• 자원리싸이클링
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• 제25권4호
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• pp.60-67
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• 2016

본 연구에서는 P507을 포함하고 있는 추출수지를 사용하여 중희토류 원소인 Gd, Tb, Dy의 흡 탈착 반응 메커니즘을 고찰하고 분리를 위한 최적 크로마토그래피법의 반응조건을 도출하였다. 흡 탈착 반응 메커니즘은 흡착등온식인 Langmuir, Freundlich 흡착등온식과, 흡착속도모델인 유사 1차, 2차 반응속도식을 적용하여 고찰하였다. 중희토류 원소의 흡착반응은 단분자층으로 일어난다고 가정하여 흡착등온식을 적용하였고, 잘 일치하여 흡착반응이 단분자층으로 이루어짐을 추측할 수 있었다. 시간별 실험을 진행하여 유사 1차, 2차 반응속도식에 적용한 결과 유사 2차 반응속도식이 추출수지의 중희토류 흡착 메커니즘을 더 잘 표현하였고, 평형흡착량의 실험값은 이론값에 부합하였다. 크로마토그래피법을 이용하여 용리액 HCl 0.25 M 농도조건에서 ${\alpha}^{Tb}_{Gd}=1.24$, ${\alpha}^{Dy}_{Tb}=1.03$으로 분리계수 1이상의 높은 분리조건을 확인하였다. HCl 용리액을 사용하였을 때, 용리액의 농도가 높을수록 분리도는 감소하고 용출구간은 줄어드는 경향을 확인하였다.

• Journal of Information Processing Systems
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• 제9권2호
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• pp.333-348
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• 2013

Mobile authentication/identification has grown into a priority issue nowadays because of its existing outdated mechanisms, such as PINs or passwords. In this paper, we introduce gait recognition by using a mobile accelerometer as not only effective but also as an implicit identification model. Unlike previous works, the gait recognition only performs well with a particular mobile specification (e.g., a fixed sampling rate). Our work focuses on constructing a unique adaptive mechanism that could be independently deployed with the specification of mobile devices. To do this, the impact of the sampling rate on the preprocessing steps, such as noise elimination, data segmentation, and feature extraction, is examined in depth. Moreover, the degrees of agreement between the gait features that were extracted from two different mobiles, including both the Average Error Rate (AER) and Intra-class Correlation Coefficients (ICC), are assessed to evaluate the possibility of constructing a device-independent mechanism. We achieved the classification accuracy approximately $91.33{\pm}0.67%$ for both devices, which showed that it is feasible and reliable to construct adaptive cross-device gait recognition on a mobile phone.

• 한국전기전자재료학회논문지
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• 제17권10호
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• pp.1068-1078
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• 2004

In this paper we investigated the characteristics of surface degradation in silicone rubber due to corona exposure and recovery mechanism. It was shown that surface free energy was 22.42 mJ/$m^2$ on initial sample but surface free energy was approximately increased to 71.14 mJ/$m^2$ after 45 minutes. However, surface free energy on silicone rubber after corona discharge treatment was completely recovered within a short time due to diffusion of low molecular weight(LMW) silicone fluid. It was shown that corona discharge insured the increase of diffusible LMW chains, which could lead to recover the surface hydrophobicity. 200～370 g/mol distribution of LMW silicone fluid which was extracted by solvent-extraction with gel permeation chromatography (GPC) was contributed to recovery. The surface degradation characteristics on silicone rubbers and the recovery mechanism based on our results were discussed.

• Elastomers and Composites
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• 제33권1호
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• pp.37-43
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• 1998

The permeation of gas through polymer membrane at temperatures above its glass transition, generally occurs by a solution-diffusion mechanism. This mechanism is performed by the affinity difference between polymeric materials and gas molecules, and various technologies, such as copolymerization, impregnation and so on, have been researched to improve the affinity of polymeric material for the gases. In this study, permeability and selectivity for some gases were obtained from steady-state rates of gas permeation through silicone rubber membrane which is prepared by supercritical fluid extraction method. The permeability was measured by the volumetric method proposed by Barrer. Permeability was increased generally with temperature and permeation pressure. Silicone rubber membrane shows a higher permeability to $CO_2$ than to $O_2$, $N_2$. This results probably reflect the relatively high solubility of CO_2 in silicone rubber membrane, which is due to the affinity of $CO_2$ molecules. Since separation powers of $CO_2/N_2$, $CO_2/O_2$ were more than 200, and 100, respectively, it is able to separate $CO_2$ from the air, and the optimum temperature and pres-sure was 328.15 K, 60 cmHg respectively. In future, it is possible that the silicone rubber membrane can be used for separation or concentration of $CO_2$ through experiment for mixed gas separation.

• 약학회지
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• 제47권2호
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• pp.85-92
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• 2003

Seok-jeong (SJ) is a solution of various metal ions and numerous other organic substances produced through extraction and fermentation of herbs and soil using geo-microbes, and it has been shown to improve symptoms of senile dementia. In this study, we investigated the protective effects of SJ against neurotoxicity of cadmium in HT22 hippocampal neuron cell line. SJ significantly protected from the cadmium-induced decreased cell viability measured by MTT assay (p＜0.01). The protective effects of SJ against cadmium toxicity were confirmed through observing morphological changes using inverted microscope. Additionally, SJ significantly repressed the formation of lipid peroxidation induced by high concentration of cadmium, and likewise, significantly repressed the reduction of glutathione by cadmium in HT22 cells. Vitamin C at the concentration found in SJ did not show any protective effect against cadmium toxicity in HT22 cells, indicating that vitamin C may not have a major role in the protective mechanism of SJ. Taken together, these results suggest that SJ may be a valuable agent for the protection of cadmium toxicity on the neuronal cells, and that the mechanism of the action of SJ may be due to reduced lipid peroxidation and increased glutathione level.

