• 제목/요약/키워드: set-valued attributes

검색결과 7건 처리시간 0.016초

집합 값을 갖는 애트리뷰트에 대한 수직적으로 분할된 블록 중첩 루프 조인 (Vertically Partitioned Block Nested Loop join on Set-Valued Attributes)

  • 황환규
    • 산업기술연구
    • /
    • 제28권B호
    • /
    • pp.209-214
    • /
    • 2008
  • Set-valued attributes appear in many applications to model complex objects occurring in the real world. One of the most important operations on set-valued attributes is the set join, because it provides a various method to express complex queries. Currently proposed set join algorithms are based on block nested loop join in which inverted files are partitioned horizontally into blocks. Evaluating these joins are expensive because they generate intermediate partial results severely and finally obtain the final results after merging partial results. In this paper, we present an efficient processing of set join algorithm. We propose a new set join algorithm that vertically partitions inverted files into blocks, where each block fits in memory, and performs block nested loop join without producing intermediate results. Our experiments show that the vertical bitmap nested set join algorithm outperforms previously proposed set join algorithms.

  • PDF

An Application of the Rough Set Approach to credit Rating

  • Kim, Jae-Kyeong;Cho, Sung-Sik
    • 한국지능정보시스템학회:학술대회논문집
    • /
    • 한국지능정보시스템학회 1999년도 추계학술대회-지능형 정보기술과 미래조직 Information Technology and Future Organization
    • /
    • pp.347-354
    • /
    • 1999
  • The credit rating represents an assessment of the relative level of risk associated with the timely payments required by the debt obligation. In this paper, we present a new approach to credit rating of customers based on the rough set theory. The concept of a rough set appeared to be an effective tool for the analysis of customer information systems representing knowledge gained by experience. The customer information system describes a set of customers by a set of multi-valued attributes, called condition attributes. The customers are classified into groups of risk subject to an expert's opinion, called decision attribute. A natural problem of knowledge analysis consists then in discovering relationships, in terms of decision rules, between description of customers by condition attributes and particular decisions. The rough set approach enables one to discover minimal subsets of condition attributes ensuring an acceptable quality of classification of the customers analyzed and to derive decision rules from the customer information system which can be used to support decisions about rating new customers. Using the rough set approach one analyses only facts hidden in data, it does not need any additional information about data and does not correct inconsistencies manifested in data; instead, rules produced are categorized into certain and possible. A real problem of the evaluation of the evaluation of credit rating by a department store is studied using the rough set approach.

  • PDF

XML 응용시스템 개발을 위한 설계방안 (A Design Methodology for XML Applications)

  • 김경수;주경수
    • 대한전자공학회:학술대회논문집
    • /
    • 대한전자공학회 2000년도 하계종합학술대회 논문집(3)
    • /
    • pp.39-42
    • /
    • 2000
  • Extensible Markup Language(XML) is fast emerging as the dominant standard for representing data in the World Wide Web. Sophisticated query engines that allow users to effectively tap the data stored in XML documents will be crucial to exploiting the full power of XML. While there has been a great deal of activity recently proposing new semi-structured data models and query languages for this purpose, this paper explores the more conservative approach of using traditional relational database engines for processing XML documents conforming to Document Type Descriptors(DTDs). In this paper, we describe how to generate relational schemas from XML DTDs. The main issues that must be addressed inc]ode (a) dealing with the complexity of DTD element specifications (b) resolving the conflict between the two-level nature of relational schemas (table and attribute) vs. the arbitrary nesting of XML DTD schemas and (c) dealing with set-valued attributes and recursion. We now propose a set of transformations that can be used to "simplify" any arbitrary DTD without undermining the effectiveness of queries over documents conforming to that DTD.

  • PDF

A Hybrid Multi-Level Feature Selection Framework for prediction of Chronic Disease

  • G.S. Raghavendra;Shanthi Mahesh;M.V.P. Chandrasekhara Rao
    • International Journal of Computer Science & Network Security
    • /
    • 제23권12호
    • /
    • pp.101-106
    • /
    • 2023
  • Chronic illnesses are among the most common serious problems affecting human health. Early diagnosis of chronic diseases can assist to avoid or mitigate their consequences, potentially decreasing mortality rates. Using machine learning algorithms to identify risk factors is an exciting strategy. The issue with existing feature selection approaches is that each method provides a distinct set of properties that affect model correctness, and present methods cannot perform well on huge multidimensional datasets. We would like to introduce a novel model that contains a feature selection approach that selects optimal characteristics from big multidimensional data sets to provide reliable predictions of chronic illnesses without sacrificing data uniqueness.[1] To ensure the success of our proposed model, we employed balanced classes by employing hybrid balanced class sampling methods on the original dataset, as well as methods for data pre-processing and data transformation, to provide credible data for the training model. We ran and assessed our model on datasets with binary and multivalued classifications. We have used multiple datasets (Parkinson, arrythmia, breast cancer, kidney, diabetes). Suitable features are selected by using the Hybrid feature model consists of Lassocv, decision tree, random forest, gradient boosting,Adaboost, stochastic gradient descent and done voting of attributes which are common output from these methods.Accuracy of original dataset before applying framework is recorded and evaluated against reduced data set of attributes accuracy. The results are shown separately to provide comparisons. Based on the result analysis, we can conclude that our proposed model produced the highest accuracy on multi valued class datasets than on binary class attributes.[1]

