The Experts below are selected from a list of 360 Experts worldwide ranked by ideXlab platform
Javier Cadena - One of the best experts on this subject based on the ideXlab platform.
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ocean bottom seismometer design and test of a measurement system for marine seismology
Sensors, 2012Co-Authors: A Manuel, X Roset, Joaquin Del Rio, Daniel Mihai Toma, Normandino Carreras, Shahram Shariat Panahi, Albert Garciabenadi, Tim Owen, Javier CadenaAbstract:The Ocean Bottom Seismometer (OBS) is a key instrument for the geophysical study of sea sub-bottom layers. At present, more reliable autonomous instruments capable of recording underwater for long periods of time and therefore handling large data storage are needed. This paper presents a new Ocean Bottom Seismometer designed to be used in long duration seismic surveys. Power consumption and noise level of the acquisition system are the key points to optimize the autonomy and the data quality. To achieve our goals, a new low power data logger with high resolution and Signal–to-Noise Ratio (SNR) based on Compact Flash Memory Card is designed to enable continuous data acquisition. The equipment represents the achievement of joint work from different scientific and technological disciplines as electronics, mechanics, acoustics, communications, information technology, marine geophysics, etc. This easy to handle and sophisticated equipment allows the recording of useful controlled source and passive seismic data, as well as other time varying data, with multiple applications in marine environment research. We have been working on a series of prototypes for ten years to improve many of the aspects that make the equipment easy to handle and useful to work in deep-water areas. Ocean Bottom Seismometers (OBS) have received growing attention from the geoscience community during the last forty years. OBS sensors recording motion of the ocean floor hold key information in order to study offshore seismicity and to explore the Earth’s crust. In a seismic survey, a series of OBSs are placed on the seabed of the area under study, where they record either natural seismic activity or acoustic signals generated by compressed air-guns on the ocean surface. The resulting data sets are subsequently used to model both the earthquake locations and the crustal structure.
Alexander A Shvartsman - One of the best experts on this subject based on the ideXlab platform.
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malicious takeover of voting systems arbitrary code execution on optical scan voting terminals
ACM Symposium on Applied Computing, 2013Co-Authors: Russell J Jancewicz, Aggelos Kiayias, Laurent Michel, Alexander Russell, Alexander A ShvartsmanAbstract:This work focuses on the AccuVote Optical Scan voting terminal (AV-OS) that is widely used in US elections. We present a new attack that can be delivered without opening the system enclosure, and without changing a single bit of the system's firmware. The attack is launched by inserting a maliciously programmed AV-OS Memory Card into the terminal. The Card contains binary code that exploits careless runtime Memory management in the system's firmware to transfer control to alternate routines stored in the Memory Card. Once the control is taken by the injected code, the voting system is forced to operate according to the wishes of the attacker. In particular, given that the attack results in the execution of the arbitrary code, an attacker can completely take over AV-OS operation and compromise the results of an election. It is also noteworthy that once a Memory Card is compromised it can be duplicated using the native function of the voting terminal. In some past elections it was observed that up to 6% of all Memory Cards were involved in Card duplication. There exists a non-trivial possibility that the infection on one Memory Card can propagate virally to other Cards in a given election. This development was performed without access to the source code of the AV-OS system and without access to any internal vendor documentation. We note that this work is performed solely with the purpose of security analysis of AV-OS.
