• 제목/요약/키워드: Ranking

검색결과 1,950건 처리시간 0.03초

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.

Ranking of Websites of State Universities in Tamil Nadu using WISER and PRIMOEX: An Analytical Study

  • Dhanavandan, S.;Varadharajalu, J.
    • International Journal of Knowledge Content Development & Technology
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    • 제9권3호
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    • pp.7-22
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    • 2019
  • This Study examines and explores through a web metric ranking analysis of the websites of 22 state universities in Tamil Nadu. It discussed the domain systems of the websites; WISER Web ranking for the year 2016 and 2017. Similarly, the researchers manipulated a new ranking tools for ranking the websites of State universities of Tamil Nadu, According to WISER ranking, Anna University is ranked first with 2469.4 WISER value followed by Tamil Nadu Agricultural University which is ranked second with 4031.4 WISER value. University of Madras is ranked third with 4333.8 WISER values in the year 2017. But when we used the PRIMOEX ranking, Anna University is ranked first with 3653.3 PRIMOEX value followed by Tamil Nadu Agricultural University which is ranked second with 4090.6 PRIMOEX value. Madurai Kamaraj University is ranked third with 4136.1 PRIMOEX values. Alagappa University is ranked fourth with 4956.1 PRIMOEX value and Alagappa University with 6001.9 PRIMOEX value is ranked fifth. It found that PRIMOEX good tool to measure the ranking of websites of state universities of Tamil Nadu.

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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사용자 선호도 기반의 퍼지 랭킹모델에 관한 연구 (A Study on Fuzzy Ranking Model based on User Preference)

  • 김대원
    • 한국지능시스템학회:학술대회논문집
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    • 한국퍼지및지능시스템학회 2006년도 춘계학술대회 학술발표 논문집 제16권 제1호
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    • pp.94-95
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    • 2006
  • A great deal of research has been made to model the vagueness and uncertainty in information retrieval. One such research is fuzzy ranking models, which have been showing their superior performance in handling the uncertainty involved in the retrieval process. In this study we develop a new fuzzy ranking model based on the user preference. Through the experiments on the TREC-2 collection of Wall Street Journal documents, we show that the proposed method outperforms the conventional fuzzy ranking models.

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A Study on Fuzzy Ranking Model based on User Preference

  • Kim Dae-Won
    • 한국지능시스템학회논문지
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    • 제16권3호
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    • pp.326-331
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    • 2006
  • A great deal of research has been made to model the vagueness and uncertainty in information retrieval. One such research is fuzzy ranking models, which have been showing their superior performance in handling the uncertainty involved in the retrieval process. In this study we develop a new fuzzy ranking model based on the user preference. Through the experiments on the TREC-2 collection of Wall Street Journal documents, we show that the proposed method outperforms the conventional fuzzy ranking models.

퍼지 비교 기반 퍼지 숫자의 등급과 방법 (A Ranking Method for Fuzzy Numbers based on Fuzzy Comparisons)

  • 이지형;이광형
    • 한국정보과학회논문지:소프트웨어및응용
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    • 제28권12호
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    • pp.930-937
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    • 2001
  • 퍼지숫자의 정렬은 퍼지숫자를 크기 순서로 나열을 하는 것이다. 일반적으로 퍼지숫자의 정렬을 위해서는 퍼지숫자 사이의 비교가 필요한데. 피지숫자가 명확하지 않은 값을 표현하기 때문에. 그 비교 결과 역시 명확하지 않을 수 있다 따라서 그 비교결과를 이용한 정렬결과 역시 명확하지 않을 수 있다 그러나 지금가지 대부분의 연구는 퍼지숫자의 정렬 결과를 하나의 배역로만 명확하게 표현하였다. 본 논문 에서는 이러한 점을 고려하여 퍼지만족함수를 이용한 퍼지숫자 정렬방법을 제안한다. 퍼지만족함수는 두 퍼지숫자를 비교하여 그 대소를 0과 1사이의 퍼지집합으로 표현하는 퍼지비교방법이다. 제안하는 방법은 정렬결과로 단순히 하나의 배열만을 생성하지 않고, 퍼지숫자가 겹쳐서 생길 수 있는, 다른 가능한 정렬결 과들을 생성한다.

