• 제목/요약/키워드: group sequential

검색결과 334건 처리시간 0.028초

Parallel sequential anastomosis를 이용한 관상동맥 우회수술의 성적 (Complete Myocardial Revascularization Utilizing Parallel Secluential Anastomoses)

  • 박계현;김관민
    • Journal of Chest Surgery
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    • 제30권7호
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    • pp.647-655
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    • 1997
  • 하나의 도관으로 여러 관상동맥 분지에 우회로를 조성하는 연속문합술은 관상동맥에 다중 협착을 가지고 있는 환자들에서 제한된 길이의 도관으로 심근의 완전 혈류재건의 목적을 달성할 수 있는 방법이다. 본 연 구에서는 연속문합술을 이용하여 관상동맥우회수술을 시행한 환자들(sequential group)과 연속문합술을 이용 하지 않은 환자들(non-sequential Voup)간의 수술후 조기 성적을 비교 분석함으로써 이 수술 방법의 실용성과 안전성을 검증하고자 하였다. 1995년 한해동안 79명의 환자가 관상동맥 우회수술을 시행받았으며 이중 39명에서 대복재정 맥을 이용한 연속 문합술이 사용되었다. 양군간에 수술전 상태의 수술 위험인자 동반 양상의 차이는 없었고 다만 sequential group에서 자주관상동맥 혹은 삼중혈관의 협착을 가진 환자의 비율이 높았다(87.2% vs. 45.0%). 총 318개의 원위부 문합이 이루어졌으며(sequential group; 198개=환자 1인당 5.1개, non-sequential group; 120 개=환자 1인당 3.0개) 원위부 문합 1개당 소요된 체외순환 시간과 대동맥 차단시간의 평균치는 sequential group에서는 각각 33.5분과 21.1분이었고 non-sequential group\ulcorner서는 각각 41.8분과 22.7분이었다. 수술후 조 기 사망은 non-sequential group에서만 2례 발생하였으며 양군간에 수술후 합병증의 발생율은 차이가 업었고 심근경색의 발생율 역시 차이가 없었다. 외래 추적 기간동안(2 to 15 개월) 8명(sequential group 3명, non-sequential gyoup 5명)의 환자가 협심증의 재발 혹은 지속을 호소하였다. 수술 전후에 모두 nIThallium 심 근 관류 스캔이 시행 가능하였던 30명의 소견을 분석한 결과 연속문합술로 우회로가 연결된 심근 분절의 83.3%와 단순문합술로 우회로가 연결된 심근 분절의 82.5%가 정상 혹은 수술전보다 호전된 관류양상을 보 이는 것으로 확인되었다. 이상의 결과로 대복재정 맥을 이용한 평행 연속문합 관상동맥우회 술은 그 조기성적이 만족스러움을 확인 하였으며 관상동맥계에 다중 복잡 협착을 가지고 있는 환자들에서 제한된 길이의 우회도관으로 심근의 완전 혈류재건을 달성할 수 있는 실용적이고 안전한 수술 방법이라 판단된다.

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Accuracy of Brownian Motion Approximation in Group Sequential Methods

  • Euy Hoon Suh
    • Communications for Statistical Applications and Methods
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    • 제6권1호
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    • pp.207-220
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    • 1999
  • In this paper, some of the issue about a group sequential method are considered in the Bayesian context. The continuous time optimal stopping boundary can be used to approximate the optimal stopping boundary for group sequential designs. The exact stopping boundary for group sequential design is obtained by using the backward induction method and is compared with the continuous optimal stopping boundary and the corrected continuous stopping boundary.

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ON SEQUENTIAL TOPOLOGICAL GROUPS

  • Ince, Ibrahim;Ersoy, Soley
    • 한국수학교육학회지시리즈B:순수및응용수학
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    • 제25권4호
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    • pp.243-252
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    • 2018
  • In this paper, we study the sequentially open and closed subsets of sequential topological groups determined by sequentially continuous group homomorphism. In particular, we investigate the sequentially openness (closedness) and sequentially compactness of subsets of sequential topological groups by the aid of sequentially continuity, sequentially interior or closure operators. Moreover, we explore subgroup and sequential quotient group of a sequential topological group.

