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Recently, we have observed an exponential increase of user-generated content (UGC) videos. The distinguished characteristic of UGC videos originates from the video production and delivery chain, as they are usually acquired and processed by non-professional users before uploading to the hosting platforms for sharing. As such, these videos usually undergo multiple distortion stages that may affect visual quality before ultimately being viewed. Inspired by the increasing consensus that the optimization of the video coding and processing shall be fully driven by the perceptual quality, in this paper, we propose to study the quality of the UGC videos from both objective and subjective perspectives. We first construct a UGC video quality assessment (VQA) database, aiming to provide useful guidance for the UGC video coding and processing in the hosting platform. The database contains source UGC videos uploaded to the platform and their transcoded versions that are ultimately enjoyed by end-users, along with their subjective scores. Furthermore, we develop an objective quality assessment algorithm that automatically evaluates the quality of the transcoded videos based on the corrupted reference, which is in accordance with the application scenarios of UGC video sharing in the hosting platforms. The information from the corrupted reference is well leveraged and the quality is predicted based on the inferred quality maps with deep neural networks (DNN). Experimental results show that the proposed method yields superior performance. Both subjective and objective evaluations of the UGC videos also shed lights on the design of perceptual UGC video coding.

In this paper, a reversible data hiding algorithm for audio files based on code division multiplexing (CDM) is proposed. In the scheme, the orthogonal spreading sequences are employed to carry the embedding data, and the host audio file can also be recovered completely after the secret message has been extracted accurately. At the same time, according the orthogonal character of the spreading sequences, the secret message can be embedded into the audio files repeatedly, and most elements of the spreading sequences are mutually canceled in the process of multi-level data embedding, which maintains the audio file in good auditory even at high data embedding capacity. Moreover, only the receiver who holds the same spreading sequences, as the sender can restore the embedded data, which enhance the security of the proposed scheme. As shown in the experimental results, the CDM based reversible data hiding (RDH) algorithm for audio files can achieve higher data embedding capacity at the same audio distortion compared with those state-of-the-art audio RDH algorithms.

As people increase their dependency on mobile applications and services, saving power consumption of mobile devices becomes an important challenge for supporting video streaming applications. This paper investigates how to minimize the power consumption of an organic light-emitting diode (OLED) display when displaying a video under consideration for the user’s visual experience. We first model the minimization problem as an OLED video scaling optimization problem. We then propose an algorithm to solve the optimization problem and prove that the algorithm is optimal in terms of power savings. We next introduce an energy-saving cloud service based on the algorithm. Finally, the results of the extensive experiments conducted on a commercial mobile smartphone with four real-world videos to evaluate the performance of the proposed algorithm are very encouraging.

Cinema provides ‘privileged access’ ( Zubrycki 2011 ) into trans lives, recording and revealing private life experiences and moments that might never be seen, nor heard and after the time had passed, only present in memory and body for the individuals involved. Film, a temporal medium, creates theoretical issues, both in the presentation and representation of the trans body and for audiences in viewing the images. Specific narrative, stylistic and editing techniques including temporal disjunctions, may also give audiences a distorted view of trans bodily narratives that encompass a lifetime. Twenty first century cinema is simultaneously creating and erasing the somatechnical potentialities of trans. This article will explore temporal techniques in relation to recent trans cinema, comparing how three different filmmakers handle trans narratives. Drawing upon recent films including the Trans New Wave ( Ford 2014 , 2016a , 2016b ), such as the experimental animated autoethnographic short film Change Over Time (Ewan Duarte, United States, 2013), in tandem with the feature film 52 Tuesdays (Sophia Hyde, Australia, 2013), I will analyse the films as texts which show how filmmakers utilise temporality as a narrative and stylistic technique in cinematic trans narratives. These are texts where cinematic technologies converge with trans embodiment in ways that are constitutive of participants and audiences' understanding of trans lives. This analysis will be contrasted with the use of temporal displacement as a cinematic trope of negative affect, disembodiment and societal disjunction in the feature film Predestination (The Spierig Brothers, Australia, 2014), providing a further basis for scholarly critique of cinematic somatechnics in relation to the trans body.

