Application Layer Research Articles

CRS: A Privacy-Preserving Two-Layered Distributed Machine Learning Framework for IoV

Nowadays, vehicles can provide many valuable data (such as the videos recorded by dashcams) for analytical model building. Integrating vehicular ad-hoc networks with Internet of Things (IoT), Internet of Vehicles (IoV) has a promising future. In IoV, vehicles maintain their own communication, computing, and learning capabilities. Thus, instead of sending the data to a central server for model training, which leads to a high communication overhead, vehicles can train the data locally. However, it is still a challenge to preserve the privacy while keeping both the communication and computation overheads of vehicles acceptable. In this paper, we present a distributed machine learning framework with a two-layered architecture. The architecture uniquely involves vehicle clusters, road-side units, and a central server, which provides a basic guarantee to the vehicle privacy and also limits the overhead. By carefully adopting cryptographic tools and techniques, the framework has the following properties: 1) it preserves the privacy of the local inputs and model weight vectors to all parties; 2) it protects the identities and trajectories of vehicles; 3) packet loss is handled in the application layer; 4) the evaluation shows that it is lightweight for vehicles. Compared with other existing works, the proposed framework is more suitable for IoV.

Використання блокчейну першого рівня LTO Network для автоматизації міжорганізаційних бізнес-процесів

The article is devoted to the consideration of blockchain technology as a means of automating inter-organizational business processes. It is noted that the digitalization and automation of internal business processes bring significant benefits in terms of increasing productivity and reducing costs. However, organizations face difficulties when trying to obtain such benefits for inter-organizational processes, partly due to a lack of trust. This paper considers a blockchain approach to address this problem. Bitcoin has demonstrated how blockchain can provide a distributed system without the need for trust through cryptography and decentralization. LTO extends this approach with a decentralized workflow engine for ad-hoc collaboration. Information is exchanged between participants through private event chains for each process and hashed on a public blockchain. This hybrid approach allows organizations to comply with data protection requirements and avoid scalability issues typical of blockchain projects. The advantages of LTO live contracts over Ethereum smart contracts are discussed. Live contracts do not contain values directly, but describe the interaction between the parties, unlike the cryptographic "boxes" of smart contracts. Modeling live contracts as finite state machines allows visualizing them in the form of a flowchart. Alternative modeling techniques such as Petri nets and BPMN are discussed. The article describes a scenario-based approach to defining a workflow containing states, actions, participants, assets, and embedded data objects. The features of data objects, participant identifiers, process execution and its adaptability are detailed. The author explains the operation of a private event chain as an ad-hoc private blockchain that ensures the consistency of the process state between nodes. Methods of ensuring data privacy are discussed. The second part of the article is devoted to the global public blockchain LTO to confirm information from private event chains. The consensus algorithm is explained based on the importance of token ownership and its use to prevent abuse. Optimizations, such as the NG protocol and aggregation blocks, are discussed to scale with a large number of transactions. The last part describes the architecture of the platform and its components: microservices, application layers, container orchestration. The platform makes it easy to digitalize and automate inter-organizational interactions using live contracts on the blockchain.

Preparation of nanostructured cuprous oxide (Cu2O) absorber layer for photovoltaic application

AbstractIn this investigation, a nanostructured Cu2O thin film absorber layer is electrodeposited, exploring the impact of varying negative applied voltages and deposition time. Notably, the Cu2O thin film demonstrated optimal absorbance at −0.95 V, contrasting sharply with a minimum at −0.97 V. The authors' findings underscore that the peak absorbance was achieved at −0.95 V, coinciding with the lowest transmittance observed after 80 min of deposition, aligning with a maximal absorption coefficient of 21 × 103 cm−1. At a deposition time of 5 min, the Cu2O thin film exhibited a noteworthy maximum Urbach energy of 2.00 eV and a minimum steepness parameter of 0.013. In contrast, the lowest Urbach energy was recorded at 0.34 eV, with the highest steepness parameter occurring at an applied voltage of 0.93 V. Furthermore, this study revealed a gradual increase in the refractive index with higher applied voltages, reaching its pinnacle at −1.5 V. These results collectively emphasize the nuanced interplay between applied voltage, deposition time and the optical properties of the nanostructured Cu2O thin film. The observed trends hold significant implications for optimizing the performance of thin film absorber layers, particularly in the context of enhancing absorbance and tailoring optical characteristics for specific applications.

