• Title/Summary/Keyword: space technology

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The molten KOH/NaOH wet chemical etching of HVPE-grown GaN (HVPE로 성장된 GaN의 용융 KOH/NaOH 습식화학에칭)

  • Park, Jae Hwa;Hong, Yoon Pyo;Park, Cheol Woo;Kim, Hyun Mi;Oh, Dong Keun;Choi, Bong Geun;Lee, Seong Kuk;Shim, Kwang Bo
    • Journal of the Korean Crystal Growth and Crystal Technology
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    • v.24 no.4
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    • pp.135-139
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    • 2014
  • The hydride vapor phase epitaxy (HVPE) grown GaN samples to precisely measure the surface characteristics was applied to a molten KOH/NaOH wet chemical etching. The etching rate by molten KOH/NaOH wet chemical etching method was slower than that by conventional etching methods, such as phosphoric and sulfuric acid etching, which may be due to the formation of insoluble coating layer. Therefore, the molten KOH/NaOH wet chemical etching is a better efficient method for the evaluation of etch pits density. The grown GaN single crystals were characterized by using X-ray diffraction (XRD) and X-ray rocking curve (XRC). The etching characteristics and surface morphologies were studied by scanning electron microscopy (SEM). From etching results, the optimum etching condition that the etch pits were well independently separated in space and clearly showed their shape, was $410^{\circ}C$ and 25 min. The etch pits density obtained by molten KOH/NaOH wet chemical etching under optimum etching condition was around $2.45{\times}10^6cm^{-2}$, which is commercially an available materials.

A Study on the Necessity of Introducing Evacuation Instrument in High-rise Buildings - Focusing on Elevator Type Evacuation Instrument - (고층건축물의 피난기구 도입 필요성에 관한 연구 - 승강식피난기를 중심으로 -)

  • Choi, Kyu-Chool;Ra, Pan-Ju;Seul, Yeong-Mi
    • Fire Science and Engineering
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    • v.28 no.3
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    • pp.10-19
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    • 2014
  • The fast evacuation from fire floors to evacuation floors in high-rise building fires can minimize the human damage. In this study, an evacuation instrument, which are applicable to the high-rise buildings of adaptable escape mechanisms by the current NFSC 301 (national fire safety code 301), were selected to analyze the applicability in the high-rise buildings over 11th floor through the site adaptability test. The results of the site test were as follows. The elevator type evacuation instrument of new concept developed as a new technology by compensating the defect of evacuation instrument limiting in the high-rise buildings over 11th floor had completed the stability test and the performance certification test in fire stations, which there were no problems in the introduction of the elevator type evacuation instrument as an escape mechanism in the high-rise buildings. The elevator type evacuation instrument using escapers' weight without using electric power was an escape mechanism that many people could evacuate in a short period of time when a fire broke out in the high-rise buildings. In particular, The elevator type evacuation instrument operated by nonpower had the adaptability as a customized escape mechanism considering user characteristics in the buildings for the disabled or patients with an advanced disease.

The risk of the Information-oriented society and the role of private security (정보화 사회의 위험적 요소와 민간시큐리티의 역할)

  • Gong, Bae Wan
    • Journal of the Society of Disaster Information
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    • v.8 no.1
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    • pp.1-9
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    • 2012
  • Informatization of society through the computer and the Internet, because large amounts of information production and exchange and new way of communicating is born. Passive way past the one-sided information flows actively interact to evolve in a manner of information producers and information consumers distinction and personal relationships that enhance the online Social Networking Service (SNS) has developed into the social structure of. Thus, the spread of information work closely with the social network structure spark social conflict may act as a factor, and systems and the environment, personal and cultural adaptation of speed to keep up with the rapid development of science and technology as the inability conflict and confusion should lead to even. This paper the characteristics of the information society, with a look at the evolution of social risk factors as the wavelength of information about this look at the role of private security sought to evaluate. Information Society in time and space by shrinking the area of human life that has brought the convenience and simplicity, whereas the non-performance due to the nature of anonymous raises many social side-effects are. This made the preparation of national regulatory measures, but for the protection of personal protection devices in the private sector has not yet been discussed. Way of life and property of the purchaser to protect an individual's private security will have to charge it.

