• IEIE Transactions on Smart Processing and Computing
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• v.1 no.2
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• pp.95-105
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• 2012

The widespread implementation of RFID in ubiquitous computing is constrained considerably by privacy and security unreliability of the wireless communication channel. This failure to satisfy the basic, security needs of the technology has a direct impact of the limited computational capability of the tags, which are essential for the implementation of RFID. Because the universal application of RFID means the use of low cost tags, their security is limited to lightweight cryptographic primitives. Therefore, EPCGen2, which is a class of low cost tags, has the enabling properties to support their communication protocols. This means that satisfying the security needs of EPCGen2 could ensure low cost security because EPCGen2 is a class of low cost, passive tags. In that way, a solution to the hindrance of low cost tags lies in the security of EPCGen2. To this effect, many lightweight authentication protocols have been proposed to improve the privacy and security of communication protocols suitable for low cost tags. Although many EPCgen2 compliant protocols have been proposed to ensure the security of low cost tags, the optimum security has not been guaranteed because many protocols are prone to well-known attacks or fall short of acceptable computational load. This paper proposes a remedy protocol to the flyweight RFID authentication protocol proposed by Burmester and Munilla against a desynchronization attack. Based on shared pseudorandom number generator, this protocol provides mutual authentication, anonymity, session unlinkability and forward security in addition to security against a desynchronization attack. The desirable features of this protocol are efficiency and security.

• Imaging Science in Dentistry
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• v.45 no.2
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• pp.117-122
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• 2015

Purpose: Panoramic radiographs taken using conventional chin-support devices have often presented problems with positioning accuracy and reproducibility. The aim of this report was to propose a new bite block for panoramic radiographs of anterior edentulous patients that better addresses these two issues. Materials and Methods: A new panoramic radiography bite block similar to the bite block for dentulous patients was developed to enable proper positioning stability for edentulous patients. The new bite block was designed and implemented in light of previous studies. The height of the new bite block was 18 mm and to compensate for the horizontal edentulous space, its horizontal width was 7 mm. The panoramic radiographs using the new bite block were compared with those using the conventional chin-support device. Results: Panoramic radiographs taken with the new bite block showed better stability and bilateral symmetry than those taken with the conventional chin-support device. Patients also showed less movement and more stable positioning during panoramic radiography with the new bite block. Conclusion: Conventional errors in panoramic radiographs of edentulous patients could be caused by unreliability of the chin-support device. The newly proposed bite block for panoramic radiographs of edentulous patients showed better reliability. Further study is required to evaluate the image quality and reproducibility of images with the new bite block.

• Journal of the Ergonomics Society of Korea
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• v.29 no.5
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• pp.751-762
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• 2010

The purpose of this study was to investigate the job stress factors of aircraft composite material part manufacturing workers using survey based on 'Job stress factors evaluation tool for Koreans' that was developed by KOSHA in 2003. Two hundred and fifty workers participated in this study, and among them 204 responses were analyzed for this study due to the unreliability and insincerity of responses. The eight job stress factors which are physical environment, job autonomy, job insecurity, organizational system, workplace culture, unfair compensation, relationship conflict, and job requirement were analyzed. The results showed that the stress level of the six job stress factors which are physical environment, job autonomy, job insecurity, organizational system, workplace culture, unfair compensation was relatively higher than that of other industry workers. Generally, all eight job stress factors showed higher stress with temporary workers than with permanent workers, and especially job autonomy, job insecurity, organizational system, and unfair compensation factors showed statistically significant differences (p<0.05). Since the temporary workers are insecure with their job, weak position in organization, having little self-control for the job and lower pay level than that of permanent workers though the job is as same as permanent workers', the stress level of above job stress factors would be much higher than that of the other factors. The group of unsatisfactory with workplace showed higher job stress than group of satisfactory with workplace in all job stress factors, as expected, at the statistically significance level (p<0.05). From the results of this study, the work loss due to the job stress could be prevented, and accurate stress factors could be removed at the workplace. Also the job stress management program can be implemented to improve the work efficiency and the workers' quality of life.

