THE BIOMECHANICAL ANALYSIS OF ROUNDHOUSE KICK IN TAEKWONDO

The purpose of this research was to compare 360° turning roundhouse kick performed by dominant leg and non-dominant leg on kinetic and kinematic variables, and then to find the variables that correlate to the impact velocity. Nine elite taekwondo athletes were recruited. The data were collected with two Redlake cameras (125 Hz) and two Kistler force plates (1250 Hz). The difference between maximal height and beginning of body CM, max velocity of toe/ankle, impact velocity of toe, maximal vertical force of front leg, vertical/horizontal impulse of front leg, were found to be significantly different between dominant and non-dominant leg; and the difference between maximal height and impact of body CM, max velocity of toe/ankle, maximal vertical force of back leg were found to be significantly correlated with the impact velocity

Low Polarization Voltage and High Sensitivity CMOS Condenser Microphone Using Stress Relaxation Design

AbstractIn this paper, a CMOS condenser microphone with high sensitivity and low polarization voltage was designed, simulated and fabricated. Due to CMOS process temperature variant and lattice defects, the poly-membrane would be invoked normal stress and gradient stress. These two residual stresses would deform the membrane and increase the membrane's rigidity. For these concerns, an interlace slots design is utilized to reduce the normal stress up to 90%, and the annealing process is applied to decrease the gradient stress. The acoustical sensitivity was increased considerably to -45dBV at 2.7V bias voltage, and, the noise level is -85dBV at 1KHz

DIFFERENCES BETWEEN MALE AND FEMALE PLAYERS IN THE FRONTAL PLANE BIOMECHANICS DURING VOLLEYBALL SPIKE LANDING

The purpose of this study was to investigate differences of kinematic variables between male and female volleyball players after a spiking, to understand the mechanism of volleyball spike landing. Eight males and eight females were recruited to participate in this study from the university volleyball team. The kinematic data were collected by ten Vicon cameras (300Hz) and two force plates (1500Hz). The results presented the right hip joint, and both knee joints are significant differences between male and female volleyball players at initial contact. Similarly, at the moment of peak force during the landing phase, the right hip joint and both knee joints are significant differences between male and female volleyball players. These differences demonstrated that male and female players performed different strategies during volleyball spike landing

Energy-efficient wireless sensors : fewer bits, Moore MEMS

Thesis (Ph. D.)--Massachusetts Institute of Technology, Dept. of Electrical Engineering and Computer Science, 2011.Cataloged from PDF version of thesis. Page 184 blank.Includes bibliographical references (p. 171-183).Adoption of wireless sensor network (WSN) technology could enable improved efficiency across a variety of industries that include building management, agriculture, transportation, and health care. Most of the technical challenges of WSNs can be linked to the stringent energy constraints of each sensor node, where wireless communication and leakage energy are the doninant components of active and idle energy costs. To address these two limitations, this thesis adopts compressed sensing (CS) theory as a generic source coding framework to minimize the transmitted data and proposes the use of micro-electro-mechanical (MEM) relay technology to eliminate the idle leakage. To assess the practicality of adopting CS as a source coding framework we examine the inpact of finite resources, input noise, and wireless channel impairments on the compression and reconstruction performance of CS. We show that CS, despite being a lossy compression algorithm, can realize compression factors greater than loX with no loss in fidelity for sparse signals quantized to medium resolutions. We also model the hardware costs for implementing the CS encoder and results from a test chip designed in a 90 nm CMOS process that consumes only 1.9 [mu]W for operating frequencies below 20 kHz, verifies the models. The encoder is desioned to enable continuous, on-the-fly compression that is demonstrated on electroencephalography (EEG) and electrocardiogram (EKG) signals to show the applicability of CS. To address sub-threshold leakage, which limits the energy performance in CMOS-based sensor nodes, we develop design methodologies towards leveraging the zero leakage characteristics of MEM relays while overcoming their slower switching speeds. Projections on scaled relay circuits show the potential for greater than loX improvements in energy efficieicy over CMOS at up to 10-100 Mops for a variety of circuit sub-systems. Experimental results demonstrating functionality for several circuit building blocks validate the viability of the technology, while feedback from these results is used to refine the device design. Incorporating all of the design elements, w present simnulation results for our most recent test chip design which implements relay-based versions of the CS encoder circuits in a 0.25 jim lithographic process showing 5X improvement over our 90 nm CMOS design.by Fred Chen.Ph.D

AdapterBias: Parameter-efficient Token-dependent Representation Shift for Adapters in NLP Tasks

Transformer-based pre-trained models with millions of parameters require large storage. Recent approaches tackle this shortcoming by training adapters, but these approaches still require a relatively large number of parameters. In this study, AdapterBias, a surprisingly simple yet effective adapter architecture, is proposed. AdapterBias adds a token-dependent shift to the hidden output of transformer layers to adapt to downstream tasks with only a vector and a linear layer. Extensive experiments are conducted to demonstrate the effectiveness of AdapterBias. The experiments show that our proposed method can dramatically reduce the trainable parameters compared to the previous works with a minimal decrease in task performances compared with fine-tuned pre-trained models. We further find that AdapterBias automatically learns to assign more significant representation shifts to the tokens related to the task in consideration.Comment: The first two authors contributed equally. This paper was published in Findings of NAACL 202

Interaction of an edge dislocation with a coated elliptic inclusion

a b s t r a c t This paper presents an analytical solution for plane elasticity problems of an elliptically cylindrical layered media subject to an arbitrary edge dislocation. Based on the technique of conformal mapping and the method of analytical continuation in conjunction with the alternating technique, the general expressions of the displacements and stresses, where an edge dislocation is located in matrix, coating layer and inclusion are obtained. The numerical results of image forces exerted on a generalized edge dislocation are carried out by using the generalized Peach-Koehler equation. As a numerical illustration, both the image forces and equilibrium positions are presented for different material combinations and relative thickness of a coating layer. The result shows that the thickness and the shear modulus of the coating layer have a strong influence on the stability of dislocation

Carcinoma ex pleomorphic adenoma of soft palate with cavernous sinus invasion

<p>Abstract</p> <p>Background</p> <p>Carcinoma ex pleomorphic adenoma (CXPA) is an aggressive salivary gland malignancy and rare in minor salivary gland. A soft palate CXPA initially presenting as direct cavernous sinus (CS) invasion is very rare.</p> <p>Case Presentation</p> <p>A 60-year-old male had a 3-month history of a small soft palatal mass with progressing left cheek numbness, proptosis, and disturbed vision. Biopsy of soft palatal tumor showed pleomorphic adenoma. Magnetic resonance imaging showed a tumor involving left maxilla, and extended from pterygopalatine fossa, inferior orbital fissure to CS. Excision of tumor revealed CXPA. Adjuvant concomitant chemo-radiation therapy (CCRT) was given. The tumor recurred 5 months later in left CS which was re-treated with CCRT. The disease status was stable at 2 years after the diagnosis of CXPA.</p> <p>Conclusion</p> <p>We present this case to emphasize that patients with symptoms such as facial numbness, proptosis and disturbed vision should be carefully investigated for lesions invading CS by perineural spread.</p