Browsing by Author "Huang, C"

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A new technique to extract oxide trap time constants in MOSFET's
(1996-08-01)
Wang, TH
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Chang, TE
;
Chiang, LP
;
Huang, C
;
電子工程學系及電子研究所
A new technique to determine oxide trap time Constants in a 0.6 mu m n-MOSFET subject to hot electron stress has been proposed, In this method, we used GIDL current as a direct monitor of the oxide charge detrapping-induced transient characteristics. An analytical model relating the GIDL current evolution to oxide trap time constants was derived, Our result shows that under a field-emission dominant oxide charge detrapping condition, V-gs = -4 V and V-ds = 3 V, the hot electron stress generated oxide traps exhibit two distinct time constants from seconds to several tens of seconds.
A new technique to measure an oxide trap density in a hot carrier stressed n-MOSFET
(1997)
Wang, TH
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Chiang, LP
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Chang, TE
;
Zous, NK
;
Shen, KY
We have proposed a new measurement technique to characterize the hot carrier stress generated oxide traps in a n-MOSFET by measuring subthreshold current. In this technique, a specially designed measurement consisting of a series of oxide charge detrapping and subthreshold current measurement phases was performed. An analytical model accounting for the temporal evolution of subthreshold current due to oxide charge detrapping was derived. Our study shows that this method is extremely sensitive to an oxide charge variation. By using this method, the oxide trap growth rates by hot electron stress and hot hole stress were measured.
A novel adaptive video playout control for video streaming over mobile cellular environment
(2005)
Chuang, HC
;
Huang, C
;
Chiang, T
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電子工程學系及電子研究所
;
Department of Electronics Engineering and Institute of Electronics
Video streaming is becoming one of the potential killer applications in a mobile service network. MPEG-4 Fine-Granularity Scalabitity is proposed to significantly increase the flexibility for video transmission. However, the bottleneck of bandwidth often occurs in the last-mile transmission from the base station to the mobile device, which incurs quality degradation. Adaptive Media Playout (AMP) is a receiver-based technique that could eliminate the buffer outage and hence improve the associated visual quality. This paper addresses the issue of AMP control utilized in a mobile cellular environment. Specifically, we propose a novel AMP control that could further improve the visual quality compared to other conventional AMP controls. Experimental results demonstrate the proposed control provides better visual quality with a low complexity.
Characteristics of MOCVD- and MBE-grown InGa(N)As VCSELs
(2005-08-01)
Yang, HPD
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Lu, C
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Hsiao, R
;
Chiou, C
;
Lee, C
We report our results on InGaNAs/GaAs vertical-cavity surface-emitting lasers (VCSELs) in the 1.3 mu m range. The epitaxial structures were grown on (10 0) GaAs substrates by metalorganic chemical vapour deposition (MOCVD) or molecular beam epitaxy (MBE). The nitrogen composition of the InGa(N)As/GaAs quantum-well (QW) active region is 0-0.02. The long-wavelength (up to 1.3 mu m) room-temperature continuous-wave (RT CW) lasing operation was achieved for MBE- and MOCVD-grown VCSELs. For MOCVD-grown devices with n- and p-doped distributed Bragg reflectors (DBRs), a maximum optical output power of 0.74 mW was measured for In(0.36)Ga(0.64)N(0.006)AS(0.994)/GaAs VCSELs. A very low J(th) of 2.55 kA cm(-2) was obtained for the InGaNAs/GaAs VCSELs. The MBE-grown devices were made with an intracavity structure. Top-emitting multi-mode 1.3 mu m In0.35Ga0.65N0.02As0.98/GaAs VCSELs with 1 mW output power have been achieved under RT CW operation. A J(th) of 1.52 kA cm-2 has been obtained for the MBE-grown In0.35Ga0.65N0.02As0.98/GaAs VCSELs, which is the lowest threshold current density reported. The emission characteristics of the InGaNAs/GaAs VCSELs were measured and analysed.
Characterization of various stress-induced oxide traps in MOSFET's by using a novel transient current technique
(1997)
Wang, TH
;
Chiang, LP
;
Zous, NK
;
Chang, TE
;
Huang, C
A new oxide trap characterization technique by employing a two-phase subthreshold current measurement has been developed. By varing the gate bias and the drain bias in measurement, the field and temperature dependences of oxide charge detrapping and the spatial distributions of various stress induced oxide traps are characterized.
