Estimation of the compression strength of corrugated fibreboard boxes and its application to box design using a personal computer

Many papers have been published on the compression strength of corrugated fibreboard boxes, using such formulae as Kellicut's equation and McKee's equation for the calculation. These equations, however, require known values of the strength of linerboard or corrugated fibreboard, they do not include the influence of moisture content and they are inadequate in the case of wrap-around boxes. The present author measured the mechanical properties of a large number of fibreboard boxes, and has derived a statistical formula useful for estimating the compression strength of a box based on its specifications — grade of corrugated fibreboard, size of box, type of box, printed area and moisture content. The calculation gives fairly good agreement with experimental results. The estimation technique has further been converted into a personal computer program, which renders the design of corrugated fibreboard boxes an easier task.     

Traffic fatalities and injuries: the effect of changes in infrastructure and other trends

An analysis of how various road infrastructure improvements affect traffic-related fatalities and injuries is conducted while controlling for other factors known to affect overall safety. The road infrastructure elements analysed include total lane miles, the fraction of lane miles in different road categories (interstates, arterial, and collector roads), the average number of lanes for each road category, and lane widths for arterials and collector roads. Other variables that are controlled for in the study include total population, population age cohorts, per capita income, per capita alcohol consumption, seat-belt legislation (and seat-belt usage), and a proxy variable that represents underlying changes in medical technology. The data used is a cross-sectional time-series database of US states and is analysed using a fixed effects negative binomial regression that accounts for heterogeneity in the data. Data from all 50 states over 14 years is used. Results strongly refute the hypothesis that infrastructure improvements have been effective at reducing total fatalities and injuries. While controlling for other effects, it is found that demographic changes in age cohorts, increased seat-belt use, reduced alcohol consumption and increases in medical technology have accounted for a large share of overall reductions in fatalities.     

Estimation of future breakdowns to determine optimal warranty policies for products with deterioration

Warranty has been played an important role not only for safeguarding the rights and interests of consumers but also for promoting the sales and reputation of manufacturers, since a good warranty policy signifies the image of high-quality products and thus becomes a powerful weapon for marketing products in increasingly competitive markets. It is obvious that a more thoughtful warranty policy of a product will attract more customers to consume the specific product, and increase the product's market share accordingly. However, an unlimited warranty for monopolizing the market is absolutely unrealistic, since the cost will significantly increase for maintaining such a warranty policy with better offers. In this paper, a Bayesian decision model for determining the optimal warranty policy for repairable products is proposed. The successive failure times of the repairable product are assumed to be drawn from a nonhomogeneous Poisson process. Both the repair costs for restoring the product to full functionality after each breakdown and the potential sales increases due to the specific warranty policy are also considered. Finally, an application case is utilized to demonstrate the feasibility and validity of the proposed approach.     

Estimation of fixed charge density and diffusivity profiles in cartilage using contrast enhanced computer tomography

Contrast enhanced computer tomography (CT) imaging of articular cartilage has been proposed for diagnostics of cartilage degeneration, that is, osteoarthritis. Previous studies also indicate that acute cartilage damage can be detected by measuring diffusion of contrast agent into cartilage using CT. However, currently, there is no reliable method to measure spatial diffusion rates within cartilage tissue, and only average bulk values have been reported. In this paper, we develop a method to determine depthwise diffusivity of contrast agents in cartilage tissue using contrast enhanced CT. The triphasic mechano‐electrochemical theory of cartilage is modified to include diffusion of contrast agents. By applying statistical inversion theory and Bayesian approximation error approach, the method allows us to estimate a fixed charge density distribution in the cartilage tissue, an important determinant for mechanical competence of articular cartilage. The method is tested by using a one‐dimensional simulation study. Preliminary tests with experimental data on diffusion of anionic iodine contrast agent in bovine articular cartilage indicate that the method can provide realistic estimates for depth dependent fixed charge density. Thereby, the present study can improve our understanding on the feasibility of contrast enhanced CT for cartilage diagnostics. Copyright © 2014 John Wiley & Sons, Ltd.     

