Physical Sciences and Mathematics Commons^™

Optimal Error Of Query Sets Under The Differentially-Private Matrix Mechanism, Chao Li, Gerome Miklau

Gerome Miklau

A common goal of privacy research is to release synthetic data that satisfies a formal privacy guarantee and can be used by an analyst in place of the original data. To achieve reasonable accuracy, a synthetic data set must be tuned to support a specified set of queries accurately, sacrificing fidelity for other queries.

This work considers methods for producing synthetic data under differential privacy and investigates what makes a set of queries "easy" or "hard" to answer. We consider answering sets of linear counting queries using the matrix mechanism, a recent differentially-private mechanism that can reduce error by adding …

Marine Investigations Of Greece's Santorini Volcanic Field, Haraldur Sigurdsson, Steven Carey, Matina Alexandri, Georges Vougioukalakis, Katherine Croff, Chris Roman, Dimitris Sakellariou, Christos Anagnostou, Grigoris Rousakis, Chrysanti Ioakim, Aleka Goguo, Dionysis Ballas, Thanassis Misaridis, Paraskevi Nomikou

Christopher N. Roman

The most recent major explosive eruption of the Santorini volcano in Greece—around 3600 years before present (B.P.), often referred to as the Minoan eruption—is one of the largest volcanic events known in historical time and has been the subject of intense volcanological and archeological studies [Druitt et al., 1999]. The submarine volcano Kolumbo, located seven kilometers northeast of Santorini and associated with Santorini's tectonic system, erupted explosively in 1650 A.D., resulting in fatalities on the island of Thera [Fouqué, 1879]. A large fraction of the erupted products from the Minoan eruption has been deposited in the …

Variable Morphologic Expression Of Volcanic, Tectonic, And Hydrothermal Processes At Six Hydrothermal Vent Fields In The Lau Back-Arc Basin, Vicki Lynn Ferrini, Margaret K. Tivey, Suzanne M. Carbotte, Fernando Martinez, Chris Roman

Christopher N. Roman

Ultrahigh-resolution bathymetric maps (25 cm grid) are used to quantify the physical dimensions of and spatial relationships between tectonic, volcanic, and hydrothermal features at six hydrothermal vent fields in the Lau back-arc basin. Supplemented with near-bottom photos, and nested within regional DSL-120A side-scan sonar data, these maps provide insight into the nature of hydrothermal systems along the Eastern Lau Spreading Center (ELSC) and Valu Fa Ridge (VFR). Along-axis transitions evident in localized volcanic morphology and tectonic characteristics include a change from broad low-relief volcanic domes (hundreds of meters wide,tall) that are dominated by pillow and lobate lava morphologies and are …

Concept Tests For A New Wire Flying Vehicle Designed To Achieve High Horizontal Resolution Profiling In Deep Water, Chris Roman, Dave Hebert

Christopher N. Roman

Efficiently profiling the water column to achieve both high vertical and horizontal resolution from a moving vessel in deep water is difficult. Current solutions, such as CTD tow-yos, moving vessel profilers, and undulating tow bodies, are limited by ship speed or water depth. As a consequence, it is difficult to obtain oceanographic sections with sufficient resolution to identify many relevant scales over the deeper sections of the water column. This paper presents a new concept for a profiling vehicle that slides up and down a towed wire in a controlled manner using the lift created by wing foils. The wings …

Seabed Auv Offers New Platform For High-Resolution Imaging, Hanumant Singh, Ali Can, Ryan Eustice, Steve Lerner, Neil Mcphee, Chris Roman

Christopher N. Roman

A number of marine biological, geological, and archaeological applications share the need for high-resolution optical and acoustic imaging of the sea floor [Ballard et al., 2002; Greene et al., 2000; Shank et al., 2002]. In particular,there is a compelling need to conduct studies in depths beyond those considered reasonable for divers (∼50 m) down to depths at the shelf edge and continental slope (∼1000–2000 m). Some of the constraints associated with such work include the requirement to work off of small coastal vessels or fishing boats of opportunity,and the requirement for the vehicle components to be air-shippable to enable inexpensive …

Oscillator Strength Measurements Of The 5s6s 1s0→5snp 1p1 Rydberg Transitions Of Strontium, S. U. Haq, M. A. Kalyar, M. Rafiq, R. Ali, Naveed K. Piracha, M. A. Baig

Naveed K. Piracha

We report the experimentally determined oscillator strengths for the 5s6s 1S0→5snp 1P1 Rydberg transitions of strontium using two-step excitation in conjunction with a thermionic diode ion detector. The absolute photoionization cross section from the 5s6s 1S0 excited state has been determined by adjusting the polarization vector of the ionizing laser beam parallel, perpendicular, and at the magic angle with respect to that of the exciting dye laser. The measured absolute value of the photoionization cross section 0.9±0.2 Mb at the 5s threshold is used to extract the f values of the 5s6s 1S0→5snp 1P1 (26≤n≤73) Rydberg transitions. The oscillator strength …

U.S. Drought Monitor, December 18, 2012, David Simeral

United States Agricultural Commodities in Drought Archive

Drought map of U.S. for December 18, 2012 (12/18/12) plus: U.S. crop areas experiencing drought (map), Approximate percentage of crop located in drought, by state (bar graph), Percent of crop area located in drought, past 52 weeks (line graph) for: Hay, Cattle, Winter wheat.

