• 한국IT서비스학회지
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• 제21권3호
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• pp.63-72
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• 2022

The extinction crisis of local cities, caused by a population density increase phenomenon in capital regions, directly causes the increase of vacant houses in local cities. According to population and housing census, Gunsan-si has continuously shown increasing trend of vacant houses during 2015 to 2019. In particular, since Gunsan-si is the city which suffers from doughnut effect and industrial decline, problems regrading to vacant house seems to exacerbate. This study aims to provide a foundation of a system which can predict and deal with the building that has high risk of becoming vacant house through implementing a data driven vacant house prediction machine learning model. Methodologically, this study analyzes three types of machine learning model by differing the data components. First model is trained based on building register, individual declared land value, house price and socioeconomic data and second model is trained with the same data as first model but with additional POI(Point of Interest) data. Finally, third model is trained with same data as the second model but with excluding water usage and electricity usage data. As a result, second model shows the best performance based on F1-score. Random Forest, Gradient Boosting Machine, XGBoost and LightGBM which are tree ensemble series, show the best performance as a whole. Additionally, the complexity of the model can be reduced through eliminating independent variables that have correlation coefficient between the variables and vacant house status lower than the 0.1 based on absolute value. Finally, this study suggests XGBoost and LightGBM based machine learning model, which can handle missing values, as final vacant house prediction model.

• 토지주택연구
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• 제14권2호
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• pp.73-82
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• 2023

본 연구에서는 지난 10년 동안 인구가 증가하고 있는 강원도 내 군 지역 중에서 인구감소폭이 증가하고 있는 홍천군을 대상으로 인구유입에 대한 정책수요를 실증분석하였다. 다항로짓모형을 활용한 본 연구의 분석결과를 통한 정책적 시사점은 다음과 같다. 첫째, 청장년층과 고령층의 인구유입 정책 수요에 영향을 미치는 요인은 상이하기 때문에, 기초 지자체에서는 인구유입을 위한 정책 대상(target)을 명확히 할 필요가 있다. 둘째, 기업유치를 통한 인구유입에 대한 정책수요의 경우 청장년층은 강원도 거주기간이, 고령층은 정규학력 수준이 통계적으로 유의미하게 긍정적인 영향을 미치고 있다. 따라서 기업유치를 통해 인구유입을 확대하기 위해서는 청장년층은 거주기간을, 고령층은 정규학력 수준을 고려해 지원할 필요가 있다. 이상의 분석결과, 전형적인 농촌지역인 홍천군의 인구유입을 위해서는 세대를 구분한 맞춤형 인구유입 정책을 수립할 필요가 있다. 특징적인 것은 고령층의 경우 정규학력 수준이 기업유치 및 일자리지원 정책 수요에 긍정적인 수요를 미치고 있다. 하지만 청장년층의 경우 인구통계학적 특징보다는 일자리기회 및 소득수준 만족도가 일자리지원 수요에 영향을 미치고 있다. 따라서 청장년층과 고령층의 세대를 구분한 인구유입을 위한 적극적인 정책 수립이 필요하다.

• 문화기술의 융합
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• 제9권6호
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• pp.131-136
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• 2023

지방을 떠나 수도권으로 이동하는 청년들이 나날이 늘고 있다. 청년 유출의 요인을 파악하기 위한 연구들이 다양하게 진행되고 있으나 각 지방별로 분석하는 연구는 부족한 실정이다. 이에 따라 본 연구는 부산의 청년 인구 유출 요인을 분석하고, 머신러닝 기법을 사용해 청년 인구 유출 위험 등급을 예측하고자 한다. 국가통계포털에서 수집한 부산의 구별 데이터를 활용하여 나이대(20대 초반, 20대 후반, 30대 초반)별로 세 그룹으로 나눈 뒤, 의사결정나무와 랜덤 포레스트 알고리즘을 이용해 청년 인구 유출 위험 등급을 분류하고 예측한다. 그 결과, 청년 인구 유출 위험 등급 예측 모델은 나이 그룹별 각각 최고 정확도 0.93, 0.75, 0.63을 갖는다.

• Journal of Information Technology Applications and Management
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• 제30권1호
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• pp.33-52
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• 2023

This study observes the difference in the actual regional ripple effect of the decrease in admission resources due to the decrease in school age population, which has been weak in empirical studies, and how much the decrease in competition rate by department nationwide provides a significant shock to the decrease in enrollment rate in the population unit. An empirical quantitative analysis was attempted. As a result of applying the panel-tobit regression model, a clear gap was confirmed in the decrease in the registration rate due to the decrease in the competition rate both nationally and in the provinces, and in particular, a highly significant relationship was derived with the decrease in the recruitment rate. In particular, the sensitivity of the risk of unrecruitment due to a decrease in competition rate was the highest in the Jeolla region (0.499), followed by the Gangwon region (0.475) and the Gyeongsang region (0.471), and the metropolitan region (0.158) was confirmed to be the most stable. This suggests that the gap in insufficient funding has gradually widened by region over the past 10 years, and that the shock wave becomes more pronounced in the provinces farther away from the metropolitan area. Based on this study, if we deviate from the standardized application of university development policies for the metropolitan area and regional universities, and present a customized higher education strategy for each region, it will be an opportunity to prevent local extinction due to a decrease in the school-age population and achieve coexistence with higher education institutions and regions at the same time.

