• Title/Summary/Keyword: Defense Science Technology

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Performance Enhancement of Virtual War Field Simulator for Future Autonomous Unmanned System (미래 자율무인체계를 위한 가상 전장 환경 시뮬레이터 성능 개선)

  • Lee, Jun Pyo;Kim, Sang Hee;Park, Jin-Yang
    • Journal of the Korea Society of Computer and Information
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    • v.18 no.10
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    • pp.109-119
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    • 2013
  • An unmanned ground vehicle(UGV) today plays a significant role in both civilian and military areas. Predominantly these systems are used to replace humans in hazardous situations. To take unmanned ground vehicles systems to the next level and increase their capabilities and the range of missions they are able to perform in the combat field, new technologies are needed in the area of command and control. For this reason, we present war field simulator based on information fusion technology to efficiently control UGV. In this paper, we present the war field simulator which is made of critical components, that is, simulation controller, virtual image viewer, and remote control device to efficiently control UGV in the future combat fields. In our information fusion technology, improved methods of target detection, recognition, and location are proposed. In addition, time reduction method of target detection is also proposed. In the consequence of the operation test, we expect that our war field simulator based on information fusion technology plays an important role in the future military operation significantly.

Improvement of Mid-Wave Infrared Image Visibility Using Edge Information of KOMPSAT-3A Panchromatic Image (KOMPSAT-3A 전정색 영상의 윤곽 정보를 이용한 중적외선 영상 시인성 개선)

  • Jinmin Lee;Taeheon Kim;Hanul Kim;Hongtak Lee;Youkyung Han
    • Korean Journal of Remote Sensing
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    • v.39 no.6_1
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    • pp.1283-1297
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    • 2023
  • Mid-wave infrared (MWIR) imagery, due to its ability to capture the temperature of land cover and objects, serves as a crucial data source in various fields including environmental monitoring and defense. The KOMPSAT-3A satellite acquires MWIR imagery with high spatial resolution compared to other satellites. However, the limited spatial resolution of MWIR imagery, in comparison to electro-optical (EO) imagery, constrains the optimal utilization of the KOMPSAT-3A data. This study aims to create a highly visible MWIR fusion image by leveraging the edge information from the KOMPSAT-3A panchromatic (PAN) image. Preprocessing is implemented to mitigate the relative geometric errors between the PAN and MWIR images. Subsequently, we employ a pre-trained pixel difference network (PiDiNet), a deep learning-based edge information extraction technique, to extract the boundaries of objects from the preprocessed PAN images. The MWIR fusion imagery is then generated by emphasizing the brightness value corresponding to the edge information of the PAN image. To evaluate the proposed method, the MWIR fusion images were generated in three different sites. As a result, the boundaries of terrain and objects in the MWIR fusion images were emphasized to provide detailed thermal information of the interest area. Especially, the MWIR fusion image provided the thermal information of objects such as airplanes and ships which are hard to detect in the original MWIR images. This study demonstrated that the proposed method could generate a single image that combines visible details from an EO image and thermal information from an MWIR image, which contributes to increasing the usage of MWIR imagery.

Protective Effects of Green Tea Seed Extract against UVB-irradiated Human Skin Fibroblasts (인체 피부 섬유아세포에서 자외선 조사에 대한 녹차나무 씨 추출물의 보호효과)

  • Kim, Ok Kyung;Nam, Da-Eun;Lee, Min-Jae;Kang, Namgil;Lim, Jae-Youn;Lee, Jeongmin
    • Journal of the Korean Society of Food Science and Nutrition
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    • v.43 no.1
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    • pp.1-8
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    • 2014
  • In this study, we investigated the protective effects of green tea seed extract (GSE) against UVB-induced skin damage in human skin fibroblasts. GSE was first analyzed for antioxidant activity using 1,1-diphenyl-2picrylhydrazyl (DPPH) and 2,2'-azino-bis(3-ethylbenzthiazoline-6-sulphonic acid) (ABTS) radical scavenging assays. Treatment of UV-irradiated fibroblast with GSE at 10~50 ${\mu}g/mL$ significantly increased DPPH and ABTS radical scavenging activities in a dose-dependent manner. GSE treatment inhibited matrix metalloproteinase (MMP-1, MMP-3, and MMP-9) expression and MMP-1 secretion caused by UVB irradiation. Moreover, treatment with GSE significantly increased type-1 collagen expression and production. We next examined levels of antioxidative enzymes (SOD, catalase, and GPx). Reduced antioxidative enzyme activities caused by UVB irradiation were recovered by treatment with GSE at 30 ${\mu}g/mL$ and 50 ${\mu}g/mL$. In conclusion, these results show that GSE has protective effects against UVB-induced skin damage in human skin fibroblasts by regulating antioxidative defense systems and MMP expression.

