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Sample records for plastic petri dish

  1. Gods, Germs, and Petri Dishes: Toward a Nonsecular Medical Anthropology.

    Science.gov (United States)

    Roberts, Elizabeth F S

    2016-01-01

    This commentary calls on medical anthropology to become programmatically non-secular. Despite recent anthropological critiques of secularity, within and outside of anthropology, most contemporary medical anthropologists continue to leave deities and religiosity out of their examinations of healing practices, especially in their accounts of biomedicine. Through a critical, relational constructionist lens, which traces how all entities are both constructed and real, a non-secular medical anthropology would insist that when deities are part of medical practice, they are integral to analysis. Importantly then, within the symmetrical nature of this same constructionist lens, biomedical entities like germs and petri dishes need to be accounted for just as much as deities.

  2. Stamped Petri dishes for 3D cell culture and drug testing

    NARCIS (Netherlands)

    Sridhar, Adithya; de Boer, Hans L.; van den Berg, Albert; le Gac, Severine

    2013-01-01

    We report here an experimentation platform directly made in a commercially available Petri dish for large-scale production of uniformly sized microtissues and their in situ characterization using both conventional microscopy and a scanning probe technique. The platform is realized by hot embossing m

  3. Temperature gradients drive radial fluid flow in Petri dishes and multiwell plates.

    Science.gov (United States)

    Lindsay, Stephen M; Yin, John

    2016-06-01

    Liquid in a Petri dish spontaneously circulates in a radial pattern, even when the dish is at rest. These fluid flows have been observed and utilized for biological research, but their origins have not been well-studied. Here we used particle-tracking to measure velocities of radial fluid flows, which are shown to be linked to evaporation. Infrared thermal imaging was used to identify thermal gradients at the air-liquid interface and at the bottom of the dish. Two-color ratiometric fluorescence confocal imaging was used to measure thermal gradients in the vertical direction within the fluid. A finite-element model of the fluid, incorporating the measured temperature profiles, shows that buoyancy forces are sufficient to produce flows consistent with the measured particle velocity results. Such flows may arise in other dish or plate formats, and may impact biological research in positive or negative ways.

  4. It is Time for a Change:Petri Dishes Weaken Cells

    Institute of Scientific and Technical Information of China (English)

    Andrei P.Sommer; Mike Kh.Haddad; Hans-Joerg Fecht

    2012-01-01

    We wish to draw the attention to a potential deficiency in the biocompatibility of polystyrene cell culturc dishes which is caused by a softening of the material under relevant culture conditions.The finding confirms the central hypothesis of our previous model study.In it we assumed a local increase in pH at the interface between the hydrophilic polymer and liquid.The finding is of considerable biological interest.Polystyrene tissue culture dishes are now in use for 50 years.To the best of our knowledge their biocompatibility has never been challenged.Here we report the first experimental proof that exposure to water softens the surface of polystyrene Petri dishes.We expect that our results will stimulate the development ofa new generation of cell culture devices,including Petri dishes and culture flasks,and the establishment of improved biomimetic settings for tissuc engineering and stem cell research.New non-swelling biomaterials or nanocoatings designed to reduce the swelling of polymer culture dishes could improve cell performance.The need for further study is clear.

  5. Nano Petri dishes: a new polystyrene platform for studying cell-nanoengineered surface interactions

    Science.gov (United States)

    Cha, Kyoung Je; Na, Moon-Hee; Kim, Hyung Woo; Kim, Dong Sung

    2014-05-01

    In this study, we fabricated and fully characterized a new type of polystyrene (PS) cell-culture platform containing nanoengineered surfaces (NES), referred to as a nano Petri dish, which can be used at the transition stage of basic cell-NES interaction studies for clinical applications. Nano-injection molding in this study was used for the mass production of the nano Petri dish having nanopore arrays. The effects of processing parameters of the injection molding on the replication quality of the nanopore arrays were quantitatively evaluated by means of design of experiments based on the Taguchi method. This allowed efficient and reliable cell culture studies by providing large numbers of the same dishes, in addition to removing the fixation step of the NES plates inside the cell-culture container. Physical, chemical and mechanical properties of the NES, as well as cell behavior including attachment and proliferation of human osteosarcoma MG-63 cells on the NES, were then characterized, with and without the oxygen plasma surface treatment.

  6. Automatic Evaluation of Colonies Growth rate of Yeasts incubated in Petri dishes using Mobile Platform

    Directory of Open Access Journals (Sweden)

    Alecsander Pereira Martins

    2015-10-01

    Full Text Available This paper proposes an automatic method based on computer vision implemented in mobile platform capable of monitoring the growth of microbial colonies incubated in Petri dishes. The developed optimized image processing algorithm performs this task without human intervention from images of colonies of the microorganism in different evolution phases. The contribution of this paper is the development of a fast and robust mobile tool to assist bioprocess experts in monitoring the growth of colonies without using the conventional error prone evaluation techniques. The obtained results successfully demonstrated dimensional alterations in colonies in a faster and more precise fashion when compared with the conventional method, with the additional advantage of versatility in producing reliable estimation of the growth rates with higher statistical significance.

  7. Metabolic Profiling Directly from the Petri Dish Using Nanospray Desorption Electrospray Ionization Imaging Mass Spectrometry

    Energy Technology Data Exchange (ETDEWEB)

    Watrous, Jeramie D.; Roach, Patrick J.; Heath, Brandi S.; Alexandrov, Theodore; Laskin, Julia; Dorrestein, Pieter C.

    2013-11-05

    Understanding molecular interaction pathways in complex biological systems constitutes a treasure trove of knowledge that might facilitate the specific, chemical manipulation of the countless microbiological systems that occur throughout our world. However, there is a lack of methodologies that allow the direct investigation of chemical gradients and interactions in living biological systems, in real time. Here, we report the use of nanospray desorption electrospray ionization (nanoDESI) imaging mass spectrometry for in vivo metabolic profiling of living bacterial colonies directly from the Petri dish with absolutely no sample preparation needed. Using this technique, we investigated single colonies of Shewanella oneidensis MR-1, Bacillus subtilis 3610, and Streptomyces coelicolor A3(2) as well as a mixed biofilm of S. oneidensis MR-1 and B. subtilis 3610. Data from B. subtilis 3610 and S. coelicolor A3(2) provided a means of validation for the method while data from S. oneidensis MR-1 and the mixed biofilm showed a wide range of compounds that this bacterium uses for the dissimilatory reduction of extracellular metal oxides, including riboflavin, iron-bound heme and heme biosynthetic intermediates, and the siderophore putrebactin.

  8. Label-free interdigitated microelectrode based biosensors for bacterial biofilm growth monitoring using Petri dishes.

    Science.gov (United States)

    Paredes, Jacobo; Becerro, Sheila; Arana, Sergio

    2014-05-01

    Impedance microbiology (IM) is a known technique that has been applied during the last decades to detect the presence of microorganisms in real samples in different fields: food industry, healthcare, environment, etc. Bacterial biofilms however have not been so far studied despite the fact that they are the most common microbiological formation and that they present resistance to antimicrobial agents. In situ early detection of bacterial biofilm is still a challenge nowadays that causes huge impact in many different scenarios. The ability to detect biofilm generation early will allow better and more efficient treatments preventing high costs and important problems. In this work a new performance of this technique with interdigitated microelectrode sensors (IDE) is proposed. A specific culturing setup where the sensors have been integrated in Petri Dishes has been developed. From the results it can be highlighted that low frequencies are more sensitive for detection than higher ones. The results achieved record variations of approximately 40% in the equivalent serial resistance after 10h of culture. Electrical models have been successfully simulated to find the electrical behavior of the development of biofilms. Variations in both the capacitance and resistance were recorded during the growth of the microbes.

  9. An objective method to measure cell survival by computer-assisted image processing of numeric images of Petri dishes

    Energy Technology Data Exchange (ETDEWEB)

    Biston, Marie-Claude [Equipe d' Accueil no 2941 ' Rayonnement Synchrotron et Recherche Medicale' , Unite IRM, CHU, BP 217, F-38043 Grenoble Cedex 09 (France); Corde, Stephanie [Equipe d' Accueil no 2941 ' Rayonnement Synchrotron et Recherche Medicale' , Unite IRM, CHU, BP 217, F-38043 Grenoble Cedex 09 (France); Camus, Emmanuel [Samba Technologies, ZIRST 53, chemin du Vieux Chene 38240 Meylan (France); Marti-Battle, Ramon [Samba Technologies, ZIRST 53, chemin du Vieux Chene 38240 Meylan (France); Esteve, Francois [Equipe d' Accueil no 2941 ' Rayonnement Synchrotron et Recherche Medicale' , Unite IRM, CHU, BP 217, F-38043 Grenoble Cedex 09 (France); Balosso, Jacques [Equipe d' Accueil no 2941 ' Rayonnement Synchrotron et Recherche Medicale' , Unite IRM, CHU, BP 217, F-38043 Grenoble Cedex 09 (France)

    2003-06-07

    This work establishes an objective method to measure cell clonogenic survival by computer-assisted image processing using images of cell cultures fixed and stained in Petri dishes. The procedure, developed by Samba Technologies, consists of acquiring Petri dish pictures with a desktop scanner and analysing them by computer, using algorithms based on the 'top hat' filter. The results from the automated count for the cell line SQ20B are compared with those found by two observers, before and after normalization of the counting. After normalization, the shape of the survival curves of the 'manual' counting of the Petri dishes shows a good correlation between both observers. The software enables the small visible differences in count between observers to be eliminated. The comparison between the absolute number of colonies shows an increased difference between the two manual scorings that can be as great as 67 colonies, whereas the difference between the two automated counts is never greater than 8 colonies. These results demonstrate that the 'manual' count is inter- and intra-observer variable, whereas the automatic count performs reproducible cell colony counts, thereby minimizing user-generated bias. The large amount of data produced also gives information about cell and colony characteristics. Thus, this computer-assisted method has considerably improved the reliability of our statistical results.

  10. Field measurements of dry deposition to spruce foliage and petri dishes in the black forest, F.R.G.

    Science.gov (United States)

    Shanley, James B.

    Dry deposition fluxes of Ca 2+, Mg 2+ , K +, Mn 2+, Pb 2+ and SO 2-4 to spruce foliage and petri dishes were measured in two high-elevation sites ( > 900 m) in the southern Black Forest, F.R.G., during 12 periods (2-7 days, each) from mid-September to mid-November, 1983, In situ extraction of deposited material from small spruce branches allowed repeated use of the same foliar collecting surfaces for a direct comparison of deposition between periods. Fluxes were corrected for leaching of internally cycled constituents using factors determined from serial extraction experiments. The ratio of flux to petri dishes vs foliage ( P/F) was > 1.0 for Ca 2+, Pb 2+ and SO 2-4, and somewhat < 1.0 but more constant for Mg 2+ . Temporal variations in dry deposition fluxes at an exposed site near the industrialized Rhine Valley correlated with variations in total air particulate concentrations at a nearby air quality station. Deposition rates were comparable in magnitude but different in temporal pattern at a remote site in the Black Forest interior. Fluxes at each site reached a minimum during the period of 4-9 November when a regional air inversion confined pollutants to the Rhine Valley below the study sites. High fluxes accompanied the inversion break-up.

  11. Analysis of ewe’s milk by FT Near Infrared spectroscopy: measurement of samples on Petri dishes in reflectance mode

    Directory of Open Access Journals (Sweden)

    Květoslava Šustová

    2006-01-01

    Full Text Available Our work deals with a possibility of determination of basic composition (dry matter, fat, protein, casein, lactose and urea nitrogen of ewe’s milk and colostrum by FT NIR spectroscopy. Samples of milk were warmed to 40 °C, agitated, cooled to 20 °C, transferred into Petri dishes and analysed by reference methods and by FT NIR in reflectance mode. The measured area was spaced by a metallic mirror. Statistically significant differences between the reference values and the calculated values of NIR were not found (p=0.05. Results of calibration for ewe’s milk determined the highest correlation coefficients: dry matter 0.983, fat 0.989, true protein 0.997, casein 0.977, lactose 0.980 and urea nitrogen 0.973. The study showed that NIRS method, when samples of milk are measured on Petri dishes, is a useful technique for the prediction of dry matter, fat, protein and casein in ewe’s milk.

  12. Hydrophilic group formation and cell culturing on polystyrene Petri-dish modified by ion-assisted reaction

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Ki-Hwan E-mail: hama@kist.re.kr; Cho, Jun-Sik; Choi, Doo-Jin; Koh, Seok-Keun

    2001-04-01

    Polystyrene (PS) Petri-dishes were modified by an ion-assisted reaction (IAR) to improve wettability and to supply a suitable surface for cell culturing. Low energy Ar{sup +} ions with 1000 eV were irradiated on the surface of PS in oxygen gas environment. Water contact angles of PS were not reduced much by ion irradiation without oxygen gas and had a value of 40 deg. In the case of ion irradiation with flowing oxygen gas, however, the water contact angles were dropped significantly from 73 deg. to 19 deg. X-ray photoelectron spectroscopy analysis showed that the hydrophilic groups were formed on the surface of PS by a chemical reaction between unstable chains induced by ion irradiation and the oxygen gas. Newly formed hydrophilic groups were identified as -(C-O)-, -(C=O)- and -(C=O)-O- bonds. The influence of the surface modification on growth of the rat pheochromocytoma (PC12) cells was investigated. The IAR-treated PS surfaces showed enhanced attachment and growth in PC12 cell culture test.

  13. Development of a plastic injection molding training system using Petri nets and virtual reality

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    In this study, Virtual Reality (VR)-based plastic injection molding training system (VPIMTS), which can be modeled as an integrated system with a task planning module, an intelligent instruction module, a simulation module, and virtual environment (VE) module, was developed. Presented in this paper are an architecture of VPIMTS, a practical knowledge modelling approach for modelling the training scenarios of the system by using Petri nets formalism and key techniques (FEM, injection molding procedure modelling) which have been developed independently. The utilization of the Petri net model realized the environment where the trainee can behave freely, and also made it possible to equip the system with the function of showing the next action of the trainee whenever he wants. The overall system is a powerful approach for highly improving the trainee's comprehension and injection molding study-efficiency by building digital, intelligent, knowledgeable, and visual aids.

  14. Effects of Indole-3-Acetic Acid on Germination in Lead Polluted Petri Dish of Citrullus lanatus (Thunberg Matsumura and Nakai, Cucurbitaceae

    Directory of Open Access Journals (Sweden)

    Matthew Chidozie Ogwu

    2015-12-01

    Full Text Available Watermelon, Citrullus lanatus (Thunberg Matsumura and Nakai is a tropical fruit vegetable. Indole-3-acetic acid (IAA is a popular phytohormone while lead (Pb is a common environmental pollutant in urban and sub-urban centers. C. lanatus were obtained from Benin City with a view to study the effects of IAA on their germination in Pb polluted environment.  Germination percentage without IAA and Pb treatment in petri dish was significant after ten days. Hastened germination was observed when IAA and lead were used. About 100 % germination was recorded after seven days. This suggests that water melon seeds can initiate growth even in lead polluted environment. Optimum level of 5 ppm IAA with the different levels of lead treatments may be recommended. Most important was that higher concentrations of Pb in the control (without IAA did not inhibit seedling shoot nor root growth. Longest seedling shoot length (cm was 10.33 ± 1.24 and 12.13 ± 2.06 on the seventh and eighth day respectively with the combined treatment levels of 1 ppm IAA and 15 ppm Pb. On the ninth day, 15.27 ± 0.96 was obtained from 1 ppm IAA and 20 ppm Pb. Longest seedling root length (cm values were recorded from the combined treatment levels of 0 ppm IAA and 10 ppm Pb for the seventh (9.10 ± 0.47 and ninth (10.37 ± 1.81 day respectively and 0 ppm and 15 ppm Pb on the eighth (9.37 ± 0.84 day. Significant means were also obtained with the treatment level of 0 and 20 ppm IAA. This present study suggest the germination of C. lanatus under Pb polluted environment may be rescued with optimum IAA.

  15. Application of rapid petri-dish in the detection of Salmonella spp. in food%沙门氏菌快速检测板在食品检测中的应用研究

    Institute of Scientific and Technical Information of China (English)

    肖剑; 陈娟丽; 张彬彬; 陈楷; 孙霞; 蒋佳希

    2016-01-01

    ABSTRACT:Objective To research the application value of rapid petri-dish in the detection of Salmonella spp. in food. Methods The sensitivity, specificity, anti-interference, false positive rate, false negative rate and accuracy of Salmonella spp. petri-dish were studied by using standard strains as specimen and comparison with GB 4789.4-2010. Meanwhile, the significant difference of positive rate was analyzed by the chi-square. Results The minimum detection limit of Salmonella spp. rapid petri-dish could reach 100 CFU/mL. The sensitivity of Salmonella spp. petri-dish was 100%, and the false negative rate was 0. The specificity was 92%, and the false positive rate was 8%. The accuracy rate was 95%, and the chi-square (Χ2) was 0.5. The results showed that all parameters conformed to the requirements of the test. Conclusion It is feasible to detect the Salmonella spp. with the rapid plate as a rapid screening method in the field of food safety, which is sensitivity, specificity, accuracy and simplicity.%目的:研究沙门氏菌快速检测板在食品检测中的应用。方法以标准菌株为测试样本,参照 GB 4789.4-2010验证沙门氏菌快速检测板的灵敏度、特异性、假阳性率、假阴性率、准确度,同时利用卡方检验分析阳性率显著性差异。结果沙门氏菌快速检测板最低检测限能达到100 CFU/mL,灵敏度为100%,不存在假阴性,特异性为92%,假阳性率为8%,准确度为95%,显著性差异卡方值卡Χ2为0.5,均达到定性方法验证的相关指标。结论沙门氏菌检测板技术方法具有快速准确、灵敏度高、操作简单的特点,可以作为一种快速筛查方法广泛运用在食品安全微生物检测领域。

  16. Preserving in Plastic.

    Science.gov (United States)

    Wahla, James

    1985-01-01

    Outlines steps for casting insects in permanent molds prepared from commercially available liquid plastic. Also describes dry mountings in glass, acrylic, and petri dishes. The rationale for specimen use, hints for producing quality results, purchasing information, and safety precautions are considered. (DH)

  17. Effects of irradiation distance on supply of reactive oxygen species to the bottom of a Petri dish filled with liquid by an atmospheric O{sub 2}/He plasma jet

    Energy Technology Data Exchange (ETDEWEB)

    Kawasaki, Toshiyuki, E-mail: kawasaki@nbu.ac.jp; Kusumegi, Shota; Kudo, Akihiro; Sakanoshita, Tomohiro; Tsurumaru, Takuya; Sato, Akihiro [Department of Mechanical and Electrical Engineering, Nippon Bunri University, Oita, Oita 870-0397 (Japan); Uchida, Giichiro [Joining and Welding Research Institute, Osaka University, Ibaraki, Osaka 567-0047 (Japan); Koga, Kazunori; Shiratani, Masaharu [Graduate School of Information Science and Electrical Engineering, Kyushu University, Fukuoka, Fukuoka 819-0395 (Japan)

    2016-05-07

    The impact of irradiation distances on plasma jet-induced specific effects on the supply of reactive oxygen species (ROS) to the bottom of a Petri dish filled with liquid was investigated using a KI-starch gel reagent that can be employed as a ROS indicator even in water. O{sub 3} exposure experiments without plasma irradiation were also performed to elucidate the specific effects of the plasma jet. Relative concentrations of ROS transported to the bottom were evaluated using absorbance measurements. The results indicated that ROS supply to the bottom is markedly enhanced by the plasma jet irradiation at shorter irradiation distances, whereas similar results could not be obtained for the O{sub 3} exposure. In these cases, the liquid mixing in the depth direction was also enhanced by the plasma jet irradiation only, and the supply of reactive atomic oxygen to the liquid surface was markedly increased as well.

  18. Contact petri dish in detection of Staphylococcus aureus and Escherichia coli on hands of blood collection staff%采用接触式培养皿法对采血人员手部金黄色葡萄球菌与大肠埃希菌的检测效果分析

    Institute of Scientific and Technical Information of China (English)

    赵安成

    2012-01-01

    OBJECTIVE To evaluate the effect of contact petri dish on the detection of Staphylococcus aureus and Escherichia coli in the hands of the blood collection staff. METHODS A total of 28 cases of blood collection staff were divided into two groups according to the disinfection methods before the puncture for the blood sampling. The contact petri dish group was taken with contact petri dish method, and the swab group was taken with the swab method. The number of the species of pathogens were determined by sampling, culture, colony counting, and identification culture medium for S. aureus and E. coli. RESULTS The blood collection staff in the contact petri dish group before the disinfection, with the total bacterial colony counts more than 30 CFU/30 cm2 , accounted for 50. 00% , significantly higher than 7. 13% of the swap group. The blood collection staff in the contact petri dish group after the disinfection, with the bacterial colony counts 21 - 30 CFU/30 cm2 , accounted for 14. 29% , there were no strains of pathogens detected in the swab group (P<0. 05) ; before and after disinfection, the volume of S. aureus and E. coli detected by the contact petri dish before and after the disinfections was significantly higher than that by the swab (P<0. 05). CONCLUSION The contact petri dish method is effective and simple in the detection of the total bacterial colonies counts of S. aureus and E. coli.%目的 评价接触式培养皿法对采血人员手部金黄色葡萄球菌与大肠埃希菌的检测效果.方法 将28名采血人员在穿刺采血之前的手部消毒前后,根据采取的消毒方式不同分为两组,其中接触式培养皿组采用接触式培养皿法,棉签擦拭组采用棉签擦拭法进行,分别取样、培养、菌落计数、用金黄色葡萄球菌和大肠埃希菌鉴别培养基鉴定该种类菌株数.结果 接触式培养皿法消毒前细菌总数>30 CFU/30 cm2的人数占50.00%,显著高于棉签擦拭法的7.13

  19. Understanding mobility in a social petri dish

    CERN Document Server

    Szell, Michael; Petri, Giovanni; Thurner, Stefan; Latora, Vito

    2011-01-01

    Despite the recent availability of large data sets on human movements, a full understanding of the rules governing motion within social systems is still missing, due to incomplete information on the socio-economic factors and to often limited spatio-temporal resolutions. Here we study an entire society of individuals, the players of an online-game, with complete information on their movements in a network-shaped universe and on their social and economic interactions. Such a "socio-economic laboratory" allows to unveil the intricate interplay of spatial constraints, social and economic factors, and patterns of mobility. We find that the motion of individuals is not only constrained by physical distances, but also strongly shaped by the presence of socio-economic areas. These regions can be recovered perfectly by community detection methods solely based on the measured human dynamics. Moreover, we uncover that long-term memory in the time-order of visited locations is the essential ingredient for modeling the t...

  20. Demonstrations of the Action and Reaction Law and the Energy Conservation Law Using Fine Spherical Plastic Beads

    Science.gov (United States)

    Khumaeni, A.; Tanaka, S.; Kobayashi, A.; Lee, Y. I.; Kurniawan, K. H.; Ishii, K.; Kagawa, K.

    2008-01-01

    Equipment for demonstrating Newton's third law and the energy conservation law in mechanics have successfully been constructed utilizing fine spherical plastic beads in place of metal ball bearings. To demonstrate Newton's third law, special magnetized Petri dishes were employed as objects, while to examine the energy conservation law, a…

  1. Fish Dishes.

    Science.gov (United States)

    Derby, Marie

    2003-01-01

    Describes an art project that was inspired by Greek pottery, specifically dishes shaped as fish. Explains that fourth-grade students drew a fish shape that was later used to create their clay version of the fish. Discusses how the students examined the pottery to make decisions about color and design. (CMK)

  2. Rigid collapsible dish structure

    Science.gov (United States)

    Palmer, William B. (Inventor); Giebler, Martin M. (Inventor)

    1982-01-01

    A collapsible dish structure composed of a plurality of rows of rigid radial petal assemblies concentric with the axis of the dish. The petal assemblies consist of a center petal and two side petals, the center petal hinged on an axis tangent to a circle concentric with the axis of the dish and the side petals hinged to the center petal at their mating edge. The center petal is foldable inwardly and the side petals rotate about their hinges such that the collapsed dish structure occupies a much smaller volume than the deployed dish. Means of controlling the shape of the dish to compensate for differential expansion of the deployed dish are also provided.

  3. Game Coloured Petri Nets

    DEFF Research Database (Denmark)

    Westergaard, Michael

    2006-01-01

    This paper introduces the notion of game coloured Petri nets. This allows the modeler to explicitly model what parts of the model comprise the modeled system and what parts are the environment of the modeled system. We give the formal definition of game coloured Petri nets, a means of reachability...... analysis of this net class, and an application of game coloured Petri nets to automatically generate easy-to-understand visualizations of the model by exploiting the knowledge that some parts of the model are not interesting from a visualization perspective (i.e. they are part of the environment...

  4. Game Coloured Petri Nets

    DEFF Research Database (Denmark)

    Westergaard, Michael

    2006-01-01

    This paper introduces the notion of game coloured Petri nets. This allows the modeler to explicitly model what parts of the model comprise the modeled system and what parts are the environment of the modeled system. We give the formal definition of game coloured Petri nets, a means of reachabilit......, and not controllable by the system itself, or they are part of the system itself and therefore we need not worry about them)....

  5. The effects of packaging method (vacuum pouch vs. plastic tray) on spoilage in a cook-chill pork-based dish kept under refrigeration.

    Science.gov (United States)

    Díaz, Pedro; Garrido, María Dolores; Bañón, Sancho

    2010-03-01

    The effects of two packaging methods on the spoilage of a cook-chill pork-based dish kept under refrigeration were studied. Raw pork cuts and pre-cooked tomato sauce were packed under vacuum "sous vide" in polyamide-polypropylene pouches (SV) or into translucent polypropylene trays under modified atmosphere (80% N(2)+20% CO(2)) and sealed with a top film (PT). Samples were cooked inside the pack at an oven temperature/time of 70 degrees C/7h, chilled at 3 degrees C and stored at 2 degrees C for up to 90days. Microbial (psychrotrophs, lactic-acid bacteria, Enterobacteriaceae, moulds and yeasts), physical-chemical (pH, water activity and total acidity) and sensory (colour, odour, flavour, texture and acceptance) parameters were determined. Heat penetration was faster in SV (2 degrees C/min) than in PT (1 degrees C/min) (core temperature). Both packaging methods were equally effective in protecting against microbial spoilage for 90 day at 2 degrees C. Minor counts were only detected for lactic-acid bacteria and anaerobic psychrotrophs in SV. No Enterobacteriaceae growth was found. Slight differences between SV and PT in pH and total acidity were observed. SV and PT had similar effects on the sensory preservation of the dishes. A gradual loss of acceptance of the cooked pork and tomato sauce was observed. Rancid flavour in PT and warmed-over-flavour in SV were noted in the final stages of storage. According to acceptance scores, the shelf-life of both SV and PT was 56 days at 2 degrees C. Both packaging methods can be used to manufacture sous vide meat-based dishes subsequently stored under refrigeration for catering use. Copyright 2009 Elsevier Ltd. All rights reserved.

  6. Parabolic Dish Stirling Module

    Science.gov (United States)

    Washom, B.

    1984-01-01

    The design, manufacture, and assembly of a commercially designed parabolic dish Stirling 25 kWe module is examined. The cost, expected performance, design uniquenesses, and future commercial potential of this module, which is regarded as the most technically advanced in the parabolic dish industry is discussed.

  7. Biological Petri Nets

    CERN Document Server

    Wingender, E

    2011-01-01

    It was suggested some years ago that Petri nets might be well suited to modeling metabolic networks, overcoming some of the limitations encountered by the use of systems employing ODEs (ordinary differential equations). Much work has been done since then which confirms this and demonstrates the usefulness of this concept for systems biology. Petri net technology is not only intuitively understood by scientists trained in the life sciences, it also has a robust mathematical foundation and provides the required degree of flexibility. As a result it appears to be a very promising approach to mode

  8. Coloured Petri Nets

    CERN Document Server

    Jensen, Kurt

    2009-01-01

    Coloured Petri Nets (CPN) is a graphical language for modelling and validating concurrent and distributed systems, and other systems in which concurrency plays a major role. This book introduces the constructs of the CPN modelling language and presents the related analysis methods. It provides a comprehensive road map for the practical use of CPN.

  9. High-level Petri Nets

    DEFF Research Database (Denmark)

    to their work can be found in the individual papers and in the available bibliographies of Petri nets, e.g., Stefan Dress et. al: Bibliography of Petri Nets. In: G. Rozenberg (ed.): Advances in Petri Nets 1987, Lecture Notes in Computer Science, vol. 266, Springer-Verlag 1987, 309-451. Updated versions...... of this bibliography will appear in Advances of Petri Nets with regular intervals. In the preparation of the book the editors have been assisted by an advisory board consisting of the following well-known Petri net researchers: M. Ajmone-Marsan, H.J. Genrich, C. Girault, W. Reisig, M. Silva and P.S. Thiagarajan...

  10. Modelling Inteligent Systems with Level Petri Nets

    Directory of Open Access Journals (Sweden)

    Corina BOCĂNEALĂ

    2008-12-01

    Full Text Available Level Petri Nets are formalism for modeling hierarchical multi-agent system. They are a Petri nets extension, allowing tokens to be nets themselves. This paper is inspired by two classes of level Petri nets: object Petri nets and nested Petri nets. We present some concepts from the artificial intelligence field and we use them to illustrate the modeling power of Petri nets with multi levels.

  11. Coloured Petri Nets

    DEFF Research Database (Denmark)

    Jensen, Kurt

    1991-01-01

    This paper describes how Coloured Petri Nets (CP-nets) have been developed — from being a promising theoretical model to being a full-fledged language for the design, specification, simulation, validation and implementation of large software systems (and other systems in which human beings and...... use of CP-nets — because it means that the function representation and the translations (which are a bit mathematically complex) no longer are parts of the basic definition of CP-nets. Instead they are parts of the invariant method (which anyway demands considerable mathematical skills...

  12. Linear Logic on Petri Nets

    DEFF Research Database (Denmark)

    Engberg, Uffe Henrik; Winskel, Glynn

    This article shows how individual Petri nets form models of Girard's intuitionistic linear logic. It explores questions of expressiveness and completeness of linear logic with respect to this interpretation. An aim is to use Petri nets to give an understanding of linear logic and give some apprai...

  13. A Small Universal Petri Net

    Directory of Open Access Journals (Sweden)

    Dmitry A. Zaitsev

    2013-09-01

    Full Text Available A universal deterministic inhibitor Petri net with 14 places, 29 transitions and 138 arcs was constructed via simulation of Neary and Woods' weakly universal Turing machine with 2 states and 4 symbols; the total time complexity is exponential in the running time of their weak machine. To simulate the blank words of the weakly universal Turing machine, a couple of dedicated transitions insert their codes when reaching edges of the working zone. To complete a chain of a given Petri net encoding to be executed by the universal Petri net, a translation of a bi-tag system into a Turing machine was constructed. The constructed Petri net is universal in the standard sense; a weaker form of universality for Petri nets was not introduced in this work.

  14. Annotating Coloured Petri Nets

    DEFF Research Database (Denmark)

    Lindstrøm, Bo; Wells, Lisa Marie

    2002-01-01

    Coloured Petri nets (CP-nets) can be used for several fundamentally different purposes like functional analysis, performance analysis, and visualisation. To be able to use the corresponding tool extensions and libraries it is sometimes necessary to include extra auxiliary information in the CP-ne...... a certain use of the CP-net. We define the semantics of annotations by describing a translation from a CP-net and the corresponding annotation layers to another CP-net where the annotations are an integrated part of the CP-net....... a method which makes it possible to associate auxiliary information, called annotations, with tokens without modifying the colour sets of the CP-net. Annotations are pieces of information that are not essential for determining the behaviour of the system being modelled, but are rather added to support...

  15. METHOD OF DISPLAYING AN EXECUTABLE BUSINESS PROCESS MODELS INTO PETRI NETS

    Directory of Open Access Journals (Sweden)

    Igor G. Fedorov

    2013-01-01

    Full Text Available Executable business process models, as well as programs, require evidence of a defect-free finish. The methods based on the formalism of Petri nets are widely used. A business process is a network of dishes, and its properties are set by the analysis of the properties of the network. The aim is to study the methods of displaying an executable business process model in a Petri net. Analysis of the properties of the resulting model allows us to prove a number of important properties: it is a network of free choice and clean without looping.

  16. Fluorescence microscopy imaging of cells with a plasmonic dish integrally molded

    Science.gov (United States)

    Tawa, Keiko; Sasakawa, Chisato; Fujita, Tsuyoshi; Kiyosue, Kazuyuki; Hosokawa, Chie; Nishii, Junji; Oike, Makoto; Kakinuma, Norihiro

    2016-03-01

    A plastic dish with a wavelength-scale periodic structure at a bottom panel was integrally molded and coated with thin metal films. The integrally molded dish called plasmonic dish was applied to bioimaging under a fluorescence microscope. On the plasmonic substrate, the enhanced electric field based on a grating-coupled surface plasmon resonance (GC-SPR) can provide an enhanced fluorescence. In this study, two kinds of cells, human embryonic kidney (HEK) cells and neuronal cells, were observed in our plasmonic dish. Fluorescence images of HEK cells were above 10 times brighter than those obtained on a conventional glass-bottomed dish. Neuronal cells were successfully cultured for 10 d on the plasmonic dish integrally molded, and in fluorescence images with transmitted light, a higher contrast was obtained than in epifluorescence images. The plasmonic dish integrally molded, as well as that fabricated by the UV nanoimprint method, was also found to be useful for sensitive bioimaging.

  17. Special Section on Coloured Petri Nets

    DEFF Research Database (Denmark)

    1998-01-01

    Special section on coloured Petri nets, their basic concepts, analysis methods, tool support and industrial applications.......Special section on coloured Petri nets, their basic concepts, analysis methods, tool support and industrial applications....

  18. High-level Petri Nets

    DEFF Research Database (Denmark)

    of some of the most important papers on the application and theory of high-level Petri nets. In this way it makes the relevant literature more available. It is our hope that the book will be a useful source of information and that, e.g., it can be used in the organization of Petri net courses. To make...... there is only one kind of token and this means that the state of a place is described by an integer (and in many cases even by a boolean). In high-level nets each token can carry a complex information/data - which, e.g., may describe the entire state of a process or a data base. Today most practical...... by other papers. Thus, e.g., none of the original papers introducing the first versions of high-level Petri nets have been included. The introductions to the individual sections mention a number of researchers who have contributed to the development of high-level Petri nets. Detailed references...

  19. Petri Nets in Cryptographic Protocols

    DEFF Research Database (Denmark)

    Crazzolara, Federico; Winskel, Glynn

    2001-01-01

    A process language for security protocols is presented together with a semantics in terms of sets of events. The denotation of process is a set of events, and as each event specifies a set of pre and postconditions, this denotation can be viewed as a Petri net. By means of an example we illustrat...

  20. Towards a Standard for Modular Petri Nets

    DEFF Research Database (Denmark)

    Kindler, Ekkart; Petrucci, Laure

    2009-01-01

    as a mechanism for modules in Petri nets that is independent from a particular version of Petri nets and that can mimic many composition mechanisms by a simple import and export concept. Due to its generality, the semantics of modular PNML was only informally defined. Moreover, modular PNML did not define which...... concepts could or should be subject to import and export in high-level Petri nets. In this paper, we formalise a minimal version of modular high-level Petri nets, which is based on the concepts of modular PNML. This shows that modular PNML can be formalised once a specific version of Petri net is fixed...

  1. Delta Semantics Defined By Petri Nets

    DEFF Research Database (Denmark)

    Jensen, Kurt; Kyng, Morten; Madsen, Ole Lehrmann

    This report is identical to an earlier version of May 1978 except that Chapter 5 has been revised. A new paper: "A Petri Net Definition of a System Description Language", DAIMI, April 1979, 20 pages, extends the Petri net model to include a data state representing the program variables. Delta...... and the possibility of using predicates to specify state changes. In this paper a formal semantics for Delta is defined and analysed using Petri nets. Petri nets was chosen because the ideas behind Petri nets and Delta concide on several points. A number of proposals for changes in Delta, which resulted from...

  2. Verifying Time Petri Nets by Linear Programming

    Institute of Scientific and Technical Information of China (English)

    李宣东

    2001-01-01

    The paper proposes an approach to solving some verification problems of time Petri nets using linear programming. The approach is based on the observation that for loop-closed time Petri nets, it is only necessary to investigate a finite prefix of an untimed run of the underlying Petri net. Using the technique the paper gives solutions to reachability and bounded delay timing analysis problems. For both problems algorithms are given, that are decision procedures for loop-closed time Petri nets, and semi-decision procedures for general time Petri nets.

  3. Behavior Relativity of Petri Nets

    Institute of Scientific and Technical Information of China (English)

    蒋昌俊; 王怀清; 廖少毅

    2002-01-01

    This paper presents a novel methodology for modelling and analyzing of behav-ior relations of concurrent systems. The set of all firing sequences of a Petri net is an importanttool for describing the dynamic behavior of concurrent systems. In this paper, the behaviorrelativity of two concurrent subsystems in their synchronous composition is presented. Such be-havior relativities, including Controlled Relativity, United Relativity, Interactive Relativity andExclusive Relativity, are defined respectively. The properties of the relativities are discussed indetail. The analysis method for these properties is based on minimum T-invariants, when twosubsystems are live bounded Petri nets. A well-known example has also been analyaed usingthe new methodology to demonstrate the advantages of the proposed methodology.

  4. Process of Petri Nets Extension

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    To describe the dynamic semantics for the network computing, the concept on process is presented based on the semantic model with variable, resource and relation. Accordingly, the formal definition of process and the mapping rules from the specification of Petri nets extension to process are discussed in detail respectively. Based on the collective concepts of process, the specification of dynamic semantics also is constructed as a net system. Finally, to illustrate process intuitively, an example is specified completely.

  5. Shenandoah parabolic dish solar collector

    Energy Technology Data Exchange (ETDEWEB)

    Kinoshita, G.S.

    1985-01-01

    The objectives of the Shenandoah, Georgia, Solar Total Energy System are to design, construct, test, and operate a solar energy system to obtain experience with large-scale hardware systems for future applications. This report describes the initial design and testing activities conducted to select and develop a collector that would serve the need of such a solar total energy system. The parabolic dish was selected as the collector most likely to maximize energy collection as required by this specific site. The fabrication, testing, and installation of the parabolic dish collector incorporating improvements identified during the development testing phase are described.

  6. Shenandoah parabolic dish solar collector

    Energy Technology Data Exchange (ETDEWEB)

    Kinoshita, G.S.

    1985-01-01

    The objectives of the Shenandoah, Georgia, Solar Total Energy System are to design, construct, test, and operate a solar energy system to obtain experience with large-scale hardware systems for future applications. This report describes the initial design and testing activities conducted to select and develop a collector that would serve the need of such a solar total energy system. The parabolic dish was selected as the collector most likely to maximize energy collection as required by this specific site. The fabrication, testing, and installation of the parabolic dish collector incorporating improvements identified during the development testing phase are described.

  7. Process expression of bounded Petri nets

    Institute of Scientific and Technical Information of China (English)

    吴哲辉

    1996-01-01

    The concept of process expression of bounded Petri nets is presented.Moreover,an algorithm to find the process expression for a bounded Petri net is given.A process expression of a bounded Petri net is a regular expression whose every alphabet symbol represents a basic subprocess of the net.The regular set expressed by the regular expression is the set of all surjective processes of a bounded Petri net.A surjective process of a bounded Petri net is a process of this net in which every s-cut corresponds to a reachable marking of the net.Therefore,all surjective processes of a bounded Petri net can be obtained as long as its process expression and the basic subprocess represented by the alphabet symbols of the process expression are given.

  8. Modeling of economic systems with Petri nets

    Directory of Open Access Journals (Sweden)

    Pavel Valeryevich Skorodumov

    2014-09-01

    Full Text Available Modeling is one of the most important tools to study complex systems. Components of both continuous and discrete nature are present in the behavior of contemporary economic systems. The article uses formalism of nested hybrid Petri nets as a tool to study complex economic systems. The author describes basic approaches of simulation modelling, concepts of classical Petri nets, modified means of nested hybrid Petri nets, benefits of their use for systems modeling. The article presents the concept of a universal system of simulation modeling. On the basis of considered approaches the article proposes to develop a universal system of simulation modeling on the basis of the modified machine Petri nets

  9. Petri nets semantics ofπ-calculus

    Institute of Scientific and Technical Information of China (English)

    Zhenhua YU; Yuanli CAI; Haiping XU

    2008-01-01

    As π-calculus based on the interleaving semantics cannot depict the true concurrency and has few supporting tools,it is translated into Petri nets.π-calculus is divided into basic elements,sequence,concurrency,choice and recursive modules.These modules are translated into Petri nets to construct a complicated system.Petri nets semantics for π-calculus visualize system structure as well as system behaviors.The structural analysis techniques allow direct qualitative analysis of the system properties on the structure of the nets.Finally,Petri nets semantics for π-calculus are illustrated by applying them to mobile telephone systems.

  10. Discrete, Continuous, and Hybrid Petri Nets

    CERN Document Server

    David, Rene

    2010-01-01

    Petri Nets were introduced and still successfully used to analyze and model discrete event systems especially in engineering and computer sciences such as in automatic control. Recently this discrete Petri Nets formalism was successfully extended to continuous and hybrid systems. This monograph presents a well written and clearly organized introduction in the standard methods of Petri Nets with the aim to reach an accurate understanding of continuous and hybrid Petri Nets, while preserving the consistency of basic concepts throughout the book. The book is a monograph as well as a didactic tool

  11. Towards a Standard for Modular Petri Nets

    DEFF Research Database (Denmark)

    Kindler, Ekkart; Petrucci, Laure

    2009-01-01

    When designing complex systems, mechanisms for structuring, composing, and reusing system components are crucial. Today, there are many approaches for equipping Petri nets with such mechanisms. In the context of defining a standard interchange format for Petri nets, modular PNML was defined....... Moreover, we present and discuss some more advanced features of modular Petri nets that could be included in the standard. This way, we provide a formal foundation and a basis for a discussion of features to be included in the upcoming standard of a module concept for Petri nets in general and for high...

  12. Petri nets and other models of concurrency

    DEFF Research Database (Denmark)

    Nielsen, Mogens; Sassone, Vladimiro

    1998-01-01

    This paper retraces, collects, and summarises contributions of the authors - in collaboration with others - on the theme of Petri nets and their categorical relationships to other models of concurrency.......This paper retraces, collects, and summarises contributions of the authors - in collaboration with others - on the theme of Petri nets and their categorical relationships to other models of concurrency....

  13. Teaching Petri Nets Using P3

    Science.gov (United States)

    Gasevic, Dragan; Devedzic, Vladan

    2004-01-01

    This paper presents Petri net software tool P3 that is developed for training purposes of the Architecture and organization of computers (AOC) course. The P3 has the following features: graphical modeling interface, interactive simulation by single and parallel (with previous conflict resolution) transition firing, two well-known Petri net…

  14. Dish Stirling solar receiver program

    Science.gov (United States)

    Haglund, R. A.

    1980-01-01

    A technology demonstration of a Dish Stirling solar thermal electric system can be accomplished earlier and at a much lower cost than previous planning had indicated by employing technical solutions that allow already existing hardware, with minimum modifications, to be integrated into a total system with a minimum of development. The DSSR operates with a modified United Stirling p-40 engine/alternator and the JPL Test Bed Concentrator as a completely integrated solar thermal electric system having a design output of 25 kWe. The system is augmented by fossil fuel combustion which ensures a continuous electrical output under all environmental conditions. Technical and economic studies by government and industry in the United States and abroad identify the Dish Stirling solar electric system as the most appropriate, efficient and economical method for conversion of solar energy to electricity in applications when the electrical demand is 10 MWe and less.

  15. Petri Nets for Biologically Motivated Computing

    Directory of Open Access Journals (Sweden)

    J. Kleijn

    2011-01-01

    Full Text Available Petri nets are a general and well-established model of concurrent and distributed computation and behaviour, including that taking place in biological systems. In this survey paper, we are concerned with intrinsic relationships between Petri nets and two formal models inspired by aspects of the functioning of the living cell: membrane systems and reaction systems. In particular, we are interested in the benefits that can result from establishing strong semantical links between Petri nets and membrane systems and reaction systems. We first discuss Petri nets with localities reflecting the compartmentalisation modelled in membrane systems. Then special attention is given to set-nets, a new Petri net model for reaction systems and their qualitative approach to the investigation of the processes carried out by biochemical reactions taking place in the living cell.

  16. Flinders Petrie and Eugenics at UCL

    Directory of Open Access Journals (Sweden)

    Kathleen L. Sheppard

    2010-05-01

    Full Text Available William Matthew Flinders Petrie is considered the father of scientific archaeology and is credited with developing a chronology of Ancient Egypt using the nondescript artefacts that other archaeologists had ignored. He occupied the first chair of Egyptology in England, and was also well-known for the museum built around his personal collection of Egyptian artifacts at University College London. Petrie's archaeological work has been studied by scholars, from various disciplines, for its scholarly, cultural, and historical value, while Petrie's life and career outside of archaeology have been the subject of relatively little study. Petrie himself wrote two life stories: the first, 'Ten Years Digging in Egypt, 1881–1891' (1892, detailed the years before his professorship at UCL; in 1932 he published his second, more complete autobiography, 'Seventy Years in Archaeology'. After he died in 1942 there were various obituaries and memorials that outlined his life and major achievements in archaeology. There was very little written about Petrie the man until 1985, when Margaret Drower's 'Flinders Petrie: A Life in Archaeology' was published; it remains the most comprehensive work on Petrie's life. A thin volume of the correspondence of Hilda and Flinders Petrie also allows a glimpse into life on excavation. In short, much of what is known about Petrie focuses on his excavations in Egypt, his time as Professor of Egyptology at University College London, or the museum that bears his name. Subsequently, as a historical matter, Petrie's work in the discipline of eugenics has rarely been discussed as part of his career.

  17. Recent Advances in Helicobacter pylori Infection in Children: From the Petri Dish to the Playgound

    Directory of Open Access Journals (Sweden)

    Peng-Yuan Zheng

    2003-01-01

    Full Text Available Helicobacter pylori infection is acquired in childhood, plays a causative role in chronic gastritis and peptic ulcer disease, and is associated with the development of gastric cancer. The present review focuses on recent advances in the scientific knowledge of H pylori infection in children, including clinical sequelae, diagnosis and treatment. In addition, recent insights regarding both bacterial and host factors that mediate human diseases associated with H pylori infection are discussed.

  18. Application and Theory of Petri Nets

    DEFF Research Database (Denmark)

    This volume contains the proceedings of the 13th International Conference onApplication and Theory of Petri Nets, held in Sheffield, England, in June 1992. The aim of the Petri net conferences is to create a forum for discussing progress in the application and theory of Petri nets. Typically, the....... Balbo and W. Reisig, 18 submitted papers, and seven project papers. The submitted papers and project presentations were selectedby the programme committee and a panel of referees from a large number of submissions....

  19. Determination of structural and mechanical properties, diffractometry, and thermal analysis of chitosan and hydroxypropylmethylcellulose (HPMC films plasticized with sorbitol

    Directory of Open Access Journals (Sweden)

    Jefferson Rotta

    2011-06-01

    Full Text Available In this work, the structural, mechanical, diffractometric, and thermal parameters of chitosan-hydroxypropylmethylcellulose (HPMC films plasticized with sorbitol were studied. Solutions of HPMC (2% w/v in water and chitosan (2% w/v in 2% acetic acid solution were prepared. The concentration of sorbitol used was 10% (w/w to both polymers. This solutions were mixed at different proportions (100/0; 70/30; 50/50; 30/70, and 0/100 of chitosan and HPMC, respectively, and 20 mL was cast in Petri dishes for further analysis of dried films. The miscibility of polymers was assessed by X-ray diffraction, scanning electronic microscopy (SEM, differential scanning calorimetry (DSC, and thermal gravimetric analysis (TGA. The results obtained indicate that the films are not fully miscible at a dry state despite the weak hydrogen bonding between the polymer functional groups.

  20. Hangzhou People and Bamboo Shoots Dish

    Institute of Scientific and Technical Information of China (English)

    LINDA; LEE

    1995-01-01

    SOON we’ll celebrate the new year. According to Hangzhou tradition, every family will cook a hot dish for this feast which will include shredded winter bamboo shoots, hotbed chives, shredded meat and smoked bean curd. In addition, some families will also cook a dish of "braised

  1. Analysis of Reconfigurable Processors Using Petri Net

    Directory of Open Access Journals (Sweden)

    Hadis Heidari

    2013-07-01

    Full Text Available In this paper, we propose Petri net models for processing elements. The processing elements include: a general-purpose processor (GPP, a reconfigurable element (RE, and a hybrid element (combining a GPP with an RE. The models consist of many transitions and places. The model and associated analysis methods provide a promising tool for modeling and performance evaluation of reconfigurable processors. The model is demonstrated by considering a simple example. This paper describes the development of a reconfigurable processor; the developed system is based on the Petri net concept. Petri nets are becoming suitable as a formal model for hardware system design. Designers can use Petri net as a modeling language to perform high level analysis of complex processors designs processing chips. The simulation does with PIPEv4.1 simulator. The simulation results show that Petri net state spaces are bounded and safe and have not deadlock and the average of number tokens in first token is 0.9901 seconds. In these models, there are only 5% errors; also the analysis time in these models is 0.016 seconds.

  2. Optimization of dish solar collectors

    Science.gov (United States)

    Jaffe, L. D.

    1983-01-01

    Methods for optimizing parabolic dish solar collectors and the consequent effects of various optical, thermal, mechanical, and cost variables are examined. The most important performance optimization is adjusting the receiver aperture to maximize collector efficiency. Other parameters that can be adjusted to optimize efficiency include focal length, and, if a heat engine is used, the receiver temperature. The efficiency maxima associated with focal length and receiver temperature are relatively broad; it may, accordingly, be desirable to design somewhat away from the maxima. Performance optimization is sensitive to the slope and specularity errors of the concentrator. Other optical and thermal variables affecting optimization are the reflectance and blocking factor of the concentrator, the absorptance and losses of the receiver, and, if a heat engine is used, the shape of the engine efficiency versus temperature curve. Performance may sometimes be improved by use of an additional optical element (a secondary concentrator) or a receiver window if the errors of the primary concentrator are large or the receiver temperature is high. Previously announced in STAR as N83-19224

  3. Discrete, continuous, and hybrid petri nets

    CERN Document Server

    David, René

    2004-01-01

    Petri nets do not designate a single modeling formalism. In fact, newcomers to the field confess sometimes to be a little puzzled by the diversity of formalisms that are recognized under this "umbrella". Disregarding some extensions to the theoretical modeling capabilities, and looking at the level of abstraction of the formalisms, Condition/Event, Elementary, Place/Transition, Predicate/Transition, Colored, Object Oriented... net systems are frequently encountered in the literature. On the other side, provided with appropriate interpretative extensions, Controled Net Systems, Marking Diagrams (the Petri net generalization of State Diagrams), or the many-many variants in which time can be explicitly incorporated -Time(d), Deterministic, (Generalized) Stochastic, Fuzzy...- are defined. This represents another way to define practical formalisms that can be obtained by the "cro- product" of the two mentioned dimensions. Thus Petri nets constitute a modeling paradigm, understandable in a broad sense as "the total...

  4. A STUDY OF FUZZY LOGICAL PETRI NETS AND ITS APPLICATION

    Institute of Scientific and Technical Information of China (English)

    Jiang Changjun

    2001-01-01

    In this paper, a fuzzy Petri net approach to modelling fuzzy rule-based reasoning is proposed. Logical Petri net (LPN) and fuzzy logical Petri net (FLPN) are defined. The backward reasoning algorithm based on sub-fuzzy logical Petri net is given. It is simpler than the conventional algorithm of forward reasoning from initial propositions. An application to the partial fault model of a car engine in paper Portinale's(1993) is used as an illustrative example of FLPN.

  5. Study on Multi-agent Systems with Colored Petri Nets

    Institute of Scientific and Technical Information of China (English)

    兰顺国; 李军

    2008-01-01

    The approach to model multi-agent systems with hierarchical colored Peal nets is introduced.In a multi-agent system,every agent is modeled with colored Petri net system,and the colored Petri net system of the multi-agent system is a hierarchical colored Petri net system,such that the agents planning deadlock detection and avoidance,can be analyzed with the Petri net system.

