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Processing
Kinds of Processing Terms modified by Processing Selected AbstractsNEURAL NETWORK MODELING OF END-OVER-END THERMAL PROCESSING OF PARTICULATES IN VISCOUS FLUIDSJOURNAL OF FOOD PROCESS ENGINEERING, Issue 2010YANG MENG ABSTRACT Modeling of the heat transfer process in thermal processing is important for the process design and control. Artificial neural networks (ANNs) have been used in recent years in heat transfer modeling as a potential alternative to conventional dimensionless correlation approach and shown to be even better performers. In this study, ANN models were developed for apparent heat transfer coefficients associated with canned particulates in high viscous Newtonian and non-Newtonian fluids during end-over-end thermal processing in a pilot-scale rotary retort. A portion of experimental data obtained for the associated heat transfer coefficients were used for training while the rest were used for testing. The principal configuration parameters were the combination of learning rules and transfer functions, number of hidden layers, number of neurons in each hidden layer and number of learning runs. For the Newtonian fluids, the optimal conditions were two hidden layers, five neurons in each hidden layer, the delta learning rule, a sine transfer function and 40,000 learning runs, while for the non-Newtonian fluids, the optimal conditions were one hidden layer, six neurons in each hidden layer, the delta learning rule, a hyperbolic tangent transfer function and 50,000 learning runs. The prediction accuracies for the ANN models were much better compared with those from the dimensionless correlations. The trained network was found to predict responses with a mean relative error of 2.9,3.9% for the Newtonian fluids and 4.7,5.9% for the non-Newtonian fluids, which were 27,62% lower than those associated with the dimensionless correlations. Algebraic solutions were included, which could be used to predict the heat transfer coefficients without requiring an ANN. PRACTICAL APPLICATIONS The artificial neural network (ANN) model is a network of computational elements that was originally developed to mimic the function of the human brain. ANN models do not require the prior knowledge of the relationship between the input and output variables because they can discover the relationship through successive training. Moreover, ANN models can predict several output variables at the same time, which is difficult in general regression methods. ANN concepts have been successfully used in food processing for prediction, quality control and pattern recognition. ANN models have been used in recent years for heat transfer modeling as a potential alternative to conventional dimensionless correlation approach and shown to be even better performers. In this study, ANN models were successfully developed for the heat transfer parameters associated with canned particulate high viscous Newtonian and non-Newtonian fluids during an end-over-end rotation thermal processing. Optimized configuration parameters were obtained by choosing appropriate combinations of learning rule, transfer function, learning runs, hidden layers and number of neurons. The trained network was found to predict parameter responses with mean relative errors considerably lower than from dimensionless correlations. [source] DIMENSIONLESS CORRELATIONS FOR CONVECTIVE HEAT TRANSFER IN CANNED PARTICULATE FLUIDS UNDER AXIAL ROTATION PROCESSINGJOURNAL OF FOOD PROCESS ENGINEERING, Issue 2010MRITUNJAY DWIVEDI ABSTRACT Dimensionless correlations for estimating heat transfer coefficients (U and hfp) in canned high viscosity Newtonian liquids (with and without particles) were developed using stepwise multiple nonlinear regressions of statistically significant dimensionless groups using tangent as an estimate and Newton as search method. Data on overall heat transfer coefficient U and fluid-to-particle heat transfer coefficients hfpwere obtained for several processing conditions and were analyzed separately for particle and particle-free conditions. In free axial mode, a newly developed form, combining natural and forced convection, provided higher R2 = 0.93. In the absence of particles in end-over-end mode, introducing natural convection term (Gr × Pr), improved R2 from 0.81 to 0.97. Combination of the reel radius, radius of the can and radius of the particles was chosen as characteristics length. PRACTICAL APPLICATIONS Most earlier dimensionless correlations for a canned liquid particulate mixture subjected to free axial mode of agitation are present for either U or hfp individually due to the difficulties in obtaining time,temperature profiles of the liquid and particles simultaneously; however, the time,temperature prediction at the particle center requires appropriate correlations for both U and hfp and cannot be made with only one of these coefficients. Additionally, importance of