• Journal of the Institute of Electronics and Information Engineers
• /
• v.52 no.12
• /
• pp.55-63
• /
• 2015

Recently, terroristic threats using a radio controlled improvised explosive device (RCIED) that is remotely controlled and exploded have been increased around the world. In order to prevent the explosion of an RCIED, jamming techniques that interrupt an RCIED receiver can be used, so that the receiver can not demodulate the trigger code. Conventional jamming technique is a type of active barrage jamming that always emits the noise jamming signal for all the frequency band. However, it needs large power consumption and thus is limited in operation time for a vehicle. In order to overcome the shortage of the active barrage jamming, reactive jamming technique has drawn attention. In reactive jamming, all the frequency band is firstly scanned, and then if any trigger signal exists, one emits the jamming signal to the corresponding frequency band. Therefore, the reactive jamming is superior to the active barrage jamming in terms of power efficiency. However, a reactive jammer emits a jamming signal only after the trigger signal is intercepted, which means that the jamming signal may be late for interrupting an RCIED receiver. In this sense, it is needed to evaluate a delay in an RCIED receiver. To achieve this, we analyze the reaction time and present the simulation result for jamming performance of reactive jamming against an RCIED using mobile devices.

• The Journal of The Korea Institute of Intelligent Transport Systems
• /
• v.2 no.1 s.2
• /
• pp.41-52
• /
• 2003

The purpose of this study was to test the effects of the pedestrian green signal adjustment on clearance of the turning vehicles impeding the through traffic flow at the signalized intersections, and thereby, suggest some operational criteria for adjustment of the pedestrian green signal. In order to test such effects, the pedestrian green time was adjusted so that it could started a few seconds later than the vehicle green time during peak hours, and thereby, the turning vehicle volume not cleared at the intersection was measured by extending the time gap by 2 seconds. (In general, the pedestrian green signal turns on at the same time as the vehicle green signal.) The results of this test can be summed up as follows; first, the longer the time gap was, the turning vehicle volume not cleared from the intersection decreased more. Second, in case there existed a storage space between intersection and crosswalk the effect of the turning vehicles on the through traffic flows was minimal. Third, at the pelican, the effect of the turning vehicles on the through traffic flow was minimal due to the structure of the intersection and the phase sequence. In conclusion, it was found that the adjustment of pedestrian green signal had the effect of enhancing the intersection operation. When adjusting the pedestrian green signal, it was deemed necessary to thoroughly survey the geometric structure of the intersection and collect the data on the turning traffic volume and thereby, apply the results of analysis flexibly to each intersection.

• Proceedings of the Korean Information Science Society Conference
• /
• 2005.11a
• /
• pp.595-597
• /
• 2005

청소로봇은 대부분 랜덤방식 또는 바둑판식의 청소알고리즘으로 운용된다. 랜덤 알고리즘은 전체 청소 시간이 오래 걸린다는 단점을 가지고 있다. 랜덤 알고리즘의 문제를 해결하기 위한 바둑판식 알고리즘은 현재까지 가장 좋은 알고리즘으로 알려져 있으나 장애물이 복잡한 공간에서는 청소시간이 길어지는 단점을 가지고 있다. 이런 문제점을 해결하기 위하여 본 논문에서는 Group-k 라는 새로운 청소 알고리즘을 제안한다. Group-k 알고리즘은 청소시간을 단축시키는 목적보다는 청소시간은 같더라도 복잡한 구역일수록 나중에 청소함으로써 가능한 빠른 시간 내에 가장 많은 면적을 청소하는 것을 목표로 한다. 즉 인접한 복잡한 장애물들을 하나의 그룹으로 구성하고 그룹의 복잡성을 계산하여 복잡성이 낮은 그룹부터 먼저 청소하는 방식이다. 시뮬레이션에 기반한 실험을 통해 Group-k 알고리즘이 복잡한 장애물 구역을 그룹화하여 복잡한 공간을 효율적으로 청소함을 보여준다.

• Proceedings of the Korea Society for Simulation Conference
• /
• 1999.10a
• /
• pp.313-318
• /
• 1999

상호 운용성을 높이기 위해 제안된 HLA(High Level Architecture)는 분산되어 있는 모델과 사용자간의 실시간 상호 정보 교환의 구현이 가능하게 이종의 시간 관리 기반을 제공하는 장점이 있다. 본 논문에서는 동적 구조를 가지는 Wireless Network상에서 발생되는 메시지의 동적 라우팅을 RTI를 기반으로 구현하고, 그 결과로 HLA의 실시간 상호 정보교환에 대한 이점을 확인하여 실시간 분산 시뮬레이션에 대한 적용 가능성을 평가한다.

