• Title/Summary/Keyword: local distance

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Proposal and Evaluation of Ultra High Speed Wireless Cell Backbone Networks (도시형 초고속 무선통신 셀백본망의 제안 및 평가)

  • Shin, Cheon-Woo;Park, Sung-Hyun
    • Proceedings of the Korea Electromagnetic Engineering Society Conference
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    • 2003.11a
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    • pp.243-248
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    • 2003
  • This paper is contents on that construct ultra high speed wireless communication cell backbone net of city using of wireless communication transceiver for millimeter wave band. A new type of 60GHz wave band wireless transceiver using NRD waveguide. This 60GHz transceiver has excellent signal's absorption characteristics of oxygen molecule than the other millimeter wave bands. We constructed service networks to cell interval within about 500m to 3Km laying stress on wireless backbone node using 60GHz transceivers, and did it so that city type wireless communication cell backbone networks of 155.52Mbps ATM(OC-3) may be possible. The possible use of wireless backbone networks technology in a rainy day and a clear day was evaluated at 1Km data link distance. We can measured bit error rate(BER). BER is $10^{-11}$ at 155.52Mbps ATM(OC-3) in a clear day and $10^{-6}$ in a heavy rain more than 35mm per time. Also, we constructed wireless cell backbone networks distance to use several 60GHz transceivers and investigated data transmission rate between main center and local center of long distance. In proposed wireless cell backbone networks, the data throughput was approximately 80Mbit/sec. Therefore, if use transceiver, it is possible that city type ultra high speed wireless communication cell backbone networks construction of 100Mbps, 155.52Mbps, 622Mbps, 1Gbps and 1.2Gbps degrees.

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Estimation of spatial autocorrelation variations of uncertain geotechnical properties for the frozen ground

  • Wang, Di;Wang, Tao;Xu, Daqing;Zhou, Guoqing
    • Geomechanics and Engineering
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    • v.22 no.4
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    • pp.339-348
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    • 2020
  • The uncertain geotechnical properties of frozen soil are important evidence for the design, operation and maintenance of the frozen ground. The complex geological, environmental and physical effects can lead to the spatial variations of the frozen soil, and the uncertain mechanical properties are the key factors for the uncertain analysis of frozen soil engineering. In this study, the elastic modulus, strength and Poisson ratio of warm frozen soil were measured, and the statistical characteristics under different temperature conditions are obtained. The autocorrelation distance (ACD) and autocorrelation function (ACF) of uncertain mechanical properties are estimated by random field (RF) method. The results show that the mean elastic modulus and mean strength decrease with the increase of temperature while the mean Poisson ratio increases with the increase of temperature. The average values of the ACD for the elastic modulus, strength and Poisson ratio are 0.64m, 0.53m and 0.48m, respectively. The standard deviation of the ACD for the elastic modulus, strength and Poisson ratio are 0.03m, 0.07m and 0.03m, respectively. The ACFs of elastic modulus, strength and Poisson ratio decrease with the increase of ratio of local average distance and scale of fluctuation. The ACF of uncertain mechanical properties is different when the temperature is different. This study can improve our understanding of the spatial autocorrelation variations of uncertain geotechnical properties and provide a basis and reference for the uncertain settlement analysis of frozen soil foundation.

The Adaptive Transmit Power Control Scheme of Mobile Host for Reduce Power Consumption in IEEE 802.11 Network (IEEE 802.11 네트워크에서 전력량 소모 감소를 위한 이동 호스트의 가변적인 송신 출력 제어 방법)

  • Cho, Sung-Il;Kim, Dong-Hoi
    • Journal of Digital Contents Society
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    • v.18 no.2
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    • pp.365-371
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    • 2017
  • IEEE 802.11 Wireless Local Area Network (WLAN) adopts Power Saving Mode(PSM) to save the power. Unlike existing PSM, this paper proposes a new scheme for the power saving of the Mobile Host(MH) when a MH performs the data transmission after the competition-based DCF(Distributed Coordination Function) and competition free-based PCF(Point Coordination Function). In this paper, The proposed scheme estimates the distance between the MH with the authority of data transmission and the Access Point(AP) and then adaptively controls the power of the MH considering the distance. Through the simulation result, we find that the proposed scheme consumes the smaller transmission power and has the similar success rate of packet transmission when it is compared to the existing scheme which uses the same power without the consideration of the distance.

Performance Analysis of Landing Point Designation Technique Based on Relative Distance to Hazard for Lunar Lander (달 착륙선의 위험 상대거리 기반 착륙지 선정기법 성능 분석)

  • Lee, Choong-Min;Park, Young-Bum;Park, Chan-Gook
    • Journal of the Korean Society for Aeronautical & Space Sciences
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    • v.44 no.1
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    • pp.12-22
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    • 2016
  • Lidar-based hazard avoidance landing system for lunar lander calculates hazard cost with respect to the desired local landing area in order to identify hazard and designate safe landing point where the cost is minimum basically using slope and roughness of the landing area. In this case, if the parameters are only considered, chosen landing target can be designated near hazard threatening the lander. In order to solve this problem and select optimal safe landing point, hazard cost based on relative distance to hazard should not be considered as well as cost based on terrain parameters. In this paper, the effect of hazard cost based on relative distance to hazard on safe landing performance was analyzed and it was confirmed that landing site designation with two relative distances to hazard results in the best safe landing performance by an experiment using three-dimensional depth camera.

