• 제목/요약/키워드: 1001

검색결과 520건 처리시간 0.028초

Ultimate strength behavior of steel-concrete-steel sandwich beams with ultra-lightweight cement composite, Part 2: Finite element analysis

  • Yan, Jia-Bao;Liew, J.Y. Richard;Zhang, Min-Hong
    • Steel and Composite Structures
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    • 제18권4호
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    • pp.1001-1021
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    • 2015
  • Ultra-lightweight cement composite (ULCC) with a compressive strength of 60 MPa and density of $1,450kg/m^3$ has been developed and used in the steel-concrete-steel (SCS) sandwich structures. This paper investigates the structural performances of SCS sandwich composite beams with ULCC as filled material. Overlapped headed shear studs were used to provide shear and tensile bond between the face plate and the lightweight core. Three-dimensional nonlinear finite element (FE) model was developed for the ultimate strength analysis of such SCS sandwich composite beams. The accuracy of the FE analysis was established by comparing the predicted results with the quasi-static tests on the SCS sandwich beams. The FE model was also applied to the nonlinear analysis on curved SCS sandwich beam and shells and the SCS sandwich beams with J-hook connectors and different concrete core including ULCC, lightweight concrete (LWC) and normal weight concrete (NWC). Validations were also carried out to check the accuracy of the FE analysis on the SCS sandwich beams with J-hook connectors and curved SCS sandwich structure. Finally, recommended FE analysis procedures were given.

스마트 기기 환경에서 전력 신호 분석을 통한 프라이버시 침해 위협 (Threatening privacy by identifying appliances and the pattern of the usage from electric signal data)

  • 조재연;윤지원
    • 정보보호학회논문지
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    • 제25권5호
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    • pp.1001-1009
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    • 2015
  • 스마트 그리드 안에서 고안된 스마트 미터는 우리가 사용하는 전력 신호를 실시간으로 데이터화해서 전력 공급단의 메인 서버로 전송한다. 이를 통해 전력 관리의 효율성은 증가한 반면, 사용자의 정보를 담은 데이터의 보안 문제가 새로운 위협으로 부상하였다. 본 논문은 스마트 미터에서 추출한 전력 데이터를 통해 가정 내 기기의 식별 및 기기별 사용패턴에 대한 추론을 보안 관점에서 해석함으로써 스마트 기기 환경에서 데이터 노출의 위협을 지적한다. 주성분분석(Principal Component Analysis)으로 데이터의 특징을 추출하였고 k-근접 이웃(k- Nearest Neighbor)분류기로 기기를 식별하고 기기상태를 추론하였으며, 검증방법으로는 10차 교차검증(10-fold Cross Validation)을 활용하였다.

중·고등학생의 여름용 교복 만족도 및 치수적합성에 관한 연구 (Research on the Middle & High School Students' Satisfaction and Fitness of Sizing System for Summer School Uniform)

  • 이혜주;조지현
    • 한국의류산업학회지
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    • 제14권6호
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    • pp.1001-1009
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    • 2012
  • The purpose of this study was to provide information on how to improve both the satisfaction and the current sizing system for the school summer uniform focused on middle and high school students. In order to collect the data, a questionnaire was administered to middle and high school students, and 1,153 data were analyzed. For the satisfaction of their school uniform, there were statistical differences in mean of gender in the design(upper garment) and design & activity(lower garment). On the other hand, students' evaluation of summer school uniform was significantly different in the upper garment(textile, design, activity), and lower garment(design, activity) by school age. For the evaluation of sizing fitness, the length and width of the summer upper garment(blouse/shirts) and the length and width of the summer garments( pants/skirts) were statistical differences in mean of gender or sexuality whereas there were significant differences in the summer upper garment(length, width, the length of sleeve, the width of sleeve, armhole) and the summer lower garment(length, width) by school age.

