Showing papers by "Kwangwoon University published in 1994"
TL;DR: In this article, the authors proposed a desired expectations model of end-user computing EUC success that describes that the success of EUC be determined by the discrepancy between end-users' desires and actual performance of information systems.
Abstract: Noting considerable alienation or dissatisfaction on the part of computer users, MIS literature has looked at a variety of social science techniques, including consumer satisfaction theory, for solutions to these problems. The dominant model of consumer satisfaction and dissatisfaction has been based on the disconfirmation of expectations paradigm. However, a critique of the disconfirmation of expectations model shows that using predictive expectation as a comparison standard reveals a number of conceptual and empirical problems. To overcome these problems, this paper suggests desired expectations as an alternative comparison standard. This paper proposes a desired expectations model of end-user computing EUC success that describes that the success of EUC be determined by the discrepancy between end-user desires and actual performance of information systems. Analysis of data from 150 end-users in Korean business firms shows that attitudinal measures of EUC success i.e., overall user satisfaction and perceived usefulness were significantly influenced by the level of discrepancy. This empirical result supports the assumption that the success of EUC depends on how end-users perceive the actual performance of information systems in the context of what they want
61 citations
TL;DR: In this article, metalorganic chemical vapor deposition of titanium dioxide (TiO2) on p-Si(100) using titanium isopropoxide and nitrous oxide via pyrolysis at relatively low (∼500 °C) temperature was performed to produce high quality TiO2/p-Si interfaces and to fabricate TiO 2 insulator gates with a dielectric constant of high magnitude.
Abstract: Metalorganic chemical vapor deposition of titanium dioxide (TiO2) on p‐Si(100) using titanium isopropoxide and nitrous oxide via pyrolysis at relatively low (∼500 °C) temperature was performed to produce high quality TiO2/p‐Si interfaces and to fabricate TiO2 insulator gates with a dielectric constant of high magnitude. Scanning electron microscopy shows that the surfaces of the TiO2 films have very smooth morphologies. From the x‐ray diffraction analysis, the grown layer was found to be a polycrystalline film. Raman spectroscopy showed the optical phonon modes of a TiO2 thin film. The stoichiometry of the TiO2 film was investigated by Auger electron spectroscopy. Room‐temperature current‐voltage and capacitance‐voltage measurements clearly revealed metal‐insulator‐semiconductor behavior for the samples of the Ag/TiO2/p‐Si. The interface state density at the TiO2/p‐Si interface was approximately high 1011 eV−1 cm−2 at the middle of the Si energy gap, and the dielectric constant determined from the capacitance‐voltage measurements was as large as 73. These results indicate the TiO2 layers grown at relatively low temperature can be used for high density dynamic memory.
41 citations
20 citations
TL;DR: In this paper, a variety of neutral carrier-type ionophores were employed to prepare cation-selective electrodes for use as a detector in single-column ion chromatography, and a polymer membrane electrode doped with a new siloxane-based bis-crown ether exhibited similar selectivity to ammonium and all alkali metal ions except lithium.
13 citations
TL;DR: A new solvent/polymeric multiion-selective membrane electrode is described for use as a flow-through detector in ion chromatography, prepared by incorporating four different neutral-carrier ionophores in a strongly adhesive polyurethane matrix.
Abstract: A new solvent/polymeric multiion-selective membrane electrode is described for use as a flow-through detector in ion chromatography. Unlike conventional ion-selective membranes that utilize only one type of ionophore, the multiion-selective membranes incorporate several different ionophores. In this study, a K+iNH,+/Na+/Ca*+ selective membrane has been prepared by incorporating four different neutral-carrier ionophores in a strongly adhesive polyurethane matrix. This membrane is cast on solid electrode surfaces, with no internal electrolyte solution, to form solid-state multiion sensors. The detection characteristics of the muhiionophore membranes, which are controlled by the amounts and ratios of the ionophores they contain, are examined in a flow-injection arrangement. The sensors have been demonstrated in the target application, a flow-through ion chromatography system.
13 citations
TL;DR: In this paper, metal-organic chemical vapor deposition of TiO 2 via pyrolysis using Ti (OC 3 H 7 ) 4 and N 2 O was investigated with the goal of producing a polycrystalline film on p-Si(100) substrates.
13 citations
TL;DR: In this paper, a three-terminal MESFET with gate depletion capacitance Cg was used to produce 10.17 dBm output power at a frequency of 11.00 GHz and tuning bandwidth of 70.2 MHz.
