• 한국전산구조공학회논문집
• /
• 제35권5호
• /
• pp.259-266
• /
• 2022

본 논문에서는 프리팹 구조물의 품질관리를 위한 딥러닝 및 비전센서 기반의 조립 성능 평가 모델을 개발하였다. 조립부 검출을 위해 인코더-디코더 형식의 네트워크와 수용 영역 블록 합성곱 모듈을 적용한 딥러닝 모델을 사용하였다. 검출된 조립부 영역 내의 볼트홀을 검출하고, 볼트홀의 위치 값을 산정하여 k-근접 이웃 기반 모델을 사용하여 조립 품질을 평가하였다. 제안된 기법의 성능을 검증하기 위해 조립부 모형을 3D 프린팅을 이용하여 제작하여 조립부 검출 및 조립 성능 예측 모델의 성능을 검증하였다. 성능 검증 결과 높은 정밀도로 조립부를 검출하였으며, 검출된 조립부내의 볼트홀의 위치를 바탕으로 프리팹 구조물의 조립 성능을 5% 이하의 판별 오차로 평가할 수 있음을 확인하였다.

• 원예과학기술지
• /
• 제30권3호
• /
• pp.270-277
• /
• 2012

Greenhouse industry has been growing in many countries due to both the advantage of stable year-round crop production and increased demand for fresh vegetables. In greenhouse cultivation, $CO_2$ concentration plays an essential role in the photosynthesis process of crops. Continuous and accurate monitoring of $CO_2$ level in the greenhouse would improve profitability and reduce environmental impact, through optimum control of greenhouse $CO_2$ enrichment and efficient crop production, as compared with the conventional management practices without monitoring and control of $CO_2$ level. In this study, a mathematical model was developed to estimate the $CO_2$ emission from soil as affected by environmental factors in greenhouses. Among various model types evaluated, a linear regression model provided the best coefficient of determination. Selected predictor variables were solar radiation and relative humidity and exponential transformation of both. As a response variable in the model, the difference between $CO_2$ concentrations at the soil surface and 5-cm depth showed are latively strong relationship with the predictor variables. Segmented regression analysis showed that better models were obtained when the entire daily dataset was divided into segments of shorter time ranges, and best models were obtained for segmented data where more variability in solar radiation and humidity were present (i.e., after sun-rise, before sun-set) than other segments. To consider time delay in the response of $CO_2$ concentration, concept of time lag was implemented in the regression analysis. As a result, there was an improvement in the performance of the models as the coefficients of determination were 0.93 and 0.87 with segmented time frames for sun-rise and sun-set periods, respectively. Validation tests of the models to predict $CO_2$ emission from soil showed that the developed empirical model would be applicable to real-time monitoring and diagnosis of significant factors for $CO_2$ enrichment in a soil-based greenhouse.

• Journal of the Korean Society for Industrial and Applied Mathematics
• /
• 제10권2호
• /
• pp.67-80
• /
• 2006

본 논문에서는 스테레오 비전을 이용하여 기존의 포인팅 디바이스인 마우스를 대신할 새로운 포인팅 디바이스 방법을 제안 한다. 제안한 방법은 기존의 인식 장비들이 가진 마커에 의한 움직임 제약과 고가 장비의 단점을 극복하기 위해 컴퓨터 비전을 이용한다. 즉, 사람이 시각을 통해 정보를 인식하는 것과 동일하게 컴퓨터의 영상 정보를 이용하여 실시간으로 영상내의 컬러 영역의 분할을 통해 물체의 위치를 추적 및 정합하고 이의 위치를 스테레오 기하학 정보로부터 계산하여 포인팅 동작을 수행한다.

• International Journal of Fuzzy Logic and Intelligent Systems
• /
• 제2권3호
• /
• pp.227-230
• /
• 2002

A new iris segmentation and recognition method is described. Combining a statistical classification and elastic boundary fitting, the iris is first segmented robustly and accurately. Once the iris is segmented, one-dimensional signals are computed in the iris and decomposed into multiple frequency bands. Each decomposed signal is approximated by a piecewise linear curve connecting a small set of node points. The node points represent features of each signal. The similarity measture between two iris images is the normalized cross-correlation coefficients between simplified signals.

