Abstract Traditional synchronous motion control of a multi-cylinder system was always achieved by using hydraulic loops design and constrained linkage mechanisms. Therefore, these control methodologies always have many disadvantages, such as inaccuracy, cost expensive, and huge volume of the equipment, and so on. In this paper, the nonlinear control strategy was proposed to control the proportional directional valves of two-cylinder electro-hydraulic system in order to achieve synchronous motion under the consideration of unbalanced and uncertainty loading. Besides, in order to explore influence of different loading to the system, two-cylinder mechanism was designed to have individual loading device without any hardware constrain between two pistons. And the maximum loading capacity for one piston is 210kg. Due to the highly complicated coupling effect of internal pressure and flow rate for two cylinders, in this paper, feedforward controller with three fuzzy controllers was designated to overcome the problem of synchronous motion. In the first, the feedforward controller of each cylinder is developed to track a desire velocity trajectory. Then, the fuzzy control of each cylinder was specified to improve the individual tracking performance. Finally, the third fuzzy controller was performed to compensate the coupling effect of two-cylinder in order to progressively improve the performance of synchronous motion. According to the experimental results, the proposed control strategy for synchronous motion of two-cylinder system was verified and the maximum synchronous error of the total system was controlled to be within 10mm. Keyword: synchronous motion; proportional directional valve; fuzzy controller; feedforward controller

The objective of this study is to apply Computer-generated imagery for knowledge and skills in daily life. There are some Computer-generated imagery study on traditional education training; however, fewer professional image processing courses of Synchronous Learning Networking are carried out in practice. The feasibility of using lecture video or practice on line in teaching Computer-generated imagery concepts is important. How do teachers examine students¡¦ performance and make good use of Synchronous Learning Networking? In this study, we will propose the following dimensions to discuss: (1) the difference on Computer-generated imagery between Synchronous Learning Networking and traditional teaching (2) the difficulty on Computer-generated imagery when teaching and learning (3) how to make better performance on Computer-generated imagery under Synchronous Learning Networking. Comparative Case Study is conducted at Tainan Training Center and LMS (Learning Management System) of K12 digital school for the adults who actively study Computer-generated imagery by the means of traditional learning and E-learning. We put Computer-generated imagery under traditional teaching and Synchronous Learning Networking, and we make questionnaires for examining the detailed factors regarding to the performance of Computer-generated imagery.The results indicates that lecture on Synchronous Learning Networking is something about practice on line, whiteboard, slides show, top desk share and homepage browse with office hours and paper work in replace of real discussion. Sometimes teachers and students are meeting the information and interaction delay under Synchronous Learning Networking. Therefore, we are offering seven suggestions to get Computer-generated imagery under Synchronous Learning Networking improved: (1) Teachers suggest that the standard of hardware and Net environment is required. (2) Students should develop active attitude for learning under Synchronous Learning Networking. (3) Teachers should perform on line teaching and stream video is auxiliary. (4) Multiple material for the topic is available for students to choose and adjust their learning model. (5) Dividing into groups is not good for teaching and office hour or guest board is much better for discussion and interaction. (6) Teachers should create new Computer-generated imagery courses to inspire students¡¦ motivation. (7) Continued materials and platform for students to review and interact are required.

This thesis presents a novel configuration of battery power by the outputs with serial connection of battery power modules (BPMs) for high voltage level loads. As compared to the conventional application of series-connected battery bank, this configuration operates the BPMs individually, and thus has the advantages of flexible control, convenient maintenance, and easily favorable battery management. The associated converter is equipped to a single battery pack, so that has lower component stresses leading to a higher circuit efficiency. The operation and the design of a lead-acid battery power with series boost-typed BPMs are illustrated. The operation and the design of the converter are illustrated. The control of the power converters is accomplished by a complex programmable logic device (CPLD). To improve the converter efficiency, the technique of synchronous rectification is introduced. For the BPMs designed for discontinuous conduction mode (DCM) operation, charge equalization can be automatically achieved under the same duty-ratio, but is adequate only for batteries with a small difference. On the other hand, charge equalization for the BPMs with continuous conduction mode (CCM) can easily be accomplished by regulating the duty-ratios of the converters.

