摘要：AIM：To determine the agreement and repeatability of the pupil measurement obtained with VIP-200（Neuroptics）,Power Ref II（Plusoptix）,WAM-5500（Grand Seiko） and study the effects of instrument design on ***：Forty patients were measured twice in low,mid and high *** was analyzed with the within-subject standard deviation（Sw） and paired *** was studied with Bland-Altman plots and repeated measures *** design analysis consisted on measuring pupil size with Power Ref II simulating monocular and binocular conditions as well as with proximity cues and without proximity ***：The mean difference（±standard deviation） between test-retest for low,mid and high mesopic conditions were,respectively：-0.09（±0.16）,-0.05（±0.18） and-0.08（±0.23） mm for Neuroptics,-0.05（±0.17）,-0.12（±0.23） and-0.17（±0.34） mm for WAM-5500,-0.04（±0.27）,-0.13（±0.37） and-0.11（±0.28） mm for Power Ref *** agreement with Neuroptics,the mean difference for low,mid and high mesopic conditions were,respectively：-0.48（±0.35）,-0.83（±0.52） and-0.38（±0.56） mm for WAM-5500,-0.28（±0.56）,-0.70（±0.55） and-0.61（±0.54） mm for Power Ref *** mean difference of binocular minus monocular pupil measurements was：-0.83（±0.87） mm;and with proximity cues minus without proximity cues was：-0.30（±0.77） ***：All the instruments show similar *** all illumination conditions,agreement of Neuroptics with WAM-5500 and Power Ref II is not good enough,which can be partially induced due to their open field design.

摘要：This paper addresses the present-day context of Systems Engineering, revisiting and setting up an updated framework for the SIMILAR process in order to use it to engineer the contemporary systems. The contemporary world is crowded of large interdisciplinary complex systems made of other systems, personnel, hardware, software, information, processes, and facilities. An integrated holistic approach is crucial to develop these systems and take proper account of their multifaceted nature and numerous interrelationships. As the system＇s complexity and extent grow, the number of parties involved （stakeholders and shareholders） usually also raises, bringing to the interaction a considerable amount of points of view, skills, responsibilities, and interests. The Systems Engineering approach aims to tackle the complex and interdisciplinary whole of those socio-technical systems, providing the means to enable their successful realization. Its exploitation in our modern world is assuming an increasing relevance noticeable by emergent standards, academic papers, international conferences, and post-graduate programmes in the field. This work aims to provide ＂the picture＂ of modern Systems Engineering, and to update the context of the SIMILAR process model in order to use this renewed framework to engineer the challenging contemporary systems. The emerging trends in the field are also pointed-out with particular reference to the Model-Based Systems Engineering approach.

摘要：In order to ensure that a structure does not collapse when subjected to the action of strong ground motions, modern codes include prescriptions in order to guarantee the ductile behavior of the elements and of the whole structure. Obviously, it would be of special importance for the designer to know during the design process the extent of damage that the structure will suffer under the seismic action specified by the design spectrum and also the probability of occurrence of different states of behavior. The incremental nonlinear static analysis procedure used in this paper allows formulating a new, simplified, seismic damage index and damage thresholds associated with five limit states. The seismic behavior of a set of regular reinforced concrete buildings designed according to the EC-2/EC-8 prescriptions for a high seismic hazard level is then studied using the proposed damage index and damage states. Fragility curves and damage probability matrices corresponding to the performance point are calculated for the studied buildings. The obtained results show that the collapse damage state is not reached in the buildings designed according to the prescriptions of EC-2/EC-8 and also that the damage does not exceed the irreparable damage limit state.

摘要：This study evaluates the seismic response of an existing two stories RC building using non-linear analysis. The original model was resized and there were obtained two buildings designed under two different methodologies to fulfill the Venezuelan codes requirements for a high seismic hazard. An elastic analysis was applied to the original building in order to verify interstory drifts;the resizing building it was designed under requirements of strong column-wake beam condition. A third building was modeled according to the seismic displacement design procedure. It were performed non-linear static analysis and 2D and 3D dynamic analyses, obtaining capacity curves, structural ductility, structural performance point, global and interstory drifts for each building. Torsional effects for the resizing building were also computed from 3D analysis. In the original building it was obtained a weak seismic behavior, while resized buildings presented good seismic performance under the Limits States evaluated in this study.

摘要：The object of this study is to determine the seismic response of regular high-rise steel buildings with chevron-braced frames. Mechanics models of three buildings of 14, 18 and 20 stories are studied, all of them with similar geometric characteristics in plant and elevation. These models are realized using prescriptions and parameters from venezuelan design codes. The seismic action is carry on through varius synthetic design spectrum compatible accelerograms defined by the seismic codes in this study, with three levels of intensity corresponding to three specific Limit States. Dynamic analysis is used to compute parameters of ductility, over strength and maximum displacements. From these results it can be concluded that chevron-braced frames presented a good overall performance and non V-braced frames show greater damage due to dynamic actions, validating non linear dynamic analysis as a very powerful tool to seismic-resistance design and chevron-braced frames as a very useful choice in improving the response of tall steel structures. since this lateral bracing system is absent from Venezuelan seismic codes.

摘要：用于示波器振幅控制的最常见电路之一是软限幅电路（图1α）。当输出电压VOUT（＋）低时．二极管D，和D2关断。因此，所有输入电流VIN（＋）／R1都流经反馈电阻R2，而输出电压为：

摘要：大多数振荡电路都带有一个非线性的波幅控制．它将振荡保持在所要求的波幅内．使之有最小的输出失真。一种方案是采用输出正弦波的振幅来控制一个电路元件的阻值．如一只工作在三极管特性区的JFET的阻值。另一种控制方法是采用一个限幅电路．使振荡幅度达到限幅器的阈值。当使用限幅器时．输出波幅保持恒定。为了尽量减小非线性失真和输出削波．限幅器应表现出一种“软”的特性。

摘要：音效均衡器一般都需要二阶带通滤波器。这种单元需要能简单而独立地调整其参数：中心频率ω0、品质因数Q、及最大带通增益k。要使用有独立调节能力的单元,需要采用可变状态的拓扑结构。可是,这种结构一般最少需要三个运算放大器。一种代替方案的基础是采用SAB（四乘幂单放大器）滤波器。这些单元可实现二阶带通滤波器,但有两个主要缺点：通过这些单元所能达到的品质因数有实际的最大极限，而且也不能独立地调整三个特征参数。