• Journal of Applied Reliability
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• v.2 no.1
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• pp.15-22
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• 2002

This paper is concerned about an Accelerated Life Test for Micro Display Device which is being used in a Projection TV, in order to find a failure mode occurred in field in a short time, to identify a major factor to affect a life, and to estimate a mean life. For this purpose, we selected a temperature as a accelerated factor to perform a test and measured degradation of display device using visual inspection and chromaticity table. In the result of Accelerated Life Test, it is confirmed that failure mode is equal to the degradation of display device by vendor and the Temperature is a major factor to affect a failure. Besides, according as the display device is turned to green as degraded, it is identified that the change of the chromaticity value is one method to measure the degree of the degradation . So, we applied the optimal condition, which consider a cost and life to lower the Temperature which is a major factor acquired by the result of ALT, to PTV design

• International Journal of Fluid Machinery and Systems
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• v.3 no.4
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• pp.369-378
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• 2010

The creation of the hydraulic turbine flow factor map will undoubtedly benefit its design by decreasing both the design cycle time and product cost. In this paper, the geometry and flow variables, which effectively affect the flow factor, are proposed, analyzed and determined. These flow variables are further used to create the operating condition maps by using different model approaches categorized into Response Surface Method (RSM) and Artificial Neural Network (ANN). The accuracies of models created by different approaches are compared and the performances of model approaches are analyzed. The influences of chosen variables and the combination of Principle Component Analysis (PCA) and model approaches are also studied. The comparison results between predicted and actual flow factors suggest that two-hidden-layer Feed-forward Neural Network (FFNN), and one.hidden-layer FFNN with PCA has the best performance on forming this mapping, and are accurate sufficiently for hydraulic turbine design.

• Journal of the Korea Institute of Building Construction
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• v.9 no.6
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• pp.105-111
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• 2009

Construction equipment is a very important factor for successful construction. Also, the cost for construction equipment is a major part of the cost of construction. Therefore, the estimation of the equipment cost is a critical task in construction planning. A formula for production rates shown in 'Standard Unit Labor' has been used to estimate construction equipment capability and cost. Although the performance of the equipment has improved over time, the variables in the formula have not been updated in a timely manner. Therefore, this paper has analyzed the preceding research, and performed several site visits to measure the cycle time of a backhoe and a loader. Construction equipment production rates were calculated with collected cycle times and variables given in 'Standard Unit Labor'. In addition,production rates were estimated considering the circumstances of various sites with the simulation program 'crystal ball.'

• Journal of KIISE:Information Networking
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• v.29 no.1
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• pp.86-96
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• 2002

In video conferencing system using H.263 encoding and decoding time is as important as compression rate is. To reduce encoding time, a number of methods were proposed. We use a method of them that reduces the computational complexity in motion estimation. The complexity is determined by three factors, such as a cost function, a search range parameter, and a motion search algorithm. In fact, it takes a lot of time to encode the video data on account of the cost function factor. That's the reason that we use the factor to reduce encoding time. In this paper, we tried to reduce total encoding time by reducing the number of calling the cost function. In case of a little moving, our algorithm enabled faster motion searching than TSS(Three Step Search) and NTSS(New TSS). Here, we called the algorithm by an ITSS(Improved TSS) that improves a shortcoming of NTSS requiring more checkpoints than TSS. For an experimentation, our algorithm was compared to other algorithms using PSNR, file size and SAD call times.

• Journal of Internet Computing and Services
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• v.13 no.3
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• pp.31-47
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• 2012

The mobile Virtual Private Network (MVPN) of Internet Engineering Task Force (IETF) is not designed to support NEwork MObility (NEMO) and is not suitable for real-time applications. Therefore, an architecture and protocol which supports VPN in NEMO are needed. In this paper, we proposed the cost-reduced secure mobility management scheme (CR-SeMMS) which is designed for real-time applications in conjunction with VPN and also which is based on the session initiation protocol (SIP). Our scheme is to support MVPN in NEMO, so that the session is well maintained while the entire network is moved. Further, in order to reduce the authentication delay time which considers as a delaying factor in hands-off operations, the signaling time which occurs to maintain the session is shortened through proposing the hands-off scheme adopting an authentication method based on HMAC based One Time Password (HOTP). Finally, our simulation results show the improvement of the average hands-off performance time between our proposed scheme and the existing schemes.

