• Title/Summary/Keyword: System boundary

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Microstructure and Electrical Properties of Pb[(Mg,Mn)Nb]O3-Pb(Zr,Ti)O3 Piezoelectric Ceramics

  • Kim, Jin-Ho;Kim, Jong-Hwa;Baik, Seung-Woo
    • Transactions on Electrical and Electronic Materials
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    • v.6 no.5
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    • pp.202-209
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    • 2005
  • Phase evolution, microstructure and the electrical properties such as $k_p$ and $Q_m$ of $Pb(Mg_{1/3}Nb_{2/3})O_3[PMN]-Pb(Mn_{1/3}Nb_{2/3})O3[PM'N]-PbZrO_3[PZ]-PbTiO_3[PT]$ quaternary system were investigated within the compositional ranges $0{\leq}y{\leq}0.125$, y+z=0.125, and $0.39{\leq}x{\leq}0.54$ of the formula $Pb_{0.97}Sr_{0.03}[Mg_{1/3}Nb_{2/3})_y\;(Mn_{1/3}Nb_{2/3})_z\;(Zr_{x}Ti_{1-x})_{1-(y+z)}]O_3$. In the case of increasing Mn/(Mg+Mn) ratio for a fixed Zr/Ti ratio of 47.5/52.5, phase relation remained unchanged but the grain size drastically decreased, and the electrical properties changed as following: both $k_P$ and $Q_m$ reached the peak values at $Mn/(Mg+Mn)\cong0.3l7$ and gradually decreased; $\varepsilon33^T$ showed a monotonic decrease; P-E hysteresis loop gradually changed to asymmetrical one, and $E_i$ increased in correspondence. With increasing Zr/Ti ratio for a fixed Mn/(Mg+Mn) ratio of 0.317, on the contrary, the cell parameter $(\alpha^2c)^{1/3}$ gradually increased, and tetragonal-rhombohedral morphotropic phase boundary appeared in the range of $51/49{\leq}Zr/Ti{\leq}54/46$. the meantime, the grain size substantially increased, and the electrical properties changed as following: $k_P$ and $\varepsilon33^T$ reached peak values at Zr/Ti=51/49 and 48/52, respectively, and then gradually decreased; change of $Q_m$ was adverse to $k_P$; both $E_C\;and\;E_i$ considerably decreased while $P_S$ moderately increased. For the system 0.125(PMN+PM'N)-0.875PZT studied, the composition Mn/(Mg+Mn)=0.3l7 and Zr/Ti=51/49 revealed some promising electrical properties for piezoelectric transformer application such as $k_P=0.58,\;Q_m\cong1000$, and $\varepsilon^T_{33}=970$, as well as dense and fine-grained microstructure.

The Environmental and Economic Effects of Green Area Loss on Urban Areas (도시지역에서의 녹지상실의 환경적 경제적 효과)

  • Kim, Jae-Ik;Yeo, Chang-Hwan
    • Journal of the Korean Association of Geographic Information Studies
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    • v.9 no.2
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    • pp.20-29
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    • 2006
  • Modeling urban climate caused by land use conversion is critical for human welfare and sustainable development, but has hampered because detailed information on urban characteristics is hard to obtain. With the advantage of satellite observations and the new statistical boundary system, this paper measures the economic and environmental effects of green area loss due to land use conversion in urban areas. To perform this purpose, data were collected from the various sources basic statistical unit data from the National Statistical Office, digital maps from the National Geographic Information Institute, satellite images, and field surveys when necessary. All data (maps and attributes) are built into the geographic information system (GIS). This paper also utilizes Landsat TM 5 imagery of Daegu city to derive vegetation index and to measure average surface temperature. The satellite data were examined using standard image processing software, ERDAS IMAGINE, and the results of the digital processing were presented with ARCVIEW(v.3.3). SAS package was used to perform statistical analyses. This study presents that there exists a strong relationship between land use change and climatic change as well as land price change. Based on results of the analysis, this paper suggests that planners should implement effective tools and policies of urban growth management to detect environmental quality and to make right decisions on policies concerning smart urban growth.