Thermally deposited copper(I) thiocyanate thin film: An efficient and sustainable approach for hole transport layer in perovskite solar cells

Solution-processable deposition of copper(I) thiocyanate (CuSCN) thin films have been widely used as hole transport layer (HTL) in optoelectronic applications, namely perovskite and organic solar cells. Herein, we report thermally...

Surface-assisted synthesis of perovskite nanosheets with bivalent aromatic cations

Halide perovskites have attracted significant attention as cutting-edge semiconducting materials, particularly as ultrathin layers for optoelectronic applications.

XOR count and block circulant MDS matrices over finite commutative rings

<p>Block circulant MDS matrices are used in the design of linear diffusion layers for lightweight cryptographic applications. Most of the work on construction of block circulant MDS matrices focused either on finite fields or $ GL(m, \mathbb{F}_2) $. The main objective of this paper is to extend the above study of block circulant MDS matrices to finite commutative rings. Additionally, we examine the behavior of the XOR count distribution under different reducible polynomials of equal degree over $ \mathbb{F}_2 $. We show that the determinant of a block circulant matrix over a ring can be expressed in a simple form. We construct $ 4 \times 4 $ and $ 8 \times 8 $ block circulant matrices over a ring. Furthermore, for non-negative integer $ l $, we identify the conditions under which a ring $ \mathfrak{R}_l = \frac{\mathbb{F}_2[x]}{\langle (f(x))^{2^l} \rangle} $, contains a finite field of order $ 2^m $, where $ f(x) $ is an irreducible polynomial of degree $ m $. To facilitate efficient implementation, we analyze XOR distributions within specific rings, such as $ R_1 = \frac{\mathbb{F}_2[x]}{\langle (1+x^2+x^6) \rangle} $ and $ R_2 = \frac{\mathbb{F}_2[x]}{\langle (1+x^4+x^6) \rangle} $. Our calculations reveal distinct XOR distributions when utilizing two reducible polynomials of equal degree, with XOR count distributions 776 and 764, respectively. However, when using irreducible polynomials of the same degree, the XOR count distributions remain the same. This difference is advantageous for applications in lightweight cryptography.</p>

In situ fabrication of self-filtered near-infrared Ti3C2Tx/n-Si Schottky-barrier photodiodes for a continuous non-invasive photoplethysmographic system.

Two-dimensional (2D) MXenes have emerged as promising candidates to serve as Schottky contact electrodes for the development of high-performance photodiodes owing to their extraordinary electronic properties. However, it remains a formidable challenge to fabricate a large-area, uniform MXene layer for practical device application. Here, we develop a facile route to produce a large-area Ti3C2Tx layer by post-etching treatment of a pulsed laser-deposited Ti3AlC2 film, enabling the in situ construction of a back-illuminated Ti3C2Tx/n-Si Schottky-barrier photodiode. Significantly, the device exhibits excellent performance with a distinctive self-filtered near-infrared (NIR) photoresponse behavior in the range of 700-1100 nm. By avoiding disturbances caused by ambient light, the NIR photodiode-based transmission-type photoplethysmographic (PPG) measurement system is capable of more reliable detection of PPG waveforms than the commercial PPG sensors for continuously monitoring heart rate. This enables the accurate extraction of blood pressures using a PPG-only method. Our findings not only pave the way for fabrication of a high-quality large-area 2D MXene layer, but also provide a general design principle for developing high-performance MXene/Si photodiodes for health monitoring systems.

Colloidal spherical stibnite particles via high-temperature metallo-organic synthesis.

Antimony trisulfide (Sb2S3) is an emerging semiconductor with a high absorption coefficient and a bandgap in the visible range. This makes it a promising material for various electronic and optoelectronic applications. However, one of the main challenges is still the synthesis of the material, as it is usually obtained either as a nanomaterial in its amorphous form with inferior optical properties or in crystalline rod-like structures in the micrometer or sub-micrometer range, which leads to application-related difficulties such as clogging in inkjet printing or spraying processes or highly porous layers in film applications. In this study, a one-pot synthesis of highly crystalline, spherical Sb2S3 sub-micron particles is presented. The particles are growing encapsulated in a removable, wax-like matrix that is formed together with an intermediate from the precursors SbCl3 and l-cysteine. Both substances are insoluble in the reaction mixture but well-dispersable in the solvent 1-octadecene (ODE). The intermediate forms a complex crosslinked architecture whose basic building block consists of an Sb atom attached to three cysteine molecules via Sb-S bonds. Embedded in the matrix consisting of excess cysteine, ODE, and chlorine, the intermediate decomposes into amorphous Sb2S3 particles that crystallize as the reaction proceeds at 240 °C. The final particles are highly crystalline, spherical, and in the sub-micron range (420 ± 100 nm), making them ideal for further processing. The encapsulation method could not only provide a way to extend the size range of colloidal particles, but in the case of Sb2S3, this method circumvents the risk of carbonization of ligands or insufficient crystallization during the annealing of amorphous material.

