• Title/Summary/Keyword: Large target

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Multiple characteristic response damage analysis of large-span space structures based on equivalent damping ratio

  • Wei, Jun;Yang, Qingshun;Zhou, Lexiang;Chen, Fei
    • Earthquakes and Structures
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    • v.23 no.4
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    • pp.339-352
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    • 2022
  • Due to the large volume and generally as a public building, the damage of large-span space structures under various non-conventional loads will cause greater economic losses, casualties, and social impacts, etc. Therefore, it is particularly important to evaluate the seismic performance of large-span space structures. This paper taked a multipurpose sports center as an example and considered its synergistic deformation based on the method of equivalent damping ratio. Furthermore, The ABAQUS software was used to analyze the time-history and energy response of the multipurpose sports center under the action of rare earthquakes, and proposed a quantitative damage index to assess the overall damage of the structure. Finally, the research results indicated that the maximum inter-story drift ratio of the multipurpose sports center under the action of rare earthquakes was less than its limit value. The frame beams presented different degrees of damage, but the key members were basically in an elastic state. The bearing capacity did not reach the limit value, which satisfied the intended seismic performance target. This study taked an actual case as an example and proposed a relevant damage evaluation system, which provided some reference for the analysis of the seismic performance of large-span space structures.

A Study on the Analysis and the Test of the Reflected Signal about Target in the VHF Band (초단파 대역의 표적 반사 신호 시험 및 분석에 대한 연구)

  • Kim, Ki-Jung
    • The Journal of the Korea institute of electronic communication sciences
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    • v.15 no.5
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    • pp.813-818
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    • 2020
  • This study is a study on the characteristics and analysis of the reflected signals about the target in the VHF band. In advance, the RCS(Radar Cross Section) characteristics of the target were analyzed by using the CST electromagnetic analysis tool, and the target was detected by using the Bi-Static method, and the change in the signal-to-noise ratio was tested. The test results show similar results with no significant fluctuations in the signal-to-noise ratio characteristics for the detection of signals reflected on the target, such as the results for RCS analysis according to the pre-incidence angle. In the future, this study will be used for RCS analysis of the targets and target detection of Radar in VHF/UHF band with relatively large wavelength compared to the X band.

Development of a Comprehensive Performance Test Facility for Small Millimeter-wave Tracking Radar (소형 추적 레이다용 종합성능시험 시설 개발)

  • Kim, Hong-Rak;Kim, Youn-Jin;Woo, Seon-Keol;An, Se-Hwan
    • The Journal of the Institute of Internet, Broadcasting and Communication
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    • v.20 no.3
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    • pp.121-127
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    • 2020
  • The small tracking radar targets the target in a real-time, fast-moving, fast-moving target against aircraft with a large RCS that is maneuvering at low speed and a small RCS aircraft maneuvering at high speed (fighters, drones, helicopters, etc.) It is a pulsed radar that detects and tracks. Performing a performance test on a tracking radar in a real environment is expensive, and it is difficult to quantitatively measure performance in a real environment. Describes the composition of the laboratory environment's comprehensive performance test facility and the main requirements and implementation of each configuration.Anechoic chambers to simulate the room environment, simulation target generator to simulate the signal of the room target, target It is composed of a horn antenna driving device to simulate the movement of a vehicle and a Flight Motion Simulatior (FMS) to simulate the flight environment of a tracking radar, and each design and implementation has been described.

A New Snake Model for Tracking a Moving Target Using a Mobile Robot (로봇의 이동물체 추적을 위한 새로운 확장 스네이크 모델)

  • Han, Young-Joon;Hahn, Hern-Soo
    • Journal of the Korean Institute of Intelligent Systems
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    • v.14 no.7
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    • pp.838-846
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    • 2004
  • In the case where both a camera and a target are moving at the same time, the image background is successively changed, and the overlap with other moving objects is apt to be generated. The snake algorithms have been variously used in tracking the object, but it is difficult to be applied in the excessive overlap with other objects and the large bias between the snake and the target. To solve this problem, this paper presents an extended snake model. It includes an additional energy function which considers the temporal variation rate of the snake's area and a SSD algorithm which generates the template adaptive to the snake detected in the previous frame. The new energy function prevents the snake from over-shrinking or stretching and the SSD algorithm with adaptively changing template allows the prediction of the target's position in the next frame. The experimental results have shown that the proposed algorithm successfully tracks the target even when the target is temporarily occluded by other objects.

