Search results for: inverted quad-ridge horn antenna

Authors: Zhuofan Cheng, Qiongda Hu, Mohammed El-Hajjar, Basel Halak

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Multiple-input multiple-output (MIMO) systems can allow significantly higher data rates compared to single-antenna-aided systems. They are expected to be a prominent part of the 5G communication standard. However, these decoders suffer from high power consumption. This work presents a design technique in order to improve the energy efficiency of MIMO systems; this facilitates their use in the next generation of battery-operated communication devices such as mobile phones and tablets. The proposed optimization approach consists of the use of low complexity lattice reduction algorithm in combination with an adaptive VLSI implementation. The proposed design has been realized and verified in 65nm technology. The results show that the proposed design is significantly more energy-efficient than conventional K-best MIMO systems.

Keywords: energy, lattice reduction, MIMO, VLSI

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Authors: V. Bastian Aguila, C. Diego Vasco, P. Paula Galvez, R. Paula Zapata

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The main results of an experimental study of the effect of temperature and nanoparticle concentration on thermal conductivity and viscosity of a nanofluid are shown. The nanofluid was made by using octadecane as a base fluid and CuO spherical nanoparticles of 75 nm (MkNano). Since the base fluid is a phase change material (PCM) to be used in thermal storage applications, the engineered nanofluid is referred as nanoPCM. Three nanoPCM were prepared through the two-step method (2.5, 5.0 and 10.0%wv). In order to increase the stability of the nanoPCM, the surface of the CuO nanoparticles was modified with sodium oleate, and it was verified by IR analysis. The modified CuO nanoparticles were dispersed by using an ultrasonic horn (Hielscher UP50H) during one hour (amplitude of 180 μm at 50 W). The thermal conductivity was measured by using a thermal properties analyzer (KD2-Pro) in the temperature range of 30ºC to 40ºC. The viscosity was measured by using a Brookfield DV2T-LV viscosimeter to 30 RPM in the temperature range of 30ºC to 55ºC. The obtained results for the nanoPCM showed that thermal conductivity is almost constant in the analyzed temperature range, and the viscosity decreases non-linearly with temperature. Respect to the effect of the nanoparticle concentration, both thermal conductivity and viscosity increased with nanoparticle concentration. The thermal conductivity raised up to 9% respect to the base fluid, and the viscosity increases up to 60%, in both cases for the higher concentration. Finally, the viscosity measurements for different rotation speeds (30 RPM - 80 RPM) exhibited that the addition of nanoparticles modifies the rheological behavior of the base fluid, from a Newtonian to a viscoplastic (Bingham) or shear thinning (power-law) non-Newtonian behavior.

Keywords: NanoPCM, thermal conductivity, viscosity, non-Newtonian fluid

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Authors: Tejinder Singh

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This paper describes a new more efficient Hydraulic System which uses lesser work to produce more output. Conventional Hydraulic System like Hydraulic Lifts and Rams use lots of water to be pumped to produce output. TejHydroLift will do the equal amount of force with lesser input of water. The paper will show that force applied can be increased manifold without requiring to move smaller force by more distance which used to be required in Conventional Hydraulic Lifts. The paper describes one of the configurations of TejHydroLift System called “Slim Antenna TejHydroLift Configuration”. The TejHydroLift uses lesser water and hence demands lesser work to be performed to move the same load.

Keywords: alternate, hydraulic system, efficient, TejHydroLift

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Authors: Rahil Bahrami, Kaveh Ashenayi

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This paper presents a systematic classification and comparative analysis of non-isolated bi-directional DC-DC converters. The increasing demand for efficient energy conversion in diverse applications has spurred the development of various converter topologies. In this study, we categorize bi-directional converters into three distinct classes: Inverting, Non-Inverting, and Interleaved. Each category is characterized by its unique operational characteristics and benefits. Furthermore, a practical comparison is conducted by evaluating the results of simulation of each bi-directional converter. BDCs can be classified into isolated and non-isolated topologies. Non-isolated converters share a common ground between input and output, making them suitable for applications with minimal voltage change. They are easy to integrate, lightweight, and cost-effective but have limitations like limited voltage gain, switching losses, and no protection against high voltages. Isolated converters use transformers to separate input and output, offering safety benefits, high voltage gain, and noise reduction. They are larger and more costly but are essential for automotive designs where safety is crucial. The paper focuses on non-isolated systems.The paper discusses the classification of non-isolated bidirectional converters based on several criteria. Common factors used for classification include topology, voltage conversion, control strategy, power capacity, voltage range, and application. These factors serve as a foundation for categorizing converters, although the specific scheme might vary depending on contextual, application, or system-specific requirements. The paper presents a three-category classification for non-isolated bi-directional DC-DC converters: inverting, non-inverting, and interleaved. In the inverting category, converters produce an output voltage with reversed polarity compared to the input voltage, achieved through specific circuit configurations and control strategies. This is valuable in applications such as motor control and grid-tied solar systems. The non-inverting category consists of converters maintaining the same voltage polarity, useful in scenarios like battery equalization. Lastly, the interleaved category employs parallel converter stages to enhance power delivery and reduce current ripple. This classification framework enhances comprehension and analysis of non-isolated bi-directional DC-DC converters. The findings contribute to a deeper understanding of the trade-offs and merits associated with different converter types. As a result, this work aids researchers, practitioners, and engineers in selecting appropriate bi-directional converter solutions for specific energy conversion requirements. The proposed classification framework and experimental assessment collectively enhance the comprehension of non-isolated bi-directional DC-DC converters, fostering advancements in efficient power management and utilization.The simulation process involves the utilization of PSIM to model and simulate non-isolated bi-directional converter from both inverted and non-inverted category. The aim is to conduct a comprehensive comparative analysis of these converters, considering key performance indicators such as rise time, efficiency, ripple factor, and maximum error. This systematic evaluation provides valuable insights into the dynamic response, energy efficiency, output stability, and overall precision of the converters. The results of this comparison facilitate informed decision-making and potential optimizations, ensuring that the chosen converter configuration aligns effectively with the designated operational criteria and performance goals.

