5,492 research outputs found
Kaveh Akbar, 41st Annual ODU Literary Festival
No full textKaveh Akbar\u27s poems appear recently in The New Yorker, Poetry, The New York Times, The Nation, and elsewhere. His first book, Calling a Wolf a Wolf, is just out with Alice James in the US and Penguin in the UK. He is also the author of the chapbook Portrait of the Alcoholic. The recipient of a Pushcart Prize, a Ruth Lilly and Dorothy Sargent Fellowship from the Poetry Foundation, and the Lucille Medwick Memorial Award from the Poetry Society of America, Akbar was born in Tehran, Iran, and teaches in the MFA program at Purdue University and in the low-residency MFA programs at Randolph College
Akbar II as Pretender: A Study in Anarchy
No full textAkbar Shāh, son of the Mughal emperor Shāh 'Ālam II, was elevated to the throne of Delhi as pretender eighteen years previous to his accession as Akbar II, and money was struck in his name. The addition of another claimant to the dynastic list was communicated in a joint paper by Mr. S. H. Hodivala and myself, which appeared in the Journal of the Asiatic Society of Bengal for the year 1922, and to which I invite reference. I had found a copper coin of Aḥmadābād mint bearing the name of Akbar Shāh and date A.H. 1203, which made me conjecture whether Ghulām Qādir Khān, the “unspeakable Rohilla”, raised another prince to the Mughal throne after the puppet Bedār Bakht (A.H. 1202–3), who might or might not be identical with the Akbar Shāh, eldest surviving son of Shāh 'Ālam II, who succeeded his father in the regular way as Akbar II in the year A.H.. 1221 (A.D. 1806). I put the matter to Mr. Hodivala, a leading authority on Mughal history, and his reply was that “it has not yet been possible to find an absolutely complete and satisfactory solution of the problem connected with the Akbar Shāh coins of A.H. 1203, but there would seem to be fairly good grounds for answering the question in the affirmative”. The fullest account of the transactions which led to the deposition and blinding of Shāh 'Ālam II is in the 'Ibratnāmah (Book of Warning) of Faqīr Khairu-d-dīn Muḥammad, but this work closes soon after recounting the terrible cruelties practised on the Emperor Shāh 'Ālam and his family by the infamous Ghulām Qādir, whose atrocities the author describes at length.</jats:p
Synthesis, characterization and physical properties of ternary intermetallic compounds in the R-T-X systems (R = Yb, Eu; T = Cu, Pd; X = Zn, In, Sn, Bi)
No full textThe research work is focused primarily on the study of phase equilibria and discovery of new ternary compounds in R–T–X systems (where R = Yb, Eu; T = Cu, Pd; X = Zn, Sn, In, Bi); and the study of their physical properties.
These studies are driven by the interesting physical properties stated in the literature for ternary compounds in these systems. The detailed study of ternary phase diagrams is a powerful means to establish phase equilibria and to discover new ternary compounds. It also offers the possibility to successfully synthesize single phase materials surrounding the region of these ternary compounds from the comprehensive knowledge of phase equilibria.
The thesis is divided into six chapters with the first part explaining the experimental methods and characterization techniques employed to synthesize and analyze intermetallic compounds. It also explains the methods for measurement of physical properties for selective compositions in the ternary systems explained in the later four chapters. The remaining four chapters illustrate the main part of research work done during the course of PhD. Of these, the first two chapters describe the investigation of phase equilibria at 600 oC and compound formation in the Yb-based ternary systems i.e., (1) Yb–Pd–In and Yb-Pd-Bi (2) Yb–Cu–Zn systems. The third and fourth chapters describe the field of existence in the YbCu5-xZnx and YbCu5-xSnx solid solutions and the comparison of their physical properties with YbCu5-xAux and YbCu5-xInx systems respectively. The last chapter describes the crystal chemistry and physical properties of Eu2Pd3Sn compound. Finally, the whole thesis is concluded in the form of
brief summary
Dilasia indica Ballal & Akbar & Yamada & Wachkoo & Varshney 2018, comb. nov.
