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Studies on the Properties of Populus Grown in Korea (포플러재(材)의 재질(材質)에 관(關)한 시험(試驗))

  • Jo, Jae-Myeong;Kang, Sun-Goo;Lee, Yong-Dae;Jung, Hee-Suk;Ahn, Jung-Mo;Shim, Chong-Supp
    • Journal of the Korean Wood Science and Technology
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    • v.10 no.3
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    • pp.68-87
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    • 1982
  • In Korea, this is the situation at moment that the total demand of timber in 1972 is more than 5 million cubic meters. On the other hand, however, the available domestic supply of timber at the same year is only about, 1 million cubic meters. A great unbalancing between demand and supply of timber has been prevailing. To solve this hard problem, it has been necessitiated to build up the forest stocks as early as possible with fast grown species such as poplar. Under circumstances, poplar plantations which have been carryed on government and private have reached to large area of 116,603 hectors from 1962 up to date. It has now be come a principal timber resources in this country, and required the basic study on various properties of wood for it's proper utilization, since it has not been made of any systematic study on the properties of Populus grown in Korea. In order to investigate the properties such as anatomical, physical and mechanical properties of nine different species (P. euramericana Guiner I-214. P. euramericana Guiner I-476, P. deltoides Marsh, P. nigra var. italica (Muchk) Koeme, P. alba L.,P. alba $\times$ glandulosa P. maximowiczii Henry, P. koreana Rehder, P. davidiana Dode) of poplar for their proper use and development of new ways of grading processing and quality improving, this study has been made by the Forest Research Institute.

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Mineralogy and Mineral-chemistry of REE Minerals Occurring at Mountain Eorae, Chungju (충주 어래산 일대에서 산출하는 희토류 광물의 광물학적 및 광물화학적 특성)

  • You, Byoung-Woon;Lee, Gill Jae;Koh, Sang Mo
    • Economic and Environmental Geology
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    • v.45 no.6
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    • pp.643-659
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    • 2012
  • The Chungju Fe-REE deposit is located in the Kyemyeongsan Formation of the Ogcheon Group. The Kyemyeongsan Formation includes meta-volcanic rocks and pegmatite hosted REE deposit which show different kind of REE-containing minerals. The meta-volcanic rocks hosted REE deposits' main REE minerals are allanite, zircon, apatite, and sphene, whereas the pegmatite hosted REE deposits is mainly composed of fergusonite, and karnasurtite, zircon, thorite. The meta-volcanic rock hosted major REE mineral is allanite as the form of aggregation and contains 23.89-29.19 wt% TREO (Total Rare Earth Oxide), 4.71-9.92 wt% $La_2O_3$, 11.30-14.33 wt% $Ce_2O_3$, 0.11-0.29 wt% $Y_2O_3$, 0.15-0.94 wt% $ThO_2$, as a formula of (Ca, Y, REE, Th)$_{2.095}$(Mg, Al, Ti, Mn, $Fe^{3+})_{2.770}(SiO_4)_{2.975}(OH)$. Accompanying REE in a coupled substitution for $Ca^{2+}$ (M1 site) and $Al^{3+}-Fe^{2+}$ (M2 site) leads to a large chemical variety. Due to the allanite's high contents of Fe, it belongs to Ferrialanite. The pegmatite hosted deposit's domi-nant REE mineral is fergusonite as prismatic or subhedral grains associated with zircon, fluorite and karnasurtite. Geochemical composition of the fergusonite($YNbO_4$) suggests substitution of Y-REE and Y-Th in A-site, and Nb-Ta-Ti in B-site, furthermore the proportion of $Y_2O_3$ and $Nb_2O_5$ is oddly 1:1.5 comparing to the ideal ratio 1:1 and Nb is higher than Y, also A-site Y actively substitutes with REE. Karnasurtite in pegmatite variously ranges 9.16-22.88 wt% $Ce_2O_3$, 2.15-9.16 wt% and $La_2O_3$, 0.44-10.8 wt% $ThO_2$, as a calculated formula (Y, REE, Th, K, Na, Ca)$_{1.478}(Ti, Nb)_{1.304}$(Mg, Al, Mn, $Fe^{3+})_{0.988}$(Si, P)$_{1.431}O_7(OH)_4{\cdot}3H_2O$. Firstly the 870-860 Ma is the initial age of the supercontinent Rhodinia dispersal and subsequent A-1 type volcanism, which contains Fe, REE, and HFS(High Field Strength elements; Nb, Zr, Y etc.) elements in Fe-rich meta-volcanic rocks dominant Kyemyeongsan Formation, might mineralized allanite. Another synthesis is that regional metamorphism at late Paleozoic 300-280 Ma(Cho et al., 2002) might cause allanite mineralization. Also pegmatite REE mineralization highly related to the granite intrusion over the Chungju area in Jurassic(190 Ma; Koh et al., 2012). Otherwise above all, A-1 type volcanism at the same time of the Kyemyeongsan Formation development, regional metamorphism and pegmatite, might have caused REE mineralization. Although REE ore bodies display a close spatial association, each ore bodies display temporal distinction, different mineral assemblage and environment of ore formation.

