33 research outputs found
Stake Your Claim: Zero-Trust Validator Deployment Leveraging NFTs and Smart Contracts in Proof-of-Stake Networks
We present a novel method for a multi-party, zero-trust validator
infrastructure deployment arrangement via smart contracts to secure
Proof-of-Stake (PoS) blockchains. The proposed arrangement architecture employs
a combination of non-fungible tokens (NFTs), a treasury contract, and validator
smart contract wallets to facilitate trustless participation in staking
mechanisms. The NFT minting process allows depositors to exchange their capital
for an NFT representing their stake in a validator, while the treasury contract
manages the registry of NFT holders and handles rewards distribution. Validator
smart contract wallets are employed to create a trustless connection between
the validator operator and the treasury, enabling autonomous staking and
unstaking processes based on predefined conditions. In addition, the proposed
system incorporates protection mechanisms for depositors, such as triggered
exits in case of non-payment of rewards and a penalty payout from the validator
operator. The arrangement benefits from the extensibility and interoperability
of web3 technologies, with potential applications in the broader digital
ecosystem. This zero-trust staking mechanism aims to serve users who desire
increased privacy, trust, and flexibility in managing their digital wealth,
while promoting greater decentralization and transparency in the PoS ecosystem
Towards a Practical Pedestrian Distraction Detection Framework using Wearables
Pedestrian safety continues to be a significant concern in urban communities
and pedestrian distraction is emerging as one of the main causes of grave and
fatal accidents involving pedestrians. The advent of sophisticated mobile and
wearable devices, equipped with high-precision on-board sensors capable of
measuring fine-grained user movements and context, provides a tremendous
opportunity for designing effective pedestrian safety systems and applications.
Accurate and efficient recognition of pedestrian distractions in real-time
given the memory, computation and communication limitations of these devices,
however, remains the key technical challenge in the design of such systems.
Earlier research efforts in pedestrian distraction detection using data
available from mobile and wearable devices have primarily focused only on
achieving high detection accuracy, resulting in designs that are either
resource intensive and unsuitable for implementation on mainstream mobile
devices, or computationally slow and not useful for real-time pedestrian safety
applications, or require specialized hardware and less likely to be adopted by
most users. In the quest for a pedestrian safety system that achieves a
favorable balance between computational efficiency, detection accuracy, and
energy consumption, this paper makes the following main contributions: (i)
design of a novel complex activity recognition framework which employs motion
data available from users' mobile and wearable devices and a lightweight
frequency matching approach to accurately and efficiently recognize complex
distraction related activities, and (ii) a comprehensive comparative evaluation
of the proposed framework with well-known complex activity recognition
techniques in the literature with the help of data collected from human subject
pedestrians and prototype implementations on commercially-available mobile and
wearable devices
Exploiting Out-of-band Motion Sensor Data to De-anonymize Virtual Reality Users
Virtual Reality (VR) is an exciting new consumer technology which offers an
immersive audio-visual experience to users through which they can navigate and
interact with a digitally represented 3D space (i.e., a virtual world) using a
headset device. By (visually) transporting users from the real or physical
world to exciting and realistic virtual spaces, VR systems can enable
true-to-life and more interactive versions of traditional applications such as
gaming, remote conferencing, social networking and virtual tourism. However, as
with any new consumer technology, VR applications also present significant
user-privacy challenges. This paper studies a new type of privacy attack
targeting VR users by connecting their activities visible in the virtual world
(enabled by some VR application/service) to their physical state sensed in the
real world. Specifically, this paper analyzes the feasibility of carrying out a
de-anonymization or identification attack on VR users by correlating visually
observed movements of users' avatars in the virtual world with some auxiliary
data (e.g., motion sensor data from mobile/wearable devices held by users)
representing their context/state in the physical world. To enable this attack,
this paper proposes a novel framework which first employs a learning-based
activity classification approach to translate the disparate visual movement
data and motion sensor data into an activity-vector to ease comparison,
followed by a filtering and identity ranking phase outputting an ordered list
of potential identities corresponding to the target visual movement data.