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An analysis of Characteristics of Heavy Rainfall Events over Yeongdong Region Associated with Tropopause Folding (대류권계면 접힘에 의한 영동지방 집중호우사례의 특성분석)

  • Lee, Hye-Young;Ko, Hye-Young;Kim, Kyung-Eak;Yoon, Ill-Hee
    • Journal of the Korean earth science society
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    • v.31 no.4
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    • pp.354-369
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    • 2010
  • The synoptic and kinematic characteristics of a heavy rainfall that occurred in Gangneung region on 22 to 24 October 2006 were investigated using weather maps, infrared images, AWS observation data and NCEP global final analyses data. The total amount of rainfall observed in the region for the period was 316.5 mm, and the instanteneous maximum wind speed was $63.7m\;s^{-1}$. According to the analysis of weather maps, before the starting of the heavy rainfall, an extratropical low pressure system was developed in the middle region of the Korean Peninsula, and an inverted trough was formed in the northern region of the peninsula. In addition, a jet stream on the upper charts of 300 hPa was located over the Yellow Sea and the southern boundary of the peninsula. A cutoff low in the cyclonic shear side of the upper jet streak, which was linked to an anomaly of isentropic potential vorticity, was developed over the northwestern part of the peninsula. And there are analyzed potential vorticity and wind, time-height cross section of potential vorticity, vertical air motion, maximums of the divergence and convergence and vertical distribution of potential temperature in Gangneung region. The analyzed results of the synoptic conditions and kinematic processes strongly suggest that the tropopause folding made a significant role of initializing the heavy rainfall.

Electoral Redistricting Problems of Non-autonomous Gu ('자치구가 아닌 구'의 선거구획정 문제)

  • Lee, Chungsup
    • Journal of the Korean Geographical Society
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    • v.49 no.3
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    • pp.371-389
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    • 2014
  • This study aims to analyze the redistricting problems in non-autonomous Gu. Although non-autonomous Gu is a just local administrative district, it has been regarded as an important and basic spatial unit in electoral redistricting. By the reform of Public Official Election Act in 2012, however, non-autonomous Gu is distinguished from local governments like Si, Gun and autonomous Gu, in boundary delimitation for the 19th National Assembly election, and some are divided into a part of another constituency. About these background, this study points out the following problems. First, in national scale, the reform of Act made the malapportionment in constituencies of non-autonomous Gus, comparing with those of local governments. Second, there was the discriminative application of Act in each non-autonomous Gu and it will make the malapportionment worse in next election, considering the reorganization of local administrative system. Finally, this study propose that it is necessary to select one from a variety of redistricting principles, especially between the prevention of gerrymandering, the representativeness of local government and the apportionment, prior to another amendment of redistricting system and the debate about political reform.

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Infringement status of overseas intellectual property right and required strategy (해외지식재산권 침해 현황과 그 대응방안에 관한 연구)

  • Yoon, Byung-Seop;Han, Jung-Hee
    • 한국벤처창업학회:학술대회논문집
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    • 2007.11a
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    • pp.15-43
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    • 2007
  • The object of this study is to present a strategy against technology protectionism of advanced countries focusing on international cooperation policy of KIPO and infringement of overseas intellectual property rights on the notion that a policy performed without a long-term plan will not lead to industrial growth in the long run. The number of dispute cases of intellectual property rights in Japan ranks first with 275 cases compared to that of other countries. Among the dispute case, the number of validation trial is 107 cases(38.9%), and correction trial is 83 cases(30.2%). The USA ranks second in dispute of intellectual property rights. Among the dispute of intellectual property rights in the USA, the number of validation trial is 66 cases(64.7%), and correction trial is 21 cases(20.6%). A strategy against technology protectionism of advanced countries is as follows. A strategy is required to cope with infringement of overseas intellectual property rights. Korean government has to strengthen the function of overseas intellectual property rights protection center, strengthen boundary restriction of infringement goods, promote international dispute study, train international dispute specialist, solve jurisdiction problem of patent court system, improve trial system, construct confidence as social capital etc. Enterprises have to maintain No Patent No Future policy, specialize on application and countermeasure against infringement dispute, participate for formation and standardization of Patent Pool, strive for specialization regarding technical transfer and license management.