Optimisation of the transmission of disruptions in assembly systems

The dynamic analysis of disruption transmission in networks of closed loops formed by machines and intermediate buffers is of vital importance in most production systems. Nevertheless, little research has been done on optimisation in this field. This study analyses the disruption time transmission in a generic assembly system, which has been modelled as a network of closed loops of machines and intermediate buffers. In addition, this modelling has been used to analyse a real automobile assembly line, taking into account variables that have not previously been considered in the literature, such as working regimes of machines, their cycle times, capacities of the intermediate buffers and their minimum contents. The optimal configuration of the intermediate buffers is analysed. Dynamic outlines of these kinds of assembly systems are proposed in order to maximise the transmission of disruption times and, hence, their availability. For this purpose, an algorithm for analysing and optimising availability in this kind of manufacturing system has also been developed.     

Thoughts on a methodology to analyse viability of private-sector participation in new infrastructure projects in developing countries

A model has been developed for investment analysis of all types of infrastructure projects: it addresses some of the key issues for developing countries regarding private-sector participation in infrastructure projects. As an illustration, financial analyses of a bulk water supply project and a water distribution project in Sri Lanka are carried out to estimate subsidy percentages required to make the projects viable. To reap maximum benefits from private-sector participation in water supply, the Government should review its policy on water pricing and institute a reasonable increase in tariffs.     

Material flow analysis and integration of watersheds and drainage systems: I. Simulation and application to ammonium management in Bahr El-Baqar drainage system

This paper is aimed at developing a systematic and generally applicable methodology for material flow analysis in drainage systems and watersheds. In particular, this research has focused on developing a mathematical framework and application for the management of nitrogenous species (primarily ammonium ions). Nitrogen compounds are among the most important species contributing to ecological cycles. Indeed, the environmental and biological aspects of water systems and their surrounding systems are highly impacted by nitrogen compounds as they contribute to the quality, nutrition, and toxicity of these systems. A material flow model was developed to deal primarily with the water phase while including pertinent information on the solid and air phases as they interface with the water medium. Both spatial and discrete temporal dimensions were included to account for nitrogen flow and transformation. The model includes the various environmental phenomena that influence the fate and transport of targeted species (e.g., volatilization, precipitation, sedimentation, uptake by biota, adsorption, chemical and biochemical reactions, etc.). Furthermore, the model includes material flow analysis operators (or transfer functions) that characterize the system inputs and outputs as they relate to the surroundings. The aforementioned material flow analysis tools were combined in a computer-aided modeling platform to provide a complete material flow analysis and yield useful insights on the transport and fate of targeted species. The simulation results shed light on the system performance. Actual data for an Egyptian drainage system (Bahr El-Baqar) along with the outfall to Lake Manzala were used to illustrate the usefulness and applicability of the developed model. Comparison with the measured data confirmed the validity and fidelity of the model.     

Thermoelectric cooling of microelectronic circuits and waste heat electrical power generation in a desktop personal computer

Thermoelectric cooling and micro-power generation from waste heat within a standard desktop computer has been demonstrated. A thermoelectric test system has been designed and constructed, with typical test results presented for thermoelectric cooling and micro-power generation when the computer is executing a number of different applications. A thermoelectric module, operating as a heat pump, can lower the operating temperature of the computer's microprocessor and graphics processor to temperatures below ambient conditions. A small amount of electrical power, typically in the micro-watt or milli-watt range, can be generated by a thermoelectric module attached to the outside of the computer's standard heat sink assembly, when a secondary heat sink is attached to the other side of the thermoelectric module. Maximum electrical power can be generated by the thermoelectric module when a water cooled heat sink is used as the secondary heat sink, as this produces the greatest temperature difference between both sides of the module.     

Current and future prospects of enhanced heat transfer in ammonia systems

In the last decade a moderate headway has been made in the application of enhanced surface heat exchangers in ammonia refrigeration systems. This has been a result of the persistent issue of ozone and global warming which has resulted in keen interest in natural refrigerants such as ammonia that has played a prominent role in the refrigeration industry for years, particularly in the field of food, beverage and marine. The only drawback with ammonia is the toxicity; hence, if smaller heat exchangers could be introduced in order to reduce ammonia charge, this negative aspect about ammonia can be addressed to a great extent. In order to achieve this goal, novel and compact heat exchangers with enhanced surfaces have to be introduced. This paper presents an over view of the status of ammonia as a refrigerant and discusses the present and the future trends in the development of compact heat exchangers for use in ammonia refrigeration.     

