bluuebunny/crossref_metadata_2025 huggingface dataset:
Modelling of a Flow-Induced Oscillation, Two-Cylinder, Hydrokinetic Energy Converter Based on Experimental Data
Authors: Lv Yanfang , Sun Liping , Bernitsas Michael M. , Jiang Mengjie , Sun Hai
Published: February 2021

The VIVACE Converter consists of cylindrical oscillators in tandem subjected to transverse flow-induced oscillations (FIOs) that can be improved by varying the system parameters for a given in-flow velocity: damping, stiffness, and in-flow center-to-center spacing. Compared to a single isolated cylinder, tandem cylinders can harness more hydrokinetic energy due to synergy in FIO. Experimental and numerical methods have been utilized to analyze the FIO and energy harnessing of VIVACE. A surrogate-based model of two tandem cylinders is developed to predict the power harvesting and corresponding efficiency by introducing a backpropagation neural network. It is then utilized to reduce excessive experimental or computational testing. The effects of spacing, damping, and stiffness on harvested power and efficiency of the established prediction-model are analyzed. At each selected flow velocity, optimization results of power harvesting using the prediction-model are calculated under different combinations of damping and stiffness. The main conclusions are: (1) The surrogate model, built on extensive experimental data for tandem cylinders, can predict the cylinder oscillatory response accurately. (2) Increasing the damping ratio range from 0–0.24 to 0–0.30 is beneficial for improving power efficiency, but has no significant effect on power harvesting. (3) In galloping, a spacing ratio of 1.57 has the highest optimal harnessed power and efficiency compared with other spacing values. (4) Two tandem cylinders can harness 2.01–4.67 times the optimal power of an isolated cylinder. In addition, the former can achieve 1.46–4.01 times the efficiency of the latter. (5) The surrogate model is an efficient predictive tool defining parameters of the Converter for improved energy acquisition.
Electroviscous Effects in Stationary Solid Phase Suspensions
Authors: Rubio-Hernández Francisco J.
Published: February 2021

Flowing through porous media is a matter of interest in different research fields such as medicine, engineering and science. The spontaneous appearance of ionic distribution at the solid liquid interface gives place to a reduction in the flow rate, which is generally named electroviscous effect. However, this should be differentiated in two more specific effects, the primary effect due to the distortion of ionic clouds, and the secondary effect due to the overlapping of ionic clouds. Theoretical and experimental works have not always been clearly conducted in order to separate both effects. Instead, they have been globally grouped. The purpose of this review is to revise theoretical and experimental bibliography on the electroviscous effect in stationary solid phase suspensions (porous plugs, membranes, microchannels, capillaries). The main conclusions of this brief revision are: (i) when ionic clouds are relatively small, it is possible to accept that only the primary effect is the cause for the apparent increase of the viscosity of the liquid phase when it is forced to flow relative to the stationary solid phase; (ii) although theory predicts a maximum for the variation of the overall electroviscous effect vs the relative size of the ionic cloud, it has been experimentally observed but not properly reasoned that its existence depends on the salt type; and (iii) it is necessary to justify why, if the fluid is non-Newtonian, electrokinetic parameters dominate the characteristics of the flow due to high pressure gradients, but the rheological parameters are more decisive when the flow is generated by low pressure gradients.
Dark Supernova Remnants Revealed by CO-Line Bubbles in the W43 Molecular Complex along the 4-kpc Galactic Arm
Authors: Sofue Yoshiaki
Published: February 2021

Fine structure of the density distribution in giant molecular clouds (GMCs) around W43 (G31+00+90 km s−1at ∼5.5 kpc) was analyzed using the FUGIN* CO-line survey at high-angular (20”∼0.5 pc) and velocity (1.3 km s−1) resolutions (*Four-receiver-system Unbiased Galactic Imaging survey with the Nobeyama 45-m telescope). The GMCs show highly turbulent structures, and the eddies are found to exhibit spherical bubble morphology appearing in narrow ranges of velocity channels. The bubbles are dark in radio continuum emission, unlike usual supernova remnants (SNR) or HII regions, and in infrared dust emission, unlike molecular bubbles around young stellar objects. The CO bubbles are interpreted as due to fully evolved buried SNRs in molecular clouds after rapid exhaustion of the released energy in dense molecular clouds. Then, the CO bubbles may be a direct evidence for exciting and maintaining the turbulence in GMCs by SN origin. Search for CO bubbles as “dark SNRs” (dSNR) will have implication to estimate the supernova rate more accurately, and hence the star formation activity in the Milky Way.
Pneumococcal Pneumonia and Invasive Pneumococcal Disease in Those 65 and Older: Rates of Detection, Risk Factors, Vaccine Effectiveness, Hospitalisation and Mortality
Authors: Thomas Roger E.
Published: February 2021

