Dual-channel System Research Articles

Bilateral orthogonality generative acquisitions method for homogeneous images using parallel transmission at 7 T.

The novel bilateral orthogonality generative acquisitions method has been developed for homogeneous images without the effects of transmit field inhomogeneity using a parallel-transmission (pTx) system at 7 T. A new method has been introduced using four low-angle gradient-echo (GRE) acquisitions to obtain homogeneous contrast by removing the effects of transmit field inhomogeneity in the pTx system. First, two input images are obtained in circularly polarized mode and another mode in which the first transmit channel or channel group have an additional transmit phase of π. The last two acquisitions are single-channel acquisitions for a dual-channel system or single-channel group acquisitions for more than two channels. The introduced method is demonstrated in dual-channel and eight-channel pTx systems using phantom and whole-brain in vivo experiments. Noise performance of the proposed method is also tested against the ratio of two GRE acquisitions and the TIAMO (time-interleaved acquisitions of modes) method. Th new method results in more homogeneous contrast in the final images than the compared methods, particularly in the low-intensity regions of circularly polarized-mode images for the images obtained via ratio of the two GRE acquisitions. The introduced method is easy to implement, robust, and provides homogeneous images of the whole brain using pTx systems with any number of channels, compared with the ratio of the two GRE images and the TIAMO method.

Adoption strategies of E-commerce consumer credit services: A dual-channel competition perspective

This paper investigates the adoption strategy of e-commerce consumer credit services (e-CCS) and its impact on pricing strategies of a dual-channel system consisting of a wholesale platform, an agency platform, and a common supplier. We analyze the interaction between e-CCS strategies and channel modes by constructing a game model with four subgame scenarios: neither channel implements e-CCS (NN), only the wholesale channel provides e-CCS (IN), only the agency channel offers e-CCS (NI), both channels launch e-CCS (II). Our findings reveal that channel forms and e-CCS features significantly influence the adoption of e-CCS. Interestingly, the key influencing factors vary among decision makers. Specifically, the wholesale platform is willing to launch e-CCS as long as the demand benefit is prominent, while the agency platform only offers the service when the bad debt risk rate is mild. Moreover, when the agency platform provides e-CCS, the supplier accepts to use it only when there is a substantial demand benefit. Counterintuitively, we also find that the adoption of e-CCS can generate a positive spillover effect on the rival platform, leading to a “win-win” situation. In addition, we examine the impact of e-CCS on pricing decisions. Our findings indicate that the supplier and the wholesale platform may adopt distinct pricing strategies to address higher bad debt risk. Finally, we demonstrate the robustness of our main findings to investigate the impact of competition intensity, the correlation between demand benefit and price, negative externalities on demand benefit, and consumer heterogeneity on e-CCS.

Biosynthesis of D-1,2,4-butanetriol promoted by a glucose-xylose dual metabolic channel system in engineered Escherichia coli

D-1,2,4-butanetriol (BT) is a widely used fine chemical that can be manufactured by engineered Escherichia coli expressing heterologous pathways and using xylose as a substrate. The current study developed a glucose-xylose dual metabolic channel system in an engineered E. coli and Combinatorially optimized it using multiple strategies to promote BT production. The carbon catabolite repression effects were alleviated by deleting the gene ptsG that encodes the major glucose transporter IICBGlc and mutating the gene crp that encodes the catabolite repressor protein, thereby allowing C-fluxes of both glucose and xylose into their respective metabolic channels separately and simultaneously, which increased BT production by 33% compared with that of the original MJ133K-1 strain. Then, the branch metabolic pathways of intermediates in the BT channel were investigated, the transaminase HisC, the ketoreductases DlD, OLD, and IlvC, and the aldolase MhpE and YfaU were identified as the enzymes for the branched metabolism of 2-keto-3-deoxy-xylonate, deletion of the gene hisC increased BT titer by 21.7%. Furthermore, the relationship between BT synthesis and the intracellular NADPH level was examined, and deletion of the gene pntAB that encodes a transhydrogenase resulted in an 18.1% increase in BT production. The combination of the above approaches to optimize the metabolic network increased BT production by 47.5%, resulting in 2.67 g/L BT in 24 deep-well plates. This study provides insights into the BT biosynthesis pathway and demonstrates effective strategies to increase BT production, which will promote the industrialization of the biosynthesis of BT.

