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21.
A banked-promotion translation lookaside buffer system 总被引:1,自引:0,他引:1
We present a simple but high performance translation lookaside buffer (TLB) system with low power consumption for use in embedded systems. Our TLB structure supports two page sizes dynamically and selectively to achieve high performance with low hardware cost. To minimize power consumption, a banked-TLB is constructed by dividing one fully associative (FA) TLB space into two separate FA TLBs. These two structures are integrated to form a banked-promotion (BP) TLB. Promotion overcomes the unbalanced utilization of a banked-TLB by moving adjacent entries out of the primary banks into a separate super-page TLB. Simulation results show that the Energy*Delay product can be reduced by about 99.8%, 19.2%, 24.2%, and 24.4% compared with a FA TLB, a micro-TLB, a banked-TLB, and a victim-TLB respectively. Therefore, the BP TLB offers high performance with low power consumption and low hardware cost. 相似文献
22.
Jung-Hoon Song Seung-Jae You Dong Hyup Jeon 《Journal of Applied Electrochemistry》2014,44(9):1013-1023
The thermal behavior of pouch-type lithium-ion batteries during discharge and charge cycles is investigated by numerical simulation. A transient thermal model using finite element method software is developed through the modification of an electrochemical-thermal model. The developed model is validated with experimental data. For the experiment, a 304252 pouch cell is fabricated and tested in the laboratory. This model captures the dynamic responses of temperature, and distributions of current density and temperature, during discharge and charge cycles. Our results indicate that the discharge temperature is higher than the charge temperature at cut-off voltage. The temperature distribution upon discharge is similar to that of charge. On the other hand, different temperature distributions are observed at various C rates. The temperature profiles obtained from modeling and experiment are in good agreement. 相似文献
23.
Christian H. Passow Jung-Hoon Chun Teiichi Ando 《Metallurgical and Materials Transactions A》1993,24(5):1187-1193
An apparatus capable of producing and depositing uniform droplets (100 to 200 μm in diameter) was developed and used to study
the relationship between spray deposition parameters and the microstructures of Sn-40 wt pct Pb alloy spray deposits. The
sprays used in the study consisted of uniform droplets, either 103 or 178 μm in diameter, that were in identical thermal and
solidification states as they impacted the substrate. The thermal and solidification states of the uniform droplets were determined
as a function of the flight distance (the distance from the metal pouring orifice) by model calculations and calorimetric
measurements assuming equilibrium solidification. Although a fair agreement was noted between the model and the calorimetric
measurements at small flight distances, corresponding to large liquid fractions, the calorimetric measurements indicated 10
to 20 pct higher liquid fractions at larger flight distances. The resultant microstructures comprised either a mixture of
the Pb-rich and Sn-rich phases, both in an equiaxed morphology, or a lamellar eutectic structure with a small amount of the
Pb-rich primary phase in a coarse spherical morphology. The mostly lamellar eutectic structure resulted from an excessive
enthalpy flux and/or slow heat extraction from the deposit. Fine, equiaxed, two-phase microstructures and high deposit density
resulted from optimal combinations of droplet enthalpy, deposition rate, droplet size, and deposit cooling rate which gave
short local solidification times. 相似文献
24.
Adsorption equilibrium and kinetics of polyvinyl alcohol from aqueous solution on powdered activated carbon 总被引:4,自引:0,他引:4
In this study, powdered activated carbon (PAC) was used to remove polyvinyl alcohol (PVA) from the aqueous PVA solution. The adsorption kinetics has been studied pertaining to various initial PVA concentration and PAC dosage. The rates of adsorption were found to conform to the second-order kinetics with good correlation. Boyd plot confirmed that external mass transfer was the rate-limiting step in the sorption process. The adsorption isotherm obtained resembled with H-type of isotherm, which indicated a high affinity of the solute for the sorption sites. The Freundlich model appeared to fit the isotherm data better than the Langmuir model. The thermodynamic parameters such as Delta H degrees , Delta S degrees and Delta G degrees were evaluated from the slope and intercept of linear plot of log Kc against (1/T) x 1000. The change in entropy (DeltaS degrees ) and heat of adsorption (Delta H degrees ) of PAC was estimated as 1.45 kJ mol(-1)K(-1) and 365 kJ mol(-1), respectively. The free energy of the adsorption at all temperatures was negative indicating a spontaneous process. The maximum PVA removal of 92% was obtained at a pH of 6.3 and contact time of 30 min for an adsorbent dose of 5 g/L. 相似文献
25.