Pneumococcal pneumonia (PP) and invasive pneumococcal disease (IPD) are important causes of morbidity and mortality in seniors worldwide. Incidence rates and serious outcomes worsen with increasing frailty, numbers of risk factors and decreasing immune competence with increasing age. Literature reviews in Medline and Embase were performed for pneumococcal disease incidence, risk factors, vaccination rates and effectiveness in the elderly. The introduction of protein-conjugated pneumoccal vaccines (PCV) for children markedly reduced IPD and PP in seniors, but serotypes not included in vaccines and with previously low levels increased. Pneumococcal polysaccharide (PPV23) vaccination does not change nasal and pharyngeal carriage rates. Pneumococcal and influenza vaccination rates in seniors are below guideline levels, especially in older seniors and nursing home staff. Pneumococcal and influenza carriage and vaccination rates of family members, nursing home health care workers and other contacts are unknown. National vaccination programmes are effective in increasing vaccination rates. Detection of IPD and PP initially depend on clinical symptoms and new chest X ray infiltrates and then varies according to the population and laboratory tests used. To understand how seniors and especially older seniors acquire PP and IPD data are needed on pneumococcal disease and carriage rates in family members, carers and contacts. Nursing homes need reconfiguring into small units with air ventilation externally from all rooms to minimise respiratory disease transmission and dedicated staff for each unit to minimise transmision of infectious diseaases.
Sacrificial Dissolution of Zinc Electroplated and Cold Galvanized Coated Steel in Saline and Soil Environments: A Comparison
Authors: Farooq Ameeq , Masood Chaudry Umer , Saleem Ahsan , Mairaj Deen Kashif , Hamad Kotiba , Ahmad Rafiq
Published: February 2021

To protect steel structures, zinc coatings are mostly used as a sacrificial barrier. This research aims to estimate the dissolution tendency of the electroplated and zinc-rich cold galvanized (ZRCG) coatings of a controlled thickness (35 ± 1 μm) applied via brush and dip coating methods on the mild steel. To assess the corrosion behavior of these coated samples in 3.5% NaCl and 10% NaCl containing soil solutions, open circuit potential (OCP), cyclic polarization (CP), and electrochemical impedance spectroscopy (EIS) tests were performed. The more negative OCP and appreciably large corrosion rate of the electroplated and ZRCG coated samples in 3.5% NaCl solution highlighted the preferential dissolution of Zn coatings. However, in saline soil solution, the relatively positive OCP (>−850 mV vs. Cu/CuSO4) and lower corrosion rate of the electroplated and ZRCG coatings compared to the uncoated steel sample indicated their incapacity to protect the steel substrate. The CP scans of the zinc electroplated samples showed a positive hysteresis loop after 24 h of exposure in 3.5% NaCl and saline soil solutions attributing to the localized dissolution of the coating. Similarly, the appreciable decrease in the charge transfer resistance of the electroplated samples after 24 h of exposure corresponded to their accelerated dissolution. Compared to the localized dissolution of the electroplated and brush-coated samples, the dip-coated ZRCG samples exhibited uniform dissolution during the extended exposure (500 h) salt spray test.
Effect of Temperature and Flow Rate on the Cell-Free Area in the Microfluidic Channel
Authors: Rodríguez-Villarreal Angeles Ivón , Carmona-Flores Manuel , Colomer-Farrarons Jordi
Published: February 2021

Blood cell manipulation in microdevices is an interesting task for the separation of particles, by their size, density, or to remove them from the buffer, in which they are suspended, for further analysis, and more. This study highlights the cell-free area (CFA) widening based on experimental results of red blood cell (RBC) flow, suspended in a microfluidic device, while temperature and flow rate incrementally modify RBC response within the microflow. Studies of human red blood cell flow, at a concentration of 20%, suspended in its autologous plasma and phosphate-buffered saline (PBS) buffer, were carried out at a wide flow rate, varying between 10 and 230 μL/min and a temperature range of 23 °C to 50 °C. The plotted measures show an increment in a CFA near the channel wall due to cell flow inertia after a constricted channel, which becomes more significant as temperature and flow rate increase. The temperature increment widened the CFA up to three times. In comparison, flow rate increment increased the CFA up to 20 times in PBS and 11 times in plasma.
Fusion Genes and RNAs in Cancer Development
Authors: Taniue Kenzui , Akimitsu Nobuyoshi
Published: February 2021

Fusion RNAs are a hallmark of some cancers. They result either from chromosomal rearrangements or from splicing mechanisms that are non-chromosomal rearrangements. Chromosomal rearrangements that result in gene fusions are particularly prevalent in sarcomas and hematopoietic malignancies; they are also common in solid tumors. The splicing process can also give rise to more complex RNA patterns in cells. Gene fusions frequently affect tyrosine kinases, chromatin regulators, or transcription factors, and can cause constitutive activation, enhancement of downstream signaling, and tumor development, as major drivers of oncogenesis. In addition, some fusion RNAs have been shown to function as noncoding RNAs and to affect cancer progression. Fusion genes and RNAs will therefore become increasingly important as diagnostic and therapeutic targets for cancer development. Here, we discuss the function, biogenesis, detection, clinical relevance, and therapeutic implications of oncogenic fusion genes and RNAs in cancer development. Further understanding the molecular mechanisms that regulate how fusion RNAs form in cancers is critical to the development of therapeutic strategies against tumorigenesis.
Esterifications with 2-(Trimethylsilyl)ethyl 2,2,2-Trichloroacetimidate
Authors: Lin Wenhong , Meyer Shea , Dormann Shawn , Chisholm John
Published: February 2021

2-(Trimethylsilyl)ethyl 2,2,2-trichloroacetimidate is readily synthesized from 2-trimethylsilylethanol in high yield. This imidate is an effective reagent for the formation of 2-trimethylsilylethyl esters without the need for an exogenous promoter or catalyst, as the carboxylic acid substrate is acidic enough to promote ester formation without an additive. A deuterium labeling study indicated that a β-silyl carbocation intermediate is involved in the transformation.
Durability of Pavement Materials with Exposure to Various Anti-Icing Strategies
Authors: Xu Shujuan , Zhou Zhiliang , Feng Lichao , Cui Na , Xie Ning
Published: February 2021

