Split Length Research Articles

Performance Diagnosis Tool for Arterial Traffic Signals

Efficient operation of traffic signals is greatly beneficial to drivers. Because of the intensive labor required, most traffic signals in the United States are retimed once every 3 to 5 years or more, even though signal retiming has a very high benefit–cost ratio. Such a practice may miss opportunities for operational improvements and lead to unnecessary delays. One of the major obstacles to improving the practice is the lack of data collection capability and a convenient performance monitoring tool for signalized arterials. To fill this gap, this paper proposes a performance diagnosis tool for arterial traffic signal systems. The tool aims at identifying necessary parameter changes and assisting agencies in periodically fine-tuning signal timing parameters. A flexible and low-cost data collection unit is developed to equip traffic signal cabinets with event-based data collection capability. Three major parameters of traffic signals (offset, green split, and cycle length) are evaluated in the data center by diagnosis modules that use event-based traffic data. The development of the data collection unit and the diagnosis methodologies are described in detail. The implementation of the tool is illustrated by field data analysis at intersections on Trunk Highway 13 in Burnsville, Minnesota.

Performance Diagnosis Tool for Arterial Traffic Signals

Efficient operation of traffic signals is greatly beneficial to drivers. Because of the intensive labor required, most traffic signals in the United States are retimed once every 3 to 5 years or more, even though signal retiming has a very high benefit–cost ratio. Such a practice may miss opportunities for operational improvements and lead to unnecessary delays. One of the major obstacles to improving the practice is the lack of data collection capability and a convenient performance monitoring tool for signalized arterials. To fill this gap, this paper proposes a performance diagnosis tool for arterial traffic signal systems. The tool aims at identifying necessary parameter changes and assisting agencies in periodically fine-tuning signal timing parameters. A flexible and low-cost data collection unit is developed to equip traffic signal cabinets with event-based data collection capability. Three major parameters of traffic signals (offset, green split, and cycle length) are evaluated in the data center by diagnosis modules that use event-based traffic data. The development of the data collection unit and the diagnosis methodologies are described in detail. The implementation of the tool is illustrated by field data analysis at intersections on Trunk Highway 13 in Burnsville, Minnesota.

Influência da classe diâmetrica nos índices de rachadura da madeira em Liquidambar styraciflua

The growth stresses of trees can be evaluated by means of the analysis of the end splitting on green and dry boards. Thus, this work aimed to study the evolution of the splitting length during the process of natural drying in the sawn wood of 24-year-old Liquidambar styraciflua, as a function of different diameter classes (upper, middle and lower) and two vertical positions along the stem commercial height. According to the results obtained, it was possible to conclude that the end splitting on green and dry boards was influenced only by the diameter class, where the upper class presented the greatest length of splitting while the lower class showed the smallest length. A strong relationship between the end splitting of dry board and green board was verified.

Split length FGMOS MOS cell: a new block for low voltage applications

A new analog cell, called floating gate split length MOSFET (FGSLM), has been presented. This cell is based on the popular self-cascode structure, and has been found suitable for use in low voltage design applications. The proposed cell has been characterized using 130 nm technology at supply voltage of 1.2 V. Simulation results are presented to demonstrate the utility of the proposed cell in low voltage self cascode structures.

破壊エネルギーを用いたクラックモデルの木材への適応性と破壊進行領域長さ

This paper describes the adaptability of Hillerborg fictitious crack model to timber. Using the regression line between the cumulative loss of the potential energy and the fictitious splitting length from the test data, the fracture process zone length was defined the length between the origin and x-intercept of the regression line, and the fracture energy was defined the slope of the regression line. The strength calculated by the fracture mechanical model on the specimen assuming initial splitting length equal to the fracture process zone length were agreement with the experimental results. However, the strength calculated by the fracture mechanical model using the conventional assuming initial splitting length equal to zero, was dangerously overestimated with the experimental results.

Some Physical Properties of Rice Kernels: Variety PR-106

The objective of this work was to determine some of the physical properties of PR-106 type of rice variety which may influence the rice processing operations. The physical properties Length or Longitudinal (L), Width (W), Thickness (T), Mass (M) and Volume (V) were measured at a moisture content of 13.34 ± 0.53% (dry basis) and the following results were obtained: the average split length, width, thickness, unit mass and volume were 6.61 mm, 1.75 mm, 1.40 mm, 0.017 g, and 0.051 cm3 respectively. The calculated physical properties like the geometric mean diameter, surface area, porosity, sphericity, true density and aspect ratio were 2.52 mm, 20.10 mm2, 47.07%, 38.28%, 1.521 g/ml and 26.58% respectively. The static coefficient of friction varied on three different surfaces from 0.217 on galvanized steel sheet, 0.239 on Plywood to 0.249 on glass with splits perpendicular to direction of motion, while the angle of repose was 34.86°.

