• Korean Journal of Human Ecology
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• v.21 no.2
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• pp.349-362
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• 2012

This paper explores differences demonstrated by changes of consumers' clothing expenditure in Korea and the United States since the mid-1990s. Evidence for this study was extrapolated from annual data provided by the Household Expenditure Survey, which was carried out in Korea between 1996 and 2008, and the Consumer Expenditure Survey, which was carried out in the United States during the same time period. The results include: (1) The proportion of the clothing expenditure decreased during the subject period in both Korea and the United States; (2) The decrease in proportional clothing expenditure was greater in Korea than in the United States; (3) Although the relative prices of clothes decreased greatly during this period in both countries, it was determined that the decrease in clothing prices in the United States was greater when compared to those in Korea; and (4) By using the DID(Difference in difference) model, the author contends that a decrease in clothing purchases contributed to the decrease of prices for clothing in the United States, while in Korea, the decrease in prices for clothing was also impacted by other factors including changes in household expenditures for education and communication.

• Journal of Korean Academy of Nursing Administration
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• v.19 no.2
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• pp.265-272
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• 2013

Purpose: This study was done to identify the effects and relationships of humor, job satisfaction, job stress and intent to turnover for nurses and suggest a theoretical structural path diagram among the variables. Methods: Data were collected at 6 hospitals located in Seoul, and Gyeonggi Province, from June to September, 2010. Participants were 275 nurses. Data were analyzed using Amos 19.0 for Structural Equation Modeling. Results: Humor had significant effects on job satisfaction (${\beta}$=.15, t=2.29, p=.022) and indirect effects on the intent to turnover in this model ($X^2$=44.18, df=23, RMSEA=0.05, TLI=0.97). But humor did not affect job stress unlike results of previous studies (t=-.02, p=.771). Conclusion: Humor may not affect job stress under the very stressful conditions of the health care environment. The model showed the effect of humor contributed to increases in job satisfaction but did not decrease job stress. Higher levels of job satisfaction could decrease the intent to turnover. Consequently, humor would be helpful in increasing job satisfaction to diminish nurse turnover. Further studies are suggested to investigate causal relationships among humor, burnout, and other emotional and organizational variables.

• Journal of the Korean Data and Information Science Society
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• v.21 no.2
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• pp.271-277
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• 2010

The randomized response technique is an indirect question that employs a randomizing device to protect respondents' privacy. The technique is now considered the most efficient of the newly developed techniques. In this technique, Chang et al. (2004) suggests an improved forced-answer technique and finds more efficient conditions than Warner did in 1965. But it is the weakness of the technique to lose more information than a direct response technique does. Therefore, a lot of researches have developed new techniques to reduce loss of information, to enhance estimated efficiency, and to efficiently use collected information. Considering this tendency, this paper also tries to improve Chang's technique. It suggests the technique that is extended from Chang's and finds more efficient conditions than Chang's technique and Mangat and Singh's (1990) did.

• Journal of Korean Elementary Science Education
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• v.31 no.1
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• pp.71-83
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• 2012

The purpose of this study was to explore ecological concepts, epistemological reasoning and reasoning processes through constructing 'food web and food pyramid' in ecology. We conducted classes which involved a 'food web and food pyramid' for $6^{th}$ grade students. Each class is constructed of small groups to do modeling and epistemological reasoning through communication. The researcher had videotaped and recorded each class and have made transcription about classes. We analysed patterns of 'food web and food pyramid models' and reasoning processes according to scientific epistemology using transcription data and student outputs. As a result, students represented phenomenon-based reasoning, relation-based reasoning and model-based reasoning in scientific epistemology from their modeling. Students usually did relation-based reasoning and model-based reasoning in food web which explains ecological phenonenon, while they usually did model-based reasoning in food pyramid which expects ecological phenomenon. Student's reasoning can be limited when they have misconception of scientific knowledge and are limited by fragmentary knowledge. This represents that students has to do relation-based reasoning and model-based reasoning is beneficial in their ecological model. It also suggests that students need to define correct-conception related to ecological modeling(food web, food pyramid).

• Journal of Korea Water Resources Association
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• v.44 no.10
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• pp.777-786
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• 2011

In the previous researches for storm sewer design, the flow path, pipe diameter and pipe slope were determined to minimize the construction cost. But in the sewer networks, the flows can be changed according to flow path. The current optimal sewer layout models have been focussed on satisfying the design inflow for sewer designs, whereas the models did not consider the occurrences of urban inundation from excessive rainfall events. However, in this research, the sewer networks are determined considering the superposition effect to reduce the inundation risk by controlling and distributing the inflows in sewer pipes. Then, urban inundation can be reduced for excessive rainfall events. An Optimal Sewer Layout Model (OSLM) was developed to control and distribute the inflows in sewer networks and reduce urban inundation. The OSLM uses GA (Genetic Algorithm) to solve the optimal problem for sewer network design and SWMM (Storm Water Management Model) to hydraulic analysis. This model was applied to Hagye basin with 44 ha. As the applied results, in the optimal sewer network, the peak outflow at outlet was reduced to 7.1% for the design rainfall event with 30 minutes rainfall duration versus that of current sewer network, and the inundation occurrence was reduced to 24.2% for the rainfall event with 20 years frequency and 1 hour duration.