Keywords: bi-directional, DC-DC converter, non-isolated, energy conversion

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Authors: A. Chinig, J. Zbitou, A. Errkik, L. Elabdellaoui, A. Tajmouati, A. Tribak, M. Latrach

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This paper presents a new structure of microstrip band pass filter (BPF) based on coupled stepped impedance resonators. Each filter consists of two coupled stepped impedance resonators connected to microstrip feed lines. The coupled junction is utilized to connect the two BPFs to the antenna. This two band pass filters are designed and simulated to operate for the digital communication system (DCS) and Industrial Scientific and Medical (ISM) bands at 1.8 GHz and 2.45 GHz respectively. The proposed circuit presents good performances with an insertion loss lower than 2.3 dB and isolation between the two channels greater than 21 dB. The prototype of the optimized diplexer have been investigated numerically by using ADS Agilent and verified with CST microwave software.

Keywords: band pass filter, coupled junction, coupled stepped impedance resonators, diplexer, insertion loss, isolation

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Authors: Mohamed A. Mohamed-Ali, Jannis Simos, Khalid M. Kheiralla

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The Ingessana hills in the southern Blue Nile of Sudan are part of the southern sector of the NE-SW trending ophiolithic belt of the Arab-Nubian Shield with mid-neoproterozoic age. The rocks are mainly serpentinized and in parts highly silicified dunites especially towards the contact with the intruding Bau granite. A promising chromite mineralization zones in the area tend to be generally associated with NE-SW trending shear-zones. A detailed geophysical survey employing electrical resistivity tomography (ERT) at 34 lines were carried out over a zone of a known chromite mineralization to test feasibility of detecting and delineating the ore (if exist) and accordingly facilitate the positioning of exploratory drill holes. ERT sections were inverted with smooth constraints inversion code where the contacts between the granite and the ultramafics are showing up clearly. The continuity of mineralization along the contact is not well confirmed. However, the low-resistivity anomalies are probably recognized as potential chromite mineralization zones. These anomalies represent prime targets for further exploration by drilling, trenching or shallow pits. If the results of the drilling or excavations are positive, small open pit exploitations may produce important tonnages of chromite.

Keywords: chromite exploration, ERT, Ingessana Hills, inversion

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Authors: Thanunthon Bowornsakulwong, Charukorn Charukarn, Franck Courtes, Panit Kitsubun, Lalintip Horcharoen

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Vero cell is a continuous cell line that is widely used for the production of viral vaccines. However, due to its adherent characteristic, scaling up strategy in large-scale production remains complicated and thus limited. Consequently, suspension-like Vero cell culture processes based on microcarriers have been introduced and employed while also providing increased surface area per volume unit. However, harvesting Vero cells from microcarriers is a huge challenge due to difficulties in cells detaching, lower recovery yield, time-consuming and dissociation agent carry-over. To overcome these problems, we developed a dissociation-association platform technology for detaching and re-attaching cells during subculturing from microcarriers to microcarriers, which will be conveniently applied to seed trains strategies in large scale bioreactors. Herein, Hillex-2 was used to culture Vero cells in serum-containing media using spinner flasks as a scale-down model. The overall confluency of cells on microcarriers was observed using inverted microscope, and the sample cells were daily detached in order to obtain the kinetics data. The metabolites consumption and by-products formation were determined by Nova Biomedical BioprofileFlex.

Keywords: dissociation-reassociation, microcarrier, scale up, Vero cell

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Authors: Muhammad Afzal, Junaid Uzair Satti

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The noise emanating from the ducting of heating, ventilation, and air-conditioning (HVAC) system is often attenuated by using the dissipative silencers. Such devices work well for the high-frequency noise but are less operative in the low-frequency noise range. The present study analyzes a reactive silencer comprising expansion chamber of the elastic membranes partitioned symmetrically by a rigid plate. The Mode-Matching scheme has been developed to solve the governing boundary value problem. The orthogonal and non-orthogonal duct modes of acoustic pressures and normal velocities are matched at interfaces. It enables to recast the differential system into the infinite system of linear algebraic of equations, which is, then truncated and inverted for the solution. The truncated solution is validated through the conservation of energy and reconstruction of matching conditions. The results for scattering energy flux and transmission loss are shown against frequency and the dimensions of the chamber. It is seen that the stop-band of the silencer can be shifted to the broadband by changing the dimensions of the chamber and the properties of the elastic membranes. The modeled reactive silencer is more efficient in low frequency regime where the passive devices are least effective.

