• Korean Journal of Computational Design and Engineering
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• v.8 no.2
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• pp.101-108
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• 2003

Presented in this paper is the development of an product cost estimation system at the product design stage. The efficient cost estimation function at the design stage is essential for the cost reduction activities through the entire product life cycle. For this purpose, it is necessary to establish a systematic working procedure, and to develop information system for managing a great deal of production and product-related data required for the cost estimation. The developed system has the capability of estimating a cost of assembly type products as well as unit-item type products. As proposed system is based on the variant approach, it can be used easily at an early design stage without the need for detail design information. Also, this system is integrated with legacy PDM (Product Data Management) and ERP (Enterprise Resource Planning) system for fast. accurate and easy product cost estimation. The estimated cost includes material cost, overhead cost as well as labor cost.

• Water Engineering Research
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• v.2 no.4
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• pp.219-229
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• 2001

Synthetic unit hydrograph equations for rainfall run-off characteristics analysis and estimation of design flood have long and quite frequently been presented, the Snyder and SCS synthetic unit hydrograph. The major inputs to the Snyder and SCS synthetic unit hydrograph are lag time and peak coefficient. In this study, the methods for estimating lag time and peak coefficient for small watersheds proposed by Zhao and McEnroe(1999) were applied to the Kum river basin in Korea. We investigated lag times of relatively small watersheds in the Kum river basin in Korea. For this investigation the recent rainfall and stream flow data for 10 relatively small watersheds with drainage areas ranging from 134 to 902 square kilometers were gathered and used. 250 flood flow events were identified along the way, and the lag time for the flood events was determined by using the rainfall and stream flow data. Lag time is closely related with the basin characteristics of a given drainage area such as channel length, channel slope, and drainage area. A regression analysis was conducted to relate lag time to the watershed characteristics. The resulting regression model is as shown below: ※ see full text (equations) In the model, Tlag is the lag time in hours, Lc is the length of the main river in kilometers and Se is the equivalent channel slope of the main channel. The coefficient of determinations (r$^2$)expressed in the regression equation is 0.846. The peak coefficient is not correlated significantly with any of the watershed characteristics. We recommend a peak coefficient of 0.60 as input to the Snyder unit-hydrograph model for the ungauged Kum river watersheds

• Journal of Environmental Science International
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• v.24 no.4
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• pp.437-447
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• 2015

Estimation of runoff peak is needed to assess water availability, in order to support the multifaceted water uses and functions, hence to underscore the modalities for efficient water utilization. The magnitude of storm rainfall acts as a primary input for basin level runoff computation. The rainfall-runoff linkage plays a pivotal role in water resource system management and feasibility level planning for resource distribution. Considering this importance, a case study has been carried out in the Hancheon basin of Jeju Island where distinctive hydrological characteristics are investigated for continuous storm rainfall and high permeable geological features. The study aims to estimate unit hydrograph parameters, peak runoff and peak time of storm rainfalls based on Clark unit hydrograph method. For analyzing observed runoff, five storm rainfall events were selected randomly from recent years' rainfall and HEC-hydrologic modeling system (HMS) model was used for rainfall-runoff data processing. The simulation results showed that the peak runoff varies from 164 to 548 m3/sec and peak time (onset) varies from 8 to 27 hours. A comprehensive relationship between Clark unit hydrograph parameters (time of concentration and storage coefficient) has also been derived in this study. The optimized values of the two parameters were verified by the analysis of variance (ANOVA) and runoff comparison performance were analyzed by root mean square error (RMSE) and Nash-Sutcliffe efficiency (NSE) estimation. After statistical analysis of the Clark parameters significance level was found in 5% and runoff performances were found as 3.97 RMSE and 0.99 NSE, respectively. The calibration and validation results indicated strong coherence of unit hydrograph model responses to the actual situation of historical storm runoff events.

• Journal of Korean Home Economics Education Association
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• v.19 no.3
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• pp.91-106
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• 2007

The purpose of this study was to provide the information for the development of gender-equality oriented content of Technology Home Economics subject. For this purpose, a total of 404 male and female middle high school students in Chuncheon city were sampled and asked to estimate the degree of practical use and preference for the 47 units of Technology Home Economics subject. Results were summarized as following : 1. The 47 units were classified into 4 groups on the basis of similarity in the degree of practical use and preference: 23 units estimated as 'better than average' by male and female students were classified into group 1; 4 units estimated as 'better than average' by female students but as 'less than average' by male students were classified into group 2; 10 units estimated as 'less than average' by male and female students were classified into group. 3; 10 units estimated as 'far less than average' by male and female students were classified into group 4. Most of the units in Home Economics area were classified Into group 1 or 2, but most of the units in Technology area were classified into group 3 or 4. 2. Gender difference was confirmed between male and female students' estimation of the degree of practical use and preference for the 47 units. In about three-quaters of the units in Home Economics area, female students' estimation of the degree of practical use and preference was higher than male students' estimation. In about half of the units in Technology area, male students' estimation of the degree of practical use and preference was higher than female students' estimation. However, possibility was detected in several units of Technology Home Economics subject that gender difference could be decreased.

