Gain Deviation Research Articles

An Analog Predistorter for Doherty Power Amplifiers Based on Minimum Gain and Phase Deviation

An Analog Predistorter for Doherty Power Amplifiers Based on Minimum Gain and Phase Deviation

A Compact, Low-Profile, Broadband Quasi-Isotropic Antenna for Non-Line-of-Sight Communications

A single-feed broadband quasi-isotropic antenna was designed for non-line-of-sight (NLOS) wireless sensor networks. The proposed antenna is based on a combination of fork-shaped crossed dipoles. It shows the broadband of quasi-isotropic radiation characteristics with high radiation efficiency. The electrical size ka of the proposed antenna is 0.94 with respect to its lower operating frequency. Its profile is also extremely thin at 0.0015λ. The impedance is matched from 1.8 to 4.3 GHz, or an 81.9% fractional bandwidth, whereas the maximum gain deviation ranging from 6.2 to 9.2 dB for the quasi-isotropic radiation is achieved from 1.8 to 3.6 GHz with a 10 dB criterion, which is close to the impedance bandwidth. The performance from the computed expectations is verified, as it shows a gain deviation of 8.4–9.8 dB from 1.9 to 3.3 GHz with an 80% fractional impedance bandwidth. The proposed antenna also shows good spatial coverage of circular polarization at high frequencies. Lastly, the received power level performance of the proposed antenna is tested under the NLOS condition, which shows a higher level compared to the linearly polarized, broadband omni-directional monopole antenna.

Experimental investigation of SRS polarization pulling in depleted pump regime for various pump SOPs

This article presents an experimental investigation of polarization pulling based on stimulated Raman scattering induced by a continuous, fully polarized pump wave in an optical fibre. By means of probe wave states of polarization aggregation, degree of polarization and gain analysis, an assessment of all-optical polarization control, repolarization and amplification in a standard single mode fibre in depleted pump regime is presented. Polarization pulling is proved to be dependent on fibre length, pump power, and pump state of polarization, with respect to pump depletion effect, acting oppositely to the polarization pulling effect. Authors evaluate results aiming to obtain a configuration of stimulated Raman scattering parameters, which allows for the most effective polarization pulling, with respect to statistical stability of the process measured by standard deviation of polarization degree and polarization-dependent gain of the probe wave. The highest polarization attraction efficiency was obtained for 15 km, 0.97 W and the horizontal polarization state of the pump wave.

Combined Effect of a Bioinspired Self-Assembling Peptide and Fluoride Varnish on Remineralisation of Artificial Early Enamel Caries Lesion: An in vitro Study

Introduction: This study aimed to investigate the remineralisation effect of combined use of a bioinspired self-assembling peptide (P26) and fluoride varnish on artificial early enamel caries lesions. Methods: Bovine enamel blocks with artificial early enamel caries lesions were prepared. The blocks were randomly allocated to four experimental groups to receive the following treatments: A = P26 + fluoride varnish, B = P26, C = fluoride varnish, and D. distilled water (negative control). The treated blocks were subjected to pH cycling. Enamel blocks were collected at time points of 7 days (d7) and 21 days (d21). The mineral gain, elemental analysis and crystal characteristics of the caries lesion were assessed by micro-computed tomography, scanning electron microscopy with energy dispersive X-ray and X-ray diffraction (XRD), respectively. Results: The mean ± standard deviation of mineral gain of group A to D were 17.4 ± 4.2%, 10.7 ± 2.2%, 10.1 ± 1.2%, and 6.8 ± 0.5% at d7, respectively, and 15.2 ± 2.6%, 8.7 ± 3.1%, 9.7 ± 1.2%, and 7.8 ± 2.3% at d21, respectively. A significant higher mineral gain was observed in group A when compared to other groups at both d7 and d21 (p < 0.05). The calcium-to-phosphate ratio remained consistent across all groups, ranging between 1.2 and 1.4. XRD analysis indicated that crystal composition on the surfaces was apatite for all groups. Conclusion: In conclusion, the present study provided a first indication of better remineralisation effects of the combined use of the bioinspired self-assembling peptide P26 and fluoride varnish compared to the effects of the respective individual uses of P26 or fluoride varnish.

