• The Transactions of the Korean Institute of Electrical Engineers A
• /
• v.50 no.8
• /
• pp.351-358
• /
• 2001

This paper deals with the PSS modeling of Ulchin N/P #1 as well as the generator and excitation system modeling by utilizing the recorded data from AVR step test, which has been performed by entering small voltage signal into the AVR summing point. In addition to it. two recorded results obtained from the AVR step test with PSS sunning and without PSS running have not only been compared each other on the time domain, but also they heve been analyzed with FFT analysis on the frequency domain; thus, the desirable effects of running PSS in Ulchin N/P #1 on power system have been explicitly confirmed. Finally, the derived PSS model parameters lead to good matches between simulation results and recorded data.

• Journal of Korea Technology Innovation Society
• /
• v.7 no.2
• /
• pp.351-372
• /
• 2004

This paper examines the change of innovation practices in the Korean industry which is entering into the 'post catching-up regime'. In catching-up regime, the technological loaming practices of Korean firms could be characterized as the assimilation and improvement of foreign technologies through crisis construction and time pressure. Crisis construction and time pressure were the important factors enhancing the intensity of technological teaming and shaping the way of doing imitative innovation. But the innovation patterns of firm are changing. The new ways of doing innovation are emerging in Korean mobile phone industry which is becoming a world leader： the emphasis on the importance of technological planning, the enhancement of collaborative networks among related firms, the toleration on the failure and the effort to acquire core technologies. Though Korean firms have not developed enough capabilities to create basic core technologies, they can develop their competitiveness through creative combination of technologies and are approaching the world frontier.

• Magazine of the Korean Society of Agricultural Engineers
• /
• v.36 no.3
• /
• pp.144-154
• /
• 1994

An efficient tidal model, TIDE which is an iterative type, nonlinear finite element model has developed for the analysis of the tidal movement in the coastal area which is characterized by irregular boundaries and bottom topography. Traditional time domain finite element models have been in difficulties with requirement for high eddy viscosity coefficients and small time steps to insure numerical instability. These problems are overcome by operating in the frequency domain with an elaborate grid system by combining the triangular and quadrilateral shape grids. Furthermore, in order to handle non-linearity which will be more significant in the shallow region, an iterative scheme with least square error minimization algorithm has been implemented in the model. The results of TIDE model are agreed with the analytical solutions in a rectangular channel under the condition of tidal waves entering the channel closed at one end.

• Journal of Korean Society of Industrial and Systems Engineering
• /
• v.12 no.19
• /
• pp.73-78
• /
• 1989

This paper concerns the production model that the Automatic Guided Vehicles(AGVs) is used as transporters in assembly line. The model suggests that assembly parts may inter the beginning of the line in multiple units instead entering one unit at a time. Costs are occured in proportion to the number of vehicle on the line and job flow time. Here, the objective of this model is to determine the number of vehicle to minimize the total cost for M products production. Theoretical results are proved which lead to the development of algorithm for solution search. The solution search procedure is illustrated by a numerical example.

• Journal of Korea Multimedia Society
• /
• v.25 no.2
• /
• pp.411-420
• /
• 2022

Entering the digital cinema era, movies and games are remediating each other. The shots of digital movies are being transformed into realistic content through digital Moving long-take shots that transcend time and space and move smoothly. At this time, the digital Moving long take shot that continuously captures the space in all directions without an external screen induces a game experience. In addition, the camera that constantly accompanies the person enhances the sense of immersion in the game in a way similar to the point of view of the game. While various immersive device contents represented by VR, AR and XR are emerging, the advent of <1917> suggests significant implications for post-cinema in that it creates a game experience while maintaining the traditional screen environment and cinematic paradigm.

• Journal of Korea Society of Industrial Information Systems
• /
• v.16 no.3
• /
• pp.57-63
• /
• 2011

The internet is currently becoming popularized and generalized in our daily life. Recently, a lot of hacking tools have appeared on the internet. And damage size and seriousness the measurement is impossible. The password security protects oneself and information is the tool which is essential for from the internet, if this emphasizes no matter how, does not go to extremes. If applies a encryption, a 7 character password is sufficient, so long as attackers don't pick easily guessed values. In this paper, entering password using the virtual keyboard, I propose a new and improved one time password algorithm using information a part of ID and final approval time.

