• Journal of Korean Society of Transportation
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• v.22 no.4 s.75
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• pp.135-146
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• 2004

For improving the effectiveness of travel information, some rational paths are needed to provide them to users driving in real road network. To meet it, k-shortest path algorithms have been used in general. Although the k-shortest path algorithm can provide several alternative paths, it has inherent limit of heavy overlapping among derived paths, which nay lead to incorrect travel information to the users. In case of considering the network consisting of several turn prohibitions popularly adopted in real world network, it makes difficult for the traditional network optimization technique to deal with. Banned and penalized turns are not described appropriately for in the standard node/link method of network definition with intersections represented by nodes only. Such problem could be solved by expansion technique adding extra links and nodes to the network for describing turn penalties, but this method could not apply to large networks as well as dynamic case due to its overwhelming additional works. This paper proposes a link-based shortest path algorithm for the travel information in real road network where exists turn prohibitions. It enables to provide efficient alternative paths under consideration of overlaps among paths. The algorithm builds each path based on the degree of overlapping between each path and stops building new path when the degree of overlapping ratio exceeds its criterion. Because proposed algorithm builds the shortest path based on the link-end cost instead or node cost and constructs path between origin and destination by link connection, the network expansion does not require. Thus it is possible to save the time or network modification and of computer running. Some numerical examples are used for test of the model proposed in the paper.

• Annals of Clinical Neurophysiology
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• v.11 no.2
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• pp.54-58
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• 2009

Background: Obstructive sleep apnea (OSA) is associated with several cardiovascular diseases. However, the mechanisms are not completely understood. The measure of common carotid artery intima-media thickness (IMT) has been extensively used as an early marker of atherosclerosis. The aim of this study was to test the hypothesis that early signs of atherosclerosis are present in patients with OSA and correlate with OSA severity Methods: Eleven male patients with OSA were studied by using full standard overnight polysomnography and high-definition echo-tracking device to measure intima-media thickness and carotid artery diameter. Eight healthy volunteers matched for age and sex were studied by portable respiratory monitoring device. All participants were free of hypertension, diabetes, and were not on any medications. Patients with OSA were naive to treatment. Results: All patients and normal controls were male. There was no significant difference of age between patients and controls ($48.4{\pm}8.85$ and $48.0{\pm}9.77$). Significant differences existed between control subjects and patients with mild to moderate and severe OSA (apnea-hypopnea index, $1.51{\pm}1.15$ and $38.51{\pm}19.13$ respectively) in intima-media thickness ($0.59{\pm}0.064$ and $0.93{\pm}0.16$; P=0.0023), and carotid diameter ($5.79{\pm}0.44$ and $6.47{\pm}0.51$; P=0.0227). Multivariate analyses showed that the apnea-hypopnea index correlated independently with intima-media thickness and carotid diameter (r=0.79, P=0.0008, and r=0.47, P=0.0482). Conclusions: Middle-aged patients with OSA who are free of overt cardiovascular diseases have early signs of atherosclerosis, which further supports the hypothesis that OSA plays an independent role in atherosclerosis progression.

• Journal of The Korean Society of Agricultural Engineers
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• v.62 no.2
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• pp.63-73
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• 2020

Drought is considered as a devastating hazard that causes serious agricultural, ecological and socio-economic impacts worldwide. Fundamentally, the drought can be defined as temporarily different levels of inadequate precipitation, soil moisture, and water supply relative to the long-term average conditions. From no unified definition of droughts, droughts have been divided into different severity level, i.e., moderate drought, severe drought, extreme drought and exceptional drought. The drought severity classification defined the ranges for each indicator for each dryness level. Because the ranges of the various indicators often don't coincide, the final drought category tends to be based on what the majority of the indicators show and on local observations. Evaporative Stress Index (ESI), a satellite-based drought index using the ratio of potential and actual evaporation, is being used as a index of the droughts occurring rapidly in a short period of time from studies showing a more sensitive and fast response to drought compared to Standardized Precipitation Index (SPI), and Palmer Drought Severity Index (PDSI). However, ESI is difficult to provide an objective drought assessment because it does not have clear drought severity classification criteria. In this study, U.S. Drought Monitor (USDM), the standard for drought determination used in the United States, was applied to ESI, and the Percentile method was used to classify drought categories by severity. Regarding the actual 2017 drought event in South Korea, we compare the spatial distribution of drought area and understand the USDM-based ESI by comparing the results of Standardized Groundwater level Index (SGI) and drought impact information. These results demonstrated that the USDM-based ESI could be an effective tool to provide objective drought conditions to inform management decisions for drought policy.

