• 제목/요약/키워드: Randomization test

검색결과 51건 처리시간 0.021초

A Two Sample Test for Functional Data

  • Lee, Jong Soo;Cox, Dennis D.;Follen, Michele
    • Communications for Statistical Applications and Methods
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    • 제22권2호
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    • pp.121-135
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    • 2015
  • We consider testing equality of mean functions from two samples of functional data. A novel test based on the adaptive Neyman methodology applied to the Hotelling's T-squared statistic is proposed. Under the enlarged null hypothesis that the distributions of the two populations are the same, randomization methods are proposed to find a null distribution which gives accurate significance levels. An extensive simulation study is presented which shows that the proposed test works very well in comparison with several other methods under a variety of alternatives and is one of the best methods for all alternatives, whereas the other methods all show weak power at some alternatives. An application to a real-world data set demonstrates the applicability of the method.

QSPR Study of the Absorption Maxima of Azobenzene Dyes

  • Xu, Jie;Wang, Lei;Liu, Li;Bai, Zikui;Wang, Luoxin
    • Bulletin of the Korean Chemical Society
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    • 제32권11호
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    • pp.3865-3872
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    • 2011
  • A quantitative structure-property relationship (QSPR) study was performed for the prediction of the absorption maxima of azobenzene dyes. The entire set of 191 azobenzenes was divided into a training set of 150 azobenzenes and a test set of 41 azobenzenes according to Kennard and Stones algorithm. A seven-descriptor model, with squared correlation coefficient ($R^2$) of 0.8755 and standard error of estimation (s) of 14.476, was developed by applying stepwise multiple linear regression (MLR) analysis on the training set. The reliability of the proposed model was further illustrated using various evaluation techniques: leave-many-out crossvalidation procedure, randomization tests, and validation through the test set.

통신시스템용 등화기 모듈을 위한 UVM 기반 검증 (UVM-based Verification of Equalizer Module for Telecommunication System)

  • 문대원;홍대기
    • 반도체디스플레이기술학회지
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    • 제23권1호
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    • pp.25-35
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    • 2024
  • In the present modern day, as the complexity and size of SoC(System on Chip) increase, the importance of design verification are increasing, Therefore it takes a lot of time to verify the design. There is an emerging need to manage the verification environment faster and more efficiently by reusing the existing verification environment. UVM-based verification is a standardized and highly reliable verification method widely adopted and used in the semiconductor industry. This paper presents a UVM-based verification for the 4 tap equalizer module with a systolic array structure. Through the constraints randomization, it was confirmed that various test scenarios stimulus were generated. In addition, by verifying a simulation comparing the actual DUT outputs with the MATLAB reference outputs, the reuse and efficiency of the UVM test bench could be confirmed.

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결혼준비교육 프로그램의 적용 효과 (Effects of a Premarital Education Program for Single person)

  • 이성희;김희숙
    • 여성건강간호학회지
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    • 제13권4호
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    • pp.272-279
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    • 2007
  • Purpose: The purpose was to test the effects of a premarital education program for singles on their sex role attitude and marriage expectations. Method: Forty seven single people were recruited through website advertisements. Volunteers were randomly assigned either to participate in a 4 week premarital education program(2 hours per week)(n=23) or the option to get a hand-out used with the experimental group after a post-test(n=24). An interviewer blinded to the randomization collected questionnaire data from all subjects at pre and post test. The program covered 2 thematic areas: the value of marriage and gender equity-relations. The data was analyzed using $X^2$-test, t-test, and ANCOVA. Result: There was a significant difference in the marriage-expectation score between the two groups. However, the sex role attitudes score in the experimental group was not significantly different from that of the control group. Conclusion: This premarital education program for singles had positive effects on marriage expectations but not on sex role attitude. Longer follow-up might be needed to evaluate these effects.

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Development of kNN QSAR Models for 3-Arylisoquinoline Antitumor Agents

  • Tropsha, Alexander;Golbraikh, Alexander;Cho, Won-Jea
    • Bulletin of the Korean Chemical Society
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    • 제32권7호
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    • pp.2397-2404
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    • 2011
  • Variable selection k nearest neighbor QSAR modeling approach was applied to a data set of 80 3-arylisoquinolines exhibiting cytotoxicity against human lung tumor cell line (A-549). All compounds were characterized with molecular topology descriptors calculated with the MolconnZ program. Seven compounds were randomly selected from the original dataset and used as an external validation set. The remaining subset of 73 compounds was divided into multiple training (56 to 61 compounds) and test (17 to 12 compounds) sets using a chemical diversity sampling method developed in this group. Highly predictive models characterized by the leave-one out cross-validated $R^2$ ($q^2$) values greater than 0.8 for the training sets and $R^2$ values greater than 0.7 for the test sets have been obtained. The robustness of models was confirmed by the Y-randomization test: all models built using training sets with randomly shuffled activities were characterized by low $q^2{\leq}0.26$ and $R^2{\leq}0.22$ for training and test sets, respectively. Twelve best models (with the highest values of both $q^2$ and $R^2$) predicted the activities of the external validation set of seven compounds with $R^2$ ranging from 0.71 to 0.93.

