Import demand under price and exchange-rate uncertainties: The case of U.S. Atlantic salmon imports

This study investigates the impacts of price and exchange rate volatilities on Atlantic salmon imports in the U.S. market. We first derive an extended Rotterdam demand model, revealing how risk factors affect import demand through ‘adjusted’ prices. For example, the theoretical model shows that risk-averse importers add risk premiums as a markup for the cost of risk factors. Moreover, the trade effect of volatility variables depends on own-price elasticities and the degree of substitutability between competing products. Our empirical results reveal that U.S. salmon importers are sensitive to price and exchange rate volatilities; however, these two risk factors have differing impacts on import demand, implying the necessity (or effect) of hedging strategies.publishedVersio

Fabrication and Characterization of Polypyrrole/Gold Bilayer Microactuators for Bio-Mems Applications

The proof of concept for conjugated polymer bilayer microactuators had been demonstrated prior to this dissertation with numerous devices, and their advantages in biomedical applications had been recognized. The next step for this technology was implementation in real systems, which required knowledge of the main performance metrics and limitations. In this dissertation, work focused on measuring these metrics for the first time to facilitate the development of cell-clinics, which are microsystems for cell study and for cell-based sensing. The conjugated polymer used throughout the dissertation was polypyrrole doped with dodecylbenzenesulfonate, PPy(DBS), and the second layer in the bilayer was gold. Device fabrication challenges were first identified and addressed, focusing particularly on methods to produce PPy/Au bilayers that did not suffer from delamination. By electroplating Au onto the electrodes or by wet etching them to increase mechanical interlocking, this problem, which had plagued the field for the last decade, was solved. Another important contributor to lifetime, which is a key actuator metric, is loss of electro-activity with extended cycling. This metric was quantified through measurements of the total exchanged charge of PPy(DBS) with cycles of electromechanical redox. This result impacts how these actuators can be used. Two other key metrics on which this work focused were bending angle, analogous to stroke in a linear actuator, and force. It was necessary to determine bending angle as a function of film thickness experimentally because the traditional bilayer beam models could not account for microfabricated bilayer radius of curvature data. Through experimental testing over a wide range of PPy and Au thicknesses, the relationship between PPy:Au thickness ratio and curvature was mapped out. The experimental results demonstrated the existence of strain gradients within the conjugated polymer films, with the material at the surface having greater actuation strain than that at the gold interface. Finally, accurate force measurements had not been done prior to this dissertation research because of the significant challenges involved in developing a method for measuring force in microactuators. This dissertation described the development of such a methodology and provides data for the blocked force as a function of polypyrrole thickness

Effect of Cr3C2 Content on the Microstructure and Wear Resistance of Fe3Al/Cr3C2 Composites

In this paper, an engine piston ring coating comprising composite material of Fe3Al and Cr3C2 mixed powder was prepared by laser cladding onto carbon structural steel. The microstructure and tribological properties of the cladding materials were investigated through X-ray diffraction (XRD), scanning electron microscopy (SEM), energy dispersive spectroscopy (EDS), transmission electron microscopy (TEM), and wear tests. The influence mechanism of the Cr3C2 content in cladding powder was studied. During the process of wear, the soft Fe3Al/Fe2AlCr matrix is first ground off, and the hard Cr7C3 phase initially supports the abrasive surface before being worn away into hard particles, resulting in abrasive wear. With the increase in Cr3C2 content, the hardness of the cladding layer increases, the proportion of the Cr7C3 phase increases, and the morphology changes from a sparse network to a dense floccule. Of the cladding layers with different Cr3C2 content, the 15 wt.% Cr3C2 cladding layer had the lowest friction coefficient, and the 25 wt.% Cr3C2 cladding layer had the lowest wear rate. The low wear rate of the 25 wt.% Cr3C2 cladding layer can be attributed to the fact that adhesive wear does not easily occur and the fine microstructure of the strengthening phase, which facilitates better separation in the grinding surfaces

Content analysis of systematic reviews on the effectiveness of Traditional Chinese Medicine

