• Journal of Intelligence and Information Systems
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• v.26 no.3
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• pp.37-50
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• 2020

Information security has become an important issue in the world. Various information and communication technologies, such as the Internet of Things, big data, cloud, and artificial intelligence, are developing, and the need for information security is increasing. Although the necessity of information security is expanding according to the development of information and communication technology, interest in information security investment is insufficient. In general, measuring the effect of information security investment is difficult, so appropriate investment is not being practice, and organizations are decreasing their information security investment. In addition, since the types and specification of information security measures are diverse, it is difficult to compare and evaluate the information security countermeasures objectively, and there is a lack of decision-making methods about information security investment. To develop the organization, policies and decisions related to information security are essential, and measuring the effect of information security investment is necessary. Therefore, this study proposes a method of constructing an investment portfolio for information security measures using game theory and derives an optimal defence probability. Using the two-person game model, the information security manager and the attacker are assumed to be the game players, and the information security countermeasures and information security threats are assumed as the strategy of the players, respectively. A zero-sum game that the sum of the players' payoffs is zero is assumed, and we derive a solution of a mixed strategy game in which a strategy is selected according to probability distribution among strategies. In the real world, there are various types of information security threats exist, so multiple information security measures should be considered to maintain the appropriate information security level of information systems. We assume that the defence ratio of the information security countermeasures is known, and we derive the optimal solution of the mixed strategy game using linear programming. The contributions of this study are as follows. First, we conduct analysis using real performance data of information security measures. Information security managers of organizations can use the methodology suggested in this study to make practical decisions when establishing investment portfolio for information security countermeasures. Second, the investment weight of information security countermeasures is derived. Since we derive the weight of each information security measure, not just whether or not information security measures have been invested, it is easy to construct an information security investment portfolio in a situation where investment decisions need to be made in consideration of a number of information security countermeasures. Finally, it is possible to find the optimal defence probability after constructing an investment portfolio of information security countermeasures. The information security managers of organizations can measure the specific investment effect by drawing out information security countermeasures that fit the organization's information security investment budget. Also, numerical examples are presented and computational results are analyzed. Based on the performance of various information security countermeasures: Firewall, IPS, and Antivirus, data related to information security measures are collected to construct a portfolio of information security countermeasures. The defence ratio of the information security countermeasures is created using a uniform distribution, and a coverage of performance is derived based on the report of each information security countermeasure. According to numerical examples that considered Firewall, IPS, and Antivirus as information security countermeasures, the investment weights of Firewall, IPS, and Antivirus are optimized to 60.74%, 39.26%, and 0%, respectively. The result shows that the defence probability of the organization is maximized to 83.87%. When the methodology and examples of this study are used in practice, information security managers can consider various types of information security measures, and the appropriate investment level of each measure can be reflected in the organization's budget.

• Journal of the Korean Institute of Traditional Landscape Architecture
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• v.34 no.3
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• pp.50-66
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• 2016

This study attempts to understand and explain how "Directed Attention Restorative Environment (DARE)" is managed and fostered in "Gang-Hak (講學)" and "Yu-Sik (遊息)" spaces both inside and outside of Oksan Seowon Confucian Academy, Gyeongju. Directed Attention is a pivotal element in human information processing so that its restoration is crucial for effective thinking and learning. According to Kaplan & Kaplan's Attention Restoration Theory, an environment, in order to be restorative, should have four elements: 'Being Away,' 'Extent,' 'Fascination,' and 'Compatibility.' We could confirm OkSan Seowon Confucian Academy has an inner logic that integrates two basically different spacial concepts of "Jangsu" and "Yusik" and thus fosters the Attention Restorative Environment. Particularly, the Four Mountains and Five Platforms (四山五臺) surrounding the premises provides an excellent learning environment, and is in itself educational in terms of the Neo-Confucian epistemology with "Attaining Knowledge by way of Positioning Things (格物致知)" as its principle precept, and of its aesthetics with "Connectedness with Nature" as its central tenet. This study attempts to recapture the value of Korea's cultural heritage concerning the Human/Nature relationship; and it may provide useful insights and practical guidelines/grounds in designing today's schools and campuses, where the young people's needs for the Directed Attention- and Attention Restorative- Servicescapes seem to be greater than ever.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.8 no.6
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• pp.1634-1647
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• 2007

