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        검색결과 259

        41.
        2016.06 KCI 등재 구독 인증기관 무료, 개인회원 유료
        작물 재배 시 주요 해충 발생에 대해 한두 달 이상 앞선 계절전망이 가능하다면 농가의 해충관리 의사결정이 보다 효율적으로 이루어질 수 있을 것이다. 본 연구에서는 국내 해충 발생과 통계적으로 유의미한 원격상관관계에 있는 기후현상을 찾기 위해 Moving Window Regression (MWR) 기법을 활용하였다. 벼멸구의 발생과 비래는 장기간에 걸쳐 여러 지역에서 연속적으로 일어나는 사건이기 때문에 비슷한 시공간적 규모 를 갖는 기후현상과 통계적인 연관성을 가질 가능성이 높아 본 연구의 대상 해충으로 선택하였다. MWR 통계 분석의 반응변수로써 1983년부터 2014년까지 국내 벼멸구 발생면적 자료를 사용하였고, 10개의 기후모형에서 생산되는 10개의 기후변수를 예보 선행시간별로 추출하여 설명변 수로 사용하였다. 최종적으로 선정된 각 MWR 모형의 특정 시기와 지역의 기후변수는 연간 벼멸구 발생면적 자료와 통계적으로 유의한 상관관 계를 보였다. 결론적으로, 본 연구에서 개발한 MWR 통계 모형을 통해 국내 벼멸구 발생 위험도에 따른 선제적 대응을 위한 벼멸구 계절전망이 가능할 것으로 보인다.
        4,000원
        42.
        2016.06 KCI 등재 구독 인증기관 무료, 개인회원 유료
        PURPOSES : This study aims to examine the differences between the existing traffic demand forecasting method and the traffic demand forecasting method considering future regional development plans and new road construction and expansion plans using a four-step traffic demand forecast for a more objective and sophisticated national highway maintenance. This study ultimately aims to present future pavement deterioration and budget forecasting planning based on the examination. METHODS: This study used the latest data offered by the Korea Transport Data Base (KTDB) as the basic data for demand forecast. The analysis scope was set using the Daejeon Metropolitan City’s O/D and network data. This study used a traffic demand program called TransCad, and performed a traffic assignment by vehicle type through the application of a user equilibrium-based multi-class assignment technique. This study forecasted future traffic demand by verifying whether or not a realistic traffic pattern was expressed similarly by undertaking a calibration process. This study performed a life cycle cost analysis based on traffic using the forecasted future demand or existing past pattern, or by assuming the constant traffic demand. The maintenance criteria were decided according to equivalent single axle loads (ESAL). The maintenance period in the concerned section was calculated in this study. This study also computed the maintenance costs using a construction method by applying the maintenance criteria considering the ESAL. The road user costs were calculated by using the user cost calculation logic applied to the Korean Pavement Management System, which is the existing study outcome. RESULTS : This study ascertained that the increase and decrease of traffic occurred in the concerned section according to the future development plans. Furthermore, there were differences from demand forecasting that did not consider the development plans. Realistic and accurate demand forecasting supported an optimized decision making that efficiently assigns maintenance costs, and can be used as very important basic information for maintenance decision making. CONCLUSIONS : Therefore, decision making for a more efficient and sophisticated road management than the method assuming future traffic can be expected to be the same as the existing pattern or steady traffic demand. The reflection of a reliable forecasting of the future traffic demand to life cycle cost analysis (LCCA) can be a very vital factor because many studies are generally performed without considering the future traffic demand or with an analysis through setting a scenario upon LCCA within a pavement management system.
        4,200원
        43.
