Further Results on (a, d) -total Edge Irregularity Strength of Graphs

ليكن  رسمًا بيانيًا بسيطًا على رؤوس l وحواف m مع إجمالي h -  وضع العلامات  . فان   تسمى (ا,د)- وسم غير منتظم للحافة الإجمالية إذا وجد تطابق متقابل وليكن   معرفة بواسطة   لكل   , حيث  . كذلك قيمة  يقال لها وزن الحافة . يشار الى (ا,د)-اجمالي قوة عدم انتظام الحواف للرسم البياني G ب  وهي اقل h التي يقبلها G   للحافة -(ا,د) الغير منتظمة للعلامة-h . في هذه المقالة تم فحص,  لبعض عائلات الرسم البياني الشائعة. بالاضافة الى ذلك تم حل المسالة المفتوحة  بشكل ايجابي. م تسمى ρ (أ ، د) - وسم غير منتظم للحافة الإجمالية إذا كان هناك تطابق واحد لواحد ، قل ψ: E (G) → {a ، a + d ، a + 2d ،… + a + (m- 1) د} محدد بواسطة ψ (uv) = ρ (u) + ρ (v) + ρ (uv) لجميع uv∈E (G) ، حيث a≥3 ، d≥2. أيضًا ، يُقال إن القيمة ψ (uv) هي وزن حافة الأشعة فوق البنفسجية. يشار إلى قوة عدم انتظام الحافة الإجمالية (أ ، د) للرسم البياني G بواسطة (a ، d) -tes (G) وهي أقل h التي يقبلها G (أ ، د) - علامة h غير منتظمة للحافة. في هذه المقالة ، يتم فحص (أ ، د) -tes (G) لبعض عائلات الرسم البياني الشائعة. بالإضافة إلى ذلك ، يتم حل المشكلة المفتوحة (3،2) - tes (K_ (m ، n)) ، m ، n> 2 بشكل إيجابي.Consider a simple graph   on vertices and edges together with a total  labeling . Then ρ is called total edge irregular labeling if there exists a one-to-one correspondence, say  defined by  for all  where  Also, the value  is said to be the edge weight of . The total edge irregularity strength of the graph G is indicated by  and is the least  for which G admits   edge irregular h-labeling.  In this article,   for some common graph families are examined. In addition, an open problem is solved affirmatively

Omission responses in local field potentials in rat auditory cortex

Background Non-invasive recordings of gross neural activity in humans often show responses to omitted stimuli in steady trains of identical stimuli. This has been taken as evidence for the neural coding of prediction or prediction error. However, evidence for such omission responses from invasive recordings of cellular-scale responses in animal models is scarce. Here, we sought to characterise omission responses using extracellular recordings in the auditory cortex of anaesthetised rats. We profiled omission responses across local field potentials (LFP), analogue multiunit activity (AMUA), and single/multi-unit spiking activity, using stimuli that were fixed-rate trains of acoustic noise bursts where 5% of bursts were randomly omitted. Results Significant omission responses were observed in LFP and AMUA signals, but not in spiking activity. These omission responses had a lower amplitude and longer latency than burst-evoked sensory responses, and omission response amplitude increased as a function of the number of preceding bursts. Conclusions Together, our findings show that omission responses are most robustly observed in LFP and AMUA signals (relative to spiking activity). This has implications for models of cortical processing that require many neurons to encode prediction errors in their spike output

Temporal regularity in audition

Sound, by its very nature, is a temporal phenomenon. Everything from the perception of pitch to the sense of closure at the end of a symphony, relies on the brain's ability to integrate information over time. Ultimately it is perception that enables the richness of our interactions with the world around us, and it is a remarkable feat that the brain can quickly and accurately sift through the flood of information entering the ears to construct a coherent yet dynamic internal representation of the external world. Underlying this feat in part is the brain's ability to rapidly detect temporal patterns over timescales that span orders of magnitude, from sub-milliseconds to tens of seconds. Of particular interest is the ability to detect rhythms, or sound patterns in the range of hundreds of milliseconds to seconds. This timescale is particularly fascinating because it is critical to the perception of rhythm and beat in music, an ability that comes surprisingly naturally to us despite its neural underpinnings being far from understood. It is not just musical beat perception that remains mysterious; even the brain's mechanisms for detecting simple temporal patterns at this timescale are still not known. The work in this thesis therefore explores two broad questions that are key to understanding temporal processing at the rhythm timescale: 1- what are the perceptual consequences of rhythmic temporal regularity in sound? and 2- how does the brain detect temporal regularities at the rhythm timescale? I combine human psychoacoustics, rodent electrophysiology, and computational modelling to demonstrate that rhythmic sound patterns are easier to detect than arrhythmic ones, that adaptation in the auditory system may be a mechanism by which information about temporal structure at the rhythm timescale is encoded and made available to higher structures, and that low-level auditory processing may play a substantial part in shaping complex percepts such as where and how clearly we feel the beat in music.</p