Traceable Calibration of Atmospheric Oxidized Mercury Measurements.

Most previous measurements of oxidized mercury were collected using a method now known to be biased low. In this study, a dual-channel system with an oxidized mercury detection limit of 6-12 pg m-3 was deployed alongside a permeation tube-based automated calibrator at a mountain top site in Steamboat Springs Colorado, USA, in 2021 and 2022. Permeation tubes containing elemental mercury and mercury halides were characterized via an International System of Units (SI)-traceable gravimetric method and gas chromatography/mass spectrometry before deployment in the calibrator. The dual-channel system recovered 97 ± 4 and 100 ± 8% (±standard deviation) of injected elemental mercury and HgBr2, respectively. Total Hg permeation rates and Hg speciation from the gravimetric method, the chromatography system, the dual-channel system, and an independent SI-traceable measurement method performed at the Jožef Stefan Institute laboratory were all comparable within the respective uncertainties of each method. These are the first measurements of oxidized mercury at low environmental concentrations that have been verified against an SI-traceable calibration system in field conditions while sampling ambient air, and they show that accurate, routinely calibrated oxidized mercury measurements are achievable.

Development and investigation of algorithm for the synthesis of an automatic control system of the drying process

At the first stage of research, the experimental transmission functions and optimal two-channel automatic adjustment system (ARS) of the residual moisture content during convection drying of apples were developed. As a result of the analysis of the structural synthesis of the ARS, the advantage of the optimal dual-channel ARS compared to the single-channel system was established. At the second stage of research, with a view to improving the quality of the single-channel speed ARS of the residual moisture content of apples, the robust ARS was developed by the method of parametric synthesis and root hodograph. Based on the research, the advantages of the speed single-channel robust system compared to the dual-channel system were established, which will significantly improve the quality of the products and reduce energy consumption for drying.

Monitoring & healing dual channel system designed for continuous glucose monitoring decorated with high-efficient self-healing CuO nanoflakes glucose catalytic electrode

Continuous glucose monitoring (CGM) system provides diabetics with an extremely attractive alternative in controlling blood glucose level. Compared with enzymatic and noble meal-based electrode, copper-based electrode presents a better stability and anti-interference property, which is more suitable to be applied in CGM system for long-term working. The investigation of the failure behavior of copper-based electrode is of vital importance for the application in CGM system. In this paper, the damaged mechanism of copper-based electrode was investigated by analyzing the variation of structure and catalytic properties of CuO nanoflakes (NFs) electrode after long-term working. The results indicated that the main reason for the failure of CuO NFs electrode was structure damage. Copper anodization is an effective electrochemical method to construct the nanostructured film in situ and was used to repair the damaged structure. Based on the damaged mechanism of the copper-based catalytic electrode and the dissolution-precipitation mechanism of copper anodization, a monitoring & healing dual channel (M&H) system decorated with highly efficient self-healing CuO NFs electrode was designed for CGM system. The M&H system enable the monitoring and healing process to be achieved by only adjusting the working potential in the same supporting electrolyte (0.1 M NaOH aqueous), which greatly facilitates glucose measurement and has instructive significance for engineering applications in commercial glucose sensors.

