• The Bulletin of The Korean Astronomical Society
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• 제36권2호
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• pp.64-64
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• 2011

We present a new quasi-stellar object (QSO) selection algorithm using a Support Vector Machine, a supervised classification method, on a set of extracted time series features including period, amplitude, color, and autocorrelation value. We train a model that separates QSOs from variable stars, non-variable stars, and microlensing events using 58 known QSOs, 1629 variable stars, and 4288 non-variables in the MAssive Compact Halo Object (MACHO) database as a training set. To estimate the efficiency and the accuracy of the model, we perform a cross-validation test using the training set. The test shows that the model correctly identifies ~80% of known QSOs with a 25% false-positive rate. The majority of the false positives are Be stars. We applied the trained model to the MACHO Large Magellanic Cloud (LMC) data set, which consists of 40 million lightcurves, and found 1620 QSO candidates. During the selection, none of the 33,242 known MACHO variables were misclassified as QSO candidates. In order to estimate the true false-positive rate, we crossmatched the candidates with astronomical catalogs including the Spitzer Surveying the Agents of a Galaxy's Evolution (SAGE) LMC catalog and a few X-ray catalogs. The results further suggest that the majority of the candidates, more than 70%, are QSOs.

• Korean Journal of Radiology
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• 제22권4호
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• pp.535-546
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• 2021

Objective: To evaluate the feasibility of texture analysis on non-contrast-enhanced T1 maps of cardiac magnetic resonance (CMR) imaging for the diagnosis of myocardial injury in acute myocardial infarction (MI). Materials and Methods: This study included 68 patients (57 males and 11 females; mean age, 55.7 ± 10.5 years) with acute ST-segment-elevation MI who had undergone 3T CMR after a percutaneous coronary intervention. Forty patients of them also underwent a 6-month follow-up CMR. The CMR protocol included T2-weighted imaging, T1 mapping, rest first-pass perfusion, and late gadolinium enhancement. Radiomics features were extracted from the T1 maps using open-source software. Radiomics signatures were constructed with the selected strongest features to evaluate the myocardial injury severity and predict the recovery of left ventricular (LV) longitudinal systolic myocardial contractility. Results: A total of 1088 segments of the acute CMR images were analyzed; 103 (9.5%) segments showed microvascular obstruction (MVO), and 557 (51.2%) segments showed MI. A total of 640 segments were included in the 6-month follow-up analysis, of which 160 (25.0%) segments showed favorable recovery of LV longitudinal systolic myocardial contractility. Combined radiomics signature and T1 values resulted in a higher diagnostic performance for MVO compared to T1 values alone (area under the curve [AUC] in the training set; 0.88, 0.72, p = 0.031: AUC in the test set; 0.86, 0.71, p = 0.002). Combined radiomics signature and T1 values also provided a higher predictive value for LV longitudinal systolic myocardial contractility recovery compared to T1 values (AUC in the training set; 0.76, 0.55, p < 0.001: AUC in the test set; 0.77, 0.60, p < 0.001). Conclusion: The combination of radiomics of non-contrast-enhanced T1 mapping and T1 values could provide higher diagnostic accuracy for MVO. Radiomics also provides incremental value in the prediction of LV longitudinal systolic myocardial contractility at six months.

• Journal of Nutrition and Health
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• 제31권9호
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• pp.1508-1521
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• 1998

The purpose of this study was to analyze and evaluate the menu served in business & industry contract foodservice by assessing nutritional value and by using menu-engineering technique from managers' view point. CAN-Pro program and Kasavana k Smith's Menu Engineering technique were used to evaluate the nutritional value and menu analysis, respectively. The data were analyzed using the SAS package program for descriptive analysis, t-test, ANOVA, and Pearson Correlation Analysis. As the result of nutritional value of lunch menu, all nutrient contents per meal were higher than a third of Korean recommended dietary allowances(RDA), But there was no problem when 20∼30% of plate waste was considered. Carbohydrate : Protein fat ratio was 62.7 : 16.4 : 20.8. Because animal : vegetable source ratios of protein, fat, calcium, iron were 44 : 56, 42 : 58, 22 : 78, 24 : 76, respectively, animal sources of calcium and iron needed to be supplemented. Plural set menus of A site were classified as STAR, PUZZLE, PLOWHORSE, DOG by Menu engineering technique. Set menus and soups & pot-stews among cafeteria menus in C site were operated properly without DOG and PUZZLE item. Side dishes of fishes, meats 8t eggs among cafeteria menus in C site were, for the most part, classified as STAR item, and side dishes of vegetables & salads and noodles among cafeteria menus in C site were STAR, PUZZLE, and DOG items. (Korean J Nutrition 31(9) : 1508-1521, 1998)

• Journal of the Korean Society of Clothing and Textiles
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• 제27권8호
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• pp.1004-1013
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• 2003

This study addressed an ill-understood issue of a price response model and a monopolistic price interval of fashion goods. The concept of monopolistic price interval introduced by Gutenberg has been rarely applied to the fashion goods, which is known as price sensitive goods. Thus, this study examined the price insensitive zone of the blue jean. The data of 268 respondents were analyzed using Choice-based Conjoint (CBC) analysis and t-test. Considering brand consideration set as a price determinant, we found the presence of monopolistic price interval of the jean. The results obtained from the CBC analysis showed that the bigger the size of brand consideration set, the shorter the monopolistic interval. This implied that the consumer who had a small brand consideration set was more likely to have a longer monopolistic price interval than the one who had a large brand consideration set, since the consumer with a small consideration set tended to value brand itself more than price. Although significant monopolistic price intervals were shown only for the three jean brands out of the seven, to reduce the size of brand consideration set and to increase brand loyalty were found important in maximizing firms'financial profits.

