• The Journal of Korea Robotics Society
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• v.15 no.3
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• pp.293-300
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• 2020

The purpose of our sensor system is to transparentize the large hydraulic manipulators of a six-ton dual arm excavator from the operator camera view. Almost 40% of the camera view is blocked by the manipulators. In other words, the operator loses 40% of visual information which might be useful for many manipulator control scenarios such as clearing debris on a disaster site. The proposed method is based on a 3D reconstruction technology. By overlaying the camera image from front top of the cabin with the point cloud data from RGB-D (red, green, blue and depth) cameras placed at the outer side of each manipulator, the manipulator-free camera image can be obtained. Two additional algorithms are proposed to further enhance the productivity of dual arm excavators. First, a color correction algorithm is proposed to cope with the different color distribution of the RGB and RGB-D sensors used on the system. Also, the edge overlay algorithm is proposed. Although the manipulators often limit the operator's view, the visual feedback of the manipulator's configurations or states may be useful to the operator. Thus, the overlay algorithm is proposed to show the edge of the manipulators on the camera image. The experimental results show that the proposed transparentization algorithm helps the operator get information about the environment and objects around the excavator.

• Journal of the Korean Society for Precision Engineering
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• v.20 no.12
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• pp.105-114
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• 2003

In this study, a dicing machine with vision system was built and an algorithm for automatic alignment was developed for dual camera system. The system had a macro and a micro inspection tool. The algorithm was formulated from geometric relations. When a wafer was put on the cutting stage within certain range, it was inspected by vision system and compared with a standard pattern. The difference between the patterns was analyzed and evaluated. Then, the stage was moved by x, y, $\theta$ axes to compensate these differences. The amount of compensation was calculated from the result of the vision inspection through the automatic alignment algorithm. The stage was moved to the compensated position and was inspected by vision for checking its result again. Accuracy and validity of the algorithm was discussed from these data.

• The Korean Journal of Nuclear Medicine Technology
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• v.13 no.1
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• pp.57-62
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• 2009

Purpose: Brain SPECT study is more sensitive to motion than other studies. Especially, when applying 1-day subtraction method for Diamox SPECT, it needs shorter study time in order to prevent reexamination. We were required to have new study condition and analysing method on dual detector system because triple head camera in Seoul National University Hospital is to be disposed. So we have tried to increase image quality and make the dual and triple head to have equivalent study time by using a new analysing program. Materials and Methods: Using IEC phantom, we estimated contrast, SNR and FWHM. In Hoffman 3D brain phantom which is similar with real brain, we were on the supposition that 5% of injected doses were distributed in brain tissue. To compare with existing FBP method, we used fan-beam collimator. And we applied 15 sec, 25 sec/frame for each SEPCT studies using LEHR and LEUHR. We used OSEM2D and Onco-flash3D reconstruction method and compared reconstruction methods between applied Gaussian post-filtering 5mm and not applied as well. Attenuation correction was applied by manual method. And we did Brain SPECT to patient injected 15 mCi of $^{99m}Tc$-HMPAO according to results of Phantom study. Lastly, technologist, MD, PhD estimated the results. Results: The study shows that reconstruction method by Flash3D is better than exiting FBP and OSEM2D when studied using IEC phantom. Flowing by estimation, when using Flash3D, both of 15 sec and 25 sec are needed postfiltering 5 mm. And 8 times are proper for subset 8 iteration in Flash3D. OSEM2D needs post-filtering. And it is proper that subset 4, iteration 8 times for 15sec and subset 8, iteration 12 times for 25sec. The study regarding to injected doses for a patient and study time, combination of input parameter-15 sec/frame, LEHR collimator, analysing program-Flash3D, subset 8, iteration 8times and Gaussian post-filtering 5mm is the most appropriate. On the other hands, it was not appropriate to apply LEUHR collimator to 1-day subtraction method of Diamox study because of lower sensitivity. Conclusions: We could prove that there was also an advantage of short study time effectiveness in Dual camera same as Triple gamma camera and get great result of alternation from existing fan-beam collimator to parallel collimator. In addition, resolution and contrast of new method was better than FBP method. And it could improve sensitivity and accuracy of image because lesser subjectivity was input than Metz filter of FBP. We expect better image quality and shorter study time of Brain SPECT on Dual detector system.

• Journal of Korea Multimedia Society
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• v.16 no.11
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• pp.1272-1280
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• 2013

In this paper, we propose an audio surveillance system which can detect and localize dangerous sounds in real-time. The location information about dangerous sounds can render a PTZ camera to be directed so as to catch a snapshot image about the dangerous sound source area and send it to clients instantly. The proposed audio surveillance system firstly detects foreground sounds based on adaptive Gaussian mixture background sound model, and classifies it into one of pre-trained classes of foreground dangerous sounds. For detected dangerous sounds, a sound source localization algorithm based on Dual delay-line algorithm is applied to localize the sound sources. Finally, the proposed system renders a PTZ camera to be oriented towards the dangerous sound source region, and take a snapshot against over the sound source region. Experiment results show that the proposed system can detect foreground dangerous sounds stably and classifies the detected foreground dangerous sounds into correct classes with a precision of 79% while the sound source localization can estimate orientation of the sound source with acceptably small error.