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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.

An Estimated Closeness Centrality Ranking Algorithm and Its Performance Analysis in Large-Scale Workflow-supported Social Networks

  • Kim, Jawon;Ahn, Hyun;Park, Minjae;Kim, Sangguen;Kim, Kwanghoon Pio
    • KSII Transactions on Internet and Information Systems (TIIS)
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    • 제10권3호
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    • pp.1454-1466
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    • 2016
  • This paper implements an estimated ranking algorithm of closeness centrality measures in large-scale workflow-supported social networks. The traditional ranking algorithms for large-scale networks have suffered from the time complexity problem. The larger the network size is, the bigger dramatically the computation time becomes. To solve the problem on calculating ranks of closeness centrality measures in a large-scale workflow-supported social network, this paper takes an estimation-driven ranking approach, in which the ranking algorithm calculates the estimated closeness centrality measures by applying the approximation method, and then pick out a candidate set of top k actors based on their ranks of the estimated closeness centrality measures. Ultimately, the exact ranking result of the candidate set is obtained by the pure closeness centrality algorithm [1] computing the exact closeness centrality measures. The ranking algorithm of the estimation-driven ranking approach especially developed for workflow-supported social networks is named as RankCCWSSN (Rank Closeness Centrality Workflow-supported Social Network) algorithm. Based upon the algorithm, we conduct the performance evaluations, and compare the outcomes with the results from the pure algorithm. Additionally we extend the algorithm so as to be applied into weighted workflow-supported social networks that are represented by weighted matrices. After all, we confirmed that the time efficiency of the estimation-driven approach with our ranking algorithm is much higher (about 50% improvement) than the traditional approach.

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.

누구에게? 어떤 선물을? : 선물 선택 시 심리적 거리를 중심으로 (What Gift and to Whom? : Choosing a Gift Based on Psychological Distance)

  • 이효원;강현모
    • 지식경영연구
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    • 제22권2호
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    • pp.95-117
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    • 2021
  • 본 연구에서는 선물할 때 선물할 대상과의 관계에 따라 어떤 대안을 선택하는지에 관해 알아보았다. 구체적으로 두 대안의 가격대가 비슷할 때, 브랜드 지위가 높지만, 브랜드 내 모델 랭킹은 낮은 제품과 브랜드 지위는 낮지만, 모델 랭킹은 높은 제품중 어떤 대안을 더 선호하는지에 관해 실험을 통해 연구하였다. 해석 수준 이론(Construal level theory)을 바탕으로 선물할 대상과의 관계(수직적 관계 vs. 수평적 관계)와 친밀도에 따라 카테고리 효과(category effect, 높은 지위 브랜드의 낮은 랭킹 모델 선호)와 랭킹 효과(ranking effect, 낮은 지위 브랜드의 높은 랭킹 모델 선호)가 다르게 나타난다고 제안하였다. 연구 결과, 심리적 거리에 따라 대안의 선택이 달라짐을 확인할 수 있었다. 구체적으로 수직적 관계에 있는 대상에게 선물할 경우에는 카테고리 효과가 크게 나타났지만, 선물할 대상이 수평적 관계인 경우에는 랭킹 효과가 나타났다. 또한 수직적 관계와 비교할 때, 수평적 관계에서 친밀도에 따른 랭킹효과(또는 카테고리 효과)의 차이가 더 크게 나타났다. 이처럼, 본 연구에서는 선물할 대상과의 관계와 친밀도의 심리적 거리에 따라서 브랜드 지위와 모델 랭킹에 대한 제품의 선택이 달라질 수 있다는 것을 보였다.