Impact of Safety-Maintenance Practices on the Overall Performance of an Industry

The study aims to evaluate how safety-maintenance practices affect the mechanical engineering industry’s overall performance in Ghana. The study used a descriptive survey design technique to ascertain the type of maintenance engineering that was practiced in Ghanaian mechanical engineering workshops at the time of the study. In the mechanical engineering workshops, respondents provided both qualitative and quantitative data using a variety of data collecting instruments, with the quantitative approach being more common. The study employed Kumasi, Tamale, and Accra’s mechanical engineering workshops as a case study. The number of mechanical engineering workshop enterprises that made up the sample size for the questionnaire administration was sixty (60), chosen at random from the AGI membership registry. Primary data was gathered using interview guides and questionnaires. To analyse the data, descriptive statistics were employed. According to the study’s findings, mechanical engineering companies combined different maintenance techniques in order to best fit their organisational culture and equipment. Preventive shut-down, with a mean score of 4.78 and RII = 0.98, placing first (1st) in the Likert rating order, is the most frequently used maintenance system by respondents. The maintenance procedures employed by mechanical engineering organisations were influenced not only by their equipment and organisational culture but also by other factors such as cost, personnel expertise and external partnerships.

A Dynamic Maintenance Strategy for Multi-Component Systems Using a Genetic Algorithm

In multi-component systems,the components are dependent,rather than degenerating independently,leading to changes inmaintenance schedules.In this situation,this study proposes a grouping dynamicmaintenance strategy.Considering the structure of multi-component systems,the maintenance strategy is determined according to the importance of the components.The strategy can minimize the expected depreciation cost of the system and divide the system into optimal groups that meet economic requirements.First,multi-component models are grouped.Then,a failure probability model of multi-component systems is established.The maintenance parameters in each maintenance cycle are updated according to the failure probability of the components.Second,the component importance indicator is introduced into the grouping model,and the optimization model,which aimed at a maximum economic profit,is established.A genetic algorithm is used to solve the non-deterministic polynomial(NP)-complete problem in the optimization model,and the optimal grouping is obtained through the initial grouping determined by random allocation.An 11-component series and parallel system is used to illustrate the effectiveness of the proposed strategy,and the influence of the system structure and the parameters on the maintenance strategy is discussed.

A New Method to Optimize the Maintenance Strategy of HVDC Transmission System

A method based on fuzzy comprehensive evaluation to optimize the maintenance strategy of HVDC transmission system is proposed to provide quantitative reference for the maintenance arrangements. Firstly, a system based on fuzzy comprehensive evaluation, is established to fuzzy the index results of power system adequacy evaluation, so as to analysis the degree of risk in the operation of power system and the effect brought by the maintenance of HVDC. Then, the proposal on the maintenance of HVDC can be formed through the quantization and evaluation summary of the fuzzy results. The equivalent network of the China Southern Power Grid in 2011 ,which respectively operates in the circumstances of peak load, general load and low load, demonstrates the HVDC transmission systems in different operation modes have corresponding Overhaul timing .The result shows that the method proposed is valid and in accordance with engineering practice.

Evaluation of Maintenance Strategies Based on Leakage Risk Assessment on Side Impervious Walls at Coastal Landfill Sites

Asset management is a strategic decision-making aspect of social infra-structure that ensures safety by predicting long-term conditions and maximizing effectiveness under budgetary constraints. Predicting the deterioration of impervious walls is essential in the asset management of coastal landfill sites, particularly in the design of their maintenance and repair strategy. In this paper, a quantitative evaluation of the leakage of toxic substances in coastal landfill sites where deterioration of side impervious walls has decreased the water interception performance is reported. In addition, risk evaluation based on the asset management of the leakage is applied to determine an appropriate repair method. The strategy of repairing the walls when the concentration of the toxic substances leaking into the sea area exceeds the closure and abandonment of coastal landfill sites is demonstrated to be superior. Moreover, the strategy of repairing only the seaside side impervious wall is shown to be cost-effective.