natural convection in forced convection heat transfer correlations has been demonstrated by developing the U and hfp correlations using the mixed convection approach as the combination of natural and forced convection heat transfer. These developed correlations would help in modeling the time,temperature profiles of a canned particulate mixture and will be helpful in determining the contribution of natural and forced convection heat transfer. These dimensional numbers would give a better understanding of the physical phenomenon and can also be easily used for scale-up purposes. [source] EFFECT OF HIGH-PRESSURE PROCESSING ON TEXTURE AND DRYING BEHAVIOR OF PINEAPPLEJOURNAL OF FOOD PROCESS ENGINEERING, Issue 3 2009A.R.P. KINGSLY ABSTRACT The effect of high-pressure processing on texture and drying behavior of pineapple slices was investigated. Pineapple slices were high pressure processed at 50, 100, 300, 500 and 700 MPa at 25C for 10 min. The control, hot water-blanched and high-pressure processed samples were then dehydrated at 70C. Application of high pressure reduced the sample hardness, springiness and chewiness while it had no significant effect on cohesiveness of pineapple. Elevated pressure treatment (,500 MPa) reduced drying time more effectively than for the other pretreated samples. Experimental dehydration data were empirically fitted using six thin-layer drying models. Among the models tested, logarithmic model best described the drying behavior of pineapple slices. The effective moisture diffusivity was found to increase with an increase in the level of pressure up to 500 MPa, and the samples processed at 500 and 700 MPa had higher diffusivity values than blanched samples. PRACTICAL APPLICATIONS This work shows that high-pressure blanching of pineapple can be an alternative for hot water blanching, before dehydration. The results may find application in development of quality snack food from pineapple fruits. [source] RECOVERY OF SINAPIC ACID FROM A WASTE STREAM IN THE PROCESSING OF YELLOW MUSTARD PROTEIN ISOLATEJOURNAL OF FOOD PROCESS ENGINEERING, Issue 2 2008N. PRAPAKORNWIRIYA ABSTRACT A large amount of waste permeates generated from the processing of yellow mustard protein was concentrated fivefold using a nanofilter with a molecular weight cut off of 1,000 Da, while approximately 74% of sinapic acid was retained. Sinapic acid was then released from sinapine, its esterified form, by an alkaline hydrolysis. The hydrolyzed solution was acidified to prevent oxidation of the sinapic acid and to precipitate the remaining proteins. Subsequently, sinapic acid and other phenolics were extracted by a two-stage extraction using a mixture of diethyl ether and ethyl acetate (1:1), 165-min extraction time and permeate-to-solvent ratio of 1:2. Approximately 95% of the sinapic acid in the acidified permeate was finally concentrated in the solvent phase. PRACTICAL APPLICATIONS This development has led to an economical process to recover phenolics and to treat effluent from a process of oilseed protein while reducing the use of water during the extraction of protein. A reduction of water usage makes the processing of oilseed protein isolate more economically attractive, and the recovered phenolics may find a use as a nutraceutical. The developed process is not only limited to the recovery of phenolics from mustard, but also applied for recovering phenolic acids, specifically sinapic acid, from waste water from membrane processing of protein from mustard and similar polyphenol-containing oilseeds. [source] LETHALITY CONTRIBUTION FROM THE TUBULAR HEAT EXCHANGER DURING HIGH-TEMPERATURE SHORT-TIME PROCESSING OF A MODEL LIQUID FOODJOURNAL OF FOOD PROCESS ENGINEERING, Issue 4 2004G.B. AWUAH ABSTRACT Experiments were conducted using Bacillus stearothermophilus spores in 0.5% w/w carboxymethylcellulose suspension to evaluate come-up contributions from the tubular heat exchanger. A lab-scale UHT/HTST simulator that allowed samples to be collected at the exit of the heat exchanger and holding tube was used with operating temperatures up to 270F. The bulk mean residence time in the heat exchanger ranged from 30 to 89 sec, while that in the holding tube ranged from 4 to 14 sec. It was observed that between 40% and 51% of the cumulative lethality () at the exit of the holding tube, was contributed by come-up in the tubular heat exchanger. This come-up contribution was determined on the basis of having anof 8.5 min in the holding tube alone. It was evident that come-up lethality will depend on product initial temperature, residence time and temperature history in the heat exchanger, with higher temperatures obviously contributing more lethality. Therefore, the entire aseptic system becomes even more complex since several critical parameters need to be monitored, controlled and documented. Experimental data compared favorably with computer-simulated data using the AseptiCALÔ software, with the software