5,181 research outputs found

    Buyer power in U.K. food retailing: a 'first-pass' test

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    Habtu Weldegebriel, University of Warwick Abstract The potential existence of buyer power in U.K. food retailing has attracted the scrutiny of the U.K.'s anti-trust authorities, culminating in the second of two comprehensive regulatory inquiries in recent years. Such inquiries are authoritative but correspondingly time-consuming and costly. Moreover, detection of buyer power has been dogged by the paucity of reliable evidence of its existence. In this paper, we present a simple theoretical model of oligopsony which delivers quasi-reduced form retailer-producer pricing equations with which the null of perfect competition can be tested using readily available market data. Using a cointegrated vector autoregression, we find empirical results that show the null of perfect competition can be rejected in seven of the nine food products investigated. Though not conclusive on the existence of buyer power, the proposed test offers a means via which the behaviour of the retail-producer price spread is consistent with it. At the very least, it can corroborate the concerns of the anti-trust authorities as to whether buyer power is potentially one source of concern

    Innovative Design of External Airbag System for Improved Automotive Safety

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    © 2024 The Author(s). This is an open access article under the Creative Commons Attribution-Non Commercial-No Derivatives CC BY-NC-ND licence, https://creativecommons.org/licenses/by-nc-nd/4.0/Pedestrians are exceptionally vulnerable in road accidents, and despite the advancements in airbag technology for vehicle occupants, fatal injuries still occur due to contact between pedestrians and vehicle components. To address this issue, an innovative solution is introduced in this research: an external airbag system designed to safeguard pedestrians in cases of brake failure. The proposed system includes four airbag modules strategically positioned within the front bumper of the vehicle. These modules are specifically designed to deploy during a collision, providing protection for the pedestrian's head, legs, and body. Equipped with a highly sensitive sensor, the system triggers the airbag electronic controller unit (ECU) upon collision detection. The external airbag curtains deploy, shielding the pedestrian's head from striking the bonnet, while an additional airbag safeguards the pedestrian's legs from impact with the front bumper. With the introduction of this innovative external airbag system, the main goal is to significantly improve road safety for all individuals and prevent numerous fatalities. The introduction of the innovative external airbag system marks a significant advancement in pedestrian safety within the realm of road accidents. By strategically positioning four airbag modules within the vehicle's front bumper and equipping them with a highly sensitive sensor, this system effectively deploys during collisions to protect pedestrians' heads, legs, and bodies. The deployment of external airbag curtains shields pedestrians' heads from striking the bonnet, while an additional airbag safeguards their legs from impact with the front bumper. Through this research and implementation, the primary objective is to enhance road safety for all individuals and mitigate the occurrence of numerous fatalities resulting from pedestrian-vehicle collisions.Peer reviewe

    Time transfer between the Goddard Optical Research Facility and the U.S. Naval Observatory using 100 picosecond laser pulses

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    A horizontal two-way time comparison link in air between the University of Maryland laser ranging and time transfer equipment at the Goddard Optical Research Facility (GORF) 1.2 m telescope and the Time Services Division of the U.S. Naval Observatory (USNO) was established. Flat mirrors of 25 cm and 30 cm diameter respectively were placed on top of the Washington Cathedral and on a water tower at the Beltsville Agricultural Research Center. Two optical corner reflectors at the USNO reflect the laser pulses back to the GORF. Light pulses of 100 ps duration and an energy of several hundred microjoules are sent at the rate of 10 pulses per second. The detection at the USNO is by means of an RCA C30902E avalanche photodiode and the timing is accomplished by an HP 5370A computing counter and an HP 1000 computer with respect to a 10 pps pulse train from the Master Clock

    FeH Absorption in the Near-Infrared Spectra of Late M and L Dwarfs

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    We present medium-resolution z-, J-, and H-band spectra of four late-type dwarfs with spectral types ranging from M8 to L7.5. In an attempt to determine the origin of numerous weak absorption features throughout their near-infrared spectra, and motivated by the recent tentative identification of the E 4\Pi- A ^4\Pi system of FeH near 1.6 microns in umbral and cool star spectra, we have compared the dwarf spectra to a laboratory FeH emission spectrum. We have identified nearly 100 FeH absorption features in the z-, J-, and H-band spectra of the dwarfs. In particular, we have identified 34 features which dominate the appearance of the H-band spectra of the dwarfs and which appear in the laboratory FeH spectrum. Finally, all of the features are either weaker or absent in the spectrum of the L7.5 dwarf which is consistent with the weakening of the known FeH bandheads in the spectra of the latest L dwarfs.Comment: accepted by Ap