Finding associations between genes by time-series microarray sequential patterns analysis

  • Nam, Ho-Jung;Lee, Do-Heon
    • 한국생물정보학회:학술대회논문집
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    • 한국생물정보시스템생물학회 2005년도 BIOINFO 2005
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    • pp.161-164
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    • 2005
  • Data mining techniques can be applied to identify patterns of interest in the gene expression data. One goal in mining gene expression data is to determine how the expression of any particular gene might affect the expression of other genes. To find relationships between different genes, association rules have been applied to gene expression data set [1]. A notable limitation of association rule mining method is that only the association in a single profile experiment can be detected. It cannot be used to find rules across different condition profiles or different time point profile experiments. However, with the appearance of time-series microarray data, it became possible to analyze the temporal relationship between genes. In this paper, we analyze the time-series microarray gene expression data to extract the sequential patterns which are similar to the association rules between genes among different time points in the yeast cell cycle. The sequential patterns found in our work can catch the associations between different genes which express or repress at diverse time points. We have applied sequential pattern mining method to time-series microarray gene expression data and discovered a number of sequential patterns from two groups of genes (test, control) and more sequential patterns have been discovered from test group (same CO term group) than from the control group (different GO term group). This result can be a support for the potential of sequential patterns which is capable of catching the biologically meaningful association between genes.

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Accelerating Group Fusion for Ligand-Based Virtual Screening on Multi-core and Many-core Platforms

  • Mohd-Hilmi, Mohd-Norhadri;Al-Laila, Marwah Haitham;Hassain Malim, Nurul Hashimah Ahamed
    • Journal of Information Processing Systems
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    • 제12권4호
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    • pp.724-740
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    • 2016
  • The performance issues of screening large database compounds and multiple query compounds in virtual screening highlight a common concern in Chemoinformatics applications. This study investigates these problems by choosing group fusion as a pilot model and presents efficient parallel solutions in parallel platforms, specifically, the multi-core architecture of CPU and many-core architecture of graphical processing unit (GPU). A study of sequential group fusion and a proposed design of parallel CUDA group fusion are presented in this paper. The design involves solving two important stages of group fusion, namely, similarity search and fusion (MAX rule), while addressing embarrassingly parallel and parallel reduction models. The sequential, optimized sequential and parallel OpenMP of group fusion were implemented and evaluated. The outcome of the analysis from these three different design approaches influenced the design of parallel CUDA version in order to optimize and achieve high computation intensity. The proposed parallel CUDA performed better than sequential and parallel OpenMP in terms of both execution time and speedup. The parallel CUDA was 5-10x faster than sequential and parallel OpenMP as both similarity search and fusion MAX stages had been CUDA-optimized.

임상실험에서 그룹축차방법들의 비교 (A comparison of group sequential methods in clinical trials)

  • 서의훈;안성진;임동훈
    • 응용통계연구
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    • 제10권2호
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    • pp.353-366
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    • 1997
  • 본 논문에서는 주어진 손실함수에 대한 근사최적베이즈축차실험방법을 유도한다. 근사최적베이즈축차실험방법을 Pocock 실험방법, O'Brien and Fleming 실험방법과 ASN(average sample size) 함수와 베이즈 위험면에서 비교하기 위하여 몬테칼로(Monte-Carlo) 방법을 사용한다. 그룹축차실험방법에서 그룹 때문에 빚어지는 정보의 손실비율과 베이즈효율의 개념을 소개하고 여러 가지 다른 그룹 크기에 따른 정보의 손실을 측정한다.

