• Journal of Chest Surgery
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• 제30권10호
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• pp.1015-1018
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• 1997

개심술 특히 판막 질환의 수술에 있어서 정중 흉부 절개의 방법은 현재까지 가장 널리 사용되는 절개 방 법이다 그러나 최근 들어 판막 질환의 수술시 우측 흉골외측 절개를 이용하여 절개부위를 최소화함으로서 많은 장점을 가질 수 있는 방법이 보고되고 있다. 고려대학교 부속 구로병원에서는 우측 흉골외측 절개와 심방 중격 절개를 이용하여 1례의 승모판막 치환 술을 시행하였는데, 이 방법의 사용시 기존의 정중 흉부 절개의 방법과 비교하여 특이한 합병증이나 어려움 을 경험할 수는 없었고,훌릉한 수술 시야를 확보할 수 있었으며,환자는 수술 절개 부위에 대하여 미용적인 면에서 매우 만족하였다.

• 한국측량학회지
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• 제29권1호
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• pp.63-69
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• 2011

대용량의 공간정보의 인터넷을 통한 활용이 활성화되면서 더 정확하고 풍부하며 최신의 정보를 가진 자료에 대한 사용자의 요구는 꾸준히 증가하고 있어 기 구축된 자료 간 융합을 통합 새로운 서비스 제공의 필요성이 커지고 있다. 이중에서 항공사진과 도로 벡터 자료를 융합한 서비스는 직관적이고 정확하게 정보를 전달 할 수 있어 많은 포털사이트에서 제공중인 서비스이나 자료 간 공간 불일치를 해결해야 한다. 본 연구에서는 도로 후보 영상 추출, 템플릿 매칭, 벡터 미디언 필터를 거쳐 자료 간 조정을 수행하였으며 완성도와 부합도로 정확도를 평가한 결과 원래 데이터에 비해 약 35% 향상되었음을 확인할 수 있었다.

• Earthquakes and Structures
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• 제3권3_4호
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• pp.581-609
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• 2012

In this paper a novel non-iterative approach is proposed to address the problem of deriving non-stationary stochastic processes which are compatible in the mean sense with a given (target) response (uniform hazard) spectrum (UHS) as commonly desired in the aseismic structural design regulated by contemporary codes of practice. This is accomplished by solving a standard over-determined minimization problem in conjunction with appropriate median peak factors. These factors are determined by a plethora of reported new Monte Carlo studies which on their own possess considerable stochastic dynamics merit. In the proposed approach, generation and treatment of samples of the processes individually on a deterministic basis is not required as is the case with the various approaches found in the literature addressing the herein considered task. The applicability and usefulness of the approach is demonstrated by furnishing extensive numerical data associated with the elastic design UHS of the current European (EC8) and the Chinese (GB 50011) aseismic code provisions. Purposely, simple and thus attractive from a practical viewpoint, uniformly modulated processes assuming either the Kanai-Tajimi (K-T) or the Clough-Penzien (C-P) spectral form are employed. The Monte Carlo studies yield damping and duration dependent median peak factor spectra, given in a polynomial form, associated with the first passage problem for UHS compatible K-T and C-P uniformly modulated stochastic processes. Hopefully, the herein derived stochastic processes and median peak factor spectra can be used to facilitate the aseismic design of structures regulated by contemporary code provisions in a Monte Carlo simulation-based or stochastic dynamics-based context of analysis.

• Communications for Statistical Applications and Methods
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• 제14권2호
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• pp.365-376
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• 2007

This research considers to propose the control charts using median for the location parameter. In order to decide the control limits, we apply several bootstrap methods through the approach obtaining the confidence interval except the standard bootstrap method. Then we illustrate our procedure using an example and compare the performance among the various bootstrap methods by obtaining the length between control limits through the simulation study. The standard bootstrap may be apt to yield shortest length while the bootstrap-t method, the longest one. Finally we comment briefly about some specific features as concluding remarks.

• Journal of information and communication convergence engineering
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• 제12권1호
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• pp.53-59
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• 2014

Motion estimation is a core part of most video compression systems since it directly affects the output video quality and the encoding time. The full search (FS) technique gives the highest visual quality but has the problem of a significant computational load. To solve this problem, we present in this paper a modified median (MMED) operation and advanced search strategies for fast motion estimation. The proposed MMED operation includes a temporally co-located motion vector (MV) to select an appropriate initial candidate. Moreover, we introduce a search procedure that reduces the number of thresholds and simplifies the early termination conditions for the determination of a final MV. The experimental results show that the proposed approach achieves substantial speedup compared with the conventional methods including the motion vector field adaptive search technique (MVFAST) and predictive MVFAST (PMVFAST). The proposed algorithm also improves the PSNR values by increasing the correlation between the MVs, compared with the FS method.

