• The KIPS Transactions:PartB
• /
• v.17B no.5
• /
• pp.399-404
• /
• 2010

In this paper, we propose a method for precision improvement based on core clusters and term proximity. The method is composed by three steps. The initial retrieval documents are clustered based on query term combination, which occurred in the document. Core clusters are selected by using proximity between query terms. Then, the documents in core clusters are reranked based on context information of query. On TREC AP test collection, experimental results in precision at the top documents(P@100) show that the proposed method improved 11.2% over the language model.

• Journal of Korea Water Resources Association
• /
• v.57 no.2
• /
• pp.87-97
• /
• 2024

This study analyzed the water shortage hotspot areas in South Korea using spatial clustering analysis for water shortage estimates in 2030 of the Master Plans for National Water Management. To identify the water shortage cluster areas, we used water shortage data from the past maximum drought (about 50-year return period) and performed spatial clustering analysis using Local Moran's I and Getis-Ord Gi*. The areas subject to spatial clusters of water shortage were selected using the cluster map, and the spatial characteristics of water shortage areas were verified based on the p-value and the Moran scatter plot. The results indicated that one cluster (lower Imjin River (#1023) and neighbor) in the Han River basin and two clusters (Daejeongcheon (#2403) and neighbor, Gahwacheon (#2501) and neighbor) in the Nakdong River basin were found to be the hotspot for water shortage, whereas one cluster (lower Namhan River (#1007) and neighbor) in the Han River Basin and one cluster (Byeongseongcheon (#2006) and neighbor) in the Nakdong River basin were found to be the HL area, which means the specific area have high water shortage and neighbor have low water shortage. When analyzing spatial clustering by standard watershed unit, the entire spatial clustering area satisfied 100% of the statistical criteria leading to statistically significant results. The overall results indicated that spatial clustering analysis performed using standard watersheds can resolve the variable spatial unit problem to some extent, which results in the relatively increased accuracy of spatial analysis.

• Journal of Information Processing Systems
• /
• v.8 no.2
• /
• pp.359-374
• /
• 2012

In this paper, we propose a new machine vision algorithm for automatic defect detection on patterned textures with the help of texture-periodicity and the Jensen-Shannon Divergence, which is a symmetrized and smoothed version of the Kullback-Leibler Divergence. Input defective images are split into several blocks of the same size as the size of the periodic unit of the image. Based on histograms of the periodic blocks, Jensen-Shannon Divergence measures are calculated for each periodic block with respect to itself and all other periodic blocks and a dissimilarity matrix is obtained. This dissimilarity matrix is utilized to get a matrix of true-metrics, which is later subjected to Ward's hierarchical clustering to automatically identify defective and defect-free blocks. Results from experiments on real fabric images belonging to 3 major wallpaper groups, namely, pmm, p2, and p4m with defects, show that the proposed method is robust in finding fabric defects with a very high success rates without any human intervention.

• Health Policy and Management
• /
• v.30 no.2
• /
• pp.199-210
• /
• 2020

Background: Based on the importance of ceasing smoking programs to control the regional disparity of smoking behavior in Korea, this study aims to reveal the variation of smoke rate and determinants of it for 229 provinces. An evaluation of the relative efficiency of the cease smoking program under the consideration of regional characteristics was followed. Methods: The main sources of data are the Korean Statistical Information Service and a national survey on the expenditure of public health centers. Multivariate regression is performed to figure the determinants of regional variation of smoking rate. Based on the result of the regression model, clustering analysis was conducted to group 229 regions by their characteristics. Three clusters were generated. Using data envelopment analysis (DEA), relative efficiency scores are calculated. Results from the pooled model which put 229 provinces in one model to score relative efficiency were compared with the cluster-separated model of each cluster. Results: First, the maximum variation of the smoking rate was 16.9%p. Second, sex ration, the proportion of the elder, and high risk drinking alcohol behavior have a significant role in the regional variation of smoking. Third, the population and proportion of the elder are the main variables for clustering. Fourth, dissimilarity on the results of relative efficiency was found between the pooled model and cluster-separated model, especially for cluster 2. Conclusion: This study figured regional variation of smoking rate and its determinants on the regional level. Unconformity of the DEA results between different models implies the issues on regional features when the regional evaluation performed especially on the programs of public health centers.

