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1.
The exact role and the function of the scapula are misunderstood in many clinical situations. This lack of awareness often translates into incomplete evaluation and diagnosis of shoulder problems. In addition, scapular rehabilitation is often ignored. Recent research, however, has demonstrated a pivotal role for the scapula in shoulder function, shoulder injury, and shoulder rehabilitation. This knowledge will help the physician to provide more comprehensive care for the athlete. This "Current Concepts" review will address the anatomy of the scapula, the roles that the scapula plays in overhead throwing and serving activities, the normal biomechanics of the scapula, abnormal biomechanics and physiology of the scapula, how the scapula may function in injuries that occur around the shoulder, and treatment and rehabilitation of scapular problems.  相似文献   
2.
This paper discusses a technique for supporting omniscient debugging for model transformations, which are used to define core operations on software and system models. Similar to software systems developed using general-purpose languages, model transformations are also subject to human error and may possess defects. Existing model-driven engineering tools provide stepwise execution to aid developers in locating and removing defects. In this paper, we describe our investigation into a technique and associated algorithms that support omniscient debugging features for model transformations. Omniscient debugging enables enhanced navigation and exploration features during a debugging session beyond those possible in a strictly stepwise execution environment. Finally, the execution time performance is comparatively evaluated against stepwise execution, and the scalability (in terms of memory usage) is empirically investigated.  相似文献   
3.
We utilize the bibliometric tool of co-word analysis to identify trends in the methods and subjects of ecology during the period 1970–2005. Few previous co-word analyses have attempted to analyze fields as large as ecology. We utilize a method of isolating concepts and methods in large datasets that undergo the most significant upward and downward trends. Our analysis identifies policy-relevant trends in the field of ecology, a discipline that helps to identify and frame many contemporary policy problems. The results provide a new foundation for exploring the relations among public policies, technological change, and the evolution of science priorities.  相似文献   
4.
In-training residency evaluation   总被引:1,自引:0,他引:1  
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5.
Samples of chloral homopolymers and copolymers with aromatic isocyanates of high chloral content were prepared by cryotachensic polymerization as films of 0.1 to 5 mm thickness. Thermal, mechanical, and electrical properties of these polymers were measured. Polychloral is unlike most other linear polymers as it does not show any melting or glass transition below 220°C, at which temperature the polymer starts to degrade by depolymerization to monomer. The polymer is of moderate crystallinity and shows properties characteristic of engineering plastics.  相似文献   
6.
Pareto optimization is shown to be equivalent to a fixed point problem for a certain multivalued function. This viewpoint provides a solution procedure for some problems.  相似文献   
7.
Strunk CW  Sides PJ 《Applied optics》2004,43(10):2046-2053
Scattered total internal reflection of visible light is used to measure linear nanometric distance to as small as 10 nm. Specifically, we measure the height of magnetic transducer heads above a rotating glass disk. A breakthrough in the approach to calibration, based on combining the second derivative of the transmittance of the scattered light and parameter fitting, substantially improves the quality of the measurement relative to previous demonstrations of this method. The results agree to 1 nm with an industry-standard three-color interferometer to and including the lowest values measured. The technique in principle remains robust to as low as the zero height. Furthermore the calibration point can be as low as 10 nm, which is especially attractive in practice.  相似文献   
8.
This paper addresses self-sensing (“sensorless”) control of salient-pole permanent magnet synchronous motors (PMSMs). The major contribution of this work is the introduction of a simple-to-implement estimation technique that operates over a wide speed range, including zero speed. The technique achieves simplicity by decoupling the inherent cross-coupling in PMSMs. The technique utilizes the dependence of inductance on rotor position in interior permanent magnet machines to produce position and velocity estimates both for field orientation and for all motion control of the drives. The technique functions in a manner similar to a resolver and resolver-to-digital converter (RTDC) sensing system, whereby in the proposed technique the motor acts as the electromagnetic resolver and the power converter applies carrier-frequency voltages to the stator which produce high-frequency currents that vary with position. The sensed currents are then processed with a heterodyning technique that produces a signal that is approximately proportional to the difference between the actual rotor position and an estimated rotor position. This position error signal and a torque estimate are then used as inputs to a Luenberger style observer to produce parameter insensitive, zero lag, position and velocity estimates  相似文献   
9.
Assessment of Concrete in Sulfate Soils   总被引:1,自引:0,他引:1  
An investigation of concrete exposed to sulfate soils is used to illustrate a methodology for the systematic study of the condition of concrete in service. Condition surveys of the site and tests of engineering properties of the concrete were supplemented by examination of concrete cores using the stereomicroscope, the optical microscope, the electron microscope, analysis by wet chemistry, thermal analysis, and X-ray diffraction. Step-by-step progression from large scale (tens of meters) to submicroscopic scales (tens of nanometers) gave continuity to detailed test methods. It also allowed for the selection of specimens appropriately representing the concrete as a whole, and ensured reliable interpretation of the results. In many cases, more than one test method provided the same or similar information. The writers believe the methodology employed will be of value to other investigators.  相似文献   
10.
The authors tested the hypothesis that the cholinergic nucleus basalis magnocellularis (NBM) is involved in solving problems requiring cognitive flexibility. Rats with 192 IgG-saporin lesions of the NBM were assessed for perseveration (i.e., cognitive inflexibility) in the serial reversal of an operant discrimination and during subsequent extinction testing. It was hypothesized that the NBM lesion and control groups would not differ in the acquisition of the initial, simple discrimination, because this task does not demand cognitive flexibility. In contrast, it was hypothesized that the NBM lesion group would show perseveration during serial reversal and extinction testing. Results generally supported these hypotheses, suggesting that the NBM plays an important role in mediating cognitive flexibility. (PsycINFO Database Record (c) 2010 APA, all rights reserved)  相似文献   
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