scholarly journals CONTROLLING THE PARAMETRIC ROLL OF A CONTAINER SHIP MODEL BY CHANGING THE HEADING ANGLE

2021 ◽  
Vol 13 (3) ◽  
pp. 37-44
Author(s):  
Dumitru Deleanu ◽  
◽  
Constantin Louis Dumitrache ◽  

Parametric roll on ships is an auto-parametric resonance phenomenon whose onset causes a sudden rise in roll oscillations leading to dangerous situations for the ship, the cargo and the crew. In the paper, we have numerically investigated the effect of modifying the heading angle on the roll amplitudes. We followed three strategies. In the first, we allowed the heading angle to decrease with a constant angular acceleration so that the encounter frequency has left the dangerous region of the resonance. However, this option involves changing the course of the ship in the long run, which is of course a shortcoming. In the second strategy, we changed the heading angle up and down around an average value that generates large roll amplitudes, by using different periodic sinusoidal or triangular profiles. The beneficial effect of this action is to keep the course, even if at the cost of a momentary delay. We noticed that both control techniques listed above generally managed to significantly reduce the roll amplitudes if certain thresholds have been exceeded. As a last idea for decreasing the parametric roll amplitudes, we used the combined effect of ship forward speed and heading angle change.

2019 ◽  
Vol 9 (2) ◽  
pp. 35
Author(s):  
Sri Marti Pramudena

This study aims to determine the financial position and financial performance Cooperative Sucofindo Jaya (KOPSUCOFINDO JAYA) from fiscal year 2009-2011 through a comparative analysis / comparisons and ratio analysis. From the research, the authors obtained a picture that results of the financial position and financial performance of KOPSUCOFINDO JAYA as follows: (1) To Horizontal Analysis of the Balance Sheet shows the overall unfavorable developments as the rise of short-term debt experienced a greater percentage increase than the increase in current assets (2) For Horizontal Analysis of the SHU, SHU in 2010 an increase of 125.38% compared to 2009 and in 2011 increased by 282.47% compared to 2009, but this increase was not followed by a reduction in the burden of cost of goods, especially business and this increase was obtained from the contribution percentage increase in other income. (3) For Vertical Analysis of the Balance Sheet shows that in terms of assets, current assets are assets that make up the largest component but also cause considerable investment value embedded in current assets and also showed asset turnover, receivables turnover and working capital is very low under 1 times. (4) For the SHU Vertical analysis shows that income JAYA KOPSUCOFINDO more than 85% absorbed in the Cost of Goods. (5) For liquidity analysis showed that highly liquid KOPSUCOFINDO JAYA obtain an average value above 400%. (6) For solvency analysis shows that the performance is not good / not solvable because the results of the analysis LITA average of above 95%, Total Debt to Equity Ratio in the top 2.000%, and Net Worth Debt Ratio to average below 4%. (7) For activity ratios indicate that the performance is not good for Turnover of Assets value of 1 times. (8) For the rentability analysis KOPSUCOFINDO JAYA show results for ROA of 0.86% (2009), 1.31% (2010), 1.18% (2011), ROE in 2009 is 14.81%, 26.43% in 2010 and 2011 amounted to 31.11%, for the ROI of 0.56% in 2009, in 2010 was 0.96% and by 0.93% in 2011. (9) For the analysis of profitability, for the analysis of GPM in 2009 amounted to 1.49%, in 2010 of 2.31% and 3.92% in 2011. As for the analysis of NPM in 2009 amounted to 0.97%, in 2010 by 1.70% and by 3.10% in 2011. Keywords:  Cooperative Financial Performance, horizontal analysis, vertical analysis, Analysis of Liquidity, Solvency Analysis, Activity Analysis, Profitability Analysis, profitability analysis


2010 ◽  
Vol 56 (No. 5) ◽  
pp. 201-208 ◽  
Author(s):  
M. Beranová ◽  
D. Martinovičová

The costs functions are mentioned mostly in the relation to the Break-even Analysis where they are presented in the linear form. But there exist several different types and forms of cost functions. Fist of all, it is necessary to distinguish between the short-run and long-run cost function that are both very important tools of the managerial decision making even if each one is used on a different level of management. Also several methods of estimation of the cost function's parameters are elaborated in the literature. But all these methods are based on the past data taken from the financial accounting while the financial accounting is not able to separate the fixed and variable costs and it is also strongly adjusted to taxation in the many companies. As a tool of the managerial decision making support, the cost functions should provide a vision to the future where many factors of risk and uncertainty influence economic results. Consequently, these random factors should be considered in the construction of cost functions, especially in the long-run. In order to quantify the influences of these risks and uncertainties, the authors submit the application of the Bayesian Theorem.