package giving more conservative results. Ultimately, come-up credit (CUC) should be tested on a pilot scale or industrial setup by way of reduced residence time (i.e. increased fluid flow rate), reduced holding tube length or temperature in order to determine if CUC can be applied towards the lethality required for the product. Monitoring and control devices become critical to ensure consistency and reproducibility in product residence time and time,temperature history, in the tubular heat exchanger. [source] PROCESSING AND ACCEPTABILITY OF FRIED CASSAVA BALLS ("AKARA-AKPU") SUPPLEMENTED WITH MELON AND SOYBEAN FLOURSJOURNAL OF FOOD PROCESSING AND PRESERVATION, Issue 2 2007CHIEMELA ENYINNAYA CHINMA ABSTRACT The processing and acceptability of fried cassava balls ("Akara-akpu") supplemented with melon and soybean flours were studied. Cassava flour, defatted soybean flour and cassava mash were produced. Some functional and chemical properties of the flours were determined. Akara-akpu prepared from 100% cassava mash served as control; 100% cassava flour, 80% cassava flour + 20% defatted soybean and 70% cassava flour + 30% defatted melon flour were prepared. Akara-akpu balls were subjected to chemical and physical analyses. Akara-akpu prepared from composite flour blends had higher protein, fat, ash and energy value than Akara-akpu from 100% cassava mash. The cyanide content and degree of starch gelatinization of Akara-akpu prepared from 100% cassava mash (control) were higher than Akara-akpu prepared from cassava mash plus composite flour blends. There was a significant difference (P , 0.05) in weight and yield between Akara-akpu prepared from 100% cassava mash (control) and cassava mash plus composite flour blends. There was no significant difference (P , 0.05) in volume between Akara-akpu made from control sample and those cassava plus composite flour blends. [source] HEAT TRANSFER TO CANNED PARTICULATES IN HIGH-VISCOSITY NEWTONIAN FLUIDS DURING AGITATION PROCESSINGJOURNAL OF FOOD PROCESSING AND PRESERVATION, Issue 6 2006YANG MENG ABSTRACT Heat transfer to canned particulate-laden Newtonian high-viscous fluids (Nylon particles suspended in aqueous glycerin solution [40, 60, 80, 90 and 100%, v/v] and motor oil [85W140]) during end-over-end rotation was studied in a pilot-scale, full water-immersion single-cage rotary retort. Computations of conventional fluid-to-particle heat transfer coefficient (hfp) and overall heat transfer coefficient (U) were successful with multiple particles for an entire range of viscosity, but the predicted particle lethality was underestimated. With a single particle in the can, hfpand U calculations were successful only for low-viscosity fluids (40 and 60% glycerin solutions), but again resulted in underestimation of particle lethality. Apparent heat transfer coefficients (hap) between retort and particle surface and apparent overall heat transfer coefficient (Ua) were also evaluated, and this methodology worked well for all cases. Further, the particle lethality predicted using hap better matched the measured values. With a single particle in the can, the associated hap was significantly (P < 0.05) influenced by rotation speed, retort temperature, liquid viscosity, particle material and can size. Ua was significantly (P < 0.05) influenced by rotation speed and liquid viscosity. The effects of headspace, radius of rotation and particle size were not significant (P > 0.05) on hap and Ua values. [source] PROCESSING OF FOXTAIL MILLET FOR IMPROVED NUTRIENT AVAILABILITYJOURNAL OF FOOD PROCESSING AND PRESERVATION, Issue 3 2006VITHAL DEORAO PAWAR ABSTRACT Foxtail millet grains were soaked in distilled water (1:5, w/v) for 12 h at room temperature, dehulled; dehulled and soaked; and dehulled, soaked and cooked in distilled water (1:3, w/v), and the effects of removal of polyphenols and phytate on the in vitro protein digestibility (IVPD) and availability of iron and zinc were measured. The results showed that polyphenols and phytate were decreased significantly up to 50.92 and 49.89%, respectively. The IVPD, however, increased up to 38.71%. The iron and zinc contents decreased up to 18.79 and 18.61%, respectively, but the ionizable iron and zinc were increased up to 55.45 and 80.18%, respectively. This indicated the suitability of simple processing techniques for improvement of availability of nutrients from foxtail millet. [source] DYNAMIC MODELING OF RETORT PROCESSING USING NEURAL NETWORKSJOURNAL OF FOOD PROCESSING AND PRESERVATION, Issue 2 2002C. R. CHEN ABSTRACT Two neural network approaches , a moving-window and hybrid neural network , which combine neural network with polynomial regression models, were used for modeling F(t) and Qv(t) dynamic functions under constant retort temperature processing. The dynamic functions involved six variables: retort temperature (116,132C), thermal diffusivity (1.5,2.3 × 10,7m2/s), can radius (40,61 mm), can height (40,61 mm), and