Model-based monitoring of diamond turning process using cross entropy

This paper discusses the model-based monitoring as one of key steps toward building an inprocess diagnostic tool for the supervisory level control in diamond turning. In particular, estimation of surface profile from a nonlinear force model and model-based monitoring of tool chipping are demonstrated. Classification rule is based on the minimization of information-theoretic measure called the cross entropy. The experimental results indicate that monitoring strategy based on the minimum cross entropy guarantees the consistent and optimum classification results in the presence of varying cutting conditions. In addition, the cross entropy as a criterion for indicating the dynamic quality of machine-tool is explained.     

The effect of topical corticosteroids on refractive outcome and corneal haze after photorefractive keratectomy

BACKGROUND: The effect of topical corticosteroids after excimer laser photorefractive keratectomy (PRK) remains a matter of some controversy. Refractive effects may be different according to the amount of myopia and timing of instillation. METHODS: Two groups of patients were studied: Study A consisted of 215 eyes (128 patients) with PRK (mean baseline myopia, -6.53 +/- 2.22 D) that received no corticosteroids (No Corticosteroid Group) unless significant regression or corneal haze appeared (Delayed Corticosteroid Group), and in Study B, we randomly assigned eyes to the Initial Corticosteroid Group (mean baseline myopia, -6.39 +/- 1.84 D) or the No/delayed Corticosteroid Group (mean baseline myopia -5.78 +/- 2.02 D). Clinical results after PRK for low-to-moderate and high myopia were compared. RESULTS: In the first group, 70.9% (73 eyes) of moderately myopic eyes (mean, -4.56 +/- 1.10 D) belonged to the No Corticosteroid Group that had a mean refraction of -5.39 +/- 1.77 D. Delayed Corticosteroid Group eyes were more myopic (mean, -7.52 +/- 2.10 D), and showed more severe haze than those in the No Corticosteroid Group. In study B, only in high myopes with more than -6.00 D (mean, -7.76 +/- 1.15 D) did refraction and corneal haze outcomes show significant difference between the Initial Corticosteroid Group and the No/delayed Corticosteroid Group. CONCLUSIONS: The effects of topical corticosteroids after PRK were less in moderate myopes compared to high myopes. Delayed instillation of corticosteroids did not reverse the regression or haze whereas initial instillation showed a beneficial effect on high myopes but not on moderate myopes.     

Arthroscopic reduction and fixation of bony avulsion of the posterior cruciate ligament of the tibia

Bony avulsion fractures of the posterior cruciate ligament of the tibia have commonly been treated by open reduction and internal fixation using the posterior approach. However, this approach, using the prone position, makes it difficult to investigate and treat other combined injuries of the knee joint. We report a case of posterior cruciate ligament avulsion of the tibia that was arthroscopically reduced and firmly fixed with two cannulated screws. The posterior sag was absent after the operation and the result was excellent. By arthroscopy, we got rigid fixation of the avulsed fragment for early rehabilitation, and detection of a concomitant injury was also possible.     

CAD-oriented formulas for the quasi-tem parameters of shielded and semi-enclosed (coupled) coplanar waveguides

On the magnetic-wall approximation for their slots, shielded coplanar waveguides (SCPWs) and semienclosed CPWs (SECPWs) are analyzed through an intensive use of elliptic function transformation. CAD-oriented formulas for the quasi-TEM parameters of SCPWs and SECPWs, including their coupled versions, are derived. The comparison of the results calculated here with previous ones show 2% accuracy for formulas in the practical situation where the slots are not too wide, e.g., s / (s + 2w) ≥ 0.2 for an SCPW. © 1994 John Wiley & Sons, Inc.     

工业过程随机稳态优化控制算法的鲁棒性分析

本文给出了一种随机稳态优化算法的灵敏度分析，讨论算法解对参数变化的关系。这些参数代表系统结构参数或噪声向量的某些数字特征．     

光纤检漏系统

本文介绍一种新型的光纤检漏系统,通过对待测件内气体状态分析,确定采用比较法充压检漏技术和先进的光纤技术,研制成既具有高检测灵敏度又稳定可靠的检漏系统。该系统已成功地用于工业生产中,对水库大坝仪器实现了在线充压检漏,保证产品质量。     

用晶种技术解决低品位石灰石配料中存在的问题

采用晶种技术，能有效地改善熟料的煅烧过程和熟料的质量。晶种和复合矿化剂的作用机理不同，在某些方面具有互补性。     

怎样合理安装冲压模具

对冲压模具的安装过程进行了分析,提出了在冲模安装过程中应注意或考虑的事项。     

模袋混凝土护坡在永定河滞洪水库工程中的应用

模袋混凝土护坡是一种新型的护面技术,具有整体性强、冲灌的混凝土强度可根据工程具体要求设计的优点.它克服了其它护面型式的诸多缺点,成为十分成熟的护面新技术.随着土工合成材料在水利工程上大面积推广应用,模袋混凝土护坡具有良好的应用前景.     

Bandwidth Adaptation Algorithms for Adaptive Multimedia Services in Mobile Cellular Networks

The fluctuation of available link bandwidth in mobilecellular networks motivates the study of adaptive multimediaservices, where the bandwidth of an ongoing multimedia call can bedynamically adjusted. We analyze the diverse objectives of theadaptive multimedia framework and propose two bandwidth adaptationalgorithms (BAAs) that can satisfy these objectives. The firstalgorithm, BAA-RA, takes into consideration revenue and``anti-adaptation' where anti-adaptation means that a user feelsuncomfortable whenever the bandwidth of the user's call ischanged. This algorithm achieves near-optimal total revenue withmuch less complexity compared to an optimal BAA. The secondalgorithm, BAA-RF, considers revenue and fairness, and aims at themaximum revenue generation while satisfying the fairnessconstraint defined herein. Comprehensive simulation experimentsshow that the difference of the total revenue of BAA-RA and thatof an optimal BAA is negligible. Also, numerical results revealthat there is a conflicting relationship between anti-adaptationand fairness.