• 산경연구논집
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• 제7권3호
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• pp.5-12
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• 2016

Purpose - In this paper, we consider more segmented types of markets than conventional version of ones in South Korea and explore the degree of relations between these markets and the related factors with them. In this case, ten attributes of types of markets mentioned above will be considered. To be more specific, the numerical strength is evaluated and graphical approach is expressed on two-dimensional plane, if the association exists between the considered variables. Research design, data, and methodology - This work is done by the 2013 report on the commercial building lease offered by Small Businessmen Promotion Institute (May/2013~August/2013) and exploited by statistical analyses such as correspondence analysis and a chi-squared test in IBM SPSS 23.0. Results - Findings of this paper indicate that a variable Korean market, including traditional markets, are closely connected with variables administrative district, sales and occupation instead of company, age group and business duration and the detailed associations between variables can be obtained by inspecting results of correspondence analysis. Conclusions - We can understand where the status of the Korean markets stands now through this work and also government authority and local autonomy can take advantage of these findings to enhance the revitalization of Korean markets and other markets.

• 한국건축시공학회지
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• 제13권6호
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• pp.565-578
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• 2013

Batch production is common in repetitive construction projects, and it is not unusual for different batch sizes to be used by contractors in one project. While several scheduling methods, such as the Linear Scheduling Method (LSM) and the Repetitive Scheduling Method (RSM) have been proposed and used, no mathematical method for repetitive construction projects has been developed, and it is difficult to consider different batch sizes with the existing methods. An original mathematical algorithm for scheduling repetitive projects with different batch sizes is proposed in this study. This algorithm is illustrated with assumptions of resource continuity and single path in a project and introduces new terms, control batch and critical batch. The algorithm logics and mathematical equations are validated by comparison with the outcomes from a graphical scheduling approach through a simple and practical hypothetic project. As a result, it is expected that the proposed algorithm can be easily adapted and extended to computer software for scheduling, and can be a starting point for research on batch size management in repetitive construction projects.

• International Journal of CAD/CAM
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• 제6권1호
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• pp.183-192
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• 2006

A CAD/CAM system has been developed for rapid prototyping (RP) of microfluidic devices based on excimer laser micromachining. The system comprises of two complementary softwares. One, the CAM tool, creates part programs from CAD models. The other, the Simulator Tool, uses a part program to generate the laser tool path and the 2D and 3D graphical representation of the machined microstructure. The CAM tool's algorithms use the 3D geometry of a microstructure, defined as an STL file exported from a CAD system, and process parameters (laser fluence, pulse repetition frequency, number of shots per area, wall angle), to automatically generate Numerical Control (NC) part programs for the machine controller. The performance of the system has been verified and demonstrated by machining a particle transportation device. The CAM tool simplifies part programming and replaces the tedious trial-and-error approach to creating programs. The simulator tool accepts manual or computer generated part programs, and displays the tool path and the machined structure. This enables error checking and editing of the program before machining, and development of programs for complex microstructures. Combined, the tools provide a user-friendly CAD/CAM system environment for rapid prototyping of microfluidic devices.

• 컴퓨터교육학회논문지
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• 제4권2호
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• pp.105-114
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• 2001

본 논문에서는 Mathematica를 자바 언어로 연결하는 J/Link를 이용하여 웹기반 환경에서 미적분 문제의 해를 단계별로 제시하는 모듈을 소개하였다. 이 모듈은 중하위 수준의 학생들에게 미분 문제의 해를 단계별로 제시함으로써 문제해결의 과정을 단계별로 연습할 수 있는 환경을 제공하고 있다. 또한, 학생들에게 미분 연산자를 적용할 함수와 미분된 결과 함수에 대한 그래픽 결과를 보여줌으로써 미적분 개념에 대한 이해의 폭을 넓히는 효과를 노렸다. 수학 전문가시스템인 Mathematica는 미분 문제의 해결 과정을 단계별로 제시함으로써 수학 지식을 체계적으로 제공하는 기반을 마련하고 있으며, 수학 학습용 튜토리얼 또는 CMI로 연계될 수 있는 가능성을 보여주고 있다. 또한 이 시스템은 FrontEnd에서 처리되는 수식 폰트를 자바서브릿에서 처리함으로써 웹환경에서 수식 기호를 우회적으로 구현하는 방법을 제시하고 있다.

• 수산해양교육연구
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• 제28권1호
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• pp.172-179
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• 2016

The study of Mobile MGIS (Marine Geographic Information System) based on the Android Mobile Platform is mainly performed on effective methodologies which transform real world data to computing world data. Mobile GUI system has its own target on reliable data service by acquisition of geometric information using EFDC (Environmental Fluid Dynamics Code) Model, accurate measurement and graphical visualization. Even simple visualizations can aid in the interpretation of complex hydrodynamic relationships that are frequently encountered in the marine environment. The Mobile MGIS provides an easy way for hydrodynamics geoscientists to construct complex visualizations that can be viewed with free software. This study proposes a Mobile GUI MGIS using EFDC Model result of Seomjin River estuary. Finally, we design a Seomjin River estuarine Coastal Waters Mobile MGIS integrating above data models. It must adds more ecological information and the various service item for approach more easily in order to user.

