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        검색결과 68

        1.
        2023.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        This study endeavors to enrich investment prospects in cryptocurrency by establishing a rationale for investment decisions. The primary objective involves evaluating the predictability of four prominent cryptocurrencies – Bitcoin, Ethereum, Litecoin, and EOS – and scrutinizing the efficacy of trading strategies developed based on the prediction model. To identify the most effective prediction model for each cryptocurrency annually, we employed three methodologies – AutoRegressive Integrated Moving Average (ARIMA), Long Short-Term Memory (LSTM), and Prophet – representing traditional statistics and artificial intelligence. These methods were applied across diverse periods and time intervals. The result suggested that Prophet trained on the previous 28 days' price history at 15-minute intervals generally yielded the highest performance. The results were validated through a random selection of 100 days (20 target dates per year) spanning from January 1st, 2018, to December 31st, 2022. The trading strategies were formulated based on the optimal-performing prediction model, grounded in the simple principle of assigning greater weight to more predictable assets. When the forecasting model indicates an upward trend, it is recommended to acquire the cryptocurrency with the investment amount determined by its performance. Experimental results consistently demonstrated that the proposed trading strategy yields higher returns compared to an equal portfolio employing a buy-and-hold strategy. The cryptocurrency trading model introduced in this paper carries two significant implications. Firstly, it facilitates the evolution of cryptocurrencies from speculative assets to investment instruments. Secondly, it plays a crucial role in advancing deep learning- based investment strategies by providing sound evidence for portfolio allocation. This addresses the black box issue, a notable weakness in deep learning, offering increased transparency to the model.
        4,000원
        3.
        2020.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        This research explores how imported automobile companies can develop their strategies to improve the outcome of their recalls. For this, the researchers analyzed patterns of recall demand, classified recall types based on the demand patterns and examined response strategies, considering plans on how to procure parts and induce customers to visit workshops, recall execution capacity and costs. As a result, recalls are classified into four types: U-type, reverse U-type, L- type and reverse L-type. Also, as determinants of the types, the following factors are further categorized into four types and 12 sub-types of recalls: the height of maximum demand, which indicates the volatility of recall demand; the number of peaks, which are the patterns of demand variations; and the tail length of the demand curve, which indicates the speed of recalls. The classification resulted in the following: L-type, or customer-driven recall, is the most common type of recalls, taking up 25 out of the total 36 cases, followed by five U-type, four reverse L-type, and two reverse U-type cases. Prior studies show that the types of recalls are determined by factors influencing recall execution rates: severity, the number of cars to be recalled, recall execution rate, government policies, time since model launch, and recall costs, etc. As a component demand forecast model for automobile recalls, this study estimated the ARIMA model. ARIMA models were shown in three models: ARIMA (1,0,0), ARIMA (0,0,1) and ARIMA (0,0,0). These all three ARIMA models appear to be significant for all recall patterns, indicating that the ARIMA model is very valid as a predictive model for car recall patterns. Based on the classification of recall types, we drew some strategic implications for recall response according to types of recalls. The conclusion section of this research suggests the implications for several aspects: how to improve the recall outcome (execution rate), customer satisfaction, brand image, recall costs, and response to the regulatory authority.
        4,600원
        4.
        2020.06 구독 인증기관 무료, 개인회원 유료
        Seaports play a huge role in Vietnam's economy, being a border gate for economic and cultural exchanges with outsiders, especially the role of goods circulation. Container cargoes are one of the types of goods with large and increasing volume through Vietnam seaports. However, the heterogeneity between the seaport and the connected infrastructure greatly affects the capacity and efficiency of port investment. This is also one of the main causes leading to a shortage of goods, excess ports in some port areas. The root cause is that the planning has not kept up with the growth of the amount of goods arriving at the port, because the issue of forecasting the volume of goods through the port is not accurate. Therefore, it is necessary to develop models of forecasting container cargo through the ports with general, scientific, and high accuracy to serve the strategy, planning and development of seaport system; the work of planning and investment in the development of seaports, shipping fleets and other auxiliary transport infrastructure works. The purpose of this study is to build suitable forecasting models with high accuracy and reliability on the total volume of container cargo throughput of the Vietnamese seaport system. Based on the methods of a statistical survey, synthesis, regression analysis, and correlation to evaluate the influence of factors on container cargo volume through Vietnam's seaports in the period of 2004-2019. By incorporating more economic factors into the regression model, the paper focuses on forecasting container cargo through the Vietnamese seaport systems, going into cargo-based forecasting in tons and TEUs. The results of this study contribute to complete the rationale for forecasting, especially forecasts related to the shipping industry and the forecast for container cargo throughput of the seaport. Finally, selecting models for forecasting container cargo volume throughput of seaports by Vietnamese conditions.
        4,600원
        7.
