Jensen–Shannon divergence for visual quality assessment

This paper focuses on some theoretical properties of the Jensen–Shannon divergence (JSD) that well match human visual system (HVS) features. In particular, it is firstly shown that JSD between the probability density function (pdf) of the reference (original) image and the test (distorted) one can be reformulated as a mathematical expansion, independently of the image subject and the distortion kind. Such expansion contains a component of the well-known structural similarity measure (SSIM), some powers of the Weber’s law, and an additional component tied to the skewness of the involved pdfs. This theoretical link with some HVS-based quantities is further stressed by some experimental results showing that JSD has a trend similar to other popular quality assessment measures like SSIM, VIF, and MSE on frequent degradation kinds like JPEG, Additive Gaussian Noise, Gaussian Blur, and JPEG2K. Experimental tests on several images from LIVE database show that the proposed approach can be a valid theoretical and objective support for modeling HVS behavior.     

Modelling of spatio–temporal interaction for video quality assessment

Video services have appeared in the recent years due to advances in video coding and convergence to IP networks. As these emerging services mature, the ability to deliver adequate quality to end-users becomes increasingly important. However, the transmission of digital video over error-prone and bandwidth-limited networks may produce spatial and temporal visual distortions in the decoded video. Both types of impairments affect the perceived video quality. In this paper, we examine the impact of spatio–temporal artefacts in video and especially how both types of errors interact to affect the overall perceived video quality. We show that the impact of the spatial quality on overall video quality is dependent on the temporal quality and vice-versa. We observe that the introduction of a degradation in one modality affects the quality perception in the other modality, and this change is larger for high-quality conditions than for low-quality conditions. The contribution of the spatial quality to the overall quality is found to be greater than the contribution of the temporal quality. Our results also indicate that low-motion talking-head content can be more negatively affected by temporal frame freezing artefacts than other general type of content with higher motion. Based on the results of a subjective experiment, we propose an objective model to predict overall video quality by integrating the contributions of a spatial quality and a temporal quality. The non-linear model shows a very high linear correlation with subjective data.     

FIFA: A fault-injection–fault-analysis-based tool for reliability assessment at RTL level

This paper presents an efficient platform for fault robustness estimation of digital circuits. The proposed platform, named FIFA, was designed as a hardware IP to accelerate the Fault Injection and Fault masking Analysis approach. It supports several fault models as well as single and multiple faults. Synthesis results have shown that the proposed platform can exceed those existent in the literature in terms of area efficiency and performance. In addition, the FIFA platform allows the designer to control complexity and completeness of the analysis process.     

A high-performance,low-power ∑Δ ADC for digital audio applications

A high-performance low-power ∑Δ analog-to-digital converter (ADC) for digital audio applications is described.It consists of a 2-1 cascaded ∑Δ modulator and a decimation filter.Various design optimizations are implemented in the system design,circuit implementation and layout design,including a high-overload-level coefficientoptimized modulator architecture,a power-efficient class A/AB operational transconductance amplifier,as well as a multi-stage decimation filter conserving area and power consumption.The ADC is implemented in the SMIC 0.18-μm CMOS mixed-signal process.The experimental chip achieves a peak signal-to-noise-plus-distortion ratio of 90 dB and a dynamic range of 94 dB over 22.05-kHz audio band and occupies 2.1 mm2,which dissipates only 2.1 mA quiescent current in the analog circuits.     

A high-performance,low-power ∑△ ADC for digital audio applications

A high-performance low-powerΣΔanalog-to-digital converter(ADC) for digital audio applications is described.It consists of a 2-1 cascadedΣΔmodulator and a decimation filter.Various design optimizations are implemented in the system design,circuit implementation and layout design,including a high-overload-level coefficient-optimized modulator architecture,a power-efficient class A/AB operational transconductance amplifier,as well as a multi-stage decimation filter conserving area and power consumption.The ...     

A 65-nm low-noise low-costΣ△modulator for audio applications

正This paper introduces a low-noise low-costΣA modulator for digital audio analog-to-digital conversion. By adopting a low-noise large-output swing operation amplifier,not only is the flicker noise greatly inhibited,but also the power consumption is reduced.Also the area cost is relatively small.The modulator was implemented in a SMIC standard 65-nm CMOS process.Measurement results show it can achieve 96 dB peak signal-to-noise plus distortion ratio(SNDR) and 105 dB dynamic range(DR) over the 22.05-kHz audio band and occupies 0.16 mm~2. The power consumption of the proposed modulator is 4.9 mW from a 2.5 V power supply,which is suitable for high-performance,low-cost audio codec applications.     

A 65-nm low-noise low-cost ∑ △ modulator for audio applications

This paper introduces a low-noise low-cost ∑ △ modulator for digital audio analog-to-digital conversion.By adopting a low-noise large-output swing operation amplifier,not only is the flicker noise grea...     