quality kinetic parameters z (15,39C) and D (150,250 min). A computer simulation designed for process calculations of food thermal processing systems was used to provide the fundamental data for training and generalization of ANN models. Training data and testing data were constructed by both second order central composite design and orthogonal array, respectively. The optimal configurations of ANN models were obtained by varying the number of hidden layers, number of neurons in hidden layer and learning runs, and a combination of learning rules and transfer function. Results demonstrated that both neural network models well described the F(t) and Qv(t) dynamic functions, but moving-window network had better modeling performance than the hybrid ANN models. By comparison of the configuration parameters, moving-window ANN models required more neurons in the hidden layer and more learning runs for training than the hybrid ANN models. [source] PHYSICO-CHEMICAL ANALYSES, SENSORY EVALUATION AND POTENTIAL OF MINIMAL PROCESSING OF PEJIBAYE (BACTRIS GASIPAES) COMPARED TO MASCARENES PALMSJOURNAL OF FOOD QUALITY, Issue 2010J. JOAS ABSTRACT A palm species native of South America, pejibaye (Bactris gasipaes), was recently introduced in Reunion Island in an attempt to diversify its agriculture. Morphological analyses highlighted the agronomic advantages of pejibaye including a high weight-to-harvest-date ratio compared to three mascarenes palm species. Sensory analyses by a trained panel allowed the elaboration of sensory profiles of the four palms tested. Ranking test done by 120 consumers revealed that pejibaye was preferred to the Mascarenes palms at the 5% level of significance and triangle test showed that Acanthophoenix rubra (red palm), the most cultivated species for the local market, was significantly different from pejibaje at the 1% level. Phenolic profiles revealed that pejibaye differed from the other species by a peak absorbing at 272 nm and weak polyphenol oxidase activities. As no browning reaction was observed in fresh cut pejibaye, this palm could be used for minimal processing (local and export market). PRACTICAL APPLICATIONS Sensorial characteristics of fresh hearts of palm are different of those of canned heart of palm, and fresh heart palms are generally preferred by consumers. However, the marketing of fresh palm is limited by the high level of oxidation of most of palm species. The high stability of pejibaye after cutting and its slow rate of oxidation offer the possibility of minimal processing, without special additives. So the packaging in wrapped trays of this palm, cut and stored at low temperature opens up new perspectives, ensuring sensorial quality of a "fresh" product with a shelf life allowing a controlled management of market supply. [source] EFFECT OF COMBINED UNDERWATER PROCESSING AND MILD PRECUT HEAT TREATMENT ON THE SENSORY QUALITY AND STORAGE OF FRESH-CUT CANTALOUPE MELONJOURNAL OF FOOD QUALITY, Issue 4 2010KAREN L. BETT-GARBER ABSTRACT Improvement of storage quality of fresh-cut cantaloupe using a combination precut heat treatment and a modified underwater cutting treatment was determined. Eating quality was evaluated using descriptive sensory analysis, and fruit integrity was measured with respiration, cell leakage and product weight loss. Treatments included (1) control (no treatment); (2) making the first longitudinal cut underwater; (3) mild precut heat treatment in a water bath at 60C for 60 min; and (4) combination of precut heat treatment and the underwater cutting methods. Precut heating and processing underwater resulted in more intense fruity/melon flavor compared to conventional processed fresh-cut fruit. Reduced electrolyte leakage and enhanced membrane integrity were observed in all three experimental treatments, as evidenced by lower conductivity measurements. The underwater cut and combined treatments significantly reduced respiration during fresh-cut storage, reflecting less physical stress and membrane damage. Weight loss was not significantly affected by any treatment during fresh-cut storage. PRACTICAL APPLICATIONS There is a steady increase in the consumption of fresh-cut produce. To enhance the storage quality of fresh-cut cantaloupe melon, two minimal processing techniques were examined separately and combined. The methods are mild heat treatment of the whole melon at 60C for 60 min then cooling to 4C for 24 h, cutting the cantaloupe in half and removing the seeds while submerged in a calcium chloride and water solution, and the combination of the two treatments. These methods are simple and can be utilized by small or large processors to maintain sensory quality and fruit integrity during storage. [source] QUANTIFYING ADULTERATION IN ROAST COFFEE POWDERS BY DIGITAL IMAGE PROCESSINGJOURNAL OF FOOD QUALITY, Issue 2 2003EDSON E. SANO Pure arabica coffee and mixtures of coffee husks and straw, maize, brown sugar and soybean were produced in