• Communications for Statistical Applications and Methods
• /
• v.29 no.2
• /
• pp.193-202
• /
• 2022

Semi-supervised learning has gained significant attention in recent applications. In this article, we provide a selective overview of popular semi-supervised methods and then propose a simple but effective algorithm for semi-supervised classification using support vector machines (SVM), one of the most popular binary classifiers in a machine learning community. The idea is simple as follows. First, we apply the dimension reduction to the unlabeled observations and cluster them to assign labels on the reduced space. SVM is then employed to the combined set of labeled and unlabeled observations to construct a classification rule. The use of SVM enables us to extend it to the nonlinear counterpart via kernel trick. Our numerical experiments under various scenarios demonstrate that the proposed method is promising in semi-supervised classification.

• The Journal of the Korea Contents Association
• /
• v.9 no.7
• /
• pp.45-56
• /
• 2009

There are many internet users who collect the public opinions and express their opinions for internet news or blog articles through the replying comment on online community. But, it is hard to search and explore useful messages on web blogs since most of web blog systems show articles and their comments to the form of sequential list. Also, spam and malicious comments have become social problems as the internet users increase. In this paper, we propose a clustering and visualizing system for responding comments on large-scale weblogs, namely 'Daum AGORA,' using similarity analysis. Our system shows the comment clustering result as a simple screen view. Our system also detects spam comments using Needleman-Wunsch algorithm that is a well-known algorithm in bioinformatics.

• Journal of Microbiology and Biotechnology
• /
• v.17 no.11
• /
• pp.1772-1781
• /
• 2007

Activated sludge was sequentially adapted to benzene, toluene, and o-xylene (BTX) to study the effects on the change of microbial community. Sludge adapted to BTX separately degraded each by various rates in the following order; toluene>o-xylene>benzene. Degradation rates were increased after exposure to repeated spikes of substrates. Eleven different kinds of sludge were prepared by the combination of BTX sequential adaptations. Clustering analyses (Jaccard, Dice, Pearson, and cosine product coefficient and dimensional analysis of MDS and PCA for DGGE patterns) revealed that acclimated sludge had different features from nonacclimated sludge and could be grouped together according to their prior treatment. Benzene- and xylene-adapted sludge communities showed similar profiles. The sludge profile was affected from the point of the final adaptation substrate regardless of the adaptation sequence followed. In the sludge adapted to 50 ppm toluene, Nitrosomonas sp. and bacterium were dominant, but these bands were not dominant in benzene and benzene after toluene adaptations. Instead, Flexibacter sp. was dominant in these cultures. Dechloromonas sp. was dominant in the culture adapted to 50 ppm benzene. Thauera sp. was the main band in the sludge adapted to 50 ppm xylene, but became vaguer as the xylene concentration was increased. Rather, Flexibacter sp. dominated in the sludge adapted to 100 ppm xylene, although not in the culture adapted to 250 ppm xylene. Two bacterial species dominated in the sludge adapted to 250 ppm xylene, and they also existed in the sludge adapted to 250 ppm xylene after toluene and benzene.

• Journal of Internet Computing and Services
• /
• v.10 no.2
• /
• pp.153-160
• /
• 2009

One of the major challenges of designing a dissemination protocol for Wireless Sensor Networks(WSNs) is energy efficiency. Recently, this issue has received much attention from the research community, and SPMS, which outperforms the well-known protocol SPIN, specially is a representative protocol. In addition, one of many characters of SPMS is the use of the shortest path to minimize the energy consumption. However, since it repeatedly uses the same path as the shortest path, the maximizing of the network lifetime is impossible, though it reduces the energy consumption. In this paper, we propose a dissemination protocol using probability-based clustering which guarantees energy-efficient data transmission and maximizes network lifetime. The proposed protocol solves the network lifetime problem by a novel probability function, which is related to the residual energy and the transmission radius between nodes. The simulation results show that it guarantees energy-efficient transmission and moreover increases the network lifetime by approximately 78% than that of SPMS.

