Partial Depth Research Articles

Sequential search with partial depth

Using the classical framework by Wolinsky (1986) and Anderson and Renault (1999), this paper explores partial-depth search and shows that consumers search products partially when search cost is large, and firms’ prices and consumer surplus are non-monotonic in search cost.

Probing the Early History of Cosmic Reionization by Future Cosmic Microwave Background Experiments

Cosmic reionization imprints its signature on the temperature and polarization anisotropies of the cosmic microwave background (CMB). Advances in CMB telescopes have already placed a significant constraint on the history of reionization. As near-future CMB telescopes target the maximum sensitivity, or observations limited only by the cosmic variance (CV), we hereby forecast the potential of future CMB observations in constraining the history of reionization. In this study, we perform Markov Chain Monte Carlo analysis for CV-limited E-mode polarization observations such as the Lite (Light) satellite for the studies of B-mode polarization and Inflation from cosmic background Radiation Detection (LiteBIRD), based on a few different methods that vary in the way of sampling reionization histories. We focus especially on estimating the very early history of reionization that occurs at redshifts z > 15, which is quantified by the partial CMB optical depth due to free electrons at z > 15, τ z>15. We find that reionization with τ z>15 ∼ 0.008, which is well below the current upper limit τ z>15 ∼ 0.02, is achievable by reionization models with minihalo domination in the early phase and can be distinguished from those with τ z>15 ≲ 5 × 10−4 through CV-limited CMB polarization observations. An accurate estimation of τ z>15, however, remains somewhat elusive. We investigate whether resampling the E-mode polarization data with limited spherical-harmonic modes may resolve this shortcoming.

Immersive Video Coding: Should Geometry Information Be Transmitted as Depth Maps?

Immersive video often refers to multiple views with texture and scene geometry information, from which different viewports can be synthesized on the client side. To design efficient immersive video coding solutions, it is desirable to minimize bitrate, pixel rate and complexity. We investigate whether the classical approach of sending the geometry of a scene as depth maps is appropriate to serve this purpose. Previous work shows that bypassing depth transmission entirely and estimating depth at the client side improves the synthesis performance while saving bitrate and pixel rate. In order to understand if the encoder side depth maps contain information that is beneficial to be transmitted, we first explore a hybrid approach which enables partial depth map transmission using a block-based RD-based decision in the depth coding process. This approach reveals that partial depth map transmission may improve the rendering performance but does not present a good compromise in terms of compression efficiency. This led us to address the remaining drawbacks of decoder side depth estimation: complexity and depth map inaccuracy. We propose a novel system that takes advantage of high quality depth maps at the server side by encoding them into lightweight features that support the depth estimator at the client side. These features allow reducing the amount of data that has to be handled during decoder side depth estimation by 88%, which significantly speeds up the cost computation and the energy minimization of the depth estimator. Furthermore, −46.0% and −37.9% average synthesis BD-Rate gains are achieved compared to the classical approach with depth maps estimated at the encoder.

617 Indocyanine Green: Harnessing Novel Methods to Identify Burn Wound Healing Potential

IntroductionObjective determination of burn wound healing potential remains elusive and significantly impacts decision making for surgery, the extent of tissue excised intraoperatively and the use of donor site-sparing alternative tissue therapies. Indocyanine green angiography (ICGA) has promise as an adjunct to evaluate healing potential, but feasibility has limited adoption in clinical practice. Delayed fluorescence imaging of indocyanine green (ICG), in a method called second-window ICG (SWIG), is a new technique used intraoperatively to guide tumor resection via increased peritumoral endothelial permeability. The objective of this study is to examine ICGA and SWIG fluorescence in burns requiring excision and grafting, and to correlate SWIG fluorescence to microscopic localization of inflamed and necrotic tissue.MethodsDeep partial thickness, indeterminate depth or full thickness burns were identified in adult patients scheduled for excision and grafting. 24 hours prior to surgery, baseline bright light and fluorescence images were obtained before the administration of up to 5 mg/kg ICG intravenously. ICGA was performed within 5 minutes of infusion initiation. On the day of surgery, bright light and SWIG fluorescence images were obtained before and after burn excision. The excised tissue was imaged ex-vivo to determine the presence of fluorescence in the tissue compared to that remaining within the wound bed. Excised tissue was processed for histologic analysis of cellular architecture, viability, inflammation and necrosis. Macroscopic ICGA and SWIG fluorescence images were compared to the associated microscopic tissue sections to determine the presence of inflammatory infiltrate, localization of non-viable tissue, and co-localization of ICG fluorescence.ResultsICGA imaging performed preoperatively demonstrated variable fluorescence throughout the burns without a clear cutoff value to delineate deep partial versus full thickness burns. SWIG imaging revealed a speckled fluorescence pattern prior to burn excision that became diffuse after excision suggesting a potential utility of SWIG to intraoperatively identify excision completion. ICGA and SWIG fluorescence demonstrated an inverse relationship, and SWIG fluorescence was associated with non-viable tissue.ConclusionsICGA imaging alone was unreliable to delineate the need for surgical intervention. SWIG imaging of burn injuries may represent a valuable tool to guide the extent of excision intraoperatively and reduce unnecessary excision of viable tissue. Further studies are needed to understand SWIG fluorescence at the inflammation-necrosis border and how ICGA fluorescence along with SWIG can synergistically improve detection of healing potential in burn patients.

