• Proceedings of the Korean Society of Toxicology Conference
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• 2002.11b
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• pp.153-153
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• 2002

Methylmercury (MeHg), one of the heavy metal compound, can cause severe damage to the central nervous system in humans. Many reports have contributed MeHg poisoning to contaminated foods and release into the environment. Despite many studies on the pathogenesis of MeHg-induced central neuropathy, no useful mechanism of toxicity has been established.(omitted)

• The Journal of the Korea Contents Association
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• v.6 no.3
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• pp.75-84
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• 2006

The internet has the capabilities of supporting and facilitating several forms of consumer interaction including one-to-one, one to many, or many-to-many interactions. Especially, previous studies revealed that the Online Word-of-Mouth communication is widely used as a source of customer's information seeking and purchase decision making. Even with this importance of the Online Word-of-Mouth communication on internet, few research has systematically addressed the issue. This study investigates the effect of interpersonal communication on consumers' information search activities and develops a model that depicts the key antecedents and mediating variables of interpersonal communication in internet shopping environment. The results are as follows: First, choice uncertainty, perceived risk, and knowledge uncertainty play an important role for perceived usefulness. Second, perceived usefulness has directly affected interactive communication of consumers' communication style. Thus, it is essential for internet companies to find ways to encourage their customers to engage in word-of-mouth communication.

• Proceedings of the KIEE Conference
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• 2008.04b
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• pp.25-27
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• 2008

This paper discusses the implications of the MASTER SPEC project and its introduction to Korea in terms of social and political contexts. The motives for this report starts from both theoretical and empirical puzzles. Its theoretical motive is concerned to the right form of governance of electric-construction standardardization. Upon the experience of the United States and many European countries, we have acknowledged the role of government in the setting of industrial policy formats and standardization. However, the mechanisms of industrial governance have greatly changed these days, from the centralized one to the participatory one. We call the latter type governance. The form of governance implies the participation of both public and private actors in the policy-making of industrial matters. We have sought to find a better format in the case of electric-construction field. The answer is: the governance initiated by the private actors rather than the government-centered one. The project of MASTER SPEC, in this sense, has many probable implications toward the standard-setting of future industrial managements in Korea.

• Journal of the Korean Operations Research and Management Science Society
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• v.20 no.2
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• pp.61-76
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• 1995

The "optimal" solution for a decision making problem should be the one that best reflects the decision-maker's preference. For MADM (Multi-Attribute Decision-Making) problems, however, finding an optimal solution is difficult, especially when the number of alternatives, or that of attributes is relatively large. Most of the existing mathematical approaches arrive at a final solution on the basis of many unrealistic assumptions, without reflecting the decision-maker's preference structure exactly. To remedy this, some interactive methods have been proposed, but most of them require a large amount of information growing exponentially as the number of alternatives, or that of attributes increases. Therefore it is difficult for the decision-maker to maintain consistency throughout the decision making process. In this paper, an interactive method which finds optimal solutions for deterministic MADM problems with many attributes and alternatives is proposed. Instead of considering all the attributes simultaneously, this method partitions all the attributes into several mutually independent subgroups and considers one of them at each of preordered steps, where the alternatives are eliminated until the optimal one is obtained. The efficiency of the method lies in the fact that the amount of neccessary information is reduced significantly, and even further if a suboptimal solution is acceptable to the decision-maker.ion-maker.

• Communications for Statistical Applications and Methods
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• v.28 no.1
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• pp.59-79
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• 2021

Value at Risk (VaR) is one of the most common risk management tools in finance. Since a portfolio of several assets, rather than one asset portfolio, is advantageous in the risk diversification for investment, VaR for a portfolio of two or more assets is often used. In such cases, multivariate distributions of asset returns are considered to calculate VaR of the corresponding portfolio. Copulas are one way of generating a multivariate distribution by identifying the dependence structure of asset returns while allowing many different marginal distributions. However, they are used mainly for bivariate distributions and are not widely used in modeling joint distributions for many variables in finance. In this study, we would like to examine the performance of various copulas for high dimensional data and several different dependence structures. This paper compares copulas such as elliptical, vine, and hierarchical copulas in computing the VaR of portfolios to find appropriate copula functions in various dependence structures among asset return distributions. In the simulation studies under various dependence structures and real data analysis, the hierarchical Clayton copula shows the best performance in the VaR calculation using four assets. For marginal distributions of single asset returns, normal inverse Gaussian distribution was used to model asset return distributions, which are generally high-peaked and heavy-tailed.

