689 research outputs found
A performance comparison of LTE downlink scheduling algorithms in time and frequency domains
No full textA number of scheduling algorithms for LTE downlink have been proposed and evaluated leveraging the flexibility of the resource allocation in both the time and the frequency domain. However, the existing literature falls short when it comes to schedulers that provide throughput guarantees. In this paper, we contribute to fill this gap by implementing a scheduling algorithm that provides long-term throughput guarantees to the different users, while opportunistically exploiting the instantaneous channel fluctuations to increase the cell capacity. We perform a thorough performance analysis comparing this algorithm with the other well known algorithms by means of extensive ns-3 simulations, both for saturated UDP and TCP traffic sources. The analysis makes it possible to appreciate the difference among the scheduling algorithms, and to assess the performance gain, both in terms of cell capacity and packet service time, obtained by allowing the schedulers to work in the frequency domain
Service differentiation for improved cell capacity in LTE networks
No full textThe wide flexibility of LTE resource allocation scheme has led to the definition of various schedulers that attempt to maximize the quality of the service offered to the different users, depending on their channel conditions. Unfortunately, providing service guarantees in dynamic channel conditions typically requires a cost in terms of spectral efficiency of the transmission resource allocation. In this work, we investigate this tradeoff and propose a resource allocation scheme that adapts the service level guarantees to the average channel conditions of the users, in order to provide fair resource allocation among users with homogeneous channel conditions, while improving the cell spectral efficiency. A performance analysis is carried out by comparing the proposed scheduler with other well known schedulers. Results show that the proposed method can improve the cell capacity, while guaranteeing long-term throughput fairness among users of the same class. In addition, we analyze the short-term throughput provided by the proposed scheduler and provide a semi-analytical model to assess the gap with respect to the long-term performance
Scheduling Policies in Time and Frequency Domains for LTE Downlink Channel: A Performance Comparison
No full textA key feature of the Long-Term Evolution (LTE) system is that the packet scheduler can make use of the channel quality information (CQI), which is periodically reported by user equipment either in an aggregate form for the whole downlink channel or distinguished for each available subchannel. This mechanism allows for wide discretion in resource allocation, thus promoting the flourishing of several scheduling algorithms, with different purposes. It is therefore of great interest to compare the performance of such algorithms under different scenarios. Here, we carry out a thorough performance analysis of different scheduling algorithms for saturated User Datagram Protocol (UDP) and Transmission Control Protocol (TCP) traffic sources, as well as consider both the time- and frequency-domain versions of the schedulers and for both flat and frequency-selective channels. The analysis makes it possible to appreciate the difference among the scheduling algorithms and to assess the performance gain, in terms of cell capacity, users' fairness, and packet service time, obtained by exploiting the richer, but heavier, information carried by subchannel CQI. An important part of this analysis is a throughput guarantee scheduler, which we propose in this paper. The analysis reveals that the proposed scheduler provides a good tradeoff between cell capacity and fairness both for TCP and UDP traffic sources
Perceptions and Preferences of Senior High School Students About Written Corrective Feedback in Pakistan
No full textMahmood, Rabia/0000-0001-7163-0577; Aslam, Muhammad Zammad/0000-0002-1475-5741; Barzani, Sami/0000-0003-3333-064X; Rasool, Ushba/0000-0002-0940-0241Written corrective feedback (WCF) in enhancing writing proficiency has been the subject of numerous studies, but few studies have examined students' perceptions about the value of feedback on their written errors. Language teachers use global tools and techniques to give students feedback on their written work. How feedback is delivered and received by students is valued differently. The current study concentrated on how students interpret written corrective feedback and which WCF tactics they favor in writing classrooms. To examine these objectives empirically, the researchers employed a self-administered questionnaire to collect data from 180 participants from a high secondary school in Multan, Pakistan. At the same time, 40 participants were interviewed for their opinions about written corrective feedback (WCF). Some participants expressed concerns about ambiguous feedback that confuses them about their errors, whereas most participants favored the feedback process as beneficial. The most preferred strategies were meta-linguistic explanation and direct written corrective feedback that facilitated writing proficiency and language knowledge. Overall, WCF guides errors to avoid and how to adapt their writing style for composing compelling manuscripts