  6. State Space Methods for Timed Petri Nets

    DEFF Research Database (Denmark)

    Christensen, Søren; Jensen, Kurt; Mailund, Thomas

    2001-01-01

    We present two recently developed state space methods for timed Petri nets. The two methods reconciles state space methods and time concepts based on the introduction of a global clock and associating time stamps to tokens. The first method is based on an equivalence relation on states which makes...... it possible to condense the usually infinite state space of a timed Petri net into a finite condensed state space without loosing analysis power. The second method supports on-the-fly verification of certain safety properties of timed systems. We discuss the application of the two methods in a number...

  7. The Petrie Museum of Egyptian Archaeology, UCL

    Directory of Open Access Journals (Sweden)

    Jan Picton

    2013-10-01

    Full Text Available University College London houses one of the world’s most important collections of ancient Egyptian material, the majority excavated by Flinders Petrie, his students and his successors in the late 19th and early 20th centuries. It is a museum of archaeology that helps to explain the development of a discipline that was in its infancy when Petrie worked in Egypt over a century ago. It is a teaching collection, its densely packed cases entrancing, and sometimes intimidating, visitors who rave about its old-fashioned feel, but it is anything but frozen in time.

  8. Transactions on Petri Nets and Other Models of Concurrency VII

    DEFF Research Database (Denmark)

    The first section is concerned with the creation of Petri net models and their validation The second section addresses semantic issues and analysis methods The third section is devoted to the automatic synthesis of Petri nets These Transactions publish archival papers in the broad area of Petri n...

  9. Agent-oriented Single Token and Colored Transition Petri Net

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    Petri net is a kind of effective graphic modeling tool. The agent technology is combined with petri net in order to enhance flexibility and extendibility, and the agent-oriented single token and colored transition petri net is proposed. Some characteristics such as liveness, fairness and safety are analyzed. Finally, an example in mould agile manufacturing is given to illustrate the use of it.

  10. Parabolic dish collectors - A solar option

    Science.gov (United States)

    Truscello, V. C.

    1981-01-01

    A description is given of several parabolic-dish high temperature solar thermal systems currently undergoing performance trials. A single parabolic dish has the potential for generating 20 to 30 kW of electricity with fluid temperatures from 300 to 1650 C. Each dish is a complete power-producing unit, and may function either independently or as part of a group of linked modules. The two dish designs under consideration are of 11 and 12 meter diameters, yielding receiver operating temperatures of 925 and 815 C, respectively. The receiver designs described include (1) an organic working fluid (toluene) Rankine cycle engine; (2) a Brayton open cycle unit incorporating a hybrid combustion chamber and nozzle and a shaft-coupled permanent magnet alternator; and (3) a modified Stirling cycle device originally designed for automotive use. Also considered are thermal buffer energy storage and thermochemical transport and storage.

  11. The Translation of Chinese Dish Names

    Institute of Scientific and Technical Information of China (English)

    龚佳文

    2015-01-01

    The traditional food of a nation reflects its historical and cultural characteristics This thesis begins with an introduction to the translation situation of Chinese dish names and its existing problem nowadays, and proceeds to the translation principles and tactics for English translation of the names of Chinese dishes, based on Eugene A. Nida’ s Functional Equivalence, with an aim to improve translation efficiency and promote cross-cultural communication, and promoting Chinese food culture throughout the globe.

  12. A Brief Introduction to Coloured Petri Nets

    DEFF Research Database (Denmark)

    Jensen, Kurt

    1997-01-01

    Coloured Petri Nets (CP-nets or CPN) is a graphical oriented language for design, specification, simulation and verification of systems. It is in particular well- suited for systems in which communication, synchronisation and resource sharing are important. Typical examples of application areas a...

  13. Reachability via Compositionality in Petri nets

    OpenAIRE

    Sobocinski, Paweł; Stephens, Owen

    2013-01-01

    We introduce a novel technique for checking reachability in Petri nets that relies on a recently introduced compositional algebra of nets. We prove that the technique is correct, and discuss our implementation. We report promising experimental results on some well-known examples.

  14. Regular Event Structures and Finite Petri Nets

    DEFF Research Database (Denmark)

    Nielsen, M.; Thiagarajan, P.S.

    2002-01-01

    We present the notion of regular event structures and conjecture that they correspond exactly to finite 1-safe Petri nets. We show that the conjecture holds for the conflict-free case. Even in this restricted setting, the proof is non-trivial and involves a natural subclass of regular event...

  15. Petri-Net Simulations of Communications Networks.

    Science.gov (United States)

    1980-03-01

    incorporate graphics output are more eas ly understood erd have considerable educational value. ,. The results of this research indicate that the...operate and manage the systems will be better educated and more professionally competent? 48 -9 FJ IV. AN INTRODUCTION TO PETRI-NETS A. INTRODUCTION...34 VRSIN 1.. aklETPCAE .... YP n) 56 oinf( VRIO 2.. PCKTPEREENATON.. 1282\

  16. Petri Nets and Semantics of System Descriptions

    DEFF Research Database (Denmark)

    Jensen, Kurt; Kyng, Morten

    1982-01-01

    This paper discusses the use of Petri nets as a semantic tool in the design of languages and in the construction and analysis of system descriptions. The topics treated are: Languages based on nets. The problem of time in nets. Nets and related models. Nets and formal semantics. Parallel program...

  17. Sociophysics of sexism: normal and anomalous petrie multipliers

    Science.gov (United States)

    Eliazar, Iddo

    2015-07-01

    A recent mathematical model by Karen Petrie explains how sexism towards women can arise in organizations where male and female are equally sexist. Indeed, the Petrie model predicts that such sexism will emerge whenever there is a male majority, and quantifies this majority bias by the ‘Petrie multiplier’: the square of the male/female ratio. In this paper—emulating the shift from ‘normal’ to ‘anomalous’ diffusion—we generalize the Petrie model to a stochastic Poisson model that accommodates heterogeneously sexist men and woman, and that extends the ‘normal’ quadratic Petrie multiplier to ‘anomalous’ non-quadratic multipliers. The Petrie multipliers span a full spectrum of behaviors which we classify into four universal types. A variation of the stochastic Poisson model and its Petrie multipliers is further applied to the context of cyber warfare.

  18. A new variant of Petri net controlled grammars

    Science.gov (United States)

    Jan, Nurhidaya Mohamad; Turaev, Sherzod; Fong, Wan Heng; Sarmin, Nor Haniza

    2015-10-01

    A Petri net controlled grammar is a Petri net with respect to a context-free grammar where the successful derivations of the grammar can be simulated using the occurrence sequences of the net. In this paper, we introduce a new variant of Petri net controlled grammars, called a place-labeled Petri net controlled grammar, which is a context-free grammar equipped with a Petri net and a function which maps places of the net to productions of the grammar. The language consists of all terminal strings that can be obtained by parallelly applying multisets of the rules which are the images of the sets of the input places of transitions in a successful occurrence sequence of the Petri net. We study the effect of the different labeling strategies to the computational power and establish lower and upper bounds for the generative capacity of place-labeled Petri net controlled grammars.

  19. Automatic pipeline operation using Petri Nets

    Energy Technology Data Exchange (ETDEWEB)

    Moreira, Guilherme O. [PETROBRAS TRANSPORTE S.A., Rio de Janeiro, RJ (Brazil)

    2009-07-01

    A pipeline operation requires several actions, attention and time from the control room operator in each of its operating phases. This article proposition is to use automation as something more than a remote control, drastically reducing the number of repetitive and routine actions needed from the operator to start and stop the system, granting more time for system supervision, decision making during critical conditions and avoiding errors caused due to the need of several actions being executed in a short period of time. To achieve these objectives the pipeline operation will be modeled as a Petri Net consisting of states, event and actions. A methodology for converting this Petri Net into a Ladder controller code will also be proposed. (author)

  20. Modeling and analysis using hybrid Petri nets

    CERN Document Server

    Ghomri, Latéfa

    2007-01-01

    This paper is devoted to the use of hybrid Petri nets (PNs) for modeling and control of hybrid dynamic systems (HDS). Modeling, analysis and control of HDS attract ever more of researchers' attention and several works have been devoted to these topics. We consider in this paper the extensions of the PN formalism (initially conceived for modeling and analysis of discrete event systems) in the direction of hybrid modeling. We present, first, the continuous PN models. These models are obtained from discrete PNs by the fluidification of the markings. They constitute the first steps in the extension of PNs toward hybrid modeling. Then, we present two hybrid PN models, which differ in the class of HDS they can deal with. The first one is used for deterministic HDS modeling, whereas the second one can deal with HDS with nondeterministic behavior. Keywords: Hybrid dynamic systems; D-elementary hybrid Petri nets; Hybrid automata; Controller synthesis

  1. Modeling workflow using XML and Petri net

    Institute of Scientific and Technical Information of China (English)

    杨东; 温泉; 张申生

    2004-01-01

    Nowadays an increasing number of workflow products and research prototypes begin to adopt XML for representing workflow models owing to its easy use and well understanding for people and machines. However, most of workflow products and research prototypes provide the few supports for the verification of XML-based workflow model, such as free-deadlock properties, which is essential to successful application of workflow technology. In this paper, we tackle this problem by mapping the XML-based workflow model into Petri-net, a kind of well-known formalism for modeling,analyzing and verifying system. As a result, the XML-based workflow model can be automatically verified with the help of general Petri-net tools, such as DANAMICS. The presented approach not only enables end users to represent workflow model with XML-based modeling language, but also the correctness of model can be ensured, thus satisfying the needs of business processes.

  2. Automatic pipeline operation using Petri Nets

    Energy Technology Data Exchange (ETDEWEB)

    Moreira, Guilherme O. [PETROBRAS TRANSPORTE S.A., Rio de Janeiro, RJ (Brazil)

    2009-07-01

    A pipeline operation requires several actions, attention and time from the control room operator in each of its operating phases. This article proposition is to use automation as something more than a remote control, drastically reducing the number of repetitive and routine actions needed from the operator to start and stop the system, granting more time for system supervision, decision making during critical conditions and avoiding errors caused due to the need of several actions being executed in a short period of time. To achieve these objectives the pipeline operation will be modeled as a Petri Net consisting of states, event and actions. A methodology for converting this Petri Net into a Ladder controller code will also be proposed. (author)

  3. A note on the Petri loci

    CERN Document Server

    Bruno, Andrea

    2010-01-01

    Let $\\M_g$ be the course moduli space of complex projective nonsingular curves of genus $g$. We prove that when the Brill-Noether number $\\rho(g,r,n)$ is non-negative every component of the Petri locus $P^r_{g,n}\\subset \\M_g$ whose general member is a curve $C$ such that $W^{r+1}_n(C) = \\emptyset$, has codimension one in $\\M_g$.

  4. A HYBRID PETRI-NET MODEL OF GRID WORKFLOW

    Institute of Scientific and Technical Information of China (English)

    Ji Yimu; Wang Ruchuan; Ren Xunyi

    2008-01-01

    In order to effectively control the random tasks submitted and executed in grid workflow, a grid workflow model based on hybrid petri-net is presented. This model is composed of random petri-net, colored petri-net and general petri-net. Therein random petri-net declares the relationship between the number of grid users' random tasks and the size of service window and computes the server intensity of grid system. Colored petri-net sets different color for places with grid services and provides the valid interfaces for grid resource allocation and task scheduling. The experiment indicated that the model presented in this letter could compute the valve between the number of users' random tasks and the size of grid service window in grid workflow management system.

  5. Dish-mounted latent heat buffer storage

    Science.gov (United States)

    Manvi, R.

    1981-01-01

    Dish-mounted latent heat storage subsystems for Rankine, Brayton, and Stirling engines operating at 427 C, 816 C, and 816 C respectively are discussed. Storage requirements definition, conceptual design, media stability and compatibility tests, and thermal performance analyses are considered.

  6. Transactions on Petri Nets and Other Models of Concurrency VI

    DEFF Research Database (Denmark)

    The sixth volume of ToPNoC includes revised versions of selected papers from workshops and tutorials held at the 32nd International Conference on Application and Theory of Petri Nets and Concurrency. It also contains a special section on Networks, Protocols, and Services, as well as a contributed...... paper submitted through the regular submission track of ToPNoC. The 14 papers cover a diverse range of topics including model checking and system verification, synthesis, foundational work on specific classes of Petri nets, and innovative applications of Petri nets and other models of concurrency. Thus...... this volume gives a good view of ongoing concurrent systems and Petri nets research....

  7. Application of Petri Net to Fault Diagnosis in Satellite

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    A prototype of fault diagnosis based on Petri net, which is developed for a satellite tele-control subsystem, is introduced in this paper. Its structure is first given with the emphasis on a Petri net modeling tool which is designed using the object oriented method. The prototype is connected to the database with DAO (Date Access Object) technique, and makes the Petri net's firing mechanism and its analyzing methods to be packed up as DLL (Dynamic Link Library) documents. Compared with the rule-based expert system method, the Petri net-based one can store the knowledge in mathematical matrix and make inference more quickly and effectively.

  8. Proceedings: Fourth Parabolic Dish Solar Thermal Power Program Review

    Science.gov (United States)

    1983-01-01

    The results of activities within the parabolic dish technology and applications development program are presented. Stirling, organic Rankine and Brayton module technologies, associated hardware and test results to date; concentrator development and progress; economic analyses; and international dish development activities are covered. Two panel discussions, concerning industry issues affecting solar thermal dish development and dish technology from a utility/user perspective, are also included.

  9. An ECNO semantics for Petri nets

    DEFF Research Database (Denmark)

    Kindler, Ekkart

    2012-01-01

    The Event Coordination Notation (ECNO) allows modelling the behaviour of software on top of structural software models - and to generate program code from these models fully automatically. ECNO distinguishes between the local behaviour of elements (objects) and the global behaviour, which denes t...... work. In this paper, we will show that the ECNO, in turn, can be used for modelling the behaviour of Petri nets in a simple and concise way. What is more, we will show that the ECNO semantics of Place/Transition Systems can easily be extended to so-called signal-event nets....

  10. Stochastic petri nets for wireless networks

    CERN Document Server

    Lei, Lei; Zhong, Zhangdui

    2015-01-01

    This SpringerBrief presents research in the application of Stochastic Petri Nets (SPN) to the performance evaluation of wireless networks under bursty traffic. It covers typical Quality-of-Service performance metrics such as mean throughput, average delay and packet dropping probability. Along with an introduction of SPN basics, the authors introduce the key motivation and challenges of using SPN to analyze the resource sharing performance in wireless networks. The authors explain two powerful modeling techniques that treat the well-known state space explosion problem: model decomposition and

  11. The Existing Problems in the Translation of Chinese Dish Names

    Institute of Scientific and Technical Information of China (English)

    易高燕

    2009-01-01

    China has a long rich history of dietary culture, and with the increasing communication with other countries and cultures, it is of great significance to translate the Chinese dish names and food with accuracy and efficiency. In this easy, the writer discusses some existing problems in the translation of Chinese dish names, and put forward several useful methods in translating Chinese dish names.

  12. Requirements and Evaluation of tool papers for PETRI NETS

    DEFF Research Database (Denmark)

    Franceschinis, Giuliana; van Hee, Kees; Kindler, Ekkart

    2008-01-01

    This paper gives guidelines for the publication of papers on software tools, in particular for Petri net tools. The guidelines are illustrated by an example.......This paper gives guidelines for the publication of papers on software tools, in particular for Petri net tools. The guidelines are illustrated by an example....

  13. Requirements and Evaluation of tool papers for PETRI NETS

    DEFF Research Database (Denmark)

    Franceschinis, Giuliana; van Hee, Kees; Kindler, Ekkart;

    2008-01-01

    This paper gives guidelines for the publication of papers on software tools, in particular for Petri net tools. The guidelines are illustrated by an example.......This paper gives guidelines for the publication of papers on software tools, in particular for Petri net tools. The guidelines are illustrated by an example....

  14. Transactions on Petri Nets and Other Models of Concurrency VII

    DEFF Research Database (Denmark)

    -stage refereeing process. ToPNoC contains: - Revised versions of a selection of the best papers from workshops and tutorials at the annual Petri net conferences - Special sections/issues within particular subareas (similar to those published in the Advances in Petri Nets series) - Other papers invited...

  15. Petrie and the Intriguing Idiosyncrasies of Racism

    Directory of Open Access Journals (Sweden)

    Jason D. Ramsey

    2004-11-01

    Full Text Available William Matthews Flinders Petrie, ‘generally regarded as the father of modern Near Eastern archaeology’ (Silberman 1991:80, is remembered as a veritable genius, renowned for his powerful memory and intellectual abilities which played an important part in many of the ground-breaking developments in methodology he brought about. Yet modern archaeologists are selective in deciding which parts of Petrie’s legacy are to be highlighted. As a corrective to this, Silberman (1991, 1999 has not only drawn attention to the racist ideology that permeated Petrie’s thinking, but also suggests that this framework of thought crucially influenced many of his revolutionary interpretive techniques. The final deed Petrie envisaged for himself was the donation of his head to the Royal College of Surgeons in London ‘for further scientific study . . . [and] as a specimen of a typical British skull’ (Drower 1985:424. As far as Silberman (1999 is concerned, such an act was wholly symbolic of Petrie’s raciallyinformed viewpoint and of his self-identity.

  16. A compendium of solar dish/Stirling technology

    Energy Technology Data Exchange (ETDEWEB)

    Stine, W.B. [California State Polytechnic Univ., Pomona, CA (United States). Dept. of Mechanical Engineering; Diver, R.B. [Sandia National Labs., Albuquerque, NM (United States)

    1994-01-01

    This report surveys the emerging dish/Stirling technology. It documents -- using consistent terminology the design characteristics of dish concentrators, receivers, and Stirling engines applicable to solar electric power generation. Development status and operating experience for each system and an overview of dish/Stirling technology are also presented. This report enables comparisons of concentrator, receiver, and engine technologies. Specifications and performance data are presented on systems and on components that are in use or that could be used in dish/Stirling systems. This report is organized into two parts: The first part (Chapters 1 through 4) provides an overview of dish/Stirling technology -- the dish/ Stirling components (concentrator, receiver, and engine/alternator), current technology, basic theory, and technology development. The second part (Chapters 5 through 7) provides a detailed survey of the existing dish/Stirling concentrators, receivers, and engine/alternators.

  17. Creating "living" polymer surfaces to pattern biomolecules and cells on common plastics.

    Science.gov (United States)

    Li, Chunyan; Glidle, Andrew; Yuan, Xiaofei; Hu, Zhixiong; Pulleine, Ellie; Cooper, Jon; Yang, Wantai; Yin, Huabing

    2013-05-13

    Creating patterns of biomolecules and cells has been applied widely in many fields associated with the life sciences, including diagnostics. In these applications it has become increasingly apparent that the spatiotemporal arrangement of biological molecules in vitro is important for the investigation of the cellular functions found in vivo. However, the cell patterning techniques often used are limited to creating 2D functional surfaces on glass and silicon. In addition, in general, these procedures are not easy to implement in conventional biological laboratories. Here, we show the formation of a living poly(ethylene glycol) (PEG) layer that can be patterned with visible light on plastic surfaces. This new and simple method can be expanded to pattern multiple types of biomolecule on either a previously formed PEG layer or a plastic substrate. Using common plastic wares (i.e., polyethylene films and polystyrene cell culture Petri-dishes), we demonstrate that these PEG-modified surfaces have a high resistance to protein adsorption and cell adhesion, while at the same time, being capable of undergoing further molecular grafting with bioactive motifs. With a photomask and a fluid delivery system, we illustrate a flexible way to immobilize biological functions with a high degree of 2D and 3D spatial control. We anticipate that our method can be easily implemented in a typical life science laboratory (without the need for specialized lithography equipment) offering the prospect of imparting desirable properties to plastic products, for example, the creation of functional microenvironments in biological studies or reducing biological adhesion to surfaces.

  18. Greenhouse Modeling Using Continuous Timed Petri Nets

    Directory of Open Access Journals (Sweden)

    José Luis Tovany

    2013-01-01

    Full Text Available This paper presents a continuous timed Petri nets (ContPNs based greenhouse modeling methodology. The presented methodology is based on the definition of elementary ContPN modules which are designed to capture the components of a general energy and mass balance differential equation, like parts that are reducing or increasing variables, such as heat, CO2 concentration, and humidity. The semantics of ContPN is also extended in order to deal with variables depending on external greenhouse variables, such as solar radiation. Each external variable is represented by a place whose marking depends on an a priori known function, for instance, the solar radiation function of the greenhouse site, which can be obtained statistically. The modeling methodology is illustrated with a greenhouse modeling example.

  19. Pragmatics Annotated Coloured Petri Nets for Protocol Software Generation and Verification

    DEFF Research Database (Denmark)

    Fagerland Simonsen, Kent Inge; Kristensen, Lars Michael; Kindler, Ekkart

    2015-01-01

    PetriCode is a tool that supports automated generation of protocol software from a restricted class of Coloured Petri Nets (CPNs) called Pragmatics Annotated Coloured Petri Nets (PA-CPNs). Petri-Code and PA-CPNs have been designed with five main requirements in mind, which include the same model...

  20. Robots arm motion representation in Petri NETS using sequent calculus

    Directory of Open Access Journals (Sweden)

    Syed Uzair Ahmad

    2015-12-01

    Full Text Available There are many sort of motion in robots structure. Such as the robot locomotion robot jumps robots picking and so on but all are presented through Petri NETS. The one motion which is also the important one and most worthy motion of the robots is the robots arm motion. Which till yet not represented through Petri NETS. In this paper we are going to represent the motion of the robot arm in different angles and different aspect, such as up, down, circular, back and front moment of the robot arm, through Petri net we can present the complex form of motions into simplex paths.

  1. Computer Tools for Construction, Modification and Analysis of Petri Nets

    DEFF Research Database (Denmark)

    Jensen, Kurt

    1987-01-01

    The practical use of Petri nets is — just as any other description technique — very dependent on the existence of adequate computer tools, which may assist the user to cope with the many details of a large description. For Petri nets there is a need for tools supporting construction of nets....... It describes some of the requirements which these tools must fulfil, in order to support the user in a natural and effective way. Finally some references are given to papers which describe examples of existing Petri net tools....

  2. PNet: A Python Library for Petri Net Modeling and Simulation

    Directory of Open Access Journals (Sweden)

    Zhu En Chay

    2016-07-01

    Full Text Available Petri Net is a formalism to describe changes between 2 or more states across discrete time and has been used to model many systems. We present PNet – a pure Python library for Petri Net modeling and simulation in Python programming language. The design of PNet focuses on reducing the learning curve needed to define a Petri Net by using a text-based language rather than programming constructs to define transition rules. Complex transition rules can be refined as regular Python functions. To demonstrate the simplicity of PNet, we present 2 examples – bread baking, and epidemiological models.

  3. Petri nets SM-cover-based on heuristic coloring algorithm

    Science.gov (United States)

    Tkacz, Jacek; Doligalski, Michał

    2015-09-01

    In the paper, coloring heuristic algorithm of interpreted Petri nets is presented. Coloring is used to determine the State Machines (SM) subnets. The present algorithm reduces the Petri net in order to reduce the computational complexity and finds one of its possible State Machines cover. The proposed algorithm uses elements of interpretation of Petri nets. The obtained result may not be the best, but it is sufficient for use in rapid prototyping of logic controllers. Found SM-cover will be also used in the development of algorithms for decomposition, and modular synthesis and implementation of parallel logic controllers. Correctness developed heuristic algorithm was verified using Gentzen formal reasoning system.

  4. An Automatic High Efficient Method for Dish Concentrator Alignment

    OpenAIRE

    Yong Wang; Song Li; Jinshan Xu; Yijiang Wang; Xu Cheng; Changgui Gu; Shengyong Chen; Bin Wan

    2014-01-01

    Alignment of dish concentrator is a key factor to the performance of solar energy system. We propose a new method for the alignment of faceted solar dish concentrator. The isosceles triangle configuration of facet’s footholds determines a fixed relation between light spot displacements and foothold movements, which allows an automatic determination of the amount of adjustments. Tests on a 25 kW Stirling Energy System dish concentrator verify the feasibility, accuracy, and efficiency of our...

  5. PETRI NET MODELING OF COMPUTER VIRUS LIFE CYCLE

    African Journals Online (AJOL)

    Dr Obe

    dynamic system analysis is applied to model the virus life cycle. Simulation of the .... of successful applications of Petri nets include distributed database systems, communication protocols, .... Concepts and Design". McGraw-Hill Computer.

  6. Methods for behavior descriptions of structure-complex Petri nets

    Institute of Scientific and Technical Information of China (English)

    Qingtian ZENG; Zhehui WU

    2004-01-01

    Petri net language is a powerful tool for describing dynamic behaviors of physical systems. However, it is not easy to obtain the language expression for a given Petri net especially a structure-complex net. In this paper, we first analyze the behaviors of S-nets, which are structure-simple. With the decomposition method based on a given index function on the place set, a given structure-complex Petri net can be decomposed into a set of structure-simple S-nets. With the language relationships between the original system and the decomposed subnets, an algorithm to obtain the language expression of a given structure-complex net system is presented, which benefits the analysis of physical systems based on the Petri net language.

  7. Proceedings of the Fifth Parabolic Dish Solar Thermal Power Program

    Science.gov (United States)

    Lucas, J. W. (Editor)

    1984-01-01

    The proceedings of the Fifth Parabolic Dish Solar Thermal Power Program Annual Review are presented. The results of activities within the Parabolic Dish Technology and Module/Systems Development element of the Department of Energy's Solar Thermal Energy Systems Program were emphasized. Among the topics discussed were: overall Project and Program aspects, Stirling and Brayton module development, concentrator and engine/receiver development along with associated hardware and test results; distributed systems operating experience; international parabolic dish development activities; and non-DOE-sponsored domestic dish activities. Solar electric generation was also addressed.

  8. Practical Use of High-level Petri Net

    DEFF Research Database (Denmark)

    The aim of the workshop is to bring together researchers and practitioners with interests in the use of high-level nets and their tools for practical applications. A typical paper is expected to report on a case study where high-level Petri nets and their tools have been used in practice. We also...... welcome papers describing a tool, a methodology, or other developments that have proved successful to make high-level Petri nets more applicable in practice....

  9. Software Tool Integrating Data Flow Diagrams and Petri Nets

    Science.gov (United States)

    Thronesbery, Carroll; Tavana, Madjid

    2010-01-01

    Data Flow Diagram - Petri Net (DFPN) is a software tool for analyzing other software to be developed. The full name of this program reflects its design, which combines the benefit of data-flow diagrams (which are typically favored by software analysts) with the power and precision of Petri-net models, without requiring specialized Petri-net training. (A Petri net is a particular type of directed graph, a description of which would exceed the scope of this article.) DFPN assists a software analyst in drawing and specifying a data-flow diagram, then translates the diagram into a Petri net, then enables graphical tracing of execution paths through the Petri net for verification, by the end user, of the properties of the software to be developed. In comparison with prior means of verifying the properties of software to be developed, DFPN makes verification by the end user more nearly certain, thereby making it easier to identify and correct misconceptions earlier in the development process, when correction is less expensive. After the verification by the end user, DFPN generates a printable system specification in the form of descriptions of processes and data.

  10. Scheduling multirobot operations in manufacturing by truncated Petri nets

    Science.gov (United States)

    Chen, Qin; Luh, J. Y.

    1995-08-01

    Scheduling of operational sequences in manufacturing processes is one of the important problems in automation. Methods of applying Petri nets to model and analyze the problem with constraints on precedence relations, multiple resources allocation, etc. have been available in literature. Searching for an optimum schedule can be implemented by combining the branch-and-bound technique with the execution of the timed Petri net. The process usually produces a large Petri net which is practically not manageable. This disadvantage, however, can be handled by a truncation technique which divides the original large Petri net into several smaller size subnets. The complexity involved in the analysis of each subnet individually is greatly reduced. However, when the locally optimum schedules of the resulting subnets are combined together, it may not yield an overall optimum schedule for the original Petri net. To circumvent this problem, algorithms are developed based on the concepts of Petri net execution and modified branch-and-bound process. The developed technique is applied to a multi-robot task scheduling problem of the manufacturing work cell.

  11. Petri 网结点精化及其应用%Petri Nets Node Refinement and Its Application

    Institute of Scientific and Technical Information of China (English)

    祁方民

    2014-01-01

    在Petri网精化概念的基础上,给出一种解决Petri网结点爆炸问题的方法,该方法针对精化的定义,从库所和变迁的约束条件入手,分析结点精化的可行性和方法,并给出证明。该方法的建立为今后利用Petri网进行建模提供了必要帮助。%A solution of Petri nets node explosion problem is given based on the concept of node refinement on Petri nets , and from this definition and the bound condition of place and transition , we analyze the feasibility and methods of node refinement on Petri net, which is helpful on modeling and verification with Petri net later .

  12. Flexible Sheet-Type Sensor for Noninvasive Measurement of Cellular Oxygen Metabolism on a Culture Dish.

    Directory of Open Access Journals (Sweden)

    Mari Kojima

    Full Text Available A novel flexible sensor was developed for the noninvasive oxygen metabolism measurement of cultivated cells and tissues. This device is composed of a transparent double-layered polymer sheet of ethylene-vinyl alcohol (EVOH and poly(dimethylsiloxane (PDMS having an array of microhole structures of 90 μm diameter and 50 μm depth on its surface. All the microhole structures were equipped with a 1-μm-thick optical chemical sensing layer of platinum porphyrin-fluoropolymer on their bottom. The three-dimensional microstructures of the sensor were fabricated by a newly developed simple and low-cost production method named self-aligned hot embossing. The device was designed to be attached slightly above the cells cultivated on a dish to form a temporarily closed microspace over the target cells during measurement. Since the change in oxygen concentration is relatively fast in the microcompartmentalized culture medium, a rapid evaluation of the oxygen consumption rate is possible by measuring the phosphorescence lifetime of the platinum porphyrin-fluoropolymer. The combined use of the device and an automated optical measurement system enabled the high-throughput sensing of cellular oxygen consumption (100 points/min. We monitored the oxygen metabolism of the human breast cancer cell line MCF7 on a Petri dish and evaluated the oxygen consumption rate to be 0.72 ± 0.12 fmol/min/cell. Furthermore, to demonstrate the utility of the developed sensing system, we demonstrated the mapping of the oxygen consumption rate of rat brain slices and succeeded in visualizing a clear difference among the layer structures of the hippocampus, i.e., the cornu ammonis (CA1 and CA3 and dentate gyrus (DG.

  13. Cell scientist to watch - Sabine Petry.

    Science.gov (United States)

    2016-11-15

    Originally from Germany, Sabine Petry received her Diploma (MSc) from Goethe University in Frankfurt and undertook her Master's thesis at the Max Planck Institute of Biophysics. She then moved to the UK to pursue a PhD under the supervision of Venki Ramakrishnan at the MRC Laboratory of Molecular Biology in Cambridge. In 2008, Sabine started her postdoctoral work in the laboratory of Ron Vale at the University of California, San Francisco as an EMBO fellow and then an HHMI postdoctoral fellow of the Life Science Research Foundation. She started her own lab at Princeton University in 2013, and her work has already been recognised with an NIH Pathway to Independence K99/R00 Award and the Kimmel Scholar Award for Cancer Research; she was also named a Pew Scholar and Packard Fellow in 2014. Sabine's research combines structural, biophysical, biochemical and cell biology methods to study the mechanism by which microtubules build cellular structures, allowing cells to attain a particular shape and function. © 2016. Published by The Company of Biologists Ltd.

  14. Dish/Stirling for Department of Defense applications final report

    Energy Technology Data Exchange (ETDEWEB)

    Diver, R.B.; Menicucci, D.F. [Sandia National Labs., Albuquerque, NM (United States). Energy and Environment Div.

    1997-03-01

    This report describes a Strategic Environmental Research and Development Program (SERDP) project to field a dish/Stirling system at a southwestern US military facility. This project entitled ``Dish/Stirling for DoD Applications`` was started in August 1993 and was completed in September 1996. The project`s objective was to assist military facilities to field and evaluate emerging environmentally sound and potentially economical dish/Stirling technology. Dish/Stirling technology has the potential to produce electricity at competitive costs while at the same time providing a secure and environmentally benign source of power. In accordance with the SERDP charter, this project leveraged a US Department of Energy (DOE) cost-shared project between Sandia National Laboratories and Cummins Power Generation, Inc. (CPG). CPG is a wholly owned subsidiary of Cummins Engine Company, a leading manufacturer of diesel engines. To accomplish this objective, the project called for the installation of a dish/Stirling system at a military facility to establish first-hand experience in the operation of a dish/Stirling system. To scope the potential DoD market for dish/Stirling technology and to identify the site for the demonstration, a survey of southwestern US military facilities was also conducted. This report describes the project history, the Cummins dish/Stirling system, results from the military market survey, and the field test results.

  15. An Automatic High Efficient Method for Dish Concentrator Alignment

    Directory of Open Access Journals (Sweden)

    Yong Wang

    2014-01-01

    for the alignment of faceted solar dish concentrator. The isosceles triangle configuration of facet’s footholds determines a fixed relation between light spot displacements and foothold movements, which allows an automatic determination of the amount of adjustments. Tests on a 25 kW Stirling Energy System dish concentrator verify the feasibility, accuracy, and efficiency of our method.

  16. El ídish en el teatro argentino

    Directory of Open Access Journals (Sweden)

    David William Foster

    2009-10-01

    Full Text Available Analise de tres instancias de teatro en ídish en Buenos Aires. La primera, un teatro hablado en ídish que surge de los contextos de la inmigración, que tiene que ver con la vida milenaria de los judíos, de los recuerdos del shetl, de los pogroms. La segunda es el teatro de las vivencias en territorio argentino, en el ámbito de la narrativa, ya en ídish, ya en castellano. La tercera ejemplifica el comienzo de la desaparición del ídish, con espectadores de otras ascendencias inmigratorias, que no van a entender el ídish, con la creciente debilidad del ídish en la colectividad, o por efecto de la asimilación o por el trágico hecho de que el ídish había emprendido la enorme decadencia impuestas por el nazismo, que desembocará eventualmente en la muerte del idioma que, en la Argentina y en muchos otros lugares, más se identificaba con los judíos.

  17. Dish stirling solar receiver combustor test program

    Science.gov (United States)

    Bankston, C. P.; Back, L. H.

    1981-01-01

    The operational and energy transfer characteristics of the Dish Stirling Solar Receiver (DSSR) combustor/heat exchanger system was evaluated. The DSSR is designed to operate with fossil fuel augmentation utilizing a swirl combustor and cross flow heat exchanger consisting of a single row of 4 closely spaced tubes that are curved into a conical shape. The performance of the combustor/heat exchanger system without a Stirling engine was studied over a range of operating conditions and output levels using water as the working fluid. Results show that the combustor may be started under cold conditions, controlled safety, and operated at a constant air/fuel ratio (10 percent excess air) over the required range of firing rates. Furthermore, nondimensional heat transfer coefficients based on total heat transfer are plotted versus Reynolds number and compared with literature data taken for single rows of closely spaced tubes perpendicular to cross flow. The data show enhanced heat transfer for the present geometry and test conditions. Analysis of the results shows that the present system meets specified thermal requirements, thus verifying the feasibility of the DSSR combustor design for final prototype fabrication.

  18. Prototype dish testing and analysis at Sandia National Laboratories

    Science.gov (United States)

    Grossman, J. W.; Houser, R. M.; Erdman, W. W.

    1991-12-01

    During the past year, Sandia National Laboratories performed on-sun testing of several dish concentrator concepts. These tests were undertaken at the National Solar Thermal Test Facility (NSTTF). Two of the tests were performed in support of the DOE Concentrator Receiver Development Program. The first was on-sun testing of the single-element stretched-membrane dish; this 7-meter diameter dish uses a single preformed metal membrane with an aluminized polyester optical surface and shows potential for future dish-Stirling systems. The next involved two prototype facets from the Faceted Stretched-Membrane Dish Program. These facets, representing competitive design concepts, are closest to commercialization. Five 1-meter triangular facets were tested on-sun as part of the development program for a solar dynamic system on Space Station Freedom. While unique in character, all the tests utilized the Beam Characterization System (BCS) as the main measurement tool and all were analyzed using the Sandia-developed CIRCE2 computer code. The BCS is used to capture and digitize an image of the reflected concentrator beam that is incident on a target surface. The CIRCE2 program provides a computational tool, which when given the geometry of the concentrator and target as well as other design parameters will predict the flux distribution of the reflected beam. One of these parameters, slope error, is the variable that has a major effect in determining the quality of the reflected beam. The methodology used to combine these two tools to predict uniform slope errors for the dishes is discussed in this document. As the Concentrator Development Programs continue, Sandia will test and evaluate two prototype dish systems. The first, the faceted stretched-membrane dish, is expected to be tested in 1992, followed by the full-scale single-element stretched-membrane dish in 1993. These tests will use the tools and methodology discussed in this document.

  19. A Scheduling Algorithm Based on Petri Nets and Simulated Annealing

    Directory of Open Access Journals (Sweden)

    Rachida H. Ghoul

    2007-01-01

    Full Text Available This study aims at presenting a hybrid Flexible Manufacturing System "HFMS" short-term scheduling problem. Based on the art state of general scheduling algorithms, we present the meta-heuristic, we have decided to apply for a given example of HFMS. That was the study of Simulated Annealing Algorithm SA. The HFMS model based on hierarchical Petri nets, was used to represent static and dynamic behavior of the HFMS and design scheduling solutions. Hierarchical Petri nets model was regarded as being made up a set of single timed colored Petri nets models. Each single model represents one process which was composed of many operations and tasks. The complex scheduling problem was decomposed in simple sub-problems. Scheduling algorithm was applied on each sub model in order to resolve conflicts on shared production resources.

  20. FORRBIDDEN STATE APPROACH FOR PETRI NETS USIGN PLC

    Directory of Open Access Journals (Sweden)

    Elif AYBAR

    2013-06-01

    Full Text Available In this work, the forbidden state controller design approach is considered to realize by using PLC for Petri nets. First, the structure of the ordinary Petri nets is transfer to the ladder diagram form of PLC, a controller design for the forbidden states, the controlled ladder diagram is obtained such that information about the marking vector and the disabled transition, which are obtained by using the de-signed controller. The controlled ladder diagram is obtained such that the information which contains on the state and disabled transition, is added to the ladder diagram. In addition, the algorithm and steps are also given to add the designed controller to the ladder diagram. Consequently, the occurence of the forbidden states is avoided in the considered Petri net by the developed method.

  1. An Algorithm to Construct Concurrent Reachability Graph of Petri Nets

    Institute of Scientific and Technical Information of China (English)

    张金泉; 倪丽娜; 蒋昌俊

    2004-01-01

    Reachability graph is a very important tool to analyze the dynamic properties of Petri nets, but the concurrent relation of transitions in Petri nets cannot be represented by reachability graph. Petri net is a concurrent system, while reachability graph is a serial one. However, concurrency is a kind of property which is not only very significant but also difficult to be analyzed and controlled. This paper presents the concepts of concurrent reachable marking and concurrent reachable graph in order to represent and analyze the concurrent system. The algorithm constructing concurrent reachable marking set and concurrent reachability graph is also shown so that we can study the response problems among services in a network computing environment and analyze the throughput of the system. The Dining Philosophers Problem, which is a classic problem of describing the management of concurrent resources, is given as an example to illustrate the significance of concurrent reachability graph.

  2. On the Decidability of Non Interference over Unbounded Petri Nets

    CERN Document Server

    Best, Eike; Gorrieri, Roberto; 10.4204/EPTCS.51.2

    2011-01-01

    Non-interference, in transitive or intransitive form, is defined here over unbounded (Place/Transition) Petri nets. The definitions are adaptations of similar, well-accepted definitions introduced earlier in the framework of labelled transition systems. The interpretation of intransitive non-interference which we propose for Petri nets is as follows. A Petri net represents the composition of a controlled and a controller systems, possibly sharing places and transitions. Low transitions represent local actions of the controlled system, high transitions represent local decisions of the controller, and downgrading transitions represent synchronized actions of both components. Intransitive non-interference means the impossibility for the controlled system to follow any local strategy that would force or dodge synchronized actions depending upon the decisions taken by the controller after the last synchronized action. The fact that both language equivalence and bisimulation equivalence are undecidable for unbounde...

  3. Implementation of a Neural Network Using Simulator and Petri Nets*

    Directory of Open Access Journals (Sweden)

    Nayden Valkov Nenkov

    2016-01-01

    Full Text Available This paper describes construction of multilayer perceptron by open source neural networks simulator - Neuroph and Petri net. The described multilayer perceptron solves logical function "xor "- exclusive or. The aim is to explore the possibilities of description of the neural networks by Petri Nets. The selected neural network (multilayer perceptron allows to be seen clearly the advantages and disadvantages of the realizing through simulator. The selected logical function does not have a linear separability. After consumption of a neural network on a simulator was investigated implementation by Petri Nets. The results are used to determine and to consider opportunities for different discrete representations of the same model and the same subject area.

  4. The ePNK: An Extensible Petri Net Tool for PNML

    DEFF Research Database (Denmark)

    Kindler, Ekkart

    2011-01-01

    The Petri Net Markup Language (PNML) is an XML-based interchange format for all kinds of Petri nets, which is an ISO/IEC International Standard 15909-2 now. The focus of this standard is on PNML as an interchange format for high-level Petri nets. PNML, however, is more general and allows exchanging...

  5. The ePNK: An Extensible Petri Net Tool for PNML

    DEFF Research Database (Denmark)

    Kindler, Ekkart

    2011-01-01

    The Petri Net Markup Language (PNML) is an XML-based interchange format for all kinds of Petri nets, which is an ISO/IEC International Standard 15909-2 now. The focus of this standard is on PNML as an interchange format for high-level Petri nets. PNML, however, is more general and allows exchanging...

  6. Pragmatics annotated coloured petri nets for protocol software generation and verification

    DEFF Research Database (Denmark)

    Simonsen, Kent Inge Fagerland; Kristensen, Lars M.; Kindler, Ekkart

    2016-01-01

    Pragmatics Annotated Coloured Petri Nets (PA-CPNs) are a restricted class of Coloured Petri Nets (CPNs) developed to support automated generation of protocol software. The practical application of PA-CPNs and the supporting PetriCode software tool have been discussed and evaluated in earlier papers...

  7. Performance of the Southern California Edison Company Stirling dish

    Energy Technology Data Exchange (ETDEWEB)

    Lopez, C.W. [Southern California Edison Co., Rosemead, CA (United States); Stone, K.W. [Mako Enterprises, Huntington Beach, CA (United States)

    1993-10-01

    McDonnell Douglas Astronautics Company (MDAC) and United Stirling AB of Sweden (USAB) formed a joint venture in 1982 to develop and produce a Stirling dish solar generating system. In this report, the six year development and testing program continued by the Southern California Edison Company (SCE) is described. Each Stirling dish module consists of a sun tracking dish concentrator developed by the MDAC and a Stirling engine driven power conversion unit (PCU) developed by USAB. The Stirling dish system demonstrated twice the peak and daily solar-to-electric conversion efficiency of any other system then under development. This system continues to set the performance standard for solar to electric systems being developed in the early 1990`s. Test data are presented and used to estimate the performance of a commercial system.

  8. Shanghai Dishes at the Beijing Asia Jinjiang Hotel

    Institute of Scientific and Technical Information of China (English)

    1996-01-01

    THE Beijing Asia Jinjiang Hotel in east Beijing is neither magnificent nor luxuriant, but the Shanghai cuisine served there makes it popular. The unforgettable dishes are the weapon that this hotel uses to compete with bigger hotels in the neighborhood.

  9. The JPL parabolic dish project. [solar collectors technology development

    Science.gov (United States)

    Truscello, V. C.; Williams, A. N.

    1980-01-01

    The parabolic dish solar collector is a highly versatile concentrating collector system that can produce heat for many thermal processes and electricity by coupling the collector to a suitable heat engine. This paper discusses a project for the development of these collector systems and summarizes contracts with industry for developing the dish subsystems which include concentrator, receiver, and heat engine. An early market for dishes is the dispersed small community market which depends heavily on oil to operate diesel or steam turbine plants in order to generate electricity. The present contracts with industry for conducting engineering experiments using the developed dish hardware to demonstrate the technology in these early opportunity markets is also discussed.

  10. Modelling of Steam Generating Paraboloidal dish Solar Thermal Power System

    Energy Technology Data Exchange (ETDEWEB)

    Siangsukone, P.; Lovegrove, K.

    2006-07-01

    The Australian National University (ANU) has a 400m2 Paraboloidal dish solar concentrator system, informally named the Big Dish that produces superheated steam via a receiver mounted monotube boiler connected to 50kWe steam engine for electricity generation. This paper describes an investigation of the system and its components modelled using the TRNYSYS transient system simulation package. The system was modelled in the context of performance assessment for multiple dishes, central generation Rankine cycle power plants. Five new custom components; paraboloidal dish collector, steam cavity receiver, steam line or feedwater line, steam engine, and pressure drop calculator, were developed for the TRNSYS deck file constructed for this study. Validation tests were performed by comparing with the latest experimental results measured with a 1-minute time step and good agreement, with errors less than 10%, has been found. (Author)

  11. A special dish from traditional Turkish Cuisine: Stuffed lamb ribs

    Directory of Open Access Journals (Sweden)

    Emel Memis Kocaman

    2015-11-01

    Full Text Available Turkish people, who have a long historical background, have a rich culture in terms of cuisine. “Dolma” (meal made by stuffing/wrapping is one of the most important dishes of the Turkish Cuisine. Turks produced very different types of meals made by stuffing or wrapping and by combining herbals, meat and offals products. Stuffed Lamb Ribs (in Turkish; Kaburga Dolması or Sura is a special dish that is known in many regions of Turkey. Since it is a dish whose preparation is hard and requires virtuosity, it is generally cooked as a feast meal on religious holidays, and commonly cooked on the Feast of Sacrifice for Muslims. This study aims to present how “Stuffed Lamb Ribs” are prepared, which is one of the traditional dishes of Turkish Cuisine and is one stuffed dish that has started to become forgotten. In this study, the data was collected by personal interviews with source people who are over 60 years old, live in different provinces of Turkey, and traditionally cook this dish. This study ensures the promotion of a very special taste, which has begun to be forgotten and is not known widely even in Turkey, at an international level.

  12. Mechanical design of a low cost parabolic solar dish concentrator

    Directory of Open Access Journals (Sweden)

    Hamza Hijazi

    2016-03-01

    Full Text Available The objective of this research was to design a low cost parabolic solar dish concentrator with small-to moderate size for direct electricity generation. Such model can be installed in rural areas which are not connected to governmental grid. Three diameters of the dish; 5, 10 and 20 m are investigated and the focal point to dish diameter ratio is set to be 0.3 in all studied cases. Special attention is given to the selection of the appropriate dimensions of the reflecting surfaces to be cut from the available sheets in the market aiming to reduce both cutting cost and sheets cost. The dimensions of the ribs and rings which support the reflecting surface are optimized in order to minimize the entire weight of the dish while providing the minimum possible total deflection and stresses in the beams. The study applies full stress analysis of the frame of the dish using Autodesk Inventor. The study recommends to use landscape orientation for the reflective facets and increase the ribs angle and the distance between the connecting rings. The methodology presented is robust and can be extended to larger dish diameters.

  13. Accurate Complex Systems Design: Integrating Serious Games with Petri Nets

    Directory of Open Access Journals (Sweden)

    Kirsten Sinclair

    2016-03-01

    Full Text Available Difficulty understanding the large number of interactions involved in complex systems makes their successful engineering a problem. Petri Nets are one graphical modelling technique used to describe and check proposed designs of complex systems thoroughly. While automatic analysis capabilities of Petri Nets are useful, their visual form is less so, particularly for communicating the design they represent. In engineering projects, this can lead to a gap in communications between people with different areas of expertise, negatively impacting achieving accurate designs.In contrast, although capable of representing a variety of real and imaginary objects effectively, behaviour of serious games can only be analysed manually through interactive simulation. This paper examines combining the complementary strengths of Petri Nets and serious games. The novel contribution of this work is a serious game prototype of a complex system design that has been checked thoroughly. Underpinned by Petri Net analysis, the serious game can be used as a high-level interface to communicate and refine the design.Improvement of a complex system design is demonstrated by applying the integration to a proof-of-concept case study.   

  14. An Introduction to the Practical Use of Coloured Petri Nets

    DEFF Research Database (Denmark)

    Jensen, Kurt

    1998-01-01

    The development of Coloured Petri Nets (CP-nets or CPN) has been driven by the desire to develop a modelling language - at the same time theoretically well-founded and versatile enough to be used in practice for systems of the size and complexity found in typical industrial projects. To achieve t...

  15. CPN Tools for Editing, Simulating, and Analysing Coloured Petri Nets

    DEFF Research Database (Denmark)

    Ratzer, Anne Vinter; Wells, Lisa Marie; Lassen, Henry Michael

    2003-01-01

    CPN Tools is a tool for editing, simulating and analysing Coloured Petri Nets. The GUI is based on advanced interaction techniques, such as toolglasses, marking menus, and bi-manual interaction. Feedback facilities provide contextual error messages and indicate dependency relationships between net...

  16. Coloured Petri Net Refinement Specification and Correctness Proof with Coq

    Science.gov (United States)

    Choppy, Christine; Mayero, Micaela; Petrucci, Laure

    2009-01-01

    In this work, we address the formalisation of symmetric nets, a subclass of coloured Petri nets, refinement in COQ. We first provide a formalisation of the net models, and of their type refinement in COQ. Then the COQ proof assistant is used to prove the refinement correctness lemma. An example adapted from a protocol example illustrates our work.

  17. Reachability Trees for High-level Petri Nets

    DEFF Research Database (Denmark)

    Jensen, Kurt; Jensen, Arne M.; Jepsen, Leif Obel;

    1986-01-01

    the necessary analysis methods. In other papers it is shown how to generalize the concept of place- and transition invariants from place/transition nets to high-level Petri nets. Our present paper contributes to this with a generalization of reachability trees, which is one of the other important analysis...

  18. A Petri Net Definition of a System Description Language

    DEFF Research Database (Denmark)

    Jensen, Kurt; Kyng, Morten; Madsen, Ole Lehrmann

    1979-01-01

    This paper introduces a language for the description of systems with concurrency, and presents a formal definition of its semantics. The language is based on Delta and the semantic model is an extension of Petri nets with a data part and with expressions attached to transitions and to places....

  19. Timed-Arc Petri Nets vs. Networks of Timed Automata

    DEFF Research Database (Denmark)

    Srba, Jiri

    requirement and provide efficient (polynomial time) reductions between networks of timed automata and 1-safe timed-arc Petri nets preserving the answer to the reachability question. This makes our techniques suitable for automatic translation into a format required by tools like UPPAAL and KRONOS. A direct...

  20. Finite petri nets as models for recursive causal behaviour

    NARCIS (Netherlands)

    Goltz, Ursula; Rensink, Arend

    1994-01-01

    Goltz (1988) discussed whether or not there exist finite Petri nets (with unbounded capacities) modelling the causal behaviour of certain recursive CCS terms. As a representative example, the following term is considered: B=(a.nil | b.B)+c.nil. We will show that the answer depends on the chosen

  1. Fluid Survival Tool: A Model Checker for Hybrid Petri Nets

    NARCIS (Netherlands)

    Postema, Björn; Remke, Anne; Haverkort, Boudewijn R.; Ghasemieh, Hamed

    2014-01-01

    Recently, algorithms for model checking Stochastic Time Logic (STL) on Hybrid Petri nets with a single general one-shot transition (HPNG) have been introduced. This paper presents a tool for model checking HPNG models against STL formulas. A graphical user interface (GUI) not only helps to demonstra

  2. Petri net based modeling and analysis for weldingflexible manufacturing cell

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    Due to the development of advanced manufacturing technology and the introduction of Smart-Manufacturing notion in the field of modern industrial production, welding flexible manufacturing using robot technology has become the inevitable developing direction on welding automation. Based on a new intelligent arc-welding flexible manufacturing cell (WFMC), its system structure and control policies are studied in this paper. Aiming at the different information flows among every subsystem and central monitoring computer in this WFMC, Petri net theory is introduced into the process of welding manufacturing. A discrete control model of WFMC has been constructed, in which the system’s status is regarded as place and the control process is regarded as transition. Moreover, grounded on automation Petri net principle, the judging and utilizing of information obtained from welding sensors are imported into Petri net structure, which extends the traditional Petri net concepts. The control model and policies researched in this paper have established foundation for further intelligent real-time control on welding flexible manufacturing cell and system.

