Large Number Of Machines Research Articles

Developing a model for preventive maintenance management system and application database software

The manufacturing and service industries in developing countries have grown rapidly in the last few years. Most of the industries are equipped with large number of machines and equipments for which preventive maintenance (PM) is essential. To perform the maintenance activities, the facility manager, subordinates and customers need to track the status of the maintenance work on their assets and the associated costs of that work. This study proposes a model for PM management systems and develops the corresponding application database software supporting the proposed model. A case study is conducted in different industries to track the present status of the maintenance management and to select the features of the database software. The outcome of this research will benefit first and foremost the maintenance manager to manage the planning, day-to-day operations and maintenance activities.

A PTS-PGATS based approach for data-intensive scheduling in data grids

Grid computing is the combination of computer resources in a loosely coupled, heterogeneous, and geographically dispersed environment. Grid data are the data used in grid computing, which consists of large-scale data-intensive applications, producing and consuming huge amounts of data, distributed across a large number of machines. Data grid computing composes sets of independent tasks each of which require massive distributed data sets that may each be replicated on different resources. To reduce the completion time of the application and improve the performance of the grid, appropriate computing resources should be selected to execute the tasks and appropriate storage resources selected to serve the files required by the tasks. So the problem can be broken into two sub-problems: selection of storage resources and assignment of tasks to computing resources. This paper proposes a scheduler, which is broken into three parts that can run in parallel and uses both parallel tabu search and a parallel genetic algorithm. Finally, the proposed algorithm is evaluated by comparing it with other related algorithms, which target minimizing makespan. Simulation results show that the proposed approach can be a good choice for scheduling large data grid applications.

Automatically configuring the network layer of data centers for cloud computing

With the requirement of very large data centers for cloud computing, the challenge lies in how to produce a scalable and inexpensive design to interconnect a large number of servers in data centers while providing fault tolerance and high network capacity. Internet Protocol (IP)-based data center networks (DCNs) can support a sufficiently large number of machines and dynamic multi-path routing. However, the complex and error-prone manual configuration of IP-based DCNs hinders its deployment. In this paper, we propose DCZeroconf, a fully automatic IP address configuration mechanism, to eliminate the burden of manual configurations of the IP addresses of servers and switches in data centers. We have implemented a prototype system to validate the effectiveness of DCZeroconf via extensive experiments and simulations. The evaluation results demonstrate that DCZeroconf supports different topologies, and the assigned IP addresses can be automatically adjusted upon dynamic topology changes. In addition, the entire automatic process can be completed in seconds or less.

Classification analysis for simulation of the duration of machine breakdowns

Machine failure can have a significant impact on the throughput of manufacturing systems, therefore accurate modelling of breakdowns in manufacturing simulation models is essential. Finite mixture distributions have been successfully used by Ford Motor Company to model machine breakdown durations in simulation models of engine assembly lines. These models can be very complex, with a large number of machines. To simplify the modelling we propose a method of grouping machines with similar distributions of breakdown durations, which we call the Arrows Classification Method, where the Two-Sample Cramér-von-Mises statistic is used to measure the similarity of two sets of the data. We evaluate the classification procedure by comparing the throughput of a simulation model when run with mixture models fitted to individual machine breakdown durations; mixture models fitted to group breakdown durations; and raw data. Details of the methods and results of the classification will be presented, and demonstrated using an example.

Analysis of robust and adaptive designs for dynamic part population

Two types of cellular system designs are possible for a production environment consisting of dynamic part population: adaptive and robust layouts. Cellular manufacturing system designs in literature show that some of the cells formed have large number of machines compared to other cells. This paper is mainly concerned with developing suitable mathematical model so that more or less same number of machines in every cell is possible for the adaptive and robust designs. A genetic algorithm-based solution procedure is used to solve the problem. The suggested designs are giving less variation in cell size than adaptive and robust designs in literature.

DICE: an effective query result cache for distributed storage systems

Due to the proliferation of Internet and Intranet, the distributed storage systems have received a lot of attention. These systems span a large number of machines and store huge amount of data for a lot of users. In the distributed storage systems, a row can be directly accessed using a row key. We concentrate on a problem of efficient processing of queries whose predicate is on a column but not a row key. In this paper, we present a cache management technique, called DICE which maintains query results of range queries to support the next range queries. To accelerate the search time of the cached query results, we use modified Interval Ski Lists. In addition, we devise a novel cache replacement policy since DICE maintains an interval rather than a data item. Since our cache replacement policy considers the properties of intervals, our proposed technique is more efficient than traditional buffer replacement algorithms. Our experimental result demonstrates the efficiency of our proposed technique.

