• Journal of the Korean Vacuum Society
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• v.17 no.1
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• pp.9-15
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• 2008

Various diatomic inorganic films and their composite films are packed as passivation films covering Ca cells on glass substrates by using an electron-beam evaporation technique. When these Ca cells are exposed to an ambient atmosphere, the water vapor penetrating through the passivation layers is absorbed in the Ca cells, resulting in a gradual progress of transparency in the Ca cells, which can be represented by changes of the optical transmittance in the visible range. Compared with the saturation times for the Ca cells to become completely transparent in the atmosphere, the protection effects of water vapor are estimated for various passivation films. The composite films consisting silicon oxide($SiO_2$) and tin oxide($SnO_2$) or zinc oxide(ZnO) are found to show a superior protection effect of water vapor as compared with diatomic inorganic films. Also, the main factors affecting the permeation of water vapor through the oxide films are found to be the polarizability and the packing density.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.24 no.12A
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• pp.1922-1931
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• 1999

A multicast traffic’s feature is the function of providing a point to multipoints cell transmission, which is emerging from the main function of ATM switch. However, when a conventional point-to-point switch executes a multicast function, the excess load is occurred because unicast cell as well as multicast cell passed the copy network. Additionally, due to the excess load, multicast cells collide with other cells in a switch. Thus a deadlock that losses cells raises, extremely diminishes the performance of switch. An input queued switch also has a defect of the HOL (Head of Line) blocking that less lessens the performance of the switch. In the proposed multicast switch, we use shared memory switch to reduce HOL blocking and deadlock. In order to decrease switch’s complexity and cell's processing time, to improve a throughput, we utilize the method that routes a cell on a separated paths by traffic pattern and the scheduling algorithm that processes a maximum 2N cell at once in the control part. Besides, when cells is congested at an output port, a cell loss probability increases. Thus we use the Output Memory (OM) to reduce the cell loss probability. And we make use of the method that stores the assigned memory (UM, MM) with a cell by a traffic pattern and clears the cell of the Output memory after a fixed saving time to improve the memory utilization rate. The performance of the proposed switch is executed and compared with the conventional policy under the burst traffic condition through both the analysis based on Markov chain and simulation.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.32 no.2D
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• pp.121-127
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• 2012

One of the traffic problems has been caused by the illegal parking because of the lack of parking space. Especially, the illegal occupancy of the road near an intersection makes an serious reduction of road capacity. The current illegal parking and stop-prohibited areas have been designated for less than 5 meters from the edge or the corner of the 4-leg intersection. However, in reality, the cars parked at the place over 5 meters have had a significant impact on the intersection traffic. In addition, many variables such as intersection type, size, and service levels should be considered as factors which influence on the traffic condition at the intersection. It was assumed that through and right-turn traffic rate have a significant impact on the 4-leg intersection with the illegal parking or stop near it. This study tried to verify the impact through the simulation implementation with MOE and LOS. It shows a guideline to designate the parking or stop-prohibited area near the 4-leg intersection under various traffic conditions.

• Journal of Embryo Transfer
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• v.18 no.2
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• pp.151-156
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• 2003

The objective of this study was to investigate response of corpus luteum, recovery rate of embryos and production of transferable embryos according to superovulation by PEG 30% FSH in Hanwoo. Cows were selected as recipient, subsequent were superovulated with a total of 400 mg NIH-FSH-P1(Folltropin-V, Canada) given by one shot subcutaneously. At the time of five days after Folltropin injection, 25mg of a PGF$_2$a was injected and cows were inseminated 12 and 24h after the onset of estrus. Seven days after insemination, embryos were collected non-surgically and were cryopreserved by direct transfer methods. The results are summarized as follows : 1. Response of corpus luteum following the superovulation in Hanwoo, right ovary were 52.8%(271/513) and left ovary were 47.1%(242/513), respectively (P<0.05). 2. Recovery rate of embryos following the number of corpus luteum were 83.0%(426/513). 3. Mean number of embryos recovered and transferable embryos were 7.74 and 6.43, respectively (P<0.05). 4. In the total number of transferable embryos per flush were collected 6.4 and all saved transferable embryos were 355.