        2016.04 구독 인증기관·개인회원 무료
        This study was performed to apply and to utilize the digital forecasting information for Integrated Pest Management at pepper field in Chungbuk province. Chemical spray according to the forecasting prediction using FarmIPM and NCPMS were compare to the that of no control and conventional control. Pests such as Oriental tobacco budworm, Western flower thrips, and Cotton aphids were investigated the control effect by the forecasting modeling information at three pepper plots. Damaged fruit ratio (%) of Oriental tobacco budworm was ordered into no treatment (30) > forecasting (20) > conventional (12), but damages by other pest was insignificant. The frequency of forecasting control was ordered into NCPMS (31) > conventional control (17) > FarmIPM (8). Damaged fruit ratio (%) of Oriental tobacco budworm was ordered into no treatment (35.5) > NCPMS (26.1) > FarmIPM (24.6) > conventional (13.9). Density of western flower thrips was higher but had no problematic by the chemical control when it is hard to analyze the damage by cotton aphid occurrence. Damage by cotton aphids has no prediction of forecasting but done with 6th chemical spray, and their damage ratio (%) was ordered into no treatment (67.7) > FarmIPM (16.2) > NCPMS (11.3) > conventional treatment (4.8). At an analysis of economic value, gross profit was highest in FarmIPM and next to NCPMS > conventional control.
        44.
        2016.04 구독 인증기관·개인회원 무료
        A seasonal outlook for crop insect pests is most valuable when it provides accurate information for timely management decisions. In this study, we investigated the probable relationship between climatic phenomena and pest infestations in Korea using two statistical methods. Brown planthopper was selected because of its migration characteristics, which fits well with the concept of our statistical modelling – utilizing a long-term, multi-regional influence of selected climatic phenomena to predict a dominant biological event at certain time and place. The moving window regression (MWR) model showed high correlation between the national infestation trends of brown planthopper and some tempo-spatial climatic variables near its sequential migration path, while the climate index regression (CIR) model resulted in a relatively low correlation compared to the MWR model. Overall, the statistical models developed in this study showed a promising predictability for rice brown planthopper infestation in Korea, although the dynamical relationships between the infestation and selected climatic phenomena need to be further elucidated.
        45.
        2016.03 KCI 등재 구독 인증기관 무료, 개인회원 유료
        It is critical to forecast the maximum daily and monthly demand for power with as little error as possible for our industry and national economy. In general, long-term forecasting of power demand has been studied from both the consumer’s perspective and an econometrics model in the form of a generalized linear model with predictors. Time series techniques are used for short-term forecasting with no predictors as predictors must be predicted prior to forecasting response variables and containing estimation errors during this process is inevitable. In previous researches, seasonal exponential smoothing method, SARMA (Seasonal Auto Regressive Moving Average) with consideration to weekly pattern Neuron-Fuzzy model, SVR (Support Vector Regression) model with predictors explored through machine learning, and K-means clustering technique in the various approaches have been applied to short-term power supply forecasting. In this paper, SARMA and intervention model are fitted to forecast the maximum power load daily, weekly, and monthly by using the empirical data from 2011 through 2013. ARMA(2,1,2)(1,1,1)7 and ARMA (0,1,1)(1,1,0)12 are fitted respectively to the daily and monthly power demand, but the weekly power demand is not fitted by AREA because of unit root series. In our fitted intervention model, the factors of long holidays, summer and winter are significant in the form of indicator function. The SARMA with MAPE (Mean Absolute Percentage Error) of 2.45% and intervention model with MAPE of 2.44% are more efficient than the present seasonal exponential smoothing with MAPE of about 4%. Although the dynamic repression model with the predictors of humidity, temperature, and seasonal dummies was applied to foretaste the daily power demand, it lead to a high MAPE of 3.5% even though it has estimation error of predictors.
        4,000원
        46.
