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A new method for creating instruction level energy models for pipelined processors is introduced. This method is based on measuring the instantaneous current drawn by the processor during the execution of the instructions. An appropriate instrumentation set up was established for this purpose. According to the proposed method the energy costs (base and inter-instruction costs) are modeled in relation to a reference instruction (e.g. NOP). These costs incorporate inter-cycle energy components, which cancel each other when they are summed to produce the energy consumption of a program resulting in estimates with high accuracy. This is confirmed by the results. Also the dependencies of the energy consumption on the instruction parameters (e.g. operands, addresses) are studied and modeled in an efficient way. [ABSTRACT FROM AUTHOR]

The implementation and validation of a 5-GHz wireless LAN modem based on the HIPERLAN/2 standard is presented. In modern wireless communication systems, there is a demand for higher flexibility and more computational efficiency. Therefore the emphasis of this work is on the hardware­software structure of the developed modem and its processes, in order to offer a good balance of these requirements. In order to efficiently design and validate the behavior of the modem, a behavioral model was developed in UML (Unified Modelling Language) as a part of the overall HIPERLAN/2 system's model. The processes of the modem were implemented in an instruction-set processor and custom hardware, combining the advantages of both software and hardware implementations. The communication between the software and hardware parts of the modem is achieved through a specialized programmable interface unit. The UML-based model of the actual HIPERLAN/2 system is used in order to validate the modem's behavior, using scenarios from in-field usage (such as transfer of data using FTP or HTTP). Furthermore, the validation of the algorithms implemented within the modem was based on this system model, and performed through the use of a custom-validation framework. This framework produces patterns for the validation of the modem's algorithms, at three different development phases (algorithmic, HDL, FPGA-based prototyping), derived from the simulation of the system model in a consistent and automatic way. Implementation figures and co-simulation results for the developed wireless LAN modem are also given. [ABSTRACT FROM AUTHOR]

The authors present the architecture of a low-power system-on-chip (SoC) that implements baseband processing as well as the medium access control and data link control functionalities of a 5 GHz wireless system. The design is based on the HIPERLAN/2 wireless LAN standard, but it also covers critical processing requirements of the IEEE 802.11a standard. The options, constraints and motivations for the taken design decisions are presented, and the followed design steps, starting from the system specifications up to the architecture definition and the system implementation, are explained. The system's functionality covers both mobile terminal and access point devices. A critical design task in such systems is the assignment of the target system' s tasks on the different types of processing elements available. Processor cores, dedicated hardware as well as memory elements and advanced bus architectures are used in order to achieve the target implementation. The architecture is targeted for a low-power SoC platform, due to the fact that power consumption is a critical parameter in electronic portable system design where excess power dissipation can lead to expensive and less reliable systems. A system prototype has been developed on a FPGA-based platform (including microprocessor modules). This FPGA-based prototype is currently being migrated to a SoC, which requires that the treatment of important issues such as clock handling, synthesis, testability and debugging is addressed. [ABSTRACT FROM AUTHOR]

Discusses a study which presented an analytical model for the complementary metal-oxide-semiconductor (CMOS) short-circuit energy dissipation. Information on a method for the evaluation of the inverter short-circuit energy dissipation; Discussion on the extension of the proposed inverter model to static CMOS gates; Results of the study.

Studies different static CMOS implementations of digital logic functions with power and power-delay product as criteria. Probabilistic methods in estimating the average power dissipation; Use of statistics, based on power and delay measurements, to achieve more accurate results.

