Engineering Commons^™

Ultra-Thin Super High Frequency Two-Port Aln Contour-Mode Resonators And Filters, Matteo Rinaldi, Chiara Zuniga, Chengjie Zuo, Gianluca Piazza

Matteo Rinaldi

This paper reports on the demonstration of a new class of ultra-thin (250 nm thick) Super High Frequency (SHF) AlN piezoelectric two-port resonators and filters. A thickness field excitation scheme was employed to excite a higher order contour extensional mode of vibration in an AlN nano plate (250 nm thick) above 3 GHz and synthesize a 1.96 GHz narrow-bandwidth channel-select filter. The devices of this work are able to operate over a frequency range from 1.9 to 3.5 GHz and are employed to synthesize the highest frequency MEMS filter based on electrically self-coupled AlN contour-mode resonators. Very narrow bandwidth (~ …

Power Handling And Related Frequency Scaling Advantages In Piezoelectric Aln Contour-Mode Mems Resonators, Chengjie Zuo, Matteo Rinaldi, Gianluca Piazza

Matteo Rinaldi

This paper reports on the analytical modeling and experimental verification of the mechanically-limited power handling and nonlinearity in piezoelectric aluminum nitride (AlN) contour-mode resonators (CMR) having different electrode configurations (thickness field excitation, lateral field excitation, one-port and two-port configurations) and operating at different frequencies (177-3047 MHz). Despite its simplicity, the one-dimensional analytical model fits the experimental behavior of AlN CMRs in terms of power handling capabilities. The model and experiment also confirm the advantage of scaling (i.e. miniaturizing) the AlN CMRs to higher frequencies at which higher critical power density can be more easily attained up to values in excess …

Towards Real Energy Economics: Energy Policy Driven By Life-Cycle Carbon Emission, R. Kenny, C. Law, Joshua M. Pearce

Joshua M. Pearce

Modeling And Computer Simulation Of Fault Calculations For Transmission Lines, Dr. Adel A. Elbaset

Dr. Adel A. Elbaset

Calculation of transmission line faults has a fundamental importance in the fault detection, classification, and location determination of faults in transmission line. This paper presents a proposed computer program based on Matlab software to calculate all ten types of shunt faults that may occur in a transmission line. Various fault scenarios (fault types, fault locations and fault impedance) are considered in this paper. The inputs of the proposed program are line length, source voltage, positive, negative and zero sequence for source impedance, line charging, and transmission line impedance. The output of the algorithm is used to train an artificial intelligence …

Comparative Evaluation Of Pid Voltage Mode, Pi Current Mode, Fuzzy And Pwm Based Sliding Mode Control For Dc-Dc Converters, Omar Ellabban, Joeri Van Mierlo

Omar Ellabban

This paper presents a comparison between the application of four control techniques in DC-DC converters. PID voltage mode (PID-VM), PI current mode (PI-CM), fuzzy, and PWM based sliding mode (SM) controllers are applied to buck converter. The design procedures of controllers are reviewed. The dynamic performance of these controllers under star-up, steady state, input voltage variation, load current disturbances and EMI spectrum are presented and compared.

Stability Analysis Of A Unified Power Flow Controller, Omar H. Abdalla, Mohamed A. E. Ghazy, Lotfy M. Lotfy, Nermeen A. M. Hassan

Omar H. Abdalla

The paper concerns with stability analysis of a Unified Power Flow Controller (UPFC). A nonlinear model is described in the abc-reference frame and then transformed into the dq0-reference frame. The model includes shunt and series compensators of the UPFC. Stability analysis is presented first in a three-dimensional space of system parameters. A linearized model is obtained in state-space form to be used in small-signal stability studies. Effects of system parameters on stability are investigated using eigenvalue analysis. These include resistance, reactance, and modulation indices of the shunt and series components of the UPFC. Simulation results show that the stability of …

Should Tortuosity Still Be Used In Upscaling?, Francisco J. Valdes-Parada, Mark L. Porter, Brian D. Wood

Francisco J. Valdes-Parada

The concept of tortuosity is an integral part of models that describe trans- port in multiscale systems. Traditionally, tortuosity is de#12;ned as the ratio of an e#11;ective path length to the shortest path length in a representative sample of the porous medium microstructure. While the latter can be unambiguously speci#12;ed, the same is not true for the e#11;ective path length, since it changes from one type of transport to another. Consequently, it is possible to have di#11;erent tortuosity values for di#11;erent transport processes taking place in the same system. In order to avoid running into unclear interpretations, we pro- pose …

Smes And Virtual R&D Teams: A Motive Channel For Relationship Between Smes, Nader Ale Ebrahim, Shamsuddin Ahmed, Zahari Taha

