Front Elements Research Articles

In-situ and ex-situ wh-question constructions in Moro

This paper addresses the formation of wh-questions in Thetogovela Moro, a Kordofanian language spoken in the Nuba Mountains of Sudan. Moro has both in-situ and ex-situ wh-questions, but exhibits a subject/non-subject asymmetry: while non-subjects may employ either construction, subjects must appear in the ex-situ form. Ex-situ wh-questions are analyzed as wh-clefts, and they share several properties with clefts and relative clauses. The fronted element is marked with a cleft particle and for noun phrases, a demonstrative that we analyze as a relative pronoun is used. Verbal tone patterns are those that are found in dependent clauses rather than main clauses. Subject questions, clefts and relative clauses are marked with a verbal prefix é- , while non-subject questions, clefts and relative clauses are marked with a verbal prefix ə́- . We analyze these prefixes as dependent clause markers and provide evidence of additional dependent clause uses in the language. Finally, non-subject wh-questions bear an optional particle nə́- on the subject and/or verb. We offer several arguments that this is best analyzed as a complementizer

Bridging the Visible Spectrum to Telecom Gap with SiC Nanophotonic Spectral Translation

Abstract Visible range to telecom band spectral translation in SiC/Si can be accomplished using wavelength selector under appropriate optical bias, acting as reconfigurable active filters. In this paper we present a monolithically integrated wavelength selector based on a multilayer SiC/Si integrated optical filters that requires optical switches to select wavelengths. The selector filter is realized by using a double pin/pin a-SiC:H photodetector with front and back biased optical gating elements. Red, green, blue and violet communication channels are transmitted together, each one with a specific bit sequence. The combined optical signal is analyzed by reading out the generated photocurrent, under different background wavelengths applied either from the front or the back side. The backgrounds acts as channel selectors that chooses one or more channels by splitting portions of the input multi-channel optical signals across the front and back photodiodes. The transfer characteristics effects due to changes in steady state light, irradiation side and frequency are presented. The relationship between the optical inputs and the digital output levels is established.

Fronting, background, focus: A comparative study of Sardinian and Icelandic

There is a superficial similarity between fronting phenomena, attested in Sardinian and Icelandic. Nevertheless, the two languages are, radically different as to the pragmatic interpretation associated with, fronting. It is argued that the differences and similarities alike can, follow from an account that takes pragmatic features, that is, features, encoding elements of information structure, to be syntactically projected, and checked. In particular, Sardinian fronting creates narrow focus on, the fronted element, whereas the remaining part of the clause is backgrounded. In Icelandic, the clause is associated with maximal focus out, of which the fronted element has been back-grounded. From this basic, difference it follows that the languages are each other's mirror reflex, with respect to some fundamental patterns, including the definiteness, effect and locality restrictions encountered in Icelandic but not in, Sardinian. Furthermore, it follows that the languages are alike in that, they disallow fronting of purely functional elements such as auxiliaries. Lastly, the languages are superficially similar in the sense that, fronting obeys a subject gap condition, which however comes from a, distinct source in each language. The final section of the paper is, concerned with a general discussion on language variation.

Left Branch Extraction in Korean

This paper aims to examine the possibility of the Left Branch Extraction (LBE) and the presence/ absence of the Left Branch Condition (LBC) in Korean in relation to Bo?kovi?s (2005) NP/DP parameter. Based on Bo?kovi?, it is assumed that Korean belongs to NP languages in contrast to DP languages. Extending Choe (2009) and Kim (2011) with a critical review, it is argued that LBE in Korean is basically possible and hence LBC is not operative in spite of the prevalent LBC effects. Evidence comes from the overt movement of null operators by Choe (2009) and the overt movement of lexical operators. A response on grammaticality judgements on the data of lexical operators is provided and the grammaticality seems to be marginal with a wide range of speaker variation. However, the marginality in grammaticality shows a sharp contrast to English data which are completely ungrammatical belonging to DP languages. Based on the improvement of data with heavy syllable and stress followed by a pause, I propose that LBE in Korean is motivated by the focus feature and constrained by the weight of prosody. Furthermore, I suggest that LBE in Korean is allowed as long as an association could be made between the fronted elements and the host noun by prosody while the association is made by agreement in SC type languages. The semantic import brought by the focus feature and the movement possibility constrained by the prosodic weight gives an implication that LBE in Korean should be treated involving both syntax-semantics and phonology.

