• Journal of the Korean Data and Information Science Society
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• 제16권2호
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• pp.283-288
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• 2005

Value at Risk(VaR) has been proven useful in finance literature as a tool of risk management(cf. Jorion(2001)). This article is concerned with introducing VaR to various Korean financial time series. Five daily data sets with sample period ranging from 2000 and 2004 such as KOSPI, KOSPI 200, KOSDAQ, KOSDAQ 50 and won-dollar exchange rate are analyzed using GARCH modeling and in turn VaR is obtained for each data.

• 대한교통학회지
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• 제20권3호
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• pp.41-52
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• 2002

본 연구는 예비타당성조사 등 최근 빈번하게 행해지는 도로사업의 투자분석에서 화물교통에 대한 고려가 미흡하다는 문제제기와 더불어, 그 이유 중의 하나로 화물자동차의 운송시간가치에 대한 자료가 부족하다는 데에 문제의식을 갖고 진행하였다. 지금까지 우리나라에서 화물운송의 시간가치를 산정한 사례가 소수 있으나 국토공간을 전체로 한 전국단위의 시간가치이거나 철도, 해운 등 도로교통과 관련이 적은 교통수단을 고려한 경우 또는 화물 자동차 운전자의 임금수준을 근거로 산정 하였기 때문에 도로사업의 투자분석에 보편적으로 적용할 수 있는 시간가치를 제시하지는 못하였다고 평가된다. 본 연구는 연구결과의 실용성 측면에 주안점을 두고 화물운송의 시간 가치를 대도시권과 지역간 등 공간적 범위에 따라 산정하고, 운송수단도 자가용화물자동차와 영업용화물자동차로 단순화시켜 화물자동차를 대표하는 단일화된 시간가치를 제시하였다. 화물자동차의 운송시간가치를 산정한 결과 국토공간 전체를 대상으로 한 전국단위의 시간가치는 37,472원/대·시간이며, 대도시권을 대상으로 산정한 시간가치는 53,449원/대·시간, 그리고 지역간을 대상으로 산정한 시간가치는 29,397원/대·시간으로 나타났다. 이로써 화물운송의 시간가치를 전국단위로 산정하고 공간적 구분이 없이 단일의 값을 적용한다면 도로사업의 투자분석에 필요한 시간가치 편익의 산정에 상당한 차이가 발생할 수도 있다는 것이 입증되었고, 공간적인 범위를 고려한 시간가치를 적용할 필요성이 제기되었다.

• International Journal of Quality Innovation
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• 제8권1호
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• pp.1-14
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• 2007

The Six Sigma and Lean Production methodologies suggest that creating value for customers is the objective of a production process or an organisation. In the production context, "added value" dominates the discussion about the creation of value to customers. However, "added value" is often only defined conceptually or discussed at a strategic level, and the link between added value and customer value has not yet been well conceptualised. Therefore, the purpose of the paper is to develop a methodology to measure added value in order to complement the existing performance measures in Six Sigma and Lean Production by conceptualising the link between customer value and added value. The conceptual link "confirms" that quality, time, and costs are the elements of added value, which are transformed into a metric to express customer value. The implementation of the metric recommends the adoption of Lean (Six) Sigma and Lean Accounting (Activity Based Costing), which thus implies that "leanness" is an important "feature" of added value.

• 한국지능시스템학회:학술대회논문집
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• 한국퍼지및지능시스템학회 2003년도 ISIS 2003
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• pp.338-341
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• 2003

Recently, the chaotic method is employed to forecast a near future of uncertain phenomena. This method makes it possible by restructuring an attractor of given time-series data in multi-dimensional space through Takens' embedding theory. However, many economical time-series data are not sufficiently chaotic. In other words, it is hard to forecast the future trend of such economical data on the basis of chaotic theory. In this paper, time-series data are divided into wave components using wavelet transform. It is shown that some divided components of time-series data show much more chaotic in the sense of correlation dimension than the original time-series data. The highly chaotic nature of the divided component enables us to precisely forecast the value or the movement of the time-series data in near future. The up and down movement of TOPICS value is shown so highly predicted by this method as 70％.

• 산업경영시스템학회지
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• 제30권2호
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• pp.89-98
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• 2007

In this paper the economic value of weather forecasts is valuated for profit-oriented enterprise decision-making situations. Value is estimated in terms of monetary profits (or benefits) resulted from the forecast user's decision under the specific payoff structure, which is represented by a profit/loss ratio model combined with a decision function and a value score (VS). The forecast user determines a business-related decision based on the probabilistic forecast, the user's subjective reliability of the forecasts, and the payoff structure specific to the user's business environment. The VS curve for a meteorological forecast is specified by a function of the various profit/loss ratios, providing the scaled economic value relative to the value of a perfect forecast. The proposed valuation method based on the profit/loss ratio model and the VS is adapted for hypothetical sets of forecasts and verified for site-specific probability of precipitation forecast of 12 hour and 24 hour-lead time, which is generated from Korea meteorological administration (KMA). The application results show that forecast information with shorter lead time can provide the decision-makers with great benefits and there are ranges of profit/loss ratios in which high subjective reliability of the given forecast is preferred.