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pre election testing and post election audit of optical scan voting terminal Memory Cards
Conference on Electronic voting technology workshop on trustworthy elections, 2008Co-Authors: Seda Davtyan, Aggelos Kiayias, Laurent Michel, Alexander Russell, Sotiris Kentros, Nicolas Nicolaou, Andrew See, Narasimha Shashidhar, Alexander A ShvartsmanAbstract:Optical scan electronic voting machines employ software components that are customized for each specific election. Such software components are critical from a security and integrity point of view, as they define ballot layout and outcome reporting facilities. The possibility of these components to be tampered with presents a major concern as incorrect election results may be produced due to either malicious interference or accidental corruption. Erroneous results caused by tampering or corruptions can go unnoticed in the absence of testing and auditing, and the errors may not be detectable by election officials/poll workers using the pre-election testing procedures that rely on the machines themselves. This paper presents an actual auditing process for the AccuVote Optical Scan Voting Terminal (AV-OS) (manufactured by Premier Election Solutions) and the ensuing results from a recent statewide audit, showing that thorough auditing of a large sample of voting hardware, specifically the Memory Cards that contain custom software components, is both practical and informative. We argue that Memory Card audits are crucial in providing timely information and maintaining the integrity of the electoral process. To substantiate this claim, we present as part of our results hard evidence of inadequate reliability of certain hard-ware components used with the voting terminals, and indications of marginal procedural compliance on the part of the poll workers. These audits were performed without any access to the manufacturer's source code or the documentation regarding the design or the internal workings of the AV-OS terminal. We conclude the paper with several observations based on what was learned during the Memory Card audit process and offer recommendations aimed at enhancing the integrity of elections. The audits presented in this paper were performed on request of the Office of the Secretary of the State of Connecticut.
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an authentication and ballot layout attack against an optical scan voting terminal
USENIX Workshop on Accurate Electronic Voting Technology, 2007Co-Authors: Aggelos Kiayias, Laurent Michel, Alexander Russell, Andrew See, Narasimha Shashidhar, Alexander A ShvartsmanAbstract:Recently, two e-voting technologies have been introduced and used extensively in election procedures: direct recording electronic (DRE) systems and optical scanners. The latter are typically deemed safer as many recent security reports have discovered substantial vulnerabilities in a variety of DRE systems. In this paper we present an attack against the Diebold Accuvote optical scan voting terminal (AV-OS). Previously known attacks direct to the AV-OS required physical access to the Memory Card and use of difficult to find hardware (Card reader/writer). Our attack bypasses these issues by using the serial port of the AV-OS terminal and reverse engineering the communication protocol, in essence, using the terminal itself as a reader/writer. Our analysis is based solely on reverse-engineering. We demonstrate how an attacker can exploit the serious security vulnerability of weak (non-cryptographic) authentication properties of the terminal. The attack payload delivers a tampered ballot layout that, depending on the scenario, allows swapping of candidate votes, neutralizing votes, or even shifting votes from one candidate to another.
Lanrong Dung - One of the best experts on this subject based on the ideXlab platform.
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a nand flash Memory controller for sd mmc flash Memory Card
IEEE Transactions on Magnetics, 2007Co-Authors: Lanrong DungAbstract:In this paper, a novel NAND flash Memory controller was designed. A t-EC w-bit parallel Bose-Chaudhuri-Hocquengham (BCH) error-correction code (ECC) was designed for correcting the random bit errors of the flash Memory chip, which is suitable for the randomly bit errors property and parallel I/O interface of the NAND-type flash Memory. A code-banking mechanism was designed for the tradeoffs between the controller cost and the in-system programmability (ISP) support. With the ISP functionality and the Flash parameters programmed in the reserved area of the flash Memory chip during the Card production stage, the function for supporting various kinds of NAND flash Memory could be provided by a single controller. In addition, built-in defect management and wear-leveling algorithm enhanced the product life cycle and reliability. Dual channel accessing of the Flash Memory provided the good performance in data transfer rate. With respect to the proposed controller architecture, a real secure digital Card (SD)/multimedia Card (MMC) flash Memory Card controller chip was designed and implemented with UMC 0.18 mum CMOS process. Experimental results show the designed circuit can fully comply with the system specifications and shows the good performances
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a nand flash Memory controller for sd mmc flash Memory Card
IEEE Transactions on Magnetics, 2007Co-Authors: Lanrong DungAbstract:In this paper, a novel NAND flash Memory controller was designed. A t-EC w-bit parallel Bose-Chaudhuri-Hocquengham (BCH) error-correction code (ECC) was designed for correcting the random bit errors of the flash Memory chip, which is suitable for the randomly bit errors property and parallel I/O interface of the NAND-type flash Memory. A code-banking mechanism was designed for the tradeoffs between the controller cost and the in-system programmability (ISP) support. With the ISP functionality and the Flash parameters programmed in the reserved area of the flash Memory chip during the Card production stage, the function for supporting various kinds of NAND flash Memory could be provided by a single controller. In addition, built-in defect management and wear-leveling algorithm enhanced the product life cycle and reliability. Dual channel accessing of the Flash Memory provided the good performance in data transfer rate. With respect to the proposed controller architecture, a real secure digital Card (SD)/multimedia Card (MMC) flash Memory Card controller chip was designed and implemented with UMC 0.18 mum CMOS process. Experimental results show the designed circuit can fully comply with the system specifications and shows the good performances
A Manuel - One of the best experts on this subject based on the ideXlab platform.
