• Journal of IKEEE
• /
• v.18 no.4
• /
• pp.603-611
• /
• 2014

When image sensor and lens are fixed on the module, mechanical errors often induce tilt, rotation, or narrow field-of-view of the acquired image. Therefore, the optical characteristics of image sensor modules should be tested by test equipments. This paper explains how to test the optical characteristics of images sensors. It also proposes the standardized description methods of optical characteristics tests which are similar with those of image acquisition characteristics tests. The proposed method helps the test equipments to perform image acquisition characteristics tests and optical characteristics tests together.

• The Korean Journal of Nuclear Medicine Technology
• /
• v.16 no.1
• /
• pp.3-7
• /
• 2012

Purpose : In myocardial perfusion SPECT, the type of orbit (circular vs. body contouring) that affect the image quality is still on the debate. Presently in the nuclear medicine field, the body contouring orbit acquisition is widely used to improve the image quality on the myocardial perfusion SPECT. But in case of body contouring acquisition using the vertical method with dual detect machine, there is a tendency of increasing the radius. In this research, we compared body contouring orbit acquisition with circular orbit acquisition, so we suggest ideal method that reduces the radius for improving image quality. Materials and Methods : Phantom and clinical studies were performed. The anthropomorphic torso phantom was made on equally with counts from patient's body. The study was performed under six different conditions. To compare image quality according to the radius, we increased radius sequentially per step during circular orbit acquisition. On the other hand, sensors that protect a collision and reduce the radius automatically were used to acquire image during body contouring orbit acquisition. So we compared FWHM value of apex. In clinical studies, we analyzed the 40 patients who were examined by Tl-201 gated myocardial perfusion SPECT in department of nuclear medicine at Asan Medical Center in August 2011. To acknowledge the differences according to the radius, we acquired the results two times using circular orbit acquisition and body contouring orbit acquisition. Results : In phantom study, we analyzed that increase of radius resulted in changes of FWHM value. It was 5.41, 6.24, 6.33, 6.42, 6.93 mm. On the other hand, using the body contouring orbit acquisition, FWHM value was 6.23 mm. In clinical study, difference of average radius between two methods was 2.5 cm (circular orbit acquisition was more close to patients). Conclusion : Through the experiments using Anthropomorphic torso phantom and patients data, we found that FWHM value of circular orbit acquisition was lower than body contouring orbit acquisition. As a result, if the difference of average radius exists approximately 3 cm, circular orbit type acquisition is better than body contouring type acquisition. But clinical investigation is only aimed to average radius, so it needs more investigation in comparison of patient's image.

• Journal of the Architectural Institute of Korea Structure & Construction
• /
• v.34 no.10
• /
• pp.11-18
• /
• 2018

In this study, the cross-sectional image has been acquired to evaluate the aggregate distribution affecting quality of lightweight aggregate concrete, and through the binarization method, the study is to calculate the aggregate area of upper and lower sections to develop the method to assess the aggregate distribution of concrete. The acquisition of cross-section image of concrete for the above was available from the cross-sectional photography of cleavage tension of a normal test specimen, and an easily accessible and convenient image analysis software was used for image analysis. As a result, through such image analyses, the proportion of aggregate distribution of upper and lower sections of the test specien could be calculated, and the proportion of aggregate area U/L value of the upper and lower regions of concrete cross-section was calculated, revealing that it could be used as the comprehensive index of aggregate distribution. Moreover, through such method, relatively easy image acquisition methods and analytic methods have been proposed, and this indicated that the development of modeling to assess aggregate distribution quantitatively is available. Based on these methods, it is expected that the extraction of fundamental data to reconsider the connectivity with processes in concrete will be available through quality assessment of quantitative concrete.

• Proceedings of the IEEK Conference
• /
• 2002.06e
• /
• pp.223-226
• /
• 2002

Data Acquisition System of Cargo System using a large output X-ray in harbors is usually composed of Detector, Analog Board, Digital Board, Master Board, Backplane Board and Image Construction System. In this paper we have made an image of material in container-box with Data Acquisition System and studied mainly a configuration method and principle to each part of Data acquisition system.

