• The Journal of Korean Institute of Communications and Information Sciences
• /
• v.25 no.9A
• /
• pp.1452-1460
• /
• 2000

A series of papers in recent literature on logical topology design for wavelength routed optical networks have proposed mathematical models and solution methods unifying logical topology design wavelength assignment and traffic routing. The most recent one is by Krishnaswamy and Sivarajan which is more unifying and complete than the previous models. Especially the mathematical formulation is an integer linear program and hence regarded in readiness for an efficient solution method compared to the previous nonlinear programming models. The solution method in [7] is however elementary one relying on the rounding of linear program relaxation. When the rounding happens to be successful it tends to produce near-optimal solutions. In general there is no such guarantee so that the obtained solution may not satisfy the essential constraints such as logical -path hop-count and even wavelength number constraints. Also the computational efforts for linear program relaxation seems to be too excessive. In this paper we propose an improved and unifying solution method based on the same to be too excessive. In this paper we propose an improved and unifying solution method based on the same model. First its computation is considerably smaller. Second it guarantees the solution satisfies all the constraints. Finally applied the same instances the quality of solution is fairly competitive to the previous near optimal solution.

• The Journal of Korean Obstetrics and Gynecology
• /
• v.25 no.3
• /
• pp.132-148
• /
• 2012

Objectives: The aim of this study was to evaluate the effectiveness of dysmenorrhea care program by Korean traditional medicine on dysmenorrhiec juveniles. Methods: 47 adolescent dysmenorrhiec patients in local girls' high school took part in dysmenorrhea care program by Korean traditional medicine. The subjects were treated by acupuncture, ear-acupuncture, acupressure education, herbal extract medication and qigong exercise. The results were investigated by visual analogue scale(VAS), multidimensional verbal rating scale(MVRS) and verbal rating scale (VRS). Data was collected every three months from March, 2011 to March, 2012. Additionally satisfaction survey was conducted. Results: VAS score was reduced after treatment, but rebounded back to baseline after 6 months of discontinued dysmenorrhea care program. There was no significant difference of time and group interaction in linear mixed model analysis. MVRS and VRS outcomes showed similar pattern. Conclusions: Dysmenorrhea care program by Korean traditional medicine is effective in juveniles with dysmenorrhea for several months but not for long as nine months after treatment. However, the effect can last for three months at the very least.

• Journal of the Institute of Electronics and Information Engineers
• /
• v.50 no.11
• /
• pp.219-225
• /
• 2013

Program and erase characteristics of the elliptic gate all around (e-GAA) SONOS cell have been studied as the variation of eccentricity of the channel. An analytic program and erase model for the elliptic GAA SONOS cell is proposed and evaluated. The model shows that the ISPP (incremental-step-pulse programming) property is changed non-linearly as the eccentricity of the e-GAA SONOS cell is increased. It is differently from the well known linear relationship for that of 2D SONOS and even 3D circular SONOS cell with program bias. We can find that the simulation results of ISPP characteristics are in accord with the experimental data.

• Genomics & Informatics
• /
• v.19 no.1
• /
• pp.11.1-11.8
• /
• 2021

For the novel coronavirus disease 2019 (COVID-19), predictive modeling, in the literature, uses broadly susceptible exposed infected recoverd (SEIR)/SIR, agent-based, curve-fitting models. Governments and legislative bodies rely on insights from prediction models to suggest new policies and to assess the effectiveness of enforced policies. Therefore, access to accurate outbreak prediction models is essential to obtain insights into the likely spread and consequences of infectious diseases. The objective of this study is to predict the future COVID-19 situation of Korea. Here, we employed 5 models for this analysis; SEIR, local linear regression (LLR), negative binomial (NB) regression, segment Poisson, deep-learning based long short-term memory models (LSTM) and tree based gradient boosting machine (GBM). After prediction, model performance comparison was evelauated using relative mean squared errors (RMSE) for two sets of train (January 20, 2020-December 31, 2020 and January 20, 2020-January 31, 2021) and testing data (January 1, 2021-February 28, 2021 and February 1, 2021-February 28, 2021) . Except for segmented Poisson model, the other models predicted a decline in the daily confirmed cases in the country for the coming future. RMSE values' comparison showed that LLR, GBM, SEIR, NB, and LSTM respectively, performed well in the forecasting of the pandemic situation of the country. A good understanding of the epidemic dynamics would greatly enhance the control and prevention of COVID-19 and other infectious diseases. Therefore, with increasing daily confirmed cases since this year, these results could help in the pandemic response by informing decisions about planning, resource allocation, and decision concerning social distancing policies.

