Minimum Delay Time Research Articles

Connecting Cities: A Case Study on the Application of Morphological Shortest Paths

Navigatingdensely connected networks can be complex due to the different connection structures present within a network. No explicit algorithms are designed specifically for this navigation, so heuristic approaches and existing network systems are often employed. However, this task can become computationally asymmetrical, as the complexity of creating a representation of the city is lower than the complexity involved in identifying a set of feasible paths in a combinatorial order. This paper extends the applicability of morphological approaches to compute the shortest path in smart cities, driven by the complexity and size of the vital communication infrastructure. As is well known, this communication infrastructure changes dynamically, particularly with the evolving connection paths due to continuous population growth. Consequently, efficient communication trajectories can quickly become obsolete. The challenge of computing the best trajectories to respond more quickly to the growing population comes with high computational complexity. This paper presents an application that uses a discrete algorithm designed to compute the shortest path through a morphological approach. Specifically, it seeks to identify the best trajectory within a densely populated city based on a complex density graph. By incorporating morphological approaches into path-search algorithms, we can define a new family of methods that operate in discrete spaces with a morphological representation, resulting in approaches that have lower computational requirements. Other well-known applications in this context include the delivery of resources, such as managing electrical power consumption or minimizing time delays in resource delivery. This task is essential but classified as an NP problem, making it an appropriate scenario for applying the proposed algorithm to navigate a dense graph. The paper highlights the well-known problem of finding the shortest path as one of the potential applications of the introduced algorithm. The algorithm aims to identify the optimal path trajectory within a graph representing a dense city’s real scenario. This discussion compares and contrasts the proposal with other established approaches, highlighting the advantages and characteristics of the proposed method.

Effect of SnO2 Nanoparticles Content on Ignition and Combustion Performance of Boron Particles

Abstract Boron is a potential metallic fuel substitute for solid propellant, however, its application has been limited by the surface oxide layer. Metal oxide are proposed to improve its oxidation performance. In the paper, boron particles were coated with SnO2 nanoparticles (n-SnO2) by a hydrothermal method. The B@SnO2 particles were characterized by SEM, TEM, and XRD. The results show that the boron particles were uniformly coated with n-SnO2 with range from 5 nm to 20 nm. The thermal oxidation, ignition and combustion performances were characterized by using TG-DSC, oxygen bomb calorimeter and laser ignition testing system. The relationship between the content of SnO2 and the performance of ignition and combustion were established. Significant reduction of oxidation temperature of boron particles was observed after coating with n-SnO2. The effect was more obvious with increasing SnO2 content. Furthermore, with the increase of SnO2 content, the ignition delay time of B@SnO2 particles decrease, its heat of combustion and combustion efficiency first increase then decreases gradually. Compared with boron particles, the maximum combustion efficiency of B@SnO2 particles reaches to 86.03%, increased by 57.19%, and the minimum ignition delay time reaches to 8 ms, decreased by 46.7%. Therefore, the coating significantly reduced ignition temperature and increased heat, and the particles has profound application potential as the solid fuel.

Precise fabrication and superior combustion properties of n-B pomegranate microspheres based on a new dissolution-dispersion-coating method

To enhance the reactivity and combustion efficacy of boron powder, a new dissolution-dispersion-coating (DDC) method for fabricating nano-boron (n-B) pomegranate microspheres was developed. Metal nanoparticles were uniformly encapsulated by n-B microspheres, which were varied in the size from 2 to 500 μm. The spheroidization mechanism of microsphere structure was analyzed. Subsequently, the ignition and combustion performance of the prepared pomegranate microspheres were evaluated by combustion test at 0.2 and 0.5 MPa, respectively. The results demonstrated that the n-B microspheres of F5 (75 wt% n-B@17 wt% NC@8 wt% n-Ti) exhibited superior performance, achieving the largest flame area, minimal ignition delay time and combustion time. The combustion thermal value and combustion residue analysis indicated that the content of available boron in the F5 microspheres exceeded 72.6 % and the combustion was complete. This study provides a novel approach to enhance the ignition and combustion efficiency of n-B powders.