• The Korean Journal of Applied Statistics
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• v.25 no.2
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• pp.363-376
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• 2012

Excessive zeroes are often observed in ordinal categorical response variables. An ordinary ordered Probit model is not appropriate for zero-inflated data especially when there are many different sources of generating 0 observations. In this paper, we apply a two-stage zero-inflated ordered Probit (ZIOP) model which incorporate the zero-flated nature of data, propose a Bayesian analysis of a ZIOP model, and apply the method to alcohol consumption data collected by the National Bureau of Statistics, Korea. In the first stage of a ZIOP model, a Probit model is introduced to divide the non-drinkers into genuine non-drinkers who do not participate in drinking due to personal beliefs or permanent health problems and potential drinkers who did not drink at the time of the survey but have the potential to become drinkers. In the second stage, an ordered probit model is applied to drinkers that consists of zero-consumption potential drinkers and positive consumption drinkers. The analysis results show that about 30% of non-drinkers are genuine non-drinkers and hence the Korean alcohol consumption data has the feature of zero-inflated data. A study on the marginal effect of each explanatory variable shows that certain explanatory variables have effects on the genuine non-drinkers and potential drinkers in opposite directions, which may not be detected by an ordered Probit model.

• Archives of design research
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• v.18 no.1 s.59
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• pp.223-232
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• 2005

By supply of high performance computer becomes all industries automation and convenient of our life. Can speak that is pursuit of swiftness and variety that is prior most development of information society and production system in competitive industrial design product development process. Specially, students who consumer personality studies design according to variableness must present idea in a short time. Therefore, find a new tool that can show quick modeling result for present of new idea or fast design specifications examination and production at college or corporation now. According to such environment change did request by cost time and cost-cutting until reach in production from product design because competition is gone vigorously. University arrived to think RP induction by result presentation and so on for third dimension model by various design process. This research purpose is going to compare difference methods(Manual processing, CNC machine) with students' design result manufacture process on RP appliance that is using in college. Consequently, think that this study is helpful in the college of which is making use of RP appliance or planning installation. By result of this research, model of big curved line is profitable in hand process, by CNC Is profitable when model is going to manufacture finely, RP work could know that size of product is profitable small thing as is complicated.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.18 no.11
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• pp.690-696
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• 2017

Various types of alternative energy sources to petroleum are being developed both domestically and internationally as clean energy that does not emit greenhouse gases. In particular, offshore wind power has been studied because the wind resources are relatively limitless and the wind power is relatively smaller than onshore. In this study, to analyze the scour phenomenon around offshore wind foundations, mono pile and tripod pile foundations were simulated using a FLOW-3D model. The scour phenomenon was evaluated for mono piles: one is a pile with a 5 m diameter and d=1.69 m and the other is a pile with a 5 m diameter. Numerical analysis showed that in the latter, the falling-flow increased and the maximum scour depth occurred more than 1.7 times. For a tripod pile foundation, the measured velocity and the maximum wave condition were applied to the upstream boundary condition, respectively, and the scour phenomenon was evaluated. When the maximum wave condition was applied, the maximum scour depth occurred more than about 1.3 times. When the LES model was applied, the scour depth reached equilibrium, whereas the numerical results of the RNG model show that the scour phenomenon occurred in the entire boundary area and the scour depth did not reach equilibrium. To evaluate the scour phenomenon around offshore wind foundations, it is reasonable to apply the wave condition and the LES turbulence model to numerical model applications.

• Journal of Digital Convergence
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• v.15 no.2
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• pp.121-133
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• 2017

The propose of study is to examine the characteristics of companies with high possibility to form an internal control weakness using forecasting model. This study use the actual listed/unlisted companies' data from K_financial institution. The first conclusion is that discriminant model is more valid than logit model to predict internal control weak companies. A discriminant model for predicting the vulnerability of internal control has high classification accuracy and has low the Type II error that is incorrectly classifying vulnerable companies to normal companies. The second conclusion is that the characteristic of weak internal control companies have a low credit rating, low asset soundness assessment, high delinquency rates, lower operating cash flow, high debt ratios, and minus operating profit to the net sales ratio. As not only a case of listed companies but unlisted companies which did not occur in previous studies are extended in this study, research results including the forecasting model can be used as a predictive tool of financial institutions predicting companies with high potential internal control weakness to prevent asset losses.

• School Mathematics
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• v.16 no.2
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• pp.387-407
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• 2014

Gender differences have been given major attention in mathematics education in the context of pursuing gender equity in instructional and learning environment. It had been traditional belief that male students would outperform female students in mathematics, especially in the areas as geometry. This belief has been given doubts by cumulated empirical evidences that gender differences are gradually diminishing or even reversing its direction as time goes on. In this study, gender differences in geometry were explored using TIMSS 8th grade mathematics data administered in TIMSS 2003, 2007, and 2011, based on a cognitive diagnostic modeling(CDM) approach. Among various CDM models, the Fusion model was employed. The Fusion model has advantages over other CDM models in that it provides more detailed information about gender differences at the attribute level as well as item level and more mathematically tractable. The findings of this study show that Attribute 3(Three-dimensional Geometric Shapes) revealed statistically significant gender differences favoring male students in TIMSS 2003 and 2007, but did not show significant differences in TIMSS 2011, which provides an additional empirical evidence supporting the recent observation that gender gap is narrowing. In addition to the general trends in gender differences in geometry, this study also provided affluent information such as gender differences in attribute mastery profiles and gender differences in relative contributions of each attribute in solving a particular item. Based on the findings of the CDM approach exploring gender differences, instructional implications in geometry education are discussed.