our laboratory as investigation materials. Red/Green/Blue (RGB) color composites, magnified twelve times, were generated using a Charge Coupled Device (CCD) camera connected to a stereo microscope and a personal computer with an image processing software package. The percent areas of the contaminants in each image were calculated by the Maximum Likelihood supervised classification technique. Best-fit equations relating weight percentage (g.kg -1) and the percent areas were obtained for each coffee contaminant. To test the method, 247 coffee samples of different amounts and types of adulterants were analyzed in the laboratory. The results showed that the new method developed can analyze precisely and quickly a large number of ground coffee powders. [source] PROCESSING AND QUALITY EVALUATION OF WHOLE CANNED ,DWARF' GOLDEN APPLES (SPONDIAS CYTHEREA)JOURNAL OF FOOD QUALITY, Issue 1 2002DAVID RAMSUNDAR ,Dwarf' golden apples (Spondias cytherea) were canned in sucrose syrup of either 30 d,Brix (L) or 40 d,Brix (H). Processing was either by hot filling (HF) of syrup at 92C in filled cans or by steam-exhausting (SE) of the filled cans at 85C for 12,14 min, followed by processing at 100C for 20 min (W20) or 30 min (W30). Sensory evaluation of commercial sterile products, SE-LW30 and SE-LW30 indicated there were no differences (P < 0.05) in appearance, color, taste, aroma and texture. Overall scores indicated that fruits in syrup were liked definitely to like slightly. Panelists indicated that they might or definitely will purchase the products. Fruits in 40 d,Brix syrup were firmer than in 30 d,Brix syrup. By week 8 of storage at 28,30C, pH was stable between 3.6,3.7, and ,cut-out'd,Brix of syrup for LW30 and HW30 products was 24.0 , 24.5 and 28.5, respectively. [source] FUNGI AND PATULIN IN APPLES AND THE ROLE OF PROCESSING ON PATULIN LEVELS IN JUICES: A STUDY ON NATURALLY CONTAMINATED APPLESJOURNAL OF FOOD SAFETY, Issue 2 2010JULIANE ELISA WELKE ABSTRACT The purpose of this study was to determine the predominant fungal species, including toxigenic strains, patulin levels in apples used for juice production and in produced juices. The possibility of use of apple highly contaminated with patulin to produce juice with lower patulin levels than the limit permitted by Codex Alimentarius was also checked. Sixteen lots of apples and juices were analyzed. The most prevalent fungal population was Penicillium spp. (93%) followed by the Aspergillus spp. (3.5%) and the Rhizopus spp. (3.5%). The mycoflora of apples was composed mainly of species that produce patulin. P. expansum was identified as the most frequently isolated species (66%). Species able to produce patulin were P. expansum and P. griseofulvum. Patulin levels in apples from cold storage ranged from 254.6 to 653.4 µg/kg. Apple juice processing caused average reduction of 95% in patulin levels. Patulin levels ranged from 14.3 to 46.7 µg/L in apple juices. In all samples were found patulin levels lower than the limit of 50 µg/L considered acceptable by the Codex Alimentarius Commission. PRACTICAL APPLICATIONS This study was performed to define the mycoflora of apples and patulin levels in apples that were used for juice production. This approach is useful to evaluate the quality of apples and the effect of processing on patulin to determine if the toxin level can be managed through postharvest procedures. Besides, information about patulin levels in juices is important to contribute for establishing national regulation. [source] EFFECT OF THERMOPHILIC LACTIC ACID BACTERIA ON THE FATE OF ENTEROBACTER SAKAZAKII DURING PROCESSING AND STORAGE OF PLAIN YOGURTJOURNAL OF FOOD SAFETY, Issue 2 2008REYAD R. SHAKER ABSTRACT Survival and growth of Enterobacter sakazakii during processing and storage of plain yogurt were investigated. Preheated rehydrated milk was inoculated with a cocktail culture of E. sakazakii (103 cfu/mL of milk) and/or with thermophilic yogurt starter culture of Lactobacillus delbrueckii ssp. bulgaricus and Streptococcus salivarius ssp. thermophilus. The inoculated milk was incubated at 40C for 5 h, then the samples were cooled and subsequently stored at 4C for up to 7 days. The results showed that E. sakazakii grew at an early stage of fermentation but declined at the end of the process. There was no significant difference between the populations of E. sakazakii in the presence or absence of lactic acid bacteria during the first 4 h of the incubation period but there was significant difference during the last hour of the incubation period. The populations of E. sakazakii decreased significantly during cooling and storage of yogurt (pH 4.2,4.7) compared with nonfermented milk samples at 4C. The presence of E. sakazakii did not have a significant effect on the growth of LAB during fermentation and storage of yogurt. The results obtained from this study indicate that the pH of yogurt and storage temperature were critical to the survival