Effect of low doses of active chlorine on commensal populations of intestinal bacteria in rats by oral ingestion

Chlorine-containing substances are widely used as disinfectants for treating equipment surfaces and technological aids for antimicrobial treatment of a number of foodstuff in the food industry. The toxic and bactericidal effects of the active (free) chlorine they contain are well understood for the concentrations used in practice, whereas little is known about the effect of its residual (subinhibitory) amounts on the organism and on the microbiota, including the ability to induce antimicrobial resistance. The aim of the study was to investigate the effect of different doses of active chlorine at oral administration on the commensal bacteria of intestinal microbiota, body weight gain and micromorphological features of the liver in rats. Material and methods. The study was carried out on male Wistar rats, with an initial body weight of 90-100 g, which for 4 weeks received doses of active chlorine together with drinking water ad libitum, with the given concentration: subinhibitory (10 mg/L), threshold (50 mg/L) and aggravated (100 mg/L). Chloramine was used as a chlorinecontaining agent stable in aqueous solution. Body weight gain was monitored daily. After decapitation, the caecum was taken for microbiota examination as well as the liver. The phenotypic antimicrobial resistance characteristics of Enterobacteriaceae and Enterococci were studied by the disk diffusion method. Additionally, a micromorphologic study of liver slices was performed. Results. Insignificant negative deviations in the body weight gain of rats in the experimental groups receiving subinhibitory doses of active chlorine, combined with a reduced level of Enterococci and Enterobacteriaceae representatives, were revealed. No significant effect of chlorine on the levels of resistant Escherichia coli populations was found, but a tendency to exhibit antimicrobial resistance of Enterococci isolated from rats receiving low doses of active chlorine (10 and 50 mg/l) was detected. No signs of toxic effect on the liver tissue most sensitive to chlorine were detected, but some accumulations of inflammatory cells in the liver slice were revealed. Conclusion. Low doses of chlorine-containing substances at their oral consumption are not indifferent for rats' organism, causing negative phenomena in intestinal bacteria and in liver tissues at the level of tendency. It is expedient to continue studies in this direction.

Near-Field Gain Expression for Tapered Circular Aperture Antennas

Near-field electromagnetic wave, which is radiated by tapered circular aperture antennas, has found more engineering applications in many diverse fields. Through the simulation of a reflector antenna whose efficiency is up to 51.4%, it can be found that the aperture distribution cannot be regarded as uniform distribution but as tapered distribution. Thus, expressions for near fields of uniform circular apertures cannot be applied to tapered circular aperture antennas in practical engineering. To alleviate such problem, near-field calculation formulas are proposed based on the Sommerfeld integrals with steepest descents technique, which ensures the accurate and efficient analysis of the near field of the tapered circular aperture antenna. And near-field characteristics of tapered circular aperture antennas are displayed. The maximum difference of normalized near-field amplitudes between tapered and uniform distribution is 0.35V/m. Three-dimensional near-field gain of circular aperture antennas is developed from the near-field radiation pattern. The proposed expression extends the range of calculation from the axial to more directions compared with the previous expression. Also, this expression is valid in both the near field and the far field. Using full-wave simulations, results obtained from the proposed expression are compared with the simulated results. And the deviation in near-field gain is less than 0.3dB, which indicates the convenience and effectiveness of our expression. The proposed near-field gain expression can be applicable to the near-field measurement and design of millimeter or terahertz radar systems that work in the near-field region.

Uji Performa Alat Vakum Tekan Termodifikasi Untuk Impregnasi Kayu

The impregnation process is carried out to increase the resistance of wood from the attack of microorganisms such as fungi and termite attacks by placing the wood in a vacuum tube and then placing an impregnan solution into it. The limited ability of impregnation tubes is an obstacle in carrying out research and practicum activities, therefore there needs to be modifications to the impregnation tube so that the impregnation process can provide better results. Verification of the results of impregnation is done by calculating the value of weight percent gain (WPG) and relative standard deviation (%RSD) for the test of the level of appreciation. Based on the results of the experiment the highest %WPG value in the water impregnan solution was obtained from the parameter conditions of the type 3 press vacuum tool, which is with a time of 1 hour and a pressure of 5 bars and is worth (178.29±10.97). The highest %WPG value in boron solution of 5% is obtained from the condition of the type 6 press vacuum tool with a time of 3 hours and a pressure of 5 bars and is worth (5.16±0.45). The smallest %RSD value of water impregnan solution is achieved under the parameter conditions of type 4 tools at 3 hours and pressure 1 bar and is worth 3.99%. The smallest %RSD value of boron impregnan solution is 5% achieved under the parameter conditions of type 2 tools, namely within 1 hour and pressure of 3 bars and is worth 5.36%.