Compared with traditional two-stage class-D audio amplifier, audio amplifier based on cycloconverter-type single-stage inverter (CSSI) has advantages of high efficiency and no bus voltage pumping (BVP). However, CSSI requires complex active clamp circuits for the current commutation of cycloconverter, especially for multichannel amplification. In this letter, a 2.1-channel switching amplifier with dc/high-frequency-ac (HFAC) mixed power supply is proposed, where CSSI is used as low-frequency audio channel amplifier and two class-D amplifiers are used as high-frequency audio channel amplifiers. With dc/HFAC mixed power supply, the proposed 2.1-channel switching amplifier does not require additional active clamp circuits for current commutation of cycloconverter. Besides, wide range soft switching of cycloconverter switches can be achieved. Benefiting from single-stage power conversion of low-frequency audio channel and wide range soft switching of cycloconverter switches, high efficiency of the proposed 2.1-channel amplifier is achieved. Without BVP, low voltage stress of switches and low distortion of low-frequency audio signal are realized in the proposed 2.1-channel amplifier. A 200-W prototype is presented to verify the analysis results.

An ac/dc + dual active bridge (DAB) circuit was found as one solution for the high-efficiency and high-power-density electric vehicle charger. One control option is to let the ac/dc part only convert the grid voltage to a double-line-frequency folded sine wave and let the DAB stage handle both the power factor (PF) and power delivery. While conventional single-phase-shift tends to lose zero-voltage switching (ZVS) at light load and the variable-switching-frequency dual-phase-shift (DPS) sacrifices the light-load performance, this letter proposes a multiple-phase-shift control, which allows for a fixed-switching-frequency triple-phase-shift (TPS) control at the light load to enhance the grid power quality. At medium- and heavy-load conditions, a phase-shift jump from TPS to DPS is performed to reduce the circulating current and improve efficiency. The proposed control strategy secures ZVS, realizes unity PF accurately and minimizes the control complexity. Experimental results on a SiC-based 7.2-kW charger validated its effectiveness and the smooth transition between the heavy load and light load.

This paper presents the design and implementation of a miniaturized high-voltage power supply with power factor correction (PFC) for atmospheric-pressure plasma jet (APPJ) applications. The sinusoidal output frequency and voltage of the power supply can be controlled independently from 16 to 24 kHz and from 1 to 10 kVpeak, respectively. A helium APPJ load is used to assess the performance of the developed power supply. It is shown that the developed high-voltage power supply operates effectively, and the designed PFC converter improves the input current distortion of the power supply. Not only the power factor of the power supply is increased from 0.41 to 0.95, but it also provides a low-ripple DC voltage, which reduces the high-voltage ripple of the output from 730 to 50 Vp-p. In this paper, the proposed design integrates the PFC converter into the high-voltage power supply so that the developed power supply has better electrical characteristics and the overall power supply can be significantly miniaturized.

The electric guitar is an ubiquitous part of contemporary consumer culture. In this Marketplace Icons contribution, we illuminate the iconicity of the electric guitar and what lies behind its thick layers of distorted riffs, mad soloing escapades and eccentric onstage performances, specifically within the rock genre. The genesis of electric guitar playing involves a series of technological alterations of the guitar that freed it from a mere background instrument allowing for new musical roles. It quickly became apparent that all the technical solutions designed to get rid of what was defined as unwanted noise could be turned “against” the clean tone and instead be used to create a unique sound. The control of these noise elements, such as feedback and distortion, became a core element of mastering the modern electric guitar. Rather than just being a marketplace icon, we argue that the electric guitar is fetishized because both its audio quality – the loudness and the potential roughness of the sound – and...

Modern digital hearing aids have provided improved fidelity over those of earlier decades for speech. The same however cannot be said for music. Most modern hearing aids have a limitation of their “front end,” which comprises the analog-to-digital (A/D) converter. For a number of reasons, the spectral nature of music as an input to a hearing aid is beyond the optimal operating conditions of the “front end” components. Amplified music tends to be of rather poor fidelity. Once the music signal is distorted, no amount of software manipulation that occurs later in the circuitry can improve things. The solution is not a software issue. Some characteristics of music that make it difficult to be transduced without significant distortion include an increased sound level relative to that of speech, and the crest factor- the difference in dB between the instantaneous peak of a signal and its RMS value. Clinical strategies and technical innovations have helped to improve the fidelity of amplified music and these include a reduction of the level of the input that is presented to the A/D converter.