High-energy sputtering for the deposition of a conductive and adherent single molybdenum layer for solar cell applications

Molybdenum (Mo) thin films are thought to be an excellent back contact for CuIn1-xGaxSe2 (CIGS) solar cells. Mo films require high conductivity and good adhesion to glass substrates; however, these characteristics cannot be combined in sputtered Mo under the same deposition conditions. Direct current Magnetron Sputtering (DcMS) and High-Power Impulse Magnetron Sputtering (HiPIMS) were used to deposit Mo films on glass substrates, and the effects of working pressure and substrate bias on their characteristics were investigated. To begin, single layers of Mo were produced at pressures ranging from 0.2 to 1.4 Pa. The Mo films deposited at the lowest working pressure of 0.2 Pa were then subjected to a negative substrate bias varying from -50 to -200 V. All of the HiPIMS films adhered well to the glass substrate, whereas the DcMS films deposited at various pressures showed poor adhesion. Furthermore, our findings demonstrated that applying a negative substrate bias reduced the resistivity of Mo films to the lowest values of 2.56 × 10−5 Ω.cm and 2.771 × 10−5 Ω.cm, respectively, for the HiPIMS and DcMS-deposited films, while improving the adhesion of the DcMS-samples due to the development of films with homogenous stress distribution.

The effect investigates of temperature on the optical and electrical properties of sprayed SnS: experimental and theoretical study

In this study, Tin monosulfide SnS semiconductor absorbers was deposited by chemical spray pyrolysis route on the glass substrate. We examined the impact of substrate temperature on the structural, morphological, linear optical and electrical characteristics of SnS absorber at many substrate temperatures such as 50 °C, 375 °C and 400 °C. The SnS films have been analysed by diverse techniques like X-ray diffraction, Raman spectroscopy, Scanning electron microscopy and UV-Vis spectrophotometer. The X-ray diffraction (XRD) spectra revealed that the SnS crystallize in the orthorhombic crystal system with the apparition of the preferential crystallographic direction oriented along (111) planes. The SEM micrographs indicate a great uniformity and granular morphological surface of SnS films. Linear optical constants such as energy gap (Eg), coefficient of extinction (k), index of refraction (n), optical conductivity (σopt), as well as the electrical properties confirm the suitable application of SnS thin films as absorber layer in the optoelectronic device applications. Additionally, we have applied the density functional theory DFT and GGA generalized gradient approximation to study the electronic characteristics; as a result of the electronic band structure the SnS absorber has a suitable energy gap.

Rational ligand design for enhanced carrier mobility in self-powered SWIR photodiodes based on colloidal InSb quantum dots.

Solution-processed colloidal III-V semiconductor quantum dot photodiodes (QPDs) have potential applications in short-wavelength infrared (SWIR) imaging due to their tunable spectral response range, possible multiple-exciton generation, operation at 0-V bias voltage and low-cost fabrication and are also expected to replace lead- and mercury-based counterparts that are hampered by reliance on restricted elements (RoHS). However, the use of III-V CQDs as photoactive layers in SWIR optoelectronic applications is still a challenge because of underdeveloped ligand engineering for improving the in-plane conductivity of the QD assembled films. Here, we report on ligand engineering of InSb CQDs to enhance the optical response performance of self-powered SWIR QPDs. Specifically, by replacing the conventional ligand (i.e., oleylamine) with sulfide, the interparticle distance between the CQDs was shortened from 5.0 ± 0.5 nm to 1.5 ± 0.5 nm, leading to improved carrier mobility for high photoresponse speed to SWIR light. Furthermore, the use of sulfide ligands resulted in a low dark current density (∼nA cm-2) with an improved EQE of 18.5%, suggesting their potential use in toxic-based infrared image sensors.

