• KSCE Journal of Civil and Environmental Engineering Research
• /
• v.35 no.6
• /
• pp.1329-1338
• /
• 2015

This article aims to develop model for the right policy Tools available from the cause analysis regarding the regional differences of subway modal split in Seoul metropolitan area. This allows two major factors of the most influential subway modal split to be proved and Portfolio Analysis is conducted. The results are as follows. Firstly, the two primary factors affecting subway modal split were shown as subway adjacent area and local line bus. It signifies that expansion of subway adjacent area, establishing the number of the subway stations and increase of local line bus are required in order to improve a diminishing subway modal split. Following that, pattern of the improvement to strengthen better subway connections are classified according to the two areas which are Concentration Area of Improvement in Subway Station Area (CAISSA) and Concentration Area of Improvement in Local Bus (CAILB). Our study revealed that Ganbukgu, Seodaemungu, Geumcheongu, and Gwanakgu were selected as the area of CAILB and Songpagu, and Junggu were selected as the area of CAISSA. As all things are considered, transportation policy makers should be taken into account in the two main factors driven by our study according to types in order to enhance the future subway share proportion.

• Agribusiness and Information Management
• /
• v.11 no.1
• /
• pp.10-26
• /
• 2019

This study is exploratory research on a relationship between changes in cultivated area of major crops and farm income by regions. We investigated level of income, volatility of income, and migration of suitable region by climate changes as factors influencing changes in cultivated area. Research processes are as follows. First, we classify the regions where cultivated areas are expanded or reduced through the trends of cultivated area by region and crop during recent 10 years. Second, we compare the changes in income related factors between groups during the same periods. Finally, the results from portfolio analysis show changes in stable income-based optimal crops. From these procedures, we found that the changes in cultivated area are not simply explained by income-related factors. In cases of vegetables, however, we also found that high volatility of income could contribute to reduce cultivated area of the crops. The results from portfolio analysis are not always consistent in all of cases. This means that crop selection can be decided by other factors than stable income.

• Journal of Korean Home Economics Education Association
• /
• v.19 no.1 s.43
• /
• pp.15-33
• /
• 2007

The purpose of this study is to find the effect of improvement in student's learning attitude when applying portfolio, which is one of the ways for the performance's assessment suggested as an alternative of traditional assessment for the instruction of Home Economics subject. The results of this study were as follows; 1. We have developed the Portfolio materials; teaching and learning plans, the paper of activities of the class, materials of the instructions, and assessment materials from the instruction of total 13 times in the unit of 'making short pants'. 2. The instruction,'Making short pants' with applying portfolio, is very effective in terms of changing student's learning attitude positively - pride, self-confidence, interest, conscience of purpose, motivation for achievement, focus surroundings, self-study, friendship among classmate and etc. 3. The result of analyzing students 'thoughts shows that the majority over 90% of the students showed the positive attitude toward applied portfolio instruction. Here are the reasons that 'it's helpful to study', 'it can be focused better on the instruction', 'it give them satisfaction and couidence' and 'it can be increased abilities studying by oneself'. on the other hand, the negative side of the instruction applied portfolio is that it requires too much time to prepare portfolio materials. there is pressure because of a lot of assignments to do. Based on this result, we are expecting to increase student's interest in the middle school class of Technology and Home Economic and also to achieve development of the method of teaching and learning to enhance student's learning attitude.

• Journal of Technology Innovation
• /
• v.5 no.1
• /
• pp.15-43
• /
• 1997

This paper investigates empirically the relationship between various business portfolio properties (particularly technological properties) and chaebol's performance using data on the 50largest chaebols in Korea. In addition to the traditional indexes to measure diversification such as entropy index, we calculated inter-industry technological similarity using R'||'&'||'D expenditure data by industry and 1990 Input-output Table in korea, and obtained chaebol-level technological relatedness and internal transaction proportion from chaebols' business profile, inter-inustry technological similarity and 1990 input-output table. We applied factor analysis on 13 business portfolio property indexes and showed that they could be grouped into 3 dimensions. diversification scope, inter-business relatedness and degree of vertical integration. In this paper, using 50 largest chaebols' financial data (1989-1994), we analyzed empirically the effect of business portfolio properties on ROS(Return On Sales) which is conventional index for firm performance and on TFP(Total Factor Productivity) growth which is a pure measure of firm performance. To utilize the advantage of panel data, FEM(Fixed Effect Model) and REM(Random Effect Model) were used. The empirical result shows that the entropy index as a measurement of inter-business relatedness in not significant but technological relatedness index is significant. OLS estimates on pooled data were considerably different from FEM or REM estimates on panel data. By introducing interaction effect among the three variables for business portfolio properties, we obtained three findings. First, only VI(Vertical integration) has a significant positive correlation with ROS. Second, when using TFP growth as an dependent variable, both TR(Technological Relatedness) and VI are significant and positively related to the dependent variable. Third, the interaction term between TR and VI is significant and negatively affects TFP growth, meaning that TR and VI are substitutes. These results suggest strategic directions on restructuring business portfolio. As VI is increased, chaebols will get more profit. A higher level of either TR or VI will increase TFP growth rate, but increase in both TR and VI will have a negative effect on TFP growth. To summarize, certain business portfolio properties such as VI and TR can be considered "resources" themselves since they can affect profit rate and productivity growth. VI and TR have a synergy effect of change in profit rate and productivity growth. VI increases ROS and productivity growth, while TR increases productivity growth representing a technological synergy effect.t.