Proteome Characterization of Sorghum (Sorghum bicolor L.) at Vegetative Stage under Waterlogging Stress (토양 과습 조건하에서 수수 잎의 단백질 양상)

  • Yun, Min Heon;Jeong, Hae-Ryong;Yoo, Jang-Hwan;Roy, Swapan Kumar;Kwon, Soo-Jeong;Kim, Joo-Ho;Chun, Hyen Chung;Jung, Ki Yuol;Cho, Seong-Woo;Woo, Sun-Hee
    • Korean Journal of Plant Resources
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    • v.31 no.2
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    • pp.124-135
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    • 2018
  • The study was performed to explore the molecular changes in the vegetative stage (3-and 5-leaf) of sorghum under waterlogging stress. A total of 74 differentially expressed protein spots were analyzed using LTQ-FT-ICR MS. Among them, 12 proteins were up-regulated and 3 proteins were down-regulated. Mass spectrometry (MS) results showed that about 50% of the proteins involved in various metabolic processes. The level of protein expression of malate dehydrogenase and glyceraldehyde-3-phosphate dehydrogenase related to carbohydrate metabolic process increased in both 3 and 5-leaf stage under waterlogging stress. These proteins are known to function as antistress agents against waterlogging stress. The expression of oxygen-evolving enhancer protein 1 protein related to photosynthesis was slightly increased in the treated group than in the control group, however the expression level was increased in the 5-leaf stage compared to the 3-leaf stage. Probable phospholipid hydroperoxide glutathione peroxidase protein and superoxide dismutase protein related to response to oxidative stress showed the highest expression level in 5-leaf stage treatment. This suggests that the production of reactive oxygen species by the waterlogging stress was the most abundant in the 5-leaf treatment group, and the expression of the antioxidant defense protein was increased.

Analysis of Actors' Interaction Patterns in the Formation Process of Sexual Crime Prevention Policy: Focusing on classification and case analysis (성범죄예방정책의 형성과정에서 행위자의 상호작용 패턴분석: 유형분류 및 사례분석을 중심으로)

  • Yoo, Keun-Hwan;Kim, Duck-Hwan;Suh, Kyung-Do
    • Journal of the Korea Convergence Society
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    • v.9 no.9
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    • pp.209-215
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    • 2018
  • The purpose of this study is to grasp the overall policy decision system of sex crime prevention policy and analyze the interaction and pattern of actors in policy formation process. This is a useful way to identify the causes and ways to improve the policy if the sex crime prevention policy fails. As a research method, we used a model of advocacy through case analysis and language network analysis. In the external environment, low reporting of sex offenses, technical improvement and supplement for preventive management, consciousness of victims of sexual crimes, amendment of legislation, and support of the president. The conflicts between the advocacy coalition opposed the strong regulation, the prevention of recidivism, the expansion of the range of objects to be worn, the temporary effect of the system and the retrospective of the bill. As a problem-solving strategy, it was confirmed that the opposing positions of pros and cons of lack of manpower and negligence of management through the extension of the system were acutely opposed. In the context of media reports, this tendency is more likely to be understood as the concern of prevention and management at the central government level to prevent sex crimes. Therefore, although the methods of prevention of sex crimes have been insufficient in the past, it is hoped that this study will be helpful in breaking the link of negative policy vicious cycle.

