• Title/Summary/Keyword: Small target

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Modeling and Experimental Verification of Echo Characteristics of 3 Dimensional Underwater Target (3차원 수중 표적의 반향특성 모델링과 실험적 검증)

  • You, Seung-Ki;Kim, Sunhyo;Choi, Jee Woong;Kang, Donhyug;Jeong, Dongmin
    • The Journal of the Acoustical Society of Korea
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    • v.33 no.3
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    • pp.174-183
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    • 2014
  • When a active sonar signal is transmitted and returned back from a target, it has been distorted by various properties of acoustic channel such as multipath arrivals. And signals have been appeared to be different form by target position and attitude. Therefore, we simulated the target echo signal using 3 dimensional target model include reflects target features. In this paper, we develop components form of a simulated target model is made up equally spaced highlight points, and each part of the target consists of shape function. We can simulate a target echo signal and Target strength (TS) according to wave incident angle. To verify, we made small scale target in kit form and we had got underwater target signal for comparing simulation result in water tank.

An Empirical Study on the Core Competences for Development of Global Small Giant Companies (글로벌 강소기업 육성을 위한 핵심역량에 관한 실증연구)

  • Park, Woojong;Park, Kwang-Ho
    • Journal of Korean Society of Industrial and Systems Engineering
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    • v.35 no.4
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    • pp.202-210
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    • 2012
  • This study was analyzed based on the core competencies that Small Giant enterprises to foster the goals of growth of SMEs mid-sized businesses rather than Global Small Giant enterprises of the business model for a causal relationship. As the result, the average age, sales and number of employees of Korean small giants were 20.6 years, 148.8 billion won and 312.1. This research investigated that Korean small giants were realizing the sustainable growth with the firm shares in the target markets, based on added values in groups and technical powers, although their average age is one third younger than global small giants. The further research needs to develop and select small giants more precisely and strictly. It is expected that small giants will be new growth engines to improve global competitiveness of Korea.

Shoe Storage for Small Space (좁은공간에서의 신발장디자인)

  • Wang, Kang-Lin;Lee, Sung-Pil;Hyoung, Sung-Eun
    • Proceedings of the Korean Society for Emotion and Sensibility Conference
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    • 2008.10a
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    • pp.151-154
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    • 2008
  • The purpose of this research project is to provide information on emotional design and designs a kind of shoe storage for small space. Through researching the activities of target user and analyzing the present market, we get the clear understanding of direction for storage design, and create a new domain of for storages, with its added value and competition too. This will satisfy demand of consumers and benefit for enterprise.

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A Study on the Characteristic of Small Housing for 1-2 Person Households - Focused on the Entries of the Idea Competition in order to Target College Students - (1-2인 가구를 위한 소규모 주택의 계획론적 특성에 관한 연구 - 대학생 대상 서울시 아이디어공모전 출품작을 중심으로 -)

  • Baek, Ji-Sook;Yi, Yong-Kyu
    • Journal of the Korean housing association
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    • v.23 no.3
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    • pp.63-70
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    • 2012
  • Nowadays, a 1-2 person household if increasing due to the aging population and the low birth rate. Thus, in August 2011, Seoul held the 'College Student's Idea Competition', which dealt with small but strong housing that has a very reasonable structure in spite of its small scale in order to improve the quality of small housing for a 1-2 person households. The study indicates the characteristic of this small housing in order to target competition entries from college students; 93- works have been processed. First, the properties of residents are investigated through the number of household members and the relations of the residents. To ensure various element techniques of the entries, the study analyzes data via a structured analysis. Along with structured element techniques according to each level, eight element techniques of the furniture level, housing unit level, main building, and district-level are derived. This study suggests various element techniques in response to the efficiency of area in households as well as housing unit levels. Plans of public spaces and community life housing are offered at the level of the main building and at the district-level. Through an analysis of competition, the critical point of small house planning in deliberation is not only about space and economic efficiency of physical unit, but the life of the residents.

