Length Modulation Research Articles

On a question of Buchweitz about ranks of syzygies of modules of finite length

Let R be a local ring of dimension d. Buchweitz asks if the rank of the d-th syzygy of a module of finite lengh is greater than or equal to the rank of the d-th syzygy of the residue field, unless the module has finite projective dimension. Assuming that R is Gorenstein, we prove that if the question is affrmative, then R is a hypersurface. If moreover R has dimension two, then we show that the converse also holds true.

中央凹加工负荷与副中央凹信息在汉语阅读眼跳目标选择中的作用

<p id="C2">In alphabetic languages, such as English, the spaces between words are one kind of cue of visual word segmentation that guides the reader in selecting the word center as the saccadic target. Previous studies have shown that in English reading, such visual word boundaries can be extracted from parafoveal vision. However, no visual word boundary serves as a saccadic target for selection in Chinese reading. Most recently, several researchers have claimed that Chinese readers adjust their saccade length to accommodate lexical processing, rather than moving their eyes to specific saccadic targets. The properties of fixated words affect the subsequent saccadic target selection. For example, the saccade length is longer for high- than for low-frequency words. Moreover, parafoveal processing also has an important influence on the modulation of saccade length. Some researchers have nonetheless found that the load of fixated word processing modulates the processing of parafoveal words, where readers then adjust the selection of the next saccade target, though several studies have failed to find an interaction between the fixated word and foveal and parafoveal processing <p id="C2-1">Given the evidence that the frequency of fixated words and the strokes of parafoveal words significantly influence the upcoming saccade length, in the present study, the frequency of fixated words in foveal processing and the strokes of parafoveal words were manipulated to explore the relationship between foveal processing and parafoveal processing on saccade target selection. If the load of processing of fixated words modulates the processing of the word in parafoveal vision, then we predicted that the effect of parafoveal word strokes from adjusting the current saccade length would be more pronounced when the fixated word is processed in high- rather than in low-frequency foveal processing <p id="C2-3">The results showed that participants fixated on low-frequency words for a significantly longer time than for high-frequency words; they fixated on parafoveal words with a low number of strokes for a significantly shorter time than those with a high number of strokes; the saccade length of high-frequency words was longer than that of low-frequency words; the upcoming saccade length in parafoveal vision was significantly longer for words with a low than a high number of strokes; and the location of the initial fixation on words with a low number of strokes was closer to the word centre than with words with a high number of strokes. Unfortunately, we failed to observe significant interactions between these two factors for any eye movement measures used in the present study <p id="C2-4">The results indicate that the frequency of fixated word and the number of strokes of parafoveal words independently affect the selection of saccadic targeting in Chinese reading.

Controlling Droplet Motion on an Organogel Surface by Tuning the Chain Length of DNA and Its Biosensing Application

Summary Controllable droplet motion has attracted extensive attention but still faces the challenges of an uncontrollable sliding speed and a slow response rate. Here, controllable sliding speed and critical sliding angle (CSA) of a droplet on an oil-swollen organogel surface are achieved with a fast response rate via modulation of the DNA chain length. Comprehensive investigations ranging from macroscopic wetting behavior to molecular mechanism suggest that short single-stranded DNA (ssDNA) could act as a hydrotrope to interact with oil molecules via interfacial hydrophobic interactions while increasing the interfacial thickness and adhesion, thus hindering the movement of droplets. Conversely, long ssDNA generated from rolling-circle amplification tend toward a curled conformation, minimizing nucleobase exposure and leading to weak interfacial adhesion, allowing the droplets to slide easily. With a significant CSA gradient, biosensing applications for ATP, microRNA, and thrombin detection are demonstrated, indicating the potential for the detection of a broad range of targets.

Graphene aperture-based metalens for dynamic focusing of terahertz waves.

We theoretically study a tunable reflective focusing lens, based on graphene metasurface, which consists of rectangle aperture array. Dynamic control of either the focal intensity or focal length for terahertz circular polarized waves can be achieved by uniformly tuning the graphene Fermi energy. We demonstrate the graphene apertures with the same geometry; however, spatially varying orientations can only control the focal intensity. To change the focal length, the spatially varying aperture lengths are also required. A comparative study between the metalenses, which generate only geometric or both gradient and geometric phase changes, has shown that the apertures' spatially varying length distribution is the key factor for determining the modulation level, rather than the focal length's modulation range. This kind of metalens provides tunable, high-efficiency, broadband, and wide-angle off-axis focusing, thereby offering great application potential in lightweight and integrated terahertz devices.

