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A 650-V/84-m normally-off GaN/SiC cascode device is demonstrated with systematic static and dynamic characterizations. The cascode device features a low voltage enhancement-mode (E-mode) GaN-HEMT to enable normally-off gate control, and a 650 V normally-on SiC JFET provides the high-voltage blocking capability. The GaN/SiC cascode device exhibits many application-desired behaviors, including reverse conduction capability, avalanche breakdown capability, thermally stable threshold voltage, low input/output capacitances, no dynamic RON degradation, and negligible dynamic VTH shift. In addition, a customized double-pulse test board is built to evaluate the switching performance of this cascode device and other 650-V SiC-based power devices. This cascode device adopting low-voltage GaN HEMT has low QGRON and exhibits excellent switching performance. The switching losses (EON and EOFF) are much smaller than that of 650-V Si/SiC cascode device and comparable to that of the state-of-the-art 650-V SiC MOSFETs.

In order to address the issue of wireless communication signal blocking in the traditional cavity resonance wireless power transfer (CR WPT), a wall-meshed cavity resonator constructed of the meshed metallic walls is proposed together with an analytical design method. This cavity resonator can not only generate and confine the electromagnetic waves of natural resonant modes inside the cavity resonator, but also support wireless communications with outside. The wall-meshed cavity resonator is analytically designed by the known theoretical equations without time-consuming optimizations and verified by electromagnetic simulations and experiments. The results show that the proposed CR WPT system can achieve simultaneous wireless power transfer in the cavity and wireless communications with outside. The maximum power transfer efficiency is higher than 85%. The power transfer efficiency exceeds 60% within about 70% areas inside the wall-meshed cavity. For wireless communication signals passing through the wall-meshed cavity, the attenuation at 2.1 GHz (4G), 2.45 GHz (Wi-Fi), and 3.5 GHz (5G) is about 6.0 dB, 5.1 dB, and 3.8 dB, respectively. Additionally, the safety performance of the proposed CR WPT system is numerically investigated by the specific absorption rate analysis of a human torso model.

The full-bridge submodules (FB-SMs) in hybrid modular multilevel converters need to absorb the enormous energy stored in dc side and arm inductors during dc fault blocking, which may lead to severe overvoltage. An energy absorbing branch (EAB) composed of metal oxide varistor (MOV) and thyristors is proposed in this letter. No extra power loss is produced by the EAB during normal operation. The EAB can absorb a part of the energy and reduce the energy absorbed by FB-SMs suffering from severe overvoltage by clamping the dc voltage. Thus, the maximum FB-SM overvoltage is reduced. Turning off the EAB several milliseconds after the blocking of the converter can accelerate the decaying of the dc fault in the transmission line and reduce the required energy volume of MOV with minimal effect on the maximum FB-SM overvoltage. The proposed EAB shows better technical and economic performance than existing methods. The proposed EAB is validated by simulations and experiments.

A displaced surgical neck fracture can be a good indication for antegrade intramedullary nailing. However, nail insertion may result in malreduction and translational displacement of the humeral head fragment because of muscle traction and size discrepancies between the diameters of the medullary canal and the intramedullary nail. We used blocking screw augmentation in 20 fractures with residual medial displacement of the distal fragment after nail insertion to anatomically reduce displacement of the fracture and to maintain the reduced position before bone union. A blocking screw was placed percutaneously at the lateral side of the canal. Next, a straight intramedullary nail was reinserted medial to the blocking screw. Finally, the nail was locked both proximally and distally. All cases showed bone union without fixation failure at the time of the final follow-up. Blocking screw augmentation with intramedullary nailing is feasible for the treatment of humeral surgical neck fractures and is thought to be helpful for fracture reduction during surgery and stable fixation after surgery.