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DGR-Tree : An Efficient Index Structure for POI Search in Ubiquitous Location Based Services (DGR-Tree : u-LBS에서 POI의 검색을 위한 효율적인 인덱스 구조)

  • Lee, Deuk-Woo;Kang, Hong-Koo;Lee, Ki-Young;Han, Ki-Joon
    • Journal of Korea Spatial Information System Society
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    • v.11 no.3
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    • pp.55-62
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    • 2009
  • Location based Services in the ubiquitous computing environment, namely u-LBS, use very large and skewed spatial objects that are closely related to locational information. It is especially essential to achieve fast search, which is looking for POI(Point of Interest) related to the location of users. This paper examines how to search large and skewed POI efficiently in the u-LBS environment. We propose the Dynamic-level Grid based R-Tree(DGR-Tree), which is an index for point data that can reduce the cost of stationary POI search. DGR-Tree uses both R-Tree as a primary index and Dynamic-level Grid as a secondary index. DGR-Tree is optimized to be suitable for point data and solves the overlapping problem among leaf nodes. Dynamic-level Grid of DGR-Tree is created dynamically according to the density of POI. Each cell in Dynamic-level Grid has a leaf node pointer for direct access with the leaf node of the primary index. Therefore, the index access performance is improved greatly by accessing the leaf node directly through Dynamic-level Grid. We also propose a K-Nearest Neighbor(KNN) algorithm for DGR-Tree, which utilizes Dynamic-level Grid for fast access to candidate cells. The KNN algorithm for DGR-Tree provides the mechanism, which can access directly to cells enclosing given query point and adjacent cells without tree traversal. The KNN algorithm minimizes sorting cost about candidate lists with minimum distance and provides NEB(Non Extensible Boundary), which need not consider the extension of candidate nodes for KNN search.

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Seismic safety assessment of eynel highway steel bridge using ambient vibration measurements

  • Altunisik, Ahmet Can;Bayraktar, Alemdar;Ozdemir, Hasan
    • Smart Structures and Systems
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    • v.10 no.2
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    • pp.131-154
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    • 2012
  • In this paper, it is aimed to determine the seismic behaviour of highway bridges by nondestructive testing using ambient vibration measurements. Eynel Highway Bridge which has arch type structural system with a total length of 216 m and located in the Ayvaclk county of Samsun, Turkey is selected as an application. The bridge connects the villages which are separated with Suat U$\breve{g}$urlu Dam Lake. A three dimensional finite element model is first established for a highway bridge using project drawings and an analytical modal analysis is then performed to generate natural frequencies and mode shapes in the three orthogonal directions. The ambient vibration measurements are carried out on the bridge deck under natural excitation such as traffic, human walking and wind loads using Operational Modal Analysis. Sensitive seismic accelerometers are used to collect signals obtained from the experimental tests. To obtain experimental dynamic characteristics, two output-only system identification techniques are employed namely, Enhanced Frequency Domain Decomposition technique in the frequency domain and Stochastic Subspace Identification technique in time domain. Analytical and experimental dynamic characteristic are compared with each other and finite element model of the bridge is updated by changing of boundary conditions to reduce the differences between the results. It is demonstrated that the ambient vibration measurements are enough to identify the most significant modes of highway bridges. After finite element model updating, maximum differences between the natural frequencies are reduced averagely from 23% to 3%. The updated finite element model reflects the dynamic characteristics of the bridge better, and it can be used to predict the dynamic response under complex external forces. It is also helpful for further damage identification and health condition monitoring. Analytical model of the bridge before and after model updating is analyzed using 1992 Erzincan earthquake record to determine the seismic behaviour. It can be seen from the analysis results that displacements increase by the height of bridge columns and along to middle point of the deck and main arches. Bending moments have an increasing trend along to first and last 50 m and have a decreasing trend long to the middle of the main arches.

A study on the standardization of advertising through the appeal means change (소구형태변화를 통한 광고의 표준화 수준에 관한 연구)

