The impact of a wideband channel on UWB system design

Author(s):  
M.S.W. Chen ◽  
R.W. Brodersen
2021 ◽  
pp. 147715352098742
Author(s):  
FŞ Yilmaz

Office buildings are building typologies where efficient and optimal use of lighting energy is crucial while providing comfortable visual environments. The purpose of this study is to explore the impact of diverse architectural design alternatives on lighting energy requirements and lighting energy saving possibilities through a case study. In this study, a total of 3888 design alternatives are investigated in a comparative way in terms of daylighting system design alternatives, artificial lighting system design scenarios, artificial lighting system control types and shading system control options. Introducing the adaptation process of the EN 15193-1:2017 standard for Turkey’s specific climatic and geographical conditions and considering diverse lighting design scenarios, results of this parametric study aim to underline the significance of architectural design strategies in office buildings for the reduction of lighting energy requirements.


2019 ◽  
Vol 30 (3) ◽  
pp. 309-328 ◽  
Author(s):  
Mariella Bastian ◽  
Mykola Makhortykh ◽  
Tom Dobber

PurposeThe purpose of this paper is to develop a conceptual framework for assessing what are the possibilities and pitfalls of using algorithmic systems of news personalization – i.e. the tailoring of individualized news feeds based on users’ information preferences – for constructive conflict coverage in the context of peace journalism, a journalistic paradigm calling for more diversified and creative war reporting.Design/methodology/approachThe paper provides a critical review of existing research on peace journalism and algorithmic news personalization, and analyzes the intersections between the two concepts. Specifically, it identifies recurring pitfalls of peace journalism based on empirical research on constructive conflict coverage and then introduces a conceptual framework for analyzing to what degree these pitfalls can be mediated – or worsened – through algorithmic system design.FindingsThe findings suggest that AI-driven distribution technologies can facilitate constructive war reporting, in particular by countering the effects of journalists’ self-censorship and by diversifying conflict coverage. The implementation of these goals, however, depends on multiple system design solutions, thus resonating with current calls for more responsible and value-sensitive algorithmic design in the domain of news media. Additionally, our observations emphasize the importance of developing new algorithmic literacies among journalists both to realize the positive potential of AI for promoting peace and to increase the awareness of possible negative impacts of new systems of content distribution.Originality/valueThe article particle is the first to provide a comprehensive conceptualization of the impact of new content distribution techniques on constructive conflict coverage in the context of peace journalism. It also offers a novel conceptual framing for assessing the impact of algorithmic news personalization on reporting traumatic and polarizing events, such as wars and violence.


2021 ◽  
Author(s):  
Ning He ◽  
Hu Yang ◽  
Fanli Xu ◽  
Yongming Cheng

Abstract A riser is a key component for transporting produced oil and gas from the subsea wells to the surface production vessel. Through nearly 30 years of design and implementation, Steel Catenary Risers (SCRs) have been found to have the advantages of relatively low cost and good adaptability to floating platform’s motion. This paper investigates deepwater SCR system design for the Lingshui 17-2 (termed LS17-2) project. This paper first introduces a SCR system for the LS17-2 project. The field for this project is located in the northern South China Sea, with water depth of 1220m to 1560m. LS17-2 consists of a subsea production system, a deep-draft semi-submersible (SEMI), and an export riser/pipeline. The platform was designed to have a large storage capacity with a variable draft during its operation. Based on deepwater SCR engineering experience, the key SCR design challenges are summarized from the engineering executive perspective. The challenges to the SCR system design for the LS17-2 project include harsh environment condition in South China Sea and the impact on fatigue design for the requirement of 30-years’ service life. They call for design optimization and innovative ideas. The engineering design and analysis are discussed together solutions. To demonstrate the deepwater SCR system design for LS17-2 project, examples are provided to illustrate the challenges and solutions. The experience learned from this paper should have significant relevance to future SCR design.


IEEE Access ◽  
2017 ◽  
Vol 5 ◽  
pp. 781-793 ◽  
Author(s):  
Jinxing li ◽  
Youping Zhao ◽  
Cheng Tao ◽  
Bo Ai

Author(s):  
Alan Yu ◽  
Paul Stanton ◽  
Yongming Cheng

Top tensioned risers are fluid conduits from subsea equipment to surface floating production platforms. The advantages of using top tensioned risers are the ability to drill and complete through the production riser, ease of access of the production trees for gas lift operation, and the simplicity of workover and redrill. The integrity of a riser system plays an important role in deepwater developments. Top tensioned risers (TTRs) and steel catenary risers (SCRs) have been widely used with floating production systems such as Spars and TLPs. API RP 2RD [1] has been used to guide riser system design for the last decade. API RP 2RD is being revised as a code (ISO 13628-12) that will also be adopted as a new API code. This paper investigates the impacts of the new design code on the riser system design. This paper first discusses the differences between ISO/WD 13628-12 and the existing API RP 2RD code, particularly the section on design criteria for pipes. The Holstein top tensioned riser system is chosen as an example to evaluate the riser system design impacts. The risers have been installed and successfully producing oil since 2005. The results of the nonlinear finite element program ABAQUS used to analyze the Holstein top tensioned risers were evaluated according to the API RP 2RD. The same analytical results are used for evaluating the impact of the proposed ISO 13628-12 in the area of stress evaluation.


Author(s):  
Diana G. San Benito Pastor ◽  
Devaiah Nalianda ◽  
Vishal Sethi ◽  
Ron Midgley ◽  
Andrew Rolt ◽  
...  

Abstract This study introduces an innovative approach to sizing a differential planetary gearbox for a counter-rotating open rotor application. An updated methodology is proposed for the design of maximum load capacity gears based on the power transmitted, durability and space-envelope requirements of the application. The reported methodology has been validated by comparing the results to published data, demonstrating a maximum difference of 0.6% in geometry. Parametric analyses have also been performed to assess the impact of the design assumptions on gearbox dimensional trends. The proposed methodology enables the assessment of the impact of the preliminary transmission system design on engine performance and general arrangement. The characteristics of the gearset lead to an unequal torque split between output shafts (i.e. the propeller shafts). Given the design assumptions made, the study indicates that valid torque ratios would lie between 1.1 and 1.33. The impact of the torque ratio on the size of the gearbox has been analysed for equal rotational speeds and for different speeds between the output shafts. The study established that the transmission system design needs to be considered prior to selection of the torque ratio at engine design level.


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