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In present study, a two dimensional unsteady Navier-Stokes solver has been developed using the Diagonalized ADI (DADI) method and implicit dual time stepping method. The jacobian matrices in steady state Navier-Stokes equations are introduced from inviscid flux terms. The implicit treatment of artificial dissipation terms results in a block penta-diagonal matrix system and it becomes a scalar penta-diagonal matrix by diagonalization. In steady state equations about fictitious time, a new residual including a real time derivative term is introduced. From a converged solution about fictitious time, a real time unsteady solution can be obtained, which is called `implicit dual time stepping method`. For code validation, an oscillating flat plate, a regular Karman vortices past a circular cylinder and shock buffeting around a bicircular airfoil problems are numerically solved. And they are compared with a theoretical solution, experiments and other researcher`s computations.

To verify the changes of mesopic and photopic contrast sensitivity function of sound eye whose visual acuity was kept the same after occlusion therapy in the amblyopic children. Fourteen sound eyes of amblyopic children (mean; 7.67 years; S.D., 1.50 years) who kept their visual acuity the same after the occlusion therapy were tested. The children had 6 hours of part-time patch therapy for 3 months prior to this examination. Among 14 amblyopic children, 8 were anisometric and 6 were strabismic amblyopes. Using the visual capacity analyzer which measures the minimal contrast level at from low to high spatial frequencies, the contrast sensitivity of sound eye was measured, under both photopic and mesopic condition, before and after 3 months of occlusion therapy. Comparing the contrast sensitivity of sound eye after the occlusion therapy to that before the occlusion, there was no statistical difference in photopic condition. When it comes to mesopic condition, the contrast sensitivity decreased at the intermediate spatial frequency level (3-13 c.p.d, p=0.028) after the occlusion therapy. The occlusion caused statistically significant decrease in mesopic contrast sensitivity, when the visual acuity was not changed after the occlusion therapy. It may indicate that mesopic contrast sensitivity can be considered as a useful tool for early detection of hidden occlusion amblyopia.

In this paper, a small supersonic wind tunnel was designed and built to study the flow characteristics of a supersonic impulse turbine cascade by experiment. The flow was visualized by means of a single pass Schlieren system. The supersonic cascade with 3-dimensional supersonic nozzle was tested over a wide range of pressure ratio. Highly complicated flow patterns including shocks. nozzle-cascade interaction and shock boundary layer interactions were observed.

The turbine efficiency is an important factor in power plant, and accurate evaluation of steam turbine performance is the key issue in turbo machinery industry. The difficulty of evaluating the steam turbine performance due to its high steam temperature and pressure environment makes the most steam turbine tests to be replaced by air similarity test. This paper presents how to decide the similarity conditions of the steam turbine test and describes its limitations and assumptions. The test facility was developed and arranged to conduct an air similarity turbine performance test with various inlet pressure, temperature and mass flow rate. The eddy-current type dynamometer measures the turbine-generated shaft power and controls the rotating speed. Pressure ratio of turbine can be controled by back pressure control valve. To verify its test results, uncertainty analysis was performed and relative uncertainty of turbine efficiency was obtained.

