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High-performance two-stage bipolar cascade 905nm vertical cavity surface emitting lasers (VCSELs) are designed and fabricated. Three different designs are investigated to compare the electrical and optical properties. Experimental results show that the current spreading and thermal problems are important factors affecting the device performance. The device with two oxide apertures accompanied with a $1.5\lambda $ -long active region spacing exhibits a very high slope efficiency of 2.27W/A and a relatively high power conversion efficiency of 52.4%. Such high-performance bipolar cascade VCSELs with 905nm are very important for LiDAR and automotive applications.

Greater than 190 °C continuous wave (CW) lasing is achieved from 905 nm high-efficiency vertical cavity surface-emitting lasers (VCSELs). The maximum power conversion efficiency (PCE) of 46.3% for ${4}~\mu \text{m}$ VCSELs was demonstrated under the ambient temperature of 30 °C. The maximum PCE decreases only 10% of its value from 30 °C to 90 °C, showing stable high-temperature characteristics. The thermal resistances and active region temperatures of the device versus ambient temperature are determined experimentally. Besides, size-dependent thermal characteristics are also analyzed by characterizing the spectral and spatial properties of devices with various apertures. It is found that the higher the ambient temperature is, the less the number of high-order modes is, and single fundamental mode operation can be realized in ${4}~\mu \text{m}$ VCSELs even at a relatively high temperature of 190 °C. The design and characterization of these high-temperature VCSEL devices might present the basis for future laser radar application.

The output characteristics of vertical cavity surface emitting lasers (VCSELs) arrays are largely influenced by temperature. We systematically studied thermal properties in 20-element oxide-confined VCSEL arrays via both theory and experiment. The output power, conversion efficiency, and threshold current dependent on ambient temperatures were measured. According to the relationship of wavelength shift and dissipated power, the device thermal resistance dependent on ambient temperature was obtained. The actual temperature in active region was successfully extracted. A 3-D heat diffusion model was established to simulate temperature distribution accurately.

Implant-defined coherent vertical-cavity surface-emitting laser (VCSEL) arrays with an integrated phase shifter that can convert the out-of-phase mode into the in-phase mode were demonstrated. The measured angular full-width at half-maximum (FWHM) from a ${9} \times {9}$ coherent VCSEL array in the far-field lobes is only 0.82°. The intensity of the central lobe is about 2.9 times than that of surrounding sidelobes, showing excellent beam quality. The FWHM of the spectrum of a ${9} \times {9}$ array is only 0.02 nm, showing a single-mode operation. It provides a potential method to fabricate larger in-phase coherent VCSEL arrays. A remaining challenge is enhancing output power via solving the heat problem.

Tool wear prediction is essential to ensure part quality and machining efficiency. Tool wear is affected by factors such as the material, structure, process, and processing time of the parts. Tool wear under the variable working conditions and the above factors show a complex coupling and timing correlation, which makes it challenging to predict tool wear under variable working conditions. This article aims to resolve this issue. First, we establish a unified representation of working condition factors. The stacked autoencoder (SAE) model adaptively extracts tool wear features from the machining signal. The extracted wear features and respective working conditions then combine into a working condition feature sequence for predicting tool wear. Finally, the advantages of the long short-term memory (LSTM) model to solve memory accumulation effects learn the regular wear pattern of the working condition feature sequence to realize the prediction of the tool wear. An experiment illustrates the effectiveness of the proposed method.

In this paper, a new method for the parameter extraction of Schottky barrier diode (SBD) is presented to eliminate the influence of parasitic parameters on the intrinsic capacitance-voltage (C-V) characteristics of the Schottky diodes at high frequencies. The method is divided into the de-embedding and parameter extraction, including six auxiliary configurations and, is referred tos as Two-step Six-configuration Parameter Extraction Method (TSPEM). Compared to the traditional junction capacitance extraction method, this method can extract the value of junction capacitance at higher frequencies with higher accuracy. At the same time, compared to the other de-embedding methods, this method shows better performance in de-embedding the contributions of parasitic structures from the transmission line measurements. The intrinsic junction capacitances obtained by this method and the three-dimensional (3-D) electromagnetic model are combined to form a diode simulation model, which accurately characterizes the capacitance characteristics of the SBD. It was verified with a 200 GHz double frequency multiplier, and the simulation results and measurement results showed good consistency.