The insulated gate bipolar transistor (IGBT) can be configured to provide forward and reverse blocking voltage capability using the symmetric structure or only forward blocking voltage capability using the asymmetric structure. The control of current flow through the IGBT can be obtained by using either a planar D-MOS gate structure or a trench U-MOS gate structure. The collector region doping profile can be adjusted to reduce the injected carrier density with the transparent emitter concept. Complementary n-channel and p-channel IGBT structures are useful for AC power control. Lateral IGBTs are of interest for integration with control circuits. Novel IGBT structures that allow enhanced performance are described.

Degradation caused by humidity affects the blocking characteristic of an insulated gate bipolar transistor (IGBT) module, leading to an increased leakage current and/or a reduced voltage blocking capability. The proposed measurement system enables the in situ detection of decreased breakdown voltage and increased leakage current. Thus, it can assess the degradation level of power modules when installed in a converter. This test is intended primarily for wind power converters and can be part of the start-up procedure of the system. The working principle has been validated on predamaged power modules arranged in half-bridge configuration, using a demonstrator implementation of the proposed approach in laboratory experiments. Due to the simplicity of the circuit, this concept is easy to integrate in existing inverter systems at a comparatively low cost.

The trade-off relationship between specific on-resistance and short-circuit withstand time in 1.2 kV 4H-SiC MOSFETs was drastically increased using a novel device structure. MOSFETs with deep P-well formed using channeling implantation were firstly demonstrated to improve short-circuit ruggedness (~4 times longer than conventional MOSFET) with no negative impact on specific on-resistance. Proposed MOSFETs achieved short-circuit withstand time of 8 μs. Channeling implant with low energy was conducted to form deep P-well junctions. Fabrication of a deep P-well using channeling implantation is demonstrated using no additional nor complicated processes when compared to the conventional MOSFET fabrication process. A comparison between the conventional and novel designs was performed in terms of the output characteristics, blocking behaviors, and short-circuit ruggedness.

Distributed Denial-Of-Service (DDoS) attacks are one of the all the more difficult security issues on the Internet today. They can without much of a stretch, fumes the assets of the potential Victims. The issue is much more extreme since the aggressors regularly produce their IP delivers to shroud their character. The current guard mechanism against DDoS attacks, the attack traffic will be filtered at the victim’s side. For this situa- tion, regardless of whether the attacking traffic is filtered by the victim, the attacker may achieve the objective of blocking access to the victim’s bandwidth. IP-Trace back ap- proaches enable the victim to trace back to the wellspring of an attack and they will not be able to minimize the attack when the attack is in progress. Hence is to minimize the quan- tity of malicious packets entering into the network we put forth a quantum annealing technique to identify and alleviate the DDoS attack. The attack messages are minimized by utilizing client puzzle as a part of the ingress router; the path fingerprint is used at the egress side. Simulation studies prove that the proposed mechanism is optimally successful in recognizing and mitigating the DDoS attacks.

Study Design This is a basic science research. Introduction Isolating excursion of the flexor digitorum profundus (FDP) in zones I and II is common practice in the current management after flexor tendon repair. During this procedure, the proximal interphalangeal joint is sometimes fully extended with unmeasured external forces at the middle phalanx when the distal interphalangeal joint is actively flexed. Purpose of the Study The purpose of the study was to investigate the incremental effect of external force with palmar blocking versus lateral blocking and increased angles of flexion on internal tendon forces at the repair site for a safer application of force by the treating therapist. Methods Eight human cadaveric fingers were studied. To simulate palmar or lateral finger blocking, a compression force of blocking was applied from 5N (510 grams) to 25N (2,550 grams) on the skin surface of the palmar or the lateral aspect of each of these middle phalanges in 5N increments. The tensile load on the FDP tendon during distal interphalangeal joint flexion from 0° to 60° was measured in 10° increments. Results During palmar blocking, the tensile load was significantly increased with increases in palmar blocking force. However, no significant increase in the tensile load on the FDP tendon was observed at any lateral blocking. Discussion Lateral blocking exercise can be performed with less tensile force on the FDP tendon when performing blocking exercise after flexor tendon injury repair. Conclusions This study supports the concept that lateral blocking with incremental joint angles allows a safer application of force for the healing tendon.

