• International conference on construction engineering and project management
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• 2015.10a
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• pp.37-38
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• 2015

A number of documents containing important and useful knowledge have been generated over time in the construction industry. Such text-based knowledge plays an important role in the construction industry for decision-making and business strategy development by being used as best practice for upcoming projects, delivering lessons learned for better risk management and project control. Thus, practical and usable knowledge creation from construction documents is necessary to improve business efficiency. This study proposes a knowledge creating system from construction documents using text mining and the design comprises three main steps - text mining preprocessing, weight calculation of each term, and visualization. A system prototype was developed as a pilot study of the system design. This study is significant because it validates a knowledge creating system design based on text mining and visualization functionality through the developed system prototype. Automated visualization was found to significantly reduce unnecessary time consumption and energy for processing existing data and reading a range of documents to get to their core, and helped the system to provide an insight into the construction industry.

• JSTS:Journal of Semiconductor Technology and Science
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• v.5 no.2
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• pp.89-101
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• 2005

Research on highly abstracted system modeling and simulation has received a great deal of attention as of the concept of platform based design is becoming ubiquitous. From a practical design point of view, such modeling and simulation must consider the following: (i) fast simulation speed and cycle accuracy, (ii) early availability for early stage software development, (iii) inter-operability with external tools for software development, and (iv) reusability of the models. Unfortunately, however, all of the previous works only partially addresses the requirements, due to the inherent conflicts among the requirements. The objective of this study is to develop a new system design methodology to effectively address the requirements mentioned above. We propose a new transaction-level system modeling methodology, called ViP (Virtual Platform). We propose a two-step approach in the ViP method. In phase 1, we create a ViP for early stage software development (before RTL freeze). The ViP created in this step provides high speed simulation, lower cycle accuracy with only minor modeling effort.(satisfying (ii)). In phase 2, we refine the ViP to increase the cycle accuracy for system performance analysis and software optimization (satisfying (i)). We also propose a systematic ViP modeling flow and unified interface scheme based on utilities developed for maximizing reusability and productivity (satisfying (ii) and (iv)) and finally, we demonstrate VChannel, a generic scheme to provide a connection between the ViP and the host-resident application software (satisfying (iii)). ViP had been applied to several System-on-a-chip (SoC) designs including mobile applications, enabling engineers to improve performance while reducing the software development time by 30% compared to traditional methods.

• Journal of Engineering Education Research
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• v.17 no.2
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• pp.35-41
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• 2014

This paper deals with the ways that can improve the reliability of the course evaluation system based on reformation of the system and design of user interface for the practical applications. In the reformation of the system aspect, there are the improvements of the course evaluation questionnaires and the feedback of course evaluation to the lecturers. In the design aspect, a computer screen of the graphic user interface is redesigned to reflect the reformation of the system aspect issues. The results show the effectiveness in the reliability improvement.

• Journal of Institute of Control, Robotics and Systems
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• v.9 no.10
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• pp.808-815
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• 2003

Fieldbus technology is having a massive impact on the development of faster, smarter and less expensive industrial networking systems. However, there have been a few of practically applied cases and channels for obtaining technical advices. Moreover, the users in the industry don't trust the Fieldbus technology like they didn't trust PLC control system in 1970s. Therefore, in this paper, Air flow control system is constructed by Fieldbus technologies, Profibus and Inverter that controls the motor speed. With the features of the motor control, the amount of electric power consumption by the speed control of motor is measured by the constructed control system. From this measured result, the effectiveness of the airflow control system and Feasibility to the practical industry field is demonstrated To improve the confidence of Fieldbus technology, practically embodied cases and technical methods are presented.

• Journal of the Korean Society for Nondestructive Testing
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• v.19 no.4
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• pp.294-299
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• 1999

In this paper, the calibration system for contact transducer has been developed to improve the reliability of the inspection result of ultrasonic testing on rotors. This system consists of signal processing parts: (oscilloscope, spectrum analyzer, pulser/receiver), standard block, and user interface program. Signal processing for the calibration system was performed quickly with high accuracy. The developed system has been applied to a practical calibration of probe using the non-destructive testing on rotors, and demonstrated high sensitivity and precision.

