Auxiliary Machines Research Articles

Transfer of Machined Patterns on an Aluminum Plate to Pyrex Glass Using Reactive Ion Etching SF<sub>6</sub> Plasma without Masks

A method for etching the surface of a Pyrex glass substrate using the Reactive Ion Etching process without the use of masks is reported. Variations in the machined surface on an auxiliary plate, manufactured in aluminum and placed below a Pyrex glass slide, were transferred to the upper surface of the substrate. SF6 as etching gas and low pressure chamber to promote the increase of mean free path of ions were used. Two etching ratios were found, general, that affects the entire surface of the substrate, and differential, which generates the relief on the surface of the glass. Differential etching depth showed a linear behavior with respect to time; the mean differential etching rate obtained was 43 nm/min. The same phase between the auxiliary plate machining and the etched pattern on the substrate is preserved. With this technique it was possible to manufacture convex and concave surfaces; some examples are given. The arithmetic mean roughness achieved with the proposed method was found to be N1 class, ideal for the development of optical corrector plates.

Cell design and loading with alternative routing in cellular reconfigurable manufacturing systems

This paper deals with the design and loading of a Cellular Reconfigurable Manufacturing System (CRMS) in the presence of alternative routing. A CRMS consists of multiple reconfigurable machining cells, each of which has Reconfigurable Machine Tools (RMT) and Computer Numerical Control (CNC) machines, a setup station and an automatic material handling and storage system. Each RMT has a library of feasible auxiliary machine modules for achieving a particular operational capability of the RMT. Each CNC machine has an automatic tool changer and a tool magazine of a limited capacity. The machine cell design problem involves the grouping of machines into machine cells. This problem is performed once, prior to the cell loading, using two cell formation methods from the literature. Once the resulting cells are physically implemented, a mixed-integer linear programming problem is developed for determining the routing mix (i.e. which proportion of each part type to be assigned to each alternative route) and the tool and module allocation (i.e. how many auxiliary modules and tools of each available type to be assigned to each RMT and CNC machine within each formed cell) in order to minimize total intercellular movements of parts. An illustrative problem and experimental results are presented.

The effect of dynamic operating conditions on nano-particle emissions from a light-duty diesel engine applicable to prime and auxiliary machines on marine vessels

This study presents the nano-sized particle emission characteristics from a small turbocharged common rail diesel engine applicable to prime and auxiliary machines on marine vessels. The experiments were conducted under dynamic engine operating conditions, such as steady-state, cold start, and transient conditions. The particle number and size distributions were analyzed with a high resolution PM analyzer. The diesel oxidation catalyst (DOC) had an insignificant effect on the reduction in particle number, but particle number emissions were drastically reduced by 3 to 4 orders of magnitude downstream of the diesel particulate filter (DPF) at various steady conditions. Under high speed and load conditions, the particle filtering efficiency was decreased by the partial combustion of trapped particles inside the DPF because of the high exhaust temperature caused by the increased particle number concentration. Retarded fuel injection timing and higher EGR rates led to increased particle number emissions. As the temperature inside the DPF increased from <TEX>$25^{\circ}C$</TEX> to <TEX>$300^{\circ}C$</TEX>, the peak particle number level was reduced by 70% compared to cold start conditions. High levels of nucleation mode particle generation were found in the deceleration phases during the transient tests.

The effect of dynamic operating conditions on nano-particle emissions from a light-duty diesel engine applicable to prime and auxiliary machines on marine vessels

This study presents the nano-sized particle emission characteristics from a small turbocharged common rail diesel engine applicable to prime and auxiliary machines on marine vessels. The experiments were conducted under dynamic engine operating conditions, such as steady-state, cold start, and transient conditions. The particle number and size distributions were analyzed with a high resolution PM analyzer. The diesel oxidation catalyst (DOC) had an insignificant effect on the reduction in particle number, but particle number emissions were drastically reduced by 3 to 4 orders of magnitude downstream of the diesel particulate filter (DPF) at various steady conditions. Under high speed and load conditions, the particle filtering efficiency was decreased by the partial combustion of trapped particles inside the DPF because of the high exhaust temperature caused by the increased particle number concentration. Retarded fuel injection timing and higher EGR rates led to increased particle number emissions. As the temperature inside the DPF increased from 25 °C to 300 °C, the peak particle number level was reduced by 70% compared to cold start conditions. High levels of nucleation mode particle generation were found in the deceleration phases during the transient tests.

