• 제목/요약/키워드: Cross-Impact

검색결과 973건 처리시간 0.024초

Assessment of dynamic crushing and energy absorption characteristics of thin-walled cylinders due to axial and oblique impact load

  • Baaskaran, N.;Ponappa, K.;Shankar, S.
    • Steel and Composite Structures
    • /
    • 제28권2호
    • /
    • pp.179-194
    • /
    • 2018
  • Reliable and accurate method of computationally aided design processes of advanced thin walled structures in automotive industries are much essential for the efficient usage of smart materials, that possess higher energy absorption in dynamic compression loading. In this paper, most versatile components i.e., thin walled crash tubes with different geometrical profiles are introduced in view of mitigating the impact of varying cross section in crash behavior and energy absorption characteristics. Apart from the geometrical parameters such as length, diameter and thickness, the non-dimensionalized parameters of average forces which control the plastic bending moment for varying thickness has explored in view of quantifying its impact on the crashworthiness of the structure. The explicit finite element code ABAQUS is utilized to conduct the numerical studies to examine the effect of parametric modifications in crash behavior and energy absorption. Also the simulation results are experimentally validated. It is evident that the circular cross-sectional tubes are preferable as high collision impact shock absorbers due to their ability in withstanding axial and oblique impact loads effectively. Furthermore, the specific energy absorption (SEA), crash force efficiency (CFE), plastic bending moment, peak force responses and its impact for optimally tailoring a design to cater the crashworthiness requirements are investigated. The primary outcome of the study is to provide sufficient information on circular tubes for the use of energy absorbers where impact oblique loading is expected.

기술상호효과분석의 입력변수 추정 난이도 경감을 위한 입력변수 설정모형의 설계 (Designing an Input Parameters Setting Model for Reducing the Difficulty of Input Parameters Estimations in Cross Impact Analysis)

  • 전정철;권철신
    • 한국경영과학회지
    • /
    • 제42권2호
    • /
    • pp.35-48
    • /
    • 2017
  • As the technology convergence paradigm emerges, the need for "CIA techniques" to analyze the mutual effects of technology is increasing. However, since the CIA input parameter estimation is difficult, the present study suggests a "CIA input parameter setting model" to alleviate the difficulty of CIA input parameter estimation. This paper is focused on the difference of measurement difficulty by each scale which expert's estimation behavior was defined as measurement activity quantifying the judgment of future technology. Therefore, this model is designed to estimate the input variable as a sequence or isometric scale that is relatively easy to measure, and then converts it into a probability value. The input parameter setting model of the CIA technique consists of three sub-models : 'probability value derivation model', 'influence estimation model', and 'impact value calculation model', in order to develop a series of models the Thurstone V model, Regression Analysis, etc has been used.

한국과 미국 대학생의 패션 브랜드 충성도 영향 요인에 관한 비교 문화 연구 - 쇼핑 성향, 의류 제품 속성 평가, 의복 추구 혜택을 중심으로 - (A Cross-Cultural Study on the Factors Influencing on Fashion Brand Loyalty between Korean and American College Students - Focused on Shopping Orientations, Clothing Attributes Evaluation, Clothing Benefits Sought -)

  • 박현희;구양숙
    • 복식문화연구
    • /
    • 제16권5호
    • /
    • pp.910-923
    • /
    • 2008
  • This study investigated the difference in the influence of shopping orientations, attributes evaluation, and benefits sought on brand loyalty between Korean and American consumers within a clothing purchase context. Questionnaires were administered to 237 Korean consumers and 184 American college students who had purchase experience of casual wear in recent six months through off-line. The results were as follows. First, the hedonic shopping orientation had a positive impact on brand loyalty in both groups, whereas efficient shopping orientation had a positive impact on brand loyalty in American group. Second, the aesthetic attribute had a positive impact on brand loyalty in both groups, whereas utilitarian attribute had a positive impact on brand loyalty in Korean group. Third, brand value benefit sought had a positive impact on brand loyalty in Korean group and body expression/complement had a positive impact on brand loyalty and economic benefit sought had a negative impact on brand loyalty in American group.

  • PDF

탄소 섬유강화 복합재료의 중력 낙하 충격으로 인한 손상 평가 (Drop-weight impact damage evaluation for carbon fiber/epoxy composite laminates)

  • Sohn, Min-Seok;Hu, Xiao-Xhi;Ki, Jang-Kyo;Hong, Soon-Hyung
    • 한국복합재료학회:학술대회논문집
    • /
    • 한국복합재료학회 2001년도 춘계학술발표대회 논문집
    • /
    • pp.89-92
    • /
    • 2001
  • Drop weight impact tests were performed to investigate the impact behavior of carbon fiber/epoxy composite laminates reinforced by short fibers and other interleaving materials. Characterization techniques, such as cross-sectional fractography and scanning acoustic microscopy, were employed quantitatively to assess the internal damage of some composite laminates. Scanning electron microscopy was used to observe impact damage and fracture modes on specimen fracture surfaces. The results show that composite laminates experience various types of fracture; delamination, intra-ply cracking, matrix cracking and fiber breakage depending on the interlayer materials. Among the composite laminates tested in this study, the composites reinforced by Zylon fibers showed very good impact damage resistance with medium level of damage, while the composites interleaved by poly(ethylene-co-acrylic acid) (PEEA) film is expected to deteriorate the bulk strength due to the reduction of fiber volume fraction, even though the damaged area is significantly reduced.

