• Earthquakes and Structures
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• 제2권4호
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• pp.337-356
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• 2011

In this paper, cable-stayed bridges with single pylon and two equal side spans, with variations in geometry and span ranging from 120 m to 240 m have been studied. 3D models of the bridges considered in this study have been analysed using ANSYS. As the first step towards a detailed seismic analysis, free vibration response of different geometries is studied for their mode shapes and frequencies. Typical pattern of free vibration responses in different frequencies with change in geometry is observed. Further, three different seismic loading histories are chosen with various characteristics to find the structural response of different geometries under seismic loading. Effect of variation in pylon shape, cable arrangement with variation in span is found to have typical characteristics with different structural response under seismic loading. From the study, it is observed that the structural response is very much dependent on the geometry of the cable-stayed bridge and the characteristics of the seismic loading as well. Further, structural responses obtained from the study would help the design engineers to take decisions on geometric shapes of the bridges to be constructed in seismic prone zones.

• The Journal of the Acoustical Society of Korea
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• 제16권2E호
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• pp.47-54
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• 1997

This paper presents two results on intersymbol interferences in baseband digital communication over an additive white Gaussian noise channel-the interferences due to mismatched square-root raised-cosine filters, in which the filters have different roll-off factors, and / or due to sampling-time jitter. The result for the mismatched filters is that even the jitter-free sampling causes intersymbol interference and it is negligibly small for a wide range of signal-to-noise ratio up to 10dB, for the roll-off factor ranging from 0.2 to 0.5, the mismatch loss being within 0.1dB from the optimum at around 10-6 .For jitter interference an approximation formula for the bit error probability is derived in case of the matched filters, which shows how the roll-off factors and the amount of jitter affect the system performance. The formula is reasonably accurate.

• 한국식품조리과학회지
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• 제25권4호
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• pp.496-505
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• 2009

The influence of roasting time on antibacterial and antioxidative effects of methanol and water coffee extracts was investigated. Extract yield differed with roasting time. The maximum yield of methanol extract was 20.02% and 24.00% at respective roasting times of 12 and 20 min. The maximum yield of water extracts was 2.70% and 18.58% at 5 and 25 min roasting time, respectively. Antibacterial effects of each extract were determined by the classical minimal inhibitory concentration (MIC) paper disc diffusion method. Methanol extracts of different coffee samples inhibited growth of various strains except Escherichia coli. Extracts obtained following roasting times of 12, 14, 16, 20, and 25 min in particular displayed the most potent activity against Staphylococcus aureus. Among these extracts, that obtained from 12 min roasted coffee samples produced a MIC of $16.125{\mu}g$/mL against S. aureus. Water extracts applied at $1,000{\mu}g$/mL were growth inhibitory except against Salmonella choleraesuis and Prevotella intermedia. However, growth inhibition by water extracts was weak, with inhibitory zones of only 6-8 mm diameter produced. Determinations of free radical elimination for the different coffee extracts using 1,1-diphenyl-2-picrylhydrazyl were compared with ascorbic acid and butylated hydroxytoluene positive controls. Methanol and water extracts of different coffee samples ($100{\mu}g$/mL) showed $67.1{\sim}92.3%$ and $66.4{\sim}93.3%$ radical scavenging activity, respectively. However, longer roasting time (especially >20 min) tended to somewhat lower free radical elimination using both extracts. Total phenol in different coffee samples measured by the Folin-Denis method revealed the highest level of phenol contents with non-roasted coffee, whereas phenol content differed with different roasting time, ranging from $87.{\sim}126.5\;mg/g$ in methanol extracts. In water extracts, the phenol content was maximum at 8 min roasting time, whereas in other samples the content was varied from $95.0{\sim}199.1\;mg/g$.

• Journal of Animal Science and Technology
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• 제45권4호
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• pp.649-658
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• 2003