• Journal of the Korean Data and Information Science Society
• /
• v.26 no.6
• /
• pp.1479-1494
• /
• 2015

Since the Markowitz's mean-variance framework for portfolio analysis, the topic of portfolio optimization has been an important topic in finance. Traditional approaches focus on maximizing the expected return of the portfolio while minimizing its variance, assuming that risky asset returns are normally distributed. The normality assumption however has widely been criticized as actual stock price distributions exhibit much heavier tails as well as asymmetry. To this extent, in this paper we employ the genetic algorithm to find the optimal portfolio under the Value-at-Risk (VaR) constraint, where the tail of risky assets are modeled with the generalized Pareto distribution (GPD), the standard distribution for exceedances in extreme value theory. An empirical study using Korean stock prices shows that the performance of the proposed method is efficient and better than alternative methods.

• The Journal of the Korea Contents Association
• /
• v.19 no.6
• /
• pp.204-213
• /
• 2019

This study examines the ePortfolio structure of IT company design interns and the differences among companies in 'Cofolios' site for employment of design major students. First, we examine the common configuration steps of ePortfolios [1. Project Brief${\rightarrow}$2-1. Investigation and Analysis${\rightarrow}$2-2. Strategy development${\rightarrow}$2-3. Virtualization, Final Design${\rightarrow}$2-4. Presentation, Evaluation, and Improvement${\rightarrow}$3. Read More]. Secondly, all the sub-items used in the ePortfolio were organized into words and classified into 6 stages. Finally, this was analyzed by majors and companies. Through this, the interns of the IT companies can [2-2. Strategy development] and that they are actively utilizing the 'connectivity' attribute linking the links. In addition, interns confirmed that the ePortfolio was structured differently depending on their major and the desired company.

• The Korean Journal of Applied Statistics
• /
• v.34 no.1
• /
• pp.39-56
• /
• 2021

Many researches have been done on portfolio optimization since Markowitz (1952) published a diversified investment model. Markowitz's mean-variance portfolio optimization problem is established under the assumption that the distribution of returns follows a normal distribution. However, in real life, the distribution of returns does not follow a normal distribution, and variance is not a robust statistic as it is heavily influenced by outliers. To overcome these potential issues, mean-shortfall portfolio model was proposed that utilized downside risk, shortfall, as a risk index. In this paper, we propose a perturbation method that uses the shortfall as a risk index of the portfolio. The proposed portfolio utilizes an adaptive Lasso to obtain a sparse and stable asset selection because it can reduce management and transaction costs. The proposed optimization is easily applicable as it can be computed using an efficient linear programming. In our real data analysis, we show the validity of the proposed perturbation method.

• Journal of Korea Technology Innovation Society
• /
• v.14 no.spc
• /
• pp.1187-1208
• /
• 2011

This research aims to propose a systematic approach to identify emerging technology-product portfolio for small and medium enterprises (SMEs). Firstly, operational definition of emerging technology for SMEs is presented. Secondly, research framework is suggested and case study to show usefulness of the newly proposed framwork is analyzed. In detail, reference patent set which represent company's capabilities and business area are constructed. The research constructs patent data set for bibliometric analysis using reference patent set and citing patents to 2nd level. Clustering (expert judgement) and keyword based bibliometric approach are used. Then, cluster activity index (AI) and relevance index (RI) comparing with reference patent set are estimated. With emerging technology-product portfolio using AI and RI, a firm can identify emerging technology-product area and monitoring area.

• Journal of the Korean Data and Information Science Society
• /
• v.23 no.1
• /
• pp.151-159
• /
• 2012

This paper proposes to develop multi-currencies portfolio strategy using principal component analysis (PCA) and logistic regression (LR) in foreign exchange market. While there is a great deal of literature about the analysis of exchange market, there is relatively little work on developing trading strategies in foreign exchange markets. There are two objectives in this paper. The first objective is to suggest portfolio allocation method by applying PCA. The other objective is to determine market timing which is the strategy of making buy or sell decision using LR. The results of this study show that proposed model is useful trading strategy in foreign exchange market and can be desirable solution which gives lots of investors an important investment information.

• Journal of KIBIM
• /
• v.8 no.4
• /
• pp.1-12
• /
• 2018

Nowadays, BIM(Building Information Modeling) technology has been slowly accepted and developed around the world, making smart construction possible. Many countries are also actively promoting the comprehensive application of BIM and changing the traditional construction methods of the construction industry. This study reviews foreign and domestic literature reviews on BIM application barriers and smart construction applications, providing a theoretical basis for Chinese construction enterprises to reduce or eliminate BIM application barriers. Based on the common feature of policies or strategies that promote the development of smart construction in developed countries, such as the United States, the United Kingdom, and Singapore, the deficiencies of China's smart construction policies for construction enterprises are analyzed. Moreover, according to the literature review of the development status of China's construction industry, the SWOT analysis matrix of China's smart construction strategy is obtained. Finally, based on the SWOT matrix analysis results, combined with the development status of China's construction industry and the obstacles faced by smart construction, the portfolio strategies and recommendations for the development of smart construction are proposed in this work. These portfolio strategies and recommendations can provide a reference value for construction enterprises.