  • PDF

The Influence Factors of China's Cross-border E-commerce Export Trade Using Gravity Model

  • Jing Han;Taehee Lee
    • Journal of Korea Trade
    • /
    • 제26권5호
    • /
    • pp.56-75
    • /
    • 2022
  • Purpose - This study examines the influencing factors of China's cross-border e-commerce exports in the context of the current situation and trends of China's cross-border e-commerce development. Through an improved trade gravity model, it provides more in-depth research and constructive opinions on the development of cross-border e-commerce in China. In this paper, factors such as consumption gap, volume of trade frictions, number of tourists, Internet usage and trade openness are added to the formula of the traditional trade gravity model in the improved trade gravity model to examine the influencing factors on China's cross-border e-commerce exports. Design/methodology - According to the empirical analysis, China's cross-border e-commerce exports to ten countries are used as dependent variables, and consumption gap, trade friction volume, trade distance, trade openness and number of Internet users are taken as independent variables. Regression analysis is conducted through a modified gravity model to test whether the hypotheses hold. Findings - The analysis shows that the hypothesis that China's cross-border e-commerce exports are influenced by trade openness, trade distance, consumption gap between trade parties, and the number of Internet users in the importing country is supported by these four hypotheses, but not all independent variables have an impact on them. Specifically, the number of travelers, trade frictions do not have an impact on China's cross-border e-commerce. That is to say, trade friction between China and the United States and political issues such as China-India and China-Japan territorial disputes that emerged before do not affect the development of cross-border e-commerce in China. Originality/value - The analysis shows that the factors influencing China's cross-border e-commerce exports are the trade openness of the importing country, the trade distance, the number of Internet users in the importing country, and the consumption gap between the two sides of the trade. The trade openness and the number of Internet users positively contribute to China's cross-border e-commerce, while the consumption gap and trade distance are negatively related to them. And the analysis found that the Sino-US trade war and the Sino-Indian territorial disputes and other trade frictions to China's cross-border e-commerce exports did not have a substantial impact.

상호영향형 R&D과제군의 평가산정을 위한 "CIDEAR" 모형의 개발 (Construction of "CIDEAR" Model for Selecting and Evaluating Cross Impact R & D Projects)

  • 권철신;박준호;홍석기
    • 한국경영과학회지
    • /
    • 제29권3호
    • /
    • pp.41-61
    • /
    • 2004
  • The purpose of this paper is to construct $\ulcorner$CIDEAR(Cross Impact-DEA-AR)$\lrcorner$ model which evaluates proposed R&D projects considering cross impact among them and selects proper projects to utilize resources efficiently as well as to maximize efficacy of investments. For this purpose, $\ulcorner$CIDEAR$\lrcorner$ model is designed as the following six steps. $\ulcorner$Decision Theory Evaluation Model$\lrcorner$ is for setting and selecting the evaluation items according to the structured procedure of evaluation system. The priority of items is decided at $\ulcorner$AR Decision Model$\lrcorner$$\ulcorner$Cross Impact Estimation Model$\lrcorner$ is for computing the final probability of success and the result is used to revise the evaluation results of $\ulcorner$Decision Theory Evaluation Model$\lrcorner$. $\ulcorner$Resource Performance Analysis Model$\lrcorner$ classifies the proposed R&D projects on the basis of required resources and expected performance. Consequently, the possibility of bias of project selection can be prevented. $\ulcorner$Priority Oder Decision Model$\lrcorner$ is for computing the efficacy of proposed projects. Finally, $\ulcorner$Efficacy-Efficiency Cause Analysis Model$\lrcorner$ analyzes the structure of efficacy and efficiency of the projects. The major findings and significances of this study are summarized as follows: (1) $\ulcorner$CIDEAR$\lrcorner$ model can deal with the affairs of R&D projects having the characteristics of mutual independence as well as mutual dependence in the point of efficacy and efficiency. Hence, it is possible to evaluate and select R&D projects more accurately. (2) It can be possible to raise the possibility of projects success. R&D manager can use the information for project management because the efficacy-efficiency structure of selected projects can be analyzed. (3) We proved the usefulness of the constructed $\ulcorner$CIDEAR$\lrcorner$ model using an case about twenty-one R&D projects of a leading company of electronic industry in Korea.

