Double Input Research Articles

Response of methane emissions to litter input manipulation in a temperate freshwater marsh, Northeast China

The photograph of the field experiment of different litter input manipulations in situ and the treatment effects on CH 4 fluxes during observations in 2015 and 2016. Abbreviations: NL, no aboveground litter; DL, double litter; CK, control; AR, standing litter removal. • We conducted a two seasons litter input manipulation experiment in a freshwater marsh. • Litter input manipulations obviously affected CH 4 emission and surface DOC contents. • Litter removal induced higher soil temperature, DOC content and CH 4 emission. • The abundance of methanogens in surface soil relied on the ways of litter manipulation. Plant litter plays an important role in regulating CH 4 emission in wetland ecosystems. Our knowledge of the impacts of plant litter on CH 4 budget is important for understanding the response and feedbacks of wetland ecosystems to climate warming. Nevertheless, the effects of plant litter on CH 4 emission and temperature sensitivity (Q 10 ) are not clear under the background of global change. In this study, a field litter inputs manipulation experiment with four treatments including no aboveground litter (NL), standing litter removal (AR), doubled litter input (DL) and controls (CK) was conducted to study the effects of litter manipulations on CH 4 emission in a seasonal inundated freshwater marsh over two growing seasons of 2015 and 2016 in the Sanjiang Plain, Northeast China. Results showed that CH 4 emission was significantly associated with altered litter input over the observation period. Compared with CK, the cumulative CH 4 emission increased by 105.83%, 42.20% and 42.50% for NL, AR and DL treatments, respectively, in 2015, and the values were 199.04%, 115.55% and 17.55%, in 2016. Variances of CH 4 emission were more sensitive to litter removal effects. Altered litter input also significantly affected the dissolved organic carbon (DOC) concentration ([DOC]) in surface pore water. DL and CK treatments with lower soil temperature had lower [DOC] than litter removal treatments of NL and AR. The abundance of methanogens among the four treatments exhibited synchronous change with DOC over the observation period. The Q 10 values of CH 4 emission didn’t show consistent changing patterns with those of DOC among different litter input treatments, which was probably due to the different temperature sensitivity of dominant methanogen types. Due to its great effects on soil microclimate, substrate availability and the concomitant variation in temperature sensitivity, our results highlighted that plant litter effects should be incorporated into the current process-based CH 4 biogeochemical models to predict future CH 4 fluxes from natural wetlands under the background of global change.

Litter Management as a Key Factor Relieves Soil Respiration Decay in an Urban-Adjacent Camphor Forest under a Short-Term Nitrogen Increment

Increases in bioavailable nitrogen (N) level can impact the soil carbon (C) sequestration in many forest ecosystems through its influences on litter decomposition and soil respiration (Rs). This study aims to detect whether the litter management can affect the influence of N addition on Rs. We conducted a one-year field experiment in a camphor forest of central-south China to investigate the responses of available N status and soil Rs to N addition and litter manipulation. Four N addition plots (NH4NO3; 0, 5, 15, 30 g N m−2 year−1 as N0, N1, N2, N3, respectively) were established with three nested litter treatments: natural litter input (CK), double litter input (LA), and non-litter input (LR). We found a short-lived enhancement effect of N addition on soil (NO3-N) and net nitrification (RN), but not on (NH4-N), net ammonification (RA), or mineralization (RM). N addition also decreased Rs in CK spots, but not in LA or LR spots, in which the negative effects of N additions on Rs were alleviated by either litter addition or reduction. A priming effect was also observed in LA treatments. A structural equation modeling analysis showed that litter treatments had direct positive effects on soil available N contents and Rs, which suggested that litter decomposition may benefit from litter management when N is not a limiting factor in subtropical forests.

