Earticle

In order to cope with African swine fever, wild boar population density surveys were conducted in four regions of Gangwon-do (Hoengseong, Hongcheong, Yanggu, and Hwacheon), and a study on home range was conducted in Yanggu. Camera trap was used for the wild boar population density survey, and a total of 16 cameras were installed in 4 regions, with 4 cameras in each region. As the results of analyzing the camera trap data collected for six months from November 2020 to May 2021, the average monthly wild boar population densities were 0.1(±0.09)/㎢ in Yanggu, 0.07(±0.09)/㎢ in Hwacheon, 0.06(±0.09)/㎢ in Hongcheon, and 0.04(±0.06)/㎢ in Hoengseong. Home range was calculated based on the movement of 50 days by attaching a GPS transmitter to a wild boar captured in Yanggu (a female of one year age). The area of home range was MCP 100% 12.01㎢, MCP95% 5.42㎢, and MCP50% 1.21㎢.

본 연구는 청설모에 의한 잣구과 피해를 방지하고 효율적인 개체군 밀도 유지를 위한 과학적인 기초자료 를 마련하기 위해 2003년 3월부터 2004년 6월까지 우리나라 잣나무림에 서식하고 있는 청설모(Sciurus vulgaris)의 행동 특성에 대한 연구를 실시하였다. 청설모의 행동권은 2±1 ha였으며 세력권은 1.4±0.7 ha로 잣나무림 내 안정적 인 세력권을 형성하고 있었다. 서식지내에서의 일일 활동 시간은 여름철과 가을철에 오전 과 오후에 각각 1회씩 활동지수가 높은 것으로 나타났다. 실험실내 최초 활동시간은 월별 일출 시간에 따라 최초의 활동시간도 조금씩 차 이가 있는 것으로 나타났으며 서식지별 ha당 서식밀도는 잣나무 임지에서 1.1개체로 임도 지역의 0.9개체 보다 조 금 높게 나타났다.

This study investigates the behavioral characteristics of Sciurus vulgaris coreae inhabiting in pine forest in Korea from March, 2003 till June, 2004 to prevent damage on pine cones caused by Sciurus vulgaris coreae and establish scientific foundational data to maintain the density of population efficiently. Sciurus vulgaris coreae home range was 2±1 ha, and their scope of power was 1.4±0.7 ha, so they built a stable scope of power in the pine cone forest. Regarding the daily activity hours in the habitat, they showed a high activity index separately once in the morning and in the afternoon during summer and winter. About the initial activity hours in the lab, there was slight difference of initial activity hours by the time of sunrise of each month. And the population density per ha in the habitat was 1.1 population in the pine forest, so it was slightly higher than 0.9 population of the forest road.

Recently, the cattle genome sequence has been completed, followed by developing a commercial single nucleotide polymorphism (SNP) chip panel in the animal genome industry. In order to increase statistical power for detecting quantitative trait locus (QTL), a number of animals should be genotyped. However, a high-density chip for many animals would be increasing the genotyping cost. Therefore, statistical inference of genotype imputation (low-density chip to high-density) will be useful in the animal industry. The purpose of this study is to investigate the effect of the reference population size and marker density on the imputation accuracy and to suggest the appropriate number of reference population sets for the imputation in Hanwoo cattle. A total of 3,821 Hanwoo cattle were divided into reference and validation populations. The reference sets consisted of 50k (38,916) marker data and different population sizes (500, 1,000, 1,500, 2,000, and 3,600). The validation sets consisted of four validation sets (Total 889) and the different marker density (5k [5,000], 10k [10,000], and 15k [15,000]). The accuracy of imputation was calculated by direct comparison of the true genotype and the imputed genotype. In conclusion, when the lowest marker density (5k) was used in the validation set, according to the reference population size, the imputation accuracy was 0.793 to 0.929. On the other hand, when the highest marker density (15k), according to the reference population size, the imputation accuracy was 0.904 to 0.967. Moreover, the reference population size should be more than 1,000 to obtain at least 88% imputation accuracy in Hanwoo cattle.

