• Korean Journal of Child Studies
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• v.18 no.2
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• pp.311-331
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• 1997

This study investigated the relationship between preschool children's social competence and perceived social support. The subjects were 85 children enrolled in 10 kindergartens and nurseries located in Seoul. Social support was assessed by children themselves with a social support dialogue Cask, "My Family and Friends," developed by Reid, Lamdegman, and Jaccard (1989). This task consists of 12 dialogues based on Vygotskian principles. Social competency was assessed by teachers with a slightly modified version of Song's Iowa Social Competency Scale (ISCS). The data were analyzed by frequencies percentiles, mean, one-way ANOVAs, and Pearson's correlations. Results showed that (1) Children perceived parents to be the best multi-purpose social providers: mothers for emotional support and fathers for instrumental support. (2) Children with unemployed mothers perceived higher maternal emotional, informational, and instrumental support than children with employed mothers. (3) Middle-class children perceived higher friendship support than upper-or lower-class children. (4) Friendship support was the one variable most significantly related to children's social competence.

• Journal of information and communication convergence engineering
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• v.13 no.2
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• pp.74-80
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• 2015

In cognitive radios, spectrum sensing plays an important role in accurately detecting the presence or absence of a licensed user. However, the intervention of malicious users (MUs) degrades the performance of spectrum sensing. Such users manipulate the local results and send falsified data to the data fusion center; this process is called spectrum sensing data falsification (SSDF). Thus, MUs degrade the spectrum sensing performance and increase uncertainty issues. In this paper, we propose a method based on the Hausdorff distance and a similarity measure matrix to measure the difference between the normal user evidence and the malicious user evidence. In addition, we use the Dempster-Shafer theory to combine the sets of evidence from each normal user evidence. We compare the proposed method with the k-means and Jaccard distance methods for malicious user detection. Simulation results show that the proposed method is effective against an SSDF attack.

• Proceedings of the Korea Information Processing Society Conference
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• 2019.05a
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• pp.36-39
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• 2019

데이터 마이닝에서 클러스터링은 서로 유사한 특징을 갖는 데이터들을 동일한 클래스로 분류하는 방법이다. 클러스터링에는 다양한 방법이 존재하지만 대표적으로 집합으로 표현된 데이터들의 유사도를 측정하기 위해서는 자카드 유사도(Jaccard Similarity)를 이용한다. 자카드 유사도는 서로 다른 집합 간의 공통된 부분을 상대적으로 평가하여 유사도를 측정하는 방법이다. 그러나 최근에는 데이터를 저장할 수 있는 기술과 매체의 발전으로 표현할 수 있는 데이터의 영역과 범위는 발전되고 있기 때문에 많은 연산과 시간의 비용이 발생하게 된다. 이를 해결하기 위해서 두 데이터의 표본의 유사도를 통해 실제 데이터들의 유사도를 추정할 수 있는 Min-Hash 가 제안되었다. 본 논문에서는 이를 활용하여 집합의 영역을 다중 집합(Multiset)으로 확장하여 중복되는 값을 가질 수 있는 두 데이터 간의 유사도를 효율적으로 추정할 수 있는 Min-Max Hash 를 제안한다.

• Proceedings of the Korea Information Processing Society Conference
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• 2019.10a
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• pp.657-659
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• 2019

본 논문에서는 피부 이미지에서 건선 병변만을 가장 효과적으로 분할 할 수 있는 분할기법 선별을 목표로 한다. Interactive graph cuts (IGC)와 Level set method (LSM)를 사용하여 건선 영역을 분할한 후 Jaccard Index (JI)와 Dice Similarity Coefficient (DSC)을 사용하여 건선 영역에 효과적인 분할 방법을 제안한다.

