• Title/Summary/Keyword: Diffuse Prior Information

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

  • Jo, Dong Cheol;Koo, Jeong Seo
    • Journal of the Korean Society of Safety
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    • v.36 no.2
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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.

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

  • 김태은;안호근;최종수
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.21 no.2
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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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Shape recovery and extraction the reflection properties of hybrid reflectance surface(II) (혼성 반사면의 반사 특성 추출 및 형상 복구(II))

  • 김태은;최종수
    • Journal of the Korean Institute of Telematics and Electronics S
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    • v.34S no.6
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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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    • v.9 no.2
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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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The NHPP Bayesian Software Reliability Model Using Latent Variables (잠재변수를 이용한 NHPP 베이지안 소프트웨어 신뢰성 모형에 관한 연구)

  • Kim, Hee-Cheul;Shin, Hyun-Cheul
    • Convergence Security Journal
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    • v.6 no.3
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    • pp.117-126
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    • 2006
  • Bayesian inference and model selection method for software reliability growth models are studied. Software reliability growth models are used in testing stages of software development to model the error content and time intervals between software failures. In this paper, could avoid multiple integration using Gibbs sampling, which is a kind of Markov Chain Monte Carlo method to compute the posterior distribution. Bayesian inference for general order statistics models in software reliability with diffuse prior information and model selection method are studied. For model determination and selection, explored goodness of fit (the error sum of squares), trend tests. The methodology developed in this paper is exemplified with a software reliability random data set introduced by of Weibull distribution(shape 2 & scale 5) of Minitab (version 14) statistical package.

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

  • Lee, Young-Chul
    • Journal of the Korea Institute of Information and Communication Engineering
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    • v.10 no.12
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    • pp.2258-2263
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    • 2006
  • In this parer, hump characteristics of short-channel nMOSFETs induced by moistures of the ILD(inter-layer dielectric) layer in the shallow trench isolation (STI) process are investigated and the method for hump suppression is proposed Using nMOSFETs with various types of the gate and a measurement of TDS-APIMS (Thermal Desorption System-Atmospheric Pressure ionization Mass Spectrometry), hump characteristics were systematically analyzed and the systemic analysis based hump model was presented; the ILD layer over poly-Si gate of nMOSFET generates moistures, but they can't diffuse out of the SiN layer due to the upper SiN layer. Consequently, they diffuses into the edge between the gate and STI and induces short-channel hump. In order to eliminate moisture in the ILD layer by out-gassing method, the annealing process prior to the deposition of the SiN layer was carried out. As the result, short-channel humps of the nMOSFETs were successfully suppressed.

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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    • v.61 no.11
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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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    • v.17 no.6
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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.

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 (광주·전남지역 중소기업의 기 체결 FTA 활용성과와 학습지향성이 한·중·일 FTA 활용의지에 미치는 영향)

  • Song, Yun-Ah;Kang, Ji-Won;Lee, Jae-Eun
    • Korea Trade Review
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    • v.41 no.5
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    • pp.41-62
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    • 2016
  • This study made an analysis of the effects of performance and learning orientation for the existing FTA on the intention to use a trilateral FTA among Korea, China and Japan. The results of the empirical analysis of Small and Medium-sized Enterprises(SMEs) located in Gwangju and Jeonnam provinces are as follows. First, there is a positive correlation between the effects of performance for the existing FTA and intention of a trilateral FTA. This result suggests that SMEs' performance feedback can be used as an asset of corporate experience and will be helpful to increase the intention to use a trilateral FTA by contributing to have sustainable competitive advantage of companies. Secondly, there is a positive correlation between the SMEs' learning orientation about FTA and intention to use a trilateral FTA. This result indicates that SMEs have more learning orientation for FTA. They actively acquire and diffuse information. These activities can be helpful for having prior knowledge and absorptive capacity. In conclusion, this study is considered to provide useful theoretical and practical implications that can contribute to enhancing the using intention of a trilateral FTA by explaining the significance of performance feedback and learning orientation.

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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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    • v.15 no.20
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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.