• Title/Summary/Keyword: 공간적 확산

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A Propose on the Propagation Prediction Model for Service in the Sea of CDMA Mobile Communication (CDMA 이동통신의 해상 서비스를 위한 전파예측모델 제안)

  • Kim, Young-Gon;Park, Chang-Kyun
    • Journal of the Institute of Electronics Engineers of Korea CI
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    • v.38 no.6
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    • pp.106-112
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    • 2001
  • Unfortunately, the area without economical efficiency, especially the far distance sea, is much lower than that of a urban area-built-up area. It should be promoted the equivalent level to a urban area in the light of future-oriented universal service. Actually, Because propagation environment of mobile communication in the sea is greatly different from that for inland focused on built-up area, a propagation prediction model in the sea should be distinguished from inland-based one. Accordingly, the purpose of this study is to suggest the propagation prediction model for the sea service as a method to minimize unnecessary facilities investment and maintenance caused by additional or new building of a base station. If mobile phone service for far distance sea is provided by expanding limited communication zone of narrow band CDMA mobile communication whose spread band FA is 1.2288MHz. Suggested propagation prediction model includes five parameters to minimize facilities investment of a base station and maximize channel capacity: equivalent line of sight, chip delay by PN code, antenna altitude, power of base station and gain of antennas. Finally, suggested propagation prediction model is simulated and, the results are examined for its utility by comparing with loss of free space.

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Making a Civil War Surrounding History in Cyber Space Focused on 5·18 Discourses in Ilbe Storehouse (사이버 공간에서의 역사의 내전(內戰)화 '일간베스트저장소'의 5·18 언설을 중심으로)

  • Jung, Soo-Young;Lee, Youngjoo
    • Korean journal of communication and information
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    • v.71
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    • pp.116-154
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    • 2015
  • Officially given a historical signifier as Gwangju Democratic Movement since 1987, far-right and conservative group have restated that $5{\cdot}18$ is a rebellion and a riot that was committed by rebellious elements who obeyed North Korea's command or who were connected with North Korea. As those who had been responsible for the rebellion, revolt and riot were rewarded, far-right and conservatives' collective narrative that a country was born where the pro-North Korea left became dominated aroused extreme hostility towards $5{\cdot}18$. Far-right and conservatives involved in many different fields such as political party, university, press and media and civil group carry out incendiary discourse politics with intention to reestablish history and memory of $5{\cdot}18$ in their own story. Many people at online sites such as Ilbe Storehouse who are considered 'young right wing' is a main route to spread the far-right groups' remarks on $5{\cdot}18$. Ilbe is a main channel to reconstitute and reproduce the far-right conservatives' remarks and information on $5{\cdot}18$. Ilbe is one of main area where remarks of disparagement and ridicule, hostility and hatred on $5{\cdot}18$ unfurl. This study collects $5{\cdot}18$-related remarks and stories unfolded at Ilbe and examines how these remarks and stories make significance as to $5{\cdot}18$ and how information resources which remarks are dependent upon are connected each other. In this process, this study intends to find implications of incendiary politics that echoed of remarks on $5{\cdot}18$ have which at the online site Ilbe and by the far-right conservatives.

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Integration and Decision Algorithm for Location-Based Road Hazardous Data Collected by Probe Vehicles (프로브 수집 위치기반 도로위험정보 통합 및 판단 알고리즘)

  • Chae, Chandle;Sim, HyeonJeong;Lee, Jonghoon
    • The Journal of The Korea Institute of Intelligent Transport Systems
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    • v.17 no.6
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    • pp.173-184
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    • 2018
  • As the portable traffic information collection system using probe vehicles spreads, it is becoming possible to collect road hazard information such as portholes, falling objects, and road surface freezing using in-vehicle sensors in addition to existing traffic information. In this study, we developed a integration and decision algorithm that integrates time and space in real time when multiple probe vehicles detect events such as road hazard information based on GPS coordinates. The core function of the algorithm is to determine whether the road hazard information generated at a specific point is the same point from the result of detecting multiple GPS probes with different GPS coordinates, Generating the data, (3) continuously determining whether the generated event data is valid, and (4) ending the event when the road hazard situation ends. For this purpose, the road risk information collected by the probe vehicle was processed in real time to achieve the conditional probability, and the validity of the event was verified by continuously updating the road risk information collected by the probe vehicle. It is considered that the developed hybrid processing algorithm can be applied to probe-based traffic information collection and event information processing such as C-ITS and autonomous driving car in the future.

