• Journal of the Korean Solar Energy Society
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• v.33 no.6
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• pp.62-69
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• 2013

In this paper, Korea Institute of Energy Research, building integrated renewable energy monitoring system that utilizes solar power generation forecast data forecast model is proposed. Renewable energy integration of real-time monitoring system based on monitoring data were building a database and the database of the weather conditions and to study the correlation structure was tailoring. The weather forecast cloud cover data, generation data, and solar radiation data, a data mining and time series analysis using the method developed models to forecast solar power. The development of solar power in order to forecast model of weather forecast data it is important to secure. To this end, in three hours, including a three-day forecast today Meteorological data were used from the KMA(korea Meteorological Administration) site offers. In order to verify the accuracy of the predicted solar circle for each prediction and the actual environment can be applied to generation and were analyzed.

• Journal of the Korean Society of Safety
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• v.28 no.3
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• pp.114-117
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• 2013

The purpose of this study is to empirically investigate accuracy of paper-pencil test used in surveying control-display stereotype. For doing this, three paper-pencil tests dealing with stereotype for control-burner relationship of four-stove gas range, in which three different gas range images were provided, were performed and the results were compared with those of existing studies. The result of the paper-pencil test using simple image composed of line and circle was different from that of the real model simulation, while the results of the other two tests and a previous study providing more realistic images were the same as that of the real model simulation. Furthermore, the proportion of responses coinciding with the real model simulation increased as images used became closer to real range. It is concluded that the paper-pencil tests well designed using realistic images may produce the same stereotype as the real model simulation.

• Structural Engineering and Mechanics
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• v.81 no.5
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• pp.591-606
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• 2022

When the friction pendulum system and shear keys work together to resist the ground motion, which inclined inputs (non 45°) to the bridge structure, the shear keys in XY direction will be sheared asynchronously, endowed the friction pendulum system with a violent curvilinear motion on the sliding surface during earthquakes. In view of this situation, firstly, this paper abandons the equivalent linearization model of friction and constructs a Spring-Coulomb friction plane isolation system with XY shear keys, and then makes a detailed mechanical analysis of the movement process of friction pendulum system, next, this paper establishes the mathematical model of structural time history response calculation by using the step-by-step integration method, finally, it compiles the corresponding computer program to realize the numerical calculation. The results show that the calculation method in this paper takes advantage of the characteristic that the friction force is always µmg, and creatively uses the "circle making method" to express the change process of the friction force and resultant force of the friction pendulum system in any calculation time step, which can effectively solve the temporal nonlinear action of the plane friction; Compared with the response obtained by the calculation method in this paper, the peak values of acceleration response and displacement response calculated by the unidirectional calculation model, which used in the traditional research of the friction pendulum system, are smaller, so the unidirectional calculation model is not safe.

• Journal of the Korean Society of Safety
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• v.32 no.4
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• pp.107-113
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• 2017

This paper deals with the traffic factors related to the collisions of circular intersections. The purpose of this study is to develop traffic accident models by type of collision based on land use. In pursuing the above, the traffic accident data from 2010 to 2014 were collected from the "Traffic Accident Analysis System (TAAS)" data set of the Road Traffic Authority. A multiple regression model was utilized in this study to develop the traffic accident models by type of collision. 17 explanatory variables such as geometry and traffic volume factors were used. The main results are as follows. First, the null hypothesis that the type of land use does not affect the number of accidents by type of collision is rejected. Second, 10 accident models by type of collision based on land use are developed, which are all statistically significant. Finally, the ADT, inscribed circle diameter, bicycle lane, area of central island, number of speed hump, circulatory roadway width, splitter island, area of circulatory roadway, mean number of entry lane and mean width of entry lane are analyzed to see how they affect accident by type of accident based on land use.

• Journal of the Korean Society for Precision Engineering
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• v.15 no.5
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• pp.85-92
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• 1998

This present paper describes a mathematical model of profile shifted elliptical gears, and this model is based on the concepts of envelope theory and conjugate geometry between the blank and the straight-sided rack cutter. The geometric model of the rack cutter includes working regions generating involute curves and fillets for trocoidal curves, and furthermore the addendum modified coeff. is considered for avoiding undercutting. The addendum modified coeff. is changed linearly along with pitch curves and must be the same absolute value at both major semi-axis and minor semi-axis. If undercutting is at all pronounced, the undercut tooth not only are weakened in strength, but lose a small portion of the involute adjacent to the base circle, then this loss of involute may cause a serious reduction in the length of contact. A very effective method of avoiding undercutting is to use the so-called profile shifted gearing. Non-undercutting condition is examined with the change of eccentricity and addendum modified coeff. in elliptical gears and then the minimum number of tooth is proposed not to gernerate undercutting phenomenon.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 1997.04a
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• pp.572-577
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• 1997