Feasibility Study of Beta Detector for Small Leak Detection inside the Reactor Containment

  • Jang, JaeYeong;Schaarschmidt, Thomas;Kim, Yong Kyun
    • Journal of Radiation Protection and Research
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    • v.43 no.4
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    • pp.154-159
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    • 2018
  • Background: To prevent small leakage accidents, a real-time and direct detection system for small leaks with a detection limit below that of existing systems, e.g. $0.5gpm{\cdot}hr^{-1}$, is required. In this study, a small-size beta detector, which can be installed inside the reactor containment (CT) building and detect small leaks directly, was suggested and its feasibility was evaluated using MCNPX simulation. Materials and Methods: A target nuclide was selected through analysis of radiation from radionuclides in the reactor coolant system (RCS) and the spectrum was obtained via a silicon detector simulated in MCNPX. A window was designed to reduce the background signal caused by other nuclides. The sensitivity of the detector was also estimated, and its shielding designed for installation inside the reactor CT. Results and Discussion: The beta and gamma spectrum of the silicon detector showed a negligible gamma signal but it also contained an undesired peak at 0.22 MeV due to other nuclides, not the $^{16}N$ target nuclide. Window to remove the peak was derived as 0.4 mm for beryllium. The sensitivity of silicon beta detector with a beryllium window of 1.7 mm thickness was derived as $5.172{\times}10^{-6}{\mu}Ci{\cdot}cc^{-1}$. In addition, the specification of the shielding was evaluated through simulations, and the results showed that the integrity of the silicon detector can be maintained with lead shielding of 3 cm (<15 kg). This is a very small amount compared to the specifications of the lead shielding (600 kg) required for installation of $^{16}N$ gamma detector in inside reactor CT, it was determined that beta detector would have a distinct advantage in terms of miniaturization. Conclusion: The feasibility of the beta detector was evaluated for installation inside the reactor CT to detect small leaks below $0.5gpm{\cdot}hr^{-1}$. In future, the design will be optimized on specific data.

MicroRNA Target Recognition: Insights from Transcriptome-Wide Non-Canonical Interactions

  • Seok, Heeyoung;Ham, Juyoung;Jang, Eun-Sook;Chi, Sung Wook
    • Molecules and Cells
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    • v.39 no.5
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    • pp.375-381
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    • 2016
  • MicroRNAs (miRNAs) are small non-coding RNAs (~22 nucleotides) regulating gene expression at the post-transcriptional level. By directing the RNA-induced silencing complex (RISC) to bind specific target mRNAs, miRNA can repress target genes and affect various biological phenotypes. Functional miRNA target recognition is known to majorly attribute specificity to consecutive pairing with seed region (position 2-8) of miRNA. Recent advances in a transcriptome-wide method of mapping miRNA binding sites (Ago HITS-CLIP) elucidated that a large portion of miRNA-target interactions in vivo are mediated not only through the canonical "seed sites" but also via non-canonical sites (~15-80%), setting the stage to expand and determine their properties. Here we focus on recent findings from transcriptome-wide non-canonical miRNA-target interactions, specifically regarding "nucleation bulges" and "seed-like motifs". We also discuss insights from Ago HITS-CLIP data alongside structural and biochemical studies, which highlight putative mechanisms of miRNA target recognition, and the biological significance of these non-canonical sites mediating marginal repression.