The Development of VR based Application for Realistic Disaster Prevention Training (현실감 있는 재난재해 예방 교육을 위한 VR 기반 앱 개발)

  • Kim, Taehoon;Youn, Junhee
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.19 no.12
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    • pp.287-293
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    • 2018
  • The Korean peninsula has been known as an area that is free of volcanic disasters. However, recent observations and research results of volcanoes in Far East Asia, including Baedu Mountain and Japanese volcanoes, show that the Korean peninsula is no longer a safe area from volcanic disasters. Since 2012, the Korean government has been developing an IT-based construction technology, VDRS (Volcanic Disaster Response System), for effective volcanic disaster response system. The main users of VDRS are public officers in central or local governments. However, most of them have little experience and knowledge about volcanic disasters. Therefore, it is essential to develop education contents and implement training on volcanic disaster response for effective response in a real disaster situation. In this paper, we deal with the development of a mobile application based on virtual reality (VR) for realistic volcanic disaster response training. The objectives of training are the delivery of knowledge and experience for volcanic disasters. First, VR contents were generated based on spatial information. A 3D model was constructed based on a Digital Elevation Model (DEM), and visualization models for meterological effects and various volcanic disaster diffusion effects were implemented for the VR contents. Second, the mobile application for the volcanic disaster response training was implemented. A 12-step story board is proposed for volcanic disaster experience. The application was developed with the Unity3D engine based on the proposed story board to deliver knowledge of various volcanic disasters (volcanic ash, pyroclastic flows, volcanic mudflow etc.). The results of this paper will be used for volcanic disaster response and prevention training and for more realistic training linked with augmented reality technology in the future.

A Numerical Study on Ventilation Characteristics of Factors Affecting Leakages in Hydrogen Ventilation (누출 수소 환기에 영향을 미치는 요인별 환기 특성에 관한 수치해석적 연구)

  • Lee, Chang-Yong;Cho, Dae-Hwan
    • Journal of the Korean Society of Marine Environment & Safety
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    • v.28 no.4
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    • pp.610-619
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    • 2022
  • Hydrogen is emerging as an alternative fuel for eco-friendly ships because it reacts with oxygen to produce electrical energy and only water as a by-product. However, unlike regular fossil fuels, hydrogen has a material with a high risk of explosion due to its low ignition point and high flammability range. In order to safely use hydrogen in ships, it is an essential task to study the flow characteristics of hydrogen leakage and diffusion need to be studied. In this study, a numerical analysis was performed on the effect of leakage, ventilation, etc. on ventilation performance when hydrogen leaks in an enclosed space such as inside a ship. ANSYS CFX ver 18.1, a commercial CFD software, was used for numerical analysis. The leakage rate was changed to 1 q, 2 q, and 3 q at 1 q = 1 g/s, the ventilation rate was changed to 1 Q, 2 Q and 3 Q at 1 Q = 0.91 m/s, and the ventilation method was changed to type I, type II, type III to analyze the ventilation performance was analyzed. As the amount of leakage increased from 1 q to 3 q, the HMF in the storage room was about 2.4 to 3.0 times higher. Furthermore, the amount of ventilation to reduce the risk of explosion should be at least 2 Q, and it was established that type III was the most suitable method for the formation of negative pressure inside the hydrogen tank storage room.