• 정보처리학회논문지B
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• 제17B권1호
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• pp.79-84
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• 2010

두 개의 이차원 단백질 전기영동 영상에서 한쪽 영상의 각 반점이 다른 영상의 어느 반점과 일치하는 지 알아내는 일은 단백질의 생성과 소멸, 변이 등을 알 수 있게 하는 중요한 일이다. 단백질 반점은 주로 2차원 전기영동에 의해 분리된다. 이 과정은 조직의 상태, 실험 조건 등에 따라 같은 단백질이라도 그 위치가 조금씩 다르게 된다. 각 반점을 정합하여 보면 균일하지 않은 비선형 변환 관계를 이룬다. 그러나 국지적으로 보면 반점 사이의 토폴로지가 유지되는 것을 볼 수 있다. 본 연구는 이러한 토폴로지의 유지에 착안하여 반점끼리 정합하는 방법을 제안한다. 토폴로지의 유사성을 비교하기 위하여 이웃한 반점과의 거리와 각도를 비교하였다. 실험을 통하여 제안한 방법이 우수함을 보였다.

• Journal of Electrical Engineering and Technology
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• 제8권6호
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• pp.1530-1541
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• 2013

The coexistence and extinction of species are important concepts for biological systems and can be distinguished by an investigation of stability. When determining local stability of nonlinear systems, Lyapunov indirect method based on the Jacobian linearization has been widely employed due to its simplicity. Despite such popularity, it is not applicable to singular systems whose Jacobian has at least one eigenvalue that is equal to zero. In such singular cases, an appropriate Lyapunov function should be sought to determine the stability of systems, which is rather difficult and quite involved. In this paper, we seek for a simple criterion to determine stability of the equilibrium that is located at the boundary of the positive orthant, when one of eigenvalues of the Jacobian is zero. The goal of the paper is to present a generalized condition for the equilibrium to attract all trajectories that starting from initial condition in the positive orthant and near the equilibrium. Unlike the Lyapunov direct method, the proposed method requires just a simple algebraic computation for checking the stability of the critical point. Our approach is applied to various biological systems to show the effectiveness of the proposed method.

• 천문학회보
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• 제37권1호
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• pp.80.2-80.2
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• 2012

We firstly present the unified Far-UV continuum map of the Taurus-Auriga-Perseus (TPA) complex, one of the largest local associations of dark cloud located in (l, b)=([152,180], [-28, 0]), by merging both FIMS and GALEX. The FUV continuum map shows that dust extinction correlate well with the FUV around the complex. It says strong absorption in the dense Taurus cloud and Auriga cloud. Although the column density of Perseus and California cloud is similar to Taurus' and Auriga's, Perseus and California cloud do not show strong absorption in FUV because they are more distant than Taurus and Auriga cloud. We also present the dust scattering simulation based on Monte Carlo Radiative Transfer technique. Through the result of Monte-Carlo dust scattering simulation and comparing the result with FIMS-GALEX unified map we gain deeper understanding related to the spatial dust distribution of TPA region. As a preliminary result of the simulation we present the most probable front face, thickness, albedo, and asymmetry factor in this region, respectively. Through this work we can show a certain inclination of the spatial dust distribution. During this study we have developed the FUV dust scattering simulation code using Monte-Carlo method. We expect that it will be generally used to simulate dust scattering in the Galaxy.

• 천문학회지
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• 제22권1호
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• pp.63-79
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• 1989

Current estimates, based on the same star-count analysis, of the distance to the globule Bamard 361 range from 300 pc to 650 pc. All the problems associated with the estimates have been fully rectified in this study, and a modification has been made to the classical Wolf diagram to improve the accuracy in the distance determination. A reference field was carefully selected close to the globule but well outside the globule boundary, and star counts for this field were performed on the blue POSS plate in order to set up the reference magnitude sequence appropriate to the general area of B 361. From the reference sequence, the stellar density function has been derived specifically for the direction toward the globule. Correction was made for the general interstellar extinction, and the luminosity function with the Wielen's dip was adopted. The resulting density function clearly reveals the existence of the local Cygnus-Orion arm in the direction of B 361 at about 700 pc away from the Sun. Analysis of the star-count data for the program field locates the globule at distance $600{\pm}50$ pc ; thus, the globule is an object located in the Cygnus-Orion arm, residing somewhat toward its leading edge.

• 천문학회보
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• 제35권1호
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• pp.71.1-71.1
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• 2010

We present the FUV continuum map of The Taurus-Auriga-Perseus complex, which is one of the largest local association of dark clouds. The map is well consistent with the dust extinction and the CO emission map of the T-P-A region. The region is divided into 3 sub-regions by diffuse FUV intensities and the spectra of each region imply that the radiation field due to the Per OB2-association can be a main source of the H2 fluorescent emission of the nearby cloud region. We used the PDR H2 model, named CLOUD, developed by van Dishoeck &Black for the sake of comparing our results to the H2 model.

• Journal of Crop Science and Biotechnology
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• 제10권3호
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• pp.141-146
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• 2007

The roots of Aristolochia elegans Mast.(Aristolochiaceae) are widely used in Mexican traditional medicine as a remedy for scorpion venom. Current experimental evidence supports its purported antidote properties. However, collection from the wilderness has lead to local extinction of natural populations. In order to contribute to species preservation, cultivation, and standardization of morphological and pharmacological properties, a micropropagation method was developed. This includes in-vitro germination of seeds to produce aseptic plantlets, induction of multiple budding, and acclimatization. The treatment with benzylamino purine(10 ${\mu}M$) induced the highest number of buds(3.1 on average) in both types of explants. On the other hand, indolebutyric acid(1.5 ${\mu}M$) caused the highest root index(11.8) per explant. One hundred percent of the micropropagated plantlets developed vigorously after the acclimatization process.