Optimization of Equipment Maintenance Strategy Based on Availability

It is very important to optimize maintenance strategy in maintenance plan. Proper parameters play a decisive role for the optimization. In the opinion of writer, availability is a basic parameter, failure consequence cost and failure characteristic are also important parameters. Maintenance strategy can be optimized on the base by means of quantitative analysis and diagram.

Maintenance Strategies and Spare Parts Inventory Management for Use of Reconditioned Items

The maintenance management of construction equipment occupies a prominent place in the overall strategy for managing the equipment fleet. It is also linked to the management of the stock of spare parts and particularly reconditioned spare parts. Because of the relatively low purchase cost of these, most companies are tempted by this option. The purpose of this article is precisely to study the impact of this category of parts in the stock and also in the optimization of maintenance costs, knowing that to do this;their use must obey certain constraints. It is therefore important to be able to characterize these reconditioned parts by estimating their optimal age, and studying their advantages and also their limits. The determination of the optimal age of reconditioned parts will be such that the total cost of replacement with used parts is at most equal to the total cost of replacement with new parts at the end of the operating period.

Ship System Maintenance Strategy Selection Based on DELPHI-AHP-TOPSIS Methodology

Maintenance decision problems generally involve multiple criteria which apparently are best addressed using Multi-Criteria Decision Making (MCDM) tools. This paper describes the use of a hybrid MCDM technique in prioritizing maintenance strategy for ship systems. The Hybrid MCDM technique combines Delphi method, AHP and TOPSIS methods. While the Delphi method and AHP are applied in screening of decision criteria and decision criteria weights determination respectively, the TOPSIS method is used in the ranking of alternative maintenance strategies. Five alternative maintenance strategies which include corrected maintenance, scheduled overhaul, scheduled replacement, continuous on-condition task and scheduled on-condition task are considered and the optimum maintenance strategy is selected based on twelve critical maintenance decision criteria. To demonstrate the suitability of the approach a case study of sea water pump of the central cooling system of a marine diesel engine is used.

Machinery and Equipment Maintenance Strategy and Choice

The advantages, disadvantages and characteristics of various maintenance strategies for modern mechanical equipment are analyzed. Combined with the system structure and functional characteristics of engineering equipment,it puts forward the selection method of maintenance strategies for different types of equipment and failure modes. The view of this article is that the comprehensive maintenance strategy, which is based on condition based maintenance(CBM) and combines various maintenance strategies. This will become the main development direction of engineering equipment maintenance.

Strategies for Project-oriented Teaching Design of Automobile Inspection and Maintenance Course

Automobile Inspection and Maintenance Course is relatively practical and professional.Therefore,teachers need to provide students with opportunities for practice as much as possible,so that students can realize the integration of theory and practice,improve teaching efficiency.Project-oriented teaching design can enable students to participate in the practical training and maintenance of automotive engines,which helps students understand the theories in the book.This article mainly analyzes the strategies for teaching design of project-oriented Automobile Inspection and Maintenance Course.

Modern Maintenance Strategy of Electronic Equipment in Complex Electromechanical System

In this paper, the failure mechanism of electronic equipment was analysed.Aiming at the limitation of traditional maintenance modes, modern maintenance strategy was putforward on the basis of reliability-centered maintenance ( RCM) combined with condition-basedmaintenance ( CBM) and maintenance efficiency review (MER). A maintenance management informationsystem was constructed for electronic equipment for the purpose of failure analysis, reliabilityevaluation, and maintenance decisions such as time, mode, and plan. The best maintenance time couldbe predicted with failure analysis and reliability evaluation, which was mainly influenced byenvironmental stress. Suitable maintenance modes should be determined from equipment importance,failure aftereffect, maintenance condition, and economical power so as to ensure equipmentreliability and decrease the requirement of the maintenance source.

Study on Equipment Selective Maintenance Strategy Based on Performance

In this paper, an equipment selective maintenance strategy based on performance is brought forward according to the situation in China, in which reliability, computer technology, condition monitoring and management theory is applied. The theory points of the strategy are put forward. The maintenance strategy has been applied in mine hoist system.

