• IMMUNE NETWORK
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• 제4권3호
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• pp.143-154
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• 2004

Background: CD27 is recently known as a memory B cell marker and is mainly expressed in activated T cells, some B cell population and NK cells. CD27 is a member of tumor necrosis factor receptor family. Like CD40 molecule, CD27 has (P/S/T/A) X(Q/E)E motif for interacting with TNF receptor-associated factors (TRAFs), and TRAF2 and TRAF5 bindings to CD27 in 293T cells were reported. Methods: To investigate the CD27 signaling effect in B cells, human CD40 extracellular domain containing mouse CD27 cytoplamic domain construct (hCD40-mCD27) was transfected into mouse B cell line CH12.LX and M12.4.1. Results: Through the stimulation of hCD40-mCD27 molecule via anti-human CD40 antibody or CD154 ligation, expression of CD11a, CD23, CD54, CD70 and CD80 were increased and secretion of IgM was induced, which were comparable to the effect of CD40 stimulation. TRAF2 and TRAF3 were recruited into lipid-enriched membrane raft and were bound to CD27 in M12.4.1 cells. CD27 stimulation, however, did not increase TRAF2 or TRAF3 degradation. Conclusion: In contrast to CD40 signaling pathway, TRAF2 and TRAF3 degradation was not observed after CD27 stimulation and it might contribute to prolonged B cell activation through CD27 signaling.

• Bulletin of the Korean Chemical Society
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• 제33권8호
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• pp.2603-2608
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• 2012

A novel mononuclear supramolecule of copper(II) has been synthesized with Ippyt ligand (Ippyt=3-(4'-imidazole phenyl)-5-(pyrid-2''-yl)-1,2,4-triazole) (1). Compound 1, namely [$Cu(Ippyt)_2(H_2O)_2$], has been characterized by single-crystal X-ray diffraction, IR spectrum, elemental analysis and thermogravimetric analysis. Structure determination reveals that the elongated-octahedral geometry is formed in the vicinity of the copper (II) atom being coordinated by four nitrogen atoms from two Ippyt ligands occupying the equatorial position and two oxygen atoms from two coordinated water molecules in the axial position, which together form the $N_4O_2$ donor set. Hydrogen bonding interactions between nitrogen and oxygen atoms result in the set up of a supramolecular network architecture. Biological properties including antibacterial activity and superoxide dismutase (SOD) mimetic activity of compound 1 have been investigated by agar diffusion method and the modified Marklund method, respectively. The results indicate that compound 1 exhibits a stronger antibacterial efficiency than the parent ligand and it also has a certain radical-scavenging activity.

• 대한전자공학회논문지SD
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• 제42권12호
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• pp.71-78
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• 2005

이 논문에서는 비동기 OOK 방식의 UWB 시스템에서 사용할 수 있는 아날로그 송수신단을 설계하였다. 설계한 송수신단은 $0.18{\mu}m$ CMOS 공정을 사용하여 구현 하였으며, SPICE 모의실험과 측정을 통하여 검증을 하였다. 제안된 송수신단은 병렬기, 아날로그-디지털 변환기, 클럭 생성기, 위상고정루프(PLL), 그리고 임펄스 생성기 등으로 이루어져 있다. 동작속도는 125MHz로 동작하는 아날로그-디지털 변환기 8개를 병렬로 연결하여 1Gbps의 속도를 얻으며, 8개의 병렬화된 출력을 얻는다. 이 출력은 D-F/F에 의해 동기화되고, 이 동기화된 출력들은 기저대역으로 전달된다. 임펄스 생성기는 CMOS 디지털 게이트로 이루어져 있으며, 약 1ns의 폭을 가지는 임펄스를 생성한다. 본 논문에서 제안된 송수신단의 모의실험 결과와 측정결과는 저전력 UWB 시스템의 구현이 가능하고, 병렬화를 택해서 높은 데이터 전송률을 얻을 수 있다는 가능성을 보여준다.

• 지적과 국토정보
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• 제44권1호
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• pp.1-15
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• 2014

본 연구에서는 문헌고찰을 통해 생태계와 공간정보생태계 모형 개발을 위한 기본 요건을 도출한 후에 이를 전제로 공간정보산업을 중심으로 공간정보생태계 모형을 개발 제시하였다. 다음으로, 국내 공간정보산업 발전이 미진한 근본적 원인이 생태계가 비활성화되어 효율적이지 못한 데 있으므로, 향후 공간정보생태계를 활성화하는 데 필요한 관련 기관들의 역할을 논의하였다. 특히 국내 공간정보생태계 활동주체의 대표 격이라고 할 수 있는 대한지적공사가 공익성과 사익성을 동시에 추구하는 이중적인 기관특성을 유지한 채, 미래지향적인 역할과 기능 재정립을 통해 생태계의 타 구성주체와 상호협력하면서 함께 발전하는 공진화 전략 대안을 4가지로 요약해 제안하였다.