• Journal of IKEEE
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• 제13권2호
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• pp.220-223
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• 2009

A simple measurement system is built to estimate the dual-antenna diversity gain at 2.4GHz easily in open lab environment. To obtain multipath fading propagation channel, the system consists of two transmission horn that placed on opposite direction and a rotating stage mechanically changing the position of test dual-antenna with time over distance greater than one wavelength. Estimated diversity is nearly same as theoretical value such that measured diversity gain of 30mm separated is about 6dB similar to theoretical value of 5.7dB and increases monotonically with the increasing separation distance as predicted by the theory. Proposed measurement system that is simple enough to fit in a small space can evaluate the performance of various dual-antennas with a reasonable accuracy with lower 5% difference between the ten sets of measured waveform distribution and theoretical Rayleigh cumulative distribution.

• Journal of the Korean Society for Precision Engineering
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• 제23권2호
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• pp.65-72
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• 2006

Downcoiler is one of the major facilities in hot strip mill operation. The key to good coiling is having good equipment, modem control systems, excellent maintenance and an understanding of coiling process. Therefore, this study aims to develop a program that is useful for calculating machine design parameters and simulating coiling process. In this study, the pinching and coiling mechanism of the downcoiler was thoroughly studied and some of operational factors and their effects on the coiling process were investigated. The software was developed to estimate engineering parameters for coiler component design and to determine optimal setting values for successful coiling operation. In order to check the accuracy and usefulness of the developed software, the simulation of the downcoiler in $\#2$ Hot Strip Mill in Pohang Works was performed. The simulation results suggested that the set-up value for unit tension could be lowered. Test coiling operation by using the lowered set-up value for unit tension resulted in much more successful coiling in the aspect of strip quality and power consumption.

• Korean Journal of Food Science and Technology
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• 제31권4호
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• pp.977-983
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• 1999

This study was conducted to investigate the effects of emulsifiers on the quality of steamed bread. initial pasting temperature of the flour was decreased from $63.8^{\circ}C$ to $59.40{\sim}62.95^{\circ}C$ by adding 1% of emulsifiers such as monoglyceride, lecithin, sugar ester and diacetyl tartaric acid esters of mono- and diglycerides (DATEM). But other rheological properties of the doughs were varied with different emulsifiers. Flour with 1% sugar ester showed the lowest value of final viscosity and set back, therefore sugar ester might be effective for retard the retrogradation of bread. By alveogram test, flour with 1% DATEM showed the highest value of P (tenacity) but the lowest value of L (extensibility), that means DATEM might be effective for strengthening tenacity of dough but it lowered extensibility. After 72 hours of storage test, the steamed bread based on the flour with 1% monoglyceride showed the best crumb softness and the highest score of sensory test.

• Journal of Distribution Science
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• 제14권5호
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• pp.27-37
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• 2016

Purpose - Prior theories expect a lower marginal value of cash for weak governance firms. To test this hypothesis, we examine the relationship between corporate governance structures and marginal cash values in Korean retail firms. Research design, data, and methodology - We estimate marginal cash values based on the model of Faulkender & Wang (2006). The retail firms listed in Korean Stock Exchange from 2005 to 2013 are analyzed. Corporate governance scores are provided by Korean Corporate Governance Services. Results - We show a higher marginal value of cash for the weak governance retail firms in terms of total governance score. Our analysis on a detailed set of governance scores generally confirms this tendency. Yet, a higher marginal cash value is obtained for the firms with better board structures and dividend policies. Conclusions - Our findings argue against the agency view of cash policy predicting a negative relationship between corporate governance scores and marginal cash values. A low marginal value of cash, widely observed in the sample firms, also supports severe resource diversion problem in Korean corporations.

• Journal of the Korean Society of Clothing and Textiles
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• 제21권3호
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• pp.524-535
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• 1997

The purpose of this study was to find out the clothing values and meanings by material values. The researcher used the scales of Richins & Dawson (1992) for Materialism Scale. The scales of Prentice (1987) and Ricllins (1994a, 1994b) for privateand public meanings of clothing. The scales of Prentice (1987) and Richins (1994a, 1994b) for importance clothes of private and public meanings.. The scales of Creekmore (1968) for clothing values. The subjects of this study were 154 girl students in the university. The research materials was analyzed by Frequency, MANOVA and Scheffe test The results of this study were as follows; 1) Higher group of material values had an orientation that emphasizes enjoyment values of clothing in private moaning and seems expensive of clothing in public meaning. 2) All group set a high value on both suits and jeans in clothing of private meanie that meant both interpersonal and enjoyment values and put much worth on both suits and mustang that concerned both costly and brand. 3) Higher group had significantly difference in aesthetic value and political value, and lower had significantly differene ineconomic value and theoretical value.

• The Journal of the Korea Contents Association
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• 제17권10호
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• pp.567-575
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• 2017

In this study, when diagnosis pancreatic cancer by dual time point PET/CT, we propose SUVm 2.52 as the threshold value for performing the dual time point PET/CT exam. The hypothesis of normal distribution was adopted through data conversion of 60 pancreatic diseases. The proposed SUVm2.52 boundary value showed a significance level that could be applied to both 120 and 180 minutes of delay time scan for pancreatic cancer determination (p<0.05). C-value variation shows that delay time 2 hour test is more useful than delay time 3 hour test. When the SUVm 2.52 is set to the boundary value and the double-time point PET/CT exam is performed, the probability of distinguishing cancer from inflammation in the delayed image is 95%. When the delayed test is performed with the proposed boundary value SUVm 2.52, Compared with general PET / CT scans, it is thought that it may be helpful to distinguish pancreatic cancer.