Determinants of Consumer Responses to Retail Out-of-Stocks (점포내 품절상황에서 소비자 반응행동유형별 결정요인)

  • Chun, Dal-Young;Choi, Jong-Rae;Joo, Young-Jin
    • Journal of Distribution Research
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    • v.16 no.4
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    • pp.29-64
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    • 2011
  • Overview of Research: Product availability is one of important competences of store to fulfill consumer needs. If stock-outs which means a product what consumer wants to buy is not available occurs, consumer will face decision-making uncertainty that leads to consumer's negative responses such as consumer dissatisfaction on store. Stockouts was much studied in the field of academia as well as practice in other countries. However, stock-outs has not been researched at all in Marketing and/or Distribution area in Korea. The main objectives of this study are to find out determinants of consumer responses such as Substitute, Delay, and Leave(SDL) when consumer encounters out-of-stock situation and then to examine the effects of these factors on consumer responses. Specifically, this study focuses on situational characteristics(e.g., purchase urgency and surprise), store characteristics (e.g., product assortment and store convenience), and consumer characteristics (e.g., brand loyalty and store loyalty). Then, this study empirically investigates relationships these factors with consumers behaviors such as product substitution, purchase delay, and store switching.

    shows the research model of this study. To accomplish above-mentioned research objectives, the following ten hypotheses were proposed and verified : ${\bullet}$ H 1 : When out-of-stock situation occurs, purchase urgency will increase product substitution but will decrease purchase delay and store switching among consumer responses. ${\bullet}$ H 2 When out-of-stock situation occurs, surprise will decrease product substitution and purchase delay but will Increase store switching among consumer responses. ${\bullet}$ H 3 : When out-of-stock situation occurs, purchase quantities will increase product substitution and store switching but will decrease purchase delay among consumer responses. ${\bullet}$ H 4 : When out-of-stock situation occurs, pre-purchase plan will decrease product substitution but will increase purchase delay and store switching among consumer responses. ${\bullet}$ H 5 : When out-of-stock situation occurs, product assortment will increase product substitution but will decrease purchase delay and store switching among consumer responses. ${\bullet}$ H 6 : When out-of-stock situation occurs, competitive store price image will increase product substitution and purchase delay but will decrease store switching among consumer responses. ${\bullet}$ H 7 : When out-of-stock situation occurs, store convenience will increase product substitution but will decrease purchase delay and store switching among consumer responses. ${\bullet}$ H 8 : When out-of-stock situation occurs, salesperson services will increase product substitution but will decrease purchase delay and store switching among consumer responses. ${\bullet}$ H 9 : When out-of-stock situation occurs, brand loyalty will decrease product substitution but will increase purchase delay and store switching among consumer responses. ${\bullet}$ H 10 When out-of-stock situation occurs, store loyalty will increase product substitution and purchase delay but will decrease store switching among consumer responses. Analysis: Data were collected from 353 respondents who experienced out-of-stock situations in various store types such as large discount stores, supermarkets, etc. Research model and hypotheses were verified using multinomial logit(MNL) analysis. Results and Implications: is the estimation results of l\1NL model, and
    shows the marginal effects for each determinant to consumer's responses(SDL). Significant statistical results were as follows. Purchase urgency, purchase quantities, pre-purchase plan, product assortment, store price image, brand loyalty, and store loyalty were turned out to be significant determinants to influence consumer alternative behaviors in case of out-of-stock situation. Specifically, first, product substitution behavior was triggered by purchase urgency, surprise, purchase quantities, pre-purchase plan, product assortment, store price image, brand loyalty, and store loyalty. Second, purchase delay behavior was led by purchase urgency, purchase quantities, and brand loyalty. Third, store switching behavior was influenced by purchase urgency, purchase quantities, pre-purchase plan, product assortment, store price image, brand loyalty, and store loyalty. Finally, when out-of-stock situation occurs, store convenience and salesperson service did not have significant effects on consumer alternative responses.