Keywords: acoustic scattering, elastic membranes mode-matching, reactive silencer

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Authors: Boudene Maamar, Xu Mai

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Optical Intersatellite Links (OISLs) are wireless communications using optical signals to interconnect satellites. It is expected to be the next generation wireless communication technology according to its inherent characteristics like: an increased bandwidth, a high data rate, a data transmission security, an immunity to interference, and an unregulated spectrum etc. Optical space links are the best choice for the classical communication schemes due to its distinctive properties; high frequency, small antenna diameter and lowest transmitted power, which are critical factors to define a space communication. This paper discusses the development of free space technology and analyses the parameters and factors to establish a reliable intersatellite links using an optical signal to exchange data between satellites.

Keywords: optical intersatellite links, optical wireless communications, free space optical communications, next generation wireless communication

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Authors: Rajesh Bera, Durbadal Mandal, Rajib Kar, Sakti P. Ghoshal

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This paper describes optimal thinning of an Elliptical Cylindrical Array (ECA) of uniformly excited isotropic antennas which can generate directive beam with minimum relative Side Lobe Level (SLL). The Particle Swarm Optimization (PSO) method, which represents a new approach for optimization problems in electromagnetic, is used in the optimization process. The PSO is used to determine the optimal set of ‘ON-OFF’ elements that provides a radiation pattern with maximum SLL reduction. Optimization is done without prefixing the value of First Null Beam Width (FNBW). The variation of SLL with element spacing of thinned array is also reported. Simulation results show that the number of array elements can be reduced by more than 50% of the total number of elements in the array with a simultaneous reduction in SLL to less than -27dB.

Keywords: thinned array, Particle Swarm Optimization, Elliptical Cylindrical Array, Side Lobe Label.

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Authors: Asmaa Sokrat, Aykut Karaman

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Public and private spaces are major components of the morphology of the city. This research aims to study the interactions between public and private domains in terms of urban space in Casablanca. The research focuses on a general vision of a socio-spatial issue. It plans to identify the public, private, and transition (semi-public, semi-private) spaces as the constituent of the urban space. Moreover, the study investigates the link between public and private spaces with the social dimensions. Additionally, the research argues that the public space is a place of social interaction; as a reflection, this interaction is the intersection between urban space and social connectedness. Besides, social interaction can be the key to distinguishing between the public and private spheres. The methodological approach of the research is based on the literature review and field study. The article is targeting a case study on the old Medina of Casablanca, from daily use of the public and private spaces, the urban tissue, and the urban space types. In conclusion, the research exhibits that a public space could influence the privacy of the residents of a local urban area; thus, this privacy is inverted on the social interaction. This social interaction is the link between the urban space and social connectedness. Hence, this equation affects the typology of the private space.

Keywords: public sphere, private sphere, social connectedness, old Medina of Casablanca

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Authors: Andrzej Mitura, Krzysztof Kecik, Michal Augustyniak

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This paper presents a numerical and experimental research of a nonlinear two degrees of freedom system. The tested system consists of a mechanical oscillator (the primary subsystem) with the attached pendulum (the secondary subsystem). The oscillator is suspended on a linear (or nonlinear) coil spring and a nonlinear magnetorheorogical damper and it is excited kinematically. Added pendulum can be used to reduce vibration of a primary subsystem or to energy harvesting. The numerical and experimental investigations showed that the pendulum can perform several types of motion, for example: chaotic motion, constant position in lower or upper (stable inverted pendulum), rotation, symmetrical or asymmetrical swinging vibrations. The main objective of this study is to determine an influence of system parameters for increasing the zone when the pendulum rotates. As a final effect a semi-active control method to change the pendulum solution on the rotation is proposed. To the implementation of this method the magnetorheorogical damper is applied. Continuous rotation of the pendulum is desirable for recovery of energy. The work is financed by Grant no. 0234/IP2/2011/71 from the Polish Ministry of Science and Higher Education in years 2012-2014.

Keywords: autoparametric vibrations, chaos and rotation control, magnetorheological damper

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Authors: Kayla Fanning

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Theocritus’ use of near-pastoral motifs in creating the lamenting narrative in “The Sorceress” idyll suggests a link between Simaetha and the quintessential shepherd that ultimately transcends the bucolic serenading structure, evident in “The Serenade”, as it pertains to depictions of women. In Theocritus’ “The Serenade”, an anonymous goatherd serenades his beloved, Amaryllis, in hopes of persuading her to reciprocate his love. This serenade soon turns into a vicious lament where all hope for reciprocation dissolves, leaving the goatherd severely melancholic and malignant. In “The Cyclops’ Serenade”, the cyclops, Polyphemus, sings of Galatea in solitude; in so doing, he negotiates between feelings of heartache and anger that eventually subside. His depiction of Galatea, in being less vindictive than the goatherd’s, manifests less toxicity. In adopting, and essentially creating, this serenading structure, Theocritus illustrates his ability to alter portrayals of women while maintaining the premise of the pastoral serenade; that is the shepherd's lament of his indifferent beloved. A thematic intertextual analysis of the idylls reveals a variety of ways in which the toxicity of the goatherd’s relation to Amaryllis is mutated or even inverted. In “The Sorceress”, a powerful witch named Simaetha spellbinds her unfaithful lover and angrily laments his betrayal in a way that is reminiscent of the goatherd's harmful behavior towards Amaryllis.

