Intelligent glove for suppression of resting tremor in Parkinson’s disease

One of the significant symptoms in Parkinson’s disease is resting tremor. Resting tremor occurs when the muscle is relaxed, causing the limb to shake. Rhythmic muscle movement of the patients commonly happens within the range of 4 Hz to 6 Hz. Thus, reducing this type of tremor will help improve patients’ quality of life. In this paper, to suppress resting tremors, an intelligent glove was designed utilizing the concepts of vibrations and gyro effect. A rotating brass disc attached to the glove creates a gyroscopic effect of the smart glove. Therefore, the disc will do their utmost to stay upright and counter any input forces instantaneously by providing the counterforce. A reduction of more than 50 % with the intelligent glove is also shown.Scopu

Estimation and measurement of effective line mobility on a non-deterministic thin plate excited by a piezoelectric patch

This paper derived the expression to estimate the effective line moment mobility of a non-deterministic thin plate under moment excitation by a piezoelectric patch actuator. The piezoelectric patch actuator is assumed to generate purely line moments at each of its edges and regarded as a finite number of point moments acting on an infinite plate, which is achieved by integration method. The theoretical model is validated using MATLAB simulation and compared with experimental measurements on a randomized thin plate. The derived effective line moment mobility managed to closely estimate high-frequency response while cutting significant computational time and resource. Results from this study can be used in many applications ranging from vibration isolation where power transmission between the isolator with an area distribution and its host structure can be determined more accurately, and to design the optimal shunt circuit of a piezoelectric shunt damper for maximum power dissipation in order to reduce vibration of a non-deterministic thin plate

Voltage supply and voltage regulation

A stable voltage supply is important for the proper operation of electronic devices. Stability is characterized by the ability of the voltage output to stay constant and ripplefree regardless of how much load is connected to the circuit. There is a brief discussion on how much inaccuracy is caused by voltage supplies which are prone to voltage fluctuations due to switching phenomenon taking place in the circuit, load fluctuations or temperature change

Improving μ-wire electro-discharge machining operation of polished silicon wafer by conductive coating

Micro-Wire Electro-discharge machining (-WEDM) is a nonconventional machining technology which is extensively used for metal based micro fabrication process. This is a non-contact machining process where material removal is taken place by electro-thermal action. -WEDM process is difficult to be applied for semiconductor material like Silicon (Si). In this paper a new approach is proposed for machining polished Si (p-type, resistivity 1-50 -cm) wafer. In this method, initially Si workpiece is coated with a conductive material (gold for this study) and then -WEDM operation is carried out. Finally, after WEDM operation, the conductive layer is removed from the polished Si substrate without damaging the substrate. WEDM process stability was found to be improved (up to 60 times for certain machining condition) if coated Si wafer is used as compared to uncoated Si workpiece. Material removal rate was also found to be increased by a good margin (~ 100% maximum) for coated Si wafer. Overall this new method of -WEDM operation of polished Si wafer has been found to be more efficient and useful

Correction to: Towards achieving nanofinish on silicon (Si) wafer by μ-wire electro-discharge machining

[No abstract available]This work was supported by the Fundamental Research Grant (FRGS/1/2014/TK01/UIAM/02/2) sponsored by the Ministry of Higher Education Malaysia. Authors also acknowledge the research support provided by the International Islamic University Malaysia

Dynamic effects of piezoelectric patch actuators on vibrational response of non-deterministic structures: modelling and simulations

Many engineering systems such as aircraft and automotive are considered built-up structures, fabricated from components that are classi fi ed as deterministic subsystems (DS) and non-deterministic subsystems (Non-DS). The response of Non-DS is sensitive to minor details of material properties, geometry, connections and damping distribution; therefore create problems in vibration control. Hence, the response of Non-DS is estimated using statistical modelling technique such as sta- tistical energy analysis (SEA), in which any external input to the subsystem must be represented in terms of power input. In this research, ensemble average of power delivered by a piezoelectric (PZT) patch actuator to a simply-supported plate when subjected to structural uncertainties is studied using Lagrangian method and obtained by Monte-Carlo simulation. The effects of size and location of the PZT patch actuators on the power delivered to the plate are investigated. It is found that changing the patch location on the structure will not affect the average power sup- plied by the patch while changing the patch size will change the power magnitude proportionally but with some variations at higher frequency

FRGS15-165-0406: MATHEMATICAL ANALYSIS TO ESTIMATE OPTIMAL SHUNT IMPEDANCE FOR PIEZOELECTRIC TRANSDUCER TO MAXIMIZE VIBRATION ENERGY DISSIPATION IN NON-DETERMINISTIC SUB-SYSTEMS