Although semiconductor technologies have displaced vacuum-tube devices in nearly all fields of electronics, vacuum tubes are still widely used in professional guitar amplifiers. A major reason for this is that electric-guitar amplifiers are typically overdriven, that is, operated in such a way that the output saturates. Vacuum tubes distort the signal in a different manner compared to solid-state electronics, and human listeners tend to prefer this. This might be because the distinctive tone of tube amplifiers was popularized in the 1950s and 1960s by early rock and roll bands, so musicians and listeners have become accustomed to tube distortion. Some studies on the perceptual aspects of vacuum-tube and solid-state distortion have been published (e.g., Hamm 1973; Bussey and Haigler 1981; Santo 1994). Despite their acclaimed tone, vacuum-tube amplifiers have certain shortcomings: large size and weight, poor durability, high power consumption, high price, and often poor availability of spare parts. Thus, it is not surprising that many attempts have been made to emulate guitar tube amplifiers using smaller and cheaper solid-state analog circuits (e.g., Todokoro 1976; Sondermeyer 1984). The next step in the evolution of tube-amplifier emulation has been to simulate the amplifiers using computers and digital signal processors (DSP). A primary advantage of digital emulation is that the same hardware can be used for modeling many different tube amplifiers and effects. When a new model is to be added, new parameter values or program code are simply uploaded to the device. Furthermore, amplifier models can be implemented

During turning of cylindrical workpieces with different diameters the industry often uses standard clamping systems. These systems are economic and able to clamp different diameters. Their benefit is that valuable time for jaw changing may be saved. Therefore a special interest lies in studies which allow the minimization of distortion by using these universal clamping systems. In this study a method is presented using three-jaw-chucks to minimize the wallthickness-deviation of bearing rings caused by the turning process. The experimental approach considers a specific clamping sequence in combination with a variation of the clamping pressure. Additionally the use of a form-locking clamping system, which allows a clear decrease of the necessary clamping pressure, will be examined. As a major result an optimized specific clamping sequence is presented, using segment jaws which will minimize the distortion caused by a varying depth of cut on the outer side of bearing rings. Verzugsbeherrschung in Drehprozessen mit Standard-Spannsystemen Bei der Drehbearbeitung von zylindrischen Werkstucken werden in der Industrie oftmals Standard-Spannsysteme eingesetzt. Diese Spannsysteme sind kostengunstig und in der Lage Bauteile mit unterschiedlichen Durchmessern ohne Backenwechsel zu spannen. Aus diesem Grund besteht ein besonderes Interesse darin die ungewollte Verformung der Bauteile bei der Drehbearbeitung mit Standard-Spannsystemen zu verringern. Unter anderem wird eine Methode zur Minimierung der Wandstarkeschwankung von Kugellagerringen unter Verwendung eines 3-Backen-Spannsystems vorgestellt. Hierzu wird eine spezielle Spannfolge in Kombination mit einer Spanndruckvariation eingesetzt. Zusatzlich wird in einer weiteren Spannfolge der Einsatz eines formschlussigen Spannsystems, welches eine deutliche Reduzierung des Spanndrucks ermoglicht, untersucht. Eine dritte Spannfolge setzt Segmentbacken mit dem Ziel ein den Ausenradius von Ringen nach der Drehbearbeitung moglichst konstant zu halten.

Electric guitarists prefer analog distortion effects over many digital implementations. This article suggests reasons for this and proposes that detailed study of the electrical physics of guitar distortion circuits provides insight to design more accurate emulations. This work introduces real- time emula- tion applied to guitar audio amplifi ers in the form of a tutorial about relevant numerical methods and a case study. The results here make a compelling case for simulating musical electronics using numerical methods in real time. Analog guitar distortion effect devices known as solid- state distortion boxes commonly include a diode clipper circuit with an embedded low- pass fi lter. These distortion- effect devices can be mod- eled and accurately simulated as Ordinary Differen- tial Equations (ODEs). A survey and a comparison of the basic numerical integration methods are presented as they apply to simulating circuits for audio processing, with the widely used diode clipper presented as an example. A dedicated simulator for the diode clipper has been developed to compare several numerical integration methods and their real- time feasibility. We found that implicit or semi- implicit solvers are preferred, although the prefi lter / static nonlinearity approximation comes surprisingly close to the actual solution.