"To invest or not to invest?" Most business leaders are frequently faced with this question on new and ongoing projects. The challenge lies in deciding what projects to choose, expand, contract, defer, or abandon. The project valuation tools used in this process are vital to making the right decisions. Traditional tools such as discounted cash flow (DCF)/net present value (NPV) assume a "fixed" path ahead, but real world projects face uncertainties, forcing us to change the path often. Comparing to other traditional valuation methods, the real options approach captures the flexibility inherent to investment decisions. The use of real options has gained wide acceptance among practitioners in a number of several industries during the last few decades. Even though the options are present in all types of business decisions, it is still not considered as a proper method of valuation in some industries. Mining has been comparably slow to adopt new valuation techniques over the years. The reason fur this is not entirely clear. One possible reason is the level and types of risks in mining. Not only are these risks high, but they are also more numerous and involve natural risks compared with other industries. That is why the purpose of this study is to deal with a more practical approach to project valuation, known as real options analysis in mining industry. This paper provides a case study approach to the copper mining industry using a real options analysis. It shows how companies can minimize investment risks, exercise flexibility in decision making and maximize returns.

• Journal of Nuclear Fuel Cycle and Waste Technology(JNFCWT)
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• v.16 no.2
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• pp.183-193
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• 2018

Currently, the Korea Atomic Energy Research Institute (KAERI) is planning to build the Ki-Jang Research Reactor (KJRR) in Ki-Jang, Busan. It is important to safely dispose of low-level radioactive waste from the operation of the reactor. The most efficient way to treat radioactive waste is cement solidification. For a radioactive waste disposal facility, cement solidification is performed based on specific waste acceptance criteria such as compressive strength, free-standing water, immersion and leaching tests. Above all, the leaching test is important to final disposal. The leakage of radioactive waste such as $^{137}Cs$ causes not only regional problems but also serious global ones. The cement solidification method is simple, and cheaper than other solidification methods, but has a lower leaching resistance. Thus, this study was focused on the development of cement solidification for an enhancement of cesium leaching resistance. We used Zeolite and Loess to improve the cesium leaching resistance of KJRR cement solidification containing simulated KJRR liquid waste. Based on an SEM-EDS spectrum analysis, we confirmed that Zeolite and Loess successfully isolated KJRR cement solidification. A leaching test was carried out according to the ANS 16.1 test method. The ANS 16.1 test is performed to analyze cesium ion concentration in leachate of KJRR cement for 90 days. Thus, a leaching test was carried out using simulated KJRR liquid waste containing $3000mg{\cdot}L^{-1}$ of cesium for 90 days. KJRR cement solidification with Zeolite and Loess led to cesium leaching resistance values that were 27.90% and 21.08% higher than the control values. In addition, in several tests such as free-standing water, compressive strength, immersion, and leaching tests, all KJRR cement solidification met the waste acceptance or satisfied the waste acceptance criteria for final disposal.

• Applied Biological Chemistry
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• v.43 no.3
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• pp.218-224
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• 2000

The efforts were made to optimite ethanol extraction from persimmon leaf with the time of extraction$(1.5{\sim}2.5\;hrs)$, the temperature of extraction$(70{\sim}90^{\circ}C)$, and the concentration of ethanol$(0{\sim}40%)$ as three primary variables together with several functional characteristics of persimmon leaf as reaction variables. The conditions of extraction was best fitted by using response surface methodology through the center synthesis plan, and the optimal conditions of extraction were established. The contents of soluble solid and soluble tannin went up as the concentration of ethanol went up and the temperature of extraction went down, and the turbidity went down as the concentration of ethanol went down. Electron donation ability was hardly affected by the extraction temperature and had the tendency to go up as the concentration of ethanol went up. The inhibitory activity of xanthine oxidase(XOase) had the tendency to go up as both the concentration of ethanol and the temperature of extraction went up. The inhibitory activity of angiotensin converting enzyme(ACE), the significance of which still was not recognized, showed the maximum when the concentration of ethanol was 27%. In result, the optimal conditions of extraction was the extraction time of two hours, the extraction temperature of $75{\sim}81^{\circ}C$, and the ethanol concentration of $33{\sim}35%$.

• 대한공업교육학회지
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• v.45 no.1
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• pp.63-83
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• 2020

The purpose of this study is to provide the basic materials needed to plan the NCS Learning Module to be used effectively in practical courses. In this study, teachers and students' satisfaction surveys were collected about the NCS (National Competency Standards) learning module, career and field practice, practical environment used in the construction subject course. This study was conducted on public high schools in Chungcheong province (including Daejeon), which is operating practice course using the NCS learning module. The research questions are as follows; First, how was the satisfaction of teachers and students in the practical subject class using NCS learning module? Second, what is the degree of satisfaction of teacher's career and field practice guidance, student's career decision and field practice after the practical course using NCS learning module? Third, the satisfaction level of the developed NCS learning module and practical subject class using the same was determined by setting whether the number of training of NCS-related teachers or the presence or absence of on-the-job training of students were affected? The results of the study are as follows; As a result of comparing the teachers' and students' satisfaction, the students showed satisfaction in all items, whereas the teachers showed 'content level', 'interest', 'necessary knowledge', 'skill acquisition', 'Improvement of practical skills (level of skill performance)', 'scale of experimental practice', and 'items of experimental practice equipment' were dissatisfied. It was found that the number of NCS related teachers' training (or absence) or the presence of students on the field had an effect on the satisfaction of the developed NCS learning module and the practical course using it. In order to fully utilize the developed NCS learning module in the practical course, it is required to develop and construct the teaching material of the teacher who can serve as an intermediary for conceptualization and understanding of job skills. It is necessary to increase the number of education and training specialists to positively reflect the demands of the education field.