        2016.02 KCI 등재 구독 인증기관 무료, 개인회원 유료
        표고버섯 재배 임가들이 생산량과 출하 시기를 결정하는 데 가격은 결정적인 역할을 하지만, 표고버 섯 가격 전망에 대한 연구는 미진한 상황이다. 이 연구의 목적은 표고버섯의 중품, 상품, 특품의 월별 가격자료를 이용하여 시계열 분석 모형을 구축하고, 이들의 단기 가격 예측력을 비교하는 것이다. 이를 위해, 2002∼2015년 동안의 등급별 가락시장 표고버섯 가격자료를 이용하여 Seasonal Exponential Smoothing 모델, Seasonal ARIMA with intercept 모델, Seasonal ARIMA without intercept 모델, Seasonal Dummy 모델을 포함하는 네가지 형태의 시계열 분석 모형을 구축하고 단기 가격을 예측하였 다. 또 통계적 검증방법을 이용하여 이들 모델의 가격 예측력을 비교하였다. 분석 결과, Seasonal ARIMA without intercept 모형의 가격 예측 능력이 가장 우수한 것으로 나타났다. 향후 다른 단기 소 득 임산물의 가격 예측에도 이들 모델을 적용함으로써 임가들의 생산 출하에 대한 의사결정에 유용한 정보를 제공할 수 있을 것이다.
        4,200원
        47.
        2015.10 구독 인증기관·개인회원 무료
        Grapholita molesta occur four times a year and Carposina sasakii occur twice a year, and both pests do damage on stone fruits such as peach, apple, plum, apricot, etc. Grapholita molesta is worldwide distributed in temperate and subtropical areas including South Korea. But, Carposina sasakii distributed in South Korea, Japan, China and Asia, and has been managed as an important import quarantine pest by the authorities of United States, Canada and Taiwan. Forecasting of both pests in Korea is currently done through the investigation of 1,000 fruits per 10 trees (100 fruits / tree) in designated peach orchard. However, this method is very difficult to observe the pest by bagging of peach and require too much time and labor. Therefore, we tried to carry out a new forecasting method by using of sex pheromone traps for newly standardized method as an alternative. Using sex pheromone trap, attractiveness of G. molesta was proved to be 2.5 > 1.5 > 0.5 m by the height and the border => outside > center by the position. Attractiveness of C. sasakii made no difference in height, but, more trapped at the center and border than outside in position at peach orchard.
        48.
        2015.09 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Aggregate Production Planning determines levels of production, human resources, inventory to maximize company’s profits and fulfill customer's demands based on demand forecasts. Since performance of aggregate production planning heavily depends on accuracy of given forecasting demands, choosing an accurate forecasting method should be antecedent for achieving a good aggregate production planning. Generally, typical forecasting error metrics such as MSE (Mean Squared Error), MAD (Mean Absolute Deviation), MAPE (Mean Absolute Percentage Error), and CFE (Cumulated Forecast Error) are utilized to choose a proper forecasting method for an aggregate production planning. However, these metrics are designed only to measure a difference between real and forecast demands and they are not able to consider any results such as increasing cost or decreasing profit caused by forecasting error. Consequently, the traditional metrics fail to give enough explanation to select a good forecasting method in aggregate production planning. To overcome this limitation of typical metrics for forecasting method this study suggests a new metric, WACFE (Weighted Absolute and Cumulative Forecast Error), to evaluate forecasting methods. Basically, the WACFE is designed to consider not only forecasting errors but also costs which the errors might cause in for Aggregate Production Planning. The WACFE is a product sum of cumulative forecasting error and weight factors for backorder and inventory costs. We demonstrate the effectiveness of the proposed metric by conducting intensive experiments with demand data sets from M3-competition. Finally, we showed that the WACFE provides a higher correlation with the total cost than other metrics and, consequently, is a better performance in selection of forecasting methods for aggregate production planning.
        4,000원
        49.
        2015.06 구독 인증기관·개인회원 무료
        Fashion is primarily based on adoption of trends by consumers in textiles, clothing, footwear, jewelry and art, inter alia. As fashion is based on human preferences, it is characterized by dynamic changes throughout seasons and years, short life cycles, low predictability and high volatility of demand and impulse purchases. In the dynamic environment of apparel markets, fashion firms aim at successfully forecasting both the desirability of new collections and the volumes of each item produced and released to the market under terms of substantial levels of uncertainty. When demand for an item exceeds its supply, the firm is likely to lose additional profits that could have been collected had a sufficient volume of this item been present in the market. Alternatively, if the supply of an item surpassed its demand, it would remain unsold, thereby generating loss equal to its marginal production and distribution costs. The paper proposes a forecasting model that enhances the accuracy of fashion trend forecasting in the context of multiple variants of colour clothing. The model aims at maximizing profits of the firms, while minimizing the forecasting error and reducing the costs that result from excess capacity of production or, alternatively, from loss of potential revenues due to low demand.
