A parabolic model in the form of space states of the dynamics of savings

An important place in the theory of partial differential equations and its applications is occupied by the heat equation, a representative of the class of the so-called parabolic equations. It is known that to check the correctness of a mathematical model based on a parabolic equation, the existence of its solution is very important since a mathematical model is not always adequate to a specific phenomenon and the existence of a solution to a corresponding mathematical problem does not follow from the existence of a solution to a real applied problem. Therefore, methods for solving partial differential equations, both analytical and numerical, are always relevant. Nowadays, a computational experiment has become a powerful tool for theoretical research. It is carried out over a mathematical model of the object under study, but at the same time, other parameters are calculated using one of the parameters of the model and conclusions are drawn about the properties of the object or phenomenon under study. The problem of passive parametric identification of systems with distributed parameters for resource accumulation dynamics of many households using a stochastic distributed model in the form of a state space with regard to the white noise of the dynamics model of the object under study and the white noise of the model of a linear-type measuring system is considered in the paper. The use of the finite difference method allowed us to reduce the solution of partial differential equations of a parabolic type to the solution of a system of linear finite difference and algebraic equations represented by models in the form of a state space. It was also proposed to use a filtering algorithm based on the Kalman scheme for reliable estimation of the object behavior. Calculations were carried out using the Matlab mathematical system based on statistical data for five years, taken from the site “Agency for Strategic Planning and Reforms of the Republic of Kazakhstan Bureau of National Statistics”. Estimation of the coefficients of the equations for the household resource accumulation in the form of a state space using this technique is sufficiently universal and can be applied in other fields of science and technology.

The antecedents of sustainable shipping management and organisational performance: resource accumulation and orientation perspectives

PurposeSustainable shipping management (SSM) has received much attention from shipping companies in recent years. Grounded on resource accumulation and orientation perspectives, this study aims to identify the antecedents of SSM and examine their effects on the performance (i.e. shippers' loyalty and financial performance) of shipping companies.Design/methodology/approachA model comprising a network of hypotheses that specifies the relationships between the antecedents, SSM, shippers' loyalty and financial performance was constructed. Subsequently, a survey questionnaire was designed. Survey data were then collected from 294 shipping companies located in Vietnam and analysed using structural equation modelling.FindingsThe findings indicate that the five antecedents have significant effects on the effectiveness of SSM. They are stakeholders' focus, strategic orientation, supply chain collaboration, sustainability resource development and sustainability technology development. Bootstrapping analysis indicates that SSM has significant direct and indirect effects on financial performance via shippers' loyalty.Research limitations/implicationsApplied perspectives are complementary and offer unique explanations to SSM. However, the orientation perspective offers stronger explanation. This study also improves the allocation of resources and capabilities in managing sustainability to enhance the organisational performance of shipping companies.Originality/valueThis study synthesises the sustainability and strategic management literature to identify the antecedents of SSM.

The effects of exercise on organizational and personal outcomes : a work-home resources perspective

In the organizational sciences, daily exercise research has largely centered on how exercise replenishes resources depleted by work and thus facilitates recovery during off-work time. However, we know little about whether exercise generates resources that influence individuals at work and subsequently at home, and under what conditions. I theorized that daily exercise results in resource accumulation that leads to more organizational citizenship behaviors, higher job satisfaction, and better job performance. Subsequently, I theorized better work outcomes are associated with a sense of accomplishment that leads to more sharing behaviors at home. I also theorized that the resource accumulation from exercise may depend on contextual characteristics of the exercise (i.e., time of day and accompanied) and individual differences (i.e., autonomous motivation and physical fitness). To test the theorized model, 102 respondents from two different organizations answered three surveys a day for 10 work days. Multi-level modeling was used to test the hypotheses. Results indicated that exercise was associated with greater OCBs, job satisfaction, and job performance via the resources of positive affect, mental focus, and energy. However, the gain in positive affect was strongest for employees who were less fit. OCBs, job satisfaction, and job performance were associated with feelings of accomplishment. The findings illustrate the importance of daily exercise for generating resources useful for outcomes at work. I hope to offer insight into the importance of an expanded view of the role of daily exercise for employees.

The Atlantic War, 1939–1945

This chapter by Marc Milner challenges the popular perception of the "Battle of the Atlantic" as a shooting war, and the notion that Allied strategy was impaired by the depredations of Germany's U-boats. He asserts that the Atlantic war of 1939-45 is better understood like the great maritime wars of the age of sail, in which battle played a small part in the larger struggle for resource accumulation and the application of power ashore. The British and Canadians understood the Atlantic war in precisely this way, and focused on avoidance of the enemy as their primary method of defending shipping. In contrast, the USN followed a Mahanian concept of naval warfare in which destruction of the enemy was the underlying concept of escort operations. In this "new" paradigm, the Allied (really British) victory over the U-boats in 1943 was not something that could be achieved quickly. Rather, like the Battle of Trafalgar in 1805, it was the culmination of a long process that forced the enemy to stand and fight in a campaign he had already lost.

Explore/exploit tradeoff strategies in a resource accumulation search task

How, and how well, do people switch between exploration and exploitation to search for and accumulate resources? We study the decision processes underlying such exploration/exploitation tradeoffs by using a novel card selection task. With experience, participants learn to switch appropriately between exploration and exploitation and approach optimal performance. We model participants’ behavior on this task with random, threshold, and sampling strategies, and find that a linear decreasing threshold rule best fits participants’ results. Further evidence that participants use decreasing threshold-based strategies comes from reaction time differences between exploration and exploitation; however, participants themselves report non-decreasing thresholds. Decreasing threshold strategies that “front-load” exploration and switch quickly to exploitation are particularly effective in resource accumulation tasks, in contrast to optimal stopping problems like the Secretary Problem requiring longer exploration.