Nader Ale Ebrahim

This paper explores potential advantages and barriers of virtual teams toward making an interrelation between small and medium-sized firms (SMEs) with a comprehensive review on different aspects of virtual teams in SMEs based on authentic and reputed publications. The purpose of the state-of-the-art literature review is to provide an overview of what is known about the structure and dynamics of virtual collaboration in SMEs which they are the back bone of the world business. This study seeks to address some of the advantages of virtual R&D team in the existing extensive literature on the increase SMEs interrelations. Besides of identify …

Location Based Services - A Bridge Too Far For Data Linkage And Behaviour Under Security And Privacy Concerns?, Marcus R. Wigan

Marcus R Wigan

Location-based services (LBS) are dependent on a knowledge of a real time location, knowledge of the environment, and integrated with communications. An ideal specification for travel data collection. LBS has become pervasive very swiftly, but the implications are not yet widely recognised. The addition of realtime information, response and service providers to the now familiar combination of GPS, and data recording is the focus of the present paper. The business development path to LBS is outlined, and the implications for data gathering, matching and response considered. The privacy and surveillance aspects are of varying sensitivity in different cultures, even within …

Contrast Measure-Based Automated Regularization Parameter Selection For Radar Image Restoration, Cher Hau Seng, Abdesselam Bouzerdoum, Son Lam Phung

Cher Hau Seng

Images formed by acquisition devices are usually corrupted by noise and other interferences. Hence, regularization methods have been introduced to restore the degraded images and obtain solutions that are stable in the presence of perturbations. While the regularization parameter is crucial to the characteristics of the restoration, most existing selection methods either require memory-intensive computation or prior knowledge of the noise [1]. Moreover, the use of a small regularization parameter will produce a restoration that is dominated by large, high frequency noise components, whereas large regularization parameter imposes greater importance on the regularizer, causing important information to be lost. Therefore, …

Determinants Of Foreign Direct Investment In Iran: An Empirical Study Using Structural Equation Modeling, Ahmad Jafarnejad, Arash Golnam, Nader Ale Ebrahim

Nader Ale Ebrahim

This paper examines the determinants of foreign direct investment (FDI) in Iran by applying the structural equation modelling (SEM). Using the annual time series data for the 1991-2006 period, two models were developed. In the first model the correlation between 12 determining factors and FDI in Iran were analyzed and in the second model the 12 factors were fit into five categories of determinants namely: Business, Economic, Infrastructural, Oil and Science and Technology and the impact of each of the mentioned groups of factors was investigated. The results derived through the first model indicated that openness of trade and Gross …

Is Extended Volume Of External Beam Irradiation Beneficial In Post-Esophagectomy High Risk Patients Receiving Combined Chemoradiation Therapy?, E. Yu, A. R. Dar, R. Ash, G. Videtic, P. Truong, L. Stitt, A. Tomiak, M. Vincent, R. Malthaner, I. Craig, E. Brecevic, W. Kocha, R. Inculet, M. Lefcoe

Edward Yu

OBJECTIVE: To assess the value of extended volume irradiation with anastomotic coverage in high risk resected esophageal cancer patients. METHOD: A retrospective study was undertaken at LRCC from 1989-1999 for high risk resected esophageal cancer patients. Adjuvant treatments consisted of 4 cycles of chemotherapy (epirubicin/fluorouracil/cisplatin or cisplatin/fluorouracil), and local regional irradiation with or without coverage of the anastomotic site. Radiation dose ranged from 45-60Gy at 1.8-2.0 Gy/fraction given with initial anterior-posterior/posterior-anterior arrangement with either extended (with anastomotic coverage) or small (without anastomotic coverage) field followed by oblique fields for boost. RESULT: One hundred eighty-eight charts were reviewed. Seventy-two patients were …

Robot Assisted Ultrasound Imaged Guided Interstitial Lung Brachytherapy In A Porcine Model, Richard A. Malthaner, Edward Yu, Jerry J. Battista, Chris Blake, Donal Downey, Aaron Fenster

Edward Yu

We set out to see if permanent interstitial brachytherapy seeds could be safely and reproducibly inserted thoracoscopicaly with the ZEUS Robotic system and intraoperative ultrasound into in-vivo porcine lungs.

Evaluation Of Intra-And Inter-Fraction Motion In Breast Radiotherapy Using Electronic Portal Imaging Cine Loops, Chrison Lee, Edward Yu, Tomas Kron

Edward Yu

Parallel tangent breast irradiation is commonly used postbreast conservation surgery for early breast cancer patient without lymph node involvement to improve local disease control. Intra-fractional and inter-fractional variabilities are often presented in daily treatment setup. The present pilot study used Electronic Portal Imaging (EPI) to evaluate intra-and inter-fraction motion in patients undergoing simple breast tangent radiotherapy.

