• Journal of Broadcast Engineering
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• v.25 no.5
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• pp.672-684
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• 2020

Restoring a low resolution and motion blurred light field has become essential due to the growing works on parallax-based image processing. These tasks are known as light-field enhancement process. Unfortunately, only a few state-of-the-art methods are introduced to solve the multiple problems jointly. In this work, we design a framework that jointly solves light field spatial super-resolution and motion deblurring tasks. Particularly, we generate a straight-forward neural network that is trained under low-resolution and 6-degree-of-freedom (6-DOF) motion-blurred light field dataset. Furthermore, we propose the strategy of local region optimization on the adversarial network to boost the performance. We evaluate our method through both quantitative and qualitative measurements and exhibit superior performance compared to the state-of-the-art methods.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.28 no.8
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• pp.636-645
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• 2017

A scanning radar is exploited widely such as for ground surveillance, disaster rescue, and etc. However, the range resolution is limited by transmitted bandwidth and cross-range resolution is limited by beam width. In this paper, we propose a method for super-resolution radar imaging. If the distribution of reflectivity is sparse, the distribution is called sparse signal. That is, the problem could be formulated as compressive sensing problem. In this paper, 2D super-resolution radar image is generated via reweighted ${\ell}_1-Minimization$. In the simulation results, we compared the images obtained by the proposed method with those of the conventional Orthogonal Matching Pursuit(OMP) and Synthetic Aperture Radar(SAR).

• Journal of the Korea Institute of Information and Communication Engineering
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• v.26 no.3
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• pp.381-388
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• 2022

In instance segmentation, Mask-RCNN is mostly used as a base model. Increasing the performance of Mask-RCNN is meaningful because it affects the performance of the derived model. Mask-RCNN has a transform module for unifying size of input images. In this paper, to improve the Mask-RCNN, we apply deep-learning-based ASSR to the resizing part in the transform module and inject calculated scale information into the model using IM(Integration Module). The proposed IM improves instance segmentation performance by 2.5 AP higher than Mask-RCNN in the COCO dataset, and in the periment for optimizing the IM location, the best performance was shown when it was located in the 'Top' before FPN and backbone were combined. Therefore, the proposed method can improve the performance of models using Mask-RCNN as a base model.

• Journal of the Korea Society of Computer and Information
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• v.26 no.4
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• pp.47-53
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• 2021

In this paper, we propose a quadtree-based optimization technique that enables fast Super-resolution(SR) computation by efficiently classifying and dividing physics-based simulation data required to calculate SR. The proposed method reduces the time required for quadtree computation by downscaling the smoke simulation data used as input data. By binarizing the density of the smoke in this process, a quadtree is constructed while mitigating the problem of numerical loss of density in the downscaling process. The data used for training is the COCO 2017 Dataset, and the artificial neural network uses a VGG19-based network. In order to prevent data loss when passing through the convolutional layer, similar to the residual method, the output value of the previous layer is added and learned. In the case of smoke, the proposed method achieved a speed improvement of about 15 to 18 times compared to the previous approach.

• Journal of Advanced Navigation Technology
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• v.27 no.5
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• pp.495-501
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• 2023

P-3C/K aircraft for maritime patrols that Republic of Korea Navy is using, is equipped with a variety of sensors and communication devices. Collected data from the aircraft is managed as tactical information by flight operators and stored. When the flight mission is completed, this information is transferred to tactical support center on the ground and played back or used for follow-up work through a analysis tool. During a flight mission, there are tens of thousands of detection objects within an hour in KADIZ (Korea air defense identification zone). In contrast, in TSD (tactical situation display), which displays a map when using the analysis tool, all detected objects are expressed as symbols. The increase in display symbols has a significant impact on the TSD image updating and consequently interferes with the smooth operation of operators. In this paper, we propose applying multiple threads and multiple layers to improve the performance of existing TSD. And the performance improvement is proven through the execution results.

• Journal of Intelligence and Information Systems
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• v.29 no.4
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• pp.257-269
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• 2023

There is currently a burgeoning demand for image synthesis from photos and videos using deep learning models. Existing video synthesis models solely extract motion information from the provided video to generate animation effects on photos. However, these synthesis models encounter challenges in achieving accurate lip synchronization with the audio and maintaining the image quality of the synthesized output. To tackle these issues, this paper introduces a novel framework based on an image animation approach. Within this framework, upon receiving a photo, a video, and audio input, it produces an output that not only retains the unique characteristics of the individuals in the photo but also synchronizes their movements with the provided video, achieving lip synchronization with the audio. Furthermore, a super-resolution model is employed to enhance the quality and resolution of the synthesized output.

