Reception Strategy Research Articles

A welcoming city and nowhere to live: private hospitality and the urban politics of reception in Bologna

ABSTRACT Private hospitality – sometimes referred to as family hosting or homesharing – consists of private citizens hosting migrants for periods ranging from a few weeks to several years. Since 2015, there has been a rapid expansion of active private hospitality initiatives across Europe. Though many programs started as informal housing arrangements coordinated by grassroots organizations, local and state governments are increasingly investing in private hospitality as a reception strategy. This paper focuses on the urban approach to private hospitality in Bologna, Italy, a city with a progressive reputation and a vocal commitment to implementing and innovating programs of migrant reception. I draw from ethnographic fieldwork carried out in 2022 to showcase how Bologna’s urban context and the actions of resident hosts, migrants, and practitioners shape the creation and evolution of private hospitality programs in the city. Though stories of resident-led hospitality can be deployed by municipal administrations as evidence that a city is welcoming, a site of moral urbanism, they also capture the enduring inhospitality of a city where migrants need willing hosts to secure safe and reliable housing.

“Belief Initiates and Guides Action—Or it Does Nothing”: An Exploration of the Political Functions of Watching and Reading Dystopian Fiction

This article addresses the question of how dystopian fiction can produce civic and ideological connections among audiences. To this end, we have drawn from different theoretical perspectives on public connectivity to show how audience involvement with fictional entertainment can forge clear links with the political sphere. In short, we offer a qualitative reception study that has yielded six features of dystopias: cognition, rejection of socially negative themes, warning, speculation, ideology, and narcosis. These features are empirically grounded in extensive qualitative research. Finally, based on the participants’ responses, we have proposed a specific reception strategy for the dystopian genre: dystopian imaginative engagement.

Three-Dimensional Image Transmission of Integral Imaging through Wireless MIMO Channel.

For the reconstruction of high-resolution 3D digital content in integral imaging, an efficient wireless 3D image transmission system is required to convey a large number of elemental images without a communication bottleneck. To support a high transmission rate, we herein propose a novel wireless three-dimensional (3D) image transmission and reception strategy based on the multiple-input multiple-output (MIMO) technique. By exploiting the spatial multiplexing capability, multiple elemental images are transmitted simultaneously through the wireless MIMO channel, and recovered with a linear receiver such as matched filter, zero forcing, or minimum mean squared error combiners. Using the recovered elemental images, a 3D image can be reconstructed using volumetric computational reconstruction (VCR) with non-uniform shifting pixels. Although the received elemental images are corrupted by the wireless channel and inter-stream interference, the averaging effect of the VCR can improve the visual quality of the reconstructed 3D images. The numerical results validate that the proposed system can achieve excellent 3D reconstruction performance in terms of the visual quality and peak sidelobe ratio though a large number of elemental images are transmitted simultaneously over the wireless MIMO channel.

Evaluation of Family Reunification after Foster Care in the State of Minas Gerais - Brazil

Family foster care is intended for the care of children and adolescents who are away from the family by judicial protective measure, emerged as an innovative reception strategy, providing individual and personalized care to children or adolescents who are victims of some form of violence. The present study aimed to brief analyse data from the most recent SUAS census in Brazil, focusing on one of the states of the federation to verify how the referrals of children and adolescents who go through foster care are being carried out. The data showed that in certain places there is discrepancy in reintegration and adoption, the latter being the most common. More effective actions to prepare the families of origin for reunification must be carried out.