• Korean journal of food and cookery science
• /
• v.23 no.3 s.99
• /
• pp.327-336
• /
• 2007

Life-style factors often include social relationships as well as consumption, entertainment and dress patterns. They also typically reflect an individual's attitudes, values and worldview. Life-style types have become and an important factor for segmenting customer markets ever since significant relationships between life-style and customers' behavior was proven. This study examined the relationships between the life-styles of young customers' and the important attributes of foodservice encounters. Factors analysis with VARIMAX and K-means cluster analysis were conducted to group the subjects by life-style. According to the factors analysis, four underlying dimensions were identified and labeled: (1) 'actively fashioned', (2) 'luxury picky', (3) 'healthy toward', and (4) 'utilitarian leisure'. Based on the factor scores derived from the factors analysis, the K-means cluster analysis classified three groups as statistically significant using ANOVA(p<0.05). The overall mean score for the 3rd cluster 'trendy-active picky' was higher than the other two clusters, and represented very picky attitudes about foodservice attributes. The 3rd cluster also seemed to apply higher standards to all of the foodservice attributes. By order of importance, the most important attributes of the 2nd cluster 'pursue-utilitarian leisure' were food serving time, automation systems, server's hygienes, employee kindness, time in line, and menu variety. In spite of low concerns for the life-style attributes, the first cluster 'passively indifferent' recognized menu variety, food sanitation, food serving time, server's hygiene, menu price, air circulation, and room temperature as important. These results suggest that young diners in Korea could be classified by their diverse life-styles that are represented as trendy, utilitarian, and indifferent and will hopefully contribute to the foodservice industry's ability to segment customer characteristics by different life-styles in Korea.

• Journal of Life Science
• /
• v.11 no.2
• /
• pp.74-80
• /
• 2001

The nucleotide sequences of the internal transcribed spacer regions (ITS1 and ITS2) of ribosomal DNA (rDNA), and the 5.85 rRNA gene, have been determined for 13 strains of dinoflagellates in order to analyze the phylo-genetic relationship. The DNA sequences contained considerable variation in the ITS regions, but little in the 5.85 rDNA. In addition, the ITS1 was more variable than the ITS2 in all species examined. The nucleotide length of this region varied from 519 bp to 596 bp depending on the taxa. The investigated taxa were divided into three large groups based on the ITS length, i. e., a group with short ITS region (A. fraterculus and Alexandrium sp.), a with ITS region group (P. micans, P. minimum and P. triestinum) and a with ITS region group (G. impudicum, C. polykrikoides, G. sanguineum, G. catenatum and H. triquetra). The relationship between nucleotide length of ITS1 and that of ITS2 was negative, whereas G+C content and nucleotide length showed positive correlation. In phylogenetic analyses producing NJ trees, the topology was similar cluster and clearly divided the taxa into three groups based on 5.8S rDNA that were similar to those based on morphological characteristics. In particular, G. impudicum was more closely related to G. catenatum than to C. polykrikoides using phylogenetic analysis. From this study, we chew that the length of ITS region contributes to discriminate Korean harmful algal species and ITS analysis is a useful method for resolving the systematic relationships of dinoflagellates.

• Journal of Korean Academy of Fundamentals of Nursing
• /
• v.4 no.2
• /
• pp.283-300
• /
• 1997

This study was undertaken to grasp health-promoting behavior of the elderly and to identify variables related to them in order to facilitate nursing intervention for health promotion of this population. The subjects for this study were 291 old persons obtained by cluster sampling from twenty general social welfare centers located in Tague. Data were collected by self-reported questionnaires from August 13 to September 13, 1996. Questionnaires were developed based on Sherer and others' Self-Efficacy scale, Rosenberg's Self-Esteem scale, Wallston and other's Multidimensional Health Locus of Control scale, Northern illinois University's Helath Self Rating Scale, Walker and others' Health Promotion Lifestyles Profile. Analysis of the data was done by use of descriptive statistics, stepwise multiple regression, Pearson Correlation Coefficient, MANOVA, t-test, and ANOVA. The results were summarized as follows : 1. For the practice of health-promoting behavior, the mean score was 2.89 and range was 3.59 to 2.09. The factor of the highest mean score was regular diet(M=3.42) and factor of the lowest mean score as stress management(M=2.27). 2. The combination of self-efficacy, internal health locus of control, family number, and average monthly pocket money explained 30.0% of the variance of health-promoting behavior. 3. With regard to the relationship between health-promoting behavior and cognitive perceptual factor, self-efficacy correlated positively with health-promoting behavior(r=.4951, P=.0001), self-esteem correlated positively(r=.3263, P=.0001), internal health locus of control correlated positively(r=.3244, P=.0001), perceived health status correlated positively(r=.1355, P=.0274). 4. According to age(F=2.50, P=.0431), sex(t=2.14, P=.0332), marital status(F=7.85, P=.0005), education(F=5.44, P=.0003), family number(F=11.18, P=.0001), people living together(F=7.21, P=.0009), previous occupation(F=5.83, P=.0001), average monthly pocket money(F=7.27, P=.0001), there were differences of health-promoting behavior. The above findings show that health-promoting behavior are related to demographic characteristics, four cognitive perceptual factors(self-efficacy, self-esteem, internal health locus of control, perceived health status). On the basis of the above findings the following recommendations are made ; 1. Nursing interventions enhancing exercise or activity, accountability for health, stress management of the elderly must be provided. 2. Nursing strategies enhancing self-efficacy which is most significant effect on health-promoting behavior must be developed.

