Length Of Partition Research Articles

Applicability Analysis of New Type of Waterproof and Drainage Partition Theory for Tunnels

Based on the shortcomings of the existing anti-drainage partitioning methods, this paper proposes a new partitioning method with solutions to the shortcomings. Thoroughly waterproofing with a “Shi” type waterstop in the length of one section, partitioning drainage with a sump tank. According to the basic formula of Darcy’s law, the calculation formula of the partition length is derived. The calculation of the Yaoshan to Nandan Highway Layi tunnel is carried out. The recommended value of the partition length is given. The numerical simulation is used to verify the applicability of the partitioning method.

Transient Natural Convection in Partitioned Enclosures

Abstract In this paper, the natural convection flow in a cavity heated differentially with a partition placed in the middle of the hot wall is numerically simulated. The aspect ratio of the geometry, Prandtl number are fixed at 0.24, 6.64, respectively, for different partitions lengths; however the Rayleigh number values were ranging from 106 to 3.77 × 109 in order to observe the transition regime. The fluid flow and the heat transfer described in terms of continuity, linear momentum and energy equations were predicted by using the finite volume method. To approach the physical reality experience, calculations were performed in a cavity with the same size and same priority of the fluid with an average temperature T m imposed on the cooled wall, also another simulation with an average temperature T m imposed on the horizontal wall. Time evolution, isotherms and mean Nusselt number are presented for all investigated values. Representative results illustrating the effects of the partition length for the heat transfer and the thermal boundary layer are also reported and discussed. The results indicate that the flow and heat transfer properties are altered by the presence of the partition, especially in the initial stage. In a certain sense, the partition blocks the flow and forces it to come off the hot wall. Since the partition parameters are critical for the transient natural convection flow in the cavity, different partition lengths on the warm wall have been studied.

Conjugate natural convection in a fluid‐saturated porous enclosure with two solid vertical partitions

AbstractConjugate natural convection in a fluid‐saturated square porous enclosure with two solid vertical partitions of finite and equal thickness equispaced from center of enclosure is investigated in this paper. The primary objective is to attenuate the Nusselt number (Nu) and hence the heat transfer rate across a differentially heated enclosure. Darcy's model is considered. Numerical computation is performed using successive accelerated replacement and explicit scheme. Partition ratio, partition length, thermal conductivity ratio, and modified Rayleigh number are the parameters under study. Fluid flow is analyzed by observing transient changes of streamlines and isotherms for partition length 0.3‐1, thermal conductivity ratio 0.5‐2, partition ratio 0.1‐0.3 and modified Rayleigh number 100 and 1000 where partition ratio is the ratio of distance between center of enclosure and either of the partition center to the total length of the enclosure; while Nusselt number is calculated to estimate the heat transfer rate for each configuration. It is found that, employing a solid partition within the enclosure most definitely reduces the Nusselt number. The drop in Nusselt number is more for partition length 0‐0.6 after which it does show a drop in Nu but only very subtle. Further, Nu is the least for partition ratio 0.2. Also, Nusselt number is proportional to thermal conductivity ratio which is the ratio of thermal conductivity of solid to porous medium.

RF-pilot-based partition phase correction for CO-OFDM system phase noise mitigation

A low-complexity optical phase noise mitigation scheme, based on a radio frequency pilot (RFP) and partition phase correction (PPC), is proposed. For diverse channel configurations, an optimized RFP with fixed parameters is first employed in coarse phase tracking for generality purposes. Based on the reliable predecision results, we propose a noniterative PPC algorithm to further suppress the residual noise. Numerical simulations demonstrate that compared with other phase noise compensation algorithms, the proposed scheme has better robustness and lower computational complexity. In addition, the performance degradation caused by decision errors is also discussed, and a moderate partition length with small floating range can guarantee satisfactory correction quality.

Experimental Investigation of Deterministic and Random Cyclic Patterns in HCCI Engine using Symbol Sequence Approach

Homogeneous charge compression ignition (HCCI) combustion emerged as promising technology for automotive pollution reduction. One of the major challenges for commercial application of HCCI combustion engine is to control the combustion in different engine operating conditions. Characteristics of HCCI cyclic variations are required for efficient control of combustion phasing. Cyclic variability has both stochastic and deterministic components. In this study, cyclic variations of IMEP and combustion duration in a HCCI engine are analyzed using symbol sequence method. To analyze the cyclic variations, 1500 consecutive engine cycle data are logged and processed. Results reveal that there is deterministic component in cyclic variations, which could lead to effective control strategies. Results confirm that in symbol sequence method optimal combination of number of partition and sequence length is dependent on engine operating conditions and selected combustion parameters. It is also found that controller should have information about more than just immediate previous cycle for effective control of HCCI engine.

