This study presents a non-preemptive priority queue model to approximate the cell delay of a multi-channel slotted ring network with a single tunable transmitter and ®xed receiver, and one queue for storing cells for each channel at each node. To analyze network performance, this network is translated to the proposed non-preemptive priority queue model. With this model, the analytical cell-dela...

In this paper, a new design technique for enhancing bandwidth that improves the performance of a conventional microstrip patch antenna is proposed. This paper presents a novel wideband probe fed inverted slotted microstrip patch antenna. The design adopts contemporary techniques; coaxial probe feeding, inverted patch structure and slotted patch. The composite effect of integrating these techniq...

Analytic results and conclusion: The throughput of a slotted CSMA is well known to be better than that of unslotted case. C, is always worse than C , because the previous ICMA protocol' is similar to the unslotted CSMA as the ratio of b/a becomes smaller. Both C, and C, of the ICMA scheme will be inferior by 0.368 to the slotted ALOHA, when b / a becomes larger than 6 for C, and 8 for C,, as sh...

We propose a p-persistent protocol for slowfrequency-hopped slotted random access networks, assuming that all the users know the number of backlog users in a slot. The proposed protocol delays new packet transmission until the number of users with a packet to be retransmitted decreases to the threshold or less. Performance of the proposed protocol is evaluated with a two-dimensional Markov chai...

Economists have long been fascinated by the sources of variations in the stock market. By the early 1970’s a consensus had emerged among …nancial economists suggesting that stock prices could be well approximated by a random walk model and that changes in stock returns were basically unpredictable. Fama (1970) provides an early, de…nitive statement of this position. Historically, the ‘random wa...

U.S. stock portfolios sorted on size, momentum, transaction costs, M/B, I/A and ROA ratios, and industry classification show considerable levels and variation of return predictability, inconsistent with asset pricing models. This means that a predictable risk premium is not equal to compensation for systematic risk as implied by asset pricing theory (Kirby 1998). We show that introducing market...

The study empirically investigates the relationship between the value anomaly and firms’ investment and financing environment. The evidence supports the relevance of investment irreversibility and the value anomaly as suggested in Zhang (2005). The higher the investment irreversibility gap between value and growth firms, the higher the value premium. While the Fama and French three factor model...

This paper establishes an econometric framework to construct a systematic risk factor from textual data, by linking a beta pricing model with a language model based on machine learning techniques. In this framework, the distributions of stock returns and words in associated documents are determined by a common underlying systematic risk factor (text-implied risk). The exposure to the text-impli...

Recently, contention resolution diversity slotted ALOHA (CRDSA) has been introduced as a simple but effective improvement to slotted ALOHA. It relies on MAC burst repetitions and on interference cancellation to increase the normalized throughput of a classic slotted ALOHA access scheme. CRDSA allows achieving a larger throughput than slotted ALOHA, at the price of an increased average transmitt...

Slotted Waveguide Antenna Stiffened Structure (SWASS) is a type of conformal load-bearing antenna where top-hat cross-section stiffeners on skins, or blade stiffeners in sandwich panels, serve the dual purpose of acting both as structural stiffeners and as waveguides. Cutting slots through the outer skin and into these waveguide stiffeners creates slotted waveguide antenna arrays. Two of the ke...