Keywords: femininity, pastoral, serenade, Theocritus

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Authors: Fang Gong

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Distance measures are an indispensable part of many instance-based learning (IBL) and machine learning (ML) algorithms. The value difference metrics (VDM) and inverted specific-class distance measure (ISCDM) are among the top-performing distance measures that address nominal attributes. VDM performs well in some domains owing to its simplicity and poorly in others that exist missing value and non-class attribute noise. ISCDM, however, typically works better than VDM on such domains. To maximize their advantages and avoid disadvantages, in this paper, a selection approach: a discriminative model for nominal attributes-based distance measures is proposed. More concretely, VDM and ISCDM are built independently on a training dataset at the training stage, and the most credible one is recorded for each training instance. At the test stage, its nearest neighbor for each test instance is primarily found by any of VDM and ISCDM and then chooses the most reliable model of its nearest neighbor to predict its class label. It is simply denoted as a discriminative distance measure (DDM). Experiments are conducted on the 34 University of California at Irvine (UCI) machine learning repository datasets, and it shows DDM retains the interpretability and simplicity of VDM and ISCDM but significantly outperforms the original VDM and ISCDM and other state-of-the-art competitors in terms of accuracy.

Keywords: distance measure, discriminative model, nominal attributes, nearest neighbor

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Authors: Recep Duzsoz, Ozlem Gormez, Umit Memis, Selma Demer, Hikmet Orhan

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Stylohyoid ligament is a connective tissue extending from apex of the styloid process to small horn of the hyoid bone. The normal length of styloid process ranges from 20 to 30 mm and measurements more than 30 mm is named stylohyoid ligament calcification (SLC). Fluorosis is a health problem that arises in individuals who intake large amounts of fluor long periods of time. The aim of this study was to investigate the effects of fluorosis on SLC. This study has been conducted on 100 patients who had SLC detected on panoramic radiograph. The study group was consisted of 50 patients with dental fluorosis and control group was consisted of 50 patients without dental fluorosis. Length and thickness of SLC were measured and the type of SLC was determined on panoramic radiographs. There was no statistically significant differences between the study and control group for SLC length, thickness and type. The thickness of left and right SLC of severe dental fluorosis group was statistically significant higher than moderate dental fluorosis group (p < 0,05). Cervicopharyngeal trauma, tonsillectomy, endocrine disease in menopause, persistent mesenchymal tissue, mechanical stress have reported as etiology of SLC in the literature and studies are still ongoing. It was reported that fluorosis as a factor on calcification of some ligaments in body (posterior longitudunal ligament, ligamentum flavum and transverse atlantal ligament) previously but relationship between fluorosis with SLC was not investigated. Our study is unique because it is the first study on SLC thickness measurements on panoramic radiographs and the relationship between fluorosis and SLC to our knowledge. According to the obtained results, it is thought that fluorosis may have an effect on SLC in thickness due to the relationship between dental fluorosis severity with SLC thickness and this study will contribute to the progress of the future studies.

Keywords: calcification, fluorosis, ligament, stylohyoid

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Authors: Mohammed Gamil Montasser, Angelo Battaglia

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Entrepreneurship is mostly related to the beginning of organization. In growing business organizations, entrepreneurship expands its conceptualization. It reveals itself through new business creation in the active organization, through renewal, change, innovation, creation and development of current organization, through breaking and changing of established rules inside or outside the organization and becomes more flexible, adaptive and competitive, also improving effectiveness of organization activity. Therefore, the topic of entrepreneurship, relates the creation of firms to personal / individual characteristics of the entrepreneurs and their social context. This paper is an empirical study, which aims to address these two gaps in the literature. For this endeavor, we use the latest available data from the Global Entrepreneurship Monitor (GEM) project. This data set is widely regarded as a unique source of information about entrepreneurial activity, as well as the aspirations and attitudes of individuals across a wide number of countries and territories worldwide. This paper tries to contribute to fill this gap, by exploring the key drivers of innovative entrepreneurship in the tourism sector. Our findings are consistent with the existing literature in terms of the individual characteristics of entrepreneurs, but quite surprisingly we find an inverted U-shape relation between human development and innovative entrepreneurship in tourism sector. It has been revealed that tourism entrepreneurs are less likely to have innovative products, compared with entrepreneurs in medium developed countries.

