• Journal of Korea Multimedia Society
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• v.18 no.5
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• pp.682-690
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• 2015

Among location-based systems, a route search service is very highly utilized as a representative technique, but it provides relatively low accuracy when we find a route path on foot in our real environment. In this paper, we design and implement an optimized route search technique based on user experience utilizing open APIs as location-based services. Finally, we develop an Android-based application to provide this feature. In our experiment, we found that our technique enhanced performance by about 14-36% compared to previous solutions, such as route path searches using map APIs. In addition, the performance of our technique can be further enhanced, as the number of users who find such optimized route path is increasing.

• 제어로봇시스템학회:학술대회논문집
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• 1997.10a
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• pp.151-154
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• 1997

An open loop vibrational control of underactuated mechanical systems with amplitude and frequency modulations is investigated. The underactuated systems considered in the paper are assumed to have free joints with no brake. The active joints are positioned first by a linearizing control, and then periodic oscillatory inputs are applied to them to move the remaining free joints to their desired states. A systematic way of obtaining averaged systems for the underactuated systems with oscillatory vibrations is developed. A complete solution to the open loop control strategy in terms of determining amplitudes and frequencies for general system is still under investigation. However, a specific control design for 2R manipulator which is obtained the averaging system is demonstrated.

• Journal of Institute of Control, Robotics and Systems
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• v.21 no.2
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• pp.168-172
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• 2015

In general, open-loop fiber-optic gyroscopes (FOG) are less stable than closed-loop FOGs but they offer simpler implementation. The typical operation time of line-of-sight (LOS) stabilization systems is a few seconds to one hour. In this paper, a open-loop fiber optic gyroscope (FOG) for LOS applications is designed and implemented. The design goal is aimed at implementing a low cost, compact FOG with low Angle Random Walk (ARW) (< $0.03deg/\sqrt{h}$) and bias instability (< 0.25deg/h). The FOG uses an open-loop all-fiber configuration with 100M PM fiber wound on a small diameter spool. In order to get the design goal, digital signal processing techniques for signal detection, modulation control and compensation are designed and implemented in FPGA.

• Journal of Korea Society of Digital Industry and Information Management
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• v.6 no.1
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• pp.33-54
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• 2010

Providing a secure 3-tier Web application has become a high priority for companies as e-businesses have increased the amount and the sensitivity of corporate information that can be accessed through the web. Web applications become more difficult to secure with this very increase in online traffic and transactions. This paper first reviews the 3-tier of web application, types of attacks that can threaten web application services and security principles. We then are designing and implementing a secure web application with open source software that able to mitigate the web application vulnerable to attack.

• Korean Institute of Interior Design Journal
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• no.12
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• pp.33-39
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• 1997

The educational system of Korean elementary schools switches eventually from that of cramming to open study emphasizing student's autonomy and attaching importance to their individuality. Therefore, the purpose of this study is to establish renovational course for conventional classes to practise open education proper to Korean situations at a minimum of expense and time. And the consequence of this study can be summarized as follows : 1) To prepare for various learning activities, a multipurpose space that can be shared by three or four classes is required. 2) Partitions that have divided the existing spaces of unit study must be removed and substituted to a movable partition to make the class variable according to the form of study.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 1995.10a
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• pp.534-537
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• 1995

An open loop vibrational control of underactuated mechanical system with amplitude and frequency modulations is investigated. The underactuated systems sonsidered in the paper are assumed to have free joints with no brake. The active joints are positioned first by a linearizing control, and then periodic oscillatory input are applied to them to move the remaining free joints to their desired states. A systematic way of obtaining averaged systems for the underactuated systems with oscillatory vibration is developed. A complete solution to the open loop control strateegy in terms of determining amplitudes and frequencies for general system is still under investigation. However, a specific control design for 2R manipulator which is obtained through the averaged system is demonstrated.

• Journal of Industrial Technology
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• v.21 no.A
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• pp.199-205
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• 2001

e-book is digital contents using IT technology instead of paper. It is carried in Internet and displayed wish Viewer of PC, PDA or terminal. The Open eBook specification is to provide a specification for representing the content of electronic books to these viewers. The specification is based on HTML and XML, the same core languages that define the World Wide Web, and is designed to allow publishers and authors to deliver their material in a single format. In this paper, we design and implement the viewer that can support OEB(Open eBook) standard. Viewer is composed parser part and display part. In audition, we add some functions - the book shelf, the bookmark and the dictionary - for convenience of readers.

• Journal of the Korea Society of Computer and Information
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• v.22 no.12
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• pp.1-7
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• 2017

More new devices and technologies are recently adapted on homes to aim at enhancing our lifestyle. But though they are not interconnected each other but controlled separately. To solve this problem, we have designed and implemented a common prototype based on openHAB and RaspberryPi they could speak to each other to create a really automated and smart environment at home. The proposed prototype can merge the existing variable devices, add and remove new features at runtime because of its modular design. The proposed prototype based on a low-cost platform showed its potential as a smart home and provide a new UX to users.

• Korean Journal of Computational Design and Engineering
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• v.14 no.2
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• pp.69-76
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• 2009

The development of a simulation system requires many sub modules such as a dynamic module, a visualization module, etc. If a different freeware is used for each sub modules, it is hard to develop the simulation system by incorporating them because they use their own data structures. To solve this problem, a high-level data structure, called Dynamics Scene Graph Data structure (DSGD) is proposed, by wrapping data structures of two freeware; an Open Dynamics Engine (ODE) for the dynamic module and an Open Scene Graph (OSG) for the visualization module. Finally, to evaluate the applicability of the proposed data structure, it is applied to the block erection simulation in shipbuilding. The result shows that it can be used for developing the simulation system.

• Journal of electromagnetic engineering and science
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• v.16 no.1
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• pp.52-56
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• 2016

This paper suggests a class-F power amplifier with split open-end stubs to provide a broadband high-efficiency operation. These stubs are designed to have wide bandwidth by splitting wide open-end stubs into narrower stubs connected in shunt in an output matching network for class-F operation. In contrast to conventional wideband class-F designs, which theoretically need a large number of matching lines, this method requires fewer transmission lines, resulting in a compact circuit implementation. In addition, the open-end stubs are designed with slant ends to achieve additional wide bandwidth. To verify the suggested design, a 10-W class-F power amplifier operating at 1.7 GHz was implemented using a commercial GaN transistor. The measurement results showed a peak drain efficiency of 82.1% and 750 MHz of bandwidth for an efficiency higher than 63%. Additionally, the maximum output power was 14.45 W at 1.7 GHz.