Gains and Losses of Key Opinion Leaders’ Product Promotion in Livestream E-commerce

In livestream e-commerce, many brand-owners use the key opinion leaders (KOLs) for product promotion and sales, especially in the direct-selling channel. Is such a practice really beneficial to the brand-owner? In practice, we even observe that KOLs sell and then return products for a strong network externality. Therefore, to formulate the brand-owner's tradeoffs of using KOLs, we compare the brand-owner's profits with and without a KOL (i.e., brand-owner uses a KOL for product promotion vs. brand-owner invests in product promotion by itself) in a dual-channel system comprised of the brand-owner's direct-selling channel and its traditional retail channel. We find the brand-owner's gains/losses of using the KOL highly depend on the commission rate, retain rate and the network externality intensity. Interestingly, we reveal that the enhanced KOL effect might not be necessarily beneficial to the brand-owner and can even hurt it significantly. As the channel rival, the retailer may benefit from the brand-owner's using the KOL (because its procurement cost may be lowered) and the market expansion (because the use of KOL may spill over to the retail channel).

Enhanced Frequency Stability of SAW Yarn Tension Sensor by Using the Dual Differential Channel Surface Acoustic Wave Oscillator.

This paper presents a 60 MHz surface acoustic wave (SAW) yarn tension sensor incorporating a novel SAW oscillator with high-frequency stability. A SAW delay line was fabricated on ST-X quartz substrate using the unbalanced-split electrode and bi-directional engraving slots. The dual differential channel delay linear acoustic surface wave oscillator is designed and implemented to test yarn tension, which can effectively remove the interference of temperature, humidity, and other peripheral factors through differential design. The yarn tension sensor using the surface acoustic wave has high-precision characteristics, and the SAW delay line oscillator is designed to ensure the test system’s stable operation. The effect of time and tension on oscillator frequency stability is studied in detail, and the single oscillator and the dual differential channel system were tested, respectively. After using the dual differential channel system, the short-term frequency stability from is reduced from 1.0163 ppm to 0.17726 ppm, the frequency accuracy of the tension sensor is improved from 134 Hz to 27 Hz, and the max frequency jump steady is reduced from 2.2395 ppm to 0.45123 ppm.

A Simple Photonic System for DFS and AOA Simultaneous Measurement

A simple photonics-based dual-channel system is proposed to simultaneously measure the Doppler frequency shift (DFS) and angle of arrival (AOA) of microwave signals. The system applies two parallel push–pull Mach–Zehnder modulators (MZMs) for carrier suppression dual-sideband (CS-DSB) modulation. The introduction of the reference signal results in a DFS measurement without direction ambiguity. The DFS can be determined by measuring the frequency of the down-converted intermediate frequency (IF) signal, and the AOA can be calculated by comparing the phase shift of the two channels. A proof-of-concept experiment shows that the DFS measurement error is less than 0.4 Hz during ±100 kHz, and the AOA measurement error is within 1.5° in a range of 0–70°.

Optical image encryption based on two-channel detection and deep learning

Aside from its application to the vulnerability analysis of optical cryptosystems, deep learning (DL) technique can also be used as a potential basis for optical cryptography itself. Here, we report a new optical image encryption scheme based on two-channel detection and DL. The encryption process consists of two-channel signal detection within the optical encryption system where three random binary masks are involved, and the training of a neural network to derive an approximate model. The two optically encoded patterns collected with a pair of CCD cameras are recombined into a single speckle image by using two independent sparse matrices. In the training section, the neural network is trained to find the mapping relationship between the speckle images and their corresponding original objects. Besides the model parameters, the decryption requires the use of the matrix keys, which avoids a situation where the DL-based cryptosystem is designed such that security relies entirely on the trained network itself. To the best of our knowledge, this is the first report using a single-wavelength, dual-channel system for diffuse optical encryption. Experimental results demonstrate the feasibility and good performance of the proposed scheme.

