In this study, we proposed a model for forecasting power energy demand by investigating how outside temperature at a given time affected power consumption and. To this end, we analyzed the time series of power consumption in terms of the power spectrum and found the periodicities of one day and one week. With these periodicities, we investigated two time series of temperature and power consumption, and found, for a given hour, an approximate linear relation between temperature and power consumption. We adopted an exponential smoothing model to examine the effect of the linearity in forecasting the power demand. In particular, we adjusted the exponential smoothing model by using the variation of power consumption due to temperature change. In this way, the proposed model became a mixture of a time series model and a regression model. We demonstrated that the adjusted model outperformed the exponential smoothing model alone in terms of the mean relative percentage error and the root mean square error in the range of 3%~8% and 4kWh~27kWh, respectively. The results of this study can be used to the energy management system in terms of the effective control of the cross usage of the electric energy together with the outside temperature.

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.

Overfishing capacity has become a global issue due to over-exploitation of fisheries resources, which result from excessive fishing intensity since the 1980s. In the case of Korea, the fishing effort has been quantified and used as an quantified index of fishing intensity. Fisheries resources of coastal fisheries in the Korean waters of the East Sea tend to decrease productivity due to deterioration in the quality of ecosystem, which result from the excessive overfishing activities according to the development of fishing gear and engine performance of vessels. In order to manage sustainable and reasonable fisheries resources, it is important to understand the fluctuation of biomass and predict the future biomass. Therefore, in this study, we forecasted biomass in the Korean waters of the East Sea for the next two decades (2017~2036) according to the changes in fishing intensity using four fishing effort scenarios;  ,  , 0.5× and 1.5× . For forecasting biomass in the Korean waters of the East Sea, parameters such as exploitable carrying capacity (ECC), intrinsic rate of natural increase (r) and catchability (q) estimated by maximum entropy (ME) model was utilized and logistic function was used. In addition, coefficient of variation (CV) by the Jackknife re-sampling method was used for estimation of coefficient of variation about exploitable carrying capacity (CVECC). As a result, future biomass can be fluctuated below the BPY level when the current level of fishing effort in 2016 maintains. The results of this study are expected to be utilized as useful data to suggest direction of establishment of fisheries resources management plan for sustainable use of fisheries resources in the future.

