Browsing by Author "Liu, PC"

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A generic software framework for the software system architecture design and implementation of handset devices
(2005)
Liu, PC
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Tsai, MJ
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Chen, DJ
;
資訊工程學系
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Department of Computer Science
The traditional approach to develop user interface for handset devices has limited flexibility on the UI requirement changes. Once the UI requirement changed, programmers have to change their handcrafted application once again. This change may occur repeatedly until the UI requirement under consideration is satisfied. Visual-Based Software Construction Methodology has been developed This methodology helps programmers to develop the user interface for handset devices, and allows programmers to migrate their program to new platform quickly. Based on this methodology, we quest for a generic software framework to incorporate the proposed methodology for developing user interface to alleviate the problems mentioned above. From our study, there are some similarities exist among user interface and software framework in different handset devices. In this paper, we propose a generic software framework for the system architecture design of handset devices. Specifically, the software framework generated based on the genetic software framework will be much easier for maintenance and management compared Kith the traditional approach. In addition, the software framework hat is instantiated from the generic software framework can be incorporated into the visual requirement authoring system for user interface development. Finally, we design and construct a simulator to demonstrate the applicability and usefulness of the software framework generated by the proposed generic software framework.
Bonding line-patterned In0.5Ga0.5P layer on GaP substrate for the successive growth of high-brightness LED structures
(2005)
Liu, PC
;
Wu, YCS
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材料科學與工程學系
;
Department of Materials Science and Engineering
The heteroeptixial integration of the III-V semiconductor compound, which was limited by lattice mismatch, can now be accomplished by using the wafer bonding process. In this study, a line-patterned In0.5Ga0.5P layer was successfully transferred to the GaP wafer through the wafer bonding process for the successive growth of high-brightness light-emitting diode (LED) structures. (C) 2004 The Electrochemical Society.
Combinative motion estimation algorithm and the corresponding architecture for complex motion phenomenon
(1998-02-01)
Liu, PC
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Chang, WT
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Shen, WZ
;
電子工程學系及電子研究所
;
Department of Electronics Engineering and Institute of Electronics
Combining the features of block matching algorithm and block recursive algorithm a new motion estimation method is proposed for complex motion phenomenon. With the full searching procedure used in block matching algorithm and the adaptive searching procedure used in block recursive algorithm, the proposed combinative algorithm can be used to estimate more complex motion parameters such as translation, zoom, rotation and image deformation and get good performance. To reduce the computational complexity, the corresponding architecture of the combinative algorithm is also proposed. With this architecture the computation amount can be largely reduced to make the proposed algorithm can be used for real time motion estimation.
Decoupling control of pickup head motion in near-field optical disk drives
(2002)
Liu, TS
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Liu, PC
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機械工程學系
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Department of Mechanical Engineering
For the flying pickup head in near-field optical disk drives, this study attaches a piezoelectric bender to the pickup head and develops a single-input multi-output control method to deal with the bender motion in both bending deflection and longitudinal displacement.
Effects of annealing temperature on electrical resistance of bonded n-GaAs wafers
(2004-11-22)
Liu, PC
;
Lu, CL
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Wu, YCS
;
Cheng, JH
;
Ouyang, H
The electrical characteristics and microstructures of n-type (100) GaAs bonded interfaces were systematically investigated. Experimental results indicated that GaAs did not bond directly to itself, but via an amorphous oxide layer at 400 degreesC. When temperatures increased above 400 degreesC, the oxide bonded area declined and finally disappeared. Electrical resistance decreased with bonding temperature. However, the resistance increased with temperatures exceeding 850 degreesC. (C) 2004 American Institute of Physics.
