• Title/Summary/Keyword: Bayesian 분석

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Examining Impact of Weather Factors on Apple Yield (사과생산량에 영향을 미치는 기상요인 분석)

  • Kim, Mi Ri;Kim, Seung Gyu
    • Korean Journal of Agricultural and Forest Meteorology
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    • v.16 no.4
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    • pp.274-284
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    • 2014
  • Crops and varieties are mostly affected by temperature, the amount of precipitation, and duration of sunshine. This study aims to identify the weather factors that directly influence to apple yield among the series of daily measured weather variables during growing seasons. In order to identify them, 1) a priori natural scientific knowledge with respect to the growth stage of apples and 2) pure statistical approaches to minimize bias due to the subject selection of variables are considered. Each result estimated by the Panel regression using fixed/random effect models is evaluated through suitability (i.e., Akaike information criterion and Bayesian information criterion) and predictability (i.e., mean absolute error, root mean square error, mean absolute percentage). The Panel data of apple yield and weather factors are collected from fifteen major producing areas of apples from 2006 to 2013 in Korea for the case study. The result shows that variable selection using factor analysis, which is one of the statistical approaches applied in the analysis, increases predictability and suitability most. It may imply that all the weather factors are important to predict apple yield if statistical problems, such as multicollinearity and lower degree of freedom due to too many explanatory variables used in the regression, can be controlled effectively. This may be because whole growth stages, such as germination, florescence, fruit setting, fatting, ripening, coloring, and harvesting, are affected by weather.

Demand analysis on new Mobile Telecommunication Terminal using Conjoint analysis and Mixed logit (컨조인트 분석과 혼합 로짓 모형을 이용한 차세대 무선 이동 통신 단말기의 수요 분석)

  • 김연배;이정동;고대영
    • Proceedings of the Korea Technology Innovation Society Conference
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    • 2003.11a
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    • pp.67-85
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    • 2003
  • 본 논문에서는 최근 통신 산업에서 중요한 쟁점으로 떠오르고 있는 단말기 무선이동 통신 단말기의 발전 방향을 소비자 선호에 기반하여 살펴보았다. 소비자 선호 정보를 얻기 위하여 컨조인트(conjoint) 분석 방법이 사용되었다. 컨조인트 방법은 가상의 대안들에 대한 응답자의 진술 선호에 기반을 두기 때문에 미래의 무선 이동통신 단말기에 대해 분석하는데 적합한 방법이다. 컨조인트 방법을 위한 설문은 대한민국 서울에서 445 명의 성인남녀를 대상으로 행해졌다. 소비자의 이질적인 선호를 알기 위해 혼합 로짓(mixed legit) 모형을 사용하였다. 추정은 최근 새로운 시뮬레이션 기법으로 떠오르고 있는 베이지안(Bayesian) 방법을 이용하였다. 선호의 분포 가정으로 기존의 일관적인 정규 분포 가정과 달리 가격 계수를 위하여 로그 정규(lognormal) 분포, 하이퀄리티 인터넷 특성과 PC 프로그램 호환 가능 여부의 계수들에 대해서 잘린 정규(censored normal) 분포를 가정 하였다. 추정 결과 무선 이동 통신 단말기의 각 속성들에 대한 응답자들간 선호가 크게 차이 나는 것을 알 수 있었다. 화면 크기의 경우에는 대부분의 소비자들이 현재 일반적인 핸드폰보다는 큰 화면을 선호한다는 것과 휴대성을 상당히 고려한다는 것을 간접적으로 알 수 있었다. 또한, 소비자들이 무선 이동 통신 단말기가 휴대 인터넷과 PC 프로그램 호환이 가능한지 여부에는 대부분 무관심하다는 것을 알 수 있었다. 본 논문의 결과는 차세대 무선 이동 통신 단말기의 속성 조합 시 고려해야 할 점과 휴대 인터넷 서비스의 방향에 대해 시사점을 줄 수 있을 것이다.각 73.44±0.87%, 72.88±0.25%의 함량이였다. 운동사육시간이 길어질수록 운동사육구에서는 수분함량이 운동5일째에는 73.56±0.22%였으며, 운동 20일에는 75.88±0.94%로 초기수분함량보다는 3%정도 증가하였다. 반면, 비운동사육구에서는 큰 변화를 나타내고 있지 않았다(p<0.05). 운동과 비운동시킨 참돔의 지질 함량의 변화는 운동시킨 참돔은 운동으로 인한 에너지 소비로 인하여 함량이 유의적으로 감소했으며(r=-0.35), 비운동사육구에서는 절식으로 인하여 지질함량이 감소하였다(r=-0.38). 파괴강도와 가장 밀접한 영향을 가지는 콜라겐은 운동과 비운동 모두 사육기간동안 큰 변화는 보이지 않았다. 초기의 파괴강도값은 1.45±0.02kg(운동사육구), 1.36±0.18kg(비운동사육구)이였으며 사육기간동안 운동사육구는 파괴강도값이 증가한 반면, 비운동수조에서는 참돔의 파괴강도는 사육기간동안 큰 유의차가 없었다. 각 성분간의 상관도를 살펴보면, 수분함량과 파괴강도는 상관성을 가졌으며, 지질함량과 파괴강도도 같은 경향은 나타내었다. 운동기간동안의 파괴강도와 콜라겐 사이에는 상관성의 거의 없었다. 이는 운동기간에 따른 파괴강도의 증가가 콜라겐의 함량의 증가보다는 지질함량의 감소와 수분함량의 증가와 같은 성분과의 상관성이 크다고 판단된다. 다음으로는, 운동횟수에 의한 영향으로써 운동시간을 1일 6시간으로 설정하여, 운동횟수를 결정하기 위하여 오전, 오후에 각 3시간씩 운동시키는 방법과 오전부터 6시간동안 운동시키는 두 방법을 이용하여 품질을 비교하였다. 각 조건에 따라 운동시킨 참돔의 수분함량을 나타낸 것으로, 2회(오전

