• Journal of Intelligence and Information Systems
• /
• v.16 no.4
• /
• pp.67-84
• /
• 2010

In terms of business, forecasting is a work of what is expected to happen in the future to make managerial decisions and plans. Therefore, the accurate forecasting is very important for major managerial decision making and is the basis for making various strategies of business. But it is very difficult to make an unbiased and consistent estimate because of uncertainty and complexity in the future business environment. That is why we should use scientific forecasting model to support business decision making, and make an effort to minimize the model's forecasting error which is difference between observation and estimator. Nevertheless, minimizing the error is not an easy task. Case-based reasoning is a problem solving method that utilizes the past similar case to solve the current problem. To build the successful case-based reasoning models, retrieving the case not only the most similar case but also the most relevant case is very important. To retrieve the similar and relevant case from past cases, the measurement of similarities between cases is an important key factor. Especially, if the cases contain symbolic data, it is more difficult to measure the distances. The purpose of this study is to improve the forecasting accuracy of case-based reasoning approach using fuzzy relation and composition. Especially, two methods are adopted to measure the similarity between cases containing symbolic data. One is to deduct the similarity matrix following binary logic(the judgment of sameness between two symbolic data), the other is to deduct the similarity matrix following fuzzy relation and composition. This study is conducted in the following order; data gathering and preprocessing, model building and analysis, validation analysis, conclusion. First, in the progress of data gathering and preprocessing we collect data set including categorical dependent variables. Also, the data set gathered is cross-section data and independent variables of the data set include several qualitative variables expressed symbolic data. The research data consists of many financial ratios and the corresponding bond ratings of Korean companies. The ratings we employ in this study cover all bonds rated by one of the bond rating agencies in Korea. Our total sample includes 1,816 companies whose commercial papers have been rated in the period 1997~2000. Credit grades are defined as outputs and classified into 5 rating categories(A1, A2, A3, B, C) according to credit levels. Second, in the progress of model building and analysis we deduct the similarity matrix following binary logic and fuzzy composition to measure the similarity between cases containing symbolic data. In this process, the used types of fuzzy composition are max-min, max-product, max-average. And then, the analysis is carried out by case-based reasoning approach with the deducted similarity matrix. Third, in the progress of validation analysis we verify the validation of model through McNemar test based on hit ratio. Finally, we draw a conclusion from the study. As a result, the similarity measuring method using fuzzy relation and composition shows good forecasting performance compared to the similarity measuring method using binary logic for similarity measurement between two symbolic data. But the results of the analysis are not statistically significant in forecasting performance among the types of fuzzy composition. The contributions of this study are as follows. We propose another methodology that fuzzy relation and fuzzy composition could be applied for the similarity measurement between two symbolic data. That is the most important factor to build case-based reasoning model.

• Journal of Korea Port Economic Association
• /
• v.27 no.1
• /
• pp.263-280
• /
• 2011

The global financial crisis, triggered by the subprime mortgage crisis in 2007, has put the world economy into the recession with financial market turmoil. I tested whether variables were cointegrated or whether there was an equilibrium relationship. Also, Generalized impulse-response function (GIRF) and accumulation impulse-response function (AIRF) may be used to understand and characterize the time series dynamics inherent in economical systems comprised of variables that may be highly interdependent. Moreover, the IRFs enables us to simulate the response in freight to a shock in the USD/JPY exchange rate, Dow Jones industrial average index, Dow Jones volatility, Chinese Import volatility. The result on the cointegration test show that the hypothesis of no cointergrating vector could be rejected at the 5 percent level. Also, the empirical analysis of cointegrating vector reveals that the increases of USD/JPY exchange rate have negative relations with freight. The result on the impulse-response analysis indicate that freight respond negatively to volatility, and then decay very quickly. Consequently, the results highlight the potential usefulness of the multivariate time series techniques accounting to behavior of Freight.

• Journal of Venture Innovation
• /
• v.2 no.2
• /
• pp.127-140
• /
• 2019

A stock valuation on the tax law is based on the valuation by market price. But, unlike the listed stocks, the unlisted stocks mostly have the unclear market price. Accordingly, it is necessary to calculate the fair value which corresponds to the market price. The purpose of this paper is to examine the appropriateness of the complementary valuation method in the Inheritance Tax and Gift Tax Act and to provide suggestions for improvement. This study is intended to provide the problems and solutions relating to the valuation of unlisted stocks through analysis of foreign legal systems and actual disputes. When the actual profit/loss data are used to calculate the net profit/loss value on the present regulations, it has the different weight on the latest 3 years' net profits and losses uniformly. Therefore, to extend the range of unlisted stocks valuation and to show the independent and high professionalism of appraisal council not the subsidy appraisal agency of the National Tax Service, it is necessary to change the current rule that the commissioner of the National Tax Service unilaterally appoints the private members into the method of public offering.