Anti-icing is a critical topic in durability assessment for pavement infrastructures, and it varies according to local policies. To provide sufficient information to winter maintenance agencies, and help compare the merits and shortcomings of each strategy, this review summarizes the widely used anti-icing strategies, including elastic surfaces or high-friction overlays, asphalt binders mixed with anti-icing additives, pavement heating technologies, deicers, and fixed automated spray technology, from academic and practical perspectives, as well as explore the impact of deicers on the durability of concrete materials. Furthermore, the costs of each method were compared to evaluate the feasibility of them. This review not only provides a summary of previous anti-icing strategies, but also sheds light on future research trends that may help address the challenges of current anti-icing strategies, and further enhance anti-icing efficiency and reduce life cycle costs.
Topological Quantum Computing and 3-Manifolds
Authors: Asselmeyer-Maluga Torsten
Published: February 2021

In this paper, we will present some ideas to use 3D topology for quantum computing. Topological quantum computing in the usual sense works with an encoding of information as knotted quantum states of topological phases of matter, thus being locked into topology to prevent decay. Today, the basic structure is a 2D system to realize anyons with braiding operations. From the topological point of view, we have to deal with surface topology. However, usual materials are 3D objects. Possible topologies for these objects can be more complex than surfaces. From the topological point of view, Thurston’s geometrization theorem gives the main description of 3-dimensional manifolds. Here, complements of knots do play a prominent role and are in principle the main parts to understand 3-manifold topology. For that purpose, we will construct a quantum system on the complements of a knot in the 3-sphere. The whole system depends strongly on the topology of this complement, which is determined by non-contractible, closed curves. Every curve gives a contribution to the quantum states by a phase (Berry phase). Therefore, the quantum states can be manipulated by using the knot group (fundamental group of the knot complement). The universality of these operations was already showed by M. Planat et al.
Cognitive Radio MANET Waveform Design and Evaluation
Authors: Kaszuba-Chęcińska Anna , Chęciński Radosław , Gajewski Piotr , Łopatka Jerzy
Published: February 2021

The problem of waveform construction for mobile ad hoc networks with cognitive radio (MANET-CR) is discussed. This is the main limitation to widely use this very attractive technique, which does not need the deployment of expensive communication infrastructure. Two main questions correspond to MANET-CR effectiveness: spectrum sensing and spectrum sharing. The paper presents the structure of CR nodes that enables Opportunistic Spectrum Sharing. Procedures for advanced Dynamic Spectrum Management together with the concept of policy-based radio and a sensing method are presented. In the proposed system, the basic policy is to avoid interference generated by other users or jammers. The experiments were performed in a real environment, using the elaborated testbed. The results show that the use of sensing and cognitive management mechanisms enable more efficient use of the spectrum while maintaining reasonable overhead values related to the management procedures.
Performance Evaluation of IMU and DVL Integration in Marine Navigation
Authors: Fukuda Gen , Hatta Daisuke , Guo Xiaoliang , Kubo Nobuaki
Published: February 2021

Global navigation satellite system (GNSS) spoofing poses a significant threat to maritime logistics. Many maritime electronic devices rely on GNSS time, positioning, and speed for safe vessel operation. In this study, inertial measurement unit (IMU) and Doppler velocity log (DVL) devices, which are important in the event of GNSS spoofing or outage, are considered in conventional navigation. A velocity integration method using IMU and DVL in terms of dead-reckoning is investigated in this study. GNSS has been widely used for ship navigation, but IMU, DVL, or combined IMU and DVL navigation have received little attention. Military-grade sensors are very expensive and generally cannot be utilized in smaller vessels. Therefore, this study focuses on the use of consumer-grade sensors. First, the performance of a micro electromechanical system (MEMS)-based yaw rate angle with DVL was evaluated using 60 min of raw data for a 50 m-long ship located in Tokyo Bay. Second, the performance of an IMU-MEMS using three gyroscopes and three accelerometers with DVL was evaluated using the same dataset. A gyrocompass, which is equipped on the ship, is used as a heading reference. The results proved that both methods could achieve less than 1 km horizontal error in 60 min.
Anonymous Asynchronous Ratchet Tree Protocol for Group Messaging
Authors: Chen Kaiming , Chen Jiageng , Zhang Jixin
Published: February 2021

Signal is the first application that applies the double ratchet for its end-to-end encryption protocol. The core of the double ratchet protocol is then applied in WhatsApp, the most popular messaging application around the world. Asynchronous Ratchet Tree (ART) is extended from ratchet and Diffie-Hellman tree. It is the first group protocol that applies Forward Secrecy (FS) with Post-Compromised Security (PCS). However, it does not consider protecting the privacy of user identity. Therefore, it makes sense to provide anonymous features in the conditions of FS and PCS. In this paper, the concepts of Internal Group Anonymity (IGA) and External Group Anonymity (EGA) are formalized. On the basis of IGA and EGA, we develop the “Anonymous Asynchronous Ratchet Tree (AART)” to realize anonymity while preserving FS and PCS. Then, we prove that our AART meets the requirements of IGA and EGA as well as FS and PCS. Finally, the performance and related issues of AART are discussed.
Optimising Deep Learning at the Edge for Accurate Hourly Air Quality Prediction
Authors: Wardana I Nyoman Kusuma , Gardner Julian W. , Fahmy Suhaib A.
Published: February 2021

