scholarly journals Simulation of selected management strategies on Canterbury sheep farms

1990 ◽  
pp. 211-215
Author(s):  
J.D. Finlayson ◽  
O.J. Cacho ◽  
A.C. Bywater
Keyword(s):  
Body Weight ◽  
Simulation Model ◽  
Management Strategy ◽  
Management Strategies ◽  
Model Management ◽  
Stocking Rate ◽  
Alternative Management ◽  
Sheep Farm ◽  
Gross Margins ◽  
Selection Of

A simulation model was used to investigate the effects of various combinations of stocking rate, drafting weight and lambing season on a hypothetical dryland farm in Canterbury. A selection of physical results is presented and financial impications of alternative management strategies are briefly discussed. Stocking rate and lambing time had considerable effects on animal performance, with minor effects from drafting weight. Gross margins were considerably affected by stocking rate; the highest return was obtained with conventional lambing at 15 su per ha and drafting lambs at 30 kg empty body weight. Keywords model, management strategy, sheep farm

scholarly journals The evaluation of two management strategies for the Gulf of Alaska walleye pollock fishery under climate change

2009 ◽  
Vol 66 (7) ◽  
pp. 1614-1632 ◽  
Author(s):  
Z. Teresa A’mar ◽  
André E. Punt ◽  
Martin W. Dorn
Keyword(s):  
Climate Change ◽  
Management Strategy ◽  
Management Strategies ◽  
Gulf Of Alaska ◽  
Walleye Pollock ◽  
Reference Level ◽  
Climate Indices ◽  
Management Performance ◽  
Intergovernmental Panel ◽  
Alternative Management

Abstract A’mar, Z. T., Punt, A. E., and Dorn, M. W. 2009. The evaluation of two management strategies for the Gulf of Alaska walleye pollock fishery under climate change. – ICES Journal of Marine Science, 66: 1614–1632. Management strategy evaluation (MSE) is the process of using simulation testing with feedback to examine the robustness of candidate management strategies to error and uncertainty. The structure of the management strategy can be selected to attempt to satisfy desired (but conflicting) management objectives. MSE was used to assess the performance of the current management strategy and an alternative management strategy (the “dynamic B0” strategy) for the fishery for walleye pollock (Theragra chalcogramma) in the Gulf of Alaska (GOA), when age-1 recruitment was driven by climate. The relationships between age-1 abundance and climate indices (and the uncertainties associated with these relationships) were characterized within an age-structured operating model that was fitted to the data for GOA walleye pollock. Projections into the future were based on the fitted relationships and predictions of those indices from the Intergovernmental Panel on Climate Change (IPCC) models, using the current or the alternative management strategy to determine catch limits. Management performance (the ability to leave the stock close to the management reference level and achieve high and stable catches) deteriorated when age-1 recruitment was forced by climate, although stocks were kept near the reference level on average. In addition, the ability to estimate management-related quantities, such as spawning biomass, deteriorated markedly when recruitment was forced by climate. Performance was sensitive to the choice of IPCC dataset and, in particular, estimation and management performance was poorest (outcomes most variable) for the IPCC datasets that led to the greatest variation in recruitment to the fishery. Although basing management on a “dynamic B0” management strategy led to improved management and estimation performance, the magnitude of the improvement was slight.

scholarly journals Optimal Management Strategies for Alfalfa Production Within a Total Farm Plan

1985 ◽  
Vol 17 (2) ◽  
pp. 127-138 ◽  
Author(s):  
David L. Debertin ◽  
Angelos Pagoulatos
Keyword(s):  
Linear Programming ◽  
Management Strategy ◽  
Programming Model ◽  
Management Strategies ◽  
Linear Programming Model ◽  
Optimal Management ◽  
Alternative Management ◽  
Grain Crops ◽  
Net Returns

AbstractThis paper examines the impacts of alternative management strategies for the production of alfalfa within the context of a total farm plan. A linear programming model is used to represent a 600-acre farm which can grow either grain crops or alfalfa. Alfalfa production competes with the grain crops for available land, labor, machinery, and field time over a calendar of tillage, planting, cutting, spraying, and harvesting activities. The profitability of an acre of alfalfa and the contribution of alfalfa to net returns for the farm varies quite widely depending on the particular alfalfa management strategy selected.