Noncommutative resolutions using syzygies

Given a noether algebra with a noncommutative resolution, a general construction of new noncommutative resolutions is given. As an application, it is proved that any finite length module over a regular local or polynomial ring gives rise, via suitable syzygies, to a noncommutative resolution.

Neural Control of Balance During Walking.

Neural control of standing balance has been extensively studied. However, most falls occur during walking rather than standing, and findings from standing balance research do not necessarily carry over to walking. This is primarily due to the constraints of the gait cycle: Body configuration changes dramatically over the gait cycle, necessitating different responses as this configuration changes. Notably, certain responses can only be initiated at specific points in the gait cycle, leading to onset times ranging from 350 to 600 ms, much longer than what is observed during standing (50–200 ms). Here, we investigated the neural control of upright balance during walking. Specifically, how the brain transforms sensory information related to upright balance into corrective motor responses. We used visual disturbances of 20 healthy young subjects walking in a virtual reality cave to induce the perception of a fall to the side and analyzed the muscular responses, changes in ground reaction forces and body kinematics. Our results showed changes in swing leg foot placement and stance leg ankle roll that accelerate the body in the direction opposite of the visually induced fall stimulus, consistent with previous results. Surprisingly, ankle musculature activity changed rapidly in response to the stimulus, suggesting the presence of a direct reflexive pathway from the visual system to the spinal cord, similar to the vestibulospinal pathway. We also observed systematic modulation of the ankle push-off, indicating the discovery of a previously unobserved balance mechanism. Such modulation has implications not only for balance but plays a role in modulation of step width and length as well as cadence. These results indicated a temporally-coordinated series of balance responses over the gait cycle that insures flexible control of upright balance during walking.

Ultralow-power dielectric-modulated nanogap-embedded sub-20-nm TGRC-MOSFET for biosensing applications

This work examines a transparent gate recessed channel (TGRC) metal–oxide–semiconductor field-effect transistor (MOSFET) for biosensing, including a nanogap cavity for detection of biomolecules and a transparent gate to enhance the overall current efficiency of the RC-MOSFET. For the detection of neutral biomolecules, electrical characteristics such as ION/IOFF, shift in threshold voltage and change in surface potential have been studied and thereafter, sensitivity of has been evaluated. The biosensor showed enhanced sensitivity for biomolecules with increase in their dielectric value, due to greater on-current owing to the change in capacitances. The capacitances were therefore also evaluated. In addition, immobilization of biomolecules degrades the noise immunity of MOSFET and thereby their overall biosensing performance, while the noise immunity of the TGRC device was very high even in the presence of biomolecules. Furthermore, modulation of the cavity gap length was also investigated, revealing that its increase (from 8 to 20 nm) significantly enhanced the sensitivity of the proposed biosensor. Overall, the results of this analysis reveal that such TGRC-MOSFET biosensors can exhibit high sensitivity (1.45) at very low drain bias (0.2 V), enabling their use for biosensor applications to diagnose various diseases which require lower noise, high speed, low power, and high density.

DIBL–Compensated Extraction of the Channel Length Modulation Coefficient in MOSFETs

In this brief, a new channel length modulation (CLM) extraction method is proposed. The main innovation of this approach is that the extracted value of CLM is not artificially inflated by the contribution of the drain-induced barrier lowering (DIBL), which allows discriminating between the two phenomena. In this method, the transistor gain is measured by using the source-measurement unit in a forced current mode. It is demonstrated that the CLM coefficient can be extracted by the linear regression of the inverse of the gain with respect to the current-over-transconductance ratio, corrected for series resistances. This method is later applied and validated on a planar bulk 65-nm CMOS technology.

Trap Profiling an In-Ga-Zn-O Thin Film Transistor by Using a Transmission Line Model Incorporating the Conductance Method

The trap energy profile of top gate In-Ga-Zn-O (IGZO) thin film transistors was extracted successfully using a transmission line model incorporating the conductance method. By implementing the transmission line model method into the conventional conductance method, we were able to evaluate the contact resistance and the channel length modulation precisely and to decouple them to obtain the intrinsic channel conductance. The observed conductance over the angular frequency was almost perfectly symmetrical, which is observed only in the ideal conductance method. Finally, a shallow trap profile, including the trap density and time constant near the conduction band edge of IGZO, was extracted successfully.

All-fiber, thermo-optic liquid level sensor.

