• IMMUNE NETWORK
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• 제20권5호
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• pp.41.1-41.11
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• 2020

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV2) is a positive-sense single-stranded RNA (+ssRNA) that causes coronavirus disease 2019 (COVID-19). The viral genome encodes twelve genes for viral replication and infection. The third open reading frame is the spike (S) gene that encodes for the spike glycoprotein interacting with specific cell surface receptor - angiotensin converting enzyme 2 (ACE2) - on the host cell membrane. Most recent studies identified a single point mutation in S gene. A single point mutation in S gene leading to an amino acid substitution at codon 614 from an aspartic acid 614 into glycine (D614G) resulted in greater infectivity compared to the wild type SARS-CoV2. We were interested in investigating the mutation region of S gene of SARS-CoV2 from Korean COVID-19 patients. New mutation sites were found in the critical receptor binding domain (RBD) of S gene, which is adjacent to the aforementioned D614G mutation residue. This specific sequence data demonstrated the active progression of SARS-CoV2 by mutations in the RBD of S gene. The sequence information of new mutations is critical to the development of recombinant SARS-CoV2 spike antigens, which may be required to improve and advance the strategy against a wide range of possible SARS-CoV2 mutations.

• 한국컴퓨터정보학회논문지
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• 제22권5호
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• pp.21-28
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• 2017

As technology related to digital imaging equipment is developed and generalized, digital imaging system is used for various purposes in fields of society. The object tracking technology from digital image data in real time is one of the core technologies required in various fields such as security system and robot system. Among the existing object tracking technologies, cam shift technology is a technique of tracking an object using color information of an object. Recently, digital image data using infrared camera functions are widely used due to various demands of digital image equipment. However, the existing cam shift method can not track objects in image data without color information. Our proposed tracking algorithm tracks the object by analyzing the color if valid color information exists in the digital image data, otherwise it generates the lightness feature information and tracks the object through it. The brightness feature information is generated from the ratio information of the width and the height of the area divided by the brightness. Experimental results shows that our tracking algorithm can track objects in real time not only in general image data including color information but also in image data captured by an infrared camera.

• 대한의생명과학회지
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• 제18권2호
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• pp.104-111
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• 2012

Matrix metalloproteinases (MMPs) are zinc-dependent endopeptidases which degrade extracellular matrix (ECM) during embryogenesis, wound healing, and tissue remodeling. Dysregulation of MMP activity is also associated with various pathological inflammatory conditions. In this study, we examined the expression pattern of MMPs during PMA-induced differentiation of THP-1 monocytic cells into macrophages. We found that MMP1, MMP8, MMP3, MMP10, MMP12, MMP19, MMP9, and MMP7 were upregulated during differentiation whereas MMP2 remained unchanged. Expression of MMPs increased in a time-dependent manner; MMP1, MMP8, MMP3, MMP10, and MMP12 increased beginning at 60 hr post PMA treatment whereas MMP19, MMP9, and MMP7 increased beginning at 24 hr post PMA treatment. To identify signal transduction pathways involved in PMA-induced upregulation of MMPs, we treated PMA-differentiated THP-1 cells with specific inhibitors for PKC, MEK1, NF-${\kappa}B$, PI3K, p38 MAPK and PLC. We found that inhibition of the MEK1 pathway blocked PMA-induced upregulation of all MMPs to varying degrees except for MMP-2. In addition, expression of select MMPs was inhibited by PI3K, p38 MAPK and PLC inhibitors. In conclusion, we show that of the MMPs examined, most MMPs were up-regulated during differentiation of monocyte into macrophage via the MEK1 pathway. These results provide basic information for studying MMPs expression during macrophage differentiation.

• Journal of Ginseng Research
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• 제32권2호
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• pp.107-113
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• 2008

In this study, we have investigated the effect of panaxatriol (PT) on phosphoinositides (PIS) breakdown and $Ca^{2+}$-elevation in thrombin-induced platelet aggregation. Thrombin (5U/ml), a potent platelet agonist which activates phospholipase $C_{\beta}$ via protease activated receptor (PAR), hydrolyzed PIS in platelet membrane. The phosphatidylinositol 4, 5-bisphosphate $(PIP_2)$ was hydrolyzed after 10 sec of the thrombin-stimulation, and both the phosphatidylinositol 4-monophosphate (PIP) and phosphatidylinositol (PI) were brokendown after 30 sec of the thrombin-stimulation. However, PT inhibited the thrombin-stimulated hydrolysis of $PIP_2$, PIP, and PI. On the other hand, thrombin increased the level of phosphatidic acid (PA) which is phosphorylated from diacylglycerol (DG) generated by PIS-hydrolysis. However, Pr inhibited the thrombin-increased PA level non-significantly. Thrombin increased cytosolic free $Ca^{2+}([Ca^{2+}])_i$) up to 72% as compared with control $(30.8{\pm}0.9 nM)$ in intact platelet. However, PT (100 ${\mu}g/ml$) inhibited the thrombin-elevated $[Ca^{2+}]_i$ to 100%. These results suggest that PT may have a beneficial effect on platelet aggregation-mediated thrombotic disease by inhibiting thrombin-induced platelet aggregation via suppression of the $[Ca^{2+}]_i$ level and PIS breakdown.

