• Proceedings of the Korea Water Resources Association Conference
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• 2012.05a
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• pp.174-174
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• 2012

최근 농업용저수지의 경우 기상이변에 따른 수위조절을 위하여 다량의 수문을 일시에 개방하는 사례가 지역적으로 증가하고 있는 추세이다. 그에 따라 당초 목적인 농업용수를 위한 취수시설이 최근 홍수조절용으로 활용됨에 따른 취수시설 내 공동현상이 발생하고 있다. 이러한 공동현상으로 인해 수시설물의 안정성에 문제가 발생하고 그에 따른 2차 재해위험이 있을 수 있다. 따라서 본 연구에서는 공동현상 방지를 위해 취수시설 공기관 설계기준에 대하여 고찰하였다. 공동현상을 방지하고 홍수량을 적절하게 배제하기 위해서 유입되는 공기량산정식이 필요하다. 공기관 단면결정은 농업생산기반정비사업 설계기준(필댐)의 구조설계 부분에 정리되어 있지만 이는 이수측면에서 설계 및 시공이 진행됨에 따라서 취수에 대한 목적을 달성하기에는 어려움이 있다. 따라서 취수시설의 기능과 역할을 증대시키고자 취수시설 적정 공기관 설계를 분석하여 향후 신규, 개보수 및 현장 유지관리에 활용하기 위한 기초자료를 제시하였다. 이러한 공동현상 및 공기관 설계를 위하여 현장조사, 수치해석, 수리모형시험을 병행하여 문석하였다. 그 결과 취수탑의 형상변수와 수위에 대한 수치해석을 수행하여 변수가 소요공기량에 미치는 영향은 조절게이트 개폐율을 증가시킬수록 소요공기량이 증가하며, 약 80%의 개폐율에서 소요공기량이 최대가 되었다. 방수로 직경이 증가하면, 공기관 입구와 끝단의 압력차가 감소하여 소요공기량이 감소하고, 수위가 증가하면 소요공기량이 증가하는 것으로 분석되었다. 따라서 공동현상 방지를 위해 공기량 산정식은 취수터널에 연직수문이 설치되어 있는 6가지 흐름의 형태에 따라서 $/Q_w=0.04(F-1)^{0.85}$, $Q_a/Q_w=K(F-1)$, $Q_a/Q_w=0.014(F-1)^{1.4}$, $Q_a/Q_w=0.015(F-1)^{1.4}$의 관계식 중 적정한 것을 사용하여야 할 것으로 판단되며, 또한 공기관에 유입부의 허용부압은 수두로부터 1.0m이하로 하고, 공기관 내 풍속은 $45^m/s$를 기준으로 최대 $90^m/s$로 하여야 할 것으로 판단된다.

• 한국노년학
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• v.41 no.1
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• pp.85-105
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• 2021

The purpose of this research is to analyze care types in long-term care facilities with the view of Active Ageing by using Q-methodology. In-depth interviews were conducted to grasp various thoughts on care of long-term care facilities in three areas of WHO's active aging: health, safety, and participation. 35 people participated in the interview, including the elderly living in long-term care facilities, adult children of the elderly living in long-term care facilities, the elderly living in the community, service providers, and long-term care professionals. Of the 451 Q populations, 63 Q samples were extracted, and a total of 43 P samples were used for final data analysis. Data were analyzed using the QUANL program, and as a result, three factor structures (4 types) were found to be suitable and accounted for 30.15% of the total variance. Current care types in long-term care facilities were analysed into 4 types: protection-oriented care (type 1), participation-oriented care (type 2), medical-connected care (type 3), and human-centered care (type 4). Based on the results of this study, institutional and practical suggestions and implications were presented for the qualitative change of care in long-term care facilities.

• Journal of the Mineralogical Society of Korea
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• v.24 no.4
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• pp.301-312
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• 2011

The study on the atomic structure of iron-bearing silicate glasses has significant geological implications for both diverse igneous processes on Earth surface and ultra-low velocity zones at the core-mantle boundary. Here, we report experimental results on the effect of iron content on the atomic structure in iron-bearing alkali silicate glasses ($Na_2O-Fe_2O_3-SiO_2$ glasses, up to 16.07 wt% $Fe_2O_3$) using $^{29}Si$ and $^{17}O$ solid-state NMR spectroscopy. $^{29}Si$ spin-lattice ($T_1$) relaxation time for the glasses decreases with increasing iron content due to an enhanced interaction between nuclear spin and unpaired electron in iron. $^{29}Si$ MAS NMR spectra for the glasses show a decrease in signal intensity and an increase in peak width with increasing iron content. However, the heterogeneous peak broa-dening in $^{29}Si$ MAS NMR spectra suggests the heterogeneous distribution of $Q^n$ species around iron in iron-bearing silicate glasses. While nonbridging oxygen ($Na-O-Si$) and bridging oxygen (Si-O-Si) peaks are partially resolved in $^{17}O$ MAS NMR spectrum for iron-free silicate glass, it is difficult to distinguish the oxygen clusters in iron-bearing silicate glass. The Lorentzian peak shape for $^{29}Si$ and $^{17}O$ MAS NMR spectra may reflect life-time broadening due to spin-electron interaction. These results demonstrate that solid-state NMR can be an effective probe of the detailed structure in iron-bearing silicate glasses.

