.

• 정보화연구
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• 제9권2호
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• pp.143-154
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• 2012

본 논문에서는 천안함 폭침사건과 연평도 포격전으로 서북도서의 중요성이 부각됨에 따라 서북도서를 본토로부터 분리된 전구로 보고, 이에 대한 특징과 현실태를 고려하여 NCOE 구축방안을 제안하였다. 서북도서는 전략적 가치가 있음에도 불구하고 그동안 감시정찰체계, 지휘통제체계, 정밀타격체계의 효과적인 운용을 위한 체계적인 NCOE가 구축되지 못한 상태였다. 따라서 아키텍팅에 의한 방법을 활용하여 개선소요를 도출하였으며, 개선소요 중 전구 ISR 자산과 연계한 K-9자주포의 북한 갱도포병 타격체계 개선은 작계분석모델에 의한 시뮬레이션을 수행한 결과, 타격효과가 크게 향상된 것으로 나타났다. 이러한 NCOE 구축방안은 서북도서와 같은 분리된 전구작전을 위한 군사력 건설과 작전수행체계 구축의 표준모델로서 기여할 것으로 기대된다.

• 한국도로학회논문집
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• 제20권1호
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• pp.77-85
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• 2018

PURPOSES : The purpose of this study was to develop an urgent road-repair system and perform a field applicability test, as well as discover the optimum mix design for machine applications compared to the optimum mix design for lab applications. METHODS : According to reviews of the patent and developed equipment, self-propelled and mix-in-place equipment types are suitable for urgent pavement repair, e.g., potholes and cracks. The machine-application mix design was revised based on the optimum lab-test mix design, and the field application of a spray-injection system was performed on the job site. The mixture from the machine application and lab application was subjected to a wet-track abrasion test and a wheel-tracking test to calibrate the machine application. RESULTS and CONCLUSIONS : This study showed that the binder content could differ for the lab application and the machine application in the same setting. Based on the wet-track abrasion test result, the binder contents of the machine application exceeded the binder contents of the lab application by 1-1.5% on the same setting value. Moreover, the maximum dynamic stability value for the machine application showed 1% lower binder contents than the maximum lab-application value. Collectively, the results of the two different tests showed that the different sizes and operating methods of the machine and lab applications could affect the mix designs. Further studies will be performed to verify the bonding strength and monitor the field application.

• 한국농업기계학회:학술대회논문집
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• 한국농업기계학회 1996년도 International Conference on Agricultural Machinery Engineering Proceedings
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• pp.967-976
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• 1996

Straw and other fibrous by-products are inevitably produced during cereal production and have traditionally been used for many purposes including feeding animals . The potential of these by -products as a feed resource for ruminants is being increasingly appreciated (FAO , 1977). In the future, the amount of cereals fed to farm animals will have to be reduced and livestock will have to rely more on by-products such as straw. The method of animal production can be classified by the major portion of feed. One is animal forage and the other is grains. In Korea , livestock farmers normally depend more than 70% upon grains for the feed stuff. The livestock production system causes the unbalance of nutrition, and results in low productivity of animal farming. In many livestock farms in Korea the rice straw is using as a major forage and the amount of rice straw fed takes 46% of total amount of required forages. Especially the rice straw is mainly using during spring, fall and winte season. However, there are still lots of problems to solved such as harvesting cost, transportation between rice farm ad livestock farm, and quality loss during drying and storage . Therefore the mechanization of straw harvesting is urgently needed to use the renewable agricultural by-products and to overcome the shortage of animal forage. The objective of this research is to develope a straw harvester with new concept which can solve the problems of the quality loss and the labor cost during drying in a field, collecting , and storage. The developed straw harvester is self-propelled machine rebuilt by rice combine and equipped with the pick-up device, the macerater and the mat-forming device.