Investigation of the double input power converter with N stages of voltage multiplier using PSO‐based MPPT technique for the thermoelectric energy harvesting system

SummaryThis research work presents a thermoelectric energy harvesting system comprises of a double input DC‐DC converter with maximum power point tracking (MPPT) technique under varying temperature conditions (VTCs). The converter has two inputs with N stages of diode‐capacitor to boost the output voltage. It has the advantages of higher voltage gain and flexibility of power‐sharing by both the independent sources. The perturb and observe (P&O)‐based MPPT algorithm is an efficient and simple method to track the maximum power. However, the power‐current (P‐I) characteristics of the thermoelectric modules exhibit multiple peaks at VTCs; it fails to identify the global peak point (GPP) and gets track the local peak point. To overcome the drawback of the P&O technique, a particle swarm optimization (PSO)‐based MPPT technique is implemented to track the GPP. A comparison is performed between the P&O and PSO technique in terms of MPPT tracking efficiency and oscillation around the maximum power point. From the acquired results of simulation and experiment, it is recommended that the PSO‐based MPPT technique has furnished better overall performance.

Double SHA-256 Hardware Architecture With Compact Message Expander for Bitcoin Mining

In the Bitcoin network, computing double SHA-256 values consumes most of the network energy. Therefore, reducing the power consumption and increasing the processing rate for the double SHA-256 algorithm is currently an important research trend. In this paper, we propose a high-data-rate low-power hardware architecture named the compact message expander (CME) double SHA-256. The CME double SHA-256 architecture combines resource sharing and fully unrolled datapath technologies to achieve both a high data rate and low power consumption. Notably, the CME algorithm utilizes the double SHA-256 input data characteristics to further reduce the hardware cost and power consumption. A review of the literature shows that the CME algorithm eliminates at least 9.68% of the 32-bit XOR gates, 16.49% of the 32-bit adders, and 16.79% of the registers required to calculate double SHA-256. We synthesized and laid out the CME double SHA-256 using CMOS $0.18~\mu m$ technology. The hardware cost of the synthesized circuit is approximately 13.88% less than that of the conventional approach. The chip layout size is $5.9 mm \times 5.9 mm$ , and the correctness of the circuit was verified on a real hardware platform (ZCU 102). The throughput of the proposed architecture is 61.44 Gbps on an ASIC with Rohm 180nm CMOS standard cell library and 340 Gbps on a FinFET FPGA 16nm Zynq UltraScale+ MPSoC ZCU102.

A PERCEPTRON-BASED FEATURE SELECTION APPROACH FOR DECISION TREE CLASSIFICATION

The use of OBIA for high spatial resolution image classification can be divided in two main steps, the first being segmentation and the second regarding the labeling of the objects in accordance with a particular set of features and a classifier. Decision trees are often used to represent human knowledge in the latter. The issue falls in how to select a smaller amount of features from a feature space with spatial, spectral and textural variables to describe the classes of interest, which engenders the matter of choosing the best or more convenient feature selection (FS) method. In this work, an approach for FS within a decision tree was introduced using a single perceptron and the Backpropagation algorithm. Three alternatives were compared: single, double and multiple inputs, using a sequential backward search (SBS). Test regions were used to evaluate the efficiency of the proposed methods. Results showed that it is possible to use a single perceptron in each node, with an overall accuracy (OA) between 77.6% and 77.9%. Only SBS reached an OA larger than 88%. Thus, the quality of the proposed solution depends on the number of input features.

Tooth detection and classification on panoramic radiographs for automatic dental chart filing: improved classification by multi-sized input data.

Dental state plays an important role in forensic radiology in case of large scale disasters. However, dental information stored in dental clinics are not standardized or electronically filed in general. The purpose of this study is to develop a computerized system to detect and classify teeth in dental panoramic radiographs for automatic structured filing of the dental charts. It can also be used as a preprocessing step for computerized image analysis of dental diseases. One hundred dental panoramic radiographs were employed for training and testing an object detection network using fourfold cross-validation method. The detected bounding boxes were then classified into four tooth types, including incisors, canines, premolars, and molars, and three tooth conditions, including nonmetal restored, partially restored, and completely restored, using classification network. Based on the visualization result, multisized image data were used for the double input layers of a convolutional neural network. The result was evaluated by the detection sensitivity, the number of false-positive detection, and classification accuracies. The tooth detection sensitivity was 96.4% with 0.5 false positives per case. The classification accuracies for tooth types and tooth conditions were 93.2% and 98.0%. Using the double input layer network, 6 point increase in classification accuracy was achieved for the tooth types. The proposed method can be useful in automatic filing of dental charts for forensic identification and preprocessing of dental disease prescreening purposes.

