The strategic role of recycling centres for environmental performance of waste management systems

This paper analyses how different actors influence the sorting quality of waste at recycling centres. Users (i.e. citizens) play an essential role since they conduct the actual sorting. They have difficulties sorting many of their discarded products, leading to decreased performance of the entire waste management system of which recycling centres are a part. Several measures addressing this problem are identified such as product design, improved terminology for labelling waste and increased manning at recycling centres. A fundamental task for managers and employees is to further develop information and guidance for users, both at home and at recycling centres. Several obstacles for improvements are also discussed, including working conditions and the economy of recycling centres, as well as the routines for communication and quality assurance among actors in the recycling business.     

Vision ergonomics at recycling centres

All municipalities in Sweden offer their inhabitants a service for disposing of large-size and hazardous waste at local recycling centres. Opening hours at these centres include hours of darkness. The aims of this study were to 1) describe user and employee experiences of lighting and signs at Swedish recycling centres, 2) measure and assess the lighting system at the two recently built recycling centres in Linköping and to assess the legibility and visibility of the signs used and 3) propose recommendations regarding lighting and signs for recycling centres. Interviews and questionnaires were used to assess experiences of employees and users, and light measurements were performed. By observing users, activities with different visual demands at different areas within the recycling centres were identified. Based on the literature, standards and stakeholder experiences, recommendations regarding lighting systems and sign design, illuminance, luminance and uniformity are proposed for recycling centres.     

Working conditions at recycling centres in Sweden - Physical and psychosocial work environment

The number of jobs at recycling centres are increasing, at the same time as there are indications of work environment problems. The aim of this paper was to investigate physical and psychosocial working conditions for employees at recycling centres in Sweden, to describe how they were perceived, to compare differences between subgroups, and further to identify proposals for improvement. Employees at 42 recycling centres (n = 122) responded a postal questionnaire. Of these 32 employees from 16 recycling centres were interviewed, as also their employer (n = 16).The work at recycling centres was reported to be a meaningful service job comprising many social interactions with users, but also substantial physical strain. There was a high frequency of injuries and minor injuries. Several risks were identified. There is a need for several preventive actions, e.g. better planning when building recycling centres, including better machines and equipment and more training, especially in handling hazardous waste.     

Information centres: marketing ploy and practical answer to DP backlogs

Information centres are supposed to provide users with their own bypass to the application backlog. This paper looks at how the concept of information centres has been taken up by users, and at how other mainframe manufacturers are reacting to what was a shrewd initial marketing ploy by IBM. Burroughs however has eschewed the information centre approach.     

多模态深度神经网络的固废对象分割

目的 对城市发展过程中产生的建筑固废进行处理,并将之转换为资源和能源,是极佳的保护环境的经济发展模式。然而人工分拣处理存在效率低、污染严重、对人身危害大等问题。目前工业界在探索一种有效的基于机械臂自动抓取的建筑固废自动分拣系统,其中图像分割技术是非常必要的一个环节。但是工业现场的环境因素造成固废对象的颜色严重退化,会影响最终的固废对象分割。本文针对建筑固废图像分割难度大的现状,提出一种基于多模态深度神经网络的方法来解决固废对象分割问题。方法 首先, 在颜色退化严重的场景下,把RGB图像和深度图一起作为深度卷积神经网络的输入,利用深度卷积神经网络进行高维特征学习,通过softmax分类器获得每个像素的标签分配概率。其次,基于新的能量函数建立全连接条件随机场,通过最小化能量函数寻找全局最优解来分割图像,从而为每一类固废对象产生一个独立的分割块。最后,利用局部轮廓信息计算深度梯度,实现同一类别的不同实例的固废对象精确分割。结果 在固废图像测试集上,该方法取得了90.02%均像素精度和89.03%均交并比（MIOU）。此外,与目前一些优秀的语义分割算法相比,也表现出了优越性。结论 本文方法能够对每一个固废对象同时进行有效的分割和分类,为建筑垃圾自动分拣系统提供准确的固废对象轮廓和类别信息,从而方便实现机械臂的自动抓取。     

Reported occupational injuries at Swedish recycling centres - based on official statistics

Swedish recycling centres are manned facilities for waste collection. There is no special category in the official injury statistics for employees at recycling centres, which precludes a straightforward analysis of reported occupational injuries. This study aimed at identifying the frequency of reported accidents and diseases and the type of events that contribute to such injuries at recycling centres, based on official injury statistics. The employees were identified as being affected by more than three to five times as many accidents compared with the total workforce in Sweden. The reported accidents had occurred during a wide range of situations, but most frequently during manual handling of waste. Reported work-related diseases were mostly associated with musculoskeletal disorders, mainly due to heavy lifting. A more detailed classification of sanitation professions and workplaces in the official injury statistics would facilitate future studies of injuries in a specific professional category, e.g. employees at recycling centres. Suggestions for prevention are given. STATEMENT OF RELEVANCE: The present article describes all reported work accidents and diseases among employees at recycling centres from 1992 to February 2005. It also highlights the problem of identifying new working groups in the official statistics and gives advice for a detailed classification to facilitate such future studies of injuries.     

