Experimental evaluation of anti-stripping additives on porous asphalt mixtures

The open structure of porous asphalt mix influences its strength and durability against air, water and clogging materials. These factors cause loss of adhesion between binder-aggregate interface and loss of cohesion within the binder film. This could lead to stripping problem which contribute to premature failures as well as deterioration in the performance and service life of porous asphalt. Therefore, this study is aimed to evaluate the potential of diatomite as anti-stripping additives in porous asphalt and compared with hydrated lime and Ordinary Portland Cement (OPC). Field Emission Scanning Electron Microscopy (SEM) test and Energy Dispersive X-ray Spectroscopy analysis (EDX) were conducted to investigate the microstructure and chemical composition of the anti-stripping additives. A number of gyratory compacted samples of porous asphalt mixture with Malaysian gradation were prepared. Each sample was incorporated with 2% of anti-stripping additives as filler then mixed with polymer modified bitumen of PG76. The samples were measured for air voids content, permeability rate, resilient modulus and abrasion loss. The results indicate that samples prepared with hydrated lime show higher permeability rate and lower abrasion loss compared to samples with OPC and diatomite. However, the samples prepared with diatomite show enhanced resilient modulus compared to those with hydrated lime and OPC

A Business Process Management System based on a General Optimium Criterion

Business Process Management Systems (BPMS) provide a broad range of facilities to manage operational business processes. These systems should provide support for the complete Business Process Management (BPM) life-cycle (16): (re)design, configuration, execution, control, and diagnosis of processes. BPMS can be seen as successors of Workflow Management (WFM) systems. However, already in the seventies people were working on office automation systems which are comparable with today’s WFM systems. Recently, WFM vendors started to position their systems as BPMS. Our paper’s goal is a proposal for a Tasks-to-Workstations Assignment Algorithm (TWAA) for assembly lines which is a special implementation of a stochastic descent technique, in the context of BPMS, especially at the control level. Both cases, single and mixed-model, are treated. For a family of product models having the same generic structure, the mixed-model assignment problem can be formulated through an equivalent single-model problem. A general optimum criterion is considered. As the assembly line balancing, this kind of optimisation problem leads to a graph partitioning problem meeting precedence and feasibility constraints. The proposed definition for the "neighbourhood" function involves an efficient way for treating the partition and precedence constraints. Moreover, the Stochastic Descent Technique (SDT) allows an implicit treatment of the feasibility constraint. The proposed algorithm converges with probability 1 to an optimal solution.BPMS, control assembly system, stochastic optimisation techniques, TWAA, SDT

Solving Assembly Line Balancing Problems by Combining IP and CP

Assembly line balancing problems consist in partitioning the work necessary to assemble a number of products among different stations of an assembly line. We present a hybrid approach for solving such problems, which combines constraint programming and integer programming.Comment: 10 pages, Sixth Annual Workshop of the ERCIM Working Group on Constraints, Prague, June 200

Multi-objective discrete particle swarm optimisation algorithm for integrated assembly sequence planning and assembly line balancing

In assembly optimisation, assembly sequence planning and assembly line balancing have been extensively studied because both activities are directly linked with assembly efficiency that influences the final assembly costs. Both activities are categorised as NP-hard and usually performed separately. Assembly sequence planning and assembly line balancing optimisation presents a good opportunity to be integrated, considering the benefits such as larger search space that leads to better solution quality, reduces error rate in planning and speeds up time-to-market for a product. In order to optimise an integrated assembly sequence planning and assembly line balancing, this work proposes a multi-objective discrete particle swarm optimisation algorithm that used discrete procedures to update its position and velocity in finding Pareto optimal solution. A computational experiment with 51 test problems at different difficulty levels was used to test the multi-objective discrete particle swarm optimisation performance compared with the existing algorithms. A statistical test of the algorithm performance indicates that the proposed multi-objective discrete particle swarm optimisation algorithm presents significant improvement in terms of the quality of the solution set towards the Pareto optimal set

Henry Ford vs. assembly line balancing

Ford’s Assembly Line at Highland Park is one of the most influential conceptualizations of a production system. New data reveal Ford’s operations were adaptable to strongly increasing and highly variable demand. These analyses show Ford’s assembly line was used differently than modern ones and their production systems were more flexible than previously recognized. Assembly line balancing theory largely ignores earlier practice. It will be shown that Ford used multiple lines flexibly to cope with large monthly variations in sales. Although a line may be optimized to yield lowest cost production, systems composed of several parallel lines may yield low cost production along with output and product flexibility. Recent research on multiple parallel lines has focussed on cost effectiveness without appreciating the flexibility such systems may allow. Given the current strategic importance of flexibility it should be included in such analyses as an explicit objective

Workforce management in manual assembly lines of large products: a case study

Assembly lines are used for a large variety of products in different industrial sectors. In this paper the focus is placed on complex assembly systems and workstations used for the final assembly of large and bulk products, such as trucks, aircrafts, buses, tool machines. An high number of tasks to be performed at a single assembly station, several workers involved in parallel in the assembly process and long Takt times make such systems different from the models intensively studied in the literature (e.g. the traditional Simple Assembly Line Balancing Problem). This study firstly presents a new balancing model to address the problem of the total cost minimization when different operator skills are involved at the same time and then it applies the model to a real industrial case

Performance analysis of SWOT suite toolkit on Inter-domain and Intra-domain Web of Things

The Web of Things (WoT) is a term used to describe approaches, software architectural styles and programming patterns that allow real-world objects to be part of the World Wide Web [1]. Similarly to what the Web (Application Layer) is to the Internet (Network Layer), the Web of Things provides an Application Layer that simplifies the creation of Internet of Things applications [2]

Tahap penggunaan pembelajaran maya dalam kalangan guru reka bentuk teknologi: satu tinjauan di sekolah rendah luar bandar

Sejajar dengan matlamat anjakan ketujuh dalam Pelan Pembangunan Pendidikan Malaysia (2013-2025) iaitu untuk mentransformasikan sistem pendidikan negara, kerajaan telah menyediakan akses internet dan persekitaran pembelajaran maya melalui 1BestariNet di 10,000 sekolah seluruh Malaysia termasuk sekolah-sekolah luar bandar. Pembelajaran Maya (Virtual Learning Environment - VLE) merupakan platform pembelajaran yang menjadi agenda utama terutamanya di sekolah rendah. Secara spesifiknya, platform VLE Frog telah digunakan dalam kalangan guru dan pelajar sekolah rendah. Sehubungan itu, kajian berbentuk tinjauan ini dijalankan untuk mengkaji tahap penggunaan VLE Frog dalam aktiviti Pengajaran dan Pembelajaan (PdP) bagi subjek Reka Bentuk Teknologi (RBT) di sekolah rendah luar bandar. Selain itu, kajian ini juga bertujuan untuk mengkaji masalah utama yang dihadapi oleh guru-guru yang menggunakan VLE Frog di dalam aktiviti PdP. Responden yang terlibat dalam kajian ini adalah seramai 36 guru yang mengajar mata pelajaran RBT di 18 buah sekolah rendah luar bandar di daerah Batu Pahat. Borang soal selidik digunakan sebagai instrumen untuk proses pengumpulan data. Hasil kajian menunjukkan bahawa tahap penggunaan VLE Frog dalam kalang guru yang mengajar mata pelajaran RBT di sekolah luar bandar di Daerah Batu Pahat adalah serdehana. Selain itu, kajian ini juga mengunjukkan bahawa capaian internet merupakan masalah utama yang dihadapi oleh guru RBT semasa menggunakan VLE Frog di sekolah