• 디지털산업정보학회논문지
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• 제13권2호
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• pp.13-25
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• 2017

Recently, the high performance of tactical situation display console and tactical data links are used to integrate the operational situations in accordance with information age and NCW (Network Centric Warfare). The tendency to maximize the efficiency of task execution has been developed by sharing information and the state of the battle quickly through complex and diverse information exchange. Tactical data link is a communication system that shares the platform with core components of weapons systems and battlefield situation between the command and control systems to perform a Network Centric Warfare and provides a wide range of tactical data required for decision-making and implementation.It provides the tactical information such as tactical information such as operational information, the identification of the peer, and the target location in real time or near real time in the battlefield situation, and it is operated for the exchange of mass tactical information between the intellectuals by providing common situation recognition and cooperation with joint operations. In this study, still image management, audio file management, tactical screen recording and playback using the storage and playback, NITF (National Imagery Transmission Format) message received from the displayer integrates the tactical situation in three dimensions according to multiple data link operation to suggest ways to ensure data integrity between the data link processor during the entire operation time.

• 한국군사과학기술학회지
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• 제17권2호
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• pp.235-247
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• 2014

Based on two dimensional model partition method proposed in Part 1, Part 2 provides detailed model specification and implementation. To mathematically delineate a model's behaviors and interactions among them, we extend the DEVS (Discrete Event Systems Specification) formalism and newly propose CE-DEVS (Combat Entity-DEVS) for an upper abstraction sub-model of a combat entity model. The proposed CE-DEVS additionally define two sets and one function to reflect essential semantics for the model's behaviors explicitly. These definitions enable us to understand and represent the model's behaviors easily since they eliminate differences of meaning between real-world expressions and model specifications. For model implementation, upper abstraction sub-models are implemented with DEVSim++, while the lower sub-models are realized using the C++ language. With the use of overall modeling techniques proposed in Part 1 and 2, we can conduct constructive simulation and assess factors about combat logics as well as battle field functions of the next-generation combat entity, minimizing additional modeling efforts. From the anti-torpedo warfare experiment, we can gain interesting experimental results regarding engagement situations employing developing weapons and their tactics. Finally, we expect that this work will serve an immediate application for various engagement warfare.

• 한국운동역학회지
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• 제20권4호
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• pp.429-436
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• 2010

The purpose of this study was to analyze the kinematic factors and throwing variables for the 3-turn and 4-turn techniques and for release as well as to provide technical advice for improving athletic performance in hammer throwing. Data analysis led to the following conclusions: To increase the rotation speed for the 3-turn and 4-turn techniques, the time elapsed during the 1-foot support period should be decreased the distance between the rotating foot and the rotation axis should be small and the height of the hip joint should be increased at the times of release The throwing angle at the moment of release should be more than 40 degrees, and the throwing position should be taken vertically high at the shoulder joints. To accelerate the motion of the hammer, the speed should not be reduced during the 1-foot support period but should be increased during the 2-foot support period for much greater acceleration. In the 3-turn technique, the angles of the shoulder axis and hummer string should be dragged angle at the maximum point and lead angle at the minimum point, and dragged angle at the maximum and minimum points in the 4-turn at the time of relase The upper body should be quickly bent backward, the knee angle should be extended, and the angles of the shoulder axis and hammer string should be dragged angle close to 90 degrees.

• 한국정밀공학회지
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• 제27권6호
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• pp.82-89
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• 2010