Human cadaver model as a training tool for enzymatic burn debridement (Nexobrid®): A feasibility study

ObjectivesTo determine the feasibility of using human cadavers to demonstrate enzymatic burn debridement, as a training aid for clinical staff. Material and methodsA single, fresh-frozen human cadaver was used. Prior consent had been given. Burns were created by flame and scalding. Unburned control sites were also assessed. Nexobrid® enzymatic burn debridement paste was applied to all sites, in adherence to the local clinical protocol for treating burned patients. After removal of Nexobrid®, wounds were assessed to determine if the cadaveric tissue appeared similar to what would be expected in living burned patients and whether the technique could be viable for training of burn care staff. ResultsNexobrid® had a very similar effect upon burned cadaveric skin to what would have been expected in living burned skin. Burns of partial thickness burn depth and full thickness burn depth were debrided and could be clearly identified. ConclusionsFresh-frozen human cadaveric tissue is a valid means of provision of training in the technique of enzymatic burn debridement. This finding was unexpected and shows that our understanding of the mechanism of action of Nexobrid® is incomplete.

Influence of the Shape of a Submarine Vessel on the Ice Breaking Capacity of Flexural-Gravity Waves

The severe climatic conditions of the Arctic Regions impose great constraints on traditional methods of hydrocarbon extraction. That is why underwater technologies used for raw material extraction and handling are very promising. The influential factor for the safe operation of an submarine vessel (SV) during under-ice navigation is breaking the surface through the ice cover. The traditional method of coming to the surface does not always apply because of the difficult and dangerous maneuvering and ice partial depth of the broken ice. In fact, the load that arises in the ice moves generates a system of progressive flexural-gravity waves (FGW). In case the waves are intensive to a certain extent, the ice of heavy thickness can destruct. The paper informs on an experimental study of FGW ice-breaking capacity generated due to SV of different projects running. The experiments were conducted in an ice tank. The ice destruction efficiency is determined using the ice-breaking criterion. The authors conclude that the principal factor affecting the ice-breaking capacity is not the displacement of water, but a fineness ratio of a submarine ship, as well as a cross-section ship shape. The subject of the influence of the vessel depth on FGW characteristics is explored.

Sequential Search with Partial Depth

Sequential Search with Partial Depth

Sequential Search with Partial Depth

Sequential Search with Partial Depth

Effect of web stiffeners on the lateral distortional buckling of channel section with hollow flanges

Hollow Flange Channels (HFC) have been known for their higher capacity when compared to open flange C-sections. On the other hand, the small stiffness of HFC slender web compared to their flanges limits the bending capacity to the lateral distortional buckling (LDB) strength. Welding web stiffeners can limit the web distortion and enhance the bending capacity. This paper investigates how to alleviate LDB capacity of HFCs using transverse web stiffeners. Stiffener’s spacing, depth and thickness are the parameters, modeled with different beam lengths. It is found that using the right spacing and depth of stiffeners can greatly increase the HFC capacity. Adding full depth stiffener to 4000 mm span increases the capacity by 32%. However, this percentage decreases for longer spans with partial depth stiffeners. Increasing the stiffener thickness have been found insignificant in enhancing the performance. A new formula is proposed to predict the bending capacity of stiffened HFC.