A Review of Algorithms and Platforms for Offloading Decisions in Mobile Cloud Computing

With the substantial growth of mobile applications and the emergence of cloud computing concepts, therefore mobile Cloud Computing (MCC) has been introduced as a potential mobile service technology. Mobile has limited resources, battery life, network bandwidth, storage, and processor, avoid mobile limitations by sending heavy computation to the cloud to get better performance in a short time, the operation of sending data, and get the result of computation call offloading. In this paper, a survey about offloading types is discussed that takes care of many issues such as offloading algorithms, platforms, metrics (that are used with this algorithm and its equations), mobile cloud architecture, and the advantages of using the mobile cloud. The trade-off between local execution of tasks on end-devices and remote execution on the cloud server for minimizing delay time and energy saving. In the form of a multi-objective optimization problem with a focus on reducing overall system power consumption and task execution latency, meta-heuristic algorithms are required to solve this problem which is considered as NP-hardness when the number of tasks is high. To get minimum cost (time and energy) apply partial offloading on specific jobs containing a number of tasks represented in sequences of zeros and ones for example (100111010), when each bit represents a task. The zeros mean the task will be executed in the cloud and the ones mean the task will be executed locally. The decision of processing tasks locally or remotely is important to balance resource utilization. The calculation of task completion time and energy consumption for each task determines which task from the whole job will be executed remotely (been offloaded) and which task will be executed locally. Calculate the total cost (time and energy) for the whole job and determine the minimum total cost. An optimization method based on metaheuristic methods is required to find the best solution. The genetic algorithm is suggested as a metaheuristic Algorithm for future work.

The Rise of the r-process in the Gaia-Sausage/Enceladus Dwarf Galaxy ∗

Neutron star mergers (NSMs) produce r-process elements after a time-delayed inspiral process. Once a significant number of NSMs are present in a galaxy, r-process elements, such as Eu, are expected to significantly increase with time. Yet, there have been limited observational data in support of Eu increasing within Local Group galaxies. We have obtained high-resolution Magellan/MIKE observations of 43 metal-poor stars in the Gaia-Sausage/Enceladus (GSE) tidally disrupted galaxy with −2.5 < [Fe/H] < −1. For the first time, we find a clear rise in [Eu/Mg] with increasing [Mg/H] within one galaxy. We use a simple chemical evolution model to study how such a rise can result from the interplay of prompt and delayed r-process enrichment events. Delayed r-process sources are required to explain the rise and subsequent leveling off of [Eu/Mg] in this disrupted galaxy. However, the rise may be explained by delayed r-process sources with either short (∼10 Myr) or long (∼500 Myr) minimum delay times. Future studies on the nature of r-process sources and their enrichment processes in the GSE will require additional stars in the GSE at even lower metallicities than the present study.

Human-in-the-loop control of dynamics and robotics using augmented reality

Human-machine interaction (HMI) and human-robot interaction (HRI) offer innovative approaches for the analysis of structural dynamics both in laboratory and real-world scenarios. In vibratory experimentation, an external force is generated to evaluate dynamic responses of structures. One mode of generation is to use electrodynamic shakers. Sensors are attached to the structure to measure dynamic responses and can be deployed by robots. In post-disaster inspections robotic deployment ensures the safety of inspectors and requires control. If the interface between operators and the controls was augmented, then operators can visualize experiments, exciter levels, and define robot input while maintaining awareness of the area of interest. Robots can provide better aid to humans if control of the robot is: (1) quantified and presented to the human; and (2) conducted in real-time for human feedback. This research proposes using Augmented Reality (AR) to provide operators with sensor feedback and control for analysis of dynamic structures with robots. This method improves cognition by allowing the operator to maintain awareness of structures while adjusting conditions accordingly with the assistance of the new real-time interface. One interface application is developed to plot sensor data in addition to voltage, frequency, and duration controls for vibration simulations. Two more applications are developed following the same framework, one to control the position of a mediating robot and one to control the frequency of the robot's movement. The applications serve as a first-step approach investigating potential robotic sensor deployment in disaster assessment of structures. This paper presents the proposed model for the new vibratory control loop and then compares the new approach with a traditional method by measuring time delay in control input. The study also demonstrates that AR enhances time efficiency and accuracy in controlling robotic arm positions, matching actuator frequencies, and deploying sensors with minimal time delay.