• 대한의용생체공학회:의공학회지
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• 제44권6호
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• pp.450-464
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• 2023

Pulse oximetry, a non-invasive technique for evaluating blood oxygen saturation, conventionally depends on isolated measurements, rendering it vulnerable to factors like illumination profile, spatial blood flow fluctuations, and skin pigmentation. Previous efforts to address these issues through imaging systems often employed red and near-infrared illuminations with distinct profiles, leading to inconsistent ratios of transmitted light and the potential for errors in calculating spatial oxygen saturation distributions. While an integrating sphere was recently utilized as an illumination source to achieve uniform red and near-infrared illumination profiles on the sample surface, its bulkiness presented practical challenges. In this work, we have enhanced the pulse oximetry imaging system by transitioning illumination from an integrating sphere to a multi-wavelength LED configuration. This adjustment ensures simultaneous emission of red and near-infrared light from the same position, creating a homogeneous illumination profile on the sample surface. This approach guarantees consistent patterns of red and near-infrared illuminations that are spatially uniform. The sustained ratio between transmitted red and near-infrared light across space enables precise calculation of the spatial distribution of oxygen saturation, making our pulse oximetry imaging system more compact and portable without compromising accuracy. Our work significantly contributes to obtaining spatial information on blood oxygen saturation, providing valuable insights into tissue oxygenation in peripheral regions.

• 한국정보처리학회:학술대회논문집
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• 한국정보처리학회 2017년도 춘계학술발표대회
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• pp.831-832
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• 2017

링크드오픈데이터를 통해 다양한 분야의 RDF 데이터가 공개되고 있으며 그 양이 지속적으로 증가하고 있다. RDF 데이터는 그래프 형태이기 때문에 대용량 RDF 데이터를 효율적으로 관리하기 위한 그래프 데이터베이스에 대한 연구가 중요하다. 2개의 RDF 리소스가 그래프 상에서 연결됐는지 여부를 알아내는 기능은 RDF 요소간 연관관계를 식별하는 데에 관련이 있기 때문에 그래프 데이터베이스의 중요한 기능 중 하나이다. 대용량 그래프 데이터에 대한 그래프 도달가능성을 빠르게 처리하기 위해서 2-Hop 레이블링 변형들이 제안됐다. 최근에 2-Hop 레이블 크기를 줄이기 위해 2-Hop 레이블링이 진행되기 전에 노드 아이디를 부여하는 방법이 제안됐다. 하지만 그래프의 지역 정보만을 활용하기 때문에 복잡한 형태의 그래프에 대해서는 비효율적이라는 문제점이 있다. 본 논문에서는 그래프의 전역 정보를 반영할 수 있는 Topological Sort를 활용한 노드 아이디 부여 기법에 대한 설계를 제안한다.

• 대한의생명과학회지
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• 제10권4호
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• pp.523-528
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• 2004

The core factor of the study is integrated environment based PC-Cluster system and high speed access rate up to 155 Mbps, continuous collection system for bioinformatics information at home and abroad. The results of the study are establishment and stabilization of information and communication infrastructure, establishment and stabilization of high performance computer network up to 155 Mbps, development of PC-Cluster system with 32 nodes, a parallelized BLAST on Cluster system, which can provides scalable speedup in terms of response time, and development of collection and search system for bioinformatics information.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제4권5호
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• pp.956-967
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• 2010

Rapid growth of internet applications has increased the importance of intrusion detection system (IDS) performance. String matching is the most computation-consuming task in IDS. In this paper, a new algorithm for multiple string matching is proposed. This proposed algorithm is based on the canonical Aho-Corasick algorithm and it utilizes a bidirectional and parallel processing structure to accelerate the matching speed. The proposed string matching algorithm was implemented and patched into Snort for experimental evaluation. Comparing with the canonical Aho-Corasick algorithm, the proposed algorithm has gained much improvement on the matching speed, especially in detecting multiple keywords within a long input text string.

• 대한전자공학회:학술대회논문집
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• 대한전자공학회 2006년도 하계종합학술대회
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• pp.819-820
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• 2006

The purpose of this study is to develop an automatic algorithm to detect the arousal events. The proposed method is based on time-frequency analysis and the support vector machine classifier using single channel electroencephalogram. To extract features, first we computed 6 indices to find out the information of sleep states. Next powers of each of 4 frequency bands were computed using spectrogram of arousal region. And finally we computed variations of power of EEG frequency to detect arousals. The performance has been assessed using polysomnographic recordings of twenty patients with sleep apnea, snoring and excessive daytime sleepiness. We have shown that proposed method was effective for detecting the arousal events.

• 한국정보처리학회:학술대회논문집
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• 한국정보처리학회 2016년도 춘계학술발표대회
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• pp.80-81
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• 2016

기계가 읽을 수 있는 형태의 정보로 구성된 시맨틱웹 환경이 주목을 받고 있다. 온톨로지는 정보를 구조적으로 표현하는 방법론의 일종으로 시맨틱웹에서 중요한 역할을 한다. 사람이 일일이 정보를 처음부터 온톨로지로 만드는 것은 쉽지 않기 때문에 관계형 데이터베이스를 온톨로지로 자동으로 변환하는 연구가 진행되고 있다. 최근 하둡을 활용하여 관계형 데이터베이스의 뷰 정의로부터 상하위 관계를 추출하는 연구가 제안 됐다. 하지만, 하둡은 디스크 기반이기 때문에 속도가 느리다는 단점이 있다. 본 논문에서는 관계형 데이터베이스의 뷰 정의로부터 상하위 관계를 추출하는 과정을 인메모리 분산 처리 시스템인 스파크에서 수행하는 방법을 제안한다. 주어진 뷰 정의에 있는 테이블 이름으로 분산시킨 후 각각에서 독립적으로 상하위 관계를 추출한다.