• ETRI Journal
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• 제46권2호
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• pp.175-183
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• 2024

Recently, polar code has attracted the attention of many scholars and has been developed as a code technology in coded-cooperative communication. We propose a polar code scheme based on Plotkin structure and quasi-uniform punching (PC-QUP). Then we apply the PC-QUP to coded-cooperative scenario and built to a new coded-cooperative scheme, which is called PCC-QUP scheme. The coded-cooperative scheme based on polar code is studied on the aspects of codeword construction and performance optimization. Further, we apply the proposed schemes to space-time block coding (STBC) to explore the performance of the scheme. Monte Carlo simulation results show that the proposed cooperative PCC-QUP-STBC scheme can obtain a lower bit error ratio (BER) than its corresponding noncooperative scheme.

• 자동차안전학회지
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• 제15권3호
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• pp.34-42
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• 2023

Simulation-based virtual testing is known to be a major requirement for verifying the safety of autonomous driving functions. However, in the simulation environment, there is a difficulty in that all driving environments related to the autonomous driving system must be realistically modeled. In particular, C-ITS (Cooperative-Intelligent Transport Systems) is essential for urban autonomous driving of Lv.4, but the approach to modeling for C-ITS service in the MILS (Model in the Loop Simulation) environment is not yet clear. Therefore, this paper aims to deal with V2X (Vehicle to Everything) modeling methods to effectively apply C-ITS-based autonomous cooperative driving services in the MILS environment. First, major C-ITS services and use cases for autonomous cooperative driving are analyzed, and a modeling method of V2X signals for C-ITS service simulation is proposed. Based on the modeled V2X messages, the validity of the proposed approach is reviewed through simulations on the C-ITS service use case.

• International Journal of Fuzzy Logic and Intelligent Systems
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• 제2권3호
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• pp.185-190
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• 2002

In distributed autonomous robotic systems (DARS), each robot must behave by itself according to its states ad environments, and if necessary, must cooperate with other robots in order to carry out their given tasks. Its most significant merit is that they determine their behavior independently, and cooperate with other robots in order to perform the given tasks. Especially, in DARS, it is essential for each robot to have evolution ability in order to increase the performance of system. In this paper, a schema co-evolutionary algorithm is proposed for the evolution of collective autonomous mobile robots. Each robot exchanges the information, chromosome used in this algorithm, through communication with other robots. Each robot diffuses its chromosome to two or more robots, receives other robot's chromosome and creates new species. Therefore if one robot receives another robot's chromosome, the robot creates new chromosome. We verify the effectiveness of the proposed algorithm by applying it to cooperative search problem.

• 한국ITS학회 논문지
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• 제9권1호
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• pp.34-41
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• 2010

본 논문에서는 복조후 전송 (DF: Decode-and-Forward) 중계기를 사용하는 협력통신 (Cooperative Communication) 시스템에서 동일 채널로 전송된 다른 신호에 의해 단말기에 발생할 수 있는 간섭 완화 방법에 대해 분석하고 실험하였다. 간섭완화 방법은 동일 채널로 전송할 신호를 직교 부호를 이용하여 부호화한 후 전송하면, 수신기는 미리 알고 있는 직교 부호를 이용하여 자신이 원하는 신호만 수신하는 것이다. 본 논문에서 이용한 직교 부호는 직교 골드 부호 (Orthogonal Gold Code) 를 이용하였다. 하지만 직교 골드 부호 이외에 직교 성질을 가지는 다른 부호를 직교 부호로 사용할 수 있다. 또한 추가적인 배열 이득으로 인해 시스템 성능을 향상시키기 위해 시공간 블록 부호화 (STBC : Space Time Block Coding) 개념을 적용하였다.

• 한국ITS학회 논문지
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• 제21권1호
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• pp.91-104
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• 2022

Level 3 자율주행차의 상용화가 가시화됨에 따라 자율주행차의 운행설계영역(ODD)이 고속도로 외 도심도로로 확대될 필요가 있다. 본 연구는 도심도로 내 인프라-자율차 간 협력주행 기반의 자율주행차 서비스에 대한 교통운영효율성 및 안전성 측면의 효과평가를 통해 도심도로 자율협력주행 서비스의 실효성을 분석하였다. 도심도로 자율협력주행 서비스의 구현 및 효과평가는 미시교통시뮬레이션모델을 활용하였으며, 각 서비스별 중점관리목표에 따른 개별적인 효과평가 지표를 선정하여 효과 분석에 활용하였다. 분석 결과, V2X 통신 기반의 자율협력주행 서비스를 통해 자율주행차량의 교통운영 효율성과 안전성이 향상됨을 확인하였고, 그 효과는 자율주행차의 시장점유율이 증가할수록 커지는 것으로 분석되었다. 본 연구는 단속류인 도심도로를 대상으로 V2X 통신 기반의 자율협력주행 서비스의 효과를 도출해낸 것에 의의가 있으며, 향후 자율협력주행 서비스 검증 기반이 마련되는데 기초자료로 활용될 수 있을 것으로 기대된다.

