• Journal of the Korea Academia-Industrial cooperation Society
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• v.13 no.2
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• pp.615-627
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• 2012

The market penetration of the smart phones has brought significant changes to the related industries. As the mobile phone market as well as the smart phone application market are growing rapidly, competition among small-size application developers has become severe. However, due to the severe competition and expensive market entry costs, the developers argue that it is necessary to develope the applications from the perspective of the users. However, studies on application development from the users' perspectives are still in the early stages and they have not provided various approaches. Therefore, based on the Open Coding method of Ground Theory, this study collected data on applications review from related communities and blogs of Korean web portal sites, and identified indices which users consider important when they use the applications. In addition, we conduct a comparative analysis between those indices by calculating their frequency of exposure. As a result, a total of 30 sub-categories of indicators such as amusement, controllability, versatility and ease of use appeared to be predominant to users and those lower categories were grouped into five categories; sensibility, design, technology, price, and social skills. The results of this study suggest to the application developers the guidelines of user oriented design and development. It can be used to develop the evaluation tool for application usability.

• Journal of Intelligence and Information Systems
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• v.16 no.1
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• pp.71-92
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• 2010

As the use of trading systems increases recently, many researchers are interested in developing intelligent trading systems using artificial intelligence techniques. However, most prior studies on trading systems have common limitations. First, they just adopted several technical indicators based on stock indices as independent variables although there are a variety of variables that can be used as independent variables for predicting the market. In addition, most of them focus on developing a model that predicts the direction of the stock market indices rather than one that can generate trading signals for maximizing returns. Thus, in this study, we propose a novel intelligent trading system that mitigates these limitations. It is designed to use both the technical indicators and the other non-price variables on the market. Also, it adopts 'two-threshold mechanism' so that it can transform the outcome of the stock market prediction model based on support vector machines to the trading decision signals like buy, sell or hold. To validate the usefulness of the proposed system, we applied it to the real world data-the KOSPI200 index from May 2004 to December 2009. As a result, we found that the proposed system outperformed other comparative models from the perspective of 'rate of return'.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.37 no.4
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• pp.82-89
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• 2014

Recently, the mineral resource protection policies and regulations in production countries of natural resources including rare metals are becoming more stringent. Such environment makes which market has malfunction. In other word, those are not perfect or pure market. Therefore because each market of natural resources have special or unique characters, it is difficult to forecast their market prices. In this study, we constructed several models to estimate prices of natural resources using statistical tools like ARIMA and their business indices. And for examples, Indium and Coal were introduced.

• Korean Journal of Construction Engineering and Management
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• v.20 no.1
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• pp.124-132
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• 2019

Notwithstanding the crucial contribution of international construction industry in the national economy, previous studies on international construction contracts had mainly focused either on trend investigation or market share analysis at a point of time. Fundamentally, the international construction industry is fragmented due to its project-based nature, is heterogeneous that has to involve different firms from diverse fields, and tends to be dynamic according to macroeconomic conditions. Therefore, the combination of static and dynamic analyses is necessary to understand its underlying structure. This study analyzes the market structure of international construction contracts using the data of 9,173 projects awarded by Korean construction firms from 2000 to 2017. Industry-level performance data is analyzed both in static (market concentration) and dynamic (market mobility and instability) methods, and detailed methodology is also provided. Consequently, the static analysis result shows that the competition among Korean construction firms has been more intensified, and the dynamic analysis result indicates that market positions of Korean construction firms are unstable and vulnerable in most of the regions and the sectors. The combination of static and dynamic indices is found to be helpful to understand the underlying aspects of market structure and can be utilized as an effective strategic reference in the highly competitive market.

• Journal of the Korea Society of Computer and Information
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• v.19 no.12
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• pp.329-338
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• 2014

The paper chooses four trade competitiveness assessment indices to compare the international competitiveness of Computer and Information Service(C&IS) trade between South Korea, China and Japan. The results show that the competitiveness of China is the strongest, Japan secondary and Korea the weakest among the three countries. However, the competitiveness of Korea can be promoted the most quickly and it has exceeded Japan according to TC and NXRCA indices. Meanwhile, there was still a huge gap between the three countries and the two world strong countries-India and Ireland. The main findings of empirical research on influencing factors show that domestic market demand and trade opening degree are the two most important factors influencing the competitiveness of three-country C&IS trade. At the same time, improving the utilization of C&IS and realizing good interaction of C&IS trade and electronic information, communication and other relevant and auxiliary industries can also contribute to the competitiveness improvement.

• The Korean Journal of Financial Management
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• v.20 no.2
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• pp.181-200
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• 2003

Comovement of international stock market prices has been lately a major controversy in the global stock market. This paper explores whether the common trend has really existed among the US, Japan and Korea's stock markets using the econometric techniques such as VAR, VECM as applied. Pair of indices from the exchange market and the over-the-counter market in each country has been tested, and the exchange market only has been turned out that the common trend existed. The dynamic analyses using the Granger causality test, impulse response function, and the forecast error decomposition have followed to show that the US stock market has played some important role in the Korea and Japan's market in the exchange as well as in the OTC market. The results of the paper imply that the more careful investigation with respect to the co-integration may be necessary in the global market integration studies.