Research on the Robustness of Active Headrest with Virtual Microphones to Human Head Rotation

The movement and rotation of the human head can significantly degrade the control performance of active headrests with virtual microphones. This paper investigates the performance robustness of an active headrest with virtual microphones against the head rotation in a pure tone diffracted diffuse sound field. A physical model of a headrest system with a diffractive sphere is firstly developed, based on which the influence of acoustic transfer responses on the performance robustness against head rotation is analyzed. Then, the multi-objective optimization with constraints is developed to improve the performance robustness of the system, by designing optimized plant responses. Simulation results show that the method is effective in improving the robustness of single and dual channel systems. For a dual-channel headrest system with the proposed arrangements of secondary sources and microphones, the promotion of the minimum noise reduction is more than 7 dB after optimization when the head rotates from −90 degrees to 90 degrees at 125 Hz, 250 Hz and 500 Hz. In addition, the influence of different parameters on the optimization method is discussed for this dual-channel system. Finally, experiments carried out in an ordinary room validate the effectiveness of the proposed method.

Application of Bone Marrow-Derived Macrophages Combined with Bone Mesenchymal Stem Cells in Dual-Channel Three-Dimensional Bioprinting Scaffolds for Early Immune Regulation and Osteogenic Induction in Rat Calvarial Defects.

The host immune response to biomaterials is critical for determining scaffold fate and bone regeneration outcomes. Three-dimensional (3D) bioprinted scaffolds encapsulated with living cells can improve the inflammatory microenvironment and further accelerate bone repair. Here, we screened and adopted 8% methacrylamidated gelatin (GelMA)/1% methacrylamidated hyaluronic acid (HAMA) as the encapsulation system for rat bone marrow-derived macrophages (BMMs) and 3% Alginate/0.5 mg/mL graphene oxide (GO) as the encapsulation system for rat bone mesenchymal stem cells (BMSCs), thus forming a dual-channel bioprinting scaffold. The 8% GelMA/1% HAMA/3% Alginate/0.5 mg/mL GO (8/1/3/0.5) group could form a scaffold with a stable structure, good mechanical properties, and satisfied biocompatibility. When exploring the crosstalk between BMMs and BMSCs in vitro, we found that BMSCs could promote the polarization of BMMs to M2 type at the early stage, reduce the pro-inflammatory gene expression, and increase anti-inflammatory gene expression; conversely, BMMs can promote the osteogenic differentiation of BMSCs. In addition, in the model of rat calvarial defects, the dual-channel scaffold encapsulated with BMMs and BMSCs was more effective than the single-cell scaffold and the acellular scaffold. The paracrine of BMMs and BMSCs in the biodegradable dual-channel scaffold effectively promoted the M2-type polarization of macrophages in the microenvironment of early bone defects, avoided excessive inflammatory responses, and further promoted bone repair. In conclusion, our findings suggested that using 3D bioprinting to simultaneously encapsulate two primary cells of BMMs and BMSCs in a dual-channel system may be an effective way to promote bone repair from the perspective of early immune regulation and late induction of osteogenesis.

Willingness-to-pay experimental model for Stackelberg dual channel pricing decision

PurposeThis study proposes and demonstrates a novel approach to analyzing customer channel preferences and willingness-to-pay (WTP) in the dual sales channel (DSC) system involving direct online channels and conventional offline retailers, and to how the pricing decisions are made under specific game competition.Design/methodology/approachQuestionnaire survey based on central composite experiment design was utilized to obtain primary data. The model for customer channel preferences and WTP was then built by using multinomial logistic regression. The propensity of a customer to make purchases in either channel estimated by using the logit model was inserted in the bilevel programming model to formulate and solve for the Stackelberg competition where the conventional retailer acted as a leader.FindingsThe study found that channel prices have nonlinear impacts on WTP and channel preference. The empirical results complement the mathematical formulation well where high-order own-price and cross-price effects on channel selection are generally not analytical tractable. Under the Stackelberg competition, the traditional retailer (as the leader) still achieves higher profits than the online facility.Practical implicationsThe proposed framework provides an empirical approach that can easily address the competition model in the sales channel when complicated own-price or cross-price effects are present.Originality/valueThe present work provides a novel approach to analyze customer preference and WTP of the DSC systems. This alternative method simplifies the procedure for investigating and estimating price sensitivity, especially when the online and offline prices affect customer WTP and channel preferences nonlinearly. This model is also utilized in the game competition to facilitate data-driven price decision making to better formulate and understand real-world DSC problems.

