Dynamic balance analysis of contamination control for hydraulic systems based on dynamic filtration ratio

2016 ◽  
Vol 68 (1) ◽  
pp. 45-51
Author(s):  
Guangying Ma ◽  
Shurong Ning ◽  
Yunlong Hu ◽  
jun Gao

Purpose – The aim of this study is to establish a dynamic model of the filtration ratio. For the problem that the measured value of the filtration ratio is far less than the theoretical value in the actual hydraulic filtering system, the paper aims to find the relationship between the filtration ratio and the parameters of the hydraulic systems, such as the contamination level and the dirt-holding quantity of the filter. Design/methodology/approach – The paper opted for the method of experimental analysis and simulation to determine the relationship between the filtration ratio and the parameters of the hydraulic system, and established a dynamic filtration ratio model. Findings – The paper provides a preliminary model of dynamic filtration ratio, and the model shows that the filtration ratio is exponentially related to the contamination level and the dirt-holding quantity. Different filters have different influence coefficients. The filtering capacity for a certain particle size and the contamination level control of the filter for different hydraulic systems can be judged according to the dynamic balance equation of hydraulic systems. Originality/value – The paper is useful in the selection of filters and in the precise control of the contamination level of the hydraulic system.

2012 ◽  
Vol 192 ◽  
pp. 360-364
Author(s):  
Xi Guang He ◽  
Ji Feng Xing ◽  
Jia Chen

In order to guarantee that the rudder hydraulic systems work normally, the rudder hydraulic system must supply constant-pressure fluid to it. In this article, the author had analyzed the relationship between the power of the hydraulic oil pump and its motor revs, and done researches on its controlling tactics. Next, the author deigned its controller and controlling system based on fuzzy-control theorem. This system could extend the life-span of the pump motor and save energy, and it can also be utilized in other engineering fields.


2016 ◽  
Vol 8 (3) ◽  
pp. 74-77
Author(s):  
Сазонова ◽  
Svetlana Sazonova

In practice, there are three forms of boundary conditions. The feature of the fourth form of the boundary conditions is that the relationship between the above nodal parameters before solving the problem cannot be defined neither in form nor in content. This situation occurs when the decomposition of the hydraulic system. The basis of this mechanism is to transform the basic model estimated in the secondary zone model based on the method of functional reduction. This method is essentially a synthesis of the known methods of transformation models based on the ideas of reduction, diakoptic and cybernetic modeling.


Author(s):  
О. М. Іванов ◽  
В. М. Арендаренко

Наведено результати теоретичних досліджень зіскладання розрахункової моделі гідрообприскувальноїустановки тунельного типу, призначеної для обприс-кування під високим тиском рослин у тунельній каме-рі. Дослідження проводились із залученням теоріїгідродинаміки та гідростатики для розрахунку скла-дних трубопроводів і багатокомпонентних гідравліч-них систем. За результатами розрахункових дослі-джень було складено аналітичні рівняння, що визна-чають величини гідравлічних параметрів у вузловихточках і встановлюють взаємозв’язок між основни-ми компонентами гідравлічної установки. The results of theoretical studies on the preparation of the computational model hydro spray tunnel designed for spraying high-pressure plants in the tunnel chamber. Studies were carried out using the theory of hydrodynamic and hydrostatic calculations for complex pipelines and multi-hydraulic systems. To achieve the objectives of the study were divided into components of hydraulic systems, each of which is a more simplified version of a complex pipeline. According to the results of computational studies were compiled analytical equations that determine the magnitude of hydraulic parameters at nodes and establish the relationship between the main components of the hydraulic system, and outlines the framework for the selection of a pressure pump for the amount of required pressure and flow.


2014 ◽  
Vol 602-605 ◽  
pp. 1417-1420
Author(s):  
Guang Ying Ma ◽  
Jun Gao ◽  
Yun Long Hu

According to statistical analysis of the actual situation and the existing data, the expression of the variable filtration ratio of the filter is given. Based on contamination control balancing equations of the hydraulic system, the variation curves of contamination level changing with time are obtained by Matlab/simulink. Through analysis of the example, the final expression of the variable filtration ratio of the filter is determined by fitting simulation results to the experimental data repeatedly, and the reliability of the expression is verified by compared with traditional fixed filtration ratio. For determining the true filtering performance of the filter and selecting the correct filter, this article has good theoretical guidance.


