• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 1999.11a
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• pp.260-265
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• 1999

멀티빔 음향측심기(Multibeam Echo Sounder)는 기존의 단빔 음향측심기(Singlebeam Echo Sounder)와 달리 탐사선 진행방향의 수직(Crosstrack)으로 해저면을 주사(Swath)하여, 한 번의 송수신(Ping)으로 다중의 빔 자료 - 수심, 후방산란된 음압(Backscattered Amplitude), 사이드 스캔 소나(Side Scan Sonar) 자료 - 를 취득하는 장비이다. 멀티빔 음향 측심기를 이용한 해저면 탐사의 경우, 수심이 변함에 따라 주사폭(Swath width)이 변화하고, 각 빔의 수평 해상도(Footprint)는 수심과 더불어 빔폭(Beam width)에 의하여 동적으로 변화한다. 멀티빔 음향 측심기는 해저면을 전역탐사 할 수 있을 뿐만 아니라, 연속된 음향 탐사를 통하여 이웃한 핑 사이에 발생하는 전방중첩영역(Endlap)과 이웃 측선(Trackline)을 따라 겹쳐지는 측방중첩영역(Sidelap)의 자료들을 이용하여 멀티 뎀 자료들의 전반적인 정확도 및 신뢰도를 평가할 수 있다. 본 논문은 수로 측량(Hydrographic Survey)에서 사용되는 멀티빔 음향 측심기를 운영하여 얻어진 측심 자료를 처리하는 알고리즘 개발에 관한 연구이다. 본 논문에서는 L3사의 Sea Beam 2100 벌티빔 음향 측심기를 대상으로, 멀티빔의 측심 원리와 해저 지형에 대한 일반적 이해를 통하여 획득된 측심 자료의 통계적 특성을 파악하고, 오측심된 수심 자료를 제거하는 방법을 제안하며, 측심 구간의 대표격자 크기를 결정하는 기준을 제시한다. 또한, 항공원격탐사에서 고도 추정시 사용되고 있는, 평균보간법, 가중평균 보간법과, 본 논문에서 제안하는 격자 대표값 선정 알고리즘(Gridding Algorithms)의 결과를 비교하고, 최종적으로 얻어지는 해저 수치지형모델(DEM, Digital Elevation Model)과 후방산란 영상을 제시한다. 빠른 한지형잔디들이 지표면을 피복하도록 하고 여름의 고온기와 장마시기에는 뿌리전단력이 우수한 이러한 초종들로 지표면이 피복되도록 하는 것이 이상적이라 생각된다. 4. 혼파처리간의 토사유출량을 비교한 결과 토사 유출 억제효과는 한지형과 나지형잔디들의 혼합형(MixtureIII)과 자생처리구(MixtureV), Italian ryegrass와 자생식물의 혼합형(MixtureIV)등에서 비교적 낮은 수치를 토사유출량을 기록하였다. 이러한 결과는 자생식물들이 비록 초기생육속도는 외래도입초종에 떨어지지만 토사유출의 억제효과면에서는 이들 외래초종에 필적할 수 있음을 나타낸다고 할 수 있겠다.중량이 약 115kg/$m^2$정도로 나타났다.소 들(환경의 의미, 사람의 목적과 지식)보다 미학적 경험에 주는 영향이 큰 것으로 나타났으며, 모든 사람들에게 비슷한 미학적 경험을 발생시키는 것 이 밝혀졌다. 다시 말하면 모든 사람들은 그들의 문화적인 국적과 사회적 인 직업의 차이, 목적의 차이, 또한 환경의 의미의 차이에 상관없이 아름다 운 경관(High-beauty landscape)을 주거지나 나들이 장소로서 선호했으며, 아름답다고 평가했다. 반면에, 사람들이 갖고 있는 문화의 차이, 직업의 차 이, 목적의 차이, 그리고 환경의 의미의 차이에 따라 경관의 미학적 평가가 달라진 것으로 나타났다.corner$적 의도에 의한 경관구성의 일면을 확인할수 있지만 엄밀히 생각하여 보면 이러한 예의 경우도 최락의 총체적인 외형은 마찬가지로 $\ulcorner$순응$\lrcorner$의 범위를 벗어나지 않는다. 그렇기 때문에도 $\ulcorner$순응$\lrcorner$과 $\ulcorner$표현$\lrcorner$의 성격과 형태를 외형상으로 더욱이 공간상에서는 뚜렷하게 경계

