• International Journal of Naval Architecture and Ocean Engineering
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• v.10 no.1
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• pp.95-102
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• 2018

This paper proposes a dual lifting and its cooperative control system with two different kinds of floating cranes. The Mega-erection and Giga-erection in the ship building are used to handle heavier and wider blocks and modules as ships and off-shore platforms are enlarged. However, there is no equipment to handle such Tera-blocks. In order to overcome the limit on performance of existing floating cranes, the dual lifting is proposed in this research. In the dual lifting, two floating cranes are well-coordinated to add up the lift capabilities of both cranes without any loss such that virtually a single crane is lifting, maneuvering and unloading. Two main constraints for the dual lifting are as follows: First, two barges of floating cranes should be constrained as a rigid body not to cause a relative motion between two barges and main hooks of the two cranes should be controlled as main hooks of a single crane. In order words, it is necessary to develop the cooperative control of two floating cranes in order to sustain a center of gravity of the module and minimize the tilting angle during the lifting and unloading by the two floating cranes. Two floating cranes are handled as a master-slave system. The master crane is able to gather information about all working conditions and make a decision to control the individual hook speed, which communicates the slave crane by TCP/IP. The developed control system has been embedded in the real floating crane systems and the dual lifting has been demonstrated five times at SHI shipyard in 2015. The moving angles of the lifting module are analyzed and verified to be suitable for hoisting control. It is verified that the dual lifting can be applied for many heavier and wider blocks and modules to shorten the construction time of ships and off-shore platforms.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.23 no.12
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• pp.1406-1411
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• 2012

An energy detection based spectrum sensing has been found to be vulnerable to the noise power uncertainty. A cooperative spectrum sensing with an energy detector has appeared as one of the solutions to alleviate this difficulty. However, its performance analysis in a fading environment has not been reported yet in the literature. Motivated by this, this paper presents the performance analysis of the scheme by extending our previous work on evaluating the performance of an energy detector in the presence of noise power uncertainty. The analysis shows that the false alarm probability and detection probability gets higher as the sensing time and/or the number of the secondary users in the OR based cooperative spectrum sensing scheme increase when the noise power uncertainty exists.

• Journal of Aerospace System Engineering
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• v.18 no.2
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• pp.1-11
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• 2024

This paper applies a relative impact angle control guidance law to a communication-based multi-missile network system with uncertainties and disturbances. The multi-missile network system is represented as a transitive reduction directed acyclic graph. Furthermore, this paper introduces both centralized and decentralized guidance laws based on the graph's structure. The relationship between these guidance laws is analyzed by comparing them based on the communication structure and the presence of system noise. To analyze the effects of decentralized optimal cooperative guidance law, this paper assumes uncertainty in missile dynamics and predicted impact point information for the relative impact angle control mission. Monte Carlo simulations are conducted for various mission environments to analyze the impact of communication and its structure on the system.

• Journal of the Korean Mathematical Society
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• v.43 no.2
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• pp.297-309
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• 2006

In this paper, we consider cooperative games arising from integer domination problem on graphs. We introduce two games, ${\kappa}-domination$ game and its monotonic relaxed game, and focus on their cores. We first give characterizations of the cores and the relationship between them. Furthermore, a common necessary and sufficient condition for the balancedness of both games is obtained by making use of the technique of linear programming and its duality.

• Information and Communications Magazine
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• v.30 no.10
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• pp.10-17
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• 2013

본고에서는 차량통신을 통하여 차량간 협력을 하여 정보를 교환하는 C-ITS(cooperative intelligent transportation system)를 위한 최신 차량 통신 기술과 개발 현황을 소개한다. 그리고 C-ITS의 궁극적 목표인 차량 주행 안전의 확보와 원활한 교통흐름을 위한 차량 주변 상황 인지 기술에 대한 기술 개발현황을 소개하여 차세대 ITS 시스템의 발전방향을 알아본다.

