• Journal of Electrical Engineering and Technology
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• v.5 no.2
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• pp.179-190
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• 2010

This paper describes a new stochastic heuristic algorithm in engineering problem optimization especially in power system applications. An improved particle swarm optimization (PSO) called adaptive particle swarm optimization (APSO), mixed with simulated annealing (SA), is introduced and referred to as APSO-SA. This algorithm uses a novel PSO algorithm (APSO) to increase the convergence rate and incorporate the ability of SA to avoid being trapped in a local optimum. The APSO-SA algorithm efficiency is verified using some benchmark functions. This paper presents the application of APSO-SA to find the optimal location, type and size of flexible AC transmission system devices. Two types of FACTS devices, the thyristor controlled series capacitor (TCSC) and the static VAR compensator (SVC), are considered. The main objectives of the presented method are increasing the voltage stability index and over load factor, decreasing the cost of investment and total real power losses in the power system. In this regard, two cases are considered: single-type devices (same type of FACTS devices) and multi-type devices (combination of TCSC, SVC). Using the proposed method, the locations, type and sizes of FACTS devices are obtained to reach the optimal objective function. The APSO-SA is used to solve the above non.linear programming optimization problem for better accuracy and fast convergence and its results are compared with results of conventional PSO. The presented method expands the search space, improves performance and accelerates to the speed convergence, in comparison with the conventional PSO algorithm. The optimization results are compared with the standard PSO method. This comparison confirms the efficiency and validity of the proposed method. The proposed approach is examined and tested on IEEE 14 bus systems by MATLAB software. Numerical results demonstrate that the APSO-SA is fast and has a much lower computational cost.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.31 no.4
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• pp.267-271
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• 2018

A high directivity TIR (total internal reflection) lens in the UV-A region was designed using a silicone resin, and a UV light source module with a maximum irradiation density of $150mW/cm^2$ was fabricated. The beam angle of the TIR lens was designed to be $8.04^{\circ}$ and the maximum diameter of the TIR lens was Ø13.5. A silicone resin having a UV transmittance of 93% and a refractive index of 1.4 at a wavelength of 365 nm was used, and the lens was manufactured using an aluminum mold, from which silicone could be easily released. The module was fabricated in a metal printed circuit board of COB (chip on board) type using a $0.75{\times}0.75mm^2$ UV chip. A jig was used to adjust the focal length between lens and chip and to fix the position of the lens. The optical characteristics such as illumination distributions of the lens and module were designed using 'LightTools' optical simulation software. The heat dissipation system was designed to use a forced-air cooling method using a heat-sink and fan.

• Korean Journal of Community Nutrition
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• v.19 no.2
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• pp.176-186
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• 2014

Objectives: Epidemiological studies have suggested that a higher consumption of whole grain foods can significantly reduce the risk of chronic diseases including cardiovascular diseases, type 2 diabetes and obesity. The objective of the current study was to examine associations among the consumption of whole grains and nutrient intakes and biochemical indicators associated with chronic diseases among generally healthy middle-aged Korean women. Methods: Using 24-hour recall data from the 2008-2009 National Health and Nutrition Examination Surveys, whole grain intake (g/day) was calculated for a total of generally healthy 1,953 subjects. The subjects were divided into three groups by the level of whole grain consumption (0 g/day, > 0 and < 20 g/day or ${\geq}20g/day$). Mean values or proportions of various nutrient intakes and metabolic risk factors were compared according to the level of whole grain consumption. All statistical analysis was conducted using SAS software version 9.2. Results: We observed that the overall consumption of whole grains was quite low. Specifically, 58.2% of subjects reported no whole grain consumption on the day of the survey, and the mean whole grain intake was only 15.3 g/day. The whole grain consumption was positively associated with intakes of various macro and micronutrients, namely, plant proteins and fats, dietary fiber, calcium, plant iron, potassium, zinc, vitamin A, ${\beta}$-carotene, thiamin, riboflavin, niacin, vitamin $B_6$ and folic acid. In addition, we found significantly decreasing trends in abdominal obesity and hypertriglyceridemia as whole grain intake levels increase. Conclusions: The study findings suggested the importance of promoting whole grain consumption as an efficient tool for improving various dietary aspects and preventing chronic diseases.

• Journal of KIISE:Software and Applications
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• v.34 no.11
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• pp.953-960
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• 2007

To correctly detect muras, visual defects in TFT-LCD panels, image distortion occurring on the profess of capturing panels should be corrected. In general vision systems, there are several known methods to restore the observed image. However, the vignetting effect particularly shown only in panel images cannot be easily restored through traditional methods because it is combined with background non-uniformity due to the unique characteristic of panel. To increase the reliability of image restoration, the vignetting effect should be properly corrected after being separated from image background. Therefore, in this paper we present a new method to analyze and correct the vignetting effect of panel images using principal component analysis. Experimental results for a total of 175 test images showed that the average contrast error of the muras in the distorted images was reduced from 37% to 11% and the mura misidentification rate was decreased from 14.8% to 2.2% by image restoration.