• Journal of Internet Computing and Services
• /
• v.18 no.3
• /
• pp.71-83
• /
• 2017

In recent years, by utilizing the greatest strengths of process mining, the various research activities have been actively progressed to use auditing work of business organization. On the other hand, there is insufficient research on systematic and efficient analysis of massive data generated under big data environment using process mining, and proactive monitoring of risk management from audit side, which is one of important management activities of corporate organization. In this study, we intend to realize Hadoop-based internal audit integrated real-time monitoring system in order to detect the abnormal symptoms in prevent accidents in advance. Through the integrated real-time monitoring system for purchasing audit, we intend to realize strengthen the delivery management of purchasing materials ordered, reduce cost of purchase, manage competitive companies, prevent fraud, comply with regulations, and adhere to internal control accounting system. As a result, we can provide information that can be immediately executed due to enhanced purchase audit integrated real-time monitoring by analyzing data efficiently using process mining via Hadoop-based systems. From an integrated viewpoint, it is possible to manage the business status, by processing a large amount of work at a high speed faster than the continuous monitoring, the effectiveness of the quality improvement of the purchase audit and the innovation of the purchase process appears.

• Asia-Pacific Journal of Business Venturing and Entrepreneurship
• /
• v.15 no.4
• /
• pp.263-275
• /
• 2020

In the vortex of change, commonly referred to as the Fourth Industrial Revolution, Korea has a national task of changing the paradigm of economic growth from a chase-type economic structure to a leading one. The era has come when all resources of the country, as well as the government and businesses, must join in innovation and growth in order to maintain the pace of sustained economic development, and significantly advanced countries are stimulating members' innovation activities with various policies and systems as they enter the 21st century. South Korea is also making efforts to create an open creative space referred to as Makerspace or Fab Lab, to create an innovative voluntary environment for its citizens. This study explored factors that Makerspace, which is proliferating in Korea, should consider to secure development and sustainability as an innovation (start-up) space. Through prior research, openness and expertise were derived from the characteristics of Makerspace, and expert interviews confirmed that the capabilities lacking in Makerspace and the capabilities to be secured in the future are openness and professionalism. Also, specific components of openness and professionalism were presented through prior research, and implications for each subject's Makerspace were presented, such as openness, professionalism, and commercialization.

• Asian-Australasian Journal of Animal Sciences
• /
• v.22 no.8
• /
• pp.1140-1150
• /
• 2009

Forage diets provide good quality carcasses in sheep but very little is known in tropical goats. An experiment was designed with Creole male goats using grass-based systems to assess carcass yield, scores, cuts and composition. After weaning (84 d, 9.2 kg LW) two modes of forage feeding were compared with two replicates of each. Feeding groups were: PF for animals reared at pasture (n = 62) and IF when reared indoors (n = 60). Given that forage finishing will result in low ADG it appeared necessary to study different fattening lengths. The kids were equally divided into 4 groups: group A (n = 32), 4mo after weaning; group B (n = 32), 4mo after A; group C (n = 30), 3mo after B and group D (n = 28), 2mo after C. The animals grazed (in two sub-flocks) on irrigated tropical pastures managed in a rotational system (28 d of re-growth) at a mean stocking rate of 1,200 kg/ha/yr LW. The IF groups were reared in collective pens on a slatted floor (2 replicates of 7 or 8 kids each). They were fed the same stand of tropical grass (25% DM, 12% CP) as that of pasture that was cut daily and provided ad libitum. The ADG (-10%), the weights of omental fat (-60%) and fat in shoulder (-18%), the ultimate pH of carcass (-12%), the meat colour score (-24%), the ""parameter accounting for redness (12%) and the DM and lipid contents (-4%) were significantly lower (p<0.05) in PF than in IF, while the liver was heavier (+23%, p<0.05). Feeding conditions seemed to be similar, thus, differences could be related to gastrointestinal parasitism in the PF system and hypotheses are discussed. Increasing the fattening duration, resulted in significant difference (p<0.01) in many traits: the weights at slaughter and of carcass increased by 40% and 60% from groups A to D and consequently the weights of body compartments and carcass cuts (1.5 to 2.0 fold more). When the results were presented as percentage of empty body weight and carcass weight, these preliminary results (carcass weight 9kg and yield 53%, muscle proportion 70%) and qualitative parameters (low fat score 2/5, fat proportion 5%), seem to be a good incentive for the sector to develop a niche market to meet consumer lean meat expectations. The indoors system could be implemented where there was low availability of grazing areas or problems of dog attacks.

