Journal articles on the topic 'IEEE 802.11 (Standard)'
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Anjali, Anjali, and Maninder Singh. "Performance Analysis of Proactive, Reactive and Hybrid MANET Routing Protocols on IEEE 802. 11 Standard." International Journal of Computer Applications 54, no. 12 (September 25, 2012): 1–8. http://dx.doi.org/10.5120/8615-2476.
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Wright, Don. "The History of the IEEE 802 Standard." IEEE Communications Standards Magazine 2, no. 2 (June 2018): 4. http://dx.doi.org/10.1109/mcomstd.2018.8412452.
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Bhaskar, Devendra, and Bhawna Mallick. "Performance Evaluation of MAC Protocol for IEEE 802. 11, 802. 11Ext. WLAN and IEEE 802. 15. 4 WPAN using NS-2." International Journal of Computer Applications 119, no. 16 (June 18, 2015): 25–30. http://dx.doi.org/10.5120/21153-4151.
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Bodson, Dennis. "ITU maintains IEEE 802, 16 wirelessman standard recommendations [Standards]." IEEE Vehicular Technology Magazine 3, no. 2 (June 2008): 19–38. http://dx.doi.org/10.1109/mvt.2008.923970.
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Qi, Long Fei, Zhi Hua Ning, and Le Nian He. "A Design of Powered Device Interface Chip under PoE System." Applied Mechanics and Materials 716-717 (December 2014): 1277–82. http://dx.doi.org/10.4028/www.scientific.net/amm.716-717.1277.
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This paper proposes a design of powered device interface chip compatible with communication protocol IEEE 802.at standard, for Ethernet control of power supply. This design has all the features IEEE 802.at standard requires, including the detection, classification, under-voltage lockout and inrush current control, support of not less than 25.5W of power. The circuit of the chip is designed with Hangzhou Silan BCD process technique. Specific features of the design are 140mA inrush-current-limiting, complementary-output-enable-signal, under-voltage, overvoltage, over temperature protection, an optional external power adapter input, IEEE 802.3at type2 display signals by new electrical equipment, as well as two-event classification logic implementation.
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Vohra, Rajan, R. S. Sawhney, Shipra Nayyar, and Sunandika Mann. "WLAN Performance Improvisation by Fine Tuning IEEE 802. 11 Parameters." International Journal of Computer Applications 43, no. 6 (April 30, 2012): 16–19. http://dx.doi.org/10.5120/6107-8319.
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Feng Zhang, T. C. Todd, Dongmei Zhao, and V. Kezys. "Power saving access points for IEEE 802-11 wireless network infrastructure." IEEE Transactions on Mobile Computing 5, no. 2 (February 2006): 144–56. http://dx.doi.org/10.1109/tmc.2006.25.
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Izhar, Mohd, and V. R. Singh. "Proposing of Collisions Free and Secure Network for IEEE 802. 11 WLAN." International Journal of Computer Applications 98, no. 5 (July 18, 2014): 22–26. http://dx.doi.org/10.5120/17179-7274.
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AhmadAnsari, Asrar, Md Jahangeer Alam, Zafrul Hasan, and Khwaja Mohammad Athar Siddique. "Performance Analysis of IEEE 802. 11 Ad Hoc Network with varying CWmin." International Journal of Applied Information Systems 6, no. 7 (January 8, 2014): 6–8. http://dx.doi.org/10.5120/ijais14-451073.
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A.Mohamed, M., W. B. Bahget, and S. S Mohamed. "A Performance Evaluation for Rate Adaptation Algorithms in IEEE 802. 11 Wireless Networks." International Journal of Computer Applications 99, no. 4 (August 20, 2014): 54–59. http://dx.doi.org/10.5120/17365-7884.
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K.Manocha, R., R. P. Agarwal, and Anoop Srivastava. "Modifications in IEEE 802. 11 to Prevent Collisions due to Interference in MANETs." International Journal of Computer Applications 50, no. 17 (July 28, 2012): 11–18. http://dx.doi.org/10.5120/7862-1112.
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R.Puranik, Swaroop, Vijayalakshmi M., and Linganagouda Kulkarni. "A Survey and Analysis on Scheduling Algorithms in IEEE 802. 16e (WiMAX) Standard." International Journal of Computer Applications 79, no. 12 (October 18, 2013): 1–10. http://dx.doi.org/10.5120/13790-1476.
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Fettouh, Abdessadeq, Najib El Kamoun, and Abdelaziz El Fazziki. "Performance Analysis of Ubiquitous Wireless Connectivity in a 3G/IEEE 802. 11 Integrated Network." International Journal of Computer Applications 59, no. 10 (December 18, 2012): 13–18. http://dx.doi.org/10.5120/9583-4061.
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Gupta, Vishal, and Mukesh Kumar Rohil. "Bit-Stuffing in 802. 11 Beacon Frame: Embedding Non-Standard Custom Information." International Journal of Computer Applications 63, no. 2 (February 15, 2013): 6–12. http://dx.doi.org/10.5120/10436-5115.
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Thangaraj, P., K. Sakthi Sudhan, and S. N. Sivanandam. "Perceptible MOS Factor Achieved during Voice Transmission in IEEE 802. 1Q Standard for Video Conferencing." International Journal of Computer Applications 55, no. 1 (October 20, 2012): 28–31. http://dx.doi.org/10.5120/8720-2591.
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I.A.Jabbar, A., and Emad A. Mohammed. "Utilizing TV Frequency Bands using Coalitional Game Theory according to the Standard of IEEE 802. 22." International Journal of Computer Applications 85, no. 6 (January 16, 2014): 10–16. http://dx.doi.org/10.5120/14844-3089.
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Sharma, Himanshu, Vibhav Kumar Sachan, and Syed Akhtar Imam. "Energy Efficiency of the IEEE 802. 15. 4 Standard in Wireless Sensor Networks: Modeling and Improvement Perspectives." International Journal of Computer Applications 58, no. 9 (November 15, 2012): 12–19. http://dx.doi.org/10.5120/9309-3540.
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V, Karthikeyan. "A Review on ZIGBEE in WSN." Indonesian Journal of Electrical Engineering and Computer Science 9, no. 1 (January 1, 2018): 29. http://dx.doi.org/10.11591/ijeecs.v9.i1.pp29-32.
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<p>Zigbee is fastidious for a group of abnormal state communication conventions. Zigbee is a run of the mill remote correspondence innovation. ZigBee uses low rate, low-control advanced radios taking into account an IEEE 802 standard for individual region systems. The change characterised by the ZigBee particular is proposed to be easier and less extravagant than the different WPANs remote single zone system, for example, Bluetooth. ZigBee is focused on radio-recurrence applications that compel a low in order rate, long battery life, and secure systems administration. ZigBee has a characterized rate of 250 kbps most appropriate for occasional or irregular information or a single sign transmission from a sensor or data gadget. It is a standard Open convention with no or unimportant permitting charges, chipsets accessible from various sources, remotely redesigned firmware, completely remote and low power, lattice systems administration to work on batteries, low support and bigger system size with standard based high security. </p>
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Kravchuk, Serhii, Liana Afanasieva, and Irina Kravchuk. "INVESTIGATION OF A MILLIMETER-WAVE RADIO LINK CHARACTERISTICS OF IEEE 802.11AD STANDARD IN URBAN AREAS." Information and Telecommunication Sciences, no. 1 (June 29, 2021): 5–11. http://dx.doi.org/10.20535/2411-2976.12021.5-11.
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Background. The explosive growth in the use of mobile broadband is significantly increasing the bandwidth requirements. Millimeter-wave spectrum is necessary for 5G networks to achieve data transfer rates of the order of Gb/s, in particular, for the provision of 3D video services, and the use radio modules for millimeter-wave frequencies as picocells in the streets will expand the capabilities of existing cellular networks and provide an increase in bandwidth. Therefore, the study of the characteristics of this spectrum is an urgent task today.
Objective. The purpose of the paper is to present the results of studying the characteristics of a millimeter-wave radio link to ensure high-speed user access to IP data transmission networks and the possibility of using the IEEE 802.11ad standard in open areas.
Methods. Structural and functional methods of constructing a millimeter-wave wireless network in urban areas based on IEEE 802.11ad standard hardware are investigated.
Results. The studies were carried out using a test bench with a point-to-point topology deployed in an urban environment (Kiev) with the line of sight without significant obstacles. The studies tested the possibility of using for millimeter-wave hardware technologies of the IEEE 802.11ad standard, which is used indoors, for applications in urban areas.
The use of a narrow beam antenna based on an antenna array allows adaptive control of the radiation pattern to bypass small obstacles blocking direct transmission, which allows reducing interference and receive/transmit a signal.
Conclusions. Experimental testing of the hardware capabilities of the IEEE 802.11ad standard has been carried out. Scenarios for constructing a millimeter-wave radio link under various weather conditions have been worked out.
Keywords: millimeter-wave; bandwidth; IEEE 802.11ad standard; 5G networks
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Asfandiyarova, М. Sh, and Т. P. Rybakova. "Economically valuable traits of collected sesame samples tested in the conditions of the Astrakhan region." Oil Crops 3, no. 183 (November 30, 2020): 71–74. http://dx.doi.org/10.25230/2412-608x-2020-3-183-71-74.
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In 2017–2018, we studied 45 sesame samples from the VIR collection in the experimental fields of the Cis-Caspian Agrarian Federal Scientific Center of the Russian Academy of Sciences (PAFNC RAN). According to temperature indicators, conditions of the years of a research were favorable for the growth and development of sesame. The sum of positive temperatures over the years was equal 3253.8 and 3249.7 °C, respectively. The length of the vegetative period of samples varied from 104 to 133 days. The earliest maturing samples (98–105 days) were KK-80 and 741 from Uzbekistan and K-802 from Tajikistan. As middle-early maturing (106–115 days) 11 samples were characterized, 25 samples were middle maturing (116–125 days), and five samples were late maturing (126–133 days). The most of the samples (33 samples) had seeds of average size (1000 seeds weight of 3.0–3.4 g) at the standard level (3.1 g). By a complex of economically valuable traits we selected 30 samples. The samples KK-883, 291, 171, 265, 468 from Uzbekistan, Azerbaijan, Turkey, Tunisia and Malta demonstrated the highest yield (3.0–4.3 t/ha). Very early maturing samples of sesame with high yields are of great interest and can be used in breeding work.
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Yadav, Sachin, Pieter Cardinael, Ming Zhao, Komal Vondkar, Uthayasankaran Peralagu, Alireza Alian, Raul Rodriguez, et al. "(Digital Presentation) Substrate Effects in GaN-on-Si Hemt Technology for RF FEM Applications." ECS Meeting Abstracts MA2022-02, no. 32 (October 9, 2022): 1208. http://dx.doi.org/10.1149/ma2022-02321208mtgabs.
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Abstract : GaN-on-Si HEMTs are emerging as a viable candidate for front-end-of-module (FEM) implementation in 5G and beyond user equipment and small-cell applications [1][2]. This is because GaN HEMTs based power amplifiers and switches have high power handling capability as well as excellent switch figure-of-merit (Ron × Coff). The cost-effective integration of GaN HEMTs on silicon substrates not only benefit from standard CMOS back-end-of-the-line processing but also wafer-level integration with Si-CMOS [1][3], enabling complex functionality and better performance than the standalone counterparts. An example can be a hybrid beamformer where GaN HEMTs can enable much smaller antenna array and therefore a smaller system form factor. For 5G wireless applications, standalone or co-integrated GaN HEMT based FEMs can lead to a more energy efficient and compact system as compared to standalone Si-CMOS technologies. However, for both amplifiers and switches, GaN-on-Si HEMTs present thermal management and substrate loss related issues. In this work, we study and model the impact of GaN HEMT integration on Si substrate on RF substrate losses and non-linearities. The growth of III-N buffer is the most significant factor in determining RF losses and harmonic distortion contribution from the substrate. High temperature annealing and ion implantation steps encountered during HEMT processing can also degrade the substrate performance. In addition, we demonstrate a direct co-relation between substrate losses and harmonic distortion analogous to silicon-on-insulator technologies (Figure 1). However, the bias dependence of RF losses and harmonics show a strong time dependence (memory effects) which is more complex to model [11]. We discuss the approaches to understand and model these effects. References: [1] H. W. Then et al, IEEE IEDM Tech. Dig., 2021, pp. 230-234. [2] B. Parvais et al, IEEE IEDM Tech. Dig., 2020, pp. 155-158. [3] W. E. Hoke et al, J. Vac. Sci. Technol. B 30, 02B101 (2012). [4] Drillet F et al, IJMWT 13, 517–522, 2021. [5] L. Cao et al, CSMANTECH conference Tech. Dig., 2020. [6] Roda Neve et al, IEEE TED, Vol. 59, NO. 4, pp. 924-932, 2012. [7] S. Yadav et al., in IEEE IEDM Tech. Dig., 2020, pp. 159-162. [8] Rack et al, ECS Trans., 92 (4), pp. 79-94, 2019. [9] Zhu et al, IEEE Microw. Wireless Compon. Lett., vol. 28, no. 8, pp. 377–379, 2018. [10] Raskin et al, IEEE SiRFIC, 2015. [11] P. Cardinael et al, IEEE ESSDERC 2021, pp. 303-306. Figure 1
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Czyżewski, Dariusz. "Comparison of luminance distribution on the lighting surface of power LEDs." Photonics Letters of Poland 11, no. 4 (December 31, 2019): 118. http://dx.doi.org/10.4302/plp.v11i4.966.