Phase splitter for auxiliary machines in alternating-current locomotives

The operation of auxiliary machines in ac locomotives from a single-phase grid is considered. To obtain a symmetric three-phase voltage from a single-phase voltage, a static phase splitter must be employed, in the form of a single-phase reversible converter. The required power of this converter is no more than half the total power of all the consumers.

Air Preheaters Operating Situation and Analysis in Coal-Fired Generators

To prevent and dispose all kinds of problems occurred in the air preheaters of the large coal-fired power plants and improve the performance of the air preheaters, the representative problems of the air preheaters in Henan province was summarized with the statistical method. With specific cases, its adverse impact for boilers and auxiliary machines were analyzed. The main reasons for causing these problems were design flaws, maintain undeserved, poor blowing effect and high sulfur content in coal that can cause acid corrosion to the air preheaters. A series of countermeasures were put forward to resolve the problems.

Lapping Tool Wearing Uniformly in Machining Blind Hole of Workpiece in Manufacturing System

This paper proposes a new method of controlling abrasives density distribution on the machining surface of a lapping tool making full use of controllability of abrasives density distribution in solid abrasive lapping, based on the present actual problems in solid abrasive lapping blind holes in manufacturing process. This method makes the abrasives density distribution on the lapping tool surface fit the wear intensity distribution of lapping tool, which makes the lapping tool wear uniformly in this manufacturing process, does not lose its original surface accuracy, ensures shape accuracy of the machined holes of the workpiece, also avoids the trouble of dressing lapping tools, reduces auxiliary machining time, improves machining efficiencies, reduces the consumption of abrasives and reduces machining costs of the manufacturing process.

Modeling of a 1000 MW power plant ultra super-critical boiler system using fuzzy-neural network methods

A thermal power plant is an energy conversion system consisting of boilers, turbines, generators and their auxiliary machines respectively. It is a complex multivariable system associated with severe nonlinearity, uncertainties and multivariable couplings. These characters will be more evident when the system is working at a higher level energy conversion capacity. In many cases, it is almost impossible to build a mathematical model of the system using conventional analytic methods. The paper presents our recent work in modeling of a 1000MW ultra supercritical once-through boiler unit of a power plant. Using on-site measurement data, two different structures of neural networks are employed to model the thermal power plant unit. The method is compared with the typical recursive least squares (RLSs) method, which obviously demonstrated the merit of efficiency of the neural networks in modeling of the 1000MW ultra supercritical unit.

Auxiliary Specifications for Context-Sensitive Monitoring of AMS Assertions

As research on developing assertion languages for the analog and mixed-signal (AMS) domain gains in momentum, it is increasingly being felt that extensions of existing assertion languages like property specification language and SystemVerilog assertions into the AMS domain are not adequate for expressing the analog design intent. This is largely due to the intricacy of the analog behavioral intent which cannot be captured purely in terms of logic. In this paper, we show that by using auxiliary forms of formal specifications such as abstract state machines and real-valued functions, called auxiliary functions, as references for AMS assertions, it becomes possible to model complex AMS behavioral properties. In addition, we present complexity results for the satisfiability problem of such specifications. This approach leverages the growing adoption of AMS behavioral modeling in the industry. This paper also shows that the use of auxiliary state machines allows us to separate out the scope of different analog assertions leading to significant performance gains in the assertion checking overhead.

Computer-aided process planning for NC tool path generation of complex shoe molds

This paper presents a computer aided process planning (CAPP) system for numerical control tool path generation of complex shoe molds. This CAPP system includes both the automation of auxiliary boundary curve generation and machining strategies. The automation of auxiliary boundary curve generation and machining strategies make tool path generation more accurately and efficiently. Traditional shoe mold making is a very tedious process. Even with the utilization of computer-aided design and computer-aided manufacturing (CAD/CAM), the CAM process requires long hours of tool path programming and debugging. It would also take a long time to calculate (sometimes several hours) the tool path for complex athletic footwear. In order to reduce the tool path editing and programming time, this paper proposes the use of CAPP to reduce processing time and increase efficiency. It is difficult, if not impossible, to develop a generic CAPP system that can generate a process plan to solve general production problems. However, it is quite possible to capture the domain knowledge of a certain production process and embed that knowledge into a CAPP system. We prove, by using such a system, that a very complicated process planning problem can be overcome by a knowledge-based CAPP approach. With such an approach, the traditional manufacturing process of shoe molds can be converted to an automatic manufacturing process with the CAPP system. In fact, shoe molds for real production have been created using the developed CAPP system, demonstrating the effectiveness of this approach. In this paper, we show that several complex and different shoe molds and their machining strategies were automatically planned by the proposed CAPP system. The result of a comparison between the CAPP system with the traditional approach is presented and discussed.