This paper proposes an all-optical-fiber sensor for continuous measurements of liquid levels. The proposed sensor utilizes an optically absorbing vanadium doped optical fiber, which is configured as a long-gauge, optically-heated, fiber-optic, Fabry-Perot interferometer that is immersed into the measured liquid. The sensor is excited cyclically by a medium-power 980 nm optical source, which induces periodic temperature variation and, consequently, optical path length modulation within the vanadium doped fiber. The amplitude of this path length variation depends on the liquid level and is measured by an interferometric approach. The relation between the liquid level and the amplitude of optical path length modulation caused by the fiber's temperature variation were investigated analytically, and the theoretical model proved to be in good agreement with the experimental results. Two versions of level sensors are demonstrated experimentally, the first with single-side optical heating power delivery and 0.45 m measurement range, and the second with dual-side power delivery and 1 m of operational measurement span. Experimental measurement level resolutions achieved for 0.45 m and 1m operational measurement span were approximately 2 and 3 mm, respectively. The simple and efficient design of sensor and signal interrogation system, the latter is based solely on a few widely available telecom components, provides straightforward opportunities for use of the proposed system in a variety of industrial applications.

Genome-wide measurement of local nucleosome array regularity and spacing by nanopore sequencing.

The nature of chromatin as regular succession of nucleosomes has gained iconic status. However, since most nucleosomes in metazoans are poorly positioned it is unknown to which extent bulk genomic nucleosome repeat length reflects the regularity and spacing of nucleosome arrays at individual loci. We describe a new approach to map nucleosome array regularity and spacing through sequencing oligonucleosome-derived DNA by Illumina sequencing and emergent nanopore technology. In Drosophila cells, this revealed modulation of array regularity and nucleosome repeat length depending on functional chromatin states independently of nucleosome positioning and even in unmappable regions. We also found that nucleosome arrays downstream of silent promoters are considerably more regular than those downstream of highly expressed ones, despite more extensive nucleosome phasing of the latter. Our approach is generally applicable and provides an important parameter of chromatin organization that so far had been missing.

Controlled Synthesis of Carbon Nanospheres via the Modulation of the Hydrophilic Length of the Assembled Surfactant Micelles.

A co-polymerization-carbonization method was employed to synthesize porous carbon nanospheres (PCNSs) using pyrrole-aniline polymers as a carbon source and alkyl phenol non-ionic surfactants as templates. The effect of the hydrophilic length on the carbon nanosphere size was systematically investigated. The so-prepared PCNSs were characterized via high-magnification scanning electron microscopy, dynamic light scattering (DLS) analysis, and N2 adsorption and desorption analysis. The results indicate that the obtained nanosphere diameter can be tuned by changing the length of the hydrophilic groups. The length of the hydrophilic groups mainly affects the size of the vesicles or micelles formed by the assembly of the surfactant in solution, as was verified by the DLS results. After activation by KOH, the typical sample EO(30)-PCNS has a high specific surface area of 2137 m2/g and a large pore volume of 1.76 cm3/g. Electrochemical tests in 6 M KOH demonstrated that the assembled EO(30)-PCNS supercapacitor electrode displays good capacitive properties, such as a high specific capacitance of 221 F/g at 1.0 A/g and a good rate capacity of 68% retention at 10.0 A/g. This finding suggests that the uniform particle shape and high specific surface area are beneficial for the ion transportation, leading to good electrochemical performances. Our work provides a novel synthetic strategy for the fabrication of carbon nanospheres or other nanosphere materials for the construction of high-performance supercapacitors by optimizing few parameters, such as the length of the hydrophilic or hydrophobic groups of the surfactants.

An Improved Large Signal Model for 0.1 μm AlGaN/GaN High Electron Mobility Transistors (HEMTs) Process and Its Applications in Practical Monolithic Microwave Integrated Circuit (MMIC) Design in W band.

An improved empirical large signal model for 0.1 µm AlGaN/GaN high electron mobility transistor (HEMT) process is proposed in this paper. The short channel effect including the drain induced barrier lowering (DIBL) effect and channel length modulation has been considered for the accurate description of DC characteristics. In-house AlGaN/GaN HEMTs with a gate-length of 0.1 μm and different dimensions have been employed to validate the accuracy of the large signal model. Good agreement has been achieved between the simulated and measured S parameters, I-V characteristics and large signal performance at 28 GHz. Furthermore, a monolithic microwave integrated circuit (MMIC) power amplifier from 92 GHz to 96 GHz has been designed for validation of the proposed model. Results show that the improved large signal model can be used up to W band.