Inspired by data comics, this paper introduces a novel format for reporting controlled studies in the domain of human-computer interaction (HCI). While many studies in HCI follow similar steps in explaining hypotheses, laying out a study design, and reporting results, many of these decisions are buried in blocks of dense scientific text. We propose leveraging data comics as study reports to provide an open and glanceable view of studies by tightly integrating text and images, illustrating design decisions and key insights visually, resulting in visual narratives that can be compelling to non-scientists and researchers alike. Use cases of data comics study reports range from illustrations for non-scientific audiences to graphical abstracts, study summaries, technical talks, textbooks, teaching, blogs, supplementary submission material, and inclusion in scientific articles. This paper provides examples of data comics study reports alongside a graphical repertoire of examples, embedded in a framework of guidelines for creating comics reports which was iterated upon and evaluated through a series of collaborative design sessions.

The present work proposes a 180&ndash, 225 GHz broadband frequency doubler monolithic microwave integrated circuit (MMIC) based on a novel Schottky barrier diode (SBD) terminal structure denoted as a Schottky metal-brim (SMB). Compared with an MMIC adopting the conventional SBD terminal structure, preliminary measurements show that the maximum output power of the MMIC adopting the SMB structure increases from 0.216 mW at 206 GHz to 0.914 mW at 208 GHz. Analysis of the nonlinear current&ndash, voltage and capacitance&ndash, voltage characteristics of the two terminal structures based on an extended one-dimensional drift-diffusion model, indicates that the SMB structure provides significantly better conversion efficiency than the conventional SBD structure by eliminating the accumulation of charge and additional current paths near the Schottky electrode edge. It provides a feasible scheme for the optimization of MMIC applications requiring high power and high efficiency.

A global design method for a terahertz monolithic integrated frequency multiplier is proposed. Compared with a traditional independent design, the method in this paper adopts overall optimization and combines the device with the circuit design. The advantage is that it provides a customized design for frequency multipliers according to specifications. On the basis of the gallium arsenide process of the Institute of Microelectronics, Chinese Academy of Sciences, two types of Schottky diodes have been developed to meet the needs of different designs. On the one hand, a Schottky diode with a 3 &mu, m junction&rsquo, s diameter was used in the design of the 200 GHz balanced doubler and, on the other hand, a diode with a 5 &mu, m diameter was used in the 215 GHz unbalanced tripler. The measured results indicated that the output power of the doubler was more than 250 &mu, W at 180~218 GHz, and the maximum was 950 &mu, W at 198 GHz when driven with 12.3 mW, whereas that of the tripler was above 5 mW at 210~218 GHz and the maximum exceeded 10 mW. Such frequency multiplier sources could be widely used in terahertz imaging, radiometers, and so on.

Giant magnetostrictive actuators (GMA) are widely used in the field of servo valves, but the displacement of GMA is limited, which renders meeting the requirements of large flow direct-drive electro-hydraulic servo valves (DDV) difficult. In order to solve these problems, this study proposes a double-row bow-type micro-displacement amplifier (DBMA), used to increase output displacement of GMA to meet the requirements. This study, by static analysis, analyzes the force of a flexure hinge based on theoretical mechanics and material mechanics, derives the stiffness matrix of the flexure hinge by the influence coefficient method, establishes the pseudo-rigid model, and derives the amplification ratio of a DBMA. Also, by kinetic analysis, using Castigliano&rsquo, s second theorem, a formula of equivalent stiffness and natural frequency of DBMA were derived and the influences of different parameters on them were analyzed, respectively. After that, we analyzed the amplifier using finite element method (FEM) simulation software and verified the model by manufacturing a prototype and building a test system. Theoretical calculations and experimental results showed that the amplification ratio of the DBMA fluctuated between 15.43 and 16.25. The natural frequency was about 305 Hz to 314 Hz and the response bandwidth was up to 300 Hz. The error among the theoretical, simulated, and experimental values was within 8%, supporting the accuracy of the model.