Bio-XML 관리를 위한 DTD 의존적 객체 데이터베이스 스키마 설계기법 (DTD-dependent object database schema design methods for efficiently managing Bio-XML)

  • 김태경;이경희;조완섭
    • 한국콘텐츠학회:학술대회논문집
    • /
    • 한국콘텐츠학회 2003년도 추계종합학술대회 논문집
    • /
    • pp.285-289
    • /
    • 2003
  • 본 논문에서는 Bio-XML 문서를 효율적으로 객체 데이터베이스에 저장하고, XML 질의에서 주로 사용되는 경로식을 효과적으로 처리할 수 있는 DTD의존적인 객체 데이터베이스 스키마 설계기법을 제안한다. XML DTD와 객체데이터베이스의 스키마는 구조적으로 비슷하고, 객체 데이터베이스의 고유특성인 객체 참조와 집합값 속성은 XML 데이터를 저장하는데 유리하다. 본 논문에서는 객체 데이터베이스의 고유 특성을 충분히 반영하여 두 가지의 스키마 설계기법인 기본적 방법과 인라인 방법을 제안한다. 뿐만 아니라, 각각 설계 기법에 대하여 시스템성능 평가를 수행하였으며, 설계 기법에 따른 공간효율과 시간 효율을 비교 및 분석하였다.

  • PDF

선택실험법을 이용한 산양삼의 경제적 가치평가 (Estimation on Economic Value for Cultivated Wild Ginseng using Choice Experiment)

  • 김의경;김동현
    • 한국산림과학회지
    • /
    • 제102권3호
    • /
    • pp.338-344
    • /
    • 2013
  • 이 연구는 산양삼의 상품 속성에 대하여 소비자들이 얼마만큼의 가치를 부여하고자 하는지를 파악하고 그것에 대한 경제적 가치를 평가하고 한다. 이를 위해 선택실험기법을 이용하였으며, 선택실험기법에 사용된 속성은 재배연령, 식재방법, 산양삼의 몸통 크기, 산양삼의 수염뿌리 길이, 색채 등과 같이 외관 특징에 기초하였다. 분석을 위해 모집단은 서울을 포함한 수도권에 거주하는 일반시민을 대상으로 하였으며, 조사방법은 설문면접조사로 총 173부의 설문지를 획득하였다. 분석결과, 모형은 안정적인 범위에 속하였으며, 응답자는 직파삼에 대하여 가장 높은 가 치를 부여한 반면 몸통크기에 대해서는 상대적으로 그 가치가 낮은 것으로 나타났다.

A Study on Pattern Recognition to Compute Guidelines Based on Evidence for Ecological Healing Environment at Agha Khan Hospital in Karachi - Focused on Human Thermal Comfort Model (HTCM), for Karachi, using Climate Consultant Program

  • Shaikh, Javaria Manzoor;Park, Jae Seung
    • KIEAE Journal
    • /
    • 제15권2호
    • /
    • pp.27-35
    • /
    • 2015
  • Purpose: Healthcare is on the whole a personal and critical service that consumer's use, whereas hospitalization is as a rule painful, because nature nurtures and Sun Light Luminosity for healthcare settings is considered healing. The performance and design of climate responsive buildings such as AKU requires a detailed study of attributes of climate both at micro as well as macro level. The therapeutic value of contact with nature through window view, greenery and landscape is calculated there. Method: A two prong strategy is been devised for this article, at micro level three typical morphologies are analysed by creating same environment of neighboring building on sun shading chart, radiation and temperature range. Since the analysis of local climate helps to determine the design strategies for hospital Healing Environment which is suitable for Karachi climate; in order to track the macro climatic behaviour, a considerable analysis of psychometrics chart for AKU Karachi are designed on Climate Consultant (CC) and analysed by Machine Learning. Climate Consultant proposes different design strategies suitable for Karachi. And on the other hand time wise illumination sources for clinical area which are then measured on psychrometric chart- according to singular space: multi patient admission, secondly: acute ambulatory ward, and tertiary: multi windowed space according to the mushrabiyah and sky light pattern. Result: Our findings support the hypothesis that windowed wall is 75-80% more healing wall; an accelerated evidence was found for healing at macro level if the form of the hospital is designed according to the climatologically preferences, whereas at micro level: the light resource becomes the staff attentiveness determinant. In Conclusion evidence was provided that the actual form of luminosity results consequently in satisfaction while light entering from several set of windows and other sources might be valued if design according to the healing environment. The data added on the sun shading chart to calculate rays entraining into space in patient room equal to 124416.21 Watts/ meter $m^2$ is calculated as precise healing rate-and is confirmed by questionnaire from patients belonging from each clinical stage having different illnesses.