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The rational design of polymer nanocomposites with tailored multifunctional properties remains challenging due to complex multi-scale physics and the limitations of traditional empirical approaches, which cannot adequately capture the combinatorial interactions between polymer matrices, nanofillers, and processing conditions. We present a new computational framework for cost-effective virtual screening and optimization of polymer nanocomposites with physically consistent prediction in this series. In a physics-informed neural network, we suggest a combination of the quantum mechanical response, as well as standard molecular dynamics and thermodynamic data. (1) Physics-aware loss functions that incorporate conservation policies and thermodynamic constraints; (2) multiscale descriptor integration of quantum to macroscales; (3) ensemble learning is supplemented by tools to distinguish epistemic and aleatoric uncertainty; and (4) NSGA-III assisted multi-objective optimization coupled with adaptive reference point generation. The neural network architecture consists of multi-branch pathways with 5 hidden layers (256, 512, 512, 256, 128 neurons) using Leaky ReLU activation functions, trained on 23,847 polymer nanocomposite formulations using Adam optimizer (learning rate: 0.001, batch size: 64) with cosine annealing scheduling. The framework achieves prediction accuracies of R² > 0.94 for mechanical properties, R² > 0.91 for thermal characteristics, and R² > 0.88 for electrical conductivity, representing 15-25% improvements over conventional machine learning methods. Virtual screening of 3.2 million candidate formulations identified 1,847 compositions with superior performance. Our NSGA-III optimization identifies Pareto-optimal solutions with 34% higher multifunctional performance than conventional approaches, while reducing experimental validation requirements by 82%. Experimental validation of 127 compositions confirms 89% prediction accuracy within confidence intervals (95% confidence intervals: ±8.3% for mechanical, ±9.1% for thermal, ±11.2% for electrical properties). The present physics-informed machine learning approach enables computational materials design with accounting for the most relevant physical laws and data-driven techniques to discover optimal high-performance polymer nanocomposites yet offers a robust uncertainty quantification to inform risk-conscious design decisions.
Voice-selective sound processing, focusing specifically on the extraction of singular audio signals from multifaceted soundscapes, has rapidly gained prominence in a diverse range of applications from health diagnostics to contemporary smart home integrations. The pressing need for such precision extraction arises from our increasingly cluttered audio environments and the escalating importance of clean, distinct voice signals for efficient processing and analysis. The present research delves deep into the intricate mechanisms that drive voice-selective sound processing. By amalgamating the nuanced understanding of human auditory models with the prowess of cutting-edge machine learning methodologies, a unique framework is proposed. This innovative model promises a marked improvement in voice extraction capabilities even in environments characterized by high ambient noise levels. This paper further elucidates the key components of this system, offering insights into its potential and effectiveness in real-world applications.
In this chapter, we focus on the emerging area of tactile intelligence, in which AI algorithms learn to interpret and refine haptic feedback data with the goal of giving surgeons better tactile feeling in the operating theatre. This chapter discusses recent achievements in AI-based piezoelectric sensor systems and their use in laparoscopic and robotic surgery, fields where tactile feedback has been limited by traditional modalities. In this chapter highlights the key achievements of Machine learning models: a) improve real-time restoration of tactile sensation b) improve training protocols for surgical skills c) improve surgical performance metrics. This chapter also shows how these technologies will be implemented into conventional surgical education and clinical practice frameworks, addressing barriers to integration, current opportunities and outlook in this exciting new domain. Integrating AI with these haptic technologies, paves the way for more accurate and safer surgical approaches, leading to improved patient outcomes.
This work presents the efficacy of bismuth-based mixed oxide nanosructures for heavy metal ion detection. Four samples with varying proportions of Na3BiO4, Bi2O3 and Na2O were synthesized using potentiostatic electrodeposition. X-ray diffraction (XRD) indicates the presence of poly-crystalline Na3BiO4 and Na2O in sample 1 while presence of poly-crystalline Na3BiO4 and Bi2O3 were seen in samples 2 and 3. Poly-crystalline Bi2O3 was seen in sample 4. Scanning electron microscopy (SEM) showed the presence of microplates of varying shapes and sizes with an average thickness < 1µm. Linear stripping voltammetry confirms that Sample 2 shows highest sensitivity towards detection of heavy metal ions.
Chapter 1: Mobile Adaptive Computing Chapter 2: Mobility Management Chapter 3: Data Dissemination and Management Chapter 4: Context-Aware Computing Chapter 5: Introduction to Mobile Middleware Chapter 6: Middleware for Application Development: Adaptation and Agents Chapter 7: Service Discovery Middleware: Finding Needed Services Chapter 8: Introduction to Ad Hoc and Sensor Networks Chapter 9: Challenges Chapter 10: Protocols Chapter 11: Approaches and Solutions Chapter 12: Wireless Security Chapter 13: Approaches to Security Chapter 14: Security in Wireless Personal Area Networks Chapter 15: Security in Wireless Local Area Networks Chapter 16: Security in Wireless Metropolitan Area Networks (802.16) Chapter 17: Security in Wide Area Networks APPENDIX A: BRIEF INTRODUCTION TO WIRELESS COMMUNICATION AND NETWORKING APPENDIX B: QUESTIONS INDEX BIBLIOGRAPHY GLOSSARY REFERENCES
A healthy populace is essential for societal prosperity and well-being. This makes healthcare a basic societal necessity. Most societies endeavor to provide it in some form, usually in an organized manner through a system of medical facilities that are either private or public, or both. The current mode of delivering care relies on the patient initiating the care-delivery process. Figure 1.1 illustrates this model. It is a four-step process and requires the patient to observe the presence of specific symptoms, and visit a caregiver, who then diagnoses the problem and provides a treatment. We call this the traditional model of care delivery. The principal characteristic of the traditional model is that it is reactive in nature. No action is taken to improve the patient's condition unless the patient initiates the process. A problem with this approach is that it is inherently defensive in nature in fighting illness. This is particularly problematic if the symptoms for the patient's ailments seem benign or manifest late in the progression of the disease.