        50.
        2015.05 KCI 등재 구독 인증기관 무료, 개인회원 유료
        국가차원의 슈퍼컴퓨팅 성능수요 예측은 슈퍼컴퓨터를 활용하는 계산과학분야 의 연구자나 연구개발 인프라를 구축⋅운영하고 있는 전문기관, 과학기술 인프라구축을 주도 할 정부기관에 있어서 매우 중요한 정보이다. 본 연구는 그동안 진행되었던 슈퍼컴퓨터 성능관련 예측활동 분석을 통해 과학기술 역량 에 영향을 미치는 요인들을 도출하고 이를 슈퍼컴퓨터 기술진보 추세에 적용한 복합 예측모 형을 제안하였다. 횡단면분석에서는 슈퍼컴퓨팅 성능에 영향을 미칠 것으로 판단되는 GDP, GERD, 연구원수, SCI논문수를 고려한 다중회귀분석을 수행하였다. 그리고 횡단면분석 결과 에 Top500 자료의 성능(Rmax)값을 이용한 시계열분석을 통해 도출된 기간별 기술진보율을 곱하여 슈퍼컴퓨터의 성능을 예측하였다. 제안된 예측모형을 바탕으로 세계 슈퍼컴퓨터 500위의 시계열자료를 이용하여 한국이 2016년에 보유해야 할 슈퍼컴퓨터 성능규모를 예측하였다. 횡단면분석과 기술진보율을 적 용하여 2016년 한국의 슈퍼컴퓨팅 성능수요를 예측해본 결과 현재의 추세를 이용할 경우 15~30PF 정도, 목표 국가수준의 추세를 이용할 때 20~40PF 정도의 컴퓨팅 역량이 필요할 것으로 예측되었다. 이 결과는 단순 회귀분석을 적용한 결과인 9.6PF와 횡단면분석을 적용 한 결과인 2.5PF와 큰 차이를 나타내었다.
        5,800원
        51.
        2015.04 구독 인증기관·개인회원 무료
        Recently an outbreaked pest belongs to Hemiptera: Recaniidae, Ricanula sp. is greatly concerned about the outspreading throughout the South of Korea by wide range of host, including Cornelian cherry, Jujube, and peach trees. In Chungbuk province, this pest was first occurred at Jincheon and Okcheon in 2012, Cheongju in 2013 and now found out at Eumseong and Goesan in 2015. Ricanula sp. was oviposited directly into one-year twig, did damages on fruit-bearing formation and finally withered the host. This study was performed to understand the ovipositional characteristics and to develop the standardized forecasting method. Oviposition by Ricanula sp. was abundant in tree than in bush, adult laid eggs on new inner twigs and then covered with wax compound. Total no. of oviposited egg-mass was 10 to 318, and that of on new twig was 5 to 185 per tree, with different to host trees. Thickness of oviposited twigs were done within 2 ~ 5.5 mm and the height was mostly founded with range of 1 to 2 m, founded with highest height over 3 m. Oviposited no. of egg-mass within 30 cm twig was appeared differently from 2 to 7 every host. From based on this investigated result, we provide this for standardized forecasting method. This pest will need to control when egg-mass will occur over 2 at new twig, within 30 cm from the tip, set as total 25 point/ 5 plants (5 point per plant).
        52.