The 808-nm vertical cavity surface emitting laser (VCSEL) with strained In0.13Ga0.75Al0.12As/Al0.3Ga0.7As quantum wells is designed and fabricated. Compared with the VCSELs with Al0.05Ga0.95As/Al0.3Ga0.7As quantum wells, the VCSEL with strained In0.13Ga0.75Al0.12As/Al0.3Ga0.7As quantum wells is demonstrated to possess higher power conversion efficiency (PCE) and better temperature stability. The maximum PCE of 43.8% for 10-μm VCSEL is achieved at an ambient temperature of 30 °C. The size-dependent thermal characteristics are also analyzed by characterizing the spectral power and output power. It demonstrates that small oxide-aperture VCSELs are advantageous for temperature-stable performance.

We demonstrate electrically controlled supermode switching and beam steering in separate-contact phased vertical cavity surface emitting laser arrays based on proton implantation. The mode switching between out-of-phase and in-phase mode was successfully achieved via controlling the injected currents. The beam steering in two directions is continuous and controllable by proper adjustment of driving currents. The properties of near-field, far-field, optical power and spectra under different currents are analyzed detailedly.

We investigate the radiation effects of 1907 MeV Ta ions on the static and dynamic characteristics of 850 nm high-speed vertical cavity surface emitting lasers (VCSELs). The threshold current and slope efficiency are found to be degraded. However, appropriate ion fluence irradiation can improve the modulation bandwidth. The maximum 3 dB frequency is increased to 14.02 GHz from 13 GHz at a fluence of 1 × 108 ions/cm2. The observed behaviour can be explained in terms of reflectivity degradation of lossy distributed-Bragg reflectors as well as the degradation of quantum wells.

We have investigated the dry etching of Al0.12GaAs/Al0.9GaAs Distributed Bragg Reflectors (DBRs) using photoresist mask in Inductively Coupled Plasma system with Cl2/BCl3/Ar chemistry. Resultant etch rate/etch profiles are studied as a function of ICP process parameters and photoresist mask sidewall profile. The vertical and inclined sidewalls were obtained via controlling mixing gas proportion. Enhancing physical effect in etching, photoresist mask patterns could transfer to etched substrate. In the end, controllable sidewall profile, smooth etch surface and repeatable process of Al0.12GaAs/Al0.9GaAs DBRs etching were achieved.

In this paper, we present a newly designed parameter extraction method of the Schottky barrier diode (SBD) with the purpose of measuring and studying its parasitic properties. This method includes three kinds of auxiliary configurations and is named as three-configuration parameter extraction method (TPEM). TPEM has such features as simplicity of operation, self-consistence, and accuracy. With TPEM, the accurate parasitic parameters of the diode can be easily obtained. Taking a GaAs SBD as an example, the pad-to-pad capacitance is 7 fF, the air-bridge finger self-inductance 11 pH, the air-bridge finger self-resistance 0.6 Ω, and the finger-to-pad capacitance 2.1 fF. A more accurate approach to finding the value of the series resistant of the SBD is also proposed, and then a complete SBD model is built. The evaluation of the modeling technology, as well as TPEM, is implemented by comparing the simulated and measured I-V curves and the S-parameters. And good agreements are observed. By using TPEM, the influence of the variation of the geometric parameters is studied, and several ways to reduce the parasitic effect are presented. The results show that the width of the air-bridge finger and the length of the channel are the two largest influencing parameters, with the normalized impact factors 0.56 and 0.29, respectively. By using TPEM and the modeling technology presented in this paper, a design process of the SBD is proposed. As an example, a type of SBD suitable for 500–600 GHz zero-biased detection is designed, and the agreement between the simulated and measured results has been improved. SBDs for other applications could be designed in a similar way.

