• Transactions of the KSME C: Technology and Education
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• v.1 no.1
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• pp.69-73
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• 2013

This study is about the secondary concentration technology using electrodialysis process for minimum discharge and maximize recovery ratio from seawater desalination by reverse osmosis process. The experimental method adopted the constant voltage driving method and, concentrated/desalination volume capacity ratio changes, voltage changes and electrolyte types. Multi-ion membrane is used, aiming to derive conditions to minimize the TDS concentration of desalination water, to minimize the volumes of secnodary concentraion water and minimizing the power efficiency. The results of this study are as follows. The optimal ratio of concentraion/desalination volume is 1:5, the final TDS concentration of desalinated water is 5.32g/l, the final secnodary concentrated water salinity is 17.07% and electric energy demands of desalinated water is $16.74kWh/m^3$.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.4 no.5
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• pp.919-930
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• 2000

This paper treats a development of visual interactive modeling(VIM) system for ship scheduling problem in integer formulation. The ship scheduling problem can be described as "A problem which assigns ships and cargos to achieve maximum revenue from transportation" in brief. Since late 1970s there has been rapid growth in development and use of VIM as MS10R technology due to the development of computer technology and now VIM has become a important discipline in MS/OR and MIS society. Visual Interactive Modeling is a process that decision maker takes part in modeling life cycle -data collection, formulation, derivation of optimal solution and representation of solution - and interacts with a modeling system to achieve a user-solution appropriate for his/her ultimate goal. This paper suggests the methodology how to collect data, build and modify model, and represent solution using computer graphics as a major driving tool and demonstrates effective performance of a prototype system.pe system.

• Transactions of the Korean Society for Noise and Vibration Engineering
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• v.16 no.7 s.112
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• pp.704-711
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• 2006

Vibration test on MAST(multi axial simulation table) system has several advantage over one-axial vibration test that could simulate 6-DOF, 3-axial translation and 3-axial moment, at the same time. Since field vibration motion can be fully represented with 6-DOF, multi-axial vibration test on vehicle component is widely conducted in technical leading companies to make sure its fatigue performance in vibration environment. On the way to fulfill the process, editing technique of obtained field data is key issue to success a reliable vibration testing with MAST system. Since the original signals are not only too large to fulfill it directly, but all of the measured data is not guarantee its convergency on generating its driving files, editing technique of the original signals are highly required to make some events that should meet the equal fatigue damage on the target component In this paper, key technique on editing a field data feasible for MAST system is described based on energy method in vibration fatigue. To explain its technique explicitly, author first introduced a process on field data acquisition of two vehicle component and then, representing events are produced to keep up with the editing strategy about a energy method. In the final chapter, a time information regarding a vibration test on MAST system is derived from the energy data which is critical information to perform a vibration test.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.19 no.1
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• pp.24-33
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• 2005

This paper presents dimming control system for automotive 35[W] metal halide discharge(MHD) lamp electronic ballast using digital control method. HID system has been becoming increasingly popular due to its superior performance(high luminous efficacy, good color rendering and long life etc.)over the conventional halogen system. However, this lamp demands a highly efficient ballast and very complex control circuitry that can control complex transient state in applying to automotive. Therefore, in this paper, digital control method for the HID lamp ballast is presented for optimal control that can adapt complex transient state, steady state and various environments. In developed dimming system, the system is designed to control the lamp output voltage step by step using microcontroller according to cds sensor. Therefore the designed dimming control system give good driving condition to diver and realize the power control effectively. The results of the proposed system is verified through various simulation results and the experiment results.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.17 no.3
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• pp.762-767
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• 2013

Recently, researches on augmented reality(AR) are actively being conducted, and on addition of AR in social network system has become a necessity. In this paper, we propose GPS-based AR system for social network. This proposed system adds the recent check-in coordinates by automatically synchronizing a friend list in facebook and represents those added location coordinates in a real-world environment by using AR. Marker-based AR system that was commonly used by existing users consumes too much storage space and processing frequency for driving handle devices. But, location-based AR application can solves the disvantages of the standard marker=based AR system. Therefore, this proposed system allows an user with iOS hand devices to use GPS-based AR system by automatically searching the optimal speed for wifi and 4G. This will improve social network service.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.17 no.2
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• pp.164-170
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• 2016