• Journal of the Korean Institute of Landscape Architecture
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• v.46 no.4
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• pp.61-75
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• 2018

This study aims to verify the effect of green buffers, built as urban planning facilities on the reduction of ultra-fine particulate($PM_{2.5}$) and analyze changes in ultra-fine particles by structure, green volume and planting types of wayside green buffers, thus drawing the factors that can be used when green buffers are built to reduce ultra-fine particulate based on the results. This study selected Songpa-gu, and investigated 16 sites on 5 green buffers adjacent to two of Songpa-gu's main roads, 'Yangjaedaero' and 'Songpadaero'. This study divided all the green spaces into three different types-slope type, plain type and mounding type, and analyzed the mean green volume. As a result of measuring the concentration of $PM_{2.5}$, this study found that it was $55.5{\mu}g/m^3$ on average in winter, which was a harmful level according to the integrated environmental index provided by Seoul City, saying that levels above $50{\mu}g/m^3$ may have a harmful effect on sensitive groups of people. Particularly, the concentration of $PM_{2.5}$ was $38.6{\mu}g/m^3$ on average in spring, which exceeded the mean concentration of $PM_{2.5}$ in Seoul City in 2015. The mean concentrations of $PM_{2.5}$ in every investigation spot were $46.6{\mu}g/m^3$ for sidewalks, $45.5{\mu}g/m^3$ for green spaces and $42.9{\mu}g/m^3$ for residential areas, all of which were lower than $53.2{\mu}g/m^3$ for roads, regardless of the season. The concentration of $PM_{2.5}$ for residential areas was the lowest. In the stage of confirming the effect of green buffers, this study analyzed the correlation between the green volume of vegetation and the fluctuated rate of ultra-fine particles. As a result, it was found that the green coverage rate of trees and shrubs was related to the crown volume in every investigation spot but were mutually and complexly affected by each other. Therefore, this study judged that the greater the number of layers of shrubs that are made, the more effective it is in reducing the concentration of $PM_{2.5}$. As for seasonal characteristics, this study analyzed the correlation between the concentration of $PM_{2.5}$ for residential areas in winter and the green coverage rate of each green space type. As a result, this study found that there was a negative correlation showing that the higher the shrub green coverage rate is, the lower the concentration value becomes in all the slope-type, plain-type and mounding-type green spaces. This study confirmed that the number of tree rows and the number of shrub layers have negative correlations with the fluctuated concentration rate of $PM_{2.5}$. Especially, it was judged that the shrub green volume has greater effect than any other factor, and each green space type shows a negative correlation with the shrub coverage rate in winter.

• Journal of radiological science and technology
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• v.35 no.2
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• pp.157-164
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• 2012

The purpose of this study is to analyze the dose distribution when wedge filter is used in the various tissue electron density materials. The dose distribution was assessed that the enhanced dynamic wedge filter and physical wedge filter were used in the solid water phantom, cork phantom, and air cavity. The film dosimetry was suitable simple to measure 2D dose distribution. Therefore, the radiochromic films (Gafchromic EBT2, ISP, NJ, USA) were selected to measure and to analyze the dose distributions. A linear accelerator using 6 MV photon were irradiated to field size of $10{\times}10cm^2$ with 400 MUs. The dose distributions of EBT2 films were analyzed the in-field area and penumbra regions by using dose analysis program. In the dose distributions of wedge field, the dose from a physical wedge was higher than that from a dynamic wedge at the same electron density materials. A dose distributions of wedge type in the solid water phantom and the cork phantom were in agreements with 2%. However, the dose distribution in air cavity showed the large difference with those in the solid water phantom or cork phantom dose distributions. Dose distribution of wedge field in air cavity was not shown the wedge effect. The penumbra width, out of the field of thick and thin, was observed larger from 1 cm to 2 cm at the thick end. The penumbra of physical wedge filter was much larger average 6% than the dynamic wedge filter. If the physical wedge filter is used, the dose was increased to effect the scatter that interacted with photon and physical wedge. In the case of difference in electron like the soft tissue, lung, and air, the transmission, absorption, and scattering were changed in the medium at high energy photon. Therefore, the treatment at the difference electron density should be inhomogeneity correction in treatment planning system.

