• 대한예방의학회:학술대회논문집
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• 2002.10a
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• pp.461-462
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• 2002

• Communications for Statistical Applications and Methods
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• v.10 no.3
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• pp.795-804
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• 2003

In this article, a tomography for the estimation of the origin-destination(OD) traffic intensities in dynamic routing network is considered. Vardi(1996)'s approach based on fixed route is not directly applicable to dynamic routing protocols, which arises from the fact that we cannot access the route at every observation time. While it uses link-wise traffics as the observations, the proposed method considers the triple of ingress/outgress/relayed traffics data at each node so that we can transform the problem into a routing-independent tomography. An EM algorithm for implementation and some simulated experiments are provided.

• Proceedings of the Korea Information Processing Society Conference
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• 2005.05a
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• pp.599-602
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• 2005

본 논문에서는 운영 레거시 시스템으로부터 엔드 유저에까지 실시간으로 데이터를 전달하는 전체적인 프로세스를 정의한 ODS 레이어를 제시한다. ODS 의 레이어를 위하여 먼저 데이터 소스가 정의된다. 그 다음 데이터 소스로부터 ODS까지 데이터를 수집하는 방법이 정의된다. 마지막으로 엔드 유저 집단을 위한 ODS로의 데이터 접근을 준비한다. 운영 시스템과 ODS 간의 통합 레벨에 따른 ODS의 타입을 분류하고 특성을 요약한다.

• Proceedings of the Korea Contents Association Conference
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• 2013.05a
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• pp.261-262
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• 2013

본 논문에서는, 구조 상태모델로 시스템의 고장과 복구를 나타내는 상위계층 모델과, 주어진 구조 상태애서 해당시스템의 처리과정인 도착, 큐잉, 서비스를 나타내는 하위계층모델을 갖는 다중 프로세서 컴퓨터 시스템의 계층모델을 페트리 네트의 확장형인 SRN을 이용하여 개발한다. 컴퓨터 가용도의 한 지표로써 NTL(Normalized Throughput Loss)를 구한다.

• Transportation Technology and Policy
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• v.2 no.4
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• pp.71-77
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• 2005

• Journal of the Korea Academia-Industrial cooperation Society
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• v.14 no.7
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• pp.3191-3196
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• 2013

Ultrasonic transducer is the sensor which is measuring distance. Piezo ceramic of ultrasonic sensor and adhesive technique of matching layer are the most core techniques. With the study of relation on matching layer which takes off the ultrasonic wave into the air, this paper aims to find the second useful frequency as the results which can be changed are extracted in case piezo ceramic and matching layer are bonded. And the experiment is done with piezo ceramic as real piezoelectric element and matching layer of chemical wood. OD of piezo ceramic has designed by ${\Phi}50{\times}3T$ and OD of matching layer is designed by ${\Phi}62{\times}12t$ with ${\lambda}=1/4$. Acoustic impedance is generated at the most optimum resonant frequency of 53 Khz. As experimental result, more available frequency can be generated by using the adhesive close to solid than the flexible one.

• Microbiology and Biotechnology Letters
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• v.43 no.3
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• pp.187-194
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• 2015

In this study, L. plantarum, when reacting with the culture media of potential pathogenic bacteria, exhibited an increase in growth rate and antimicrobial activity. In order to examine the characteristics and the nature of the reaction with the bacteria, this study carried out experiments involving culturing the test bacteria in M9 minimal media. Subsequently, the supernatant was incrassated by the decompression-drying method. Through colony forming unit assay, it was confirmed that L. plantarum had the function of growth inhibition to various bacteria. After culturing L. plantarum with bacterial media, the growth rate of L. plantarum was measured by absorbance (OD₆₀₀), the results showed that the growth rate (E. coli treatment group: OD₆₀₀ = 0.848, S. typhimurium treatment group: OD₆₀₀ = 0.848) increased, as compared with the non-treated control group (OD₆₀₀ = 0.48). In contrast, the concentrate itself did not induce the growth of L. plantarum. These results were observed as a universal phenomenon of the Lactobacillus species. Moreover, the increase in antimicrobial activity was observed in L. plantarum, which reacted with the culture media of E. coli and S. typhimurium, through a disc diffusion assay, and the result of growth inhibition against various bacteria was induced. Finally, based on the analysis results of the characteristics of bacteria culture media, which increased the growth rate of L. plantarum and antibacterial activity, the bacterial media had a tolerance for catabolic enzymes, pH 2−8 and heat. Therefore, this substance can be said to be a small molecule which is highly stable under various conditions.