Abstract: The MESFET can be used as a three-terminal MESFET varactor by employing gate depletion capacitance Cg. Using this concept, a new VCDRO (voltage controlled dielectric resonator oscillator) has been designed. The VCDRO produced 10.17 dBm output power at a frequency of 11.00 GHz and tuning bandwidth of 70.2 MHz. The advantage of using the MESFET as a three-terminal varactor is to let the MESFET perform both roles at the same time, thus simplifying the circuit configuration and fabrication. This finding demonstrates the potential of using both real and imaginary parts of the equivalent impedance of the active device.
12 citations
TL;DR: In this paper, an approach to kinematics and dynamics based on kinematic influence coefficient matrices is proposed for applications to the analysis and control of motion controlled multibody systems, e.g., hybrid robotic manipulator systems.
Abstract: An approach to kinematics and dynamics based on kinematic influence coefficient matrices is proposed for applications to the analysis and control of motion controlled multibody systems, e.g., hybrid robotic manipulator systems. The scheme is unique in a sense that all the kinematic constraints are completely embedded into the formulations at the kinematics level and equation of motion of the system is obtained in a closed form with respect to the minimal set of independent joint coordinates. Furthermore, all kinematic and dynamic formulations are expressed compactly in the same format by using two special algebraic operators. This isomorphic formalism allows systematic transformations of kinematic and dynamic informations between different sets of coordinates in a purely algebraic way.
6 citations
TL;DR: In this article, the subband energies of edge delta-doped Al0.27Ga0.73As/GaAs single quantum well were determined using a self-consistent numerical method taking into account the exchange correlation effects.
Abstract: Shubnikov–de Haas and Van der Pauw Hall effect measurements at 1.5 K have been carried out to investigate the existence of a two‐dimensional electron gas and to determine subband energies in a Si‐delta‐doped Al0.27Ga0.73As/GaAs single quantum well. The fast Fourier transformation results for the S‐dH data indicate clearly the occupation of two subbands in edge delta‐doped Al0.27Ga0.73As/GaAs quantum wells. Capacitance‐voltage profiling and temperature‐dependent photoluminescence measurements have been performed to characterize the properties of edge delta‐doped Al0.27Ga0.73As/GaAs quantum wells. Using these experimental results and a self‐consistent numerical method which took into account the exchange‐correlation effects, the electron subband energies were determined. These results indicate that edge delta‐doped Al0.27Ga0.73As/GaAs single quantum wells are similar to the asymmetrical potential wells occupied by relatively high electron carrier densities.
5 citations
TL;DR: In this paper, photoluminescence (PL) and Raman spectroscopy measurements on GaAs/Si heterostructures grown by molecular beam epitaxy were performed in order to characterize the optical properties of the samples after thermal treatment.
5 citations
14 Nov 1994
TL;DR: In this paper, the MESFET can be used as a three-terminal MES-FET varactor by employing the gate depletion capacitance Cg, and a new VCDRO (voltage controlled dielectric 0.0 resonator oscillator) is designed.
Abstract: The MESFET can be used as a three-terminal MESFET varactor by employing the gate depletion capacitance Cg. A new VCDRO (voltage controlled dielectric 0.0 resonator oscillator) is designed to apply VCDRO with this concept. The VCDRO produced 10.17 dBm output power at a frequency of 11.00 GHz and tuning bandwidth of 70.2 MHz. The advantage of using the MESFET as a three-terminal varactor is to let the MESFET play both roles at the same time, thus simplifying the circuit configuration and fabrication. This finding demonstrates the potential of using both real and imaginary parts of the equivalent impedance of the active device. >
TL;DR: In this paper, the effects of annealing and hydrogenation on the defect levels of NTD GaAs were investigated, and it was shown that the defects in the annealed GaAs are compensated by hydrogen atoms after hydrogenation.
Abstract: Photoluminescence and photoreflectance measurements are carried out in order to investigate the effects of annealing and hydrogenation on the defect levels of neutron-transmutation-doped (NTD) GaAs. The damage to the crystallinity of NTD GaAs is recovered by annealing, and the defects in the annealed NTD GaAs are compensated for by hydrogen atoms after hydrogenation. Since the transmutation-doped impurities in GaAs are compensated for by the injection of hydrogen atoms, Franz-Keldysh oscillations appear due to the large variation in the surface electric field.
