• Korean Business Review
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• v.16
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• pp.169-184
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• 2003

IR(Investor Relation) is an active management activity to provide well balanced information to investors which can reduce asymmetry of information between investors and management. This activity could contribute to the long-term development of corporation with increased mutual trust between investors and management. Consequently, in these days, ill is widely recognized as an effective measure of securing corporate transparency, maximization corporate value, and stock-holder oriented management. The purpose of this study is to examine the effect of corporate IR activity on investment behavior as well as stock price. It is assumed that if asymmetry of information between investors and management is cured by active ill activity from a corporation, with more transparent and reliable information of the firm at hand investors would more actively involved in trading. Statistically speaking, I assumed that the more information provided by ill activities, the higher value of a corporation at the stock trading.

• Progress in Medical Physics
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• v.26 no.1
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• pp.18-27
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• 2015

Since a Compton camera has high detection sensitivity due to electronic collimation and a good energy resolution, it is a potential imaging system for nuclear medicine. In this study, we investigated the feasibility of a Compton camera for multi-tracer imaging and proposed a rotating Compton camera to satisfy Orlov's condition for 3D imaging. Two software phantoms of 140 and 511 keV radiation sources were used for Monte-Carlo simulation and then the simulation data were reconstructed by listmode ordered subset expectation maximization to evaluate the capability of multi-tracer imaging in a Compton camera. And the Compton camera rotating around the object was proposed and tested with different rotation angle steps for improving the limited coverage of the fixed conventional Compton camera over the field-of-view in terms of histogram of angles in spherical coordinates. The simulation data showed the separate 140 and 511 keV images from simultaneous multi-tracer detection in both 2D and 3D imaging and the number of valid projection lines on the conical surfaces was inversely proportional to the decrease of rotation angle. Considering computation load and proper number of projection lines on the conical surface, the rotation angle of 30 degree was sufficient for 3D imaging of the Compton camera in terms of 26 min of computation time and 5 million of detected event number and the increased detection time can be solved with multiple Compton camera system. The Compton camera proposed in this study can be effective system for multi-tracer imaging and is a potential system for development of various disease diagnosis and therapy approaches.

• Proceedings of the Korean Institute Of Construction Engineering and Management
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• 2006.11a
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• pp.597-601
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• 2006

There are considerable amount of man power and time spent for analysis and selection of various materials due to the inadequate application system and rapid searching process of material related information in each stage of building production process. Also, due to the insufficiency in recycling system of important information created for each process, they are hoarded at each task stage and project completion. As a result, because of the repetition of the similar/identical tasks on each process, it is the major reason for impeding the efficient employment of manpower of the company and decreasing competition of the company. Moreover, in selecting finish material in the project field, there are many difficulties due to the lack of technical information such as product characteristics and field applications. The construction quality also affects the profit and loss of the product which calls for a need to develop continued information management system that the finish material related examples could be shared in real time. The objective of this study is to propose a building finish material information which the real time research and application is possible to raise the productivity. TO do this, the current material information task status analysis and questionnaire research should be conducted to understand the demand of system development and reflect the result onto the system for easy access and application. Therefore, the building finish material information system for enhancement of productivity of construction task proposed in this study is expected to be utilized in enhancement of construction quality, maximization of company profit, and strengthening of company competition.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.17 no.7
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• pp.1589-1596
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• 2013

Recently, spectral efficiency or reliability is required to be improved in the scenario of multiple access. In this paper, we consider a scenario where two source nodes access one destination node. Different with conventional multiple access studies, in our research, a part of the allocated resource is shared by two source nodes and this scheme is called partial multiplexing. Let $R_s$ denote the ratio of the amount of the shared resource to that of the resource allocated to each user. We analyze and optimize the performance of the partial multiplexing in term of $R_s$. We show that the optimal $R_s$ to maximize the throughput is 1 or 0 based on approximated bit error rate (BER). In addition, if we set a constraint on frame error rate (FER), $R_s$ can have a value between 0 and 1. We also find the approximated $R_s$ to meet the constraint as a closed form. Partial multiplexing can be a novel multiple access scheme.