The solid solutions of the Sr 1-xBaxFeO3-y system (x = 0.0, 0.1, 0.2 and 0.3) having a perovskite structure were prepared in air at 1423 K and then heat-treated in air (A), O 2(O) and N2(N) to examine possibility of controlling the nonstoichiometry and applicability as an additive for electrical conducting inorganic adhesives (ECIA). In the samples heated in N2 stream, there existed almost no Fe 4+ ions, and at constant te mperature their electrical conductivities were considerably lower than th ose of the samples heat-treated in air or O 2. Sr0.8Ba0.2Fe 3+ 0.49Fe 4+ 0.51O2.76 (SB2-A) whose Fe 3+ /Fe 4+ ratio was nearly 1 (0.96) and whose conductivity values (1.04 ohm −1 cm −1 at 283 K and 1.88 ohm −1 cm −1 at 673 K) were higher than any other samples, was found to be Fe 4+ τO4-y system (x = 0.0, 0.1, 0.2 and 0.3) prepared in O 2 stream, Sr0.9Ba0.1La1.00 Fe 3+ 0.55Fe 4+ 0.45O4.225 and Sr0.8Ba0.2- La1.00Fe 3+ 0.54Fe 4+ 0.46O4.230 had considerably high conduc- tivity values (ohm −1 cm −1 ) of -2.4 (at 283 K) ~ -0.7(at 573 K) and -2.8 (at 283 K) ~ -1.1 (at 573 K). Adding them into inorganic adhesive (AB-11, made from the reaction of the mixtures of SiC, ZnO2 and NaOH) with several composition, various ECIAs for high temperature were prepared and, among them, ECIA-3 12 containing Sr0.8Ba0.2La1.00Fe 3+ 0.54 Fe 4+ 0.46O4.230 (70 wt%) exhibited the highest conductivity values of -3.24 ohm −1 cm −1 at 290K and -1.99 ohm −1 cm −1 at 773 K. In that study, however, the adhesive properties of ECIA-2 (containing Sr0.9Ba0.1La1.00Fe 3+ 0.55Fe 4+ 0.45O4.225(70 wt%)) and ECIA-3 (containing Sr0.8Ba0.2La1.00Fe 3+ 0.54 Fe 4+ 0.46O4.230 (70 wt%)) were not satisfactory because of their lower conductivity values than those of metals like Cu and Fe, and of their sensitiveness to curing conditions. Considering such previous works, this study was aimed at performing synthesis and heat-treatments of the Sr 1-x- BaxFeO3-y system (x = 0.0, 0.1, 0.2 and 0.3) under various conditions (in air, in O 2 (1 atm) and in N2 (1 atm)), at checking whether it is possible to control the nonstoichi- ometry of the Sr1-xBaxFeO3-y system and eventually at investigating their applicability as additives for ECIAs for electrolytic oxygen evolution electrode 3,4 and solid oxide fuel cell. 5 The changes of oxygen contents with temperature, of mixed valency ratios of Fe 3+ and Fe 4+ and of conduc- tivities were measured. Finally mixing each sample (20 wt%) with BG-11 inorganic adhesive, 14 ECIAs were prepared and their properties were examined.

The aim of this paper is to describe the results of the study on the extreme-ultra-violet (EUV) solar telescope, which is designed for a possible satellite mission. Since the EUV band can not be observed on the ground, the observation in EUV should be performed in space using a satellite or a rocket. Design of the Extreme-Ultra-Violet solar Telescope (EUVT) in this study is based on ``Designing a small-sized engineering model of solar EUV telescope for a Korean satellite" (Han et al. 2001). Our EUVT design is satisfied with the requirements for a satellite in size and input voltage. The major goal of the study is to confirm if we can detect the specific wavelength (58.4nm to 62.9nm) with the EUVT. We describe re-designing of the EUVT to decrease a shelter ratio. Also we describe the technics in the optic system and the detector, which were used to manufacture the EUVT. We explain the detective program, which is to calculate the amount of the solar radiation, and the image data processing system.

The KSR-3 magnetometers consist of the fluxgate magnetometer (MAG/AIM) for acquiring the rocket flight attitude information, and the search-coil magnetometer (MAG/SIM) for the observation of the Earth's magnetic fluctuations. The position (latitude, longitude, and height) and flight condition (the transformation angle) of the rocket is measured after the data based on these two magnetometers are compared with IGRF. The gap in the vector of magnetic field between the position of the launching point and an impact point is taken into account in data reduction. Angular variation of pitch, yaw, and roll can be researched when the data is applied to the coordinate system of the rocket.

