• 대한전기학회:학술대회논문집
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• 대한전기학회 2007년도 심포지엄 논문집 정보 및 제어부문
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• pp.86-88
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• 2007

In the semiconductor manufacturing industry, the heterodyne laser interferometer plays as an ultra-precise measurement system. However, the heterodyne laser interferometer has some unwanted nonlinearity error which is caused from frequency-mixing. This is an obstacle to improve the measurement accuracy in nanometer scale. In this paper we propose a compensation algorithm based on RLS(recursive least square) method and artificial intelligence method, which reduce the nonlinearity error in the heterodyne laser interferometer. With the capacitance displacement sensor we get a reference signal which can be transformed into the intensity domain. Using the back-propagation Neural Network method, we train the network to track the reference signal. Through some experiments, we demonstrate the effectiveness of the proposed algorithm in measurement accuracy.

• 동력기계공학회지
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• 제11권1호
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• pp.28-32
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• 2007

This research proposed that development of wireless condition monitoring system using WLAN network. It offers the prospect of improved performance that removed a current a coaxial cable and reduced overall cost of condition monitoring. Recently, there is an interesting concern for wireless system as an infrastructure technology construct ubiquitous computing environment in the future. High performance computing board makes minimization with integrate of a various functions which support wireless LAN network. Instead of wired coaxial cable using measurement system in industry, wireless LAN network assists industry automation and engineer's convenience. Developed system adapted wireless LAN network on shipboard with engine room and deck house, it also executes wireless measurement test on 8500TEU containership.

• 대한임베디드공학회논문지
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• 제17권3호
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• pp.177-183
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• 2022

To measure the size and weight of the fish, we developed an automatic fish size measurement system using a deep neural network, where the YOLO (You Only Look Once)v3 model was used. To detect fish, an IP camera with infrared function was installed over the fish pool to acquire image data and used as input data for the deep neural network. Using the bounding box information generated as a result of detecting the fish and the structure for which the actual length is known, the size of the fish can be obtained. A GUI (Graphical User Interface) program was implemented using LabVIEW and RTSP (Real-Time Streaming protocol). The automatic fish size measurement system shows the results and stores them in a database for future work.

• 한국전기전자재료학회논문지
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• 제18권10호
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• pp.960-964
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• 2005

In this paper, we dealt with a partial discharge(PD) measurement method that has been accepted as an effective and non-destructive technique to estimate insulation performance of low-voltage electric and electronic devices. The PD measurement system Is composed of a coupling network, a low noise amplifier, and associated electronics. h shielded box Is adopted to make a better measurement environment against around noise. A low cut-off frequency of the coupling network estimated by a sinusoidal wave input was 125 kHz (-3 dB). Calibration tests on laboratory set-up have shown that the PD measurement system has a stable sensitivity of 10 mV/pC. In an application test oil a low-voltage three phase Induction motor (5 HP), we could detect 0.53 pC level of partial discharge at the applied voltage of AC 650 $V_{peak}$.

• 한국컴퓨터정보학회논문지
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• 제15권10호
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• pp.137-145
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• 2010

본 논문은 USN(Ubiquitous Sensor Network) 기술 기반의 적외선 센서를 사용한 비접촉식 식물 생장 측정 시스템을 제안한다. 제안된 시스템은 식물 생장을 측정할 때 식물의 생장 피해를 줄이기 위하여 비접촉 센서를 사용하였다. 이 시스템은 직경, 단면적, 비대 형상과 같은 식물 생장 요소를 실시간 비접촉 방식으로 측정할 수 있다. 측정된 데이터는 센서 네트워크 기술을 사용하여 원격 서버까지 전송되고, 서버에서 저장 및 분석되며, 최종적으로 분석된 데이터는 사용자에게 제공될 수 있도록 구성하였다. 본 논문에서 제안된 식물 생장 측정시스템은 측정 방식과 장치에 비접촉 적외선 센서를 사용하여 설계 및 구현을 하였다. 그리고 시스템의 성능은 필드에서 측정 실험을 통하여 검증해 보았다.