• Journal of the Korea Academia-Industrial cooperation Society
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• v.20 no.8
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• pp.649-656
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• 2019

Flux cored arc welding (FCAW), which is used widely in many fields, such as shipyards, bridge structures, construction machinery, and plant industry, is an alternative to shielded metal arc welding (SMAW). FCAW is used largely in the welding of carbon and alloy steel because it can be welded in all poses and obtain excellent quality in the field under a range of working conditions. In this study, the mechanical properties of welded parts were analyzed after different welding of SS400 and SM490A using FCAW. The following conclusions were drawn. The tensile test results satisfied the KS standard tensile strength in the range of 400~510 N/mm2 in all welding positions. The bending test confirmed that most of the specimens did not show surface breakage or other defects during bending and exhibited sufficient toughness, even after plastic deformation. The hardness test results were lower than the standard value of 350 Hv of KS B 0893. Similar to the hardness test, were greater than the KS reference value. The macro test revealed no internal flaws, non-metallic inclusions, bubbles or impurities on the entire cross section of the weld, and there were no concerns regarding lamination.

• Fire Science and Engineering
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• v.27 no.3
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• pp.20-29
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• 2013

To investigate numerically the effects of geometry and location of vertical opening on the thermal and chemical fire characteristics in full-scale under-ventilated compartment fires, the ventilation factor ($A\sqrt{h}$) to estimate a theoretical maximum inflow of ambient air and the mass loss rate in a heptane pool fire were fixed for all cases. It was shown that variations in door geometry affected significantly the change in thermal and chemical characteristics inside the compartment. Variations in window location resulted in the complex change in additional fire characteristics including the fire duration time and recirculating flow structure. These results were analyzed in details by the multi-dimensional flow and fire characteristics including the vent flow and fuel/air mixing phenomena.

• Proceedings of the Korea Water Resources Association Conference
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• 2022.05a
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• pp.63-63
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• 2022

기상 예보자료는 발생 가능한 재난의 예방 및 대비 차원에서 매우 중요한 자료로 활용되고 있다. 우리나라 기상청에서는 동네예보를 통해 5km 공간해상도의 1시간 간격 초단기예보와, 6시간 간격 정량강우예보(Quantitative Precipitation Forecast, QPF)의 단기예보 정보를 제공하고 있다. 그러나 이와 같은 예보자료는 강우량의 시·공간변화가 큰 집중호우와 같은 기상자료를 활용한 수문학적인 해석에는 한계가 있다. 예보자료를 수문학에 활용하기 위한 시·공간적 해상도 개선뿐만 아니라 방대한 기상 및 기후 자료의 예측성능을 개선하기 위한 다양한 연구가 진행되고 있다. 본 연구에서는 기상청이 제공하는 지역 앙상블 예측 시스템(Local ENsemble prediction System, LENS)와 종관기상관측시스템(ASOS) 및 방재기상관측시스템(AWS) 관측 데이터 및 동네예보에 기계학습 방법을 적용하여 수문학적 정량적 강수량 예측(Hydrological Quantitative Precipitation Forecast, HQPF) 정보를 생산하였다. 전처리 과정을 통해 모든 데이터의 시간해상도와 공간해상도를 동일한 해상도로 변환하였으며, 예측 변수의 인자 분석을 통해 기계학습의 예측 변수를 도출하였다. 기계학습 방법으로는 처리속도와 확장성을 고려하여 XGBoost(eXtreme Gradient Boosting) 방식을 적용하였으며, 집중호우에서의 예측정확도를 높이기 위해 확률매칭(PM) 방식을 적용하였다. 생산된 HQPF의 성능을 평가하기 위해 2020년에 발생한 14건의 호우 사상을 대상으로 태풍형과 비태풍형으로 구분하여 검증을 수행하였다.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.66 no.1
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• pp.97-104
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• 2021