Mobile Ad Hoc Networks (MANETs) are composed of wireless mobile devices (nodes) equipped with portable radios but without the aid of any centralized management or existing infrastructure such as base-station. Broadcasting is an inevitable operation of route discovery Mobile Ad hoc Network (MANET). Though the broadcast by flooding is simple but inefficient and results in redundant message relays. This in turn over use of limited network resources like channel node energy and bandwidth. The normal flooding scheme is cause high retransmissions which lead to packet collisions and media congestion that can significantly degrade the network performance and throughput. Knowing the geographical position of the mobile nodes can help the protocol to reduce the number of retransmissions, thus enhancing the protocol performance. In this paper, an improved Flooding Algorithm has been proposed that makes use of the nodes' position to rebroadcast the packets and efficiently spread the control traffic in the mobile ad hoc network. The proposed algorithm is applied on the route discovery process of Ad-hoc On Demand Distance Vector (AODV) routing protocol to reduce the number of propagating Route Request (RREQ) messages. The RREQ has been customized by assigning a list to the RREQ contain fourth Nominated Neighbours to Rebroadcast the RREQ (NNRR) and used concept of requested zone and expected Zone to limit area of route discovery. The results produced by simulator shows that our scheme reduces the routing overhead and improves network throughput.
This paper describes an innovative wireless mobile robotics control system based on speech recognition, where the ESP32 microcontroller is used to control motors, facilitate Bluetooth communication, and deploy an Android application for the real-time speech recognition logic. With speech processed on the Android device and motor commands handled on the ESP32, the study achieves significant performance gains through distributed architectures while maintaining low latency for feedback control. In experimental tests over a range of 1–10 m, stable 110–140 ms command latencies, with low variation (±15 ms) were observed. The system’s voice and manual button modes both yield over 92% accuracy with the aid of natural language processing, resulting in training requirements being low, and displaying strong performance in high-noise environments. The novelty of this work is evident through an adaptive keyword spotting algorithm for improved recognition performance in high-noise environments and a gradual latency management system that optimizes processing parameters in the presence of noise. By providing a user-friendly, real-time speech interface, this work serves to enhance human–robot interaction when considering future assistive devices, educational platforms, and advanced automated navigation research.
(Received 3 1 May 1991; accepted for publication 23 September 1991) Epitaxial GaAs grown by molecular beam epitaxy (MBE) at low substrate temperatures is observed to have a significantly shorter carrier lifetime than GaAs grown at normal substrate temperatures. Using femtosecond time-resolved-reflectance techniques, a sub- picosecond ( ~0.4 ps) carrier lifetime has been measured for GaAs grown by MBE at -200°C and annealed at 600 “C. With the same material as a photoconductive switch we have measured electrical pulses with a full-width at half-maximum of 0.6 ps using the technique of electro-optic sampling. Good responsivity for a photoconductive switch is observed, corresponding to a mobility of the photoexcited carriers of - 120-150 cm”/V s. GaAs grown by MBE at 200 “C! and annealed at 600 “C is also semi-insulating, which results in a low dark current in the switch application. The combination of fast recombination lifetime, high carrier mobility, and high resistivity makes this material ideal for a number of . subpicosecond photoconductive applications. The development of ultrashort-pulse mode-locked la- ser systems has resulted in new techniques for the genera- tion and detection of picosecond and subpicosecond elec- trical transients. l-3 Among these, the use of semiconductor photoconductive switches are the most popular, because these devices can be used to efficiently generate signals and to generate and detect electrical transients in guided media or free space. Also, the semiconductor growth and process- ing techniques available for tailoring the properties of these materials enhance their versatility. The minimum attain- able electrical pulsewidth from a photoconductive element is limited by a number of factors such as the laser pulse- width, circuit parameters of the generation and detection site, and the carrier lifetime in the semiconductor. With the use of femtosecond lasers and photolithographically de- fined millimeter-wave co-planar structures, the limits to speed imposed by the first two factors can be reduced. To shorten the carrier lifetime of a semiconductor layer, im- purity doping of the semiconductor,4 growth of polycrys- talline or amorphous material,5 and damage by ion implantation6 can be used. Earlier we reported that photo- conductive switches based upon GaAs grown by molecular beam epitaxy (MBE) at low temperatures showed fast re- sponse (1.6 ps) and good responsivity in unoptimized structures.’ In this letter we extend our earlier study’ of the photoresponse of low-temperature (LT) GaAs using both a femtosecond transient reflectance technique and photo- conductive switching measurements. From both experi- ments we have observed a subpicosecond carrier lifetime for LT-GaAs grown at -200 “C. The 2+m-thick, (lOO)-oriented epitaxial tilrns dis- cussed here were grown by MBE at substrate temperatures of 400, 350, 300, 260,200, and 190 “C. For all the growths an As4 source was used, and the samples were mounted on the same MO block using In solder. The growth rate was 1.0 pm/h, and the As/Ga beam-equivalent-pressure ratio was 10. Pieces of the LT-GaAs samples were annealed inside the growth chamber under an As overpressure, just after the cmompletion of the growth, by raising the substrate temperature to 600 “C for 10 min. A number of papers have reported novel material properties of as-grown and annealed LT-GaAs layers, es- pecially those grown at -200 “C.“-” For photoconductive- switch applications, the most relevant properties of both as-grown and annealed 200 “C LT-GaAs are that the ma- terials are crystalline and yet contain a high density ( :> 10” cm 3 ) of point defects as As antisites, As inter- stitials, and Ga-related vacancies.“,” In addition to a high density of point defects, annealed 200 “C LT-GaAs grown in the Lincoln Laboratory MBE system also contains small ( < 5 nm) As precipitatesI at densities of -3~ lOI cm -3. The aforementioned point defects can act as recom- bination and trapping centers. Assuming simple Shockley- Read-Hall theory for the recombination mechanism of the photoexcited carriers, and using a density N- lOi cm ’ for the deep levels, a capture cross section u- lo- I3 cm2 (a typical value for deep levels in GaAs), and thermal velocity u,h at T = 300 K, we estimate that the carrier lifetime r = l/(Nmu,) in as-grown and annealed LT- GaAs to be less than 1 ps. Although as-grown LT-GaAs is relatively conducting (p- 10 s1 cm) at room temperature, annealed LT-GaAs is semi-insulating (p- 10’ fl cm).” Despite the high density of point defects and As precipitates, the Hall mobility at room temperature in annealed LT-GaAs is relatively high ( - 1000 cm”/V s).” Therefore, LT-GaAs grown at .- 200 “C and subsequently in situ annealed has the desired properties of a fast photoconductor; namely, a short carrier
An entry from the Cambridge Structural Database, the world’s repository for small molecule crystal structures. The entry contains experimental data from a crystal diffraction study. The deposited dataset for this entry is freely available from the CCDC and typically includes 3D coordinates, cell parameters, space group, experimental conditions and quality measures.
