• 제목/요약/키워드: Diffuse Prior Information

검색결과 10건 처리시간 0.027초

단순 수명정보를 이용한 IPM의 베이지안 신뢰도 평가 연구 (A Study on Bayesian Reliability Evaluation of IPM using Simple Information)

  • 조동철;구정서
    • 한국안전학회지
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    • 제36권2호
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    • pp.32-38
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    • 2021
  • This paper suggests an approach to evaluate the reliability of an intelligent power module with information deficiency of prior distribution and the characteristics of censored data through Bayesian statistics. This approach used a prior distribution of Bayesian statistics using the lifetime information provided by the manufacturer and compared and evaluated diffuse prior (vague prior) distributions. To overcome the computational complexity of Bayesian posterior distribution, it was computed with Gibbs sampling in the Monte Carlo simulation method. As a result, the standard deviation of the prior distribution developed using simple information was smaller than that of the posterior distribution calculated with the diffuse prior. In addition, it showed excellent error characteristics on RMSE compared with the Kaplan-Meier method.

간접 확산 조명을 이용한 혼성반사 표면의 3차원 형상 취득 (Obtaining 3-dimensional shape of hybrid reflectance surfaces using indirect diffuse illumination)

  • 김태은;안호근;최종수
    • 한국통신학회논문지
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    • 제21권2호
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    • pp.301-312
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    • 1996
  • A new approach is presented for recovering the 3-D shape from shading image. Photometric Stereo Method (PSM) is generally based on the direct illumination. In this paper, the reflectance function is derived by introduceing the indirect diffuse illumination in PSM and then applied to hybrid reflectance model which consists fo two components; the Lambertian reflectance and the speclar reflectance. Under the hybrid reflectance model and the indirect diffuse illumination circumstances, the 3-D shape of object can be recovered from the suface normal vector extracted from the surface roughness, the surface reflectance ratio, and the intensity value of a pixel. This method is rapid because of using the reference table and simplifies the restriction condition about the reflectance function existing in prior studies. The recovery efficiency in our method is better than that in prior studies. Also, this method is applied to various types of surfaces by defining general reflectance function.

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혼성 반사면의 반사 특성 추출 및 형상 복구(II) (Shape recovery and extraction the reflection properties of hybrid reflectance surface(II))

  • 김태은;최종수
    • 전자공학회논문지S
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    • 제34S권6호
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    • pp.21-29
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    • 1997
  • In this paper, we propose a new approach for recovering 3-D shape and extracting the reflectance properties of surface from intensity images. Photometric stereo method(PSM) is genrally based on the direct illumination. In this paper, the reflectance function is derived by interoduceing the indirect diffuse illumination in PSM and then applied to hybrid reflectance model which consists of two components; the lambertian and the specular reflectance. Under the hybrid reflectance model and the indirect diffuse illumination circumstance, the reflectance properties of sample surface can be extracting by normal sampler and then 3-D shape of an object can be recovered based on extracting reflectance properties. This method is rapid because of using the reference table and simplifies the restriction condition about the reflectance function existing in prior studies. Th erecovery efficiency in our method is better than that in prior studies. Also, this method is applied to various types of surfaces by defining general reflectance function.

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Bayesian Estimation for the Multiple Regression with Censored Data : Mutivariate Normal Error Terms

  • Yoon, Yong-Hwa
    • Journal of the Korean Data and Information Science Society
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    • 제9권2호
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    • pp.165-172
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    • 1998
  • This paper considers a linear regression model with censored data where each error term follows a multivariate normal distribution. In this paper we consider the diffuse prior distribution for parameters of the linear regression model. With censored data we derive the full conditional densities for parameters of a multiple regression model in order to obtain the marginal posterior densities of the relevant parameters through the Gibbs Sampler, which was proposed by Geman and Geman(1984) and utilized by Gelfand and Smith(1990) with statistical viewpoint.

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잠재변수를 이용한 NHPP 베이지안 소프트웨어 신뢰성 모형에 관한 연구 (The NHPP Bayesian Software Reliability Model Using Latent Variables)

  • 김희철;신현철
    • 융합보안논문지
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    • 제6권3호
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    • pp.117-126
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    • 2006
  • 본 논문은 소프트웨어 신뢰성장 모형에 대한 베이지안 모수추론과 모형선택 방법이 연구되었다. 소프트웨어 성장 모형은 내재되어 있는 오류와 고장 간격시간으로 모형화하면 소프트웨어 개발 단계에서 유용하게 사용할 수 있다. 본 논문에서는 사후 분포의 정보를 얻기 위한 다중 적분문제에 있어서 일종의 마코브 체인 몬테칼로 방법인 깁스 샘플링을 사용하여 사후 분포의 계산이 이루어졌다. 확산 사전 분포를 가진 소프트웨어 신뢰성에 의존된 일반적 순서 통계량 모형에 대하여 베이지안 모수 추정이 이루어 졌고 효율적인 모형의 선택방법도 시행되었다. 모형 설정과 선택 판단기준은 편차 자승합을 이용한 적합도 검정과 추세 검정이 사용되었다. 본 논문에서 사용된 소프트웨어 고장 자료는 Minitab(version 14) 통계 페키지에 있는 와이블분포(형상모수가 2이고 척도모수가 5)에서 발생시킨 30개의 난수를 이용한 모의 실험자료를 이용하여 고장자료 분석을 시행하였다.

