• Journal of KIISE
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• v.42 no.9
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• pp.1090-1099
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• 2015

The concept of Cloud Service Brokerage (CSB) has been introduced as a result of the expansion of the cloud-computing paradigm. Cloud services that provide similar functionality are registered with a CSB. A CSB intermediates cloud services between cloud users and providers. However, there are differences in the price and performance offered by each of the cloud providers. Thus, cloud users have difficulty in finding suitable services to use. Therefore, a CSB is required in order to provide an approach for cloud services to fulfill the requirements of cloud users. In this paper, we propose a virtual cloud bank architecture that includes both a Service Analysis Model (SAM) that can be used to specify and analyze various cloud services and a requirement analysis method that can be used to collect and analyze the cloud user requirements. The VCB architecture that is herein proposed can be used as a reference architecture to provide user-centric cloud services.

• The Journal of the Korea Contents Association
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• v.18 no.9
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• pp.433-440
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• 2018

I investigated whether network structure of legislators affects legislative performance in a cosponsorship network. I presented the theoretical basis with network closure and structural holes, and analyzed the network in the 19th National Assembly of Republic of Korea. In the directed and weighted network, each tie means that cosponsors support the bill sponsors proposed. The performance was measured by the number of initiatives and the ratio of reflected legislation, and the network structure was measured by size, density, hierarchy, and constraint. I found that the legislators with brokerage structure have a lot of initiatives in making connection with many legislators in various groups and the legislators with hierarchical structure have the higher ratio of reflected legislation with the continuous and strong support from the members of their group. I also found that the network of ruling party lawmaker is more hierarchical than the network of opposition lawmaker.

• The Journal of Information Systems
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• v.26 no.3
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• pp.91-118
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• 2017

Purpose The purpose of this research is to investigate the effect of social capitals on organizational knowledge sharing characteristics and individual innovation activities in community of practice (CoP) of manufacturing company. Design/methodology/approach For this purpose, we divide social capitals as three dimensions, i.e. structural, relational, and cognitive dimension. Structural dimension also consists of closure and Brokerage. Relational social capital is defined as trust about colleagues, superior authorities, and organization. Then, cognitive social capital is defined as a shared understanding among individuals, such as a shared language and codes within CoP. Knowledge Sharing is defined as quantity and quality of shared knowledge. We also defines the cause and effect relationships among social capitals, organizational knowledge sharing characteristics, and individual innovation activities in CoP of manufacturing company as follows. The social capitals will have positive effects on quality of shared knowledge. Then the quality of shared knowledge will have positive effects on the individual innovation activities. This paper tested the validity of these hypothesized casual effects and the sub-hypothesized causal relationships. For the purpose, we used the Partial Least Squares (PLS) for analyzing the causal relationships. Findings Our empirical results show that social capitals of CoP mostly have effects on organizational knowledge sharing characteristics (quantity and quality of shared knowledge) and knowledge sharing activities also have effects on individual innovative activities in the workplace. In this study, these result have a significant implication that a private company will be able to gain organizational innovative performance much better by strengthening CoP supporting activities.

• Journal of the Korea Society of Computer and Information
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• v.18 no.5
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• pp.103-111
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• 2013

This paper provide a framework for an IGILMS(internet-based global integrated logistics management system) which can access and mediate cargo transportations among small- and medium-sized domestic/international logistics corporations as regards cargo, registration and search for space, public tender and negotiation, contract, payment and safety-guarantee, transportation through the internet, wireless communication means, or smart phone etc. In addition, we describe a model to provide customized services in the B2B e-market for IGILMS and the structure and the control of its fulfillment process, and provide technical architecture of the IGILMS for an internet-based global logistics management system. To validate an efficiency of the proposed system, we develop a simulation model and analyze the performance of the proposed system.