Gas Injection Experiment to Investigate Gas Migration in Saturated Compacted Bentonite (포화 압축 벤토나이트 내 기체 이동 현상 관측을 위한 기체 주입 시험)

  • Jung-Tae Kim;Changsoo Lee;Minhyeong Lee;Jin-Seop Kim;Sinhang Kang
    • Tunnel and Underground Space
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    • v.34 no.2
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    • pp.89-103
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    • 2024
  • In the disposal environment, gases can be generated at the interface between canister and buffer due to various factors such as anaerobic corrosion, radiolysis, and microbial degradation. If the gas generation rate exceeds the diffusion rate, the gas within the buffer may compress, resulting in physical damage to the buffer due to the increased pore pressure. In particular, the rapid movement of gases, known as gas breakthroughs, through the dilatancy pathway formed during this process may lead to releasing radionuclide. Therefore, understanding these gas generation and movement mechanism is essential for the safety assessment of the disposal systems. In this study, an experimental apparatus for investigating gas migration within buffer was constructed based on a literature review. Subsequently, a gas injection experiment was conducted on a compacted bentonite block made of Bentonile WRK (Clariant Ltd.) powder. The results clearly demonstrated a sharp increase in stress and pressure typically observed at the onset of gas breakthrough within the buffer. Additionally, the range of stresses induced by the swelling phenomenon of the buffer, was 4.7 to 9.1 MPa. The apparent gas entry pressure was determined to be approximately 7.8 MPa. The equipment established in this study is expected to be utilized for various experiments aimed at building a database on the initial properties of buffer and the conditions during gas injection, contributing to understanding the gas migration phenomena.

The Role of New Information and Communication Technologies in the Internationalization of Firms: A Case Study of Haier (기업의 국제화와 신 정보통신기술의 역할: 중국 Haier 기업을 사례로)

  • Liu, Shuguang;Liu, Weidong
    • Journal of the Korean Geographical Society
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    • v.38 no.3
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    • pp.400-412
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    • 2003
  • It is now widely recognized that new Information and Communication Technologies (ICTs) have been changing the way tv which firms conduct their businesses. Examples are the application of enterprise resources planning (ERP) and business process reengineering (BPR) to increase the efficiency of internal resources management, adoption of Business-to-Business e-commerce (B2B e-com) to integrate supply chain, and invention of new marketing channels such as Business-to-Customer (B2C) e-com. These new ways of conducting businesses are believed to help firms to reduce transaction costs and increase productivity. As a result, new ICTs have played an important role in recent growth of many small firms into multi-functional and multi-product corporations and in their spatial expansion towards internationalization as well. This paper takes Haier in China as a case to study the role of new ICTs in the growth of firms and reveal how the new technologies have facilitated the expansion of Haier into a transnational corporation (TNC) by examining the internationalization process of the firm in relation to its adoption of new ICTs in the period from 1990 to 2002. The study reveals that the adoption of new Ins has helped Haier to integrate its functional units located in dozens of places across the world, which is essential to the internationalization of a firm, and to link closely together its worldwide suppliers and customers to achieve just-in-time (JIT) production and delivery. As such, the authors of the paper argue that, without the facilitation of new ICTS, Haier could not have developed into a TNC in less than ten years.It is now widely recognized that new Information and Communication Technologies (ICTs) have been changing the way tv which firms conduct their businesses. Examples are the application of enterprise resources planning (ERP) and business process reengineering (BPR) to increase the efficiency of internal resources management, adoption of Business-to-Business e-commerce (B2B e-com) to integrate supply chain, and invention of new marketing channels such as Business-to-Customer (B2C) e-com. These new ways of conducting businesses are believed to help firms to reduce transaction costs and increase productivity. As a result, new ICTs have played an important role in recent growth of many small firms into multi-functional and multi-product corporations and in their spatial expansion towards internationalization as well. This paper takes Haier in China as a case to study the role of new ICTs in the growth of firms and reveal how the new technologies have facilitated the expansion of Haier into a transnational corporation (TNC) by examining the internationalization process of the firm in relation to its adoption of new ICTs in the period from 1990 to 2002. The study reveals that the adoption of new Ins has helped Haier to integrate its functional units located in dozens of places across the world, which is essential to the internationalization of a firm, and to link closely together its worldwide suppliers and customers to achieve just-in-time (JIT) production and delivery. As such, the authors of the paper argue that, without the facilitation of new ICTS, Haier could not have developed into a TNC in less than ten years.