and growth of E. sakazakii in the manufacture of plain yogurt. PRACTICAL APPLICATIONS Enterobacter sakazakii prevalence in milk products and the production environment has been documented. The results obtained from this study may be of use to dairy producers to manufacture safe products using thermophilic lactic acid bacteria. These bacteria decreased the pH of milk in less than 5 h, resulting in E. sakazakii reduction. pH of yogurt during the fermentation process is a critical control point that should be monitored to produce safe products. [source] DICHOTOMY OF CORTICAL PAIN PROCESSINGPAIN MEDICINE, Issue 2 2002Article first published online: 4 JUL 200 Jahangir Maleki, Rollin M. Gallagher, Pain Medicine and Rehabilitation Center, MCP/Hahnemann School of Medicine Introduction: Functional MRI and PET studies of cortical pain processing indicate segregated pain pathways above the thalamus. Although experimental pain may result in multiple areas of altered cortical activity, it is postulated that thalamic pain fibers known as the lateral system, projecting to sensory cortex, serve to localize pain, whereas medial pathways projecting to limbic cortex, process affective aspects of pain. Case Study: A 27 y/o female, with left upper extremity pain and severe allodynia from Complex Regional Pain Syndrome, Type I (CRPS I / RSD), after receiving intra-pleural bupivacaine blocks developed an ipsilateral focal-onset secondary generalized tonic clonic seizure. This was followed by one hour of post-ictal confusion. Simultaneously she developed a dense left-sided motor and sensory deficit (Todd's palsy) with a motor deficit resolving in one day whereas a sensory deficit lasted 2 days. Throughout the duration of the sensory deficit she denied any left arm pain, although she continued to report the same intensity of pain, but now localized to her epigastric region. Interestingly, despite the lack of sensory perception on the left side, palpation of her left arm resulted in increased epigastric pain and suffering. Discussion: This case indicates a bifurcation of the pain pathway between the thalamus and cortex. Due to focal seizure activity, the sensory cortex (i.e. lateral system) was transiently rendered dysfunctional, during which time the continued presence of pain and allodynia without appropriate localization likely resulted from pain conduction, from the thalamus to functional limbic structures such as Cingulum (i.e. via the medial fibre system). Conclusion: This case report strongly supports the hypothesis of medial and lateral pain conducting fibers branching at the level of thalamus with medial sub-serving the emotional aspects of pain by projection to limbic cortex, whereas lateral fibres project to sensory cortex, primarily serving a localizing function. [source] MODULATION OF ATTENTION IN SEXUAL CUE PROCESSINGPSYCHOPHYSIOLOGY, Issue 2008Article first published online: 12 AUG 200 No abstract is available for this article. [source] EMOTIONAL PROCESSING IN PSYCHOPATHYPSYCHOPHYSIOLOGY, Issue 2006Article first published online: 7 AUG 200 No abstract is available for this article. [source] Time-Adaptive Lines for the Interactive Visualization of Unsteady Flow Data SetsCOMPUTER GRAPHICS FORUM, Issue 8 2009N. Cuntz I.3.3 [Computer Graphics]: Line and Curve Generation; I.3.1 [Computer Graphics]: Parallel Processing Abstract The quest for the ideal flow visualization reveals two major challenges: interactivity and accuracy. Interactivity stands for explorative capabilities and real-time control. Accuracy is a prerequisite for every professional visualization in order to provide a reliable base for analysis of a data set. Geometric flow visualization has a long tradition and comes in very different flavors. Among these, stream, path and streak lines are known to be very useful for both 2D and 3D flows. Despite their importance in practice, appropriate algorithms suited for contemporary hardware are rare. In particular, the adaptive construction of the different line types is not sufficiently studied. This study provides a profound representation and discussion of stream, path and streak lines. Two algorithms are proposed for efficiently and accurately generating these lines using modern graphics hardware. Each includes a scheme for adaptive time-stepping. The adaptivity for stream and path lines is achieved through a new processing idea we call ,selective transform feedback'. The adaptivity for streak lines combines adaptive time-stepping and a geometric refinement of the curve itself. Our visualization is applied, among others, to a data set representing a simulated typhoon. The storage as a set of 3D textures requires special attention. Both algorithms explicitly support this storage, as well as the use of precomputed adaptivity information. [source] Exposure Fusion: A Simple and Practical Alternative to High Dynamic Range PhotographyCOMPUTER GRAPHICS FORUM, Issue 1 2009T. Mertens I.4.8 [Image