• Imaging Science in Dentistry
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• v.36 no.2
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• pp.95-101
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• 2006

Purpose : Bony strength is dependent on bone mass and bony structure. So this study was designed to investigate the relationship between the bone mass and bony trabecular characteristics. Subjects and Methods : Study subjects were 51 females (average age 68.6 years) and 20 males (average age 66.4 years). Bone mineral density (BMD, $grams/cm^2$) of proximal femur was measured by a dual energy X-ray absorptiometry (DEXA). Regions of interest (ROIs) were selected from the digitized radiographs of proximal femur. A customized computer program processed morphologic operations (MO) of ROIs. 44 skeletal variables of MO were calculated from ROIs on the Ward's triangle and greater trochanter of femur. WHO BMD classes were predicted by MO variables of the same ROI. Classification and Regression Tree analysis was used for calculating weighted kappa values, sensitivity and specificity of MO. Results : The discriminating factors of morphologic operation were branch point, branch point [per cm sq]. Age also played important role in distinguishing osteoporotic classes. The sensitivity of MO at Ward's triangle and Greater Trochanter was 91.8%, 65.6%, respectively. The specificity of MO was 100% at Ward's triangle and Greater Trochanter. Conclusion : Bony trabecular characteristics obtained using radiological bone morphometric analysis seem to be related to bone mass.

• Journal of Aquaculture
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• v.21 no.3
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• pp.139-145
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• 2008

Morphological classification of echinoid species has many difficulties because of their phenotypic variations. In the present study, we analyzed morphotypes and partial mitochondrial 12S rDNA sequences of four sea urchin species classified as Pseudocentrotus depressus, Anthocidaris crassispina, Hemicentrotus pulcherrimus and Strongylocentrotus nudus, and unidentified four species collected from the coasts of the East sea. Their genomic DNAs were extracted from gonads and mitochondrial 12S rDNA sequences were amplified by the polymerase chain reaction (PCR) method. The sequence identities among the known four sea urchin species were 87.4-95.6%. The sequence identities among the unidentified four species were 99.4-99.6% and showed the highest homology to S. intermedius(99.8%). Thus, our phylogenetic tree indicates that the unidentified four species belong to S. intermedius.

• Proceedings of the National Institute of Ecology of the Republic of Korea
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• v.1 no.1
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• pp.31-40
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• 2020

The rapid development of technologies in unmanned aerial vehicles (UAVs) has led to their use in various areas. UAVs are mainly used for commercial purposes, but their utilization is increasingly important in other areas because their operation cost is less than satellites and aerial imaging. The utilization of UAVs in the environment/ecology area is relatively new. Therefore, identifying the trends of UAV-related spatial information is significant in basic research for UAV utilization. This study quantitatively identified domestic and international research trends related to UAV utilization and analyzed research areas. An attempt was also made to identify upcoming UAV-related topics in the environment/ecology research field using text mining to analyze the bibliographic information of global research literature. Domestic UAV-related studies were classified into seven clusters where basic research on "UAV technology/industry trends" was abundant, and studies on data collection and analysis through UAV remote sensing technology have increased since 2015. Eight clusters were identified for international studies where the most active research area international was "remote sensing technology/data analysis". In addition, Canopy, Classification, Forest, Leaf Area Index, Normalized Difference Vegetation Index, Temperature, Tree, and Atmosphere appeared as the main keywords related to environment and ecology. The appearance frequencies and association strengths were high because the advancement in UAV optical sensor technology and the rapid development of image processing technology enabled the acquisition of data that could not be obtained from existing spatial information. They are recognized as future research topics as related domestic studies have begun corresponding to international research.

• Journal of Korean Society of Forest Science
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• v.89 no.3
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• pp.378-383
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• 2000

Pinus sylvestris plantations in the Eifel mountains, Germany, were studied and classified phytosociologically. Ecological characteristics(soil, natural regeneration & succession) of the plant communities classified were analyzed and described with emphasis on the forest management. According to soil and topographic characteristics, this plantations were divided into four categories ; Vaccinium myrtillus-Pinus sylvestris community of the adequate moisture area, Pteridium aquilium-Pinus sylvestris community of the moisture area, Molinia caerulea-Pinus sylvestris community of the hardened soil layer B and Festuca tenuifolia-Pinus sylvestris of the dry area. Tree species growing below the shrub layer was analyzed. The results were considered as Vaccinium mytillus-Pinus sylvestris, Pteridium aquline-Pinus sylvestris and Molinia caerulea-Pinus sylvestris will be changed into Fagus sylvatica forest following Quercus forest, and Festuca tenuifilia-Pinus sylvestris will be changed into Pinus sylvestris-dominated climax forest.

• Journal of Intelligence and Information Systems
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• v.14 no.3
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• pp.133-154
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• 2008

The data imbalance problem which can be uncounted in data mining classification problems typically means that there are more or less instances in a class than those in other classes. In order to solve the data imbalance problem, there has been proposed a number of techniques based on re-sampling with replacement, adjusting decision thresholds, and adjusting the cost of the different classes. In this paper, we study the feasibility of the combination usage of the techniques previously proposed to deal with the data imbalance problem, and suggest a combination method using genetic algorithm to find the optimal combination ratio of the techniques. To improve the prediction accuracy of a minority class, we determine the combination ratio based on the F-value of the minority class as the fitness function of genetic algorithm. To compare the performance with those of single techniques and the matrix-style combination of random percentage, we performed experiments using four public datasets which has been generally used to compare the performance of methods for the data imbalance problem. From the results of experiments, we can find the usefulness of the proposed method.