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Assessing the public preference and acceptance for renewable energy participation initiatives - focusing on photovoltaic power (재생에너지 사업 참여에 대한 국민 선호와 수용성 분석 - 태양광 발전을 중심으로)

  • Ham, AeJung;Kang, SeungJin
    • Journal of Energy Engineering
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    • v.27 no.4
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    • pp.36-49
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    • 2018
  • This study analyzed the public preference and acceptance regarding renewable energy projects through Choice Based Conjoint Analysis. The results show that the surveyed respondents consider the leading authority of the projects, as the most important factor when considering participating in renewable energy initiatives. Following this, the mode of participation and profit distribution and the power plant location are also viewed as important, whereas participation through decision making regarding the projects was less important. Also when participating in renewable energy projects, respondents tend to prefer to financially participating through loans or owning shares rather than volunteering support for the business such as sharing information, stating one's views, or providing cooperation and coordination. Therefore, the focus is on distributional justice, such as financial investment and profit distribution, rather than procedural justice, for instance decision making. When analyzing the part-worths utilities for the participation attribute, the respondents most preferred to receiving dividends based on earnings by owning shares with the local government in charge of the entire projects. As a consequence, the results suggest that it is important to have local government get involved and have trust-worthy governing systems in place for the initiation of the public participating-renewable energy projects.

Genetic Differentiation between Up- and Downstream Populations of Tribolodon hakonensis (Pieces: Cyprinidae) (삼척오십천 상.하류에 분포하는 황어, Tribolodon hakonensis (잉어과) 집단의 유전적 분화)

