• Journal of Korea Multimedia Society
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• v.25 no.1
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• pp.1-9
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• 2022

Ship detection in synthetic aperture radar (SAR) images is an important application in marine monitoring for the military and civilian domains. Over the past decade, object detection has achieved significant progress with the development of convolutional neural networks (CNNs) and lot of labeled databases. However, due to difficulty in collecting and labeling SAR images, it is still a challenging task to solve SAR ship detection CNNs. To overcome the problem, some methods have employed conventional data augmentation techniques such as flipping, cropping, and affine transformation, but it is insufficient to achieve robust performance to handle a wide variety of types of ships. In this paper, we present a novel and effective approach for deep SAR ship detection, that exploits label-rich Electro-Optical (EO) images. The proposed method consists of two components: a data augmentation network and a ship detection network. First, we train the data augmentation network based on conditional generative adversarial network (cGAN), which aims to generate additional SAR images from EO images. Since it is trained using unpaired EO and SAR images, we impose the cycle-consistency loss to preserve the structural information while translating the characteristics of the images. After training the data augmentation network, we leverage the augmented dataset constituted with real and translated SAR images to train the ship detection network. The experimental results include qualitative evaluation of the translated SAR images and the comparison of detection performance of the networks, trained with non-augmented and augmented dataset, which demonstrates the effectiveness of the proposed framework.

• The Journal of Korean Physical Therapy
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• v.28 no.5
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• pp.297-302
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• 2016

Purpose: This study was conducted to evaluate the effects of bridge exercise on the structural characteristics of trunk muscles in patients with lumbar pain by applying the exercise on either a stable or an unstable surface. Methods: Thirty subjects participated in the experiment and were randomly divided into an unstable bridge exercise group (UBEG) and a stable bridge exercise group (SBEG). The exercise program for each group was conducted three times a week over a six-week period. The structural characteristics of trunk muscles were measured by obtaining images using an ultrasound imaging device. Results: The thicknesses of the external oblique (EO), internal oblique (IO), and transverse abdominis (TrA) and the fiber angle of the erector spinae (ES) in the UBEG and the SBEG showed statistically significant increases in all items measured after the experiment. A comparison of groups conducted after the experiment to determine the effects of the exercise on each group showed no significant differences between groups for any of the measured items. Conclusion: A comprehensive review of the study results showed statistically significant increases in the thicknesses of the EO, IO, and TrA and the fiber angle of ES in both the UBEG and the SBEG. While the comparison of the groups with respect to the effects of the exercise revealed no significant differences, there were relatively larger effects in the UBEG than in the SBEG.

• Membrane Journal
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• v.17 no.2
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• pp.140-145
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• 2007

In this study, 3-(trihydroxysilyl)-1-propanesulfonic acid (THS-PSA) was added to poly(vinyl alcohol) (PVA) membranes crosslinked with poly(styrene sulfonic acid-co-maleic acid) (PSSA_MA) to improve the separation characteristics toward water vapors in the air. The prepared membranes varying both PSSA_MA and THS-PSA amounts were also synthesized at different cross linking temperatures. Then, in order to investigate the separation characteristics of the resulting membranes, the dynamic vapor sorption (DVS) and vapor permeation experiments were carried out. The increase of cross-linking temperature showed longer time to reach the equilibrium sorption state from the dynamic vapor sorption experiments. PVA/PSSA_MA (3%)/THA-PSA(7%) prepared at $120^{\circ}C$ gave the highest permeability of 480 barrer at $35^{\circ}C$.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2007.11a
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• pp.399-399
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• 2007

Recently, it is widely studied to liquid crystal (LC) alignment using ion-beam exposure. Because conventional rubbing method has some problems such as defects from dust and electrostatic charges during rubbing process. Therefore rubbing-free techniques like ion-beam method are strongly required. We studied LC alignment by controlling ion-beam energy density and electro-optical (EO) characteristics of twisted nematic LC on the polyimide surface. In this experiment, a good uniform alignment of the nematic liquid crystal (NLC) with the ion-beam exposure on the polyimide (PI) surface was observed. In addition, it can be achieved the good EO properties of the ion-beam-aligned twisted nematic liquid crystal display (TN-LCD) on PI surface.