The present research examines the Uncertainty-Prediction Asymmetry (UPA) hypothesis, that low certainty incidental emotions, compared to their high certainty counterparts, lead to utility overprediction and to lower forecasting error. Introduction Cognitive appraisals of emotion have been included in the state-of-the-art theory of emotion and decision-making (Lerner & Keltner, 2000; Lerner, Li, Valdesolo, & Kassam, 2015). For instance, Tiedens & Linton (2001) discuss how happiness involves appraisals of high certainty, and sadness involves appraisals of low certainty. In terms of forecasting, systematic processing is generally considered to lead to less forecasting error compared to heuristic processing. Tiedens & Linton (2001) argue that, if accuracy is the ultimate goal the individual needs to rely on more thoughtful processes. Seeking a state of certainty is more cognitively engaging and requires more cognitive resources. But how do people predict future utilities in the first place? Theoretical background Kahneman & Thaler (2006) analyze forecasting as a two-step procedure, encompassing a current prediction as well as a future event. Breaking down the present and future situation allows researchers to assess accuracy and detect how errors occur. Kahneman & Snell (1992) report that people tend to underpredict future utilities. Typically, the experienced utility is higher (i.e. more liked or less disliked) compared to the earlier prediction. In the present paper we argue that emotional uncertainty leads to utility overprediction and thus reduces forecasting error. This hypothesis is in line with the Appraisal-Tendency Framework (ATF-overview in Lerner et al., 2015). According to the ATF, an emotion may trigger a cognitive predisposition to assess future events in line with the central appraisal dimensions that triggered that emotion. Such appraisals provide a perceptual schema for interpreting subsequent situations. In the context of the present research, the certainty-uncertainty cognitive appraisal is hypothesized to trigger a predisposition that affects the utility prediction mechanism and leads to utility overprediction. This hypothesis is also in line with the uncertainty intensification hypothesis (Bar-Anan, Wilson, & Gilbert, 2009), according to which the uncertainty of experienced emotions makes unpleasant events more unpleasant and pleasant events more pleasant. The present research examines an Uncertainty-Prediction Asymmetry (UPA) hypothesis. In three experimental studies we test the hypotheses that low certainty incidental emotions, compared to their high certainty counterparts, lead to utility overprediction (H1) and to lower forecasting error (H2). Emotional certainty, as an appraisal dimension of emotions, is expected to create a prediction asymmetry through its effect on both predicted utility and forecasting error. The mediating role of heuristic processing in the relationship between emotional certainty and forecasting error is also investigated. Experiment 1 The first experiment examines the hypothesis that low emotional certainty leads to utility overprediction (H1). Eighty postgraduate students were randomly assigned to a high emotional certainty (disgust) vs. a low emotional certainty (fear) condition. Emotion induction involved exposure to pretested video clips (see Han et al., 2012). Following this manipulation, the experimental utility (a small candy bar) was distributed and participants were encouraged to consume it (see Kahneman & Snell, 1992). They were then asked to report on 13-point scales how much they liked the utility and to predict how much they would like it in the future consumption occasion (a week later). The results revealed a significant difference in predicted utility between the high (M = 2.22, SD = 1.33) and low (M =3.65, SD = 1.37) emotional certainty conditions (F = 4.43, p = 0.04, partial eta squared = 0.10). Experiment 2 The second experiment includes a “future event”, that is measures of the utility that was originally predicted, in order to also estimate forecasting error. The experiment therefore tests if (a) the main effect of emotional uncertainty on predicted utility is confirmed (H1) and (b) there is a significant main effect of emotional uncertainty on forecasting error (H2). In addition, this experiment examines whether these effects are independent of the valence appraisal dimension of emotions. Given that Experiment 1 involved two negatively valenced emotions, emotional valence (positive vs. negative) was included in the experimental design. Seventy three postgraduate students participated in a five-consecutive-days experiment. During the first day, participants were randomly assigned to a fear (negative valence, low certainty), disgust (negative valence, high certainty), hope (positive valence, low certainty) or happiness (positive valence, high certainty) condition. Specifically, participants were asked to report an experience in which they had felt this particular emotion through an Autobiographical Emotional Memory Task (AEMT) (as in Smith & Ellsworth, 1985). Following this experimental manipulation, the experimental utility (a small chocolate bar) was distributed and they were again encouraged to consume. Subsequently, they were asked to rate how much they liked and how much they would like the utility on the fifth day. Depth of processing was assessed with four items (α=0.77), adjusted from Griffin et al. (2002). Specifically, these items measured