• 대한토목학회논문집
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• 제5권4호
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• pp.57-64
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• 1985

유출 특성이 정상이라는 가정하에 침투능식의 매개 변수들을 추정하기 위해 다음의 절차를 고안하였다 : (1) 최적화기법에 의하여 유출모형의 제 매개변수를 추정한다. (2) 추정된 매개 변수들이 정상이라는 가정하의 기간 동안에 발생한 호우들에 대해 적합성을 보이도록 유효우량을 제어한다. (3) (1)~(2)의 절차를 반복하여 모든 매개 변수들이 평형상태에이르면 최적 제어된 손실우량을 수식으로 표현하기 위하여 비선형 fitting 을 적용한다. 이때 손실우량은 강우심도를 반영하도록 한다. 횡성 유역의 연속된 3개의 호우에 대해 위 기법을 적용한 결과, 선정된 얼개와 고안된 절차는 관측치에 충분한 적합성을 보였고 과거 연구와도 비교하였다.

• 한국안전학회지
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• 제35권3호
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• pp.86-95
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• 2020

This paper describes the work and the results of the final Probabilistic Safety Assessment (PSA) for the Jordan Research and Training Reactor (JRTR). This final PSA was undertaken to assess the level of safety for the design of a research reactor and to evaluate whether it is probabilistically safe to operate and reliable to use. The scope of the PSA described here is a Level 1 PSA, which addresses the risks associated with core damage. After reviewing the documents and its conceptual design, nine typical initiating events were selected regarding internal events during the normal operation of the reactor. AIMS-PSA (Version 1.2c) was used for the accident quantification, and FTREX was used as the quantification engine. 1.0E-15/yr of the cutoff value was used to deliminate the non-effective Minimal Cut Sets (MCSs) when quantifying the JRTR PSA model. As a result, the final result indicates a point estimate of 2.02E-07/yr for the overall Core Damage Frequency (CDF) attributable to internal initiating events in the core damage state for the JRTR. A Loss of Primary Cooling System Flow (LOPCS) is the dominant contributor to the total CDF by a single initiating event (9.96E-08/yr), and provides 49.4% of the CDF. General Transients (GTRNs) are the second largest contributor, and provide 32.9% (6.65E-08/yr) of the CDF.

• 한국지하수토양환경학회:학술대회논문집
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• 한국지하수토양환경학회 2002년도 총회 및 춘계학술발표회
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• pp.159-162
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• 2002

Innovative and nondestructive characterization techniques have been developed to locate and quantify nonaqueous phase liquids (NAPLs) in the vadose and saturated zones in the subsurface environment. One such technique is the partitioning interwell tracer test (PITT). The PITT is a simultaneous displacement of partitioning and non-partitioning tracers through a subsurface formation. Partitioning tracers will partition into the NAPL during their transport through NAPL-contaminated formations. Mean travel times of partitioning and non-partitioning tracers are used to estimate the quantity of NAPL encountered by the displaced tracer pulse. Travel times are directly proportional to the partitioning coefficient and the volume of NAPL contacted in the subsurface environment. This paper discusses the conceptual background, design and implementation of PITTs. (This document has not been subjected to Agency review and therefore does not necessarily reflect the views of the Agency, and no official endorsement should be inferred.)

• 산업공학
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• 제16권4호
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• pp.450-462
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• 2003

In this paper, we deal with a process and layout design for producing a planned amount of Sikhye in a given limited time period under a reasonable production schedule. We represent a Sikhye production line as a vector N, the element of which denotes the number of tanks required in each process and our objective is to find an appropriate vector which minimizes the total investment cost. We suggest a systematic method for finding an appropriate N and an appropriate layout to N. In detail, first, we decide the required sequence of processes and the required operations for each process and we estimate standard operating times. Second, constructing a precedence diagram, we find a critical path in order to reduce the total production lead time for a batch of Sikhye. Third, given a limited N space, we manage to construct manually each production schedule using both the processing times of the critical operations and transfer times. Finally, we find an optimal vector N which gives a minimum investment cost and meets both the time constraint and quantity constraint. In addition, with the estimated relative size of each tank, we suggest an appropriate conceptual layout design including an expansion area for future demands, based on the span technique used in the field of architectural design.

• 한국환경과학회지
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• 제10권3호
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• pp.217-223
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• 2001

Where no records are available at a site, a preliminary estimate may be made from relations between floods and catchment chatacteristics. A number of these chatacteristics were chosen for testing and were measured for those catchments where mean annual flood estimates were available. Although the improvement using extended data in regression of flood estimates on catchment characteristics was small, this may be due to the limitations of the regression model. When an individual short term record is to be extended, more detailed attention can be given; an example is presented of the technique which should be adopted in practice, particularly when a short term record covers a period which is known to be biassed. A method of extending the peaks over a threshold series is presented with a numerical example. The extension of records directly from rainfall by means of a conceptual model is discussed, although the application of such methods is likely to be limited by lack of recording raingauge information. Methods of combining information from various sources are discussed in terms of information from catchment characteristics supplemented by records. but are generally applicable to different sources of information. The application of this technique to estimating the probable maximum flood requires more conservative assumptions about the antecedent condition, storm profile and unit hydrograph. It is suggested that the profile and catchment wetness index at the start of the design duration should be based on the assumption that the estimated maximum rainfall occurs in all durations centered on the storm peak.