A network of biosensors can be implanted in a human body for health monitoring, diagnostics, or as a prosthetic device. Biosensors can be organized into clusters where most of the communication takes place within the clusters, and long range transmissions to the base station are performed by the cluster leader to reduce the energy cost. In some applications, the tissues are sensitive to temperature increase and may be damaged by the heat resulting from normal operations and the recharging of sensor nodes. Our work is the first to consider rotating the cluster leadership to minimize the heating effects on human tissues. We explore the factors that lead to temperature increase, and the process for calculating the specific absorption rate (SAR) and temperature increase of implanted biosensors by using the finite-difference time-domain (FDTD) method. We improve performance by rotating the cluster leader based on the leadership history and the sensor locations. We propose a simplified scheme, temperature increase potential, to efficiently predict the temperature increase in tissues surrounding implanted sensors. Finally, a genetic algorithm is proposed to exploit the search for an optimal temperature increase sequence.
An entry from the Cambridge Structural Database, the world’s repository for small molecule crystal structures. The entry contains experimental data from a crystal diffraction study. The deposited dataset for this entry is freely available from the CCDC and typically includes 3D coordinates, cell parameters, space group, experimental conditions and quality measures.
Severe energy constraints are one of the most serious concerns in WSNs. Because the performance of Sensor Networks is greatly influenced by network lifespan, researchers are looking for a strategy to better utilize node energy supply while also extending network lifetime. The weather where the sensors are placed, the routing methods, etc., all affect how much battery is used. Numerous quality of service (QoS) metrics are provided to gauge the network's performance and help reduce battery usage at the routing level. Many routing protocols have been proposed to address this issue. In this research, we analysed two low-power protocols—LEACH and Sub-cluster LEACH—and compared their performance. Levenberg-Marquardt neural networks (LMNNs) and Moth-Flame optimisation are both implemented one at a time to improve network performance. Energy efficiency, end-to-end latency, throughput, and packet delivery ratio (PDR) are some of the QoS indicators thought to assess performance. Sub-cluster LEACH with MFO was found to perform better than competing algorithms in post-implementation simulations. The simulation outcomes demonstrate that a suggested technique reduces energy consumption while extending life of WSNs.
Emerging technologies are always critical for the growth and development of human understanding. Biosensing is rapidly evolving and integrating with a number of existing technologies leading to the emergence of new set of tools that can redefine our society. New biosensing techniques are being developed that offer high sensitivity, selectivity and zero exposure to harmful radiations. Biosensors are revolutionizing the modern healthcare and diagnostics.
ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTBehavior of pure divalent bis(didodecyldimethylammonium)bis(4,5-dimercapto-1,3-dithiole-2-thionato)metalate complexes at the air-water interfaceS. K. Gupta, D. M. Taylor, P. Dynarowicz, E. Barlow, C. E. A. Wainwright, and A. E. UnderhillCite this: Langmuir 1992, 8, 12, 3057–3062Publication Date (Print):December 1, 1992Publication History Published online1 May 2002Published inissue 1 December 1992https://pubs.acs.org/doi/10.1021/la00048a035https://doi.org/10.1021/la00048a035research-articleACS PublicationsRequest reuse permissionsArticle Views55Altmetric-Citations27LEARN ABOUT THESE METRICSArticle Views are the COUNTER-compliant sum of full text article downloads since November 2008 (both PDF and HTML) across all institutions and individuals. These metrics are regularly updated to reflect usage leading up to the last few days.Citations are the number of other articles citing this article, calculated by Crossref and updated daily. Find more information about Crossref citation counts.The Altmetric Attention Score is a quantitative measure of the attention that a research article has received online. Clicking on the donut icon will load a page at altmetric.com with additional details about the score and the social media presence for the given article. Find more information on the Altmetric Attention Score and how the score is calculated. Share Add toView InAdd Full Text with ReferenceAdd Description ExportRISCitationCitation and abstractCitation and referencesMore Options Share onFacebookTwitterWechatLinked InRedditEmail Other access optionsGet e-Alertsclose Get e-Alerts
Abstract : One important activity for networked database systems that distribute data across several workstations is moving data between the file and network subsystems. It is possible to create data streams in the operating system kernel. If provided on a system, they allow user level processes to request transfer of data without having to copy it into the user space. This is particularly useful for data whose content or format is not modified during the transfer. In this paper we present a conservative criterion for access and control for the management of such data streams for databases in a networked environment, and define the implementation requirements for achieving the criterion. The approach is to maintain at least the current level of access management. We define the specific implementation semantics that this criterion entails.
Connectivity-based localization schemes compute the node positions using proximity information collected within the network. In many cases of practical interest, Received Signal Strength (RSS) measurements are available, and connectivity data can be obtained by comparing the RSS against a
The synthesized coordination polymer DMTD–Au has a layered structure, in which the layers are stacked <italic>via</italic> π–π stacking and hydrophobic interaction. It facilitates electron transfer kinetics, which has been utilized in the ultra trace sensing of resorcinol.