Games ◽  
2021 ◽  
Vol 12 (3) ◽  
pp. 53
Author(s):  
Roberto Rozzi

We consider an evolutionary model of social coordination in a 2 × 2 game where two groups of players prefer to coordinate on different actions. Players can pay a cost to learn their opponent’s group: if they pay it, they can condition their actions concerning the groups. We assess the stability of outcomes in the long run using stochastic stability analysis. We find that three elements matter for the equilibrium selection: the group size, the strength of preferences, and the information’s cost. If the cost is too high, players never learn the group of their opponents in the long run. If one group is stronger in preferences for its favorite action than the other, or its size is sufficiently large compared to the other group, every player plays that group’s favorite action. If both groups are strong enough in preferences, or if none of the groups’ sizes is large enough, players play their favorite actions and miscoordinate in inter-group interactions. Lower levels of the cost favor coordination. Indeed, when the cost is low, in inside-group interactions, players always coordinate on their favorite action, while in inter-group interactions, they coordinate on the favorite action of the group that is stronger in preferences or large enough.


2021 ◽  
Vol 2 (143) ◽  
pp. 174-183
Author(s):  
Andrey Yu. Nesmiyan ◽  
◽  
Anastasiya S. Kaymakova ◽  
Yuliya S. Tsench ◽  

Most modern agricultural machines and tools consist of components, the main parameters, design features of which were justified in the first half of the twentieth century. Slowly and evolutionarily, these technical means are developing. (Research purpose) The research purpose is in identifying general trends in the technical and technological level of steam cultivators in the first quarter of the XXI century. (Materials and Methods) For the study there was analyzed the data of the short test reports of the selected machines. The production of steam cultivators in the Russian Federation is gradually increasing. (Results and discussion) For ten years of the beginning of the XXI century, only 27 machines were provided for testing, and from 2014 to 2017 – more than 40, while for "old" cultivators, the weighted average value of the tractor traction class was 2.8, for new ones it is about of four. For the study period (on average 10 years) the quality of soil cultivation in terms of such parameters as deviation from the specified depth of cultivation, crumbling and combing of the field surface has not changed much. The productivity of cultivator units increased by 7-21 percents, which is explained not only by an increase in the power of tractors, but also by an increase in the utilization rate of charge time on average from 0.72 to 0.77. The specific weight of the "new" cultivators was on average 22 kilogram-meters less than that of the "old" analogues, which can be explained by the evolution of their designs. (Conclusions) Increasing the class of tractors by one "level" the specific material consumption of the cultivators aggregated with them increases by about 58 kilogram-meters for both "old" and " new " cultivators. With an increase in the width of the tools from 4 to 16 meters, their weight will increase by 8 times, which affects the cost and operational and environmental characteristics of wide-reach cultivators.


2019 ◽  
Vol 30 (1) ◽  
pp. 122-134 ◽  
Author(s):  
Bojana Radovanovic

This paper discusses the relations between three forms of altruism: behavioural, evolutionary and motivational. Altruism in a behavioural sense is an act that benefits another person. It can range from volunteering to a charity and helping a neighbour, to giving money to a non-profit organisation or donating blood. People often dedicate their material and nonmaterial resources for the benefit of others to gain psychological, social and material benefits for themselves. Thus, their altruistic acts are driven by egoistic motivation. Also, the final goal of an altruistic act may be the increase in the welfare of a group or adherence to a certain moral principle or a social norm. However, at least sometimes, the welfare of others is the ultimate goal of our actions, when our altruistic acts are performed from altruistic motivation. In evolutionary sense, altruism means the sacrifice of reproductive success for the benefit of other organisms. According to evolutionary theories, behaviour which promotes the reproductive success of the receiver at the cost of the actor is favoured by natural selection, because it is either beneficial for the altruist in the long run, or for his genes, or for the group he belongs to. However, altruism among people emerges as a distinctly human combination of innate and learned behaviours. Not only do we benefit the members of our own group, but we are capable of transcending our tribalistic instincts and putting the benefit of strangers at our own personal expense as our ultimate goal.


2019 ◽  
Vol 50 (5) ◽  
Author(s):  
Al-Mashhdani & Mahmood

The aim of this study was to estimate the profit and cost functions as well as economic, price, cost, and technical efficiencies beside the other economic indices at actual, optimal and profit-maximizing output of rice. A random sample of 240 rice  farms in Nejaf province was used during the agricultural season 2016. From efficiency scales of profit function, it was shown that the output quantity had the greatest impact on the profit compared to other variables (average output costs and price). According to the cost function, the optimum output level and the profit- maximizing output  level for the short run were 64.84 tons and 117.4 tons respectively. The lowest price that the farmer can accept was 194.83 thousand dinars / ton. At this price, the producer loss all fixed costs in the short run, hoping that the price of rice will improve in the long run. Net profit was estimated on the basis of actual output, cost minimizing output (optimal) and profit-maximizing output, which amounted to 8084.32, 30852.65 and 45547.5 thousand dinars, respectively. The of technical efficiency were 34%. and the cost efficiency was 0.52. We conclude from the study that economic resources have not been exploited optimally, indicating that actual output is far from optimal output. The study recommends a output policy aimed at increasing economic efficiency and optimizing the use of available resources.