A Longitudinal Study on Adolescent's Multicultural Acceptability and School Adjustment using Autoregressive cross-lagged model

  • Kim, Hyun-Joo;Park, Hwie-Seo
    • 한국컴퓨터정보학회논문지
    • /
    • 제24권7호
    • /
    • pp.153-160
    • /
    • 2019
  • This study aims to analyze the mutual influences between adolescents' multicultural acceptability and school adjustment. Research problems for research are as follows. First, is multicultural acceptability and school adjustment stable over time? Second, what is the longitudinal impact of school adjustment on multicultural acceptability over time? Third, what is the longitudinal impact of multicultural acceptability on school adjustment over time? The results of analyzing the research problems by applying the autoregressive cross-lagged model are as follows. First, the autoregressive model of school adjustment has a significant effect on the future time point and is stable over time. Second, the autoregressive model of multicultural acceptability have a significant effect on the future time point and is stable over time. Third, cross-lagged effect from school adjustment to multicultural acceptability has a statistically significant effect on the multicultural acceptability at a later time, and is stable over time. Fourth, cross-lagged effect from multicultural acceptability to school adjustment was not statistically significant at the time of multicultural acceptability, and there was no change with time. This study is meaningful to provide the theoretical and practical implications by verifying the influence of the three - year term data over time.

고유변동성, 조건부 유동성, 그리고 주식수익률의 횡단면에 관한 연구 (Idiosyncratic Volatility, Conditional Liquidity, and Cross-section of Stock Returns in Korea)

  • 윤상용;조성순;박순홍
    • 아태비즈니스연구
    • /
    • 제12권1호
    • /
    • pp.121-134
    • /
    • 2021
  • Purpose - This study examines whether flight-to-liquidity (FTL) explains the dynamic liquidity risk on stock returns, and whether it has a significant influence on determinants the cross-section of stock returns. Design/methodology/approach - This study suggests a new risk factor, dynamic liquidity hedge portfolio (DLP), to reflect the dynamic impact of liquidity risk on stock returns and the Fama-MacBeth 2 stage regression analysis is employed in order to analyze the data. Findings - First, the DLP factor shows more positive and significant beta for the small or illiquidity stocks. Second, the DLP shows a different influence than SMB (size risk factor), HML (value risk factor), NMP (liquidity risk factor), FTVOL (total volatility factor) in determining the cross-section of stock returns. In addition, the DLP has a statistically significant risk premium of around 5%, which is relatively larger than other risk factors. Research implications or Originality - This study has academic value in terms of newly confirming that the DLP factor has a more significant impact on cross-sectional determination of stock returns than other risk factors by proposing a conditional liquidity factor that can explain the FTL phenomenon.

Effect of Impact Energy on the Impact-Wear Properties of High Manganese Steels in Acidic Corrosive Conditions

  • Wang, Kai;Du, Xiao-Dong;Wu, Kai;Youn, Kuk-Tae;Lee, Chan Gyu;Koo, Bon Heun
    • Corrosion Science and Technology
    • /
    • 제7권6호
    • /
    • pp.362-369
    • /
    • 2008
  • The impact abrasion behavior of high manganese steel is investigated under three kinds of impact energy in acid hematite ore slurry by using a modified MLD-10 impact abrasion tester. Through the SEM observation of the worn surface and the optical metallographic analysis of the cross-sectional samples, the corrosive impact abrasion mechanisms of the steel under different impact energies are studied. In acid-hematite slurry, the variations of impact energies would result in synchronous transformation of the impact abrasion properties and mechanisms of the high manganese steel in the corrosive condition, as led different corrosive impact abrasion mechanism under different impact energies.

상호영향형 R&D과제군의 평가선정을 위한 새로운 $\lceilDEA\rfloor$ 모형의 개발

  • 권철신;박준호;홍석기
    • 한국경영과학회:학술대회논문집
    • /
    • 한국경영과학회/대한산업공학회 2003년도 춘계공동학술대회
    • /
    • pp.980-983
    • /
    • 2003
  • The purpose of this paper is to construct a CIDEAR (Cross Impact Data Envelopment Analysis Assurance Region) model which evaluates proposed R&D projects considering cross impacts among them and selects them to utilize R&D resources effectively as well as to maximize effectiveness of investments. For this purpose, the following six steps are designed as the main procedure. $\lceilDecision\;Theory\;&\;Evaluation\;Model\rfloor$, $\lceilAR\;Decision\;&\;Evaluation\;Model\rfloor$, $\lceilResource\;&\;Performance\;Analysis Model\rfloor$, $\lceilCross\;Impact\;Assumption\;Model\rfloor$, $\lceilpriority\;Oder\;Decision\;Model\rfloor$, $\lceilEfficiency\;Cause\;Analysis\;Model\rfloor$. $\lceilCIDEAR\rfloor$ model can deal with the affairs of R&D projects having the characteristics of mutual independence as well as mutual dependence. Hence it is possible to evaluate and select R&D projects more accurately than any other models.

  • PDF