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11.
This article reports on the development of a hyperspectral imaging prototype for online evaluation of external and internal
quality of pickling cucumbers. The prototype consisted of a two-lane round belt conveyor, two illumination sources (one for
reflectance and one for transmittance), and a hyperspectral imaging unit. It had a novel feature of simultaneous imaging under
reflectance mode in the visible region (400–675 nm) and transmittance mode for the red and near-infrared region (Red-NIR)
(675–1000 nm). Reflectance information from the visible region was intended for evaluating the external characteristics of
cucumbers such as skin color, whereas transmittance information from Red-NIR was used for internal defect detection (i.e.,
hollow center). Additional features of the prototype included simultaneous acquisition of reflectance and transmittance from
calibration references that were installed in the system, to provide real-time, continuous corrections of individual hyperspectral
images from each sample. Methods and algorithms were developed of estimating cucumber fruit size and correcting the effect
of fruit size on transmittance measurements. The system was calibrated and evaluated for detecting the color, size, and internal
defect of pickling cucumbers. 相似文献
12.
Determining optimal wavebands using genetic algorithm for detection of internal insect infestation in tart cherry 总被引:2,自引:0,他引:2
Juan Xing Daniel Guyer Diwan Ariana Renfu Lu 《Sensing and Instrumentation for Food Quality and Safety》2008,2(3):161-167
This paper reports the results of waveband selection for detecting internal insect infestation in tart cherries as a precursor
to development of a dedicated multispectral vision system. A genetic algorithm (GA) approach was applied on hyperspectral
transmittance images (580–980 nm) and reflectance spectral data (590–1,550 nm) acquired from both intact and infested tart
cherries. The GA analysis indicates that the ability of using transmittance imaging approach for detecting internal insect
infestation in tart cherries would be limited. According to the GA analysis on the reflectance spectra, visible wavelengths
were of less importance than NIR wavelengths for the purpose of distinguishing intact cherries from infested ones. The PLSDA
results indicate that models built with three or four GA selected wavelength regions gave similar classification accuracy
to the model built with full wavelength region, which demonstrates the efficiency of the GA variable selection procedure.
However, due to the stochastic nature of the GA, the efficiency of using these wavebands in a multispectral vision system
needs to be verified in future work. 相似文献
13.
Ammonia borane (AB, NH3BH3) is considered to be a promising hydrogen storage material as it contains 19.6 wt% hydrogen. It is difficult, however, to release hydrogen from AB. Thermolysis, catalytic hydrolysis and heat generated by additional reactive mixtures are usually employed, but these methods have disadvantages that limit their use for portable applications. In this paper, we demonstrate a new approach to release hydrogen, which does not require any catalyst and produces relatively high hydrogen yield and environmentally benign byproducts. It involves nano-aluminum (nAl)/water combustion reaction, which provides heat for AB dehydrogenation and releases additional hydrogen from water. To facilitate higher H2 yield from thermolysis, as compared to hydrolysis, AB is spatially separated from the nAl/water mixture using a concentric cylindrical container. The effect of the container design on hydrogen generation is studied and optimized. This study also includes transient temperature and pressure measurements, and product characterization using mass spectrometer and 11B NMR. This approach provides H2 yield up to 9.5 wt% on material basis. Our experimental results and analysis show that a proposed power source based on this method is promising for portable electronic devices. 相似文献
14.
15.
Haiyan Cen Renfu Lu Diwan P. Ariana Fernando Mendoza 《Food and Bioprocess Technology》2014,7(6):1689-1700
Hyperspectral imaging is useful for detecting internal defects of pickling cucumbers. The technique, however, is not yet suitable for high-speed online implementation due to the challenges in analyzing large-scale hyperspectral images. This research aimed to select the optimal wavebands from the hyperspectral image data, so that they can be deployed in either a hyperspectral or multispectral imaging-based inspection system for the automatic detection of internal defects of pickling cucumbers. Hyperspectral reflectance (400–700 nm) and transmittance (700–1,000 nm) images were acquired, using an in-house developed hyperspectral imaging system running at two conveyor speeds of 85 and 165 mm/s, for 300 “Journey” pickling cucumbers before and after internal damage was induced by mechanical load. Minimum redundancy–maximum relevance (MRMR) was used for optimal wavebands selection, and the loadings of principal component analysis (PCA) were also applied for qualitatively identifying the important wavebands that are related to the specific features. Discriminant analysis with Mahalanobis distance classifier was performed for the two-class (i.e., normal and defective) and three-class (i.e., normal, slightly defective, and severely defective) classifications using the mean spectra and textural features (energy and variance) from the regions of interest in the spectral images at selected waveband ratios. The classification results based on MRMR wavebands selection were generally better than those from PCA-based classifications. The two-band ratio of 887/837 nm from MRMR gave the best overall classification results, with the accuracy of 95.1 and 94.2 % at the conveyor speeds of 85 and 165 mm/s, respectively, for the two-class classification. The highest classification accuracies for the three-class classification based on the optimal two-band ratio of 887/837 nm were 82.8 and 81.3 % at the conveyor speeds of 85 and 165 mm/s, respectively. The mean spectra-based classification achieved better results than the textural feature-based classification, except in the three-class classification for the higher conveyor speed. The overall classification accuracies for all selected waveband ratios at the low conveyor speed were slightly higher than those at the higher conveyor speed, since the low speed resulted in more scan lines, thus higher spatial resolution hyperspectral images. The identified two-band ratio of 887/837 nm in transmittance mode could be applied for fast real-time internal defect detection of pickling cucumbers. 相似文献
16.