• Journal of Microbiology
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• 제35권3호
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• pp.213-221
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• 1997

The secretion of the alkaliphilic Bacillus sp. S-1 extracellular pullulanase involves translocation across the cytoplasmic membrane of the Gram-positive bacterial cell envelope. Translocation of the intracellular pullulanase PUL-I, was traced to elucidate the mechanism and pathway of protein secretion from an alkaliphilic Bacillus sp. S-1. Pullulanase could be slowly bue quantitatively released into the medium during growth of the cells in medium contianing proteinase K. The released pullulanase lacked the N-terminal domain. The N-terminus is the sole membrane anchor in the pullulanase protein and was not affected by proteases, confirming that it is not exposed on the cell surface. Processing of a 180,000M$\_$r/ pullulanase to a 140,000M$\_$r/ polypeptide has been demonstrated in cell extracts using antibodies raised against 140,000M$\_$r/ extracellular form. Processing of the 180,000 M$\_$r/ protein occured during the preparation of extracts in an alkaline pH condition. A modified rapid extraction procedure suggested that the processing event also occured in vivo. Processing apparently increased the activity of pullulanase. The western blotting analysis with mouse anti-serum against 140-kDa extracellular pullulanase PUL-E showed that PUL-I is processed into PUL-X via intermediate form of PUL-E. Possible explanationa for the translocation are discussed.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제17권3호
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• pp.840-860
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• 2023

Aiming at the serious occlusion and slow tracking speed in pedestrian target tracking and recognition in complex scenes, a target tracking method based on improved YOLO v5 combined with Deep SORT is proposed. By merging the attention mechanism ECA-Net with the Neck part of the YOLO v5 network, using the CIoU loss function and the method of CIoU non-maximum value suppression, connecting the Deep SORT model using Shuffle Net V2 as the appearance feature extraction network to achieve lightweight and fast speed tracking and the purpose of improving tracking under occlusion. A large number of experiments show that the improved YOLO v5 increases the average precision by 1.3% compared with other algorithms. The improved tracking model, MOTA reaches 54.3% on the MOT17 pedestrian tracking data, and the tracking accuracy is 3.7% higher than the related algorithms and The model presented in this paper improves the FPS by nearly 5 on the fps indicator.

• 셀메드
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• 제13권6호
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• pp.7.1-7.6
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• 2023

Raphanus sativus L. has been reported to have anti-inflammatory and anti-tumor activity. However, the anti-inflammatory effect and mechanism of action of the Raphanus sativus L. seeds (RSS) with or without oil are still unknown. This study was undertaken to investigate the in-vitro anti-inflammatory effect with or without oil in the RSS on RAW 264.7 cells stimulated by lipopolysaccharide (LPS). Results showed the suppressed LPS-induced secretion of pro-inflammatory mediators such as nitric oxide (NO), inflammatory cytokine (IL-6, TNF-α). Additionally, a decrease in protein expression of iNOS was observed, but nuclear translocation of NF-κB p65 was not inhibited. To elucidate the underlying mechanism of the anti-inflammatory effect of RSS, the involvement of mitogen-activated protein kinase (MAPK) signaling pathways was examined. We also found that RSS blocked LPS-induced phosphorylation of c-Jun N-terminal kinase/stress-activated protein kinase (JNK) signaling but did not affect the phosphorylation of p38 MAPK and extracellular signal-regulated kinase (ERK) 1/2. These results suggest that RSS may have potential as an anti-inflammatory agent through the inhibition of LPS-induced inflammatory cytokine production via regulation of the JNK pathway.

• 한국인터넷방송통신학회논문지
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• 제23권6호
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• pp.89-95
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• 2023

인간 행동 인식 (Human action recognition, HAR) 기술은 스포츠 분석, 인간과 로봇 간의 상호작용, 대형 사이니지 콘텐츠 등의 애플리케이션에 활용되는 핵심 기술 중 하나이다. 본 논문에서는 몰입형 대형 사이니지 콘텐츠를 위한 STAGCN (Spatial temporal attention graph convolutional network) 기반 인간 행동 인식 시스템을 제안한다. STAGCN은 attention mechanism을 통해 스켈레톤 시퀀스의 시공간적 특징에 서로 다른 가중치를 부과하여, 동작 인식에 중요한 관절 및 시점을 고려할 수 있다. NTU RGB+D 데이터셋을 사용한 실험 결과, 제안된 시스템은 기존 딥러닝 모델들에 비해 높은 분류 정확도를 달성한 것을 확인했다.

• 대한기계학회논문집A
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• 제36권6호
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• pp.645-651
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• 2012

본 논문은 부표로봇에 부착된 카메라 영상의 흔들림을 보정하기 위하여 새로운 방법을 제안한다. 본 연구에서는 부표로봇의 각도측정에 사용하는 자이로 센서의 누적오차 및 노이즈 등의 문제를 해결하기 위해 새로운 기구 메커니즘을 영상처리와 결합한 방법을 제안한다. 이 알고리즘은 특징 점을 추출하기 위한 타깃을 제안한 기구에 부착하여 타깃의 모형 특징을 기반으로 영상을 보정하는 방법이다.