0.5 V Fully Differential Universal Filter Based on Multiple Input OTAs

The design of a low-power, low-voltage, fully-differential universal biquad filter is presented in this work, which is constructed from four multiple-input gate-driven operational transconductance amplifiers (MI-OTAs) along with one passive resistor and two passive capacitors. The scheme of presented biquad filter has three high-input impedance voltage nodes and single output voltage node. Five unity gain filtering functions, all-pass (AP), low-pass (LP), band-pass (BP), high-pass (HP) and band-stop (BS) responses, are obtained. The selection of output filtering responses is obtained without the need of component matching condition, inverting or double input voltage. With this feature, it can be easily controlled with digital programming. The quality factor (Q) and angular frequency (ω <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">0</sub> ) are electronically and independently tuned. Moreover, the adjustment of ω <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">0</sub> and Q can be done without affecting the voltage gain. A workability of the design is confirmed via Cadence software and the Spectre simulator based on the 180 nm TSMC CMOS technology parameters. The proposed fully differential filter operates with 0.5 V supply voltage. The results verify that the proposed filter dissipates the total power of 53.3 nW. Additionally, the dynamic range (DR) of band-pass filtering function is 63 dB for 2% third intermodulation distortion (IMD). Also, the simulated RMS value of the band-pass filtering noise is 45μV.

A Refined Loss Evaluation of a Three-Switch Double Input DC-DC Converter for Hybrid Vehicle Applications

In this paper, an accurate efficiency evaluation of an innovative three-switch double input DC–DC converter for hybrid vehicle applications was carried out. The converter was used to interface two storages, (e.g., supercapacitor and battery) to the DC link. A refined model was created in MATLAB/Simulink Plecs environment and it was used to compare the traditional four-switch converter (i.e., two DC–DC converters in parallel connection) with the innovative three-switch converter. Loss and efficiency contour maps were obtained for both converters and a comparison between them was performed. A prototype of the three-switch converter was realized and used to validate the simulation thermal model by comparing both efficiency and current waveforms obtained with simulations and experimental tests.

Multi-class discrimination of lymphadenopathy by using dual-modal ultrasound radiomics with elastography and B-mode ultrasound

The purpose of our study is to evaluate the diagnostic performance of radiomics in multi-class discrimination of lymphadenopathy based on elastography and B-mode dual-modal ultrasound images. We retrospectively analyzed a total of 251 lymph nodes (89 benign lymph nodes, 70 lymphoma and 92 metastatic lymph nodes) from 248 patients, which were examined by both elastography and B-mode sonography. Firstly, radiomic features were extracted from multimodal ultrasound images, including shape features, intensity statistics features and gray-level co-occurrence matrix texture features. Secondly, three feature selection methods based on information theory were used on the radiomic features to select different subsets of radiomic features, consisting of conditional infomax feature extraction, conditional mutual information maximization, and double input symmetric relevance. Thirdly, the support vector machine classifier was performed for diagnosis of lymphadenopathy on each radiomic subsets. Finally, we fused the results from different modalities and different radiomic feature subsets with Adaboost to improve the performance of lymph node classification. The results showed that the accuracy and overall F1 score with five-fold cross-validation were 76.09%±1.41% and 75.88%±4.32%, respectively. Moreover, when considering on benign lymph nodes, lymphoma or metastatic lymph nodes respectively, the area under the receiver operating characteristic curve of multi-class classification were 0.77, 0.93 and 0.84, respectively. This study indicates that radiomic features derived from multimodal ultrasound images are benefit for diagnosis of lymphadenopathy. It is expected to be useful in clinical differentiation of lymph node diseases.