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집단축차검정법들에 관한 고찰 (An Overview of Group Sequential Procedures)

  • Jae Won Lee
    • 응용통계연구
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    • 제7권2호
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    • pp.35-51
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    • 1994
  • 윤리적 또는 경제적 이유 때문에 임상실험(Clinical Trials)의 연구자들은 실험중간에 새로운 치료방법이나 약이 효과가 있는지 또는 해로운지를 반복해서 검정한다. 하지만 각 검정마다 정해진 유의수준을 반복해서 사용하면 전체 유의수준이 상당히 커지게 된다. 임상실험에서 발생하는 이러한 문제를 해결하기 위하여 많은 집단측정검정법 (Group Sequential Testing Procedure)들이 개발되어 왔다. 본 논문에서는 이러한 집단측정검정법들을 간략하게 비교분석하고자 한다.

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소아 서혜부탈장 진단에 초음파검사 실시 후 임상 양상의 변화 (A Clinical Study of Pediatric Inguinal Hernia Before and After Using Ultrasonography for Diagnosis)

  • 이정은;최금자
    • Advances in pediatric surgery
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    • 제10권2호
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    • pp.131-135
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    • 2004
  • The purpose of this retrospective study was to evaluate the effects of diagnostic sonography in pediatric patients with inguinal hernias. The patients were classified into two groups. Group A included the patients who had been operated upon for inguinal hernia in 1980's, when diagnostic sonography was not available. Group B included the patients, operated upon for inguinal hernia from 2001 to 2002, when inguinal sonography was employed to detect potential bilateral hernias. The age distribution, sex ratio, laterality, bilaterality, and concomitant symptoms were compared between group A and group B. There were 296 cases in group A and 377 cases in group B. The prevalent age group was from 1 to 5 years. There was no difference in age group distribution between both groups. The male to female ratio was 5.3:1 in group A and 3.5:1 in group B. The ratio of unilateral to bilateral hernia was 5:1 in group A and 3:1 in group B. In cases with a unilateral hernia, the ratio of right to left was 1.5:1 in group A and 1.8:1 in group B. In cases with bilateral hernia, the simultaneous bilateral hernia was 33 cases (67.4 %) in group A and 75 cases (80.6 %) in group B. The sequential bilateral hernia was 16 cases (32.7 %) in group A and 18 cases (19.4 %) in group B. Although the ratio of bilateral hernia was increased in group B, the portion of the sequential bilateral hernia was significantly decreased in group B. In conclusion, there were no differences in the age distribution and the laterality between group A and B. The ratio of female patients and the incidence of bilateral hernia were increased in group B even though the portion of the sequential bilateral hernia was decreased. This result shows that the preoperative inguinal sonography in unilateral hernia with potential bilateral hernia is useful in early detection of the sequential contralateral hernia.

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$Clomid^{(R)}$(Clomiphene citrate)의 투여시기와 용량을 변수로 한 혈중 $Estradiol-17{\beta}$의 동태에 관한 연구 (A Comparative Analysis of Blood Estradiol-17${\beta}$ Levels According to Varying Regimens of $Clomid^{(R)}$(Clomiphene citrate) Administration in Induced Ovulated Menstrual Cycles)

