• 제목/요약/키워드: Stepwise Approach

검색결과 126건 처리시간 0.018초

Feature Selection for Multi-Class Support Vector Machines Using an Impurity Measure of Classification Trees: An Application to the Credit Rating of S&P 500 Companies

  • Hong, Tae-Ho;Park, Ji-Young
    • Asia pacific journal of information systems
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    • 제21권2호
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    • pp.43-58
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    • 2011
  • Support vector machines (SVMs), a machine learning technique, has been applied to not only binary classification problems such as bankruptcy prediction but also multi-class problems such as corporate credit ratings. However, in general, the performance of SVMs can be easily worse than the best alternative model to SVMs according to the selection of predictors, even though SVMs has the distinguishing feature of successfully classifying and predicting in a lot of dichotomous or multi-class problems. For overcoming the weakness of SVMs, this study has proposed an approach for selecting features for multi-class SVMs that utilize the impurity measures of classification trees. For the selection of the input features, we employed the C4.5 and CART algorithms, including the stepwise method of discriminant analysis, which is a well-known method for selecting features. We have built a multi-class SVMs model for credit rating using the above method and presented experimental results with data regarding S&P 500 companies.

판별분석을 통한 패밀리레스토랑의 고객 분류와 마케팅전략에 관한 연구 (A Multiple Discriminant Approach to Identifying Frequent Users of Eating out at Family Restaurant)

  • 강종헌
    • 한국식품조리과학회지
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    • 제18권1호
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    • pp.109-118
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    • 2002
  • The purpose of this study was to identify the behavioral, attitudinal, and demographic correlates of light, medium, and heavy users of eating out at family restaurants. Among 358 reponses from the subjects, 224 responses were utilized for the analysis, and 134 responses were reserved for validating the discriminant function. Descriptive statistics, reliability analysis, stepwise discriminant analysis, canonical discriminant analysis, and anova analysis were used for this study. The findings from this study were as follows: First, He behavioral characteristics were found to discriminate among the three usage groups. Second, it was found that heavy users expressed greater difference between perception and expectation on the quantity of food that are appropriately served and the consistent quality of food at every visit. Third, the usage rate of eating out was not dependent on the sex, but dependent on the companion, average expenditure, and the time of eating out in chi-square test. Finally, the results of the study provide some insight into the pattern of marketing strategies that can be successfully used by the managers of family restaurants.

Development of Practical Data Mining Methods for Database Summarization

  • Lee, Do-Heon
    • 정보기술과데이타베이스저널
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    • 제4권2호
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    • pp.33-45
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    • 1998
  • Database summarization is the procedure to obtain generalized and representative descriptions expressing the content of a large amount of database at a glance. We present a top-down summary refinement procedure to discover database summaries. The procedure exploits attribute concept hierarchies that represent ISA relationships among domain concepts. It begins with the most generalized summary and proceeds to find more specialized ones by stepwise refinements. This top-down paradigm reveals at least two important advantages compared to the previous bottom-up methods. Firstly, it provides a natural way of reflecting the user's own discovery preference interactively. Secondly, it does not produce too large intermediate result that makes it hard for the bottom-up approach to be applied in practical environment. The proposed procedure can also be easily extended for distributed databases. Information content measure of a database summary is derived in order to identify more informative summaries among the discovered results.

New Calculation of Charge Generation Efficiency and Photocurrent in Organic Photoconducting Device

  • Lee, Choong-Kun;Oh, Jin-Woo;Choi, Chil-Sung;Lee, Nam-Soo;Kim, Nak-Joong
    • Bulletin of the Korean Chemical Society
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    • 제30권1호
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    • pp.97-101
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    • 2009
  • A new approach was applied to examine the charge generation and transport in organic photoconductive devices by Monte‐Carlo simulation utilizing multiple site interactions of carriers with all other charges within Coulomb radius. Stepwise generation frame was considered first by a charge separation process that was counted in two separate transactions, i.e., hopping against physical decay and dissociation against recombination. Thereafter, diffusion/ drifting process of free carriers was counted to follow. This method enables to examine readily the photocurrent generated alongside the charge generation efficiency. The field and temperature dependences of the efficiency and photocurrent were obtained comparable to Onsager’s and experimental data.

