Modal Selection Research Articles

La selección modal en las cláusulas adverbiales introducidas por como si

The conjunction como si select usually in the subordinated adverbial clauses (modal, conditional and comparative) the tenses of the subjunctive mood cantara / cantase and hubiera / hubiese cantado. However in some papers is mentioned the possibility of the construction of como si with the tenses of indicative mood. This paper contains the analysis of the modal selection after como si and, particularly, the possible substitution of subjunctive by the indicative tenses. The analyses is realized on the ground of the corpus of Real Academia Española (CORPES XXI, CREA, CREA. Versión anotada).

Radiologic Extranodal Extension Portends Worse Outcome in cN+ TNM-8 Stage I Human Papillomavirus–Mediated Oropharyngeal Cancer

To identify adverse radiologic nodal features in cN+TNM-8 stage I human papillomavirus-related (HPV+) oropharyngeal cancer (OPC). All patients with HPV+cT1-T2cN1 OPC treated with definitive intensity modulated radiation therapy from 2008 to 2015 were included. Radiologically involved lymph node number (LN), radiologic extranodal extension (rENE), retropharyngeal LN (RPLN), and lower neck (level 4 or 5b) LN involvement were assessed on pre-treatment computed tomography/magnetic resonance imaging by a specialized head and neck neuroradiologist. Disease-free survival (DFS), locoregional control, and distant control were compared between those with versus without rENE. Univariable and multivariable analysis with stepwise modal selection were applied to identify prognostic factors for DFS. A total of 45 rENE+ and 234 rENE- were identified. The rENE+cohort had a higher number of LNs per patient (median: 6 vs 2, P<.001) and was more likely to have necrotic LNs (33 [73%] vs 132 [56%], P=.046). Median follow-up was 4.8years. Although locoregional control was high in both cohorts (93% vs 97%, P=.34), the rENE+group had inferior 5-year distant control (78% [59-88] vs 95% [91-97], P<.001) and DFS (58% [43-77] vs 90% [86-94], P<.001). In multivariable analysis, rENE+ (HR [hazard ratio] 4.3 [2.3-8.1], P<.001], T2 (vs T1) category (HR 2.1 [1.0-4.2], P=.039), smoking pack-years (HR 1.02 [1.0-1.03], P=.013), and the addition of systemic agents (HR 0.4 [0.2-0.8], P=.005) were prognostic for DFS. RPLN was prognostic for distant metastasis (HR 3.2, P=.013) but not for DFS after adjusting for rENE. Data from this contemporaneously treated cT1-T2N1 HPV+OPC cohort suggest that the presence of rENE is an independent prognostic factor withinstage I HPV+OPC. RPLN is also associated with DM risk but not with DFS.

Principles and Applications of Continuous Level Gauges in Level Monitoring of Solid Particles

In modern industries, such as electric power, medicine and food, the accurate measurement of continuous level for solid particles has played an important role in regulating the production schedule, ensuring the production automation, guaranteeing the production and personal safety. This article introduces the principles and characteristics of the level gauges usually used to measure the continuous level of solid particles at home and abroad, and analyze the effects of different work conditions on the gauges. The unsuitable work conditions and the points for attention of installation and maintenance are summarized. In a word this article provides the theoretical basis and practical guidance for the accurate modal selection and correct use of the continuous level gauges for measuring the level of solid particles in different environments and industries.

Phase-locked array of quantum cascade lasers with an intracavity spatial filter

We show a phase-locked array of quantum cascade lasers with an intracavity spatial filter based on the Talbot effect. All the laser arrays show in-phase operation from the threshold current to full power current with a near-diffraction-limited divergence angle. The maximum power is just about 5 times that of a single-ridge laser for an eleven-laser array device and 3 times for a seven-laser array device. The structure was analyzed by using the multi-slit Fraunhofer diffraction theory, showing very good agreement with the experimental results. Considering the great modal selection ability, simple fabricating process, and potential for achieving continuous wave operation, this phase-locked array may be a hopeful solution to obtain higher coherent power.

Selective excitation of surface plasmon modes propagating in Ag nanowires.

Surface plasmon modes propagating in metal nanowires are conveniently excited by focusing a laser beam on one extremity of the nanowire. We find that the precise positioning of the nanowire inside the focal region drastically influences the excitation efficiency of the different SPP modes sustained by the plasmonic waveguide. We demonstrate a spatially selective excitation of bound and leaky surface plasmon modes with excitation maps that strongly depend on the orientation of the incident linear polarization. We discuss this modal selection by considering the inhomogeneous distribution of the field components inside the focus. Our finding provides a way to discriminate the effective indices of the modes offering thus an increased coupling agility for future nanowire-based plasmonic architectures.