No full textDilasia indica (Muraleedharan, 1978) comb. nov. Lasiochilus indica Muraleedharan, 1978: 267. HOLOTYPE:, India: Tamil Nadu, Madras [= Chennai] (ZSI). Distribution in India. Tamil Nadu: Chennai (MURALEEDHARAN 1978). General distribution. Endemic. Taxonomy. MURALEEDHARAN (1978) originally described this species in the genus Lasiochilus Reuter, 1871. Judging from his description, the lack of punctures on hemelytra, strong spines on tibiae, and the shape of paramere are more conducive to its placement in Dilasia.Published as part of Ballal, Chandish R., Akbar, Shahid Ali, Yamada, Kazutaka, Wachkoo, Aijaz Ahmad & Varshney, Richa, 2018, Annotated catalogue of the flower bugs from India (Heteroptera: Anthocoridae, Lasiochilidae), pp. 207-226 in Acta Entomologica Musei Nationalis Pragae 58 (1) on page 221, DOI: 10.2478/aemnp-2018-0018, http://zenodo.org/record/369921
On the group of homeomorphisms on R: A revisit
No full text[EN] In this article, we prove that the group of all increasing homeomorphisms on R has exactly five normal subgroups, and the group of all homeomorphisms on R has exactly four normal subgroups. There are several results known about the group of homeomorphisms on R and about the group of increasing homeomorphisms on R ([2], [6], [7] and [8]), but beyond this there is virtually nothing in the literature concerning the topological structure in the aspects of topological dynamics. In this paper, we analyze this structure in some detail.The first author acknowledges SERB-MATRICS Grant No. MTR/2018/000256 for financial support. The second author acknowledges University of Calicut, Seed Money (U.O. No. 11733/2021/Admn; Dated: 11.10.2021), INDIA for financial support.Ali Akbar, K.; Mubeena, T. (2022). On the group of homeomorphisms on R: A revisit. Applied General Topology. 23(2):269-280. https://doi.org/10.4995/agt.2022.16143OJS269280232R. Arens, Topologies for Homeomorphism Groups, American Journal of Mathematics 68 (1946), 593-610. https://doi.org/10.2307/2371787N. J. Fine and G. E. Schweigert, On the group of homeomorphisms of an arc, Annals of Mathematics 62 (1955), 237-253. https://doi.org/10.2307/1969678M. Brin and G. Stuck, Introduction to Dynamical Systems, Cambridge University Press, 2002. https://doi.org/10.1017/CBO9780511755316R. L. Devaney, An Introduction to Chaotic Dynamical Systems, Addison-Wesley Publishing Company Advanced Book Program, Redwood City, CA, second edition, 1989.I. N. Herstein, Topics in Algebra, John Wiley and Sons, 2nd Revised edition, 1975.A. G. O'Farrell, Conjugacy, involutions, and reversibility for real homeomorphisms, Irish Math. Soc. Bulletin 54 (2004), 41-52. https://doi.org/10.33232/BIMS.0054.41.52S. Ulam and J. von Neumann, On the group of homeomorphisms of the surface of the sphere, (abstract), Bull. Amer. Math. Soc. 53 (1947), 506.J. V. Whittaker, Normal subgroups of some homeomorphism groups, Pacific J. Math. 10, no. 4 (1960), 1469-1478. https://doi.org/10.2140/pjm.1960.10.146
Review of Ali-Akbar Dehkhoda, Charand-o Parand (2019)
No full textReview of Ali-Akbar Dehkhoda, Charand-o Parand. Revolutionary Satire from Iran, 1907–1909, Translated by Janet Afary and John R. Perry, in Iranian Studie
CMOS integrated wideband, flexible and scalable beamforming architecture
No full textAbstract
This thesis presents the concepts and implementation of subarrays that offer flexible, scalable, and reconfigurable solutions for building large-scale arrays. Large-scale multi-beam phased array systems often experience inter-beam interference caused by independent subarrays. This interference must be cancelled either in analog and/or digital domains. Implementing interference rejection in the analog domain can relax the ADC dynamic range and reduce the number of required ADC bits. However, in broadband systems like 5G, rejecting interference over a wide bandwidth is challenging due to radio channel properties and receiver chain non-idealities. This work introduces a wideband architecture for mmWave to cover multiple frequency bands for future communication scenarios. The receiver architecture involves a two-stage beamforming approach for the multi-beam system. In the first stage, the subarray mmWave front-end covers the 5G NR bands (25–62 GHz) and improves the SNR by combining signals from antenna elements, providing spatial filtering. In the second stage, the system aims to implement a flexible inter-beam interference cancellation (IBIC) or combining signals from independent subarrays by utilizing an IF receiver (IF-RX) chip. The IF-RX chip offers interference rejection or a wideband signal combining between the subarrays. The interference rejection performance was measured over-the-air (OTA) using 5G NR signals. The results showed a rejection of 34–37 dB for 50–100 MHz signals while meeting the EVM requirements of the 5G NR standards with good margins. Finally, the interference rejections over a 4 x 100 MHz carrier-aggregated 5G NR waveform was demonstrated.
