• Journal of the Korean Data and Information Science Society
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• 제15권3호
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• pp.633-644
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• 2004

Exponentially Weighted Moving Average(EWMA) control chart for variance-covariance matrix of several quality characteristics based on accumulate-combine approach has proposed. Numerical computations show that multivariate EWMA chart based on accumulate-combine approach is more efficient than corresponding multivariate EWMA chart based on combine-accumulate approach.

• 한국멀티미디어학회논문지
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• 제24권4호
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• pp.528-537
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• 2021

Face recognition has gained significant notice because of its application in many businesses: security, healthcare, and marketing. In this paper, we will present the recognition method using the combination of correlation filters (CF) and Support Vector Machine (SVM). Firstly, we evaluate the performance and compared four different correlation filters: minimum average correlation energy (MACE), maximum average correlation height (MACH), unconstrained minimum average correlation energy (UMACE), and optimal-tradeoff (OT). Secondly, we propose the machine learning approach by using the OT correlation filter for features extraction and SVM for classification. The numerical results on National Cheng Kung University (NCKU) and Pointing'04 face database show that the proposed method OT-SVM gets higher accuracy in face recognition compared to other machine learning methods. Our approach doesn't require graphics card to train the image. As a result, it could run well on a low hardware system like an embedded system.

• Communications for Statistical Applications and Methods
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• 제4권3호
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• pp.715-723
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• 1997

Multivariate control statistics to simultaneously monitor both means and variances for several quality variables under multivariate normal process are proposed. Performances of the proposed multivariate charts are evaluated in terms of average run length(ARL). Multivariate Shewhart chart is also proposed to compare the performances of multivariate exponentially weighted moving average(EWMA) charts. A numerical comparison shows that multivariate EWMA charts are more efficient than multivariate Shewhart chart for small and moderate shifts and multivariate EWMA scheme based on accumulate-combine approach is more efficient than corresponding multivariate EWMA chart based on combine-accumulate approach.

• 품질경영학회지
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• 제22권1호
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• pp.54-65
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• 1994

Multivariate exponentially weighted moving average (EWMA) control charts for monitoring the variance-covariance matrix are investigated. Two basic approaches, "combine-accumulate" approach and "accumulate-combine" approach, for using past sample information in the developement of multivariate EWMA control charts are considered. Multivariate EWMA control charts for monitoring the variance-covariance matrix are compared on the basis of their average run length (ARL) performances. The numerical results show that multivariate EWMA control charts based on the accumulate-combine approach are more efficient than corresponding multivariate EWMA control charts based on the combine-accumulate approach.

• 전기전자학회논문지
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• 제28권2호
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• pp.199-203
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• 2024

본 논문에서는 단일 프레임 지도 시간적 행동 지역화에서 1D 합성곱 층의 커널 사이즈 변화를 제안한다. 본 논문에서는 두 개의 1D 합성곱 층의 커널 사이즈를 각각 3과 1을 사용하는 기존 방법을 기반으로, 각각의 1D 합성곱 층의 커널 사이즈를 변화시키는 방법을 제안하였다. 제안하는 방법의 효율성을 검증하기 위하여 THUMOS'14 데이터셋을 활용하여 비교실험을 수행하였다. 또한 성능 평가를 위해 전체 비디오에 대한 분류 정확도(Accuracy), mAP(mean Average Precision) 그리고 Average mAP를 성능 지표로 사용하였다. 본 논문의 실험 결과에 따르면 제안하는 방법이 기존 방법보다 더 정확한 mAP와 Average mAP를 제공할 수 있음을 관찰하였다. 또한 커널 사이즈를 7과 1로 변화시킨 방법이 전체 비디오에 대한 분류 정확도에서 8.0% 개선된 것을 확인할 수 있었다.

• 대한족부족관절학회지
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• 제16권4호
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• pp.247-256
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• 2012

Purpose: This study was performed to evaluate the clinical outcomes of operative treatment using mini-open sinus tarsi approach for displaced intraarticular calcaneal fractures. Materials and Methods: We studied 18 cases (16 patients) of intraarticular calcaneal fractures who were treated with sinus tarsi approach by same surgeon. The mean age of patients was 44.8 years, and mean follow-up period was 17.2 months. The measurement of B$\ddot{o}$hler angle, Gissane angle, the degree of articular surface depression, and the period to union were performed through preoperative and postoperative radiographs. The clinical evaluation was performed according to hindfoot score of the American Orthopaedic Foot and Ankle Society (AOFAS) and scale of the Creighton-Nebraska health foundation (CNHF). Results: B$\ddot{o}$hler angle and Gissane angle had improved significantly from preoperative average $9.8^{\circ}$, $117.6^{\circ}$to average $22.4^{\circ}$, $113.4^{\circ}$ immediate postoperatively, and had maintained to average $21.8^{\circ}$and $114.2^{\circ}$ at the last follow-up. The degree of articular surface depression had improved significantly from preoperative average 5.2 mm to 1.2 mm at the last follow-up. All cases achieved bone union, and the period to union was average 10.5 weeks. AOFAS score was average 86.2 points at the last follow-up. There were 7 excellent, 9 good, and 2 fair results according to the CNHF scale. Therefore, 16 cases (88.8%) achieved satisfactory results. Conclusion: The minimally invasive sinus tarsi approach using headless compression screw seems to be an effective surgical method for displaced intraarticular calcaneal fractures, because of the possibility of accurate restoration of articular surface and the low risk of postoperative soft tissue complications.