Socio-Environmental Considerations At The Usuma Reservoir In Abuja, Nigeria, Fanan Ujoh Mr, James Ikyernum Mr, Olarewaju O. Ifatimehin Dr

Dr. Fanan Ujoh

Reservoirs are Man’s attempt towards water re-distribution from regions/seasons of abundance/surplus to regions/seasons of scarcity. This study focuses on socio-environmental impacts of the Lower Usuma dam in Abuja, on its four surrounding communities. Stratified random sampling technique was employed in the administration of a questionnaire to 200 respondents. Using descriptive statistics and the student t-test for the analysis, the study discovered that: (i) there has been no significant improvement in infrastructure provision by Government; (ii) cases of water-borne diseases are high; (iii) the communities have lost land for cultivation; and, (iv) the communities believe that the resettlement scheme is not …

Using Remote Sensing Data To Improve Rice Production In Kutigi, Niger State, Nigeria, Jibril Musa Phd, M B. Yunusa

Confluence Journal Environmental Studies (CJES), Kogi State University, Nigeria

This research work looked in the used of Remote Sensing to improve Agricultural production in Kutigi, Niger State. The aim of the study is to use remote sensing to improve rice farming activities in Kutigi, Niger State. It is very important to identify such methods to improve Agricultural production because experts are always interested in new researches and findings to better the standard of living in any environment. In view of this, Remotely-sensed data could be used or employed to elevate most of these agricultural problems in Kutigi through the following objectives: Using Landsat imagery to assess the present landuse …

Relating Nanoparticle Properties To Biological Outcomes In Exposure Escalation Experiments, Trina Patel, Cecile Low-Kam, Zhaoxia Ji, Haiyuan Zhang, Tian Xia, Andre E. Nel, Jeffrey I. Zinc, Donatello Telesca

COBRA Preprint Series

A fundamental goal in nano-toxicology is that of identifying particle physical and chemical properties, which are likely to explain biological hazard. The first line of screening for potentially adverse outcomes often consists of exposure escalation experiments, involving the exposure of micro-organisms or cell lines to a battery of nanomaterials. We discuss a modeling strategy, that relates the outcome of an exposure escalation experiment to nanoparticle properties. Our approach makes use of a hierarchical decision process, where we jointly identify particles that initiate adverse biological outcomes and explain the probability of this event in terms of the particle physico-chemical descriptors. The …

The Analysis Of Speech Codecs Using Psychoacoustic Measures, M. Raad, C. H. Ritz, I. Burnett, Alfred Mertins

Dr Christian Ritz

This paper analyses two narrowband speech codecs, the 4.8 kbit/s FS1016 coder and the 8 kbit/s G729 coder, using objective psychoacoustic measures. Four measures are used: loudness, sharpness, roughness and tonality. The results show sharpness and roughness as the two major contributing factors to the subjective difference between the two coders.

Enhancing Interoperability Via Generic Multimedia Syntax Translation, Joseph Thomas-Kerr, I. Burnett, C. H. Ritz

Dr Christian Ritz

The Bitstream Binding Language (BBL) is a new technology developed by the authors and being standardized by MPEG, which describes how multimedia content and metadata can be mapped onto streaming formats. This paper describes how BBL can be used to enhance the interoperability of multimedia content by providing a generic mechanism for the translation of content between formats. As new content formats are developed, BBL can be used to describe how to translate the content into a form that existing devices are able to render. This consequently simplifies the adoption of new multimedia content forms because existing devices are able …

An Ambient Multimedia User Experience Feedback Framework Based On User Tagging And Eeg Biosignals, Eva Cheng, Stephen J. Davis, Ian Burnett, Christian H. Ritz

Dr Christian Ritz

Multimedia is increasingly accessed online and within social networks; however, users are typically limited to visual/auditory stimulus through media presented onscreen with accompanying audio over speakers. Whilst recent research studying additional ambient sensory multimedia effects recorded numerical scores of perceptual quality, the users’ time-varying emotional response to the ambient sensory feedback is not considered. This paper thus introduces a framework to evaluate user ambient quality of multimedia experience and discover users’ time-varying emotional responses through explicit user tagging and implicit EEG biosignal analysis. In the proposed framework, users interact with the media via discrete tagging activities whilst their EEG biosignal …

Is That A Fish In Your Ear? A Universal Metalanguage For Multimedia, Joseph Thomas-Kerr, I. Burnett, C. H. Ritz, S. Devillers, D. De Schrijever, R. Van De Walle

Dr Christian Ritz

Universal Multimedia Access promises to adaptively deliver multimedia content to users according to their needs?whether it's their device, context, or preferences. Central to UMA is the development of metadata standards for describing multimedia resources to allow their adaptation. In this article, the authors report on the development of the Bitstream Syntax Description Language (BSDL) and describe applications for scalable content adaptation, format independent streaming, and delivery and configurable media coding.