This work also proposes building large-scale phased array panels using grid-based PCB routing using chip-to-chip (C2C) interfaces. The implemented subarray RFIC features four 27 GHz C2C interfaces, two 9 GHz C2C interfaces, and a complex BB with > 400 MHz single-sided bandwidth. C2C interfaces use a frequency conversion module for signal combining/distribution. The subarray RFIC's module enables different modes of operation through an IF routing matrix, providing high reconfigurability. The frequency conversion can support horizontal and vertical combinations of signals in a large-scale panel. It can be used for IBIC in the BB domain, demonstrating the practical applications of the proposed system design. Original papers Akbar, R., Klumperink, E. A. M., Tervo, N., Javed, M. Y., Stadius, K., Rahkonen, T., & Pärssinen, A. (2019). A wideband IF receiver module for flexibly scalable mmWave beamforming combining and interference cancellation. ESSCIRC 2019 - IEEE 45th European Solid State Circuits Conference (ESSCIRC), 213–216. https://doi.org/10.1109/ESSCIRC.2019.8902869 https://doi.org/10.1109/ESSCIRC.2019.8902869 Self-archived version Akbar, R., Shaheen, R. A., Rahkonen, T., Tze, C., Stadius, K., & Pärssinen, A. (2021). A 38.5-to-60.5 GHz LNA with wideband combiner supporting cartesian beamforming architecture. ESSCIRC 2021 - IEEE 47th European Solid State Circuits Conference (ESSCIRC), 199–202. https://doi.org/10.1109/ESSCIRC53450.2021.9567865 https://doi.org/10.1109/ESSCIRC53450.2021.9567865 Self-archived version Akbar, R., Klumperink, E. A. M., Tervo, N., Stadius, K., Rahkonen, T., & Pärssinen, A. (2023). A wideband IF receiver chip for flexibly scalable mmWave subarray combining and interference rejection. IEEE Transactions on Microwave Theory and Techniques, 71(12), 5482–5497. https://doi.org/10.1109/TMTT.2023.3279919 https://doi.org/10.1109/TMTT.2023.3279919 Self-archived version Sethi, A., Akbar, R., Hietanen, M., Aikio, J. P., Kursu, O., Jokinen, M., Leinonen, M. E., Rahkonen, T., & Pärssinen, A. (2023). Chip-to-chip interfaces for large-scale highly configurable mmWave phased arrays. IEEE Journal of Solid-State Circuits, 58(7), 1987–2004. https://doi.org/10.1109/JSSC.2023.3273502 https://doi.org/10.1109/JSSC.2023.3273502 Self-archived version Tiivistelmä
Tässä väitöskirjassa esitetään konsepteja ja erimerkkiratkaisuja joustavien ja uudelleenkonfiguroitavien keilanmuodostusjärjestelmien toteutukseen käyttämällä useita aliryhmiä ja lähetinvastaanottimia. Ensimmäinen arkkitehtuuri käyttää kaksiasteista keilanmuodostus-prosessia ja pystyy tuottamaan näin useita yhtäaikaisia keiloja, joiden välinen interferenssi voidaan minimoida toisessa asteessa joko välitaajuudella (IF) tai kantataajuudella, tai summata useita keiloja signaalikohinasuhteen parantamiseksi. Esitetty ratkaisu käyttää mmWave-alueella toimivia aliryhmiä, sekä integroituja IF-vastaanottimia, joiden avulla keiloja voidaan painottaa. Erityisesti työssä esitetään ratkaisu, jossa IBI:ä voidaan pienentää alikanava kerrallaan laajan yhteiskaistanleveyden saavuttamiseksi. Konseptia demonstroidaan laboratoriomittauksin ilmarajapinnan (OTA) yli käyttämällä 5G NR-aaltomuotoja. OTA-mittauksissa saavutetaan 34–37 dB yhteisisolaatio keilojen välille 50–100 MHz kaistanleveydellä, samalla säilyttäen hyvän virhevektorin arvon. Myös monen erillisen kantoaallon aggregoivassa skenaariossa saadaan erinomaiset tulokset. Työssä esitetään myös kalibrointimenetelmä keilojen välisen interferenssin nollaavien painokertoimien löytämiseen ilman signaalin demodulointia. Toteutettu IF-vastaanotinpiiri mahdollistaa myös suodatuksen ennen analogiadigitaali muunninta, hyvän lineaarisuuden sekä pienen kohinaluvun.
