• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 2004년도 ICCAS
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• pp.588-591
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• 2004

In this paper, we propose a ground plane detection algorithm, using a new image processing method (IPD). To extract the ground plane from the color image acquired by monocular camera, we use a new identical pixel detection method (IPD) and an edge detection method. This IPD method decides whether the pixel is identical with the ground plane pixel or not. The IPD method needs the reference area and its performance depends on the reference area size. So we propose the reference area auto-expanding algorithm in accordance with situation. And we evaluated the proposed algorithm by the experiments in the various environments. From the experiments results, we know that the proposed algorithm is efficient in the real indoor environment.

• 전자공학회논문지B
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• 제33B권6호
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• pp.64-72
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• 1996

In this paper, we propose predictive motion estimatin algorithm which can predict motion without additional side information considering spatio-tempral correlatio of motion vector. This method performs motion prediction of current block using correlation of the motion vector for two spatially adjacent blocks and a temporally adjacent block. Form predicted motion, the position of searhc area is determined. Then in this searhc area, we estimate motion vector of current block using block matching algoirthm. Considering spatial an temporal correlation of motion vector, the proposed method can predict motion precisely much more. Especially when the motion of objects is rapid, this method can estimate motion more precisely without reducing block size or increasing search area. Futhrmore, the proposed method has computation time the same as conventional block matching algorithm. And as it predicts motion from adjacent blocks, it does not require additional side information for adjacent block. Computer simulation results show that motion estimation of proposed method is more precise than that of conventioanl method.

• 환경생물
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• 제22권1호
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• pp.1-11
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• 2004

Ecological methods were reviewed through reports such as environmental impact assessment and damage effect of fishery in the Korean watershed. Survey items in marine ecological field were included: phytoplankton, zooplankton, benthic animal, algae, adult fish, egg and juvenile of fish. A standardization of survey method in the field of community ecology was suggested to consider the convenience, Sequency in Use of device, accuracy of data collected from that. It is necessary that spatial data should be sufficiently acquired toy statistical analysis of biodiversity and spatial comparison. Quantitative sampling method must be inevitably adopted based nature of biota and geographical type of the survey area. The same sampling method can make the data compared spatially but can't be applicable in all area. Standardizing survey method should be by no means under certain restriction of study and would become different according to survey environments. The first thing is minutely understanding about ecological character of biota inhabiting in certain area, and then determining survey method.

• 대한수학교육학회지:수학교육학연구
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• 제22권4호
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• pp.495-515
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• 2012

본 연구에서는 평면도형의 넓이에 대한 교사의 교수학적 내용 지식(PCK)을 설문지와 수업 관찰을 통해서 분석하였다. 연구 결과, 다음과 같은 4가지 결론을 얻을 수 있다. (1) PCK의 '수학 내용 지식' 영역에서 교사는 넓이의 개념, 넓이와 길이의 속성 구분을 정확히 이해하고 배열구조를 지도의 대상으로 인식하여야 한다. (2) PCK의 '수학과 교수 방법 및 평가에 대한 지식' 영역에서 교사는 교과 목표를 넓이의 개념 이해와 공식의 이해를 균형적으로 설정하고 평가해야 한다. (3) PCK의 '수학 학습에 대한 학생 이해 지식' 영역에서 교사는 설명 위주의 오류수정 보다 넓이의 개념의 이해에 대한 활동을 제시해야 한다. (4) PCK의 '수학과 수업 상황에 대한 지식' 영역에서 교사는 교과서에 대한 주체적 의식을 가지고 교과서의 활동을 보완하여야 한다.

• Nuclear Engineering and Technology
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• 제32권5호
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• pp.433-445
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• 2000

The interfacial area concentration (IAC) is one of the most important parameters in the two-fluid model for two-phase flow analysis. The IAC can be measured by a local conductivity probe method that uses the difference of conductivity between water and air/steam. The number of sensors in the conductivity probe may be differently chosen by considering the flow regime of two-phase flow. The four sensor conductivity probe method predicts the IAC without any assumptions of the bubble shape. The local IAC can be obtained by measuring the three dimensional velocity vector elements at the measuring point, and the directional cosines of the sensors. The five sensor conductivity probe method proposed in this study is based on the four sensor probe method. With the five sensor probe, the local IAC for a given referred measuring area of the probe can be predicted more exactly than the four sensor probe. In this paper, the mathematical approach of the five sensor probe method for measuring the IAC is described, and a numerical simulation is carried out for ideal cap bubbles of which the sizes and locations are determined by a random number generator.

• 한국정보통신학회논문지
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• 제8권1호
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• pp.80-87
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• 2004

본 논문에서는 RGB 컬러 정보와 퍼지 이진화를 이용하여 차량 번호판의 개별 문자를 추출하는 방법을 제안한다. 제안된 방법은 비 영업용 차량 영상에서 녹색의 분포가 밀집되어 있는 영역들을 번호판의 후보 영역으로 추출하고 번호판의 후보 영역에서 흰색의 밀집도가 높은 부분을 번호판의 영역으로 선택한다. 개별 문자 추출은 추출된 번호판 영역에서 3${\times}$3소벨 마스크를 이용하여 잡음을 제거하고 퍼지 이진화 방법을 적용하여 번호판의 영역을 이진화한 다음에 윤곽선 추적 알고리즘을 적용하여 개별 문자를 추출한다. 제안된 방법을 실제 비 영업용 차량 번호판에 적용한 결과, 기존의 방법보다 번호판 영역에서 개별 문자의 추출률이 개선된 것을 확인하였다.