Characterization of various stress-induced oxide traps in MOSFET's by using a subthreshold transient current technique
(1998-08-01)
Wang, TH
;
Chiang, LP
;
Zous, NK
;
Chang, TE
;
Huang, C
An oxide trap characterization technique by measuring a subthreshold current transient is developed, This technique consists of two alternating phases, an oxide charge detrapping phase and a subthreshold current measurement phase. An analytical model relating a subthreshold current transient to oxide charge tunnel detrapping is derived. By taking advantage of a large difference between interface trap and oxide trap time-constants, this transient technique allows the characterization of oxide traps separately in the presence of interface traps, Oxide traps created by three different stress methods, channel Fowler-Nordheim (F-N) stress, hot electron stress and hot hole stress, are characterized, By varying the gate bias in the detrapping phase and the drain bias in the measurement phase, the field dependence of oxide charge detrapping and the spatial distribution of oxide traps in the channel direction can be obtained, Our results show that 1) the subthreshold current transient follows a power-law time-dependence at a small charge detrapping field, 2) while the hot hole stress generated oxide traps have a largest density, their spatial distribution in the channel is narrowest as compared to the other two stresses, and 3) the hot hole stress created oxide charges exhibit a shortest effective detrapping time-constant.
Comment on "Application of Aspergillus oryzae and Rhizopus oryzae for Cu(II) removal" - Author's reply
(1998-01-01)
Huang, C
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Huang, CP
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環境工程研究所
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Institute of Environmental Engineering
Comment on "Application of Aspergillus oryzae and Rhizopus oryzae for Cu(II) removal" - Author's reply
(1998-01-01)
Huang, C
;
Huang, CP
;
環境工程研究所
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Institute of Environmental Engineering
Competitive adsorption of ferricyanide and ferrocyanide on gamma-Al2O3 surface
(2000-04-15)
Cheng, WP
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Huang, C
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Chien, YC
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環境工程研究所
;
Institute of Environmental Engineering
In the past 3 decades, research has proven the significance of competitive adsorption in the equilibrium of pollutants between solid and liquid phases. However, studies on the competitive adsorption of complex ions are very limited in spite of its important role in transporting pollutants in the natural environment. The objective of this study is to derive the thermodynamic parameters of the competitive adsorption between ferricyanide and ferrocyanide from the modified Langmuir isotherm and the triple-layer model (TLM) to determine the location of adsorption. The effects of pH, temperature, and ion concentration on competitive adsorption onto gamma-Al2O3 were investigated. The results demonstrate that ferrocyanide is more competitive than ferricyanide. By comparing the derived K-app with K-int, we inferred that the adsorption of ferricyanide and ferrocyanide onto gamma-Al2O3 was achieved through outer-sphere complexation. The negative Delta H-3 indicated that the adsorption was exothermic, The positive entropy (Delta S degrees) was caused by the replacement and release of a greater number of smaller surface ions by adsorbed ferricyanide and ferrocyanide ions of larger size. (C) 2000 Academic Press.
Effect of surfactant on alum sludge conditioning and dewaterability
(2000)
Pan, JRS
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Huang, C
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Fu, CG
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環境工程研究所
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Institute of Environmental Engineering
Sludge disposal has become a new challenge for the Taiwan government due to the increasing demand for better quality and greater quantity of water. in some water treatment plants, surfactant has been applied in the flotation process to improve ifs performance, which suggests the use of surfactant in sludge conditioning. In this study. effects of surfactants on the conditioning of the alum sludge collected from Feng-Yuan Water Treatment Plant were investigated. Surfactants of various charges, namely CTAB and SDS, were added to sludge samples in various amounts, and their effects on sludge dewaterability were evaluated. Surfactants were also added with either cationic or anionic polymers to better understand their effects on the mechanism of sludge conditioning and the feasibility as coagulant aid. Experimental results indicate that applying surfactants alone in sludge system decrease the filterability of sludge, but increase the sludge dewatering rate at optimum dosage. Cationic surfactant was proven possible as conditioning aid for the cationic polymer. The order of surfactant and polymer addition is the key to additive function. On the other hand, when the polymer of opposite charge was added with the surfactant, co-precipitation occurred which resulted in decreased filterability and dewaterability.