the heuristic processing performed during the prediction process. Participants were contacted again on each of the remaining four days and were asked to consume the utility and to complete a short questionnaire (comprising ratings of the consumption experience and of the predicted utility on the fifth day). The results reported here involve only the data obtained on the first and final day of the experiment, and the forecasting error was estimated as the difference between the experienced utility of the last day and the predicted utility of the first day. In line with hypothesis H1, emotional certainty had a significant main effect on predicted utility (F = 6.18, p = 0.002, partial eta squared = 0.08). Specifically, predicted utility in the low emotional certainty condition was higher (M = 2.69, SD = 1.09), compared to that of the high certainty condition (M = 0.78, SD = 1.66). There was no significant interaction effect between certainty and valence. These findings provide further support for our H1 and indicate that emotional certainty influences utility prediction irrespective of the valence of incidental emotions. Moreover, a significant main effect of certainty on forecasting error was observed (F = 4.16, p = 0.045, partial eta squared = 0.06). Forecasting error was lower in the low certainty condition (M = 0.59, SD = 1.28) compared to the high certainty condition (M = 2.19, SD = 1.48). There was no significant interaction effect. Moreover, a mediation analysis revealed that heuristic processing mediated the effect of certainty on forecasting error (p**<0.05). Experiment 3 The previous two experiments indicate that the effects of incidental emotional states on predicted utility and forecasting error may be due to the certainty-appraisal dimension of these emotional states. A possible criticism and an inherent limitation of Experiments 1 and 2 might lie on the possibility that these effects are not independent of the other appraisal dimensions. This is related to a key methodological issue. In Experiments 1 and 2, the induced emotions were different in terms of certainty or uncertainty, but these emotions might have differed in other ways and across other appraisal dimensions as well. To eliminate this possibility and to strengthen our argument, we employ here a manipulation of the certainty appraisal of the same emotion. We therefore compare predicted utility and forecasting error in the same emotional state under conditions of low and high certainty. In Experiments 1 and 2 the emotions induced are strong representatives of each side of the certainty appraisal dimension. However, emotions located in the middle of this dimension provide an interesting opportunity since they might allow us to compare their effects when they are associated with lower or higher levels of certainty. In this experiment we have chosen to focus on the emotional state of sadness. Sadness was selected because it is near the middle of the certainty-uncertainty dimension (Smith & Ellsworth, 1985). Similar manipulations of sadness have been reported in the literature (Tiedens & Linton, 2001). Sixty postgraduate students were randomly assigned to a low vs. high certainty sadness condition. High certainty participants were asked to recall and report an experience or event in which they had felt high certainty sadness (i.e. during which they understood what was happening and could predict what was going to happen next), through an Autobiographical Emotional Memory Task (AEMT) as in Experiment 2. Similarly, low certainty participants were asked to recall and report an event or experience that had generated low certainty sadness. Following the experimental manipulation, the experimental utility (a small chocolate bar) was served. Participants were again encouraged to consume some of it and were asked to complete 13-point ratings of how much they liked it and how much they would like it in the future occasion (a week later). Eight items (α=0.81), adapted from Griffin et al. (2002), measured the heuristic processing performed during the prediction process. Participants also completed ten items adjusted from PANAS questionnaire (Watson et al., 1988). A week later, participants consumed the utility and completed a short questionnaire. The results revealed a significant main effect of certainty on the predicted utility (F = 4.00, p = 0.05, partial eta squared = 0.06). Predicted utility in the low certainty sadness condition was higher (M = 4.21, SD = 1.55) compared to that of the high certainty condition (M = 3.35, SD = 1.78). A significant main effect of certainty on forecasting error was also observed (F = 5.04, p = 0.03, partial eta squared = 0.10). Forecasting error in the low certainty condition (M = -0.10, SD = 1.65) was lower compared to that of the high certainty condition (M = 1.02, SD = 1.81). A mediation analysis revealed that heuristic processing again mediated the effect of certainty on forecasting error (p**<0.05). Conclusion The contribution of this research is mostly highlighted by the counter-intuitive findings that lower certainty emotions lead to judgment with higher accuracy, as well as to an overprediction of utilities, related to their certainty counterparts. Therefore, the current findings provide support for the proposed Uncertainty-Prediction dual Asymmetry (UPA) hypothesis. Future research needs to corroborate these findings, to clarify the mechanisms underlying the observed asymmetry and to identify boundary conditions.

