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Learning Automata Based Multipath Multicasting in Cognitive Radio Networks

  • Ali, Asad;Qadir, Junaid;Baig, Adeel
    • Journal of Communications and Networks
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    • v.17 no.4
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    • pp.406-418
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    • 2015
  • Cognitive radio networks (CRNs) have emerged as a promising solution to the problem of spectrum under utilization and artificial radio spectrum scarcity. The paradigm of dynamic spectrum access allows a secondary network comprising of secondary users (SUs) to coexist with a primary network comprising of licensed primary users (PUs) subject to the condition that SUs do not cause any interference to the primary network. Since it is necessary for SUs to avoid any interference to the primary network, PU activity precludes attempts of SUs to access the licensed spectrum and forces frequent channel switching for SUs. This dynamic nature of CRNs, coupled with the possibility that an SU may not share a common channel with all its neighbors, makes the task of multicast routing especially challenging. In this work, we have proposed a novel multipath on-demand multicast routing protocol for CRNs. The approach of multipath routing, although commonly used in unicast routing, has not been explored for multicasting earlier. Motivated by the fact that CRNs have highly dynamic conditions, whose parameters are often unknown, the multicast routing problem is modeled in the reinforcement learning based framework of learning automata. Simulation results demonstrate that the approach of multipath multicasting is feasible, with our proposed protocol showing a superior performance to a baseline state-of-the-art CRN multicasting protocol.

Performance of H.264 SVC with Base Layer Repetition and HARQ over Wireless Link (무선링크에서 기본 계층의 반복과 HARQ를 적용한 H.264 SVC의 성능)

  • Ahn, Sung-Kyun;Han, Dong-Ha;Hwang, Seung-Hoon
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.37 no.8A
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    • pp.689-697
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    • 2012
  • In this paper, we propose base layer repetition and HARQ schemes for improving the reliability and the performances of H.264 SVC video transmission in a wireless channel, and investigate its performances. The proposed method may solve the problems of transmission delay as well as the scarcity of wireless resources, since the proposed scheme was applied for only base layer, not for enhancement layer. The numerical results show that the proposed scheme can enhance the BER performance of $1.5{\times}10^{-5}$ and the FER of $1.2{\times}10^{-3}$, when SNR=3.4dB. Also, it was confirmed through the resultant images that the proposed method can improve the SVC performance in the wireless link.

Partially Distributed Dynamic Model for Secure and Reliable Routing in Mobile Ad hoc Networks

  • Anand, Anjali;Aggarwal, Himanshu;Rani, Rinkle
    • Journal of Communications and Networks
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    • v.18 no.6
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    • pp.938-947
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    • 2016
  • A mobile ad hoc network (MANET) is a collection of mobile nodes communicating in an infrastructure-less environment without the aid of a central administrating authority. Such networks entail greater dependency on synergy amongst the nodes to execute fundamental network operations. The scarcity of resources makes it economically logical for nodes to misbehave to preserve their resources which makes secure routing difficult to achieve. To ensure secure routing a mechanism is required to discourage misbehavior and maintain the synergy in the network. The proposed scheme employs a partially distributed dynamic model at each node for enhancing the security of the network. Supplementary information regarding misbehavior in the network is partially distributed among the nodes during route establishment which is used as a cautionary measure to ensure secure routing. The proposed scheme contemplates the real world scenario where a node may exhibit different kinds of misbehavior at different times. Thus, it provides a dynamic decision making procedure to deal with nodes exhibiting varying misbehaviors in accordance to their severity. Simulations conducted to evaluate the performance of the model demonstrate its effectiveness in dealing with misbehaving nodes.

Study on Fashion Design Applying Felt (펠트(Felt)를 이용한 의상 디자인 연구)

  • Oh Yean-Ok
    • Journal of the Korea Fashion and Costume Design Association
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    • v.8 no.1
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    • pp.59-67
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    • 2006
  • In textile industry of $21^{st}$ century, to develop materials and designs in fashion industry is being recognized widely as an urgent problem. In other words, the reality is that we must offer scarcity value and unique materials, and make a positive effort in a time when consumers' individuality appeals and an interest in fashion becomes higher. Felt is not only the oldest material in human history, but also a technique, and its applications are being handed down broadly. I have made various materials based mainly on a traditional felt technique using merino wool and nuno felt technique felting merino wool to cotton gauze. In nuno felt thing, I could observe that as wool and cotton was created as a single composite material, each material's aesthetic, sensuous, functional and emotional description became much more diversified. The purpose of this study is to produce fashion materials using materials with rich texture to meet the consumers' preference and diversity which are increasingly individualized, to design them and to seek possibility of developing differentiated wool materials which can satisfy the consumers' individuality demand and preference.