Temporal regularity in audition

Sound, by its very nature, is a temporal phenomenon. Everything from the perception of pitch to the sense of closure at the end of a symphony, relies on the brain's ability to integrate information over time. Ultimately it is perception that enables the richness of our interactions with the world around us, and it is a remarkable feat that the brain can quickly and accurately sift through the flood of information entering the ears to construct a coherent yet dynamic internal representation of the external world. Underlying this feat in part is the brain's ability to rapidly detect temporal patterns over timescales that span orders of magnitude, from sub-milliseconds to tens of seconds. Of particular interest is the ability to detect rhythms, or sound patterns in the range of hundreds of milliseconds to seconds. This timescale is particularly fascinating because it is critical to the perception of rhythm and beat in music, an ability that comes surprisingly naturally to us despite its neural underpinnings being far from understood. It is not just musical beat perception that remains mysterious; even the brain's mechanisms for detecting simple temporal patterns at this timescale are still not known. The work in this thesis therefore explores two broad questions that are key to understanding temporal processing at the rhythm timescale: 1- what are the perceptual consequences of rhythmic temporal regularity in sound? and 2- how does the brain detect temporal regularities at the rhythm timescale? I combine human psychoacoustics, rodent electrophysiology, and computational modelling to demonstrate that rhythmic sound patterns are easier to detect than arrhythmic ones, that adaptation in the auditory system may be a mechanism by which information about temporal structure at the rhythm timescale is encoded and made available to higher structures, and that low-level auditory processing may play a substantial part in shaping complex percepts such as where and how clearly we feel the beat in music.</p

Novel solid hypergolic fuels for hybrid propellants

A new class of compounds, viz., monothiocarbohydrazones, have been found to be hypergolic with anhydrous and red fuming nitric acids. A study of the ignition delays of the various thiocarbohydrazonenitric acid systems as a function of particle size and fuel/oxidizer ratio reveals no significant effect by these parameters. The observed ignition delays have been explained in terms of the chemical reactivity and structure of these compounds

Omission responses in local field potentials in rat auditory cortex

Abstract Background Non-invasive recordings of gross neural activity in humans often show responses to omitted stimuli in steady trains of identical stimuli. This has been taken as evidence for the neural coding of prediction or prediction error. However, evidence for such omission responses from invasive recordings of cellular-scale responses in animal models is scarce. Here, we sought to characterise omission responses using extracellular recordings in the auditory cortex of anaesthetised rats. We profiled omission responses across local field potentials (LFP), analogue multiunit activity (AMUA), and single/multi-unit spiking activity, using stimuli that were fixed-rate trains of acoustic noise bursts where 5% of bursts were randomly omitted. Results Significant omission responses were observed in LFP and AMUA signals, but not in spiking activity. These omission responses had a lower amplitude and longer latency than burst-evoked sensory responses, and omission response amplitude increased as a function of the number of preceding bursts. Conclusions Together, our findings show that omission responses are most robustly observed in LFP and AMUA signals (relative to spiking activity). This has implications for models of cortical processing that require many neurons to encode prediction errors in their spike output

Performance Analysis of Full Duplex Bidirectional Machine Type Communication System Using IRS with Discrete Phase Shifter

In this paper, passive Intelligent Reflecting Surface (IRS) is used to enhance the performance of a Full Duplex (FD) bidirectional Machine Type Communication (MTC) system with two source nodes. Each node is equipped with two antennas to operate in FD mode. In reality, self-interference and discrete phase shifting are two major impairments in FD and IRS-assisted communication, respectively. The self-interference at source nodes operating in FD mode is mitigated by increasing the number of meta-surface elements at the IRS. Bit Error Rate (BER) and outage performances are analyzed with continuous phase shifting and discrete phase shifting in IRS. Closed-form analytical expressions are derived for the outage probability and BER performances of the IRS-assisted bidirectional FD-MTC system with a continuous phase shifter. The outage and BER performances of the IRS-assisted bidirectional MTC system in the FD mode have Signal-to-Noise Ratio (SNR) improvement compared with the IRS-assisted bidirectional MTC system in Half Duplex (HD) mode, as the number of reflecting elements in IRS is doubled in the FD mode. The outage and BER performances are degraded by a discrete phase shifter. Hence, performance degradation of the proposed IRS-assisted bidirectional FD-MTC is examined for 1-bit shifter (0, π), 2-bit shifter (0, π/2, π, 3π/2), and for 3-bit shifter (0, π/4, π/2, 3π/4, π, 5π/4, 3π/2, 7π/4). The performance degradation when a discrete phase shifter is employed in IRS is compared with the ideal continuous phase shifter in IRS. Further, achievable rate analysis is carried out for finding the best location of the IRS in a bidirectional FD-MTC system

Data from: Midbrain adaptation may set the stage for the perception of musical beat

The ability to spontaneously feel a beat in music is a phenomenon widely believed to be unique to humans. Though beat perception involves the coordinated engagement of sensory, motor, and cognitive processes in humans, the contribution of low-level auditory processing to the activation of these networks in a beat-specific manner is poorly understood. Here, we present evidence from a rodent model that midbrain pre-processing of sounds may already be shaping where the beat is ultimately felt. For the tested set of musical rhythms, on-beat sounds on average evoked higher firing rates than off-beat sounds, and this difference was a defining feature of the set of beat interpretations most commonly perceived by human listeners over others. Basic firing rate adaptation provided a sufficient explanation for these results. Our findings suggest that midbrain adaptation, by encoding the temporal context of sounds, creates points of neural emphasis that may influence the perceptual emergence of a beat

Stimuli + gerbil electrophysiology and human tapping data

This .zip file contains spike PSTH and LFP data from the gerbil IC and human tapping data in Matlab format. Audio files of the stimuli are also included. See README for full details