Implementation of Wheel-Rail Friction Management Strategy on MRS Railroad

2010 ◽  
Author(s):  
Cristiano Jorge ◽  
Walter Vidon ◽  
Felipe Vidon ◽  
Rob Caldwell
Keyword(s):  
Management Strategy ◽  
Best Practice ◽  
Management Strategies ◽  
Measurement Data ◽  
Business Case ◽  
Operational Reliability ◽  
Friction Modifier ◽  
Monitoring Technologies ◽  
Effective Friction ◽  
Selection Of

For several years, North American Railroads and their Research Institutions’ have been involved in implementing best-practice friction management strategies on heavy haul tracks. During 2006, MRS Railroad visited CP Rail and was impressed with the 100% effective Friction Management strategy that had been developed and implemented in CPR mountain tracks. The strong similarity of CPR’s track and train characteristics to those of MRS Railroad was also noted. By the beginning of 2007, MRS Railroad invited NRC-CSTT to bring this innovative methodology to Brazil and to rapidly develop and implement a customized strategy of 100% effective Gauge-Face lubrication and Top-of-Rail friction management. The utilization of a Brazilian contract service to ensure proper maintenance and filling of the friction management equipment, the gathering of measurement data and analysis of results ensured the success of the project. This paper will discuss the processes (installations, inspections and monitoring), technologies (equipment, devices and tools), results and benefits based on this best-practice methodology applied to the MRS Railroad over two years (2007–2008). The work was divided into five phases: selection of an optimal rail curve grease; selection of test sites and measurement of the baseline case (dry condition); measurement and management of 100% effective Gauge-Face lubrication using rail curve grease; measurement and management of 100% effective friction management using Top-of-Rail friction modifier; and the final economic analysis. This paper will also report the results of the business case analysis, quantifying the actual net savings accrued to MRS as a result of the implementation of Friction Management on test sites, and the projected savings that will occur through the expansion of this strategy to the entire MRS system. In the last 12 years, MRS’ operational reliability has significantly improved through the strategic application of innovation, technology and knowledge. Expanding this strategy to include best-practices friction management will contribute to increased safety and productivity at MRS. Production is projected to increase from over 136 million net tonnes expected in 2010 to 300 million net tonnes by 2018.

Sensitivity Analysis and Selection of Check Index of Signal Intersection Simulation Model Based on VISSIM

2019 ◽  
Vol 2 (5) ◽  
Author(s):  
Mengda Zhang ◽  
Chenjing Zhou ◽  
Tian-tian Zhang ◽  
Yan Han
Keyword(s):  
Sensitivity Analysis ◽  
Simulation Model ◽  
Optimal Process ◽  
Parameter Calibration ◽  
Index Set ◽  
The Core ◽  
Core Module ◽  
Simulation Parameter ◽  
Simulation Parameters ◽  
Selection Of

Selecting check index quantitatively is the core of the calibration of micro traffic simulation parameters at signal intersection. Five indexes in the node (intersection) module of VISSIM were selected as the check index set. Twelve simulation parameters in the core module were selected as the simulation parameters set. Optimal process of parameter calibration was proposed and model of the intersection of Huangcun west street and Xinghua street in Beijing was built in VISSIM to verify it. The sensitivity analysis between each check index and simulation parameter in their own set was conducted respectively. Sensitive parameter sets of different check indices were obtained and compared. The results show that different indexes have different size of set, and average vehicle delay's is maximum, so it's necessary to select index quantitatively. The results can provide references for scientific selection of the check indexes and improve the study efficiency of parameter calibration.

Addressing on-farm management to enhance pasture productivity and persistence

2013 ◽  
pp. 241-244
Author(s):  
W.N. Reynolds
Keyword(s):  
Management Strategies ◽  
Dairy Farm ◽  
Stocking Rate ◽  
Pasture Management ◽  
Pasture Production ◽  
Operating Profit ◽  
The North ◽  
The Cost ◽  
On Farm ◽  
Attention To Detail

Following the 2007/08 drought, we experienced poor pasture production and persistence on our dairy farm in north Waikato, leading to decreased milksolids production and a greater reliance on bought-in feed. It is estimated that the cost of this to our farming operation was about $1300 per hectare per year in lost operating profit. While climate and black beetle were factors, they did not explain everything, and other factors were also involved. In the last 3 years we have changed our management strategies to better withstand dry summers, the catalyst for which was becoming the DairyNZ Pasture Improvement Focus Farm for the north Waikato. The major changes we made were to reduce stocking rate, actively manage pastures in summer to reduce over-grazing, and pay more attention to detail in our pasture renewal programme. To date the result has been a reduced need for pasture renewal, a lift in whole farm performance and increased profitability. Keywords: Focus farm, over-grazing, pasture management, pasture persistence, profitability

ESTIMASI NILAI HERITABILITAS BOBOT IKAN MAS VARIETAS PUNTEN DALAM PROGRAM SELEKSI INDIVIDU

2016 ◽  
Vol 11 (3) ◽  
pp. 217
Author(s):  
Estu Nugroho ◽  
Budi Setyono ◽  
Mochammad Su’eb ◽  
Tri Heru Prihadi
Keyword(s):  
Body Weight ◽  
Selection Response ◽  
Base Population ◽  
Breeding Programs ◽  
Male And Female ◽  
Body Weight Trait ◽  
Population Selection ◽  
Selection For ◽  
Weight Trait ◽  
Selection Of