Modos verbales y los inductores modales en las cláusulas subordinadas adjetivas: español vs. polaco

Verbal Moods and Modal Triggers in Subordinate Adjective Clauses: Spanish vs. PolishThe aim of this article is to analyze the influence of modal triggers (semantic features of an antecedent and subordinating predicates, as well as negation operators) on the selection of mood in subordinate adjective clauses in contemporary Spanish. Moreover, the author compares the parameters of modal, syntactic, and semantic selection in Spanish and Polish. He also attempts to make some observations regarding modality differences in subordinate adjective clauses between these two languages. In Spanish, modal selection depends to a great extent on the properties of modal triggers, whereas in Polish, one of the most important factors is the semantic efficiency of hypothetical mood, which transmits certain modal content (no reality, degree of hypothesis, etc.).

Computation of Rayleigh Damping Coefficients for the Seismic Analysis of a Hydro-Powerhouse

The mass and stiffness of the upper and lower structures of a powerhouse are different. As such, the first two vibration modes mostly indicate the dynamic characteristics of the upper structure, and the precise seismic response of a powerhouse is difficult to obtain on the basis of Rayleigh damping coefficients acquired using the fundamental frequencies of this structure. The damping ratio of each mode is relatively accurate when the least square method is used, but the accuracy of the damping ratios that contribute substantially to seismic responses is hardly ensured. The error of dynamic responses may even be amplified. In this study, modes that greatly influence these responses are found on the basis of mode participation mass, and Rayleigh damping coefficients are obtained. Seismic response distortion attributed to large differences in Rayleigh damping coefficients because of improper modal selection is avoided by using the proposed method, which is also simpler and more accurate than the least square method. Numerical experiments show that the damping matrix determined by using the Rayleigh damping coefficients identified by our method is closer to the actual value and the seismic response of the powerhouse is more reasonable than that revealed through the least square method.

Semi-analytical finite-element modeling approach for guided wave assessment of mechanical degradation in bones

Numerical models based on the Semi Analytical Finite-Element method are used to study the characteristics of guided wave modes supported by bone-like multi-layered tubular structures. The method is first validated using previous literature and experimental studies on phantoms mimicking healthy and osteoporotic conditions of cortical bone, and later used to study a trilayer marrow–bone–tissue system at varying mechanical degradation levels. The results show that bone condition strongly affects the modal properties of axially propagating guided waves and indicates that L(0,3) and F(1,6) are suitable modes for assessing the mechanical condition of the bone. The work here reports suitable modal selection and their dispersion properties which would the aid in development of a transduction mechanism for mechanical assessment of bones.

Promoting active transportation modes in school trips

Urban and transportation planners have put a special focus on students' health and fitness in the past decade, however they struggle to find effective policies to promote walking and biking for school trips. Commuting to school is an opportunity to embed a regular physical activity in students' daily routines and prevent many health issues that are stimulated by physical inactivity during childhood. A three level nested logit model is introduced to explain the motives behind school trip modal selection. Four choice situations, namely walking, driving, school busing, and taking public transit are considered. This study, particularly, underscored the significance of model misspecification in terms of policy outcomes, since multinomial logit models are typically adopted in the literature and have strong and, in many cases, unrealistic assumptions. Elasticity analysis of the MNL model showed an indirect elasticity of vehicle ownership of −0.13 for non-automobile modes, while NL model provides different elasticities of −0.12, −0.20 and −0.08, respectively for public, school bus, and walk modes. This misspecification results in over estimating the reduction in the share of students who walk to school when vehicle ownership increases. Moreover, a wide range of policy-sensitive variables along with their effect magnitude was discussed and compared with the previous studies. The results showed that one percent increase in the probability of walking to school is expected for every 0.04 percent increase in auto travel time, 0.07 percent increase in the normalized-to-income cost of driving, 0.08 percent decrease in vehicle ownership, 0.03 percent increase in distance to public transit, or 2.37 percent decrease in commute distance. Safety was also found to be very influential on active commuting, such that addressing the safety concern of parents is expected to increase propensity of active commuting to school by around 60 percent.

Partitioned analysis of flexible multibody systems using filtered linear finite element deformational modes

SUMMARYThis work presents a partitioned finite element formulation for flexible multibody systems, based on the floating frame (FF) approach, under the assumption of small deformations but arbitrarily large rotations of the bodies. In classical FF of reference methods, deformational modes are normally computed by modal analysis. In this approach, free‐floating modes are eliminated from the linear model using projection techniques and substituted by a complete set of non‐linear finite rotations. In this way, all deformational modes are retained, and no modal selection is needed. The main difference between this work and a classical FF of reference formulation is an algebraic separation of pure deformational modes from rigid‐body motions. The proposed methodology presents the following advantages. First, the position and orientation of the FF has no restriction and can be freely located in the body with identical results. Second, the formulation uses only the linear finite element matrices of a classical vibration problem; hence, they can be easily obtained from linear FEM packages. Third, no selection of modes is needed, all deformational modes are retained through the filtering process. And finally, thanks to the use of localized Lagrangian multipliers (LLM), a partitioned system is obtained that can be solved iteratively and in a distributed manner by available scalable solvers. Copyright © 2014 John Wiley &amp; Sons, Ltd.