Evaluation of Protective Performance of Fiber Reinforced Concrete T-Wall (섬유보강 콘크리트 방호벽의 방호성능 향상 검토)

  • Lee, In-Cheol;Kim, Hong-Seop;Nam, Jeong-Soo;Kim, Suk-Bong;Kim, Gyu-Yong
    • Journal of the Korea Institute of Building Construction
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    • v.13 no.5
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    • pp.465-473
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    • 2013
  • Concrete is an outstanding material in terms of its impact and blast resistance performance. However, there a limitation of concrete is its risk of collapse due to the brittle failure and spalling. Increasing the thickness of members was used as a method to enhance the protective performance of concrete, despite the resulting inefficient space. To solve this problem, different types of fiber reinforced concrete were developed. Recently, another type of fiber reinforced concrete is also being developed and applied as a material that offers protection against impacts and blasts by increasing the flexural toughness of concrete. In this study, the test was conducted to evaluate the impact resistance performance of fiber reinforced concrete and mortar according to impact of high-velocity projectile. A concrete T-wall was also tested to evaluate its protective performance from fragment by 155mm-thick artillery shell. The test results revealed that improving flexural strength through fiber reinforcement inhibited cracks and spalling of rear, and spalling of front by high-velocity impact. As such, it is expected to improve the protective performance of the T-wall and reduce the thickness of the member.

Application of Emotional Video Contents Using Car Windows (자동차 윈도우를 활용한 감성 영상콘텐츠 적용 방안)

  • Jung, Su-Young;Choe, Jong-Hoon
    • The Journal of the Korea Contents Association
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    • v.14 no.4
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    • pp.37-46
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    • 2014
  • Industrialization and urbanization have led automobiles to transform into more than just modes of transportation; they have become daily necessities as well as extensions of living spaces where a variety of activities can be done and automotive applications of the latest information technology are accelerated. Though material abundance has increased in the modern society, the conflicts and the stress emerging from a social structure focused on competition have increased as well. Such lifestyles generate a need for personal space and media content for healing the body and the mind. This research explores the automotive application of video content with the goal of refreshing the minds of the passengers. To this end, previous studies have investigated the emotional effect of videos, focusing on the responses of diverse groups of adults (age group of 20 to 60) who frequently used automobiles, which had video displays installed in them. The results showed that watching video contents on a full window inside a car influenced the creation of positive feelings7 and emotional satisfaction. The research attempts to study the methods of providing video contents and the effects of watching them that could aid the emotional well-being of passengers, and presents the possibility of emotional satisfaction created by a convergence of cars and multimedia contents in the future.

Development of real-time monitoring web BBS and the alerts service using mobile web (실시간 웹 게시판 모니터링 및 모바일웹을 이용한 알람 서비스 개발)

  • Kim, Jong-Keun;Sim, Kun-Ho;Lee, Yo-Seb;Lim, Young-Hwan
    • Journal of Digital Contents Society
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    • v.13 no.1
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    • pp.1-11
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    • 2012
  • The BBS of Web Site is a space of informational communication to share information. At the moment, countless information is shared through various kinds of BBS. The shared information through the Web BBS can be gains to someone and losses to the other. Thus, for a long time, there have been many researches about technologies, which monitor information uploaded to Web BBS in real-time and inform the results to subjects. For BBS monitoring, existing methods have utilized direct approaches to DB or open API. Also, e-mail addresses have been utilized to inform results to subjects. However, there are two main problems for these methods. The one is a problem on closed BBS, which cannot be accessed, and the other is impossibility of supporting real-time alarm to e-mail. Especially, the real-time support for services, such as monitoring, is extremely important, since the main purpose of monitoring is based on the counter action for the result. The mobile Web has a merit to be accessed in anywhere, so that it is quite suitable for services requiring real-time support. However, the real-time support of mobile device has not been utilized enough, because each mobile phone has different standards of contents so that the contents should be pre-created. This paper suggests a technology that overcomes pitfalls of mobile Web while it is out of standard, and shows how the effect can be maximized through services such as monitoring, which requires the real-time support.

Development of the Exocarp and Occurrence of Micro-cracking in 'Jinmi' Peaches (복숭아 '진미'의 외과피 발달과 미세균열)

  • Ma, Kyeong-Bok;Chun, Jong-Pil;Kim, Jung-Bae;Do, Kyung-Ran;Cho, Kwang-Sik;Choi, Jin-Ho;Hwang, Hae-Sung
    • Horticultural Science & Technology
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    • v.30 no.1
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    • pp.1-5
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    • 2012
  • This study was conducted to elucidate the cause of micro-cracking in the exocarp of 'Jinmi' peach (Prunus persica). through the microscopic observation of fruit skin development in 4 varieties such as 'Jinmi', 'Kanoiwa Hakuto', 'Kawanakajima Hakuto', and 'Yumyeong'. Micro-cracking was noted in 59.1% of 'Jinmi', 30.6% of 'Kanoiwa Hakuto', 21.5% 'Kawanakajima Hakuto' and 6.4% of 'Yumyeong', respectively. The development of intercellular spaces, which increased rapidly with the fruit development, was easily observed at 69 days after full bloom. Histological studies revealed that the number of outer epiderm cell layers of 'Jinmi' was smaller than that of the other three cultivars, and thinner than the 'Kawanakajima Hakuto' and 'Yumyeong'. Moreover, 'Jinmi' exhibited smaller and flatter shapes in the sub-epidermal cell layer than those of the 'Kawanakajima Hakuto' and 'Yumyeong' at harvest season. Therefore, these results suggest that micro-cracking of 'Jinmi' fruit skin was due to poor-developed outer epidermis and well-developed intercellular spaces just under exocarp as compared with other varieties.

