• Title/Summary/Keyword: Reference set

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Bayesian Model Selection in the Unbalanced Random Effect Model

  • Kim, Dal-Ho;Kang, Sang-Gil;Lee, Woo-Dong
    • Journal of the Korean Data and Information Science Society
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    • v.15 no.4
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    • pp.743-752
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    • 2004
  • In this paper, we develop the Bayesian model selection procedure using the reference prior for comparing two nested model such as the independent and intraclass models using the distance or divergence between the two as the basis of comparison. A suitable criterion for this is the power divergence measure as introduced by Cressie and Read(1984). Such a measure includes the Kullback -Liebler divergence measures and the Hellinger divergence measure as special cases. For this problem, the power divergence measure turns out to be a function solely of $\rho$, the intraclass correlation coefficient. Also, this function is convex, and the minimum is attained at $\rho=0$. We use reference prior for $\rho$. Due to the duality between hypothesis tests and set estimation, the hypothesis testing problem can also be solved by solving a corresponding set estimation problem. The present paper develops Bayesian method based on the Kullback-Liebler and Hellinger divergence measures, rejecting $H_0:\rho=0$ when the specified divergence measure exceeds some number d. This number d is so chosen that the resulting credible interval for the divergence measure has specified coverage probability $1-{\alpha}$. The length of such an interval is compared with the equal two-tailed credible interval and the HPD credible interval for $\rho$ with the same coverage probability which can also be inverted into acceptance regions of $H_0:\rho=0$. Example is considered where the HPD interval based on the one-at- a-time reference prior turns out to be the shortest credible interval having the same coverage probability.

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Two-Phase Localization Algorithm in Wireless Sensor Networks (무선 센서 네트워크에서의 2단계 위치 추정 알고리즘)

  • Song Ha-Ju;Kim Sook-Yeon;Kwon Oh-Heum
    • Journal of Korea Multimedia Society
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    • v.9 no.2
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    • pp.172-188
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    • 2006
  • Sensor localization is one of the fundamental problems in wireless sensor networks. Previous localization algorithms can be classified into two categories, the GGB (Global Geometry-Based) approaches and the LGB (Local Geometry-Based). In the GGB approaches, there are a fixed set of reference nodes of which the coordinates are pre-determined. Other nodes determine their positions based on the distances from the fixed reference nodes. In the LGB approaches, meanwhile, the reference node set is not fixed, but grows up dynamically. Most GGB algorithms assume that the nodes are deployed in a convex shape area. They fail if either nodes are in a concave shape area or there are obstacles that block the communications between nodes. Meanwhile, the LGB approach is vulnerable to the errors in the distance estimations. In this paper, we propose new localization algorithms to cope with those two limits. The key technique employed in our algorithms is to determine, in a fully distributed fashion, if a node is in the line-of-sight from another. Based on the technique, we present two localization algorithms, one for anchor-based, another for anchor-free localization, and compare them with the previous algorithms.

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The impact of reorienting cone-beam computed tomographic images in varied head positions on the coordinates of anatomical landmarks

  • Kim, Jae Hun;Jeong, Ho-Gul;Hwang, Jae Joon;Lee, Jung-Hee;Han, Sang-Sun
    • Imaging Science in Dentistry
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    • v.46 no.2
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    • pp.133-139
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    • 2016
  • Purpose: The aim of this study was to compare the coordinates of anatomical landmarks on cone-beam computed tomographic (CBCT) images in varied head positions before and after reorientation using image analysis software. Materials and Methods: CBCT images were taken in a normal position and four varied head positions using a dry skull marked with 3 points where gutta percha was fixed. In each of the five radiographic images, reference points were set, 20 anatomical landmarks were identified, and each set of coordinates was calculated. Coordinates in the images from the normally positioned head were compared with those in the images obtained from varied head positions using statistical methods. Post-reorientation coordinates calculated using a three-dimensional image analysis program were also compared to the reference coordinates. Results: In the original images, statistically significant differences were found between coordinates in the normal-position and varied-position images. However, post-reorientation, no statistically significant differences were found between coordinates in the normal-position and varied-position images. Conclusion: The changes in head position impacted the coordinates of the anatomical landmarks in three-dimensional images. However, reorientation using image analysis software allowed accurate superimposition onto the reference positions.

