A high sensitivity process variation sensor utilizing sub-threshold operation

In this paper, we propose a novel low-power, bias-free, high-sensitivity process variation sensor for monitoring random variations in the threshold voltage. The proposed sensor design utilizes the exponential current-voltage relationship of sub-threshold operation thereby improving the sensitivity by 2.3X compared to the above-threshold operation. A test-chip containing 128 PMOS and 128 NMOS devices has been fabricated in 65nm bulk CMOS process technology. A total of 28 dies across the wafer have been fully characterized to determine the random threshold voltage variations

Study of space charge phenomena in GEM-based detectors

Space charge accumulation within GEM holes is one of the vital phenomena which affects many of the key working parameters of the detector. This accumulation is found to be significantly affected by the initial primary charge configurations and applied GEM voltages since they determine charge sharing and the subsequent evolution of detector response. In this work, we have studied the effects of space charge phenomena on different parameters for single GEM detectors using a hybrid numerical model

Distribution and inter-regional relationship of amyloid-beta plaque deposition in a 5xFAD mouse model of Alzheimer’s disease

Alzheimer’s disease (AD) is the most common form of dementia. Although previous studies have selectively investigated the localization of amyloid-beta (Aβ) deposition in certain brain regions, a comprehensive characterization of the rostro-caudal distribution of Aβ plaques in the brain and their inter-regional correlation remain unexplored. Our results demonstrated remarkable working and spatial memory deficits in 9-month-old 5xFAD mice compared to wildtype mice. High Aβ plaque load was detected in the somatosensory cortex, piriform cortex, thalamus, and dorsal/ventral hippocampus; moderate levels of Aβ plaques were observed in the motor cortex, orbital cortex, visual cortex, and retrosplenial dysgranular cortex; and low levels of Aβ plaques were located in the amygdala, and the cerebellum; but no Aβ plaques were found in the hypothalamus, raphe nuclei, vestibular nucleus, and cuneate nucleus. Interestingly, the deposition of Aβ plaques was positively associated with brain inter-regions including the prefrontal cortex, somatosensory cortex, medial amygdala, thalamus, and the hippocampus. In conclusion, this study provides a comprehensive morphological profile of Aβ deposition in the brain and its inter-regional correlation. This suggests an association between Aβ plaque deposition and specific brain regions in AD pathogenesis

A Low Power High Performance Multiplexed Keeper Technique

This paper presents a technique to improve the performance of wide dynamic circuits by efficiently using the conditional keeper. PMOS transistor which is used to charge the dynamic node in the precharge phase is also used as a conditional keeper in the evaluation phase. The keeper functionality is merged in precharge PMOS. It is found that at same DC noise robustness; this technique gives 9% improvement in delay, 14% improvement in power and 18% improvement in clock load compared to conditional keeper technique. Further, this technique gives zero delay penalties but higher noise immunity compared to conventional dynamic circuits

Comparative Structural Analysis of 2-DOF Semi-Direct Drive Linkages for Robot Arms

This paper reports the first direct structural comparison of a family of 2-DOF semi-direct drive linkages for robot arms. One novel and three previously reported linkage designs were optimized and compared using finite-element analysis. The results quantify structural properties of the four optimized designs under variations in joint position and payload. Several frequently overlooked issues essential for fair comparison of disparate linkages are identified and addressed

Structural Design Optimization and Comparative Analysis of a New High-Performance Robot Arm via Finite Element Analysis

This paper reports the structural design of a new high-performance robot arm. Design objectives for the new arm include large (1-2 meter) workspace, low weight, 5 kg payload capacity, high stiffness, high structural vibration frequencies, precise joint-level torque control, a total of three degrees-offreedom, and mechanical simplicity. A comparative analysis is reported for four very different two degree-of-freedom linkage candidates using the finite element method. The authors gratefully acknowledge the support of the National Science Foundation under CAREER grant BES9625143 awarded to the last author. Correspondence Address: 123 Latrobe Hall, 3400 North Charles Street, Baltimore, Maryland, 21218, email addresses: [email protected], [email protected]. A preliminary version of this paper was presented at the 1997 IEEE International Conference on Robotics and Automation, Albuquerque,New Mexico. 1 Introduction Our goal is to design and build a robot arm for high performance tracking and force c..