  • 김기수
    • Journal of Korean Society of Industrial and Systems Engineering
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    • v.17 no.32
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    • pp.255-266
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    • 1994
  • This study does present things to suggest to foreign multinational corporation or domestic corporation through the empirical study on the standardization level. If we summary this study, it is as follows. In chapter I, we did institute the problems and explain the objects and methods and system of the study. In chapter II, we did explain the universality of the culture and international advertisement. Next, we did explain the background of doing specialization strategy and standardization strategy. Also we did study the previous study about the arguements for and against these. Lsat we did institute the hypothesises as follows. - Hypothesis 1 $H_0$ : The use of westerner appeal means has been increased than 11 years before and is able to increase continuously. - Hypothesis 2 $H_0$ : The use of westerner model and knowned has been increased than 11 years before and is able to increase continuously. - Hypothesis 3 $H_0$ : The use of the English language has been increased than 11 years before and is able to increase continuously. - Hypothesis 4 $H_0$ : The use of the west short piece and background has been increased than 11 years before and is able to increase continuously. In chapter III, we did refer to the method of this study. First, we did adjust the measure of standardization index, and we did work coding it, such after the two coder did check the freguency of the appeal meanstype about the advertisement of four daily report. Then we did select eight production as high involvement production and seven production as low involvement. We did test the coder's trust degree on the such sample to be selected through the 't-test' of the SAS statistic program and regression analysis through the spss/$pc^+$ statistic program to approve the this study's hypothesises. In chapter IV, we did analysis the results of the empirical study on the high or low involvement productions. First, the results of t-test to approve the coder's trust degree is that it is same statistically attentionly the distribution of the sample between coder at 10% attention level. Next, the results of the regression analysis on eight hypothesises are as fellows. In case of high involvement production we are able to speak that the use of the English language appeal among the eight appeals is only standardized. And incase of low involvement production, we are able to speak that the use of the hard-sell appeal among the eight appeds is only standardized. Therefore we did conclude that the standardization level of Korea newspaper advertisement is low. Also this suggests that it will do plan and do the specialzation strategy or localization strategy foreign multinational corporation or domestic corporation in Korea newspaper advertisement. In chapter V, we do present the boundary of this study and new study methods.

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Regional Realtime Ocean Tide and Storm-surge Simulation for the South China Sea (남중국해 지역 실시간 해양 조석 및 폭풍해일 시뮬레이션)

  • Kim, Kyeong Ok;Choi, Byung Ho;Lee, Han Soo;Yuk, Jin-Hee
    • Journal of Korean Society of Coastal and Ocean Engineers
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    • v.30 no.2
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    • pp.69-83
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    • 2018
  • The South China Sea (SCS) is a typical marginal sea characterized with the deep basin, shelf break, shallow shelf, many straits, and complex bathymetry. This study investigated the tidal characteristics and propagation, and reproduced typhoon-induced storm surge in this region using the regional real-time tide-surge model, which was based on the unstructured grid, resolving in detail the region of interest and forced by tide at the open boundary and by wind and air pressure at the surface. Typhoon Haiyan, which occurred in 2013 and caused great damage in the Philippines, was chosen as a case study to simulate typhoon's impact. Amplitudes and phases of four major constituents were reproduced reasonably in general, and the tidal distributions of four constituents were similar to the previous studies. The modelled tide seemed to be within the acceptable levels, considering it was difficult to reproduce the tide in this region based on the previous studies. The free oscillation experiment results described well the feature of tide that the diurnal tide is prevailing in the SCS. The tidal residual current and total energy dissipation were discussed to understand the tidal and sedimentary environments. The storm-surge caused by typhoon Haiyan was reasonably simulated using this modeling system. This study established the regional real-time barotropic tide/water level prediction system for the South China Sea including the seas around the Philippines through the validation of the model and the understanding of tidal characteristics.

Status and Prospect of Unmanned, Global Ocean Observations Network (글로벌 무인해양관측 네트워크 현황과 전망)

  • Nam, Sunghyun;Kim, Yun-Bae;Park, Jong Jin;Chang, Kyung-Il
    • The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
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    • v.19 no.3
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    • pp.202-214
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    • 2014
  • We introduce status and prospect of increasingly utilizing, unmanned, global ocean observing systems, and the global network to integrate, coordinate, and manage the systems. Platforms of the ocean observing system are diversified in order to resolve/monitor the variability occurring at multiple scales in both three-dimensional space and time. Here purpose, development history, and current status of the systems in two kinds - mobile (surface drifter, subsurface float, underwater glider) and fixed platforms (surface and subsurface moorings, bottom mounts), are examined and the increased future uses to produce synergies are envisioned. Simultaneous use of various mobile and fixed platforms is suggested to more effectively design the observing system, with an example of the NSF-funded OOI (Ocean Observations Initiative) program. Efforts are suggested 1) to fill the data gap existing in the deep sea and the Southern Ocean, and toward 2) new global network for oceanic boundary currents, 3) new technologies for existing and new sensors including biogeochemical, acoustic, and optical sensors, 3) data standardization, and 4) sensor calibration and data quality control.