        2015.03 KCI 등재 구독 인증기관 무료, 개인회원 유료
        There have been various studies on measurements of flood risk and forecasting models. For river and dam region, PDF and FVI has been proposed for measurement of flood risk and regression models have been applied for forecasting model. For Bo region unlikely river or dam region, flood risk would unexpectedly increase due to outgoing water to keep water amount under the designated risk level even the drain system could hardly manage the water amount. GFI and general linear model was proposed for flood risk measurement and forecasting model. In this paper, FVI with the consideration of duration on GFI was proposed for flood risk measurement at Bo region. General linear model was applied to the empirical data from Bo region of Nadong river to derive the forecasting model of FVI at three different values of Base High Level, 2m, 2.5m and 3m. The significant predictor variables on the target variable, FVI were as follows: ground water level based on sea level with negative effect, difference between ground altitude of ground water and river level with negative effect, and difference between ground water level and river level after Bo water being filled with positive sign for quantitative variables. And for qualitative variable, effective soil depth and ground soil type were significant for FVI.
        4,000원
        53.
        2015.03 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Spare part management is very important to products that have large number of parts and long lifecycle such as automobile and aircraft. Supply chain must support immediate procurement for repair. However, it is not easy to handle spare parts efficiently due to huge stock keeping units. Qualified forecasting is the basis for the supply chain to achieve the goal. In this paper, we propose an agent based modeling approach that can deal with various factors simultaneously without mathematical modeling. Simulation results show that the proposed method is reasonable to describe demand generation process, and consequently, to forecast demand of spare parts in long-term perspective.
        4,000원
        54.
        2014.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Recently, the mineral resource protection policies and regulations in production countries of natural resources including rare metals are becoming more stringent. Such environment makes which market has malfunction. In other word, those are not perfect or pure market. Therefore because each market of natural resources have special or unique characters, it is difficult to forecast their market prices. In this study, we constructed several models to estimate prices of natural resources using statistical tools like ARIMA and their business indices. And for examples, Indium and Coal were introduced.
        4,000원
        55.
        2014.10 KCI 등재 구독 인증기관 무료, 개인회원 유료
        본 연구는 단일 입력 전이함수모형(Single-input transfer function model)을 적용하여 여수연안 2010년의 월평균 표면수온의 예측을 시도하였다. 전이함수모형을 수립하기 위한 입력시계열과 출력시계열은 각각 여수지방의 10년(2000-2009년)간의 월평균 기온자료와 표면수온자료를 이용하였다. 전이함수모형을 수립하기 위하여 입·출력 시계열을 사전백색화하고, 입·출력 시계열간의 각 시차에 대한 교차상관함수를 결정하였다. 교차상관함수는 음의 모든 시차에서 유의한 값을 갖지 않아 기온과 표면수온사이는 일방적 인과관계를 보였다. 또한 교차상관함수의 시차 0과 1에서 유의한 값을 보였다. 이러한 교차상관함수의 특징에 따라 입·출력시계열간 전이함수의 시차와 분모 및 분자의 차수(b, r, s)는 (0, 1, 0)으로 식별되었다. 구축된 전이함수모형에 따르면 기온과 표면수온 사이의 시차는 존재하지 않았다. 여기서 현재의 표면수온은 1개월 전의 표면수온과 선형관계가 있음을 보였으며, 잡음모형은 ARIMA(1,0,1)(2,0,0)12로 식별되었다. 전이함수모형에 의한 월평균 표면수온의 예측치는 실측치에 비하여 전반적으로 0.3-1.3℃ 높은 경향을 보였으며, 6.4 %의 평균절대백분율 오차를 포함하였다. 이러한 결과는 8.3 %의 평균절대백분율오차를 보인 ARIMA 모형에 비하여 향상된 예측성능을 보이는 것이며, 표면 수온의 시계열적 예측을 시도할 경우, ARIMA 모형보다 전이함수모형의 적용을 통하여 그 예측성능의 개선 가능성을 기대할 수 있음을 시사하고 있다.
        4,000원
        56.