Auxiliary state machines + context-triggered properties in verification

Formal specifications of interface protocols between a design-under-test and its environment mostly consist of two types of correctness requirements, namely (a) a set of invariants that applies throughout the protocol execution and (b) a set of context-triggered properties that applies only when the protocol state belongs to a specific set of contexts. To model such requirements, an increasingly popular design choice in the assertion IP design community has been the use of abstract context state machines and state-oriented properties. In this paper, we formalize this modeling style and present algorithms for verifying such specifications. Specifically, we present a purely formal approach and a semi-formal approach for verifying such specifications. We demonstrate the use of this design style in modeling some of the industry standard protocol descriptions and present encouraging results.

선체에서 발생하는 진동과 소음의 진단 및 평가

Most of vessels are not evaluated for their vibration and noise effects to human body. The vibration and noise generated by engine and auxiliary machine in vessel is a negative element for seamen. Therefore, in this paper, the diagnosis and evaluation of vibration and noise from vessel is accomplished by a shipbuilding corporation. The vibration and noise transferred from engine room and auxiliary machine was measured during the steady-state operation, and the vibration and noise map of vessel was made. Also, in order to evaluate the ship environment for human, the diagnosis is carried out on the base of measurement results.

Load Response Characteristics of the Proton Exchange Membrane Fuel Cell for Individual Cold-Region Houses

The power load pattern of an individual house is a set of loads that fluctuate rapidly. If it is controlled to follow a system at rapid load fluctuation, depending on the response characteristics of the system, the equipment may have poor power quality (voltage and frequency). When introducing a fuel cell system into a house, it is necessary to consider two transient response characteristics: electric power and heat power. Then, the details of the transient response characteristics of the fuel cell system composed from a reformer, a fuel cell, an inverter, a system interconnection device, etc., are investigated by experiment and numerical analysis. As a result, the control variables of the controllers and the relation to the response characteristics of the fuel cell system were clarified. Furthermore, the response characteristics of the system when accompanied by a load fluctuation of power were also clarified. The response characteristics when introducing the energy demand pattern of an individual cold-region house into a fuel cell system geothermal heat pump were analyzed. From this analysis result, the details of operation, including each auxiliary machine of the fuel cell system, were clarified.

Optimization of Information Rate Upper and Lower Bounds for Channels With Memory

We consider the problem of minimizing upper bounds and maximizing lower bounds on information rates of stationary and ergodic discrete-time channels with memory. The channels we consider can have a finite number of states, such as partial response channels, or they can have an infinite state space, such as time-varying fading channels. We optimize recently proposed information rate bounds for such channels, which make use of auxiliary finite-state machine channels (FSMCs). Our main contribution in this paper is to provide iterative expectation-maximization (EM) type algorithms to optimize the parameters of the auxiliary FSMC to tighten these bounds. We provide an explicit, iterative algorithm that improves the upper bound at each iteration. We also provide an effective method for iteratively optimizing the lower bound. To demonstrate the effectiveness of our algorithms, we provide several examples of partial response and fading channels where the proposed optimization techniques significantly tighten the initial upper and lower bounds. Finally, we compare our results with results obtained by the conjugate gradient optimization algorithm and an improved variation of the simplex algorithm, called Soblex. While the computational complexities of our algorithms are similar to the conjugate gradient method and less than the Soblex algorithm, our algorithms robustly find the tightest bounds. Interestingly, from a channel coding/decoding perspective, optimizing the lower bound is related to increasing the achievable mismatched information rate, i.e., the information rate of a communication system where the decoder at the receiver is matched to the auxiliary channel, and not to the original channel.

Surface Mine System Simulation and Safety Risk Management

Modern surface mines, either mono-system or multi-systems, need a large fleet of equipment consisting of excavators, loaders, haulers and auxiliary machines. Presently, the complexity of the system, the interference between sub-systems and the lag in management skills has been a bottle neck for improving productivity of the system. Based on the fact that the traditional tools for safety analysis have been insufficient to evaluate systematically and dynamically the safety risks, this paper tries to create a virtual reality tool consisting of human, machine and mines, using Pro/E and the 3D MAX software in order to evaluate visually the operations of typical mining equipment, such as the bucket wheel excavator (BWE), the shovel, the truck and the dragline. Within this virtual world, the behavior of the system, such as interaction, interference and potential risk can be replayed and reviewed visually. The objective of the study is to identify the critical safety issues of the system and to provide a convenient and powerful tool for safety training and safety management.

