• Title/Summary/Keyword: Coexistence problem

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Distributed Time Division Piconet Coexistence Using Local Time Offset Exchange (로컬 오프셋을 이용한 분산 시간 분리 피코넷 충돌회피 방법론)

  • Park, Yongsuk
    • Journal of the Korea Institute of Information and Communication Engineering
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    • v.18 no.6
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    • pp.1447-1453
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    • 2014
  • Wireless Body Area Networks (WBAN), standardized as IEEE 802.15.6, enable digital devices on/around the human body to communicate with one another. WBAN is essentially a person's piconet consisting of a master (mobile) device and several slave devices, which follows his/her mobility pattern, and hence, occasionally collides with another piconet as people meet or pass by. As such, a mechanism to detect collision and avoid interference is needed for intra-piconet communications. In this paper, we focus on this notorious problem of piconet collision and propose Distributed Time Division Piconet Coexistence (DTDPC) using local time offset exchange as a simple, attractive solution. The proposed DTDPC provides different level of services for various applications. Besides our simulation results have shown that the proposed solution outperforms the conventional CSMA protocols.

Ethical Fashion Design (윤리적 패션 디자인)

  • Ko, Hyun-Zin
    • Journal of the Korean Society of Costume
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    • v.60 no.8
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    • pp.151-167
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    • 2010
  • This research is to analyze ethics in fashion design for more valuable and sustainable human life against the increasing alienation of the human being, the global ecological crisis resulted from contemporary consumption society. I expect that it can be helpful to plan ethical fashion design practice more effectively. For this, the documentary study and practical case study have been executed. The results are as follows. The ethics in design can be defined as the responsibility to reform the social, environmental problem of consumptive design, to sustain together without human alienation, environment disruption and to do social good for total human being ultimately. The ethical design practice means to suggest solutions to problems of human rights and environment and to act willingly. Based on this, ethical fashion design appeared as responsible design solution which has two directions. One is the fashion design for coexistence and sharing, including the design for all which considers even underprivileged minority, the design to promote public issues as well as to donate some profits. The other is the eco fashion design for sustainable environment, including eco-friendly design which is reductive and slow in whole design process, the design to inform the seriousness of environmental crisis as well as to donate some profits. The last one of the most important ethical responsibility as fashion designer is to abide by vocational ethics, that is, the prohibition of design piracy.

Interference Avoidance Technology Using Cognitive UWB in Ultra Wideband Systems (Cognitive UWB 기술을 이용한 UWB 시스템에서의 간섭 회피 기술)

  • Hwang, Jae-Ho;Sohn, Sung-Hwan;Lee, Sung-Jun;Kim, Jae-Moung
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.32 no.8A
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    • pp.836-846
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    • 2007
  • Wireless Communication is playing a key role in implementing the ubiquitous society. However, due to the increasing wireless and mobile devices occupying the spectrum, the frequency resources are believed to become more and more limited. In order to deal with the problem, coexistence is considered to be a effective method to improve the efficiency of spectrum utilization between several different systems. Here, we utilize the UWB system to realize the coexistence, because it is an ultra wide band system which can co-exist with other narrow band systems. On the other hand, Cognitive Radio technology is an intelligent technology which can sense the spectrum environment and adaptively adjust the parameters for wireless transmission. In this paper, by using Cognitive UWB, the spectrum efficiency of the transmission channels is largely improved; Furthermore, the interference to other systems can be effectively avoided.

An Integrated Game Theoretical Approach for Primary and Secondary Users Spectrum Sharing in Cognitive Radio Networks

  • Kim, Jong-Gyu;Nguyen, Khanh-Huy;Lee, Jung-Tae;Hwang, Won-Joo
    • Journal of Korea Multimedia Society
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    • v.14 no.12
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    • pp.1549-1558
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    • 2011
  • In this paper, we address the problem of bandwidth sharing among multiple primary users and multiple secondary users in a cognitive radio network. In cognitive radio networks, effective spectrum assignment for primary and secondary users is a challenge due to the available broad range of radio frequency spectrum as well as the requisition of harmonious coexistence of both users. To handle this problem, firstly, Bertrand game model is used to analyze a spectrum pricing in which multiple primary users emulate with each other to acquire maximal profit. After that, we employ Cournot game to model the spectrum sharing of secondary users to obtain optimal profit for each user also. Simulation results show that our scheme obtains optimal solution at Nash equilibrium.