A 65-nm low-noise low-cost ∑Δ modulator for audio applications

This paper introduces a low-noise low-cost ΣΔ modulator for digital audio analog-to-digital conversion. By adopting a low-noise large-output swing operation amplifier, not only is the flicker noise greatly inhibited, but also the power consumption is reduced. Also the area cost is relatively small. The modulator was implemented in a SMIC standard 65-nm CMOS process. Measurement results show it can achieve 96 dB peak signal-to-noise plus distortion ratio (SNDR) and 105 dB dynamic range (DR) over the 22.05-kHz audio band and occupies 0.16 mm². The power consumption of the proposed modulator is 4.9 mW from a 2.5 V power supply, which is suitable for high-performance, low-cost audio codec applications.     

A 1.1 mW 87 dB dynamic range ΔΣ modulator for audio applications

This paper presents a 1.1 mW 87 dB dynamic range third order AS modulator implemented in 0.18 μm CMOS technology for audio applications.By adopting a feed-forward multi-bit topology,the signal swing at the output of the first integrator can be suppressed.A simple current mirror single stage OTA with 34 dB DC gain working under 1 V power supply is used in the first integrator.The prototype modulator achieves 87 dB DR and 83.8 dB peak SNDR across the bandwidth from 100 Hz to 24 kHz with 3 kHz input signal.     

A 1.1 mW 87 dB dynamic range △∑ modulator for audio applications

This paper presents a 1.1 mW 87 dB dynamic range third orderΔΣmodulator implemented in 0.18μm CMOS technology for audio applications.By adopting a feed-forward multi-bit topology,the signal swing at the output of the first integrator can be suppressed.A simple current mirror single stage OTA with 34 dB DC gain working under 1 V power supply is used in the first integrator.The prototype modulator achieves 87 dB DR and 83.8 dB peak SNDR across the bandwidth from 100 Hz to 24 kHz with 3 kHz input signal.     

A pattern classification proposal for object‐oriented audio coding in MPEG‐4

The future MPEG4 standard will adopt an objectoriented encoding strategy whereby an audio source is encoded at a very low bitrate by adapting a suitable coding scheme to the local characteristics of the signal. One of the most delicate issues in this approach is that the overall performance of the audio encoder greatly depends on the accuracy with which the input signal is classified. This paper shows that the difficult problem of audio classification for objectoriented coding can be effectively solved by selecting a salient set of acoustic parameters and adopting a fuzzy model for each audio object, obtained by a soft computinghybrid learning tool. The audio classifier proposed operates at two levels: recognition of the class to which the input signal belongs (talkspurt, music, noise, signaling tones) and then recognition of the subclass to which it belongs. The results obtained show that fuzzy logic is a valid alternative to the matching techniques of a traditional pattern recognition approach.     

A 0.9–5.4 GHz wideband fast settling frequency synthesizer for 5G based consumer services

In this paper, a frequency synthesizer, based on a type-2, third order phase locked loop (PLL), covering the frequency range of 0.9–5.4 GHz using three voltage controlled oscillators, is implemented using a 0.13-\(\upmu \hbox {m}\) CMOS technology. The PLL has three modes of operation—a high bandwidth mode, a low bandwidth mode and a dynamic mode, in which the bandwidth dynamically changes from a low to a high value, during a frequency jump, and reverts back to low value, once the PLL settles. With a proper choice of bandwidth and timing synchronization during a frequency jump, a worst-case settling time of 3-\(\upmu \hbox {s}\) has been obtained, which is one of the lowest in reported literature. The input clock of the PLL is set to 100 MHz, but it can go as low as 25 MHz without having any effect on its settling time. The PLL consumes 24 mW of power and occupies 0.8 mm\(^2\) of active area.This PLL is expected to be specially useful in wide-bandwidth cognitive radios that require large and fast transitions in the frequency of operation.     

Applications of location–based services: a selected review

This article reviews a selected set of location–based services (LBS) that have been published in the research literature, focussing on mobile guides, transport support, gaming, assistive technology and health. The research needs and opportunities in each area are evaluated and the connections between each category of LBS are discussed. The review illustrates the enormous diversity of forms in which LBS are appearing and the wide range of application sectors that are represented. However, very few of these applications are implemented pervasively on a commercial basis as this is still challenging technically and economically.     

Deep learning and RGB-D based human action,human–human and human–object interaction recognition: A survey

Human activity recognition is one of the most studied topics in the field of computer vision. In recent years, with the availability of RGB-D sensors and powerful deep learning techniques, research on human activity recognition has gained momentum. From simple human atomic actions, the research has advanced towards recognizing more complex human activities using RGB-D data. This paper presents a comprehensive survey of the advanced deep learning based recognition methods and categorizes them in human atomic action, human–human interaction, human–object interaction. The reviewed methods are further classified based on the individual modality used for recognition i.e. RGB based, depth based, skeleton based, and hybrid. We also review and categorize recent challenging RGB-D datasets for the same. In addition, the paper also briefly reviews RGB-D datasets and methods for online activity recognition. The paper concludes with a discussion on limitations, challenges, and recent trends for promising future directions.     