A significant part of the power dissipation in CMOS digital circuits is due to the short-circuit currents. In this paper an accurate analytical model for the evaluation of the CMOS short-circuit power dissipation, on the basis of a CMOS inverter, is presented. The innovation of the proposed approach against previous works is due to the accurate, analytical expressions of the inverter output waveform which include for the first time the effects of both transistor currents and the gate-to-drain coupling capacitance. The α-power law MOS model which considers the carriers' velocity saturation effects of short-channel devices is used. The results produced by the suggested model show very good agreement with SPICE simulations. [ABSTRACT FROM AUTHOR]

Evaluates several static and dynamic complementary metal oxide semiconductors circuit design styles in terms of area, propagation delay and power dissipation. Importance of selection of basic circuit approach and topology in the design of a very large scale integration integrated circuits.

Sleep and circadian disruptions are prominent symptoms of bipolar disorder (BD) and potential targets for adjunctive interventions. The aim of this review was to appraise the effectiveness of psychological and behavioural interventions in BD that target sleep and circadian rhythms, as reported by randomised controlled trials. Nineteen studies met the inclusion/exclusion criteria. They were summarised via narrative synthesis and meta-analysis wherever appropriate. Six studies delivered bright light therapy, five interpersonal and social rhythm therapy, two blue-light blocking glasses, one cognitive behavioural therapy for insomnia, one total sleep deprivation, and four combination treatments. More than half of the studies (N = 10, 52 %) did not measure sleep or circadian rhythms despite being the principal target of the intervention. Overall, the evidence base for the effectiveness of these interventions was limited. There was a small number of studies for each intervention, and a lack of consistency in protocols and outcomes. Meta-analysis was possible for the effect of bright light therapy on depression, revealing a medium-to-large post-treatment effect (Nc = 6; g=-0.74 [95 % CI=-1.05 to -0.42], p < 0.001)., (Copyright © 2021. Published by Elsevier Ltd.)

Sleep-restriction therapy (SRT) has been shown to improve insomnia symptoms by restricting sleep opportunity. Curtailment of time in bed affects the duration and consolidation of sleep, but also its timing. While recent work suggests that people with insomnia are characterised by misalignment between circadian and behavioural timing of sleep, no study has investigated if SRT modifies this relationship. The primary aim of the present study was to examine change in phase angle after 2 weeks of SRT. As a secondary aim, we also sought to assess the effect of SRT on psychomotor vigilance. Following a 1-week baseline phase, participants implemented SRT for 2 consecutive weeks. Phase angle was derived from the difference between the decimal clock time of dim light melatonin onset (DLMO) and attempted sleep time. Secondary outcomes included vigilance (assessed via hourly measurement during the DLMO laboratory protocol), sleep continuity (assessed via sleep diary and actigraphy), and insomnia severity. Eighteen participants meeting insomnia criteria (mean [SD] age 37.06 [8.99] years) took part in the study. Consistent with previous research, participants showed robust improvements in subjective and objective sleep continuity, as well as reductions in insomnia severity. The primary outcome (phase angle) was measurable in 15 participants and revealed an increase of 34.8 min (~0.58 hr; 95% confidence interval [CI] 0.01-1.15) from baseline to post-treatment (mean [SD] 2.27 [0.94] versus 2.85 [1.25] hr). DLMO remained relatively stable (20:49 versus 21:01 hours), while attempted sleep was 46.8 min later (~0.78 hr; 95%CI 0.41-1.15; 23:05 versus 23:52 hours). For psychomotor vigilance, reaction time was delayed (by 52.71 ms, 95% CI 34.44-70.97) and number of lapses increased (by 5.84, 95% CI 3.93-7.75) after SRT. We show that SRT increases phase angle during treatment, principally by delaying the timing of sleep attempt. Future studies are needed to test if an increase in phase angle is linked to clinical improvement. Finally, reduction in vigilance after SRT appears to be of similar magnitude to normal sleepers undergoing experimental sleep restriction, reinforcing the importance of appropriate safety advice during implementation., (© 2020 European Sleep Research Society.)

