• Aerospace Engineering and Technology
• /
• v.7 no.1
• /
• pp.115-120
• /
• 2008

The thermistors and AD590 are widely used for temperature measurement in space application. The resistance of thermistor will vary according to the temperature variation therefore the external voltage or current stimulus signal have to be provided to measure resistance variation. Recently high resolution electro optic camera system of satellite requires tight thermal control of the camera structure to minimize the thermal structural distortion which can affects the image quality. In order to achieve $1^{\circ}$(deg C) thermal control requirement, the accuracy of temperature measurement have to be higher than $0.3^{\circ}$(deg C). In this paper, the accuracy of temperature measurement using thermistors is estimated and analyzed.

• KSCE Journal of Civil and Environmental Engineering Research
• /
• v.29 no.4D
• /
• pp.545-553
• /
• 2009

This paper describes the result of study on measurement of displacement of structure by means of non-contacting method, close-range digital photogrammetry using digital camera. To apply close-range digital photogrammetry to displacement measurement of structure, correction of lens distortion that interferes geometrical analysis has been carried out and then measuring displacement was performed on load regulated-rahmen. For enhanced applicability of displacement measurement, MIDAS which is a structural analysis program was used for modeling and the result was taken from comparative analysis. As a result of the study, it is showed that close-range digital photogrammetry could supplement several weaknesses of LVDT and cable displacement meter and, especially, economy in the perspective of measuring time could be realized. Close-range digital photogrammetry using digital camera can be applied to the area where requires visual analysis such as 3D modeling of structure, profile replication of measurement of structure as well as measurement of displacement of structure.

• Journal of the Korea institute for structural maintenance and inspection
• /
• v.12 no.1
• /
• pp.117-126
• /
• 2008

In this paper, it is presented a digital image processing method and the program (Visual C++) to determine the shape of the suspension bridge. To investigate the precision of this method, a suspension bridge is divided into 5, 13 and 19 images, respectively, by using the 6.3M pixels digital camera with 300mm zoom lens. Obtained results of the Kwang-Ahn Grand Bridge by using this method are fairly close to the real precision surveyed data. The accuracy is more improved by increasing the number of divided images of the structure. The total cost, man power and time of field survey by this method presented in this study could be much more reduced and the developed program could be applied with little modification for other structures like cable-stayed bridges, if lens compensation algorithms and program access capabilities are improved.

• International Journal of Contents
• /
• v.10 no.4
• /
• pp.63-68
• /
• 2014

In this paper, we propose a smart system that can optically recognize a music score within a document and can play the music after recognition. Many historic handwritten documents have now been digitalized. Converting images of a music score within documents into digital files is particularly difficult and requires considerable resources because a music score consists of a 2D structure with both staff lines and symbols. The proposed system takes an input image using a mobile device equipped with a camera module, and the image is optimized via preprocessing. Binarization, music sheet correction, staff line recognition, vertical line detection, note recognition, and symbol recognition processing are then applied, and a music file is generated in an XML format. The Music XML file is recorded as digital information, and based on that file, we can modify the result, logically correct errors, and finally generate a MIDI file. Our system reduces misrecognition, and a wider range of music score can be recognized because we have implemented distortion correction and vertical line detection. We show that the proposed method is practical, and that is has potential for wide application through an experiment with a variety of music scores.

• The Journal of the Korea Contents Association
• /
• v.12 no.10
• /
• pp.63-71
• /
• 2012

Depth understanding is important for stereoscopic and various methods including space design and cognitive science should be taken account in contents production. Among them, human scientific engineering such as human factor needs to be touched. More specifically, when the stereoscopic designer determines a binocular disparity, the viewpoint of the camera has to be matched with that of the audience. In this process, the structural problem by the distortion due to the dichoptic error is happened, Therefore, 3D sweetening process based on geometric re-analysis and human scientific engineering to minimize the visual fatigue is significant. This paper analyzes the inconsistency problems of the viewpoint in stereoscopic images, and we produce the stereoscopic image contents based on human factors.

