• Journal of the Korea Academia-Industrial cooperation Society
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• v.16 no.4
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• pp.2770-2776
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• 2015

The development of efficient wearable antennas is required to implement short range body-centric wireless communication links for various internet of thing applications. We present simulation and measurement results of conductive-fiber-based wearable antennas which can comfortably fabricated directly on usual clothing materials. The proposed antenna is a form of a rectangular patch antenna designed by weaving conductive fibers on a felt substrate. A full-wave electromagnetic simulation tool is used to investigate the antenna performance such as antenna impedance, resonant frequency, and radiation efficiency. Parametric studies show that the radiation efficiency increases from 67.5% to 70.4% by widening the gap between conductive fibers from 0.25mm to 3mm. This implies a wearable antenna with good radiation efficiency can be designed despite of less portion of conductive fibers on the antenna. The simulation results are also verified by measured results with fabricated antennas.

• Journal of Internet Computing and Services
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• v.12 no.5
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• pp.21-28
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• 2011

Recently medical and entertainment applications using conducting textile are suggested, but the data of conducting threads are not characterized, classified and verified. Only the data sheet published by manufacturing companies is available. Thus we need to verify the performances of the threading threads in communication. And we need a guideline if the existing communication protocols can be used for the conducting threads communication or the new specific communication protocols have to be developed for the communication. This paper classifies the characteristics of conducting threads made by domestic and overseas companies. Based on the criteria we classified conducting threads into three classes: class A, class B and class C. Further we carried out experiments to verify the adaptability of existing simple serial communication protocols such as RS232. Six different conducting threads are used in experiments and the length of each thread was 0.5m, 1m, 2m and 3m. The data transmission rate and error rate are collected and analyzed. RS485 is very prone to error due to static electricity from human and environment. So it may not be appropriate as long-distance communication protocol up to 12km which is possible in theory. RS232 shows stable and error-less data transmission ability even though every conducting thread didn’t show transmission capability over RS232. USB protocol shows high data rate transmission but the distance cannot be exceeded over 2m. Additionally, USB requires stable power supply. But if the power is supplied through conducting thread, its function is not.

• Journal of the korean Society of Automotive Engineers
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• v.13 no.4
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• pp.11-17
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• 1991

내연기관의 열전달은 구조물에 따라 흡기계통, 연소실, 배기계통으로 나누어지고, 열전달기구에 따라 전도, 대류, 복사로 나누어지며, 여기서는 그중 가장 핵심이 되는 연소실 내에서의 대류 및 복사 열전달 현상에 관하여 논하고자 한다. 연소실 열전달의 정량적 해석을 위해서는 흡기계통과 피스톤 운동에 의한 3차원 압축성 난류 유동장과 점화, 착화 및 연소 진행과정, 이들의 복합적 상호 작용에 대한 이해가 선행되어야 한다. 여기서는 현재까지 제시된 연소실 열전달의 정량적 모델과 문제점,앞으로의 연구 진행방향에 대해 소개하고자 한다.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.18 no.5
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• pp.10-15
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• 2017

Research interest has strongly focused on developing a method for effectively transmitting bio-signals over a distance using a wireless wearable device. In this paper, we describe a procedure for the design and fabrication of a wearable antenna based on embroidering conductive threads to clothing capable of transmitting electrocardiogram signals. 3D electromagnetic simulation software and embroidery software were used to design and fabricate the conductive thread-based antenna, respectively. The measurement results show that the reflection coefficient of the fabricated antenna prototype exhibits excellent antenna impedance matching characteristics of less than -10dB in the Zigbee 2.4GHz frequency band. We also verified that the electrocardiogram data could be effectively received and monitored in real-time by a receiver 220m away from the transmitter.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2004.05a
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• pp.102-102
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• 2004