Psoriasis is one of the most common autoimmune dermatoses with a chronic relapsing course. Biologic therapy should be initiated for patients with moderate to severe psoriasis when conventional systemic therapy and phototherapy are ineffective, or their use is limited due to comorbidities. In Latvia, adalimumab is the first choice of biologic drugs for treatment of psoriasis. The correlation between changes in cellular and humoral immunological parameters and clinical signs based on immunological data from psoriasis patients are evaluated in the publication.

The optical analysis of Linear Fresnel Reflectors solar concentrators deals with the calculation of the absorbed flux at the receiver. Due to concentrator discrete and complex geometry ray tracing numerical simulations is the main used method, in parallel with some analytical approaches that have been developed for specific cases. This paper presents an analytical method for Linear Fresnel Reflectors with a flat receiver. It is based on Zhu’s vector-based method and Rabl’s concepts of acceptance and effective source, although new shading (including receiver shading), blocking, and cosine losses analyzes are presented, with the inclusion of end-losses effect. As shown, the problem is better described by the concept of intercept factor, the effective aperture area used to collect the incident sunlight. Comparison tests with ray tracing simulations performed in SolTrace for three different effective sources were carried out to validate the analytical model for both factorized and biaxial models of the intercept factor, including energetic evaluations for Evora, Portugal. In general, analytical results do agree very well with ray tracing, better for the factorized model than the biaxial. Errors in the analytical estimative of intercept factor can be high up to 132% for the biaxial model at high longitudinal incidence angles; on the other hand, errors in the amount of annual absorbed energy were high up to only 3%.

BACKGROUND Fractures of both proximal and distal metaphyses with small distal fragment of tibia are not uncommon. Internal fixation using intramedullary nails alone could lead to misalignment. Using blocking screws (Poller screws) in addition to intramedullary nails would help in narrowing the medullary cavity and decreases the degree of misalignment and chances of displacement. The present study was conducted to evaluate functional and radiological outcome of blocking screws with intramedullary nail in the treatment of proximal and distal metaphyses fractures of tibia with short distal fragment. METHODS A prospective observational study of 34 patients with proximal and distal tibial metaphyses fractures was treated with statically locked intramedullary nailing with supplementary blocking screws. The study was conducted from January 2018 to December 2020 with a maximum follow up of 18 months. Medullary canal diameter was measured at the levels of fracture and isthmus. RESULTS Among the 34 patients, 29 (85.29 %) were males and 05 (14.70 %) were females with a male to female ratio of 5.8 : 1. The mean age was 34.97 ± 3.10 years. The mean healing period was 20 ± 1.45 weeks. 25/34 (73.52 %) of the patients showed Karlstrom and Olerud functional grading score of excellent. The fracture varus/valgus alignment was 1.9 ± 0.3 degrees. The mean antecurvatum/recurvatum alignment was 0.3 degrees. CONCLUSIONS Blocking screws act as reduction tools, help in reducing the medullary lumen of distal metaphyses and prevent failures in initial reduction. They extend the indication of intramedullary nailing to the distal segment of tibia and minimize the misalignment in terms of varus /valgus and/or antecurvatum/recurvatum. KEYWORDS Tibia, Intramedullary, Blocking Screws, Internal Fixation and Misalignment

Cognitive radio is an emerging technology, aimed at efficient use of the scarce radio spectrum. In cognitive radio networks (CRNs), spectrum licensed to the primary users (PUs) is shared by the secondary users (SUs) which affects the performance of the network. This paper proposes a novel spectrum management scheme for CRNs, where heterogeneous secondary real-time and non-real time users compete for the available channels with primary users and utilize two types of buffers under the probability retrial policy. To enhance the quality of service (QoS) for the secondary users (SUs), spectrum handoff and call buffering strategies with retrial policy are employed jointly so that SUs that would otherwise be blocked or forcibly dropped could be queued and possibly served later. The whole system is modeled using a multi-dimensional continuous-time Markov chain (CTMC) and accordingly, the QoS performance metrics are derived. Numerical results are presented which illustrate that the provision of queues under the proposed retrial policy increases overall network resource utilization and throughput while decreasing blocking and dropping probabilities.