Machine-printed Numeral Recognition using Weighted Template Matching with Chain Code Trimming (체인 코드 트리밍과 가중 원형 정합을 이용한 인쇄체 숫자 인식)

  • Jung, Min-Chul
    • Journal of Intelligence and Information Systems
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    • v.13 no.4
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    • pp.35-44
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    • 2007
  • This paper proposes a new method of weighted template matching for machine-printed numeral recognition. The proposed weighted template matching, which emphasizes the feature of a pattern using adaptive Hamming distance on local feature areas, improves the recognition rate while template matching processes an input image as one global feature. Template matching is vulnerable to random noises that generate ragged outlines of a pattern when it is binarized. This paper offers a method of chain code trimming in order to remove ragged outlines. The method corrects specific chain codes within the chain codes of the inner and the outer contour of a pattern. The experiment compares confusion matrices of both the template matching and the proposed weighted template matching with chain code trimming. The result shows that the proposed method improves fairly the recognition rate of the machine-printed numerals.

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Creative Cultural Localization Ways and IT Market of the EU to Converge the Creative Industries (창조융합시장을 위한 유럽 연합 (EU)의 시장과문화적 지역특화방안)

  • Seo, Dae-Sung
    • Journal of Distribution Science
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    • v.13 no.1
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    • pp.27-33
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    • 2015
  • Purpose - The ICT market in the EU is lagging behind that of the US; however, algorithm and software development within the EU have grown steadily, and they involve focusing on the creative cultural convergence conceptualized as part of Horizon 2020 and connecting neighboring markets in the EE and the Mediterranean region. It is essential to study the requirements to market the EU's creative ICT development in emerging industrial countries after examining its applicability in these countries. Research design, data, and methodology - This study deals with data pertaining to the EU's creative industry and competitive edge. The global cultural expansion of the EU facilitates a new concept involving not only low-cost IT products to enhance local cultural artifacts through R&D and the construction of efficient infrastructure services, but also information exchange with a realistic commercialization of the technology that can be applied for creative cultural localization. In the European industry, research on algorithms has been applied for the benefit of consumers. We investigated how the process is conducted in the EU. Results - Europe needs to adjust its economic structure to the local culture as part of IT distribution convergence. The convergence has been converted into a production algorithm with IT in the form of low-cost production. This is because there is an attempt to improve the quality of transport infrastructure, workforce availability, and the distribution of the distance to the local industries and consumers, using IT algorithms. Integrated into the manufacturing industry, based on the ICT infrastructure and solutions, smart localized regional clusters are formed with the help of grafting. Europe has own strategy to increase the number of hub-and-spoke cities. Europe is now becoming integrated, with an EPC system for regional cooperation rather than national competition in ICT technology. Europe has also been recognized in this study as changing the step-by-step paradigm for global competitiveness through new creative culture industries. Conclusions - As a result, there are several ways of converging with others through EU R&D intensity; therefore, the EU can be seen as successfully increasing marginal value, which is useful in developing a special industrial cluster or local cultural cities that create converged development by connecting people and objects with IT. In fact, when compared to the US, Europe has a strong culture and the car industries have a tendency to overshadow the IT industries with integration of services in IT distribution. Considering the rapid environmental changes, the convergence of IT services is likely to take place in Europe, similar to the pharmaceutical industry and the automotive industry. This requires a focus on human resources and automated systems management. The trend is to move away from low-wage industries, switched to key personnel centers of the local university-industry. EU emphasizes the creation of IT market demand in Europe involving local cultural convergence for marketing as the second step to strengthen the economic hub-and-spoke areas.

Study About the Capstone Design Education for the Growth of Local Design Industries - Based on the Exhibitional Project, 'Jeju Tamranun Idea' (지역디자인 산업발전을 위한 캡스톤 디자인교육 사례연구 - '제주 탐라는아이디어전'을 중심으로)

  • Kim, Jong-Min
    • The Journal of the Korea Contents Association
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    • v.21 no.6
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    • pp.653-662
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    • 2021
  • This is a thesis about the whole process of cooperative study for the project, 'Jeju Tamranun idea' which produced by Capstone Design Class in communication design Dept, Hongik University. The purpose of this thesis is to know the primary educational goal and essence of capstone design class and to find the enhancement plan for the local design industry. The exhibitional project, 'Jeju Tamranun idea' was operated three times by hongik university with the company based on Jeju from 2017 to 2019. After the research, There are three positive effects of this project which are the new social function of the discarded assignments, the improvement of educational standard through the autonomous competition, and the growth of students' social consciousness in the process of considering local industries. And there are several points to be reviewed for a better capstone design class with local design industries. It is necessary to utilize the untact system for solving distance issues. And also, absolute evaluations, giving equal reward, and copyright protection are needed. Lastly, the continuous development of the curriculum to improve local design industries is needed.