Development of Distress Progress Model for Determining the Appropriate Time for Overlaying Durability Cracks in Concrete Pavement

As far as concrete is concerned, durability distress such as alkali-silica reaction (ASR) and D-crack is recognized as a big-problem that rapidly degrades the performance. Particularly, in the case of surfaces, the deterioration speed is very fast because of the direct impact of the vehicle load and re-damage occurs quickly even if asphalt patching or concrete partial depth repair is performed. Asphalt overlay has been widely used as a rehabilitation alternative for slowing the distress progress. However, the overlay is required before the distress becomes severe to secure a good performance. The study is aimed to find an appropriate time of overlay and to predict the years of preparation time for the overlay. Through the road surface photography time series analysis, a model predicts how much damage will progress after a year according to the current condition. The appropriate distress area needed to be overlaid is quantified through the panel rating. Through the two results, it is possible to predict how much time remains until the appropriate time to overlay when the current pavement damaged area is known.

Thickness change of the Tibetan lithosphere since Early Cretaceous as revealed by Ce/Yb and Sm/Yb ratios of volcanic rocks

ABSTRACT The growth of lithospheric thickness beneath the Tibetan Plateau since Early Cretaceous is demonstrated by changes in partial melting depth of the mantle as reflected in the Ce/Yb and Sm/Yb ratios of volcanic rocks. The ratios indicate that the lithospheric thickness of the Tibetan blocks ranged between 50–90 km in most areas and between 100–120 km in several areas during the Cretaceous. It increased from 60–110 km in Eocene to 170–200 km in Early Miocene in the Lhasa block, from 110–120 km in Early Oligocene to 170–180 km in Early Miocene in the Qiangtang block, and from ~130 km in Late Palaeogene to 160–190 km in Early Miocene for the Hohxil and Kunlun blocks. The thickness of the Lhasa block thus increased ~100 km at an average rate of 3.0 mm/a during Early Cenozoic. The indicated increase in Early Miocene for the Lhasa, Qiangtang, and Hohxil and Kunlun blocks to 160–195 km nearly matches the present 160–200 km plateau lithospheric thickness as inferred from seismic tomography. It is reasonable to assume that the crust, as well as the lithospheric mantle for all blocks thickened during the Palaeogene and reached its present thickness in Early Miocene.

Simplified and advanced design for stainless steel members under concentrated transverse loading

AbstractA comprehensive investigation into the behaviour of structural stainless steel members under concentrated transverse loading is presented in this paper. A total of 34 member tests and over 500 finite element simulations have been performed covering three types of concentrated transverse loading – internal one‐flange, internal two‐flange and end one‐flange loading, three stainless steel grades – austenitic, duplex and ferritic and key influential parameters such as bearing length, web slenderness and beam span. The results have shown that existing design recommendations are conservative and that there is considerable scope for the development of more economical design guidance. New design equations are proposed that offer 10% to 20% improvements in capacity predictions over the current design formulae in EN 1993‐1‐4. These proposed design equations are to be included in the next revision of the European standards. An alternative design approach based on numerically generated reference loads – i.e. the plastic collapse and elastic buckling loads – in conjunction with strength curves, has also been proposed. This advanced FE‐based design approach allows the extension of the design scope to non‐standard cases, such as webs with partial depth stiffeners and members with web holes. The reliability of both design approaches has been successfully verified by statistical analysis.

Toward hierarchical classification of imbalanced data using random resampling algorithms

Although the class imbalance issue affects hierarchical datasets, the literature has few studies that deal with it, especially when it comes to methods to pre-process the training dataset as a whole. In this study, we present novel resampling algorithms to deal with imbalance in hierarchical datasets. To be able to process the imbalanced data, we first propose methods to retrieve the set of majority and minority label paths. The resampling algorithms were designed with respect to the depth of the label path prediction and may be used for hierarchical classification problems with single- and multiple-path labels. We propose two oversampling and two undersampling algorithms: HROS-FD/PD – Random Oversampling for Full/Partial Depth Hierarchical problems, and HRUS-PD/FD – Random Undersampling for Full/Partial Depth Hierarchical problems. While the resampling algorithms for full-depth problems deal with the data by simply processing the set of majority/minority paths, the partial depth approaches process the data in a leaf-node order way, recalculating the set of majority/minority paths at each step until reaching the root label. The experimental evaluation with 23 hierarchical datasets across different domains and characteristics, supported by statistical analysis, showed that the proposed resampling algorithms significantly improve the classification performance.

