1,721 research outputs found
Adelic Openness for Drinfeld Modules in Special Characteristic
For any Drinfeld module of special characteristic p0 over a finitely
generated field, we study the associated adelic Galois representation at all
places different from p0 and \infty, and determine the image of the geometric
Galois group up to commensurability
DeepPR: Progressive Recovery for Interdependent VNFs with Deep Reinforcement Learning
The increasing reliance upon cloud services entails more flexible networks
that are realized by virtualized network equipment and functions. When such
advanced network systems face a massive failure by natural disasters or
attacks, the recovery of the entire system may be conducted in a progressive
way due to limited repair resources. The prioritization of network equipment in
the recovery phase influences the interim computation and communication
capability of systems, since the systems are operated under partial
functionality. Hence, finding the best recovery order is a critical problem,
which is further complicated by virtualization due to dependency among network
nodes and layers. This paper deals with a progressive recovery problem under
limited resources in networks with VNFs, where some dependent network layers
exist. We prove the NP-hardness of the progressive recovery problem and
approach the optimum solution by introducing DeepPR, a progressive recovery
technique based on Deep Reinforcement Learning (Deep RL). Our simulation
results indicate that DeepPR can achieve the near-optimal solutions in certain
networks and is more robust to adversarial failures, compared to a baseline
heuristic algorithm.Comment: Technical Report, 12 page
Silica veins in gaj-lazine locality (Central Serbia) as gemstone
Gemstone occurrence Gaj-Lazine is located in central Serbia, 3.5 km SE of Stragari. Prevailinggemstone type is opaque chalcedony–jasper and colourless chalcedony. Subordinate crystalline quartz and carbonateminerals are also present. They all appear as single veins and, more often, intricate stockworks, filling up fractures inserpentinite of the Vardar zone ophiolitic sequence. Genetic processes of this occurrence are connected to the Neogenecalc-alkaline magmatic activity of the Vardar zone and hydrothermal activity triggered by it. Economic significanceof this gemstone deposit is high for jasper and minor for other present gemstone types, due to their minor occurrences
Assessing insect-based products as feed ingredients for aquaculture
Research has been actively looking for alternative feed ingredients to reduce the reliance of the aquafeed industry on marine ingredients, namely fish meal (FM) and fish oil (FO). In this context, insects, in particular housefly (Musca domestica) and black soldier fly (BSF, Hermetia illucens) larvae, have been identified as promising candidates. Although a global insect farming industry is emerging, it is for now constrained by regulatory and technical bottlenecks that raise the question ‘where and how insect-based products could be integrated into aquaculture’. The literature indicated a high interspecies variability of the results when replacing FM with insect meals in fish diets and previous work failed to consider the existing challenges related to the insect production to demonstrate commercial relevance and applicability. In this thesis, maggot meals (MM) and frass (insect digestate) were assessed as strategic feed ingredients for two commercially important farmed species: Atlantic salmon, (Salmo salar) and Nile tilapia (Oreochromis niloticus), in their relevant contexts. Case studies showed that both housefly and BSF MM are high quality feed ingredients and suitable alternative to FM. Specifically, dietary inclusions of up to 200 g/kg of crude or defatted housefly larvae meal did not compromised the feed digestibility and utilisation and the growth performance and body composition of salmon parr (freshwater stage), compared to a FM-based control diet. Hormone (17α-methyltestosterone) treated diets containing between 250 and 1000 g/kg BSF or housefly meal were found as effective as a commonly used pure hormone-treated FM in sex-reversal process leading to 99.8 to 100% males, high survival and evenness of the fish produced. In a commercial diet for advanced nursing of Nile tilapia fingerlings, up to 80 g/kg BSF meal was included without impairing the fish performance and body composition; dietary inclusion was limited by the lipid content of the crude MM. Finally, BSF frass derived from brewery spent grains or processed food wastes were found more effective when used as soil bio-fertilisers with minimum application rate of 10.0 tonnes/ha or 5.0 tonnes/ha, respectively (for a spring onion culture), rather than supplemental feeds for tilapia farmed in semi-intensive conditions (fertilised pond). The study also indicated that site-specific conditions should be accounted to support appropriate and sustainable use of insect-based products but in any case, juvenile fish should be strategically targeted given their requirements. It is expected that this approach, could support the sustainable intensification of aquaculture and contribute more broadly to food security whilst contributing to the development of a circular economy
Evaluation of the uncertainty in an EBT3 film dosimetry system utilizing net optical density
Radiochromic film has become an important tool to verify dose distributions for intensity-modulated radiotherapy (IMRT) and quality assurance (QA) procedures. A new radiochromic film model, EBT3, has recently become available, whose composition and thickness of the sensitive layer are the same as those of previous EBT2 films. However, a matte polyester layer was added to EBT3 to prevent the formation of Newton’s rings. Furthermore, the symmetrical design of EBT3 allows the user to eliminate side-orientation dependence. This film and the flatbed scanner, Epson Perfection V750, form a dosimetry system whose intrinsic characteristics were studied in this work. In addition, uncertainties associated with these intrinsic characteristics and the total uncertainty of the dosimetry system were determined. The analysis of the response of the radiochromic film (net optical density) and the fitting of the experimental data to a potential function yielded an uncertainty of 2.6%, 4.3%, and 4.1% for the red, green, and blue channels, respectively. In this work, the dosimetry system presents an uncertainty in resolving the dose of 1.8% for doses greater than 0.8 Gy and less than 6 Gy for red channel. The films irradiated between 0 and 120 Gy show differences in the response when scanned in portrait or landscape mode; less uncertainty was found when using the portrait mode. The response of the film depended on the position on the bed of the scanner, contributing an uncertainty of 2% for the red, 3% for the green, and 4.5% for the blue when placing the film around the center of the bed of scanner. Furthermore, the uniformity and reproducibility radiochromic film and reproducibility of the response of the scanner contribute less than 1% to the overall uncertainty in dose. Finally, the total dose uncertainty was 3.2%, 4.9%, and 5.2% for red, green, and blue channels, respectively. The above uncertainty values were obtained by minimizing the contribution to the total dose uncertainty of the film orientation and film homogeneity
Wireless networks in industrial environments: state of the art and issues
Wireless is everywhere nowadays and WLAN (i.e. 802.11 standard family) has became used by almost any communications devices in the mass market.
