• Journal of Environmental Impact Assessment
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• v.15 no.2
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• pp.101-109
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• 2006

Water quality simulation models include the difference between the measured and estimated values as an inevitable consequence because they represent the complicated natural phenomena as simplified mathematical equations. The major reason of the difference occurrence is due to the use of the imprecise values of the model parameters, but the parameter values are currently determined by the try and error method directly performed by humans. However, the use of this method requires many time and endeavor of humans, and generally does not obtain the most suitable parameter values. A method for deciding model parameter values is, therefore, developed in this study. The method minimizes the difference between the measured and estimated values and also distributes uniformly the measured values on the upper and lower sides of the line representing the estimated values. A user interface based on this method is also developed by using the Visual Basic 6.0 of Microsoft, and it can be operated in the environment of Windows 98/2000. In this study, the method for deciding model parameter values is applied for estimating the water quality of the stream Ko-heung. The results of the application show that the method, including its computer program, can effectively obtain the most suitable parameter values and also save many working time in comparison with the existing method directly performed by humans.

• IE interfaces
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• v.18 no.3
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• pp.317-326
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• 2005

Staff scheduling is an important area, both from an academic and industrial point of view. It has become increasingly important as business becomes more service oriented and cost conscious in a global environment. There has been a lot of study to develop new and efficient staff scheduling models and methods. The purpose of this paper is not to develop new theoretical results but to develop a comprehensive user-friendly staffing model that can be applied to the real-world practice. The developed staffing software, OptStaff, provides the optimal configuration of the customer support center including the selection of customer support center locations, the allocation of staffs to each selected location, and schedules of staffs, so as to minimize the total cost while maximizing the customer satisfaction level. OptStaff also has capability to do scenario analysis by varying the levels of parameters and to create a variety of graphs and reports with user-friendly interfaces.

• Proceedings of the Korean Society for Agricultural Machinery Conference
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• 1996.06c
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• pp.228-237
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• 1996

On the basis of a brief introduction of the mechanized dry farming in Heilongjiang Province, the author states the developing process from the combination of single technics of farm machinery and agronomy to the technical assembly of high yield cultivation technics and its mathematical expression. According to the main temperature accumulated zones, 5 typical comprehensive technical assembly models for the mechanized cultivation technics and their agricultural machinery systems have been listed. They are, the Heihe " 261" wheat and soybean model : the Yi'an big ridge double row film mulching corn model : the Yongchang high yield mechanized soybean and other grain crops six year rotation model for Keshan state farms. The author conclude that the application of mechanized high yield cultivation technical assembly is the key point to transform the Heilongjiang province from big agriculture to strong agriculture, we have to take " high yield , high quality , high efficiency , s stain -ability and earning foreign currency" as the general target and carry out the corresponding policy and measures for the further development of agricuture.

• Proceedings of the Korea Water Resources Association Conference
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• 2004.05b
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• pp.563-567
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• 2004

During drought season, the self-purification capacities of the four major rivers in Korea are significantly controlled by environmental maintenance flows supplied from the mid- or upstream large dams. Therefore, it is obviously important to operate the dams considering not only water quantity aspects but also conservation of downstream water quality and aquatic ecosystems. Mathematical water quality models can be efficiently used to serve as a decision support tool for evaluating the effects of operational alternatives of upstream dams on the downstream aquatic environment. In this study, an unsteady one-dimensional water quality model, KORIV1-WIN was developed based on the theoretical and numerical algorithms for hydrodynamics and water quality simulations of CE-QUAL-RIV1. It consists of hydrodynamic(KORIV1H) and water quality(KORIV1Q) modules, and pre- and post-processors for input data preparations and output displays. The model can be used to predict one-dimensional hydraulic and water quality variations in rivers with highly unsteady flows such as dam outflow change, rainfall-runoff, and chemical spill events.

• Journal of the Ergonomics Society of Korea
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• v.28 no.3
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• pp.1-6
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• 2009

Recently, importance of the rehabilitation of hand pathologies as well as the development of high-technology hand robot has been increased. The biomechanical model of hand is indispensable due to the difficulty of direct measurement of muscle forces and joint forces in hands. In this study, a three-dimensional biomechanical model of four fingers including three joints and ten muscles in each finger was developed and a mathematical relationship between neural commands and finger forces which represents the enslaving effect and the force deficit effect was proposed. When pressing a plate under the flexed posture, the muscle forces and the joint forces were predicted by the optimization technique. The results showed that the major activated muscles were flexion muscles (flexor digitorum profundus, radial interosseous, and ulnar interosseous). In addition, it was found that the antagonistic muscles were also activated rather than the previous models, which is more realistic phenomenon. The present model has considered the interaction among fingers, thus can be more powerful while developing a robot hand that can totally control the multiple fingers like human.