Product differentiation and equilibrium price with partial product search

Anderson and Renault (1999) show a U-shaped relationship between firms’ equilibrium prices and product differentiation. Through a simultaneous search model with partial depth, we show that such a U-shaped relationship emerges (vanishes) when search depth is fixed (chosen by consumers).

Geophysical and Geochemical Constraints on Neogene‐Recent Volcanism in the North American Cordillera

AbstractWidespread recent volcanic rocks occur across the Cordillera landward of the current/recent volcanic arc Mexico to Alaska and most other subduction backarcs. We conclude that most are produced by partial melt in the upper asthenosphere where two conditions are met: (1) thin lithosphere, shallow hot asthenosphere. Most of the Cordillera is uniformly hot with thin lithosphere such that the hot asthenosphere extends up to a sufficiently shallow depth to intersects the wet solidus; (2) wet upper asthenosphere. There is substantial water in the upper asthenosphere that reduces the solidus sufficiently for partial melting. We integrate geochemical analyses that constrain the partial melt source temperature and depth, seismic velocities that define the upper mantle temperature and partial melt zones, and seismic receiver functions that define the lithosphere‐asthenosphere boundary (LAB). Geochemical data for the Canadian Cordillera are integrated with data from the western United States. Upper mantle xenoliths indicate a dry strong lithosphere, <50 ppm H2O. A wet asthenosphere source, >250 ppm, is indicated by the volcanics, facilitating small‐scale convection. Geochemical equilibration averages ∼1,350°C, at ∼65 km. Receiver functions also define the LAB at ∼65 km for the western Cordillera, deeper in the eastern US Cordillera, and asthenosphere tomography velocities indicate ∼1,350°C. Low velocities above ∼150 km suggest a few percent partial melt that percolates upward and ponds at the base of the lithosphere until enough accumulates to locally penetrate upward. The 65‐km depth may be controlled by the spinel‐garnet phase transition. Mechanisms are discussed for the spatial distribution of recent volcanics.

Effect of soil permeability on soil–structure and structure–soil–structure interaction of low-rise structures

Earthquake-induced soil liquefaction can generate excessive damage to building structures due to significant reduction in soil effective stress. With increasing urbanisation and population growth, the performance of closely spaced buildings, such as those in towns and cities, is of greater concern where structure–soil–structure interaction (SSSI) may occur in conjunction with full or partial liquefaction. This study investigates the seismic performance of isolated and adjacent structures built on shallow foundations on soils of different permeability (i.e. with different amounts of drainage and therefore generating different amounts of excess pore water pressure) using a combination of dynamic centrifuge modelling and finite-element modelling. The results demonstrate that the reduction in free-field ground surface intensity measure (specifically, Housner intensity) due to increasing liquefaction can be correlated to an index which is the normalised integral of excess pore pressure ratio (ru) with depth. This index can express the amount of liquefaction uniquely, even when full liquefaction occurs to only partial depth, or where excess pore water pressures are increased but below the level of full liquefaction at all depths. This underlying correlation means that structural demand reduction (e.g. reduction in inter-storey drift ratio) with liquefaction (SSI effect) can be linked to either: (a) the ru–depth index; (b) the depth of the liquefaction front, which can be estimated from a liquefaction triggering analysis; or (c) the ground surface intensity amplification/attenuation in the free field from the results of one-dimensional free-field soil column analyses. Where there are adjacent structures, a strongly beneficial SSSI effect on co-seismic settlement and a detrimental effect on drift in non-liquefied soil, as observed in this and previous studies, reduced towards a null effect in both cases with increased liquefaction, with liquefaction appearing to isolate the structures from each other (at least for the configuration considered herein). This has also been linked to the amount of amplification/attenuation of surface ground motion in the free field (or amount of liquefaction) as a simple indicator of the likely importance of SSSI effects in liquefiable soil.