• Korean Journal of Community Nutrition
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• v.2 no.3
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• pp.388-395
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• 1997

A survey was conducted to investigate housewives' perception and consumption of Korean fermented foods marketed in Taejon. Most subjects know how to prepare Kimchi(seasoned and fermented vegetables), 65-67% can make Kochujang(fermented red pepper soybean paste), Toenjang(Korean style soysauce) and Jang-atchies(pickled basic side dishes), 56% can make Kuk-ganjang(Korean style coysauce), 45% can make Chonggukjang (fermented soybean) and 34% can make Jot-kals(salt-fermented fish products). With decreasing age(p<0.0001), not many other subjects could make other fermented foods besides Kimchi. The percentages of subjects buying fermented foods were 71.5% for Chin-ganjang(Japanese style soysauce), 51.7% Jot-kals, 27.1%Kochujang, 25.7% Chonggukjang, 20.1% Jang-atchies, 10.4% Toenjang, 5.9% Kuk-ganjang, and 3.8% Kimchi. the uounger in age, the higher the tendency to buy marketed Kimchies(p<0.05) and Kochujang(p<0.01). The resons for purchasing fermented foods were convenience (52.9%), lack of preparation knowledge(17.5%), lack of time for preparation(12.5%), and lack of space for food storage(8.2%). Subjects indicated that their reasons for mot buying were as follows : use of additives or unreliability with regard to manufacturing dates(45%), bad taste(21%), unsanitary treatment(16%) and to keep their indigenous taste(14%). They cosidered expiration dates, taste, crpteria and safety as the important standard in selecting marketed foods. Younger subjects insisted on the improvement of sanitary condition and partial change of taste to increase the consumption of fermented foods. However, older subjects thought it best to keep the taste original for more utilization of fermented foods.

• Journal of the Economic Geographical Society of Korea
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• v.3 no.1
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• pp.5-20
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• 2000

Recently as globalization of financial capital is progressed, possibility of crisis and unreliability of world economy is more growing. Korean economy required radical restructuring because of the financial crisis and the economic changes occurred in that process. This study is to explain the economic changes of Gwanagju city is produced by the financial crisis of Korean economy The most important industries are service and transportation equipment in Gwangju city. These industries began to decrease after financial crisis but machinery equipment, electrical machinery & electronics and rubber goods & plastic industry is growing relatively. Because of the decrease of service, the economy of inner city which service industry relatively agglomerated in is reducing. And agglomeration space for the optical photonics industry was built up by the upbringing policy of government on high-technology industry to overcome the economic crisis and micro industrial space such as venture building and establishment nursery center was built up. But high-technology industries have many geographical limits to embed in Gwanagju city, so there needs to construct regional innovation system for knowledge based economies

• International Journal of Highway Engineering
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• v.14 no.6
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• pp.121-129
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• 2012

PURPOSES : Traffic accidents at intersections have been increased annually so that it is required to examine the causations to reduce the accidents. However, the current existing accident models were developed mainly with non-linear regression models such as Poisson methods. These non-linear regression methods lack to reveal complicated causations for traffic accidents, though they are right choices to study randomness and non-linearity of accidents. Therefore, to reveal the complicated causations of traffic accidents, this study used structural equation methods(SEM). METHODS : SEM used in this study is a statistical technique for estimating causal relations using a combination of statistical data and qualitative causal assumptions. SEM allow exploratory modeling, meaning they are suited to theory development. The method is tested against the obtained measurement data to determine how well the model fits the data. Among the strengths of SEM is the ability to construct latent variables: variables which are not measured directly, but are estimated in the model from several measured variables. This allows the modeler to explicitly capture the unreliability of measurement in the model, which allows the structural relations between latent variables to be accurately estimated. RESULTS : The study results showed that causal factors could be grouped into 3. Factor 1 includes traffic variables, and Factor 2 contains turning traffic variables. Factor 3 consists of other road element variables such as speed limits or signal cycles. CONCLUSIONS : Non-linear regression models can be used to develop accident predictions models. However, they lack to estimate causal factors, because they select only few significant variables to raise the accuracy of the model performance. Compared to the regressions, SEM has merits to estimate causal factors affecting accidents, because it allows the structural relations between latent variables. Therefore, this study used SEM to estimate causal factors affecting accident at urban signalized intersections.