• Communications for Statistical Applications and Methods
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• 제13권2호
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• pp.233-241
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• 2006

Classical principal component analysis (PCA) can be formulated as finding the linear subspace that best accommodates multidimensional data points in the sense that the sum of squared residual distances is minimized. As alternatives to such LS (least squares) fitting approach, we produce LMS (least median of squares) and LTS (least trimmed squares)-type PCA by minimizing the median of squared residual distances and the trimmed sum of squares, in a similar fashion to Rousseeuw (1984)'s alternative approaches to LS linear regression. Proposed methods adopt the data-driven optimization algorithm of Croux and Ruiz-Gazen (1996, 2005) that is conceptually simple and computationally practical. Numerical examples are given.

• Journal of Chest Surgery
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• 제22권1호
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• pp.155-157
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• 1989

Median sternotomy is the incision of choice to allow access to the anterior mediastinum, heart, or both lungs. The vertical skin incision generally gives a poor cosmetic result. In certain patients particularly those who are asymptomatic and undergoing short, low risk procedures, cosmetic considerations are of relatively greater importance. A bilateral horizontal submammary skin incision with dissection of a flap including the subcutaneous tissue and breast allows exposure of the sternum so that a median sternotomy can be performed. We have performed this incision in 12 patients undergoing open heart surgery. Although obtaining the usual midsternal exposure takes some extra time, results have shown the va1ue of this approach and its benefit to the patients.

• Structural Engineering and Mechanics
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• 제83권5호
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• pp.577-591
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• 2022

This paper develops a comparatively time-efficient methodology for performing seismic fragility analysis of the reinforced concrete (RC) buildings in the presence of uncertainty sources. It aims to appraise the effectiveness of any variation in the material's mechanical properties as epistemic uncertainty, and the record-to-record variation as aleatory uncertainty in structural response. In this respect, the fuzzy set theory, a well-known 𝛼-cut approach, and the Genetic Algorithm (GA) assess the median of collapse fragility curves as a fuzzy response. GA is requisite for searching the maxima and minima of the objective function (median fragility herein) in each membership degree, 𝛼. As this is a complicated and time-consuming process, the authors propose utilizing the Gene Expression Programming-based (GEP-based) equation for reducing the computational analysis time of the case study building significantly. The results indicate that the proposed structural analysis algorithm on the derived GEP model is able to compute the fuzzy median fragility about 33.3% faster, with errors less than 1%.

• 상하수도학회지
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• 제28권5호
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• pp.561-571
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• 2014

The paper is to estimate willingness-to-pay (WTP) for tap water quality improvement in Busan, using parametric approach in contingent valuation method(CVM). For parametric approach linear logit model and log logit model are employed in double-bounded dichotomous choice format of CVM. For the reliability and the validity of contingent valuation method a survey was conducted for 665 respondents, who were sampled by stratified random sampling method, by personal interview method. The result of mean WTP for the tap water quality improvement in Busan was estimated to be 3,687 won and 3,660 won per month per household, while median WTP being 1,884 won and 1,892 won per month per household, respectively by linear logit model and log logit model. Provided that our sample is broadly representative of the Busan's population, an estimate of the annual aggregated benefit of residential water improvement for all Busan households is approximately 29.7 billion won to 29.8 billion won based on median WTP.

• Journal of Gastric Cancer
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• 제18권3호
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• pp.296-304
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• 2018

Purpose: This study aimed to examine the outcomes of cytoreductive surgery (CRS) and hyperthermic intraperitoneal chemotherapy (HIPEC) in patients with peritoneal metastasis (PM) of advanced gastric cancer (AGC). Materials and Methods: Between May 2015 and June 2017, 38 CRS and HIPEC procedures were performed in patients with PM of AGC at the Dankook University Hospital. We prospectively collected and analyzed data regarding PM grade, morbidity and mortality rates, and short-term follow-up results (median, 13.5 months). Results: The mean peritoneal cancer index was 15 (range, 0-39). Complete cytoreduction was achieved in 21 patients (55.2%), whereas complications occurred in 16 (42.1%) and 2 (5.7%) patients died. The overall median patient survival time was 19 months. The patients who underwent complete cytoreduction had a median survival time of 26 months, which was significantly longer than the median survival time of 16 months in the patients who did not undergo complete cytoreduction (P=0.006). Conclusions: CRS with HIPEC may have a beneficial effect in patients with PM of AGC. However, the rates of complications and mortality associated with this combined therapeutic approach are high. Therefore, this treatment should be performed only in selected patients by surgeons experienced in the field of gastric cancer with PM.