• 제목/요약/키워드: quasi-experiment research

검색결과 89건 처리시간 0.02초

준불연 외단열시스템의 역학적 특성에 관한 연구 (Mechanical Properties of External Thermal Insulation Composite System with Quasi-Non-Combustible Performance)

  • 최기선;하수경;오근영;박금성;류화성
    • 한국건축시공학회지
    • /
    • 제21권5호
    • /
    • pp.507-518
    • /
    • 2021
  • 외단열시스템에서 준불연 성능을 확보한 부착식 탄산칼슘계 복합단열판은 효과적인 단열성능과 화재안전성을 강화한 것으로, 본 연구에서는 준불연 복합단열판을 대상으로 부착식 준불연 외단열시스템의 구조설계 기초데이터를 확보하기 위하여 복합단열판 및 구성재의 역학적 시험을 수행하였다. 국내외 시험규격을 참조하여 시험체를 제작하였으며, 인장강도, 압축강도, 굴곡강도, 전단강도를 시험 평가하였다. 시험결과로부터 준불연 복합단열판의 강도특성치를 도출하였고, 현행 KS M ISO 4898에서 제시하는 최소 요구물성을 확보하고 있는 것을 검증하였다. 또한, 본 연구에서 사용한 준불연 외단열시스템은 지속적 중량 하중을 받지 않는 벽체의 외단열시스템으로 사용이 가능한 것을 확인하였다.

Research on Transferring the National Height System to the Island

  • Liu, Yanxiong;Zhou, Xinghua;Peng, Lin;Wu, Yongtong
    • 한국항해항만학회:학술대회논문집
    • /
    • 한국항해항만학회 2006년도 International Symposium on GPS/GNSS Vol.1
    • /
    • pp.425-427
    • /
    • 2006
  • It is quite difficult to transfer the National Height System 1985 to the island in China. In the study, one feasible and alternative way, which measures synchronally the tide variation at the island and the coast , is firstly introduced. Then, a new method is proposed. This new method combines GPS technique and Quasi-Geoid Determination technique (GQGD). It needs gravity data, GPS data, leveling data and DEM data, together with complex calculation method and the Earth gravity model. After describing the mathematical model and presenting the calculational steps, one experiment has been shown that this method is valid and can achieve accuracy up to 5 cm for the normal height, compared with the results both from the tidal observation and height approximation. Some suggestion is also given in the end.

  • PDF

복합재 튜브를 이용한 고속 열차의 에너지 흡수장치에 대한 실험 및 수치해석 연구 (Experimental and Numerical Studies on Composite Tubes for the Energy Absorber of High-speed Train)

  • ;장홍규;신재환;손유나;김천곤
    • Composites Research
    • /
    • 제24권1호
    • /
    • pp.1-9
    • /
    • 2011
  • 본 논문에서는 복합재료 튜브를 이용한 고속 열차의 에너지 흡수장치에 대한 실험 및 수치 해석에 관한 연구를 수행하였다. 논문의 목적은 에너지 흡수장치에 대한 최적의 적층(lay-up) 형태를 알아내는 것으로, quasi static method를 이용한 네 가지 적층 형태에 대한 실험을 수행 하였다: $[0/45/90/-45]_4$, $[0]_{16}$, $[0/90]_8$, $[0/30/-30]_5$, 실험을 위해 초기 파괴 시작점을 생성하고, 일정 방향으로 진행되는 파괴를 만들기 위해 베벨 엣지(bevel edge)와 노치 엣지(notch edge)의 두 가지 트리거링 방법을 이용하였다. 저속 충돌실험 결과 $[0/45/90/-45]_4$의 적층 형태가 다른 방법과 비교해서 가장 좋은 에너지 흡수 결과를 보여주였다. 수치해석을 위해 LS-DYNA 프로그램의 변수 분석(parametric analysis)을 통해 가장 적합한 복합재료의 quasi static 실험 시뮬레이션 방법 연구를 수행하였다. 움직이는 벽이 복합재 튜브에 저속 충돌하는 모델을 가정하여 해석을 수행하였으며, 실험값과 수치해석 결과의 비교를 통해 비슷한 경향을 보임을 확인 하였다. 특히 TFAIL과 mass scaling factor를 조절하며 수행하는 변수 분석은 LS-DYNA에서 복합재 튜브의 quasi static 실험을 시뮬레이션 하는 능력과 한계를 보여준다.