This present paper describes a mathematical model of profile elliptical gears, and this model is based on the concepts of envelop theory and conjugate geometry between the blank and the straight-sided rack cutter. The geometric model of the rack cutter includes working regions generating involute curves andd fillets for trocoidal curves, and furthermore the addendum modified coeff,is considered for avoiding undercutting. The addendum modified coeff, is changed linearly along with pitch curves and must be the must be the same absolute value at both major semi-axis and minor semi-axis. If undercutting is at all pronounced, the undercut tooth not only are weakened in strength, but lose a small portion of the involute adjacent to the base circle, then this loss of involute may ncause a serios reduction in the length of contact. A very effective method of avoiding undercutting is to use the so-called profile shifted gearing. Non-undercutting conditon is examined with the change of eccentricity and addendum modefied coeff. in elliptical gears and then the minimum number of tooth is proposed not to gernerate undercutting phenomenon.

• Journal of the Korean Society of Food Culture
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• v.26 no.3
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• pp.211-219
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• 2011

To examine the key success factors for long-lasting restaurants, we visited 10 restaurants with 30 or more than 30 years of tradition, located in Seoul and Gyeonggi-do districts, to research these restaurant menus and customer characteristics by observation and interview. The results were analyzed using descriptive statistics. The outstanding feature noted was that each and every restaurant had its own simple and specialized menu. We found that this feature created a virtuous circle that reinforced itself through a positive feedback loop. The simple and specialized menu increased both the cooking efficiency and food quality while it reduced both food and labor costs, this enabled the customers to eat at an affordable price and have generous servings. This lead to customer satisfaction and revisits to the restaurant, which triggered word-of-mouth referral and expansion of their customer base. This in turn created higher operating profit margins that could be reinvested in the business. The secret recipes for cooking, invented by their founders, were passed on from generation to generation. Their customer base included customers of all ages from children to senior people. And their regular customers consisted of neighboring office workers and families traveling from a long distance. We hope that our findings on long-lasting restaurants, especially of the virtuous cycle created due to the simple and specialized menus with secret recipes, will contribute to the development of Korean style long-lasting restaurant model.

• Journal of the Korean Society for Precision Engineering
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• v.13 no.3
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• pp.26-30
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• 1996

The successful development of the automobile industry in Korea is the firstfruit of the epochmaking automobile policy in 1973: Top-Down mass production of Korean model cars. In Top-Down system, indigenous model, which is the most important and difficult part of the automobile industry, is devised first, followed by the mass production of the major parts, such as bodies, engines, etc. This system is in contrast to the prevailing Bottom-up system in the third-world, which assembles automobiles by gradually adding up simple domestic parts. The Government, faced with a vicious circle of depen- dence on assembly of foreign cars, high prices, small demand and low production, decided it was time to move to the mass production of the indigenous models. It was hoped that the efficiencies of low cost Korean models would be epochally improved by overcoming the sway of foreign models and by strengthening the production capabilities of the main parts. In contrast to these develop- ment planning, assembled vehicles numbered only 26,300 units in 1973. In the year of 1995, the total number of automobile production have already passed 2,534,000. As steady growth in worldwide demand is forecast, Korea will able to play a major role as an important automobile maker of the next century.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2022.05a
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• pp.76-77
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• 2022

In this paper, we propose a method to stabilize the 3D pose estimation result of a 3D volumetric data sequence by matching the pose estimation results from multi-view. Draw a circle centered on the volumetric model and project the model from the viewpoint at regular intervals. After performing Openpose 2D pose estimation on the projected 2D image, the 2D joint is matched to localize the 3D joint position. The tremor of 3D joints sequence according to the angular spacing was quantified and expressed in graphs, and the minimum conditions for stable results are suggested.

• Journal of Ocean Engineering and Technology
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• v.37 no.5
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• pp.198-204
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• 2023

In response to the complexity and time demands of conventional methods for estimating the hydrodynamic coefficients, this study aims to revolutionize ship maneuvering analysis by utilizing automatic identification system (AIS) data and the Support Vector Regression (SVR) algorithm. The AIS data were collected and processed to remove outliers and impute missing values. The rate of turn (ROT), speed over ground (SOG), course over ground (COG) and heading (HDG) in AIS data were used to calculate the rudder angle and ship velocity components, which were then used as training data for a regression model. The accuracy and efficiency of the algorithm were validated by comparing SVR-based estimated hydrodynamic coefficients and the original hydrodynamic coefficients of the Mariner class vessel. The validated SVR algorithm was then applied to estimate the hydrodynamic coefficients for real ships using AIS data. The turning circle test wassimulated from calculated hydrodynamic coefficients and compared with the AIS data. The research results demonstrate the effectiveness of the SVR model in accurately estimating the hydrodynamic coefficients from the AIS data. In conclusion, this study proposes the viability of employing SVR model and AIS data for accurately estimating the hydrodynamic coefficients. It offers a practical approach to ship maneuvering prediction and control in the maritime industry.