A Coexistence Model in a Dynamic Platform with ICT-based Multi-Value Chains: focusing on Healthcare Service (ICT 기반 다중 가치사슬의 동적 플랫폼에서의 공존 모형: 의료서비스를 중심으로)

  • Lee, Hyun Jung;Chang, Yong Sik
    • Journal of Intelligence and Information Systems
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    • v.23 no.1
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    • pp.69-93
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    • 2017
  • The development of ICT has leaded the diversification and changes of supplies and demands in markets. It also caused the creations of a variety of values which are differentiated from those in the existing market. Therefore, a new-type market is created, which can include multi-value chains which are from ICT-based created markets as well as the existing markets. We defined the platform as the new-type market. In the platform, the multi-value chains can be coexisted with multi-values. In true market, when a new-type value chain entered into an existing market, it is general that it can be conflicted with the existing value chain in the market. The conflicted problem among multi-value chains in a market is caused by the sharing of limited market resources like suppliers, consumers, services or products among the value chains. In other words, if there are multi-value chains in the platform, then it is possible to have conflictions, overlapping, creations or losses of values among the value chains. To solve the problem, we introduce coexistence factors to reduce the conflictions to reach market equilibrium in the platform. In the other hand, it is possible to lead the creations of differentiated values from the existing market and to augment the total market values in the platform. In the early era of ICT development, ICT was introduced for improvement of efficiency and effectiveness of the value chains in the existing market. However, according to the changed role of ICT from the supporter to the promotor of the market, ICT became to lead the variations of the value chains and creations of various values in the markets. For instance, Uber Taxi created a new value chain with ICT-based new-type service or products with new resources like new suppliers and consumers. When Uber and Traditional Taxi services are playing at the same time in Taxi service platform, it is possible to create values or make conflictions among values between the new and old value chains. In this research, like Uber and traditional taxi services, if there are conflictions among the multi-value chains, then it is necessary to minimize the conflictions in the platform for the coexistence of multi-value chains which can create the value-added values in the platform. So, it is important to predict and discuss the possible conflicted problems between new and old value chains. The confliction should be solved to reach market equilibrium with multi-value chains in the platform. That is, we discuss the possibility of the coexistence of multi-value chains in the platform which are comprised of a variety of suppliers and customers. To do this, especially we are focusing on the healthcare markets. Nowadays healthcare markets are popularized in global market as well as domestic. Therefore, there are a lot of and a variety of healthcare services like Traditional-, Tele-, or Intelligent- healthcare services and so on. It shows that there are multi-suppliers, -consumers and -services as components of each different value chain in the same platform. The platform can be shared by different values that are created or overlapped by confliction and loss of values in the value chains. In this research, as was said, we focused on the healthcare services to show if a platform can be shared by different value chains like traditional-, tele-healthcare and intelligent-healthcare services and products. Additionally, we try to show if it is possible to increase the value of each value chain as well as the total value of the platform. As the result, it is possible to increase of each value of each value chain as well as the total value in the platform. Finally, we propose a coexistence model to overcome such problems and showed the possibility of coexistence between the value chains through experimentation.

A Study on Middle School Students' Perception on Intelligent Robots as companions. (지능형 로봇과의 공존에 대한 중학생들의 인식 조사)

  • Kim, YangEun;Kim, HyeonCheol
    • The Journal of Korean Association of Computer Education
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    • v.22 no.4
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    • pp.35-45
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    • 2019
  • How future generations perceive coexistence with intelligent robots is an important element of how SW and artificial intelligence education should be designed and conducted. This study conducted a survey of 214 first graders in middle school and looked at differences in understanding and perception of coexistence through empathy and expected problem situations depending on the type of intelligent robot. As a result of the analysis, Firstly, if the form was not explicit, it was recognized as a top-down relationship, and Second, in the case of human form, it was ready to recognize intelligent robots and communicate with them. Third, Many people were feeling Emotion in the Robot shape AI. Fourth, there was a vague sense of uneasiness about simple mechanical robots. The study is meaningful as a case study to confirm awareness of intelligent robots and needs to consider and establish awareness of whether they can coexist and live together with robots by age group as well as middle school students.