  • Lee, Sihn-Ae;Lee, Wan-Ok;Suk, Ho-Young
    • Korean Journal of Environment and Ecology
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    • v.26 no.4
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    • pp.475-483
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    • 2012
  • Tribolodon hakonensis(Cypriniformes; Leuciscinae) is anadromous; they are born in freshwater, migrate back to the ocean, then return to their home stream for spawning from mid-March to early-June. Here, five microsatellites were used to assess the level of gene flow among T. hakonensis populations from the Samcheok-Oship Stream, South Korea. The frequencies of dominant alleles across several loci differed between down-and upstream populations divided by several weirs, and pairwise multilocus $F_{ST}$ estimate was significantly high(0.083). However, there were no signs of any loss of genetic variation in the upstream population. Assignment tests of individuals in admixture model(K=2) to a set of baseline samples showed fairly correct assignment to each cluster; all of upstream individuals sere included in the first cluster, while the majority of downstream individuals(65%) comprise the second cluster. These results indicate reduced gene flow between up- and downstream populations but allowing passive downstream drift. It is likely that man-made structures might at least partially be a factor for creating and consolidating the current distribution patterns of genetic variation among T. hakonensis populations in the Samcheok-Oship Stream. This information will assist governing agencies in making informed decisions regarding conservation of anadromous fishes in Korean drainage systems.

Safety Impacts of Red Light Enforcement on Signalized Intersections (교차로 신호위반 단속카메라 설치가 차량사고에 미치는 영향)

  • Lee, Sang Hyuk;Lee, Yong Doo;Do, Myung Sik
    • Journal of Korean Society of Transportation
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    • v.30 no.6
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    • pp.93-102
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    • 2012
  • The frequency and severity of traffic accidents related to signalized intersections in urban areas have been more serious than those in both arterial segments and crosswalks. Especially, traffic accidents involved with injuries and fatalities have caused by traffic signal violations within intersections. Therefore, many countries including Korea have installed the red light enforcement camera (RLE) to reduce traffic accidents associated with the traffic signal violation. Meanwhile, many methodologies have been studied in terms of safety impacts estimation of red light enforcement, which, however, cannot be easy to conduct. In this study, safety impacts was estimated for intersections of Chicago downtown area using SPF models and EB approach. As a result, for all crash types and target traffic accident types such as "angle", "rear end", "sideswipe in the same and other directions", "turn", and "head on", fatal crashes were reduced by 26% and 38%. However, RLE may increase property-demage-only-crashes by 3.23% and 1.16%, respectively.

Modeling Consumers' WOM (Word-Of-Mouth) Behavior with Subjective Evaluation and Objective Information on High-tech Products (하이테크 제품에 대한 소비자의 주관적 평가와 객관적 정보 구전 활동에 대한 연구)

  • Chung, Jaihak
    • Asia Marketing Journal
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    • v.11 no.1
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    • pp.73-92
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    • 2009
  • Consumers influence other consumers' brand choice behavior by delivering a variety of objective or subjective information on a particular product, which is called WOM (Word-Of-Mouth) activities. For WOM activities, WOM senders should choose messages to deliver to other consumers. We classify the contents of the messages a consumer chooses for WOM delivery into two categories: Subjective (positive or negative) evaluation and objective information on products. In our study, we regard WOM senders' activities as a choice behavior and introduce a choice model to study the relationship between the choice of different WOM information (WOM with positive or negative subjective evaluation and WOM with objective information) and its influencing factors (information sources and consumer characteristics) by developing two bivariate Probit models. In order to consider the mediating effects of WOM senders' product involvement, product attitude, and their characteristics (gender and age), we develop three second-level models for the propagation of positive evaluations, of negative evaluations, and of objective information on products in an hierarchical Bayesian modeling framework. Our empirical results show that WOM senders' information choice behavior differs according to the types of information sources. The effects of information sources on WOM activities differ according to the types of WOM messages (subjective evaluation (positive or negative) and objective information). Therefore, our study concludes that WOM activities can be partially managed with effective communication plans influencing on consumers' WOM message choice behavior. The empirical results provide some guidelines for consumers' propagation of information on products companies want.

