• Journal of the Korean Institute of Landscape Architecture
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• v.40 no.4
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• pp.28-35
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• 2012

Recently, as the social interest increase has been focused on new renewable energy system to build-up sustainable urban planning system, the related studies have been actively conducting. As well as in other areas, the construction area, which accounts for over 40% of the total energy consumption, clearly showed this tendency. Whereas, various landscape facilities applying renewable energy equipments have been manufactured and installed, systematic study available for planning and designing is rarely found in Korea. This study is expected to contribute to the landscape planning and designing by quantifying the energy-efficient and economic advantages of the renewable energy system for landscape facilities. For this purpose, the analysis on the energy-efficiency and economic values under the scenario that the current fossil power supply for the streetlights in urban parks in Seoul, Daegu, and Incheon were replaced by photovoltaic power generation were performed through RETScreen$^{(R)}$ a clean energy simulation program based on the NASA Satellite Meteorological Data. As a result, the generated power and the economic values vary depending on the climatic features of the appointed cities. This study will be used to build up the effective decision-making in applying the clean renewable system to the plan and design of landscaping.

• Journal of the Korean GEO-environmental Society
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• v.21 no.4
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• pp.5-17
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• 2020

In recent years, the frequency of heavy rainfall associated with high rainfall intensity has been continuously increasing due to the effects of climate change; and thus also causes an increase in watershed soil erosion. The existing estimation techniques, used for the prediction of soil erosion in Korea have limitations in predicting the: average soil erosion in watersheds, and the soil erosion associated with abnormal short-term rainfall events. Therefore, it is necessary to consider the characteristics of torrential rainfall, and utilize physics-based model to accurately determine the soil erosion characteristics of a watershed. In this study, the rainfall kinetic energy equation, in the form of power function, is proposed by applying the probability density function, to analyze the rainfall particle distribution. The distributed rainfall-erosion model, which utilizes the proposed rainfall kinetic energy equation, was utilized in this study to determine the soil erosion associated with various typhoon events that occurred at Cheoncheon watershed. As a result, the model efficiency parameters of the model for NSE and RMSE are 0.036 and 4.995 ppm, respectively. Therefore, the suggested soil erosion model, coupled with the proposed rainfall-energy estimation, shows accurate results in predicting soil erosion in a watershed due to short-term rainfall events.

• Journal of the Korea Concrete Institute
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• v.18 no.3 s.93
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• pp.339-346
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• 2006

The purpose of this study is to suggest a method to quantitatively predict long-term deformation of walls under an axial load concentrated to a part of the whole width. Four wall specimens were tested and three-dimensional finite element analyses were performed for these specimens. The finite element models established in this study were verified from the test results. On the basis of this verification, analysis parameters were selected considering various dimensions of walls and sectional area that a concentrated load is acting on, and finite element analyses for these parameters were carried out. The concept of the effective width coefficient was newly introduced as a method to predict the long-term behavior of walls, and a function that is able to optimally fit the effective width coefficients calculated from the analysis results for the selected parameters was found from regression analysis. The found function can be conveniently used in practice to predict the long-term behavior under loads concentrated to a local area of the whole width of walls.

• Journal of the Institute of Electronics Engineers of Korea SP
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• v.47 no.5
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• pp.153-164
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• 2010

A program consumes energy by executing its instructions. The amount of cosumed power is mainly proportional to algorithm complexity and it can be calculated by using complexity information. Generally, the complexity of a S/W is estimated by the microprocessor simulator. But, the simulation takes long time why the simulator is a software modeled the hardware and it only provides the information about computational complexity quantitatively. In this paper, we propose a complexity estimation method of analysis of S/W on source code level and produce the complexity metric mathematically. The function-wise complexity metrics give the detailed information about the calculation-concentrated location in function. The performance of the proposed method is compared with the result of the gate-level microprocessor simulator 'SimpleScalar'. The used softwares for performance test are $4{\times}4$ integer transform, intra-prediction and motion estimation in the latest video codec, H.264/AVC. The number of executed instructions are used to estimate quantitatively and it appears about 11.6%, 9.6% and 3.5% of error respectively in contradistinction to the result of SimpleScalar.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.2 no.1 s.2
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• pp.15-24
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• 2003

While public institutions and privite coperations have constructed the data collecting infrastructure and commercialized it to service traffic information, inaccuracy with information, insufficiency with the public sector, overapping investment and the rest are arising from the differences of data treatment, offering method, communication protocal and the like. For these reasons, we need standardization it as a national enterprise. In this paper, we would like to present the unity management and joint method of traffic information based on the present position of system construction and national ITS standardization. At first, we presented the relation between data elements and message sets and then analyzed how message sets have been used to message sets to share traffic information so far in public institutions and private coperations like Korea freeway cooperation-ITS model city-Cheonan-Nonsan expressway, In-cheon international airport expressway-Korea freeway cooperation and Seoul metropolitan police agency-Seoul metropolitan government. As the results of analyzing message sets, it had disclosed that data transmission is impossible or a system is unchangeable because data form and each items to transmission were different from each other and its own address and link IDS were not determined yet. Also it showed these message sets did not abidy by The Draft of National ITS Standards. First of all, we proposed data basic form and elements which were form by items used in each center in common and the elements to manage traffic information suggested by Standards based on the results of analyses.