• Journal of Korean Library and Information Science Society
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• v.36 no.2
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• pp.197-220
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• 2005

This paper examined the structure of internet bookstore users' subjectivity by focusing on their beliefs, values and attitudes.0 methodology was utilized for the study. After constituting 36 Q sample and 28 P sample, data were collect from April 15, 2005 to April 22 2005. The analyses showed 3 types of subjectivity structures. The first one was 'the economic benefit-seeking type.' Those in this type were motivated to use internet bookstores to achieve economic benefits. They paid more attention to the Prices discounted than the web site contents provided by internet bookstores. This type was conspicuously found among college students. The second one was the 'information-seeking type.' People in this category made visits to internet bookstores in order to obtain new information or professional materials. This type was dominantly found among women. The third one was the 'convenience-seeking type.' Those in this type were concerned not only with the accessibility and convenience, but also with such practical issues as delivery, price, applicability, payment, and bonus. This type was conspicuously observed among white collar workers. These findings suggests that in order to make internet bookstores more attractive to users, it is demanded to understand various needs held by users and map out sophisticated marketing strategies on the basis of such a knowledge.

• Journal of the Korea Computer Graphics Society
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• v.8 no.2
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• pp.1-7
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• 2002

The fast extraction of the silhouettes of a model is very useful for many applications in computer graphics and animation. In this paper, we present an efficient algorithm to compute a sequence of perspective silhouettes for a polyhedral model from a moving viewpoint. The viewpoint is assumed to move along a trajectory q(t), which is a space curve of a time parameter t. Then, we can compute the time-intervals for each edge of the model to be contained in the silhouette by two major computations: (i) intersecting q(t) with two planes and (ii) a number of dot products. If q(t) is a curve of degree n, then there are at most of n + 1 time-intervals for an edge to be in a silhouette. For each time point $t_i$ we can extract silhouette edges by searching the intervals containing $t_i$ among the computed intervals. For the efficient search, we propose two kinds of data structures for storing the intervals: an interval tree and an array. Our algorithm can be easily extended to compute the parallel silhouettes with minor modifications.

• Korean journal of communication and information
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• v.43
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• pp.359-384
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• 2008

Nowadays, newspaper industry faces a crisis in terms of two aspects: First, in this multi-channel era, it has competed with the online journalism appearing in many digital media. Second, with the decrease of numbers of readers and political participation, the roles of newspaper has to be changed accordingly. The concept of civic journalism emerged as a solution in this context. The purpose of the study is to explore the factors in how journalists perceive the civic journalism. The Q-methodology was adapted to identify the factors composing of the belief, values, attitudes, ideas, and opinions toward the civic journalism. Total of 24 Q-sample (statements) were sorted by 27 P-sample (journalists) who were selected by their gender, years of service, and the like. The Quanl program finally produced 3 factors that were interpreted and named as follows: Factor I, the Complimentary Journalism, the civic journalism would fulfill the functions that traditional journalism has neglected. Factor II, the Alternative Journalism inducing the citizen's participation in the public areas. Factor III, the Functional Journalism, emphasizing dysfunction of the civic journalism.

• Korean Journal of Environment and Ecology
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• v.28 no.6
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• pp.725-740
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• 2014

