24,635 research outputs found
Modelling and control of a variable-speed switched reluctance generator based wind turbine
No full textThis paper studies the system modelling and control aspects of switched reluctance generator (SRG) based variable speed wind turbines. A control system is implemented to provide proper operation of the SRG as well as power tracking capabilities for varying wind speeds. The control system for the grid side inverter that will allow the SRG to properly generate power to the system is also presented. Studies are presented of both the SRG and inverter control systems capabilities during a balanced three-phase fault. The paper will demonstrate that the SRG based wind turbine presents a feasible variable wind speed solution with good fault response capabilities
Automating the determination of wave speed using the pu-loop method
No full textThe PU-loop (pressure-velocity loop) is a method for determining wave speed and relies on the linear relationship between the pressure and velocity in the absence of reflected waves. This linearity of the PU-loop during early systole, which is directly related to wave speed, has always been established by eye. This paper presents a new technique that establishes this linearity and thus determining wave speed online. Pressure and flow were measured in the ascending aorta of 11 anesthetised dogs. The slope of the PU-loop, indicating wave speed was determined by eye and by using the new technique. The difference between the slopes of the two methods is in the order of 3%. The new technique is convenient and allows for the online assessment of wave speed, which could be used as a bedside tool for the assessment of arterial compliance
Maximum Speed
No full textLike Jennifer Egan’s A Visit from the Goon Squad and Muriel Spark’s The Prime of Miss Jean Brodie, Kevin Clouther’s Maximum Speed moves across time and point of view to dramatize youth’s aftershocks. The unifying presence in three characters’ lives is Billy, an apprentice drug dealer in South Florida. His improbable appearance twenty years after his death reconnects Nick, Andrea, and Jim with each other and with the shared secret of their past.https://digitalcommons.unomaha.edu/wrtswkshpfacbooks/1001/thumbnail.jp
Towards high-speed computational scattered light imaging by introducing compressed sensing for optimized illumination
No full textWe propose the application of Compressed Sensing to Computational Scattered Light Imaging to decrease measurement time and data storage. Computational Scattered Light Imaging (ComSLI) determines three-dimensional fiber orientations and crossings in biomedical tissues like brain tissue. Currently, conventional ComSLI is time-consuming and generates large data. Compressed Sensing reconstructs signals with fewer samples than required by the Shannon-Nyquist theorem with minimal perceptual loss, significantly reducing the number of measurements. We introduce an optimized illumination strategy for ComSLI based on the Discrete Cosine Transform and validate it by reconstructing characteristic scattering patterns in vervet brain tissue, thereby demonstrating the feasibility of Compressed Sensing in ComSLI.ImPhys/Menzel grou
Quantifying the role of disturbances and speeds on separated bicycle facilities
No full textAs cities aim to spur cycling, a key issue revolves around the location and quality of separated bicycle facilities. However, sometimes owing to impedances, these facilities fail to have the desired overall utility for cyclists. This study focuses on the role of non-stationary disturbances, i.e., the presence of users of other modes. The aim is to quantify the effects and frequencies of disturbances on off-street bicycle facilities (from other cyclists and pedestrians) and compare them to disturbances (from motorized vehicles) while cycling in mixed traffic. Using three segments in Bologna, Italy, we measured the frequency, type, and speed reduction attributed to different types of disturbances. We analyzed speed and likelihood of events to calculate a weighted average of the cyclists’ speed for separated bicycling facilities and on the roadway. For two of the segments, weighted speed reductions were minimal. However, in a third segment—one with considerably more disturbances—speed reductions were considerable: 20 percent for the separated facility and 40 percent for the mixed traffic. When married with cycling use patterns along the facilities, the notable speed reductions point to a possible trade-off cyclists make in choosing between different routes. The results help quantify relationships between cyclists and non-stationary disturbances; they also caution transport officials about possible unintended outcomes for separated bicycle facilities.Bernardi, Silvia; Krizek, Kevin J.; Rupi, Federico. (2016). Quantifying the role of disturbances and speeds on separated bicycle facilities. Retrieved from the University Digital Conservancy, 10.5198/jtlu.2015.715
SMEs’ international strategic decision-making speed. A purchasing perspective
No full textResearch on strategic decision-making is of great importance and has grown impressively (Elbanna, Thanos, & Papadakis, 2014). However, very few studies related to strategic decision-making process (SDMP) have been tailored on Small and medium-sized enterprises (SMEs) (Tunisini, Bocconcelli & Pagano, 2011), as the majority of these have been focused to large/multinational firms (Quintens, Pauwels, & Matthyssens, 2006). At the same time, few studies (Francioni, Musso & Cioppi, 2015) attempt to combine the field of analysis of SDMP with that of international strategy, especially with reference to import activities. Finally, just one study (Kaufmann & Gaeckler, 2015) analyzed decision-making speed in purchasing.