The possible designation of the Mediterranean Sea as a SECA: A case study

In view of the ongoing discussions concerning the possible designation of the Mediterranean Sea as a Sulphur Emission Control Area (SECA), a modal split model was applied to a case involving the transportation of consolidated cargoes between Thessaloniki, Greece and industrial hubs of northern Germany. A road-only option was assessed against a combined-transport route involving a ferry (Greece–Italy) and a truck-on-train (Italy–Austria) service. The logit model used considers two variables as determinants of the modal selection: transport cost and time. The data are derived from interviews with a small transport service provider, typical for Greece, and are based on actual trips made (revealed preferences). The results predict that the designation of the Mediterranean as a SECA will cause a modal shift in favour of the road-only route by 5.2%, which under certain assumptions can reach 17.1%. However, the environmental implications of the resulting modal choices, calculated through the EcoTransIT World web based tool, are positive in relation to all emissions examined. This is attributed to the longer distance of the combined-transport option in comparison to the road-only one and, the poor environmental performance of the Ro-Pax vessels basically due to the need to maintain a relatively high speed.

Modal contribution and state space order selection in operational modal analysis

The estimation of modal parameters of a structure from ambient measurements has attracted the attention of many researchers in the last years. The procedure is now well established and the use of state space models, stochastic system identification methods and stabilization diagrams allows to identify the modes of the structure. In this paper the contribution of each identified mode to the measured vibration is discussed. This modal contribution is computed using the Kalman filter and it is an indicator of the importance of the modes. Also the variation of the modal contribution with the order of the model is studied. This analysis suggests selecting the order for the state space model as the order that includes the modes with higher contribution. The order obtained using this method is compared to those obtained using other well known methods, like Akaike criteria for time series or the singular values of the weighted projection matrix in the Stochastic Subspace Identification method. Finally, both simulated and measured vibration data are used to show the practicability of the derived technique. Finally, it is important to remark that the method can be used with any identification method working in the state space model.

Research on Modal Parameter Identification of the Cable Stayed Bridges Based on the Singular Value Decomposition of the Power Spectrum

In view of the modal parameter identification when only has the output signals of the system under ambient excitations has difficulty, a new method which can identify the structural modal parameters exactly based on singular value decomposition of the power spectrum is put forward. This method is used in the modal parameter identification of a cable stayed bridge under ambient excitations, and the identification frequency is compared with the finite element computation frequency. The results indicated that this method has overcome the subjectivity in modal selection of frequency domain pick-peaking method, choose eigenfrequency and identify close modal accurately and objectively. With the advantages of practical, processing simply and fast.

The North American Third-Party Logistics Industry in 2011: The Provider CEO Perspective

The North American Third-Party Logistics Industry in 2011: The Provider CEO Perspective

Alternative modal basis selection procedures for reduced-order nonlinear random response simulation

Three procedures to guide selection of an efficient modal basis in a nonlinear random response analysis are examined. One method is based only on proper orthogonal decomposition, while the other two additionally involve smooth orthogonal decomposition. Acoustic random response problems are employed to assess the performance of the three modal basis selection approaches. A thermally post-buckled beam exhibiting snap-through behavior, a shallowly curved arch in the auto-parametric response regime and a plate structure are used as numerical test articles. The results of a computationally taxing full-order analysis in physical degrees of freedom are taken as the benchmark for comparison with the results from the three reduced-order analyses. For the cases considered, all three methods are shown to produce modal bases resulting in accurate and computationally efficient reduced-order nonlinear simulations.

Thermal, Modal, and Polarization Features of Double Photonic Crystal Vertical-Cavity Surface-Emitting Lasers

Long-wavelength vertical-cavity surface-emitting lasers (VCSELs) for photonics-on-complementary metal-oxide-semiconductor (CMOS) integration based on a double set of Si/SiO2 photonic crystal mirrors (PCMs) have been recently fabricated. In the present communication, an extensive overview about modal, polarization, and thermal features of optically pumped demonstrators is presented. Capable of operating continuous-wave up to 43°C at low thresholds, such VCSELs show single-mode polarization-stable operation at 1.55-μm with uncooled output powers in excess of 0.4 mW. This paper aims at singling out notably the device optical features arising from the excellent flexibility of the photonic architecture used. Noticeably, the light molding obtained through the engineering of Si/SiO2 photonic crystals allows for a tailored modal selection and full polarization control. Furthermore, the high-throughput cost-effective Si-based process technology developed is ideally well-suited for perspective industrial development.

