Frame Boundary Research Articles

Behaviour of composite frames with castellated steel beams at elevated temperatures

The behaviour of composite frames with castellated steel beams at elevated temperatures is investigated, and the results obtained were compared with the companion results of simply supported composite castellated steel beams. Overall, it is aimed to investigate the effect of axial and rotational restraining of the steel beam via rigid connections with protected steel columns at elevated temperatures. A previously reported finite element model for the analysis of composite beams in fire was extended to perform the nonlinear analyses of composite frames at elevated temperatures. The finite element model has accounted for the frame geometries and boundary conditions, nonlinear material properties of steel, concrete, profiled steel sheeting, longitudinal and lateral reinforcement bars as well as shear connection behaviour at ambient and elevated temperatures. The thermal properties at the steel beam top flange/profiled steel sheeting and profiled steel sheeting/concrete elements interfaces were considered in the thermal heat transfer analysis that allowed the temperatures to be accurately predicted in the composite slab during fire exposure. The comparison of composite frames and composite beams behaviour has shown that if the columns were sufficiently protected and the connection maintained its rigidity during fire exposure, such that it can restrain the composite beam thermal expansions, this would result in considerable reduction in fire resistances of the composite frames compared with that of simply supported composite beams. This is attributed to the premature failure at elevated temperatures due to local buckling at the bottom flange of the steel beams in the frame connections. Furthermore, the variables that influence the fire resistance and behaviour of the composite frames comprising different load ratios during fire, different fire curves, presence of web openings and different steel grades were investigated by parametric studies. It is shown that the strength of steel and the fire scenarios have a considerable effect on the time–displacement behaviour and fire resistances of the composite frames.

Improvement of the Quality of Reconstructed Holographic Images by Extrapolation of Digital Holograms

The work is devoted to investigation of noise in reconstructed holographic images in the form of a system of fringes parallel to the hologram frame boundaries. Mathematical and physical interpretation is proposed together with an algorithm for reduction of this effect by extrapolation of digital holograms using bicubic splines. The efficiency of the algorithm is estimated and examples of its application are presented.

Extrinsic Information Modification in the Turbo Decoder by Exploiting Source Redundancies for HEVC Video Transmitted Over a Mobile Channel

An iterative turbo decoder-based cross layer error recovery scheme for compressed video is presented in this paper. The soft information exchanged between two convolutional decoders is reinforced both by channel coded parity and video compression syntactical information. An algorithm to identify the video frame boundaries in corrupted compressed sequences is formulated. This paper continues to propose algorithms to deduce the correct values for selected fields in the compressed stream. Modifying the turbo extrinsic information using these corrections acts as reinforcements in the turbo decoding iterative process. The optimal number of turbo iterations suitable for the proposed system model is derived using EXIT charts. Simulation results reveal that a transmission power saving of 2.28% can be achieved using the proposed methodology. Contrary to typical joint cross layer decoding schemes, the additional resource requirement is minimal, since the proposed decoding cycle does not involve the decompression function.

A Naturally Occurring Canine Model of Autosomal Recessive Congenital Stationary Night Blindness

Congenital stationary night blindness (CSNB) is a non-progressive, clinically and genetically heterogeneous disease of impaired night vision. We report a naturally-occurring, stationary, autosomal recessive phenotype in beagle dogs with normal daylight vision but absent night vision. Affected dogs had normal retinas on clinical examination, but showed no detectable rod responses. They had “negative-type” mixed rod and cone responses in full-field ERGs. Their photopic long-flash ERGs had normal OFF-responses associated with severely reduced ON-responses. The phenotype is similar to the Schubert-Bornschein form of complete CSNB in humans. Homozygosity mapping ruled out most known CSNB candidates as well as CACNA2D4 and GNB3. Three remaining genes were excluded based on sequencing the open reading frame and intron-exon boundaries (RHO, NYX), causal to a different form of CSNB (RHO) or X-chromosome (NYX, CACNA1F) location. Among the genes expressed in the photoreceptors and their synaptic terminals, and mGluR6 cascade and modulators, reduced expression of GNAT1, CACNA2D4 and NYX was observed by qRT-PCR in both carrier (n = 2) and affected (n = 2) retinas whereas CACNA1F was down-regulated only in the affecteds. Retinal morphology revealed normal cellular layers and structure, and electron microscopy showed normal rod spherules and synaptic ribbons. No difference from normal was observed by immunohistochemistry (IHC) for antibodies labeling rods, cones and their presynaptic terminals. None of the retinas showed any sign of stress. Selected proteins of mGluR6 cascade and its modulators were examined by IHC and showed that PKCα weakly labeled the rod bipolar somata in the affected, but intensely labeled axonal terminals that appeared thickened and irregular. Dendritic terminals of ON-bipolar cells showed increased Goα labeling. Both PKCα and Goα labeled the more prominent bipolar dendrites that extended into the OPL in affected but not normal retinas. Interestingly, RGS11 showed no labeling in the affected retina. Our results indicate involvement of a yet unknown gene in this canine model of complete CSNB.