An entry from the Cambridge Structural Database, the world’s repository for small molecule crystal structures. The entry contains experimental data from a crystal diffraction study. The deposited dataset for this entry is freely available from the CCDC and typically includes 3D coordinates, cell parameters, space group, experimental conditions and quality measures.
Accurate localization of a seizure onset zone (SOZ) from independent components (IC) of resting-state functional magnetic resonance imaging (rs-fMRI) improves surgical outcomes in children with drug-resistant epilepsy (DRE). Automated IC sorting has limited success in identifying SOZ localizing ICs in adult normal rs-fMRI or uncategorized epilepsy. Children face unique challenges due to the developing brain and its associated surgical risks. This study proposes a novel SOZ localization algorithm (EPIK) for children with DRE.EPIK is developed in a phased approach, where fMRI noise-related biomarkers are used through high-fidelity image processing techniques to eliminate noise ICs. Then, the SOZ markers are used through a maximum likelihood-based classifier to determine SOZ localizing ICs. The performance of EPIK was evaluated on a unique pediatric DRE dataset (n = 52). A total of 24 children underwent surgical resection or ablation of an rs-fMRI identified SOZ, concurrently evaluated with an EEG and anatomical MRI. Two state-of-art techniques were used for comparison: (a) least squares support-vector machine and (b) convolutional neural networks. The performance was benchmarked against expert IC sorting and Engel outcomes for surgical SOZ resection or ablation. The analysis was stratified across age and sex.EPIK outperformed state-of-art techniques for SOZ localizing IC identification with a mean accuracy of 84.7% (4% higher), a precision of 74.1% (22% higher), a specificity of 81.9% (3.2% higher), and a sensitivity of 88.6% (16.5% higher). EPIK showed consistent performance across age and sex with the best performance in those < 5 years of age. It helped achieve a ~5-fold reduction in the number of ICs to be potentially analyzed during pre-surgical screening.Automated SOZ localization from rs-fMRI, validated against surgical outcomes, indicates the potential for clinical feasibility. It eliminates the need for expert sorting, outperforms prior automated methods, and is consistent across age and sex.
Abstract We describe a green photochemical route for the synthesis of gold nanoparticles (AuNPs) using phenothiazine (PTZH) as a reductant as well as a stabilizer without any extra control (i.e. surfactant, pH, etc.). The synthesized AuNPs are characterized by using UV/Vis spectroscopy, cyclic voltammetry, and transmission electron microscopy. Furthermore, a possible mechanism for the formation of the AuNPs is proposed. This hybrid electrode material, derived from nanoscale gold particles capped with PTZH and its oxidation product, is explored for the development of a highly sensitive amperometric sensor for phosphate ions. The electrochemistry behind the electrocatalytic sensing of phosphate is attributed to the nano‐sized gold particles that are capped with PTZH and its oxidation product, which exhibit high electron‐transfer kinetics through the interaction of the hybrid PTZH–AuNPs with oxygen atoms of ${{\rm{PO}}_4^{3 - } }$ . The modified electrode efficiently gives an electrochemical signature of phosphate ions at a potential of −0.336 V versus AgCl/Ag and shows a linear response toward phosphate sensing, with a sensitivity of 0.794 μA μ M −1 and a limit of detection of 0.022 μ m, at a signal‐to‐noise ratio of 3.
Localization is an essential service for many wireless sensor network applications. While several localization schemes rely on anchor nodes and range measurements to achieve fine-grained positioning, we propose a range-free, anchor- free solution that works using connectivity information only. The approach, suitable for deployments with strict cost constraints, is based on the neural network paradigm of self-organizing maps (SOM). We present a lightweight SOM- based algorithm to compute virtual coordinates that are effective for location-aided routing. This algorithm can also exploit the location information, if available, of few anchor nodes to compute absolute positions. Results of extensive simulations show improvements over the popular multi-dimensional scaling (MDS) scheme, especially for networks with low connectivity, which are intrinsically harder to localize, and in presence of irregular radio pattern or anisotropic deployment. We analytically demonstrate that the proposed scheme has low computation and communication overheads; hence, making it suitable for resource-constrained networks.
An entry from the Cambridge Structural Database, the world’s repository for small molecule crystal structures. The entry contains experimental data from a crystal diffraction study. The deposited dataset for this entry is freely available from the CCDC and typically includes 3D coordinates, cell parameters, space group, experimental conditions and quality measures.
Data intensive applications require massive data transfers between storage and processing units. VLSI scaling has increased the sizes of dynamic memories as well as speeds and capabilities of processing units to a point where, for many such applications, storage and computational processing capabilities are no longer the main limiting factors. Despite this fact, most current architectures fail to meet the performance requirements for such data intensive applications. In this paper, we describe a PIM architecture that harnesses the benefits of VLSI scaling to accelerate matrix operations that constitute the core of many data-intensive applications. We then present data partitioning and placement schemes that are efficient in terms of the computational complexities and internode communication cost. Such approaches are evaluated and analyzed under various computing environments. We also discuss on how to apply such partitioning and placement schemes to each matrix when chains of matrix operations are given as a task.
This paper introduces a core migration protocol that provides QoS for multicast applications in Mobile Ad hoc Networks. Multicasting is usually accomplished by constructing a multicast tree and transmitting the packets over this tree, replicating packets at the branch points. In a group shared multicast tree, the choice of the root (core) plays an important role in influencing the organization of the tree and affecting the performance of packet delivery. The objective is to construct a tree whose leaves achieve the desired qualities of the multicast application. Existing multicast routing protocols proposed for establishing and maintaining the groupshared tree, like CBT and PIM-SM, ignore the issues of core selection and migration, and are not QoS sensitive. We investigate an algorithm that migrates the core on a hop-by-hop basis to continuously adapt to the network dynamics; and whenever the topology remains constant for a sufficient duration, the core reaches an optimal position which corresponds to the specified QoS. Our algorithm is more practical for mobile ad hoc network environments than other protocols, since it does not rely on topology based metrics and has less overhead. This is accomplished by averaging the specified QoS metric using periodic QoS measurements for packets acknowledged at the current core. We present proofs of correctness to show that our algorithm moves the core toward an optimal position corresponding to the desired QoS. Our work also evaluates the performance of the core migration protocol through simulations.