Robust Beamformer Design in Active RIS-Assisted Multiuser MIMO Cognitive Radio Networks

In this work, we address the problem of a joint robust transmission, reflection and reception strategy design at an active reconfigurable intelligent surface (RIS)-assisted underlay multiple input multiple output (MIMO) cognitive radio networks in which a secondary transmitter serves multiple secondary receivers simultaneously. As such, we study the impact of imperfection in channel state information (CSI) at the secondary transmitter following a norm-bounded error model. A sum mean squared error (MSE) minimization problem is formulated by jointly optimizing the transmit beamforming matrix (BFM) at the secondary transmitter, the linear reception filters (LRF) at the secondary receivers and the reflection coefficient matrix (RCM) at the RIS subject to the constraints of available transmission power at the secondary transmitter, maximum allowed interference power towards the primary receiver and the permissible amplification range at each RIS element. Due to the coupled nature of the BFM, LRF and RCM variables, the formulated problem is non-convex and, thus, cannot be solved using conventional optimization methods. As a result, we propose an alternating optimization (AO) based iterative algorithm that determines the optimal BFM, LRF and RCM using semidefinite programming and inner approximation methods with guaranteed convergence. We also discuss the impact of the limited power budget at active RIS on the performance of the considered network. We present simulation-based numerical results to validate the efficacy and robustness of the proposed algorithm. Moreover, we also highlight the superiority of the use of the active RIS over passive RIS in the considered communication network.

Wideband 2-D sparse array optimization combined with multiline reception for real-time 3-D medical ultrasound

Three-dimensional (3-D) ultrasound medical imaging provides advantages over a traditional 2-D visualization method. However, the use of a 2-D array to acquire 3-D images may result in a transducer composed of thousands of elements and a large amount of data in the front-end, making it impractical to implement high volume rate imaging and individually control all elements with the scanner. This paper proposes an original approach, valid for wideband operations centered on the design center frequency, to maintain a limited number of active elements and firing events, while preserving high resolution and volume rate. A 7 MHz 2-D array is composed of two circular concentric subparts. In the inner footprint the elements are distributed following a regular grid, while in the outer subpart a sparse non-grid solution is adopted. The inner circular dense array is composed of 256 elements with a pitch of 0.5λ. The overall footprint, delimited by the outer subpart, is equivalent to a 256-element array with a pitch of 1.5λ. All the elements of the inner subpart are activated in transmission. Following an optimization procedure, both subparts, including a subset of the elements placed in the inner footprint (i.e., sparse on-the-grid array) and the elements spread over the outer subpart (i.e., sparse off-the-grid array) are used to receive. A total number of 256 elements, defined by the sum of elements distributed in the inner and outer subparts, is fixed in reception. The proposed approach implies a multiline reception strategy, where for each transmission 3 × 3 firing events occur in reception. The sparse receive array is optimized by using a simulated annealing optimization. An original cost function is designed specifically to achieve successful results in wideband conditions. The receive array is optimized in order to obtain consistent results for different signal bandwidths of the excitation pulse. For all the desired bandwidths, the optimized array will provide the recovery of the lower lateral resolution of the transmission phase and, at the same time, a significant reduction of the undesired side lobe raised in the 3-D two-way beam pattern. The 3-D two-way beam pattern analysis reveals that the proposed solution is able to guarantee a lateral resolution of 1.35 mm at a focus depth of 25 mm for the three fractional signal bandwidths of interest (i.e., 30%, 50% and 70%) considered in the optimization process. The undesired side lobes are successfully suppressed especially when, as a consequence of the multiline strategy, non-coincident steering angles are used in transmission and reception. Moreover, thanks to the firing scheme adopted, a high-volume rate of 63 volumes per second may be achieved at the focus depth. The volume rate decreases to 32 volumes per second at twice the focal depth. Phantom image simulations show that the proposed method maintains a satisfactory and almost uniform image quality in terms of resolution and contrast for all the signal bandwidths of interest.