• Journal of the Korean Wood Science and Technology
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• v.35 no.6
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• pp.91-99
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• 2007

Activities of the extracellular enzyme from Fomitopsis palustris, a brown-rot fungi, and by which crystallinity changes of cellulose in the various softwoods, such as Larix leptolepsis, Finns rigida, Finns koraiensis and Finns densiflora by liquid culture, were investigated. Activity of Cellobiohydrolase (CBH) from F. palustris was detected in the every test softwoods culture, showing activities of the Endoglucanase (EG), $\beta$-glucosidase (BGL) and $\beta$-1,4-xylosidase (BXL). It was shown high enzyme activities in the sapwood culture than heartwood of the same wood species, However, the enzyme activities in most of test wood cultures increased with longer incubation time, indicating a possibility of intermix sapwood and heartwood for degradation process by enzyme. Also it was shown that protein patterns of the extracellular enzyme from F. palustris in wood particle substrate of the several domestic softwoods were similar with each other wood species, which suggested the possibility of mixing all softwoods in saccharification by enzyme from F. palustris. Crystallinity reduction value of cellulose by F. palustris was 4.2~20.4% in 4 weeks cultivation, 12.9~28.9% in 8 weeks.

• 한국신재생에너지학회:학술대회논문집
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• 2011.11a
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• pp.49.1-49.1
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• 2011

집광채광 설비는 건축물의 조명에너지 절감 및 자연광의 실내 유입을 위해 적용 가능한 태양에너지설비로써 다른 신 재생 에너지 설비와 다르게 연간에너지생산에 대한 정량적 데이터가 아직까지 부재하다. 집광채광 설비의 설치효과를 판단하기 위해서는 집광채광 설비 설치에 따른 연간 에너지생산량 산출이 필요하며, 이를 위해서는 각 구성부분(집광부, 전송부 및 산광부)의 광전송 효율에 대한 데이터가 구축되어야 한다. 본 연구는 집광채광 설비의 효율 분석에 관한 첫 번째 단계로써 외부광속에 대한 집광부 통과 직후의 내부광속의 비율을 예측하였다. 국내에 보급된 집광채광 설비는 대부분 프리즘형과 광덕트형이며, 우선적으로 집광부 입사면의 경사각과 방위각이 다양하여 내부광속 산출방법론이 매우 복잡한 프리즘형을 분석대상으로 삼았다. 전일사량, 외부조도 및 집광부 내부조도가 측정되었으며, 외부광속으로부터 내부광속을 산출하는 공식을 유도하기 위해 천공상태에 따라 전일사량 측정치가 직산분리 되었다. Perez model과 Liu and Jordon에 의해 제시된 계산식과 입사면 및 집광부 면적을 고려하여 수평면 외부조도 측정치로부터 외부광속이 그리고 내부조도로부터 내부광속이 산출되었다. 입사면의 투과율이 동일하다는 전제 하에 천공상태에 따른 태양광 투과 비율을 도출한 결과, 담천공(Kt ${\leq}$ 0.3)에서 0.39, 부분담천공(0.3${\geq}$ 0.78)에서 1.0으로 나타났다. 도출된 투과비율을 외부광속에 적용하여 내부광속을 계산한 결과치와 측정치는 약 ${\pm}9%$ 정도의 차이를 보였다. 연간 기상데이터에 위와 같은 방법론이 적용되면 프리즘형 집광부의 연간 내부광속이 산출될 수 있다. 또한 기존 연구에서 제시된 발광효율 산출식과 일사 파장에 따른 시감도를 고려하면 매 시간별 외부조도도 산출이 가능하다. 일사량 측정치와 외부조도 측정치 사이의 상관관계를 분석한 결과 결정계수 $R^2$이 0.99인데 반해 일사량 측정치와 외부조도 계산치 사이의 상관관계 결정계수는 0.95로 측정치 보다 약간 작은 값을 갖는다. 이렇게 산출된 외부조도는 각 입사면의 면적을 반영하여 외부광속으로 변환되고, 앞서 산출된 천공상태별 투과비율이 적용됨으로써 내부광속이 도출될 수 있다. 이와 같은 집광부에 대한 연구를 바탕으로 향후 전송부와 산광부 효율을 도출하고 궁극적으로 집광채광 설비를 통해 실내에 전달되는 연간 빛에너지를 예측할 수 있을 것이다. 또한 본 연구의 방법론은 다른 형태의 집광채광 설비에도 적용이 가능할 것으로 판단되며, 국내 집광채광 설비의 연간 에너지생산량에 대한 폭 넓은 데이터 구축이 가능할 것으로 기대된다.

