Browsing by Author "Lin, YT"

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An automatic focusing algorithm
(2002)
Lin, SF
;
Lin, YT
;
Su, CK
;
電控工程研究所
;
Institute of Electrical and Control Engineering
A simple and effective automatic focusing algorithm is proposed in this article. The principle of the proposed automatic focusing algorithm is based on that, for the radial test pattern, a best-focused image should have the smallest blurred region in the middle of the acquired image, and hence, should have the smallest equivalent radius. The circular Hough transform has became a common method in numerous image-processing applications for circle detection. Various modifications to the basic circular Hough transform have been suggested, such as: the inclusion of edge orientation, simultaneous consideration of a range of circle radii, the use of a complex accumulator array with the phase proportional to the log of the radius, or for filter operations. The purpose of this work is to show that a radius of a circular region extracted by a normalized circular Hough transform is a possible solution for determining the sharpness of images. To acquire high quality images with a given CCD camera, it is crucial that the camera be located exactly at the back length of the lens, i.e., the focus position of the lens. In the best conditions, the contours of the acquired images are of the sharpest, with none of the blurring effects associated with unfocused images. Acquiring such high quality images by these means is the main goal of the automatic focusing algorithm proposed in this article. (C) 2003 Wiley Periodicals, Inc.
An intrusion detection model based upon intrusion detection markup language (IDML)
(2001-11-01)
Lin, YT
;
Tseng, SS
;
Lin, SC
;
資訊工程學系
;
Department of Computer Science
Due to the rapid growth of networked computer resources and the increasing importance of related applications, intrusions which threaten the infrastructure of these applications have are critical problems. In recent years, several intrusion detection systems designed to identify and detect possible intrusion behaviors. In this work, an intrusion detection model is proposed to for building an intrusion detection system which can solve problems involved in building an intrusion detection systems, including pattern representation. computability, performance, extendibility and maintenance problems. In this model, IDML is first designed to express intrusion patterns, and these patterns are transformed into intrusion pattern state machines. Once the intrusion pattern state machines are obtained, the corresponding intrusion detection mechanism that can use these state machines to detect intrusions is designed. To evaluate the performance of our model, an IDML-based intrusion detection experimental system based upon this architecture has been implemented.
Broadband service creation and operations
(1997-12-01)
Lin, YD
;
Lin, YT
;
Chen, PN
;
Choy, MM
;
資訊工程學系
Three challenges for deploying broadband services are the time-consuming process of service creation, the interoperability over heterogeneous platforms, and the gap between the needs of service management and the functionalities of network management. In this article we describe a methodology to attack the first two challenges, namely, to simplify the process of service creation and provide a platform-independent framework for service operations. A set of broadband service-independent building blocks (SIBs) are designed and used to create and customize SIB graphs for broadband services. During service running time, the service agent interprets a SIB graph and executes SIB procedures which are all downloaded from the service provider. Web, Java, and CORBA are the technological elements of this methodology. Two examples, video conferencing and video on demand, are given to demonstrate the feasibility of this approach.
Broadband service creation and operations
(1997-12-01)
Lin, YD
;
Lin, YT
;
Chen, PN
;
Choy, MM
;
資訊工程學系
Three challenges for deploying broadband services are the time-consuming process of service creation, the interoperability over heterogeneous platforms, and the gap between the needs of service management and the functionalities of network management. In this article we describe a methodology to attack the first two challenges, namely, to simplify the process of service creation and provide a platform-independent framework for service operations. A set of broadband service-independent building blocks (SIBs) are designed and used to create and customize SIB graphs for broadband services. During service running time, the service agent interprets a SIB graph and executes SIB procedures which are all downloaded from the service provider. Web, Java, and CORBA are the technological elements of this methodology. Two examples, video conferencing and video on demand, are given to demonstrate the feasibility of this approach.
Design and implementation of new object-oriented rule base management system
(2003-10-01)
Lin, YT
;
Tseng, SS
;
Tsai, CF
;
資訊工程學系
;
Department of Computer Science
In this work, a knowledge model, new object-oriented rule model (NORM), is proposed based on the concept of learning and thinking behaviors of human. It provides high maintainability and reusability through the object-oriented concept. There are four basic relations between knowledge concepts defined in NORM: Reference, Extension-of, Trigger and Acquire. These relations are helpful in describing the cooperation of the different knowledge concepts. In addition, we describe how to construct and maintain a knowledge base under this model. A NORM knowledge modeled rule base system platform, DRAMA, is also introduced and applied in this paper. In order to illustrate the capability of NORM knowledge model, a learning management system using DRAMA to infer the knowledge for selecting appropriate learning content for different student is designed and implemented. (C) 2003 Elsevier Ltd. All rights reserved.
