• KSCE Journal of Civil and Environmental Engineering Research
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• v.44 no.1
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• pp.63-73
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• 2024

Autonomous vehicles at Levels 3 to 5, currently under global research and development, seek to replace the driver's perception, judgment, and control processes with various sensors integrated into the vehicle. This integration enables artificial intelligence to autonomously perform the majority of driving tasks. However, autonomous vehicles currently obtain temporary driving permits, allowing them to operate on roads if they meet minimum criteria for autonomous judgment abilities set by individual countries. When autonomous vehicles become more widespread in the future, it is anticipated that buyers may not have high confidence in the ability of these vehicles to avoid hazardous situations due to the limitations of temporary driving permits. In this study, we propose a method for grading the judgment abilities of autonomous vehicles based on a driving simulator experiment comparing and evaluating drivers' abilities to avoid hazardous situations. The goal is to derive evaluation criteria that allow for grading based on specific scenarios and to propose a framework for grading autonomous vehicles. Thirty adults (25 males and 5 females) participated in the driving simulator experiment. The analysis of the experimental results involved K-means cluster analysis and independent sample t-tests, confirming the possibility of classifying the judgment abilities of autonomous vehicles and the statistical significance of such classifications. Enhancing confidence in the risk-avoidance capabilities of autonomous vehicles in future hazardous situations could be a significant contribution of this research.

• Journal of Korean Society of Transportation
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• v.26 no.3
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• pp.53-66
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• 2008

This research is to the establishment of a conceptual framework that supports road characteristic classification from a new point of view in order to complement of the existing road functional classification and examine of traffic pattern. The road characteristic classification(RCC) is expected to use important performance criteria that produced a policy guidelines for transportation planning and operational management. For this study, the traffic data used the permanent traffic counters(PTCs) located within the national highway between 2002 and 2006. The research has described for a systematic review and assessment of how exploratory factor analysis should be applied from 12 explanatory variables. The optimal number of components and clusters are determined by interpretation of the factor analysis results. As a result, the scenario including all 12 explanatory variables is better than other scenarios. The four components is produced the optimal number of factors. This research made contributions to the understanding of the exploratory factor analysis for the road characteristic classification, further applying the objective input data for various analysis method, such as cluster analysis, regression analysis and discriminant analysis.

• Korean Journal of Materials Research
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• v.12 no.11
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• pp.860-864
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• 2002

$Li^{+}$ extraction reactions with ion-exchange type lithium manganese oxide in an aqueous phase were examined using chemical and x-ray diffraction (XRD) analysis. In the process of extraction reaction, the lithium manganese oxide showed a topotactic extraction of $Li^{+ }$ in the aqueous phase mainly through an ion-exchange mechanism, and the $Li^{+}$ extracted samples indicated a high selectivity and a large capacity for $Li^{+}$ . The electronic structures and chemical bonding properties were also studied using a discrete variational (DV)-X$\alpha$ molecular orbital method with cluster model of (Li$Mn_{12}$ $O_{40}$ )$^{27-}$ for tetrahedral sites and ($Li_{7}$ Mn $O_{38}$ )$^{3}$ for octahedral site in $Li_{1.33}$ $Mn_{1.67}$ / $O_{4}$ respectively. Li in the manganese oxides is highly ionized in both sites, but the net charge of Li was greater for tetrahedral sites than octahedral. These calculations suggest that the tetrahedral sites have higher $Li^{+}$ $H^{+}$ exchangeability than the octahedral sites, and are preferable for the selective adsorption for L $i^{+}$ ions.s.