• Herbal Formula Science
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• v.13 no.2
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• pp.141-151
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• 2005

From the tuberous root of Aconitum carmichaeli Debx.(Ranunculaceae), the main root is called as common monkhood mother root and the later root is called as the prepared aconite root. From the prepared aconite root. Looking at the processing method of the prepared aconite root, it is divided into Yeombuja (prepared aconite root processed in salt) and heuksoonpyeon (baekbupyeon) following the processing method after removing the soil and this is a way of processing the prepared aconite root without damage it. The recently produced raw prepared aconite root is easily damaged, thus it shall be preserved in salt to have the crystal shape on the surface of the prepared aconite root and store and transport in firmly solidified yeombuja condition. Therefore, yeombuja shall remove the salt before use and requires processing for use but heuksoonpyeon or baekbupyeon may use immediately. For the succession of the unique processing techniques of our ancestors, there has to be studies on the techniques. Prepared aconite root is generally used as holy medicines to cure the yang depletion syndrome, kidney-yang deficiency syndrome, and obstruction of qi in the chest syndrome. However, they are the substances with toxicity. It is contemplated that the contents of processing are broadly understood through the document on the processing method, and based on such foundation, the systematic set and proof on the documents are made along with the addition of the contemporary scientific theory and technology to develop the traditional processing technology to maximize the treatment effect and safety of prepared aconite root. In this study, the historic data and records on the processing method of latteral root of aconitum carmichaeli Debx will be rearranged to contribute to the standardization of medicinal herbs, maximization of efficacy and minimization of the side effects.

• The Korean Journal of Financial Management
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• v.26 no.4
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• pp.1-34
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• 2009

We test the effect of corporate cash holdings on firm value by using the KOSPI listed firms over the period between 2002 and 2007 from the agency theories perspective, which has not been the central interest of prior studies. Unlike existing studies, using the manager's ownership ratio or foreign investor's shareholder ratio as a proxy variable for agency costs, we use the individual firm's corporate governance scores by the KCGS to test the effect of agency costs on the value of firm's cash holdings. We find that a firm value is positively related with its cash holdings. We also find that a firm with good corporate governance tends to experience a higher value of its cash holdings, compared with a firm with bad corporate governance. These results are consistent even after controlling for the endogeneity problems between corporate governance and firm value, strongly supporting the agency theory of cash holdings. Therefore, a firm's cash holdings, even from liquidity or precautionary motives, could increase the firm cash value, as long as its managers' interest is shareholders' wealth maximization rather than their private benefits.

• Journal of Distribution Science
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• v.13 no.10
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• pp.109-114
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• 2015

Purpose - The movie market has the characteristics of being a perfectly competitive market as well as a pure monopolistic market at the same time. This is because there are competitors in the industry but prices, although not fixed, have not changed a lot. Price competition may not have spread, but the competition is focused on artistic value, and the degree of box office success is most important. The artistic value is determined in the course of the production process. However, the degree of box office success is dependent upon the marketing manager. The marketing strategy represents the difference in the standard or quality of the movie. Inherently, the marketing manager adopts the entertainment strategy based on the quality of the foundation of the completed movie. At this time, the marketing manager knows the pertinent information (high quality/low quality) regarding the movie. This research study tries to reveal what should be the reasonable movie marketing expense, dependent on the quality of the movie. Research design, data, and methodology - Using a game scenario with different market players, the goal of the research analysis is to find out the following. First, the marketing expense is determined to maximize the profits after film production. Second, after the production costs are already committed, the manufacturer gets to choose the marketing level. At this time, there will be a profit maximization point, considering the competition. The premise of the research is as follows: if it is a good movie of quality, positive word of mouth increasing the audience continuously slows down the speed of the demand curve. If the movie quality is bad, the negative word of mouth decreasing the audience gradually hastens the speed of the demand curve. On the marketing side, when the manufacturer invests heavily in the marketing expense of the movie, consumer expectations increase to drive up the audience numbers. On the other hand, it is difficult to improve the profits excessively. When the manufacturer invests in marketing a little bit, the marketing expense is only relatively committed, therefore a lot of demand cannot be gained. Results - If a fixed market share is in a competitive situation, a low quality manufacturer expends relatively more marketing expense. If the situation assumes two manufacturers spend the same for the cost of production, the high quality manufacturer takes more profit. If the manufacturer expends less marketing budget to save costs, the optimum profit cannot be achieved since the other party (opponent) grabs the initial market share. Conclusions - In conclusion, investment is essential for market share to increase. We must refrain from a zero-sum game and have models where the game participants pursue the creative profits together. In the current film industry, there is the dominating logic of winner and loser but we have to create a film industry environment where the participants can be altogether satisfied and live together.