• Bulletin of the Society of Naval Architects of Korea
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• v.27 no.2
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• pp.31-39
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• 1990

Deck wetness phonomena has long been considered as one of the factors that degrade the performance of a ship in waves. In rough weather, the frequent shipping of water may give rise to the capsizing of the ship. Therefore an appropriate above water bow design is an improtant assert to a ship of which successful performance in rough weather is a prerequisite such as a warship. In this paper the experimental technique for estimation of deck wetness frequency is presented. The results of the model tests are compared with those of calculation using Ochi's formula. Finally the applicability of Ochi's formula is discussed.

• Journal of Advanced Marine Engineering and Technology
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• v.41 no.1
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• pp.105-110
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• 2017

This paper introduces a heave compensation system for offshore crane when it subjected to unexpected disturbances such as ocean waves, tidal currents or winds and their external force. The dynamic model consists of a crane which is considered to behave in the same manner as a rigid body, a hydraulic driven winch, an elastic rope and a payload. To keep the payload from moving upwards and downwards, PD(Proportional-Derivative) control was applied by using linearization. In order to achieve a better performance, the sliding mode control and the nonlinear generalized predictive control algorithm was applied according to the time-delay. As a result, the oscillating amplitude of the payload was reduced by the control algorithm. Considering the time-delay involved in the system to be one second, nonlinear generalized predictive controller with a robust controller was a suitable control algorithm for this heave compensation system because it made the position of te payload reach the desired position with the minimum error. This paper presented a control algorithm using the robust control and its simulation results.

• Journal of the Korean Institute of Navigation
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• v.25 no.1
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• pp.77-91
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• 2001

According to the many ancient literatures, it is said to be that Merchant Prince, Chang Pogo in unification Silla had traded with not only China, Japan but also Arab-Islam Countries, but unfortunately there is no definite records about this. Therefore in this study the writer would like to presume the sea routes of Merchant Prince, Chang Pogo in a unification Silla. For the purpose of this study the writer would like to study the reference books and materials regarding to the sea routes of prehistoric age and ancient three countries of Kingdoms and unification Silla. Especially the writer consider “The Work of Routes and Kingdoms” of Ibn Khurdarhbih regarding to the ancient sea routes of Korea, China, Arab-Islam Countries, and also the writer consider the ancient sea routes of Tang Dynasty in China and Ryukyu Kingdom in Japan. About this methodology of this study, the writer believe that the sea routes of today is the results of ancient sea routes, and this ancient sea routes could not be changed forever except special circumstance. According in this study the writer would like to persume the sea routes of Merchant Prince, Chang Pogo using like this methodologies. This presumption of the writer is originated on the basis of The Work of Routes and Kingdoms written by ancient Arabian Geographer, Ibn Khurdadhbih in the early years of 9th century. The Work of Routes and Kingdoms is geography, and the principal contents of this geography are the activities of Arab-Islam merchants and Chinese Merchants between Arab-Islam countries and China from 9th century to 11th century by ancient sea routes. But surprisingly in this geography, Silla was marked, and another ancient Arabian geogrpher, Al-Biruni marked Silla on his map, Qanun Al-mas'udi in the 9th century, and also another ancient Arabian geographer, Al-Idrisi marked Silla on his map in the 11th century. Especially Al-Biruni expressed the longitude and latitude of Silla on his map, he expressed Silla as following. “at the extreme end of China toward the East and few people travelled to it by sea”. Therefore the writer would like to presume that Arab-Islam merchants had traded with unification Silla in the 9th century, and also Merchant Prince, Chang Pogo had traded with not only China, Japan but also Arab-Islam Countries using above ancient sea routes in the 9th century.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.33 no.10
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• pp.98-103
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• 2005

The Flight Model of MAC (Medium-sized Aperture Camera), a 2.5m GSD class earth observation camera has been aligned and assembled. Topics discussed in this paper include the ground MTF performance of the MAC system, and the alignment of the focal plane assembly. MTF was measured by a knife-edge scanning technique, and a 450 mm diameter Cassegrain collimator with diffraction-limited performance was made and used for the MTF measurements. System MTF was used as the figure-of-merit to find the best focus of the focal plane assembly.