• 응용통계연구
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• 제21권3호
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• pp.509-521
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• 2008

평균과 분산이 동시에 변화할 수 있는 공정을 관리할 경우, 평균의 변화를 탐지하는 관리도와 분산의 변화를 탐지하는 관리도를 병행하여 사용하는 것이 일반적이다. 여러 연구자들이 하나의 관리도를 사용하여 공정 평균과 분산의 변화를 동시에 탐지할 수 있는 절차를 제안했는데, 이 논문에서는 이와 같은 관리도들을 소개하고 그 효율을 비교하였다. 그 결과 GLR 관리도 Omnibus EWMA 관리도 그리고 Interval 관리도는 충분히 좋은 효율을 가짐을 알 수 있었다.

• Industrial Engineering and Management Systems
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• 제1권1호
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• pp.87-92
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• 2002

A stochastic process {$A_n$, n = 1, 2, ...} is an arithmetic process (AP) if there exists some real number, d, so that {$A_n$ + (n-1)d, n =1, 2, ...} is a renewal process (RP). AP is a stochastically monotonic process and can be used for modeling a point process, i.e. point events occurring in a haphazard way in time (or space), especially with a trend. For example, the vents may be failures arising from a deteriorating machine; and such a series of failures id distributed haphazardly along a time continuum. In this paper, we discuss estimation procedures for an AP, similar to those for a geometric process (GP) proposed by Lam (1992). Two statistics are suggested for testing whether a given process is an AP. If this is so, we can estimate the parameters d, ${\mu}_{A1}$ and ${\sigma}^{2}_{A1}$ of the AP based on the techniques of simple linear regression, where ${\mu}_{A1}$ and ${\sigma}^2_{A1}$ are the mean and variance of the first random variable $A_1$ respectively. In this paper, the procedures are, for the most part, discussed in reliability terminology. Of course, the methods are valid in any area of application, in which case they should be interpreted accordingly.

• 한국지능정보시스템학회:학술대회논문집
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• 한국지능정보시스템학회 2003년도 춘계학술대회
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• pp.338-346
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• 2003

Information Technology (IT) and the internet have been major drivers the changes in all aspects of the business processes and activities. They have brought major changes to the financial statements audit environment as well, which in turn has required modifications in audit procedures. There exist, however, certain difficulties with current audit procedures especially for the assessment of the level of control risk. This assessment is primarily based on the auditors' professional judgment and experiences, not based on the objective hies or criteria. To overcome these difficulties, this paper proposes a prototype decision support model named CRAS-CBR using case based reasoning (CBR) to support auditors in making their professional judgment on the assessment of the level of control risk of the general accounting system in the manufacturing industry. To validate the performance, we compare our proposed model with benchmark performances in terms of classification accuracy for the level of control risk. Our experimental results showed CRAS-CBR outperforms a statistical model (MDA) and staff auditor performance in average hit ratio.

• Earthquakes and Structures
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• 제10권1호
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• pp.239-260
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• 2016

Tuned mass dampers (TMDs) have been frequently proposed to mitigate the detrimental effects of dynamic loadings in structural systems. The effectiveness of this protection strategy has been demonstrated for wind-induced vibrations and, to some extent, for seismic loadings. Within this framework, recent numerical studies have shown that beneficial effects can be achieved by placing a linear TMD on the roof of linear elastic structural systems subjected to pulse-like ground motions. Motivated by these positive outcomes, closed-form design formulations have been also proposed to optimize the device's parameters. For structural systems that undergo a near-fault pulse-like ground motion, however, it is unlikely that their dynamic response be linear elastic. Hence, it is very important to understand whether such strategy is effective for inelastic structural systems. In order to provide new useful insights about this issue, the paper presents statistical results obtained from a numerical study conducted for three shear-type hysteretic (softening-type) systems having 4, 8 and 16 stories equipped with a linear elastic TMD. The effectiveness of two design procedures is discussed by examining the performances of the protected systems subjected to 124 natural pulse-like earthquakes.

• 응용통계연구
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• 제34권6호
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• pp.937-944
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• 2021

본 연구는 부분선형모형에서 변수선택의 문제를 다룬다. 부분선형모형은 평활화모수 추정과 같은 비모수 추정과 선형설명변수에 대한 추정의 문제를 함께 포함하고 있어 변수선택이 쉽지 않다. 본 연구에서는 빠른 전진선택법인 LARS 를 이용한 변수선택법을 제시한다. 제안된 방법은 LARS에 의하여 선별된 변수들에 대하여 t-검정, 가능한 모든 회귀모형 비교 또는 단계별 선택법을 적용한다. 제안된 방법들의 효율성을 비교하기 위하여 실제데이터에 적용한 예제와 모의실험 결과가 제시된다.

• PNF and Movement
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• 제12권2호
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• pp.51-61
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• 2014

Purpose: This study aimed to review articles related to PNF and easily provide information to readers who have difficulty reading papers or using PNF in clinics without a background in statistical knowledge. Methods: We used PubMed to collect papers on international studies and we conducted a search on April 28, 2014. Keywords used for the PubMed search were "PNF" and "Proprioceptive Neuromuscular Facilitation". The search results identified 765 papers that had been published since 1954. To target the papers for review, we selected 66 papers, excluding papers that were not published in online journals and papers that were written in a second language. Results: The reviewed papers consisted of studies that addressed basic principles and procedures, combined with other interventions, including PNF stretching concepts, and other diseases with PNF concepts. The articles related to basic procedures and principles reported on optimal contraction intensity, patterns, and irradiation. The articles related to stretching and strengthening reported on stretching the hamstring muscles in healthy subjects, in combination with other interventions such as neuromobilization, clinical massage, kinesio taping, and water immersion. The articles related to specific diseases reported on stroke, low back pain, athletic injury, total knee replacement, etc. Conclusion: In the 66 articles reviewed for this study, there was little evidence that PNF has therapeutic value. However, in future research on the application of PNF, investigators could conduct a more in-depth analysis of this topic and present more objective and useful information on the therapeutic benefits of PNF.