Application of dynamic benchmarking of rotating machinery for e-maintenance

The vibration analysis and condition monitoring technology is based on comparison of measurements obtained with benchmarks suggested by manufacturers or standards. In this case, the references provided by current rules are static and independent of parameters such as age, operational or environmental conditions in which the machine is analyzed. It creates false alarms and many unnecessary interventions. New communication technologies allow the integration of e-maintenance systems, production and real-time data or the result of vibration routes. The integration of all these data allows data mining and extraction of parameters to be incorporated into decision making typical of CBM, such as repairs, downtime, overhauls, etc. Absolute vibration data and spectral analysis of rotating machinery require the study of several signals by machine, which become hundreds of values and spectra to analyze where there, is a large number of machines. It is therefore necessary to find proper benchmark points to compare with vibration parameters. These parameters and benchmark points have to be adapted to the real status of the plant and vibratory conditions have to be automated to be easily understood by persons not connected with the detailed analysis of spectra. The trend of the measured data and its comparison with benchmarks should assess the success of the implementation of CBM and other decisions about implementation and changes in maintenance programs. This article proposes the use of two new indicators that result from data mining as a reference dynamic, not static as proposed by the standard, manufacturer or the expertise of maintenance technicians. These values show the real condition of the machine in terms of vibration. The application of these references to the decision making process of the maintenance manager and its inclusion in maintenance scorecard avoids unnecessary repairs caused by false alarms and thus prolongs the life of the equipment, resulting in the improvement of parameters such as the MTBF, in a e-maintenance system.

The Freudenstein equation

Ferdinand Freudenstein is widely acknowledged to be the father of modern kinematics of mechanisms and machines. His PhD thesis in 1954 and subsequent research papers by him and his students have influenced academic and industrial research, teaching and practice related to the analysis and design of mechanisms and machines throughout the world. In this article, we revisit Freudenstein’s thesis and the equation named after him. The Freudenstein equation results from an analytical approach towards analysis and design of four-link mechanisms which, along with its variants, are present in a large number of machines used in daily life.

A Multi-Dimensional Query Scheme in Structured Overlays

Structured peer-to-peer (P2P) systems are creating a large proportion of network traffic in today’s Internet. Peer-to-peer systems enable access to data spread over an extremely large number of machines. A P2P system typically involves thousands or millions of live peers in the network. Multi-dimensional data indexing has received much attention in a centralized database. In this paper, we propose and evaluate a multi-dimensional searching scheme in structured P2P networks. We present the design and implementation of a peer-to-peer index service for high dimensional data that is capable of handling complex queries. We design a VibIndex scheme in structured P2P overlay networks. We analyze this scheme’s performance and present simulation results. Our simulation results demonstrated the benefits of the proposed system and show that the approach is able to search efficiently.

International Perspectives

Humanitarian efforts by a large number of groups have provided care in many developing countries around the world, including southeast Asia. Beginning around 2000, Project Vietnam, a humanitarian organization supported, in part, by California Chapter 4 of the American Academy of Pediatrics, expanded its already established presence within Vietnam to include a focus that specifically addressed efforts to improve neonatal care and reduce mortality in that country. I became a part of this effort and joined the expanding team devoted to this mission. Part of the impetus for this change by the organization was the establishment of goals by the Vietnamese Ministry of Health (MoH) and the leaders of pediatrics within the country. These goals, stimulated by the millennium goals of the World Health Organization, were aimed at improving the care of newborns and developing systems of care to accomplish sustainable results in this important area of health care. Over the past 9 years, much progress has been made and many lessons have been learned in Vietnam. The improvements have led to reductions in mortality and to the expanded availability of higher-quality modern care for increasing numbers of patients. Such advances have come about through the hard work and dedication of individuals and several organizations such as Project Vietnam as well as the partnership with key leaders within the country. Perhaps as important as these tangible improvements is the information learned from successes and failures that may serve as the foundation of an organizational structure or paradigm that can be used to guide similar efforts elsewhere in the world. The following discussion is a compilation of experiences and descriptions of some of the centrally important events in which we have been involved. The models that have grown out of this include important generalizations with utility elsewhere. Although related by a …

Rule-based computing system for microbial interactions and communications: Evolution in virtual bacterial populations

