• Ecology and Resilient Infrastructure
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• 제8권4호
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• pp.204-211
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• 2021

본 연구에서는 3차원 지상 라이다 스캐너를 통해 수집되는 포인트 클라우드를 활용하여 식생의 정보를 수집하였으며, 수집된 데이터를 기반으로 객체를 재구현하여 물리적 형상을 분석하였다. 이를 위해 원시 데이터의 필터링 단계별 최적의 데이터를 구축하였으며, 구축된 데이터를 활용하여 실제 부피와 Alpha Shape 및 Voxel 기법을 활용한 부피 산정 결과를 산정한 후 각각 비교하였다. 분석 결과, Alpha Shape를 적용하여 부피를 산정한 경우 데이터 필터링과 관계없이 실제 부피보다 과다 산정되는 것으로 나타났다. 또한 Voxel 기법을 활용할 경우 8차 필터링 후 실제 부피와 가장 유사한 것으로 나타났으며, 이후 필터링이 진행될수록 실제 부피에 비해 과소 산정되는 것을 알 수 있었다. 따라서 포인트 클라우드를 활용하여 객체를 재구현 할 경우, 대상이 되는 객체의 복잡한 형상으로 인한 내부 공극을 고려해야 하며, 필터링 과정에서 최적의 데이터 구축을 위한 필터링 과정에 반드시 주의할 필요가 있다.

• 한국문헌정보학회지
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• 제33권4호
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• pp.65-83
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• 1999

본 연구는 서지적으로 관련된 저작을 연결하고, 특정 저자의 상이한 이름이나 특정 저작의 상이한 서명을 직접 접근점으로 사용하기 위해, 전거표목을 배제한 시스템을 제안하고 있다. 이를 위해, 특정 접근점과 그 이형(異形)에 대한 참조와 이들간의 서지적 관계유형을 제공할 수 있는 레코드의 형식을 개발하여 참조시스템을 제안하였다. 아울러 전통적인 표목 및 상호참조의 기능을 본 시스템과 관련하여 검토하였다.

• 센서학회지
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• 제33권2호
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• pp.63-69
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• 2024

A novel method for measuring hydrogen concentration is introduced, along with its working principle and a novel detection algorithm. This configuration requires no additional reference compartment for potentiometric electrochemical measurements; therefore, it is the most suitable for measuring dissolved hydrogen in the liquid phase. The sensor's electromotive force saturates at a certain point, depending on the hydrogen concentration during the heating process of the sensor operation. This dynamic temperature scanning method provides higher sensitivity than the constant temperature measurement method.

• Journal of Positioning, Navigation, and Timing
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• 제12권1호
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• pp.83-89
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• 2023

The Korea Augmentation Satellite System (KASS) system is a Satellite Based Augmentation System (SBAS) under development to provide APV-I SBAS service in the Republic of Korea. The KASS ground segment generates correction and integrity information for GPS measurements of KASS users using the accurate positions of KASS Reference Station (KRS) antenna phase centers. For this reason, the accuracy of KRS reference points through geodetic survey campaigns is one of the important factors for providing the KASS service in compliance with the required navigation performance. In order to obtain accurate positions, two geodetic survey campaigns were performed at several reference points, such as Mark, Center of Mast at Ground Level (CMGL), and Center of Hole in Top Plate (CHTP), of each KRS site using three different survey methods, the Virtual Reference Station (VRS), Flächen Korrektur Parameter (FKP), and raw data post-processing methods. By comparing and analyzing the results, the computed coordinates of the reference points were verified and Antenna Phase Center (APC) positions were calculated using KRS Antenna Reference Point (ARP) data, and the first KASS Site Acceptance Test (SAT#1) was performed successfully using the verified APC coordinates. After the first site survey activities, the KASS operators should maintain the coordinates with the required performance such that the overall KASS navigation performance commitment is guaranteed during the lifetime of 15 years. Therefore, the maintenance plan for the KRS antenna coordinates should be developed before the commissioning of KASS operation planned after 2023. Therefore, this paper presents a geodetic survey method selected for the maintenance activities and provides the rationale for using this method.