Keywords: GEM, human development, innovative entrepreneurship, occupational choice, tourism

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Authors: Stephanie A. Schauder, Gosia Sylwestrzak

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Overweight and obese women report avoiding preventive care due to fear of weight-related bias from medical professionals. Gynecological exams, due to their sensitive and personally invasive nature, are especially susceptible to avoidance. This research investigates the association between body mass index (BMI) and screening rates for breast and cervical cancer using claims data from 1.3 million members of a large health insurance company. Because obesity is associated with increased cancer risk, screenings for these cancers should increase as BMI increases. However, this paper finds that the distribution of cancer screening rates by BMI take an inverted U-shape with underweight and obese members having the lowest screening rates. For cervical cancer screening, those in the target population with a BMI of 23 have the highest screening rate at 68%, while Obese Class III members have a screening rate of 50%. Those in the underweight category have a screening rate of 58%. This relationship persists even after controlling for health and demographic covariates in regression analysis. Interestingly, there is no association between BMI and BRCA (BReast CAncer gene) genetic testing. This is consistent with the narrative that stigma causes avoidance because genetic testing does not involve any assessment of a person’s body. More work must be done to determine how to increase cancer screening rates in those who may feel stigmatized due to their weight.

Keywords: cancer screening, cervical cancer, breast cancer, weight stigma, avoidance of care

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Authors: Ki-Ro Kim, Seung-Jun Yu, Hyoung-Kyu Song

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Recently, the wireless communication systems are required to have high quality and provide high bit rate data services. Researchers have studied various multiple antenna scheme to meet the demand. In practical application, it is difficult to deploy multiple antennas for limited size and cost. Cooperative diversity techniques are proposed to overcome the limitations. Cooperative communications have been widely investigated to improve performance of wireless communication. Among diversity schemes, space-time block code has been widely studied for cooperative communication systems. In this paper, we propose a new cooperative scheme using pre-coding and space-time block code. The proposed cooperative scheme provides improved error performance than a conventional cooperative scheme using space-time block coding scheme.

Keywords: cooperative communication, space-time block coding, pre-coding

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Authors: Ibrahim Sani, Suleiman Mohammed., Salisu Sulaiman, Aminu Musa

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The fall army worm (FAW), Spodoptera frugiperda (J. E. Smith) (Lepidoptera, Noctuidae) has recently become one of the major threats to maize production in the world. It is native to tropical and subtropical America and began to spread to many African and a few Asian Countries. A survey for the observation of infestation and collection of fall armyworm was conducted in field planted with maize in the northern part of Katsina state. Eggs and immature stages were collected, place in a plastic container and brought to the laboratory for observation and study of developmental stages. FAW was identified based on the morphological characteristics, i.e. the “Y” inverted shape on the head capsule and the patterns of black spots on the abdominal segments (square and trapezoidal forms). Different growing stage of maize are affected by fall armyworm, but the damage is greatest during the early growing phase of corn. Heavy infestation on the leaves also cause defoliation. Four developmental stages (eggs larvae, pupae and adults) of the FAW were studied when fed with young corn under laboratory conditions. Furthermore, effective scouting or monitoring of FAW could be practice at early stage of growth of maize.

Keywords: infestation, katsina, maize, fall armyworm

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Authors: Asharaf Abdul Salam, Ibrahim Elsegaey, Rshood Khraif, Abdullah AlMutairi, Ali Aldosari

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Arab World that comprises of 22 member states of Arab League undergoes rapid transition in demographic front - fertility, mortality and migration. A distinctive geographic region spread across West Asia and North East Africa unified by Arabic language shares common values and characteristics even though diverse in economic and political conditions. Demographic lag that characterizes Arab World is unique but the present trend of declining fertility combined with the existing relatively low mortality undergoes significant changes in its population size. The current research aimed at (i) assessing the growth of population, over a period of 3 decades, (ii) exploring the components and (iii) understanding the public health impact. Based on International Data Base (IDB) of US Census Bureau, for 3 time periods – 1992, 2002 and 2012; 21 countries of Arab World have been analyzed by dividing them into four geographic sectors namely Gulf Cooperation Council (GCC), West Asia, Maghreb and Nile Valley African Horn. Population of Arab World grew widely during the past both through natural growth and migration. Immigrations pronounced especially in the resource intensive GCC nations not only from East Asian and central African countries but also from resource thrifty Arab nations. Migrations within the Arab World as well as outside of the Arab World remark an interesting demographic phenomenon that requires further research. But the transformations on public health statistics – impact of demographic change – depict a new era in the Arab World.

Keywords: demographic change, public health statistics, net migration, natural growth, geographic sectors, fertility and mortality, life expectancy

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Authors: Mai Nguyen-Phuong-Mai

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This paper incorporates insight from various models, studies and disciplines to construct a framework called the Inverted Pyramid Model. It is argued that such a framework has several advantages: (1) it reduces the shortcomings of the problem-focused approach that dominates the mainstream theories of cross-cultural management. With contributing insight from neuroscience, it suggests that training in business cross-cultural awareness should start with potential synergy emerged from differences instead of the traditional approach that focuses on the liability of foreigners and negative consequences of cultural distance. (2) The framework supports a dynamic and holistic way of analyzing cultural diversity by analyzing four major cultural units (global, national, organizational and group culture). (3) The framework emphasizes the role of individuals –an aspect of culture that is often ignored or regarded as a non-issue in the traditional approach. It is based on the notion that people don’t do business with a country, but work (in)directly with a unique person. And it is at this individual level that culture is made, personally, dynamically, and contextually. Insight from neuroscience provides significant evidence that a person can develop a multicultural mind, confirm and contradict, follow and reshape a culture, even when (s)he was previously an outsider to this culture. With this insight, the paper proposes a revision of the old adage (Think global – Act local) and change it into Think global – Plan local – Act individual.

