• Korean Journal of Radiology
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• v.21 no.9
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• pp.1095-1103
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• 2020

Objective: The present study aimed to investigate whether quantitative dual-energy computed tomography (DECT) parameters offer an incremental risk stratification benefit over the CT ventricular diameter ratio in patients with acute pulmonary embolism (PE) by using propensity score analysis. Materials and Methods: This study was conducted on 480 patients with acute PE who underwent CT pulmonary angiography (CTPA) or DECT pulmonary angiography (DE CT-PA). This propensity-matched study population included 240 patients with acute PE each in the CTPA and DECT groups. Altogether, 260 (54.1%) patients were men, and the mean age was 64.9 years (64.9 ± 13.5 years). The primary endpoint was all-cause death within 30 days. The Cox proportional hazards regression model was used to identify associations between CT parameters and outcomes and to identify potential predictors. Concordance (C) statistics were used to compare the prognoses between the two groups. Results: In both CTPA and DECT groups, right to left ventricle diameter ratio ≥ 1 was associated with an increased risk of all-cause death within 30 days (hazard ratio: 3.707, p < 0.001 and 5.573, p < 0.001, respectively). However, C-statistics showed no statistically significant difference between the CTPA and DECT groups for predicting death within 30 days (C-statistics: 0.759 vs. 0.819, p = 0.117). Conclusion: Quantitative measurement of lung perfusion defect volume by DECT had no added benefit over CT ventricular diameter ratio for predicting all-cause death within 30 days.

• Phonetics and Speech Sciences
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• v.3 no.2
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• pp.53-61
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• 2011

The present work is a follow-up study to that of Han, Choi, Lim and Lee (2011), where an asymmetry in the source segments eliciting the interlanguage speech intelligibility benefit (ISIB) was found such that the vowels which did not match any vowel of the Korean language were likely to elicit more ISIB than matched vowels. In order to identify the source of the stronger ISIB in non-matched vowels, acoustic analyses of the stimuli were performed. Two pairs of English front vowels [i] vs. [I], and $[{\varepsilon}]$ vs. $[{\ae}]$ were recorded by English native talkers and two groups of Korean learners according to their English proficiency, and then their vowel duration and the frequencies of the first two formants (F1, F2) were measured. The results demonstrated that the non-matched vowels such as [I], and $[{\ae}]$ produced by Korean talkers seemed to show more deviated acoustic characteristics from those of the natives, with longer duration and with closer formant values to the matched vowels, [i] and $[{\varepsilon}]$, than those of the English natives. Combining the results of acoustic measurements in the present study and those of word identification in Han et al. (2011), we suggest that relatively better performance in word identification by Korean talkers/listeners than the native English talkers/listeners is associated with the shared interlanguage of Korean talkers and listeners.

• Health Policy and Management
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• v.20 no.3
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• pp.104-122
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• 2010

Long-term care insurance has been introduced in Korea a year ago, and we are in a stage requiring to set principles regarding the generosity of coverage and how to gradually extend the coverage. This study empirically analyzes how the long-term care insurance in Korea is operated. Special attention is given to who is the main beneficiary of the long-term care insurance introduction, and what is the factors influencing the elderly's decision to apply for or use long-term care services. Use of a detailed information of individuals' public health insurance and long-term care insurance from administration data made it possible to control for health status, socioeconomic status including family type, housing tenure, income level. Logit models were employed to analyze the effects of various socioeconomic factors on the likelihood of applying and using long-term care services. Also, this study employed a survey questioning whether to ever willing to take other option as a alternative to residential care or home-care and the level of cash benefit for which they are willing to replace the formal care with informal care. The result indicated that although the poorest elderly population groups are in the greatest need for the long-term care service, they are in difficulty using the service due to economic burden. This implies the copayment amount needs to be adjusted in order for the poor elderly group to be able to get the benefit of the long-term care service.