• Water Engineering Research
• /
• v.1 no.2
• /
• pp.137-146
• /
• 2000

A windows-based software package, named DREDGE, is developed for estimating sediment resuspension and contaminant release during dredging operations. DREDGE allows user to enter the necessary dredge information, site characteristics, operational data, and contaminant characteristics, then calculates an array of concentration using the given values. The program mainly consists of the near-field models, which are obtained empirically, for estimating sediment resuspension and the far-field models, which are obtained analytically, for suspended sediment transport. A linear equilibrium partitioning approach is applied to estimate particulate and dissolved contaminant concentrations. This software package which requires only a minimal amount of data consists of three components; user input, tabular output, and graphical output. Combining the near-field and far-field models into a user-friendly windows-based computer program can greatly save dredge operator's, planners', and regulators' efforts for estimating sediment transports and contaminant distribution.

• Proceedings of the KSME Conference
• /
• 2007.05b
• /
• pp.2621-2625
• /
• 2007

This study aims at analyzing the flow characteristics of the electromagnetic pump using a linear induction motor (LIM) for transferring molten metals. The flow characteristics of the pump are simulated by magnetohydrodynamic(MHD) program. In this system, the LIM is used for transferring molten metal by electromagnetic force. The molten metal is treated as the secondary part of the LIM. Since the LIM produces an electromagnetic force in the duct, the molten metal can flow from the furnace to the reservoir. The flow characteristics of the pump are analyzed using MHD program for magnetic field of 0.1[T] in duct. In order to prove the analysis, we made a prototype electromagnetic pump using LIM.

• Journal of the Korean Society for Nondestructive Testing
• /
• v.15 no.4
• /
• pp.520-530
• /
• 1996

In this study, the artificial defects in rotary compressor are classified using pattern recognition of acoustic emission signal. For this purpose the computer program is developed. The neural network classifier is compared with the statistical classifier such as the linear discriminant function classifier and empirical Bayesian classifier. It is concluded that the former is better. It is possible to acquire the recognition rate of above 99% by neural network classifier.

• Journal of Korean Academy of Nursing
• /
• v.29 no.2
• /
• pp.281-292
• /
• 1999

This study was designed to construct a model that predicts the health promoting behavior of the Korean elderly. Data were collected by self-reported questionaires from 254 Korean elderly in seoul, from June 1 to July 15, 1998. Data were analyzed by descriptive statistics and correlational analysis using pc-SAS program. The Linear Structural Modeling(LISREL) 8.0 program was used to find the best fit model which predicts causal relationships of variables. The overall fit of the hypothetical model to the data was moderate［X$^2$＝249.83(df＝83, p＝.00), RMR＝.07, GFI＝.90, NNFI＝.92, NFI ＝.91］. The predictable variables of health promoting behavior of the Korean elderly were social activity. social support. self-integrity and helplessness except the perceived health status. These variables explained 17.1% of health promoting behavior of the Korean elderly.

• International Journal of Precision Engineering and Manufacturing
• /
• v.2 no.2
• /
• pp.17-25
• /
• 2001

In this paper, a theoretical study has been made to reduce the residual stress and birefringence in the injection-molded parts. An optimization program has been used to minimize the residual stresses and birefringence calculated from a simulation program. The thermally induced stress has been calculated using a linear viscoelasticity model. The flow stress and birefringence has been calculated using the Leonov's viscoelasticity model. This has been applied to the injection molding of a circular disc and a plate. the optimization has been done either by changing process variables while maintaining the mold temperature constant or by varying the mold-wall temperature with time. This study shows the significant reduction in residual stress and birefringence is possible through the optimization of processing conditions.

• Proceedings of the Korean Society of Precision Engineering Conference
• /
• 1993.10a
• /
• pp.212-217
• /
• 1993

A 2-dimensional FEM/GEM program was developed for analyzing forming processes of an arbitrarily shaped draw-die, in which plane strain condition is assumed and linear line elements are employed. FEM formulation adopted a new algorithm for solving force equilibrium as well as non-penetration condition simultaneously. For the case of numerical divergence at nearly final forming stages and the initial guess in Newton-Raphson iterations, geometric force equilibrium method(GEM) is also introduced. The developed program was tested with the simulation of stamping processes of automotive bonnet inner pannel in order to verify the usefulness and validity of FEM/GEM formulation.