• 전자공학회논문지A
• /
• 제31A권6호
• /
• pp.209-221
• /
• 1994

Timers are commonly used in hardware design for time delays that are to be much longer than the system clock period. In this paper, we present a method by which we can synthesie a hardware containing timers that implement long time delays described in VHDL. Because, in general, timers require high hardware cost, they must be utilized as efficiently as possible. To solve this problem we define a graph model and propose an algorithm that uses the graph model to minimize number of timers. A preliminary experimental result show that the algorithm implements all required time delays using minimum number of timers.

• 대한산업공학회지
• /
• 제4권1호
• /
• pp.1-3
• /
• 1978

This paper presents a model for determining the optimal number of minimal repairs before replacement. The basic concept parallels the periodic replacement model with minimal repair at failure introduced by Barlow and Hunter, only difference being the replacement signalled by the number of previous minimal repairs performed on the unit. In the case of Weibull distribution, which is widely used as a general failure distribution, the optimal solution could be obtained numerically and seems more cost effective compared to the Barlow and Hunter's Policy II.

• Communications for Statistical Applications and Methods
• /
• 제3권2호
• /
• pp.151-159
• /
• 1996

The general formulas of average fraction inspected, average sample number and average outgoing quality in n-level skip-lot sampling plan are derived. Average sample number and average outgoing quality of a reference plan, three-level, five-level and ten-level skip-lot sampling plans are compared.

• 대한수학회보
• /
• 제56권6호
• /
• pp.1435-1445
• /
• 2019

We consider a checkpointing model for silent errors, where a checkpoint is taken every fixed number of verifications. Assuming generally distributed i.i.d. inter-occurrence times of errors, we derive the reliability of the model as a function of the number of verifications between two checkpoints and the duration of work interval between two verifications.

• Korean Journal of Mathematics
• /
• 제30권2호
• /
• pp.187-198
• /
• 2022

In this paper, we introduce a new concept in number theory called ζ-factors associated with a positive integer n. Applications of ζ-factors are in the arrangement of the defining polynomials in cyclic n-roots algebraic system and are thoroughly investigated. More precisely, ζ-factors arise in the proofs of vanishing theorems in regard to associated prime factors of the system. Exact computations through concrete examples of positive dimensions for n = 16, 18 support the results.

• 한국콘텐츠학회논문지
• /
• 제12권5호
• /
• pp.10-21
• /
• 2012

통합형셰이더 코어 구조 개발 이후 GPU는 그래픽스 전용 연산장치에서 범용 연산장치로 발달하고 있다. 특히, 병렬 응용 프로그램들은 병렬화된 하드웨어 구조를 효과적으로 활용할 수 있기 때문에, GPU를 활용하여 병렬 응용프로그램들을 실행시키는 기법이 주목을 받고 있다. 하지만, 현재의 GPU 구조는 비그래픽스 응용프로그램을 실행하는데 있어서 병렬성을 충분히 확보하지 못하다는 한계를 가지고 있기 때문에, 이를 해결하기 위해 GPU 구조는 빠르게 변화하고 있다. 본 논문에서는 GPU 구조의 개발 방향을 살펴보기 위해, 비그래픽스 병렬 응용프로그램들을 수행하는 경우에 코어 개수 및 동작 주파수 등의 하드웨어구조에 따른 GPU의 성능을 상세히 분석하고자 한다. 실험 결과, 코어 개수가 30에서 192로 늘어나고 동작주파수가 325MHz에서 450MHz로 증가함에 따라 GPU 성능은 28.9%에서 125.8%, 4.4%에서 16.2% 각각 향상되는 반면 성능 향상 효율성은 감소하는 것을 볼 수 있다. 성능 향상 효율성 감소의 주된 원인은 향상된 연산 능력에 맞추어 증가된 데이터 요구를 메모리가 적절하게 처리하지 못하기 때문이다. 결과적으로 GPU의 성능 향상 효율성을 더욱 높이기 위해서는 연산 능력 향상과 더불어 시스템 자원들 또한 GPU 구조에 맞게 변경되어야 함을 구체적인 실험을 통해 알 수 있다.

• Asian Pacific Journal of Cancer Prevention
• /
• 제15권14호
• /
• pp.5551-5556
• /
• 2014