Design And Characterization Of A 1-Watt Driver Amplifier For Wireless Infrastructure, Chin-Leong Lim

Chin-Leong Lim

Variable gain amplifiers (VGA) find application in RF systems wherever the signal amplitude must be varied in reaction to a changing environment. Transmitters' driver stage utilize VGAs to conserve power under good propagation conditions and to minimize interference to adjacent sites. Cellular base-station receivers use VGAs in the 2nd/3rd stage LNA to prevent mixer/DAC overloading. Commercially available L-band VGA devices require 14 to 19 external components and have modest linearity-to-power consumption ratio (OIP3 / Pdc). To achieve the industry's lowest component count and best linearity-to-power ratio, we developed a highly integrated VGA module from 0.25 x 3900 um enhancement-mode Pseudomorphic …

Creating Short-Term Stockmarket Trading Strategies Using Artificial Neural Networks: A Case Study, Bruce J. Vanstone, Tobias Hahn

Tobias Hahn

Developing short-term stockmarket trading systems is a complex process, as there is a great deal of random noise present in the time series data of individual securities. The primary difficulty in training neural networks to identify return expectations is to find variables to help identify the signal present in the data. In this paper, the authors follow the previously published Vanstone and Finnie methodology. They develop a successful neural network, and demonstrate its effectiveness as the core element of a financially viable trading system.

Key Performance Indicators Of A Transmission System, Omar H. Abdalla, Masoud Awlad-Thani, Mohamed Al-Wardi, Khalfan Al-Qaidi, Saqar Al-Farsi, Ibrahim Al-Balushi, Saeed Al-Mahdhoori

Omar H. Abdalla

The paper concerns with formulae and calculations of a selected group of Key Performance Indicators (KPIs) for the main electricity transmission system in Oman. These include the following service quality, reliability, security, and financial indicators [1]: &#; System Average Interruption Frequency Index (SAIFI) &#; System Average Interruption Duration Index (SAID) &#; Customer Average Interruption Duration Index (CAIDI) &#; Average Interruption Time (AIT) &#; Overhead Lines Maintenance Cost Index (OHLMCI) &#; Substation Maintenance Cost Index (SSMCI) Results of the main transmission grid in Oman, over the last 3 years, are presented. The results are useful in indicating trends of the KPIs …

Hypothetical Thermodynamic Properties. Subcooled Vaporization Enthalpies And Vapor Pressures Of Polyaromatic Heterocycles And Related Compounds

James Chickos

No abstract provided.

Absolute Nitrogen Atom Density Measurements By Two-Photon Laser-Induced Fluorescence Spectroscopy In Atmospheric Pressure Dielectric Barrier Discharges Of Pure Nitrogen, Et-Touhami Es-Sebbar, Christian Sarra-Bournet, Nicolas Naudé, Françoise Massines, Nicolas Gherardi

Dr. Et-touhami Es-sebbar

In this paper, two-photon absorption laser induced fluorescence spectroscopy is used to follow the nitrogen atom density in flowing dielectric barrier discharges fed with pure nitrogen and operating at atmospheric pressure. Two different dielectric barrier discharge regimes are investigated: the Townsend regime, which is homogeneous although operating at atmospheric pressure, and the more common filamentary regime. In both regimes, densities as high as 3x1014 /cm3 are detected. However, the N atoms kinetic formation depends on the discharge regime. The saturation level is reached more rapidly with a filamentary discharge. For a given discharge regime, the N atom density depends strongly …

Contributions To The Development Of The S.E.T.U.P. (Experimental And Theoretical Simulations Useful For Planetology) Project, E. Arzoumanian, C. Romanzin, M-C. Gazeau, Et. Es-Sebbar, A. Jolly, S. Perrier, Y. Benilan

Dr. Et-touhami Es-sebbar

No abstract provided.

Multiwavelength Studies For Titan's Atmospheric Composition Analysis, Y. Benilan, Et. Es-Sebbar, N. Fray, M-C. Gazeau, A. Jolly, M. Schwell, J. Guillemin

Dr. Et-touhami Es-sebbar

Titan's atmosphere mainly made of nitrogen and methane is rich in organic molecules. Hydrocarbons are formed from the photolytic dissociation of CH4 and nitriles are created by dissociation of N2 followed by reactions with hydrocarbons. In order to understand the physicochemical mechanisms responsible for the evolution of Titan's atmosphere, photochemical models are built. The latter need constrains for vertical profiles of organic compounds from the high thermosphere down to the low stratosphere as well as photodissociation rates. Those profiles over the entire atmosphere can be retrieved from Cassini observations, in particular by limb sounding, coupling infrared and ultraviolet spectroscopy. However, …

A Service Choice Model For Optimizing Taxi Service Delivery, Shih-Fen Cheng, Xin Qu

Shih-Fen CHENG

Taxi service has undergone radical revamp in recent years. In particular, significant investments in communication system and GPS devices have improved quality of taxi services through better dispatches. In this paper, we propose to leverage on such infrastructure and build a service choice model that helps individual drivers in deciding whether to serve a specific taxi stand or not. We demonstrate the value of our model by applying it to a real-world scenario. We also highlight interesting new potential approaches that could significantly improve the quality of taxi services.