Energy efficient discontinuous reception strategy in LTE and beyond using an adaptive packet queuing technique

The next generation of mobile communication systems is being developed for high-bandwidth mobile networks to accommodate applications with high data rates and low delay requirements such as voice over internet protocol, video streaming, cyber-physical systems and gaming. These applications consume a considerable amount of energy and hence drain the user equipment (UE) battery quickly. Long-term evolution (LTE)/LTE-advanced has adopted a discontinuous reception (DRX) mechanism to improve the energy efficiency of the UE. DRX allows UEs to monitor the physical downlink control channel in a discontinuous manner when there is no downlink traffic to reduce energy consumption. However, DRX results in higher latency due to its sleep cycle. In this study, the authors present a new scheme that improves energy efficiency in UE while maintaining an average packet delay around a permissible delay threshold. Numerical analysis and system simulation show that this scheme can achieve a significant power saving.

SERIAL transmit – parallel receive (STxPRx) MR imaging produces acceptable proton image uniformity without compromising field of view or SAR guidelines for human neuroimaging at 9.4 Tesla

PurposeNon-uniform B1+ excitation and high specific absorption rates (SAR) compromise proton MR imaging of human brain at 9.4 T (400.5 MHz). By combining a transmit/receive surface coil array using serial transmission of individual coils with a total generalized variation reconstruction of images from all coils, acceptable quality human brain imaging is demonstrated. MethodsB0 is shimmed using sodium MR imaging (105.4 MHz) with a birdcage coil. Proton MR imaging is performed with an excitation/receive array of surface coils. The modified FLASH pulse sequence transmits serially across each coil within the array thereby distributing SAR in time and space. All coils operate in receive mode. Although the excitation profile of each transmit coil is non-uniform, the sensitivity profile estimated from the non-transmit receive coils provides an acceptable sensitivity correction. Signals from all coils are combined in a total generalized variation (TGV) reconstruction to provide a full field of view image at maximum signal to noise (SNR) performance. ResultsHigh-resolution images across the human head are demonstrated with acceptable uniformity and SNR. ConclusionProton MR imaging of the human brain is possible with acceptable uniformity at low SAR at 9.4 Tesla using this serial excitation and parallel reception strategy with TGV reconstruction.

Reception and detection of a wide‐band OFDM signal in a Doppler spreading channel

This study focuses on the reception strategy and the detection method of a wideband orthogonal frequency-division multiplexing (OFDM) signal, which is passing through a Doppler channel. Most prior works regarded the Doppler effect as a reason of interchannel interference due to its destruction of the subcarrier orthogonality. Distinguishing from those works, the authors point out that the wideband OFDM signal is still an OFDM signal with subcarrier orthogonality after passing the channel with single Doppler scaling factor. Thus, the received OFDM signal passing the Doppler spreading channel is a linear superposition of a set of transmitted OFDM signals associated with different parameters. To make full use of the diversity gain offered by the superposition, the authors propose a strategy of diversity reception and a belief propagation detection method for the received wideband OFDM signal. The simulation results show that the proposed strategy improves the performance obviously with increase of the diversity order in a Doppler spreading channel. It offers different options for system demands. Furthermore, the proposed detection method can offer an acceptable performance even it combined with the conventional sampling process. It makes the conventional structure replacing the common resampling structure possible in a wideband OFDM system.