• Restorative Dentistry and Endodontics
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• v.25 no.1
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• pp.78-84
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• 2000

The aim of this study was to compare shaping ability of nickel-titanium rotary files with different taper in simulated resin canals. The instruments used in this study were GT with .04 taper ProFile with ISO-sized tip, .04 taper ProFile with ISO-sized tip alone, and .02 taper Naviflex file and all canals were prepared by crown-down technique. A total of 30 composite images were made from pre- and post-canal scanned images using Scanjet 4C scanner and Corel photopaint 8.0 and then, prevalence of canal aberrations was measured. The amount of coronal substance the instruments removed was also calculated two-dimensionally on digitized images with the Brain C software to compare the relative enlarging efficiency. Finally, the prepared internal canal form was evaluated three-dimensionally with impression technique. The results were as follows; 1. The incidence of zipping in Naviflex group was significantly high compared to the other two groups(P<.05). 2. The amount of coronal substance the GT combined group removed was significantly larger than the other two groups(P<.05). 3. The GT combined group produced canals with good taper and flow. Under the conditionas of this study, the combined use of larger tapered nickel-titanium rotary files prepared simulated canals safely, efficiently and with good three-dimensional form.

• KIPS Transactions on Software and Data Engineering
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• v.7 no.1
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• pp.33-42
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• 2018

The purpose of this study is to suggest the shortcomings and the direction of the web accessibility evaluation studies by analyzing the research trends on web accessibility evaluation in Korea. For this aim, a total of 59 theses presented in the registered academic journal and the candidate of registration academic journals from January 2000 to March 2017 were selected. The selected dissertations have been analyzed based on the evaluators, the evaluation targets, the evaluation methods, and the evaluation results with regard to web accessibility. As a result of the analysis, the highest rate in the evaluator aspect was 'independent evaluation (66 percent)' and the highest percentage in the evaluation target aspect was 'web site (83 percent)'. When it came to the evaluation methods, automatic evaluation and the mixture of automatic evaluation and manual evaluation had a similar percentage. Lastly, only two papers showed that web accessibility did not have any problems. This study is meaningful in the sense that it suggested a desirable direction for the web accessibility studies in Korea and web accessibility evaluation studies in the situation when the meta studies which analyzed research trends are insufficient.

• Proceedings of the KSRS Conference
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• 2003.11a
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• pp.1191-1193
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• 2003

Water quantity and quality monitoring at Taipei Watershed Management Bureau (WRATB) is not only a daily business but also a long term job. WRATB is responsible for providing high quality drinking water to about four millions population in Taipei. The quality of drinking water provided by WRATB is among one of the best in Taiwan. The total area is 717 square kilometers. The water resource pollution is usually divided into two categories, point source pollution and nonpoint source pollution. Garbage disposal is the most important component of the point source pollution, especially those by tourist during holidays and weekends. Pesticide pollution, fertilizer pollution, and natural pollution are the major contributions for nonpoint source pollution. The objective of this paper is to implement remote sensing, geographic information systems, and global positioning systems to monitor water quantity and water quality at WRATB. There are 12 water quality monitoring stations and four water gauge stations at WRATB. The coordinates of the 16 stations were determined by GPS devices and created into the base maps. MapObjects and visual BASIC were implemented to create application modules for water quality and quantity monitoring. Water quality of the two major watersheds at WRATB was put on Internet for public review monthly. The GIS software, ArcIMS, can put location maps and attributes of all 16 stations on Internet for general public review and technical implementations at WRATB. Inquiry and statistic charts automatic manipulations for the past 18 years are also available. Garbage disposal by community and tourist were also managed by GIS and GPS. The storage, collection, and transportation of garbage were reviewed by ArcMap file format. All garbage cart and garbage can at WRATB can be displayed on the base maps. Garbage disposal by tourist during holidays and weekends can be managed by a PDA with a GPS device and a digital camera. Man power allocation for tourist garbage disposal management can be done in an integration of GIS and GPS. Monitoring of water quality and quantity at WRATB can be done on Internet and by a PDA.

