• Korean Journal of Construction Engineering and Management
• /
• v.16 no.5
• /
• pp.77-85
• /
• 2015

The Hedonic Pricing model is the predominant approach used today to model the effect of relevant factors on real estate prices. These factors include intrinsic elements of a property such as floor areas, number of rooms, and parking spaces. Also, The model also accounts for the impact of amenities or undesirable facilities of a property's value. In the latter case, euclidean distances are typically used as the parameter to represent the proximity and its impact on prices. However, in situations where multiple facilities exist, multi-colinearity may exist between these parameters, which can result in multi-regression models with erroneous coefficients. This research uses Variance Inflation Factors(VIF) and Ridge Regression to identify these errors and thus create more accurate and stable models. The techniques were applied to apartments in Guro-gu of Seoul, whose prices are impacted by subway stations as well as a public prison, a railway terminal and a digital complex. The VIF identified colinearity between variables representing the terminal and the digital complex as well as the latitudinal coordinates. The ridge regression showed the need to remove two of these variables. The case study demonstrated that the application of these techniques were critical in developing accurate and robust Hedonic Pricing models.

• Journal of Korean Society for Atmospheric Environment
• /
• v.28 no.6
• /
• pp.656-665
• /
• 2012

Recently, yearly production of SRF (Solid Recovered Fuel) as an alternative fuel has been rapidly increasing because of the limited waste disposal, rise in oil prices and reduction of greenhouse gas emission. However, SRF using facilities are excluded from the National Air Pollutant Emission Estimation because SRF using facilities are not yet included among the SCC (Source Classification Code). The purpose of this research was to estimate the emission and emission factor of SRF using facilities' PM and $NO_x$, in order to investigate whether or not they are included in the National Air Pollutant Emission Estimation. The emission factors of SRF using facilities' PM and $NO_x$ are calculated as 0.216 kg/ton, and 3.970 kg/ton, and the emission was estimated based on the yearly total SRF usage of 2011. The results above was 18.7% for PM and 12.8% for $NO_x$ emissions from combustion facility (SCC2) in manufacturing industry combustion (SCC1) of CAPSS. If CAPSS estimate the emission by adding SCC on unlisted SRF in case of Boiler (SCC3) fuel, both PM and $NO_x$'s emissions would increase by 15.8% and 11.3% compare to the emissions for the existing combustion facility. As a result, emissions caused by SRF should be considered when calculating the National Air Pollutant Emission Estimation. In addition, further researches to develop emission factor and improve subdivided SCC should be done in the future, for the accurate and reliable estimation of National Emission.

• The Research Journal of the Costume Culture
• /
• v.25 no.1
• /
• pp.1-15
• /
• 2017

Social commerce is a kind of internet shopping mall in which consumers purchase the products with other consumers through mutual interactions including the development of SNS(social network service). Social commerce has expanded rapidly as a mainstream online shopping mall over the past five years driving consumers to purchase more fashion products providing the cheaper prices than open market internet shopping mall. The purpose of this study is to identify the important parameters of social commerce characteristics and consumer characteristics that affect repurchase intention and word-of-mouth intention. A 221 survey questionnaire was distributed to men in their 20's and 30's who live in Seoul metropolitan area. The data were analyzed utilizing Cronbach's ${\alpha}$, factor analysis, and regression analysis using the SPSS 18.0 program. The results revealed, first, that in terms of social commerce characteristics, three variables(website reputation, interactivity, and product scarcity) influenced repurchase intention. Among them, website reputation identified as the most important factor influencing repurchase intention and word-of-mouth intention. Second, with regard to consumer characteristics, interest and a tendency toward impulse buying affected the repurchase intention, and interest and internet shopping experience have influenced the word-of-mouth intention. Among three variables interest in social commerce identified as the key factor affecting both repurchase intention and word-of-mouth intention. The results of the study provide the practical implications and suggest the business strategies to enhance social commerce in the future by identifying the key social commerce characteristics and consumer characteristics that influence male consumers' buying behaviors.