• Journal of Korean Society of Industrial and Systems Engineering
• /
• v.33 no.2
• /
• pp.33-38
• /
• 2010

To survive head-to-head competition, we should keep our labor productivities above those of other nations. However, our labor productivities are low compared to those of the developed countries. It is the well-known fact that we make up for the productivities with long work hours. Entering the line of developed nations safely and enjoying well-being age freely, we need to achieve high labor productivities without sacrificing work hours. What would be a fine solution? Back to the basics! Although it is important to enforce R&D on high-tech products, we should have so-called bluebird philosophy, being faithful to the basics and trying to find solutions at a stone's throw. Basics of basics may be unceasing improvement, establishing reasonable standard times, and maintaining them. To support going back to the basics, this thesis proposes VITAMAX, a motion and time study software. As VITAMAX stands for "Visual Improvement and Time Analysis for Maximizing Profits", it provides a simple and powerful visual tool which is useful for improving manual works and determining standard times. Since VITAMAX is based on the Microsoft Excel and VBA, it is very cost-effective and easy to use. VITAMAX may contribute to the profit increase of manufacturing companies, especially for the small and medium-sized enterprise.

• The Journal of the Institute of Internet, Broadcasting and Communication
• /
• v.9 no.4
• /
• pp.25-31
• /
• 2009

In this paper, the implementation of a production control system based on RFID has been studied in order to obtain an exact Cost Center data such as the name of workers included a process of work and a time period to finish the process. The cost center of a worker will be correctly obtained by checking the work time using RFID tag data and by transmitting the data to a server of ERP or POP system. And also warming up time, cleaning time, power failure, and out of order sign will be checked and calculated using the data stored in RFID tags attached in workers and machine facilities. Therefore, exact Cost Center data will be obtained by the production control system with touch screens entering the data according to the situation in real time.

• Journal of the Ergonomics Society of Korea
• /
• v.30 no.2
• /
• pp.303-310
• /
• 2011

In this study, we employ CPM-GOMS analysis for explaining physical and cognitive processes and for quantitatively predicting when users are typing Korean text messages on mobile phones using both hands. First, we observe the behaviors of 10 subjects, when the subjects enter keypads with both hands. Then, basing upon MHP, we categorize the behaviors into perceptual, cognitive, motor operators, and then we analyze those operators. After that, we use the critical paths to model two task sentences. Also, we used Fitts' law method which was applied many times to predict text entering time on mobile phone to compare with the results of our CPM-GOMS model. We followed Lee's (2008) method that is well suited for text entry task using both hands and calculate total task time for each task sentences. For the sake of comparison between the actual data and the results predicted from our CPM-GOMS model, we empirically tested 10 subjects and concluded that there were no significant differences between the predicted values and the actual data. With the CPM-GOMS model, we can observe the human information processes composed on the physical and cognitive processes. Also we verified that the CPM-GOMS model can be well applied to predict the users' performance when they input text messages on mobile phones using both hands by comparing the predicted total task time with the real execution time.

• The Transactions of The Korean Institute of Electrical Engineers
• /
• v.65 no.12
• /
• pp.2046-2052
• /
• 2016

Ramp metering is one of the most efficient and widely used control methods for an intelligent transportation management system on a freeway. Its objective is to control and upgrade freeway traffic by regulating the number of vehicles entering the freeway entrance ramp, in such a way that not only the alleviation of the congestion but also the smoothing of the traffic flow around the desired density level can be achieved for the maintenance of the maximum mainline throughput. When the cycle of the signal detection is larger than that of the system process, the density tracking problem needs to be considered in the form of the discrete-time system. Therefore, a discrete-time sliding mode control method is proposed for the ramp metering problem in the presence of both input constraint in the on-ramp and exogenous disturbance in the off-ramp considering the random behavior of the driver. Simulations were performed using a validated second-order macroscopic traffic flow model in Matlab environment and the simulation results indicate that proposed control method can achieve better performance than previously well-known ALINEA strategy in the sense that mainstream flow throughput is maximized and congestion is alleviated even in the presence of input constraint and exogenous disturbance.