An INS/Floor-Plan Indoor Localization System Using the Firefly Particle Filter

Location-based services for smartphones are becoming more and more popular. The core of location-based services is how to estimate a user’s location. An INS/floor-plan indoor localization system, using the Firefly Particle Filter (FPF), is proposed to estimate a user’s location. INS includes an attitude angle module, a step length module and a step counting module. In the step length module, we propose a hybrid step length model. The proposed step length algorithm reasonably calculates a user’s step length. Because of sensor deviation, non-orthogonality and the user’s jitter, the main bottleneck for INS is that the error grows over time. To reduce the cumulative error, we design cascade filters including the Kalman Filter (KF) and FPF. To a certain extent, KF reduces velocity error and heading drift. On the other hand, the firefly algorithm is used to solve the particle impoverishment problem. Considering that a user may not cross an obstacle, the proposed particle filter is proposed to improve positioning performance. Results show that the average positioning error in walking experiments is 2.14 m.

Multiplication Formulas and Canonical Bases for Quantum Affine gln

AbstractWe will give a representation-theoretic proof for the multiplication formula in the Ringel-Hall algebra of a cyclic quiver Δ(n). As a first application, we see immediately the existence of Hall polynomials for cyclic quivers, a fact established by J. Y. Guo and C. M. Ringel, and derive a recursive formula to compute them. We will further use the formula and the construction of a monomial basis for given by Deng, Du, and Xiao together with the double Ringel-Hall algebra realisation of the quantum loop algebra given by Deng, Du, and Fu to develop some algorithms and to compute the canonical basis for . As examples, we will show explicitly the part of the canonical basis associated with modules of Lowey length at most 2 for the quantum group .

A 2D Empirical Model for On-State Operation of Scaled IGZO TFTs Exemplifying the Physical Response of TCAD Simulation

The existence of band-tail states (BTS) in indium-gallium-zinc oxide (IGZO) results in TFTs with electrical characteristics that are not well represented by conventional device models. Common parameters such as threshold voltage and channel mobility that are extracted from measured electrical characteristics can be misrepresentative due to discrepancies between the chosen operational model and the underlying device physics. There have been several reports of analytical solutions for the electrostatic operation of IGZO transistors that have been motivated by model accuracy and efficiency in circuit simulation. While developed compact models may be physics based, the addition of fitting parameters to exceedingly complex solutions results in a loss of physical connection and limits the applications to circuit design. Similarly fitting parameters can be added to conventional SPICE models used by device researchers; however the modifications will only have merit if the physical connection to device operation is maintained. This is especially important as channel lengths are scaled and device structures exhibit short channel effects (SCE). A device model for the on-state operation of accumulation-mode IGZO TFTs which maintains consistency with the gradual channel approximation was recently developed and presented as an adaptation of a Level 2 SPICE model. The model accounts for the ionization and deionization of acceptor-like BTS, as controlled by both the gate and drain bias conditions. Long-channel TFT I-V characteristics are well represented by the physical channel length and width along with five operational parameters shown in equations (1-4). The model fit for a representative long-channel device is virtually indistinguishable from measured data, as shown in Fig. 1. The threshold voltage (VT) and field-independent channel mobility (μo) have traditional meaning, whereas the introduced BTS parameters (θBTS, VBTS, α) regulate the level of free channel charge and account for spreading of the output conductance. Model parameters were extracted using regression analysis on output characteristics with fine gate voltage increments. Parameter values for the representative device are shown in Table 1, with the resulting threshold voltage and channel mobility values consistent with TCAD analogs. The ηG and ηD model elements preserve the distinction between the gate-impressed and drain-impressed response, respectively, with dissociation from an effective channel mobility. This distinction is important to avoid confounding with SCE as devices are scaled and E-fields are increased. This work extends the device model to represent long-channel and scaled devices (i.e. L ≤ 3 μm) with bottom-gate (BG) and double-gate (DG) electrode configurations. BG and DG TFTs have different levels of gate control and influence over BTS, which becomes more pronounced as the channel length is decreased. For scaled devices, channel length modulation as well as conventional field-effect mobility parameters that account for normal-field degradation and velocity saturation have been added. TCAD simulation is used to discriminate between the influence of BTS and SCE. The physical correlation of the model to device operation is demonstrated through comparisons with measured characteristics and TCAD simulation. Figure 1

Analytical computation of electrical parameters in GAAQWT and CNTFET with identical configuration using NEGF method