• Journal of Korean Society of Forest Science
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• v.4 no.1
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• pp.26-29
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• 1965

1. The purpose of this study was to find out the best sampling form and sampling unit in forest survey. 2. The value of small sampling unit was over estimated in comparison with that of large sampling unit. 3. The value of circular form was over estimated in comparison with that of the others. 4. The smallest unit for estimation in area sampling were as follows. a) 0.06 ha. in the rectangular plot. b) 0.08 ha. in the square plot. c) 0.10 ha. in the circular plot. 5. Conclusion was as follows. The best sampling unit was 0.06 hectoare in the rectangular plot, which was most economic above all and gave preferable result for in the forest survey.

• IEIE Transactions on Smart Processing and Computing
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• v.4 no.1
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• pp.16-21
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• 2015

Most video services are transmitted in wireless networks. In a network environment, a packet of video is likely to be lost during transmission. For this reason, numerous error concealment (EC) algorithms have been proposed to combat channel errors. On the other hand, most existing algorithms cannot conceal the whole missing frame effectively. To resolve this problem, this paper proposes a new Adaptive Prediction Unit-based Motion Vector Extrapolation (APMVE) algorithm to restore the entire missing frame encoded by High Efficiency Video Coding (HEVC). In each missing HEVC frame, it uses the prediction unit (PU) information of the previous frame to adaptively decide the size of a basic unit for error concealment and to provide a more accurate estimation for the motion vector in that basic unit than can be achieved by any other conventional method. The simulation results showed that it is highly effective and significantly outperforms other existing frame recovery methods in terms of both objective and subjective quality.

• Proceedings of the IEEK Conference
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• 1998.06a
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• pp.717-720
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• 1998

In this paper, we propose a VLSI architecture for implementing a crecently proposed fast block matching algorithm, which is called the HSBMA3S. The proposed architecture consists of a systolic array based basic unit and two shift register arrays. And it covers a search range of -32 ~+31. By using a basic unit repeatedly, we can redcue the number of gates. To implement the basic unit, we can select one among various conventional systolic arrays by trading-off between speed and hardware cost. In this paper, the architecture for the basic unit is selected so that the hardware cost can be minimized. The proposed architecture is fast enough for low bit-rate applications (frame size of 352x288, 30 frames/sec) and can be implemented by less than 20,000 gates. Moreover, by simply modifying the basic unit, the architecture can be used for the higher bit-rate application of the frame size of 720*480 and 30 frames/sec.

• Journal of the Korean Statistical Society
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• v.24 no.2
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• pp.481-493
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• 1995

An ARIMA signal observed with measurement error is shown to have another ARIMA representation with nonlinear restrictions on parameters. For this model, the restricted Newton-Raphson estimator(RNRE) of the unit root is shown to have the same limiting distribution as the ordinary least squares estimator of the unit root in an AR(1) model tabulated by Dickey and Fuller (1979). The RNRE of parameters of the ARIMA(p,1,k) process and unit root tests base on the RNRE are developed.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2011.05a
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• pp.187-189
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• 2011

Standard production unit system has been used as accumulated standard for the cost estimation of public construction projects. However, it is difficult to estimate reasonable cost due to adaptation of a uniform standard and reflect changes in the technology. The purpose of this study is to provide basic data for improvement of standard production unit system through the identifying problems and analysing its influence on enactment and/or revision work of standard production unit system.

• Communications for Statistical Applications and Methods
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• v.22 no.6
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• pp.615-624
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• 2015

We consider the estimation of seasonal cointegration in the presence of conditional heteroskedasticity (CH) using a feasible generalized least squares method. We capture cointegrating relationships and time-varying volatility for long-run and short-run dynamics in the same model. This procedure can be easily implemented using common methods such as ordinary least squares and generalized least squares. The maximum likelihood (ML) estimation method is computationally difficult and may not be feasible for larger models. The simulation results indicate that the proposed method is superior to the ML method when CH exists. In order to illustrate the proposed method, an empirical example is presented to model a seasonally cointegrated times series under CH.