Despite the accident rate for fishing vessels accounts for 70% of all maritime accidents, few studies on such accidents have been done and most of the them mainly focus on causes and mitigation policies to reduce that accident rate. Thus, this risk analysis on sea accidents is the first to be performed for the successful and efficient implementation of accident reducing measures. In risk analysis, risk is calculated based on the combination of frequency and the consequence of an accident, and is usually expressed as a single number. However, there exists uncertainty in the risk calculation process if one uses a limited number of data for analysis. Therefore, in the study we propose a probabilistic simulation method to forecast risk not as a single number, but in a range of possible risk values. For the capability of the proposed method, using the criteria with the ALARP region, we show the possible risk values spanning across the different risk regions, whereas the single risk value calculated from the existing method lies in one of the risk regions. Therefore, a decision maker could employ appropriate risk mitigation options to handle the risks lying in different regions. For this study, we used fishing vessel accident data from 1988 to 2016.

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.

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.

Intermittent demand is a demand with a pattern in which zero demands occur frequently and non-zero demands occur sporadically. This type of demand mainly appears in spare parts with very low demand. Croston’s method, which is an initiative intermittent demand forecasting method, estimates the average demand by separately estimating the size of non-zero demands and the interval between non-zero demands. Such smoothing type of forecasting methods can be suitable for mid-term or long-term demand forecasting because those provides the same demand forecasts during the forecasting horizon. However, the smoothing type of forecasting methods aims at short-term forecasting, so the estimated average forecast is a factor to decrease accuracy. In this paper, we propose a forecasting method to improve short-term accuracy by improving Croston’s method for intermittent demand forecasting. The proposed forecasting method estimates both the non-zero demand size and the zero demands’ interval separately, as in Croston’s method, but the forecast at a future period adjusted by binomial weight according to occurrence probability. This serves to improve the accuracy of short-term forecasts. In this paper, we first prove the unbiasedness of the proposed method as an important attribute in forecasting. The performance of the proposed method is compared with those of five existing forecasting methods via eight evaluation criteria. The simulation results show that the proposed forecasting method is superior to other methods in terms of all evaluation criteria in short-term forecasting regardless of average size and dispersion parameter of demands. However, the larger the average demand size and dispersion are, that is, the closer to continuous demand, the less the performance gap with other forecasting methods.

Tomato leaves were inoculated with 1x104 spores · mL-1 and placed in an acryl box at 10, 15, 20, 25, and 30oC for 24 h. Ten days after inoculation, the incidence of late blight appeared as a typical symptom in 6 hrs treatment of leaf wet duration when the temperature is between 15 and 20oC at that time. The incidence of disease was 26% and 41% at 10oC and 25oC treatment although the disease did not occur even after treatment at 30oC for 16 h, respectively. The most important factors in the incidence of Late blight were leaf wet duration and temperature. Optimum growth temperature of tomato is from 15 to 25oC, thus the management of leaf wet duration is better than control by temperature to prevent the incidence of Late blight. After inoculation, the symptoms of Late blight occurred in 5 days, therefore the latency period was estimated to be 5 days. The incidence rate of Late blight was the highest at 15 and 20oC. At the time of chemicals application, when Fluopicolide 5%+Propamocarb hydrochloride 25% was applied at 12 h of leaf wet duration, the control effect was the highest as 95% at 36 h but decreased by 70% when treated after 48 h. On the other hand Cymoxanil 12% + Famoxadone 9% was applied at 18 h of leaf wet duration, the control effect was the highest as 95% at 36 h but decreased by 70% after 48 h as similar as Fluopicolide 5% +Propamocarb hydrochloride 50% treatments. In the application of Dimethomorph 15% +Dithianon 30%, the control effect was more or less low as 80% at 20 h of leaf wet duration and was decreased to 60% at 48 h.

Recent development in science and technology has modernized the weapon system of ROKN (Republic Of Korea Navy). Although the cost of purchasing, operating and maintaining the cutting-edge weapon systems has been increased significantly, the national defense expenditure is under a tight budget constraint. In order to maintain the availability of ships with low cost, we need accurate demand forecasts for spare parts. We attempted to find consumption pattern using data mining techniques. First we gathered a large amount of component consumption data through the DELIIS (Defense Logistics Intergrated Information System). Through data collection, we obtained 42 variables such as annual consumption quantity , ASL selection quantity, order-relase ratio. The objective variable is the quantity of spare parts purchased in f-year and MSE (Mean squared error) is used as the predictive power measure. To construct an optimal demand forecasting model, regression tree model, randomforest model, neural network model, and linear regression model were used as data mining techniques. The open software R was used for model construction. The results show that randomforest model is the best value of MSE. The important variables utilized in all models are consumption quantity, ASL selection quantity and order-release rate. The data related to the demand forecast of spare parts in the DELIIS was collected and the demand for the spare parts was estimated by using the data mining technique. Our approach shows improved performance in demand forecasting with higher accuracy then previous work. Also data mining can be used to identify variables that are related to demand forecasting.

This research studies on the demand forecasting for service parts considering parts life cycle, that gets relatively less attentions in the field of forecasting. Our goal is to develop forecasting method robust across many situations, not necessarily optimal for a limited number of specific situations. For this purpose, we first extensively analyze the drawbacks of the existing forecasting methods, then we propose the new demand forecasting method by using these findings and reinforcement leaning technique. Using simulation experiments, we proved that the proposed forecasting method is better than the existing methods under various experimental environments.

