최근 이상기후 및 기후변화로 인해 농작물 병해충 발생이 증가하고 발생양상 또한 다양해지고 있으며, 국제 무역 및 해외 여행객 증가로 인한 외래 병해충 유입 위험성이 높아지고 있는 추세이다. 특히 대표적인 비래해충 중의 하나인 벼멸구(Nilaparvata lugens Stål, 1854)의 발생 범위, 출현율 및 빈도수가 꾸준히 증가하여 피해를 호소 하는 농가들이 많아진 반면, 이들에 대한 대응책은 피해발생의 불규칙성, 이전 자료의 부족 및 불명확성으로 인해 미비한 실정이다. 본 연구에서는 이러한 문제를 대비해 벼멸구의 온도발육모형을 이용하여, 기상자료, NCPMS와 더불어 연발생 횟수와 분포 가능 범위 및 발생 시기를 예측하였다. 또한, 벼멸구의 발생량이 많았던 충남 예산, 경남 사천, 진주의 최초발생일, 최초비래일, 최고발생일, 발생최성일 기준으로 각각 발육영점온도 및 유효적산온도를 적용하여 세대별 발생시기를 예측하였다. 최초발생일과 최초비래일은 예산 7월 9일, 7월 16일, 사천 7월 2일, 7월 19일, 진주 7월 26일, 7월 26일로 나타났으며, 최초발생일과 최초비래일 사이를 초발생일 로 적용하면 다음세대 발생이 실제 조사한 지역별 최고발생일인 예산 9월 7일, 사천 8월 9일, 진주 8월 8일과 근접 한 시기로 추정되어 효과적임을 알 수 있었다.
Bhutanese forests have been well preserved and can sequester the atmospheric carbon (C). In spite of its importance, understanding Bhutanese forest C dynamics was very limited due to the lack of available data. However, forest C model can simulate forest C dynamics with comparatively limited data and references. In this study, we aimed to simulate Bhutanese forest C dynamics at 6 plots with the Forest Biomass and Dead organic matter Carbon (FBDC) model, which can simulate forest C cycles with small amount of input data. The total forest C stock (Mg C ha-1) ranged from 118.35 to 200.04 with an average of 168.41. The C stocks (Mg C ha-1) in biomass, litter, dead wood, and mineral soil were 3.40-88.13, 4.24-24.95, 1.99-20.31, 91.45-97.90, respectively. On average, the biomass, litter, dead wood, and mineral soil accounted for 36.0, 5.5, 2.5, and 56.0% of the total C stocks, respectively. Although our modeling approach was applied at a small pilot scale, it exhibited a potential to report Bhutanese forest C inventory with reliable methodology. In order to report the national forest C inventory, field work for major tree species and forest types in Bhutan are required.
This study applied regression analysis to evaluate the impact of hourly average congestion calculated by bumper model in the congested area of each passage of each port on the peak time congestion, to suggest the model formula that can predict the peak time congestion. This study conducted regression analysis of hourly average congestion and peak time congestion based on the AIS survey study of 20 ports in Korea. As a result of analysis, it was found that the hourly average congestion has a significant impact on the peak time congestion and the prediction model formula was derived. This formula(Cp = 4.457Ca + 29.202) can be used to calculate the peak time congestion based on the predicted hourly average congestion.
In rapidly changing circumstances, the construction industry shows tendency to be more complicated and expanded and these changes are becoming the main factors aggravating uncertainty in straightening construction costs in the industry. The most important process in preliminary phase is calculation of appropriate construction sum and accurate estimation is required to accomplish it. Currently, local constructors draw up estimates by using the ‘per square meter’ calculation method or by applying of previous cases as they are. These methods become suppressive cause for making clear decisions by occurring errors in quantity survey in a way of data emission, replication and so on. Therefore, in this study, approximate estimation model of finishing construction shall be proposed to assist people to make prompt decisions in initial design stage. To develop this research, the existing quoting practices shall be presented and categorized by usage of space. To achieve this, information on performance, furnishings and unit price according to space definition has been collected in advance, which again enable ontology knowledge classification scheming database of space unit to be utilized and presented as knowledge information.