Classification of Temperature and Humidity in Green Open Spaces by Implementing Internet of Things (IoT) using Mamdani Fuzzy Logic

The condition of green open spaces plays a pivotal role in influencing the comfort and well-being of users engaged in various activities within these environments. Hydrological and microclimate factors, particularly temperature and humidity, hold significant sway over the ecological balance in these areas. This study addresses the need for a tool to assess air temperature and humidity, facilitating public access to critical environmental data that impacts the psychological well-being of living organisms. In pursuit of this objective, a comprehensive monitoring system harnessing the power of the IoT was developed. This system integrates DHT22 and MQ-9 sensors to monitor temperature, humidity, and CO2 gas levels within multiple green open spaces. Data from these sensors is transmitted to a central database with minimal time delays: 2 seconds from the sensors to the server, 1 second from the server to the application, and 3 seconds from the hardware to the application. Impressively, this data transmission achieved a 100% success rate. To assess the comfort levels of these green open spaces, the system employs fuzzy Mamdani logic. It processes data obtained from the DHT22 sensor, using predefined temperature and humidity value thresholds. This innovative monitoring system provides valuable insights into the environmental conditions of green open spaces, contributing to the enhancement of the overall quality and suitability of these areas for various activities.

Ultrasparse Ultrasonic Synthetic Aperture Focus Imaging by Passive Sensing.

Ultrasonic synthetic aperture focus techniques (SAFTs) using less than the total number of available array elements to transmit ("sparse" transmissions) have been recently used in both medical imaging and industrial nondestructive testing (NDT) imaging to increase test speed and simplify multiplexer hardware. The challenge of sparse arrays is to obtain a reasonable image quality given the reduced transmitter-receiver combinations available to the beamforming process. This article proposes a "ultrasparse" SAFT method that employs a minimum number of transmitter elements (from one to four elements only) to obtain an entire full-matrix capture (FMC) set of waveforms. Specifically, a "virtual" FMC is obtained from normalized cross-power spectra between each array element pair in an implementation of "passive" ultrasonic sensing. In order to maintain high image quality without sacrificing imaging speed (e.g., applying a minimal initial time delay and keeping a short time recording window), several key steps have to be taken in this "passive" imaging mode, specifically: 1) the use of carefully designed segment-averaged normalized cross-power spectrum (NCPS) for robust passive reconstruction of the ultrasonic impulse response function (IRF) between two receivers; 2) the use of both the causal and acausal portions of the passively reconstructed IRFs; and 3) the compounding of multiple wave modes in the beamforming process. These steps also ensure the elimination of the near-field blind zone hence potentially enabling near-field imaging. The article first reviews the theory of passive IRF reconstruction between two receivers, comparing time-averaged cross correlation versus segment-averaged NCPS, and then demonstrates the application to ultrasparse SAFT FMC imaging of drilled holes in an aluminum block using a linear transducer array where only one to four elements are used in transmission.

Improved post-radiation behavior of FinFET based CMOS with workfunction modulated gate

The total ionizing dose (TID) effect of modulated gate workfunction (MGW) FinFET based CMOS inverter is designed and analyzed. The post radiation analysis of the voltage transfer characteristics, noise margin and propagation delay are demonstrated. The incorporation workfunction modulation engineering enhances the OFF-state performance, and maintains positive threshold voltage for both the pre and post radiation condition. 2-decade improvement is noticed for the both n-FinFET and p-FinFET. In addition, the proposed technique offers minimum propagation delay time and acceptable noise margin range even after 2000 krad of radiation dose. The analysis and comparison of the results is done by the 3-D TCAD simulator.