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Shallow Trench Isolation 공정에서 수분에 의한 nMOSFET의 Hump 특성 (Moisture Induced Hump Characteristics of Shallow Trench-Isolated nMOSFET)

  • 이영철
    • 한국정보통신학회논문지
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    • 제10권12호
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    • pp.2258-2263
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    • 2006
  • 본 논문은 shallow trench isolation (STI) 공정에서 ILD (inter-layer dielectric) 막의 수분에 의해 야기되는 단 채널 (short-channel) nMOSFET의 hump 특성의 원인을 분석하고 억제 방법을 제안하였다. 다양한 게이트를 가지는 소자와 TDS-APIMS(Thermal Desorption System-Atmospheric Pressure Ionization Mass Spectrometry) 측정을 이용하여 hump 특성을 체계적으로 분석하였고, 분석을 바탕으로 단 채널 hump모델을 제안하였다. 제안된 모델에 의한 단 채널 nMOSFET의 hump 현상은 poly-Si 게이트 위의 ILD 막의 수분이 상부의 SiN 막에 의해 밖으로 확산되지 못하고 게이트와 STI의 경계면으로 확산하여 발생한 것이 며, 이를 개선하기 위해 상부의 SiN 막의 증착 전 열공정을 통해 ILD 막의 수분을 효과적으로 배출시킴으로써 hump 특성을 성공적으로 억제하였다.

The change of QRS duration after pulmonary valve replacement in patients with repaired tetralogy of Fallot and pulmonary regurgitation

  • Yun, Yuni;Kim, Yeo Hyang;Kwon, Jung Eun
    • Clinical and Experimental Pediatrics
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    • 제61권11호
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    • pp.362-365
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    • 2018
  • Purpose: This study aimed to analyze changes in QRS duration and cardiothoracic ratio (CTR) following pulmonary valve replacement (PVR) in patients with tetralogy of Fallot (TOF). Methods: Children and adolescents who had previously undergone total repair for TOF (n=67; median age, 16 years) who required elective PVR for pulmonary regurgitation and/or right ventricular out tract obstruction were included in this study. The QRS duration and CTR were measured pre- and postoperatively and postoperative changes were evaluated. Results: Following PVR, the CTR significantly decreased (pre-PVR $57.2%{\pm}6.2%$, post-PVR $53.8%{\pm}5.5%$, P=0.002). The postoperative QRS duration showed a tendency to decrease (pre-PVR $162.7{\pm}26.4$ msec, post-PVR $156.4{\pm}24.4$ msec, P=0.124). QRS duration was greater than 180 msec in 6 patients prior to PVR. Of these, 5 patients showed a decrease in QRS duration following PVR; QRS duration was less than 180 msec in 2 patients, and QRS duration remained greater than 180 msec in 3 patients, including 2 patients with diffuse postoperative right ventricular outflow tract hypokinesis. Six patients had coexisting arrhythmias before PVR; 2 patients, atrial tachycardia; 3 patients, premature ventricular contraction; and 1 patient, premature atrial contraction. None of the patients presented with arrhythmia following PVR. Conclusion: The CTR and QRS duration reduced following PVR. However, QRS duration may not decrease below 180 msec after PVR, particularly in patients with right ventricular outflow tract hypokinesis. The CTR and ECG may provide additional clinical information on changes in right ventricular volume and/or pressure in these patients.

Application of Immunophenotyping and Heteroduplex Polymerase Chain Reaction (hPARR) for Diagnosis of Canine Lymphomas

