• 전자공학회논문지C
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• 제36C권2호
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• pp.54-61
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• 1999

본 논문은 무선 적외선 데이터 전송을 위한 4-Mbps 송 . 수신기 칩의 설계에 관한 것이다. 수신부는 아날로그 프런트-엔드, 클럭 복원 및 프레임 발생 회로, 복조기로 이루어져 있으며 송신부는 변조기와 발광 다이오드 구동기로 이루어져 있다. 여러 단의 증폭기로 구성된 아날로그 프런트-엔드는 DC 크기 및 오프셋 성분을 보상함으로써 다양한 적외선 송 . 수신 환경으로의 적용을 가능하게 하였다. 데이터 변. 복조는 4-Mbps 데이터 전송 방식인 4PPM (pulse position modulation) 방식을 사용하여 IrDA 규격과 호환성을 맞추었다. 설계한 $0.8-{\mu}m$ 2-poly, 2-metal CMOS 표준공정을 사용하여 제작하였으며, ${\pm}2.5V$의 전원 전압에 대하여 소비 전력은 122mW이다.

• 대한전자공학회논문지TC
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• 제47권7호
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• pp.8-17
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• 2010

유비쿼터스홈은 댁내 뿐 아니라 휴대폰, 노트북 및 사무실 PC 등 댁외 개인기기를 포함하는 논리적인 영역을 포함한다. 이러한 기기 간에는 NAT, 방화벽 등 기기 간 네트워킹을 제한하는 요소가 존재한다. 또한 댁내에는 IP, IEEE1394, PLC, 블루투스, ZigBee, UWB, IrDA 등 물리적 전송 특성 및 프로토콜이 상이하여 상호 연동이 불가한 이종 네트워크 내에 다양한 기기가 공존하고 있다. 사용자가 원하는 서비스를 제공하기 위하여 각 기기 간 서비스 및 자원의 자유로운 조합이 필수적인 유비쿼터스홈 환경에서는 댁내외 이종 기기 간 자유로운 서비스 연동이 필수적으로 보장되어야 한다. 본 논문에서는 유비쿼터스홈에서 기기 간 seamless 통신을 제공하는 가상 오버레이 네트워크를 기반으로 댁내외 이종 기기 간 서비스의 자유로운 광고, 검색 및 엑세스를 제공하는 네트워킹 모델을 제시한다.

• 융합신호처리학회논문지
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• 제6권3호
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• pp.127-133
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• 2005

본 논문에서는 홈 네트워크 시스템 상에서의 VoiceXML을 이용한 음성 인터페이스를 제안한다. 기존의 홈 네트워크 인터페이스는 블루투스, IrDA, 무선 LAN, Home RF를 사용하지만 집 외부와 같은 원거리에서 사용 할 수 없거나 사용방법이 어려웠다. 본 논문에서 제안한 VoiceXML 음성 인터페이스는 다른 인터페이스 기술들 보다 원거리에서 사용자가 홈 네트워크 서비스를 지원 받을 수 있으며 또한 유무선 전화를 사용하여 흠 서버를 제어하며 VoiceXML server를 통하여 사용자에게 직접 전화를 걸어 문제점을 알려줄 수 있다. 본 논문에서는 이러한 음성 인터페이스를 홈 네트워크 측면에서 활용하였고 실질적인 원격검침, 원격제어 서비스를 구현한다. 그리고 이를 기초로 제안한 방식의 효율성을 평가한다.

• 한국자동차공학회논문집
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• 제23권2호
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• pp.199-207
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• 2015

Solid materials of ammonia sources with SCR have been considered for the application of lean NOx reduction in automobile industry, to overcome complex problems of liquid urea based SCR. These solid materials produce ammonia gas directly with proper heating and can be packaged by compact size, because of high volumetric ammonia density. Among ammonium salts and metal ammine chlorides, calcium ammine chloride was focused on this paper due to low decomposition temperature. In order to make calcium ammine chloride in lab-scale, simple reactor and glove box was designed and built with ammonium gas tank, regulator, and sensors. Basic test conditions of charging ammonia gas to anhydrous calcium chloride are chosen from equilibrium vapor pressure by Van't Hoff plot based on thermodynamic properties of materials. Synthetic method of calcium ammine chloride were studied for different durations, temperatures, and pressures with proper ammonia gas charged, as a respect of ammonia gas adsorption rate(%) from simple weight calculations which were confirmed by IC. Also, lab-made calcium ammine chloride were analyzed by TGA and DSC to clarify decomposition step in the equations of chemical reaction. To understand material characteristics for lab-made calcium ammine chloride, DA, XRD and FT-IR analysis were performed with published data of literature. From analytical results, water content in lab-made calcium ammine chloride can be discovered and new test procedures of water removal were proposed.

