Understanding the classification of malocclusion is a crucial issue in Orthodontics. It can also help us to diagnose, treat, and understand malocclusion to establish a standard for definite class of patients. Principal component analysis (PCA) and k-means algorithms have been emerging as data analytic methods for cephalometric measurements, due to their intuitive concepts and application potentials. This study analyzed the macro- and meso-scale classification structure and feature basis vectors of 1020 (415 male, 605 female; mean age, 25 years) orthodontic patients using statistical preprocessing, PCA, random matrix theory (RMT) and k-means algorithms. RMT results show that 7 principal components (PCs) are significant standard in the extraction of features. Using k-means algorithms, 3 and 6 clusters were identified and the axes of PC1~3 were determined to be significant for patient classification. Macro-scale classification denotes skeletal Class I, II, III and PC1 means anteroposterior discrepancy of the maxilla and mandible and mandibular position. PC2 and PC3 means vertical pattern and maxillary position respectively; they played significant roles in the meso-scale classification. In conclusion, the typical patient profile (TPP) of each class showed that the data-based classification corresponds with the clinical classification of orthodontic patients. This data-based study can provide insight into the development of new diagnostic classifications.

This paper on language learner strategies utilizes a little used quantitative, datamining technique called cluster analysis to investigate characteristics of groups of South Korean learners of English. After 71 students in three first-year university liberal arts English conversation courses completed the Strategy Inventory for Language Learning (SILL), and the number of learning strategies was reduced from 50 to 26 based on standard deviation (SD) results, the non-hierarchical (K-means) 3-cluster procedure was applied to the self-reported data. Following statistical analysis, each of the three cluster groups could be profiled according to achievement scores. At this point, six items emerged as particularly meaningful with regard to the latter, including direct strategies (a memory one and a cognitive one) and indirect strategies (two affective and two metacognitive). These strategies and their significance with reference to the local context as well as results previously reported in the literature are discussed. Finally, limitations of the study and implications for future research using cluster analysis are reported.

Cluster of differentiation (CD) 24 or heat stable antigen 24 (HSA) molecule is a mucin-type glycoprotein attached to the cell surface by glycosylphosphatidylinositol (GPI)-anchor, promoting adhesive interactions between cells or in extracellular matrix. The aim of this study was to determine the not yet fully identified porcine CD24 gene and protein structure using computational analysis and to validate variants reported in exons of CD24 gene using direct sequencing. A total of 59 samples belonging to Yorkshire, Landrace, Berkshire, Jeju black pig and wild boar were used in the study. Human CD24 mRNA sequences were used as a reference and subjected to BLAST searches to retrieve the orthologous expressed sequence tags (ESTs) or cDNA sequences against NCBI and Ensemble databases. Assembled ESTs and retrieved cDNA sequences for the porcine CD24 gene were used for specific BLAST search to determine its genomic structure. We found porcine CD24 gene to consist of two exons and a relatively long intron. Second exon of porcine CD24 gene had a long 3’ untranslated region (UTR) and was very similar to that of human, mouse, rat, and sheep. The sequence homology of porcine CD24 protein was 65.38-84.62%, when analyzed with amino acid sequences of rat, mouse, human, cattle, and sheep CD24 protein. N-terminal signal sequence, O-glycosylation sites and GPI-anchoring signal sites were also predicted in pig, which showed these motifs to be evolutionary conserved across the species. Variant analysis in exonic regions of porcine CD24 among the multiple breeds showed that only second exon contained eight SNPs and three insertions in a 3’ UTR. Taken together, this study reports putative porcine CD24 gene and its protein structure using in silico approaches, which will be helpful for any further functional studies.

An objective classification of commercial thickened foods was studied for Korean elderly people with swallowing difficulty as based on rheological properties. A total of 16 commercial products (grain porridges, vegetable porridges, meat porridges, fish and shellfishes porridges, nut porridges) were measured using a stress-controlled rheometer with stainless steel plate-plate geometry and building material cell. Joint consideration has been made of viscous behavior (flow and thixotropy) and viscoelastic behavior (oscillatory testing). Rheological measurements were fitted to different rheological and empirical mathematical models, and a total of 11 parameters were generated. Based on these parameters and the use of fuzzy clustering and the c-means method, an objective classification of all the products was obtained. 16 commercial products were divided to 3 clusters. Each class has been defined from the parameters of the centroids generated by the classification method used - thus allowing us to know the common rheological characteristics of any of the products belonging to a given class. The results of this classification encourage further to develop of the new products for Korean elderly people.

본 논문은 개인의 비합리적인 이타주의 행동을 설명하는 규범활성화모델을 활용하여 공정무역제품 구매행동을 촉진하는 개인적, 규범적, 문화적 요인을 통합적으로 다루고 있다. 모델 관련, 예기된 감정(예기된 자부심과 예기된 죄책감)과 두 가지 상충하는 개인가치(박애주의 가치와 권력 가치)를 공정무역 관련 개인규범 활성화 선행요인으 로 개념화 하였다. 그리고 활성화된 개인규범이 공정무역제품 구매행동에 영향을 주는 것으로 보았고 특히 이들 간의 관계를 문화 클러스터(유교, 라틴 유럽)가 조절하는 것으로 개념화 하였다. 구조방정식을 통해 얻은 실증결 과는 예기된 자부심이 개인규범에 미치는 영향력이 예기된 죄책감 보다 크고, 상충되는 두 가지 개인가치 중 이 타적 가치인 박애주의 가치만이 개인규범에 유의한 영향을 미치는 것으로 나타났다. 그리고 활성화된 개인규범은 공정무역제품구매 행동에 유의한 영향을 주는 것으로 조사되었다. 문화 클러스터의 조절효과는 다집단비교 구조 방정식을 통해 분석하였다. 검증결과, 해당 경로에 대한 영향력이 라틴 유럽 클러스터 보다 유교 클러스터에서 더 강한 것으로 나타났다. 이러한 결과는 유교 클러스터가 라틴 유럽 클러스터에 비해 직접적인 비용지불에 따른 자기희생 정도가 더 크고, 사회 구성원 기대에 상응하는 도의적 의무감을 강하게 느끼기 때문에 공정무역제품 구 매 행위가 더 강하게 나타난 것으로 해석 가능하다. 본 논문은 규범활성화모델을 활용하여 공정무역제품 구매행 동을 비교 문화적 관점에서 접근하여 윤리적 소비자의 의사결정과정을 실증적으로 구명했다는데 의의가 있다.