• Journal of the Korea Society of Computer and Information
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• v.10 no.4 s.36
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• pp.57-63
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• 2005

An accurate system modeling in the underground water analysis requires many accurate parameters on the spot, which have a huge volume, because it may be generated more inaccurate products than to use mathematical analytical solution in a case that a degree of permeation, undercurrent coefficients, boundary conditions, and so on, are inadequately estimated. Recently, handling these parameters easily has been an active area of research. In this paper, we propose a new method which handles these parameters easily and accurately for a system model management using a well-known MODFLOW model. Also, we incorporate this method into ArcView functions. Results of the proposed system incorporated into ArcView are displayed visually.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.26 no.6C
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• pp.421-429
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• 2006

This study was undertaken to develop an analysis model representing a reliable estimation of rigidity of Korean soft clay using an artificial neural network (ANN). Data for the model development were obtained through a laboratory study, and were used for training and verification. The coefficient of correlation between the measured and predicted data using the developed model was relatively high. It demonstrates the potential application of ANN for the reliable estimation of Korean soft clay rigidity while past attempts at building such a mathematical model have proved difficult.

• Journal of Information Processing Systems
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• v.18 no.3
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• pp.359-373
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• 2022

The new crown pneumonia (COVID-19) has become a global epidemic. The disease has spread to most countries and poses a challenge to the healthcare system. Contact tracing technology is an effective way for public health to deal with diseases. Many experts have studied traditional contact tracing and developed digital contact tracking. In order to better understand the field of contact tracking, it is necessary to analyze the development of contact tracking in the field of computer science by bibliometrics. The purpose of this research is to use literature statistics and topic analysis to characterize the research literature of contact tracking in the field of computer science, to gain an in-depth understanding of the literature development status of contact tracking and the trend of hot topics over the past decade. In order to achieve the aforementioned goals, we conducted a bibliometric study in this paper. The study uses data collected from the Scopus database. Which contains more than 10,000 articles, including more than 2,000 in the field of computer science. For popular trends, we use VOSviewer for visual analysis. The number of contact tracking documents published annually in the computer field is increasing. At present, there are 200 to 300 papers published in the field of computer science each year, and the number of uncited papers is relatively small. Through the visual analysis of the paper, we found that the hot topic of contact tracking has changed from the past "mathematical model," "biological model," and "algorithm" to the current "digital contact tracking," "privacy," and "mobile application" and other topics. Contact tracking is currently a hot research topic. By selecting the most cited papers, we can display high-quality literature in contact tracking and characterize the development trend of the entire field through topic analysis. This is useful for students and researchers new to field of contact tracking ai well as for presenting our results to other subjects. Especially when comprehensive research cannot be conducted due to time constraints or lack of precise research questions, our research analysis can provide value for it.

• Communications of Mathematical Education
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• v.35 no.4
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• pp.475-504
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• 2021

This study is a study that developed class materials that can be applied directly to classes by field teachers in consideration of ' research on the development is valuable as a field support study.', 'In material development, organizing data centering on the knowledge composition and inquiry activities of characters related to the mathematics concept can help develop class materials', and 'The fact that the development of subject data for has been insufficient'. To this end, this study went through the procedure of 'establishing a data development plan, data development, verifying field teachers on development data, verifying subject experts on development data, and developing final data reflecting verification opinions.' Therefore, based on the 1st 50 minutes reflecting the task exploration model, it was possible to develop class materials for the 3rd time. In this study, development data were presented with a 17-week curriculum plan, a class guidance plan that presents teacher-student interaction, and a task development form that students fill out and submit in class. This study was developed with the developed data in mind to be applied to actual classes. Therefore, a follow-up study is needed to apply the developed data to actual classes and analyze the results.

• Journal of the Korean Wood Science and Technology
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• v.43 no.3
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• pp.311-319
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• 2015

Near infrared (NIR) reflectance spectroscopy was employed to develop moisture content prediction model of pitch pine (Pinus rigida), red pine (Pinus densiflora), Korean pine (Pinus koraiensis), yellow poplar (Liriodendron tulipifera) wood below fiber saturation point. NIR reflectance spectra of specimens ranging from 1000 nm to 2400 nm were acquired after humidifying specimens to reach several equilibrium moisture contents. To determine the optimal moisture contents prediction model, 5 mathematical preprocessing methods (moving average (smoothing point: 3), baseline, standard normal variate (SNV), mean normalization, Savitzky-Golay $2^{nd}$ derivatives (polynomial order: 3, smoothing point: 11)) were applied to reflectance spectra of each specimen as 8 combinations. After finishing mathematical preprocessings, partial least squares (PLS) regression analysis was performed to each modified spectra. Consequently, the mathematical preprocessing methods deriving optimal moisture content prediction were 1) moving average/SNV for pitch pine and red pine, 2) moving average/SNV/Savitzky-golay $2^{nd}$ derivatives for Korean pine and yellow poplar. Every model contained three principal components.