The optimization of high power terahertz monolithic integrated circuit (TMIC) is systemically studied based on the physical model of the Schottky barrier varactor (SBV) with interface defects and tunneling effect. An ultra-thin dielectric layer is added to describe the extra tunneling effect and the damping of thermionic emission current induced by the interface defects. Power consumption of the dielectric layer results in the decrease of capacitance modulation ration (C max/C min), and thus leads to poor nonlinear C–V characteristics. The proposed Schottky metal-brim (SMB) terminal structure could improve the capacitance modulation ration by reducing the influence of the interface charge and eliminating the fringing capacitance effect. Finally, a 215 GHz tripler TMIC is fabricated based on the SMB terminal structure. The output power is above 5 mW at 210–218 GHz and the maximum could exceed 10 mW at 216 GHz, which could be widely used in terahertz imaging, radiometers, and so on. This paper also provides theoretical support for the SMB structure to optimize the TMIC performance.

The excellent reverse breakdown characteristics of Schottky barrier varactor (SBV) are crucially required for the application of high power and high efficiency multipliers. The SBV with a novel Schottky structure named metal–brim is fabricated and systemically evaluated. Compared with normal structure, the reverse breakdown voltage of the new type SBV improves from –7.31 V to –8.75 V. The simulation of the Schottky metal–brim SBV is also proposed. Three factors, namely distribution of leakage current, the electric field, and the area of space charge region are mostly concerned to explain the physical mechanism. Schottky metal–brim structure is a promising approach to improve the reverse breakdown voltage and reduce leakage current by eliminating the accumulation of charge at Schottky electrode edge.

TA126 solve the job shop dynamic scheduling problem with disruptions, an integrated dynamic scheduling method based on shared mental models is proposed in this paper. Each manufacturing unit in the workshop is mapped into an intelligent agent with the individual mental model for the specific scheduling scenarios. After disturbance occurs, the Q-learning reinforcement learning method is adopted to achieve conflict resolution and consensus consultation among agents, and produce the globally optimized scheduling scheme.

Traditional gear weight optimization methods consider gear tooth number, module, face width or other dimension parameters of gear as design variables. However, due to the complicated form and geometric features peculiar to the gear, there will be large amounts of design parameters in gear design, and the influences of gear parameters changing on gear trains, transmission system and the whole equipment have to be taken into account, which increases the complexity of optimization problem. This paper puts forward to apply functionally graded materials (FGMs) to gears and then conduct the optimization. According to the force situation of gears, the material distribution form of FGM gears is determined. Then based on the performance parameters analysis of FGMs and the practical working demands for gears, a multi-objective optimization model is formed. Finally by using the goal driven optimization (GDO) method, the optimal material distribution is achieved, which makes gear weight and the maximum deformation be minimum and the maximum bending stress do not exceed the allowable stress. As an example, the applying of FGM to automotive transmission gear is conducted to illustrate the optimization design process and the result shows that under the condition of keeping the normal working performance of gear, the method achieves in greatly reducing the gear weight. This research proposes a FGM gears design method that is able to largely reduce the weight of gears by optimizing the microscopic material parameters instead of changing the macroscopic dimension parameters of gears, which reduces the complexity of gear weight optimization problem.

Cognitive maps represent decision makers’ mental maps and their strategies, which are always uncertain, ambiguous and hard to be formalized. In order to make intelligent design decision-making, a Bayesian approach for constructing cognitive maps is proposed in this paper. The cognitive map is modeled compatible with a Bayesian Network. Then cause-effect mapping rules between design elements embedded in cognitive maps can be made explicit by means of network structure learning. A score-based greedy search algorithm is implemented for network structure learning, in which penalized mutual information is defined as the scoring metric and hill-climbing search algorithm is used to find the highest-scoring network. The eliminating loop operator is introduced into the algorithm according to the restriction of the edge directionality.

Additive Manufacturing (AM) is the digital manufacturing technology by which products are fabricated directly from computer models by selectively curing, depositing or consolidating materials in successive layers. The technology has provided an opportunity to rethink the methods of product design to maximize the product performance through the synthesis of material compositions, structure, and sizes. This overview is created to relate the unique capabilities of AM technologies and discuss the methods of product design. Finally, the current problems and difficulties in this field are discussed in this paper, and this paper proposes the development direction of the product design for additive manufacturing in the future.

