• Bulletin of the Korean Chemical Society
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• 제32권9호
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• pp.3433-3436
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• 2011

Some of metal nanoparticles have the potential for use as colorimetric assays for estimating solution properties, such as pH and temperature due to localized surface plasmon (LSP) phenomena. This report describes the use of silver nanoparticles (AgNP) conjugated with cytochrome c (Cyt c) for the colorimetric determination of solution pHs. When the pH of a solution decreases, the Cyt c immobilized on the AgNP undergoes a conformational change, leading to a decrease in the interparticle distance between Cyt c-AgNP probes and consequent red-shift in LSP. As a result, the color of the Cyt c-AgNP probe solution changes from yellow to red and finally to a grayish blue in the pH range from 11 to 3. This gradual color change can be used to determine the pH of a solution over a wide pH range, compared to other colorimetric methods that use gold nanoparticles.

• The Journal of the Acoustical Society of Korea
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• 제17권3E호
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• pp.53-57
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• 1998

Spectral information at a speech coder should be quantized with sufficient accuracy to keep perceptually transparent output speech. Spectral information at a low bit rate speech coder is usually transformed into corresponding line spectrum pair parameters and is often quantized with a vector quantization algorithm. As the vector quantization algorithm generally has high complexity in the optimal code vector searching routine, the complexity reduction in that routine is investigated using the ordering property of the line spectrum pair. When the proposed complexity reduction algorithm is applied to the well-known split vector quantization algorithm, the 46% complexity reduction is achieved in the distortion measure compu-tation.

• 한국통신학회논문지
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• 제36권12B호
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• pp.1450-1458
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• 2011

연구망에서 융합망이란 의료, 바이오, 항공우주, e-Science 분야 등의 응용 연구자들에게 슈퍼컴퓨터, 클러스터 등의 컴퓨팅 자원을 네트워크 자원과 동시에 동적으로 제공해 줄 수 있는 환경을 의미한다. 한국을 대표하는 연구망인 KREONET은 2008년도부터 융합망 프로젝트를 통해 다음과 같은 기술을 개발하고 있다. 먼저 이기종 네트워크 환경에서 동적으로 연결 지향형 네트워크를 구성 할 수 있는 제어평면 기술을 제공하고 있으며, 그와 더불어 사용자가 원하는 시간 때에 컴퓨팅 자원 및 네트워크 자원을 예약, 할당해 줄 수 있는 통합자원관리시스템 기술을 개발하고 있다. 본 논문에서는 개발되어진 통합자원관리시스템을 이용허여 네트워크 자원의 예약 및 할당이 가능한 테스트베드 네트워크를 소개한다. 사용자로부터 제공 되어진 예약정보를 받아 GRS와 NRM 간에, NRM와 라우터 간에 각각 GNSI, GUNI 인터페이스 메시지를 통해 네트워크 자원을 예약 할당 할 수 있다. 예약 시각의 시작시점에 NRM으로부터 GUNI 인터페이스 메시지가 각 라우터에 전달되어지고 할당된 LSP (Label Switched Path) 경로를 통해 트래픽이 전송됨을 확인하였다.

• The Journal of the Acoustical Society of Korea
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• 제20권1E호
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• pp.20-24
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• 2001

We propose the computation reduction method of real root method that is mainly used in the CELP(Code Excited Linear Prediction) vocoder. The real root method is that if polynomial equations have the real roots, we are able to find those and transform them into LSF[1]. However, this method takes much time to compute, because the root searching is processed sequentially in frequency region. But, the important characteristic of LSF is that most of coefficients are occurred in specific frequency region. So, the searching frequency region is ordered by each coefficient's distribution. And coefficients are searched in ordered frequency region. Transformation time can be reduced by this method than the sequential searching method in frequency region. When we compare this proposed method with the conventional real root method, the experimental result is that the searching time was reduced about 46% in average.

