Image quality as a function of unsharp masking band center

Unsharp masking is an image enhancement technique used to obtain a Modulation Transfer Function (MTF) greater than unity within a given spatial frequency band. In unsharp masking, the mask forms a slightly blurred version of the original image. The result is more severe in the high frequency region than at low frequencies. The final image is made by combining the original positive and the blurred negative images. The subjective quality of images resulting from unsharp masking is a function of the frequency response of the human eye. This study evaluates the unsharp masking technique by implementing the Subjective Quality Factor (SQF) criterion

Dynamics simulation of microelectromechanical electrostatic actuator incorporating the squeeze-film damping effect

In this study, the influences of the squeeze-film damping effect on the dynamic behavior of the microelectromechanical electrostatic actuators are investigated by the hybrid numerical scheme comprising the differential transformation method and the finite difference method. There are two types of actuators which including the circular micro-plate and the clamped-clamped micro-beam, relatively. The analyses take account of the axial stress effect, the residual stress and the fringing field effect within the micro actuators and explore the dynamic response of the plate/beam as a function of the magnitude of the AC driving voltage. The effectiveness of a combined DC/AC loading scheme in driving the micro actuators are examined. It is shown that the use of an AC actuating voltage in addition to the DC driving voltage provides an effective means of tuning the dynamic response of the micro actuators. Therefore, the results show that the hybrid method provides an accurate and computationally-efficient means of analyzing the nonlinear behavior of the micro-beam structures used in many of today’s MEMS-based actuator systems

Numerical simulation and analysis of the micro electrostatic device

In general, analysis of the electrostatic device is quite difficult and complicated due to the electrostatic coupling effect and the nonlinear electrostatic force. In this study, a hybrid method (H. M.) for the micro-structure system, which combines the differential transformation method (D. T. M.) and finite difference approximation techniques, is used to overcome the nonlinear electrostatic coupling phenomenon. The differential transformation employed is a transformed function based on the Taylor series that is effective in solving nonlinear problems with fast convergence. First, the natural frequencies of a micro fixed-fixed beam are derived as the solutions to a boundary value problem with prescribed boundary conditions by the differential transformation method. And then the nonlinear governing equation of a micro cantilever beam is solved by the hybrid method. The numerical results of the calculated pull-in voltage and natural frequencies are compared with other literatures using various computational methods and are found to be in good agreement. Overall, the results presented in this study show that the proposed hybrid method, provides an accurate and versatile means of analyzing the complex nonlinear behavior of a micro electrostatic devices

Analysis of nonlinear dynamic behavior and pull-in prediction of micro circular plate actuator

The dynamic behavior of micro circular plate electrostatic devices is not easily analyzed using traditional methods such as perturbation theory or Galerkin approach method due to the complexity of the interactions among the electrostatic coupling effect, the residual stress and the nonlinear electrostatic force. Accordingly, the present study proposes a approach for analyzing the dynamic response of such devices using a hybrid numerical scheme comprising the differential transformation method and the finite difference method. The feasibility of the proposed approach is demonstrated by modeling the dynamic response of a micro circular plate actuated by a DC voltage. The numerical results for the pull-in voltage are found to deviate by no more than 0.27 % from those derived in the literature using various computational methods. Thus, the basic validity of the hybrid numerical scheme is confirmed. Moreover, the effectiveness of a combined DC/AC loading scheme in driving the micro circular actuator is examined. It is shown that the use of an AC actuating voltage in addition to the DC driving voltage provides an effective means of tuning the dynamic response of the micro circular plate

An Ultra Low Power Voltage Regulator for RFID Application

An ultra low power and low voltage regulator for radio-frequency identification (RFID) passive tags is designed and optimized in this thesis. It consists of a low power sub-1V reference voltage generator with temperature and supply voltage ripple compensation, and a low-dropout voltage (LDO) regulator. The circuits are designed in CMOS 65nm technology. The total quiescent current of 63.8nA at 1.5V supply voltage has been achieved using properly sized transistors operating in the subthreshold region. With the low voltage property of transistors operating in subthreshold region the output regulated voltage can easily achieve 1V with load capacity of 50uA. Self-biased current sources are employed and optimized to eliminate the effect of supply voltage variation and to achieve a line regulation of 4.06mV/V. A PMOS pass device with small output resistance is used to reduce the load regulation to 6.57mV/50uA. By utilizing subthreshold properties, the temperature coefficient is reduced to 12.7 and 31ppm/°C for the reference voltage and regulated voltage, respectively. The circuits can operate well from -30°C to 50°C, a typical temperature range of the environment where RFID tags are widely deployed

Effect on Spasticity After Performance of Dynamic-Repeated-Passive Ankle Joint Motion Exercise in Chronic Stroke Patients