• Asian Pacific Journal of Cancer Prevention
• /
• v.15 no.3
• /
• pp.1149-1154
• /
• 2014

Background: In Malaysia, data from the Malaysian Health Ministry showed colorectal cancer (CRC) to be the second most common type of cancer in 2007-2009, after breast cancer. The same was apparent after looking at males and females cases separately. In the present study, the Geographic Information System (GIS) was employed to describe the distribution of CRC cases in Kuala Lumpur (KL), Malaysia, according to socio-demographic factors (age, gender, ethnicity and district). Materials and Methods: This retrospective review concerned data for patients diagnosed with colorectal cancer in the years 1995 to 2011 collected from the Wilayah Persekutuan Health Office, taken from the cancer notification form (NCR-2), and patient medical records from the Surgical Department, Universiti Kebangsaan Malaysia Medical Centre (UKMMC). A total of 146 cases were analyzed. All the data collected were analysed using ArcGIS version 10.0 and SPSS version 19.0. Results: Patients aged 60 to 69 years accounted for the highest proportion of cases (34.2%) and males slightly predominated 76 (52.1%), Chinese had the highest number of registered cases at 108 (74.0%) and staging revealed most cases in the 3rd and 4th stages. Kernel density analysis showed more cases are concentrated up in the northern area of Petaling and Kuala Lumpur subdistricts. Spatial global pattern analysis by average nearest neighbour resulted in nearest neighbour ratio of 0.75, with Z-score of -5.59, p value of <0.01 and the z-score of -5.59. Spatial autocorrelation (Moran's I) showed clustering significant with p<0.01, Z score 3.14 and Moran's Index of 0.007. When mapping clusters with hotspot analysis (Getis-Ord Gi), hot and cold spots were identified. Hot spot areas fell on the northeast side of KL. Conclusions: This study demonstrated significant spatial patterns of cancer incidence in KL. Knowledge about these spatial patterns can provide useful information to policymakers in the planning of screening of CRC in the targeted population and improvement of healthcare facilities to provide better treatment for CRC patients.

• The Korean Journal of Ecology
• /
• v.28 no.1
• /
• pp.15-23
• /
• 2005

The black locust (Robinia pseudoacacia L.) forests were studied by a phytosociological approach. Particular attention was given to characterize the vegetation classification, distribution pattern, and ecological flora of the syntaxa classified. A total of 38 releves were analyzed by using Correlation coefficient, UPGMA as the clustering method, and Principal Coordinates Analysis for ordination. Ecological flora analyzed by plant character sets such as scrambler, annual and biennial plants, forest elements, and actual urbanization index. The analyzed data are based on site-releve matrix with relative net contribution degree (r-NCD) of species. A total of 77 families, 193 genera and 323 species of vascular plants are recorded. Camellino-Robinietum pseudoacaciae ass. nov. and Phragmites-Robinia pseudoacacia community were described. Main cluster and ordination could be separated: 1) urban type, 2) rural type, 3) riparian type, and 4) combined type. It is defined that the Robinietum is a representative unit on the black locust afforestation, Phragmites-Robinia community on the lentic zone in the river ecosystem, and Cameliino-Robinietum ailanthetosum altissimae as an urban forest type. The Robinietum was considered as a perpetual community.

• Asian Pacific Journal of Cancer Prevention
• /
• v.15 no.18
• /
• pp.7897-7907
• /
• 2014

Background: There is paucity of studies defining the prevalence of non-communicable disease (NCD) risk factors in Saudi Arabia despite the surging epidemic of obesity, change in dietary habits and sedentary lifestyle. Objectives: This cross-sectional study aimed to assess the prevalence of NCDs risk factors among employees at King Faisal University in Al Hassa, Saudi Arabia and to determine the possible correlates for clustering of NCDs risk factors among them. Materials and Methods: All employees were invited to participate; the World Health Organization STEPwise approach was used for data collection which consisted of a personal interview to collect socio-demographic characteristics, NCD history, tobacco use, vegetables and fruit consumption, and physical activity (PA), followed by anthropometric measurements namely weight, height and waist circumference and blood pressure measurements, subjects were finally subjected to biochemical tests with determination of fasting plasma glucose, serum triglycerides, cholesterol and high density lipoproteins. Results: Of the surveyed employees (n=691), daily current smokers accounted for 22.7%. 94.9%, 95.1% and 86% consumed < 5 servings per day of vegetables, fruits and both fruits and vegetables respectively, 73% were physically inactive, 64% were overweight or obese, 22.1% had hypertension, and 21.5% were diabetics. Elevated cholesterol levels were found in 36.6%, low high density lipoproteins in 36.8%, and elevated triglycerides in 36.1%. Only 3% had no NCD risk factors, and 57.6% had ${\geq}3$ factors. Multivariate logistic regression showed that gender (being male, adjusted odds ratio 'aOR'=1.51), aged ${\geq}50$ years (aOR=3.06), < college education (aOR=1.75), current smokers (aOR=2.37), being obese (aOR=6.96) and having a low PA level (aOR=4.59) were the significant positive predictors for clustering of NCD risk factors. Conclusions: Over fifty percent of the studied university's employees had multiple (${\geq}3$) NCD risk factors. Screening and health promotion initiatives should be launched at least targeting the modifiable factors to avert the excessive risk for cardiovascular disease, diabetes mellitus and several types of cancers.