• 한국환경과학회지
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• 제20권6호
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• pp.789-798
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• 2011

Climate change assessment, together with climate change adaptation process, would be one of the worldwide important issues, and the study on climate change vulnerability indicator has been an essential problem for climate change adaptation. Vulnerability indicator can be used as a good tool to estimate the impact of climate change and to map out the distribution of its vulnerability over the given area both in Korea and other countries. This study addressed the conceptual summary on the assessment of climate change and its adaptation process. Previous studies on how to yield the vulnerability indicators of climate change are reviewed and several previous results of vulnerability indicators applied to Korean provinces are also discussed here.

• 한국정보시스템학회지:정보시스템연구
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• 제24권4호
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• pp.117-138
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• 2015

Purpose To meet changing social demands and fulfill the needs of the information and communications technology industry, the curriculum of MIS related department should develop and implement new conceptual frameworks. In response, the purpose of this study was to develop curriculum for students in the Department of e-Business at Kyungnam University. Design/methodology/approach We conducted a demands analysis of educational demanders, NCS(National Competency Standards) based curricular analysis, and benchmarking from other management information systems related departments. The expert panel committee consisting of e-Business department faculty members was held to examine and discuss the student-oriented curriculum developed during this study. Findings Results show that the contents and types of curriculum should be organized so that students can maximize their professional job competency to apply to their core professional tasks. Given these findings, we reconstructed the curriculum with both basic and advanced courses, all systematically organized according to the job requirements they offer toward meeting the industry's needs. We also implemented the web-based JSSS(Job Searching Support System) with which educational demanders can search among 13 job types, estimate their performances, and obtain the information about course registration. In all this study presents specific, practical evidence of the job-related curriculum for students in the Department of e-Business at Kyungnam University.

• 한국농공학회지
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• 제41권5호
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• pp.53-67
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• 1999

In this study, regional frequency analysis is used to determine each subbasin drought frequency with watershed runoff which is calculated with Tank Model in Nakdong river basin. L-Monments methd which is almost unbiased and nearly normal distribution is applied to estimate paramers of drought frequency analysis of monthly runoff time series. The duration of '76-77 was the most severe drought year than othe rwater years in this study. To decide drought frequency of each subbasin from the main basin, it is calculated by interpolaing runoff from the frequency-druoght runoff relationship. and the linear regression analysis is accomplished between drought frequency of main basin and that of each subbasin. With the results of linear regression analysis, the drought runoff of each subbasin is calculated corresponing to drought frequency 10,20 and 30 years of Nakdong river basin considering safety standards for the design of impounding facilities. As the results of this study, the proposed methodology and procedure of this study can be applied to water budget analysis considering safety standards for the design of impounding facilities in the large-scale river basin. For this purpose, above all, it is recommanded that expansion of reliable observed runoff data is necessary instead of calculated runoff by rainfall-runoff conceptual model.

• 대한조선학회논문집
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• 제53권2호
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• pp.92-100
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• 2016

A comparative method is applied to evaluate well-known formulas for estimating the size of supercavities of axisymmetric cavitators for the supercavitating underwater vehicle. Basic functional forms of these formulas are derived first for the cavity diameter from a momentum integral estimate and second for the cavity length from an asymptotic analysis of inviscid supercavity flows. The length and the diameter of axisymmetric supercavities estimated by each formula are compared, with available experimental data for a disk and a 45° conical cavitators, and also with computational results obtained by a CFD code, ‘fluent’, for conical cavitators of wide range of cone angles. Results for estimating the length and the diameter of the supercavities show in general a good agreement, which confirms the size of the supercavities for disk and conical cavitators can be estimated accurately by these simple formulas of an elementary function of cavitation number and drag coefficient of the cavitator. These formulas will be useful for from conceptual design of the cavitator to real-time control of the supercavitating underwater vehicle.

• 한국지하수토양환경학회지:지하수토양환경
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• 제24권3호
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• pp.13-23
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• 2019

The purpose of this study is to suggest conceptual models based on finite numerical method that can be used to assess contaminant transport through subsurface and estimate exposed concentration at contaminated site. This study tested various assumptions of the numerical models for contaminant transport in unsaturated and saturated zones to simulate the pathways to the human exposal point. For this purpose, models for seven possible scenarios of contaminant transport were simulated using the numerical code MODFLOW and MT3D. The simulation results that showed different peak concentrations and travel times were compared. In conclusion, the potential utility of the numerical models in the site specific risk analysis suggested as well as future research ramifications.