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  • The way to make training data for deep learning model to recognize keywords in product catalog image at E-commerce (온라인 쇼핑몰에서 상품 설명 이미지 내의 키워드 인식을 위한 딥러닝 훈련 데이터 자동 생성 방안)

    • Kim, Kitae;Oh, Wonseok;Lim, Geunwon;Cha, Eunwoo;Shin, Minyoung;Kim, Jongwoo
      • Journal of Intelligence and Information Systems
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      • v.24 no.1
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      • pp.1-23
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      • 2018
    • From the 21st century, various high-quality services have come up with the growth of the internet or 'Information and Communication Technologies'. Especially, the scale of E-commerce industry in which Amazon and E-bay are standing out is exploding in a large way. As E-commerce grows, Customers could get what they want to buy easily while comparing various products because more products have been registered at online shopping malls. However, a problem has arisen with the growth of E-commerce. As too many products have been registered, it has become difficult for customers to search what they really need in the flood of products. When customers search for desired products with a generalized keyword, too many products have come out as a result. On the contrary, few products have been searched if customers type in details of products because concrete product-attributes have been registered rarely. In this situation, recognizing texts in images automatically with a machine can be a solution. Because bulk of product details are written in catalogs as image format, most of product information are not searched with text inputs in the current text-based searching system. It means if information in images can be converted to text format, customers can search products with product-details, which make them shop more conveniently. There are various existing OCR(Optical Character Recognition) programs which can recognize texts in images. But existing OCR programs are hard to be applied to catalog because they have problems in recognizing texts in certain circumstances, like texts are not big enough or fonts are not consistent. Therefore, this research suggests the way to recognize keywords in catalog with the Deep Learning algorithm which is state of the art in image-recognition area from 2010s. Single Shot Multibox Detector(SSD), which is a credited model for object-detection performance, can be used with structures re-designed to take into account the difference of text from object. But there is an issue that SSD model needs a lot of labeled-train data to be trained, because of the characteristic of deep learning algorithms, that it should be trained by supervised-learning. To collect data, we can try labelling location and classification information to texts in catalog manually. But if data are collected manually, many problems would come up. Some keywords would be missed because human can make mistakes while labelling train data. And it becomes too time-consuming to collect train data considering the scale of data needed or costly if a lot of workers are hired to shorten the time. Furthermore, if some specific keywords are needed to be trained, searching images that have the words would be difficult, as well. To solve the data issue, this research developed a program which create train data automatically. This program can make images which have various keywords and pictures like catalog and save location-information of keywords at the same time. With this program, not only data can be collected efficiently, but also the performance of SSD model becomes better. The SSD model recorded 81.99% of recognition rate with 20,000 data created by the program. Moreover, this research had an efficiency test of SSD model according to data differences to analyze what feature of data exert influence upon the performance of recognizing texts in images. As a result, it is figured out that the number of labeled keywords, the addition of overlapped keyword label, the existence of keywords that is not labeled, the spaces among keywords and the differences of background images are related to the performance of SSD model. This test can lead performance improvement of SSD model or other text-recognizing machine based on deep learning algorithm with high-quality data. SSD model which is re-designed to recognize texts in images and the program developed for creating train data are expected to contribute to improvement of searching system in E-commerce. Suppliers can put less time to register keywords for products and customers can search products with product-details which is written on the catalog.

    Study of Patient Teaching in The Clinical Area (간호원의 환자교육 활동에 관한 연구)