A monolithic bidirectional switch based on anti-paralleled two reverse blocking p-GaN HEMTs has been proposed and demonstrated in this work. The recessed Schottky drain technique is utilized to effectively reduce the on-state voltage and thus lowering the power loss of bidirectional switches. A significant reduction in parasitic elements and switch area is obtained by monolithic integration. The fabricated bidirectional switch exhibits a threshold voltage of ~1.85 V, on-state voltage of ~0.63 V, and the forward and reverse off-state breakdown voltages of ~650 V at ${I}_{{\text {S1}-\text {S2}}} = 1\,\,\mu \text{A}$ /mm. In addition, the function of proposed bidirectional switch as an AC power chopper has been successfully verified.

We consider a situation, when braking is the only way to avoid obstruction of an automotive vehicle or a railroad train with a suddenly detected steadfast obstacle blocking the path. The velocity a...

Blocking the tunnel portal is one strategy in railway tunnel firefighting. In order to evaluate the effect of tunnel portal sealing ratio on fire behaviour, Fire Dynamics Simulator (FDS) was used to simulate tilted tunnel fire with different slope angles varying from 0% to 5%, heat release rate varying from 10 to 50 MW and sealing ratios varying from 0% to 75%. Results show that the experimental data of the temperature distribution inside the tilted tunnel were in good agreement with the simulation results. Moreover, the ceiling temperature rise decreases along the tunnel with the increase of the tunnel portal sealing ratio at initial stage and then tends to stabilize because of less oxygen supply when the heat release rate is relatively large. The maximum temperature rise decays exponentially along the tunnel ceiling with distance. The current model for temperature decay beneath the tunnel ceiling was proposed to be modified by taking the tunnel entrance sealing ratio into account. The predictions by the modified model agree well with the experimental measurement. The results could provide practical information and knowledge in ventilation system design and emergency evacuation for inclined railway tunnels.

Entity matching (EM) finds data instances that refer to the same real-world entity. Most EM solutions perform blocking then matching. Many works have applied deep learning (DL) to matching, but far fewer works have applied DL to blocking. These blocking works are also limited in that they consider only a simple form of DL and some of them require labeled training data. In this paper, we develop the DeepBlocker framework that significantly advances the state of the art in applying DL to blocking for EM. We first define a large space of DL solutions for blocking, which contains solutions of varying complexity and subsumes most previous works. Next, we develop eight representative solutions in this space. These solutions do not require labeled training data and exploit recent advances in DL (e.g., sequence modeling, transformer, self supervision). We empirically determine which solutions perform best on what kind of datasets (structured, textual, or dirty). We show that the best solutions (among the above eight) outperform the best existing DL solution and the best existing non-DL solutions (including a state-of-the-art industrial non-DL solution), on dirty and textual data, and are comparable on structured data. Finally, we show that the combination of the best DL and non-DL solutions can perform even better, suggesting a new venue for research.

Recent developments in position sensitive detectors pave a way towards the efficient realization of Rutherford Backscattering Spectrometry/Channeling experiments in blocking geometry. Here we report on the use of a Timepix position sensitive detector (PSD) for this kind of studies. The blocking geometry in combination with a PSD brings the advantage that it is straightforward to measure full two-dimensional blocking patterns, which reveal considerably more details than one-dimensional angular scans. The Timepix detector response was first calibrated using internal test-pulses, followed by determining the energy resolution for ~5.5 MeV α particles from radioactive sources, and for 1.8 MeV alphas from a 2 MeV 4He+ beam backscattered from a Au target. An effective count-rate of ≈2000 events/s and energy resolution of ≈47 keV at 1.8 MeV were achieved. Blocking effects from backscattered α particles were measured around the 〈1 0 0〉 axis of Si and the 〈0001〉 axis of 6H-SiC single crystals and compared to theoretical patterns calculated by means of FLUX Monte Carlo simulations, from which the angular resolution achieved with the setup could be determined to be 0.10°-0.12°.

