• Electronics and Telecommunications Trends
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• v.35 no.5
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• pp.112-122
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• 2020

In 3D computer graphics, a depth map is an image that provides information related to the distance from the viewpoint to the subject's surface. Stereo sensors, depth cameras, and imaging systems using an active illumination system and a time-resolved detector can perform accurate depth measurements with their own light sources. The 3D image information obtained through the depth map is useful in 3D modeling, autonomous vehicle navigation, object recognition and remote gesture detection, resolution-enhanced medical images, aviation and defense technology, and robotics. In addition, the depth map information is important data used for extracting and restoring multi-view images, and extracting phase information required for digital hologram synthesis. This study is oriented toward a recent research trend in deep learning-based 3D data analysis methods and depth map information extraction technology using a convolutional neural network. Further, the study focuses on 3D image processing technology related to digital hologram and multi-view image extraction/reconstruction, which are becoming more popular as the computing power of hardware rapidly increases.

• Nuclear Engineering and Technology
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• v.46 no.1
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• pp.27-38
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• 2014

The Fukushima Dai-Ichi accident in 2011 has affected various aspects of the nuclear society worldwide. The accident revealed some problems in the conventional approaches used to ensure the safety of nuclear installations. To prevent such disastrous accidents in the future, we have to learn from them and improve the conventional approaches in a more systematic manner. In this paper, we will cover three issues. The first is to identify the key issues that affected the progress of the Fukushima Dai-Ichi accident greatly. We examine the accident from a defense-in-depth point of view to identify such issues. The second is to develop a more systematic approach to enhance the safety of nuclear installations. We reexamine nuclear safety from a risk point of view. We use the concepts of residual and unknown risks in classifying the risk space. All possible accident scenarios types are reviewed to clarify the characteristics of the identified issues. An approach is proposed to improve our conventional approaches used to ensure nuclear safety including the design of safety features and the safety assessments from a risk point of view. Finally, we address some issues to be improved in the conventional risk assessment and management framework and/or practices to enhance nuclear safety.

• Journal of the Society of Naval Architects of Korea
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• v.60 no.4
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• pp.256-265
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• 2023

This paper describes the results of the development of the submarine Free Running Model (FRM). First, the goal of development was set based on the test conditions and the test environment, and the system was obtained accordingly. The target submarine, Joubert BB2 submarine, was selected with a scale of 18.35 in accordance with the development goal. In order to conduct a submarine FRM test underwater, where communication is impossible, the FRM must operate at least semi-autonomously. For this purpose, an Extended Kalman Filter (EKF) based underwater integrated navigation system and control system using a sailplane and an X-shaped sternplane were designed respectively. In addition, a ballast system was designed to enable the model to float to the water surface in case of an emergency. To verify its propulsion, navigation, and control performance, the FRM tests were conducted in both indoor and outdoor basins. As a result, the relationship between propeller RPM and vehicle speed was derived, and it was confirmed that the navigation and control performance met the target value.

• Journal of the Korean Society of Propulsion Engineers
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• v.23 no.1
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• pp.108-115
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• 2019

The thermal response of elastomeric insulators used as protection against high-temperature and high-pressure combustion gases varies depending on their composition and thermal environment conditions. In this paper, the thermal response characteristics of elastomeric insulators in different mixing environments were compared. Tests to determine thermal protection performance were carried out using a thermal protection rubber evaluation motor(TPREM), combustion gas velocities of 20 m/s and 100 m/s were tested at a chamber pressure of 1,000 psig. The pressure time curve of the chamber, the temperature time curve of the internal materials, the residual thickness and the thermal destruction depth of the test specimens were obtained. The results showed that the thermal protection performance of elastomeric insulators in different mixing environments was similar.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.12 no.5
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• pp.2366-2395
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• 2018

Multi-view super-resolution (MVSR) refers to the process of reconstructing a high-resolution (HR) image from a set of low-resolution (LR) images captured from different viewpoints typically by different cameras. These multi-view images are usually obtained by a camera array. In our previous work [1], we super-resolved multi-view LR images via image fusion (IF) and blind deblurring (BD). In this paper, we present a new MVSR method that jointly realizes IF and BD based on an integrated energy function optimization. First, we reformulate the MVSR problem into a multi-channel blind deblurring (MCBD) problem which is easier to be solved than the former. Then the depth map of the desired HR image is calculated. Finally, we solve the MCBD problem, in which the optimization problems with respect to the desired HR image and with respect to the unknown blur are efficiently addressed by the alternating direction method of multipliers (ADMM). Experiments on the Multi-view Image Database of the University of Tsukuba and images captured by our own camera array system demonstrate the effectiveness of the proposed method.

• Proceedings of the Korean Nuclear Society Conference
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• 2004.10a
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• pp.401-402
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• 2004

• Proceedings of the Korean Nuclear Society Conference
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• 2004.10a
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• pp.347-348
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• 2004

• Proceedings of the Korean Nuclear Society Conference
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• 2004.05a
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• pp.155.1-155.1
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• 2004

• Proceedings of the Korean Nuclear Society Conference
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• 2005.05a
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• pp.837-838
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• 2005

• Journal of Korean Institute of Industrial Engineers
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• v.39 no.6
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• pp.486-497
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• 2013

In this paper, we first present an in-depth survey of the research on Verification, Validation and Accreditation (VV&A) applied in various areas. Then we introduce the characteristics of the military and defense Modeling and Simulation (M&S) and propose the direction of method for VV&A with the identified characteristics. The M&S has been widely used in many different applications in the military and defense area including training, analysis, and acquisition. Methods and processes of VV&A have been proposed by researchers and M&S practitioners to guarantee the correctness of the M&S. The idea of applying the formal credibility assessment in VV&A is originated from the Software Engineering Reliability Test and Systems Engineering Development Process. However, the current VV&A techniques and processes proposed in the research community have not utilized the military-and-defense specific characteristics. We identify the characteristics and issues that can be found in the military and defense M&S. Then propose the direction of techniques and methods for VV&A considering the characteristics and issues. Also, possible research direction on the development of VV&A is proposed.