Keywords: static–dynamic paradigm, cultural diversity, multicultural mind, neuroscience

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Authors: Mohamed Ramdani, Hassen Abdellaoui, Abdenour Boudrassen

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Mobile platform’s attitude estimation approaches mainly based on combined positioning techniques and developed algorithms; which aim to reach a fast and accurate solution. In this work, we describe the design and the implementation of an attitude determination (AD) process, using only measurements from GPS sensors. The major issue is based on smoothed GPS code data using Hatch filter and raw carrier-phase measurements integrated into attitude algorithm based on vectors measurement using least squares (LSQ) estimation method. GPS dataset from a static experiment is used to investigate the effectiveness of the presented approach and consequently to check the accuracy of the attitude estimation algorithm. Attitude results from GPS multi-antenna over short baselines are introduced and analyzed. The 3D accuracy of estimated attitude parameters using smoothed measurements is over 0.27°.

Keywords: attitude determination, GPS code data smoothing, hatch filter, carrier-phase measurements, least-squares attitude estimation

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Authors: Nurbanu Guzey, S. Jagannathan

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Locating radio controlled (RC) devices using their unintended emissions has a great interest considering security concerns. Weak nature of these emissions requires near field localization approach since it is hard to detect these signals in far field region of array. Instead of only angle estimation, near field localization also requires range estimation of the source which makes this method more complicated than far field models. Challenges of locating such devices in a near field region and real time environment are analyzed in this paper. An ESPRIT like near field localization scheme is utilized for both angle and range estimation. 1-D search with symmetric subarrays is provided. Two 7 element uniform linear antenna arrays (ULA) are employed for locating RC source. Experiment results of location estimation for one unintended emitting walkie-talkie for different positions are given.

Keywords: localization, angle of arrival (AoA), range estimation, array signal processing, ESPRIT, Uniform Linear Array (ULA)

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Authors: Chien-Chun Hung, Chun-Fong Wu

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It is important for a commander to have real-time information to aware situations and to make decision in the battlefield. Results of modern technique developments have brought in this kind of information for military purposes. Unmanned aerial vehicle (UAV) is one of the means to gather intelligence owing to its widespread applications. It is still not clear whether or not the mini UAV with short-range wireless transmission system is used as a reconnaissance system in Taiwanese. In this paper, previous experience on the research of the sort of aerial vehicles has been applied with a data-relay system using the ZigBee modulus. The mini UAV developed is expected to be able to collect certain data in some appropriate theaters. The omni-directional antenna with high gain is also integrated into mini UAV to fit the size-reducing trend of airborne sensors. Two advantages are so far obvious. First, mini UAV can fly higher than usual to avoid being attacked from ground fires. Second, the data will be almost gathered during all maneuvering attitudes.

Keywords: mini UAV, reconnaissance, wireless transmission, ZigBee modulus

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Authors: Courtney Laurey Davids

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Mary Shelley’s two 19th century novels, the seminal Frankenstein (1818) and the less popular The Last Man (1826) draw on Gothic elements that invite a futuristic questioning and critique of man’s fallibility and propensity to be the author of his own demise be it by transgressing natural law through a scientific endeavour or ‘birthing’ a plague. Recent scholarship about ‘prophetic’ voices in fiction considers The Last Man an influential but overlooked novel deserving of renewed scholarly interest. Through close textual analysis and comparative reading, this paper seeks to explore the continuities (and discontinuities) in thematic concern of creator and creation in Frankenstein and The Last Man, emblematic in the oppositional characters of Victor Frankenstein and the Creature and Adrian, Earl of Windsor and Lionel Verney, his ‘creation’ in The Last Man. It argues that the creator/creation dynamic between Frankenstein and the Creature is to an extent revisited and inverted in Adrian and Verney but presented as no less problematic in The Last Man’s critique of man’s inevitable folly despite nurturing and acceptance of the marginalised figure. Drawing on Romanticism ideals of nature, its foregrounding of a scourging pandemic as punishment for man’s self-dislocation and with nature is a mirroring of Frankenstein and the Creature’s own plague-like deterioration and alienation from self and nature. In a sense, both Verney and the Creature as solitary figures at the novels' denouement are ‘last men’, having learned much about man and society and upon whom the moral injunction rests. In Verney, however, the moral warning coupled with the hope that man can yet be saved offers a different reading perhaps from Frankenstein regarding the creator/creation dichotomy.

