• Journal of Intelligence and Information Systems
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• v.25 no.3
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• pp.1-17
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• 2019

Because stock price forecasting is an important issue both academically and practically, research in stock price prediction has been actively conducted. The stock price forecasting research is classified into using structured data and using unstructured data. With structured data such as historical stock price and financial statements, past studies usually used technical analysis approach and fundamental analysis. In the big data era, the amount of information has rapidly increased, and the artificial intelligence methodology that can find meaning by quantifying string information, which is an unstructured data that takes up a large amount of information, has developed rapidly. With these developments, many attempts with unstructured data are being made to predict stock prices through online news by applying text mining to stock price forecasts. The stock price prediction methodology adopted in many papers is to forecast stock prices with the news of the target companies to be forecasted. However, according to previous research, not only news of a target company affects its stock price, but news of companies that are related to the company can also affect the stock price. However, finding a highly relevant company is not easy because of the market-wide impact and random signs. Thus, existing studies have found highly relevant companies based primarily on pre-determined international industry classification standards. However, according to recent research, global industry classification standard has different homogeneity within the sectors, and it leads to a limitation that forecasting stock prices by taking them all together without considering only relevant companies can adversely affect predictive performance. To overcome the limitation, we first used random matrix theory with text mining for stock prediction. Wherever the dimension of data is large, the classical limit theorems are no longer suitable, because the statistical efficiency will be reduced. Therefore, a simple correlation analysis in the financial market does not mean the true correlation. To solve the issue, we adopt random matrix theory, which is mainly used in econophysics, to remove market-wide effects and random signals and find a true correlation between companies. With the true correlation, we perform cluster analysis to find relevant companies. Also, based on the clustering analysis, we used multiple kernel learning algorithm, which is an ensemble of support vector machine to incorporate the effects of the target firm and its relevant firms simultaneously. Each kernel was assigned to predict stock prices with features of financial news of the target firm and its relevant firms. The results of this study are as follows. The results of this paper are as follows. (1) Following the existing research flow, we confirmed that it is an effective way to forecast stock prices using news from relevant companies. (2) When looking for a relevant company, looking for it in the wrong way can lower AI prediction performance. (3) The proposed approach with random matrix theory shows better performance than previous studies if cluster analysis is performed based on the true correlation by removing market-wide effects and random signals. The contribution of this study is as follows. First, this study shows that random matrix theory, which is used mainly in economic physics, can be combined with artificial intelligence to produce good methodologies. This suggests that it is important not only to develop AI algorithms but also to adopt physics theory. This extends the existing research that presented the methodology by integrating artificial intelligence with complex system theory through transfer entropy. Second, this study stressed that finding the right companies in the stock market is an important issue. This suggests that it is not only important to study artificial intelligence algorithms, but how to theoretically adjust the input values. Third, we confirmed that firms classified as Global Industrial Classification Standard (GICS) might have low relevance and suggested it is necessary to theoretically define the relevance rather than simply finding it in the GICS.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.4 no.4
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• pp.113-125
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• 1984

Water supply has been mainly dependent on the construction of the dams in Korea. It is difficult, however, to continue to construct dams for many reasons, such as the decrease of construction sites, the increase of construction costs, the compensation of residents in flooded areas, and the environmental effects. Water demands have increased and are expected to continue increasing due to the concentration of people in the cities, the rise of the living standard, and rapid industrial growth. It is acutely important to find countermeasures such as development of ground water, desalination, and recycling of waste water to cope with increasing water demands. Recycling waste water includes all means of supplying non-potable water for their respective usages with proper water quality which is not the same quality as potable water. The usages of the recycled water include toilet flushing, air conditioning, car washing, yard watering, road cleaning, park sprinkling, and fire fighting, etc. Raw water for recycling is obtained from drainage water from buildings, toilets, and cooling towers, treated waste water, polluted rivers, ground water, reinfall, etc. The water quantity must be considered as well as its quality in selecting raw water for the recycling. The types of recycling may be classified roughly into closed recycle systems and open recycle systems, which can be further subdivided into individual recycle systems, regional recycle systems and large scale recycle system. The treatment methods of wastewater combine biochemical and physiochemical methods. The former includes activated sludge treatment, bio-disc treatment, and contact aeration treatment, and the latter contains sedimentation, sand filtration, activated carbon adsorption, ozone treatment, chlorination, and membrane filter. The recycling patterns in other countries were investigated and the effects of the recycling were divided into direct and indirect effects. The problems of water reuse in recycle patterns were also studied. The problems include technological, sanitary, and operational problems as well as cost and legislative ones. The duties of installation and administrative organization, structural standards for reuse of water, maintenance and financial disposal were also studied.