Processing]: Scene Analysis , Photometry, Sensor Fusion Abstract We propose a technique for fusing a bracketed exposure sequence into a high quality image, without converting to High dynamic range (HDR) first. Skipping the physically based HDR assembly step simplifies the acquisition pipeline. This avoids camera response curve calibration and is computationally efficient. It also allows for including flash images in the sequence. Our technique blends multiple exposures, guided by simple quality measures like saturation and contrast. This is done in a multiresolution fashion to account for the brightness variation in the sequence. The resulting image quality is comparable to existing tone mapping operators. [source] Guest Editorial: Selected Papers from the 18th Brazilian Symposium on Computer Graphics and Image Processing (SIBGRAPI' 2005)COMPUTER GRAPHICS FORUM, Issue 4 2006Maria Andréia No abstract is available for this article. [source] Differential Representations for Mesh ProcessingCOMPUTER GRAPHICS FORUM, Issue 4 2006Olga Sorkine Abstract Surface representation and processing is one of the key topics in computer graphics and geometric modeling, since it greatly affects the range of possible applications. In this paper we will present recent advances in geometry processing that are related to the Laplacian processing framework and differential representations. This framework is based on linear operators defined on polygonal meshes, and furnishes a variety of processing applications, such as shape approximation and compact representation, mesh editing, watermarking and morphing. The core of the framework is the definition of differential coordinates and new bases for efficient mesh geometry representation, based on the mesh Laplacian operator. [source] Second Symposium on Geometry ProcessingCOMPUTER GRAPHICS FORUM, Issue 4 200410 June 200, France No abstract is available for this article. [source] Symposium on Geometry ProcessingCOMPUTER GRAPHICS FORUM, Issue 1 200425 June 200, Aachen, Germany No abstract is available for this article. [source] Freeform Shape Representations for Efficient Geometry ProcessingCOMPUTER GRAPHICS FORUM, Issue 3 2003Leif Kobbelt The most important concepts for the handling and storage of freeform shapes in geometry processing applications are parametric representations and volumetric representations. Both have their specific advantages and drawbacks. While the algebraic complexity of volumetric representations is independent from the shape complexity, the domain of a parametric representation usually has to have the same structure as the surface itself (which sometimes makes it necessary to update the domain when the surface is modified). On the other hand, the topology of a parametrically defined surface can be controlled explicitly while in a volumetric representation, the surface topology can change accidentally during deformation. A volumetric representation reduces distance queries or inside/outside tests to mere function evaluations but the geodesic neighborhood relation between surface points is difficult to resolve. As a consequence, it seems promising to combine parametric and volumetric representations to effectively exploit both advantages. In this talk, a number of projects are presented and discussed in which such a combination leads to efficient and numerically stable algorithms for the solution of various geometry processing tasks. Applications include global error control for mesh decimation and smoothing, topology control for level-set surfaces, and shape modeling with unstructured point clouds. [source] Adaptive Logarithmic Mapping For Displaying High Contrast ScenesCOMPUTER GRAPHICS FORUM, Issue 3 2003F. Drago We propose a fast, high quality tone mapping technique to display high contrast images on devices with limited dynamicrange of luminance values. The method is based on logarithmic compression of luminance values, imitatingthe human response to light. A bias power function is introduced to adaptively vary logarithmic bases, resultingin good preservation of details and contrast. To improve contrast in dark areas, changes to the gamma correctionprocedure are proposed. Our adaptive logarithmic mapping technique is capable of producing perceptually tunedimages with high dynamic content and works at interactive speed. We demonstrate a successful application of ourtone mapping technique with a high dynamic range video player enabling to adjust optimal viewing conditions forany kind of display while taking into account user preference concerning brightness, contrast compression, anddetail reproduction. Categories and Subject Descriptors (according to ACM CCS): I.3.3 [Image Processing and Computer Vision]: Image Representation [source] Detecting Cycle Failures at Signalized Intersections Using Video Image ProcessingCOMPUTER-AIDED CIVIL AND INFRASTRUCTURE ENGINEERING, Issue 6 2006Jianyang Zheng Cycle failure detection is essential for identifying