用于智能垃圾分拣的注意力YOLOv4算法

针对人工垃圾分拣效率低、工作环境恶劣且成本高的问题,提出了一套智能可回收垃圾分拣系统,该系统采用RGB图像作为视觉信息输入,通过目标检测算法获取垃圾在传送带上的位置坐标信息,并通过机械臂对垃圾进行分拣操作。可回收垃圾形态各异、种类繁多,为提高检测算法的泛化能力,建立了一个含36 572帧图片的可回收垃圾数据集,并基于此数据集上训练目标检测算法。基于YOLOv4提出了嵌入注意力机制的目标检测算法Attn-YOLOv4,经实验验证,Attn-YOLOv4算法的mAP比原始YOLOv4算法高0.16个百分点。在静态识别功能的基础上,提出基于多线程的目标跟踪算法实现了对运动垃圾的快速稳定跟踪,在20 mm误差范围内达到了0.945的精确度。此外,后处理模块对图像进行形态学处理并获取垃圾的世界坐标以及放置角度,供机械臂进行分拣操作。分别对目标检测和跟踪算法进行验证,在实际分拣流水线上验证并评估了该智能可回收垃圾分拣系统的可行性、精度及分拣的成功率。     

Planning the structure of the parcel flow in a postal logistics system

This article describes a computerized simulation model that makes it possible to compare alternative centre structures for the parcel flow in a postal logistics system. The main elements of a logistics system are presented in the introduction. The parcels are subject to two major activities, transportation and sorting. Concentrating sorting activities in a few sorting centres gives large scale advantages. But on the other hand transportation costs are augmented because parcels will make a detour before reaching their destination. Given an initial centre structure, i.e. number and location of potential sorting centres, the simulation model makes use of a heuristic procedure to determine the principle of processing for each individual parcel, i.e. central or decentrai sorting. The calculations are based on a mathematical model as described in section 2. The model comprises physical characteristics, costs and goals for service levels. The heuristic principle of the model is described in section 3. The heuristic procedure starts with an initial solution for transportation and sorting that is ameliorated step by step using different saving criteria for sub-optimization of parts of the model. Finally section 4 presents the application of the simulation model.     

DNA computer based algorithm for recyclable waste paper segregation

This article explores the application of DNA computing in recyclable waste paper sorting. The primary challenge in paper recycling is to obtain raw materials with the highest purity. In recycling, waste papers are segregated according to their various grades, and these are subjected to different recycling processes. Highly sorted paper streams facilitate high quality end products, while saving on processing chemicals and energy. In the industry, different sensors are used in paper sorting systems, namely, ultrasonic, lignin, gloss, stiffness, infra-red, mid-infra red, and color sensors. Different mechanical and optical paper sorting systems have been developed based on the different sensors. However, due to inadequate throughput and some major drawbacks related to mechanical paper sorting systems, the popularity of optical paper sorting systems has increased. The automated paper sorting systems offer significant advantages over the manual systems in terms of human fatigue, throughput, speed, and accuracy. This research has two objectives: (1) to use a web camera as an image sensor for the vision system in lieu of different sensors; and (2) to develop a new DNA computing algorithm based on the theme of template matching techniques for segregating recyclable waste papers according to paper grades. Using the concepts of replication and massive parallelism operations, the DNA computing algorithm can efficiently reduce the computational time of the template matching method. This is the main strength of the DNA computing algorithm in actual inspections. The algorithm is implemented by using a silicon-based computer to verify the success rate in paper grade identification.     

Network management for automated banking

The Postipankki Bank in Finland has installed a network monitoring and control system to keep watch on the network linking its central data centre and six remote processing centres; in total, a configuration of 2000 terminals. The criteria on which the network was selected are discussed, and the improvements obtained in availability of information on network utilization and fault monitoring are described.     