This research examined the effects of different liquid manure based anaerobic digestate on the growth and yield of rice compared to chemical fertilizer. The liquid manure was produced by aerobic fermentation from swine with cow or apple pomace anaerobic digestate and treated at different concentrations. The number of grains per panicle increased in both the liquid manure-treated and chemical fertilizer treated rice. The yield index did not vary significantly between the liquid manure and chemical fertilizer. An increased concentration of liquid manure did not correlate with increases in unhulled rice. However, pH and exchangeable K in the soil increased with an increase in liquid manure. In summary, we suggest a properly applied 100% liquid manure fertilizer can replace chemical fertilizer to reduce our excessive use of inorganic fertilizer.

• Journal of the Korean Society of Food Science and Nutrition
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• v.46 no.5
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• pp.622-629
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• 2017

This study was carried out to investigate the effects of cold maceration and heat treatment prior to alcohol fermentation on the quality characteristics of wine made from Okrang grape cultivar. The results of this study show that alcohol contents of wines increased as fermentation period increased, whereas $^{\circ}Brix$ values decreased. The pH levels of wines ranged from 3.17 to 3.42 while the total acidities of wines ranged from 0.49~0.99%. The free sugar contents of wines tended to decrease as fermentation period increased. In particular, free sugar content of wine pre-treated at low temperature prior to alcohol fermentation slowly. Total polyphenol content of wine heat-treated prior to alcohol fermentation was higher than those of other wines and reached a maximum value after fermentation for 2 days. Campbell Early wine showed the strongest antioxidant effect, measured based on DPPH free radical scavenging activity, followed by Okrang wine pressing after fermentation. These results indicate that pre-treatment before wine fermentation greatly affects wine quality and biofunctional activities.

• Korean Journal of Food Science and Technology
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• v.27 no.3
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• pp.281-285
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• 1995

The persimmon leaf tea was produced from persimmon leaves by three different methods (conventional, steamed, fermented) and the changes of total vitamin C and superoxide dismutase(SOD)-like activity were investigated. The amount of total vitamin C was the highest in fermented persimmon leaf tea which was 47% of total vitamin C of raw persimmon leaves. The SOD-like activity of conventional and fermented persimmon leaf teas were a little higher than that of steamed. The total vitamin C of steamed persimmon leaf tea was decreased slowly as the extraction time was increased. That of fermented persimmon leaf tea was increased generally at $60^{\circ}C\;and\;70^{\circ}C$, and increased until 5min and then decreased at $80^{\circ}C\;and\;90^{\circ}C$, The optimum extraction condition of total vitamin C in fermented persimmon leaf tea was 3min and 5min at $80^{\circ}C\;and\;90^{\circ}C$, 5min and 10min at $60^{\circ}C$. The total vitamin C of conventional persimmon leaf tea was so little that could not be measured by DNP method. The SOD-like activity of conventional and steamed persimmon leaf teas were increased and that of fermented showed the trend of increasing-decreasing-increasing. Fermented persimmon leaf tea had higher SOD-like activity than conventional and steamed at all tested conditions, and the optimum extraction condition of SOD-like activity was 3min and 10min at $80^{\circ}C\;and\;90^{\circ}C$.

• Korean Journal of Medicinal Crop Science
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• v.13 no.4
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• pp.154-160
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• 2005