• Phonetics and Speech Sciences
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• v.3 no.1
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• pp.51-65
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• 2011

This study attempts to investigate the interlanguage speech intelligibility benefit for listeners (ISIB-L), examining Chinese talkers' production of English liquids and its perception of native listeners and non-native Chinese and Korean listeners. An Accent Judgment Task was conducted to measure non-native talkers' and listeners' phonological proficiency, and two levels of proficiency groups (high and low) participated in the experiment. The English liquids /l/ and /r/ produced by Chinese talkers were considered in terms of positions (syllable initial and final), contexts (segment, word and sentence) and lexical density (minimal vs. nonminimal pair) to see if these factors play a role in ISIIB-L. Results showed that both matched and mismatched interlanguage speech intelligibility benefit for listeners occurred except for the initial /l/. Non-native Chinese and Korean listeners, though only with high proficiency, were more accurate at identifying initial /r/, final /l/ and final /r/, but initial /l/ was significantly more intelligible to native listeners than non-native listeners. There was evidence of contextual and lexical density effects on ISIB-L. No ISIB-L was demonstrated in sentence context, but both matched and mismatched ISIB-L was observed in word context; this finding held true for only high proficiency listeners. Listeners recognized the targets better in the non-minimal pair (sparse density) environment than the minimal pair (higher density) environment. These findings suggest that ISIB-L for English liquids is influenced by talkers' and listeners' proficiency, syllable position in association with L1 and L2 phonological structure, context, and word neighborhood density.

• Journal of Korea Technology Innovation Society
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• v.7 no.3
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• pp.657-679
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• 2004

The purpose of this paper is to measure economic impact of marine environment conservation research development project. Benefit-Cost(B/C) analysis and Contingent Valuation Methods(CVM) are used to valuate the benefits from the research development projects. A period of three years for research development fund is considered as a part of the costs and adjusted to the net present value (NPV) of the 2002 ending period. The environmental charges for marine environment improvement are considered for the benefit measurement. The benefits are estimated by using monthly average willingness to pay, which is 2,289 Korean won. The contribution of the developing a management model for environmental pollution in the Gwangyang Bay is evaluated utilizing survey data and information. Based on the assessment by expert groups, the contribution of the model was 37.5％. The research results showed that B/C ratio is 20.61, NPV is 89,200 million Korean won, and social rate of return is 185.7％. When the level of contribution is over 1.83％ at the assessment of potential influence, it is recognized to be economically feasible. This research presents a quantitative framework for Research and Development projects for marine environment conservation, and it can be applied to decision making for the investment size of R&D projects.

• Journal of the Korean Operations Research and Management Science Society
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• v.7 no.1
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• pp.31-43
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• 1982

A general equilibrium growth model is constructed to analyse the income distributional impacts of the 1973 world oil crisis upon the Korean economy. Our results show that all consumer groups experienced a virtually uniform percentage reduction in their income levels. This implies that a lower income groups may be more damaged in a relative sense. In any rate, there were no domestic groups who benefit from the international oil crisis. This model could be used to figure out which social group will be most vulnerable against the next possible oil crisis we may expect in the future. Our result nay provide us a guideline for a compensating program to protect such groups against an external shock.

• The Mathematical Education
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• v.41 no.1
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• pp.45-58
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• 2002

This study was conducted to investigate the gender-related effects of two instructional programs on spatial visualization skills of ninth grade students. Two instructional programs were developed for this study: a web-based virtual reality program and a paper-based program. 194 ninth graders from two middle schools in Seoul participated in this study. Six classes were divided into experimental groups and control groups. The Middle Grades Mathematics Projects (MGMP) Spatial Visualization Test was used to measure spatial visualization skills. The data analysis indicated that both the web-based and paper-based programs were effective to improve spatial visualization skills to treatment groups. Although boys'test mean scores were higher than girls' in the pretest, when deleting the effect of covariance of pretest, there were no statistical significance in the post-test. Girls in the treatment groups favored the paper-based spatial visualization program. These results imply that spatial training may benefit girls' performance more than that of boys and mode of instructional programs can create gender-related differences regarding spatial visualization skills.