• 한국대기환경학회지
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• 제32권5호
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• pp.513-525
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• 2016

To propose an effective ensemble methods in predicting $PM_{10}$ concentration, six experiments were designed by different ensemble average methods (e.g., non-weighted, single weighted, and cluster weighted methods). The single weighted method was calculated the weighted value using both multiple regression analysis and singular value decomposition and the cluster weighted method was estimated the weighted value based on temperature, relative humidity, and wind component using multiple regression analysis. The effects of ensemble average methods were significantly better in weighted average than non-weight. The results of ensemble experiments using weighted average methods were distinguished according to methods calculating the weighted value. The single weighted average method using multiple regression analysis showed the highest accuracy for hourly $PM_{10}$ concentration, and the cluster weighted average method based on relative humidity showed the highest accuracy for daily mean $PM_{10}$ concentration. However, the result of ensemble spread analysis showed better reliability in the single weighted average method than the cluster weighted average method based on relative humidity. Thus, the single weighted average method was the most effective method in this study case.

• Asian Journal of Atmospheric Environment
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• 제4권3호
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• pp.150-156
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• 2010

Inter-comparison of chemical transport models (CTMs) was conducted among four modeling research groups. Model performance of the ensemble approach to $O_3$ and $PM_{2.5}$ simulation was evaluated by using observational data with a time resolution of 1 or 6 hours at four sites in the Kanto area, Japan, in summer 2007. All groups applied the Community Multiscale Air Quality model. The ensemble average of the four CTMs reproduced well the temporal variation of $O_3$ (r=0.65-0.85) and the daily maximum $O_3$ concentration within a factor of 1.3. By contrast, it underestimated $PM_{2.5}$ concentrations by a factor of 1.4-2, and did not reproduce the $PM_{2.5}$ temporal variation at two suburban sites (r=~0.2). The ensemble average improved the simulation of ${SO_4}^{2-}$, ${NO_3}^-$, and ${NH_4}^+$, whose production pathways are well known. In particular, the ensemble approach effectively simulated ${NO_3}^-$, despite the large variability among CTMs (up to a factor of 10). However, the ensemble average did not improve the simulation of organic aerosols (OAs), underestimating their concentrations by a factor of 5. The contribution of OAs to $PM_{2.5}$ (36-39%) was large, so improvement of the OA simulation model is essential to improve the $PM_{2.5}$ simulation.

• 상하수도학회지
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• 제29권4호
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• pp.519-531
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• 2015

It has been widely accepted that the pressure management of water distribution systems using pressure reducing valves(PRVs) would be an effective method for controlling leakages. A pressure reducing valve (PRV) regulates outlet pressure regardless of fluctuating flow and varying inlet pressure, thereby reducing leakage and mitigating the stress on the water distribution system. However, the operation of a PRV is vulnerable to its mechanical condition and hydraulic operability. In this research, the effect of PRVs installed in water distribution system are evaluated in terms of hydraulic pressure reduction and mechanical performance by analyzing measured pressure data with statistical approach. A statistical approach using the moving average filter and frequency analysis based on fourier transform is presented to detect abnormally operated PRVs that have been densely installed in water distribution system. The result shows that the proposed approach can be a good performance evaluation method by simply measuring pressures for the PRVs.

• Clinics in Shoulder and Elbow
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• 제8권1호
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• pp.49-56
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• 2005

Purpose: To review the surgical results of stiff elbow using the posterior extensile approach which provides a wide surgical view with a single posterior skin incision. Materials and Methods: From February 1999 to May 2002, we performed 6 surgical correction of stiff elbow using posterior extensile approach and followed the patients more than 1 year. In order to get better result, we performed cadaver study (four elbows of two fresh cadavers). Average duration of follow up was 15.7 months $(14{\sim}21)$. Functional results was analyzed using Brobery and Morrey analysis scale. Results: The approach through the plane between the extensor carpi radialis longus and the extensor carpi radialis brevis was ideal, because it preserves normal anatomy and provides a wide surgical view of the anterior joint. The posterior joint could be approached directly between the medial head of the triceps brachii and brachialis medially, the lateral head of triceps brachii and brachioradialis laterally. In all patients, an improved ROM was obtained with intra and extra-articular adhesiolysis: an average $61.7^{\circ}$ improvement $(50{\sim}75)$. Functional results were as follows: five excellent, one good. In addition, the patients' satisfaction was high since the scar from the operation was only a single line at the posterior surface of the elbow. Conclusion: In the treatment of stiff elbow, posterior extensile approach is thought to be useful because this method provides wide anterior and posterior surgical view.