• Korean Security Journal
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• no.28
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• pp.33-56
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• 2011

This study is to practice a analysis of Q-methodological preference degree about the subjects on school curriculum centering around the views of the policemen in active service who are with Gwang Ju and Jeon Nam region. Concretely, this study mixed the subjects on school curriculum related to the police administration of universities located in Gwang Ju and Jeon Nam region and abstracted the twenty seven items as the final question point. Above this, this study integrated the similar or repeated subjects and drew up the question items through seperation process among the different subjects. After this, this study selected the twenty policemen as a first P-sample in active service presently on fourth month in the year 2011. In this process, this study eliminated the materials of six policemen who replyed unhonestly and selected the materials of ten-four policemen as a final effective sample. Furthermore, this study applicated a principal component analysis. This study practiced the I.II.III types of a preference degree analysis of the subjects related to the police administration. the concrete results are as follows: In a I type, the positive consent was showed in the subjects of criminal law, criminal procedure law, criminal speciality law and so on. In a II type, the positive consent was showed in criminal investigation science, emergency measure, the art of self-defence, criminal law, criminal procedure law and so on. In a III type, the positive consent was showed in criminal science, criminal investigation science, criminal procedure law, introduction to police science, police ethics and so on. On this basis, this study concluded the following common opinions. Firstly the actual and evidencial subjects which the policemen in active service feel as the commons were criminal investigation, criminal science, police ethics, criminal speciality law, criminal law business, police administration science, police law practice, emergency measure, the art of self-defence, general rules of civil law, administrative law and so on.

• Journal of the Korean Institute of Traditional Landscape Architecture
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• v.34 no.4
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• pp.37-50
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• 2016

Recognizing the problem of fallacy in geographical name of Changokbyeong(蒼玉屛), assumption has been made on the location of Changokbyeong through literature research on antique maps, ancient paintings, and old prose, through field survey on rock inscriptions and landscape characteristics, and through interviews with local people. Furthermore, Baegyeonwa, the Cuckoo Hut, and Iyangjung(二養亭), an annex to the cottage, both of which were managed by Saahm Park Soon(思菴 朴淳), the Subject of Jouissance, were studied in depth with emphasis on the spatial structure as well as special features of the area as a garden. The major findings are as follows: Changokbyeong is a spatial threshold that imparts a sense of unity with Okbyeng seowon(玉屛書院) and indeed Changokbyeong is presumed to have been the frontal river terrace of Okbyeng seowon according to the analysis of antique maps and rock inscriptions. This ancient location and the Ogari Stone Wall, the present day Changokbyeong, are only 460m away so that both areas are considered as falling under the influence of Changokbyeong landscape. The expression "Changokbyeong Geupsangeum(蒼玉屛及散襟)" written in an old prose tells us that the high rock wall with Sangeumdae inscribed on the rock might be the rock wall of Changokbyeong. In addition, while not a single rock inscription has been found on the Ogari Stone Wall, 11 rock inscriptions designed and ordered by Saahm Park Soon, the Subject of Jouissance, are found on every corner of the high rock wall standing in front of Okbyeng seowon, 8 of those 11 being place names and recitative poems(known as Jeyeongsi: 題詠詩) in close formation resembling the handwritings in a little notebook. This provides a strong evidence for assuming the location of Changokbyeong to be the frontal river terrace of Okbyeng seowon. The "Songgyun Jeoljo Suwol Jeongshin(松筠節調 水月精神)" rock inscription on Changokbyeong should be considered as the stamping ground and as the symbolic language of Changokbyeong that bears the high character and nobility of the Subject of Jouissance, Saahm Park Soon. The inscription should also be recognized as the handwritings of Wooahm Song Si-Yeol(尤庵 宋時烈) correcting the misconceptions that persisted until today. Meanwhile, the garden remains of Saahm's Changokbyeong are composed of four sites: Sangeumdae-Sugyeongdae-Cheonghakdae-Baekhakdae from the left. At the back of Sangeumdae, there is the original house, the Baegyeonwa(拜鵑窩), and on the fantastically shaped stone wall at the left of Baekhakdae, there is the annex, the Iyangjung, together creating a landscape composition that overlooks the splendor of the Ogari Stone Wall. The Iyangjung is located on the highest spot to the left of the four sites, and it is believed to have been a little outhouse and library for Saahm which remains to the present day as a place where Saahm's character can be felt. The drinking plates[窪樽] made of rock that are affectionately arranged on the broad flat rock in front of Iyangjung is part of the garden remains that reflects the artistic taste of Saahm regarding the drinking culture at the time.