• Journal of Korean Home Economics Education Association
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• v.18 no.4 s.42
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• pp.13-23
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• 2006

The purposes of this study were to classify high school male and female students according to body cathexis and appearance interest, and understand their appearance management behaviors and clothing benefits sought. The results were as follows : First, the body cathexis of high school students were low, and female students had lower body cathexis than male students especially in the lower halves of bodies. The appearance interests of students were high, but female students had higher appearance interests than male students. Second, male students were classified by body cathexis and appearance interest into three groups with high, middle, and low body cathexis and appearance interest, and most of them belonged to the middle group. Female students were classified into four groups(with high body cathexis and appearance interest, with high body cathexis but low appearance interest, with low body cathexis but high appearance interest, and with low body cathexis and appearance interest) and most of them belonged to the group with low body cathexis but high appearance interest. Third, male students in groups with high and middle body cathexis and appearance interest showed more appearance management behaviors than those in the group with low body cathexis and appearance, while management behavior, followed by the group with low body cathexis but high appearance interest, that with high body cathexis but low appearance interest, and that with low body cathexis and appearance interest. Fourth, female students sought more aesthetics, fashionability, brand, and price in clothing coml)wed to male students. Male students in high and middle groups tended to seek more aesthetics, fashionability, and brand than those in the low group, but all three groups didn't consider price benefit sought. Female students with high body cathexis and appearance interest tended to seek more aesthetics and fashionability than those in other three groups. And only the group with low body cathexis and appearance interest didn't consider brand benefit sought. All four groups were found to consider price benefit sought. I hope that results of this study help teachers to guide students' clothing life more positively by understanding their appearance management behaviors and clothing benefits sought than to control negatively.

• Korean Management Science Review
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• v.25 no.1
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• pp.169-191
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• 2008

In this paper, we examined the difference of the effects of buying factors in two consumer segments divided by the innovative behavior for digital convergence products, and developed relevant managerial implications. As the digital convergence product could be understood as a innovative bundling product, the buying factors of the digital convergence products were clustered in 3 groups : common innovation-bundling factors, innovation factors and bundling factors. Tests for the difference of regression coefficients of the purchasing factors in the two markets show that (1) the early market is affected by both of the common innovation-bundling factors and the innovation factors, while the mainstream market is affected by all of the common innovation-bundling factors. the innovation factors and the bundling factors, (2) the early market is more affected by the technical benefit, while the mainstream market is more affected by the pragmatic benefit, and (3) both of the two markets are affected by the compatibility and the message communicability. The relevant managerial implications for the successive diffusion of the digital convergence products can include (1) in the entire period of the diffusion. enhancing the compatibility between consumer and product concept, performing constant and differentiated marketing communication activities, (2) in the early market of the diffusion, introducing unique innovative product which provides obvious and differential synergy through the convergence, appealing to the technical benefit, and (3) in the mainstream market of the diffusion, improving the qualities and features of individual products for the digital convergence product, appealing to the pragmatic benefit, reducing the complexity of product.

• Journal of the Korean Society of Costume
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• v.67 no.1
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• pp.22-39
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• 2017

This study intended to empirically verify the effect of message framing, cognitive need for closure, and type of fashion products on purchasing attitude of PB fashion products in discount stores. The design consisted of three-mixed design of 2(POP(Point of Purchase)message framing: benefit message vs. loss message) ${\times}2$(cognitive need for closure: high vs. low) ${\times}2$(PB fashion product type: utilitarian vs. hedonic). Survey of this study was conducted on 330 men and women in 20~50's in Seoul and Gyeong-gi, and a total of 287 data were analyzed. Data were analyzed with SPSS 18.0 program, and three-way ANOVA, simple interaction effects and simple main effects analysis were conducted. The results of this study are as follows: First, it was identified that the framing type of POP message of discount store, cognitive need for closure, and PB fashion product type had significant effect on preference and purchase intention. Secondly, it was identified that consumers with both high and low cognitive need for closure had high preference level and purchase intention when they encountered the benefit message framing than the loss message framing. Thirdly, the benefit message framing was more effective than the loss message framing for hedonic PB fashion products in discount stores, but utilitarian PB fashion products did not get affected by the message framing. Fourthly, it was identified that groups with both high and low cognitive need for closure preferred hedonic PB fashion products. Lastly, it was verified that benefit message framing POP advertisement on a group with high cognitive need for closure was effective for Hedonic PB fashion products in discount stores, and utilitarian PB fashion products showed no difference in purchase intention according to the POP message framing type and cognitive need for closure.