Tung-Jung Chan

Development of a universal contactless charger for handheld devices

The purpose of this paper is to design and implement a universal contactless charger for handheld device by means of electromagnetic coupling induction related applications. Through coil coupling induction, contactless power transmission system is able to supply power to the secondary side with high safety and low repair rate features. However, this paper discusses PCB (Printed Circuit Board) and a spiral-type induction coil used as a coupling induction device for the contactless charging system. With the design proposed in this paper, the size of regular counting induction devices can be greatly reduced. By changing the geometric shape and location of coupling coil, the relationship and changing conditions of respective parameters and coupling coefficients can be obtained and analyzed to serve as references for future designs. Therefore, in conjunction with theoretic and actual design guidelines, sequential studies will be conducted. Finally, contactless mobile phone charger with rated 4.2V, 800 mA is completed to validate its function.

Study of applying contactless power transmission system to battery charge

Contactless power transmission system with the advantages of safety and convenience has been applied to daily supplies. However, general contactless power transmission charger cannot control the current cause there is no charge controller in secondary side and the severe limitation between primary and secondary sides of the battery charger cause difficulty to design. This study provides the charge controller with half-bridge inverter and E-Type core as coupling converter in primary side; A Zeta DC converter is utilized to achieve the outcome of charge with constant voltage and to increase the charging distance between primary and secondary sides. To verify the feasibility of contactless power transmission system, the study completes the contactless charger with the output power of 30W. The result shows that the overall system efficiency is 57.8 % with 150 V/ 0.35A input and 15.2 V/2 A output.

Gender activities in mobile internet

With the rapid growth of demands of mobile phones, and the advent of third generation technology, accessing Internet via mobile phones is going to become the most promising trend. However, the success of mobile Internet (m-Internet) implementation depends on whether or not individuals are willing to adopt this new technology. Thus, it is necessary for practitioners and academics to explore the factors influencing the acceptance of m-Internet by individuals. By analyzing the data, results indicate that that performance expectancy, effort expectancy, social influence, perceived value and palm-sized computer self-efficacy were significant determinants of behavioural intention to use m-Internet. We also found that gender activities moderate the effects of performance expectancy, effort expectancy and palm-sized computer self-efficacy on m-Internet usage intention. These findings offer several important implications for m-Internet acceptance, in terms of both research and practice.

Performance of an Energy Efficient Routing Scheme for Cluster-based Wireless Sensor Networks

This paper proposes a novel energy efficient data clustering scheme to improve energy efficiency for cluster-based wireless sensor networks (WSNs). In order to reduce the energy dissipation of transmitting sensing data at each sensor, the fixed clustering algorithm uniformly divides the sensing area into clusters where the cluster head is deployed to the centered of the cluster area. Moreover, to perform energy efficient grid clustering (EEGC), the nodes take turns to be cluster head. Simulation results show that proposed EEGC definitely reduces the energy consumption of the sensors and prolongs network lifetime to be longer than LEACH for both life rate=50% and 70% . Moreover, the total transmission data of EEGC is more 60% than LEACH scheme.

A Multi-Criteria Image Quality Evaluation Scheme

It is difficult to objectively and quantitatively judge image quality by a single criterion, such as contrast. In general, excessive contrast enhancement easily leads to a loss of image quality. Thus, it easily gives a wrong evaluation to rank image quality according to contrast values. In order to achieve a consistent result with human vision perception, balancing multi-criteria will be a feasible approach. Therefore, we propose a multi-criteria image quality evaluation scheme for ranking seven existing contrast enhancement methods. The scheme applies four criteria to a newly proposed way of computing a grey relational grade (GRGd), called the consistent grey relational grade (CGRGd). Experimental results show that our proposed CGRGd do provides a very effective mechanism to choose the best method for a specific purpose.

A Forwarding Station Integrated with Optimal Cluster Number Selection in Wireless Sensor Networks

In wireless sensor networks, power consumption is the most important issue. That is wireless sensors are normally deployed into unattended places where power of sensors is hard to be charged. Indeed, the network lifetime of wireless sensor networks equipped with city power or deployed into attended place is much longer than those wireless sensors equipped with batteries. In general, wireless sensor nodes are connected together and become a network after deployed into certain places. With the certain range places that wireless senor nodes deployed into, finding the optimal clusters can increase the entire network lifetime. Also, adding the forwarding station extends the network lifetime. Therefore, this paper proposes the integration of both the forwarding station and optimal clusters in ad-hoc wireless sensor networks. Simulation results show that the entire network lifetime proposed is extended in this paper compared to both optimal cluster number selection and normal forwarding station.

The Battery Management for Power Supply System

The battery management system for the micro air vehicle discussed in this paper provides the better efficient control for evaluation of power system. This paper uses the management strategy to avoid the lose caused by micro air vehicle collapse and resulted from error in current capacity control. In order to avoid failure of flight mission, calculation and accurate the control of current, the micro air vehicle can be provided with longer flight range, sufficient usage of battery and appropriate feedback of system operation status. Operator then can be provided with all kinds of information in more clear status. A system in the micro air vehicle has to achieve the goal such as lower noise, longer-range flight, quicker response and accuracy. Moreover, this paper discusses the combination requirement and utilizes the power supply and micro components of transmit system available in the market to carry out optimal combination. We use the battery, motor, propeller, transmitter, receiver, and electrical transmission to carry out the better combination for the power supply system of UAV (Unmanned Aerial Vehicle).

A Fuzzified Neural Fuzzy Inference Network that Learns from Linguistic Information

A fuzzified Takagi-Sugeno-Kang (TSK)-type neural fuzzy inference network (FTNFIN) for handling linguistic information is proposed in this paper. The inputs and outputs of FTNFIN may be fuzzy numbers with any shapes. The CC -cut technique is used in input fuzzification and consequent part computation, which enables the network to handle linguistic information. There are no rules in FTNFIN initially since they are constructed on-line by concurrent structure and parameter learning. The network has been applied to the learning of fuzzy input and output data, and good simulation results are achieved.