Hybrid filter detection network model for secondary user transmission in cognitive radio networks

2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
D. Vijaya Saradhi ◽  
Swetha Katragadda ◽  
Hima Bindu Valiveti

PurposeA huge variety of devices accumulates as well distributes a large quantity of data either with the help of wired networks or wireless networks to implement a wide variety of application scenarios. The spectrum resources on the other hand become extremely unavailable with the development of communication devices and thereby making it difficult to transmit data on time.Design/methodology/approachThe spectrum resources on the other hand become extremely unavailable with the development of communication devices and thereby making it difficult to transmit data on time. Therefore, the technology of cognitive radio (CR) is considered as one of the efficient solutions for addressing the drawbacks of spectrum distribution whereas the secondary user (SU) performance is significantly influenced by the spatiotemporal instability of spectrum.FindingsAs a result, the technique of the hybrid filter detection network model (HFDNM) is suggested in this research work under various SU relationships in the networks of CR. Furthermore, a technique of hybrid filter detection was recommended in this work to enhance the performance of idle spectrum applications. When compared to other existing techniques, the suggested research work achieves enhanced efficiency with respect to both throughputs as well as delay.Originality/valueThe proposed HFDNM improved the transmission delay at 3 SUs with 0.004 s/message and 0.008 s/message when compared with existing NCNC and NNC methods in case of number of SUs and also improved 0.02 s/message and 0.08 s/message when compared with the existing methods of NCNC and NNC in case of channel loss probability at 0.3.

2019 ◽  
Vol 11 (3) ◽  
pp. 328-341
Author(s):  
Rifki Ismal ◽  
Nurul Izzati Septiana

Purpose The demand for Saudi Arabian real (SAR) is very high in the pilgrimage (hajj) season while the authority, unfortunately, does not hedge the hajj funds. As such, the hajj funds are potentially exposed to exchange rate risk, which can impact the value of hajj funds and generate extra cost to the pilgrims. The purpose of this paper is to conduct simulations of Islamic hedging for pilgrimage funds to: mitigate and minimize exchange rate risk, identify and recommend the ideal time, amount and tenors of Islamic hedging for hajj funds, estimate cost saving by pursuing Islamic hedging and propose technical and general recommendations for the authority. Design/methodology/approach Forward transaction mechanism is adopted to compute Islamic forward between SAR and Rupiah (Indonesian currency) or IDR. Findings – based on simulations, the paper finds that: the longer the Islamic hedging tenors, the better is the result of Islamic hedging, the decreasing of IDR/USD is the right time to hedge the hajj funds and, on the other hand, the IDR/SAR appreciation is not the right time to hedge the hajj funds. Findings Based on simulations, the paper finds that: the longer the Islamic hedging tenors, the better is the result of Islamic hedging, the decreasing of IDR/USD is the right time to hedge the hajj funds and, on the other hand, the IDR/SAR appreciation is not the right time to hedge the hajj funds. Research limitations/implications The research suggests the authority to (and not to) hedge the hajj fund, depending on economic conditions and market indicators. Even though the assessment is for the Indonesian case, other countries maintaining hajj funds might also learn from this paper. Originality/value To the best of author’s knowledge, this is the first paper in Indonesia that attempts to simulate the optimal hedging of hajj funds.


2016 ◽  
Vol 24 (2) ◽  
pp. 106-122 ◽  
Author(s):  
Jase R. Ramsey ◽  
Amine Abi Aad ◽  
Chuandi Jiang ◽  
Livia Barakat ◽  
Virginia Drummond