• Korean Journal of Microbiology
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• v.30 no.2
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• pp.78-82
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• 1992

The dikaryon of Trimorphonzycc,.~ papilioncicc.ous, one of basidiornycetous yeast needed thiamine as a growth factor and required relatively simple nutrient components. This organism grem best at 25$^{\circ}$C. anci showed broad pH range (pH 4.0-7.0). It was groM,n in liquid minimal media with various carbon sources and they could be classilied into 3 groups as follows. Glucose. fructose. mannose, sucrose and xylose (A gi.oup) supportecl good growth (>OD 0.8), and showed poor laccase activity (less than 1.5 u'mg protein). Galactose and gluconate (B group) showed moderate growth (01) 0.3-0.6). and hail moderatc crlzyrne activity (4-6u). Arabinosc. lactose. maltose ant1 pyruvate (C 5roup) showed poor growth (OD 0.1-0.2). and showed high enzyme activity (higher than 8 u). Kibosc, acetate. citrate. lactate and oxaloacetate showed no growth. When the yeast was grown in a medium which had two carbon sources (glucose and arabinose). laccase was regul;~tecl by the cutahoiitc repression.

• Journal of the Korea Organic Resources Recycling Association
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• v.15 no.2
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• pp.128-135
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• 2007

Microorganisms which can degrade organic compounds such as proteins, lipids, and cellulose in food wastewater, were isolated from food wastewater, livestock wastewater, earthworm, and etc. Among these, eleven strains which showed higher degrading activities against three organic compounds, were finally isolated, characterized, and identified. Nine strains were found to be Bacillus species, and other two were to be Enterobacter sp. and Pantoea agglomerans. The strains FWB-5 (Bacillus pumilus), FWB-6 (B. lichenisformis) and OD-4 (Pantoea agglomerans), isolated from food wastewater and livestock wastewater, respectively, showed higher three enzyme activities to organic compounds, especially to cellulose, compared to other strains. The optimal growth conditions for the great enzyme activities were at $37^{\circ}C$ with pH 7.0 for FWB-5 and OD-4 strains, whereas, these were at $25^{\circ}C$ with pH 7.0 for FWB-6 strain.

• Journal of Electrical Engineering and Technology
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• v.11 no.1
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• pp.86-92
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• 2016

Upon detecting a frequency event in a power system, the stepwise inertial control (SIC) of a wind turbine generator (WTG) instantly increases the power output for a preset period so as to arrest the frequency drop. Afterwards, SIC rapidly reduces the WTG output to avert over-deceleration (OD). However, such a rapid output reduction may act as a power deficit in the power system, and thereby cause a second frequency dip. In this paper, a hybrid reference function for the stable SIC of a doubly-fed induction generator is proposed to prevent OD while improving the frequency nadir (FN). To achieve this objective, a reference function is separately defined prior to and after the FN. In order to improve the FN when an event is detected, the reference is instantly increased by a constant and then maintained until the FN. This constant is determined by considering the power margin and available kinetic energy. To prevent OD, the reference decays with the rotor speed after the FN. The performance of the proposed scheme was validated under various wind speed conditions and wind power penetration levels using an EMTP-RV simulator. The results clearly demonstrate that the scheme successfully prevents OD while improving the FN at different wind conditions and wind power penetration levels. Furthermore, the scheme is adaptive to the size of a frequency event.