• Proceedings of the Korean Institute of Surface Engineering Conference
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• 2018.06a
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• pp.139-139
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• 2018

최근 자동차 산업을 중심으로 한 수송용 기기의 경량화 추세에 따라 대표적인 경량금속 소재인 알루미늄 합금에 대한 수요가 증가하고 있으며 이에 따라 알루미늄 합금 표면에 다양한 특성을 부여할 수 있는 표면개질 기술에 대한 필요성이 부각되고 있다. 알루미늄 합금의 대표적인 표면처리기술인 아노다이징과 유사한 원리로 표면에 세라믹 코팅층을 형성할 수 있는 기술인 플라즈마 전해 산화(Plasma electrolytic oxidation, PEO)가 주목을 받고 있다. PEO 코팅법은 전해액 내에 소재를 침지시키고 400 ~ 600V에 이르는 고전압을 인가시켜 마이크로 방전을 유도하여 표면에 치밀한 세라믹 층을 형성시키는 기술이다. 본 연구에서는 PEO법으로 표면 개질된 Al 합금 표면의 표면 조직 특성과 전기화학 특성을 평가하고, 코팅층 특성에 미치는 공정 변수의 영향을 분석하고자 하였다. PEO 처리를 위해 사용된 소재는 상용 Al 합금 판재(Al 5083-O)로서 $2cm{\times}2cm$로 절단하여, 에머리페이퍼로 1000번까지 연마하여 사용하였다. 시험을 위한 PEO 처리 시스템은 전해액 수조, 일정 온도 유지를 위한 열교환기와 칠러, 전원 발생을 위한 전원공급기(power supply)로 구성되었다. 전해액은 약 알칼리 수용액을 이용하였으며, 전원 공급기를 통해 시험편에 펄스 전류를 인가하였다. PEO 처리 후 시편에 대하여 SEM, EDS, XRD 등을 이용한 표면 특성 평가를 실시하였다. 또한 코팅층의 전기화학적 부식 특성 평가를 위해 해수용액에서 동전위분극실험을 실시하였다. 시험 결과, Al 합금의 PEO 처리 시 내식성은 개선되는 것으로 확인되었으며, 공정변수는 표면의 미세조직 및 전기화학적 특성에 큰 영향을 미치는 것으로 나타났다.

• KIPS Transactions on Software and Data Engineering
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• v.3 no.7
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• pp.263-270
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• 2014

This paper suggests a method for predicting a box-office success of the film. Lately, as the growth of the film industry, a variety of studies for the prediction of market demand is being performed. The product life cycle of film is relatively short cultural goods. Therefore, in order to produce stable profits, marketing costs before opening as well as the number of screen after opening need a plan. To fulfill this plan, the demand for the product and the calculation of economic profit scale should be preceded. The cases of existing researches, as a variable for predicting, primarily use the factors of competition of the market or the properties of the film. However, the proportion of the potential audiences who purchase the goods is relatively insufficient. Therefore, in this paper, in order to consider people's perception of a movie, Twitter was utilized as one of the survey samples. The existing variables and the information extracted from Twitter are defined as off-line and on-line element, and applied those two elements in machine learning by combining. Through the experiment, the proposed predictive techniques are validated, and the results of the experiment predicted the chance of successful film with about 95% of accuracy.

• Journal of Korea Society of Industrial Information Systems
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• v.21 no.1
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• pp.83-92
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• 2016

This paper is intended for small businesses, and small-scale empirical analysis of the peripheral region has a research model of the relationship between consulting factors that are studied in various aspects of the existing and business performance. In other words, a model that is presented in the study with reference to the existing verification as to whether any association exists between management consulting factors and business performance targets in wonju region auto parts production enterprises. Consulting factors were modeled separately by the consumer and supplier factors as business performance and financial performance were divided into non-financial performance, we designed the model parameters as set by the corporate culture. Research consulting consumer factors and supplier factors business performance (financial and non-financial) showed that having a significant impact on corporate culture, set as a parameter also having a positive effect on business performance It showed that.

• International Commerce and Information Review
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• v.16 no.2
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• pp.185-198
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• 2014

The purpose of this paper is to examine a causal relationship and interaction among payment of education expenses, economic growth, imports and exports. The results of 'the Granger causality test' suggest that payment of education expenses are affected by imports and exports; and the other factors are not related. In addition, payment of education expenses and the relationship among variables confirmed by IRF show that payment of education expenses has a minus(-) effect on exports at the beginning and then it turns into plus(+) as a certain time passes. On the other hand, it has a minus(-) effect on imports at the beginning, and this gradually changes to zero(0). Lastly, it turns out that it has a plus(+) effect on GDP. It is therefore estimated that the demand for high-quality manpower is expected to grow and new investments for education to rise with increases in imports and exports with initial acceleration. The findings show that government education investment in foreign languages and research manpower must take precedence in order to meet the demand for high-quality manpower.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.10 no.6
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• pp.126-139
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• 2011

In the traditional four-step travel demand models, each step is sequentially conducted following the model estimation at the previous step. The accuracy of the following model is partly dependent on whether the model at the former stage was properly established or not. Therefore, trip generation, which is the first step in this conventional model, has great effects on the modeling process and forecasting results. Linear regression models for trip generation of Seoul Metropolitan Area might increase the forcasting errors, since a variety of land-use characteristics are not considered. Hence, in this study, zonal factors such as socioeconomic and land use variables are included to improve the elaboration of trip generation. Comparing the %RMSE with the existing models, which contain bigger errors in the zones highly based on the secondary and tertiary industries than residence-based, the trip generation models including those variables seem more appropriate overall.