산업 R&D 성과의 시간지연에 관한 분석 (A Study on the Time-lag of Industrial R&D Output)

  • 이재하;권철신
    • 기술혁신연구
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    • 제7권1호
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    • pp.176-186
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    • 1999
  • This paper starts out by reviewing the literature that in different ways utilizes patent data as an output of Research & Development (R&D) investment. The main focus, however, is an analysis of time-lag between industrial R&D input and its output. To achieve this research's purpose, the basic data associated with the industrial R&D input (expenditure, researchers) and output (applied patent and utilities) for the past 15 years, from 1980 to 1994, in the areas of electrical-electronic, mechanical and chemical industries have been collected. And the raw input data were altered into real flow data (but stock data) using Laspeyres approach and analyzed using multiple regression analysis, especially stepwise regression analysis. The result of this study can be summarized as follows: a) The time-lag; between industrial R&D input and its output is within 1 to 3 years. b) The time-lag: of patents was longer than that of utility models. c) The time-lag: in electrical-electronic, chemical industry was longer than that of the mechanical industry.

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급성관동맥증후군을 동반한 심방세동 환자에서 NOAC 치료 (NOAC for Patients with AF and ACS)

  • 김동혁;최종일
    • International Journal of Arrhythmia
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    • 제17권1호
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    • pp.41-45
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    • 2016
  • Atrial fibrillation (AF) can occur in acute coronary syndrome (ACS), which is a serious medical condition and may require the use of antiplatelet agents in addition to anticoagulants for stroke prevention. Recently, novel or non-vitamin K antagonist oral anticoagulants (NOACs) have been increasingly used for stroke prevention in patients with AF instead of traditional OACs. The duration of treatment or treatment with a stepwise approach (e.g. triple, double, or monotherapy) is determined depending on the clinical setting and the balance between the risks of ischemic stroke and bleeding. However, some concerns and controversies in the use of NOACs in patients with AF and ACS need to be addressed. Here, the current management for NOAC therapy in patients with ACS and AF will be reviewed based on recently published guidelines.

Relationship between Spiritual Health and Quality of Life in Patients with Cancer

  • Mohebbifar, Rafat;Pakpour, Amir H;Nahvijou, Azin;Sadeghi, Atefeh
    • Asian Pacific Journal of Cancer Prevention
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    • 제16권16호
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    • pp.7321-7326
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    • 2015
  • As the essence of health in humans, spiritual health is a fundamental concept for discussing chronic diseases such as cancer and a major approach for improving quality of life in patients is through creating meaningfulness and purpose. The present descriptive analytical study was conducted to assess the relationship between spiritual health and quality of life in 210 patients with cancer admitted to the Cancer Institute of Iran, selected through convenience sampling in 2014. Data were collected using Spiritual Health Questionnaire and the European Organization for Research and Treatment of Cancer Quality of Life Questionnaire (EORTC-QLQ). Patients' performance was assessed through the Karnofsky Performance Status Indicator and their cognitive status through the Mini-Mental State Examination (MMSE). Data were analyzed in SPSS-16 using descriptive statistics and stepwise linear regression. The results obtained reported the mean and standard deviation of the patients' spiritual health scoreas $78.4{\pm}16.1$ and the mean and standard deviation of their quality of life score as $58.1{\pm}18.7$. The stepwise linear regression analysis confirmed a positive and significant relationship between spiritual health and quality of life in patients with cancer (${\beta}$=0.688 and r=0.00). The results of the study show that spiritual health should be more emphasized and reinforced as a factor involved in improving quality of life in patients with cancer. Designing care therapies and spiritual interventions is a priority in the treatment of these patients.