TL;DR: In this article, the defect levels of NTD GaAs due to annealing and hydrogenation were investigated, and it was shown that the defect complex center is passivated by thermal treatment and hydrogenization.
Abstract: Photoluminescence measurements are carried out in order to investigate the effects on the defect levels of neutron-transmutation-doped (NTD) GaAs due to annealing and hydrogenation. The peak intensity corresponding to the transition from the conduction band to the Ge acceptor [Ge(B–A)] increases at an annealing temperature of 600°C, and then decreases remarkably around a temperature of 650°C; on the other hand, the peak intensity of the defect complex peak increases at 600°C. After annealing and subsequent hydrogenation, the peak of the transitions between the band and the carbon acceptors [C(B–;A)] is resolved clearly into the C(B–A) and Ge(B–A) peaks, and the intensity of the peak corresponding to the As vacancy and carbon complex center on As sites decreases remarkably. These results indicate that the crystallinity of the NTD GaAs is improved by annealing and hydrogenation and that the defect complex center is passivated by thermal treatment and hydrogenation.
TL;DR: In this paper, the van der Pauw Hall effect measurements on In0.53 Ga 0.47As/In0.52Al 0.48As heterointerfaces have been carried out to investigate the magnetotransport properties of an electron gas and to determine the subband energies and wavefunctions in a single quantum well.
Abstract: Shubnikov-de Haas (SdH) and van der Pauw Hall effect measurements on In0.52Al0.48As/In0.53Ga0.47As/In0.52Al$ d0.48As one-side modulation-doped quantum wells grown by metalorganic chemical vapour deposition have been carried out to investigate the magnetotransport properties of an electron gas and to determine the subband energies and wavefunctions in a single quantum well. Transmission electron microscopy measurements show that the In0.53 Ga0.47As/In0.52Al0.48As heterointerfaces have a perfect lattice match. The SdH measurements at 1.5 K have demonstrated clearly the existence of a quasi-two-dimensional electron gas in the quantum well. The fast Fourier transformation results for the SdH data indicate clearly the occupation of two subbands in the In0.53Ga0.47As single quantum well. Electron energy subbands in the quantum well were calculated by a self-consistent method taking into account exchange-correlation effects and making use of the experimentally determined carrier density.
01 Mar 1994
TL;DR: A new optical binary phase extraction joint transform correlator (BPEJTC) is used to reduce the massive input target data into a few correlation peak signals and a parallel computational neural network is used for effective target tracking data association based on these correlation signals.
Abstract: In this paper, we present an OptoNeural approach to the problem of multitarget tracking. The proposed hybrid OptoNeural system uses a new optical binary phase extraction joint transform correlator (BPEJTC) to reduce the massive input target data into a few correlation peak signals. A parallel computational neural network is then used for effective target tracking data association based on these correlation signals. For real-time operation, the BPEJTC is optically implemented using the high resolution LCD spatial light modulators and CCD detectors. Some experimental results on simultaneous tracking of multitargets are also provided.© (1994) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.
07 Sep 1994
TL;DR: In this article, TSC spectroscopy was applied to investigate an influence of structural change and interfacial state on the electrical properties of epoxy composites cured with acid-anhydride.
Abstract: The TSC spectroscopy was applied to investigate an influence of structural change and interfacial state on the electrical properties of epoxy composites cured with acid-anhydride. A addition of over abundant hardener and inorganic filler separated a /spl beta/ peak near 10[/spl deg/C] into two peaks of /spl beta//sub 1/(10/spl deg/C) and /spl beta//sub 2/(20/spl deg/C) and increased magnitude of TSC spectra between /spl alpha/ and /spl beta/ peak, which would be closely related with the process of thermal oxidation and separation of hardener's phenyl group according to an introduction of interfacial deformation, an expansion of free volume and a reduction of structural packing density. And the treatment of silane coupling agents on filler improved interfacial deformation to decrease the amplitude of TSC spectra.
TL;DR: In this article, the interaction dynamics for a cyclotron autoresonance maser oscillator in its nonlinear saturation regime was studied in a highly relativistic limit of electron energy, such that the longitudinal beam velocity approaches to the speed of light.