Keywords: creator/creation, Frankenstein, Mary Shelley, The Gothic, The Last Man

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Authors: Jaechoul Shin, Juhwan Hwang

Abstract:

In case of applying the BIM method to the civil engineering in the area of free formed structure, we can expect comparatively high rate of construction productivity as it is in the building engineering area. In this research, we developed quantity calculation error applying it to earthwork and bridge construction (e.g. PSC-I type segmental girder bridge amd integrated bridge of steel I-girders and inverted-Tee bent cap), NATM (New Austrian Tunneling Method) tunnel construction, retaining wall construction, culvert construction and implemented BIM based 3D modeling quantity survey. we confirmed high reliability of the BIM-based method in structure work in which errors occurred in range between -6% ~ +5%. Especially, understanding of the problem and improvement of the existing 2D-CAD based of quantity calculation through rock type quantity calculation error in range of -14% ~ +13% of earthwork quantity calculation. It is benefit and applicability of BIM method in civil engineering. In addition, routine method for quantity of earthwork has the same error tolerance negligible for that of structure work. But, rock type's quantity calculated as the error appears significantly to the reliability of 2D-based volume calculation shows that the problem could be. Through the estimating quantity of earthwork based 3D-BIM, proposed method has better reliability than routine method. BIM, as well as the design, construction, maintenance levels of information when you consider the benefits of integration, the introduction of BIM design in civil engineering and the possibility of applying for the effectiveness was confirmed.

Keywords: BIM, 3D modeling, 3D-BIM, quantity of earthwork

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Authors: Thoetchai Peeraphatdit, Peter A. Brady, Suraj Kapa, Samuel J. Asirvatham, Niyada Naksuk

Abstract:

Background: Serum electrolyte abnormalities are a common cause of an acquired prolonged QT syndrome, especially, in the coronary care unit (CCU) setting. Optimal electrolyte ranges among the CCU patients have not been sufficiently investigated. Methods: We identified 8,498 consecutive CCU patients who were admitted to the CCU at Mayo Clinic, Rochester, the USA, from 2004 through 2013. Association between first serum electrolytes and baseline corrected QT intervals (QTc), as well as in-hospital mortality, was tested using multivariate linear regression and logistic regression, respectively. Serum potassium 4.0- < 4.5 mEq/L, ionized calcium (iCa) 4.6-4.8 mg/dL, and magnesium 2.0- < 2.2 mg/dL were used as the reference levels. Results: There was a modest level-dependent relationship between hypokalemia ( < 4.0 mEq/L), hypocalcemia ( < 4.4 mg/dL), and a prolonged QTc interval; serum magnesium did not affect the QTc interval. Association between the serum electrolytes and in-hospital mortality included a U-shaped relationship for serum potassium (adjusted odds ratio (OR) 1.53 and OR 1.91for serum potassium 4.5- < 5.0 and ≥ 5.0 mEq/L, respectively) and an inverted J-shaped relationship for iCa (adjusted OR 2.79 and OR 2.03 for calcium < 4.4 and 4.4- < 4.6 mg/dL, respectively). For serum magnesium, the mortality was greater only among patients with levels ≥ 2.4 mg/dL (adjusted OR 1.40), compared to the reference level. Findings were similar in sensitivity analyses examining the association between mean serum electrolytes and mean QTc intervals, as well as in-hospital mortality. Conclusions: Serum potassium 4.0- < 4.5 mEq/L, iCa ≥ 4.6 mg/dL, and magnesium < 2.4 mg/dL had a neutral effect on QTc intervals and were associated with the lowest in-hospital mortality among the CCU patients.

Keywords: calcium, electrocardiography, long-QT syndrome, magnesium, mortality, potassium

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Authors: Alexandra Amling, Emina Sadic

Abstract:

The migration routes linking the Horn of Africa to Europe shift in response to political and humanitarian developments across the region. Abrupt changes to those routes can have profound effects on the relative ease of movement and the well-being of migrants. Somali migrants have traditionally been able to rely on a sophisticated, well-established, and reliable network of smugglers to facilitate their journey through the Sahel to Libya, but changes to the routes have undermined those networks. Recently, these shifts have made the journey from Somalia to Europe much more perilous. As the Libyan coast guard intensifies its efforts to stymie boats leaving its coast for Italian shores, arrivals in Spain are trending upwards. This paper thus, will examine how the instability in transit countries that are most commonly used by Somali migrants has had an impact on the reliability of their massive network of smuggling, and how resurgence in the Western route toward Spain provides a potentially new opportunity to reach Europe—a route that has rarely been used by the Somali migrant population in the past. First, the paper will discuss what scholars have called the pastoralist, nomadic tradition of Somalis which reportedly has allowed them to endure the long journeys from Somalia to their chosen destinations. Facilitated by relatives or clan affiliation, Somali migrants have historically been able to rely on a smuggling network that – at least tangentially – provided more security nets during their travels. Given the violence and chaos that unfolded both in Libya and Yemen in 2011 and 2015, respectively, the paper will, secondly, examine which actors in smuggling hubs increase the vulnerabilities of Somalis, pushing them to consider other routes. As a result, this paper will consider to what extent Somalis could follow the stream of other migrants to Algeria and Morocco to enter Europe via Spain. By examining one particular group of migrants and the nature and limitations of the networks associated with their movements, the paper will demonstrate the resilience and adaptability of both the migrants and the networks regardless of the ever-changing nature of migration routes and actors.