The recent achievements in the fields of modulation techniques, such as Spread Spectrum, coding methods, such as Turbocodes, CDMA2000, and frequencies allocation methods, such as OFDM and Frequency Hopping, has pushed the growing uses of reliable and low-cost wireless technologies. Among them the last standards are: IEEE 802.11 family (i.e. WiFi), HyperLAN and HyperLAN2, IEEE 802.15 (i.e. WPAN), IEEE 802.16 (i.e. WiMAX)… However, the industrial environments are not taken into consideration in the design of those standards, because its harsh constraints has specific characteristics (reliability, interferences with existing equipments, multi-path propagation, low-power consumption, real-time reconfiguration, security…) that need specific requirements and eventually standards.
This paper will intent to give an overview of the wireless technologies and discusses the current and future possible technologies for the uses in the industrial environments (power plants and stations, factories, industrial buildings, automotive…).
Our current works showed us that there is no perfect technology by it-self but the best trade-off solution is a hybrid architecture combining the right wired and wireless technologies.1st IFIP International Conference on Ad-Hoc NetWorkingRed de Universidades con Carreras en Informática (RedUNCI
Implementasi Metode Hazop Dalam Proses Identifikasi Bahaya Dan Analisis Risiko Pada High Pressure Heater (HPH) Di PT. PJB Unit Pembangkit 4 Gresik
Di PT. PJB UP Gresik terdapat high pressure heater (HPH)
sebagai pemanas awal dengan tekanan tinggi yang mendapatkan
feedwater dari boiler feed pump (BFP).Bahaya timbul baik
berasal dari komponen-komponennya sendiri, mapun yang
berasal dari luar. Dengan pemanasan awal pada air umpan, maka
efisiensi di sebuah PLTU dapat ditingkatan dengan alasan bahwa
setelah air umpan yang dipanaskan awal akan memerlukan panas
yang lebih sedikit pada proses pemanasan di boiler dibandingkan
tanpa unit heater.[2]Pada tahun 2008 dan 2014 terdapat
kegagalan pada system HPH yang mengakibatkan terjadinya
bypass. Berdasarkan alasan tersebut, perlu dilakukan identifikasi
bahaya dan analisis resiko dengan metode HAZOP. Tingkat risiko
bahaya didapatkan dari perkalian likelihood dan consequence
berdasarkan standar PT. PJB UP Gresik. Dari hasil analisis
terdapat dua bahaya, yaitu pecahnya tube sehingga menaikkan
level dan tekanan drum serta hilangnya feedwater pada HPH serta
kegagalan system minimal flow yang dapat mengakibatkan
kavitasi sehingga merusak BFP. Dari HAZOP
worksheet,diperoleh instrumen yang memiliki risiko rendah
berjumlah 3. Dan instrumen dengan tingkat risiko menengah
sebanyak 15. Selain itu terdapat pula instrumen dengan risiko
tinggi dengan jumlah 14.
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In PT. PJB UP Gresik use high pressure heater (HPH) as a
preheater with boiler feed pump(BFP) as suplier of feed water.By
preheating the feed water, we can increase efficiency of power
plant the reason is after the initial heated feed water will require
less heat in the heating process in the boiler compared without
preheater unit.[2] Hazard arise either from the components
themselves, or coming from outside. Based on these reasons, it is
necessary to identify the hazard and risk analysis with HAZOP
method.Hazard risk level is obtained by multiplying the likelihood
and consequence based on the standard PT. PJB UP Gresik.From
the analysis there are two dangers, namely the outbreak of the
tube so as to raise the level and pressure drums as well as the
loss of feedwater on HPH and minimal flow system failures that
can result in cavitation thus damaging the BFP. From HAZOP
worksheet, obtained 3 instrument with low risk . And instrumen
with moderate-risk as much as 15. In addition there is also
14instrument with high risk
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