A simple and efficient XFEM approach for 3-D cracks simulations

In this work, a simple and efficient XFEM approach has been presented to solve 3-D crack problems in linear elastic materials. In XFEM, displacement approximation is enriched by additional functions using the concept of partition of unity. In the proposed approach, a crack front is divided into a number of piecewise curve segments to avoid an iterative solution. A nearest point on the crack front from an arbitrary (Gauss) point is obtained for each crack segment. In crack front elements, the level set functions are approximated by higher order shape functions which assure the accurate modeling of the crack front. The values of stress intensity factors are obtained from XFEM solution by domain based interaction integral approach. Many benchmark crack problems are solved by the proposed XFEM approach. A convergence study has been conducted for few test problems. The results obtained by proposed XFEM approach are compared with the analytical/reference solutions.

Numerical study on crashworthiness assessment and improvement of composite carbody structures of tilting train using hybrid finite element model

This paper describes the numerical results on crashworthiness assessment and improvement scheme of tilting train made of composite materials. The bodyshell of tilting train was composed of aluminum honeycomb sandwich panels and carbon-fabric/epoxy laminate composites. The input parameters for numerical analysis were obtained from material tests. Crashworthiness analysis of the tilting train was conducted using the explicit finite element analysis code LS-DYNA3D and according to four collision scenarios of the Korean railway safety rule. The hybrid finite element modeling technique, which is made up of 2D shell and 3D solid elements for three cars in the front and 1D equivalent element for the rest cars in the rear, was introduced to ensure fast and accurate design verification for crashworthiness of railway vehicle. The numerical results showed that hybrid modeling technique was an economical approach for the analyzed results, finite element modeling, and calculating time in comparison with conventional modeling method using 2D shell and 3D solid elements for railway vehicles.

Markedness in Writing: A Case of EFL Students

Theme is the element which serves as the point of departure of the message; it is that which the clause is concerned (Halliday, 1994). One of the themes in Halliday’s (1994) model is marked theme in which there are some elements put in the theme position that frequently indicate notions such as validation of internal evidence; location in discourse time/space and writer viewpoint (Davies, 1989 as cited in Gosden, 1992). Such fronted elements, often at sentence boundaries, commonly have the function of textual organization by signaling changes and turns in real-world and discourse circumstances. This study made frequency and functional analysis of marked theme used in students’ composition writings. This study was carried out on the corpus of 180 compositions come from narrating three pictorial by sixty students- 20 sophomore, 20 junior, and 20 senior- majoring in Teaching English as Foreign Language. Students narrated these stories in three sessions of 45 minutes. The gathered data, 180 compositions, were analyzed in terms of marked theme based on Halliday’s (1994) model of thematic organization. The results illustrated significant differences between the three groups regarding their use of marked theme.

