• Journal of Chest Surgery
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• v.27 no.8
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• pp.650-655
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• 1994

The author analyzed 99patients with VSD weighting less than 10kg of body weight who underwent surgical correction from 1981 to 1992 at cardiovascular department of Hanyang University hospital. Patients occupied 29.3% of total cases who were underwent surgical corrections for congenital heart diseases during that time. Of the 99 patients, 51 patients were male [52%] and 48 patients[48%] were female. Age ranged from 28 days to 36 months with mean age of 13.6 months. Mean body weight was 7.53kg. According to Kirklin`s anatomical classification, type II defect was most common [61.6%]. Associated anomaly was found in 48 patients [48.5%]. Patent foramen ovale was most commonly associated cardiac anomaly [14.1%] and followed by atrial septal defect [12.1%], patent ductus arteriosus [10.1%]. Cardiac catheterization data were analyzed. The most common range of Qp/Qs, Rp/Rs, Pp/Ps were above 3.0, 0.1 - 0.25, and above 0.75 respectively. Among the indications of surgical correction, there were pulmonary hypertention in 69 patients, congestive heart failure in 44 patients, frequent respiratory infection in 47 patients, growth retardation in 33 patients. The most common surgical approach and method for VSD closure were right atriotomy[48.3%] and dacron patch closure[93.3%]. Complication rate was 13.1% [13 cases], and overall mortality was 17.1% [17 cases]. The cause of death consisted of low cardiac output syndrome[11 cases], acute renal failure[3 cases], sepsis[2 cases] and pulmonary insufficiency[1 case] in order of frequency.

• Asian Pacific Journal of Cancer Prevention
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• v.15 no.8
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• pp.3567-3570
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• 2014

Background: Hepatocellular carcinoma (HCC) is one of the most common cancers in men and the third most common cancer in woman in Thailand. This retrospective study was designed to assess the prevalence, clinical manifestations, treatment outcomes and prognosis of HCC in the central region of Thailand. Materials and Methods: The authors retrospectively reviewed all HCC patients aged more than 15 years old in Thammasat university hospital (TUH) during the period from January 2007 to December 2012. Clinical information, biochemical tests and radiologic findings were collected from review of medical records. Results: There were 308 patients with HCC, which accounted for the prevalence of 5.19% of all cancers diagnosed in TUH during the study period. Of these, 125 (40.5%) had complete information retrievable from their medical records and met the inclusion criteria, 99 (79.2%) were males. The mean age was 57.4 years. A quarter of HCC patients in this study presented without any symptom before diagnosis. The common clinical presentations in the remaining patients were hepatomegaly 64/125 (51.2%), abdominal pain 56/125 (44.8%) and ascites 16/125 (20.8%). Cirrhosis was seen in almost all patients (92.8%). The most common causes of HCC in this study were chronic hepatitis B (49.6%) and C (19.2%). Based on Barcelona Clinic Liver Cancer staging, 75.4% presented at intermediate or late stage. Patients receiving curative therapy with either surgical treatment or radiofrequency ablation had significantly longer survival time after the HCC diagnosis than the palliative therapy group (11.0 months vs 4.0 months, p value= 0.004). The mean survival time after the HCC diagnosis was 10.5 months. Conclusions: The common causes of HCC in central region of Thailand were chronic hepatitis B and C. Surgical therapy or RFA seemed to provide better outcomes than other treatments but only in patients with early stage lesions. Most of the patients in this study presented with advanced diseases and had grave prognosis. Appropriate screening patients at risk for HCC might be an appropriate way to achieve early diagnosis and improve the treatment outcome.

• Journal of the Korean Data and Information Science Society
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• v.15 no.1
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• pp.59-74
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• 2004

The paper considers the Bayesian interval estimation for the common mean of several normal populations. A Bayesian procedure is proposed based on the idea of matching asymptotically the coverage probabilities of Bayesian credible intervals with their frequentist counterparts. Several frequentist procedures based on pivots and P-values are introduced and compared with Bayesian procedure through simulation study. Both simulation results demonstrate that the Bayesian procedure performs as well or better than any available frequentist procedure even from a frequentist perspective.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.31 no.4
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• pp.1-9
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• 2008

JIT 생산시스템이 세계적으로 많은 회사에 적용됨에 따라 earliness와 tardiness의 페널티를 동시에 최소화하는 문제에 대한 많은 연구가 진행되어 왔다. 이 연구에서는 한정된 완료시간의 편차에 대해서는 페널티를 부과하지 않는, 즉 허용오차가 존재할 때, 공통의 납기로부터 평균제곱편차(MSD : Mean Squared Deviation)를 최소화하는 단일기계 문제를 다룬다. 허용오차가 존재하는 MSD 문제에서 최적의 공통 납기를 결정하는 방법을 개발한다. 스케줄과 허용 오차가 주어질 때, 최적의 납기를 찾는 두 개의 선형시간이 소요되는 알고리즘을 제시한다. 주어진 허용오차 중 하나는 가장 짧은 가공시간을 가지는 작업의 절반보다 작은 경우이며 다른 하나는 허용오차가 임의인 경우이다.