• Asia-Pacific Journal of Business Venturing and Entrepreneurship
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• v.12 no.2
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• pp.21-29
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• 2017

Stock investment becomes one of the most popular investments in these days, and the ultimate goal of investors in the stock market is to maximize profits and minimize losses, in order to achieve this, investors will select based on investment information. namely, the information about the company which we interest is essential to stock investors. Also, investors are affected by their propensity to invest according to their attitude toward risk. With these situations, this research tried to show the private investors' actual performance of Investment by studying individual investors' propensity and Information explore. The purpose of this study is to analyze the effect of investors' propensity and information search on investment satisfaction. The questionary method required some sample surveys. The data of the practical analysis was carried out with the on-line researching method. The researching time was from the 1st of Dec. 2016 to the 15th of Dec. 2016. Of the 357 questionnaires submitted, 7 were deemed inappropriate or incomplete; thus, 350 questionnaires were used in the final analysis of the study. For analysis methodology, this research is using SPSS 21.0 along with analytic techniques, such as implementation of basic statistical analysis, reliability, and regression analysis. The practical analysis results are as follows; Among the investment propensities, profit propensity, analytical propensity, and investment propensity has a significant effect on investment performance. On the other hand, brokerage firm information, firm accounting information, private information has a statistically significant effect on investment performance. Finally, we confirmed the mediating role of investment sentiment.

• Journal of Digital Convergence
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• v.11 no.5
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• pp.159-168
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• 2013

This study analyze the business efficiency of securities company based on the 2011 performance of 29 securities firms which engage in domestic investment brokerage by applying a combination model of BSC and DEA. And we evaluate business state focused on efficiency which is based on logical system of BSC as business innovation method. The analysis of result is that companies with high customer efficiency index appeared that business efficiency composite index tended to be higher and we identified that customer perspective have an important factor to calculate business efficiency composite index of korea security company. In addition, based on the results of the efficiency analysis we analyze correlation analysis between traditional financial ratio and business efficiency composite index. We confirmed that company of high business efficiency level in terms of BSC have a good record in terms of profitability. BSC-DEA combination model expect to be utilized in security industry sector as well as other industrial sectors as good business indicator to determine the business efficiency and to be used a model can be evaluated the integrated firm valuation of tangible and intangible assets.

• Asia-Pacific Journal of Business Venturing and Entrepreneurship
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• v.7 no.3
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• pp.65-73
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• 2012

Microfinance has been an important tool for the economic growth and poverty alleviation. But the success factors and risk factors have not been synthesized in academic literature. This article has paid attention to success factors and potential risk of the Grameen Bank. Grameen Bank methodology is almost the reverse of the conventional banking methodology. Conventional banking is based on the principle that the more you have, the more you can get. Founder of Grameen Bank, Professor Yunus pointed out that, "The least you have the highest you have the priority to receive a loan". On the basis of theoretical literature, there have been different kinds of success factors of microfinance observed in this paper. Key success factors of Grameen Bank are like these: innovation, strict administrative structure, adaptation and learning practice, incentive system. Complementary services such as business consulting and brokerage will contribute to borrowers' economic performance development.

• Journal of Intelligence and Information Systems
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• v.26 no.1
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• pp.119-133
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• 2020

