• Journal of Yeungnam Medical Science
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• v.36 no.1
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• pp.16-19
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• 2019

Background: This study compared the following three endoscopic techniques used to treat bladder stones: transurethral cystoscope used with a pneumatic lithoclast or nephroscope used with a pneumatic lithoclast and nephroscope used with an ultrasonic lithoclast. Methods: Between January 2013 and May 2016, 107 patients with bladder stones underwent endoscopic treatment. Patients were classified into three groups based on the endoscopic techniques and energy modalities used in each group as: group 1 (transurethral stone removal using a cystoscope with pneumatic lithoclast), group 2 (transurethral stone removal using a nephroscope with pneumatic lithoclast), and group 3 (transurethral stone removal using a nephroscope with ultrasonic lithoclast). Baseline and perioperative data were retrospectively compared between three groups. Results: No statistically significant intergroup differences were observed in age, sex ratio, and stone size. A statistically significant intergroup difference was observed in the operation time-group 1, $71.3{\pm}46.6min$; group 2, $33.0{\pm}13.7min$; and group 3, $24.6{\pm}8.0min$. All patients showed complete stone clearance. The number of urethral entries was higher in group 1 than in the other groups. Significant complications did not occur in any patient. Conclusion: Nephroscopy scores over cystoscopy for the removal of bladder stones with respect to operation time. Ultrasonic lithoclast is a safe and efficacious modality that scores over a pneumatic lithoclast with respect to the operation time.

• Proceedings of the KSRS Conference
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• 2007.10a
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• pp.496-499
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• 2007

The COMS ground segment will operate the geostationary satellite continuously 24h/7days and deliver processed data to end-users with respect to the predefined schedule without delay. For reliable operation, each COMS ground center has internally dual-configuration for critical systems but impossible to every components. Any unexpected failure or regular maintenance to the single configured antenna system may lead the interruption of COMS service and operation. The natural disaster or external attack can destroy one ground center and the operation will be stopped. Therefore COMS program implements backup system remotely located in other centers. Even considering foreign geostationary systems, it's the best solution guaranteeing consistent system operation against internal failure or external disaster.

• Journal of the Korean Society of Tobacco Science
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• v.29 no.1
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• pp.41-51
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• 2007

This study was implemented to examine the effect of tobacco on operation of a retail store and propose a relevant direction to development of a retail store. In terms of an examination method, the questionnaire was conducted in respect of supermarkets and convenience stores(CVS) around the nation. As a result of analysis based on such questionnaire, although there was a little difference in between a supermarket and a convenience store, a similar result could be found in general. In other words, retailers selling tobacco regarded the tobacco as a medium to solicit customers. Since the significance of tobacco in terms of total sales volume was so high, without the tobacco, they might have suspend the business. Consequently, the effect of tobacco was enormous. In addition, under the premise that many regular customers should be acquired to develop such retail stores, it was found that it would be necessary to increase $15{\sim}20%$ in terms of a margin in tobacco, preserve the profit ratio by the government, make efforts to enhance a quality and design by a tobacco company, actively recommend a particular brand, and actively display a tobacco publicity booklet, etc. Moreover, the proper number of tobacco stores in comparison with habitual smokers was one per 200 persons. In respect of the most unreasonable tobacco policy, a minor-related system and a policy of increasing a tobacco price were named. Thus, under the premise that a medium such as tobacco is highly important with respect to an operation of retail store, it is necessary to pay a more careful attention to an improvement of a reasonable and equitable system to further develop a retail store.

• Proceedings of the Korean Institute of Intelligent Systems Conference
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• 1998.03a
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• pp.116-119
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• 1998

Abstract-In paper, an operation support software for combustion control of refuse incineration plant is developed using fuzzy model and genetic algorithm. It has two major modules which are simulation module and optimal operation module. In simulation module modelling is performed to obtain fuzzy model of the refuse incineration plant and obtained fuzzy model predicts outputs of the plant when inputs are given. This module can be used to obtain control strategy, and train and enhance operators' skill by simulating the plant. And in optimal operation module, genetic algorithm searches and finds out optimal control inputs over all possible solutions in respect to desired outputs. In order to testify proposed operation support software, computer simulation was carried out.