Accurate air quality monitoring requires processing of multi-dimensional, multi-location sensor data, which has previously been considered in centralised machine learning models. These are often unsuitable for resource-constrained edge devices. In this article, we address this challenge by: (1) designing a novel hybrid deep learning model for hourly PM2.5 pollutant prediction; (2) optimising the obtained model for edge devices; and (3) examining model performance running on the edge devices in terms of both accuracy and latency. The hybrid deep learning model in this work comprises a 1D Convolutional Neural Network (CNN) and a Long Short-Term Memory (LSTM) to predict hourly PM2.5 concentration. The results show that our proposed model outperforms other deep learning models, evaluated by calculating RMSE and MAE errors. The proposed model was optimised for edge devices, the Raspberry Pi 3 Model B+ (RPi3B+) and Raspberry Pi 4 Model B (RPi4B). This optimised model reduced file size to a quarter of the original, with further size reduction achieved by implementing different post-training quantisation. In total, 8272 hourly samples were continuously fed to the edge device, with the RPi4B executing the model twice as fast as the RPi3B+ in all quantisation modes. Full-integer quantisation produced the lowest execution time, with latencies of 2.19 s and 4.73 s for RPi4B and RPi3B+, respectively.
Reinforcement Learning-Based Complete Area Coverage Path Planning for a Modified hTrihex Robot
Authors: Apuroop Koppaka Ganesh Sai , Le Anh Vu , Elara Mohan Rajesh , Sheu Bing J.
Published: February 2021

One of the essential attributes of a cleaning robot is to achieve complete area coverage. Current commercial indoor cleaning robots have fixed morphology and are restricted to clean only specific areas in a house. The results of maximum area coverage are sub-optimal in this case. Tiling robots are innovative solutions for such a coverage problem. These new kinds of robots can be deployed in the cases of cleaning, painting, maintenance, and inspection, which require complete area coverage. Tiling robots’ objective is to cover the entire area by reconfiguring to different shapes as per the area requirements. In this context, it is vital to have a framework that enables the robot to maximize the area coverage while minimizing energy consumption. That means it is necessary for the robot to cover the maximum area with the least number of shape reconfigurations possible. The current paper proposes a complete area coverage planning module for the modified hTrihex, a honeycomb-shaped tiling robot, based on the deep reinforcement learning technique. This framework simultaneously generates the tiling shapes and the trajectory with minimum overall cost. In this regard, a convolutional neural network (CNN) with long short term memory (LSTM) layer was trained using the actor-critic experience replay (ACER) reinforcement learning algorithm. The simulation results obtained from the current implementation were compared against the results that were generated through traditional tiling theory models that included zigzag, spiral, and greedy search schemes. The model presented in the current paper was also compared against other methods where this problem was considered as a traveling salesman problem (TSP) solved through genetic algorithm (GA) and ant colony optimization (ACO) approaches. Our proposed scheme generates a path with a minimized cost at a lesser time.
A Do-It-Yourself Hyperspectral Imager Brought to Practice with Open-Source Python
Authors: Riihiaho Kimmo Aukusti , Eskelinen Matti Aleksanteri , Pölönen Ilkka
Published: February 2021

Commercial hyperspectral imagers (HSIs) are expensive and thus unobtainable for large audiences or research groups with low funding. In this study, we used an existing do-it-yourself push-broom HSI design for which we provide software to correct for spectral smile aberration without using an optical laboratory. The software also corrects an aberration which we call tilt. The tilt is specific for the particular imager design used, but correcting it may be beneficial for other similar devices. The tilt and spectral smile were reduced to zero in terms of used metrics. The software artifact is available as an open-source Github repository. We also present improved casing for the imager design, and, for those readers interested in building their own HSI, we provide print-ready and modifiable versions of the 3D-models required in manufacturing the imager. To our best knowledge, solving the spectral smile correction problem without an optical laboratory has not been previously reported. This study re-solved the problem with simpler and cheaper tools than those commonly utilized. We hope that this study will promote easier access to hyperspectral imaging for all audiences regardless of their financial status and availability of an optical laboratory.
A Robust Optical Sensor for Remote Multi-Species Detection Combining Frequency-Division Multiplexing and Normalized Wavelength Modulation Spectroscopy
Authors: Jin Wenling , Zhang Hui , Hu Mai , Hu Mengpeng , Wei Yubin , Liang Jingqiu , Kan Ruifeng , Wang Qiang
Published: February 2021

By combining frequency-division multiplexing and normalized wavelength modulation spectroscopy, a robust remote multi-species sensor was developed and demonstrated for practical hydrocarbon monitoring. Independently modulated laser beams are combined to simultaneously interrogate different gas samples using an open-ended centimeter-size multipass cell. Gas species of interest are demodulated with the second harmonics to enhance sensitivity, and high immunity to laser power variation is achieved by normalizing to the corresponding first harmonics. Performance of the optical sensor was experimentally evaluated using methane (CH4) and acetylene (C2H2) samples, which were separated by a 3-km fiber cable from the laser source. Sub-ppm sensitivity with 1-s time resolution was achieved for both gas species. Moreover, even with large laser intensity fluctuations ranging from 0 to 6 dB, the noise can be kept within 1.38 times as much as that of a stable intensity case. The reported spectroscopic technique would provide a promising optical sensor for remote monitoring of multi hazardous gases with high robustness.
FlexSketch: Estimation of Probability Density for Stationary and Non-Stationary Data Streams
Authors: Park Namuk , Kim Songkuk
Published: February 2021

