• Proceedings of the Population Association of Korea Conference
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• 2006.12b
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• pp.67-79
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• 2006

• Journal of radiological science and technology
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• v.14 no.2
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• pp.45-53
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• 1991

SPECT 영상에서 콤프톤 산란 광자는 공간분해능의 감소와 그 양을 측정하는데 있어 정확성과 정밀성을 감소시킨다. 이와같은 콤프톤 산란의 영향을 감소시키기 위하여 사용하는 대부분의 보정방법은 선원의 위치로부터 거리의 단일지수함수로 대칭인 산란분포함수를 고려하게 된다. 본 연구는 균등 및 불균등 산란에 대한 산란분포함수를 얻기 위하여 보다 현실적인 접근방법을 시도하였다. 산란 및 비산란광자의 공간분포와 에너지분포를 얻기 위하여 뼈, 폐, 물의 균등 및 불균등 분포로 된 원통형의 팬톰 속에 $^{99m}Tc$의 선선원 및 점선원을 놓고 Monte Carlo Simulation을 하였으며, 깊이의 함수, media의 접촉영역으로부터 선원거리 및 산란체의 밀도의 변화로 표현한 산란분포함수(SDF)를 얻었다. 산란분포함수는 균등한 뼈, 폐, 물에서는 선원위치로부터 거리의 단일지수함수(single exponential functions)로 대칭으로 나타났으며, 두 물체의 조합에서는 2중지수함수(dual exponential functions)로 비대칭으로 나타났다. 산란분율은 20% window photopeak에서 총 계수의 8%에서 53%까지 다양한 변화가 있었으며, 지수함수의 기울기는 $0.1{\sim}0.9\;cm^{-1}$의 범위로 나타났다. 불균등 산란체에서 얻은 산란분포함수는 SPECT 영상에 있어 콤프톤 산란의 감소에 대한 보다 정확한 보정방법의 개발에 필요한 정보를 제공할 것이다.

• Journal of the Economic Geographical Society of Korea
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• v.17 no.3
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• pp.447-464
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• 2014

Creative industries are important due to the capability of enhancing urban competitiveness. This study is focused on unravelling the uneven growth and geographic distributions of creative industries. The main results are as follows. First, the primary city, Seoul, has too much eminence than the citysize rule suggests, and the creative-industry elasticity is very high compared to population and all industry. Second, Seoul is reinforcing the uneven growth with adjacent cities. Third, the local main cities have little power to enhance creative industries and the local small cities grow randomly. Fourth, each city should have more deliberation in accepting creative industries as an urban growth strategy.

• Journal of Korea Technology Innovation Society
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• v.12 no.3
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• pp.457-470
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• 2009

This paper applies a income mobility method to technology inequality using conditional human capital stock and shows their empirical results during the 1980 to 2000. There are several interesting empirical results coming out this analysis. Among the results, the paper turns out that world technology inequality mobility measurement is significantly higher for rapid formation of human capital stock countries than for slow formation of human capital stock countries. This paper, therefore, suggests that technology policy need to focus on improving the public education structure to recover the rate of return to human capital investment and to speed up technology development and deployment in Korea.

• Journal of the Korean Geographical Society
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• v.42 no.4
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• pp.616-631
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• 2007

Residential differentiation is an academic theme which has been given enormous attention in urban studies. This is due to the fact that residential segregation can be seen as one of the best indicators for socio-spatial dialectics occurring on urban space. Measuring how one population group is differentiated from the other group in terms of residential space has been a focal point in the residential segregation studies. The index of dissimilarity has been the most extensively used one. Despite its popularity, however, it has been accused of inability to capture the degree of spatial clustering that unevenly distributed population groups usually display. Further, the spatial indices of segregation which have been introduced to edify the problems of the index of dissimilarity also have some drawbacks: significance testing methods have never been provided; recent advances in spatial statistics have not been extensively exploited. Thus, the main purpose of the research is to devise a spatial separation measure which is expected to gauge not only how unevenly two population groups are distributed over urban space, but also how much the uneven distributions are spatially clustered (spatial dependence). The main results are as follows. First, a new measure is developed by integrating spatial association measures and spatial chi-square statistics. A significance testing method based on the generalized randomization test is also provided. Second, a case study of residential differentiation among groups by educational attainment in major Korean metropolitan cities clearly shows the applicability of the analytical framework presented in the paper.

• Journal of the Economic Geographical Society of Korea
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• v.3 no.2
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• pp.23-42
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• 2000

This study is to investigate spatial patterns of urban labor market growth driven by marketization process and its implication for understanding regional uneven development in post-reform China. Using a shift share analysis, it shows that the geography of employment growth in China's industrial labor market has closely interacted with the space economy of industrial output, which in turn indicates a deepening of economic reform. By decomposing net employment growth into output and productivity effects, it is shown that the non-state sector holds rapid growth of both output and productivity and contributes to net employment growth through positive net shifts. On the contrary, this study also presents that the state sector with relative decrease in output and productivity holds employment decline effects during the reform period. Since there is a significant spatial dimension for the trend above, it is contended that labor market dynamics together with space economy of industrial production play an important role in determining regional patterns of economic development. In addition, through situating this investigation in the context of structural and institutional changes in the reform period, our understanding of regional patterns of labor market growth will be much furthered.

