• 한국정밀공학회지
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• 제23권9호
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• pp.179-189
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• 2006

Recently the electrostatic 2-axis MEMS stages have been fabricated f3r the purpose of an application to PSD (Probe-based Storage Device). However, all of the components (platform, comb electrodes, springs, anchors, etc.) in those stages are placed in-plane so that they have low areal efficiencies such as a few percentage, which is undesirable as data storage devices. In this paper, we present a novel structure of an electrostatic 2-axis MEMS stage that is characterized by having a large areal efficiency of about 25%. For obtaining large area efficiency, the actuator part consisting of mainly comb electrodes and springs is placed right below the platform. The structure and operational principle of the MEMS stage are described, followed by a design and analysis, the fabrication and measurement results. Experimental results show that the driving ranges of the fabricated stage along the x and y axis were 27$\mu$m, 38$\mu$m at the supplied voltages of 65V, 70V, respectively and the natural frequencies along x and y axis were 180Hz, 310Hz, respectively. The total size of the stage is about 5.9$\times$6.8mm$^2$ and the platform size is about 2.7$\times$3.6mm$^2$.

• 한국자기공명학회논문지
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• 제17권2호
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• pp.81-85
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• 2013

Various fluorine-containing materials are used in electronic devices like LCD display panels and Li-ion batteries. The structural conformation of fluorine in fluorinated materials is an important contributing factor that influences the chemical and physical properties. The conformation can be changed by heat and stress during manufacture or use. Understanding the conformational changes is critical for understanding the performance and durability of electronic devices. Solid-state NMR spectroscopy could be widely used for the analysis of various fluorine-containing materials for electronic devices. However, conventional CPMAS probes cannot be used for in-situ analysis of fluorine-containing electronic devices like LCD panels and Li-ion batteries. In this paper, we show the design, construction, and optimization of a $^{19}F-^{13}C$ double-resonance solid-state NMR probe for a 400MHz wide-bore magnet with a flat square coil for in-situ analysis of fluorine-containing electronic devices without observing fluorine background signals. This custom-built probe does not show any fluorine background signals, and can have higher efficiency for lossy samples.

• The Plant Pathology Journal
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• 제37권3호
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• pp.291-298
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• 2021

False smut caused by Ustilaginoidea virens is an important rice fungal disease that significantly decreases its production. In the recent past, conventional methods have been developed for its detection that is time-consuming and need high-cost equipments. The research and development in nanotechnology have made it possible to assemble efficient recognition interfaces in biosensors. In this study, we present a simple, sensitive, and selective oxidized graphene-based geno-biosensor for the detection of rice false smut. The biosensor has been developed using a probe DNA as a biological recognition element on paper electrodes, and oxidized graphene to enhance the limit of detection and sensitivity of the sensor. Probe single-stranded DNA (ssDNA) and target ssDNA hybridization on the interface surface has been quantitatively measured with the electrochemical analysis tools namely, cyclic voltammetry, and linear sweep voltammetry. To confirm the selectivity of the device, probe hybridization with non-complementary ssDNA target has been studied. In our study, the developed sensor was able to detect up to 10 fM of target ssDNA. The paper electrodes were employed to produce an effective and cost-effective platform for the immobilization of the DNA and can be extended to design low-cost biosensors for the detection of the other plant pathogens.

• 한국실내디자인학회논문집
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• 제19권6호
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• pp.112-120
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• 2010

Human can recognize the environment by detecting spatial perception, and most of environmental perception depends on visual perception. In view that the acquisition of spatial information is accomplished through visual recognition, analysis of visual structure contained in the space is thought to be very important sector in studying the characteristic of the space. The history of studies on visual structure of space, however, wasn't too long, and furthermore most of the theories up to now focused on static and planar principles. Under this circumstance, this study is intended to suggest new theory by combining Isovist theory and VGA theory that have been actively discussed as the theory on visual perception-based spatial structure and supplementing them between each other to expand into 3-dimensional model. The suggested theory is a complex principle in dimensional and dynamic form in consideration of visual direction, which forms 3-dimentional virtual model that enables visualization of the property of spatial structure as the routine discriminating whether visual connection is made between viewing point and target point, and the target point is included in the visual field quadrangular pyramid or not. Such model was built up by an analysis application where four probe paths were applied to simulate the visual structure that occurs in virtual space, and then the characteristics were analyzed through quantification. In result, in spite of the path with equal space and equal length, significant difference in the acquired quantity of spatial information could be found depending on the probe sequence. On the contrary, it was found that probe direction may not affect the acquired quantity of information and visual property of the space.

• 대한전자공학회논문지TC
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• 제46권5호
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• pp.154-161
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• 2009

최근 들어 작은 면적에 고속으로 동작하는 여러 기능 블록이 집적됨에 따라, 고속 직접회로는 인접회로의 오동작을 유발하고, 무선 수신기의 감도를 떨어뜨리는 중요한 전자파 간섭원으로 부각되고 있다. 따라서 집적회로 내부에서 가장 주요한 전자파 방해원을 파악하기 위한 좀 더 정밀한 분석 도구가 필요하게 되었다. 이러한 필요성에 따라 본 논문에서는 직접회로의 표면에 흐르는 전류세기의 분포를 측정할 수 있는 고해상도 자기장 프로브를 반도체 공정을 이용하여 설계 및 제작하였다. 3층 금속 배선이 가능한 반도체 공정을 이용함으로써 프로브 두께를 기존 작업보다 약 10%정도로 감소시킬 수 있었다. 정자기 해석과 전자기 모의실험을 통해 프로브의 공간분해능 및 비자기장 성분에 의한 영향을 분석하였으며, 실제 직접회로의 표면 전류를 측정한 결과, $210{\mu}m$의 공간해 상도를 얻을 수 있음을 확인하였다.