• 대한교통학회:학술대회논문집
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• 대한교통학회 1995년도 제27회 학술발표회
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• pp.35-56
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• 1995

이 글에서는 공항 여객터미날에 대한 계획 및 운영관리의 실행기준을 인지-반응모델을 이용하여 결정하는 방법을 논의하고자한다. 제시된 접근방법은 서비스의 폭을 승객의 입장에 따라 결정.분류하는 방법이다. 이것은 새로운 개념으로서 공항시스템의 특성을 고려하여 이용승객에 대한 직접적인 조사를 통해 각 시설별 수용능력 및 서비스 수준을 가늠할 수 있도록 도와준다. 이 접근방법에서는 이용자들의 서비스 기대치와 실질적인 서비스 제공에 따른 인식과의 차이를 통해 기준을 설정하는 것으로서 공항 계획자, 디자이너, 운영자 그리고 공항관리자들에게 실질적이고 용이한 기법으로 제공될 수 있다.

• 한국측량학회지
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• 제16권1호
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• pp.139-147
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• 1998

국토에 대한 공간정보의 기본도로서 다양한 사용자의 요구사항을 충족시킬 수 있는 수치지도를 효율적으로 제작 및 유지관리하기 위해서는 수치지도의 데이터 모델과 구조 등 수치지도 데이터 구축에 대한 연구가 중점적으로 이루어져야 한다. 본 연구에서는 단순 지도제작을 목적으로 구축된 기존 수치지도의 데이터 모델에 대한 문제점을 파악하여, 개선된 수치지도 데이터 모델의 개념적ㆍ논리적 모델을 제시하였다. 제시된 수치지도 데이터 모델은 기존에 제작된 수치지도 데이터의 사용을 전제로 설계되었으며, 다양한 사용자의 요구사항을 반영하기 위해서 데이터 모델의 유연성에 중점을 두었고, 필요에 따라서 수정이 용이하도록 단계별 접근방법에 의해 설계되었다. 또한 제시된 수치지도 데이터 모델은 향후 객체 지향형 모델로 나아가기 위한 중간 단계의 데이터 모델이다.

• 한국지구물리탐사학회:학술대회논문집
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• 한국지구물리탐사학회 2007년도 공동학술대회 논문집
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• pp.64-68
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• 2007

The classic graphical method to determine the epicenter uses differences between the arrival times of P and S waves at each station. In this research, a robust approach is proposed, which provides a fast and intuitive estimation of earthquake epicenters. This method uses an empirical relationship between epicentral distance and traveltime of the first arrival P phase of local or regional earthquake. The relationship enables us to estimate epicentral distances and draw epicentral circles from each station with P-traveltimes counted from a probable origin time. As the assigned time is getting close to the origin time of the earthquake, epicentral circles begin to intersect each other at a possible location of the epicenter. Then the possibility of the epicenter can be expressed by a function of the time and the space. We choose the location which gives the minimum standard deviation of the origin time as an estimated epicenter. In this research, 918 P arrival times from 84 events occurring from 2005 to 2006 listed in the KMA earthquake catalog are used to determine the empirical P-traveltime function of epicentral distances.

• Nuclear Engineering and Technology
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• 제49권8호
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• pp.1660-1668
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• 2017

The flow of liquids submerged with nanoparticles is of significance to industrial applications, specifically in nuclear reactors and the cooling of nuclear systems to improve energy efficiency. The application of nanofluids in water-cooled nuclear systems can result in a significant improvement of their economic performance and/or safety margins. Therefore, in this paper, Marangoni thermal convective boundary layer dusty nanoliquid flow across a flat surface in the presence of solar radiation is studied. A two phase dusty liquid model is considered. Unlike classical temperature-dependent heat source effects, an exponential space-dependent heat source aspect is considered. Stretching variables are utilized to transform the prevailing partial differential system into a nonlinear ordinary differential system, which is then solved numerically via the Runge-Kutta-Fehlberg approach coupled with a shooting technique. The roles of physical parameters are focused in momentum and heat transport distributions. Graphical illustrations are also used to consider local and average Nusselt numbers. We examined the results under both linear and quadratic variation of the surface temperature. Our simulations established that the impact of Marangoni flow is useful for an enhancement of the heat transfer rate.

• Environmental Engineering Research
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• 제24권4호
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• pp.711-717
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• 2019

The application of advanced oxidation for the treatment of oil refinery wastewater under UV radiation by using nanoparticles of titanium dioxide was investigated. Synthetic wastewater prepared from phenol crystals; Power Glide SAE40 motor vehicle oil and water was used. Response surface methodology (RSM) based on the Box-Behnken design was employed to design the experimental runs, optimize and study the interaction effects of the operating parameters including catalyst concentration, run time and airflow rate to maximize the degradation of oil (SOG) and phenol. The analysis of variance and the response models developed were used to evaluate the data obtained at a 95% confidence level. The use of the RSM demonstrated the graphical relationship that exists between individual factors and their interactive effects on the response, as compared to the one factor at time approach. The obtained optimum conditions of photocatalytic degradation are the catalyst concentration of 2 g/L, the run time of 30 min and the airflow rate of 1.04 L/min. Under the optimum conditions, a 68% desirability performance was obtained, representing 81% and 66% of SOG and phenol degradability, respectively. Thus, the hydrocarbon oils were readily degradable, while the phenols were more resistant to photocatalytic degradation.