A Petri net-based approach to incremental modelling of flow and resources in service-oriented manufacturing systems

In order to overcome the myopia problem, routing strategies must be based on formal representations of flow that automatically account for modifications in the values of parameters of interest and in the model itself. This work addresses this problem and discusses how to automatically incorporate resources (e.g. workstations/transportation devices/storage) in a Petri-net-derived model of flow that is modifiable at runtime to reflect and influence the routing in a manufacturing line. The modelling approach takes into consideration scalability needs and was experimentally validated. The applicability of the models is shown for PN-based dynamic scheduling.     

Industrial Ecosystems and Food Webs: An Ecological-Based Mass Flow Analysis to Model the Progress of Steel Manufacturing in China

Materials and energy are transferred between natural and industrial systems, providing a standard that can be used to deduce the interactions between these systems. An examination of these flows is an essential part of the conversation on how industry impacts the environment. We propose that biological systems, which embody sustainability, provide methods and principles that can lead to more useful ways to organize industrial activity. Transposing these biological methods to steel manufacturing is manifested through an efficient use of available materials, waste reduction, and decreased energy demand with currently available technology. In this paper, we use ecological metrics to examine the change in structure and flows of materials in the Chinese steel industry over time by means of a systems-based mass flow analysis. Utilizing available data, the results of our analysis indicate that the Chinese steel manufacturing industry has increased its efficiency and sustainable use of resources over time at the unit process level. However, the appropriate organization of the steel production ecosystem remains a work in progress. Our results suggest that through the intelligent placement of cooperative industries, which can utilize the waste generated from steel manufacturing, the future of the Chinese steel industry can better reflect ecosystem maturity and health while minimizing waste.     

A new modeling approach to the safety evaluation of N-modular redundant computer systems in presence of imperfect maintenance

A large number of safety-critical control systems are based on N-modular redundant architectures, using majority voters on the outputs of independent computation units. In order to assess the compliance of these architectures with international safety standards, the frequency of hazardous failures must be analyzed by developing and solving proper formal models. Furthermore, the impact of maintenance faults has to be considered, since imperfect maintenance may degrade the safety integrity level of the system. In this paper, we present both a failure model for voting architectures based on Bayesian networks and a maintenance model based on continuous time Markov chains, and we propose to combine them according to a compositional multiformalism modeling approach in order to analyze the impact of imperfect maintenance on the system safety. We also show how the proposed approach promotes the reuse and the interchange of models as well the interchange of solving tools.     

Estimation of exponential component reliability from uncertain life data in series and parallel systems

Estimating reliability of components in series and parallel systems from masking system testing data has been studied. In this paper we take into account a second type of uncertainty: censored lifetime, when system components have constant failure rates. To efficiently estimate failure rates of system components in presence of combined uncertainty, we propose a useful concept for components: equivalent failure and equivalent lifetime. For a component in a system with known status and lifetime, its equivalent failure is defined as its conditional failure probability and its equivalent lifetime is its expectation of lifetime. For various uncertainty scenarios, we derive equivalent failures and test times for individual components in both series and parallel systems. An efficient EM algorithm is formulated to estimate component failure rates. Two numerical examples are presented to illustrate the application of the algorithm.     

Image analysis to reveal crack development using a computer simulation of wear and rolling contact fatigue

Plastic flow of near‐surface rail material under contact loading is a feature of rail–wheel contact, and severe flow typically leads to both wear, and the initiation and development of small surface‐breaking cracks. This paper presents results from a ratcheting based computer simulation, which has been developed to allow the simultaneous investigation of wear, crack initiation and early crack propagation. To identify repeatably small crack‐like flaws, image analysis is applied to the visual representation of the wearing surface generated by the model. This representation shows a good similarity to traditional micrographs taken from sections of worn surfaces. The model clearly reveals the interaction of wear with crack development, processes which are linked because wear truncates surface‐breaking cracks, and can completely remove small surface‐breaking cracks.     