Strong Climate Control on the Millennial‐Scale Dust Variability and Sediment Provenances in the Equatorial Indian Ocean Inferred From Sr‐Nd Isotopes

AbstractHigh‐resolution Sr and Nd isotope compositions along with major and trace element abundances have been analyzed in silicate fraction of sediments core, SSD004‐GC03, from the Equatorial Indian Ocean (7.2°N and 77.9°E) at 1,540 m water depth with a depositional history of ∼38 ka to determine source variabilities and their controlling factors. 87Sr/86Sr (0.71978–0.72491), ƐNd (−14.8 to −21.9), and a couple of source diagnostic elements display profound variability over the depositional time scale and point toward major sediment contribution from the Peninsular Gneissic Complex (PGC) and the Deccan Basalts along with aeolian dust flux, their relative proportions being determined by climate variability. The cold/arid periods are characterized by an enhanced proportion of aeolian dust and the Deccan Basalts, whereas the sediment contribution from the PGC is augmented during the warm/humid periods. The sediment provenance variations at the Equatorial Indian Ocean coincide very well with known cold/arid (Heinrich Stadial events: HS 1–4, LGM, Younger Dryas, 8.2 ka, 5.2 ka, and 1.1 ka) and warm/humid (Early Deglacial, Holocene Intensified Monsoon) climatic events reported in the tropical region and sea‐level change which are strongly captured by the Sr‐Nd isotope and elemental composition of sediments. The present investigation underscores the significant role of climate, mainly the aridity, in modulating the dust fluxes and erosion intensity and the strong coupling between Indian monsoon and North Atlantic climatic oscillations and further demonstrates minimal time delay between the production and transport of sediment from source to sink.

Accelerating the Assessment of Hysteresis in Perovskite Solar Cells.

Halide perovskite materials have reached important milestones in the photovoltaic field, positioning them as realistic alternatives to conventional solar cells. However, unavoidable kinetic phenomena have represented a major concern for reliable steady-state performance assessment from standard current-voltage measurements. In particular, the dynamic hysteresis of current-voltage curves requires relatively long stabilization to achieve a credible figure for the power conversion efficiency. Hysteresis is caused by complex current transient phenomena that become active during staircase voltammetry. Here, we address the root of this problem. We pinpoint the dynamic characteristics behind the slow transient responses to strategically predict a minimum time delay and thus estimate the power conversion efficiency under steady-state conditions. Circuit-element analysis and impedance spectroscopy confirm our predictions based on an advanced transient study. Our results fundamentally explore the possibility of reducing data time acquisition in a reliable performance assessment, providing disruptive solutions and perspectives toward systematic production of photovoltaic perovskites.

Constructing independent CNTs conductive network to boost combustion performance of metastable intermixed composites

AbstractNovel metastable intermixed composites (MICs) constructed by carbon nanomaterials are expected to achieve high energy content and high combustion efficiency, but traditional preparation technologies always bring barely improvement in performance. Herein, novel PVDF/CuO/Al@CNTs MICs with independent continuous carbon nanotubes (CNTs) conductive networks were prepared by thoroughly utilizing the conductivity and photothermal properties of CNTs. A conductive network can be constructed at the interface of each encapsulated PVDF/CuO/Al particle with the addition of &gt;0.5 wt% CNTs. The great increase in electrical and thermal conductivity of PVDF/CuO/Al@CNTs MICs indicates excellent energy transfer efficiency across the sample. Significant enhancement of the combustion reaction has been achieved, with the minimum ignition energy and ignition delay time of PVDF/CuO/Al@CNTs3 reduced by ~31% and ~50%, respectively. This indicates that the CNTs with unique photothermal properties can be utilized as an effective igniter. Moreover, the optimal PVDF/CuO/Al@CNTs1 MICs enhanced the pressurization rate (~300%), energy output (~55%), and combustion velocity (~200%). The mechanism of the fast combustion reaction can also be discussed by the weak interface interaction and the energy conductive of the CNTs network throughout the sample. This work provides a modern strategy for strong combustion MICs that can be generalized and applied in the field of energetic materials.Highlights An independent continuous CNTs conductive network was prepared with a small amount of CNTs. The electrical and heat conversion efficiency is greatly improved. CNTs with unique photothermal properties can be utilized as an effective igniter. The laser sensitivity is improved, and the reaction energy, pressure, and pressure rates are significantly increased. The combustion performance was significantly improved, and more intense, and the combustion speed was significantly increased.

