3,678 research outputs found
Noncircular rolling joints for vibrational reduction in slewing maneuvers
A rolling joint is provided for obtaining slewing maneuvers for various apparatus including space structures, space vehicles, robotic manipulators, and simulators. Two noncircular cylinders, namely a drive and a driven cylinder, are provided in driving contact with one another. This contact is maintained by two pairs of generally S-shaped bands, each pair forming a generally 8-shaped coupling tightly about the circumferential periphery of the noncircular drive and driven cylinders. A stationarily fixed arm extends between and is rotatably journalled with a drive axle and a spindle axle respectively extending through selected rotational points of the drive cylinder and of the driven cylinder. The noncircular cylinders are profiled to obtain the desired varying gear ratio. The novelty of the present invention resides in using specifically profiled noncircular cylinders to obtain a desired varying gear ratio
High cycle fatigue and ratcheting interaction of laser powder bed fusion stainless steel 316L:Fracture behaviour and stress-based modelling
Variations in the physical and mechanical properties of parts made by laser power bed fusion (L-PBF) could be affected by the choice of processing or post-processing strategies. This work examined the influence of build orientation and post-processing treatments (annealing or hot isostatic pressing) on the fatigue and fracture behaviours of L-PBF stainless steel 316L in the high cycle fatigue region, i.e. 104 – 106 cycles. Experimental results show that both factors introduce significant changes in the plastic deformation properties, which affect fatigue strength via the mechanism of fatigue-ratcheting interaction. Cyclic plasticity is characterised by hardening, which promotes mean stress insensitivity and improved fatigue resistance. Fatigue activities, involving the initiation of crack at defects and microstructural heterogeneities, are of greater relevance to the longer life region where the global deformation mode is elastic. As the simultaneous actions of ratcheting and fatigue generate complex nonlinear interactions between the alternating stress amplitude and mean stress, the fatigue properties could not be effectively predicted using traditional stress-based models. A modification to the Goodman relation was proposed to account for the added effects of cyclic plasticity and was demonstrated to produce good agreement with experimental results for both cyclic hardening and softening materials.EDB (Economic Devt. Board, S’pore)Accepted versio
The Catalyzing Factors of Official Documents Exchange via Microblogging in Public Sectors: A Case Study based on the T-O-E Framework
Since Government transparency and information open has got more attention by both academia and practitioners with the development of information technologies (IT) and Internet, The popularity of Web 2.0 application provides the government some new opportunities and challenges. Official documents exchange via microblogging (ODEM) in the Bureau of Justice, Haining is a practice case of government information open in the new media. For analyzing the determinants from academic perspective and exploring the managerial value of the case, the paper report an exploratory case study based on the technology-organization-environment (TOE) framework. After several field interviews and rigorous data coding by following the case study methodology, we find that top manager’s support, personnel’s IT accomplishment, and regional economic and social environment are the key determinants of the emergence of ODEM, as well as the organizational structure and operational flow is not change immediately in this case. The limitation and future goals of the study are also discussed in the paper
UNDERSTANDING THE IMPACT OF INTERNET MEDIA ON PATIENT-CLINICIAN TRUST: MODEL DEVELOPMENT AND RESEARCH DESIGN
Patient-clinician trust is one of the major concerns regarding the relationship between the public and the healthcare industry. The development of Internet technology, especially Web 2.0 applications, provides us with a greater ability to exchange information and provide feedback. To describe and measure the impact of ICT-based new media on patient-clinician trust, this paper develops a theoretical model that builds on previous literature in both the healthcare and IS research areas. The paper also aims to explain the differing impacts of online reports (Web 1.0) and online comments (Web 2.0), along with the differing impacts of positive and negative comments. Expected contributions and an agenda for future empirical experiment are also discussed in the paper
Exploring Different Roles between Service Expectation and Technology Expectation In Citizen’s E-Government Continuance Adoption: An Extended Expectation-Confirmation Model
Although Chinese government has got remarkable achievement in e-Government development, the difficult issue that citizen use behaviour cannot last toward many e-Government services has long been troubling to government in different levels. Based on expectation-confirmation theory (ECT), this paper proposed an extended model by divide the expectation and perceived performance into two categories, service perspective and technology perspective, for understanding the different roles of those factors in the process of e-Government continuance adoption. The research plan of an empirical experiment toward the e-Government portal of Beijing, the capital of China for utilizing this extended model was also discussed briefly in the paper
Understanding Cross-Sector Collaboration in E-Government Development: Theoretical Consideration Based on Extended Bryson’s Framework
With the rapid development of e-government, cross-sector collaboration has been one of the most important issues to academia and practitioners. Although collaboration was a classical topic in public administration research, digital age and e-government environment complicate the related issues from multi-perspectives. Based on accumulated literature in the public administration research area and e-government research area, this paper tries to introduce Bryson’s Framework, an important theoretical framework of collaboration in public administration provided on 2006, for analyzing cross-sector collaboration based on e-government development more deeply. Considering the e-government environment, we redefine and extend the detail items of five basic dimensions in the framework, called initial conditions, process, structure and governance, constraints on collaboration, outcomes. The research plan of an empirical study in a local government in China for utilizing this extended framework was also discussed briefly in the paper
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