  3. [Typical dishes consumed in Sonora: regionalization and nutrient contribution].

    Science.gov (United States)

    Jardines, R P; Bermúdez, M C; Wong, P; León, G

    1985-12-01

    This study deals with the development of a method to identify typical food dishes, successfully applied in the State of Sonora, Mexico. The State was divided into six regions considering the size of the territory and existence of different physical, economic and sociocultural conditions, and how they influence the consumption patterns. A list of 66 regional food dishes was prepared by interviewing housewives from different parts of Sonora who now lived in the city of Hermosillo. From this list, 47 dishes were identified as regionally consumed, and a State-wide survey was performed to determine their frequency of consumption. Based on the categories of "very frequently", "frequently" and "less frequently", a group of 15 dishes (2 per region, plus 3 dishes throughout the State) was selected. A questionnaire was used to obtain the different ways they had of preparing them. The "typical recipe" for each dish was also determined, using the mode as statistical parameter. Samples of these food dishes were prepared at the laboratory following the selected home recipes for proximal analysis and determination of their vitamin A, thiamine, riboflavin, niacin, calcium, phosphorus and iron content. The results showed that a portion of "gallina pinta" contributed more than 25% of the daily recommended intake established by the National Institute of Nutrition "Salvador Zubirán" (INNSZ) for an adult man for energy, protein, iron, niacin and 24.3% thiamine and 21.0% calcium. The "chivichangas de queso", for example, contributed 45.2% of the calcium requirement, and the "tamales de carne", 36% iron.(ABSTRACT TRUNCATED AT 250 WORDS)

  4. Facet development for a faceted stretched-membrane dish by Solar Kinetics, Inc

    Energy Technology Data Exchange (ETDEWEB)

    Schertz, P.T.; Brown, D.C.; Konnerth, A. III (Solar Kinetics, Inc., Dallas, TX (United States))

    1991-07-01

    A 3.6-meter diameter stretched-membrane optical facet for a parabolic dish has been successfully designed and demonstrated under contract with Sandia National Laboratories. Twelve facets identical to them will be used to make the lightweight reflector of the dish. The project goal of 2.5-mrad surface accuracy was met with each of the two full-sized prototypes, and accuracies of as low as 1.1 mrad were achieved. The facet weight is 11.7 kg/m{sup 2} (2.4lbs/ft{sup 2}). The facet is similar in construction to the successful stretched-membrane heliostat; it has two thin metal membranes attached to a ring. However, the front membrane for this facet is plastically formed at the factor in order to achieve a shorter facet f/D (approximately 3.0). A passive tether restrains the from membrane when not in operation, that is, when the stabilizing vacuum is off. The optical surface is achieved with a silvered-acrylic film laminated to the metal membrane. The facet is expected to cost $55.40/m{sup 2} at a production rate of 10,000 facets per year and $115, 000/m{sup 2}-at a production rate of 500 facets a year. Several key issues have been resolved. Stress concentrations due to seams in the reflective laminate did not cause membrane rupture during forming as they have for dishes with lower focal length-to-diameter ratios. The laminate survived the forming process and simulated operation without deterioration. The optical effect of the tether on the membrane was tested and found to be very small. Most important, highly accurate shapes were obtained using a simple forming procedure. Additional tests are needed to demonstrate process repeatablility and facet performance in typical operating conditions. 18 refs., 36 figs., 11 tabs.

  5. Facet development for a faceted stretched-membrane dish by Solar Kinetics, Inc.

    Science.gov (United States)

    Schertz, P. T.; Brown, D. C.; Konnerth, A., III

    1991-07-01

    A 3.6-meter diameter stretched-membrane optical facet for a parabolic dish has been successfully designed and demonstrated under contract with Sandia National Laboratories. Twelve facets identical to them will be used to make the lightweight reflector of the dish. The project goal of 2.5-mrad surface accuracy was met with each of the two full-sized prototypes, and accuracies of as low as 1.1 mrad were achieved. The facet weight is 11.7 kg/sq m (2.4 lbs/sq ft). The facet is similar in construction to the successful stretched-membrane heliostat; it has two thin metal membranes attached to a ring. However, the front membrane for this facet is plastically formed at the factor in order to achieve a shorter facet f/D (approximately 3.0). A passive tether restrains the front membrane when not in operation, that is, when the stabilizing vacuum is off. The optical surface is achieved with a silvered-acrylic film laminated to the metal membrane. The facet is expected to cost $55.40/sq m at a production rate of 10,000 facets per year and $115,000/sq m at a production rate of 500 facets a year. Several key issues have been resolved. Stress concentrations due to seams in the reflective laminate did not cause membrane rupture during forming as they have for dishes with lower focal length-to-diameter ratios. The laminate survived the forming process and simulated operation without deterioration. The optical effect of the tether on the membrane was tested and found to be very small. Most important, highly accurate shapes were obtained using a simple forming procedure. Additional tests are needed to demonstrate process repeatability and facet performance in typical operating conditions.

  6. Fifth parabolic dish solar thermal power program annual review: proceedings

    Energy Technology Data Exchange (ETDEWEB)

    None

    1984-03-01

    The primary objective of the Review was to present the results of activities within the Parabolic Dish Technology and Module/Systems Development element of the Department of Energy's Solar Thermal Energy Systems Program. The Review consisted of nine technical sessions covering overall Project and Program aspects, Stirling and Brayton module development, concentrator and engine/receiver development, and associated hardware and test results to date; distributed systems operating experience; international dish development activities; and non-DOE-sponsored domestic dish activities. A panel discussion concerning business views of solar electric generation was held. These Proceedings contain the texts of presentations made at the Review, as submitted by their authors at the beginning of the Review; therefore, they may vary slightly from the actual presentations in the technical sessions.

  7. Technical status of the Dish/Stirling Joint Venture Program

    Science.gov (United States)

    Bean, John R.; Diver, Richard B.

    Initiated in 1991; the Dish/Stirling Joint Venture Program (DSJVP) is a 5-year, $17.2 million joint venture which is funded by Cummins Power Generation, Inc. (CPG) of Columbus, Indiana and the United States Department of Energy's (DOE) Solar Thermal and Biomass Power Division. Sandia National Laboratories administers and provides technical management for this contract on the DOE's behalf. In January, 1995; CPG advanced to Phase 3 of this three-phase contract. The objective of the DSJVP is to develop and commercialize a 7-kW. Dish/Stirling System for remote power markets by 1997. In this paper, the technical status of the major subsystems which comprise the CPG 7-kW(sub e) Dish/Stirling System is presented. These subsystems include the solar concentrator, heat pipe receiver, engine/alternator, power conditioning, and automatic controls.

  8. Experiments on the dish verification antenna china for the SKA

    Science.gov (United States)

    Chai, Xiaoming; Liu, Bin; Yu, Lei; Yu, Shenghua; Wu, Di; Liu, Lijia

    2016-12-01

    The Square Kilometre Array (SKA) is expected to become the world's most powerful radio telescope at meter and centimeter wavelength in the coming decades. The construction of SKA will be divided into two phases. The first phase (SKA1), scheduled for completion in 2023, will construct 10 % of the whole collecting area. The second phase (SKA2) will build the rest 90 % collecting area. The SKA1 consists of several types of arrays including SKA1-low and SKA1-mid. The latter is a dish array consisting of 200 medium-size antennas. The integrated dish array in SKA2 will expand to 2500 dishes, spreading 3000 kilometers across the southern part of Africa. The demanding specifications and enormous number of the SKA dish raise challenges in the dish development such as mass production with high performance at low cost, quick installation and high reliability. Dish Verification Antenna China (DVA-C) was built as one of three initial prototypes. A novel single-piece panel reflector made of carbon fiber reinforced polymer (CFRP) was adopted. In this study, an L-band receiver is installed to make DVA-C a complete system for experiments on antenna performance test and preliminary observations. The performance of DVA-C including the system noise temperature, pointing accuracy, antenna pattern, and aperture efficiency has been tested. Preliminary observations such as pulsars and HI are then conducted, which indicates that the DVA-C can not only serve as an educational instrument and key technology test bed, but also be applied for scientific work such as pulsar timing, all-sky HI survey, multi-frequency monitoring of variable sources etc.

  9. Experiments on the dish verification antenna china for the SKA

    Science.gov (United States)

    Chai, Xiaoming; Liu, Bin; Yu, Lei; Yu, Shenghua; Wu, Di; Liu, Lijia

    2016-09-01

    The Square Kilometre Array (SKA) is expected to become the world's most powerful radio telescope at meter and centimeter wavelength in the coming decades. The construction of SKA will be divided into two phases. The first phase (SKA1), scheduled for completion in 2023, will construct 10 % of the whole collecting area. The second phase (SKA2) will build the rest 90 % collecting area. The SKA1 consists of several types of arrays including SKA1-low and SKA1-mid. The latter is a dish array consisting of ~200 medium-size antennas. The integrated dish array in SKA2 will expand to 2500 dishes, spreading 3000 kilometers across the southern part of Africa. The demanding specifications and enormous number of the SKA dish raise challenges in the dish development such as mass production with high performance at low cost, quick installation and high reliability. Dish Verification Antenna China (DVA-C) was built as one of three initial prototypes. A novel single-piece panel reflector made of carbon fiber reinforced polymer (CFRP) was adopted. In this study, an L-band receiver is installed to make DVA-C a complete system for experiments on antenna performance test and preliminary observations. The performance of DVA-C including the system noise temperature, pointing accuracy, antenna pattern, and aperture efficiency has been tested. Preliminary observations such as pulsars and HI are then conducted, which indicates that the DVA-C can not only serve as an educational instrument and key technology test bed, but also be applied for scientific work such as pulsar timing, all-sky HI survey, multi-frequency monitoring of variable sources etc.

  10. Modeling of Testability Requirement Based on Generalized Stochastic Petri Nets

    Institute of Scientific and Technical Information of China (English)

    SU Yong-ding; QIU Jing; LIU Guan-jun; QIAN Yan-ling

    2009-01-01

    Testability design is an effective way to realize the fault detection and isolation. Its important step is to determine testability figures of merits (TFOM). Firstly, some influence factors for TFOMs are analyzed, such as the processes of system operation, maintenance and support, fault detection and isolation and so on. Secondly, a testability requirement analysis model is built based on generalized stochastic Petri net (GSPN). Then, the system's reachable states are analyzed based on the model, a Markov chain isomorphic with Petri net is constructed, a state transition matrix is created and the system's steady state probability is obtained. The relationship between the steady state availability and testability parameters can be revealed and reasoned. Finally, an example shows that the proposed method can determine TFOM, such as fault detection rate and fault isolation rate, effectively and reasonably.

  11. Knowledge base verification based on enhanced colored petri net

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Jong Hyun; Seong, Poong Hyun [Korea Advanced Institute of Science and Technology, Taejon (Korea, Republic of)

    1997-12-31

    Verification is a process aimed at demonstrating whether a system meets it`s specified requirements. As expert systems are used in various applications, the knowledge base verification of systems takes an important position. The conventional Petri net approach that has been studied recently in order to verify the knowledge base is found that it is inadequate to verify the knowledge base of large and complex system, such as alarm processing system of nuclear power plant. Thus, we propose an improved method that models the knowledge base as enhanced colored Petri net. In this study, we analyze the reachability and the error characteristics of the knowledge base and apply the method to verification of simple knowledge base. 8 refs., 4 figs. (Author)

  12. Code Generation from Pragmatics Annotated Coloured Petri Nets

    DEFF Research Database (Denmark)

    Simonsen, Kent Inge

    implemented in a prototype tool called PetriCode. We defined several criteria for our code generation approach, the approach should be scalable so that is can be used to generate code for industrial sized protocols. The models should be verifiable and it should be possible to perform efficient verification...... the PA-CPN model that describe the protocol design. The generated code is also shown to be readable and we demonstrate that a generated implementation can be easily integrated with third party software. We also show that our approach scales to industrial sized protocols by applying our approach......All electronic communication relies on communication protocols. It is therefore very important that protocols are correct and that protocol implementations are reliable. Coloured Petri Nets (CPNs) have been widely used to model, analyse and verify communication protocols. However, relatively...

  13. Dynamic properties of fuzzy Petri net model and related analysis

    Institute of Scientific and Technical Information of China (English)

    周恺卿; Azlan Mohd Zain; 莫礼平

    2015-01-01

    Fuzzy Petri net (FPN) has been extensively applied in industrial fields for knowledge-based systems or systems with uncertainty. Although the applications of FPN are known to be successful, the theoretical research of FPN is still at an initial stage. To pave a way for further study, this work explores related dynamic properties of FPN including reachability, boundedness, safeness, liveness and fairness. The whole methodology is divided into two phases. In the first phase, a comparison between elementary net system (EN_system) and FPN is established to prove that the FPN is an extensive formalism of Petri nets using a backwards-compatible extension method. Next, current research results of dynamic properties are utilized to analyze FPN model. The results illustrate that FPN model is bounded, safe, weak live and fair, and can support theoretical evidences for designing related decomposition algorithm.

  14. Petri net and beam search based FMS scheduling system

    Energy Technology Data Exchange (ETDEWEB)

    Shih, H.; Sekiguchi, T. (Yokohama National University, Yokohama (Japan))

    1992-04-15

    The present paper proposes an on-line flexible manufacturing system (FMS) scheduling system which takes in consideration the routing flexibility. The FMS was modeled by utilizing a timed Petri net representation. This representation gives real time information about the production evolvement and the situation of each machine and equipment. According to this information, the present system starts to search for the scheduling of the next orders to be assigned. The search is conducted by a beam search based on-line decision method. An algorithm has been developed by integrating the timed Petri net representation to the beam search. In order to test the developed system, a just-in-time production objective was established. The performance of this system was evaluated by exhaustive simulations. Consequently, a better achievement of the production objective as well as a smaller variance under different scheduling conditions can be realized. 14 refs., 6 figs., 2 tabs.

  15. Modeling and evaluation of information systems using coloured petri network

    Directory of Open Access Journals (Sweden)

    Ehsan Zamirpour

    2014-07-01

    Full Text Available Nowadays with the growth of organizations and their affiliates, the importance of information systems has increased. Functional and non-functional requirements of information systems in an organization are supported. There are literally several techniques to support the functional requirements in terms of software methodologies, but support for the second set of requirements has received little attention. Software Performance Engineering (SPE forum tries to address this issue by presenting software methodologies to support both types of requirements. In this paper, we present a formal model for the evaluation of system performance based on a pragmatic model. Because of supporting the concurrency concepts, petri net has a higher priority than queuing system. For mapping UML to colored Petri net diagram, we use an intermediate graph. The preliminary results indicate that the proposed model may save significant amount of computations.

  16. ANALYSIS OF A TRANSPORT PROCESS USING HYBRID PETRI NETS

    Directory of Open Access Journals (Sweden)

    Elisabeta Mihaela CIORTEA

    2013-05-01

    Full Text Available Purpose of the paper is to analyze the Petri net model, to describe the transport process, part of amanufacturing system and its dynamics.A hibrid Petri net model is built to describe the dinamics of the transport process manufacturingsystem. Mathematical formulation of the dinamycs processes a detailed description. Based on this model, theanalysis of the transport process is designed to be able to execute a production plan and resolve any conflictsthat may arise in the system.In the analysis dinamics known two stages: in the continuous variables are discrete hybrid system in thehibrid discrete variables are used as safety control with very well defined responsibilities.In terms of the chosen model, analyze transport process is designed to help execute a production planand resolve conflicts that may arise in the process, and then the ones in the system

  17. Virtual Control Policy for Binary Ordered Resources Petri Net Class

    Directory of Open Access Journals (Sweden)

    Carlos A. Rovetto

    2016-08-01

    Full Text Available Prevention and avoidance of deadlocks in sensor networks that use the wormhole routing algorithm is an active research domain. There are diverse control policies that will address this problem being our approach a new method. In this paper we present a virtual control policy for the new specialized Petri net subclass called Binary Ordered Resources Petri Net (BORPN. Essentially, it is an ordinary class constructed from various state machines that share unitary resources in a complex form, which allows branching and joining of processes. The reduced structure of this new class gives advantages that allow analysis of the entire system’s behavior, which is a prohibitive task for large systems because of the complexity and routing algorithms.

  18. Interactive Multimedia Synchronization Model Based on Petri Nets

    Institute of Scientific and Technical Information of China (English)

    WANG Zhiqiang; PENG Xiaogang; JI Zhen

    2007-01-01

    The multimedia synchronization is used to coordinate the timing of each multimedia object in the multimedia system.After studying different multimedia synchronization systems that have been published, an Interactive Synchronization multimedia based on Petri Nets model (ISPN) is proposed in this paper. The system is capable of describing the dynamic timing actions of multimedia objects vividly as well as controlling them interactively to maintain the system level synchronization balance.

  19. Automatic Structure-Based Code Generation from Coloured Petri Nets

    DEFF Research Database (Denmark)

    Kristensen, Lars Michael; Westergaard, Michael

    2010-01-01

    Automatic code generation based on Coloured Petri Net (CPN) models is challenging because CPNs allow for the construction of abstract models that intermix control flow and data processing, making translation into conventional programming constructs difficult. We introduce Process-Partitioned CPNs....... The viability of our approach is demonstrated by applying it to automatically generate an Erlang implementation of the Dynamic MANET On-demand (DYMO) routing protocol specified by the Internet Engineering Task Force (IETF)....

  20. Resarch on Welding Robotic System with Petri Net

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    Petri net (PN) theory model was adopted for complexity in welding flexible manufacturing system (WFMS). A scheduling arithmetic was devised to optimize the process of controlling system. With this scheduling way, model simulation experiment was designed to validate the model. And a sort of controlling software was designed on local net. Besides, a special welding experiment had been designed to check the controlling way. Results show the controlling process rightly and feasibly.

  1. Properties of Distributed Timed-Arc Petri Nets

    DEFF Research Database (Denmark)

    Nielsen, M.; Sassone, V.; Srba, J.

    2001-01-01

    In [12] we started a research on a distributed-timed extension of Petri nets where time parameters are associated with tokens and arcs carry constraints that qualify the age of tokens required for enabling. This formalism enables to model e.g. hardware architectures like GALS. We give a formal de...... definition of process semantics for our model and investigate several properties of local versus global timing: expressiveness, reachability and coverability....

  2. Maximality-Based Structural Operational Semantics for Petri Nets

    Science.gov (United States)

    Saīdouni, Djamel Eddine; Belala, Nabil; Bouneb, Messaouda

    2009-03-01

    The goal of this work is to exploit an implementable model, namely the maximality-based labeled transition system, which permits to express true-concurrency in a natural way without splitting actions on their start and end events. One can do this by giving a maximality-based structural operational semantics for the model of Place/Transition Petri nets in terms of maximality-based labeled transition systems structures.

  3. Timed Test Case Generation Using Labeled Prioritized Time Petri Nets

    OpenAIRE

    Noureddine Adjir; Pierre De Saqui Sannes; Kamel Rahmouni; Abdelkader Adla

    2012-01-01

    Model-based testing of software and hardware systems uses behavioral and formal models of the systems. The paper presents a technique for model-based black-box conformance testing of real-time systems using Labeled Prioritized Time Petri Nets (LPrTPN). The Timed Input/Output Conformance (tioco) relation, which takes environment assumptions into account, serves as reference to decide of implementation correctness. Test suites are derived automatically from a LPrTPN made up of two concurrent su...

  4. Petri net model for analysis of concurrently processed complex algorithms

    Science.gov (United States)

    Stoughton, John W.; Mielke, Roland R.

    1986-01-01

    This paper presents a Petri-net model suitable for analyzing the concurrent processing of computationally complex algorithms. The decomposed operations are to be processed in a multiple processor, data driven architecture. Of particular interest is the application of the model to both the description of the data/control flow of a particular algorithm, and to the general specification of the data driven architecture. A candidate architecture is also presented.

  5. Using Coloured Petri Nets for design of parallel raytracing environment

    CERN Document Server

    Korecko, Stefan

    2010-01-01

    This paper deals with the parallel raytracing part of virtual-reality system PROLAND, developed at the home institution of authors. It describes an actual implementation of the raytracing part and introduces a Coloured Petri Nets model of the implementation. The model is used for an evaluation of the implementation by means of simulation-based performance analysis and also forms the basis for future improvements of its parallelization strategy.

  6. Petri nets extension to model state-varying failure rates

    DEFF Research Database (Denmark)

    Lazarova-Molnar, Sanja

    2013-01-01

    One of the most common assumptions in reliability modeling is the constant failure rate. This has been increasingly changing lately, yielding significant research towards abandoning simulation results based on this assumption; thus, deeming constant failure rates as inadequate to model failures......-varying failure rates and extend the formalism of Petri nets to model them. To illustrate our approach we provide an example model that features state-varying failure rates....

  7. A Network Attack Model based on Colored Petri Net

    Directory of Open Access Journals (Sweden)

    Xinlei Li

    2014-07-01

    Full Text Available The researches have shown that not all the Petri Net machines can be used to describe attack behavior. When Petri Net machines adapted for attack behavior modeling are detecting the network, for some event of current status, if there is matching event in the model, it has only one corresponding transition; otherwise that may cause errors. Since sharing synthesis and synchronization synthesis of traditional machines cannot ensure synthetic model reserves original detection capability, we propose the novel concept for synthesis operation and colored synthetic operation. By the analysis on the relation among these operations, the ability to reserve original detection is verified. Then an improved colored judgement Petri Net machine is adopted for modeling and renewing the knowledge repository. The inductive learning method is used to extend the attack modes. It creates a four-layered concept space, which actually provides a depth-first search path for matching. To solve the problems in multi-pattern matching and incremental learning, various modes are generalized by colored operation. We also adopt the decomposition and synthesis operation to handle the pattern matching of distributed attack behavior and attack information fusion. Finally the actual cases verify that our algorithm is feasible

  8. Fuzzy Timing Petri Net for Fault Diagnosis in Power System

    Directory of Open Access Journals (Sweden)

    Alireza Tavakholi Ghainani

    2012-01-01

    Full Text Available A model-based system for fault diagnosis in power system is presented in this paper. It is based on fuzzy timing Petri net (FTPN. The ordinary Petri net (PN tool is used to model the protective components, relays, and circuit breakers. In addition, fuzzy timing is associated with places (token/transition to handle the uncertain information of relays and circuits breakers. The received delay time information of relays and breakers is mapped to fuzzy timestamps, π(τ, as initial marking of the backward FTPN. The diagnosis process starts by marking the backward sub-FTPNs. The final marking is found by going through the firing sequence, σ, of each sub-FTPN and updating fuzzy timestamp in each state of σ. The final marking indicates the estimated fault section. This information is then in turn used in forward FTPN to evaluate the fault hypothesis. The FTPN will increase the speed of the inference engine because of the ability of Petri net to describe parallel processing, and the use of time-tag data will cause the inference procedure to be more accurate.

  9. VALIDATING THE BEHAVIOR OF A SUPERVISED SYSTEM USING PETRI NETS

    Directory of Open Access Journals (Sweden)

    CARLOS ARTURO PARRA ORTEGA

    2012-01-01

    Full Text Available Un aspecto fundamental de los sistemas de producción es la validación de su comportamiento. Paraobtener este comportamiento, se recurre frecuentemente a modelos matemáticos tales como redes de Petri, con el fin de validar su comportamiento concurrente, presencia/ausencia de bloqueos, y sincronización de actividades, entre otros aspectos. A pesar de sus ventajas, el uso de redes de Petri no permite evaluar otros aspectos que son importantes en los procesos de manufactura, así como su gestión. Por tal motivo se recurre a la simulación de sistemas estocásticos y a la tecnología de agentes para obtener otros índices de desempeño. En este artículo se propone una combinación de redes de Petri, sistemas multi-agentes y sistemas estocásticos en un método propuesto para validar el comportamiento de los sistemas de producción, y se presenta como este método es usado en un ejemplo académico de manufactura.

  10. Plastic Surgery

    Science.gov (United States)

    ... Surgery? A Week of Healthy Breakfasts Shyness Plastic Surgery KidsHealth > For Teens > Plastic Surgery Print A A ... forehead lightened with a laser? What Is Plastic Surgery? Just because the name includes the word "plastic" ...

  11. Coloured Petri Nets and CPN Tools for Modelling and Validation of Concurrent Systems

    DEFF Research Database (Denmark)

    Jensen, Kurt; Kristensen, Lars Michael; Wells, Lisa Marie

    2007-01-01

    Coloured Petri Nets (CPNs) is a language for the modeling and validation og systems in which concurrency, communication, and synchronisation play a major role. Coloured Petri Nets is a descrete-event modeling language combining Petri Nets with the funcitonal programming language Standard ML. Petr...... with user-defined Standard ML functions. A license for CPN Tools can be obtained free of charge, also for commercial use....

  12. The HERA Dish II: Electromagnetic Simulations and Science Implications

    CERN Document Server

    Ewall-Wice, Aaron; DeBoer, David; Hewitt, Jacqueline; Parsons, Aaron; Aguirre, James; Ali, Zaki S; Bowman, Judd; Cheng, Carina; Neben, Abraham R; Patra, Nipanjana; Thyagarajan, Nithyanandan; Venter, Mariet; Acedo, Eloy de Lera; Dillon, Joshua S; Doolittle, Roger; Egan, Dennis; Hendrick, Mike; Klima, Patricia; Kohn, Saul; Schaffner, Patrick; Shelton, John; Saliwanchik, Benjamin; Tegmark, Max; Taylor, H A; Taylor, Rusty; Wirt, Butch

    2016-01-01

    We use time-domain electromagnetic simulations to assess the spectral characteristics of the dish antenna for the Hydrogen Epoch of Reionization Array (HERA). These simulations are part of a multi-faceted campaign to determine the effectiveness of the dish's design for obtaining a detection of redshifted 21 cm emission from the epoch of reionization. Our simulations show the existence of reflections between HERA's suspended feed and its parabolic dish reflector, at certain frequencies, with an amplitude of roughly $ -35$dB at 100 ns which can lead to some loss of measurable modes and a modest reduction in sensitivity. Even in the presence of this structure, we find that the spectral response of the dish is sufficiently smooth for delay filtering, a proven foreground isolation technique, to contain foreground emission at line-of-sight wave numbers below $k_\\parallel \\lesssim 0.2h$Mpc$^{-1}$, in the region where the current PAPER experiment operates. Incorporating these results into a Fisher Matrix analysis, we...

  13. Toward a Representation of Hybrid Functional Petri Nets by MP Systems

    Science.gov (United States)

    Castellini, Alberto; Franco, Giuditta; Manca, Vincenzo

    In this work we analyse and compare Hybrid Functional Petri Nets [10], an extension of Petri Nets [12] for biopathways simulation, and Metabolic P Systems [8,9]. An introduction to both of them is given, together with highlights about respective similarities and differences for biopathways modelling. The case study of glycolytic pathway with the lac operon gene regulatory mechanism was modeled by traditional Petri Nets in [6] and recently by Hybrid Functional Petri Nets in [10,4]. This model is here mapped into an MP system having the same dynamics.

  14. On Transforming Business Patterns to Labeled Petri Nets Using Graph Grammars

    Directory of Open Access Journals (Sweden)

    Karima Mahdi

    2013-01-01

    Full Text Available In this work we present an approach and a tool for transforming business patterns to labelled Petri nets. This transformation is justified by the fact that Petri nets have efficient analysis techniques. We specify first, business patterns and labelled Petri nets Meta-Models in UML Class Diagram formalism with the Meta-Modelling tool Atom3, and then we generate visual modelling tools according to the proposed Meta-Models. Finally, we define a graph grammar which transforms Business Patterns models to Labelled Petri Nets model for analysis purposes. The approach is illustrated with examples.

  15. Pragmatics Annotated Coloured Petri Nets for Protocol Software Generation and Verification

    DEFF Research Database (Denmark)

    Simonsen, Kent Inge; Kristensen, Lars Michael; Kindler, Ekkart

    This paper presents the formal definition of Pragmatics Annotated Coloured Petri Nets (PA-CPNs). PA-CPNs represent a class of Coloured Petri Nets (CPNs) that are designed to support automated code genera-tion of protocol software. PA-CPNs restrict the structure of CPN models and allow Petri net...... elements to be annotated with so-called pragmatics, which are exploited for code generation. The approach and tool for gen-erating code is called PetriCode and has been discussed and evaluated in earlier work already. The contribution of this paper is to give a formal def-inition for PA-CPNs; in addition...

  16. Combined Heat & Power Using the Infinia Concentrated Solar - CHP PowerDish System

    Science.gov (United States)

    2013-08-01

    installed cost as the PowerDish CHP system). The solar thermal system selected and installed will be a low or medium-temperature collector system...implementing the PowerDish CHP. ...................................... 29 Table 8. Important costs for implementing the PowerDish CHP versus PV- solar thermal ...capabilities of the Infinia PowerDish CHP technology to generate clean solar electricity as well as thermal energy for domestic hot water and space

  17. An Analysis Method of Petri Nets Based on Linear Logic%一种基于线性逻辑的Petri网分析方法

    Institute of Scientific and Technical Information of China (English)

    高梅梅; 吴智铭

    2000-01-01

    The paper presents a translation from Petri nets to linear logic with the objective ot enhancing the analysis ability of Petri nets. The definition of Petri nets is described by defining the translations in Petri nets using the connectives in linear logic,and the behavior of Petri nets is constructed using the rules we defined. The behavior of Petri nets can be described precisely and clearly using this method.

  18. Towards a Notion of Distributed Time for Petri Nets

    DEFF Research Database (Denmark)

    Nielsen, Mogens; Sassone, Vladimiro; Srba, Jiří

    2001-01-01

    We set the ground for research on a timed extension of Petri nets where time parameters are associated with tokens and arcs carry constraints that qualify the age of tokens required for enabling. The novelty is that, rather than a single global clock, we use a set of unrelated clocks — possibly o...... per place — allowing a local timing as well as distributed time synchronisation. We give a formal definition of the model and investigate properties of local versus global timing, including decidability issues and notions of processes of the respective models....

  19. Stability Analysis of Buffer Priority Scheduling Policies Using Petri Nets

    Institute of Scientific and Technical Information of China (English)

    LIN Chuang(林闯); XU MingWei(徐明伟)

    2003-01-01

    A Petri net approach to determining the conditions for stability of a re-entrantsystem with buffer priority scheduling policy is described in this paper. The concept of bufferboundedness based on the dynamic behavior of the markings in the system model is emphasized.The method is used to demonstrate the stability of the first buffer first served (FBFS) and thelast buffer first served (LBFS) scheduling policies. Finally a sufficient condition for instability ofsystems with a positive feedback loop (PFL) is established, and an example is given.

  20. Petri Net Modeling and Performance Analyzing for MGC

    Institute of Scientific and Technical Information of China (English)

    HUANGYongfeng; LIXing; ZHANGKe

    2004-01-01

    This article analyses the advantages of disassembled gateway based on its functions, and introduces the processing of signaling and media streams. Moreover, a function-separated gateway is designed and implemented, which consists of media gateway controller and media gateway. So we propose originally the Stochastic Petri-net model of media gateway controller, and educe the mathematical relationship between load of gateway controller and other factors such as rate of call initialing, delay of call setup, and delay of call release. Lastly, we summarize some important factors which affect performances of gateway, and make a conclusion that decreasing the delay of call setup will improve Media gateway controller efficiency.

  1. The  Practitioner's guide to Coloured Petri Nets

    DEFF Research Database (Denmark)

    Kristensen, Lars Michael; Christensen, Søren; Jensen, Kurt

    1998-01-01

    Coloured Petri nets (CP-nets or CPNs) provide a framework for the desing, specification, validation, and verification of systems. CP-nets have a wide range of application areas and many CPN projects have been carried out in industry, e.g., in the areas of communication protocols, operating systems......, hardware design, embedded systems, software system designs, and busness process-engineering. Design/CPN is a graphical computer tool supporting the practial use of CP-nets. The tool supports the construction, simulation, and functional and performance analysis of CPN models. the tool is used by more than...

  2. An Introduction to the Theoretical Aspects of Coloured Petri nets

    DEFF Research Database (Denmark)

    Jensen, Kurt

    1994-01-01

    other systems in which human beings and/or computers communicate by means of some more or less formal rules). The paper contains the formal definition of CP-nets and their basic concepts (e.g., the different dynamic properties such as liveness and fairness). The paper also contains a short introduction...... of data types and the manipulation of their data values. The paper does not assume that the reader has any prior knowledge of Petri nets — although such knowledge will, of course, be a help....

  3. Irrigation market for solar thermal parabolic dish systems

    Science.gov (United States)

    Habib-Agahi, H.; Jones, S. C.

    1981-01-01

    The potential size of the onfarm-pumped irrigation market for solar thermal parabolic dish systems in seven high-insolation states is estimated. The study is restricted to the displacement of three specific fuels: gasoline, diesel and natural gas. The model was developed to estimate the optimal number of parabolic dish modules per farm based on the minimum cost mix of conventional and solar thermal energy required to meet irrigation needs. The study concludes that the potential market size for onfarm-pumped irrigation applications ranges from 101,000 modules when a 14 percent real discount rate is assumed to 220,000 modules when the real discount rate drops to 8 percent. Arizona, Kansas, Nebraska, New Mexico and Texas account for 98 percent of the total demand for this application, with the natural gas replacement market accounting for the largest segment (71 percent) of the total market.

  4. Dish concentrators for solar thermal energy - Status and technology development

    Science.gov (United States)

    Jaffe, L. D.

    1981-01-01

    Comparisons are presented of point-focusing, or 'dish' solar concentrator system features, development status, and performance levels demonstrated to date. In addition to the requirements of good optical efficiency and high geometric concentration ratios, the most important future consideration in solar thermal energy dish concentrator design will be the reduction of installed and lifetime costs, as well as the materials and labor costs of production. It is determined that technology development initiatives are needed in such areas as optical materials, design wind speeds and wind loads, structural configuration and materials resistance to prolonged exposure, and the maintenance of optical surfaces. The testing of complete concentrator systems, with energy-converting receivers and controls, is also necessary. Both reflector and Fresnel lens concentrator systems are considered.

  5. PetriCode: A Tool for Template-Based Code Generation from CPN Models

    DEFF Research Database (Denmark)

    Simonsen, Kent Inge

    2014-01-01

    Code generation is an important part of model driven methodologies. In this paper, we present PetriCode, a software tool for generating protocol software from a subclass of Coloured Petri Nets (CPNs). The CPN subclass is comprised of hierarchical CPN models describing a protocol system at different...

  6. Seventh Workshop and Tutorial on Practical Use of Coloured Petri Nets and the CPN Tools

    DEFF Research Database (Denmark)

    This booklet contains the proceedings of the Seventh Workshop on Practical Use of Coloured Petri Nets and the CPN Tools, October 24-26, 2006.......This booklet contains the proceedings of the Seventh Workshop on Practical Use of Coloured Petri Nets and the CPN Tools, October 24-26, 2006....

  7. A primer on the Petri Net Markup Language and ISO/IEC 15909-2

    DEFF Research Database (Denmark)

    Hillah, L. M.; Kindler, Ekkart; Kordon, F.

    2009-01-01

    Standard, defines a transfer format for high-level nets. The transfer format defined in Part 2 of ISO/IEC 15909 is (or is based on) the \\emph{Petri Net Markup Language} (PNML), which was originally introduced as an interchange format for different kinds of Petri nets. In ISO/IEC 15909-2, however...

  8. A primer on the Petri Net Markup Language and ISO/IEC 15909-2

    DEFF Research Database (Denmark)

    Hillah, L. M.; Kindler, Ekkart; Kordon, F.

    2009-01-01

    Standard, defines a transfer format for high-level nets. The transfer format defined in Part 2 of ISO/IEC 15909 is (or is based on) the \\emph{Petri Net Markup Language} (PNML), which was originally introduced as an interchange format for different kinds of Petri nets. In ISO/IEC 15909-2, however...

  9. FPGA applications for single dish activity at Medicina radio telescopes

    Science.gov (United States)

    Bartolin, M.; Nald, G.; Mattan, A.; Maccaferr, A.; De Biagg, M.

    FPGA technologies are gaining major attention in the recent years in the field of radio astronomy. At Medicina radio telescopes, FPGAs have been used in the last ten years for a number of purposes and in this article we will take into exam the applications developed and installed for the Medicina Single Dish 32m Antenna: these range from high performance digital signal processing to instrument control developed on top of smaller FPGAs.

  10. Thermal Model of a Dish Stirling Cavity-Receiver

    OpenAIRE

    Rubén Gil; Carlos Monné; Nuria Bernal; Mariano Muñoz; Francisco Moreno

    2015-01-01

    This paper presents a thermal model for a dish Stirling cavity based on the finite differences method. This model is a theoretical tool to optimize the cavity in terms of thermal efficiency. One of the main outcomes of this work is the evaluation of radiative exchange using the radiosity method; for that purpose, the view factors of all surfaces involved have been accurately calculated. Moreover, this model enables the variation of the cavity and receiver dimensions and the materials to deter...

  11. Searching for WISPy cold dark matter with a dish antenna

    Energy Technology Data Exchange (ETDEWEB)

    Horns, Dieter [Hamburg Univ. (Germany). Inst. fuer Experimentalphysik; Jaeckel, Joerg [Heidelberg Univ. (Germany). Inst. fuer Theoretische Physik; Durham Univ. (United Kingdom). Inst. for Particle Physics Phenomenology; Lindner, Axel; Ringwald, Andreas [Deutsches Elektronen-Synchrotron (DESY), Hamburg (Germany); Lobanov, Andrei [Max-Planck-Institut fuer Radioastronomie, Bonn (Germany); Redondo, Javier [Muenchen Univ. (Germany). Arnold Sommerfeld Center; Max-Planck-Institut fuer Physik, Muenchen (Germany)

    2012-12-15

    The cold dark matter of the Universe may be comprised of very light and very weakly interacting particles, so-called WISPs. Two prominent examples are hidden photons and axion-like particles. In this note we propose a new technique to sensitively search for this type of dark matter with dish antennas. The technique is broadband and allows to explore a whole range of masses in a single measurement.

  12. Parabolic dish reflectors for solar applications approximated by simple surfaces

    OpenAIRE

    Broman, Lars; Broman, Arne

    1996-01-01

    Two different concentrating mirrors have been constructed that resemble parabolic dish reflectors. Both mirrors are made of slightly curved strips of flat, bendable material. The strips of the most simplified mirror have only large-radius circles and straight lines as boundaries. The necessary equations for making the mirrors have been derived. Also a simple way to make a stiff, lightweight frame and support for the mirror strips has been developed. Models of the mirrors have been built and s...

  13. Searching for WISPy Cold Dark Matter with a Dish Antenna

    CERN Document Server

    Horns, Dieter; Lindner, Axel; Lobanov, Andrei; Redondo, Javier; Ringwald, Andreas

    2012-01-01

    The cold dark matter of the Universe may be comprised of very light and very weakly interacting particles, so-called WISPs. Two prominent examples are hidden photons and axion-like particles. In this note we propose a new technique to sensitively search for this type of dark matter with dish antennas. The technique is broadband and allows to explore a whole range of masses in a single measurement.

  14. Irrigation market for solar-thermal parabolic-dish systems

    Energy Technology Data Exchange (ETDEWEB)

    Habib-agahi, H.; Jones, S.C.

    1981-09-01

    The potential size of the onfarm-pumped irrigation market for solar thermal parabolic dish systems in seven high-insolation states is estimated. The study is restricted to the displacement of three specific fuels: gasoline, diesel and natural gas. A model was developed to estimate the optimal number of parabolic dish modules per farm based on the minimum cost mix of conventional and solar thermal energy required to meet irrigation needs. Results indicate that the near-term market for such systems depends not only on the type of crop and method of irrigation, but also on the optimal utilization of each added module, which in turn depends on the price of conventional fuel, real discount rate, marginal cost of the solar thermal power system, local insolation level and parabolic dish system efficiency. The study concludes that the potential market size for onfarm-pumped irrigation applications ranges from 101,000 modules when a 14% real discount rate is assumed to 220,000 modules when the real discount rate drops to 8%. Arizona, Kansas, Nebraska, New Mexico and Texas account for 98% of the total demand for this application, with the natural gas replacement market accounting for the largest segment (71%) of the total market.

  15. Skull Triangles: Flinders Petrie, Race Theory and Biometrics

    Directory of Open Access Journals (Sweden)

    Debbie Challis

    2016-02-01

    Full Text Available In 1902 the Egyptian archaeologist William Matthew Flinders Petrie published a graph of triangles indicating skull size, shape and ‘racial ability’. In the same year a paper on Naqada crania that had been excavated by Petrie’s team in 1894–5 was published in the anthropometric journal Biometrika, which played an important part in the methodology of cranial measuring in biometrics and helped establish Karl Pearson’s biometric laboratory at University College London. Cicely D. Fawcett’s and Alice Lee’s paper on the variation and correlation of the human skull used the Naqada crania to argue for a controlled system of measurement of skull size and shape to establish homogeneous racial groups, patterns of migration and evolutionary development. Their work was more cautious in tone and judgement than Petrie’s pronouncements on the racial origins of the early Egyptians but both the graph and the paper illustrated shared ideas about skull size, shape, statistical analysis and the ability and need to define ‘race’. This paper explores how Petrie shared his archaeological work with a broad number of people and disciplines, including statistics and biometrics, and the context for measuring and analysing skulls at the turn of the twentieth century.

  16. Timed Test Case Generation Using Labeled Prioritized Time Petri Nets

    Directory of Open Access Journals (Sweden)

    Noureddine Adjir

    2012-03-01

    Full Text Available Model-based testing of software and hardware systems uses behavioral and formal models of the systems. The paper presents a technique for model-based black-box conformance testing of real-time systems using Labeled Prioritized Time Petri Nets (LPrTPN. The Timed Input/Output Conformance (tioco relation, which takes environment assumptions into account, serves as reference to decide of implementation correctness. Test suites are derived automatically from a LPrTPN made up of two concurrent sub-nets that respectively specify the system under test and its environment. The result is optimal in the sense that test cases have the shortest possible accumulated time to be executed. Test cases selection combines test purposes and structural coverage criteria associated with the model. A test purpose or a coverage criterion is specified in a SE-LTL formula. The TIme Petri Net Analyzer TINA has been extended to support concurrent composed subnets. Automatic generation of time-optimal test suites with the Tina toolbox combines the model checker selt and the path analyzer plan. selt outputs a sequence that satisfies the logic formula. plan computes the fastest execution of this sequence which will be transformed in a test cases suite.

  17. The methodology of multicriterial assessment of Petri nets’ apparatus

    Directory of Open Access Journals (Sweden)

    Pashchenko Dmitry

    2016-01-01

    Full Text Available This article emphasizes the effectiveness and relevance of the using of the apparatus of Petri nets for modeling of complex computing systems. Due to the fact that the methods of analysis existing in this theory do not allow estimating the resources required to build the desired model of the system, there is a problem of shortage of criteria for its evaluation in terms of the complexity of the construction. In the article we consider the method of analysis of a random Petri net based on the complexity of its building and relationships of internal units - subnets. The purpose of this article is a software implementation of such an assessment within the theory of PN structures. Due to the fact, that structural approach allows to perform the operation of decomposition of the original system, this model can be divided into subnets of minimal dimension, that will allow to make its quantitative assessment - ranking. To determine the total assessment of the input and output data of the system we will perform the analysis of head and tail positions of the net taking into account the weights of the input and output arcs of these positions. In order to identify an extent of the cost required to build the system, the number of operations of union of subnet transitions and positions. These subnets have minimal dimension in the original PN. Thus, the article demonstrates the formal implementation of assessment technique modules with using of algebra of sets, and the rules of splitting the PN structure into elementary blocks are formulated. The example of a comparative assessment of the two Petri nets based on the proposed complexity criteria is given; the plots of PN in different coordinate systems are displayed. The article presents the results of the research - a plot of PN structures in three-dimensional space, implemented using described software. It demonstrates the accuracy of PN assessment by structural analysis in comparing with a non

  18. Nondeterministic Probabilistic Petri Net — A New Method to Study Qualitative and Quantitative Behaviors of System

    Institute of Scientific and Technical Information of China (English)

    Yang Liu; Huai-Kou Miao; Hong-Wei Zeng; Yan Ma; Pan Liu

    2013-01-01

    There are many variants of Petri net at present,and some of them can be used to model system with both function and performance specification,such as stochastic Petri net,generalized stochastic Petri net and probabilistic Petri net.In this paper,we utilize extended Petri net to address the issue of modeling and verifying system with probability and nondeterminism besides function aspects.Using probabilistic Petri net as reference,we propose a new mixed model NPPN (Nondeterministic Probabilistic Petri Net) system,which can model and verify systems with qualitative and quantitative behaviours.Then we develop a kind of process algebra for NPPN system to interpret its algebraic semantics,and an actionbased PCTL (Probabilistic Computation Tree Logic) to interpret its logical semantics.Afterwards we present the rules for compositional operation of NPPN system based on NPPN system process algebra,and the model checking algorithm based on the action-based PCTL.In order to put the NPPN system into practice,we develop a friendly and visual tool for modeling,analyzing,simulating,and verifying NPPN system using action-based PCTL.The usefulness and effectiveness of the NPPN system are illustrated by modeling and model checking an elaborate model of travel arrangements workflow.

  19. An Attack Modeling Based on Colored Petri Net

    Institute of Scientific and Technical Information of China (English)

    ZHOU Shijie; QIN Zhiguang; ZHANG Feng; LIU Jinde

    2004-01-01

    A color petri net (CPN) based attack modeling approach is addressed.Compared with graph-based modeling,CPN based attack model is fiexible enough to model Intemet intrusions,because of their static and dynamic features.The processes and rules of building CPN based attack model from attack tree are also presented.In order to evaluate the risk of intrusion,some cost elements are added to CPN based attack modeling.This extended model is useful in intrusion detection and risk evaluation.Experiences show that it is easy to exploit CPN based attack modeling approach to provide the controlling functions,such as intrusion response and intrusion defense.A case study given in this paper shows that CPN based attack model has many unique characters which attack tree model hasn't.

  20. Formal Requirements Modeling for Reactive Systems with Coloured Petri Nets

    DEFF Research Database (Denmark)

    Tjell, Simon

    This dissertation presents the contributions of seven publications all concerned with the application of Coloured Petri Nets (CPN) to requirements modeling for reactive systems. The publications are introduced along with relevant background material and related work, and their contributions...... interface composed of recognizable artifacts and activities. The presentation of the three publications related to Use Cases is followed by a the presentation of a publication formalizing some of the guidelines applied for structuring the CPN requirements models|namely the guidelines that make it possible...... activity. The traces are automatically recorded during execution of the model. The second publication presents a formally specified framework for automating a large part of the tasks related to integrating Problem Frames with CPN. The framework is specified in VDM++, and allows the modeler to automatically...

  1. A Petri Net model for distributed energy system

    Energy Technology Data Exchange (ETDEWEB)

    Konopko, Joanna [Warsaw University of Technology, The Faculty of Electronics and Information Technology, Institute of Computer Science, Nowowiejska Street 15/19, Warsaw 00-665 (Poland)

    2015-12-31

    Electrical networks need to evolve to become more intelligent, more flexible and less costly. The smart grid is the next generation power energy, uses two-way flows of electricity and information to create a distributed automated energy delivery network. Building a comprehensive smart grid is a challenge for system protection, optimization and energy efficient. Proper modeling and analysis is needed to build an extensive distributed energy system and intelligent electricity infrastructure. In this paper, the whole model of smart grid have been proposed using Generalized Stochastic Petri Nets (GSPN). The simulation of created model is also explored. The simulation of the model has allowed the analysis of how close the behavior of the model is to the usage of the real smart grid.

  2. Modelling Local and Global Behaviour: Petri Nets and Event Coordination

    DEFF Research Database (Denmark)

    Kindler, Ekkart

    2011-01-01

    Today, it is possible to generate major parts of a software system from models. Most of the generated code, however, concerns the structural parts of the software; the parts that concern the functionality or behaviour of a system are still programmed manually. In order to overcome this problem, we...... are developing the concept of coordination diagrams that define the global behaviour on top of structural software models. Basically, these diagrams define how the local behaviour of an element is coordinated with the behaviour of the elements it is connected to. The exact concepts of these coordination diagrams...... and their notation is still under development, but there exists a first prototype for experimenting and for fine-tuning its features. We call it the Event Coordination Notation (ECNO). For experimenting with the ECNO, we implemented also a simple modelling notation for the local behaviour, which is based on Petri...

  3. A Coloured Petri Net Analysis of the Transaction Internet Protocol

    Science.gov (United States)

    Georgiadis, Christos K.; Kokkinidis, Ioannis; Pimenidis, Elias

    The Transaction Internet Protocol (TIP) aims to facilitate e-commerce by enforcing atomicity guarantees in transactions distributed between several autonomous transaction processing systems. In this work, the authors explore a holiday booking scenario in which a customer is protected by the TIP; in such a way as to prevent ending up with a hotel reservation without the requested flight reservation that is enclosed in the same holiday package. TIP defines an approach that makes the commit processing independent of the communication protocol used. There are a number of potential pitfalls that make it useful to provide a formal approach to reason about the behavioral properties of TIP. The authors propose a Colored Petri Net model that allows interactive simulation and verification of correctness properties within the CPN Tools modeling environment. The model can be used in the CPN Tools environment for model checking tasks.

  4. A Petri Net model for distributed energy system

    Science.gov (United States)

    Konopko, Joanna

    2015-12-01

    Electrical networks need to evolve to become more intelligent, more flexible and less costly. The smart grid is the next generation power energy, uses two-way flows of electricity and information to create a distributed automated energy delivery network. Building a comprehensive smart grid is a challenge for system protection, optimization and energy efficient. Proper modeling and analysis is needed to build an extensive distributed energy system and intelligent electricity infrastructure. In this paper, the whole model of smart grid have been proposed using Generalized Stochastic Petri Nets (GSPN). The simulation of created model is also explored. The simulation of the model has allowed the analysis of how close the behavior of the model is to the usage of the real smart grid.

  5. Detection and Modeling of Cyber Attacks with Petri Nets

    Directory of Open Access Journals (Sweden)

    Bartosz Jasiul

    2014-12-01

    Full Text Available The aim of this article is to present an approach to develop and verify a method of formal modeling of cyber threats directed at computer systems. Moreover, the goal is to prove that the method enables one to create models resembling the behavior of malware that support the detection process of selected cyber attacks and facilitate the application of countermeasures. The most common cyber threats targeting end users and terminals are caused by malicious software, called malware. The malware detection process can be performed either by matching their digital signatures or analyzing their behavioral models. As the obfuscation techniques make the malware almost undetectable, the classic signature-based anti-virus tools must be supported with behavioral analysis. The proposed approach to modeling of malware behavior is based on colored Petri nets. This article is addressed to cyber defense researchers, security architects and developers solving up-to-date problems regarding the detection and prevention of advanced persistent threats.

  6. Manufacturing Scheduling Using Colored Petri Nets and Reinforcement Learning

    Directory of Open Access Journals (Sweden)

    Maria Drakaki

    2017-02-01

    Full Text Available Agent-based intelligent manufacturing control systems are capable to efficiently respond and adapt to environmental changes. Manufacturing system adaptation and evolution can be addressed with learning mechanisms that increase the intelligence of agents. In this paper a manufacturing scheduling method is presented based on Timed Colored Petri Nets (CTPNs and reinforcement learning (RL. CTPNs model the manufacturing system and implement the scheduling. In the search for an optimal solution a scheduling agent uses RL and in particular the Q-learning algorithm. A warehouse order-picking scheduling is presented as a case study to illustrate the method. The proposed scheduling method is compared to existing methods. Simulation and state space results are used to evaluate performance and identify system properties.

  7. The symmetric square of a curve and the Petri map

    CERN Document Server

    Bruno, A

    2011-01-01

    Let $\\M_g$ be the course moduli space of complex projective nonsingular curves of genus $g$. We prove that when the Brill-Noether number $\\rho(g,1,n)$ is non-negative the Petri locus $P^1_{g,n}\\subset \\M_g$ has a divisorial component whose closure has a non-empty intersection with $\\Delta_0$. In order to prove the result we show that the scheme $G^1_n(\\Gamma)$ that parametrizes degree $n$ pencils on a curve $\\Gamma$ is isomorphic to a component of the Hilbert scheme parametrizing certain curves on the symmetric square $\\Gamma_2$ of $\\Gamma$ and we study the properties of such a family of curves.