    Market Power in UK Food Retailing: Theory and Evidence from Seven Product Groups

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    Establishing the presence of market power in food chains has become an increasingly pertinent line of enquiry given the trend towards increasing concentration that has been observed in many parts of the world. This paper presents a theoretical model of price transmission in vertically related markets under imperfect competition. The model delivers a quasi-reduced form representation that is empirically tractable using readily available market data to test for the presence of market power. In particular, we show that the hypothesis of perfect competition can be rejected if shocks to the demand and supply function are significant and correctly signed in price transmission equations. Using a cointegrated vector autoregression, we find empirical results that are consistent with downstream market power in six out of seven food products investigated, supporting both the findings of the UK competition authority's recent investigation in to supermarkets and renewed calls for further scrutiny of supermarket behaviour by the UK's Office of Trading.imperfect competition, Cointegrated VARs, UK food industry, Marketing, D4, L81,

    A CIMB Stock Price Prediction Case Study with Feedforward Neural Network and Recurrent Neural Network

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    Artificial Neural Network (ANN) is one of the popular techniques used in stock market price prediction. ANN is able to learn from data pattern and continuously improves the result without prior information about the model. The two popular variants of ANN architecture widely used are Feedforward Neural Network (FFNN) and Recurrent Neural Network (RNN). The literature shows that the performance of these two ANN variants is studied dependent. Hence, this paper aims to compare the performance of FFNN and RNN in predicting the closing price of CIMB stock which is traded on the Kuala Lumpur Stock Exchange (KLSE). This paper describes the design of FFNN and RNN and discusses the performances of both ANNs

    Factors that affected the efficacy of nonsurgical periodontal treatment carried out by postgraduate periodontology students

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    The training of postgraduate students in periodontology has a significant clinical impact. The overall assessment of the efficacy of non-surgical treatment of periodontitis, has value to inform training protocols as well as assess the quality of clinical service delivery. Furthermore, obstacles to successful treatment can be identified. The aim of the study was to determine the effectiveness of non-surgical periodontal treatment, as well as the factors that may determine treatment outcome at the postgraduate clinic in the Periodontology Department at the University of the Western Cape, Tygerberg Dental Hospital, between 2016 and 2018. A cross-sectional record-based study of 100 patients was conducted. Demographic, social, clinical, treatment data were obtained from the hospital files. Periodontal parameters including bleeding index (BI), Pocket Probing depth (PPD), Plaque index (PI), and clinical attachment level (CAL), were recorded at the initial visit (Pre-treatment) and follow-up visits (Post-treatment), and the final treatment outcomes were calculated based on the differences of these parameters’ values between the initial visit and the last follow-up visit. Data were presented as mean and range for continuous variables and as a frequency for categorical variables. Statistical analyses were performed to determine if there was a relationship between the varied factors and treatment outcome with p < 0.05 as statistically significant. The results showed that all 100 patients demonstrated a marked reduction in PPD, PI, BI, and loss of CAL. The overall mean PPD reduction was 0.32 (0.5), the mean reduction in PI and BI were 37.2 (24.08) and 34.61 (22.78), respectively, and the mean clinical attachment gain was 0.42 (0.97) mm. Treatment outcome showed no differencein PPD, PI, BI, and CAL between females, smokers, and patients with systemic conditions compared to males, non smokers, and patients without systemic conditions. On the other hand, patients who underwent more maintenance treatment visits over a period longer than 2 months duration had significantly better outcomes compared to patients who had less than two months of duration of treatment. This study proved the effectiveness of the non-surgical surgical periodontal treatment at the postgraduate periodontal clinic. Treatment duration and frequency of recall visits were the most influential factor impacting the treatment outcome
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