• Title/Summary/Keyword: Unprecedented

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Design and Manufacturing of Mechanical Metamaterials: A Review (기계적 메타물질 설계 및 제조방안)

  • Kim, Min-Kyeom;Kim, Seunghyun;Yun, Jae-Won;Jeong, Hyo Gyun;Kwak, Min-Jun;Ahn, Yea-Lin;Park, Chan-Wook;Kim, Youn-Chul;Suhr, Jonghwan
    • Composites Research
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    • v.34 no.4
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    • pp.199-211
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    • 2021
  • As an additive manufacturing achieves technological advances, it enables to manufacture complex structures with saving a cost and time. Therefore, metamaterials, which has geometric complexity, have gradually gathered attention due to the unprecedented properties: the unprecedented mechanical, thermal, electromagnetic, and optical properties. The metamaterials could exhibit a high potential in engineering applications, and thus it has been steadily investigated to design or/and develop novel metamaterials. Here, mechanical metamaterials, which had been reported, were reviewed to suggest the way to design and fabricate the metamaterials for industrial applications.

Polymeric Nano-materials: Applications & Research Trends (고분자 나노 소재의 응용 및 연구 현황)

  • 박영준
    • Journal of the Society of Cosmetic Scientists of Korea
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    • v.28 no.2
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    • pp.55-57
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    • 2002
  • The fabrication, characterization and manipulation of nanosystems brings together physics, chemistry, materials science and biology in an unprecedented way, Phenomena occurring in such systems are fundamental to the workings of electronic devices, but also to living organisms. The ability to fabricate nanostructures is essential in the further development of functional devices that incorporate nanoscale features. Even more essential is the ability to introduce a wide range of chemical and materials flexibility into these structures to build up more complex nanostructures that can ultimately rival biological nanosystems. In this respect, polymers are potentially ideal nanoscale building blocks because of their length scale, well-defined architecture, controlled synthesis, ease of processing and wide range of chemical functionality that can be incorporated. In this presentation, we will look at a number of promising polymer-based nanofabrication strategies that have been developed recently, with an emphasis on those techniques that incorporate nanostructured polymers into devices and that exploit intrinsic polymer properties.

VLBI Phase Referencing and Astrometry with KVN and KaVA

  • Jung, Taehyun;Byun, Do-Young;Sohn, Bong Won
    • The Bulletin of The Korean Astronomical Society
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    • v.40 no.1
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    • pp.54.2-54.2
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    • 2015
  • Phase referencing is an important tool to study weak radio sources, especially in mm-VLBI (Very Long Baseline Interferometry) which are usually too faint to be observed using conventional VLBI. VLBI astrometry is a unique method to measure the position and to identify radio emitting regions of a radio source with unprecedented angular resolution. In order to evaluate the phase referencing and astrometric capabilities of KVN and KaVA, several observations have been conducted and analyzed. I will present the observational results and discuss constraints and requirements for high precision VLBI astrometry.

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Population Ageing Crisis and Causal loop Analysis on the It's Dynamics in Rural County Regions (우리나라 군지역의 고령화 위기와 동태성의 인과순환적 구조분석)

  • Choi, Nam Hee;Lee, Jong Kun;Kim, Keun Sei;Lee, Myung Suk
    • Korean System Dynamics Review
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    • v.15 no.1
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    • pp.75-96
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    • 2014
  • This research primarily aims at analyzing major crises originating from marginalizing population, especially in counties. In addition, based on the system dynamics approaches, it pays attention to divulging causal loop structure which has been rather strengthened by diverse interactions among key variables. Judging from simulation works, even though Korea is exposed to unprecedented aging trends over decades, its counter response seems inadequate and insufficient, mostly dismissing a series of impact embedded in the aging dynamics. This research statistically confirms that demographic marginalization trends have already begun in the villages within Eup and Myon counties. Furthermore, this research pinpoints out the fact that it would be almost impossible for majority of villages within Eup and Myon counties to escape from going out of existence in the course of time, as they tend to be entrapped vicious cycle of marginalization or extinction.

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Real-Time Sensor Monitoring Service based on ECA (ECA 기반 센서 네트워크 실시간 모니터링 서비스)

  • Kim, Jung-Yee
    • Journal of Korea Multimedia Society
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    • v.15 no.1
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    • pp.87-92
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    • 2012
  • Wireless sensor network is a technology that collects the information about object in real-time. Sensor data has a characteristic that is generated an unprecedented volume data in short time. Analysis is essential to define the relationship between the data, including more of the data from a large volume data stream which is acquired from the sensor. In order to effectively handle the sensor data stream, in this paper, using ECA rules to organize data in a meaningful and more practical real-time monitoring systems is proposed.