Effect Of External Energy On Atomic, Crystalline And Powder Characteristics Of Antimony And Bismuth Powders, Mahendra Kumar Trivedi, Vikram V. Dabhade, Rama Mohan Tallapragada

Mahendra Kumar Trivedi

Vuv Photostability Of Prebiotic Species, M. Schwell, Y. Bénilan, M.-C. Gazeau, N. Fray, A. Jolly, Et. Es-Sebbar, N. Champion, S. Leach, H. W Jochims, H. Baumgärtel, E. Rühl

Dr. Et-touhami Es-sebbar

No abstract provided.

S.E.T.U.P. Experimental And Theoretical Simulations Useful For Planetology- Related Studies In The Frame Of A Program Of Titan’S Atmosphere Laboratory Simulations, M.-C. Gazeau, Et. Es-Sebbar, E. Arzoumanian, C. Romanzin, A. Jolly, S. Perrier, Y. Bénilan

Dr. Et-touhami Es-sebbar

No abstract provided.

Utilization Of Virtual Globes For Open Source Industrial Symbiosis, William Doyle, Joshua M. Pearce

Joshua M. Pearce

User Security Behavior On Wireless Networks: An Empirical Study, Tim Chenoweth, Robert Minch, Sharon Tabor

Robert P. Minch

Wireless networks are rapidly becoming ubiquitous but are often insecure and leave users responsible for their own security. We empirically study whether users are successfully securing their client computers when using wireless networks. Automated techniques are used that scan users' machines after they associate with a university wireless network. This determines whether a firewall is being used and what TCP ports are open. Results show that over 9% of 3,331 unique computers scanned were not using a properly configured firewall. In addition, almost 9% had at least one TCP port open, with almost 6% having open ports with significant security …

An Exploratory Study Of Hypermedia Support For Problem Decomposition, Robert P. Minch, Gary I. Green

Robert P. Minch

Empirical hypermedia research has concentrated on usability rather than utility, and the research on utility has focused on information access as opposed to problem solving and decision making in organizations. This study, based on problem reduction theory, uses a hypermedia prototype system to support decision processes for solving a financial analysis problem. An exploratory laboratory experiment was conducted to study the feasibility of the prototype for hypermedia support of decision making. The process tracing techniques used suggest that a cognitive map of a decision maker's thought process may be constructed. Results offer a great deal of promise in the use …

Mass-Market Designed-For-Cellular Mmics Can Be Gainfully Adapted For Use In Niche Applications On Different Frequencies, Chin-Leong Lim

Chin-Leong Lim

Due to semiconductor manufacturers’ near exclusive focus on high growth markets such as cellular and wireless data, very little commercial RND resource is expended on developing Microwave Monolithic Integrated Circuits (MMIC) for the lower-volume traditional wireless services such as aviation and land mobile, etc. To circumvent the dearth of MMICs in those under-served market segments, we intend to show how off-the-shelf cellular MMICs can be leveraged into non-cellular applications. For this purpose, a MMIC originally conceived as a 900 MHz 0.5W driver amplifier is redeployed to two dissimilar applications: (i) a high linearity Low Noise Amplifier (LNA) for the 400~520 …

Power Handling And Related Frequency Scaling Advantages In Piezoelectric Aln Contour-Mode Mems Resonators, Chengjie Zuo, Matteo Rinaldi, Gianluca Piazza

Matteo Rinaldi

This paper reports on the analytical modeling and experimental verification of the mechanically-limited power handling and nonlinearity in piezoelectric aluminum nitride (AlN) contour-mode resonators (CMR) having different electrode configurations (thickness field excitation, lateral field excitation, one-port and two-port configurations) and operating at different frequencies (177-3047 MHz). Despite its simplicity, the one-dimensional analytical model fits the experimental behavior of AlN CMRs in terms of power handling capabilities. The model and experiment also confirm the advantage of scaling (i.e. miniaturizing) the AlN CMRs to higher frequencies at which higher critical power density can be more easily attained up to values in excess …