AbstractObjectiveTo evaluate evidence for the efficacy of Traditional Chinese Medicine (TCM) in systematic reviews.MethodsChinese (TCMPeriodical Literature Database, Chinese Biological Medicine database, Chinese Medical Current Contents, China Hospital Knowledge Database journal fulltext database, Virtual Machining and Inspection System, and Wanfang) and English (Cochrane Database of Systematic Reviews, PubMed and Embase) databases were searched.ResultsThree thousand, nine hundred and fifty-five articles were initially identified, 606 of which met the inclusion criteria, including 251 in English (83 from the Cochrane Database) and 355 in Chinese. The number of articles published each year increased between 1989 and 2009. Cardiocerebrovascular disease was the most studied target disease. Intervention measures includedTCM preparations (177 articles), acupuncture (133 articles) and combinations of TCM and western medicine (38 articles). Control measures included positive medical (177 articles), basic treatment (100 articles), placebo (219 articles), and blank and mutual (107 articles). All articles included at least one reference; the greatest number was 268. Six of 10 articles with high quality references demonstrated curative effectsagainst target diseasesincludingupper respiratory tract infection, dementia and depression. Interventions that were not recommendedwere tripterygium for rheumatoid arthritis andTCM syndrome differentiation for pediatric nocturia. In 10.4% of the studies, the authors concluded that the intervention had a curative effect. The assessors agreed with the authors' conclusions in 88.32% of cases, but rejected 8.94% (54 articles).Conclusion1) Training in systematic review methods, including topic selection, study design, methods and technology, should be improved. 2) Upper respiratory tract infection, dementia and depression may become the predominant diseases treatedby TCM, and the corresponding interventions could be developed into practical applications. 3) Use of non-recommended interventions should be controlled, and there should be more research on side effects

Distractor-aware Event-based Tracking

Event cameras, or dynamic vision sensors, have recently achieved success from fundamental vision tasks to high-level vision researches. Due to its ability to asynchronously capture light intensity changes, event camera has an inherent advantage to capture moving objects in challenging scenarios including objects under low light, high dynamic range, or fast moving objects. Thus event camera are natural for visual object tracking. However, the current event-based trackers derived from RGB trackers simply modify the input images to event frames and still follow conventional tracking pipeline that mainly focus on object texture for target distinction. As a result, the trackers may not be robust dealing with challenging scenarios such as moving cameras and cluttered foreground. In this paper, we propose a distractor-aware event-based tracker that introduces transformer modules into Siamese network architecture (named DANet). Specifically, our model is mainly composed of a motion-aware network and a target-aware network, which simultaneously exploits both motion cues and object contours from event data, so as to discover motion objects and identify the target object by removing dynamic distractors. Our DANet can be trained in an end-to-end manner without any post-processing and can run at over 80 FPS on a single V100. We conduct comprehensive experiments on two large event tracking datasets to validate the proposed model. We demonstrate that our tracker has superior performance against the state-of-the-art trackers in terms of both accuracy and efficiency

Body dissatisfaction and smartphone addiction: the mediation role of intrusive imagery and fear of negative evaluation

This research aimed to examine the mediating effect of intrusive imagery and fear of negative evaluation on the connection between body dissatisfaction and smartphone addiction. 5,909 participants were included in the research, with 53.8% of the sample being female. The average age of the participants was 19.87 years, and their ages ranged from 18 to 32 years. All individuals who were recruited for the study successfully finished the Satisfaction and Dissatisfaction with Body Parts Scale, the Smartphone Addiction Scale, the Intrusive Imagery Scale, and the Fear of Negative Evaluation Scale. Mediational analysis indicated that, with age, gender and body mass index under control, body dissatisfaction was linked to smartphone addiction via (1) the mediating role of intrusive imagery, (2) the mediating role of fear of negative evaluation, and (3) the serial mediating role of intrusive imagery and fear of negative evaluation. Our study for the first time advanced our understanding that intrusive imagery and fear of negative evaluation could be serial mediators of the relationship between body dissatisfaction and smartphone addiction. However, the cross-sectional design prevented us from establishing causality between these variables, which could be better examined in future longitudinal studies