Extensive empirical evaluation of the proposed framework, under a comprehensive
set of experimental settings, demonstrates the feasibility of such a
de-anonymization attack
Evaluation of physicochemical properties and in-vitro release profile of glipizide-matrix patch
OBJECTIVES: The aim of the present investigation was to form matrix patches with ethyl cellulose (EC) as the base polymer, polyvinyl pyrrolidone (PVP) as the copolymer, plasticizer with dibutyl phthalate (DBP) or acetyl tributyl citrate (ATBC) and the drug glipizide (gz) by the solvent casting method. Physicochemical properties of the patches and in vitro drug release were determined in a modified Keshary-chien diffusion cell to optimize the patch formulations with the help of experimental data and figures for further studies. TECHNIQUES: EC and PVP of different proportions with different weight percentages of either DBP or ATBC and a fixed amount of glipizide were taken for matrix patch formations. The dried patches were used for measuring their drug contents as well as their thicknesses, tensile strengths, moisture contents and water absorption amounts in percentage. In vitro release amounts at different intervals were measured by UV-spectrophotometer. RESULTS: Drug contents varied from 96 - 99%. Thickness and tensile strength varied due to weight variation of the ingredients in the matrix patches. Moisture content and water absorption in wt % were greater for the patches containing higher amount of PVP due to its hydrophilic nature. Variations in drug release were observed among various formulations. It was found that all of the releases followed diffusion controlled zero order kinetics. Two DBP patches yielded better and more adequate release. CONCLUSIONS: The two formulations with DBP were the preferred choice for making matrix patches for further studies.O objetivo da presente pesquisa foi formar matrizes para bandagens de liberação transdérmica com etilcelulose (EC) como polímero base, polivinilpirrolidona (PVP), como copolímero, plastificante com ftalato de dibutila (DBP) ou citrato de tributilacetila (ATBC) e o fármaco glipizida (gz) pelo método de evaporação do solvente (moldagem com solvente). As propriedades físico-químicas das bandagens e a liberação do fármaco in vitro na célula de difusão de Keshary-chien modificada foram determinadas para aperfeiçoar as formulações das bandagens com o auxílio de dados experimentais e figuras para estudos posteriores. EC e PVP em diferentes proporções com porcentagens diferentes de massa tanto de DBP quanto de ATBC e quantidade fixa de glipizida foram utilizadas como matrizes para a formação de bandagens de liberação transdérmica. As bandagens secas foram empregadas para medir seus conteúdos em fármaco e, também, a sua espessura, resistência à tensão, conteúdos de umidade e porcentagem de absorção de água. As quantidades liberadas in vitro em diferentes intervalos de tempo foram medidas por espectrofotômetro de UV. Os conteúdos de fármaco variaram de 96 a 99%. A espessura e a resistência à ruptura variaram devido à variação de massa dos componentes da matriz das bandagens. O conteúdo de umidade e a água absorvida, em porcentagem de massa, foram maiores para as bandagens que continham grandes quantidades de PVP devido à sua natureza hidrofílica. As variações na liberação de fármaco foram observadas entre as várias formulações. Todas as liberações seguiram a cinética de difusão controlada de ordem zero. Duas bandagens DBP resultaram em melhor e mais adequada liberação. As duas formulações com DBP foram escolhidas para a preparação de matriz de bandagens para estudos posteriores
Binding of Nucleobases with Single-Walled Carbon Nanotubes
We have calculated the binding energy of various nucleobases (guanine (G),
adenine (A), thymine (T) and cytosine (C)) with (5,5) single-walled carbon
nanotubes (SWNTs) using ab-initio Hartre-Fock method (HF) together with force
field calculations. The gas phase binding energies follow the sequence G A
T C. We show that main contribution to binding energy comes from
van-der Wall (vdW) interaction between nanotube and nucleobases. We compare
these results with the interaction of nucleobases with graphene. We show that
the binding energy of bases with SWNTs is much lower than the graphene but the
sequence remains same. When we include the effect of solvation energy
(Poisson-Boltzman (PB) solver at HF level), the binding energy follow the
sequence G T A C , which explains the experiment\cite{zheng}
that oligonucleotides made of thymine bases are more effective in dispersing
the SWNT in aqueous solution as compared to poly (A) and poly (C). We also
demonstrate experimentally that there is differential binding affinity of
nucleobases with the single-walled carbon nanotubes (SWNTs) by directly
measuring the binding strength using isothermal titration (micro) calorimetry.
The binding sequence of the nucleobases varies as thymine (T) adenine (A)
cytosine (C), in agreement with our calculation.Comment: 7 pages, 6 figure
ADOBE Flash Lite â?? Based Online Laboratory for Mobile Phones
Recently, development of "Microelectronics and VLSI Engineering" Laboratory at IIT Kharagpur (http://lod.iitkgp.ernet.in/netlab), an innovative remote microelectronics device characterization and parameter extraction laboratory has been reported. The laboratory enables students to measure different semiconductor device characteristics and extract device parameters at any time and from anywhere using a Java-enabled web browser. Having pioneered the PC-based online laboratory to enhance microelectronics education, feasibility of use of mobile devices for hardware-based remote experimentation is explored. The work introduced in this paper is a prototype of the use of mobile devices in laboratory education