Applied Mechanics and Materials Vol. 793

Abstract: Block Data Transmission Systems (BDTS) are used in high speed wireless communication systems with time dispersive channel characteristics. Since Maximum Likelihood Block Detection (MLBD) requires huge amount of computation, Sphere Detection (SD) technique has been introduced as an alternative. This paper proposes an A_n Lattice Sphere Detection (A_nLSD) technique for detection in block data transmission systems (BDTS). The A_n lattice structure offers more dense constellation points than the customary Z_n lattice in SD technique. Thus, the proposed A_nLSD uses A_n lattice generator matrix as the channel matrix, and uses the Gram matrix which is obtained from the generator matrix as part of the detection process. Simulation results show that the proposed A_nLSD performs very close to the Exhaustive search (ES) using block size of 20 bits. It is also performing better than the other renowned methods tested under a channel with spectral nulls. The proposed A_nLSD technique offers significant reduction in term of objective functions evaluation as compared to the other renowned methods.

Abstract: Optical CDMA (OCDMA) systems have received more attention because CDMA allows many users share the same transmission medium asynchronously and simultaneously with a high level of transmission security. In this paper, we describe the improved performance of the spectrum amplitude coding (SAC) OCDMA system using OFDM technique compare to SCM/SAC-OCDMA system. The theoretical results of proposed system shows that, the new SAC/OCDMA system with OFDM technique provides better performance compare to SCM/OCDMA system based on Random Diagonal Code (RD), the results evaluated based on BER, number of users and weight of code. Thus this system could be one promising solution to the symmetric high capacity access network with high spectral efficiency, reducing the required power and cost effective of broadband access network

Abstract: There will be increasing demand for high confidentiality, integrity, authentication, for widely deployment of the next RFID generation beside that, the focus will be on avoiding encryption algorithms; as these require more complex modulation, to secure communication between RFID’s tags and readers. In this paper, the focus will be on securing the communication channel between tags and readers at the physical layer, rather than to secure the contents of RFIDs data by encryption. The RFID reader initially will communicate with the tag through a narrowband communication and subsequently through broadband communication, by generating ultra wide-band signal using pulse position modulation with time hopped, it can be a novel approach for RFID security as it simplify or eliminate cryptographic requirements with the same security level of existing passive RFIDs, also it allow simultaneous multiple access without-collision, which will enhance the overall RFID systems performance. The design of the system will be shown by modeling the communication, the designing details of the transmitter as well as the receiver, finally showing the simulated results of modulated signal with its specific parameters as well as the receiver performance.

Abstract: This paper describes a small scale energy transfer by using magnetic coil made ​​with enamel coil, which is installed on the transceiver side and function generator and RF power amplifier are installed as source to generated signal, and on the receiving side is using an enamel coil materials as antenna. In this experiment obtained energy as it travels from the transceiver can be received at the receiver side without any media or cable, the principle of electromagnetic fields used in this experiment. Number of coil inductive coupling has been compare. Number of turn 4, efficiency 91 % at 0 cm with 4.55 volt and the lower efficiency 70% at 5 cm with 3.1 volt. And number of turn 8, efficiency 97.8% at 0 cm with 4.89 volt and the lower efficiency 70% at 5 cm with 3.50 volt

Abstract: A low power, cost effective and energy efficient microcontroller (PIC 16F877A) based transceiver model has been presented. The designed model entails a combination of programmable microcontroller and relay circuitry to control the robotic vehicle through transceiver module. The model was simulated in a Mikro C environment, for communication signals from controlling side. The simulation results show an energy efficiency of 73%, with a distance of 20 meters for robotic vehicle. The results are in good agreement with theoretical understandings and show a greater efficiency, with low power consumption and reduced complexity. The simulations are found recurrent with stable findings and deemed compatible for applications.

Abstract: The advance in technology has negatively affected to a home as crime rate is increasing as well as any other emergency case due to lack of awareness on security and safety when a person are on vacation. Overall, the paper presents the design of the security of home against intruders, fire and leakage of gas by alarming the specific person via Short Message Service (SMS) through Global System for Mobile Communication (GSM) modem. The system required the integration of PIC16F877A microcontroller with input and output devices such as GSM module, gas detector, vibration sensor, LDR sensor, keypad and magnetic door lock. The home security system has a special feature which is capable to send an immediate alert message to both homeowner and relevant civil authorities in order to prevent the incidents grow critically. Besides, the security system also provides a door lock security system that required a password entering by using a keypad. Finally, the system is able to send sms to both home owner and the authority bodies has been discussed.

Abstract: Smart homes and environments have been discussed and hyped for many years now, and despite technological advances, future visions and dreams the concept of a smart home remains distant and unfamiliar. People are becoming increasingly more mobile in this fast faced society as has been seen by the number of cell phones in existence. We believe that the home of the future will have the capability of being completely controlled by some remote device using of radio frequency (RF) remote control to controls the home appliances.In this paper we describes a review of radio frequency for home appliances. The scope of this research work is based on comparison between radio frequency controller and infra red controller. The research methodology involved the limitation, specification, bandwidth range between two type controller.Finally the result, will be observe and analyze to obtain better solution in the future.

Abstract: In modern society, more appliances have been presented in a home and office. It comes out a problem that how to manage and control these increasing various appliances efficiently and conveniently so as to achieve more comfortable, security and healthy space at home. This paper presents a new concept of home automation as a solution to save the cost and reduce the cost of material (cable) and also to reduce the voltage drop in the wiring system for a home and office. The result for this paper is based onapplication of the wireless switch (transmitter and receiver) for home appliance such as lighting, fan only that installed at terrace house. A procedure has been developed to predict, study, design, simulate and troubleshooting the RF Remote Switch. This paper also discuss and made a comparison with the current wiring system in terms of cost saving, maintenance and voltage drop.

Abstract: The demand for cooling and air-conditioning is growing due to increasing demand for comfort level and cooling loads. The chilled-water systems (chillers) are one of the energy consuming appliances that consume large amount of energy in buildings. Under these circumstances, energy management system carried out to achieve the objective of using the minimum possible energy, while maintaining the comfort levels and the production rates in factories. This paper proposes an optimal operation for the chillers with the partial load ratio (PLR) and partial storage system (PSS) based on Fuzzy Inference System (FIS). Simulation results are presented to show the effectiveness of technique for energy saving of the Screw Chillers in large building as compared with ON-OFF control system.

Abstract: This study examines the design of heat exchanger made of copper tube for cooling electric vehicle car battery system and the effects of base fluid and nanofluid (as coolants) channeling inside the heat exchanger to increase heat transfer between the compartment of the electric vehicle car and the heat exchanger and comparison between them. The nanofluid (CuO/pure water) was prepared by dispersing a nanoparticle (CuO) in base fluid (pure water). nanofluid (CuO/pure water) with a nominal diameter of 50 nm at volume concentrations (0.27 Vol. %) at batteries’ compartment temperature was used for these investigations. The analysis showed that secondary cooling system by means of nanofluid (CuO/pure water) has advantages in improving the thermal conductivity and heat transfer coefficient, better from base fluid (pure water) also in Nusselt number. This results work on reducing the electric power loss in the form of thermal energy from batteries. This led to increase in the efficiency of the electric vehicle car battery, hence also improved the performance of the EV car and battery lifetime.