Importance measure-based maintenance strategy optimization:Fundamentals,applications and future directions in AI and IoT

Numerous maintenance strategies have been proposed in the literature related to reliability.This paper focuses on the utilization of reliability importance measures to optimize maintenance strategies.We analyze maintenance strategies based on importance measures and identify areas lacking sufficient research.The paper presents principles and formulas for advanced importance measures within the context of optimizing maintenance strategies.Additionally,it classifies methods of maintenance strategy optimization according to importance measures and outlines the roles of these measures in various maintenance strategies.Finally,it discusses potential challenges that optimization of maintenance strategies based on importance measures may encounter with future technologies.

Product Modular Design Incorporating Preventive Maintenance Issues

Traditional modular design methods lead to product maintenance problems, because the module form of a system is created according to either the function requirements or the manufacturing considerations. For solving these problems, a new modular design method is proposed with the considerations of not only the traditional function related attributes, but also the maintenance related ones. First, modularity parameters and modularity scenarios for product modularity are defined. Then the reliability and economic assessment models of product modularity strategies are formulated with the introduction of the effective working age of modules. A mathematical model used to evaluate the difference among the modules of the product so that the optimal module of the product can be established. After that, a multi-objective optimization problem based on metrics for preventive maintenance interval different degrees and preventive maintenance economics is formulated for modular optimization. Multi-objective GA is utilized to rapidly approximate the Pareto set of optimal modularity strategy trade-offs between preventive maintenance cost and preventive maintenance interval difference degree. Finally, a coordinate CNC boring machine is adopted to depict the process of product modularity. In addition, two factorial design experiments based on the modularity parameters are constructed and analyzed. These experiments investigate the impacts of these parameters on the optimal modularity strategies and the structure of module. The research proposes a new modular design method, which may help to improve the maintainability of product in modular design.

A Maintenance Optimzation Policy for an Electric Power Distribution System: Case of the HV/MV Substations

Today, in the modern era, and under the pressure of rapid development around the kingdom regions, electric utilities are confronted with a myriad of challenges that include aging infrastructure, enhanced expectation of reliability, reduced cost, and coping effectively with uncertainties and changing regulation requirements. Indeed, for distribution systems, HV/MV substations represent a complex and critical physical asset that requires a careful evaluation of their maintenance practices aiming at more cost-effective tasks. The first concern of the electric power distribution company in Morocco is the optimization of the distribution network maintenance scheduling, to minimize system operating costs and ensure that the system is running most economically. There is significant pressure on power providers for greater system reliability and improvement of customer satisfaction, while similar emphasis is placed on cost reduction. These cost reductions focus on reducing operating and maintenance expenses, and minimizing investments in new plants and equipment. However, the present of the electricity distribution, influenced by a number of technical restrictions and strict regulatory requirements to meet, leads distribution utilities to search new ways of optimizing the maintenance management, make an effort to maximize profit by reducing their electricity supply and operation costs while maintaining their reliability, developing more effective activities, with lower costs. Furthermore, maximal HV/MV substation asset value and minimal maintenance cost are typical economic objectives of the electric utilities. The optimization of maintenance is one possible technique to reduce maintenance costs while improving reliability and utilities need to implement new strategies for more effective maintenance techniques and Asset Management (AM) methods programs to manage inspections and maintenance activities in order to control HV/MV substation equipment conditions. However, development of strategies to make sound decisions in order to effectively improve equipment and system reliability while meeting constraints such as a maintenance budget is a challenge. Finally, this paper describes the application of a new approach based Reliability Centered Maintenance (RCM) methodology to optimize maintenance resources and to the development of maintenance plan for HV/MV distribution substations. For this purpose, a case study was performed on the equipment of power distribution systems for the benefit of a holding company (ONEE Electricity Distribution) in Morocco. The present study was conducted in Oujda Exploitation Maintenance Service (OEXMS), in charge of operation and maintenance of distribution networks.