• Applied Chemistry for Engineering
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• v.29 no.3
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• pp.342-349
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• 2018

In this study, the physicochemical properties, emulsifying capacity, moisture content and cytotoxicity of the composite material produced by transesterification reactions of the olive oil (olive oil esters) were investigated for cosmetic applications. Olive oil esters with short (S) and long (L) reaction times were studied. From the TLC-image analysis, composition ratios of the olive oil esters S were found to be 5.2, 24.1, 46.4, and 21.9% for mono-, di-, tri-glyceride, and fatty acid ethyl ester, respectively. Those of the olive oil esters L were 4.1, 24.7, 40.6, and 28.8% for mono-, di-, tri-glyceride, and fatty acid ethyl ester, respectively. The iodine value, acid value, saponification value, unsaponified matter, refractive index, and specific gravity were determined and purity tests were also carried out and normalized to establish standards and testing methods for using olive oil esters in cosmetics. To evaluate their emulsifying capacities, the O/W emulsion was prepared without surfactants and the formation of the emulsified particles were confirmed. After 5 days of applying the olive oil esters to human skin, the skin moisture retention was improved by 13.1% from the initial state. For the evaluation of toxicity on human skin cells, the olive oil esters showed 90% or more of the cell viability at $0.2-200{\mu}g/mL$. These results suggested that olive oil esters can be applied as natural/non-toxic ingredients to cosmetics industries.

• Journal of Digital Convergence
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• v.9 no.6
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• pp.137-151
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• 2011

This dissertation aims to empirically analyze the effect of cultivation of software industry on the local economy through Inter-regional Software Input-Output Analysis. The temporal range of analysis of effect of software industry on the local economy shall be for the year 2005 since analysis is made on the basis of the Regional Industrial Input-Output Table published by the Bank of Korea in 2005, and spatial domain shall be limited to the 16 metropolitan cities and provinces, which are the standards for each administrative zone. Results of analysis of this dissertation are as follows. Firstly, average inverse matrix coefficient of software industry for each region was computed to be 1.6248, which is lower than the average inverse matrix coefficient of 1.7979 for the entire industries. Secondly, among these, inverse matrix coefficient of software industry for each region on other industry within the same region was 0.1794, which is higher than that of entire industries at 0.1382. However, average inverse matrix coefficients of software industry for each region on self-industry within the same region and entire industries in other regions were found to be 1.0119 and 0.4335, respectively, which is lower than those of entire industries at 1.0982 and 0.5616, respectively. Thirdly, domestic produces induced by final demand items of software industry for each region was the highest for Seoul with 17.3309 trillion Korean won, accounting for 81.0% of the total, followed by Gyeonggi with 2.3370 trillion Korean won, 10.9% of the total. Fourthly, distribution ratios of domestic produces induced by final demand items of software industry for each region were found to be 19.1%, 72.1% and 8.8% with respect to the weight of consumption, investment and export, respectively, thereby illustrating very high level of distribution ratios of domestic produces being induced by investment in comparison to the distribution ratios of domestic produces being induced for the entire industries at 47.3%, 19.8% and 32.9%, respectively.

