• Title/Summary/Keyword: Path length

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A Study on the Relationship between Community Cohesion and Community Participation for the Foundation of Community Welfare Planning (지역사회복지계획의 기반조성을 위한 지역사회응집력과 지역사회참여의 관계에 관한 연구)

  • Kang, Dae-Sun;Ryu, Ki-Hyung
    • Korean Journal of Social Welfare
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    • v.59 no.1
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    • pp.27-53
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    • 2007
  • Until now, the strategies for increasing community participation has been focusing on the administrative legal institutionalization, but these have not brought substantive effects. So, the need of strategies utilizing the community culture which was formed by the residents and community has been issued on recently. The purpose of this study is to explore the strategies utilizing the community culture. So, it was identified the socio-demographic variables affected the community cohesion (community social networks, community solidarity, place-attachment), that is called community spirit and culture. And through path analysis, it was analyzed the relationship among residents' socio-demographic background, community cohesion, and community participation. The findings are as follows. : the community cohesion's three elements altogether affected positively to the community participation. When regarding the residents characteristics, the strategies for increasing the participation relating to community solidarity was most relevant. the socio-demographics affecting to community solidarity are gender, age, the beneficiary, religion, job type, household income, the length of residence. the women was low at level of participation. The most important variables affecting the community cohesion are the age, the residence duration. Based on these results, the relevant strategies or approaches for increasing community participation are as follows. : using and sharing of the aged's community knowledge, making the long term living and final settlement of community residents, increasing and creating the income for the low-income residents, increasing of religious organization and its members' responsibility to community, and the purposeful extension and relevancy of women's participation. Ultimately, this study is to contribute to fomulate the residents- cultural asset driven's community welfare planning.

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Perspectives on the Landscape Characteristics and Management Scheme of Sacred Dangsan Forest in Singi-ri, Namwon-si as an Agricultural Heritage (농업유산으로서 남원시 신기리 당산숲의 경관 특성 및 관리방안 고찰)

  • Choi, Jai-Ung;Kim, Dong-Yeob;Yoon, Soon-Duck;Kwak, Min-Jeong
    • Journal of the Korean Institute of Traditional Landscape Architecture
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    • v.34 no.3
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    • pp.115-123
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    • 2016
  • In this study, the landscape characteristics of the sacred Dangsan forests at Singi-ri, Namwon-si were investigated as an agricultural heritage, and the management scheme for revitalization of the village was introduced. FAO established the term of 'GIAHS' (Globally Important Agricultural Heritage Systems) for conservation of each country's farmland, unique agricultural landscape, and cultural diversity. The Ministry of Agriculture, Food and Rural Affairs of Korea evaluates that the Agricultural Heritage is a new means and potential for rural development. Dangsan forest, a traditional village forests of rural Korea is a representative 'agricultural heritage' with a history of more than several hundred years of Dangsan ritual. The Dangsan forests were closely linked with paddy fields. This forest was composed of two Dangsan forests, and one Bibo forest. Especially, the Dangsan forest 2 was established on the mounding with 395m in length and 15m in width. Although, most of Dangsan forests do not have accurate records about forest establishment, this forest has retained a stone monument that illustrated the history of the forest. These aspects of Singi-ri's Dangsan forest indicated clear difference and characteristics compared to other ones. This Dangsan forest has been left alone from the public attention. The Dangsan forest at Singi-ri need to be recognized for their valuable landscape characteristics. By linking the Dangsan forest with 'Jirisan trail', the trail path will lead people to the agricultural heritage at Singi-ri. Enhancing the management scheme will contribute to revitalize the village.

Trajectory Clustering in Road Network Environment (도로 네트워크 환경을 위한 궤적 클러스터링)

  • Bak, Ji-Haeng;Won, Jung-Im;Kim, Sang-Wook
    • The KIPS Transactions:PartD
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    • v.16D no.3
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    • pp.317-326
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    • 2009
  • Recently, there have been many research efforts proposed on trajectory information. Most of them mainly focus their attention on those objects moving in Euclidean space. Many real-world applications such as telematics, however, deal with objects that move only over road networks, which are highly restricted for movement. Thus, the existing methods targeting Euclidean space cannot be directly applied to the road network space. This paper proposes a new clustering scheme for a large volume of trajectory information of objects moving over road networks. To the end, we first define a trajectory on a road network as a sequence of road segments a moving object has passed by. Next, we propose a similarity measurement scheme that judges the degree of similarity by considering the total length of matched road segments. Based on such similarity measurement, we propose a new clustering algorithm for trajectories by modifying and adjusting the FastMap and hierarchical clustering schemes. To evaluate the performance of the proposed clustering scheme, we also develop a trajectory generator considering the observation that most objects tend to move from the starting point to the destination point along their shortest path, and perform a variety of experiments using the trajectories thus generated. The performance result shows that our scheme has the accuracy of over 95% in comparison with that judged by human beings.