A common aim of epidemiological research is to estimate the causal effect of a particular exposure on a particular outcome. Towards this end, observed associations are often ‘adjusted’ for potential confounding variables. When the potential confounders are unmeasured, explicit adjustment becomes unfeasible. It has been demonstrated that causal effects can be estimated even in the presence of umeasured confounding, utilizing a method called ‘front-door blocking’. In this paper we generalize this method to longitudinal studies. We demonstrate that the method of front-door blocking poses a number of challenging statistical problems, analogous to the famous problems associ- ated with the method of ‘back-door blocking’.

In indirect-drive inertial confinement fusion, thin films on laser entrance hole (LEH) windows are needed to reflect thermal infrared radiation (IR) and to protect the deuterium-tritium (D-T) cryog...

This article examines Canada’s first internet gambling website blocking scheme, which was enacted in Quebec as part of the implementation of the province’s 2015 budget. Using qualitative research methods, the article illustrates the complexities of regulating online gambling. Influenced by critical sociological and anthropological studies of gambling, and taking a socio-legal, governmentality perspective, it shows how socio-legal studies can illuminate research on the regulation of gambling, and how the study of online gambling can, as a sentinel site for the regulation of online consumption, contribute to the development of socio-legal studies. Our analysis shows that the governmentality of online gambling is framed so as to exclude 1) a range of risks (e.g., related to consumer profiling and the capacity to stimulate “addictive consumption”), 2) the heterogeneity of everyday experience that connects online gambling with online addictive consumption more generally, and 3) a range of possibilities for governing online gambling otherwise.

Most meta-diaphyseal femoral fractures that are treated with intramedullary nailing can be reduced satisfactorily by skeletal traction without ‘opening’ the fracture site and therefore, complications such as nonunion, infection and wound healing problems are reduced. In cases where adequate fracture reduction cannot be achieved by skeletal traction, ‘reduction aids’ have been used during the operative procedure in order to avoid the exposure of the fracture site. The ‘blocking’ screw, as a reduction tool, was proposed initially for the ‘difficult’ metaphyseal fractures of the tibia. Subsequently, surgeons have tried to implement the ‘blocking’ screw technique in ‘difficult’ distal femoral fractures. This article presents the ‘blocking’ screw technique as an adjunctive process in the management of fractures of the proximal and distal femur which are found to be non-reducible by skeletal traction alone. The minimal invasiveness of the technique contributes greatly to the preservation of both the soft tissue integrity and the fracture haematoma and thus reduces the major complications that can occur by exposing the fracture site.Cite this article: EFORT Open Rev 2021;6:451-458. DOI: 10.1302/2058-5241.6.210024

Introduction Varenicline effectively helps smokers quit by reducing withdrawal symptoms and blocking the reward of smoking. However, most quitters return to smoking within one year. ‘Cue Restricted Smoking’ is a behavioral technique designed to increase quit rates by asking smokers attempting to quit to restrict smoking to the standing position, while alone, in an isolated area facing a wall, with the cigarette as the only stimulus. Methods Using retrospective clinic records we compared quit rates in 281 smokers (50% males) instructed in the cue restricted smoking cessation method during 2016–2018 to quit rates in 324 smokers (46% males) advised to completely stop smoking on the target quit date which we previously used during 2011–2014. All were prescribed varenicline for 12 weeks alone, with the addition of bupropion if needed after 4 weeks. Follow-up consisted of behavioral support at 4–6 visits during active drug treatment and telephone counselling at 24 and 52 weeks. The smoking cessation rate was confirmed with exhaled carbon monoxide at the clinic visit at 12 weeks and only by telephone at 52 weeks. Results The mean age of smokers was 49 years in both groups and the number of cigarettes smoked daily was similar (18/day in the cue restricted vs 19/day in the target quit day group). The smoking cessation rate at 12 weeks was 75% in the cue restricted versus 45% in the target quit day group (relative risk, RR=1.8; 95% CI: 1.4–2.2, p