Design of a sensorless commutation IC for BLDC motors
(2002)
Cheng, KY
;
Lin, YT
;
Tso, CH
;
Tzou, YY
;
電控工程研究所
This paper presents the design methodology to implement a sensorless commutation IC for brushless dc (BLDC) motors by using mixed-mode IC design technology. The developed IC can generate optimal commutation signals for BLDC motors without Hall-effect sensors and can be easily interfaced with a microcontroller or a digital signal processor (DSP) to complete the closed-loop control system. Furthermore, this IC solution requires less analog compensation circuits than other commercial motor control ICs, therefore, high maintainability and accurate control can be achieved. The proposed sensorless commutation IC is integrated in a standard digital single-poly, and four metal 0.35-mum CMOS process.
Dual-stage soliton compression of a self-started additive pulse mode-locked erbium-doped fiber laser for 48 fs pulse generation
(2006-05-15)
Lin, YT
;
Lin, GR
;
光電工程學系
;
Department of Photonics
A dual-stage single-mode fiber (SMF) and large-effective-area fiber (LEAF) link for generating 48 fs pedestal-free pulses from a 40 MHz self-started additive pulse mode-locked erbium-doped fiber laser (APM-EDFL) with output peak power and pulse energy of 16 kW and 500 pJ, respectively, is demonstrated. With the SMF+LEAF link, a maximum pulse-width compression ratio of 7 and an optimized pulse-energy confining ratio of up to 85% can be achieved, and the soliton self-frequency shift effect of the APM-EDFL pulse can be greatly suppressed. (c) 2006 Optical Society of America
GMNF-DVMRP: A modified version of Distance Vector Multicast Routing Protocol
(1997)
Lai, YC
;
Lin, YD
;
Yu, WC
;
Lin, YT
;
交大名義發表
In this paper, we make a survey of Distance Vector Multicast Routing Protocol (DVMRP) and find that it is not optimal in the aspect of network cost (NC). Therefore, we propose a modified version of DVMRP, called ''Group Membership Near First-DVMRP'' (GMNF-DVMRP), to decrease the NC of the multicast tree formed by DVMRP. A simulation is implemented to compare our modified version and the original DVMRP. We find that our method save about 5-7 percent of NC of the multicast tree formed by DVMRP.
Intrusion detection markup language (IDML) and IDML based intrusion detection model
(2001)
Lin, YT
;
Tseng, SS
;
Lin, SC
;
資訊工程學系
;
Department of Computer Science
Due to the rapid growth of networked computer resources and the increasing importance of related applications, intrusions which threaten the infrastructure of these applications become critical problems today. In recent years, several intrusion detection systems have been proposed designed to identify and detect possible intrusion behaviors, In this work, an intrusion detection model is proposed to build an intrusion detection system which can solve the issues for building intrusion detection system, including Pattern representation, Computability, Performance, Extendibility and Maintenance. In the model, IDML is first designed to express intrusion pattern, and these patterns will be transformed into intrusion pattern state machines. Once the intrusion pattern state machines are obtained, the corresponding intrusion detection mechanism which can use these state machines to detect intrusions is designed. To evaluate the performance of our model, an IDML-based intrusion detection experimental system based upon the architecture is implemented, and finally some concluding remarks are given.
Nanofabrication and properties of the highly oriented carbon nanocones
(2005-03-01)
Wang, WH
;
Lin, YT
;
Kuo, CT
;
材料科學與工程學系
;
Department of Materials Science and Engineering
A process to fabricate Co-assisted carbon nanocones (CNCs) was successfully developed by using microwave plasma chemical vapor deposition (MP-CVD). The nanostructures could be manipulated by adjusting the ratios of the source gases (CH4/H-2=5/80-15/80 sccm/sccm) and the substrate bias (0 similar to-300 V). The properties of deposited nanostructures were characterized by field emission scanning electron microscopy (FESEM), Raman Spectroscopy, auger electron spectroscopy (AES) spectra. The results show that the nanostructures with cone shape are resulted from competition between the ion bombardment rate and the growing speed of the nanostructures in the plasma, where ion bombardment is drove by the presence of negative substrate bias. In other words, a higher substrate negative bias (>-150 V) and a lower concentration of carbon species in the plasma are favorable conditions to grow highly oriented CNCs due to a greater ion bombardment energy and lower lateral growth rate of the nanostructures, respectively. The results indicate that CNCs synthesized under the applied bias of -300 V show an excellent performance in field emission current density (up to similar to 173 mA/cm(2) at 10 V/mu m). (c) 2004 Elsevier B.V. All rights reserved.