Effects of surfactant addition on dewatering of alum sludges
(2002-12-01)
Huang, C
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Pan, JR
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Fu, CG
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Wu, CC
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環境工程研究所
In Taiwan, surfactants are frequently used in the flotation process to aid in solid/liquid separation. Their effect on the dewatering of alum sludge was investigated. Various amounts of cationic and anionic surfactants were added to sludge samples, and the dewatering characteristics of the sludge and the water content of sludge cakes were evaluated. Both surfactants improved the dewatering of the sludge by lowering the specific resistance to filtration, decreasing the bound water content, and increasing the dewatering rate of the sludge. Different combinations of anionic and cationic surfactants and polyelectrolytes were also experimented on to study the effect of surfactant addition on the dewatering characteristics of polyelectrolyte-conditioned sludge. Experimental results indicated that both cationic and anionic surfactants adversely affected the dewatening of the conditioned sludge. The addition of surfactant to the oppositely charged polyelectrolyte proved to be most detrimental to sludge dewatering due to the precipitation between surfactant and polyelectrolyte. The addition of cationic surfactant to the cationic polyelectrolyte-conditioned sludge had the least effect.
Examination of Giardia and Cryptosporidium in water samples and fecal specimens in Taiwan
(2000)
Hsu, BM
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Huang, C
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Hsu, YF
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Hsu, CLL
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環境工程研究所
Giardia and Cryptosporidium have emerged as waterborne pathogens of concern over the past few decades. Twenty-nine source water samples were collected from water treatment facilities and checked for the occurrence of Giardia and Cryptosporidium along with some water quality parameters. These facilities include ten large-scale treatment plants near major metropolitan areas, and eight simple facilities in small and secluded communities. The indirect immunofluorescence assay (IFA) was used for the detection of cysts and oocysts in water samples. In addition, fecal specimens were collected from watersheds providing source water for the treatment plants, and the presence of Giardia and Cryptosporidium was detected with the enzyme-linked immunosorbent assay (EIA). The mean concentrations of protozoa in large-scale plants were 66.8 cysts/100 litres and 89.2 oocysts/100 litres, while simple facilities contained 1.27 cysts/100 litres and 0.28 oocysts/100 litres, respectively. The concentrations of these two parasites exhibit the highest correlation with turbidity than any other water quality parameters. Among the 101 fecal specimens, eleven were positive for Giardia and 22 were positive for Cryptosporidium. It was also found that the occurrence of these two pathogens in the source water was directly linked to the surrounding farming activities, suggesting that farming activities should be kept at a certain distance from the watersheds.
Field and temperature effects on oxide charge detrapping in a metal-oxide-semiconductor field effect transistor by measuring a subthreshold current transient
(1997-08-25)
Chiang, LP
;
Zous, NK
;
Wang, TH
;
Chang, TE
;
Shen, KY
A technique to characterize oxide charge detrapping in a Fowler-Nordheim stressed n-metal-oxide-semiconductor field effect transistor is proposed. This technique consist of two alternating phases, an oxide charge detrapping phase and a subthreshold current measurement phase. An analytical model relating a subthreshold current transient to oxide charge density and detrapping time constants was derived. By varying the gate bias in the detrapping phase and the ambient temperature, the field and temperature dependences of oxide charge detrapping can be obtained from the subthreshold current transients measured. (C) 1997 American Institute of Physics.
Field enhanced oxide charge detrapping in n-MOSFET's
(1996)
Wang, TH
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Chang, TE
;
Chiang, LP
;
Huang, C
;
電子工程學系及電子研究所
Investigation of oxide charge trapping and detrapping in a n-MOSFET
(1997)
Wang, TH
;
Chang, TE
;
Chiang, LP
;
Zous, NK
;
Huang, C
Oxide hole and electron trapping/detrapping characteristics in a hot carrier stressed n-MOSFET were investigated by monitoring the temporal evolution of band-to-band tunneling current. Both the hole and electron detrapping induced GIDL current transients were observed for the first time in the same device. The obtained field dependence of oxide charge detrapping time indicates that trapezoidal barrier tunneling is a major mechanism in both hole and electron detrapping. A trap assisted sequential tunneling model for hole detrapping was used to match the measured trap time constants.
Large earthquake-triggered landslides and mountain belt erosion: The Tsaoling case, Taiwan
(2005-09-01)
Chen, RF
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Chan, YC
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Angelier, J
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Hu, JC
;
Huang, C
The 1999 Chi-Chi earthquake triggered the catastrophic Tsaoling landslide in central Taiwan. We mapped the landslide area and estimated the landslide volume, using high-resolution digital elevation model from airborne LiDAR (Light Detection and Ranging), satellite images, aerial photographs and topographic maps. The comparison between cut and fill volumes, about 0.126 and 0.150 km(3), respectively, suggests a volume increase of 19% due to decompaction during landsliding. In April 2002, the cut and fill volumes were about 0.137 and 0.116 km(3), respectively. These estimates suggest that 2.5 years after the event, the volume of landslide debris removed by river erosion was nearly 0.045 km(3). Such a large value highlights the importance of landslide processes for erosion and long-term denudation in the Taiwan mountain belt.
