Jury voting without objective probability

© 2015, Springer-Verlag Berlin Heidelberg. Unlike in the standard jury voting experiment, the voting environment in practice has no explicit signal structure. Voters then need to conceptualize the information structure in order to update their beliefs based on “pivotal reasoning”. This paper investigates whether voters can play a strategic voting under a “detail-free” environment. We obtain non-parametric predictions in terms of the differences in voting behaviors under majority and unanimity rule. Our experimental results suggest that voters can still play the strategic voting as in the existing experiments

Is the expressive vocabulary of young Cantonese speakers noun or verb dominated?

The spontaneous utterances produced by 492 Cantonese-speaking children aged 36-60 months in 30-minute toy play contexts were collected. The incidence and percentage of different lexical classes, the ratio of noun and verb types and tokens were calculated. A statistically significant predominance of verb usage was found in the expressive utterances of the children. No similar predominance was found for nouns. Linguistic, cultural and contextual variables possibly underlying these outcomes are explored and discussed.postprin

A Randomized Controlled Trial of the Effectiveness of Brief-CBT for Patients with Symptoms of Posttraumatic Stress Following a Motor Vehicle Crash

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Coupling-fed frequency agile monopole fluid antenna

A coupling-fed reconfigurable monopole fluid antenna is investigated. The proposed geometry separates the ionized fluid from the feed line to prevent leakage. The preliminary results show that the operating frequency of the antenna can be reconfigurable by changing the length of the ionized fluid through an external pump. The peak efficiency is about 75% antenna can

Effective throughput: A unified benchmark for pilot-aided OFDM/SDMA wireless communication systems

In this paper, we study the uplink performance of an orthogonal frequency division multiplexing (OFDM) wireless system where multiple antennas are utilized at the base station (BS). Further, capacity can be greatly enhanced through spatial division multiple access (SDMA), so that several users can transmit packets simultaneously to the BS. The system performance is determined by various transmission techniques, including methods for channel estimation, modulation, as well as channel coding. Conventional parameters such as packet error rate (PER) and bit error rate (BER) are unable to reflect the actual system performance because no consideration is given to the overheads incurred by the transmission techniques. Therefore, we are motivated to propose a novel concept called effective throughput to characterize the capacity available to users by incorporating all these factors. The effective throughput for a user can be viewed as the average number of successfully received data bits in an OFDM symbol after excluding erroneously received packets and the overheads due to channel estimation and coding. It also directly relates to the transmission delay of a user packet. The system effective throughput is the aggregated effective throughput of all users. Simulation results demonstrate that effective throughput can serve as a useful and more meaningful benchmark parameter in optimizing system performance.published_or_final_versio

Effective throughput for coded OFDM/SDMA systems with pilot-assisted channel estimation

This paper investigates the performance of coded orthogonal frequency division multiflexing (OFDM) systems with receiving adaptive array, through which multiple users with single-element transmitting antenna are supported simultaneously by spatial division multiple access (SDMA). We characterize the performance of an OFDM/SDMA systems by effective throughput, which is essentially the average number of data bits in an OFDM symbol after considering the erroneous packet transmissions and modulation scheme by excluding the overhead from coding and pilots for channel estimation. Optimization of system operating parameters can be achieved through the maximization of effective throughput. The focus of this paper is to study the impact of pilot density and the number of users on the performance of coded OFDM/SDMA systems. Through extensive computer simulation, we how that using more pilots always improves bit error rate (BER) performance, but may reduce effective throughput. The optimal number of pilots together with the modulation scheme can he determined by maximizing the effective throughput for given operating signal-to-noise ratio (SNR). It is also shown that the system performance degrades gradually with the increase of users. For a system with a six-element adaptive array, the effective throughput with 5 users is lower than that with 4 users for a certain range of SNR. This indicates that the maximal number of users supportable by the system should consider the effective throughput. © 2003 IEEE.published_or_final_versio