Turbulent Natural Convection in Partitioned Square Cavities with Different Lengths and Positions

The effect of partition on turbulent natural convection has been investigated numerically with different lengths and positions in an air filled square cavity. The top wall of the cavity is assumed to be cold and the other three walls are hot. Two-dimensional governing equations based on Reynolds-averaged Navier-Stokes equations are solved numerically by control volume method in a staggered grid manner. The iterative SIMPLE algorithm is also used to solve the discretized momentum equations to compute the intermediate velocity and pressure fields linked through the momentum equations. The hybrid differencing scheme which is based on a combination of central and upwind schemes is employed to discretize the convective and diffusion terms of the equations respectively. To describe the structure of turbulent flow which is changed due to the increasing importance of viscous effects, wall function was applied to simulate the turbulent flow. The results show that when the partition is placed on the top or bottom wall, the heat transfer rate through the bottom wall increases by increasing the partition length. The number of vortices established in the cavity depends on the partition length. Furthermore, when the partition is mounted on the left or right wall, only a small part of the top wall has a direct interaction with the left wall and the rest of that has an indirect interaction with the bottom wall.

Numerical Investigation Of transient Natural Convection In partitioned cavity filled with water

Transient natural convection in partitioned cavity filled with water is investigated numerically in this paper. The fluid flow and the heat transfer expressed in terms of continuity, linear momentum and energy equations were calculated by using the finite volume method.Prandtl number and Rayleigh number are fixed at 6.64 and 3,77x109, respectively, and the partition length of L/4. To approach the physical reality experience, calculations were performed in a cavity with the same size and same priority of the fluid with the temperature imposed on the cooled wall is equal to the average temperature Tm, also another calculations with the temperature imposed on the horizontal walls is equal to the average temperature Tm.The achieved results demonstrating the effects of the partition for the heat transfer and the thermal boundary layer are shown and discussed, it illustrate that the existence of the partition on the hot wall influences both heat transfer and fluid flow.

Superoptimal Perceptual Integration Suggests a Place-Based Representation of Pitch at High Frequencies.

Pitch, the perceptual correlate of sound repetition rate or frequency, plays an important role in speech perception, music perception, and listening in complex acoustic environments. Despite the perceptual importance of pitch, the neural mechanisms that underlie it remain poorly understood. Although cortical regions responsive to pitch have been identified, little is known about how pitch information is extracted from the inner ear itself. The two primary theories of peripheral pitch coding involve stimulus-driven spike timing, or phase locking, in the auditory nerve (time code), and the spatial distribution of responses along the length of the cochlear partition (place code). To rule out the use of timing information, we tested pitch discrimination of very high-frequency tones (>8 kHz), well beyond the putative limit of phase locking. We found that high-frequency pure-tone discrimination was poor, but when the tones were combined into a harmonic complex, a dramatic improvement in discrimination ability was observed that exceeded performance predicted by the optimal integration of peripheral information from each of the component frequencies. The results are consistent with the existence of pitch-sensitive neurons that rely only on place-based information from multiple harmonically related components. The results also provide evidence against the common assumption that poor high-frequency pure-tone pitch perception is the result of peripheral neural-coding constraints. The finding that place-based spectral coding is sufficient to elicit complex pitch at high frequencies has important implications for the design of future neural prostheses to restore hearing to deaf individuals.SIGNIFICANCE STATEMENT The question of how pitch is represented in the ear has been debated for over a century. Two competing theories involve timing information from neural spikes in the auditory nerve (time code) and the spatial distribution of neural activity along the length of the cochlear partition (place code). By using very high-frequency tones unlikely to be coded via time information, we discovered that information from the individual harmonics is combined so efficiently that performance exceeds theoretical predictions based on the optimal integration of information from each harmonic. The findings have important implications for the design of auditory prostheses because they suggest that enhanced spatial resolution alone may be sufficient to restore pitch via such implants.