signal control problems at intersections. However, typical traffic sensors do not have the capability of capturing cycle failures. In this article, we introduce an algorithm for traffic signal cycle failure detection using video image processing. A cycle failure for a particular movement occurs when at least one vehicle must wait through more than one red light to complete the intended movement. The proposed cycle failure algorithm was implemented using Microsoft Visual C#. The system was tested with field data at different locations and time periods. The test results show that the algorithm works favorably: the system captured all the cycle failures and generated only three false alarms, which is approximately 0.9% of the total cycles tested. [source] Advanced Analysis of Steel Frames Using Parallel Processing and VectorizationCOMPUTER-AIDED CIVIL AND INFRASTRUCTURE ENGINEERING, Issue 5 2001C. M. Foley Advanced methods of analysis have shown promise in providing economical building structures through accurate evaluation of inelastic structural response. One method of advanced analysis is the plastic zone (distributed plasticity) method. Plastic zone analysis often has been deemed impractical due to computational expense. The purpose of this article is to illustrate applications of plastic zone analysis on large steel frames using advanced computational methods. To this end, a plastic zone analysis algorithm capable of using parallel processing and vector computation is discussed. Applicable measures for evaluating program speedup and efficiency on a Cray Y-MP C90 multiprocessor supercomputer are described. Program performance (speedup and efficiency) for parallel and vector processing is evaluated. Nonlinear response including postcritical branches of three large-scale fully restrained and partially restrained steel frameworks is computed using the proposed method. The results of the study indicate that advanced analysis of practical steel frames can be accomplished using plastic zone analysis methods and alternate computational strategies. [source] Information Processing and Firm-Internal Environment Contingencies: Performance Impact on Global New Product DevelopmentCREATIVITY AND INNOVATION MANAGEMENT, Issue 3 2010Elko Kleinschmidt Innovation in its essence is an information processing activity. Thus, a major factor impacting the success of new product development (NPD) programs, especially those responding to global markets, is the firm's ability to access, share and apply NPD information, which is often widely dispersed, functionally, geographically and culturally. To this end, an IT-communication strength is essential, one that is nested in an internal organizational environment that ensures its effective functioning. Using organizational information processing (OIP) theory as a framework, superior global NPD program performance is shown to result from an effective IT/Communication strength and the commitment components of the firm's internal environment, which are hypothesized to moderate this relationship. IT/Communication strength is identified in this study in terms of two components including the IT/Comm Infrastructure and IT/Comm Capability of the firm, whereas the moderating internal environment of the firm incorporates Resource Commitment and Senior Management Involvement. Data from a major empirical study of international NPD programs (382 SBUs) are used to develop and test this model. Based on a hierarchical regression analysis, the results are substantially supportive, with some unexpected findings. These shed light on the complex relationships of the firm's internal environment, OIP competency, and global NPD program performance. [source] Modeling Network Latency and Parallel Processing in Distributed Database DesignDECISION SCIENCES, Issue 4 2003Jesper M. Johansson ABSTRACT The design of responsive distributed database systems is a key concern for information systems managers. In high bandwidth networks latency and local processing are the most significant factors in query and update response time. Parallel processing can be used to minimize their effects, particularly if it is considered at design time. It is the judicious replication and placement of data within a network that enable parallelism to be effectively used. However, latency and parallel processing have largely been ignored in previous distributed database design approaches. We present a comprehensive approach to distributed database design that develops efficient combinations of data allocation and query processing strategies that take full advantage of parallelism. We use a genetic algorithm to enable the simultaneous optimization of data allocation and query processing strategies. We demonstrate that ignoring the effects of latency and parallelism at design time can result in the selection of unresponsive distributed database designs. [source] | |||||||||||||||||||||||||||||||||||||||||||||||||||||||