The initial urban railway was only required to perform its role as means of transportation. As the time of staying in an underground platform was extended, it has been faced with the issues of environmental improvement as a living space. Therefore, the sliding automatic door, which is the basis of the screen door, is used widely for large distribution stores, hospitals, restaurants, and public offices for customers' convenience and as a convenient method to control access. Therefore, screen doors are required for the purpose of customers' convenience, securing safety, establishing pleasant station buildings, and energy savings. It would be also necessary to develop the optimal design technology for a screen door system through the design of element parts and to ensure reliability. Therefore, this paper calculated, interpreted, and verified the theoretical weight of the composition parts to verify the design drive hardness of the motor for screen doors necessary for the safety of subways.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2006.05a
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• pp.764-769
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• 2006

Vibration test on MAST(multi axial simulation table) system has several advantage over one-axial vibration test that could simulate 6-DOF, 3-axial translation and 3-axial moment, at the same time. Since field vibration motion can be fully represented with 6-DOF, multi-axial vibration test on vehicle component is widely conducted in technical leading companies to make sure its fatigue performance in vibration environment. On the way to fulfill the process, editing technique of obtained field data is key issue to success a reliable vibration testing with MAST system. Since the original signals are not only too large to fulfill it directly, but all of the measured data is not guarantee its convergency on generating its driving files, editing technique of the original signals are highly required to make some events that should meet the equal fatigue damage on the target component In this paper, key technique on editing a field data feasible for MAST system is described based on energy method in vibration fatigue. To explain its technique explicitly, author first introduced a process on field data acquisition of two vehicle component and then, representing events are produced to keep up with the editing strategy about a energy method. In the final chapter, a time information regarding a vibration test on MAST system is derived from the energy data which is critical information to perform a vibration test.

• Transactions of the Korean Society of Automotive Engineers
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• v.20 no.2
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• pp.123-134
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• 2012

A typical cooling system of an engine relies on a water pump that circulates the coolant through the system. The pump is typically driven by the crankshaft through a mechanical link with engine starting. In order to reduce the friction and warm-up time of an engine, the clutch-type water pump (CWP) was applied in 2.0 liter diesel vehicle. The clutch-type water pump can force cooling water to supply into an engine by the operation of an electromagnetic clutch equipped as the inner part of pump system. The onset of CWP is decided by temperature of cooling water and engine oil. And, the control logic for an optimal operation of the clutch-type water pump was developed and applied in engine and vehicle tests. In this study, the warm-up time was measured with the conventional water pump and clutch-type water pump in engine tests. And the emission and the fuel consumption were evaluated under NEDC mode in vehicle tests. Also, tests were carried out for the various temperature conditions starting the operation of CWP. From the results of the study, the application of CWP can improve the fuel consumption and $CO_2$ reduction by about 3%.

• Journal of the Korean Magnetics Society
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• v.24 no.5
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• pp.160-164
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• 2014

In this paper, an efficient robust design utilizing an enhanced Taguchi method is proposed to reduce cogging torque of a BLDC motor in the presence of design uncertainty. To overcome defects of the conventional Taguchi method in dealing with a generalized robust design problem, a penalty function and an optimal level searching technique are newly introduced. In order to verify the proposed method, a 5 kW, rated speed of 2,300 rpm, rated torque of 20 Nm BLDC motor for driving electric vehicles is optimized. Then, the robust design is compared with conceptual and deterministic ones in terms of the cogging torque, rated torque and torque ripple.

• KIPS Transactions on Software and Data Engineering
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• v.3 no.9
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• pp.369-374
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• 2014

Path generation methods are required for safe and efficient driving in unmanned autonomous vehicles. There are two kinds of paths: global and local. A global path consists of all the way points including the source and the destination. A local path is the trajectory that a vehicle needs to follow from a way point to the next in the global path. In this paper, we propose a novel method for local path generation through machine learning, with an effective curve function used for initializing the trajectory. First, reinforcement learning is applied to a set of candidate paths to produce the best trajectory with maximal reward. Then the optimal steering angle with respect to the trajectory is determined by training an artificial neural network. Our method outperformed existing approaches and successfully found quality paths in various experimental settings, including the cases with obstacles.