• Transactions of the Korean Society of Automotive Engineers
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• v.14 no.1
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• pp.17-24
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• 2006

This study was performed to figure out spray behavior and fuel atomization characteristics of a piezo-driven injector and a solenoid-driven injector in the common-rail injection system under the same design parameters and test conditions. The process of spray injection was visualized by using the spray visualization system composed of a Nd:YAG laser and an ICCD camera. The atomization characteristics were investigated in terms of axial mean velocity, Sauter mean diameter(SMD) and droplet distributions obtained from a phase Doppler particle analyzer system. Compared with solenoid-driven injector, the piezo-driven injector has short injection delay and reaches quickly to the maximum injection value. Spray tip penetration shows some difference, however, spray angle of piezo-driven injector is wider than that of solenoid-driven injector. Sauter mean diameter of piezo-driven type injector is smaller than that of solenoid-driven type.

• Clinical Endoscopy
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• v.56 no.6
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• pp.754-760
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• 2023

Background/Aims: Endoscopic vacuum therapy (EVT) can heal a variety of defects within the gastrointestinal (GI) tract via applying negative pressure, which reduces the defect size, aspirates the infected fluid, and promotes granulation tissue. Here we present our experience with EVT as it relates to both spontaneous and iatrogenic upper GI tract perforations, leaks, and fistulas. Methods: This retrospective study was conducted at four large hospital centers. All patients who underwent EVT between June 2018 and March 2021 were included. Data on multiple variables were collected, including demographics, defect size and location, number and intervals of EVT exchanges, technical success, and hospital length of stay. Student t-test and the chi-squared test were used to analyze the data. Results: Twenty patients underwent EVT. The most common defect cause was spontaneous esophageal perforation (50%). The most common defect location was the distal esophagus (55%). The success rate was 80%. Seven patients were treated with EVT as the primary closure method. The mean number of exchanges was five with a mean interval of 4.3 days between exchanges. The mean length of hospital stay was 55.8 days. Conclusions: EVT is a safe and effective initial management option for esophageal leaks and perforations.

• Communications for Statistical Applications and Methods
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• v.15 no.2
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• pp.255-264
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• 2008

It is common in practice to use mean squared error(MSE) for prediction. Recently, Park and Shin (2005) and Jones et al. (2007) studied prediction based on mean squared relative error(MSRE). We proposed a new nonparametric way of prediction based on MSRE substituting Jones et al. (2007) and provided a small simulation study which highly supports the proposed method.

• Journal of ILASS-Korea
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• v.12 no.2
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• pp.108-114
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• 2007

This study investigates the influence of energizing duration on the fuel atomization characteristics of biodiesel injected through a high pressure common-rail injector. In order to analyze the effect of energizing duration on the fuel injection rate performance, the injection rate of biodiesel fuel is obtained from the pressure variation in the tube filled with fuel in injection measuring system. On the other hand, the atomization characteristics of biodiesel was measured and compared in terms of Sauter mean diameter(SMD), arithmetic mean diameter(AMD), droplet mean velocity, and detected droplets number by applying a phase Doppler particle analyzer(PDPA). It was revealed that the injection mass and maximum injection rate increase with increase of the energizing duration. Moreover, the increase of energizing duration improves the atomization performance of biodiesel fuel because it induces higher droplets momentum and velocity.

• Journal of the Korean Operations Research and Management Science Society
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• v.17 no.3
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• pp.181-193
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• 1992

This paper shows the model of a consecutive-k-out-of-n :G system with common-cause outages. The objective is to analytically derive the mean operating time between failures for a non-repairable component system. The average failure time of a system and the system availability are also considered. Then, the model is extended to a system with repairable components and unrestricted repair, in which service times are exponentially distributed.

• The Korean Journal of Applied Statistics
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• v.3 no.2
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• pp.79-89
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• 1990

For selecting a subset of k normal populations containing the one with the largest mean, a Bayes-$P^*$ selection procedure is considered when the common variance is unknown. Performance of the Bayes-$P^*$ selection procedure is compared with a well known classical procedure through a simulation study. Some frequentist's characteristics of Bayes-$P^*$ procedure are also studied.