A practical real-time non-uniform rational B-spline curve interpolator for computer numerical control machining

Non-uniform rational B-spline (NURBS) interpolator, a key technique in computer numerical control (CNC) machining, has many advantages over linear and circular interpolator. A practical real-time NURBS interpolator based on an off-line algorithm, which is developed to handle the limitation of velocity and acceleration, is presented in this article. Two processing modules are employed to realize the real-time interpolator. In one module, a NURBS curve is split into shorter NURBS curves or approximated as continuous line segments according to the minimum splitting length first, and then the velocity planning of a short curve is applied. Inthe other module, the interpolation according to the velocity planning results is implemented. The proposed algorithm realizes the real-time velocity planning and interpolation of a NURBS curve regardless of the curve length or the continuity. It is also applicable to three-dimensional surface designed by computer-aided design system, which is composed of multiple NURBS curves or both NURBS curves and continuous line segments. Both the simulation and experiment results have proved the effectiveness of the proposed practical real-time NURBS interpolator.

Polarization Splitting of Photonic Crystal Fiber With Hybrid Guidance Mechanisms

A polarization splitter is proposed in a photonic crystal fiber with hybrid guidance mechanisms, i.e., total internal reflection and antiresonant reflection. High extinction ratios are achieved in a compact structure over a wavelength range. Moreover, the operating wavelength, splitting length, and bandwidth can be controlled accurately through control of refractive index of the fiber. Our research offers a deep physical insight into the novel light transmission phenomenon and is useful for future applications of the device.

Traveling waves in two parallel infinite linear point-scatterer arrays

Traveling waves in two coupled parallel infinite linear point-scatterer arrays are studied analytically for the first time to our knowledge. The two arrays are considered to be generally offset in the axial direction. It is found that slow quasi-even/odd supermodes are supported, as a result of the coupling-induced splitting of the modes of the single array, in direct analogy to standard optical waveguide couplers. Exactly even/odd supermodes are supported when the axial offset is zero. Mode splitting, dispersion curves, and coupling length are numerically investigated versus the inter-element spacing, the inter-array distance, and the axial offset. Potential applications of the concept are in directional optical couplers made of metallic or dielectric nanoparticle chains.

Silicon-on-insulator polarization splitter using two horizontally slotted waveguides

We propose and analyze a short-length silicon-on-insulator polarization splitter using two horizontally slotted silicon waveguides. A polarization splitter with a 46.7 microm length and a 22 dB extinction ratio (ER) is achieved. Around 1550 nm, it also exhibits an 18 nm bandwidth for ER>20 dB. The effects of the slot thickness, the waveguide spacing, and the refractive index of the slot on the splitting length and ER are investigated.

Splitting length of abelian mixed groups of torsion-free rank 1

The splitting length of a mixed Abelian group G is defined as the smallest positive integer n such that \( \mathop \otimes \limits^n G \) splits. The task of determining the splitting length of mixed Abelian groups was formulated by Irwin, Khabbaz, and Rayna. In this paper, a criterion for determining whether \( \mathop \otimes \limits^n G \) splits for countable mixed Abelian groups G of torsion-free rank 1 is found.

Traffic Control Strategy for a Surface Street on an Expressway-Arterial Corridor

Off-ramp area congestion and off-ramp queue spill over are wide-spread reasons for expressway traffic jams in China. A control strategy was developed to reduce the number of collisions between expressway and surface street vehicles and to reduce spill over by controlling the surface street vehicles to improve the traffic conditions near expressway off-ramps. This control algorithm monitors the traffic conditions at the off-ramp using occupancy rates and a performance index for the surface street vehicles, and then optimizes the control signal split and cycle length for the surface street vehicles assuming that the off-ramp queue is shorter than the minimum allowable length. Simulations indicate improvements in the traffic flow with the average vehicle travel time nearly 10% less and the off-ramp queue reduced significantly.

Multimode interference splitter based on dielectric-loaded surface plasmon polariton waveguides

We numerically demonstrated 1 x N multimode interference (MMI) splitters based on dielectric-loaded surface plasmon polariton waveguides (DLSPPW). The dependences of real part of effective index, propagation length and lateral mode profiles of the waveguides on the geometrical parameters are analyzed in detail. The transmission efficiency of the MMI splitter is as much as 60%, with their splitting length being in the range of several micrometers. The performance of the device is found in agreement with results predicted by theoretical MMI self-imaging theory. Such MMI splitter is important for implementation of high density photonic integration and lab-on-a-chip applications.