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Malignant Fibrous Histiocytoma of the Maxilla: A Case Report (상악골에 발생한 악성 섬유성 조직구종 1례)

  • Song, Seung Yong;Kim, Yong Oock;Park, Beyoung Yoon;Tark, Kwan Chul
    • Archives of Plastic Surgery
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    • v.34 no.3
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    • pp.388-391
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    • 2007
  • Purpose: Malignant fibrous histiocytoma (MFH) is mainly a soft tissue sarcoma containing fibroblast-like cells and histiocytic cells. MFH in bone accounts for 5% of all malignant bone tumors. MFH of the maxilla is extremely rare and difficult to diagnose due to its scarcity. Treatment mainstay is a complete surgical excision. Radiation therapy is also available when surgery alone is incomplete. Prognosis is not clear but can be devastating. Authors report one case of MFH developed in the maxilla. Methods: A 24-year-old man firstly diagnosed as fibrous dysplasia based on CT findings. Considering facial contour, partial excision was done. But pathology report confirmed malignant fibrous histiocytoma and secondary wide excision was done including zygoma and grossly all affected area. After surgery, radiation therapy was continued. Results: There are no evidence of tumor recurrence after clinical and radiological treatment. Conclusion: MFH of maxilla is very rare and this can leads to misdiagnosis in many clinicians. Surgeon should differentiate this disease from fibrous dysplasia and pathology and MRI are accurate methods for diagnosis of MFH.

The Characteristics and Meaning of Art Collaboration in the Luxury Louis Vuitton Brand -Focusing on Bags Since 2000- (럭셔리 브랜드 루이 비통(Louis Vuitton)의 아트 콜라보레이션 특징과 의미 -2000년 이후 가방을 중심으로-)

  • Kim, Hyunjeong;Park, Hyewon
    • Journal of Fashion Business
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    • v.24 no.2
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    • pp.100-118
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    • 2020
  • The purpose of this study was to identify the characteristics and meaning of collaboration with artists who have been with Louis Vuitton, focusing on bags, which are representative products of the luxury Louis Vuitton brand, -The research method was literature research and case studies. The theoretical study was based on previous studies and literature examine the concept and type in collaboration and to examine the trend in fashion and art collaboration. The case study was conducted after 2000 by collecting collaborative works between Louis Vuitton and artists based on their homepage, fashion information, and collection sites. Five artists and six artists(Sam Falls, Urs Fischer, Nicholas Hlobo, Alex Israel, Tschabalala Self and Jonas Wood), including Stephen Sprouse, Richard Prince, Takashi Murakami, Kusama Yayoi, and Jeff Koons, were analyzed for the art collaboration cases and contents that were conducted mainly on bags. This study found the following collaboration characteristics: first, classic image innovation: fun and lightness; second, deviating from the boundaries of fashion bags: the art of life, and third, building high-end luxury brand differentiation: scarcity and the introduction of authorism. It is expected that the basic data will be presented in the study of art collaboration design of fashion bags as well as academic data on the differentiation of luxury brands and the artisticization of products in the future.

E-Business Platform for SMEs in GMS Countries

  • Yi, Hong;Zhou, Yue;Wang, Yuan-liang;Liu, Qian-Hua
    • Proceedings of the Korea Society for Industrial Systems Conference
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    • 2007.02a
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    • pp.213-223
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    • 2007
  • E-Business Platform for SMEs in GMS Countries(GMSEB) is a E-business service portal which based on Yunnan, face to ASEAN, connect with China's mainland. lt is established by Kunming Dongxun Sic&Tech Co.,Ltd and E-Business Centre of Yunnan University of Financial & Economics, who get supports from UNESCAP, Science and Technology Department of Yunnan Provincial and Yunnan SMEs Bureau. The portal will bulid a B2B & B2C E-business and. ASP portal to provide service of e-business and enterprise management informatization according with the different languages and situation to China and GMS countries. The paper starts with analysis of the policy in China of promoting GMS cooperation and exchanges, importance of Yunnan and cultural universality in GMS countries. It expounds the necessity of establishing such a regional e-commerce platform. The project explores how to develop the model of e-business and enterprise management informationization for SMEs under the condition of weak economic strength and scarcity of Information Technology talents. To promote the SMEs in GMS countries participate in the integration with the global economy through the international SMEs'E-business Platform, make a fairly rapid progress by full play to its advantages.