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This work presents luminance distributions across the surface of mid- and high-power diodes. The changes in luminance on diode surfaces following changes in the observation angle were verified. On the basis of the conducted tests, non-uniform luminance distribution on LED surface for diverse observation angles (including the axial direction) was observed. Moreover, it was concluded that luminance changes is not in line with the Lambert’s law. As the result of the research it was also concluded that alterations of the power-supply conditions do not exert any significant impact on the gradient of luminance changes on the surfaces of examined LEDs. Full Text: PDF ReferencesJ. Fan, J. Cao, Ch. Yu, Ch. Qian, X. Fan, G. Zhang, A design and qualification of LED flip Chip-on-Board module with tunable color temperatures, Microelectronics reliability, ISSN 0026-2714, Nº. 84, 2018, pp. 140-148, CrossRef K. Bonislawski, I. Fryc, The study on optical properties of LEDs used for vehicle control lighting, Przeglad Elektrotechniczny, 2012, ISSN 0033-2097, Vol. 88, Issue 3A, pp. 119-120 DirectLink T. Kawabata, Y. Ohno, Optical measurements of OLED panels for lighting applications, Journal of Modern Optics 60(14), 2013, pp. 1176-1186 CrossRef P. Pracki, U. Blaszczak, The issues of interior lighting on the example of an educational building adjustment to nZEB standard, IEEE Lighting Conference of the Visegrad Countries (Lumen V4), IEEE (17 November 2016) CrossRef P. Tabaka, Analysis of electrical parameters of prime set bulb equivalents suitable for dimming, Przeglad Elektrotechniczny, 2015, R. 91, No. 5, pp. 100-106, ISSN 0033-2097 CrossRef D. Czyżewski, The street lighting luminaires with LEDs. Przeglad Elektrotechniczny, 86, 2009, pp. 276-279 DirectLink C. C. Miller; Y. Zong; Y. Ohno, LED photometric calibrations at the National Institute of Standards and Technology and future measurement needs of LEDs, Proc. SPIE Vol. 5530, Fourth International Conference on Solid State Lighting; (2004) CrossRef D. Mozyrska Dorota; M. Wyrwas; I. Fryc, The determination of the LEDs colorimetric parameters, in the range of their operating temperature, Przeglad Elektrotechniczny, Vol. 88, Issue: 4A, 2012, pp. 232-234 CrossRef K. Baran, A. Różowicz, H. Wachta, S. Różowicz, D. Mazur, Thermal Analysis of the Factors Influencing Junction Temperature of LED Panel Sources, Energies, 12, 3941, 2019 CrossRef D. Czyżewski, Research on Luminance Distributions of Chip-On-Board Light-Emitting Diodes, Crystals 9(12), 645, 2019. CrossRef L. Zheng, Z. Guo, W. Yan, Y. Lin, Y. Lu, H.C. Kuo, Z. Chen, L. Zhu, T. Wu, Y. Gao, Research on a Camera-Based Microscopic Imaging System to Inspect the Surface Luminance of the Micro-LED Array. IEEE Access 6, 2018, 51329-51336. CrossRef S. Słomiński, Selected Problems in Modern Methods of Luminance Measurement of Multisource LED Luminaires. Light Eng. 24, 2016, pp. 45-50. DirectLink I. Fryc, P. Jakubowski, K. Kołacz, Analysis of optical radiation parameters of compact discharge HID lamps and LED COB modules used for illuminating shop windows, Przeglad Elektrotechniczny, 2017, R. 93, nr 11, pp. 186-189. CrossRef I. Fryc, Measurement techniques of optical LEDs properties performed with compliance conformity with CIE 127:2007 standard, Przeglad Elektrotechniczny, 2009,ISSN 0033-2097,Vol. 85,Issue:11,pp.317-319. DirectLink I. Fryc, T. Dimitrova-Grekow, An Automated System for Evaluation of the Quality of Light Sources, 2016 IEEE Lighting Conference of the Visegrad Countries (Lumen V4), IEEE (17 November 2016), CrossRef CIE 235:2019, Optical measurement of led modules and light engines, ISBN 978-3-902842-25-1, DOI: 10.25039/TR.235.2019. CrossRef D. Czyżewski, Investigation of COB LED luminance distribution, In Proceedings of the 2016 IEEE Lighting Conference of the Visegrad Countries (Lumen V4), IEEE (17 November 2016) CrossRef I. Rotscholl, K. Trampert; U. Krüger; F. Schmidt, Spectral near field data of LED systems for optical simulations, Proceedings SPIE Volume 11144,Phot. and Educ. in Measur. Sc. 2019, CrossRef
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Elshami, Mohamedraed, Hanan Abu Kmeil, Maymona Abu-Jazar, Ibtisam Mahfouz, Dina Ashour, Ansam Aljamal, Nada Mohareb, et al. "Breast Cancer Awareness and Barriers to Early Presentation in the Gaza-Strip: A Cross-Sectional Study." Journal of Global Oncology, no. 4 (December 2018): 1–13. http://dx.doi.org/10.1200/jgo.18.00095.
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Purpose Timely detection of breast cancer (BC) is important to reduce its related deaths. Hence, high awareness of its symptoms and risk factors is required. This study aimed to assess the awareness level of BC among females in Gaza. Materials and Methods A cross-sectional study was performed during September and October 2017 in Gaza, Palestine. Stratified sampling was used to recruit patients from four hospitals and seven high schools. The validated Breast Cancer Awareness Measure (BCAM) was used to assess confidence and behavior in relation to breast changes, awareness of BC symptoms and risk factors, barriers to seek medical help, and knowledge of BC screening. Women (age ≥ 18 years) visiting or admitted to any of the four hospitals, and female adolescents (age 15 to 17 years) in any of the seven schools, were recruited for face-to-face interviews to complete the BCAM. Results Of 3,055 women approached, 2,774 participants completed the BCAM questionnaire (response rate, 90.8%); 1,588 (57.2%) were adults, and 1,186 (42.8%) were adolescents. Of these, 1,781 (64.2%) rarely (or never) checked their breasts, and 909 (32.8%) were not confident to notice changes. In total, 1,675 (60.4%) were aware of the availability of BC screening programs. The overall mean ± standard deviation score for awareness of BC symptoms was 5.9 ± 2.9 of 11, and that of risk factors 7.5 ± 3.1 of 16. Feeling scared was the most reported barrier to seeking advice reported among women (n = 802; 50.2%), whereas feeling embarrassed was the most reported in adolescents (n = 745; 62.8%). Conclusion Awareness of BC symptoms, risk factors, and screening programs is suboptimal in Gaza. Educational interventions are necessary to increase public awareness of BC and to train local female breast surgeons to address barriers to early detection.
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Sebastian, Sujeesh, Felix Tandberg, Yang Liu, Deepak B. Raina, Magnus Tägil, Mattias Collin, and Lars Lidgren. "Extended local release and improved bacterial eradication by adding rifampicin to a biphasic ceramic carrier containing gentamicin or vancomycin." Bone & Joint Research 11, no. 11 (November 1, 2022): 787–802. http://dx.doi.org/10.1302/2046-3758.1111.bjr-2022-0101.r1.
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Aims There is a lack of biomaterial-based carriers for the local delivery of rifampicin (RIF), one of the cornerstone second defence antibiotics for bone infections. RIF is also known for causing rapid development of antibiotic resistance when given as monotherapy. This in vitro study evaluated a clinically used biphasic calcium sulphate/hydroxyapatite (CaS/HA) biomaterial as a carrier for dual delivery of RIF with vancomycin (VAN) or gentamicin (GEN). Methods The CaS/HA composites containing RIF/GEN/VAN, either alone or in combination, were first prepared and their injectability, setting time, and antibiotic elution profiles were assessed. Using a continuous disk diffusion assay, the antibacterial behaviour of the material was tested on both planktonic and biofilm-embedded forms of standard and clinical strains of Staphylococcus aureus for 28 days. Development of bacterial resistance to RIF was determined by exposing the biofilm-embedded bacteria continuously to released fractions of antibiotics from CaS/HA-antibiotic composites. Results Following the addition of RIF to CaS/HA-VAN/GEN, adequate injectability and setting of the CaS/HA composites were noted. Sustained release of RIF above the minimum inhibitory concentrations of S. aureus was observed until study endpoint (day 35). Only combinations of CaS/HA-VAN/GEN + RIF exhibited antibacterial and antibiofilm effects yielding no viable bacteria at study endpoint. The S. aureus strains developed resistance to RIF when biofilms were subjected to CaS/HA-RIF alone but not with CaS/HA-VAN/GEN + RIF. Conclusion Our in vitro results indicate that biphasic CaS/HA loaded with VAN or GEN could be used as a carrier for RIF for local delivery in clinically demanding bone infections. Cite this article: Bone Joint Res 2022;11(11):787–802.
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Gimenez-Guzman, Jose Manuel, Ivan Marsa-Maestre, David Orden, Susel Fernandez, and Marino Tejedor-Romero. "On the Benefits of Channel Bonding in Dense, Decentralized Wi-Fi 4 Networks." Wireless Communications and Mobile Computing 2022 (February 10, 2022): 1–11. http://dx.doi.org/10.1155/2022/8497585.
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Channel bonding is a technique first defined in the IEEE 802.11n standard to increase the throughput in wireless networks by means of using wider channels. In IEEE 802.11n (nowadays also known as Wi-Fi 4), it is possible to use 40 MHz channels instead of the classical 20 MHz channels. Although using channel bonding can increase the throughput, the classic 802.11 setting only allows for two orthogonal channels in the 2.4 GHz frequency band, which is not enough for proper channel assignment in dense settings. For that reason, it is commonly accepted that channel bonding is not suitable for this frequency band. However, to the best of our knowledge, there is not any accurate study that deals with this issue thoroughly. In this work, we study in depth the effect of channel bonding in Wi-Fi 4 dense, decentralized networks operating in the 2.4 GHz frequency band. We confirm the negative effect of using channel bonding in the 2.4 GHz frequency band with 11 channels which are 20 MHz wide (as in North America), but we also show that when there are 13 or more channels at hand (as in many other parts of the world, including Europe and Japan), the use of channel bonding yields consistent throughput improvements. For that reason, we claim that the common assumption of not considering channel bonding in the 2.4 GHz band should be revised.
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Ürgün, Satılmış, Halil Yiğit, and Seyedali Mirjalili. "Investigation of Recent Metaheuristics Based Selective Harmonic Elimination Problem for Different Levels of Multilevel Inverters." Electronics 12, no. 4 (February 20, 2023): 1058. http://dx.doi.org/10.3390/electronics12041058.
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Multilevel inverters (MLI) are popular in high-power applications. MLIs are generally configured to have switches reduced by switching techniques that eliminate low-order harmonics. The selective harmonic elimination (SHE) method, which significantly reduces the number of switching, determines the optimal switching moments to obtain the desired output voltage and eliminates the desired harmonic components. To solve the SHE problem, classical methods are primarily employed. The disadvantages of such methods are the high probability of trapping in locally optimal solutions and their dependence on initial controlling parameters. One solution to overcome this problem is the use of metaheuristic algorithms. In this study, firstly, 22 metaheuristic algorithms with different sources of inspiration were used to solve the SHE problem at different levels of MLIs, and their performances were extensively analyzed. To reveal the method that offers the best solution, these algorithms were first applied to an 11-level MLI circuit, and six methods were determined as a result of the performance analysis. As a result of the evaluation, the outstanding methods were SPBO, BMO, GA, GWO, MFO, and SPSA. As a result of the application of superior methods to 7-, 11-, 15-, and 19-level MLIs according to the IEEE 519—2014 standard, it has been shown that BMO outperforms in 7-level MLI, GA in 11-level MLI, and SPBO in 15- and 19-level MLIs in terms of THD, while in terms of output voltage quality, GA in 7-level MLI, BMO in 11-level MLI, GA and SPSA in 15-level MLI, and SPSA in 19-level MLI come forward.