• The Journal of the Acoustical Society of Korea
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• 제18권1E호
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• pp.3-6
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• 1999

In digital mobile communication system, the transmission errors affect the quality of output speech seriously. There are many error concealment techniques using a posteriori probability which provides information about any transmitted parameter. They need knowledge about channel transition probability as well as the 1st order Markov transition probability of codec parameters for estimation of transmitted parameters. However, in applications of mobile communication systems, the channel transition probability varies depending on nonstationary channel characteristics. The mismatch of designed channel transition probability of the estimator to actual channel transition probability degrades the performance of the estimator. In this paper, we proposed a new parameter estimator which adapts to the channel characteristics using short time average of maximum a posteriori probabilities(MAPs). The proposed scheme, when applied to the LSP parameter estimation, performed better than the conventional estimator which do not adapt to the channel characteristics.

• 전자통신동향분석
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• 제31권5호
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• pp.99-109
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• 2016

IETF Path Computation Element(PCE) 그룹에서는 데이터 전송을 위한 전달 경로를 찾는 엔진 기능을 중심으로 표준화를 진행하고 있다. 망의 상태, 위상, 자원 가용성, 정책을 기반으로 최적의 자원을 할당하는 경로 계산 기능과 구조, 프로토콜 등을 정의하는데 MPLS/GMPLS 망의 제어 평면 프로토콜 기반 전송을 위주로 출발하여 광, 회선 망에서의 적용과 서비스 표준이 실제 사례를 뒷받침하여 발전되었고 현재는 데이터 센터 네트워크, SDN, IoT 분야에서의 활용이 활발하게 논의되고 있다. 본고에서는 경로 계산 기능의 분산을 주요 목적으로 하여 이제는 범용의 전달망 관리 분야로 확대 적용되는 추세의 active stateful PCE와 Traffic Engineering Database (TED), Label Switched Path DB(LSP-DB), PCE Protocol(PCEP) 등을 포함한 관련 표준 현황을 살펴보고 향후 통합 전달망 제어 관리 진화 방향을 소개하고자 한다.

• Biomolecules & Therapeutics
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• 제23권2호
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• pp.110-118
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• 2015

According to the expansion of lifespan, neuronal disorder based on inflammation has been social problem. Therefore, we isolated shikonin from Lithospermum erythrorhizon and evaluated anti-inflammatory effects of shikonin in lipopolysaccharide (LSP)-stimulated BV2 microglial cells. Shikonin dose-dependently inhibits the expression of the proinflammatory mediators, nitric oxide (NO), prostaglandin $E_2$ ($PGE_2$), and tumor necrosis factor-${\kappa}B$ (TNF-${\alpha}$) as well as their main regulatory genes and products such as inducible NO synthase (iNOS), cyclooxygenase-2 (COX-2), and TNF-${\alpha}$ in LPS-stimulated BV2 microglial cells. Additionally, shikonin suppressed the LPS-induced DNA-binding activity of nuclear factor-${\kappa}B$ (NF-${\kappa}B$) to regulate the key regulatory genes of the proinflammatory mediators, such as iNOS, COX-2, and TNF-${\alpha}$, accompanied with downregulation of reactive oxygen species (ROS) generation. The results indicate that shikonin may downregulate the expression of proinflammatory genes involved in the synthesis of NO, $PGE_2$, and TNF-${\alpha}$ in LPS-treated BV2 microglial cells by suppressing ROS and NF-${\kappa}B$. Taken together, our results revealed that shikonin exerts downregulation of proinflammatory mediators by interference the ROS and NF-${\kappa}B$ signaling pathway.

• 한국가금학회:학술대회논문집
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• 한국가금학회 2000년도 제17차 정기총회 및 학술발표
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• pp.63-65
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• 2000

Two experiments were conducted to investigate the effects of feeding single or combined probiotics on performance and intestinal microflora of broiler chicks for five weeks. Diets based on corn and soybean meal contained 21.50, 19.0% CP and 3,100, 3,150 kcal/kg ME for starting and finishing period, respectively. Lactobacillus salvarius isolated from chicks intestine(LSC), Lactobacillus salvarius isolated from piglet(LSP) Bacillus polyfermenticus(BP) were fed with alone and mixed ones at the level of 0.21 and 0.1% in experiment 1 and 2. Three hundred eighty four chicks were randomly assigned to eight treatment with four replicates of 12 chicks each per treatment. Weight gain, feed consumption, feed conversion ratio(FCR) were weekly measured for 5 weeks. The number of intestinal microflora was examined at the end of experiment. There were no significant different weight gain of all treatment in both experiments. Feed consumption were not shown consistency. Chicks fed LSC alone showed the lowest feed conversion ratio of all treatment in experiment 1, but was not consistency in experiment 2. The number of Lactobacillus spp. tended to increase in chicks ileum fed probiotics treatments, whereas it was not consistency in cecum. The number of ileal E. coli was not decreased in BP treatment.