Purpose The purpose of this paper is to establish under which conditions researchers should use the constructs cultural intelligence (CQ) and global mindset (GM). The authors further seek to understand the process through which these constructs emerge to a higher level and link unit-level knowledge, skills and abilities (KSAs) capital to pertinent firm-level outcomes. Design/methodology/approach This paper is a conceptual study with a multilevel model. Findings This paper differentiates two similar lines of research occurring concordantly on the CQ and GM constructs. Next, the authors develop a multilevel model to better understand the process through which CQ and GM emerge at higher levels and their underlying mechanisms. Finally, this paper adds meaning to the firm-level KSAs by linking firm-level KSAs capital to pertinent firm-level outcomes. Research limitations/implications The conclusion implies that researchers should use CQ when the context is focused on interpersonal outcomes and GM when focused on strategic outcomes. The multilevel model is a useful tool for scholars to select which rubric to use in future studies that have international managers as the subjects. The authors argue that if the scholar is interested in an individual’s ability to craft policy and implement strategy, then GM may be more parsimonious than CQ. On the other hand, if the focus is on leadership, human resources or any other relationship dependent outcome, then CQ will provide a more robust measure. Practical implications For practitioners, this study provides a useful tool for managers to improve individual-level commitment by selecting and training individuals high in CQ. On the other hand, if the desired outcome is firm-level sales or performance, the focus should be on targeting individuals high in GM. Originality/value This is the first theoretical paper to examine how CQ and GM emerge to the firm level and describe when to use each measure.


1990 ◽  
Vol 19 (1) ◽  
pp. 41-41
Author(s):  
René Lemarchand

My apologies to Mr. Chrétien and to your readers for “developing some simplistic formulas on Burundi” in my quest for “media success.” No such simplistic formulas enter his criticism of my Congressional testimony. On the one hand, I am taken to task for not conceding that my interpretation of the Hutu-Tutsi conflict as a recent phenomenon is the product of Chrétien’s “patient research work” over the last quarter of a century; on the other hand, “some very similar analysis” had appeared in my “excellent work of 1970,” which came out long before Mr. Chrétien embarked on his patient research! Try to figure that one out if you can.


Lampas ◽  
2021 ◽  
Vol 54 (1) ◽  
pp. 119-136
Author(s):  
Robert Pitt

Abstract Most well-known inscriptions are monumental texts carved on stone. In this contribution, on the other hand, we focus on small, often informal texts scratched or stamped on rocks, metal surfaces and pottery. To this type of so-called ‘little epigraphy’ belong for instance graffiti, ostraca, weights and measures, curse tablets, etcetera. Although the texts themselves are usually very short, together they constitute a large corpus.


2021 ◽  
Author(s):  
Jaydip Sen ◽  
Sidra Mehtab ◽  
Gourab Nath

Prediction of future movement of stock prices has been a subject matter of many research work. On one hand, we have proponents of the Efficient Market Hypothesis who claim that stock prices cannot be predicted, on the other hand, there are propositions illustrating that, if appropriately modeled, stock prices can be predicted with a high level of accuracy. There is also a gamut of literature on technical analysis of stock prices where the objective is to identify patterns in stock price movements and profit from it. In this work, we propose a hybrid approach for stock price prediction using five deep learning-based regression models. We select the NIFTY 50 index values of the National Stock Exchange (NSE) of India, over a period of December 29, 2014 to July 31, 2020. Based on the NIFTY data during December 29, 2014 to December 28, 2018, we build two regression models using <i>convolutional neural networks</i> (CNNs), and three regression models using <i>long-and-short-term memory</i> (LSTM) networks for predicting the <i>open</i> values of the NIFTY 50 index records for the period December 31, 2018 to July 31, 2020. We adopted a multi-step prediction technique with <i>walk-forward validation</i>. The parameters of the five deep learning models are optimized using the grid-search technique so that the validation losses of the models stabilize with an increasing number of epochs in the model training, and the training and validation accuracies converge. Extensive results are presented on various metrics for all the proposed regression models. The results indicate that while both CNN and LSTM-based regression models are very accurate in forecasting the NIFTY 50 <i>open</i> values, the CNN model that previous one week’s data as the input is the fastest in its execution. On the other hand, the encoder-decoder convolutional LSTM model uses the previous two weeks’ data as the input is found to be the most accurate in its forecasting results.


