• Journal of Magnetics
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• v.18 no.1
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• pp.50-56
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• 2013

In this paper, the 6-switch inverter for the Flux-Reversal Motor (FRM) has been presented and compared to the 4-switch inverter for the FRM, which is more popular in cost effective applications. To analyze the FRM, we adopted the two-dimensional time-stepped voltage source finite element method (FEM) that uses the actual pulse width modulation (PWM) voltage waveforms as the input data. As the FRM characteristic analysis of actual pwm voltage input, the torque ripples and iron losses (eddy current and hysteresis loss) of the FRM can be precisely calculated. With the simulated and experimental results, the performance and limitations of the 4-switch FRM which is the cost effective drive compared to the 6-switch FRM drive are provided in more detail.

• Korean Journal of Computational Design and Engineering
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• v.6 no.4
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• pp.222-228
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• 2001

In the milling operation, the burr can be generated on the intersection of cutting tool and workpiece. Due to burr formation, we expect lower efficiency in the operation and the cost increase. In order to understand the burr formation mechanism in the milling operation on the arbitrary feature, we developed an algorithm to analyse and predict the exit burr formation mechanism. Firstly, the recognition of arbitrary shaped workpiece was done through the CAD data. This data includes point information on the vertices of the workpiece. Secondly, tile CAM data regarding tool geometry, tool path, cutting speed, and material data are retrieved to simulate the actual cutting process. Thirdly, we predict the exit burr formation on the edge of workpiece based on the geometric analysis. Lastly, an algorithm implemented in the Windows environment to visualize the burr formation simulation. With this information, we can predict which portion of workpiece would have the exit burr in advance so that we call manage to find a way to minimize the edit burr formation in the actual cutting.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.33 no.2
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• pp.791-800
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• 2013

Needs for developing a better way of cost estimating process for public construction projects have been widely recognized. Those needs are mainly from the early phases of the project through the construction life cycle due to the its importance to the control process. In contrast to the traditional estimating method based on unit-price references, this research utilized this following process. The first step is analyzing the real cost data from actual cost activities (2000~2010) about the statement of P.S.C(Prestressed Concrete) Box Girder Bridge. The collected data was broken into four categories based on technical construction methods such as I.L.M(Incremental Launching Method), M.S.S(Movable Scaffolding System), F.S.M(Full Staging Method), and F.C.M(Free Cantilever Method). The second, actual design documents including the actual cost estimating documents, drawings and specifications were carefully reviewed to cluster the cost itemized statement from four categories. It was also attempted to seek the proper breakdown of standard works that are responsible for more than 95 percentage in each categories in terms of its cost. The third, this research comes up the index for standard unit materials and unit price of standard work and develops the approximate estimating model applying for the specification(length and breadth of bridges) per square area that the user takes as well as suggests the practical application plan within the original time alloted.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.10 no.10
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• pp.2803-2809
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• 2009

For a successful construction project not only construction engineering and project management technology but also economic evaluation technique is required. Design and construction technologies are necessary to receive a project order. However, construction management technology which can be apply from the project initial phase to the project operation and management phase is required to create a benefit from the project. Construction management technology is one of the effective factors for project success. Economical and efficient cost management from the planning phase influences the project success. This study investigated cost flow and cost factors of domestic Sewage Treatment Plant project for systematic analysis of cost items following the entire project phase. Particularly, data modeling based on domestic Sewage Treatment Equipment maintenance cost DB was performed, and maintenance cost estimation trend line is suggested using Monte carlo Simulation Method to decrease uncertainty of actual results DB and for feasibility study. Korea Academia-Industrial cooperation Society. The Korea Academia-Industrial cooperation Society. The Korea Academia-Industrial cooperation Society. The Korea Academia-Industrial cooperation Society.

• Journal of Korean Academic Society of Home Health Care Nursing
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• v.10 no.1
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• pp.52-57
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• 2003

The purpose of this study was to evaluate appropriateness of home health care travel cost. For the evaluation, investigated the operating costs of vehicles used by home care nurses and then were components of home care nurses's annual salaries. Travel costs were then calculated based on actual travel expenses of home health care service. Actual data of 23 hospital-based home care agencies between July, 2002 to December, 2002 were collected for the analysis of the travel costs. The results of this study are : 1) For home visit, 65% of home care agencies turned out to be using only hospital owned cars, and 17.1% be depending purely on home care nurses' cars. On average, 1.9 cars used for home visit. 2) Out of 89 agencies, 23 agencies responded to the travel cost survey. Total maintenance cost of a car per month was 381,457 won. 3) Average per visit personal expenses of home care nurses during travel time turned out to be 7,124won assuming 8 working hours per day, 4 visits per day, and 30 minuets of travel time for each visit. 4) Total home health care travel cost per visit was 12,069 won, which was the sum of actually paid travel cost of 4,945 won and personal expenses during travel time of 7,124. In conclusion. we reckon that current compensation price of home care nurses' travel is inappropriate because total home health care travel costs of 12,069 won per visit turned out to be 2.1 times of currently prevailing standard compensation price of 5,830 per visit.

