• Journal of the Korean Institute of Landscape Architecture
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• v.40 no.2
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• pp.97-111
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• 2012

This study aims to find a proper construction cost calculation method by comparing unit prices of cost estimate in landscape construction among other public ordering construction projects. There were 7 out of 12 items from the actual work cost in the first half of 2011 were compared. The 12 items were classified as landscape Architectural construction and the 7 items were the approximate standard. As applied construction types, the comparable 35 items out of the 80 actual work cost items applied to 5 sites were compared to the unit price of the standard quantity per unit in March 2011, which was the approximate standard. Actual construction rate of the 7 items in the category of landscape sector was 104.86% for each item and 92.09% as a total construction cost. The high actual construction rate was caused by the high rate of seed spray depending on the status of applying rocks. However, there were more fundamental reasons for the cost generated from aslope treatment for grass and seed spray. So, it requires more detailed regulations on the modification factors for each soil type, the standard and needs to improve theillogical standard quantity per unit system. Actual construction rate of the 35 items in the applied sectors of civil engineering and architecture was 78.65% for each item and 71.31% (70.17%) as a total construction cost. This shows that actual unit cost cannot reflect actual cost structurally and standard quantity per unit system lacks practicality in terms of construction due to thelabor force. 85.1~91.2 % actual construction rate announced by the Ministry of Land and Maritime Affairs referred to the newly switched items. So the result was estimated as actual construction rate. This requires supplementation after verification in order to make the actual work cost produce at a proper rate. Also, standard quantity per unit system needs complementation with these actual data and so on.

• Proceedings of the IEEK Conference
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• 2002.07a
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• pp.377-380
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• 2002

When it calculates the optimum price of filter coefficient, the many operation quantity is necessary. Is like that the real-time control is difficult and the hardware embodiment expense is big. The case which does not know advance information of input signal or the case where the statistical nature changes with change of surroundings environment is necessary the adaptive filter. Every hour to change a coefficient automatically and system in order to reach to the condition of optimum oneself, the fact that is the adaptive filter. When it does not the quality of input signal or it does not know the environment of surroundings every hour changing, it does not emit not to be, in order to collect, the fact that is the adaptive filter. The case of the Acoustic Echo Canceler does thousands filter coefficients in necessity. It reduces a many calculation quantity to respect, it uses the IIR filter from hour territory. Also it uses the block adaptive filter which has a block input signal and a block output signal. The former there is a weak point where the stability discrimination is always demanded. Consequently, The block adaptive filter is researched plentifully. This dissertation planned the block MADF adaptive filter used to MADf algorithm.

• Structural Engineering and Mechanics
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• v.62 no.3
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• pp.345-355
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• 2017

The aim of the present study is to develop an elemental approach based on the differential quadrature method for free vibration analysis of cracked thin plate structures. For this purpose, the equations of motion are established using the classical plate theory. The well-known Generalized Differential Quadrature Method (GDQM) is utilized to discretize the governing equations on each computational subdomain or element. In this method, the differential terms of a quantity field at a specific computational point should be expressed in a series form of the related quantity at all other sampling points along the domain. However, the existence of any geometric discontinuity, such as a crack, in a computational domain causes some problems in the calculation of differential terms. In order to resolve this problem, the multi-block or elemental strategy is implemented to divide such geometry into several subdomains. By constructing the appropriate continuity conditions at each interface between adjacent elements and a crack tip, the whole discretized governing equations of the structure can be established. Therefore, the free vibration analysis of a cracked thin plate will be provided via the achieved eigenvalue problem. The obtained results show a good agreement in comparison with those found by finite element method.

• Journal of KIBIM
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• v.7 no.2
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• pp.8-15
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• 2017

Building Information modeling is playing an important role in transforming the construction industry. It helped the industry with better visualization, minimum design errors, and excellent planning of the construction activities. Time and cost saving can be effectively achieved by using BIM for any construction project. It improves information exchange between all the project stakeholders. However, the development of earthwork 3D BIM is still underway and has not been fully implemented yet. This paper presents the study of a complete process for Earthwork BIM design using Autodesk Civil 3D. A real site road construction project is used as a case study to explain the process of earthwork modeling, starting from laser scanning to 3D model. Quantity take off calculation is very important part of any road construction project so during this study earthwork volume from two 3D earthwork model is calculated. The results obtained through this study will be the basis for future work which has been concluded in this paper.

