• 전자통신동향분석
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• 제38권4호
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• pp.104-115
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• 2023

Communication for multiagent reinforcement learning (MARL) has emerged to promote understanding of an entire environment. Through communication for MARL, agents can cooperate by choosing the best action considering not only their surrounding environment but also the entire environment and other agents. Hence, MARL with communication may outperform conventional MARL. Many communication algorithms have been proposed to support MARL, but current analyses remain insufficient. This paper presents existing communication algorithms for MARL according to various criteria such as communication methods, contents, and restrictions. In addition, we consider several experimental environments that are primarily used to demonstrate the MARL performance enhanced by communication.

• 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.

• 한국항해학회지
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• 제16권2호
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• pp.53-78
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• 1992

GMDSS-the Global Maritime Distress and Safety system which is utilizing the new technologies such as satellite communication system, DSC and NBCP-is effectuated not only by the amendment of SOLAS but also by the conference of RR and IMO's MSC, and will be the major factor of the variation of the demand and supply of Radio Operators. To cope with the GMDSS voluntarily, regulations relating to the radio installation, the posting of Radio Operators, the bounds of duty, etc. must be established and the demand and supply of Radio Operators which take charge of the system must be accomplished pertinently. In this study, the authors suggested some practical schemes to improve the effect of policy as follow. 1. The Ministry of Communication must supervise strictly the arrangement of Radio Operators, especially relating tot he legally qualified complement of Radio Station, and must review the official certification system to upgrade the quality of Radio Operators. 2. The Ministry of Communication must take overall charge of the qualitifications and technical standards of Radio Operators, the extent of their engagement, etc. which are provided by International Regulations. 3. Relating Administrations must cooperate with Shipping Companies in onboard-training to foster and ensure the manpower of Radio Operators. 4. Institutional devices to drive the resolute investment in education and training for mariners, especially for the ship's officers, must be prepared. 5. The Communication Administration and the Korea Maritime and Port Adminstration(KMPA) must cooperate mutually in the balance of the demand and supply of Radio Operators and use make their best to realize more harmonious policies on the demand and supply of manpower.

• 기술사
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• 제42권6호
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• pp.28-30
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• 2009

There is a proverb in Korea "Don't chase after another." It can be a right proverb in sometimes. However, usually it doesn't fit in these various society, information knowledge society. Modern society requires convergence technology. IBS (Intelligent Building System) requires knowledge of architecture field, electric field, communication field, and computation field. ITS (Intelligent Transport Systems) which is constructing in many cities requires various knowledge as engineering works, electricity, computation, communication and transportation. In the case of u-City, it requires technology of many fields as architecture, electricity, communication, engineering works, transportation, and computation. Anyone who wants to participate in u-City should study and acquire knowledge in various field. Otherwise, it must be failed because of lack of communication like as the Tower of Babel. U-City is not a portion of one field. Therefore, engineers in many fields should cooperate with each other to make u-city as the best product in the world.

• 한국정보기술응용학회:학술대회논문집
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• 한국정보기술응용학회 2005년도 6th 2005 International Conference on Computers, Communications and System
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• pp.161-164
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• 2005

As the power of influence of the Internet grows steadily, attacks against the Internet can cause enormous monetary damages nowadays. A worm can not only replicate itself like a virus but also propagate itself across the Internet. So it infects vulnerable hosts in the Internet and then downgrades the overall performance of the Internet or makes the Internet not to work. To response this, worm detection and prevention technologies are developed. The worm detection technologies are classified into two categories, host based detection and network based detection. Host based detection methods are a method which checks the files that worms make, a method which checks the integrity of the file systems and so on. Network based detection methods are a misuse detection method which compares traffic payloads with worm signatures and anomaly detection methods which check inbound/outbound scan rates, ICMP host/port unreachable message rates, and TCP RST packet rates. However, single detection methods like the aforementioned can't response worms' attacks effectively because worms attack the Internet in the distributed fashion. In this paper, we propose a design of distributed worm detection system to overcome the inefficiency. Existing distributed network intrusion detection systems cooperate with each other only with their own information. Unlike this, in our proposed system, a worm detection system on a network in which worms select targets and a worm detection system on a network in which worms propagate themselves cooperate with each other with the direction-aware information in terms of worm's lifecycle. The direction-aware information includes the moving direction of worms and the service port attacked by worms. In this way, we can not only reduce false positive rate of the system but also prevent worms from propagating themselves across the Internet through dispersing the confirmed worm signature.

