• 교육녹색환경연구
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• 제10권1호
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• pp.53-63
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• 2011

The purpose of this study is to suggest a scheme to provide children safer and more comfortable walking circumstances by survey current walking circumstances of schoolzone ways. A scheme suggested in this study was based on the analysis of survey to elementary school in 3 Newtowns(Dongtan, Dongbaek and Gumdan City) and actually surveyed data on school zone, the scheme can be summed up as follows; First, to avoid pedestrian roads being interrupted and to expend waiting space near schoolzone ways, several measures are needed including fixing roads and building additional gateway. Second, pedestrian crossings in front of school gate should be located at least 30m away from the left side of the gate. Third, to secure pedestrians' safety in school zone ways should be planed and established more security concepts und facilities.

• 교육녹색환경연구
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• 제10권2호
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• pp.20-29
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• 2011

The purpose of this study is to suggest a scheme to provide children safer and more comfortable walking circumstances by survey current walking circumstances of schoolzone ways. A scheme suggested in this study was based on the analysis of survey to elementary school in 3 Newtowns(Dongtan, Dongbaek and Gumdan Districts) and actually surveyed data on school zone, the scheme can be summed up as follows; First, to avoid pedestrian roads being interrupted and to expend waiting space near schoolzone ways, several measures are needed including fixing roads and building additional gateway. Second, to secure pedestrians' safety in school zone ways should be planned and established more security concepts und facilities Third, to improve the walking safety in schoolzone way should be established specially "schoolzone B-plan".

• ETRI Journal
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• 제36권2호
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• pp.188-196
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• 2014

This paper describes a simple delay diversity technique for terrestrial digital multimedia broadcasting (T-DMB) and digital audio broadcasting in a single-frequency network (SFN). For the diversity technique, a delay diversity scheme is adopted. In the delay diversity scheme, a non-delayed signal is transmitted in the first antenna, and delayed versions of the signal are transmitted in each additional antenna. For an SFN environment with multiple transmitters, delay diversity can be executed by controlling the emission times of the transmitters. This SFN delay diversity scheme does not require any hardware changes in either the transmitter or receiver, and perfect backward compatibility can be acquired. To evaluate the performance improvement, laboratory tests are executed with various types of commercial T-DMB receivers as well as a measurement receiver. The improvement in the bit error rate performance is evaluated using a measurement receiver, and an improvement of the threshold of visibility value is evaluated for commercial receivers. Test results show that the T-DMB system can obtain diversity gain using the described technique.

• 공학교육연구
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• 제11권3호
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• pp.96-107
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• 2008

본 연구는 공과대학의 공학윤리 교육과목 실태분석을 통한 개선방안 도출을 위해, 공학 윤리에 대한 개념 및 공학윤리 교육과목의 도입배경, 공학윤리 교육의 목적 및 교육방법, 내용에 대한 문헌조사를 실시하였으며, 국내외 공학윤리 교육현황을 도출하였다. 이를 기초로 공학윤리 교육과목 개선방안 제시를 위한 공학윤리 수강생 및 기업의 인사담당자를 대상으로 설문조사를 실시하여 국내 공학윤리 교육과목에 적합한 개선방안을 제시하였다.

• 제어로봇시스템학회논문지
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• 제17권1호
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• pp.72-77
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• 2011

The checkpointing scheme is a well-known technique to cope with transient faults in digital systems. This paper proposes an adaptive checkpointing scheme for the reliability improvement of real-time control systems with concurrent fault detection capability. With concurrent fault detection capability the effect of transient faults are assumed to be detected with no latency. The proposed adaptive checkpointing scheme is based on the reliability analysis of an equidistant checkpointing scheme. Numerical data show the proposed adaptive scheme outperforms the equidistant scheme from a reliability point of view.

• International Journal of Contents
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• 제12권4호
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• pp.17-22
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• 2016

This paper presents a novel method to design and implement mobile u-health system by defining the essential elements of mobile healthcare services. We choose common service elements for the proposed u-healthcare scheme and design the service platform. Especially we focus on automatic feces or urine sensing u-care scheme to prove the effectiveness of our platform. We construct the system with sensing part with a manikin and a diaper, wireless communication part with feces or urine sensing data, and coordinator system based on the u-health platform defined in this paper. Experimental results show that our scheme is useful in the area of u-care service for the handicapped, the elderly, and patients who can hardly move by themselves. In addition the designed scheme offers a realized u-care scheme with the purpose of advanced developing tools for application or service developers.

• Journal of Communications and Networks
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• 제10권1호
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• pp.10-17
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• 2008

In traditional digital signature schemes, certificates signed by a trusted party are required to ensure the authenticity of the public key. In Asiacrypt 2003, the concept of certificateless signature scheme was introduced. The advantage of certificateless public key cryptography successfully eliminates the necessity of certificates in the traditional public key cryptography and simultaneously solves the inherent key escrow problem suffered in identity-based cryptography. Recently, Yap et al. proposed an efficient certificateless signature scheme and claimed that their scheme is existentially unforgeable in the random oracle model. In this paper, we show that the certificateless signature scheme proposed by Yap et al. is insecure against public key replacement attacks. Furthermore, we propose an improved certificateless signature scheme, which is existentially unforgeable against adaptive chosen message attacks under the computational Diffie-Hellman assumption in the random oracle model and provide the security proof of the proposed scheme.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제9권8호
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• pp.3068-3078
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• 2015

Although the massive MIMO system supports a high throughput, it requires a lot of channel information for channel compensation. For the reduction of overhead, the massive MIMO system generally uses TDD as duplexing scheme. Therefore, the massive MIMO system is sensitive to rapidly changing fast fading in according to time. For the improvement of reduced SINR by fast fading, the adaptive power control is proposed. Unlike the conventional scheme, the proposed scheme considers mobility of device for adaptive power control. The simulation of the proposed scheme is performed with consideration for mobility of device. The result of the simulation shows that the proposed scheme improves SINR. Since SINR is decreased in according to the number of device in the network by unit of cell, each base station can accommodate more devices by the proposed scheme. Also, because the massive MIMO system with high SINR can use high order modulation scheme, it can support higher throughput.

• 대한안전경영과학회지
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• 제19권3호
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• pp.27-33
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• 2017

Electrical product safety certification is for public safety. Korea electrical safety certification (KC) is being tested and certified on the base of Korean electrical appliance safety act and KC scheme. There are operating system and Electrical safety standards in the KC scheme. KC' operating system was adapted from japan operating system of Japan certification scheme. But KC certification' electrical safety standard was adapted from IEC standards of IECEE CB scheme. So There are many problems such as difference of version between KC standards and IEC standards, discrepancy between operating system and standards. Therefore, This paper analyzed the reason of discrepancy and proposed the improved KC certification operating system in order to reduce cost and to save time in the procedure of issuing KC approval for public safety in using electrical products and also for global competence.

• Journal of Advanced Marine Engineering and Technology
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• 제20권3호
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• pp.137-143
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• 1996

The propulsion marine diesel engine has been widely applied with a mechanical-hydraulic governor to control the ship speed for long time. But it was recently very difficult for the mechanical-hydraullic governor to control the speed of engine under the condition of low speed and low load because of jiggling and hunting by rough fluctuation of rotating torque. To solve these problems of control systems, the performance improvement of mechanical-hydraulic governor is required. In this paper, in order to analyze the speed stability of control systems, the influence of parameters of the engine dead time, gain, damping ratio was discussed on the view of control engineering. The performance improvement of a conventional mechanical hydraulic governor is confirmed to be possible by fuzzy control scheme.