scholarly journals Feasibility study of logging road elements plan

2021 ◽  
Vol 25 (3) ◽  
pp. 111-117
Author(s):  
S.Yu. Sablin ◽  
◽  
A.V. Skrypnikov ◽  
V.G. Kozlov ◽  
V.S. Prokopets ◽  
...  

The peculiarities of the research work are stated and the need for its further development is shown. Taking into account the structural links and limitations of the system, a mathematical model of the feasibility study of the total reduced costs of the route plan, the longitudinal profile and the width of the carriageway was compiled, which has a various amount of construction and operating costs reduced to the initial year in a predetermined search area. The objective function is determined, which is the main part of the mathematical model including all the elements and connections of the feasibility study of the timber haul roads elements. It is concluded that the search for the optimal combination of geometric elements and the timing of their change is an extreme task, and the best method for solving it is to determine the state of the system corresponding to the minimum value of the objective function, which is the sum of construction and operating costs reduced to the initial year.

2009 ◽  
Vol 626-627 ◽  
pp. 693-698
Author(s):  
Yong Yong Zhu ◽  
S.Y. Gao

Dynamic balance of the spatial engine is researched. By considering the special wobble-plate engine as the model of spatial RRSSC linkages, design variables on the engine structure are confirmed based on the configuration characters and kinetic analysis of wobble-plate engine. In order to control the vibration of the engine frame and to decrease noise caused by the spatial engine, objective function is choosed as the dimensionless combinations of the various shaking forces and moments, the restriction condition of which presents limiting the percent of shaking moment. Then the optimization design is investigated by the mathematical model for dynamic balance. By use of the optimization design method to a type of wobble-plate engine, the optimization process as an example is demonstrated, it shows that the optimized design method benefits to control vibration and noise on the engines and improve the performance practically and theoretically.


2021 ◽  
Vol 2107 (1) ◽  
pp. 012046
Author(s):  
I Y Amran ◽  
K Isa

Abstract The dynamic model and motion simulation for a Triangular-Shaped Autonomous Underwater Vehicle (TAUV) with independently controlled rudders are described in this paper. The TAUV is designed for biofouling cleaning in aquaculture cage fishnet. It is buoyant underwater and moves by controlling two thrusters. Hence, in this research work, the authors designed a TAUV that is propelled by two thrusters and maneuvered by using an independently controllable rudder. This paper discussed the development of a mathematical model for the TAUV and its dynamic characteristics. The mathematical model was simulated by using Matlab and Simulink to analyze the TAUV’s motion based on open-loop control of different rudder angles. The position, linear and angular velocities, angle of attack, and underwater vehicle speed are all demonstrated in the findings.


2017 ◽  
Vol 7 (1) ◽  
pp. 137-150
Author(s):  
Агапов ◽  
Aleksandr Agapov

For the first time the mathematical model of task optimization for this scheme of cutting logs, including the objective function and six equations of connection. The article discusses Pythagorean area of the logs. Therefore, the target function is represented as the sum of the cross-sectional areas of edging boards. Equation of the relationship represents the relationship of the diameter of the logs in the vertex end with the size of the resulting edging boards. This relationship is described through the use of the Pythagorean Theorem. Such a representation of the mathematical model of optimization task is considered a classic one. However, the solution of this mathematical model by the classic method is proved to be problematic. For the solution of the mathematical model we used the method of Lagrange multipliers. Solution algorithm to determine the optimal dimensions of the beams and side edging boards taking into account the width of cut is suggested. Using a numerical method, optimal dimensions of the beams and planks are determined, in which the objective function takes the maximum value. It turned out that with the increase of the width of the cut, thickness of the beam increases and the dimensions of the side edging boards reduce. Dimensions of the extreme side planks to increase the width of cut is reduced to a greater extent than the side boards, which are located closer to the center of the log. The algorithm for solving the optimization problem is recommended to use for calculation and preparation of sawing schedule in the design and operation of sawmill lines for timber production. When using the proposed algorithm for solving the optimization problem the output of lumber can be increased to 3-5 %.


Author(s):  
Sergey Smirnov

The article discusses a modern approach to risk management of the central counterparty,primarily the issue of the sufficiency of its financial resources, including the provision of clearingmembers, the capital of the central counterparty and the mutual liability fund. The main subject is the margining system, responsible for an adequate level of collateral for clearing members, that plays critical role in risk management, being the vanguard in protecting against losses associated with default by clearing members and the most sensitive to market risk part of the central counterparty’s skin of the game. A system of margining a portfolio of options and futures in the derivatives market is described, with default management based on the methodology proposed by a number of inventors, registered in 2004. For this system, a mathematical model of margining (i.e. determining the required level of the collateral) is built, based on the ideology of a guaranteed deterministic approach to superhedging: Bellman–Isaacs equations are derived from the economic meaning of the problem. A form of these equations, convenient for calculations, is obtained. Lipschitz constants for the solutions of Bellman–Isaacs equations are estimated. A computational framework for efficient numerical solution of these equations is created. Numerical experiments are carried out on some model examples to demonstrate the efficiency of the system. These experiments also show practical implications of marginsubadditivity — a crucial property of the mathematical model.