• Korean Journal of Food Science and Technology
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• v.25 no.5
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• pp.481-486
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• 1993

A computeized least-cost formulation program was applied to process emulsion-type sausages. The input data in formulation were utilized with the database which had been established in the previous study. The formulation results may provide Korean meat processors with actual examples. Meat-grade system made these examples more useful. The results of manufacturing test were as follows. The actual cohesiveness from manufactured sausages didn't correspond to the predicted values, but increased as the predicted values increased. These gabs caused by the different processing conditions between the model system and the actual processing. Hardness as well as cohesiveness could be used as the desirable index of a sausage texture. Comparing the cohesiveness and hardness of commercial frankfurters with those of test sausages, bind value constraint of $0.16{\sim}0.17$ in this test formula can be utilized for an actual formulation.

• Journal of Korean Society of Transportation
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• v.13 no.3
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• pp.5-17
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• 1995

One of interesting issues in urban land-use and transportation policy is about an unproven belief that imbalances between employment and residential sites strongly influence urban commuting patterns. The purpose of this study si to find how spatial distribution of jobs and housing affects commuting distances in Seoul Metropolitan Area using 1990 Census O-D Data. This study estimates cost-minimizing required commuting distance, given the actual distributions of jobs and housing , and compares required commuting distances with actual commuting distances. One of findings is that the standard urban economic theory explains only 1/3 of actual commuting in the case study area. The policy implication of this study is that jobs-housing balance policy will have only a minor effect on the actual commuting.

• Korean Journal of Construction Engineering and Management
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• v.22 no.3
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• pp.52-60
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• 2021

Due to the significant size of overseas construction projects, the cost overrun has enormous impacts on the financial status of construction companies. The managers' appropriate perception and identification of key risk factors in the construction phase notably affect the performance of projects. However, the actual impacts of risk factors and local manager' s perception of them could be deviated. For this reason, we aim to compare the performance of actual cases and general opinions of responsible practitioners in terms of risk factors relevant to cost overruns in order to present a practical strategy for risk management. Firstly, factors classified from literature review were used to simulate 290 cost overruns data sets from 20 cases by introducing Monte-Carlo Simulation and were ranked by standardized coefficients through multiple regression analysis. Secondly, a survey was conducted against 42 local managers to rank their perception of impact on cost overrun with identical factors by using Stepwise Weight Assessment Ratio Analysis (SWARA). Comparison results show that conflicts such as 'conflict with subcontractors' and 'conflict with the local community' have caused excessive cost overrun. However, managers' perception of these as less significant than the actual influences and consider other risks such as 'material price fluctuation' and 'construction quality errors', as relatively serious. Therefore, education for local managers on conflict risks needs to be presented.

• Journal of the Korean Institute of Landscape Architecture
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• v.50 no.4
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• pp.20-36
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• 2022

This study aims to provide basic data for high-quality street tree management by setting reasonable management items and appropriate unit prices by reviewing the adequacy of current street tree management. Currently, street tree management items, except for street tree pruning, use general landscape tree quantity per unit for the street tree management quantity per unit. KEPCO (Korea Electric Power Corporation) applied pruning items from standard electric production infrastructure and carried out the activities at an average unit price of 51% lower for heavy pruning and 39% lower for light pruning than the standard estimate. This was judged to be a level that could not maintain or increase the quality of street tree management. It was determined that an appropriate standard unit price for street tree management was necessary. To improve the quantity per unit for the proper management of street trees, it was necessary to review costs in the field. However, due to the absence of data on actual construction costs in the domestic landscape field, detailed items of the US RSMeans Building Construction Cost Data (RSMeans) were reviewed, and the actual construction costs were calculated by applying personal domestic expenses. As a result, the standard of the estimated unit showed a good ratio of 107% for heavy pruning of street tree pruning compared to the actual construction cost, but light pruning was underestimated with a 59% ratio. Shrub pruning was 82%, weeding was 92%, tree fertilization was 87%, and windbreak wall installation was 91% under-engineered. In addition, it was also confirmed that the watering by sprinkler trucks and chemical spraying were over-designed compared to the actual construction cost at the rates of 118% and 124%, respectively. Due to the specificity of the street trees, the increase in personal expenses and the input cost of equipment, such as road safety controls, were judged to be the main cause of the underestimation of items. Therefore, it is necessary to add items related to street trees and general landscape trees to the landscape maintenance items of the standard of the estimated unit.

• IE interfaces
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• v.15 no.3
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• pp.279-285
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• 2002

A break-even analysis is a method used widely for profit planning or decisions in most companies. It is useful tool in financial studies because it is simple and offers useful insights from a modest amount of data. Although it is widely used, it has some weaknesses. It is limited in particular to the analysis for a short term time horizon or one period. We suggest a new break-even procedure to analyze projects with a long term time horizon as keeping the simplicity of a conventional break-even analysis. We will make efforts doing to include actual data for a cost or an income as much as possible rather than developing a mathematical model to improve unreality of a traditional break-even analysis. Also, we will use the spreadsheet software to solve problems.