Symbol-Level Precoding Design for Max-Min SINR in Multiuser MISO Broadcast Channels

In this paper, we address the symbol level precoding (SLP) design problem under max-min SINR criterion in the downlink of multiuser multiple-input single-output (MISO) channels. First, we show that the distance preserving constructive interference regions (DPCIR) are always polyhedral angles (shifted pointed cones) for any given constellation point with unbounded decision region. Then we prove that any signal in a given unbounded DPCIR has a norm larger than the norm of the corresponding vertex if and only if the convex hull of the constellation contains the origin. Using these properties, we show that the power of the noiseless received signal lying on an unbounded DPCIR is an strictly increasing function of two parameters. This allows us to reformulate the originally non-convex SLP max-min SINR as a convex optimization problem. We discuss the loss due to our proposed convex reformulation and provide some simulation results.Comment: Submitted to SPAWC 2018, 7 pages, 2 figure

Power Minimizer Symbol-Level Precoding: A Closed-Form Sub-Optimal Solution

In this letter, we study the optimal solution of the multiuser symbol-level precoding (SLP) for minimization of the total transmit power under given signal-to-interference-plus-noise ratio (SINR) constraints. Adopting the distance preserving constructive interference regions (DPCIR), we first derive a simplified reformulation of the problem. Then, we analyze the structure of the optimal solution using the Karush-Kuhn-Tucker (KKT) optimality conditions, thereby we obtain the necessary and sufficient condition under which the power minimizer SLP is equivalent to the conventional zero-forcing beamforming (ZFBF). This further leads us to a closed-form sub-optimal SLP solution (CF-SLP) for the original problem. Simulation results show that CF-SLP provides significant gains over ZFBF, while performing quite close to the optimal SLP in scenarios with rather small number of users. The results further indicate that the CF-SLP method has a reduction of order $10^3$ in computational time compared to the optimal solution.Comment: 7 pages, 1 figure, 1 table, submitted to IEEE signal processing letter

The moderating effect of brand orientation on inter-firm market orientation and performance

While prior research has shown that market and brand orientation are key contributors to successful business performance, research to date has not fully explored how inter firm collaboration for these two key orientations can enhance business performance. The purpose of the paper is to investigate the relationship between inter-firm market and performance; to test for the moderating role of brand orientation in that relationship. A total of 169 completed pairs of surveys were collected of small and medium enterprises operating internationally in a variety of industries in Switzerland. The results show that inter-firm market and brand orientation are two antecedents of marketing and financial performance. The impact of inter-firm market on marketing and financial performance is significant when the brand orientation is favorable. This study extends previous research by examining the moderating role of brand orientation on inter firm market orientation, which is important, especially for firms wanting to increase their brand reputation by entering into partnerships with other firms. Further research is indicated, to identify the key moderators of the driving force of inter-firm market in relation to business performance and the reason why maintaining a strong brand presence is important in the international marketplace

Synthesis inequalities for the robust PID controller for a DC Servo motor and Implementation by using digital signal processor

This note considers the ways of obtaining the synthesis equations of the dynamic controller for a DC Servo machine where the closed-loop system poles will move in a -stable region, in spite of the changing system transfer function coefficients by the perturbations. First of all, the mathematical model of a dc servo machine isobtained. Depending upon the varying system transfer function, design equations of the dynamic compensator are found out. These equations includes the ways of choosing the controller coefficients KP, KI, KD which will give a desired response for the tracking system

Mammo-CLIP: A Vision Language Foundation Model to Enhance Data Efficiency and Robustness in Mammography

The lack of large and diverse training data on Computer-Aided Diagnosis (CAD) in breast cancer detection has been one of the concerns that impedes the adoption of the system. Recently, pre-training with large-scale image text datasets via Vision-Language models (VLM) (\eg CLIP) partially addresses the issue of robustness and data efficiency in computer vision (CV). This paper proposes Mammo-CLIP, the first VLM pre-trained on a substantial amount of screening mammogram-report pairs, addressing the challenges of dataset diversity and size. Our experiments on two public datasets demonstrate strong performance in classifying and localizing various mammographic attributes crucial for breast cancer detection, showcasing data efficiency and robustness similar to CLIP in CV. We also propose Mammo-FActOR, a novel feature attribution method, to provide spatial interpretation of representation with sentence-level granularity within mammography reports. Code is available publicly: \url{https://github.com/batmanlab/Mammo-CLIP}.Comment: MICCAI 2024, early accept, top 11

Green network protocols and algorithms

Lloret, J.; Ghafoor, KZ.; Rawat, DB.; Nasser, Y. (2015). Green network protocols and algorithms. Journal of Network and Computer Applications. 58:192-193. https://doi.org/10.1016/j.jnca.2015.11.004S1921935

Mother-infant social gaze dynamics relate to infant brain activity and word segmentation