• The Journal of the Korea Contents Association
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• v.17 no.4
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• pp.478-487
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• 2017

In recent years, developed countries have begun to pay attention to female workers through work-family balance in order to solve the problem of low fertility and aging. Korea has been building and running a women leaders database (hereafter, women leaders DB) centered on the female professionals since 2011. In particular, the Incheon women leader DB, which was built by Incheon city in 2009, is a classic example. As of 2015, about 2,735 people are registered in Incheon Women Leaders DB and it is systematically creating the database such as age, education, career years, major, occupation, and certification. However, there are administrative problems such as unspecified definition on professionalism and data trust issues including data entry, and DB personnels are concentrated in specific fields. Also, in the case of certification proving expertise, the utilization problem has been revealed including inclusion of private certification not yet verified. In order to solve these problems, we first need to clarify the concept of women leaders and establish the standard. The second is the improvement of data consistency through DB reorganization, and third is to build a system through continuous and active public relations that is used by both job seekers and recruiters.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.21 no.8
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• pp.370-378
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• 2020

The Construction Operations Building Information Exchange (COBie) collects and documents a large amount of information from different paths in one place during design and construction projects. This documented information is readily available as a means of continuously transferring data to the facility management systems used by building engineers. In this process, the COBie Worksheet, an open standard form, is used to input the information by simplifying the list required by the user. As a result, COBie was developed to improve dramatically how relevant information is obtained and updated to support operations, maintenance, and asset management at the design and construction stages. On the other hand, to use COBie, a great deal of manual work is required for information linkage and quality inspection with heterogeneous data models. These issues become obstacles to COBie-based facility management system development. This study analyzed the COBie information system and defined the framework for simpler operating maintenance information from BIM (Building Information Modeling). Moreover, the rules for facility management information submission, quality inspection, role definition of framework components, and information linkage were derived. COBie DB schema and support data linkages could be generated effectively based on the proposed framework in prototype development.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.18 no.3
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• pp.185-198
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• 2017

Since the year 2000, the growth rate of domestic manufacturing has declined and the sales and employment have decreased. Major developed countries have established a variety of strategies to strengthen their manufacturing competitiveness, and promote manufacturing innovation through the convergence of technology and ICT. The key to manufacturing innovation is to reduce the time and cost for developing new products using modeling and simulation (M&S) technology in the product design stage. M&S industries, which belong to the top sector of the industry value chain, have a huge ripple effect across other industries. On the other hand, the competitiveness of the domestic M&S industry is weak compared to developed countries and even the definition and classification of domestic M&S companies have not been made. In this paper, by analyzing the Korea Standard Industry Classification (KSIC), five fine industry classifications included in M&S service companies were derived. In addition, the 307 M&S service companies were derived in accordance with the selection procedure of 3 steps from the 11,822 related companies. To analyze the capabilities of domestic M&S service companies, the current status of the selected M&S service companies was investigated. Considering the Korean economy's high dependence on the manufacturing industry, strengthening the competitiveness of manufacturing industry is required by enhancing the capacities and building an ecosystem in domestic M&S services for future sustainable economic growth.

• The korean journal of orthodontics
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• v.38 no.6
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• pp.427-436
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• 2008

Objective: The purpose of this study is to compare landmark position between cephalometric radiography and midsagittal plane projected images from 3 dimensional (3D) CT. Methods: Cephalometric radiographs and CT scans were taken from 20 patients for treatment of mandibular prognathism. After selection of land-marks, CT images were projected to the midsagittal plane and magnified to 110% according to the magnifying power of radiographs. These 2 images were superimposed with frontal and occipital bone. Common coordinate system was established on the base of FH plane. The coordinate value of each landmark was compared by paired t test and mean and standard deviation of difference was calculated. Results: The difference was from $-0.14{\pm}0.65$ to $-2.12{\pm}2.89\;mm$ in X axis, from $0.34{\pm}0.78$ to $-2.36{\pm}2.55\;mm$ ($6.79{\pm}3.04\;mm$) in Y axis. There was no significant difference only 9 in X axis, and 7 in Y axis out of 20 landmarks. This might be caused by error from the difference of head positioning, by masking the subtle end structures, identification error from the superimposition and error from the different definition.

• Journal of the Institute of Electronics Engineers of Korea CI
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• v.41 no.6
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• pp.81-89
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• 2004

In this paper, we compare face recognition rate by PCA algorithm using distance change and embedded data being input left side and right side image in stereo images. The proposed method detects face region from RGB color space to YCbCr color space. Also, The extracted face image's scale up/down according to distance change and extracts more robust face region. The proposed method through an experiment could establish standard distance (100cm) in distance about 30∼200cm, and get 99.05% (100cm) as an average recognition result by scale change. The definition of super state is specification region in normalized size (92${\times}$112), and the embedded data extracts the inner factor of defined super state, achieved face recognition through PCA algorithm. The orignal images can receive specification data in limited image's size (92${\times}$112) because embedded data to do learning not that do all learning, in image of 92${\times}$112 size averagely 99.05%, shows face recognition rate of test 1 99.05%, test 2 98.93%, test 3 98.54%, test 4 97.85%. Therefore, the proposed method through an experiment showed that if apply distance change rate could get high recognition rate, and the processing speed improved as well as reduce face information.