Electronically controlled optical beam steering is sensitive and reliable. It is significant for phased laser radar applications. We reported the experimental characterization of three-element coherent vertical cavity surface emitting laser arrays and demonstrated two-dimensional electronical beam steering. 2-D far-field patterns, near-field patterns, and the spectra of the beam under different current conditions were measured. It is demonstrated that beam steering is continuous and predicted. Above 17.9% of the total power of the array is concentrated in the central lobe, showing high coupling efficiency. Up to a 3.26° shift angle from normal is demonstrated. The beam steering mechanism of frequency detuning between the three cavities was analyzed via both theory and experiment.

Manufacturing enterprise group possesses the greatest wealth of resources and knowledge for sustainable product and business development. These resources and knowledge have gradually become the key factor of core competitiveness and product innovation for manufacturing enterprise group. However, the resources inenterprise group are usually distributed in different subsidiary companies,which means they can’t be centralized used and can’t be made the most use of,constraining the competition and development of enterprise. It bring soutstanding contradiction problems between the demand and resources sharing. By the comparison of different resource sharing and coordination schemas of current advanced manufacturing paradigms, and the analyzing of the resource requirements and tendency of the sharing and centralized control of resources in manufacturing enterprise group from the develop point of view, a new cloud manufacturing service schema vision for manufacturing enterprise group is proposed based onthe Cloud Manufacturing idea to strengthen manufacturing enterprise group’s management and control power, enhance service capabilities of its resources. As same as the cloud manufacturing idea, the schema promises elasticity, flexibility and adaptability through the on-demand provisioning of manufacturing resources as a utility.

The power source subsystem of satellite is the basic guarantee of the normal orbit for the satellite that provides to energy for the entire satellite. The fault knowledge modeling method for power source subsystem of satellite based on ontology was proposed. Firstly, the failure modes and effects analysis (FMEA) of the power source subsystem of satellite was analyzed, and the fault knowledge was got by extracting key words. Secondly, the ontology of fault knowledge was established. Thirdly, the inference engine based on ontology was realized by analyzing the hierarchical structure of the reasoning system. Only the ontology needs to be created for the fault diagnosis system, which greatly reduces the knowledge creation time.

Manufacturing services are basic building blocks for the agile collaborating business applications. It represents a new model in the utilization of the networked resources, by which self-contained, modular applications can be described, published, located and dynamically invoked in a programming language independent way. In this paper, a general formal model for manufacturing services is proposed by wrapping manufacturing resource into semantic web service. Thus resources sharing requirements are translated into service’s capacity requests. As the key part of manufacturing services, manufacturing capability profile is presented which has four particular attribute sets to represent the infomation what enterprises really care about. Finally, ontology specifications of manufacturing services are established by extending OWL-S, which provides a standard vocabulary to support in an unambiguous, computer-understandable form.

Surviving in an increasing globalization, distribution and flexibility environment, modern manufacturing requires an extremely flexible, self-adaptive foundation capable of dynamic provisioning, coordinating and using infinite manufacturing resources available on demand over large-scale computer networks. In contrast to the conventional networked manufacturing approach, the cloud manufacturing vision (GetCM) introduced in this paper promises elasticity, flexibility and adaptability through the on-demand provisioning of manufacturing resources as a utility by reflecting the basic principles of cloud computing. The discussion is made from technological, functional, economic aspects to provide evidence of the benefits from GetCM in the context of networked manufacturing resource access, provision, sharing and coordination. A primary architecture for GetCM is introduced based on the analysis of key criteria in realizing the vision of a function for cloud manufacturing. Focuses of this paper are placed on the vision and the outline of GetCM architecture.

We apply the antenna coherence theory in order to evaluate characteristic behavior of phase-coherent VCSEL arrays. Large 19-element phase-locked VCSEL arrays with a near-diffraction-limited beam were firstly realized using proton implantation technology. The central lobe intensity is about four times that of side lobes in far-field patterns. The angular full width at half maximum (FWHM) of the far field lobes is only 1.42 degrees. A good matching between theory and experiment opens new perspectives for optimizing devices.