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Kusznier, Jacek, and Wojciech Wojtkowski. "Spectral properties of smart LED lamps." Photonics Letters of Poland 12, no. 1 (March 31, 2020): 16. http://dx.doi.org/10.4302/plp.v12i1.978.
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Intelligent LED lamps are most often used in intelligent lighting installations. They frequently use one of two different ways to obtain white light. The first is the mixing of monochrome lights R, G and B. The second way is to mix the light of the blue diode with the yellow phosphor radiation. Adjusting the luminous flux in RGBW LED lamps causes greater changes in the position of the chromaticity point than in the case of CW WW LED lamps. In the case of big changes, this can lead to a visible change in the perceived color. Full Text: PDF References:https://re.jrc.ec.europa.eu/pvg_tools/en/tools.html [DirectLink]https://dateandtime.info/pl [DirectLink]J. Kusznier and W. Wojtkowski, "Impact of climatic conditions on PV panels operation in a photovoltaic power plant," IEEE, 2019 15th Selected Issues of Electrical Engineering and Electronics (WZEE), Zakopane, Poland, 2019, pp. 1-6 [CrossRef]J. Kusznier and W. Wojtkowski, "Impact of climatic conditions and solar exposure on the aging of PV panels," IEEE, 2019 15th Selected Issues of Electrical Engineering and Electronics (WZEE), Zakopane, Poland, 2019, pp. 1-6 [CrossRef]https://www.weatheronline.pl/weather/ [CrossRef]L.T. Sharpe, A. Jagla, W. Jägle, "A luminous efficiency function, V*(λ), for daylight adaptation", J. Vision 5(11), 948 (2012) [CrossRef]http://www.ee.co.za/article/integrating-sphere-data-sincere.html [DirectLink]Simunovic M. P., "On Seeing Yellow The Case for, and Against, Short-Wavelength Light-Absorbing Intraocular Lenses", Archives of Ophthalmology, vol. 130, no. 7, pp. 919-926, 2012 [CrossRef]I. Fryc, "Important parameters of multichannel spectroradiometer", Przeglad Elektrotechniczny R. 88(4a), pp. 230-231 (2012) [DirectLink]I. Fryc, "Measurement techniques of optical LEDs properties performed with compliance conformity with CIE 127:2007 standard", Przeglad Elektrotechniczny R. 85(11), pp. 317-319 (2009) [CrossRef]J. Kowalska, I. Fryc, "Colour rendition quality of typical fluorescent lamps determined by CIE Colour Fidelity Index and Colour Rendering Index", Przeglad Elektrotechniczny R. 95(7), pp. 94-97 (2019) [CrossRef]M. Gilewski, L. Gryko, A. Zajac, "Digital controlling system to the set of high power LEDs", Proc. of SPIE, 8902, 89021D, 2013 [CrossRef]M. Gilewski, "The ecological hazard of artificial lighting in greenhouses" Photonics Letters of Poland, vol. 11 Issue: 3 Pages: 87-89, 2019 [CrossRef]I. Fryc and T. Dimitrova-Grekow, "An automated system for evaluation of the quality of light sources," 2016 IEEE Lighting Conference of the Visegrad Countries (Lumen V4), Karpacz, 2016, pp. 1-4. [CrossRef]I. Fryc, "The spectral power distribution of LED driven by square shape pulses", Przeglad Elektrotechniczny R. 88(6), pp. 131-133 (2012) [DirectLink]I. Fryc, "LED's spectral power distribution under different condition of operating temperature and driving current", Przeglad Elektrotechniczny R. 86(10), pp. 187-189 (2010) [DirectLink]J. Kusznier, "Changes in the Spectral Power Distribution of Light Sources for Smart Lighting," IEEE, 2018 14th Selected Issues of Electrical Engineering and Electronics (WZEE), Szczecin, Poland, 2018, pp. 1-5 [CrossRef]
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Khan, Md Salman, and MM Alam. "Study on Sensitivity of Microphysics for the Simulation of Rainfall for the Month of May 2015 over Bangladesh using High Resolution WRF-ARW Model." Journal of Engineering Science 11, no. 1 (October 5, 2020): 43–60. http://dx.doi.org/10.3329/jes.v11i1.49546.
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In this research the Advanced Research WRF (ARW) model v3.8.1 has been used to simulate the rainfall of May 2015 all over Bangladesh. The model was configured in nested domain with 18 and 6 km horizontal grid spacing with 100 × 96 and 103 × 127 grids in the east-west and north-south directions, respectively with 30 vertical levels. The Lin et al., WSM6, Thomson, Morrison Double-Moment (M-2Mom), Stony Brook University (SBU), and WDM6 microphysics schemes coupling with Kain-Fritsch (KF) cumulus parameterization (CP) scheme have been used to simulate the monthly total rainfall, heavy rainfall, monthly rainy days and heavy rainy days for the month of May 2015 at all meteorological stations of Bangladesh. The simulated results are compared with the observed results of 33 meteorological stations of Bangladesh Meteorological Department (BMD) and Precipitation Estimation from Remotely Sensed Information using Artificial Neural Networks (PERSIANN) output. Relative standard deviation of all observed, PERSIANN and model simulated parameters have been analyzed and compared. The maximum monthly observed rain in May 2015 at Sylhet was 752 mm but WSM6, M-2Mom and WDM6 schemes have simulated 831, 788 and 742 mm for day 1 prediction; WSM6, WDM6 and SBU-Lin schemes have simulated 757, 916 and 981 mm for day 2 prediction and WSM6 and WDM6 schemes have simulated 741 and 925 mm for day 3 prediction, respectively and all other MPs have simulated much higher rainfall at domain (D1). The WDM6, M-2Mom and Lin et al. schemes have simulated 744, 807 and 923 mm for day 1 prediction, WSM6 and WDM6 schemes have simulated 714 and 877 mm for day 2 predictions and WSM6, SBU-Lin and Lin et al. schemes have simulated 802 and 913 and 998 mm, respectively for day 3 predictions at domain (D2). The relative standard deviation (RSD) has minimum at D1 and D2 for WDM6 scheme for day 1 prediction and WSM6 scheme for day 2 and day 3 predictions for the monthly total rainfall and heavy rainfall of May 2015. The results suggest that as the forecast time increased the amount of total rain and also heavy rain is increased. As a result RSD is also increased for all MPs. WDM6 scheme gives the better performance of rainfall and rainy days all over the country.
Journal of Engineering Science 11(1), 2020, 43-60
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Avudayappan, Naraina, and S. N. Deepa. "Congestion management in deregulated power system using hybrid cat-firefly algorithm with TCSC and SVC FACTS devices." COMPEL - The international journal for computation and mathematics in electrical and electronic engineering 35, no. 5 (September 5, 2016): 1524–37. http://dx.doi.org/10.1108/compel-11-2015-0423.
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Purpose The loading and power variations in the power system, especially for the peak hours have abundant concussion on the loading patterns of the open access transmission system. During such unconditional state of loading the transmission line parameters and the line voltages show a substandard profile, which depicts exaction of congestion management of the power line in such events. The purpose of this paper is to present an uncomplicated and economical model for congestion management using flexible AC transmission system (FACTS) devices. Design/methodology/approach The approach desires a two-step procedure, first by optimal placement of thyristor controlled series capacitor (TCSC) and static VAR compensator (SVC) as FACTS devices in the network; second tuning the control parameters to their optimized values. The optimal location and tuning of TCSC and SVC represents a hectic optimization problem, due to its multi-objective and constrained nature. Hence, a reassuring heuristic optimization algorithm inspired by behavior of cat and firefly is employed to find the optimal placement and tuning of TCSC and SVC. Findings The effectiveness of the proposed model is tested through simulation on standard IEEE 14-bus system. The proposed approach proves to be better than the earlier existing approaches in the literature. Research limitations/implications With the completed simulation and results, it is proved that the proposed scheme has reduced the congestion in line, thereby increasing the voltage stability along with improved loading capability for the congested lines. Practical implications The usefulness of the proposed scheme is justified with the computed results, giving convenience for implementation to any practical transmission network. Originality/value This paper fulfills an identified need to study exaction of congestion management of the power line.
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Ajewole, Titus, Adelowo Balogun, Muyideen Lawal, Omonowo Momoh, and Abdulsemiu Olawuyi. "A Genetic Algorithm Approach to Optimal Sizing and Placement of Distributed Generation on Nigerian Radial Feeders." Tanzania Journal of Engineering and Technology 41, no. 4 (December 31, 2022): 192–204. http://dx.doi.org/10.52339/tjet.v41i4.859.
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Mitigating power loss and voltage profile problems on radial distribution networks has been a major challenge to distribution system operators. While deployment of distributed generation, as compensators, has made a suitable solution option, optimum placement and sizing of the compensators has been a concern and it has thus been receiving great attention. Meta-heuristic algorithms have been found efficacious in this respect, yet the use of the algorithms in addressing problems of radial feeders is still comparatively low in Nigeria where analytical and numerical programming methods are common. Hence; the use of genetic algorithm to site and size distributed generator for real-time power loss reduction and voltage profile improvement on the Nigerian secondary distribution networks is presented. Backward-forward sweep load flow analysis, together with loss sensitivity factor, is deployed to identify the buses suitable for the installation of the distributed generation, while the algorithm is employed in estimating the optimum size. This approach is tested on the standard IEEE 15-bus system and validated using a Nigerian 11 kV feeder. The result obtained on the IEEE test system shows 183 kW loss using the compensator, as compared to 436 kW loss without the compensator; while on the Nigerian network the loss with the compensator was 4.99 kW, in comparison with no-compensation loss of 10.47kW. By the approach of this study, real power loss on the Nigerian feeder decreased by 52.3% together with energy cost reduction from N658,789.12 to N314,227.38. Likewise the minimum bus voltage magnitude and the voltage stability index of the network are improved to acceptable limits. This approach is therefore recommended as capable of strengthening the performance of the Nigerian radial distribution system.
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Shenoy, K. Latha, C. Gurudas Nayak, and Rajashekar P. Mandi. "Effect of partial shading in grid connected solar PV system with FL controller." International Journal of Power Electronics and Drive Systems (IJPEDS) 12, no. 1 (March 1, 2021): 431. http://dx.doi.org/10.11591/ijpeds.v12.i1.pp431-440.
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As conventional fossil fuel reserves shrink and the danger of climate change prevailing, the need for alternative energy sources is unparalleled. A smart approach to compensate the dependence on electricity generated by burning fossil fuels is through the power generation using grid connected PV system. Partial shading on PV array affects the quantity of the output power in photovoltaic (PV) systems. To extract maximum power from PV under variable irradiance, variable temperature and partial shading condition, various MPPT algorithms are used. Incremental conductance and fuzzy based MPPT techniques are used for maximum power extraction from PV array. Basically 11 kW Solar PV system comprising of PV array coupled with an Inverter through a dc-dc converter is considered for the analysis and output of the inverter is supplied to the load through the LCL filter. An Intelligent controller for maximum power point tracking of PV power is designed. Also, a fuzzy controller for VSC is developed to improve the system performance. The above proposed design has been simulated in the MATLAB/Simulink and analyzed the system performance under various operating conditions. Finally, the performance is evaluated with IEEE 1547 standard for showing the effectiveness of the system.
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Zhang, Jiawei, Josh Wilson, and Aimin Song. "(Invited, Digital Presentation) Oxide TFTs Based on Semiconductors and Semimetals." ECS Meeting Abstracts MA2022-02, no. 35 (October 9, 2022): 1263. http://dx.doi.org/10.1149/ma2022-02351263mtgabs.
