• 국제학술발표논문집
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• The 5th International Conference on Construction Engineering and Project Management
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• pp.488-493
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• 2013

Accurate initial cost estimates are essential to effective management of construction projects where many decisions are made in the course of project management by referencing the estimates. In practice, the initial estimates are frequently derived from historical actual cost data, for which standard distribution-based techniques are widely applied in the construction industry to account for risk associated with the estimates. This approach assumes the same probability distribution of estimate errors for any selected estimates. This assumption, however, is not always satisfied. In order to account for the probabilistic nature of estimate errors, an alternative method for measuring the risk associated with a selected initial estimate is developed by applying the Bayesian probability approach. An application example include demonstrates how the method is implemented. A hypothesis test is conducted to reveal the robustness of the Bayesian probability model. The method is envisioned to effectively complement cost estimating methods that are currently in use by providing benefits as follows: (1) it effectively accounts for the probabilistic nature of errors in estimates; (2) it is easy to implement by using historical estimates and actual costs that are readily available in most construction companies; and (3) it minimizes subjective judgment by using quantitative data only.

• 한국음향학회지
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• 제31권6호
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• pp.410-418
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• 2012

파라메트릭 스테레오와 MPEG 서라운드는 대표적인 공간 오디오 부호화 기법이다. 본 논문에서는 기존의 공간 오디오 부호화 기법에서 채널간 상관도 합성의 문제점을 분석하였다. 기존의 방법에서는 출력신호에 합성되는 주요성분들은 서로 동위상 관계에 있는 반면 잔향성분들은 서로 반위상 관계에 있다고 가정하고 있다. 음수 채널간 상관도에 대해서 이러한 가정은 잔향성분을 과도하게 포함하도록 하는 문제점을 야기할 수 있다. 이에 대한 해결책으로 음수 채널간 상관도를 가지는 경우에 대해서는 주요성분들이 반위상 관계에 있다는 가정을 기반으로 새로운 채널간 상관도 합성 기법을 제안하였다. 제안된 기법은 실제 부호화 및 복호화기에서 동작하는 근사화 과정에도 적용되었다. 컴퓨터 시뮬레이션을 통하여 제안된 기법의 성능을 평가하였으며 주관적 청취 실험을 통하여 제안된 방법이 헤드폰 환경뿐만 아니라 스피커 환경에서도 효과적으로 동작함을 검증하였다.

• 생물정신의학
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• 제25권4호
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• pp.110-117
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• 2018

Objectives This study aimed to investigate the relationship between depressive and anxiety symptoms and tardive dyskinesia (TD) and reveal the association of cognitive function and TD in patients with schizophrenia. Methods We recruited 30 schizophrenia patients with TD and 31 without TD from a national mental hospital in South Korea. To assess depressive and anxiety symptoms, the Beck Depression Inventory-II (BDI-II) and the Beck Anxiety Inventory (BAI) were conducted. Using the five-factor structure of the BDI-II and BAI, somatic anxiety, cognitive depression, somatic depression, subjective anxiety, and autonomic anxiety were assessed. Computerized neurocognitive function test (CNT) was performed to assess levels of cognitive functions. We compared the clinical characteristics, levels of cognitive functions, and depressive and anxiety symptoms between schizophrenia patients with TD and without TD. Chi-square test, Fisher's exact test, independent t-test and Mann Whitney U test were conducted to compare two groups. Pearson correlation analysis was conducted to evaluate relationships among the abnormal involuntary movement scale (AIMS), BDI-II, BAI, somatic anxiety, cognitive depression, somatic depression, subjective anxiety, and autonomic anxiety. Results The subjects with TD had significantly lower score on the cognitive depression than those without TD (t = -2.087, p = 0.041). There were significant correlations between the AIMS score and the BDI-II score (r = -0.386, p = 0.035) and between the AIMS score and cognitive depression score (r = - 0.385, p = 0.035). Conclusions Our findings suggest the inverse relationship between severities in TD and depression and support the assumption that there is an inverse relationship between the pathophysiology of TD and depression.

• 품질경영학회지
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• 제39권1호
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• pp.34-44
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• 2011

In this research, the selection of rail tour items of importance and achievement of service quality will be different 'analysis under the assumption that the relationships between them, were studied. Through this research, managers' subjective judgments of the customer rather than by a judge, ie, the true value to our customers think of the rail service quality for tourism products is crucial to develop the important elements. In addition, market-oriented thinking is to present the basic data of the transition. To summarize the conclusions of this paper is as follows. First, what tourists are seeking, constant research and improvement of tourism services should be looking for ways. Secondly, the focus on service quality aspects of products and the urgent need to identify the side of part "Concentrate Here" and "Possible Overkill" by reducing the effort to improve the efficiency of management is considered to be accelerated. Finally, most point in terms of focus and means of transport for the tourism sector as well as the railway tourism products, using the railway as a tourism product now on tour items should be changed.

• 전자공학회논문지
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• 제50권12호
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• pp.184-190
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• 2013

파라메트릭 스테레오 오디오 부호화는 공간 오디오 기법 중 스테레오에 특화된 부호화 기법이다. 본 논문에서는 기존의 파라메트릭 스테레오 기법에서 채널간 위상차 합성시 발생하는 문제점을 분석하였다. 기존의 업믹스 행렬에서는 채널간 위상차를 다운믹스 신호뿐만 아니라 잔향신호에도 합성하고 이로 인하여 반위상 관계를 위반한다. 채널간 상관도가 낮을 때, 잔향 성분에 대한 채널간 위상차 합성으로 인하여 발생하는 음질열화를 분석하였다. 이러한 문제점들을 해결하기 위하여 신호 모델을 만족할 수 있도록 주요 성분에만 채널간 위상차를 합성하는 업믹스 행렬을 제안하였다. 주관적 음질 평가를 통하여 제안된 업믹스 행렬의 성능을 검증하였다.