• 한국시뮬레이션학회논문지
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• 제20권4호
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• pp.1-11
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• 2011

어뢰 개발 단계에서는 어뢰의 성능 예측과 운용 방법 습득을 위해 효과도 분석이 실시되고 있다. 이 때 신뢰성 있는 데이터를 획득하기 위해서는 전술 상황을 실제에 가깝게 모델링한 시뮬레이션 프로그램이 필요하다. 경어뢰의 경우 잠수함을 주요표적으로 삼고 있는데, 잠수함의 어뢰 대항 수단인 회피 기동이나 어뢰음향대항체계(TACM)를 상세히 모델링해야 신뢰성 있는 효과도 분석 결과를 획득할 수 있다. 본 논문에서는 잠수함의 운동 특성을 반영하여 회피기동을 모델링하였으며 부유식 기만기, 자항식 기만기, 재머(jammer) 등 다양한 음향대항체계를 고려하여 잠수함 표적을 모델링하였다. 그리고 이러한 모델링을 통해 개발한 시뮬레이션 프로그램을 이용하여 경어뢰의 효과도를 측정하고 분석하였다.

• Journal of Biosystems Engineering
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• 제41권4호
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• pp.294-303
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• 2016

Purpose: This study aimed to evaluate the profitability of four selective mechanization systems in rice cultivation. Methods: Field experiments were conducted in the farmers' field during the wet season (June to November) of 2015 in Bangladesh. Mechanization systems were applied to evaluate four different selective levels (treatment) in eleven consequent operations. Seedlings were raised in a traditional seedbed and trays for manual and mechanical transplanting, respectively. Land preparation, irrigation, fertilizer, pesticide, carrying, and threshing and cleaning operations were performed using the same method in all the experimental plots. The mechanical options in the transplanting, weeding, and harvesting operations were changed. The mechanization systems were $S_1$ = hand transplanting + hand weeding + harvesting by sickle, $S_2$ = mechanical transplanting + Bangladesh Rice Research Institute (BRRI) weeder + reaper, $S_3$ = mechanical transplanting + BRRI power weeder + reaper, and $S_4$ = mechanical transplanting + herbicide + reaper. This experiment was performed in a randomized complete block design with four replications. Power tiller, rice transplanter, BRRI weeder, BRRI power weeder, self-propelled reaper, BRRI open drum thresher, and BRRI winnower were used in the respective operations. Accordingly, the techno-economic performances of the different technologies were calculated and compared with those of the traditional system. Results: The mechanically transplanted plot produced 6-10% more yield than the hand transplanted plot because of the use of tender-aged seedlings. Mechanical transplanting reduced 61% labor and 18% cost compared to manual transplanting. The BRRI weeder, BRRI power weeder, and herbicide application reduced 74, 91, and 98% labor, respectively. The latter also saved 72, 63, and 82% cost, respectively, compared to hand weeding. Herbicide application reduced the substantial amount of labor and cost in the weeding operation. Mechanical harvesting also saved 96% labor and 72% cost compared to the traditional method of harvesting using sickle. Selective mechanization saved 15-17% input cost compared to the traditional method of rice cultivation. Conclusions: Mechanical transplanting with the safe use of herbicide and harvesting by reaper is the most cost- and labor-saving operation. The method might be the recommended set of selective mechanization for enhancing productivity.

• 한국산학기술학회논문지
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• 제16권9호
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• pp.5914-5923
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• 2015

최근 들어 군수품에 대한 품질문제가 다양한 형태로 발생하면서, 품질보증업무를 수행하는 국방기술품질원의 위험관리기반 프레임웍에 대한 변화의 필요성이 제기되고 있다. 본 논문에서는 먼저 위험관리관련 수행된 기존 연구들을 검토한 후, 현재 국방기술품질원과 위험관리기반 체제를 채택하고 있는 국내 외 기관 두 곳의 업무규정을 비교 분석하여 문제점 식별 및 개선점을 도출 하였다. 본 연구에서 제안하는 새로운 위험관리 프레임웍은 PDCA 프레임웍을 기반으로 눈에 보이는 관리를 위해 Fishbone차트의 활용을 제안하였다. 또한 마인드맵 소프트웨어의 활용을 통해 군수품 위험관리 사례의 구현으로 실제업무의 적용가능성을 검토해 보았다.