The diffraction index, its application and a brief description

People having an interest in the image quality of a lens or other optical unit used with a camera will find that there are occasions when there is a need to consider the performance of one lens in relation to another. Such an interest can arise from a simple curiosity, to a serious assessment of capabilities with an alternative system. Circumstances can, however, occur where the only information readily available to make a comparison between lenses may simply be the specification of focal length and a relative aperture, or even just the size of aperture involved. In more extreme circumstances, it may only be possible to glean some estimate of the aperture size for the optical unit or lens of interest by a close visual examination of an illustration or diagram. In such instances, it then becomes necessary to produce an initial estimate of image quality that can be based on a characteristic common to all lenses and optical systems used to produce the primary image. A characteristic that meets this requirement is that of diffraction. The phenomenon of diffraction, caused by the necessity of always having an aperture stop in the optical system, thereby becomes the attribute suggested here as a means of ranking the potential for image quality possible with a given lens or system in relation to a range of other optical systems available for the application. Diffraction, though a primary consideration when assessing image quality, is not the only significant factor to be regarded as a guide to the standard of image quality that may be involved. Details of other factors that, in an ideal world could provide further guidance to quality, are, however, not necessarily readily available when needed. As a result, and in the absence of further information, it needs to be born in mind that there will be some uncertainty as to the degree of precision expressed by any assessment based on diffraction effects alone. However, since diffraction is a fundamental feature with all optical systems, it can provide a general indication of the performance that could be expected. The numerical value for a diffraction index (DI), as described here, is given by dividing the circumference, at the maximum diameter for the aperture stop in an optical system, by the area of the aperture stop at that setting. The result of this calculation is to reduce the effect of diffraction on image quality, due to the aperture effect, in inverse proportion to the area of the aperture, in accordance with established theory and practice. For the purpose described here, the most meaningful aperture stop size to be used when calculating the DI is that indicated by the relative aperture, where the aperture size (d) is shown by the relationship: d5e/n, where e is the focal length and n is the relative aperture. Alternatively, measurement of the first glass surface in a prime lens or optical system may be used as representing the aperture stop, though the results obtained using this measurement can be misleading, for example, when optical systems with a very wide field of view are being considered. This is due to the large size of front and rear elements used in their design to ensure even illumination across the image area. In practice, there can be a divergence in the values obtained depending on which method is used in measuring, or estimating, the size of an aperture. Where a zoom lens is under consideration, then the largest aperture size indicated by the relative aperture settings must be used. It follows from this that, when calculation of the DI is expressed by a smaller index number, then the image quality can be expected to have improved. It is The MS was accepted for publication on 30 March 2011. * Corresponding author: G. H. Thomson, Strut & Thomas, 57 Winslow Field, Great Missenden, Buckinghamshire HP16 9AR, UK; email: rssat@hotmail.co.uk 65

X-FEM Applied to Three-Dimensional Curvilinear Crack Front

A three-dimensional extended finite element algorithm coupled with the level set method is developed for curvilinear crack front problems. This method does not need to force the discontinuities to be in conformity with the mesh. In order to compute the pointwise stress intensity factors along the curvilinear crack front, an orthogonal curvilinear coordinate system is constructed at the intersection point between the crack front and a surface of the crack front element. As the crack surface is expressed by the level set method, no explicit meshing of the crack geometry emerges on the crack front. This makes the domain integral more difficult. An independent grid of hexahedral cells around the crack front needs to be built as the virtual extension domain for accomplishing the domain integral. To assess the accuracy of the approach, an example with semi-elliptic crack surface is considered. The results show excellent agreement with the results calculated by the standard finite element method and those obtained from the literature.

Aspectos da categoria foco no português de Angola

Nosso trabalho tem como objetivo apontar a categoria sintático-discursiva foco no português de Angola partindo de uma noção e tipologia específicas para essa categoria. A partir de uma interface morfossintaxe/discursiva, consideramos as sentenças clivadas e as pseudoclivadas como veiculadoras de foco por apresentarem uma leitura especificacional, em que há a obrigatoriedade de predicação de um valor a uma variável, disparando as leituras de ‘contrastividade’, ‘exclusividade’ e ‘exaustividade’, próprias do constituinte focalizado. Apresentamos, portanto, uma análise para o foco no português angolano, a partir da tipologia para as sentenças clivadas e pseudoclivadas realizadas com os estudos do português brasileiro. As sentenças tradicionalmente classificadas como ‘interrogativas clivadas sem cópula’ recebem, em nosso trabalho, uma proposta de análise em que consideramos esse tipo de sentença fora do âmbito das clivadas. Consideramos que o elemento fronteado que recebe a leitura de foco é seguido de uma partícula focalizadora apontando para um foco controlado gramaticalmente.

