• The Journal of the Korea Contents Association
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• v.13 no.8
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• pp.128-140
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• 2013

The cause of traffic accidents and driver behavior is affected by psychological factors, because the behavior of drivers and pedestrians, and to identify the psychological linkage analysis to explore improvements in service design approaches are becoming increasingly important. Service design is a service-oriented development methodology that make invisible and intangible elements into visible and higher-value. Accordingly, through design thinking to action for development of products and a pleasant road environment were studied for school zone by discovering underlying issues to resolve in terms of service design. First, survey of domestic road psychological and behavioral problems were derived through the analysis of the causes of traffic accidents and researched the concept of school zones by analyzing the ideas. To reduced the width of the lane manipulate the speed of the vehicle and to cross the crosswalk safely. In order to encourage the flow of vehicle traffic, new solutions are proposed by offering robot traffic lights, graphic design of crosswalk, space, and the fence and convergence public design and services.

• Journal of the Korean Institute of Gas
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• v.24 no.6
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• pp.34-46
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• 2020

In order to supply stable natural gas in the future, it is necessary to forecast the demand in advance and secure the quantity of supply. In this paper, we propose a method of estimating the demand function of industrial natural gas, which is the core of the increase of domestic natural gas demand in the future. The cross-sectional data of 304 domestic industries were used to estimate the demand function of the industrial natural gas, and the effect of industry specific characteristics such as capital investment, manufacturing cost. Finally, the least absolute deviation estimation method which is robust to outliers and does not assume the homogeneity of the error term and the normality, And the results were derived. In addition, the economic value of industrial city gas was estimated using the price elasticity of industrial city gas. Therefore, it can be seen that the continuous expansion and supply of city gas to the industrial sector is beneficial at the national level, and the government needs to promote expansion through the industrial city gas support policy.

• The Journal of the Korea Contents Association
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• v.21 no.11
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• pp.320-332
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• 2021

This paper investigates the influence of stock-level left-tail risk, which is defined using Value-at-Risk(VaR) estimates of past one-year daily stock returns, in the expected stock returns in the Korean stock market. Our results are summarized as follows: First, monthly-constructed zero-cost portfolios that buy (shortsell) the highest (lowest) left-tail risk decile in the previous month exhibit an average monthly return (called left-tail risk premium) of -2.29%. Second, Fama-MacBeth cross-sectional regressions suggest that left-tail risk in the previous month shows significant and negative explanatory power over return in this month, after controlling for various firm characteristics such as firm size, B/M, market beta, liquidity, maximum daily return, idiosyncratic volatility, and skewness. Third, the stocks with larger recent month loss have lower returns in the next month. Fourth, the magnitude of left-tail risk premium is negatively related with lagged market-level volatility. These results support the hypothesis from a perspective of behavioral finance that the overpricing of stocks with left-tail risk is attributed to the investors' underreaction to it.

• 한국노년학
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• v.32 no.4
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• pp.1101-1118
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• 2012

The purpose of this study is to examine which factors determine self-rated health(SRH) among Korean elderly focusing on gender differences. To achieve this purpose, it uses the Hallym Longitudinal Study of Aging, wave 4 in 2009. Participants aged 65 and over from wave 4 were selected(N=986, male 407, female 579). From wave 4, all variables were selected except for respondents' education which was from wave1. In analyses, $x^2$ or t-test were conducted to examine whether independent variables significantly differ by SRH. Then, since a dependent variable consisted of two categories-being healthy or not being healthy, logistic regressions were run. What makes gender differences in the link of independent variables to SRH were 75-84 age group, education, and IADLs. For females, 75-84 age group rated their health as worse compared to 65-74 age group, but this age group did not have significant effect on SRH for males. Females graduating from junior high school were more likely to higher rate their health compared to their counterparts. However, education was not significant for males. Instrumental activities of daily living(IADLs) is one of variables affecting SRH by making gender differences. Female having problems with IADLs were more likely to be significantly negatively rate their health compared to males. Through focusing on age, education, IADLs making gender difference in evaluating health, governments needs to support males and females differently.

• KDI Journal of Economic Policy
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• v.9 no.1
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• pp.43-67
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• 1987

산업구조(産業構造)의 고도화과정(高度化過程)에서는 고용흡수력(雇傭吸收力)이 감소(減少)하는 양적측면(量的側面)의 과제(課題)와 기술인력(技術人力)의 수요(需要)가 상대적으로 증가(增加)하는 질적측면(質的側面)의 인력정책과제(人力政策課題)가 동시에 야기(惹起)된다. 본(本) 논문(論文)에서는 이러한 여건변화(與件變化)에 대응(對應)하는 정책과제(政策課題)를 도출(導出)하기 위하여 인력수요(人力需要)의 결정요인(決定要因)을 실증분석(實證分析)하였다. 거시분석(巨視分析)에서는 1970~84년(年) 기간(期間)의 연간(年間) 시계열자료(時系列資料)를 이용(利用)하여 노동수요함수(勞動需要函數)를 추정(推定)하여 산업별(産業別) 결정요인(決定要因)을 비교분석(比較分析)하였으며, 미시분석(微視分析)에서는 섬유(纖維) 자동차(自動車) 전자산업(電子産業)에서 임의추출(任意抽出)한 200개(個) 표본기업(標本企業)에 대한 횡단면자료(橫斷面資料)를 이용(利用)하여 기업(企業)의 인력수요행태(人力需要行態)를 분석(分析)하였다. 산업별(産業別) 노동수요(勞動需要) 분석결과(分析結果)를 보면, 자본비용(資本費用)에 대한 노동비용(勞動費用)의 상대적상승(相對的上昇)이 노동수요(勞動需要)를 감소(減少)시켜 왔으나, 고용(雇傭)은 기본적으로 자본투자(資本投資)로부터 더 큰 영향을 받는 것으로 나타났으며, 또한 자본(資本)의 고용창출효과가(雇傭創出效果), 특히 제조업부문(製造業部門)에서, 시간(時間)의 경과(經過)에 따라 감소(減少)하는 것으로 분석(分析)되었다. 미시분석결과(微視分析結果)를 보면, 전문대졸(專門大卒) 및 고졸학력(高卒學力) 근로자(勤勞者)에 대한 수요(需要)는 중소기업(中小企業)에서, 대졸(大卒) 및 중졸이하학력(中卒以下學歷) 근로자(勤勞者)는 대기업(大企業)에서 흡수(吸收)하려는 것으로 나타났으며, 생산요소중(生産要素中) 노동(勞動)에 대한 투자우선순위(投資優先順位)는 자동차산업(自動車産業)에서 높게 나타났으며, 숙련기능인격(熟練技能人格)에 대한 수요(需要)는 세 산업(産業) 모두 높게 나타났다.