• 정보통신설비학회논문지
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• 제2권4호
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• pp.5-16
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• 2003

Parallel Coupler Access Encoder(PCAE)와 Parallel Coupler Access Decoder(PCAD)를 이용한 FO-CDMA(Fiber-Optic Code Division Multiple Access)시스템에서 광정합필터 특성을 실험을 통해 분석하였다. PCAE와 PCAD를 구성하고 있는 즉, 1xN splitter와 Nx1 combiner사이에 접속된 광지연선로의 길이비율을 광직교코드 생성알고리즘에 의해 결정하였고, 부/복호화 과정 및 시그템 성능을 peak to side-lobe ratio(PSR)를 구하여 기존에 제시된 결과와 비교하였다. 기존의 연구에서는 SCAE 및 SCAD를 이용하여 일차신호만을 고려하여 시스템의 성능을 분석하여 성능평가가 정확하지가 않았다. SCAE 및 SCAD는 커플러수를 증가함에 따라 여러 형태의 간섭신호들을 가지므로, 이러한 신호들이 시스템 성능을 현저히 열화 시킨다. 본 논문에서는 $\alpha$(coupling coefficient)값이 커질수록 PCAE와 PCAD를 이용한 PSR이 향상됨을 밝혔고 FO-CDMA 통신망의 성능을 개선하기 위해서는 SCAE와 분석 SCAD 구조보다는 PCAE와 PCAD 구조가 적합함을 제시하였다.

• 대한교통학회지
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• 제17권4호
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• pp.111-124
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• 1999

본 논문의 목적은 최근에 개발 중에 있는 단일 자석검지기를 이용한 차종인식 알고리즘을 개발하고, 현장실험을 통한 현장 적용성을 검토하는 것이다. 고속도로에 설치되어 이는 자석검지기를 이용하여 자료를 수집하며 분석에 이용되는 자료는 개별차량에 대하여 자속밀도의 변화에 따른 전압 값을 Digital Data값으로 변환한 수치를 사용하였다. 그 수치를 토대로 각 차량의 점유시간을 파악하여 각 차량의 점유시간동안 파형의 특징을 추출하여 각 특징들을 기초로 하여 각 차량이 나타내는 고유의 파형을 식별하는 Template Matching 방법과 신경망기법, 그리고 이들을 상호 보완한 복합기법을 사용하였다. 검지차량에 따른 다양한 점유시간을 일정크기로 수평성분 정규화하고 이에 따른 자속속밀도의 변화에 의한 전압 값을 차종별로 샘플을 취하여 이동평균방법으로 처리를 한 후 위의 세 가지 기법을 사용하여 검지차량의 파형과 기준 파형을 비교하여 차종을 인식하는 방법으로 알고리즘을 개발하였다. 차종의 분류는 3가지 단계로 하였는데 2종분류, 3종분류, 5종분류로 접근하였다. 그리고 각각의 분류에 따라 정규화 크기 및 이동평균간격을 달리하여 적용하여 보았고 2종분류에서 인식율이 82%수준이다.

• IMMUNE NETWORK
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• 제8권4호
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• pp.137-142
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• 2008

Background: CD11c, also known as integrin alpha x, is one of the optimum markers of dendritic cells. However, the regulation of the CD11c expression in mouse has not been identified yet. In this study, in order to analyze the regulation of CD11c expression, the promoter of CD11c was cloned and characterized. Methods: To identify the promoter portion, various sizes of what are considered to be CD11c promoter fragments was amplified by polymerase chain reaction (PCR), using mouse genomic DNA as a template. After sequence was obtained, these fragments were transfected into various cell lines including mouse dendritic cell lines such as JAWSII and DC2.4 and L929 as control cell line.. The promoter activity of three promoter fragments was measured and compared by luciferase activity in the transfected cells. Results: Three clones with size of 1kb, 3kb and 6kb were obtained from mouse genomic DNA. Flow cytometry analysis of JAWSII cells revealed that 52% of the cells expressed CD11c, which was confirmed by RT-PCR analysis. On the contrary, L929 and DC 2.4 cells did not express CD11c. The CD11c+ JAWSII cells were enriched from 52% to 90% with cell sorter. The comparative luciferase activity analyisis demonstrated that the region responsible for tissue specific expression was contained within -3 kb and the clone with size of 3 kb particularly showed higher luciferase activity than 6 kb and 1 kb clones. Conclusion: The CD11c promoter region containing the region responsible for tissue specificity was successfully cloned and -3 kb region showed the highest activity.