ACOLHIMENTO NA PERSPECTIVA DO PROGRAMA DE MELHORIA DO ACESSO E DA QUALIDADE DA ATENÇÃO BÁSICA

Objetivo: Objetivou-se analisar a estratégia do acolhimento na Atenção Básica no município de Campina Grande, Paraíba, a partir da avaliação externa do primeiro ciclo do Programa de Melhoria do Acesso e da Qualidade da Atenção Básica. Material e Métodos: Trata-se de estudo descritivo, exploratório, quantitativo, realizado entre maio e outubro de 2012. O grupo amostral foi composto por profissionais de saúde de nível superior, vinculados a 92 equipes de Saúde da Família, sendo um profissional de cada equipe. Utilizou-se para coleta de dados um formulário, denominado de Módulo II, preenchido pelo pesquisador. Os dados obtidos foram duplamente digitados e submetidos à análise estatística descritiva no SPSS 17.0. Resultados: A partir dos dados encontrados, constatou-se que 51,7% das Unidades Básicas de Saúde afirmaram realizar o acolhimento, e 46,1% das equipes de Saúde da Família relataram executar o acolhimento durante os cinco dias da semana. No entanto, somente 13,5% das equipes de Saúde da Família referiram a existência de protocolos com definição de diretrizes terapêuticas para acolhimento à demanda espontânea/urgência. 48,3% das equipes de Saúde da Família declararam realizar avaliação de risco e vulnerabilidade no acolhimento dos usuários, porém apenas 22,5% dos profissionais relataram terem sido capacitados para desempenharem essa ação. Conclusão: Conclui-se que a estratégia do acolhimento vem acontecendo no município em estudo de forma pontual, apoiada ainda na perspectiva médico/hegemônica. 
 
 DESCRITORES:
 Avaliação em Saúde. Atenção Primária à Saúde. Estratégia Saúde da Família.

Performance Evaluation with Improved Receiver Design for Asynchronous Coordinated Multipoint Transmissions

Joint transmission is one of the major transmission schemes in Coordinated multipoint (CoMP) transmission/reception systems for Long term evolutionadvanced (LTE-A). Due to different distances between User equipments (UE) and Base stations (BS), signals are not able to arrive at the receiver with perfect synchronization, which implies that the reception at UE is asynchronous. This paper presents an evaluation on asynchronous UE reception in multi-cell downlink joint transmission systems using our LTE-based CoMP simulator. Then, due to asynchronous reception, we propose an improved reception strategy to mitigate the interference which compensate for Rx timing difference on Joint transmission (JT) CoMP systems. Simulation results show that the per-subband global precoding scheme widely used in the CoMP system is considerably sensitive to asynchronous reception since the performance is dominated by the subcarrier used for precoding vector calculation. It is verified that our proposed solution is able to achieve significant improvements under asynchronous reception.

Collaborative reception technique in wireless sensor networks using adaptive antennas

This work describes a new collaborative reception strategy designed to improve the performance and transmission capacity of the nodes of a wireless sensor network. The technique involves the use of a linear array of adaptive antennas, consisting of a set of sensors that operate in a collaborative manner as an adaptive spatial processor. It can be characterized as a single-input multiple-output (SIMO) system and exploits the spatial diversity of the sensors, which significantly improves performance in terms of energy consumption and transmission capacity. The principles of the proposed scheme are presented, together with bit error rate (BER) performance curves. The advantage of the technique is that it enables several sensors to transmit at very low powers, hence reducing energy consumption.

Network Anti-interference Technology Based on Hybrid Optimization Algorithm

According to the cooperation reception strategy and the hybrid optimization, an interference alignment algorithm is proposed. The algorithm can minimize leakage interference and maximize ideal receiption signal power. Firstly, according to the receiver cooperation technology, the pre-coding vectors of transmitter terminal can be estimated by receiver terminal, where these vectors need not be known in advance. In addition, the sum of interference covariance matrix is enough to describe the statistical features of interference alignment problem, which can quickly devise cooperation reception structure. Therefore, based on the bargaining process of cooperation game theory, the optimal full-cooperation mechanism of all the receivers can be selected. The simulation results show that compared with traditionary distributed interference alignment mechanism, our proposed interference alignment mechanism based on cooperation reception strategy and hybrid optimization technology has excellent feasibility under various transmission-power conditions.