  8. Based Aspect-oriented Petri Nets in Software Engineering

    Science.gov (United States)

    Hu, Wensong; Yang, Xingui; Zuo, Ke

    Aspect Oriented (Aspect-Oriented, referred to as AO) as a new programming technology is increasingly cause for concern. This article describes a number of experts to study the current object-oriented Petri Nets (OO PN) adding aspect-oriented thinking, combined with software design and development cycle, given the aspect-oriented OO PN in software engineering methods and steps. Shows the method of using AO PN government office system software design and development of application examples, and gives some object class, the log section and the application form. As the plane of isolation, reducing the coupling, the use of AO PN ways in different applications will use a combination of each section, allowing code reusability enhancement. OOPN itself can process the software system design and development of effective control to ensure that the software system reliability and standardization.

  9. A method for enterprise architecture validation with colored Petri Nets

    Directory of Open Access Journals (Sweden)

    Mohammad Sadegh Alishahi

    2012-10-01

    Full Text Available Architecture includes so many documents where each describes one part of an enterprise. The problem in using such descriptions is on how to consider and use all components. Therefore, in order to organize the descriptions of enterprise architecture, we should use a framework. C4ISR is one of the enterprise architectural frameworks, which includes three views, contains some products. In order to show the products, this framework needs a unified notation, which covers all the products with various views. Unified Modeling Language (UML prepares such situation. But in order to decrease the expenses of enterprise architectural productions process, the architectural products shall be evaluated before the architectural implementation level happens. In this article, a simple way for validation of enterprise architectural products with Colored Petri Nets is presented to evaluate true behavior of architectural products well.

  10. Petri nets for steady state analysis of metabolic systems.

    Science.gov (United States)

    Voss, Klaus; Heiner, Monika; Koch, Ina

    2011-01-01

    Computer assisted analysis and simulation of biochemical pathways can improve the understanding of the structure and the dynamics of cell processes considerably. The construction and quantitative analysis of kinetic models is often impeded by the lack of reliable data. However, as the topological structure of biochemical systems can be regarded to remain constant in time, a qualitative analysis of a pathway model was shown to be quite promising as it can render a lot of useful knowledge, e. g., about its structural invariants. The topic of this paper are pathways whose substances have reached a dynamic concentration equilibrium (steady state). It is argued that appreciated tools from biochemistry and also low-level Petri nets can yield only part of the desired results, whereas executable high-level net models lead to a number of valuable additional insights by combining symbolic analysis and simulation.

  11. Steady state analysis of metabolic pathways using Petri nets.

    Science.gov (United States)

    Voss, Klaus; Heiner, Monika; Koch, Ina

    2003-01-01

    Computer assisted analysis and simulation of biochemical pathways can improve the understanding of the structure and the dynamics of cell processes considerably. The construction and quantitative analysis of kinetic models is often impeded by the lack of reliable data. However, as the topological structure of biochemical systems can be regarded to remain constant in time, a qualitative analysis of a pathway model was shown to be quite promising as it can render a lot of useful knowledge, e. g., about its structural invariants. The topic of this paper are pathways whose substances have reached a dynamic concentration equilibrium (steady state). It is argued that appreciated tools from biochemistry and also low-level Petri nets can yield only part of the desired results, whereas executable high-level net models lead to a number of valuable additional insights by combining symbolic analysis and simulation.

  12. Schedulability Analysis Method of Timing Constraint Petri Nets

    Institute of Scientific and Technical Information of China (English)

    李慧芳; 范玉顺

    2002-01-01

    Timing constraint Petri nets (TCPNs) can be used to model a real-time system specification and to verify the timing behavior of the system. This paper describes the limitations of the reachability analysis method in analyzing complex systems for existing TCPNs. Based on further research on the schedulability analysis method with various topology structures, a more general state reachability analysis method is proposed. To meet various requirements of timely response for actual systems, this paper puts forward a heuristic method for selecting decision-spans of transitions and develops a heuristic algorithm for schedulability analysis of TCPNs. Examples are given showing the practicality of the method in the schedulability analysis for real-time systems with various structures.

  13. Stochastic Petri net analysis of a replicated file system

    Science.gov (United States)

    Bechta Dugan, Joanne; Ciardo, Gianfranco

    1989-01-01

    A stochastic Petri-net model of a replicated file system is presented for a distributed environment where replicated files reside on different hosts and a voting algorithm is used to maintain consistency. Witnesses, which simply record the status of the file but contain no data, can be used in addition to or in place of files to reduce overhead. A model sufficiently detailed to include file status (current or out-of-date), as well as failure and repair of hosts where copies or witnesses reside, is presented. The number of copies and witnesses is a parameter of the model. Two different majority protocols are examined, one where a majority of all copies and witnesses is necessary to form a quorum, and the other where only a majority of the copies and witnesses on operational hosts is needed. The latter, known as adaptive voting, is shown to increase file availability in most cases.

  14. Petri Net-based Analysis of the Safety Communication Protocol

    Directory of Open Access Journals (Sweden)

    Liu Hongjie

    2013-10-01

    Full Text Available There is a few research in area of safety-critical system, therefore the study of performance analyzing method of the protocol has important practical significance for transportation engineering. This paper first briefly introduces the execution procedure of safety communication protocol, then explores the application of Petri net to establish the model of the protocol, including the process of state transition and corresponding timer which record the time, then obtains related performance data such as maintainability and failure probability, which users usually pay most attention to, with different probability of time delay and no fault in channel by simulation. Finally this paper finds that how the probability of time delay and no fault in channel could influent the maintainability and failure probability through data process with theory of probability and mathematical statistic, this could provide a certain reference for development of safety communication protocol.    

  15. Dish Stirling system integration and test progress report

    Science.gov (United States)

    Haglund, R. A.

    1982-01-01

    The integration and check-out of a complete Dish Solar Stirling Thermal Power System is described. The preliminary results of the tests conducted thus far are presented. The results are very encouraging and show promise of high performance and efficiency. The outstanding performance and durability of the 4-95 Stirling engine was the highlight of this 6 month integration and test activity. Exposure to severe heat, dust, sand and wind during the summer months and heavy rains, high winds, including sand storms and freezing cold in recent months did affected the engine or the receiver in any noticable manner.

  16. Spondyloarthritis, diffuse idiopathic skeletal hyperostosis (DISH) and chondrocalcinosis.

    Science.gov (United States)

    Armas, Jácome Brugues; Couto, Ana Rita; Bettencourt, Bruno Filipe

    2009-01-01

    The authors describe the main clinical and radiological findings of common enthesopathic disorders-spondylarthritis (SpA), chondrocalcinosis/calcium pyrophosphate dehydrate crystal deposition disease (CPPD CDD) and diffuse idiopathic skeletal hyperostosis (DISH), stressing similarities and differences which may help in the differential diagnosis. They emphasize the clinical presentation of the "pseudoankylosing spondylitis" forms of CPPD CDD. They also review the most relevant genes and molecular mechanisms associated with these conditions and with another enthesopathic disorder with high prevalence in the Japanese population-ossification of the posterior longitudinal ligament (OPLL).

  17. An analysis on Translation Strategies of Chinese Dishes

    Institute of Scientific and Technical Information of China (English)

    高慧妍

    2013-01-01

    Cuisine culture occupies a pivotal position in nation’s culture especially in China. Chinese cooking has become a link between Chinese people and people from other countries and an important window for them to know Chinese culture. Hence, to translate those Chinese dish names has been put outstandingly to us, not only because this is the need to promote the comity and understanding between them and us, but also the key job to spread our tradition culture to the world. This thesis attempts to have a brief study of Chinese cuisine naming and put forward some translation methods, such as transliteration, domestication, and so on. Without neglecting some related obstacles.

  18. Plasticity theory

    CERN Document Server

    Lubliner, Jacob

    2008-01-01

    The aim of Plasticity Theory is to provide a comprehensive introduction to the contemporary state of knowledge in basic plasticity theory and to its applications. It treats several areas not commonly found between the covers of a single book: the physics of plasticity, constitutive theory, dynamic plasticity, large-deformation plasticity, and numerical methods, in addition to a representative survey of problems treated by classical methods, such as elastic-plastic problems, plane plastic flow, and limit analysis; the problem discussed come from areas of interest to mechanical, structural, and

  19. Reliability modelling of repairable systems using Petri nets and fuzzy Lambda-Tau methodology

    Energy Technology Data Exchange (ETDEWEB)

    Knezevic, J.; Odoom, E.R

    2001-07-01

    A methodology is developed which uses Petri nets instead of the fault tree methodology and solves for reliability indices utilising fuzzy Lambda-Tau method. Fuzzy set theory is used for representing the failure rate and repair time instead of the classical (crisp) set theory because fuzzy numbers allow expert opinions, linguistic variables, operating conditions, uncertainty and imprecision in reliability information to be incorporated into the system model. Petri nets are used because unlike the fault tree methodology, the use of Petri nets allows efficient simultaneous generation of minimal cut and path sets.

  20. Fourth Workshop and Tutorial on Practical Use of Coloured Petri Nets and the CPN Tools

    DEFF Research Database (Denmark)

    Coloured Petri Nets and the CPN tools are now used by more than 750 organisations in 50 different countries all over the world (including 150 commercial companies). The purpose of this event is to bring together some of the users and in this way provide a forum for those who are interested...... in the practical use of Coloured Petri Nets and the CPN tools. This booklet contains the proceedings of the Fourth Workshop on Practical Use of Coloured Petri Nets and the CPN Tools, August 28-30, 2002. The workshop is organised by the CPN group at the Department of Computer Science, University of Aarhus, Denmark....

  1. Hierarchical Colored Timed Petri Nets for Maintenance Process Modeling of Civil Aircraft

    Institute of Scientific and Technical Information of China (English)

    FU Cheng-cheng; SUN You-chao; LU Zhong

    2008-01-01

    Civil aircraft maintenance process simulation model is an effective method for analyzing the maintainability of a civil aircraft. First, we present the Hierarchical Colored Timed Petri Nets for maintenance process modeling of civil aircraft. Then, we expound a general method of civil aircraft maintenance activities, determine the maintenance level for decomposition, and propose the methods of describing logic of relations between the maintenance activities based on Petri Net. Finally, a time Colored Petri multi-level network modeling and simulation procedures and steps are given with the maintenance example of the landing gear burst tire of a certain type of aircraft. The feasibility of the method is proved by the example.

  2. Modelling and simulation of signal transductions in an apoptosis pathway by using timed Petri nets

    Indian Academy of Sciences (India)

    Chen Li; Qi-Wei Ge; Mitsuru Nakata; Hiroshi Matsuno; Satoru Miyano

    2007-01-01

    This paper first presents basic Petri net components representing molecular interactions and mechanisms of signalling pathways, and introduces a method to construct a Petri net model of a signalling pathway with these components. Then a simulation method of determining the delay time of transitions, by using timed Petri nets – i.e. the time taken in firing of each transition – is proposed based on some simple principles that the number of tokens flowed into a place is equivalent to the number of tokens flowed out. Finally, the availability of proposed method is confirmed by observing signalling transductions in biological pathways through simulation experiments of the apoptosis signalling pathways as an example.

  3. CyberPetri at CDX 2016: Real-time Network Situation Awareness

    Energy Technology Data Exchange (ETDEWEB)

    Arendt, Dustin L.; Best, Daniel M.; Burtner, Edwin R.; Paul, Celeste

    2016-10-24

    CyberPetri is a novel visualization technique that provides a flexible map of the network based on available characteristics, such as IP address, operating system, or service. Previous work introduced CyberPetri as a visualization feature in Ocelot, a network defense tool that helped security analysts understand and respond to an active defense scenario. In this paper we present a case study in which we use the CyberPetri visualization technique to support real-time situation awareness during the 2016 Cyber Defense Exercise.

  4. Diffuse idiopathic skeletal hyperostosis (D.I.S.H.

    Directory of Open Access Journals (Sweden)

    F. De Leonardis

    2011-09-01

    Full Text Available Diffuse idiopathic skeletal hyperostosis (D.I.S.H. is a common disorder of unknown aetiology characterized by exuberant hyperostosis of the antero-lateral aspect of the spinal column, that sometimes leads to bone ankilosis, and by ossification of extra-spinal entheses. This condition is often associated with the metabolic derangement of type 2 diabetes. Primary hypertension, its cardiovascular aftereffects and lithiasis are also often present in these patients. D.I.S.H. has to be distinguished from osteoarthritis, althought they often coexist in the same patient. The mean difference lies in the anatomical target of the pathological process, that is represented by articular cartilage in osteoarthritis and by entheses in diffuse idiopathic skeletal hyperostosis. The enthesopathy leads to the ossification of the anterior longitudinal ligament of the spine and causes the formation of flowing osteophytes, while intervertebral disc space is quite preserved in early phases of the disease. Symptoms of spine involvement are not typical of the disease and consist of pain and stiffness, usually worsened by inaction and damp. It has also been described the ossification of posterior longitudinal ligament which can lead to medullary canal stenosis. Appendicular skeleton is symmetrically involved in early phases of the disease, the most distinctive affected sites being feet, olecranus and patella. Hip involvement is also frequent and may lead to severe disability and represents an important cause of invalidity. The purpose of the present review is to remark on aetiopathogenetic and clinical aspects of diffuse idiopathic skeletal hyperostosis.

  5. AZ-TH, 80 KWE Solar Dish-Stirling Facility

    Energy Technology Data Exchange (ETDEWEB)

    Osuna, R.; Enrile, J.; Sanchez, M.; Fernandez-Quero, V.; Barragan, J.; Ruiz, V.; Silva, M.; Bas, F.; Lopez-Lara, G.; Fernandez-Liebre, F.

    2006-07-01

    Ing. Jose Barragan, Solucar R and D, Avda. Buhaira 2, E-41018 Sevilla, Spain, Tel: +34 95 4937111; Fax: +34 95 4937008; jose.barragan@solucarrd.abengoa.com Abstract. An initiative to promote a 80kWe dish-stirling facility is being carried out by Solucar, an Abengoa company working on solar energy, with the support of the Renewable Energies Program of Andalusia Government TROUGH the Agencia de Innovacion (IDEA), and the Agencia Andaluza de la Energia (AAE). The plant consists of 7 stirling dishes of 11,2kWe unitary power, that will generate 104MWh of electricity in a year, and will sell it to the grid in a commercial basis under the frame of solar thermal renewable energy production regulations in Spain, that consider up to 0,18/kWh over pool market price for electricity. To achieve the feasibility of the project, a new concentrator based on single spherical 0,5 m2 curved mirrors has been proposed. It has been developed following the schemes of the traditional pedestal/arms heliostats. Foreseen cost for concentrator reaches 450/m2 when completely installed and in operation. The facility will be installed in the area of PS10 and Sevilla PV plants, in the solar park that Abengoa is promoting in Sanlucar la Mayor, in order to share maintenance, supervision, vigilance and operation costs with other bigger plants. (Author)

  6. Combined Heat & Power Using the Infinia Concentrated Solar CHP PowerDish System

    Science.gov (United States)

    2013-08-01

    FINAL REPORT Combined Heat & Power Using the Infinia Concentrated Solar CHP PowerDish System ESTCP Project EW-201145 AUGUST 2013...Combined Heat & Power Using the Infinia Concentrated Solar CHP PowerDish System 5a. CONTRACT NUMBER 5b. GRANT NUMBER 5c. PROGRAM ELEMENT NUMBER 6...demonstrated the capabilities of the Infinia PowerDish? CHP technology to generate clean solar thermal and electric energy compatible with domestic and

  7. The Nonlinear Instability Modes of Dished Shallow Shells under Circular Line Loads

    OpenAIRE

    Liu Chang-Jiang; Zheng Zhou-Lian; Huang Cong-Bing; He Xiao-Ting; Sun Jun-Yi; Chen Shan-Lin

    2011-01-01

    This paper investigated the nonlinear stability problem of dished shallow shells under circular line loads. We derived the dimensionless governing differential equations of dished shallow shell under circular line loads according to the nonlinear theory of plates and shells and solved the governing differential equations by combing the free-parameter perturbation method (FPPM) with spline function method (SFM) to analyze the nonlinear instability modes of dished shallow shell under circular l...

  8. Konzeption und Entwurf einer auf Petri-Netzen basierenden programmierbaren Kontrollschaltung

    Directory of Open Access Journals (Sweden)

    H. Baur

    2003-01-01

    Full Text Available Petri-Netze eignen sich aufgrund der direkten Darstellbarkeit von Nebenläufigkeiten und leistungsfähiger Analyseverfahren zur Beschreibung von komplexen Kontrollabläufen. Die hier vorgestellte PNDU (Petri Net Decision Unit ist ein programmierbarer Hardware- Interpreter für Kontrollalgorithmen, die durch Petri-Netze beschrieben werden. Die Petri-Netze werden kodiert in einem Speicher abgelegt und unter Einbeziehung der Eingangssignale und interner Zustände nach einem festgelegten Algorithmus abgearbeitet. Der implizite Wartezustand der PNDU motiviert in Hinblick auf den Einsatz in eingebetteten, batteriebetriebenen Geräten eine asynchrone Realisierung. Die PNDU wurde mit VHDL als synchrone und vergleichend dazu als selbstgetaktete Schaltung entworfen.

  9. An application of timed Petri nets to S/C operations analysis: The Aristoteles autonomy concept

    Science.gov (United States)

    Barro, E.; Rossi, F.

    1990-10-01

    Petri nets as a methodology for the study and analysis of systems behavior are discussed. They can be tailored to timed approaches, to highlight all the system possible timing critical and deadlock conditions. As a consequence, it is valuable to apply a Petri nets-based methodology in the space environment. Spacecraft operations analysis during system definition is one area of possible application. The application of Petri nets, as a basis for an investigation methodology in the Aristoteles spacecraft autonomy concept definition is described. Significant results are obtained allowing the production of a consistent, formally clean and self explaining system description, to be used as an aid to design and a tool for system evaluation. Such positive achievements support the exploitation of Petri nets-based methodologies in spacecraft operations to describe and analyze the overall space system behavior.

  10. Petri Net Based Metabolic Network Parameters Fitting with GPU Acceleration%Petri Net Based Metabolic Network Parameters Fitting with GPU Acceleration

    Institute of Scientific and Technical Information of China (English)

    Gao, Jun; Zhu, Ruixin; Liu, Qi; Cao, Zhiwei

    2011-01-01

    Classical Petri net has been applied into biological analysis, especially as a qualitative model for biochemical pathways analysis, but lack of the ability for quantitative kinetic simulations. In our study, we presented an integra- tion work of the qualitative model--Petri nets with the quantitative approach-ordinary differential equations (ODEs) for the modeling and analysis of metabolic networks. As an application of our study, the computational modeling of arachidonic acid (AA) biochemical network was provided. A Petri net was set up to present the constraint-based dynamic simulations on AA metabolic network combined with the validated ODEs model. Furthermore, Graphics Processing Unit (GPU) was adopted to accelerate the calculation of kinetic parameters unavailable from experi- ments. Our results have indicated that the proposed simulation method was practicable and useful with GPU accel- eration, and provides new clues for the large-scale qualitative and quantitative models of biochemical networks.

  11. Activity and accomplishments of dish/Stirling electric power system development

    Science.gov (United States)

    Livingston, F. R.

    1985-01-01

    The development of the solar parabolic-dish/Stirling-engine electricity generating plant known as the dish/Stirling electric power system is described. The dish/Stirling electric power system converts sunlight to electricity more efficiently than any known existing solar electric power system. The fabrication and characterization of the test bed concentrators that were used for Stirling module testing and of the development of parabolic dish concentrator No. 2, an advanced solar concentrator unit considered for use with the Stirling power conversion unit is discussed.

  12. Regional food dishes in the Brazilian National School Food Program: Acceptability and nutritional composition

    Directory of Open Access Journals (Sweden)

    Diogo thimoteo da Cunha

    2014-08-01

    Full Text Available Objective: the objective of this study was to evaluate the nutritional composition and describe the acceptability of regional culinary dishes served to students from public schools of rural and urban areas. Methods: Ten Brazilian regional dishes were evaluated for acceptability and nutritional composition. the survey was conducted in schools located in rural and urban areas of two cities in the state of São Paulo. Dish acceptability was evaluated using leftover analysis and a 5-point facial hedonic scale. the adherence index was calculated and used as an indirect measure of acceptance, and the nutritional composition was calculated based on the technical files of each dish. Results: A total of 2,384 students from 20 schools participated in the study and 1,174 tasted and evaluated the dishes. the test using the 5-point facial hedonic scale demonstrated that five dishes (Caldo verde soup, persimmon jelly, chicken with okra, puréed cornmeal with spinach, and arugula pizza had an acceptability rate above 85.0%. the mean adherence indices were 57.3% and 55.6% in urban and rural environments, respectively. Analysis of the nutritional composition of regional dishes indicates that these dishes can partially meet macronutrient recommendations. Conclusion: the tested dishes can become part of school menus as they were accepted or partly accepted by the students regardless of school location, whether rural or urban. the cultural heritage is an important resource for the food sovereignty of a country and should be constantly encouraged.

  13. Workshop on Practical Use of Coloured Petri Nets and Design/CPN

    DEFF Research Database (Denmark)

    This booklet contains the proceedings of the 1998 Workshop on Practical use of Coloured Petri Nets and Design/CPN. The papers are also available in electronic form via the CPN Web pages at University of Aarhus.......This booklet contains the proceedings of the 1998 Workshop on Practical use of Coloured Petri Nets and Design/CPN. The papers are also available in electronic form via the CPN Web pages at University of Aarhus....

  14. Automation of Presentation Record Production Based on Rich-Media Technology Using SNT Petri Nets Theory.

    Science.gov (United States)

    Martiník, Ivo

    2015-01-01

    Rich-media describes a broad range of digital interactive media that is increasingly used in the Internet and also in the support of education. Last year, a special pilot audiovisual lecture room was built as a part of the MERLINGO (MEdia-rich Repository of LearnING Objects) project solution. It contains all the elements of the modern lecture room determined for the implementation of presentation recordings based on the rich-media technologies and their publication online or on-demand featuring the access of all its elements in the automated mode including automatic editing. Property-preserving Petri net process algebras (PPPA) were designed for the specification and verification of the Petri net processes. PPPA does not need to verify the composition of the Petri net processes because all their algebraic operators preserve the specified set of the properties. These original PPPA are significantly generalized for the newly introduced class of the SNT Petri process and agent nets in this paper. The PLACE-SUBST and ASYNC-PROC algebraic operators are defined for this class of Petri nets and their chosen properties are proved. The SNT Petri process and agent nets theory were significantly applied at the design, verification, and implementation of the programming system ensuring the pilot audiovisual lecture room functionality.

  15. Automation of Presentation Record Production Based on Rich-Media Technology Using SNT Petri Nets Theory

    Directory of Open Access Journals (Sweden)

    Ivo Martiník

    2015-01-01

    Full Text Available Rich-media describes a broad range of digital interactive media that is increasingly used in the Internet and also in the support of education. Last year, a special pilot audiovisual lecture room was built as a part of the MERLINGO (MEdia-rich Repository of LearnING Objects project solution. It contains all the elements of the modern lecture room determined for the implementation of presentation recordings based on the rich-media technologies and their publication online or on-demand featuring the access of all its elements in the automated mode including automatic editing. Property-preserving Petri net process algebras (PPPA were designed for the specification and verification of the Petri net processes. PPPA does not need to verify the composition of the Petri net processes because all their algebraic operators preserve the specified set of the properties. These original PPPA are significantly generalized for the newly introduced class of the SNT Petri process and agent nets in this paper. The PLACE-SUBST and ASYNC-PROC algebraic operators are defined for this class of Petri nets and their chosen properties are proved. The SNT Petri process and agent nets theory were significantly applied at the design, verification, and implementation of the programming system ensuring the pilot audiovisual lecture room functionality.

  16. Automation of Presentation Record Production Based on Rich-Media Technology Using SNT Petri Nets Theory

    Science.gov (United States)

    Martiník, Ivo

    2015-01-01

    Rich-media describes a broad range of digital interactive media that is increasingly used in the Internet and also in the support of education. Last year, a special pilot audiovisual lecture room was built as a part of the MERLINGO (MEdia-rich Repository of LearnING Objects) project solution. It contains all the elements of the modern lecture room determined for the implementation of presentation recordings based on the rich-media technologies and their publication online or on-demand featuring the access of all its elements in the automated mode including automatic editing. Property-preserving Petri net process algebras (PPPA) were designed for the specification and verification of the Petri net processes. PPPA does not need to verify the composition of the Petri net processes because all their algebraic operators preserve the specified set of the properties. These original PPPA are significantly generalized for the newly introduced class of the SNT Petri process and agent nets in this paper. The PLACE-SUBST and ASYNC-PROC algebraic operators are defined for this class of Petri nets and their chosen properties are proved. The SNT Petri process and agent nets theory were significantly applied at the design, verification, and implementation of the programming system ensuring the pilot audiovisual lecture room functionality. PMID:26258164

  17. Plastic Jellyfish.

    Science.gov (United States)

    Moseley, Christine

    2000-01-01

    Presents an environmental science activity designed to enhance students' awareness of the hazards of plastic waste for wildlife in aquatic environments. Discusses how students can take steps to reduce the effects of plastic waste. (WRM)

  18. Status of the Boeing Dish Engine Critical Component Project

    Energy Technology Data Exchange (ETDEWEB)

    Brau, H.W.; Diver, R.B.; Nelving, H.; Stone, K.W.

    1999-01-08

    The Boeing Company's Dish Engine Critical Component (DECC) project started in April of 1998. It is a continuation of a solar energy program started by McDonnell Douglas (now Boeing) and United Stirling of Sweden in the mid 1980s. The overall objectives, schedule, and status of this project are presented in this paper. The hardware test configuration, hardware background, operation, and test plans are also discussed. A summary is given of the test data, which includes the daily power performance, generated energy, working-gas usage, mirror reflectivity, solar insolation, on-sun track time, generating time, and system availability. The system performance based upon the present test data is compared to test data from the 1984/88 McDonnell Douglas/United Stirling AB/Southem California Edison test program. The test data shows that the present power, energy, and mirror performance is comparable to when the hardware was first manufactured 14 years ago.

  19. Commercialization of dish-Stirling solar terrestrial systems

    Science.gov (United States)

    Ross, Brad; Penswick, Barry; White, Maury; Cooper, Martin; Farbman, Gerald

    1990-01-01

    The requirements for dish-Stirling commercialization are described. The requirements for practical terrestrial power systems, both technical and economic, are described. Solar energy availability, with seasonal and regional variations, is discussed. The advantages and disadvantages of hybrid operation are listed. The two systems described use either a 25-kW free-piston Stirling hydraulic engine or a 5-kW kinematic Stirling engine. Both engines feature long-life characteristics that result from the use of welded metal bellows as hermetic seals between the working gas and the crankcase fluid. The advantages of the systems, the state of the technology, and the challenges that remain are discussed. Technology transfer between solar terrestrial Stirling applications and other Stirling applications is predicted to be important and synergistic.

  20. Dishing up the Data: A Decade of Space Missions

    CERN Document Server

    Sarkissian, John

    2012-01-01

    The past decade has seen Parkes once again involved in a wide range of space tracking activities that have added to its illustrious legacy. This contribution is a personal recollection of those tracking efforts - both real and celluloid. We begin in a light-hearted vein with some behind-the-scenes views of the popular film, "The DISH", and then turn to more serious contributions; discussing the vital role of the telescope in alleviating the great "traffic jam" at Mars in 2003/04 and salvaging the Doppler Wind Experiment as the Huygens probe descended though the atmosphere of Saturn's largest moon, Titan, in mid-decade. We cap off the decade with a discussion of the search for the missing Apollo 11 slow-scan TV tapes.

  1. Analysis Groove Characteristics of Friction Dishes in Wet Speeding Clutch

    Institute of Scientific and Technical Information of China (English)

    HongYue; LiuJin; JinShiliang

    2004-01-01

    The impacts of different groove shapes, numbers, and angle of friction dish on transmitting torque, speed, push pressure in wet speeding clutch are discussed in this paper. Since the wet speeed governing clutch works within hydrodynamic lubrication mixture lubrication. boundary, lubrication and contact situation, the oils combining with a-hydrocarbon or polyester are getting widely used as lubricant.The power-law fluid model with Patir-Cheng average flow model, GT asperity contact model and oil film inertia are applied for average Reynolds equation setting, In order to investigate the relationship between average push pressure within hydrodynamic lubrication and mixture lubrication, average transmitting torque and output speed, the numeral calculation and analysis are presented. According to calculation, it is found that the groove shape, groove angle and groove numbers affect the average transfer torque and push pressure with the speed rate.

  2. Simulations for single-dish intensity mapping experiments

    CERN Document Server

    Bigot-Sazy, M -A; Battye, R A; Browne, I W A; Ma, Y -Z; Maffei, B; Noviello, F; Remazeilles, M; Wilkinson, P N

    2015-01-01

    HI intensity mapping is an emerging tool to probe dark energy. Observations of the redshifted HI signal will be contaminated by instrumental noise, atmospheric and Galactic foregrounds. The latter is expected to be four orders of magnitude brighter than the HI emission we wish to detect. We present a simulation of single-dish observations including an instrumental noise model with 1/f and white noise, and sky emission with a diffuse Galactic foreground and HI emission. We consider two foreground cleaning methods: spectral parametric fitting and principal component analysis. For a smooth frequency spectrum of the foreground and instrumental effects, we find that the parametric fitting method provides residuals that are still contaminated by foreground and 1/f noise, but the principal component analysis can remove this contamination down to the thermal noise level. This method is robust for a range of different models of foreground and noise, and so constitutes a promising way to recover the HI signal from the ...

  3. Commercialization of dish-Stirling solar terrestrial systems

    Science.gov (United States)

    Ross, Brad; Penswick, Barry; White, Maury; Cooper, Martin; Farbman, Gerald

    1990-01-01

    The requirements for dish-Stirling commercialization are described. The requirements for practical terrestrial power systems, both technical and economic, are described. Solar energy availability, with seasonal and regional variations, is discussed. The advantages and disadvantages of hybrid operation are listed. The two systems described use either a 25-kW free-piston Stirling hydraulic engine or a 5-kW kinematic Stirling engine. Both engines feature long-life characteristics that result from the use of welded metal bellows as hermetic seals between the working gas and the crankcase fluid. The advantages of the systems, the state of the technology, and the challenges that remain are discussed. Technology transfer between solar terrestrial Stirling applications and other Stirling applications is predicted to be important and synergistic.

  4. Secondary concentrators for parabolic dish solar thermal power systems

    Science.gov (United States)

    Jaffe, L. D.; Poon, P. T.

    1981-01-01

    A variety of different concepts are currently being studied with the objective to lower the cost of parabolic mirrors and to provide alternatives. One of the considered approaches involves the use of compound concentrators. A compound solar concentrator is a concentrator in which the sunlight is reflected or refracted more than once. It consists of a primary mirror or lens, whose aperture determines the amount of sunlight gathered, and a smaller secondary mirror or lens. Additional small optical elements may also be incorporated. The possibilities and problems regarding a use of compound concentrators in parabolic dish systems are discussed. Attention is given to concentrating secondary lenses, secondary imaging and concentrating mirrors, conical secondary mirrors, compound elliptic secondary concentrating mirrors, and hyperbolic trumpet secondary concentrating mirrors.

  5. Thermal Model of a Dish Stirling Cavity-Receiver

    Directory of Open Access Journals (Sweden)

    Rubén Gil

    2015-01-01

    Full Text Available This paper presents a thermal model for a dish Stirling cavity based on the finite differences method. This model is a theoretical tool to optimize the cavity in terms of thermal efficiency. One of the main outcomes of this work is the evaluation of radiative exchange using the radiosity method; for that purpose, the view factors of all surfaces involved have been accurately calculated. Moreover, this model enables the variation of the cavity and receiver dimensions and the materials to determine the optimal cavity design. The tool has been used to study the cavity optimization regarding geometry parameters and material properties. Receiver absorptivity has been identified as the most influential property of the materials. The optimal aperture height depends on the minimum focal space.

  6. Evaluation of software architecture using fuzzy colored Petri nets

    Directory of Open Access Journals (Sweden)

    Vahid Abroshan

    2013-02-01

    Full Text Available Software Architecture (SA is one of the most important artifacts for life cycle of a software system because it incorporates some important decisions and principles for the system development. On the other hand, developing the systems based on uncertain and ambiguous requirement has been increased, significantly. Therefore, there have been significant attentions on SA requirements. In this paper, we present a new method for evaluation of performance characteristics based on a use case, response time, and queue length of SA. Since there are some ambiguities associated with considered systems, we use the idea of Fuzzy UML (F-UML diagrams. In addition, these diagrams have been enriched with performance annotations using proposed Fuzzy-SPT sub profile, the extended version of SPT profile proposed by OMG. Then, these diagrams are mapped into an executable model based on Fuzzy Colored Petri Nets (FCPN and finally the performance metrics are calculated using the proposed algorithms. We have implemented CPN-Tools for creating and evaluating the FCPN model.

  7. SOFTWARE FOR FAULT DIAGNOSIS USING KNOWLEDGE MODELS IN PETRI NETS

    Directory of Open Access Journals (Sweden)

    ADRIAN ARBOLEDA

    2012-01-01

    Full Text Available Los sistemas de diagnóstico de fallas en empresas asociadas al sector eléctrico requieren propiedades de precisión y flexibilidad cuando surgen eventos de falla. Actualmente existen sistemas que pretenden mejorar el proceso de diagnóstico mediante varios métodos y técnicas computacionales, reduciendo el tiempo de respuesta a perturbaciones. Sin embargo, son pocas las propuestas que unifican modelos gráficos de conocimiento con las señales de un proceso que pueden ofrecer dispositivos como controladores lógicos programables (PLCs. Este artículo propone un software novedoso guiado por modelos basados en redes de Petri e integrado con señales del proceso, para el diagnóstico de falla en centrales de generación eléctrica. Un caso de estudio demuestra la flexibilidad y adaptabilidad del software cuando nuevas nociones en los modelos de conocimiento cambian, sin realizar procedimientos de reingeniería al software.

  8. Dependency of dishing on polish time and slurry chemistry in Cu CMP

    NARCIS (Netherlands)

    Nguyen Hoang, V.; van Kranenburg, H.; Woerlee, P.H.

    2000-01-01

    In this paper the influences of slurry chemistry and thickness of the copper layer on dishing will be discussed. The dishing is studied for different patterns and variable polishing times. We found that the concentration of the oxidiser and the thickness of copper layer have a strong impact on

  9. On Approaches to C-E Translation of Chinese Dish Names

    Institute of Scientific and Technical Information of China (English)

    ZHANG Zi-shun

    2015-01-01

    Literal translation and free translation are the most common methods of translation. It may be accepted that either the two methods or one, or neither on account of the different understandings of the two methods. The author tries to probe into some approaches to C-E translation of Chinese dish names according to the contrastive studies between Chinese and English dish names.

  10. Dish Stirling High Performance Thermal Storage FY14Q3 Quad Chart.

    Energy Technology Data Exchange (ETDEWEB)

    Andraka, Charles E. [Sandia National Laboratories (SNL-NM), Albuquerque, NM (United States)

    2014-07-01

    The project goals are: demonstrate the feasibility of significant thermal storage for dish Stirling systems to leverage their existing high performance to greater capacity; demonstrate key components of a latent storage and transport system enabling on-dish storage with low exergy losses; an provide technology path to a 25kWe system with 6 hours of storage.

  11. Dependency of dishing on polish time and slurry chemistry in Cu CMP

    NARCIS (Netherlands)

    Nguyen, V.; Kranenburg, van H.; Woerlee, P.

    2000-01-01

    In this paper the influences of slurry chemistry and thickness of the copper layer on dishing will be discussed. The dishing is studied for different patterns and variable polishing times. We found that the concentration of the oxidiser and the thickness of copper layer have a strong impact on dishi

  12. Grigori Petrišin: Ajalehes Kesknädal 25. märtsil 2009 ilmunud publikatsiooni ümberlükkamine / Grigori Petrišin

    Index Scriptorium Estoniae

    Petrišin, Grigori

    2009-01-01

    Riigikogu liikme, endise Tallinna abilinnapea Kalev Kallo poole pöördus ettevõtja Grigori Petrišin, keda kaitsepolitsei oli sundinud väidetavalt oma firma nimel kirjutama linnajuhte kompromiteerivaid kirju. Nüüd väidab ettevõtja, et teda on ära kasutatud valimiseelsetes võimumängudes

  13. Grigori Petrišin: Ajalehes Kesknädal 25. märtsil 2009 ilmunud publikatsiooni ümberlükkamine / Grigori Petrišin

    Index Scriptorium Estoniae

    Petrišin, Grigori

    2009-01-01

    Riigikogu liikme, endise Tallinna abilinnapea Kalev Kallo poole pöördus ettevõtja Grigori Petrišin, keda kaitsepolitsei oli sundinud väidetavalt oma firma nimel kirjutama linnajuhte kompromiteerivaid kirju. Nüüd väidab ettevõtja, et teda on ära kasutatud valimiseelsetes võimumängudes

  14. Polynomial-time algorithm for the legal firing sequences problem of a type of synchronous composition Petri nets

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    As far as we know, the testing problem of legal firing sequence is NP-complete for general Petri net, the related results of this problem on the polynomial-time solvability are limited only to some special net classes, such as persistent Petri nets, conflict-free Petri nets and state machine Petri nets. In this paper, the language properties of synchronous composition net are discussed. Based on these results, the testing algorithm polynomial-time complexity for legal firing sequence is proposed. Therefore, net classification of polynomial-time solvability for testing legal firing sequence is extended.

  15. Diffuse Idiopathic Skeletal Hyperostosis (DISH) and Impaired Physical Function: The Rancho Bernardo Study.

    Science.gov (United States)

    Katzman, Wendy B; Huang, Mei-Hua; Kritz-Silverstein, Donna; Barrett-Connor, Elizabeth; Kado, Deborah M

    2017-07-01

    Investigate associations of diffuse idiopathic skeletal hyperostosis (DISH) with self-reported and measured physical function in older adults. Cross-sectional analyses of data collected in 1992-96 from a longitudinal cohort. Research clinic within a community. Community-dwelling men (n = 630) and women (n = 961), mean age 71.5 years (SD = 10.8), from the Rancho Bernardo Study. DISH assessed from lateral thoracic and lumbar spine radiographs; self-reported difficulty bending over to the floor, walking 2-3 level blocks, or climbing 1 flight of stairs; performance-based measures of grip strength and chair-stand testing (ability to stand up and sit down in a chair 5 times without using chair arms). DISH was present in 25.6% of men and 5.5% of women. In age and sex-adjusted models, those with DISH had 1.72-fold increased odds (95% CI: 1.13, 2.62) of self-reported difficulty bending; this remained significant after further adjustment for Cobb angle, weight, stroke, arthritis, and exercise, OR = 1.69, (95% CI: 1.07, 2.66). In fully adjusted multivariate models, those with DISH had worse grip strength, -1.08 kg, P = .01, but did not differ from those without DISH on walking or climbing stairs. In sex-stratified, fully adjusted models, among men only, those with DISH were 2.17-times (95% CI: 1.04, 4.52) more likely to be unable to complete 5 chair stands without using their arms. DISH was less prevalent in women but affected almost one-quarter of older white men. People with DISH are more likely to experience physical functional impairment, suggesting that DISH has clinical correlations and is not an incidental radiographic finding. © 2017, Copyright the Authors Journal compilation © 2017, The American Geriatrics Society.

  16. Modeling Integrated Cellular Machinery Using Hybrid Petri-Boolean Networks

    Science.gov (United States)

    Berestovsky, Natalie; Zhou, Wanding; Nagrath, Deepak; Nakhleh, Luay

    2013-01-01

    The behavior and phenotypic changes of cells are governed by a cellular circuitry that represents a set of biochemical reactions. Based on biological functions, this circuitry is divided into three types of networks, each encoding for a major biological process: signal transduction, transcription regulation, and metabolism. This division has generally enabled taming computational complexity dealing with the entire system, allowed for using modeling techniques that are specific to each of the components, and achieved separation of the different time scales at which reactions in each of the three networks occur. Nonetheless, with this division comes loss of information and power needed to elucidate certain cellular phenomena. Within the cell, these three types of networks work in tandem, and each produces signals and/or substances that are used by the others to process information and operate normally. Therefore, computational techniques for modeling integrated cellular machinery are needed. In this work, we propose an integrated hybrid model (IHM) that combines Petri nets and Boolean networks to model integrated cellular networks. Coupled with a stochastic simulation mechanism, the model simulates the dynamics of the integrated network, and can be perturbed to generate testable hypotheses. Our model is qualitative and is mostly built upon knowledge from the literature and requires fine-tuning of very few parameters. We validated our model on two systems: the transcriptional regulation of glucose metabolism in human cells, and cellular osmoregulation in S. cerevisiae. The model produced results that are in very good agreement with experimental data, and produces valid hypotheses. The abstract nature of our model and the ease of its construction makes it a very good candidate for modeling integrated networks from qualitative data. The results it produces can guide the practitioner to zoom into components and interconnections and investigate them using such more

  17. Modeling integrated cellular machinery using hybrid Petri-Boolean networks.

    Directory of Open Access Journals (Sweden)

    Natalie Berestovsky

    Full Text Available The behavior and phenotypic changes of cells are governed by a cellular circuitry that represents a set of biochemical reactions. Based on biological functions, this circuitry is divided into three types of networks, each encoding for a major biological process: signal transduction, transcription regulation, and metabolism. This division has generally enabled taming computational complexity dealing with the entire system, allowed for using modeling techniques that are specific to each of the components, and achieved separation of the different time scales at which reactions in each of the three networks occur. Nonetheless, with this division comes loss of information and power needed to elucidate certain cellular phenomena. Within the cell, these three types of networks work in tandem, and each produces signals and/or substances that are used by the others to process information and operate normally. Therefore, computational techniques for modeling integrated cellular machinery are needed. In this work, we propose an integrated hybrid model (IHM that combines Petri nets and Boolean networks to model integrated cellular networks. Coupled with a stochastic simulation mechanism, the model simulates the dynamics of the integrated network, and can be perturbed to generate testable hypotheses. Our model is qualitative and is mostly built upon knowledge from the literature and requires fine-tuning of very few parameters. We validated our model on two systems: the transcriptional regulation of glucose metabolism in human cells, and cellular osmoregulation in S. cerevisiae. The model produced results that are in very good agreement with experimental data, and produces valid hypotheses. The abstract nature of our model and the ease of its construction makes it a very good candidate for modeling integrated networks from qualitative data. The results it produces can guide the practitioner to zoom into components and interconnections and investigate them

  18. Modeling integrated cellular machinery using hybrid Petri-Boolean networks.

    Directory of Open Access Journals (Sweden)

    Natalie Berestovsky

    Full Text Available The behavior and phenotypic changes of cells are governed by a cellular circuitry that represents a set of biochemical reactions. Based on biological functions, this circuitry is divided into three types of networks, each encoding for a major biological process: signal transduction, transcription regulation, and metabolism. This division has generally enabled taming computational complexity dealing with the entire system, allowed for using modeling techniques that are specific to each of the components, and achieved separation of the different time scales at which reactions in each of the three networks occur. Nonetheless, with this division comes loss of information and power needed to elucidate certain cellular phenomena. Within the cell, these three types of networks work in tandem, and each produces signals and/or substances that are used by the others to process information and operate normally. Therefore, computational techniques for modeling integrated cellular machinery are needed. In this work, we propose an integrated hybrid model (IHM that combines Petri nets and Boolean networks to model integrated cellular networks. Coupled with a stochastic simulation mechanism, the model simulates the dynamics of the integrated network, and can be perturbed to generate testable hypotheses. Our model is qualitative and is mostly built upon knowledge from the literature and requires fine-tuning of very few parameters. We validated our model on two systems: the transcriptional regulation of glucose metabolism in human cells, and cellular osmoregulation in S. cerevisiae. The model produced results that are in very good agreement with experimental data, and produces valid hypotheses. The abstract nature of our model and the ease of its construction makes it a very good candidate for modeling integrated networks from qualitative data. The results it produces can guide the practitioner to zoom into components and interconnections and investigate them

  19. Dish-based CPV-T for rooftop generation

    Science.gov (United States)

    Davila-Peralta, Christian; Hyatt, Justin; Alfred, Dan; Struble, Morgan; Sodari, Frank; Angel, Roger

    2017-09-01

    Hybrid CPV-T with combined electrical and thermal output is well suited to solar generation from fixed limited areas, such as on the roof of an industrial or commercial facility with need for heat. This application will become especially attractive once overall electrical conversion efficiency of 40% is reached, as is projected for REhnu CPV systems using multijunction cells of 50% efficiency, anticipated in a few years. We outline here a configuration of dish- based CPV trackers optimized for close packing on a flat roof in a triangular grid, with a mirror area-to-ground area ratio of 50%. When the geometry of shadowing averaged over a year is taken into account, 80% of all the sunlight that would strike the rooftop is directed into the receivers. Such an array on a given area of flat roof will generate more electrical energy than would be possible with conventional PV panels, even if covering the entire rooftop, because of silicon's relative inefficiency. For example, in Tucson, the annual average global flux of 5.7 kWh/m2/day on a horizontal surface covered with 22% silicon modules will yield 1.25 kWh/m2/day. We show that a CPV system collecting 80% of all the direct sunlight of 7.0 kWh/m2 and converting it with 40% efficiency will yield 2.24 kWh/m2/day of rooftop area, nearly twice as much4. Thermal power will double again the total energy yield. A dual axis CPV-T tracker designed specifically very close spacing has been built to carry a single dish mirror of the standard type used in REhnu's M-8 generator, described by Stalcup et al in these proceedings1,2. Sunlight is collected and focused by a single square paraboloidal mirror, 1.65 × 1.65 m with focal length of 1.5 m. For closest possible packing without mechanical interference, and for broad distribution of load on a rooftop, the mirror and receiver are mounted to a C-ring structure, configured such that the elevation and azimuth axes intersect at a virtual pivot, at the center of the sphere that just

  20. A Petri net-based approach for supporting aspect-oriented modeling

    Institute of Scientific and Technical Information of China (English)

    Lianwei GUAN; Xingyu LI; Hao HU; Jian LU

    2008-01-01

    The concept of aspect-orientation allows for modularizing crosscutting concerns as aspect modules. Aspect-orientation originally emerged at the program-ming level, and has stretched over other development phases now. Among them aspect-oriented modeling (AOM) is a hot topic, and there are many approaches supporting it. Petri net is a good formalism which can provide the foundations for modeling software and simulating its execution, but fails to resolve the prob-lem of crosscutting concerns to support AOM. So, this paper presents an approach which extends the Petri net so as to support the AOM. In this paper, the basic functions of the system are modeled as base net by Petri net, and the crosscutting concerns are modeled as aspect nets. In order to analyze the whole system, woven mechanism is proposed to compose the aspect nets and base net together. The problems about aspect-aspect conflict and conflict relations may exist among the aspect nets matching the shared join point, thus this paper propose solutions to resolve them. The Object Petri net which is an extension of traditional Petri net is also extended so as to support aspect-oriented mod-eling here.

  1. Testing of the SAIC facets on the stretched-membrane dish

    Science.gov (United States)

    Grossman, J. W.; Erdman, W. W.; Houser, R. M.; Davenport, R.

    1994-04-01

    A dish structure sized for a 25 kW electric dish/generator system has been installed at the National Solar Thermal Test Facility (NSTTF). The dish is used as an optical test bed for prototype stretched-membrane facets. Sandia procured twelve (12) stretched-membrane facets from Science Applications International Corporation (SAIC) for installation on the dish structure. Individual facet optical performance was measured using the 2f test method under development at Sandia. Four facets were tested on-sun using the test truss at the NSTTF prior to installation on the dish structure. During the final stages of the structure assembly, the facets were installed for testing. A distant light source alignment technique was used to align the facets to a 9 meter focal length. The alignment and focus were optimized with on-sun measurements of individual facet characteristics. On-sun flux maps of the image were made using the Beam Characterization System. Calorimetry tests were performed using a cold water calorimeter. This data was used to create a power intercept curve and predict the power inside apertures of different sizes. The focal plane was moved to 9.95 meters and the alignment, optimization, and on-sun tests repeated. This paper presents the results of the testing on the individual facets as well as the results of testing the dish system. The effects of the change in focal length on the optical performance of the dish are shown in the results.

  2. Optimization of Dish Solar Collectors with and without Secondary Concentrators

    Science.gov (United States)

    Jaffe, L. D.

    1982-01-01

    Methods for optimizing parabolic dish solar collectors and the consequent effects of various optical, thermal, mechanical, and cost variables are examined. The most important performance optimization is adjusting the receiver aperture to maximize collector efficiency. Other parameters that can be adjusted to optimize efficiency include focal length, and, if a heat engine is used, the receiver temperature. The efficiency maxima associated with focal length and receiver temperature are relatively broad; it may, accordingly, be desirable to design somewhat away from the maxima. Performance optimization is sensitive to the slope and specularity errors of the concentrator. Other optical and thermal variables affecting optimization are the reflectance and blocking factor of the concentrator, the absorptance and losses of the receiver, and, if a heat engine is used, the shape of the engine efficiency versus temperature curve. Performance may sometimes be improved by use of an additional optical element (a secondary concentrator) or a receiver window if the errors of the primary concentrator are large or the receiver temperature is high.

  3. Graphic user interface testing based on Petri net%基于 Petri 网的图形用户界面测试

    Institute of Scientific and Technical Information of China (English)

    林涛; 高建华

    2016-01-01

    在不确定上下文相关的环境中,图形用户界面测试主要依靠随机测试以及测试人员的从业经验,其有效性低。提高图形用户界面测试的效率是一个未解难题。因此,通过引入离散并行系统的 Petri 网理论,定义了图形用户界面的事件、事件序列和事件分解等概念,将可达性、有界性、活性以及强连通性等 Petri 网的重要性质延伸至此领域,以提高图形用户界面测试的覆盖面和效率。并且试图解决不可达、不强连通、死锁、无界、不符合初始模型和跳转错误等六类图形用户界面缺陷问题。实验证明基于 Petri 网的图形用户界面测试在事件覆盖数、代码行覆盖数以及缺陷发现数等方面均优于其他方法。%In environment of undetermined and context-sensitive,graphic user interface testing mainly depends on random tes-ting and testers’professional experience,the effectiveness being low.It is an unresolved puzzle for graphic user interface tes-ting.Therefore,it is brought in the Petri net theory in the discrete and parallel system,defining concepts of event,events se-quence,and events decomposition in graphic user interface.The paper introduced some significant properties of Petri net,such as reachability,roundedness,liveness and strong connectedness to this field,so as to improve the coverage and efficiency of graphic user interface testing.In addition,an attempt to solve six categories bugs in graphic user interface,such as non-reach-ability,not strong connected,dead-lock,unbounded,not suitable to the original model and error jumping is conducted.The ex-periment proves that graphic user interface testing based on Petri net is more effective than other test methods in coverage of e-vents,code lines as well as the number of fault detection.

  4. Liveness Problem of Petri Nets Supervisory Control Theory for Discrete Event Systems

    Institute of Scientific and Technical Information of China (English)

    Hong-Ye SU; Wei-Min WU; Jian CHU

    2005-01-01

    A quite great progress of the supervisory control theory for discrete event systems (DES)has been made in the past nearly twenty years, and now, automata, formal language and Petri nets become the main research tools. This paper focus on the Petri nets based supervisory control theory of DES. Firstly, we review the research results in this field, and claim that there generally exists a problem in Petri nets based supervisory control theory of DES, that is, the deadlock caused by the controller introduced to enforce the given specification occurs in the closed-loop systems, especially the deadlock occurs in the closed-loop system in which the original plant is live. Finally, a possible research direction is presented for the solution of this problem.

  5. MODELING AND SIMULATION OF QUEUE WAITING THROUGH THE CONCEPT OF PETRI NETS

    Directory of Open Access Journals (Sweden)

    Emilija KAMCEVA

    2011-08-01

    Full Text Available Petri Nets-PN are a graphical formalism which is gaining popularity in recent years as a tool in Matlab for the representation of complex logical interactions among physical components or activities in a system. This notes are devoted to introduce the formalism of Petri nets with particular emphasis on the application of the methodology in the area of the performance and reliability modelling and analysis of systems. A technique is presented whereby queueing network models and generalized stochastic Petri nets are combined in such a way as to exploit the best features of both modeling techniques. The resulting hierarchical modeling approach is useful in the solution of complex models of system behavior.

