• Journal of Biosystems Engineering
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• 제34권6호
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• pp.397-403
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• 2009

This study was carried out to investigate the present status of subsoil compaction, and subsoil compaction management in orchard as a basic study for developing a self-propelled explosive subsoiler. Subsoil compaction was evaluated using the soil penetration resistance. Soil cone index was measured using the DIK 5520 type cone penetrometer in several fruit farms such as apple, pear, peach and grapes during growing seasons of these fruit in Jecheon, Gamgok, Choongju, Cheonan and Hwasung areas. Most of the subsoil managing machinery were either explosive type or digging type attached to the tractor or power tiller and turning radius of this machine was more than 3-5 m. Many of the farmers wanted to use the subsoiler which can put lime into soil and rupture soil at the same time. For most of the orchard fields, soil penetration resistance in vehicle traffic area was increased quickly and reached about 1.0 MPa in 5 cm soil depth. As the soil depth increased to 15-20 cm, cone penetration resistance reached about 2.0-2.5 MPa which restricted root growth seriously. Thus it was concluded that one of the main reason for increasing the soil compaction in orchard fields is agricultural vehicle traffic. In the vicinity of fruit trees, compaction is not so serious compared to that of the vehicle traffic area, but as the soil depth increased to 20-25 cm, in most of the orchard fields soil penetration resistance reached about 2.0-2.5 MPa which is the root growth-limiting value. Considering the rooting depth of fruit trees which ranged 30-60 cm for apple, pear and peach, and 20-30 cm for grape, it is necessary to loosen the subosoil and improve the subsoil conditions using subsoiler.

• Ocean and Polar Research
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• 제32권4호
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• pp.463-473
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• 2010

Inshore tests were performed in order to verify the design concept of deep sea manganese nodule miner at a site near Hupo at East Sea of Korea in June of 2009. Total mining tests of the test miner, named 'Minero$^{(R)}$', together with flexible hose, lifting pump and lifting hose were accomplished. In this study, the performances of three subsystems of testminer (vehicle, pick-up device, and launch-and-recovery device) were analyzed for feasibility assessment of self-propelled remotely controlled miner, and also to compile basic data for designing a pilotminer. Performances of the test miner were defined based on the Functional Requirements of Axiomatic Design. The inshore tests revealed that the test miner generally satisfies the functional performances. Feasibility assessment and reflection on results are discussed within.

• 대한기계학회논문집A
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• 제40권2호
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• pp.229-236
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• 2016

본 연구에서는 자주박격포의 다물체동역학 모델을 만든 뒤, 포탄의 탄도학을 고려하여 시뮬레이션 하였다. 자주박격포 모델은 박격포 모델 및 차량 모델로 구성하였으며, 상용 다물체 해석 프로그램인 RecurDyn 을 사용하였다. 차량 모델은 6 자유도 강체플랫폼으로 모델링 하였으며, 박격포 발사 직후의 움직임에는 강내탄도학을 적용하였다. 강내탄도학 해석의 결과를 바탕으로, 포신을 떠난 후의 강외탄도 해석을 수행하였다. 몬테카를로 기법을 활용한 반복 해석으로 발사각과 차량 동특성에 의한 변동이 고려된 탄착점의 분산도를 구하여 사격정확도를 제시하였다.

• 한국시뮬레이션학회논문지
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• 제20권3호
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• pp.11-18
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• 2011

한국 육군은 K-9자주포용 탄약보급 장비로 K-10 탄약운반 장갑차를 운용하고 있으며, K-55 자주포용 탄약운반 장갑차의 전력화를 검토하고 있다. K-55용 탄약운반 장갑차는 현재 시제장비로 개발 된 상태로, 이 장비의 전력화 여부 및 소요대수를 결정하기 위해서는 사전에 이 장비의 운용효과를 분석할 필요가 있다. 이에 본 연구에서는 시뮬레이션을 이용하여 K-55용 탄약 운반장갑차의 운용효과를 제시하였다. 시뮬레이션 모델은 육군의 화포 편성 및 기타 포병무기체계 작전계획 분석 등을 위해 사용되는 워게임 모델인 화력운용분석모델을 활용하였다. 화력운용분석모델 모의결과에 따른 K-55 자주포용 탄약운반차의 운용효과는 탄약운반장갑차의 전력화 여부에 대한 의사 결정에 활용할 수 있을 것이라 판단된다.