Control affine assumptions, human inputs are external disturbances, in certified safe controller synthesis approaches are frequently violated in operational deployment under causal human actions. This paper takes a human-in-the-loop human-in-the-plant (HIL-HIP) approach towards ensuring operational safety of safety critical autonomous systems: human and real world controller (RWC) are modeled as a unified system. A three-way interaction is considered: a) through personalized inputs and biological feedback processes between HIP and HIL, b) through sensors and actuators between RWC and HIP, and c) through personalized configuration changes and data feedback between HIL and RWC. We extend control Lyapunov theory by generating barrier function (CLBF) under human action plans, model the HIL as a combination of Markov Chain for spontaneous events and Fuzzy inference system for event responses, the RWC as a black box, and integrate the HIL-HIP model with neural architectures that can learn CLBF certificates. We show that synthesized HIL-HIP controller for automated insulin delivery in Type 1 Diabetes is the only controller to meet safety requirements for human action inputs.
This chapter focuses on the various definitions, challenges, and approaches to BAN safety. Standard ISO 60601, a standard for medical devices, defines safety as the avoidance of unacceptable risks of hazards to the physical environment (i.e., to the patient) due to the operation of a medical device under normal or single-fault condition. Although this definition is akin to that for medical devices, it can be generally applicable to BANs as well, which are essentially networks of such devices. The standard further lists seven aspects of safety as follows.
This paper introduces a new quadruped spider robot platform specializing in environmental reconnaissance and mapping. The robot measures 180 mm × 180 mm × 95 mm and weighs 385 g, including the battery, providing a compact yet capable platform for reconnaissance missions. The robot consists of an ESP32 microcontroller and eight servos that are disposed in a biomimetic layout to achieve the biological gait of an arachnid. One of the major design revolutions is in the power distribution network (PDN) of the robot, in which two DC-DC buck converters (LM2596M) are used to isolate the power domains of the computation and the mechanical subsystems, thereby enhancing reliability and the lifespan of the robot. The theoretical analysis demonstrates that this dual-domain architecture reduces computational-domain voltage fluctuations by 85.9% compared to single-converter designs, with a measured voltage stability improving from 0.87 V to 0.12 V under servo load spikes. Its proprietary Bluetooth protocol allows for both the sending and receiving of controls and environmental data with fewer than 120 ms of latency at up to 12 m of distance. The robot’s mapping system employs a novel motion-compensated probabilistic algorithm that integrates ultrasonic sensor data with IMU-based motion estimation using recursive Bayesian updates. The occupancy grid uses 5 cm × 5 cm cells with confidence tracking, where each cell’s probability is updated using recursive Bayesian inference with confidence weighting to guide data fusion. Experimental verification in different environments indicates that the mapping accuracy (92.7% to ground-truth measurements) and stable pattern of the sensor reading remain, even when measuring the complex gait transition. Long-range field tests conducted over 100 m traversals in challenging outdoor environments with slopes of up to 15° and obstacle densities of 0.3 objects/m2 demonstrate sustained performance, with 89.2% mapping accuracy. The energy saving of the robot was an 86.4% operating-time improvement over the single-regulator designs. This work contributes to the championing of low-cost, high-performance robotic platforms for reconnaissance tasks, especially in search and rescue, the exploration of hazardous environments, and educational robotics.
An all-optical time-of-flight technique is used for measuring perpendicular carrier transport in semiconductor heterostructures and multiquantum wells (MQWs). This technique is based on measuring a change in surface reflectance due to the absorption nonlinearities induced by the carriers, and has a temporal resolution of ∼1 ps. Typical results on a GaAs/AlxGa1−xAs MQW and an In0.53Ga0.47As/In0.52Al0.48As MQW are compared. The observed fast transport times can only be explained by a field-dependent carrier emission out of the quantum well, after which transport through the continuum states can occur. Due to larger barriers in the In0.53Ga0.47As/In0.52Al0.48As system, this intrinsic limit to transport is much larger, and hence these devices are observed to be slower than their GaAs/AlxGa1−xAs counterparts.
: Electroencephalography (EEG) is crucial for diagnosing epilepsy by revealing brain electrical patterns. However, various artifacts like eye movements and muscle contractions can distort EEG data, making it difficult to detect seizures accurately. This study proposes an effective methodology to improve seizure detection and analysis by employing advanced feature extraction and principal component analysis (PCA) to reduce artifact impact, ultimately enhancing EEG interpretation and patient outcomes
Preliminary electrical characterization of Langmuir-Blodgett films formed from the didodecyldimethylammonium salt of Pt(DMIT)2 is reported. The in-plane conductivity of the films was found to be strongly voltage dependent for lateral electric fields in excess of about 10 kV m-1. In the ohmic low-field region of the characteristic the film conductivity was approximately 3*10-6 S m-1. Under vacuum, film conductivity decreased so much that the contribution of the film to the total current flow could not be distinguished from the parallel contribution through the glass substrate. This suggests strongly that atmospheric moisture and/or oxygen are implicated in the conduction mechanism of the undoped film. Exposure to bromine vapour led to an increase of about six orders of magnitude in the in-plane conductivity. However, when the bromine was replaced by air the conductivity quickly decreased to about 0.08 S m-1. Cycling the film temperature between 284 and 300 K gave rise to an unusual observation; the current decreased by several orders of magnitude as the temperature increased. The authors believe this to be associated with changes in film structure. The higher film conductance observed after bromine oxidation was completely lost when films were placed in vacuum, suggesting complete removal of bromine from the samples. The transverse conductivity of undoped films was between two and four orders of magnitude smaller than the in-plane conductance and depended on the type of electrodes used, namely gold, ITO glass or aluminium. Transverse measurements on bromine-doped films were deemed impractical because vacuum evaporation of the counter-electrode would have caused loss of bromine from the films.
