SUrface Copyright (c) 2013 Syracuse University All rights reserved. http://surface.syr.edu Recent documents in SUrface en-us Tue, 18 Jun 2013 01:35:20 PDT 3600 Sensing as a service: A cloud computing system for mobile phone sensing http://surface.syr.edu/eecs/244 http://surface.syr.edu/eecs/244 Tue, 11 Jun 2013 10:54:04 PDT Sensors on (or attached to) mobile phones can enable attractive sensing applications in different domains such as environmental monitoring, social networking, healthcare, etc. We introduce a new concept, Sensing-as-a-Service (S2aaS), i.e., providing sensing services using mobile phones via a cloud computing system. An S2aaS cloud should meet the following requirements:

1) It must be able to support various mobile phone sensing applications on different smartphone platforms.

2) It must be energy-efficient. 3) It must have effective incentive mechanisms that can be used to attract mobile users to participate in sensing activities. In this paper, we identify unique challenges of designing and implementing an S2aaS cloud, review existing systems and methods, present viable solutions, and point out future research directions.

]]> Xiang Xiang Sheng et al. Mediums: Visual integrity preserving framework http://surface.syr.edu/eecs/243 http://surface.syr.edu/eecs/243 Tue, 11 Jun 2013 10:53:59 PDT The UI redressing attack and its variations have spread across several platforms, from web browsers to mobile systems. We study the fundamental problem underneath such attacks, and formulate a generic model called the containerthreat model. We believe that the attacks are caused by the system’s failure to preserve visual integrity. From this angle, we study the existing countermeasures and propose a generic approach, Mediums framework, to develop a Trusted DisplayBase (TDB) to address this type of problems. We use the side channel to convey the lost visual information to users. From the access control perspective, we use the dynamic binding policy model to allow the server to enforce different restrictions based on different client-side scenarios.

]]> Tongbo Luo et al. Optimal Solution Based Plasmonic Interfaces for Photocurrent Enhancement in Silicon-on-Insulator Devices http://surface.syr.edu/eecs_thesis/2 http://surface.syr.edu/eecs_thesis/2 Tue, 28 May 2013 06:30:37 PDT Renewable energy sources are a vital topic to the future of growing industrialized nations. Solar cells are a popular potential technology to become a major source of energy supply, with Silicon (Si) being the most common solar cell semiconductor material. To address the cost of bulk Si, thin film amorphous Silicon (a-Si) solar cell technology was developed. The drawback to using thin film a-Si solar cells is the reduction in power efficiency compared to bulk Si cells. In this work we explore the use of local plasmon resonance and nanoparticle interfaces to enhance photocurrent within thin film Si. Silver (Ag) nano ink and synthesized Ag nanoparticles were deposited onto Silicon-on-insulator devices through a spin-coating technique. The photocurrent response to the plasmonic interface for several solution weights and particle sizes were analyzed. The photocurrent responses of varying solution weights of 40 nm diameter Ag nano ink particles were tested. The maximum photocurrent response was found to be 149.96 ± 6.69% with a surface coverage of 7% and a solution of 0.1% wt./vol. Two nanoparticle sizes of 31 nm and 69 nm were also synthesized through wet chemistry techniques. The 69 nm diameter particle had the greatest photocurrent enhancement of 198.84 ± 3.43%. The 31 nm diameter particles at the same solution dilution had a photcurrent enhancement of 48.92 ± 1.47%. This response is greater than the photocurrent enhancement of 16 nm diameter particles fabricated using the thermal evaporation and annealing techniques which reported a maximum enhancement of 33%. Using this simple method of prefabricating and spin-coating particles, reliable photocurrent enhancement may be achieved and the parameters of the nanoparticles may be controlled for maximum enhancement.

]]> Miriam Israelowitz Aerodynamic and Acoustic Features of Vocal Effort http://surface.syr.edu/spee_thesis/2 http://surface.syr.edu/spee_thesis/2 Tue, 28 May 2013 06:19:44 PDT Many voice disorders are associated with an effortful voice; however, there have been very few studies that have examined the physiological changes that contribute to this sense of effort. Determining the factors that contribute to change in vocal effort may help clinicians to effectively target these variables when working with people with voice disorders so that voice improvement is accompanied by decreased vocal effort after treatment. Prior research has shown that alterations in aerodynamic and acoustic variables are often associated with voice disorders involving increased muscular effort, and change in these variables is correlated with abnormal voice qualities. The current study focused on three main questions: 1) When producing speech with increased or decreased vocal effort as compared to comfortable vocal effort, how do healthy adults alter their phonatory physiology? 2) What are the acoustic manifestations of these changes in phonatory function that occur with high vocal effort? 3) Which aerodynamic or acoustic variables are the primary factors that are associated with an increase in vocal effort? The participants included 18 healthy men and women with normal voice and normal hearing, ranging in age from 18 to 26. After training, participants produced repeated syllable combinations at various levels of vocal effort (comfortable, maximal, and minimal). Aerodynamic and acoustic recordings were then analyzed. Three of the four aerodynamic measures in this study showed significant differences between the three vocal effort conditions, and reflected change in airflow, pressure, and rate of airflow change during voice production. Both acoustic measures, which related to the relative degree of harmonic energy in the speech signal also showed significant differences between the three vocal effort conditions.

]]> Allison Rosenthal Design of a Microstrip Bandpass Filter for 3.1-10.6 GHz Uwb Systems http://surface.syr.edu/eecs_thesis/1 http://surface.syr.edu/eecs_thesis/1 Tue, 28 May 2013 06:00:33 PDT In this thesis, ultra-wideband (UWB) microwave filters and design challenges are studied and, a microstrip UWB filter prototype design is presented. The UWB bandpass filter operating in the 3.6 GHz to 10.6 GHz frequency band is targeted to comply with the FCC spectral mask for UWB systems. The prototype filter is composed of quarter-wavelength spaced shunt stub transmission lines. The circuit is first simulated and optimized by using AWR DE simulation software tool. Then Sonnet EM Simulation and CST EM Simulation Tools are further utilized to obtain more accurate simulated results. The fabricated microstrip UWB bandpass filter is then measured using a vector network analyzer and results are presented. The prototype built can be used in UWB communications or localization systems.

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