RESEARCH OF CYBER SECURITY TECHNOLOGIES OF CLOUD SERVICES IAAS, PAAS AND SAAS

Cybersecurity threats are constantly evolving, and cloud computing is no exception. Attackers are improving attack techniques aimed at identifying vulnerabilities in IaaS, PaaS, and SaaS. The work examines the following problematic issues: insufficient analytical tools; data privacy and security; financial and organizational costs to ensure cyber security of IaaS, PaaS and SaaS cloud technologies. The aim of the work is to investigate how the common models of cloud computing: infrastructure as a service (IaaS), platform as a service (PaaS) and software as a service (SaaS) need to properly implement adequate and appropriate protection measures to ensure cyber security. For this purpose, the paper examined models of cloud technologies, it was determined that cloud services include various models that allow users to access various types of resources via the Internet. It has been found that there are three generally accepted models of cloud services: infrastructure as a service (IaaS), platform as a service (PaaS) and software as a service (SaaS), and two main players: the cloud provider and the cloud subscriber. The set of levels over which each of these players has control depends on the model of the cloud service or environment. For each of these cloud services, its description was given, recommendations were given for access control, privacy assurance, terms of use were defined, advantages and disadvantages were given, and market trends of these services were considered. Proposed approaches to the formation of a secure application development environment in cloud services. Features such as wide network access, resource pooling, fast elasticity, service metering, and data sharing are also summarized. Guidelines for designing access control for IaaS, PaaS, and SaaS according to their different characteristics are proposed. In addition, the security policy rules for each cloud system are summarized. Technologies are proposed to protect security at each of the three main layers of cloud services: the application, middleware, and virtual machine layers, due to differences in the organization that controls each of these layers. It was found that for any level it is possible to provide more effective protection if the same subject controls the level below. Since the network, hardware, and resource abstraction layer in all cloud service models are controlled by the cloud provider, it has more effective protections at its disposal.

A single-electrode mode triboelectric nanogenerator based on natural leaves for harvesting energy

This work reports a single-electrode mode triboelectric nanogenerator (G-TENG) based on natural leaf as the friction layer for application in the field of outdoor self-power supply.

The Construction of Digital Management Platform for Civic and Political Education for Future College Education and Its Intelligent Teaching Practice

Abstract Civic education in colleges and universities is facing the transformation of digital management mode, and this paper proposes to build a whole-process autonomous multi-dimensional fusion platform for the implementation and management of civic education in colleges and universities. The platform takes the big data analysis layer, object application layer and service management layer as the overall structure, builds the dynamic database of the Civic and Political Education program, and superimposes the tripartite comprehensive evaluation database. This paper improves the Apriori algorithm for association rules and applies the improved algorithm to the management platform for information mining. Intelligent teaching practices are designed based on the digital management platform, and their teaching effectiveness is analyzed. The performance of the Apriori algorithm before and after optimization is compared, and with the optimized algorithm, the execution efficiency is improved by about 10% to 15%. Students using the Civics education platform showed significant differences at the 1% level in all three dimensions of cognitive load, learning motivation, and mind-flow experience compared to students in the traditional teaching mode.

LSTM-Based Jamming Detection and Forecasting Model Using Transport and Application Layer Parameters in Wi-Fi Based IoT Systems

LSTM-Based Jamming Detection and Forecasting Model Using Transport and Application Layer Parameters in Wi-Fi Based IoT Systems

Unknown application layer protocol recognition method based on deep clustering

Unknown application layer protocol recognition method based on deep clustering

MU-IoT: A New IoT Intrusion Dataset for Network and Application Layer Attacks Analysis

MU-IoT: A New IoT Intrusion Dataset for Network and Application Layer Attacks Analysis

Securing the IoT Application Layer From an MQTT Protocol Perspective: Challenges and Research Prospects

Securing the IoT Application Layer From an MQTT Protocol Perspective: Challenges and Research Prospects

Enhancing Cloud Security through Intrusion Detection: A Comprehensive Study Using the ISOT-CID Dataset

Cloud computing has revolutionized data management, offering unparalleled scalability, flexibility, and efficiency. However, its open and multi-tenant nature introduces significant security vulnerabilities, making it an attractive target for cyber threats. Intrusion Detection Systems (IDS) tailored for cloud environments are essential in mitigating these risks. Despite various IDS models, benchmarking datasets representing realistic cloud environments is a substantial limitation. This study utilizes the ISOT Cloud Intrusion Detection Benchmark Dataset (ISOT-CID), a publicly available dataset featuring a range of network and application layer attacks collected from a real production cloud environment. The research explores the dataset's structure, analyzes attack patterns, and evaluates IDS models' performance to provide actionable insights for enhancing cloud security. This work contributes to the field by presenting a systematic analysis of ISOT-CID, identifying effective IDS models, and proposing improvements for future cloud intrusion detection research.

Holistic Survey on Security in IoT Application Layer: Attacks, Protocols, and Applications

Holistic Survey on Security in IoT Application Layer: Attacks, Protocols, and Applications