• Proceedings of the Korea Water Resources Association Conference
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• 2015.05a
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• pp.641-641
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• 2015

수자원 관리의 새로운 패러다임으로 스마트워터그리드가 이슈화되고 있다. 스마트워터그리드는 현재 직면해 있는 물 문제를 ICT기술을 활용하여 효율적으로 관리 및 운영할 수 있는 기술이다. 가뭄과 홍수 등을 대응하기 위한 분산형 수자원, 그리고 수량과 수질등의 통합 관리를 지향하는 물관리 패러다임과 ICT와 물산업을 융복합화하여 양방향 실시간 운영을 통한 네트워크 구성, 그리고 대규모 수원개발과 장거리 수송방식으로부터 지역단위의 부존된 수자원인 다중수원을 효율적으로 활용하고, 이들 수원의 최적 블랜딩 기술 및 멀티워터루프를 이용한 수요자 중심의 물관리에 초점을 맞추고 있다. 이에 본 연구에서는 지역의 부존된 수자원을 효율적으로 관리하기 위한 운영지수를 산정함으로써 지역의 평상시 물관리 운영과 상수공급차단, 다중수원에 오염물질 유입, 가뭄발생 등 비상시 상황에 물관리가 원활히 이루어지도록 하였다. 스마트워터그리드에서 사용되는 물관리 운영지수는 비상시 지역간 플랫폼에 정상적으로 물공급이 어렵거나, 예상되어 유량 확보가 필요시 원활하게 유량 확보가 가능하도록 주변 지역간의 운영지수를 산정하여 최적의 조건을 도출하여 우선순위를 시나리오에 나타내어 사용자가 플랫폼에 물공급이 가능하도록 제시한 운영지수이다. 물관리 운영지수는 중회귀분석 기법을 이용하여 종속변수에 선형적인 영향을 미치는 유량, 수질, 이송거리, 전력비용, 경제적인 영향 등을 고려하여 종속변수의 값을 예측하고 통계적인 기법으로 유량, 수질, 이송거리, 전력비용, 경제적인 영향 등에 대한 장래추정치를 부여하여 회귀모델을 구축하여 물관리 운영지수를 산정하였다. 이를 활용하여 평상시에는 물수요 공급량을 정확히 관리하여 지역간의 수자원 불균형을 해소하고 비상시에는 상황을 대처하여 지역의 물부족 문제를 해소할 수 있을 것으로 판단된다.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.20 no.3
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• pp.617-631
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• 2019

In the four-step demand model, a gravity mode is used most commonly at the trip distribution stage. The purpose of this study was to develop a new friction factor that can express the accessibility property as a single friction factor to compensate for the variable limits of the gravity model parameters (travel time, travel cost). To derive a new friction factor, a new friction factor was derived using the space syntax that can quantify the characteristics of the urban space structure, deriving the link-unit integration degree and then using the travel time and travel distance relationship. Calibration of the derived friction factor resulted in a similar level to that of the existing friction factor. As a result of verifying the various indicators, the explanatory power was found to be excellent in the short - and long - distance range. Therefore, it is possible to derive and apply the new friction factor using the integration index, which can complement the accessibility beyond the limit of the existing shortest distance, and it is believed to be more advantageous in future utilization.

• Journal of Digital Convergence
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• v.16 no.11
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• pp.89-96
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• 2018

In modern society, efforts to improve quality of life and happiness are emphasized compared to the past when economic growth was emphasized. The government has been implementing various policies to realize the happiness of the people through culture. The purpose of this study is to investigate the effect of Cultural Arts on the improvement of the happiness index of Seoul citizens by dividing them into demand (enjoyment) and supply side by setting Cultural Arts as independent variable, unlike existing limited surveys or literature surveys, under the control of change, the temporal range was set for more than 10 years and then analyzed quantitatively by panel analysis. The results showed that the demand for cultural arts affects positively on the improvement of happiness index of Seoul citizens, but the supply of cultural arts had a meaningless effect. In order to improve the happiness index of the citizens of Seoul through supply, it is necessary to supplement the existing space and to promote cultural demand through differentiated cultural arts programs aimed at diverse classes but also the policy implication that cultural indifference groups and active participation of cultural underprivileged groups should be increased.

• Journal of Korea Technology Innovation Society
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• v.16 no.3
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• pp.605-629
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• 2013

The aim of this study is analyzing the factors and performance related to the entry control mode when a SME advances into the global market. For this, the strategic factor of the SME was divided into the enterprise capabilities consisting of technology commercial capability, internal capability, and global capability of enterprise and information capabilities that are the capabilities on the global market and on the advanced technology. In the empirical study, a total of 27 variables that include the control variables and the financial and non-financial variables as a performance variable was used. The hypothesis was also established for analyzing the effect of the entry strategies on the entry control mode and the effect of the mode on performance. Logistic regression was conducted for verifying the hypothesis, and Multiple regression analysis and T-test were carried out on the additional analysis related to the performance.

• 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.