Many industrial accidents have occurred continuously in the manufacturing industries, construction industries, and service industries of Korea. Fatal accidents have occurred most frequently in the construction industries of Korea. Especially, the trend analysis of the accident rate and fatal accident rate is very important in order to prevent industrial accidents in the construction industries systematically. This paper considers forecasting of the accident rate and fatal accident rate with static and dynamic time series analysis methods in the construction industries. Therefore, this paper describes the optimal accident rate and fatal accident rate by minimization of the sum of square errors (SSE) among regression analysis method (RAM), exponential smoothing method (ESM), double exponential smoothing method (DESM), auto-regressive integrated moving average (ARIMA) model, proposed analytic function model (PAFM), and kalman filtering model (KFM) with existing accident data in construction industries. In this paper, microsoft foundation class (MFC) soft of Visual Studio 2008 was used to predict the accident rate and fatal accident rate. Zero Accident Program developed in this paper is defined as the predicted accident rate and fatal accident rate, the zero accident target time, and the zero accident time based on the achievement probability calculated rationally and practically. The minimum value for minimizing SSE in the construction industries was found in 0.1666 and 1.4579 in the accident rate and fatal accident rate, respectively. Accordingly, RAM and ARIMA model are ideally applied in the accident rate and fatal accident rate, respectively. Finally, the trend analysis of this paper provides decisive information in order to prevent industrial accidents in construction industries very systematically.

In this research, we propose efficient demand forecasting scheme for intermittent demand. For this purpose, we first extensively analyze the drawbacks of the existing forecasting methods such as Croston method and Syntetos-Boylan approximation, then using these findings we propose the new demand forecasting method. Our goal is to develop forecasting method robust across many situations, not necessarily optimal for a limited number of specific situations. For this end, we adopt combining forecasting method that utilizes unbiased forecasting methods such as simple exponential smoothing and simple moving average. Various simulation results show that the proposed forecasting method performed better than the existing forecasting methods.