• The Journal of Korean Medicine
• /
• v.24 no.1
• /
• pp.122-132
• /
• 2003

Objectives: To effectively improve the treatment of obesity through oriental medicine and to prepare basic material for proper classification of different types of obesity. Methods: After deciding on four types of obesity based on 'DongYiBaoJian', a questionnaire consisting of 38 items was constructed to decide to which type an individual belonged. 212 women were asked to the complete the questionnaire. To verify that the cluster of four types of obesity was acceptable, a cluster analysis and a factor analysis were conducted as well as an evaluation on the distinction of each type. Also, a canonical discriminant analysis was done to categorize the individuals into one of four types of obesity. Results: 1. Developed a reliable questionnaire consisting of 38 items for the purpose of classifying four types of obesity. 2. Obesity types were divided into four groups. Type I was designated as GanChengPi (肝乘脾類型), Type II as PiWeiJuWang(脾胃俱旺類型), Type III as PiWeiJuXu (脾胃俱虛類型), and Type IV as Tan TanYin(痰飮類型). These types were verified and classified through the use of a cluster analysis as well as a factor analysis (p<0.05). 3. By the use of a questionnaire, four types of obesity were correctly classified with a hit ratio of 87.3%, 40.64% higher than the maximum chance criteria (Cmax) in unselected grouped. The hit ratios for obesity types I, II, III and IV were 93.3%, 93.3%, 78.6% and 50%(p<0.05). Conclusion: Further clinical research is necessary into the four types of obesity explored. By analyzing various test results, characteristics these types should be further explored.

• ALGAE
• /
• v.23 no.4
• /
• pp.277-288
• /
• 2008

The relationship between nutrients and phytoplankton dynamics was investigated daily from 12 April to 22 July 2003 in Sagami Bay, Japan. According to multidimensional scaling (MDS) and cluster analysis, phytoplankton community was divided into four distinct groups. The first group was consisted of centric diatom species, such as Guinardia spp., Detonula spp., Letocylindrus danicus, Skeletonema costatum, Eucampia zodiacus and Chaetoceros spp.. The second and third clusters comprised mainly diatoms and dinoflagellates, respectively. The other cluster was restricted to the samples collected during the last sampling period when the rainfall and river discharge was frequently recorded. Canonical correspondence analysis (CCA) was applied to analyze four groups respectively, which focused on the effects of nutrients concentration and ratio on phytoplankton variations. Based on CCA analysis, most species of centric diatom were negatively correlated with DSi concentrations and Si/N ratio. Nutrients were strongly limited phytoplankton growth during the summer when the rainfall was not observed, whereas river discharge by rainfall and counterclockwise coastal currents (although the surface circulation pattern is often altered by Kuroshio Current, the counterclockwise coastal currents are generally dominant) has brought phytoplankton population accumulation and triggered the micoalgae growth in western part of the bay. Phosphorous (P) was strongly limited after significantly increases in the phytoplankton abundances. However, silicate (Si) was not a major limiting factor for phytoplankton production, since Si/DIN and Si/P ratio did not create any potential stoichiometric limitation. This indicates that high Si availability contributes favorably to the maintenance of diatom ecosystems in Sagami Bay.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
• /
• v.46 no.6
• /
• pp.385-392
• /
• 2020

Objectives: This study evaluates soft tissue changes of the upper lip and nose after maxillary setback with orthognathic surgery such as Le Fort I or anterior segmental osteotomy. Materials and Methods: All 50 patients with bimaxillary protrusion and skeletal Class II malocclusion underwent Le Fort I or anterior segmental osteotomy with backward movement. Soft and hard tissue changes were analyzed using cephalograms collected preoperatively and 6 months postoperatively. Results: Cluster analysis on the ratios shows that 2 lines intersected at 4 mm point. Based on this point, we divided the subjects into 2 groups: Group A (less than 4 mm, 27 subjects) and Group B (more than 4 mm, 23 subjects). Also, each group was divided according to changes of upper incisor angle (≥4°=A1, B1 or <4°=A2, B2). The correlation between A and B groups for A'/ANS and Ls/Is (P<0.001) was significant; A'/A (P=0.002), PRN/A (P=0.043), PRN/ANS (P=0.032), and St/Is (P=0.010). Variation of nasolabial angle between the two groups was not significant. There was no significant correlation of vertical movement and angle variation. Conclusion: The ratio of soft tissue to hard tissue movement depends on the amount of posterior movement in the maxilla, showing approximately two times higher rates in most of the midface when posterior movement was greater than 4 mm. The soft tissue changes caused by posterior movement of the maxilla were little affected by angular changes of upper incisors. Interestingly, nasolabial angle showed a different tendency between A and B groups and was more affected by incisal angular changes when horizontal posterior movement was less than 4 mm.