        2014.09 KCI 등재 구독 인증기관 무료, 개인회원 유료
        본 연구는 개인의 사회적 배척 경험과 소속 욕구 수준이 사회적 사건에 대한 정서 예측 및 정서 예측 오류의 크기에 미치는 영향을 검증하기 위하여 실시되었다. 참가자들은 예비 연구를 통해 구성된 8가지 종류의 사회적 사건과 비사회적 사건에 대해 각 사건이 실제로 벌어진다면 얼마나 기쁠지 혹은 괴로울지에 대해 응답하였다. 연구 1에서는 사회적 배척 경험이 많을수록 또는 소속 욕구가 높을수록 비사회적 사건에 비해 사회적 사건이 가 지고 올 괴로움을 더욱 부정적으로 예측하는 것으로 나타났다. 그러나 연구 2에 의하면, 사회적 배척 경험이 많 거나 소속 욕구가 높다고 해서 실제로 사회적 부정적 사건을 경험했을 때 더 괴로운 것은 아니라는 것이 밝혀졌 다. 본 연구의 결과는 사회적 배척 경험이 많거나 소속 욕구가 높은 개인의 사회적 사건에 대한 민감한 정서 예 측이 그들이 사회적 사건으로부터 경험하는 실질적 괴로움이 더 크기 때문이 아니라 사회적 사건으로 인해 겪게 될 미래 정서를 과대 추정하기 때문이라는 것을 시사한다. 본 연구 결과의 함의와 제한점, 추후 연구에 대한 논의가 제시되었다.
        4,300원
        57.
        2014.08 KCI 등재 구독 인증기관 무료, 개인회원 유료
        In recent years, Smart Water Grid (SWG) concept has globally emerged over the last decade and also gained significant recognition in South Korea. Especially, there has been growing interest in water demand forecast and this has led to various studies regarding energy saving and improvement of water supply reliability. In this regard, this study aims to develop a nonlinear ensemble model for hourly water demand forecasting which allow us to estimate uncertainties across different model classes. The concepts was demonstrated through application to observed from water plant (A) in the South Korea. Various statistics (e.g. the efficiency coefficient, the correlation coefficient, the root mean square error, and a maximum error rate) were evaluated to investigate model efficiency. The ensemble based model with an cross-validate prediction procedure showed better predictability for water demand forecasting at different temporal resolutions. In particular, the performance of the ensemble model on hourly water demand data showed promising results against other individual prediction schemes.
        4,500원
        58.
        2014.05 구독 인증기관·개인회원 무료
        오늘날 물류 서비스 산업에서는 수요예측을 통해 불확실성을 줄여나가는 것이 경영상 매우 중요한 이슈로 제기되고 있다. 비교적 시장 점유율이 견고하게 유지되는 제조산업과는 달리 물류 서비스 산업은 매우 빠른 속도로 시장이 성장하고 변화하기 때문에, 시장 환경의 변화를 반영하여 정확한 수요 예측에 기반한 적절한 물류 서비스 공급을 위한 운송 및 인력 공급 계획을 수립하여 운용하여야 한다. 본 연구는 물류 서비스 업계를 위하여 추세 요소, 계절 요소 등 수요에 영향을 미치는 요소를 분석하고, 영향 효과를 산출하여 물류 서비스 산업을 위한 수요예측 시스템에 반영하는 방안을 연구하였다. 특히 지역 특산물, 기상효과, 음력으로 발생하는 명절 효과 등 수요를 크게 변화시키는 중요 영향 요소에 의한 수요 변동을 수요 예측에 활용하는 방안을 도출함으로써, 물류 서비스 산업계의 수요 예측을 위하여 분해법(Decomposition Method)을 제시하였다.
        60.
        2014.03 KCI 등재 구독 인증기관 무료, 개인회원 유료
        During a flood season, Bo region could be easily exposed to flood due to increase of ground water level and the water drain difficulty even the water amount of Bo can be managed. GFI for the flood risk is measured by mean depth to water during a dry season and minimum depth to water and tangent degree during a flood season. In this paper, a forecasting model of the target variable, GFI and predictors as differences of height between ground water and Bo water, distances from water resource, and soil characteristics are obtained for the dry season of 2012 and the flood season of 2012 with empirical data of Gangjungbo and Hamanbo. Obtained forecasting model would be used for keep the value of GFI below the maximum allowance for no flooding during flooding seasons with controlling the values of significant predictors.
        4,000원
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