<p>Abstract</p><p>This essay deals with the creation and usage of nicknames in synchronous CMC. Nicknames from four different IRC chat conversations related to three different topic groups have been examined. The method draws on Bechar-Israeli’s (1996) categorisation of nicknames, which has been adapted to suit the type of data sampled. Three research questions have been posed, which, in view of other studies related to this field of research (e.g. Ellison et al. 2006, Scheidt 2001, Chester & Gwynne 1998, etc.) have been examined to obtain information about the degree of anonymity and the topic-relatedness of nicknames used in chatrooms. The results show that users participating in synchronous CMC indeed follow topic-related rules for self-presentation and that anonymity has varying importance in different chatrooms.</p>

Thesis (M. Phil.)--University of Hong Kong, 1982.

With the scaling of technology nodes, the speed performance of microprocessors has rapidly improved but the scaling of off-chip input/output (I/O) bandwidth is limited by physical pin resources and interconnect technologies. In order to reduce the performance gaps, new interface techniques have emerged and the marketplace has moved towards higher levels of integration with system on a chip (SoC) implementations. The advent of new techniques, however, has led to new challenges on the semiconductor and automated test equipment (ATE) industries. The relatively slow growing ATE technology comparing to I/O speeds especially intensifies manufacturing test issues. Testing high speed I/O timing parameters requires expensive high performance test equipment with high accuracy and resolution. The requirements increase integrated circuit (IC) manufacturing costs and thus test issues have become critical. This thesis focuses on on-chip test methods to improve test accuracy and reduce test costs for high speed double data rate (DDR) memory I/Os using source synchronous clocking. For testing the I/O timing parameters, a phase interpolator based on-chip timing sampler using a cycle-by-cycle control method was developed. This circuit generates data and clock patterns and controls the time delay between data and clock to detect the timing mismatch which indicates timing degradations. The on-chip timing sampler was implemented as a built-in self test (BIST) circuit for low-cost parametric timing measurements. The BIST scheme was fabricated with a 0.18-um CMOS process technology. Using the static and dynamic modes, measurement results are obtained for the I/O timing parameters such as the setup and hold times, input voltage-level variations tolerances, duty distortion tolerances and data skews. Moreover, a delay mismatch measurement method was developed to improve measurement accuracy using a simple control circuit. This delay mismatch detector measures timing mismatches between data and clock paths and then the timing mismatches are converted to timing specifications. This scheme is also implemented along with analog to digital converter (ADC) to collect digital test results supporting low-cost system-level tests. Thus, the low-frequency test results show that our on-chip measurement techniques provide an attractive low-cost solution and is effectively applied for testing high speed source synchronous systems. / text

Cognitive sensor platforms are the next step in the evolution of intelligent sensor platforms. These platforms have the capability to reason about both their external environment and internal conditions and to modify their processing behavior and configuration in a continuing effort to optimize their operational life and functional utility. The addition of cognitive capabilities is necessary for unattended sensor systems as it is generally not feasible to routinely replace the battery or the sensor(s). This platform provides a chassis that can be used to compose embedded sensor systems from composable elements. The composable elements adhere to a synchronous data flow (SDF) protocol to communicate between the elements using channels. The SDF protocol provides the capability to easily compose heterogeneous systems of multiple processing elements, sensor elements, debug elements and communications elements. The processing engine for this platform is a Dataflow-Processing Element (DPE) that receives, processes and dispatches SDF data tokens. The DPE is specifically designed to support the processing of SDF tokens using microcoded actors where programs are assembled by instantiating actors in a graphical modeling tool and verifying that the SDF protocol is adhered to. / text

published_or_final_version / Electrical and Electronic Engineering / Doctoral / Doctor of Philosophy

ITC/USA 2014 Conference Proceedings / The Fiftieth Annual International Telemetering Conference and Technical Exhibition / October 20-23, 2014 / Town and Country Resort & Convention Center, San Diego, CA / The wireless acquisition system LISA has been designed for mechanical phenomenon analysis onboard aircrafts. It has been in use for more than one year now. This paper describes the organization of this equipment and the experiences related by first users.

ITC/USA 2013 Conference Proceedings / The Forty-Ninth Annual International Telemetering Conference and Technical Exhibition / October 21-24, 2013 / Bally's Hotel & Convention Center, Las Vegas, NV / Instead of using a single data acquisition device, the distribute data acquisition system is broadly applied for onboard flight testing now. Therefore, the sync of data acquisition in varied devices and the real time data transportation have become the most important factors in a telemetry system. This paper presents a new approach to clock synchronization in a real time transportation network for a data acquisition system by using IRIG time code and an inner timer through network time recovery technique. This paper also illustrates how to keep the synchronization and continuity of a time tag used by each device through a precise estimation method for the difference of time resources and local inner timers.