Fama asserted that in an efficient market, we can't make a trading rule that consistently outperforms the average stock market returns. This study aims to suggest a machine learning algorithm to improve the trading performance of an intraday short volatility strategy applying asymmetric volatility spillover effect, and analyze its trading performance improvement. Generally stock market volatility has a negative relation with stock market return and the Korean stock market volatility is influenced by the US stock market volatility. This volatility spillover effect is asymmetric. The asymmetric volatility spillover effect refers to the phenomenon that the US stock market volatility up and down differently influence the next day's volatility of the Korean stock market. We collected the S&P 500 index, VIX, KOSPI 200 index, and V-KOSPI 200 from 2008 to 2018. We found the negative relation between the S&P 500 and VIX, and the KOSPI 200 and V-KOSPI 200. We also documented the strong volatility spillover effect from the VIX to the V-KOSPI 200. Interestingly, the asymmetric volatility spillover was also found. Whereas the VIX up is fully reflected in the opening volatility of the V-KOSPI 200, the VIX down influences partially in the opening volatility and its influence lasts to the Korean market close. If the stock market is efficient, there is no reason why there exists the asymmetric volatility spillover effect. It is a counter example of the efficient market hypothesis. To utilize this type of anomalous volatility spillover pattern, we analyzed the intraday volatility selling strategy. This strategy sells short the Korean volatility market in the morning after the US stock market volatility closes down and takes no position in the volatility market after the VIX closes up. It produced profit every year between 2008 and 2018 and the percent profitable is 68%. The trading performance showed the higher average annual return of 129% relative to the benchmark average annual return of 33%. The maximum draw down, MDD, is -41%, which is lower than that of benchmark -101%. The Sharpe ratio 0.32 of SVS strategy is much greater than the Sharpe ratio 0.08 of the Benchmark strategy. The Sharpe ratio simultaneously considers return and risk and is calculated as return divided by risk. Therefore, high Sharpe ratio means high performance when comparing different strategies with different risk and return structure. Real world trading gives rise to the trading costs including brokerage cost and slippage cost. When the trading cost is considered, the performance difference between 76% and -10% average annual returns becomes clear. To improve the performance of the suggested volatility trading strategy, we used the well-known SVM algorithm. Input variables include the VIX close to close return at day t-1, the VIX open to close return at day t-1, the VK open return at day t, and output is the up and down classification of the VK open to close return at day t. The training period is from 2008 to 2014 and the testing period is from 2015 to 2018. The kernel functions are linear function, radial basis function, and polynomial function. We suggested the modified-short volatility strategy that sells the VK in the morning when the SVM output is Down and takes no position when the SVM output is Up. The trading performance was remarkably improved. The 5-year testing period trading results of the m-SVS strategy showed very high profit and low risk relative to the benchmark SVS strategy. The annual return of the m-SVS strategy is 123% and it is higher than that of SVS strategy. The risk factor, MDD, was also significantly improved from -41% to -29%.

• The Journal of Industrial Distribution & Business
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• v.1 no.1
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• pp.23-31
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• 2010

In this study, market orientation affects the real estate transaction and about the various parameters examined, the real estate transactions, market orientation and intensity of competition in the market upheaval and the impact was seen on the results can be summarized as follows. First, market orientation and about the relationship between real estate transactions were examined. Each variable of customer satisfaction information generation, information dissemination, information was used for the reaction. Among them, the dissemination of information, information about the reaction produces a lot better the customer satisfaction was the result. In other words, the dissemination of information and availability of information to real estate transactions, the more you can improve customer satisfaction. While the information does not appear to be generated as a result of the impact of market orientation when the first phase of the creation of market information and the customer's needs and preferences of current and future information and external factors affecting them to gather information about It is difficult to assess realistically can be seen. This is both our customers and dealers in real estate purchase or trade items for the exact targets, but the general approach the start of trading because by necessity. Therefore, a clear standard for real estate deals in and nine minutes to all sellers of real estate purchases through a process of communication to enable effective approach should be. Second, market orientation and about the relationship between real estate transactions were examined. The information for each variable in re-creating transactions, information dissemination, information was used for the reaction. Variable affects all the information creation, dissemination of information, information about the reaction the better the deal re-done show that two can be frequent. In other words, information generation, information dissemination and utilization of information to real estate transactions, the more customers the added responsibilities of the re-trade can be seen. Third, the relationship between market orientation and in the real estate market upheaval of environmental factors on the relationship between gender were examined. Each variable of customer satisfaction information generation, information dissemination, information was used for the reaction. Among them, the dissemination of information, information about the reaction produces a lot better the customer satisfaction was the result. In other words, the dissemination of information, depending on the market upheaval and the availability of information to raise the real estate can increase customer satisfaction. Fourth, market orientation and environmental factors in the relationship between real estate transactions and about the relationship between competition intensity was investigated. The information for each variable in re-creating transactions, information dissemination, information was used for the reaction. Variable affects all the information creation, dissemination of information, information about the reaction the better the deal re-done show that two can be frequent. In other words, information generation, information dissemination and utilization of information and the higher intensity of competition or unyounghameusseo ttaemaewoo active real estate transactions to provide our customers the added responsibilities of the re-trade can be seen. If more comprehensive, market orientation, according to real estate transactions and environmental factors affecting the performance was also different. Abundance of information about the current real estate it is true that the accuracy and reliability, and real estate, and are unsure about the expected benefits. So you want to trade to provide accurate information to customers and markets change rapidly and competition is severe, with more information if you have reliable information to the customer must supply can increase trading performance. Guarantee of future customer transactions and can provide valuable information and research needs to be differentiated based on the provision of real estate information should be done to achieve profitability will be a cow brokerage.