• Korean Institute of Interior Design Journal
• /
• v.20 no.1
• /
• pp.138-145
• /
• 2011

This study analyzed the time to understand the space and the contents of information to be memorized in the indoor space. Understanding the space and examining the memory will not only provide the basic data on which visual activities occur in user's perceiving the designed space but also expand the activity range of interior designer. The summary of the study results is as follows: First, with respect to gender difference, the results showed that males grasped the space in a relatively shorter time. Females showed more concentrated distribution range than males. Second, as for the proper time by accumulative sum across time, the results showed that it increased continuously until V time zone(120~150 seconds), it decreased rapidly after the V zone, which indicated that the proper gazing time for the indoor space as the target of this study is less than 150 seconds(effective gazing time). Third, in terms of efficiency of information acquisition, the results suggested that "60~90 seconds" are the effective time for acquiring the greatest amount of information. Fourth, regarding the information acquisition method, males were approximately 4.1%~0.1% lower in the evaluation through phrase and image. The evaluation of subjects through phrase than image was connected to more accurate information acquisition.

• Journal of the Korea Institute of Military Science and Technology
• /
• v.22 no.5
• /
• pp.590-598
• /
• 2019

Aerial photographs taken by an image sensor fixed on a flight body, e.g. without a gimbal, are generally distorted according to its attitude, altitude and angle of view in flight. This can result in a significant difficulty of analyzing geometric information which should be integrated for numerous still frames. In this study, a simulation method of observation performance that uses geometric relationships between navigation data and image data is suggested, and this method is shown to be very useful for easily examining the integrated information such as the total range of photography, the time of target acquisition, etc.

• Journal of Astronomy and Space Sciences
• /
• v.15 no.1
• /
• pp.183-196
• /
• 1998

The Synthetic Aperture Radar(SAR) image and the Digital Elevation Model(DEM) of an target area are put into use to generate three dimensional image map. An method of image map generation is explained. The orbit and attitude determination of satellite makes it possible to model signal acquisition configuration precisely, which is a key to mapping image coordinates to geographic coordinates of concerned area. An application is made to RADARSAT in the purpose of testing its validity. To determine the orbit, zero Doppler range is used. And to determine the attitude, Doppler centroid frequency, which is the frequency observed when target is put in the center of antenna's view, is used. Conventional geocoding has been performed on the basis of direct method(mapping image coordinates to geographic coordinates), but in this reserch the inverse method(mapping from geographic coordinates to image coordinates) is taken. This paper shows that precise signal acquisition modeling based on the orbit and attitude determination of satellite as a platform leads to a satellite-centered accurate geocoding process. It also shows how to model relative motion between space-borne radar and target. And the relative motion is described in ECIC(earth-centered-initial coordinates) using Doppler equation and signal acquisition geometry.

• Korean Journal of Remote Sensing
• /
• v.21 no.3
• /
• pp.229-242
• /
• 2005

Photogrammetry is a current method of GIS data acquisition. However, as a matter of fact, a large manpower and expenditure for making detailed 3D spatial information is required especially in urban areas where various buildings exist. There are no photogrammetric systems which can automate a process of spatial information acquisition completely. On the other hand, LiDAR has high potential of automating 3D spatial data acquisition because it can directly measure 3D coordinates of objects, but it is rather difficult to recognize the object with only LiDAR data, for its low resolution at this moment. With this background, we believe that it is very advantageous to integrate LiDAR data and stereo CCD images for more efficient and automated acquisition of the 3D spatial data with higher resolution. In this research, the automatic urban object recognition methodology was proposed by integrating ultra highresolution stereo images and LiDAR data. Moreover, a method to enable more reliable and detailed stereo matching method for CCD images was examined by using LiDAR data as an initial 3D data to determine the search range and to detect possibility of occlusions. Finally, intellectual DSMs, which were identified urban features with high resolution, were generated with high speed processing.

• Journal of the Korean Institute of Telematics and Electronics
• /
• v.25 no.12
• /
• pp.1559-1565
• /
• 1988

In computed tomography, the errors asociated with interpolation in the reconstruction process degrade the reconstructed image and may cause divergence unless a large number of rays is used. A new data acquisition scheme without interpolation is developed in this paper. Samples (projection data ) are taken in phase with samples of the Cartesian grid to eliminated errors associated with interpolation process.

• Journal of the Semiconductor & Display Technology
• /
• v.9 no.3
• /
• pp.47-51
• /
• 2010

This paper presents a wafer pre-alignment system which is improved using the image of the entire wafer area. In the previous method, image acquisition for wafer takes about 80% of total pre-alignment time. The proposed system uses only one image of entire wafer area via a high-resolution CMOS camera, and so image acquisition accounts for nearly 1% of total process time. The larger FOV(field of view) to use the image of the entire wafer area worsen camera lens distortion. A camera calibration using high order polynomials is used for accurate lens distortion correction. And template matching is used to find a correct notch's position. The performance of the proposed system was demonstrated by experiments of wafer center alignment and notch alignment.