• Communications for Statistical Applications and Methods
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• 제18권1호
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• pp.23-34
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• 2011

부동산 경매는 최근 새로운 부동산 투자방법 가운데 하나로 자리잡고있다. 이는 부동산 시장의 성장과 더불어 부동산 경매 시장 또한 증가하고 있는 추세에 기인한다 할 수 있다. 본 연구는 부동산 경매에 참여하는 사람 및 기관들에게 가장 중요한 지표라 할 수 있는 낙찰률의 변화를 설명하고 예측하는 모형을 구축하고자 하였다. 월별 평균 낙찰률을 예측하기 위하여 단순한 지역별, 기간별 평균값을 보완하고 의사결정나무 분석을 이용하여 예측오차를 보정하는 방법을 제안하였고 선형회귀모형을 이용하여 개별 경매 물건별 낙찰률을 예측하기 위한 모형을 구축하였다. 구축된 모형은 전국 아파트 경매 물건에 적용하여 예측 모형을 구현하였으며 그 응용방법으로 예측결과에 대한 등급화를 함께 수행하였다.

• 한국농공학회논문집
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• 제52권3호
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• pp.39-45
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• 2010

Quantification of carbon absorption and understanding the human induced land use changes (LUC) forms one of the major study with respect to global climatic changes. An attempt study has been made to quantify the carbon absorption by LUC through remote sensing technology. The Landsat imagery four time periods was classified with the hybrid classification method in order to quantify carbon absorption by LUC. Thereafter, for estimating the amount of carbon absorption, the stand biomass of forest was estimated with the total weight, which was the sum of individual tree weight. Individual tree volumes could be estimated with the crown width extracted from digital forest cover type map. In particular, the carbon conversion index and the ratio of the $CO_2$ molecular weight to the C atomic weight, reported in the IPCC guideline, was used to convert the stand biomass into the amount of carbon absorption. Total carbon absorption has been modeled by taking areal estimates of LUC of four time periods and carbon factors for land use type and standing biomass. Results of this study, through LUC suggests that over a period of construction, 7.10 % of forest and 9.43 % of barren were converted into urban. In the conversion process, there has been a loss of 6.66 t/ha/y (7.94 %) of carbon absorption from the study area.

• 한국컴퓨터정보학회논문지
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• 제26권2호
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• pp.61-68
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• 2021

최근 악성코드와 정상 바이너리를 분류하기 위해 기계학습을 이용하는 기술이 다양하게 연구되고 있다. 효과적인 기계학습을 위해서는 악성코드와 정상 바이너리를 식별하기 위한 Feature를 잘 추출하는 것이 무엇보다 중요하다. 본 논문에서는 재귀적인 방법을 이용하여 기계학습에 활용하기 위한 Feature 추출 방법인 RFA(Recursive Feature Addition) 제안한다. 제안하는 방법은 기계학습의 성능을 극대화 하기 위해 개별 Feature를 대상으로 재귀적인 방법을 사용하여 최종 Feature Set을 선정한다. 세부적으로는 매 단계마다 개별 Feature 중 최고성능을 내는 Feature를 추출하여, 추출한 Feature를 결합하는 방법을 사용한다. 제안하는 방법을 활용하여 Decision tree, SVM, Random forest, KNN등의 기계학습 알고리즘에 적용한 결과 단계가 지속될수록 기계학습의 성능이 향상되는 것을 검증하였다.

• Parasites, Hosts and Diseases
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• 제47권3호
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• pp.235-241
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• 2009

The aim of this study was to estimate the benefit from repeated examinations in the diagnosis of enterobiasis in nursery school groups, and to test the effectiveness of individual-based risk predictions using different methods. A total of 604 children were examined using double, and 96 using triple, anal swab examinations. The questionnaires for parents, structured observations, and interviews with supervisors were used to identify factors of possible infection risk. In order to model the risk of enterobiasis at individual level, a similarity-based machine learning and prediction software Constud was compared with data mining methods in the Statistica 8 Data Miner software package. Prevalence according to a single examination was 22.5%; the increase as a result of double examinations was 8.2%. Single swabs resulted in an estimated prevalence of 20.1% among children examined 3 times; double swabs increased this by 10.1%, and triple swabs by 7.3%. Random forest classification, boosting classification trees, and Constud correctly predicted about 2/3 of the results of the second examination. Constud estimated a mean prevalence of 31.5% in groups. Constud was able to yield the highest overall fit of individual-based predictions while boosting classification tree and random forest models were more effective in recognizing Enterobius positive persons. As a rule, the actual prevalence of enterobiasis is higher than indicated by a single examination. We suggest using either the values of the mean increase in prevalence after double examinations compared to single examinations or group estimations deduced from individual-level modelled risk predictions.