• The Journal of Internal Korean Medicine
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• v.33 no.3
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• pp.243-256
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• 2012

Objectives : This clinical study was done to examine metabolic syndrome (MS) and plasma homocysteine (HCY) level in patients with silent lacunar infarction (SLI) and in normal controls. Methods : A total of 154 patients, who were over 20 years of age and visited the stroke prevention check-up center of a university hospital from December 2006 to December 2010, were examined by brain CT or brain MRI, and classified into two groups. We compared the components of MS and HCY levels between patients with SLI (n=74) and normal controls (n=80). Modified ATP III definition was used for diagnosis of MS while Korean standard for waist circumference was used. Results : Prevalence of MS was significantly higher in the SLI group than the normal group. HCY was also significantly higher in the SLI group than the noraml, and the odds ratio (OR) for SLI, comparing high HCY level (${\geq}10{\mu}mol/L$) with low HCY level ($<10{\mu}mol/L$), was 3.64 (95% confidence interval (CI); 1.81-7.29, p<.0001). However, there was no correlation between MS and HCY in the SLI group. Prevalence of diabetes and hypertension (HT) was higher in the SLI group than the normal group, but there was no significant difference in blood lipids level between the SLI and normal groups. Of note, HT itself was enough to be an independent risk factor for SLI (OR; 4.58, 95% CI; 1.91-11.01, p=0.001). Body mass index, waist circumference, waist-hip ratio and visceral fat area were significantly higher in the SLI than normal group, and visceral fat area was enough to be an independent risk factor for SLI (OR; 2.41, 95% CI; 1.04-5.59, p=0.040). Conclusions : SLI is shown to have significant correlation with HCY and prevalence of MS, however there is no relationship between HCY and prevalence of MS in patients with SLI.

• Journal of Preventive Medicine and Public Health
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• v.39 no.6
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• pp.477-484
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• 2006

Objectives : This study was conducted to examine the association between the carotid artery intima-media thickness (IMT), plaque and cardiovascular risk factors according to gender and age. Methods : The data used for this study were obtained from 1,507 subjects (691 men, 816 women), aged 20-74 years, who participated in 'Prevalence study of thyroid diseases' in two counties of Jeollanam-do Province during July and August of 2004. The body mass index (BMI) and waist hip ratio (WHR) were calculated by anthropometry The blood pressure, pulse rate, pulse pressure, total cholesterol, triglyceride, HDL cholesterol and fasting blood sugar level were also measured. Ultrasonography was used to measure the carotid artery IMT and plaque. IMT measurements were performed at 6 sites, including both common carotid arteries, and the bulb and internal carotid arteries. The definition of the 'mean IMT' was mean value obtained from these 6 sites. Results : The ${\pm}$ standard deviation IMT values were $0.65{\pm}0.14\;and\;0.60{\pm}0.13mm$ in men and women (p<0.001), respectively. The data were analyzed according to gender and the 50 year age groups. In a multiple linear regression analysis, age and hypertension were positively associated with the mean IMT in both men and women, aged<50 years. Age, total cholesterol and smoking (current) were positively associated with the mean IMT in men $(\geq50\;years)$. Age was positively associated with the mean IMT in women $(\geq50\;years)$, but the HDL cholesterol level was negatively associated. The prevalence of plaques was 44.2%(196/443) in men and 19.4%(89/459) in women, for those greater than 50 years of age. In a multiple logistic regression analysis, age (OR=1.090, 95%CI=1.053-1.129), HDL cholesterol (OR=0.964, 95%CI=0.944-0.984), total cholesterol (OR=1.009, 95%CI=1.002-1.017)and BMI (OH=0.896, 95%CI=0.818-0.983) were independently associated with plaques in men; whereas, age (OR=1.057, 95%CI=1.012-1.103), HDL cholesterol (OR=0.959, 95%CI=0.932-0.986), pulse pressure (OR=1.029, 95%CI=1.007-1.050) and triglycerides (OR=0.531, 95%CI=0.300-0.941) were independently associated with plaques in women. Conclusions: There were significant gender and aging differences in the association between the IMT, plaque and cardiovascular risk factors. Therefore, for the prevention of atherosclerosis, selective approaches should be considered with regard to gender and age factors.