Low Bit Rate Wideband Wi Speech Coding, C. H. Ritz, I. Burnett, Jason Lukasiak

Dr Christian Ritz

This paper investigates waveform interpolation (WI) applied low bit rate wideband speech coding. An analysis of the evolutionary behaviour of wideband characteristic waveforms (CWs) shows that direct application of the classical WI algorithm may not be appropriate for wideband speech. We propose a modification whereby CW quantisation is performed using classical WI decomposition for the low frequency region and noise modelling for the high frequency region. Wideband WI coders incorporating this modification and operating at 4 kbps and 6 kbps are described. Subjective testing of these coders shows that WI is a promising approach to low bit rate wideband speech …

Very Low Rate Speech Coding Using Temporal Decomposition And Waveform Interpolation, C. H. Ritz, I. Burnett, J Lukasiak

Dr Christian Ritz

In very low rate coding the aim is to accurately represent speech characteristics as efficiently as possible. High coding gains for the spectral features can be achieved through the use of temporal decomposition. Waveform interpolation coders accurately represent the excitation using characteristic waveforms (CWs) extracted at a constant rate. In this paper, the two approaches are combined into a very low rate coder operating at around 1 kbps. It is shown that the evolution of the excitation is related to the evolution of the speech spectrum. To minimise bit rates, the transmission of CWs is adapted to the spectral parameter …

Extending Waveform Interpolation To Wideband Speech Coding, C. H. Ritz, I. Burnett, Jason Lukasiak

Dr Christian Ritz

This paper investigates the extension of waveform interpolation (WI) to wideband speech coding. Included is an analysis of the evolutionary behaviour of wideband speech and the consequences for WI. We highlight problems associated with direct application of the classical WI algorithm applied to wideband speech.

Query Streaming For Multimedia Query By Content From Mobile Devices, Kevin Adistambha, S. J. Davis, Christian H. Ritz, I. Burnett

Dr Christian Ritz

Formulating and processing of multimedia queries using mobile devices presents many challenges. This is due to the limitations of the devices themselves and the cost of the bandwidth involved in transmitting multimedia data between servers and devices. In this paper we propose a novel approach: “query streaming” which uses Reverse Polish Notation to perform multimedia query-by-example on a mobile device and server. An important advantage of query streaming is the ability to perform a query within the previous result set. To solve the problem of limited resources, the concept of result set examination using Fragment Request Units and Fragment Update …

Principles And Analysis Of The Squeezing Approach To Low Bit Rate Spatial Audio Coding, B. Cheng, C. H. Ritz, I. Burnett

Dr Christian Ritz

This paper presents a novel solution to multichannel spatial audio coding: spatial squeezing surround audio coding (S3AC). The S3AC scheme analyses a multichannel audio signal and downmixes it into a stereo signal pair containing both the monophonic properties of audio sources and their localization information; this avoids the need for side information. The approach uses time-frequency analysis of a spatial audio scene and exploits virtual sources and amplitude panning techniques to 'squeeze' 360deg of a horizontal soundfield to a 60deg stereo signal pair. In comparison with other spatial audio coding techniques, S3AC significantly advances in-band encoding of the localization information …

Temporal Decomposition For Low Rate Wideband Speech Compression, C. H. Ritz, I. Burnett

Dr Christian Ritz

An investigation into low bit rate wideband speech coding for applications such as unicast streaming is presented. Wideband spectral parameters are quantised below 1 kbit/s using temporal decomposition (TD) applied to the line spectral frequencies. Quantisation using TD performs significantly better than split vector quantisation at an equivalent bit rate.

