• Investigative Magnetic Resonance Imaging
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• v.24 no.1
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• pp.38-45
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• 2020

Background: Differentiation of cerebellopontine angle (CPA) schwannoma from meningioma is often a difficult process to identify. Purpose: To identify imaging features for distinguishing CPA schwannoma from meningioma and to investigate the usefulness of susceptibility-weighted imaging (SWI) in differentiating them. Materials and Methods: Between March 2010 and January 2015, this study pathologically confirmed 11 meningiomas and 20 schwannomas involving CPA with preoperative SWI were retrospectively reviewed. Generally, the following MRI features were evaluated: 1) maximal diameter on axial image, 2) angle between tumor border and adjacent petrous bone, 3) presence of intratumoral dark signal intensity on SWI, 4) tumor consistency, 5) blood-fluid level, 6) involvement of internal auditory canal (IAC), 7) dural tail, and 8) involvement of adjacent intracranial space. On CT, 1) presence of dilatation of IAC, 2) intratumoral calcification, and 3) adjacent hyperostosis were evaluated. All features were compared using Chi-squared tests and Fisher's exact tests. The univariate and multivariate logistic regression analysis were performed to identify imaging features that differentiate both tumors. Results: The results noted that schwannomas more frequently demonstrated dark spots on SWI (P = 0.025), cystic consistency (P = 0.034), and globular angle (P = 0.008); schwannomas showed more dilatation of internal auditory meatus and lack of calcification (P = 0.008 and P = 0.02, respectively). However, it was shown that dural tail was more common in meningiomas (P < 0.007). In general, dark spots on SWI and dural tail remained significant in multivariate analysis (P = 0.037 and P = 0.012, respectively). In this case, the combination of two features showed a sensitivity and specificity of 80% and 100% respectively, with an area under the receiver operating characteristic curve of 0.9. Conclusion: In conclusion, dark spots on SWI were found to be helpful in differentiating CPA schwannoma from meningioma. It is noted that combining dural tail with dark spots on SWI yielded strong diagnostic value in differentiating both tumors.

• Asian Pacific Journal of Cancer Prevention
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• v.15 no.8
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• pp.3513-3518
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• 2014

The 14-3-3 protein has been shown to be involved in the cancer process. However, there is no understanding of the relationship between 14-3-$3{\gamma}$ (14-3-3 gamma) expression and prognosis in advanced non-small cell lung cancer. In this study, we therefore investigated the association between protein levels by immunohistochemistry and clinicopathological features of advanced NSCLC patients. Survival curves were estimated using the Kaplan-Meier method and tested by log-rank. Multivariate analysis was conducted with the Cox's regression model to determine independence of factors. p values less than 0.05 were considered significant. A total 153 patients were studied, with 54.3% being stage III and 45.8% stage IV. Fifty-one cases (33.3%) were squamous cell carcinomas, and 98 cases (64.1%) were adenocarcinomas. High 14-3-$3{\gamma}$ expression was seen in 59.5% and significantly correlated with lymph node metastasis (p=0.010) and distant metastasis (p=0.017). On Kaplan-Meier analysis, high 14-3-$3{\gamma}$ expression was associated with poorer survival with a marginal trend toward significance (p=0.055). On multivariate analysis, age, treatment, and 14-3-$3{\gamma}$ expression proved to be independent prognostic parameters. In vitro experiments indicated that 14-3-$3{\gamma}$ overexpression also played a potential role in cancer invasion. In conclusion, our data suggest that 14-3-$3{\gamma}$ overexpression is associated with invasion and a poor prognosis. Therefore, 14-3-$3{\gamma}$ may be a potential prognostic marker of advanced non-small cell lung cancer.

• Korea Real Estate Review
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• v.24 no.1
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• pp.15-26
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• 2014

Using multivariate GARCH model, we estimate the relationship between the housing sale prices and lease prices in the Korean housing market. In the analysis of relationship between the rate of changes in sale and lease prices, the correlation coefficient of the apartment and detached house is higher than that of the townhouse. By housing type, the correlation coefficient between detached house and townhouse is higher than between apartment and detached house or apartment and townhouse. By housing size, there are no significant different results between the sales price and the rental price. The correlation coefficient between medium and small size is the highest in the apartment housing market, whereas the correlation coefficient between large and medium size is the highest in the detached housing market, resulting from the fact that people may be more interested in medium- and small-sized apartment and large- and medium-sized detached house. In the detached housing market, the correlation coefficient between large-medium size and medium-small size in the rental price is higher than that of sales price. This result implies that the process of the decision making between purchasing and leasing a house might be different.

