5,818 research outputs found
Managing the Gulf of Papua Prawn Fishery: Sustainability, Maximum Returns and Cooperation between Commercial Fishing and Indigenous Fishing Communities
In many fisheries around the world, harvesting capacity is excessive and fish stocks are under threat. The Gulf of Papua prawn fishery (GPPF) presents a different set of management challenges. Limited property rights and fishing capacity, along with tension between a commercial fleet and indigenous fishing communities over access, have resulted in a relatively underdeveloped resource, conflict and considerable losses in economic returns. This article details the results of a joint project between the National Fisheries Authority (NFA) in Papua New Guinea and supporting Australian institutions on the management of the GPPF. The analysis indicates a catch target that maximises sustainable returns at biomass levels larger than biomass at maximum sustainable yield, thus protecting the resource, and a simple plan to share access to the inshore fishery. Both strategies are being implemented by the NFA. Together, they present one of the few very good examples of how to 'get things right' in the use and management of a fisheries resource, providing 'win-win' outcomes for Papua New Guinea
Reducing Message Collisions in Sensing-based Semi-Persistent Scheduling (SPS) by Using Reselection Lookaheads in Cellular V2X
In the C-V2X sidelink Mode 4 communication, the sensing-based semi-persistent
scheduling (SPS) implements a message collision avoidance algorithm to cope
with the undesirable effects of wireless channel congestion. Still, the current
standard mechanism produces high number of packet collisions, which may hinder
the high-reliability communications required in future C-V2X applications such
as autonomous driving. In this paper, we show that by drastically reducing the
uncertainties in the choice of the resource to use for SPS, we can
significantly reduce the message collisions in the C-V2X sidelink Mode 4.
Specifically, we propose the use of the "lookahead," which contains the next
starting resource location in the time-frequency plane. By exchanging the
lookahead information piggybacked on the periodic safety message, vehicular
user equipments (UEs) can eliminate most message collisions arising from the
ignorance of other UEs' internal decisions. Although the proposed scheme would
require the inclusion of the lookahead in the control part of the packet, the
benefit may outweigh the bandwidth cost, considering the stringent reliability
requirement in future C-V2X applications.Comment: Submitted to MDPI Sensor
Housing Search in the Age of Big Data: Smarter Cities or the Same Old Blind Spots?
Housing scholars stress the importance of the information environment in shaping housing search behavior and outcomes. Rental listings have increasingly moved online over the past two decades and, in turn, online platforms like Craigslist are now central to the search process. Do these technology platforms serve as information equalizers or do they reflect traditional information inequalities that correlate with neighborhood sociodemographics? We synthesize and extend analyses of millions of US Craigslist rental listings and find they supply significantly different volumes, quality, and types of information in different communities. Technology platforms have the potential to broaden, diversify, and equalize housing search information, but they rely on landlord behavior and, in turn, likely will not reach this potential without a significant redesign or policy intervention. Smart cities advocates hoping to build better cities through technology must critically interrogate technology platforms and big data for systematic biases
Small-scale LNG Market Optimization – Intelligent Distribution Network
Intelligent Systems, thanks to their effectiveness and robustness, find many applications in various industries. One of such applications is optimization of distribution network of small-scale LNG market, which was highly dynamic throughout last years. LNG (Liquified Natural Gas) is a fuel produced from natural gas, but its volume is approx. 600 times smaller than in the gas (natural) state, which makes it more economically effective to transport and store. Distribution network consists of several pickup points (varying in LNG specification) and a number of destination points (varying in tanks capacities). From economic point of view, optimization of LNG truck tanks paths is an important factor in whole market development. The optimization process involves selecting a pickup point and a sequence of destination points with amount of LNG unloaded in each of them. Solution proposed in this paper is based on graph theory and advanced machine learning methods, such as reinforcement learning, recurrent neural networks and online learning. Optimization of distribution network translates directly into a number of economic benefits: reduction of LNG transport cost, shortening the delivery time, reduction of distribution costs and increase in the effectiveness of tank truck usage.
This work is licensed under a Creative Commons Attribution-NonCommercial 4.0 International License.</p
Long-term and blow-up behaviors of exponential moments in multi-dimensional affine diffusions
This paper considers multi-dimensional affine processes with continuous
sample paths. By analyzing the Riccati system, which is associated with affine
processes via the transform formula, we fully characterize the regions of
exponents in which exponential moments of a given process do not explode at any
time or explode at a given time. In these two cases, we also compute the
long-term growth rate and the explosion rate for exponential moments. These
results provide a handle to study implied volatility asymptotics in models
where returns of stock prices are described by affine processes whose
exponential moments do not have an explicit formula.Comment: 36 pages, 5 figure
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