Treatment of isolated posterior coronal fracture of the lateral tibial plateau through posterolateral approach for direct exposure and buttress plate fixation

To present a case series of patients with isolated posterior coronal fractures of lateral tibial plateau treated by direct exposure and buttress plate fixation through posterolateral approach. Between May 2007 and April of 2008, eight middle aged patients were identified that had isolated posterior coronal fractures of the lateral tibial plateau. All eight patients underwent direct fracture exposure, reduction under visualization, and buttress plate fixation through posterolateral approach. There were 1 case of split, two cases of pure depression and five cases of split-depression fractures. Four were associated fibular head split fractures without common peroneal nerve injuries. Five patients were injured from a simple fall on riding electrical bicycle while the knee was relaxed in 90 degrees position The articular displacement (8 cases) measured in CT scan was 10.5 mm in average (range 8-15 mm). The cortical split length (from the articular rim to the distal tip, 6 cases) was 2.8 cm in average (range 2.4-3.5 cm). The articular reduction was perfect in seven (absolutely no step-off) and imperfect in 1(<2 mm step-off) as measured by X-ray. With a mean follow-up of 10 months (6 cases > 12 months), the average range of motion arc was 119 degrees , four patients have flexion lag 10 degrees -20 degrees . The average SMFA dysfunction score was 15.8, and average HSS score was 98. All eight patients stated they were highly satisfied. Direct posterolateral approach by dividing lateral border of soleus muscle, provides excellent fracture reduction under visualization and internal buttress plate fixation for posterior coronal fracture of the lateral tibial plateau. Good functional results and recovery can be expected.

Effects of thickness of β-barium borate and angle of non-collinearity on the fs pulse generation by optical parametric amplification

Non-collinear optical parametric amplifiers (NOPAs) are used for the generation of tunable femtosecond pulses. The spectra of the uncompressed output from a lab-built NOPA in the 470–650 nm range have been recorded. Theoretical simulations for the effect of the length of the β-barium borate (BBO) crystal as well as the non-collinear angles between the pump and seed wavelengths have been carried out. For these we have obtained the initial experimental data from a 2 mm-thick BBO crystal when pumped with the second harmonic of the Ti:sapphire laser pulses of 100 fs duration. The pulse splitting length (PSL) and the group velocity mismatch (GVM) have been considered in simulations of the output. It was found that the crystal length of 1.3 mm and the crystal tilt of approximately 3.7° are optimal for the generation of pulses of ∼11 fs at 600 nm.

Ultracompact multiway beam splitters using multiple coupled photonic crystal waveguides

Ultracompact 1 × N (N > 2) beam splitters based on coupling of multiple photonic crystal waveguides (PCWs) are numerically demonstrated. The operation of the devices is on the basis of the self-imaging phenomenon. Variation of the effective index of modified rods induces the transverse redistribution of the N-fold images with the same coupling length, and uniform or free splitting can be achieved. The devices with three and four output channels are discussed in details as examples. Results show that this kind of beam splitters are very short. At the operating wavelength of 1.55 µm, the splitting length of the devices is only 35 µm even if the output channel number reaches 20. It provides a new method and a compact model to export freely the beam to N channels in PCW devices and can find practical applications in future photonic integrated circuits.

Stochastic analysis of shear-wave splitting length scales

The coherence of azimuthal seismic anisotropy, as inferred from shear-wave splitting measurements, decreases with the relative distance between stations. Stochastic models of a two-dimensional vector field defined by a von Karma'n [T. von Karma'n, Progress in the statistical theory of turbulence, J. Mar. Res., 7 (1948) 252–264.] autocorrelation function with horizontal correlation length L provide a useful means to evaluate this heterogeneity and coherence lengths. We use the compilation of SKS splitting measurements by Fouch [M. Fouch, Upper mantle anisotropy database, accessed in 06/2006, http://geophysics.asu.edu/anisotropy/upper/] and supplement it with additional studies, including automated measurements by Evans et al. [Evans, M.S., Kendall, J.-M., Willemann, R.J., 2006. Automated SKS splitting and upper-mantle anisotropy beneath Canadian seismic stations, Geophys. J. Int. 165, 931–942, Evans, M.S., Kendall, J.-M., Willemann, R.J. Automated splitting project database, Online at http://www.isc.ac.uk/SKS/, accessed 02/2006]. The correlation lengths of this dataset depend on the geologic setting in the continental regions: in young Phanerozoic orogens and magmatic zones L ∼ 600 km, smaller than the smooth L ∼ 1600 km patterns in tectonically more stable regions such as Phanerozoic platforms. Our interpretation is that the relatively large coherence underneath older crust reflects large-scale tectonic processes (e.g. continent–continent collisions) that are frozen into the tectosphere. In younger continental regions, smaller scale flow (e.g. slab anomaly induced) may predominantly affect anisotropy. In this view, remnant anisotropy is dominant in the old continents and deformation-induced anisotropy caused by recent asthenospheric flow is dominant in active continental regions and underneath oceanic plates. Auxiliary analysis of surface-wave anisotropy and combined mantle flow and anisotropic texture modeling is consistent with this suggestion. In continental regions, the further exploration of a stochastic description of seismic anisotropy may form a useful counterpart to deterministic forward modeling, particularly if we wish to understand the origin of discrepancies in heterogeneity estimates based on different seismological data sets.

