• 정보처리학회논문지D
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• 제9D권1호
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• pp.1-10
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• 2002

메타데이터는 데이터에 관한 데이터로 데이터를 관리하기 위하여 사용된다. 데이터베이스를 기반으로 하는 응용프로그램이 증가하면서 메타데이터를 관리하기 위해 XML(eXtensible Markup Language)형식의 메타데이터 모델 및 메타데이터 교환모델이 제안되고 있지만 XML형식의 메타데이터를 관계형 데이터베이스에 저장하는 것이 일반적이다. 따라서 본 논문에서는 관계형 데이터베이스의 메타데이터를 객체지향 데이터베이스에 저장하기 위해 메타데이터 모델과 메타데이터 교환모델을 설계하여 메타데이터를 관리하는 새로운 리파지토리 시스템 구현을 목적으로 한다. 관계형 데이터베이스의 메타데이터를 XML문서로 변형 후 객체지향 데이터베이스의 XML 데이터 서버인 eXcelon에 저장하여 XQL (XML Query Language)에 의해 질의함으로써 관계형 데이터베이스 시스템들의 메타데이터의 검색, 편집을 가능하도록 하고 XSL(extensible StyleSheets Language)의 적용을 통하여 다양한 양식으로 웹 브라우져 상에 메타데이터를 출력함으로써 메타데이터의 속성을 면밀히 파악할 수 있다.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1999년도 하계학술대회 논문집 D
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• pp.1867-1869
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• 1999

Pulse electric field induced electron emission from ferroelectrics has been studied with Pb$(Zr_xTi_{1-x})O_3$ ceramics with varying Zr/Ti ratio from 35/65 to 65/35, Electron emission was proved to be concentrated on the electrode edge by emission profile test and emission capture photographs. The 65/35 composition showed largest emission charge in lowest field and lowest emission threshold field. The emission characteristics are closely dependent on their ferroelectric properties in hysteresis curve. Electron emission charge increases with the polarization charge and emission threshold voltage is dependent on coercive field regardless of their composition. But dielectric constant has little relation with emission property. Electron emission charge increases exponentially with pulse electric field irrespective of composition. On the assumption that the surface potential is linear with the pulse electric field, electron emission can be regarded as a field emission at the electrode edge using Fowler-Nordheim plot of ln$(Q_e/E_{fe})$ to $1/E_{fe}$.

• 한국통신학회논문지
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• 제35권7B호
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• pp.1073-1080
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• 2010

최근, 국제적으로는 e-Navigation을 지향하는 해상안전에 대한 연구가 활발하고, 국내외적으로 발생되는 해상사고로부터 발생되는 막대한 환경 인명 재산 피해에 대한 국민적 인식에 따라 해상관제기술에서 최신IT산업의 융합 필요성이 제기되어 왔다. 따라서 본 논문에서는 해상의 상황을 인지하고, 선박의 위치 뿐만 아니라 선박의 상황과 의도에 기반한 차세대 해상교통관제시스템을 설계하고 이를 통하여 의사결정지원(DSS)과 항행지원 구조를 설계하였다. 제안 시스템을 통하여 운항 선박의 상황확인, 추론, 위험관리를 통한 의사결정지원과 항행지원을 통하여 보다 시의적절한 정보를 제공하여 선박의 운항을 쉽게 할 수 있으며, 충돌 등 위험상황을 예방할 수 있을 것이라 판단된다.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 1996년도 추계학술대회 논문집
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• pp.117-120
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• 1996

In this paper, It is tested by spraying the spoiled liquids on the materials to prove the process of tracking under the various environments. Our experiments ware examined by setting the materials in the spray chamber, and by spraying the distilled water(DW), the city water(CW), the underground water(UW), the artificial acid rain(AR) and the salt water(SW) in applied voltage 3-6[KV]. As the result, the time of tracking breakdown became shorter in the order of DW < CW < UW < AR < SW. XLPE was eroded and its anti-bracking property was very strong, but that of PVC sheath was week. Especially it was confirmed that spraying by AR and SW on the PVC sheath had a serious effect on the lifetime of cable by the tracking breakdown.