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Trends and Implications of International Standardization for Rare Earths (희토류 관련 국제표준 동향 및 시사점)

  • Abbas, Sardar Farhat;lee, Sang-Hyun;Lee, Bin;Kim, Bum-Sung;Kim, Taek-Soo
    • Journal of Powder Materials
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    • v.25 no.2
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    • pp.165-169
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    • 2018
  • Rare earth elements (REEs) are considered to be vital to modern industry due to their important roles in applications such as permanent magnets, automobile production, displays, and many more. The imbalance between demand and supply of REEs can be solved by recycling processes. Regarding the needs of industry and society, the International Organization for Standardization, Technical Committee 298 (ISO/TC298) Rare Earths has been recently launched for developing international standards on rare earth elements. In accordance with the suggestion of its constituents, it is tentatively working to develop the appropriate standards under five working groups (WG) on terms and definitions (WG1), element recycling (WG2), environmental stewardship (WG3), packaging, labelling, marking, transport, and storage (WG4), and testing analysis (WG5). The scope and structure of ISO/TC298 on the topic of rare earths is discussed in this document.

Perceived Value Dimensions of Up-cycling Fashion Goods and the Relationship with Attitude and Purchase Intention -The Moderating Effect of Fashion Innovativeness- (업사이클링 패션제품의 지각된 가치 차원과 태도 및 구매의도의 관계 -유행혁신성의 조절효과-)

  • Park, Hyun Hee
    • Journal of the Korean Society of Clothing and Textiles
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    • v.39 no.2
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    • pp.257-270
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    • 2015
  • This study investigates the effect of perceived value on attitude and purchase intention of upcycling fashion goods. The study also examines the effect of perceived value on attitudes according to fashion innovativeness. The qualitative data analysis results from NVivo 10.0 showed that consumers paid attention to the creative design value, environmental value, scarcity value of upcycling fashion goods. Next, 201 effective questionnaires were analyzed using SPSS 22.0 and AMOS 20.0. The results are as follows. First, there were 5 factor solutions for the perceived value of up-cycling fashion goods: environmental value, creative design value, functional value, emotional value, and self-expression value. Second, environmental value, functional value, and self-expression value positively affected attitude; however, creative design value and emotional value did not affect attitude. Third, attitude positively influenced purchase intention of upcycling fashion goods. Fourth, there was a significant difference in the magnitude of the effect of self-expression value on attitude according to fashion innovativeness. The results of this study provide useful information for marketers or managers interested in upcycling fashion goods.

An Oligopoly Spectrum Pricing with Behavior of Primary Users for Cognitive Radio Networks

  • Lee, Suchul;Lim, Sangsoon;Lee, Jun-Rak
    • KSII Transactions on Internet and Information Systems (TIIS)
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    • v.8 no.4
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    • pp.1192-1207
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    • 2014
  • Dynamic spectrum sharing is a key technology to improve spectrum utilization in wireless networks. The elastic spectrum management provides a new opportunity for licensed primary users and unlicensed secondary users to efficiently utilize the scarce wireless resource. In this paper, we present a game-theoretic framework for dynamic spectrum allocation where the primary users rent the unutilized spectrum to the secondary users for a monetary profit. In reality, due to the ON-OFF behavior of the primary user, the quantity of spectrum that can be opportunistically shared by the secondary users is limited. We model this situation with the renewal theory and formulate the spectrum pricing scheme with the Bertrand game, taking into account the scarcity of the spectrum. By the Nash-equilibrium pricing scheme, each player in the game continually converges to a strategy that maximizes its own profit. We also investigate the impact of several properties, including channel quality and spectrum substitutability. Based on the equilibrium analysis, we finally propose a decentralized algorithm that leads the primary users to the Nash-equilibrium, called DST. The stability of the proposed algorithm in terms of convergence to the Nash equilibrium is also studied.