Robust Localization for Mixed LOS/NLOS Environments With Anchor Uncertainties

Localization is particularly challenging when the environment has mixed line-of-sight (LOS) and non-LOS paths and even more challenging if the anchors’ positions are also uncertain. In the situations in which the parameters of the LOS-NLOS propagation error model and the channel states are unknown and uncertainties for the anchors exist, the likelihood function of a localizing node is computationally intractable. In this paper, assuming the knowledge of the prior distributions of the error model parameters and that of the channel states, we formulate the localization problem as the maximization problem of the posterior distribution of the localizing node. Then we apply variational distributions and importance sampling to approximate the true posterior distributions and estimate the target’s location using an asymptotic minimum mean-square-error (MMSE) estimator. Furthermore, we analyze the convergence and complexity of the proposed variational Bayesian localization (VBL) algorithm. Computer simulation results demonstrate that the proposed algorithm can approach the performance of the Bayesian Cramer-Rao bound (BCRB) and outperforms conventional algorithm

Secure Localization and Velocity Estimation in Mobile IoT Networks with Malicious Attacks

IEEE Secure localization and velocity estimation are of great importance in Internet of Things (IoT) applications and are particularly challenging in the presence of malicious attacks. The problem becomes even more challenging in practical scenarios in which attack information is unknown and anchor node location uncertainties occur due to node mobility and falsification of malicious nodes. This challenging problem is investigated in this paper. With reasonable assumptions on the attack model and uncertainties, the secure localization and velocity estimation problem is formulated as an intractable maximum a posterior (MAP) problem. A variational-message-passing (VMP) based algorithm is proposed to approximate the true posterior distribution iteratively and find the closed-form estimates of the location and velocity securely. The identification of malicious nodes is also achieved in the meantime. The convergence of the proposed VMP-based algorithm is also discussed. Numerical simulations are finally conducted and the results show the VMP-based joint localization and velocity estimation algorithm can approach the Bayesian Cramer Rao bound and is superior to other secure algorithms

Characteristics of supercontinuum generation under the influence of a weak continuous-wave trigger

Oral - MF3We numerically study the impacts of introducing a minute continuous-wave trigger on the properties of picosecond supercontinuum generation; namely the bandwidth, temporal coherence and pulse-to-pulse stability. © 2011 IEEE.published_or_final_versionThe 24th Annual Meeting of the IEEE Photonics Society (PHO 2011), Arlington, VA., 9-13 October 2011. In Proceedings of 24th IEEE PHO, 2011, p. 53-5

香港華人多發性硬化症的流行病學研究：問卷調查

OBJECTIVE: To study the epidemiology of multiple sclerosis in Hong Kong Chinese. DESIGN: Cross-sectional questionnaire survey. SETTING: Neurology and paediatric neurology departments in Hong Kong from January through June 1999. PARTICIPANTS: All confirmed multiple sclerosis patients. MAIN OUTCOME MEASURES: Demographic data, investigation results, Kurtzke's Expanded Disability Status Scale during the last follow-up visit, number of relapses between 1997 and 1998, and treatments used/currently in use. RESULTS: Fifty-three Chinese multiple sclerosis patients were identified. The prevalence was thus estimated to be 0.77 per 100,000 population. This low prevalence was also noted in other multiple sclerosis studies from South-East Asia (range, 0.8-4 per 100,000 population). The female to male ratio among the Chinese multiple sclerosis sufferers was 9.6:1, a figure somewhat higher than that reported in the other studies from South-East Asia (range, 3.2-6.6:1). The Chinese multiple sclerosis patients in this study also had a high spinal cord involvement (66%) and a low presence of cerebrospinal fluid oligoclonal banding (40%). These findings were different from those in Caucasian multiple sclerosis patients. CONCLUSION: Multiple sclerosis in Hong Kong Chinese has a low prevalence, a high female to male ratio, and a low cerebrospinal fluid oligoclonal banding presence.published_or_final_versio