• Journal of Navigation and Port Research
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• v.44 no.3
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• pp.181-186
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• 2020

Until now, the development of design and operation model for automated container terminals has been mainly performed based on the western ports model, specializing in basic loading, and discharging operations. In the case of the Busan port, terminal operators provide basic stevedoring, as well as an additional logistics service known as 'On Dock Service' not suitable for the currently commercialized automated container terminal model. This study diagnosed the current Busan port's throughput structure and terminal operational characteristic, and proposed a modified perpendicular layout container terminal transport model named 'Interchange Transport Model' for effective management of empty container and operation costs. Although the 'Interchange Transport Model' requires an additional number of transport equipment (AGV), concerning operational efficiency and cost saving, a simulation showed 22% reduction of TAT and 9.4% reduction of annual terminal operational costs in comparison to the basic perpendicular layout model.

• Journal of Korea Water Resources Association
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• v.44 no.10
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• pp.777-786
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• 2011

In the previous researches for storm sewer design, the flow path, pipe diameter and pipe slope were determined to minimize the construction cost. But in the sewer networks, the flows can be changed according to flow path. The current optimal sewer layout models have been focussed on satisfying the design inflow for sewer designs, whereas the models did not consider the occurrences of urban inundation from excessive rainfall events. However, in this research, the sewer networks are determined considering the superposition effect to reduce the inundation risk by controlling and distributing the inflows in sewer pipes. Then, urban inundation can be reduced for excessive rainfall events. An Optimal Sewer Layout Model (OSLM) was developed to control and distribute the inflows in sewer networks and reduce urban inundation. The OSLM uses GA (Genetic Algorithm) to solve the optimal problem for sewer network design and SWMM (Storm Water Management Model) to hydraulic analysis. This model was applied to Hagye basin with 44 ha. As the applied results, in the optimal sewer network, the peak outflow at outlet was reduced to 7.1% for the design rainfall event with 30 minutes rainfall duration versus that of current sewer network, and the inundation occurrence was reduced to 24.2% for the rainfall event with 20 years frequency and 1 hour duration.

• Korean Journal of Construction Engineering and Management
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• v.12 no.1
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• pp.43-52
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• 2011

Unnecessary transportation of resources are one of the major causes that adversely affect construction site work productivity. Therefore, layout related studies have been conducted with efforts to develop management technologies and techniques to minimize the resource transportation made at site-level. However, although the necessity for floor-level layout planning studies has been increasing as buildings have become larger and floors have become more complicated, studies to optimize the transportation of materials inside buildings are currently not being actively conducted. Therefore, in this study, a model was developed using genetic algorithms(GA) that will enable the optimization of the locations of finishing materials on the work-floor. With the established model, the arrangement of diverse materials on complicated floors can be planned and the optimized material layout planning derived from the model can minimize the total material transportation time spent by laborers during their working day. In addition, to calculate travel distances between work sites and materials realistically, the concept of actual travel distances was applied. To identify the applicability of the developed model and compare it with existing methodologies and analyze it, the model was applied to actual high-rise residential complexes.

• Journal of Biosystems Engineering
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• v.36 no.6
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• pp.461-466
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• 2011

The purpose of this study is basically for the use of simulations to enhance productivity. In this paper, the optimal number of allocation in a small and medium industry which produces eleutherococcus senticosus sap, is performed using simulations. The simulation model was developed under considerations of production layout, process & operation, process time, total work time, work in process (WIP), utilization, failure rate, and operation efficient as inputs, and was validated with careful comparisons between real behaviors and outputs of the production line. Therefore, we can evaluate effects and changes in productivity when some strategies and/or crucial factors are changed. Although too many workers and machines could decrease productivity, the eleutherococcus senticosus sap production line in this paper has been maintained many machines. To solve this problem, we determined the optimal number of workers and machines that could not cause any interrupt in productions using simulations. This simulation model considers diverse input variables which could influence productivity, and it is very useful not only for the production line of Eleutherococcus Senticosus Sap, but also for other production lines with various purposes, especially, in the small and medium industries.

• Journal of The Korean Society of Agricultural Engineers
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• v.49 no.6
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• pp.47-54
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• 2007

This paper is on the research of the special character of the dynamic response according to a design of the clamped reinforced concrete slab. In this study, the 20-node solid element has been used to analyze the dynamic characteristics of RC slabs with clamped edges. The elasto-visco plastic model for material non-linearity and the smeared crack model have been adopted in the finite element formulation. The design factor, which affect the dynamic response of the reinforced concrete slab, are the steel layer thickness, steel layer depth, steel layout method, steel layout angle and the slab thickness and span ratio. The main purpose of this study was to find out the dynamic response of the reinforced concrete slab according to above variables. The reduction of deflection/thickness ratio appeared less than 2% when the slab thickness between 20 and 21cm. It is desirable that the slab thickness must be above 20-21cm. The reduction ratio of deflection is appeared greatly when the value of the span/thickness ratio is between 25 and 30. In conclusion, the steel layer depth and thickness had a little effect on deflection of the dynamic response, but had no effect on the steel layout angle.

