• Title/Summary/Keyword: 미시

Search Result 694, Processing Time 0.025 seconds

The Financial Crisis of Korean Economy and the Changing Economic Space of Gwangiu City (IMF금융위기와 광주권 경제공간의 변화)

  • 김재철
    • Journal of the Economic Geographical Society of Korea
    • /
    • v.3 no.1
    • /
    • pp.5-20
    • /
    • 2000
  • Recently as globalization of financial capital is progressed, possibility of crisis and unreliability of world economy is more growing. Korean economy required radical restructuring because of the financial crisis and the economic changes occurred in that process. This study is to explain the economic changes of Gwanagju city is produced by the financial crisis of Korean economy The most important industries are service and transportation equipment in Gwangju city. These industries began to decrease after financial crisis but machinery equipment, electrical machinery & electronics and rubber goods & plastic industry is growing relatively. Because of the decrease of service, the economy of inner city which service industry relatively agglomerated in is reducing. And agglomeration space for the optical photonics industry was built up by the upbringing policy of government on high-technology industry to overcome the economic crisis and micro industrial space such as venture building and establishment nursery center was built up. But high-technology industries have many geographical limits to embed in Gwanagju city, so there needs to construct regional innovation system for knowledge based economies

  • PDF

Estimation of Rock Mass rating(RMR) and Assessment of its Uncertainty using Conditional Simulations (조건부 모사 기법을 이용한 암반등급의 예측 및 불확실성 평가에 관한 연구)

  • Hong Chang-Woo;Jeon Seok-Won;Koo Chung-Mo
    • Tunnel and Underground Space
    • /
    • v.16 no.2 s.61
    • /
    • pp.135-145
    • /
    • 2006
  • In this study, conditional simulation was conducted to estimate rock mass rating(RMR) in unsurveyed regions. Sequential Gaussian simulation(SGS) and sequential indicator simulation(SIS) were applied for estimating RMR from the bore hole logging data. The uncertainty of SGS and SIS was verified by sample cross validation. A subset composed of 5 bore hole logging data among the original 30 bore hole logging data was set aside as test data. The remainder was training data. The quality of SGS and SIS estimation on the testing data reflects how well it would perform in an unsupervised setting. SGS and SIS were useful stochastic methods to estimate the spatial distribution of rock mass classes correctly and assess the uncertainty of estimation quantitatively. The result of conditional simulation can offer useful information of rock mass classes such as RMR in unsurveyed regions.

Sensitivity Analysis of the Factors Affecting Traffic Micro-simulation Results (교통 미시 시뮬레이션 결과에 영향을 미치는 요소의 민감도 분석)

  • Kim Kyu-Ok;Shin Chi-Hyun
    • The Journal of The Korea Institute of Intelligent Transport Systems
    • /
    • v.4 no.2 s.7
    • /
    • pp.53-66
    • /
    • 2005
  • Microscopic simulation models, which focus on individual vehicles, are used extensively in the transportation operations in order to capture vehicle to vehicle and vehicle to traffic controls. There are many important factors involved when a micro simulation model is applied as an evaluation tool for the traffic system. They typically include test bed, software, simulation time period, measure of effectiveness, parameter for a software, OD matrix, and random seed number. To evaluate the effects of those factors, sensitivity analysis was performed to identify the effects of those factors based on CORSIM and TRANSIMS results. Three freeway corridors, two in Houston (I-10 and US 290) and one in Sin Antonio (I-37), were chosen as test beds. Three time periods (AM, PM, off-peak) and three OD matrix estimates were used for the analysis. It was found that the micro-simulation results were highly sensitive to the model Parameter sets and the OD information. The degree of sensitivity was a function of the test bed and time period.