  • 장호준;서병희;이재현
    • Clinical and Experimental Reproductive Medicine
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    • 제15권1호
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    • pp.40-52
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    • 1988
  • Estradiol-17${\beta}$($E_2$) levels in the blood were estimated according to varying the time and amount of the administration of $Clomid^{(R)}$. $Clomid^{(R)}$ were administered on the 2nd, 3rd and 4th menstrual day corresponding to the recruitment period and on the 5th menstrual day corresponding to the selection period of the ovarian follicles, respectively. And $Clomid^{(R)}$ were administered 50 mg, 100 mg and 150 mg/day, repectively. The effects of the sequential HMG to $E_2$ levels in the blood were also estimated. The results were as following : 1. Blood $E_2$ levels according to the day and amount of administration of $Clomid^{(R)}$ were the highest in the group 3(D $2{\sim}6$, 150 mg/day, with HMG) and the lowest in the group 6(D $5{\sim]9$, 50 mg/day, without HMG). $E_2$ levels showed increasing tendency to 0 day. 2. In the cases of the administration of $Clomid^{(R)}$ during the $2nd{\sim}6th$ menstrual day, $E_2$ levels according to the amount were similar among groups and showed increasing tendency daily. 3. In the cases of administration of $Clomid^{(R)}$ during the $2nd{\sim}6th$ menstrual day, $E_2$ levels according to the sequential HMG independent of the amount of $Clomid^{(R)}$ were higher in the with HMG group than without HMG groups. 4. In the case of the administration of $Clomid^{(R)}$ during the $5th{\sim}9th$ menstrual day, $E_2$ levels according to the amount were the highest in the 100 mg/day group and the lowest in the 50mg/day group. 5. In the cases of administration of $Clomid^{(R)}$ independent of the amount during the 5th${\sim}$9th menstrual day, $E_2$ levels according to the sequential HMG were higher in the with HMG group than without HMG group. 6. $E_2$ levels according to the amount independent of the day of the administration of $Clomid^{(R)}$ were the highest in the 100 mg/day group and 150 mg/day, 50 mg/day group in low sequence. 7. $E_2$ levels according to the sequential HMG independent of the day and amount of the administration of $Clomid^{(R)}$ were higher in the with HMG group than the without HMG group. 8. $E_2$ levels according to the day of the administration of $Clomid^{(R)}$ independent of the amount of $Clomid^{(R)}$ and sequential HMG were the highest in the group D 2${\sim}$6 and the lowest in the group D 5${\sim}$9. According to the above results, there were higher $E_2$ levels in the group with sequential HMG than without HMG. Therefore, the hypothesis, postulated initially by the author, was not verified that sequential HMG would not affect the $E_2$ levels which were related to the process of the selection of the ovarian follicle in the connection with 'FSH window'. Because it may be the stimulation after the selection of later predominant follicle. And the highest level of $E_2$ was estimated in the $Clomid^{(R)}$ 150 mg/day group with sequential HMG on the 2nd${\sim}$6th day, and the higher levels were estimated in the 2nd${\sim}$6th day, 3rd${\sim}$7th day and 4th${\sim}$8th day groups than the 5th${\sim}$9th day group. The lower levels were estimated in the $Clomid^{(R)}$ 50 mg/day group without HMG than 100 mg/day and 150 mg/day on the 5th${\sim}$9th day. Therefore, further study will be needed that combines analyses of the E2 levels in the blood according to the various administration of $Clomid^{(R)}$ with or without sequential HMG and determination of the numbers and size of the ovarian follicles by ultrasonogram.

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이산형 반응변수에서 오류 분배율 함수를 적용한 집단축차 검정 (Group Sequential Tests Using both Type I and Type II Error Spending Rate Functions on Binomial Response)

  • 김동욱;남진현
    • Communications for Statistical Applications and Methods
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    • 제17권1호
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    • pp.127-140
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    • 2010
  • 본 논문에서는 중간분석에서 사용되는 집단축차 검정법으로 이산형 반응변수인 경우, 오류 분배율 함수를 적용한 집단축차 검정법을 제안한다. 특히 제 1종 오류와 제 2종 오류를 모두 적용한 집단축차 검정법을 제안하며, 기존의 오류 분배율 함수를 포함하는 새로운 오류 분배율 함수를 제안한다. 반응변수가 이산형인 경우 정확한 크기 ${\alpha}$ 검정을 할 수 없으므로 각 검정단계에 사용될 오류율을 분배하는 대신 각 검정단계까지 사용되어야 할 누적 오류율을 이용한다. 오류 분배율 함수를 적용한 집단축차 검정은 기존의 집단축차 검정 보다 빠른 연산과 유연한 검정이 가능하다는 장점을 지니고 있으며, 본 논문에서 제시된 오류 분배율 함수를 이용해 특성을 비교한다.