Neuroactive substances released by activated microglia contribute to hyperexcitability of spinal dorsal horn neurons in many animal models of chronic pain. An important feedback loop mechanism is via release of fractalkine (CX3CL1) from primary afferent terminals and dorsal horn neurons and binding to CX3CR1 receptors on microglial cells. We studied the involvement of fractalkine signaling in latent and manifest spinal sensitization induced by two injections of nerve growth factor (NGF) into the lumbar multifidus muscle as a model for myofascial low back pain. Single dorsal horn neurons were recorded in vivo to study their receptive fields and spontaneous activity. Under intrathecal vehicle application, the two NGF injections led to an increased proportion of neurons responding to stimulation of deep tissues (41%), to receptive field expansion into the hindlimb (15%), and to resting activity (53%). Blocking fractalkine signaling by continuous intrathecal administration of neutralizing antibodies completely prevented these signs of spinal sensitization to a similar extent as in a previous study with the microglia inhibitor minocycline. Reversely, fractalkine itself induced similar sensitization in a dose-dependent manner (for 200 ng/mL: 45% deep tissue responses, 24% receptive field expansion, and 45% resting activity) as repeated nociceptive stimulation by intramuscular NGF injections. A subsequent single NGF injection did not have an additive effect. Our data suggest that neuron-to-microglia signaling via the CX3CL1-CX3CR1 pathway is critically involved in the initiation of nonspecific, myofascial low back pain through repetitive nociceptive stimuli.

In order to meet the ever-increasing traffic demands, the combination of fiber and Millimeter Wave (mmWave) is expected to play a key role for 5G Centralized-Radio Access Networks (C-RANs). Due to the inefficiency of the Common Public Radio Interface for the Baseband Unit (BBU)-Remote Radio Head (RRH) communication, analog-Radio-over-Fiber (a-RoF) technology is considered a promising solution, mainly due to the RRH simplification and lower fronthaul requirements it imposes. In such mmWave a-RoF C-RANs, efficient Medium Transparent-Medium Access Control (MT-MAC) protocols are needed able to meet the challenging 5G requirements. To this end, in this paper, we propose a gated service MT-MAC protocol which authorizes each user to transmit the amount of data it requested. A detailed delay model is proposed, which is validated through simulations for different fiber lengths, network load conditions and number of available optical wavelengths. Moreover, the proposed protocol is compared with the state-of-the-art (SoA) and is shown to achieve up to 20 times higher throughput, 2 times lower delay with 100% lower blocking probability and 5 times higher data wavelength utilization, while being able to adapt to varying network traffic conditions. Our proposal also attains sub-ms latency in most cases, constituting it a promising candidate for 5G mmWave a-RoF C-RANs.

Wearing blue-blocking lenses (BBLs) in the evening hours may not be effective in improving sleep quality. Optometrists need to be informed in prescribing BBLs by highlighting the consequences of their wear to the circadian system.Excessive exposure to artificial light, particularly at short wavelengths, during the evening, may disrupt normal nocturnal melatonin production, which is a natural process of the circadian rhythm and affect sleep quality. Current BBLs have been designed to limit blue-light exposure and may offer a means to minimise disruption to the circadian system. The purpose of this study was to evaluate the impact of BBLs on a normal sleep-wake circadian rhythm.Seven different commercial brands of BBLs (Crizal Prevencia, Smart Blue Filter, Blu-OLP, Blue Control, UV++Blue Control, SeeCoat Blue UV and Blue Guardian) and powers (+2.00 D, -2.00 D and Plano) were evaluated by quantifying the degree to which they reduce light radiation from lamps and electronic devices. In particular, the non-linear circadian index and the circadian stimulus was determined for various light sources to establish changes in melatonin production that occur while viewing through different BBLs.A large difference was shown in the effectiveness of different BBL brands in reducing the spectral sensitivity of the circadian system. The BBL brand was shown to selectively affect the non-linear circadian index and circadian stimulus, particularly with those with transmittance profiles that block the most blue light having the lowest effect on the suppression of nocturnal melatonin secretion.BBLs may not improve sleep quality, because they continue to allow the transmittance of blue light that may suppress nocturnal melatonin secretion and hence disrupt the normal sleep-wake circadian rhythm.

