An Analysis of Domestic Experimental Results for Soil-to-crops Transfer Factors of Radionuclides

In Jun,Young Ho Choi,Dong Kwon Keum,Hee Seok Kang,Han Soo Lee,Chang Woo Lee 대한방사선방어학회 2006 방사선방어학회지 Vol.31 No.4

Model for predicting the 137Cs contamination of an agricultural plant following a soil deposition)

In Jun,Dong-Kwon Keum,Hee-Seok Kang,Young-Ho Choi,Han-Soo Lee,Chang Woo Lee 한국방사성폐기물학회 2006 방사성폐기물학회지 Vol.4 No.4

[ ]의 토양침적으로 인한 농작물 오염 평가를 위한 동적격실모델이 제시되었다 토양침투(percolation), 쟁기질에 의한 토양혼합(soil mixing), 뿌리흡수(plant uptake), 용출(leaching to a deep soil), 토양고착(fixation to a clay mineral)이 모델에서 고려된 의 주요 이동경로이며 의 토양이동에 대한 토양특성(pH, 점토함량, 유기물함량, 이온교환성 K 농도)의 영향을 반영하기 위하여 Absalom 모델을 적용하였다. 모델의 검증을 위해 다른 토양특성을 가진 17종류의 논토양에서 2년 연속 벼를 재배하면서 수행한 모의침적실험으로부터 구한 벼에 대한 전이계수를 모델에 의한 예측치와 비교하였다. 측정된 벼의 전이계수는 pH와 점토함량 변화에는 뚜렷한 경향을 보여주지 않았으나, 유기물함량의 증가 또는 이온교환성 K 농도의 감소에 따라 다소 증가하는 경향을 보여주었다. 측정된 전이계수는 모델에 의한 예측치와 대체적으로 유사한 값을 가졌다. A dynamic compartment model is presented to predict the contamination level of agricultural plant by as a result of a soil deposition. The model considered the processes of a percolation, soil mixing by a plowing before transplanting, plant uptake, leaching to a deep soil, and fixation to a clay mineral. The effects of the soil properties (pH, clay mineral, organic matter content, and exchangeable K), which are spatially varied, on a plant uptake and the leaching rates of in a root zone soil were modeled by the Absalom model. To test the validity of the model, the aggregated transfer factors(TFa) for rice plants were compared with those observed from some simulated soil deposition experiments, which were carried out with respect to rice plants cultivated in seventeen paddy soils of different properties for two consecutive years. Observed TFa values of the rice plants did not show an evident trend for the pH and clay content of the soil properties, while they increased with an increasing organic matter content or a decreasing exchangeable K concentration. Predicted TFa values of the rice plants were found to be comparable with those observed.

High-Throughput Non-Binary LDPC Decoder Based on Aggressive Overlap Scheduling

Injun Choi,Ji-Hoon Kim IEEE 2017 IEEE TRANSACTIONS ON CIRCUITS AND SYSTEMS PART 1 R Vol.64 No.7

<P>Non-binary LDPC (NB-LDPC) codes offer better error correcting performance than their binary counterparts. However, to achieve excellent performance, decoding complexity and large memory are required, which makes it difficult to implement the high-throughput decoder. This paper presents a fully overlapped NB-LDPC decoder using three proposed techniques to improve throughput performance. First, an early bubble check is presented to reduce the initialization latency of the check node processing (CNP). Second, the CNP and variable node processing (VNP) are overlapped with the proposed backward memory scan method to hide the CNP latency within the VNP. Finally, we propose a redundant memory reuse technique to further decrease the latency of a single decoding iteration. We implemented the high-throughput decoder for (160, 80) regular (2, 4) NB-LDPC code over GF (64). The iteration latency was decreased by up to 57.5% with our three proposed methods. The proposed decoder achieved a throughput of 2.22 Gb/s at a 625-MHz frequency with 2.96-M gates in a 65-nm CMOS process. The proposed decoder showed outstanding area efficiency compared with the state-of-the-art decoders.</P>

Chemoattractant-Mediated Rap1 Activation Requires GPCR/G Proteins

Injun Cha,Sung H. Lee,전택중 한국분자세포생물학회 2010 Molecules and cells Vol.30 No.6

Rap1 is rapidly activated upon chemoattractant stimulation and plays an important role in cell adhesion and cytoskeletal reorganization during chemotaxis. Here, we demonstrate that G-protein coupled receptors and G-proteins are essential for chemoattractant-mediated Rap1 activation in Dictyostelium. The rapid Rap1 activation upon cAMP chemoattractant stimulation was absent in cells lacking chemoattractant cAMP receptors cAR1/cAR3 or a subunit of the heterotrimeric G-protein complex Gα2. Loss of guanylyl cyclases GCA/SGC or a cGMP-binding protein GbpC exhibited no effect on Rap1 activation kinetics. These results suggest that Rap1, a key regulator for the regulation of cytoskeletal reorganization during cell movement,is activated through the G-protein coupled receptors cAR1/cAR3 and Gα2 proteins in a way independent of the cGMP signaling pathway

A 12-bit 40 MS/s SAR ADC with Digital Foreground Self-calibration for Capacitor Mismatches

Injune Yeo,Byung-geun Lee 대한전자공학회 2020 Journal of semiconductor technology and science Vol.20 No.1