Importance of the Frequency at Using Immunomodulatory Therapies with Evidence Based and Standardized Plant Biomodulators

Many years ago, a great deal of research was carried out to improve the suppressed activity of innate immune system in cancer patients using various immunomodulators originated from microorganisms or plants. However, more than 30 years ago these investigations were stopped since their repeated applications often led to a tolerance which could not be explained at the level of science at that time and in spite of a great amount of data, the curative role of innate system was poorly understood. Today, growing evidence suggests that the adaptive cytotoxic T cells have rather prophylactic effects working more proficiently in the early phases of tumor development, whereas the innate cellular system acts more curatively in parallel with disease progression. It’s now also known, that tumor-induced dysregulation of the innate immune system leads to a decreased function of type-1 effector cells and a predominance of type-2 cells, promoting the development of tumors. In this review article a number of results originating from old publications are discussed and presented again in order to interpret them according to our current knowledges which appear to be helpful for more correct application of standardized and evidence based immunomodulators (SEIM) from plant or microbes. Conclusions: 1.) Since the chemistry is not able to produce appropriate structures of Pathogen Associated Molecular Pattern (PAMP) molecules, we need PAMP containing SEIM from plants and microbes which can activate the type-1 phagocytic cells by binding their Pattern Recognition / Toll Like Receptors (RCC/TLR) on their cell membrane. 2.) PAMP molecules have a direct effect only on RCC/TLR molecules of phagocytes and only thereafter with a minimum time delay of 24 hours are the regulatory cascade mechanisms activated which can increase the function of the for the curative tumor defense important MHC-I unrestricted effectors (such as NK, γδT and type-1 NKT cells). 3.) A permanent activation of phagocytic cells can result in a decrease in MHC-1 unrestricted immune function, which may explain the tolerance observed often during continuous SEIM treatments. 4.) Since short-term activations of type-1 phagocytic cells causes more antitumor benefit, on the base of kinetic investigations a necessity to insert of 72h therapy-free intervals during SEIM therapy must be taken into consideration.

LIGO–Virgo–KAGRA's Oldest Black Holes: Probing Star Formation at Cosmic Noon With GWTC-3

In their third observing run, the LIGO–Virgo–KAGRA gravitational-wave (GW) observatory was sensitive to binary black hole (BBH) mergers out to redshifts z merge ≈ 1. Because GWs are inefficient at shrinking the binary orbit, some of these BBH systems likely experienced long delay times τ between the formation of their progenitor stars at z form and their GW merger at z merge. In fact, the distribution of delay times predicted by isolated binary evolution resembles a power law with slope −1 ≲ α τ ≲ −0.35 and a minimum delay time of . We use these predicted delay time distributions to infer the formation redshifts of the ∼70 BBH events reported in the third GW transient catalog GWTC-3 and the formation rate of BBH progenitors. For our default α τ = –1 delay time distribution, we find that GWTC-3 contains at least one system (with 90% credibility) that formed earlier than z form > 4.4. Comparing our inferred BBH progenitor formation rate to the star formation rate, we find that at z form = 4, the number of BBH progenitor systems formed per stellar mass was and this yield dropped to by z form = 0. We discuss implications of this measurement for the cosmic metallicity evolution, finding that for typical assumptions about the metallicity dependence of the BBH yield, the average metallicity at z form = 4 was , although the inferred metallicity can vary by a factor of ≈3 for different assumptions about the BBH yield. Our results highlight the promise of current GW observatories to probe high-redshift star formation.

Construction of a simulated dynamic model of data packet routing on a telecommunication network fragment

The object of the current research is the process of routing data packets in a telecommunications network. It was established that the state and parameters of data transmission channels and routers could have a negative impact and need to be taken into account in the process of modeling the routing of data packets in telecommunication networks. A model of simulated dynamic modeling of data packet routing in telecommunication networks has been devised and proposed. The suggested model makes it possible to establish quantitative values of the delay time of processing data packets during their routing along a separate segment of the telecommunications network, taking into account the state and parameters of the data transmission channel and routers. It has been established that the achievement of the minimum delay time of data packets during routing is achieved by choosing the path of their transmission under the condition of minimum transmission time by communication lines and the capabilities of routers in terms of their accumulation and service speed. At the same time, the reduction of packet transmission delay time relative to the average for the time network segment can reach from 21 to 38 percent. It is shown that the main factor affecting the value of the delay time is the speed of data processing along the selected path of packet transmission. The number of routing nodes in a separate data transmission path can affect the delay time only if the parameters of the routers are equal compared to others that are included in alternative routes. The model of simulated dynamic modeling of data packet routing reported in this work, unlike the existing ones, takes into account the state and parameters of data transmission channels and routers. It can be used in practical improvement of existing and development of new multi-service telecommunication communication networks

