1,720,996 research outputs found
Behavior of RHS X-joints having high brace to chord width ratio under axial compression
No full textIn this study, the behavior of Rectangular Hollow Section (RHS) X-joints having a brace to chord width ratio (BCWR) higher than 0.85, or the behavior as affected by the chord sidewall buckling was investigated experimentally and analytically. The experimental program tested a total of six full-scale RHS X-joints fabricated from both ordinary and high strength steel under axial compression. All high strength steel specimens with a measured yield stress as high as 700 MPa exceeded the Eurocode nominal strength with sufficient margin. Significantly different joint behavior was observed depending upon BCWR; the joints with high BCWR exceeding 0.85 was very brittle or they initially showed very stiff, almost elastic behavior and buckled with subsequent rapid strength degradation irrespective of steel grades. According to the test results, brittle behavior of RHS X-joints as affected by the chord sidewall buckling seemed probable at a BCWR less than 0.85. The sidewall buckling strength in Eurocode was again shown to be very conservative, more for high strength steel joints. A new strength formula for RHS X-joints prone to chord sidewall buckling was proposed. The effect of chord stress was also numerically investigated based on test-validated FE nonlinear analysis.N
Carbon emissions and search for renewable energy technology: ICT firms' environmental corporate social responsibility
No full textMotivation on search for renewable energy technology: ICT firms' environmental CSR
No full textThe literature in sustainability has emphasized external pressures as a main driver of firms’ environmental responsibility. However, under similar external pressures, some firms search for environmental technology, while others do not. By focusing on information and communication technology (ICT) firms, we try to answer the question of when firms are motivated to search for renewable energy technology. Drawing on the framework of the behavioral theory of the firm, we propose that a mismatch between ICT firms’ CO2 emissions performance and their aspiration to a certain level of emissions induce firms to evaluate their environmental performance status—whether they are aligned well with environmental requirements and their peer firms—and their technology status—whether they possess sufficient technologies to reduce emissions—which in turn affects their search for renewable energy technology. We corroborate our hypotheses using data on CO2 emissions and renewable energy patents of U.S. ICT firms from 2010 to 2018. When we compare two groups of firms—one group whose emissions performance is poor and the other group whose emissions performance is good compared to their own past emissions—we find that the former is more likely to search for renewable energy technology compared to the latter. When we focus on each of the two groups, we find that firms decrease their search for renewable energy technology as the degree of poor emissions performance exacerbates (firms’ emissions increase above aspiration) or the degree of good emissions performance increases (firms’ emissions decrease below aspiration). Our findings have implications for public policy as well as firms’ environmentally sustainable operations
ICT firm CO2 emissions and search for renewable energy technology: Motivation to environmental CSR
No full textThe literature in sustainability has emphasized external pressures as a main driver of firms’ environmental responsibility. However, under similar external pressures, some firms search for environmental technology, while others do not. By focusing on information and communication technology (ICT) firms, we try to answer the question of when firms are motivated to search for renewable energy technology. Drawing on the framework of the behavioral theory of the firm, we propose that a mismatch between ICT firms’ CO2 emissions performance and their aspiration to a certain level of emissions induce firms to evaluate their environmental performance status—whether they are aligned well with environmental requirements and their peer firms—and their technology status—whether they possess sufficient technologies to reduce emissions—which in turn affects their search for renewable energy technology. We corroborate our hypotheses using data on CO2 emissions and renewable energy patents of U.S. ICT firms from 2010 to 2018. When we compare two groups of firms—one group whose emissions performance is poor and the other group whose emissions performance is good compared to their own past emissions—we find that the former is more likely to search for renewable energy technology compared to the latter. When we focus on each of the two groups, we find that firms decrease their search for renewable energy technology as the degree of poor emissions performance exacerbates (firms’ emissions increase above aspiration) or the degree of good emissions performance increases (firms’ emissions decrease below aspiration). Our findings have implications for public policy as well as firms’ environmentally sustainable operations
ICT firm CO2 emissions and search for renewable energy technology: Motivation to environmental CSR