Present intrusion detection systems rapidly monitor MANETs environment, which leads rapid depletion of battery life to address this issue we propose a novel intrusion detection system for detecting black hole attack and gray hole attack which is based on table driven approach or voting process in which routing propose we use Ad hoc on demand routing protocol and on the basis of behavior of node we compute the vote for node and negative voting trunk the node from path nodes create secure path using highest vote number, in this work simulation done on ns-2.35, result shows that network performance increase by proposed methodology.
An entry from the Cambridge Structural Database, the world’s repository for small molecule crystal structures. The entry contains experimental data from a crystal diffraction study. The deposited dataset for this entry is freely available from the CCDC and typically includes 3D coordinates, cell parameters, space group, experimental conditions and quality measures.
In this paper, we propose an approach to generate vectors that invoke high delays. We first identify properties of different types of paths, especially sticky paths, i.e., paths that are functionally sensitizable but not even non-robustly testable. In particular, we show that it is impossible to guarantee detection of sticky path-delay faults. We then identify logic and timing conditions that are necessary to cover a target path and develop a new logic-and-timing implication procedure to exploit these conditions. We incorporate this procedure in a new ATPG that also prioritizes the order in which these conditions are used to generate high quality vectors. We use this ATPG to identify paths that cannot or need not be tested and to generate high quality vectors for all other paths. Experimental results demonstrate that the vectors we generate invoke much higher delays than previously generated vector sets, especially for circuits with many sticky paths.
In this chapter, we focus on security for BANs. In particular, we present a new paradigm that uses environment coupling – a property inherent to BANs – for this purpose. However, before we delve into the details, we provide some general concepts and definitions pertaining to the notion of security, which we use throughout this chapter. Though the notion of security has many connotations, for the purposes of this book, we define it in the information-security context, as preventing unauthorized entities from viewing, accessing, or modifying data generated within a system. We use the term system in a generic sense to mean a computing system that takes an input, processes it, and provides an output.
Motion estimation is the most time consuming stage of MPEG family encodings and it reportedly absorbs up to 90% of the total execution time of MPEG processing. Therefore, we propose a hardware/software co-design paradigm that uses a PIM module to efficiently execute motion estimation operations. We use a PIM module to reduce the memory access penalty caused by a large number of memory accesses. We segment the PIM module into small pieces so that each smaller PIM module can execute the operations in parallel fashion. However, in order to execute the operations in parallel, there are critical overheads that involve replicating a huge amount of data to many of these smaller PIM modules. Not only do these replications require a huge amount of additional memory accesses but also calculations when generating addresses. Therefore, we also present an efficient data distribution mechanism to effectively support parallel executions among these smaller PIM modules. With our paradigm, the host processor can be relieved from computationally-intensive and data-intensive workloads of motion estimation. We observed up to 2034/spl times/ improvement in reduction of the number of memory accesses and up to 439/spl times/ performance improvement for the execution of motion estimation operations when using our computing paradigm.
Au–DTZH was synthesized by a one-step photochemical route and used for the amperometric sensing of thiocyanate. The modified electrode has a sensitivity of 16 nA nM<sup>−1</sup> and a limit of detection of 23.35 nM at a potential of 0.55 V <italic>vs</italic>. Ag/AgCl.
Images are the main source for all image-processing fields like surveillance, detection, recognition, and satellite. Good visibility of images captured by sensors becomes crucial for all computer vision tasks. Sometimes, the scene quality is degraded by bad weather conditions like haze, fog or smoke; therefore, making it difficult for the computer vision area to obtain actual information. Haze can be removed from a single input scene by using single image dehazing methods. Synthetic hazy images are created by a haze generator. Currently, most image dehazing techniques are applied for synthetic haze. Various single-image dehazing techniques are being developed and tested on real-world scenes captured in hazy environments using cameras. These techniques aim to be practical solutions for removing haze from images. This study focuses on dehazing methods for both synthetic and real datasets totaling 45 hazy scenes. The output qualities of different techniques are measured using different parameters, such as Ciede2000, Peak Signal to Noise Ratio (PSNR), and Structural Similarity Index Measure (SSIM).
We have measured the narrowest half-width at half-maximum photoluminescence linewidth of 2.8 meV, in 40-period lattice-matched In0.53Ga0.47As/In0.52Al0.48As multiple quantum wells, grown by molecular-beam epitaxy with growth interruption. A simple analysis of the linewidth suggests that the structure has near perfect interfaces. Temperature-dependent photoluminescence linewidth data indicate impurity incorporation due to the growth interruption. However, the high quality of the multiple quantum well is not impaired as is seen in the room-temperature absorption data, where excitonic features up to n=3 sublevel are clearly seen. Carrier lifetime in this multiple-quantum-well system has been measured, we believe for the first time, using the picosecond photoluminescence correlation technique. A lifetime of 860 ps is obtained, which is similar to the value obtained for high-quality GaAs/AlGaAs and In0.53Ga0.47As/InP quantum wells. This further confirms the high quality obtained in this ternary material system using growth interruption.
This study aimed to detect trace amounts of lead using Na3BiO4-Bi2O3 mixed oxide nanostructures. Scanning electron microscopy (SEM) showed the presence of nanoplates with an average thickness of 90 nm. X-ray diffraction (XRD indicated the presence of poly-crystalline Na3BiO4 and Bi2O3 in the ratio 1:4. The chemical structure of the prepared samples was also studied through X-ray photoelectron spectroscopy. These nanostructured electrodes are highly sensitive to Pb2+ ions with a limit of detection of 68 ppt (0.32 nM).