CuO Nanograss as a Substrate for Surface Enhanced Raman Spectroscopy

  • Lee, Jun-Young;Park, Jiyun;Kim, Jeong-Hyun;Yeo, Jong-Souk
    • Proceedings of the Korean Vacuum Society Conference
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    • 2013.08a
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    • pp.249-249
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    • 2013
  • Surface-enhanced Raman spectroscopy (SERS) is a sensitive approach to detect and to identify a variety of molecules. To enhance the Raman signal, optimization of the gap between nanostructures is quite important. One-dimensional materials such as nanowires, nanotubes, and nanograsses have great potential to be used in SERS due to their unique sizes and shape dependent characteristics. In this study we investigate a simple way to fabricate SERS substrates based on randomly grown copper oxide (CuO) nanowires. CuO nanograss is fabricated on pre-cleaned Cu foils. Cu oxidized in an ammonium ambient solution of 2.5 M NaOH and 0.1 M $(NH_4)_2S_2O_8$ at $4^{\circ}C$ for 10, 30, and 60 minutes. Then, Cu(OH)2 nanostructures are formed and dried at $180^{\circ}C$ for 2 h. With the drying process, the Cu(OH)2 nanostructure is transformed to CuO nanograss by dehydration reaction. CuO nanograss are grown randomly on Cu foil with the average length of 10 ${\mu}m$ and the average diameter of a 100 nm. CuO nanograsses are covered by Ag with various thicknesses from 10 to 30 nm using a thermal evaporator. Then, we immerse uncoated and Ag coated CuO nanowire samples of various oxidation times in a 0.001M methanol-based 4-mercaptopyridine (4-Mpy) in order to evaluate SERS enhancement. Raman shift and SERS enhancement are measured using a Raman spectrometer (Horiba, LabRAM ARAMIS Spectrometer) with the laser wavelength of 532 nm. Raman scattering is believed to be enhanced by the interaction between CuO nanograss and Ag island film. The gaps between Ag covered CuO nanograsses are diverse from <10 nm at the bottom to ~200 nm at the top of nanograsses. SERS signal are improved where the gaps are minimized to near 10s of nanometers. There are many spots that provide sufficiently narrow gap between the structures on randomly grown CuO nanograss surface. Then we may find optimal enhancement of Raman signal using the mapping data of average results. Fabrication of CuO nanograss based on a solution method is relatively simple and fast so this result can potentially provide a path toward cost effective fabrication of SERS substrate for sensing applications.

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Optical Simulation Study of the Improvement of Color-rendering Characteristics of White Light-emitting Diodes by Using Red Quantum-dot Films (적색 양자점 필름을 이용한 백색 발광 다이오드의 연색성 개선에 대한 광학 시뮬레이션 연구)

  • Lee, Gi Jung;Hong, Seung Chan;Lee, Jung-Gyun;Ko, Jae-Hyeon
    • Korean Journal of Optics and Photonics
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    • v.32 no.4
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    • pp.163-171
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    • 2021
  • Conventional white light-emitting diodes (LEDs) for lighting applications consist of blue LEDs and yellow phosphors, the spectrum of which lacks deep red. To improve the color-rendering characteristics of white LEDs, a red quantum-dot film was applied to the diffuser plate of LED lighting. The mean free paths of the quantum dots and the concentration of the TiO2 particles in the diffuser plate were adjusted to optimize the optical structure of the lighting. The color-rendering index (CRI) was greater than 90 for most conditions, which demonstrates that adoption of the red quantum-dot film is an effective way for improving the color-rendering properties of conventional white LEDs. The angular dispersion of color coordinates could be removed by utilizing the optical cavity formed between the diffuser plate and the reflector on the bottom of the lighting, where multiple passages of the light through the quantum-dot film reduced the differences in optical path length depending on the viewing angle.

Analysis of bifurcation characteristics for the Seolmacheon experimental catchment based on variable scale of source basin (수원 유역의 변동성 규모를 기반으로 한 설마천 시험유역의 분기 특성 해석)

  • Kim, Joo-Cheol;Jung, Kwan Sue
    • Journal of Korea Water Resources Association
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    • v.54 no.5
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    • pp.289-299
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    • 2021
  • This study analyzes bifurcation characteristics of the Seolmacheon experimental catchment by extracting the shape variation of channel network due to variable scale of source basin or threshold area. As the area of source basin decreases, a bifurcation process of channel network occurs within the basin of interest, resulting in the elongation of channel network (increase of total channel length) as well as the expansion of channel network (increase of the source number). In the former case, the elongation of channel reaches overwhelms the generation of sources, whereas, in the latter case, the drainage path network tends to fulfill the inner space of the basin of interest reflecting the opposite trend. Therefore, scale invariance of natural channel network could be expressed to be a balanced geomorphologic feature between the elongation of channel network and the expansion of channel network due to decrease of source basin scale. The bifurcation structure of the Seolmacheon experimental catchment can be characterized by the coexistence of the elongation and scale invariance of channel network, and thus a further study is required to find out which factor is more crucial to rainfall transformation into runoff.