• 대한가정학회지
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• 제40권6호
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• pp.69-83
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• 2002

This study examined the effects of demographic variables on buying behavior, and investigated buyers'perceived value and risk perception of the internet shopping mall. The sample was collected by a department store in Daegu, and it included 1,732 individuals using the Cyber Mall. Research methods used in this study were simple statistics, t-test and ANOVA. The buyers perceived values through the internet shopping mall were classified into five categories-price, time, convenience, intrinsic attributes, reliability and the risk perception also was classified such as the overall purchasing process, quality of products, exposure of the personal information, delivery system, refund and exchange. The major findings of this study were 1) most important categories affecting their buying behavior were the value of convenience and following values in order were time, price, reliability, intrinsic attributes. 2) the risk perception were overall purchasing behavior, quality of products, exposure of personal information, delivery, and refund & exchange in order. 3) age of buyers, buying experience on the internet shopping mall, and gender were the important factors affecting the buyers'perceived value and risk. 4) the study also, showed that according to the variety of products, buyers perceived the value and risk differently, for example, the price was the most important perceived value in case of food product. The implication of the study is to strategically suggest how to enhance the buyers'perceived value and diminish perceived risk of different products.

• 농촌계획
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• 제21권4호
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• pp.127-137
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• 2015

This Study attempted to comprehend difference between hiker and non-hiker's sense of place value at Namhansanseong Provincial Park. Especially, it was analyzed after visitors, who were divided into local residents & tourists and first time visitors & repeat visitors. Out of 600 visitors, who were over 19 years old, participated in the survey, 587 responses were used for data analysis. Consequently, Sense of place value at Namhansanseong Provincial Park were classified into three factors: Health Culture, Ecology Environment, and Connectedness. Hikers feel higher value on promotion of health, relaxation, environment than non-hikers. Among hikers, local residents feel higher value on ecology environment and connectedness than tourists. Among non-hikers, however, they have no difference between local residents and tourists, only repeat visitors and first time visitors. On this result, possibility of resident participation management on natural environment and trail was considered, and when the program, which is for raising cultural and traditional value, would develop, increasing number of repeat visitor should be considered as a high priority.

• 한국시뮬레이션학회:학술대회논문집
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• 한국시뮬레이션학회 2004년도 춘계학술대회 논문집
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• pp.109-117
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• 2004

In this paper, we consider the aortic sinus baroreceptor, which is the most representative baroreceptor sensing the variance of pressure in the cardiovascular system, and propose heart activity control model to observe the effect of delay time in heart period and stroke volume under the regulation of baroreflex in the aortic sinus. The proposed heart activity baroreflex regulation model contains electric circuit sub-model. We constituted the time delay sub-model to observe sensitivity of heart activity baroreflex regulation model by using the variable value to represent the control signal transmission time from the output of baroreflex regulation model to efferent nerve through central nervous system. The simulation object of this model is to observe variability of the cardiovascular system by variable value in time delay sub-model. As simulation results, we observe three patterns of the cardiovascular system variability by the time delay, First, if the time delay over 2.5 second, aortic pressure and stroke volume and heart rate is observed nonperiodically and observed. Finally, if time delay under 0.1 second, then heart rate and aortic pressure-heart rate trajectory is maintained in stable state.

• Journal of Biosystems Engineering
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• 제38권3호
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• pp.180-184
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• 2013

Purpose: This study explored the factors influencing heating value in the process of torrefaction of water hyacinth. Methods: Torrefaction was applied with three temperature settings (200, 300, $400^{\circ}C$) and three time settings (1, 2, 3 h) using small electric heaters (11.3L of holding volume). This study investigated the heating values with the washing process and process factors influenced the torrefaction. In addition, this study compared the heating values in washed and unwashed samples and suggested the optimal conditions for increasing heating value. Results: Torrefaction increased the heating value by 8.18 ~ 30.04%. Comparing heating values of each condition, the optimal temperature for torrefaction was $300^{\circ}C$ and holding time was 1 hour. The washing process increased the heating value by 19 ~ 27%. The heating value of the sample treated at $300^{\circ}C$ for three hours was 4310.80 kcal/kg, which was greater than the first class wood pellet of 4300 kcal/kg. Conclusions: This study proved that the torrefaction and washing process increased the heating value of water hyacinth. Therefore, water hyacinth is expected to be an eco-friendly biomass which substitutes for wood pellet.

• 국제학술발표논문집
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• The 4th International Conference on Construction Engineering and Project Management Organized by the University of New South Wales
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• pp.453-458
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• 2011

The construction industry's importance to nation building, economic empowerment, and contributions to global commerce cannot be over emphasised. However, poor productivity, accidents, rework, time and cost overruns, and client dissatisfaction have characterised the industry performance in a multi-dimensional way. The central issue in this particular research is the seemingly inadequate achievement of optimum performance in the construction process, either with respect to value for money for the client and the entire construction supply chain or value in terms of the utility derived from built assets in spite of efforts by government and governmental bodies such as the Construction Industry Development Board (cidb) to increase industry performance. Therefore, based upon an extensive review of related literature, the paper reports on effects and causes of non-value adding activities in the construction industry in general, and South African construction in particular. The research findings indicate that activities that can be referred to as non-value activities are not only prevalent, but they can also be held responsible for performance related issues in terms of cost, time, quality and health and safety (H&S) in construction; and the exploration of pluralism in the research methodology may result in a robust model based upon the system dynamics approach. Therefore, the study suggests that there is major scope for value optimisation in the construction process especially in terms of availability and implementation of interventions, which have not only proven successful in other industries, but are also adaptable in the construction industry context.