• Journal of the Institute of Electronics and Information Engineers
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• v.53 no.5
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• pp.143-151
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• 2016

The aim of this study is to investigate the optimal algorithm to extract medical radiation induced pixel signal from complementary metal-oxide semiconductor (CMOS) sensors of smartphones camera. The pixel intensity and pixel number of smartphone camera were measured as the X-ray dose was increased. The front camera of the smartphone camera has low noise property and excellent dose response as compared to the back camera of the smartphone. The indirect method which uses scintillation crystal in front of the smartphone camera, couldn't improve the X-ray detection efficiency as compared to the direct method which does not use any scintillator in front of the smartphone camera. When we used the algorithm which employing threshold level on the pixel intensity and pixel number, the dose linearity was more higher for the pixel intensity rather for the pixel number. The use of pixel intensity of Y color component which represents the grey scale, would be efficient in terms of the radiation detection efficiency and reducing the complexity of the image processing. We expect that the radiation dose monitoring can be managed effectively and systematically by using the proposed radiation detection algorithm, thus eventually will contribute to the public healthcare.

• Journal of the Korean Society of Hazard Mitigation
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• v.9 no.5
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• pp.79-86
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• 2009

With the substantial increase of the size of structure, the management of excavation becomes more difficult. Therefore, massive collapses which are related to retaining wall recently increase. However, since the study on measuring and monitoring the pre-stressing force of anchor is insufficient, behavior of anchor may not be predicted and monitored appropriately by the existing strain gauge and load cell type monitoring system. FBG Sensor, which is smaller than strain gauge and has better durability and does not have a noise from electromagnetic waves, is adapted to measure the strain and pre-stressing force of 7-wire strand, so called smart tendon. A series of pullout tests were performed to verify the feasibility of smart tendon and find out the load transfer mechanism around the steel wire tendon fixed to rock with grout. Distribution of measured strains and estimated shear stresses are compared with those predicted by theoretical solutions. It was found that developed smart tendon can be used effectively for measuring strain of 7-wire strand anchor and theoretical solutions underestimate the magnitude of shear stress and load transfer depth.

• Proceedings of the Korean Society of Broadcast Engineers Conference
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• 2019.11a
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• pp.93-93
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• 2019

최근 에너지 효율에 따른 에너지 관련 통신기술의 스마트화 및 융복합화가 진행되고 있다. 또한 기존에 인터넷망만을 이용한 통신기술 외에 유사시 상황을 위한 전력선 통신 기술 개발이 진행되고 있다. 현재 전력선통신은 변복조 모뎀을 전력선 양단에 연결한 뒤 기존에 사용되는 무선통신기술을 변환하는 형태로 사용되고 있다. 이는 낮은 주파수와 높은 전력을 가지는 전력선 특성에 맞지 않아 전력선 통신에 알맞은 통신기술 개발이 필요하다. 이에 본 논문은 전력의 부하에 따라 최적의 에너지 효율을 검색하고 이에 따라 통신 방식을 변경하는 방식을 연구하였다. 이를 위하여 전력선 통신에서 규격별 잡음 모델링을 연구하고 이에 따른 통신방식을 연구하였다.

• KIISE Transactions on Computing Practices
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• v.20 no.11
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• pp.592-597
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• 2014

In this paper, we propose an adaptive transformation engine that provides smart devices with optimal user interfaces and media contents to their characteristics so as to conveniently control home networks remotely using smart devices in the wired and wireless home networks which various kinds of smart devices and home network devices are connected. The proposed engine dynamically transforms UI contents and transfers them using device profiles and UI transformation policies to make it suitable for smart devices. Moreover, the proposed engine offers suitable media contents for smart devices through capabilities of real-time media transcoding and streaming considering device and media profiles.

• Proceedings of the Korean Society of Computer Information Conference
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• 2013.07a
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• pp.361-363
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• 2013

본 논문에서는 최근 스마트 헬스케어가 보건의료서비스에 특화시켜 환자와 의사가 직 간접적으로 진료를 할 수 있게끔 하는 스마트폰 환경에서의 원격진료 서비스가 부각됨에 따라 유무선 통신 인프라를 기반으로 노인, 만성질환자, 회복중인 환자나 수술 후 환자 그리고 일반인 등이 일상생활을 하면서 불편하거나, 거추장스럽지 않게 신체 정보를 측정하고 건강상태의 변화에 대한 전문가의 진단을 즉각적으로 제공하기 위해 Bluetooth HDP(Health Device Profile)을 통해 IEEE11073 PHD 표준 기반의 홈 헬스케어 의료기기 연결성을 보장하며, HL7 CDA 기반의 정보 전달 구조로 의료진뿐만 아니라 다양한 스마트 앱 어플리케이션 간의 융합을 가능하게 하는 스마트 헬스케어 솔루션을 설계하고자 한다.

