• Transactions of Materials Processing
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• v.10 no.1
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• pp.53-58
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• 2001

Set-up reference values, used in determining the optimum downcoiling tension, we experimentally verified in this study. During the actual downcoiling, the strip suffers both tension and bending force through the rotation of mandrel. Therefore, simulative test which can measure both tension and bending resistance of strip was performed to estimate set-up reference value for strip tension during downcoiling operations. The values obtained from the simulative test were correlated with the yield stress which has conventionally been used as reference values for downcoiling tension. The correlative analysis showed that the yield stress of strip can be a good reference value for downcoiling tension. Furthermore, the bending load also shows strong correlation with simulated values due to the close relationship between yield stress and bending load.

• 제어로봇시스템학회:학술대회논문집
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• 2003.10a
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• pp.1323-1326
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• 2003

In this paper, we propose set-up model of silicon steel cold rolling mill. Until now, the working of Silicon Steel is operated using the look-up table value of roll force which a field operator finds by making good use of his experience. Therefore, the standardization of data and an improvement of the quality on product are very difficult. So we establish neural model using field data of various kinds of coil at each pass.

• Journal of Korean Dental Science
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• v.2 no.2
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• pp.12-17
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• 2009

Purpose : To determine whether peri-implant crestal bone loss could be affected by systemic disease, primary ISQ value, implantation method (submerged vs. non-submerged), surface treatment, and bone density Materials and methods : Patients who underwent fixture installation from June 24, 2005 to October 23, 2008 at Seoul National University Bundang Hospital were evaluated. A total of 157 patients (male: 52, female: 85) had 346 fixtures installed. Among them, 49 patients had periapical radiographs taken 1 year after prostheses were first set. A total of 97 fixtures were implanted. In particular, 30 fixtures were installed in patients with systemic diseases such as diabetes mellitus, cardiovascular disease, hypertension, and liver disease. The immediate stability of implants was measured with $Osstell^{tm}$. Implant surface treatment was classified into two groups (RBM, Cellnest (Anodized)), and bone density, into four groups (D1~D4). The bone resorption on the mesial and distal areas of fixtures was measured with periapical radiographs using the paralleling technique, and the mean value was calculated. The length determination program in IMPAX (AGFA, Belgium) was used. Results : At least 332 out of 346 (96%) installed GS II implants were successfully osseointegrated 1 year after prostheses were first set. The mean value of the bone resorption of the installed GS II implants was 0.44mm. The minimum value was 0mm, and the maximum value, 2.85mm. There was a statistically significant difference between the implantation methods (submerged, non-submerged) with regard to the amount of alveolar bone loss 1 year after prostheses were first set (p<0.05). Non-submerged implants showed less crestal bone loss. Note, however, that other variables had no correlation with crestal bone loss (p>0.05). Conclusion : There was a statistically significant difference between the 1-stage method and 2-stage method with regard to the amount of alveolar bone loss 1 year after prostheses were first set. Systemic disease, primary ISQ value, surface treatment, and bone density were not associated with alveolar bone loss. Other variables were assumed to have a correlation with alveolar bone loss.

• Communications for Statistical Applications and Methods
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• v.6 no.1
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• pp.25-32
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• 1999

A single outlier can influence on the least squares estimators and can invalidate analysis based on these estimators. The Cook's statistic has been introduced to measure influence of individual data point on parameter estimation and the quantile of the F distribution is recommended as a reference value. but in practice subjective judgement is applied in the choice of appropriate quantile. A simple reference value is introduced in this paper which is developed by approximating conditional quantities of Cook's measure. The performance of the proposed criterion is evaluated through analysis of real data set.