Tropical forest soil carbon stocks do not increase despite 15 years of doubled litter inputs

Soil organic carbon (SOC) dynamics represent a persisting uncertainty in our understanding of the global carbon cycle. SOC storage is strongly linked to plant inputs via the formation of soil organic matter, but soil geochemistry also plays a critical role. In tropical soils with rapid SOC turnover, the association of organic matter with soil minerals is particularly important for stabilising SOC but projected increases in tropical forest productivity could trigger feedbacks that stimulate the release of stored SOC. Here, we demonstrate limited additional SOC storage after 13–15 years of experimentally doubled aboveground litter inputs in a lowland tropical forest. We combined biological, physical, and chemical methods to characterise SOC along a gradient of bioavailability. After 13 years of monthly litter addition treatments, most of the additional SOC was readily bioavailable and we observed no increase in mineral-associated SOC. Importantly, SOC with weak association to soil minerals declined in response to long-term litter addition, suggesting that increased plant inputs could modify the formation of organo-mineral complexes in tropical soils. Hence, we demonstrate the limited capacity of tropical soils to sequester additional C inputs and provide insights into potential underlying mechanisms.

Real World Population-Based Exploration of the Pathology Subtyping and Treatment-Modalities of Diffuse Large B-Cell Lymphoma in Belgium in Relation to Survival

Objective We report on the real world population-based study of patterns of care of DLBCL in Belgium (2013-2015) with a specific focus on the elderly population. Methods The Belgian Cancer Registry (BCR) collects, processes and analyses data on all new cancers diagnosed in Belgian residents by independent collection of double input: oncological care programs and pathology reports. Coded data were thus obtained of all adult (≥ 20 year) DLBCL diagnosed between 2013 and 2015 (n=1,890). From pathology reports we extracted immunohistochemistry (IHC) expression of CD10, BCL2, BCL6, IRF4 and MYC proteins, cell of origin (COO) classification estimated by Hans algorithm and BCL2, BCL6 or MYC gene translocation by FISH and/or PCR. Belgian health insurance data were used to infer DLBCL treatment modalities (chemotherapy schemes based on the combination of reimbursed drugs, HSCT and/or radiotherapy received) as well as to assess comorbidities. First-line treatments were grouped into 3 main categories: "standard" R-CHOP (≥6 or ≥4 cycles if Ann-Arbor = 1, including R-miniCHOP); other anthracycline containing schemes (other R-CHOP, CHOP, (R-)ACVBP, (R-)CHOP-like, intensified regimens); non-anthracycline treatments (COP and bendamustine schemes, palliative treatments). Results COO was available in 63% of cases; KI-67, BCL2, BCL2 &amp; MYC expressions in 58%, 62% and 16% of cases respectively; MYC, BCL2 &amp; MYC gene rearrangements in 11% and 9% of cases. Of the evaluable cases, 49% were double expressor (DE) and 10% were double-hit DLBCL (FISH only performed in ±10%). The negative prognostic markers identified from univariable models were: age, WHO PS, Ann-Arbor stage, non-GCB COO, MYC rearrangement, BCL2 expression, BCL2/MYC DE, comorbidities, other malignancies. First line systemic treatment was started in 84% of patients (Rituximab-containing in 96%) divided in standard R-CHOP (52%), other anthracycline schemes (39%) and non-anthracycline regimens (10%). The median [IQR] delay from diagnosis to treatment was 19 [9-31] days. In 18% of treated patients 2nd line therapy was initiated for refractory (10%) or relapsed disease (8%). This contained either a platinum-derivative (with or without cytarabine), HD cytarabine, anthracycline or bendamustine in 54%, 6%, 6 and 3% of cases respectively. Autologous HSCT was performed in 67 patients (BEAM-like conditioning in 88%), allogeneic HSCT in only 4 cases (&lt; 65 yr-old). Importantly 56% of patients were ≥ 70 yr-old (transplant-ineligible) and 44% ≥ 80 yr-old (unfit for intensive treatments). In patients older than 80 (and +85) years, no systemic treatment was administered in 38% (57%) of which 27% did receive radiotherapy. First line treatment was started in 62% (43%): "standard" R-(mini)CHOP in 22% (11%); other anthracycline schemes in 23% (13%) and non-anthracycline regimens in 17% (19%) (Table 1). In this elderly population treated with R-CHOP, the median number of cycles and interval still remained 6 and 21 days showing feasibility of dose-dense therapy. Second line therapy was started in 6% and no HSCT was performed. The 2-yr overall survival [95% IC] between the different age categories [20-59], [60-69], [70-79], [80-84] and ≥85 yr-old were 84 [80-87], 74 [69-78], 62 [58-66], 44 [38-49] and 31 [25-36], respectively (Figure 1). Survival curves of treatments by age categories showed that the older patients [70-84 yr-old] still benefit from the R-(mini)CHOP treatment (Figure 2). In the multivariable analyses the following variables were associated with a significant hazard ratio: sex, age, WHO PS, respiratory comorbidity, tumor history &gt; 1,5 year after diagnosis, "standard" R-CHOP treatment. Conclusions This real world population-based study allows to assess patients usually excluded from clinical trials (elderly population, patients with comorbidities including malignancies (13%). Although limitations due to treatment inference and to the absence of some prognostic markers, this real world analysis of diagnostic-work up and inference of treatment modalities of DLBCL in Belgium showed that the disease characteristics of the elderly population did not seem to be different from the younger population. The majority (63%) of older patients [70-84 yr-old] are started on first line treatments with curative intent. Our study suggests that a substantial fraction of this elderly population qualifies for standard R-(mini)CHOP treatment and benefits from it. Disclosures No relevant conflicts of interest to declare.