• Geomechanics and Engineering
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• 제27권6호
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• pp.537-550
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• 2021

There are various technical problems need to be solved in the construction process of pre-setting an isolation wall into a double lane in the outburst prone mine. This study presents a methodology that pre-setting an isolation wall into a double lane without a coal pillar. This requires the excavation of two small section roadways to dig a wide section roadway, followed by construction of the separation wall. During this process the connecting lane is reserved. In order to ensure the stability of the separation wall, the required bearing capacity of the isolation wall is 4.66 MN/m and the deformation of the isolation wall is approximately 25 cm. To reduce the difficulty of implementing support the roadway is driven by 5 m/d. After the construction of the separation wall, the left side coal wall is brushed 1.5 m to make the width of the gas roadway reach 2.5 m and the roadway support utilizes anchor rod, ladder beam, anchor cable beam and net configuration. During construction, the concrete pump and removable self-propelled hydraulic wall mold are used to pump and pour the concrete of the isolation wall. In the process of mining, the stress distribution of coal body and isolation wall is detected and measured on site. The results demonstrate that the deformation of the surrounding rock of roadway and separation of roof in the roadway is small. The stress of the bolt and anchor cable is within equipment tolerance validating their selection. The roadway is well supported and the intended goal is achieved. The methodology can be used for reference for similar mine gas control.

• 품질경영학회지
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• 제51권4호
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• pp.619-632
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• 2023

Purpose: The main function of INS (Inertial Navigation System) is to measure the position of an armed vehicle and its performance is confirmed through the positioning accuracy test of Korean Defense Standards (KDS). The current standards, however, do not provide clear test methods and the conditions for performing positioning accuracy tests. Accordingly, the purpose of this study is to develop a new method for positioning accuracy test which would be effective. Methods: In this study, a new INS positioning accuracy test method is suggested based on the analysis of test data collected through a statistical experiment known as central composite design. For the positioning accuracy experiment of K105A1, a self-propelled artillery, two factors of driving velocity and driving distance are considered. Results: Based on the analysis of experimental data, a regression model for the positioning error is fitted and the positioning accuracy test of INS is so developed to maximize the positioning error. The standard proximity rate is used as an additional test criterion to evaluate the performance level of INS. Conclusion: The proposed new positioning accuracy test for INS has the advantage of finding the nonconforming items effectively. It is also expected to be utilized for the other similar INS positioning accuracy tests.

• 한국노년학
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• 제31권1호
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• pp.157-170
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• 2011

본 연구는 도심의 종묘공원에 모인 노년 남성들이 형성하는 몸짓문화가 어떤 점에서 그들의 정체성을 표현하고 확인하는 일종의 '정체성의 몸짓'의 의미를 지니는지를 밝히고자 한다. 또한, 이러한 시도를 통해 얻은 결과를 기초로 노년을 대상으로 하는 질적 연구에 있어 몸의 해석학의 필요성을 제안한다. 자료 수집은 종묘공원과 그 인근지역에서 이루어졌으며, 민족지적 현장 연구에 적합한 지속적 자료수집과 분석을 통하여 정리되었다. 연령주의 사회에서 노년의 정체성 유지는 점점 힘들어진다. 종묘공원을 찾는 노인들의 경우에는 공원 자체가 언론에 의해 "해방구"라는 사회적 낙인을 감당해야 하는 장소가 되었고, 또 이들 노년들의 상대적으로 낮은 신분적 배경으로 인해 문화적 성원권과 정체성의 위협이 심화된다. '성역화'란 이름으로 정부가 종묘공원을 정비하기 이전에 만개했던 음주가무를 중심으로 하는 종묘공원 노년 남성들의 몸짓문화는 이런 상황에서 자신들의 지속적 자아감을 확인할 수 있게 해 주는 매개이며, 노년의 정체감을 위협하는 연령주의에 대한 방어막의 의미를 지닌다. 노년 연구에 있어 언어를 통해 형상화되는 의미에 대한 연구와 함께 몸과 몸짓의 의미해석을 위한 '몸의 해석학'적 접근이 요구된다.