Automatic generation of play lists for commercial broadcast radio stations has become a major research topic. Audio identification systems have been around for a while, and they show good performance for clean audio files. However, songs transmitted by commercial radio stations are highly distorted to cause greater impact on the casual listener. This impact helps increase the probability that the listener will stay tuned in, but the price we have to pay is a severe modification in the audio itself. This causes the failure of traditional identification systems. Another problem is the fact that songs are never played from the beginning to the end. Actually, they are put on the air several seconds after their real beginning and almost always under the voice of a speaker. The same thing happens at the end. In this article, we present the RAA project, which was conceived to deal with real broadcast audio problems. The idea behind this project is to extract automatically an audio fingerprint (the so-called AudioDNA) that identifies the fragment of audio. This AudioDNA has to be robust enough to appear almost the same under several degrees of distortion. Once this AudioDNA is extracted from the broadcast audio, a matching algorithm is able to find its fragments inside a database. With this approach, the system can find not only a whole song but also small fragments of it, even with high distortion caused by broadcast (and DJ) manipulations.

The authors were very thorough in the intense study that they performed in this paper. The discusser was impressed with the amount of detail, research, and study that went into this paper. It pinpoints the need to study and design relative protection for people who happen to be in the wrong place at the wrong time. These comments are intended to offer suggestions for improvement and clarification of this paper. It is this discusser’s feeling that an abstract should be short and easy to read, in order to invite those with mild interest in the subject matter to read and study the rest of the paper. It appears to the discusser that such terms as ‘‘fenestrations vacated by fractured glazing’’ would be more clear and attractive to the reader if reduced to words like ‘‘broken windows’’ (Part of the discusser’s function in his practice as a Forensic Engineer is to report a technical cause of damage in such terminology that the nontechnician can understand it.) After a bit of confusion on the part of the discusser, it was realized that photos 3 and 4 had been transposed. After that, the explanations became understandable. In the same vein, it was realized that NW 5th Street was really a north-south dividing line, not an east-west dividing line. Also, the discusser was looking for some sort of data on eye-related injuries, but it was nowhere to be found. Finally, the discusser congratulates the authors for this study, which he hopes will work towards additional study to find safer fenestration materials and techniques.

A 10-b 20-Msample/s analog-to-digital converter fabricated in a 0.9- mu m CMOS technology is described. The converter uses a pipelined nine-stage architecture with fully differential analog circuits and achieves a signal-to-noise-and-distortion ratio (SNDR) of 60 dB with a full-scale sinusoidal input at 5 MHz. It occupies a 8.7 mm/sup 2/ and dissipates 240 mW. >

In the middle of the last century, R. L. De Valois designed and built a unique and effective amplifier based on the newly developed field-effect transistor (FET). This amplifier has many beneficial qualities for amplifying the signals of neurons with minimal disturbance. We have used this amplifier successfully for more than three decades. We describe the circuitry of the De Valois amplifier and provide performance specifications. The FET amplifier is one of De Valois's contributions to visual neurophysiology; we share the design in his honor, with the hope that it might prove useful to others.

For original paper see C. Chan, H. Ling and O. Choy, ibid., vol.30, no.9, pp.1018-19 (1995). The goal of the original paper was to develop a novel FM demodulator based on a Gilbert multiplier that can operate with a single 1.2 V battery. In this Comment the author suggests that the original paper contained some errors and that the cell developed was not at all novel and is actually very well known. A reply by the original authors is included.

An electronic musical instrument shaped like an electric guitar sounds individual notes that are synthesized to sound like an electric guitar. These notes may either be selected randomly selected by a player or from segments of prearranged musical tracks. The instrument provides for maintaining the tempo of manually played or preprogrammed notes, synchronizing the transitions between sequentially selected musical tracks, overlaying manual notes on the tracks, and a number of electric guitar-like sound effects including vibrato, chorus, overdrive, slurs and soft picks.

The invention relates to a subscriber telephone set with amplified reception loudspeaker. To avoid distortion of the signals transmitted to this loudspeaker should the power supply of the line be insufficient, it is provided for the amplifier feeding this loudspeaker to have its gain controlled by a signal resulting from the measurement of current passing through a shunt regulator serving for supplying the amplifier.

A system for the selection and recall of individual phase, pickup selection, tone, overdrive and volume control for each of a plurality of pickup coils in electric guitars. These various controls for the humbucking pickup coils in the guitar are initially set by either rotary or toggle switches to achieve a particular combination of switch settings. Additional controls then allow the musician to write the states of these various controls into digital memory contained within the guitar. Several such combinations may be memorized and then recalled at a later time by actuation of a memory address selection switch which then reads the contents of the memory for a particular combination of settings and internally causes the various controls to reset themselves to this particular combination of settings.