Visualizing Live Chromatin Dynamics through CRISPR-Based Imaging Techniques

  • Chaudhary, Narendra;Im, Jae-Kyeong;Nho, Si-Hyeong;Kim, Hajin
    • Molecules and Cells
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    • v.44 no.9
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    • pp.627-636
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    • 2021
  • The three-dimensional organization of chromatin and its time-dependent changes greatly affect virtually every cellular function, especially DNA replication, genome maintenance, transcription regulation, and cell differentiation. Sequencing-based techniques such as ChIP-seq, ATAC-seq, and Hi-C provide abundant information on how genomic elements are coupled with regulatory proteins and functionally organized into hierarchical domains through their interactions. However, visualizing the time-dependent changes of such organization in individual cells remains challenging. Recent developments of CRISPR systems for site-specific fluorescent labeling of genomic loci have provided promising strategies for visualizing chromatin dynamics in live cells. However, there are several limiting factors, including background signals, off-target binding of CRISPR, and rapid photobleaching of the fluorophores, requiring a large number of target-bound CRISPR complexes to reliably distinguish the target-specific foci from the background. Various modifications have been engineered into the CRISPR system to enhance the signal-to-background ratio and signal longevity to detect target foci more reliably and efficiently, and to reduce the required target size. In this review, we comprehensively compare the performances of recently developed CRISPR designs for improved visualization of genomic loci in terms of the reliability of target detection, the ability to detect small repeat loci, and the allowed time of live tracking. Longer observation of genomic loci allows the detailed identification of the dynamic characteristics of chromatin. The diffusion properties of chromatin found in recent studies are reviewed, which provide suggestions for the underlying biological processes.

Analysis of Women's Pants Sizing Systems of RTW Brands and Development of Sizing Systems by Age Groups (국내 여성복 브랜드의 바지 치수체계 분석 및 연령 집단별 치수체계 설정에 관한 연구)

  • Baek, Hye Yoon;Song, Hwa Kyung
    • Fashion & Textile Research Journal
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    • v.20 no.6
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    • pp.733-743
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    • 2018
  • This study aimed to investigate whether women's wear brands' sizing systems for pants item are reflecting body size and shape of their target age customers. This study classified 17 women's wear brands into three target age groups (20-30s, 30-40s, and 40-50s) and surveyed their body sizing systems of pants item. Distribution of waist circumference and hip circumference of brands' sizing systems were compared with size distribution of women in the 7th Size Korea data. The sizing systems of brands targeting 20-30s covered 28.3% and those of brands targeting 40-50s covered 27.3%, while those of brands targeting 30-40s covers 46.6%. Regarding the body types, 80% of 20-30s target brands reflected normal type which is the average body type. However, all 40-50s target brands reflected normal type while 57.8% of women aged 40-50s had large waist shape. The 30-40s target brands reflected body types the best among target age groups since the body shape distribution of the brands was similar to that of 30-40 year old woman in Size Korea. For each age group, 6 sizes with 25.2~27.8% coverage rates were proposed. The 70-91, 73-91, 73-94 sizes were overlapped between the 20-30s and the 30-40s groups. The 76-91, 76-94, 79-94 sizes were overlapped between the 30-40s and 40-50s groups. Pants size has been found to increase in waist circumference compared to hip circumference as age increased.

Designing 3D Antenna Pattern using Target's RCS Pattern (RCS 패턴을 이용한 3차원 안테나 패턴 디자인)

  • Park, Tae-Yong
    • Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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    • 2022.10a
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    • pp.194-196
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    • 2022
  • When electromagnetic wave transmitted from the radar antenna hits the target, a specific type of electric field is formed according to the electrical characteristics and appearance of the target, which is called an RCS pattern. There are various commercial programs that calculate the RCS of the target and plot the RCS pattern. For the analysis of large targets such as warships or ships, a program with a high frequency analysis method, which has a faster calculation speed than the low frequency analysis method is suitable. XGTD, a high-frequency analysis program, can quickly plot a two-dimensional RCS pattern for 360 degrees of a target, but a three-dimensional RCS pattern cannot be obtained. In this paper, it is proposed that a method of plotting two-dimensional RCS patterns of a target from various angles using XGTD, generating a three-dimensional RCS pattern using this, and converting it into a three-dimensional antenna pattern file.