Spasticity associated with abnormal muscle tone is a common motor disorder following stroke, and the spastic ankle may affect ambulatory function. The purpose of this study was to investigate the short-term effect of dynamic-repeated-passive ankle movements with weight loading on ambulatory function and spastic hypertonia of chronic stroke patients. In this study, 12 chronic stroke patients with ankle spasticity and inefficient ambulatory ability were enrolled. Stretching of the plantar-flexors of the ankle in the standing position for 15 minutes was performed passively by a constant-speed and electrically powered device. The following evaluations were done before and immediately after the dynamic-repeated-passive ankle movements. Spastic hypertonia was assessed by the Modified Ashworth Scale (MAS; range, 0–4), Achilles tendon reflexes test (DTR; range, 0–4), and ankle clonus (range, 0–5). Improvement in ambulatory ability was determined by the timed up-and-go test (TUG), the 10-minute walking test, and cadence (steps/minute). In addition, subjective experience of the influence of ankle spasticity on ambulation was scored by visual analog scale (VAS). Subjective satisfaction with the therapeutic effect of spasticity reduction was evaluated by a five-point questionnaire (1 = very poor, 2 = poor, 3 = acceptable, 4 = good, 5 = very good). By comparison of the results before and after intervention, these 12 chronic stroke patients presented significant reduction in MAS and VAS for ankle spasticity, the time for TUG and 10-minute walking speed (p < 0.01). The cadence also increased significantly (p < 0.05). In addition, subjective satisfaction with the short-term therapeutic effect was mainly good (ranging from acceptable to very good). In conclusion, 15 minutes of dynamic-repeated-passive ankle joint motion exercise with weight loading in the standing position by this simple constant-speed machine is effective in reducing ankle spasticity and improving ambulatory ability

Evaluation on Higher Education Using Data Envelopment Analysis

The goal of higher education is to provide students an equal opportunity to access their education for success. With significant competition within the peer group, potential students look for quality, flexibility, and affordability in the educational environment. In addition, the relationship between students and the institution involves a concentrated and more specific set of expectations. In order to improve students’ academic performance and fulfill individual needs, universities aim to enhance the quality of students’ learning environment and academic achievements. The higher education system relies on efficient operation and strategic planning to fulfill students’ needs through an internal emphasis on institutional performance improvement. A study on measuring the performance of higher education is presented. The research was focused on four-year and above, public and not-for-profit private universities in the southern region (AL, AR, KY, LA, MS, OK, TN, and TX) of the United States. The data includes 270 universities which were obtained from the Institute of Education Sciences, U.S. Department of Education. This study applied the Data Envelopment Analysis (DEA) approach; the purpose is to use a linear programming model to demonstrate a novel benchmarking process of higher education institutional performance and determine an overall benchmark for institutions within each classified group. From the results, suggestions are provided for the general guidance of planners and decision makers in the higher education system

Note on a Single-Machine Scheduling Problem with Sum of Processing Times Based Learning and Ready Times

In the recent 20 years, scheduling with learning effect has received considerable attention. However, considering the learning effect along with release time is limited. In light of these observations, in this paper, we investigate a single-machine problem with sum of processing times based learning and ready times where the objective is to minimize the makespan. For solving this problem, we build a branch-and-bound algorithm and a heuristic algorithm for the optimal solution and near-optimal solution, respectively. The computational experiments indicate that the branch-and-bound algorithm can perform well the problem instances up to 24 jobs in terms of CPU time and node numbers, and the average error percentage of the proposed heuristic algorithm is less than 0.5%

EVALUATION OF RECEIVING ABILITY OF TEENAGE MALE TABLE TENNIS PLAYERS IN TAIWAN

The purpose of this study was to evaluate the forehand receiving ability of teenage male table tennis players. Thirty-nine male players consist of skill levels from junior to senior high school students and national squads were selected. This assessment involves three tests: basic control, judgment, and match-like condition simulation. We found under the basic control test, the junior high school players performed poorer in downspin and left-side downspin in the aspect of accuracy (

The Effects of Green Energy Production on Farmland: A Case Study in Yunlin County, Taiwan

Taiwan enacted the Act of Renewable Energy in the year 2009 which promotes energy safety, green economy, and a sustainable environment, and with that the government envisages a contribution of photovoltaic energy of up to 20% by the year 2025. In this study we look into the motivation and background of this energy policy, plans for implementation and associated challenges, and its actual consequences for farmland use and farmers. In addition, we take a look into the implementation of mixed-use farmland in which agricultural activity and photovoltaic installations are planned to coexist in order to increase land value and productivity. We furthermore report on some of our findings related to a field survey conducted in Taiwan’s corn chamber of Yunlin County which has been facing a number of socioeconomic challenges