Advanced Materials Research Vols. 314-316

Abstract: Manufacturing of ship piping systems is one of the major production activities in shipbuilding. The schedule of pipe production has an important impact on the master schedule of shipbuilding. In this research, the ITOC concept was introduced to solve the scheduling problems of a piping jobshop, and an intelligent scheduling system was developed. The system, in which a product model, an operation model, a factory model, and a knowledge database of piping production were integrated, automated the planning process and production scheduling. Details of the above points were discussed. Moreover, an application of the system in a piping factory, which achieved a higher level of performance as measured by tardiness, lead time, and inventory was demonstrated.

Abstract: Since most traditional manufacturing cell design methods and some involved algorithms developed in the past few years always investigate the selection and arrangement of equipment during the design process, this paper describes a new methodology focusing on optimizing the service rates of the manufacturing cell under developing. At first, the expected cost model based on queuing theory of each process in a manufacturing cell is developed and then the optimal service rates of the equipment that make the cost the least could be obtained. Next, the designer can choose the facilities according to these parameters to configure a new manufacturing cell whose total expected cost is optimal. Finally, a numerical example is used to illustrate the advantage and validity of the new design method.

Abstract: The complexity of transportation services expands to a service-oriented transportation framework. Generally, transportation vehicles often return as deadheads after they complete their linehauls, utilizing only 50 % of the transportation capacity. Backhaul is a strategy used by freight forwarders that offers shipping to different customers while increasing profits on return trips. Through the dispatching of joint service platform, this study can use GPS and portable mobile devices, geographic information systems, and on-board unit. The idea of backhauls was utilized to maximize transportation efficiency.

Abstract: To ensure the security and integrity of three dimensional point clouds model during transmission in the network, according to their own characteristics, after the pretreatment of PCA (Primary Component Analysis), three dimensional point clouds watermarking embedding algorithm based on sphere degenerated octree was proposed, and the octree that contained the original point clouds model was subdivided multilevel from top to bottom, and the nodes of the octree were ordered. And three dimensional point clouds watermarking extraction algorithm was proposed, and the original point clouds model and the watermarked model were registered accurately, and the occurrence of synchronization error was avoided. Experimental results showed that the presented algorithm was robust to many attacks such as rotation, translation, uniform scaling, vertices reordering, simplifying, noise and cropping under blind detection.

Abstract: Discrete machine manufacture enterprises have to induce new low-carbon manufacturing model in order to solve a dilemma of mutual restraint between development and electric energy consumption. The paper presents an approach to solve JSP with the objective of minimizing the energy consumption by shortening the distance between electricity peak and valley according to theory of load shifting in electricity. The mathematical model is proposed for JSP with objective of minimizing the energy consumption and processing time of entire batch, then the idea of time division is introduced, and a solving method based on GA built-in eM-Plant is employed to verify the model and get satisfactory scheduling results.Discrete machine manufacture enterprises have to induce new low-carbon manufacturing model in order to solve a dilemma of mutual restraint between development and electric energy consumption. The paper presents an approach to solve JSP with the objective of minimizing the energy consumption by shortening the distance between electricity peak and valley according to theory of load shifting in electricity. The mathematical model is proposed for JSP with objective of minimizing the energy consumption and processing time of entire batch, then the idea of time division is introduced, and a solving method based on GA built-in eM-Plant is employed to verify the model and get satisfactory scheduling results.

Abstract: Based on a background to the mould job shop, this paper considers a two-stage flexible flow shop scheduling problem subject to release dates, where the first stage is made up of unrelated machines and tasks have group constraint. The objective is to find a schedule that minimizes makespan in that flexible flow shop environment. For this problem, a mathematic model is formulated. Because this problem is NP-hard, an improved Palmer-based heuristic (denoted by MPL) is proposed. Based on MPL, a new heuristic (denoted by IMPL) is developed. In order to test the efficiency of the two heuristics, sets of examples are designed. Compared to the MPL, the performance of IMPL is more superior.

Abstract: Heavy-duty NC machine tool is difficult and costly to evidently improve their precision via manufacturing technology only. It is proved being an effective approach to improve machine tool manufacturing precision based on software error compensation. In this paper, an error compensation algorithm based on reconstructing NC program is discussed. Following comprehensive discussion on basic algorithm of positioning error compensation in detail, linear interpolation and circular interpolation movement error compensation algorithm are further sketched in brief. To decrease the machining error, NC program is reconstructed before actual machining. The experiment results show that error compensation methods based on reconstructing NC program can improve profile accuracy of heavy-duty NC machine tools obviously.

Abstract: In order to set up a new effective method for measuring mechanical properties of the wood-plastics structural plates with stiffener, three different nondestructive testing (NDT) methods were used on the specimens with stiffener, which were made of virgin high-density polyethylene (HDPE) with poplar fibers as filler. The values of dynamic Young’s modulus of the specimens were measured by a FFT system. And the values of static bending modulus of elasticity (MOE) were also determined by three point bending test according to ASTM D790-03. The paper analyzed the variability of the dynamic Young’s modulus of specimens with stiffener obtained with different NDT methods, and the correlativity was also estimated between the dynamic Young’s modulus and the static MOE of all specimens. The results suggested that the intensity of the wood-plastics structural plates could be enhanced by stiffener, and the NDT methods could be appropriate to estimate the dynamic Young’s modulus of the wood-plastics structural plates with stiffener.

Abstract: In this paper the model of a double wishbone independent suspension was established by using ADAMS\view as an analysis platform and the kinematics simulation was performed by way of parametric modeling. By analyzing the dimension parameters of suspension, i.e. the method of DOE (Design of Experiments) supplied by the software, the parameters which were the most important influence of the sideways displacement of wheel had been ascertained: Kingpin length, kingpin Inclination and caster angle. Ultimately the key parameters were optimized with the optimal object of minimizing the absolute value of sideways displacement, and the final test results met design requirements.

Abstract: The suffocation technology of cross linked polystyrene (PS) spheres with bigger particle size was studied. The influence of swelling agent dichlorethane, swelling time, reacting temperature, constant temperature time, cooling dilution time for delivered particle on the suffocation effect was discussed. The chemical structure of suffocated PS was characterized with Fourier transform infrared spectra, and the important technical parameters of ionic exchange resin with bigger particle size were testing. The optimum suffocated condition obtained was that the feed ratio of PS particle and swelling agent was 1:0.45, swelling time was 2.5 h, and suffocation reaction was carried out for 8 h at 75oC, 20 h at 85 oC, and 15 h at 100 oC, respectively. Moreover, cooling dilution time for delivered particle was 25 h. The important technical parameters of ionic exchange resin with bigger particle size obtained with optimum suffocation condition were that mass exchange capacity was 4.57 mm/g (dry), volume exchange capacity was 2.35 mm/g (dry), and specific area was 29.5 m²/g.