• 한국대기환경학회지
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• 제15권2호
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• pp.201-210
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• 1999

Cyclones have been extensively used in the industry for removing fine particles from the gaseous streams, based on simplicity in design and construction in association with low cost and flexibility to operate in extreme and harsh environments. However, industrial cyclones are typically not very efficient for particles smaller than 10μm. In this work, in order to improve the separation efficiency of reverse flow cyclones, a simple device named Post Cyclone(Poc) in installed on the top of an existing cyclone. Thereby the residual swirl present at the outlet (vortex finder) of a conventional cyclone has been used to capture the escaped dust from the cyclone in the PoC. The performance of PoC was closely evaluated by changing configuration of the PoC and operation condition. In addition, the dust behaviour in th PoC was investigated based on the hypothesis of residual vortex.

• 한국유체기계학회 논문집
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• 제17권1호
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• pp.47-53
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• 2014

This paper aims to present the design and performance evaluation of a counter-rotating tidal turbine using CFD and to compare its performance with single rotor. The device scale is 10kW and the rotating part consists of two rotors which rotate in opposite direction. Compared with conventional single rotor, the counter-rotating system shows higher power efficiency at high stream velocity but lower efficiency at low stream velocity. The added counter-rotated rotor together helps improve the energy absorption capacity but has influence on the upstream rotor that reduces its performance. In terms of power capture, the designed counter-rotating tidal turbine is more advantageous in high speed tidal condition.

• 대한전자공학회:학술대회논문집
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• 대한전자공학회 2007년도 하계종합학술대회 논문집
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• pp.273-274
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• 2007

영상 신호에서 Dynamic Range는 이미지가 포함하고 있는 휘도의 최소 레벨과 최대 레벨의 비이다. 이미지 촬상 장치가 표현할 수 있는 Dynamic Range는 한정되어 있기 때문에 한정된 범위를 벗어나는 영역에 대해서는 이미지의 왜곡 혹은 손실이 발생한다. 본 논문에서는 Line별로 다른 Integration Time을 적용하는 방법으로 영상의 계조 표현 범위를 넓게 향상시켜 Wide Dynamic Range를 갖는 영상을 얻는 방법을 기술한다.

• Archives of Pharmacal Research
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• 제15권2호
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• pp.109-114
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• 1992

For the risk assessment of human exposure to volatile halogenated hydrocarbons, a dynamic purge trap/on-column cryofocusing method using capillary gas chromatograph-$^{63}Ni$ electron capture detector and thermal desorption unit was applied to analyze the free forms, metabolites of 1, 1, 2-trichloroethylene and 1, 1, 2, 2-tetrachloroethylene. The urine sample was diluted with distilled water, hydrolyzed and sealed. Then the inert gas was infused to purge out free 1, 1, 2-trichloroethylene, free 1, 1, 2, 2-tetrachloroethylene and urichloroethanol. These compounds were trapped to $Tenax^R$ / GC-gas trap device throughout clean up tube. Being undertectable to gas chromatograph directly, trichloroacetic acid was methyl esterificated and trapped in the manner above mentioned. The optimal incubation time to get best recovery of methyl ester was 4 hours at $60^circ$C. The concentrations of free volatile halogenated hydrocarbons and their metabolites in urine were obtained of free volatile halogenated hydrocarbons and their metabolites in urine were obtained from 5 healthy volunteers. This analytical method is expected to make the biological monitoring more precise and convenient.

• International journal of advanced smart convergence
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• 제10권4호
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• pp.30-37
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• 2021

Touch sensor interface has become the most useful input device in a smartphone. Unlike keypad/keyboard interfaces used in electronic dictionaries and feature phones, smartphone's touch interfaces allow for the recognition of various gestures that represent distinct features of each application's input. In this paper, we analyze application-specific input patterns that appear in smartphone's touch interfaces. Specifically, we capture touch input patterns from various Android applications, and analyze them. Based on this analysis, we observe a certain unique characteristics of application's touch input patterns. This can be utilized in various useful areas like user authentications, prevention of executing application by illegal users, or digital forensic based on logged touch patterns.

• 한국가스학회지
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• 제15권5호
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• pp.19-24
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• 2011

최근 산업구조가 미래 첨단산업 위주로 전환되면서 자동차를 비롯한 항공기, 휴대폰, 전자기기 등 다양한 산업분야의 제품에 Al, Mg, Li, Zn과 같은 가연성 금속의 사용량이 크게 증가하고 있으며 이러한 가연성 금속의 가공과 정에서 발생하는 금속분진에 의한 폭발 사고 또한 증가하고 있다. 금속분진에 의한 폭발사고는 가연성 금속분진을 포집 및 저장하는 국소배기설비의 공기정화장치에서 대부분 발생함에 따라 공기정화장치내 폭발 발생시 폭발압력에 의한 공기정화장치 구조물의 변형과 파열형태를 단순 예측이 아닌 유한요소해석(FEA)법에 의해 기술적으로 분석 및 제시하고자 본 연구를 수행하였다.