Dual‐band coaperture 4G/5G base station antenna array with low scattering elements

AbstractA kite‐shaped low‐band (LB) element loaded with mushroom‐shaped structure is proposed. The element has a bandpass characteristic for the electromagnetic wave within the frequency range of 3.4–3.8 GHz and can reduce the influence on the high‐band (HB) antenna in the dual‐band coaperture antenna. The LB elements operating in the 0.698–0.96 GHz frequency band are embedded in the massive multiple input, multiple output (MIMO) antenna. One prototype of the coaperture antenna is fabricated for demonstration. The measured results show that the pattern distortion of most of the antenna ports of the HB antenna is very small after adding the LB antenna. The maximum gain deviation of the traffic beam scanning within the range of ±60° is less than 0.57 dB, indicating that the LB element can effectively suppress scattering and is suitable for multiband coaperture base‐station antenna.

Investigating the benefits and perils of importing genetic material in small cattle breeding programs via simulation

Small breeding programs are limited in achieving competitive genetic gain and prone to high rates of inbreeding. Thus, they often import genetic material to increase genetic gain and to limit the loss of genetic variability. However, the benefit of import depends on the strength of genotype-by-environment interaction. Import also diminishes the relevance of domestic selection and the use of domestic breeding animals. Introduction of genomic selection has potentially exacerbated this issue, but is also opening the potential for smaller breeding programs. The aim of this paper was to determine when and to what extent small breeding programs benefit from importing genetic material by quantifying the genetic gain as well as the sources of genetic gain. We simulated 2 cattle breeding programs of the same breed that represented a large foreign and a small domestic breeding program. The programs differed in selection parameters of sire selection, and in the initial genetic mean and annual genetic gain. We evaluated a control scenario without the use of foreign sires in the domestic breeding program and 24 scenarios that varied the percentage of domestic dams mated with foreign sires, the genetic correlation between the breeding programs (0.8 or 0.9), and the time of implementing genomic selection in the domestic compared with the foreign breeding program (concurrently or with a 10-yr delay). We compared the scenarios based on the genetic gain and genic standard deviation. Finally, we partitioned breeding values and genetic trends of the scenarios to quantify the contribution of domestic selection and import to the domestic genetic gain. The simulation revealed that when both breeding programs implemented genomic selection simultaneously, the use of foreign sires increased domestic genetic gain only when genetic correlation was 0.9 (10%-18% increase). In contrast, when the domestic breeding program implemented genomic selection with a 10-yr delay, import increased genetic gain at both tested correlations, 0.8 (5%-23% increase) and 0.9 (15%-53% increase). The increase was significant when we mated at least 10% or 25% domestic females with foreign sires and increased with the increasing use of foreign sires, but with a diminishing return. The partitioning analysis revealed that the contribution of import expectedly increased with the increased use of foreign sires. However, the increase did not depend on the genetic correlation and was not proportional to the increase in domestic genetic gain. This represents a peril for small breeding programs because they could be overly relying on import with diminishing returns for the genetic gain, marginal benefit for the genetic variability, and large loss of the domestic germplasm. The benefit and peril of import depends on an interplay of genetic correlation, extent of using foreign sires, and a breeding scheme. It is therefore crucial that small breeding programs assess the possible benefits of import beyond domestic selection. The benefit of import should be weighed against the perils of decreased use of domestic sires and decreased contribution and value of domestic selection.