2017 ◽  
Vol 38 (5) ◽  
pp. 630-645 ◽  
Author(s):  
Won Ho Kim ◽  
Young-An Ra ◽  
Jong Gyu Park ◽  
Bora Kwon

Purpose The purpose of this paper is to examine the mediating role of burnout (i.e. exhaustion, cynicism, professional inefficacy) in the relationship between job level and job satisfaction as well as between job level and task performance. Design/methodology/approach The final sample included 342 Korean workers from selected companies. The authors employed the Hayes (2013) PROCESS tool for analyzing the data. Findings The results showed that all three subscales of burnout (i.e. exhaustion, cynicism, professional inefficacy) mediate the relationship between job level and job satisfaction. However, only two mediators (i.e. cynicism, professional inefficacy) indicated the mediating effects on the association between job level and task performance. Originality/value This research presented the role of burnout on the relationships between job level, job satisfaction, and task performance especially in South Korean organizational context. In addition to role of burnout, findings should prove helpful in improving job satisfaction and task performance. The authors provide implications and limitations of the findings.


2017 ◽  
Vol 21 (1) ◽  
pp. 12-17 ◽  
Author(s):  
David J. Pauleen

Purpose Dave Snowden has been an important voice in knowledge management over the years. As the founder and chief scientific officer of Cognitive Edge, a company focused on the development of the theory and practice of social complexity, he offers informative views on the relationship between big data/analytics and KM. Design/methodology/approach A face-to-face interview was held with Dave Snowden in May 2015 in Auckland, New Zealand. Findings According to Snowden, analytics in the form of algorithms are imperfect and can only to a small extent capture the reasoning and analytical capabilities of people. For this reason, while big data/analytics can be useful, they are limited and must be used in conjunction with human knowledge and reasoning. Practical implications Snowden offers his views on big data/analytics and how they can be used effectively in real world situations in combination with human reasoning and input, for example in fields from resource management to individual health care. Originality/value Snowden is an innovative thinker. He combines knowledge and experience from many fields and offers original views and understanding of big data/analytics, knowledge and management.


Author(s):  
Bartosz Wilczyński ◽  
Jakub Hinca ◽  
Daniel Ślęzak ◽  
Katarzyna Zorena

Rugby is a demanding contact sport. In light of research, poor balance, reduced jumping ability, muscle strength, and incorrect landing patterns might contribute to the increased risk of injury in athletes. Investigating the relationship between tests assessing these abilities might not only allow for the skillful programming of preventive training but also helps in assessing the risk of injury to athletes. Thus, the main purpose of this study was to investigate the relationship between dynamic balance, vertical and horizontal jumps, and jump-landings movement patterns. Thirty-one healthy amateur adolescent rugby players (age: 14.3 ± 1.6 years, height 171.4 ± 9.7 cm, body mass 80 ± 26 kg) participated in the study. Data were collected by the Y-balance Test (YBT), Counter Movement Jump (CMJ), Single Leg Hop for Distance (SLHD), and Landing Error Score System (LESS). Significant positive correlations were found between SLHD both legs (SLHDb) and YBT Composite both legs (COMb) (r = 0.51, p = 0.0037) and between SLHDb and CMJ (r = 0.72, p < 0.0001). A relationship was also observed between the CMJ and YBT COMb test (r = 0.51, p = 0.006). Moderate positive correlations were found between the dominant legs in SLHD and the posterolateral (r = 0.40, p = 0.027), posteromedial (r = 0.43, p = 0.014), and composite (r = 0.48, p = 0.006) directions of the YBT. These results indicate that variables that are dependent on each other can support in the assessment of injury-risk and in enhancing sports performance of young athletes.