• Journal of Korean Society of Coastal and Ocean Engineers
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• v.24 no.5
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• pp.305-318
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• 2012

Although the existing performance-based design method for the vertical breakwater evaluates an average sliding distance during an arbitrary time, it does not calculate the probability of the first occurrence of an event exceeding an allowable sliding distance(i.e. the first-passage probability). Designers need information about the probability that the structure is damaged for the first time for not only design but also maintenance and operation of the structure. Therefore, in this study, a time-dependent reliability design method based on a stochastic process is developed to evaluate the first-passage probability of caisson sliding. Caisson sliding can be formulated by the Poisson spike process because both occurrence time and intensity of severe waves causing caisson sliding are random processes. The occurrence rate of severe waves is expressed as a function of the distribution function of sliding distance and mean occurrence rate of severe waves. These values simulated by a performance-based design method are expressed as multivariate regression functions of design variables. As a result, because the distribution function of sliding distance and the mean occurrence rate of severe waves are expressed as functions of significant wave height, caisson width, and water depth, the first-passage probability of caisson sliding can be easily evaluated.

• Journal of Global Scholars of Marketing Science
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• v.19 no.2
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• pp.17-26
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• 2009

As the lifestyle of consumers changes and the need for various products increases, new products are being developed in the market. Each household owns various home appliances which are purchased through the choice of a decision maker. These appliances include not only large-sized products such as TV, refrigerator, and washing machine, but also small-sized products such as microwave oven and air cleaner. There exists latent correlation among possession of home appliances, even though they are purchased independently. The purpose of this research is to analyze the effect of demographic factors on the purchase and possession of each home appliances, and to derive some relationships among various appliances. To achieve this purpose, the present status on the possession of each home appliances are investigated through consumer survey data on the electric and energy product. And a multivariate probit(MVP) model is applied for the empirical analysis. From the estimation results, some appliances show a substitutive or complementary pattern as expected, while others which look apparently unrelated have correlation by co-incidence. This research has several advantages compared to previous literatures on home appliances. First, this research focuses on the various products which are purchased by each household, while previous researches such as Matsukawa and Ito(1998) and Yoon(2007) focus just on a particular product. Second, the methodology of this research can consider a choice process of each product and correlation among products simultaneously. Lastly, this research can analyze not only a substitutive or complementary relationship in the same category, but also the correlation among products in the different categories. As the data on the possession of home appliances in each household has a characteristic of multiple choice, not a single choice, a MVP model are used for the empirical analysis. A MVP model is derived from a random utility model, and has an advantage compared to a multinomial logit model in that correlation among error terms can be derive(Manchanda et al., 1999; Edwards and Allenby, 2003). It is assumed that the error term has a normal distribution with zero mean and variance-covariance matrix ${\Omega}$. Hence, the sign and value of correlation coefficients means the relationship between two alternatives(Manchanda et al., 1999). This research uses the data of 'TEMEP Household ICT/Energy Survey (THIES) 2008' which is conducted by Technology Management, Economics and Policy Program in Seoul National University. The empirical analysis of this research is accomplished in two steps. First, a MVP model with demographic variables is estimated to analyze the effect of the characteristics of household on the purchase of each home appliances. In this research, some variables such as education level, region, size of family, average income, type of house are considered. Second, a MVP model excluding demographic variables is estimated to analyze the correlation among each home appliances. According to the estimation results of variance-covariance matrix, each households tend to own some appliances such as washing machine-refrigerator-cleaner-microwave oven, and air conditioner-dish washer-washing machine and so on. On the other hand, several products such as analog braun tube TV-digital braun tube TV and desktop PC-portable PC show a substitutive pattern. Lastly, the correlation map of home appliances are derived using multi-dimensional scaling(MDS) method based on the result of variance-covariance matrix. This research can provide significant implications for the firm's marketing strategies such as bundling, pricing, display and so on. In addition, this research can provide significant information for the development of convergence products and related technologies. A convergence product can decrease its market uncertainty, if two products which consumers tend to purchase together are integrated into it. The results of this research are more meaningful because it is based on the possession status of each household through the survey data.

• The Journal of the Korea Contents Association
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• v.20 no.11
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• pp.268-280
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• 2020

This research conducted an empirical analysis of factors that influence the process of job choices and start-ups among the youth. By conducting a comparative analysis on 6 countries with adequate career systems and booming startup industries (China, Indonesia, the UK, Germany, Israel, the US.). The statistical sample is based on the Global Entrepreneurship Trend Ratio and covers a total of 7,082 youth across 7 countries. Multivariate variance analysis and correlational analysis were conductedto compare the average figures among different countries and analyze the regulation effect of parental influence. Job satisfaction, parental influence, and willingness to change future job were selected as the factors that influence job choices. Korea's job satisfaction was the lowest among 7 countries and a willingness to change future job was the highest. Meanwhile, Korea's parental influence was at a medium level among 7 countries. It was proven that job satisfaction had a quasi-control effect on the process of influencing willingness to change future job. Entrepreneurial education, willingness to start-up, job satisfaction, and parental influence were chosen as the factors that influence start-up. Two-way ANOVA were conducted to comparatively analyze each country's average, mutual influence among different factors, and analyze the regulation effect of parental influence. In all countries, start-up education has the effect of raising the willingness to start-up. Also, it was verified that parental influence had a quasi-control effect in the process of career satisfaction influencing the willingness to start-up. The research results will provide meaningful implications for the government and educational institutes including universities when designing policy directions to guide overall career for the youth in the future.