• KSCE Journal of Civil and Environmental Engineering Research
• /
• v.35 no.1
• /
• pp.203-215
• /
• 2015

The study aims to identify the degree and types of spatial recessions in Si/Gun and Eup/Myun units within Chungcheong region in South Korea to contribute to the efforts being made to diagnose the rural recession and the potentials. To this end, we analyzed 27 Sis and Guns to identify the degree of recession and potentials of rural areas in Chungcheong region. We also carried out the diagnosis and K-Means Clustering on 274 Eups and Myuns, smaller administrative units, to figure out the types and characteristics of the rural recessions. In case of the analysis targeting the Sis and Guns, a relatively high degree of rural recession was found in Cheongyang, Seocheon and Taean for Chungcheongnam-do, and in Danyang and Goisan, as well as in Boeun, Okcheon and Youngdong - which are collectively called as 'Southern 3 Areas in Chungcheongbuk-do' as they are conventionally known by their high degree of rural recession. According to the results of the clustering analysis carried out on the 166 Eups and Myuns, there were five outstanding clusters. They were; areas with housing deterioration (29), areas with poor economic foundation (16), areas with poor accessibility to central areas (42), areas with poor residential environment (51) and areas with aged population (28). The findings and results of the present study are likely to serve as a basis for the design and enforcement of forthcoming rural area activation policies. Also, it would be highly recommended that a more comprehensive diagnosis is taken from a community-level perspective and policy suggestions and strategies tailored for rural communities are further discussed.

• Journal of Internet Computing and Services
• /
• v.16 no.3
• /
• pp.59-69
• /
• 2015

Many users visit websites every day to perform information retrieval, shopping, and community activities. On the other hand, there is intense competition among sites which attempt to profit from the Internet users. Thus, the owners or marketing officers of each site try to design a variety of marketing strategies including cooperation with other sites. Through such cooperation, a site can share customers' information, mileage points, and hyperlinks with other sites. To create effective cooperation, it is crucial to choose an appropriate partner site that may have many potential customers. Unfortunately, it is exceedingly difficult to identify such an appropriate partner among the vast number of sites. In this paper, therefore, we devise a new methodology for recommending appropriate partner sites to each site. For this purpose, we perform site clustering from the perspective of visitors' similarities, and then identify a group of sites that has a number of common customers. We then analyze the potential for the practical use of the proposed methodology through its application to approximately 140 million actual site browsing histories.

• Architectural research
• /
• v.9 no.1
• /
• pp.9-18
• /
• 2007

The objective of this research study was twofold; 1) to explore and identify health supportive design factors in Swedish elderly care homes and 2) to understand their usefulness and suggest implication in Korean elderly care settings. A descriptive and explorative method was applied using a combination of field studies and semi-structured interviews. Three study trips were carried out during Sept. $14^{th}$ and Oct. $12^{th}$ 2005; two facilities situated in Stockholm suburbs and one in the south of Sweden. According to this research, the valuable factors to support health and well-being for the elderly are as follows; 1) Community integration: These elderly care homes are generally places close to a residential area center or a city center. Services are often shared between residents and community members at large, consequently there is a flow of "visitors" of all ages connecting with the facility on a daily basis. 2) Homelike environment: A noteworthy aspect of Swedish elderly care homes is keeping the facility appearance as homelike as possible. The associations with home may be explored through the appearance and configuration of both the exterior and interior of the building. These homes seemed to be designed with a conscious aim to create a homelike setting. 3) Small scale approach: Clustering of resident rooms is one method through which the small scale approach can be achieved in larger facilities. With unit clusters, the facility can foster opportunities for social interactions among resident. 4) Accessibility to garden and nature: The courtyard is a well developed concept in planning elderly care homes in Sweden. They are generally safe and easily accessible to the residents. Studying Swedish models may provide practical knowledge of how the physical setting may improve resident's health in Korean elderly care homes.