금강수계 백곡천 상류에 서식하는 미호종개(국가 천연 기념물)를 대상으로 형광물질 주입에 의한 다중표지-재포 획법(졸리-시바모델적용)으로 개체군 크기를 추정하였다. 총 어류조사지점은 335개였고, 그 중 미호종개가 출현 지 점은 217개 였다. 본 연구에서 추정한 미호종개 평균 개 체군 크기는 6,143개체였다. 이는 2009년 환경부에서 수행한 미호종개 개체군 규모와 비교 했을때보다 41% 감 소된 것이다. 백곡천에서 본 종의 감소는 미소서식지 훼 손, 퇴적물, 서식환경의 악화 등의 영향으로 판단된다. 따 라서 백곡천 본 종의 개체군 회복 미소서식지 보호를 위 해 서식지복원 프로그램이 요구된다.
고준위폐기물처분장의 설계 및 장기 성능평가를 위한 입력 자료를 확보하기 위해, 한국원자력연구원 지하처분연구시설 부지에서 실시된 경사시추에서 얻은 암석 코어를 이용하여 화강암의 열전도도를 측정하였다. 열전도도에 미치는 함수비의 영향을 조사하기 위해 여러 가지 함수비에서 화강암의 열전도도를 측정하였다. 화강암의 광물 조성, 결정구조 및 이방성의 영향을 고려하지 않고, 비교적 측정이 용이한 유효공극률과 함수비를 이용하여 화강암의 열전도도를 예측할 수 있는 간단한 실험적 관계식이 제안되었다. 이 관계식은 지하처분연구시설 부지에서 채취한 유효공극률 2.7% 이하인 화강암의 열전도도를 10% 오차 이내로 예측할 수 있다
The existing reliability evaluation models which have already developed by the corporations are so various because of using Maximum Likelihood Method. The existing models are very complicated owing to using system designing methods Therefore, it is very d
한국에 자생하는 몇몇 조경용 수목의 만개일과 기온자료를 활용하여 생물계절에 따른 기본온도와 생장도일(Growing Degree Day, GDD)을 추정하였다. 2011~2012년 조경수목의 만개일를 조사하였으며 수원기상대의 온도자료를 사용하여 일평균온도에서 기본온도를 차감한 생장도일을 계산하였다. 기준온도 설정을 위하여 0.1℃ 단위로 생장도일을 계산하여 2011~2012년 생장도일의 표준편차가 적은 온도를 기본온도로 설정하였다. 그 결과 식물의 기본온도는 진달래, 박태기나무, 팥꽃나무는 1.9℃, 공조팝나무 0℃, 장구밥나무 1.2℃로 나타났으며 만개기의 생장도일은 진달래 324.10±96.32℃, 박태기나무와 팥꽃나무 506.90±84.99℃, 공조팝나무 853.65±59.61℃, 장구밥나무 2112.70±11.74℃이다. 계산된 생장도일을 이용하여 홍릉수목원에서의 예측만개일과 실제만개일 비교 시 진달래의 예측만개일의 45%, 박태기나무의 35% 수준으로 일치하였다. 팥꽃나무는 박태기나무와 만개일이 유사하므로 비슷한 예측 정확도를 보일 것이라 생각된다.
This paper proposed a new method for estimating missing values in time series rainfall data. The proposed method integrated the two most widely used estimation methods, general linear model(GLM) and ordinary kriging(OK), by taking a weighted average of covariance matrices derived from each of the two methods. The proposed method was cross-validated using daily rainfall data at thirteen rain gauges in the Hyeong-san River basin. The goodness-of-fit of the proposed method was higher than those of GLM and OK, which can be attributed to the weighting algorithm that was designed to minimize errors caused by violations of assumptions of the two existing methods. This result suggests that the proposed method is more accurate in missing values in time series rainfall data, especially in a region where the assumptions of existing methods are not met, i.e., rainfall varies by season and topography is heterogeneous.