Ankle-foot orthosis with an artificial pneumatic muscle which is intended for the assistance of plantarfelxion torque was developed. In this study, power pattern of the device in the various pneumatics and the effectiveness of the system were investigated. The pneumatic power was provided by ankle-foot orthosis controlled by user‘s physiological signal, that is, muscular stiffness in soleus muscle. This pneumatic power can assist plantarflexion torque of ankle joint. The subjects performed maximal voluntary isokinetic plantarflexion motion on a biodexdynamometer in different pneumatics, and they completed three conditions: 1) without wearing the orthosis, 2) wearing the orthosis with artificial muscles turned off, 3) wearing the orthosis activated under muscular stiffness control. Through these experiments, we confirmed the effectiveness of the orthosis and muscular stiffness control using the analyzing isokinetic plantarflexion torque. The experimental results showed that isokinetic torques of plantarflexion motion of the ankle joints gradually increased in incremental pneumatic. The effectiveness of the orthosis was -7.26% and the effectiveness of the muscular stiffness control was 17.83% in normalized isokinetic plantarflexion torque. Subjects generated the less isokinetic torques of the ankle joints in wearing the orthosis with artificial muscles turned off, but isokinetic torques were appropriately reinforced in condition of wearing the orthosis activated under muscular stiffness control(17.83%) compared to wearing the orthosis(-7.26%). Therefore, we respect that developed powered orthosis is applied in the elderly that has weak muscular power as the rehabilitation equipment.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제8권1호
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• pp.91-107
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• 2014

Device-to-device (D2D) communication is an excellent technology to improve the system capacity by sharing the spectrum resources of cellular networks. Multicast service is considered as an effective transmission mode for the future mobile social contact services. Therefore, multicast based on D2D technology can exactly improve the spectrum resource efficiency. How to apply D2D technology to support multicast service is a new issue. In this paper, a resource allocation scheme based on cognitive radio (CR) for D2D underlay multicast communication (CR-DUM) is proposed to improve system performance. In the cognitive cellular system, the D2D users as secondary users employing multicast service form a group and reuse the cellular resources to accomplish a multicast transmission. The proposed scheme includes two steps. First, a channel allocation rule aiming to reduce the interference from cellular networks to receivers in D2D multicast group is proposed. Next, to maximize the total system throughput under the condition of interference and noise impairment, we formulate an optimal transmission power allocation jointly for the cellular and D2D multicast communications. Based on the channel allocation, optimal power solution is in a closed form and achieved by searching from a finite set and the interference between cellular and D2D multicast communication is coordinated. The simulation results show that the proposed method can not only ensure the quality of services (QoS), but also improve the system throughput.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제6권1호
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• pp.98-115
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• 2012

New trend called ubiquitous leads the recent business by standardization and integration. It should be the main issue how to guarantee the integration and accountability on each business, especially in mission critical system which is mainly supported by M2M (Machine to Machine) control mechanism. This study is from the analysis of digital forensics case study that is from the M2M Sensing Control Mechanism problem of the "Imjin River" case in 2009, where a group of family is swept away to death by water due to M2M control error. The ubiquitous surroundings bring the changes in the field of criminal investigation to real time controls such as M2M systems. The needs of digital forensics on M2M control are increasing on every crime scene but we suffer from the lack of control metrics to get this done efficiently. The court asks for more accurately analyzed results accounting high quality product development design. Investigators in the crime scene need real-time analysis against the crime caused by poor quality of mission critical systems. It seems to be every need of Real-Time-Enterprise, so called ubiquitous society on the case. We try to find the efficiency and productivity in discovering non-functional design defects in M2M convergence products focusing on three metrics in study model with quick implementation. Digital forensics system in present status depends on know-how of each investigator and is hard to expect professional analysis on every field. This study set up a hypothesis "Co-working of professional investigators on each field will qualify Performance and Integrity" especially in mission critical system such as M2M and suggests "Online co-work analysis model" to efficiently detect and prevent mission critical errors in advance. At the conclusion, this study proved the statistical research that was surveyed by digital forensics specialists around M2M crime scene cases with quick implementation of dash board.