• KIEAE Journal
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• v.14 no.4
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• pp.27-33
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• 2014

This study analyzed the electric vehicle recharging station status with recharging time limitation due to long waiting time, and figured out the user status by user interviews. And then this study verified the validity of hypothesis in terms of environmental design perspective and suggested layout of recharging station model. 21 recharging stations in Korea and station operation cases of 7 countries were examined. Except for the USA, the reality of electric vehicle recharging station today is the 1st proving stage focusing on the infrastructure construction of electric vehicle recharging station. It focuses on performance of recharging facility, use efficiency and operation environment of electric vehicle. About the effective waiting time of the user to use it should be studied. The current conditions of recharging station are as follows: Lack of independent recharging space, lack of facility that reduces external effect of recharging space, and lack of lounge for users during the waiting time. These three are essential factors constructing a suggesting model after basic layout, which needs proper measurement on the long recharging time and long waiting time. The essential factors are applied to electric vehicle recharging station layout so that users might use 'digital refresh" i.e. lounge and information contents service during the waiting time which provides convenience of recharging and emotional space with users. Such upgrade recharging station environmental model might resolve the burden of long recharging time which may contribute to the popularization of electric vehicles.

• Korean Journal of Construction Engineering and Management
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• v.24 no.5
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• pp.73-82
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• 2023

Optimization of Construction Site Layout Planning (CSLP) heavily relies on workers' travel paths. However, traditional path generation approaches predominantly focus on the shortest path, often neglecting critical variables such as individual wayfinding tendencies, the spatial arrangement of site objects, and potential hazards. These oversights can lead to compromised path simulations, resulting in less reliable site layout plans. While Deep Reinforcement Learning (DRL) has been proposed as a potential alternative to address these issues, it has shown limitations. Despite presenting more realistic travel paths by considering these variables, DRL often struggles with efficiency in complex environments, leading to extended learning times and potential failures. To overcome these challenges, this study introduces a refined model that enhances spatial navigation capabilities and learning performance by integrating workers' visibility into the reward functions. The proposed model demonstrated a 12.47% increase in the pathfinding success rate and notable improvements in the other two performance measures compared to the existing DRL framework. The adoption of this model could greatly enhance the reliability of the results, ultimately improving site operational efficiency and safety management such as by reducing site congestion and accidents. Future research could expand this study by simulating travel paths in dynamic, multi-agent environments that represent different stages of construction.

• Journal of Power Electronics
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• v.18 no.4
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• pp.1255-1267
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• 2018

Parasitic parameters have a larger influence on Silicon Carbide (SiC) devices with an increase of the switching frequency. This limits full utilization of the performance advantages of the low switching losses in high frequency applications. By combining a theoretical analysis with a experimental parametric study, a mathematic model considering the parasitic inductance and parasitic capacitance is developed for the basic switching circuit of a SiC MOSFET. The main factors affecting the switching characteristics are explored. Moreover, a fast-switching double pulse test platform is built to measure the individual influences of each parasitic parameters on the switching characteristics. In addition, guidelines are revealed through experimental results. Due to the limits of the practical layout in the high-speed switching circuits of SiC devices, the matching relations are developed and an optimized layout design method for the parasitic inductance is proposed under a constant length of the switching loop. The design criteria are concluded based on the impact of the parasitic parameters. This provides guidelines for layout design considerations of SiC-based high-speed switching circuits.

• Architectural research
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• v.1 no.1
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• pp.31-40
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• 1999

In this age of "Information", many people consider it a deterrent to information flow to provide a hierarchy with private rooms in a modern office layout. There are others, however, who insist that visual and acoustical privacy are more important than any other design factor in achieving higher productivity. The debate may never end, but the partitioned open plan, which is a new form of the vast open plan, has merits of each concept - open and closed layout. Consequently, office design has dramatically shifted to partitioned open planning, with shorter, temporary walls or partitions, originally intended for increasing privacy and diminishing hierarchy, yet still keeping flexibility in spatial organization. The introduction of low-level partitioned spaces in an office layout, however, produces a complicated lighting design problem. Obviously, accurately predicted daylighting performance data are needed not only for daylighting design but for artificial lighting system design. Scale models of 12 sets of unit partitioned spaces are constructed and extensive scale model measurements of both daylight and reflected sunlight have been performed within an artificial sky simulator. The prototype-building interior is modeled with different partition configurations, each of which is modeled using the different envelope geometry and exterior configurations, and then the variations in interior light levels are estimated. The result indicates that partitioned spaces employed in an open plan of modern offices still offer a large potential for daylighting and energy saving as well. Much of the savings may derive from the cumulative effect of reflected sunlight. Optimal design for building envelope geometry and exterior configuration promises additional savings.

• Journal of the Korea Society for Simulation
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• v.12 no.3
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• pp.41-53
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• 2003

The major components of an engine are engine block (or cylinder block), cylinder head, crank shaft, connecting rod and cam shaft. Thus the engine shop usually consists of six sub-lines, five machining lines and one assembly line. Flow line is the typical concept of layout for machining these parts, especially for engine block. In order to design an engine block machining line, several factors should be considered such as yearly production target, working hours, machines, tools, material handling equipments and so on. If the designers of manufacturing line were unaware of some factors those would be influenced on the system performance, it would make greater problems in the phase of mass production. Therefore the initial design of engine block machining line should be verified carefully. Simulation is the most powerful tool for analyzing the initial layout. This paper introduces the major factors those should be considered for designing the machining line and their effects on the system performance. 3D simulation models are developed with QUEST. Using the simulation model developed the initial layout is analyzed, and we suggest some ideas for improvement.