Estimation of short-term centers of activity from an array of omnidirectional hydrophones and its use in studying animal movements

2002 ◽  
Vol 59 (1) ◽  
pp. 23-32 ◽  
Author(s):  
Colin A Simpfendorfer ◽  
Michelle R Heupel ◽  
Robert E Hueter

A method for studying animal movements based on data from independent data-logging acoustic receivers is described. The method takes presence or absence data from multiple receivers arranged in an array and converts them to position estimates based on weighted means of the number of signal receptions at each receiver during a specified time period. The method is equivalent to a short-term center of activity rather than a precise estimate of location at a single time. The utility of the method was assessed using data from a study of neonate blacktip sharks (Carcharhinus limbatus). Periods between 5 and 60 min were tested to find the most appropriate interval for estimating positions. The results from the method agreed closely with a simulated shark track and data from actively tracked sharks. The median distances between successive locations from the mean-position algorithm were between 28% and 42% of those from active tracking because of the center-of-activity nature of the method. The results presented demonstrate that the technique provides a useful method for investigating long-term movement patterns, space utilization patterns over broader areas, and home range.

2021 ◽  
Vol 13 (8) ◽  
pp. 4316
Author(s):  
Shingo Yoshida ◽  
Hironori Yagi

The coronavirus disease 2019 (Covid-19) pandemic has forced global food systems to face unprecedented uncertain shocks even in terms of human health. Urban agriculture is expected to be more resilient because of its short supply chain for urban people and diversified farming activities. However, the short-and long-term effects of the Covid-19 pandemic on urban farms remain unclear. This study aims to reveal the conditions for farm resilience to the Covid-19 pandemic in 2020 and the relationship between short-term farm resilience and long-term farm development using data from a survey of 74 farms located in Tokyo. The results are as follows. First, more than half of the sample farms increased their farm sales during this period. This resilience can be called the “persistence” approach. Second, short-term farm resilience and other sustainable farm activities contributed to improving farmers’ intentions for long-term farm development and farmland preservation. Third, the most important resilience attributes were the direct marketing, entrepreneurship, and social networks of farmers. We discussed the necessity of building farmers’ transformative capabilities for a more resilient urban farming system. These results imply that support to enhance the short-term resilience of urban farms is worth more than the short-term profit of the farms.


2010 ◽  
Vol 13 (06) ◽  
pp. 931-957 ◽  
Author(s):  
MICHAEL J. KLASS ◽  
KRZYSZTOF NOWICKI

Consider any discrete time sequence of investment fortunes Fn which has a finite long-run growth rate [Formula: see text] when subject to the present value capital drawdown constraint Fne-rn ≥ λ* max 0≤k≤nFke-rk, where 0 ≤ λ* < 1, in the presence of a riskless asset affording a return of er dollars per time period per dollar invested. We show that money can be withdrawn for consumption from the invested capital without either reducing the long-run growth rate of such capital or violating the drawdown constraint for our capital sequence, while simultaneously increasing the amount of capital withdrawn for consumption at the identical long-term rate of V(r, λ*). We extend this result to an exponentially increasing number of consumption categories and discuss how additional yearly contributions can temporarily augment the total capital under management. In addition, we assess the short-term practicality of creating such an endowment/consumption/distribution program.


Author(s):  
Fatimah Mohammad Asiri

The study aimed to identify the influence of the financing structure on the return of the market share in Saudi corporations/companies. The study applied the descriptive-analytical approach, and the study population consisted of some joint-stock companies in the Saudi stock market, where the study sample consisted of (75) companies in five productive sectors where concentration was made on the following sectors: (basic materials, long-term commodities, energy, food production, capital goods). Method of the comprehensive survey was used for all companies. The data was analyzed using the Panel Data method through the STATA program. The study concluded several findings, the most important of which are that short-term debt (liabilities) have a negative impact on the return on the market share, as increasing short debts (liabilities) lead to a decrease in the return on the market share, and that long-term debt (liabilities) have no effect on the return on the market share, and equity has a negative impact on the return on the market share, as the increase in financing through equity leads to a decrease in the return on the market share. The study recommended the necessity of diversification between sources of financing and not limited to debt and long & short-term liabilities only. It also recommended conducting such a study on other sectors or conducting it on the whole market which may result in improving results, and also recommends expanding the time period more than five years, which may lead to improve results.