• 한국산림과학회지
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• 제110권3호
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• pp.295-307
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• 2021

본 연구는 일본잎갈나무 인공림에서 천연하종갱신을 이용한 후계림 조성 방법을 제안하고자 수행되었다. 이를 위해 2016년 경기도 가평에 모수작업과 개벌작업을 실시하여 시험지를 조성하고, 2014년에 조성된 경상북도 봉화의 시험지와 함께 천연갱신지의 종자결실 및 종자낙하 특성을 분석하였다. 그 결과, 결실이 좋은 해에 V영급 일본잎갈나무의 개체 목당 종자 수는 690,340립이며, 모수가 ha당 25본인 일본잎갈나무 천연갱신지에서는 ha당 1,380만립의 종자가 결실되는 것으로 추정되었다. 종자의 비산은 9월부터 시작되었으며, 11월까지 낙하된 종자의 발아율은 종자품질 기준인 40%를 넘는 것으로 나타났다. 갱신유형별 종자 낙하량은 보잔목작업, 모수작업, 개벌작업 순이었고, 보잔목작업이 종자의 균등한 비산에 유리한 것으로 나타났다. 따라서 일본잎갈나무의 천연갱신을 위한 벌채와 갱신상 조성 시기는 종자가 비산하는 9월 이전이 효과적이고, 보잔목작업이 균일한 종자공급에 유리한 방법인 것으로 판단된다.

• Journal of Construction Engineering and Project Management
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• 제8권4호
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• pp.1-24
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• 2018

In the last decade, the use of Building Information Modeling (BIM) as a new technology has been applied with traditional Computer-aided design implementations in an increasing number of architecture, engineering, and construction projects and applications. Its employment alongside construction management, can be a valuable tool in helping move these activities and projects forward in a more efficient and time-effective manner. The traditional stakeholders, i.e., Owner, A/E and the Contractor are involved in this BIM system that is used in almost every activity of construction projects, such as design, cost estimate and scheduling. This article extracts major features of the application of BIM from perspective of participating BIM components, along with the different phrases, and applies to them a logistic analysis using a fuzzy performance tree, quantifying these phrases to judge the effectiveness of the BIM techniques employed. That is to say, these fuzzy performance trees with fuzzy logic concepts can properly translate the linguistic rating into numeric expressions, and are thus employed in evaluating the influence of BIM applications as a mathematical process. The rotational fuzzy models are used to represent the membership functions of the performance values and their corresponding weights. Illustrations of the use of this fuzzy BIM performance tree are presented in the study for the uninitiated users. The results of these processes are an evaluation of BIM project performance as highly positive. The quantification of the performance ratings for the individual factors is a significant contributor to this assessment, capable of parsing vernacular language into numerical data for a more accurate and precise use in performance analysis. It is hoped that fuzzy performance trees and fuzzy set analysis can be used as a tool for the quality and risk analysis for other construction techniques in the future. Baldwin's rotational models are used to represent the membership functions of the fuzzy sets. Three scenarios are presented using fuzzy MEAN, AND and OR gates from the lowest to intermediate levels of the tree, and fuzzy SUM gate to relate the intermediate level to the top component of the tree, i.e., BIM application final performance. The use of fuzzy MEAN for lower levels and fuzzy SUM gates to reach the top level suggests the most realistic and accurate results. The methodology (fuzzy performance tree) described in this paper is appropriate to implement in today's construction industry when limited objective data is presented and it is heavily relied on experts' subjective judgment.