The enhancement of heterobimetallic MOFs on the pyrolysis and laser ignition of FOX-7

The hydrothermal approach had been used to synthesize two new heterobimetallic Metal Organic Frameworks (MOFs), Ba4Pb4(CH3CO2)8[(CH6CO2)4Pb](CH3CO2)4 (PbBa-MOF) and Ba2Ni(CO2H)6(OH2)4 (NiBa-MOF), their structure and surface topography were then examined with XRD and SEM. By using the TG-DSC and TG-FTIR-MS methods, the pyrolytic decomposition properties of MOFs and their catalytic activities on the 1,1-diamino-2,2-dintroethene (FOX-7) pyrolysis were investigated. The PbBa-MOF has a single thermal decomposition process with a high thermal decomposition temperature, while NiBa-MOF has a three-stage thermal decomposition process initiated from a lower temperature. Furthermore, the thermolysis peak temperature of the FOX-7/PbBa-MOF and FOX-7/NiBa-MOF mixture has a great decrease by 24.2 °C and 27.4 °C compared with the FOX-7. However, the low pyrolysis peak temperature and the pyrolysis activation energy (Ea) are almost unchanged. The selective high temperature catalytic effect of the MOFs on FOX-7 results from the activation of -NH2 in the high temperature pyrolytic decomposition of FOX-7 by the metallic ions of the MOFs. This thermal catalytic property indicates that MOFs can promote the pyrolytic decomposition of FOX-7 while ensuring the safety requirements for the compatibility of energetic mixtures in the preparation of propellants. The relationship between the features of pyrolytic decomposition and laser ignition was finally covered and defined. The two MOFs decreased the minimum ignition energy and ignition delay time of the FOX-7. Novel MOFs combustion catalyst may strengthen ignition and combustion features of the high-energy and low-sensitivity solid propellants containing FOX-7.

Dissipativity for Discrete-Time Switched Positive Delay Systems: A Dwell-Time-Dependent Linear Copositive Storage Functional Method

This article addresses the problems of dissipativity analysis and feedback dissipativity of discrete-time switched positive systems with time-varying delay. On the basis of the positivity property of the investigated system, the definition of linear <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$(q,r)$</tex-math> </inline-formula> - <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$\alpha$</tex-math> </inline-formula> -dissipativity, utilizing the linear copositive storage functionals with linear supply rates, is first introduced. The switching among subsystems is orchestrated by a state-dependent switching policy that obeys prespecified dwell-time constraints. Second, in order to reduce the conservatism brought by the identical summation term functional for all positive subsystems, we propose a dwell-time-dependent linear copositive storage functionals involving summation terms which are diverse appearing in the functional. Then, less conservative criteria are developed to guarantee the system is strict <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$(q,r)$</tex-math> </inline-formula> - <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$\alpha$</tex-math> </inline-formula> -dissipativity by resorting to the switching policy or the joint implementation of the switching policy and time-varying controllers for subsystems. Finally, the validity of the proposed techniques is illustrated through two examples, and the relationship among the minimum dwell time, performance index, and time-varying delay is also revealed.

Delay sampling theorem: A criterion for the recovery of multitone signal

Periodic nonuniform sampling (PNS) is widely used in sub-Nyquist sampling schemes of multitone signals. However, what sampling pattern of PNS enables the signal to recover from the sub-Nyquist samples? Although this problem has been discussed in different schemes, the corresponding answers vary greatly. In this paper, we introduce the recurrent delay times to describe a PNS and provide a mathematical definition of signal recoverability from the perspective of delay. On this basis, we review the well-known Shannon–Nyquist sampling theorem and suggest a delay sampling theorem (DST) that a multitone signal bandlimited to [0,fmax] can be perfectly reconstructed from its periodic nonuniform samples when its minimum combined delay time τmin is not more than the Nyquist interval 1/2fmax. To explain and demonstrate the DST, subspace theory-based algorithms and active aliasing and de-aliasing algorithm (AADA) are proposed and used to recover the spectrum or waveform of multitone signals. The high consistency between practical and theoretical results evidently verifies the correctness of DST. In terms of sampling and recovery of multitone signal, DST extends the Shannon–Nyquist sampling theorem and naturally unifies several existing sampling strategies from the perspective of delay. DST provides a new guideline for the sub-Nyquist sampling of multitone signals. According to the DST criterion, we can optimize the sampling patterns to reduce cosets and improve the supremum frequency such that the reconstructed spectrum is alias-free. By generalizing the sampling theorem from the view of delay, DST opens many avenues for the development of multitone signal processing.