2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Guilherme Magacho ◽  
Rafael Ribeiro ◽  
Igor Rocha

Purpose As economies with high economic complexity and productive capabilities may easily adapt their productive structure due to product differentiation and innovation, the central variable of competitiveness for these countries is the product quality, not price. On the other hand, the price can be an important determinant of less complex countries, and hence, real exchange rate (RER) misalignments may have long-term impacts. This paper aims to empirically assess variations in the magnitude of the impact in RER misalignments on output growth subject to countries’ economic complexity. Design/methodology/approach The estimation technique used is the generalized method of moments-System estimator as this method is robust to reverse causality. Heterogeneous regressions using interaction models are undertaken to analyze to what extend promoting economic complexity can reduce price competitiveness dependence and allow countries to grow faster without relying on cost competitiveness. Findings Estimates show that economic complexity (which measures technological and productive capabilities) determines cross-country differences regarding the effects of RER misalignments on countries’ long-term growth rates. The results suggest that exchange rate devaluations may not be effective for countries at the top end of the technological ladder while an overvalued RER may damage the long-term growth rate of countries with low levels of economic complexity. Originality/value This paper contributes to the literature by empirically investigating the impact of RER misalignments in countries with distinct technological and productive capabilities based on the recent developments of countries’ economic complexity analysis. It investigates whether more diversified and complex economies are less sensitive to RER misalignments as they can adapt their production, undertake other tasks, create new products and increase the quality of products they produce. Less complex economies, on the other hand, are less capable of innovating because it demands productive capabilities they do not have, and hence, they are more dependent on their current export basket.


2019 ◽  
Vol 24 (3) ◽  
pp. 230-238
Author(s):  
Luciana Pereira de Vasconcelos ◽  
Luiza de Oliveira Rodrigues ◽  
Moacyr Roberto Cuce Nobre

Purpose Good medical practice, evidence-based medicine (EBM) and clinical practice guidelines (CPG) have been recurring subjects in the scientific literature. EBM advocates argue that good medical practice should be guided by evidence-based CPG. On the other hand, critical authors of EBM methodology argue that various interests undermine the quality of evidence and reliability of CPG recommendations. The purpose of this paper is to evaluate patient related outcomes of CPG implementation, in light of EBM critics. Design/methodology/approach The authors opted for a rapid literature review. Findings There are few studies evaluating the effectiveness of CPG in patient-related outcomes. The systematic reviews found are not conclusive, although they suggest a positive impact of CPGs in relevant outcomes. Research limitations/implications This work was not a systematic review of literature, which is its main limitation. On the other hand, arguments from EBM and CPG critics were considered, and thus it can enlighten health institutions to recognize the caveats and to establish policies toward care improvement. Originality/value The paper is the first of its kind to discuss, based on the published literature, next steps toward better health practice, while acknowledging the caveats of this process.


2020 ◽  
Vol 132 (1) ◽  
pp. 121-126
Author(s):  
Raymond de Hoop

AbstractThe variant ויפחז in 4QSamb (4Q52) for MT ויקם in 1 Sam 20:34a is critically evaluated. It is suggested here that the reading of ויפחז in 4QSamb is due to metathesis of the consonants פ and ח, and that the original reading might have been ויחפז, »and he hurried away«. The suggested solution would fit the context very well and would also explain the apparent differences between 4QSamb, and on the other hand MT and LXX.


1977 ◽  
Vol 47 (6) ◽  
pp. 864-870 ◽  
Author(s):  
Gajanan V. Sherbet ◽  
M. S. Lakshmi ◽  
Salim K. Haddad

✓ Dexamethasone (104M) was shown to inhibit the growth of human gliomas in culture. This was indicated by the inhibition of incorporation of radioactively labeled thymidine into the deoxyribonucleic acid (DNA) of the cells, and by the increase in the generation time of cells exposed to the drug in vitro. On the other hand, tumors obtained from patients who had received dexamethasone before craniotomy grew considerably faster in vitro than tumors from patients who had not been given the drug before operation.


Significance The 50.2% of voters who rejected the agreement may prove sufficient to force the FARC back to war. Impacts The ceasefire may hold for some time, but disarmament is now extremely unlikely. Santos's popularity could fall further, and he may be forced to resign before his term ends. On the other hand, 'yes' voters may rally around him, boosting his approval ratings. Tourism and foreign investment are likely to suffer, with the prospect of any 'peace dividend' now remote.


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