Dual-Target Gene Silencing by Using Long, Synthetic siRNA Duplexes without Triggering Antiviral Responses

  • Chang, Chan Il;Kang, Hye Suk;Ban, Changill;Kim, Soyoun;Lee, Dong-ki
    • Molecules and Cells
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    • v.27 no.6
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    • pp.689-695
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    • 2009
  • Chemically synthesized small interfering RNAs (siRNAs) can specifically knock-down expression of target genes via RNA interference (RNAi) pathway. To date, the length of synthetic siRNA duplex has been strictly maintained less than 30 bp, because an early study suggested that double-stranded RNAs (dsRNAs) longer than 30 bp could not trigger specific gene silencing due to the induction of non-specific antiviral interferon responses. Contrary to the current belief, here we show that synthetic dsRNA as long as 38 bp can result in specific target gene silencing without non-specific antiviral responses. Using this longer duplex structure, we have generated dsRNAs, which can simultaneously knock-down expression of two target genes (termed as dual-target siRNAs or dsiRNAs). Our results thus demonstrate the structural flexibility of gene silencing siRNAs, and provide a starting point to construct multifunctional RNA structures. The dsiRNAs could be utilized to develop a novel therapeutic gene silencing strategy against diseases with multiple gene alternations such as viral infection and cancer.

Study on the Functional Architecture and Improvement Accuracy for Auto Target Classification on the SAR Image by using CNN Ensemble Model based on the Radar System for the Fighter (전투기용 레이다 기반 SAR 영상 자동표적분류 기능 구조 및 CNN 앙상블 모델을 이용한 표적분류 정확도 향상 방안 연구)

  • Lim, Dong Ju;Song, Se Ri;Park, Peom
    • Journal of the Korean Society of Systems Engineering
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    • v.16 no.1
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    • pp.51-57
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    • 2020
  • The fighter pilot uses radar mounted on the fighter to obtain high-resolution SAR (Synthetic Aperture Radar) images for a specific area of distance, and then the pilot visually classifies targets within the image. However, the target configuration captured in the SAR image is relatively small in size, and distortion of that type occurs depending on the depression angle, making it difficult for pilot to classify the type of target. Also, being present with various types of clutters, there should be errors in target classification and pilots should be even worse if tasks such as navigation and situational awareness are carried out simultaneously. In this paper, the concept of operation and functional structure of radar system for fighter jets were presented to transfer the SAR image target classification task of fighter pilots to radar system, and the method of target classification with high accuracy was studied using the CNN ensemble model to archive higher classification accuracy than single CNN model.

Performance Evaluation of D2D Advertisement Dissemination Algorithm for Isolated High User-Density Area (고립된 사용자 밀집지역을 위한 D2D 광고 확산 알고리즘 성능 분석)

  • Kim, Junseon;Lee, Howon
    • Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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    • 2015.05a
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    • pp.40-42
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    • 2015
  • Our D2D (Device-to-Device) advertisement dissemination algorithm based on the convergence of a D2D communication and a social commerce service is able to efficiently deliver advertisement messages of small business owners. We here assume high user-density areas as target-areas, and these target areas can form several target-groups based on geographical proximity. Also, the isolated target-areas which are not included in the target-groups may have the opportunities for forming a new target-group in consideration of the maximum distance with AP. In this paper, we evaluate performances with respect to the total number of successfully received users and the average number of relay users in accordance with variation in the maximum distance for isolated target-areas.

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Distance Measurement of Small Moving Object using Infrared Stereo Camera (적외선 스테레오 카메라를 이용한 소형 이동체의 거리 측정)

  • Oh, Jun-Ho;Lee, Sang-Hwa;Lee, Boo-Hwan;Park, Jong-Il
    • Journal of the Institute of Electronics Engineers of Korea SC
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    • v.49 no.3
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    • pp.53-61
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    • 2012
  • This paper proposes a real-time distance measurement system of high temperature and high speed target using infrared stereo camera. We construct an infrared stereo camera system that measure the difference between target and background temperatures for automatic target measurement. First, the proposed method detects target region based on target motion and intensity variation of local region using difference between target and background temperatures. Second, stereo matching by left and right target information is used to estimate disparity about real-time distance of target. In the proposed method using infrared stereo camera system, we compare distances in three dimension trajectory measuring instrument and in infrared stereo camera measurement. In this experiment from three video data, the result shows an average 9.68% distance error rate. The proposed method is suitable for distance and position measurement of varied targets using infrared stereo system.