오리농법에 있어서 논 방사 직후의 새끼오리는 물을 포함한 논 환경에 충분히 적응하지 못하고 폐사하거나 사람에 대한 도피행동에 의해 벼를 밟아 넘어뜨리는 등의 피해가 발생하고 있다. 또한 방사종료 후 오리포획에 있어서도 많은 시간과 노력이 소요되고 있다. 본 시험에서는 이와 같은 문제를 오리 육추시 특정의 사육관리를 통한 행동학적 측면에서 해결하고자, 논 방사할 오리에 대해 각인학습과 길들이기 등 온순한 관리를 행한 순치구, 거칠고 난폭하게 관리하면서 공포심을 부여한 조폭구 및 각인학습이나 길들이기, 공포심 등 사람과의 접촉경험이 거의 없는 대조구의 3 처리구로 구분하고, 오리의 행동유형, 성장 및 벼 수량성에 대하여 검토하였다. 오리의 행동유형에 있어서 논 방사직후의 채식과 이동행동은 조폭구 및 대조구에 비해 순치구에서 가장 많았고, 방사 2주 후의 채식과 이동행동에서는 순치구 및 조폭구보다 대조구에서 증가하는 경향을 나타내었다. 사람에 대한 도피반응거리에 있어서는 순치구에서 전혀 도피반응을 보이지 않았고, 조폭구보다 대조구에서 유의적으로 길게 나타났다. 오리 포획시간은 순치구에서 가장 짧았고, 다음으로 대조구, 조폭구의 순으로 나타났으며, 오리 순치방법에 따른 증체량에서는 처리구간에 큰 차이가 없었다. 벼 결주발생율은 대조구에 비해 순치구에서 유의적으로 적었고, 수량성에 대해서는 처리구간에 유의적인 차이는 인정되지 않았다. 이상의 시험결과를 종합해 볼 때, 오리 육추시 및 논 방사시의 각인학습과 온순한 관리는 벼의 결주 발생을 경감시키고, 오리가 사람에게 쉽게 순화되어 포획하는데 소요되는 시간과 노력이 현저하게 감소되는 것을 알 수 있었다. 그러나 논에서 오리의 노동행동과 벼 수량성에는 큰 영향을 미치지 않는 것으로 나타났다.

• Archives of Reconstructive Microsurgery
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• 제2권1호
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• pp.70-76
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• 1993

The authors analyzed the clinical results of the reconstructive surgery for injured hands and feet due to frostbites and electrical burn with microsurgery in 7 patients, 12 cases at the department of orthopaedic surgery, school of medicine, Kyung Hee university from Jan. 1989 to Jul. 1992, and the results were as foollowings. 1. The age at the time of injury was av 24.6 yrs ranging from 4 to 35 yrs, and all cases were male. 2. The follow up period was av. 24.4 Mo ranging from 12 Mo. to 56 Mo. 3. The causes of injury were frostbite in 9 cases, electrical burn in 2 cases. 4. Initial operative treatment was performed av. 69.3 days ranging from 2 to 210 days. 5. For the reconstructive procedure, scapular free flap was applied in 6 cases, radial forearm flap in 4, dorsalis pedis 1ffap in 1, neurovascular island flap in 1. 6. Among total 12 cases, there were 5 cases(41.7%) of wound infection and 3 cases (25.0%) of partial necrosis of donor flap. 7. In 11 cases(90.1%), the end result was satisfactory. In the analysis of above results the reconstruction with microsurgery is effective procedure for reconstruction of Injured hand and foot due to frostbite and electrical burn.

• 한국통신학회논문지
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• 제31권10C호
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• pp.921-926
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• 2006

초광대역(UWB) 시스템은 높은 시간분해능으로 인해 복잡한 다중경로 환경에서도 정밀한 위치추적을 가능하게 한다. 그러나 송수신 채널에 존재할 수 있는 장애물로 인해서 정밀한 위치추적 성능이 저하될 수 있다. 첫째로 장애물은 다중경로의 구조를 복잡하게 만들어 직선경로 신호 성분의 도착시간 추정을 어렵게 만든다. 둘째로 전파시간에 초과시간지연을 초래하여 거리추정의 정확도를 저하시킬 수 있다. 본 논문에서는 광선추적법을 사용하여 두번째 원인에 의해 발생하는 거리추정 오차를 줄이는 기법을 소개한다. 이를 위하여 통계적인 접근방식과 지도를 이용한 위치인식기법을 사용하였다. 통계적인 접근방식에서는 매질에 의해서 발생하는 초과시간지연들의 분포를 광선추적법을 사용하여 구하고, 이에 근거하여 오차의 하계를 구하였다. 또한 건물의 도면을 이용한 위치인식 방법에도 광선추적 법을 사용하였으며, 그 성능을 사무실 환경에서 측정된 데이터를 사용하여 검증하였다.