Transverse Mode Selection and Bistability in Vertical-Cavity Surface-Emitting Lasers Induced by Parallel Polarized Optical Injection

Modal selection induced by parallel polarized optical injection in a vertical-cavity surface-emitting laser (VCSEL) emitting in two transverse modes is analyzed from a theoretical point of view. We show that the selection of the fundamental transverse mode can be achieved when the two transverse modes have parallel polarizations. This selection is accompanied by locking of the fundamental mode to the optically injected signal for large enough values of the wavelength detuning between the fundamental mode and the externally injected signal. The injected power needed to induce modal selection grows as the VCSEL bias current is increased for small positive wavelength detunings, while it is independent on the bias current for larger wavelength detunings. That power exhibits a minimum with respect to the injection wavelength at a value λ <i xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">min</i> that is slightly longer than the wavelength of the fundamental mode of the solitary VCSEL. We also show that the selection process exhibits bistable behavior when the wavelength of the optically injected signal increases beyond λ <i xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">min</i> . The width of the bistable region increases linearly with the wavelength of the optically injected signal. Our results show that λ <i xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">min</i> also increases linearly with the VCSEL bias current. Higher order transverse mode selection and bistability, similar to those found for the fundamental mode, are obtained when the optical injection wavelength is close to that of the higher order mode. Our results are in agreement with the experimental results reported earlier.

Modeling of environmental influence in structural health assessment for reinforced concrete buildings

One branch of structural health monitoring (SHM) utilizes dynamic response measurements to assess the structural integrity of civil infrastructures. In particular, modal frequency is a widely adopted indicator for structural damage since its square is proportional to structural stiffness. However, it has been demonstrated in various SHM projects that this indicator is substantially affected by fluctuating environmental conditions. In order to provide reliable and consistent information on the health status of the monitored structures, it is necessary to develop a method to filter this interference. This study attempts to model and quantify the environmental infl uence on the modal frequencies of reinforced concrete buildings. Daily structural response measurements of a twenty-two story reinforced concrete building were collected and analyzed over a one-year period. The Bayesian spectral density approach was utilized to identify the modal frequencies of this building and it was clearly seen that the temperature and humidity fluctuation induced notable variations. A mathematical model was developed to quantify the environmental effects and model complexity was taken into consideration. Based on a Timoshenko beam model, the full model class was constructed and other reduced-order model class candidates were obtained. Then, the Bayesian modal class selection approach was employed to select the one with the most suitable complexity. The proposed model successfully characterizes the environmental influence on the modal frequencies. Furthermore, the estimated uncertainty of the model parameters allows for assessment of the reliability of the prediction. This study not only improves the understanding about the monitored structure, but also establishes a systematic approach for reliable health assessment of reinforced concrete buildings.

Experimental Study of Transverse Mode Selection in VCSELs Induced by Parallel Polarized Optical Injection

Modal selection induced by parallel polarized optical injection is studied experimentally in a vertical-cavity surface-emitting laser (VCSEL) with emission in two transverse modes. We report that the selection of the fundamental transverse mode can be achieved when the two transverse modes have parallel polarizations. The selection of the fundamental mode is accompanied by locking of that mode to the optically injected signal for large enough values of the wavelength detuning between the fundamental mode and the externally injected signal. The injected power needed to induce modal selection grows as the VCSEL bias current is increased and exhibits a minimum with respect to the injection wavelength at a value ?min that is slightly longer than the wavelength of the fundamental mode of the solitary VCSEL. We also report that the selection process exhibits a bistable behaviour when the wavelength of optical injection increases beyond ?min. The width of the observed bistable region grows linearly with the wavelength of the optically injected signal. Selection of the higher order transverse mode is achieved when the optical injection wavelength is close to that of the higher order transverse mode. The qualitative behavior associated with the selection of the higher order mode is similar to that of the fundamental mode.

Transverse Mode Selection in Vertical-Cavity Surface-Emitting Lasers With Optical Injected Signal

The transverse mode selection induced by optical injection in a VCSEL emitting in two transverse modes is analyzed from a theoretical point of view. Different pairs of transverse modes with parallel or orthogonal polarizations are considered. In general, we show that transverse mode selection can be achieved when the two modes have parallel or orthogonal polarizations. The selection is not possible only when both modes have parallel polarizations and the mode with the lowest threshold current has a lower injection rate than the other mode. Different forms of the selection region in the injected power-injection current plane appear depending on the polarization of the transverse modes. When both transverse modes are orthogonally polarized the mode with the lowest threshold is selected when the injected power surpasses a value that depends on the injection current. However when both modes have parallel polarizations the selection region has a completely different shape because the selection of the mode is no longer possible if the injected power or the injected current are large enough. We also show that the modal selection is favoured as the frequency of the injected light becomes smaller than the frequency of the mode to be selected.