• 제목/요약/키워드: Ranking Data

검색결과 656건 처리시간 0.033초

Applying a modified AUC to gene ranking

  • Yu, Wenbao;Chang, Yuan-Chin Ivan;Park, Eunsik
    • Communications for Statistical Applications and Methods
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    • 제25권3호
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    • pp.307-319
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    • 2018
  • High-throughput technologies enable the simultaneous evaluation of thousands of genes that could discriminate different subclasses of complex diseases. Ranking genes according to differential expression is an important screening step for follow-up analysis. Many statistical measures have been proposed for this purpose. A good ranked list should provide a stable rank (at least for top-ranked gene), and the top ranked genes should have a high power in differentiating different disease status. However, there is a lack of emphasis in the literature on ranking genes based on these two criteria simultaneously. To achieve the above two criteria simultaneously, we proposed to apply a previously reported metric, the modified area under the receiver operating characteristic cure, to gene ranking. The proposed ranking method is found to be promising in leading to a stable ranking list and good prediction performances of top ranked genes. The findings are illustrated through studies on both synthesized data and real microarray gene expression data. The proposed method is recommended for ranking genes or other biomarkers for high-dimensional omics studies.

랭킹 SVM과 RDBMS의 밀결합 통합 (Tightly Coupled Integration of Ranking SVM and RDBMS)

  • 송재환;오진오;양은석;유환조
    • 한국정보과학회논문지:데이타베이스
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    • 제36권4호
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    • pp.247-253
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    • 2009
  • 지난 십 년간 랭킹은 데이터 마이닝 분야의 활발한 연구분야였다. 그러나 랭킹은 다른 데이터 마이닝 기법들과 비슷하게 RDBMS와는 독립적으로 개발되었고, 그로 인해 기존에 널리 사용되고 있는 RDBMS들과의 연동성이 떨어진다는 단점이 존재하게 되었다. 다른 데이터 마이닝 기법들은 소결합이나 밀결합 접근법을 이용하여 RDBMS와 연동하기 위한 연구가 활발하게 진행되어 왔고, 그 결과 실제로 사용 가능한 응용시스템들이 나오게 되었다. 그러나 랭킹에서는 이와 같은 노력들이 잘 이루어지지 않고 있다. 본 논문에서는 랭킹 작업을 RDBMS에 연동하여 효율적으로 수행하기 위하여 MySQL에 Ranking SVM을 통합하는 작업을 진행하였다. 밀결합 접근법을 기반으로 하는 우리의 구현은 MySQL에 랭킹을 위한 새로운 SQL 명령어를 추가하였고 랭킹 작업의 효율성을 확인하기 위해서 소결합 접근법을 기반으로 하는 Ranking SVM과 성능을 비교 평가하여 훈련단계에서 $10{\sim}40%$, 예측단계에서 평균 60%의 성능향상을 확인할 수 있었다.

폭소노미 사이트를 위한 랭킹 프레임워크 설계: 시맨틱 그래프기반 접근 (A Folksonomy Ranking Framework: A Semantic Graph-based Approach)

