扭摆式微硅隧道加速度传感器

本文介绍了扭摆式隧道加速度传感器的结构、工作原理、简化的力学模型,设计了版图、工艺流程及关键工艺,并制备出样品,最后给出测试电路和结果。     

A Distributed Cooperative MAC Protocol for QoS Improvement and Mobility Support in WiMedia Networks

A Distributed Medium Access Control (D-MAC) protocol based on UWB for high-rate Wireless Personal Area Networks is specified by the WiMedia Alliance. D-MAC protocol is suitable for ubiquitous connection in home networks, military/medical applications due to its inexpensive cost, low power consumption, high data rate, and distributed approach. In contrast to IEEE 802.15.3, D-MAC makes all devices have the same functionality. And its networks are self-organized and provide devices with functions such as access to the medium, channel allocation to devices, data transmission, quality of service and synchronization in a distributed manner. D-MAC fundamentally removes the problems of the centralized MAC approach revealed at IEEE 802.15.3 MAC by adopting a distributed architecture. However, the current D-MAC can’t prevent QoS degradations, occurred by mobile nodes with low data rate due to bad channel status, which cause critical problems in QoS provisioning to isochronous streams and mobile applications. Therefore, we propose a distributed cooperative MAC protocol for multi-hop WiMedia networks using virtual MIMO links. Based on instantaneous Channel State Information among WiMedia devices, our proposed protocol can intelligently select the transmission path with higher data rate to provide advanced QoS with minimum delay for real-time multimedia streaming services.     

A Novel Cogging Torque Reduction Method for Interior-Type Permanent-Magnet Motor

This paper presents a novel design method to reduce the cogging torque of interior-type permanent-magnet (PM) motor. In the design method, the optimal notches are put on the rotor pole face, which have an effect on the variation of PM shape or the residual flux density of PM. Through the space harmonic field analysis, the positions of notches are found, and the optimal shapes of notches are determined by using finite element method. The validity of the proposed method is confirmed by experiments.     

Effect of foreign exchange management on firm performance using genetic algorithm and VaR

Management of foreign exchange risk is considered to be as important as trading results in firm performance when international trading and transaction of different kind of currencies are getting popular. Most previous researches on this issue have been based on the foreign exchange market and financial investing and accounting, focusing on theoretical point of view. And it is difficult to apply these research results to each company, since all companies in industry have different financial circumstances. In this paper, the solution for the foreign exchange management is proposed using GA and VaR which is very practical to export-oriented companies. The developed software enables a user to specify the criteria for the foreign exchange trading condition, constraints on dealing amount, GA operator and penalty, and variables in VaR. This approach is useful for managing foreign exchange holdings of a company in a practical way, analyzing past exchange rate trend with dealing results.     

An analysis of CH4/N2 rich biogas production, fuel treatment process and microturbine application

Biogas usually contains CH₄ and CO₂ as main components with the ratio of 6: 4, and its composition varies with wide range depending on digester conditions. In addition to concentration change of each constituent, biogas composition could be changed due to the variations in the organic matter treatment process. The aim of the study is to analyze the production and application to a microturbine system of CH₄/N₂ rich biogas produced from Gong-Ju wastewater treatment plant. CH₄/N₂ rich biogas is produced due to the internal wastewater recirculation. The internal wastewater recirculation is intended to enhance NO₃ ^? removal without additional carbon source input. As a result, the digester was shown to be the highest contributor for nitrogen removal and average CH₄ concentration was lowered compared to the typical biogas composition. Nitrate removal rate was influenced by the internal recirculation ratio. Content of N₂ has no effect on biogas clean-up system performance. Besides, adaptability of CH₄/N₂ rich biogas to microturbine was satisfactory with very low NOx and SO₂ concentration in microturbine exhaust gas. Influence of high N₂ concentration of biogas on NOx concentration was limited due to the low combustion temperature.     