Observed multiple frequencies of the Chandler wobble

Abstract Two time spans of up-to-date polar motion observations [Gross, R.S., 2005. Combinations of Earth Orientation Measurements: SPACE2004, COMB2004, and POLE2004. JPL Publication 05-6. Pasadena, CA, 20 pp.], (1) POLE2004 series, span 20 January 1900 to 20 January 2005 at 30.4375-day intervals, and (2) COMB2004_noon series, span 20 January 1962 to 22 January 2005 at daily intervals, are studied using a newly developed spectral analysis and digital filtering technique [Pan, C., 1998. Spectral ringing suppression and optimal windowing for attenuation and Q measurements, Geophysics 63, 632–636; Pan, C., 2001. Gibbs phenomenon removal and digital filtering directly through the fast Fourier transform, IEEE Trans. Sig. Process. 49, 444–448] to remove the spectral smear due to finite data truncation from the spectra and to suppress incoherent background noises. The older polar motion observations before 1962 are found much noisier but are still reliable measurements for the Chandler and annual wobbles. Results from both spectral analysis and digital filtering of the polar motion data indicate that the Chandler wobble possesses multiple frequencies to exhibit the envelope characteristics of resonant coupled oscillations. The appearance of apparent single Chandler peak is because the length of the polar motion data chosen for analysis is shorter than the main resonance cycle of the Chandler wobble and in a time span within the modulation envelope of the oscillations; the close splits of the Chandler frequency are hence concealed. Using the five Chandler frequency components found from analysis of the 105-year POLE2004 series and the annual wobble, synthetic simulation equivalent to same lengths of the polar motion observations is made. The simulation demonstrates the application of the new technique in the spectral analysis and digital filtering, and also confirms the relationship between the Chandler frequency split and data length, time span and time sampling interval shown by the observations. This factual finding raises a serious question on the conventional modeling of the Earth's rotation that gives only a single Chandler frequency. The theoretical aspects of the problem are briefly reviewed. The linearization of the Liouville equation has over-neglected the contribution to the Chandler frequency excitation from the same motion and mass redistribution that excite the Chandler amplitude. This leaves out the coupling of different parts of the Earth and the main Earth body that will cause the Chandler frequency to split, while the Chandler wobble is still kept with a single frequency like that of a rigid Earth.

Split‐crest and immediate implant placement with ultra‐sonic bone surgery: a 3‐year life‐table analysis with 230 treated sites

Ultra-sonic bone surgery (USBS) has been recently introduced as a novel osteotomic technique. This clinical study reports on the application of this new technique to perform ridge-split procedures. Over a period of 3.5 years, 57 patients underwent a split-crest procedure with the aim to place 230 implants, 78 in the mandible and 152 in the maxilla, in order to rehabilitate nine full arches, three hemi-arcades, 43 partial bridges and 24 single crowns. The initial ridge width varied between 1.5 and 5 mm, average was 3.2 mm. The final width of the ridge ranged from 4 to 9 mm, average was 6 mm. The split length varied between 4.5 and 40 mm, average was 15 mm. Inserted implants were 3.25-5 mm in diameter however most of them (82.4%) were standard implants of 3.75 mm; implant length was classically 10-13 mm. Two hundred and twenty-eight (99.1%) out of the 230 planned implants were placed, the two non-suitable sites were in the maxilla. In the mandible, the ridge augmentation procedure was drastically eased by performing a basal longitudinal discharge notch. At second stage surgery, eight implants failed to osseointegrate; the success rate for the placed implants was 96.5%. All implants have been loaded for at least 2 months and no implant was lost after loading. One hundred and eighty-one and 77 implants have been loaded for at least 6 and 12 months, respectively. The 3-year life-table analysis of loaded implants showed a cumulative survival rate of 100%. The split-crest procedure performed with USBS showed to be safe and comfortable.

The effect of urban growth on commuting patterns in Christchurch, New Zealand

The rising demand for residential development in the urban fringe of Christchurch, New Zealand, has led to an increase in car use and lengthening journeys, both of which have serious environmental implications. In light of this, the relationship between urban form and transport was investigated in Christchurch through the analysis of journey to work data from 1991 and 2001. Low density suburban areas were found to generate and receive the highest percentages of car trips in both 1991 and 2001. It was also found that the majority of work-trips involved suburb-to-suburb commuting, rather than to the centre of the city. Average trip length did not increase substantially over this period, although increases were apparent in separate modes. Multivariate regression analysis established that the key variable determining modal split and trip length was the distance the residence was located from the central business district. Results were similar when compared to larger cities elsewhere.