2005 ◽  
Vol 22 (1) ◽  
pp. 42-47 ◽  
Author(s):  
Thomas Treiman ◽  
John Dwyer ◽  
David Larsen

Abstract Much of the software and many of the algorithms commonly used to simulate forest growth and harvesting activities have been optimized for short-term projections based primarily on larger-sized trees and are focused on even-aged silvicultural systems. Using data on trees 1.5 in. dbh and larger from the Missouri Ozark Forest Ecosystem Project (MOFEP), we have adapted the widely available Landscape Management System (LMS) and Forest Vegetation Simulator (FVS) software to make long-term simulations using even and uneven-aged silvicultural management systems. MOFEP is designed to test the long-term effects of even-aged, uneven-aged, and no harvest treatments on a variety of ecosystem attributes. To simulate the economic outcomes of these three treatments, we have written new LMS algorithms that simulate the effects of uneven-aged harvesting. Our results show that in the Missouri Ozarks even-aged and uneven-aged management silvicultural systems yield long-term (100 years) economic outcomes that are not statistically different. This result reinforces the need for land managers or landowners to consider esthetics, nontraditional forest products, and other nonmarket values in their decision matrix. North. J. Appl. For. 22(1):42– 47.


2019 ◽  
Author(s):  
Eirini Boleti ◽  
Christoph Hueglin ◽  
Stuart K. Grange ◽  
André S. H. Prévôt ◽  
Satoshi Takahama

Abstract. Air quality measures that were implemented in Europe in the 1990s resulted in reductions of ozone precursors concentrations. In this study, the effect of these reductions on ozone is investigated by analyzing surface measurements of ozone for the time period between 2000 and 2015. Using a non-parametric time scale decomposition methodology, the long-term, seasonal and short-term variation of ozone observations were extracted. A clustering algorithm was applied to the different time scale variations, leading to a classification of sites across Europe based on the temporal characteristics of ozone. The clustering based on the long-term variation resulted in a site type classification, while a regional classification was obtained based on the seasonal and short-term variations. Long-term trends of de-seasonalized mean and meteo-adjusted peak ozone concentrations were calculated across large parts of Europe for the time period 2000–2015. A multi-dimensional scheme was used for a detailed trend analysis, based on the identified clusters, which reflect precursor emissions and meteorological influence either on the inter-annual or the short-term time scale. Decreasing mean ozone concentrations at rural sites and increasing or stabilizing at urban sites were observed. At the same time downward trends for peak ozone concentrations were detected for all site types. The effect of hemispheric transport of ozone can be seen either in regions affected by synoptic patterns in the northern Atlantic or at sites located at remote high altitude locations. In addition, a reduction of the amplitude in the seasonal cycle of ozone was observed, and a shift in the occurrence of the seasonal maximum towards earlier time of the year. Finally, a reduced sensitivity of ozone to temperature was identified. It was concluded that long-term trends of mean and peak ozone concentrations are mostly controlled by precursors emissions changes, while seasonal cycle trends and changes in the sensitivity of ozone to temperature are driven by regional climatic conditions.


Author(s):  
C. Shi ◽  
L. Manuel ◽  
M. A. Tognarelli

Slender marine risers used in deepwater applications can experience vortex-induced vibration (VIV). It is becoming increasingly common for field monitoring campaigns to be undertaken wherein data loggers such as strain sensors and/or accelerometers are installed on such risers to aid in VIV-related fatigue damage estimation. Such damage estimation relies on the application of empirical procedures that make use of the collected data. This type of damage estimation can be undertaken for different current profiles encountered. The empirical techniques employed make direct use of the measurements and key components in the analyszes (such as participating riser modes selected for use in damage estimation) are intrinsically dependent on the actual current profiles. Fatigue damage predicted in this manner is in contrast to analytical approaches that rely on simplifying assumptions on both the flow conditions and the response characteristics. Empirical fatigue damage estimates conditional on current profile type can account explicitly even for complex response characteristics, participating riser modes, etc. With significant amounts of data, it is possible to establish “short-term” fatigue damage rate distributions conditional on current type. If the relative frequency of different current types is known from metocean studies, the short-term fatigue distributions can be combined with the current distributions to yield integrated “long-term” fatigue damage rate distributions. Such a study is carried out using data from the Norwegian Deepwater Programme (NDP) model riser subject to several sheared and uniform current profiles and with assumed probabilities for different current conditions. From this study, we seek to demonstrate the effectiveness of empirical techniques utilized in combination with field measurements to predict the long-term fatigue damage and the fatigue failure probability.