Energies ◽  
2020 ◽  
Vol 13 (1) ◽  
pp. 200 ◽  
Author(s):  
Krzysztof Rajski ◽  
Jan Danielewicz ◽  
Ewa Brychcy

In the present work, the effects of different operating parameters on the performance of a gravity-assisted heat pipe-based indirect evaporative cooler (GAHP-based IEC) were investigated. The aim of the theoretical study is to evaluate accurately the cooling performance indicators, such as the coefficient of performance (COP), wet bulb effectiveness, and cooling capacity. To predict the effectiveness of the air cooler under a variety of conditions, the comprehensive calculation method was adopted. A mathematical model was developed to simulate numerically the heat and mass transfer processes. The mathematical model was validated adequately using experimental data from the literature. Based on the conducted numerical simulations, the most favorable ranges of operating conditions for the GAHP-based IEC were established. Moreover, the conducted studies could contribute to the further development of novel evaporative cooling systems employing gravity-assisted heat pipes as efficient equipment for transferring heat.


Author(s):  
S-C Yang

This paper presents a method for determining the mathematical model of an elbow mechanism with a convex tooth and a concave tooth. Based on this method, the mathematical model presents the meshing principles of a conical cutter meshed with a tooth that is either convex or concave. Using the developed mathematical models and the tooth contact analysis, kinematic errors are investigated according to the obtained geometric modelling of the designed gear meshing when assembly errors are present. The influence of misalignment on kinematic errors has been investigated. The goal of the current study is to investigate von-Mises stress for three teeth contact pairs. A structural load is assumed to act on a gear of the proposed mechanism. The von-Mises of the proposed gear is determined. The conical cutter used in the design and manufacture of the convex and concave gear is shown. For example, the proposed mechanism with a transmission ratio of 3:2 was determined with the aid of the proposed mathematical model. Using rapid prototyping and manufacturing technology, an elbow mechanism with a convex gear, a concave gear and a frame was designed. The RP primitives provide an actual full-size physical model that can be analysed and used for further development. Results from these mathematical models are applicable to the design of an elbow mechanism.


2021 ◽  
Vol 114 ◽  
pp. 01020
Author(s):  
Arkadiy Plotnikov ◽  
Tatyana Goryacheva ◽  
Flyura Kazakova ◽  
Ekaterina Zakharchenko

This article is devoted to the further development of feedback loop models. They are used in the management of a single-industry firm. The development of the studying consists in the mathematical modeling of transients and assessing their impact on economic indicators. To solve this problem, the following was done in the article. A structural model of the functioning of a single-industry firm (SIF) is presented. It is built in accordance with the theory of automatic control (TAC) and includes elements: a management unit, a production unit, a sales unit, information nodes, as well as a feedback loop (FL). Equations and relationships describing the logic of the functioning of the company as a production system are presented. They allowed us to derive dynamic relationships and differential equations that reflect feedback loops on revenue and production costs. The system of expressions in operator form is presented, which describes the contour of the FL SIF. It has the form of a system of differential equations. It forms the basis of the mathematical model of SIF in the control system. This model made it possible to obtain a graphical interpretation of transients with closed and open FL based on the use of the Mathcad editor. Transients are fluctuations in sales volumes and production costs in the presence of disturbing influences. This is the scientific result and determines the novelty of the article.


2018 ◽  
Vol 7 (2) ◽  
pp. 57-62
Author(s):  
Muhammad Wakhid Musthofa

Makalah ini membahas tentang model matematika dampak perubahan iklim terhadap kondisi makroekonomi suatu negara. Dengan mengacu pada model pertumbuhan ekonomi endogen pada suatu negara, dengan fungsi output berbentuk fungsi Cobb-Douglas akan diturunkan model matematika yang mendeskripsikan dampak perubahan iklim terhadap kondisi makroekonomi suatu negara. Selanjutnya, akan dikonstruksikan pula fungsi ongkos yang berhubungan dengan model matematika yang telah diturunkan. Mengingat model matematika tersebut masih dalam bentuk sistem persamaan nonlinear, maka diperlukan proses linearisasi untuk menghasilkan model matematika yang linear sehingga memudahkan untuk dianalisis maupun diaplikasikan. [This paper discusses the mathematical model of the impact of climate change on the macroeconomic conditions of a country. By referring to an endogenous economic growth model in a country, with the output function in the form of a Cobb-Douglas function, a mathematical model will be described that describes the effects of climate change on the macroeconomic conditions of a country. Furthermore, it will also construct cost functions related to mathematical models that have been derived. Considering that the mathematical model is still in the form of a nonlinear equation system, a linearisation process is needed to produce a linear mathematical model that makes it easy to analyze and apply.]


Author(s):  
K. M. Muditha Dassanayake ◽  
Masaomi Tsutsumi ◽  
Ohta Katsunori

In this paper, a new motion: the two rotary axes simultaneous motion was proposed and the mathematical model which was used to carryout simulations was described. The effect of each deviation on the proposed motion was identified and described one by one. A methodology to estimate all the eight deviations which inherent to tilting rotary table type machining centers was described step by step. This methodology consists of two motions: the proposed motion and C axis radial direction motion. Both the two motions used only the rotary axes. All the motions can be run on one setup. The simulations were carried out by considering that the double ball bar as the measuring device. Furthermore, number of settings which can be used for the new motion were discussed. From this study, it was confirmed that this method can be used for estimate all the eight deviations, accurately.


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