Parallel Decodable Multi-Level Unequal Burst Error Correcting Codes for Memories of Approximate Systems

Processing at the nanometric scales presents unique challenges that may require new computational paradigms such as approximate computing. In this paper a novel approach to memory protection using an unequal protection code (UEP) is proposed; this approach is in synergy with approximate (or inexact) computing. Multi-level burst error correcting UEP codes are analyzed. These codes improve over previously presented two-level burst error correcting UEP codes, because they utilize different conditions and criteria in the code partitions and decoder construction. An analysis by which multiple partitions can be selected to reduce the expected error magnitude, is provided. The area and power consumption of the parallel decoders closely depend on the desired code function. Simulation shows that the area and power consumption of the parallel error pattern generator are proportional to the partition length; the gate depth however is not strongly related to the partition length. The results of this manuscript confirm that the proposed multi-level burst error correcting UEP codes reduce the hardware overhead with no significant degradation in storage protection as potential storage application for approximate computing systems.

On the Gaussian Pulse Propagation Through Multilayer Graphene Plasmonic Waveguides—Impact of Electrostatic Screening and Frequency Dispersion on Group Velocity and Pulse Distortion

In this paper, we analytically describe the characteristics of propagating and diffusive plasma waves in multilayer graphene heterostructures targeted toward implementing on-chip interconnects. When the effect of collision-dominated resistance of the graphene sheet is negligible, the plasma waves propagate through the media without pulse reshaping. However, in the presence of electron scatterings due to phonons and charged impurities in the sample, the plasma waves acquire a diffusive character and undergo significant frequency-dependent pulse reshaping. We analytically model the propagation speed and pulse-width distortion of a narrow-band Gaussian signal centered at THz frequencies by accounting for the finite electrostatic screening between the multiple layers of graphene. The consequences of signal distortion and attentuation on limiting the signal bit-rate and the impact on energy dissipation are quantified. A partition length of the plasmonic waveguide that distinguishes between $LC$ - and $RC$ -dominated regimes of signal transport is derived. For on-chip interconnect application, the upper bound on the propagation length of plasma waves is determined by both the energy dissipation and the bit-rate requirement of the interconnect infrastructure. Upon comparison with on-chip electrical interconnects, we identify the energy budget that can be allocated toward plasmonic transceivers, such that the overall plasmonic communication is more energy efficient compared to electrical communication.

Partitioning length of stay to understand readmission risk: survival analysis in the American College of Surgeons (ACS) NSQIP database

CONCLUSIONS: Implementation of a comprehensive ERP in major AWR was not associated with any adverse effects. Multimodal perioperative pain management, oral opioid receptor blockade and early feeding strategies resulted in accelerated intestinal recovery, shorter hospitalizations and fewer readmissions. The use of our ERP appears to result in improved outcomes in patients undergoing complex open AWRs.

Red:far-red light conditions affect the emission of volatile organic compounds from barley (Hordeum vulgare), leading to altered biomass allocation in neighbouring plants.

Volatile organic compounds (VOCs) play various roles in plant-plant interactions, and constitutively produced VOCs might act as a cue to sense neighbouring plants. Previous studies have shown that VOCs emitted from the barley (Hordeum vulgare) cultivar 'Alva' cause changes in biomass allocation in plants of the cultivar 'Kara'. Other studies have shown that shading and the low red:far-red (R:FR) conditions that prevail at high plant densities can reduce the quantity and alter the composition of the VOCs emitted by Arabidopsis thaliana, but whether this affects plant-plant signalling remains unknown. This study therefore examines the effects of far-red light enrichment on VOC emissions and plant-plant signalling between 'Alva' and 'Kara'. The proximity of neighbouring plants was mimicked by supplemental far-red light treatment of VOC emitter plants of barley grown in growth chambers. Volatiles emitted by 'Alva' under control and far-red light-enriched conditions were analysed using gas chromatography-mass spectrometry (GC-MS). 'Kara' plants were exposed to the VOC blend emitted by the 'Alva' plants that were subjected to either of the light treatments. Dry matter partitioning, leaf area, stem and total root length were determined for 'Kara' plants exposed to 'Alva' VOCs, and also for 'Alva' plants exposed to either control or far-red-enriched light treatments. Total VOC emissions by 'Alva' were reduced under low R:FR conditions compared with control light conditions, although individual volatile compounds were found to be either suppressed, induced or not affected by R:FR. The altered composition of the VOC blend emitted by 'Alva' plants exposed to low R:FR was found to affect carbon allocation in receiver plants of 'Kara'. The results indicate that changes in R:FR light conditions influence the emissions of VOCs in barley, and that these altered emissions affect VOC-mediated plant-plant interactions.