• 한국통신학회논문지
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• 제39C권6호
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• pp.482-489
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• 2014

본 논문은 IEEE 802.11 환경에서 새로운 AP를 탐색하기 위한 네트워크 스캐닝의 기존 방식을 802.11k의 Measurement Pilot을 활용하여 개선하는 새로운 알고리즘을 제안한다. 그리고 제안한 알고리즘과 종래의 알고리즘을 시뮬레이션 환경에서 비교하여 분석한다. 일반적인 IEEE 802.11을 사용하는 기기들은 탐색 시간이 짧다는 장점을 갖는 능동 탐색(Active Scan)방식을 활용한다. 하지만 이 방식은 수동 탐색(Passive Scan) 방식에 비해 많은 전력사용을 필요로 한다. 본 논문에서 제안하는 탐색 알고리즘은 IEEE 802.11k에서 활용되는 비컨(Beacon)보다 짧은 주기를 갖는 Measurement Pilot을 활용하여 수동 탐색과 능동 탐색의 장점을 취합하여 전력사용을 줄인다.

• ETRI Journal
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• 제26권1호
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• pp.27-37
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• 2004

The architecture in a differentiated services (DiffServ) network is based on a simple model that applies a per-class service in the core node of the network. However, because the network behavior is simple, the network structure and provisioning is complicated. If a service provider wants dynamic provisioning or a better bandwidth guarantee, the differentiated services network must use a signaling protocol with QoS parameters or an admission control method. Unfortunately, these methods increase the complexity. To overcome the problems with complexity, we investigated scalable dynamic provisioning for admission control in DiffServ networks. We propose a new scalable $qDPM^2$ mechanism based on a centralized bandwidth broker and distributed measurement-based admission control and movable boundary bandwidth management to support heterogeneous QoS requirements in DiffServ networks.

• 지식정보인프라
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• 통권7호
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• pp.134-140
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• 2001

To know about the performance of KREONET, we installed an active network performance measurement tool, PingER. For customization, we modified its architecture and some codes. Although this customization is a minor change of PingER, it gives much benefit and convenience for both operators and users. Using PingER, we can measure the effect of the STAR TAP link. The new networking through the link is a little bit slower than the previous networking. But the new link shows far fewer packet losses and provides more reliable networking.

• 한국전자파학회논문지
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• 제28권2호
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• pp.85-96
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• 2017

본 논문에서는 6-포트 회로망을 이용한 잡음파라미터 측정방법의 측정 주파수 대역을 확장하기 위한 2~18 GHz 광대역 6-포트 회로망을 설계 및 제작하였다. 광대역 6-포트 회로망을 설계하기 위해서 광대역 특성을 가지는 윌킨슨 전력분배기와 방향성 결합기를 설계하였다. 윌킨슨 전력분배기는 3단 구조로 설계하여 광대역 특성을 구현하였다. 방향성 결합기는 3단 구조 및 다층기판을 활용한 slot-coupled 구조로 설계하여 광대역 특성을 구현하였다. 설계된 광대역 전력분배기와 결합기를 이용하여 광대역 6-포트 회로망을 설계 및 제작하였다. 2~18 GHz 대역에서 제작된 6-포트 회로망의 측정결과는 잡음 파라미터 측정방법에 적용 가능한 특성을 보였다.

• 한국대기환경학회지
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• 제23권6호
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• pp.689-698
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• 2007

Particular attention is paid to the validity of PM-10 measurement using beta attenuation method. In this study, the inter-comparison studies were undertaken for PM-10 sampler with different measuring methods. The three beta attenuation monitoring instruments (BAM1020, FH C-14, and DIGS-150) and filter based gravitational method using High Volume Air Sampler were collocated and mass concentrations were compared from August to November, 2006. The results of the investigation show that beta attenuation monitoring instruments are comparable with gravitational method within 10% of measurement error. For specific conditions under high humidity and high concentrations, the inter-comparison results also showed a relatively good agreement and this can be explained as the effect of inlet heating of beta attenuation instrument. Subsequently, this study shows that beta attenuation monitoring instruments can be equivalently used with reasonable validity when compared gravimetric method.