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Oxide semiconductors have opened a new era for large-area, flexible and transparent applications. Despite the progresses, a bottleneck issue of oxide thin-film transistors (TFTs) is the instability either under bias stress or when used as a current source. Furthermore, the carrier mobility and current driving capability need to be improved for high-spec displays. It is still hugely challenging to overcome both issues using the conventional device structure and oxide semiconductor materials. Here, we review our recent work on novel oxide TFTs that show a few desirable properties. Rather than using an ohmic metal contact as the source electrode, a high work-function Schottky source contact enables depletion around the TFT source region, which results in intrinsic immunity to the negative bias illumination stress, no obvious short channel effect, and superb current saturation over a wide range of drain voltage1. The flat saturation current gives rise to an extremely high voltage gain reaching 23,000, which is, to the best of our knowledge, the highest gain ever achieved by a solid-state transistor to date. The threshold voltage is also found to remain stable under different drain voltages, in contrast to standard TFTs, which may be useful in larger-area displays where the drain voltages of the drive TFTs can differ2. Furthermore, the depletion provided by the Schottky source electrode allows utilizing semi-metal ITO to replace IGZO as the TFT channel layer, which significantly enhances the carrier mobility and current driving capability. Other related work may also be discussed in the talk including oxide Schottky diodes operating beyond 10 GHz3, oxide TFTs operating beyond 1 GHz4, significantly enhanced carrier mobility by self-assembled monolayer treatment5,6, and CMOS-like oxide-based logic circuits7,8. References Extremely high-gain source-gated transistors, J Zhang, J Wilson, G Auton, Y Wang, M Xu, Q Xin, A Song, Proceedings of the National Academy of Sciences 116 (11), 4843-4848 (2019) Comparative Study of Short-Channel Effects Between Source-Gated Transistors and Standard Thin-Film Transistors, Zhenze Wang, Li Luo, Yiming Wang, Jiawei Zhang, and Aimin Song, IEEE Transactions on Electron Devices, 69(2), 561 - 566 (2022). Flexible indium–gallium–zinc–oxide Schottky diode operating beyond 2.45 GHz, J Zhang, Y Li, B Zhang, H Wang, Q Xin, A Song, Nature communications 6 (1), 1-7 (2015). Amorphous-InGaZnO thin-film transistors operating beyond 1 GHz achieved by optimizing the channel and gate dimensions, Y Wang, J Yang, H Wang, J Zhang, H Li, G Zhu, Y Shi, Y Li, Q Wang, Qian Xin, Zhongchao Fan, Fuhua Yang, Aimin Song, IEEE Transactions on Electron Devices 65 (4), 1377-1382 (2018). Significant Performance Improvement of Oxide Thin‐Film Transistors by a Self‐Assembled Monolayer Treatment, W Cai, J Zhang, J Wilson, J Brownless, S Park, L Majewski, A Song, Advanced Electronic Materials 6 (5), 1901421 (2020). Significant performance enhancement of very thin InGaZnO thin-film transistors by a self-assembled monolayer treatment, W Cai, J Wilson, J Zhang, J Brownless, X Zhang, LA Majewski, A Song, ACS Applied Electronic Materials 2 (1), 301-308 (2020). Complementary integrated circuits based on p-type SnO and n-type IGZO thin-film transistors, Y Li, J Yang, Y Wang, P Ma, Y Yuan, J Zhang, Z Lin, L Zhou, Q Xin, Aimin Song, IEEE Electron Device Letters 39 (2), 208-211 (2017). Thin Film Sequential Circuits: Flip-Flops and a Counter Based on p-SnO and n-InGaZnO, Y Yuan, J Yang, Y Wang, Z Hu, L Zhou, Q Xin, A Song, IEEE Electron Device Letters 42 (1), 62-65 (2020).
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Mirshekali, Hamid, Rahman Dashti, Ahmad Keshavarz, and Hamid Reza Shaker. "Machine Learning-Based Fault Location for Smart Distribution Networks Equipped with Micro-PMU." Sensors 22, no. 3 (January 26, 2022): 945. http://dx.doi.org/10.3390/s22030945.
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Faults in distribution networks occur unpredictably, causing a threat to public safety and resulting in power outages. Automated, efficient, and precise detection of faulty sections could be a major element in immediately restoring networks and avoiding further financial losses. Distributed generations (DGs) are used in smart distribution networks and have varied current levels and internal impedances. However, fault characteristics are completely unknown because of their stochastic nature. Therefore, in these circumstances, locating the fault might be difficult. However, as technology advances, micro-phasor measurement units (micro-PMU) are becoming more extensively employed in smart distribution networks, and might be a useful tool for reducing protection uncertainties. In this paper, a new machine learning-based fault location method is proposed for use regardless of fault characteristics and DG performance using recorded data of micro-PMUs during a fault. This method only uses the recorded voltage at the sub-station and DGs. The frequency component of the voltage signals is selected as a feature vector. The neighborhood component feature selection (NCFS) algorithm is utilized to extract more informative features and lower the feature vector dimension. A support vector machine (SVM) classifier is then applied to the decreased dimension training data. The simulations of various fault types are performed on the 11-node IEEE standard feeder equipped with three DGs. Results reveal that the accuracy of the proposed fault section identification algorithm is notable.
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Fajri, Ahmad. "Studi Empiris terhadap Kinerja & Keamanan Wifi (Studi Kasus di Kota Depok)." Jurnal Teknologi Informasi dan Ilmu Komputer 6, no. 6 (December 2, 2019): 671. http://dx.doi.org/10.25126/jtiik.2019661832.
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<p>Pada tahun 2012, Kota Depok memperoleh penghargaan sebagai kota <em>Information and Communication Technology </em>(ICT) dari Kementerian Komunikasi dan Informatika. Salah satu parameter berkembangnya ICT di Kota Depok adalah meningkatnya jumlah pengguna internet dari berbagai sektor terutama perkantoran, hotel dan kampus dengan memanfaatkan jaringan <em>wifi </em>sebagai media transmisinya. Pada penelitian ini, kami melakukan audit terhadap keamanan jaringan <em>wifi</em> di Kota Depok dengan cara melakukan studi lapangan kinerja dan keamanan jaringan <em>wifi</em> menggunakan teknik <em>wardriving</em>. Studi ini mencakup sekitar 536 jaringan <em>wifi</em> di Jalan Margonda Depok. Hasil studi tersebut, kami menemukan bahwa 89% jaringan <em>wifi</em> menerapkan keamanan dengan<em> </em>menggunakan protokol WPA/WPA2, 1% menggunakan protokol WEP dan 10% bersifat terbuka. Kami juga menemukan sebanyak 20% jaringan <em>wifi</em> berada pada <em>channel</em> 1 dan 19% jaringan <em>wifi</em> berada pada <em>channel</em> 6 dan 11. <em>Channel </em>1, 6 dan 11 merupakan <em>channel</em> yang terbaik bagi penggunaan jaringan <em>wifi</em> karena terbebas dari interferensi jaringan <em>wifi </em>lainnya. Oleh karena itu penilaian kinerja dan keamanan jaringan <em>wifi </em>di Kota Depok dinilai sudah baik sesuai dengan standar IEEE 802.11i yaitu tentang peningkatan pengamanan pada jaringan <em>Wifi </em>menggunakan WPA2<em> </em>dan 802.11b tentang pengaturan <em>channel wifi </em>yang tidak menimbulkan interferensi.</p><p><em><strong>Abstract</strong></em></p><p><em>In 2012, Depok City was awarded as the city of Information and Communication Technology (ICT) from the Ministry of Communication and Information Technology.<em>One of the parameters of the development of ICT in Depok City is the increasing number of internet users from various sectors, especially offices, hotels and campuses by utilizing wifi networks as the transmission media. In this study, we conducted an audit of the security of wifi networks in Depok City by conducting field studies on the performance and security of wifi networks using wardriving techniques.</em><em>This study covers about 536 wifi networks on Margonda Street Depok. The results of the study, we found that 89% of wifi networks implement security using the WPA / WPA2 protocol, 1% using the WEP protocol and 10% are open. We also found that as much as 20% of the wifi networks are on channel 1 and 19% of wifi networks are on channels 6 and 11. Channel 1, 6 and 11 are the best channels for using wifi networks because they are free from interference from other wifi networks. Therefore, performance assessment and wifi network security in Depok City are considered to be good in accordance with the IEEE </em><em>802.11i standard which is about increasing security on Wifi networks using WPA2 and 802.11b regarding wifi channel settings that do not cause interference.</em></em></p>
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Kusznier, Jacek. "Influence of spectral properties of light sources on perceived and recorded images." Photonics Letters of Poland 13, no. 2 (June 30, 2021): 40. http://dx.doi.org/10.4302/plp.v13i2.1105.
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The text presents differences between the mechanism of seeing and recording images and potential sources of errors in color reproduction in recorded images. The measurements show that despite the relatively high values of indices (Ra, Rf i Rg) not all tested lamps are suitable for use on a photo set, as indicated by the value of TLCI index. The lighting requirements on a film set prioritize the quality of color reproduction, even at the expense of reducing the Luminous efficacy of a source (LES ) value. Full Text: PDF ReferencesL.T. Sharpe, A. Jagla, W. Jägle, "A luminous efficiency function, V*(λ), for daylight adaptation", J. Vision 5(11), 948 (2012) DirectLink K. Mangold, J.A. Shaw, M. Vollmer, The physics of near-infrared photography, Eur. J. Phys. 34 (2013), pp. 51-71 CrossRef Simunovic M. P., On Seeing Yellow The Case for, and Against, Short-Wavelength Light-Absorbing Intraocular Lenses, Archives of Ophthalmology, vol. 130, no. 7, pp. 919-926, 2012 CrossRef M. Gilewski, The ecological hazard of artificial lighting in greenhouses, Phot. Lett. Pol., vol. 11 Issue: 3, pp. 87-89, 2019. CrossRef M. Gilewski, The role of light in the plants world, Phot. Lett. Pol., vol. 11, no. 4, pp. 115-117, 2019 CrossRef I. Fryc and E. Czech Spectral correction of the measurement CCD array, Optical Engineering 41(10), pp.2402-2406 (2002). CrossRef L. Bellia, U. Blaszczak, F. Fragliasso, L. Gryko, Matching CIE illuminants to measured spectral power distributions: A method to evaluate non-visual potential of daylight in two European cities, Solar Energy, Volume 208, 2020, Pages 830-858 CrossRef J. Kusznier and W. Wojtkowski, Impact of climatic conditions on PV panels operation in a photovoltaic power plant, IEEE, 2019 15th Selected Issues of Electrical Engineering and Electronics (WZEE), Zakopane, Poland, pp. 1-6, 2019 CrossRef J. Kusznier and W. Wojtkowski, Impact of climatic conditions and solar exposure on the aging of PV panels, IEEE, 2019 15th Selected Issues of Electrical Engineering and Electronics (WZEE), Zakopane, Poland, pp. 1-6, 2019 CrossRef J. Fan, Y. Li, I. Fryc, C. Qian, X. Fan and G. Zhang, Machine-Learning Assisted Prediction of Spectral Power Distribution for Full-Spectrum White Light-Emitting Diode, in IEEE Photonics Journal, vol. 12, no. 1, pp. 1-18, Feb. 2020, Art no. 8200218, CrossRef M. Gilewski, L. Gryko, A. Zajac, Digital controlling system to the set of high power LEDs, Proc. of SPIE, 8902, 89021D, 2013 CrossRef J. Kusznier, W. Wojtkowski, Spectral properties of smart LED lamps, Phot. Lett. Pol., vol. 12, no. 1, pp. 16-18, 2020. CrossRef J. Kusznier, Changes in the Spectral Power Distribution of Light Sources for Smart Lighting, IEEE, 14th WZEE, pp. 1-5, 2018 CrossRef H. F. Ivey, Color and Efficiency of Luminescent Light Sources, J. Opt. Soc. Am. 53, 1185-1198 (1963) CrossRef F. Zhang, H. Xu, Z. Wang, Optimizing spectral compositions of multichannel LED light sources by IES color fidelity index and luminous efficacy of radiation, Appl. Opt. 56, 1962-1971 (2017) CrossRef T. W. Murphy Jr., Maximum spectral luminous efficacy of white light, Journal of Applied Physics 111, 104909 (2012) CrossRef Po-Chieh Hung and Jeffrey Y. Tsao, Maximum White Luminous Efficacy of Radiation Versus Color Rendering Index and Color Temperature: Exact Results and a Useful Analytic Expression, J. Display Technol. 9, 405-412 (2013) CrossRef V. M. Lisitsyn, V. S. Lukash, S. A. Stepanov, and Ju Yangyang , White LEDs with limit luminous efficacy, AIP Conference Proc 1698, 060008 (2016) CrossRef J. Kowalska, I. Fryc, Colour rendition quality of typical fluorescent lamps determined by CIE Colour Fidelity Index and Colour Rendering Index, Przeglad Elektrotechniczny R. 95(7), pp. 94-97, 2019 CrossRef I. Fryc, J. Fryc, A. Wasowski, "Rozważania o jakości oddawania barw źródeł światła, wyrażanej wskaźnikiem Ra (CRI), uwzględniające fizjologię widzenia oraz zagadnienia techniczno-prawne", Przeglad Elektrotechniczny R. 92(2), 218 (2016) CrossRef TECH 3353, Development of a "standard" television camera model implemented in the TLCI-2012, Source: FTV-LED, EBU, Geneva November 2012 DirectLink TECH 3354, Comparison of CIE colour metrics for use in the television lighting consistency index (TLCI-2012), Source: FTV-LED, EBU, Geneva November 2012 DirectLink TECH 3355, Method for the assessment of the colorimetric properties of luminaires the television lighting consistency index (TLCI-2012) and the television luminaire matching factor (TLMF-2013), Source: FTV-LED Geneva March 2017 DirectLink J. Kusznier, Mixing colours inside the optical fibre elements, Przeglad Elektrotechniczny, R 84(8), pp 182-185, 2008 DirectLink
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Sah, Ganesh Kumar, and Laxman Poudel. "Economic Analysis for Replacement of 11kV overhead Koteshwor Feeder by Underground Distribution System." Journal of Advanced College of Engineering and Management 6 (July 6, 2021): 33–41. http://dx.doi.org/10.3126/jacem.v6i0.38286.