To figure out the vegetation situation in the ridge of the Naknam-Jeongmaek, six intensive survey sites were selected considering environmental factors and human interferences, 132 quadrats (area $100m^2$) were installed to survey appearing species of trees and major environmental factors, and the characteristics of vegetation structures were analyzed. The surveyed plots were divided into six groups according to the analysis of classification by TWINSPAN; Quercus mongolica-Q. variabilis community, Pinus densiflora-Q. dentata community, Chamaecyparis obtusa community, Q. mongolica-P. densiflora community, P. densiflora-P. thunbergii community, P. koraiensis community, Rhododendron spp.-Lespedeza cyrtobotrya community. P. densiflora-Q. dentata community, Q. mongolica-P. densiflora community, and P. densiflora-P. thunbergii community are expected to be succeeded by deciduous oaks because the power of deciduous oaks is strong in their lower layer. C. obtusa community, P. densiflora community, and Rhododendron spp.-L.cyrtobotrya community are artificial forests that were artificially formed and are expected to be maintained in the current state for some time because the dominance value of planted species of trees is high. Most vegetations in Naknam-Jeongmaek were secondary forests or artificial forests formed for forest tree production and forestation for erosion control. In particular the top regions and hilly sections of the mountain were mostly dominated by deciduous oaks such as Q. mongolica, Q. variabilis showed some P. densiflora community competing with deciduous oaks. On the other hand, low sections and regions adjacent to the city showed severe artificial interference since exotic species such as P. thunbergiil, C. obtusa, P. koraiensis, and Rhododendron spp. were planted.

• Korean Journal of Environment and Ecology
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• v.38 no.3
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• pp.310-323
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• 2024

The purpose of this study was to understand the vegetation structure and ecological characteristic of Bulgapsan(Mt.) Provincial Park by setting up and surveying 64 plots(100m²). The analysis using the TWINSPAN and DCA techniques found seven community groups: Pinus densiflora-Quercus variabilis community, P. densiflora-P. rigida-Q. serrata community, Q. variabilis-Carpinus tschonoskii community, Q. aliena-Q. variabilis-Cornus controversa community, Q. aliena-Platycarya strobilacea community, Broad-leaved miced community and Q. variabilis community. The result of vegetation community structure analysis showed that P. densiflora community and deciduous Quercus spp. community were in competition, and succession to Quercus spp. community was expected. In the case of other broad-leaved forests, the current status is expected to be maintained. But continuous monitoring is required in areas where Neolitsea sericea and Cephalotaxus appear, which grow naturally in warm temperate forest and southern temperate vegetation zone. Species diversity by communities are confirmed to be highest at 2.6654 in the actively competitive P. densiflora-P. rigida-Q. serrata community, and the lowest in the Deciduous broad-leaved forests community at 1.2548. The results of the tree rings and annual growth analysis showed that dominant trees had an average age of more than 37~87 years. Among them, N. sericea designated as a natural monument was 48~56 years old.

• Journal of Advanced Navigation Technology
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• v.9 no.2
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• pp.147-155
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• 2005

In this paper, we propose that three uniform coplanar waveguides(CPWs), such as a conventional, finite grounded(FG), and grounded(G) CPWs, can be coupled with a $TE_{01{\delta}}$ mode dielectric resonator(DR) for a parallel resonant characteristic as a microstrip line coupled with the DR. Coupling characteristics have been investigated by placing the DR on a dielectric support above the CPWs and by moving the DR away from the center of a slot of the CPWs to the ground plane. FEM simulation(HFSS) results in terms of S-parameters agree well with measurement results. Finally, unloaded Q values of the DR coupled with the three uniform CPWs are compared with those of the DR coupled with a microstrip line. The comparison shows that the DR coupled with the three CPWs has higher unloaded Qs than that coupled with a microstrip line and that the GCPW case has the highest unloaded Qs.

• Journal of Korean Association for Spatial Structures
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• v.3 no.2 s.8
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• pp.85-90
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• 2003

If we use a third order approximation for the displacement function of beam element in finite element methods, finite element solutions of beams yield nodal displacement values matching to beam theory results to have no connection with the number increasing of elements of beams. It is assumed that, as the member displacement value at beam nodes are correct, the calculation procedure of beam element stiffness matrix have no numerical errors. A the member forces are calculated by the equations of $\frac{-M}{EI}=\frac{{d^2}{\omega}}{dx^2}\;and\;\frac{dM}{dx}=V$, the member forces at nodes of beams have errors in a moment and a shear magnitudes in the case of smaller number of element. The nodal displacement value of plate subject to the lateral load converge to the exact values according to the increase of the number of the element. So it is assumed that the procedures of plate element stiffness matrix calculations has a error in the fundamental assumptions. The beam methods for the high accuracy ratio solution Is also applied to the plate analysis. The method of reducing a error ratio of member forces and element stiffness matrix in the finite element methods is studied. Results of study were as follows. 1. The matrixes of EI[B] and [K] in the equations of M(x)=EI[B]{q} and M(x) = [K]{q}+{Q} of beams are same. 2. The equations of $\frac{-M}{EI}=\frac{{d^2}{\omega}}{dx^2}\;and\;\frac{dM}{dx}=V$ for the member forces have a error ratio in a finite element method of uniformly loaded structures, so equilibrium node loads {Q} must be substituted in the equation of member forces as the numerical examples of this paper revealed.