Abstract: The interaction dynamics for a cyclotron autoresonance maser oscillator is studied in its nonlinear saturation regime. In a highly relativistic limit of electron energy, such that the longitudinal beam velocity approaches to the speed of light, the dynamics has a sensitive dependence on the longitudinal phase velocity of the radiation field. We investigate the dynamic variations and their consequences on the saturation efficiency, in a range that the phase velocity is slightly greater than the free space value. It is observed that, for an appropriate value of the phase velocity, the potential bucket in the phase space expands to a maximal area. Consequential enhancement of the nonlinear saturation efficiency is estimated. >
24 Jul 1994
TL;DR: In this article, the Monte-Carlo method is used to simulate individual particles through their successive collisions with resist atoms, and the distribution for the range parameters of primary and recoiled ions and the energy dissipation profiles for various ion beam energies are evaluated.
Abstract: Summary form only given. The bilayer film of Ag/a-Se/sub 75/Ge/sub 25/ and the monolayer film of a-Se/sub 75/Ge/sub 25/ act as a negative and a positive resist in ion beam lithography, respectively. We have discussed the numerically calculated values such as ion range, ion concentration and ion transmission coefficient, and the defocused Ga/sup +/ ion-induced characteristics in inorganic resists. Monte-Carlo method is based on the simulation of individual particles through their successive collisions with resist atoms. By the summation of the scattering events occurring in a large number N(N/spl Gt/1000) of simulated trajectories within the resist, the distribution for the range parameters of primary and recoiled ions and the energy dissipation profiles for various ion beam energies are evaluated. Also this text contains the exposure and development results.
03 Jul 1994
TL;DR: In this article, the influence of structural change and interfacial state on the electrical properties of epoxy composites cured with acid-anhydride was investigated by thermal stimulated current spectroscopy.
Abstract: Thermally stimulated current spectroscopy was applied to investigate the influence of structural change and interfacial state on the electrical properties of epoxy composites cured with acid-anhydride. A overabundantly added hardener separated a /spl beta/ peak near 10[/spl deg/C] into two peaks of /spl beta//sub 1/(10/spl deg/C) and /spl beta//sub 2/(20/spl deg/C). Filling with an inorganic filler increased the magnitude of TSC between the /spl alpha/ and /spl beta/ peaks and lowered T/sub g/. Silan coupling agents on the filler improved interfacial deformation, decreasing TSC. >
29 Sep 1994
TL;DR: It is shown that a 2D OCDMA network using costas array allows shorter bit times, for a given laser pulse width, and 2D codes as a cost as array result in a reduction of autocorrelation sidelobes and crosscorrelation peaks, and this network has lower losses compared to the 1D OCD MA network.
Abstract: In this paper, 2D optical code division multiple access (OCDMA) networks based on the costas array are compared with the 1D OCDMA networks through the computer simulation and some simulation results are also provided. It shows that a 2D OCDMA network using costas array allows shorter bit times, for a given laser pulse width, and 2D codes as a costas array result in a reduction of autocorrelation sidelobes and crosscorrelation peaks, and this network has lower losses compared to the 1D OCDMA network.© (1994) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.
03 Jul 1994
TL;DR: In this paper, the electrical properties of polypropylene films are obtained from TSC measurement after corona charging between copper knife electrode and aluminium cylinder electrode with the voltages of -8, -7, -6, and -5 [kV], respectively.
Abstract: In order to estimate space charging process in the corona charging apparatus which has been used to make polymer electret cells, the electrical properties of 30[/spl mu/m] thickness polypropylene films are obtained from TSC measurement after corona charging between copper knife electrode and aluminium cylinder electrode with the voltages of -8, -7, -6, and -5 [kV], respectively. The electrostatic contour and the electric field vector are calculated using finite element method with the electrical properties obtained from TSC spectra analysis. The edge effect around the edge of the knife electrode affects the electrostatic contour on the surface of the specimen and the electric field concentration inside the polymer. As a result, the uneven charging state in the electret cell due to the design error is calculated, and the optimal design of corona charging apparatus appropriate to various specimens is made practicable. >
TL;DR: In this paper, the structural properties of single crystalline CoGa grown by molecular beam epitaxy on a GaAs substrate were investigated using transmission electron microscopy, and the results showed that the crystal orientation relationships between the CoGa epilayer and the substrate were [1 1 0]CoGa | [1 0]GaAs and (0 0 1)CoGa| (1 1 1 0)GaAs.
TL;DR: Shubnikov-de Haas, Van der Pauw Hall-effect, and Raman spectroscopy measurements on In 0.53 Ga 0.47 As single quantum well have been carried out to investigate the magnetotransport and optical properties of an electron gas.