New triple self-aligned (SA3) split-gate flash cell with T-shaped source coupling
(2005-10-01)
Sung, HC
;
Lei, TF
;
Huang, CM
;
Kao, YC
;
Lin, YT
A new triple self-aligned (SA3) split-gate flash cell with a T-shaped source coupling approach is described in this paper. This novel structure can significantly enhance coupling capacitance between the Source and floating gate without increasing cell size. The enhancement can be simply modulated by an oxide-etching step. This new structure can be applied to program voltage reduction and cell size scaling. For program voltage reduction, the maximum program voltage of the new cell can be reduced from 7.4 to 6AV, which is characterized by a newly developed methodology for program vs disturb window characterization. For cell size scaling, comparable sort-1 and sort-2 yields are demonstrated using the new cell with a shorter floating length and a shallower source junction. To understand the relationship between source coupling ratio (SCR) and the program/erase mechanism, an insightful discussion on the program and erase mechanisms for our split-gate flash cell is also shown in this paper.
Novel program versus disturb window characterization for split-gate flash cell
(2005-03-01)
Sung, HC
;
Lei, TF
;
Hsu, TH
;
Kao, YC
;
Lin, YT
In this letter, a new methodology for program versus disturb window characterization on split gate Flash cell is presented for the first time. The window can be graphically illustrated in V-wI (word-line)-V-ss (source) domain under a given program current. This method can help us understand quantitatively how the window shifts versus bias conditions and find the optimal program condition. The condition obtained by this method can have the largest tolerance for program, bias variations. This methodology was successfully implemented in 0.18-mum triple self-aligned (SA3) split-gate cell characterization to provide program condition for 32 M products.
Novel single-poly EEPROM with damascene control-gate structure
(2005-10-01)
Sung, HC
;
Lei, TF
;
Hsu, TH
;
Wang, SW
;
Kao, YC
A novel single-poly EEPROM using damascene control gate (CG) structure is presented in this letter. The CG is tungsten (W) line made by a damascene process, and intergate dielectric is Al2O3 grown by atomic layer deposition (ALD). The program and erase mechanism is the same as the one for traditional stacked-gate cell, which uses the channel hot electron injection for programming and Fowler-Nordheim tunneling for channel erasing. With the high dielectric constant (K) property of Al2O3, we can perform the program and erase function with a voltage less than 6.5 V, which can be handled by 3.3 V devices instead of traditional high voltage devices. In the process compatibility aspect, this new cell needs only two extra masking steps over the standard CMOS process, and the high-kappa material is deposited in the back-end metallization steps without the contamination concerns on the front-end process. Therefore, this new technology is suitable for embedded application. In this letter, the good cell performance is demonstrated; such as, fast programming/erasing, good endurance and data retention.
Ontology-based knowledge fusion framework using graph partitioning
(2003)
Kuo, TT
;
Tseng, SS
;
Lin, YT
;
資訊工程學系
;
Department of Computer Science
For a variety of knowledge sources and time-critical tasks, knowledge fusion seems to be a proper concern. In this paper, we proposed a reconstruction concept and a three-phase knowledge fusion framework which utilizes the shared vocabulary ontology and addresses the problem of meta-knowledge construction. In the framework, we also proposed relationship graph, an intermediate knowledge representation, and two criteria for the fusion process. An evaluation of the implementation of our proposed knowledge fusion framework in the intrusion detection systems domain is also given.
Optimum configuration and design of 1480-nm pumped L-band gain-flattened EDFA using conventional erbium-doped fiber
(2000-09-01)
Liang, TC
;
Chen, YK
;
Su, JH
;
Tzeng, WH
;
Hu, C
We theoretically investigate optimum configurations of 1480-pumped L-band (1570-1610 nm) gain-flattened erbium-doped fiber amplifier (EDFA), using conventional erbium-doped fiber, for multi-wavelength wavelength division multiplexing (WDM) systems. The design criterion of L-band EDFA is to achieve the highest channel output power while keeping the differential channel output power to be less than or equal to 0.7 dB among 32 digital baseband channels with low channel noise figure of less than or equal to 5.5 dB. A total of nine L-band EDFA configurations are examined and compared. These configurations considered include the dual-forward, dual-backward, and different bi-directional pumping schemes, each with and without the midway optical isolator. Among all configurations, we find that the pump-passed case in forward-and-backward pumping scheme is the best amplifier configuration to offer the highest channel output power with good channel gain uniformity and moderate low noise figure. In addition, the tolerance of the ratio of first-staged EDF length to the total EDF length, and the effects of optical isolation of midway isolator, and pump power degradation on the characteristics of the best configuration are also examined. This investigation provides the EDFA configuration selection for multi-wavelength WDM L-band lightwave systems. (C) 2000 Published by Elsevier Science B.V.
Phase conjugation of optical pulses in fibers and in semiconductor laser amplifiers
(1996)
Chi, S
;
Lin, YT
;
Wen, S
;
光電工程學系
;
Department of Photonics