To fully fulfill the modularity and loosely coupled characteristics of P2P semantic mapping paradigm proposed in our previous work[1], a mapping creation method based on semantic discovery is presented to avoid a time-consuming and labor-intensive artificial mapping creation process. This method creates semantic mapping between peer node models by establishing the semantic relations between elements from different peer node models. Semantic relative candidates are captured through the correspondence semantic matching process including concepts matching process, attributes matching process, relations matching process, concepts and relations matching process, and concepts and attributes matching process. To improve the degree of automation for mapping establishment, the hybrid semantic discovery approach is used in the semantic discovery process.

To gain insight into increasingly intricate business, and deal with highly complex problem situations, an enterprise needs a more generic, standardized, pervasive and scalable infrastructure to fully leverage the information from different data sources, applications, and environments at both system level and content level. Based on a discussion of basic problem of EII (enterprise information integration), this paper reviews a state of the art of existing enterprise information integration solutions from content level integration and system level integration perspectives. We evaluate existing approaches to content level integration by comparing the method used to describe and explain the data, and the topology structure of the data connected. We evaluate existing approaches to system level integration by in-depth discussion how the systems are coupled. Based on the results of our analysis we summarize the state-of-the-art in enterprise information integration and give the tendencies of further research.

To support business and engineering collaboration in the diversified and global markets, enterprises are trying hard to continuously align their actual business processes to response customers’ demands. In this context, a flexible framework for inter-organizational process management is proposed, in which ontologies and semantic web service technologies are used throughout process modeling, implementation and execution. Heterogeneous manufacturing resources are encapsulated as uniform semantic web services, called manufacturing services, which are published, located and combined into executable processes. By means of formally definition of service capacity and as the mediation, business logic and implementation techniques is loosely coupling relationship, so enterprises can collaborate without prior relationship established and adjust their processes on demand.

Silicon-on-insulator (SOI) is an attractive platform for single chip photonic integration. Silicon nanowires fabricated by SOI substrate are fundamental components such as ring resonators in the optoelectronics integrated circuits. High performance of these devices requires silicon nanowires have vertical and smooth sidewalls. In this paper, we report the fabrication of silicon nanowires with vertical and smooth sidewalls using SF6/C2H4/Ar based inductively-coupled-plasma (ICP) etching, Ring resonator with 200nm gap was fabricated. This technology is suitable for fabrication of planar photonic integrated components and circuits.

A low-barrier Schottky barrier diode based on the InGaAs/InP material system is designed and fabricated with a new non-destructive dry over-etching process. By using this diode, a high-sensitivity waveguide detector is proposed. The measured maximum responsivity is over 2000 mV/mW at 630 GHz. The measured noise effective power (NEP) is less than 35 pW/Hz 0.5 at 570–630 GHz. The minimum NEP is 14 pW/Hz 0.5 at 630 GHz. The proposed high-sensitivity waveguide detector has the characteristics of simple structure, compact size, low cost and high performance, and can be used in a variety of applications such as imaging, molecular spectroscopy and atmospheric remote sensing.

Machining error prediction is an important advance towards optimum machining. In this paper, we define the prediction problem as a classification task where process characteristics impacting on machining errors are attribute variables and error results are class variables. To deal with non-linearity and invisible correlations among process characteristics, the Bayesian network-based classifier learning from historic information is applied to extract hidden knowledge between process characteristics and resulting machining errors. Given an instance from the set of process characteristics describing, the posterior probability of each machining error result can be calculated using Bayes rules. An experiment for surface roughness (Ra) prediction on Al 7055 high-strength aluminum alloy in high speed cutting was presented, in which three Bayesian network-based classifiers, namely Naive Bayesian Classifier, Tree-Augmented Network Classifier and General Bayesian Network Classifier, learnt from the experimental dataset simultaneity. Up to 84.6 % accuracy was achieved by GBNC which was selected as the surface roughness prediction model. Therefore, the Bayesian network-based classifier is a valid method for machining error prediction.