• Journal of Institute of Control, Robotics and Systems
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• v.10 no.11
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• pp.1112-1118
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• 2004

Automated container terminals have been developed over the world years and many countries are interested in them because the amount of containers exported or imported is rapidly increasing. The conventional container terminals were not designed to handle this kind of heavily many containers. They would face many structural problems soon or later, although they have been managed to do well so far. One of the most important things in automated container terminal is the handing equipments able to transfer many containers efficiently. Those are maybe automated transfer cranes, automatic guided vehicles and automated quay-side cranes. The word 'automated' means the equipment is operated without drivers and those equipments are able to work without any interruption in working schedule. Through the researches on the conventional transfer cranes, we decided that the structure of conventional transfer cranes is not proper in automated container terminal and it is not possible to handle so many container in limited time. Therefore we have been studying on the proper structure of the automated container for past several years and a new type of transfer cranes has been developed. Design concept and control method of the new crane are introduced and experimental results are presented in this paper.his paper.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.13 no.8
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• pp.1705-1712
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• 2009

Recently, most Korean syntactic analysis systems use Dependency Grammar, because it is quite good to analysis of Korean language structures. But Dependency Grammar makes many ambiguities during syntax analysis of Korean. We implement a system which decreases many ambiguities in syntax analysis. To decrease ambiguities we suggest several methods. First, we use about 200 dependency rules, second, we suggest a new segmentation method and third, one predicate can not have more than one subject or object. Using these methods, we can reduce many ambiguities in Korean syntactic analysis.

• The Journal of Korean Medicine Ophthalmology and Otolaryngology and Dermatology
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• v.17 no.3
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• pp.167-173
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• 2004

Strabismus is a misalignment of the eyes. It is divided into paralytic strabismus and non-paralytic strabismus. There are so many causes in paralytic strabismus, and the oculomotor nerve palsy is one of them. Many studies reported the etiology and clinical features of oculomotor nerve palsy. Common causes of oculomotor nerve palsy are idiopathic, vascula.; disease, aneurysm, head trauma, neoplasm and miscellaneous. Recently the proportion of traumatic cause has been increased, but the treatment is difficult as it used to be. In this case report, one case of traumatic oculomotor nerve palsy with zygomatic arch Fx and clavicle Fx were treated by herbal medicine and acupuncture. After Treatment, symptoms- ptosis, deviation of Lt. eye to downward & outward in primary position, diplopia, limited adduction & elevation & depression, dilated pupil without pupil reflex- were improved. There are so many hypothesises but no definite guide lines are established about the oriental medical treatment of oculomotor nerve palsy, so we expect the establishment of definite guide lines by further clinical studies.

• Proceedings of the Korean Institute of IIIuminating and Electrical Installation Engineers Conference
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• 2003.11a
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• pp.283-288
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• 2003

This paper presents the result of survey of case study for Harmonics in electrical Installations of buildings. Recently, many power electronic equipments(power converter, computers, air conditioners electronic ballasts for fluorescent lamps and so on) are used in office buildings, and harmonic current from them influence the other equipments in a distribution line. Notably, voltage distortion or voltage harmonics may approach or exceed is allowable level in power distribution system. Individual electric power consumers and end-users and responsible for reducing current harmonics while companies or utilities are responsible for reducing voltage harmonics at the point of common coupling in distribution system. As for harmonics, which one of the electric power qualities, it becomes important to obtain harmonic voltage/current distribution of the power system precisely because the use of power electronic apparatus in increasing. However, there are some difficulties on evaluating the measured data in comparison with the simulated result. The primary cause was indentitied with the resonance of harmonics form many sources. To suppress harmonics in electrical installations of buildings, one of many methods suggest that resonance frequencies are controlled by modulating the capacities of high-voltage customer's capacitors.

• Journal of the Korea Society of Computer and Information
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• v.16 no.11
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• pp.163-171
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• 2011

Because RFID systems use radio frequency, they have many security problems such as eavesdropping, location tracking, spoofing attack and replay attack. So, many mutual authentication protocols and cryptography methods for RFID systems have been proposed in order to solve security problems, but previous proposed protocols using AES(Advanced Encryption Standard) have fixed key problem and security problems. In this paper, we analyze security of proposed protocols and propose our protocol using OTP(One-Time Pad) and AES to solve security problems and to reduce hardware overhead and operation. Our protocol encrypts data transferred between RFID reader and tag, and accomplishes mutual authentication by one time random number to generate in RFID reader. In addition, this paper presents that our protocol has higher security and efficiency in computation volume and process than researched protocols and S.Oh's Protocol. Therefore, our protocol is secure against various attacks and suitable for lightweight RFID tag system.