Real-Time MPEG-2 Video Codec System Using Multiple Digital Signal Processors

A real-time MPEG-2 video codec system, called the KAIST image computing system (KICS), was developed using multiple multimedia video processors (MVP, TMS320C80). The number of computations and optimum implementation of the MPEG-2 algorithm were analyzed for real-time processing. An MVP simulator was used to perform the timing analysis for the real-time MPEG-2 encoding and decoding, and it verified the design of the KICS. Task partitioning and mapping of the MPEG-2 algorithm to multiple MVPs were performed based on load-balancing, minimum data I/O, and the properties of the MVP. The KICS uses five MVPs for MPEG-2 real-time encoding of a main profile at the main level whereas it uses three MVPs for real-time decoding.     

Video gameplay, personality and academic performance

The relationship between video gameplay, video game genre preference, personality, and GPA was investigated in an online correlational study with university students. In addition to administering self-report measures of GPA and personality, we asked three different questions regarding styles of video gameplay. The first asked the average time spent playing video games per week (habitual players), the second asked the total time spent playing favorite video games (selective players), and the third asked the number of different video games played in a year (diverse players). Students who were medium in selective player style (spent 11-50 h) had significantly higher GPAs than students low on selective player style (spent 0-10 h). Students high on habitual playing style (7 or more hours a week) showed significantly lower levels of Conscientiousness compared to students low on habitual playing style (0-1 h a week). Students who were high on the diverse style (i.e., 7 or more games played a year) showed significantly higher Openness scores than students low on the diverse style (0-3 games a year). Finally, several notable relations were found between video game genre preference, GPA, and personality. Results are discussed in terms of the positive implications of video gameplay on academic performance.     

Pull-out tests and slope stability analyses of nailing systems comprising single and multi rebars with grouted cement

The pull-out capacities for soil nailing systems comprising of one single 29 mm diameter (type A) and four 16 mm diameter (type B) rebars with grouted cement were examined. A field test and numerical analysis for the type A and type B systems were carried out to investigate the pull-out capacities and the slope stability reinforcement efficiency in soil and rock slopes. The results of the pull-out tests show the mobilized shear force and load transfer characteristics with respect to soil depth. The load-displacement relationship was examined for both type A and type B systems. Slope stability analyses were carried out to study the relationships between soil and nail reinforcement and bending stiffness as well as combined axial tension and shear forces. Factors of safety were calculated in relation to the number of nails and their outside diameters. Both soil and rock slopes were included in this evaluation.     

Structure-property relationships of nanocomposite-like polymer blends with ultrahigh viscosity ratios

We have investigated the structure-property relationships and the effects of a viscosity ratio on the rheological properties of nanocomposite-like polymer blends using oscillatory and steady shear rheometry and optical microscopy. These immiscible blends are consisted of ultrahigh viscous polybutadiene (PB1), high viscous polybutadien (PB2), and low viscous polydimethylsiloxane (PDMS). The PB1/PDMS blends with an ultrahigh viscosity ratio (λ=162,000) exhibit non-Newtonian fluids behavior for Ω≥0.1 while the PDMS/PB2 blends (λ=37) exhibit pseudo-Newtonian fluids behavior for Ω>0.6, where Ω is the weight fraction of PB1 or PB2 in the blends. The viscoelastic properties of the PB1/PDMS blends increase systematically with an increasing the weight fraction of PB1, and then exhibit plateau values above a certain maximum weight fraction (Ω_m) of PB1. In addition the viscoelastic properties of the PB1/PDMS blends are not affected by the change of blend morphology or phase inversion, where Ω_m is larger than the phase inversion weight fraction (Ω_p). In contrast the viscoelastic properties of the PB2/PDMS blends follow a positive-deviation mixing rule and are significantly affected by phase inversion.     

Particularities of condensation of atoms with increased kinetic energy

Novel universal method for measurement of the condensation coefficient α is developed. Using this method, noticeable difference between measured (α≈0.8) and expected (α≈1) values of the condensation coefficient for sputtered Cr atoms was revealed for the first time. The effect is assumed to be a result of considerable elevation of the surface temperature during atomic condensation induced by the energy delivered to the condensation surface by sputtered atoms and from the plasma.     

CuO formation control as a function of mixed ratio of Cu-free powders in the synthesis of YBCO superconductors on Cu substrates

YBa₂Cu₃O_x (Y123) superconducting films were fabricated on Cu substrates using a simple screen-printing method, from Cu-free powders (Y₂O₃ and BaCO₃). In the process, CuO, which causes superconducting properties of Y123 films to deteriorate, was formed on the film surface. By varying the atomic ratio of Y to Ba (Y:Ba = 1:1∼1:4), the ratio needed to prevent CuO formation was found for the film surface that had been heat-treated at 980^∘C for 17 s. The film, with the ratio of Y to Ba (Y:Ba = 1:1), is reheat-treated at 930^∘C for 9 min 30 s to form a superconducting Y123 phase. It was possible to prevent CuO formation by controlling the ratio of Cu-free powders in the mixture and to fabricate YBCO superconductors on Cu substrates using a two-step heat-treatment.     

Optoelectronic and microwave transmission characteristics of indium solder bumps for low-temperature flip-chip applications

This paper describes low-temperature flip-chip bonding for both optical interconnect and microwave applications. Vertical-cavity surface-emitting laser (VCSEL) arrays were flip-chip bonded onto a fused silica substrate to investigate the optoelectronic characteristics. To achieve low-temperature flip-chip bonding, indium solder bumps were used, which had a low melting temperature of 156.7/spl deg/C. The current-voltage (I-V) and light-current (L-I) characteristics of the flip-chip bonded VCSEL arrays were improved by Ag coating on the indium bump. The I-V and L-I curves indicate that optical and electrical performances of Ag-coated indium bumps are superior to those of uncoated indium solder bumps. The microwave characteristics of the solder bumps were investigated by using a flip-chip-bonded coplanar waveguide (CPW) structure and by measuring the scattering parameter with an on-wafer probe station for the frequency range up to 40 GHz. The indium solder bumps, either with or without the Ag coating, provided good microwave characteristics and retained the original characteristic of the CPW signal lines without degradation of the insertion and return losses by the solder bumps.     

Read/write mechanisms and data storage system using atomic force microscopy and MEMS technology

Information storage system that has a potentially ultrahigh storage density based on the principles of atomic force microscopy (AFM) has been developed. Micro-electro-mechanical systems (MEMS) technology plays a major role in integration and miniaturization of the standard AFM. Its potential application for ultrahigh storage density has been demonstrated by AFM with a piezoresponse mode to write and read information bits in ferroelectric Pb(Zr(x)Ti(1 - x))O3 films. With this technique, bits as small as 40 nm in diameter have been achieved, resulting in a data storage density of simply more than 200 Gb/in2. Retention loss phenomenon has also been observed and investigated by AFM in the piezoresponse mode. Finally, local piezoelectric measurements of PZT films by different processing technologies are discussed in detail.