산업과 경제의 발달로 그 수요가 급속도로 증대되고 있는 항만물류를 처리하기 위한 여러 가지 항만하역장비에서 가장 핵심은 컨테이너를 선박에 양ㆍ적하하는 장비인 컨테이너 크레인이라 할 수 있다. 최근에는 이러한 컨테이너 크레인도 초대형 컨테이너선의 출현으로 인하여 이에 맞는 구조나 작동 방식을 보유할 수 있도록 연구가 활발히 진행되고 있다.(중략)

• Membrane Journal
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• v.2 no.2
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• pp.112-121
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• 1992

최근 십여년동안 자원, 에너지, 환경의 모든 면에서 기능성막의 역할이 증대해짐에 따라 기능성막에 대해 큰 관심이 모아지고 있다. 기존하는 기능성막의 소재면에서 볼 때 고분자막(고체막), 액체막으로 대별할 수 있으며, 이들의 경우 해수의 담수화, 원료 및 제품의 분리, 농축, 정제, 회수공정 또한 석유화학분야에서 고효율$\cdot$고선택성 기체혼합물 분리, 산업용 폐수처리분야 뿐 만 아니라, 태양에너지의 효과적인 이용, 전도성, 감광성, 광학특성막 등을 이용한 각종 센서제조 등 실로 광범위한 분야에서 응용되어지고 있다. 기능성막의 관점에서 볼 때, 고기능$\cdot$고효율$\cdot$고선택성을 가지는 막은 생태계에 존재하는 생체막이 가장 이상적이라 할 수 있다.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 2005.10a
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• pp.241-246
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• 2005

This study is carried out to analyze the stability of a container crane in according to the change of a wind direction and a machinery house location when a wind load of a wind velocity, 75m/s was applied on the state stowing a container crane by a heavy wind A design wind load applied to this study was calculated in observance of 'Load Criteria of Building Structure'. And we analyzed the reactions of each supporting points according to appling a wind direction to an interval of $15^{\circ}$ in $0^{\circ}\~180^{\circ}$ and the structure stability of a container crane according to changing a machinery house location occupying $15\%$ of a container crane weight. From a results of this study, we presented a design criteria of an overturning disturbance equipment, tie-down.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.19 no.2
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• pp.263-270
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• 2008

In this paper, we investigated EMI(electromagnetic interference) reduction by conductor connection, which was used for fixing and electrical grounding between frames. Conductor connects two frames and then it provides the decrease of return path of signal current. To prove the effect of conductor, we measured/simulated the RE(radiated emission) with/without conductors between the two frames. From the measured/simulated results, we observed that EMI decreased about 1$\sim$10 dB at the frequency range of 30 MHz to 1 GHz. VNA(vector network analyzer) was used to measure the S parameters and the RE was measured in a 3 m anechoic chamber. The simulated and measured results are compared and discussed.

• Composites Research
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• v.19 no.3
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• pp.1-6
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• 2006

As the structures of the high performance electronic equipments and devices recently become more complex, the electromagnetic interference (EMI) and compatibility (EMC) have been very essential for commercial and military purposes. Thus, sensitive electrical devices and densely packed systems need to be protected from electromagnetic wave. In this research, glass fabric/epoxy composites containing conductive multi-walled carbon nanotube (MWNT) and carbon fiber/epoxy composites as electrical shielding materials were fabricated and electrical properties of the composites were measured. The concerning frequency band is from 300 MHz to 1 GHz. The performances of composite shielding enclosures were predicted using electromagnetic wave 3-D simulation tool, CST Microwave Studio. The shielding enclosure made of carbon fiber/epoxy composites were fabricated and the shielding effectiveness (SE) was measured in the anechoic chamber.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2005.06a
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• pp.1605-1608
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• 2005

This study was carried out to analyze the effect of machinery house location on the stability of high efficiency gantry crane which can improve the productivity of the container transportation wok by reducing cycle time. The wind load was evaluated according to 'Load Criteria of Building Structures' enacted by the ministry of construction & transportation. The uplift forces of high efficiency gantry crane under this wind load were calculated by analyzing reaction forces at each supporting point. And variation of reaction forces at each supporting point was analyzed according to machinery house location.