해상 양식시설의 계류시스템 실험 및 해석 (Experiment and Analysis of Mooring System for Floating Fish Cage)

  • 김진하;김현주;홍섭
    • 한국수산과학회지
    • /
    • 제34권6호
    • /
    • pp.661-665
    • /
    • 2001
  • 해상가두리의 안정성 및 기능성 향상을 위한 최적 계류시스템을 개발하기 위하여 천해역에 적합한 계류시스템을 검토하여 유연부 이 계류시스템을 선정하였다. 이를 위한 해석프로그램을 정립하고, 수리모형실험 결과와 비교하였다. 해석프로그램의 타당성을 확인 한 후, 적용할 만한 계류시스템을 구성하고 수치계산을 통하여 해상가두리를 위한 적정 계류시스템을 제시하였다. 해상가두리의 계류시스템은 유연부이 계류시스템이 권장되며, 계류배치는 탁월 외력환경과 일치하는 방향으로 하고, 수평계류삭인 나일론 로프는 해상가두리 길이의 0.5배 이상, 경사 와이어 로프는 수심의 2배 이상이 바람직한 것으로 나타났다. 또한, 중간부 이의 증설은 계류장력 및 표류변위를 감소시키는 효과를 가질 것으로 판단된다. 차후, 해상가두리의 동적응답 특성을 계류시스템 해석모델의 개발과 계류시스템의 설계가 요구된다.

  • PDF

점성 손실모델 도입에 의한 축류 압축기 준 3차원 압축성 유동해석 (A Study on the Quasi-3-Dimensional Compressible Flow Calculation by Introduction of Viscous Loss Model in Axial-Flow Compressor)

  • 조강래;이진호;김주환
    • 대한기계학회논문집
    • /
    • 제13권5호
    • /
    • pp.1044-1051
    • /
    • 1989
  • 본 연구에서는 Wu가 제시한 수학적 모델에 기초를 둔 비점성 준3차원 유동해 석에 실제 유체의 점성효과 및 2차유동 등에 의해 발생하는 손실들을 손실모델로 반영하여 그 타당성 유무를 검토하는 데 목적을 두었다.

Hybrid HMM for Transitional Gesture Classification in Thai Sign Language Translation

  • Jaruwanawat, Arunee;Chotikakamthorn, Nopporn;Werapan, Worawit
    • 제어로봇시스템학회:학술대회논문집
    • /
    • 제어로봇시스템학회 2004년도 ICCAS
    • /
    • pp.1106-1110
    • /
    • 2004
  • A human sign language is generally composed of both static and dynamic gestures. Each gesture is represented by a hand shape, its position, and hand movement (for a dynamic gesture). One of the problems found in automated sign language translation is on segmenting a hand movement that is part of a transitional movement from one hand gesture to another. This transitional gesture conveys no meaning, but serves as a connecting period between two consecutive gestures. Based on the observation that many dynamic gestures as appeared in Thai sign language dictionary are of quasi-periodic nature, a method was developed to differentiate between a (meaningful) dynamic gesture and a transitional movement. However, there are some meaningful dynamic gestures that are of non-periodic nature. Those gestures cannot be distinguished from a transitional movement by using the signal quasi-periodicity. This paper proposes a hybrid method using a combination of the periodicity-based gesture segmentation method with a HMM-based gesture classifier. The HMM classifier is used here to detect dynamic signs of non-periodic nature. Combined with the periodic-based gesture segmentation method, this hybrid scheme can be used to identify segments of a transitional movement. In addition, due to the use of quasi-periodic nature of many dynamic sign gestures, dimensionality of the HMM part of the proposed method is significantly reduced, resulting in computational saving as compared with a standard HMM-based method. Through experiment with real measurement, the proposed method's recognition performance is reported.

  • PDF

인터넷 의류쇼핑에서 온라인 구전정보특성 중 방향성과 동의성이 소비자 구매행동 변화에 미치는 영향 (The Effects of Information Characteristics(Direction, Consensus) on Word-of-Mouth Performance in Online Apparel Shopping)

  • 손진아;이은영
    • 한국의류학회지
    • /
    • 제31권8호
    • /
    • pp.1157-1167
    • /
    • 2007
  • Internet communications have provoked new forms of online word-of-mouth(WOM) communication and it has become more powerful. At this point, this study analyses the effects of information characteristics(direction, consensus) of online WOM. Especially, quasi-experiment can systematically manipulate the direction and the consensus of online WOM information and it perceived the difference in the effects in this study. Female consumers who have purchased clothing at online shopping mall in past 6 months participated in the experiment by completing 4 type questionnaires(N=600). Data are analyzed using Cronbach's ${\alpha}$, t-test, one way ANOVA, two-way ANOVA, Duncan's multiple range test. The Results of this study are as follows: (1) The direction of online WOM information significantly influences consumer's reliability of information, attitude, and purchase intentions. These effects are more significant when negative WOM information than positive information and two-sided information was given. (2) Though there is the difference in reliability of information, the consensus of online WOM information does not have influences on consumer's attitude and purchase intentions. (3) Consumer's clothing involvement is related to WOM information searching. The highly involved consumer is more effected by online WOM information than the lowly one.