Measuring the Goodness of Fit of Link Reduction Algorithms for Mapping Intellectual Structures in Bibliometric Analysis (계량서지적 분석에서 지적구조 매핑을 위한 링크 삭감 알고리즘의 적합도 측정)

  • Lee, Jae Yun
    • Journal of the Korean Society for information Management
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    • v.39 no.2
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    • pp.233-254
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    • 2022
  • Link reduction algorithms such as pathfinder network are the widely used methods to overcome problems with the visualization of weighted networks for knowledge domain analysis. This study proposed NetRSQ, an indicator to measure the goodness of fit of a link reduction algorithm for the network visualization. NetRSQ is developed to calculate the fitness of a network based on the rank correlation between the path length and the degree of association between entities. The validity of NetRSQ was investigated with data from previous research which qualitatively evaluated several network generation algorithms. As the primary test result, the higher degree of NetRSQ appeared in the network with better intellectual structures in the quality evaluation of networks built by various methods. The performance of 4 link reduction algorithms was tested in 40 datasets from various domains and compared with NetRSQ. The test shows that there is no specific link reduction algorithm that performs better over others in all cases. Therefore, the NetRSQ can be a useful tool as a basis of reliability to select the most fitting algorithm for the network visualization of intellectual structures.

Miniaturization of GPS Microstrip Antenna for Small Drone (초소형 드론 탑재용 GPS 대역 마이크로스트립 안테나의 소형화)

  • Kim, Wan-Ki;Woo, Jong-Myung
    • The Journal of The Korea Institute of Intelligent Transport Systems
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    • v.21 no.3
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    • pp.62-72
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    • 2022
  • In this study, a miniaturized GPS band(L1 : 1.575 GHz) antenna that can be mounted on a small drone is proposed. The miniaturization was designed by applying the perturbation method based on the λ/4 microstrip antenna and lengthening the current path at the edge of the patch. The miniaturized antenna was fabricatred such that it could be attached to the surface of styrofoam(εr=1.06, t=10 mm) having a size of 10 mm × 9 mm × 10 mm (0.05 λ × 0.05 λ × 0.05 λ). The thickness and length of the feeding line and the spacing between short stubs were adjusted for impedance matching. S11 was found to be -18.8 dB at the center frequency of the fabricated antenna, 1.575 GHz. The radiation pattern measurement results show that the maximum gain of Eθ is 1.87 dBi in 0 directions in the xz-plane, and that Eθ is an omnidirectional characteristic with an average gain of -1.7 dBi in the yz-plane. It was found that the antenna can be used as an ultra-small microstrip antenna, which can be mounted on a small dron for GPS, and is capable of preserving a reduction ratio of 98.8% as compared to a λ/2 microstrip patch antenna.

Effects of Zeolite Application on Yield and Yield Components in Rice (Zeolite 시용에 의한 벼의 증수효과 및 요인해석)

  • Kae, Bong-Myung;Sol, Kwon-Sok;Cho, Chang-Hwan
    • KOREAN JOURNAL OF CROP SCIENCE
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    • v.32 no.4
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    • pp.403-408
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    • 1987
  • The milled rice yield of the fertilized Zeolite in the sandy loam as 542 Kg/10a was increased by 11% compared with the check plat as a standard cultivation. Significant positive correlations of that were found between grain yield/plant and panicle/total weight ratio or average weight of panicle, while lower correlations between ratio of riqened grains and grain yield/ plant. But significant negative correlations were found between 1,000-grain weight of rough and 4th. 5th internode/culm length ratio. It was reavealed that there were higher direct effects for ratio of ripened grains and spikelets/panicle affecting grain yield/plant through path analysis among the yield components. Moreover, organic dry matter production at 35 days after heading were heavier by 26% in active leaves, 19% in stem + leaf sheath, and 5% in panicle, respectively. Ratio of settled spikelets on the terminal of primary rachis-branch was 47% to total spikelets, and 37% in half-upper of that, moreover many spikelets settled on the terminal of rachis. Therefore, it was recognized that there were a dominant effect of apical glumous flower by fertilized Zeolite.

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Quantitative analysis of hydrogen in thin film by scattering-recoil co-measurement technique (산란-되튐 동시 측정 방법에 의한 박막 중 수소 정량법)

  • Lee, Hwa-Ryun;Eum, Chul Hun;Choi, Han-Woo;Kim, Joonkon
    • Analytical Science and Technology
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    • v.19 no.5
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    • pp.400-406
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    • 2006
  • Hydrogen analysis by elastic recoil detection has been performed utilizing polyimide film as a reference sample of known hydrogen content assuming the soundness of ion beam current integration. However beam current integration at higher incidence angle is not reliable. Scattering yield per unit fluence by current integration which is normalized per unit path length decreases as the sample tilt angle is getting higher. Moreover because beam current integration at high tilt angle is incomplete, hydrogen evaluation is very risky by direct comparison of sequentially collected recoil spectra between reference and target sample. In this study, primary ion beam dose is determined by backscattering spectrum that is collected simultaneously with recoil spectrum instead of ion beam current integration in order to reduce uncertainty arising in the process of current integration and to enhance the reliability of quantitative analysis. Three test samples are selected $-7.6{\mu}m$ polyimide film, hydrogen implanted silicondioxide and Au deposited carbon wafer- and analyzed by two methods and compared.