Design and dynamics of an innovative micro gyroscope against coupling effects

This paper presents an innovative micro gyroscope design. The proposed tri-axis gyroscope possesses the capability of detecting three-dimensional angular motions. The motion of each sensing element is, by elaborate mechanical design, restricted to move in orthogonal direction to each other such that the measurements by high-resolution capacitors with signal processing circuits are decoupled and precisely represent, to some extent, angular velocity components in three axes. The drive electrode comb is used to constantly vibrate the proof mass in tangential direction by sinusoidal voltage. The signal bandwidth is increased by distributed translational proof masses, placed ninety degree apart from each other. Each individual proof mass is designed to move solely in radial direction so that superior mode matching can be achieved. In order to ensure better repeatability and more reliability, the suspension flexures and damping effects are studied such that stress of the proposed micro gyroscope is reduced but the span of angular displacements is increased. Owing to the complicated geometry of the suspension flexures, finite element method (FEM) is employed to obtain more exact stiffness values and compared with theoretical analysis. The dynamic model of the proposed gyroscope is established to include non-linear terms and embedded mechanical constraints. The entire micro device can be produced merely by surface fabrication such that the mass production cost can be considered at the design stage, while the resolution, bandwidth and decoupling capability of tri-axis detection are enhanced.     

Analysis of a 0.1-μm stepping bi-axis piezoelectric stage using a 2-DOF lumped model

Piezoelectric stages are widely used for parts manipulation, including micro-component assembly and bio-cell manipulation. This paper proposes a bi-axis piezoelectric stage based on a friction driven mechanism. The carrier slides on a supporting frame and slider constructed in the same plane as a low-profile stage. The dynamic model of the friction driven is based on a 2-DOF lumped model considering the impact and separation behavior. The first mass is the bulk piezoelectric actuator (slab)—as a vibrator—and the second is the driven slider. The stiffness ratio of the piezoelectric slab-to-the driven slider affects the output force of the slider because of the contact time ratio. Moreover, the stepping size is adjusted according to the duty ratio of the pulse width of the driving signal. The stepping size of 0.1 μm is achieved in the X and Y axes corresponding to 3% and 5% of the duty ratio, respectively, of 512-Hz carrier frequency in 20-Vpp driving signal. When the duty ratio is 100%, the full speed of 18 and 16 mm/s are achieved in the X- and Y-axes, respectively. The dimensions of the piezoelectric stage are 61 × 58 × 21.3 (high) mm³.

     

Near UV LEDs made with in situ doped p-n homojunction ZnO nanowire arrays

Catalyst-free p-n homojunction ZnO nanowire (NW) arrays in which the phosphorus (P) and zinc (Zn) served as p- and n-type dopants, respectively, have been synthesized for the first time by a controlled in situ doping process for fabricating efficient ultraviolet light-emitting devices. The doping transition region defined as the width for P atoms gradually occupying Zn sites along the growth direction can be narrowed down to sub-50 nm. The cathodoluminescence emission peak at 340 nm emitted from n-type ZnO:Zn NW arrays is likely due to the Burstein-Moss effect in the high electron carrier concentration regime. Further, the electroluminescence spectra from the p-n ZnO NW arrays distinctively exhibit the short-wavelength emission at 342 nm and the blue shift from 342 to 325 nm is observed as the operating voltage further increasing. The ZnO NW p-n homojunctions comprising p-type segment with high electron concentration are promising building blocks for short-wavelength lighting device and photoelectronics.     

Toward Cloud-Based Parking Facility Management System： A Preliminary Study

An e-tag used on the freeway is a kind of passive sensors composed of sensors and radio-frequency identification (RFID) tags. The principle of the electronic toll collection system is that the sensor emits radio waves touching the e-tag within a certain range, the e-tag will respond to the radio waves by induction, and the sensor will read and write information of the vehicles. Although the RFID technology is popularly used in campus management systems, there is no e-tag technology application used in a campus parking system. In this paper, we use the e-tag technology on a campus parking management system based on the cloud-based construction. By this, it helps to achieve automated and standardized management of the campus parking system, enhance management efficiency, reduce the residence time of the vehicles at the entrances and exits, and improve the efficiency of vehicles parked at the same time.     