• The Journal of the Korea Contents Association
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• v.13 no.9
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• pp.49-57
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• 2013

Recently, in spite of fast development of smartphone, recording technology has saved, listened and searched in server based on PSTN and wired network. We introduce a mobile transcript recording system for mobile office environment. All calls using smartphone are automatically saved on memory in mobile device with this system. Thereafter, recording files are encrypted and uploaded to recording server by user authority. Beside recording data in database on web server is saved and managed efficiently and economically through web application. This system is able to be used in legal corroborative facts and the prevention of crime such as voice phishing.

• Proceedings of the Korea Information Processing Society Conference
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• 2015.04a
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• pp.205-206
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• 2015

스마트폰이 유선전화의 단말기가 되면 스마트폰의 전화번호부를 유선통화에도 사용할 수 있게 되어 유선전화의 사용량이 늘어나고, 이를 통해 사용자는 통신요금이 낮아지는 혜택을 누리며 유선 사업자는 수익 증대를 기대할 수 있다. 그러나 이동통신용 단말기로 제작된 스마트폰을 유선전화의 단말기로 이용하는 데는 i) 사용자 편의성 증대를 위한 스마트폰 등록 절차의 간소화, ii) 저전력 상태와 WiFi 비활성화 상태에서 전화수신 안정화, iii) 무선데이터 전송시간 변이에 의한 음성품질 저하 회피 등 다양한 기술적 문제들이 존재한다. 본 논문에서는 이와 같은 문제들에 대한 해결 방안을 제시하고 이를 반영한 실험용 시스템의 구현 결과를 보여준다. 실험용 시스템은 사설교환기 기능을 내장한 WiFi-AP, 안정적인 전화수신 알림을 위한 PUSH broker, VoIP 어플리케이션이 설치된 스마트폰으로 구성된다. 실험용 시스템은 PSTN 망과 VoIP 망에 연동하여 스마트폰으로 안정적인 통화품질을 제공할 수 있음을 보였다.

• The Journal of the Korea institute of electronic communication sciences
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• v.9 no.5
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• pp.601-608
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• 2014

In this study we propose an image denoising algorithm appropriate for mobile smart phone equipped with limited computing ability, which has better performance and at the same time comparable quality comparing with previous studies. The proposed image denoising algorithm for mobile smart phone cameras in low level light environment reduces computational complexity and also prevents edge smoothing by extracting just Gaussian noises from the noisy input image. According to the experiment result, we verified that our algorithm has much better PSNR value than methods applying mean filter or median filter. Also the result image from our algorithm has better clear quality since it preserves edges while smoothing input image. Moreover, the suggested algorithm reduces computational complexity about 52% compared to the method applying original Laplacian mask computation, and we verified that our algorithm has good denoising quality by implementing the algorithm in Android smart phone.

• Aerospace Engineering and Technology
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• v.5 no.2
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• pp.240-247
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• 2006

Tilt rotor aircraft is a multi-configuration airplane which has three independent flight modes; helicopter, conversion, and aiplane. The control surface mixer resign is reqctired to generate and distribute efficient control forces and moments in each flight mode. In the conversion mode, the thrust vector is changed from helicopter mode to airplane, therefore the thrust vector makes undesired forces and moments which affect on pitch, roll and yaw dynamics. This paper describes the design results of control surface mixer design which minimize the undesired forces and moments due to nacelles tilting angle change for 4O% scaled model.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2018.10a
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• pp.265-267
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• 2018

This paper addresses the study of wired and wireless gateway with IoT Standard. The gateway that we develop through this study is designed to be utilized for collection energy information among various serveces. It is aimed at the role as an Advanced Metering Infrastructure which is a core infrastructure for Smargrid services. To this end, the gateway has a structure that can apply the IoT standard and the network technology used in the Smartgrid. These gateway can be applied with small and medium energy consumer that require energy information collection.