Voice conversion system using salient sub-bands and radial basis function

The objective of voice conversion is to replace the speaker-dependent characteristics of the source speaker so that it is perceptually similar to that of the target speaker. The speaker-dependent spectral parameters are characterized using single-scale interpolation techniques such as linear predictive coefficients, formant frequencies, mel cepstrum envelope and line spectral frequencies. These features provide a good approximation of the vocal tract, but produce artifacts at the frame boundaries which result in inaccurate parameter estimation and distortion in re-synthesis of the speech signal. This paper presents a novel approach of voice conversion based on multi-scale wavelet packet transform in the framework of radial basis neural network. The basic idea is to split the signal acoustic space into different salient frequency sub-bands, which are finely tuned to capture the speaker identity, conveyed by the speech signal. Characteristics of different wavelet filters are studied to determine the best filter for the proposed voice conversion system. A relative performance of the proposed algorithm is compared with the state-of-the-art wavelet-based voice morphing using various subjective and objective measures. The results reveal that the proposed algorithm performs better than the conventional wavelet-based voice morphing.

Atomic structure and crystallization processes of amorphous (Co,Ni)–P metallic alloy

This work concerns the in situ investigation of the atomic structure of (Co,Ni)–P alloys during relaxation and crystallization by high resolution transmission electron microscopy. The CoP–CoNiP alloys, in the initial state, have a hierarchical network-like disordered structure. Crystallization starts at 200–250°C on the network frame and cell boundaries. In the early stages, crystal growth occurs at the free surface, then the remaining material in the volume is crystallized. The diffusion coefficient at the start of crystallization is 1.2–2.4×10−18m2/s at 250°C and we assume that the high diffusion speed is due to surface diffusion.

Managing work-life boundaries with mobile technologies

Purpose – The purpose of this paper is to explore the role that mobile technologies play in mobile workers’ efforts to manage the boundaries between work and non-work domains. Previous theories of work-life boundary management frame boundary management strategies as a range between the segmentation and integration of work-life domains, but fail to provide a satisfactory account of technology’s role. Design/methodology/approach – The authors apply the concept of affordances, defined as the relationship between users’ abilities and features of mobile technology, in two field studies of a total of 25 mobile workers who used a variety of mobile devices and services. Findings – The results demonstrate that the material features of mobile technologies offer five specific affordances that mobile workers use in managing work-life boundaries: mobility, connectedness, interoperability, identifiability and personalization. These affordances persist in their influence across time, despite their connection to different technology features. Originality/value – The author found that mobile workers’ boundary management strategies do not fit comfortably along a linear segmentation-integration continuum. Rather, mobile workers establish a variety of personalized boundary management practices to match their particular situations. The authors speculate that mobile technology has core material properties that endure over time. The authors surmise that these material properties provide opportunities for users to interact with them in a manner to make the five affordances possible. Therefore, in the future, actors interacting with mobile devices to manage their work-life boundaries may experience affordances similar to those the authors observed because of the presence of the core material properties.

What counts? Visual and verbal cues interact to influence what is considered a countable thing.