• Korean Journal of Ecology and Environment
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• v.41 no.3
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• pp.374-381
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• 2008

Spatial and temporal changes of fish communities were studied at four study sites in the Cheonggye Stream from October 2005 to August 2006 after the rehabilitation process. During the survey period, 19 species in 6 families were sampled. Species Rhynchocypris oxycephalus and Zacco platypus were identified as dominant species. Korean endemic species such as Acheilognathus yamatsutae and Zacco koreanus were observed in the sites. Overall, species richness and abundance increased as time passes after the rehabilitation, reflecting colonization process of the fish community. Meanwhile species richness and abundance were higher at the downstream than at the upstream. Community indices such as dominant index, richness index and diversity index showed also similar spatial and temporal pattern. Nonmetric multidimensional scaling (NMDS), multivariate ordination technique, was used to analyze spatial and temporal variation of the fish communities, and the results showed spatial variation of fish communities with high species richness at downstream as well as the temporal variation of fish communities with high values of species richness and diversity index at later part of the study period, presenting colonization process of the fish community after the rehabilitation project.

• Asian Pacific Journal of Cancer Prevention
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• v.13 no.11
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• pp.5715-5719
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• 2012

The relation between cyclooxygenase enzymes and E-cadherin, along with the roles of these markers in the prediction of survival in optimally cytoreduced serous ovarian cancer patients was investigated. Individuals who underwent primary staging surgery and achieved optimal cytoreduction (largest residual tumor volume <1 cm) constituted the study population. Specimens of 32 cases were immunohistochemically examined for cyclooxygenase-1, cyclooxygenase-2, and E-cadherin. Two could not be evaluated for E-cadherin and cyclooxygenase-1. Overall, 14/30, 19/30, and 15/32 cases were positive for E-cadherin, cyclooxygenase-1, and cyclooxygenase-2, respectively. The expressions of E-cadherin and cyclooxygenase-2 were inversely correlated (p:0.02). E-cadherin expression was related with favorable survival (p<0.001). The relation between the expression of cyclooxygenase enzymes and poor survival did not reach statistical significance. On multivariate analysis, E-cadherin appeared as an independent prognostic factor for survival. In conclusion, E-cadherin expression is strongly linked with favorable survival. E-cadherin and cyclooxygenase 2 may interact with each other during the carcinogenesis-invasion process. Further studies clarifying the relation between E-cadherin and cyclooxygenase enzymes may lead to new preventive and therapeutic targets in ovarian cancer.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.8 no.6
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• pp.111-117
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• 2008

In this paper, we describes the boxing motion recognition which is used in the part of games, animation. To recognize the boxing motion, we have used two algorithms, one is principle component analysis, the other is dynamic time warping algorithm. PCA is the simplest of the true eigenvector-based multivariate analyses and often used to reduce multidimensional data sets to lower dimensions for analysis. DTW is an algorithm for measuring similarity between two sequences which may vary in time or speed. We introduce and compare PCA and DTW algorithms respectively. We implemented the recognition of boxing motion on the motion capture system which is developed in out research, and depict the system also. The motion graph will be created by boxing motion data which is acquired from motion capture system, and will be normalized in a process. The result has implemented in the motion recognition system with five actors, and showed the performance of the recognition.

• Journal of Korea Water Resources Association
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• v.50 no.1
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• pp.17-28
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• 2017

A recent increase in extreme weather events and flash floods associated with the enhanced climate variability results in an increase in climate-related disasters. For these reasons, various studies based on a high resolution weather radar system have been carried out. The weather radar can provide estimates of precipitation in real-time over a wide area, while ground-based rain gauges only provides a point estimate in space. Weather radar is thus capable of identifying changes in rainfall structure as it moves through an ungauged basin. However, the advantage of the weather radar rainfall estimates has been limited by a variety of sources of uncertainty in the radar reflectivity process, including systematic and random errors. In this study, we developed an ensemble radar rainfall estimation scheme using the multivariate copula method. The results presented in this study confirmed that the proposed ensemble technique can effectively reproduce the rainfall statistics such as mean, variance and skewness (more importantly the extremes) as well as the spatio-temporal structure of rainfall fields.