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Cost effective, Aesthetic and Reliable energy supply is the need of any mankind. In this study, economic analysis for replacement of 11 kV overhead distribution feeder by 11kV underground cable is done with reference to Koteshwor Feeder under Baneshwor Distribution and Consumers Service. The reliability indices like SAIDI, SAIFI, ENS etc. is performed by using DigSilentPowerFactory software. The reliability of overhead distribution system is evaluated by using real system data system and similarly, historical IEEE standard data is used for underground distribution system. The reliability indices are compared for both distribution systems. Result shows that interruption in the overhead system is more than underground distribution system, the energy not supplied to the customer by overhead distribution system is also more than underground distribution system. The replacement cost estimation is performed by using Nepal Electricity Authority (NEA) unit rate and KEI industries quoted price for NEA underground project. The B/C ratio and Present Worth value for the 25-year period of useful life shows that the replacement of the existing overhead distribution system by underground distribution system is financial suitable and can be payback by revenue save from the Energy Not Supply (ENS) lower value of underground distribution system than overhead distribution system. In order to get the continuous of supply, esthetic and public safety in electricity distribution field one may have to bear initially extra cost to use underground distribution systems which finally get payback. Thus, in case of densely populated city like Kathmandu, underground distribution system is reasonable requirement for continuous supply, esthetic and public safety in electricity distribution filed.
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Sohtsinda, Hermann, Clency Perrine, Smail Bachir, Claude Duvanaud, and Christian Chatellier. "Amplifier-Aware Content-Based Precoder Design for Hierarchical Image Transmission over a Realistic MIMO-OFDM Channel." Journal of Circuits, Systems and Computers 28, no. 12 (November 2019): 1950209. http://dx.doi.org/10.1142/s0218126619502098.
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This paper proposes the design of a precoder in MIMO systems dedicated to JPEG Wireless (JPWL) (ISO/IEC 15444-11) image transmission which jointly takes into account the channel noise and the nonlinear distortions due to the high power amplifier (HPA) used in the transmitter. MIMO-OFDM (Orthogonal Frequency Division Multiplexing) systems dedicated to image transmission rely only on the Channel State Information (CSI) and the image content to design their precoding solutions. However, the nonlinear behavior of the HPA used at the front-end is not taken into account when designing the current precoders. In order to ensure the QoS of the transmitted image, a large level back-off is usually applied to avoid the nonlinear distortions generated by the HPA. In addition, the Input Back-off (IBO) value is statically chosen and does not depend on the other parameters of the link such as the instantaneous MIMO channel status, the modulation order and the scalability of the JPWL content. This may reduce both the global energy efficiency and the transmission quality of the Radio-Frequency (RF) link. Therefore, this work proposes a new precoding scheme to allocate the total available power while dynamically adjusting the optimal power IBO value according to the HPA parameters, the instantaneous channel status and the image content to be transmitted. Numerical results using a commercial HPA model under the IEEE 802.11n standard show that the proposed power allocation algorithm improves the visual quality of the received JPWL images compared to the state-of-the-art over a realistic radio channel model.
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Yin, Zhijun, Lina M. Sulieman, and Bradley A. Malin. "A systematic literature review of machine learning in online personal health data." Journal of the American Medical Informatics Association 26, no. 6 (March 25, 2019): 561–76. http://dx.doi.org/10.1093/jamia/ocz009.
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Abstract Objective User-generated content (UGC) in online environments provides opportunities to learn an individual’s health status outside of clinical settings. However, the nature of UGC brings challenges in both data collecting and processing. The purpose of this study is to systematically review the effectiveness of applying machine learning (ML) methodologies to UGC for personal health investigations. Materials and Methods We searched PubMed, Web of Science, IEEE Library, ACM library, AAAI library, and the ACL anthology. We focused on research articles that were published in English and in peer-reviewed journals or conference proceedings between 2010 and 2018. Publications that applied ML to UGC with a focus on personal health were identified for further systematic review. Results We identified 103 eligible studies which we summarized with respect to 5 research categories, 3 data collection strategies, 3 gold standard dataset creation methods, and 4 types of features applied in ML models. Popular off-the-shelf ML models were logistic regression (n = 22), support vector machines (n = 18), naive Bayes (n = 17), ensemble learning (n = 12), and deep learning (n = 11). The most investigated problems were mental health (n = 39) and cancer (n = 15). Common health-related aspects extracted from UGC were treatment experience, sentiments and emotions, coping strategies, and social support. Conclusions The systematic review indicated that ML can be effectively applied to UGC in facilitating the description and inference of personal health. Future research needs to focus on mitigating bias introduced when building study cohorts, creating features from free text, improving clinical creditability of UGC, and model interpretability.
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Samnaliev, M., V. Barut, S. Weir, J. Langham, S. Langham, X. Wang, B. Desta, and E. R. Hammond. "THU0550 HEALTH CARE UTILIZATION AND COSTS IN ADULTS WITH SYSTEMIC LUPUS ERYTHEMATOSUS IN THE UNITED KINGDOM: A REAL-WORLD OBSERVATIONAL RETROSPECTIVE COHORT STUDY." Annals of the Rheumatic Diseases 79, Suppl 1 (June 2020): 515–16. http://dx.doi.org/10.1136/annrheumdis-2020-eular.3765.
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Background:There is limited real-world evidence demonstrating the long-term direct costs associated with systemic lupus erythematosus (SLE) in the United Kingdom (UK).Objectives:To describe health care resource utilization and costs in adults with SLE in the UK over time and document costs by disease severity and type of encounter, including primary care, hospitalizations, outpatient visits, and prescription drugs.Methods:Patients aged ≥18 years with SLE were identified in the linked Clinical Practice Research Datalink – Hospital Episode Statistics database from January 1, 2005, to December 31, 2017. Patients were required to have data from ≥12 months before and after the index date, defined as the date of earliest diagnosis available in the data set. Patients were classified as having mild, moderate, or severe disease using an adapted claims-based algorithm.1Costs were calculated in 2017 UK pounds from the UK national health care system perspective. We estimated all-cause health care costs and incremental costs associated with each year of follow-up compared with a baseline year (3 years before index) using each patient as his or her own control and adjusting for age, sex, disease severity, and comorbid conditions.Results:Of the 802 patients identified, 369 (46.0%) had mild SLE, 345 (43.0%) had moderate SLE, and 88 (11.0%) had severe SLE. The mean all-cause cost increased in the 3 years before diagnosis and, in the first year after diagnosis, amounted to £7532 (standard deviation [SD] £9634). This cost varied by disease severity: mild SLE, £5221 (£8064); moderate SLE, £8323 (£9846); and severe SLE, £14,125 (£11,267) (Figure 1). Adjusted total mean annual increase in costs per patient in the overall study population was £4476 (95% confidence interval £3809–5143) greater in the year of diagnosis compared with the baseline year (P<0.0001), adjusted for age, sex, disease severity, and comorbid conditions. Primary care utilization was the leading component of costs during the first year after diagnosis, followed by prescriptions, outpatient care, and inpatient care (Figure 2). Information on biologic use in hospitals is unavailable in these data.Conclusion:The direct costs of health care for patients with SLE in the UK are substantial and persist over the years after diagnosis. Patients with moderate or severe SLE have higher all-cause costs over time compared with patients with mild SLE. Earlier diagnosis and treatment may reduce disease severity and occurrence of comorbidities, and the associated high health care costs.References:[1]Garris C, et al.J Med Econ. 2013;16:667–677.[2]Department of Health. NHS reference costs 2017/18.https://improvement.nhs.uk/resources/reference-costs/#rc1718;2018 [accessed May 11, 2019].Disclosure of Interests:Mihail Samnaliev Consultant of: AstraZeneca, Volkan Barut Employee of: AstraZeneca, Sharada Weir Consultant of: AstraZeneca, Julia Langham Consultant of: AstraZeneca, Sue Langham Consultant of: AstraZeneca, Xia Wang Employee of: AstraZeneca, Barnabas Desta Employee of: AstraZeneca, Edward R. Hammond Employee of: AstraZeneca
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Uy, Geoffrey L., Matthew S. Holt, Nicholas M. Fisher, Steven M. Devine, Michael H. Tomasson, John F. DiPersio, and Ravi Vij. "Bortezomib Alters Peripheral Blood Lymphocyte Subsets in Patients with Multiple Myeloma." Blood 106, no. 11 (November 16, 2005): 2387. http://dx.doi.org/10.1182/blood.v106.11.2387.2387.
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Abstract Bortezomib (VELCADE®) is a potent inhibitor of the proteasome which exerts its antimyeloma effect in part by blocking the activation of NF-κB. As NF-κB is critical for lymphocyte development and survival, there is great interest in harnessing the potential immunomodulatory effects of bortezomib. In murine hematopoietic transplantation models, bortezomib inhibits in vitro mixed lymphocyte responses and promotes the apoptosis of alloreactive T cells protecting against acute graft-versus-host disease. However, no data exists on the in vivo effects of bortezomib on human T cells. To characterize the effects of bortezomib on immune function, we profiled peripheral blood lymphocytes subsets and T cell associated cytokines in 39 patients with multiple myeloma. Two cycles of bortezomib 1.3 mg/m2 were administered by intravenous infusion on days 1, 4, 8, and 11 of a 21-day treatment cycle. The patients had received prior induction chemotherapy and would proceed to autologous transplant following treatment with bortezomib. Study population consists of 23 male and 16 female patients with the median age of 56 years (range 38–69). Myeloma characteristics at diagnosis were as follows (number of patients): IgG (28), IgA (10), light chain only (1), with stage I (1), II (12), or stage III (26) disease. Peripheral blood was collected at baseline (cycle 1, day 1) and at one week after the last dose of bortezomib (cycle 2, day 18) and analyzed for lymphocyte subsets by standard multicolor flow cytometry. Th1 and Th2 serum cytokines were measured at the same timepoints using a multiplexed cytometric bead array (BD Biosciences). Following treatment with bortezomib, no significant changes were detected in either Th1 or Th2 serum cytokine levels: IL-2 (p=0.116), TNF-alpha (p=0.854), IFN-gamma (p=0.070), IL-4 (p=0.240), IL-6 (0.236), IL-10 (0.151) as analyzed by Wilcoxon signed ranks test. Analysis of lymphocyte subsets using a paired student’s T-test demonstrated a 38% decrease in CD56+ NK cells (p=0.02) and a 26% increase in CD4/CD8 ratio (p=0.0006) which appears to be secondary to a decrease in CD8+ cytotoxic T-cells (p=0.054). (Table 1.) In conclusion, we observe an alteration of lymphocyte subsets following only two cycles of bortezomib. Further analysis of the effects of long term treatment with bortezomib is warranted. These studies may provide insights into the role of bortezomib as an immunomodulatory agent. Peripheral Blood Lymphocyte Subsets Pre-bortezomib (/mm 3 ) Post-bortezomib(/mm 3 ) Difference(/mm 3 ) P-value CD2 1446 1259 −187 0.085 CD3 1273 1160 −113 0.28 CD4 842 802 −40 0.54 CD8 412 337 −75 0.055 CD19 90 94 4 0.86 CD20 87 95 8 0.78 CD56 206 148 −58 0.022 CD4/CD8 ratio 2.53 3.19 0.66 0.0006
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Butt, Muhammad Ali, and Ryszard Piramidowicz. "Standard slot waveguide and double hybrid plasmonic waveguide configurations for enhanced evanescent field absorption methane gas sensing." Photonics Letters of Poland 14, no. 1 (March 31, 2022): 10. http://dx.doi.org/10.4302/plp.v14i1.1121.