Beampattern Synthesis Based on Novel Receive Delay Array for Mainlobe Interference Mitigation

This paper investigates beampattern synthesis methods based on a novel Receive Delay Array (RDA) to mitigate interferences located in the mainlobe of the beampattern. In our system design, the RDA is developed by transmitting a stepped frequency linear frequency modulation waveform and delaying the received echo with a small time offset between adjacent receive antenna elements. In doing so, a range-angle-dependent beampattern is obtained in the joint transmit-receive spatial domain. A two-stage beamforming scheme, including the equivalent data-independent transmit beamforming and dimension-reduced data-dependent receive beamforming, is then proposed to mitigate mainlobe interferences. Furthermore, according to the adaptive array theory, by designing a transmit weight vector dependent of the interference steering vector, two beampattern synthesis algorithms are developed respectively based on the maximum gain and minimum deviation to adjust multiple responses of the transmit beampattern precisely. The mainlobe of the receive beampattern is also broadened with the use of the derivative constraint. By combining the devised transmit and receive weight vectors, a two-dimensional joint transmit-receive beampattern with a flat-top mainlobe and broadened nulls can be formed, where the interferences are mitigated against the direction-of-arrival (DOA) mismatch. Theoretical and practical analysis as well as parametric studies are provided to demonstrate the effectiveness of the proposed beampattern synthesis methods in mitigating mainlobe interferences.

"Breast is best"… until they say so.

In this autoethnographic article, I discuss the consequences of being exposed to two competing breastfeeding discourses during my first mothering experience-the "self-regulated dyad" and the "externally regulated dyad" discourse. The former represents the ideal scenario and the evidence-based practices recommended by the World Health Organization (i.e., breastfeeding on demand, internally regulated by the dyad). The externally regulated discourse refers to the standardized health interventions that take over when difficulties arise (e.g., weight gain deviations and latching issues). Building on Kugelmann's critique about our blind reliance on "standardized health," existing evidence, and my breastfeeding journey, I argue that unqualified and unindividualized breastfeeding interventions are highly counterproductive. To illustrate these points, I discuss the implications of the polarized interpretation of pain and the limited dyadically focused support. I then move on to analyze how ambivalent social positioning around breastfeeding impacts our experience. In particular, I found that I was highly regarded as a "good, responsible mum" up till my baby was 6 months, and how breastfeeding became increasingly challenged by others when my daughter was approaching her first birthday. Here, I discuss how performing attachment mothering identity work allowed me to navigate these challenges. Against this backdrop, I reflect upon feminist ambivalent positionings on breastfeeding and the complexity of balancing the promotion of women's hard-earned rights while supporting them to engage in whatever baby-feeding choice they feel appropriate. I conclude that unless we acknowledge the physical and social complexities of the process, and our healthcare systems seriously invest in allocating human resources and training them appropriately, breastfeeding rates may continue to suffer and women continue to interiorize it as their own failure.

Temperature-Insensitive Ka-Band Transceiver With Ultralow-Noise Self-Calibrated Low Dropout Regulator in 65-nm CMOS

This article proposes a Ka-band transceiver with an integrated local oscillator (LO) generator and multiple low dropout regulators (LDOs) to eliminate the strict requirements to the external power supply network. The proposed self-calibrated LDO eliminates the use of a bandgap reference circuit and its large flicker noise contribution in traditional power regulators to achieve ultralow-noise performance. The output of the proposed LDO is self-calibrated with temperature and process variations by autoconfiguring the feedback coefficient through a digital loop to guarantee the stable performance of its loaded high-speed circuits. The stable gain and output power of the transceiver with temperature variation are achieved by on-chip multiple self-compensation schemes, which include a self-sensing LDO for the power amplifier, a constant- <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$G_{\!m}$ </tex-math></inline-formula> bias circuit for the amplification stages, and the temperature-compensated intermediate-frequency amplifiers (TC IFAs) with proportional-to-absolute-temperature (PTAT) gain to further compensate for the gain deviation caused by the second-order effect and large-signal performance difference. Implemented in 65-nm CMOS technology, measurements indicate that the output noise of the proposed LDO is as low as 15 nV/sqrt (Hz) at 10-kHz offset and the integrated power network greatly reduces the noise influence on the LO signal compared with the traditional bandgap-referenced LDO. Furthermore, due to the adoption of the proposed temperature compensation scheme, the small-signal gains of the receiver and transmitter only fluctuate by 1.1 and 1.3 dB from <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$- 40\,\,^{\circ }\text{C}$ </tex-math></inline-formula> to <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$85~^{\circ }\text{C}$ </tex-math></inline-formula> , respectively, and the output saturated power of the transmitter varies by 0.7 dBm over the entire temperature range.