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Rule Generation and Approximate Inference Algorithms for Efficient Information Retrieval within a Fuzzy Knowledge Base (퍼지지식베이스에서의 효율적인 정보검색을 위한 규칙생성 및 근사추론 알고리듬 설계)

  • Kim Hyung-Soo
    • Journal of Digital Contents Society
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    • v.2 no.2
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    • pp.103-115
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    • 2001
  • This paper proposes the two algorithms which generate a minimal decision rule and approximate inference operation, adapted the rough set and the factor space theory in fuzzy knowledge base. The generation of the minimal decision rule is executed by the data classification technique and reduct applying the correlation analysis and the Bayesian theorem related attribute factors. To retrieve the specific object, this paper proposes the approximate inference method defining the membership function and the combination operation of t-norm in the minimal knowledge base composed of decision rule. We compare the suggested algorithms with the other retrieval theories such as possibility theory, factor space theory, Max-Min, Max-product and Max-average composition operations through the simulation generating the object numbers and the attribute values randomly as the memory size grows. With the result of the comparison, we prove that the suggested algorithm technique is faster than the previous ones to retrieve the object in access time.

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Effective Eye Detection for Face Recognition to Protect Medical Information (의료정보 보호를 위해 얼굴인식에 필요한 효과적인 시선 검출)

  • Kim, Suk-Il;Seok, Gyeong-Hyu
    • The Journal of the Korea institute of electronic communication sciences
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    • v.12 no.5
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    • pp.923-932
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    • 2017
  • In this paper, we propose a GRNN(: Generalized Regression Neural Network) algorithms for new eyes and face recognition identification system to solve the points that need corrective action in accordance with the existing problems of facial movements gaze upon it difficult to identify the user and. Using a Kalman filter structural information elements of a face feature to determine the authenticity of the face was estimated future location using the location information of the current head and the treatment time is relatively fast horizontal and vertical elements of the face using a histogram analysis the detected. And the light obtained by configuring the infrared illuminator pupil effects in real-time detection of the pupil, the pupil tracking was to extract the text print vector. The abstract is to be in fully-justified italicized text as it is here, below the author information.

Note Tracking and Localization Algorithm for Interactive Rhythm-based Music Player (리듬기반 인터액티브 음악 플레이어를 위한 음표 위치 추적 알고리즘)

  • Kim, Jae-Hong;Park, Jae-Sung;Lee, Jun-Seong;Cha, Dong-Hoon;Kim, Joung-Hyun
    • 한국HCI학회:학술대회논문집
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    • 2009.02a
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    • pp.482-486
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    • 2009
  • Conventional music players offer simple replay and one way entertainment. The paper presents an algorithm to extract, within a digitally recorded music file, the temporal information of a sequence of target notes (i.e. melody). We assume to have the score (e.g. MIDI or printed score), and using this information, it becomes possible to first sequentially predict the probable location of the target notes. However, recorded music is hardly performed according to the score, especially temporally. Thus, additional analysis is carried out to hone in on the exact location of the target note from the initially predicted location. This prediction and correction process is repeated to find one note after another. This allows us to develop an interactive music player that is enacted by rhythmic interaction, and induce a new user experience, i.e. as if one is playing the music oneself.

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Analyzing Influence of Outlier Elimination on Accuracy of Software Effort Estimation (소프트웨어 공수 예측의 정확성에 대한 이상치 제거의 영향 분석)

  • Seo, Yeong-Seok;Yoon, Kyung-A;Bae, Doo-Hwan
    • Journal of KIISE:Software and Applications
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    • v.35 no.10
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    • pp.589-599
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    • 2008
  • Accurate software effort estimation has always been a challenge for the software industrial and academic software engineering communities. Many studies have focused on effort estimation methods to improve the estimation accuracy of software effort. Although data quality is one of important factors for accurate effort estimation, most of the work has not considered it. In this paper, we investigate the influence of outlier elimination on the accuracy of software effort estimation through empirical studies applying two outlier elimination methods(Least trimmed square regression and K-means clustering) and three effort estimation methods(Least squares regression, Neural network and Bayesian network) associatively. The empirical studies are performed using two industry data sets(the ISBSG Release 9 and the Bank data set which consists of the project data collected from a bank in Korea) with or without outlier elimination.