• 한국자원식물학회지
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• 제31권6호
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• pp.641-651
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• 2018

Floral scents and metabolites from cut flowers of 14 peony cultivars (Paeonia lactiflora Pall.) were analyzed to discriminate different cultivars and to compare the Korean cultivar with the other cut peonies imported to Korea using electronic nose (E-nose) and Fourier transform infrared (FT-IR) spectroscopy combined with multivariate analysis, respectively. Principal component analysis (PCA) and discriminant function analysis (DFA) dendrogram of peony floral scents were not precisely same but there were 3 groups including same cultivars. PCA and partial least squares-discriminant analysis (PLS-DA) dendrograms of peony metabolites showed that different cut peony cultivars were clustered into two major groups including same cultivars. Fragrance pattern of Korean 'Taebaek' was classified to same group with 'Jubilee' on the PCA and DFA results and its metabolite pattern was clearly discriminated by the PCA and PLS-DA compared to the other cultivars. These results show that the 14 peony cut flowers could be discriminated corresponding to their chemical relationship and the metabolic profile of Korean 'Taebaek' has distinctive characteristics. Furthermore, we suggest that these results could be used as the preliminary data for breeding new cut peony cultivars and for improving the availability of Korean cut peony in cosmetic industry.

• Molecules and Cells
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• 제41권10호
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• pp.909-916
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• 2018

In pancreatic ${\beta}$ cells, glucose stimulates the biosynthesis of insulin at transcriptional and post-transcriptional levels. The RNA-binding protein, polypyrimidine tract-binding protein 1 (PTBP1), also named hnRNP I, acts as a critical mediator of insulin biosynthesis through binding to the pyrimidine-rich region in the 3'-untranslated region (UTR) of insulin mRNA. However, the underlying mechanism that regulates its expression in ${\beta}$ cells is unclear. Here, we report that glucose induces the expression of PTBP1 via the insulin receptor (IR) signaling pathway in ${\beta}$ cells. PTBP1 is present in ${\beta}$ cells of both mouse and monkey, where its levels are increased by glucose and insulin, but not by insulin-like growth factor 1. PTBP1 levels in immortalized ${\beta}$ cells established from wild-type (${\beta}IRWT$) mice are higher than levels in ${\beta}$ cells established from IR-null (${\beta}IRKO$) mice, and ectopic re-expression of IR-WT in ${\beta}IRKO$ cells restored PTBP1 levels. However, PTBP1 levels were not altered in ${\beta}IRKO$ cells transfected with IR-3YA, in which the Tyr1158/1162/1163 residues are substituted with Ala. Consistently, treatment with glucose or insulin elevated PTBP1 levels in ${\beta}IRWT$ cells, but not in ${\beta}IRKO$ cells. In addition, silencing Akt significantly lowered PTBP1 levels. Thus, our results identify insulin as a pivotal mediator of glucose-induced PTBP1 expression in pancreatic ${\beta}$ cells.

• Elastomers and Composites
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• 제44권4호
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• pp.455-465
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• 2009

본 연구에서는 층상실리케이트에 Octylamine(OA), Dodecylamine(DA), Dimethyldodecylamine(DDA), Octadecylamine(ODA)와 같은 아민류을 사용하여 Organo-montmorillonite(MMT)를 합성한 후 Natural Rubber(NR)와 혼합하여 NR/MMT 나노복합체를 제조하였다. Organo-MMT 및 NR/MMT 나노복합체의 층간거리는 XRD를 사용하여 측정하였으며 NR/MMT 나노복합체의 모폴로지는 SEM을 통하여 관찰하였다. Organo-MMT의 구조분석은 FT-IR을 사용하였다. NR/MMT 나노복합체의 표면 자유에너지, 가황특성, 인장강도, 모듈러스 및 경도는 Contact angle meter, ODR, UTM 및 경도계로 관찰하였다. FT-IR 구조분석으로 MMT 층간에 알킬암모늄 이온의 도입을 확인하였다. 스코치 시간과 적정 가황 시간은 Organo-MMT를 사용한 경우에 단축되었다. NR/DDA-MMT 나노복합체의 표면 자유에너지와 인장강도가 가장 컸다. NR/ODA-MMT 나노복합체의 경도는 가장 컸다.

