Adaptive alignment packaging for 2-D arrays of free-spaceoptical-interconnected optoelectronic systems

An adaptive alignment scheme for packaging two-dimensional (2D) arrays of optoelectronic systems interconnected by free-space optics is presented. A method of using three quadrant detectors to detect alignment errors in six degrees of freedom is described. However, the complexity of this system increases due to the interactions among the detected error signals. A novel control algorithm is presented to eliminate the interaction and simplify the design of the closed-loop feedback control. A computer simulation compares different algorithms and shows the effectiveness of the proposed algorithm. An experimental closed-loop feedback system demonstrated the principle of the error detection and correction of the proposed system with initial errors in multiple degrees of freedom     

Knowledge sharing in virtual enterprises via an ontology-based access control approach

Collaborating throughout a product life cycle via virtual enterprise (VE) is one of the most promising strategies for enhancing global competitiveness. Efficient and secure knowledge sharing is critical to the success of a VE. This study presents a novel approach, model and technology for knowledge access control and sharing across enterprises. First, this study proposes an ontology-based knowledge sharing model and a multiple-layer knowledge representation framework on which a knowledge access control model for knowledge sharing in a VE is proposed. In the proposed model, user authorizations permitting access to knowledge in a VE are classified into two levels: (1) basic privileges and (2) extended privileges. The former is evaluated from four dimensions, i.e. who, what, when and where, while the latter is determined by considering how three domain ontologies, i.e., product, organization and activity, are related. This study then develops a knowledge access control policy (KACP) language model which is used to identify the knowledge access control and sharing rules of a VE and all its enterprise members. The knowledge access control model proposed in this study can facilitate VE Knowledge management and sharing across enterprises, enhance knowledge sharing security and flexibility and regulate knowledge sharing to expeditiously reflect changes in the business environment.     

A low voltage-power 13-bit 16 MSPS CMOS pipelined ADC

A low voltage-power, 13-bit and 16 MSPS analog-to-digital converter (ADC) was implemented in 0.25-/spl mu/m one-poly five-metal standard CMOS process with MIM capacitors. This ADC used a constant-gm switch to improve the nonlinear effect and a telescopic operational transconductance amplifier with a wide-swing biasing technique for power saving and low supply voltage operation. The converter achieved a peak SNDR of 59.2 dB with 16.384 MSPS, a low supply voltage of 1.3V, and Nyquist input frequency of 8.75 MHz. The static INL of /spl plusmn/2.0 LSB and DNL of /spl plusmn/0.5 LSB were obtained. The total power consumption of this converter was 78 mW. This chip occupied 3.4 mm /spl times/ 3.6 mm area.     

Development of free-space digital optics in computing

To someone with an electronics or computer science background, many of optical computing's concepts may seem outlandish. Optics grew out of applied physics and still retains many aspects of that heritage. This is in contrast to digital computing's roots in electronics. Recent efforts have been made to bring optical computing more in line with microelectronic engineering. Perhaps that will speed the acceptance of opto-electronic technology. The authors describe their research into optical devices for data communication. They are investigating free-space optics, the propagation of optical signals through the air using lenses and mirrors to focus and redirect the beams. The advantages of free-space optics, derive from their large spatial bandwidth and physical channel density. Like the human eye, which takes in an enormous amount of information in parallel, a low-cost lens can provide more than a million independent connections. The authors aim to exploit optoelectronic computing's capability for such massively parallel data transfers     

Developing an RFID-based tracking system to improve the control of construction surplus soil disposal in Taiwan

The current tracking system for construction surplus disposal soil report system (CSRS) in Taiwan is labor-intensive and prone to human error, with its accuracy and effectiveness often questioned. Radio-frequency identification (RFID) is a wireless sensing technology that uses radio waves and signals to wirelessly transmit, retrieve, and store data to identify the status of objects and contents. It can be read at long ranges and be operated in extreme environments. This paper has improved the existing construction surplus soil tracking system by developing an integrated RFID-based tracking system (RFID-CSRS). To accommodate the characteristics of the domain problems, RFID-CSRS integrates RFID technology with Internet infrastructure, cameras, and signal controlling units. The proposed system reduces human errors, such as incorrect manual recording and identification, inaccurate monthly reports and audits, and improper picture-taking of trucks. RFID-CSRS was also assembled and tested in two surplus soil disposal cases in Taiwan. The results demonstrated the soundness of the system and its capability to improve the effectiveness of the current system in tracking the disposal of construction surplus soil.     

Bus-driven floorplanning with thermal consideration

As the increasing number of buses in multi-core SoC designs, bus planning problems become a dominant factor in determining the chip performance. To cope with these issues, it is desirable to consider them in the early floorplanning stage. Recently, many bus-driven floorplanners have been proposed in the literature. However, these proposed algorithms only consider the bus planning problem without the thermal effect. As a result, there are hotspots, which result in high chip temperature, on the chip. In this paper, a thermal-driven bus-driven floorplanning algorithm is proposed to separate hotspots during the perturbation stage and to keep buses away from hotspots during the routing stage. To avoid time-consuming thermal simulations, the superposition of thermal profiles, which are the thermal distribution of each module, is adopted to efficiently estimate the module temperature. Compared with the state-of-the-art bus-driven floorplanner, experimental results demonstrate that the proposed algorithm can effectively separate hotspots and reduce the chip temperature.     

Smooth-pursuit eye tracking in first-episode psychotic patients and their relatives.

In order to determine the specificity of smooth-pursuit eye tracking dysfunction to schizophrenia (SC) and the prevalences of dysfunction among functionally psychotic and normal individuals, the authors investigated pursuit tracking in a large sample of psychotic patients, normal Ss, and 1st-degree relatives (N?=?482). Ss were recruited as part of an epidemiological study of 1st-episode psychosis that used a broadly based referral network to identify all cases in a major metropolitan area over a 2.5-yr period. Ss received diagnoses of SC, schizophreniform disorder, psychotic mood disorder, and paranoid or other psychotic disorder based on the Diagnostic and Statistical Manual of Mental Disorders (DSM-III). The distribution of tracking performance was bimodal for the SC Ss and their relatives, perhaps reflecting major gene action. Moreover, poor tracking ran in families. Pursuit tracking dysfunction was relatively specific to SC Ss and their relatives and occurred infrequently in other psychotic Ss and normal Ss. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Modeling mechanical stress effect on dopant diffusion in scaled MOSFETs

The effect of shallow trench isolation mechanical stress on MOSFET dopant diffusion has become significant, and affects device behavior for sub-100-nm technologies. This paper presents a stress-dependent dopant diffusion model and demonstrates its capability to reflect experimental results for a state-of-the-art logic CMOS technology. The proposed stress-dependent dopant diffusion model is shown to successfully reproduce device characteristics covering a wide range of active area sizes, gate lengths, and device operating conditions.