• KSII Transactions on Internet and Information Systems (TIIS)
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• v.7 no.11
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• pp.2874-2892
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• 2013

Since security plays an important role in several ZigBee applications, such as Smart Energy and medical sensor applications, ZigBee Specification includes various security mechanisms to protect ZigBee frames and infrastructure. Among them, the Join and Leave operations of ZigBee are investigated in this paper. The current Join-Leave operation is protected by the network key (a kind of group key). We claim it is not adequate to employ the network key for such purpose, and propose a new Join-Leave operation protected by the application link key (a kind of pairwise key), which is based on a more efficient key management scheme than that of ZigBee. Hence, the original Join operation consists of a total of 12 command frames, while the new Join operation consists of only 6 command frames. In particular, the security of the proposed Join-Leave operation is equivalent to or better than that of the original Join-Leave operation. The new Join-Leave operation is extensively analyzed in terms of security and efficiency, and compared with the original Join-Leave operation of ZigBee.

• Journal of KIISE:Information Networking
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• v.30 no.2
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• pp.222-232
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• 2003

In accordance with the changes in the wireless communication environment, there has been a great need to satisfy the demand for diverse modes of information exchange. Various types of short-distance wireless communication technology have been developed and studied to meet this demand. Among them, Bluetooth which has recently been acclaimed as the standard for short-distance wireless communication, has been the focus of many such studies. However, Bluetooth has weaknesses in its suuity features when its in security services are applied to Home networks. The purpose of this study is to propose a safe Bluetooth scenario with an upgraded suity feature. This paper first reviews the general characteristics and security features of Bluetooth together with an analysis of its weaknesses, and presents the formation and maintenance process of Bluetooth piconet what is created by using ECDSA and group key in the ACL(Asynchronous Connection-less Link) connection through a safe Bluetooth inquiry process.

• The Journal of the Korea Contents Association
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• v.8 no.3
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• pp.47-54
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• 2008

In order to realize Intelligent Transport System (ITS) without any road facilities support, Inter-vehicle Communication (IVC) is increased attention. IVC makes it possible to exchange real-time information among vehicles without centralized infrastructure. The IVC systems use multi-hop broadcast to disseminate information. In this paper, we propose the improved AODV routing protocol based on location information. The proposed AODV routing protocol transmits Hello packet with location information to calculate the distance between nodes. Then it achieves fast link recovery. We confirm the throughput performance of the proposed AODV routing protocol compared with the AODV routing protocol using Qualnet ver.3.8 simulator.

• Proceedings of the Korea Contents Association Conference
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• 2015.05a
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• pp.15-16
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• 2015

Measuring sensor, equipment, ICT facilities and their software have relatively short life time comparing to constructional structure so that we should exchange or fix them continuously in the process of maintenance and management. In this paper, we propose a novel design of integrated maintenance, management, and measuring monitoring system applying the concept of mobile cloud. For the sake of disaster prevention for constructional structures such as bridge, tunnel, and other traditional buildings in the village of local heritage, we analyze status of these structures in the long term or short term period as well as disaster situations. Collecting data based on mobile cloud and analyzing future expectations based on probabilistic and statistical techniques, we implement our integrated monitoring system for constructional structures to solve these existing problems. Final results of this design and implementation are basically applied to the monitoring system for more than 10,000 structures spread over national land in Korea. In addition, we can specifically apply the monitoring system presented here to a bridge of timber structure in Asan Oeam Village and a traditional house in Andong Hahoe Village to watch them from possible disasters. Total procedure of system design and implementation as well as development of the platform LinkSaaS and application services of monitoring functions implemented on the platform. We prove a good performance of our system by fulfilling TTA authentication test, web accommodation test, and operation test using real measuring data.

• Journal of Distribution Science
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• v.18 no.5
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• pp.5-13
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• 2020

Purpose: The aim of this article is to test the link between growth of loan distribution and Bank Valuation in Vietnam's banking sector. At the same time, the study also compared the differences in the effect of growth of loan to valuation bank in banks of different sizes, ownership rates and bank values. Research design, data and methodology: With panel data estimation techniques along with robust standard error for a sample of the banks listed on Vietnam stock exchange from 2012 to 2019. Results: Growth of loan has a positive impact on Bank Valuation (by Tobin's Q). A closer investigation provides evidence for the differential valuation effect of loan growth depending on different features of banks. Specifically, loan growth is found positively and significantly associated with Bank Valuation in small and non-state-owned banks only. Besides, bank size, deposit, and return on equity are found negatively associated with Tobin's Q, while loan loss provisions exhibit a positive relation with this measure of Bank Valuation. Conclusions: These findings provide contributions to the literature on the existence of the effect of loan growth on Bank Valuation. At the same time, the study also provides practical implications for policy makers in banks and investors.