Cell formation in the presence of reconfigurable machines

In this research, an approach is made to design machine cells using modular machines to achieve certain characteristics of reconfigurable manufacturing. Each machine considered in the model consists of some basic and auxiliary machine modules. By changing the auxiliary modules, different operations can be performed on the machines. A similarity measure among machines based on production flow information and auxiliary module requirement is developed. Machine cells are identified using a multi-objective evolutionary genetic algorithm for a set of parts with parameters such as the volumes of production, alternative operation-based process plans, etc. The two objectives considered are the minimization of inter-cell movement and the total changes in auxiliary modules for the given production horizon. The resulting cell configuration is simulated to find the exact inter-cellular movements and the total number of module changes to validate the heuristic. An illustrative problem and experimental results are given.

Enhanced management method of storage area network (SAN) server with random remote backups

A SAN (storage area network) is a mass storage solution, that is, designed to provide a high-reliability and high-speed network over fiber optic link. This paper is dealing with the stochastic SAN server management method which is focused on reliability. The (remote) backup servers are hooked up by the long-haul network and replace broken main severs immediately. If the SAN servers are represented as “machines”, this system can be solved by using the stochastic maintenance model with main unreliable and random auxiliary spare (remote backup) machines, subject to random breakdowns, repairs, and two replacement policies: one for busy and another for idle or vacation periods. When the repair facility is not available because of the given conditions, auxiliary machines are being used for backups. Unlike existing models, the availability of auxiliary machines is changed for each activation of the system. Analytically tractable results are obtained by using a duality principle (which enables us to treat a more rudimentary system), semiregenerative analysis, and multivariate marked renewal processes. The results are demonstrated in the framework of optimized SAN server allocation problems with unreliable backup servers.

Review of thermal comfort design based on PMV/PPD in cabins of Korean maritime patrol vessels

This study has focused on the evaluation of the optimal temperature in each cabin of the Korean maritime patrol vessels. We aptly modified the inland indoor items and criteria of clothing and activities, and then investigated the human factors in the cabins of Korean maritime patrol vessels. The total thermal resistance of clothing in the wheelhouse was 0.097, 0.079, 0.096, and 0.130 m 2 °C/W and that for the accommodation areas was 0.067, 0.059, 0.084, and 0.101 m 2 °C/W in spring, summer, fall, and winter, respectively. The metabolic rate was 228.04 W/m 2 in the training room and above 100 W/m 2 in the engine room and auxiliary machine room. In the wheelhouse and accommodation, the metabolic rate was 78.14 and 44.45 W/m 2, respectively. Based on human factors, the optimum temperature was 23 °C in the wheelhouse and 29 °C in the accommodation. Therefore, 6 °C of energy can be saved in case of PMV/PPD-based air conditioning.

Simulated Annealing Based Heuristics to Minimize the Auxiliary Machine Area and Pipe Length Between Machines.

Semi-conductor manufacturers are aiming at saving initial cost (construction and land cost) and maintenance expenditure that are incurred in proportion of the clean room area. Especially for the 300 mm wafer factory, the equipments tend to be enlarged. The clean room area should be reduced to decrease construction cost by expelling the auxiliary machines out of the clean room. The auxiliary machines should be located compactly in order to minimize footprint under the clean room, and pipe length. We propose a "3 dimensional Maze method" applied algorithm to minimize total pipe length. In this research, at the auxiliary machine room of the downstairs of a clean room, the auxiliary machine arrangement problem which considered piping is modeled. We propose a new method to minimize auxiliary machine area and the total pipe length simultaneously. Simulated Annealing are used as the technique of optimization. Numerical examples demonstrate effectiveness of proposed algorithm

Using Program Schemes to Capture Polynomial-Time Logically on Certain Classes of Structures

AbstractIn this paper, the study of the expressive power of certain classes of program schemes on finite structures is continued, in relation to more mainstream logics studied in finite model theory and to computational complexity. The author shows that there exists a program scheme – whose constructs are assignments and while-loops with quantifier-free tests and which has access to a stack – that can accept a P-complete problem, the deterministic path system problem, even in the absence of non-determinism, so long as problem instances are presented in a functional style. (The proof given here leans heavily on Cook's proof that the classes of formal languages accepted by deterministic and non-deterministic logspace auxiliary pushdown machines coincide.) However, whilst this result is of independent interest, in that it leads to a deterministic model of computation capturing P, whose non-deterministic variant also captures P, the program scheme can also be used to build a successor relation in certain classes of structures (namely: the class of strongly connected locally ordered digraphs, the class of connected planar embeddings, and the class of triangulations), with the consequence that on these classes of graphs, (a fragment of) path system logic (with no built-in relations) captures exactly the polynomial-time solvable problems.