Analysis on the Force and Life of Gearbox in Double-Rotor Wind Turbine

In order to study the force and life of the key components in the gearbox of an existing double-rotor wind turbine, the design and structural parameters of the gearbox in the traditional National Renewable Energy Laboratory (NREL) 5 MW single-rotor wind turbine are adopted, and the fixed ring gear of the first planetary stage transmission is released to form a differential gearbox suitable for a double-rotor wind turbine with two inputs. The double input is used to connect the double rotor. Subsequently, the characteristics of the gearbox in a double-rotor wind turbine are discussed. On the basis of the constant rated power of the whole wind turbine, the total power is divided into two parts, which are allocated to the double rotors, then two rotational speeds of the two inputs are given according to different power ratios by complying with the matching principle of force and moment. Furthermore, the force acting on the pitch circle of the planet gear, as well as the force and life of the planet bearing of the two-stage planetary transmission are calculated and compared with a single-rotor wind turbine. The results show that the structural advantages of a double-rotor wind turbine can reduce the stress of key components of the gearbox and increase the life span of the planet bearing, thereby the life of the whole gearbox is improved and the downtime of the whole wind turbine is reduced.

Suppression of Synchronous Current Using Double Input Improved Adaptive Notch Filter Algorithm

In order to suppress the influence of the synchronous vibration generated by the unbalance of magnetically suspended control moment gyro on the attitude control accuracy and stability of the satellite platform, this article first introduces the working principle of the magnetically suspended high-speed rotor system, and also establishes the dynamic model of the magnetically suspended rotor with unbalance mass. At the same time, the main sources of unbalance vibration are also analyzed. Finally, an improved adaptive notch filter based on double input is designed. The filter takes the rotor radial X, Y two-channel displacement sensor signals as inputs, and uses the characteristics orthogonal to each other to simultaneously enter the system. The rotor can be automatically balanced by adjusting the convergence factor and the compensation angle to adaptively suppress the synchronous current in a widely operating speed range. Simulation and experimental results show that the method can effectively eliminate the synchronous current in a widely operating speed range and improve the stability of the system. This research on the microvibration of the rotor is of great significance and application value.