No full textThe literature in sustainability has emphasized external pressures as a main driver of firms’ environmental responsibility. However, under similar external pressures, some firms search for environmental technology, while others do not. By focusing on information and communication technology (ICT) firms, we try to answer the question of when firms are motivated to search for renewable energy technology. Drawing on the framework of the behavioral theory of the firm, we propose that a mismatch between ICT firms’ CO2 emissions performance and their aspiration to a certain level of emissions induce firms to evaluate their environmental performance status—whether they are aligned well with environmental requirements and their peer firms—and their technology status—whether they possess sufficient technologies to reduce emissions—which in turn affects their search for renewable energy technology. We corroborate our hypotheses using data on CO2 emissions and renewable energy patents of U.S. ICT firms from 2010 to 2018. When we compare two groups of firms—one group whose emissions performance is poor and the other group whose emissions performance is good compared to their own past emissions—we find that the former is more likely to search for renewable energy technology compared to the latter. When we focus on each of the two groups, we find that firms decrease their search for renewable energy technology as the degree of poor emissions performance exacerbates (firms’ emissions increase above aspiration) or the degree of good emissions performance increases (firms’ emissions decrease below aspiration). Our findings have implications for public policy as well as firms’ environmentally sustainable operations
A Behavioral perspective on environmental technology search: Evidence from non-energy-intensive firm
No full textThe literature in sustainability has emphasized external pressures as a main driver of firms’ environmental responsibility. However, under similar external pressures, some firms search for environmental technology, while others do not. By focusing on information and communication technology (ICT) firms, we try to answer the question of when firms are motivated to search for renewable energy technology. Drawing on the framework of the behavioral theory of the firm, we propose that a mismatch between ICT firms’ CO2 emissions performance and their aspiration to a certain level of emissions induce firms to evaluate their environmental performance status—whether they are aligned well with environmental requirements and their peer firms—and their technology status—whether they possess sufficient technologies to reduce emissions—which in turn affects their search for renewable energy technology. We corroborate our hypotheses using data on CO2 emissions and renewable energy patents of U.S. ICT firms from 2010 to 2018. When we compare two groups of firms—one group whose emissions performance is poor and the other group whose emissions performance is good compared to their own past emissions—we find that the former is more likely to search for renewable energy technology compared to the latter. When we focus on each of the two groups, we find that firms decrease their search for renewable energy technology as the degree of poor emissions performance exacerbates (firms’ emissions increase above aspiration) or the degree of good emissions performance increases (firms’ emissions decrease below aspiration). Our findings have implications for public policy as well as firms’ environmentally sustainable operation
Re-evaluation of Force Transfer Mechanism of Welded Steel Moment Connections
Full text link용접 철골 모멘트접합부는 일반적으로 평면유지의 가정을 전제한 초등휨이론에 의해 설계되어 왔다. 그러나 1994년 노스리지 지진 이후 보-기둥 접ㅈ합부의 설계에 초등휨이론으르 적용하는 것은 타당치 않음이 몇몇 연구자에 의해 제기된 바가 있다. 본 연구에서는 필자의 최근 해석 및 실험연구를 주 근거로 하여 다양한 형식의 접합부의 응력전달 메커니즘을 재평가하고 거의 모든 용접 모멘트접합부의 설계에 초등휨이론을 적용하는 것이 부적절함을 보이고자 하였다. 보의 웨브, 수평헌지의 웨브, 리브 등과 같은 수직 플레이트 접합요소는 모두 스트럿 작용에 의해 응력을 전달하는 유사성이 있음을 해석적, 실험적으로 확인하였다. 또한 최근 가장 큰 주목을 받고 있는 고연성 RBS 접합부의 전단력 응력전달 메커니즘은 PN형식 접합부의 그것과 크게 다르지 않음을 확인하였다. 아울러 접합부 설계에 유용하게 활용될 수 있는 단순화된 해석적 응력전달 모형을 소개하였다.; Employing the classical beam theory for the design of welded steel moment connections has been brought into question by several researchers since the 1994 Northridge earthquake. In this study, the load transfer mechanism in various welded steel moment connections is comprehensively reviewed mainly based on recent studies conducted by the writer. Available analytical and experimental results showed that the load path in almost all the welded steel moment connections is completely different from that as predicted by the classical beam theory. Vertical plates near the connection such as the beam web, the web of the straight haunch, and the rib act as a strut rather than following the classical beam theory. The shear force transfer in the RBS connection is essentially the same as that in PN type connection. Some simplified analytical models that can be used as the basis of a practical design procedure are also presented.본 연구를 위한 2003년도 서울대학교 신임교수 연구정착금 지원에 감사드립니다
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
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