A Method and an Algorithm for Implementing Relay Protection of 6(20)/0.4 kV Step-down Transformer Substations

The article discusses a method and an algorithm for implementing the protection system for a 6(20)/0.4 kV transformer substation, using which its reliable operation is secured regardless of the grid configuration and operation mode and the operation parameters of higher-level electrical installations. The proposed method makes it possible to clear any fault in the 0.4 kV network with minimal time delays. To this end, it is necessary to supplement the 0.4 kV network with current transformers (if they are not available) and forward the algorithm control output to the circuit breaker tripping coils. To ensure short-range backup protection, the circuit breakers protective functions remain in operation. Based on the existing electrical network, the approximate pickup parameters of the proposed method are pointed out, and recommendations for their optimization are given. Various contingencies in the 0.4 kV electrical network are considered to verify the correct functioning of the proposed relay protection method and algorithm.

Women take longuer to seek help when suffering a STEMI

Abstract Funding Acknowledgements Type of funding sources: None. Introduction Historically, the prognosis of those women suffering a STelevation myocardial infarction (STEMI), has been worse compared to men. Some causal factors are presentation at later ages, atypical symptoms, lower perception of risk and less sensitivity of the health care providers. Purpose Our hypothesis is that there are still differences in the presentation of STEMI based on gender, which could be identified to guide new public campaigns in this perspective. Therefore our primary outcome is to find gender differences in symptoms and time delays in a cohort of STEMI patients, and secondary outcomes are differences in mortality and bleeding. Methods We conducted a retrospective analysis carried out in the Acute Cardiac Care Unit (ACCU) of a tertiary care hospital, where 50% of the medical staff are women. Patients hospitalized for STEMI for one year were included and a detailed caracterization of symptoms, time delays, and adverse events was recorded. Finally, the patients were classified according to gender, and differences in primary and secondary outcomes between both groups were analyzed. Results Between May/2020 and May/2021, 1056 patients were admitted to the ACCU, 33% were women. A total of 115 STEMI patients were included for the analysis, 21% were women. Basal characteristics of both groups were equivalent, except for a non significand trens towards less prevalence of peripheral arterial disease in women (0% vs. 11%; OR 0.890, IC 95% 0.828-0.957; p=0.089). Opressive chest pain was the most frequent symptom, but it was less frequent in women (75% vs. 91.4%, OR 0.284, IC 95% 0.085-0.948; p=0.033), whereas they presented more frequently with stabbing pain (13% vs. 2.4%, OR 6, IC 95% 1.073-38.35; p=0.035), and their pain was more frequently radiated towards the neck (28.6% vs. 4.9%, OR 7.7, IC 95% 1.1936-30.631; p=0.001), and associated to nausea/vomiting (45% vs. 1.3%, OR 5.809, IC 95% 1.930-17.486; p=0.001). There was a non-significant trend towards a longer time delay between pain onset and seek for help in women (185min IQR 747 vs. 60min IQR 454, p=0.098), being the other system time delays equivalent between both gender groups. Women had an increased bleeding risk, with a higher CRUSADE score (47.48 ± 22.92 vs. 28.60 ± 16.72, p=0.001) and higher incidence of bleeding events (12.55% vs. 0%, OR 11.68, IC 95% 9.82-13.29, p=0.001). There were no differences in the treatments administered or in mortality (12.5% vs. 14.3%, p=0.822). Conclusions Women suffering a STEMI more often reported stabbing chest pain, radiating to the neck, and associated to nausea/vomiting compared with men, and took longer to seek for help. These findings could help in the design of future campaigns to minimize time delays, targeting these different symptoms in female population.