A primary purpose of the school library program is to enable young people to access and make effective use of information and ideas. This role has been enhanced through access to electronic resources. The Internet, however, is not a pre-selected menu of information sources deemed appropriate for children and young adults. Therefore, some libraries employ software to block or filter unfettered access to information. The purpose of this study was to measure the penetration of this filtering software in North America, to ascertain which types of software are used, and to determine librarians' levels of satisfaction.

This article discusses the importance and effectiveness of the use of targeted financial sanctions in the form of freezing, blocking criminal funds of persons involved in terrorist and extremism activity, organization of control in financial institutions in order to implement a system of counter actions of money laundering. As well as the problems of legislation in terms of compliance with the required and to ensure the procedures for freezing (blocking), seizure of assets obtained by criminal means.

From an energy-saving perspective, blocking infrared (IR) radiations in the solar spectrum has garnered increased attention, and several heat-shielding nanoparticle-based materials have been employ...

Dual-active-bridge (DAB) converter based on single-phase shift (SPS) modulation is commonly used in energy storage systems. However, if the normalized voltage gain deviates from unity, the zero-voltage-switching (ZVS) feature and efficiency of the DAB converter deteriorate. To overcome this challenge, this article proposes a hybrid-bridge and hybrid modulation-based DAB converter adapted to a wide voltage range. The primary-side hybrid bridge operates in an intermediate state between the full bridge and the half bridge. Asymmetrical pulsewidth modulation (APWM) is introduced to regulate the dc bias across the blocking capacitor in a continuous manner. Due to the synergy between the hybrid-bridge structure and hybrid modulation scheme, a general voltage match between the energy storage unit and the high-voltage bus is always achieved. Moreover, the ZVS range is extended and the circulating current is well suppressed. Therefore, efficiency is optimized over the wide voltage range. The operational principles, circuit modeling, and design considerations are detailed. A 500-W converter prototype, linking a 100–200-V energy storage unit and a 300-V dc bus, is designed and tested to validate the concept. A 97.9% peak efficiency and good overall efficiency over the wide voltage range are reported.

The two main goals in wireless networks are to provide channel allocation opportunities for incoming services and to assure the accomplishment of ongoing services. In this paper, a channel reservation scheme in cooperative cognitive radio networks (CRNs) based on dynamic spectrum access (DSA) is proposed. In this scheme, a centralized cognitive manager (CCM) provides the dynamic coordination access for primary users (PUs) and secondary users (SUs) through partitioning the spectrum into non-reserved channels (N-CRN) and reserved channels (R-CRN). N-CRN can be exploited by licensed PUs and unlicensed SUs, while R-CRN is dedicated for active SUs until the successful completion of their service. If a SU session in N-CRN is interrupted by the sudden arrival of PU, then a spectrum handover occurs to R-CRN to resume its session. The reserved channel number R is deduced upon the reduction of both forced termination and blocking probabilities for SUs while satisfying PUs’ traffic demands. Also, overall system cost and SU cost functions are investigated. Simulation results show significant reduction in blocking and forced termination probabilities and improvement in utility function and service completion rate of SUs while meeting PU’s quality of service (QoS) aims. For example, when the arrival traffic rates per channel λ p = 0.5 , and for R = 1 , R = 2 and R = 3 , the values of specific SU forced termination probabilities P ft are 0.1597, 0.116, 0.0799 respectively compared to 0.2106 for the case of no channel reservation. Furthermore, blocking probability and service completion rate of PU are evaluated to demonstrate the effect of channel reservation variation on the system performance.

The article is devoted to the study of countering international extremist activity features, including the intensifying corresponding Internet threats. The author notes that in modern conditions, threats of extremism require an integrated approach at the national and international levels, more effective mobilization of state and interstate forces and resources (financial, information, etc.), including acts of blocking relevant contacts and illegal virtual resources. The article contains statistical data showing an increase in extremist threats, including the youth environment, and, accordingly, the need to intensify and expand measures to counter such negative phenomena.

