• KSII Transactions on Internet and Information Systems (TIIS)
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• 제7권5호
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• pp.967-979
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• 2013

Now a day, Wireless Sensor Networks (WSNs) are being widely used in different areas one of which is healthcare services. A wireless medical sensor network senses patient's vital physiological signs through medical sensor-nodes deployed on patient's body area; and transmits these signals to devices of registered medical professionals. These sensor-nodes have low computational power and limited storage capacity. Moreover, the wireless nature of technology attracts malicious minds. Thus, proper user authentication is a prime concern before granting access to patient's sensitive and private data. Recently, P. Kumar et al. claimed to propose a strong authentication protocol for healthcare using Wireless Medical Sensor Networks (WMSN). However, we find that P. Kumar et al.'s scheme is flawed with a number of security pitfalls. Information stored inside smart card, if extracted, is enough to deceive a valid user. Adversary can not only access patient's physiological data on behalf of a valid user without knowing actual password, can also send fake/irrelevant information about patient by playing role of medical sensor-node. Besides, adversary can guess a user's password and is able to compute the session key shared between user and medical sensor-nodes. Thus, the scheme looses message confidentiality. Additionally, the scheme fails to resist insider attack and lacks user anonymity.

• Journal of Fisheries and Marine Sciences Education
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• 제27권5호
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• pp.1436-1446
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• 2015

This study aims to understand how scuba diving instructors' expertise, instructor reliability and instruction efficiency are related to each other. In order to achieve the research goal, the study used a multi-stage stratified cluster sampling method and collected valid samples from 400 individuals at age of 20 and older who were scuba diving in scuba diving clubs in Busan, Gyeongnam, Gyeongbuk, Jeonnam and Jeonbuk. The 400 valid samples were applied to the data analysis. The study used SPSS 21.0 for processing the gathered data via a frequency analysis, a reliability analysis and a correlation analysis and in order to verify the hypotheses, the study applied AMOS 21.0 and conducted a confirmatory factor analysis and a structure equation model analysis. Findings that the study had extracted are summarized as follows. First, the study confirmed that the scuba diving instructors' expertise has a positive effect on the instructor reliability. Second, the scuba diving instructors' expertise was reported to positively influence the instruction efficiency. Third, the results revealed that the scuba diving club members' reliability in the instructors has a positive influence on the instruction efficiency.

• Journal of Computing Science and Engineering
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• 제1권1호
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• pp.95-123
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• 2007

Existing systems that support semistructured views do not maintain semantics during the process of designing the views. Thus, these systems do not guarantee the validity and reversibility of the views. In this paper, we propose an approach to address the issue of valid and reversible semistructured views, We design a set of view operators for designing semistructured views. These operators are select, drop, join and swap. For each operator, we develop a complete set of rules to maintain the semantics of the views. In particular, we maintain the evolution and integrity of relationships once an operator is applied. We also examine the reversible view problem under our operators and develop rules to guarantee that the designed views are reversible. Finally, we examine the changes in the participation constraints of relationship types during the view design process, and develop rules to ensure the correctness of the participation constraints.

• The Transactions of the Korea Information Processing Society
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• 제5권6호
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• pp.1418-1430
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• 1998

Temporal databases support an efficient historical management by means of valid time and transaction time. Valid time stands for the time when a data happens in the real world. And transaction time stands for the time when a data is stored in the database, Temporal Query Processing System(TQPS) should be extended so as tc process the temporal operations for the historical informations in the user query as well as the conventional relational operations. In this paper, the extended temporal query processing systems which is based on the previous temporal query processing system for TQuel(Temporal Query Language) consists of the temporal syntax analyzer, temporal semantic analyzer, temporal code generator, and temporal interpreter is to be described, The algorithm for additional functions such as transaction time management, temporal aggregates, temporal views, temporal joins and the heuristic optimization functions and their example how to be processed is shown.

• Journal of Information Technology Applications and Management
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• 제22권2호
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• pp.201-217
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• 2015

In this paper, we report computational testing result to examine the validity of firm's bankruptcy risk estimation through quantification of supply chain risk. Supply chain risk in this study refers to upstream supply risk and downstream demand risk, To assess the firm's risk affected by supply chain risk, we adopt unit of analysis as industry level. since supply and demand relationships of the firm could be generalized by the industry input-output table and the availability of various valid economic indicators which are chronologically calculated. The research model to estimate firm's risk level is the linear regression model to assess the industry bankruptcy risk estimation of the focal firm's industry with the independent variables which could quantitatively reflect demand and supply risk of the industry. The publicly announced macro economic indicators are selected as the candidate independent variables and validated through empirical testing. To validate our approach, in this paper, we confined our research scope to steel industry sector and its related industry sectors, and implemented the research model. The empirical testing results provide useful insights to further refine the research model as the valid forecasting mechanism to capture firm's future risk estimation more accurately by adopting supply chain industry risk aspect, in conjunction with firm's financial and other managerial factors.