SUPERNOVA REMNANTS IN THE AKARI FIS ALL-SKY SURVEY

  • Jeong, Il-Gyo;Koo, Bon-Chul;Lee, Ho-Gyu
    • Publications of The Korean Astronomical Society
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    • v.27 no.4
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    • pp.235-236
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    • 2012
  • We carry out a systematic study of Galactic supernova remnants (SNRs) using the AKARI Far Infrared Surveyor (FIS) survey data. The AKARI Infrared Astronomical Satellite observed the whole sky using the four FIS bands covering 50 to 180 microns with ~1 arcmin resolution. The all-sky coverage with high-spatial resolution provides an unprecedented opportunity to study diffuse, extended far-infrared (FIR) sources such as SNRs. We have searched for FIR counterparts to all 274 known Galactic SNRs, and investigate their FIR properties of identified SNRs. We report preliminary results of the study.

A Ten-Year Analytical Comparative Study on the International Journal of Consumer Studies

  • Shin, Dongjin
    • Journal of Distribution Science
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    • v.12 no.7
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    • pp.63-75
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    • 2014
  • Purpose - This study analyzes topics discussed in the International Journal of Consumer Studies through a content analysis, to reveal the impact of cross-cultural management in consumer research. Research Design, Data, and Methodology - The International Journal of Consumer Studies has the highest impact factor among international consumer journals, and was chosen for research. This study investigated 712 articles, covering a ten-year period. Results - A total of 82 articles were found to be related to cross-cultural management, out of 712 articles. This shows a need for improvement in the area of cross-cultural management, and implies that the discipline of cross-cultural management will continue to have a significant impact on consumer studies. Conclusions - While content analyses have been conducted in the area of consumer research in the past, a comparative content analysis in the International Journal of Consumer Studies is unprecedented. This study offers insights on the comparative analysis of general articles and articles related to cross-cultural management, which will be useful reference points for future global markets and fields in distribution and consumer research.

Nanocrystals and Their Biomedical Applications

  • Jun, Young-wook;Jang, Jung-tak;Cheon, Jin-woo
    • Bulletin of the Korean Chemical Society
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    • v.27 no.7
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    • pp.961-971
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    • 2006
  • Shape controlled synthesis of inorganic nanocrystals is one of the important issues in materials chemistry due to their novel shape dependent properties. Although various shapes of nanocrystals have been developed, a systematic account on the shape control of these nanocrystals still remains an important subject in materials chemistry. In this article, we will overview the recent developments in the geometrical shape evolution of semiconductor and metal oxide nanocrystals obtained by nonhydrolytic synthetic methods. Many structurally unprecedented motifs have appeared as zero-dimesional (D) polyhedrons, one-D rods and wires, two-D plates and prisms, and other advanced shapes such as branched rods, stars, and inorganic dendrites. Important parameters which determine the geometrical shapes of nanocrystals are also illustrated. In addition, as a possible application of such nanocrystals for biomedical sciences, we further describe their utilizations for cancer diagnosis through nanocrystal-assisted magnetic resonance imaging (MRI).

Multi-stream Delivery Method of the Video Signal based on Wavelet (웨이브릿 기반 비디오 신호의 멀티 스트림 전송 기법)

  • 강경원;류권열;권기룡;문광석;김문수
    • Proceedings of the IEEK Conference
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    • 2001.06c
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    • pp.101-104
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    • 2001
  • Over the last few years, streaming audio and video content on Internet sites has increased at unprecedented rates. The predominant method of delivering video over the current Internet is video streaming such as SureStream or Intelligent Stream. Since each method provides the client with only one data stream from one server, it often suffers from poor qualify of pictures in the case of network link congestion. In this paper, we propose a novel method of delivering video stream based on wavelet to a client by utilizing multi-threaded parallel connections from the client to multiple servers and to provides a better way to address the scalability functionalities. The experimental results show that the video quality delivered by the proposed multithreaded stream could significantly be improved over the conventional single video stream methods.

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Performance analysis of a MAC Protocol on WDM Non-Slotted Ring (Fixed Length Packet) Network (Non-Slotted Ring (Fixed Length Packet) 구조를 가지는 WDM 광 네트워크의 성능 분석)

  • 정지훈;김종훈
    • Proceedings of the IEEK Conference
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    • 2000.06a
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    • pp.229-231
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    • 2000
  • Nowadays, the telecommunication service provider has witnessed an unprecedented growth in data traffic and the need for networking. optical fiber can provide some THz of huge bandwidth WDM technology has been an emerging issue for the efficient use of optical links. WDM uses a number of different wavelength that are assigned to each channel. The minimal number of optical transceivers and receivers should be used in a node to build an economic WDM transmission system without degrading system performance. Hence, the analysis of performance parameters such as throughput and delay is important to guarantee the WDM system performance. in this paper, the performance of a MAC protocol on a slotted WDM system that has a tunable transmitter(Txt), a tunable receiver(Rxt), and a fixed receiver(Rxf), respectively, on each node, was statistically analyzed The computer simulation validates the performance analysis.

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