A Study on the Characteristics of Martensitic Transformation Behaviors in In-X(X=Pb,Sn) Alloys (In-X(X=Pb,Sn) 합금의 마르텐사이트변태거동 특성에 관한 연구)

  • Han, Chang-Suk;Han, Seung-Oh
    • Journal of the Korean Society for Heat Treatment
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    • v.23 no.5
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    • pp.233-238
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    • 2010
  • The phase transformations and the shape memory effect in In-rich Pb alloys and In rich-Sn alloys have been studied by means of X-ray diffractometry supplemented by metallographic observations. The alloys containing 12~15 at.%Pb transform from the ${\alpha}_2$ (fct) phase to the ${\alpha}_1$ (fct) phase by way of an intermediate phase (m phase) on cooling. The results of X-ray diffraction show that the metastable intermediate phase is observed both on cooling and heating, and has a face-centered orthorhombic (fco) structure. It is concluded that the ${\alpha}_1{\rightleftarrows}{\alpha}_2$ transformation is expressed by the ${\alpha}_1{\rightleftarrows}m{\rightleftarrows}{\alpha}_2$ transformation both on usual cooling and heating with the rate more than $8{\times}10^{-3}$ K/s. The $m{\rightleftarrows}{\alpha}_2$ transformation takes place with a mechanism involving macroscopic shear and are of diffusionless (martensitic) type. The temperature hysteresis in the two transformations is 10~13 K between the heating and cooling transformations. The alloys containing 0~11 at.%Sn are -phase solid solutions with a face centered tetragonal structure (c/a > 1) at room temperature, the axial ratio increasing continuously with tin content. The In-(11~15) at.%Sn alloys are mixtures of ${\alpha}$ and ${\beta}$ phases, the ${\beta}$ phase having a f. c. tetragonal structure (c/a < 1). The alloys containing more than 15 at.%Sn are ${\beta}$-phase solid solutions. The In-(12.9~15.0) at.%Sn alloys show a shape memory effect only when quenched to the temperature of liquid nitrogen, although their effect becomes weak and finally disappears after keeping at room temperature for a long time. The ${\beta}{\rightarrow}{\alpha}^{\prime}$ phase transformation is of the diffusionless (martensitic) type, and takes place between 330 K at 12.9 at.%Sn and 150 K at 14.5 at.%Sn. The hysteresis of transformation temperatures on heating and cooling is considerably large (29~40 K), depending on the composition. Both In-Pb and In-Sn alloys showed distinct the shape memory effects.

The Effect of Health Risk Factors on Gender in Early Adolescents: The Application of Logit Analysis (초기청소년대상자의건강위험요인이성별에미치는영향요인분석: 로짓분석의활용)

  • Yoo, Keun-Hwan
    • Journal of Convergence for Information Technology
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    • v.9 no.7
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    • pp.85-93
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    • 2019
  • The purpose of this study is to identify the influence of demographic characteristics such as inappropriate lifestyle, stress, and health status among health risk factors of early adolescents according to gender. There is a gender difference in the perception of mental and physical health of early adolescents, and the result can be different in behavior patterns between men and women. This study was conducted to identify the health risk factors as independent variables for early adolescents in Daegu and Gyeongbuk area, and to analyze the determinants of gender (male, female) differences by parents, family environment, friends, academic background, appearance, grade, location, school grades, family situation, and health status as demographic factors. And, the Odds Ratio of the early adolescents was analyzed through logit analysis and the differences according to the influence relationship of each of them were examined. As a result of the analysis, the more the sleep and physical activity, parents, home environment, friends, academic background, and appearance are increased, the more the influence is likely to become on the male students. On the contrary, the rest of the health risk factors can increase, and the threat to the health risk factors is likely to become severe to the female students.Among them, it is necessary to develop a pre-preventive program for early adolescents' health risk factors, provide basic data for practical application in the field, and seek a detailed program according to the gender of early adolescents.

The Effect of Carbide Precipitation on the High Temperature Deformation of Ni3Al and TiAl