    • 강규숙
      • Journal of Korean Academy of Nursing
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      • v.2 no.1
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      • pp.3-33
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      • 1971
    • Nursing of today has as one of its objectives the solving of problems related to human needs arising from the demands of a rapidly changing society. This nursing objective, I believe, can he attained by the appropriate application of scientific principles in the giving of comprehensive nursing care. Comprehensive nursing care may be defined as nursing care which meets all of the patient's needs. the needs of patients are said to fall into five broad categories: physical needs, psychological needs, environmental needs, socio-economic needs, and teaching needs. Most people who become ill have adjustment problems related to their new situation. Because patient teaching is one of the most important functions of professional nursing, the success of this teaching may be used as a gauge for evaluating comprehensive nursing care. This represents a challenge foe the future. A questionnaire consisting of 67 items was distributed to 200 professional nurses working ill direct patient care at Yonsei University Medical Center in Seoul, Korea. 160 (80,0%) nurses of the total sample returned completed questionnaires 81 (50.6%) nurses were graduates of 3 fear diploma courser 79 (49.4%) nurses were graduates of 4 year collegiate nursing schools in Korea 141 (88,1%) nurses had under 5 years of clinical experience in a medical center, while 19 (11.9%) nurses had more than 5years of clinical experience. Three hypotheses were tested: 1. “Nurses had high levels of concept and knowledge toward patient teaching”-This was demonstrated by the use of a statistical method, the mean average. 2. “Nurses graduating from collegiate programs and diploma school programs of nursing show differences in concepts and knowledge toward patient teaching”-This was demonstrated by a statistical method, the mean average, although the results showed little difference between the two groups. 3. “Nurses having different amounts of clinical experience showed differences in concepts and knowledge toward patient teaching”-This was demonstrated by the use of a statistical method, the mean average. 2. “Nurses graduating from collegiate programs and diploma school programs of nursing show differences in concepts and knowledge toward patient teaching”-This was demonstrated by a statistical method, the mean average, although the results showed little difference between the two groups. 3. “Nurses having different amounts of clinical experience showed differences in concepts and knowledge toward patient teaching”-This was demonstrated by the use of the T-test. Conclusions of this study are as follow: Before attempting the explanation, of the results, the questionnaire will he explained. The questionnaire contained 67 questions divided into 9 sections. These sections were: concept, content, time, prior preparation, method, purpose, condition, evaluation, and recommendations for patient teaching. 1. The nurse's concept of patient teaching: Most of the nurses had high levels of concepts and knowledge toward patient teaching. Though nursing service was task-centered at the turn of the century, the emphasis today is put on patient-centered nursing. But we find some of the nurses (39.4%) still are task-centered. After, patient teaching, only a few of the nurses (14.4%) checked this as “normal teaching.”It seems therefore that patient teaching is often done unconsciously. Accordingly it would he desirable to have correct concepts and knowledge of teaching taught in schools of nursing. 2. Contents of patient teaching: Most nurses (97.5%) had good information about content of patient teaching. They teach their patients during admission about their diseases, tests, treatments, and before discharge give nurses instruction about simple nursing care, personal hygiene, special diets, rest and sleep, elimination etc. 3. Time of patient teaching: Teaching can be accomplished even if there is no time set aside specifically for it. -a large part of the nurse's teaching can be done while she is giving nursing care. If she believes she has to wait for time free from other activities, she may miss many teaching opportunities. But generally proper time for patient teaching is in the midmorning or midafternoon since one and a half or two hours required. Nurses meet their patients in all stages of health: often tile patient is in a condition in which learning is impossible-pain, mental confusion, debilitation, loss of sensory perception, fear and anxiety-any of these conditions may preclude the possibility of successful teaching. 4. Prior preparation for patient teaching: The teaching aids, nurses use are charts (53.1%), periodicals (23.8%), and books (7.0%) Some of the respondents (28.1%) reported that they had had good preparation for the teaching which they were doing, others (27.5%) reported adequate preparation, and others (43.8%) reported that their preparation for teaching was inadequate. If nurses have advance preparation for normal teaching and are aware of their objectives in teaching patients, they can do effective teaching. 5. Method of patient teaching: The methods of individual patient teaching, the nurses in this study used, were conversation (55.6%) and individual discussion (19.2%) . And the methods of group patient teaching they used were demonstration (42.3%) and lecture (26.2%) They should also he prepared to use pamphlet and simple audio-visual aids for their teaching. 6. Purposes of patient teaching: The purposes of patient teaching is to help the patient recover completely, but the majority of the respondents (40.6%) don't know this. So it is necessary for them to understand correctly the purpose of patient teaching and nursing care. 7. Condition of patient teaching: The majority of respondents (75.0%) reported there were some troubles in teaching uncooperative patients. It would seem that the nurse's leaching would be improved if, in her preparation, she was given a better understanding of the patient and communication skills. The majority of respondents in the total group, felt teaching is their responsibility and they should teach their patient's family as well as the patient. The place for teaching is most often at the patient's bedside (95.6%) but the conference room (3.1%) is also used. It is important that privacy be provided in learning situations with involve personal matters. 8. Evaluation of patient teaching: The majority of respondents (76.3%,) felt leaching is a highly systematic and organized function requiring special preparation in a college or university, they have the idea that teaching is a continuous and ever-present activity of all people throughout their lives. The suggestion mentioned the most frequently for improving preparation was a course in patient teaching included in the basic nursing program. 9. Recommendations: 1) It is recommended, that in clinical nursing, patient teaching be emphasized. 2) It is recommended, that insertive education the concepts and purposes of patient teaching he renewed for all nurses. In addition to this new knowledge, methods and materials which can be applied to patient teaching should be given also. 3) It is recommended, in group patient teaching, we try to embark on team teaching.