• Journal of Intelligence and Information Systems
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• v.20 no.2
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• pp.59-71
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• 2014

System trading is becoming more popular among Korean traders recently. System traders use automatic order systems based on the system generated buy and sell signals. These signals are generated from the predetermined entry and exit rules that were coded by system traders. Most researches on system trading have focused on designing profitable entry and exit rules using technical indicators. However, market conditions, strategy characteristics, and money management also have influences on the profitability of the system trading. Unexpected price deviations from the predetermined trading rules can incur large losses to system traders. Therefore, most professional traders use strategy portfolios rather than only one strategy. Building a good strategy portfolio is important because trading performance depends on strategy portfolios. Despite of the importance of designing strategy portfolio, rule of thumb methods have been used to select trading strategies. In this study, we propose a SVM-based strategy portfolio management system. SVM were introduced by Vapnik and is known to be effective for data mining area. It can build good portfolios within a very short period of time. Since SVM minimizes structural risks, it is best suitable for the futures trading market in which prices do not move exactly the same as the past. Our system trading strategies include moving-average cross system, MACD cross system, trend-following system, buy dips and sell rallies system, DMI system, Keltner channel system, Bollinger Bands system, and Fibonacci system. These strategies are well known and frequently being used by many professional traders. We program these strategies for generating automated system signals for entry and exit. We propose SVM-based strategies selection system and portfolio construction and order routing system. Strategies selection system is a portfolio training system. It generates training data and makes SVM model using optimal portfolio. We make $m{\times}n$ data matrix by dividing KOSPI 200 index futures data with a same period. Optimal strategy portfolio is derived from analyzing each strategy performance. SVM model is generated based on this data and optimal strategy portfolio. We use 80% of the data for training and the remaining 20% is used for testing the strategy. For training, we select two strategies which show the highest profit in the next day. Selection method 1 selects two strategies and method 2 selects maximum two strategies which show profit more than 0.1 point. We use one-against-all method which has fast processing time. We analyse the daily data of KOSPI 200 index futures contracts from January 1990 to November 2011. Price change rates for 50 days are used as SVM input data. The training period is from January 1990 to March 2007 and the test period is from March 2007 to November 2011. We suggest three benchmark strategies portfolio. BM1 holds two contracts of KOSPI 200 index futures for testing period. BM2 is constructed as two strategies which show the largest cumulative profit during 30 days before testing starts. BM3 has two strategies which show best profits during testing period. Trading cost include brokerage commission cost and slippage cost. The proposed strategy portfolio management system shows profit more than double of the benchmark portfolios. BM1 shows 103.44 point profit, BM2 shows 488.61 point profit, and BM3 shows 502.41 point profit after deducting trading cost. The best benchmark is the portfolio of the two best profit strategies during the test period. The proposed system 1 shows 706.22 point profit and proposed system 2 shows 768.95 point profit after deducting trading cost. The equity curves for the entire period show stable pattern. With higher profit, this suggests a good trading direction for system traders. We can make more stable and more profitable portfolios if we add money management module to the system.