• The Proceedings of the Korean Institute of Illuminating and Electrical Installation Engineers
• /
• v.11 no.5
• /
• pp.62-66
• /
• 1997

This paper is presented to short-term load forecast algorithm using weekday change ratio. The week periodicity was excluded from weekday change ratio. That was composed with the power demand forecast term of five and multiple regression model of the three form. The precision was good with 2.8[%]. Also the power demand of special day(weekend) of completely difficult forecast case of using the multiple regression model was able to forecast at this paper. Therefore, the forecast precision was enhanced and the reliable forecast model was constructed.

• Journal of Information Processing Systems
• /
• v.14 no.6
• /
• pp.1385-1397
• /
• 2018

There are many factors that affect the wind speed. In addition, the randomness of wind speed also leads to low prediction accuracy for wind speed. According to this situation, this paper constructs the short-time forecasting model based on the least squares support vector machines (LSSVM) to forecast the wind speed. The basis of the model used in this paper is support vector regression (SVR), which is used to calculate the regression relationships between the historical data and forecasting data of wind speed. In order to improve the forecast precision, historical data is clustered by cluster analysis so that the historical data whose changing trend is similar with the forecasting data can be filtered out. The filtered historical data is used as the training samples for SVR and the parameters would be optimized by particle swarm optimization (PSO). The forecasting model is tested by actual data and the forecast precision is more accurate than the industry standards. The results prove the feasibility and reliability of the model.

• Proceedings of the Korean Society of Precision Engineering Conference
• /
• 2008.06a
• /
• pp.755-756
• /
• 2008

• Proceedings of the Korean Society of Precision Engineering Conference
• /
• 1994.10a
• /
• pp.866-871
• /
• 1994

B-spline curves and surfaces are effective solutions for design and modelling of the freeform models. The control methods of these are using with control points, knot vectors and weight of NURBS. Using control point is easy and resonable for representation of general models. But the movement of control points bring out the reformation of original convex hull. The B-splines with nonuniform knot vector provide good result of the shape modification without convex hull reforming. B-splines are constructed with control points and basis functions. Nonuniform knot vectors effect on the basis functions. And the blending curves describe the prorities of knot vectors. Applying of these, users will forecast of the reformed curves after modifying controllabler primitives.

• Journal of Digital Convergence
• /
• v.17 no.4
• /
• pp.107-114
• /
• 2019

This study analyzes the effect of the accuracy of future management performance, which managers voluntarily announce in the previous year's disclosure, on managers compensation. In the case of a company that disclosed the bad news in the previous year, the ability to predict uncertain future will be more important, and expects executives with better predictability to receive more compensation. The results of this study show that there is a significant negative(-) relationship between the accuracy of the manager's earnings forecast and the performance - compensation of the firms that disclosed the bad news in the previous year. The accuracy of the manager's disclosure is important, and it is confirmed that the manager's compensation increases as the incentive of the manager's effort to reduce future uncertainty. The results of this study are as follows: there is a positive relationship between the managerial performance and the managerial competence of managers. It is important to note that there is a difference and that we have identified additional determinants of the manager compensation contract.

• Journal of Environmental Science International
• /
• v.27 no.7
• /
• pp.531-541
• /
• 2018

Road freezing caused by snowfall during wintertime causes traffic congestion and many accidents. To prevent such problems, we developed, in this study, a system to predict road freezing based on weather forecast data and the freezing generation modules. The weather forecast data were obtained from a high-resolution model with 1 km resolution for Jeju Island from 00:00 KST on December 1, 2017, to 23:00 KST on February 28, 2018. The results of the weather forecast data show that index of agreement (IOA) temperature was higher than 0.85 at all points, and that for wind speed was higher than 0.7 except in Seogwipo city. In order to evaluate the results of the freezing predictions, we used model evaluation metrics obtained from a confusion matrix. These metrics revealed that, the Imacho module showed good performance in precision and accuracy and that the Karlsson module showed good performance in specificity and FP rate. In particular, Cohen's kappa value was shown to be excellent for both modules, demonstrating that the algorithm is reliable. The superiority of both the modules shows that the new system can prevent traffic problems related to road freezing in the Jeju area during wintertime.

• Proceedings of the Korean Society of Precision Engineering Conference
• /
• 2005.06a
• /
• pp.1893-1896
• /
• 2005

Cutting force and face roughness have the largest influence on precision of a structure or processing efficiency in cutting processing. Thus cutting force model and face roughness model are necessary for this interpretation. In this paper, tool path model and face roughness model which consider the blade number of a tool and a revolution speed of tool and workpiece in the worm processing using side milling cutter are presented. This model was used to forcast the cusp. Experimental results show that the predicted cusp coincides with experimental one.

• Proceedings of the Korean Society of Precision Engineering Conference
• /
• 2005.10a
• /
• pp.777-780
• /
• 2005

The global consumption of aspheric surfaces will expand rapidly on the Electronics and Optical Components Information and Communications, Aerospace and Defense, and Medical optics markets etc. We must research on market, technology forecast and analysis of aspheric surfaces that is a principle step of ultra precision machine technology with a base one of optical elements. Especially, F-theta lens is one of the important parts in LSU(Laser scanning unit) because it affects on the optical performance of LSU dominantly. The core is most of important to produce plastic F-theta lens by plastic injection molding method, which is necessary to get the ultra-precision aspheric and non-axisymmetric machine processing technology.

• Journal of Internet Computing and Services
• /
• v.20 no.1
• /
• pp.11-16
• /
• 2019

Wireless sensor network is important for precision farming to monitor the growth environment of crops in open field, but radio signals are susceptible to different types of interference such as weather and physical objects. This paper designs and implements an environmental monitoring and weather forecast acquisition systems for smart field irrigation based on LoRa(Long Range) and then applies it to a test bed. And we evaluate the network reliability in terms of packet transmission success rate by comparing its condition on two criteria; the existence of obstacle or rain. The results show that much rain falls can affect on packet loss in LoRa field networks with obstacles.

• Journal of Digital Convergence
• /
• v.16 no.10
• /
• pp.125-132
• /
• 2018

The purpose of this study is to analyze the effect of managerial predictive accuracy on managerial performance-compensation. In this study, we compared managerial performance with managerial performance, And to analyze the relationship between manager compensation and manager compensation using managerial profit prediction accuracy. As a result of this study, there is a significant positive relationship between profit prediction accuracy and manager compensation, which can be interpreted as a result of manager's ability to compensate manager's ability to predict the future well. In this paper, we propose a new methodology that can be used to analyze the effects of managerial compensation on managerial compensation. This is because there is a difference in that it is proved to be a factor. Therefore, it is important to note that the prediction of the future of the company also identifies the additional determinants that affect manager compensation contracts with the key managerial capabilities.