373 research outputs found
Precious Metals-Exchange Rate Volatility Transmissions and Hedging Strategies
This study examines the conditional volatility and correlation dependency and interdependency for the four major precious metals (that is, gold, silver, platinum and palladium), while accounting for geopolitics within a multivariate system. The implications of the estimated results for portfolio designs and hedging strategies are also analyzed. The results for the four metals system show significant short-run and long-run dependencies and interdependencies to news and past volatility. These results have become more pervasive when the exchange rate and FFR are included. Monetary policy also has a differential impact on the precious metals and the exchange rate volatilities. Finally, the applications of the results show the optimal weights in a two-asset portfolio and the hedging ratios for long positions.
"Precious Metals-Exchange Rate Volatility Transmissions and Hedging Strategies"
This study examines the conditional volatility and correlation dependency and interdependency for the four major precious metals (that is, gold, silver, platinum and palladium), while accounting for geopolitics within a multivariate system. The implications of the estimated results for portfolio designs and hedging strategies are also analyzed. The results for the four metals system show significant short-run and long-run dependencies and interdependencies to news and past volatility. These results have become more pervasive when the exchange rate and FFR are included. Monetary policy also has a differential impact on the precious metals and the exchange rate volatilities. Finally, the applications of the results show the optimal weights in a two-asset portfolio and the hedging ratios for long positions.
Reliability and Safety Modeling of a Digital Feed Water Control System
Much digital instrumentation and control systems embedded in the critical
medical healthcare equipment aerospace devices and nuclear industry have
obvious consequence of different failure modes. These failures can affect the
behavior of the overall safety critical digital system and its ability to
deliver its dependability attributes if any defected area that could be a
hardware component or software code embedded inside the digital system is not
detected and repaired appropriately. The safety and reliability analysis of
safety critical systems can be accomplished with Markov modeling techniques
which could express the dynamic and regenerative behavior of the digital
control system. Certain states in the system represent system failure while
others represent fault free behavior or correct operation in the presence of
faults. This paper presents the development of a safety and reliability
modeling of a digital feedwater control system using Markov based chain models.
All the Markov states and the transitions between these states were assumed and
calculated from the control logic for the digital control system. Finally based
on the simulation results of modeling the digital feedwater control system the
system does meet its reliability requirement with the probability of being in
fully operational states is 0.99 over a 6 months time.Comment: 13 pages, 7 figures, conferenc
Reliability and Safety Modeling of a Digital Feed-Water Control System
إن الكثير من الأجهزة الرقمية وأنظمة التحكم المضمنة في معدات الرعاية الصحية الطبية الحيوية، وأجهزة الطيران، والصناعات النووية لها نتائج واضحة لأنماط الفشل المختلفة. يمكن أن تؤثر حالات الفشل هذه على سلوك النظام الرقمي الشامل للسلامة وقدرته على تقديم سمات الموثوقية الخاصة به إذا لم يتم الكشف عن أي منطقة معيبة يمكن أن تكون مكونًا من مكونات الأجهزة أو رمز البرنامج المضمّن داخل النظام الرقمي وإصلاحه بشكل مناسب. يمكن تحقيق تحليل السلامة والموثوقية للأنظمة الهامة للسلامة باستخدام تقنيات نمذجة ماركوف التي يمكن أن تعبر عن السلوك الديناميكي والتجديدي لنظام التحكم الرقمي. تمثل حالات معينة في النظام فشل النظام، بينما تمثل حالات أخرى سلوكًا خاليًا من الأخطاء أو عملية صحيحة في وجود أخطاء. تقدم هذه الورقة تطوير نمذجة السلامة والموثوقية لنظام التحكم الرقمي في مياه التغذية باستخدام نماذج السلسلة القائمة على ماركوف. تم افتراض جميع حالات ماركوف والتحولات بين هذه الحالات وحسابها من منطق التحكم لنظام التحكم الرقمي. أخيرًا ، استنادًا إلى نتائج المحاكاة لنمذجة نظام التحكم الرقمي في مياه التغذية ، فإن النظام يلبي متطلبات الموثوقية الخاصة به مع احتمال أن يكون في حالة التشغيل الكامل هو 0.99 على مدار 6 أشهر.Much digital instrumentation and control systems embedded in the critical medical healthcare equipment, aerospace devices, and nuclear industry have obvious consequence of different failure modes. These failures can affect the behavior of the overall safety-critical digital system and its ability to deliver its dependability attributes if any defected area that could be a hardware component or software code embedded inside the digital system is not detected and repaired appropriately. The safety and reliability analysis of safety-critical systems can be accomplished with Markov modeling techniques which could express the dynamic and regenerative behavior of the digital control system. Certain states in the system represent system failure, while others represent fault free behavior or correct operation in the presence of faults. This paper presents the development of a safety and reliability modeling of a digital feedwater control system using Markov-based chain models. All the Markov states and the transitions between these states were assumed and calculated from the control logic for the digital control system. Finally, based on the simulation results of modeling the digital feedwater control system, the system does meet its reliability requirement with the probability of being in fully operational states is 0.99 over a 6 months’ time.