  6. Reconstruction of extended Petri nets from time-series data by using logical control functions.

    Science.gov (United States)

    Durzinsky, Markus; Marwan, Wolfgang; Wagler, Annegret

    2013-01-01

    The aim of this work is to extend a previously presented algorithm (Durzinsky et al. 2008b in Computational methods in systems biology, LNCS, vol 5307. Springer, Heidelberg, pp 328–346; Marwan et al. 2008 in Math Methods Oper Res 67:117–132) for the reconstruction of standard place/transition Petri nets from time-series of experimental data sets. This previously reported method finds provably all networks capable to reproduce the experimental observations. In this paper we enhance this approach to generate extended Petri nets involving mechanisms formally corresponding to catalytic or inhibitory dependencies that mediate the involved reactions. The new algorithm delivers the set of all extended Petri nets being consistent with the time-series data used for reconstruction. It is illustrated using the phosphate regulatory network of enterobacteria as a case study.

  7. Using Petri Nets For Resource Management Modeling In The Operating Systems

    Directory of Open Access Journals (Sweden)

    Adalat Karimov

    2012-01-01

    Full Text Available Nowadays, with advances in computer science and increase in processor speed, modeling methods have found extensive applications in industrial fields. Petri Nets are one of these modeling methods. Petri Nets are based on graph theory and are applied specifically for concurrent and asynchronous applications. As executable models, they are capable of graphical description of complicated systems. On the other hand, development of hardware and other peripheral computer resources and development of various computer software systems call for efficient and powerful operating systems, so that users can use the software and hardware items in an effective manner. The purpose of this article is to study the application of Petri Nets for modeling resource management in operating systems with the aim of optimal utilization of resources and Deadlock Avoidance in the Operating Systems.

  8. Test results on parabolic dish concentrators for solar thermal power systems

    Science.gov (United States)

    Jaffe, Leonard D.

    1989-01-01

    This paper presents results of development testing of various solar thermal parabolic dish concentrators. The concentrators were mostly designed for the production of electric power using dish-mounted Rankine, Brayton or Stirling cycle engines, intended to be produced at low cost. Measured performance for various dishes included optical efficiencies ranging from 0.32 to 0.86 at a geometric concentration ratio of 500, and from about 0.09 to 0.85 at a geometric concentration ratio of 3000. Some malfunctions were observed. The tests should provide operating information of value in developing concentrators with improved performance and reduced maintenance.

  9. Test results on parabolic dish concentrators for solar thermal power systems

    Science.gov (United States)

    Jaffe, Leonard D.

    1989-01-01

    This paper presents results of development testing of various solar thermal parabolic dish concentrators. The concentrators were mostly designed for the production of electric power using dish-mounted Rankine, Brayton or Stirling cycle engines, intended to be produced at low cost. Measured performance for various dishes included optical efficiencies ranging from 0.32 to 0.86 at a geometric concentration ratio of 500, and from about 0.09 to 0.85 at a geometric concentration ratio of 3000. Some malfunctions were observed. The tests should provide operating information of value in developing concentrators with improved performance and reduced maintenance.

  10. Modelling of Biometric Identification System with Given Parameters Using Colored Petri Nets

    Science.gov (United States)

    Petrosyan, G.; Ter-Vardanyan, L.; Gaboutchian, A.

    2017-05-01

    Biometric identification systems use given parameters and function on the basis of Colored Petri Nets as a modelling language developed for systems in which communication, synchronization and distributed resources play an important role. Colored Petri Nets combine the strengths of Classical Petri Nets with the power of a high-level programming language. Coloured Petri Nets have both, formal intuitive and graphical presentations. Graphical CPN model consists of a set of interacting modules which include a network of places, transitions and arcs. Mathematical representation has a well-defined syntax and semantics, as well as defines system behavioural properties. One of the best known features used in biometric is the human finger print pattern. During the last decade other human features have become of interest, such as iris-based or face recognition. The objective of this paper is to introduce the fundamental concepts of Petri Nets in relation to tooth shape analysis. Biometric identification systems functioning has two phases: data enrollment phase and identification phase. During the data enrollment phase images of teeth are added to database. This record contains enrollment data as a noisy version of the biometrical data corresponding to the individual. During the identification phase an unknown individual is observed again and is compared to the enrollment data in the database and then system estimates the individual. The purpose of modeling biometric identification system by means of Petri Nets is to reveal the following aspects of the functioning model: the efficiency of the model, behavior of the model, mistakes and accidents in the model, feasibility of the model simplification or substitution of its separate components for more effective components without interfering system functioning. The results of biometric identification system modeling and evaluating are presented and discussed.

  11. Optimal management of reconfigurable manufacturing system modeling with Petri nets developed three-dimensional - RPD3D

    Science.gov (United States)

    Teodor, F.; Marinescu, V.; Epureanu, A.

    2016-11-01

    Modeling of reconfigurable manufacturing systems would have done using existing Petri net types, but the complexity and dynamics of the new manufacturing system, mainly data reconfiguration feature, required looking for a more compact representation with many variables that to model as accurately not only the normal operation of the production system but can capture and model and reconfiguration process. Thus, it was necessary to create a new class of Petri nets, called RPD3D (Developed Petri nets with three dimensional) showing the name of both lineage (new class derived from Petri nets developed, created in 2000 by Prof. Dr. Ing Vasile Marinescu in his doctoral thesis) [1], but the most important of the new features defining (transformation from one 2D model into a 3D model).The idea was to introduce the classical model of a Petri third dimension to be able to overlay multiple levels (layers) formed in 2D or 3D Petri nets that interact with each other (receiving or giving commands to enable or disable the various modules together simulating the operation of reconfigurable manufacturing systems). The aim is to present a new type of Petri nets called RPD3D - Developed Petri three-dimensional model used for optimal control and simulation of reconfigurable manufacturing systems manufacture of products such systems.

  12. Design and analysis of a Petri net model of the Von Hippel-Lindau (VHL tumor suppressor interaction network.

    Directory of Open Access Journals (Sweden)

    Giovanni Minervini

    Full Text Available Von Hippel-Lindau (VHL syndrome is a hereditary condition predisposing to the development of different cancer forms, related to germline inactivation of the homonymous tumor suppressor pVHL. The best characterized function of pVHL is the ubiquitination dependent degradation of Hypoxia Inducible Factor (HIF via the proteasome. It is also involved in several cellular pathways acting as a molecular hub and interacting with more than 200 different proteins. Molecular details of pVHL plasticity remain in large part unknown. Here, we present a novel manually curated Petri Net (PN model of the main pVHL functional pathways. The model was built using functional information derived from the literature. It includes all major pVHL functions and is able to credibly reproduce VHL syndrome at the molecular level. The reliability of the PN model also allowed in silico knockout experiments, driven by previous model analysis. Interestingly, PN analysis suggests that the variability of different VHL manifestations is correlated with the concomitant inactivation of different metabolic pathways.

  13. Plastics Technology.

    Science.gov (United States)

    Barker, Tommy G.

    This curriculum guide is designed to assist junior high schools industrial arts teachers in planning new courses and revising existing courses in plastics technology. Addressed in the individual units of the guide are the following topics: introduction to production technology; history and development of plastics; safety; youth leadership,…

  14. A review of test results on parabolic dish solar thermal power modules with dish-mounted Rankine engines and for production of process steam

    Science.gov (United States)

    Jaffe, Leonard D.

    1988-01-01

    This paper presents results of development testing of various solar thermal parabolic dish modules and assemblies. Most of the tests were at modules and assemblies that used a dish-mounted, organic Rankine cycle turbine for production of electric power. Some tests were also run on equipment for production of process steam or for production of electricity using dish-mounted reciprocating steam engines. These tests indicate that early modules achieve efficiencies of about 18 percent in converting sunlight to electricity (excluding the inverter but including parasitics). A number of malfunctions occurred. The performance measurements, as well as the malfunctions and other operating experience, provided information that should be of value in developing systems with improved performance and reduced maintenance.

  15. DEADLOCK-FREE SCHEDULING METHOD BASED ON PETRI NET AND GA

    Institute of Scientific and Technical Information of China (English)

    Xu Gang; Wu Zhiming

    2003-01-01

    An efficient algorithm for finding an optimal deadlock-free schedule in a manufacturing system with very limited buffer is presented. This algorithm is based on the effective genetic algorithm (GA) search method, and a formal Petri net structure is introduced to detect the token player assuring deadlock-free. In order to make the scheduling strategy generated by GA meet the required constraint of deadlock-free, Petri net is involved to make the implementation of the job scheduling in an FMS deadlock-free. The effectiveness and efficiency of the proposed approach is illustrated by using an example.

  16. Modelling Feature Interaction Patterns in Nokia Mobile Phones using Coloured Petri Nets and Design/CPN

    DEFF Research Database (Denmark)

    Lorentsen, Louise; Tuovinen, Antti-Pekka; Xu, Jianli

    2002-01-01

    This paper describes the first results of a project on modelling of important feature interaction patterns of Nokia mobile phones using Coloured Petri Nets. A modern mobile phone supports many features: voice and data calls, text messaging, personal information management (phonebook and calendar....... In this paper, we look at the problem of feature interaction in the user interface of Nokia mobile phones. We present a categorization of feature interactions and describe our approach to the modelling of feature interactions using Coloured Petri Nets (CP-nets or CPN). The CPN model is extended...

  17. A Forward Reachability Algorithm for Bounded Timed-Arc Petri Nets

    DEFF Research Database (Denmark)

    David, Alexandre; Jacobsen, Lasse; Jacobsen, Morten

    2012-01-01

    in the presence of monotonicity-breaking features like age invariants and inhibitor arcs. We implement the algorithm within the model-checkerTAPAAL and the experimental results document an encouraging performance compared to verification approaches that translate TAPN models to UPPAAL timed automata.......Timed-arc Petri nets (TAPN) are a well-known time extension of thePetri net model and several translations to networks of timedautomata have been proposed for this model.We present a direct, DBM-basedalgorithm for forward reachability analysis of bounded TAPNs extended with transport arcs...

  18. STOCHASTIC OBJECT-ORIENTED PETRI NETS (SOPNS) AND ITS APPLICATION IN MODELING OF MANUFACTURING SYSTEM RELIABILITY

    Institute of Scientific and Technical Information of China (English)

    Jiang Zhibin; He Junming

    2003-01-01

    Object-oriented Petri nets (OPNs) is extended into stochastic object-oriented Petri nets (SOPNs) by associating the OPN of an object with stochastic transitions and introducing stochastic places. The stochastic transition of the SOPNs of a production resources can be used to model its reliability, while the SOPN of a production resource can describe its performance with reliability considered. The SOPN model of a case production system is built to illustrate the relationship between the system's performances and the failures of individual production resources.

  19. Representing Resources in Petri Net Models: Hardwiring or Soft-coding?

    OpenAIRE

    2011-01-01

    This paper presents an interesting design problem in developing a new tool for discrete-event dynamic systems (DEDS). A new tool known as GPenSIM was developed for modeling and simulation of DEDS; GPenSIM is based on Petri Nets. The design issue this paper talks about is whether to represent resources in DEDS hardwired as a part of the Petri net structure (which is the widespread practice) or to soft code as common variables in the program code. This paper shows that soft coding resources giv...

  20. Distinguishing Environment and System in Coloured Petri Net Models of Reactive Systems

    DEFF Research Database (Denmark)

    Tjell, Simon

    2007-01-01

    This paper introduces and formally defines the environment-and-system-partitioned property for behavioral models of reactive systems expressed in the formal modeling language Coloured Petri Net. The purpose of the formalization is to make it possible to automatically validate any CPN model with r...... code-generation from models. A prototypical tool has been implemented for performing the structural analysis of Coloured Petri Net models and the principles of this tool is described. The aim of the paper is to make the guidelines and their formalized definitions along with a proof...

  1. Assessing the Graphical and Algorithmic Structure of Hierarchical Coloured Petri Net Models

    Directory of Open Access Journals (Sweden)

    George Benwell

    1994-11-01

    Full Text Available Petri nets, as a modelling formalism, are utilised for the analysis of processes, whether for explicit understanding, database design or business process re-engineering. The formalism, however, can be represented on a virtual continuum from highly graphical to largely algorithmic. The use and understanding of the formalism will, in part, therefore depend on the resultant complexity and power of the representation and, on the graphical or algorithmic preference of the user. This paper develops a metric which will indicate the graphical or algorithmic tendency of hierarchical coloured Petri nets.

  2. Automatic Translation of a Process Level Petri-Net to a Ladder Diagram

    Science.gov (United States)

    Cohen*, Yuval; Wang, Ming-En; Bidanda, Bopaya

    Major part of discrete industrial automation hardware is controlled by Programmable Logic Controllers (PLCs). While Petri-nets (PNs) have been proposed by many researchers for modelling shop floor discrete control, the majority of the world PLCs are programmed using ladder diagrams (LD) and significant portion of them cannot be programmed using another language. This paper proposes hierarchical approach to translating PN to LD: for describing the high level process, it introduces automatic translation technique of process level PN, while utilizing a recently developed method (for translating PN to Boolean logic) for translating the embedded tasks to a LD. Interestingly, the generated LD code enables the reconstruction of the original Petri-net.

  3. Metagenomic data of fungal internal transcribed spacer from serofluid dish, a traditional Chinese fermented food

    Directory of Open Access Journals (Sweden)

    Peng Chen

    2016-03-01

    Full Text Available Serofluid dish (or Jiangshui, in Chinese, a traditional food in the Chinese culture for thousands of years, is made from vegetables by fermentation. In this work, microorganism community of the fermented serofluid dish was investigated by the culture-independent method. The metagenomic data in this article contains the sequences of fungal internal transcribed spacer (ITS regions of rRNA genes from 12 different serofluid dish samples. The metagenome comprised of 50,865 average raw reads with an average of 8,958,220 bp and G + C content is 45.62%. This is the first report on metagenomic data of fungal ITS from serofluid dish employing Illumina platform to profile the fungal communities of this little known fermented food from Gansu Province, China. The Metagenomic data of fungal internal transcribed spacer can be accessed at NCBI, SRA database accession no. SRP067411.

  4. Metagenomic data of fungal internal transcribed spacer from serofluid dish, a traditional Chinese fermented food.

    Science.gov (United States)

    Chen, Peng; Zhao, Yang; Wu, Zhengrong; Liu, Ronghui; Xu, Ruixiang; Yan, Lei; Li, Hongyu

    2016-03-01

    Serofluid dish (or Jiangshui, in Chinese), a traditional food in the Chinese culture for thousands of years, is made from vegetables by fermentation. In this work, microorganism community of the fermented serofluid dish was investigated by the culture-independent method. The metagenomic data in this article contains the sequences of fungal internal transcribed spacer (ITS) regions of rRNA genes from 12 different serofluid dish samples. The metagenome comprised of 50,865 average raw reads with an average of 8,958,220 bp and G + C content is 45.62%. This is the first report on metagenomic data of fungal ITS from serofluid dish employing Illumina platform to profile the fungal communities of this little known fermented food from Gansu Province, China. The Metagenomic data of fungal internal transcribed spacer can be accessed at NCBI, SRA database accession no. SRP067411.

  5. Regional food dishes in the Brazilian National School Food Program: Acceptability and nutritional composition

    National Research Council Canada - National Science Library

    Cunha, Diogo thimoteo da; Gonçalves, Hélida Ventura Barbosa; Lima, Aline Fátima Andrade de; Martins, Paula Andrea; Rosso, Veridiana Vera de; Stedefeldt, Elke

    2014-01-01

    Objective: the objective of this study was to evaluate the nutritional composition and describe the acceptability of regional culinary dishes served to students from public schools of rural and urban areas.Methods...

  6. Design, Analysis and Optimization of a Solar Dish/Stirling System

    OpenAIRE

    Seyyed Danial Nazemi; Mehrdad Boroushaki

    2016-01-01

    In this paper, a mathematical model by which the thermal and physical behavior of a solar dish/Stirling system was investigated, then the system was designed, analysed and optimized. In this regard, all of heat losses in a dish/Stirling system were calculated, then, the output net-work of the Stirling engine was computed, and accordingly, the system efficiency was worked out. These heat losses include convection and conduction heat losses, radiation heat losses by emission in the cavity recei...

  7. DISH STIRLING SYSTEM POTENTIAL ASSESSMENT FOR EIGHT MAIN SITES IN MADAGASCAR

    OpenAIRE

    Praene, Jean-Philippe; Radanielina, Harimisa; Rakotondramiarana, Hery Tiana

    2016-01-01

    International audience; Solar energy is a green and attractive renewable energy source that can be converted for power generation. The objective of this work is to evaluate the potential of dish Stirling systems if they are used in the fourth worldwide largest island of Madagascar. For that purpose, a theoretical model of the dish Stirling system based on the geometrical configuration and heat transfer was developed and coded on Matlab. Simulations were run to investigate the energy efficienc...

  8. Faults Analysis and Diagnosis of DR J-460 Dish Centrifugal Separator's Helical Gear

    Institute of Scientific and Technical Information of China (English)

    MA Xiao-jian; GAN Xue-hui

    2004-01-01

    The main faults of dish centrifugal separator's helical gear are described in this paper. In order to diagnose the DR J-460 dish centrifugal separator correctly, the vibration is tested with a helical gear under both normal and abnormal conditions. After comparing several general methods of the gear's fault feature extraction, a new convenient and effective method is presented on the basis of analyzing the vibration spectrum under different rotary velocities.

  9. Dish Stirling High Performance Thermal Storage FY14Q4 Quad Chart

    Energy Technology Data Exchange (ETDEWEB)

    Andraka, Charles E. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States)

    2014-10-01

    The goals of this project are to demonstrate the feasibility of significant thermal storage for dish stirling systems to leverage their existing high performance to greater capacity; demonstrate key components of a latent storage and transport system enabling on-dish storage with low energy losses; and provide a technology path to a 25kWe system with 6 hours of storage.

  10. Sterile polystyrene culture dishes induce transformation of polyps into medusae in Aurelia aurita (Scyphozoa, Cnidaria).

    Science.gov (United States)

    Herrmann, Klaus; Siefker, Barbara; Berking, Stefan

    2003-01-01

    Polyps of Aurelia aurita produce medusae once a year. Under laboratory conditions this process, termed strobilation, can be induced by lowering the incubation temperature for about two weeks. Here we report a fast induction of strobilation by sterile polystyrene culture dishes. The effect is abolished when the culture dishes are washed twice with hot water prior to the experiment. We recommend that polystyrene cultureware should be pre-washed whenever there is an indication of unusual effects.

  11. Verification of Timed Healthcare Workflows Using Component Timed-Arc Petri Nets

    DEFF Research Database (Denmark)

    Bertolini, Cristiano; Liu, Zhiming; Srba, Jiri

    2013-01-01

    and a support for compositional reasoning. We use the formalism of component-based timed-arc Petri Nets (CTAPN) for modular modelling of collaborative healthcare workflows and demonstrate how the model checker TAPAAL supports the verification of their functional and non-functional requirements. To this end, we...

  12. Coloured Petri Nets: Basic Concepts, Analysis Methods and Practical Use. Vol. 1, Basic Concepts

    DEFF Research Database (Denmark)

    Jensen, Kurt

    This three-volume work presents a coherent description of the theoretical and practical aspects of coloured Petri nets. These CP-nets are shown to be a full-fledged language for the design, specification, simulation, validation and implementation of large software systems. The introductory first...

  13. RECONFIGURABLE PRODUCTION LINE MODELING AND SCHEDULING USING PETRI NETS AND GENETIC ALGORITHM

    Institute of Scientific and Technical Information of China (English)

    XIE Nan; LI Aiping

    2006-01-01

    In response to the production capacity and functionality variations, a genetic algorithm (GA) embedded with deterministic timed Petri nets(DTPN) for reconfigurable production line(RPL) is proposed to solve its scheduling problem. The basic DTPN modules are presented to model the corresponding variable structures in RPL, and then the scheduling model of the whole RPL is constructed. And in the scheduling algorithm, firing sequences of the Petri nets model are used as chromosomes, thus the selection, crossover, and mutation operator do not deal with the elements in the problem space, but the elements of Petri nets model. Accordingly, all the algorithms for GA operations embedded with Petri nets model are proposed. Moreover, the new weighted single-objective optimization based on reconfiguration cost and E/T is used. The results of a DC motor RPL scheduling suggest that the presented DTPN-GA scheduling algorithm has a significant impact on RPL scheduling, and provide obvious improvements over the conventional scheduling method in practice that meets duedate, minimizes reconfiguration cost, and enhances cost effectivity.

  14. Model checking of time Petri nets using the state class timed automaton

    DEFF Research Database (Denmark)

    Lime, Didier; Roux, Olivier H.

    2006-01-01

    In this paper, we propose a method for building the state class graph of a bounded time Petri net (TPN) as a timed automaton (TA), which we call the state class timed automaton. We consider bounded TPN, whose underlying net is not necessarily bounded. We prove that our translation preserves...

  15. CPN/Tools: A Tool for Editing and Simulating Coloured Petri Nets

    DEFF Research Database (Denmark)

    Jensen, Kurt; Christensen, Søren; Ravn, Katrine

    2001-01-01

    CPN/Tools is a major redesign of the popular Design/CPN tool for editing, simulation and state space analysis of Coloured Petri Nets. The new interface is based on advanced interaction techniques, including bi-manual interaction, toolglasses and marking menus and a new metaphor for managing...

  16. Modeling function calls in program control flow in terms of Petri Nets

    Directory of Open Access Journals (Sweden)

    Dmitriy Kharitonov

    Full Text Available This article presents a method for representing the C/C++ function call in terms of compositional Petri Nets. Principles of modeling function and function call in the program are described. Formal composition operations to construct program model from mod ...

  17. Comparing the Expressiveness of Timed Automata and Timed Extensions of Petri Nets

    DEFF Research Database (Denmark)

    Srba, Jiri

    2008-01-01

    were suggested as real-time extensions of several well-known untimed models. The most studied formalisms include Networks of Timed Automata which extend the model of communicating finite-state machines with a finite number of real-valued clocks, and timed extensions of Petri nets where the added time...

  18. Modeling and Control of Welding Flexible Manufacturing Cell Using Petri Net

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    A new welding flexible manufacturing cell (WFMC) with intelligent welding sensors was investigated. Based on the analysis of information flow in WFMC, automation Petri net control model has been studied, which can be extended to complex welding flexible manufacturing system in the future.

  19. Coloured Petri Nets: Basic Concepts, Analysis Methods and Practical Use. Vol. 2, Analysis Methods

    DEFF Research Database (Denmark)

    Jensen, Kurt

    This three-volume work presents a coherent description of the theoretical and practical aspects of coloured Petri nets (CP-nets). The second volume contains a detailed presentation of the analysis methods for CP-nets. They allow the modeller to investigate dynamic properties of CP-nets. The main...

  20. A Mean-Value Analysis of Stochastic Petri Net Models of Slotted Rings

    NARCIS (Netherlands)

    Coyle, Andrew; Haverkort, Boudewijn R.; Henderson, William; Pearce, Charles E.M.

    1996-01-01

    In this paper, we analyse Stochastic Petri Net (SPN) models of slotted-ring networks. We show that a simple SPN model of a slotted-ring network, which exhibits a product-form solution, yields similar results to a more detailed SPN model that has to be analysed by numerical means. Furthermore, we dem

  1. Net Operations (Ⅱ)——The Iterated Addition Operation of Petri Nets

    Institute of Scientific and Technical Information of China (English)

    蒋昌俊

    1995-01-01

    This paper presents the iterated addition operation of Petri nets and discusses its application in analysis and synthesis of cycle type systems and star type systems.A group of necessary and sufficient conditions for analysis of structural properties is obtained.In addition sufficient conditions for general systems are obtained.

  2. Plastic bronchitis

    National Research Council Canada - National Science Library

    Singhi, Anil Kumar; Vinoth, Bharathi; Kuruvilla, Sarah; Sivakumar, Kothandam

    2015-01-01

    Plastic bronchitis, a rare but serious clinical condition, commonly seen after Fontan surgeries in children, may be a manifestation of suboptimal adaptation to the cavopulmonary circulation with unfavorable hemodynamics...

  3. Plastic Fishes

    CERN Multimedia

    Trettnak, Wolfgang

    2015-01-01

    In terms of weight, the plastic pollution in the world’s oceans is estimated to be around 300,000 tonnes. This plastic comes from both land-based and ocean-based sources. A lecture at CERN by chemist Wolfgang Trettnak addressed this issue and highlighted the role of art in raising people’s awareness. The slideshow below gives you a taste of the artworks by Wolfgang Trettnak and Margarita Cimadevila.

  4. Plastic Bridge

    Institute of Scientific and Technical Information of China (English)

    履之

    1994-01-01

    Already ubiquitous in homes and cars, plastic is now appearing inbridges. An academic-industrial consortium based at the University ofCalifornia in San Diego is launching a three-year research program aimed atdeveloping the world’s first plastic highway bridge, a 450-foot span madeentirely from glass-,carbon,and polymer-fiber-reinforced composite mate-rials, the stuff of military aircraft. It will cross Interstate 5 to connect thetwo sides of the school’s campus.

  5. Aspects regarding at 13C isotope separation column control using Petri nets system

    Science.gov (United States)

    Boca, M. L.; Ciortea, M. E.

    2015-11-01

    This paper is intended to show that Petri nets can be also applicable in the chemical industry. It used linear programming, modeling underlying Petri nets, especially discrete event systems for isotopic separation, the purpose of considering and control events in real-time through graphical representations. In this paper it is simulate the control of 13C Isotope Separation column using Petri nets. The major problem with 13C comes from the difficulty of obtaining it and raising its natural fraction. Carbon isotopes can be obtained using many methods, one of them being the cryogenic distillation of carbon monoxide. Some few aspects regarding operating conditions and the construction of such cryogenic plants are known today, and even less information are available as far as the separation process modeling and control are concerned. In fact, the efficient control of the carbon monoxide distillation process represents a necessity for large-scale 13C production. Referring to a classic distillation process, some models for carbon isotope separation have been proposed, some based on mass, component and energy balance equations, some on the nonlinear wave theory or the Cohen equations. For modeling the system it was used Petri nets because in this case it is deal with discrete event systems. In use of the non-timed and with auxiliary times Petri model, the transport stream was divided into sections and these sections will be analyzed successively. Because of the complexity of the system and the large amount of calculations required it was not possible to analyze the system as a unitary whole. A first attempt to model the system as a unitary whole led to the blocking of the model during simulation, because of the large processing times.

  6. Runtime Verification of Pacemaker Functionality Using Hierarchical Fuzzy Colored Petri-nets.

    Science.gov (United States)

    Majma, Negar; Babamir, Seyed Morteza; Monadjemi, Amirhassan

    2017-02-01

    Today, implanted medical devices are increasingly used for many patients and in case of diverse health problems. However, several runtime problems and errors are reported by the relevant organizations, even resulting in patient death. One of those devices is the pacemaker. The pacemaker is a device helping the patient to regulate the heartbeat by connecting to the cardiac vessels. This device is directed by its software, so any failure in this software causes a serious malfunction. Therefore, this study aims to a better way to monitor the device's software behavior to decrease the failure risk. Accordingly, we supervise the runtime function and status of the software. The software verification means examining limitations and needs of the system users by the system running software. In this paper, a method to verify the pacemaker software, based on the fuzzy function of the device, is presented. So, the function limitations of the device are identified and presented as fuzzy rules and then the device is verified based on the hierarchical Fuzzy Colored Petri-net (FCPN), which is formed considering the software limits. Regarding the experiences of using: 1) Fuzzy Petri-nets (FPN) to verify insulin pumps, 2) Colored Petri-nets (CPN) to verify the pacemaker and 3) To verify the pacemaker by a software agent with Petri-network based knowledge, which we gained during the previous studies, the runtime behavior of the pacemaker software is examined by HFCPN, in this paper. This is considered a developing step compared to the earlier work. HFCPN in this paper, compared to the FPN and CPN used in our previous studies reduces the complexity. By presenting the Petri-net (PN) in a hierarchical form, the verification runtime, decreased as 90.61% compared to the verification runtime in the earlier work. Since we need an inference engine in the runtime verification, we used the HFCPN to enhance the performance of the inference engine.

  7. Using UML and Petri nets for visualization of business document flow

    Directory of Open Access Journals (Sweden)

    Ivana Rábová

    2012-01-01

    Full Text Available The article deals with two principles of business workflow modeling, Petri nets and UML notation, that are the acceptable approaches to business modeling and can be used also for business documents workflow. The special type of Petri nets, WF-nets and UML activity diagrams are used in this article and both modeling ways are presented on the concrete business workflow and then there are presented and specified their advantage and disadvantage for business documents flows. At beginning it is explained the word workflow in context business documents, its features, principles and using in business environment. After that it is clarified that the UML is OMG’s most-used specification, and the way the world models not only application structure, behavior, and architecture, but also business process, workflows and data structure. Activity diagram UML is good way to show how different workflows in the business are managed, how they start, go and stop. Diagrams also show many different decision paths that can be taken from start to finish. State charts can be used as a detail the transitions or changes of states when documents can go through in the business. They show how a documents moves from one state to another and the rules that govern that change. Petri-nets offer a graphical notation for stepwise processes that include choice, iteration, and concurrent execution. Unlike UML Petri nets have an exact mathematical definition of their execution semantics, with a well-developed mathematical theory for process analysis. In the article there are modeled a special type of Petri nets, the WF-nets. The practical part of article incorporates two models of concrete business documents workflows presented in these notations, their comparison and recommendation for using these diagrams in business process management.

  8. An analytical method for well-formed workflow/Petri net verification of classical soundness

    Directory of Open Access Journals (Sweden)

    Clempner Julio

    2014-12-01

    Full Text Available In this paper we consider workflow nets as dynamical systems governed by ordinary difference equations described by a particular class of Petri nets. Workflow nets are a formal model of business processes. Well-formed business processes correspond to sound workflow nets. Even if it seems necessary to require the soundness of workflow nets, there exist business processes with conditional behavior that will not necessarily satisfy the soundness property. In this sense, we propose an analytical method for showing that a workflow net satisfies the classical soundness property using a Petri net. To present our statement, we use Lyapunov stability theory to tackle the classical soundness verification problem for a class of dynamical systems described by Petri nets. This class of Petri nets allows a dynamical model representation that can be expressed in terms of difference equations. As a result, by applying Lyapunov theory, the classical soundness property for workflow nets is solved proving that the Petri net representation is stable. We show that a finite and non-blocking workflow net satisfies the sound property if and only if its corresponding PN is stable, i.e., given the incidence matrix A of the corresponding PN, there exists a Փ strictly positive m vector such that AՓ≤ 0. The key contribution of the paper is the analytical method itself that satisfies part of the definition of the classical soundness requirements. The method is designed for practical applications, guarantees that anomalies can be detected without domain knowledge, and can be easily implemented into existing commercial systems that do not support the verification of workflows. The validity of the proposed method is successfully demonstrated by application examples.

  9. GREEN PLASTIC: A NEW PLASTIC FOR PACKAGING

    OpenAIRE

    Mr. Pankaj Kumar*, Sonia

    2016-01-01

    This paper gives a brief idea about a new type of plastic called as bio-plastic or green plastic. Plastic is used as a packaging material for various products, but this plastic is made up of non renewable raw materials. There are various disadvantages of using conventional plastic like littering, CO2 production, non-degradable in nature etc. To overcome these problems a new type of plastic is discovered called bio-plastic or green plastic. Bio-plastic is made from renewable resources and also...

  10. Petri网的进程文法和进程语言%Process Grammar and Process Language of Petri Nets

    Institute of Scientific and Technical Information of China (English)

    吴哲辉; 张继军

    2002-01-01

    The concept of process grammar, based on the idea of vector grammar, for petri net is presented in this pa-per. The process language of a petri net can be generated by derivation according to its process grammar . The set ofbasic process section sequence represented by the process language of a petri net ∑is the same as that represented bythe process expression of ∑if ∑is bounded or fair. In the case of that∑is unbounded and unfair ,the set of all processof∑ can also be represented by its process language passed through parallel processing.

  11. Redes de Petri: Modelado e implementación de algoritmos para autómatas programables

    OpenAIRE

    Luis Diego Murillo

    2008-01-01

    El presente trabajo es una monografía orientada hacia la utilización del formalismo de las Redes de Petri, propuesto por Carl Petri en la descripción de Sistemas Dinámicos de Eventos Discretos (DEDS). Las Redes de Petri, cuyo acrónimo en inglés es PN, fueron utilizadas inicialmente para el análisis de algoritmos en la computación paralela o concurrente, pero dada la complejidad de los procesos productivos actuales, las PN son un método alternativo de diseño tanto para el procesoindustrial com...

  12. Plastic condoms.

    Science.gov (United States)

    1968-01-01

    Only simple equipment, simple technology and low initial capital investment are needed in their manufacture. The condoms can be made by people who were previously unskilled or only semi-skilled workers. Plastic condoms differ from those made of latex rubber in that the nature of the plastic film allows unlimited shelf-life. Also, the plastic has a higher degree of lubricity than latex rubber; if there is a demand for extra lubrication in a particular market, this can be provided. Because the plastic is inert, these condoms need not be packaged in hermetically sealed containers. All these attributes make it possible to put these condoms on the distributors' shelves in developing countries competitively with rubber condoms. The shape of the plastic condom is based on that of the lamb caecum, which has long been used as luxury-type condom. The plastic condom is made from plastic film (ethylene ethyl acrilate) of 0.001 inch (0.0254 mm.) thickness. In addition, a rubber ring is provided and sealed into the base of the condom for retention during coitus. The advantage of the plastic condom design and the equipment on which it is made is that production can be carried out either in labour-intensive economy or with varying degrees of mechanization and automation. The uniform, finished condom if made using previously untrained workers. Training of workers can be done in a matter of hours on the two machines which are needed to produce and test the condoms. The plastic film is provided on a double wound roll, and condom blanks are prepared by means of a heat-sealing die on the stamping machine. The rubber rings are united to the condom blanks on an assembly machine, which consists of a mandrel and heat-sealing equipment to seal the rubber ring to the base of the condom. Built into the assembly machine is a simple air-testing apparatus that can detect the smallest pinhole flaw in a condom. The manufacturing process is completed by unravelling the condom from the assembly

  13. Cultured articular chondrocytes sheets for partial thickness cartilage defects utilizing temperature-responsive culture dishes

    Directory of Open Access Journals (Sweden)

    N Kaneshiro

    2007-05-01

    Full Text Available The extracellular matrix (ECM of articular cartilage has several functions that are unique to joints. Although a technique for transplanting cultured chondrocytes has already been introduced, it is difficult to collect intact ECM when using enzymes to harvest samples. Temperature-responsive culture dishes have already been clinically applied in the fields of myocardial and corneal transplantation. Earlier studies have shown that a sheet of cultured cells with intact ECM and adhesive factors can be harvested using such culture dishes, which allow the surface properties of the dish to be reversibly altered by changing the temperature. Human chondrocytes were subjected to enzymatic digestion and then were seeded in temperature-responsive culture dishes. A sheet of chondrocytes was harvested by only reducing the temperature after the cultured cells reached confluency. A real-time PCR analysis of the chondrocyte sheets confirmed that type II collagen, aggrecan, and fibronectin were present. These results suggested that, although chondrocytes undergo dedifferentiation in a monolayer culture, multilayer chondrocyte sheets grown in a similar environment to that of three-dimensional culture may be able to maintain a normal phenotype. A histological examination suggested that multilayer chondrocyte sheets could thus prevent the loss of proteoglycans because the area covered by the sheets was well stained by safranin-O. The present experiments suggested that temperature-responsive culture dishes are useful for obtaining cultured chondrocytes, which may then be clinically employed as a substitute for periosteal patches because such sheets can be applied without a scaffold.

  14. Thermal buffering of receivers for parabolic dish solar thermal power plants

    Science.gov (United States)

    Manvi, R.; Fujita, T.; Gajanana, B. C.; Marcus, C. J.

    1980-01-01

    A parabolic dish solar thermal power plant comprises a field of parabolic dish power modules where each module is composed of a two-axis tracking parabolic dish concentrator which reflects sunlight (insolation) into the aperture of a cavity receiver at the focal point of the dish. The heat generated by the solar flux entering the receiver is removed by a heat transfer fluid. In the dish power module, this heat is used to drive a small heat engine/generator assembly which is directly connected to the cavity receiver at the focal point. A computer analysis is performed to assess the thermal buffering characteristics of receivers containing sensible and latent heat thermal energy storage. Parametric variations of the thermal inertia of the integrated receiver-buffer storage systems coupled with different fluid flow rate control strategies are carried out to delineate the effect of buffer storage, the transient response of the receiver-storage systems and corresponding fluid outlet temperature. It is concluded that addition of phase change buffer storage will substantially improve system operational characteristics during periods of rapidly fluctuating insolation due to cloud passage.

  15. Dorsal vertebral column abnormalities in dogs with disseminated idiopathic skeletal hyperostosis (DISH).

    Science.gov (United States)

    Decker, S De; Volk, H A

    2014-06-21

    Although disseminated idiopathic skeletal hyperostosis (DISH) most often affects the ventral aspect of the vertebral column, this study evaluated the occurrence, nature and clinical relevance of dorsal vertebral column abnormalities in 10 dogs with DISH for which CT or MRI and a complete neurological examination were available. Dorsal vertebral column abnormalities were present in eight dogs and included articular process hypertrophy (n=7 dogs), periarticular new bone formation (n=1), pseudoarthrosis between spinous processes (n=4) and thickening of the dorsal lamina (n=4). These dorsal vertebral abnormalities caused clinically relevant vertebral canal stenosis in six dogs and were the only cause of clinical signs in four of these dogs. Although the lumbosacral joint was not affected by DISH, these six dogs demonstrated lumbosacral vertebral canal stenosis and clinical signs of cauda equina compression, which included paraparesis (n=5 dogs), lumbosacral pain (n=4), urinary incontinence (n=4), faecal incontinence (n=1) and urinary and faecal incontinence (n=1). There is a possible association between DISH and hypertrophy of dorsal vertebral structures, potentially resulting in vertebral canal stenosis. Although these changes occurred at segments fused by DISH, they predominantly affected adjacent non-affected segments.

  16. The Hierarchical Structure of the Workflow Process Definition and Normal Petri Net%工作流过程定义中的分层结构与正则Petri网

    Institute of Scientific and Technical Information of China (English)

    王斌君; 郝克刚

    2003-01-01

    The abstract level problem and the classification of the abstract level problem in the workflow process model are discussed. The formalized problem of the abstract level problem in the process model is researched. The concept and definition of the petri net with end-transition and normal petri net according to the control abstract level problem are put forward and discussed. The equivalence of general Petri Net and general Petri Net is proved by the petri net with priori relationship.

  17. Plastic Bronchitis.

    Science.gov (United States)

    Rubin, Bruce K

    2016-09-01

    Plastic bronchitis is an uncommon and probably underrecognized disorder, diagnosed by the expectoration or bronchoscopic removal of firm, cohesive, branching casts. It should not be confused with purulent mucous plugging of the airway as seen in patients with cystic fibrosis or bronchiectasis. Few medications have been shown to be effective and some are now recognized as potentially harmful. Current research directions in plastic bronchitis research include understanding the genetics of lymphatic development and maldevelopment, determining how abnormal lymphatic malformations contribute to cast formation, and developing new treatments. Copyright © 2016 Elsevier Inc. All rights reserved.

  18. Mixed plastics recycling technology

    CERN Document Server

    Hegberg, Bruce

    1995-01-01

    Presents an overview of mixed plastics recycling technology. In addition, it characterizes mixed plastics wastes and describes collection methods, costs, and markets for reprocessed plastics products.

  19. Petri Net Decomposition Approach for Bi-Objective Routing for AGV Systems Minimizing Total Traveling Time and Equalizing Delivery Time

    National Research Council Canada - National Science Library

    EDA, Shuhei; NISHI, Tatsushi; MARIYAMA, Toshisada; KATAOKA, Satomi; SHODA, Kazuya; MATSUMURA, Katsuhiko

    2012-01-01

    .... The objective is minimizing total traveling time and equalizing delivery time simultaneously. The dispatching and conflict-free routing problem for AGVs is represented as a bi-objective optimal firing sequence problem for Petri Net...

  20. Petri nets in Snoopy: a unifying framework for the graphical display, computational modelling, and simulation of bacterial regulatory networks.

    Science.gov (United States)

    Marwan, Wolfgang; Rohr, Christian; Heiner, Monika

    2012-01-01

    Using the example of phosphate regulation in enteric bacteria, we demonstrate the particular suitability of stochastic Petri nets to model biochemical phenomena and their simulative exploration by various features of the software tool Snoopy.

  1. Elaborating Naturalized Critical Realism: Response to Ruth Groff, Dave Elder-Vass, Daniel Little and Petri Ylikoski

    Directory of Open Access Journals (Sweden)

    Kaidesoja Tuukka

    2015-09-01

    Full Text Available This paper is a reply to the discussions of Ruth Groff, Dave Elder-Vass, Daniel Little, and Petri Ylikoski of Tuukka Kaidesoja (2013: Naturalizing Critical Realist Social Ontology (London: Routledge.

  2. The Nonlinear Instability Modes of Dished Shallow Shells under Circular Line Loads

    Directory of Open Access Journals (Sweden)

    Liu Chang-Jiang

    2011-01-01

    Full Text Available This paper investigated the nonlinear stability problem of dished shallow shells under circular line loads. We derived the dimensionless governing differential equations of dished shallow shell under circular line loads according to the nonlinear theory of plates and shells and solved the governing differential equations by combing the free-parameter perturbation method (FPPM with spline function method (SFM to analyze the nonlinear instability modes of dished shallow shell under circular line loads. By analyzing the nonlinear instability modes and combining with concrete computational examples, we obtained the variation rules of the maximum deflection area of initial instability with different geometric parameters and loading action positions and discussed the relationship between the initial instability area and the maximum deflection area of initial instability. The results obtained from this paper provide some theoretical basis for engineering design and instability prediction and control of shallow-shell structures.

  3. Comparison of advanced engines for parabolic dish solar thermal power plants

    Science.gov (United States)

    Fujita, T.; Bowyer, J. M.; Gajanana, B. C.

    1980-01-01

    A paraboloidal dish solar thermal power plant produces electrical energy by a two-step conversion process. The collector subsystem is composed of a two-axis tracking paraboloidal concentrator and a cavity receiver. The concentrator focuses intercepted sunlight (direct, normal insolation) into a cavity receiver whose aperture encircles the focal point of the concentrator. At the internal wall of the receiver the electromagnetic radiation is converted to thermal energy. A heat engine/generator assembly then converts the thermal energy captured by the receiver to electricity. Developmental activity has been concentrated on small power modules which employ 11- to 12-meter diameter dishes to generate nominal power levels of approximately 20 kWe. A comparison of advanced heat engines for the dish power module is presented in terms of the performance potential of each engine with its requirements for advanced technology development. Three advanced engine possibilities are the Brayton (gas turbine), Brayton/Rankine combined cycle, and Stirling engines.

  4. Sky reconstruction from transit visibilities: PAON-4 and Tianlai Dish Array

    CERN Document Server

    Zhang, Jiao; Chen, Xuelei; Campagne, Jean-Eric; Magneville, Christophe; Wu, Fengquan

    2016-01-01

    The spherical harmonics $m$-mode decomposition is a powerful sky map reconstruction method suitable for radio interferometers operating in transit mode. It can be applied to various configurations, including dish arrays and cylinders. We describe the computation of the instrument response function, the point spread function (PSF), transfer function, the noise covariance matrix and noise power spectrum. The analysis in this paper is focused on dish arrays operating in transit mode. We show that arrays with regular spacing have more pronounced side lobes as well as structures in their noise power spectrum, compared to arrays with irregular spacing, specially in the north-south direction. A good knowledge of the noise power spectrum $C^{\\mathrm{noise}}(\\ell)$ is essential for intensity mapping experiments as non uniform $C^{\\mathrm{noise}}(\\ell)$ is a potential problem for the measurement of the HI power spectrum. Different configurations have been studied to optimise the PAON-4 and Tianlai dish array layouts. W...

  5. Plastic fish

    CERN Multimedia

    Antonella Del Rosso

    2015-01-01

    In terms of weight, the plastic pollution in the world’s oceans is estimated to be around 300,000 tonnes. This plastic comes from both land-based and ocean-based sources. A lecture at CERN by chemist Wolfgang Trettnak addressed this issue and highlighted the role of art in raising people’s awareness.   Artwork by Wolfgang Trettnak. Packaging materials, consumer goods (shoes, kids’ toys, etc.), leftovers from fishing and aquaculture activities… our oceans and beaches are full of plastic litter. Most of the debris from beaches is plastic bottles. “PET bottles have high durability and stability,” explains Wolfgang Trettnak, a chemist by education and artist from Austria, who gave a lecture on this topic organised by the Staff Association at CERN on 26 May. “PET degrades very slowly and the estimated lifetime of a bottle is 450 years.” In addition to the beach litter accumulated from human use, rivers bring several ki...

  6. Plastic zonnecellen

    NARCIS (Netherlands)

    Roggen, Marjolein

    1998-01-01

    De zonnecel van de toekomst is in de maak. Onderzoekers van uiteenlopend pluimage werken eendrachtig aan een plastic zonnecel. De basis is technisch gelegd met een optimale, door invallend licht veroorzaakte, vorming van ladingdragers binnen een composiet van polymeren en buckyballs. Nu is het zaak

  7. Modeling and Simulation of Metallurgical Process Based on Hybrid Petri Net

    Science.gov (United States)

    Ren, Yujuan; Bao, Hong

    2016-11-01

    In order to achieve the goals of energy saving and emission reduction of iron and steel enterprises, an increasing number of modeling and simulation technologies are used to research and analyse metallurgical production process. In this paper, the basic principle of Hybrid Petri net is used to model and analyse the Metallurgical Process. Firstly, the definition of Hybrid Petri Net System of Metallurgical Process (MPHPNS) and its modeling theory are proposed. Secondly, the model of MPHPNS based on material flow is constructed. The dynamic flow of materials and the real-time change of each technological state in metallurgical process are simulated vividly by using this model. The simulation process can implement interaction between the continuous event dynamic system and the discrete event dynamic system at the same level, and play a positive role in the production decision.

  8. Applying a semantic information Petri Net modeling method to AUV systems design

    Institute of Scientific and Technical Information of China (English)

    FENG Xiao-ning; WANG Shuo; WANG Zhuo; LIU Qun

    2008-01-01

    This paper informally introduces colored object-oriented Petri Nets(COOPN) with the application of the AUV system. According to the characteristic of the AUV system's running environment,the object-oriented method is used in this paper not only to dispart system modules but also construct the refined running model of AUV system,then the colored Petri Net method is used to establish hierarchically detailed model in order to get the performance analyzing information of the system. After analyzing the model implementation,the errors of architecture designing and function realization can be found. If the errors can be modified on time,the experiment time in the pool can be reduced and the cost can be saved.

  9. Fuzzy reasoning model using fuzzy Petri Nets for the monitoring of robotic assembly

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    This paper presented a fuzzy Petri net model to deal with the monitoring of robotic assembly. Based on the fuzzy Petri net model. All efficient composite reasoning mode was proposed to perform fuzzy reasoning automatically. It can determine whether there exists an antecedent-consequence relationship between two contact states. Furthermore, various types of sensor signals can be converted to the same form of real values between zero and one, and the contradiction among large number, high degree of truth and importance of input conditions can be resolved very well by introducing the weight factors and priorities for sensor signals. Finally, a pegin-the-hole example was given to illustrate the reasonability and feasibility of the proposed model.

  10. Managing Changes in Citizen-Centric Healthcare Service Platform using High Level Petri Net

    Directory of Open Access Journals (Sweden)

    Sabri MTIBAA

    2012-08-01

    Full Text Available The healthcare organizations are facing a number of daunting challenges pushing systems to deal with requirements changes and benefit from modern technologies and telecom capabilities. Systems evolution through extension of the existing information technology infrastructure becomes one of the most challenging aspects of healthcare and the adaptation to changes is a must. The paper presents a change management framework for a citizen-centric healthcare service platform. A combination between Petri nets model to handle changes and reconfigurable Petri nets model to react to these changes are introduced to fulfill healthcare goals. Thanks to this management framework model, consistency and correctness of a healthcare processes in the presence of frequent changes can be checked and guaranteed.

  11. Threat driven modeling framework using petri nets for e-learning system.

    Science.gov (United States)

    Khamparia, Aditya; Pandey, Babita

    2016-01-01

    Vulnerabilities at various levels are main cause of security risks in e-learning system. This paper presents a modified threat driven modeling framework, to identify the threats after risk assessment which requires mitigation and how to mitigate those threats. To model those threat mitigations aspects oriented stochastic petri nets are used. This paper included security metrics based on vulnerabilities present in e-learning system. The Common Vulnerability Scoring System designed to provide a normalized method for rating vulnerabilities which will be used as basis in metric definitions and calculations. A case study has been also proposed which shows the need and feasibility of using aspect oriented stochastic petri net models for threat modeling which improves reliability, consistency and robustness of the e-learning system.

  12. A modeling method of semiconductor fabrication flows with extended knowledge hybrid Petri nets

    Institute of Scientific and Technical Information of China (English)

    Zhou Binghai; Jiang Shuyu; Wang Shijin; Wu bin

    2008-01-01

    A modeling method of extended knowledge hybrid Petri nets (EKHPNs), incorporating object-oriented methods into hybrid Petri nets (HPNs), was presented and used for the representation and modeling of semiconductor wafer fabrication flows. To model the discrete and continuous parts of a complex semiconductor wafer fabrication flow, the HPNs were introduced into the EKHPNs. Object-oriented methods were combined into the EKHPNs for coping with the complexity of the fabrication flow. Knowledge annotations were introduced to solve input and output conflicts of the EKHPNs.Finally, to demonstrate the validity of the EKHPN method, a real semiconductor wafer fabrication case was used to illustrate the modeling procedure. The modeling results indicate that the proposed method can be used to model a complex semiconductor wafer fabrication flow expediently.

  13. Ninth Workshop and Tutorial on Practical Use of Coloured Petri Nets and the CPN Tools

    DEFF Research Database (Denmark)

    to more than 7,200 users in 138 countries. The aim of the workshop is to bring together some of the users and in this way provide a forum for those who are interested in the practical use of Coloured Petri nets and their tools. The submitted papers were evaluated by a programme committee...... have been published in four special sections in the International Journal on Software Tools for Technology Transfer (STTT). For more information see: www.sttt.cs.uni-dortmund.de/. After an additional round of reviewing and revision, some of the papers from this years workshop will be published...... in Transactions of Petri Nets and Other Models of Concurrency (ToPNoC) which is new journal subline of Lecture Notes in Computer Science. For more information see: www.springer.com/lncs/topnoc. Kurt Jensen PC and OC chair...

  14. TAPAAL 2.0: Integrated Development Environment for Timed-Arc Petri Nets

    DEFF Research Database (Denmark)

    David, Alexandre; Jacobsen, Lasse; Jacobsen, Morten

    2012-01-01

    TAPAAL 2.0 is a platform-independent modelling, simula- tion and verification tool for extended timed-arc Petri nets. The tool supports component-based modelling and offers an automated verifica- tion of the EF, AG, EG and AF fragments of TCTL via translations to Uppaal timed automata and via its...... own dedicated verification engine. After more than three years of active development with a main focus on usability aspects and on the efficiency of the verification algorithms, we present the new version of TAPAAL 2.0 that has by now reached its ma- turity and offers the first publicly available tool...... supporting the analysis and verification of timed-arc Petri nets....

  15. Distributed embedded controller development with petri nets application to globally-asynchronous locally-synchronous systems

    CERN Document Server

    Moutinho, Filipe de Carvalho

    2016-01-01

    This book describes a model-based development approach for globally-asynchronous locally-synchronous distributed embedded controllers.  This approach uses Petri nets as modeling formalism to create platform and network independent models supporting the use of design automation tools.  To support this development approach, the Petri nets class in use is extended with time-domains and asynchronous-channels. The authors’ approach uses models not only providing a better understanding of the distributed controller and improving the communication among the stakeholders, but also to be ready to support the entire lifecycle, including the simulation, the verification (using model-checking tools), the implementation (relying on automatic code generators), and the deployment of the distributed controller into specific platforms. Uses a graphical and intuitive modeling formalism supported by design automation tools; Enables verification, ensuring that the distributed controller was correctly specified; Provides flex...