실행시간 침입 방지 평가 프로그램(RIPE)의 개선 (Improvement of Runtime Intrusion Prevention Evaluator (RIPE))

  • 이현규;이담호;김태환;조동황;이상훈;김훈규;표창우
    • 정보과학회 논문지
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    • 제42권8호
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    • pp.1049-1056
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    • 2015
  • 2011년에 발표된 RIPE는 프로그램 공격에 대한 완화 기법 평가 도구로서 850 가지 패턴의 버퍼 오버플로우 기반 공격에 대한 완화 기법만을 평가한다. RIPE는 공격과 방어 루틴이 하나의 프로세스로 실행되도록 구성되어, RIPE가 실행될 때에는 공격과 방어 루틴이 프로세스 상태와 주소 공간 배치를 공유할 수밖에 없게 된다. 그 결과 공격 루틴은 방어 루틴의 메모리 공간을 아무런 제약 없이 접근할 수 있게 된다. 이 논문에서는 RIPE의 공격과 방어 루틴이 독립적인 2개의 프로세스로 동작하도록 하여 주소 공간 배치 난독화와 같은 기밀성에 근거한 방어 기법을 정확히 평가할 수 있도록 개선하였다. 또한 억지 공격에 대한 방어 능력을 실험할 수 있도록 실행 모드를 추가하였다. 마지막으로 vtable 포인터 공격과 형식문자열 공격을 수행하도록 38 가지 패턴의 공격을 추가하여 확장하였다. 개선 결과 공격 패턴이 다양하게 되었고, 보호 효과 평가의 정확성도 높아졌다.

Preventive effects of ginseng against atherosclerosis and subsequent ischemic stroke: A randomized controlled trial (PEGASUS trial)

  • Kwon, Boseong;Song, Yunsun;Kim, Joong-Goo;Lee, Dongwhane;Lee, Sang-hun;Cho, Young-Keol;Kim, Jong S.;Suh, Dae Chul
    • Journal of Ginseng Research
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    • 제46권4호
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    • pp.585-591
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    • 2022
  • Background: Korean Red Ginseng (KRG) extract has been shown to have beneficial effects in patients with atherosclerosis, suggesting that KRG extract may be effective in preventing subsequent ischemic stroke in patients with severe atherosclerosis. Methods: This double-blind, placebo-controlled trial randomized patients with severe atherosclerosis in major intracranial arteries or extracranial carotid artery, to ginseng group and placebo group. They were given two 500-mg KRG tablets or identical placebo tablets twice daily for 12 months according to randomization. The primary endpoint was the composite of cerebral ischemic stroke and transient ischemic attack during 12 months after randomization. The secondary endpoints were change in volumetric blood flow of the intracranial vessels and the incidence of newly developed asymptomatic ischemic lesions. Any adverse events were monitored. Results: Fifty-eight patients were randomized from June 2016 to June 2017, 29 to ginseng and 29 to placebo, and 52 (28 and 24, respectively) completed the study. One patient in the placebo group, but none in the ginseng group, experienced ischemic symptoms (p = 0.46). Changes in volumetric blood flow and the presence of ischemic brain lesions did not differ significantly in the two groups, and none of these patients experienced adverse drug reactions. Conclusion: Ginseng was well tolerated by patients with severe atherosclerosis, with these patients showing good compliance with ginseng dosing. Ginseng did not show significant effects compared with placebo, although none of the ginseng-treated patients experienced ischemic events. Long-term studies in larger patient populations are required to test the effect of ginseng.

실험설계법 기반 풍동실험 정밀도 향상 실험연구 (Experimental Investigations of Accuracy Improvement in Wind Tunnel Testing Using Design of Experiments)

  • 오세윤;박승오;안승기
    • 한국항공우주학회지
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    • 제42권4호
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    • pp.291-297
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    • 2014
  • 회전익 항공기의 기체 공력특성 측정실험에 실험설계 방법론을 적용하여 풍동실험의 정밀도 향상에 관한 연구를 수행하였다. 블록화와 블록화 되지 않은 경우들에 대한 분산분석결과의 비교를 통해 블록화의 영향을 평가하였다. 2차 반응표면모델의 경우 블록화가 실험결과의 정밀도 향상에 실질적인 영향을 주고 있음을 알 수 있었다. 본 연구를 통해 랜덤화, 블록화 및 반복화와 같은 실험설계원리와 같은 풍동실험 절차의 재배치를 통해 이러한 정밀도 향상이 가능함을 보였다.

초음파시험의 미소결함탐지능에 영향을 미치는 미세조직과 시험조건의 영향 (Effects of the Microstructure and the Testing Conditions for the Detectability of the Small Flaw in Ultrasonic Testing)

  • 이재옥;김영길
    • 비파괴검사학회지
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    • 제9권1호
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    • pp.83-89
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    • 1989
  • Effects of the microstructure and the testing conditions for the detectability of the small flaw in ultrasonic testing have been studied. The detectability of the flaw was influenced not only by the grain size but also by the microstructure of the test piece. This is considered to be caused by randomization of the matrix which influences the elastic anisotropy of the grain. It was found that the detectability was improved as the frequence became higher and the beam size became smaller. The experimental results indicate that ultrasonic backscattering measurement is one of the promising methods to evaluate the detectability of the flaw indirectly.

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Random Forest Model for Silicon-to-SPICE Gap and FinFET Design Attribute Identification

  • Won, Hyosig;Shimazu, Katsuhiro
    • IEIE Transactions on Smart Processing and Computing
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    • 제5권5호
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    • pp.358-365
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    • 2016
  • We propose a novel application of random forest, a machine learning-based general classification algorithm, to analyze the influence of design attributes on the silicon-to-SPICE (S2S) gap. To improve modeling accuracy, we introduce magnification of learning data as well as randomization for the counting of design attributes to be used for each tree in the forest. From the automatically generated decision trees, we can extract the so-called importance and impact indices, which identify the most significant design attributes determining the S2S gap. We apply the proposed method to actual silicon data, and observe that the identified design attributes show a clear trend in the S2S gap. We finally unveil 10nm key fin-shaped field effect transistor (FinFET) structures that result in a large S2S gap using the measurement data from 10nm test vehicles specialized for model-hardware correlation.