• Industrial Engineering and Management Systems
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• v.14 no.4
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• pp.335-346
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• 2015

The electronic commerce site (EC site) has become an important marketing channel where consumers can purchase many kinds of products; their access logs, including purchase records and browsing histories, are saved in the EC sites' databases. These log data can be utilized for the purpose of web marketing. The customers who purchase many product items are good customers, whereas the other customers, who do not purchase many items, must not be good customers even if they browse many items. If the attributes of good customers and those of other customers are clarified, such information is valuable as input for making a new marketing strategy. Regarding the product items, the characteristics of good items that are bought by many users are valuable information. It is necessary to construct a method to efficiently analyze such characteristics. This paper proposes a new latent class model to analyze both purchasing and browsing histories to make latent item and user clusters. By applying the proposal, an example of data analysis on an EC site is demonstrated. Through the clusters obtained by the proposed latent class model and the classification rule by the decision tree model, new findings are extracted from the data of purchasing and browsing histories.

• The KIPS Transactions:PartD
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• v.11D no.3
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• pp.519-532
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• 2004

With the explosion of bioinformatics data such proteins and genes, biologists need a integrated system to analyze and organize large datasets that interact with heterogeneous types of biological data. In this paper, we propose a integration system based on a mediated data warehouse architecture using a XML model in order to combine protein related data at biology laboratories. A fact constellation model in this system is used at a common model for integration and an integrated schema it translated to a XML schema. In addition, to track source changes and provenance of data in an integrated database employ incremental update and management of sequence version. This paper shows modeling of integration for protein structures, sequences and classification of structures using the proposed system.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.39C no.9
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• pp.811-819
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• 2014

Activity recognition is a key component in identifying the context of a user for providing services based on the application such as medical, entertainment and tactical scenarios. Instead of applying numerous sensor devices, as observed in many previous investigations, we are proposing the use of smartphone with its built-in multimodal sensors as an unobtrusive sensor device for recognition of six physical daily activities. As an improvement to previous works, accelerometer, gyroscope and magnetometer data are fused to recognize activities more reliably. The evaluation indicates that the IBK classifier using window size of 2s with 50% overlapping yields the highest accuracy (i.e., up to 99.33%). To achieve this peak accuracy, simple time-domain and frequency-domain features were extracted from raw sensor data of the smartphone.

• Korean Journal of Environment and Ecology
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• v.29 no.2
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• pp.250-262
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• 2015

This study aims to investigate the characteristics of the vegetation structure in the sectin stretching between the Jilmoi wetlands and the Donghae Observatory and to set the criteria for the basic data for a management plan including restoration afterwards. 12 plots($10m{\times}40m$, $20m{\times}20m$) were set up to analyse the vegetation structure. The analysis of the classification by TWINSPAN and ordination by DCA, importance percentage and property, distribution of diameter of breast height, growth increments of major woody species, species diversity and the physicochemical properties of soil were all analyzed. Vegetation classes were divided into 3 communities, which are community I (Pinus densiflora community), community II (Quercus mongolica community) and community III (Quercus mongolica-Tilia amurensis community). The P. densiflora community declined when competing with Q. mongolica and Fraxinus rhynchophylla and Q. mongolica competed with T. amurensis on an understory layer in Q. mongolica community. Q. mongolica competed with T. amurensis on both canopy and understory layers in Q. mongolica-T. amurensis community. P. densiflora declined and it was assumed to succeed to F. rhynchophylla or T. amurensis through Q. mongolica based on the importance percentage and distribution of the diameter of the breast height of small and middle sized trees. The age of P. densiflora was between 47 to 51 years old and Q. mongolica was 61years old. T. amurensis was 61 years old and the growth of Q. mongolica slowed a little. As the result of Shannon's index of species diversity, community I ranged from 0.9578 to 1.1862, community II ranged from 0.7904 to 1.2286 and community III ranged from 0.8701 to 1.0323. The contents of organic matter and cation were low compared to uncultivated mountain soil and it were analysed to be inappropriate for tree growth.

• Child Health Nursing Research
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• v.18 no.3
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• pp.143-149
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• 2012

Purpose: The aim was to explore the relationship between health status/life style and prevalence of atopic dermatitis in adolescents. Methods: Data from 1,743 adolescents (aged 13 to 18 years) derived from the fourth Korea National Health and Nutrition Examination Survey (KNHANES) were analyzed using binary logistic regression and the classification and regression tree (CART) model. Results: The prevalence rate of atopic dermatitis was 10.3%. Third quartile income class (OR=2.19, 95% CI=1.20-4.00), fair and unhealthy self-rated health (OR=1.49, 95% CI=1.06-2.11; OR= 2.73, 95% CI=1.64-4.55), past or current smoker (OR=0.41, 95% CI=0.20-0.85; OR=0.44, 95% CI=0.21-0.92), and more than average stress (OR=1.43, 95% CI=1.03-1.99) were related with increased prevalence of atopic dermatitis. The high prevalence risk groups for atopic dermatitis were adolescents who perceived themselves to be healthy on self-rated health and had more than average stress and those who perceived themselves to be unhealthy and who never smoked. Conclusion: The results of the study indicate that health status, smoking, and stress are associated with a prevalence risk for adolescent atopic dermatitis in different degrees. Therefore, for control of atopic dermatitis, various interventions for smoking and stress need to be reinforced for the high prevalence atopic dermatitis groups.