        2018.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Recently, the continuing operation of nuclear power plants has become a major controversial issue in Korea. Whether to continue to operate nuclear power plants is a matter to be determined considering many factors including social and political factors as well as economic factors. But in this paper we concentrate only on the economic factors to make an optimum decision on operating nuclear power plants. Decisions should be based on forecasts of plant accident risks and large and small accident data from power plants. We outline the structure of a decision model that incorporate accident risks. We formulate to decide whether to shutdown permanently, shutdown temporarily for maintenance, or to operate one period of time and then periodically repeat the analysis and decision process with additional information about new costs and risks. The forecasting model to predict nuclear power plant accidents is incorporated for an improved decision making. First, we build a one-period decision model and extend this theory to a multi-period model. In this paper we utilize influence diagrams as well as decision trees for modeling. And bayesian statistical approach is utilized. Many of the parameter values in this model may be set fairly subjective by decision makers. Once the parameter values have been determined, the model will be able to present the optimal decision according to that value.
        4,000원
        9.
        2018.05 구독 인증기관·개인회원 무료
        There are various issues affecting the financial revenues of expressways, such as new transportation systems, the opening of new roads, and free toll charges. As a result, expressway toll revenues for 2017 increased only 0.3% from the previous year. If this trend continues, the steady increase in expressway revenue may have occurred, therefore it is necessary to improve the model of annual trips and revenues considering various external variables that are occurring recently. In this study, we constructed annual trips forecasting model that can analyze more precisely the changes of road network by using new independent variables (which are not considered in existing models) such as weighted length considering regional traffic volume level and private road ratio. Also we performed a basic statistical analysis on oil prices and reflected the model as a dummy variable to improve the explanatory power of the model. And we established an analysis process to estimate the toll revenue. The results of this study can be used as the basic data for expressway financial model.
        10.
        2018.04 구독 인증기관·개인회원 무료
        비래해충인 혹명나방(Cnaphalocrocis medinalis)과 멸강나방(Mythimna separata)은 아시아의 주요 벼 재배국가에 광범위하게 분포하고 있는 벼의 주요 해충이다. 국내에서는 벼멸구, 흰등멸구와 함께 중국에서 비래하여 나타나는 것으로 알려져 있다. 혹명나방과 멸강나방의 발생지역과 통계적으로 유의미한 상관관계에 있는 환경변수를 확인하고, 국내에서의 지속적인 발생 가능성을 알아보기 위해 Maxent (Maximum Entropy Model) 3.3.2를 사용하였다.
        11.
        2016.06 KCI 등재 구독 인증기관 무료, 개인회원 유료
        This study builds counties-specific panel data and establish a stochastic rice yield forecasting model by using a fixed effect panel model based on results calculating the coefficients for the meteorological factors, and by using a variety of weather scenarios. Rice yield prediction model developed estimating equations were set to rice yield as the dependent variable, and the average temperature, accumulated temperature, daily temperature range, sunshine hours as explanatory variables, by using panel data by counties in recent 10 years. Estimation results using a fixed-effects model was able to verify that an average temperature affects to yield as quadratic form, there appeared to be significantly affected by accumulated temperature in Heading period, an average temperature in Ripening period. a rice yield prediction model is meaningful in that we can see the forecasting results in the previous. not waiting the actual survey results provided by the National Statistical Office. because this forecasting estimates is sufficient rationale material by government supply & demand measures. Finally, the study leave to future challenges with respect to establishing a prediction model developed as combined with land productivity and environmental engineering factors.
        4,200원
        12.
        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.
        13.
        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
        14.
        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
        15.
        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
        16.
        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
        17.
        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
        18.
        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
        19.
        2013.10 구독 인증기관·개인회원 무료
        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 ARIMA and their business indices. And for examples, Indium and Coal were introduced.
        20.
        2013.06 KCI 등재 구독 인증기관 무료, 개인회원 유료
        PURPOSES : This study is to investigate the relationship of socioeconomic characteristics and road network structure with traffic growth patterns. The findings is to be used to tweak traffic forecast provided by traditional four step process using relevant socioeconomic and road network data. METHODS: Comprehensive statistical analysis is used to identify key explanatory variables using historical observations on traffic forecast, actual traffic counts and surrounding environments. Based on statistical results, a multiple regression model is developed to predict the effects of socioeconomic and road network attributes on traffic growth patterns. The validation of the proposed model is also performed using a different set of historical data. RESULTS : The statistical analysis results indicate that several socioeconomic characteristics and road network structure cleary affect the tendency of over- and under-estimation of road traffics. Among them, land use is a key factor which is revealed by a factor that traffic forecast for urban road tends to be under-estimated while rural road traffic prediction is generally over-estimated. The model application suggests that tweaking the traffic forecast using the proposed model can reduce the discrepancies between the predicted and actual traffic counts from 30.4% to 21.9%. CONCLUSIONS : Prediction of road traffic growth patterns based on surrounding socioeconomic and road network attributes can help develop the optimal strategy of road construction plan by enhancing reliability of traffic forecast as well as tendency of traffic growth.
        4,000원
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