• Journal of Technologic Dentistry
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• 제33권4호
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• pp.427-440
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• 2011

Purpose: The following research analyzes the causes of major selection and career decision of students studying dental technology. It is to be used as basic data for the management of career improvement program. Methods: The survey has been processed to 490 college students studying Dental Technology in D-college. Questionnaire consists of major selection confidence sheet (14 items) and career decision confidence sheet (18 items) and was scored with 5-points per question. The collected data was analyzed by the statistical program: SAS V8 for Windows. To test for significance on each item, p < 0.05 has been decided as a standard. Results: The analysis of result about the level of confidence on major selection has valid difference by genders, serving military service or not, experience of studying one more year to enter the college or not, making career decision and grade. The analysis of result about career decision has valid difference by gender, serving military service, career decision, day and night course, age and native place. Conclusion: We develop the career advice program and manage it effectively, the confidence on the major selection and pride about its faculty will be high to dental technology students.

• Journal of Distribution Science
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• 제12권9호
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• pp.95-99
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• 2014

Purpose - This study aims to develop and empirically test a multi-dimensional service convenience scale with the dimensions and measurement items of service convenience perceived by Korean consumers in retail contexts. Research design, data, and methodology - The study adopts the framework suggested by Berry et al. (2002) and conceptualizes service convenience as a second-order reflective construct comprising 31 items. Three department store chains (Hyundai, Lotte, and Shinsegae) and three discount store chains (E-mart, Homeplus, and Lotte Mart) were involved 510 valid responses were used for the empirical testing. Results - The measurement model is acceptable for internal consistency, convergent validity, and discriminant validity. Further, the structural model results show that service convenience is positively related to satisfaction. Results of the rival model comparison indicate that the proposed second-order factor model provides a better fit to the data than both the five-factor and the one-factor model. Conclusions - The multi-dimensional, second-order conceptualization of service convenience is robustly supported. This study provides psychometrically valid scales to measure service convenience in retail contexts as conceptualized by Berry et al. (2002).

• Korean Journal of Fisheries and Aquatic Sciences
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• 제49권6호
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• pp.838-844
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• 2016

In this study, epidemiological cut-off values were estimated for 44 Photobacterium damselae isolates, since clinical breakpoints have not been established for this pathogenic bacterium. The susceptibility of the isolates to 10 antibiotics was evaluated using internationally standardized disc diffusion protocols. Normalized resistance interpretation was used to generate statistically valid epidemiological cut-off values for the susceptibility data. There were not enough strains exhibiting full sensitivity to ampicillin and amoxicillin to allow analysis of these antibiotics. Because there were only a marginally sufficient number of strains exhibiting full sensitivity to oxytetracycline, the cut-off value generated provided only a provisional estimate. The valid wild-type cut-off values were <13, 13, 9, 22, 25, 27, and 28 mm for gentamicin, cephalexin, erythromycin, oxolinic acid, flumequine, florfenicol, and sulfamethoxazole/trimethoprim, respectively. The application of these cut-off values should greatly facilitate the rational selection of antibiotics for use in commercial fish farms.

• Journal of the Korean Data and Information Science Society
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• 제17권2호
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• pp.657-659
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• 2006

This note gives a counterexample showing that a main theorem of Aytal and Pehliven's (Information Sciences 176 (2006) 734-744) result on statically monotonic and bounded sequences of fuzzy numbers is not valid.

• Journal of Korean Society of Transportation
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• 제1권1호
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• pp.43-47
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• 1983

Within the conventional transportation planning process, "trip distribution" has a significant role to play. The most widely applied trip distribution model is the gravity model, for which Wilson provided the theoretical basis in 1967. The concept of the gravity model, however, still remains ambiguous if we analyze the "trip distribution" with a disaggregate data set. Thus, this paper hypothesizes that the gravity technique is still valid even with the disaggregate data set, by proving that the estimated coefficients of the gravity model, which is derived under the principle of entropy maximization, are identical with those of the multinomial logit model, which is derived under the principle of individual utility maximization.tility maximization.