Työn toinen osio tarkastelee modulaarista aliryhmien yhdistämisarkkitehtuuria, jossa eri RFIC-piirien signaalit summataan käyttäen ruudukkopohjaista yhdistämisarkkitehtuuria. Ratkaisu perustuu piirien väliseen (C2C) rajapintaan, jossa signaalia voidaan reitittää eri RFIC-piirien läpi piirilevyllä (PCB) joustavasti ja näin toteuttaa suuria antennipaneeleita. Aliryhmiin toteutettu RFIC sisältää neljä C2C-rajapintaa, jotka toimivat 27 GHz taajuusalueella, kaksi 9 GHz välitaajuudella toimivaa C2C-rajapintaa, sekä kantataajuisen 400 MHz leveän IQ-osan. Arkkitehtuuri sisältää taajuuskonversiomoduulit pystyruoriin reitityksiin sekä signaalien summaukseen ja mahdollistaa erilaiset toimintamoodit signaalien yhdistämiseen, keilanmuodostukseen, sekä monen keilan yhtäaikaiseen tuottamiseen käyttämällä niin sanottua IF-reititysmatriisia. Työssä demonstroidaan osaa näistä moodeista yhdistämällä kaksi RFIC-aliryhmää PCB-toteutuksella. Mittaukset tehdään kapeakaistaisella siniaallolla sekä laajakaistaisella 5G NR-aaltomuodolla. Tulosten perustella voidaan todeta, että käytetty taajuuskonversiomoduuli tukee signaalien yhdistelyä ruudukkomaisessa reititysrakenteessa. Osajulkaisut Akbar, R., Klumperink, E. A. M., Tervo, N., Javed, M. Y., Stadius, K., Rahkonen, T., & Pärssinen, A. (2019). A wideband IF receiver module for flexibly scalable mmWave beamforming combining and interference cancellation. ESSCIRC 2019 - IEEE 45th European Solid State Circuits Conference (ESSCIRC), 213–216. https://doi.org/10.1109/ESSCIRC.2019.8902869 https://doi.org/10.1109/ESSCIRC.2019.8902869 Rinnakkaistallennettu versio Akbar, R., Shaheen, R. A., Rahkonen, T., Tze, C., Stadius, K., & Pärssinen, A. (2021). A 38.5-to-60.5 GHz LNA with wideband combiner supporting cartesian beamforming architecture. ESSCIRC 2021 - IEEE 47th European Solid State Circuits Conference (ESSCIRC), 199–202. https://doi.org/10.1109/ESSCIRC53450.2021.9567865 https://doi.org/10.1109/ESSCIRC53450.2021.9567865 Rinnakkaistallennettu versio Akbar, R., Klumperink, E. A. M., Tervo, N., Stadius, K., Rahkonen, T., & Pärssinen, A. (2023). A wideband IF receiver chip for flexibly scalable mmWave subarray combining and interference rejection. IEEE Transactions on Microwave Theory and Techniques, 71(12), 5482–5497. https://doi.org/10.1109/TMTT.2023.3279919 https://doi.org/10.1109/TMTT.2023.3279919 Rinnakkaistallennettu versio Sethi, A., Akbar, R., Hietanen, M., Aikio, J. P., Kursu, O., Jokinen, M., Leinonen, M. E., Rahkonen, T., & Pärssinen, A. (2023). Chip-to-chip interfaces for large-scale highly configurable mmWave phased arrays. IEEE Journal of Solid-State Circuits, 58(7), 1987–2004. https://doi.org/10.1109/JSSC.2023.3273502 https://doi.org/10.1109/JSSC.2023.3273502 Rinnakkaistallennettu versio Academic dissertation to be presented with the assent of the Doctoral Programme Committee of Information Technology and Electrical Engineering of the University of Oulu for public defence in Auditorium F101 of the Faculty of Biochemistry and Molecular Medicine (Aapistie 7), on 26 September 2024, at 12 noonAbstract