  • PDF

Ecosystem Factors that Affect Abandoned Mine Area Residents' Life Satisfaction (생태체계 요인이 폐광지역 주민의 생활만족도에 미치는 영향)

  • Roh, Hyo-Lyun
    • Journal of the Korea Academia-Industrial cooperation Society
    • /
    • v.16 no.10
    • /
    • pp.6869-6877
    • /
    • 2015
  • This study was conducted to figure out measures to improve abandoned mine area residents' life satisfaction from the viewpoint of ecosystems. The subjects of this study were 195 residents aged at least 30 years and structured survey were used collected from April, 3, 2014 to 20. The levels of abandoned mine area residents' mental health were measured using the general mental health scale and the residents' life satisfaction was examined using a life satisfaction scale. The abandoned mine area resident's life satisfaction was a little higher than the middle and their future life satisfaction was shown to be the lowest. Out of the microsystemic factors, mental health degree contributing to the quality of life and those with lower depression and anxiety showed higher life satisfaction. None of the mesosysystemic factors, were not found to influencing the quality of life. Out of the macrosystemic factors were found to be mine area special law in influencing the quality of life. In order to improve the life satisfaction of the mine locals seem to need practical strategies related for maintaining a healthy mind and continued implementation of the economic revitalization policy.

Micromorphological and Chemical Characteristics of Hardwoods Decayed by a Brown-rot Fungus (활엽수 갈색부후재의 미시형태 및 화학적 특성)

  • Cha, Mi Young;Lee, Kwang Ho;Kim, Yoon Soo
    • Journal of the Korean Wood Science and Technology
    • /
    • v.35 no.6
    • /
    • pp.152-158
    • /
    • 2007
  • Micromorphological and chemical characteristics of living Castanea spp. and Tamarix spp. attacked by a brown-rot fungus were examined. Micromorphological features of brown-rotted hardwood species were similar to those observed in softwoods such as losses in birefringence under polarized microscopy, preferential degradation of $S_2$ layer and cracks in the $S_3$ layer. Thinning of the secondary cell wall in fibers was also observed, although it did not seem to be the main symptom. FT-IR analysis showed that bands assigned to cellulose and hemicelluloses decreased or disappeared, whereas the bands assigned to lignin increased. X-ray diffraction analysis exhibited the decrease of relative crystallinity, indicating that degradation of hardwood by a brown-rot fungus was in the advanced stages.

Numerical Modeling of Large Triaxial Compression Test with Rockfill Material Considering 3D Grain Size Distribution (3차원 입도분포를 고려한 락필재료의 대형삼축압축시험 수치모델링)

  • Noh, Tae Kil;Jeon, Je Sung;Lee, Song
    • Journal of the Korean GEO-environmental Society
    • /
    • v.13 no.10
    • /
    • pp.55-62
    • /
    • 2012
  • In this research, the algorithm for simulating specific grain size distribution(GSD) with large diameter granular material was developed using the distinct element analysis program $PFC^{3D}$(Particle Flow Code). This modeling approach can generate the initial distinct elements without clump logic or cluster logic and prevent distinct element from escaping through the confining walls during the process. Finally the proposed distinct element model is used to simulate large triaxial compression test of the rockfill material and we compared the simulation output with lab test results. Simulation results of Assembly showed very well agreement with the GSD of the test sample and numerical modeling of granular material would be possible for various stress conditions using this application through the calibration.

Characterization of Thickness and Thermoelastic Properties of Interphase in Polymer Nanocomposites using Multiscale Analysis (멀티스케일 해석을 통한 고분자 나노복합재의 계면 상 두께와 열탄성 물성 도출)

  • Choi, Joonmyung;Cho, Maenghyo
    • Journal of the Computational Structural Engineering Institute of Korea
    • /
    • v.29 no.6
    • /
    • pp.577-582
    • /
    • 2016
  • In this study, a multiscale method for solving a thermoelasticity problem for interphase in the polymeric nanocomposites is developed. Molecular dynamics simulation and finite element analysis were numerically combined to describe the geometrical boundaries and the local mechanical response of the interfacial region where the polymer networks were highly interacted with the nanoparticle surface. Also, the micrmechanical thermoelasticity equations were applied to the obtained equivalent continuum unit to compute the growth of interphase thickness according to the size of nanoparticles, as well as the thermal phase transition behavior at a wide range of temperatures. Accordingly, the equivalent continuum model obtained from the multiscale analysis provides a meaningful description of the thermoelastic behavior of interphase as well as its nanoparticle size effect on thermoelasticity at both below and above the glass transition temperature.