• 한국컴퓨터정보학회논문지
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• 제18권3호
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• pp.27-34
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• 2013

L-스트립 급전선에 의해서 급전되는 광대역 패치 안테나를 연구하였다. 본 논문의 목표는 3G와 4G 이동통신 서비스를 위한소형광대역안테나를설계하는데목표를두었다. 기존 유사 연구문헌에 보고 되었던 안테나와 본 논문의 제안된 안테나를 비교하여 개선된 효과를 입증하였다. L-스트립 급전의 삼각형 패치 안테나의 측정결과에서 636MHz(32.5%, fo=1,960MHz)의 임피던스 대역폭($VSWR{\leq}2$)이 3G와 4G 주파수 대역에서 얻어지는 것을 확인하였다. 일반적으로 Probe 급전방식의 경우 Probe에 의해서 기생 리액턴스가 야기되며 이로 인하여 안테나의 대역폭 특성을 저하시킨다. 측정결과를 통해서 제안된 안테나가 급전구조로부터 발생되는 기생 리액턴스를 보상할 수 있기 때문에 개선효과를 얻을 수 있었다는 것을 입증하였다. 연구된 안테나는 단순한 구조 때문에 어레이 확장이 쉽게 설계될 수 있다.

• 대한전자공학회논문지TC
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• 제49권4호
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• pp.47-52
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• 2012

본 논문에서는 200 GHz 대역의 시스템에 응용이 가능한 구형도파관 전송선로와 평면 구조인 마이크로스트립 전송선로 구조의 부품들의 상호 신호전달을 위해 프로브 구조의 변환기를 설계하였다. 설계된 변환기는 프로브, 임피던스 변화를 위한 테이퍼구조와 마이크로스트립 구조의 전송선로로 구성된다. Ansoft사의 HFSS 시뮬레이션 툴을 이용하여 프로브의 크기 및 테이퍼의 길이를 변경하여 주파수 특성 변화를 확인하였으며 최적화하였다. 변환기는 특성 검증을 위해 back-to-back 구조로 설계되었으며, 시뮬레이션 결과 186 GHz ~ 210 GHz의 대역폭을 갖으며 전 대역에서 - 0.81 dB 이하의 삽입손실과 -10 dB 이상의 반사손실을 확인하였다.

• 대한조선학회논문집
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• 제60권5호
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• pp.305-319
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• 2023

This study focuses on measuring the relative wave elevation around the KSUPRAMAX-O ship and comparing it with numerical analysis results (potential and computational fluid dynamics). The relative wave elevation is a good indicator of the pressure distribution on the ship's surface, which is affected by the ship's motion, incident waves, and distributed waves. Prior to measuring the relative wave elevation, a comparative test was conducted on resistance type, capacitance type, and ultrasonic type wave probe to measure the relative wave elevation, and it was confirmed that the resistance type wave probe was suitable for measuring the relative wave elevation. A model test was performed at low speed and design speed using resistance type wave probe and compared with the results of numerical analysis result. As for the motion response, it was confirmed that the result of experiments and the result of the numerical analysis were in good agreement. The relative wave elevation showed a similar trend between the experiment and the computational fluid dynamics, but the potential analysis result showed a difference from the experiment in design speed.

• 한국산학기술학회논문지
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• 제10권4호
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• pp.811-817
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• 2009

IT 시스템 기반의 네트워크 환경의 급속한 발전은 지속적인 연구방향의 중요한 이슈의 결과이다. 침입시도 탐지는 관심분야의 하나인 것이다. 최근에 다양한 기술을 기반으로 하는 침입시도탐지들이 제안되고 있으나 이러한 기술은 여러 형태의 침입시도의 패턴 중에 한가지 형태 및 시스템에 적용이 가능한 것이다. 또한 새로운 형태 침입시도를 탐지하지 못하고 있다. 그러므로 새로운 형태를 인식하는 침입탐지 관련 기술이 요구되어 지고 있다. 본 연구에서는 퍼지인식도와 비정상 트래픽 분석을 이용한 네트워크 기반의 침입탐지기법(NePID)을 제안한다. 이 제안은 패킷 분석을 통하여 서비스거부공격과 유사한 침입시도를 탐지하는 것이다. 서비스거부공격은 침입시도의 형태를 나타내며 대표적인 공격으로는 syn flooding 공격이 있다 제안한 기법은 syn flooding을 탐지하기 위하여 패킷정보를 수집 및 분석한다. 또한 피지인식도와 비정상 트래픽 분석을 적용하여 판단모듈의 분석 결과를 토대로 기존의 서비스 거부 공격의 탐지 툴과의 비교분석을 하였으며 실험데이터로는 MIT Lincoln 연구실의 IDS 평가데이터 (KDD'99)를 이용하였다. 시뮬레이션 결과 최대평균 positive rate는 97.094% 탐지율과 negative rate는 2.936%을 얻었으며 이 결과치는 KDD'99의 우승자인 Bernard의 결과치와 유사한 수준의 값을 나타내었다.

• 대한전자공학회:학술대회논문집
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• 대한전자공학회 2000년도 하계종합학술대회 논문집(3)
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• pp.67-70
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• 2000

In a distributed real-time system(DRTS), testing and debugging are difficult and critical procedures since they implies several problems like probe effects, nondeterminism, and complex communication patterns. In this paper, we describe the design and implementation of a real-time monitor for ARM processors which are frequently used for embedded applications. The focus of design is to help users debug real-time programs while minimizing the probe effect. Our monitor provides cross debugging features like down-loading from host, break-point based debugging features, and watch-point debugging features for real-time applications. We developed the debugger for ARM processor and debugger has been used for kernel program.