• Journal of the Korea Society of Computer and Information
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• v.23 no.12
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• pp.219-226
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• 2018

Collaborative filtering has been most popular approach to recommend items in online recommender systems. However, collaborative filtering is known to suffer from data sparsity problem. As a simple way to overcome this problem in literature, Jaccard index has been adopted to combine with the existing similarity measures. We analyze performance of such combination in various data environments. We also find optimal weights of factors in the combination using a genetic algorithm to formulate a similarity measure. Furthermore, optimal weights are searched for each user independently, in order to reflect each user's different rating behavior. Performance of the resulting personalized similarity measure is examined using two datasets with different data characteristics. It presents overall superiority to previous measures in terms of recommendation and prediction qualities regardless of the characteristics of the data environment.

• International conference on construction engineering and project management
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• 2022.06a
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• pp.808-813
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• 2022

This study presents the problems of data imbalance, varying difficulties across target objects, and small objects in construction object segmentation for far-field monitoring and utilize compound loss functions to address it. Construction site scenes of assembling scaffolds were analyzed to test the effectiveness of compound loss functions for five construction object classes---workers, hardhats, harnesses, straps, hooks. The challenging problem was mitigated by employing a focal and Jaccard loss terms in the original loss function of LinkNet segmentation model. The findings indicates the importance of the loss function design for model performance on construction site scenes for far-field monitoring.

• Asia pacific journal of information systems
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• v.18 no.1
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• pp.79-96
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• 2008

One of the roles of the Semantic Web services is to execute dynamic intra-organizational services including the integration and interoperation of business processes. Since different organizations design their processes differently, the retrieval of similar semantic business processes is necessary in order to support inter-organizational collaborations. Most approaches for finding services that have certain features and support certain business processes have relied on some type of logical reasoning and exact matching. This paper presents our approach of using imprecise matching for expanding results from an exact matching engine to query the OWL(Web Ontology Language) MIT Process Handbook. MIT Process Handbook is an electronic repository of best-practice business processes. The Handbook is intended to help people: (1) redesigning organizational processes, (2) inventing new processes, and (3) sharing ideas about organizational practices. In order to use the MIT Process Handbook for process retrieval experiments, we had to export it into an OWL-based format. We model the Process Handbook meta-model in OWL and export the processes in the Handbook as instances of the meta-model. Next, we need to find a sizable number of queries and their corresponding correct answers in the Process Handbook. Many previous studies devised artificial dataset composed of randomly generated numbers without real meaning and used subjective ratings for correct answers and similarity values between processes. To generate a semantic-preserving test data set, we create 20 variants for each target process that are syntactically different but semantically equivalent using mutation operators. These variants represent the correct answers of the target process. We devise diverse similarity algorithms based on values of process attributes and structures of business processes. We use simple similarity algorithms for text retrieval such as TF-IDF and Levenshtein edit distance to devise our approaches, and utilize tree edit distance measure because semantic processes are appeared to have a graph structure. Also, we design similarity algorithms considering similarity of process structure such as part process, goal, and exception. Since we can identify relationships between semantic process and its subcomponents, this information can be utilized for calculating similarities between processes. Dice's coefficient and Jaccard similarity measures are utilized to calculate portion of overlaps between processes in diverse ways. We perform retrieval experiments to compare the performance of the devised similarity algorithms. We measure the retrieval performance in terms of precision, recall and F measure? the harmonic mean of precision and recall. The tree edit distance shows the poorest performance in terms of all measures. TF-IDF and the method incorporating TF-IDF measure and Levenshtein edit distance show better performances than other devised methods. These two measures are focused on similarity between name and descriptions of process. In addition, we calculate rank correlation coefficient, Kendall's tau b, between the number of process mutations and ranking of similarity values among the mutation sets. In this experiment, similarity measures based on process structure, such as Dice's, Jaccard, and derivatives of these measures, show greater coefficient than measures based on values of process attributes. However, the Lev-TFIDF-JaccardAll measure considering process structure and attributes' values together shows reasonably better performances in these two experiments. For retrieving semantic process, we can think that it's better to consider diverse aspects of process similarity such as process structure and values of process attributes. We generate semantic process data and its dataset for retrieval experiment from MIT Process Handbook repository. We suggest imprecise query algorithms that expand retrieval results from exact matching engine such as SPARQL, and compare the retrieval performances of the similarity algorithms. For the limitations and future work, we need to perform experiments with other dataset from other domain. And, since there are many similarity values from diverse measures, we may find better ways to identify relevant processes by applying these values simultaneously.