Efficient and accurate estimation of the probability distribution of a data stream is an important problem in many sensor systems. It is especially challenging when the data stream is non-stationary, i.e., its probability distribution changes over time. Statistical models for non-stationary data streams demand agile adaptation for concept drift while tolerating temporal fluctuations. To this end, a statistical model needs to forget old data samples and to detect concept drift swiftly. In this paper, we propose FlexSketch, an online probability density estimation algorithm for data streams. Our algorithm uses an ensemble of histograms, each of which represents a different length of data history. FlexSketch updates each histogram for a new data sample and generates probability distribution by combining the ensemble of histograms while monitoring discrepancy between recent data and existing models periodically. When it detects concept drift, a new histogram is added to the ensemble and the oldest histogram is removed. This allows us to estimate the probability density function with high update speed and high accuracy using only limited memory. Experimental results demonstrate that our algorithm shows improved speed and accuracy compared to existing methods for both stationary and non-stationary data streams.
Protocol Development for Point Clouds, Triangulated Meshes and Parametric Model Acquisition and Integration in an HBIM Workflow for Change Control and Management in a UNESCO’s World Heritage Site
Authors: Plata Adela Rueda Márquez de la , Franco Pablo Alejandro Cruz , Franco Jesús Cruz , Gibello Bravo Victor
Published: February 2021

This article illustrates a data acquisition methodological process based on Structure from Motion (SfM) processing confronted with terrestrial laser scanner (TLS) and integrated into a Historic Building Information Model (HBIM) for architectural Heritage’s management. This process was developed for the documentation of Cáceres’ Almohad wall bordering areas, a UNESCO World Heritage Site. The case study’s aim was the analysis, management and control of a large urban area where the urban growth had absorbed the wall, making it physically inaccessible. The methodology applied was the combination of: clouds and meshes obtained by SfM; with images acquired from Unmanned Aerial Vehicle (UAV) and Single Lens Reflex (SLR) and terrestrial photogrammetry; and finally, with clouds obtained by TLS. The outcome was a smart-high-quality three-dimensional study model of the inaccessible urban area. The final result was two-fold. On one side, there was a methodological result, a low cost and accurate smart work procedure to obtain a three-dimensional parametric HBIM model that integrates models obtained by remote sensing. On the other side, a patrimonial result involved the discovery of a XII century wall’s section, that had supposedly been lost, that was hidden among the residential buildings. The article covers the survey campaign carried out by the research team and the techniques applied.
Extrinsic Camera Calibration with Line-Laser Projection
Authors: Van Crombrugge Izaak , Penne Rudi , Vanlanduit Steve
Published: February 2021

Knowledge of precise camera poses is vital for multi-camera setups. Camera intrinsics can be obtained for each camera separately in lab conditions. For fixed multi-camera setups, the extrinsic calibration can only be done in situ. Usually, some markers are used, like checkerboards, requiring some level of overlap between cameras. In this work, we propose a method for cases with little or no overlap. Laser lines are projected on a plane (e.g., floor or wall) using a laser line projector. The pose of the plane and cameras is then optimized using bundle adjustment to match the lines seen by the cameras. To find the extrinsic calibration, only a partial overlap between the laser lines and the field of view of the cameras is needed. Real-world experiments were conducted both with and without overlapping fields of view, resulting in rotation errors below 0.5°. We show that the accuracy is comparable to other state-of-the-art methods while offering a more practical procedure. The method can also be used in large-scale applications and can be fully automated.
Compact Quantum Magnetometer System on an Agile Underwater Glider
Authors: Page Brian R. , Lambert Reeve , Mahmoudian Nina , Newby David H. , Foley Elizabeth L. , Kornack Thomas W.
Published: February 2021

This paper presents results from the integration of a compact quantum magnetometer system and an agile underwater glider for magnetic survey. A highly maneuverable underwater glider, ROUGHIE, was customized to carry an increased payload and reduce the vehicle’s magnetic signature. A sensor suite composed of a vector and scalar magnetometer was mounted in an external boom at the rear of the vehicle. The combined system was deployed in a constrained pool environment to detect seeded magnetic targets and create a magnetic map of the test area. Presented is a systematic magnetic disturbance reduction process, test procedure for anomaly mapping, and results from constrained operation featuring underwater motion capture system for ground truth localization. Validation in the noisy and constrained pool environment creates a trajectory towards affordable littoral magnetic anomaly mapping infrastructure. Such a marine sensor technology will be capable of extended operation in challenging areas while providing high-resolution, timely magnetic data to operators for automated detection and classification of marine objects.
Real-Time Operative Coding for Endoscopic Sinonasal Procedures: Quality Improvement in Practice
Authors: Mettias Bassem , Whittaker Joshua D. , Ramakrishnan Yujay
Published: February 2021

Objective: investigate the impact of an intraoperative coding sticker (ICS) on the accuracy of coding in endoscopic sinonasal procedures. Methods: this was a two-cycle audit evaluating the accuracy (and financial impact) of intraoperative coding of sinonasal procedures at a single tertiary centre. An ICS was introduced following consultation with the coding department. The accuracy of coding was measured before (cycle 1) and after (cycle 2) the ICS was introduced to a pilot firm and compared to a control firm. The ICS was used in 35% of the pilot firm cases. Results: the accuracy of clinical coding for endoscopic sinus surgery was 60% in the first cycle. Switching to the ICS has improved the accuracy in that firm from 50% in first cycle to 70% in the second cycle (p = 0.936; Chi-squared test). The median reimbursement for endoscopic sinus surgery was equal in both cycles of £1493.00 per patient. However, inaccurate coding resulted in £109.92 excess tariff payment in first cycle and £130.96 deficiency in the second cycle. Users of ICS reported it to be easy to use for clinicians, staff and clinical coders, whilst minimizing human error. Conclusions: The integration of the ICS improves the coding in sinonasal procedures and offers low-fidelity option alternative to live coding on the computer. The accuracy was not statistically significant in the study possibly due to the low number of observations. This can allow a precise coding standard with reliable service remuneration.
OBTENCIÓN DE UNA CONFIGURACIÓN DE CIRCUITO ELECTRÓNICO BASADO EN SEMICONDUCTORES III-V PARA APLICACIONES ALREDEDOR DE LA FRECUENCIA DE 20 MHz
Authors: Prías-Barragán Jhon Jairo , Tamayo-Ocampo Ana María , Tirado-Mejía Liliana , Ariza-Calderón Hernando
Published: February 2021