The ‘social brain’, consisting of areas sensitive to social information, supposedly gates the mechanisms involved in human language learning. Early preverbal interactions are guided by ostensive signals, such as gaze patterns, which are coordinated across body, brain, and environment. However, little is known about how the infant brain processes social gaze in naturalistic interactions and how this relates to infant language development. During free-play of 9-month-olds with their mothers, we recorded hemodynamic cortical activity of ´social brain` areas (prefrontal cortex, temporo-parietal junctions) via fNIRS, and micro-coded mother’s and infant’s social gaze. Infants’ speech processing was assessed with a word segmentation task. Using joint recurrence quantification analysis, we examined the connection between infants’ ´social brain` activity and the temporal dynamics of social gaze at intrapersonal (i.e., infant’s coordination, maternal coordination) and interpersonal (i.e., dyadic coupling) levels. Regression modeling revealed that intrapersonal dynamics in maternal social gaze (but not infant’s coordination or dyadic coupling) coordinated significantly with infant’s cortical activity. Moreover, recurrence quantification analysis revealed that intrapersonal maternal social gaze dynamics (in terms of entropy) were the best predictor of infants’ word segmentation. The findings support the importance of social interaction in language development, particularly highlighting maternal social gaze dynamics

Individual differences in infants' speech segmentation performance: The role of mother‐infant cardiac synchrony

Caregiver-infant coregulation is an early form of communication. This study investigated whether mother-infant biological coregulation is associated with 9-month-olds' word segmentation performance, a crucial milestone predicting language development. We hypothesized that coregulation would relate with infants' word segmentation performance. Additionally, we examined whether this relationship is influenced by the caregiving environment (i.e., parental reflective functioning) and the infant's emotional state (i.e., positive affect). Coregulation was investigated via cardiac synchrony in 28 nine-month-old infants (16 females) during a 5-min free-play with their German-speaking mothers. Cardiac synchrony was measured through Respiratory Sinus Arrhythmia (RSA), employing Recurrence Quantification Analysis to evaluate dyadic coupling (i.e., Recurrence Rate) and dyadic predictability (i.e., Entropy). Infants' word segmentation was measured with an eye-tracking central-fixation procedure. A stepwise regression revealed that higher dyadic coupling, but not predictability, of the dyads' RSA was associated with infants looking longer toward the screen when listening to novel as compared to familiar test words, indicating advanced word segmentation performance (Cohen's d = 0.25). Moreover, cardiac synchrony correlated positively with maternal sensitivity to their infant's mental states, but not with the infant's positive affect. These results suggest that caregiver-infant biological coregulation may play a foundational role in language acquisition

Visual category representations in the infant brain

Visual categorization is a human core cognitive capacity1,2 that depends on the development of visual category representations in the infant brain.3,4,5,6,7 However, the exact nature of infant visual category representations and their relationship to the corresponding adult form remains unknown.8 Our results clarify the nature of visual category representations from electroencephalography (EEG) data in 6- to 8-month-old infants and their developmental trajectory toward adult maturity in the key characteristics of temporal dynamics,2,9 representational format,10,11,12 and spectral properties.13,14 Temporal dynamics change from slowly emerging, developing representations in infants to quickly emerging, complex representations in adults. Despite those differences, infants and adults already partly share visual category representations. The format of infants' representations is visual features of low to intermediate complexity, whereas adults' representations also encode high-complexity features. Theta band activity contributes to visual category representations in infants, and these representations are shifted to the alpha/beta band in adults. Together, we reveal the developmental neural basis of visual categorization in humans, show how information transmission channels change in development, and demonstrate the power of advanced multivariate analysis techniques in infant EEG research for theory building in developmental cognitive science

In vivo function of the murid herpesvirus-4 ribonucleotide reductase small subunit

The difficulty of eliminating herpesvirus carriage makes host entry a key target for infection control. However, its viral requirements are poorly defined. Murid herpesvirus-4 (MuHV-4) can potentially provide insights into gammaherpesvirus host entry. Upper respiratory tract infection requires the MuHV-4 thymidine kinase (TK) and ribonucleotide reductase large subunit (RNR-L), suggesting a need for increased nucleotide production. However, both TK and RNR-L are likely to be multifunctional. We therefore tested further the importance of nucleotide production by disrupting the MuHV-4 ribonucleotide reductase small subunit (RNR-S). This caused a similar attenuation to RNR-L disruption: despite reduced intra-host spread, invasive inoculations still established infection, whereas a non-invasive upper respiratory tract inoculation did so only at high dose. Histological analysis showed that RNR-S−, RNR-L− and TK− viruses all infected cells in the olfactory neuroepithelium but unlike wild-type virus then failed to spread. Thus captured host nucleotide metabolism enzymes, up to now defined mainly as important for alphaherpesvirus reactivation in neurons, also have a key role in gammaherpesvirus host entry. This seemed to reflect a requirement for lytic replication to occur in a terminally differentiated cell before a viable pool of latent genomes could be established