Background: Organic Light Emitting Diodes have emerged as a potential candidate for being used as the display because of their remarkable performance. In the past decade, a lot of interest was shown in their development and improvement. Scientists utilized different methods for enhancing their performance which included the change in OLEDs architecture. Different supporting layers (charge injection, transportation and blocking) are added in the architecture to enhance the performance of OLED. Some of the patents related to the application of the OLED have also been reviewed to observe the utilization of the present work in those applications. Objective: The motive of this research article is to analyze impacts the impact of different layers on the performance of OLED. Methods: The objective is achieved by systematically analyzing the impact of different layers on the OLED. The analysis commenced by investigating the properties of the basic OLED consisting of the emission layer only. Thereafter, in succession different supporting layers are added to the OLED architecture. Subsequently, after adding each layer, OLED device is analyzed and its properties are determined. Finally, the performance of different layers is compared. Results: The outcome of the above research study shows that these supporting layers are significantly able to enhance the performance of the OLED. Step by step layers are added to the architecture and enhancement in the performance is observed. There is an improvement of 13% to 38% not over the basic OLED architecture, but over the multilayered OLED device, which is already far better than the basic OLED. Conclusion: Therefore, from the analyses, it can be concluded that the different layers are significant for the OLED architecture and improve the performance of the OLED considerably.

Wireless sensor network technology has been widely studied and applied in different fields. The applications in shipborne wireless sensor networks face serious physical-layer packet loss problems due to the wireless signals blocking by steel structure and wireless channel interference. The MAC-layer retransmission mechanism can reduce the packet loss rate but increases latency. So it’s necessary to analyze the performance of reliability and latency for different applications in shipborne wireless sensor networks. In this article, first, we analyze the distribution of the physical-layer packet loss rate for IEEE 802.15.4 sensor network in ship indoor environment. We also present an analysis model based on three-dimensional Markov chain for unslotted CSMA/CA of IEEE 802.15.4 sensor network considering physical-layer packet loss rate and MAC-layer retransmission. We evaluate the effects of three MAC parameters, $\textit {macMinBE}$ , $\textit {macMaxCSMABackoffs}$ , and $\textit {macMaxFrameRetries}$ , on average delay and reliability. The percentage error of the analytical model for delay and reliability are 2.09% and 1.37%, respectively. Our work provides trade-off analysis between average delay and average reliability using the maximum number of retransmission based on the measured data of physical-layer packet loss rate in shipboard environment for different QoS requirements.

Objective Recent policy making aims to prevent health systems, lectronic health record (EHR) vendors, and others from blocking the electronic sharing of patient data necessary for clinical care. We sought to assess the prevalence of information blocking prior to enforcement of these rules. Materials and Methods We conducted a national survey of health information exchange organizations (HIEs) to measure the prevalence of information blocking behaviors observed by these third-party entities. Eighty-nine of 106 HIEs (84%) meeting the inclusion criteria responded. Results The majority (55%) of HIEs reported that EHR vendors at least sometimes engage in information blocking, while 30% of HIEs reported the same for health systems. The most common type of information blocking behavior EHR vendors engaged in was setting unreasonably high prices, which 42% of HIEs reported routinely observing. The most common type of information blocking behavior health systems engaged in was refusing to share information, which 14% of HIEs reported routinely observing. Reported levels of vendor information blocking was correlated with regional competition among vendors and information blocking was concentrated in some geographic regions. Discussion Our findings are consistent with early reports, revealing persistently high levels of information blocking and important variation by actor, type of behavior, and geography. These trends reflect the observations and experiences of HIEs and their potential biases. Nevertheless, these data serve as a baseline against which to measure the impact of new regulations and to inform policy makers about the most common types of information blocking behaviors. Conclusion Enforcement aimed at reducing information blocking should consider variation in prevalence and how to most effectively target efforts.