Domestic Research Trends in IT Fashion (IT 패션에 대한 국내 연구 동향)

  • Choo, Ho-Jung;Nam, Yun-Ja;Lee, Yu-Ri;Lee, Ha-Kyung;Lee, Sung-Ji;Lee, Sae-Eun;Jang, Jae-Im;Park, Jin-Hee;Choi, Jin-Woo;Kim, Do-Yuon
    • Fashion & Textile Research Journal
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    • v.14 no.4
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    • pp.614-628
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    • 2012
  • The purpose of this study was to analyze research trends and make suggestions regarding the future of information technology (IT) in the fashion industry. In this study, 437 papers written regarding IT fashion from five major journals published between 2000 and 2011 were examined. The research areas were then organized by subject and keyword, and divided into 16 high-context categories. Two IT fashion maps were constructed, one from a fashion consumer's perspective, and the other based on the fashion industry's supply chain. This study identified important trends in IT fashion such as: 3D scanners, 3D digital renderings of the human form, 3D digital garments, smart garments, mass customization, production automation, online shopping, home shopping, online communities, e-commerce, digital media, virtual reality, e-tail, the digital generation, E-CRM, and education. Data from body scans was collected and applied to production, and research on smart textiles was also carried out. As for IT fashion's service areas, the majority of the research focused on online shopping or online communication. Additionally, research done on avatars and cyber space, and studies on social networking services are shown. The results of this study indicated that a new field of research has opened and that current research has been developing. Also, this study showed what is needed to expand and strengthen IT fashion.

Development of the Local Area Design Module for Planning Automated Excavator Work at Operation Level (자동화 굴삭로봇의 운용단위 작업계획수립을 위한 로컬영역설계모듈 개발)

  • Lee, Seung-Soo;Jang, Jun-Hyun;Yoon, Cha-Woong;Seo, Jong-Won
    • KSCE Journal of Civil and Environmental Engineering Research
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    • v.33 no.1
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    • pp.363-375
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    • 2013
  • Today, a shortage of the skilled operator has been intensified gradually and the necessity of an earthwork in extreme environment operators are difficult to access is increasing for the purpose of resource development and new living space creation. For this reason, an effort to develop an unmanned excavation robot for fully automated earthwork system is continuing globally. In Korea, a research consortium called 'Intelligent Excavation System' has been formed since 2006 as a part of Construction Technology Innovation Program of Ministry of Land, Transport and Maritime Affairs of Korea. Among detailed technologies of the Task Planning System is one of the core technologies of IES, this paper explains research and development process of the Local Area Design Module, which provides informatization unit to create automated excavators' work command information at operation level such as location, range, target, and sequence for excavation work. Designing of Local Area should be considered various influential factors such as excavator's specification, working mechanism, heuristics, and structural stability to create work plan guaranteed safety and effectiveness. For this research, conceptual and detail design of the Local Area is performed for analyzing design element and variable, and quantization method of design specification corresponding with heuristics and structural safety is generated. Finally, module is developed through constructed algorithm and developed module is verified.

A Case Study on the Construction of 3D Geo-spatial Information for Digital Twin Implementation (디지털 트윈 구현을 위한 3차원 공간정보 구축사례 연구)

  • KIM, Seung-Yub;LEE, Ho-Hyun;CHOI, Eun-Soo;GO, Je-Ung
    • Journal of the Korean Association of Geographic Information Studies
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    • v.23 no.3
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    • pp.146-160
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    • 2020
  • In the 4th industrial revolution, research on solving urban problems using ICT technology is emerging. Representatively, research is being conducted mainly focusing on smart cities. 3D geo-spatial. Various case studies on smart cities are being conducted to solve urban problems, and in order to effectively implement smart cities, it is implemented on the basis of a digital twin interconnecting physical and virtual environments. To implement a digital twin, the concept of space is essential, and spatial information that composes the real world is also essential. Therefore, in order to implement the digital twin, this study conducted a study on the construction and modeling of 3D geo-spatial information based on the national spatial information establishment regulations and the international standard CityGML for buildings, water facilities, and transportation facilities in Jeonju. In Jeonju, the research area, the LOD was defined, and the possibility of digital twin based on geo-spatial information was determined through data collection, analysis, and construction for each detail. In this study, it is meaningful that a plan to construct geo-spatial information for the implementation of a digital twin is presented, and the result of the construction is modeled as an urban standard model. The results of study are expected to be used as reference for detailed construction plans and standard establishment by governments and local governments promoting smart city and digital twin construction in the future.