정보기술단원 평가에서 분석적 루브릭의 적용이 학습자의 자기주도 학습력에 미치는 영향 (Effects of Analytic Rubrics on Learners' Self-Directed Learning Ability in Information Technology Unit Assessment)

  • 남승권;최완식
    • 대한공업교육학회지
    • /
    • 제30권1호
    • /
    • pp.56-67
    • /
    • 2005
  • The purpose of this study was to examine the effects of analytic rubrics on learners' self-directed learning ability in information technology unit assessment. The experiment and control groups were 4 classes of the 2nd grade in B middle school located in Daejeon. The pretest was performed to check the group homogeneity. For the experiment design, the nonequivalent control group design as a type of quasi-experimental design was used. The experiment was composed of 5 sessions. Statistical significance was p < .05 to verify the hypothesis, and SPSS 12.0 for Windows was used for statistical treatment. The results from this study were as follows: (1) The application of analytic rubrics in information technology unit assessment affected learners' self-directed learning ability in a positive way in 4 factor's(openness, self-concept, intrinsic motivation, self-evaluation) but does not affected in 3 factor's(autonomy, creativity, problem solving). (2) The difference in sex was not a statistically significant factor in the application of analytic rubrics in information technology unit assessment. Based on the results of the experiment, two suggestions were made to promote the application of rubrics in technology education assessment. (1) Research and development of many types of rubrics for technology education are needed. (2) Systematic training of rubrics for technology teachers is needed.

약물 및 증상관리에 대한 자가간호교육이 정신질환자의 삶의 질에 미치는 효과 (Effectiveness of the Self-care Education for the Medication and Symptoms Management on the Psychiatric Patients' Quality of life)

  • 손경희
    • 한국간호교육학회지
    • /
    • 제5권2호
    • /
    • pp.300-314
    • /
    • 1999
  • This study is an attempt to evaluate the effect of the medication and symptoms self-care education on the psychiatric patients' quality of life. This exploratory study was designed to a quasi-experiment of pretest-postest with a non equivalent control group. Subjects of 40 patients who were discharged from a mental hospital in Pusan were selected to be experiment and control group, with each group consisting of 20. The research period was from March, 6 to May, 29, 1999 and the pre-post test was given before and after implementing MSSE to the both experiment and control group. The results finding were summarized as follows ; 1. subjects who attended self-care education scored significantly higher than control group in quality of life.(Z=-2.06, P=0.034) 2. Those who were in the experiment group reported more significant higher scores than control group in item of quality of life, living situation(A=-2.62 P=0.012), relations with spouse (Z=-2.31 P=0.038) and children (Z=3.37, P=0.008), fear (Z=-1 95, P=0.049) and anger(Z=-2.07 P=0.041), work functioning (Z=-2.34, P=0.021), environmental adjustment. (Z=-2.05, P=0.039)

  • PDF

Evaluating the Mechanical Properties of Fiber Yarns for Developing Synthetic Fiber Chains

  • Kim, Kyeongsoo;Kim, Taewan;Kim, Namhun;Kim, Dokyoun;Kang, Yongjun;Kim, Seonjin
    • 한국해양공학회지
    • /
    • 제35권6호
    • /
    • pp.426-433
    • /
    • 2021
  • In this study, three types of synthetic fiber materials were evaluated, namely, DM20, SK78, and T147, to replace steel chains in shipbuilding and offshore fields with fiber chains as there is increasing demand for chains with lighter weights and improved usabilities. The strength and quasi-static stiffness were analyzed to select suitable yarns for the fiber chains. The durability of the yarn was evaluated by performing a 3-T (time to rupture) test as a specific tension level. The results of the experiment revealed excellent dynamic stiffness in DM20 and highest values of the windward and leeward stiffness in T147. 3-T linear design characteristic curves for a specific tension level were derived for the three types of fiber materials. The findings of this study can provide insights for improving strength and durability in fiber chain design.