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Herein, a numerical study on standard slot waveguide and double hybrid plasmonic waveguide based on a silicon-on-insulator platform is presented. The geometric parameters of both the waveguides are optimized for the operational wavelength of 3.39 μm (absorption line of methane gas) to obtain the maximum evanescent field ratio (EFR). By utilizing Lambert-Beer’s law, the gas sensing capability of both the waveguides is determined. It is found out that both the waveguides of length 100 μm offer high EFR resulting in the 3dB decay of the propagating mode power for the methane gas concentration of 20-22 % in the chamber. The study provides the foundation for the practical realization of compact and highly sensitive gas sensors. Full Text: PDF ReferencesJ.Y. Yo, Y.S. Kwon, J.W. Lee, J.S. Park, B.H. Rho, W. II. Choi. "Acute Respiratory Distress Due to Methane Inhalation", Tuberculosis and Respiratory Diseases 74, 120-123 (2013). CrossRef M. A. Butt, S. A. Degtyarev, S. N. Khonina and N. L. Kazanskiy. "An evanescent field absorption gas sensor at mid-IR 3.39 μm wavelength", Journal of Modern Optics 64, 1892-1897 (2017). CrossRef M. A. Butt, S. N. Khonina and N. L. Kazanskiy. "Modelling of Rib channel waveguides based on silicon-on-sapphire at 4.67 μm wavelength for evanescent field gas absorption sensor", Optik 168, 692-697, (2018). CrossRef M. A. Butt, S. N. Khonina and S. N. Kazanskiy. "Silicon on silicon dioxide slot waveguide evanescent field gas absorption sensor", Journal of Modern Optics 65, 174-178, (2017). CrossRef S. N. Khonina, N. L. Kazanskiy and M. A. Butt. "Evanescent Field Ratio Enhancement of a Modified Ridge Waveguide Structure for Methane Gas Sensing Application", IEEE Sensors Journal 20, 8469-8476 (2020). CrossRef M.Vlk, A. Datta, S. Alberti, H.D. Yallew, V. Mittal, G. S. Murugan, J. Jagerska. "Extraordinary evanescent field confinement waveguide sensor for mid-infrared trace gas spectroscopy", Light: Science & Applications 10, 26 (2021). CrossRef M.A. Butt, S.N. Khonina, N.L. Kazankiy. "Enhancement of evanescent field ratio in a silicon strip waveguide by incorporating a thin metal film", Laser Physics 29, 076202 (2019). CrossRef M. A. Butt, N. L. Kazanskiy and S. N. Khonina, "Highly integrated plasmonic sensor design for the simultaneous detection of multiple analytes", Current Applied Physics 20, 1274-1280 (2020). CrossRef T. Milde, M. Hoppe, H. Tatenguem, C. Assmann, W. Schade, J. Sacher. "Comparison of the spectral excitation behavior of methane according to InP, GaSb, IC, and QC lasers as excitation source by sensor applications", Applied Optics 58, C84 (2019). CrossRef N. L. Kazanskiy, S.N. Khonina, M.A. Butt. "Polarization-Insensitive Hybrid Plasmonic Waveguide Design for Evanescent Field Absorption Gas Sensor", Photonic Sensors 11, 279-290 (2021). CrossRef D. Popa, F. Udrea. "Towards Integrated Mid-Infrared Gas Sensors", Sensors 19, 2076 (2019). CrossRef S-W. Kang, K. Sasaki, H. Minamitani. "Sensitivity analysis of a thin-film optical waveguide biochemical sensor using evanescent field absorption", Applied Optics 32, 3544-3549 (1993). CrossRef
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Paolino, Jonathan D., Yael Flamand, Kristen E. Stevenson, Victoria Koch, Uma H. Athale, Peter D. Cole, Lisa M. Gennarini, et al. "Impact of Age, Body Surface Area, and Body Mass Index on Pegaspargase Toxicity and Pharmacokinetics: A Report from the DFCI ALL Consortium." Blood 138, Supplement 1 (November 5, 2021): 3396. http://dx.doi.org/10.1182/blood-2021-151313.
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Abstract Introduction: Increased toxicity with pegaspargase (PEG) in older and higher body mass index (BMI) patients (pts) with acute lymphoblastic leukemia (ALL) has recently led to dose capping practices. We assessed the influence of age, body surface area (BSA), and BMI on PEG-related toxicity and pharmacokinetics from two consecutive DFCI ALL Consortium trials without dose capping. Methods: Patient (pts) aged 1 to <19 years (DFCI 05-001) or 1 to <22 years (DFCI 11-001) with newly diagnosed ALL were eligible for enrollment. Those who received PEG (2500 IU/m 2) were included in this analysis. Pts received 1 dose of IV PEG on day 7 of Induction and every 2 weeks for 15 doses post-induction. Serum asparaginase activity (SAA), considered therapeutic at >0.1 IU/mL, was assessed 4, 11, 18, and 25 days after the Induction dose and nadir SAA was assessed before each Post-Induction dose. Asparaginase-related toxicities were prospectively assessed and graded by CTCAE version 3.0 (DFCI 05-001) or 4.0 (DFCI 11-001). Asparaginase toxicity for this analysis was defined as ≥1 of the following: pancreatitis, thrombosis, ≥grade 4 hyperbilirubinemia, ≥grade 4 hypertriglyceridemia. Allergy was analyzed separately (due to presumed dose independence). Height and weight at diagnosis were used for analyses. BMI categories were assigned using standard percentile ranges based on gender specific 2000 CDC growth charts. BSA was calculated using the Mosteller formula. Univariate analyses evaluated the relationship of age, BMI, and BSA with asparaginase toxicity. Comparisons of toxicity across BMI and BSA categories were performed using a Jonckheere-Terpstra test. Categorical comparisons for dichotomized BMI and BSA utilized a Fisher's exact test or chi square test. The relationships between BMI and BSA with toxicity were explored using multivariable models. Results: Between 4/2005-12/2011 802 pts enrolled on DFCI 05-001 and between 6/2012-6/2015 240 pts enrolled on DFCI 11-001. Both trials included random assignment of asparaginase formulation. In total 911 patients received pegaspargase during Induction and 351 during Post-Induction. During Induction, pts ≥15 years of age had higher asparaginase toxicity rates (17.1% vs 6.2%, p=0.0003) (Figure 1a). Toxicity differed significantly across BSA categories (<1.5 m 2, 1.5 to <2.0 m 2, ≥2.0 m 2, p= 0.007) with increased toxicity in those with BSA ≥2.0m 2 (22.7% vs. 6.8% for those <2.0 m 2, p = 0.016) (Figure 1b). Age was highly correlated with BSA (Pearson r = 0.93, p <0.0001). There was numerically higher toxicity in the BMI category of overweight vs. those underweight or normal weight (11.3% vs 6.5%) however this did not extend to the obese category, and overall, increasing BMI was not associated with statistically higher toxicity (p= 0.13, Figure 1c). Post-Induction, age ≥15 years was associated with increased asparaginase toxicity (57.1% vs 21%, p<0.0001) (Figure 1d). Toxicity differed significantly across BSA categories (p<0.0001) but was similar between BMI categories (p=0.19, Figure 1e-f). The impact of BSA was observed when dichotomized at thresholds of 1.5m 2 (54% vs. 19%, p<0.0001) and 2.0m 2 (70% vs. 23%, p=0.003) (Figure 1e). Considering only those ≥10 years of age, trends for BSA/BMI and toxicity were similar. There was no significant association between BMI or BSA and allergy. In multivariable analysis, BSA was a significant predictor of Post-Induction toxicity (OR 4.21, p<0.0001). Age was significant in the univariate setting (OR 1.14, p<0.0001) however due to high correlation with BSA, was not included with BSA in the multivariable model. Post-Induction, median nadir SAA levels were ≥0.1IU/mL for all BSA and age categories. Median SAA was similar or lower at all time-points for those ≥15 years of age compared with younger children. Median SAA for pts with BSA ≥1.5m 2 were similar or lower compared to those with BSA <1.5m 2 (Figure 2a-d). Conclusion: Age ≥15 years and BSA ≥2m 2 were each associated with significantly increased asparaginase toxicity. Older patients and those with higher BSA had similar or lower median SAA levels at all time-points. These results suggest that the differential toxicity seen in older patients and those with higher BSA is not explained by these patients having higher SAA levels. Prospective exploration of interventions to decrease toxicity in older patients and those with high BSA are needed. Figure 1 Figure 1. Disclosures Neuberg: Madrigal Pharmaceuticals: Other: Stock ownership; Pharmacyclics: Research Funding. Silverman: Takeda, Servier, Syndax, Jazz Pharmaceuticals: Current equity holder in publicly-traded company, Membership on an entity's Board of Directors or advisory committees.
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Kazanskiy, Nikolai Lvovich, and Muhammad Ali Butt. "One-dimensional photonic crystal waveguide based on SOI platform for transverse magnetic polarization-maintaining devices." Photonics Letters of Poland 12, no. 3 (September 30, 2020): 85. http://dx.doi.org/10.4302/plp.v12i3.1044.
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In this letter, a TM-polarization C-band pass one-dimensional photonic crystal strip waveguide (1D-PCSW) is presented. The waveguide structure is based on a silicon-on-insulator platform which is easy to realize using standard CMOS technology. The numerical study is conducted via 3D-finite element method (FEM). The transmittance and polarization extinction ratio (PER) is enhanced by optimizing the geometric parameters of the device. As a result, a TM polarized light can travel in the waveguide with ~2 dB loss for all C-band telecommunication wavelength window whereas the TE polarized light suffers a high transmission loss of >30 dB. As a result, a PER of ~28.5 dB can be obtained for the whole C-band wavelengths range. The total length of the proposed device is around 8.4 µm long including 1 µm silicon strip waveguide segment on both ends. Based on our study presented in this paper, several photonic devices can be realized where strict polarization filtering is required. Full Text: PDF ReferencesB. Wang, S. Blaize, R.S-Montiel, "Nanoscale plasmonic TM-pass polarizer integrated on silicon photonics", Nanoscale, 11, 20685 (2019). CrossRef D. Dai, J.E. Bowers, "Silicon-based on-chip multiplexing technologies and devices for Peta-bit optical interconnects", Nanophotonics, 3, 283 (2014). CrossRef M.A. Butt, S.N. Khonina, N.L. Kazanskiy, "Optical elements based on silicon photonics", Computer Optics, 43, 1079 (2019). CrossRef M.A. Butt, S.N. Khonina, N.L. Kazanskiy, "Compact design of a polarization beam splitter based on silicon-on-insulator platform", Laser Physics, 28, 116202 (2018). CrossRef M.A. Butt, S.N. Khonina, N.L. Kazanskiy, "A T-shaped 1 × 8 balanced optical power splitter based on 90° bend asymmetric vertical slot waveguides", Laser Physics, 29, 046207 (2019). CrossRef Q. Wang, S.-T. Ho, "Ultracompact TM-Pass Silicon Nanophotonic Waveguide Polarizer and Design", IEEE Photonics J., 2, 49 (2010). CrossRef C.-H. Chen, L. Pang, C.-H. Tsai, U. Levy, Y. Fainman, "Compact and integrated TM-pass waveguide polarizer", Opt. Express, 13, 5347 (2005). CrossRef S. Yuan, Y. Wang, Q. Huang, J. Xia, J. Yu, "Ultracompact TM-pass/TE-reflected integrated polarizer based on a hybrid plasmonic waveguide for silicon photonics", in 11th International Conference on Group IV Photonics (GFP) (IEEE, 2014), pp. 183-184. CrossRef X. Guan, P. Chen, S. Chen, P. Xu, Y. Shi, D. Dai, "Low-loss ultracompact transverse-magnetic-pass polarizer with a silicon subwavelength grating waveguide", Opt. Lett., 39, 4514 (2014). CrossRef A.E.- S. Abd-Elkader, M.F. O. Hameed, N.F. Areed, H.E.-D. Mostafa, and S.S. Obayya, "Ultracompact AZO-based TE-pass and TM-pass hybrid plasmonic polarizers", J.Opt. Soc. Am. B., 36, 652 (2019). CrossRef J. Li et al., "Photonic Crystal Waveguide Electro-Optic Modulator With a Wide Bandwidth", Journal of Lightwave Technology, 31, 1601-1607 (2013). CrossRef N. Skivesen et al., "Photonic-crystal waveguide biosensor", Optics Express, 15, 3169-3176 (2007). CrossRef S. Lin, J. Hu, L. Kimerling, K. Crozier, "Design of nanoslotted photonic crystal waveguide cavities for single nanoparticle trapping and detection", Optics Letters, 34, 3451-3453 (2009). CrossRef T. Liu, A.R. Zakharian, M. Fallahi, J.V. Moloney, M. Mansuripur, "Design of a compact photonic-crystal-based polarizing beam splitter", IEEE Photonics Technology Letters, 17, 1435-1437 (2005). CrossRef R. K. Sinha, Y. Kalra, "Design of optical waveguide polarizer using photonic band gap", Optics Express, 14, 10790 (2006). CrossRef
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Levi, Jelena, Timothy Perk, Lyna Huynh, Juliet Packiasamy, Serena Cheng, John Sunwoo, and A. Dimitrios Colevas. "45 AI-assisted whole-body assessment of immunotherapy response using [18F]F-AraG, a PET agent for activated T cells." Journal for ImmunoTherapy of Cancer 9, Suppl 2 (November 2021): A52. http://dx.doi.org/10.1136/jitc-2021-sitc2021.045.