We have developed a novel rule-based computing system of microbial interactions and communications, referred to as COSMIC-Rules, for simulating evolutionary processes within populations of virtual bacteria. The model incorporates three levels: the bacterial genome, the bacterial cell and an environment inhabited by such cells. The virtual environment in COSMIC-Rules can contain multiple substances, whose relative toxicity or nutrient status is specified by the genome of the bacterium. Each substance may be distributed uniformly or in a user-defined manner. The organisms in COSMIC-Rules possess individually-defined physical locations, size, cell division status and genomes. Genes and/or gene systems are represented by abstractions that may summate sometimes complex phenotypes. Central to COSMIC-Rules is a simplified representation of bacterial species, each containing a functional genome including, where desired, extrachromosomal elements such as plasmids and/or bacteriophages. A widely applicable computer representation of biological recognition systems based on bit string matching is essential to the model. This representation permits, for example, the modelling of protein–protein interactions, receptor–ligand interactions and DNA–DNA transactions. COSMIC-Rules is intended to inform studies on bacterial adaptation and evolution, and to predict behaviour of populations of pathogenic bacteria and their viruses. The framework is constructed for parallel execution across a large number of machines and efficiently utilises a 64 processor development cluster. It will run on any Grid system and has successfully tested simulations with millions of bacteria, of multiple species and utilising multiple substrates. The model may be used for large-scale simulations where a genealogical record for individual organisms is required.

An Inline Detection and Prevention Framework for Distributed Denial of Service Attacks

By penetrating into a large number of machines and stealthily installing malicious pieces of code, a distributed denial of service (DDoS) attack constructs a hierarchical network and uses it to launch coordinated assaults. DDoS attacks often exhaust the network bandwidth, processing capacity and information resources of victims, thus, leading to unavailability of computing systems services. Various defense mechanisms for the detection, mitigation and/or prevention of DDoS attacks have been suggested including resource redundancy, traceback of attack origins and identification of programs with suspicious behavior. Contemporary DDoS attacks employ sophisticated techniques including formation of hierarchical networks, one-way communication channels, encrypted messages, dynamic ports allocation and source address spoofing to hide the attackers' identities; such techniques make both detection and tracing of DDoS activities a challenge and render traditional DDoS defense mechanisms ineffective. In this paper, we propose the DDoS Container, a comprehensive framework that uses network-based detection methods to overcome the above complex and evasive types of attacks; the framework operates in 'inline' mode to inspect and manipulate ongoing traffic in real-time. By keeping track of connections established by both potential DDoS attacks and legitimate applications, the suggested DDoS Container carries out stateful inspection on data streams and correlates events among sessions. The framework performs stream re-assembly and dissects the resulting aggregations against protocols followed by various known DDoS attacks facilitating their identification. The traffic pattern analysis and data correlation of the framework further enhance its detection accuracy on DDoS traffic camouflaged with encryption. Actions available on identified DDoS traffic range from simple alerting to message blocking and proactive session termination. Experimentation with the prototype of our DDoS Container shows its effectiveness in classifying DDoS traffic.

A new heuristic for the n-job, m-machine flow-shop problem

This paper describes a new algorithm for solving the flow-shop scheduling problem of n/m/F/F max to minimize maximum flow time. A set of 2000 randomly produced problems of different sizes was solved and compared with three well-known heuristics. The result reveals that the new algorithm improves the best heuristics in performance measures by a significant percentage. Also, because the number of necessary operations for solving problems in this algorithm is independent of the number of machines involved, it is apt for systems with large numbers of machines. This work helps in solving flow-shop scheduling problems for manufacturing systems with large numbers of machines.

Supporting 3D and VR applications in a metacomputing environment

3D and VR applications require large amounts of computing time. In most applications it has to be available in a specific time span. In Cave or Immersive desk environments the power has to be available real-time. Much preparation can, however, be done on a longer time scale. Complex 3D applications in for instance the media industry require large computation power for rendering purposes in a timescale ranging from hours to a few days. Metacomputing environments, including a large number of machines, can be a useful tool for supporting these VR and 3D applications. Within the EROPPA project, a software environment for use by post production companies has been developed. Currently extensions to virtual surgery applications are investigated.

Solving the Generalized Machine Assignment Problem in Group Technology

Many existing solution methodologies for machine assignment problems in group technology do not consider factors such as part demand, operation sequence and cost of intercellular moves. We formulate a 0-1 quadratic programming model that takes into account these factors in machine assignment. Two approaches are proposed to solve this problem. The first is an A*-based approach that generates optimal solutions. The second is a heuristic approach developed to solve problems with large number of machines and/or parts. The heuristic approach is shown to be efficient in producing good solutions in a computational study.