• Analytical Science and Technology
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• v.15 no.3
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• pp.263-269
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• 2002

After porous filters were manufactured using cordierite powder whose mean particle size was 200 ${\mu}m$, they were loaded with catalysts such as Pt, Pd, Cu, Co, La, $V_2O_5$ by vacuum impregnation method. And we investigated the activity of catalysts used for catalytic oxidation of VOC by passing toluene through catalyst-loaded filters. The porous filters had the apparent porosity of 62%, the compressive strength of about 10 MPa and the pressure drop of 15 mmHg at the face velocity of 5 cm/sec. The loading of catalyst decreased the porosity of the filters and increased the pressure drop and the compressive strength of them. Among the catalysts, Pt had the highest activity for catalytic oxidation and could remove more than 90% of toluene at 250 $^{\circ}C$. Below 250 $^{\circ}C$, the content of Pt catalyst had an influence on the conversion of toluene but didn't show any influence above 250 $^{\circ}C$.

• Journal of Biomedical Engineering Research
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• v.25 no.5
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• pp.343-349
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• 2004

Electroglottograph(EGG) is a signal recorded from the vocal cord vibration by measuring electrical impedance across the vocal folds through the neck skin. The purpose of this study was to develop EGG system and to evaluate possibility for the application on speech analysis and laryngeal disease diagnosis. EGG system was composed of two pairs of ring electrodes, tuned amplifier, phase sensitive detector, low pass filter, and auto-gain controller. It was designed to extract electric impedance after detecting by amplitude modulation method with 2.7MHz carrier signal. Extracted signals were transmitted through line-in of PC sound card, sampled and quantized. Closed Quotient(CQ), Speed Quotient(SQ), Speed Index(SI), fundamental frequency of vocal cord vibration(F0), pitch variability of vocal fold vibration (Jitter), and peak-to-peak amplitude variability of vocal fold vibration(Shimmer) were analyzed as EGG parameters. Experimental results were as follows: the faster vocal fold vibration, the higher values in CQ parameter and the lower values in SQ and SI parameters. EGG and speech signals had the same fundamental frequency. CQ, SQ, and SI were significantly different between normal subjects and patients with laryngeal cancer. These results suggest that it is possible to implement portable EGG system to monitor the function of vocal cord and to test functional changes of the glottis.

• Journal of Biomedical Engineering Research
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• v.23 no.1
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• pp.61-72
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• 2002

In this parer, a new harmonic imaging technique is Proposed and evaluated experimentally. In the Proposed method. a weighted chirp signal with a hanning window is transmitted. The RF samples obtained on each array element are individually compressed by correlating with the reference signal defined as the 2nd harmonic component($2f_0$) of a transmitted chirp signal generated in a square-law system. The correlator output will then consist of the compressed version of the $2f_0$ component generated in tissue and the crosscorrelation sequence of the fundamental($f_0$) and 2f$_{0}$components. The Proposed method uses the compressed $2f_0$ component to form an image. for which the crosscorrelation term should be suppressed below at least -50dB. The Proposed method has two process, 2f$_{0}$-correlation and $2f_0$-correlation(PI) . $2f_0$-correlation can successfully eliminate the $f_0$ component with a single transmit-receive events and therefore is more efficient than the conventional Pulse inversion method in terms of the frame rate. 2i)-correlation(Pl) Performs pulse compression after applying pulse inversion method for the 2nd harmonic image with high resolution and SNR. Another advantage of the proposed method is that the SNR of 2nd harmonic imaging can be improved without limitation by increasing the duration of the chirp signal. The proposed method was verified through both the computer simulations and actual experiments .ts .

• Fire Science and Engineering
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• v.32 no.5
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• pp.46-51
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• 2018

The purpose of this study was to assess the evacuation route in a disaster information map to evacuate people to a shelter quickly and precisely during a disaster situation. For this purpose, this study examined the current status of domestic and international disaster information maps and related laws and conducted experiments to derive effective types of intersecting routes. The problems of the disaster information map were obtained through the first preliminary experiment and a survey. Based on these problems, experiments for each type were conducted to provide effective indication information for a disaster information map. To investigate the gait characteristics according to the number of crossing paths, the reduction rate in the crossing path was derived for each type by comparing the previous speed and passing speed. This will enable suggestions to judge the route quickly and accurately when determining the intersecting route in the search for an evacuation route. In conclusion, the experiment of this paper aims to make rapid and accurate evacuations using the disaster information map in response to disasters, and provide guidelines to citizens to contribute to a reduction of casualties.