  • Han, Chang-Suk;Kim, Jang-Woo;Kim, Young-Woo
    • Korean Journal of Metals and Materials
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    • v.47 no.3
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    • pp.147-154
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    • 2009
  • The effect of carbon addition on the microstructures and mechanical properties of $Ni_3Al$ and TiAl intermetallic alloys have been characterized. It is shown that carbon is not only an efficient solid solution strengthener in $Ni_3Al$ and TiAl, it is also an efficient precipitation strengthener by fine dispersion of carbide. Transmission electron microscope investigation has been performed on the particle-dislocation interactions in $Ni_3Al$ and TiAl intermetallics containing various types of fine precipitates. In an $L1_2$-ordered $Ni_3Al$ alloy with 4 mol.% of chromium and 0.2~3.0 mol.% of carbon, fine octahedral precipitates of $M_{23}C_6$ type carbide, which has the cube-cube orientation relationship with the matrix, appear during aging. Typical Orowan loops are formed in $Ni_3Al$ containing fine dispersions of $M_{23}C_6$ particles. In the L10-ordered TiAl containing 0.1~2.0 mol.% carbon, TEM observations revealed that needle-like precipitates, which lie only in one direction parallel to the [001] axis of the $L1_0$ matrix, appear in the matrix and preferentially at dislocations. Selected area electron diffraction (SAED) patterns analyses have shown that the needle-shaped precipitate is $Ti_3AlC$ of perovskite type. The orientation relationship between the $Ti_3AlC$ and the $L1_0$ matrix is found to be $(001)_{Ti3AlC}//(001)_{L10\;matrix}$ and $[010]_{Ti3AlC}//[010]_{L10\;matrix}$. By aging at higher temperatures or for longer period at 1073 K, plate-like precipitates of $Ti_2AlC$ with a hexagonal structure are formed on the {111} planes of the $L1_0$ matrix. The orientation relationship between the $(0001)_{Ti2AlC}//(111)_{L10\;matrix}$ is and $[1120]_{Ti2AlC}//[101]_{L10\;matrix}$. High temperature strength of TiAl increases appreciably by the precipitation of fine carbide. Dislocations bypass the carbide needles at further higher temperatures.

U.S. Commercial Space Traffic Management Policy, Yesterday and Today (미국의 민간(상업) 우주교통관리(Space Traffic Management, STM) 정책과 한국에의 시사점)

  • Kim, Syeun;Jung, Yungjin
    • Journal of Space Technology and Applications
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    • v.1 no.1
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    • pp.121-130
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    • 2021
  • Since the 1960s, the United States has developed and implemented policies to encourage commercial space launches. Specifically, national policies have been implementing to expand the role of commercial space actors, which required establishing a process for private space launches. In the early days of the space age, private launches accounted for a small portion of the total launch rate, but, since the 1990s, the proportion has exploded, with private space companies presenting large projects one after another, accounting for more than 50% of the total launch rate. This diversification of space actors and the increase in orbital space objects have led to changes in the perspectives of existing space environmental management processes. During and after the Cold War, when the space age began, civilian actors' actions were limited, and policies limited their actions, too. So they had little impact on government space activities. However, space technology's entry barrier has lowered since, and policies to facilitate commercial space launches have been implemented for a long, and the accumulated amount of space waste over the past 60 years is also threatening the safety, stability, and sustainability of space use. This paper examined how the United States, the most active country in commercial space launches, has managed commercial space launches. The United States has a Space Traffic Management (STM), distributed to departments such as the Department of Defense, Department of Commerce, Department of Transport, NASA, etc. A review of changes in U.S STM management policy could also provide implications for us to manage commercial space launches in Korea.

Rifle performance improvement cost estimation through Relation between the accuracy and Engagement results Using the Engagement class simulation model (명중률과 교전결과의 상관관계분석을 통한 개인화기 성능개선비용 추정 : 교전급 분석모델을 중심으로)

  • TaeKyeom Kim
    • The Journal of the Convergence on Culture Technology
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    • v.10 no.1
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    • pp.289-295
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    • 2024
  • This study analyzes the correlation between the accracy of rifle and the result of engagement. And estimates the improvement cost of the rifle accordingly. For this experiment, an engagement class simulation model(AWAM: Army Weapon Effectiveness Analysis Model) was used. We also selected the rifle, which is a portable weapon for the experiment. Prior to this experiment, we conducted a reliability test(VV&A: Verification, Validation and Accreditation) on the model. The VV&A process is mainly done during the development of the DM&S model, which is also necessary for the operation of the M&S. We confirmed the need for VV&A during the experiment and obtained reliable experimental results using the corrected values. In the Accuracy Experiment we found that the 20% improvement is the most effective. And we were able to estimate the cost of acquiring a rifle with a 20% higher accuracy. The cost was estimated by simple regression analysis based on the price of the current rifle. Through this study, we could know the impact of the accuracy of rifle on the experimental results and estimate the cost of improved rifle.