A Low-Profile Flexible Dual-Band Antenna With Quasi-Isotropic Radiation Patterns for MIMO System on UAVs

In this letter, a low-profile flexible dual-band quasi-isotropic antenna based on half-wavelength crossed dipoles is developed for unmanned aerial vehicle (UAV) applications. Specifically, to decrease the antenna profile, a coaxial structure is used to feed the antenna and no external balun is applied. Theoretical and numerical analyses of the designed antenna were conducted. To validate the design concept, an antenna prototype was fabricated and characterized. Good agreements have been observed between simulations and measurements. The measured radiation patterns show that the gain deviations across the whole spherical radiation surface are less than 7.5 dBi at 2.4 GHz and less than 8.7 dBi at 4.6 GHz. For the purpose of system demonstration, a 2 × 2 multiple-input–multiple-output (MIMO) system employing the proposed antenna was assembled. The resulting dual-band MIMO system was deployed on a UAV for ground test, validating its potential for performance improvement of UAV communications.

Experimental validation of machine-learning based spectral-spatial power evolution shaping using Raman amplifiers.

We experimentally validate a real-time machine learning framework, capable of controlling the pump power values of Raman amplifiers to shape the signal power evolution in two-dimensions (2D): frequency and fiber distance. In our setup, power values of four first-order counter-propagating pumps are optimized to achieve the desired 2D power profile. The pump power optimization framework includes a convolutional neural network (CNN) followed by differential evolution (DE) technique, applied online to the amplifier setup to automatically achieve the target 2D power profiles. The results on achievable 2D profiles show that the framework is able to guarantee very low maximum absolute error (MAE) (<0.5 dB) between the obtained and the target 2D profiles. Moreover, the framework is tested in a multi-objective design scenario where the goal is to achieve the 2D profiles with flat gain levels at the end of the span, jointly with minimum spectral excursion over the entire fiber length. In this case, the experimental results assert that for 2D profiles with the target flat gain levels, the DE obtains less than 1 dB maximum gain deviation, when the setup is not physically limited in the pump power values. The simulation results also prove that with enough pump power available, better gain deviation (less than 0.6 dB) for higher target gain levels is achievable.

Illegal Intrusion Detection for In-Vehicle CAN Bus Based on Immunology Principle

The controller area network (CAN) bus has become one of the most commonly used protocols in automotive networks. Some potential attackers inject malicious data packets into the CAN bus through external interfaces for implementing illegal operations (intrusion). Anomaly detection is a technique for network intrusion detection which can detect malicious data packs by comparing the normal data packets with incoming data packets obtained from the network traffic. The data of a normal network is in a symmetric and stable state, which will become asymmetric when compromised. Considering the in-vehicle network, the CAN bus is symmetrically similar to the immune system in terms of internal network structure and external invasion threats. In this work, we use an intrusion detection method based on the dendritic cell algorithm (DCA). However, existing studies suggest the use of optimization methods to improve the accuracy of classification algorithms, and the current optimization of the parameters of the detection method mostly relies on the manual tuning of the parameters, which is a large workload. In view of the above challenges, this paper proposes a new detection algorithm based on the particle swarm optimization algorithm (PSO) and gravitational search algorithm (GSA) to improve the dendritic cell algorithm (PSO-GSA-DCA). PSO-GSA-DCA achieves adaptive parameter tuning and improves detection accuracy by mixing optimization algorithms and using them to optimize the dendritic cell algorithm classifier. Additionally, DCA-based CAN message attribute matching rules (measured by information gain and standard deviation of CAN data) are proposed for matching the three input signals (PAMP, DS, SS) of the DCA. The experimental results show that our proposed scheme has a significant improvement in accuracy, which can reach 91.64%, and lower time loss compared with other correlation anomaly detection schemes. Our proposed method also enables adaptive tuning, which solves the problem that most models now rely on manual tuning.

