• Proceedings of the KIPE Conference
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• 2017.07a
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• pp.381-382
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• 2017

본 논문에서는 다항 모델을 이용하여 인버터의 병렬 운전을 위한 드룹 제어방식을 제안한다. 인버터의 병렬운전을 제어하는 방법 중 통신 없이 유효전력과 무효전력을 이용하여 출력전압의 크기와 주파수를 제어하는 드룹 제어가 많이 사용된다. 기존의 드룹 제어에서는 응답속도를 증가시키면 정상상태 오차가 커지는 문제점이 발생한다. 따라서 본 논문에서는 다항 모델을 이용하여 개선된 드룹 제어방식을 제안하고 시뮬레이션을 통해 검증한다.

• Journal of Korean Society of Transportation
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• v.16 no.4
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• pp.53-64
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• 1998

본 연구의 목적은 '96년말 서울시에서 실시한 가구통행조사를 이용하여 서울시 수단선택모형을 구축하고 그 예측결과를 남산 혼잡통행료 전후저사자료와 비교하여 보다 구체적으로 그 정확성을 검증한 뒤 향후 서울시 교통수요관리 방안의 시행에 따른 수단선택변화 예측의 기본 모형으로 활용하는데 있다. 5가지의 대안모형의 분석결과 통행비용변수(승용차의 경유 주차요금포함)와 총통행시간변수(OVTT와 IVTT의 합), 승용차, 지하철, 택시상수로 구성된 모형이 최적모형으로 분석되었다. 이모형에 의한 시간가치는 9,395원, 승용차의 비용탄력성은-0.6767로서 기존 연구결과의 범위 내에 속한 것으로 나타났다. 최적모형을 이용하여 승용차통행비용이 증가한 경우를 모사분석결과 남산1,3호 터널 혼잡통행료 징수효과와 유사하게 승용차 분담율이 13% 가까이 감소한 것으로 나타나서 모형의 현실적합성도 비교적 높은 것으로 판명되었다. 향후 본 연구에서 선정된 최적수단선택모형을 통행배정모형과 결합하여 다양한 교통수요관리 방안에 따른 효과를 예측하는데 활용하면 서울과 같은 대도시의 단기적 교통관리의 수준을 한 단계 높이는데 기여할 것으로 판단된다.

• Proceedings of the Korean Society for Information Management Conference
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• 2014.08a
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• pp.149-152
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• 2014

본 연구에서는 저자명 모호성 해소를 위해 토픽모델링 기법을 사용하여 저자명을 식별 하였다. 기존의 토픽모델링은 용어 자질만을 고려하였지만 본 연구에서는 제 3의 메타데이터 자질을 활용하여 ACT(Author-Conference Topic Model) 모델과 DMR(Dirichlet-multinomial Regression) 토픽모델링을 대상으로 저자명 식별 성능을 평가, 비교하였다. 또한 수작업으로 저자 식별 작업을 한 데이터셋을 기반으로 저자 당 논문 수와 토픽 수에 차이를 두고 연구를 진행하였다. 그 결과 저자명 식별에 있어 ACT 모델보다 DMR 토픽모델링의 성능이 더 우수한 것을 알 수 있었다.

• Smart Media Journal
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• v.5 no.4
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• pp.75-82
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• 2016

Although Korea's economic and domestic automobile market through the change of road environment are growth, the traffic accident rate has also increased, and the casualties is at a serious level. For this reason, the government is establishing and promoting policies to open traffic accident data and solve problems. In this paper, describe the method of predicting traffic accidents by eliminating the class imbalance using the traffic accident data and constructing the Hybrid Model. Using the original traffic accident data and the sampled data as learning data which use FP-Growth algorithm it learn patterns associated with traffic accident injury severity. Accordingly, In this paper purpose a method for predicting the severity of a victim of a traffic accident by analyzing the association patterns of two learning data, we can extract the same related patterns, when a decision tree and multinomial logistic regression analysis are performed, a hybrid model is constructed by assigning weights to related attributes.

• Journal of Korean Society of Transportation
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• v.19 no.3
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• pp.19-32
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• 2001

A parking facility choice model. which can be applied to analyze of the driver's parking behavioral changes in response to the local government's parking policy changes and to predict parking demand by the facility types, is developed. Under the context of the stated preference discrete choice model, socioeconomic variables and parking alternative characteristic variables are introduced as explanatory variables. A parking facility choice model for the shopping trip purpose is derived using multinomial logit model and nested logit model and the stated preference data collected in Taegu metropolitan area. The result shows that the sign of all the estimated parameters are logically consistent and the model's goodness of fit is reasonably good. As a result of the elasticity analysis of the model, the elasticity of parking cost is highest, and the elasticity of walking distance between parking place and the destination is higher than parking place searching and ingress time. This means that the parking places are supplied around the destination in the form of small-size parking place. The findings in this study is expected to provide a fundamental data for various short-term parking policy analyses and for parking facility's demand estimations.