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    Empirical Analysis on Bitcoin Price Change by Consumer, Industry and Macro-Economy Variables (비트코인 가격 변화에 관한 실증분석: 소비자, 산업, 그리고 거시변수를 중심으로)

    • Lee, Junsik;Kim, Keon-Woo;Park, Do-Hyung
      • Journal of Intelligence and Information Systems
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      • v.24 no.2
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      • pp.195-220
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      • 2018
    • In this study, we conducted an empirical analysis of the factors that affect the change of Bitcoin Closing Price. Previous studies have focused on the security of the block chain system, the economic ripple effects caused by the cryptocurrency, legal implications and the acceptance to consumer about cryptocurrency. In various area, cryptocurrency was studied and many researcher and people including government, regardless of country, try to utilize cryptocurrency and applicate to its technology. Despite of rapid and dramatic change of cryptocurrencies' price and growth of its effects, empirical study of the factors affecting the price change of cryptocurrency was lack. There were only a few limited studies, business reports and short working paper. Therefore, it is necessary to determine what factors effect on the change of closing Bitcoin price. For analysis, hypotheses were constructed from three dimensions of consumer, industry, and macroeconomics for analysis, and time series data were collected for variables of each dimension. Consumer variables consist of search traffic of Bitcoin, search traffic of bitcoin ban, search traffic of ransomware and search traffic of war. Industry variables were composed GPU vendors' stock price and memory vendors' stock price. Macro-economy variables were contemplated such as U.S. dollar index futures, FOMC policy interest rates, WTI crude oil price. Using above variables, we did times series regression analysis to find relationship between those variables and change of Bitcoin Closing Price. Before the regression analysis to confirm the relationship between change of Bitcoin Closing Price and the other variables, we performed the Unit-root test to verifying the stationary of time series data to avoid spurious regression. Then, using a stationary data, we did the regression analysis. As a result of the analysis, we found that the change of Bitcoin Closing Price has negative effects with search traffic of 'Bitcoin Ban' and US dollar index futures, while change of GPU vendors' stock price and change of WTI crude oil price showed positive effects. In case of 'Bitcoin Ban', it is directly determining the maintenance or abolition of Bitcoin trade, that's why consumer reacted sensitively and effected on change of Bitcoin Closing Price. GPU is raw material of Bitcoin mining. Generally, increasing of companies' stock price means the growth of the sales of those companies' products and services. GPU's demands increases are indirectly reflected to the GPU vendors' stock price. Making an interpretation, a rise in prices of GPU has put a crimp on the mining of Bitcoin. Consequently, GPU vendors' stock price effects on change of Bitcoin Closing Price. And we confirmed U.S. dollar index futures moved in the opposite direction with change of Bitcoin Closing Price. It moved like Gold. Gold was considered as a safe asset to consumers and it means consumer think that Bitcoin is a safe asset. On the other hand, WTI oil price went Bitcoin Closing Price's way. It implies that Bitcoin are regarded to investment asset like raw materials market's product. The variables that were not significant in the analysis were search traffic of bitcoin, search traffic of ransomware, search traffic of war, memory vendor's stock price, FOMC policy interest rates. In search traffic of bitcoin, we judged that interest in Bitcoin did not lead to purchase of Bitcoin. It means search traffic of Bitcoin didn't reflect all of Bitcoin's demand. So, it implies there are some factors that regulate and mediate the Bitcoin purchase. In search traffic of ransomware, it is hard to say concern of ransomware determined the whole Bitcoin demand. Because only a few people damaged by ransomware and the percentage of hackers requiring Bitcoins was low. Also, its information security problem is events not continuous issues. Search traffic of war was not significant. Like stock market, generally it has negative in relation to war, but exceptional case like Gulf war, it moves stakeholders' profits and environment. We think that this is the same case. In memory vendor stock price, this is because memory vendors' flagship products were not VRAM which is essential for Bitcoin supply. In FOMC policy interest rates, when the interest rate is low, the surplus capital is invested in securities such as stocks. But Bitcoin' price fluctuation was large so it is not recognized as an attractive commodity to the consumers. In addition, unlike the stock market, Bitcoin doesn't have any safety policy such as Circuit breakers and Sidecar. Through this study, we verified what factors effect on change of Bitcoin Closing Price, and interpreted why such change happened. In addition, establishing the characteristics of Bitcoin as a safe asset and investment asset, we provide a guide how consumer, financial institution and government organization approach to the cryptocurrency. Moreover, corroborating the factors affecting change of Bitcoin Closing Price, researcher will get some clue and qualification which factors have to be considered in hereafter cryptocurrency study.