A novel user’s authentication scheme for pervasive on-line media services

Due to the explosive growth of the Internet and the pervasion of multimedia, protection of intellectual property (IP) rights of digital content in transactions induces people’s concerns. Current security requirements and copyright protection mechanisms especially need to work in real-time and on-line for communication and networking. For media service systems in the Internet, user’s authentication is most essential in association with the access control of the media system. The authentication scheme is a trivial but crucial issue for maintaining user’s information. Up to now, many one-time password-based authentication schemes have been proposed. However, none is secure enough. The purpose of a one-time password (OTP) is to make it more difficult to gain unauthorized access to restricted resources. Traditionally static passwords can more easily be obtained by an unauthorized intruder given enough attempts and time. By constantly altering the password, as is done with a one-time password, this risk can be greatly reduced. These schemes are specially fit for media services in the Internet since they will frustrate the attacker’s attempt. Lin, Shen and Hwang proposed a strong-password authentication scheme in association with one-time password by using smart cards, and claimed their scheme can resist guess attack, replay attack, impersonation attack and stolen attack. Later, Ku, Tsai, and Chen showed that Lin-Shen-Hwang’s scheme suffers from a replay attack and a denial-of-service attack. Furthermore, Ku proposed a hash-based strong-password authentication scheme to enhance the security. In this paper, we show the weaknesses and devise some attacks against Ku’s scheme. Then, we revise Ku’s scheme and propose a novel user’s authentication scheme in pervasive on-line media services for current communication and networking.     

Polysaccharide–Peptide Conjugates: A Versatile Material Platform for Biomedical Applications

Natural polymers, such as polysaccharides and proteins, have been widely studied for numerous biomedical applications because of their bioactivity, natural origin, and biodegradability. To address the different needs of a broad spectrum of biomedical applications, natural polymers are modified with or conjugated to small molecular compounds, synthetic and natural polymers, and inorganic nanomaterials and surfaces. Among these hybrid materials, polysaccharide–peptide conjugates have drawn much attention due to their design flexibility, biocompatibility, tunable degradability, and structure similarity to naturally occurring glycoproteins. In the past 20 years, polysaccharide–peptide conjugates have demonstrated the promising potential to address many long-standing medical challenges. Thus, the design, conjugation chemistry and method, and biomedical applications of polysaccharide–peptide conjugates are summarized and discussed in this review. The conjugation techniques are reviewed from the view of the chemical reactions. Meanwhile, some inspiring examples of polysaccharide–peptide conjugates in biomedical applications, including drug delivery systems, nucleic acid delivery carriers, tissue engineering, and antimicrobial applications, are highlighted. Moreover, the outlook on the challenges and demands of polysaccharide–peptide conjugates is also elaborated.     

A co-operative environment for local government: an Internet–Intranet approach

In this paper we present a Web-based, database oriented CSCW system to support information dispersal between different Local Government authorities (Region, Prefecture and Municipalities) and the citizens. The system is implemented around the `shared workspace' notion, a group of directories and files controlled by the users of the workspace. Intranet and Extranet technologies are exploited to enable asynchronous and synchronous co-operation, manipulation of information from heterogeneous sources, security and easy administration, providing in parallel advanced communication facilities.We propose an innovative approach for the development of shared workspaces over WWW, based on state-of-the-art software platforms, integrating WWW and database technologies. The whole system was developed under a project funded by the Greek General Secretariat of Research and Technology and aims in the efficient distribution and management of information between and within different types of local authorities (Municipalities, Prefectures).     

A survey of ‘young social’ and ‘professional’ users of location-based services in the UK

The objective of this study was to assess the response to location-based services (LBS) by three key demographic groups within the United Kingdom. This study took the form of a survey of relevant demographics, attitudes and consumer behaviour undertaken via a web-based survey. Results are based on over 1200 respondents, filtered and segmented into three demographic groups who are typically early adopters of new technology. There were positive attitudes towards a range of LBS, with the major exception being location-based advertising. There were mixed views towards location-based gaming and safety camera information. There were low levels of awareness of many services. The levels of use were typically under 20% for all types of LBS.     

Digital sinusoidal PWMs for a micro-controller based single-phase inverter,Part 2: Performance assessment–experimental

The performance, including efficiency, harmonics and dead-time effect of the three major digital sinusoidal pulse width modulations (DSPWMs) presented in Part 1 are investigated in this study using a 2 kVA single-phase full-bridge inverter. Each DSPWM is implemented using a low-cost 8-bit micro-controller and the effect of different switching frequencies on the inverter performance is analysed and the inverter switching, conduction and transformer losses investigated. The experimental results confirm the validity of the mathematical and simulation analysis presented in Part 1. The work shows that the type of DSPWM used for a single-phase full-bridge inverter and the switching frequency selected can have a significant effect on the inverter performance and that switch and transformer losses make up the majority of the inverter losses.