Data security in unattended wireless sensor networks with mobile sinks

Unattended wireless sensor networks operating in hostile environments face the risk of compromise. Given the unattended nature, sensors must safeguard their sensed data of high value temporarily. However, saving data inside a network creates security problems due to the lack of tamper‐resistance of sensors and the unattended nature of the network. In some occasions, a network controller may periodically dispatch mobile sinks to collect data. If a mobile sink is given too many privileges, it will become very attractive for attack. Thus, the privilege of mobile sinks should be restricted. Additionally, secret keys should be used to achieve data confidentiality, integrity, and authentication between communicating parties. To address these security issues, we present mAKPS, an asymmetric key predistribution scheme with mobile sinks, to facilitate the key distribution and privilege restriction of mobile sinks, and schemes for sensors to protect their collected data in unattended wireless sensor networks. Copyright © 2011 John Wiley & Sons, Ltd.     

Performance of (1 1 0) p-channel SOI-MOSFETs fabricated by deep-amorphization and solid-phase epitaxial regrowth processes

The impact of local deep-amorphization (DA) and subsequent solid-phase epitaxial regrowth (SPER) are studied for the co-integration of devices with hybrid surface orientation. Thin-body p-channel transistors with 20 nm thick film and HfO₂ gate insulator/metal gate along several directions on a (1 1 0) substrate were fabricated and characterized. No deterioration of transconductance or threshold voltage was induced by DA/SPER process. Device co-integration using DA/SPER process is therefore a realistic option. 〈1 1 0〉 channel on (1 1 0) SOI film yields a 200% gain on the current for the (1 0 0) surface orientation. However, the benefit of it decreases with the channel length.     

Gate-induced drain leakage in FD-SOI devices: What the TFET teaches us about the MOSFET

This paper compares the gate-induced drain leakage (GIDL) in fully-depleted (FD) silicon-on-insulator (SOI) tunneling field effect transistor (TFET) and in standard metal-oxide-semiconductor FET (MOSFET) fabricated in the same process. The measurements show that the MOSFET GIDL current is lower than the GIDL in a TFET with the same junction doping, especially for devices with thick gate oxide and under low drain bias. A model describing lateral band-to-band tunneling (BTBT) is developed for GIDL in the FD-SOI TFET. By combining the model of gate-controllable tunneling diode in series with a field effect diode, we achieve an accurate picture of GIDL in FD-SOI MOSFETs.     

Effect of hydrogen producing mixed culture on performance of microbial fuel cells

This study examined the influence of H₂-producing mixed cultures on improving power generation using air-cathode microbial fuel cells (MFCs) inoculated with heat-treated anaerobic sludge. The MFCs installed with graphite brush anode generated higher power than the MFCs with carbon cloth anode, regardless heat treatment of anaerobic sludge. When the graphite brush anode-MFCs were inoculated selectively with H₂-producing bacteria by heat treatment, power production was not improved (about 490 mW/m²) in batch mode operation, but for slightly increased in carbon cloth anode-MFCs (from 0.16 to 2.0 mW/m²). Although H⁺/H₂ produced from H₂-producing bacteria can contribute to the performance of MFCs, suspended biomass did not affect the power density or potential, but the Coulombic efficiency (CE) increased. A batch test shows that propionate and acetate were used effectively for electricity generation, whereas butyrate made a minor contribution. H₂-producing mixed cultures do not affect the improvement in power generation and seed sludge, regardless of the pretreatment, can be used directly for the MFC performance.     

Web behavior analysis in social life logging

The Journal of Supercomputing - Collection of web behavior relies on self-report and web logs in daily life. The self-report is derived on memory and can seem ambiguous for analyzing web behavior....     

Functionalized Polyurethane-Coated Fabric with High Breathability,Durability, Reusability,and Protection Ability

Transmission of pathogens via respiratory droplets can spread infections such as COVID-19. Wearing a mask hinders the spread of COVID-19 infection and has become mandatory in some cases. Although most masks are affordable and disposable, continual daily replacement is required due to their performance deterioration caused by washing and contamination. Hence, a urethane-reactive coating material comprising perfluoro-tert-butanol-hexamethylene diisocyanate is developed with highly hydrophobic and oleophobic properties to functionalize a polyurethane-coated fabric to bestow high breathability, durability, reusability, and protection ability. Its functions are maintained after scratch and wash testing, and its air permeability and water vapor transmittance rate (necessary for respiration) are unaffected. Its filtration efficiency of water droplets containing 100 nm polystyrene particles (similar in size to SARS-CoV-2) is increased due to its highly hydrophobic properties. In addition, it inhibits the adsorption of bovine serum albumin, the spike protein of COVID-19, and Staphylococcus aureus and Pseudomonas aeruginosa.     

Low-temperature mobility behaviour in submicron MOSFETs and related determination of channel length and series resistance

The electron mobility behaviour in submicron MOSFETs is studied in the temperature range of 77–300 K. As the effective channel length is reduced, the effective mobility as well as the field-effect mobility are found to decrease and to become less temperature dependent. These experimental results are explained by the influence of series resistance and effective channel length, which are both temperature dependent. The possibility of accurate determination of series resistance and “pure” mobility is demonstrated. A new method is proposed to determine submicron MOSFET channel length at low temperatures.     

A new lifetime characterization technique using drain current transients in SOI material

A new technique based on the transient operation of the pseudo-MOS transistor is proposed for direct evaluation of generation lifetime and surface velocity in SOI wafers. The main advantages of the proposed technique are: (i) in situ operation (no prior processing of a transistor), (ii) set-up simplicity, (iii) fast comparison of different SOI technologies and (iv) simple identification of Si-film conductivity type. The influence of the electrical and non-electrical parameters of this technique is systematically investigated. Various SOI wafers (SIMOX and UNIBOND) are compared.     

A wide-band high-accuracy incremental ADC

In this paper, a high resolution and wideband incremental ADC with extended counting is described and analyzed. The modulator introduced inter-stage gain to reduce the quantization noise without adding any hardware. Also, a gain scaling technique was used to decrease the power consumption by reducing the integrators’ output swing. First, the 2nd order incremental ΔΣ ADC and 11-bit SAR ADC were measured separately. Second, the incremental ΔΣ ADC with extended counting was tested. It achieved a 91.6 dB dynamic range and 77.8 dB SNDR in the 0–1.25 MHz signal band. The total power consumption is 53.5 mW with dual power supplies (analog 3.3 V, digital 1.8 V).     

The Role of Organizational and Individual Characteristics in Technology Acceptance

The roles that users' individual and organizational characteristics play in technology acceptance were examined. Perceived work group characteristics was considered an organizational characteristic; attitude toward change and job stress were considered individual characteristics. User satisfaction with system characteristics was considered a consequence of technology acceptance. Data were collected from a sample of 236 Korean expatriates in information technology (IT) industries who were assigned to work in the United States. Perceived work group characteristics, attitude toward change, and job stress were related to one of the technology acceptance variables, perceived ease of use of the IT system. Ease of use was, in turn, related to perceived usefulness of the IT system, the other technology acceptance variable. Both perceived ease of use and usefulness were related to user satisfaction.