    An Analysis of the Specialist's Preference for the Model of Park-Based Mixed-Use Districts in Securing Urban Parks and Green Spaces Via Private Development (민간개발 주도형 도시공원.녹지 확보를 위한 공원복합용도지구 모형에 대한 전문가 선호도 분석)

    • Lee, Jeung-Eun;Cho, Se-Hwan
      • Journal of the Korean Institute of Landscape Architecture
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      • v.39 no.6
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      • pp.1-11
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      • 2011
    • The research was aimed to verify the feasibility of the model of Park-Based Mixed-Use Districts(PBMUD) around urban large park to secure private-based urban parks through the revision of the urban zoning system. The PBMUD is a type of urban zoning district in which park-oriented land use is mixed with the urban land uses of residents, advertising, business, culture, education and research. The PBMUD, delineated from and based on a new paradigm of landscape urbanism, is a new urban strategy to secure urban parks and to cultivate urban regeneration around parks and green spaces to enhance the quality of the urban landscape and to ameliorate urban environmental disasters like climate change. This study performed a questionnaire survey and analysis after a review of literature related to PBMUD. The study looked for specialists in the fields of urban planning and landscape architecture such as officials, researchers and engineers to respond to the questionnaire, which asked about degree of preference. The conclusions of this study were as follows. Firstly, specialists prefer the PBMUD at 79.3% for to 20.7% against ratio, indicating the feasibility of the model of PBMUD. The second, the most preferable reasons for the model, were the possibility of securing park space around urban parks and green spaces that assures access to park and communication with each area. The third, the main reason for non-preference for the model, was a lack of understanding of PBMUD added to the problems of unprofitable laws and regulations related to urban planning and development. These proposed a revision of the related laws and regulations such as the laws for planning and use of national land, laws for architecture etc. The fourth, the most preferred type of PBMUD, was cultural use mixed with park use in every kind of mix of land use. The degree of preference was lower in the order of use of commercial, residential, business, and education(research) when mixed with park use. The number of mixed-use amenities with in the park was found to be an indicator determining preference. The greater the number, the lower was preference frequencies, especially when related to research and business use. The fifth, the preference frequencies of the more than 70% among the respondents to the mixed-use ratio between park use and the others, was in a ratio of 60% park use and 40% other urban use. These research results will help to launch new future research subjects on the revision of zoning regulations in the laws for the planning and uses of national land and architectural law as well as criteria and indicators of subdivision planning as related to a PBMUD model.

    A Study on the Problems and Resolutions of Provisions in Korean Commercial Law related to the Aircraft Operator's Liability of Compensation for Damages to the Third Party (항공기운항자의 지상 제3자 손해배상책임에 관한 상법 항공운송편 규정의 문제점 및 개선방안)

    • Kim, Ji-Hoon
      • The Korean Journal of Air & Space Law and Policy
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      • v.29 no.2
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      • pp.3-54
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      • 2014
    • The Republic of Korea enacted the Air Transport Act in Commercial Law which was entered into force in November, 2011. The Air Transport Act in Korean Commercial Law was established to regulate domestic carriage by air and damages to the third party which occur within the territorial area caused by aircraft operations. There are some problems to be reformed in the Provisions of Korean Commercial Law for the aircraft operator's liability of compensation for damages to the third party caused by aircraft operation as follows. First, the aircraft operator's liability of compensation for damages needs to be improved because it is too low to compensate adequately to the third party damaged owing to the aircraft operation. Therefore, the standard of classifying per aircraft weight is required to be detailed from the current 4-tier into 10-tier and the total limited amount of liability is also in need of being increased to the maximum 7-hundred-million SDR. In addition, the limited amount of liability to the personal damage is necessary to be risen from the present 125,000 SDR to 625,000 SDR according to the recent rate of prices increase. This is the most desirable way to improve the current provisions given the ordinary insurance coverage per one aircraft accident and various specifications of recent aircraft in order to compensate the damaged appropriately. Second, the aircraft operator shall be liable without fault to damages caused by terrorism such as hijacking, attacking an aircraft and utilizing it as means of attack like the 9 11 disaster according to the present Air Transport Act in Korean Commercial Law. Some argue that it is too harsh to aircraft operators and irrational, but given they have also some legal duties of preventing terrorism and in respect of helping the third party damaged, it does not look too harsh or irrational. However, it should be amended into exempting aircraft operator's liability when the terrorism using of an aircraft by well-organized terrorists group happens like 9 11 disaster in view of balancing the interest between the aircraft operator and the third party damaged. Third, considering the large scale of the damage caused by the aircraft operation usually aircraft accident, it is likely that many people damaged can be faced with a financial crisis, and the provision of advance payment for air carrier's liability of compensation also needs to be applied to the case of aircraft operator's liability. Fourth, the aircraft operator now shall be liable to the damages which occur in land or water except air according to the current Air Transport Act of Korean Commercial Law. However, because the damages related to the aircraft operation in air caused by another aircraft operation are not different from those in land or water. Therefore, the term of 'on the surface' should be eliminated in the term of 'third parties on the surface' in order to make the damages by the aircraft operation in air caused by another aircraft operation compensable by Air Transport Act of Korean Commercial Law. It is desired that the Air Transport Act in Commercial Law including the clauses related to the aircraft operator's liability of compensation for damages to the third party be developed continually through the resolutions about its problems mentioned above for compensating the third party damaged appropriately and balancing the interest between the damaged and the aircraft operator.