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BackgroundPatterns of response to immunotherapy differ from traditional cytotoxic drugs, making clinical decisions concerning response evaluation more challenging. Radiological response criteria, such as iRECIST, updated to address response patterns unique to immunotherapeutics, focus only on changes in the tumor burden.1 An 18F labeled nucleoside analog, [18F]F-AraG was developed as a PET agent for imaging activated T cells,2–5 critical components of immune response and the common target of immunotherapies. Whole body assessment of [18F]F-AraG uptake that indicates presence of activated T cells might allow for analysis of complex immunologic processes and provide early indication of treatment response as well as off-target side effects. Here, we employ AIQ Solutions’ TRAQinform IQ software to analyze [18F]F-AraG scans and assess activation of T cells in head and neck squamous cell carcinoma (HNSCC) patients undergoing anti-PD-1 therapy.MethodsFour treatment-naïve HNSCC patients were imaged using [18F]F-AraG before and 2–3 weeks after a single dose of anti-PD-1 antibody. [18F]F-AraG PET scans of six healthy subjects were used to define areas of increased [18F]F-AraG uptake in patients. The regions of uptake in the baseline and on-treatment scans were registered and matched using articulated registration.6 7 Standardized uptake values, SUVmax, SUVmean and SUVtotal were extracted from all areas of tracer uptake in both scans and changes in signal calculated to assess therapy effects. The change in signal was analyzed in the context of the patient‘s clinical status and changes in T cell infiltration in the primary lesion when biopsy specimens were available.ResultsTRAQinform IQ whole body evaluation of [18F]F-AraG PET revealed heterogeneity in the signal range and extent of signal change both between different patients and between different areas of tracer uptake within the same patient (figure 1). The post-therapy whole-body [18F]F-AraG signal change trended with patients‘ outcome. The patients with areas where the signal disappeared or decreased post therapy, indicative of the lack of T cell activation, had shorter overall survival than the patients with areas with stable and increasing signal. The change in infiltration of activated T cells in the primary lesion tissue did not correspond to the patient survival, reflecting limitations of serial biopsy in evaluating therapy response.Abstract 45 Figure 1TRAQinform IQ assessment of the SUVmean [18F]F-AraG signal change in a HNSCC patient two weeks after a single dose of anti-PD-1 antibody. Quantification of the differences in the [18F]F-AraG uptake in the baseline and on-treatment scan revealed 17 hotspots with disappearing or decreasing signal, 22 hotpots with the stable signal and 11 hotspots with increasing or new signal post therapy.ConclusionsTRAQinform IQ analysis and quantification of [18F]F-AraG PET provides patient-level assessment of tracer uptake and may allow for better understanding of heterogeneity of T cell activation and potentially offer a more comprehensive evaluation of response to immunotherapy than the standard, tumor-centric, radiologic methods.ReferencesNishino M, et al. Monitoring immune-checkpoint blockade: response evaluation and biomarker development. Nat Rev Clin Oncol, 2017.Namavari M, et al. Synthesis of 2’-deoxy-2’-[18F]fluoro-9-beta-D-arabinofuranosylguanine: a novel agent for imaging T-cell activation with PET. Mol Imaging Biol 2011; 13(5):812–8.Ronald JA, et al. A PET imaging strategy to visualize activated T cells in acute graft-versus-host disease elicited by allogenic hematopoietic cell transplant. Cancer Res 2017; 77(11):2893–2902.Levi J, et al. Imaging of activated T cells as an early predictor of immune response to anti-PD-1 Therapy. Cancer Research 2019; 79(13):3455–3465.Levi J, et al. (18)F-AraG PET for CD8 profiling of tumors and assessment of immunomodulation by chemotherapy. J Nucl Med 2021; 62(6):802–807.Yip S, T Perk, and R Jeraj, Development and evaluation of an articulated registration algorithm for human skeleton registration. Phys Med Biol 2014; 59(6):1485–99.Yip S. and R Jeraj. Use of articulated registration for response assessment of individual metastatic bone lesions. Phys Med Biol 2014; 59(6): 1501–14.Ethics ApprovalThe study was approved by Stanford University Ethics Board, approval number 40425.
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Rathore, Rituraj S., and Viranjay M. Srivastava. "(Digital Presentation) Influence of Fin Width Modulation on Nanoscale FinFET." ECS Meeting Abstracts MA2022-02, no. 36 (October 9, 2022): 1326. http://dx.doi.org/10.1149/ma2022-02361326mtgabs.
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ABSTRACT In the present research work, the influence of Fin width thickness variation on the electrical performance parameters have been performed for the FinFET device. Various Fin angle (i.e., θ) have been considered to analyze the effect of Fin thickness variations. All the analyzed results have been compared with the ideal FinFET (i.e., θ = 0) device to observe the effect of angle variation on threshold voltage (VTH), Transconductance (gm), Gate current (IG) and Drain Induced Barrier Lowering (DIBL). In addition, the impact of Fin width thickness variations has been used to realize the inverter Voltage Transfer Characteristics (VTC). The characteristics comparison reveals that including the effect of Fin width improves the device performance of FinFET devices. INTRODUCTION The FinFET device has been considered as a future candidate for VLSI circuit design and manufacturing. Compared with planar technology, the FinFET device shows reduced Short Channel Effects (SCEs) and improved electrostatic control. However, device variability poses a severe threat to downscaling FinFET dimensions in the nanoscale regime because non-uniformity has a significant influence on short-channel devices [1, 2]. In the fabrication of FinFET devices, the effect of the nonrectangular Fin shape must be carefully considered because the Fin thickness of the fabricated FinFET differs from the ideal shape. It is found that it is difficult to achieve a perfect rectangular Fin shape due to Line Edge Roughness (LER) and Line Width Roughness (LWR) [3]. In previous research works, authors considered the variations introduced in the vertical direction of the Fin while ignoring the fact that Fin width fluctuates in the lateral direction too [4]. This lateral Fin fluctuation introduces significant errors during performance parameter analysis. Therefore, this present research work focused on fluctuations in the Fin in the lateral direction. Here, the effects of non-uniformity on electrical performance parameters such as VTH, gm, IG and DIBL have been analyzed and compared with the ideal FinFET device. Furthermore, the impact of these variations is incorporated into the realization of inverter VTC characteristic. DEVICE DESIGN AND RESULT ANALYSIS Fig. 1(a) shows the full 3D view of the FinFET device. The doping concentration of the Source/Drain (S/D) region is maintained at 1×1020 cm-3 . Here, channel thickness (Tsi ) and gate oxide thickness (tox ) are 8 nm and 1 nm, respectively. Titanium Nitride (TiN) metal has been employed as the gate electrode because TiN shows low resistivity, high melting, thermal stability, and compatibility with the standard CMOS process [5]. To analyze the effects of fin width variation on the performance parameters of FinFET, the non-uniformity has been shown in Fig. 1(b). Here, Tsi fluctuations are approximated as a linear slope, making an angle (θ) to X-axis in the range of -70 to 70 to exaggerate the width variation effects. A Positive angle means the drain area is more significant compared to the source area and vice versa. Fig. 2 displays the VTH and DIBL variations against the Fin width variation. It has been realized that for Fin thickness variation from -70 to +70 there is a shift in threshold voltage (VTH ) of 6.12% and 4.08%, respectively. However, it is also observed that the non-uniform Fin width improves the DIBL for the FinFET device. This is due to the modulation of the effective S/D area with the channel region. CONCLUSIONS AND FUTURE ASPECTS The effect of Fin width thickness variation is increasing as the feature size of the FinFET device reduces. This work realized that the linear variation in the overall Fin width thickness introduces comparable variations in electrical performance parameters for FinFET device. For instance, there is a significant improvement in DIBL for Fin thickness variation from -70 to +70 because these variations are directly correlated to the Fin thickness reduction. These insights will allow technologists and designers to capture a valid performance characteristic for Fin width variations effects to meet future design challenges in the nanometer regime. REFERENCES [1] A Khakifirooz, IEEE Trans. Elect. Dev., vol. 55(6), pp. 1401-1408, 2008. [2] RS Rathore, IEEE 4th International Conference on Signal Processing, Computing and Control (ISPCC), Solan, 2017, pp. 377-380. [3] RS Rathore, Superlattices and Microstructures, vol. 113, pp. 213-227, 2018. [4] X Wu, IEEE Trans. Elect. Dev., vol. 52(1), pp. 63-68,2005. [5] AR Brown, IEEE Trans. Elect. Dev., vol. 54(11), pp. 3056-3063, 2007. Figure 1
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Jaremko, J. L., B. Felfeliyan, A. Rakkunedeth, B. Thejeel, V. Quinn-Laurin, M. Østergaard, P. G. Conaghan, R. Lambert, J. Ronsky, and W. P. Maksymowych. "AB0594 IMPROVING OSTEOARTHRITIS CARE BY AUTOMATIC MEASUREMENT OF HIP EFFUSION USING AI." Annals of the Rheumatic Diseases 80, Suppl 1 (May 19, 2021): 1334.1–1334. http://dx.doi.org/10.1136/annrheumdis-2021-eular.2196.
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Background:Osteoarthritis (OA) is the commonest disease affecting hip joints and has high prevalence across various age groups [1,2]. Effusion is a hallmark of OA and could represent a potential target for therapy [3–5]. Positive correlations of effusion to clinical outcomes are not well established, partly due to variability in manual assessment. Voxel-based volume quantification could reduce this variability [6].Objectives:We examine the inter-observer agreement of manual assessment of voxel-based effusion volume from coronal STIR MRI sequences at two time points and examine the feasibility of using Artificial Intelligence (AI) for standalone volume assessment.Methods:Our algorithm is based on Mask R-CNN [7] and was trained on labeled effusion regions in MRI slices from 68 patients with hip osteoarthritis. For validation, 2 human readers measured effusion from MRI STIR sequences of 25 patients at baseline and at 8 weeks follow-up. AI was used to measure effusion volume as an independent reader. Agreement between human readers and AI was assessed using absolute difference in volume (DV), Coefficients of Variation (CoV) and intraclass correlation coefficient (ICC).Results:Effusion regions detected by AI closely correlated with manual segmentation (Figure 1) for all samples. Differences in volumes measured by each pair of readers are summarized in Table 1. Agreement was excellent between human readers (ICC=0.99) and for each reader vs AI (ICC = 0.85-0.87).Figure 1.Mask overlays of regions of joint fluid detected by human readers (green, column 2) and AI (red, column 3) from 3 different patients. Raw MRI images are shown in column 1.Table 1.Comparison of volumes measured in cubic millimeters and agreement between each pair of readers (with AI as the 3rd reader)Volumes measured by readersAgreement between reader pairsReaderOverall VolumeMean ± Standard DeviationReader PairDifference in VolumeMean ± Standard DeviationCoVICCReader 16943 ± 5845Reader 1-21127 ± 9000.210.99 [0.98, 1.0]Reader 27638 ± 5619Reader 1-AI3311 ±16430.350.87 [0.7, 0.94]AI11014 ± 4454Reader 2-AI4151 ± 49860.270.85 [0.66,0.94]Conclusion:Initial results of automatic effusion measurement using AI show high agreement with human experts. This has potential to reduce variability and save expert time in OA MRI assessment, and to lead to improved OA care.References:[1]Sharif B, Garner R, Hennessy D, Sanmartin C, Flanagan WM, Marshall DA. Productivity costs of work loss associated with osteoarthritis in Canada from 2010 to 2031. Osteoarthritis Cartilage. 2017 Feb;25(2):249–58.[2]Sharif B, Kopec J, Bansback N, Rahman MM, Flanagan WM, Wong H, et al. Projecting the direct cost burden of osteoarthritis in Canada using a microsimulation model. Osteoarthritis Cartilage. 2015 Oct;23(10):1654–63.[3]Loeuille D, Chary-Valckenaere I, Champigneulle J, Rat A-C, Toussaint F, Pinzano-Watrin A, et al. Macroscopic and microscopic features of synovial membrane inflammation in the osteoarthritic knee: correlating magnetic resonance imaging findings with disease severity. Arthritis Rheum. 2005 Nov;52(11):3492–501.[4]Fernandez-Madrid F, Karvonen RL, Teitge RA, Miller PR, An T, Negendank WG. Synovial thickening detected by MR imaging in osteoarthritis of the knee confirmed by biopsy as synovitis. Magn Reson Imaging. 1995;13(2):177–83.[5]Atukorala I, Kwoh CK, Guermazi A, Roemer FW, Boudreau RM, Hannon MJ, et al. Synovitis in knee osteoarthritis: a precursor of disease? Ann Rheum Dis. 2016 Feb;75(2):390–5.[6]Quinn-Laurin V, Thejeel B, Chauvin NA, Brandon TG, Weiss PF, Jaremko JL. Normal hip joint fluid volumes in healthy children of different ages, based on MRI volumetric quantitative measurement. Pediatr Radiol. 2020 Oct;50(11):1587–93.[7]He K, Gkioxari G, Dollár P, Girshick R. Mask r-cnn. In: Proceedings of the IEEE international conference on computer vision. openaccess.thecvf.com; 2017. p. 2961–9.Acknowledgements:Jacob Jaremko is supported by the AHS Chair in Diagnostic Imaging at the University of Alberta. Medical Imaging Consultants (MIC) funds musculoskeletal radiology fellowships for Vanessa Quinn-Laurin at the University of Alberta, and provides Jacob Jaremko and Robert Lambert with protected academic time. Banafshe Felfeliyan is supported by an Alberta Innovates Graduate Student Scholarship for Data-Enabled Innovation.Disclosure of Interests:None declared.