A novel dual-channel brain tumor detection system for MR images using dynamic and static features with conventional machine learning techniques

Brain tumor detection, at the early stages of its development for the timely cure of the patient, is a challenging task due to its complex nonlinear nature. We propose a dual-channel brain tumor detection (DC-BTD) framework for magnetic resonance imaging scans with optimum false negatives, based on the idea of using D-channel for extremely discriminant dynamic features and S-channel for static features using data normalization, augmentation, and different machine learning (ML) classifiers, namely, support vector machine, k-nearest neighbor, naïve Bayes, and XGBoost. The D-channel features are extracted using a proposed Fine-Tuned Convolutional Neural Network (FT-CNN), while the S-channel features are extracted using the histogram of oriented gradients (HOG)- and local binary patterns (LBP)-based operators. The dual-channel data form the hybrid feature space (HFS) gives improved performance using two types of features. Computer experiments have been conducted on publically available brain tumors dataset obtained from Nanfang Hospital, Guangzhou, and Tianjin Medical University General Hospital, China. The finding of the current study shows that the proposed framework for brain-tumor prediction outperforms other contemporary existing methods with the highest generalization performance as 98.70% (accuracy) and 98.56% (F score) on the same dataset that can lead to better brain tumor detection at an early stage. Highlights A novel DC-BTD system is proposed using a competitive ML algorithm The dynamic channel is based on a new fine-tuned deep learning architecture The static channel is based on extremely discriminative textural features using HOG and LBP operators The HFS is formed by the dynamic and static channels

How cooperative advertising interacts with distributional contracts in a dual-channel system

With the development of E-commerce, an increasing number of online platforms are conducting advertising campaigns to expand their sales. In some situations, the manufacturer is willing to share the advertising cost, while in others it is not. Additionally, recently, many online platforms have started choosing an agency contract, instead of a wholesale contract, to obtain a predetermined proportion of revenue from the manufacturer to make profits. This paper studies a scenario of a manufacturer selling through both a direct channel and a platform channel to investigate the interaction between a manufacturer’s cooperative advertising strategy and a platform’s distribution contract choice. We develop a stylized model based on game theory to drive the optimal prices and advertising level under different contracts. By using a representative consumer function, we drive the following interesting results. Firstly, under the wholesale contract, a manufacturer prefers cooperating only when the cost-sharing rate is small, but under an agency contract, when the revenue-sharing rate is large, the manufacturer will not choose to cooperate even if the cost-sharing rate is low. Secondly, the platform’s profit does not always increase in the revenue-sharing rate. Finally, under some conditions, the platform would prefer that the manufacturer not share the cost. Specifically, when the competition intensity is small and the revenue-share rate is high, the platform would rather choose an agency contract to cover all advertising costs on its own than a wholesale contract where the manufacturer is willing to share advertising costs. We also consider direct channel advertising as well in an extension, and the qualitative results still hold.

A BERT based dual-channel explainable text emotion recognition system

In this paper, a novel dual-channel system for multi-class text emotion recognition has been proposed, and a novel technique to explain its training & predictions has been developed. The architecture of the proposed system contains the embedding module, dual-channel module, emotion classification module, and explainability module. The embedding module extracts the textual features from the input sentences in the form of embedding vectors using the pre-trained Bidirectional Encoder Representations from Transformers (BERT) model. Then the embedding vectors are fed as the inputs to the dual-channel network containing two network channels made up of convolutional neural network (CNN) and bidirectional long short term memory (BiLSTM) network. The intuition behind using CNN and BiLSTM in both the channels was to harness the goodness of the convolutional layer for feature extraction and the BiLSTM layer to extract text’s order and sequence-related information. The outputs of both channels are in the form of embedding vectors which are concatenated and fed to the emotion classification module. The proposed system’s architecture has been determined by thorough ablation studies, and a framework has been developed to discuss its computational cost. The emotion classification module learns and projects the emotion embeddings on a hyperplane in the form of clusters. The proposed explainability technique explains the training and predictions of the proposed system by analyzing the inter & intra-cluster distances and the intersection of these clusters. The proposed approach’s consistent accuracy, precision, recall, and F1 score results for ISEAR, Aman, AffectiveText, and EmotionLines datasets, ensure its applicability to diverse texts.