Safety Assessment of Signalized Intersection Using SSAM : A Case of Actuated Signal Control (SSAM을 이용한 신호교차로 안전성 평가(감응식 교통제어 도입사례를 중심으로))

  • Yun, Il-Soo;Lee, Choul-Ki;Choi, Jin-Hyung;Ko, Se-Jin
    • The Journal of The Korea Institute of Intelligent Transport Systems
    • /
    • v.10 no.6
    • /
    • pp.1-14
    • /
    • 2011
  • The surrogate safety assessment model which was developed based on the conflict theory by FHWA in the US is software to analyze traffic conflicts using the individual vehicle trajectory data from a microscopic traffic simulation model. This study aims at assessing the safety of different signal control strategies, including pre-time and actuated signal control, using the SSAM. To this end, this study effort has developed a microscopic traffic simulation model using VISSIM through a field study, and then produced the surrogate measures, including TTC, PET, DR, MaxS and DeltaS, and the numbers of conflicts, including rear-end, right angle and lane-changing conflicts. The assessment results indicated that the actuated signal control may produce more conflicts in terms of rear-end conflicts. The use of SSAM in the safety assessments for diverse traffic alternatives in a safe and fast way may contribute to the improvement of safety in the roadway transportation.

School Adjustment of Korean-Chinese Children : Ecological Factors in Yanbian (연변 조선족 아동의 학교적응에 대한 생태학적 접근)

  • Cho, Bokhee;Lee, Kwee-ock;Park, Hyewon;Lee, Jin Suk;Han, Sae-young
    • Korean Journal of Child Studies
    • /
    • v.25 no.3
    • /
    • pp.127-140
    • /
    • 2004
  • The subjects of this study were 258 Korean-Chinese parent-child dyads of an elementary school in Yanbian Province, northeastern China. Research questions covered relationships among children's school adjustment and ecological factors, significance of factors within ecological levels, and direct and indirect effects in causal relationships. Results showed significant effects within each ecological level. Achievement motivation of the individual system, home environment and social support of the microsystem, and mother's job satisfaction in the exosystem had significant relationships with children's school adjustment. Mother's education and job satisfaction influenced school adjustment through home environment; the causal relationship between social support and school adjustment was mediated by achievement motivation. Personal and general factors from each ecological level were more significant than ethnic related factors in explaining children's school adjustment.

  • PDF

Numerical Analysis for the Characteristic Investigation of Homogenization Techniques Used for Equivalent Material Properties of Functionally Graded Material (기능경사 소재 등가 물성치 예측을 위한 균질화 기법의 특성분석을 위한 수치해석)

  • Cho, Jin-Rae;Choi, Joo-Hyoung;Shin, Dae-Sub
    • Journal of the Computational Structural Engineering Institute of Korea
    • /
    • v.21 no.1
    • /
    • pp.13-20
    • /
    • 2008
  • Graded layers in which two different constituent particles are mixed are inserted into functionally graded material such that the volume fractions of constituent particles vary continuously and functionally over the entire material domain. The material properties of this dual-phase graded region, which is essential for the numerical analysis of the thermo-mechanical behavior of FGM, have been predicted by traditional homogenization methods. But, these methods are limited to predict the global equivalent material properties of FGMs because the detailed geometry information such as the particel shape and the dispersion structure is not considered. In this context, this study intends to investigate the characteristics of these homogenization methods through the finite element analysis utilizing the discrete micromechanics models of the graded layer, for various volume fractions and external loading conditions.