A working paradigm for managing mandibular fractures under regional anesthesia

  • Chellappa, Natarajan;Meshram, Vikas;Kende, Prajwalit;Landge, Jayant;Aggarwal, Neha;Tiwari, Manish
    • Journal of the Korean Association of Oral and Maxillofacial Surgeons
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    • 제44권6호
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    • pp.275-281
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    • 2018
  • Objectives: Isolated mandibular fractures contribute to approximately 45% of maxillofacial traumas. Improper management of mandibular fractures can cause myriad potential complications and can lead to serious functional and aesthetic sequelae. The objective of the study is to design a stepwise approach for managing isolated mandibular fractures using open reduction and internal fixation (ORIF) with regional anesthesia on outpatient basis. Materials and Methods: Patients with isolated mandibular fractures presenting to the department of maxillofacial surgery were selected for ORIF under regional anesthesia based on occlusion, age, socioeconomic status, general condition, habits, and allied medical ailments. Standard preoperative, intraoperative, and postoperative protocols were followed. All patients were followed up for a minimum of 4 weeks up to a maximum of 1 year. Results: Of 23 patients who received regional anesthesia, all but one had good postoperative functional occlusion. One patient was hypersensitive and had difficulty tolerating the procedure. Two patients developed an extraoral draining sinus, one of whom was managed with local curettage, while the other required hardware removal. One patient, who was a chronic alcoholic, returned 1 week after treatment with deranged fracture segments after he fell while intoxicated. Conclusion: With proper case selection following a stepwise protocol, the majority of mandibular fractures requiring ORIF can be managed with regional anesthesia and yield minimal to no complications.

프랑스 방사성폐기물 관리 법제화 사례의 적용성 연구 (A Study on Applicability of French Legislative Approach for Radioactive Waste Management)

  • 노현엽;이건희;김종빈
    • 방사성폐기물학회지
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    • 제13권3호
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    • pp.219-227
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    • 2015
  • 방사성폐기물의 처리와 관리는 원자력을 이용하는 국가들이 반드시 해결해야 하는 중요한 문제이다. 오늘날 동 사안에 대해서는 극소수의 국가들만이 실질적인 진척이 있으며, 그 중 프랑스의 관련 정책이 대표적인 성공 사례로 평가되고 있다. 한국의 경우에 있어서도 방사성폐기물의 관리에 대한 적절한 정책의 준비가 필요하며, 이에 프랑스 법제화 접근법을 적용하자는 제안들이 있다. 동 연구는 그 적용성 검토를 위해 방사성폐기물의 관리와 관련된 두 나라의 기술 현황 및 사회정책적 지표를 비교하였으며, 자원 재활용과 사회적 수용성 증진 전략 측면에서 프랑스식 법제화 모델을 반영하는 것이 바람직하다고 판단한다.

우리나라 병원건축물의 내진성능향상을 위한 기초연구 (Preliminary Study on the Enhancement of Seismic Performance of Korea Hospital Buildings)

  • 김남희;홍성걸
    • 한국지진공학회논문집
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    • 제20권7_spc호
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    • pp.509-516
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    • 2016
  • Secure operation of hospitals during and right after earthquake is essential. Past lessons from earthquake damages have shown that most of the injured and the death occurred within 30 minutes after earthquake and the portion of nonstructural damage has become significant. However, hospital buildings in Korea have not prepared fully to address such rising issues. This paper is to study what type of damage patterns are related to hospital buildings and how to develop a preparedness plan to keep hospitals operational at all earthquakes if possible. This paper first reviews on past earthquake damages reported as critical to hospital buildings while classifying them into four groups: (1) structural element; (2) architectural-nostructural element; (3) medical equipments and contents; and (4) utility facility. Upon such classification, some detailed concerns can be specified under each group explicitly. Then a hierarchy for hospital building is also developed for the classified groups, which enables us to identify required things for the enhancement of seismic performance of hospital building that consists of heterogeneous elements. To upgrade the level of seismic performance for existing hospital buildings, the concept of performance-based approach can be adopted to address the heterogeneous problems in a systematic and stepwise manner. Finally a conceptual framework for the seismic risk assessment for hospital building is proposed toward the seismic enhancement of hospital buildings using performance-based approach.