A Convergence Study on Partial Dental Hygiene (Department) and Student Satisfaction: Focusing on Approach Motivation, Avoidance Motivation, and Digital Use Recognition (일부 치위생(학)과 학생의 학과 만족도에 관한 융합연구 : 접근 동기, 회피 동기, 디지털 사용인식 중심으로)

  • Son, Eun Gyo
    • Journal of the Korea Convergence Society
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    • v.13 no.5
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    • pp.53-60
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    • 2022
  • The purpose of this study is to identify the causal relationship of the structural model through approach motivation, avoidance motivation, and digital usage recognition in order to prepare a plan for coexistence with dental hygiene targeting 239 students from the dental hygiene department at a university in Gangwon-do. For statistical methods, SPSS Statistics 24.0 program and AMOS 21.0 were used. As a result of the structural equation model analysis, the motivation for approach was found to be significantly related to digital usage recognition and class satisfaction. In addition, digital usage perception was found to be significantly related to class satisfaction, and class satisfaction was shown to be significantly related to department satisfaction and department recommendation. Lastly, department satisfaction was significantly found in department recommendation. In other words, the coexistence plan with dental hygiene (department) is to expand the convergence of digital classes. In order to solve the problem, it is necessary for schools to establish facilities to expand teaching materials for practical classes and to devise teaching methods.

A Flexible Network Access Scheme for M2M Communications in Heterogeneous Wireless Networks

  • Tian, Hui;Xie, Wei;Xu, Youyun;Xu, Kui;Han, Peng
    • KSII Transactions on Internet and Information Systems (TIIS)
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    • v.9 no.10
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    • pp.3789-3809
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    • 2015
  • In this paper, we deal with the problem of M2M gateways' network selection for different types of M2M traffic in heterogeneous wireless networks. Based on the difference in traffic's quality of service (QoS) requirements, the M2M traffic produced by various applications is mainly classified as two categories: flexible traffic and rigid traffic. Then, game theory is adopted to solve the problem of network-channel selection with the coexistence of flexible and rigid traffic, named as flexible network access (FNA). We prove the formulated discrete game is a potential game. The existence and feasibility of the Nash equilibrium (NE) of the proposed game are also analyzed. Then, an iterative algorithm based on optimal reaction criterion and a distributed algorithm with limited feedback based on learning automata are presented to obtain the NE of the proposed game. In simulations, the proposed iterative algorithm can achieve a near optimal sum utility of whole network with low complexity compared to the exhaustive search. In addition, the simulation results show that our proposed algorithms outperform existing methods in terms of sum utility and load balance.

Nonlinear model inversion missile control with disturbance accommodating control (외란 적응 제어를 적용한 미사일 비선형 제어)

  • 조현식;김인중;김진호
    • 제어로봇시스템학회:학술대회논문집
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    • 1996.10b
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    • pp.1500-1503
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    • 1996
  • This paper combines the disturbance accommodating control(DAC) and nonlinear model inversion control for a skid-to-turn(STT) missile. The missile autopilot may be designed to be robust with respect to a variety of uncertainties. We proposes the two step control design method. Nonlinear model inversion control is used as the main design method. Due to the model uncertainties and external disturbances, the exact nonlinear model inversion can not be achieved. DAC is designed to detect, to identify, and to compensate these uncertainties. DAC's disturbance observer is linear. Thus it is easy to implement. It does not cause the convergence problem due to coexistence between the modeling uncertainties and external disturbances. 6 DOF simulation results show that the proposed method may improve the missile tracking performance.

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The Traits of International Marriage in Rural Korea (한국농촌의 국제결혼의 특징)

  • Lim, Hyung-Baek
    • Journal of Agricultural Extension & Community Development
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    • v.14 no.2
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    • pp.471-491
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    • 2007
  • The purpose of this study were (1) to thumbnail sketch of present general condition of foreigners and international marriage in Korea, (2) to study special trend of international marriage in rural Korea, particularly immigration connected with poverty, and (3) to focus on prospect of the problem of mixed-bloods, especially half blood children in rural Korea. Many of foreigners were treated discriminatingly, for example racial discrimination and wage discrimination. And discrimination to mixed-blood children will be happen in future. They are in a disadvantageous position because of economic status and appearances. Half blood children have korean nationality because one of his parent is korean. When they grow up and reach their the age of puberty and the age of working, they will resist to discrimination in working and marriage. I had examined precedent studies, and class theory in general, and to suggest it is time to looking for way of reduce social cost and way of coexistence.

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