Electromigration in pb-free SnAg3.8Cu0.7 solder stripes
(2005-08-01)
Hsu, YC
;
Chou, CK
;
Liu, PC
;
Chen, C
;
Yao, DJ
Electromigration behavior in the eutectic SnAg3.8Cu0.7 solder stripes was investigated in the vicinity of the device operation temperature of 100 degrees C by using the edge displacement technique. Measurements were made for relevant parameters for electromigration of the solder, such as drift velocity, threshold current density, activation energy, as well as the product of diffusivity and effective charge number (DZ(*)). The threshold current densities were estimated to be 4.3x10(4) A/cm(2) at 80 degrees C, 3.2x10(4) A/cm(2) at 100 degrees C, and 1.4x10(4) A/cm(2) at 120 degrees C. These values represent the maximum current densities that the SnAg3.8Cu0.7 solder can carry without electromigration damage at the three stressing temperatures. The electromigration activation energy was determined to be 0.45 eV in the temperature range of 80-120 degrees C. The measured products of diffusivity and the effective charge number, DZ(*), were -1.8x10(-10) cm(2)/s at 80 degrees C, -5.0x10(-10) cm(2)/s at 100 degrees C, and -7.2x10(-10) cm(2)/s at 120 degrees C. (c) 2005 American Institute of Physics.
High-temperature healing of interfacial voids in GaAs wafer bonding
(2002-02-15)
Wu, YCS
;
Liu, PC
;
Feigelson, RS
;
Route, RK
;
材料科學與工程學系
Artificial voids were introduced at bonding interfaces to study how processing parameters affected the healing mechanism of interfacial voids in GaAs wafer bonding. These voids were created by placing unpatterned wafers in contact with topographically patterned wafers. During the bonding process, crystallites formed within these voids and corresponded to bonded regions within the voids. Their formation depended strongly on the height of the surface irregularities at the wafer interfaces. When the void depth (h) was greater than or equal to200 nm, most of the crystallites were diamond shaped. The edges of the diamond features were elongated in the <100> direction. On the other hand, when the void depth was small (hless than or equal to70 nm), dendrites grew quickly in the <110> direction. (C) 2002 American Institute of Physics.
Measurement of electromigration parameters of lead-free SnAg3.5 solder using U-groove lines
(2005-10-01)
Hsu, YC
;
Chen, DC
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Liu, PC
;
Chen, C
;
材料科學與工程學系
Measurement of electromigration parameters in the lead-free solder SnAg3.5 was carried out by utilizing U-groove solder lines and atomic force microscopy in the temperature range of 100-150 degrees C. The drift velocity was measured, and the threshold current densities of the SnAg3.5 solder were estimated to be 4.4 x 10(4) A/cm(2) at 100 degrees C, 3.3 x 10(4) A/cm(2) at 125 degrees C, and 5.7 x 10(3) A/cm(2) at 150 degrees C. These values represent the maximum current densities that the SnAg3.5 solder can carry without electromigration damage at the three stressing temperatures. The critical products for the SnAg3.5 solder were estimated to be 462 A/cm at 100 degrees C, 346 A/cm at 125 degrees C, and 60 A/cm at 150 degrees C. In addition, the electromigration activation energy was determined to be 0.55 eV in the temperature range of 100-150 degrees C. These values are very fundamental for current carrying capability and mean-time-to-failure measurement for solder bumps. This technique enables the direct measurement of electromigration parameters of solder materials.
Microstructural evolution during electromigration in eutectic SnAg solder bumps
(2005-09-01)
Chen, YH
;
Shao, TL
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Liu, PC
;
Chen, C
;
Chou, T
Microstructural changes induced, by electromigration were studied in eutectic SnAg solder bumps jointed to under-bump metallization (UBM) of Ti/Cr-Cu/Cu and pad metallization of Cu/Ni/Au. Intermetallic compounds (IMCs) and phase transformations were observed during a current stress of 1 X 104 A/cm(2) at 150 degrees C. On the cathode/ substrate side, some of the (Cu-y,Ni1-y)(6)Sn-5 transformed into (Ni-x,Cu1-x)(3)Sn-4 due to depletion of Cu atoms caused by the electron flow. It is found that both the cathode/ chip and anode/chip ends could be failure sites. On the cathode/chip side, the UBM dissolved after current stressing for 22 h, and failure may occur due to depletion of solder. On the anode/chip side, a large amount of (Cu-y,Ni1-y)(6)Sn-5 or (Ni-x,Cu1-x)(3)Sn-4 IMCs grew at the low-current-density area due to the migration of Ni and Cu atoms from the substrate side, which may be responsible for the electromigration failure at this end.