Effect of profiled decking on composite beam-column joints with end-plate bolted connections under column-removal scenario

In the design of structures against progressive collapse, component-based modelling has been applied to simulate the behaviour of beam-column joints under column-removal scenarios. However, only limited studies consider the effect of profiled decking on load-carrying capacity of composite joints. In composite frames, the direction of profiled sheeting is parallel to the main beam but runs transverse to supporting secondary beams. This study aimed to develop component-based models that can predict behaviour of beam-column joints with either longitudinal or transverse profiled sheeting so that engineers can design joints on both the main and the secondary beams against progressive collapse. Two composite beam-column joints with extended end-plate (EEP) connections and two with partial-depth end-plate (PEP) connections were tested under a central-column-removal scenario. For each connection type, both longitudinal and transverse profiled sheeting directions were studied. Two welded T-stub specimens were tested to obtain the behaviour of component properties. Innovative component models for concrete components and for welded T-stubs in extended end-plate joints were developed. The proposed component-based models gave acceptable predictions of composite joint behaviour. It was found that extended end-plate connections had better load-carrying capacity but lower joint rotation capacity than partial depth end-plate connections. For the same connection type (either EEP or PEP), the maximum loads of specimens with transverse sheeting were only 70% of those with longitudinal sheeting.

A novel method for making laser cut panel based daylight collector coupled to a tubular light guide

The work in this paper focuses on the development of a daylighting device which can increase the light output for longer lengths of hollow mirrored light pipe. The device proposed is passive, easy to build, and inexpensive. It uses the concept of total internal reflection in acrylic laser cut panels (LCPs) and extends the idea into a complete collector based on mathematical modelling. The novel method of fabricating laser cut panels with steep cutting angles and partial depth cuts has been discussed in this paper. This method has been combined with weight optimisation to make a lightweight yet efficient collector with no laser cuts exposed to the atmosphere. The simulation results of this collector have been compared with a flat acrylic plate coupled to a light pipe and experimental validation of simulation has been performed using a prototype. The simulation results for collector coupled to 80% reflective light pipe have shown up to 4.3 times the illuminance on model room floor as compared to light pipe with a flat plate on 21 December- the low solar altitude season for which the collector was primarily designed. Another simulation of a real dimension office space with multiple collectors shows that at least 175 lx of average illuminance is available on the work surface with 227 cm2 cross-section light pipes.

Degloving injury of the distal aspect of the limb in a horse and preventing bone sequestrum formation using multiple, partial depth cortical fenestration

Exposed or denuded bone is a common complication of wounds of the distal aspect of the limb. This clinical report describes the treatment of an extensive laceration of the right hindlimb of a 12-year-old Hungarian Warmblood Horse gelding, which was managed initially by application of hydrogel dressings to enhance autolytic debridement, subsequently, by cortical fenestration of the denuded cortical bone and by stimulating the production of granulation tissue to cover the exposed bone. An early radiographic sign of sequestrum formation (discrete changes in the outer cortex) was not seen after the injury. Six weeks later, the wound was completely covered with vascularized, healthy-appearing bed of granulation tissue, which was prepared for grafting using the punch technique. A reinforced bandage was applied for the following 7 weeks; the grafts were accepted by granulation tissue. The horse was discharged 20 weeks after admission and the owners were advised to maintain stall rest with hand walking for two weeks. Four years later the owner reported that the wound had completely healed with a good cosmetic outcome and the horse was being used in a carriage.

Mode conversion of SH guided waves with symmetry inversion in plates

When shear horizontal ultrasonic guided waves interact with thickness discontinuities in plates, the reflected and transmitted wavefields can be composed of several modes due to mode conversion. It is known that in a plate with a symmetric discontinuity, with respect to the plate’s mid-plane, mode conversion is restricted to modes that share the same symmetry as the incident mode. In this paper, we use an analytical model based on the reciprocity principle and finite element analysis to investigate mode conversion due to the interaction with different types of discontinuity, namely, non-symmetric, symmetric and geometrically symmetric but with opposite boundary conditions, that is one side of the discontinuity free and the other rigidly fixed. We show that the reflected field due to interaction with the latter is virtually restricted to modes with the opposite symmetry of the incident one, acting as a symmetry inverter discontinuity. Unlike fully symmetric discontinuities, the effectiveness of a symmetry inverter discontinuity depends on the frequency. This was proved with aid of the analytical model for a full-depth discontinuity and verified for partial depth discontinuities. Finally, symmetry inversion of SH waves was experimentally verified in acrylic plates which were symmetrically machined and filled with steel in one side to mimic a fixed boundary condition.