Zeeshan Siddiqui

A New Low SAR Antenna Structure for Wireless Handset Applications

This paper proposes a new mobile handset antenna structure to reduce the value of the speciflc absorption rate (SAR). The antenna is based on the PIFA structure and operates at dual-bands of 0.9GHz and 1.8GHz. The chassis current is reduced using a metallic shim-layer inserted between the patch and chassis. This shim-layer is connected to the handset chassis through posts whose number and positions are determined using optimization techniques. Sidewalls are attached to increase the gain of the antenna and reduce the radiation towards human head. Simulations in the cheek mode show that the SAR reduction factor (SRF) of the proposed structure averaged over 10-g is more than 75% at 0.9GHz and 46% at 1.8GHz. The SRF values obtained using simulations and measurements are found to be better than 51% and 76% at 0.9GHz and 1.8GHz, respectively.

A Common Information Exchange Model for Multiple C4I Architectures

Information exchange among different architectures has been a massive challenge from the last three decades. Difficulty usually arises when an ideal model that deals with the precise exchange of data among different architectures is needed. Considering the case of military architecture frameworks on a common battle field, exchange of efficient and most precise information is the key for a perfect decision. Data exchange within different defense nodes is still a challenge. In this paper, we propose a general reference model to integrate different Command Control Communication Computer & Intelligent (C4I) systems operating under different defense forces of different coalition groups involved in a common-battle-field. The purpose of this study is to introduce a general reference model utilizing W3C Semantic Web Specification technique for meta-data models based on a software engineering method to develop and maintain usable and precise domain ontology in order to overcome interoperability issues of different C4I architectures exchanging information on a common battle field.

Qualified Analysis b/w ESB(s) Using Analytical Hierarchy Process (AHP) Method

This research study stress upon the qualified or comparative analysis between commercial and non-commercial Enterprise Service Buses (ESB) for large-scale organizations. We have used Multi Criteria Decision Analysis (MCDA) method known as Analytical Hierarchy Process (AHP) based on three criteria i.e. Information Security, Interoperability & High availability. Many comparative analysis reports and papers are available having proven results of comparing non-commercial ESB(s), however, very few reports were found having performed their analysis on commercial ESB(s). We have performed this analysis on the basis of tabular and mathematical proofs by comparing commercially known ESB i.e. Oracle ESB with two non-commercial yet very famous ESB(s) i.e. Mule & Fuse. This research analysis will motivate decision makers to choose the best rated ESB on the basis of our criteria. To achieve our objective we have presented the problem as hierarchy, established the priorities, criteria and performed mathematical computing to prove our analysis.

Antipodal Vivaldi antenna for hyperthermia treatment

An ultra-wideband (UWB) antipodal Vivaldi antenna is developed for hyperthermia treatment of tumors in the human head. The proposed antenna has overall size 82×94×1.6mm. The performance of the antenna is tested in four background material air, oil, water and simulated brain liquid. The antenna is designed to operate in UWB range supporting low frequency range to satisfy wave penetration in the brain. Higher frequency ranges allow the localization of microwave energy in the tumor location. Simulated and measured reflection parameters of the proposed structure are evaluated. A phantom model is used to investigate a hyperthermia treatment. Design parameters are optimized to focus the energy inside the tumor location, by optimizing the phased and amplitude of the excitation of each element of an array. Results are presented, showing the effect of the optimization process on the distribution of the specific absorption rate SAR inside the phantom.

Optimization of UWB applicator for hyperthermia treatment of human head

An Ultra-Wideband (UWB) applicator for hyperthermia treatment of human head is developed. The system depends on the design of an array of small foot-print horn elements to allow the construction of large sized-array to surround the human-head. A waveform optimization tool is developed based on genetic algorithms to localize the energy into the tumor location. Computational analysis is performed using CST and experimental measurements are obtained using DASY5 system. Results of the field and SAR image distributions within the human head phantom illustrate the promising performance of this applicator design.