Aiming at the problem of the low utilization rate of knowledge in product lifecycle, and the problem of the knowledge that cannot be take full use to serve the business process, a construction scheme of the knowledge service oriented to product lifecycle was proposed. Firstly, the demands of knowledge service oriented to product lifecycle were analyzed and the basic concepts and characteristics of knowledge service were put forward. Secondly, the model of knowledge service and its structure was built; the integration of the system, the acquisition of the multi-source heterogeneous knowledge, and the technologies of knowledge push have been analyzed. Finally, part of the system function was given to illustrate the feasibility of the proposed method.

Aiming at the problem of the low utilization rate of knowledge, low rate of staff dependence on knowledge management system, and the problem of lack of effective evaluation system and method, a comprehensive evaluation method of enterprise knowledge and employees was proposed. The knowledge evaluation system of multilevel and index was established based on the characteristics of knowledge resources and employee behaviors in knowledge management system. And then a knowledge evaluation model was constructed. The knowledge utility was used to represent the total index of knowledge. The method divided knowledge utility into knowledge quality and knowledge influence. The individual total score was divided into participation and contribution used to represent the total index of staff. According to this model, evaluation algorithm of each index was put forward. Finally, an example test was used to demonstrate the effectiveness and feasibility of the proposed method.

In order to monitor the false alarm and fault middle state in the process of fault diagnosis simultaneously, a mixed Hidden Markov Model(HMM) considering the false alarm and fault middle state was proposed to reduce the false alarm and monitor the middle state of the system. First of all, the state classification in the process of the complex system state monitoring was studied. The system states were divided into normal state, intermittent failure, random failure, intermediate state and failure state, and then the mixed HMM was established to reflect the true state of the system. Secondly, the effective feature vectors were extracted based on wavelet packet decomposition method to eliminate redundancy and high dimension of original characteristic signal. Then all kinds of the HMM states were obtained through the model training, and fault diagnosis was implemented through inputting feature vector. At last, the feasibility and effectiveness of the method was verified by an example.

A Schottky barrier diode with low-barrier is presented, based on which a terahertz waveguide detector working at 500–600 GHz is designed and fabricated. By using the InGaAs/InP material system, the feature of the low barrier is obtained which greatly improves the performance of the detector. The measured typical voltage responsivity is about 900 V/W at 500–560 GHz and is about 400 V/W at 560–600 GHz. The proposed broadband waveguide detector has the characteristics of simple structure, compact size, low cost and high performance, and can be used in a variety of applications such as imaging, molecular spectroscopy and atmospheric remote sensing.

In order to obtain an advantageous position in the protean global market, the modern manufacturing enterprises require a flexible and self-adaptive foundation which is capable of dynamically exploiting manufacturing resources and services distributed across the network. In this paper, the cloud manufacturing vision (GetCM) is introduced to provide the on-demand architecture with reliability, flexibility and reliability based on cloud computing. In contrast to the conventional networked manufacturing paradigm, the paper analyzes from technological, functional and economic aspects to provide the evidences of the benefits from GetCM. A primary architecture for GetCM is introduced based on the analysis of key criteria in realizing the vision of a function for cloud manufacturing. Focuses of this paper are placed on the vision and the outline of GetCM architecture.

Manufacturing grid is a new pattern developed to answer unprecedented challenges in manufacturing industry, one of the most important foundations of which is encapsulating or modeling manufacturing resources into grid service. But this kind of grid service is restricted by ambiguous and insufficient service description. This paper presents an ontology model, called M-service profile ontology, which provides the framework for explicitly encoding semantics of domain-specific engineering information. The model is generated by extending OWL-S with two classes. One is ManufacturingProfile class which provides formal engineering indexes needed during collaborative work. Anther is the QoSProfile class which provides a mechanism to represent quality of service. This ontology model enriches semantic descriptions of grid service which will be very conducive for later service discovery and management.

Based on investigating challenges of product knowledge sharing in distributed environment, a context-sensitive product knowledge sharing architecture is proposed. Through a discussion of fundamental model for elucidating and characterizing context in knowledge sharing, and the mechanism of knowledge utilizing, annotating and clustering based on this knowledge context model, we present a context-sensitive query mechanism to spread query over the whole knowledge sharing network by establishing query graph and implementing context-sensitive routing. A prototype system is implemented to prove technical feasibility of the proposed approach.