• Proceedings of the KIEE Conference
• /
• 2011.07a
• /
• pp.1934-1935
• /
• 2011

In order for a service robot to perform several tasks, basically autonomous navigation technique such as localization, mapping, and path planning is required. The localization (estimation robot's pose) is fundamental ability for service robot to navigate autonomously. In this paper, we propose a new system for point pattern matching based visual global localization using spot lightings in ceiling. The proposed algorithm us suitable for system that demands high accuracy and fast update rate such a guide robot in the exhibition. A single camera looking upward direction (called ceiling vision system) is mounted on the head of the mobile robot and image features such as lightings are detected and tracked through the image sequence. For detecting more spot lightings, we choose wide FOV lens, and inevitably there is serious image distortion. But by applying correction calculation only for the position of spot lightings not whole image pixels, we can decrease the processing time. And then using point pattern matching and least square estimation, finally we can get the precise position and orientation of the mobile robot. Experimental results demonstrate the accuracy and update rate of the proposed algorithm in real environments.

• Journal of Broadcast Engineering
• /
• v.10 no.1 s.26
• /
• pp.68-76
• /
• 2005

We propose a new type of stereoscopic camera system with a zoom lens module to overcome the backlash for the stability of picture matching and the difficulty of zoom control. This system is designed to control a pair of zoom lens with a rotation lever. In this paper, we present the structural characteristics of our proposed system, and verify that there are no image mismatching at acquired stereo images and the zoom in$\cdot$out is easy to control. In our experiments, we achieve good results that a convergence control is very simple and distortion of images is decreased.

• Journal of Korean Ophthalmic Optics Society
• /
• v.8 no.2
• /
• pp.99-103
• /
• 2003

This paper presents lens optimization of the resolution and the distortion for a four-element lens design. In order to have compact optical system, we used the tele-photo type lens composed of a positive and a negative power elements instead of retro-focus lens. The specifications of optical lens design are the focal length of 7.2 mm, the F/number of 2.8 and the field angle of $54.7^{\circ}C$. The MTF values are higher than 0.5 in the spatial frequency range up to 110 lp/mm for all of the designed object heights. Also, it is expected to fulfill all the requirements of a digital still camera lens and especially suited for building low-cost, compact digital cameras because of the low-profile property of the lens design.

• 한국연소학회:학술대회논문집
• /
• 2005.10a
• /
• pp.120-131
• /
• 2005

The evaporation characteristics of single and multicomponent droplets hanging at the tip of a quartz fiber are studied experimentally at the different environmental conditions under normal gravity. Heptane and Hexadecane are selected as two fuels with different evaporation rates and boiling temperatures. At the first step, the evaporation of single component droplet of both fuels has been examined separately. At the next step the evaporation of several blends of these two fuels, as a binary component droplet, has been studied. The temperature and pressure range is selected between 400 and 700 $^{\circ}C$, and 0.1 and 2.5 MPa, respectively. High temperature environment has been provided by a falling electrical furnace. The initial diameter of droplet was in range of 1.1 and 1.3 mm. The evaporation process was recorded by a high speed CCD camera. The results of binary droplet evaporation show the three staged evaporation. In the the first stage the more volatile component evaporates. The droplet temperature rises after an almost non evaporating period and in the third stage a quasi linear evaporation takes place. The evaporation of the binary droplet at low pressure is accompanied with bubble formation and droplet fragmentation and leads to incomplete microexplosion. The component concentration affects the evaporation behavior of the first two stages. The bubble formation and droplet distortion does not appear at high environment pressure. Nomenclature

• Proceedings of the Korea Contents Association Conference
• /
• 2007.11a
• /
• pp.97-100
• /
• 2007

Recently, there is developed various antenna's models due to increment of wireless communication the need of quantitative study on antenna's measuring technology gets to highlight. In this paper, we propose algorithm of antenna's edge alignment for making automatic measuring system of antenna's characteristics of near-field measurement system of antenna. The proposed algorithm gets the bottom image of antenna from camera, extracts antenna object, and finds the boundary the object. The proposed algorithm calculates distortion of the object using the extracted boundary and the angle to correct this. The proposed algorithm is applied to the standard gain horn antenna. The results show that antenna's object is efficiently extracted and the angle for correcting the error is calculated.