Optimization of Observer Feedback Gains for Stable Sensorless IM Drives at Very Low Frequencies: A Comparative Study between GA and PSO

Instability of an adaptive flux observer (AFO) in the regenerating mode at low frequencies is a great challenge of sensorless induction motor (SIM) drives. Zero observer feedback gains (OFGs) in the regenerating mode at low frequencies are the main reasons for moving the dominant zero of the speed estimators to the unstable region. OFGs should be appropriately selected to transfer the unstable dominant zero to the stable region. In this paper, genetic algorithm (GA) and particle swarm optimization (PSO) techniques were used to design the OFGs for a stable observer. A fair comparison of the dominant zero location between the two approaches using the optimized OFGs is presented under parameter deviation. Analytical results and the design procedure of the OFGs using the two approaches are presented under deviations of stator resistance and mutual inductance to guarantee a stable dominant zero in the regenerating mode of IM. The dominant zeros obtained by PSO had a superior location to that obtained by GA for both stator resistance and mutual inductance deviations. It was observed that one of the gains had an almost constant value over a wide range of parameter deviations. However, the value of the other gain was dependent on the deviation of machine parameters. The advantage of using PSO over GA is that the relation between the gain and parameter deviation can be represented by a deterministic and mostly linear relationship. Simulation and experimental work of the SIM drive are presented and evaluated under the optimized OFGs.

Predicting the earliest deviation in weight gain in the course towards manifest overweight in offspring exposed to obesity in pregnancy: a longitudinal cohort study

BackgroundObesity in pregnancy and related early-life factors place the offspring at the highest risk of being overweight. Despite convincing evidence on these associations, there is an unmet public health need to identify “high-risk” offspring by predicting very early deviations in weight gain patterns as a subclinical stage towards overweight. However, data and methods for individual risk prediction are lacking. We aimed to identify those infants exposed to obesity in pregnancy at ages 3 months, 1 year, and 2 years who likely will follow a higher-than-normal body mass index (BMI) growth trajectory towards manifest overweight by developing an early-risk quantification system.MethodsThis study uses data from the prospective mother-child cohort study Programming of Enhanced Adiposity Risk in CHildhood–Early Screening (PEACHES) comprising 1671 mothers with pre-conception obesity and without (controls) and their offspring. Exposures were pre- and postnatal risks documented in patient-held maternal and child health records. The main outcome was a “higher-than-normal BMI growth pattern” preceding overweight, defined as BMI z-score >1 SD (i.e., World Health Organization [WHO] cut-off “at risk of overweight”) at least twice during consecutive offspring growth periods between age 6 months and 5 years. The independent cohort PErinatal Prevention of Obesity (PEPO) comprising 11,730 mother-child pairs recruited close to school entry (around age 6 years) was available for data validation. Cluster analysis and sequential prediction modelling were performed.ResultsData of 1557 PEACHES mother-child pairs and the validation cohort were analyzed comprising more than 50,000 offspring BMI measurements. More than 1-in-5 offspring exposed to obesity in pregnancy belonged to an upper BMI z-score cluster as a distinct pattern of BMI development (above the cut-off of 1 SD) from the first months of life onwards resulting in preschool overweight/obesity (age 5 years: odds ratio [OR] 16.13; 95% confidence interval [CI] 9.98–26.05). Contributing early-life factors including excessive weight gain (OR 2.08; 95% CI 1.25–3.45) and smoking (OR 1.94; 95% CI 1.27–2.95) in pregnancy were instrumental in predicting a “higher-than-normal BMI growth pattern” at age 3 months and re-evaluating the risk at ages 1 year and 2 years (area under the receiver operating characteristic [AUROC] 0.69–0.79, sensitivity 70.7–76.0%, specificity 64.7–78.1%). External validation of prediction models demonstrated adequate predictive performances.ConclusionsWe devised a novel sequential strategy of individual prediction and re-evaluation of a higher-than-normal weight gain in “high-risk” infants well before developing overweight to guide decision-making. The strategy holds promise to elaborate interventions in an early preventive manner for integration in systems of well-child care.

Can real-ear insertion gain deviations from generic fitting prescriptions predict self-reported outcomes?