Keywords: Europe, migration, smuggling networks, Somalia

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Authors: Imen Soltani, Takoua Soltani, Taoufik Aguili

Abstract:

Metamaterials crossover classic physical boundaries and gives rise to new phenomena and applications in the domain of beam steering and shaping. Where electromagnetic near and far field manipulations were achieved in an accurate manner. In this sense, 3D imaging is one of the beneficiaries and in particular Denis Gabor’s invention: holography. But, the major difficulty here is the lack of a suitable recording medium. So some enhancements were essential, where the 2D version of bulk metamaterials have been introduced the so-called metasurface. This new class of interfaces simplifies the problem of recording medium with the capability of tuning the phase, amplitude, and polarization at a given frequency. In order to achieve an intelligible wavefront control, the electromagnetic properties of the metasurface should be optimized by means of solving Maxwell’s equations. In this context, integral methods are emerging as an important method to study electromagnetic from microwave to optical frequencies. The method of moment presents an accurate solution to reduce the problem of dimensions by writing its boundary conditions in the form of integral equations. But solving this kind of equations tends to be more complicated and time-consuming as the structural complexity increases. Here, the use of equivalent circuit’s method exhibits the most scalable experience to develop an integral method formulation. In fact, for allaying the resolution of Maxwell’s equations, the method of Generalised Equivalent Circuit was proposed to convey the resolution from the domain of integral equations to the domain of equivalent circuits. In point of fact, this technique consists in creating an electric image of the studied structure using discontinuity plan paradigm and taken into account its environment. So that, the electromagnetic state of the discontinuity plan is described by generalised test functions which are modelled by virtual sources not storing energy. The environmental effects are included by the use of an impedance or admittance operator. Here, we propose a tunable metasurface composed of graphene-based elements which combine the advantages of reflectarrays concept and graphene as a pillar constituent element at Terahertz frequencies. The metasurface’s building block consists of a thin gold film, a dielectric spacer SiO₂ and graphene patch antenna. Our electromagnetic analysis is based on the method of moment combined with generalised equivalent circuit (MoM-GEC). We begin by restricting our attention to study the effects of varying graphene’s chemical potential on the unit cell input impedance. So, it was found that the variation of complex conductivity of graphene allows controlling the phase and amplitude of the reflection coefficient at each element of the array. From the results obtained here, we were able to determine that the phase modulation is realized by adjusting graphene’s complex conductivity. This modulation is a viable solution compared to tunning the phase by varying the antenna length because it offers a full 2π reflection phase control.

Keywords: graphene, method of moment combined with generalised equivalent circuit, reconfigurable metasurface, reflectarray, terahertz domain

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Authors: J. Chamorro-Servent, S. Tassani, M. A. Gonzalez-Ballester, L. J. Roca, J. Romeu, O. Camara

Abstract:

Electromagnetic and microwave imaging (MWI) have been used in medical imaging in the last years, being the most common applications of breast cancer and stroke detection or monitoring. In those applications, the subject or zone to observe is surrounded by a number of antennas, and the Nyquist criterium can be satisfied. Additionally, the space between the antennas (transmitting and receiving the electromagnetic fields) and the zone to study can be prepared in a homogeneous scenario. However, this may differ in other cases as could be intracardiac catheters, stomach monitoring devices, pelvic organ systems, liver ablation monitoring devices, or uterine fibroids’ ablation systems. In this work, we analyzed different MWI algorithms to find the most suitable method for dealing with an intrabody scenario. Due to the space limitations usually confronted on those applications, the device would have a cylindrical configuration of a maximum of eight transmitters and eight receiver antennas. This together with the positioning of the supposed device inside a body tract impose additional constraints in order to choose a reconstruction method; for instance, it inhabitants the use of well-known algorithms such as filtered backpropagation for diffraction tomography (due to the unusual configuration with probes enclosed by the imaging region). Finally, the difficulty of simulating a realistic non-homogeneous background inside the body (due to the incomplete knowledge of the dielectric properties of other tissues between the antennas’ position and the zone to observe), also prevents the use of Born and Rytov algorithms due to their limitations with a heterogeneous background. Instead, we decided to use a time-reversed algorithm (mostly used in geophysics) due to its characteristics of ignoring heterogeneities in the background medium, and of focusing its generated field onto the scatters. Therefore, a 2D time-reversed finite difference time domain was developed based on the time-reversed approach for microwave breast cancer detection. Simultaneously an in-silico testbed was also developed to compare ground-truth dielectric properties with corresponding microwave imaging reconstruction. Forward and inverse problems were computed varying: the frequency used related to a small zone to observe (7, 7.5 and 8 GHz); a small polyp diameter (5, 7 and 10 mm); two polyp positions with respect to the closest antenna (aligned or disaligned); and the (transmitters-to-receivers) antenna combination used for the reconstruction (1-1, 8-1, 8-8 or 8-3). Results indicate that when using the existent time-reversed method for breast cancer here for the different combinations of transmitters and receivers, we found false positives due to the high degrees of freedom and unusual configuration (and the possible violation of Nyquist criterium). Those false positives founded in 8-1 and 8-8 combinations, highly reduced with the 1-1 and 8-3 combination, being the 8-3 configuration de most suitable (three neighboring receivers at each time). The 8-3 configuration creates a region-of-interest reduced problem, decreasing the ill-posedness of the inverse problem. To conclude, the proposed algorithm solves the main limitations of the described intrabody application, successfully detecting the angular position of targets inside the body tract.

Keywords: FDTD, time-reversed, medical imaging, microwave imaging

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