An entry from the Cambridge Structural Database, the world’s repository for small molecule crystal structures. The entry contains experimental data from a crystal diffraction study. The deposited dataset for this entry is freely available from the CCDC and typically includes 3D coordinates, cell parameters, space group, experimental conditions and quality measures.
Memories are significant proportions of most digital systems and memory-intensive chips continue to lead the migration to new nano-fabrication processes. As these processes have increasingly higher defect rates, especially when they are first adopted, such early migration necessitates the use of increasing levels of redundancy to obtain high yield (per area). We show that as we move into nanometer processes with high defect rates, the level of redundancy needed to optimize yield-per-area is sufficiently high so as to significantly influence design tradeoffs. We then report a first step towards considering the overheads of redundancy during design optimization by characterizing the tradeoffs between the granularity of a design and the level of redundancy that optimizes the yield-per-area of static RAMs (SRAMs). Starting with physical layouts of cells and the desired memory size, we derive probabilities of failure at a range of abstractions - transistor level, cell level, and system level. We then estimate optimal memory granularity, i.e., the size of memory blocks, as well as the optimal number of spare rows and columns that maximize yield-per-area. In particular, we demonstrate the non-monotonic nature of these tradeoffs and present efficient designs for large SRAMs. Our ongoing research is characterizing several other specific tradeoffs, for SRAMs as well as logic blocks.
In mobile ad-hoc network nodes communicate with each other or forward data by making route with the help of other nodes.Infrastructure of the network does not fix topology change due to movability of nodes that's why attacking condition in this network become high.There are lots of attacks for this network.In this paper we study about denial of service attack and its prevention and detection technique, in our propose work we give a novel solution to detect or prevent denial of service attack we implement our work in .Efficiency of our work we proof with the help of results.
Every well-known march test for memories was generated to efficiently achieve 100% coverage of a target set of fault types. The question we pursue is: What to do if 100% coverage of the given target set cannot be achieved under tight constraints on test cost? We first study an obvious option: Remove some fault types from the given target set until a new or well-known test can cover 100% of the remaining fault types under the given test cost constraint. We find that this approach leaves significant room for improvement. We then pursue a different option and develop a new method which uses the original target set of fault types and generates a march test that maximizes the fault coverage under the given tight constraint on test cost. Our method generates fault-coverage maximizing tests for a wide range of target sets of fault types. A comparison with well-known march tests with equal lengths demonstrates that our new march tests provide significantly higher coverage for various sets of fault types. Importantly, our new march tests provide graceful decrease in fault coverage as we tighten constraints on test length. Hence our method and new march tests enable tradeoffs between test quality and test cost and provide a new direction of memory test research focused on fault-coverage-maximization.
We explore the usage of large language models (LLM) in human-in-the-loop human-in-the-plant cyber-physical systems (CPS) to translate a high-level prompt into a personalized plan of actions, and subsequently convert that plan into a grounded inference of sequential decision-making automated by a real-world CPS controller to achieve a control goal. We show that it is relatively straightforward to contextualize an LLM so it can generate domain-specific plans. However, these plans may be infeasible for the physical system to execute or the plan may be unsafe for human users. To address this, we propose CPS-LLM, an LLM retrained using an instruction tuning framework, which ensures that generated plans not only align with the physical system dynamics of the CPS but are also safe for human users. The CPS-LLM consists of two innovative components: a) a liquid time constant neural network-based physical dynamics coefficient estimator that can derive coefficients of dynamical models with some unmeasured state variables; b) the model coefficients are then used to train an LLM with prompts embodied with traces from the dynamical system and the corresponding model coefficients. We show that when the CPS-LLM is integrated with a contextualized chatbot such as BARD it can generate feasible and safe plans to manage external events such as meals for automated insulin delivery systems used by Type 1 Diabetes subjects.
Gestures that share similarities in their forms and are related in their meanings, should be easier for learners to recognize and incorporate into their existing lexicon. In that regard, to be more readily accepted as standard by the Deaf and Hard of Hearing community, technical gestures in American Sign Language (ASL) will optimally share similar in forms with their lexical neighbors. We utilize a lexical database of ASL, ASL-LEX, to identify lexical relations within a set of technical gestures. We use automated identification for 3 unique sub-lexical properties in ASL- location, handshape and movement. EdGCon assigned an iconicity rating based on the lexical property similarities of the new gesture with an existing set of technical gestures and the relatedness of the meaning of the new technical word to that of the existing set of technical words. We collected 30 ad hoc crowdsourced technical gestures from different internet websites and tested them against 31 gestures from the DeafTEC technical corpus. We found that EdGCon was able to correctly auto-assign the iconicity ratings 80.76% of the time.
Yields for digital very-large-scale-integration chips have been declining in the recent years, and the decline is accelerating as the technology moves deep into nanoscale. Recently, we have proposed the notion of error tolerance to improve yields for a wide range of high-performance digital applications, including audio, speech, video, graphics, visualization, games, and wireless communication. Error tolerance systematically codifies the fact that chips used in such applications can be acceptable despite having defects that produce erroneous outputs, provided that the errors are guaranteed to be of certain types and have severities within thresholds specified by the application. In this paper, we propose a new testing approach called threshold testing to practically exploit the notion of error tolerance for applications where errors with absolute numerical magnitudes lower than an application-specified threshold are acceptable. We propose a new automatic test pattern generator (ATPG) for threshold testing for single stuck-at faults. This test generator embodies several completely new techniques, including new approaches for directing the search for a test vector, new types of objectives, new types of necessary conditions, and new approaches to identify and exploit these conditions. We demonstrate that threshold testing can enhance yield and that it is practical in terms of test generation effort and test application costs. We also propose threshold fault simulators and ATPG for bridging and transition delay faults. We use these tools to show that the stuck-at-fault model is indeed a suitable model for threshold testing. This opens the way for developing low-cost tools for threshold testing that will provide high threshold coverage for realistic faults and defects and hence help provide higher yields in future nanoscale processes at low costs.