A description is given of a fiber optic link for digital audio interfaces that is able to transmit 3 Mb/s biphase signals up to 10 m with the pulse-width distortion at less than +or-25 ns. The fiber optic transmitting module consists of a GaAlAs light-emitting diode emitting at 660 nm wavelength, and a transmitting IC. These chips are mounted on a lead frame and molded by a clear resin. This molded unit is assembled into a receptacle that has a self-tapping hole for easy attachment to the rear panel of audio equipment. It also has preformed pins for presetting to the printed circuit board before soldering. The fiber-optic receiving module consists of a Si-p-i-n photodiode, and a receiving IC, and is assembled with these chips in the same way as the transmitting module. The conductive receptable electromagnetically shields the receiving module, but a nonconductive spacer attached to the receptacle electrically isolates it from rear panel. The link is intended for use in compact disk (CD) players, digital audio tape (DAT) recorders, video cassette recorders (VCRs), and digital receivers. >

It is generally recognized that if overload can be prevented, reverse-bias (gain decreases as emitter current decreases) in gain-controlled transistorized video IF amplifiers is preferred because of the superior bandpass stability throughout the AGC range and because of the uniformity in AGC tracking. Evaluation of overload distortion as a function of gain-control and source impedance indicates what signal levels can be tolerated at various operating conditions. Design based on overload evaluation has resulted in four-stage, 45 MHz amplifiers for color receivers having 70 db power gain, 60 db gain reduction capability, signal handling capability of 400 millivolts at the IF input of 50 ohms, and linear output capability of 3. 5 volts of video at 2900 ohms.

The output signals of a phonograph and of an auxiliary audio signal source, such as a high impedance microphone, electric guitar, or the like, are combined before being fed to the amplifier of the phonograph, whereby the combined signals are amplified without distortion, and are fed to one or more speakers, thus audibly reproducing the phonograph recording with the auxiliary sound signal superimposed thereover. The device which combines the signals includes means for suppressing the base frequencies in the auxiliary signal, and for selectively adjusting the amplitudes of the two signal components.

When visiting a strange church, we can identify the organ as a pipe organ or an electronic organ with just a few minutes of listening (and without visual inspection). A run on the pedal organ will show the usual organ loudspeaker to cease radiating below 60 Hz. Modulation distortion will show that the all important middle octave (261–525 Hz) is being radiated from the same cone as the low tones. The lack of high‐frequency power radiation is noticeable. We deem these faults are caused by the fact that organ loudspeakers have not been designed, they have just happened. Dr. J. E. Bensen reported (in 1959) an experiment in the Sydney (Australia) Town Hall which proves this need not be true. We have repeated Dr. Bensen's experiment in the First Methodist Church, Colorado Springs, Colorado, and verified his conclusion. To prove that the recent loudspeaker revolution can make the electronic organ viable, we use a Moog Synthesizer to simulate several pedal and great organ stops.

An electronic amplifying apparatus intended for electric music instruments (primarily guitar), with switchable circuitry offering an improved, specialized circuit for the enhancement of solo playing in addition to customary simple amplification. In the lead (or solo) mode of operation, the circuit will synthesize particular sustain and distortion characteristics and add them to the tone of the instrument (guitar, electric piano, microphone, etc.) to produce a more flexible and expressive sound for solo playing than the sound of the instrument normally amplified. Switching and control circuitry enable the musician to return to a conventional amplified tone which would be preferred for rhythm (or chordal) playing.

The high frequency translation losses in record reproduction which Professor Hunt has quoted from a former paper of mine apply only to soft plastic‐coated recording disks such as are used for instantaneous play‐back recording. They do not hold and are very much less on the relatively hard material of which commercial transcription records are pressed. The RCA reproducer was designed and primarily intended for use with these hard commercial pressings.With reference to the frequency characteristic which is to be adopted and which is being used for the new Orthocoustic broadcast transcription records and which Professor Hunt contends represents too much high frequency pre‐emphasis, let me say that this program was started solely with the idea of producing ultra‐high quality disks. It seems inconsistent that such a characteristic would be used if it resulted in objectionable distortion. The direct purpose in accenting the high frequency range in recording and attenuating it in reproduction is of course to red...