Paperless Safety Lifecycle

To ensure the functionality of safety systems in plants, maintenance is required. Plant operators are obliged to perform inspections, evaluate the results and archive the protocols.Inspection plans and intervals vary deeply depending on the kind of equipment, the legal basis and the standards that are taken into account. Safety integrated systems according to IEC 61508/61511 have to fulfil a certain safety integrity level (SIL). The proof-test interval amounts into the SIL calculation. A typical interval is twelve month, which leads to frequent inspections. Equipment for hazardous areas in terms of explosion protection also needs to be inspected periodically. Depending on national legislation, a typical interval can be 36 Month. Other equipment types, especially mechanical equipment also needs to be inspected periodically, e.g. pipe systems and pressure vessels.Inspections in general lead to a huge amount of effort for all affected people due to many different issues.Carrying out an inspection in a lowly digitalized environment can cost a lot of time, as checklists have to be administrated, printed, filled in, scanned and evaluated by many manual actions. The Digitalization offers opportunities for plant operators by introducing paperless workflows. Another opportunity is to reduce the effort that employees have in keeping all the different IT-systems resulting from the plant's life cycle up to date. In the engineering phase, CAE- and Engineering systems are in use to manage equipment. During the operation of the Plant, ERP-Systems and document management systems (DMS) must be taken into account. Double data input in all systems can cause mistakes, a poor data quality in general and it requires additional time. A highly digitalized environment can help the operator to solve the conflict between time, quality and costs.

Unbalanced Voltage Suppression in a Bipolar DC Distribution Network Based on DC Electric Springs

In this paper, a method is proposed to mitigate unbalanced voltage and reduce power losses due to neutral line current in a bipolar direct current (DC) distribution network by introducing a DC electric spring (DC-ES). The coupling relationship between positive and negative pole voltages are investigated given the resistance of neutral line in the bipolar DC distribution network. The coupling matrixes of the positive and negative pole voltages and the DC-ES output voltages are deduced. And this matrixes demonstrate that the DC-ES control system is composed of double inputs of pole voltages and double outputs of DC-ES voltages. The small-signal model of the bipolar DC distribution network with DC-ESs is derived further. Subsequently, the control system with double inputs and outputs is transformed into two independent control systems by introducing the decoupling control variables, thereby increasing its rapidity and anti-interference performance significantly. The proposed unbalanced voltage suppression method and decoupling control of DC-ESs are validated by simulations and experiments.

Analytical analysis and simulation on fringe field effect of deflector plates applied in ultrafast electron microscopy

Deflector plates are one of the critical components in ultrafast electron microscope (UEM), which generates the short electron pulse. While the electron pulse can be stretched due to the velocity dispersion induced by the fringe field of the deflector plates, understanding the effect of the fringe field on the electron velocity and how to avoid the adverse effect of it are needed in the design of the deflector plates. In this paper, firstly, an analytical model of the fringe field of deflector plates with double field input is given. This analytical model can be adapted to other new designs with different double field inputs, and as an example, the velocity dispersion, stretched time, and energy gain of an electron pulse are calculated with a linear double field input. Secondly, three sets of particle tracing simulations on electron velocities have been studied in terms of different single field inputs. The simulated results show that the longitudinal velocity of the electron changes very differently as a result of the different voltage sign on the deflector plates. In our model, the longitudinal velocity is almost constant until the electron leaves the deflector plates. So the results suggest that the deflector plates with double field input are recommended not only in UEM setups but also in other charged particle beam setups where needs high deflection accuracy.

A Novel Offset and Finite-Gain Compensated Switched-Capacitor Amplifier with Input Correlated Level Shifting

A novel offset and finite-gain compensated differential switched-capacitor(SC) amplifier is presented. Incorporating the correlated double sampling (CDS) technique and input correlated level shifting (CLS) technique together, the DC offset and DC gain error of SC amplifier are further reduced by a factor of op-amp DC gain compared with the conventional offset and finite-gain compensated SC amplifier. The effectiveness of the new scheme has been analyzed and verified by extensive simulations. An SC amplifier with the proposed scheme is designed in 130 nm CMOS technology. Simulated results show that with an op-amp having a low DC gain of 30 dB and an input offset of 10 mV, the proposed SC amplifier achieves an output offset and DC-gain error of 154 µV and 0.05%, respectively, which are significantly improved compared with 1.155 mV and 0.42% achieved in the conventional SC amplifier.