Jung-Hoon Lim Choong-Hyo Park Jong-Wook Kim Seong-Su Jeong Myong-Ho Kim Tae-Gone Park 《Journal of Electroceramics》2013,30(1-2):108-112
The dependence of the generation characteristics of a cross-shaped piezoelectric generator on the material and leg length of the elastic body was studied. The generator consisted of a centrosymmetric thin cross-shaped elastic body and four rectangular piezoelectric ceramics that were attached to the upper surfaces of the four legs of the elastic body. Vibrations from a vibrating source were applied to the center of the elastic body. The centrosymmetric structure of the cross-shaped generator guarantees more stable and multiplied generation than a cantilever-type generator since the four legs of the generator resonate at the same frequency. The resonance and output characteristics of the generator were analyzed by using a finite element method (FEM) program. Generators were fabricated on the basis of analysis results and attached to a frequency controllable vibrator for determining their output characteristics. Further, experimental results were compared with simulated results. The speed of sound in the materials depends on the Young’s modulus and density of the materials. Accordingly, the resonance frequency of the generator decreased with a decrease in the velocity of sound in the material. The resonance frequency of the generator also decreased with an increase in the leg length. By changing the generator parameters, the resonance frequency of the generator can be controlled. 相似文献
26.
Dong-Suk KangHyo Sung Lee Seok Kyu HanVibha Srivastava Eadi Sunil BabuSoon-Ku Hong Min-Jung KimJae-Ho Song Jung-Hoon SongHyojin Kim Dojin Kim 《Journal of Alloys and Compounds》2011,509(16):5137-5141
We report on the synthesis of high-quality ZnO nanorods by combining hydrothermal growth (HG) and chemical vapor deposition (CVD) processes. Vertically aligned and closely packed ZnO nanorods were grown by HG on a sputtered ZnO seed layer on a SiO2/Si (0 0 1) substrate. The top surface of the HG-prepared ZnO nanorods showed very flat surfaces compared with that of the sputtered ZnO seed layer. Therefore, the HG-prepared ZnO nanorods were used as a new alternative seed material for the CVD growth of the ZnO nanorods. Vertical ZnO nanorods were grown by CVD on both the new HG-prepared nanorod seed material and the sputtered ZnO seed layer. The CVD-prepared ZnO nanorods on new HG-prepared nanorod seed material showed better crystalline quality and superior optical properties than the CVD-prepared ZnO nanorods on sputtered seed layer. The former showed negligible deep-level emissions at room temperature photoluminescence measurements. The intensity ratio of near-band-edge emissions to deep-level emissions from the former was about 910, but that from the latter was about 151. This implies that the HG-prepared ZnO nanorods can be used as a promising new seed material for nanostructure synthesis. 相似文献
27.
In this study, transparent conductive oxide (TCO) electrodes with highly enhanced flexibility were developed on polymer substrates for application in flexible organic emitting diodes (OLEDs). TCOs, particularly indium tin oxide (ITO), have superior functional properties as electrodes compared to other materials but are inherently brittle, which significantly limits the bendability of the flexible devices. To improve the fracture strength of ITO on a polymer substrate under bending, we investigated the effect of expanding the film surface areas on the reduction of the stresses induced by an external bending force. Regularly spaced channels were imprinted at an elevated temperature onto polymer substrate surfaces using Teflon®. Then, both amorphous (a-ITO) and crystalline ITOs (c-ITO) were dc magnetron sputter deposited. As the channel patterns on the substrate surfaces were reflected into the growing film surfaces, the ITO surfaces became unidirectionally wavy, which increased the surface area by approximately 500%. The electrical and optical properties of the wavy ITOs were measured using a four-point probe and a UV–visible spectrophotometer, respectively, and the flexibility was evaluated with cyclic bending tests. For comparison, flexible OLEDs were also fabricated on both wavy ITO and conventional ITO. Our results revealed that the functional properties of ITOs with expanded surfaces are equivalent to those of conventional ITOs on the polymer substrates. However, their cyclic bending stability was significantly improved. After 10,000 cycles at a bending radius of 10 mm, the electrical resistivity change was less than half of the conventional ITO. The current density–voltage (J–V) characteristics of the flexible OLEDs on the wavy ITOs were also nearly equal to those on conventional ITOs. 相似文献
28.