• The Plant Pathology Journal
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• 제35권2호
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• pp.164-171
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• 2019

An assay for detecting Apple scar skin viroid (ASSVd) was developed based on nucleic acid sequence based amplification (NASBA) in combination with realtime detection during the amplification process using molecular beacon. The ASSVd specific primers for amplification of the viroid RNA and molecular beacon for detecting the viroid were designed based on highly conserved regions of several ASSVd sequences including Korean isolate. The assay had a detection range of $1{\times}10^4$ to $1{\times}10^{12}$ ASSVd RNA $copies/{\mu}l$ with reproducibility and precision. Following the construction of standard curves based on time to positive (TTP) value for the serial dilutions ranging from $1{\times}10^7$ to $1{\times}10^{12}$ copies of the recombinant plasmid, a standard regression line was constructed by plotting the TTP values versus the logarithm of the starting ASSVd RNA copy number of 10-fold dilutions each. Compared to the established RT-PCR methods, our method was more sensitive for detecting ASSVd. The real-time quantitative NASBA method will be fast, sensitive, and reliable for routine diagnosis and selection of viroid-free stock materials. Furthermore, real-time quantitative NASBA may be especially useful for detecting low levels in apple trees with early viroid-infection stage and for monitoring the influence on tree growth.

• Environmental Sciences Bulletin of The Korean Environmental Sciences Society
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• 제10권S_1호
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• pp.23-28
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• 2001

A new numerical weather prediction and dispersion model, the Operational Multi-scale Environment model with Grid Adaptivity(OMEGA) including an embedded Atmospheric Dispersion Model(ADM), is introduced as a next generation atmospheric simulation system for real-time hazard predictions, such as severe weather or the transport of hazardous release. OMEGA is based on an unstructured grid that can facilitate a continuously varying horizontal grid resolution ranging from 100 km down to 1 km and a vertical resolution from 20 -30 meters in the boundary layer to 1 km in the free atmosphere. OMEGA is also naturally scale spanning and time. In particular, the unstructured grid cells in the horizontal dimension can increase the local resolution to better capture the topography or important physical features of the atmospheric circulation and cloud dynamics. This means the OMEGA can readily adapt its grid to a stationary surface, terrain features, or dynamic features in an evolving weather pattern. While adaptive numerical techniques have yet to be extensively applied in atmospheric models, the OMEGA model is the first to exploit the adaptive nature of an unstructured gridding technique for atmospheric simulation and real-time hazard prediction. The purpose of this paper is to provide a detailed description of the OMEGA model, the OMEGA system, and a detailed comparison of OMEGA forecast results with observed data.

• 열처리공학회지
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• 제9권1호
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• pp.27-33
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• 1996

Metallographic observation was carried out by scanning and transmission electron microscopy to evaluate microstructural characteristics of partially austenitized and isothermally transformed 1.0C-1.5Cr bearing steel. It was observed that lower bainite formed in the local region of specimen partially austenitized and isothermally held at $250^{\circ}C$ for 1/3 hr and formed in almost all area of the specimen isothermally held at $250^{\circ}C$ for 2 hrs. Lower bainitic carbides with midrib was also observed in the specimen partially austenitized and isothermally held at $250^{\circ}C$ for 4 hrs. Midrib was nearly carbide-free region and thicker in the vicinity of spherical carbides than the other region. Lengthening speed of lower bainitic carbides was remarkabey increased at isothermal holding time ranging from 2 hrs to 4 hrs.

• 한국정보통신학회논문지
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• 제15권6호
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• pp.1289-1300
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• 2011

최근 고성능 컴퓨터에서 메모리 사용량이 매우 큰 프로그램과 파일 접근을 많이 하는 프로그램을 동시에 실행하고 있다. 많은 메모리의 사용은 디스크의 스왑 공간에 대해 디스크 접근을 빈번히 발생시키고, 파일 접근은 디스크의 파일 시스템 파티션으로 디스크 접근을 야기한다. 이런 두 종류의 프로그램을 동시에 실행하면 스왑 공간과 파일 시스템 파티션 간에 디스크 탐색이 빈번히 발생할 수 있다. 이런 문제를 해결하기 위해 본 논문은 SAF 기법을 제안한다. 이 기법은 파일 시스템 파티션에 새롭게 여러 개의 스왑 공간을 배치하고, 이들 공간에 페이지-아웃되는 페이지들을 저장한다. 즉, 페이지들은 가장 최근에 접근한 파일의 디스크 위치에 근접한 스왑 공간에 저장된다. 이 스왑 공간이 기존의 스왑 공간에 비해 최근 접근된 파일의 위치로부터 가까운 거리에 있기 때문에 파일 접근 후 발생하는 디스크 탐색의 시간을 크게 줄일 수 있다. 성능 검증을 위해 BSD기반의 FreeBSD 6.2 운영체제에 SAF를 구현하였고, 5개의 벤치마크를 실행하여 성능을 측정하였다. 성능 측정 결과 SAF는 FreeBSD에 비해 벤치마크의 실행 시간을 약 14%∼42% 감소시켰다.