• ETRI Journal
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• v.24 no.4
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• pp.280-289
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• 2002

In this work, we present a novel approach to the bit allocation problem that aims to minimize overall distortion subject to a bit rate constraint. The optimal solution can be found by the Lagrangian method with dynamic programming. However, the optimal bit allocation for block-based interframe coding is practically unattainable because of the interframe dependency of macroblocks caused by motion compensation. To reduce the computational burden while maintaining a result close to the optimum, i.e., near optimum, we propose an alternative method. First, we present a partitioned form of the bit allocation problem: a "frame-level problem" and "one-frame macroblock-level problems." We show that the solution to this new form is also the solution to the conventional bit allocation problem. Further, we propose a bit allocation algorithm using a "two-phase optimization technique" with an interframe dependency model and a rate-distortion model.

• Proceedings of the KSME Conference
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• 2001.06e
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• pp.463-468
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• 2001

This paper presents the methodology for thermal hydraulic analysis of Pressurized Water Reactor (PWR) steam generators. Topics include porous media approach, governing equations, physical models and correlations for solid-to-fluid interaction and heat transfer and numerical solution scheme. Some details about the ATHOS3 code currently used widely for thermal hydraulic analysis of PWR steam generators in the industry are presented. The ATHOS3 code is applied to the thermal hydraulic analysis of steam generator in the Korea YGN 3&4 nuclear power plant and the computed results are presented.

• Journal of International Society for Simulation Surgery
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• v.1 no.2
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• pp.57-61
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• 2014

We present a robust 3D facial reconstruction method using a single image generated by face-specific super resolution technique. Based on the several consecutive frames with low resolution, we generate a single high resolution image and a three dimensional facial model based on it. To do this, we apply PME method to compute patch similarities for SR after two-phase warping according to facial attributes. Based on the SRI, we extract facial features automatically and reconstruct 3D facial model with basis which selected adaptively according to facial statistical data less than a few seconds. Thereby, we can provide the facial image of various points of view which cannot be given by a single point of view of a camera.

• KSBB Journal
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• v.15 no.6
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• pp.605-608
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• 2000

Oligodeoxynucleotides (ODNs) were separated by high-performance membrane chromatography (HPMC), a combined system of chromatography and membrane. The separation mechanism involved anion-exchange, and the stationary phase was cation CIM (Convective Interaction Media) DEAE disk (16${\times}$3 mm). Two types of mobile phase were used, buffer A (20mM Tris-HCl, pH 7.4) and buffer B (buffer A + 1M NaCl). As the amount of NaCl dissolved in buffer linearly increased, the retention time shortened, which enabled a gradient elution mode. Based on the number of theoretical plates and resolution observed, the optimum mobile phase and operating condition (Buffer A/Buffer B=50/50 - 20/80 vol%, gradient time 2 min) were experimentally determined. In this experimental condition, ODNs were separated within 2 min at a mobile phase flow rate of 6 ml/min.

• Proceedings of the Computational Structural Engineering Institute Conference
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• 1994.10a
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• pp.201-208
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• 1994

To secure long-term structural safety of underground openings for radioactive waste disposal, the proper structural safety analyses are required. Especially, the structural analysis for underground openings should consider the effects of groundwater pressure. The objective of this study is to develop the structural analysis method for saturated rock masses. In this study, the interaction between groundwater distribution and structural behavior of rock masses are carried out to develop the structural analysis method of saturated rock masses. Then, a 3-Dimensional Multi-Phase Dynamic Analysis Program (MPDAP-3D) has been developed by modifying the existing MPDAP which is based on the concept of 2-dimensional two-phase media.

• Korean Journal of Soil Science and Fertilizer
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• v.44 no.2
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• pp.306-307
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• 2011

Two phases of experiment were conducted to produce compost using sewage sludge and sawdust as mixing materials to determine their chemical properties and the performance of selected test crops. The first phase was done to produce compost as potting media and the second phase was done to test the efficacy of the produced compost. With regard to some chemical properties of the compost, pH was moderately acidic (5.11 to 5.58) while the OM, N, P, and K contents of the compost were 23.8-35.9, 1.12-1.56, 254.9-555.7, and 40.4-62.6, respectively.

• The KIPS Transactions:PartC
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• v.14C no.4
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• pp.349-358
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• 2007

Ethernet Passive Optical Network(EPON), which is one of PON technologies for realizing FTTx(Fiber-To-The-Curb/Home/Office), can cost-effectively construct optical access networks. In addition, EPON can provide high transmission rate up to 10Gbps and it is compatible with existing customer devices equipped with Ethernet card. To effectively control frame transmission from ONUs to OLT EPON can use Multi-Point Control Protocol(MPCP) with additional control functions in addition to Media Access Control(MAC) protocol function. For EPON, many researches on intra- and inter-ONU scheduling algorithms have been performed. Among the inter-ONU scheduling algorithms, IPS(Interleaved Polling with Stop) based on polling scheme is efficient because OLT assigns available time portion to each ONU given the request information from all ONUs. Since the IPS needs an idle time period on uplink between two consecutive frame transmission periods, it wastes time without frame transmissions. In this paper, we propose a dynamic bandwidth allocation algorithm to increase the channel utilization on uplink and evaluate its performance using simulations. The simulation results show that the proposed Two-phase Cycle Danamic Bandwidth Allocation(TCDBA) algorithm improves the throughput about 15%, compared with the IPS and Fast Gate Dynamic Bandwidth Allocation(FGDBA). Also, the average transmission time of the proposed algorithm is lower than those of other schemes.