• Management & Information Systems Review
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• v.36 no.3
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• pp.151-165
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• 2017

This study investigates the effect of revenue recognition by percentage of completion method on financial analysts' earnings forecasting information in order industry. Specifically, we examines how the analysts' earnings forecast errors and biases differ according to whether or not to report the unbilled revenue account balance and the level of unbilled revenue account balance. The sample consists of 453 firm-years listed in Korea Stock Exchange during the period from 2010 to 2014 since the information on unbilled revenue accounts can be obtained after the adoption of K-IFRS. The results are as follows. First, we find that the firms with unbilled revenue account balances have lower analysts' earnings forecast accuracy than the firms who do not report unbilled revue account balances. In addition, we find that the accuracy of analysts' earnings forecasts decreases as the amount of unbilled revenue increases. Unbilled revenue account balances occur when the revenue recognition of the contractor is faster than the client. There is a possibility that managerial discretionary judgment and estimation may intervene when the contractor calculates the progress rate. The difference between the actual progress of the construction and the progress recognized by the company lowers the predictive value of financial statements. Our results suggest that the analysts' earnings forecasts may be more difficult for the firms that report unbilled revenue balances as applying the revenue recognition method based on the progress criteria. Second, we find that the firms reporting unbilled revenue account balances tend to have higher the optimistic biases in analysts' earnings forecast than the firms who do not report unbilled revenue account balances. And we find that the analysts' earnings forecast biases are increases as the amount of unbilled revenue increases. This study suggests an effort to reduce the arbitrary adjustment and estimation in the measurement of the progress as well as the introduction of the progress measurement method which can reflect the actual progress. Investors are encouraged to invest and analyze the characteristics of the order-based industry accounting standards. In addition, the results of this study empower the accounting transparency enhancement plan for order industry proposed by the policy authorities.

• Asia-Pacific Journal of Business Venturing and Entrepreneurship
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• v.14 no.2
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• pp.221-233
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• 2019

In Korea, small and medium sized domestic enterprises(SMEs) play an pivotal role in the national economy, accounting for 99.9% of all enterprises, 87.9% of total employment, and 48.3% of production. and SMEs was driving a real force of the development of national economy in many respects such as innovation, job creation, industrial diversity, balanced regional development. Despite their crucial role in the national development, most of SMEs suffer from a lack of R&D capabilities and equipments as well as funding capacity. Public R&D institutes can provide SMEs with valuable supplementary technological knowledge and help them build technological capacity. so, In order to effectively support SMEs, government and public R&D institutes must be a priority to know about the factors influencing the performance related to technology transfer and technological collaborations. In particular, SMEs are not only taking up a large portion of the national economy, but also their influence in politics and economy so strong that raising the competitiveness of small and medium-sized companies is a national policy goal that must be achieved in order to achieve sustained economic growth. For this reason, it is necessary to look specifically at the relationship between concepts such as the environment, strategy, and organizational culture surrounding the enterprise to enhance the competitiveness of SMEs. The paper analyzes 665 companies to find out which organizational culture affects their performance by classification and type of business of SMEs. This study demonstrated that when SMEs seek consistency in their external environment, strategies, and organizational structure to maintain their continued competitiveness. According to three-way analysis of variance (3-way ANOVA) indicates that classification of industries in SMEs has statistically significant main effects, but the type of business and organizational culture do not have significant effects. However, the company's organizational performance (operating profit) of SMES were found to differ significantly in comparison between groups according to classification standards of industries, and therefore adopted some parts. In addition, an analysis of the effect of interaction between the three independent variables of small and medium-sized enterprises has shown that there are statistically significant interaction effects among classification, types of business, and organizational cultures. The results shows that there is an organizational culture suitable for each industry classification and type of business of an entity, and is expected to be used as a basis for establishing promotion policies related to the incubation and commerciality of small and medium-sized venture companies in the future.