• The Journal of Fisheries Business Administration
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• v.12 no.2
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• pp.61-71
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• 1981

This essay examines the marketing of Fishermen's Cooperative in Korea, and in particular considers the marketing channel of fisheries products, No company can perform by itself all the activities involved in the production and distribution of its products and services to its final markets. It must work with other firm to get the job done. Thus marketing channel firms of the fisheries products include primarily the Fishermen's Cooperative the licensed dealers and tile merchant middlemen, The goal of marketing is in matching of segments of supply and demand. Every producer seeks to the link the marketing channel firms that will help it accomplish its objective best. Therefore this study surveys the three types of marketing channels through tile central market That. is, they are a marketing channel through the terminal market, a marketing channel through the fishermen's cooperative terminal market, and a marketing channel through the private fish market. Consequently the Fishermen's Cooperative can choose to improve in any of tile marketing channel as follows: \circled1 The Fishermen's Cooperative is nominated wholesaler in the terminal market. \circled2 It is abolished to sell by double auction in the production district terminal market and the consuming city terminal market of Fishermen's Coopertive. \circled3 The steady wholesalers in private fish market are entitled to the licensed dealers. \circled4 The Fishermen's Cooperative sponsored voluntary chains join with retailer, supermarkets, consumers' society. Therefore the study of marketing channel of fisheries products can appropriately referred to satisfying needs and wants through exchange process.

• Journal of Digital Convergence
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• v.12 no.12
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• pp.323-328
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• 2014

D-MAC protocol is used convergence network, which is designed to connect wireless link between things. This protocol is supported to local data exchange and aggregation among neighbor nodes, and distributed control packet from sink to sensor node. In this paper, we analysis about efficiency of power consumption according to whether or not security authentication of D-MAC in convergence network. If authentication scheme is applied to MAC communication, it is related to power consumption of preamble whether or not with and without authentication process. It is reduced to energy consumption against denial attack of service, when it is applied to authentication. Future work will take the effort to deal with security authentication scheme.

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.2 no.2
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• pp.52-59
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• 2003

Cam mechanism is a machine part frequently used in machinery. Specially, conjugate cam mechanism is very suitable for the high speed working and the heavy power translation. Then a conjugate cam mechanism need high precision for the relations between cam profiles and follower rollers. So, its design and manufacturing are very difficult. Thus, this study is a branch of exclusive CAM systems for design and NC machining of conjugate earn mechanism based on a master plate earn profile in order to exchange an old plate cam mechanism to a new conjugate earn mechanism. For the design of the other cam profile by using a master cam profile, some calculation processes were used by vector summation methods, from master cam profile data to the center data of master follower, from the center data of master follower to the center data of the other follower considered in link mechanism, and offsetting in the center direction of base circle of the other cam from the center data of the other follower. Finally, a sample conjugate cam was selected and machined m order to prove the contents of this study.

• The Journal of Asian Finance, Economics and Business
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• v.4 no.3
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• pp.35-43
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• 2017

This paper explores the impact of corporate control, measured by ownership structure, on top-executives' compensation in Japan. According to agency theory, the pay-performance link is expected to be affected by the firm's ownership structure. Using a sample of 4,411 firm-year observations (401 firms for the 11-years period from 2001 to 2011) for Japanese non-financial firms publicly traded on the first section and second section of the Tokyo Stock Exchange (TSE), this study demonstrates that institutional ownership (both financial and corporate) is negatively related to the level of executives' compensation. Such finding is in line with efficient monitoring hypothesis which claims that the presence of institutional shareholders provides direct monitoring over managers, limits managerial self-dealing and curves the increase in top-executives pay. On the other hand, the results also show that managerial ownership is positively related to their compensation which supports managerial power theory hypothesis, i.e. management-controlled firms are more likely to extract more compensation from the business than other firms. Overall, this study confirms that corporate control has significant impact on cash compensation paid to Japanese top-executives after controlling the conventional pay-performance relationship.

• Archives of Plastic Surgery
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• v.41 no.4
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• pp.414-417
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• 2014

Serratia marcescens (S. marcescens) emerged as an opportunist in the setting of immunodeficiency in the 1970s, when serious infections occurred in San Francisco hospitals after USA. Navy experiments had aerosolized the bacteria to study biologic warfare. We investigate the risks of S. marcescens in San Franciscans who undergo mastectomy with implant reconstruction. From 2007 to 2011, the senior author took breast capsule cultures for all patients at the time of tissue expander exchange/explant. Of the 142 women who had reconstruction, 23 had positive cultures. Only the two patients who were positive for S. marcescens developed clinical infections that required explantation. Both had postoperative chemotherapy with transient neutropenia, and both had close ties to San Francisco. Clinical signs of infection emerged for both patients months after initial surgery, despite having previously well healed incisions. Other patients were culture positive for Pseudomonas, Proteus, Enterococcus and MRSA and did not develop require explant. While the link between San Francisco and S. marcescens is controversial, a patient's geography is a simple screening tool when considering postoperative risks, especially in the immunocompromised. Closer monitoring for neutropenia during chemotherapy, and a lower threshold to administer S. marcescens targeted antibiotics may be warranted in these patients.