• International Journal of Oral Biology
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• 제37권1호
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• pp.9-16
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• 2012

The aim of this study was to evaluate surface characteristics and biological properties of the dentin -derived hydroxyapatite (HA) coating on titanium substrate. Dentinderived HA was obtained from extracted human teeth using a calcination method at $850^{\circ}C$. The commercially pure titanium (cp-Ti, ASTM Grade II) was used as a metallic substrate and a radio frequency magnetron sputtering method was employed as a coating method. Scanning electron microscopy (SEM) and energy dispersive X-ray analysis (EDX) were utilized to investigate the coating aspects and composition. Atomic forced microscopy (AFM) and a surface profiler were used to assess the surface morphology and roughness. Corrosion tests were performed in phosphate-buffered saline at a $36.5{\pm}1^{\circ}C$ in order to determine the corrosion behavior of the uncoated and coated specimens. The biocompatibility of dentin-derived HA coated specimens with fetal rat calvarial cells and human gingival fibroblasts was assessed by SEM and cell proliferation analysis. The results showed that the dentin-derived HA coatings appeared to cover thinly and homogeneously the surfaces without changing of the titanium substrate. The EDX analysis of this the coating surface indicated the presence of Ca and P elements. The mean surface roughness of cp-Ti and dentin-derived coating specimens was $0.27{\mu}m$ and, $1.7{\mu}m$, respectively. Corrosion tests indicated a stable passive film of the dentin-derived HA coating specimens. SEM observations of fetal rat calvarial cells and human fibroblast cells on coated surfaces showed that the cells proliferated and developed a network of dense interconnections. The cells on all specimens proliferated actively within the culture period, showing good cell viability. At day 1 and 3, dentin-derived coating specimens showed 89% and 93% cell viability, respectively, when normalized to cp-Ti specimens. These results suggest that dentin-derived HA coating using the RF magnetron sputtering method has good surface characteristics and biocompatibility.

• Imaging Science in Dentistry
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• 제50권1호
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• pp.45-52
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• 2020

Purpose: This study was conducted to develop an evidence-based clinical imaging diagnostic guideline for implant planning, taking into account efficacy, benefits, and risks. Materials and Methods: The guideline development process employed the adaptation methodology used for Korean clinical imaging guidelines(K-CIG). Core databases(Ovid-Medline, Ovid-Embase, National Guideline Clearinghouse, Guideline International Network) and domestic databases (KoreaMed, KMbase, and KoMGI) were searched for guidelines. The retrieved articles were analyzed by 2 reviewers, and articles were selected using well-established inclusion criteria. Results: The search identified 294 articles, of which 3 were selected as relevant guidelines. Based on those 3 guidelines, 3 recommendations for implant planning were derived. Conclusion: We recommend radiography or cone-beam computed tomography (CBCT) scanning for individual patients judged to require a cross-sectional image after reading of a panoramic X-ray image and a conventional intraoral radiological image. Various steps should be taken to raise awareness of these recommendations among clinicians and the public, and K-CIG should be regularly reviewed and revised.

• 전기학회논문지
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• 제62권5호
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• pp.696-704
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• 2013

In this paper, we introduce the LED emotional lighting system realized with the aid of both intelligent algorithm and RGB LED combined with White LED. Generally, the illumination is known as a design factor to form the living place that affects human's emotion and action in the light- space as well as the purpose to light up the specific space. The LED emotional lighting system that can express emotional atmosphere as well as control the quantity of light is designed by using both RGB LED to form the emotional mood and W LED to get sufficient amount of light. RBFNNs is used as the intelligent algorithm and the network model designed with the aid of LED control parameters (viz. color coordinates (x and y) related to color temperature, and lux as inputs, RGBW current as output) plays an important role to build up the LED emotional lighting system for obtaining appropriate color space. Unlike conventional RBFNNs, Fuzzy C-Means(FCM) clustering method is used to obtain the fitness values of the receptive function, and the connection weights of the consequence part of networks are expressed by polynomial functions. Also, the parameters of RBFNN model are optimized by using PSO(Particle Swarm Optimization). The proposed LED emotional lighting can save the energy by using the LED light source and improve the ability to work as well as to learn by making an adequate mood under diverse surrounding conditions.