• The Journal of Korean Society for Radiation Therapy
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• v.16 no.2
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• pp.1-8
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• 2004

Purpose : What confirm a patient's set-up precisely is an important factor in stereotactic radiosurgery Especially, the tumor is moved by respiration in case of lung cancer. So it is difficult to confirm a exact location by L-gram or EPID. I will verify a exact patient's set-up about this sort of problem by verification system(exactrac 3.0) Materials and Methods : The patient that had lung cancer operated on stereotactic radiosurgery is composed of 6 people. The 5 patients use an ABC tool and 1 patient doesn't use it. I got such a patient's L-gram and EPID image by Body frame(elekta, sweden), compared Ant. image with Lat. one, and then confirmed a set-up. I fused DRR image of CT and X-ray image of Verification system(exactrac 3.0) 3 dimensional, analyzed the coordinate value(vertical, longitudinal, lateral), and then confirmed a difference of existing method. Results : In case of L-gram and EPID, we judge an exact of the patient's set-up subjectively, and on we could treat the patient with radiation. As a result of using Verification system(exactrac 3.0), coordinate value(vertical, longitudinal, lateral) of patient's set-up was comprised within 5mm. We could estimate a difference of the coordinate value visually and objectively. Consequently, Verification system(exactrac 3.0) was useful in judging an exact patient's set-up. Conclusion : In case of Verification system(exactrac 3.0), we can confirm an exact patient's set-up at any time whenever, However, there are several kinds of the demerit. First, it is a complex process of confirmation than the existing process. Second, thickness of CT scan slice is within 3mm. The last, X-ray image has to have shown itself clearly. If we solve this problem. stereotactic radiosurgery will be useful in treating patients why we can confirm an exact patient's positioning easily.

• The Korean Journal of Financial Management
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• v.1 no.1
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• pp.1-27
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• 1985

One of the most important research works in modern business enterpise is the relation between the purpose of business enterprise and decision making behavior of manager. It is because the coincidence of the former and the latter is considered an ideal type in evaluating the result of business management. Here I have set up assumptions in order to solve the above statements: (1) What purpose does the modern business enterprise set up and what kind of economic background does it have? (2) What is the theory of maximization of stock value among the purposes of business enterprise? (3) What kind of decision making do we do in the maximization of stock value in busiess administration? (4) How is the behavior of business financial manager's intention and decision made? The result pursued under the above assumptions shows that business manager's behavior of decision making is affected according to the degree that he gets some information, but basically is determined in consideration of his autonomous standpoint, namely the stability of business enterprise and the stability of manager himself while he faithfully performs his duty which is entrusted by stockholders. Therefore we come to the conclusion that there is a little gap between a manager's behavior of decision-making and the purpose of stock value maximization.

• Journal of Korea Technology Innovation Society
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• v.5 no.2
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• pp.141-151
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• 2002

Many technology investment projects can be considered as set of sequential options. A compound real option can be used for evaluating sequential technology investment decisions under significant uncertainty and measuring its value. In this paper, the formula developed by Geske and Johnson(1984) and Buraschi and Dumas(2001) was applied to evaluate the technology investment with related double real option. Also double real option was com-pared with net present value method and multiple linear regression model was used to assess the partial effects of risk free rate and log-term volatility on its value.

• Proceedings of the KIEE Conference
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• 1999.07c
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• pp.1202-1204
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• 1999

This paper proposes a value-based pricing suitable for deregulation situation in electricity market, where the value is measured based on the service quality such as system reliability. The proposed approach makes it possible to maximize social welfare, in that diversified service can produce the optimal combination set of demand and supply. The proposed pricing can also be applied to a direct load control.

• Journal of Korea Game Society
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• v.14 no.6
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• pp.109-118
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• 2014

We studied the creation of fractal images with polygonal rotation symmetry. As in Loocke's method[13] we start with IFS of affine functions that create polygonal fractals and extends the IFS by adding functions that create Julia sets instead of adding square root functions. The resulting images are rotationally symmetric and Julia set shaped. Also we can improve fractal images by modifying probabilistic IFS algorithm, and we suggest a method of deforming Julia set by changing exponent value.

• Bulletin of the Korean Mathematical Society
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• v.52 no.5
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• pp.1423-1431
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• 2015

A clique-transversal set D of a graph G is a set of vertices of G such that D meets all cliques of G. The clique-transversal number is the minimum cardinality of a clique-transversal set in G. For every cubic graph with at most two bridges, we first show that it has a perfect matching which contains exactly one edge of each triangle of it; by the result, we determine the exact value of the clique-transversal number of line graph of it. Also, we present a sharp upper bound on the clique-transversal number of line graph of a cubic graph. Furthermore, we prove that the clique-transversal number of line graph of a triangle-free graph is at most the chromatic number of complement of the triangle-free graph.