• 수산해양기술연구
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• 제51권3호
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• pp.312-320
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• 2015

The 1/5 scale-down model of the Bycatch Reduction Device (BRD) from an Argentinean demersal trawl was tested in a circulating water channel. The BRD is designed to help small Hake (merluza, merluccius hubbsi) to escape from a trawl. It is settled in front of a trawl codend, and is equipped with selection grids that help small fish to escape from the gear and guiding panels that help fish to meet with the grids. Bars of the grids are wires covered by the PVC and other parts of the BRD are made of net. When the velocity was less than 0.65 m/sec (2.81 Kont when translated to real towing speed) which is slow speed compared with real towing speed, position between an upper guiding panel and an upper selection grid were good to help small fish to escape. When the velocity was more than 0.8 m/sec (3.41 Knot when translated to real towing speed) which is similar to and faster than real towing speed, it was considered that small fish may have difficulties in escaping because the gap was not enough between an upper guiding panel and an upper selection grid. The lower selection grid was sat on the bottom of the tank without an angle due to the weight that it carries. Improvements were proposed to position the panels and the grids better.

• 공학논문집
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• 제6권1호
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• pp.111-124
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• 2004

반도체 기술의 발전과 설계환경의 변화로 비용과 시간이 많이 소요되는 Custom-VLSI 구현 방식보다 Programmable Logic Device (PLD)를 이용한 시스템 구현이 일반화 되어 가는 추세이다. 또한 설계 방식도 Schematic Capture 방식 대신에 보다 효율적이고 표준화된 방식인 Hardware Description Language (HDL)의 활용으로 변화하고 있다. 본 연구에서는 지난 연구 결과를 확장하여 활용영역을 넓혀 가고 있는 다차원 디지털 필터를 PLD를 이용하여 효율적으로 구현할 수 있는 구조를 연구하여 제안하였다. 다차원 디지털 필터링 알고리즘의 효율적인 구현을 위하여 알고리즘 분해방법을 이용하였다. 알고리즘 분해방법은 다차원 디지털 신호처리 알고리즘에 내재된 병렬성을 상태공간식을 이용하여 추출하고, 이로부터 computational primitive(CP)를 얻을 수 있도록 하여준다. 구해진 CP는 VHDL을 이용하여 설계하였으며, 이를 component로 활용하여 효율적인 다차원 디지털 필터를 설계하였다. 설계된 필터를 PLD에 구현함으로써 시스템에 장착된 상태에서 upgrade가 가능하게 되었을 뿐만 아니라, 다차원 디지털 필터를 필요로 하는 모든 시스템의 설계에 component로 사용함으로써 시스템의 Time-to-market 시간을 크게 단축할 수 있다.

• 한국정보통신학회논문지
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• 제20권8호
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• pp.1524-1530
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• 2016

최근 스마트 기기를 이용한 전자 출결 시스템에 대한 연구가 활발히 진행되고 있다. 전자 출결 시스템을 이용하여 교수는 실시간으로 학생들의 출결 처리와 출석 기록을 관리할 수 있다. 본 논문에서는 기존의 자동식별 및 데이터 획득(AIDC, Automatic Identification and Data Capture) 기반의 전자 출결 시스템의 한계점인 공간적, 시간적, 비용적 문제점을 해결할 수 있는 전자 출결 시스템을 제안하였다. 제안하는 시스템은 웹 서버로 동작하며 HTML5(Hyper Text Markup Language ver.5) 기반으로 작성된 출결 관리 페이지에 개인이 가진 스마트 기기를 통한 접속한 후 서버-클라이언트 이미지 데이터 전송 기술을 이용하여 실시간 전자 출결이 가능한 장점이 있다. 또한 제안 시스템은 파이썬 플라스크 프레임워크를 기반으로 동작하기 때문에 운영체제에 상관없이 설치 및 운용이 가능한 장점을 가진다.

• Biomedical Engineering Letters
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• 제8권4호
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• pp.365-371
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• 2018

Uninterrupted monitoring of multiple subjects is required for mass causality events, in hospital environment or for sports by medical technicians or physicians. Movement of subjects under monitoring requires such system to be wireless, sometimes demands multiple transmitters and a receiver as a base station and monitored parameter must not be corrupted by any noise before further diagnosis. A Bluetooth Piconet network is visualized, where each subject carries a Bluetooth transmitter module that acquires vital sign continuously and relays to Bluetooth enabled device where, further signal processing is done. In this paper, a wireless network is realized to capture ECG of two subjects performing different activities like cycling, jogging, staircase climbing at 100 Hz frequency using prototyped Bluetooth module. The paper demonstrates removal of baseline drift using Fast Fourier Transform and Inverse Fast Fourier Transform and removal of high frequency noise using moving average and S-Golay algorithm. Experimental results highlight the efficacy of the proposed work to monitor any vital sign parameters of multiple subjects simultaneously. The importance of removing baseline drift before high frequency noise removal is shown using experimental results. It is possible to use Bluetooth Piconet frame work to capture ECG simultaneously for more than two subjects. For the applications where there will be larger body movement, baseline drift removal is a major concern and hence along with wireless transmission issues, baseline drift removal before high frequency noise removal is necessary for further feature extraction.