• Journal of the Korean Institute of Landscape Architecture
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• v.20 no.4
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• pp.93-101
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• 1993

The purpose of this study is to analyze th especificity of landscape construction progress in order to develop the model of landscape construction schedule management. Nine case study area in housing complex was selected and the graphic curve of the accumulative payment by landscape construction schedule was analyzed. And the results are as follows: The graphic curve of common construction progress is S-curve but that of landscape construction progress is parabolic-curve, because landscape construction concentrally progress in last period of construction schedule. And particularly parabolic-curve seems to rise up suddenly in the last period when landscape construction amount is small.

• Journal of Information Processing Systems
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• v.7 no.4
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• pp.613-626
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• 2011

In this paper, we focus on the pinwheel task model with a variable voltage processor with d discrete voltage/speed levels. We propose an intra-task DVS algorithm, which constructs a minimum energy schedule for k tasks in O(d+k log k) time We also give an inter-task DVS algorithm with O(d+n log n) time, where n denotes the number of jobs. Previous approaches solve this problem by generating a canonical schedule beforehand and adjusting the tasks' speed in O(dn log n) or O($n^3$) time. However, the length of a canonical schedule depends on the hyper period of those task periods and is of exponential length in general. In our approach, the tasks with arbitrary periods are first transformed into harmonic periods and then profile their key features. Afterward, an optimal discrete voltage schedule can be computed directly from those features.

• International conference on construction engineering and project management
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• 2005.10a
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• pp.929-934
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• 2005

The complex and dynamic job nature and the ever-changing working environment of construction projects inevitably present uncertainties to construction operations. Identification, evaluation and control of uncertainties constitute main elements of risk management and critical tasks of project management in construction. This paper is focused on application of a simplified discrete-event simulation approach in management of schedule-overrun risks, each being the combination of the occurrence probability of an uncertain interruptive factor and its potential consequence in terms of time delay. A case study observed from a concreting operation in Hong Kong is converted into a simulation model and analyzed with an in-house-developed simulation package for demonstrating how the proposed approach can be implemented to manage multiple schedule-overrun risks on construction projects.

• Journal of Internet Computing and Services
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• v.8 no.2
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• pp.23-31
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• 2007

If the effort(manpower) and schedule are estimated, there is very difficult to allocate the manpower according to the schedule time units efficiently. Generally, the Putnam's Rayleigh Model has been applied popularly. This distribution model is expressing topology that manpower is consumed concentrically in first-half point. But actual manpower of projects are consumed concentrically at middle or second half point. Therefore, this model cannot be applied in software project planning area. This paper suggests a model to distribute manpower efficiently. Fist of all, we investigate a typical type presenting in software development field and manpower profile type of actuality development projects. Next, we suggested a method to present the model by a drawing a contour about manpower profile for the efficient manpower distribution. The proposed model shows better performance than Rayleigh and Gomma model. By applying proposed model, we will properly distribute manpower to schedule in software development planning phase, and finally we may manage project successfully.

• Journal of Astronomy and Space Sciences
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• v.27 no.4
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• pp.407-412
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• 2010

Software reusability is one of key factors which impacts cost and schedule on a software development project. It is very crucial also in satellite simulator development since there are many commercial simulator models related to satellite and dynamics. If these models can be used in another simulator platform, great deal of confidence and cost/schedule reduction would be achieved. Simulation model portability (SMP) is maintained by European Space Agency and many models compatible with SMP/simulation model interface (SMI) are available. Korea Aerospace Research Institute (KARI) is developing hardware abstraction layer (HAL) supported satellite simulator to verify on-board software of satellite. From above reasons, KARI wants to port these SMI compatible models to the HAL supported satellite simulator. To port these SMI compatible models to the HAL supported satellite simulator, simulation scheduler is preliminary designed according to the SMI standard.

• Journal of Korean Institute of Industrial Engineers
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• v.37 no.2
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• pp.132-143
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• 2011

This paper deals with a coal supply planning problem for power plants. We propose a mathematical optimization model to make decisions for coal pile sections, movement of reclaimers, and operation time of conveyor belts. The objective of the proposed model is to minimize the total operation time of conveyor belts and total movement time of reclaimers. The algorithm firstly selects a pile section by considering both the location of reclaimers and the stock amount on that pile section. And then the shortest path from the selected pile section has to be put into the operation schedule and check whether the total operation time is satisfied. Then finally the new schedule is updated. To this end, we have tested the proposed algorithm comparing with the general standard optimization package for the simplified problem SCSPP. From the numerous test runs for comparing with the existing coal supply scheduling methods, We see that the proposed model may improve the coal supply operation by reducing significant coal supply costs.

• International conference on construction engineering and project management
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• 2022.06a
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• pp.608-615
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• 2022

Construction projects are large-scale projects that require extensive construction costs and resources. Especially, scheduling is considered as one of the essential issues for project success. However, the schedule and resource management are challenging to conduct in high-tech construction projects including complex design of MEP and architectural finishing which has to be constructed within a limited workspace and duration. In order to deal with such a problem, this study suggests resource and sequence optimization using constraint programming in construction projects. The optimization model consists of two modules. The first module is the data structure of the schedule model, which consists of parameters for optimization such as labor, task, workspace, and the work interference rate. The second module is the optimization module, which is for optimizing resources and sequences based on Constraint Programming (CP) methodology. For model validation, actual data of plumbing works were collected from a construction project using a five-minute rate (FMR) method. By comparing actual data and optimized results, this study shows the possibility of reducing the duration of plumbing works in construction projects. This study shows decreased overall project duration by eliminating work interference by optimizing resources and sequences within limited workspaces.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.10 no.6
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• pp.1281-1286
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• 2009

Our government operates earned value management system (EVMS)of construction schedule and cost for improving earned management system of the construction projects. but There is two unification Method construction schedule and cost to estimate construction progress currently. This weight a staff work. therefore this study present unification method which operate integrate schedule and cost by using work task. In order to inflect verification and model of schedule and cost, this study develop prototype of EVMS.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.12 no.6
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• pp.155-164
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• 2012

The compression of software development schedule has a limit without regarding to a development manpower. However, the actually developed softwares includes the impossible short time or unreal long time date. Previously suggested models are driving the development schedule from all of the actually developed software without considering these constraints. This paper recommends a standard of minimum and the most suitable development time period. This paper has chosen a criterion that shows the best development schedule among 5 criteria based on the actually performed projects. Moreover, this paper suggests a model that estimates the development schedule based on the best criterion.

• 정보저장시스템학회:학술대회논문집
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• 2005.10a
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• pp.139-144
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• 2005

Because of the photorefractive recording dynamics, each newly recorded hologram partially erases all previously stored image. Thus achieving the desired diffraction efficiency profile for the entire sequence after all images have been recorded requires exposure time schedule. The often cited classical exposure-schedule model predicts a rising-exponential build-up and an exponential decay in An with an exposure time. However because we cannot directly measure the An, it's difficult to establish the relation of both. In this paper, we deduce the relation of diffraction efficiency and exposure time from experiment data and suggest an algorithm to make time schedule profile in angle/fractal multiplexing of holographic data storage. After that, we present simulated result with equal hologram diffraction efficiency for a sequence of 250 holograms recorded by angle/fractal multiplexing.