• 한국ITS학회 논문지
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• 제21권1호
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• pp.258-272
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• 2022

안전한 자율주행을 위하여 차량 센서에만 의존하는 Stand-alone 방식의 한계를 극복하기 위한 방법으로, 노변의 인프라와 자율주행차간 정보를 교환하는 '자율협력주행' 방식의 기술 개발이 이루어지고 있다. 이 과정에서 협력의 대상이 되는 동적정보는 통신 데이터 손실 측면의 평가방법이 일반적이지만, 정보로서 역할 중심의 평가방법이 필요하다. 본 연구에서는 자율협력주행에서 동적정보 서비스 역할의 적정성을 평가하기 위하여 역할 기반 평가방법을 제안하였다. 평가 척도로 검출률, 검출 소요시간, LDM 처리시간을 제안하였고, 평가방법론을 검증하기 위하여 실제 도로에서 보행자 정보를 대상으로 실증 실험을 시행하였다. 실험 결과로는 검출률 99%, 소요시간 200ms/건, 처리시간 19ms/건을 얻었다. 향후 제안된 동적정보 서비스 평가 방법이 관련 정보제공 서비스의 평가에 활용되기를 기대한다.

• Strategy21
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• 통권34호
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• pp.5-25
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• 2014

On July 3~4, 2014, the Chinese President Xi Jinping's state visit to Seoul might be seen as a step on the path toward strategic outcomes for both country. For South Korea, Seoul shrewdly retains some degree of self-reliance by balancing between ROK-China strategic cooperative partnership relationship and ROK-US alliance. For China, Beijing appears to put its interests on the Korean Peninsula increasingly within China's larger geopolitical influence. To what extent can ROK-China relationship maintain futuristic strategic cooperative partnership between them? As we observed joint press communiques of the Chinese President Xi Jinping's state visit on July 3, 2014, four agendas of bilateral relationship between Seoul and Beijing can be identified: intractable rivalry between the two great powers, North Korea nuclear issues, disparities of their displeasure with Japan denying the past wrongdoing and enhancing its military capabilities and Chinese imposing of its core interests on its Korea policy. With these evolving strategic environments, however, China and the ROK appear justifiably be pleased with the state of their relations: their strategic cooperative partnership is the cornerstone of peace and prosperity in the Asia-Pacific or Indo-Pacific region and continues to grow broader and deeper.

• 한국중재학회지:중재연구
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• 제31권3호
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• pp.91-107
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• 2021

The Korean Association of Arbitration Studies faces its 30th anniversary in 2020 since its foundation in 1991 and is being celebrated and congratulated across the communities in and out of the country. However, the association seems to be standing at crossroads between a negative and positive direction. As shown in the past KAAS pattern in its academic activities, the academic community tends to focus relatively more on domestic issues, expanding its domestic network rather than international network for the past years. KAAS needs to turn its face to see the other side of the world, stretching its hands to the people outside first. For this purpose, this paper suggests that KAAS should strengthen its cooperative capability through the international cooperation division. KAAS' past 30 years of accumulated know-how and its academic network will play critical roles i-n expanding its partners across the global academic community. This paper delivers special thanks to the institutions, including the LMAA, CAC, SIAC, HKIAC, RSPP/ACRU, IDAC, and LAMC who sent cooperative works and congratulatory messages to KAAS 30th anniversary despite the COVID-19 pandemic situation.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제8권2호
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• pp.355-370
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• 2014

Cooperative spectrum sensing has been considered as a promising approach to improve the sensing performance in distributed cognitive radio networks. However, there may exist some selfish secondary users (SUs) who are unwilling to cooperate. The presence of selfish SUs could cause catastrophic damage to the performance of cooperative spectrum sensing. Following the social perspective, we propose a Social Tie-based Incentive Scheme (STIS) to deal with the selfish problem for cooperative spectrum sensing in distributed cognitive radio networks. This scheme inspires SUs to contribute sensing information for the SUs who have social tie but not others, and such willingness varies with the strength of social tie value. The evaluation of each SU's social tie derives from its contribution for others. Finally, simulation results validate the effectiveness of the proposed scheme.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 2003년도 ICCAS
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• pp.728-733
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• 2003

In human-mechanical cooperative systems, a significant issue is to improve the control performance and the maneuvering feeling of human operation. However, since it is not easy to evaluate the feeling of operators numerically, control engineers design controllers only through experience. Thus, in this paper, a new evaluation method for control performance of human-mechanical cooperative system is proposed based on the reserge waveform. Various distortions of waveform represent deteriorations of control performance and maneuvering feeling. In some cases, since there is a tradeoff between the control performance and the maneuvering feeling, it is difficult to compensate for both of them by usual feedback controllers. To overcome this situation, the two degrees of freedom control system is applied to human-mechanical cooperative system. Some numerical simulation results for an electric power steering system are shown to confirm the effectiveness of proposed control design method.