• Journal of the Korean Society of Costume
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• v.62 no.5
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• pp.31-43
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• 2012

The purposes of this study were to investigate the differences of post-purchase satisfaction, brand loyalty, and repurchase intention of SPA clothing brand according to lifestyles, and to disclose how lifestyles, post-purchase satisfaction, and brand loyalty influence the repurchase intention. The research method was a survey method using questionnaires. The subjects were 304 female college students residing in Seoul metropolitan area. The lifestyles were classified into six factors including pursuit of challenges, proactive interpersonal relationship, interest in sports, self-centeredness, interest in IT, and achievement orientation. Three female groups were derived by cluster analysis of the 6 lifestyle factors: active-activity type, passive-activity type, and achievement-pursuit type. Brand loyalty was classified into two factors including continuing loyalty and convenient loyalty. First, the active-activity group showed higher convenient loyalty than the other groups. The achievement-pursuit group showed higher post-purchase satisfaction than the other groups in appearance of clothing, while the passive-activity group showed lower satisfaction in every factor, in particular, its price satisfaction was very low. Second, senior students showed higher continuing loyalty than freshmen, sophomores, and juniors. Students with more clothing expenses showed higher continuing loyalty as well as convenient loyalty than those with less clothing expenses. Their price satisfaction with SPA clothing brand as well as repurchase intention was higher. Third, repurchase intention was influenced by brand loyalty the most, and the next in the order by satisfaction level with brand, satisfaction with price, satisfaction level with appearance, and proactive interpersonal relationship. The brand loyalty was influenced by satisfaction level with price the most, and the next by satisfaction level with appearance.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.37 no.3
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• pp.259-266
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• 2013

An automated cell tracking system is used to automatically analyze and track the changes in cell behavior in time-lapse cell images acquired using a microscope with a cell culture. Clustering is the partial overlapping of neighboring cells in the process of cell change. Separating clusters into individual cells is very important for cell tracking. In this study, we proposed an algorithm for separating clusters by using ellipse fitting based on a direct least square method. We extracted the contours of clusters, divided them into line segments, and then produced their fitted ellipses using a direct least square method for each line segment. All of the fitted ellipses could be used to separate their corresponding clusters. In experiments, our algorithm separated clusters with average precisions of 91% for two overlapping cells, 84% for three overlapping cells, and about 73% for four overlapping cells.

• Journal of Korean Society of Forest Science
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• v.90 no.4
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• pp.573-581
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• 2001

The purposes of this study are to estimate mean willingness to pay (WTP) for preventing forest fires by contingent valuation method (CVM), and to calibrate the variables affecting WTP. The forest fire prevention fund was utilized as a payment vehicle to elicit respondents' willingness to pay (WTP). A total of 500 adults who reside in Seoul Metropolitan area were selected by two-stage cluster sampling and conducted the face-to-face interview. The scenario was designed to meet the requirements for double-bounded dichotomous choice CVM. More than half of the respondents (64.6%) have a willing to pay for the fund. The mean WTP was \4,532. Therefore a total WTP for the population was \34,165,758,000. The calibration of Weibull proportional hazard model showed that education level, environmental conservation intention and negative consciousness about the effect of forest fire were independent variables strongly influencing the WTP.

• Journal of Forest and Environmental Science
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• v.25 no.2
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• pp.93-100
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• 2009

In Malaysia, Labisia pumila Benth & Hook f, popularly known as 'Kacip Fatimah' has been used traditionally to treat various elements of the woman's health in Malay community. The objective of this study was to develop randomly amplified polymorphic DNA (RAPD) based DNA markers for the identification of L. pumila and to distinguish its three varieties from each other. Total DNA from nine accessions of L. pumila was extracted by CTAB method and polymerase chain reactions (PCR) were carried out to amplify the segments of DNA using different primers to develop DNA barcode using RAPD technique. To find out variety-specific DNA marker/s, twenty different 10-mer primer sequences with annealing temperature from 36-$40^{\circ}C$ were evaluated in triplicate. Out of 20 random primers, two primers (OPA-1 and OPA-2/A10) were selected which produced reliable RAPD band patterns. To have DNA based handle, two RAPD amplification products were cloned and sequenced to determine the identity of the DNA. RAPD analysis using two random primers generated 72 discrete bands ranging in size 200 bp-3,000 bp. Fifty nine of these were polymorphic loci (82%) and thirteen were non-polymorphic loci (18%). A total of 32 bands polymorphic loci (72%) were amplified with primer OPA-1 and analyzed by cluster analysis and UPGMA (Unweighted Pair Group Method with Arithmetic) to present a dendogram depicting the degree of genetic relationship among nine accessions of L. pumila. Our results shows the reasonable genetic diversity among the L. pumila varieties and within varieties; and two RAPD marker sequences obtained could be used to identify L. pumila at species level.

