• 환경영향평가
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• 제16권5호
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• pp.351-361
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• 2007

To evaluate dominant synoptic classes which affect on $PM_{10}$ concentration in Seoul, 64 synoptic classes are classified from four seasons, 850hPa geopotential wind and lower level stability Index. In this study, we used air monitoring and meteorological data in Seoul for five years from 2001 to 2005. The results indicate that the highest occurrence frequency of synoptic class is under a strong westerly geopotential wind and stable lower atmosphere in spring. The highest $PM_{10}$ concentration of synoptic class is associated with a weak geopotential wind speed and high lower level stability. In that class, not only $PM_{10}$ but $SO_2$, $NO_2$ and CO concentrations are also higher than other classes. The analysis of spacial distribution of $PM_{10}$ concentration in each class are indicate that the influence of synoptic class are similar in the Metropolitan area in Korea. But $PM_{10}$ concentration in some areas in Kyoung-Gi are more higher than in Seoul. The relationship between $PM_{10}$ concentration and Meteorological indicator (relative humidity, temperature, surface wind speed) under same synoptic class is more correlative in Winter than other season.

• 한국해양학회지
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• 제29권4호
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• pp.414-421
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• 1994

여름철 남해 중앙해역 저층에는 14$^{\circ}C$ 이하의 저온수가 남해에서 관측된 기존의 수 온 염분 자료를 분석하여 이 저온수의 특성과 기원에 대하여 알아. 6월과 8월에 저온 수의 염분은 33.4~34.0$\textperthousand$로 4월에 비해 약 0.6$\textperthousand$ 낮으며, 특히 1983년에는 6월부터 8 월에 더 저온인 해수가 나타났다. 이와 같은 현상들은 여름철 남해의 저온수는 겨울에 형성되어 여름까지 잔류한 것이 아니고 주위해역에서 유입된 해수임을 시사한다. 이 저온수는 14$^{\circ}C$ 이하 저온수의 출현빈도분포와 제주해협 부근에서 관측된 수온 염분 자 료 분석 등에 의해 제주해협 서편해역에서 남해로 유입되는 것으로 추정된다.

• 한국해안해양공학회지
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• 제13권2호
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• pp.139-148
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• 2001

파랑에 관계하는 현상에는 월파, 표사이동, 구조물의 진동.동요, 파괴 등 방향성의 영향을 현저하게 받아들이는 것이 많다. 이들은 비선형성이 강하기 때문에 수치계산에 의한 해석이 곤란하므로, 수리모형실험으로 외력인자를 평가, 해석정도를 높일 필요성이 증대하고 있다. 본 연구는 파랑의 다양한 입사각에 따라 사석방파제의 안정성을 논의하였으며, 파괴율은 방향성규칙파에서 $30^{\circ}$, 방향성불규칙파인 경우는 40$^{\circ}$부근에서 입사각 $0^{\circ}$일 때 보다 상대적으로 크게 변동하였다. 즉, 사석방파제의 안정성에 미치는 방향성효과에 따른 것이라고 평가할 수 있다. 이들은 1/10 최대 합성유속의 방향별 빈도분포의 피크가 $20^{\circ}$~$40^{\circ}$에서 발생하는 사실과 부합된다.

• 정보처리학회논문지:소프트웨어 및 데이터공학
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• 제7권6호
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• pp.229-238
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• 2018

재난사건의 신속한 대응은 다양한 분야의 재난안전 유관기관들이 유기적으로 관계함으로써 가능하며, 이 때 사용되는 재난용어의 표준화는 필수적이다. 따라서 재난안전 분야의 전문 용어사전 구축은 각 유관기관 간의 의사소통 및 국민에게 명확한 정보 전달을 위해 수반되는 핵심 요소이다. 더불어 효율적인 용어사전 구축을 위해서는 구축 대상 용어의 우선순위 선정이 필요하다. 본 연구에서는 구체적인 용어사전 구축방향의 설정을 위하여 용어 사용 주체로 대표되는 미디어를 각각 용어사전, 뉴스미디어, 소셜미디어로 선정하고 어휘의 사용 양상을 비교하였다. 이를 위해 각 미디어에서 수집된 어휘 자원을 바탕으로 미디어별 동시 출현 양상 및 빈도 가중치 분석을 통하여 어휘의 분포를 시각화하였다. 분석 결과를 통해 어휘의 사용 양상에 따라 용어사전의 구축대상이 될 수 있는 어휘의 유형을 4가지로 분류하고, 구축대상 기준별 용어사전 구축의 우선순위 방향성을 제안하였다.