The Influence of Omni-channel Propensity and Regulatory Focus on Consideration Set Formation (옴니채널 성향, 조절초점과 고려상표군 형성에 관한 연구)

  • HAN, Sang-Seol
    • The Journal of Industrial Distribution & Business
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    • v.10 no.5
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    • pp.49-58
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    • 2019
  • Purpose - Consumer behaviors or decision-making process has been changing recently as the consumer environment, including mobile everyday life, has changed. In view of this changing consumer smart environment, this study aims to investigate structural relation about the influence omni-channel propensity and regulatory focus on consideration set formation. Research design, data, and methodology - In order to proceed with this study, we review previous studies and setting hypotheses. The hypothesis was verified through a survey that was conducted for university students with experience in purchasing in less than three months. With reference to previous studies, operational definition was made for the questionnaire design. From 2018 Nov. to 2019 Feb. Survey was conducted on the panel consumers who purchase item within that period. 315 collected survey data were used to verify hypotheses except the data that had incorrect values. This data were used for SPSS/AMOS for confirm hypothesis which developed by researcher. Results - The results of this study are as follows. First, Consumers were considering a more heterogeneous alternatives if they were more omni-channel propensity in the process of forming consideration set. Second, Consumers were more conscious of the price if they were more omni-channel propensity Third, Consumers were considering a more newness alternatives if they were more omni-channel propensity in the process of forming consideration set. Meanwhile, The results of the study on regulatory focus and consideration set relationships are as follows. Consumers were considering a more heterogeneous alternatives if they were more promotion focus tendency in the process of forming consideration set. Second, Prevention focus tendency were more conscious of the price in the process of considering alternatives. Third, Consumers were considering a more newness alternatives if they were more promotion focus tendency. Conclusions - Depending on the changing consumer environment, the omni-channel propensity was shown to influence the formation of the consideration set. Also, Regulatory focus of consumers significantly influence to formation of consideration set. this study also contributes to the development of the theory as well as the practical approach with understanding consumer decision process on smart(mobile) environment.

Establishing new principles for nutrient reference values (NRVs) for food labeling purposes

  • Yates, Allison A.
    • Nutrition Research and Practice
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    • v.1 no.2
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    • pp.89-93
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    • 2007
  • Many countries such as The Republic of Korea have established their own nutritional standards, collectively termed Nutrient Reference Values (NRVs), and they vary due to the science which was reviewed, the purposes for which they are developed, and issues related to nutrition and food policy in the country. The current effort by the Codex Alimentarius Committee on Nutrition and Foods for Special Dietary Uses (CNFSDU) to update the NRVs that were established following the Helsinki Consultation in 1988 represents an opportunity to develop a set of reference values reflecting current scientific information to be used or adapted by many countries. This paper will focus on possible approaches to selecting or developing reference values which would serve the intended purpose for nutrition labeling to the greatest extent possible. Within the United States, the Food and Drug Administration (U.S. FDA) is currently reviewing regulations on nutrition labeling to better address current health issues, and is expected to enter into a process in the next few months to begin to explore how best to update nutrient Daily Values (DVs), most of which are still based on the Recommended Dietary Allowances (RDAs) of the Food and Nutrition Board, U.S. National Academy of Sciences, last reviewed and revised in 1968. In this presentation, I review the current purposes in the U.S. for nutrition labeling as identified in the 1938 Food, Drug, and Cosmetic Act as amended, the scientific basis for current nutrition labeling regulations in the United States, and the recommendations made by the recent Committee on Use of Dietary Reference Intakes in Nutrition Labeling of the Institute of Medicine (2003) regarding how to use the DRIs in developing new DVs to be used on the label in the United States and Canada. Based on these reviews, I then provide examples of the issues that arise in comparing one approach to another. Much of the discussion focuses on the appropriate role of nutrient labeling within the Nutrition Facts panel, one of the three major public nutrition education tools in the United States (along with MyPyramid and Dietary Guidelines for Americans).

Resolving the Runtime Class Reference Problem of the Type Object Design Pattern by Type Object Class (Type Object Class에 의한 Type Object 디자인 패턴의 런타임 클래스 참조문제의 해결)

  • Kim, Yun-Ho
    • Journal of the Korea Institute of Information and Communication Engineering
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    • v.11 no.3
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    • pp.500-506
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    • 2007
  • The Type Object Design Pattern is proposed to provide a solution on the situation in the case that one class has too many subclasses or the number of subclasses are undefined. Although this pattern has many advantages in terms of applicability and dynamic object behavior, it has a weak point in runtime pattern operation that it has to build and maintain a class reference mechanism in runtime to reference the class (de facto 'object') of instances. To solve that problem, this paper addresses the solution of the runtime class reference problem of Type Object Pattern. it defines a new class of Type Object Class (TOC) from Type Class and Object Class in Type Object pattern and presents the methods of creating, compiling, and memory-loading the TOC. It depends on built-in class reference mechanism of object-oriented programming language, and is not necessary to fit with the additional mechanism. Consequently, we need not to set up the additional class reference mechanism and system performance is enhanced due to it.