Many famous paintings illustrate variations in what we here dub "referential depth." For example, paintings often include not only portrayals of uniquely referenced items, but also reflections of those items in mirrors or other polished surfaces. If a painting includes both a dancer and that dancer's reflection in a mirror, are there one or two dancers in the painting? Although there are two images of a dancer, both images reference the exact same dancer. Consequently, counting both may seem to violate the constraint against double counting (Gelman & Gallistel, 1978). This illustrates that determining which things "count" in a given context may not be straightforward. Here we used counting tasks paired with illustrations that manipulated referential depth to investigate the conceptual, perceptual, and language variables that may influence whether a "thing" is a "countable thing." Across four experiments, 316 participants counted items in displays that included both foreground items and items placed inside mirrors, picture frames, and windows. Referential depth and frame boundaries both influenced counting: For one thing, participants were more likely to count items contained by windows than by picture frames or mirrors. Moreover, items in mirrors were rarely counted unless they were interpreted as reflections of items "off screen." Also, the items contained inside windows were sometimes (~10% of trials) excluded from the counts, when counting them would require crossing frame boundaries. We concluded that conceptual and perceptual contexts both influence people's decisions about the physical boundaries of the to-be-counted set and which items within these boundaries are countable.

Robust, transparent and high-capacity audio watermarking in DCT domain

This paper presents a novel scheme capable of achieving robust, transparent and high-capacity blind audio watermarking. The watermark embedding is performed by modulating the vectors in the DCT domain subject to an auditory masking constraint. An algorithm has been developed to maintain the energy balance in a frequency band, thus allowing the retrieval of embedded information directly from the designated band. As the proposed watermarking scheme is implemented on a frame basis, the abrupt artefacts in frame boundaries are further rectified via linear interpolation over transition areas. The embedded watermark is shown to be imperceptible to human ears and yet robust against common digital signal processing attacks. The resulting payload capacity is as high as 848bps. Moreover, not only a 100% recovery of the watermark is guaranteed for non-attack situations but the survival rate is substantially improved in the case of lowpass filtering even at a cutoff frequency as low as 500Hz.

Fracking the Debate: Frame Shifts and Boundary Work in Dutch Decision Making on Shale Gas

The meaning of hydraulic fracturing for shale gas is contested worldwide: is it an energy game changer, a transition fuel, or a technology that poses severe environmental problems? In the Netherlands, a policy controversy developed in which fracturing was reframed from ‘business as usual’ to a potential environmental risk. This article theoretically and empirically describes this shift by arguing that the technology of hydraulic fracturing for shale gas is a boundary object that created a sphere of engagement for all sorts of actors. In this sphere, they negotiated a common but soft meaning of this technology. These negotiations consisted of frame contests. As part of those contests, the discursive strategies of framing and boundary work enabled opponents to create uncertainty about economic benefits and environmental impact. The shift in meaning transformed the issue from an economic one with standard governmental rules and regulations into a planning issue that needs more precaution.

Efficient scrolling videotext detection with adaptive temporal differential approach

This study presents an efficient algorithm for the detection of scrolling text on continuous frames. The proposed scheme adopts both spatial and temporal computation as well as pre-processing to differentiate among noise, text and background information. Scrolling text is detected using temporal differentiation among inter-frames and then the region in which the scrolling text appears is identified as a rectangle. Simulation results demonstrate that the proposed algorithm is capable of precisely differentiating scrolling text in any direction, along any of the frame boundaries without false detection or missed text. In a comparison using quantised measurements, the proposed method outperforms all competing algorithms.

Time‐varying block codes for synchronisation errors: maximum a posteriori decoder and practical issues

\begin{abstract} In this paper we consider Time-Varying Block (TVB) codes, which generalize a number of previous synchronization error-correcting codes. We also consider various practical issues related to MAP decoding of these codes. Specifically, we give an expression for the expected distribution of drift between transmitter and receiver due to synchronization errors. We determine an appropriate choice for state space limits based on the drift probability distribution. In turn, we obtain an expression for the decoder complexity under given channel conditions in terms of the state space limits used. For a given state space, we also give a number of optimizations that reduce the algorithm complexity with no further loss of decoder performance. We also show how the MAP decoder can be used in the absence of known frame boundaries, and demonstrate that an appropriate choice of decoder parameters allows the decoder to approach the performance when frame boundaries are known, at the expense of some increase in complexity. Finally, we express some existing constructions as TVB codes, comparing performance with published results, and showing that improved performance is possible by taking advantage of the flexibility of TVB codes.