• Composites Research
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• 제16권6호
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• pp.16-22
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• 2003

음향방출 신호를 측정하면 운용 중에 구조물 내부의 파손 발생이나 진전 시점을 측정할 수 있는 장점이 있다. 본 연구에서는 보강된 복합적층 패널의 압축 시험에서 발생하는 음향방출 신호를 측정하여 누적 신호 분포와 주파수 특성을 분석하였다. 보강 패널의 좌굴 발생과 좌굴 모드의 변환시 음향방출 신호가 발생하였으며, 파손 발생 후 진전시 연속적인 신호가 나타났다. 복합재료 본딩 체결부의 강도 시험에서는 발생하는 음향방출 신호와 파손 형태와의 관계를 분석하였다. 본 연구의 음향방출 신호 분석에 사용된 특성은 시간에 따른 누적 히트(hit) 분포, 주파수 특성과 신호의 크기이다. 본 연구를 통하여 음향방출 신호의 연속적인 발생은 파손의 진전에 따라 나타나는 특성이며, 측정된 음향방출 신호의 주파수 특성을 분석함으로써 적층 복합재료에서 나타나는 파손 모드와의 관계를 유추할 수 있다. 내부 응력크기에 따라 모재균열, 층간분리 또는 디본딩, 섬유파손을 각각 100 근방, 220kHz 근방, 500kHz이상으로 분류할 수 있다.

• Journal of Forest and Environmental Science
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• 제8권1호
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• pp.51-66
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• 1992

This study was carried out to investigate the micromorphology of vessel wall sculpture such as shape of perforation plate, perforation rim, steepness of perforation plate, occurrence of vestured pit, warty layer and ray-vessel pitting on 13 species of Fagaceae in Korea. The results were summarized as follows ; 1. In the species examined, all sample species except Fagus crenata var. multinervis have simple perforation plate. But Fagus crenata var. multinervis has simple and scalariform perforation plate (it was called to combination perforation plate) in a tree stem. 2. The shapes of perforation rim could be classified into five types; Type A without tail, Type B with small tail on both sides, Type C with long tail on both sides, Type D with tail only one side and Type E with the very short interval between perforations. Among five types, Type Band C have higer frequency of distribution than the others. 3. The steepness of perforation plate measured was about 20 degree on pore zone and 43 degree on outside parts of pore zone. 4. Species with vestured pit were Q. aliena, Q, dentata, Q. variabilis, Fagus crenata var. multinervis, Castanopsis cuspidata var sieboldii, Q. acuta, Q. stenophylla, and Q. glauca. But the extent of vesturing was very slight and vestured pits were observed mainly in ray-vessel pit of some vessel elements. 5. Species with warty layer on the inner surface wall of all vessel elements were Q. acuta, Q. stenophylla, Q. glauca, Fagus crenata var. multinervis and species with warty layer of some vessel elements were Q. aliena, Q, dentata, Q. variabilis, Castanopsis cuspidata var. sieboldii. 6. Species with palisade ray-vessel pit were Q. acuta, Q. stenophylla, Q. glauca, Castanea crenata, Castanea bungeana, Q. aliena, Q. serrata, Q. mongolica, and species with scalariform ray-vessel pit was Fagus crenata var. multinervis and species with oval ray-vessel pit were Q, dentata, Castanopsis cuspidata var sieboldii.

• 전기학회논문지P
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• 제57권2호
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• pp.146-152
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• 2008

The frequency of lightning is increased due to improbable weather condition and global wanning. This phenomenon increases economical damage as well as human damage. Advanced countries like europe and north america have applied the facility standard of lightning by accumulating a store of quantitative data about lightning research. Lightning facility is composed of the lightning accepting part for induction lightning, ground connected electrode which conducts lightning current. The lightning accepting part is composed of normal rod, horizontal conductor, ESE lightning rod. Moreover, lightning accepting part is taken to use by the method of protection. This paper suggests HEC(Hybrid ESE-Conductor) method which mixes horizontal conductor and ESE lightning rod. This is also discovered by experiment that the starting point of corona discharge current is low, so it is efficient for lightning protection comparing with other methods. Moreover, distribution of electric field is analyzed qualitatively by finite element method. It also results in the relation of the starting point of corona discharge current. Corona discharge current makes minute current about some ${\mu}A$ between the electrodes by the strength of electric field. Also it occurs insulation destruction of gas, and it is developed to the shape of streamer by increase of the strength of electric field. We can find that the initial occurrence of streamer and contact probability of lightning can have advantage after researching the starting point of corona discharge current and discharge current of lightning striking point. This research demonstrates that the suggested HEC method is economically competitive as a lightning protection facility, and it takes a capably perfect role.