2.4 GHz SQUARE RING PATCH WITH RING SLOT ANTENNA FOR SELF INJECTION LOCKED RADAR

Abstract: The radar network system requires high-cost frequency, the complex configuration component of the electromagnetic feeding network circuit to make four output antenna with the same power and different phase output specifically for SIL (Self Injection Locked) Radar, and inexpensive material, especially for the electromagnetic component. 2.4 GHz Square Ring Patch with Ring Slot Microstrip Antenna with four output that has the same power using power divider and 90-degree phase different output for SIL Radar. this is the novel shaped microstrip Antenna with the free frequency, more unassuming configuration, and inexpensive material at the 2.4 GHz for SIL Radar. This system is an important part component of SIL Radar that is package consists of a 2.4 GHz Microstrip antenna with the Square Ring Patch with Ring Slot, double power divider which is double input with quad output with the same power and directional coupler 90-degree phase difference with two input and two output. The Antenna has single band and narrow bandwidth with the frequency is 2.38 GHz until 2.43 GHz under -10dB S parameter and frequency resonance 2.4 GHz, the radiation pattern is directional and the gain is 8.37 dBi, The Power divider has S parameter 2 port output of one part under -20dB at 2.4 GHz and isolation above -4dB that is all good agreement. The 90-degree hybrid coupler has S35 of -35.95dB, S46 of 35.09, S53 of -3.47, and S64 of -3.39 that all is qualified good operation. And overall size of the proposed antenna system is 100 mm times 55.7 mm with FR4 (Phenolic White Paper) with a dielectric constant is 4.4 that has 50ohm. DOI : https://doi.org/10.26905/jeemecs.v2i2.3253

Application of a multi-input multi-output (MIMO) nonlinear non-minimum phase system control method to hydro turbine unit

In this paper, in view of the non minimum phase characteristics of hydraulic turbine unit, a method of designing the controller of multi-input multi-output (MIMO) nonlinear non-minimum phase system is proposed and applied to hydraulic turbine unit system described by double control input fifth order model. The turbine output electromagnetic power and generator power angle are stabilized by wicket gate opening and excitation combined control. Firstly, the method for designing the controller of multi-input multi-output (MIMO) nonlinear non-minimum phase system is introduced. The method is based on state feedback theory, pole assignment theory and Lyapunov stability theory. Secondly, the control law of hydro turbine unit is given according to the method. Results of simulation indicate that this nonlinear non-minimum phase controller has a good effect when applied to the hydro turbine unit.

A Double Input RF Energy Harvesting Circuit Using Wilkinson Power Combiner and DC Load Analysis of the Circuit

Kablosuz iletişim sistemlerinden ortama pek çok frekansta sinyaller yayılmaktadır. Enerji hasatlama, ortamdaki bu anlık olarak var olan sinyallerin enerjisini alarak doğru akım ve gerilime dönüştürme işidir. Bu çalışmada, Wilkinson güç birleştirici kullanarak bir enerji hasatlama devresi tasarlanmıştır. Önerilen devre; iki koldan aldığı sinyalleri birleştirerek Greinacher doğrultma devresine aktarmaktadır. Tasarımın merkez frekansı; ISM bandını kapsaması için 2,45 GHz olarak seçilmiştir. Tasarlanan devrenin Giriş Gücü-Verim ve Giriş Gücü-Çıkış gerilimi analizi yapılmıştır. Ayrıca, yük direncinin değişen değerlerin göre de bu analizler tekrarlanmıştır. Sonuçta en iyi performans; 9 dBm giriş gücü ve 200 Ohm yük direnci için yaklaşık %68 toplam dönüştürme verimi ve 1 Volt çıkış gerilimi elde edilmiştir.