Bioanalysis and Biotransformation Research Center, Korea Institute of Science and Technology, Seoul 136-791, KoreaReceived October 23, 2002The kinetic and chemical mechanisms of AChE-catalyzed hydrolysis of short-chain thiocholine esters arerelatively well documented. Up to propanoylthiocholine (PrTCh) the chemical mechanism is general acid-basecatalysis by the active site catalytic triad. The chemical mechanism for the enzyme-catalyzed butyrylthio-choline(BuTCh) hydrolysis shifts to a parallel mechanism in which general base catalysis by E199 of directwater attack to the carbonyl carbon of the substrate. [Selwood, T., et al. J. Am. Chem. Soc. 1993, 115, 10477-10482] The long chain thiocholine esters such as hexanoylthiocholine (HexTCh), heptanoylthiocholine(HepTCh), and octanoylthiocholine (OcTCh) are hydrolyzed by electric eel acetylcholinesterase (AChE). Thekinetic parameters are determined to show that these compounds have a lower Michaelis constant than BuTChand the pH-rate profile showed that the mechanism is similar to that of BuTCh hydrolysis. The solvent isotopeeffect and proton inventory of AChE-catalyzed hydrolysis of HexTCh showed that one proton transfer isinvolved in the transition state of the acylation stage. The relationship between the dipole moment and theMichaelis constant of the long chain thiocholine esters showed that the dipole moment is the most importantfactor for the binding of a substrate to the enzyme active site.Key Words : Acetylcholinesterase, Hydrolysis, Thiocholine esters, Kinetic studies, Chemical mechanismIntroductionAcetylcholinesterase (AChE, EC 3.1.1.7) is a serinehydrolase that catalyzes the hydrolysis of the neurotrans-mitter, acetylcholine (ACh) to acetate and choline atneuromuscular synapses.

There are many methods to enhance the fault tolerance of the CORBA based real time systems by viewpoints. Among them, this paper provides a method to enable seamless services where the systems based on the CORBA have object`s faults originated processing real time information. Namely, this paper observes a method to deal efficiently with object`s faults happening in 3 tier architecture environments. It is possible to replicate objects as a way to enhance the fault tolerance considering object`s faults. Along with it, this paper shows a method to enhance the fault tolerance ultimately and then keep the service continuity by prividing a way to allow to continue to run the systems until the FT-CORBA based one`s faults are recovered.

This paper describes the re-design and the calibration results of the MAG digital circuit onboard the KSR-3. We enhanced the sampling rate of magnetometer data. Also, we reduced noise and increased authoritativeness of data. We could confirm that AIM resolution was decreased less than 1nT of analog calibration by a digital calibration of magnetometer. Therefore, we used numerical-program to correct this problem. As a result, we could calculate correction and error of data. These corrections will be applied to magnetometer data after the launch of KSR-3.

As the type of property data of military terrain analysis map is using FACC of DIGEST, there is a limitation in utilizing a domestic thematic map which is in use of other type of property data. However, even though the attempts to utilize the domestic thematic map are made at military sites, the study has not been conducted enough. Therefore, we defined it by matching the property data necessary for the military terrain analysis cartography and property of the domestic thematic map, and analyzed in accordance with the method to analyze the cross-country movement roads specified in FM 5-33. But, there was no data for the diameter of trees in the vegetation map among a terrain analysis map, whereas there being data for the sort of trees. As the diameter of trees can be broken through to the extent of certain diameters by tracked vehicles, they are the factors necessary in analyzing. In this study, the research was conducted focusing on calculating the diameters for some trees described in a stand yield table by using the age-class for trees in a forest floor map with a scale of 1:5000 and calculating the diameters of trees by using the diameter-class for the diameters of other trees.

A two-stage anaerobic fluidized-bed membrane bioreactor (SAF-MBR) system was applied for the treatment of primary-settled domestic wastewater that was further pre-treated by either 10 μm filtration or 1 mm screening. While the different pre-treatment options resulted in different influent qualities, the effluent qualities were quite similar. In both cases at a total hydraulic retention time of 2.3 h and 25 °C, chemical oxygen demand and biochemical oxygen demand (BOD5) removals were 84–91% and 92–94%, with effluent concentrations lower than 25 and 7 mg/L, respectively. With a membrane flux of 6–12 L/m2/h, trans-membrane pressure remained below 0.2 bar during 310 d of continuous operation without need for membrane chemical cleaning or backwashing. Biosolids production was estimated to be 0.028–0.049 g volatile suspended solids/g BOD5, which is far less than that with comparable aerobic processes. Electrical energy production from combined heat and power utilization of the total methane produced (gaseous and dissolved) was estimated to be more than sufficient for total system operation.