Automatic Generation of Code-clone Reference Corpus (코드클론 표본 집합체 자동 생성기)

  • Lee, Hyo-Sub;Doh, Kyung-Goo
    • Journal of Software Assessment and Valuation
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    • v.7 no.1
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    • pp.29-39
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    • 2011
  • To evaluate the quality of clone detection tools, we should know how many clones the tool misses. Hence we need to have the standard code-clone reference corpus for a carefully chosen set of sample source codes. The reference corpus available so far has been built by manually collecting clones from the results of various existing tools. This paper presents a tree-pattern-based clone detection tool that can be used for automatic generation of reference corpus. Our tool is compared with CloneDR for precision and Bellon's reference corpus for recall. Our tool finds no false positives and 2 to 3 times more clones than CloneDR. Compared to Bellon's reference corpus, our tools shows the 93%-to-100% recall rate and detects far more clones.

A Study on Luminance Contrast Criteria for Tactile Walking Surface Indicators (시각장애인 점자블록의 휘도대비 기준에 대한 연구)

  • Shin, Dong-Hong;Park, Kwang-Jae;Kim, Sang-Woon
    • Journal of The Korea Institute of Healthcare Architecture
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    • v.22 no.1
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    • pp.7-15
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    • 2016
  • Purpose: There are the number of color tactile walking surface indicators installed in Korea, because of indefinite regulation in blind and vision-impaired persons' tactile walking surface indicators. In case of yellow tactile walking surface indicators, it shows a deviation severe color. In this study, the researchers suggested color and brightness reference for helping blind and vision-impaired persons' walking through analyzing the color references of tactile walking surface indicators and the color luminance between tactile walking surface indicators and sidewalk currently used. Method: Reasonable luminance contrast criteria is suggested by examining ways of improving the recognition and recognition of objects according to color contrast visually impaired through literature review and analyzing standards of tactile walking surface indicators and the Europe, Japan and Australia of color and luminance contrast criteria. And by examining the color of the tactile walking surface indicators reported in Korea currently used to derive the problem presented by the luminance contrast in the reference and comparison. Finally, the visually impaired tactile walking surface indicators is set for color selection criteria for the recognition rate improves. Results: In order to improve the recognition rate to be tactile walking surface indicators of the contrast of the visually impaired and the environment than the color of the tactile walking surface indicators itself to secure always a certain level or more of brightness contrast values in the set of the color of the tactile walking surface indicators so important. Implication: In order to set the blind tactile walking surface indicators color recognition based on the verification of the real pedestrian based on the results presented in this paper it is required. It is to be understood as an element of the barrier free configuration for securing the walking pedestrian safety.

The Use of Reinforcement Learning and The Reference Page Selection Method to improve Web Spidering Performance (웹 탐색 성능 향상을 위한 강화학습 이용과 기준 페이지 선택 기법)

  • 이기철;이선애
    • Journal of the Korea Computer Industry Society
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    • v.3 no.3
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    • pp.331-340
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    • 2002
  • The web world is getting so huge and untractable that without an intelligent information extractor we would get more and more helpless. Conventional web spidering techniques for general purpose search engine may be too slow for the specific search engines, which concentrate only on specific areas or keywords. In this paper a new model for improving web spidering capabilities is suggested and experimented. How to select adequate reference web pages from the initial web Page set relevant to a given specific area (or keywords) can be very important to reduce the spidering speed. Our reference web page selection method DOPS dynamically and orthogonally selects web pages, and it can also decide the appropriate number of reference pages, using a newly defined measure. Even for a very specific area, this method worked comparably well almost at the level of experts. If we consider that experts cannot work on a huge initial page set, and they still have difficulty in deciding the optimal number of the reference web pages, this method seems to be very promising. We also applied reinforcement learning to web environment, and DOPS-based reinforcement learning experiments shows that our method works quite favorably in terms of both the number of hyper links and time.

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Multiple-Shot Person Re-identification by Features Learned from Third-party Image Sets

  • Zhao, Yanna;Wang, Lei;Zhao, Xu;Liu, Yuncai
    • KSII Transactions on Internet and Information Systems (TIIS)
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    • v.9 no.2
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    • pp.775-792
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    • 2015
  • Person re-identification is an important and challenging task in computer vision with numerous real world applications. Despite significant progress has been made in the past few years, person re-identification remains an unsolved problem. This paper presents a novel appearance-based approach to person re-identification. The approach exploits region covariance matrix and color histograms to capture the statistical properties and chromatic information of each object. Robustness against low resolution, viewpoint changes and pose variations is achieved by a novel signature, that is, the combination of Log Covariance Matrix feature and HSV histogram (LCMH). In order to further improve re-identification performance, third-party image sets are utilized as a common reference to sufficiently represent any image set with the same type. Distinctive and reliable features for a given image set are extracted through decision boundary between the specific set and a third-party image set supervised by max-margin criteria. This method enables the usage of an existing dataset to represent new image data without time-consuming data collection and annotation. Comparisons with state-of-the-art methods carried out on benchmark datasets demonstrate promising performance of our method.