• IEIE Transactions on Smart Processing and Computing
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• 제5권6호
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• pp.383-389
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• 2016

This paper presents a novel automatic white balance (AWB) algorithm for consumer imaging devices. While existing AWB methods require reference white patches to correct color, the proposed method performs the AWB function using only an input image in two steps: i) white point detection, and ii) color constancy gain computation. Based on the dark channel prior assumption, a white point or region can be accurately extracted, because the intensity of a sufficiently bright achromatic region is higher than that of other regions in all color channels. In order to finally correct the color, the proposed method computes color constancy gain values based on the Y component in the XYZ color space. Experimental results show that the proposed method gives better color-corrected images than recent existing methods. Moreover, the proposed method is suitable for real-time implementation, since it does not need a frame memory for iterative optimization. As a result, it can be applied to various consumer imaging devices, including mobile phone cameras, compact digital cameras, and computational cameras with coded color.

• 한국유체기계학회 논문집
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• 제15권3호
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• pp.19-24
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• 2012

Propeller shall have high efficiency and improved aerodynamic characteristics to get the thrust to fly at high speed for the turboprop aircraft. That is way Clark-Y airfoil which is used to conventional 1600kW class aircraft propeller is selected as a blade airfoil. Adkins method is used for aerodynamic design and performance analysis with respect to the propeller design point. Adkins method is based on the vortex-blade element theory which design the propeller to satisfy the condition for minimum energy loss. propeller geometry is generated by varying chord length and pitch angle at design point of turboprop aircraft. The propeller design results indicate that is evaluated to be properly constructed, through analysis of propeller aerodynamic characteristics using the Meshless method and MRF, SM method.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2005년도 추계학술대회논문집
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• pp.844-848
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• 2005

A method to predict the strain responses from the measurements of displacement responses is considered. The method uses a transformation matrix which is composed of a displacement modal matrix and a strain modal matrix. The method can predict strains at points where displacements are not measured as well as at displacement measuring points. One of the drawbacks of the strain prediction method is that the displacement responses must be measured at many points on a structure simultaneously. This difficulty can be overcome by measuring the FRFs between displacements at a reference point and other point in sequence with a two channel measuring equipment This procedure is based on the assumption that the characteristics of excitation applied to the structure do not vary with time.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1989년도 추계학술대회 논문집 학회본부
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• pp.421-425
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• 1989

This paper present a algorithm for determination of the frontal QRS axis. Determination of electrical QRS axis helps In the differential diagnosis of wide QRS tachycardia and of hemiblock and In the localization of an accessory pathway. At first detecting R-point data and S-point data and two data is sumed and this data is determind such as positive or negative. Reference data is calculated by 9-point derivertives that is less affected by noise. Secondly, using data of lead2 calculate a morphology, this value is threshold for executing determination algorithm. This process is main body of this algorithm. As this algorithm have a six pattern of the axis that coded by minnesota ending method, the axis is determined more precisely than any other algorithm using 3 leads and affirm a relation of a axis and hemiblock and tachycardia.

• 대한전자공학회:학술대회논문집
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• 대한전자공학회 2000년도 ITC-CSCC -1
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• pp.446-449
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• 2000

A direct RTI(Rotation and translation invariant) fingerprint identification is proposed using the GCMs(generalized complex moments) and Gabor filter-based features from the grey level fingerprint around core point. The core point is located as reference point for the translation invariant matching. And its symmetry axis is detected for the rotation invariant matching from its neighboring region centered at the core point. And then, fingerprint is divided into non-overlapping blocks with respect to the core point and, in contrast to minutiae-based method using various processing steps, features are directly extracted from the blocked grey level fingerprint using Gabor filter, which provides information contained in a particular orientation in the image. The Proposed fingerprint identification is based on the Euclidean distance of the corresponding Gabor features between the input and the template fingerprint. Experiments are conducted on 300 ${\times}$ 300 fingerprints obtained from the CMOS sensor with 500 dpi resolution, and the proposed method could obtain 97% identification rate.

• Journal of Power Electronics
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• 제3권4호
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• pp.205-214
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• 2003

This paper proposes a simple control strategy based on the discontinuous PWM (DPWM) to balance the DC-link voltage of three-level neutral-point-clamped (NPC) inverter at low modulation index. It introduces new DPWM methods in multi-level inverter and one of them is used for balancing the DC-link voltage. The current flowing in the neutral point of the DC-link causes the fluctuation of the DC-link voltage of the NPC inverter. The proposed DPWM method changes the path and duration time of the neutral point current, which makes the overall fluctuation of the DC-link voltage zero during a sampling time of the reference voltage vector. Therefore, by using the proposed strategy, the voltage of the DC-link can be balanced fairly well and the voltage ripple of the DC-link is also reduced significantly. Moreover, comparing with conventional methods which have to perform the complicated calculation, the proposed strategy is very simple. The validity of the proposed DPWM method is verified by the experiment.