• Clinics in Shoulder and Elbow
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• 제25권1호
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• pp.42-48
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• 2022

Background: Total shoulder arthroplasty (TSA) has been demonstrated to be an effective treatment for multiple shoulder pathologies. The purpose of our study was to compare the relative value units (RVUs) per minute of surgical time for primary and revision TSA. Methods: The American College of Surgeons National Surgical Quality Improvement Program database was queried to identify patients that underwent primary TSA, one-component revision TSA, and two-component revision TSA between January 1, 2015 and December 31, 2017 using current procedure terminology codes. RVUs were divided by mean operative time for each procedure to determine the amount of revenue generated per minute. Rates were compared between the groups using a one-way analysis of variance with post-hoc Tukey test. Statistical significance was set at p<0.05. Results: When dividing compensation by surgical time, we found that two-component revision generated more compensation per minute compared to primary TSA (0.284±0.114 vs. 0.239±0.278 RVU per minute or $10.25±$4.11 vs. $8.64±$10.05 per minute, respectively; p=0.001). Conclusions: The relative value of revision TSA procedures is weighted to account for the increased technical challenges and time associated with these procedures. This study confirms that reimbursement is higher for revision TSA compared to primary TSA.

• Communications for Statistical Applications and Methods
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• 제19권1호
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• pp.47-55
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• 2012

식품의약품안전청에서는 제제간의 생물학적 동등성의 입증이 실패했을 경우 추가시험을 허용하는 시험 기준을 2008년 7월부터 시행하고 있다. 생물학적 동등성 시험의 추가시험규정은 원시험에서의 동등성 평가가 불충분한 시험 예수 때문에 실패했을 때 별도의 재시험 시험계획서를 제출하지 않고 피험자수를 증가시켜 다시 시험하여 제제간의 동등성을 평가할 수 있는 근거를 마련한 점에 긍정적이다. 하지만 최근 추가시험의 규정에 따라 군당 12명 이상의 피험자를 사용했을 경우 오히려 추가시험의 일관성 검정 규정을 만족하지 못하여 추가시험이 실패되는 경우가 자주 발생하고 있어 추가시험규정에 대한 불만이 고조되고 있다. 본 연구에서는 이러한 상황이 발생되는 통계적 원인을 살펴보고 현 기준을 일본 규정처럼 조금 더 일반화하게 되면 추가시험을 더 폭넓게 사용할 수 있는 것을 제안하고자 한다.

• 농촌의학ㆍ지역보건
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• 제23권1호
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• pp.51-64
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• 1998

This study was carried out during 3 years from March 1992 to March 1995, 140 healthy people and 140 C.V.A patients were investigated, at an oriental clinic in Taejon. The data collected was analysed using a SAS. The results are as follows. 1. The Relationships between patients who have undergone one or more abortion procedures and C.V.A occurrence. A statistical significant difference was recorded between the control group and the outpatients group of P<0.05 2. Number of years after initial C.V.A diagnosis before C.V.A symptom onset. within 1 years 52% (2-3 years, 3-4 years, 4-5 years, 5 years and over) 3. Additional diseases occurring after initial stroke 1 disease 50.7% (2, 3, 4, 5 or more) 4. Alcohol Consumption "A statistical significant difference was recorded between the control group and the outpatients group of" P<0.01 5. Previous Treatment Experience for stoke outpatients Oriental Hospital, clinic 64.3% (General Hospital, clinic, a public health center drug store, home remedies, etc) 6. Exercise Frequency Outpatients Regular 28.6%, Irregular 71.4% Control sample Regular 27%, Irregular 72.9% 7. Degree of Appetite "A statistical significant difference was recorded between the control group and the outpatients group of" P<0.01 8. People who include fish in their diet "A statistical difference was recorded between the control group and the outpatients group of" P<0.01.

• Communications for Statistical Applications and Methods
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• 제17권2호
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• pp.193-204
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• 2010

최근들어 공간적으로 분석을 필요로 하는 여러 분야에서의 연구자들은 공간통계학에 많은 관심을 가지게 되었다. 그리고 통계학 분야 역시 공간상에서 얻어진 데이터에 공간자기상관이 존재할 경우 공간적으로 분석해야 한다는 주장과 함께 많은 연구가 진행되고 있다. 공간통계학에서 다루고 있는 데이터 중에서 '공간 격자데이터 분석'은 (1) 공간이웃의 정의, (2) 공간이웃 가중치의 정의, (3) 공간모형의 적용 등의 단계를 거쳐서 행해진다. 본 연구에서는 이상치가 존재하는 공간 격자데이터를 분석할 경우 절사평균제곱오차를 이용하여 분석함으로써 예측적인 측면에서 공간통계학적 방법이 일반통계학적 방법보다 더 우수함을 보인다. 본 연구에 대한 내용의 타당성을 보이기 위해서 시뮬레이션을 통하여 공간통계학적인 방법과 일반통계학적인 방법을 비교하였다. 그리고 부산진구의 실제 범죄데이터를 이용한 적용사례를 통하여 절사평균제곱오차를 사용한 공간통계학적 방법의 유용성을 알아보았다.