En este trabajo se presenta la obtención de una configuración de circuito electrónico basado en GaSb, para una aplicación de filtro sintonizado alrededor de 20 MHz. Se implementó y automatizó la técnica de espectros-copia de amplitud y fase para el estudio de sistemas metal-semiconductor-metal, en un rango de frecuencia de medida comprendida desde 0.15 MHz hasta 60 MHz y un rango de amplitudes de voltaje comprendido desde 0 mV hasta 500 mV. Se hizo el estudio de diagramas de amplitud y fase en muestras de GaSb y GaSb/GaSb, encontrándose un estrecho pico de resonancia alrededor de 23 MHz, el cual fue modelado teóricamente mediante un circuito eléctrico equivalente basado en filtros sintonizados. A partir de este comportamiento eléctrico se diseñó e implementó una aplicación de circuito filtro, con una respuesta sintonizada alrededor de la frecuencia de 20 MHz.
ANÁLISIS DEL DESEMPEÑO DE UN SISTEMA DE COMUNICACIÓN DE DA-TOS DE CORTO ALCANCE VÍA RADIO EN 2.4 GHZ BASADO EN ESPECTRO ENSANCHADO POR SECUENCIA DIRECTA (DSSS)
Authors: Narváez-Matituy Yamith Enrique , Ordóñez-Hurtado Andrés Fernando , Quintero-Florez Víctor Manuel
Published: February 2021

En el presente artículo se hace una introducción teórica acerca de la técnica de trasmisión de Espectro En-sanchado por Secuencia Directa (DSSS, Direct Sequence Spread Spectrum) y las ventajas obtenidas al mo-dificar sus parámetros de configuración. Se presenta una descripción general del sistema de comunicación de datos vía radio de corto alcance en 2.4 GHz basado en DSSS desarrollado a partir de los dispositivos de Ra-dio Programables en un Chip (PRoC, Programmable Radio on Chip) de Cypress Semiconductor Corp. Una vez desarrollado el sistema de comunicación se diseñó un plan de pruebas para la evaluación y análisis de su desempeño a nivel físico con el fin de obtener medidas de potencia de recepción y número de errores de bits en la información recibida, a diferentes velocidades de transmisión de datos en tres escenarios específicos: exterior, interior y ante interferencia. Los resultados obtenidos permitieron realizar un análisis comparativo con el fin de determinar el comportamiento del sistema de comunicación ante diferentes condiciones de operación y en los diferentes escenarios.
IMPROVEMENT OF THE SIGNAL TO NOISE RATIO BY MEANS OF WAVELET MODULATION
Authors: Alves-Nogueira Laércio , Amazonas José Roberto
Published: February 2021

En un canal multiusuario (1) donde las señales son corrompidas por ruído blanco aditivo gaussiano (AWGN) e interferencia de acceso múltiple (MAI), un acceso múltiple por división de código (CDMA) receptor de-tecta los símbolos, o bits, y las estimaciones de los parámetros: un la transformada wavelet se aplica a los símbolos recibidos, que han sido codificados previamente en el transmisor por un código especial, el resul-tado final es una reducción del ruido (eliminación de ruido), lo que significa la mejora del rendimiento y de la tasa de error de bit del sistema .
SELECCIÓN DE WAVELETS MADRE PARA LA CARACTERIZACIÓN DE 5 TIPOS DE LATIDOS CARDIACOS EMPLEANDO LA TRANSFORMADA WAVELET DISCRETA
Authors: Orozco-Naranjo Alejandro José , Muñoz-Gutiérrez Pablo Andrés
Published: February 2021

Se documenta la evaluación de metodologías para la selección de aquellas wavelets madre que permitan caracterizar señales cardiacas de mejor manera, a partir del análisis de los coeficientes de aproximaciones y detalles, obtenidos al aplicar la transformada wavelet discreta a 5 tipos de latidos cardiacos. El indicador que permite la identificación de las wavelets madre, está basado en el análisis de la energía concentrada en las aproximaciones y detalles de los primeros cuatro niveles de descomposición. Los vectores de caracterís-ticas generados se ingresaron en Máquinas de Soporte Vectorial con Kernel Polinomial y Función de base radial, permitiendo cuantificar la capacidad de caracterización con las wavelets madre que lograron indica-dores energéticos de interés, a partir de los resultados de clasificación. La menor cantidad de errores fueron obtenidos utilizando la wavelet madre Biortogonal Inversa de orden 3.1 (rbio3.1), la cual no es mencionada comúnmente en divulgaciones científicas, con una máquina de soporte vectorial de Kernel Polinomial, cuyo error porcentual fue de 2,71%.
COMPLEJIDAD E IMPEDIMENTOS EN EL NIVEL FÍSICO PARA LA IMPLEMENTACION DE REDES SATELITALES COGNITIVAS
Authors: Astaiza-Hoyos Evelio , Bermúdez-Orozco Héctor Fabio
Published: February 2021