• Management Science and Financial Engineering
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• v.1 no.1
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• pp.1-19
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• 1995

In this paper, we analyze an M / M / 1 queueing system where there are incentive conflicts among customers. Self-interested customers' decisions whether to join the system or not may not necessarily induce a socially optimal congestion level. As a way to alleviate the over-congestion, toll imposition was used in Naor's paper [3]. Instead of using a toll mechanism, we study the usefulness of imperfect information on system state (queue size, for example) as a way to reduce the over-congestion by self-interested customers. The main conclusion of this paper is that by purposefully giving fuzzy or imperfect information on the current queue size we can improve the congestion in the system. This result might look contradictory to rough intuition since perfect information should give better performance than imperfect information. We show how this idea is verified. In deriving this result, we use the concept of Nash equilibrium (pure and mixed strategy) as introduced in game theory. In some real situations, using imperfect information is easier to apply than imposing a toll, and thus the result of this paper has practical implications.

• Journal of Ocean Engineering and Technology
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• v.16 no.6
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• pp.25-31
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• 2002

A system identification method is introduced to increase the prediction accuracy of a ship's maneuverability in PMM test, analysis. To improve the accuracy of linear hydrodynamic coefficients, the analysis techniques of pure sway and yaw tests are developed, and confirmed. In the analysis of sway tests, accuracy to linear hydrodynamic coefficients depends on the frequency of sway motion. To obtain nonlinear hydrodynamic coefficients for large drift angles, a combined yaw test is introduced. Using this system identification method, runs of PMM test can be reduced while retaining sufficient accuracy, compared to the Fourier integration method. Through the comparisons with sea trial results and the Fourier integration method, the accuracy and efficiency of the newly proposed system identification method, based on least square method, has been validated.

• Proceedings of the Korean Operations and Management Science Society Conference
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• 1996.10a
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• pp.275-278
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• 1996

We propose dynamic file allocation method in distributed database management system with changing access patterns. There are a lot of studies on file allocation problem in D-DBMS, and those studies deal with off-line analysis and optimization. Those works are well for systems with static database access patterns, but are inadequate for systems that have changing access patterns. In these systems, dynamic file allocation along with access pattern is more proper. In advance, Brunstrom et al. studied on this area, but they dealt a extremely simplified model. So, we make more practical models to simulate real system. In these models, many factors that were disregard in the advance study are considered. These models are composed with the non-replication system and the replication system. In addition to, we deal with CPU workload balancing in such system in order to improve performance of systems. Our methodology is very simple and realistic, therefore we think that it will give a lot of improvement in D-DBMS with changing access pattern.

• Proceedings of the KIEE Conference
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• 2006.04a
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• pp.54-56
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• 2006

To get the robust and reliable input command, we designed shaping function for target tracking system with commander's handle. Input signals of the commander's handle are generated by human operator. It is response of the human to reduce the error between target and gun. But, tracking error while operator aim a moving target manually gives poor system performance. Input noise, particularly, affects hit accuracy as the system performance. We proposed the design method of input command shaping to reduce the Input noise and to improve the operation ability and convenience. We performed the experiments with combat vehicle, example of Target Tracking System, to show the proposed method is efficient and practical.

• Proceedings of the KIPE Conference
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• 2003.07b
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• pp.987-993
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• 2003

The module UPS can flexibly implement expansion of power system capacities. Furthermore, it can be used to build up the parallel redundant system to improve the reliability of power system operation. To realize the module UPS, load sharing without interconnection among parallel connecting modules as well as a small scale and lightweight topology is necessary. In this paper, the three-arm converter/inverter is compared with the general full-bridge and half-bridge topology from a practical point of view and chosen as the module UPS topology. The switching control approaches based on a pulse width modulation of the converter and inverter of the system are presented independently The frequency and voltage droop method is applied to parallel operation control to achieve load sharing. Two prototype 3kVA modules are designed and implemented to confirm the effectiveness of the proposed approaches. Experimental results show that the three-arm UPS system has a high power factor, a low distortion of output voltage and input current, and good load sharing characteristic.