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ocean bottom seismometer design and test of a measurement system for marine seismology
Sensors, 2012Co-Authors: A Manuel, X Roset, Joaquin Del Rio, Daniel Mihai Toma, Normandino Carreras, Shahram Shariat Panahi, Albert Garciabenadi, Tim Owen, Javier CadenaAbstract:The Ocean Bottom Seismometer (OBS) is a key instrument for the geophysical study of sea sub-bottom layers. At present, more reliable autonomous instruments capable of recording underwater for long periods of time and therefore handling large data storage are needed. This paper presents a new Ocean Bottom Seismometer designed to be used in long duration seismic surveys. Power consumption and noise level of the acquisition system are the key points to optimize the autonomy and the data quality. To achieve our goals, a new low power data logger with high resolution and Signal–to-Noise Ratio (SNR) based on Compact Flash Memory Card is designed to enable continuous data acquisition. The equipment represents the achievement of joint work from different scientific and technological disciplines as electronics, mechanics, acoustics, communications, information technology, marine geophysics, etc. This easy to handle and sophisticated equipment allows the recording of useful controlled source and passive seismic data, as well as other time varying data, with multiple applications in marine environment research. We have been working on a series of prototypes for ten years to improve many of the aspects that make the equipment easy to handle and useful to work in deep-water areas. Ocean Bottom Seismometers (OBS) have received growing attention from the geoscience community during the last forty years. OBS sensors recording motion of the ocean floor hold key information in order to study offshore seismicity and to explore the Earth’s crust. In a seismic survey, a series of OBSs are placed on the seabed of the area under study, where they record either natural seismic activity or acoustic signals generated by compressed air-guns on the ocean surface. The resulting data sets are subsequently used to model both the earthquake locations and the crustal structure.
Vijay K Varadan - One of the best experts on this subject based on the ideXlab platform.
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wireless remote monitoring system for sleep apnea
Proceedings of SPIE, 2011Co-Authors: Hyeokjun Kwon, Vijay K VaradanAbstract:Sleep plays the important role of rejuvenating the body, especially the central nervous system. However, more than thirty million people suffer from sleep disorders and sleep deprivation. That can cause serious health consequences by increasing the risk of hypertension, diabetes, heart attack and so on. Apart from the physical health risk, sleep disorders can lead to social problems when sleep disorders are not diagnosed and treated. Currently, sleep disorders are diagnosed through sleep study in a sleep laboratory overnight. This involves large expenses in addition to the inconvenience of overnight hospitalization and disruption of daily life activities. Although some systems provide home based diagnosis, most of systems record the sleep data in a Memory Card, the patient has to face the inconvenience of sending the Memory Card to a doctor for diagnosis. To solve the problem, we propose a wireless sensor system for sleep apnea, which enables remote monitoring while the patient is at home. The system has 5 channels to measure ECG, Nasal airflow, body position, abdominal/chest efforts and oxygen saturation. A wireless transmitter unit transmits signals with Zigbee and a receiver unit which has two RF modules, Zigbee and Wi-Fi, receives signals from the transmitter unit and retransmits signals to the remote monitoring system with Zigbee and Wi-Fi, respectively. By using both Zigbee and Wi-Fi, the wireless sensor system can achieve a low power consumption and wide range coverage. The system's features are presented, as well as continuous monitoring results of vital signals.