Symposium 2: Assembling university learning technologies for an open world

This paper considers the emergence of social media in university teaching and learning and the capacity or universities – as complex organisations with disparate interacting parts – to respond to the shift of pedagogies and practices to open networks. Institutional learning technology environments reflect a legacy of prescriptive, hierarchical arrangements associated with enterprise systems, and are a poor fit with the heterarchical and self-organised potential for learning associated with social media and open education practices. In this paper we focus on the tensions that arise from the juxtaposition of these two orientations to learning technologies, and focus on how an emerging online sociality can destabilise established boundaries of learning and connect to other domains of practice. To do this, we examined data from three separate case studies in which participants - both teaching staff and students - reported on student engagement in learning involving social networking activity. We draw on empirical data on student practices that challenge institutional arrangements for learning, and offer insights into the assembly of extended connections for networked learning, in particular the pedagogies of collaboration, knowledge co-construction, and informal social learning. From these instances we draw attention to the interplay of competing metaphors and practices in the organisation as it encounters the potential of more open pedagogies over social and digital networks. Drawing on spatial descriptions of networked learning, we apply Callon’s (1998) notions of framing and overflows to this interplay in order to ask how learning environments were assembled and ordered: what pre-existing configurations were brought to frame and set boundaries for these networks of formal learning; and what activities overflow those boundaries and destabilise these framings. We argue that the adoption of social media by students requires a challenge to the institutional metaphors of containment that implement a default bounded environment. This involves a reappraisal of established learning environments for their pedagogical metaphors and spatial orderings that frame learning, followed by different organisational approaches to account for and enact learning that emerges from the connections, mobilities and flows of social networks. We propose a less integrated, “assembly” approach to institutional learning that attends to the open, fluid connections of networked learning. A spatial articulation of networked learning that bridges both institutional and social networks can equip the university to meet the critical challenges of emerging hybrid learning environments and the potential of more open learning environments.

Finite element thermal modeling and correlation of various building wall assembly systems

The 2009 Energy codes IECC and ASHRAE 90.1-2007 contains significant insulation changes for steel stud wall constructions regarding thermal shorts introduced by steel studs. A better understanding of industry requirements regarding U-factor calculation procedures, modeling guides, and tools, establishes the foundation for building enclosure performance evaluation as well as for new building enclosure solution development. This study compares the thermal performance of three wall systems using several modeling methods and laboratory testing. Literature suggests there are many challenges related to the thermal modeling of building walls, including proper representation of frame cavity and boundary condition. Although simple 2D finite element (FE) tool (THERM5.0) has been certified by NFRC, its limitations have not been well understood. In order to address industry challenges and to develop a better understanding of the limitations of 2D analysis, a 3D finite element analysis thermal modeling approach has been developed. This paper outlines findings from guarded hot box tests of three walls: a conventional wall, two continuous insulation walls one with spray polyurethane foam (SPF) and one without SPF; and compares the results of the testing with FEA modeling for the same three walls. The results show significantly increased performance of continuous insulation with SPF filled cavity vs. typical gypsum wall with fiberglass insulation.

Experimental Research on Seismic Capacity of the Frame Sandwich Boundary Joint

In the tall building frame structure, the traditional frame joints which are usually constructed with the high strength concrete of the columns bring many difficulties to the construction. The frame joints concreted with beams low grade concrete (named as sandwich joint) is urged intensively by the engineers. The paper introduces the experiment of two full-scale sandwich boundary joints in the middle floor under cyclic load. Based on the test result, the specimens seismic behavior on performance of load-carrying capacity, node deformation, ductility, energy dissipation capacity etc are studied. Through comparison with traditional frame boundary joints, comprehensive seismic performance of sandwich boundary joints does not significantly reduce. The engineering applications of these sandwich frame joints are proved to be feasible, and some suggestions for the engineering application of this joint are proposed.

CU Splitting on Frame Boundary for Arbitrary Resolution Video in HEVC

A highly flexible quadtree structure has been introduced in the latest high efficient video coding (HEVC) to efficiently represent video content. However, the performance of the quadtre structure would be impaired when the video resolution is not an integral multiply of the largest coding unit (CU). To address this, a new CU splitting method on the frame boundary for arbitrary resolution video is proposed to improve the coding efficiency of HEVC. This method introduces the non-square CU to extend the CU candidate set on the frame boundary when the video resolution is not an integral multiple of the largest CU size. Simulation results show that the proposed method can reduce the coding bit rate by up to 0.76% compared with the original TMuC 0.9 reference software.