Ultra-wideband applicator for brain-tumor ablation and imaging system

An Ultra-Wideband (UWB) applicator for microwave imaging and hyperthermia or thermal ablation of brain tumors is developed. The system depends on the design of a MIMO array of UWB applicator to be mounted on the head. The applicator is based upon Vivaldi antenna structure, which is designed to increase the power radiated toward the human head to enhance power absorption within the tumor region. Based on the traveling-wave performance, the antenna radiates in the end fire beam, and each applicator touches the head in a slim area of the size of the substrate thickness (1.57 mm) and the antenna width (64 mm). This structure is thus attractive for use as small foot-print elements that allow the construction of large sized-array to surround the human-head. Analysis is performed using the IE3D and SEMCAD-X simulators, and the S-parameters illustrate the UWB characteristics of the antenna. Results of the field and SAR image distributions within the human head illustrate the promising performance of this applicator design.

A novel low SAR PIFA for mobile terminal

This paper proposes a novel low SAR PIFA structure to reduce exposure of the human head to mobile-set antenna radiation. Dual-band PIFA structures operating at 0.9 GHz and 1.8 GHz bands are considered. SAR is decreased by reducing the back-radiation coming from the patch and the ground plane. This SAR reduction is accomplished by inserting a thin metallic layer between the patch and the ground plane to reduce the current flowing in the ground plane. This layer is connected to the ground plane through few posts located at selected optimum positions. Additionally, three vertical sidewalls are used to reduce radiation from the patch to the human head. Results show that the proposed structure can reduce SAR by up to 76%.

Cryptanalysis and improvement of ‘a secure authentication scheme for telecare medical information system’ with nonce verification

In 2009, Xu et al. presented an improved smartcard based authentication scheme while using a security model previously applied by Bellare et al. to prove the security of their authentication methods. Later on, in 2012, Wu et al. pointed out number of authentication attacks in Xu et al. scheme. To address these issues, Wu et al. presented a Smartcard based Two-Factor Authentication (2FA) scheme for Telecare Medical Information System (TMIS) facility. In this study, we prove that authentication scheme of Wu et al. is still vulnerable to impersonation attack, offline password guessing attack, forgery attack and many other attacks. Moreover, number of performance and verification issues are also outlined in the authentication scheme of Wu et al. To overcome these issues, an improved and enhanced 3FA Smartphone based authentication method is proposed on a Cloud Computing environment. The proposed scheme is further corroborated using Burrows-Abadi-Needham logic (BAN logic) nonce verification. The detailed BAN logic verification and further security analysis shows that the proposed authentication protocol is highly reliable and secure in terms of message verifications, message freshness and trustworthiness of its origin. Moreover, the comparative security, performance and feature analysis shows that the proposed work yields an even more improved and enhanced authentication framework as compared to Wu et al. authentication scheme.

A secure framework for digital Quran certification

This paper presents a digital Quran certification framework by utilizing modern digital authentication and certification techniques to certify and authenticate digital Quran applications available in multimedia format. A certification authority and a religious panel scrutinize the certification process and upon fulfillment of all the requirements, a digital certificate is issued to the digital Quran application. A general consumer of the service can easily verify the issued digital certificate in an online manner. The presented framework aims at diminishing the chances of modifying digital contents of the holy book for its consumers belief and trust.

A compact antenna for microwave imaging and hyperthermia treatment of brain tumor

This paper presents a design of a small size antenna in the L-band for applications of microwave hyperthermia treatment and microwave imaging of the human head. The design is intended to provide an increase of the power radiated toward the human and concentrate the specific absorption rate (SAR) values in the tumor tissue. Size reduction is achieved here by adding a high dielectric layer just above the antenna, and the best suitable material for this application is found to be the fresh water. The design depends on a short circuit triangular slotted shaped on a thick foam substrate to enhance its bandwidth. Analysis is performed using the IE3D and SEMCAD-X simulators, and the obtained overall antenna size is 40×40×14 mm3. The resonance frequency in air is 2.35 GHz at free space, which is reduced near the head to 1.4 GHz, using a 5-mm water layer pad. Simulation analysis is provided of the SAR patterns associated with this antenna.