Fuzzy PDFF-IIR controller for PMSM drive systems

Pseudo-derivative feedback with feed-forward gain (PDFF) combines the advantages of proportional-integral (PI) and pseudo-derivative feedback (PDF) controllers. However, PDFF responds more slowly to a command than does PI. To increase the speed of response of the PDFF controller, this work presents a PDFF with moving average errors control. A low-pass IIR filter path for errors compensation that accelerates the slow response is added to a PDFF control loop. A fuzzy inferencer is utilized to adjust the feed-forward gain and integral gain of the PDFF controller to allow closed-loop poles of the transfer function to be properly placed to improve load torque disturbance rejection capability. Simulated and experimental results reveal that the response and load disturbance rejection ability of the fuzzy PDFF-IIR controller are better than those of the traditional PDFF controller.     

A field experiment comparing information-privacy values, beliefs, and attitudes across several types of organizations.

193 randomly selected adults completed a structured interview concerning their values, beliefs, attitudes, experiences, and intentions concerning information-privacy issues involving 6 types of organizations such as employers, law enforcement agencies, and the Internal Revenue Service. Results indicate that higher valuations of informational privacy were related to lower feelings of control over personal information, less satisfaction with their perceived degree of control, and less willingness to participate in a subsequent interview. Information-privacy beliefs and attitudes varied with the type of organization under consideration. Implications are discussed in terms of organizational and societal policy concerning the treatment of information about individuals. (16 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Is hostility linked with affiliation among males and with achievement among females? A critique of Pollak and Gilligan.

Attempted to replicate and to clarify methodologically an investigation by S. Pollak and C. Gilligan (see record 1982-23594-001). Those investigators reported sex differences in violence imagery to TAT pictures depicting affiliation and achievement situations. Pollak and Gilligan concluded that men perceive danger in situations of affiliation whereas women perceive danger in situations of achievement. The present study demonstrated that Pollak and Gilligan incorrectly classified TAT cards into motivational categories, which may have resulted in incorrect inferences. In addition, their findings could not be replicated when 4 different systems for classifying TAT cards into motivational categories were used with 204 undergraduates. Other potential sources of error in their research, including a restrictive scoring scheme for hostility, unusual instructions, and failure to control for sex role in the TAT pictures, did not influence the results. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Territorial targeting in EU private law

In a series of rulings given in the last few years, the Court of Justice of the European Union (EU) has made use of the concept of targeting by a trader of a particular territorial market as a device for determining the scope of European legislation on private law. The concept is of particular importance in the context of trading activities conducted by means of the Internet, though its significance is not confined to such activities. In particular, the European Court has used the concept of targeting for the purpose of restricting the substantive ambit of intellectual property rights created or harmonised by EU legislation. On the other hand, it has avoided use of the concept of targeting in the context of EU legislation allocating jurisdiction between the courts of the Member States, even in respect of disputes involving intellectual property, except where a legislative text specifically invokes such a concept. The instant paper endeavours to review the position as currently established by the European case-law, and to predict the likely further developments.     

Human factors and education: evolution and contributions

OBJECTIVE: The major contributions of human factors to education are highlighted. BACKGROUND: Over the past 50 years, the education of human factors specialists has evolved, as well as the application of human factors and ergonomic knowledge to education. METHOD: Human factors and ergonomics professional documentation and literature were reviewed to identify major events relevant to human factors education or the application of human factors to education. RESULTS: Human factors education has evolved from training in experimental psychology to highly specialized accredited human factors programs and a number of undergraduate programs, leading to program accreditation and the certification of professionals. In addition, human factors specialists have applied their knowledge to human factors education and, more recently, to educational systems in general. The greatest focus has been on technology such as multimedia. Others have evaluated the design of the physical environment, focusing primarily on seating. The research also often targets undergraduate or graduate education. Therefore, it has been proposed that a greater focus is needed at the K-12 educational level, especially given the advancement and implementation of technology in the classroom. CONCLUSION: Human factors and ergonomic expertise can benefit the educational system. Yet, there is a need to constantly evaluate the benefits of new technology in the classroom as well as the environmental design aspects of the educational environment while considering learners of different age groups, ethnicities, and sexes. APPLICATION: Better application of human factors and ergonomics to the learning environment could enhance the educational experience for all learners.     

A memory-economic frontwidth reduction algorithm

A simple element numbering algorithm is described which yields near-minimal frontwidths for two- and three-dimensional finite element assemblies. Renumbering of E elements requires an immediate-access computer memory size which is proportional to the square root of E in two-dimensional problems, and to the two-thirds power of E in three dimensions. This very small memory requirement allows processing of large problems in minicomputers. When used in large computers, page-swapping operations are minimized.     

Absolute interferometry with a 670-nm external cavity diode laser

In the past few years there has been much interest in use of tunable diode lasers for absolute interferometry. Here we report on use of an external cavity diode laser operating in the visible (lambda ~ 670 nm) for absolute distance measurements. Under laboratory conditions we achieve better than 1-mum standard uncertainty in distance measurements over a range of 5 m, but significantly larger uncertainties will probably be more typical of shop-floor measurements where conditions are far from ideal. We analyze the primary sources of uncertainty limiting the performance of wavelength-sweeping methods for absolute interferometry, and we discuss how errors can be minimized. Many errors are greatly magnified when the wavelength sweeping technique is used; sources of error that are normally relevant only at the nanometer level when standard interferometric techniques are used may be significant here for measurements at the micrometer level.     

New Orleans Levee System Performance during Hurricane Katrina: 17th Street Canal and Orleans Canal North

Centrifuge modeling of the 17th Street Canal and Orleans Canal North levees was performed in this study. During hurricane Katrina the levees on the 17th Street Canal failed, leading to breaches in the outfall canal in the city. Two mechanisms were observed in the centrifuge modeling that could cause a breach. First, a water-filled crack formed in front of the floodwall as the water in the canal rose above the top of the levee. The levees on the 17th Street Canal, which were supported on clay foundations, failed when this cracking led to a translational (sliding) failure in the clay layer commencing at the toe of the floodwall. The levees at Orleans Canal North, where failure did not occur, were also modeled to demonstrate that the model tests could successfully simulate failure and nonfailure conditions. The centrifuge model tests identified the importance of the crack formation in relation to the stability of the floodwall. These tests also confirmed that levee geometry, floodwall depth of penetration, and the underlying soil profile were all critical to the performance of the system under flood loading.     

Co-Synthesis to a Hybrid RISC/FPGA Architecture

Hybrid architectures combining conventional processors with configurable logic resources enable efficient coordination of control with datapath computation. With integration of the two components on a single device, housekeeping tasks and, optionally, loop control and data-dependent branching, can be handled by the conventional processor, while regular datapath computation occurs on the configurable hardware. This paper describes a novel approach to programming such hybrid devices that gives the programmer control over mapping of data and computation between conventional processor and configurable logic. With a simple set of pragma and intrinsic function directives, the NAPA C language provides for manual control over perhaps the most important aspect of programming such hybrid devices. Alternatively, as experience is gained about tradeoffs between the two computational resources, mapping directives may eventually be generated by an external tool. The paper further describes a research prototype compiler that targets the hybrid processor model, with a concrete implementation for the National Semiconductor NAPA1000 chip. The NAPA C compiler parses the mapping directives, performs semantic analysis, and co-synthesizes a conventional processor executable combined with a configuration bit stream for the configurable logic. Two major compiler phases, the synthesis of pipelined loops and the datapath synthesis, are described in detail.