Scalable approaches to load sharing in the presence of multicasting

This work examines policies based on multicasting for load sharing in a local area network environment. In these policies, lightly-loaded nodes join multicast groups to indicate their ability to accept additional work, and heavily-loaded nodes send multicast messages to locate these lightly-loaded nodes. Simulation is used to study the performance of these load sharing policies and compare them with previously proposed load sharing policies. The results show that multicasting is an efficient method for locating lightly-loaded nodes, yielding better response time compared to previous policies. In addition, the results show that multicast-based policies can be used to lessen network traffic to busy nodes and nodes on remote LANs, while scaling to large numbers of machines.

Single linkage versus average linkage clustering in machine cells formation applications

Machine cells formation is the process of identifying families of similar parts (part-families) and forming the associated machine cells such that one or more part-families can be processed within a single cell. Among approaches to the machine cells formation problem the similarity coefficient method (SCM) has the capability of incorporating manufacturing data such as production volume, sequence of operations, and processing times into the machine cells formation process. Single Linkage Clustering (SLINK) and Average Linkage Clustering (ALC) are two widely used clustering techniques based on SCM. While SLINK is simple and has minimal computational requirement, it may generate machine cells in which a large number of machines are far apart in terms of similarity. ALC, on the other hand, overcomes this problem but requires more computations. This paper discusses the application of these two techniques to the machine cells formation problem.

Grouting works in the construction of the side grout curtains of the al-Qadisiyah hydro development (Iraq)

1. The side curtains as necessary cutoff elements of the al-Qadisiyah hydro development were made in an optimal design variant, on time, and with a high quality. A considerable technical and economic effect was obtained by eliminating excessive volumes of works specified by the original design as a result of a combined analysis of the data of engineering surveys, investigations of experimental grouting works, and optimization of the grouting technology. 2. The index of unit cement absorption in the control holes used as the criterion of sufficiency of grouting on the side curtains should be used everywhere where the purpose of grouting works is to detect and eliminate large cavities and fissures. 3. Grouting works on elimination of karst cavities and large fissures, being in essence infill grouting, require the development of an industrial technology of the works with the use of considerable volumes of grouts (concretes) and use of a large number of machines and mechanisms (concrete plants, mixers, concrete pumps, etc.).

19—ECONOMIC CRITERIA FOR OPTIMIZING THE NUMBER OF MACHINES PER OPERATOR

The machine-minding problem is concerned with the running of a large number of machines by a single operator. The problem that is considered in this paper is how to determine the optimal number of machines that an operator can handle in a given situation. If he has too many, machines will break down and be out of action for a long time before being repaired. If he has too few, he will spend most of his time in waiting for a machine to break down. Economic criteria have been used to determine the optimal number, but only where the repair time is either constant or exponentially distributed. Neither of these is applicable in many situations, and the method has been extended to cover the case where the repair time follows an Erlangian distribution. The results are given in tabular form, so that the optimal number of machines can easily be determined if the appropriate system parameters are given. Also tabulated are the operator and machine efficiencies.

A Production Function for the Repairman Problem

In this paper we consider the repairmen problem from the point of view of production theory. This problem, which has a large literature,3 can be described as follows. There are m identical machines which operate independently and which normally require no human care. However, at any time a machine may break down and call for service, according to an exponential failure distribution. Furthermore, it is assumed that there are r repairmen, each capable of repairing one machine at a time. The time required for servicing a machine is again taken as a random variable with an exponential distribution. If fewer than r machines are being repaired a failed machine is immediately serviced. On the other hand, if r or more machines are being repaired, the failed machine joins a queue and waits for service. The queue discipline assumes that all repairmen are working if a machine is waiting, but it is otherwise arbitrary. If we let x(t) be the total output produced at time t, then x(t) is proportional to the number of machines operating at time t, n(t), which follows a stochastic birth and death process. Our purpose in this paper is to study the limiting behaviour of x(t) over time and, in particular, the behaviour of the expected value of x(t) as m and r become large. We here prove that as the number of machines and repairmen increases, expected output becomes, in a way to be specified below, proportional to the number of repairmen or to the number of machines, depending upon whether the ratio of repairmen to machines is below or above a certain value. It has previously been shown, by means of numerical calculations [4], that the production function relating expected output to the number of machines and to the number of repairmen exhibits smooth isoquants (with continuous marginal rates of substitution). It seemed, therefore, that the random character of the production process had introduced smoothing effects into an otherwise fixed-coefficients technology.4 But, as is proved here, for a large number of machines, the production function is of the fixed-coefficients type. In Figure 1, the isoquant relating the inputs per unit of output is seen to approach an L shape as m becomes large. The critical value (the ray OA) depends on the parameters of the stochastic process, i.e. the average failure time and the average repair time. More generally, it can be shown that the sequence of output processes, properly translated and scaled, tends to be a limiting diffusion process, the well-known OrnsteinUhlenbeck process.