This thesis presents the concepts and implementation of subarrays that offer flexible, scalable, and reconfigurable solutions for building large-scale arrays. Large-scale multi-beam phased array systems often experience inter-beam interference caused by independent subarrays. This interference must be cancelled either in analog and/or digital domains. Implementing interference rejection in the analog domain can relax the ADC dynamic range and reduce the number of required ADC bits. However, in broadband systems like 5G, rejecting interference over a wide bandwidth is challenging due to radio channel properties and receiver chain non-idealities. This work introduces a wideband architecture for mmWave to cover multiple frequency bands for future communication scenarios. The receiver architecture involves a two-stage beamforming approach for the multi-beam system. In the first stage, the subarray mmWave front-end covers the 5G NR bands (25–62 GHz) and improves the SNR by combining signals from antenna elements, providing spatial filtering. In the second stage, the system aims to implement a flexible inter-beam interference cancellation (IBIC) or combining signals from independent subarrays by utilizing an IF receiver (IF-RX) chip. The IF-RX chip offers interference rejection or a wideband signal combining between the subarrays. The interference rejection performance was measured over-the-air (OTA) using 5G NR signals. The results showed a rejection of 34–37 dB for 50–100 MHz signals while meeting the EVM requirements of the 5G NR standards with good margins. Finally, the interference rejections over a 4 x 100 MHz carrier-aggregated 5G NR waveform was demonstrated.
This work also proposes building large-scale phased array panels using grid-based PCB routing using chip-to-chip (C2C) interfaces. The implemented subarray RFIC features four 27 GHz C2C interfaces, two 9 GHz C2C interfaces, and a complex BB with > 400 MHz single-sided bandwidth. C2C interfaces use a frequency conversion module for signal combining/distribution. The subarray RFIC's module enables different modes of operation through an IF routing matrix, providing high reconfigurability. The frequency conversion can support horizontal and vertical combinations of signals in a large-scale panel. It can be used for IBIC in the BB domain, demonstrating the practical applications of the proposed system design.Tiivistelmä
Tässä väitöskirjassa esitetään konsepteja ja erimerkkiratkaisuja joustavien ja uudelleenkonfiguroitavien keilanmuodostusjärjestelmien toteutukseen käyttämällä useita aliryhmiä ja lähetinvastaanottimia. Ensimmäinen arkkitehtuuri käyttää kaksiasteista keilanmuodostus-prosessia ja pystyy tuottamaan näin useita yhtäaikaisia keiloja, joiden välinen interferenssi voidaan minimoida toisessa asteessa joko välitaajuudella (IF) tai kantataajuudella, tai summata useita keiloja signaalikohinasuhteen parantamiseksi. Esitetty ratkaisu käyttää mmWave-alueella toimivia aliryhmiä, sekä integroituja IF-vastaanottimia, joiden avulla keiloja voidaan painottaa. Erityisesti työssä esitetään ratkaisu, jossa IBI:ä voidaan pienentää alikanava kerrallaan laajan yhteiskaistanleveyden saavuttamiseksi. Konseptia demonstroidaan laboratoriomittauksin ilmarajapinnan (OTA) yli käyttämällä 5G NR-aaltomuotoja. OTA-mittauksissa saavutetaan 34–37 dB yhteisisolaatio keilojen välille 50–100 MHz kaistanleveydellä, samalla säilyttäen hyvän virhevektorin arvon. Myös monen erillisen kantoaallon aggregoivassa skenaariossa saadaan erinomaiset tulokset. Työssä esitetään myös kalibrointimenetelmä keilojen välisen interferenssin nollaavien painokertoimien löytämiseen ilman signaalin demodulointia. Toteutettu IF-vastaanotinpiiri mahdollistaa myös suodatuksen ennen analogiadigitaali muunninta, hyvän lineaarisuuden sekä pienen kohinaluvun.