• Journal of Bio-Environment Control
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• v.31 no.4
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• pp.485-496
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• 2022

Modern agriculture is being transformed into smart agriculture to maximize production efficiency along with changes in the 4th industrial revolution. However, rural areas in Korea are facing challenges of aging, low fertility, and population outflow, making it difficult to transition to smart agriculture. Among ICT technologies, simulation allows users to observe or experience the results of their choices through imitation or reproduction of reality. The combination of the three-dimension (3D) model and the greenhouse simulator enable a 3D experience by virtual greenhouse for fruits and vegetable cultivation. At the same time, it is possible to visualize the greenhouse under various cultivation or climate conditions. The objective of this study is to apply the greenhouse climate management model for simulation development that can visually see the state of the greenhouse environment under various micrometeorological properties. The numerical solution with the mathematical model provided a dynamic change in the greenhouse environment for a particular greenhouse design. Light intensity, crop transpiration, heating load, ventilation rate, the optimal amount of CO₂ enrichment, and daily light integral were calculated with the simulation. The results of this study are being built so that users can be linked through a web page, and software will be designed to reflect the characteristics of cladding materials and greenhouses, cultivation types, and the condition of environmental control facilities for customized environmental control. In addition, environmental information obtained from external meteorological data, as well as recommended standards and set points for each growth stage based on experiments and research, will be provided as optimal environmental factors. This simulation can help growers, students, and researchers to understand the ICT technologies and the changes in the greenhouse microclimate according to the growing conditions.

• Korea Science and Art Forum
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• v.20
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• pp.147-158
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• 2015

This study made an approach to the industrial exhibition space, which is a medium of marketing communication, from the position of an enterprise and consumers through the output of Space Design, and conducted it with focus on B2B transactions among specialized exhibitions. In addition, this study inquired into what factors should be considered along with space design by interpreting the purpose of participating in the exhibition and space design of the enterprise which supply capital goods, elements, related technologies and materials, etc. This study aimed at drawing the direct/indirect effect, produced by space design, on the marketing by analyzing correlation between space design and participating enterprises' marketing. Despite the marketing effect of the exhibition, which was proved by preceding research results, the reality is that exhibition-participating expenses work as considerable burden on enterprises. Particularly, booth design, which is forming the most proportion among the participating expenses, was found to have insufficient influence on visitors due to the decline in its importance among diverse factors influencing visitor's decision to visit a booth. Regardless of the business category of participating enterprises in the exhibition, the standard of exhibits was ranked as the most important consideration factor in visiting a booth. Even by business category, the standard of booth design rarely had an influence on booth visit. Booth design had an affirmative influence on participating enterprise's preference, but its influence on product purchase or business talk & contact with a participating enterprise or price was found to be extremely low. It's difficult to judge marketing success or failure of an exhibition by the form and standard of booth design. Preferably, this study infers that it's necessary to put much weight on qualitative excellence of an exhibition, which consists of participation of an enterprise in possession of excellent technologies, exhibits with higher standards and high-quality visitors with purchasing power. This study suggests that it's more effective to set up the plan for expansion of participation in exhibition by optimally regulating the proportion of space design in participating expense to increase marketing effectiveness of an exhibition. The limitations of this study, analysis of which based on the visitors to an exhibition only, requires supplementation through the follow-up research work on participating enterprises in the exhibition.

• The Korean Journal of Air & Space Law and Policy
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• v.35 no.2
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• pp.137-168
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• 2020