Media and development: The politics of framing gender struggles in the postcolonial zimbabwean shona films

Summary To frame gender struggles is to set an agenda on what people should think about it in respect of the contradictory roles that men and women play in society and culture. In this article, three films in the Shona language – Mwanasikana (1995), Kapfupi (2009) and Nhasi tave nehama (1993) have been sampled out to explore gender struggles inherent in the Zimbabwean society. The premise of this article is rooted in the ideological doubleness of the word framing as both restrictive as well as an instrument for liberation. Framing gender in the discourses of these three films calls attention to perceiving gender struggles in certain ways and in the process manifesting as far as possible the buried narratives that are otherwise obscured in manipulated forms of representing life. It is the duty of film critics to retrieve these silenced and “other” readings because of their potential to suggest to the audiences some alternative opinions and reactions. I advance in this article that while a frame can impose what should be thought about, it does not necessarily dictate how audiences interpret its text(s). This dialectical relation of framing implied in the restriction-liberating dimension of a frame, that emerges as it were from the struggle of verbal and visual images inside a frame's boundaries, actually can predispose audiences to want to delve for alternative images of how men and women are depicted in the Shona film.

Asynchronous Evolution for Fully‐Implicit and Semi‐Implicit Time Integration

AbstractWe propose a series of techniques for hybridizing implicit and semi‐implicit time integration methods in a manner that retains much of the speed of the implicit method without sacrificing all of the higher quality vibrations one obtains with methods that handle elastic forces explicitly. We propose our scheme in the context of asynchronous methods, where different parts of the mesh are evolved at different time steps. Whereas traditional asynchronous methods evolve each element independently, we partition all of our elements into two groups: one group evolved at the frame rate using a fully implicit scheme, and another group which takes a number of substeps per frame using a scheme that is implicit on damping forces and explicit on the elastic forces. This allows for a straightforward coupling between the implicit and semi‐implicit methods at frame boundaries for added stability. As has been stressed by various authors, asynchronous schemes take some of the pressure off of mesh generation, allowing time evolution to remain efficient even in the face of sliver elements. Finally, we propose a force distributing projection method which allows one to redistribute the forces felt on boundaries between implicit and semi‐implicit regions of the mesh in a manner that yields improved visual quality.

General medical practitioners' perceived use of drug information sources with special reference to drug information centres

Abstract This study reports the current perceived use of available sources of drug information for general medical practitioners. The sample frame, of 463 GPs practising in Derbyshire, England, on January 1, 1990, provided a 74 per cent response rate to a pre-piloted questionnaire. Two printed sources, the Monthly Index of Medical Specialities and the British National Formulary (BNF) plus one personal service, fellow colleagues, were by far the most frequently used. The estimated average minimum number of days per year on which personal information services were consulted was 28.51 days compared with 63.83 days for non-personal, printed sources. Thus, if GPs are to be guided by independent sources then the BNF must be considered a prime vehicle. Drug information centres (DICs) were ranked last with 56 per cent of GPs having consulted such a source within the previous year. Use of DICs could not be predicted from GPs' characteristics or demographic data. Interviews with 101 of 106 randomly selected GPs generally confirmed questionnaire findings. However, only 41 per cent perceived themselves as users of DICs. Collation of queries from two local centres showed 25 per cent were known to be users. From interviews, discrepancies were seen to arise from accessing DICs outside the sample frame boundary plus confusion of DICs with poisons centres and hospital pharmacy departments. Thus, for use of DICs, questionnaire techniques may be unreliable unless source definition is considered. If using DICs, GPs very significantly had lower concurrent use of community pharmacists, GP colleagues and hospital consultants for general drug information

Travelling eye: the elusive digital frame and the elasticity of time in art

ABSTRACTIn this article, I will consider my video installations, Hold (2006), An Occulting Light (2007) and Lighter Darker (2008), in which I have developed a language of re-filmed frames and expanded moving image spaces, in the light of Victor Burgin's idea of the ‘remembered film’, Benjamin's ‘unconscious optics’ and Deleuze's work on painting and cinema.These works were constructed from fragments of ‘remembered films’, including The Ghost and Mrs Muir (Mankiewicz 1947) and The Cruel Sea (Frend 1953), combined with footage from actual journeys made to sites of family memory. Using re-filming techniques, alterations to frame rate and speed and experimental editing, I have begun to explore ‘affect’ in the spaces between frames in digital video where the image exceeds the original frame boundaries, oscillating between visible traces inscribed in the newly constructed sequences. My project in this practice-led research is to gain insights into ‘affect’ in relation to our perceptions as artists and spectators of movement and of the traces of time passing in paintings and film works, through the languages of the moving image.