Secure Information Access Strategy for a Virtual Data Centre

With the arrival of on-demand computing, data centre requirements are extensive, with fluid boundaries. Loaded Internet applications, service-oriented architectures, virtualization and security provisioning are the major operations of a data centre. Security is an absolute necessity of any network architecture, and the virtual IT data centre is no exception. At the boundary, security is focused on securing the terminals of the data centre from external threats and providing a secure gateway to the Internet. The paradigm shift towards a new computing environment makes communications more complicated for Infrastructure Providers (InP). This complexity includes the security of the data centre’s components to protect data from malicious attacks or from being compromised. Threats/attacks are inevitable if the data are generated from a public network, such as Wi-Fi in an Airport, Railway station and other public places. Since these places create enormous amounts of data from anonymous and naive users, it is essential to store the information in a data centre. In this article, we propose an efficient, secure, and privacy-preservation information access algorithm to access data centres in public wifi networks. This algorithm is based on the primitive root approach for sending and receiving credentials through the anonymous authentication of the users and ensuring protected data access from the data centre. Security and Performance Analysis and its evaluation prove that our approach is successful with respect to security, privacy preservation and computational complexity.     

An ant colony algorithm for the multi-compartment vehicle routing problem

We demonstrate the use of Ant Colony System (ACS) to solve the capacitated vehicle routing problem associated with collection of recycling waste from households, treated as nodes in a spatial network. For networks where the nodes are concentrated in separate clusters, the use of k-means clustering can greatly improve the efficiency of the solution. The ACS algorithm is extended to model the use of multi-compartment vehicles with kerbside sorting of waste into separate compartments for glass, paper, etc. The algorithm produces high-quality solutions for two-compartment test problems.     

Joint investigation of working conditions, environmental and system performance at recycling centres - Development of instruments and their usage

Recycling is a new and developing industry, which has only been researched to a limited extent. This article describes the development and use of instruments for data collection within a multidisciplinary research programme “Recycling centres in Sweden - working conditions, environmental and system performance”. The overall purpose of the programme was to form a basis for improving the function of recycling centres with respect to these three perspectives and the disciplines of: ergonomics, safety, external environment, and production systems. A total of 10 instruments were developed for collecting data from employees, managers and visitors at recycling centres, including one instrument for observing visitors. Validation tests were performed in several steps. This, along with the quality of the collected data, and experience from the data collection, showed that the instruments and methodology used were valid and suitable for their purpose.     

RFID-based wireless manufacturing for walking-worker assembly islands with fixed-position layouts

A walking-worker fixed-position flexible assembly line is a shop-floor where products are placed at work centres, the workers move from one work centre to another, and tools and components are brought to the work centre for assembly according to the process and production plan. Such assembly shop-floor configuration is not only suitable for producing large, bulky, heavy or fragile products, but also offers necessary flexibility and competitive operational efficiency for products of modest variety and production volumes. However, the shop-floor with a fixed-position assembly islands typically suffers from limited spaces at work centres and high dynamics of material and manpower flows in addition to common shop-floor problems. This paper presents an affordable solution to these problems by using wireless manufacturing (WM)–an emerging advanced manufacturing technology (AMT). WM relies substantially on wireless devices such as radio frequency identification(RFID) auto ID sensors and wireless information networks for the collection and synchronization of the real-time field data from manufacturing workshops. A simplified example is used to illustrate how to deploy WM technology for implementing the concept of Just-In-Time (JIT) manufacturing to reduce the shop-floor work-in-progress (WIP) inventories and smoothening their flows through real-time information visibility and traceability.     

Product from solutions for multiserver centres with concurrent classes of customers

The MultiServer centre with Concurrent Classes of Customers (MSCCC) is a service centre consisting of B parallel identical exponential servers. The customers requesting service at the MSCCC centre belong to K groups. Customers arriving at the MSCCC centre are queued in the order of their arrival. A customer from group k will go into service at the MSCCC centre provided that one or more of the B servers is free and that at most n − 1 other group k customers are in service at the MSCCC centre.

The MSCCC centre can be applied to model systems where customers simultaneously occupy two resources. The system resources are partitioned into K primary and B secondary resources. A customer of group k can access primary resource k if it already is in possession of a secondary resource and if at most n − 1 other group k customers are using primary resource k.

This paper defines the MSCCC centre and presents several examples of computer (sub)systems that can be modelled using the MSCCC centre. The MSCCC centre is shown to satisfy local balance: therefore a multiclass queuing network consisting of BCMP and MSCCC centres has a product form solution. The joint probability distribution (JPD) for a queuing network consisting of several BCMP centres and one MSCCC centre is derived. Aggregation techniques are next used to reduce the JPD to a computationally tractable form. A Mean Value Analysis algorithm is presented for calculating the closed and open chain performance measures at the MSCCC centre.     