Motion parameter estimation based on the block recursive algorithm with finite word length
(1997-11-01)
Liu, PC
;
Chang, WT
;
Shen, WZ
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電子工程學系及電子研究所
;
Department of Electronics Engineering and Institute of Electronics
Three parameter motion model can better describe the motion trajectory of picture element in video sequence. Combining the features of block process and recursive estimation, a block recursive algorithm is proposed to calculate these three motion parameters with compensating the variety of block position to get better stability. To get the simplification requirement for hardware implementation, the representation accuracy of displaced frame difference and gradient that are given is analyzed, From these analysis we propose a quantized block recursive algorithm with quantized grandient to reduce the computational complexity. With this simplification the quantized motion estimation algorithm could get sufficient computational speed to meet the requirement of real time application with the least accuracy loss.
Motion parameter estimation based on the block recursive algorithm with finite word length
(1997-11-01)
Liu, PC
;
Chang, WT
;
Shen, WZ
;
電子工程學系及電子研究所
;
Department of Electronics Engineering and Institute of Electronics
Three parameter motion model can better describe the motion trajectory of picture element in video sequence. Combining the features of block process and recursive estimation, a block recursive algorithm is proposed to calculate these three motion parameters with compensating the variety of block position to get better stability. To get the simplification requirement for hardware implementation, the representation accuracy of displaced frame difference and gradient that are given is analyzed, From these analysis we propose a quantized block recursive algorithm with quantized grandient to reduce the computational complexity. With this simplification the quantized motion estimation algorithm could get sufficient computational speed to meet the requirement of real time application with the least accuracy loss.
Recursive minimum energy algorithm for image interpolation
(1998-02-01)
Liu, PC
;
Chang, WT
;
Shen, WZ
;
電子工程學系及電子研究所
;
Department of Electronics Engineering and Institute of Electronics
An interpolation method based on the criterion to maximize the smoothness is proposed. In contrast to the conventional approach, where the interpolated signal is made smooth by low-pass filtering, in the proposed method, the smoothness is obtained by minimizing a global energy function. With the minimum energy formulation for interpolation, a recursive method is used to derive the solution and named as the recursive minimum energy algorithm. Because the smoothness is improved by increasing the calculation iteration but not by increasing the tap length, the controllability of this system is increased. Experiments show that the smoothness and the frequency performance obtained by the proposed algorithm are better than those of the conventional method. Also, the corresponding architecture design for the image interpolation is presented and shown to be suit for VLSI implemented.
Recursive minimum energy algorithm for image interpolation
(1998-02-01)
Liu, PC
;
Chang, WT
;
Shen, WZ
;
電子工程學系及電子研究所
;
Department of Electronics Engineering and Institute of Electronics
An interpolation method based on the criterion to maximize the smoothness is proposed. In contrast to the conventional approach, where the interpolated signal is made smooth by low-pass filtering, in the proposed method, the smoothness is obtained by minimizing a global energy function. With the minimum energy formulation for interpolation, a recursive method is used to derive the solution and named as the recursive minimum energy algorithm. Because the smoothness is improved by increasing the calculation iteration but not by increasing the tap length, the controllability of this system is increased. Experiments show that the smoothness and the frequency performance obtained by the proposed algorithm are better than those of the conventional method. Also, the corresponding architecture design for the image interpolation is presented and shown to be suit for VLSI implemented.
Recursive wiener filter for motion parameter estimation in three-parameter motion model
(1998-12-01)
Liu, PC
;
Chang, WT
;
資訊工程學系
;
Department of Computer Science
Motion compensation is used to reduce the displaced frame difference (DFD) during the video coding. To increase the accuracy of the point correspondence during the compensation, a three-parameter motion model is considered. The matching error can be significantly reduced as compared with that of the two-parameter block matching. To derive the parameters, a partial full search method is used. The full search is used when the zoom value is set at one. Otherwise, the gradient-based algorithm is used, Since the DFD is a nonlinear function of the image gradients and the motion parameters, a linearized model is considered. To eliminate the linearization error, Wiener filtering is used to smoothen the DFD to improve the convergence condition of the iterative gradient search. To make the gradient-based search more robust to the gradient variation, several gradient estimation methods are also compared.