Optical design and multi-objective optimization with fuzzy method for miniature zoom optics

In this paper a thinning L-type zoom lens design was proposed to exploit the reflecting and refracting surfaces connected by a prism. However, in the L-type designs, the modulation transfer function (MTF) value is comparatively low compared with that in its coaxial counterparts. If we increase the MTF, that would cause the relative illuminace (RI) degradation. We propose a combination of the Taguchi method and fuzzy approach to improve both the RI and MTF in L-type zoom systems. The resulting experimental values of orthogonal array L9 of the Taguchi method were used as inputs for fuzzy approach to obtain the MPCI value. The MPCI value was then analyzed by variance, revealing that the two most significant factors were (1) the surface 7 to image length and (2) the semi-aperture of the front element. In our proposed method, the appropriate weight of MTF and RI for the inputs of fuzzy controllers increased the MTF by 3.74%, but the RI only reduced by 0.13% in the systematic wide-angle end, respectively.

Cartesian oval representation of freeform optics in illumination systems

The geometrical method for constructing optical surfaces for illumination purpose developed by Oliker and co-workers [Trends in Nonlinear Analysis (Springer, 2003)] is generalized in order to obtain freeform designs in arbitrary optical systems. The freeform is created by a set of primitive surface elements, which are generalized Cartesian ovals adapted to the given optical system. Those primitives are determined by Hamiltonian theory of ray optics. The potential of this approach is demonstrated by some examples, e.g., freeform lenses with collimating front elements.

Some trace elements in front and rear dorsal ordinary muscles of wild and farmed bluefin tuna ( Thunnus thynnus L. 1758) in the Turkish part of the eastern Mediterranean Sea

The levels of trace metals of front (F) and rear (R) dorsal ordinary muscles (dom) of wild and farmed bluefin tuna (BFT) were determined by atomic absorption spectrometry. Wilds were obtained from Antalya Bay and farmed were taken from a fish farm in Ildir Bay (Izmir), during spring to early summer. The accuracy of the method was checked standard reference material (NRCC-DORM-2 Dogfish Muscle). Mean trace element content of the wild samples (Fdom and Rdom, respectively) was found as: Cu, 0.790 and 0.591; Mn, 0.084 and 0.096; Ni, 0.101 and 0.124; Zn, 4.788 and 5.577; Fe, 7.670 and 9.222 (μg g −1 wet wt.). Values for farmed were detected as Cu, 0.581 and 0.453; Mn, 0.111 and 0.139; Ni, 0.072 and 0.092; Zn, 4.631 and 3.380; Fe, 4.957 and 7.156 (μg g −1 wet wt.). The results were compared with literature values.

Magnifications of single and dual element accommodative intraocular lenses: paraxial optics analysis

Using an analytical approach of paraxial optics, we evaluated the magnification of a model eye implanted with single-element (1E) and dual-element (2E) translating-optics accommodative intraocular lenses (AIOL) with an objective of understanding key control parameters relevant to their design. Potential clinical implications of the results arising from pseudophakic accommodation were also considered. Lateral and angular magnifications in a pseudophakic model eye were analyzed using the matrix method of paraxial optics. The effects of key control parameters such as direction (forward or backward) and distance (0 to 2 mm) of translation, power combinations of the 2E-AIOL elements (front element power range +20.0 D to +40.0 D), and amplitudes of accommodation (0 to 4 D) were tested. Relative magnification, defined as the ratio of the retinal image size of the accommodated eye to that of unaccommodated phakic (rLM(1)) or pseudophakic (rLM(2)) model eyes, was computed to determine how retinal image size changes with pseudophakic accommodation. Both lateral and angular magnifications increased with increased power of the front element in 2E-AIOL and amplitude of accommodation. For a 2E-AIOL with front element power of +35 D, rLM(1) and rLM(2) increased by 17.0% and 16.3%, respectively, per millimetre of forward translation of the element, compared to the magnification at distance focus (unaccommodated). These changes correspond to a change of 9.4% and 6.5% per dioptre of accommodation, respectively. Angular magnification also increased with pseudophakic accommodation. 1E-AIOLs produced consistently less magnification than 2E-AIOLs. Relative retinal image size decreased at a rate of 0.25% with each dioptre of accommodation in the phakic model eye. The position of the image space nodal point shifted away from the retina (towards the cornea) with both phakic and pseudophakic accommodation. Power of the mobile element, and amount and direction of the translation (or the achieved accommodative amplitude) are important parameters in determining the magnifications of the AIOLs. The results highlight the need for caution in the prescribing of AIOL. Aniso-accommodation or inter-ocular differences in AIOL designs (or relative to the natural lens of the contralateral eye) may introduce dynamic aniseikonia and consequent impaired binocular vision. Nevertheless, some designs, offering greater increases in magnification on accommodation, may provide enhanced near vision depending on patient needs.