• 한국자원식물학회:학술대회논문집
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• 한국자원식물학회 2019년도 춘계학술대회
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• pp.113-113
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• 2019

Diallyl trisulfide (DATS) is an organic polysulfide compound found in garlic. Although certain studies have demonstrated that DATS possesses strong anti-inflammatory activity, the underlying molecular mechanisms remain largely unresolved. In this study, we examined whether DATS exerts anti-inflammatory activity and investigated the possible mechanisms. Our results indicated that DATS significantly suppressed the lipopolysaccharide (LPS)-induced release of nitric oxide (NO) and prostaglandin E2 by inhibiting inducible NO synthase and cyclooxygenase-2 expression at the transcriptional and post-transcriptional levels in RAW 264.7 macrophages. DATS also down-regulated Toll-like receptor 4 (TLR4) and myeloid differentiation factor 88 expression, and inhibited nuclear translocation of nuclear transcription factor-kappa B (NF-${\kappa}B$) in LPS-stimulated 264.7 macrophages. Furthermore, we found that these inhibitory effects of DATS were associated with the inhibition of chemokine receptor (CXCR4) and ligand (CXCL12) expression, and reactive oxygen species generation. Overall, the present data indicated that DATS had anti-inflammatory effects on LPS-activated macrophages, possibly via inhibiting the TLR4/NF-kB and/or chemokine signaling pathways, and DATS could be a potential drug therapy for inflammation and its associated diseases.

• 한국진공학회:학술대회논문집
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• 한국진공학회 2013년도 제44회 동계 정기학술대회 초록집
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• pp.105-106
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• 2013

Surface plasmon resonance (SPR) is classified into the propagating surface plasmon (PSP) excited on flat metal surfaces and the local surface plasmon (LSP) excited by metalnanoparticles. It is known that fluorescence signals are enhanced by these two SPR-fields.On the other hand, fluorescence is quenched by the energy transfer to metal (FRET). Bothphenomena are controlled by the distance between dyes and metals, and the degree offluorescence enhancement is determined by the correlation. In this study, we determined thecondition to achieve the maximum fluorescence enhancement by adjusting the distance of ametal nanoparticle 2D sheet and a quantum dots 2D sheet by the use of $SiO_2$ spacer layers. The 2D sheets consisting of myristate-capped Ag nanoparticles (AgMy nanosheets) wereprepared at the air-water interface and transferred onto hydrophobized gold thin films basedon the Langmuir-Schaefer (LS) method [1]. The $SiO_2$ sputtered films with different thickness (0~100 nm) were deposited on the AgMy nanosheet as an insulator. TOPO-cappedCdSe/CdZnS/ZnS quantum dots (QDs, ${\lambda}Ex=638nm$) [2] were also transferred onto the $SiO_2$ films by the LS method. The layered structure is schematically shown in Fig. 1. The result of fluorescence measurement is shown in Fig. 2. Without the $SiO_2$ layer, the fluorescence intensity of the layered QD film was lower than that of the original QDs layer, i.e., the quenching by FRET was predominant. When the $SiO_2$ thickness was increased, the fluorescence intensity of the layered QD film was higher than that of the original QDs layer, i.e., the SPR enhancement was predominant. The fluorescence intensity was maximal at the $SiO_2$ thickness of 20 nm, particularly when the LSPR absorption wavelength (${\lambda}=480nm$) was utilized for the excitation. This plasmonic nanosheet can be integrated intogreen or bio-devices as the creation point ofenhanced LSPR field.