• The Korean Journal of Pain
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• 제30권4호
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• pp.243-249
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• 2017

Pain is subjective, while statistics related to pain research are objective. This review was written to help researchers involved in pain research make statistical decisions. The main issues are related with the level of scales that are often used in pain research, the choice of statistical methods between parametric or nonparametric statistics, and problems which arise from repeated measurements. In the field of pain research, parametric statistics used to be applied in an erroneous way. This is closely related with the scales of data and repeated measurements. The level of scales includes nominal, ordinal, interval, and ratio scales. The level of scales affects the choice of statistics between parametric or non-parametric methods. In the field of pain research, the most frequently used pain assessment scale is the ordinal scale, which would include the visual analogue scale (VAS). There used to be another view, however, which considered the VAS to be an interval or ratio scale, so that the usage of parametric statistics would be accepted practically in some cases. Repeated measurements of the same subjects always complicates statistics. It means that measurements inevitably have correlations between each other, and would preclude the application of one-way ANOVA in which independence between the measurements is necessary. Repeated measures of ANOVA (RMANOVA), however, would permit the comparison between the correlated measurements as long as the condition of sphericity assumption is satisfied. Conclusively, parametric statistical methods should be used only when the assumptions of parametric statistics, such as normality and sphericity, are established.

• 의료법학
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• 제13권2호
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• pp.285-308
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• 2012

The Korean supreme court said that Mrs Kim who was in a persistent vegetative state had a right to die if she had a presumed will or assumption of dying against Severance hospital in 2009. Presumed would be vague and can not be subjective to conjecture though, the court had a developed trial on the case. I recommend the higher valued notion such as the 'right to decide on the life extension' is more logical than assumptive will. To achieve this recommendation, I will search right to life, right to decision, human dignity and find the good relationship between them. In conclusion, I will announce that if PVS patients without advanced directives aren't able to express their will and no one could not assume their right to die in spite of meaningless life extension. So only the due and strict procedure about the extinction of meaningless PVS patients will allow them to sacrifice themselves or remove life extension ventilators. Also active euthanasia would be possible under the strict procedure of making advanced directives and the act of helping active euthanasia additionally, the crime of abetting suicide would not be executed in the legal scope.

• 한국농공학회논문집
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• 제50권6호
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• pp.27-35
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• 2008

This study aims to estimate the optimal probability distribution of daily electricity generation by wind power, in order to contribute in rural green-village planning. Wind power generation is now being recognized as one of the most popular sources for renewable resources over the country. Although it is also being adapted to rural area for may reasons, it is important to estimate the magnitudes of power outputs with reliable statistical methodologies while applying historical daily wind data, for correct feasibility analysis. In this study, one of the well-known statistical methodology is employed to define the appropriate statistical distributions for monthly power outputs for specific rural areas. The results imply that the assumption of normal distributions for many cases may lead to incorrect decision-making and therefore lead to the unreliable feasibility analysis. Subjective methodology for testing goodness of fit for normal distributions on all the cases in this study, provides possibilities to consider the other various types of statistical distributions for more precise feasibility analysis.

• Nuclear Engineering and Technology
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• 제51권1호
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• pp.45-53
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• 2019

Thermal-hydraulic passive safety systems (PSSs) are incorporated into many advanced reactor designs on the bases of simplicity, economics and inherent safety nature. Several factors among which are the critical parameters (CPs) that influence failure and reliability of thermal-hydraulic (t-h) passive systems are now being explored. For simplicity, it is assumed in most reliability analyses that the CPs are independent whereas in practice this assumption is not always valid. There is need to critically examine the dependency influence of the CPs on reliability of the t-h passive systems at design stage and in operation to guarantee safety/better performance. In this paper, two multivariate analysis methods (covariance and conditional subjective probability density function) were presented and applied to a simple PSS. The methods followed a generalized procedure for evaluating t-h reliability based on dependency consideration. A passively water-cooled steam generator was used to demonstrate the dependency of the identified key CPs using the methods. The results obtained from the methods are in agreement and justified the need to consider the dependency of CPs in t-h reliability. For dependable t-h reliability, it is advisable to adopt all possible CPs and apply suitable multivariate method in dependency consideration of CPs among other factors.

• Journal of Audiology & Otology
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• 제23권1호
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• pp.1-7
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• 2019

Self-reported difficulties in speech-in-noise (SiN) recognition are common among tinnitus patients. Whereas hearing impairment that usually co-occurs with tinnitus can explain such difficulties, recent studies suggest that tinnitus patients with normal hearing sensitivity still show decreased SiN understanding, indicating that SiN difficulties cannot be solely attributed to changes in hearing sensitivity. In fact, cognitive control, which refers to a variety of top-down processes that human beings use to complete their daily tasks, has been shown to be critical for SiN recognition, as well as the key to understand cognitive inefficiencies caused by tinnitus. In this article, we review studies investigating the association between tinnitus and cognitive control using behavioral and brain imaging assessments, as well as those examining the effect of tinnitus on SiN recognition. In addition, three factors that can affect cognitive control in tinnitus patients, including hearing sensitivity, age, and severity of tinnitus, are discussed to elucidate the association among tinnitus, cognitive control, and SiN recognition. Although a possible central or cognitive involvement has always been postulated in the observed SiN impairments in tinnitus patients, there is as yet no direct evidence to underpin this assumption, as few studies have addressed both SiN performance and cognitive control in one tinnitus cohort. Future studies should aim at incorporating SiN tests with various subjective and objective methods that evaluate cognitive performance to better understand the relationship between SiN difficulties and cognitive control in tinnitus patients.