• Nuclear Engineering and Technology
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• 제45권1호
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• pp.81-88
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• 2013

Neutron spectrum analyses of spallation neutrons are conducted in the accelerator-driven system (ADS) facility at the Kyoto University Critical Assembly (KUCA). High-energy protons (100 MeV) obtained from the fixed field alternating gradient accelerator are injected onto a tungsten target, whereby the spallation neutrons are generated. For neutronic characteristics of spallation neutrons, the reaction rates and the continuous energy distribution of spallation neutrons are measured by the foil activation method and by an organic liquid scintillator, respectively. Numerical calculations are executed by MCNPX with JENDL/HE-2007 and ENDF/B-VI libraries to evaluate the reaction rates of activation foils (bismuth and indium) set at the target and the continuous energy distribution of spallation neutrons set in front of the target. For the reaction rates by the foil activation method, the C/E values between the experiments and the calculations are found around a relative difference of 10%, except for some reactions. For continuous energy distribution by the organic liquid scintillator, the spallation neutrons are observed up to 45 MeV. From these results, the neutron spectrum information on the spallation neutrons generated at the target are attained successfully in injecting 100 MeV protons onto the tungsten target.

• Journal of the Korean Data Analysis Society
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• 제20권6호
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• pp.2829-2840
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• 2018

음이 아닌(non-negative) 측정값을 가지는 확률변수에 있어서, 영(0)이 과도하게 측정되는 자료를 반연속형(semi-continuous) 자료와 영-과잉(zero-inflated) 자료로 구분한다. 이러한 자료에서는 특정 확률 분포(probability distribution) 하에서의 확률보다 훨씬 큰 확률로 0을 관측하게 되는데, 연속형(continuous) 확률분포를 고려하는 경우에는 반연속형으로, 이산형(discrete) 확률분포를 고려하는 경우에는 영-과잉이라고 한다. 본 연구에서는 경계값(0)의 측정 여부에 관한 모형과 0보다 큰 확률변수에 대한 확률분포를 활용한 모형 등 두 개의 부문으로 이루어진 모형, 즉 2-부문 모형(two-part model)을 소개하고자 한다. 특히, 이산형 확률분포 중 포아송 분포와 음이항 분포를 고려한 영-과잉 회귀모형(regression model)을 설명하고 그 특성을 파악하고자 한다. 실증연구에서는 이러한 영-과잉 회귀모형을 활용하여 지난 10년(2009년부터 2018년) 간 한국의 여름철(6-8월) 폭염주의보(heat-wave advisory) 및 폭염경보(heat-wave warning) 발생일수를 적합하였다. 또한 공간예측기법 중 하나인 범용크리깅(universal kriging)을 이용하여 적합결과를 바탕으로 한 폭염 발생일수에 대한 예측지도를 작성하였다.

• 한국결정성장학회:학술대회논문집
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• 한국결정성장학회 1997년도 Proceedings of the 13th KACG Technical Meeting `97 Industrial Crystallization Symposium(ICS)-Doosan Resort, Chunchon, October 30-31, 1997
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• pp.117-121
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• 1997

It is shown theoretically that uniform axial dopant concentration distribution can be made throughout the crystal by continuous Czochralski process. Numerical simulation are performed for the transient two-dimensional convection-diffusion model. A typical value of the growth and system parameters for Czochralski growth of p-type, 4 inches silicon crystal was used in the numerical calculations. Using this model with proper model parameter, the axial segregation in batchwise Czochralski growth can be described. It is studied by comparing with the experimental data. With this model parameter, the uniform axial concentration distribution of dopant is predicted in continuous Czochralski process.

• 대한산업공학회지
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• 제41권1호
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• pp.10-16
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• 2015

In this study, we suggest a method to predict probability distribution of a new customer's degree of loyalty using C-CRF that reflects the RFM score and similarity to the neighbors of the customer. An RFM score prediction model is introduced to construct the first feature function of C-CRF. Integrating demographical similarity, purchasing characteristic similarity and purchase history similarity, we make a unified similarity variable to configure the second feature function of C-CRF. Then parameters of each feature function are estimated and we train our C-CRF model by training data set and suggest a probabilistic distribution to estimate a new customer's degree of loyalty. An example is provided to illustrate our model.