• Asian Pacific Journal of Cancer Prevention
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• v.16 no.16
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• pp.6935-6939
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• 2015

Background: Currently, a comprehensive program for screening and early detection of cervical cancer does not exist in Iran. This study aimed to determine the prevalence of abnormal Papanicolaou (Pap) smears and some related factors among women living in Zanjan, Iran. Materials and Methods: This cross-sectional study was conducted in 2012 in Zanjan on 4274 married women aged 20-65 years. The study participants were selected through two-stage cluster sampling. After obtaining written consent, demographic and fertility questionnaires were completed. Samples from cervix were obtained through a standard method using the Rover Cervex- Brush. Evaluation and interpretation of the samples were reported using the Bethesda 2001 method. Data were statistically analyzed using chi-square and logistic regression models. Results: Most inflammatory changes in the samples were mild (37.4%). Abnormal atypical changes in the epithelial cells were found in 4.04%. The highest percentage of abnormal changes in the epithelial cells was atypical squamous cells of undetermined significance (ASCUS) (1.9%). Abnormal results of Pap smear was significantly and independently associated with age, papillomavirus infection, and lack of awareness about Pap smear tests. Conclusions: Given the high prevalence of inflammatory and precancerous changes in this study, compared to other studies in Iran and other Muslim countries, and the effect of demographic variables and individual factors on abnormal results, increasing the awareness of women and their families regarding the risk factors for cervical cancer, preventive measures such as screening, and timely treatment seem necessary.

• Journal of KIISE:Computer Systems and Theory
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• v.29 no.7
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• pp.384-393
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• 2002

A Parallel file system is normally used to support excessive file requests from parallel applications in a cluster system, whereas prefetching is useful for improving the file system performance. This paper proposes a new prefetching method, Fips(dynamic File Prefetching Scheme based on file access patterms), that is particularly suitable for parallel scientific applications and multimedia web services in a parallel file system. The proposed prefetching method introduces a dynamic prefetching scheme to predict data blocks precisely in run-time although the file access patterns are irregular. In addition, it includes an algorithm to determine whether and when the prefetching is performed using the current available I/O bandwidth. Experimental results confirmed that the use of the proposed prefetching policy in a parallel file system produced a higher file system performance.

• Journal of Preventive Medicine and Public Health
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• v.38 no.3
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• pp.351-358
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• 2005

Objectives : Dementia has rapidly increased with the prolongation of life expectancy and aging in Korea. This study was conducted to estimate the prevalence of, and find related factors for, dementia in an urban elderly population, using a newly developed screening method. Methods : Seven hundred and six people, aged over 65 years-old, in Dong district of Gwangju, Korea, were recruited using stratified cluster sampling, and completed Korean version of Geriatric Mental State Schedule B3 (GMS B3-K), the Korean version of the Community Screening Interview for Dementia (CSID-K) and modified 10 word list-learning from the Consortium to Establish a Registry of Alzheimer's Disease (CERAD). Dementia was diagnosed by an algorithm derived from all three of these measures. Results : The crude and age adjusted prevalence rates of dementia were 13.0 and 11.5%, respectively. Age, education, marital status and a history of cerebrovascular disease were identified as factors related with dementia. Conclusions : The new instrument, using the GMS B3-K, CSID-K and modified 10 word list-learning from the CERAD, was considered effective as a community screening and diagnostic tool for dementia. The results of this study can also be used to develop a community-based prevention and management system for dementia in the future.