1990 ◽  
Vol 21 (2) ◽  
pp. 38-44 ◽  
Author(s):  
Joan Randell ◽  
Lorinda Arella ◽  
Sherry Deren ◽  
Charles Lyles ◽  
Mary Ellen Winfield

This paper describes an intervention designed to enhance the integration of vocational services in an outpatient treatment setting. The position of “vocational integrator” was created and implemented in two clinics to (a) raise the importance of vocational services, (b) develop vocational skills and resources available to staff, and (c) review and implement policies to facilitate vocational programming. The sequence of tasks necessary to develop and implement this position, and issues arising for the integrators and the clinics are described. Results indicated that some short term increases in vocational activities were found, and a longer time period may be needed to assess the long term impact of this type of intervention.


2011 ◽  
Vol 28 (1) ◽  
pp. 115-122 ◽  
Author(s):  
Carlos Lago-Peñas

Coach Mid-Season Replacement and Team Performance in Professional SoccerThe coaching carousel or turnover is an extreme but frequently occurring phenomenon in soccer. Among the reasons for firing a coach, the most common is the existence of a shock-effect: a new coach would be able to motivate the players better and therefore to improve results. Using data from the Spanish Soccer League during the seasons from 1997-1998 to 2006-2007, this paper investigates the relationship between team performance and coach change over time. The empirical analysis shows that the shock effect of a turnover has a positive impact on team performance in the short term. Results reveal no impact of coach turnover in the long term. The favourable short-term impact on team performance of a coach turnover is followed by continued gradual worsening of results. The turnover effect is non-existent when the comparison between the new coach and the old coach is done over 10, 15 or 20 matches before and after termination.


Author(s):  
C. Shi ◽  
L. Manuel ◽  
M. A. Tognarelli

Slender marine risers used in deepwater applications can experience vortex-induced vibration (VIV). It is becoming increasingly common for field monitoring campaigns to be undertaken wherein data loggers such as strain sensors and/or accelerometers are installed on such risers to aid in VIV-related fatigue damage estimation. Such damage estimation relies on the application of empirical procedures that make use of the collected data. This type of damage estimation can be undertaken for different current profiles encountered. The empirical techniques employed make direct use of the measurements and key components in the analyses (such as participating riser modes selected for use in damage estimation) are intrinsically dependent on the actual current profiles. Fatigue damage predicted in this manner is in contrast to analytical approaches that rely on simplifying assumptions on both the flow conditions and the response characteristics. Empirical fatigue damage estimates conditional on current profile type can account explicitly even for complex response characteristics, participating riser modes, etc. With significant amounts of data, it is possible to establish “short-term” fatigue damage rate distributions conditional on current type. If the relative frequency of different current types is known from metocean studies, the short-term fatigue distributions can be combined with the current distributions to yield integrated “long-term” fatigue damage rate distributions. Such a study is carried out using data from the Norwegian Deepwater Programme (NDP) model riser subject to several sheared and uniform current profiles and with assumed probabilities for different current conditions. From this study, we seek to demonstrate the effectiveness of empirical techniques utilized in combination with field measurements to predict long-term fatigue damage and life.


2016 ◽  
Vol 23 (6) ◽  
pp. 1343-1352 ◽  
Author(s):  
Marion Karl ◽  
Gordon Winder ◽  
Alexander Bauer

While the relation between terrorism and tourism has been an important topic for tourism research, the questions whether terrorism affects tourism immediately and how long after a terrorism event tourism recovers are, as yet, not clearly answered. The aim of this article is to better understand the magnitude and temporal scale of the impact of terrorism on tourism. To this end, a research model differentiating between short-term and long-term effects of terrorism on tourism is developed and analyzed for the destination Israel using data on tourists from Germany. The results show both short-term and long-term impacts with a time lag between the terrorist event and the beginning of tourism decline of 1 or up to 6 months. An economic influence on the development of tourist arrivals was not detected, but seasonality plays an important role in the relationship between terrorism and tourism.


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