• Nuclear Engineering and Technology
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• v.55 no.9
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• pp.3320-3325
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• 2023

The scaled water-cooled Reactor Cavity Cooling System (RCCS) experimental facility reproduces a passive safety feature to be implemented in Generation IV nuclear reactors. It keeps the reactor cavity and other internal structures in operational conditions by removing heat leakage from the reactor pressure vessel. The present work uses Flownex one-dimensional thermal-fluid code to model the facility and predict the experimental thermal-hydraulic behavior. Two representative steady-state cases defined by the bulk volumetric flow rate are simulated (Re = 2,409 and Re = 11,524). Results of the cavity outlet temperature, risers' temperature profile, and volumetric flow split in the cooling panel are also compared with the experimental data and RELAP system code simulations. The comparisons are in reasonable agreement with the previous studies, demonstrating the ability of Flownex to simulate the RCCS behavior. It is found that the low Re case of 2,409, temperature and flow split are evenly distributed across the risers. On the contrary, there's an asymmetry trend in both temperature and flow split distributions for the high Re case of 11,524.

• Proceedings of the KIPE Conference
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• 2020.08a
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• pp.387-388
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• 2020

본 논문은 패시브 셀 밸런싱과 액티브 셀 밸런싱의 에너지 손실 비교에 관한 연구내용이다. 패시브 셀 밸런싱은 저항을 이용하여 과충전된 셀의 에너지를 소모하는 방식이며 액티브 셀 밸런싱은 SSC(Single Switched Capacitor) 구조를 이용하여 높은 에너지 셀의 에너지를 낮은 에너지 상태의 셀로 전달하는 방식이다. 높은 셀과 낮은 셀의 SOC(State Of Charge)의 차이가 5% (0.085 V)일 때 ∆SOC = 3% (∆V = 0.051 V)로 줄이기 위해 패시브 셀 밸런싱과 액티브 셀 밸런싱을 하여 두 셀 밸런싱의 에너지 손실 차이를 시뮬레이션과 실험을 통하여 비교한다.

• Earthquakes and Structures
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• v.25 no.4
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• pp.297-305
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• 2023

The conventional method of structural seismic design was based on increasing structural capacity, which usually didn't reduce earthquake seismic effects. By changing the philosophy of structure design, technologies such as passive seismic control have been used in structures. So far, a large number of seismic isolation systems have been introduced to dissipate earthquake energy that is applied to a structure. These systems act against earthquakes rather than increasing the strength and capacity of the structure. In the present paper, a suspended column called a "pendulum column" is investigated, and a new idea has been considered to improve the performance of the pendulum column isolator by changing the gravity effect by adding a spring under the isolator system. The behavior of the studied isolator system has been researched. Then the isolator system was investigated under different earthquakes and compared with a common pendulum column isolator. The results show that changing the gravity effect has an effective role in the response of the system by reducing the system stiffness. Equations for the system showed that even in a special state, complete isolation is possible. Finally, the tested model verified the theory.

• The Plant Pathology Journal
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• v.37 no.1
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• pp.47-56
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• 2021

Plants protect against viruses through passive and active resistance mechanisms, and in most cases characterized thus far, natural recessive resistance to potyviruses has been mapped to mutations in the eukaryotic initiation factor eIF4E or eIF(iso)4E genes. Five eIF4E copies and three eIF(iso)4E copies were detected in Brassica rapa. The eIF4E and eIF(iso)4E genes could interact with turnip mosaic virus (TuMV) viral protein linked to the genome (VPg) to initiate virus translation. From the yeast two-hybrid system (Y2H) and bimolecular fluorescence complementation (BiFC) assays, the TuMV-CHN2/CHN3 VPgs could not interact with BraA.eIF4E.a/c or BraA.eIF(iso)4E.c, but they could interact with BraA.eIF(iso)4E.a in B. rapa. Further analysis indicated that the amino acid substitution L186F (nt T556C) in TuMV-UK1 VPg was important for the interaction networks between the TuMV VPg and eIF(iso)4E proteins. An interaction model of the BraA. eIF(iso)4E protein with TuMV VPg was constructed to infer the effect of the significant amino acids on the interaction of TuMV VPgs-eIF(iso)4Es, particularly whether the L186F in TuMV-UK1 VPg could change the structure of the TuMV-UK1 VPg protein, which may terminate the interaction of the BraA.eIF(iso)4E and TuMV VPg protein. This study provides new insights into the interactions between plant viruses and translation initiation factors to reveal the working of key amino acids.

• Journal of the Korean Chemical Society
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• v.22 no.6
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• pp.365-369
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• 1978

Ellipsometric and reflectance measurements were made on an iron surface in a cathodically reduced state and in an anodically passivated state. From the differences in the optical parameters (${\Delta},\;{\psi}$, and reflectance) between the reduced (film-free) and passivated (film-covered) states the thickness and optical constants of the surface film were determined. In the passive state at -400 mV vs. SCE in borate-boric acid buffer solution the anodic film had a thickness of about 11${\AA}$ and optical constants of ${\tilde{n}}$= 2.8 - 0.8 i. This value indicates a substantial electronic conductivity of the anodic film.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2008.05a
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• pp.869-872
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• 2008

This paper presents the VHDL implementation procedure of the passive RFID tag in Ultra High Frequency RFID system. The operation of the tag compatible with the EPCglobal Class1 Generation2(GEN2) protocol is verified by timing simulation after synthesis and implementation on prototyping board. Due to the reading range with relatively large distance, a passive tag needs digital processor which facilitates faster decoding, encoding and state transition for enhancement of the interrogation rate. Also with UART communication, verify a inventory Round in Gen2 Protocol. The verification results with the fastest data rate, 640kbps, and multi tags environment scenario show that the implemented tag spend 1.4ms transmitting the 96bits EPC to reader.