• 보존과학회지
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• 제38권2호
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• pp.87-95
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• 2022

본 연구에서는 창경궁 명정문 목부재에 대해 수종과 연륜연대분석을 진행하여 재질과 건축역사를 조사하고자 하였다. 명정문 목부재(79점)의 수종은 소나무류 78점, 전나무속 1점으로 확인되었다. 연륜연대분석은 코어링법을 이용하여 시료를 채취하였으며, TSAP 프로그램으로 크로스데이팅을 하였다. 연륜연대분석 결과, 소나무류 목부재 58점에 대한 최외각 연도는 1604년 초봄-1615년 늦가을, 1706년 늦가을-1707년 초봄, 1828년 늦가을-1834년 늦가을로 총 3개의 벌채시기가 확인되었다. 1600년대와 1800년대 벌채시기들은 조선왕족실록, 광해군일기, 창경궁영건도감의궤의 수리기록과 일치한 것을 확인하였으나 1700년대 벌채시기는 기록에서 확인되지 않아 기록에서 확인되지 않은 수리기록을 연륜연대를 통해 확인할 수 있었다.

• 한국산림과학회지
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• 제96권5호
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• pp.602-608
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• 2007

Forest plantations become important strategy not merely for the financial aspect, but for carbon sequestration and ecosystem stability. Forest plantations increase the density of the forest biomass, which reduce the increase in atmospheric carbon dioxide. Biomass density is also a useful variable for comparing structural and functional attributes of forest ecosystems across a wide range of environmental conditions. In this study, carbon sequestration of teak (Tectona grandis Linn. f.) in the individual tree and plantation levels estimation was carried out Site-specific allometric equation for the estimation of teak tree biomass was developed based on the direct measurement of fifteen (15) harvested trees in the Oak-twin Township of the Bago Yoma Region, Myanmar. A regression equation of the diameter at breast height (DBH) and the aboveground biomass (carbon content) was constructed to estimate the carbon storage level of plantations, which averaged 79 ton/ha. The average carbon accumulation in the soil (up to 30 cm in depth) was estimated 38.89 ton/ha, The highest mean annual increment (MAI) of total carbon was found in the 6-yr-old teak plantation (12.10 ton/ha/yr) whereas the lowest MAI was in the 26-yr-old teak plantation (4.31 ton/ha/yr).

• 한국지능시스템학회:학술대회논문집
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• 한국퍼지및지능시스템학회 2003년도 ISIS 2003
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• pp.213-215
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• 2003

Multimedia has to carry data of heterogeous types. Multicast communication techniques can supply the most appropriate infrastructures to such multimedia. Of many multicast protocols, the core based tree (CBT) protocol is the most concentrative studies are conducted on. The CBT places a core router at center of the shared tree and transfers data through the tore router. However, the CBT has two problems due to centralizing all network traffics into a core router. First it can raise bottleneck effect at a core router. Second, it is possible to make an additive processing overhead when core router is distant from receivers. To cope with the problems, this paper proposes an intelligent anycast routing protocol. The anycast routing attempts to distribute the centralized traffic into plural core routers by using a knowledge-based algorithm. The anycast routing estimates the traffic characteristics of multimedia data far each multicast source, and achieves effectively the distributing that places an appropriate core router to process the incoming traffic based on the traffic information in the event that request of receivers are raised. This method prevent the additional overhead to distribute traffic because an individual core router uses the information estimated to multicast sources connected to oneself and the traffic processing statistics shared with other core neuters.

• 한국가스학회지
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• 제14권5호
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• pp.38-44
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• 2010

본 논문은 철도를 통해 운송되는 프로필렌의 사고위험을 정량적으로 분석하였다. 프로필렌의 수송 경로에 따라 사고 시 피해 위험이 높을 것으로 예상되는 지역인 익산역, 순천역, 전주역으로 대상지역을 선정하였다. 프로필렌의 운송 중 일어날 수 있는 사고유형을 고려한 후 ETA(Event Tree Analysis)를 이용하여 사고시나리오 및 발생빈도를 도출하였고, PHAST 6.53(Process Hazard Analysis Software Tool)을 이용하여 사고피해예측 평가 실시하여 주변에 미치는 피해정도를 산정함으로써 개인적.사회적 위험성정도를 제시하였다.