• 한국컴퓨터정보학회논문지
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• 제25권5호
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• pp.47-56
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• 2020

주가지수는 한 국가의 경제 지표뿐만 아니라 투자판단의 지표로도 활용되므로 이를 예측하는 연구가 지속해서 진행되고 있다. 주가지수 예측을 하는 작업은 기술적, 경제적 및 심리적 요인 등이 반영된 것으로 예측의 정확도를 위해서는 복합적 요인을 고려해야 한다. 따라서 지수의 변동에 영향을 미치는 요인들을 선별하여 반영한 주가지수 예측모델연구가 필요하다. 이와 관련한 기존 연구에서는 시장의 변동을 만들어 내는 뉴스 정보 또는 거시 경제 지표를 각각 이용하거나, 몇 가지의 지표 조합만을 반영한 예측 연구가 대부분이었다. 따라서 본 연구에서는 미국 다우존스지수 예측을 위해 뉴스 정보의 감성 분석과 다양한 거시경제지표를 고려하여 효과적인 지표 조합을 제시하고자 한다. 뉴스 정보의 감성 분석은 최신 자연어처리 기법인 BERT와 NLTK VADER를 사용하고, 예측모델은 주가예측모델로 적합하다고 알려진 딥러닝 예측모델 LSTM을 적용하여 가장 효과적인 지표 조합을 제시했다.

• 한국재료학회지
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• 제22권4호
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• pp.207-210
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• 2012

The preparation of $Sm_2O_3$ doped $CeO_2$ in Igepal CO-520/cyclohexane reverse micelle solutions has been studied. In the present work, we synthesized nanosized $Sm_2O_3$ doped $CeO_2$ powders by reverse micelle process using aqueous ammonia as the precipitant; hydroxide precursor was obtained from nitrate solutions dispersed in the nanosized aqueous domains of a micro emulsion consisting of cyclohexane as the oil phase, and poly (xoyethylene) nonylphenylether (Igepal CO-520) as the non-ionic surfactant. The synthesized and calcined powders were characterized by Thermogravimetry-differential thermal analysis (TGA-DTA), X-ray diffraction analysis (XRD), and Transmission electron microscopy (TEM). The crystallite size was found to increase with increase in water to surfactant (R) molar ratio. Average particle size and distribution of the synthesized $Sm_2O_3$ doped $CeO_2$ were below 10 nm and narrow, respectively. TG-DTA analysis shows that phase of $Sm_2O_3$ doped $CeO_2$ nanoparticles changed from monoclinic to tetragonal at approximately $560^{\circ}C$. The phase of the synthesized $Sm_2O_3$ doped $CeO_2$ with heating to $600^{\circ}C$ for 30 min was tetragonal $CeO_2$. This study revealed that the particle formation process in reverse micelles is based on a two step model. The rapid first step is the complete reduction of the metal to the zero valence state. The second step is growth, via reagent exchanges between micelles through the inter-micellar exchange.

• 디지털융복합연구
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• 제16권5호
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• pp.137-143
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• 2018

우리나라의 항공여객 운송실적은 지속적으로 성장하고 있다. 본 연구에서는 우리나라 항공여객 운송 실적의 성장추이를 확인하기 위해 시스템다이내믹스를 활용한 항공여객 수요예측 모델을 제안하였다. 항공여객 수요예측은 항공여객 운송수요를 종속변수로 하고 국제항공유가, GDP 및 환율을 외생변수로 하여 시뮬레이션 하였다. 모델의 정확도는 MAPE와 $R^2$를 이용하여 검증하였고 검증 결과 제안된 예측모델은 정확한 예측모델로 확인되었다. 수요예측 결과 국적 항공사의 항공여객 처리실적은 앞으로도 지속적으로 성장하며, 특히 저비용항공사의 수송 분담률이 크게 증가할 것으로 예측되었다. 향후 한국에 진출해 있는 외국계 항공사들의 내국인 처리 실적 및 국적항공사들의 Alliance 체결에 따른 실적 등을 추가하여 보다 정확한 항공여객 수요예측 모델을 제안하고자 한다.