  16. An Efficient Siphon-Based Deadlock Prevention Policy for a Class of Generalized Petri Nets

    Directory of Open Access Journals (Sweden)

    YiFan Hou

    2016-01-01

    Full Text Available We propose a new deadlock prevention policy for an important class of resource allocation systems (RASs that appear in the modeling of flexible manufacturing systems (FMSs. The model of this class in terms of generalized Petri nets is, namely, S4PR. On the basis of recent structural analysis results related to the elementary siphons in generalized Petri nets on one hand and an efficient deadlock avoidance policy proposed for the class of conjunctive/disjunctive (C/D RASs on the other hand, we show how one can generate monitors to be added to a net system such that all its strict minimal siphons are max′-controlled and no insufficiently marked siphon is generated. Thereby, a new, simple, and more permissive liveness-enforcing supervisor synthesis method for S4PR is established.

  17. A Petri Net-Based Software Process Model for Developing Process-Oriented Information Systems

    Science.gov (United States)

    Li, Yu; Oberweis, Andreas

    Aiming at increasing flexibility, efficiency, effectiveness, and transparency of information processing and resource deployment in organizations to ensure customer satisfaction and high quality of products and services, process-oriented information systems (POIS) represent a promising realization form of computerized business information systems. Due to the complexity of POIS, explicit and specialized software process models are required to guide POIS development. In this chapter we characterize POIS with an architecture framework and present a Petri net-based software process model tailored for POIS development with consideration of organizational roles. As integrated parts of the software process model, we also introduce XML nets, a variant of high-level Petri nets as basic methodology for business processes modeling, and an XML net-based software toolset providing comprehensive functionalities for POIS development.

  18. A Case Study on Coloured Petri Nets in Object-oriented Analysis and Design

    DEFF Research Database (Denmark)

    Barros, Joao Paulo; Jørgensen, Jens Bæk

    2005-01-01

    In this paper, we first demonstrate how a coloured Petri nets (CPN) model can be used to capture requirements for a considered example system, an elevator controller. Then, we show how this requirements-level CPN model is transformed into a design-level object-oriented CPN model, which is structu......In this paper, we first demonstrate how a coloured Petri nets (CPN) model can be used to capture requirements for a considered example system, an elevator controller. Then, we show how this requirements-level CPN model is transformed into a design-level object-oriented CPN model, which...... is structurally and conceptually closer to class diagrams and object-oriented programming languages. The CPN models reduce the gap between user-level requirements and the respective implementation, thus simplifying the implementation or code generation. Finally, we discuss the code generation from object-oriented...

  19. Petri Net-Based R&D Process Modeling and Optimization for Composite Materials

    Directory of Open Access Journals (Sweden)

    Xiaomei Hu

    2013-01-01

    Full Text Available Considering the current R&D process for new composite materials involves some complex details, such as formula design, specimen/sample production, materials/sample test, assessment, materials/sample feedback from customers, and mass production, the workflow model of Petri net-based R&D process for new composite materials’ is proposed. By analyzing the time property of the whole Petri net, the optimized model for new composite materials R&D workflow is further proposed. By analyzing the experiment data and application in some materials R&D enterprise, it is demonstrated that the workflow optimization model shortens the period of R&D on new materials for 15%, definitely improving the R&D efficiency. This indicates the feasibility and availability of the model.

  20. XML as a format of expression of Object-Oriented Petri Nets

    Directory of Open Access Journals (Sweden)

    Petr Jedlička

    2004-01-01

    Full Text Available A number of object-oriented (OO variants have so far been devised for Petri Nets (PN. However, none of these variants has ever been described using an open, independent format – such as XML. This article suggests several possibilities and advantages of such a description. The outlined XML language definition for the description of object-oriented Petri Nets (OOPN is based on XMI (description of UML object-oriented models, SOX (simple description of general OO systems and PNML (an XML-based language used for the description of structured and modular PN. For OOPN, the XML form of description represents a standard format for storing as well as for transfer between various OOPN-processing (analysis, simulation, ... tools.

  1. Verification of Concurrent Assembly Programs with a Petri Net Based Safety Policy

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    Concurrent programs written in a machine level language are being used in many areas but verification of such programs brings new challenges to the programming language community. Most of the studies in the literature on verifying the safety properties of concurrent programs are for high-level languages,specifications, or calculi. Therefore, more studies are needed on concurrency verification for machine level language programs. This paper describes a framework of a Petri net based safety policy for the verification of concurrent assembly programs, to exploit the capability of Petri nets in concurrency modeling. The concurrency safety properties can be considered separately using the net structure and by mixing Hoare logic and computational tree logic. Therefore, more useful higher-level safety properties can be specified and verified.

  2. Robust modelling and simulation integration of SIMIO with coloured petri nets

    CERN Document Server

    De La Mota, Idalia Flores; Mujica Mota, Miguel; Angel Piera, Miquel

    2017-01-01

    This book presents for the first time a methodology that combines the power of a modelling formalism such as colored petri nets with the flexibility of a discrete event program such as SIMIO. Industrial practitioners have seen the growth of simulation as a methodology for tacking problems in which variability is the common denominator. Practically all industrial systems, from manufacturing to aviation are considered stochastic systems. Different modelling techniques have been developed as well as mathematical techniques for formalizing the cause-effect relationships in industrial and complex systems. The methodology in this book illustrates how complexity in modelling can be tackled by the use of coloured petri nets, while at the same time the variability present in systems is integrated in a robust fashion. The book can be used as a concise guide for developing robust models, which are able to efficiently simulate the cause-effect relationships present in complex industrial systems without losing the simulat...

  3. Design, Analysis and Optimization of a Solar Dish/Stirling System

    Directory of Open Access Journals (Sweden)

    Seyyed Danial Nazemi

    2016-02-01

    Full Text Available In this paper, a mathematical model by which the thermal and physical behavior of a solar dish/Stirling system was investigated, then the system was designed, analysed and optimized. In this regard, all of heat losses in a dish/Stirling system were calculated, then, the output net-work of the Stirling engine was computed, and accordingly, the system efficiency was worked out. These heat losses include convection and conduction heat losses, radiation heat losses by emission in the cavity receiver, reflection heat losses of solar energy in the parabolic dish, internal and external conduction heat losses, energy dissipation by pressure drops, and energy losses by shuttle effect in displacer piston in the Stirling engine. All of these heat losses in the parabolic dish, cavity receiver and Stirling engine were calculated using mathematical modeling in MatlabTM software. For validation of the proposed model, a 10 kW solar dish/Stirling system was designed and the simulation results were compared with the Eurodish system data with a reasonable degree of agreement. This model is used to investigate the effect of geometric and thermodynamic parameters including the aperture diameter of the parabolic dish and the cavity receiver, and the pressure of the compression space of the Stirling engine, on the system performance. By using the PSO method, which is an intelligent optimization technique, the total design was optimized and the optimal values of decision-making parameters were determined. The optimization has been done in two scenarios. In the first scenario, the optimal value of each designed parameter has been changed when the other parameters are equal to the designed case study parameters. In the second scenario, all of parameters were assumed in their optimal values. By optimization of the modeled dish/Stirling system, the total efficiency of the system improved to 0.60% in the first scenario and it increased from 21.69% to 22.62% in the second

  4. Coloured Petri nets and graphical animation: a proposal for a means to address problem frame concerns

    DEFF Research Database (Denmark)

    Jørgensen, Jens Bæk

    2008-01-01

    specification together entail that the requirements are fulfilled. In this paper, we demonstrate how to address certain frame concerns with the use of the formal modelling language coloured Petri nets (CPN). Problem domain description and machine specification are brought together in a CPN model, which...... is augmented with a graphical animation. The CPN model is executable and we simulate it to address frame concerns. We illustrate the approach on the elevator controller example....

  5. From Task Descriptions via Coloured Petri Nets Towards an Implementation of a New Electronic Patient Record

    DEFF Research Database (Denmark)

    Jørgensen, Jens Bæk; Lassen, Kristian Bisgaard; van der Aalst, Willibrordus Martinus Pancratius

    2008-01-01

    as a basis to construct two executable models in the formal modeling language Colored Petri Nets (CPNs). The first CPN model is used as an execution engine for a graphical animation, which constitutes an Executable Use Case (EUC). The EUC is a prototype-like representation of the task descriptions that can....... We demonstrate how the CWN can be translated into the YAWL workflow language, thus resulting in an operational IT system....

  6. Petri Net Modeling of the Brain Circuit Involved in Aggressive Behavior

    OpenAIRE

    Moreno, Carlos B.; Díaz, José-Luis; Martínez, J. H.

    2015-01-01

    The purpose of this work in to demonstrate the initial results of a research project having as its goal to develop dynamic models of the brain network involved in aggressive behavior. In this way, the complex neural process correlated to basic anger emotions and resulting in aggressive behaviors is purportedly schematized by the use of Petri nets, a work-flow computational tool. Initially, the modeling technique is introduced taking into account the most recent and accepted notion of the neur...

  7. An Approach to Distributed State Space Exploration for Coloured Petri Nets

    DEFF Research Database (Denmark)

    Kristensen, Lars Michael; Petrucci, Laure

    2004-01-01

    We present an approach and associated computer tool support for conducting distributed state space exploration for Coloured Petri Nets (CPNs). The distributed state space exploration is based on the introduction of a coordinating process and a number of worker processes. The worker processes...... Tools. This makes the distributed state space exploration and analysis largely transparent to the analyst. We illustrate the use of the developed tool on an example....

  8. Formalization and Verification of Business Process Modeling Based on UML and Petri Nets

    Institute of Scientific and Technical Information of China (English)

    YAN Zhi-jun; GAN Ren-chu

    2005-01-01

    In order to provide a quantitative analysis and verification method for activity diagrams based business process modeling, a formal definition of activity diagrams is introduced. And the basic requirements for activity diagrams based business process models are proposed. Furthermore, the standardized transformation technique between business process models and basic Petri nets is presented and the analysis method for the soundness and well-structured properties of business processes is introduced.

  9. Design and verification of distributed logic controllers with application of Petri nets

    Energy Technology Data Exchange (ETDEWEB)

    Wiśniewski, Remigiusz; Grobelna, Iwona; Grobelny, Michał; Wiśniewska, Monika [University of Zielona Góra, Licealna 9, 65-417 Zielona Góra (Poland)

    2015-12-31

    The paper deals with the designing and verification of distributed logic controllers. The control system is initially modelled with Petri nets and formally verified against structural and behavioral properties with the application of the temporal logic and model checking technique. After that it is decomposed into separate sequential automata that are working concurrently. Each of them is re-verified and if the validation is successful, the system can be finally implemented.

  10. Stimulation of medical decision expert system by using of time color Petri net method

    Directory of Open Access Journals (Sweden)

    Neda Darvish

    2012-05-01

    Full Text Available The role of management science methods in solving the health problems is a clear potential for improvement. Such an approach in an advanced health care system is achieved for improving the condition of treatment, increasing the efficiency and useful planning of time and human resources. In this study, by using one of the artificial intelligence methods, time color Petri net method, the stimulation of the hospital environment and designing of expert system for optimizing of system, will be done.

  11. FINE-GRAINED DISTRIBUTED MULTIMEDIA SYNCHRONIZA- TION MODEL--ENHANCED FUZZY-TIMING PETRI NET

    Institute of Scientific and Technical Information of China (English)

    韩莹洁; 孙永强; 吴哲辉

    2001-01-01

    A fine-grained distributed multimedia synchronization model--Enhanced Fuzzy timing Petri Net was proposed which is good at modeling indeterminacy and fuzzy. To satisfy the need of maximum tolerable jitter, the sufficient conditions are given in intra-object synchronization. Method to find a proper granularity in inter-object synchronization is also given to satisfy skew. Exceptions are detected and corrected as early as possible using restricted blocking method.

  12. Petri net-based modelling of human-automation conflicts in aviation.

    Science.gov (United States)

    Pizziol, Sergio; Tessier, Catherine; Dehais, Frédéric

    2014-01-01

    Analyses of aviation safety reports reveal that human-machine conflicts induced by poor automation design are remarkable precursors of accidents. A review of different crew-automation conflicting scenarios shows that they have a common denominator: the autopilot behaviour interferes with the pilot's goal regarding the flight guidance via 'hidden' mode transitions. Considering both the human operator and the machine (i.e. the autopilot or the decision functions) as agents, we propose a Petri net model of those conflicting interactions, which allows them to be detected as deadlocks in the Petri net. In order to test our Petri net model, we designed an autoflight system that was formally analysed to detect conflicting situations. We identified three conflicting situations that were integrated in an experimental scenario in a flight simulator with 10 general aviation pilots. The results showed that the conflicts that we had a-priori identified as critical had impacted the pilots' performance. Indeed, the first conflict remained unnoticed by eight participants and led to a potential collision with another aircraft. The second conflict was detected by all the participants but three of them did not manage the situation correctly. The last conflict was also detected by all the participants but provoked typical automation surprise situation as only one declared that he had understood the autopilot behaviour. These behavioural results are discussed in terms of workload and number of fired 'hidden' transitions. Eventually, this study reveals that both formal and experimental approaches are complementary to identify and assess the criticality of human-automation conflicts. Practitioner Summary: We propose a Petri net model of human-automation conflicts. An experiment was conducted with general aviation pilots performing a scenario involving three conflicting situations to test the soundness of our formal approach. This study reveals that both formal and experimental approaches

  13. Opening the stable door: new initiatives at the Petrie Museum of Egyptian Archaeology

    Directory of Open Access Journals (Sweden)

    Sally MacDonald

    2000-11-01

    Full Text Available The Petrie Museum ut UCL contains u world-class collection of Egyptian objects that ranges chronologically from early prehistoric to Islamic times, but it is inadequately housed and remains little known outside Egyptology. It has now been designated us of national importance and its stuff have ambitious plans to provide greater access, via the Internet and in other ways, to the 80000 objects it contains.

  14. Model-Based Testing of a Reactive System with Coloured Petri Nets

    DEFF Research Database (Denmark)

    Tjell, Simon

    2006-01-01

    In this paper, a reactive and nondeterministic system is tested. This is doneby applying a generic model that has been specified as a configurable Coloured PetriNet. In this way, model-based testing is possible for a wide class of reactive system atthe level of discrete events. Concurrently...... executed tasks are specified at a high levelof abstraction and test traces are collected through state space analysis of the model....

  15. Solving the Petri-Nets to Statecharts Transformation Case with FunnyQT

    Directory of Open Access Journals (Sweden)

    Tassilo Horn

    2013-11-01

    Full Text Available FunnyQT is a model querying and model transformation library for the functional Lisp-dialect Clojure providing a rich and efficient querying and transformation API. This paper describes the FunnyQT solution to the TTC 2013 Petri-Nets to Statcharts Transformation Case. This solution has won the best overall solution award and the best efficiency award for this case.

  16. Plastic Surgery Statistics

    Science.gov (United States)

    ... PSN PSEN GRAFT Contact Us News Plastic Surgery Statistics Plastic surgery procedural statistics from the American Society of Plastic Surgeons. Statistics by Year Print 2016 Plastic Surgery Statistics 2015 ...

  17. Fuzzy Stochastic Petri Nets for Modeling Biological Systems with Uncertain Kinetic Parameters.

    Science.gov (United States)

    Liu, Fei; Heiner, Monika; Yang, Ming

    2016-01-01

    Stochastic Petri nets (SPNs) have been widely used to model randomness which is an inherent feature of biological systems. However, for many biological systems, some kinetic parameters may be uncertain due to incomplete, vague or missing kinetic data (often called fuzzy uncertainty), or naturally vary, e.g., between different individuals, experimental conditions, etc. (often called variability), which has prevented a wider application of SPNs that require accurate parameters. Considering the strength of fuzzy sets to deal with uncertain information, we apply a specific type of stochastic Petri nets, fuzzy stochastic Petri nets (FSPNs), to model and analyze biological systems with uncertain kinetic parameters. FSPNs combine SPNs and fuzzy sets, thereby taking into account both randomness and fuzziness of biological systems. For a biological system, SPNs model the randomness, while fuzzy sets model kinetic parameters with fuzzy uncertainty or variability by associating each parameter with a fuzzy number instead of a crisp real value. We introduce a simulation-based analysis method for FSPNs to explore the uncertainties of outputs resulting from the uncertainties associated with input parameters, which works equally well for bounded and unbounded models. We illustrate our approach using a yeast polarization model having an infinite state space, which shows the appropriateness of FSPNs in combination with simulation-based analysis for modeling and analyzing biological systems with uncertain information.

  18. Modular Reversibility Analysis in Self-loops Connections of Petri Net Systems

    Directory of Open Access Journals (Sweden)

    Fei Pu

    2013-02-01

    Full Text Available It is well known that the use of a modular approach for modeling has many advantages: it allows the modeler to consider different parts of the model independently of one another. A modular approach to analysis is also attractive: it often dramatically decreases the complexity of the analysis task. To create Petri net models of large systems, four bottom-up techniques, consisting of sharing operation, synchronous operation, self-loops connection as well as inhibitor-arc connection, have been developed. This paper focus on the concurrent behavior relation in self-loops connections of Petri net systems. First, for the property of dynamic invariance we show that it is possible to decide dynamic invariance of the global system from invariance of the individual modules. Second, for reversibility property we show that it is possible to construct reversibility of total modular system from reversibility of the individual modules without unfolding to the entire state space. Finally, we present some examples to illustrate the effectiveness of our approaches. The advantages of our approaches are in the context of concurrent language and can synthesize Petri net systems beyond asymmetric choice nets.

  19. Plastic bronchitis

    Directory of Open Access Journals (Sweden)

    Anil Kumar Singhi

    2015-01-01

    Full Text Available Plastic bronchitis, a rare but serious clinical condition, commonly seen after Fontan surgeries in children, may be a manifestation of suboptimal adaptation to the cavopulmonary circulation with unfavorable hemodynamics. They are ominous with poor prognosis. Sometimes, infection or airway reactivity may provoke cast bronchitis as a two-step insult on a vulnerable vascular bed. In such instances, aggressive management leads to longer survival. This report of cast bronchitis discusses its current understanding.

  20. Optical analysis and performance evaluation of a solar parabolic dish concentrator

    Directory of Open Access Journals (Sweden)

    Pavlović Saša R.

    2016-01-01

    Full Text Available In this study, the optical design of a solar parabolic dish concentrator is presented. The parabolic dish concentrator consists from 11 curvilinear trapezoidal reflective petals made of polymethyl methacrylate with special reflective coating. The dish diameter is equal to 3.8 m and the theoretical focal point distance is 2.26 m. Numerical simulations are made with the commercial software TracePro from Lambda Research, USA, and the final optimum position between absorber and reflector was calculated to 2.075 m; lower than focus distance. This paper presents results for the optimum position and the optimum diameter of the receiver. The decision for selecting these parameters is based on the calculation of the total flux over the flat and corrugated pipe receiver surface; in its central region and in the peripheral region. The simulation results could be useful reference for designing and optimizing of solar parabolic dish concentrators as for as for CFD analysis, heat transfer and fluid flow analysis in corrugated spiral heat absorbers. [Projekat Ministarstva nauke Republike Srbije, br. III42006: Research and development of energy and environmentally highly effective polygeneration systems based on renewable energy resources i br. III45016: Fabrication and characterization of nanophotonic functional structures in biomedicine and informatics

  1. 9 CFR 381.167 - Other poultry dishes and specialty items.

    Science.gov (United States)

    2010-01-01

    ... 9 Animals and Animal Products 2 2010-01-01 2010-01-01 false Other poultry dishes and specialty..., DEPARTMENT OF AGRICULTURE AGENCY ORGANIZATION AND TERMINOLOGY; MANDATORY MEAT AND POULTRY PRODUCTS INSPECTION AND VOLUNTARY INSPECTION AND CERTIFICATION POULTRY PRODUCTS INSPECTION REGULATIONS Definitions...

  2. A small scale cell culture system to analyze mechanobiology using reporter gene constructs and polyurethane dishes

    DEFF Research Database (Denmark)

    Seefried, Lothar; Mueller-Deubert, Sigrid; Wentzer, Thomas Schwarz

    2010-01-01

    of mechanotransduction and its crosstalk with biochemically induced signal transduction, AP1 and SP1 luciferase reporter gene constructs were cloned and transfected into various cell lines and primary cells. A newly developed bioreactor and small-scale 24-well polyurethane dishes were used to apply cyclic stretching...

  3. THE MICROGARDENING COOKBOOK, DIRECTIONS FOR PREPARING DISHES AND TUBES OF STERILE NUTRIENT AGAR.

    Science.gov (United States)

    CHANDLER, MARION N.

    THIS BOOKLET WAS PREPARED FOR TEACHER USE IN ASSOCIATION WITH THE ELEMENTARY SCIENCE STUDY UNIT "MICROGARDENING." IT CONTAINS DIRECTIONS FOR PREPARING CULTURE DISHES AND TUBES OF NUTRIENT STERILE AGAR FOR FUNGAL AND/OR BACTERIAL GROWTH. IT INCLUDES (1) LISTS OF NEEDED SUPPLIES AND EQUIPMENT, (2) DIRECTIONS FOR THE PREPARATION AND…

  4. THE MICROGARDENING COOKBOOK, DIRECTIONS FOR PREPARING DISHES AND TUBES OF STERILE NUTRIENT AGAR.

    Science.gov (United States)

    CHANDLER, MARION N.

    THIS BOOKLET WAS PREPARED FOR TEACHER USE IN ASSOCIATION WITH THE ELEMENTARY SCIENCE STUDY UNIT "MICROGARDENING." IT CONTAINS DIRECTIONS FOR PREPARING CULTURE DISHES AND TUBES OF NUTRIENT STERILE AGAR FOR FUNGAL AND/OR BACTERIAL GROWTH. IT INCLUDES (1) LISTS OF NEEDED SUPPLIES AND EQUIPMENT, (2) DIRECTIONS FOR THE PREPARATION AND…

  5. Modelling dishes and exploring culinary 'precisions': the two issues of molecular gastronomy.

    Science.gov (United States)

    This, Hervé

    2005-04-01

    The scientific strategy of molecular gastronomy includes modelling 'culinary definitions' and experimental explorations of 'culinary precisions'. A formalism that describes complex dispersed systems leads to a physical classification of classical sauces, as well as to the invention of an infinite number of new dishes.

  6. Mobile Satellite Reception with a Virtual Satellite Dish based on a Reconfigurable Multi-Processor Architecture

    NARCIS (Netherlands)

    Burgwal, van de M.D.; Rovers, K.C.; Blom, K.C.H.; Kokkeler, A.B.J.; Smit, G.J.M.

    2011-01-01

    Traditionally, mechanically steered dishes or analog phased array beamforming systems have been used for radio frequency receivers, where strong directivity and high performance were much more important than low-cost requirements. Real-time controlled digital phased array beamforming could not be re

  7. Membrane dish analysis: A summary of structural and optical analysis capabilities

    Energy Technology Data Exchange (ETDEWEB)

    Steele, C.R.; Balch, C.D.; Jorgensen, G.J.; Wendelin, T.; Lewandowski, A.

    1991-11-01

    Research at SERI within the Department of Energy's Solar Thermal Technology Program has focused on the development of membrane dish concentrators for space and terrestrial power applications. As potentially lightweight, inexpensive, high-performance structures, they are excellent candidates for space-deployable energy sources as well as cost-effective terrestrial energy concepts. A thorough engineering research treatment of these types of structures consists primarily of two parts: (1) structural mechanics of the membrane and ring support and (2) analysis and characterization of the concentrator optical performance. It is important to understand the effects of the membrane's structure and support system on the optical performance of the concentrator. This requires an interface between appropriate structural and optical models. Until recently, such models and the required interface have not existed. This report documents research that has been conducted at SERI in this area. It is a compilation of several papers describing structural models of membrane dish structures and optical models used to predict dish concentrator optical and thermal performance. The structural models were developed under SERI subcontract by Dr. Steele and Dr. Balch of Stanford University. The optical model was developed in-house by SERI staff. In addition, the interface between the models is described. It allows easy and thorough characterization of membrane dish systems from the mechanics to the resulting optical performance. The models described herein have been and continue to be extremely useful to SERI, industry, and universities involved with the modeling and analysis of lightweight membrane concentrators for solar thermal applications.

  8. Slope Measurements of Parabolic Dish Concentrators Using Color-Coded Targets

    Energy Technology Data Exchange (ETDEWEB)

    Ulmer, S.; Heller, P.; Reinalter, W.

    2006-07-01

    A new short, yet highly accurate method for measuring the slope errors of parabolic dish concentrators has been developed. This method uses a flat target with colored stripes that is placed close to the focal plane and a digital camera located at an observation point on the optical axis at some distance from it. A specially developed image analysis algorithm detects the different colors in the images of the reflection of the target in the concentrator and assigns them their known position on the color target. This information, along with the geometric relationship between the components of the measurement setup and the theoretical parabolic shape of the concentrator, is used to calculate the normal vectors of the concentrator surface. From these normal vectors the radial and tangential slopes can be calculated and compared to the design values of the concentrator. The resulting slope errors not only give the total concentrator error for general characterization of the dish, but also indicate systematic errors in fabrication and mounting with high spatial resolution. In order to verify the quality of the results obtained, a ray-tracing code was developed that calculates the flux distribution on planes perpendicular to the optical axis. Measured slope errors of a DISTAL-2 dish concentrator are presented and the calculated flux distributions are compared to measured flux distributions. The comparison shows excellent agreement in the flux distribution on the absorber plane. This verifies the promising potential of this method for fast, highly precise measurement of imperfections in dish concentrator shape. (Author)

  9. Nutritional assessment of the most frequently consumed dishes in a slum in Iquitos, Peruvian Amazon

    Directory of Open Access Journals (Sweden)

    Guillermo Molina Recio

    Full Text Available Introduction: Large nutritional surveys in Peru have identified the magnitude and location of the different types of malnutrition. The chronic type is the most prevalent one. However, although rates may be considered as alarming (even more in rural areas, only one of these studies contains information about intake characteristics, using 24-hour recalls (R24. That is, it lacks some other systems, adapted to the gastronomical characteristics of their regions and to the bioavailability of food in each area, in order to locate the origin of this situation and, thus, propose truly effective and efficient solutions. Aim: To determine the nutritional value of the main dishes consumed by the residents of a slum in Peruvian Amazon. Methods: Ninety-eight participants completed three 24-h recalls. Based on these data, we selected the 25 most commonly eaten dishes and evaluated their nutritional composition. We took note of the homemade recipes, weights and measures. In addition, we observed preparation and cooking. The mean nutritional composition of each dish was calculated per 100 g using the Nutriplato 4.6. software. We also calculated gains or losses resulting from culinary treatments. Results: Within those which include milk, the highest energy density is the mingado de arroz. In the group of fish, the most energetic is pescado frito, while within meat-based recipes tallarín con pollo, res asada and chancho frito are the most energetic ones. Regarding prepared dishes, the juane is the highest energy density of all recipes. Inside garnish, using bananas as the main ingredient, plátano frito and madurito are the most energetic. Fats are higher in fried dishes and those which contribute most fat ratio. The same thing happens with garnish as 100 grams of plátano frito or madurito contain more than 70% of the RDA. Res asada and juane present the highest sodium level. Conclusions: If we wish to offer healthier dishes, it is necessary to change their

  10. 自主式追踪机器人终端行为的 Petri 网建模%Terminal behavior modeling for autonomous tracking robots using Petri nets

    Institute of Scientific and Technical Information of China (English)

    孔庆艳; 袁杰; 郭俊辉

    2016-01-01

    针对含有资源流动和信息交互的终端行为建模问题,提出了一种混合Petri网行为建模方法。引入活性变迁和惰性变迁两种变迁模式,描述终端行为的耦合、制约、异步关系。建立混合Petri网模型,揭示化学羽流追踪终端各行为之间的交互关系,以Robotics模块为验证与分析工具,仿真机器人终端运动过程,同时获得六个关节角度变化的平稳曲线。最后,在六自由度串联机器人平台加以验证。实验结果表明,该混合Petri网模型客观真实地表达对象内部逻辑关系与交互作用机制,对自主式羽流追踪机器人终端行为建模是有效可行的。%Focused on the issue that the terminal behavior modeling contains resource flowing and information interaction,this paper proposed a behavior modeling method of hybrid Petri net.Firstly,it introduced the active transitions and inertia transi-tions and described the coupling,restriction,and asynchronous relationships among behaviors.Secondly,the hybrid Petri net model showed the interactions among the various terminal behaviors during a chemical plume tracking process.It used a Robo-tics module as the verification and analysis tools for simulating the robot terminal movements,and obtained the smooth curves of six joints angle changes.Finally,it verified the method in a 6-DOF industrial robot platform.The results show that the hy-brid Petri nets model can truly express the internal logical relationships and the interaction mechanisms of objects.Terminal behavior models are effective and feasible for autonomous robots to track plumes.

  11. Design and Fabrication of a Two Axis Parabolic Solar Dish Collector

    Directory of Open Access Journals (Sweden)

    Prof. Sonal C Yogi

    2014-11-01

    Full Text Available The work consists of the design of the chain drive system and the fabrication of the two axis parabolic solar dish. It is a model study of the two axis parabolic dish which worked by the automatic circuit that was developed. Ready made parabolic solar dish is taken and fabricated. The circular iron ring provides the two axis motion of the dish. A compound chain drive system was developed for the smooth movement of the dish. An electromechanical system which tracks the sun on both axes and which is controlled via a programmable logic control (PLC was designed and implemented. In this a theoretical study was done. A C program was made which gave the required result for the graphical representation of the recorded radiation. Programmable Logic Controls (PLC was used instead of photo sensors, which are widely used for tracking the sun. The azimuthal angle of the sun from sunrise to sunset times was calculated for each day of the year at 23.59 Lat & 72.38Longitude in the Northern hemisphere, the location of the city Mehsana. According to this azimuth angle, the required analog signal was taken from the PLC analog module and sent to the power window motor, which controlled the position of the panel to ensure that the rays fall vertically on the panel. After the mechanical control of the system was started, the performance measurements of the solar panel were carried out. The values obtained from the measurements were compared and the necessary evaluations were conducted.

  12. 基于D-Petri Net和动态调度的网格工作流%Grid Workflow Based on D-Petri Net and Dynamic Scheduling

    Institute of Scientific and Technical Information of China (English)

    张绍华; 顾宁; 刘家茂; 施伯乐

    2005-01-01

    提出了网格工作流体系结构;给出了基于D-Petri Net的网格工作流建模语言和验证方法,利用该建模语言生成的过程模型适合网格资源动态性的特点;分析了根据网格性能动态产生并行任务和动态调度的算法;最后介绍了在Globus上实现的原型系统和在基因测序中的应用.该系统具有良好的效果.

  13. Método para el Modelado y Prueba de Diagramas de Actividades Mediante Redes de Petri

    Directory of Open Access Journals (Sweden)

    Lionel Baquero Hernández

    2015-11-01

    Full Text Available Las redes de Petri son ideales para describir y estudiar sistemas que procesan información y con características concurrentes, asíncronas, distribuidas, paralelas, no determinísticas y/o estocásticas. . Sin embargo, la teoría clásica de estas redes se enfrenta al desafío de adecuarse a las nuevas necesidades de los sistemas informáticos que los ingenieros diseñan en la actualidad. Un diagrama de actividades representa una secuencia de actividades. Podría aplicarse a cualquier propósito, pero se considera especialmente útil para visualizar los flujos de trabajo y los procesos del negocio, o casos de uso. El presente trabajo se ha desarrollado con el objetivo de diseñar un método para el modelado y prueba de diagramas de actividades mediante redes de Petri. El método propuesto brinda una serie de pasos necesarios para modelar un diagrama de actividades con redes de Petri y a partir de dicha red obtener una representación matemática de la misma. Esta representación matemática se utiliza para con ella realizar una serie de operaciones basadas en el marcaje de la red que permiten realizar pruebas al diagrama. Este método es capaz de identificar errores comunes que se cometen en el modelado de los diagramas de actividades, lo cual se demostró a través del método de experimentación.

  14. Fuzzy-Neural Petri Net Distributed Control System Using Hybrid Wireless Sensor Network and CAN Fieldbus

    Directory of Open Access Journals (Sweden)

    Ali A. Abed

    2016-06-01

    Full Text Available The reluctance of industry to allow wireless paths to be incorporated in process control loops has limited the potential applications and benefits of wireless systems. The challenge is to maintain the performance of a control loop, which is degraded by slow data rates and delays in a wireless path. To overcome these challenges, this paper presents an application–level design for a wireless sensor/actuator network (WSAN based on the “automated architecture”. The resulting WSAN system is used in the developing of a wireless distributed control system (WDCS. The implementation of our wireless system involves the building of a wireless sensor network (WSN for data acquisition and controller area network (CAN protocol fieldbus system for plant actuation. The sensor/actuator system is controlled by an intelligent digital control algorithm that involves a controller developed with velocity PID-like Fuzzy Neural Petri Net (FNPN system. This control system satisfies two important real-time requirements: bumpless transfer and anti-windup, which are needed when manual/auto operating aspect is adopted in the system. The intelligent controller is learned by a learning algorithm based on back-propagation. The concept of petri net is used in the development of FNN to get a correlation between the error at the input of the controller and the number of rules of the fuzzy-neural controller leading to a reduction in the number of active rules. The resultant controller is called robust fuzzy neural petri net (RFNPN controller which is created as a software model developed with MATLAB. The developed concepts were evaluated through simulations as well validated by real-time experiments that used a plant system with a water bath to satisfy a temperature control. The effect of disturbance is also studied to prove the system's robustness.

  15. Modelling M/G/1 queueing systems with server vacations using stochastic Petri nets

    Directory of Open Access Journals (Sweden)

    K Ramanath

    2006-12-01

    Full Text Available The theory of non-Markovian stochastic Petri nets is employed in this paper to derive an alternative method for studying the steady state behaviour of the M/G/1 vacation queueing system with a limited service discipline. Three types of vacation schemes are considered, and sytems with both a finite population and those with an infinite population (but finite capacity are considered. Simple numerical examples are also provided to illustrate the functionality of the methods and some useful performance measures for the system are obtained.

  16. Requirements Engineering for Reactive Systems: Coloured Petri Nets for an Elevator Controller

    DEFF Research Database (Denmark)

    Jørgensen, Jens Bæk; Fernandes, Joao Miguel; Tjell, Simon

    2007-01-01

    This paper presents a model-based approach to requirements engineering for reactive systems; we use an elevator controller as case study. We identify and justify two key properties that a model which we construct must have, namely: (1) controller-and-environment-partitioned, which means...... descriptions. For the case study, we build an executable model in the formal modelling language Coloured Petri Nets. We demonstrate how this model is useful for requirements engineering, since it provides a solid basis for addressing behavioural issues early in the development process, for example regarding...

  17. From Task Descriptions via Coloured Petri Nets Towards an Implementation of a New Electronic Patient Record

    DEFF Research Database (Denmark)

    Jørgensen, Jens Bæk; Lassen, Kristian Bisgaard; van der Aalst, Willibrordus Martinus Pancratius

    2008-01-01

    as a basis to construct two executable models in the formal modeling language Colored Petri Nets (CPNs). The first CPN model is used as an execution engine for a graphical animation, which constitutes an Executable Use Case (EUC). The EUC is a prototype-like representation of the task descriptions that can...... help to validate and elicit requirements. The second CPN model is a Colored Workflow Net (CWN). The CWN is derived from the EUC. Together, the EUC and the CWN are used to close the gap between the given requirements specification and the realization of these requirements with the help of an IT system...

  18. A Formal Model of OSI X.25/FR Gateway Based on High Level Petri Net

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    Specification and validation of protocol conversion in a gatewayis a difficult problem in protocol engineering. During design and implementation of an OSI X.25/FR gateway, a high-level Petri Net called EPr/TN is introduced as a formal specification tool to solve this problem. A formal model of the gateway is constructed by using Epr/TN. Based on this model, the process of protocol conversion and data transmission in the gateway are analyzed and validated. With object-oriented techniques, this model is also utilized in the software development of the gateway.

  19. A Method for Modeling the Virtual Instrument Automatic Test System Based on the Petri Net

    Institute of Scientific and Technical Information of China (English)

    MA Min; CHEN Guang-ju

    2005-01-01

    Virtual instrument is playing the important role in automatic test system. This paper introduces a composition of a virtual instrument automatic test system and takes the VXIbus based a test software platform which is developed by CAT lab of the UESTC as an example. Then a method to model this system based on Petri net is proposed. Through this method, we can analyze the test task scheduling to prevent the deadlock or resources conflict. At last, this paper analyzes the feasibility of this method.

  20. Integrated logistic support studies using behavioral Monte Carlo simulation, supported by Generalized Stochastic Petri Nets

    Energy Technology Data Exchange (ETDEWEB)

    Garnier, Robert; Chevalier, Marcel [Schneider Electric (France)

    2000-07-01

    Studying large and complex industrial sites, requires more and more accuracy in modeling. In particular, when considering Spares, Maintenance and Repair / Replacement processes, determining optimal Integrated Logistic Support policies requires a high level modeling formalism, in order to make the model as close as possible to the real considered processes. Generally, numerical methods are used to process this kind of study. In this paper, we propose an alternate way to process optimal Integrated Logistic Support policy determination when dealing with large, complex and distributed multi-policies industrial sites. This method is based on the use of behavioral Monte Carlo simulation, supported by Generalized Stochastic Petri Nets. (author)

  1. Performance Estimation for Hardware/Software codesign using Hierarchical Colored Petri Nets

    DEFF Research Database (Denmark)

    Grode, Jesper Nicolai Riis; Madsen, Jan; Jerraya, Ahmed

    1998-01-01

    estimation tool. This makes the approach very useful for designing component models used for performance estimation in Hardware/Software Codesign frameworks such as the LYCOS system. The paper presents the methodology and rules for designing component models using HCPNs. Two examples of architectural models......This paper presents an approach for abstract modeling of the functional behavior of hardware architectures using Hierarchical Colored Petri Nets (HCPNs). Using HCPNs as architectural models has several advantages such as higher estimation accuracy, higher flexibility, and the need for only one...

  2. Model-Based Requirements Analysis for Reactive Systems with UML Sequence Diagrams and Coloured Petri Nets

    DEFF Research Database (Denmark)

    Tjell, Simon; Lassen, Kristian Bisgaard

    2008-01-01

    In this paper, we describe a formal foundation for a specialized approach to automatically checking traces against real-time requirements. The traces are obtained from simulation of Coloured Petri Net (CPN) models of reactive systems. The real-time requirements are expressed in terms...... of a derivative of UML 2.0 high-level Sequence Diagrams. The automated requirement checking is part of a bigger tool framework in which VDM++ is applied to automatically generate initial CPN models based on Problem Diagrams. These models are manually enhanced to provide behavioral descriptions of the environment...

  3. Serial Failure Diagnosis of a Transmission Line Protection Relaying System by Petri Nets

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    With the development of large-scale complicated modern power systems, the requirement for the associatedprotection scheme tends to be more stringent and its combination more complex. However, it is very difficult to figureout the factors of failure of such systems. This paper proposes a Petri net model of a transmission line protectionrelaying system, including three types of relays as well as an automatic re-closing device, and shows how to diagnoseserial failure of the system by analyzing invariant sets of the model. Furthermore, it gives four basic types of failuresequences and its execution is much more intuitive and effective than the traditional method.

  4. Method of Dynamic Knowledge Representation and Learning Based on Fuzzy Petri Nets

    Institute of Scientific and Technical Information of China (English)

    WEI Sheng-jun; HU Chang-zhen; SUN Ming-qian

    2008-01-01

    A method of knowledge representation and learning based on fuzzy Petri nets was designed. In this way the parameters of weights, threshold value and certainty factor in knowledge model can be adjusted dynamically. The advantages of knowledge representation based on production rules and neural networks were integrated into this method. Just as production knowledge representation, this method has clear structure and specific parameters meaning. In addition, it has learning and parallel reasoning ability as neural networks knowledge representation does. The result of simulation shows that the learning algorithm can converge, and the parameters of weights, threshold value and certainty factor can reach the ideal level after training.

  5. Solving Resource-constrained Multiple Project Scheduling Problem Using Timed Colored Petri Nets

    Institute of Scientific and Technical Information of China (English)

    WU Yu; ZHUANG Xin-cun; SONG Guo-hui; XU Xiao-dong; LI Cong-xin

    2009-01-01

    To solve the resource-constrained multiple project scheduling problem (RCMPSP) more effectively, a method based on timed colored Petri net (TCPN) was proposed. In this methodology, firstly a novel mapping mechanism between traditional network diagram such as CPM (critical path method)/PERT (program evaluation and review technique) and TCPN was presented. Then a primary TCPN (PTCPN) for solving RCMPSP was modeled based on the proposed mapping mechanism. Meanwhile, the object PTCPN was used to simulate the multiple projects scheduling and to find the approximately optimal value of RCMPSP. Finally, the performance of the proposed approach for solving RCMPSP was validated by executing a mould manufacturing example.

  6. TCTL-Preserving Translations from Timed-Arc Petri Nets to Networks of Timed Automata

    DEFF Research Database (Denmark)

    Byg, Joakim; Jacobsen, Morten; Jacobsen, Lasse;

    2014-01-01

    We present a framework for TCTL-preserving translations between time-dependent modeling formalisms. The framework guarantees that once the original and the translated system are in one-by-many correspondence relation (a notion of behavioral equivalence between timed transition systems) then TCTL...... properties of the original system can be transformed too while preserving the verification answers. We demonstrate the usability of the technique on two reductions from bounded timed-arc Petri nets to networks for timed automata, providing unified proofs of the translations implemented in the verification...

  7. Overcoming maladaptive plasticity through plastic compensation

    Directory of Open Access Journals (Sweden)

    Matthew R.J. MORRIS, Sean M. ROGERS

    2013-08-01

    Full Text Available Most species evolve within fluctuating environments, and have developed adaptations to meet the challenges posed by environmental heterogeneity. One such adaptation is phenotypic plasticity, or the ability of a single genotype to produce multiple environmentally-induced phenotypes. Yet, not all plasticity is adaptive. Despite the renewed interest in adaptive phenotypic plasticity and its consequences for evolution, much less is known about maladaptive plasticity. However, maladaptive plasticity is likely an important driver of phenotypic similarity among populations living in different environments. This paper traces four strategies for overcoming maladaptive plasticity that result in phenotypic similarity, two of which involve genetic changes (standing genetic variation, genetic compensation and two of which do not (standing epigenetic variation, plastic compensation. Plastic compensation is defined as adaptive plasticity overcoming maladaptive plasticity. In particular, plastic compensation may increase the likelihood of genetic compensation by facilitating population persistence. We provide key terms to disentangle these aspects of phenotypic plasticity and introduce examples to reinforce the potential importance of plastic compensation for understanding evolutionary change [Current Zoology 59 (4: 526–536, 2013].

  8. Overcoming maladaptive plasticity through plastic compensation

    Institute of Scientific and Technical Information of China (English)

    Matthew R.J.MORRIS; Sean M.ROGERS

    2013-01-01

    Most species evolve within fluctuating environments,and have developed adaptations to meet the challenges posed by environmental heterogeneity.One such adaptation is phenotypic plasticity,or the ability of a single genotype to produce multiple environmentally-induced phenotypes.Yet,not all plasticity is adaptive.Despite the renewed interest in adaptive phenotypic plasticity and its consequences for evolution,much less is known about maladaptive plasticity.However,maladaptive plasticity is likely an important driver of phenotypic similarity among populations living in different environments.This paper traces four strategies for overcoming maladaptive plasticity that result in phenotypic similarity,two of which involve genetic changes (standing genetic variation,genetic compensation) and two of which do not (standing epigenetic variation,plastic compensation).Plastic compensation is defined as adaptive plasticity overcoming maladaptive plasticity.In particular,plastic compensation may increase the likelihood of genetic compensation by facilitating population persistence.We provide key terms to disentangle these aspects of phenotypic plasticity and introduce examples to reinforce the potential importance of plastic compensation for understanding evolutionary change.

  9. Cultivation-independent comprehensive investigations on bacterial communities in serofluid dish, a traditional Chinese fermented food.

    Science.gov (United States)

    Chen, Peng; Wu, Zhengrong; Zhao, Yang; Wei, Yan; Xu, Ruixiang; Yan, Lei; Li, Hongyu

    2016-03-01

    Serofluid dish (or Jiangshui, in Chinese), a traditional food in the Chinese culture, is made from vegetables by fermentation. In this study, bacterial community of the fermented serofluid dish was assessed by Illumina amplicon sequencing. The metagenome comprised of 49,589 average raw reads with an average 11,497,917 bp and G + C content is 52.46%. This is the first report on V4 hyper-variable region of the 16S rRNA metagenome sequence employing Illumina platform to profile the microbial community of this little known fermented food from Gansu Province, China. The metagenome sequence can be accessed at NCBI, SRA database accession no. SRP065370.

  10. Cultivation-independent comprehensive investigations on bacterial communities in serofluid dish, a traditional Chinese fermented food

    Directory of Open Access Journals (Sweden)

    Peng Chen

    2016-03-01

    Full Text Available Serofluid dish (or Jiangshui, in Chinese, a traditional food in the Chinese culture, is made from vegetables by fermentation. In this study, bacterial community of the fermented serofluid dish was assessed by Illumina amplicon sequencing. The metagenome comprised of 49,589 average raw reads with an average 11,497,917 bp and G+C content is 52.46%. This is the first report on V4 hyper-variable region of the 16S rRNA metagenome sequence employing Illumina platform to profile the microbial community of this little known fermented food from Gansu Province, China. The metagenome sequence can be accessed at NCBI, SRA database accession no. SRP065370.

  11. Acrylamide in a fried potato dish (rösti) from restaurants in Zurich, Switzerland.

    Science.gov (United States)

    McCombie, Gregor; Biedermann, Maurus; Biedermann-Brem, Sandra; Suter, Gaby; Eicher, Angela; Pfefferle, Anton

    2016-01-01

    Rösti, a fried potato product, is a large contributor to acrylamide exposure locally in Switzerland. A survey of 55 dishes prepared by 51 restaurants in the city of Zurich showed that the average rösti contained 702 µg/kg acrylamide. By analysing the content of reducing sugars in the potatoes used for frying, it is shown that with simple measures, the exposure to acrylamide could easily be reduced by factor 2 or more, while even improving the culinary experience. Though rösti is a typical dish in the German-speaking areas in Switzerland, the result may be of general interest for fried potato products which are popular in large areas of Central Europe.

  12. Dish washing detergent market%中国洗洁精市场概况

    Institute of Scientific and Technical Information of China (English)

    谷俊

    2011-01-01

    this paper points out the phenomenon of concentration highly and homogeneity seriously in dish washing detergent market,analyzes factors in the main sale channels,approach as well as influence for consumers purchase.Finally,it introduces the strategy in dish washing detergent market.%探讨了洗洁精市场集中度高和同质化严重的现象。分析了主要销售渠道、销售手段以及影响消费者购买洗洁精的因素。最后,介绍了洗洁精行业的市场竞争战略。

  13. Optical design and optimization of parabolic dish solar concentrator with a cavity hybrid receiver

    Science.gov (United States)

    Blázquez, R.; Carballo, J.; Silva, M.

    2016-05-01

    One of the main goals of the BIOSTIRLING-4SKA project, funded by the European Commission, is the development of a hybrid Dish-Stirling system based on a hybrid solar-gas receiver, which has been designed by the Swedish company Cleanergy. A ray tracing study, which is part of the design of this parabolic dish system, is presented in this paper. The study pursues the optimization of the concentrator and receiver cavity geometry according to the requirements of flux distribution on the receiver walls set by the designer of the hybrid receiver. The ray-tracing analysis has been performed with the open source software Tonatiuh, a ray-tracing tool specifically oriented to the modeling of solar concentrators.

  14. Membrane dish analysis: A summary of structural and optical analysis capabilities

    Energy Technology Data Exchange (ETDEWEB)

    Steele, C.R.; Balch, C.D.; Jorgensen, G.J.; Wendelin, T.; Lewandowski, A.

    1991-11-01

    Research at SERI within the Department of Energy`s Solar Thermal Technology Program has focused on the development of membrane dish concentrators for space and terrestrial power applications. As potentially lightweight, inexpensive, high-performance structures, they are excellent candidates for space-deployable energy sources as well as cost-effective terrestrial energy concepts. A thorough engineering research treatment of these types of structures consists primarily of two parts: (1) structural mechanics of the membrane and ring support and (2) analysis and characterization of the concentrator optical performance. It is important to understand the effects of the membrane`s structure and support system on the optical performance of the concentrator. This requires an interface between appropriate structural and optical models. Until recently, such models and the required interface have not existed. This report documents research that has been conducted at SERI in this area. It is a compilation of several papers describing structural models of membrane dish structures and optical models used to predict dish concentrator optical and thermal performance. The structural models were developed under SERI subcontract by Dr. Steele and Dr. Balch of Stanford University. The optical model was developed in-house by SERI staff. In addition, the interface between the models is described. It allows easy and thorough characterization of membrane dish systems from the mechanics to the resulting optical performance. The models described herein have been and continue to be extremely useful to SERI, industry, and universities involved with the modeling and analysis of lightweight membrane concentrators for solar thermal applications.

  15. Modeling the small-scale dish-mounted solar thermal Brayton cycle

    Science.gov (United States)

    Le Roux, Willem G.; Meyer, Josua P.

    2016-05-01

    The small-scale dish-mounted solar thermal Brayton cycle (STBC) makes use of a sun-tracking dish reflector, solar receiver, recuperator and micro-turbine to generate power in the range of 1-20 kW. The modeling of such a system, using a turbocharger as micro-turbine, is required so that optimisation and further development of an experimental setup can be done. As a validation, an analytical model of the small-scale STBC in Matlab, where the net power output is determined from an exergy analysis, is compared with Flownex, an integrated systems CFD code. A 4.8 m diameter parabolic dish with open-cavity tubular receiver and plate-type counterflow recuperator is considered, based on previous work. A dish optical error of 10 mrad, a tracking error of 1° and a receiver aperture area of 0.25 m × 0.25 m are considered. Since the recuperator operates at a very high average temperature, the recuperator is modeled using an updated ɛ-NTU method which takes heat loss to the environment into consideration. Compressor and turbine maps from standard off-the-shelf Garrett turbochargers are used. The results show that for the calculation of the steady-state temperatures and pressures, there is good comparison between the Matlab and Flownex results (within 8%) except for the recuperator outlet temperature, which is due to the use of different ɛ-NTU methods. With the use of Matlab and Flownex, it is shown that the small-scale open STBC with an existing off-the-shelf turbocharger could generate a positive net power output with solar-to-mechanical efficiency of up to 12%, with much room for improvement.

  16. AIPS++ and the GBT: a layered approach to processing and analysis of single-dish data

    Science.gov (United States)

    Braatz, James; McMullin, Joseph; Garwood, Robert; Kemball, Athol

    2002-12-01

    The Green Bank Telescope (GBT) is a new 100-m diameter antenna with an unblocked aperture and an active surface. It is designed to observe at frequencies from 300 MHz to 100 GHz, and includes state of the art continuum and spectral backends. The GBT is also capable of pulsar work and recording as a VLB station, and array receivers are being developed as well. AIPS++ is the integral software package for analysis of GBT data both for scientific analysis as well as for control and engineering analysis of the component systems. In this paper we will give an overview of how the AIPS++ system is used with the GBT, with special consideration to the development of spectral analysis software. AIPS++ allows a layered approach to software development, and the spectral analysis capability gives a strong example of the usefulness of the layered approach. At the heart of AIPS++ is a suite of tools which are capable of astronomy-specific calculations as well as general purpose mathematical analysis, data visualization, GUI development, and scripting. A tool for analyzing single-dish data, DISH, is developed on this platform. DISH includes a number of modern features such as bulk processing of datasets and versatile GUI interaction. A simplified package using a familiar CLI, known as UNI-jr, is built on DISH and is available as an easy to learn path for processing scan-based data. Finally, the Interim Automated Reduction and Display System (IARDS) is built on UNI-jr and provides an automated reduction package and pseudo real-time display.