• Korean Journal of Construction Engineering and Management
• /
• v.9 no.5
• /
• pp.214-226
• /
• 2008

Construction delay caused considerable losses to project parties. Avoiding construction delays is important to save costs for project stakeholders. The main objective of this paper is to identify major causes of construction delays of apartment construction projects in Vietnam. Sixteen causes of delay were identified through a questionnaire survey of 166 professionals. Factor analysis was employed to categorize these causes. The results of the survey revealed the main causes of delay of apartment projects in Vietnam are: (1) owner's and contractor'S financial difficulties; (2) lack of experienced contractors; (3) late delivery of materials; (4) late construction site handover; (5) owner's late payments for completed works; (6) low bid prices; (7) inappropriate construction method; and (8) defective works and unnecessary reworks. Factor analysis uncovered that causes of delay can be grouped under five categories labeled the five INs: incompetence, ineffectiveness, inadequateness, inapplicableness and inconceivableness. Comparative analysis between the Vietnam construction industry (VCI) and the Korea construction industry (KCI) has been performed to infer valuable lessons for researchers and practitioners in the VCI and the KCI. Comparative analysis indicated that main causes of delay in the VCI somewhat differ from main causes of delay in the KCI. However, "contractor'S financial difficulties", "late construction site handover", "unnecessary rework", "incapable designers", "site clearance difficulties" are common causes of delay in the VCI as well as the KCI. The findings of this research can be used as a guideline to overcome problems in the VCI as well as in other construction industries. Since Korea has emerged as the first largest foreign investor in Vietnam, the results of this study may be useful not only to practitioners and researchers in Vietnam but also to participants in Korea.

• Asia Pacific Journal of Business Review
• /
• v.1 no.2
• /
• pp.37-62
• /
• 2017

To analyze the effects of R&D expenditure on the firm value of Korean firms, we classified portfolios based on R&D activity levels. After that, we conducted a time-series analysis to assess excess returns from the portfolios. To carry out such an analysis, an empirical analysis of excess returns in the capital market was performed by using the monthly earning rate of stocks from 2000 to 2013. The purpose of this research is to provide basic data on investment to stakeholders in the capital market by analyzing the effects of R&D on the firm value and to overcome scholarly limitations by offering a new model of analysis. The criteria for classifying the portfolios were based on R&D expenditure levels. The analysis models follow the Fama-French Three-Factor Model and the Carhart Four-Factor Model. The analyses results are as follows. Extrapolating monthly profit rates based on R&D expenditure levels, portfolios with low R&D expenditures showed higher earning rates than those with high R&D expenditures. This suggests that high R&D expenditures did not translate into high earning rates. The investor depreciates the R&D expenditures related profitability and the possibility of success in the market, leading to falls in stock prices and a failure to give a positive effect on the firm value. Our research differs from the previous investigations as we carried out an empirical analysis based on the actual investors' attitudes about R&D expenditures and how these can generate excess earnings. Our research results show that the data related to R&D expenditure are not reflected fully in the market.

• New & Renewable Energy
• /
• v.8 no.4
• /
• pp.21-29
• /
• 2012

The extensible supply of New & Renewable energy resources desperately needs to counter the high dependence on imported energy, recent high oil prices and the Climate Change Conference, and the government has operated the 'Renewable Portfolio Standard' (RPS) as one of the renewable energy policy from 2012. By analyzing the operation case of combined heat and power plant using the woodchip biomass, we drew the price of wood chip fuel, plant capacity factor, electricity selling price, heat selling price and LCOE value. After analyzing the economic feasibility of 3MWe combined heat and power plant based on the operating performance, the minimum of economic feasibility has appeared to be secured according to the internal rate of return (IRR) is 6.34% and the net present value (NPV) is 3.6 billion won as of 20 years life time after installation, and after analyzing the cases of the economic feasibility of the price of wood chip, plant capacity factor, electricity and heat selling price are changed, the economic feasibility is valuable when the price of wood chip is over 64,000 won/ton, NPV is minus, and the capacity factor is above 46.9%, the electricity selling price is 116 won/kWh and the heat selling price is above 75,600 won/Gcal. When going over the new installation hereafter, we need the detailed review of the woodchip storage and woodchip feeding system rather than the steam-turbine and boiler which have been inspected many times, the reason why is it's hard to secure the suitable quality (constant size) of woodchip by the lack of understanding about it as a fuel because of the domestic poor condition and the calorific value of woodchip is seriously volatile compared with other fuels.