2017 ◽  
Author(s):  
Bryce Morsky ◽  
Dervis Can Vural

AbstractMuch research has focused on the deleterious effects of free-riding in public goods games, and a variety of mechanisms that suppresses cheating behavior. Here we argue that under certain conditions cheating behavior can be beneficial to the population. In a public goods game, cheaters do not pay for the cost of the public goods, yet they receive the benefit. Although this free-riding harms the entire population in the long run, the success of cheaters may aid the population when there is a common enemy that antagonizes both cooperators and cheaters. Here we study models in which an immune system antagonizes a cooperating pathogen. We investigate three population dynamics models, and determine under what conditions the presence of cheaters help defeat the immune system. The mechanism of action is that a polymorphism of cheaters and altruists optimizes the average growth rate. Our results give support for a possible synergy between cooperators and cheaters in ecological public goods games.


Author(s):  
Farhan Yasin Hamed Farhan Yasin Hamed ◽  
Lydia Mikhailovna Vasilyeva ◽  
Natalia Viktorovna Sudakova ◽  
Ali Attala Muheisin ◽  
Adelia Zakirovna Anokhina

The use of the crop rotation method in fish farming makes it possible to increase fish productivity and crop yields in ponds. In the countries of the Middle East, in recent years, the Aqua Crop rotation practice has been developing, in particular, the consistent cultivation of fish and rice in fish ponds, which allows eliminating the contradictions between these crops and increasing production efficiency. In Iraq, an experiment was carried out on the variable cultivation of rice and carp in fish ponds for four years, with the aim of introducing this practice into the country’s agriculture. Four ponds, each with an area of 7.5 hectares, were involved. The research was carried out in two variants: in experiment No.1 rice was grown in the first year, fish in the second, then rice again and in the fourth year — fish, in the second experiment, on the contrary, at the beginning of the fish, then rice, etc. The fish-breeding season lasted 9 months (March to November). Fish-breeding indicators were studied in detail: survival rate, feed costs, fish productivity, the results of rice cultivation were judged by yield. In addition, indicators of economic efficiency were determined according to a simplified scheme. The results indicate that, in general, fish-breeding indicators turned out to be higher when growing fish in ponds after rice, so fish productivity increased by almost 30% with an average value of 3.9 t/ha, feed costs decreased, while rice yield increased by 15–16% and averaged 3.6 t/ha. The best fish-breeding indicators were obtained in the second experiment after rice was grown in the ponds for two years. Economic calculations confirmed the advantages of using the aquacrop rotation practice, so in the second experiment the cost of marketable fish decreased by 10%, and the profitability increased by almost 30%.


1998 ◽  
Vol 37 (01) ◽  
pp. 53-58 ◽  
Author(s):  
J. Högel ◽  
A. C. Rodloff ◽  
G. Büchele ◽  
W. Gaus

Abstract:Economic studies in medicine are intended to investigate costs, associated with a particular problem dealing with the indication, diagnosis or therapy, for instance, whether the high costs involved in a highly intensive or innovative therapy could be balanced by the eventual savings made, due to the shorter periods of treatment. In such situations a randomized controlled trial is necessary to find out which therapy or which therapeutical strategy is least expensive in the long run. Economic studies do, however, present some specific problems. Making a list of all the cost-relevant treatment items can be very laborious, but the use of flat rates and lump sums alone cannot lead to a complete cost analysis. Often, costs between hospitals vary more than between treatment regimens.Early and sudden deaths incur low costs and may bias the results. Furthermore, costs are distributed with a long and heavy upper tail incltJding extreme outliers. This does, in fact, complicate the estimation of the sample size. In this article, these problems are outlined and, with the help ofthe data obtained from two randomized economic trials in health care, solutions are proposed and discussed.


Author(s):  
Tilman Slembeck ◽  
Armin Jans ◽  
Thomas Leu

Financial sustainability requires governments to run sufficiently large primary surpluses going forward to cover the cost of servicing its debt budgets to balance in the long run. In democracies, politicians who strive for reelection often tend to systematically violate this tenet. This paper discusses two types of “anchors” that may be used to cope with this problem by limiting the room for new and excessive public debt. First, we analyze national constitutional safeguards on the basis of the “debt brake” in Switzerland and Germany. Second, we discuss international institutions to maintain financial discipline, referring to the Maastricht-criteria. These anchors are designed to allow policymakers to commit to policies that provide long term financial stability and sustainability of public finances. However, as the recent crises have shown, the problem of time inconsistency in policy making remains, especially when anchors are weak. Therefore, the paper discusses the circumstances under which institutional anchors may help to restrict politician behavior to promote sustainability of public finances. We conclude by indentifying three conditions required for the proper functioning of collective anchors in the context of public finances.


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