Effect of oxygen deficiency on electronic properties and local structure of amorphous tantalum oxide thin films

  • Denny, Yus Rama;Firmansyah, Teguh;Park, Chanae;Kang, Hee Jae;Yang, Dong-Seok;Heo, Sung;Chung, Jae Gwan;Lee, Jae Cheol
    • Proceedings of the Korean Vacuum Society Conference
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    • 2015.08a
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    • pp.122.1-122.1
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    • 2015
  • The dependence of electronic properties and local structure of tantalum oxide thin film on oxygen deficiency have been investigated by means of X-ray photoelectron spectroscopy (XPS), Reflection Electron Energy Loss Spectroscopy (REELS), and X-ray absorption spectroscopy (XAS). The XPS results showed that the oxygen flow rate change results in the appearance of features in the Ta 4f at the binding energies of 23.2 eV, 24.4 eV, 25.8, and 27.3 eV whose peaks are attributed to Ta1+, Ta2+, Ta3+, Ta4+, and Ta5+, respectively. The presence of nonstoichiometric state from tantalum oxide (TaOx) thin films could be generated by the oxygen vacancies. The REELS spectra suggested the decrease of band gap for tantalum oxide thin films with increasing oxygen deficiency. In addition, XAS spectra manifested both the increase of coordination number of the first Ta-O shell and a considerable reduction of the Ta-O bond distance with the decrease of oxygen deficiency.

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Heat/Mass Transfer Characteristics on Rib-roughened Surface for Impingement/Effusion Cooling System with Initial Crossflow (초기 횡방향 유동이 존재하는 충돌제트/유출냉각에서 요철이 설치된 유출면에서의 열/물질전달 특성)

  • Rhee, Dong-Ho;Nam, Yong-Woo;Cho, Hyung-Hee
    • Transactions of the Korean Society of Mechanical Engineers B
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    • v.28 no.3
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    • pp.338-348
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    • 2004
  • The present study is conducted to investigate the effect of rib arrangements on an impingement/effusion cooling system with initial crossflow. To simulate the impingement/effusion cooling system, two perforated plates are placed in parallel and staggered arrangements with a gap distance of 2 times of tile hole diameter. Initial crossflow passes between the injection and effusion plates, and the square ribs (3mm) are installed on the effusion plate. Both the injection and effusion hole diameters are 10mmand Reynolds number based on the hole diameter and hole-to-hole pitch are fixed to 10,000 and 6 times of the hole diameter, respectively. To investigate the effects of rib arrangements, various rib arrangements, such as 90$^{\circ}$transverse and 45$^{\circ}$angled rib arrangements, are used. Also, the effects of flow rate ratio of crossflow to impinging jets are investigated. With the initial crossflow, locally low transfer regions are formed because the wall jets are swept away, and level of heat transfer rate get decreased with increasing flow rate of crossflow. When the ribs are installed on the effusion plate, the local distributions of heat/mass transfer coefficients around the effusion holes are changed. The local heat/mass transfer around the stagnation regions and the effusion holes are affected by the rib positions, angle of attack and rib spacing. For low blowing ratio, the ribs have adverse effects on heat/mass transfer, but for higher blowing ratios, higher and more uniform heat transfer coefficient distributions are obtained than the case without ribs because the ribs prevent the wall jets from being swept away by the crossflow and increase local turbulence of the flow near the surface. Average heat transfer coefficients with rib turbulators are approximately 10% higher than that without ribs, and the higher values are obtained with small pitch of ribs. However, the attack angle of the rib has little influence on the average heat/mass transfer.

Domain Searching method using DCT-coefficient for Fractal Image Compression (Fractal 압축방법을 위한 DCT 계수를 사용한 도메인 탐색 방법)

  • Suh, Ki-Bum;Chong, Jong-Wha
    • Journal of the Institute of Electronics Engineers of Korea SP
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    • v.37 no.2
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    • pp.28-38
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    • 2000
  • This paper proposes a fractal compression method using the domain classification and local searching, which utilize DCT coefficient characteristic Generally, the fractal Image encoding method has a time consuming process to search a domain to be matched with range block In order to reduce computation complexity, the domain and range regions are respectively classified into 4 category by using the characteristics of DCT coefficients and each range region is encoded by a method suitable for the property of its category Since the bit amount of the compressed image depends on the number of range blocks, the matching of domain block and range block is induced on the large range block by using local search, so that compression ratio is increased by reducing the number of range block In the local search, the searching complexity is reduced by determining the direction and distance of searching using the characteristics of DCT coefficients The experimental results shows that the proposed algorithm have 1 dB higher PSNR and 0 806 higher compression ratio than previous algorithm.

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