• Journal of Korean Library and Information Science Society
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• v.44 no.4
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• pp.399-419
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• 2013

This paper conducted the empirical analysis of the behaviors revealed in the eight size distributions of the public libraries in Korea. As a result, the behaviors of complex system appeared in all eight size factors. This means that the sizes of public libraries in Korea were highly polarized. Especially, the zipf's law were found in the size factors such as gross area, number of staffs, volume of books, total budget. And the highly uneven distributions were occurred in the size factors such as membership, number of users, number of borrowers, number of borrowed books. This research outcomes show that a new policy of public libraries is needed to resolve the polarization revealed in the sizes of public libraries in Korea.

• Journal of the Korean Institute of Telematics and Electronics S
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• v.36S no.12
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• pp.51-57
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• 1999

In this paper, an adaptive thresholding of the nonuniformly contrasted images is proposed through using the contrast pre-enhancement of the local regions and the bilinear interpolation between the local threshold values. The nonuniformly contrasted image is decomposed into 9${\times}$9 sized local regions, and the contrast is enhanced by intensifying the gray level difference of each low contrasted or blurred region. Optimal threshold values are obtained by iterative method from the gray level distribution of each contrast-enhanced local region. Discontinuities are reduced at the region of interest or at the characters by using bilinear interpolation between the neighboring threshold surfaces. Character recognition experiments are conducted using backpropagation neural network on the characters extracted from the nonuniformly contrasted document, PCB, and wafer images binarized through using the proposed thresholding and the conventional thresholding methods, and the results prove the relative effectiveness of the proposed scheme.

• Journal of the Economic Geographical Society of Korea
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• v.13 no.3
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• pp.312-334
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• 2010

This paper examines the process of Gyeongbu Highway construction from the standpoint of political economy, which was pursued by President Park Jeong-Hee in the 1960s, focusing on the politics of mobility and demarcation implied in it. As results of examination, it can be argued that Gyeongbu Highway was seen as a powerful element to promote a socio-spatial integration of population and hence to enforce an authoritative political power of the Park regime through creation of mobility; that it has had an strong impact on changing the physical landscape of national space and the spatio-temporal rhythm of everyday life by extending the 'machine space' as a non-place; that it has provided a physical infrastructure on which the period of capital circulation could be reduced through its effect of space-time compression. But Gyeongbu Highway has led serious problems such as uneven regional development, expansion of non-place or alienated place, ecological destruction and pollution. In conclusion, a sustainable politics is suggested to overcome this kind of 'tragedy of highway' and to develop the highway as a true way of political and spatial balance and integration.

• Proceedings of the Korea Water Resources Association Conference
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• 2021.06a
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• pp.41-41
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• 2021

최근 전 세계적으로 급증하는 기후변화의 영향으로 이상기후로 인한 자연재해들의 강도 및 발생 빈도의 증가가 다양한 연구를 통하여 확인되고 있으며, 이를 대비 및 대응하기 위한 방안수립 연구가 세계의 가장 중요한 주제로 부상되고 있다. 우리나라의 경우에는 기후변화에 따른 심각성 문제가 대두되고 있지만 국가적 대응기반조성 및 수자원정책 의사결정에 직접적으로 활용될 수 있는 일관성 있고 통합적인 기후 정보가 부족한 실정이다. 미래 기상 변동성을 나타내는 기후모델은 전 지구적 대규모 기상장(large scale climate pattern)을 비교적 정확하게 묘사하는 것으로 알려져 있으나 모형에 내재해 있는 시·공간적 편의(spatial-temporal bias) 및 불확실성으로 인하여 통계학적 상세화가 필수적으로 요구된다. 이러한 편향성은 일반적으로 지상 관측 자료를 격자에 보간하여 보정하는 방법이 적용되고 있지만, 관측자료의 불연속성 및 관측소의 불균등성으로 인하여 공간적 신뢰성이 낮다. 이에, 본 연구에서는 Bayesian 기반의 Kriging을 통한 공간적 편의보정 및 QDM(quantile delta mapping)을 연계한 새로운 격자 기반의 통계적 상세화 모형 Bayesian Kriging-QDM을 개발하였다. 본 연구를 통하여 산정된 결과는 과거자료에 근거하여 이루어지는 기존의 보수적인 수자원 관리 체계의 위험성을 저감 시킬 수 있는 의사결정에 직접적으로 활용될 수 있는 기초 자료로 이용 가능할 것으로 판단된다.