공업용 순 티타늄의 피로거동에서 정류균열에 관한 연구 (A Study on Non-propagating Crack in Fatigue Behavior of Pure Titanium)

  • 김동열;김진학;김민건
    • 대한기계학회논문집A
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    • 제24권4호
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    • pp.1001-1006
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    • 2000
  • To verify the existing theory, non-propagating crack(NPC) does not exist in Ti which fulfills the good conditions for being of NPC, NPC detection in Ti was tried out. Also, the conception of fatigue limit in Ti and a main cause for NPC being were inquired. NPC was detected in both sharp notch root ( $\rho$=0.02mm) and micro pit (diameter = 0.25mm) which held fast to the end under stressing of fatigue limit. Therefore, the existing theory was identified as mistake. But, NPC can not be detected in smooth specimen. This fact would be due to the presumption that NPC is very small or crack does not initiate in smooth specimen. Anyway, the fatigue limit of Ti does not correspond to critical stress of crack initiation but correspond to critical stress of NPC growth. Measurement on the COD of NPC in Ti showed that the crack tip was closed even under the peak stress level at fatigue limit. But, after stress relieving annealing crack tip was opened. Consequently, compressive residual stress which is induced around the crack tip is considered to be the factor causing the NPC being.

데이터 전송 효율을 고려한 4비트행×4비트열 2 바이트 문자 부호화 규칙에 관한 연구 (Coding Rule of Characters by 2 bytes with 4×4 bits to Improve the Transmission Efficiency in Data Communications)

  • 홍완표
    • 한국항행학회논문지
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    • 제15권5호
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    • pp.749-756
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    • 2011
  • 본 논문은 컴퓨터 등 정보기기에 입력되는 문자나 기호의 부호화 규칙을 제시하였다. 문자나 부호를 부호화할 때 본 논문에서 제시하는 규칙을 적용할 경우, 데이터를 전송로에 전송할 때 회선부호화과정에서 발생하는 스크램블링의 발생으로 인한 전송효율이 떨어지는 것을 감소시킬 수 있다. 본 논문에서는 4비트열 ${\times}$ 4비트행의 2 바이트 부호화에 대한 것을 고찰하였다. 본 논문에서는 2바이트(16비트) 원천부호체계로 KS X 1001에 규격화되어 있는 로마 문자용 부호집합에 대한 부호체계를 참고로 하였다.

IEEE 802.11 시스템에서 경쟁 터미널 수 추정기법 성능분석 (칼만필터 vs. H Infinity Filter) (Performance Comparison in Estimating the Number of Competing Terminals in IEEE 802.11 Networks (Kalman vs. H Infinity Filter))

  • 김태진;임재찬;홍대형
    • 한국통신학회논문지
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    • 제37A권11호
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    • pp.1001-1011
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    • 2012
  • 본 논문에서는 IEEE 802.11 시스템에서 경쟁 중인 터미널 수를 추정하고 이를 반영할 때 시스템 성능에 미치는 영향을 분석한다. IEEE 802.11 시스템에서는 터미널간의 다중 접근의 방법으로 DCF (Distributed Coordination Function)를 이용하고 있으며 경쟁하는 터미널 수를 정확하게 추정하여 반영하는 것이 시스템 throughput 증가하는데 중요한 요소가 된다. 본 논문에서는 터미널 수를 추정하는 방법으로 노이즈 정보가 필요하지 않는 Extended H Infinity Filter (EHIF)를 이용하여 터미널 수를 추정하는 방법을 제안한다. 경쟁하는 터미널의 수가 saturated되는 경우와 non-saturated되는 네트워크 환경에서 EHIF가 기존의 Extended Kalman Filter (EKF) 방법보다 좋은 성능을 가짐을 모의실험을 통해 확인하였고 이를 정량적으로 분석하였다.

Patterns of Anger Expression among Middle-aged Korean Women: Q methodology

  • Lee, Yong Mi;Kim, Geun Myun
    • 대한간호학회지
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    • 제42권7호
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    • pp.1001-1008
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    • 2012
  • Purpose: The purpose of this study was to identify the characteristics of anger expression in middle-aged Korean women by categorizing their patterns of expression while considering the complexity and multidimensionality of anger, and by investigating the characteristics relative to the patterns. Methods: The research design was a descriptive design using Q methodology, which is a method of measuring subjectivity. A convenience sample of 42 participants aged 40-60 years and living in the community in Korea was recruited. The PC-QUANL software program (a factor analysis program for the Q technique) was used to analyze the Q-sort data. Results: Four factors were extracted that described different expressions of anger among middle-aged Korean women; these factors explained 50.1% of the total variance. The frames of reference of the four factors were a) direct diversion, b) silent masking with remaining anger, c) self digestion, and d) controlling anger with objectification. Conclusion: In this study has identified patterns and characteristics of anger expression among middle-aged Korean women were identified, which will aid the development of effective anger-management programs for controlling anger in this population. In future studies, it would be helpful to investigate how the patterns of anger expression established herein are associated with specific health problems such as cardiovascular disorder and cancer.