• 한국조경학회지
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• 제19권2호
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• pp.12-22
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• 1991

The purpose of this study is to identify demand and methods of projection, including to prove the variables affecting the fluctuation of visitors and to analyze the relationship between these variables in National Park. Statistical analysis method (Multiple Linear Regression Analysis, ANOVA, and Model diagnostics) was carried out by computer program SAS/pc. 13 variables (1. Total Population, 2. Per Capita PDI, 3. Employment Ratio of S.O.C. & others, 4. NO. of Passenger Car, 5. Length of Roads, 6. Leisure Expenditure of Farm Household, 7. Leisure Expenditure of Urban Household, 8. Price Index, 9. NO. of Bus, 10. Exchange on Dollars, 11. Export, 12. Import, and 13. Visitors in National Park) had been used to this study. The scope of time period is during the last 17 years (1970-1986). The results were as follows; 1) Participation depends only on the specific characteristics of the economic factors (Price Index and Leisure Expenditure of Urban Household). These factors are the importance factors directly affecting the participation of visitors. The statistical Model for projecting the visitors in National Parks is the function of "Visitors in National Parks (thousand)=14915+0.210311*Leisure Expenditure of Urband Household (won)-157.835619*Price Index(1985=100)" 2) The external factors affecting the participation depends upon the interelated features of availability and accessibility (NO. of Passenger Car, Length of Roads, and NO. of Bus) of recreation resources or sites, and the economic factors (Per Capita PDI, Export, and Import). These factors are the factors indirectly affecting the participation of visitors. 3) The participation depends on the specific characteristics of demographic factors (Total Population and Employment Ratio of S.O.C. & others). These factors are the factors indirectly affecting the participation of visitors. 4) The unexpected fluctuation of yearly visitors depends on oil shock or inflation (1971, 1973-1974, 1979-1980), promulgation of national emergency decrees (1971-1972, 1974-1975, 1979-1980), and national events (assassination of president Park's wife, Madame Yuk in 1974 and president Park I 1979).

• 농촌계획
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• 제22권4호
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• pp.103-114
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• 2016

The global trade partners have been diversified and mixed in agricultural market, which is expended the international agri-food market through the Regional Trade Agreement and World Trade Organization, etc. The aim of this study is to derive influential factors for exports increases of agricultural products targeting to Association of South-East Asian Nations (ASEAN). We set the equation for agricultural products exports referred to panel gravity model considering panel fixed effect for controlling endogeneity within variables. The results of this study are the follows; (1) Social economic distance considering international oil price negatively affects in the mushroom model; (2) Korean GDP affects (-) in a mushroom model and (+) in a vegetable model, however, ASEAN's per capita GDP indicates opposite influence in the same model; (3) Relative exchange rate shows negative impact in a vegetable model; (4) The entry status into WTO and the status in force of FTA have converse effects in mushroom and vegetable model, respectively.

• 대한핵의학회지
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• 제20권2호
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• pp.61-71
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• 1986

An iodized oil such as Ethiodol or Lipiodol was selectively retained in the tumor vessels of the large hepatomas as well as in the small daughter hepatomas for long periods following the intra-arterial hepatic injection of such contrast material. The specific aim of the study is to deliver a high internal radiation dose to hepatocellular carcinoma (HCC) in an attempt to control the disease. We were able to replace a small fraction of the stable iodine (I-127) of the 37% iodine in Lipiodol by the $I^{-131}$ with 100% exchange efficiency. $I^{-131}$ labeled Lipiodol was injected through the super-selected tumor feeding artery under superselection or into the proper hepatic arterial level of patients who have malignant hepatomas confirmed by aspiration cytology serum AFP and various imaging modalities. Clinical traial was performed on 43 cases during recent 6 months and follow-up observation was carried out. No severe complications or other adverse reactions were encountered until nowdays. $I^{-131}-Lipiodol$ was stable in vivo and no significant activity was noted in the thyroid, stomach, blood and urine after the injection. Only small fraction of radioisotope activity was noticed in the both side of lungs. Tumor to normal liver radio was very high. Therefore, $I^{-131}-Lipiodol$ (or P-32-Lipiodol) will be effective delivering high internal radiation dose to the tumor while delivering small radiation doses to normal tissues. Labeling, tumor dose calculation and preliminary findings will be presented.

