LED luminance measurement and development of low-cost computerized perimeter

An accurate method has been developed to calculate and measure the luminance of light-emitting diode （LED）. A novel, simple-structured and high-precision circuitry was designed, which has been applied to the development of a low-cost threshold static automated perimeter. Round LEDs of 2 mm in diameter were used as stimuli. A logarithmic scale is used to express the differential light sensitivity, where 0 dB represents the brightest stimulus that corresponds to 1 000 asb. The LED radiant power was measured and its equivalent luminance was calculated by the derived equations. The schematics of the system is given, together with a novel circuitry for selecting stimulus point and its luminance. Initial clinical trial results were promising,which led to a further development of a commercial product.     

LXI instrument development platform based on an open embedded operating system

This paper introduces the architecture and components of LXI instrument development platform based on an open embedded operating system,which is a modular and configurable platform.The platform is a total solution to develop LXI instrument modules and systems.On the other hand,it also supports other types of instrument development.This is a generic and efficient platform.At the end,this paper addresses the technical tends, challenges,and recormnends solutions.     

The development of vacuum measurements down to extremely high vacuum – XHV

The available measuring devices in the ultra-high and extreme high vacuum range with their limitations are presented on the basis of the ultimate attainable pressure. New miniature gauges and calibration devices up now available are shortly reviewed. A complete bibliography is presented.     

Digital manufacturing—the development direction of the manufacturing technology in the 21st century

After introducing the concepts of digital manufacturing technology, the discipline framework of digital manufacturing is presented in the paper by discussing its basic concept, theory foundation, key technology and scientific problems in detail. As the core of the advanced manufacturing technology, digital manufacturing is gradually becoming the main manufacturing technology of the twenty-first century. Firstly, the main features of digital manufacturing are indicated and its key supporting technologies are investigated by grouping them into four levels related to product development, numerical control, production management, and enterprise collaboration, respectively. Moreover, the existing problems in the research on the multi-discipline theory foundation of digital manufacturing such as manufacturing informatics, computational manufacturing, and manufacturing intelligence, are also indicated. Then, the core scientific problems of digital manufacturing are discussed in depth, which focuses on digitization of manufacturing information, modeling of manufacturing constraints, high-speed and high-precision numerical control theory, and Internet-based collaboration and integration. Lastly, the development trends and application perspectives of digital manufacturing are concluded.     

Industrial culture and its implication for a development concept for a “culture of manufacturing”

A great challenge for mankind is to shape the dynamic tension and relationship between the emergence of global structures and regional structures, to encourage productive cooperation. The science of cognitive anthropology provides an interdisciplinary approach to this problem by a combination of cognitive science, cultural anthropology, occupational science and engineering science.Industrialised countries usually have a tradition of handicraft production which forms a basis for the acquisition of the skills of technological development and transfer. Technological development can be considered as a cyclic process in which the diverging elements of the regional industrial culture, and the converging elements of the global industrial society are dynamically related. In the initial stages of design and development, cultural elements tend to dominate, in the later stages socio-industrial forces become more effective, transforming the initial divergent phase into a convergent one. The traditional approach to product development is considered and its deficiencies in relation to the development of complex organizational structures are outlined. The paper concludes that the concept of culture of manufacture can only be developed by an interdisciplinary approach and if academic knowledge and the specific abilities and approach of appliers and users are integrated into the technology shaping process.     

Cost model development using virtual manufacturing and data mining: part II—comparison of data mining algorithms

Cost models of manufacturing processes are an important tool enabling enterprises to make reasonable predictions and forecasts in relation to the production costs for existing and new products. Accurate and robust cost models can help to provide significant competitive advantage for manufacturing organisations. Advanced computational methods such as virtual manufacturing and data mining have been identified as potentially powerful techniques for generating cost models that bypass the problems associated with traditional cost modelling processes. Part I, of this two-part paper, described the development of a cost model development methodology that makes use of virtual manufacturing models and data mining techniques and used case study data to validate this methodology. A critical part of this methodology is the selection and use of effective data analysis techniques that can identify accurate and robust cost estimating relationships. Part II now examines in detail the effectiveness of alternative data mining algorithms in terms of their ability to develop relationships that are (1) representative of the real causal relationships that exist and (2) able to provide a high level of estimating accuracy. More specifically, it focuses on the data generated by virtual manufacturing models and how the size and complexity of the generated data sets impact the accuracy of the cost estimating relationships.     

Wear development on wiper Al2O3–TiC mixed ceramic tools in hard machining of high strength steel

This paper explores the wear mechanisms occurring for the mixed ceramic inserts against 60 HRC alloy steel (equivalent to AISI 5140 or DIN 41Cr4) specimens in dry and hard finish turning operations. Several machining wear tests were performed under varying feed rate, constant cutting speed of 100 m/min and small depth of cut of 0.2 mm. Light optical microscopy (LOM), scanning electron microscopy (SEM) and back-scattering electron (BSE) technique were employed to observe morphological features of worn surfaces produced by various wear mechanisms. In addition, the elemental compositions of wear products were evaluated by energy-dispersive X-ray (EDX) micro-analysis, called sometimes energy-dispersive X-ray spectroscopy (EDS). As a result, both microscopic and microstructural aspects of ceramic tool wear were considered. In general, wear mechanisms identified in the machining tests involve abrasion, fracture, plastic flow and transferred layers, BUE and tribochemical effects. Specific wear symptoms appeared depending on the mechanical and thermal conditions generated in the wear zones. In particular, two types of material transfer with different morphologies occurring at the rake–chip interface are distinguished.     

FPGA based chip emulation system for test development of analog and mixed signal circuits: A case study of DC–DC buck converter

Prototyping on FPGA has become a main stream verification methodology for hardware design, test development, software co-design, etc. in the area of digital VLSI. In the case of test development, FPGA serves as a virtual DUT (Design Under Test) and test patters are applied from automatic test equipment (ATE). This verifies not only the chip with design for test (DFT) circuitry and test program but also the entire test setup involving virtual DUT, load board, interconnections with ATE, etc. Although, FPGA based platform is used widely for test program verification of digital ICs, this technique is not used for analog/mixed signal (AMS) circuits because of the difficulty in implementing AMS circuits in FPGAs. This work is concerned with the development of a test emulation platform, termed as hand-in-hand test flow, of AMS circuits based on FPGA. The proposed methodology exploits fixed-point modeling and DSP implementation techniques facilitated by latest FPGAs to model the AMS circuits. The proposed hand-in-hand test flow for AMS circuits will help the test engineers to start their test plan concurrently with the design engineers and validate them much prior to the first silicon. We have illustrated the proposed scheme using the case study of a current programmed buck type switching converter on Xilinx® Virtex™-5 FPGA. The FPGA emulation measurement results show that performance of the emulated DC–DC buck converter (e.g., duty ratio test, line transient, load step) matches well with that of SPICE simulation.