Automatic spline smoothing of non-stationary kinematic signals using bilayered partitioning and blending with correlation analysis

Measurement errors of kinematic signals introduced by motion capture systems are unacceptably amplified when differentiating the signal to derive acceleration. Existing fully automatic methods for solving this problem have a weakness on non-stationary signals involving impacts, while semi-automatic methods each require that users carefully determine the values of configurable parameters. We propose an automatic method that estimates acceleration from non-stationary kinematic signals using bilayered partitioning and blending (BPB) with correlation analysis. The method has a configurable parameter, the partition length, and the recommended value of the partition length that is empirically derived can be used without prior knowledge of kinematic signals. Having applied this algorithm to synthetic sinusoidal data, benchmarking data in the biomechanics community, and our own measurement data, we compared the results with those of existing automatic methods. The evaluation confirms that the proposed method estimates acceleration more accurately from non-stationary signals than existing fully automatic methods and is more robust than existing semi-automatic methods.

エルボ流路に配置された回転円柱を用いた粘性マイクロポンプの特性

The model experiment, the numerical calculation and the theoretical analysis are performed to investigate the characteristic of a viscous micropump by using a rotating cylinder in an elbow duct. In the experiment, the low Reynolds flow in the centimeter-scale micropump is realized by using glycerin as working fluid. The flow is visualized by an aluminum powder for Particle Image Velocimetry (PIV) analysis. In the theoretical analysis, the 2D lubrication theory is adopted and the pressure performance formula of the viscous micropump in the elbow duct is proposed. The performance curves derived from the formula agree well with the numerical results. Therefore, the proposed formula can be used for the design of the viscous micropump in the elbow duct. The performance curve, the φ-ΨRe curve, becomes a straight line with a negative slope. In the experimental and numerical results, the two vortices which rotate in the opposite direction of the rotating cylinder are observed. With an increase of the angle of the elbow duct, the pressure dimensionless number at the zero flow coefficient increases and the flow coefficient at the zero pressure coefficient slightly decreases. The pressure performance is degraded at the normalized partition lengths smaller than 0.05.

Numerical Study of a Solar Collector with Partitions

An optimization procedure integrating response surface methodology and genetic algorithm is proposed to design a solar collector with partitions. The heat transfer phenomena in a solar collector are numerically studied by investigating the influences of the dimensionless partition length (L), the dimensionless partition thickness (W), and the dimensionless partition pitch (A) in the collector. The results show that both the dimensionless partition length and the dimensionless partition pitch significantly affect the thermal performance while the dimensionless partition thickness only has a slight effect. The thermal enhancement from these optimized geometries (L, W, A) = (0.8, 0.1, 2) is 61% higher than those obtained in the literature.

Spin Hurwitz numbers and the Gromov-Witten invariants of Kähler surfaces

The classical Hurwitz numbers which count coverings of a complex curve have an analog when the curve is endowed with a theta characteristic. These “spin Hurwitz numbers”, recently studied by Eskin, Okounkov and Pandharipande, are interesting in their own right. By the authors’ previous work, they are also related to the Gromov-Witten invariants of Kahler surfaces. We prove a recursive formula for spin Hurwitz numbers, which then gives the dimension zero GW invariants of Kahler surfaces with positive geometric genus. The proof uses a degeneration of spin curves, an invariant defined by the spectral flow of certain anti-linear deformations of ∂, and an interesting localization phenomenon for eigenfunctions that shows that maps with even ramification points cancel in pairs. The Hurwitz numbers of a complex curveD count covers with specified ramification type. Specifically, consider degree d (possibly disconnected) covering maps f : C → D with fixed ramification points q, . . . , q ∈ D and ramification given by m, . . . ,m where each m = (m1, · · · ,mili) is a partition of d. The Euler characteristic of C is related to the genus h of D and the partition lengths l(m) = li by the Riemann-Hurwitz formula χ(C) = 2d(1− h) + k ∑ i=1 ( l(m)− d). (1.1) In this context, there is an ordinary Hurwitz number ∑ 1 |Aut(f)| (1.2) that counts the covers f satisfying (1.1) mod automorphisms; the sum depends only on h and {mi}. Now fix a theta characteristic N on D, that is, a holomorphic line bundle with an isomorphism N = KD whereKD is the canonical bundle of D. The pair (D,N) is called a spin curve. By a well-known theorem of Mumford and Atiyah, the deformation class of the spin curve is completely characterized by the genus h of D and the parity p = (−1)h0(D,N) (1.3) Now consider degree d ramified covers f : C → D for which • each partition m is odd, i.e. each mj is an odd number. (1.4) In this case, the ramification divisor Rf of f is even and the twisted pullback bundle Nf = f ∗N ⊗O ( 1 2Rf ) (1.5) ∗partially supported by N.S.F. grants DMS-1206192 (J.L.) and DMS-1011793 (T.P.)