Työn toinen osio tarkastelee modulaarista aliryhmien yhdistämisarkkitehtuuria, jossa eri RFIC-piirien signaalit summataan käyttäen ruudukkopohjaista yhdistämisarkkitehtuuria. Ratkaisu perustuu piirien väliseen (C2C) rajapintaan, jossa signaalia voidaan reitittää eri RFIC-piirien läpi piirilevyllä (PCB) joustavasti ja näin toteuttaa suuria antennipaneeleita. Aliryhmiin toteutettu RFIC sisältää neljä C2C-rajapintaa, jotka toimivat 27 GHz taajuusalueella, kaksi 9 GHz välitaajuudella toimivaa C2C-rajapintaa, sekä kantataajuisen 400 MHz leveän IQ-osan. Arkkitehtuuri sisältää taajuuskonversiomoduulit pystyruoriin reitityksiin sekä signaalien summaukseen ja mahdollistaa erilaiset toimintamoodit signaalien yhdistämiseen, keilanmuodostukseen, sekä monen keilan yhtäaikaiseen tuottamiseen käyttämällä niin sanottua IF-reititysmatriisia. Työssä demonstroidaan osaa näistä moodeista yhdistämällä kaksi RFIC-aliryhmää PCB-toteutuksella. Mittaukset tehdään kapeakaistaisella siniaallolla sekä laajakaistaisella 5G NR-aaltomuodolla. Tulosten perustella voidaan todeta, että käytetty taajuuskonversiomoduuli tukee signaalien yhdistelyä ruudukkomaisessa reititysrakenteessa
Nourooz celebration in India
No full text<p>volume = {1}, number = {1}, author = {Dr.Ali Akbar Shah}, title = {Nourooz celebration in India }, publisher = {Saurabh Chandra}, journal = {SOCRATES}, ISSN 2347-6869 year = {2013}</p
Blaptostethus pluto Ballal & Akbar & Yamada & Wachkoo & Varshney 2018, comb. nov.
No full textBlaptostethus pluto (Distant, 1910) comb. nov. Triphleps pluto Distant, 1910: 307. SYNTYPE: ♀, India, Calcutta [= Kolkata] (BMNH). Type material examined: LECTOTYPE (present designation): ♀, ‘Type / H. T.’ [printed circle with red border], ‘under leaf / space of bamboo / Calcutta / 17-IX-09’ [handwritten], ‘Distant Coll. / 1911–383’ [printed], ‘Triphleps / pluto / Dist’ [Distant’s handwritten] (BMNH). Distribution in India. West Bengal: Kolkata (DISTANT 1910). General distribution. Endemic. Biology. According to the attached label, the type specimen was found under leaf space of bamboo, which is similar to the preferable habitat of Blaptostethus species. Taxonomy. While studying the syntype, it became obvious that this species should be transferred to Blaptostethus based on the following character combination: labium reaching mid coxae; profemur enlarged and with four long spines on anteroventral surface; ostiolar peritreme curved anteriorly and not reaching anterior margin of metapleuron.Published as part of Ballal, Chandish R., Akbar, Shahid Ali, Yamada, Kazutaka, Wachkoo, Aijaz Ahmad & Varshney, Richa, 2018, Annotated catalogue of the flower bugs from India (Heteroptera: Anthocoridae, Lasiochilidae), pp. 207-226 in Acta Entomologica Musei Nationalis Pragae 58 (1) on page 211, DOI: 10.2478/aemnp-2018-0018, http://zenodo.org/record/369921
A critical analysis of works of Razia Tujjar
No full text<p>volume = {1}, number = {1}, author = {Dr.Ali Akbar Shah}, title = {A critical analysis of works of Razia Tujjar }, publisher = {Saurabh Chandra}, journal = {SOCRATES}, ISSN 2347-6869 year = {2013}</p>
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