 
Proposed system for data security in distributed computing in using triple data encryption standard and Rivest Shamir Adlemen
Cloud computing is considered a distributed computing paradigm in which resources are provided as services. In cloud computing, the applications do not run from a user’s personal computer but are run and stored on distributed servers on the Internet. The resources of the cloud infrastructures are shared on cloud computing on the Internet in the open environment. This increases the security problems in security such as data confidentiality, data integrity and data availability, so the solution of such problems are conducted by adopting data encryption is very important for securing users data. In this paper, a comparative study is done between the two security algorithms on a cloud platform called eyeOS. From the comparative study it was found that the Rivest Shamir Adlemen (3kRSA) algorithm outperforms that triple data encryption standard (3DES) algorithm with respect to the complexity, and output bytes. The main drawback of the 3kRSA algorithm is its computation time, while 3DES is faster than that 3kRSA. This is useful for storing large amounts of data used in the cloud computing, the key distribution and authentication of the asymmetric encryption, speed, data integrity and data confidentiality of the symmetric encryption are also important also it enables to execute required computations on this encrypted data.
SYNTHESIS, CHARACTERIZATION AND ANTIMICROBIAL ACTIVITY OF NOVEL PYRAZOLO[3,4-b]PYRIDINES AND THEIR SPIRO-HETEROCYCLIC DERIVATIVES
The present work describes the synthesis of a novel series of heterocyclic moieties derived from 5-acetylpyrazolo[3,4-b]pyridine (1). The formation of chalcones (2a-d) was utilized to synthesize pyrazoline, isoxazoline and pyrimidine derivatives (3-10). Thiosemicarbazone and semicarbazone (11, 17) were utilized to synthesize other new triazolethiones, thiadiazole and selenadiazole derivatives (11-19). Some new spiro derivatives (22-25) were synthesized by the reaction of chalcone (21) of 1 and isatine with hydrazines, hydroxyl amines and thiourea. Also, The reaction of 1 with cyanoacetyl hydrazine gave the hydrazide-hydrazone derivative 26, which was allowed to react with aromatic aldehydes and α-cyanocinnamonitrile to afford coumarine and substituted pyridine derivatives (28, 29). The structures of all the new compounds have been established on the basis of their analytical and spectral data. Twenty two of the synthesized compounds were also evaluated for their antibacterial and antifungal activity against various strains of bacteria and fungi and most are found to possess promising antimicrobial activity when compared with Chloramphenicol and Clotrimazol
Best S-box amongst differently sized S-boxes based on the avalanche effect in the advance encryption standard algorithm
Substitution boxes are essential nonlinear modules that are popular in block cipher algorithms. They also play a significant role in the security area because of their robustness to different linear cryptanalysis. Each element of the state in a S-box is nonlinearly replaced using a lookup table. This research presents the S-box, one of the fundamental parts of the advanced encryption standard (AES) algorithm. The S-box represents the confusion part in the AES. However, when information is shared between different devices in an authorized manner, the algorithm should be able to combine a sufficient number of confusion layers to guarantee the avalanche effect (AE). Subsequently, this research selects the best S-box by comparing different sizes (4×4, 8×8, and 16×16) and measuring them on the basis of the million-bit encryption. The AE is the main criterion used in choosing the best S-box. A robust and strong cryptography algorithm should be able to confirm the AEs. Results indicate that the 16×16 S-box with a 52% AE ratio is the superior S-bo
Integration of renewable energy resources into the distribution network : a review on required power quality
Power quality is the critical element of modern power system network where more and more distributed energy resources (DER) can be found. Distributed generation, generates electricity from many small DER particularly from renewable sources. Distributed generator (DG) within the network from renewable energy resources (RER) like solar and wind, bring significant challenges to maintain acceptable power quality (PQ) at the consumer end. This paper investigates PQ issues associated with RER. It reviews existing PQ standards for distribution network (DN) and also summarized the experiences of several Distributed Network Service Provider (DNSP) while integrating DGs into the grid. It was found that few PQ parameter ranges varies in different standards due to lack of harmonization and that may hinder to accept bulk renewable energy into the grid
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