• Journal of Korean Society for Quality Management
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• v.31 no.4
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• pp.176-183
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• 2003

The concept of cost of quality has become important economic measures of quality issues for several decades. Most of the research to date has focused on the problem and solution under static business conditions. However, some researchers have found that prevention cost of COQ is one of the expenses of investment and the payback will be shown by the improvement of product quality. These approaches have considered cost of quality issues based on a time factor. It means that there is a trade­off between prevention/appraisal costs and failure costs. Based on a capital budgeting approach, this research reviews the economics of quality improvement activities and proposes the decision criteria to justify quality improvement activities.

• Journal of the Korean Operations Research and Management Science Society
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• v.20 no.1
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• pp.85-99
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• 1995

Increasingly, risk analysis is becoming important ingredients in achieving the successful implementation and application in the area of the project management. The project management system is designed to manage or control the project resources on a given activity within time, cost and performance so called TPPM (Total Productive Project Management). In this research, a risk analysis model misproposed to identify potential problem areas, quantify the risks, and generated the chice of the action that can be taken to reduce the risk. In addition two analysis models are proposed : 1) risk factor model and 2) network simulation model using VERT (Venture Evaluation and Review Technique ). The objective of the remodels is to estimate the schedule, cost performance risks. These proposed quantitative models for project risk analysis are proving its value for the project managers who need to assess the risk of changes in cost, schedule, or performance. The proposed models will be used in the area of project selection, evaluation and the allocation of project resources.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.28 no.1
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• pp.29-34
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• 2016

The friction factor unit was studied to find a more economic alternative compared to the conventional 30 mmAq/m. The pipe and pump for cooling water piping used in a failing were selected, and the friction factor unit was changed to calculate the pipe diameter and the brake shaft power. Based on current electric charges, After the brake shaft power was converted into operational costs based on current electric charges, then an economic analysis was conducted considering that incorporated the initial installation costs and operational costs for the pump. We found that the friction factor unit when using 20 mmAq/m is more economical than that with 30 mmAq/m, if the piping is used for more than 4 years. The small friction factor unit is desirable when the piping is used for quite a long period of time, and the selection of a more economic friction factor unit should considering the period of usage will be important.

• The Journal of Asian Finance, Economics and Business
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• v.6 no.2
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• pp.63-73
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• 2019

The paper aims to investigate relationships between technology and innovation management, total factor productivity and economic growth in China. By comparing the trends in total factor productivity growth of industrialized economies (i.e. OECD), this study intends to showcase the importance of total factor productivity progress in the Chinese economy. The study employs time series data of an annual basis for the period from 1977 to 2016 retrieved from the World Development Indicator. The study employs unit root test, cointegration test, fully modified least squares estimation method, canonical cointegrating regression and dynamic least squares estimation method to test the hypotheses. The results of the cointegrating regression analysis show that manufacturing growth leads to an increase of total factor productivity in the short-run in China. The findings of the study suggest that manufacturing (i.e. technology and product innovation) is positively related to the increase of total factor productivity in the short-run and total output growth in the long-run. The findings suggest that promoting technology and innovation management and supporting R&D subsidies may reduce the marginal cost of conducting R&D and increase the rate of technology and innovation management and R&D activity and therefore, the total factor productivity growth rate.

• Earthquakes and Structures
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• v.20 no.1
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• pp.13-27
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• 2021

A new seismic design methodology has been developed for precast concrete diaphragms. Seismic design factors were used to be applied on top of diaphragm seismic design forces in the current code. These factors, established through extensive parametric studies, align diaphragm design strengths with different seismic performance targets. A simplified evaluation structure with a single-bay plan was used in the parametric studies. This simplified evaluation structure is reasonable and cost-effective as it can comprehensively cover structural geometries and design parameters. However, further verification and investigation are required to apply these design factors to prototype structures with realistic layouts. This paper presents diaphragm design of several precast concrete office buildings using the new design methodology. The applicability of the design factor to the office building was evaluated and verified through nonlinear time history analyses. The seismic behavior and performance of the diaphragm were investigated for the precast concrete office buildings. It was found that the design factor established for the new design methodology is applicable to the realistic precast concrete office buildings.