• Journal of Korean Society of Transportation
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• v.25 no.3
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• pp.111-121
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• 2007

A transit assignment model can forecast the behaviors of transit users. thereby playing an important role In the evaluation of transit policies. Most existing transit assignment models are based on the models for passenger cars; therefore they cannot reflect the specific characteristics of transit modes. In addition most of the existing models are based on a single transit mode (bus or rail), and they cannot forecast the behaviors of transit users in a changing mass transportation system. The goal of this study is to overcome these problems with the exiting models and to develop a more realistic model. The newly developed model is based on mixed transit modes and is a stochastic model that can reflect the different preferences of each transit user for travel time and transfering. Data gathered from the Seoul metropolitan area's smart card are used to calibrate this model. This study is expected to be used for the evaluation of transportation policies and to attribute the development of transit revitalization strategies.

• Journal of Sasang Constitutional Medicine
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• v.32 no.1
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• pp.30-38
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• 2020

Objectives The purpose of this study is to reduce the question items in Korea Sasang Constitutional Diagnostic Questionnaire (KS-15) and to assess the validity. Methods The subjects of this study were 1,553 people who had information on body shape, personality, and symptoms among the data established at the Korean Medicine Data Center. Among them, 155 people were separated into a test group to assess the validity, and the remaining 1,398 were used as training groups for model development. The reduction question items were finally confirmed through discussion by two experts. The model development went through Multinomial Logistic Regression. Results & Conclusions The Percent Correctly Predicted (PCP) in the test group was 60.00% (58.49% in men and 60.78% in women). The PCP of each constitution was 72.6% in Taeeumin, 53.3% in Soeumin, and 50% in Soyangin. The accuracy rate of KS-10 seems to be reasonable considering the ease of use of reduced time required.

• Human Ecology Research
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• v.51 no.3
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• pp.321-331
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• 2013

The purpose of this study is to develop the scale to measure family health and to analyze the data collected by the survey in order to develop the educational program for healthy family. The sample of this study is taken by 522 housewives who are living in Seoul and are over the age of 40. The data are analyzed according to frequency, percentages, t-test, Pearson's correlation analysis, and Multinomial logistic Regression analysis. The results of this study are as follows. First, the scale measuring family health is developed through interviews with the respondents, preliminary survey, and comments reviewed from specialists. The responses to the scale are significantly different depending on whether they answered their family is healthy or not. Second, minimum family performances for family health are related to the category of social involvement of the family. Third, the types of healthy family are grouped by the responses related to the current state and the status of family health. The number of the type of the worst state-the worst status of family health is the largest, followed by the number of the type of the best state-the best status of family health. Fourth, the important and significant variables that affected the types of family health are psychological variables rather than personal and household-related variables of the respondents.

• Journal of the Korean Association of Geographic Information Studies
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• v.15 no.1
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• pp.64-75
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• 2012

To predict the future distribution of forest vegetation, the present forest stand distributions of South Korea were represented by multinomial logit model with the following environmental variables: summer average precipitation, the coldest month average temperature, elevation, degree of base saturation, and soil organic matter. The future forest community was predicted by applying the MIROC3.2 hires A1B scenario. The future climate data were downscaled by statistically method. The coldest month average temperature increased $4.4^{\circ}C$, $6.0^{\circ}C$, and $9.4^{\circ}C$, and 3 months average precipitation changed -1.2%, 5.7%, and 5.3% for 2020s, 2050s, and 2080s respectively. For the projected summer precipitation and the coldest temperature, the future deciduous and mixed forests in the study area increased 56.9% and 8.3% and the coniferous forest decreased 11.2% in 2080s based on present.

• The Journal of the Korea Contents Association
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• v.19 no.4
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• pp.403-412
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• 2019

There has been a lively debate between self-employed and wage workers on the speed of minimum wage hikes. Minimum wage is a redistributive policy that evokes confrontation and conflict whereby individuals' views on the policy coincide with their material self-interest. With this in mind, the researcher analyzed whether an individual's labor market status was explanatory to his/her view on the speed of minimum wage hike. Moreover, in light of the likelihood that the varying degree to which self-employed can afford minimum wage hike affects their differential preferences for the policy, the researcher attempted to identify whether there was a moderation effect of income class on the relationship. In the actual analysis, the researcher investigated employment policy survey dataset using a multinomial logit model. The results suggest that, among self-employed, 'gradual increase' and 'rapid increase' of minimum wages are less preferred $vis-{\grave{a}}-vis$ 'minimal increase,' which is the reference. As to the moderation effect, when a self-employed has a middle-income class status, his/her negative preference for the policy is likely to be attenuated. One implication of this study is that subsidizing self-employed small business owners, who are most dissatisfied with the current speed at which minimum wages rise, would be an effective prescription on reducing social conflicts.