• Journal of Ginseng Research
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• v.20 no.1
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• pp.88-95
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• 1996

The effects of media, incubation time, temperature and pH on production of conidia and chlamydospore of Cylindrocarpon destructans (Zinssm.) Scholen causing root rot of Panax ginseng were studied. Microconidia of the pathogen were abundantly produced on V-8 juice agar as a solid substrate with 5.73(log conidia/mm2) and in V-8 broth as a liquid substrate with 6.65 (log conidia/ml) among media tested. No difference was observed on the length of microconidia produced from the media with a range of 9.50∼11.38 $\mu\textrm{m}$. However, tryptic soy agar produced the broadest microconidia (average 5.00 $\mu\textrm{m}$) among the media tested. All the media produced chlamydospores In a range of 1.06∼4.37 (log chlamydospores/mm2) without a significant difference in number, while V-8 juice agar produced the bigger one (18.39 $\mu\textrm{m}$ in diameter) as compared to the tested media. The fungus began to sporulate conidia after three days of incubation and reached maximum at the 8th day. It seemed to be in a stationary phase until 30 days of incubation but was decreased thereafter. Chlamydospore was produced at 4th day after incubation. Maximum production was observed at 8th day and the number seemed to be maintained during the observation period. Both conidia and chlamydospore of the pathogen were able to be spoluated at 10∼25$^{\circ}C$. However, optimum temperatures of conidia and chlamydospore formation were 15∼25$^{\circ}C$ and 10∼20$^{\circ}C$, respectively. C. destrmtans produced conida with an wide range of pH from 3.3 to 8.0 and chlamydospore from 2.8 to 8.0. Number of conidia was increased with an increase of pH up to 4.0. There was no significant difference in the number between 4.0 to 8.0. It seemed to have two optimum pH ranges, 3.3∼4.0 and 7.1∼8.0 for the chlamydospore formation.

• Biotechnology and Bioprocess Engineering:BBE
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• v.4 no.1
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• pp.21-25
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• 1999

Two low-salt complex media, bactopeptone and desalted yeast extract, were used for high density cultivation of the hyperthermophilic archaeon Sulfolobus solfataricus (DSM 1617). Bactopeptone, which has low mineral ion content among various complex media, was good for cell growth in batch cultures; the maximal cell density in bactopeptone was comparable to that in yeast extract. However, cell growth was rather poor when bactopeptone was added by the fed-batch procedure. Since several vitamins are deficient in abctopeptone, the effect of vitamins on cell growth was examined. Among the vitamins tested, pyridoxine was found to improve the growth rate of S. solfataricus. To reduce the growth inhibition caused by mineral ions, yeast extract was dialyzed against distilled water and then fed-batch cultures were carried out using a fed medium containing desalted yeast extract. Although the concentrations of mineral ions in yeast extract were significantly lowered by the dialysis whether low molecular weight solutes in yest extract are crucial for cell growth, we investigated the effect of trehalose, a most abundant compatible solute in yeast extract, on the growth pattern. Cell densities were increased and the length of the lag phase was markedly shortened by the presence of trehalose, indicating that trehalose plays an important role in the growth of S. solfataricus.

• Coupled systems mechanics
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• v.2 no.4
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• pp.375-387
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• 2013

Soils consist of an assemblage of particles with different sizes and shapes which form a skeleton whose voids are filled with water and air. Hence, soil behaviour must be analyzed by incorporating the effects of the transient flow of the pore-fluid through the voids, and therefore requires a two-phase continuum formulation for saturated porous media. The present paper presents briefly the Biot's basic theory of dynamics of saturated porous media with u-P formulation to determine the responses of pore fluid and soil skeleton during cyclic loading. Kelvin elements are attached to transmitting boundary. The Pastor-Zienkiewicz-Chan model has been used to describe the inelastic behavior of soils under isotropic cyclic loadings. Newmark-Beta method is employed to discretize the time domain. The response of fluid-saturated porous media which are subjected to time dependent loads has been simulated numerically to predict the liquefaction potential of a semi-infinite saturated sandy layer using finite-infinite elements. A settlement of 17.1 cm is observed at top surface. It is also noticed that liquefaction occurs at shallow depth. The mathematical advantage of the coupled finite element analysis is that the excess pore pressure and displacement can be evaluated simultaneously without using any empirical relationship.