Computerized Color Distinguishing System for Color Printed Fabric by Using the Approach of Probabilistic Neural Network

This article proposes an innovative color printed fabric computer color distinguishing system whose main functions are to precisely distinguish the printed fabric pattern colors and match colors to improve the current time-consuming color distinguishing conducted by manpower. The RGB color mode is an industrial color standard, by which the change and overlapping of color channels of red, green, and blue represent types of colors. RGB stands for red, green, and blue, respectively. It is one of the most widely used color system and covers almost all of the colors sensible to human vision. Hence, this paper adopts the RGB color mode to present color printed fabric images. First, to reduce the color distinguishing computation, a genetic algorithm was applied in search of small images of the same color in the original color printed fabric. Then, color distinguishing computation was conducted by a probabilistic neural network (PNN), which has the advantage of a very fast learning speed. Finally, PANTONE® standard color tickets were applied in matching colors. The experimental results revealed that the PNN design can easily realize and achieve accurate, fast color classification. It is proved that this color distinguishing system can be practically applied in printed fabric color distinguishing and matching.     

The design and development of a computerized tool support for conducting senior projects in software engineering education

This paper presents a computerized tool support, the Meetings-Flow Project Collaboration System (MFS), for designing, directing and sustaining the collaborative teamwork required in senior projects in software engineering (SE) education. Among many schools’ SE curricula, senior projects serve as a capstone course that provides comprehensive training in collaborative project development. With the focus on collaboration training, instructors of senior projects often address issues that include how to encourage collaboration and ensure that collaborative efforts are sustained throughout the project’s development. In order to help resolve these issues, the MFS takes a holistic approach. The meetings-flow concept that undergirds the MFS introduces a novel macro-level and meeting-oriented group process to guide the proceeding of the project’s collaborative work. The design of the MFS facilitates a computerized environment that helps to institutionalize and monitor such a group process. In introducing the MFS, we focus initially on the elaboration of the concept and design, after which we present and validate the system implementation and usage. We also evaluate the MFS and receive a positive result with respect to the educational issues raised in this paper. Finally, we comparatively summarize the MFS to discuss its values and the role it plays in CSCL (computer supported collaborative learning) and PBL (project-based learning) of SE education.     

Dual-axis tuning fork vibratory gyroscope with anti-phase mode vibration mechanism

In this paper, a novel micro-machined dual-axis tuning fork gyroscope (DTFG) with an anti-phase mechanism is proposed. The proposed anti-phase mechanism could effectively minimize the undesired lateral motion and ensure the anti-phase resonant mode of the two vibrating frames of DTFG. The gyroscope is fabricated by the high-aspect-ratio silicon-on-insulation bulk micromachining process with a device layer thickness of 45 μm. Furthermore, a CMOS drive/readout ASIC Chip, which is fabricated by a 0.25 μm 1P5M standard CMOS process, is integrated with the fabricated DTFG by direct wire-bonding. The experimental characterizations of DTFG demonstrate that the rate sensitivities of z-axis and x-axis sense modes are 2.2132 mV/DPS and 1.8477 mV/DPS respectively and the associated R²-linearity are 0.9995 and 0.9996.     

A holistic approach to managing software change impact

Change is inevitable in the software product lifecycle. When a software change occurs, all of the stakeholders and related artifacts should be considered in determining the success of the change action in a collaborative development environment such as JAD (joint application development). In this regard, current implementation-based or homogeneous impact analyses are insufficient; therefore, this paper presents a holistic approach to change impact analysis in handling not only software contents but also other items such as requirements, documents and data. This approach characterizes product contents and relates heterogeneous items by using attributes and linkages. It also uses an object-oriented propagation mechanism to handle dynamic looping in determining the impact of changes. A prototype, EPIC, was built to realize this approach and these concepts. A walkthrough example is provided in order to verify the work of the proposed approach. An empirical study is presented to discuss the benefits of the proposed approach and the application of EPIC in a software company. Lessons learned from the case study and improvement issues of the proposed approach and the tool are also discussed.