• Korean Journal of Veterinary Research
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• v.29 no.2
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• pp.75-81
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• 1989

The levels of the serum and colostral total protein and immunoglobulins of the Korean native cows immediately after parturition and colostrum-conferred passive immune status of the Korean native calves were studied, and the results obtained were summerized as follows: The mean total protein, total immunoglobulin, IgG, IgM, and IgA concentrations in sera of 10 Korean native cows immediately after parturition were $6.8{\pm}0.4g/dl$, $24.39{\pm}3.41mg/ml$, $19.49{\pm}2.70mg/ml$, $4.56{\pm}1.14mh/ml$, and $0.35{\pm}0.08mg/ml$ respectively. And the mean total protein, total immunoglobulin, IgG, IgM, and IgA concentrations in colostrum were $15.0{\pm}1.1g/dl$, $116.13{\pm}23.07mg/ml$, $101.51{\pm}22.59mg/ml$, $9.46{\pm}1.99mg/ml$, and $5.17{\pm}1.59mg/ml$ respectively. The mean concentrations of total protein and immunoglobulins in colostrum were 2.1 times to 14.8 times higher than those in serum. The mean concentrations of total protein, total immunoglobuln, IgG, IgM, and IgA in sera from 211 Korean native calves at 2 days old were $6.7{\pm}0.9g/dl$, $35.74{\pm}9.56mg/ml$, $29.06{\pm}8.07mg/ml$, $4.91{\pm}2.99mg/ml$, and $1,9{\pm}0.99mg/ml$ respectively. Although the calves had been suckled the dam's colostrum, each of calves was considerably various in levels of serum total protein and immunoglobulins and 16.1 percent of the calves were in a state of hypoglobulinemia.

• Corrosion Science and Technology
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• v.12 no.1
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• pp.40-49
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• 2013

Effects of magnesium and pH on corrosion of aluminum galvanically coupled to iron have studied by using potentio- dynamic and static tests for polarization curves, Mott-Schottky test for analysis of semiconductor property, and GD-AES and XPS for film analysis. Pitting potential was sensitive to magnesium as an alloying element but not to pH, while passive current was sensitive to pH but not to magnesium. It was explained with, instead of point defect model (PDM), surface charge model describing that the ingression of chloride depends on the state of surface charge and passive film at film/solution interface is affected by pH. In addition, galvanic current of aluminum electrically coupled to iron was not affected by magnesium in pH 8.4, 0.2M citrate solution but was increased by magnesium at the solution of pH 9.1. The galvanic current at pH 9.1 increased with time at the initial stage and after the exposure of about 200 minute, decreased and stabilized. The behavior of the galvanic current was related with the concentration of magnesium at the surface. It agreed with the depletion of magnesium at the oxide surface by using glow discharge atomic emission spectroscopy (GD-AES). In addition, pitting potential of pure aluminum was reduced in neutral pH solution where chloride ion maybe are competitively adsorbed on pure aluminum. It was confirmed by the exponential decrease of pitting potential with log of [$Cl^-$] around 0.025 M of [$Cl^-$] and linear decrease of the pitting potential. From the above results, unlike magnesium, alloying elements with higher electron negativity, lowering isoelectric point (ISE), are recommended to be added to improve pitting corrosion resistance of aluminum and its alloys in neutral solutions as well as their galvanic corrosion resistance in weakly basic solutions.

• IEMEK Journal of Embedded Systems and Applications
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• v.12 no.5
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• pp.267-275
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• 2017

Time of difference of arrival (TDOA) method using passive sonar sensor array has normally been used to estimate the location of a concealed moving target in underwater environment. Particle filter has been introduced for effective target estimation for non-Gaussian and nonlinear systems. In this paper, we propose a GPU-based acceleration of target position estimation using particle filter and propose efficient embedded system and software architecture. For the TDOA measurement from the passive sonar sensor, we use the generalized cross correlation phase transform (GCC-PHAT) method to obtain the correlation coefficient of the signal using FFT and we try to accelerate the calculation of GCC-PHAT based TDOA measurements using FFT with GPU CUDA. We also propose parallelization method of the target position estimation algorithm using the GPU CUDA to update the state of each particle for the target position estimation using the measured values. The target estimation algorithm was verified using Matlab and implemented using GPU CUDA. Then, we realized the proposed signal processing acceleration system using NVIDIA Jetson TX1 as the target board to analyze in terms of the execution time. The execution time of the algorithm is reduced by 55% to the CPU standalone-operation on the target board. Experiment results show that the proposed architecture is a feasible solution in terms of high-performance and area-efficient architecture.

• Proceedings of KOSOMES biannual meeting
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• 2006.11a
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• pp.265-269
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• 2006

Anti-Roll Tanks, also called Sloshing Tanks, is a rather common and sometimes an efficient method of limiting the roll angles. The important parameters, when considering using anti-roll tanks, are positioning, size, duct area, flow control device etc. Measurement by the PIV(Particle Image Velocimetry) was conducted to investigate the flow characteristics around control damper and inlet area of duct for three kind of inclined angle $(\alpha=0^*,\;10^*\;and\;20^*)$. Flow behaviors such as instantaneous and time-mean velocity vectors are investigated. Furthermore, to reveal boundaries between flowing and stagnant zones and to extract velocity profiles at any selected sections of the lower duct for passive anti-rolling tanks system.