Applied Mechanics and Materials Vols. 799-800

Abstract: The link power improvement in a coarse wavelength division multiplexing (CWDM) system which is transmitted using a hybrid erbium-doped fiber amplifier (EDFA) and semiconductor optical amplifier (SOA) scheme as a pre-amplifier, is discussed. The network is designed for amplifying 8 CWDM channels ranging from 1471 nm to 1611 nm. The hybrid amplifiers’ gain measurement is obtained from experimental work with gain peak at 22 dB which is observed at 1531 nm. The amplifiers also caused power increment of 5.06 dB in the transmission link before the signal is split individually at the receiving end. Based on the higher gain peaks and power spectrum at 1531 nm and 1551 nm wavelengths, the proposed amplified link would be useful for the transmission of video applications.

Abstract: In this paper, the simulation and measurement results of a filter-antenna module for application in WLAN band are presented. The filter-antenna module is fabricated on microwave ceramic substrate. The filter-antenna module is consisted of a monopole antenna, two U-shaped microstrip half wavelength resonators, and a tapped open stub. The proposed filter-antenna module has good agreement between the measurement and the simulation results. At center frequency, electromagnetic coupling between two half-wavelength resonators and inverted-L shaped microstrip feed line occurs and contributes the radiation. At the harmonic frequency, the currents are mainly distributed around the tapped open stub. The proposed filter-antenna module has a 10 dB return loss with bandwidth 290 MHz (2,337 - 2,627 MHz), covering the WLAN band.

Abstract: A broadband multi-layer radar absorbing coating (RAC) and transparent shielding film (TSF) operating within the frequency range of 7 to 12 GHz are designed and fabricated for the purpose of a radar cross section (RCS) reduction of complex naval targets such as submarines and ships. The proposed RAC consists of three layers, a shop primer, a main absorbing material, and epoxy resin paint. In addition, a TSF was fabricated by coating an ITO/Ag/ITO multilayer on a polyethylene terephthalate (PET) substrate using roll-to-roll DC plasma deposition technique. The experimental results demonstrate that the proposed RAC guarantees an RCS reduction of 10 to 15 dB from 7 to 12 GHz.

Abstract: Originally, this paper investigates the impact from free flow of 11 logistics services provider to overall equipment efficiency: OEE in beverage industrial sector in Thailand. Then, the analysis process had used factor analysis to construct factors of free flow of 11 logistics services provider and OEE; in addition, multiple regression analysis had been taken to test the impact from free flow of 11 logistics services provider to OEE. Next, the result of 78 firms show that free flow of 11 logistics services provider can be explained by one factor; OEE can be explained by two factors. Following, the study finding is free flow of 11 logistics services provider positive impact to OEE, and highly relates Availability and Performance Efficiency more than Quality Efficiency.

Abstract: This article proposes a new approach to select the location for separators and routes for two phase flow pipelines in a geothermal steam gathering system. Multiple weight distance transform is presented and used to find the optimum location of site for a steam separator based on the flow capacity of geothermal wells. The routes are monotonic and the incline is slight in order to minimize the pressure drop and the slug flow conditions in the pipeline. A map with weighted distance for five wells shows the accessible area and the route from each well is calculated. The optimum site location reduces the total pipe length from all wells by 9%.

Abstract: Overbooking is a technique which sells goods or services in excess of the available capacity because there is a possibility that some customers might not show up. In air cargo overbooking problem, overbooking model is more complex because of the two-dimensional characteristic. This paper presents a two-dimensional air cargo overbooking model to find the optimal overbooking level in order to minimize the total cost, which consists of spoilage and offloading costs. Booking requests and show-up rate are random variables with known distributions. Sensitivity analysis is used to observe the impact of the ratio between spoilage and offloading costs on the optimal overbooking level.

Abstract: This research objective is to improve the productivity of cookware assembly line by means of time and distance reductions. The motion study and line balancing techniques were applied to the entire assembly operations. A bottle neck was identified to where the operation with inadequate machine layout and workplace organization, including the unbalanced workloads. The new workplace layout and new working method for operators were designed and implemented as well as balancing the assembly line. Specifically, the conveyor speed and duration between the consecutive workpieces in the production line were adjusted to 0.10 m/s and 50 cm, respectively. The number of operators needed in the process can be reduced from 14 persons to 11 persons. The cycle time for assembling process is decreased from 12 to 5 second.

Abstract: Evaluation of service at the airport is important for the passenger satisfaction. Based on the evaluation results, the management of the airport can decide what can be done to improve the system. In this research, we have evaluated and improved the performance of the departure terminal system at Soekarno-Hatta International Airport using simulation and line balancing methods. There are several steps in the research: evaluating the performance of existing system using simulation method: optimizing the system using line balancing and simulation methods: and analysing the results of the optimization process. The results show that the performance of the optimization process can decrease passenger processing and waiting time. We conclude that line balancing and simulation methods can be utilized to optimize the system of the departure terminal at the airport.

Abstract: Increasing global competition, shrinking product life cycles, and increasing product mix are defining a new manufacturing environment in world markets. This paper presents a case problem using Taguchi Method to find optimum design parameters for a Flexible Manufacturing System (FMS). A L₈ array, signal-to-noise (S/N) ratio and analysis of variance (ANOVA) are employed to study performance characteristics of selected manufacturing system design parameters (e.g. layout, AGVs, buffers, and routings) with consideration of product mix demand. Various design and performance parameters are evaluated and compared for the original and the improved FMS. The results obtained by this method may be useful to other researchers for similar types of applications.

Abstract: This paper contains main principles of function-oriented analysis. This approach may be used to estimate the product quality from the point of view of its consumer properties. The object and its components are studied in terms of the functions they fulfill, which corresponds to the degree of satisfaction of the customer requirements (or expectations). It makes possible to find out the relation between the consumer functions and the product properties and determines the practical ways of quality improvement. It is proved that the function-oriented analysis can be used efficiently for both current metal products and for research and design of up-to-date engineering and manufacturing systems.