• The Journal of Korean Physical Therapy
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• v.26 no.6
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• pp.453-458
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• 2014

Purpose: The purpose of this study was to compare the activities of the abdominal and neck flexor muscles of children with and without cerebral palsy (CP) while lifting the head in a supine position. Methods: The subjects were eight children with CP and eight children without the disease. The activities of the external abdominal oblique (EO), internal abdominal oblique (IO), rectus abdominis (RA), sternocleidomastoid (SCM), and RA/SCM muscles were collected by surface electromyography (EMG) when the children lifted their heads. A Mann-Whitney U test was used to compare the activity of each muscle during the head-lifting exercise. Statistical significance was accepted at p<0.05. Results: The activities of the EO, IO, and RA, and RA/SCM muscles differed significantly between the children with and without CP, but there was no significant between-group difference in the activity of the SCM muscle. Conclusion: These findings suggest that the abdominal muscles are not employed as much in the activities of children with CP compared to those without the disease. Additionally, those with CP were more dependent on the neck flexor muscle during the head-lifting exercise in a supine position.

• Current Optics and Photonics
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• v.6 no.3
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• pp.323-331
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• 2022

Electro-optic modulator (EOM) takes a vital role in connecting the electric and optical fields. Here, we present a heterogeneously integrated EOM based on the lithium niobate-on-insulator (LNOI) platform. The key modulation waveguide structure is a field-enhanced slot waveguide formed by embedding silicon nanowires in a thin-film lithium niobate (LN), which is different from the previously reported LN ridge or etchless LN waveguides. Based on such slot structure, optical mode field area is reduced and enhanced electric field in the slot region can interact well with LN material with high Electro-optic (EO) coefficient. Therefore, the improvements in both aspects have positive effects on enhancing the modulation performance. From results, the corresponding EOM by adding such modulation waveguide structure achieves better performance, where the key half-wave-voltage-length product (V_𝜋L) and 3 dB EO bandwidth are 1.78 V·cm and 40 GHz under the electrode gap width of only 6 ㎛, respectively. Moreover, Lower V_𝜋L can also be achieved. With these characteristics, such field-enhanced waveguide structure could further promote the development of LNOI-based EOM.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2001.07a
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• pp.369-372
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• 2001

We studied the electro-optical (EO) performance in the vertical-alignment (VA) - l/4$\pi$ cell photoaligned with polarized UV exposure on a homeotropic photopolymer surfaces. Excellent voltage-transmittance curve in the VA - l/4$\pi$ cell photoaligned with polarized UV exposure for 3 min on the photopolymer containing cholesterol group of 8% can be achieved. The V-T characteristics in the VA-l/4$\pi$ cell photoaligned on the photopolymer surface can be improved by increasing cholesteryl group. For response time measurement, the transmittance characteristics of the VA-l/4$\pi$ cell photoaligned on the photopolymer surface was better than that of the VA-l/4$\pi$ cell rubbingaligned on a polyimide(Pl) surface.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.14 no.8
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• pp.670-674
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• 2001

The electro-optical (EO) performance in the vertical-alignment (VA) - 1/4$\pi$ cell photoaligned with polarized UV exposure on a homeotropic photopolymer surfaces was investigated. Excellent voltage-transmittance curve in the VA - 1/4$\pi$ cell photoaligned with polarized UV exposure for 3 min on the photopolymer containing cholesteryl group of 8% can be achieved. The V-T characteristics in the VA-1/4$\pi$ cell photoaligned on the photopolymer surface can be improved by increasing cholesteryl group. For response time measurement, the transmittance characteristics of the VA-1/4$\pi$ cell photopolymer surface was better than that of the VA-1/4$\pi$ cell rubbingaligned on a polyimide(PI) surface.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2011.10a
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• pp.791-792
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• 2011

• Journal of the Korea Institute of Military Science and Technology
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• v.13 no.1
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• pp.67-76
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• 2010

RAM(Reliability, Availability, Maintainability) characteristics of weapon system is a part of Required Operational Capability, must be reasonable and achievable. In this study, we studied the criteria, important factors to establish RAM requirement and reviewed the current process. Then we propose the new process and method to establish the reasonable and achievable RAM requirement by BCS(Baseline Comparison System) model.