Uplink Performance of Time-Reversal MRC in Massive MIMO Systems Subject to Phase Noise

Multiuser multiple-input-multiple-output (MIMO) cellular systems with an excess of base station (BS) antennas (Massive MIMO) offer unprecedented multiplexing gains and radiated energy efficiency. Oscillator phase noise is introduced in the transmitter and receiver radio frequency chains and severely degrades the performance of communication systems. We study the effect of oscillator phase noise in frequency-selective Massive MIMO systems with imperfect channel state information. In particular, we consider two distinct operation modes, namely, when the phase noise processes at the M BS antennas are identical (synchronous operation) and when they are independent (nonsynchronous operation) . We analyze a linear and low-complexity time-reversal maximum-ratio combining reception strategy. For both operation modes, we derive a lower bound on the sum-capacity, and we compare their performance. Based on the derived achievable sum-rates, we show that with the proposed receive processing, an O(√M) array gain is achievable. Due to the phase noise drift, the estimated effective channel becomes progressively outdated. Therefore, phase noise effectively limits the length of the interval used for data transmission and the number of scheduled users. The derived achievable rates provide insights into the optimum choice of the data interval length and the number of scheduled users.

하향 링크 셀룰러 시스템의 Eigen-Beamforming 전송을 위한 적응적 인접 셀 간섭 완화 방법

MIMO(Multiple-Input Multiple-Output) 시스템에서 EB(Eigen-Beamforming)는 MIMO 채 널의 특이 값 분해(Singular Value Decomposition: SVD)를 통하여 수신기의 유효 신호 대 잡음비(Signal-to-Interference Plus Noise Ratio: SI-NR)를 최대화하는 빔을 형성하는 방법으로써 널리 활용되고 있으나, 인접 셀 간섭 신호의 영향으로 셀 경계에 위치한 단말기의 신호 검출 성능은 급격히 열화되고 전송 효율은 감소하게 된다. 본 논문에서는 EB 전송을 활용하는 경우, 적응적 인접 셀 간섭 완화 방안을 제시하고 그 수신 성능을 평가한다. 특히, EB 전송을 이용하여 기지국예서 전송된 신호를 단말기가 수신할 때, 최대의 유효 신호 대 간섭 잡음비를 얻기 위한 OC(Optimum Combining) 및 MMSE-ISD(Minimum Mean-Squared Error for Intercell Spatial Demultiplexing)를 적응적으로 사용하기 위한 기준을 제시하고 유효 신호 대 간섭 잡음비 및 전송 용량 측면의 수신 성능을 분석한다. 제안하는 적응적 수신 방식은 수신 빔포밍 벡터만을 사용하는 기존의 EB 수신 방식 대비 평균 전송 용량 측면에서 향상된 성능을 보이며, 셀 경계 지역에 단말기가 위치할 경우 최대 2 bps/Hz 성능 개선을 가져온다. EB(Eigen-Beamforming) has widely been applied to MIMO(Multiple-Input Multiple-Output) systems to form beams which maximize the effective signal-to-interference plus noise ratio(SINR) of the receiver using the singular value decomposition(SVD) of the MIMO channel. However, the signal detection performance for the mobile station near the cell boundary is severely degraded and the transmission efficiency decreases due to the influence of the interference signal from the adjacent cells. In this paper, we propose an adaptive interference mitigation method for the EB transmission, and evaluate the reception performance. In particular, a reception strategy which adaptively utilizes optimal combining(OC) and minimum mean-squared error for Intercell spatial demultiplexing(MMSE-lSD) is proposed, and the reception performance is investigated in terms of the effective SINR and system capacity. For the average system capacity, the proposed adaptive reception demonstrates the performance enhancement compared to the conventional EB reception using the receiver beamforming vector, and up to 2 bps/Hz performance gain is achieved for mobile station located at the cell edge.