Transcoding Of Narrowband To Wideband Speech, Christian H. Ritz, Nick Harders, Joseph Hermann, Matthew J. Baker

Dr Christian Ritz

Transcoding is required to facilitate the communication of compressed speech between networks that have adopted opposing speech coding standards. The traditional transcoding technique of tandem conversion by decoding from the old standard and then re-encoding with the new standard suffers from unacceptable delay and complexity. For real time applications, delay and complexity can be reduced by performing transcoding in the bit stream domain. This paper describes techniques for transcoding between narrowband and wideband speech coding standards. In particular, an examination of the performance of bit stream mapping approaches to transcoding from the ITU-T G.729 narrowband speech coder to the ITU-T …

A Survey And Tutorial Of Rfid Anti-Collision Protocols, Dheeraj Klair, Kwan-Wu Chin, Raad Raad

Dr Raad Raad

RFID technologies have revolutionized the asset tracking industry, with applications ranging from automated checkout to monitoring the medication intakes of elderlies. In all these applications, fast, and in some cases energy efficient, tag reading is desirable, especially with increasing tag numbers. In practice, tag reading protocols face many problems. A key one being tag collision, which occurs when multiple tags reply simultaneously to a reader. As a result, an RFID reader experiences low tag reading performance, and wastes valuable energy. Therefore, it is important that RFID application developers are aware of current tag reading protocols. To this end, this paper …

Audio Coding Using Sorted Sinusoidal Parameters, Mohammed Raad, I. Burnett

Dr Raad Raad

This paper describes a new audio coding scheme based on sinusoidal coding of signals. Sinusoidal coding permits the representation of a given signal through the summation of sinusoids. The parameters of the sinusoids (the amplitudes, phases and frequencies) are transmitted to allow the signal reconstruction. In the proposed scheme, the sinusoidal parameters are sorted according to energy content and perceptual significance. The most significant parameters are transmitted first allowing the use of only a small set of the parameters for signal reconstruction. The proposed scheme incurs a low delay and uses a 20 ms frame length. Results show that the …

Ardez: A Low Power Asymmetric Rendezvous Mac For Sensor Networks, K. Chin, Mohammed Raad

Dr Raad Raad

We present a rendezvous based medium access control (MAC), culled ArDeZ, for use in sensor networks. ArDeZ is a TDMA based medium access scheme that does not rely on strict time slot positioning and assignments, making ArDeZ easily deployable in large sensor networks without having to adhere to strict time slot boundaries. ArDeZ establishes two independent peer-to-peer time channels between nodes, and these channels do not necessarily have the same duty cycle. Each channel has a set of rendezvous periods associated with it that are generated from a seed exchanged during the setup process. Further, the duration and frequency of …

Connection Admission Control In Micro-Cellular Multi-Service Mobile Networks, R. S. Raad, E. Dutkiewicz, Joe F. Chicharo

Dr Raad Raad

This paper investigates the use of fixed bandwidth reservation for multi-service mobile networks. In particular it extends previous fixed multi-service network results to the mobile scenario and presents analytical and simulation results for new and handover call blocking probabilities. It also investigates the performance sensitivity to different traffic load ratios as well as the cell dwell time distribution.

Media Rate Control For Large Scale Immersive Communications, Mohammed Raad, Raad Raad, Farzad Safaei

Dr Raad Raad

A video rate control mechanism based on a modified LMS algorithm is presented. The control mechanism is used within a real-time IP multicast based system. Simulation results show that such a control mechanism allows the system to adapt to the varying network conditions of receiving clients.

Improving Bdd Cryptosystems In General Lattices, Willy Susilo, Thomas Plantard, Michael Rose

Dr Thomas Plantard

No abstract provided.

Reaction Attack On Outsourced Computing With Fully Homomorphic Encryption Schemes, Zhenfei Zhang, Thomas Plantard, Willy Susilo

Dr Thomas Plantard

Outsourced computations enable more efficient solutions towards practical problems that require major computations. Nevertheless, users’ privacy remains as a major challenge, as the service provider can access users’ data freely. It has been shown that fully homomorphic encryption schemes might be the perfect solution, as it allows one party to process users’ data homomorphically, without the necessity of knowing the corresponding secret keys. In this paper, we show a reaction attack against full homomorphic schemes, when they are used for securing outsourced computation. Essentially, our attack is based on the users’ reaction towards the output generated by the cloud. Our …

On The Cca-1 Security Of Somewhat Homomorphic Encryption Over The Integers, Zhenfei Zhang, Thomas Plantard, Willy Susilo

Dr Thomas Plantard

The notion of fully homomorphic encryption is very important since it enables many important applications, such as the cloud computing scenario. In EUROCRYPT 2010, van Dijk, Gentry, Halevi and Vaikuntanathan proposed an interesting fully homomorphic encryption scheme based on a somewhat homomorphic encryption scheme using integers. In this paper, we demonstrate a very practical CCA-1 attack against this somewhat homomorphic encryption scheme. Given a decryption oracle, we show that within O(λ2) queries, we can recover the secret key successfully, where λ is the security parameter for the system.

Processing Resource Scheduling In Programmable Networks, Farzad Safaei, D. Platt, Sanjay Jha, F. Sabrina, Cong Duc Nguyen

Dr Donald Platt

No abstract provided.