  • 박현정;노상규
    • Asia pacific journal of information systems
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    • 제21권2호
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    • pp.89-116
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    • 2011
  • In collaborative tagging systems such as Delicious.com and Flickr.com, users assign keywords or tags to their uploaded resources, such as bookmarks and pictures, for their future use or sharing purposes. The collection of resources and tags generated by a user is called a personomy, and the collection of all personomies constitutes the folksonomy. The most significant need of the folksonomy users Is to efficiently find useful resources or experts on specific topics. An excellent ranking algorithm would assign higher ranking to more useful resources or experts. What resources are considered useful In a folksonomic system? Does a standard superior to frequency or freshness exist? The resource recommended by more users with mere expertise should be worthy of attention. This ranking paradigm can be implemented through a graph-based ranking algorithm. Two well-known representatives of such a paradigm are Page Rank by Google and HITS(Hypertext Induced Topic Selection) by Kleinberg. Both Page Rank and HITS assign a higher evaluation score to pages linked to more higher-scored pages. HITS differs from PageRank in that it utilizes two kinds of scores: authority and hub scores. The ranking objects of these pages are limited to Web pages, whereas the ranking objects of a folksonomic system are somewhat heterogeneous(i.e., users, resources, and tags). Therefore, uniform application of the voting notion of PageRank and HITS based on the links to a folksonomy would be unreasonable, In a folksonomic system, each link corresponding to a property can have an opposite direction, depending on whether the property is an active or a passive voice. The current research stems from the Idea that a graph-based ranking algorithm could be applied to the folksonomic system using the concept of mutual Interactions between entitles, rather than the voting notion of PageRank or HITS. The concept of mutual interactions, proposed for ranking the Semantic Web resources, enables the calculation of importance scores of various resources unaffected by link directions. The weights of a property representing the mutual interaction between classes are assigned depending on the relative significance of the property to the resource importance of each class. This class-oriented approach is based on the fact that, in the Semantic Web, there are many heterogeneous classes; thus, applying a different appraisal standard for each class is more reasonable. This is similar to the evaluation method of humans, where different items are assigned specific weights, which are then summed up to determine the weighted average. We can check for missing properties more easily with this approach than with other predicate-oriented approaches. A user of a tagging system usually assigns more than one tags to the same resource, and there can be more than one tags with the same subjectivity and objectivity. In the case that many users assign similar tags to the same resource, grading the users differently depending on the assignment order becomes necessary. This idea comes from the studies in psychology wherein expertise involves the ability to select the most relevant information for achieving a goal. An expert should be someone who not only has a large collection of documents annotated with a particular tag, but also tends to add documents of high quality to his/her collections. Such documents are identified by the number, as well as the expertise, of users who have the same documents in their collections. In other words, there is a relationship of mutual reinforcement between the expertise of a user and the quality of a document. In addition, there is a need to rank entities related more closely to a certain entity. Considering the property of social media that ensures the popularity of a topic is temporary, recent data should have more weight than old data. We propose a comprehensive folksonomy ranking framework in which all these considerations are dealt with and that can be easily customized to each folksonomy site for ranking purposes. To examine the validity of our ranking algorithm and show the mechanism of adjusting property, time, and expertise weights, we first use a dataset designed for analyzing the effect of each ranking factor independently. We then show the ranking results of a real folksonomy site, with the ranking factors combined. Because the ground truth of a given dataset is not known when it comes to ranking, we inject simulated data whose ranking results can be predicted into the real dataset and compare the ranking results of our algorithm with that of a previous HITS-based algorithm. Our semantic ranking algorithm based on the concept of mutual interaction seems to be preferable to the HITS-based algorithm as a flexible folksonomy ranking framework. Some concrete points of difference are as follows. First, with the time concept applied to the property weights, our algorithm shows superior performance in lowering the scores of older data and raising the scores of newer data. Second, applying the time concept to the expertise weights, as well as to the property weights, our algorithm controls the conflicting influence of expertise weights and enhances overall consistency of time-valued ranking. The expertise weights of the previous study can act as an obstacle to the time-valued ranking because the number of followers increases as time goes on. Third, many new properties and classes can be included in our framework. The previous HITS-based algorithm, based on the voting notion, loses ground in the situation where the domain consists of more than two classes, or where other important properties, such as "sent through twitter" or "registered as a friend," are added to the domain. Forth, there is a big difference in the calculation time and memory use between the two kinds of algorithms. While the matrix multiplication of two matrices, has to be executed twice for the previous HITS-based algorithm, this is unnecessary with our algorithm. In our ranking framework, various folksonomy ranking policies can be expressed with the ranking factors combined and our approach can work, even if the folksonomy site is not implemented with Semantic Web languages. Above all, the time weight proposed in this paper will be applicable to various domains, including social media, where time value is considered important.

