• The Journal of Korean Institute of Communications and Information Sciences
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• v.30 no.3C
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• pp.125-132
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• 2005

This paper describes a computer vision system based on active IR illumination for real-time gaze discrimination system. Unlike most of the existing gaze discrimination techniques, which often require assuming a static head to work well and require a cumbersome calibration process for each person, our gaze discrimination system can perform robust and accurate gaze estimation without calibration and under rather significant head movement. This is made possible by a new gaze calibration procedure that identifies the mapping from pupil parameters to screen coordinates using generalized regression neural networks (GRNNs). With GRNNs, the mapping does not have to be an analytical function and head movement is explicitly accounted for by the gaze mapping function. Futhermore, the mapping function can generalize to other individuals not used in the training. To further improve the gaze estimation accuracy, we employ a reclassification scheme that deals with the classes that tend to be misclassified. This leads to a 10% improvement in classification error. The angular gaze accuracy is about 5°horizontally and 8°vertically. The effectiveness of our gaze tracker is demonstrated by experiments that involve gaze-contingent interactive graphic display.

• The Journal of Korea Institute of Information, Electronics, and Communication Technology
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• v.3 no.1
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• pp.38-46
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• 2010

This paper describes a computer vision system based on active IR illumination for real-time gaze discrimination system. Unlike most of the existing gaze discrimination techniques, which often require assuming a static head to work well and require a cumbersome calibration process for each person, our gaze discrimination system can perform robust and accurate gaze estimation without calibration and under rather significant head movement. This is made possible by a new gaze calibration procedure that identifies the mapping from pupil parameters to screen coordinates using generalized regression neural networks (GRNNs). With GRNNs, the mapping does not have to be an analytical function and head movement is explicitly accounted for by the gaze mapping function. Furthermore, the mapping function can generalize to other individuals not used in the training. To further improve the gaze estimation accuracy, we employ a reclassification scheme that deals with the classes that tend to be misclassified. This leads to a 10% improvement in classification error. The angular gaze accuracy is about $5^{\circ}$horizontally and $8^{\circ}$vertically. The effectiveness of our gaze tracker is demonstrated by experiments that involve gaze-contingent interactive graphic display.

• Journal of Broadcast Engineering
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• v.7 no.3
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• pp.248-261
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• 2002

In this paper, we proposed a new 3-dimensional(3-D) object-tracking algorithm that can control a stereo camera using a variable window mask supported by which uses ,B-D information and an optical BPEJTC. Hence, three-dimensional information characteristics of a stereo vision system, distance information from the stereo camera to the tracking object. can be easily acquired through the elements of a stereo vision system. and with this information, we can extract an area of the tracking object by varying window masks. This extractive area of the tracking object is used as the next updated reference image. furthermore, by carrying out an optical BPEJTC between a reference image and a stereo input image the coordinates of the tracking objects location can be acquired, and with this value a 3-D object tracking can be accomplished through manipulation of the convergence angie and a pan/tilt of a stereo camera. From the experimental results, the proposed algorithm was found to be able to the execute 3-D object tracking by extracting the area of the target object from an input image that is independent of the background noise in the stereo input image. Moreover a possible implementation of a 3-D tele-working or an adaptive 3-D object tracker, using the proposed algorithm is suggested.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.45 no.9
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• pp.734-745
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• 2017

The navigation system of lunar lander are composed of various navigation sensors which have a complementary characteristics such as inertial measurement unit, star tracker, altimeter, velocimeter, and camera for terrain relative navigation to achieve the precision and autonomous navigation capability. The required performance of sensors has to be determined according to the landing scenario and mission requirement. In this paper, the specifications of navigation sensors are investigated through covariance analysis. The reference error model with 77 state vector and measurement model are derived for covariance analysis. The mission requirement is categorized as precision exploration with 90m($3{\sigma}$ ) landing accuracy and area exploration with 6km($3{\sigma}$ ), and the landing scenario is divided into PDI(Powered descent initiation) and DOI(Deorbit initiation) scenario according to the beginning of autonomous navigation. The required specifications of the navigation sensors are derived by analyzing the performance according to the sensor combination and landing scenario.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.62 no.2
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• pp.257-263
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• 2013

