Movement sequencing disorders in Parkinson's disease

Ten PD patients and ten age-matched normal controls learned a sequence of 3 or 4 different hand movements to a criterion of 5 consecutive correct trials. They also performed a control sequence of 3 or 4 movements which involved the repetition of the same hand posture. Trials to reach criterion, errors, total response time and its components, response time for each movement and inter-response time were examined. There were no group differences in trials to criterion or errors. Total movement time as well as response and inter-response times were significantly longer for the PD patients, however, but only for sequences involving different hand movements not for the repetitive sequences. The relative timing of the responses was also different with the PD patients spending proportionately more time on each response and the controls spending more time between responses. The implications of these findings for understanding the movement sequencing impairments in PD are discussed.     

Magnetic induction micromachine-part III:Eddy currents and nonlinear effects

The magnetic induction micromachine fabricated in Part II was not laminated, as designed in Part I. Consequently, eddy currents in the stator core, and the associated nonlinear saturation, significantly decreased its performance from that predicted in Part I. To investigate and explain these phenomena and their consequences, this paper models the behavior of the solid-stator-core machine fabricated in Part II using a finite-difference time-domain numerical analysis. The inherent stiffness in the time-domain integration of Maxwell's equations is mitigated via reducing the speed of light artificially by five orders of magnitude, while taking special care that assumptions of magneto-quasi-static behavior are still met. The results from this model are in very good agreement with experimental data from the tethered magnetic induction micro motor.     

61单元分立式压电变形反射镜的研制

用于校正波前误差的61单元分立式压电变形反射镜是61单元自适应光学系统（AO）的关键器件之一。由于系统对单元数（61单元）和变形量（±3μm）的要求超过以往曾研制的变形镜，对研制工作带来许多困难。我们从理论分析到工艺研究采取措施，使研制的变形镜成功用于AO系统实验。     

Implementing CS1 with embedded instructional research design in laboratories

Closed laboratories are becoming an increasingly popular approach to teaching introductory computer science courses. Unlike open laboratories that tend to be an informal environment provided for students to practice their skills with attendance optional, closed laboratories are structured meeting times that support the lecture component of the course, and attendance is required. This paper reports on an integrated approach to designing, implementing, and assessing laboratories with an embedded instructional research design. The activities reported here are parts of a departmentwide effort not only to improve student learning in computer science and computer engineering (CE) but also to improve the agility of the Computer Science and Engineering Department in adapting the curriculum to changing technologies, incorporate research, and validate the instructional strategies used. This paper presents the design and implementation of the laboratories and the results and analysis of student performance. Also described in this paper is cooperative learning in the laboratories and its impact on student learning.     

Self-stabilized nonlinear lateral modes of broad area lasers

The lateral modes of broad area lasers are investigated theoretically. The nonlinear interaction between optical field and effective refractive index leads to a saturable nonlinearity in the governing field equation, so that self-modulated solutions are found to be stable with increased current injection above saturation intensity. We derive approximate analytical solutions for traveling wave fields within the broad area laser. The field amplitude consists of a small ripple superimposed on a large dc value. Matching fields at the boundary determines the modulation depth and imparts an overall phase curvature to the traveling wave mode. There are multiple lateral modes for a given set of operating conditions, and modes with successively more lobes in the ripple have greater overall phase curvature. In contrast to the linear problem, several lateral modes can achieve the same modal gain, for a given injected current density, by saturating the gain to different extent. Thus, these modes would exhibit slightly different optical powers.     

Multitemporal passive microwave mapping in MACHYDRO'90

MACHYDR0'90 was an experiment conducted in Pennsylvania in 1990 to study the synergistic use of remote sensors in multitemporal hydrologic studies. As part of this mission the pushbroom microwave radiometer was flown and used to produce brightness temperature maps. Verification studies and vegetation algorithms for mixed land cover areas are described     

Parkinson's disease. Second of two parts

At no time in the past have the basic and clinical sciences applied to Parkinson's disease been so active. Experimental therapies under study at present promise to improve on the limitations of existing treatments. Future progress in understanding the causation and pathogenesis of the disorder will permit the development of new treatments that will slow, halt, or even reverse the currently inexorable progressive course of Parkinson's disease.     

An optimum parallel architecture for high-speed real-time digital signal processing

The authors describe a parallel processing architecture for real-time digital signal processing that has demonstrated virtually 100% data processing efficiency in a number of areas. The Teamed-Architecture Signal Processor (T-ASP) is a field-proven, commercially available optimal system solution to the extremely high computational and I/O rates encountered in modern digital-signal-processing environments. The design of T-ASP involves the consideration and implementation of many architectural concepts used to enhance the performance of a computer, including programmability, parallel processing, vector processing and pipelining, memory interleaving, double cache memories, multiple high-speed I/O interfaces, and segmentation of the processors for elimination of both CPU and data-handling overhead. The authors discuss hardware architecture design and implementation; hardware management; and software architecture design and implementation.<>