• International Journal of Fuzzy Logic and Intelligent Systems
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• 제13권2호
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• pp.91-99
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• 2013

An autonomous unmanned underwater vehicle is a type of marine self-propelled robot that executes some specific mission and returns to base on completion of the task. In order to successfully execute the requested operations, the vehicle must be guided by an effective navigation algorithm that enables it to avoid obstacles and follow the best path. Architectures and principles for intelligent dynamic systems are being developed, not only in the underwater arena but also in related areas where the work does not fully justify the name. The problem of increasing the capacity of systems management is highly relevant based on the development of new methods for dynamic analysis, pattern recognition, artificial intelligence, and adaptation. Among the large variety of navigation methods that presently exist, the dynamic window approach is worth noting. It was originally presented by Fox et al. and has been implemented in indoor office robots. In this paper, the dynamic window approach is applied to the marine world by developing and extending it to manipulate vehicles in 3D marine environments. This algorithm is provided to enable efficient avoidance of obstacles and attainment of targets. Experiments conducted using the algorithm in MATLAB indicate that it is an effective obstacle avoidance approach for marine vehicles.

• 한국전자파학회논문지
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• 제28권7호
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• pp.519-527
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• 2017

자율주행자동차의 안전성에 관한 신뢰의 문제는 관련 산업의 수요 창출과 관련하여 매우 중요한 문제이다. 신뢰 확보를 위해서는 우선 자율주행자동차의 사고발생시 법적 책임문제의 연구가 선행되어야 한다. 사고 발생 시의 문제로 가장 시급한 민 형사상의 책임귀속 문제에 있어서 민사상으로는 "제조물책임법" 하에서 자동차 제작자에게 책임을 물을 수 있을 것이나, 형사상으로는 행위자 책임을 근본으로 하는 현행 법체계에서는 사람에게 책임을 묻기가 어려운 문제이다. 이러한 문제들을 해결하기 위한 "자율주행자동차 특별법"의 제정을 제안하는 바이며, 또한 (완전) 자율주행자동차가 운행하는데 필요한 각종 시스템 또는 인프라의 구축과 그 운용에 따른 국가 또는 공적인 "인증" 등 제도의 구축도 필요하다. 드론의 경우, 그 비행의 특성상 영상 촬영장치를 장착하고 비행할 때, 개인의 정보 및 위치 정보까지 수집되는 법적인 문제점을 내포하고 있다.

• 한국기계가공학회지
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• 제17권2호
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• pp.77-82
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• 2018

Track shoes improve the off-road driving ability of tanks. The strength of the track shoe body directly affects the driving ability of tanks, self-propelled artillery, and armored vehicles. In this study, the design technique for track shoe body was investigated. To select the optimal design of track shoe body, three track shoe body models were suggested and compared. Tensile strength was calculated using computer-aided engineering (CAE) analysis. Compressive tests were conducted using the original tank sprocket because sprocket compression is critical to the lifespan of the track shoe body. As a result, one track shoe body design was selected and the process of track shoe body design was described.

• 한국해양공학회지
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• 제26권1호
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• pp.41-46
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• 2012

A deep-sea manganese nodule miner consists of 4 parts: the pickup device, crusher, disposal device, and tracked vehicle. The tracked vehicle is an essential component to keep the self-propelled miner moving across deep-sea soil. The performances of the tracked vehicle are influenced by noise factors: the shear strength of the seafloor, bottom current, seafloor slope, track speed, reaction forces of flexible hose, etc. It is necessary to adopt a robust design method that improves the performances and minimizes the variation caused by noise factors. Taguchi's method, the most widely known robust design method, searches for the robust optimum using an orthogonal array composed of the product of the inner array and outer array. In this paper, we propose a new screening technique to reduce the number of input factors and apply the MRSN (Multi-Response Signal to Noise) ratio to convert multiple performances into single one in order to overcome the difficulties and limitations of using Taguchi's method in a case with many input factors and multiple performances. A test miner was already designed and tested. It has about 1/10 the capacity of a commercial one and was successfully operated at an in-shore area. Taguchi's robust design was applied to the tracked vehicle of the test miner, and design improvements were implemented for the vehicle.

• 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.

• 한국국방경영분석학회지
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• 제34권2호
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• pp.143-162
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• 2008

이 연구는 현재 개발이 진행 중인 장갑차량 상부 공격용 지능형 탄약을 포함한 155mm 포병 탄약의 전시소요량을 산정하는 방법론을 정립하려는 것이다. 종래의 워게임 시뮬레이션에 의한 방법에서는 장갑표적 공격용 무기체계별 기대점유비율이 지상군 및 공군간에 과도하게 차이가 발생하고 있다. 또한 상향식 소요산정방법은 최소소요량에 비하여 너무나 과도하게 산출하는 경향이 있으므로 이러한 점들을 보완하기 위하여 표적 수량에 따른 무기체계별 할당에 의한 하향식 모형을 구성한 것이다. 이모형이 워게임에 의한 상향식 소요산정보다는 더 믿을 만한 결과를 산출한다.