A Study on the Art Education Program Based on Cultural Diversity: Focused on the Case of National Museum of Modern and Contemporary Art, Korea (서울어젠다 기반 문화다양성 미술관교육 프로그램 분석 및 방향 - 국립현대미술관 사례를 중심으로 -)

Water-absorption characteristics and cooked rice texture of milled rice (쌀 수침 중 벼 품종별 수분흡수 특성 및 취반미 물성)

  • Choi, Induck;Oh, You-Geun;Kwak, Jieun;Chun, Areum;Kim, Mi-Jung;Hyun, WoongJo
    • Korean Journal of Food Science and Technology
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    • v.53 no.4
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    • pp.486-494
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    • 2021
  • A rice (Oryza sativa L.) cultivar of the SPP (stakeholder participatory program) and ordinary rice were characterized based on water-absorption properties and cooked rice texture. During rice soaking, the rice grain transformed from transparent to opaque (white), indicating that water molecules diffused into the rice grain during soaking. In addition, cracks in the internal structure of soaked rice gradually increased with an increase in soaking time. Water absorption increased rapidly up to 20 min, but no increment was observed after 30 min of soaking. At this point, the entire areas of the soaked rice grain turned white, indicating that water absorption had reached saturation. SPP rice showed lower hardness and higher stickiness in its cooked form than ordinary rice, suggesting that SPP rice could be a more preferable choice than ordinary rice. Furthermore, cooked SPP rice was more edible in terms of hardness and stickiness after being kept warm for 12 h than ordinary rice. These results indicated that cooked SPP rice exhibited slow retrogradation and improved taste.

Characteristics of Stream and Soil Contamination from the Tailing Disposal and Waste Rocks at the Abandoned Uljin Mine (울진 폐광산의 매립광미와 폐광석에 의한 주변 토양 및 수계의 오염특성)

  • Lee, In-Gyeong;Choi, Sang-Hoon
    • Economic and Environmental Geology
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    • v.41 no.1
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    • pp.63-79
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    • 2008
  • Physicochemical characteristics of stream water, leachate, mine water and groundwater were investigated to estimate the influences of the tailing and waste rock from the abandoned Uljin mine area. Total extraction analysis and mineralogical studies were carried out to understand sulfide weathering and to determine the distributions of trace elements in the soil affected by mine waste (tailing, waste rock and leachate). The pH and EC value of the leachate from the tailing disposal ranged 2.9-6.0, $99{\sim}3,990{\mu}S/cm$, respectively, and the concentrations of dissolved major (up to 492 mg/l Ca; 83.8 mg/l Mg; 45.2 mg/l Na; 44.7 mg/l K, 50.8 mg/l Si) and trace elements (up to $826,060{\mu}g/l$ Fe; $131,230{\mu}g/l$ Mn; $333,600{\mu}g/l$ Al; $61,340{\mu}g/l$ Zn; $2,530{\mu}g/l$ Cu; $573{\mu}g/l$ Cd; $476{\mu}g/l$ Pb) were relatively high. The stream water showed the variation of dissolved metal concentrations in seasonally and spatially. The dissolved metal contents of the stream water increased by influx the leachate from the tailing disposal, but these of the down stream have been considerably decreased by mixing of dilute tributaries. The dissolved metal concentrations of the stream water at dry season (as February) were lower than these at rainy season (as May and July). These represent that the amounts of the leachate varied with season. However, stream water could not be effectively diluted by confluence with uncontaminated tributaries, because the flux of tributaries and streams reduced at dry season. Thus attenuations by dilution had been dominantly happened in rainy seasons. The order of accumulations of trace element in soils compared with background values revealed Mn>Fe>Pb>Cu>Zn. Sulfide minerals were mainly pyrrhotite, sphalerite and galena and chalcopyrite. Pyrrhotite was rapidly weathered along the edge and fractures, and results in the formation of Fe-(oxy)hydroxides, which absorbed a little amount of Zn.