• Proceedings of the KSR Conference
• /
• 2011.10a
• /
• pp.2860-2865
• /
• 2011

Recently, the number of passengers using urban railway has been increased by reasons of the reductions of car use due to high fuel prices and the enlightenment about the environment. Above all, the noise and the vibration coming from the friction between the wheel and the rail of trains in operation which is not only a factor that hinders riding comforts but causes civil complaints. Furthermore, the noise has become social issues from tightening the relevant regulations by the government since January 2010. Although ballasted tracks were constructed on urban railways at the time of opening, they have been changed into slab tracks because slab tracks require much less maintenance. However, in view of sound absorptivity of track, slab tracks have 10 times less capability than ballasted tracks(ballasted track : 0.5~0.6/slab tracks : 0.06) results more noise than that of ballasted tracks as much as 3dB(A) since slab tracks emit more reflection noise. Therefore, in order to minimize reflection noise on slab tracks, noise abatement system has been developed as a national R&D program to apply on-site test. It is assumed that the construction technology developed in this study can be used not only as basic data for the on-site test for the noise reduction in urban railway but as an efficient construction method.

• Journal of the East Asian Society of Dietary Life
• /
• v.10 no.4
• /
• pp.311-319
• /
• 2000

This study was to investigate eating behaviors and food preferences of the worker at transportation business in Daegu areas by work site. The survey was performed by questionnaires from July 13 to August 25, 1999 against 353 of males. As a general factor, the subjects of survey were male drivers in their forties to fifties. Their education level was middle school (46.5%) and high school (47.3%) diploma. The subjects were composed of 44.2% of city workers and 55.5% of suburban workers. This study showed that the city workers eat three meals per day with high percentage (92.9%) and a large number of suburban workers (21.3%) eat two meals only. Most of the subjects 782.% responded that their diet life were irregular due to the property of their job. The food preferences of most of workers (94.9%) were Korean food rather than any other foods. Frequency of eating-out was much higher in city drivers than in suburban drivers. They considered taste of food firstly and the prices of food secondly, but the nutritional value of food was considered with a very low percentage (14.7%). Their favorite menu turned out to be the Korean style one-dish food, of those one-dish Koran food, they preferred rice or soup to the noodles. These results suggest that he nutritional education against the workers at transportation business is needed to set the proper menu considering the characteristics of the preference each group of workers.

• Korean Journal of Agricultural Science
• /
• v.24 no.1
• /
• pp.63-74
• /
• 1997

This study is aimed at identifying the value of marginal products(VMP) of agricultural labor, capital and land. The resources are the major portion of input costs of agricultural projects. To appraise economic feasibility of agricultural projects, the real value of the resources would be estimated by VMP of the inputs rather than by distorted actual market prices such as rural wages, rent and interest. To convert the market wage rate into shadow wage rate, covertion factor of 0.90 would be appicable based on the study results. To evaluate the right of way and compensation, VMP of land is recommendable to apply in land pricing rather than actural land rent prevailing in rural area which has been underrated on account of labor shortage and difficulty of farming. Discount rate as a opportunity cost of capital should be applied 7-8% considering the VMP of capital and interest rate of foreign loan from IBRD and ADB. For the successful appraisal of the agricultural projects, the recommendation of this study would be applied in the future.

• Culinary science and hospitality research
• /
• v.23 no.1
• /
• pp.37-47
• /
• 2017

The number of delivery app users and their social impact have increased along with the number smartphone users. Accordingly, the present study attempted to suggest a method to improve the service quality of delivery apps for relevant businesses and researchers by determining the influences of delivery app usage factors on customer satisfaction and reuse intention. The present study distributed and collected questionnaires through on- and offline surveys targeting males and females in their 20s in the Daejeon area. The results of the regression analysis showed that the influence of delivery app usage factors on customer satisfaction was 43.8%, and informativeness, payment and safety, usefulness, and convenience were found to influence the increased satisfaction with the delivery apps. The influence of delivery app usage factors on customers' reuse intention was 37.3%, and among the four usage factors, informativeness and payment and safety were found to be the main factors for increasing the reuse intention. As providing more accurate information is a means to increase customer satisfaction and reuse intention by improving the service quality of the delivery apps, new menus and prices should be rapidly updated.