  17. A Survey of Reachability Trees of Unbounded Petri Nets%无界Petri网的可达树的综述

    Institute of Scientific and Technical Information of China (English)

    干梦迪; 王寿光; 周孟初; 李俊; 李月

    2015-01-01

    Petri 网自提出以来得到了学术界和工业界的广泛关注。 Petri 网系统的可达性是最基本性质之一。系统的其他相关性质都可以通过可达性进行分析。利用等价的有限可达树来研究无界Petri 网可达性,依然是一个开放性问题。该研究可以追溯到40年前,但由于问题本身的复杂性和难度太大,直到最近20年,经过国内外诸多学者的不懈努力,才逐渐取得了一些阶段性的成果和部分突破。本文回顾了近40年来国内外学者为彻底解决该问题作出的贡献。重点对4种开创性的研究成果展开讨论,分别为有限可达树、扩展可达树、改进可达树及新型改进可达树。探讨了今后无界Petri网可达性问题的研究方向。%In recent years both industry and academia have paid much attention to the theory and applications of Petri nets. Reachability is a basic property of a Petri net, and many properties can be analyzed via it. However, analyzing the reachability problem of unbounded Petri nets by finite reachability trees has been an open problem since the inception of Petri nets. Researchers began to study the problem of reachability trees over 40 years ago. However, they made only limited progress over the last 20 years due to its complexity and difficulty. We present an overview of some important contributions toward its solution. The focuses are on four novel finite reachability trees: finite reachability tree (FRT), augmented reachability tree (ART), modified reachability tree (MRT) and new modified reachailbity tree (NMRT). The paper concludes with a discussion of directions for future research of the reachability problem of unbounded Petri nets.

  18. Pork in good company? Exploratory analysis of side dishes, beverages, foodscapes and individual characteristics.

    Science.gov (United States)

    Verbeke, Wim; Perez-Cueto, Federico J A; de Barcellos, Marcia Dutra; Grunert, Klaus G

    2013-11-01

    The objective of this study is to explore the association between pork as the main meal component and the choice for side dishes and beverages depending on foodscape and individual characteristics, including overweight and obesity among fresh pork consumers (n=2156) in five European countries (Belgium, Denmark, Germany, Greece and Poland). Males were found to combine pork more with caloric drinking (odds ratio=1.32) and low levels of vegetable intake (odds ratio=1.32) compared to females. Younger consumers were more likely to combine pork with low levels of vegetable intake but less likely to combine pork with sauces or condiments. Heavy users of pork were more likely (odds ratio=1.43) to combine pork with sauces or condiments. The study also found an association between being overweight or obese and higher consumption of carbohydrate rich staple foods (odds ratio=1.30) and caloric drinks (odds ratio=1.30) as side dishes to pork meat. Substantial cross-cultural differences were revealed in line with typical pork consumption and meal composition habits in the respective countries. Finally, this study found that the company of family plays a significant role when choosing side dishes for pork as meal center, thus constituting a relevant venue for the positioning and marketing of pork, as well as for future public health information about meals with pork as main meal component.

  19. Primary Beam and Dish Surface Characterization at the Allen Telescope Array by Radio Holography

    CERN Document Server

    Atkinson, Shannon; Backus, P R; Barott, William; Bauermeister, Amber; Blitz, Leo; Bock, D C -J; Bower, Geoffrey C; Bradford, Tucker; Cheng, Calvin; Croft, Steve; Dexter, Matt; Dreher, John; Engargiola, Greg; Fields, Ed; Heiles, Carl; Helfer, Tamara; Jordan, Jane; Jorgensen, Susan; Kilsdonk, Tom; Gutierrez-Kraybill, Colby; Keating, Garrett; Law, Casey; Lugten, John; MacMahon, D H E; McMahon, Peter; Milgrome, Oren; Siemion, Andrew; Smolek, Ken; Thornton, Douglas; Pierson, Tom; Randall, Karen; Ross, John; Shostak, Seth; Tarter, J C; Urry, Lynn; Werthimer, Dan; Williams, Peter K G; Whysong, David; Harp, G R; Ackermann, R F; Nadler, Z J; Blair, Samantha K; Davis, M M; Wright, M C H; Forster, J R; DeBoer, D R; Welch, W J

    2012-01-01

    The Allen Telescope Array (ATA) is a cm-wave interferometer in California, comprising 42 antenna elements with 6-m diameter dishes. We characterize the antenna optical accuracy using two-antenna interferometry and radio holography. The distortion of each telescope relative to the average is small, with RMS differences of 1 percent of beam peak value. Holography provides images of dish illumination pattern, allowing characterization of as-built mirror surfaces. The ATA dishes can experience mm-scale distortions across -2 meter lengths due to mounting stresses or solar radiation. Experimental RMS errors are 0.7 mm at night and 3 mm under worst case solar illumination. For frequencies 4, 10, and 15 GHz, the nighttime values indicate sensitivity losses of 1, 10 and 20 percent, respectively. The ATA.s exceptional wide-bandwidth permits observations over a continuous range 0.5 to 11.2 GHz, and future retrofits may increase this range to 15 GHz. Beam patterns show a slowly varying focus frequency dependence. We prob...

  20. Finite time thermodynamic analysis and optimization of solar-dish Stirling heat engine with regenerative losses

    Directory of Open Access Journals (Sweden)

    Sharma Arjun

    2011-01-01

    Full Text Available The present study investigates the performance of the solar-driven Stirling engine system to maximize the power output and thermal efficiency using the non-linearized heat loss model of the solar dish collector and the irreversible cycle model of the Stirling engine. Finite time thermodynamic analysis has been done for combined system to calculate the finite-rate heat transfer, internal heat losses in the regenerator, conductive thermal bridging losses and finite regeneration process time. The results indicate that exergy efficiency of dish system increases as the effectiveness of regenerator increases but decreases with increase in regenerative time coefficient. It is also found that optimal range of collector temperature and corresponding concentrating ratio are 1000 K~1400 K and 1100~1400, respectively in order to get maximum value of exergy efficiency. It is reported that the exergy efficiency of this dish system can reach the maximum value when operating temperature and concentrating ratio are 1150 K and 1300, respectively.

  1. Method of manufacturing large dish reflectors for a solar concentrator apparatus

    Science.gov (United States)

    Angel, Roger P; Olbert, Blain H

    2011-12-27

    A method of manufacturing monolithic glass reflectors for concentrating sunlight in a solar energy system is disclosed. The method of manufacturing allows large monolithic glass reflectors to be made from float glass in order to realize significant cost savings on the total system cost for a solar energy system. The method of manufacture includes steps of heating a sheet of float glass positioned over a concave mold until the sheet of glass sags and stretches to conform to the shape of the mold. The edges of the dish-shaped glass are rolled for structural stiffening around the periphery. The dish-shaped glass is then silvered to create a dish-shaped mirror that reflects solar radiation to a focus. The surface of the mold that contacts the float glass preferably has a grooved surface profile comprising a plurality of cusps and concave valleys. This grooved profile minimizes the contact area and marring of the specular glass surface, reduces parasitic heat transfer into the mold and increases mold lifetime. The disclosed method of manufacture is capable of high production rates sufficiently fast to accommodate the output of a conventional float glass production line so that monolithic glass reflectors can be produced as quickly as a float glass production can make sheets of float glass to be used in the process.

  2. An Axi-Symmetric Segmented Composite SKA Dish Design: Performance and Production Analysis

    CERN Document Server

    Ivashina, M V; de Vaate, J G bij; Iupikov, O A; Arts, M; Dekker, J; van Ardenne, A

    2011-01-01

    A concept of an axi-symmetric dish as antenna reflector for the next generation radio telescope - the Square Kilometre Array (SKA) - is presented. The reflector is based on the use of novel thermoplastic composite material (reinforced with carbon fibre) in the context of the telescope design with wide band single pixel feeds. The baseline of this design represents an array of 100's to 1000's reflector antennas of 15-m diameter and covers frequencies from <1 to 10 GHz. The purpose of our study is the analysis of the production cost of the dish and its performance in combination with a realistic wideband feed (such as the 'Eleven Antenna' feed) over a wide frequency band and a range of elevation angles. The presented initial simulation results inidicate the potential of the proposed dish concept for low-cost and mass production and demonstrate sensitivity comparable to that of the presently considered off-set Gregorian reflector antenna with the same projected aperture area. We expect this observation to be ...

  3. The Hydrogen Epoch of Reionization Array Dish I: Beam Pattern Measurements and Science Implications

    CERN Document Server

    Neben, Abraham R; Hewitt, Jacqueline N; DeBoer, David R; Parsons, Aaron R; Aguirre, James E; Ali, Zaki S; Cheng, Carina; Ewall-Wice, Aaron; Patra, Nipanjana; Thyagarajan, Nithyanandan; Bowman, Judd; Dickenson, Roger; Dillon, Joshua S; Doolittle, Phillip; Egan, Dennis; Hedrick, Mike; Jacobs, Daniel C; Kohn, Saul A; Klima, Patricia J; Moodley, Kavilan; Saliwanchik, Benjamin R B; Schaffner, Patrick; Shelton, John; Taylor, H A; Taylor, Rusty; Tegmark, Max; Wirt, Butch; Zheng, Haoxuan

    2016-01-01

    The Hydrogen Epoch of Reionization Array (HERA) is a radio interferometer aiming to detect the power spectrum of 21cm fluctuations from neutral hydrogen from the Epoch of Reionization (EOR). Drawing on lessons from the Murchison Widefield Array (MWA) and the Precision Array for Probing the Epoch of Reionization (PAPER), HERA is a hexagonal array of large (14m diameter) dishes with suspended dipole feeds. Not only does the dish determine overall sensitivity, it affects the observed frequency structure of foregrounds in the interferometer. This is the first of a series of four papers characterizing the frequency and angular response of the dish with simulations and measurements. We focus in this paper on the angular response (i.e., power pattern), which sets the relative weighting between sky regions of high and low delay, and thus, apparent source frequency structure. We measure the angular response at 137MHz using the ORBCOMM beam mapping system of Neben et al. We measure a collecting area of 93m^2 in the opt...

  4. Recycling of Plastic

    DEFF Research Database (Denmark)

    Christensen, Thomas Højlund; Fruergaard, Thilde

    2011-01-01

    Plastic is produced from fossil oil. Plastic is used for many different products. Some plastic products like, for example, wrapping foil, bags and disposable containers for food and beverage have very short lifetimes and thus constitute a major fraction of most waste. Other plastic products like......, good strength and long durability. Recycling of plastic waste from production is well-established, while recycling of postconsumer plastic waste still is in its infancy. This chapter describes briefly how plastic is produced and how waste plastic is recycled in the industry. Quality requirements...

  5. e-Commerce and supply chains: Modelling of dynamics through fuzzy enhanced high level petri net

    Indian Academy of Sciences (India)

    Vipul Jain; S Wadhwa; S G Deshmukh

    2005-04-01

    Although information plays a major role in effective functioning of supply chain networks (SCNs), studies that deal specifically with the dynamics of supply chains are few. This problem is relatively new since fast communications and the means to employ it for effective management of supply chains did not exist till recently. In order to provide a vehicle for dynamic modelling and analysis of supply chain operations in vague and uncertain environments, we propose a fuzzy enhanced high level petri net (FEHLPN) model. The proposed model captures the capability of petri nets for graphical and analytical representation of dynamic SCNs with the management of uncertain information provided by fuzzy logic. The dynamics associated with two production planning and control policies are modelled, viz. make-to-stock and assemble-to-order in vague and ambiguous situations in electronic commerce environment. A fuzzy set and fuzzy truth-values are attached to an uncertain fuzzy token to model imprecision and uncertainty. The proposed FEHLPN incorporates essential aspects of rule-based systems, such as conservation of facts, refraction, and closed-world assumption.

  6. Control of Discrete-Event Systems Automata and Petri Net Perspectives

    CERN Document Server

    Silva, Manuel; Schuppen, Jan

    2013-01-01

    Control of Discrete-event Systems provides a survey of the most important topics in the discrete-event systems theory with particular focus on finite-state automata, Petri nets and max-plus algebra. Coverage ranges from introductory material on the basic notions and definitions of discrete-event systems to more recent results. Special attention is given to results on supervisory control, state estimation and fault diagnosis of both centralized and distributed/decentralized systems developed in the framework of the Distributed Supervisory Control of Large Plants (DISC) project. Later parts of the text are devoted to the study of congested systems though fluidization, an over approximation allowing a much more efficient study of observation and control problems of timed Petri nets. Finally, the max-plus algebraic approach to the analysis and control of choice-free systems is also considered. Control of Discrete-event Systems provides an introduction to discrete-event systems for readers that are not familiar wi...

  7. Evaluation of Cyber Security and Modelling of Risk Propagation with Petri Nets

    Directory of Open Access Journals (Sweden)

    Marcin Szpyrka

    2017-02-01

    Full Text Available This article presents a new method of risk propagation among associated elements. On thebasis of coloured Petri nets, a new class called propagation nets is defined. This class providesa formal model of a risk propagation. The proposed method allows for model relations betweennodes forming the network structure. Additionally, it takes into account the bidirectional relationsbetween components as well as relations between isomorphic, symmetrical components in variousbranches of the network. This method is agnostic in terms of use in various systems and it canbe adapted to the propagation model of any systems’ characteristics; however, it is intentionallyproposed to assess the risk of critical infrastructures. In this paper, as a proof of concept example, weshow the formal model of risk propagation proposed within the project Cyberspace Security ThreatsEvaluation System of the Republic of Poland. In the article, the idea of the method is presented aswell as its use case for evaluation of risk for cyber threats. With the adaptation of Petri nets, it ispossible to evaluate the risk for the particular node and assess the impact of this risk for all relatednodes including hierarchic relations of components as well as isomorphism of elements.

  8. Deciding the liveness for a subclass of weighted Petri nets based on structurally circular wait

    Science.gov (United States)

    Liu, GuanJun; Chen, LiJing

    2016-05-01

    Weighted Petri nets as a kind of formal language are widely used to model and verify discrete event systems related to resource allocation like flexible manufacturing systems. System of Simple Sequential Processes with Multi-Resources (S3PMR, a subclass of weighted Petri nets and an important extension to the well-known System of Simple Sequential Processes with Resources, can model many discrete event systems in which (1) multiple processes may run in parallel and (2) each execution step of each process may use multiple units from multiple resource types. This paper gives a necessary and sufficient condition for the liveness of S3PMR. A new structural concept called Structurally Circular Wait (SCW) is proposed for S3PMR. Blocking Marking (BM) associated with an SCW is defined. It is proven that a marked S3PMR is live if and only if each SCW has no BM. We use an example of multi-processor system-on-chip to show that SCW and BM can precisely characterise the (partial) deadlocks for S3PMR. Simultaneously, two examples are used to show the advantages of SCW in preventing deadlocks of S3PMR. These results are significant for the further research on dealing with the deadlock problem.

  9. Modeling and Optimizing Energy Utilization of Steel Production Process: A Hybrid Petri Net Approach

    Directory of Open Access Journals (Sweden)

    Peng Wang

    2013-01-01

    Full Text Available The steel industry is responsible for nearly 9% of anthropogenic energy utilization in the world. It is urgent to reduce the total energy utilization of steel industry under the huge pressures on reducing energy consumption and CO2 emission. Meanwhile, the steel manufacturing is a typical continuous-discrete process with multiprocedures, multiobjects, multiconstraints, and multimachines coupled, which makes energy management rather difficult. In order to study the energy flow within the real steel production process, this paper presents a new modeling and optimization method for the process based on Hybrid Petri Nets (HPN in consideration of the situation above. Firstly, we introduce the detailed description of HPN. Then the real steel production process from one typical integrated steel plant is transformed into Hybrid Petri Net model as a case. Furthermore, we obtain a series of constraints of our optimization model from this model. In consideration of the real process situation, we pick the steel production, energy efficiency and self-made gas surplus as the main optimized goals in this paper. Afterwards, a fuzzy linear programming method is conducted to obtain the multiobjective optimization results. Finally, some measures are suggested to improve this low efficiency and high whole cost process structure.

  10. High performance hybrid functional Petri net simulations of biological pathway models on CUDA.

    Science.gov (United States)

    Chalkidis, Georgios; Nagasaki, Masao; Miyano, Satoru

    2011-01-01

    Hybrid functional Petri nets are a wide-spread tool for representing and simulating biological models. Due to their potential of providing virtual drug testing environments, biological simulations have a growing impact on pharmaceutical research. Continuous research advancements in biology and medicine lead to exponentially increasing simulation times, thus raising the demand for performance accelerations by efficient and inexpensive parallel computation solutions. Recent developments in the field of general-purpose computation on graphics processing units (GPGPU) enabled the scientific community to port a variety of compute intensive algorithms onto the graphics processing unit (GPU). This work presents the first scheme for mapping biological hybrid functional Petri net models, which can handle both discrete and continuous entities, onto compute unified device architecture (CUDA) enabled GPUs. GPU accelerated simulations are observed to run up to 18 times faster than sequential implementations. Simulating the cell boundary formation by Delta-Notch signaling on a CUDA enabled GPU results in a speedup of approximately 7x for a model containing 1,600 cells.

  11. Systematic Process for Building a Fault Diagnoser Based on Petri Nets Applied to a Helicopter

    Directory of Open Access Journals (Sweden)

    Miguel A. Trigos

    2015-01-01

    Full Text Available This work presents a systematic process for building a Fault Diagnoser (FD, based on Petri Nets (PNs which has been applied to a small helicopter. This novel tool is able to detect both intermittent and permanent faults. The work carried out is discussed from theoretical and practical point of view. The procedure begins with a division of the whole system into subsystems, which are the devices that have to be modeled by using PN, considering both the normal and fault operations. Subsequently, the models are integrated into a global Petri Net diagnoser (PND that is able to monitor a whole helicopter and show critical variables to the operator in order to determine the UAV health, preventing accidents in this manner. A Data Acquisition System (DAQ has been designed for collecting data during the flights and feeding PN diagnoser with them. Several real flights (nominal or under failure have been carried out to perform the diagnoser setup and verify its performance. A summary of the validation results obtained during real flight tests is also included. An extensive use of this tool will improve preventive maintenance protocols for UAVs (especially helicopters and allow establishing recommendations in regulations.

  12. Analysis of Phase-Type Stochastic Petri Nets With Discrete and Continuous Timing

    Science.gov (United States)

    Jones, Robert L.; Goode, Plesent W. (Technical Monitor)

    2000-01-01

    The Petri net formalism is useful in studying many discrete-state, discrete-event systems exhibiting concurrency, synchronization, and other complex behavior. As a bipartite graph, the net can conveniently capture salient aspects of the system. As a mathematical tool, the net can specify an analyzable state space. Indeed, one can reason about certain qualitative properties (from state occupancies) and how they arise (the sequence of events leading there). By introducing deterministic or random delays, the model is forced to sojourn in states some amount of time, giving rise to an underlying stochastic process, one that can be specified in a compact way and capable of providing quantitative, probabilistic measures. We formalize a new non-Markovian extension to the Petri net that captures both discrete and continuous timing in the same model. The approach affords efficient, stationary analysis in most cases and efficient transient analysis under certain restrictions. Moreover, this new formalism has the added benefit in modeling fidelity stemming from the simultaneous capture of discrete- and continuous-time events (as opposed to capturing only one and approximating the other). We show how the underlying stochastic process, which is non-Markovian, can be resolved into simpler Markovian problems that enjoy efficient solutions. Solution algorithms are provided that can be easily programmed.

  13. Modularization of biochemical networks based on classification of Petri net t-invariants

    Directory of Open Access Journals (Sweden)

    Grunwald Stefanie

    2008-02-01

    Full Text Available Abstract Background Structural analysis of biochemical networks is a growing field in bioinformatics and systems biology. The availability of an increasing amount of biological data from molecular biological networks promises a deeper understanding but confronts researchers with the problem of combinatorial explosion. The amount of qualitative network data is growing much faster than the amount of quantitative data, such as enzyme kinetics. In many cases it is even impossible to measure quantitative data because of limitations of experimental methods, or for ethical reasons. Thus, a huge amount of qualitative data, such as interaction data, is available, but it was not sufficiently used for modeling purposes, until now. New approaches have been developed, but the complexity of data often limits the application of many of the methods. Biochemical Petri nets make it possible to explore static and dynamic qualitative system properties. One Petri net approach is model validation based on the computation of the system's invariant properties, focusing on t-invariants. T-invariants correspond to subnetworks, which describe the basic system behavior. With increasing system complexity, the basic behavior can only be expressed by a huge number of t-invariants. According to our validation criteria for biochemical Petri nets, the necessary verification of the biological meaning, by interpreting each subnetwork (t-invariant manually, is not possible anymore. Thus, an automated, biologically meaningful classification would be helpful in analyzing t-invariants, and supporting the understanding of the basic behavior of the considered biological system. Methods Here, we introduce a new approach to automatically classify t-invariants to cope with network complexity. We apply clustering techniques such as UPGMA, Complete Linkage, Single Linkage, and Neighbor Joining in combination with different distance measures to get biologically meaningful clusters (t

  14. Cabbage Dish

    Institute of Scientific and Technical Information of China (English)

    1994-01-01

    Ingredients: 500 grams of cabbage, 40 grams of winter bamboo shoots, 40 grams of rehydrated winter mushrooms, 20 grams of green pepper, 20 grams of red pepper, 30 grams of scallions, 10 grams of ginger, 20-40 grams of chili pepper, 50 grams of salt, 50

  15. MODELLING OF AN INEXPENSIVE 9M SATELLITE DISH FROM 3D POINT CLOUDS CAPTURED BY TERRESTRIAL LASER SCANNERS

    Directory of Open Access Journals (Sweden)

    D. Belton

    2012-09-01

    Full Text Available This paper presents the use of Terrestrial laser scanners (TLS to model the surface of satellite dish. In this case, the dish was an inexpensive 9m parabolic satellite dish with a mesh surface, and was to be utilised in radio astronomy. The aim of the modelling process was to determine the deviation of the surface away from its true parabolic shape, in order to estimate the surface efficiency with respect to its principal receiving frequency. The main mathematical problems were the optimal and unbiased estimation the orientation of the dish and the fitting of a parabola to the local orientation or coordinate system, which were done by both orthogonal and algebraic minimization using the least-squares method. Due to the mesh structure of the dish, a classification method was also applied to filter out erroneous points being influenced by the supporting structure behind the dish. Finally, a comparison is performed between the ideal parabolic shape, and the data collected from three different temporal intervals.

  16. Description of Software Architecture Based on Petri Net%基于Petri Net软件体系结构模型的描述

    Institute of Scientific and Technical Information of China (English)

    周国强; 陈春玲

    2002-01-01

    软件体系结构是软件工程中一个新兴的研究热点,但是没有一个比较通用的描述规范.因此体系结构的完整性、一致性和正确性等都无法保证.该文提出的一个Petri Net的扩展理论,给出了抽象库所和抽象变迁的概念,为构件的信息隐藏、控制流的抽象提供了可能;同时对重用有特别意义的继承机制在PN中的表示进行了比较详细介绍,吸取了PN强大而完整的描述能力,严谨的验证体系.为软件体系结构描述的正确性提供了一个比较简单,但是完整的基于Net的描述方法.

  17. Designing Tool Support for Translating Use Cases and UML 2.0 Sequence Diagrams into a Coloured Petri Net

    DEFF Research Database (Denmark)

    Fernandes, Joao Miguel; Tjell, Simon; Jørgensen, Jens Bæk

    2007-01-01

    On a case study on the specification of an elevator controller, this paper presents an approach that can translate given UML descriptions into a Coloured Petri Net (CPN) model. The UML descriptions must be specified in the form of Use Cases (UCs) and UML 2.0 Sequence Diagrams (SDs). The CPN model...

  18. Petri Net Simulation of Critical Consumables aboard the International Space Station

    Science.gov (United States)

    Benjamin, Allan; Turner, Ryan; Sher, Josh; Heard, Addison; Linsday, James

    2005-12-01

    The level of carbon dioxide (CO2), water (H2O), or oxygen (O2) aboard the International Space Station (ISS) at any given time is a function of the number of crew and the availability of critical life support systems characterized by their respective mean time between failure (MTBF) and mean time to repair (MTTR) parameters. The non-linear interaction between these elements requires a simulation approach to probability calculations in lieu of a static fault or event tree model. We have chosen to implement our models as a particular type of finite state machine called a Petri net, an architecture that permits both stochastic (random) and deterministic events. To run the Petri net, we combined an existing freeware Petri net graphical user interface (GUI) with our own Excel/Visual Basic for Applications (VBA) simulation code in a platform that facilitates the design, analysis, and verification of model logic. A single run through the model represents a single possible timeline aboard the ISS, with random failures of equipment and repair times distributed according to the best available probability data. By running the model with the same input parameters a large number of times in a Monte Carlo analysis, we derived with high confidence the probabilities of occurrence of specific events of interest (in this case, exceedances of critical consumable thresholds) during a selected mission interval with much greater fidelity than is possible without simulation. The analytical approach presented in this paper has potential applicability to analogous integrated system simulation problems in a wide variety of settings.As part of the background leading to the theoretical development for ISS consumables, the paper starts with a synopsis of methods recently developed at ARES Corporation to address two related return-to- flight issues. The first concerns the determination of the likelihood that a fragment from the shuttle external tank could impact the orbiter and cause critical

  19. Avoidance tests with Folsomia candida for the assessment of copper contamination in agricultural soils

    Energy Technology Data Exchange (ETDEWEB)

    Boiteau, G., E-mail: Gilles.Boiteau@agr.gc.ca [Agriculture and Agri-Food Canada, Potato Research Center, 850 Lincoln Road, P.O. Box 20280, Fredericton, NB, E3B 4Z7 (Canada); Lynch, D.H. [Nova Scotia Agricultural College, P.O. Box 550, Truro NS, B2N 4L2 (Canada); MacKinley, P. [Agriculture and Agri-Food Canada, Potato Research Center, 850 Lincoln Road, P.O. Box 20280, Fredericton, NB, E3B 4Z7 (Canada)

    2011-04-15

    The feasibility of assessing copper accumulation in agricultural soils using avoidance tests with a Canadian strain of Folsomia candida was investigated under laboratory conditions. The avoidance response to nominal copper sulfate concentrations of 0, 200, 800, 1600 and 3200 mg kg{sup -1} in OECD soil was inconsistent between trials with the standard plastic cup or a modified Petri dish method requiring less soil. However, combined results from three Petri dish trials decreased variability and provided a 75% avoidance level, close to the 80% criterion proposed for avoidance tests. A Copper avoidance EC{sub 50s} of 18 mg kg{sup -1}was obtained using the Petri dish method whether tests were conducted with or without light. While Petri dish tests have potential as a cheap tool to distinguish metal contaminated soils from uncontaminated soils they would be unsuitable for tracking or quantifying changes in metal concentrations. throughout remediation. Advantages and limitations of the method have been presented. - Research highlights: > Avoidance cup test using Folsomia candida detects Cu independently of concentration. > Improved avoidance Petri dish test detects Cu in soil in function of concentration. > Cu voidance tests had similar EC50 values whether conducted with or without light. > Combining Cu avoidance test trials in OECD soil reduced the variability of results. - Improved avoidance tests having an EC{sub 50} value similar to the background Cu concentration in uncontaminated agricultural soils can distinguish Cu contaminated and Cu free OECD soil.

  20. The design of the local monitor and control system of SKA dishes

    Science.gov (United States)

    Schillirò, F.; Baldini, V.; Becciani, U.; Cirami, R.; Costa, A.; Ingallinera, A.; Marassi, A.; Nicotra, G.; Nocita, C.; Riggi, S.; Trigilio, C.

    2016-08-01

    The Square Kilometer Array (SKA) project aims at building the world's largest radio observatory to observe the sky with unprecedented sensitivity and collecting area. In the first phase of the project (SKA1), an array of dishes, SKA1-MID, will be built in South Africa. It will consist of 133 15m-dishes, which will include the MeerKAT array, for the 0.350-20 GHz frequency band observations. Each antenna will be provided with a local monitor and control system (LMC), enabling operations both to the Telescope Manager remote system, and to the engineers and maintenance staff; it provides different environment for the telescope control (positioning, pointing, observational bands), metadata collection for monitoring and database storaging, operational modes and functional states management for all the telescope capabilities. In this paper we present the LMC software architecture designed for the detailed design phase (DD), where we describe functional and physical interfaces with monitored and controlled sub-elements, and highlight the data flow between each LMC modules and its sub-element controllers from one side, and Telescope Manager on the other side. We also describe the complete Product Breakdown Structure (PBS) created in order to optimize resources allocation in terms of calculus and memory, able to perform required task for each element according to the proper requirements. Among them, time response and system reliability are the most important, considering the complexity of SKA dish network and its isolated placement. Performances obtained by software implementation using TANGO framework will be discussed, matching them with technical requirements derived by SKA science drivers.

  1. A PetriNet-Based Approach for Supporting Traceability in Cyber-Physical Manufacturing Systems

    Directory of Open Access Journals (Sweden)

    Jiwei Huang

    2016-03-01

    Full Text Available With the growing popularity of complex dynamic activities in manufacturing processes, traceability of the entire life of every product has drawn significant attention especially for food, clinical materials, and similar items. This paper studies the traceability issue in cyber-physical manufacturing systems from a theoretical viewpoint. Petri net models are generalized for formulating dynamic manufacturing processes, based on which a detailed approach for enabling traceability analysis is presented. Models as well as algorithms are carefully designed, which can trace back the lifecycle of a possibly contaminated item. A practical prototype system for supporting traceability is designed, and a real-life case study of a quality control system for bee products is presented to validate the effectiveness of the approach.

  2. Decision-making of selectable process plans based on petri net with manufacturing constraints

    DEFF Research Database (Denmark)

    Xiao, Weiyue; Jones, Richard William; Yu, Fei

    2016-01-01

    Intelligent Computer-Aided process planning and decision making for manufacturing systems is a critical subject, that some might argue, has not received the attention it should have from the research community. Despite the progress made in the area of artificial intelligence, there has not been......-invariant, namely the non-negative integer solution of a linear equation set. Two examples verify the effectiveness of the proposed method indicating that the proposed T-invariant decision-making approach can be used to achieve desired optimal/suboptimal process plans for a machinery manufacturing system....... a major step forward in the area of intelligent computer-Aided process planning. Petri nets provide a powerful tool to characterize, model and analyse discrete events dynamic systems. However, the efforts on process planning in machinery manufacturing systems have very limited use in practise. This paper...

  3. Diagnosis of Intermittent Faults in IGBTs Using the Latent Nestling Method with Hybrid Coloured Petri Nets

    Directory of Open Access Journals (Sweden)

    Leonardo Rodriguez-Urrego

    2015-01-01

    Full Text Available This paper presents a fault diagnosis application of the Latent Nestling Method to IGBTs. The paper extends the Latent Nestling Method based in Coloured Petri Nets (CPNs to hybrid systems in such a manner that IGBTs performance can be modeled. CPNs allow for an enhanced capability for synthesis and modeling in contrast to the classical phenomena of combinational state explosion when Finite State Machine methods are applied. We present an IGBT model with different fault modes including those of intermittent nature that can be used advantageously as predictive symptoms within a predictive maintenance strategy. Ageing stress tests have been experimentally applied to the IGBTs modules and intermittent faults are diagnosed as precursors of permanent failures. In addition, ageing is validated with morphological analysis (Scanning Electron Microscopy and semiqualitative analysis (Energy Dispersive Spectrometry.

  4. The ADAPT Tool: From AADL Architectural Models to Stochastic Petri Nets through Model Transformation

    CERN Document Server

    Rugina, Ana E; Kaaniche, Mohamed

    2008-01-01

    ADAPT is a tool that aims at easing the task of evaluating dependability measures in the context of modern model driven engineering processes based on AADL (Architecture Analysis and Design Language). Hence, its input is an AADL architectural model annotated with dependability-related information. Its output is a dependability evaluation model in the form of a Generalized Stochastic Petri Net (GSPN). The latter can be processed by existing dependability evaluation tools, to compute quantitative measures such as reliability, availability, etc.. ADAPT interfaces OSATE (the Open Source AADL Tool Environment) on the AADL side and SURF-2, on the dependability evaluation side. In addition, ADAPT provides the GSPN in XML/XMI format, which represents a gateway to other dependability evaluation tools, as the processing techniques for XML files allow it to be easily converted to a tool-specific GSPN.

  5. Application of Coloured Petri Nets for Verification of Scenario Control Structures in UCM Notation

    Directory of Open Access Journals (Sweden)

    N. V. Vizovitin

    2016-01-01

    Full Text Available This article presents a method for the analysis and verification of Use Case Maps (UCM models with scenario control structures — protected components and failure handling constructs. UCM models are analyzed and verified with the help of coloured Petri nets (CPN and the SPIN model checker. Algorithms for translating UCM scenario control structures into CPN and CPN into SPIN input language Promela are described. The number of elements of the resulting CPN model and the number of Promela model states are estimated. The presented algorithm and the verification process are illustrated by the study of a network router firmware update.

  6. Simulación de un sistema de manufactura flexible con redes de Petri coloreadas

    Directory of Open Access Journals (Sweden)

    Luis Diego Murillo Soto

    2010-10-01

    Full Text Available Una forma de estudiar un sistema de manufactura flexible es por medio de un modelo del sistema y someterlo a un simulacro para observar sus índices de comportamiento, gráficas, etc. Siguiendo esta pauta, el presente trabajo plantea la simulación de una línea de producción con tres máquinas, dos robots y tres tipos de productos distintos. Con dicho sistema se desea obtener, en forma automática, porcentajes del uso de las máquinas, tamaño promedio de las colas, gráficas del comportamiento de las colas y el diagrama Gantt. El modelado de la línea de producción se realizó con Redes de Petri Coloreadas (RdPC y su implementación se realizó con la herramienta CPNTool.

  7. Automatic Supervisory System Synthesis for Port Cranes Collision Prevention by Using Petri Net

    Directory of Open Access Journals (Sweden)

    Danko Kezić

    2006-05-01

    Full Text Available The article deals with the system of port cranes comprisingtwo independently controlled cranes which are simultaneouslyengaged in the transhipment of cargo between a vessel and arailway wagon assembly alongside. The crane operator's errorcan lead to tlie collision of cranes. Therefore, it is necessary toinstall the supervisor in an automatic control system with thefunctions of continuous supervision of the process of cranemovement, and blocking of commands that can lead to collision.The article shows the method of crane system modellingas a discrete event system by using PIT and P-timed Petri nets.There is a proposal of a formal mathematic method for calculationof the state supervisor by P-invariant method. The supervisorcalculated in this way is maximally permissive supervisor.The efficiency of the supervisor is verified by a computer simulation.

  8. Dependency Modeling of a SOA Based System Through Colored Petri Nets

    Directory of Open Access Journals (Sweden)

    Pawan Kumar

    2016-09-01

    Full Text Available Dependency relationships play an important role in testing, maintenance and configuration management of software systems. The informal dependency representations fail to observe behavioral connections among subsystems and cause ambiguity in representing different types of dependency relationships. Therefore, dependency in a software system requires a formal and unambiguous representation so that its correct effects can be visualized. In this paper, we present a Colored Petri Net based dependency analysis of a Service Oriented Architecture (SOA based system that represents specification of dependency relationships and models the dependencies in a SOA based system at conceptual level. Different types of dependency relations are represented in a formal manner by using Service Algebra. A module SOA based system ‘Online Bookshop’ has been developed and used for the purpose of modeling and example demonstration. Such modeling can help in identification of inconsistency among services, and web services can be verified for safety and reliability.

  9. Improved methods for scheduling flexible manufacturing systems based on Petri nets and heuristic search

    Institute of Scientific and Technical Information of China (English)

    Bo HUANG; Yamin SUN

    2005-01-01

    This paper proposes and evaluates two improved Petri net (PN)-based hybrid search strategies and their applications to flexible manufacturing system (FMS) scheduling.The algorithms proposed in some previous papers,which combine PN simulation capabilities with A* heuristic search within the PN reachability graph,may not find an optimum solution even with an admissible heuristic function.To remedy the defects an improved heuristic search strategy is proposed,which adopts a different method for selecting the promising markings and reserves the admissibility of the algorithm.To speed up the search process,another algorithm is also proposed which invokes faster termination conditions and still guarantees that the solution found is optimum.The scheduling results are compared through a simple FMS between our algorithms and the previous methods.They are also applied and evaluated in a set of randomly-generated FMSs with such characteristics as multiple resources and alternative routes.

  10. A reliable routing algorithm based on fuzzy Petri net in mobile ad hoc networks

    Institute of Scientific and Technical Information of China (English)

    HU Zhi-gang; MA Hao; WANG Guo-jun; LIAO Lin

    2005-01-01

    A novel reliable routing algorithm in mobile ad hoc networks using fuzzy Petri net with its reasoning mechanism was proposed to increase the reliability during the routing selection. The algorithm allows the structured representation of network topology, which has a fuzzy reasoning mechanism for finding the routing sprouting tree from the source node to the destination node in the mobile ad hoc environment. Finally, by comparing the degree of reliability in the routing sprouting tree, the most reliable route can be computed. The algorithm not only offers the local reliability between each neighboring node, but also provides global reliability for the whole selected route. The algorithm can be applied to most existing on-demand routing protocols, and the simulation results show that the routing reliability is increased by more than 80% when applying the proposed algorithm to the ad hoc on demand distance vector routing protocol.

  11. Analysis of Petri net model and task planning heuristic algorithms for product reconfiguration

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    Reconfiguration planning is recognized as an important factor for reducing the cost of manufacturing reconfigurable products, and the associated main task is to generate a set of optimal or near-optimal reconfiguration sequences using some effect algorithms. A method is developed to generate a Petri net as the reconfiguration tree to represent two-state-transit of product, which solved the representation problem of reconfiguring interfaces replacement. Relating with this method, two heuristic algorithms are proposed to generate task sequences which considering economics to search reconfiguration paths effectively. At last,an objective evaluation is applied to compare these two heuristic algorithms to other ones. The developed reconfiguration task planning heuristic algorithms can generate better strategies and plans for reconfiguration. The research finds are exemplified with struts reconfiguration of reconfigurable parallel kinematics machine (RPKM).

  12. Web Services modeling and composition approach using Objects-Oriented Petri Nets

    Directory of Open Access Journals (Sweden)

    Sofiane Chemaa

    2012-07-01

    Full Text Available Nowadays, with the emergence and the evolution of new technologies, such as e-business, a large number of companies are connected to Internet, and have proposed web services to trade. Web services as presented, are conceptually limited components to relatively simple functionalities. Generally, a single service does not satisfy the users needs that are more and more complex. Therefore, services must be made able to be composed to offer added value services. In this paper, a web services composition approach, modelled by Objects-Oriented Petri nets, is presented. In his context, an expressive algebra, which successfully solves the web services complex composition problem, is proposed. A java tool that allows automating this approach; based on a definite algebra and a G-nets meta-model, proposed by us, is developed.

  13. Reachability analysis of a class of Petri nets using place invariants and siphons

    Directory of Open Access Journals (Sweden)

    Zhi Wu Li

    2013-07-01

    Full Text Available This paper proposes a novel and computationally efficient approach to deal with the reachability problem by using place invariants and strict minimal siphons for a class of Petri nets called pipe-line nets (PLNs. First, in a PLN with an appropriate initial marking, the set of invariant markings and the set of strict minimal siphons are enumerated. Then a sufficient and necessary condition is developed to decide whether a marking is spurious by analysing the number of tokens in operation places of any strict minimal siphon and their bounds. Furthermore, an algorithm that generates the reachable markings by removing all the spurious markings from the set of invariant markings is proposed. Finally, experimental results show the efficiency of the proposed method.

  14. Modelling and analysis of the feeding regimen induced entrainment of hepatocyte circadian oscillators using petri nets.

    Directory of Open Access Journals (Sweden)

    Samar Hayat Khan Tareen

    Full Text Available Circadian rhythms are certain periodic behaviours exhibited by living organism at different levels, including cellular and system-wide scales. Recent studies have found that the circadian rhythms of several peripheral organs in mammals, such as the liver, are able to entrain their clocks to received signals independent of other system level clocks, in particular when responding to signals generated during feeding. These studies have found SIRT1, PARP1, and HSF1 proteins to be the major influencers of the core CLOCKBMAL1:PER-CRY circadian clock. These entities, along with abstracted feeding induced signals were modelled collectively in this study using Petri Nets. The properties of the model show that the circadian system itself is strongly robust, and is able to continually evolve. The modelled feeding regimens suggest that the usual 3 meals/day and 2 meals/day feeding regimens are beneficial with any more or less meals/day negatively affecting the system.

  15. Modelling and analysis of the feeding regimen induced entrainment of hepatocyte circadian oscillators using petri nets.

    Science.gov (United States)

    Tareen, Samar Hayat Khan; Ahmad, Jamil

    2015-01-01

    Circadian rhythms are certain periodic behaviours exhibited by living organism at different levels, including cellular and system-wide scales. Recent studies have found that the circadian rhythms of several peripheral organs in mammals, such as the liver, are able to entrain their clocks to received signals independent of other system level clocks, in particular when responding to signals generated during feeding. These studies have found SIRT1, PARP1, and HSF1 proteins to be the major influencers of the core CLOCKBMAL1:PER-CRY circadian clock. These entities, along with abstracted feeding induced signals were modelled collectively in this study using Petri Nets. The properties of the model show that the circadian system itself is strongly robust, and is able to continually evolve. The modelled feeding regimens suggest that the usual 3 meals/day and 2 meals/day feeding regimens are beneficial with any more or less meals/day negatively affecting the system.

  16. Supervisory control based on minimal cuts and Petri net sub-controllers coordination

    Science.gov (United States)

    Rezig, Sadok; Achour, Zied; Rezg, Nidhal; Kammoun, Mohamed-Ali

    2016-10-01

    This paper addresses the synthesis of Petri net (PN) controller for the forbidden state transition problem with a new utilisation of the theory of regions. Moreover, as any method of control synthesis based on a reachability graph, the theory of regions suffers from the combinatorial explosion problem. The proposed work minimises the number of equations in the linear system of theory of regions and therefore one can reduce the computation time. In this paper, two different approaches are proposed to select minimal cuts in the reachability graph in order to synthesise a PN controller. Thanks to a switch from one cut to another, one can activate and deactivate the corresponding PNcontroller. An application is implemented in a flexible manufacturing system to illustrate the present method. Finally, comparison with previous works with experimental results in obtaining a maximally permissive controller is presented.

  17. Manganese Oxidation in Petri Disease Fungi as a Novel Taxonomic Character

    Directory of Open Access Journals (Sweden)

    B.E. Overton

    2006-04-01

    Full Text Available Manganese (Mn oxidation was evaluated for Petri disease fungi by using potato dextrose agar (PDA amended with Mn sulfate. Phaeomoniella chlamydospora showed reduced growth on PDA amended with 3000 ppm Mn sulfate and exhibited no growth at higher concentrations. All Phaeoacremonium spp. evaluated were manganese tolerant and grew on PDA amended with as much as 6000 ppm Mn sulfate. Phaeoacremonium viticola and P. angustius s.s. oxidized manganese in vitro. Stereum hirsutum and Fomitiporia punctata, known white-rot basidiomycetes, were used as controls. Stereum hirsutum oxidized Mn in vitro and grew on PDA amended with 6000 ppm Mn sulfate. Fomitiporia punctata had reduced growth at 300 ppm and no growth at higher concentrations of Mn sulfate with no clear evidence of Mn oxidation.

  18. Sequence Diagram Test Case Specification and Virtual Integration Analysis using Timed-Arc Petri Nets

    Directory of Open Access Journals (Sweden)

    Sven Sieverding

    2013-02-01

    Full Text Available In this paper, we formally define Test Case Sequence Diagrams (TCSD as an easy-to-use means to specify test cases for components including timing constraints. These test cases are modeled using the UML2 syntax and can be specified by standard UML-modeling-tools. In a component-based design an early identification of errors can be achieved by a virtual integration of components before the actual system is build. We define such a procedure which integrates the individual test cases of the components according to the interconnections of a given architecture and checks if all specified communication sequences are consistent. Therefore, we formally define the transformation of TCSD into timed-arc Petri nets and a process for the combination of these nets. The applicability of our approach is demonstrated on an avionic use case from the ARP4761 standard.

  19. Formal and Executable Specification of Random Waypoint Mobility Model Using Timed Coloured Petri Nets for WMN

    Directory of Open Access Journals (Sweden)

    Naeem Akhtar Khan

    2014-01-01

    Full Text Available The wireless mesh network (WMN is an emerging and cost-effective alternative paradigm for the next generation wireless networks in many diverse applications. In the performance evaluation of routing protocol for the WMN, it is essential that it should be evaluated under realistic conditions. The usefulness of specific mobility protocol can be determined by selection of mobility model. This paper introduces a coloured Petri nets (CP-nets based formal model for implementation, simulation, and analysis of most widely used random waypoint (RWP mobility model for WMNs. The formal semantics of hierarchical timed CP-nets allow us to investigate the terminating behavior of the transitions using state space analysis techniques. The proposed implementation improves the RWP mobility model by removing the “border effect” and resolves the “speed decay” problem.

  20. The use of the Petri net method in the simulation modeling of mitochondrial swelling

    Directory of Open Access Journals (Sweden)

    Yu. V. Danylovych

    2016-08-01

    Full Text Available Using photon correlation spectroscopy, which allows investigating changes in the hydrodynamic dia­meter of the particles in suspension, it was shown that ultrahigh concentrations of Ca2+ (over 10 mM induce swelling of isolated mitochondria. An increase in hydrodynamic diameter was caused by an increase of non-specific mitochondrial membrane permeability to Ca ions, matrix Ca2+ overload, activation of ATP- and Ca2+-sensitive K+-channels, as well as activation of cyclosporin-sensitive permeability transition pore. To formalize the experimental data and to assess conformity of experimental results with theoretical predictions we developed a simulation model using the hybrid functional Petri net method.

  1. Petri Nets Based Modelling of Control Flow for Memory-Aid Interactive Programs in Telemedicine

    CERN Document Server

    Khoromskaia, V K

    2004-01-01

    Petri Nets (PN) based modelling of the control flow for the interactive memory assistance programs designed for personal pocket computers and having special requirements for robustness is considered. The proposed concept allows one to elaborate the programs which can give users a variety of possibilities for a day-time planning in the presence of environmental and time restrictions. First, a PN model for a known simple algorithm is constructed and analyzed using the corresponding state equations and incidence matrix. Then a PN graph for a complicated algorithm with overlapping actions and choice possibilities is designed, supplemented by an example of its analysis. Dynamic behaviour of this graph is tested by tracing of all possible paths of the flow of control using the PN simulator. It is shown that PN based modelling provides reliably predictable performance of interactive algorithms with branched structures and concurrency requirements.

  2. A PetriNet-Based Approach for Supporting Traceability in Cyber-Physical Manufacturing Systems.

    Science.gov (United States)

    Huang, Jiwei; Zhu, Yeping; Cheng, Bo; Lin, Chuang; Chen, Junliang

    2016-03-17

    With the growing popularity of complex dynamic activities in manufacturing processes, traceability of the entire life of every product has drawn significant attention especially for food, clinical materials, and similar items. This paper studies the traceability issue in cyber-physical manufacturing systems from a theoretical viewpoint. Petri net models are generalized for formulating dynamic manufacturing processes, based on which a detailed approach for enabling traceability analysis is presented. Models as well as algorithms are carefully designed, which can trace back the lifecycle of a possibly contaminated item. A practical prototype system for supporting traceability is designed, and a real-life case study of a quality control system for bee products is presented to validate the effectiveness of the approach.

  3. Petri net-based scheduling of time constrained single-arm cluster tools with wafer revisiting

    Directory of Open Access Journals (Sweden)

    ZiCheng Liu

    2016-05-01

    Full Text Available It is very difficult to schedule a single-arm cluster tool with wafer revisiting such that wafer residency time constraints are satisfied. This article conducts a study on this challenging problem for a single-arm cluster tool with atomic layer deposition process. With a so-called p-backward strategy being applied, a Petri net model is developed to describe the dynamic behavior of the system. Based on the model, the existence of a feasible schedule is analyzed, schedulability conditions are derived, and scheduling algorithms are presented if there is a schedule. A schedule is obtained by simply setting the robot waiting time if schedulable, and it is very computationally efficient. The obtained schedule is shown to be optimal. Illustrative examples are given to demonstrate the proposed approach.

  4. The kinematic Stirling engine as an energy conversion subsystem for paraboloidal dish solar thermal plants

    Science.gov (United States)

    Bowyer, J. M.

    1984-01-01

    The potential of a suitably designed and economically manufactured Stirling engine as the energy conversion subsystem of a paraboloidal dish-Stirling solar thermal power module was estimated. Results obtained by elementary cycle analyses were shown to match quite well the performance characteristics of an advanced kinematic Stirling engine, the United Stirling P-40, as established by current prototypes of the engine and by a more sophisticated analytic model of its advanced derivative. In addition to performance, brief consideration was given to other Stirling engine criteria such as durability, reliability, and serviceability. Production costs were not considered here.

  5. Using microdispensing to manufacture a customized cell dish for microbeam irradiation of single, living cells

    Energy Technology Data Exchange (ETDEWEB)

    Nilsson, E.J.C. [Division of Nuclear Physics, Department of Physics, Lund Institute of Technology, Lund University, Box 118, S-22100 Lund (Sweden)], E-mail: charlotta.nilsson@nuclear.lu.se; Olsson, M.G. [Division of Infection Medicine, Department of Clinical Sciences, Lund University, S-22184 Lund (Sweden); Nilsson, J. [Department of Electrical Measurements and Industrial Electrical Engineering and Automation, Lund Institute of Technology, Lund University, Box 118, S-22100 Lund (Sweden); Pallon, J.; Masternak, A. [Division of Nuclear Physics, Department of Physics, Lund Institute of Technology, Lund University, Box 118, S-22100 Lund (Sweden); Paczesny, J. [Division of Nuclear Physics, Department of Physics, Lund Institute of Technology, Lund University, Box 118, S-22100 Lund (Sweden); Division of Infection Medicine, Department of Clinical Sciences, Lund University, S-22184 Lund (Sweden); Arteaga-Marrero, N.; Elfman, M.; Kristiansson, P.; Nilsson, C. [Division of Nuclear Physics, Department of Physics, Lund Institute of Technology, Lund University, Box 118, S-22100 Lund (Sweden); Akerstroem, B. [Division of Infection Medicine, Department of Clinical Sciences, Lund University, S-22184 Lund (Sweden)

    2009-04-15

    In this paper is described the preparation of patterned cell dishes to be used in studies of low dose irradiation effects on living cells. Using a droplet microdispenser, an 8 {mu}m thick polypropylene cell substrate, to which cells do not naturally adhere, was coated in a matrix pattern with the cell adhesive mussel protein Cell-Tak. Cells were shown to adhere and grow on the protein-coated spots, but not on the uncoated parts, providing for guided cell growth. Cultivation of isolated cell colonies provides an opportunity to study how low doses of ionizing radiation affect neighbouring un-irradiated cell colonies.

  6. Planning and Optimization of AGV Jobs by Petri Net and Genetic Algorithm

    Directory of Open Access Journals (Sweden)

    Anita Gudelj

    2012-12-01

    Full Text Available The following article presents the possibilities of job optimization on a maritime container terminal, in order to increase the system productivity and optimize the terminal capacity. Automated guided vehicles (AGVs are now becoming popular mode of container transport in seaport terminals. The moving of vehicles can be described as the set of discrete events and states. Some of these states can be undesirable such as conflicts and deadlocks. It is necessary to apply adequate control policy to avoid deadlocks and block the vehicles’ moving only in the case of dangerous situation.This paper addresses the use a Petri net as modeling and scheduling tool in this context. The aim of AGV scheduling is to dispatch a set of AGVs to improve the productivity of a system and reduce delay in a batch of pickup/drop-off jobs under certain constraints such as deadlines, priority, etc. The final goals are related to optimization of processing time and minimization of the number of AGVs involved while maintaining the system throughput.To find better solutions, the authors propose the integration MRF1 class of Petri net (MRF1PN with a genetic algorithm. Also, the use of a matrix based formal method is proposed to analyze discrete event dynamic system (DEDS. The algorithm is described to deal with multi-project, multi-constrained scheduling problem with shared resources. The developed model was tested and validated by simulation of typical scenarios of the container terminal of Port Koper. Modularity and simplicity of the approach allow using the model to monitor and test the efficiency of the processes, and also to propose future alternative solutions to optimize the schedule of operations and the employment of AGV at the terminal.