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Analysis of Target Identification Performances Using Bistatic ISAR Images (바이스태틱 ISAR 영상을 이용한 표적식별 성능 분석)

  • Lee, Seung-Jae;Lee, Seong-Hyeon;Kang, Min-Seok;Yang, Eunjung;Kim, Kyung-Tae
    • The Journal of Korean Institute of Electromagnetic Engineering and Science
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    • v.27 no.6
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    • pp.566-576
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    • 2016
  • Inverse synthetic aperture radar(ISAR) image generated from bistatic radar(Bi-ISAR) represents two-dimensional scattering distribution of a target, and the Bi-ISAR can be used for bistatic target identification. However, Bi-ISAR has large variability in scattering mechanisms depending on bistatic configurations and do not represent exact range-Doppler information of a target due to inherent distortion. Thus, an efficient training DB construction is the most important factor in target identification using Bi-ISARs. Recently, a database construction method based on realistic flight scenarios of a target, which provides a reliable identification performance for the monostatic target identification, was applied to target identification using high resolution range profiles(HRRPs) generated from bistatic radar(Bi-HRRPs), to construct efficient training DB under bistatic configurations. Consequently, high identification performance was achieved using only small amount of training Bi-HRRPs, when the target is a considerable distance away from the bistatic radar. Thus, flight scenarios based training DB construction is applied to target identification using Bi-ISARs. Then, the capability and efficiency of the method is analyzed.

A Study on the Improvement on the Target Structure in a Magnetron Sputtering Apparatus (마그네트론 스퍼터링 장치의 타겟구조 개선에 관한 연구)

  • Bae, Chang-Hwan;Lee, Ju-Hee;Han, Chang-Suk
    • Journal of the Korean Society for Heat Treatment
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    • v.23 no.1
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    • pp.23-28
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    • 2010
  • The cylindrical magnetron sputtering has not been widely used, although this system is useful for only certain types of applications such as fiber coatings. This paper presents electrode configurations which improved the complicacy of the target assembly by using the positive voltage power supply. It is a modified type which has a target constructed with a large cylindrical part, a conical part and a small cylindrical part. When positive voltage was applied to an anode, a stable glow discharge was established and a high deposition rate was obtained. The substrate bias current was monitored to estimate the effect of ion bombardment. As a result, it was found that the substrate current was large. With cylindrical and conical cathode magnetron sputter deposition on the surface of the substrate to prevent re-sputtering, ion impact because it can increase the effectiveness with excellent ductility and adhesion of Ti film deposition can be obtained. We board at the front end of the ground resistance of $5\;k{\Omega}$ attached to the substrate potential can be controlled easily, and Ti film deposition with excellent adhesion can be obtained. Microstructure and morphology of Ti films deposited on pure Cu wires were investigated by scanning electron microscopy in relation to preparation conditions. High level ion bombardment was found to be effective in obtaining a good adhesion for Cu wire coatings.

A Study on Target Ages and Sizes of Korean Women′s Ready-made Clothes (한국 성인여자 기성복 브랜드의 타깃 연령 및 생산사이즈에 관한 실태조사 연구)

  • 조영아
    • The Research Journal of the Costume Culture
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    • v.8 no.4
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    • pp.549-561
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    • 2000
  • The purpose of this study was to survey and analyze the age classification of women customers as a target market and sizes on a label that were actually produced by each brand in Korean national brands ; they were classified into size for bodice and bottom, and compared with the distribution of national data of women's body measurement. They were analyzed and classified by brand groups of 'miss', 'missy', 'Mrs.'and 'madam', The results were ; 1) It was found that recent products for ready-made for women's clothes tend to be designed with target to the measured ages classified by the range of five or ten years. The main practice was that for 'miss'brand group the age range was of five years, and for 'missy'brand group, ten years. And for 'Mrs'and 'madam'brand groups, it was of 15 or 20 years. So that, it is necessary to design their clothes based on their features of body considering the intervals of age. 2) 'Mrs'and 'madam'groups were most remarkable for their distribution into a vast range of sizes for three control dimensions and waist girth size when compared to 'miss'and 'missy'groups. The distribution of brand size had no relation with that of body measurement, and in particular, none was produced for short height size between 145 and 150 ㎝. For tall height size between 175 and 180 ㎝, many brand sizes were distributed while body measurement was few. It means that distribution of brand size was different from real distribution of body measurement was few. It means that distribution of brand size was different from real distribution of body measurement as a result that the larger the bust girth in such cases over 160 ㎝, the larger the size of hip girth. Even as for the height 155 and 160 ㎝ in which body measurement is concentrated, there were many problems because while sizes of 'large'bust girth and 'small'hip girth had a large distribution, their clothes were not produced.

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