Modern product development needs a large number of knowledge contained at all stages of product life cycle. In order to deal with the discrete, heterogeneous expression, scenario dependence of various types of product knowledge, a context-driven knowledge-sharing approach is presented, covering product knowledge modeling, describing and organizing. Through building product knowledge context model, product knowledge is linked with the relevant generation and application scenarios. Based on the model, a template-based product knowledge description method is proposed. With analyzing the description results, a self-organization method is proposed for product knowledge organization. The context-driven knowledge-sharing approach which aims at discrete distributed environment, contains a wealth of context-sensitive scenario semantics, has self-organizing capacity, can effectively solving product knowledge sharing problems.

Recent advances in grid, semantic web, P2P and web services have revolutionized the way we communicate and collaborate. Undertaking the intersection fulfillment of these technologies on enterprise desktop computers enables new integrative and collaborative use of not only organizational data but also distributed, autonomous personal data on the web by fully leveraging potentially useful information sources on many desktops. In this context, we introduce SDDG, a pip-semantic-grid enabled information sharing infrastructure for entire enterprise information, which wraps both organizational and personal information sources as semantic grid services and creates a semantic information interoperability environment following a p2p data coordination way. Through a discussion of fundamental scientific positions in general and approaches to information integration research in particular, we depict the basic integration principles from both P2P and semantic grid perspectives. The key contributions of this paper are a P2P semantic grid service oriented framework for SDDG, which is an extension of our previous work [1] [2] by reflecting principles of P2P data integration in semantic grid.

Based on a discussion of data understanding hierarchy, this paper reviews a state of the art of existing enterprise information integration solutions from semantic perspective. We divide existing approaches into three categories: programming semantic-based integration, syntax schema-based integration, and declarative semantic-based Integration, and evaluate the approaches in each category by comparing the method used to describe and explain the data, and the topology structure of the data connected. Based on the results of our analysis we summarize the state-of-the-art in semantic enterprise information integration and give the tendencies of further research.

Collaborative product development has become important business strategy. In this paper, a framework for autonomous collaborative product development, in which a set of intelligent agents handle major interact tasks based on ontology, is presented. By wrapping engineering applications using agents, the framework applies generalized knowledge repository to leverages relative resources, knowledge and designer in a collaborative way. The detailed application functionality and structure of agents is studied. Finally, communication process between agents is provided, which identifies distributed participators enable to share heterogeneous data via messages of agents.

We report the fabrication and accurate measurement of propagation and bending losses in silicon wires with submicron dimensions fabricated on silicon-on-insulator wafer. Propagation loss of 0.71±0.03dB/mm for the TE polarization was measured at the 1.55µm. Loss of per 90° bend is measured to be 0.01dB for a bending radius of 5µm. Three types of compact MMI splitters with different splitting-ratios were fabricated and measured. The splitting-ratios are respectively 50∶50, 15∶85 and 28∶72. They exhibited low excess losses of about 1.5∼3.9dB. The splitting-ratios were consistent with the design values.

Electroabsorption modulator has been widely used in modern optical fiber communication system and analog RF link system. In this paper, the design of a high-performance EAM with low coupling loss, high saturation power and high speed was demonstrated, which include the waveguide, active core and electrodes. A novel EAM with large optical cavity (LOC) waveguide structure, intrastep quantum well (IQW) active core and traveling wave electrodes was presented and fabricated successfully. Our results show that the LOC waveguide effectively improved the optical profile of EAM and reduced the coupling loss. The obtained traveling wave EAM achieved 21dBm saturation power and 23GHz 3-dB bandwidth.

A 330–500 GHz zero-biased broadband monolithic integrated tripler is reported. The measured results show that the maximum efficiency and the maximum output power are 2% and 194 μW at 348 GHz. The saturation characteristic test shows that the output 1 dB compression point is about −8.5 dBm at 334 GHz and the maximum efficiency is obtained at the point, which is slightly below the 1 dB compression point. Compared with the conventional hybrid integrated circuit, a major advantage of the monolithic integrated circuit is the significant improvement of reliability and consistency. In this work, a terahertz monolithic frequency multiplier at this band is designed and fabricated.