This study was performed to compare anticancer and immune activities between natural Artemisia capillaris Thunb. extract and tissue cultured plant extract (hairy root, in vitro culture, callus). The inhibitory effect of cancer cell growth, human B cell growth and productivity of cytokines were examined. Furthermore, HPLC analysis was performed to confirm the components. The anticancer activities increased by more than 55% with the cultured callus of Artemisia capillaris T. for four cancer cell lines(Lung carcunoma, Stomach adenocarcinoma, Hepatocillular carcinoma, Breast adenocarcinoma), showing higher effect than natural Artemisia capillaris T. The extracts from hairy root and in vitro culture of Artemisia capillaris T. significantly increased the immune B cell growth. The immune B cell growth effect of natural Artemisia capillaris T. was higher than that of the tissue culture plants such as hairy root, in vitro culture and callus. Both natural and tissue cultured plants showed similar effects on cytokine secretion. The similar peak size was observed between natural Artemisia capillaris T. and cultured callus in HPLC analysis. As a results, the biological activities were not observed the difference between natural Artemisia capillaris T. and cultured callus. Thus, the cultured callus will be altered natural Artemisia capillaris T. in the environmental side and the resources preservative side

• Food Science of Animal Resources
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• v.32 no.2
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• pp.228-233
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• 2012

This study was conducted to determine the effects of stevia (Stevia rebaudiana bertoni) and charcoal supplementation on growth performance, immune response and carcass characteristics of finishing pigs. A total of 420 pigs (LYD) were randomly allocated into 7 treatments with 3 replications. Dietary treatments were 1) T1 (basal diet), 2) T2 (basal diet+0.3% stevia), 3) T3 (basal diet+0.6% stevia), 4) T4 (basal diet+0.3% charcoal), 5) T5 (basal diet+0.6% charcoal), 6) T6 (basal diet+0.3% stevia+0.3% charcoal) and 7) T7 (basal diet+0.6% stevia+0.6% charcoal). During the experimental period, average daily gain (ADG) was higher in T2 and T6 groups than the other treatments (p<0.05). Feed conversion ratio (FCR) was higher in T6 group compared to the others (p<0.05). There were no significant differences in total cholesterol level and glutamic pyruvic transaminase (GPT) activity of blood among treatments. In glutamic oxaloacetic transaminase (GOT) activity, T3, T5, T6 and T7 groups showed lower values (p<0.05) compared to T1. Insulin-like growth factor-1 concentration was higher in T2 and T6 groups than the others (p<0.05), but there were no significant differences in immunoglobulin G, lymphocyte, eosinophil, basophil and atypical lymph levels among treatments. In neutrophil, T6 showed higher level compared to the others (p<0.05). In the carcass characteristics, T6 showed higher level of a carcass grade compared to the other treatments. However, carcass length did not show any significant difference among treatments. As a result, dietary supplementation of 0.3% stevia and 0.3% charcoal showed higher ADG, higher FCR and better immune response resulting in better growth performance and carcass characteristics of finishing pigs.

• Korean Journal of Ecology and Environment
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• v.33 no.2 s.90
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• pp.128-135
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• 2000

The authors surveyed the seasonal variations of environmental factors, the distributions of heterotrophic bacteria and Anabaena cylindrica growth-inhibiting bacteria at each water layer in Daechung Reservoir to verify the role of bacteria during the extinction of bloom. Average water depth at site 1, 2, and 3 were 25.5 m, 15.0 m and 12.3 m, respectively. Water temperature showed a typical pattern seasonally. The variation of DO was relatively inverse proportional to that of water temperature, although it was irregular during summer time. DO decreased gradually to early May, fluctuated sharply after then, and followed by gradual increasement after middle of September. This variation pattern was notable at surface layer. There was remarkable difference in DO concentraion between surface layer and the other water layers during the period in which DO irregulary varied. The variation range of chlorophyll-a concentraion at surface layer in summer time was broad, and it was relatively high when DO was high. The population size of heterotrophic bacteria was high from Spring to Autumn, an declined after September when the water temperature droped rapidly. Especially this variation pattern was prominent at the surface layer. Bacteria that inhibit the growth of A. cylindrica was almost not detected by June, and its distribution increased in July. Afterward, it showed different variation pattern between each site. The distribution of A. cylindrica growth-inhibiting bacteria was higher at the middle and bottom layer than the surface layer in July and October, when it was larger at all sites for the study period. This result suggests that the antagonistic bacteria exhibit higher activity when host activity drops. These results also suggest that natural water bacteria control the distirbution of cyanobacteria, especially its activity as controller is remarkable when cyanobacterial growth declines.