Background: The prognostic value of human epidermal growth factor receptor-2 (HER-2/neu) for survival of patients with colorectal cancer (CRC) is still ambiguous. We therefore performed a meta-analysis to evaluate its prognostic significance. Materials and Methods: We searched the MEDLINE and EMBASE databases for published literature investigating associations between HER-2/neu status and overall survival of patients with CRC. A meta-analysis was performed using a DerSimonian-Laird model and publication bias was investigated by Begg's and Egger's tests. Subgroup analysis was also conducted according to the study design type, study quality score, cut-off value for HER-2/neu overexpression, publication region, patient number and publication year. Results: A total of 17 eligible studies involving 2,347 patients were identified for this meta-analysis. The combined hazard ratio (HR) was 1.31 (95% confidence interval (CI): 0.96-1.79), suggesting that HER-2/neu overexpression was not significantly associated with overall survival of patients with CRC. However, subgroup analysis revealed that HER-2/neu overexpression had an unfavorable impact on survival when the analysis was restricted to subgroups of study quality score ${\leq}5 $(HR=1.56, 95%CI: 1.17-2.10), Asian patients (HR=1.74, 95%CI: 1.22-2.49), patient number ${\leq}106$ (HR=1.57, 95%CI: 1.01-2.44), publication year before 2003 (HR=1.59, 95%CI: 1.02-2.49), and prospectively designed study (HR=3.62, 95%CI: 1.42-9.24). The effect disappeared in subgroups of study quality scores > 5 (HR=0.69, 95%CI: 0.33-1.44), non Asian patients (HR=1.14, 95%CI: 0.77-1.70), patients' number > 106 (HR=1.07, 95%CI: 0.67-1.72), publication year after 2003 (HR=1.13, 95%CI: 0.76-1.69), and retrospectively designed study (HR=1.22, 95%CI: 0.89-1.67). Conclusions: Our meta-analysis suggests that HER-2/neu overexpression might not be a significantly prognostic indicator for patients with CRC. Further studies are required to confirm these results.

• Journal of Cerebrovascular and Endovascular Neurosurgery
• /
• 제26권2호
• /
• pp.152-162
• /
• 2024

Objective: Stroke is the second-leading cause of death globally. Intracranial atherosclerotic stenosis (ICAS) represents 10-15% of ischemic strokes in Western countries and up to 47% in Asian countries. Patients with ICAS have an especially high risk of stroke recurrence. The aim of this meta-analysis is to reassess recurrent stroke, transient ischemic attack (TIA), and other outcomes with stenting versus best medical management for symptomatic ICAS. Methods: The search protocol was developed a priori according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. The OVID Medline, Embase, Web of Science, and Cochrane Library databases were searched from inception to August 14th, 2022. Results: This meta-analysis included four randomized controlled trials (RCTs), with a total number of 991 patients. The mean age of participants was 57 years. The total number of intracranial stenting patients was 495, and the number of medical treatment patients was 496. The included studies were published between 2011 and 2022. Two studies were conducted in the USA, and the other two in China. All included studies compared intracranial stenting to medical treatment for ICAS. Conclusions: In patients with ischemic stroke due to symptomatic severe intracranial atherosclerosis, the rate of 30-day ischemic stroke, 30-day intracerebral hemorrhage, one-year stroke in territory or mortality favored the medical treatment alone without intracranial stenting. The risk of same-territory stroke at last follow-up, disabling stroke at last follow-up, and mortality did not significantly favor either group. Intracranial stenting for atherosclerosis did not result in significant benefit over medical treatment.

• 보건행정학회지
• /
• 제28권2호
• /
• pp.138-144
• /
• 2018

Background: Diagnostic imaging fee had been reduced in May 2011, but it was recovered after 6 months because of strong opposition of medical providers. This study aimed to analyze the behavior of medical providers according to fee changes. Methods: The National Health Insurance claims data between November 2010 and December 2012 were used. The number of exams per computed tomography was analyzed to verify that the fee changes increased or decreased the number of exams. Multivariate regression model were applied. Results: The monthly number of exams increased by 92.5% after fee reduction, so the diagnostic imaging spending were remained before it. But medical provider decreased the number of exams after fee return. After adjusting characteristic of hospitals, fee reduction increased the monthly number of exams by 48.0% in a regression model. Regardless type of hospitals and severity of disease, the monthly number of exams increased during period of fee reduction. The number of exams in large-scaled hospitals (tertiary and general hospital) were increased more than those of small-scaled hospitals. Conclusion: Fee-reduction increased unnecessary diagnostic exams under the fee-for-service system. It is needed to define appropriate exam and change reimbursement system on the basis of guideline.

• Journal of Acupuncture Research
• /
• 제20권1호
• /
• pp.120-130
• /
• 2003

Objective: The purpose of this study is to compare the effects of Dong-si acupuncture therapy and General acupuncture therapy for the patients with acute ankle sprain. Methods : This study has been carried out for 60 cases of ankle sprain patients who have visited Dong-Seo Oriental medical Hospital from May 1, 2002 to September 30, 2002. We have treated 30 cases of them by Dong-si acupuncture therapy and the other 30 cases by General acupuncture therapy. And we have compared those two group. Results : 1. There was no significant difference at the treatment period and the number of treatment times in comparing two groups. 2. The number of treatment times for good effect is that : Dong-si took $1.57{\pm}0.85$ times and General acupuncture therapy took $2.15{\pm}0.96$ times. And we have found that the effect of Dong-si acupuncture therapy is faster than the other.