En este artículo se muestran algunos impedimentos que se presentan en la actualidad en el nivel físico para la implementación de redes satelitales cognitivas, adicionalmente se ilustra desde la perspectiva de la teoría de juegos como pueden ser implementadas de manera óptima algunas de las funciones cognitivas requeridas en este tipo de sistemas. Las funciones básicas de un satélite y/o estación terrena cognitiva son flexibilidad, recon-figurabilidad, autoconfigurabilidad, acceso dinámico de espectro, adaptación y aprendizaje de las condiciones del entorno para la optimización en la utilización de los recursos de radio; algunas de estas funciones pueden implementarse a través de software radio, sin embargo la gran mayoría de ellas requieren capacidades de pro-cesamiento elevadas, altos costos computacionales y tiempos de respuesta muy bajos, lo cual en muchos casos impide su implementación.
DISEÑO DIGITAL DE UNA REPETIDORA DE EMISIÓN DVB-T
Authors: Astaiza-Hoyos Evelio , Bermúdez-Orozco Héctor Fabio
Published: February 2021

In this paper, an optimal signal processing design scheme is proposed for a digital broadcast DVB – T in Digital Terrestrial Television Broadcasting (DTTB) networks. The proposed scheme consists of two stages. In the first stage (input stage), a mixer performs a Frequency Down Conversion to translate the radio signal to IF band, then, an interpolator and decimator perform the processing to change the sample rate for the AFC block. The second stage (output stage) comprises one interpolator to change the sample rate at desired rate, and one mixer to return the signal frequency to RF band. Simulations show that the proposed scheme decrea-ses the operations compared to the conventional design schemes. Additionally, implementation constraints are identified for each stage according to design requirements. Finally, some comments are presented in order to identify limitations and practical design issues in the proposed system.
Pengaruh Diversifikasi Pendapatan dan Bank Capital Buffer terhadap Kinerja dan Risiko Likuiditas pada Sektor Perbankan Syariah Indonesia
Authors: Setiawan Rahmat , Pramika Mesta
Published: February 2021

Penelitian ini bertujuan untuk mengetahui pengaruh diversifikasi pendapatan (DIVPEN) terhadap kinerja bank yang menggunakan proksi return on assets (ROA) dan return on equity (ROE) dan risiko likuiditas yang menggunakan proksi non performing financing (NPF) dengan mediasi bank capital buffer (BCB) pada sektor perbankan syariah Indonesia. Observasi dilakukan terhadap seluruh perbankan syariah yang terdaftar di Otoritas Jasa Keuangan salama periode 2009-2018. Metode analisisnya menggunakan analisis regresi linear berganda. Hasil penelitian menunjukkan bahwa DIVPEN memiliki pengaruh positif signifikan terhadap ROA dan ROE, namun berpengaruh negatif terhadap NPF. Sedangkan BCB memiliki pengaruh positif signifikan terhadap ROE dan pengaruh negatif signifikan terhadap NPF.
PEMETAAN BUSINESS MODEL CANVAS DALAM PENGEMBANGAN AGROWISATA KAMPUNG SUSU KALIPUCANG TUTUR PASURUAN
Authors: Nuzil Nur Rohmad
Published: February 2021

Agrowisata di Indonesia merupakan salah satu sektor pendorong dalam peningkatan perkonomian yang banyak diminati oleh wisatawan baik dari dalam negeri (domestik) maupun lua rnegeri (mancanegara). Padaumumnya, agrowisata berada pada kawasan dengan udara yang sejuk serta pemandangan alam yang indah, sekaligus memfasilitasi tourism yang ingin menikmati pemandangan alam disertai dengan pengetahuan tentang pengolahan produk secara alami maupun modern. Untuk mewujudkan hal tersebut perlu adanya perencanaan dalam inovasi. Penelitian ini dilakukan untuk membuat model pengembangan agrowisata yang dapat memadukan beberapa potensi unggulan yang dimiliki Desa Kalipucang dengan menggunakan Business Model Canvas (BMC). Berdasarkan hasil pemetaan pada elemen-elemen BMC, Agrowisata Kampung Susu Kalipucang telah menjalankan suatu bisnis wisata yang menawarkan nilai wisata peternakan edukatif kepada wisatawan. Secara keseluruhan, bisnis yang dijalankan telah memenuhi ke-sembilan blok elemen dalam BMC, namun diperlukan strategi guna meningkatkan kunjungan wisatawan. Hasil pemetaan BMC dianalisis dengan menggunakan SWOT untuk mendapatkan rekomendasi strategi perbaikan berikutnya. Pengelola dapat memanfaatkan kekuatannya, seperti kemampuan pengemasan acara wisata yang menarik, untuk menangkap peluang pertumbuhan pariwisata di kabupaten Pasuruan dan bersiap untuk menghadapi berbagai ancaman yang mempengaruhi keberhasilan bisnisnya.
FAKTOR VARIABEL PENYEBAB TURUNNYA GROWTH ECONOMIC KAWASAN FTZ DI KEPULAUAN RIAU
Authors: Lubis Syarif Hidayah
Published: February 2021