• 농업과학연구
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• 제44권1호
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• pp.40-49
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• 2017

Cultural practices for adzuki bean and the distribution of weed species in the south-west regions of Korea were surveyed to provide information on effective weed management. Approximately 27.5% of the farm households were growing adzuki bean in an area larger than 1 ha while the rest grew the crop in an area smaller than 1 ha. Of all adzuki bean growers, 17.1% seeded in early June, 8.6% in mid June, 34.3% in late June, 17.1% in early July, 20.0% in mid July, and 2.9% in late July. The average planting distance was $71.0{\times}29.5cm$. From the 40 surveys in adzuki bean fields, 35 weed species in 17 families were identified. According to the occurrence frequency, the dominant weed species were Digitaria sanguinalis, Acalypha australis, Cyperus amuricus, Echinochloa crus-galli, and Amaranthus nangostanus in decreasing order of dominance. However, based on dry weight, Chenopodium album (34.4%) was the most dominant followed by Acalypha australis (21.9%), Amaranthus nangostanus (19.1%), Digitaria sanguinalis (7.5%), and Portulaca oleracea (6.1%). The exotic weeds found in the field of adzuki were Ipomoea hederacea, Abutilon avicennae, and Celosia argentea. The plant heights of I. hederacea, A. avicennae, and C. argentea were 259 cm, 98 cm, and 76 cm, respectively, while the fresh weights were 850 g, 66 g, and 101 g, respectively. Integrated weed management systems utilizing mechanical, chemical, and biological control techniques need to be developed for effective weed management in adzuki bean production.

• 한국해안·해양공학회논문집
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• 제30권4호
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• pp.191-199
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• 2018

본 연구에서는 한국 연안의 해상풍력 발전을 위한 적지를 검토하기 위해 기상청에서 제공하는 20개 지점의 풍속 자료를 수집하고 이를 분석하였다. 관측된 풍속 자료의 분석을 위하여 Rayleigh 모델과 Weibull 모델을 이용하였으며, 풍속 출현빈도에 따라 연간 부존량을 추정하였다. 풍력발전기 모델로는 출력 1.5~5 MW의 7종류를 선정하여 각각의 성능곡선을 이용하였다. 그 결과, 풍속이 7.15 m/s 이상인 지점에서는 Repower-5 MW의 터빈이 높은 에너지 생산이 가능한 것으로 나타났으나 그 이하의 풍속에서는 G128-4.5 MW의 터빈이 유리한 것으로 나타났다. 10 m/s 이상의 풍속 출현율이 높은 마라도, 거제도 및 포항의 경우 REpower사의 5 MW급 해상풍력발전기 설치 시 설비이용률이 56.49%, 50.92%, 50.08%로 높게 나타났다.

• 한국조경학회지
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• 제26권3호
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• pp.66-77
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• 1998

The purpose of this study is on identifying real condition of naturalized plants in urban green space. For this, Chollabak-do region was selected for case study. The occurring frequency and distribution status was investigated by field survey. The area of green open space, level of management and passed years after construction etc, were analized to identify the influence on occurrence of naturalized plants. The result is as follows: 1. In 18 sites, 145 taxa as weed species including naturalized plants were occurred. Average No. of occurring taxa is 22.7. Two families of plants, Graminae and compositae charged the most part. Also the rate of naturalized plant among them is 29.7%. 2. Naturalized species showing high occurring rate are 14 taxa of compositae, 5 taxa of Gramineae, Leguminosae and 4 taxa of cruciferae. These plants of previous four somatic polymorphism among all the naturalized plants. 3. The taxa number of naturalized plants were reducedby intensive management. But the rate of naturalized plants in extensively managed area was relatively lower than intensively managed one. Naturalizd plants were widely distributed in most of urban green space with being cognitioned as whole weed. 4. In origin of naturalized plants, the taxa from north America were 16 and the taxa from Europe were 16. Therefore the rate originated from north America and Europe charged high part as 68.2%. The rate of Annual, Biennial and Perennial were each 78.7%, 21.3%. The alternative of management for control aganist disturbance by Annual & Biennial required. 5. Multi-relations analysis shows 0.81 which is the relatively high interralation between the number of emerged axa and that of naturalized ones. 6. The number of naturalized species has no relation to the lapse of years after construction of open-space. Especially it was identified that weed control in the beginning of construction is very important. On the other hand the relation between Ys and Xp was Ys=1.784Xp+4.646.