Ultrasound volume rendering is an efficient method for visualizing the shape of fetuses in obstetrics and gynecology. However, in order to obtain high-quality ultrasound volume rendering, noise removal and coordinates conversion are essential prerequisites. Ultrasound data needs to undergo a noise filtering process; otherwise, artifacts and speckle noise cause quality degradation in the final images. Several two-dimensional (2D) noise filtering methods have been used to reduce this noise. However, these 2D filtering methods ignore relevant information in-between adjacent 2D-scanned images. Although three-dimensional (3D) noise filtering methods are used, they require more processing time than 2D-based methods. In addition, the sampling position in the ultrasonic volume rendering process has to be transformed between conical ultrasound coordinates and Cartesian coordinates. We propose a 3D-mipmap-based noise reduction method that uses graphics hardware, as a typical 3D mipmap requires less time to be generated and less storage capacity. In our method, we compare the density values of the corresponding points on consecutive mipmap levels and find the noise area using the difference in the density values. We also provide a noise detector for adaptively selecting the mipmap level using the difference of two mipmap levels. Our method can visualize 3D ultrasound data in real time with 3D noise filtering.

Faculty of Life Science Engineering, Youngdong University, Chungbuk 370-701, KoreaReceived November 5, 2002Key Words : Cholinesterase, Inhibition, Boronic acid, BenzothiophenonesSince cholinesterases (ChE) such as acetylcholinesterase(AChE) and butyrylcholinesterase (BuChE) play criticalroles for the neurotransmission, the detailed chemicalmechanism of the ChE-catalyzed reactions are welldocumented.

Time accurate numerical simulations are performed for the flow field around a vonKarman ogive with fineness ratio of 3.5 under the plasma actuation near the nose tip in a freestream of M=0.1 and ReD=220,000 to evaluate the effects of the actuation. The moving wall boundary condition is employed to model the plasma actuation. The velocity of the moving wall is correlated by the momentum produced by the plasma actuator on a flat plate using PIV measurements. The flow separation is promoted so that the pressure increases and the vortex is lifted up on the actuation side. Steady side forces with increasing magnitude are observed with increasing moving wall velocity. Increasing the moving wall velocity increases the rate of spatial evolution of the vortex asymmetry in the axial direction. The behavior of the side force observed in the simulation in terms of direction and magnitude in response to the actuation agrees with the observations in the wind tunnel test conducted by the authors under the same model geometry and freestream condition. Nomenclature Cp = pressure coefficient Cz = force coefficient in the yaw direction (positive toward the port from the starboard) D = Base diameter of the ogive model M = Mach number ReD = Reynold’s number based on D U∞ = Magnitude of the freestream velocity Uw = Magnitude of the moving wall velocity u = Velocity component in the horizontal direction v = Velocity component in the vertical direction x = Longitudinal axis of the ogive model (positive toward the base from the nose)  = Angle of attack

We propose adaptive power control of obstacle avoidance system for visually impaired person. It utilizes multiple ultrasonic sensors to avoid obstacles lying in the path. We evaluate complex structure in front of the user with predefined patterns and determine avoidance direction by analysing those patterns. It controls the number of active ultrasonic sensors by evaluating motion context using built-in accelerometer sensor. Our system safely guides visually impaired person as well as adaptively control power consumption of mobile devices.

Recent researches of terrain visualization require fast and accurate rendering of massive terrain datasets. GPU-based ray-casting algorithm is one of the terrain visualization methods which support artifact-free scenes with fast rendering speed. However, as the resolution of dataset and display device has been grown larger, acceleration techniques are required for rendering the terrain in real-time. In this paper, we propose an acceleration technique using vertex propagation, which accelerates the ray-casting with quadtree-based empty space skipping. We perform the vertex propagation by subdividing a bounding box of the terrain. These boxes produce an optimal boundary of terrain which depends on viewing conditions. By marching the ray/height-field intersection only inside the bounding boxes, we can efficiently skip empty spaces. Experimental results show our method efficiently reduced the number of repetitions in previous quadtree traversal techniques and decrease the rendering speed about 30–50%.

