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Diet and feeding behavior data are crucial to a deep understanding of the behavioral response and adaptation of primates to a high-altitude environment. From August 2019 to June 2021, we collected data on the feeding behavior of a high-altitude rhesus macaque Macaca mulattagroup from Yajiang County, Western Sichuan Plateau, which has an altitude of over 3,500 m. The results showed that feeding (33.0 ± 1.8%) and moving (28.3 ± 2.6%) were the dominant behavior of rhesus macaques. Macaques ate 193 food items, comprising 11 food categories from 90 species. Our study found that plant roots (30.9 ± 30.1%) and young leaves (28.0 ± 33.1%) were the main foods eaten by macaques. The preferred foods of rhesus macaques were young leaves, fruits, and seeds, and the consumption of these items was positively correlated with its food availability. When the availability of preferred foods was low, macaques took plant roots, barks, and fallen leaves as fallback foods. In particular, roots were a dominant food item in winter, and this way of feeding became a key survival strategy. Our results suggest that, facing the relative scarcity and strong seasonal fluctuations of food resources in high-altitude habitat, macaques adopt active foraging strategies, relying on a variety of food species and adjusting flexibly their food choices based on food availability, which may help to maximize the energy efficiency of high-altitude macaques.

Research on bilingual language processing, for many years now, have focused on the bilingual advantage. The result of these investigations has shown that the said advantage is not found in all participants and in all task conditions. As a result of this, the bilingual language use and the background of the communities have become points to investigate. The current study aimed to investigate some of these finer nuances of ‘bilingual experience’ and their effect on the control mechanisms. This study juxtaposed two different groups of bilinguals with distinct second languages. In the first case, both the first and the second language of the groups are indigenous languages, of the tribal communities they belong to, namely the Ao and Sangtam from Nagaland in India’s north east. In the second case, the second language is English and the first language is Ao. The groups also have differences in terms of socio-cultural background. Two comprehension studies were carried out: a primed translation recognition and a primed lexical decision task. The aim of the study was to check the role of the non-linguistic prime on the language task. The first experiment also probed the presence/absence of switch cost. Together the two experiments investigated the presence of cognitive control in the area of interference inhibition with two different bilingual groups. The results point to some effect of the cultural cue in the second study but not in the first. The reason for the same probably lies in the socio-cultural background as well as the relative status of the languages.

This paper studies several performance metrics of a wireless-powered de-code-and-forward (DF) relay network with imperfect channel state information (CSI). In particular, based on the time switching (TS) protocol, the energy-constrained relay harvesting energy from a power beacon (PB), and uses that harvested energy to forward the source information to destination. The closed-form expression of the outage probability is firstly derived over Rayleigh fading channels. Then, the asymptotic analysis, throughput as well as the symbol error probability (SEP) are derived based on the expression of the outage probability. Next, both transmission power of the source and the power beacon are optimized through the throughput optimization. Finally, simulations are conducted to corroborate our theoretical analysis, and to reveal the impact of the transmission power of the source and PB as well as the imperfect CSI on the system performance.

This paper studies the outage performance of a cognitive Amplify-and-forward (AF) relay network subject to Rayleigh fading. Under the condition of imperfect Channel state information (CSI) estimations of the links from the secondary system to the Primary user (PU), the closed-form upper and lower bounds of the outage probability are derived through a geometrical analysis method. An asymptotic analysis of the outage probability is also derived in the high Signal-to-noise ratio (SNR) regime to gain additional insights on the system. The simulation results corroborate our theoretical analysis, and the effectiveness of the geometrical analysis method is verified with the conventional approach as a benchmark. The asymptotic results are very tight with the analytical lower bound in the high SNR regime. It also can be observed from the simulation results that the impact of the number of relays as well as the imperfect CSI on the outage probability and the diversity order.

In this letter, an efficient parameter design guideline is proposed for closed-loop synchronization architectures. First, the feasible ranges of loop parameters are directly provided in the z-domain according to the closed-loop stability. Second, depending upon unit step response characteristics of synchronization loops, accurate parameters are ascertained by minimizing the variance of the thermal noise induced phase error conditionally. Compared with available methods, this method not only has the features of better intuition but also does not need repeated trial and adjustment operations. Simulation results are presented to corroborate the effectiveness and feasibility of the proposed design guideline.

AbstractIn this paper, the effective capacity of transmit antenna selection-maximal ratio combining (TAS-MRC) systems is studied. By considering constant power allocation, a closed-form expression for the effective capacity is derived. While for variable power allocation, restricted by the average power, optimal power allocation scheme and associated effective capacity is given. Adaptive modulation is used for both constant and variable power allocation, and the superiority of variable power allocation versus constant power allocation is demonstrated by the computer simulations.

Abstract: The positioning precision of the transmitting Chinese Area Positioning System (CAPS) is reduced due to the non-ideal distribution of the satellite constellation. Positioning and navigation enhancement methods are able to improve the reliability and accuracy of the positioning system, especially for users in special regions and special applications. In this paper, a positioning enhanced scheme based on ultra-wide band (UWB) pseudolite is proposed for CAPS. It is demonstrated that the link budget of UWB pseudolite satisfies the FCC’s emission mask requirements. The localization algorithm of the enhanced CAPS is presented. The simulations indicate that the positioning precision of the proposed enhanced scheme is improved greatly, and the feasibility of the enhanced scheme is thus proved.

Abstract: Impulse radio ultra-wideband (IR-UWB) technique has good performance in the application of high-precision localization since it possesses unique properties such as large instantaneous bandwidth and high time resolution. Making IR-UWB localization technology a growing hot topic in recent research field, therefore, it is necessary for us to give an overview of it in this paper. The TOA estimation, error analysis, NLOS identification and NLOS localization are studied in details based on the ranging methods. Simultaneously the UWB localization applications and practical problems are pointed out. At last, we outline the challenges for further research of IR-UWB localization.