공공의료원의 효율성과 수익성 평가 지표의 대체 가능성 검토 (Review on Interchangeability between Efficiency Ranking and Profitability Ranking in Public Medical Centers)

  • 김상미;이해종;이동원
    • 한국병원경영학회지
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    • 제21권1호
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    • pp.43-50
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    • 2016
  • The public medical centers are required to make efficient and profitable operation. The efficiency is usually measured by DEA(data envelopment analysis), and profitability is measured by medical income rate. But DEA is measured by relative, not absolute value. So, profitability rate is used alternatively for DEA. This study want to analyze the interchangeability between DEA ranking and medical income rate ranking among public medical centers. The return on total assets is same ranking with DEA on bed number, employee number and total asset, but 60-70% relationship with DEA on bed number and employee number, as input resources. The operating margin is similar ranking with DEA on bed number and employee number, but 50-60% relationship with DEA on bed number, employee number and total asset, as input resources.

온라인리뷰의 랭킹모델링을 위한 양과 질의 인과모형 분석 (Causal model analysis between quantity and quality for deriving ranking model of Online reviews)

  • 이창용;김근형
    • 한국정보시스템학회지:정보시스템연구
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    • 제28권1호
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    • pp.1-16
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    • 2019
  • Purpose The purpose of this study is to analyze causal relationship between quantity and quality for deriving ranking model of Online reviews. Thus, we propose implications for deriving the ranking model for retrieving Online reviews more effectively. Design/methodology/approach We collected Online review from Tripadvisor web sites which might be a kind of world-famous tourism web sites. We transformed the natural text reviews to quantified data which consists of quantified positive opinions, quantified negative opinions, quantified modification opinions, reviews lengths and grade scores by using opinion mining technologies in R package. We executed corelation and regression analysis about the data. Findings According to the empirical analysis result, this study confirmed that the review length influenced positive opinion, negative opinion and modification opinion. We also confirmed that negative opinion and modification opinion influenced the grade score.

조사연구에서 순위절차를 이용한 항목순위결정에 관한 연구 (Ordering Items from Ranking Procedures in Survey Research)

  • 허순영;장덕준;신재경
    • 한국조사연구학회지:조사연구
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    • 제9권2호
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    • pp.29-49
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    • 2008
  • 설문조사에서 어떤 주제와 관련된 여러 항목들을 제시하고 응답자들의 가치 기준에 따라 응답하게 한 후, 그 응답들을 종합하여 항목들 간의 순위를 결정할 목적으로 설문을 제시하는 경우가 많이 있다. 이 경우 가장 일반적으로 사용하는 것이 순위척도(ranking scales)와 평정 척도(rating scales)이다. 순위척도 중에서도 주어진 항목들 중 가장 중요한 것을 하나 이상 선택하게 하는 축소순위척도(reduced ranking scales)가 많이 사용된다. 그러나 실제로 항목간의 순위를 결정하는 과정에서 순위응답을 고려하는 경우는 극히 드물다. 본 연구는 순위절차(ranking procedures)에 의한 설문응답에서, 순위응답을 고려하여 항목순위를 결정하는 방법들을 고찰하였다. 또 몇 가지 사례를 통해 그 방법들을 비교 분석하였으며, 이 과정에서 순위척도를 조건부평정척도로 간주하였다. 축소순위척도에 의한 항목순위결정의 경우, 1순위와 2순위 그리고 3순위에 각각 2와 1 그리고 0의 값을 부여함으로써 1순위의 응답비율을 희석하지 않으면서 2순위 응답비율을 적절히 수용하여 보다 합리적인 항목순위를 결정할 수 있음을 확인할 수 있었다.

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Revisiting the Bradley-Terry model and its application to information retrieval

  • Jeon, Jong-June;Kim, Yongdai
    • Journal of the Korean Data and Information Science Society
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    • 제24권5호
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    • pp.1089-1099
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    • 2013
  • The Bradley-Terry model is widely used for analysis of pairwise preference data. We explain that the popularity of Bradley-Terry model is gained due to not only easy computation but also some nice asymptotic properties when the model is misspecified. For information retrieval required to analyze big ranking data, we propose to use a pseudo likelihood based on the Bradley-Terry model even when the true model is different from the Bradley-Terry model. We justify using the Bradley-Terry model by proving that the estimated ranking based on the proposed pseudo likelihood is consistent when the true model belongs to the class of Thurstone models, which is much bigger than the Bradley-Terry model.