Purpose: The purpose of this study was to determine the significant factors for risk estimate of aspiration and to evaluate the efficiency of the dysphagia assessment tool. Methods: A consecutive series of 210 stroke patients with aspiration symptoms such as cough and dysphagia who had soft or regular diet without tube feeding were examined. The dysphagia assessment tool for aspiration was compared with videofluoroscopy using Classification and Regression Tree (CART) analysis. Results: In CART analysis, of 34 factors, the significant factors for estimating risk of aspiration were cough during swallowing, oral stasis, facial symmetry, salivary drooling, and cough after swallowing. The risk estimate error of the revised dysphagia assessment tool was 25.2%, equal to that of videofluoroscopy. Conclusion: The results indicate that the dysphagia assessment tool developed and examined in this study was potentially useful in the clinical field and the primary risk estimating factor was cough during swallowing. Oral stasis, facial symmetry, salivary drooling, cough after swallowing were other significant factors, and based on these results, the dysphagia assessment tool for aspiration was revised and complemented.

Unique starlike CdS particles were prepared from the lyotropic triblock copolymer solution system. The starlike CdS consists of a spherical core and dozens of the attached conical nanolobes. From the comparative studies with the spherical and rod-shaped CdS nanoparticles, the unique photophysical property is presented for the starlike CdS particle. The experimental results suggest that the photogenerated charge carriers at the tip-edge region of the conical nanolobe in the starlike CdS system diffuse into the thicker inner part including the core region, which is possibly due to the decreasing excited state potential gradient from the tip edge to the thicker inner part. This type of charge carrier diffusion dynamics from the surrounding to the thicker inner part in this anisotropic morphology of the starlike CdS semiconductor closely resembles the energy transfer dynamics in the organic dendrimers.

A prototype centrifugal compressor was designed for applying to a small turboshaft engine, and tested [1, 2]. As a component of the small turboshaft engine, the impeller has rather high value of inlet hub-tip ratio, 0.64. Also, for the compactness of engine, the compressor was designed with restricted dimensions in diameter. The absolute Mach number at the exit of the impeller reaches to sonic velocity to attain design pressure ratio, 4.89. Thus, the effective pressure recovery is the one of the main concern within the given dimension. The compressor in this study employs two-row tandem diffusers aiming high efficiencies. 3D viscous calculations are carried out to understand the flow structures in detail. Numerically predicted flow fields for off design conditions as well as for on design condition are discussed. Effects on the relative circumferential positions of the diffuser rows are studied for the cases of isolated diffusers to quantify the preferable configurations. According to the flow fields, it would be preferable to have some twist angles at leading edges for both rows of the diffusers to adapt incoming flows. On choking condition, recirculating flows are observed at the shroud region of the 2nd row diffuser.Copyright © 2003 by ASME

A series of samples in the Sr/sub x/Dy/sub 1-x/FeO/sub 3-y/ system (x = 0.00, 0.25, 0.50, 0.75, and 1.00) have been produced by heating the reactants to 1200/sup 0/C in air under atmospheric pressure. Mohr salt analysis shows that DyFeO/sub 3/ is a stoichiometric compound and that Fe/sup 4 +/ ions and oxygen deficiency compensate for the cation charge deficiency which is caused by substitution of Sr/sup 2 +/ at Dy/sup 3/..mu.. sites. X-ray powder diffraction assigns the compositions x = 0.00 and 0.25 to the orthorhombic system and the composition x = 0.50, 0.75, and 1.00 to the cubic system. The electrical conductivity sharply increases and the activation energy decreases with the presence of mixed iron valency. The Moessbauer spectra of the samples with x = 0.25 and 0.50 are composed of two sets of lines and a single broad peak for x = 0.75.