• 산경연구논집
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• 제6권3호
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• pp.5-8
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• 2015

Purpose - This article's aim is to examine how the utilization of existing and future decision-support systems will lead to a change in the auditing process. Research design, data, and methodology - An information system is a special decision-support system that combines information obtained from various sources and communicates among them to help in assessing appropriate complex financial decisions. This paper analyzes techniques such as data and text mining as components of decision-support systems to be used in the auditing process. Results - We present views about how existing decision-support systems will lead to a change in audits. Auditors, who currently collect significant data manually, will in the future move towards management through complex decision-support systems. Conclusions - Although some internal audit functions are integrated into systems of continuous monitoring, the use of such systems remains limited. Thus, instead of multiple decision-support systems, a unified decision-support system can be deployed for this that includes sensors integrated within a company in different contexts (e.g., production, sales, and accounting) that continually monitors violations of controls, unusual patterns, and unusual transactions.

• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 2000년도 가을 학술발표회 논문집(II)
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• pp.929-932
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• 2000

In this paper, physical properties of fresh and hardened mortar for floor using expansion agent are described under various grain shape, grading and chloride contents of aggregates. According to experimental results, as fineness modulous increase, fluidity show high it also shows high with cement mortar using riversand and continuous distribution of grading. We can not detect any difference in fluidity according to chloride contents. Air content shows to be decreased with crushed stone having large fineness modulous and continuous distribute on of grading. chloride content does not influence on the air content. compressive strength tends to increase when crushed sand with continuous distribution of grading is used and chloride contents decreases.

• Computers and Concrete
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• 제5권4호
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• pp.375-388
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• 2008

Crack opening governs many transfer properties that play a pivotal role in durability analyses. Instead of trying to combine continuum and discrete models in computational analyses, it would be attractive to derive from the continuum approach an estimate of crack opening, without considering the explicit description of a discontinuous displacement field in the computational model. This is the prime objective of this contribution. The derivation is based on the comparison between two continuous variables: the distribution if the effective non local strain that controls damage and an analytical distribution of the effective non local variable that derives from a strong discontinuity analysis. Close to complete failure, these distributions should be very close to each other. Their comparison provides two quantities: the displacement jump across the crack [U] and the distance between the two profiles. This distance is an error indicator defining how close the damage distribution is from that corresponding to a crack surrounded by a fracture process zone. It may subsequently serve in continuous/discrete models in order to define the threshold below which the continuum approach is close enough to the discrete one in order to switch descriptions. The estimation of the crack opening is illustrated on a one-dimensional example and the error between the profiles issued from discontinuous and FE analyses is found to be of a few percents close to complete failure.

• Asian Journal of Business Environment
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• 제4권3호
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• pp.19-25
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• 2014

Purpose - This study investigated not only social network service (SNS) characteristics' effects on continuous use intention and reliability, but also the effects of continuous use intention and reliability on purchase intention. Research design, data, and methodology - The subjects comprised 274 SNS users in their twenties. The research was conducted over three weeks from October 16, 2013 to November 6, 2013, using questionnaires. A total of 267 copies were collected; 255 copies were used after excluding unsuitable copies. Results - Marketers who used SNSs should establish a bi-directional community and SNS page information exchange. SNS marketers should exchange useful information quickly through SNS pages, to differentiate themselves from competitors. Enterprises should use SNSs for marketing, considering not only continuous use intention but also reliability, to elevate product purchase intention. Conclusions - The study had limitations. Most subjects were students aged 24 to 28 years; the findings cannot be generalized. Second, personal computers (PCs) and smartphones had similar influence. Third, the preferences and/or characteristics of each SNS type were not reflected in marketing.

• 한국분말야금학회:학술대회논문집
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• 한국분말야금학회 2006년도 Extended Abstracts of 2006 POWDER METALLURGY World Congress Part 1
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• pp.162-162
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• 2006

• 대한수학회논문집
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• 제25권3호
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• pp.485-489
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• 2010

A family of continuous probability distribution has been characterized through the difference of two conditional expectations, conditioned on a non-adjacent record statistic. Also, a result based on the unconditional expectation and a conditional expectation is used to characterize a family of distributions. Further, some of its deductions are also discussed.