Study Objectives: We sought to examine the impact of digital cognitive behavioral therapy (dCBT) for insomnia on both self-reported cognitive impairment and objective cognitive performance., Methods: The Defining the Impact of Sleep improvement on Cognitive Outcomes (DISCO) trial was an online, two-arm, single-blind, randomized clinical trial of dCBT versus wait-list control. Participants were aged 25 years and older, met DSM-5 diagnostic criteria for insomnia disorder, and reported difficulties with concentration or memory. Assessments were carried out online at baseline, and 10 and 24 weeks post-randomization. The primary outcome measure was self-reported cognitive impairment, assessed with the British Columbia Cognitive Complaints Inventory (BC-CCI). Secondary outcomes included tests of cognitive performance, insomnia symptoms, cognitive failures, fatigue, sleepiness, depression, and anxiety., Results: Four hundred and ten participants with insomnia were recruited and assigned to dCBT (N = 205) or wait-list control (N = 205). At 10 weeks post-randomization the estimated adjusted mean difference for the BC-CCI was -3.03 (95% CI: -3.60, -2.47; p < 0.0001, d = -0.86), indicating that participants in the dCBT group reported less cognitive impairment than the control group. These effects were maintained at 24 weeks (d = -0.96) and were mediated, in part, via reductions in insomnia severity and increased sleep efficiency. Treatment effects in favor of dCBT, at both 10 and 24 weeks, were found for insomnia severity, sleep efficiency, cognitive failures, fatigue, sleepiness, depression, and anxiety. We found no between-group differences in objective tests of cognitive performance., Conclusions: Our study shows that dCBT robustly decreases self-reported cognitive impairment at post-treatment and these effects are maintained at 6 months., (© Sleep Research Society 2020. Published by Oxford University Press on behalf of the Sleep Research Society. All rights reserved. For permissions, please e-mail journals.permissions@oup.com.)

Cognitive behavioral therapy for insomnia (CBT-I) is a treatment with moderate to large effects. These effects are believed to be sustained long-term, but no systematic meta-analyses of recent evidence exist. In this present meta-analysis, we investigate long-term effects in 30 randomized controlled trials (RCTs) comparing CBT-I to non-active control groups. The primary analyses (n = 29 after excluding one study which was an outlier) showed that CBT-I is effective at 3-, 6- and 12-mo compared to non-active controls: Hedges g for Insomnia severity index: 0.64 (3 m), 0.40 (6 m) and 0.25 (12 m); sleep onset latency: 0.38 (3 m), 0.29 (6 m) and 0.40 (12 m); sleep efficiency: 0.51 (3 m), 0.32 (6 m) and 0.35 (12 m). We demonstrate that although effects decline over time, CBT-I produces clinically significant effects that last up to a year after therapy., (Copyright © 2019 Elsevier Ltd. All rights reserved.)

It is well-established that cognitive behavioural therapy for insomnia (CBT-I) improves self-reported sleep disturbance, however the impact on objective sleep is less clear. This meta-analysis aimed to quantify the impact of multi-component CBT-I on objective measures of sleep, indexed via polysomnography (PSG) and actigraphy. Fifteen studies met inclusion criteria. Following appraisal for risk of bias, extracted data were meta-analysed using random-effects models. The quality of the literature was generally high, although reporting of methodological detail varied markedly between studies. Meta-analyses found no evidence that CBT-I reliably improves PSG-defined sleep parameters. Actigraphy evidence was more mixed; with a small effect for reduction in sleep onset latency (Hedge's g = -0.28 [95% confidence interval (CI) -0.51 to -0.05], p = 0.018) and a moderate effect for reduction in total sleep time (TST) (Hedge's g = -0.51 [95% CI -0.75 to -0.26], p < 0.001). In contrast, and consistent with recent meta-analyses, CBT-I was associated with robust improvements in diary measures of sleep initiation and maintenance (Hedge's g range = 0.50 to 0.79) but not TST. While the literature is small and still developing, the sleep benefits of CBT-I are more clearly expressed in the subjective versus objective domain., (Copyright © 2019. Published by Elsevier Ltd.)