• Journal of Korean Society of Transportation
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• v.26 no.1
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• pp.181-190
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• 2008

This study intended to provide the inherent characteristics of weak pedestrian including walking speed and perception-reaction time and to propose pedestrian signal timing models considering those characteristics. To collect the relevant data, field studies were conducted in virtual crosswalk environments. Walking speed were found to be 0.63 m/s and 0.57 m/s for children and the elderly, respectively. However, the elderly had higher perception-reaction time than children. By considering these characteristics, two pedestrian signal timing models were developed. Sensitivity analysis results showed that the models can produce reasonable ranges of pedestrian signal time. The data in this paper can be used for future references, and the mobility of weak pedestrian may be improved by applying the models suggested in this paper.

• The Journal of the Korea Contents Association
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• v.12 no.12
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• pp.385-394
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• 2012

This study investigates whether earnings management behavior of chaebol firms differ from that of non-chaebol firms. The ownership structure of chaebol firms is characterized by the dominance of one largest shareholder and his family members who typically participate in the management of the firm directly or indirectly and influence most of the important management decision. This study adopts the random effect model and the hausman and talyor model, using a panel of 5092 firm-year over a period from 1991 to 2010 to control for potential heterogeneity and endogeneity that may cause sever bias. This study finds that there is no difference in accrual based earnings management level between chaebol firms and non-chaebol firms. However, chaebol firms appeared to engage less real earnings management that is known to negatively affect future earnings and share prices. The results are consistent when controlling for potential heterogeneity and endogeneity in the hausman and taylor model. The results may be of interest to various stakeholders, policy makers, standard setters and academic researchers.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.36 no.2
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• pp.259-268
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• 2016

The core strategy of transit oriented development (TOD) is to promote high density mixed land use around railway stations. Case studies in advanced countries show that provision of policies for comprehensive maintenance of pedestrian facilities around railway station spheres is being pursued with efficacy. In spite of the importance placed on integrated pedestrian maintenance, domestic construction of integrated pedestrian infrastructure around railway station spheres lacks direction. Thus, there is a clear need for an evaluation standard that can provide the foundation for judgments on TOD improvement. This research proposes a network model that consolidates the interior of the station as well as its surrounding areas to determine the ease of pedestrian flow for effective TOD evaluation. The model considers the railway station and surrounding areas as an assembled network of pedestrian flow. The path chosen by the pedestrian is defined as the optimal degree of inconvenience, and expands on Wardrop's User Equilibrium (1952). To assess the various circumstances that arise on pedestrian facilities including congestion of the pedestrian pathway, constrained elevator capacity, and wait at the crosswalk, a variational inequality based pedestrian equilibrium distribution model is introduced.

• Journal of Korean Society of Transportation
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• v.27 no.1
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• pp.191-200
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• 2009

This study develops composite indicators that is capable of estimating QOS (Quality of Service) of pedestrians by enhancing estimation for Level of Service in present transporting spaces for pedestrians that merely concerns quantitative indicators such as pedestrian flow rate, pedestrian stoppage. This paper conducts survey questionnaire to collect data. It utilizes AHP(Analytic Hierarchy Process) and ANP(Analytic Network Process). The main results show that: first, ANP is better analytic methods than AHP due to the fact that pedestrians feel repetition when they judge level of service. Second, qualitative factors such as pedestrian behaviors, maintenance, scenary for pedestrians and environments should be considered. Importance of qualitative factors is higher in residential area than other areas. I expect that using qualitative indicators and quantitative indicators is appropriate in order to estimate pedestrians' QOS.

• Journal of Digital Convergence
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• v.17 no.8
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• pp.1-13
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• 2019

This study examined the effect of digital technologies on adolescent mental health; attention deficit, aggression, depression. Furthermore, we investigated the role of parenting style and peer attachment as they might have effects on digital technologies. Using two-wave longitudinal data, we conducted longitudinal analysis from the Korean Children and Youth Panel Survey done in 2015 and 2016. Results showed that computer and internet usage for learning purpose has a positive effect on mental health, while computer games and social media have negative effects. Also, the positive effects of learning on depression indicated stronger in adolescents who felt less affection from their parents. On the other hand, the negative effects of computer games and social media could be moderated by both parenting style and peer attachment. Implications of these results and directions for future research are discussed.