• 대한본초학회지
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• 제27권5호
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• pp.85-91
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• 2012

Objectives : In this study, we investigated the effect of Saposhnikoviae Radix on allergic responses in ovalbumin(OVA)-induced Allergic rhinitis(AR) mice. Methods : BALB/c mice were orally administrated with Saposhnikoviae Radix water extract (SRW, 50 mg/kg) or anti-histamine drug, Ketotifen (10 mg/kg) as a reference drug, followed by sensitization and challenge of OVA. Mice were measured clinical symptoms and the serum levels of histamine, IgE, IL-4, and IFN-${\gamma}$, and observed histopathological changes of nasal mucosa H&E staining. Results : SRW significantly decreased rubs and the serum levels of histamine, IgE, and IL-4, and then increased the serum levels of IFN-${\gamma}$ in OVA-induced AR mice, and inhibited histopathological changes of nasal mucosa with inflammation and the eosinophils infilteration. Conclusions : These data suggest that SRW has anti-allergic effect through the inhibitory property of Saposhnikoviae Radix against allergic responses in allergic rhinitis.

• Advances in Traditional Medicine
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• 제10권4호
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• pp.304-309
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• 2010

Scutellaria pinnatifida A. Hamilt. (Lamiaceae) is an endemic Turkish herb. This plant is also endemic to Iran, and grows abundantly in other central and western Asian countries. Several species of the Scutellaria are known for their traditional uses in the treatment of hypertension, arteriosclerosis, inflammatory diseases, hepatitis, allergy, cancer and diarrhoea. Free-radical-scavenging property, antibacterial activity and brine shrimp toxicity of the n-hexane, dichloromethane (DCM) and methanol (MeOH) extracts of S. pinnatifida were assessed using the 2,2-diphenyl-1-picryl-hydrazyl (DPPH) assay, the resazurin microtitre plate based assay, and the brine shrimp lethality assay, respectively. The DCM and MeOH extracts exhibited free-radical-scavenging property, with the $RC_{50}$ values of 0.362 and 0.127 mg/ml, respectively. Among the solid-phase extraction fractions of the MeOH extract, the 50% aqueous-MeOH fraction showed the highest level of free-radicalscavenging activity ($RC_{50}$ = 0.039 mg/ml). While the DCM extract showed low level of antibacterial activity against Bacillus subtilis and ampicillin-resistant Escherichia coli, the MeOH extract was active against B. cereus, B. subtilis, E. coli and ampicillin-resistant E. coli. However, the minimum inhibitory concentrations (MIC) of the MeOH extract against these bacterial strains were >10 mg/ml. None of the extracts showed any significant toxicity towards brine shrimps ($LD_{50}$ = > 1.00 mg/ml).

• 한국재료학회지
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• 제27권6호
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• pp.345-349
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• 2017

The effects of electron beam(EB) irradiation on the electrical and optical properties of InGaZnO(IGZO) thin films fabricated using a sol-gel process were investigated. As the EB dose increased, the electrical characteristic of the IGZO TFTs changed from semiconductor to conductor, and the threshold voltage values shifted to the negative direction. X-ray photoelectron spectroscopy analysis of the O 1s core level showed that the relative area of oxygen vacancies increased from 14.68 to 19.08 % as the EB dose increased from 0 to $1.5{\times}10^{16}electrons/cm^2$. In addition, spectroscopic ellipsometer analysis showed that the optical band gap varied from 3.39 to 3.46 eV with increasing EB dose. From the result of band alignment, it was confirmed that the Fermi level($E_F$) of the sample irradiated with $1.5{\times}10^{16}electrons/cm^2$ was located at the closest position to the conduction band minimum(CBM) due to the increase of electron carrier concentration.

