Data on patent and scientific paper is considered as a useful information source for analyzing technological information and has been widely utilized. Technology big data is analyzed in various ways to identify the latest technological trends and predict future promising technologies. Clustering is one of the ways to discover new features by creating groups from technology big data. Patent includes refined bibliographic information such as patent classification code whereas scientific paper does not have appropriate bibliographic information for clustering. This research proposes a new approach for clustering data of scientific paper by utilizing reference titles in each scientific paper. In this approach, the reference titles are considered as textual information because each reference consists of the title of the paper that represents the core content of the paper. We collected the scientific paper data, extracted the title of the reference, and conducted clustering by measuring the text-based similarity. The results from the proposed approach are compared with the results using existing methodologies that one is the approach utilizing textual information from titles and abstracts and the other one is a citation-based approach. The suggested approach in this paper shows statistically significant difference compared to the existing approaches and it shows better clustering performance. The proposed approach will be considered as a useful method for clustering scientific papers.
This study investigated the nutrition knowledge, dietary habits, and food intake frequency according to hospitalization after breast cancer surgery and experience of breast cancer among female adults residing in the Bucheon area. Subjects were 52 female breast cancer survivors 27 in the hospitalization group (HG) and 25 in the non-hospitalization group (non-HG)] and 52 controls. Data included the results of self-administered questionnaires, as well as anthropometric data and blood biochemical values of breast cancer survivors collected from electronic medical records. Statistical analysis was performed using SPSS 20.0 program. Nutrition knowledge and dietary habits revealed no significant differences between HG and non-HG, but intake frequency of root and tuber crops and kimchi was significantly higher in the HG group than the non-HG group (p<0.05). According to experience of breast cancer, total scores of nutrition knowledge among survivors (8.2) were significantly higher than those of the control group (6.3) (p<0.001). Fish and shellfish and fruit intake frequencies were significantly higher in the survivors group, whereas intake frequency of fast food, convenience food, and alcohol was significantly lower compared to the control group. Overall, these findings indicate it is necessary to develop and spread nutrition education guidelines to prevent the occurrence and recurrence of breast cancer.
본 연구에서는 입계의 성질을 이용한 PTCR 재료에 입계 modifier로서 Bi2O3와 BN을 첨가하고 입계의 미세구조와 결함농도를 변화시켜 이에 따른 소결 및 전기적 특성변화를 TMA, XRD, 복합 임피던스방법 등을 이용하여 해석하였다. 실험 결과 Y이 도우핑된 BaTiO3 PTCR 재료에 Bi2O3를 첨가하였을때 약 0.1mol%까지 고용이 되는 것으로 밝혀졌다. Bi2O3를 고용한계 이하로 첨가시에는 생성되는 vacancy등의 결함으로 말미암아 Y-BaTiO3의 치밀화가 촉진되었으나, 그 이상 첨가하면 치밀화 뿐만 아니라 결정립 성장도 억제되었다.Bi2O3 결정립 내부에 Ba와 Ti vacancy가 동시에 생길 수 있어 고온저항이 높아짐을 알 수 있었다. BN은 BaTiO3에 고용이 되지 않는 것으로 밝혀졌으며 B2O/wub/3를 주성분으로한 액상형성으로 인하여 저온에서의 급격한 치밀화가 관찰되었다. 또 Ba-Y-Ti-B-O의 비정질 상이 tripie junction에 존재함으로서 상온저항이 크게 변화하였으며, PTCR jump도 높아졌다.
용해와 주조, 압출과 열처리 기술의개선으로 고강도, 고파괴인성의 AI-Li-Cu 합금(2090 AI합금)을 제조하였다. 또한 준 산업용 규모(20kg)의 잉고트 제조공정을 확립하기 위해서 (1)선 (2)기계적 성질들에 미치는 열처리 영향 (3) 인장시험, 파괴인성 시험(KIc) 및 피로균열 전파시계를 갖고 있으며 최종 제품의 인장강도는 최대시효 조건에서 534MPa부터 566MPa이었고 연신율은 9%에서 11.9%정도였다. C-T 시편을 이용한 파괴인성 시험 결과 최대시효 조건에서 평면변형 파괴인성 (KIc)값은 39MPa√m였고 미시효 조건에서는 23MPa√m였다. 또한 0.1, 0.3, 0.5의 하중비에서 피로균열 전파시험을 행하였을때 임계응력 확대계수(δKth)는 각각 6.0, 5.3, 4.3 MPa√m이었다.