A Comparative Perspective on Legal Register in Pakistani English
No full textThe present study investigates linguistic variation of legal register in relation to other special and non-special registers in Pakistani English by applying multidimensional analysis approach introduced by Biber (1988) in his work “Variation across Speech and Writing”. In order to describe a register, a comparative register perspective yields baseline data to comprehend the linguistic properties of an individual register. Comparative studies show that there are significant linguistic differences among registers, known as the patterns of register variation. Thus the current study aims to reveal differences and similarities among legal register and other registers in Pakistani context. The corpus of the study includes legal register with eight legal genres and about two million words whereas mean dimension scores of other registers have been taken from Ahmad and Mahmood, 2015; Hussain, Mahmood and Azher, 2016; Alvi, Mehmood and Rasool, 2016. The results show that legal register and editorials are significantly different from each other along dimension 1,3,4,5 whereas legal register and press reportage are found statistically significantly different along all five dimensions. As regards comparison of legal register and non-special registers, the results reveal highly significant difference between them. It indicates that legal register has specific lexico-grammatical features which distinguish it from other registers. Difference among registers might be due to their different goals, norms and audience. It reveals that functional interpretations on the basis of texts regardless of register variation are inadequate
Synthesis, Density functional theory (DFT), Urease inhibition and antimicrobial activities of 5-aryl thiophenes bearing sulphonylacetamide moieties
No full textA variety of novel 5-aryl thiophenes 4a-g containing sulphonylacetamide (sulfacetamide) groups were synthesized in appreciable yields via Pd[0] Suzuki cross coupling reactions. The structures of these newly synthesized compounds were determined using spectral data and elemental analysis. Density functional theory (DFT) studies were performed using the B3LYP/6-31G (d, p) basis set to gain insight into their structural properties. Frontier molecular orbital (FMOs) analysis of all compounds 4a-g was computed at the same level of theory to get an idea about their kinetic stability. The molecular electrostatic potential (MEP) mapping over the entire stabilized geometries of the molecules indicated the reactive sites. First hyperpolarizability analysis (nonlinear optical response) were simulated at the B3LYP/6-31G (d, p) level of theory as well. The compounds were further evaluated for their promising antibacterial and anti-urease activities. In this case, the antibacterial activities were estimated by the agar well diffusion method, whereas the anti-urease activities of these compounds were determined using the indophenol method by quantifying the evolved ammonia produced. The results revealed that all the sulfacetamide derivatives displayed antibacterial activity against Bacillus subtiles, Escherichia coli, Staphylococcus aureus, Shigella dysenteriae, Salmonella typhae, Pseudomonas aeruginosa at various concentrations. Furthermore, the compound 4gN-((5-(4-chlorophenyl)thiophen-2-yl)sulfonyl) acetamide showed excellent urease inhibition with percentage inhibition activity similar to 46.23 +/- 0.11 at 15 mu g/mL with IC50 17.1 mu g/mL. Moreover, some other compounds 4a-f also exhibited very good inhibition against urease enzyme
Sensitive detection of pre-existing BCR-ABL kinase domain mutations in CD34+ cells of newly diagnosed chronic-phase chronic myeloid leukemia patients is associated with imatinib resistance: implications in the post-imatinib era
No full textBACKGROUND BCR-ABL kinase domain mutations are infrequently detected in newly diagnosed chronic-phase chronic myeloid leukemia (CML) patients. Recent studies indicate the presence of pre-existing BCR-ABL mutations in a higher percentage of CML patients when CD34+ stem/progenitor cells are investigated using sensitive techniques, and these mutations are associated with imatinib resistance and disease progression. However, such studies were limited to smaller number of patients. METHODS We investigated BCR-ABL kinase domain mutations in CD34+ cells from 100 chronic-phase CML patients by multiplex allele-specific PCR and sequencing at diagnosis. Mutations were re-investigated upon manifestation of imatinib resistance using allele-specific PCR and direct sequencing of BCR-ABL kinase domain. RESULTS Pre-existing BCR-ABL mutations were detected in 32/100 patients and included F311L, M351T, and T315I. After a median follow-up of 30 months (range 8–48), all patients with pre-existing BCR-ABL mutations exhibited imatinib resistance. Of the 68 patients without pre-existing BCR-ABL mutations, 24 developed imatinib resistance; allele-specific