• Journal of the Korean Society for Marine Environment & Energy
• /
• v.15 no.2
• /
• pp.118-125
• /
• 2012

World population has increased rapidly following the industrial revolution, reaching 7 billion in 2012. Several forecasts estimate that this number will rise to about 8 billion in 2025. Improvements of living standards in developing nations have also raised resource and energy demands worldwide. In consequences, human beings have faced many global and urgent problems, such as global warming, water and food shortages, resource and energy crises, and so on. Many ocean utilization technologies for avoiding or reducing such big problems have been developed, for examples $CO_2$ ocean sequestration, seawater desalination, artificial upwelling, deepwater mining, and ocean energies. It is important, however, to assess such technologies from the viewpoints of sustainability and public acceptancy, since the aims of those technologies are to develop sustainable social systems rather than conventional ones based on fossil resources. Inclusive Marine Pressure Assessment and Classification Technology Research Committee (generally called IMPACT Research Committee) of Japan Society of Naval Architects and Ocean Engineers, has proposed Inclusive Impact Index "Triple I" as an indicator, which can predict both environmental sustainability and economical feasibility, in order to assess the ocean utilization technologies from the viewpoints of sustainability and public acceptancy. This index was considered by combining Ecological Footprint and Environmental Risk Assessment. The Ecological Footprint and the Environmental Risk Assessment are introduced in the first part of this paper. Then the concept and the structure of the Triple I are explained in the second part of this paper. Finally, the economy-ecology conversion factor in Triple I accounting is considered.

• Korean Journal of Microbiology
• /
• v.53 no.3
• /
• pp.156-162
• /
• 2017

Legionnaires' disease (LD) is a severe and potentially fatal pneumonia caused by colonization of human-made water system and subsequent aerosolization and inhalation of Legionella bacteria. A total of 147 Legionella strains was isolated from environmental water sources from public facilities in Gyeonggi-do, South Korea. The distribution of Legionella isolates was investigated according to facility type, and sample type. L. pneumophila was distributed broadly throughout Gyeonggi-do, accounting for 85.7% of the isolates, and L. pneumophila serogroup (sg) 1 predominated in all of the public facilities. L. wadsworthii predominated among non-L. pneumophila species. We performed comparative analyses of L. pneumophila sg 1 isolated from environment water of public facilities in Gyeonggi-do by pulsed field gel electrophoresis (PFGE) and sequence-based typing (SBT). Thirty-two isolates were classified into 22 types by PFGE and 9 sequence types (STs) by SBT and categorized into 3 groups. ST1 was the most prevalent sequence type and two STs obtained in this study had unique allelic profiles. The use of SBT data from different countries for epidemiology study of LD constitutes a technically uncomplicated and relatively easy method for strain subtyping, especially compared to other contemporary techniques.

• Journal of agricultural medicine and community health
• /
• v.37 no.2
• /
• pp.76-83
• /
• 2012

Objectives: The purpose of this study was to define the underserved emergency medical services (EMS) areas in Daejeon metropolitan city, as well as to identify their distinctive characteristics in public health perspectives. Methods: An underserved EMS area was operationally defined as an area in which it is difficult to arrive at an emergency medical center within 30 minutes. Using a cost-weighted distance algorithm with a geographic information system (GIS), the underserved EMS area was calculated. The characteristics of the underserved areas were analyzed by the Chi-square test. The SPSS statistical software package was used to perform the statistical analysis. All statistical tests were two-sided, and a p-value<0.05 was considered statistically significant. Results: Twelve administrative sectors ('Dong' in Korean) were included in the underserved areas, accounting for a population of approximately 8,100 citizens. The relationships between underserved EMS area and populations of agriculture, fishery, and forestry; citizens who are recipients of national basic livelihood security program; disabled; or aged 65 or older were statistically significant. Conclusion: It was found that 12 administrative sectors were included in the underserved EMS areas. Revealing underserved EMS areas using GIS analysis based on a cost-weighted distance algorithm of road data was an effective analytic method. However, as this study was confined to Daejeon City, South Korea, a nation-wide study should be performed to provide a more accurate conclusion.

• The Journal of Korean Institute of Communications and Information Sciences
• /
• v.31 no.5B
• /
• pp.456-477
• /
• 2006

Due to advances in wireless communication technology and increasing demand for various types of wireless access, cellular, WLAN, and portable internet(such as WiBro and IEEE 802.16) systems are likely to be integrated into a unified wireless access system. This expectation premises the availability of multi-mode handsets and cooperative interworking of heterogenous wireless access networks allied by roaming contracts. Under such environments, a user may lie in the situation where more than one wireless accesses are available at his/her location, and he/she will want to choose the 'best' access among them. In this paper, we define the 'best' access(es) as the access(es) that charges minimum cost while fulfilling the required QoS of wireless access, and address the problem of choosing the optimal set of accesses theoretically by introducing a graph representation of service environment. Two optimal selection algorithms are proposed, which individually consider cases where single or multiple wireless access can be supported by multi-mode handsets.