  7. Audit process using Petri net%借助Petri网进行流程审计

    Institute of Scientific and Technical Information of China (English)

    胡记兵; 黄作明; 柳巧玲

    2012-01-01

    The users of information tend to pay attention to information saved in storage media and omit programs which deal with information. Due to that there is more than one operation entry for information saved in storage media, even if program which deal with information truly reflect business process, it is hard to ensure that the information obtained by user of information is cor- rect. In other words, there exists external interference for programs which access data. This paper introduces function of audit table in database to help information system auditor identify whether established business process is abided by in the formation process of data in information system. Because Petri net is a powerful tool for describing process, it is necessary to introduce Petri net to au- dit complex process.%信息的使用者往往关注保存在介质上的信息而忽视处理信息的程序。由于保存在介质上的信息有多个操作入口,即使处理信息的程序真实地反映了组织的业务流程,也难保证信息使用者所获得的信息是正确的,也就是说对于访问数据的程序,存在外部干扰。引入数据库中的审计表功能,协助信息系统审计人员识别信息系统中数据的形成是否遵循了既定的业务流程。由于Petri网是描述流程的有力工具,对于复杂的业务流程,引入Petri网对流程进行审计是必要的。

  8. Interactions between IGFBP-3 and Nuclear Receptors in Prostate Cancer Apoptosis

    Science.gov (United States)

    2008-01-01

    night at 4C with primary anti-Nur77 antibody (1:100). The sections were then processed using standard avidin –biotin immunohistochemistry techniques...day-old fertilized white Leghorn eggs were cracked, and chicken embryos with intact yolks were carefully placed in 20 100mm plastic Petri dishes

  9. Undesirable dispersal of eggs and early-stage nymphs of the bed bug Hemiptera: cimicidae) by static electricity and air currents

    Science.gov (United States)

    Movement of whole live insects or other small arthropods attributed to static electricity has been reported only rarely. While viewing bed bugs in plastic or glass Petri dishes using a dissecting microscope, individual eggs and early stage nymphs were occasionally observed to move suddenly and rapid...

  10. Immobilization of sericin molecules via amorphous carbon plasma modified-polystyrene dish for serum-free culture

    Energy Technology Data Exchange (ETDEWEB)

    Tunma, Somruthai [The Graduate School, Chiang Mai University, 239 Huay Kaew Road, Muang District, Chiang Mai 50200 (Thailand); Thailand Center of Excellence in Physics (ThEP), 239 Huay Kaew Road, Muang District, Chiang Mai 50200 (Thailand); Song, Doo-Hoon [Research Center for Orofacial Hard Tissue Regeneration, College of Dentistry, Yonsei University, 50 Yonsei-ro, Seodaemun-gu, Seoul 120-752 (Korea, Republic of); Kim, Si-Eun; Kim, Kyoung-Nam [Research Center for Orofacial Hard Tissue Regeneration, College of Dentistry, Yonsei University, 50 Yonsei-ro, Seodaemun-gu, Seoul 120-752 (Korea, Republic of); Department and Research Institute of Dental Biomaterials and Bioengineering, College of Dentistry, Yonsei University, 50 Yonsei-ro, Seodaemun-gu, Seoul 120-752 (Korea, Republic of); Han, Jeon-Geon [Center for Advanced Plasma Surface Technology, Sungkyunkwan University, 300 Chunchun-dong, Jangan-gu, Suwon 440-746 (Korea, Republic of); Boonyawan, Dheerawan, E-mail: dheerawan.b@cmu.ac.th [Thailand Center of Excellence in Physics (ThEP), 239 Huay Kaew Road, Muang District, Chiang Mai 50200 (Thailand); Department of Physics and Materials Science, Faculty of Science, Chiang Mai University, 239 Huay Kaew Road, Muang District, Chiang Mai 50200 (Thailand)

    2013-10-15

    In this study, we focused on sericin hydrolysates, originating from silkworm used in serum-free human bone marrow-derived mesenchymal stem cells (hBM-MSCs) culture. We reported the effect of a covalent linkage between a bioactive protein molecule and polystyrene dish surface via a carbon intermediate layer which can slow down the release rate of protein compounds into the phosphate buffer saline (PBS) solution. Films of amorphous carbon (a-C) and functionalized-carbon were deposited on PS culture dish surfaces by using a DC magnetron sputtering system and RF PECVD system. We found that a-C based-films can increase the hydrophilicity and biocompatibility of polystyrene (PS) dishes, especially a-C films and a-C:N{sub 2} films showed good attachment of hBM-MSCs at 24 h. However, in the case of silica surface (a-C:SiO{sub x} films), the cells showed a ragged and unattached boundary resulting from the presence of surface silanol groups. For the UV–vis absorbance, all carbon modified-PS dishes showed a lower release rate of sericin molecules into PBS solution than PS control. This revealed that the functionalized carbon could be enhanced by specific binding properties with given molecules. The carbon-coated PS dishes grafting with sericin protein were used in a serum-free condition. We also found that hBM-MSCs have higher percentage of proliferated cells at day 7 for the modified dishes with carbon films and coated with sericin than the PS control coated with sericin. The physical film properties were measured by atomic force microscopy (AFM), scanning electron microscope (SEM) and contact angle measurement. The presence of -NH{sub 2} groups of sericin compounds on the PS dish was revealed by Fourier transform infrared spectroscopy (FTIR). The stability of covalent bonds of sericin molecules after washing out ungrafted sericin was confirmed by X-ray photoelectron spectroscopy (XPS).

  11. 基于Petri网的井下煤仓可靠性分析%Analysis of Bunker Reliability Based on Petri Nets

    Institute of Scientific and Technical Information of China (English)

    王毅; 刘志河; 李剑刚

    2001-01-01

    采用Petri网原理,针对矿井运输系统中柔性部件——煤仓,建立其Petri网模型,并通过随机过程理论计算了煤仓的有效度,从而给出了计算煤仓有效度的一个新的方法。%Petri nets is a new way in calculating bunker availability. The author designs petri nets model and analyses reliability of flexible units (i.e bunker) of mining transport system.Petri nets model with reliability theory model is presented.

  12. Recycling of Plastic

    DEFF Research Database (Denmark)

    Christensen, Thomas Højlund; Fruergaard, Thilde

    2011-01-01

    Plastic is produced from fossil oil. Plastic is used for many different products. Some plastic products like, for example, wrapping foil, bags and disposable containers for food and beverage have very short lifetimes and thus constitute a major fraction of most waste. Other plastic products like......, for example, gutters, window frames, car parts and transportation boxes have long lifetimes and thus appear as waste only many years after they have been introduced on the market. Plastic is constantly being used for new products because of its attractive material properties: relatively cheap, easy to form......, good strength and long durability. Recycling of plastic waste from production is well-established, while recycling of postconsumer plastic waste still is in its infancy. This chapter describes briefly how plastic is produced and how waste plastic is recycled in the industry. Quality requirements...

  13. Study on management system model for approach based on Petri net%基于 Petri 网的进近操作管理模型研究

    Institute of Scientific and Technical Information of China (English)

    罗婷婷; 孙瑞山

    2013-01-01

    According to the accidents or incidents all around the world , during the approach period , the crew afford most conscious but less time , more complicated situations and tasks .So the approach period could be the most dan-gerous one that we must pay more attention on it .More than a half accidents or incidents have happened when the ILS has failure .A manage system was put forward based on Petri net and >.The relevant accident cause factors were statistically analyzed , and the various risks were calcaluted, then the satas were feedback to the manage system to train and manage the crew .%据世界民航所发生的飞行事故情况看,进近着陆阶段时间短、任务重、环境复杂,是飞行事故多发阶段,占很大的比重,因此进近着陆是保证飞行安全的重要阶段。大多数事故是发生在仪表着陆系统出现故障的非精密进近方式。以机组非精密进近的主要飞行操作为基础建立基于Pe-tri网的事故致因模型,统计分析相关的致因因素,计算相关风险值,通过对数据的分析反馈,形成对相应飞行员的针对性学习及训练的系统性管理模式。

  14. Scientific Opinion on the pest categorisation of Plenodomus tracheiphilus (Petri Gruyter, Aveskamp & Verkley [syn. Phoma tracheiphila (Petri L.A. Kantschaveli & Gikashvili

    Directory of Open Access Journals (Sweden)

    EFSA Panel on Plant Health (PLH

    2014-07-01

    Full Text Available The European Commission requested the EFSA Panel on Plant Health to perform a pest categorisation of Phoma tracheiphila, the fungal pathogen responsible for “mal secco” disease of citrus. This pathogen is listed in Annex IIAII of Directive 2000/29/EC. Recently, the pathogen has been reclassified as Plenodomus tracheiphilus (Petri Gruyter, Aveskamp & Verkley, based on molecular phylogenetic analysis. Plenodomus tracheiphilus is a single taxonomic entity, and sensitive and specific methods are available for its differentiation from other related Plenodomus species. The main host is lemon (Citrus limon L., but the pathogen has also been reported on other species of the genera Citrus, Fortunella, Poncirus and Severinia and on their hybrids. Host plants are widely grown in the southern EU Member States (MSs and climatic conditions are conducive to disease development in both orchards and nurseries. The pathogen is present in part of the risk assessment area, being mainly reported on lemon grown in Italy, Greece, Cyprus and France, where it has a serious impact on the citrus industry. There are no obvious ecological/climatic factors limiting the potential establishment and spread of the pathogen in the, so far, non-infested citrus-producing EU MSs (i.e. Spain, Portugal, Malta and Croatia. Short-distance spread of the pathogen occurs via water splash and wind-driven rain, whereas movement of infected host plants for planting, particularly asymptomatic plants, is considered to be responsible for the introduction of the pathogen into new areas. Cultural practices and copper-based fungicide sprays may reduce inoculum sources and prevent new infections but they cannot eliminate the pathogen. P. tracheiphilus fulfils all of the pest categorisation criteria for having the potential to be a quarantine pest and a regulated non-quarantine pest, as those are defined in the International Standards for Phytosanitary Measures No 11 and 21, respectively.

  15. Validation of a Dish-Based Semiquantitative Food Questionnaire in Rural Bangladesh

    Directory of Open Access Journals (Sweden)

    Pi-I. D. Lin

    2017-01-01

    Full Text Available A locally validated tool was needed to evaluate long-term dietary intake in rural Bangladesh. We assessed the validity of a 42-item dish-based semi-quantitative food frequency questionnaire (FFQ using two 3-day food diaries (FDs. We selected a random subset of 47 families (190 participants from a longitudinal arsenic biomonitoring study in Bangladesh to administer the FFQ. Two 3-day FDs were completed by the female head of the households and we used an adult male equivalent method to estimate the FD for the other participants. Food and nutrient intakes measured by FFQ and FD were compared using Pearson’s and Spearman’s correlation, paired t-test, percent difference, cross-classification, weighted Kappa, and Bland–Altman analysis. Results showed good validity for total energy intake (paired t-test, p < 0.05; percent difference <10%, with no presence of proportional bias (Bland–Altman correlation, p > 0.05. After energy-adjustment and de-attenuation for within-person variation, macronutrient intakes had excellent correlations ranging from 0.55 to 0.70. Validity for micronutrients was mixed. High intraclass correlation coefficients (ICCs were found for most nutrients between the two seasons, except vitamin A. This dish-based FFQ provided adequate validity to assess and rank long-term dietary intake in rural Bangladesh for most food groups and nutrients, and should be useful for studying dietary-disease relationships.

  16. [Dysphagia caused by neurogenic deglutition disorders and diffuse idiopathic skeletal hyperostosis (DISH)].

    Science.gov (United States)

    Bremke, M; Wagner, H-J; Folz, B J

    2006-09-01

    Diffuse idiopathic skeletal hyperostosis (DISH) may lead to dysphagia caused by osteophytes of the cervical spine. Osteophytes can be resected transorally or transcervically, but operative ablation should not be indicated generously because of the threat of severe complications. A fifty-year-old man with dysphagia and loss of weight of 15 kg in the last three months is presented. He also suffered from a brain damage during infancy which caused grand-mal-seizures. One seizure lead to cardiac arrest which required cardio-pulmonary resuscitation and subsequent tracheostomy. A spheric tumor of the posterior pharyngeal wall could be seen endoscopically, it appeared radiologically as an osteophytic formation of the segments C (3) - C (5). Ossification of the anterior longitudinal ligament was also seen. Diagnosis of DISH was made on the basis of these results. Contrast imaging of the esophagus and videofluoroscopy showed aspiration in terms of neurogenic disorders. The patient received a percutaneous gastrostomy after his case was discussed with neurologic and orthopaedic colleagues, because a causal therapy of the combined disease seemed to be impossible. Dysphagia in the presented case was caused by a combination of neurogenic deglutition disorders and oropharyngeal obstruction through osteophytes. Surgical removal of the osteophytes was not indicated because it would have put the patient at a certain risk, but only a part of the underlying problem would have been removed. Symptomatic therapy with a gastrostomy secures normocaloric diet. The patient's weight remained stable and he can follow his habitual daily routine.

  17. Operational data and thermodynamic modeling of a Stirling-dish demonstration installation in desert conditions

    Science.gov (United States)

    Nilsson, Martin; Jamot, Jakob; Malm, Tommy

    2017-06-01

    To field test its Stirling-dish unit, Cleanergy AB of Sweden in Q1 2015 built a ten unit demo park in Dubai. The first STE (Solar Thermal Energy) generation of its Stirling genset, the C11S, had at its core an 11 kWel Stirling engine/generator combination. The genset was mated with a parabolic concentrator developed for the genset by a supplier. Local weather conditions in Dubai provide opportunities to test performance in an environment with high insolation and high ambient temperature. In addition, the conditions in Dubai are windy, salty, humid and dusty, historically challenging for solar technologies [1]. In Q1 2016 one of the C11S Stirling-dish units was replaced by the first prototype of Cleanergy's second generation Stirling genset, the Sunbox, and an in-house developed parabolic concentrator. Operational data from field testing during the spring of 2016 are presented and discussed and show the large performance improvement achieved with the Sunbox unit.

  18. Reflux heat-pipe solar receivers for dish-electric systems

    Science.gov (United States)

    Andraka, Charles E.; Diver, Richard B.

    1988-04-01

    The feasibility of competitive, modular bulk electric power from the sun may be greatly enhanced by the use of a reflux heat pipe receiver to combine a heat engine with a paraboloidal dish concentrator. This combination represents a potential improvement over previous successful demonstrations of dish-electric technology in terms of enhanced performance, lower cost, longer life, and greater flexibility in engine design. In the reflux (i.e., gravity assisted) heat pipe receiver, concentrated solar radiation causes liquid metal (sodium, potassium, or NaK) to evaporate. The vapor flows to the engine interface heat exchanger, where it condenses and releases the latent heat. The condensate is returned to the receiver absorber by gravity (refluxing), and distributed over the surface by gravity and/or capillary forces in a wick lining the receiver. It is essentially an adaptation of heat pipe technology to the peculiar requirements of concentrated solar flux, and provides many advantages over conventional heated tub receiver technology. This overview paper describes the current status and future plans for the U.S. Solar Thermal Program reflux receiver development program at Sandia National Laboratories. Current work includes conventional mesh wick receivers, sintered metal wicks, and pool boiler receivers. The relative design merits and concerns of the different approaches and technology development test plans are discussed.

  19. Embryo density may affect embryo quality during in vitro culture in a microwell group culture dish.

    Science.gov (United States)

    Lehner, Adam; Kaszas, Zita; Murber, Akos; Rigo, Janos; Urbancsek, Janos; Fancsovits, Peter

    2017-08-01

    Culturing embryos in groups is a common practice in mammalian embryology. Since the introduction of different microwell dishes, it is possible to identify oocytes or embryos individually. As embryo density (embryo-to-volume ratio) may affect the development and viability of the embryos, the purpose of this study was to assess the effect of different embryo densities on embryo quality. Data of 1337 embryos from 228 in vitro fertilization treatment cycles were retrospectively analyzed. Embryos were cultured in a 25 μl microdrop in a microwell group culture dish containing 9 microwells. Three density groups were defined: Group 1 with 2-4 (6.3-12.5 μl/embryo), Group 2 with 5-6 (4.2-5.0 μl/embryo), and Group 3 with 7-9 (2.8-3.6 μl/embryo) embryos. Proportion of good quality embryos was higher in Group 2 on both days (D2: 18.9 vs. 31.5 vs. 24.7%; p Culturing 5-6 embryos together in a culture volume of 25 μl may benefit embryo quality. As low egg number, position, and distance of the embryos may influence embryo quality, results should be interpreted with caution.

  20. Sensory attributes of dishes containing shrimp paste with different concentrations of glutamate and 5'-nucleotides.

    Science.gov (United States)

    Jinap, S; Ilya-Nur, A R; Tang, S C; Hajeb, P; Shahrim, K; Khairunnisak, M

    2010-10-01

    The shrimp paste called belacan is a traditional umami taste condiment extensively used in Malaysia that is rich in glutamate and 5'-nucleotides. The aim of this study was to determine the concentration of glutamate and 5'-nucleotides of various types of foods prepared with belacan and to measure their sensory attributes. The concentration of free glutamic acid found in different brands of belacan was 180-530mg/100g and in local dishes 601-4207mg/100g. The total amount of 5'-nucleotides in belacan samples ranged from 0.85 to 42.25μg/g. A Quantitative Descriptive Analysis (QDA) using a list of 17 sensory attributes showed a good correlation between belacan concentration in the final food and a range of positive sensory attributes, except for bitter, sweet, sour taste and astringency. Belacan also contains bitter, sweet and sour compounds that change the positive attributes of belacan at higher concentrations. The highest aroma attributes were linked to nasi goreng belacan (belacan fried rice) while the highest flavour attributes were found in sambal belacan. There was a 32 folds significant increase of umami attributes with the addition of belacan to final foods. The optimum amount of belacan was 0.45% for asam pedas (tamarind flavoured dish with belacan), 18% for sambal belacan (chilli belacan), 1.5-2.5% for kangkong goreng belacan (stir fried water convolous with belacan), and 2% for nasi goreng belacan.

  1. Analysis of solar water heater with parabolic dish concentrator and conical absorber

    Science.gov (United States)

    Rajamohan, G.; Kumar, P.; Anwar, M.; Mohanraj, T.

    2017-06-01

    This research focuses on developing novel technique for a solar water heating system. The novel solar system comprises a parabolic dish concentrator, conical absorber and water heater. In this system, the conical absorber tube directly absorbs solar radiation from the sun and the parabolic dish concentrator reflects the solar radiations towards the conical absorber tube from all directions, therefore both radiations would significantly improve the thermal collector efficiency. The working fluid water is stored at the bottom of the absorber tubes. The absorber tubes get heated and increases the temperature of the working fluid inside of the absorber tube and causes the working fluid to partially evaporate. The partially vaporized working fluid moves in the upward direction due to buoyancy effect and enters the heat exchanger. When fresh water passes through the heat exchanger, temperature of the vapour decreases through heat exchange. This leads to condensation of the vapour and forms liquid phase. The working fluid returns to the bottom of the collector absorber tube by gravity. Hence, this will continue as a cyclic process inside the system. The proposed investigation shows an improvement of collector efficiency, enhanced heat transfer and a quality water heating system.

  2. CPV semi-dense array design for dish and tower collectors

    Science.gov (United States)

    Hayden, Herb; Thomas, Paul; Fette, Nicholas; Farkas, Zoltan; Bading, Michael; Stone, Bradley; Miner, Mark; Stickroth, Oliver; Bagewadi, Nakul; Romero, Memo; Sonuparlak, Birol; Eichholz, Rainer; Ziegler, Michael; Pawlowski, Edgar

    2012-10-01

    SST is developing a new Dish CPV dense array system that overcomes the flux uniformity requirement of previous designs. The ability to operate without flux uniformity relaxes the precision requirements of primary collector optics and eliminates homogenizing optics previously required for dense array CPV. Array design can be configured for dish and tower/heliostat systems developed for thermal CSP applications. The design uses industry standard CPV cells and manufacturing materials and methods for minimum cost and high reliability. Nominal input flux to the array for full power is about 250 suns. Internal array optics increase flux to the cells to about 1200 suns. Linear optics provide additional concentration, permit novel use of commercial glass production methods and facilitate power collection design that is integrated with dynamic power conversion and maximum power point tracking (MPPT). Efficient power hybrid packaging methods are used along with advanced liquid cooling "cold-plate" thermal management. Byproduct "waste heat" can be provided for on-site CHP use. We report on the design approach and status of development with the beginning of on-sun alpha testing of the first of 50 kW of CPV modules being produced.

  3. Detailed Performance Analysis of the 10-Kw CNRS-Promes Dish/Stirling System

    Energy Technology Data Exchange (ETDEWEB)

    Reinalter, W.; Ulmer, S.; Heller, P.; Rauch, T.; Gineste, J. M.; Ferriere, A.; Nepveu, F.

    2006-07-01

    The CNRS-Promes dish/Stirling system was erected in June 2004 as the last of three country reference units built in the Envirodish project, partly financed by the German ministry of environment. It represents the latest development step of the EuroDish system with many improved components. With a measured peak of 11 kW electrical output power it is also the best performing system so far. The measurement campaign to determine the optical and thermodynamic efficiency of the system is presented. The optical quality of the concentrator and the energy input to the power conversion unit was measured with a classical flux-mapping system using a Lambertian target and a CCD camera system. For the thermodynamic analysis all the data necessary for a complete energy balance around the Stirling engine, i.e. efficiency of the Stirling motor, the cavity and the receiver as well as the parasitic losses were measured or approximated by calculations. Such a detailed performance analysis helps to quantify all significant losses of the system and to identify the most rewarding future improvements. (Author)

  4. Design, simulation and optimization of a solar dish collector with spiral-coil thermal absorber

    Directory of Open Access Journals (Sweden)

    Pavlović Saša R.

    2016-01-01

    Full Text Available The efficient conversion of solar radiation into heat at high temperature levels requires the use of concentrating solar collectors. The goal of this paper is to present the optical and the thermal analysis of a parabolic dish concentrator with a spiral coil receiver. The parabolic dish reflector consists of 11 curvilinear trapezoidal reflective petals constructed by PMMA with silvered mirror layer and has a diameter of 3.8 m, while its focal distance is 2.26m. This collector is designed with commercial software SolidWorks and simulated, optically and thermally in its Flow Simulation Studio. The optical analysis proved that the ideal position of the absorber is at 2.1m from the reflector in order to maximize the optical efficiency and to create a relative uniform heat flux over the absorber. In thermal part of the analysis, the energetic efficiency was calculated approximately 65%, while the exergetic efficiency is varied from 4% to 15% according to the water inlet temperature. Moreover, other important parameters as the heat flux and temperature distribution over the absorber are presented. The pressure drop of the absorber coil is calculated at 0.07bar, an acceptable value.

  5. Large Parabolic Dish collectors with small gas-turbine, Stirling engine or photovoltaic power conversion systems

    Energy Technology Data Exchange (ETDEWEB)

    Gehlisch, K.; Heikal, H.; Mobarak, A.; Simon, M.

    1982-08-01

    A comparison for different solar thermal power plants is presented and demonstrates that the large parabolic dish in association with a gas turbine or a Sterling engine could be a competitive system design in the net power range of 50-1000KW. The important advantages of the Large Parabolic Dish concept compared to the Farm and Tower concept are discussed: concentration ratios up to 5000 and uniform heat flux distribution throughout the day which allow very high receiver temperatures and therefor high receiver efficiency to operate effectively Stirling motors or small gas turbines in the mentioned power range with an overall efficiency of 20 to 30%. The high focal plane concentration leads to the efficient use of ceramic materials for receivers of the next generation, applicable in temperature ranges up to 1,300 /sup 0/C for energy converters. Besides the production of electricity, the system can supply process heat in the temperature range of 100 to 400 /sup 0/C as waste heat from the gas turbo converter and heat at temperature levels from 500 to 900 /sup 0/C (1300 /sup 0/C) directly out of the receiver.

  6. Performance tests and efficiency analysis of Solar Invictus 53S - A parabolic dish solar collector for direct steam generation

    Science.gov (United States)

    Jamil, Umer; Ali, Wajahat

    2016-05-01

    This paper presents the results of performance tests conducted on Solar Invictus 53S `system'; an economically effective solar steam generation solution designed and developed by ZED Solar Ltd. The system consists of a dual axis tracking parabolic solar dish and bespoke cavity type receiver, which works as a Once Through Solar Steam Generator `OTSSG' mounted at the focal point of the dish. The overall performance and efficiency of the system depends primarily on the optical efficiency of the solar dish and thermal efficiency of the OTSSG. Optical testing performed include `on sun' tests using CCD camera images and `burn plate' testing to evaluate the sunspot for size and quality. The intercept factor was calculated using a colour look-back method to determine the percentage of solar rays focused into the receiver. Solar dish tracking stability tests were carried out at different times of day to account for varying dish elevation angles and positions, movement of the sunspot centroid was recorded and logged using a CCD camera. Finally the overall performance and net solar to steam efficiency of the system was calculated by experimentally measuring the output steam parameters at varying Direct Normal Insolation (DNI) levels at ZED Solar's test facility in Lahore, Pakistan. Thermal losses from OTSSG were calculated using the known optical efficiency and measured changes in output steam enthalpy.

  7. 77 FR 54930 - Carlyle Plastics and Resins, Formerly Known as Fortis Plastics, A Subsidiary of Plastics...

    Science.gov (United States)

    2012-09-06

    ... Employment and Training Administration Carlyle Plastics and Resins, Formerly Known as Fortis Plastics, A... plastic parts. New information shows that Fortis Plastics is now called Carlyle Plastics and Resins. In... of Carlyle Plastics and Resins, formerly known as Fortis Plastics, a subsidiary of...

  8. Modeling and performance analysis of a closed-loop supply chain using first-order hybrid Petri nets

    Directory of Open Access Journals (Sweden)

    Imane Outmal

    2016-05-01

    Full Text Available Green or closed-loop supply chain had been the focus of many manufacturers during the last decade. The application of closed-loop supply chain in today’s manufacturing is not only due to growing environmental concerns and the recognition of its benefits in reducing greenhouse gas emissions, energy consumption, and meeting a more strict environmental regulations but it also offers economic competitive advantages if appropriately managed. First-order hybrid Petri nets represent a powerful graphical and mathematical formalism to map and analyze the dynamics of complex systems such as closed-loop supply chain networks. This article aims at illustrating the use of first-order hybrid Petri nets to model a closed-loop supply chain network and evaluate its operational, financial, and environmental performance measures under different management policies. Actual data from auto manufacturer in the United States are used to validate network’s performance under both tactical and strategic decision-making, namely, (1 tactical decision—production policies: increase of recovered versus new components and (2 strategic decision—closed-loop supply chain network structure: manufacturer internal recovery process or recovery process done by a third-party collection and recovery center. The work presented in this article is an extension of the use of first-order hybrid Petri nets as a modeling and performance analysis tool from supply chain to closed-loop supply chain. The modularity property of first-order hybrid Petri nets has been used in the modeling process, and the simulation and analysis of the modeled network are done in MATLAB® environment. The results of the experiments depict that first-order hybrid Petri nets are a powerful modeling and analysis formalism for closed-loop supply chain networks and can be further used as an efficient decision-making tool at both tactical and strategic levels. Unlike other researches on modeling supply chain

  9. Our plastic age

    National Research Council Canada - National Science Library

    Richard C. Thompson; Shanna H. Swan; Charles J. Moore; Frederick S. vom Saal

    2009-01-01

    Within the last few decades, plastics have revolutionized our daily lives. Globally we use in excess of 260 million tonnes of plastic per annum, accounting for approximately 8 per cent of world oil production...

  10. Weinig plastic in vissenmaag

    NARCIS (Netherlands)

    Foekema, E.M.

    2012-01-01

    Waar de magen van sommige zeevogels vol plastic zitten, lijken vissen in de Noordzee nauwelijks last te hebben van kunststofafval. Onderzoekers die plastic resten zochten in vissenmagen vonden ze in elk geval nauwelijks.

  11. Ear Plastic Surgery

    Science.gov (United States)

    ... ENTCareers Marketplace Find an ENT Doctor Near You Ear Plastic Surgery Ear Plastic Surgery Patient Health Information ... they may improve appearance and self-confidence. Can Ear Deformities Be Corrected? Formation of the ear during ...

  12. Manager- bändikarjääri disainija ja kokkusõlmija / Paul Cheeetham, Tapio Korjus, Petri H. Lunden ...[jt.

    Index Scriptorium Estoniae

    Cheetham, Paul

    2010-01-01

    Muusikamanageride Paul Cheethami, Tapio Korjuse, Petri H. Lundeni, Kari Pössi ja Rasmus Stolbergi arvamusi oma tööst ja nõuannetest eesti ansamblitele, kes tahavad oma karjääri teha rahvusvahelisel areenil

  13. Manager- bändikarjääri disainija ja kokkusõlmija / Paul Cheeetham, Tapio Korjus, Petri H. Lunden ...[jt.

    Index Scriptorium Estoniae

    Cheetham, Paul

    2010-01-01

    Muusikamanageride Paul Cheethami, Tapio Korjuse, Petri H. Lundeni, Kari Pössi ja Rasmus Stolbergi arvamusi oma tööst ja nõuannetest eesti ansamblitele, kes tahavad oma karjääri teha rahvusvahelisel areenil

  14. Biodegradability of Plastics

    OpenAIRE

    Yutaka Tokiwa; Calabia, Buenaventurada P.; Charles U. Ugwu; Seiichi Aiba

    2009-01-01

    Plastic is a broad name given to different polymers with high molecular weight, which can be degraded by various processes. However, considering their abundance in the environment and their specificity in attacking plastics, biodegradation of plastics by microorganisms and enzymes seems to be the most effective process. When plastics are used as substrates for microorganisms, evaluation of their biodegradability should not only be based on their chemical structure, but also on their physical ...

  15. [The consumption of dishes and/or fishy snacks by school youth from Miedzychodzko-Sierakowskie lakes].

    Science.gov (United States)

    Bortnowska, Grazyna; Grotowska, Longina; Goluch-Koniuszy, Zuzanna

    2011-01-01

    The school youth inhabiting Miedzychodzko-Sierakowskie lakes consumed dishes and/or fishy snacks on the similar low level as their peers in other regions of country, mainly breaded fried fishes and partly or highly manufactured products i.e., herrings in sour cream as well as pastes from smoked fishes and canned fishes. Relatively high ranks in rows of preference (liking) and frequency intake were found for carp, herring and cheap cultured panga from import. The presence of bones and specific odour were the factors that mostly affected low consumption of dishes and/or snacks from fishes. It seems that preparation of attractive tasty dishes and/or snacks from fresh fishes could help in youth teaching regarding correct nutritional habits as well as retain tradition of their consumption during adult life.

  16. Chemical Recycle of Plastics

    Directory of Open Access Journals (Sweden)

    Sara Fatima

    2014-11-01

    Full Text Available Various chemical processes currently prevalent in the chemical industry for plastics recycling have been discussed. Possible future scenarios in chemical recycling have also been discussed. Also analyzed are the effects on the environment, the risks, costs and benefits of PVC recycling. Also listed are the various types of plastics and which plastics are safe to use and which not after rcycle

  17. Plastic value chains

    DEFF Research Database (Denmark)

    Baxter, John; Wahlstrom, Margareta; Zu Castell-Rüdenhausen, Malin

    2014-01-01

    Optimizing plastic value chains is regarded as an important measure in order to increase recycling of plastics in an efficient way. This can also lead to improved awareness of the hazardous substances contained in plastic waste, and how to avoid that these substances are recycled. As an example...

  18. 基于XML的Petri网信息读写器研究%Research on Petri Information Read Write Based on XML

    Institute of Scientific and Technical Information of China (English)

    刘红玲

    2014-01-01

    作为一种优秀的系统描述与分析的形式化工具,Petri网已经广泛应用于协议分析工程领域、人工智能以及软件工程、程序验证和柔性制造系统等各个领域。由于Petri网适合用来描述并发和分布式系统,就目前来说对Petri网的研究已经取得了较成熟的理论研究成果。同时在对Petri网研究的不断深入过程中,出现了多种Petri网类型、各种Petri网工具和Petri网的文件格式,因此不同Petri网工具之间信息交换功能成为一个急需解决的重要问题。%As the formal tool system description and analysis of a good, Petri network has been widely used in protocol analysis each field of engineering field, artificial intelligence and software engineering, program verification and flexible manufacturing sys-tem. Because the Petri net is suitable to describe the concurrent and distributed system, for the present research of Petri network have been more mature theoretical research. At the same time in the deepening process of Petri network technology, a variety of the Petri net type, all kinds of Petri net and Petri net file format, so the function of information exchange between different Petri net tool has become an urgent problem to solve.

  19. Vegetable dishes, dairy products and fruits are key items mediating adequate dietary intake for Japanese adults with spinal cord injury.

    Science.gov (United States)

    Tsunoda, N; Inayama, T; Hata, K; Oka, J

    2015-11-01

    This is a cross-sectional study. The objective of this study was to ascertain the essential items mediating adequate dietary intake based on the Japanese Food Guide in common among the transtheoretical model (TTM), self-efficacy (SE) and outcome expectancy (OE). Members of the organization Spinal Injuries Japan. We posted a questionnaire survey to 2731 community-dwelling Japanese adults with spinal cord injury (SCI), and responses from 841 individuals were analyzed. Food intake was assessed as the frequency scores of 10 food items eaten in a daily diet in Japan. The correlations between the frequency scores of food intake and TTM, SE and OE were determined by binominal logistic regression analysis. The frequency scores of food intake were significantly associated with 'To eat vegetable dishes (dishes made mainly from vegetables or potatoes) not less than twice a day', 'To eat green/yellow vegetables not less than twice a day', 'To eat dairy products not less than once a day' and 'To eat fruits not less than once a day' in TTM. 'To eat vegetable dishes (dishes made mainly from vegetables or potatoes) not less than twice a day', 'To eat dairy products not less than once a day' and 'To eat fruits not less than once a day' were significantly associated with the frequency scores of food intake in SE. In OE, no differences were shown. This study finds that vegetable dishes, dairy products and fruits are the key items mediating adequate dietary intake. Dietary guidelines promoting the intake of these dishes for SCI individuals are needed.

  20. Aplicação da modelagem por redes de Petri para avaliação ocupacional de trabalhadores

    Directory of Open Access Journals (Sweden)

    Jonas Lied

    2009-07-01

    Full Text Available Este trabalho introduz a modelagem por Redes de Petri Coloridas (RPC como ferramenta para avaliação dos riscos ocupacionais de trabalhadores em uma linha de manufatura. O uso da ferramenta consiste em modelar a linha de manufatura por Redes de Petri Coloridas, simular o modelo em computador, informando a situação inicial do processo.  A partir deste ponto, com os resultados obtidos da simulação avaliar a carga de trabalho individual dos trabalhadores, permitindo verificar quais as tarefas desenvolvidas devem ser estudadas para diminuição dos riscos ocupacionais envolvidos. Foi possível verificar que alguns trabalhadores estão sobrecarregados e outros folgados na linha de montagem estudada.

  1. Abnormity control design and performance analysis of real-time data exchange software based on Petri net

    Institute of Scientific and Technical Information of China (English)

    Zhang Weimin

    2005-01-01

    In many spaceflight measure and control software systems, varieties of measure data are exchanged between different software. Qualities of measure and control software systems are influenced by the performances of data exchange software greatly. Many problems that appear during the running process of real-time measure and control software and are difficult to be located are caused by data exchange software. So, it is necessary to analyze the performances of data exchange software while designing measure and control software systems. In this article, the Petri net model of the real-time data exchange software is established first. Then the model is simplified and analyzed. The design of abnormity control for buffer overflow is given. Finally,using the Petri net method, the performances of the real-time data exchange software are analyzed and discussed.

  2. Solar-parabolic dish-Stirling-engine-system module. Task 1: Topical report, market assessment/conceptual design

    Energy Technology Data Exchange (ETDEWEB)

    1982-11-30

    The major activities reported are: a market study to identify an early market for a dish-Stirling module and assess its commercial potential; preparation of a conceptual system and subsystem design to address this market; and preparation of an early sales implementation plan. A study of the reliability of protection from the effects of walk-off, wherein the sun's image leaves the receiver if the dish is not tracking, is appended, along with an optical analysis and structural analysis. Also appended are the relationship between PURPA and solar thermal energy development and electric utility pricing rationale. (LEW)

  3. A review of test results on solar thermal power modules with dish-mounted Stirling and Brayton cycle engines

    Science.gov (United States)

    Jaffe, Leonard D.

    1988-01-01

    This paper presents results of development tests of various solar thermal parabolic dish modules and assemblies that used dish-mounted Brayton or Stirling cycle engines for production of electric power. These tests indicate that early modules achieve net efficiencies up to 29 percent in converting sunlight to electricity, as delivered to the grid. Various equipment deficiencies were observed and a number of malfunctions occurred. The performance measurements, as well as the malfunctions and other test experience, provided information that should be of value in developing systems with improved performance and reduced maintenance.

  4. Solar-parabolic dish-Stirling-engine-system module. Task 1: Topical report, market assessment/conceptual design

    Energy Technology Data Exchange (ETDEWEB)

    1982-11-30

    The major activities reported are: a market study to identify an early market for a dish-Stirling module and assess its commercial potential; preparation of a conceptual system and subsystem design to address this market; and preparation of an early sales implementation plan. A study of the reliability of protection from the effects of walk-off, wherein the sun's image leaves the receiver if the dish is not tracking, is appended, along with an optical analysis and structural analysis. Also appended are the relationship between PURPA and solar thermal energy development and electric utility pricing rationale. (LEW)

  5. Biodegradability of plastics.

    Science.gov (United States)

    Tokiwa, Yutaka; Calabia, Buenaventurada P; Ugwu, Charles U; Aiba, Seiichi

    2009-08-26

    Plastic is a broad name given to different polymers with high molecular weight, which can be degraded by various processes. However, considering their abundance in the environment and their specificity in attacking plastics, biodegradation of plastics by microorganisms and enzymes seems to be the most effective process. When plastics are used as substrates for microorganisms, evaluation of their biodegradability should not only be based on their chemical structure, but also on their physical properties (melting point, glass transition temperature, crystallinity, storage modulus etc.). In this review, microbial and enzymatic biodegradation of plastics and some factors that affect their biodegradability are discussed.

  6. Plastic value chains

    DEFF Research Database (Denmark)

    Baxter, John; Wahlstrom, Margareta; Zu Castell-Rüdenhausen, Malin

    2014-01-01

    Optimizing plastic value chains is regarded as an important measure in order to increase recycling of plastics in an efficient way. This can also lead to improved awareness of the hazardous substances contained in plastic waste, and how to avoid that these substances are recycled. As an example......, plastics from WEEE is chosen as a Nordic case study. The project aims to propose a number of improvements for this value chain together with representatives from Nordic stakeholders. Based on the experiences made, a guide for other plastic value chains shall be developed....

  7. Biodegradability of Plastics

    Directory of Open Access Journals (Sweden)

    Yutaka Tokiwa

    2009-08-01

    Full Text Available Plastic is a broad name given to different polymers with high molecular weight, which can be degraded by various processes. However, considering their abundance in the environment and their specificity in attacking plastics, biodegradation of plastics by microorganisms and enzymes seems to be the most effective process. When plastics are used as substrates for microorganisms, evaluation of their biodegradability should not only be based on their chemical structure, but also on their physical properties (melting point, glass transition temperature, crystallinity, storage modulus etc.. In this review, microbial and enzymatic biodegradation of plastics and some factors that affect their biodegradability are discussed.

  8. Journal of CHINA PLASTICS

    Institute of Scientific and Technical Information of China (English)

    2012-01-01

    Journal of CHINA PLASTICS was authorized and approved by The State Committee of Science and Technology of China and The Bureau of News Press of China, and published by The China Plastics Processing Industry Association,Beijing Technology and Business University and The Institute of Plastics Processing and Application of Light Industry, distributed worldwide. Since its birth in 1987, CHINA PLASTICS has become a leading magazine in plastics industry in China, a national Chinese core journal and journal of Chinese scientific and technological article statistics. It is covered by CA.

  9. Redes de Petri: Modelado e implementación de algoritmos para autómatas programables

    Directory of Open Access Journals (Sweden)

    Luis Diego Murillo

    2008-04-01

    Full Text Available El presente trabajo es una monografía orientada hacia la utilización del formalismo de las Redes de Petri, propuesto por Carl Petri en la descripción de Sistemas Dinámicos de Eventos Discretos (DEDS. Las Redes de Petri, cuyo acrónimo en inglés es PN, fueron utilizadas inicialmente para el análisis de algoritmos en la computación paralela o concurrente, pero dada la complejidad de los procesos productivos actuales, las PN son un método alternativo de diseño tanto para el procesoindustrial como para el controlador. En este sentido, este estudio hace una revisión de las referencias bibliográficas donde se indica cómo realizar el modelado y la implementación de algoritmos de control en Controladores Lógicos Programables (PLCs por sus siglas en inglés.

  10. A hazard analysis via an improved timed colored petri net with time-space coupling safety constraint

    Institute of Scientific and Technical Information of China (English)

    Li Zelin; Wang Shihai; Zhao Tingdi; Liu Bin

    2016-01-01

    Petri nets are graphical and mathematical tools that are applicable to many systems for modeling, simulation, and analysis. With the emergence of the concept of partitioning in time and space domains proposed in avionics application standard software interface (ARINC 653), it has become difficult to analyze time–space coupling hazards resulting from resource partitioning using classical or advanced Petri nets. In this paper, we propose a time–space coupling safety constraint and an improved timed colored Petri net with imposed time–space coupling safety constraints (TCCP-NET) to fill this requirement gap. Time–space coupling hazard analysis is conducted in three steps: specification modeling, simulation execution, and results analysis. A TCCP-NET is employed to model and analyze integrated modular avionics (IMA), a real-time, safety-critical system. The analysis results are used to verify whether there exist time–space coupling hazards at runtime. The method we propose demonstrates superior modeling of safety-critical real-time systems as it can specify resource allocations in both time and space domains. TCCP-NETs can effectively detect underlying time–space coupling hazards.

  11. A hazard analysis via an improved timed colored petri net with time–space coupling safety constraint

    Directory of Open Access Journals (Sweden)

    Li Zelin

    2016-08-01

    Full Text Available Petri nets are graphical and mathematical tools that are applicable to many systems for modeling, simulation, and analysis. With the emergence of the concept of partitioning in time and space domains proposed in avionics application standard software interface (ARINC 653, it has become difficult to analyze time–space coupling hazards resulting from resource partitioning using classical or advanced Petri nets. In this paper, we propose a time–space coupling safety constraint and an improved timed colored Petri net with imposed time–space coupling safety constraints (TCCP-NET to fill this requirement gap. Time–space coupling hazard analysis is conducted in three steps: specification modeling, simulation execution, and results analysis. A TCCP-NET is employed to model and analyze integrated modular avionics (IMA, a real-time, safety-critical system. The analysis results are used to verify whether there exist time–space coupling hazards at runtime. The method we propose demonstrates superior modeling of safety-critical real-time systems as it can specify resource allocations in both time and space domains. TCCP-NETs can effectively detect underlying time–space coupling hazards.

  12. Reconstruction of extended Petri nets from time series data and its application to signal transduction and to gene regulatory networks

    Directory of Open Access Journals (Sweden)

    Marwan Wolfgang

    2011-07-01

    Full Text Available Abstract Background Network inference methods reconstruct mathematical models of molecular or genetic networks directly from experimental data sets. We have previously reported a mathematical method which is exclusively data-driven, does not involve any heuristic decisions within the reconstruction process, and deliveres all possible alternative minimal networks in terms of simple place/transition Petri nets that are consistent with a given discrete time series data set. Results We fundamentally extended the previously published algorithm to consider catalysis and inhibition of the reactions that occur in the underlying network. The results of the reconstruction algorithm are encoded in the form of an extended Petri net involving control arcs. This allows the consideration of processes involving mass flow and/or regulatory interactions. As a non-trivial test case, the phosphate regulatory network of enterobacteria was reconstructed using in silico-generated time-series data sets on wild-type and in silico mutants. Conclusions The new exact algorithm reconstructs extended Petri nets from time series data sets by finding all alternative minimal networks that are consistent with the data. It suggested alternative molecular mechanisms for certain reactions in the network. The algorithm is useful to combine data from wild-type and mutant cells and may potentially integrate physiological, biochemical, pharmacological, and genetic data in the form of a single model.

  13. A Timed Colored Petri Net Simulation-Based Self-Adaptive Collaboration Method for Production-Logistics Systems

    Directory of Open Access Journals (Sweden)

    Zhengang Guo

    2017-03-01

    Full Text Available Complex and customized manufacturing requires a high level of collaboration between production and logistics in a flexible production system. With the widespread use of Internet of Things technology in manufacturing, a great amount of real-time and multi-source manufacturing data and logistics data is created, that can be used to perform production-logistics collaboration. To solve the aforementioned problems, this paper proposes a timed colored Petri net simulation-based self-adaptive collaboration method for Internet of Things-enabled production-logistics systems. The method combines the schedule of token sequences in the timed colored Petri net with real-time status of key production and logistics equipment. The key equipment is made ‘smart’ to actively publish or request logistics tasks. An integrated framework based on a cloud service platform is introduced to provide the basis for self-adaptive collaboration of production-logistics systems. A simulation experiment is conducted by using colored Petri nets (CPN Tools to validate the performance and applicability of the proposed method. Computational experiments demonstrate that the proposed method outperforms the event-driven method in terms of reductions of waiting time, makespan, and electricity consumption. This proposed method is also applicable to other manufacturing systems to implement production-logistics collaboration.

  14. O potencial das redes de Petri em modelagem e análise de processos de negócio The potencial of Petri nets in modeling and analysis of workflow

    Directory of Open Access Journals (Sweden)

    Sílvia Inês Dallavalle de Pádua

    2004-04-01

    Full Text Available A tecnologia de gerenciamento workflow procura oferecer uma solução flexível em apoio aos processos de negócios, por meio da facilitação de modificações e da criação de novos processos. Entretanto, a falta de definição bem formalizada no que se refere à sintaxe e à semântica de tais técnicas dificulta análises mais complexas dos modelos. Nesse caso, redes de Petri atuam com excelente potencial, uma vez que possuem representação gráfica, são de fácil aprendizado, funcionam como linguagem de comunicação entre especialistas de diversas áreas, possibilitam descrever aspectos estáticos e dinâmicos do sistema a ser representado e ainda possuem o formalismo matemático necessário para métodos de análise já consagrados. O presente trabalho tem por objetivo, primeiramente, oferecer uma visão atualizada do estado da arte na área de modelagem de workflow baseada em redes de Petri e expor um exemplo de modelo de workflow com parâmetros de tempo e custo associados às transições da rede. O objetivo secundário é apresentar conceitos importantes de redes de Petri, workflow e rotas de processos.Unfortunately these systems and techniques do not have well-defined syntax and semantic, which makes harder the complex analysis of models. In this case, Petri nets have excellent potential to solve the problem, once they present graphic representation and easy understanding. They are used as a communication language among expert people in different areas, and may allow the description of static and dynamic aspects of the systems that have to be represented. Also, they have mathematic formalism, which make possibly the use of the analysis methods. The objective of this work is to present the potential of Petri nets in studies of Enterprise Modelling and Workflow, showing an example of application, with time and cost parameters.

  15. Challenges in plastics recycling

    DEFF Research Database (Denmark)

    Pivnenko, Kostyantyn; Jakobsen, L. G.; Eriksen, Marie Kampmann

    2015-01-01

    Recycling of waste plastics still remains a challenging area in the waste management sector. The current and potential goals proposed on EU or regional levels are difficult to achieve, and even to partially fullfil them the improvements in collection and sorting should be considerable. A study...... was undertaken to investigate the factors affecting quality in plastics recycling. The preliminary results showed factors primarily influencing quality of plastics recycling to be polymer cross contamination, presence of additives, non-polymer impurities, and polymer degradation. Deprivation of plastics quality......, with respect to recycling, has been shown to happen throughout the plastics value chain, but steps where improvements may happen have been preliminary identified. Example of Cr in plastic samples analysed showed potential spreading and accumulation of chemicals ending up in the waste plastics. In order...

  16. Glassy metallic plastics

    Institute of Scientific and Technical Information of China (English)

    2010-01-01

    This paper reports a class of bulk metallic glass including Ce-, LaCe-, CaLi-, Yb-, and Sr-based metallic glasses, which are regarded as glassy metallic plastics because they combine some unique properties of both plastics and metallic alloys. These glassy metallic plastics have very low glass transition temperature (Tg~25oC to 150oC) and low Young’s modulus (~20 GPa to 35 GPa). Similar to glassy plastics, these metallic plastics show excellent plastic-like deformability on macro-, micro- and even nano-scale in their supercooled liquid range and can be processed, such as elongated, compressed, bent, and imprinted at low temperatures, in hot water for instance. Under ambient conditions, they display such metallic properties as high thermal and electric conductivities and excellent mechanical properties and other unique properties. The metallic plastics have potential applications and are also a model system for studying issues in glass physics.

  17. Modelització i control d'una màquina termosolar Dish-Stirling

    OpenAIRE

    Nieto Estévez, Albert

    2014-01-01

    En aquest projecte es realitza una modelització dinàmica d’un sistema d’energia termosolar concentrada Dish-Stirling i es dissenyen els convertidors estàtics back-to-back per optimitzar la potència extreta. Es presenta un model tèrmic per al sistema de concentració de radiació solar, un model termodinàmic del motor Stirling, el model elèctric d’un generador d’imants permanents i de convertidors de la màquina i de la xarxa. Els models s’implementen en MATLAB Simulink® i s’estudia el comp...

  18. Optical characterization of nonimaging dish concentrator for the application of dense-array concentrator photovoltaic system.

    Science.gov (United States)

    Tan, Ming-Hui; Chong, Kok-Keong; Wong, Chee-Woon

    2014-01-20

    Optimization of the design of a nonimaging dish concentrator (NIDC) for a dense-array concentrator photovoltaic system is presented. A new algorithm has been developed to determine configuration of facet mirrors in a NIDC. Analytical formulas were derived to analyze the optical performance of a NIDC and then compared with a simulated result obtained from a numerical method. Comprehensive analysis of optical performance via analytical method has been carried out based on facet dimension and focal distance of the concentrator with a total reflective area of 120 m2. The result shows that a facet dimension of 49.8 cm, focal distance of 8 m, and solar concentration ratio of 411.8 suns is the most optimized design for the lowest cost-per-output power, which is US$1.93 per watt.

  19. Cardiomyopathy in a dish: using human inducible pluripotent stem cells to model inherited cardiomyopathies.

    Science.gov (United States)

    Kamdar, Forum; Klaassen Kamdar, Andre; Koyano-Nakagawa, Naoko; Garry, Mary G; Garry, Daniel J

    2015-09-01

    Inherited cardiomyopathies, including hypertrophic cardiomyopathy, dilated cardiomyopathies, arrythmogenic right ventricular cardiomyopathy, and other inherited forms of heart failure, represent a unique set of genetically defined cardiovascular disease processes. Unraveling the molecular mechanisms of these deadly forms of human heart disease has been challenging, but recent groundbreaking scientific advances in stem cell technology have allowed for the generation of patient-specific human inducible stem cell (hiPSC)-derived cardiomyocytes (CMs). hiPSC-derived CMs retain the genetic blueprint of the patient, they can be maintained in culture, and they recapitulate the phenotypic characteristics of the disease in vitro, thus serving as a disease in a dish. This review provides an overview of in vitro modeling of inherited cardiomyopathies with the use of patient-specific hiPSC-derived CMs. Copyright © 2015. Published by Elsevier Inc.

  20. Optical Design of a Solar Dish Concentrator Based on Triangular Membrane Facets

    Directory of Open Access Journals (Sweden)

    Hongcai Ma

    2012-01-01

    Full Text Available The design of a solar dish concentrator is proposed based on triangular membrane facets for space power applications. The facet concentrator approximates a parabolic surface supported by a deployable perimeter truss structure, which originates from a large aperture space antenna. For optimizing the number of facets rows and focal-diameter ratio of the concentrator, Monte Carlo ray-tracing method is utilized to determine optical performance of the concentrator, and the system root-mean-square (RMS deviation is considered in this design procedure. A 600-facet concentrator with focal-diameter ratio of 1.1 will achieve 83.63% of radiative collection efficiency over a 15 cm radius disk located in the focal plane, with a mean solar concentration ratio exceeding 300. The study in this paper is helpful for the development of the membrane facet concentrator.