PCR and BCR-ABL kinase domain sequencing detected mutations in 22 of these patients. All 32 patients with pre-existing BCR-ABL mutations had the same mutations after manifestation of imatinib-resistance. In imatinib-resistant patients without pre-existing BCR-ABL mutations, we detected F311L, M351T, Y253F, and T315I mutations. All imatinib-resistant patients except T315I and Y253F mutations responded to imatinib dose escalation. CONCLUSION Pre-existing BCR-ABL mutations can be detected in a substantial number of chronic-phase CML patients by sensitive allele-specific PCR technique using CD34+ cells. These mutations are associated with imatinib resistance if affecting drug binding directly or indirectly. After the recent approval of nilotinib, dasatinib, bosutinib and ponatinib for treatment of chronic myeloid leukemia along with imatinib, all of which vary in their effectiveness against mutated BCR-ABL forms, detection of pre-existing BCR-ABL mutations can help in selection of appropriate first-line drug therapy. Thus, mutation testing using CD34+ cells may facilitate improved, patient-tailored treatment.Zafar Iqbal, Aamer Aleem, Mudassar Iqbal, Mubashar Iqbal Naqvi, Ammara Gill, Abid Sohail Taj, Abdul Qayyum, Najeeb ur-Rehman, Ahmad Mukhtar Khalid, Ijaz Hussain Shah, Muhammad Khalid, Riazul Haq, Mahwish Khan, Shahid Mahmood Baig, Abid Jamil, Muhammad Naeem Abbas, Muhammad Absar, Amer Mahmood, Mahmood Rasool, Tanveer Akhta
Lack of Method, Physicalism Approach and Lack of Phenomenological Perspective in Philosophy of Superstitions
No full text“Philosophy of Superstitions” has been authored as a work of second-order knowledge and philosophical perspective concerning the conceptual explanation and identification of different types of superstition, causes of human tendency towards superstitions and the method of battle with this problem. The mode of discussion of Professor Yasrebi of this issue bespeaks of his deep concerns of superstition particularly in its social aspect, but the author in the chapters of this work, instead of strengthening the philosophical perspective of the outlines of this problem, after a short review of the basic notions, turns to the extensions. Meanwhile, the most important problem is concerned with the “definition of superstition”. The distinguishing feature of the superstition as compared to other beliefs, its failure of consistency with rational foundations and drawn logical rules. Without paying attention to different applications of “reas” and requirements of thinking, Yasrebi considers rationality to have a unique condition in all times and spaces. Thus, he does not tolerate the relativity of the extensions of superstition in different societies and ages. Unfortunately, side effects of this great mistake can be seen in his explanation of the causes of the tendency towards superstition and its cure
مقالاتِ شیرانی کی روشنی میں تاریخِ مصوری
No full textThe essay "Muqalate sherani main masaweri kay dabistano ka taazqara" is on the life and workof hafiz mahmood sherani is well managed, graceful, readable and stimulating. The style is lucid, forcefuland eloquent his effort to picturize the creative work is matchless. Hafiz sherani proved his welldeveloped interests in sociology, religion, literature, painting architecture and sculpture. He showedcomplete confidence and competence on all these subjects. Further he was distinguished because of hisintense concern with the pligh of mankind and intense desire of reformation
اجتہاد الرسول ﷺ از نادیہ شریف العمری کا تعارفی مطالعہ: An Introductory Study of Ijtihad Al-Rasool ﷺ by Nadia Sharif Al-Omari
No full textThe biography of the Prophet ﷺ is a subject that has been extensively written about since the first century of Hijra, continues to be written about today, and will undoubtedly remain a topic of scholarly and devotional interest in the future. This subject holds religious, academic, historical, and contemporary significance, prompting Muslim scholars of every era to contribute to its exploration. Alongside men, women have also engaged in writing on this subject to express their devotion and love for the Prophet ﷺ. From ancient to modern times, women have played their part in this field, and while their contributions are fewer in comparison to men, their numbers are steadily increasing in modern times. Women have also explored various aspects of the Prophet's ﷺ biography in the Arabic language. One notable work in this context is "Ijtihad Al-Rasool" authored by Nadia Sharif Al-Omari. This book uniquely combines the principles of Islamic jurisprudence (Usul al-Fiqh) with the life of the Prophet ﷺ, analyzing whether the Prophet ﷺ engaged in ijtihad (independent reasoning). The author meticulously presents evidence supporting her conclusion that the Prophet ﷺ did indeed engage in ijtihad. This article provides a research-based and analytical study of her book. It begins by discussing the biographical details of the author, followed by an introduction to the book. Subsequently, the writing style of the author and the nuanced insights within her work are critically examined. Finally, the findings and recommendations of the study are presented.
- …