基于改进FoveaBox的废杂塑料检测

塑料制品的产量和种类的飞速增长，给废杂塑料的回收带来极大的挑战；目前仍然依靠大量人工分拣，面对恶劣和高强度的工作环境无疑亟待自动化升级；为解决上述问题，提出了一种改进的FoveaBox目标检测算法；针对废杂塑料分选背景复杂的问题，采用ResNeXt-101作为主干网络替代ResNet-50来提高特征提取能力；针对外形差异大的问题，采用带缩放系数的可变形卷积来提高卷积过程的有效感受野；针对目标间彼此遮挡问题，采用带层级控制因子的软化加权锚点机制来提高紧挨目标的检测精度；结果表明，基于改进FoveaBox的废杂塑料检测算法检测平均精度均值达到85.79%，检测速度为71.4ms，具有较强的实用性。     

The construction of a collaborative-design platform to support waste electrical and electronic equipment recycling

Recycling of waste electrical and electronic equipment (WEEE) is a very important subject not only from the viewpoint of waste treatment but also from the viewpoint of recovery of valuable materials. In the past, some obstacles make recycling challenging for today's manufactured products. First, it is difficult to gain all the information necessary to plan for the recycling evaluation, as most design information is owned and kept by suppliers. Another problem in recycling end-of-life (EOL) products is a lack of technologies to handle the very complex products that are being discarded today, because the knowledge of how to do so is owned by the recycler.This research demonstrates how to support WEEE recycling analysis by environmental information with the part of bill of material. A collaborative-design platform is further constructed and collected all the needed information using computer-aided design (CAD), enterprise resource planning (ERP), and product life-cycle management (PLM) systems. Through this platform, suppliers are required to provide component information to enable the manufacturer's design for disassembly and recycling analysis. The results demonstrate that designers can obtain disassembly and recycling information through the model, so that desirable changes can be made in the early stages of a design. An industrial case study from Taiwan is also provided to demonstrate the use of this model.     

Applying a Stochastic Model to a Dynamic, QoS Enabled Web Services Hosting Environment

Data centres which host Web services for other organisations and users in a Grid environment must provide for Quality of Service (QoS) requirements to be specified to ensure deployed services perform as desired. As services hosted by a data centre receive unpredictable rates of demand, servers must be allocated dynamically to service pools that are over utilised to avoid breaking QoS requirements. This work describes how a cost based stochastic model for resource allocation is used in data centre middleware to balance server utilisation, and how the model was used to enable a data centre to meet QoS requirements. The stochastic QoS model is compared to two other QoS models and is shown to be the most effective in a number of experiments.     

Coalition-Based Resource Negotiation for Multimedia Applications in Informationally Decentralized Networks

Designing efficient and fair solutions for dividing the network resources in a distributed manner among self-interested multimedia users is recently becoming an important research topic because heterogeneous and high bandwidth multimedia applications (users), having different quality-of-service requirements, are sharing the same network. Suitable resource negotiation solutions need to explicitly consider the amount of information exchanged among the users and the computational complexity incurred by the users. In this paper, we propose decentralized solutions for resource negotiation, where multiple autonomous users self-organize into a coalition which shares the same network resources and negotiate the division of these resources by exchanging information about their requirements. We then discuss various resource sharing strategies that the users can deploy based on their exchanged information. Several of these strategies are designed to explicitly consider the utility (i.e., video quality) impact of multimedia applications. In order to quantify the utility benefit derived by exchanging different information, we define a new metric, which we refer to as the value of information. We quantify through simulations the improvements that can be achieved when various information is exchanged between users, and discuss the required complexity at the user side involved in implementing the various resource negotiation strategies.      

A SAR image method of detecting target changes using two-dimensional scattering centre characteristics

Remote-sensing image interpretations and applications require information on changes in the target. In high-resolution synthetic aperture radar (SAR) images, multi-scattering centres reflect the characteristics of target scattering, but not those of point targets or point scattering. Total scattering is the vector summation of each scattering centre. These scattering centres include shape and structural information of the target. When a target changes, both the scattering characteristics and the scattering centres change. In this way, changes in the centres may cancel out changes in the target. This article proposes a new method of change detection for SAR image targets using the two-dimensional scattering centre characteristics (TDSCC). This method is here called the TDSCC algorithm. This algorithm differs from other change detection algorithms that are based on image fields. General change detection algorithms require accurate registration. Otherwise, the change information is inaccurate. The TDSCC method is a feature-level or target-level change detection algorithm and it does not require registration operation. Therefore, it avoids errors in change information. The experimental data have confirmed the feasibility of the proposed algorithm.