ABSTRACTA two-dimensional quantum mechanical model is presented for calculating carrier transport in ultra-thin gate-all-around quantum wire transistor (GAAQWT) and carbon nanotube field effect transistor (CNTFET) using coupled mode space approach. Schrödinger and Poisson’s equations are self-consistently solved involving Non-Equilibrium Green’s Function (NEGF) formalism under the ballistic limit along with dissipative effects in terms of self-energy at both the source and drain ends. Effect of structural parameters on drain current, channel length modulation parameter, quantum capacitance, transconductance, subthreshold swing (SS) and drain induced barrier lowering (DIBL) are studied assuming occupancy of only a few lower sub-bands, where comparison is performed taking all other factors, biases and dimensions identical. High-k dielectric (HfO2) independently surrounding the quantum wire (GaAs) and carbon nanotube shows higher drain current and transconductance for GAAQWT but lower quantum capacitance than that obtained for CNTFET. A smaller variation of CLM for CNFET speaks in favour of it for digital quantum circuit applications, whereas GAAQWT is suitable candidate for low-power applications. Effect of structural parameters is investigated within fabrication limit to analyse the effect on electrical characteristics under lower biasing ranges.

Distributed Unique-Size MOS Technique: A Promising Universal Approach Capable of Resolving Circuit Design Bottlenecks of Modern Era

In this paper, a new universal technique based on the unique-size MOS transistors is proposed to resolve the analog circuit design bottlenecks imposed by nowadays modern technology downscaling. The method called here “distributed MOS (DMOS) technique” not only permits utilizing minimum-size transistors for analog circuit design, but also paves the way to emerging new generation of modern circuits and systems. It is proved that employing the proposed technique helps the optimum performance of the circuit to be preserved, regardless of minimum-size MOS transistors’ narrow channel effect and channel length modulation. This capability is anticipated to be logically maintained for even smaller transistors offered by future technology. The threshold and early voltage variations versus the MOS transistor channel width and length are investigated by numerical analysis of the data achieved from TSMC library for 180-nm technology using Cadence software, and the result uncertainty ascribed to them exhibited an excellent agreement with the initially developed extended MOS model. Higher linearity with lower THD is interestingly achieved for the new approach. The excellent conformity among the simulation and post-layout results verified the efficiency of the proposed design technique in practical circumstances.

Chains of semidualizing modules

Let [Formula: see text] be a commutative Noetherian local ring. We study the suitable chains of semidualizing [Formula: see text]-modules. We prove that when [Formula: see text] is Artinian, the existence of a suitable chain of semidualizing modules of length [Formula: see text] implies that the Poincar[Formula: see text] series of [Formula: see text] and the Bass series of [Formula: see text] have very specific forms. Also, in this case, we show that the Bass numbers of [Formula: see text] are strictly increasing. This gives an insight into the question of Huneke about the Bass numbers of [Formula: see text].

Reading Derived Words by Italian Children With and Without Dyslexia: The Effect of Root Length.

Children with dyslexia are extremely slow at reading long words but they are faster with stimuli composed of roots and derivational suffixes (e.g., CASSIERE, ‘cashier’) than stimuli not decomposable in morphemes (e.g., CAMMELLO, ‘camel’). The present study assessed whether root length modulates children’s morphological processing. For typically developing readers, root activation was expected to be higher for longer than shorter roots because longer roots are more informative access units than shorter ones. By contrast, readers with dyslexia were not expected to be facilitated by longer roots because these roots might exceed dyslexics’ processing capacities. Two groups of Italian 6th graders, with and without dyslexia, read aloud low-frequency derived words, with familiar roots and suffixes. Word reaction times (RTs) and mispronunciations were recorded. Linear mixed-effects regression analyses on RTs showed the inhibitory effect of word length and the facilitating effect of root frequency for both children with and without dyslexia. Root length predicted RTs of typically developing readers only, with faster RTs for longer roots, over and above the inhibitory effect of word length. Furthermore, typically developing children had faster RTs on words with more frequent suffixes while children with dyslexia were faster when roots had a small family size. Generalized linear regression analyses on accuracy showed facilitating effects of word frequency and suffix frequency, for both groups. The large word length effect on latencies confirmed laborious whole-word processing in children when reading low-frequency derived words. The absence of a word frequency effect along with the facilitating effect of root frequency indicated morphemic processing in all readers. The reversed root length effect in typically developing readers pointed to a stronger activation for longer roots in keeping with the idea that these represent particularly informative units for word decoding. For readers with dyslexia the facilitating effect of root frequency (not modulated by root length) confirmed a pervasive benefit of root activation while the lack of root length modulation indicated that the longest roots were for them too large units to be processed within a single fixation.