On the Problems of Computer Network Maintenance and Security

伴随我国计算机网络事业的快速发展，我们的生活已与网络紧密相联，但随着数据网络的传播，安全问题也开始出现。网络安全所涉及到的知识面较广，其中与网络安全存在着重要关联的就是计算机网络维护工作的质量。为此，本文就通过计算机网络维护保障网络安全的具体策略展开了进一步探讨，希望能为行业发展提供一定参考。

Reliability-Centered Maintenance-Based Maintenance Decision in New Nuclear Power Plants

Taking the project of introducing reliability-centered maintenance( RCM) into maintenance decision in an AP1000 nuclear power plant( NPP) under construction as the research object,an improved RCM methodology was proposed, and the application software and an RCM-based maintenance strategies management system were designed. In the pilot project,the RCMbased maintenance decision methodology had been applied to determining the maintenance strategies for two systems. Both the decision process and the results were described in this paper. The achievements of this project promoted the introduction and routinization of an advanced and effective maintenance decision mode in nuclear power field,which could provide valuable reference for new NPPs in China.

Framework for Observing the Maintenance Needs, Runtime Metrics and the Overall Quality-in-Use

The post-release maintenance is usually the most expensive phase in the software product lifecycle from the first design concepts to the end of product support. To reduce the costs related to post-release maintenance, we propose a run-time framework for measuring software quality characteristics applying the ISO/IEC 25000 software quality and software quality in use models as the starting point. Measurement probes are linked into the software during the development phase and used to collect quality information during the run time. As a proof-of-concept, we implemented measurements in an open-source software project to demonstrate the utility of the framework. As a result, this paper presents a framework for collecting runtime metrics and measuring software quality-in-use with a systematic interface. Additionally, examples of measurement scenarios are presented.

Trizivir (Abacavir/Lamivudine/Zidovudine) plus Lopinavir/Ritonavir Induction Therapy Followed by Trizivir-Alone Maintenance for HIV-1-Infected Patients: A 96-Week Pilot Treatment Simplification Study

Objective: The purpose of this study was to investigate whether switching HIV-infected patients stabilized on Trizivir (abacavir 300 mg/lamivudine 150 mg/zidovudine 300 mg) plus lopinavir/ritonavir 400 mg/100mg twice daily to Trizivir alone affects clinical efficacy and tolerability. Methods: This phase 4, open-label, pilot study was conducted over 96 weeks in 23 antiretroviral-na?ve, HIV-infected patients. Initially, these patients received induction therapy with Trizivir plus lopinavir/ritonavir 400 mg/100mg twice daily. Patients who achieved a viral load 3. Nineteen patients completed induction;of the four who did not, three were lost to follow-up and one withdrew due to gastrointestinal adverse events. In 14 induction completers who had viral load measurements taken at week 48, intent-to-treat: observed analysis showed a week 48 viral load 3 higher than the baseline count. Twelve patients completed the subsequent 48-week Trizivir-alone maintenance phase, of whom 11 (92%) achieved viral loads of both 3 above baseline. Trizivir-only maintenance was associated with fewer adverse events than the Trizivir-lopinavir/ritonavir induction phase and with improvement in total cholesterol, LDL-cholesterol, and triglycerides. Conclusions: Trizivir-alone maintenance after Trizivir-lopinavir/ritonavir induction maintained virologic and CD4+ cell response, and was associated with an improved adverse event and lipid profile.

网络安全运维工作中的攻击与防御

网络安全是指网络系统的硬件、软件及其系统中的数据受到保护,不因偶然的或者恶意的原因而遭到破坏、更改、泄露。在数据时代,信息安全逐渐成为人们关注的焦点。基于此,文章主要分析了网络安全运维工作中的攻击类型与防御策略。

工程机械维修与保养管理的优化策略研究

工程机械在现代化生产中有着不可替代的作用,然而在多年的生产运营中,工程机械的维修与保养管理却一直是困扰企业的痛点之一。长期以来,工程机械的维修与保养管理面临着预防性维修不足、维修人员技能水平不足等问题,导致设备的运行效率与可靠性都无法得到有效提升。因此,对工程机械维修与保养管理进行优化策略研究势在必行。本文研究其当前维修与保养管理存在的问题以及优化策略,旨在为研究优化工程机械维修与保养管理提供参考。