Young Eun Hwang Seonghun Im Hyun Kim Jung-Hoon Sohn Byung-Kwan Cho Ju Hyun Cho Bong Hyun Sung Sun Chang Kim 《International journal of molecular sciences》2021,22(21)
Bacterial colonization and transmission via surfaces increase the risk of infection. In this study, we design and employ novel adhesive antimicrobial peptides to prevent bacterial contamination of surfaces. Repeats of 3,4-dihydroxy-L-phenylalanine (DOPA) were added to the C-terminus of NKC, a potent synthetic antimicrobial peptide, and the adhesiveness and antibacterial properties of the resulting peptides are evaluated. The peptide is successfully immobilized on polystyrene, titanium, and polydimethylsiloxane surfaces within 10 min in a one-step coating process with no prior surface functionalization. The antibacterial effectiveness of the NKC-DOPA5-coated polystyrene, titanium, and polydimethylsiloxane surfaces is confirmed by complete inhibition of the growth of Escherichia coli, Pseudomonas aeruginosa, and Staphylococcus aureus within 2 h. The stability of the peptide coated on the substrate surface is maintained for 84 days, as confirmed by its bactericidal activity. Additionally, the NKC-DOPA5-coated polystyrene, titanium, and polydimethylsiloxane surfaces show no cytotoxicity toward the human keratinocyte cell line HaCaT. The antimicrobial properties of the peptide-coated surfaces are confirmed in a subcutaneous implantation animal model. The adhesive antimicrobial peptide developed in this study exhibits potential as an antimicrobial surface-coating agent for efficiently killing a broad spectrum of bacteria on contact. 相似文献
29.
Tae-Sung Jung Young-Joon Choi Kang-Deog Suh Byung-Hoon Suh Jin-Ki Kim Young-Ho Lim Yong-Nam Koh Jong-Wook Park Ki-Jong Lee Jung-Hoon Park Kee-Tae Park Jhang-Rae Kim Jeong-Hyong Yi Hyung-Kyu Lim 《Solid-State Circuits, IEEE Journal of》1996,31(11):1575-1583
For a quantum step in further cost reduction, the multilevel cell concept has been combined with the NAND flash memory. Key requirements of mass storage, low cost, and high serial access throughput have been achieved by sacrificing fast random access performance. This paper describes a 128-Mb multilevel NAND flash memory storing 2 b per cell. Multilevel storage is achieved through tight cell threshold voltage distribution of 0.4 V and is made practical by significantly reducing program disturbance by using a local self-boosting scheme. An intelligent page buffer enables cell-by-cell and state-by-state program and inhibit operations. A read throughput of 14.0 MB/s and a program throughput of 0.5 MB/s are achieved. The device has been fabricated with 0.4-μm CMOS technology, resulting in a 117 mm2 die size and a 1.1 μm2 effective cell size 相似文献
30.
Humanoid robot dynamic walking is seriously affected by the initial home posture (walking ready posture). If the initial home
posture is not accurate, the robot may fall down during walking despite using robust walking control algorithm. Moreover,
the initial home posture of a real physical robot is slightly different at every setting because the zero position of the
joint is not exactly the same. Therefore, an accurate and consistent initial home posture is essential when we compare and
analyze walking control algorithms. In order to find a zero position, an incremental encoder with a limit switch or an absolute
encoder such as a potentiometer can generally be used. However, the initial calibration of this method for a multi-axis humanoid
robot that enables the desired initial sensor signal is difficult and time-consuming. Furthermore, it has the disadvantage
that additional limit switches or absolute encoders can interfere with the design objective of compactness. Therefore, this
paper describes a novel adjustment method of the home posture for a biped humanoid robot utilizing incremental encoders, an
inertial sensor and force torque sensors. Four kinds of controllers are proposed for the adjustment of the home posture and
adjusted offsets are measured when the outputs of the controllers have converged. Experimental results from KHR-2 show the
effectiveness of the proposed adjustment algorithm. 相似文献