• 대한원격탐사학회:학술대회논문집
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• 대한원격탐사학회 2007년도 Proceedings of ISRS 2007
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• pp.471-474
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• 2007

Eucalyptus plantations play a major role in the China's ecological, social, economic and other aspects and presently China is the second largest producer of Eucalyptus in the world next to Brazil. It was introduced as an ornamental tree during 1890 but later it became a commercial crop. During 1960s large number of Eucalyptus timber were used for railway sleepers and it was also used as shelter belt for rubber trees. It becomes one of the important national resources of commercial timber once the production reached to 5 million $m^{3}/yr$. Through Eucalyptus oil, it brought about 20% of foreign exchange. In the present study, it was aimed to estimate the Eucalyptus growing area in the southern Guangdong in China in terms of aerial extent and changes between 1991 and 2001 using Landsat TM and ETM+ data. Object based classification technique and subsequent temporal change detection analysis were followed to identify the changes between the periods. In the present study, the total area was divided into three classes viz., plantation area with trees, plantation area without trees and others. Object oriented classification was found to be more accurate in the present study. Overall increase of about 23.62 $km^{2}$ was noted between 1991 and 2001 in the plantation area. With reference to the present study area, the growth of Eucalyptus growing area was 7.4% in the 10 year periods. From this study it is clear that the area under Eucalyptus cultivation is growing considerably year by year in China. However, elaborate study must be conducted considering larger areas to accurately predict the growth of Eucalyptus growing areas.

• 한국건축시공학회:학술대회논문집
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• 한국건축시공학회 2009년도 추계 학술논문 발표대회
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• pp.225-229
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• 2009

International construction market has been open to other countries, and it derives the development of our overseas construction industry quantitatively as well as qualitatively. Until now, the major companies have an absolute majority in the overseas construction market, and the small and medium enterprises have had difficulty to get a leadership in the international construction market because of the lack of the technical expertise and the capital strength. Especially in the Middle East Asia, our construction companies has touched off a boom, so our market share also has grown, which derived from the up toward ratchet oil prices and a worldwide boom in real estate development. The small and medium enterprise minority have recognition that the overseas construction market is the major company's native territory. But Data from the existing researches and many statistics indicate the most companies tend to underestimate the capacity and international competitiveness of the small and medium enterprises. As a matter of fact, hundreds of small and medium enterprise cut a conspicuous figure in overseas market. Consequently, it is indispensable to overcome the international financial crisis by revitalizing our overseas construction industry which obtains excellent results in international market. this study suggested the ways to expand overseas bonding capacity of Korean financial institution. This study proposed the Korean government to allow Construction Guarantee (former Korea Construction Financial Cooperative) to deal with foreign exchange so that Construction Guarantee will underwrite the overseas construction bond.

• 한국통신학회논문지
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• 제36권6B호
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• pp.710-719
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• 2011

해운회사에서는 현재 고유가 및 물동량 감소 등의 경영환경변화에 대처하기 위해 경쟁력강화와 경영합리화를 구현하는 전략적 선박자원관리시스템 개발에 대한 관심이 고조되고 있다. 본 논문에서는 SAN(Ship Area Network) 환경에 적합한 선박자원관리시스템을 소개한다. 이 시스템은 선박관계 당사자 요구사항을 분석하여 선주사의 경영전략 실행에 맞도록 설계되었다. 이와 함께 선박의 전 생애주기에 걸쳐서 선박자원에 대한 정보와 지식을 관리할 수 있도록 선박 온톨로지와 기계장치 및 부품에 대한 국제표준인 STEP과 PLIB를 도입할 수 있게 시스템을 설계한 다음, 비즈니스 로직과 사용자 인터페이스를 분리하여 웹기반 ERP(SHERP)로 구현하였다. 본 논문에서 기술하고 있는 시스템은 선박과 선단 운영에 적용할 수 있는 정보시스템으로서 조선산업 서비스화를 지향하는 구체적인 사례가 될 것이다.

• 자원환경지질
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• 제46권1호
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• pp.71-84
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• 2013

대부분의 GH는 전세계 해양퇴적물에서 대부분 산출되며 매장량은 $10^{13}{\sim}20{\times}10^{15}m^3$로 현재 세계 에너지 사용량을 기준으로 근 1,000년에 해당하는 양이다. MH는 전통석유가스자원를 대체할 미래 천연가스자원으로써의 잠재력이 있기 때문에 감압법, 화학첨가제 주입법, 열자극법, $CO_2$-메탄 치환법 등 채굴기술개발이 필요하다. 우리나라의 경우 2014년까지는 시험생산이 가능할 것으로 기대되고 있다. 이를 위하여 생산방법을 비교하고 GH의 분해에 따르는 반응이 복잡하기 때문에 이러한 현상을 예측하는 기술과 효과적이고 환경 친화적인 가스를 생산할 수 있는 기술을 개발하는 것이다.