• Proceedings of the Korea Society for Simulation Conference
• /
• 1999.04a
• /
• pp.169-173
• /
• 1999

HLA(High Level Architecture)는 시뮬레이션 모델간의 상호 운용성(Interoperability)을 높이기 위해 제안되었고, 분산되어 있는 시뮬레이션 모델간의 데이터 교환 및 시뮬레이션 시간 진행을 조정하는 등 여러 가지 장점을 가진 분산 시뮬레이션에 적합한 구조이다. 본 논문에서는 자동차 주행 시뮬레이션을 HLA를 기반으로 구현하고, HLA의 실시간 분산 시뮬레이션에 대한 적용 가능성을 확인한다.

• Defense and Technology
• /
• no.3 s.289
• /
• pp.58-65
• /
• 2003

접이식 방호부양장치체계 설계안은 전투장갑차의 부양장치로서 요구되는 부력, 방호성, 독자적 수상운행성을 위한 탑재운용성, 수상운행 준비시간을 최소화하는 구동장치의 최적화 및 수상안정성 극대화 등을 충족시키면서도 중량 증가 요인은 최소화하는 것이 가능할 것으로 검토된 바, 기존 방법으로는 기대할 수 없는 높은 수준의 수상운행성능 구현이 가능할 것으로 기대된다.

• Journal of the Korean Society for Aeronautical & Space Sciences
• /
• v.39 no.6
• /
• pp.567-575
• /
• 2011

The development of space launch vehicle is an important step to advance to developed countries in the space area. It is also so risky due to necessity of huge costs and longer development period. The accuracy of cost estimation is important to develop a space launch vehicle successfully and efficiently. It is also necessary to estimate production and operation cost in order to develop commercial space launch vehicle possessing competitiveness. In this paper, Korean factors to be able to reflect the current state of workforce, average working hours and technology readiness level in Korea were analyzed to estimate production and operation cost of space launch vehicles that are developed in Korea. Korean factors have been applied to production and operation cost estimation of KSLV-II based on TRANSCOST. We evaluated the competitiveness level of KSLV-II as the commercial launch vehicle in the commercial launch services market by comparing with cost per flight of foreign launch vehicles.

• Journal of the Korea Society of Computer and Information
• /
• v.20 no.6
• /
• pp.87-97
• /
• 2015

An Aerial video summarization is not only the key to effective browsing video within a limited time, but also an embedded cue to efficiently congregative situation awareness acquired by unmanned aerial vehicle. Different with previous works, we utilize sensor operation mode of unmanned aerial vehicle, which is global, local, and focused surveillance mode in order for accurately summarizing the aerial video considering flight and surveillance/reconnaissance environments. In focused mode, we propose the moving-react tracking method which utilizes the partitioning motion vector and spatiotemporal saliency map to detect and track the interest moving object continuously. In our simulation result, the key frames are correctly detected for aerial video summarization according to the sensor operation mode of aerial vehicle and finally, we verify the efficiency of video summarization using the proposed mothed.

• Journal of the Korea Society of Computer and Information
• /
• v.16 no.3
• /
• pp.75-87
• /
• 2011

Tactical Data Links are standardized radio communication data links for military armed forces and used to transmit and receive data. Because they are the core elements of achieving information superiority in a NCW environment, various kinds of TDL are used by the Korean armed forces. Operating various types of TDL is very helpful in getting more information; however, at the same time, it is hard to integrate and make them co-operate with other TDLs or C4ISR systems. In this paper, we propose a XML based messaging system to make various types of TDL interoperable in a NCW environment. For the messaging system between TDL and C4ISR systems, we define XML message processing interfaces and suggest binary XML for serialization to save transmission loads over constrained military communication bandwidth. Our experiment results show that the TDL message can be transformed into generalized XML data that is interoperable with other TDLs and binary XML serialization, and it saves parsing and transmission time.

• Journal of Navigation and Port Research
• /
• v.31 no.3 s.119
• /
• pp.205-212
• /
• 2007

Due to the construction of Incheon Grand Bridge, there is driven a necessity for rearranging the function of Inner Port with the development of Outer South Port. In this paper, I'd like to simulate the port operation levels of Lock Gate in Inner Port with estimating the traffic volumes of 2011 and 2015, which will reveal the Demurrage Cost and the Accumulation Cost of Freight in Inner Port. Finally I will evaluate the economic movement effects of the container ship's calling from Inner port to South Port/Outer South Port from 2011 to 2015. The results are as followings ; (1) The average utilization of Lock Gates are reduced by $7\sim8$ percentage point. (2) The mean queueing value are saved by 25 percentage point. (3) The Demurrage Cost and the Accumulation Cost of Freight except Lock Gate charges and the Benefit of Routeing Reduction are saved about 800 million Won annually.