• Title/Summary/Keyword: median approach

Search Result 263, Processing Time 0.028 seconds

Mitral Valve Replacement by Minimally Invasive Right Parasternal Incision -A Case Report (우측 흉골외측 절개를 이용한 승모판막 치환술 -1례보고-)

  • 김학제;조원민
    • Journal of Chest Surgery
    • /
    • v.30 no.10
    • /
    • pp.1015-1018
    • /
    • 1997
  • Median sternotomy incision is world-widely used for open heart surgery, especially in valvular heart disease. But recently, minimally invasive approach by the right parasternal incision for valvular heart disease was introduced with the many merits by small incision. We experienced 1 case of mitral valve repalcement by right parasternal incision and extended transseptal approach. This technique has no specific compli ations or problems compared with the median sternotomy and was proven by the excellent exposure. Cosmetically, the patient was satisfied with the incision.

  • PDF

Vector Median Filter for Alignment with Road Vector Data to Aerial Image (항공사진과 도로 벡터 간의 Alignment를 위한 Vector Median Filter의 적용)

  • Yang, Sung-Chul;Yu, Ki-Yun
    • Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
    • /
    • v.29 no.1
    • /
    • pp.63-69
    • /
    • 2011
  • Recent growth of the geospatial information on the web made it possible to applicate spatial data. Also, the demand for rich and latest information shows a steady growth. The need for the new service using conflation of the existing spatial databases is on the increase. The information delivery of the services using the road vector and aerial image is reached intuitionally and accurately. However, the spatial inconsistencies in map services such as Daum map, Naver map and Google map is the problem. Our approach is processed to extract the road candidate image, match the template and filter the control points pair using vector median. Finally, CNS node and link are aligned to the real road with the aerial image. The experimental results show that our approach can align a set of CNS node and link with aerial imagery for daejon, such that the completeness and correctness of the aligned road have improved about 35% compare with the original roads.

Derivation of response spectrum compatible non-stationary stochastic processes relying on Monte Carlo-based peak factor estimation

  • Giaralis, Agathoklis;Spanos, Pol D.
    • Earthquakes and Structures
    • /
    • v.3 no.3_4
    • /
    • pp.581-609
    • /
    • 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.

Median Control Chart using the Bootstrap Method

  • Lim, Soo-Duck;Park, Hyo-Il;Cho, Joong-Jae
    • Communications for Statistical Applications and Methods
    • /
    • v.14 no.2
    • /
    • pp.365-376
    • /
    • 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.

Fast Motion Estimation Based on a Modified Median Operation for Efficient Video Compression

  • Kim, Jongho
    • Journal of information and communication convergence engineering
    • /
    • v.12 no.1
    • /
    • pp.53-59
    • /
    • 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.

LMS and LTS-type Alternatives to Classical Principal Component Analysis

  • Huh, Myung-Hoe;Lee, Yong-Goo
    • Communications for Statistical Applications and Methods
    • /
    • v.13 no.2
    • /
    • pp.233-241
    • /
    • 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.

Horizontal submammary skin incision for median sternotomy (유방하 피부 횡절개를 이용한 정중흉골 절개술)

  • 공현우
    • Journal of Chest Surgery
    • /
    • v.22 no.1
    • /
    • pp.155-157
    • /
    • 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.

  • PDF

An improvement on fuzzy seismic fragility analysis using gene expression programming

  • Ebrahimi, Elaheh;Abdollahzadeh, Gholamreza;Jahani, Ehsan
    • Structural Engineering and Mechanics
    • /
    • v.83 no.5
    • /
    • pp.577-591
    • /
    • 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%.

Estimating willingness-to-pay for the tap water quality improvement in Busan using contingent valuation method (조건부가치측정법을 이용한 부산시 상수도 수질개선에 대한 WTP 추정)

  • Pyo, Heedong;Choo, Jae Wook
    • Journal of Korean Society of Water and Wastewater
    • /
    • v.28 no.5
    • /
    • pp.561-571
    • /
    • 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.

Cytoreductive Surgery and Hyperthermic Intraperitoneal Chemotherapy as Treatment Options for Peritoneal Metastasis of Advanced Gastric Cancer

  • Kim, Dong-Wook;Park, Dong-Guk;Song, Sanghyun;Jee, Ye Seob
    • Journal of Gastric Cancer
    • /
    • v.18 no.3
    • /
    • pp.296-304
    • /
    • 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.