Joint Design of Tx-Rx Beamformers in MIMO Downlink Channel

We consider a single-cell multiple-input multiple-output (MIMO) downlink channel where linear transmission and reception strategy is employed. The base station (BS) transmitter is equipped with a scheduler using a simple opportunistic beamforming strategy, which associates an intended user for each of the transmitted data streams. For the case when the channel of the scheduled users is available at the BS, we propose a general method for joint design of the transmit and the receive beamformers according to different optimization criteria, including weighted sum rate maximization, weighted sum mean square error minimization, minimum signal-to-interference-plus-noise ratio (SINR) maximization and sum power minimization under a minimum SINR constraint. The proposed method can handle multiple antennas at the BS and at the mobile user with single and/or multiple data streams per scheduled user. The optimization problems encountered in the beamformer design (e.g., covariance rank constraint) are not convex in general. Therefore, the problem of finding the global optimum is intrinsically nontractable. However, by exploiting the uplink-downlink SINR duality, we decompose the original optimization problem as a series of simpler optimization problems which can be efficiently solved by using standard convex optimization tools. Even though each subproblem is optimally solved, there is no guarantee that the global optimum has been found due to the nonconvexity of the problem. However, the simulations show that the algorithms converge fast to a solution, which can be a local optimum, but is still efficient.

Hypothesis testing processes in the reception strategy task and hypothesis evaluation task

This study investigated the common characteristics of reasoning in the two types of hypothesis testing tasks that contain similar passive information gathering procedures: reception strategy task and hypothesis evaluation task. Twenty subjects built their own hypothesis but were not allowed to choose instances to test the hypothesis in the reception strategy task, and different 20 subjects in the hypothesis evaluation task only evaluated a hypothesis generated by another person. In addition, subjects were asked to mark instances that they thought suitable to test the hypothesis on each trial. Results showed that subjects chose negative (-H) tests in the middle or later stage of the task. Otherwise, they chose confirmative tests throughout the task. Two possible interpretations of the results were offered that (a) experiencing the false negative (-H +T) made subjects to realize the usefulness of negative testing, and (b) there was a phased shift of the selection tendency between the earlier phase of extracting a possible hypothesis to the later phase of refining it.

Performance analysis of a pre-FFT equalizer design for DVB-T

Conventional OFDM systems employ a guard interval to combat delay spread distortion of the transmitted data. This reduces the efficiency of the OFDM transmission. A combined OFDM-equalization reception strategy is presented in this paper. This strategy employs an adaptive equalizer to combat delay spread distortion instead of a guard interval. This facilitates the use of very short guard intervals and thus the transmission efficiency of the OFDM modulation scheme is improved. This paper presents the combined OFDM-equalization receiver and the pre-FFT equalizer designs. The efficiency of both the conventional OFDM and combined OFDM-equalization strategies is considered and it is demonstrated that combined OFDM-equalization offers a significant improvement in transmission efficiency. The transmission of OFDM signals in single frequency networks is considered and it is shown that the combined OFDM-equalization technique is particularly effective for such applications, offering an improvement in bandwidth efficiency of 14% under severe delay spread conditions. The limitations of the combined OFDM-equalization strategy to operate effectively under both additive noise and time variant conditions are considered. The performance is simulated and the sensitivity to this impairment analyzed.

Learning and Reception Strategy Use and the Cloze Procedure

Cet article traite des strategies d'apprentissage et de reception mises en oeuvre lors d'un test lacunaire rationnel, par deux groupes d'etudiants de francais en premiere annee universitaire. Les donnees receuillies a l'aide d'autoreportages du deroulement de leurs pensees ont fait l'objet d'un examen permettant la creation de listes de strategies. A partir des categories ainsi etablies, les strategies ont une analyse de l'effet, de la frequence, de la qualite et du groupement des emplois strategiques

Language acquisition as concept formation; an experimental approach

Abstract.— A concept formation task which in important respects was meant to simulate a natural language acquisition situation was constructed. The experimental focus was on the establishment of the semantic relation between names and their objects. The task contained both relevant and irrelevant stimulus and response items, and different types of informative feedback were given. The results showed that a self‐controlled selection strategy was more efficient than a fixed reception strategy. However, the superiority of the selection strategy was found to depend on the level of task difficulty. With an easier task, no difference between the two strategies was observed. Ambiguous feedback turned out to be less effective than unambiguous feedback. The findings suggest that word learning takes place as a concept formation process.