668,436 research outputs found

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    Use of scenario evaluation in preparation for deployment of a collaborative system for knowledge transfer - the case of KiMERA

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    This paper presented an approach for the evaluation of a collaborative system, after the completion of system development and software testing but before its deployment. Scenario and collaborative episodes were designed and data collected from users role-playing. This was found to be a useful step in refining the user training, in setting the right level of user expectation when the system started to roll-out to real users and in providing feedback to the development team

    A New Larval Record of \u3ci\u3ePerlinella Drymo\u3c/i\u3e (Plecoptera: Perlidae) for Michigan

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    The presence of larvae of Perlinella drymo in Michigan is documented for the first time. A total of 7 individuals were collected from Iron Creek, a tributary of the River Raisin watershed located in southeastern Michigan. Gut analysis of one specimen provided evidence for a carnivorous diet. The location from which larvae were collected indicate a preference during winter for stabilized undercut banks with little or no flow and accumulated organic debris upon sand and gravel substrate

    Viewpoint

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    Though many writers are happy to put a date on the day a Japanese (or was it a Finn?) coined this rather ungainly word, mechatronics has been around in spirit for many decades. My first brush with industry nearly half a century ago involved designing autopilots. Their early computing circuits used analogue magnetic amplifiers rather than the digital microcomputer we would expect today. But a machine that trundled through the sky, obeying commands computed from a multitude of sensor signals that enabled it to make a perfect automatic landing must surely be worthy of being called a robot. By the early 1970s, we could buy 'budget' single-board computers for a thousand British pounds. Although these had a mere sixteen kilobytes of memory, their potential for mechatronics was immense. One of my Cambridge researchers took on the task of revolutionizing the phototypesetter. The method is now commonly found in the laser printer. A spinning mirror scans a laser beam across the photosensitive film, letter shapes are held in computer memory and the entire mechanical design is greatly simplified. I consider this trade-off between mechanics, electronics and computing power to be the guiding principle of mechatronics. The research team were soon knitting similar computers into a variety of real-time applications, including an 'acoustic telescope' to build the signals from 14 microphones into an image of the sound source. Hydrofoils were simulated, violins were analysed for their 'Stradivarius-like qualities' and music was synthesized. A display for a colour television, novel in those days, depended on a minimum of electronics and a wealth of software. But computing power soon came in ever smaller packages. In 1979, planning started for holding the Euromicro conference in London. The chairman wanted an added showpiece and his mind was on 'The Amazing Micromouse Maze Contest' that had just been announced by IEEE Spectrum. I put my hand up to organize the contest. Then I started to follow the news from the USA. Blows were nearly exchanged when the 'dumb wall followers' sprinted through the maze from the entrance at one corner to the exit at the other, much faster than their brainier rivals. How could the rules be massaged to give brains the edge? The solution was to give the mouse-builders more specific information that could be designed into the logic of their machines. Our maze was specified as sixteen squares by sixteen, with the target at the centre, not on the edge. In that way, paths could circle the centre to form 'moats' that no mere wall-follower could cross. A preliminary run was held in Portsmouth in July, with results that literally gave me nightmares. Of the six mice that competed, only one could make any attempt to follow a passageway, let alone find the centre. At the conference in September, fifteen mice competed. The winner was a clanking contraption, cobbled together around a brilliant maze-solving algorithm that has remained relevant to this day. The contest went from strength to strength, being held in Paris, Tampere, Madrid and Copenhagen, but for these first few years something struck me as strange. Not one of the winners was trained as an engineer. Great machines came from mathematicians, computer maintenance staff, programmers for manufacturing industry, but formally qualified engineers were notable by their absence. So what is it that defines a mechatronic engineer? What is the special aptitude that singled out these champions? What had they learned from their endeavours that was not to be found in a formal engineering course? They were able to put together a concept in which strategy, computing hardware, sensors, electronics and motors were blended together in harmony, not as a cobbled assembly of diverse technologies. So what of the next generation of mechatronic engineers? How do we give them skill and ability with the essentials, without deluging them with the entire contents of the textbooks of at least three diverse disciplines? We must distil the 'good bits' from the diverse range of specializations that make up engineering as a whole. The Micromouse experience suggests that hands-on experimentation is an essential ingredient. While learning, software must be ‘crafted’ by the student, rather than being ladled into the project as a bought-in commodity. The student must be prepared to deal with hydraulics or electro-mechanics, treating them as two sides of the same coin. Mechatronics is special. It is no more a mere mixture of electronics, mechanics and computing than a Chateau Latour is a mixture of yeast and grape-juice