• Journal of the Economic Geographical Society of Korea
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• v.11 no.4
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• pp.549-563
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• 2008

The purpose of this research is to identify the urban structure in Korea. Though there is research regarding urbanization, there is little regarding the urban structure of the Korean economy. In this paper, two issues will be discussed: the measurements of inter-city and intra-city structure in Korean Metropolitan Statistical Areas (MSAs), which is newly defined. First, the city size rank rule, widely known as Zipf’s Law, will illustrate Korean the inter-city structure. The city size rank rule gives an idea whether Korean MSAs are balanced or not. In general, Korea has a heavy concentration in the Seoul MSA in terms of population. It could be either that the Seoul MSA is too big or that the Busan MSA is too small or both. If this is the primacy problem, a decentralization policy is necessary. On the other hand, if it is a second city problem, development policies for the Busan MSA and Daegu MSA are more important. Next, the Korean intra-city structure will be discussed. The evolutions of the MSAs explain intra-city structure by analyzing population density function and the housing price function. Some large MSAs such as Seoul and Busan have experienced urban sprawl, while other MSAs have experienced urban concentration. The population density gradient by the distance from the ARC GIS shows the growth rate of a city. According to the Spatial Mismatch Index between population and employment, the Ulsan MSA, Gwangju MSA, and Suwon-Hwaseong-Osan MSA are more mismatched, while the Daejeon MSA and Incheon MSA are less mismatched. Therefore, these analyses of Korean urban structure are meaningful in developing regional policy.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.36 no.5
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• pp.553-562
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• 2012

Computational Fluid Dynamics (CFD) analysis has been performed to estimate the air temperature inside an Auxiliary Feed Water (AFW) Motor-Driven (MD) pump room for the case where there is loss of Heating, Ventilation, and Air-Conditioning (HVAC). A transient calculation for the closed pump room without cooling by any HVAC system shows that the volume-averaged air temperature reaches around $60^{\circ}C$ for a transient period of 8.0 h. From previous studies, the external air and surface boundary temperatures are assumed to increase slowly starting from an initial temperature of $35^{\circ}C$. For the cases where the door is opened at 2, 4, and 6 h after the initiation of HVAC failure, the average air temperature promptly drops by about $4^{\circ}C$ when the door is opened and then slowly increases. The current calculations based on the CFD technique predict the rate of increase of air temperature to be lower than that determined by previous conservative calculations on the basis of a lumped model.

• The Journal of Society for e-Business Studies
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• v.10 no.1
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• pp.61-80
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• 2005

Business Process Management (BPM) System is a software system to support an efficient execution, control and management of business processes. The system automates complex business processes and manages them effectively to raise productivity. Traditional commercial systems mainly focus on automating processes and do not have methods for enhancing process performances and task performer's efficiency. Therefore, there is room for enhancement of task performers' productivities and efficiency of business processes. In this paper, we propose a new method of executing business processes more efficiently in that a whole process is scheduled considering the degree of participants' workload. The method allows managing the largest constraints among constituent resources of the process. This method is based on the DBR (Drum-Buffer-Rope) in TOC (Theory of Constraints) concepts. We first consider the differences between business process models and DBR application models, and then develop the modified drum, buffer and rope. This leads us to develop BP-DBR (Business Process-DBR) that can control the proper size of task performers' work list and arrival rate of process instances. Use of BP-DBR improves the efficiency of the whole process as well as participants' working condition. We then carry out a set of simulation experiments and compare the effectiveness of our approach with that of the scheduling techniques used in existing systems.

• Korean Journal of Agricultural Science
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• v.23 no.1
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• pp.13-24
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• 1996

The following results were obtained by analyzing the displacement, strain and stability of ground at the soft ground excavation using sheet pile. 1. Before setting the strut, the horizontal displacement was large on the upper part of excavated side, but after setting the strut, it showed concentrated phenomenon while being moved to go down to the excavated side. 2. After setting the strut, the displacement of sheet pile was rapidly decreased about a half compared with before setting the strut. The limitation of excavation depth was shown approximately GL-8m after setting double stair strut. 3. Maximum shear strain was gradually increased with depth of excavation, and local failure possibility due to shear deformation at the bottom of excavation was decreased by reinforcement of strut. 4. Maximum horizontal displacement of sheet pile at GL-7.5m was shown 0.2% of excavation depth in elasto-plastic method, and 0.6% in finite-element methods, and the maximum displacement was occurred around the bottom of excavation. 5. To secure the safety factor about penetration depth in the ground of modeling, D/H should be more than 0.89 in the case of one stair strut, and more than 0.77 in the case of double stair strut. 6. The relation of safety factor and D/H about the penetration depth was appeared, Fs=0.736(D/H) + 0.54 in the case of one stair strut, and Fs=0.750(D/H) + 0.62 in the case of double stair strut.

• Journal of the Computational Structural Engineering Institute of Korea
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• v.29 no.5
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• pp.483-490
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• 2016

In plant industry, sulfur storage tank is made of steel and annular plate is connected with concrete foundation of ring wall type by anchor bolt. Due to keep sulfur at high temperature in tank by coil, sulfur storage tank is expanded larger than another tank stores fluid at room temperature. Generally, structural design of tank foundation is performed analysis with loading of temperature gradient between inner and outer surface, this method can't consider the phenomenon that load is intensively transferred to concrete foundation at anchor bolt. This means that temperature load is underestimated and causes crack of concrete near anchor bolt. In this study, evaluation formula considering temperature load transfer mechanism through anchor bolt is proposed and load acting on concrete foundation is rationally decided. For this purpose, it is analyzed variation of thermal load per various anchor bolt number using finite element model including tank annular plate and anchor bolt. Solution is proposed as specified term combining result of analysis and theoretical solution for evaluating load transferred by anchor bolt. For confirmation of validation of proposed formula, it is applied in design of sulfur storage tank at plant site, it shows that the formula can be practically applied.