• Restorative Dentistry and Endodontics
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• v.40 no.1
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• pp.44-49
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• 2015

Objectives: This study compared the ability of several techniques to remove calcium hydroxide (CH) from the root canal and determined the influence of CH residues on the accuracy of the electronic apex locator. Materials and Methods: Root canals of 90 human maxillary lateral incisors with confirmed true working length (TWL) were prepared and filled with CH. The teeth were randomly assigned to one of the experimental groups according to the CH removal technique (n = 14): 0.9% saline; 0.9% saline + master apical file (MAF); 17% ethylenediamine tetraacetic acid (EDTA); 17% EDTA + MAF; 5.25% sodium hypochlorite (NaOCl); 5.25% NaOCl + MAF. Six teeth were used as negative control. After CH removal, the electronic working length was measured using Root-ZX (Morita Corp.) and compared with TWL to evaluate Root-ZX accuracy. All specimens were sectioned longitudinally, and the area of remaining CH (CH) and total canal area were measured using imaging software. Results: The EDTA + MAF and NaOCl + MAF groups showed better CH removal than other groups (p < 0.05). Root-ZX reliability to prevent overestimated working length to be > 85% within a tolerance of ${\pm}1.0mm$ (p < 0.05). There was strong negative correlation between amount of CH residues and EAL accuracy (r = -0.800 for ${\pm}0.5mm$; r = -0.940 for ${\pm}1.0mm$). Conclusions: The mechanical instrumentation improves the CH removal of irrigation solutions although none of the techniques removed the dressing completely. Residues of CH medication in root canals affected the accuracy of Root-ZX adversely.

• Nutrition Research and Practice
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• v.9 no.5
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• pp.496-502
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• 2015

BACKGROUND/OBJECTIVES: This study was performed to investigate the association between the dietary intake of fish and shellfish, and omega-3 polyunsaturated fatty acids (PUFAs) and cardiovascular disease (CVD) risk factors in the middle-aged Korean female patients with Type 2 diabetes (T2D). SUBJECTS/METHODS: A cross-sectional analysis was performed with 356 female patients (means age: 55.5 years), who were recruited from the Huh's Diabetes Clinic in Seoul, Korea between 2005 and 2011. The dietary intake was assessed by a validated semi-quantitative food frequency questionnaire and analyzed using the Computer Aided Nutritional Analysis program (CAN-Pro) version 4.0 software. RESULTS: In a multiple regression analysis after the adjustment for confounding factors such as age, BMI, duration of diagnosed T2D, alcohol consumption, fiber intake, sodium intake, and total energy intake, fish and shellfish intake of the subjects was negatively associated with triglyceride and pulse wave velocity (PWV). Omega-3 PUFAs intake was negatively associated with triglyceride, systolic blood pressures, diastolic blood pressures, and PWV. The multiple logistic regression analysis with the covariates showed a significant inverse relationship between the omega-3 PUFAs consumption and prevalence of hypertriglyceridemia [OR (95% CI) for greater than the median compared to less than the median: 0.395 (0.207-0.753)]. CONCLUSIONS: These results suggest that the consumption of fish and shellfish, good sources of omega-3 PUFAs, may reduce the risk factors for CVD in the middle-aged female patients with T2D.

• Nutrition Research and Practice
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• v.10 no.1
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• pp.67-73
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• 2016

BACKGROUND/OBJECTIVES: This study was aimed at examining the association between dietary flavanones intake and lipid profiles according to the presence of metabolic syndrome (MetS) in Korean women with type 2 diabetes mellitus (T2DM). SUBJECTS/METHODS: A cross-sectional analysis was performed among 502 female T2DM patients (non-MetS group; n = 129, MetS group; n = 373) who were recruited from the Huh's Diabetes Clinic in Seoul, Korea between 2005 and 2011. The dietary intake was assessed by a validated semi-quantitative food frequency questionnaire (FFQ) and the data was analyzed using the Computer Aided Nutritional Analysis program (CAN-Pro) version 4.0 software. The intake of flavanones was estimated on the basis of the flavonoid database. RESULTS: In the multiple linear regression analysis after adjustment for confounding factors, daily flavanones intake was negatively associated with CVD risk factors such as total cholesterol, LDL-cholesterol, and apoB and apoB/apoA1 ratio only in the MetS group but not in the non-MetS group. Multiple logistic regression analysis revealed that the odds ratio for a higher apoB/apoA1 ratio above the median (${\geq}0.74$) was significantly low in the $4^{th}$ quartile compared to that in the $1^{st}$ quartile of dietary flavanones intake [OR: 0.477, 95% CI: 0.255-0.894, P for trend = 0.0377] in the MetS group. CONCLUSIONS: Dietary flavanones intake was inversely associated with the apoB/apoA1 ratio, suggesting a potential protective effect of flavanones against CVD in T2DM women with MetS.