Although camera traps have been widely used to understand the abundance of wildlife in recent decades, the effort has been restricted to small sub-set of wildlife which can mark-and-recapture. The Random Encounter Model shows an alternative approach to estimate the absolute abundance from camera trap detection rate for any animals without the need for individual recognition. Our study aims to examine the feasibility and validity of the Random Encounter Model for the density estimation of endangered leopard cats (Prionailurus bengalensis) in Maekdo riparian park, Busan, South Korea. According to the model, the estimated leopard cat density was 1.76 km-2 (CI 95%, 0.74-3.49), which indicated 2.46 leopard cats in 1.4 km2 of our study area. This estimate was not statistically different from the previous leopard cat population count (2.33±0.58) in the same area. As follows, our research demonstrated the application and usefulness of the Random Encounter Model in density estimation of unmarked wildlife which helps to manage and protect the target species with a better understanding of their status.

As of October 2021, the COVID-19 pandemic is still raging around the world and people’s lifestyles have also been changed. COVID-19 can spread through minute droplets, which makes it easy to transmit (especially the Delta variant). For most of 2020, vaccines were not available and the most effective way is to control the spread of the virus was social distancing and quarantine. Social distancing is very important to mitigate the spread of COVID-19 and population density becomes a crucial factor. Another way to deal with this coronavirus pandemic is vaccination. Wealthy countries, which have more healthcare expenditure, begin to develop vaccines in 2020 or invest in pharmaceutical companies to secure the supply of vaccines. Healthcare expenditures are closely related to a country’s GDP. This research studies the impact of GDP and population density on the spread and control of COVID-19.

This study deals with the CBD's decline of large cities with 500-1,000 thousands population. The purposes are 1) to analyze the change of population centroid over time with respect to CBD and center of area by city, and 2) to model the dispersion and crater phenomenon over time using the distance from CBD which is an explanatory variable. The main results are the followings. First, three centroid change patterns are analyzed, which are the types of one-direction expansion, circular expansion and stationary state. Second, the population density distribution models which are all statistically significant are developed. According to the dispersion index, 12 cities are divided as three types which are the decreasing, decreasing after increasing, and the others. Finally, 3 cities which are Cheongju, Cheonan and Suwon are analyzed to have the crater phenomenon.

다도해해상국립공원 칠발도에서 번식하는 바다제비의 번식밀도 및 번식 개체군을 알아보기 위해 고정조 사구 5개(5 × 5 m)를 설정하여 2년간 모니터링을 실시하였다. 바다제비의 평균 밀도(번식쌍수/1 m2)는 2014년에 0.7쌍, 2015년에 0.9쌍이었다. 이를 바탕으로 칠발도 전체의 바다제비 번식개체군을 추정한 결과 2014년과 2015년에 각각 9,825쌍과 12,787쌍이 번식하는 것으로 나타났다. 두 해 번식개체군은 통계적으로 유의한 차이는 없었다. 칠발도는 바다제비의 개체군 보전을 위해 매우 중요한 지역으로 이들의 번식 및 피해현황을 파악하고 장기적으로 번식 개체 군 변화 모니터링이 필요하다.

This study is breeding density and estimation population size of the Swinhoe's Storm Petrel for monitoring on Chilbal-do(Is.), Dadohaehaesang National Park, from these two years. Average nest density per 1 m2 was 0.7 pairs in 2014 and 0.9 pairs in 2015. Estimation population size was 9,825 pairs in 2014 and 12,787 pairs in 2015, which no significant for two years. Chilbal-do is very important area for the populations conservation of the Swinhoe's Storm Petrel. Therefore, their breeding and damage status and need long-term monitoring of changes in breeding populations.