• The Journal of Korea Robotics Society
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• v.9 no.3
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• pp.140-146
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• 2014

This paper introduces a dual-arm robot painter system which is capable of sketching a camera-captured image with short line segments. To express various curved edges in the image by combining line segments, we first apply edge detection algorithm to the entire image, split the edged image into small boxed pieces, and then apply Hough Transformation to each piece so that the edges inside the piece can be approximated with short line segments. To draw the picture within a reasonable time, we designed a simple dual-arm robot system and controlled both arms concurrently according to linear interpolation algorithm. From the experiments, we could verify that simple linear motions can describe various images effectively with a unique brush style.

• Journal of the Optical Society of Korea
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• v.16 no.1
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• pp.63-69
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• 2012

This paper presents a method to derive the theoretical requirements for the development of a 400 mm optical window that transmits dual-band wavelengths and had a stable structure. We also present design and fabrication results. Among the required specifications, the surface figure error was defined by the transmitted wavefront deformation (TWD), ${\lambda}$/15 rms at 632.8 nm. This value was derived by estimating the predicted performances with respect to five independent items that could cause system performance degradation and then calculating the required wavefront error (WFE) to satisfy the performance goals. We measured the image resolution at each performance level to trace and verify the requirements. The article also describes a design optimization process that could minimize the weight and volume of the optical window attached to the payload securing the FOV of the camera. In addition, we accurately measured the deformation that occurred in the series of fabrication steps including processing, coating, assembly, bonding and bolting, and investigated the effects by comparing them to the results of a simulation performed in advance to derive the predicted performance.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.9 no.9
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• pp.3721-3737
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• 2015

3D reconstruction based on binocular data is significant to machine vision. In our method, we propose a new and high efficiency 3D reconstruction approach by using a consumer camera aiming to: 1) address the configuration problem of dual camera in the binocular reconstruction system; 2) address stereo matching can hardly be done well problem in both time computing and precision. The kernel feature is firstly proposed in calibration stage to rectify the epipolar. Then, we segment the objects in the camera into background and foreground, for which system obtains the disparity by different method: local window matching and kernel feature-based matching. Extensive experiments demonstrate our proposed algorithm represents accurate 3D model.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2002.05a
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• pp.357-360
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• 2002

Nowadays, the improvement and development of Multi-media, information and communication technology are rapidly processed. And many products, for example, digital camera, digital camcorder, and PDA, are used for them. They need large data storage capacity and small size, light storage system. Due to that, many studies and researches in data storage system have been carried out. Especially, micro drive system was presented by IBM.(1) However, its system is expensive and uneasy to be portable. In ODD technologies, 1 inch drive system is not yet or in processing status.(2) If to be possible and to be come up, it is cheap than HDD system and easy to transfer information. In this paper, a miniaturized actuator(about linch) is designed and tested for ODD system. Specially, it is adapted for NFR(Near-field Recoding) system using SIL(Solid Immersion Lens). It is the dual-servo actuator which consists of a coarse actuator and fine actuator. Its actuating force generation method is VCM(Voice Ceil Motor). The fine actuator has 4-wire suspensions and bobbin wrapped by coil and includes focusing motion as well as tracking motion. The coarse actuator has an actuating coil and V-grooved guide mechanism. Also, the characteristics of the designed actuator is estimated by sine-swept mode and LDV(Laser Doppler Vibro-meter).

• Proceedings of the KSRS Conference
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• 2007.10a
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• pp.203-206
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• 2007

The Space-borne electro-optical camera system has panchromatic redundant image channel as well as primary channel in order to increase reliability of satellite system. In most case redundant channel never been used during the whole mission period. Staggered array configuration using redundant image channel and new operation mode proposed which operates primary and redundant channel simultaneously. Without new hardware design, fast electronics and system complexity, we can get 1.414 times more fine GSD image of original system or we can get 1.414 times more SNR or High dynamic range imaging mode. In this paper we deal with several image quality improvement methods using dual panchromatic channel.

• Journal of Radiation Protection and Research
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• v.37 no.1
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• pp.16-24
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• 2012

In the present study, a gamma-ray detector and associated signal processing circuit was developed for a side-absorber of a dual-mode Compton camera. The gamma-ray detector was made by optically coupling a CsI(Tl) scintillation crystal to a silicon photodiode. The developed signal processing circuit consists of two parts, i.e., the slow part for energy measurement and the fast part for timing measurement. In the fast part, there are three components: (1) fast shaper, (2) leading-edge discriminator, and (3) TTL-to-NIM logic converter. AC coupling configuration between the detector and front-end electronics (FEE) was used. Because the noise properties of FEE can significantly affect the overall performance of the detection system, some design criteria were presented. The performance of the developed system was evaluated in terms of energy and timing resolutions. The evaluated energy resolution was 12.0% and 15.6% FWHM for 662 and 511 keV peaks, respectively. The evaluated timing resolution was 59.0 ns. In the conclusion, the methods to improve the performance were discussed because the developed gamma-ray detection system showed the performance that could be applicable but not satisfactory in Compton camera application.