Obtaining reliable phase-gradient delays from otoacoustic emission data

Reflection-source otoacoustic emission phase-gradient delays are widely used to obtain noninvasive estimates of cochlear function and properties, such as the sharpness of mechanical tuning and its variation along the length of the cochlear partition. Although different data-processing strategies are known to yield different delay estimates and trends, their relative reliability has not been established. This paper uses in silico experiments to evaluate six methods for extracting delay trends from reflection-source otoacoustic emissions (OAEs). The six methods include both previously published procedures (e.g., phase smoothing, energy-weighting, data exclusion based on signal-to-noise ratio) and novel strategies (e.g., peak-picking, all-pass factorization). Although some of the methods perform well (e.g., peak-picking), others introduce substantial bias (e.g., phase smoothing) and are not recommended. In addition, since standing waves caused by multiple internal reflection can complicate the interpretation and compromise the application of OAE delays, this paper develops and evaluates two promising signal-processing strategies, the first based on time-frequency filtering using the continuous wavelet transform and the second on cepstral analysis, for separating the direct emission from its subsequent reflections. Altogether, the results help to resolve previous disagreements about the frequency dependence of human OAE delays and the sharpness of cochlear tuning while providing useful analysis methods for future studies.

Passive mechanical properties of the gastrocnemius after spinal cord injury

In this study we compared passive mechanical properties of gastrocnemius muscle-tendon units, muscle fascicles, and tendons in control subjects and people with ankle contractures after spinal cord injury. Passive gastrocnemius length-tension curves were derived from passive ankle torque-angle data obtained from 20 spinal cord injured subjects with ankle contractures and 30 control subjects. Ultrasound images of muscle fascicles were used to partition length-tension curves into fascicular and tendinous components. Spinal cord injured subjects had stiffer gastrocnemius muscle-tendon units (stiffness index: 74.8 ± 27.0 m(-1) ) than control subjects (54.4 ± 17.7 m(-1) ) (P = 0.004). Muscle-tendon slack lengths, as well as slack lengths and changes in length of fascicles and tendons, were similar in the two groups. People with ankle contractures after spinal cord injury have stiff gastrocnemius muscle-tendon units. It is not clear whether this reflects changes in properties of muscle fascicles or tendons.

Impedance response and modeling of composites containing aligned semiconductor whiskers: Effects of dc-bias partitioning and percolated-cluster length, topology, and filler interfaces

Impedance spectroscopy and modeling were used to investigate the partitioning of 0-40 V dc bias in composites containing alumina and different volume fractions of silicon carbide whiskers (SiCw), which formed low-connectivity percolated clusters. Differences in response between long (∼25 cm) composite rods and thin (∼1.7 mm) slices thereof were interpreted in terms of the relative contributions to the impedance from the electrodes and SiCw-percolated clusters of the composite samples. Bias had minimal effect on the impedance of rods, because its distribution across the long percolated clusters within translated to low electric fields at the SiCw-SiCw interfaces. The impedance of thin slices was more sensitive to bias and was mainly due to such interfaces. The associated dc resistance and effective capacitance decreased significantly with increasing dc bias. A model for symmetrical Schottky energy barriers at interfaces fit the capacitance trend and outputted a parameter Φi/κ¯i. Different models for the non-linear current-voltage behavior were related to each other and indicated weak varistor-like behavior, i.e., 1.15 ≤ αV ≤ 2.57. With increasing SiCw content and composite dc conductivity, Φi/κ¯i increased and the varistor non-linearity strength αV decreased. Also, the exponent t describing conductivity divergence at percolation was reduced at large dc bias. A new model of percolated clusters was proposed and correctly predicted the qualitative character and some quantitative aspects of these experimental results. The model is based on tendencies of the current distribution, which are expected from the topological structure and contrast between interface/whisker electrical behavior. Accordingly, it outputs the voltage-distribution tendencies.

Transition Analysis for Power Reduction in SoC

Size and complexity have been major issues for System-on-a-Chip (SoC) testing. Transition analysis plays a significant role in power consideration of SoC testing. Transition is directly propositional to the power. This paper is based on finding transition calculation to achieve minimum power consideration. Transition study is applied for both specified and unspecified bits. The unspecified bits are specified by using X filling techniques like Zero filling and One filling algorithm. Transition analysis is considered for different partition length. The proposed method is successfully tested on ISCAS89 benchmark circuits which achieve minimum power consideration