• Journal of the Korean Association of Geographic Information Studies
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• v.11 no.2
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• pp.85-92
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• 2008

This study, the one concerning the evaluation analysis of the function of the wind generation using KLAM_21, has examined closely how the wind really flows on the space of the city, working with the object of case location. In the first place, the cold air formed at upper stream of Sincheon river, a ravine of whole area of Gachang gully and an inclined plane of neighboring mountainous district, flows to the north and expands itself along the upper stream of the Sincheon river, and as the time passes, it is tending upwards in the change of the volume and height as well as of the velocity and direction, of the cold air. It was learned that this phenomenon has made it clear that the spatial features of this area give rise to very good condition in generating and flowing the cold air. Meanwhile, it has been shown that in the area of park in the Ap-mountain, the generation and flow of the cold air are much interrupted because of the overpass traversing the whole area of the park of Ap-mountain, the congested area of large-scaled apartments and the urban development activities constructing the building in the park, and the volume and height of the cold air has been grown very small. In conclusion, It has been learned that for maximization of the spatial effect of the wind corridor, the areas where the cold air is generated, flowed, accumulated, and maintained, have to be connected spatially, and this spatial connection has a close relation with spatial features of the area.

• The Korean Journal of Applied Statistics
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• v.33 no.3
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• pp.281-296
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• 2020

Repeated outcomes from the same subjects are referred to as longitudinal data. Analysis of the data requires different methods unlike cross-sectional data analysis. It is important to model the covariance matrix because the correlation between the repeated outcomes must be considered when estimating the effects of covariates on the mean response. However, the modeling of the covariance matrix is tricky because there are many parameters to be estimated, and the estimated covariance matrix should be positive definite. In this paper, we consider analysis of multivariate longitudinal data via two modeling methodologies for the covariance matrix for multivariate longitudinal data. Both methods describe serial correlations of multivariate longitudinal outcomes using a modified Cholesky decomposition. However, the two methods consider different decompositions to explain the correlation between simultaneous responses. The first method uses enhanced linear covariance models so that the covariance matrix satisfies a positive definiteness condition; in addition, and principal component analysis and maximization-minimization algorithm (MM algorithm) were used to estimate model parameters. The second method considers variance-correlation decomposition and hypersphere decomposition to model covariance matrix. Simulations are used to compare the performance of the two methodologies.

• Journal of Life Science
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• v.25 no.1
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• pp.84-92
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• 2015

Interferon inducible transmembrane protein (IFITM) family genes have been implicated in various cellular processes such as the homotypic cell adhesion functions of IFNs and cellular anti-proliferative activities. The present study aimed to investigate whether the polymorphisms of the IFITM2 and IFITM5 genes are associated with susceptibility to UC. We identified a total of thirteen polymorphisms (eleven SNPs and two variations) in the IFITM2 gene and twelve polymorphisms (eleven SNPs and one variation) in the IFITM5 gene, by the direct sequencing method. Genotype analysis in the IFITM2 and IFITM5 SNPs was performed by polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) and Taq-Man probe analysis, and the haplotype frequencies of IFITM2 and IFITM5 SNPs for multiple loci were estimated using the expectation maximization (EM) algorithm. The genotype and allele frequencies of IFITM2 SNPs, as well as IFITM5 SNPs, in UC patients were not significantly different from those of the healthy controls. We also analyzed the combined frequencies of rs77537847 of IFITM1, rs909097 of IFITM2, and rs56069858 of IFITM5 in the UC patients and the healthy controls. Although the distribution of the major combined genotype frequency did not differ significantly between the healthy controls and the UC patients, the GGT combined frequency in the healthy controls was significantly different from that in the UC patients (P=0.002). This result suggests that the combined genotype of the IFITMs polymorphisms may be associated with a susceptibility to UC and could be a useful genetic marker for UC.