Split partial second pass design for SWRO plants

All over the world, the reverse osmosis (RO) desalination plants are providing populations and industries with high quality freshwater. There are various requirements on water quality produced by RO desalination plants depending on final purpose of water usage. In recent years, the requirement for low Boron concentrations in RO permeate was the main parameter to be considered in designing many seawater RO systems. Beside the development of new RO membranes with improved Boron rejection, there are also other design options which can help to achieve required product quality. One of such options is also Split Partial Second Pass (SPSP) RO design. The principle of a SPSP design is based on the fact, that front elements in RO pressure vessel are always producing better permeate quality than elements at the back of the pressure vessel. In order to take advantage of better permeate quality at the front of the vessel in SPSP design, permeate is collected from both sides of the pressure vessel. Low TDS front permeate is than sent directly to final product line, while higher TDS back permeate is treated by partial second pass RO plant. At the end of the process, both permeate streams are blended together to create the final product of required quality. The SPSP design allows to select the right ratio between front and back permeate in order to obtain final product of required quality in terms of Boron, TDS and other quality parameters. The SPSP design provides cost effective option by minimizing the size of the second pass RO, which allows substantial savings on capital investments aswell as in operating cost of the plant. This paper will present in more details the SPSP design option and requirements, the important parameters influencing SPSP design and different ways of the control, and finally it will discuss benefits and savings resulting from this RO design option. It will also present actual operating data from seawater RO plant using this design option.

Calibration of Field II using a convex ultrasound transducer

Field II is an ultrasound simulation program capable of simulating the pressure scattering from inhomogeneous tissue. The simulations are based on a convolution between spatial impulse responses from the field in front of the transducer and the volt-to-surface acceleration impulse response of the transducer. For such simulations to reflect actual measured intensities and pressure levels, the transducer impulse response is to be known. This work presents results of combining a modified form of a 1D linear transducer model originally suggested by Willatzen together with the Field II program to calibrate the pressure and intensity simulations of a 128 element convex medical transducer with elevation focus at 70 mm. The simulations are compared to pressure measurements from a transducer driven at 4.0 MHz using a research scanner with a commercial transducer amplifier from BK Medical (Herlev, Denmark). As input waveform to the Field II model we measured the output voltage of the research amplifier. The peak voltage was limited to 31 V to avoid too high non-linear effects. We measured the hydrophone output from three transducer front elements by averaging 40 shoot sequences on each element using a remotely controlled Agilent MSO6014A oscilloscope. The pressure along the center line in a distance of 33 mm, 72 mm, and 112 mm from each element was measured as well as the intensity in the elevation plane in each depth.Results show that the 1D modeling of the linear transducer impulse response predicts the pulse waveforms satisfying. We show a root mean square error of approximately 26% on the pressure prediction and a root mean square error on the intensity prediction from 5.8–16.2% from 72 mm to 112 mm, and an average of 15.4% at 33 mm, when a 1.7 dB amplitude correction is made.