Quality characteristics of imitation crab sticks made from Alaska Pollack and spent laying hen meat

Imitation crab stick (ICS) samples were divided into four treatments, a control (C) prepared with Alaska Pollack as a commercial ICS, T1, which consisted of Alaska Pollack with spent laying hen surimi collected by the pH adjust method, T2, which was composed of Alaska Pollack with spent laying hen surimi collected by the filter cake method, and T3, which consisted of Alaska Pollack with whole spent laying hen meat batter collected by the cutting method. The moisture content was significantly higher in T3 than in the other ICS samples; but, there was no significant difference in the crude protein, fat and ash content, regardless of the spent laying hen substitution methods. The lightness (L∗) and whiteness (W) was higher in the control than in the other ICS samples at 0 days of storage, whereas the yellowness (b∗) was significantly higher in T3 than in the other ICS samples. The level of polyunsaturated fatty acids was significantly higher in the control group than in the other ICS samples. Additionally, the pH increased with storage time in the spent laying hen substituted samples (T1, T2 and T3), with T1 showing a significantly higher pH during storage. The TBARS value increased with storage time in all ICS samples, with T2 showing a significantly lower TBARS value than the other ICS samples at the beginning and end of the storage periods. There was no significant difference in any sensory evaluation items among the ICS samples during storage. Thus, we assumed that T3 was better than other ICS samples, because T3 method (cutting) is much easier to collect spent laying hen surimi than T1 (pH adjust) and T2 (filter cake).     

Departure process of a single server queueing system with Markov renewal input and general service time distribution

The independence of processes in queueing systems is generally assumed when developing queueing models. However, real systems often involve several process dependencies, and failure to take these into consideration can lead to serious underestimation of the performance measures. We consider herein a single server queueing system with a Markov renewal process (MRP) for its arrival process and a general service time distribution, and derive the distribution function and correlation coefficient of the departure process. Since the departure process also often corresponds to an arrival process in downstream queues, the results obtained here can be used to derive a better approximation of the performance measures of a non-product form general queueing network.     

Adaptive History-Based Memory Schedulers for Modern Processors

Careful memory scheduling can increase memory bandwidth and overall system performance. We present a new memory scheduler that makes decisions based on the history of recently scheduled operations, providing two advantages: It can better reason about the delays associated with complex DRAM structure, and it can adapt to different observed workload.     

Risk factors for high blood lead levels among the general population in Taiwan

BACKGROUND: Tacrolimus (FK506) may represent a major advance in the management of allograft rejection after solid organ transplantation. In August 1994 a European heart transplantation pilot study was initiated to assess the efficacy and safety of tacrolimus when administered exclusively through an oral route. METHODS: Eighty-two heart transplant recipients were randomized to treatment (2:1 ratio) with either tacrolimus- (n=54) or cyclosporine-based therapy (n=28). RESULTS: No significant differences were evident between the two treatment groups in either rejection or survival rates at 1 year. Kaplan-Meier estimates of the freedom from rejection were 26.3% and 18.5%, respectively, for the tacrolimus and cyclosporine treatment groups (p=.444). Survival rates were 79.6% and 92.9% (p=.125). At 3 of the 5 centers, patients received antithymocyte globulin during the immediate postoperative period and fared better than those who did not (with acute rejection-free rates of 49.2% and 26.7% for tacrolimus and cyclosporine, respectively [p=.080], as opposed to 7.1% and 8.3% [p=.965]; patient survival rates of 84.6% and 93.3% [p=.382] vs 75.0% and 92.3% [p=.243]). The overall rates of infection, impaired renal function (31.5% vs 21.4%), and glucose intolerance (7.0% vs 4.3%) did not differ significantly between the tacrolimus and cyclosporine treatment groups. Tacrolimus seemed to possess an advantage with regard to a reduced requirement for antihypertensive therapy (59.5% vs 87.5%, p=.025). CONCLUSIONS: Immunosuppression with oral tacrolimus provides a viable alternative to treatment with cyclosporine, particularly when administered in conjunction with antibody therapy. Further studies are warranted to optimize the administration of tacrolimus in this indication.     

Vacuum punch biopsy of the breast with a stereotaxic guide. A new procedure for percutaneous diagnostic biopsy based on 120 cases

PURPOSE: To test the capabilities of vacuum core biopsy (VCB) in the diagnosis of mammographically indeterminate lesions. MATERIALS AND METHODS: 120 patients (131 lesions) were examined using VCB with 14G or 11G vacuum core. RESULTS: VCB was mostly performed because of indeterminate microcalcifications (67 cases) or soft tissue densities/architectural distortion (64 cases). 112 benign changes, 14 DCIS and 5 invasive carcinomas were found. Excellent accuracy was achieved (presently 100%), since complete excision of small lesions/areas (< or = 1 cm) or partial excision of larger lesions was possible. No relevant hematomas or infections occurred. Patients tolerated the painless procedure very well. DISCUSSION: This report confirms our previous experiences. This method promises to replace diagnostic open biopsy of indeterminate or suspicious nonpalpable lesions.