생애주기비용을 고려한 교량의 설계 및 유지관리에 있어서, 점검진단, 보수보강 등에 소요되는 직접적인 비용뿐만 아니라 간접적인 비용인 도로이용자비용은 중요한 비용항목으로 고려되고 있다. 직접비용과 비교하여 상대적으로 추정이 곤란한 도로이용자비용의 추정을 위하여 우회도로의 효과를 고려한 이용자지연비용과 차량운행비용의 정식화를 수행하고, 시간지체에 따른 도로이용자비용의 추정을 위한 회귀모델 개발을 위하여 교통해석과 회귀분석을 수행하였다. 개발된 회귀모델을 생애주기 비용 및 성능 기반 유지관리 전략 수립에 적용하여 도로이용자비용이 생애주기분석에 미치는 영향을 분석하고, 개발된 모델의 적용성에 대해서 고찰하였다. 도로이용자비용은 생애주기분석에 기초한 유지관리전략수립에 큰 영향을 미치며, 개발된 회귀모델은 교량의 도로이용자비용의 추정에 실용적으로 활용될 수 있을 것으로 판단된다.
Photochemical-Trajectory model was used to understand the production of ozone in the atmospheric boundary layer. This model was composed of the trajectory and the photochemical models. To calculate trajectories of air parcels, winds were obtained from the three-dimensional nonhydrostatic mesoscale model (PSU/NCAR MM5V2), and the results were interpolated into constant height surfaces. Numerical integration in the trajectory model was performed by the Runge-Kutta method. The photochemical model consisted of chemical reactions and photodissociation processes. Chemical equations were integrated by the semi-implicit Bulirsch-Stoer method.
We performed our experiments from 21 July to 23 July 1994 during the summer time for Seoul area. During the time of maximum ozone concentration in Seoul, four trajectories of air parcels which traveled from Inchon to Seoul were selected. Ozone concentrations estimated by two models are compared with observed one in Seoul area and the photochemical-trajectory model is better fitted than pure photochemical model. During the selected period, high ozone concentrations in Seoul area were more influenced by transferred pollutants from Inchon than emitted pollutants in Seoul.
The well-mixed room model has been traditionally used to predict the concentrations of contaminants in indoor environments. However, this is inappropriate because the flow fields in many indoor environments distribute contaminants non-uniformly, due to imperfect air mixing. Thus, some means used to describe an imperfectly mixed room are needed. The simplest model that accounts for imperfect air mixing is a two-zone model. Therefore, this study on development of computer program for the two-zone model is carried out to propose techniques of estimating the concentration of contaminants in the room. To do this, an important consideration is to divide a room into two-zone, i.e. the lower and upper zone assuming that the air and contaminants are well mixed within each zone. And between the zones the air recirculation is characterized through the air exchange parameter. By this basic assumption, the equations for the conservation of mass are derived for each zone. These equations are solved by using the computational technique. The language used to develope the program is a VISUAL BASIC.
The value of air exchange coefficient(f_12) is the most difficult to forecast when the concentrations of contaminants in an imperfectly mixed room are estimated by the two-zone model. But, as the value of f_12 increases, the air exchange between each zone increases. When the value of f_l2, is approximately 15, the concentrations in both zone approach each other, and the entire room may be approximately treated as a single well-mixed room. Therefore, this study is available for designing of the ventilation to improve the air quality of indoor environments. Also, the two-zone model produces the theoretical base which may be extended to the theory for the multi-zone model, that will be contributed to estimate the air pollution in large enclosures, such as shopping malls, atria buildings, airport terminals, and covered sports stadia.