Objective The aim of this study was to determine whether the differences in insertion gains from the first fit to generic prescriptions of hearing aids can predict the self-reported hearing aid (HA) outcomes for first-time and experienced HA users. Design This was a prospective observational study. Study Sample The study included 885 first-time and 330 experienced HA users with a valid real-ear measurement on both ears and answers to the abbreviated version of the Speech, Spatial, and Quality of Hearing (SSQ12) and the International Outcome Inventory for Hearing Aids (IOI-HA) questionnaires. Results K-means clustering of gain differences between individual real-ear insertion gain to three generic gain prescriptions (NAL-NL2, NAL-RP, and one-third gain rules) was performed. The gain difference at higher frequencies generally differentiated the clusters. The experienced users in the cluster with fittings closest to NAL-NL2 and NAL-RP prescription were found to exhibit a higher IOI-HA Factor 1 score (representing the overall benefit of the hearing aid use). The gain differences to generic prescription did not affect other self-reported outcomes for first-time and experienced HA users. Conclusion The experienced HA users with minimal gain deviations from generic prescriptions reported better self-perceived benefits than users with larger deviations. However, this was not apparent in first-time users.

A Small Metaline Array Antenna for Circularly Polarized Dual-Band Beam-Steering

A circularly polarized (CP), small, beam-steerable antenna is realized using bent metalines. The antenna has the following features: (i) dual-band operation at low frequency <i>f</i>_LOW (wavelength &#x03BB;_LOW) and at high frequency <i>f</i>_HIGH (wavelength &#x03BB;_HIGH), (ii) a small antenna volume of less than 0.01&#x03BB;³_LOW, (iii) a small antenna height on the order of &#x03BB;_LOW/100, (iv) a small conducting antenna footprint of 0.62&#x03BB;_LOW &#x00D7; 0.49&#x03BB;_LOW, and (v) a phased array antenna consisting of minimum array elements (two elements). Firstly, the antenna characteristics of straight and bent metalines are briefly summarized. Secondly, it is shown that an array antenna composed of two bent metalines forms a CP broadside beam at <i>f</i>_LOW using an equal-amplitude/in-phase excitation mode. This is also shown to be true at <i>f</i>_HIGH. Thirdly, each of the obtained CP broadside beams at <i>f</i>_LOW and <i>f</i>_HIGH is steered within the H-plane. The array antenna is found to have a CP beam that is steerable across a region of &#x03B8; = -40&#x00B0; to &#x03B8; = +30&#x00B0; at <i>f</i>_LOW and &#x03B8; = -40&#x00B0; to &#x03B8; = +25&#x00B0; at <i>f</i>_HIGH, with an axial ratio of less than 3 dB. During the beam steering, the gain deviation from its maximum value is found to be small: 1.7 dB at <i>f</i>_LOW and 1.4 dB at <i>f</i>_HIGH.

PENGARUH SPA BAYI TERHADAP PENINGKATAN BERAT BADAN BAYI USIA 4-6 BULAN DI WILAYAH KERJA PUSKESMAS TAPIAN DOLOK KABUPATEN SIMALUNGUN

Infan is the period as well as the time of Christ's development. It is said to be a critical period because this period is very short for the environment and it is said to be a development period because infancy is not very short and can be repeated again. The most important period of child development is infancy and toddlerhood. In infancy / toddler there is a basic growth that will determine the next child's development. Infancy is the first month of life, the baby will adapt to the environment, changes in blood circulation, and begin to work the organs of the body, and in post-neonatal the baby will experience very fast growth. One way to stimulate growth and development in children is to use the baby solus per aqua (SPA) technique. Babies who are given SPA Babies will certainly grow and develop differently from the growth and development of babies who are not given SPA Babies. This is because the Baby SPA series aims to awaken the baby's sensory and motor nerves early with certain stimuli so that babies can grow actively and be more optimal both physically and mentally. This study aims to obtain an overview of the effect of Infant SPA on weight gain aged 4 to 6 months, Measuring the weight gain of infants aged 4 to 6 months who receive and Infant SPA and those who do not receive massage and Infant SPA at the Tapian Dolok Health Center, Simalungun Regency. The hypothesis in this study is that the increase in the weight of the babies who received the Baby Spa was greater than the standard deviation of the weight gain of 36.9 with a mean difference of 48.7 grams between the two groups. The sample size obtained is 12 respondents so that the number of samples will be increased to 30 according to the minimum sample that can be analyzed statistically. So the intervention group was 30 babies and the control group was 30 babies. The results showed that there was an effect of SPA for infants on weight gain of infants at the age of 4 to 6 months. This study is expected to provide knowledge to mothers who have babies aged 4 6 months the importance of SPA for babies to the baby's weight gain.