LA Ahrens SH Aronson PL Connolly BG Gibbard MJ Murtagh SJ Murtagh S Terada DH White JL Callas D Cutts JS Hoftun M Diwan RE Lanou T Shinkawa Y Kurihara K Amako S Kabe Y Nagashima Y Suzuki S Tatsumi Y Yamaguchi K Abe EW Beier DC Doughty LS Durkin SM Heagy M Hurley AK Mann FM Newcomer HH Williams T York D Hedin MD Marx E Stern 《Canadian Metallurgical Quarterly》1987,35(3):785-809
17.
Singh V.K. Diwan A.A. 《Very Large Scale Integration (VLSI) Systems, IEEE Transactions on》1993,1(4):441-445
A heuristic for finding common subexpressions of given Boolean functions based on Shannon-type factoring is proposed. This heuristic limits the search space considerably by applying a top-down approach in which synthesis of a Boolean network flows from the primary outputs to the primary inputs. The common subexpressions and their complements in N variables are extracted before common subexpressions and their complements in (N-1) variables. This decomposition of the network depends on a permutation of Boolean variables and has a polynomial complexity for restricted extraction of complements. A multilevel logic optimization system, MULTI, has been implemented using this heuristic. Good results on several benchmark circuits show its effectiveness 相似文献
18.
V Amin AK Patwari G Kumar VK Anand N Diwan S Peshin 《Canadian Metallurgical Quarterly》1995,32(7):755-761
Clinical profile of cholera was studied in children attending Diarrhea Training and Treatment Unit from January-December 1993. Out of a total 8714 cases of acute watery diarrhea, 64 children (0.7%) were suspected to have cholera on the basis of acute onset loose water/rice watery stools, high purge rate with or without excessive vomiting and/or severe dehydration. Stool culture was positive for cholera in 33 cases (51.6%). All the isolates were V. cholerae 01 biotype El Tor serotype Ogawa. Sixty four per cent of stool culture positive cases were below 5 years of age. The results assume importance because out of 28 children < 2 years with clinical suspicion of cholera, 11 cases (39.3%) were culture positive for V. cholerae, youngest child being 3 months old. Comparison of various parameters revealed that presence of vomiting > 4 episodes/ day (p < 0.005), frequency of stools >12/24 hours (p <0.002), rice watery stools (p < 0.01) and presence of severe dehydration (p < 0.01) were significant parameters associated with positive stool culture. Beside examination of stool sample by hanging drop method was an excellent diagnostic tool (p < 0.001) with a sensitivity of 51.5%, specificity 100% and positive predictive value of 100%. The isolates of V. cholerae were susceptible to furazolidone, cephelexin, nalidixic acid, norfloxacin and gentamicin. Our observations indicate that cholera is not uncommon in infants and young children. Like children in the older age group, acute onset diarrhea with watery/rice watery stools and high purge rate with or without excessive vomiting and/or rapid development of severe dehydration should arouse suspicion of cholera in younger children also. They should be investigated for cholera even in non-endemic areas and in the absence of cholera outbreaks. 相似文献
19.
P.K. Diwan Neetu S. Kumar 《Nuclear instruments & methods in physics research. Section B, Beam interactions with materials and atoms》2010,268(23):3523-3525
Statistical variations in energy loss for Li, C and O ions in thick Kapton polymeric foils have been measured. These measured variations have been compared with the corresponding computed values based on modified Bethe-Livingston formulation, with the aim to ascertain the validity of this formulation. The study is quite important for the calibration and resolution of polymeric track detectors. 相似文献
20.
Ganga Modi Naidu Vegi Ramakrishna Sistla Palaniappan Srinivasan Sashidhar Rao Beedu Roop K Khar Prakash V Diwan 《Journal of the science of food and agriculture》2009,89(8):1271-1276
BACKGROUND: Natural polymers are widely used as emulsifying agents in the food and pharmaceutical industries because of their low cost, biocompatibility and non‐toxic nature. In the present study, emulsifying properties of the novel natural biopolymer gum kondagogu (GKG) were investigated. GKG solutions of different concentrations (0.1–0.6% w/v) were prepared in water and emulsified with liquid paraffin oil (40% v/v) in a high‐speed homogeniser. Flow properties of the emulsions were measured using a rheometer. Emulsion stability and droplet size distribution were determined by visual observation, photomicrography and laser‐scattering particle size distribution analysis. RESULTS: The emulsions prepared with GKG showed pseudoplastic behaviour. The size of oil droplets and the viscosity of emulsions at concentrations of 0.4–0.6% w/v showed little change over time (up to 30 days), indicating that the emulsions were stable. Measurements of the zeta potential of emulsions adjusted to different pH, with and without added electrolyte, showed that the stabilisation of emulsions with GKG was due to mutual repulsion between electrical double layers of particles and adsorption of macromolecules on oil droplets. CONCLUSION: The results of this experimental investigation show that GKG is a good emulsifying agent even at low concentrations, with many potential applications in the food and pharmaceutical industries. Copyright © 2009 Society of Chemical Industry 相似文献