Influence of Various Sources of Error and Community Interactions on Quota Management of Fish Stocks

1987 ◽  
Vol 44 (S2) ◽  
pp. s61-s67 ◽  
Author(s):  
Joseph F. Koonce ◽  
Brian J. Shuter
Keyword(s):  
Control Systems ◽  
Environmental Variability ◽  
Production Method ◽  
Community Interactions ◽  
Fish Stocks ◽  
Surplus Production ◽  
Production Models ◽  
Western Lake ◽  
Wide Range ◽  
Quota Management

We compare the performance of fishery control systems based on population and surplus production models. We show that the population method is superior to a surplus production method over a wide range of observational and structural error conditions. We also show that adaptive fishery control systems have potential to reduce uncertainty surrounding management of fisheries like the walleye (Stizostedion vitreum vitreum) fishery of western Lake Erie where unknown bias and error in harvest statistics combine with environmental variability to contribute substantial uncertainty to the quota derivation process.

Adaptive Probing Strategies for Age-Structured Fish Stocks

1983 ◽  
Vol 40 (5) ◽  
pp. 559-569 ◽  
Author(s):  
D. Ludwig ◽  
R. Hilborn
Keyword(s):  
Management System ◽  
Optimal Size ◽  
Fishing Mortality ◽  
Fish Stocks ◽  
Surplus Production ◽  
Production Models ◽  
Productive Potential ◽  
Adaptive Probing ◽  
Age Structured ◽  
Stock Abundance

This paper examines methods of preventing a stock of fish from being held far below its optimal size. Such sustained overexploitation could arise because the model used to manage the stock poorly represented the stock dynamics, because there are significant errors in the estimates of stock abundance, or because there is insufficient contrast in catch and fishing mortality to generate reliable estimates of the productive potential of the stock. We develop a method to correct for biases due to errors in estimates of abundance and show that this correction does improve estimates of productivity, but not sufficiently to enable a manager to recognize the presence of overexploitation. We demonstrate that the management system must generate significant contrast in catch and effort, and once the contrast is generated the managers can easily find near optimal abundance of the stock. With reasonable levels of contrast even very simple surplus production models will perform well when managing complex age-structured fish stocks.

COMPARISON OF CYBER CRIME AWARENESS AMONG SCIENCE AND SOCIAL SCIENCE PERSPECTIVE TEACHERS

2017 ◽  
Vol 4 (36) ◽  
Author(s):  
Anupam Bansal
Keyword(s):  
Social Science ◽  
Automatic Control ◽  
Control Systems ◽  
Child Pornography ◽  
Cyber Crime ◽  
Computer Data ◽  
Automatic Control Systems ◽  
Living Things ◽  
Wide Range

“Cyber crime” has been used to describe a wide range of offences, including offences against computer data and systems (such as “Hacking”), computer related forgery and fraud (such as “phishing”), content offences (such as disseminating child pornography), and copyright offences (such as the dissemination of pirated content). The word “Cyber Crime” has been derived from the words “Cybernetic” which means the science of communication and automatic control systems in both machines and living things.

scholarly journals UV Nanoimprint Lithography: Geometrical Impact on Filling Properties of Nanoscale Patterns

Nanomaterials ◽  
2021 ◽  
Vol 11 (3) ◽  
pp. 822
Author(s):  
Christine Thanner ◽  
Martin Eibelhuber
Keyword(s):  
Layer Thickness ◽  
Process Parameters ◽  
Nanoimprint Lithography ◽  
Failure Modes ◽  
Production Method ◽  
Efficient Production ◽  
Comprehensive Overview ◽  
Replication Method ◽  
Wide Range ◽  
Pattern Size

Ultraviolet (UV) Nanoimprint Lithography (NIL) is a replication method that is well known for its capability to address a wide range of pattern sizes and shapes. It has proven to be an efficient production method for patterning resist layers with features ranging from a few hundred micrometers and down to the nanometer range. Best results can be achieved if the fundamental behavior of the imprint resist and the pattern filling are considered by the equipment and process parameters. In particular, the material properties and pattern size and shape play a crucial role. For capillary force-driven filling behavior it is important to understand the influencing parameters and respective failure modes in order to optimize the processes for reliable full wafer manufacturing. In this work, the nanoimprint results obtained for different pattern geometries are compared with respect to pattern quality and residual layer thickness: The comprehensive overview of the relevant process parameters is helpful for setting up NIL processes for different nanostructures with minimum layer thickness.