Nano silica removal from IC wastewater by pre-coagulation and microfiltration
(2004)
Huang, C
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Jiang, W
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Chen, C
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環境工程研究所
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Institute of Environmental Engineering
Microfiltration (MF) coupled with pretreatment by coagulation was adopted in the treatment of chemical mechanical polishing (CMP) wastewater from IC manufacturing plants, containing high concentrations of silica. Poly-aluminium chloride (PACI) was the coagulant, while the cationic polyacrylamide (PAA) was the flocculant aid. Preliminary tests were performed with the raw CMP wastewater in order to determine the optimal coagulation condition for subsequent microfiltration. Analysis of the particle size distribution shows that nearly all silica particles were enlarged from nano scale to at least 4 mum in diameter after the pre-treatment. The pre-treated wastewater was then filtered through a polytetrafluoroethylene (PTFE) membrane with a pore size 0.5 mum at a constant vacuum pressure. Trace amounts of PAA in addition to the PACI coagulation can effectively increases the permeate flux.
On the buffer dynamics of scalable video streaming over wireless network
(2004)
Chuang, HC
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Huang, C
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Chiang, TH
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電子工程學系及電子研究所
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Department of Electronics Engineering and Institute of Electronics
3G mobile standard offers unprecedented high speed digital service that can carry multimedia traffics such as video streaming. The distributed system buffers in the conventional client-server architecture absorb the fluctuations of channel conditions such as bit rate variations, delays and jitters. To enable easy control for the 3G system, MPEG committee is developing scalable video coding technology that provides flexibility for transmission over wireless networks. This paper will address issues in controlling these buffers that can impact and benefit the end-to-end system performance using the novel scalable video technology. specifically, we will explore the effects of diverse channel characteristics on the buffers performance tolerance, and its impact on the quality of service. A novel model-based Adaptive Media Playout (AMP) buffer control is proposed to mitigate the risks of buffer outage.
Parameter optimization and design aspect for electrocoagulation of silica nano-particles in wafer polishing wastewater
(2006)
Den, W
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Huang, C
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環境工程研究所
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Institute of Environmental Engineering
A systematic procedure has been proposed for the design of a multi-channel, continuous-flow electrocoagulation reactor of mono-polar configuration for the removal of sub-micron particles from wastewater. Using the chemical-mechanical-planarization (CMP) process as the target source of wastewater, a series of laboratory-scale studies were conducted to determine the required operating conditions for the efficient removal of the ultrafine particles. These operating criteria included charge loading ( >= 8 F m(-3)), current density ( >= 5.7 A m(-2)), hydraulic retention time ( >= 60 min), as well as the initially operational pH (7 similar to 10). Furthermore, a steady-state transport equation with second-order reaction kinetics was employed to describe the rate of coagulation as the rate-limiting factor, The actual kinetic constant determined from the laboratory-scale experiments was approximately 1.2 x 10(-21) m(3) s(-1), which was three orders of magnitude smaller than that calculated based on Brownian diffusion during the coagulation. The model was subsequently validated with a series of experiments using a pilot-scale electro-coagulation reactor geometrically similar to the laboratory-scale reactor with nearly twenty times volumetric scale-up.
Polymer dose effects on filtration followed by expression of clay slurries
(1997-01-15)
Chang, IL
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Chu, CP
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Lee, DJ
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Huang, C
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環境工程研究所
Filtration followed by expression characteristics of cationic polymer conditioned clay slurries are reported for the first time in this work. As the polymer dosage increases, the resistance to filtration greatly decreases until a specific dose has been reached, where the zeta potential is close to zero. And further increase in polymer dose conversely raises the resistance. The expression data are interpreted by the Terzaghi-Voigt combined model, from which the model parameters are evaluated. The polymer conditioning has only a mild effect on the primary consolidation process but has, however, a considerable influence on secondary consolidation characteristics. When zeta potential changes from negative to positive, both the easiness of creeping of constituent particles within the sludge cake and the fraction of moisture removal by the secondary consolidation attain a maximum., The optimal polymer dose criterion considering the filtration and expression stages separately, or in combination, is (sic). (C) 1997 Academic Press