This study presents a 12-bit 40 MS/s successive approximation register (SAR) analog-to-digital converter (ADC) that utilizes a digital foreground self-calibration scheme for capacitor mismatches and a low-noise dynamic comparator. To reduce hardware complexity and AD power consumption, a split-capacitor, capacitive digital-to-analog converter (CDAC) is used to generate the comparator input voltage for binary search operations at the cost of increased capacitor matching requirements. Capacitor mismatches were calibrated with the digital foreground self-calibration technique, which was modified from our previous work to be adapted for the split-capacitor CDAC. In addition, a low-noise dynamic comparator that does not need an additional circuit and conversion cycles is also presented. A prototype ADC, which occupies an active die area of 0.098 mm2, is fabricated with a 65 nm standard CMOS process. By using the mismatch calibration scheme, the ADC achieves a spurious-free dynamic range and a signal-to-noise and distortion ratios of 79.0 dB and 67.4 dB, respectively, for a sampling rate of 40-MSample/s. The power consumption of the ADC is 1.96 mW when driven with a 1.2 V supply and the figure-of-merit is 25.58 fJ/conversion-step.

Dynamic Localization of the Actin-Bundling Pro-tein Cortexillin I during Cell Migration

Injun Cha,전택중 한국분자세포생물학회 2011 Molecules and cells Vol.32 No.3

Cortexillins are actin-bundling proteins that play a critical role in regulating cell morphology and actin cytoskeleton reorganization in Dictyostelium. Here, we investigated dynamic subcellular localization of cortexillin I in chemo-taxing Dictyostelium cells. Most of the cortexillin I was enriched on the lateral sides of moving cells. Upon che-moattractant stimulation, cortexillin I was rapidly re-leased from the cortex followed by a transient transloca-tion to the cell cortex with a peak at ~5 s and a subsequent decrease to basal levels, indicating that localization of cor-texillin I at the cortex in chemotaxing cells is controlled by two more signaling components, one for the initial delocalization from the cortex and another for the translocation to the cortex ~5 s after chemoattractant stimulation. Loss of cortexillins leads to reduced cell polarity and an in-creased number of lateral pseudopodia during chemotaxis, suggesting that cortexillins play an inhibitory role in producing pseudopodia along the lateral sides of the cell. Cells lacking cortexillins displayed extended chemoattrac-tant-mediated Arp2/3 complex translocation kinetics to the cortex. Our present study provides a new insight into the function of cortexillins during reorganization of the actin cytoskeleton and cell migration.

Analysis of non - uniform switching process in sub - micron MTJ cells

Injun Hwang,Sang Jin Park,Taewan Kim,Young Keun Kim 한국자기학회 2003 한국자기학회 학술연구발표회 논문개요집 Vol.13 No.2

Remanence analysis of sub - micron MTJ cells with CoFe / NiFe free layers

Injun Hwang,Wanjun Park,Sang Jin Park,Taewan Kim,Young Keun Kim 한국자기학회 2003 한국자기학회 학술연구발표회 논문개요집 Vol.13 No.2

Heterogeneity and Netting Efficiency under Central Clearing : A Stochastic Network Analysis

Injun Hwang,Baeho Kim 한국재무학회 2019 한국재무학회 학술대회 Vol.2019 No.05

This paper examines the effect of heterogeneity in clearing members’ exposure management practices on system-wide expected exposure under central clearing. Our network model specifies the dynamics of pre-netted interbank exposure as a joint stochastic process that shapes interdependent bank-to-bank exposure distributions beyond normality. Employing over-the-counter derivatives market data provided by the U.S. Office of the Comptroller of the Currency, our simulation results indicate that heterogeneity in bank-to-bank exposure dynamics and size is systemically desirable in general, while the entire system benefits more from central clearing in a more homogeneous environment. Furthermore, policymakers should incentivize individual clearing members to enhance resiliency and stability in counterparty exposure management to maximize netting efficiency under central clearing.

Enhanced electrochemical performance of peony flower-like carbon-coated γ- Ga2O3 nanosheets for lithium-ion battery anodes

Injun Jeon,Jin Hyun Hwang,Tae Gyun Kim,Linghong Yin,이형우,Jong Pil Kim,Hyung Soo Ahn,조채용 한양대학교 세라믹연구소 2021 Journal of Ceramic Processing Research Vol.22 No.2

Peony flower-like γ-Ga2O3 nanosheets (γ-Ga2O3 NSs) were synthesized and carbon layers were coated on their surfaces usinga simple hydrothermal process with subsequent carbonization. The γ-Ga2O3 NSs comprised ultrathin layers, which are tensof nanometers in thickness. The carbon-coated γ-Ga2O3 NS (γ-Ga2O3@C NS) electrode exhibited a specific capacity of 598mAh g−1 at 200 cycles, at a current density of 0.5 A g−1, higher than that of γ-Ga2O3 NSs (60 mAh g−1). Furthermore, a specificcapacity of 100 mAh g−1 at 5 A g−1 was achieved owing to the low charge transfer resistance through the carbon layers. Thisstudy suggests that two-dimensional γ-Ga2O3@C NSs with both large specific area and high charge carrier transport arepromising active materials for lithium-ion battery anodes with better electrochemical performance.