• Asia pacific journal of information systems
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• v.16 no.3
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• pp.229-241
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• 2006

In this paper, we develop three stage non-cooperative game models to analyze the alliance strategies of companies in internet markets where network effects are present. Regardless of its market share, an internet company's strategic alliance appears to be a superior strategy. The analysis also identifies profit sharing structures in the internet market where a smaller and unknown company is enforced to split its own profits with a larger and well-known company. It is shown that the amount of profit sharing grows as the size of network effects becomes larger.

• Journal of Korean Library and Information Science Society
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• v.21
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• pp.325-361
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• 1994

The Library of Congress' proposal to license LC MARC database and the following debate over the proposal shows that the issue on ownership of bibliographic databases, which surfaced as a topic of concern in the international library community with the OCLC's a n.0, pplication for copyright of its databases in 1982, is not fading or dead into the 1990s. In particular, the way that technological developments are outpacing the ability of the relevant organizations and legal systems to make necessary adjustments is giving the library profession a warning that cooperative efforts for further development of the international library systems, such as the UBC program, might be seriously impeded without a swift and amicable agreement on the controversial 'database ownership' issue. Here, the purpose of this paper lies in discussing the 'database ownership' issue from a macro and long-term perspective, with emphasis on its potential impacts on, and implications for, international information flows. To the end, the specific questions covered in this paper include : 1) what are the major causes of the database ownership controversy? 2) what are the potential impacts of the database ownership issue on the library profession's cooperative efforts toward free bibliographic information flows at the international level? And finally, 3) what are the implications of the database ownership issue for the Korean Library Community, which is making efforts toward the establishment of a national library network in near future through linking various library automation systems.

• Management Science and Financial Engineering
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• v.10 no.2
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• pp.1-28
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• 2004

The integrated supply chain of business partners for e-Commerce in cyber space is defined as Logistics Chain if the cooperative activities are logistics-related. Logistics Chain could be managed effectively and efficiently by cooperative technologies of logistics chain execution. In this paper, we propose a routing and scheduling algorithm based on the Tabu search by adding geographical information into existing constraint for pick-up and delivery process to minimize service time and cost in logistics chain. And, we also consider an uncertainty processing for the tracing of moving object to control pick-up and delivery vehicles based on GPS/GIS/ITS. Uncertainty processing is required to minimize amount of telecommunication and database on vehicles tracing. Finally, we describe the Logistics Chain Execution (LCE) system to perform plan and control activities for postal logistics chain. To evaluate practical effects of the routing and scheduling system, we perform a pretest for the performance of the tabu search algorithm. And then we compare our result with the result of the pick-up and delivery routing plan generated manually by postmen.

• Journal of Korean Library and Information Science Society
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• v.44 no.3
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• pp.309-333
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• 2013

The purpose of this study is to analyze the mutual cooperations of school and public libraries in Japan, and to investigate the possibility of its application to Korea. To the end, discussed in details are the characteristics and limitations of cooperative activities between school and public libraries in Japan. The major contents of this study are as follows: First, analyzed are the present conditions of school libraries in Japan, with emphasis on human resources, facilities, and school library policies. Second, comprehensively investigated are the cooperation projects of school and public libraries which have been conducted by the central and local governments. Finally, discussed are the meanings of library cooperations in Japan and its implications for Korea.

• Journal of Agricultural Extension & Community Development
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• v.18 no.4
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• pp.793-824
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• 2011

This study is to explore implications for sustainable development of Yangdong Village in Gyeongju through identifying effect of its designation as a World Cultural Heritage on residents' quality of life. The following are the findings achieved by empirical analysis. First, eight valuable factors of placeness were identified through factor analysis, about which residents were especially conscious in terms of "living condition", "cultural environment", "economic QOL", "natural environment conservation", "sense of community", "cooperative facilities", "control over increasing population", "transport environment". Second, the importance -satisfaction scores of identified 8 factors were found very high in importance showing relatively low level of low level of satisfaction. Especially, what caused residents's low QOL was economic status-concerned factor showing the lowest QOL index, and other factors such as cooperative facilities and transport environment negatively impacted on resident's QOL as well. Also, it was revealed that residents had a positive attitude toward entering of their village into UNESCO world heritage sites with hope that it would improve their economic QOL. Based on these results, implications for sustainability of Yangdong Village and research limitations were discussed, and further research direction was supposed.