• Journal of the Institute of Electronics Engineers of Korea TC
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• v.48 no.10
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• pp.29-34
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• 2011

We present a network coding scheme which is designed for improving throughput in multi-hop wireless network with multi-radio multi-channel. The co-channel interference and unreliability of wireless transmissions cause the wireless network to reduce throughput. In wireless network, multi-radio multi-channel technology shows benefit to cut down channel interferences and contentions. And network coding can reduce the complexity of scheduling and improve throughput by increasing usage of links in wireless network. In this paper, we propose a method of channel assignment and transmission scheduling in intra-session network coding that efficiently improve throughput for multi-hop wireless network by using mathematical modeling and linear programming. Moreover, we evaluate the performance of the intra-session network coding scheme by using AMPL with CPLEX. The simulation results show that intra-session network coding can achieve better throughput than traditional routing.

• Journal of Technology Innovation
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• v.22 no.3
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• pp.287-310
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• 2014

Due to the toughening intelligence-based competitions among nations, it has become important to industrialize R&D results. To industrialize R&D results through technology transfer, the transfer fee between a technology developer and a company should be discussed. While discussing the transfer fee, the results of technology valuation have been used. However, due to the unreliability of its result, the technology transfer market has not been expanded. In this paper, we discuss the improvement of the reliability of the technology valuation method to expand the technology transfer market. The proposed scheme provides graph-type technology valuation results according to various industrial scenarios using objective technology and market data. With the use of the proposed scheme, the technology developer and the consumer (i.e., the company) can determine the appropriate technology transfer fee. Thus, the proposed scheme is expected to contribute to the expansion of the technology transfer market.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.6 no.6
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• pp.1496-1521
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• 2012

Uncertainty is ubiquitous in target tracking wireless sensor networks due to environmental noise, randomness of target mobility and other factors. Sensing results are always unreliable. This paper considers unreliability as it occurs in wireless sensor networks and its impact on target-tracking accuracy. Firstly, we map intersection pairwise sensors' uncertain boundaries, which divides the monitor area into faces. Each face has a unique signature vector. For each target localization, a sampling vector is built after multiple grouping samplings determine whether the RSS (Received Signal Strength) for a pairwise nodes' is ordinal or flipped. A Fault-Tolerant Target-Tracking (FTTT) strategy is proposed, which transforms the tracking problem into a vector matching process that increases the tracking flexibility and accuracy while reducing the influence of in-the-filed factors. In addition, a heuristic matching algorithm is introduced to reduce the computational complexity. The fault tolerance of FTTT is also discussed. An extension of FTTT is then proposed by quantifying the pairwise uncertainty to further enhance robustness. Results show FTTT is more flexible, more robust and more accurate than parallel approaches.

• Archives of Reconstructive Microsurgery
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• v.13 no.1
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• pp.24-28
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• 2004

The vascularity of a skin island in fibula osteocutaneous free flap often depends on musculocutaneous perforators that find their origin in the proximal peroneal artery. But a potential drawback has been reported on the unreliability of the skin paddle. The perforating vessels to the skin paddle of the fibula osteocutaneous free flap were rarely derived from a common tibio-fibula trunk, an anterior tibial artery and a posterior tibial artery. Previous studies have emphasized total loss of the overlying skin paddle, if the expected perforating vessels are not present. We report here on our experience that the skin paddle of the fibula osteocutaneous free flap was vascularized not by a peroneal artery but a direct branch of the posterior tibial artery. There were no intraseptal nor intramuscular pedicles in the posterior crural septum which connected to the overlying skin island. Therefore, we performed microsurgical anastomoses between distal peroneal vessels of the fibula and the perforating branches of the posterior tibial vessels of the skin paddle. The anastomosed skin paddle was salvaged with a peroneal flow through vascular anastomosis and was transferred to the bone and intraoral soft tissue defects with the fibula graft. The patient had no evidence of vascular compromise in the postoperative period and showed good healing of the intraoral skin flap.