An entry from the Cambridge Structural Database, the world’s repository for small molecule crystal structures. The entry contains experimental data from a crystal diffraction study. The deposited dataset for this entry is freely available from the CCDC and typically includes 3D coordinates, cell parameters, space group, experimental conditions and quality measures.
Hybrid nanomaterial (Ag–DTZH) derived from nanoscale silver protected with dithizone and its oxidation product for the electrosensing of cefotaxime (CFX), which is a third-generation cephalosporin antibiotic drug.
This paper presents a comprehensive study of an ESP32 microcontroller-based self-balancing mobile robot system designed in conjunction with an Android app for Bluetooth control. The robot employs an MPU6050 accelerometer/gyroscope to execute dynamic equilibrium control for robotic balance. This study explores the design of a system composed of an ESP32-based dual-platform architecture. The firmware for the ESP32 executes real-time motor control and sensor processing, while the Android application provides the user interface, data visualization, and command transmission. The system achieves stable operation with tilt angle variations of ±2.5° (σ=0.8°, n = 50 trials) during normal operation with a PID controller tuned to KP = 6.0, KI = 0.1, and KD = 1.5. In experimental tests, control latency was measured at 38–72 ms (mean = 55 ms, σ=12 ms) over distances of 1–10 m with a robust Bluetooth connection. Extended operational tests indicated the reliability of both autonomous obstacle avoidance mode and manual control exceeding 95%. Key contributions include gyro drift compensation using a progressive calibration scheme, intelligent battery management for operational efficiency, and a dual-mode control interface to facilitate seamless transition between manual and autonomous operation. Processing of real-time telemetry on the Android application allows visualization of important parameters like tilt angle, motor speeds, and sensor readings. This work contributes to a cost-effective mobile robotics platform (total cost: USD 127) through the provision of detailed design specifications, implementation strategies, and performance characteristics.
NAVIGATION is a quarterly journal published by the Institute of Navigation. The journal publishes original, peer-reviewed articles on all aspects of positioning, navigation, and timing. The journal also publishes selected technical notes and survey articles, as well as papers of exceptional quality drawn from the Institute's conference proceedings.
Measurement of the linear thermal expansion α has been carried out for Mn substituted YBa2(Cu1−xMnx)3Oy (0≤x≤2%) using a high resolution dilatometer over the temperature range 10–300 K. Across the superconducting transition, the jump in the coefficient of linear thermal expansion Δα was found to decrease with increasing Mn content. For the pure sample, we observed a negative jump. While a threefold decrease in Δα with x = 0.5% was observed, only slight changes in the oxygen content and transition temperature have been noted, as a function of the Mn concentration. The above observations clearly suggest that the substituent Mn is being incorporated into the superconductors as a whole and not in the form of a local cluster. Further, from the Ehrenfest relations, the pressure dependence of TC (dTC/dP) and the discontinuity in the compressibility, ΔK, are expected to decrease with the Mn concentration.
Abstract This work develops an efficient parameter estimation technique, based on manufacturer datasheet, to obtain unknown parameter of solar photovoltaic (PV), precisely. Firstly, a nonlinear least square objective function, in terms of variables given in manufacturer datasheet, has been developed. Then, two optimization techniques, namely the Particle Swarn Optimization (PSO) and Harmony Search (HS) are applied on the developed objective function to achieve the optimized result. Further, the correctness of the developed technique is tested by estimating the performance indices, namely percentage maximum power deviation index (%MPDI) and overall model deviation index (OMDI), of two different solar PV, viz., Kyocera KD210GH-2PU (poly-crystalline), and Shell SQ85 (mono-crystalline). It is shown that developed method with PSO outperforms the HS. The developed method with PSO gives the values of %MPDI and OMDI of 0.0214% and 0.213, only. Also, the existing methods, based on hybrid, multi-objective function, numerical method, have been considered for the comparative analysis. It is revealed through the comparative studies that the developed method with PSO has smaller value of MPDI (= 0.0041%) and OMDI (0.005) than the other existing methods. Further, the convergence of the developed method has also been estimated to check the speed of estimation. It is shown that the developed technique converges only in 5 s. In addition, the developed technique avoids the need of extensive data as it is based on manufacturer datasheet.
This paper presents a novel framework addressing the fundamental challenge of concurrent real-time audio acquisition and motor control in resource-constrained mobile robotics. The ESP32-based system integrates a digital MEMS microphone with rover mobility through a unified Bluetooth protocol. Key innovations include (1) a dual-thread architecture enabling non-blocking concurrent operation, (2) an adaptive eight-bit compression algorithm optimizing bandwidth while preserving audio quality, and (3) a mathematical model for real-time resource allocation. A comprehensive empirical evaluation demonstrates consistent control latency below 150 ms with 90–95% audio packet delivery rates across varied environments. The framework enables mobile acoustic sensing applications while maintaining responsive motor control, validated through comprehensive testing in 40–85 dB acoustic environments at distances up to 10 m. A performance analysis demonstrates the feasibility of high-fidelity mobile acoustic sensing on embedded platforms, opening new possibilities for environmental monitoring, surveillance, and autonomous acoustic exploration systems.
Haptic technology has transitioned from basic mechanical feedback to intelligent, adaptive systems powered by artificial intelligence (AI), brain-computer interfaces (BCIs), and neuro feedback. This paper provides a detailed exploration of how these advancements are revolutionizing haptic interactions in gaming, healthcare, rehabilitation, and virtual reality (VR). We examine AI-driven adaptive haptics that learn from user behaviour, BCIs that enable direct neural control of tactile feedback, and neuro feedback-integrated systems that respond to users' emotional and physiological states. Ethical considerations, challenges, and future research directions are also discussed.