In case of image observation equipments, CCTV for short distance visual field is usually installed and operated mostly as the means of crime-prevention. However, the extensive demand for monitoring problems in case of the increase in intelligent crimes and disasters has led to the necessity of the development of long-distance observation equipments embedded with Night View functions. In case of the Night View equipments, the relevant market is set up to be focused mostly on Thermal Observation Device(hereinafter, TOD), but some shortcomings such as the limitation of image visibility and excessive maintenance cost, etc. have actually caused the necessity of new long distance Night View equipment. Moreover there might follow lots of difficulties in long-distance visualization in the event that irregular reflection is generated by minute particles in the atmosphere such as fog, smog, and dust, etc. These factors are motivate the work presented in this study. Our study is aimed at the realization of Pulsed Laser Illuminator and newly proposed Range-Gated image acquisition technology. And also the implementation of Tracker for continuous trace of the objects of interest from the obtained sequence images.

• Journal of the Korea Society for Simulation
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• v.27 no.1
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• pp.111-117
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• 2018

It is indispensable for a missile to track a target under the flight condition since the tracking capability affects the system performance considerably. The best way to verify the tracker's performance is flight test while it costs too much. Consequently, captive flight test or CFT has an important role in the development of a missile system. CFT, however, cannot simulate missile dynamics and is an offline and open-loop test. In this paper, we propose a new integrated-flight simulation(IFS) method using CFT imagery to overcome the limitation of synthetic image-based IFS method. This method increases the utilization of CFT's outputs and compensates the reality of imagery which lacks in the synthetic image-based IFS. Using this method make it possible to verify the system capability in various simulation modes.

• The Journal of Korea Institute of Information, Electronics, and Communication Technology
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• v.16 no.5
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• pp.247-255
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• 2023

In order to create a virtual reality space in the metaverse, accurate tracking sensors and implementation are required. Most government agencies and corporations performs tracking to use their own tracking sensors and a base stations, such as VIVE. The VIVE method may have tracking problems due to spatial constraints and obstacles or nearby structures, and it is also that the number of people that can be accommodated within the space is also limited. In this paper, we designed and implemented metaverse using an IR sensor tracking system to freely track the spatial virtual reality metaverse, and we experimented contents in metaverse by placing IR sensors additionally on the floor and ceiling if needed in order to flexibly configure the metaverse space. As a result of the experiment, the tracking stability of the IR-tracking system was approximately 12% higher than the VIVE method. Additionally, adding more tracking sensors on the floor increases tracking stability and allows for a stable representation of virtual space.

• Journal of the Institute of Convergence Signal Processing
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• v.12 no.3
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• pp.222-227
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• 2011

2-axis tracking solar PV system applying a fixed-type unit than in the same area as the panel's power output to more than 140% can be obtained that have been identified. However, this approach compared with fixed or 1-axis control system and control the complexity of trekking equipment power the cursor comes to a relatively small output PV unit is called. In this paper, a small PV power units as a way to improve the economics of the small output of multiple PV units in the central control unit in enclosed places an intermittent manner by a remote control for each unit of the trek at the same time to simplify the control mechanism to reduce power that will be introduced. also the construction of large-scale PV development plans in difficult environments can be utilized in a manner appropriate to introduce.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.18 no.2
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• pp.672-680
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• 2017

A solar photovoltaic system is composed of a module mounting structure, supporting trunk, and a control unit that supplies generated electrical power to an external power grid or a load. The efficiency of the system depends on the incident solar light, so the mounting structure is installed to face the sun. However, because the sun always moves, systems that track the sun have better efficiency than fixed systems. The structure experiences wind pressure, snow load, seismic load, and structure weight. The wind pressure has the most serious effect on the structure. The pressure was obtained using finite element method for various gaps between modules and angles between the panel and the ground. The wind pressure is lowest when the gap is zero, and it increases with the inclination angle. Based on the results, a mounting structure module was designed.

• Journal of Energy Engineering
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• v.26 no.1
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• pp.34-44
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• 2017

This paper deals with the effectiveness of a fiber optic solar lighting system that uses a Fresnel lens mounted on a two-axis solar tracker. A series of comparative analyses were made concerning its performance as compared to fluorescent lighting by using a simulation model based on ECOTECT and RADIANCE as well as referring to actual data. ECOTECT was used to model the test room (space) while RADIANCE was used for its indoor lighting conditions (environment). It was found that the average indoor light levels of fluorescent lighting fully satisfy the KS standard (KS A 3011, general office, class [G]: 300-400-600lux) whereas those of the solar lighting with light diffusers depends on the occlusion factor of roller shades installed on the south window.