Effect of Fiber-Telescope Coupling Losses on Wideband Wavelength Division Multiplexing in Free Space Optical Communications

The effect of telescope losses (TL) on wideband wavelength division multiplexing (Wideband-WDM) based on free-space optical communication (FSOC) is investigated via OptiSystem software. In this work, both single and dual channel FSOC systems are investigated under different communication weathers: clear, haze, rain, and fog with attenuation losses of 0.2 dB/km, 2.3 dB/km, 4.3 dB/km, and 8.0 dB/km, respectively. The TL measures the coupling efficiency between the fiber and telescope in the transceiver assembly; therefore, is considered an important design parameter for the FSOC and hybrid optical communication system. According to the results, the maximum TL is 23 dB and 29 dB for single and dual FSOC, respectively, at the clear weather condition and for 1 km communication distance. This means that the dual-channel system could afford higher losses than the single system by approximately 26.1 %. Furthermore, this ratio is approximately the same for the other weather conditions, 28.6 %, 31.6 %, and 40 % for the hazy, rain, and fog weather, respectively.

Rapid detection of HPV16/18 based on a CRISPR-Cas13a/Cas12a dual-channel system.

cervical cancer is the leading cause of cancer deaths in women in the developing world, with high-risk HPV16 and HPV18 accounting for approximately 70% of all cervical cancers. Early detection of HPV, especially high-risk HPV types, is essential to prevent disease progression. in this study, we established a highly sensitive and specific nucleic acid assay based on a CRISPR-Cas13a/Cas12a dual-channel system combined with multiplex RAA for rapid detection and typing of HPV16/18, which provides a new idea for cervical cancer screening. To meet the application of field testing, we designed a portable fluorescence imaging assay that can judge the test results directly with the naked eye or through cell phone imaging. the lower limit of detection for both HPV16 and HPV18 based on the CRISPR-Cas12a/Cas13a dual-channel assay was 100 copies per μL. The dual-channel assay was validated with 55 clinical samples, showing 97.06% sensitivity, 100% specificity, 100% positive predictive value, and 96.55% negative predictive value. The results of the portable fluorescence imaging assay were fully comparable to those of the real-time fluorescent RAA-based CRISPR-Cas12a/Cas13a dual-channel assay. this developed portable dual gene assay platform may provide new technical support for cervical cancer screening in resource-limited settings.

New dual-channel system records lineage in high definition.

New dual-channel system records lineage in high definition.

New Channel Errors Estimation Method for Multichannel SAR Based on Virtual Calibration Source

The multichannel synthetic aperture radar (SAR) system can effectively overcome the fundamental limitation between high-resolution and wide-swath. However, the unavoidable channel errors will result in a mismatch of the reconstruction filter and false targets in pairs. To address this issue, a novel channel errors calibration method is proposed based on the idea of minimizing the mean square error (MMSE) between the signal subspace and the space spanned by the practical steering vectors. The practical steering matrix of each Doppler bin can be constructed according to the Doppler spectrum. Compared with the time-domain correlation method, the proposed method no longer depends on the accuracy of the Doppler centroid estimation. Besides, compared with the orthogonal subspace method, the proposed method has the advantage of robustness under the condition of large samples by using the diagonal loading technique. To evaluate the performance, the results of simulation data and the real data acquired by the GF-3 dual-channel SAR system demonstrate that the proposed method has higher accuracy and more robustness than the conventional methods, especially in the case of low SNRs and high non-uniformity.