• 한국의류학회지
• /
• 제24권7호
• /
• pp.953-963
• /
• 2000

This study intended to analyse the factors of brand image and brand image positioning of domestic 20’s female apparel(formal wear) among the consumer groups segmented by benefits sought in apparel and to provide marketing strategy of brand image. The subject of this study were 605 working women in their 20’s living in seoul, and the model sampling was done by convenienced sampling method based on the subjects age and occupation. Survey based on references and former studies was used. and statistical methods such as frequency, percentage, mean, factor analysis, preference regression were applied. The results of this study were as follows. 1. The factor structures of brand image were classified into symbolism/aesthetics, and practicality. 2. Perception, ideal preference vector, and brand preference of brand image were proven to be significantly different among the four segmented consumer groups.

• Journal of Astronomy and Space Sciences
• /
• 제32권3호
• /
• pp.269-279
• /
• 2015

Future space missions will have larger telescopes in order to look deeper into space while improvising on spatial resolution. The primary mirrors for these telescopes will be so large that using a monolithic mirror will be nearly impossible because of the difficulties associated with its fabrication, transportation, and installation on a launch vehicle. The feasibility of launching these huge mirrors is limited because of their small launch fairing diameter. The aerodynamic shape of the fairing requires a small diameter, but the height of the launch vehicle, which is available for designers to utilize, is larger than the fairing diameter. This paper presents the development of an axial deployment mechanism based on the screw jack principle. The mechanism was designed and developed, and a prototype was constructed in order to demonstrate a lab model.

• 대한원격탐사학회:학술대회논문집
• /
• 대한원격탐사학회 1998년도 Proceedings of International Symposium on Remote Sensing
• /
• pp.246-251
• /
• 1998

This paper proposes a new building segmentation method from 1m resolution imagery using an Active Contour Model, known as "Balloons". The original balloons, which was designed by Cohen(Cohen, 1991) to extract features from medical images, are modified for building segmentation. The proposed method consists of two phases. Firstly, building boundaries are extracted by balloons with a given position on buildings from an operator. Since balloons actively adjust their shapes according to the boundaries, there is no more shape limitations on detecting buildings. Secondly, buildings are segmented by connecting the corners detected from the building boundaries, because most buildings, which are man-made objects, are effectively described by polygons. The test results show that most buildings are segmented efficiently and easily. The proposed method is new and timely as 1m resolution spaceborne imagery will be available in the very near future. The proposed method can be used fur operational building segmentation from such imagery.

• 한국방송∙미디어공학회:학술대회논문집
• /
• 한국방송공학회 1998년도 Proceedings of International Workshop on Advanced Image Technology
• /
• pp.23-28
• /
• 1998

The goal of this research is to describe relations between impressions and elements in an image (i.e. color, texture and contours). Adequate image segmentation technique to extract these elements is required. We think that a sketch and a realistic painting are examples of optimal segmented images for our purpose because brush strokes are seem to be segmented areas and realistic paintings should remain the same impression as the model. For the reason, in this paper the segmentation technique which can create realistic painting-like segmentation is exploited. It is shown that the realistic painting-like segmentation is suitable for analyzing images.

• 대한전자공학회:학술대회논문집
• /
• 대한전자공학회 2006년도 하계종합학술대회
• /
• pp.259-260
• /
• 2006

Since audio speech recognition is affected by noise in real environment, visual speech recognition is used to support speech recognition. For the visual speech recognition, this paper suggests the extraction of lip-feature using two types of image segmentation and reduced ASM. Input images are transformed to YCbCr based images and lips are segmented using the contrast of Y/Cb/Cr between lip and face. Subsequently, lip-shape model trained by PCA is placed on segmented lip region and then lip features are extracted using ASM.

• 대한전기학회:학술대회논문집
• /
• 대한전기학회 2000년도 추계학술대회 논문집 학회본부 B
• /
• pp.277-279
• /
• 2000

This paper proposes two kinds of the eddy current brake which uses permanent magnet. The one, like multipolar excitation consists of hexahedron shape of a segmented permanent magnetic and iron situated in the air-gap. The other, like multipolar excitation consists of only a segmented permanent magnetic. We use a finite element method to compute the flux distribution in the model. Also, we use the Galerkin-FEM with linear interpolation function may oscillate between the adjacent nodes to calculate the braking and attraction force. The advantages of the Halbach array are discussed.