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Albuquerque, Monica Soares de, Armiliana Soares Nascimento, Cácio Lopes Mendes, Leonardo José Rodrigues de Oliveira, Marília de Lima Soares, Maria Catarina Lago, Angela do Nascimento, Douglas Felipe de Lima e. Silva, and Rodivan Braz. "Endodontic retreatment due to secondary periapical injury: case report." ARCHIVES OF HEALTH INVESTIGATION 9, no. 6 (June 8, 2020): 503–6. http://dx.doi.org/10.21270/archi.v9i6.4959.
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Pulp diseases commonly happens because of the actions of bacteriological factors and show their characteristic signs and symptoms over the time. With pulp necrosis, a degenerative process starts and when there is no early treatment, it is possible to occur periapical lesions as a result of aggression to the pulp. In cases of periapical secondary lesions, clinical signs and symptoms persist and are related to secondary infection due to persistent bacterial contamination, also to operative factors, inadequate obturation or poor coronary restoration. This study aimed to report a case of endodontic retreatment and clinical and radiographic follow-up for 8 years, of chronic periapical abscess case, in which after retreatment, clinical signs and symptoms are no longer observed and bone neoformation is noticed.
Descriptors: Periapical Diseases; Endodontics; Periapical Abscess.
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Kuo, C. F., S. Miao, K. Zheng, L. Lu, C. I. Hsieh, C. Lin, and T. Y. Fan. "OP0301 PREDICTION OF LOW BONE MINERAL DENSITY AND FRAX SCORE BY ASSESSING HIP BONE TEXTURE WITH DEEP LEARNING." Annals of the Rheumatic Diseases 79, Suppl 1 (June 2020): 187.2–187. http://dx.doi.org/10.1136/annrheumdis-2020-eular.5916.
Full textAbstract:
Background:Osteoporosis is a widespread health concern associated with an increased risk of fractures in individuals with low bone mineral density (BMD). Dual-energy x-ray absorptiometry (DXA) is the gold standard to measure BMD, but methods based on the assessment of plain films, such as the digital radiogrammetry,1are also available. We describe a novel approach based on the assessment of hip texture with deep learning to estimate BMD.Objectives:To compare the BMD estimated by assessing hip texture using a deep learning model and that measured by DXA.Methods:In this study, we identified 1,203 patients who underwent DXA of left hip and hip plain film within six months. The dataset was split into a training set with 1,024 patients and a testing set with 179 patients. Hip images were obtained and regions of interest (ROI) around left hips were segmented using a tool based on the curve Graph Convolutional Network. The ROIs are processed using a Deep Texture Encoding Network (Deep-TEN) model,2which comprises the first 3 blocks of Residual Network with 18 layers (ResNet-18) model followed by a dictionary encoding operator (Figure 1). The encoded features are processed using a fully connected layer to estimate BMD. Five-fold cross-validation was conducted. Pearson’s correlation coefficient was used to assess the correlation between predicted and reference BMD. We also test the performance of the model to identify osteoporosis (T-score ≤ -2.5)Figure 1.Schematic representation of deep learning models to extract and encode texture features for estimation of hip bone density.Results:We included 151 women and 18 men in the testing dataset (mean age, 66.1 ± 1.7 years). The mean predicted BMD was 0.724 g/cm2compared with the mean BMD measured by DXA of 0.725 g/cm2(p = 0.51). Pearson’s correlation coefficient between predicted and true BMD was 0.88. The performance of the model to detect osteoporosis/osteopenia was shown in Table 1. The positive predictive value was 87.46% for a T-score ≤ -1 and 83.3% for a T-score ≤ -2.5. Furthermore, the mean FRAX® 10-year major fracture risk did not differ significantly between scores based on predicted (6.86%) and measured BMD (7.67%, p=0.52). The 10-year probability of hip fracture was lower in the predicted score (1.79%) than the measured score (2.43%, p = 0.01).Table 1.Performance matrices of the deep texture model to detect osteoporosis/osteopeniaT-score ≤ -1T-score ≤ -2.5Sensitivity91.11%(95% CI, 83.23% to 96.08%)33.33%(95% CI, 17.29% to 52.81%)Specificity86.08%(95% CI, 76.45% to 92.84%)98.56%(95% CI, 94.90% to 99.83%)Positive predictive value88.17%(95% CI, 81.10% to 92.83%)83.33%(95% CI, 53.58% to 95.59%)Negative predictive value89.47%(95% CI, 81.35% to 94.31%)87.26%(95% CI, 84.16% to 89.83%)Conclusion:This study demonstrates the potential of the bone texture model to detect osteoporosis and to predict the FRAX score using plain hip radiographs.References:[1]Zandieh S, Haller J, Bernt R, et al. Fractal analysis of subchondral bone changes of the hand in rheumatoid arthritis. Medicine (Baltimore) 2017;96(11):e6344.[2]Zhang H, Xue J, Dana K. Deep TEN: Texture Encoding Network. The IEEE Conference on Computer Vision and Pattern Recognition (CVPR) 2017:708-17.Disclosure of Interests:None declared
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Rahmani, Babak, Ilker Oguz, Ugur Tegin, Jih-liang Hsieh, Demetri Psaltis, and Christophe Moser. "Learning to image and compute with multimode optical fibers." Nanophotonics 11, no. 6 (January 21, 2022): 1071–82. http://dx.doi.org/10.1515/nanoph-2021-0601.
Full textAbstract:
Abstract Multimode fibers (MMF) were initially developed to transmit digital information encoded in the time domain. There were few attempts in the late 60s and 70s to transmit analog images through MMF. With the availability of digital spatial modulators, practical image transfer through MMFs has the potential to revolutionize medical endoscopy. Because of the fiber’s ability to transmit multiple spatial modes of light simultaneously, MMFs could, in principle, replace the millimeters-thick bundles of fibers currently used in endoscopes with a single fiber, only a few hundred microns thick. That, in turn, could potentially open up new, less invasive forms of endoscopy to perform high-resolution imaging of tissues out of reach of current conventional endoscopes. Taking endoscopy by its general meaning as looking into, we review in this paper novel ways of imaging and transmitting images using a machine learning approach. Additionally, we review recent work on using MMF to perform machine learning tasks. The advantages and disadvantages of using machine learning instead of conventional methods is also discussed. Methods of imaging in scattering media and particularly MMFs involves measuring the phase and amplitude of the electromagnetic wave, coming out of the MMF and using these measurements to infer the relationship between the input and the output of the MMF. Most notable techniques include analog phase conjugation [A. Yariv, “On transmission and recovery of three-dimensional image information in optical waveguides,” J. Opt. Soc. Am., vol. 66, no. 4, pp. 301–306, 1976; A. Gover, C. Lee, and A. Yariv, “Direct transmission of pictorial information in multimode optical fibers,” J. Opt. Soc. Am., vol. 66, no. 4, pp. 306–311, 1976; G. J. Dunning and R. Lind, “Demonstration of image transmission through fibers by optical phase conjugation,” Opt. Lett., vol. 7, no. 11, pp. 558–560, 1982; A. Friesem, U. Levy, and Y. Silberberg, “Parallel transmission of images through single optical fibers,” Proc. IEEE, vol. 71, no. 2, pp. 208–221, 1983], digital phase conjugation [I. N. Papadopoulos, S. Farahi, C. Moser, and D. Psaltis, “Focusing and scanning light through a multimode optical fiber using digital phase conjugation,” Opt. Express, vol. 20, no. 10, pp. 10583–10590, 2012; I. N. Papadopoulos, S. Farahi, C. Moser, and D. Psaltis, “High-resolution, lensless endoscope based on digital scanning through a multimode optical fiber,” Biomed. Opt. Express, vol. 4, no. 2, pp. 260–270, 2013] or the full-wave holographic transmission matrix method. The latter technique, which is the current gold standard, measures both the amplitude and phase of the output patterns corresponding to multiple input patterns to construct a matrix of complex numbers relaying the input to the output [Y. Choi, et al., “Scanner-free and wide-field endoscopic imaging by using a single multimode optical fiber,” Phys. Rev. Lett., vol. 109, no. 20, p. 203901, 2012; A. M. Caravaca-Aguirre, E. Niv, D. B. Conkey, and R. Piestun, “Real-time resilient focusing through a bending multimode fiber,” Opt. Express, vol. 21, no. 10, pp. 12881–12887; R. Y. Gu, R. N. Mahalati, and J. M. Kahn, “Design of flexible multi-mode fiber endoscope,” Opt. Express, vol. 23, no. 21, pp. 26905–26918, 2015; D. Loterie, S. Farahi, I. Papadopoulos, A. Goy, D. Psaltis, and C. Moser, “Digital confocal microscopy through a multimode fiber,” Opt. Express, vol. 23, no. 18, pp. 23845–23858, 2015]. This matrix is then used for imaging of the inputs or projection of desired patterns. Other techniques rely on iteratively optimizing the pixel value of the input image to perform a particular task (such as focusing or displaying an image) [R. Di Leonardo and S. Bianchi, “Hologram transmission through multi-mode optical fibers,” Opt. Express, vol. 19, no. 1, pp. 247–254, 2011; T. Čižmár and K. Dholakia, “Shaping the light transmission through a multimode optical fibre: complex transformation analysis and applications in biophotonics,” Opt. Express, vol. 19, no. 20, pp. 18871–18884, 2011; T. Čižmár and K. Dholakia, “Exploiting multimode waveguides for pure fibre-based imaging,” Nat. Commun., vol. 3, no. 1, pp. 1–9, 2012; S. Bianchi and R. Di Leonardo, “A multi-mode fiber probe for holographic micromanipulation and microscopy,” Lab Chip, vol. 12, no. 3, pp. 635–639, 2012; E. R. Andresen, G. Bouwmans, S. Monneret, and H. Rigneault, “Toward endoscopes with no distal optics: video-rate scanning microscopy through a fiber bundle,” Opt. Lett., vol. 38, no. 5, pp. 609–611, 2013].
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Goryachko, Alexander Ivanovich, Sergey Nikolaevich Ivanin, and Vladimir Yurievich Buzko. "Synthesis, Microstructural and Electromagnetic Characteristics of Cobalt-Zinc Ferrite." Kondensirovannye sredy i mezhfaznye granitsy = Condensed Matter and Interphases 22, no. 4 (December 15, 2020): 446–52. http://dx.doi.org/10.17308/kcmf.2020.22/3115.
Full textAbstract:
In this study, cobalt-zinc ferrite (Co0.5Zn0.5Fe2O4) was obtained by the glycine-nitrate method followed by annealing in a high-temperature furnace at a temperature of 1300 °С. The qualitative composition and its microstructural characteristics were determined using energy-dispersive X-ray spectroscopy, X-ray diffraction analysis, and scanning electron microscopy.The analysis of the micrographs demonstrated that the cobalt-zinc ferrite micropowder obtained after thermal annealing has an average particle size of 1.7±1 μm. The analysis of XRD data showed that the annealed cobalt-zinc ferrite micropowder has a cubic crystal structure with a lattice parameter of a = 8.415 Å. Using the Scherrer and Williamson-Hall equations we calculated the average sizes of the coherent scattering regions, which were commensurate with the size of crystallites: according to the Scherrer equation D = 28.26 nm and according to the Williamson-Hall equation D = 33.59 nm and the microstress value e = 5.62×10–4 in the ferrite structure.Using a vector network analyser, the electromagnetic properties of a composite material based on synthesized cobalt-zinc ferrite were determined. The frequency dependences of the magnetic and dielectric permeability values from the measured S-parameters of the composite material (50% ferrite filler by weight and 50% paraffin) were determined using the Nicolson-Ross-Weir method and were in the range of 0.015–7 GHz. The analysis of the graphs of the dependence of the magnetic permeability on the frequency of electromagnetic radiation revealed a resonance frequency of fr ≈ 2.3 GHz. The discoveredmagnetic resonance in the UHF range allows the obtained material to be considered as being promising for use as an effective absorber of electromagnetic radiation in the range of 2–2.5 GHz.
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