Video Ranking Model: a Data-Mining Solution with the Understood User Engagement

  • Chen, Yongyu;Chen, Jianxin;Zhou, Liang;Yan, Ying;Huang, Ruochen;Zhang, Wei
    • Journal of Multimedia Information System
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    • 제1권1호
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    • pp.67-75
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    • 2014
  • Nowadays as video services grow rapidly, it is important for the service providers to provide customized services. Video ranking plays a key role for the service providers to attract the subscribers. In this paper we propose a weekly video ranking mechanism based on the quantified user engagement. The traditional QoE ranking mechanism is relatively subjective and usually is accomplished by grading, while QoS is relatively objective and is accomplished by analyzing the quality metrics. The goal of this paper is to establish a ranking mechanism which combines the both advantages of QoS and QoE according to the third-party data collection platform. We use data mining method to classify and analyze the collected data. In order to apply into the actual situation, we first group the videos and then use the regression tree and the decision tree (CART) to narrow down the number of them to a reasonable scale. After that we introduce the analytic hierarchy process (AHP) model and use Elo rating system to improve the fairness of our system. Questionnaire results verify that the proposed solution not only simplifies the computation but also increases the credibility of the system.

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An Improved Approach to Ranking Web Documents

  • Gupta, Pooja;Singh, Sandeep K.;Yadav, Divakar;Sharma, A.K.
    • Journal of Information Processing Systems
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    • 제9권2호
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    • pp.217-236
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    • 2013
  • Ranking thousands of web documents so that they are matched in response to a user query is really a challenging task. For this purpose, search engines use different ranking mechanisms on apparently related resultant web documents to decide the order in which documents should be displayed. Existing ranking mechanisms decide on the order of a web page based on the amount and popularity of the links pointed to and emerging from it. Sometime search engines result in placing less relevant documents in the top positions in response to a user query. There is a strong need to improve the ranking strategy. In this paper, a novel ranking mechanism is being proposed to rank the web documents that consider both the HTML structure of a page and the contextual senses of keywords that are present within it and its back-links. The approach has been tested on data sets of URLs and on their back-links in relation to different topics. The experimental result shows that the overall search results, in response to user queries, are improved. The ordering of the links that have been obtained is compared with the ordering that has been done by using the page rank score. The results obtained thereafter shows that the proposed mechanism contextually puts more related web pages in the top order, as compared to the page rank score.

스크랩 기능을 지원하는 블로그 공간에서 포스트 랭킹 방안: 알고리즘 및 성능 평가 (Post Ranking in a Blogosphere with a Scrap Function: Algorithms and Performance Evaluation)

  • 황원석;도영주;김상욱
    • 정보처리학회논문지D
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    • 제18D권2호
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    • pp.101-110
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    • 2011
  • 블로그의 사용량이 증가함에 따라 다수의 포스트들이 블로고스피어 내에 작성되고 있으며, 이는 검색에서 웹 서퍼가 양질의 포스트를 찾기 어렵게 하는 문제를 가져왔다. 이로 인하여 포스트 검색에서 랭킹을 부여하기 위한 랭킹 알고리즘의 필요성이 부각되고 있다. 기존에 웹 문서를 위한 다양한 랭킹 알고리즘들이 있었으나, 웹 문서와 포스트의 차이로 인하여 직접 적용하기 어렵다는 문제점이 존재한다. 본 논문에서는 블로거들이 포스트에 남긴 블로그 액션을 이용하여 포스트에 랭킹을 부여하는 방안인 포스트 랭킹 알고리즘들을 제안한다. 그리고 실제 블로그 데이터를 이용하여 포스트 랭킹 알고리즘들의 성능을 분석하고, 이를 바탕으로 블로그에 적합한 포스트 랭킹 알고리즘을 선별한다.