• Journal of Radiation Protection and Research
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• 제34권2호
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• pp.49-54
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• 2009

Mitochondrial DNA (mtDNA) deletion is a well-known marker for oxidative stress and aging and also contributes to their unfavorable effects in cultured cells and animal tissues. This study was conducted to investigate the effect of ionizing radiation (IR) on mtDNA deletion and the involvement of reactive oxygen species (ROS) in this process in human lung fibroblast (IMR-90) cells. Young IMR-90 cells at population doubling (PD) 39 were irradiated with $^{137}Cs$ $\gamma$-rays and the intracellular ROS level was determined by 2',7'-dichlorofluorescein diacetate (DCFH-DA) and mtDNA common deletion (4977bp) was detected by nested PCR. Old cells at PD 55 and $H_2O_2$-treated young cells were compared as the positive control. IR increased the intracellular ROS level and mtDNA 4977 bp deletion in IMR-90 cells dose-dependently. The increases of ROS level and mtDNA deletion were also observed in old cells and $H_2O_2$-treated young cells. To confirm the increased ROS level is essential for mtDNA deletion in irradiated cells, the effects of N-acetylcysteine (NAC) on IRinduced ROS and mtDNA deletion were examined. 5 mM NAC significantly attenuated the IR-induced ROS increase and mtDNA deletion. These results suggest that IR induces the mtDNA deletion and this process is mediated by ROS in IMR-90 cells.

• Korean Chemical Engineering Research
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• 제51권6호
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• pp.780-783
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• 2013

저분자량의 laminarin은 항산화능과 같은 생물학적 물성이 고분자량의 laminarin과 비교하여 증가하였다는 최근의 연구 결과들이 보고되었다. 이러한 저분자화에 따른 laminarin 생물활성의 증가 원인을 밝히고자 본 논문에서는 이온화 방사선 조사를 통하여 얻어진 저분자량 laminarin의 분자구조에 관한 연구를 수행하였다. 15 kDa 크기의 분자량을 갖는 laminarin을 이온화 방사선 조사를 이용하여 13.5, 8.5, 7, 6 kDa 크기의 저분자량 laminarin 시료들을 얻었다. 얻어진 저분자량 laminarin은 고분자량 laminarin에 비하여 낮은 polydispersity 값을 가졌다. 방사선 조사에 의한 저분자화에 따른 laminarin 기능기들의 변화를 확인하기 위하여 Fourier-transform infrared 분석을 수행한 결과, 분자량 감소에 따라서 대부분의 기능기들의 변화는 관찰되지 않았지만, carbonyl group의 증가가 확인되었다. Laminarin 입자의 scanning electron microscopy 분석으로부터 저분자량 laminarin에서 glycosidic 결합의 분해에 의한 입자 균열이 확인되었다. 이러한 결과들은 laminarin과 같은 다당류의 저분자화에 따른 기능성 변화 연구에 활용될 수 있을 것으로 기대된다.

• 한국식품영양과학회지
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• 제28권2호
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• pp.285-291
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• 1999

To confirm the food quality of Urechis unicinctus which have been favored as a special raw seafood in southern area in Korea, the chemical composition of Urechis unicinctus and those glycoprotein were studied. Freeze dried Urechis unicinctus was composed of more than 70% of crude protein and 15% of total carbohydrate. The amino acids such as glycine(18.69%), glutamic acid(12.50%) and aspartic acid(9.37%) were noted as major components of total amino acids. The predominant free amino acids were alanine(32.98%), glycine(27.50%), asparagine(19.65%) and taurine(8.29%), and the sum of them were more than 88% to total free amino acids, so they may cause unique taste of Urechis unicinctus with sweetness. As the basis of sugar composition analysis, 56.35% of glucose and 30.49% of N acetylglucosamine were contained respectively, and they might also play an important role in a sweet taste. The leading carbohydrate moiety of glycoprotein from Urechis unicinctus was identified as glucose and N acetylglucosamine similarly to raw muscle, and they occupied more than 50% of total sugar content. Fucose(18.32%) and D glucuronic acid(12.31%) also detected in higher levels com pared to raw muscle. The total amino acid profile of glycoprotein showed a similar trend to raw muscle protein but glycine was detected a significantly lower than that in raw muscle. The glycoprotein from Urechis unicinctus was composed of 4 kinds of subunits, i.e. 25kDa, 20kDa, 18kDa and 12.5kDa of molecular weights through the SDS polyacrylamide gel electrophoresis. On the basis of the IR spectrum of absorptions appeared in 1,240cm-1 and 850cm-1, the glycoprotein had sulfate groups.