Market interactions and competition between public and private oyster production and supplies from other states

Oyster production in Virginia has declined dramatically in the past ten years, causing Virginia oyster processors to rely increasingly on oyster supplies from other regions. In response to the industry problems, the Virginia Marine Resources Commission (VMRC) developed and began implementing an Oyster Fishery Management Plan (OFMP) in 1985. Primarily, the plan seeks to increase Virginia oyster production from both public and leased grounds. A large increase in production could significantly affect the oyster market. There is thus a need to understand the Virginia oyster market, which derives raw material supplies primarily from public and leased-grounds production and from other states. Although the level of competition among the three sources is uncertain, it is thought to be substantial and quite important for the success of the OFMP. This study assesses the level of competition and associated sector interaction. A simultaneous equation system is specified and estimated by Full-Information-Maximum-Likelihood procedure. Estimates and a market simulation model are used to assess the impact of the OFMP on market behavior. Analyses indicate that the market for the public ground fishery consists of an elastic demand and an inelastic supply, but the market for private oyster cultivation consists of an inelastic demand and an elastic supply. The market interaction between the eastern oyster and Pacific oyster is weak. Oysters from leased grounds compete with supplies from other regions and with Pacific oysters. Market simulations indicate that the OFMP will increase total revenue for both public and private producers, suggesting that (1) the seasonal closure on commercial oyster fishery may be extended as stock size recovers, (2) increasing private production may reduce oyster supplies from other states, and (3) from the market interaction point of view, the Pacific oyster may be an alternative for private oyster planters

Mobile Augmented-Reality Artifact Creation as a Component of Mobile Computer-Supported Collaborative Learning

This exploratory study examined the effectiveness of smartphone-based, AR artifact creation and other mobile collaborative learning activities in reinforcing the technological pedagogical content knowledge (TPACK) of pre-service teachers. Adopting a mixed-method research design, the study indicated that mobile AR artifact creation with peer discussion tended to better promote the componential competencies of technological pedagogical knowledge (TPK) and the integrative development of technological pedagogical content knowledge (TPACK), whereas mobile media artifact viewing with peer discussion seemed to better support the content knowledge (CK) development

Internet of Things (IoT) Payload in IRIS CubeSat

IRIS-A is one of CubeSats in IRIS project which is designed, and still developing by NCKU, Taiwan. The mission objective of it is to demonstrate Internet of Things (IoT) communication technology in space. Techniques are developed to compensate for the significant attenuation and Doppler shift in the mission so that ground measurements can be uplinked, stored, and forwarded. To achieve this, there would need the following devices to cooperate in IoT payload, including the LoRa receiver, a reference clockboard, a chip-scale atomic clock (CSAC) and a GPS receiver (GPSR)

Flight Software Implementation and Verification on IRIS CubeSat

Flight software (FSW) is essential in the operation of a satellite program. It is important to verify the functionality and performance of the FSW on ground before being deployed in space. We discusses the implementation and verification of the FSW of the Intelligent Remote-Sensing and Internet Satellite (IRIS) CubeSats

Probing highly collimated photon-jets with deep learning

Many extensions of the standard model (SM) predict the existence of axion-like particles and/or dark Higgs in the sub-GeV scale. Two new sub-GeV particles, a scalar and a pseudoscalar, produced through the Higgs boson exotic decays, are investigated. The decay signatures of these two new particles with highly collimated photons in the final states are discriminated from the ones of SM backgrounds using the Convolutional Neural Networks and Boosted Decision Trees techniques. The sensitivities of searching for such new physics signatures at the Large Hadron Collider are obtained

Role of the Brans-Dicke scalar in the holographic description of dark energy

We study cosmological application of the holographic energy density in the Brans-Dicke theory. Considering the holographic energy density as a dynamical cosmological constant, it is more natural to study it in the Brans-Dicke theory than in general relativity. Solving the Friedmann and Brans-Dicke field equations numerically, we clarify the role of Brans-Dicke field during evolution of the universe. When the Hubble horizon is taken as the IR cutoff, the equation of state (w_{\Lmd}) for the holographic energy density is determined to be 5/3 when the Brans-Dicke parameter \omg goes infinity. This means that the Brans-Dicke field plays a crucial role in determining the equation of state. For the particle horizon IR cutoff, the Brans-Dicke scalar mediates a transition from w_{\Lmd} = -1/3 (past) to w_{\Lmd} = 1/3 (future). If a dust matter is present, it determines future equation of state. In the case of future event horizon cutoff, the role of the Brans-Dicke scalar and dust matter are turned out to be trivial, whereas the holographic energy density plays an important role as a dark energy candidate with w_{\Lmd} =-1.Comment: 10pages, 3figures, version to appear in PL

Calcium Isotope Evolution During Differentiation of Vesta and Calcium Isotopic Heterogeneities in the Inner Solar System

We employed MC-ICP-MS to measure the mass-dependent Ca isotope compositions of Vesta-related meteorites. Eucrites and diogenites show distinct Ca isotope compositions, which is caused by crystallization of isotopically heavy orthopyroxene. The Ca isotope data support a model where the two lithologies are linked, where the diogenites, mainly composed of orthopyroxene crystallized from an eucritic melt. As normal eucrites are the main Ca reservoir on Vesta, their δ44/40Ca values (per mil 44Ca/40Ca ratios relative to NIST 915a) best represents that of bulk silicate Vesta (0.83 ± 0.04‰). This value is different from those of bulk Earth (0.94 ± 0.05‰) and Mars (1.04 ± 0.07‰), suggesting that there exists notable Ca isotope heterogeneity between inner solar system bodies. The δ44/40Ca difference between chondrules and these planets does not support the pebble accretion model as the main mechanism for planetary growth

Sourced Friedmann equations with holographic energy density

We reexamine cosmological applications of the holographic energy density in the framework of sourced Friedmann equations. This framework is suitable because it can accommodate a macroscopic interaction between holographic and ordinary matter naturally. In the case that the holographic energy density decays into dust matter, we propose a microscopic mechanism to generate an accelerating phase. Actually, the cosmic anti-friction arisen from the decay process induces acceleration. For examples, we introduce two IR cutoffs of Hubble horizon and future event horizon to test this framework. As a result, it is shown that the equations of state for the holographic energy density are determined to be the same negative constants as those for the dust matter.Comment: 11 pages, final version to appear in PL

Equation of state for an interacting holographic dark energy model

We investigate a model of the interacting holographic dark energy with cold dark matter (CDM). If the holographic energy density decays into CDM, we find two types of the effective equation of state. In this case we have to use the effective equations of state ($\omega^{\rm eff}_{\rm \Lambda}$) instead of the equation of state ($\omega_{\rm \Lambda})$. For a fixed ratio of two energy densities, their effective equations of state are given by the same negative constant. Actually, the cosmic anti-friction arisen from the vacuum decay process may induce the acceleration with $\omega^{\rm eff}_{\rm \Lambda}<-1/3$. For a variable ratio, their effective equations of state are slightly different, but they approach the same negative constant in the far future. Consequently, we show that such an interacting holographic energy model cannot accommodate a transition from the dark energy with $\omega^{\rm eff}_{\rm \Lambda}\ge-1$ to the phantom regime with $\omega^{\rm eff}_{\rm \Lambda}<-1$.Comment: 11 pages, 2 eps figures, final version to appear in PL