A Robust Method for Parameter Estimation from Catch and Effort Data

1989 ◽  
Vol 46 (1) ◽  
pp. 137-144 ◽  
Author(s):  
D. Ludwig ◽  
C. J. Walters
Keyword(s):  
Parameter Estimation ◽  
Robust Estimation ◽  
Robust Method ◽  
Amount Of Information ◽  
Surplus Production ◽  
Production Models ◽  
Composite Estimation ◽  
Estimation Scheme

The problem of robust estimation of optimal effort levels from surplus production models is considered. A variety of models are used to generate data, for the purpose of testing estimation schemes. The result of an estimation is an estimate of the optimal effort. These efforts are compared using the expected discounted value of a deterministic stock, which corresponds to the model used to generate the data. Such a criterion takes into account not only the loss due to bias in the estimated optimal effort, but also the loss due to the variance of the estimator. Estimation is difficult if there is a lack of informative variation in effort levels or stock sizes. In such cases, the estimation scheme which maximizes the criterion described above sacrifices realism in the representation of the stock-production relationship in order to reduce the variance of the estimate of optimal effort. We present a composite estimation scheme which performs acceptably in all the cases we have examined, and whose performance degrades slowly as the amount of information in the data decreases.

scholarly journals Reference points and management strategies: lessons from quantum mechanics

2006 ◽  
Vol 63 (1) ◽  
pp. 4-11 ◽  
Author(s):  
Jon T. Schnute ◽  
Rowan Haigh
Keyword(s):  
Quantum Mechanics ◽  
Management Strategies ◽  
Practical Importance ◽  
Reference Points ◽  
Surplus Production ◽  
Management Algorithm ◽  
Production Models ◽  
Conceptual Role ◽  
Common Framework ◽  
Mathematical Algorithms

Abstract Fisheries management often relies heavily on precautionary reference points estimated from complex statistical models. An alternative approach uses management strategies defined by mathematical algorithms that calculate controls, like catch quotas, directly from the observed data. We combine these two distinct paradigms into a common framework using arguments from the historical development of quantum mechanics. In fisheries, as in physics, the core of the argument lies in the technical details. We illustrate the process of designing a management algorithm similar to one actually used by the International Whaling Commission. Reference points and surplus production models play a conceptual role in defining management strategies, even if marine populations do not obey such simplistic rules. Physicists have encountered similar problems in formulating quantum theory, where mathematical objects with seemingly unrealistic properties generate results of great practical importance.

The Influence of In-Vehicle Noise on Speech Recognition for Automotive Voice-Activated Control Systems

2002 ◽  
Vol 33 (9) ◽  
pp. 19-23
Author(s):  
By Dave G. Fish
Keyword(s):  
Speech Recognition ◽  
Control Systems ◽  
Convenient Method ◽  
Vehicle Control ◽  
Climate Control ◽  
High Demand ◽  
Vehicle Noise ◽  
Control Functions ◽  
Wide Range ◽  
Vehicle Systems

Voice activation provides a safe and convenient method of controlling vehicle systems such as in-car entertainment, telecommunications and climate control. In the fullness of time it is likely that there will be a high demand across all vehicle classes for such systems for a wide range of vehicle control functions. One of the challenges facing their development and introduction into vehicles is that of the in-vehicle noise environment.

scholarly journals Fisheries Reference Point and Stock Status of Croaker Fishery (Sciaenidae) Exploited from the Bay of Bengal, Bangladesh

2022 ◽  
Vol 10 (1) ◽  
pp. 63
Author(s):  
Partho Protim Barman ◽  
Md. Mostafa Shamsuzzaman ◽  
Petra Schneider ◽  
Mohammad Mojibul Hoque Mozumder ◽  
Qun Liu
Keyword(s):  
Bay Of Bengal ◽  
Maximum Sustainable Yield ◽  
Reference Points ◽  
Production Model ◽  
Fishing Pressure ◽  
Surplus Production ◽  
Stock Status ◽  
Management Measures ◽  
Production Models ◽  
The Monte Carlo Method

This research evaluated fisheries reference points and stock status to assess the sustainability of the croaker fishery (Sciaenidae) from the Bay of Bengal (BoB), Bangladesh. Sixteen years (2001–2016) of catch-effort data were analyzed using two surplus production models (Schaefer and Fox), the Monte Carlo method (CMSY) and the Bayesian state-space Schaefer surplus production model (BSM) method. This research applies a Stock–Production Model Incorporating Covariates (ASPIC) software package to run the Schaefer and Fox model. The maximum sustainable yield (MSY) produced by all models ranged from 33,900 to 35,900 metric tons (mt), which is very close to last year’s catch (33,768 mt in 2016). The estimated B > BMSY and F < FMSY indicated the safe biomass and fishing status. The calculated F/FMSY was 0.89, 0.87, and 0.81, and B/BMSY was 1.05, 1.07, and 1.14 for Fox, Schaefer, and BSM, respectively, indicating the fully exploited status of croaker stock in the BoB, Bangladesh. The representation of the Kobe phase plot suggested that the exploitation of croaker stock started from the yellow (unsustainable) quadrant in 2001 and gradually moved to the green (sustainable) quadrant in 2016 because of the reduction in fishing efforts and safe fishing pressure after 2012. Thus, this research suggests that the current fishing pressure needs to be maintained so that the yearly catch does not exceed the MSY limit of croaker. Additionally, specific management measures should implement to guarantee croaker and other fisheries from the BoB.

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