  • Sirivisoot, Sirintra;Techangamsuwan, Somporn;Tangkawattana, Sirikachorn;Rungsipipat, Anudep
    • Asian Pacific Journal of Cancer Prevention
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    • 제17권6호
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    • pp.2909-2916
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    • 2016
  • Background: Canine malignant lymphoma is classified into B- or T-cell origin, as in the human case. Due to differences in prognosis, a suitable method needs to be developed for lineage identification. Aims: To determine the accuracy of immunophenotypic and molecular information between three methods: immunocytochemistry (ICC), immunohistochemistry (IHC) and heteroduplex polymerase chain reaction for antigen receptor rearrangements (hPARR) in spontaneous canine lymphomas. Materials and Methods: Peripheral blood, fine needle aspiration and tissue biopsies from enlarged peripheral lymph nodes prior to treatment of 28 multicentric lymphoma patients were collected. Cytopathology and histopathology were examined and classified using the updated Kiel and WHO classifications, respectively. Anti-Pax5 and anti-CD3 antibodies as B- and T-cell markers were applied for immunophenotyping by ICC and IHC. Neoplastic lymphocytes from lymph node and white blood cell pellets from peripheral blood were evaluated by hPARR. Results: In this study, low grade B-cell lymphoma accounted for 25% (7/28), high grade B-cell lymphoma for 64.3% (18/28) and high grade T-cell lymphoma for 10.7% (3/28). According to the WHO classification, 50% of all cases were classified as diffuse large B-cell lymphoma. In addition, ICC showed concordant results with IHC; all B-cell lymphomas showed Pax5+/CD3, and all T-cell lymphomas exhibited Pax5-/CD3+. In contrast to hPARR, 12 B-cell lymphomas featured the IgH gene; seven presented the $TCR{\gamma}$ gene; five cases showed both IgH and $TCR{\gamma}$ genes, and one case were indeterminate. Three T-cell lymphomas showed the $TCR{\gamma}$ gene. The percentage agreement between hPARR and ICC/IHC was 60%. Conclusions: Immunophenotyping should not rely on a single method. ICC or IHC with hPARR should be used concurrently for immunophenotypic diagnosis in canine lymphomas.

광주·전남지역 중소기업의 기 체결 FTA 활용성과와 학습지향성이 한·중·일 FTA 활용의지에 미치는 영향 (The Effects of Performance and Learning Orientation for the Existing FTA of SMEs in Gwangju and Jeonnam on the Using Intention of a Trilateral FTA among Korea, China and Japan)

  • 송윤아;강지원;이재은
    • 무역학회지
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    • 제41권5호
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    • pp.41-62
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    • 2016
  • 본 연구는 메가 FTA의 중요성이 증가하고 있는 오늘날의 통상환경 하에서 광주·전남지역 중소기업의 기 체결 FTA 활용성과와 FTA 학습지향성이 한·중·일 FTA 활용의지에 미치는 영향을 실증분석 하고 있다. 연구결과는 다음과 같다. 첫째, 기 체결 FTA 활용성과는 한·중·일 FTA 활용의지에 정(+)의 영향을 미치는 것으로 나타났다. 둘째, FTA 학습지향성은 한·중·일 FTA 활용의지에 정(+)의 영향을 미치는 것으로 나타났다. 향후 체결예정인 한·중·일 FTA의 활용의지에 영향을 미칠 수 있는 요인들을 실증분석하고 있다는 점에서 본 연구의 결과들은 향후 한·중·일 FTA 관련 정책 수립 시 의미 있고 유용한 실무적 시사점을 제시할 수 있을 것이다.

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Clinical Characteristics and Helicobacter pylori Status of Gastric Cancer in Thailand

  • Vilaichone, Ratha-Korn;Panarat, Wirat;Aekpongpaisit, Surasak;Mahachai, Voracha
    • Asian Pacific Journal of Cancer Prevention
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    • 제15권20호
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    • pp.9005-9008
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    • 2014
  • Background: Gastric cancer is the second leading course of cancer death worldwide and H. pylori infection is an important risk factor for gastric cancer development. This study was design to evaluate the clinical, pathological features, survival rate and prevalence of H. pylori infection in gastric cancer in Thailand. Materials and Methods: Clinical information, histological features, endoscopic findings and H. pylori status were collected from gastric cancer patients from Thammasat university hospital during June 1996-December 2011. H. pylori infection was assessed by histological evaluation, rapid urease test and serological test. Clinical information, endoscopic findings and histopathology of all patients were recorded and compared between patients with active or non-active H. pylori infection. Results: A total of 100 gastric cancer patients (55 men and 45 women with mean age of $55{\pm}16.8years$) were enrolled in this study. Common presenting symptoms were dyspepsia (74%), weight loss (66%), anemia (63%) and anorexia (38%). Mean duration of symptoms prior to diagnosis was 98 days. Overall prevalence of H. pylori infection was 83% and active H. pylori infection was 40%. 1-year and 5-year survival rates were 43% and 0%. There was no significant difference between active H. pylori infection in different locations (proximal vs non-proximal: 47.1% vs 48.5%; P-value = 0.9, OR=0.9; 95%CI=0.3-3.1) and histology of gastric cancer (diffuse type vs intestinal type: 47.4% vs 50%; P-value = 0.8, OR=0.9, 95%CI=0.3-2.7). However, linitis plastica was significantly more common in non-active than active H. pylori infection (27.9% vs 0%; P-value<0.0001, OR=13.3, 95%CI=3.2-64.5). Moreover, gastric cancer stage 4 was higher in non-active than active H. pylori infection (93% vs 50%, P-value<0.001). Conclusions: Prevalence of H. pylori infection in Thai gastric cancer patients was high but active infection was low. Most gastric cancer patients presented in advance stage and had a grave prognosis. Screening for gastric cancer in high risk individuals might be an appropriate tool for early detection and improve the treatment outcome for this particular disease in Thailand.