Evaluation of the performance of accommodating IOLs using a paraxial optics analysis

We employed an analytical approach to evaluate the key parameters for the potential design optimisation of accommodating intra-ocular lenses (AIOL) and to use these parameters to predict their accommodative performance. Paraxial thin-lens equations to predict the accommodative performances of single-element (1E) and two-element (2E) AIOLs were developed. 2E-AIOLs with either mobile front or back lens elements were analysed as well as 1E-AIOL for their accommodative performance. A paraxial model including key ocular components (corneal surfaces, pupil and retina) as well as AIOL was used to evaluate the key control parameters and optimal design configurations. A range of variants of the model, representing varying powers of front and back optical elements and with either front or back optical element mobile was tested. Optimal accommodative performance of 2E-AIOL is governed by the power combinations of its optical elements; design variants with higher positive front element power produced greater accommodative efficacy, while mobility of the front element contributed more to the accommodative performance than the back element. The performance of 1E-AIOL is primarily governed by the power of the AIOL; the higher the AIOL power, the better the accommodative performance. From an accommodative performance standpoint, the optimal design of 2E-AIOL should comprise a high plus power front element. Considering the maximum potential amounts of element translation available clinically, 2E-AIOLs are predicted to offer higher accommodative performance compared to 1E-AIOL.

Optical design and extended multi-objective optimization of miniature L-type optics

In ordinary optical design and optimization, it is difficult to strike a balance between relative illuminance (RI) and the modulation transfer function (MTF); this is even more difficult for special fold optical zoom lenses. We propose a thinning L-type zoom lens design that exploits the reflecting and refracting surfaces that constitute a prismatic lens. However, in L-type designs, the lens RI is comparatively low compared with that in its coaxial counterparts. Attempts to improve the RI also cause MTF degradation. We propose a combination of the Taguchi method and principal component analysis to improve both the RI and MTF in L-type zoom systems. We analysed an orthogonal array L9 using the Taguchi method. The resulting experimental values of the orthogonal array L9 were used as inputs for principal component analysis to obtain the total point value. The total point value was then analysed by variance, revealing that the two most significant factors were (1) the semi-aperture of the front element and (2) the surface 7 to image length. Our proposed method increased the MTF and RI by 0.16% and 0.44%, respectively, in system wide-angle ends.

Left-peripheral interactions in Sardinian

Concerning the phenomena commonly attributed to the left periphery, Sardinian does not differ from Romance languages with respect to clitic left dislocated topics, right dislocation, contrastive focus and wh-interrogatives. However, in Sardinian, there are some crucial differences in the organisation of the left periphery, compared to Italian or Spanish: First, whereas contrastive focus constructions in these languages show non-predicative, i.e. referential fronted constituents, Sardinian also allows fronted predicative elements. Second, a fronted element in Sardinian must not necessarily have contrastive focus, but is, most of the time, interpreted as having information focus. Furthermore, fronting of predicative and non-predicative elements is particularly common in yes/no questions. Fourth, Sardinian disposes of an alternative strategy to mark these polar questions via the question particle a. Finally, neither focus fronting nor question-marking through the question particle are allowed in wh- and in negated interrogative contexts. The main issue to be addressed in this paper is how the interaction between focus fronting, question-marking, negation and also topicalisation can be formalised and explained in the cartographic framework of Rizzi (1997) and, as an alternative, in a dynamic model of the feature-driven minimalist approach of Chomsky (1995ff.).

The clausal left periphery in child Spanish and German

Evidence from child language development supports the position that overt subjects in Southern Romance languages are left-peripheral, Topic-Focus constituents. Specifically, overt subjects begin to be used at the same time as other less controversially left-peripheral, Topic-Focus constituents, such as fronted objects and wh-questions. However, this interpretation of the data would be much more compelling if it could be shown that these constituents do not emerge at the same time in the speech of children learning languages in which overt subjects are obligatory and largely independent of discourse considerations, such as German. To this end, we examined the speech of three longitudinally studied Spanish-speaking children, Carlos, Eduardo and Graciela, and the speech of two longitudinally studied German-speaking children, Simone and Caroline. We also examined the German data of Katrin and Andreas, which was collected on a single day for each. While the Spanish-speaking children begin productively using overt subjects, fronted objects and wh-questions at a statistically similar point in development, the German-speaking children's data show that overt subjects begin to be used significantly earlier than do fronted elements and wh-questions. This supports the argument that child Southern Romance and child German are different with respect to the timing of the development of these constituents. We believe that this reflects the children's early knowledge of the structure of their target adult languages, which in the case of Southern Romance, includes left-peripheral, discourse-sensitive subjects.