• 통합자연과학논문집
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• 제9권1호
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• pp.72-79
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• 2016

Hexane, ethyl acetate and methanol extracts of whole plant of Boerhavia diffusa were screened for phytochemical and biological activities. Qualitative phytochemical screening via colorimetric method and the quantitative estimation of phenolic and flavonoid content were performed. Antioxidant assay using DPPH scavenging method was studied. Antimicrobial screening of plant extracts was done by cup diffusion technique. Cytotoxic activity of B. diffusa was studied by brine shrimp bioassay and anthelminthic activity was evaluated in vitro in Pheretima posthuma. This study revealed B. diffusa as a source of various phyto-constituents such as alkaloids, glycosides, saponins, tannins, carbohydrates, cardiac glycosides, flavonoids and terpenoids. Quantitative estimation of total phenol was found to be maximum in BEE i.e. $29.73{\pm}0.88$, BME $19.8{\pm}2.02$ and in BHE $9.15{\pm}0.304mgGAE/g$. Similarly, the total flavonoid content was found to be $17.44{\pm}0.75$ in BEE, $14.43{\pm}0.23$ in BHE and 3.678 mg QE/g in BME. Ethyl acetate extract showed its antibacterial activity against all tested pathogens except Escherichia coli whereas Staphylococcus aureus and Salmonella Typhi were resistant to methanol and hexane extract. The zone of inhibition (ZOI) of ethyl acetate extract against S. Typhi and B. cereus was found to be 18 mm and 14 mm respectively. The MIC value of BEE in S. Typhi was $3.125{\mu}g/ml$ and in B. cereus was $12.5{\mu}g/ml$. The preliminary screening of anticancer property of B. diffusa i.e. BSLT in methanol was found to be $165.19{\mu}g/ml$. B. diffusa was also found to contain anthelmintic property. The study helped in further exploration of medicinal properties of B. diffusa by phytochemical screening and biological activities paving the path for study and investigation in this plant.

• Journal of Information Processing Systems
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• 제12권1호
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• pp.46-56
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• 2016

Dynamic textures are videos that exhibit a stationary property with respect to time (i.e., they have patterns that repeat themselves over a large number of frames). These patterns can easily be tracked by a linear dynamic system. In this paper, a model that identifies the underlying linear dynamic system using wavelet coefficients, rather than a raw sequence, is proposed. Content based threshold filtering based on Set Partitioning in a Hierarchical Tree (SPIHT) helps to get another representation of the same frames that only have low frequency components. The main idea of this paper is to apply SPIHT based threshold filtering on different bands of wavelet transform so as to have more significant information in fewer parameters for singular value decomposition (SVD). In this case, more flexibility is given for the component selection, as SVD is independently applied to the different bands of frames of a dynamic texture. To minimize the time complexity, the proposed model is implemented on a graphics processing unit (GPU). Test results show that the proposed dynamic system, along with a discrete wavelet and SPIHT, achieve a highly compact model with better visual quality, than the available LDS, Fourier descriptor model, and higher-order SVD (HOSVD).

• 한국정보기술학회논문지
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• 제16권11호
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• pp.43-49
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• 2018

MCP 세척용 전자총을 개발하기 위하여 SIMION 프로그램을 이용하여 컴퓨터 시뮬레이션하였다. 표적인 MCP는 전자총의 전자방출원으로부터 180mm에 위치해 있고, MCP의 직경은 약 20mm이고, E, ${\phi}$, d1, d2 등 4개의 변수를 이용하여, MCP에 도달하는 전자의 빔직경이 20mm가 되는 조건을 찾았다. 여기서 E는 MCP에 도달하는 전자의 에너지, ${\phi}$는 익스트랙터의 직경, d1과 d2는 각각 전자방출원에서 익스트랙터 관 끝까지의 거리, 전자방출원에서 쳄버 벽까지의 거리이다. 컴퓨터 시뮬레이션한 결과, E와 d2는 빔직경에 거의 영향을 주지 않음을 확인하였다. 반면에 빔직경은 d1에 따라서는 매우 민감하게 변하고, ${\phi}$에 따라서도 다소 크게 변함을 알 수 있었고, d1은 ${\phi}$와 2차함수의 관계가 있음을 알아내었다. 이 함수를 이용하여 본 연구의 목적에 적합한 전자총을 설계할 수 있음을 확인하였다.