• Current Optics and Photonics
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• 제1권6호
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• pp.604-612
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• 2017

An effective and precise method using a scanning white-light interferometer (SWLI) for three-dimensional surface measurements, in particular for roughness measurements, has been proposed. The measurement of a microscopically sloped area using an interferometer has limitations, due to the numerical aperture of the lens. In particular, for roughness measurements, it is challenging to obtain accurate height data for a sloped area using the interferometer, due to diffraction of the light. Owing to these optical limitations of the interferometer for roughness measurements, the Ra measurements performed using an interferometer contain errors. To overcome the limitations, we propose a method consisting of the following two steps. First, we evaluate the height data and set the invalid height area to be blank, using the characteristics of the modulus peak, which has a low peak value for signals that have low reliability in the interferogram. Next, we interpolate the blank area using the adjacent reliable area. Rubert roughness standards are used to verify the proposed method. The results obtained by the proposed method are compared to those obtained with a stylus profilometer. For the considered sinusoidal samples, Ra ranges from $0.053{\mu}m$ to $6.303{\mu}m$, and we show that the interpolation method is effective. In addition, the method can be applied to a random surface where Ra ranges from $0.011{\mu}m$ to $0.164{\mu}m$. We show that the roughness results obtained using the proposed method agree well with profilometer results. The $R^2$ values for both sinusoidal and random samples are greater than 0.995.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• 제31권1호
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• pp.82-88
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• 2005

Treatment methods of mandibular condylar fracture were conservative and surgical method. Surgical method of mandibular high condylar fracture was very difficult because approach and internal fixation of small size fracture fragment were difficult. So there is a tendency to select conservative method over surgical method for guiding a stable occlusion and avoiding TMJ disorder and growth disturbance, minimizing pain and deviation during function. But, in case of mandibular high condylar fracture patient who has no biting teeth on posterior teeth area, guiding a stable occlusion and conservative functional treatment were very difficult. In this case, patient was 62years old male. He had fracture of mandibular symphysis, right mandibular body, left mandibular high condyle. We treated the patient for mandibular symphysis and right mandibular body fracture area with surgical method. But left mandibular high condylar fracture area was difficult to treat with surgical method. So we selected a conservative functional method on left mandibular high condylar fracture area. We intended recovery of vertical dimension and stable occlusion with implantation of immediate provisional implant on maxillar and mandibular posterior teeth area, and temporary crown. And then patient did mandibular functional movement and his mandibular function was recoverd.

• Nuclear Engineering and Technology
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• 제52권11호
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• pp.2471-2478
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• 2020

Pumps are essential machinery in the various industries. With the development of high-speed and large-scale pumps, especially high energy density, high requirements have been imposed on the vibration and noise performance of pumps, and cavitation is an important source of vibration and noise excitation in pumps, so it is necessary to improve pumps cavitation performance. The modern pump optimization design method mainly adopts parameterization and artificial intelligence coupling optimization, which requires direct correlation between geometric parameters and pump performance. The existing cavitation performance calculation method is difficult to be integrated into multi-objective automatic coupling optimization. Therefore, a fast prediction method for pump cavitation performance is urgently needed. This paper proposes a novel cavitation prediction method based on impeller pressure isosurface at single-phase media. When the cavitation occurs, the area of pressure isosurface S_iso increases linearly with the NPSH_a decrease. This demonstrates that with the development of cavitation, the variation law of the head with the NPSH_a and the variation law of the head with the area of pressure isosurface are consistent. Therefore, the area of pressure isosurface S_iso can be used to predict cavitation performance. For a certain impeller blade, since the area ratio R_s is proportional to the area of pressure isosurface S_iso, the cavitation performance can be predicted by the R_s. In this paper, a new cavitation performance prediction method is proposed, and the feasibility of this method is demonstrated in combination with experiments, which will greatly accelerate the pump hydraulic optimization design.

• Journal of Positioning, Navigation, and Timing
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• 제8권4호
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• pp.183-192
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• 2019

In fingerprint-based wireless positioning, it is necessary to establish a DB of the unmeasured area. To this end, a method of estimating the position of a base station based on a signal propagation model, and a method of estimating the information of the received signal in the unmeasured area based on the estimated position of the base station have been investigating. The purpose of this paper is to estimate the position of the base station using the measured information and to analyze the performance of the positioning. Vehicles equipped with a GPS receiver and signal measuring equipment travel the service area and acquire location-based Reference Signal Received Power (RSRP) measurements. We propose a method of estimating the position of the base station using the measured information. And the performance of the proposed method is analyzed on a simulation basis. The simulation results confirm that the accuracy of the positioning is affected by the measured area and the Dilution of Precision (DOP), the accuracy of the position information obtained by the GPS receiver, and the errors of the signal included in the RSRP. Based on the results of this paper, we can expect that the position of the base station can be estimated and the DB of the unmeasured area can be constructed based on the estimated position of the base stations and the signal propagation model.