• 반도체디스플레이기술학회지
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• 제18권4호
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• pp.40-45
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• 2019

The smart factory has developed with the help of several technologies such as automation, artificial intelligence, big data, smart sensors and communication protocols. The Internet of things(IOT) among communication protocols has become the key factor for the seamless integration of various manufacturing equipment. Therefore, it is important that the IOT cooperate with the standards of communication protocols proposed by the SEMI in the semiconductor industry. In this paper, we suggest a novel reference model of the communication protocols for semiconductor equipment by introducing an IOT service layer. With the IOT service layer, we can use the functions and the additional services provided by the IOT standards that give the inter-operability between factory machines and host computers. We implement the standard of the communication protocols for semiconductor equipment with the IOT service layer by using ns3 simulator. It concludes that it is necessary to provide the platform for the IOT service layer to deploy efficiently the proposed reference model of the communication protocols.

• 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.

• ETRI Journal
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• 제20권2호
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• pp.149-170
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• 1998

Between a wide range of distributed applications, this work is particularly focused on those applications which allow a group of persons, who are geographically distributed, to interact and cooperate exchanging different kind of information in order to realize group activities in a common work environment. In this paper we realized a study of this kind of applications to identify general and functional characteristics which will then enable us to determine their communication requirements. Also, we analyzed the existent support architectures to examine whether they support multimedia cooperative applications. Based on the results of analysis, we proposed a set of communication functions needed additionally to support these applications, using the ODP(Open Distributed Processing) modelling concepts, rules and view points as our global design methodology.

• 무역학회지
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• 제44권3호
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• pp.105-121
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• 2019

This study applies diverse game theories to the US-China Trade War. The US-China Trade War can be analyzed as a game situation because the strategic decision-making process to maximize one's profit while considering the reaction of the other party is a game situation. However, related research suffered from some mistakes in applying the US-China Trade War as it is to classic game theory, because while the prisoners dilemma is based on the situation of No Communication, No Trust, No Cooperation, the US-China Trade War has a precondition different from that of prisoners dilemma, since it mutually communicates information and negotiation is repeated several times in a cooperative situation. The result of the trade negotiation will likely end as 'cooperate-cooperate'. Further, considering trade volume, trade interdependence, bargaining power based on economy, and the scale of damage caused by the Trade War, the US-China Trade War is progressing with the bargaining power of the US being higher than that of China. Since the current US-China Trade War is in an asymmetrical situation under the dominant bargaining power of the US, it is likely to reach 'US defect-China cooperative' in the long run.

• 대한수학교육학회지:수학교육학연구
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• 제8권1호
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• pp.145-162
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• 1998

This study investigated the effect of teaching mathematical communication in mathematics learning. Cooperative learning, mathematics pin pals, and writing a mathematics diary were used to teach how to communicate mathematically. The experimental group was assigned to cooperate in class, to write a mathematics diary at the end of each class, and to exchange the mathematics pen pals once a week. The control group was taught by the traditional teaching method. The results were analyzed quantitatively and qualitatively. The learning achievement between the two groups was performed with pretests and posttests. And after this study, mathematics pen pals, video protocol and open-ended test were analyzed. The results of this study are the following: 1. There were little differences in learning achievement test between the group taught through communication and those not. And there were little differences in the results of achievement test between the two groups-high and low level classes.2. Cooperative learning, writing a mathematics diary and mathematics pen pals were effective as methods of teaching communication mathematically. The analysis of mathematics pen pals which is to investigate student's writing abilities showed that pen pal partners were improved in QCAI communication levels. There was a significant difference between the two groups in open-ended test. This means that communication learning has an effect on the tests for mathematical thought, reasoning, and creative thought. The analysis of video protocol showed that four students in a cooperative group were improved in their speaking and listening abilities.