Program pemuliaan ikan mas varietas Punten dilakukan dengan seleksi individu terhadap karakter bobot ikan. Pembentukan populasi dasar untuk kegiatan seleksi dilakukan dengan memijahkan secara massal induk ikan mas yang terdiri atas 20 induk betina dan 21 induk jantan yang dikoleksi dari daerah Punten, Kepanjen (delapan betina dan enam jantan), Kediri (tujuh betina dan 12 jantan), Sragen (27 betina dan 10 jantan), dan Blitar (15 betina dan 11 jantan). Larva umur 10 hari dipelihara selama empat bulan. Selanjutnya dilakukan penjarangan sebesar 50% dan benih dipelihara selama 14 bulan untuk dilakukan seleksi dengan panduan hasil sampling 250 ekor individu setiap populasi. Seleksi terhadap calon induk dilakukan saat umur 18 bulan pada populasi jantan dan betina secara terpisah dengan memilih berdasarkan 10% bobot ikan yang terbaik. Calon induk yang terseleksi kemudian dipelihara hingga matang gonad, kemudian dipilih sebanyak 150 pasang dan dipijahkan secara massal. Didapatkan respons positif dari hasil seleksi berdasarkan bobot ikan, yaitu 49,89 g atau 3,66% (populasi ikan jantan) dan 168,47 g atau 11,43% (populasi ikan betina). Nilai heritabilitas untuk bobot ikan adalah 0,238 (jantan) dan 0,505 (betina).Punten carp breeding programs were carried out by individual selection for body weight trait. The base population for selection activities were conducted by mass breeding of parent consisted of 20 female and 21 male collected from area Punten, eight female and six male (Kepanjen), seven female and 12 male (Kediri), 27 female and 10 male (Sragen), 15 female and 11 male (Blitar). Larvae 10 days old reared for four moths. Then after spacing out 50% of total harvest, the offspring reared for 14 months for selection activity based on the sampling of 250 individual each population. Selection of broodstock candidates performed since 18 months age on male and female populations separately by selecting based on 10% of fish with best body weight. Candidates selected broodstocks were then maintained until mature. In oder to produce the next generation 150 pairs were sets and held for mass spawning. The results revealed that selection response were positive, 49.89 g (3.66%) for male and 168.47 (11.43%) for female. Heritability for body weight is 0.238 (male) and 0.505 (female).

Wastewater management strategies for the black sea coast of Turkey

1999 ◽  
Vol 39 (8) ◽  
pp. 169-176
Author(s):  
I. Ozturk ◽  
E. Yuksel ◽  
A. Tanik
Keyword(s):  
Black Sea ◽  
Management Strategy ◽  
Population Distribution ◽  
Management Strategies ◽  
The Black Sea ◽  
Wastewater Management ◽  
Black Sea Coast ◽  
The Cost ◽  
Solid Waste Landfills ◽  
Sea Coast

The Black Sea, surrounded by six riparian countries, is under the threat of severe pollution, giving rise to the need of taking precautions to protect it from further deterioration. In this paper, an effort putting forth a wastewater treatment and management strategy is outlined for the Black Sea coast of Turkey, including both the technical and financial aspects. The present situation of the coast in terms of land-based pollution and infrastructure is stated, followed by an applicable management strategy. The strategy developed for the coastal settlements involves various stagewise treatment schemes based on population distribution and densities along the coastline, and on the availability of land in a specified period of thirty years. Similar strategies are proposed for the control of pollution originating from industries, for those carried by rivers joining the sea, and for leachate of solid waste landfills. The cost estimations of various treatment schemes are also given in terms of population equivalents.

Forest management strategies for dealing with fire-related uncertainty when managing two forest seral stages

2011 ◽  
Vol 41 (2) ◽  
pp. 309-320 ◽  
Author(s):  
David W. Savage ◽  
David L. Martell ◽  
B. Mike Wotton
Keyword(s):  
Forest Management ◽  
Simulation Model ◽  
Sustainable Forest Management ◽  
Management Strategies ◽  
Fire Regimes ◽  
Analysis Tool ◽  
Planning Model ◽  
Minimum Area ◽  
Forest Management Planning ◽  
Planning Models

Ecological values are an important aspect of sustainable forest management, but little attention has been paid to maintaining these values when using traditional linear programming (LP) forest management planning models in uncertain planning environments. We embedded an LP planning model that specifies when and how much to harvest in a simulation model of a “managed” flammable forest landscape. The simulation model was used to evaluate two strategies for dealing with fire-related uncertainty when managing mature and old forest areas. The two seral stage areas were constrained in the LP planning model to a minimum of 10% of the total forest area and the strategies were evaluated under four representative fire regimes. We also developed a risk analysis tool that can be used by forest managers that wish to incorporate fire-related uncertainty in their decision-making. We found that use of the LP model would reduce the areas of the mature and old forest to their lower bound and fire would further reduce the seral areas below those levels, particularly when the mean annual burn fraction exceeds 0.45% per annum. Increasing the minimum area required (i.e., the right-hand side of the constraint) would increase the likelihood of satisfying the minimum area requirements.

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