• 한국항행학회논문지
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• 제17권3호
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• pp.279-284
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• 2013

운항의 여러 단계 중 착륙단계에서 조종사들이 많은 부담을 느낀다. 이는 조종사들이 항공기 속도를 줄이고 접지하여 완전히 정지하는 동안 착륙안전에 영향을 미치는 여러 요소가 있기 때문이다. 만일 착륙하는데 활주로길이가 충분하다면 부담이 적을 수도 있다. 그러나 항상 그런 경우만 있는 것은 아니다. 따라서 착륙성능이 제한범위 내에 있는지 아닌지를 확인할 필요가 있다. 필요착륙거리는 시험비행 조종사에 의해 실증되어진 실제착륙거리에다가 항공사의 평균적인 조종사들을 위한 여유분을 포함한 것이다. FAR의 AFM(항공기 비행규정) 인가는 건조 및 습윤 활주로에서 수동착륙을 기반으로 한다. 기타 다른 활주로 조건에서는 인가가 필요하지 않다. JAR에서는 빙설/윤활활주로에서도 정해진 여유분을 포함시키도록 규정하고 있다. 자동착륙은 인가사항이 아니므로 실제착륙거리만 제공된다. 본 논문에서는 각 활주로 조건에서 포함된 거리 여유분을 분석하고자 한다. 또한 특정한 활주로 조건에서 여유분이 규정되어 있지 않은 경우 대안을 제시하고자 한다.

• 한국항행학회논문지
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• 제24권4호
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• pp.314-321
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• 2020

LASAR (logic automated stimulus and response) 소프트웨어는 디지털 전자 회로 카드에 대한 로직 기능시험 및 고장검출을 위한 자동점검프로그램 개발도구이다. LASAR 소프트웨어는 소자의 논리회로 기능 및 입·출력 정의된 정보가 필요하다. 소자 정보가 없으면 정상적인 부품 모델링이 불가능하다. 따라서 본 논문에서는 소자 정보가 없는 PLD (programmable logic device) 소자를 역설계 방법을 통하여 부품 모델링을 수행한다. 개발된 LASAR 프로그램은 고장 시뮬레이션 결과와 단일 고착 고장삽입 방법을 통해 고장 검출율을 확인하였다. 고장 검출율은 기존의 제한적인 모델링은 91%, 역설계를 통한 모델링은 94%로 3% 상승하였다. 또한, EP 310 PLD 소자에 대한 입·출력핀에 대한 22가지 고착결함의 경우 100% 검출하여 양호한 성능을 확인하였다.

• 한국구조물진단유지관리공학회 논문집
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• 제16권2호
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• pp.49-57
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• 2012

최근 교량의 건설에서는 공사기간의 단축 등을 위해 조립식 형태의 교량 시공이 연구되고 있다. 하지만 이는 대부분이 주 구조물인 교각, 거더와 바닥판 등에 국한되어 있고, 조립식 교량에 적합한 방호울타리와 같은 부대시설에 대한 연구는 미흡한 실정이다. 이에 본 연구에서는 조립식 교량 적용을 위한 콘크리트 방호울타리 연결 시스템을 제안하고, 제안된 시스템의 구조적 성능을 검증하기 위하여 정적 실험을 수행 하였다. 변수는 볼트의 수직 수평 접합방식으로 기준실험체와의 비교를 통해 조립식 교량에 적합한 콘크리트 방호 울타리 연결시스템을 제안하고자 하였다. 그 결과, 볼트의 수직접합이 구조적 성능 및 건전성이 일체형의 기준실험체와 거의 동일하다는 것을 알 수 있었고, 조립식교량 적용을 위한 연결시스템으로 적당하다고 판단된다.

• 드라이브 ㆍ 컨트롤
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• 제11권2호
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• pp.30-35
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• 2014

The pumps of electro-hydrostatic actuators operate most frequently in boundary lubrication speed range, as they compensate for the position control errors as a control element. When conventional swash plate type piston pumps are applied to electro-hydrostatic actuators, the frictional power losses as well as the wear rate of sliding components, such as piston shoes can increase drastically under the boundary friction condition. In this paper, the power losses of the piston shoes were investigated which were engendered by a frictional solid-to-solid contact and leakage flow rate of their hydrostatic bearing. In order to reduce them, DLC-coating was applied to the swash plate and the ball joint of pistons along with its effects were demonstrated. In addition, it was also shown that the wear rate of the piston shoes could be markedly reduced using the DLC-coated swash plate.