    A Study on Commodity Asset Investment Model Based on Machine Learning Technique (기계학습을 활용한 상품자산 투자모델에 관한 연구)

    • Song, Jin Ho;Choi, Heung Sik;Kim, Sun Woong
      • Journal of Intelligence and Information Systems
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      • v.23 no.4
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      • pp.127-146
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      • 2017
    • Services using artificial intelligence have begun to emerge in daily life. Artificial intelligence is applied to products in consumer electronics and communications such as artificial intelligence refrigerators and speakers. In the financial sector, using Kensho's artificial intelligence technology, the process of the stock trading system in Goldman Sachs was improved. For example, two stock traders could handle the work of 600 stock traders and the analytical work for 15 people for 4weeks could be processed in 5 minutes. Especially, big data analysis through machine learning among artificial intelligence fields is actively applied throughout the financial industry. The stock market analysis and investment modeling through machine learning theory are also actively studied. The limits of linearity problem existing in financial time series studies are overcome by using machine learning theory such as artificial intelligence prediction model. The study of quantitative financial data based on the past stock market-related numerical data is widely performed using artificial intelligence to forecast future movements of stock price or indices. Various other studies have been conducted to predict the future direction of the market or the stock price of companies by learning based on a large amount of text data such as various news and comments related to the stock market. Investing on commodity asset, one of alternative assets, is usually used for enhancing the stability and safety of traditional stock and bond asset portfolio. There are relatively few researches on the investment model about commodity asset than mainstream assets like equity and bond. Recently machine learning techniques are widely applied on financial world, especially on stock and bond investment model and it makes better trading model on this field and makes the change on the whole financial area. In this study we made investment model using Support Vector Machine among the machine learning models. There are some researches on commodity asset focusing on the price prediction of the specific commodity but it is hard to find the researches about investment model of commodity as asset allocation using machine learning model. We propose a method of forecasting four major commodity indices, portfolio made of commodity futures, and individual commodity futures, using SVM model. The four major commodity indices are Goldman Sachs Commodity Index(GSCI), Dow Jones UBS Commodity Index(DJUI), Thomson Reuters/Core Commodity CRB Index(TRCI), and Rogers International Commodity Index(RI). We selected each two individual futures among three sectors as energy, agriculture, and metals that are actively traded on CME market and have enough liquidity. They are Crude Oil, Natural Gas, Corn, Wheat, Gold and Silver Futures. We made the equally weighted portfolio with six commodity futures for comparing with other commodity indices. We set the 19 macroeconomic indicators including stock market indices, exports & imports trade data, labor market data, and composite leading indicators as the input data of the model because commodity asset is very closely related with the macroeconomic activities. They are 14 US economic indicators, two Chinese economic indicators and two Korean economic indicators. Data period is from January 1990 to May 2017. We set the former 195 monthly data as training data and the latter 125 monthly data as test data. In this study, we verified that the performance of the equally weighted commodity futures portfolio rebalanced by the SVM model is better than that of other commodity indices. The prediction accuracy of the model for the commodity indices does not exceed 50% regardless of the SVM kernel function. On the other hand, the prediction accuracy of equally weighted commodity futures portfolio is 53%. The prediction accuracy of the individual commodity futures model is better than that of commodity indices model especially in agriculture and metal sectors. The individual commodity futures portfolio excluding the energy sector has outperformed the three sectors covered by individual commodity futures portfolio. In order to verify the validity of the model, it is judged that the analysis results should be similar despite variations in data period. So we also examined the odd numbered year data as training data and the even numbered year data as test data and we confirmed that the analysis results are similar. As a result, when we allocate commodity assets to traditional portfolio composed of stock, bond, and cash, we can get more effective investment performance not by investing commodity indices but by investing commodity futures. Especially we can get better performance by rebalanced commodity futures portfolio designed by SVM model.