Air passengers may be compensated for damages based on the above agreement when the passenger suffers an accident to the extent that they are recognized as an accident under Article 17 of the Montreal Convention in 1999. If a flight or cabin crew and passengers both undergo an accident, passengers are subjected to compensation under the Montreal Convention however flight cabin crews will be compensated by the Labor Law, which is the governing law in the labor contract with the airline. The flight or cabin crew boarding the aircraft work is on a work contract, not a passenger transport contract. Therefore, if the flight or cabin crew on the aircraft is injured due to an accident, and the air carrier is liable for default due to a labor contract, the Labor Law, workers or survivors claim damages due to illegal acts against the employer. In which case, civil law will apply. In this regard, if a Chinese cabin crew working for a Chinese airline dies due to an accident in the Republic of Korea, whether the family of the deceased claims damages against the Chinese airline or not has international court jurisdiction in the Republic of Korea, which is the place of tort. We examined whether it is the law of the Republic of Korea or whether it's the Chinese law, the law applicable to the work contract, is applied. Also, Seoul District Court 1995.5.18. The sentence 94A 14144 was found that if the injured crew during the flight work was not satisfied with the insurance compensation under the Labor Standards Act and the Industrial Accident Compensation Insurance Act, he could claime to damage under the civil law against an air carrier or third parties responsible for the accident. This law case shows that you can claim a civil damage as a cause. In case of death due to an existing illness while on the way to work, the Korea Workers'Compensation and Welfare Service did not recognize the death of the deceased as an occupational accident, and the trial was canceled by the parents of the deceased for the survivor's benefit and funeral expenses. (Seoul Administrative Court 2017.8. 31. Although the sentence was judged as an occupational disaster in 2016, the 2016 8816 Decision), it was defeated in the appeals court (Seoul High Court 2018.7.19.Sentence 2017 No. 74186) and I criticized the judgment of the appeal by analyzing the deceased's disease and related the cause of it to workload. Sometimes, a flight or cabin crew is on board not for the flight duty such as transferring to another flight or returning to the home base or lay-over place after their scheduled flight, this is called "Deadheading". If the crew who is not considered the same as a passenger, but is not on duty, is injured in an accident, does the crew claim compensation for damages under the labor contract or whether the Montreal Convention is applied to the passenger. In conjunction with the discussion, there was a similar case, In re Mexico City Aircrash of October 31, 1979, 708 F.2d 400 (9th Cir. 1983), Demanes v. United Airlines, 348 F.Supp. 13 (C.D.Cal. 1972), Sulewski v. Federal Express Corp., 749 F.Supp. 506 (S.D.N.Y. 1990) and reviewed by the European Court of Justice (CJEU) at Wucher Helicopter GmbH and Euro-Aviation Versicherungs AG v. After examining several acts in several countries it's undeniably crucial to clearly understand the definition of "passenger" as stated in the Fridolin Santer case.

• Korean Security Journal
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• no.18
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• pp.169-190
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• 2009

Today, the rapid advance of scientific technologies has brought about fundamental changes to the types and levels of terrorism while the war against the world more than one thousand small and big terrorists and crime organizations has already begun. A method highly likely to be employed by terrorist groups that are using 21st Century state of the art technology is cyber terrorism. In many instances, things that you could only imagine in reality could be made possible in the cyber space. An easy example would be to randomly alter a letter in the blood type of a terrorism subject in the health care data system, which could inflict harm to subjects and impact the overturning of the opponent's system or regime. The CIH Virus Crisis which occurred on April 26, 1999 had significant implications in various aspects. A virus program made of just a few lines by Taiwanese college students without any specific objective ended up spreading widely throughout the Internet, causing damage to 30,000 PCs in Korea and over 2 billion won in monetary damages in repairs and data recovery. Despite of such risks of cyber terrorism, a great number of Korean sites are employing loose security measures. In fact, there are many cases where a company with millions of subscribers has very slackened security systems. A nationwide preparation for cyber terrorism is called for. In this context, this research will analyze the current status of Korea's cyber security systems and its laws from a policy perspective, and move on to propose improvement strategies. This research suggests the following solutions. First, the National Cyber Security Management Act should be passed to have its effectiveness as the national cyber security management regulation. With the Act's establishment, a more efficient and proactive response to cyber security management will be made possible within a nationwide cyber security framework, and define its relationship with other related laws. The newly passed National Cyber Security Management Act will eliminate inefficiencies that are caused by functional redundancies dispersed across individual sectors in current legislation. Second, to ensure efficient nationwide cyber security management, national cyber security standards and models should be proposed; while at the same time a national cyber security management organizational structure should be established to implement national cyber security policies at each government-agencies and social-components. The National Cyber Security Center must serve as the comprehensive collection, analysis and processing point for national cyber crisis related information, oversee each government agency, and build collaborative relations with the private sector. Also, national and comprehensive response system in which both the private and public sectors participate should be set up, for advance detection and prevention of cyber crisis risks and for a consolidated and timely response using national resources in times of crisis.