Engineering systems such as aircrafts, ships and automotive are built-up structures fabricated from many components that can be classified as deterministic substructure (DS) and non-deterministic substructure (Non-DS). Non-DSs are subjected to high-frequency vibration which produced response that cannot be described mathematically using deterministic method. This makes vibration energy harvesting tricky due to the combined modal response which produce no visible distinct peaks. Piezoelectric (PZT) transducer connected to a shunt circuit is an attractive choice to harvest vibration energy from a Non-DS. Using Hybrid modelling equation, the impedance of the circuit to be attached to the Non-DS needs to be complex conjugate of the impedance faced by the Non-DS at its connection point. The shunt circuit of the PZT shunt harvester is designed such that the impedance is complex conjugate of its inherent capacitance parallel with impedance faced by the host structure at the connection area. In the first part of this research, the impedance faced by the Non-DS at the connection area is estimated using effective line mobility of an infinite thin plate under moment excitation by a square PZT patch using double integration of the infinite mobility which resulted to a hypergeometric function. The analytical model is compared with the average response of a randomized finite thin plate via Monte Carlo simulation which managed to significantly cut computational time to ~40 times shorter compared to using the finite method. Using findings from this part, the implementation of the designed shunt circuit using electronic components is carried out. One possible circuit configuration that closely resembles the theoretical impedance derived is realized by application of two negative impedance converters (NICs) utilizing op-amps, in order to replicate the negative capacitance, C and negative RL in series

HUBUNGAN ANTARA KUAT TEKAN DAN ABSORPSI BETON NORMAL

Kurangnya kesadaran masyarakat dan para kontraktor awam terhadap absorpsibeton. Dimana pembangunan rumah tinggal hingga kolam renang yang dibangunberada di lantai atas pada suatu bangunan dan rawan rembes. Beton dalam kondisinormal tidak kedap air dan berhubungan dengan absorpsi, penelitian ini melakukanpercobaan dengan berbagai mutu beton, yaitu K175, K225, dan K250, telah diujidalam rangkaian eksperimen ini. Selain itu, penelitian juga melibatkan variasidimensi dengan tinggi beton 10 cm dan diameter 15cm. Hasil analisis menunjukkanbahwa terdapat perbedaan signifikan dalam nilai absorpsi, dengan rata-rata absorpsipada K-175 sebesar 3,99 mm, K-225 sebesar 2,93 mm, dan K-250 sebesar 2,63 mm.Selanjutnya, setelah memasuki fase masa jenuh, terlihat bahwa terjadi perlambatanpada proses infiltrasi, menandakan tahap di mana air mulai masuk ke dalam pori-pori benda uji melalui proses kapiler. Data yang diperoleh dari penelitian inimenunjukkan bahwa semakin tinggi mutu beton, maka nilai rerata absorpsinyacenderung semakin rendah. Dengan demikian, dapat disimpulkan bahwa kualitasbeton berpengaruh signifikan terhadap tingkat absorpsi yang terjadi pada materialtersebut. Kata Kunci : absorpsi, mutu beton normal, infiltras

Machine condition monitoring and fault diagnosis using spectral analysis techniques

There is need to continuously monitor the conditions of complex, expensive and process-critical machinery in order to detect its incipient breakdown as well as to ensure its high performance and operating safety. Depending on the application, several techniques are available for monitoring the condition of a machine. Vibration monitoring of rotating machinery is considered in this paper so as develop a selfdiagnosis tool for monitoring machines’ conditions. To achieve this a vibration fault simulation rig (VFSR) is designed and constructed so as to simulate and analyze some of the most common vibration signals encountered in rotating machinery. Vibration data are collected from the piezoelectric accelerometers placed at locations that provide rigid vibration transmission to them. Both normal and fault signals are analyzed using the singular value decomposition (SVD) algorithm so as to compute the parameters of the auto regressive moving average (ARMA) models. Machine condition monitoring is then based on the AR or ARMA spectra so as to overcome some of the limitations of the fast Fourier transform (FFT) techniques. Furthermore the estimated AR model parameters and the distribution of the singular values can be used in conjunction with the spectral peaks in making comparison between healthy and faulty conditions. Different fault conditions have been successfully simulated and analyzed using the VFSR in this paper. Results of analysis clearly indicate that this method of analysis can be further developed and used for self-diagnosis, predictive maintenance and intelligent-based monitoring

Active vibration control using piezoelectric actuator: implementation of ant colony optimization technique in virtual experimentation

This paper demonstrates the implementation of virtual experiment using COMSOL Mutiphysics – MATLAB integration for optimization in active vibration control system. The benchmark model is a simply supported thin plate excited and attenuated by two piezoelectric patches. Instead of using equation-based modeling to represent the system, optimization of the sensor-actuator location and controller gains are conducted directly on the finite element model in COMSOL Multiphysics via Livelink for MATLAB function. The optimization is based on the average energy reduction across a frequency range between 11 Hz to 50 Hz, which covers the first three modes. It is found that the maximum attenuation achieved is 68.31% using optimal values of ensor -actuator location and controller gains