    Optimization of Multiclass Support Vector Machine using Genetic Algorithm: Application to the Prediction of Corporate Credit Rating (유전자 알고리즘을 이용한 다분류 SVM의 최적화: 기업신용등급 예측에의 응용)

    • Ahn, Hyunchul
      • Information Systems Review
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      • v.16 no.3
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      • pp.161-177
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      • 2014
    • Corporate credit rating assessment consists of complicated processes in which various factors describing a company are taken into consideration. Such assessment is known to be very expensive since domain experts should be employed to assess the ratings. As a result, the data-driven corporate credit rating prediction using statistical and artificial intelligence (AI) techniques has received considerable attention from researchers and practitioners. In particular, statistical methods such as multiple discriminant analysis (MDA) and multinomial logistic regression analysis (MLOGIT), and AI methods including case-based reasoning (CBR), artificial neural network (ANN), and multiclass support vector machine (MSVM) have been applied to corporate credit rating.2) Among them, MSVM has recently become popular because of its robustness and high prediction accuracy. In this study, we propose a novel optimized MSVM model, and appy it to corporate credit rating prediction in order to enhance the accuracy. Our model, named 'GAMSVM (Genetic Algorithm-optimized Multiclass Support Vector Machine),' is designed to simultaneously optimize the kernel parameters and the feature subset selection. Prior studies like Lorena and de Carvalho (2008), and Chatterjee (2013) show that proper kernel parameters may improve the performance of MSVMs. Also, the results from the studies such as Shieh and Yang (2008) and Chatterjee (2013) imply that appropriate feature selection may lead to higher prediction accuracy. Based on these prior studies, we propose to apply GAMSVM to corporate credit rating prediction. As a tool for optimizing the kernel parameters and the feature subset selection, we suggest genetic algorithm (GA). GA is known as an efficient and effective search method that attempts to simulate the biological evolution phenomenon. By applying genetic operations such as selection, crossover, and mutation, it is designed to gradually improve the search results. Especially, mutation operator prevents GA from falling into the local optima, thus we can find the globally optimal or near-optimal solution using it. GA has popularly been applied to search optimal parameters or feature subset selections of AI techniques including MSVM. With these reasons, we also adopt GA as an optimization tool. To empirically validate the usefulness of GAMSVM, we applied it to a real-world case of credit rating in Korea. Our application is in bond rating, which is the most frequently studied area of credit rating for specific debt issues or other financial obligations. The experimental dataset was collected from a large credit rating company in South Korea. It contained 39 financial ratios of 1,295 companies in the manufacturing industry, and their credit ratings. Using various statistical methods including the one-way ANOVA and the stepwise MDA, we selected 14 financial ratios as the candidate independent variables. The dependent variable, i.e. credit rating, was labeled as four classes: 1(A1); 2(A2); 3(A3); 4(B and C). 80 percent of total data for each class was used for training, and remaining 20 percent was used for validation. And, to overcome small sample size, we applied five-fold cross validation to our dataset. In order to examine the competitiveness of the proposed model, we also experimented several comparative models including MDA, MLOGIT, CBR, ANN and MSVM. In case of MSVM, we adopted One-Against-One (OAO) and DAGSVM (Directed Acyclic Graph SVM) approaches because they are known to be the most accurate approaches among various MSVM approaches. GAMSVM was implemented using LIBSVM-an open-source software, and Evolver 5.5-a commercial software enables GA. Other comparative models were experimented using various statistical and AI packages such as SPSS for Windows, Neuroshell, and Microsoft Excel VBA (Visual Basic for Applications). Experimental results showed that the proposed model-GAMSVM-outperformed all the competitive models. In addition, the model was found to use less independent variables, but to show higher accuracy. In our experiments, five variables such as X7 (total debt), X9 (sales per employee), X13 (years after founded), X15 (accumulated earning to total asset), and X39 (the index related to the cash flows from operating activity) were found to be the most important factors in predicting the corporate credit ratings. However, the values of the finally selected kernel parameters were found to be almost same among the data subsets. To examine whether the predictive performance of GAMSVM was significantly greater than those of other models, we used the McNemar test. As a result, we found that GAMSVM was better than MDA, MLOGIT, CBR, and ANN at the 1% significance level, and better than OAO and DAGSVM at the 5% significance level.


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