Simplified Frame and Symbol Synchronization for 4–CPFSK with h=0.25

This paper examines the problem of rapid frame and symbol synchronization techniques intended particularly for constant envelope modulation formats M–CPFSK with modulation index h=1/M which are used in strictly bandwidth limited narrowband industrial applications. The data aided and non data aided versions of the algorithm based on digital frequency discrimination are discussed and compared against the synchronization techniques found in literature. Sample wise pattern correlation technique for joint frame and symbol synchronization is also studied. With the focus on a practical digital implementation the advantages and disadvantages of the described approaches are discussed

Implementation of Industrial Narrow Band Communication System into SDR Concept

The rapid expansion of the digital signal processing has penetrated recently into a sphere of high performance industrial narrow band communication systems which had been for long years dominated by the traditional analog circuit design. Although it brings new potential to even increase the efficiency of the radio channel usage it also forces new challenges and compromises radio designers have to face. In this article we describe the design of the IF sampling industrial narrowband radio receiver, optimize a digital receiver structure implemented in a single FPGA circuit and study the performance of such radio receiver architecture. As an evaluation criterion the communication efficiency in form of maximum usable receiver sensitivity, co-channel rejection, adjacent channel selectivity and radio blocking measurement have been selected

Validation of the German Revised Addenbrooke's Cognitive Examination for Detecting Mild Cognitive Impairment, Mild Dementia in Alzheimer's Disease and Frontotemporal Lobar Degeneration

Background/Aims: The diagnostic accuracy of the German version of the revised Addenbrooke's Cognitive Examination (ACE-R) in identifying mild cognitive impairment (MCI), mild dementia in Alzheimer's disease (AD) and mild dementia in frontotemporal lobar degeneration (FTLD) in comparison with the conventional Mini Mental State Examination (MMSE) was assessed. Methods: The study encompasses 76 cognitively healthy elderly individuals, 75 patients with MCI, 56 with AD and 22 with FTLD. ACE-R and MMSE were validated against an expert diagnosis based on a comprehensive diagnostic procedure. Statistical analysis was performed using the receiver operating characteristic method and regression analyses. Results: The optimal cut-off score for the ACE-R for detecting MCI, AD, and FTLD was 86/87, 82/83 and 83/84, respectively. ACE-R was superior to MMSE only in the detection of patients with FTLD {[}area under the curve (AUC): 0.97 vs. 0.92], whilst the accuracy of the two instruments did not differ in identifying MCI and AD. The ratio of the scores of the memory ACE-R subtest to verbal fluency subtest contributed significantly to the discrimination between AD and FTLD (optimal cut-off score: 2.30/2.31, AUC: 0.77), whereas the MMSE and ACE-R total scores did not. Conclusion: The German ACE-R is superior to the most commonly employed MMSE in detecting mild dementia in FTLD and in the differential diagnosis between AD and FTLD. Thus it might serve as a valuable instrument as part of a comprehensive diagnostic workup in specialist centres/clinics contributing to the diagnosis and differential diagnosis of the cause of dementia. Copyright (C) 2010 S. Karger AG, Base

Lower Limb Motor Coordination and Rehabilitation Facilitated through Self- Assist.

Self-assisted rehabilitation of neurological injury through patient-operated telerobots offers potential benefits over traditional therapy including increased patient involvement, improved timing coordination, and better sensory information. Bimanual self-assist has been clinically shown to demonstrate greater improvements in range of motion and functional recovery than traditional therapy alone. This dissertation generalizes self-assist to lower limb rehabilitation with upper limb assistance, providing a scientific foundation for the mechanisms of self-assist. Through a series of experiments using electromechanical devices under real-time control, we have demonstrated that upper limb involvement enhances lower limb performance, improves anticipation of assistance, and maintains muscle activation. A critical concern to assistive rehabilitation is the degree to which subjects are capable of coordinating lower limb effort with the assisting effort. In a study involving lower limb disturbance rejection with neurologically intact subjects (n = 12), we found that subjects exhibit improved anticipation and compensation when externally applied loads are self-generated as opposed to generated by an outside agent. The centralized control inherent in self-assist ensures that assisting forces are expected, and even anticipated, compared to assisting forces from an external agent, such as a therapist or computer. Multi-limb control can represent a significantly increased challenge in motor planning and execution over single limb control. We evaluated the tradeoffs associated with multi-limb control in motor tasks with neurologically intact subjects (n = 7 separated into two experiments). The benefits of adding an upper limb, including increased strength and dexterity, seem to offset any detriments associated with increased control requirements, as evidenced by performance improvements relative to single limb control. In a final motor coordination study, hemiparetic subjects (n = 15) practiced dorsiflexing the impaired ankle with no assistance, upper limb self-assist, computer-assist, and experimenter-assist. We found that any assistance can be used to improve task performance, but self-assist, through improved information and awareness, maintains subject muscle recruitment and effort.Ph.D.Mechanical EngineeringUniversity of Michigan, Horace H. Rackham School of Graduate Studieshttp://deepblue.lib.umich.edu/bitstream/2027.42/61566/1/danekk_1.pd

Anodic dissolution of metals in oxide-free cryolite melts

The anodic behavior of metals in molten cryolite-alumina melts has been investigated mostly for use as inert anodes for the Hall-Héroult process. In the present work, gold, platinum, palladium, copper, tungsten, nickel, cobalt and iron metal electrodes were anodically polarized in an oxide-free cryolite melt (11%wt. excess AlF3 ; 5%wt. CaF2) at 1273 K. The aim of the experiments was to characterize the oxidation reactions of the metals occurring without the effect of oxygen-containing dissolved species. The anodic dissolution of each metal was demonstrated, and electrochemical reactions were assigned using reversible potential calculation. The relative stability of metals as well as the possibility of generating pure fluorine is discussed