Ageing workforce management in manufacturing systems: state of the art and future research agenda

The workforce ageing phenomenon is recently affecting most of the Organisation for Economic Co-operation and Development (OECD) member countries, due to a general ageing of their populations and a higher average retirement age of the workforce. In this paper, the topic of ageing workforce management is addressed from a production research standpoint, with the aim of understanding how older workers can be supported and involved in a manufacturing system. First, the current state of the art related to the ageing workforce in production systems is presented. This is structured according to four main topics: (1) analysis and evaluation of ageing workers’ functional capacities, (2) consideration of ageing workers’ capacities in industrial system modelling and management, (3) analysis and exploitation of ageing workers’ expertise, (4) acknowledgement, analysis, design and integration of supporting technologies. Next, the discussion on the impact of the ageing workforce on manufacturing systems’ performances leads to the comparison of some technological advances that are related to the Industry 4.0 paradigms. Finally, a future research agenda on this topic is proposed, based on the same topics classification proposed for the literature analysis. Five different research areas are derived, suggesting future directions for appropriate research concerning the employ of older workers in production environments.     

低温液体汽化充装系统事故原因及预防措施

分析了目前低温液体充装系统发生事故的原因 ,指出根据汽化器出口温度、压力报警与泵电机联锁设计及泵的排量、汽化器、汽化量、充瓶数之间的关系设计 ,是保证充装系统安全的有效措施。     

Determination of Trace Level Iodine in Biological and Botanical Reference Materials by Isotope Dilution Mass Spectrometry

A method has been developed for the determination of trace level iodine in biological and botanical materials. The method consists of spiking a sample with ¹²⁹I, equilibration of the spike with the natural iodine, wet ashing under carefully controlled conditions, and separation of the iodine by co-precipitation with silver chloride. Measurement of the ¹²⁹I/¹²⁷I ratio is accomplished by negative thermal ionization mass spectrometry using LaB₆ for ionization enhancement. The application of the method to the certification of trace iodine in two Standard Reference Materials is described.     

Application of socio-technical systems models to Martian colonisation and society build

Abstract

The human desire for exploration, together with an increasingly demanding potential need for establishing a human colony away from Earth has stimulated the concept and early planning for Mars colonisation. Successful delivery of such a challenging and expensive technological feat requires a highly informed and supportive general society. Although the ergonomic constraints on astronauts living and working in space is well documented, no study has employed the use of ergonomics tools to explore colony and societal build on other worlds. We have employed Cognitive Work Analysis to derive an abstraction hierarchy for both colony establishment and maintenance with the vision of building a new Martian society. We find that our model will accommodate five major challenge themes collected from over 800 members from twenty two United Kingdom - based astronomical societies and scientific groups and propose that this study may have utility in guiding mission planners in the early colonisation phase and later stage expansion processes. Using the proposed architecture for the Mars One mission, we have performed a basic human factors analysis and propose a number of key design features which may enable long term habitation.     

原子钟相位与频率估计的误差特性

本文讨论了原子钟内部的3种噪声即白色调相噪声，白色调频噪声和随机游走调频噪声对相位和频率估计的影响，分析表明，这3种噪声对相位估计和频率估计的影响完全不同，在相位估计中，选择适当的平滑长度和取样间隔可以控制估计误差，而在频率估计中，估计精度不能通过[估计器或测量设备的改进而任意提高，存在一个极限，这个极限由原子钟的内部噪声来决定。     

Analysis and optimization of weakly coupled thermoelastoplastic systems with applications to weldment design

A systematic approach for the design of weakly coupled thermoelastoplastic systems is presented. The Newton–Raphson iteration method is used in the solution process so that analytic design sensitivity formulations may be efficiently derived via the direct differentiation technique. The derived formulations are suitable for finite element implementations. Analysis and sensitivity analysis capabilities are combined with numerical optimization to form an optimum design algorithm. To demonstrate the algorithm, we optimally design a weldment with respect to manufacturing and service life aspects.