• Journal of Korean Society on Water Environment
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• v.25 no.6
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• pp.972-978
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• 2009

This study modifies the present total maximum daily load (TMDL) system of Ministry of Environment and applies to the Anyangcheon watershed. Hydrologic Simulation Program-FORTRAN (HSPF) model is used to simulate both runoff and non-point source pollution, simultaneously, instead of QUAL2E. The drought flow (355th daily flow) is proposed for the target water quantity since it is easier to satisfy low flow (275th daily flow) for the target water quality than drought flow. The increase of discharge is more than the increase of pollutant load except for the period under low flow. The measured unit loads for non-point source are used to consider the regional runoff characteristics. The measured water quantity and quality data are used since the ministry of environment supports only water quality. This analysis results show some reasons for the improvement of the present TMDL system of Korea.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.37 no.4
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• pp.231-238
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• 2014

Optimum lot size calculation for real world manufacturing environment has been focused since last few decades. Several extensions have been made to the basic economic order and production order quantity models to realize the possible practical situations in industry. However, focus on work-in-process inventory has been ignored relatively. This paper provides a comprehensive review of the models developed for group technology based manufacturing environment focusing on work-in-process inventory. Models have been extended from a perfect manufacturing conditions to an imperfect manufacturing situation considering rework, rejection and inspection. Optimum lot size has been evaluated using a simple algebraic optimization approach. Significant parameters are highlighted using sensitivity analysis for the developed models. Numerical example is used to illustrate the utilization of such models in day-to-day production setups and the impact of significant factors' variation on total cost and optimum lot size.

• Journal of the Architectural Institute of Korea Structure & Construction
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• v.35 no.5
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• pp.145-152
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• 2019

In this study, rebar QTO(Quantity Take-Off) was quickly produced from the BIM model prepared by Revit in the early design phase, and the available premium rates were quantitatively presented. For this purpose, the amount of rebar calculated using the BuilderHub, which specializes in calculating rebar QTO, was analyzed according to various factors such as member type, rebar diameter, building size, item type, and order length, and the effect of each factor on the rebar QTO was determined. In addition, the BIM model generated on Revit was used to establish parameters and processes required to produce rebar QTO, and proposed a rebar premium rate and a stirrup/hoop premium rate based on the BuilderHub output results. Through this study, it is expected that a rapid and efficient comparative evaluation of rebar QTO will be possible according to various structural design alternatives in the early design phase.

• Korean Journal of Construction Engineering and Management
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• v.19 no.6
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• pp.3-13
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• 2018

The formwork cost amounts for a significant proportion of project construction costs. It costs 10-15% of the total construction cost and 30-40% of the frame structure construction cost. In addition, the formwork collapse accidents are frequently causing deaths in the construction industry, and thus, is known to be of relatively high degree of risk. As so, the accuracy of structural calculation and quantity take-off when planning the formwork in a construction project are a very important matter. Accordingly, this study develops a BIM based formwork design prototype, that enables the construction manager to optimize the design through applying the proposed new IFC entities associated with the formwork design. The approach proposed in this study is expected to support the construction manager with accurate quantity calculation and rapid planning and construction. Since this study considered specific small-scale buildings using Euro-form and show the possibility of utilizing BIM entities in the formwork design process, further research is recommended towards the limitations in applying the system to other types of formworks.

• Journal of the Korean Institute of Landscape Architecture
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• v.26 no.1
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• pp.96-112
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• 1998

This study aims to evaluate the potential of pro-environmental application(PEP) in streams conceptualized ecological conservation and recreational use to be in harmony with. The main content of research are to clarify the PEP, to establish the evaluation model, and to evaluate 3 streams(Dongchon, Seokhyunchon, Okchon) in Sunchon city. Researchers introduced 12 evaluation items(water quality, water quantity, vegetation-water area, vegetation conservation, streamscape, neighborhood landscape, stream width, optimum area, nearby landuse, facility in stream, distance from user, obstacle to acces) by 5 scales to evaluate the characteristics of natural and artificial factors in stream area and nearby area. Also to decide the weight of items, researchers surveyed the opinion of 22 landscape architects experienced stream-plan through delphi method. Lastly the pro-environmental potential on streams were calculated by the ecological potential and recreational potential indices to be standardized and indicidual sections in streams were divided 5 grades on the basis of PEP. The result of this study are as follows; 1) The evaluation model of PEP was constructed by 4 steps, such as the decision of weight, the measurement of scale, the calculation of potential indices, the gradation of individual sections in streams. 2) The ecological potential were highly influenced by natural factor such as water quality, vegetation conservation, vegetation-water area, but on the other hand the recreational potential were influenced by optimum area, distance from user, water quantity, obstacle to access. 3) The factors such as vegetation conservation, optimum area, nearby landuse, distance from user were function as discernment factors to evaluate relatively ecological and recreational potential. and water quality, water quantity, vegetation -water area, neighborhood landscape were acted as important items to decide PEP.

• The KIPS Transactions:PartA
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• v.16A no.6
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• pp.473-480
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• 2009

This paper is to enhance a color image running in the PXA255 ARM processor based on embedded linux environments. Retinex is one of the representative algorithm for image enhancement in the previous research. However, retinex is not suitable the run on the embedded system because of its long processing time. So, we proposed the image enhancement algorithm for embedded system, with less quantity of operation and the effect equivalent to retinex. To achieve this goal, we propose and implement the image enhancement algorithm, which utilizes the image formation model and gamma correction to be effective in a back-light and dark image. The proposed algorithm converts the color space from RGB to HSV, and then V and S channels are processed. In order to optimize the proposed method in the PXA255 ARM processor, quantity of calculation is reduced. The performance of the proposed algorithm was evaluated through qualitative method and quantitative method. The results show that brightness and contrast are improved with less quantity of operation.