• Journal of Labour Economics
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• v.39 no.2
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• pp.113-139
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• 2016

The purpose of this study is to establish evaluation model that can explain marginal effects of baseball players of Korean Baseball Organization (KBO) on their team winnings in terms of productivity. We proposed econometric model with using variables that are provided from official homepage of KBO to overcome the complexity of mainly used productivity index: wins above replacement (WAR). Also, compare to the previous studies such as Scully(1974) or Krautmann(1999) that using limited indices of baseball stats, this study included 61 indices that are provided from official homepage of KBO. We estimated regression based WAR(RBWAR) by conducting panel regression with each team's statistics data of 2002 to 2014. As a results, RBWAR shows 0.869 correlation coefficient for batters and 0.882 for pitchers with WAR in 2014 that can be concluded that two indices shows similar results. From the results of estimation, we analyze the relationship between productivity and actual contract of free agent players in 2015 and it showed that teams have contracted reasonably.

• Korean Journal of Food Science and Technology
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• v.26 no.4
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• pp.453-458
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• 1994

43 Kinds of physicochemical characteristics of koji kochujang prepared by a standardized industrial process were determined and analyzed statistically during storage for 105 days at $37^{\circ}C$. The characteristics which showed significant correlation with storage period after preparation of kochujang were 12 items, which included sensory preference for flavor and taste, Hunter tristimulus values($L,\;a,\;b,\;{\{\delta}E$), HMF, capsanthin, formol nitrogen, threonine, water and water activity. Seven of the items were related with color attributes of kochujang. Especially, tristimulus values showed significant correlation with sensory preference for color of kochujang. In this regard, tristimulus values should be recommended as new quality indices of national standard for industry-produced koji kochujang. Means and standard deviations of tristimulus values of 27 kinds of industry-produced koji kochujang in the market were $28.21{\pm}1.48,\;a=9.37{\pm}2.54,\;b=4.35{\pm}2.19\;and\;{\delta}E=30.09{\pm}2.42.$.

• Preventive Nutrition and Food Science
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• v.12 no.4
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• pp.242-250
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• 2007

This study evaluated the storage stability of a variety of sauce products in the Korean market, determined primary quality indices for three typical products, and proposed functional relationships that are useful for determining shelf life at different temperatures. Most of the products examined were found to combine hurdles of low pH, low water activity, and the use of heat processing as methods for producing the required storage stability while maintaining the sensory quality of the products. For a meat extract solution produced for cold noodles (pH=4.3; $a_w=0.98$), the primary quality change determining shelf life was lipid oxidation, determined here by the TBA value. The primary quality index of a soybean paste seasoning mix (pH=4.0; $a_w=0.78$), which had a microbial load of 2.8 log (CFU/g), was a decrease in its pH. The primary quality index for a sandwich spread (pH=4.0; $a_w=0.88$) was changes in its surface color. The temperature dependence of changes in the primary quality indices can be described by the Arrhenius equation, which can estimate the shelf life at any arbitrary limit as a function of temperature. The activation energies for changes in the primary quality indices of the meat extract solution, the soybean paste seasoning, and the sandwich spread were 20.3, 27.2, and 43.5 kJ/mol, respectively.

• Journal of the Korean Institute of Landscape Architecture
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• v.30 no.3
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• pp.35-45
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• 2002

This research is related to the evaluation of rural amenities. Since the UR negotiations, the wave of market liberalization has brought many difficulties to the rural areas. This paper serves to identify a number of important elements such as socialization, cultural and ecological resources and investigate the viability of rural areas. The purpose of this study is to evaluate rural amenities by evaluation indices and establish planning direction of amenities for rural areas. The data have been collected by methods of a field survey and a questionnaire survey. The evaluation indices have been defined as socialization, safety, amenity and convenience by several researches. Villages have been divided into two groups. Seven(Shimchon, Ibaek, Muan, Dokpyong-li, Imchin-li Hyangyang-li, Wonwol-li) have been newly constructed, six(baeksa, Mokmyon, yongho-li, shindyae-li, hwangdun·songgae) have been redeveloped. There are considerable differences in the degree of satisfaction between he two groups. The results are as follows: 1) socialization is very necessary for amenities in rural villages. Especially the values of the resident's interactions and management of the village are most important in the preparation of an amenity plan in rural areas. So the plans and establishment of public facilities are requisite for the residents community. 2) The convenience of rural public facility plans is necessary for the improvement of the farmers'living conditions. For planning the rural villages, special regards are paid to characteristics of the village, such as the former place of residence and occupations. 3) Newly constructed village should improve their socialization and the redeveloped types should try to get a better life for amenity and safety, The residents of the redeveloped types show relatively high degree of satisfaction with indices of resident community, living convenience facilities, and management of village. On the contrary, amenity and safety are good in newly constructed types. This study has taken into consideration the characteristics of rural villages. It makes a contribution to the redevelopment of rural villages and improves amenities in rural villages. It is recommended that more studies classify the resources of rural areas and measure amenities which are significant to city dwellers in the future.