COMPARATIVE ANALYSIS OF MUSCLE ACTIVITIES DURING RESISTANCE EXERCISES USING VARIABLE AND ELASTIC LOADS

Over the last few decades, many resistance training devices and methods have been deve'loped for the purpose of increasing strength~ One of the most popular devices being used is variable resistance training (VRT) device (Baechle & Groves, 1992). This type of exercise machines has a major advantage that, by altering the shapes of cams, the resistance profiles at different joint positions can match the strength curve (maximum torque-angle curve) of a joint motion. Despite this advantage, the method has not been perfected and there are arguments against its effectiveness (Garhammer, 1989; Ward, 1993). The major disadvantages of this device are the relatively high cost and large space required. The elastic band exercise device such as elastic tubing is getting popular in recent years, especially in rehabilitation settings. To a certain extent, an elastic exercise device has characteristics similar to a variable resistance-training device. The major advantages of this device are its safety, inexpensiveness, and compact design. To evaluate the stresses placed on different upper arm muscles during a biceps curl using selected home exercise devices, it was the purpose of this study to examine the electromyographic (EMG) activities of the pectoralis major, biceps brachii, triceps brachii, and brachioradialis muscles during biceps curls using a VRT device and an elastic tubing

Experimental verification of the commutation relation for Pauli spin operators using single-photon quantum interference

We report experimental verification of the commutation relation for Pauli spin operators using quantum interference of the single-photon polarization state. By superposing the quantum operations $\sigma_z \sigma_x$ and $\sigma_x \sigma_z$ on a single-photon polarization state, we have experimentally implemented the commutator, $[\sigma_{z}, \sigma_{x}]$, and the anticommutator, $\{\sigma_{z}, \sigma_{x}\}$, and have demonstrated the relative phase factor of $\pi$ between $\sigma_z \sigma_x$ and $\sigma_x \sigma_z$ operations. The experimental quantum operation corresponding to the commutator, $[\sigma_{z}, \sigma_{x}]=k\sigma_y$, showed process fidelity of 0.94 compared to the ideal $\sigma_y$ operation and $|k|$ is determined to be $2.12\pm0.18$.Comment: 4pages, 3 figure

Realizing Physical Approximation of the Partial Transpose

The partial transpose by which a subsystem's quantum state is solely transposed is of unique importance in quantum information processing from both fundamental and practical point of view. In this work, we present a practical scheme to realize a physical approximation to the partial transpose using local measurements on individual quantum systems and classical communication. We then report its linear optical realization and show that the scheme works with no dependence on local basis of given quantum states. A proof-of-principle demonstration of entanglement detection using the physical approximation of the partial transpose is also reported.Comment: 5 pages with appendix, 3 figure

ELECTROMYOGRAPHICAL ANALYSIS OF TRUNK MUSCLE ACTIVITIES DURING A GOLF SWING

The purposes of this study were to describe and compare the activation patterns of the trunk muscles during a golf swing using surface electromyographic (EMG) techniques. Five male collegiate golfers were the subjects. The golf swing was broken into five phases using the critical instants identified from video recordings. Wilcoxon signed ranks tests were used to test for significant differences (12 < .05) in average and peak normalized EMG values between the left and right muscles for each phase. The significant bilateral differences in muscle activation were only found in the average and peak rectus abdominus (acceleration phase), external oblique (acceleration and early follow-through phases), and erector spinae (late follow-through phase). The trunk muscles were highly active in the follow-through phases which may indicate the hyperextension of the trunk, which leads to lower back injury

Experimental Implementation of the Universal Transpose Operation

The universal transpose of quantum states is an anti-unitary transformation that is not allowed in quantum theory. In this work, we investigate approximating the universal transpose of quantum states of two-level systems (qubits) using the method known as the structural physical approximation to positive maps. We also report its experimental implementation in linear optics. The scheme is optimal in that the maximal fidelity is attained and also practical as measurement and preparation of quantum states that are experimentally feasible within current technologies are solely applied.Comment: 4 pages, 4 figure

Temperature dependence of Mott transition in VO_2 and programmable critical temperature sensor

The temperature dependence of the Mott metal-insulator transition (MIT) is studied with a VO_2-based two-terminal device. When a constant voltage is applied to the device, an abrupt current jump is observed with temperature. With increasing applied voltages, the transition temperature of the MIT current jump decreases. We find a monoclinic and electronically correlated metal (MCM) phase between the abrupt current jump and the structural phase transition (SPT). After the transition from insulator to metal, a linear increase in current (or conductivity) is shown with temperature until the current becomes a constant maximum value above T_{SPT}=68^oC. The SPT is confirmed by micro-Raman spectroscopy measurements. Optical microscopy analysis reveals the absence of the local current path in micro scale in the VO_2 device. The current uniformly flows throughout the surface of the VO_2 film when the MIT occurs. This device can be used as a programmable critical temperature sensor.Comment: 4 pages, 3 figure