Customers’ final purchase decisions for electronic products are understandably influenced by previous experiences, marketing messages such as price and promotion, and opinions from other consumers (Simonson and Rosen 2014). In particular, millions of product reviews are posted daily on online review boards or social media represent aggregate consumer preference data (Decker and Trusov 2010). Past studies analyzing online reviews or word-of-mouth (WOM) have focused more on the quantitative dimension of volume of WOM (or “how much people say”), but less on qualitative dimension of valence of WOM (or “what people say”) (Gopinath, Thomas, and Krishnamurthi 2014). However, recent studies have analyzed disaggregate-level UGC by performing text mining in addition to a general analysis of volume and valence of OUGC. Onishi and Manchanda (2012) investigate the relationship between movie sales and both TV advertising and blogs. Although the authors find that the volume and the valence of OUGC (i.e., blogs) are predictive of market outcomes, they retain only certain words (i.e., advertising, award, interesting, and viewed) that consumers would find useful, therefore having general predictive power for market outcomes. Gopinath, Thomas, and Krishnamurthi (2014) address the relationship between the content of online WOM, advertising, and brand performance of cell phones and find that the volume of OUGC does not have significant impact on sales, but only the valence of recommendation UGC has a direct impact. Liu, Singh, and Srinivasan (2015) find that both the volume and sentiments of Tweets do not outperform the information content of Tweets in predicting TV series ratings. Although these three papers have investigated the importance of qualitative UGC through text mining techniques, such studies have not accounted for the detailed dimensions of specific contents. For example, Onishi and Manchanda (2012) use only 4 words out of top 30 frequently cited words for their analysis, and Gopinath, Thomas, and Krishnamurthi (2014) classify the OUGC into three disaggregated dimensions (i.e., attribute, emotion, and recommendation) without further classifications of subcategories and valence of positivity and negativity. Liu, Singh, and Srinivasan (2015) mainly focus on positive and negative Tweet contents about TV shows, lacking further classification of functional and emotional dimensions. In contrast to these studies, this study aims to examine in-depth multidimensional aspects of the content of online reviews, i.e., qualitative UGC, and their impacts on product sales. In this process, we develop defensible measurements of UGC by executing a comprehensive empirical text analysis and evaluate the impact of measures of qualitative UGC relative to volume measure of quantitative UGC. Specifically, we analyze a large data set of UGC on the 350 most talked-about smartphone games from seven different genres (e.g., action, arcade, shooting, puzzle, role playing, simulation, and sports) over a 30 month period, August 2010 to February 2013. We utilize a theoretical framework that classifies qualitative UGC into two major perceptions of functional and emotional dimensions. Prior studies show that perceptions of both functional (cognitive) and emotional (affective) dimensions should be considered to investigate their effects on perceived user satisfaction (Coursaris and van Osch 2015) and online shopping behavior (Van der Heijden 2004). It is evident that both functional and emotional UGC influence consumers to purchase a focal product (Lovett, Peres, and Shachar 2013). The functional UGC relates to the positive and negative attributes and beliefs about a product, and the emotional UGC pertains to the feelings and emotions in response to product experience. As an example, consider one innovative car-racing mobile game which, although expensive, has 3D graphics and high level of complexity. After playing this game, consumers may express their feedback on this game online by describing it as well-made, unique, but sometimes fearful (because a high bill charge is expected from excessive playing time), and addictive (because they like the game too much to stop playing it). This type of online reviews contains different types of UGC: functional (e.g., quality, innovativeness) and emotional (e.g., fear). Another layer of our analysis involves the heterogeneity of impact on product sales across different qualitative UGCs. Specifically, we consider the effects of functional UGC on product sales across emotional contexts such as anger and happiness, in other words, a simultaneous association between functional UGC and emotional UGC. For example, although a consumer may be attracted by some reviews on the high quality graphics of a mobile game (functional UGC), she may hesitate to purchase this product because other reviews express their fear about high cost of purchasing virtual goods (emotional UGC). Accordingly, we expect the functional UGC’s effects on sales to be moderated (amplified or reduced) by emotional UGC. We accommodate such interaction effects in both aggregate and disaggregate models. To the best of our knowledge, this study is the first to empirically identify two dimensions of qualitative UGC (functional and emotional), and shed light on the effects of multidimensional UGC categories on sales. Our findings on the influence of qualitative UGC on product sales are quite different from the prevailing view that firms should pay attention more to the volume of UGC (Chevalier and Mayzlin 2006; Liu 2006) but little to the valence of UGC (Duan, Gu, and Whinston 2008; Godes and Mayzlin 2004; Liu 2006). Rather, our research is in line with recent three papers (Gopinath, Thomas, and Krishnamurthi 2014; Liu, Singh, and Srinivasan 2015; Onishi and Manchanda 2012) in terms of the importance of considering specific contents from a vast amount of text data. However, our paper provides two key contributions. First, we show that specific categories of qualitative online UGC such as functional and emotional variables can be used to predict product sales; this result will be of a high managerial relevance. Especially, traditional methods that use simple metrics such as volume and valence of UGC are less accurate than our method that employs a sophisticated, multidimensional content analysis. Second, the results offer guidance to firms in determining which specific UGC (quantitative or qualitative; functional or emotional; under what contexts) they should focus on for increasing the efficiency of their online marketing activities. Utilizing a large dataset of online reviews on 350 mobile games consisting of four million postings generated for thirty months, the authors identified 76 representative words to describe the functional and emotional UGC using text analysis and word classification. We combined the resulting UGC volumes with weekly sales, resulting in 1,835 observations for analysis with hierarchical Bayesian methods. We find that functional UGC includes 54 representative words to describe various levels of product quality, product innovativeness, price acceptability, and product simplicity, and emotional UGC includes 22 words to express anger, fear, shame, love, contentment, and happiness. The results show that the volume and valence of aggregated functional UGC and the share of aggregated emotional UGC have the positive effects on sales. The volume and valence of functional UGC subcategories have mixed effects on sales and the link is moderated by the share of emotional UGC subcategories. These results are in contrast to those in the literature. Further, a sales forecasting model which includes 13 variables of UGC subcategories shows the best predictive validity. The authors discuss the implications of these results for online marketers.

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.