    Comparing Profitability for Game Developers: Xbox vs PlayStation vs PC

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    Ever since the beginning of the video game industry, consoles have come and gone such as the Atari 2600 and the Nintendo Gameboy. However, there are two main series of consoles that have continued to modern day: the Xbox’s and the PlayStation’s. These two series of consoles have been rivals for more than a decade, consistently releasing systems to compete with each other. Furthermore, similar to consoles coming and going, many companies have gone bankrupt due to significant gaming failures and losses. Because of this, there are only few major companies still producing games, along with some independent game developers struggling to succeed. However, more successful, independent companies and developers means a greater variety of games for consumers to play. Therefore, I determined which series of consoles appears to be the more profitable series for small companies and individual developers. Along with these series of consoles, the gaming industry for the PC has recently expanded rapidly and appears to be more friendly to low-budget games. Therefore, I analyzed PC game sales and concluded where should new video-game developers invest their time and money for producing games: for Xbox’s, PlayStation’s, or the PC

    Chenango Forks Central School District and Chenango Forks Supervisory Association (2005)

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    Interpretations of Calabresi

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    Investigation on different composition of powder metallurgy electrode (Cu-W) in high performance edm (HPEDM) on AISI D2 hardened steel

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    The ideal selection of manufacturing conditions is one of the most important aspects to take into consideration in the majority of manufacturing processes and particularly in processes related to Electrical Discharge Machining (EDM). EDM die sinking machines are used to machine conductive metals of any hardness or difficult to machine with traditional methods. The problem in the capabilities of tool electrodes which are not utilized at the optimum levels of the operating parameters has attracted the attention of researchers and practicing engineers to manufacture tool electrodes with highly great performance. In this work, an experimental design was conducted to characterize the machining performances and surface integrity of three different composition of copper tungsten (CuW) tool electrode in EDM of D2 hardened steel (58-62 HRC). Machining performances i.e. material removal rate (MRR), tool wear rate (TWR), workpiece surface roughness (Ra) and micro-hardness (MH) were studied for the three different composition of CuW tool electrode made through powder metallurgy (PM) method. Machining variables were peak current and pulse duration, meanwhile machining voltage, depth of cut and duty factor were kept constant. The 65%W electrode is the best choice of CuW electrode on machining D2 hardened steel due to the highest machining rate, reasonable tool wear rate and acceptable surface characteristics. The improvement of MRR is obviously affected by the increment of current intensity. MRR increased as the value of peak current increased. The increment of pulse duration is not essentially improving MRR. There is no clear relation between the alteration of pulse duration and MRR. However, the MRR becomes the optimum at an optimal set of variables which is set at 40A and 400µs. The results of the machining performance can extent the availability of database on EDM machinability and surface characteristics of D2 hardened steel for machinist practices in industrial application of roughing operation

    The Adjudication of Minor Offenses in New York City

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    American criminal justice is founded on overcriminalization and discretion. Our legislatures have long criminalized much more conduct than can be effectively sanctioned. American police and prosecutors have been granted virtually unreviewable authority (discretion) to allocate investigative and prosecutorial resources. Minor crimes absorb the bulk of our ordinary, local enforcement efforts and there is an endless supply of minor crime, which may be pursued. With minor offenses, discretion is critical at all phases. This article argues that criminal courts, where ninety percent of all cases are heard, could benefit from reform. The author argues for the development of the record so that these offenses are adjudicated on the merits, rather than merely processed
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