2018 ◽  
Vol 10 (1) ◽  
pp. 85-110 ◽  
Author(s):  
Syed Zulfiqar Ali Shah ◽  
Maqsood Ahmad ◽  
Faisal Mahmood

Purpose This paper aims to clarify the mechanism by which heuristics influences the investment decisions of individual investors, actively trading on the Pakistan Stock Exchange (PSX), and the perceived efficiency of the market. Most studies focus on well-developed financial markets and very little is known about investors’ behaviour in less developed financial markets or emerging markets. The present study contributes to filling this gap in the literature. Design/methodology/approach Investors’ heuristic biases have been measured using a questionnaire, containing numerous items, including indicators of speculators, investment decisions and perceived market efficiency variables. The sample consists of 143 investors trading on the PSX. A convenient, purposively sampling technique was used for data collection. To examine the relationship between heuristic biases, investment decisions and perceived market efficiency, hypotheses were tested by using correlation and regression analysis. Findings The paper provides empirical insights into the relationship of heuristic biases, investment decisions and perceived market efficiency. The results suggest that heuristic biases (overconfidence, representativeness, availability and anchoring) have a markedly negative impact on investment decisions made by individual investors actively trading on the PSX and on perceived market efficiency. Research limitations/implications The primary limitation of the empirical review is the tiny size of the sample. A larger sample would have given more trustworthy results and could have empowered a more extensive scope of investigation. Practical implications The paper encourages investors to avoid relying on heuristics or their feelings when making investments. It provides awareness and understanding of heuristic biases in investment management, which could be very useful for decision makers and professionals in financial institutions, such as portfolio managers and traders in commercial banks, investment banks and mutual funds. This paper helps investors to select better investment tools and avoid repeating expensive errors, which occur due to heuristic biases. They can improve their performance by recognizing their biases and errors of judgment, to which we are all prone, resulting in a more efficient market. So, it is necessary to focus on a specific investment strategy to control “mental mistakes” by investors, due to heuristic biases. Originality/value The current study is the first of its kind, focusing on the link between heuristics, individual investment decisions and perceived market efficiency within the specific context of Pakistan.


2018 ◽  
Vol 52 (5/6) ◽  
pp. 1154-1184 ◽  
Author(s):  
Tom Chen ◽  
Judy Drennan ◽  
Lynda Andrews ◽  
Linda D. Hollebeek

PurposeThis paper aims to propose user experience sharing (UES) as a customer-based initiation of value co-creation pertaining to service provision, which represents customers’ level of effort made for the direct benefit of others in their service network. The authors propose and empirically examine a user experience sharing model (UESM) that explicates customer-to-customer (C2C) UES and its impacts on firm-desired customer-based outcomes in online communities.Design/methodology/ApproachBased on an extensive review, the authors conceptualize UES and UESM. By using online survey data collected from mobile app users in organic online communities, the authors performed structural equation modeling analyses by using AMOS 24.FindingsThe results support the proposed UESM, showing that C2C UES acts as a key driver of both firm-desired customer efforts and customer insights. The results also confirmed that service-dominant (S-D) logic-informed motivational drivers exert a significant impact on C2C UES. Importantly, C2C UES mediates the relationship between S-D logic-informed motivational drivers and firm-desired customer-based outcomes.Originality/valueThis study offers a pioneering attempt to develop an overarching concept, UES, which reflects customers’ initiation of value co-creation, and to empirically examine C2C UES. The empirical evidence supports the key contention that firms should proactively facilitate C2C UES.


2019 ◽  
Vol 15 (5) ◽  
pp. 669-687 ◽  
Author(s):  
Celia Álvarez-Botas ◽  
Víctor M. González-Méndez

Purpose The purpose of this paper is to analyse the effect of economic development on the influence of country-level determinants on corporate debt maturity, bearing in mind firm size and the period of financial crisis. Design/methodology/approach The authors employ panel data estimation with fixed effects to examine the role of economic development in influencing the relationship between country-level determinants on corporate debt maturity. The paper uses a sample of 30,727 listed firms, belonging to 39 countries, over the period 2005–2012. Findings Corporate debt maturity increases with the efficiency of the legal system and bank concentration and decreases with the weight of banks in the economy. However, the importance of these country determinants is greater in developing than in developed countries. The authors also show that firm size in developed and developing countries influences country determinants of corporate debt maturity. Finally, the results reveal that the financial crisis has affected the debt maturity of firms differently in developed and developing countries, with the effect of bank concentration lengthening debt maturity, this effect being more pronounced in developing countries. Practical implications The findings provide useful insights to guide policy decisions providing access to long-term financing, as corporate debt maturity depends on economic development, institutional environment, banking structure and firm size. Originality/value This study incorporates economic development in explaining the relationship between country-level determinants and corporate debt maturity.


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