Recursive wiener filter for motion parameter estimation in three-parameter motion model
(1998-12-01)
Liu, PC
;
Chang, WT
;
資訊工程學系
;
Department of Computer Science
Motion compensation is used to reduce the displaced frame difference (DFD) during the video coding. To increase the accuracy of the point correspondence during the compensation, a three-parameter motion model is considered. The matching error can be significantly reduced as compared with that of the two-parameter block matching. To derive the parameters, a partial full search method is used. The full search is used when the zoom value is set at one. Otherwise, the gradient-based algorithm is used, Since the DFD is a nonlinear function of the image gradients and the motion parameters, a linearized model is considered. To eliminate the linearization error, Wiener filtering is used to smoothen the DFD to improve the convergence condition of the iterative gradient search. To make the gradient-based search more robust to the gradient variation, several gradient estimation methods are also compared.
Tin whisker growth driven by electrical currents
(2004-06-15)
Liu, SH
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Chen, C
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Liu, PC
;
Chou, T
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材料科學與工程學系
Tin whisker growth was investigated in pure Sn using Blech structure. Blech structure was used to investigate the electromigration behavior in pure tin, in which 5000 Angstrom tin strips were on 700 Angstrom titanium films. Tin whiskers grew on the anode side, and voids were observed on the cathode side after stressing at the current densities of 7.5x10(4) and 1.5x10(5) A/cm(2) at room temperature. To investigate temperature effect, samples are stressed at room temperature and 50 degreesC. The whisker growth rates were estimated to be 3 and 7.7 Angstrom/s at room temperature and at 50 degreesC, respectively, in the current density of 1.5x10(5) A/cm(2). The whisker growth rate reduced to 0.4 Angstrom/s at the current density of 7.5x10(4) A/cm(2), which is still faster than that driven by mechanical stress. Transmission electron microscopy results showed that the whiskers are single crystalline and a thin Sn oxide formed on their surfaces. The mechanism of tin whisker growth driven by electrical force is proposed in this article. (C) 2004 American Institute of Physics.
Wafer bonding for high-brightness light-emitting diodes via indium tin oxide intermediate layers
(2005-05-01)
Liu, PC
;
Hou, CY
;
Wu, YCS
;
材料科學與工程學系
;
Department of Materials Science and Engineering
A direct wafer-bonding technique has been used to fabricate high-brightness light emitting diodes (LEDs). However, bonding processes were usually performed at elevated temperatures, possibly causing degradation in the quality of the LED structure. In addition to this, misorientation between the two bonded wafers may have caused defects between the wafers. In this study, these two problems were solved by bonding the InGaP/GaAs and GaAs wafers with an indium tin oxide (ITO) polycrystalline film at temperatures below 650 degrees C. It was found that the bonding occurred mainly through the In transport from the InGaP to ITO, and that the electrical resistance decreased with the bonding temperature. (c) 2004 Elsevier B.V. All rights reserved.
Wafer bonding using indium tin oxide intermediate layer for high brightness LEDs
(2003)
Liu, PC
;
Hou, CY
;
Wu, YCS
;
材料科學與工程學系
;
Department of Materials Science and Engineering
Direct-wafer-bonding technique has been used to fabricate high brightness light emitting diodes (LEDs). However, bonding processes were Usually performed at elevated temperatures, which may degrade the quality of the LED structure. In addition to this, the misorientation between two bonded wafers may cause defects between the wafers. In this Study, these two problems were solved by bonding the wafers with an indium tin oxide (ITO) polycrystalline film at temperature below 650 degreesC. It was found that the electrical resistance and optical loss decreased with the bonding temperature.
Wiener filter for zoom parameter estimation in three-parameter motion model
(1997)
Liu, PC
;
Shen, WZ
;
Chang, WT
;
交大名義發表
;
電子工程學系及電子研究所
From the linearized Taylor series expansion, an iterative, gradient-based method is used to estimate the zoom and pan motion parameters. In order to take into account the high order expansion error, the Wiener filtering techniques are investigated. It is shown that the expansion error can be efficiently removed with the Wiener filter. However, the reliability of the estimated parameters is still highly dependent upon the accuracy of the gradient information of the images.