• Journal of the Korea Safety Management & Science
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• v.9 no.4
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• pp.39-47
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• 2007

An industrial injury prevention has a basis on fundamental spirit of human respect rather than only injury prevention in company. The employer should recognize employee as a core part of an industrial management and use as a starting point of safety and health management rather than means of production. There are many reason for unsafety action without safety operation. The reason is no standard safety operation in company or the workers never get a enough education. Standard safety operation is prepared by paper for accurate directions and orders and operators must read the paper to prevent an error of action. Also an essential particular is safety of equipment and machine must be assumed to establish standard safety operation then safety of operations will be possible.

• Journal of the Korean Mathematical Society
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• v.56 no.6
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• pp.1689-1701
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• 2019

Let ${\star}$ be a semistar operation on the integral domain D. In this paper, we prove that D is a $G-{\tilde{\star}}-GCD$ domain if and only if D[X] is a $G-{\star}_1-GCD$ domain if and only if the Nagata ring of D with respect to the semistar operation ${\tilde{\star}}$, $Na(D,{\star}_f)$ is a G-GCD domain if and only if $Na(D,{\star}_f)$ is a GCD domain, where ${\star}_1$ is the semistar operation on D[X] introduced by G. Picozza [12].

• The Pure and Applied Mathematics
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• v.11 no.1
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• pp.1-14
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• 2004

Due to the development of computer network and mobile communications, the security in image data and other related source are very important as in saving or transferring the commercial documents, medical data, and every private picture. Nonetheless, the conventional encryption algorithms are usually focusing on the word message. These methods are too complicated or complex in the respect of image data because they have much more amounts of information to represent. In this sense, we proposed an efficient secret symmetric stream type encryption algorithm which is based on Boolean matrix operation and the characteristic of image data.

• Journal of Korea Multimedia Society
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• v.19 no.6
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• pp.1014-1023
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• 2016

In this study, we presented a method for non-square Differential LBP operation that can well describe the micro pattern in the horizontal and vertical component. We proposed a way to represent a LBP operation with various direction components as well as the diagonal component. In order to verify the validity of the proposed operation, Differential LBP was investigated with respect to accuracy, sensitivity, and specificity for the classification of facial expression. In accuracy comparison proposed LBP operation obtains better results than Square LBP and LBP-CS operations. Also, Proposed Differential LBP gets better results than previous two methods in the sensitivity and specificity indicators 'Neutral', 'Happiness', 'Surprise', and 'Anger' and excellence Differential LBP was confirmed.

• Journal of the Korean Operations Research and Management Science Society
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• v.39 no.4
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• pp.153-165
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• 2014

We present a new framework for rental capacity management in which rental capacity is dynamically managed by means of temporary inventory addition/return. While serving customers with its own (native) capacity, the rental firm rents additional rental capacity from an upper echelon rental company so that it can avoid lost sales which may occur when stock is not sufficient, and returns it when stock becomes sufficiently large enough to cope with demands. Formulating the model as a Markov decision process, we investigate a flexible capacity addition/return policy that maximizes the firm's profit with respect to system costs. Numerical study indicates that rental operation with capacity addition/return can be economically favorable over rental operation without capacity expansion/return and can contribute the reduction in the size of native rental capacity.

• Nuclear Engineering and Technology
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• v.41 no.3
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• pp.237-246
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• 2009

Digitalization of not only non-safety but also safety-grade I &C systems with full computerized Main Control Room (MCR) is the recent trend of I&C systems of nuclear power plants (NPP) around the world, while plant maintenance has been shifting from traditional time based maintenance to condition based maintenance. In order to cope with the new trend of operation and maintenance in NPP, a concept of online distributed diagnostic system for both plant operation and maintenance has been proposed in order to further improve both the plant efficiency and the work environment of plant operation staff members by organizational learning. In this respect, the research subjects of human machine interface (HMI) for the online distributed diagnostic system are also discussed for supporting the plant personnel at both MCR and local working places in the plant by the application of advanced ICT (Information and Communication Technologies).