Therefore, the main purpose of our study is to provide theory and testing to elucidate the role of decision-maker’s speed during global sourcing decision-making (GSDM) processes. In order to achieve this goal, the research focus will examine the behavior of Italian small manufacturing companies
The mediating role of speed in the global sourcing decision process
No full textThe principal aim of this study is to provide theory and testing to elucidate the role of decision-maker's decision process and speed during the global sourcing decision-making process (GSDP). In order to achieve this goal, we examine the behavior of a sample of 202 decision-makers belonging to Italian SMEs in the manufacturing sector. Our main finding suggests that faster decisions during the GSDP process lead to superior financial and non-financial performance of the selected supplier. Moreover, we find support for dual processing theory wherein rationality and intuition of the GSDP are associated with increased supplier performance both directly and through their effects on decision speed. Results are discussed in terms of the GSDP, SME and strategic decision-making literatures and practical implications for managers in SMEs
Typical cruising speed of speed pedelecs and the link with motor power as a result of a Belgian naturalistic cycling study
No full textElectric bicycles are on the rise. In 2015, 6.54% of the bicycles sold in Europe provided electrical assistance. Belgium is traditionally one of the frontrunners, with an e-bike market share of 39.2% in 2016. Most e-bikes are classical pedelecs, limited in the European Union to a maximum assistance speed of 25 km/h and a maximum continuous rated power of 250W. More recently, speed pedelecs were introduced, exceeding these limitations with a maximum assistance speed of 45 km/h and a typical maximum continuous rated power of 350W or 500W. These electric two-wheelers have a high potential for attracting the younger consumer while lengthening the active commuting range up to 40 km. In this paper preliminary results of a Belgian naturalistic cycling study with more than 40 speed pedelec users are presented, including the correlation between the cruising speeds of different types of speed pedelecs and the maximum continuous rated power of these cycles. (Author/publisher
Relationship between hockey skating speed and selected performance measures
No full textThe objective of this study was to determine the relationship between specific performance measures and hockey skating speed. Thirty competitive secondary school and junior hockey players were timed for skating speed. Off-ice measures included a 40-yd (36.9-m) sprint, concentric squat jump, drop jump, 1 repetition maximum leg press, flexibility, and balance ratio (wobble board test). Pearson product moment correlations were used to quantify the relationships between the variables. Electromyographic (EMG) activity of the dominant vastus lateralis and biceps femoris was monitored in 12 of the players while skating, stopping, turning, and performing a change-of-direction drill. Significant correlations (p < 0.005) were found between skating performance and the sprint and balance tests. Further analysis demonstrated significant correlations between balance and players under the age of 19 years (r = -0.65) but not those over 19 years old (r = -0.28). The significant correlations with balance suggested that stability may be associated with skating speed in younger players. The low correlations with drop jumps suggested that short contact time stretch-shortening activities (i.e., low amplitude plyometrics) may not be an important factor. Electromyographic activities illustrated the very high activation levels associated with maximum skating speed. ABSTRACT FROM AUTHORPeer reviewedFinal article publishedelectromyographystrengthflexibilityspeedbalanc
The future of the independent travel agent: the need for strategic choice
No full textThis paper provides a contemporary example of the disruptive impact of new technology upon industry structure, through investigation into the ongoing viability of retail travel agents in an industry where technology is a key driver of change. The Internet has provided opportunities for major travel suppliers to target customers direct, potentially circumventing the traditional distribution channel through the travel agent.The data has been obtained from questionnaires, telephone interviews and personal experience of managing a tour operator and a travel agency, plus material from trade organizations such as ABTA. The objective was to identify potential opportunities for independent travel agents to respond to the challenges of disintermediation. The respondents provided a variety of perspectives as they included sales staff at the customer interface right through to key industry leaders.The paper concludes from the data analysis that the independent travel agent has a future provided it makes appropriate investment in technology, works closely with niche tour operators and creates competitive differentiation by focusing on specialist markets where core assets such as staff expertise can add value to the buying process and prevent the customer from going it alone.The research indicates that the Internet is complementing rather than replacing existing business priorities in the travel industry. While sales of dynamically packaged products through Internet technology are growing at the expense of more traditional holidays, the latter still represents a significant aspect of the overall travel business. Travel agents can potentially add value in both of these business areas
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