Of the 4 regions of the Free Trade Zone (FTZ) in Indonesia, Riau Islands has 3 regions, namely Batam, Bintan and Karimun, however, in the last 5 years the FTZ area has experienced less optimal economic growth or is experiencing a decline. Overall economic growth in the Riau Islands FTZ region During the last 6 years there has been a cumulative 6-year decline, namely Batam city at -0.476, Bintan -0.18 Karimun regency at -0.172. There are several drivers of economic growth in the FTZ region including tourism, MSMEs and inflation. The purpose of this study was to find out the variables that influence the decline in the Economic Growth / GRDP of the FTZ region in the Riau Islands Province. This study uses quantitative research by obtaining secondary data and the techniques used in collecting data are by documentation techniques, namely recording and copying of secondary data. The simultaneous results of the variables of Tourism, MSME and inflation have an effect on the Economic Growth / GRDP, simultaneously the variables of Tourism, MSMEs and inflation have an effect on Economic Growth / GRDP. Partially the tourism / tourist variables have a negative influence on economic growth / GDP. This can be seen tcount (-3.503) <ttable (1.67356) significant value (0.001) <(0.05), MSME variables have a positive effect on Economic Growth / GRDP with tcount (2.841)> t table (1.67356) and significant value (0.016) <(0.05). PMA has no effect on Economic Growth / GRDP. This can be seen with the value of tcount (1.535)  (0.05), Exports have an effect on Economic Growth / GRDP with tcount (1.803)> ttable (1.67356) and significant value (0.047) <(0.05), Inflation has an effect on Economic Growth / GRDP with tcount (0.439)  (0.05).
Implementation of Invesment Based Sales Growth (IBSG) on Asset Improvement
Authors: Puryandani Siti , Utama Oktavian Yodha
Published: February 2021

Objective: This study examines the effect of implementation of invesment based sales growth (IBSG) on asset improvement in the food and beverages companies from 2017 to 2019. In this research, IBSG consist of tangible asset, company’s growth, positioning, liquidity, sales performance, business risk, firm size, profitability, and tax. Asset Improvement reflected to capital structure which proxy is debt to total asset ratio. Research Design & Methods: The sample is taken according to purposive sampling with the criteria, finally 21 companies are taken from 31 companies. The data were examined with the assistance of SPSS21 software. Data collected from the company's financial statements and measured using a formula adopted from earlier research. Findings: tangible assets have a significant positive effect on capital structure, company’s growth has a significant negative effect on capital structure, positioning has a significant positive effect on capital structure, liquidity has a significant positive effect on capital structure, sales performance has no effect on capital structure, business risk has no effect on capital structure, firm size has a significant positive effect on capital structure, profitability has a significant positive effect on capital structure, an tax has a significant positive effect on capital structure. Limitations & Recommendations: R square value is low, then suggessted to add more variables for future research. the number of company samples is too small, then recommanded to add more period in future research. Contribution & Value Added: This result contributes to the financial literature, especially related to the companies listed in food and beverages companies group. Practically, stakeholders can use this result as additional information in making policy decisions.
Educational problems of Syrian refugee students
Authors: Celik Sevgi
Published: February 2021

This qualitative study tries to explore the problems faced by the Syrian Refugee primary school students who immigrated to the Kurdistan Region of Iraq (KRI) with their friends in the educational settings and the solutions to those problems from the perspectives of those students. The qualitative data were collected through semi-structural interviews from the 15 Syrian Students in different grades. The data were analyzed by the content analysis and descriptive analysis technique in NVivo 12. It was found out that the students were exposed the mostly ‘’ violence/ hit’’, ‘’ be disturbed’’ and ‘’ignorance’’ by their classmates. The refugee students think that those problems can be solved by their teachers, principles, and families. Some of the students said that they could solve the problems they faced by ‘’ staying away’’ or by ‘’fighting with those who behave badly.’’ Based on the interview decoding, all the Syrian refugee students expect ‘’ not to exclude them’’, ‘’respect’’ and ‘’love’’. According to these results, providing social-psychological support, language teaching programs, and teaching tolerance to local students would help to solve the immigrant students’ problems having with their friends at school.
Pemodelan Perkuatan Menggunakan Bambu Untuk Daya Dukung Pondasi Dangkal pada Tanah Gambut
Authors: Sutejo Yulindasari , Muliawan Sutanto , Dewi Ratna , Hadinata Febrian , Ariawan Budi , Rustam Reffanda Kurniawan
Published: February 2021

Some of the unfavorable characteristics of peat soil are low bearing capacity and high compressibility. The reinforcing material used in this research which functions the same as geogrid are bamboo materials (grids and woven). The bamboo material used aims to determine the carrying capacity and reduction of shallow foundations on peat soil before being reinforced and after being reinforced. Bamboo matting and rectangular patterned bamboo grids. Laboratory scale testing were used as the research methodology. The peat soil sampling location came from the area of Dusun III Banyu Urip, Banyuasin regency, South Sumatra province. The bamboo material is obtained from the Seberang Ulu area, Palembang City and sand  is obtained from the sand depot in the Musi II area, Palembang City. The results of laboratory testing show that the addition of the number of reinforcement layers and the effective layer depth distance will give a greater bearing capacity ratio (BCR) value. The bearing capacity value of the shallow foundation before being reinforced on peat soil using Terzaghi's analysis is 45.232 kpa. Then, after testing the variation in the depth of the layer d = 0b; d = 0.25b; and d = 0.5b with the number of layers 1 layer, 2 layers and 3 layers obtained a variation which gives the highest bearing capacity value of layer depth variations d = 0.25b with the number of layers of 3 layers. The bearing capacity value is 94 kpa with a BCRvalue of 2.08 (percent increase of 107.96 %).