• Proceedings of the Korean Society of Broadcast Engineers Conference
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• 2014.11a
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• pp.154-155
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• 2014

본 논문에서는 TV 시청환경에서의 실내소음의 스트레스 평가를 위한 소음 데이터베이스(database, DB) 설계 방법을 제안한다. 제안된 DB 는 TV 시청공간을 포함하는 실제 주거환경 내에서 binaural recording을 위한 1 개의 dummy head 와 multi-channel recording 을 위한 2 개의 다채널 마이크 배열을 활용하여 TV 콘텐츠 및 실내소음의 음향 정보를 취득한다. 설계된 DB는 TV 시청자의 청각정보에 해당하는 binaural recording 신호와 실내소음의 위치 및 종류 추정을 위한 multi-channel recording 신호를 모두 포함하기 때문에 TV 시청환경에서 실내소음이 시청자에게 유발하는 스트레스의 분석 및 평가 관련 연구에 적합하게 설계되었다. 본 DB 는 5 가지 종류의 TV 콘텐츠 10 시간 분량, 30 가지 종류의 실내소음 2 시간 분량으로 구성되었다.

• Laser Solutions
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• v.12 no.1
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• pp.14-18
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• 2009

Ripple formation of femtosecond laser in stainless steel is investigated using 184 fs pulses with a center wavelength of 785 nm. The effect of the laser polarization relative to the translation direction is observed. For drilling with a certain aspect ratio, reflections at the hole walls take place, leading to a non-uniform intensity distribution deep inside the formed hole. Finally, it is shown that a circular polarization during the drilling process significantly improves the quality of the produced holes.

• Proceedings of the KSEEG Conference
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• 2005.04a
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• pp.189-189
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• 2005

• Journal of Gastric Cancer
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• v.15 no.4
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• pp.290-294
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• 2015

C-kit-negative gastrointestinal stromal tumors (GISTs) are uncommon, and there have been few reports about the diagnosis and treatment of c-kit-negative GISTs in the stomach. We report the case of a patient who was diagnosed with a huge and atypical GIST in the stomach. The GIST was completely resected and finally diagnosed as c-kit-negative GIST based on immunohistochemical staining of tumor cells, which were negative for CD117 and CD34 and positive for Discovered on GIST-1 (DOG1). C-kit-negative GISTs could be treated by complete resection and/or imatinib, which is the same treatment for c-kit-positive GISTs.

• Proceedings of the Korean Magnestics Society Conference
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• 2013.12a
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• pp.163-163
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• 2013

• Journal of the Optical Society of Korea
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• v.12 no.3
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• pp.186-191
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• 2008

A phase retrieval method using an error reduction algorithm is developed for reconstructing a wavefront aberration of an 100-TW Ti:sapphire laser pulse from the measurement of a focal spot. The phase retrieval method can successfully reconstruct a wavefront aberration of a 100-TW Ti:sapphire laser pulse, and the reconstructed wavefront aberration shows a good agreement with the wavefront aberration measured with a wavefront sensor. The effect of the dynamic range and the intensity noise on the reconstruction is also investigated in reconstructing a wavefront aberration of an 100-TW Ti:sapphire laser pulse.

• ETRI Journal
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• v.27 no.6
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• pp.802-805
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• 2005

A dynamic bandwidth allocation (DBA) scheme, an inter -optical network unit (ONU) bandwidth scheduling, is presented to provide quality of service (QoS) to different classes of packets in Ethernet passive optical networks (EPONs). This scheme, referred to as TADBA, is based on efficient threshold reporting from, and adaptive polling order rearranging of, ONUs. It has been shown that the network resources are efficiently allocated among the three traffic classes by guaranteeing the requested QoS, adaptively rearranging the polling orders, and avoiding nearly all fragmentation losses. Simulation results using an OPNET network simulator show that TADBA performs well in comparison to the available allocation scheme for the given parameters, such as packet delay and channel utilization.

• Proceedings of the IEEK Conference
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• 2006.06a
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• pp.95-96
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• 2006

A variety of systems have been attempted for effective urban management. In this paper, we introduce integrated urban management system (IUMS), which mainly consists of optical line terminal (OLT), optical network terminal (ONTs) and wireless access points (APs), by combining passive optical network (PON) and radio over fiber (RoF) technologies so as to take advantages of both two systems. Further, several IUMS services including disaster detection and prevention system (DDPS), bus information system (BIS) and real time location system (RTLS) are demonstrated in order to employ IUMS for the realization of future ubiquitous city (U-city).

• Proceedings of the IEEK Conference
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• 2006.06a
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• pp.53-54
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• 2006

In this paper, we analytically evaluate packet delay and energy consumption of S-MAC protocol with a modified Markov chain model. Although some models, based on IEEE 802.11 MAC protocol, to analyze the S-MAC protocol in wireless sensor network (WSN) have been proposed, they fail to consider the differences in architecture between the S-MAC and the 802.11 MAC. Therefore, by reflecting the significant features in the S-MAC function, we model the operation of S-MAC protocol, and derive its packet delay and energy consumption in single-hop WSN. Numerical results show the delay and the dissipated energy at various duty cycle values according to offered load, where a practical mote is used.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.38C no.6
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• pp.497-502
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• 2013

In this paper, we aim to evaluate the performance of the digital signal processing (DSP) algorithm used in [8] in order to improve the resolution of spectrometers with fixed number of low-cost, non-ideal filters. In such spectrometers, the resolution is limited by the number of filters. We aim to demonstrate via new experiments that the resolution improvement by six times over the conventional limit is possible by using the DSP algorithm as claimed by [8].