• Korean Journal of Environment and Ecology
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• v.34 no.5
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• pp.436-445
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• 2020

The number of protected areas has been steadily increased in Korea to achieve Aichi Target 11, and there are studies on potential protected areas that required additional designation. However, there has been an insufficient assessment of the complementarity of protected areas to conserve biodiversity effectively. This study identified the potential habitat areas using the species distribution model for plant species from the 3rd National Ecosystem Survey and compared the plant species abundance in the existing protected area and the potential protected areas using the similarity indices, such as the Jaccard index, Sorenson index, and Bray-Curtis index. As a result, we found that the complementarity of the existing protected areas and most potential protected areas were low, leading to the preservation of similar plant species. Only the buffer zone for Korea National Arboretum had high complementarity and thus is important to conserve some species with the other protected areas. This study confirmed that it was necessary to select additional protected areas outside the existing or potential protected areas to protect plant species with a low inclusion ratio of potential habitats within the protected area. This study is significant because it identified the ecological representativeness of each protected area to examine if the individual protected area can conserve unique and various species and proposed a method of finding candidate areas for additional conservation spatially. The findings of this study can be a valuable reference for the qualitative improvement of protected areas through the complementarity assessments, including animals and the effectiveness assessment study of protected areas using the National Ecosystem Survey data in the future.

• Journal of Life Science
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• v.23 no.6
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• pp.721-727
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• 2013

The objective of this study was to evaluate the suitability of microsatellite markers for variety identification in 42 apple varieties. For microsatellite analysis, 305 primer pairs were screened in 8 varieties and twenty six primer pairs showed polymorphism with clear band pattern and repetitive reproducibility. A total of 165 polymorphic amplified fragments were obtained in 42 varieties using 26 markers. Two to twelve alleles were detected for each locus with an average of 6.4 alleles per locus. A value of polymorphism information content (PIC) ranged from 0.461 to 0.849 with an average of 0.665. A total of 165 marker loci were used to calculate Jaccard's distance coefficients using unweighted pair-group method with arithmetical average (UPGMA) cluster analysis. Genetic distance of cluster ranged from 0.27 to 1.00. Analysis of genetic relationship revealed that these 26 microsatellite marker sets discriminated a total of 41 varieties except for 1 variety among 42 varieties. These markers will be utilized as molecular data in variety identification of apple.

• Journal of Korean Society of Forest Science
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• v.109 no.2
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• pp.145-156
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• 2020

In 2000 and 2018, phytosociological surveys were carried out in the forest vegetation of Mt. Yeompo, a representative isolated urban forest in Ulsan city. The trends of change in forest structure, composition, and spatial distribution were compared between years. Total percent coverage per 100 squaremeters of forest vegetation was similar, but natural vegetation showed a 9% increase. The importance of constituent species changed slightly. Specifically, Lindera erythrocarpa and Styrax japonicus showed very high growth rates of 835% and 269%, respectively. Species richness (S) and diversity (H') decreased by about 22% and 8%, respectively. Both S and H' showed slightly higher rates of decrease in artificial compared with natural vegetation. The constituent species life form spectrums were the same in 2000 and 2018 as 'MM-R5-D4-e'. The similarity (Jaccard coefficient) in the species composition of the forest vegetation was almost homogeneous at approximately 75%. The number of indicator species decreased from 16 species in 2000 to 7 species in 2018. This decrease was mostly due to a decline in herbaceous plants, such as Hemicryptophytes, Geophytes, and Therophytes, which are sensitive to disturbances. The spatial distribution of forest vegetation did not change significantly. The number of forest landscape elements (patches) increased by approximately 25% from 537 in 2000 to 721 in 2018, while the average size decreased by about 20% from 1.28 ha in 2000 to 1.03 ha in 2018.