This study examined associations between diverse accessibility indicators and population and business density using Extreme Gradient Boosting Decision Tree Regressor (XGB) and Interpretable Machine Learning (XAI). The main results are as follows. First, the results of feature importance reveal that the accessibility indicators exerted a more considerable contribution to predicting the density than control variables. Specifically, accessibility to hospitals appeared to have the most significant impact on explaining population and business density. In addition, accessibility to elementary, middle, and high schools showed high importance in explaining the population density, while it was found to have a smaller importance in explaining the business density. Second, findings of partial dependence plots derived non-linear relationships between accessibility and density. For instance, the population or business density was highest when the travel time to elementary, middle, and high school was between 5 and 7 minutes. This study contributes to (1) offering a more detailed understanding of the relationship between transportation accessibility and density and (2) providing associated discussions and policy implications.

Precision of pests, in stored grain insect population density, has been a hot and difficult research in pest detection and control system. The accuracy of prediction of pest density will directly affect to warehouse grain temperature and the food quality etc. In order to improve the accuracy, the paper which using the depth study method, established an insects density prediction mode with the depth of the belief network as the core. The model is applied to the algorithm of deep learning predictive control. According to the temperature and humidity of the grain obtained from the actual measurement and the initial density of the pest, we predicted the pest density. Simulation results show that the root mean square error is small between the predictive value and actual value, high prediction accuracy. The deep learning algorithm is applied to the population density of pests is effective.

이 논문에서는 서울, 부산, 대전, 대구, 광주의 5대 대도시를 분석대상으로 하여 도시별로 인구밀도 경사도 (Population Density Gradient)를 추정하였다. 기본적으로 우리나라 대도시의 인구밀도 경사도와 도심지역의 인구는 시간이 지남에 따라 감소하는 경향이 나타나고 있으며, 이는 교외화(Suburbanization)가 지속적으로 이루어지고 있음을 의미한다. 또한 더 나아가 도시의 어떤 특성들이 이러한 도심지역 인구 비율 감소에 영향을 주었는지를 1995년 우리나라 73개 도시의 동별 자료를 이용하여 분석하였다. 분석결과, 도시 거주자의 교육수준이 높을수록 그리고 재정자립도가 높거나 인구성장률이 높은 도시일수록 도심의 인구비율이 낮은, 즉 인구의 교외화가 발생한 것으로 분석되었다. 추가적으로 전철이나 지하철과 같은 교통시설이 잘 되어 있는 도시 일수록 그리고 금융보험업과 부동산 임대업 같은 정보 중심의 산업이 해당 도시의 핵심 산업인 도시는 도시발달 단계가 높은 도시로서 이들 도시에서는 도심의 거주 기능이 상실하는 도심공동화 현상이 발생하는 것으로 나타났다. 이러한 도심인구 비율 감소의 요인분석을 근거로 하여 도심공동화 현상을 해소하기 위한 시정부의 정책방안을 검토하였다. 도심공동화 현상에 대처하기 위해서는 도심의 주거기능 확보가 필요하며 이를 위해서는 도심의 주거지역을 조사하여 지역유형별로 파악할 필요가 있다. 주거기능과 상업기능이 혼재하여 주거지역으로서의 쾌적성을 상실한 지역과 주거기능이 비교적 잘 유지된 지역 등을 선별하여 다른 용도로의 전환을 억제할 수 있는 조치를 강구할 필요가 있다. 또한 인구 교외화는 높은 기동성을 가지면서 환경의 질을 중시하는 중간 소득계층을 중심으로 이루어지고 있다. 따라서 이러한 중간 소득계층에게 적합한 평형 및 설계를 통해 다양한 가격대의 주택을 공급함과 동시에 도심 정부는 도심의 주거환경과 생활 여건을 쾌적하게 유지할 수 있도록 무분별한 난개발을 억제하고 공원과 녹지공간의 확보를 위해 노력해야 할 것이다. 최근 이러한 구도심 활성화를 위한 노력의 일환으로 ‘도시재생’(산업구조의 변화나 신도시 위주의 도시 확장으로 상대적으로 낙후된 기존 도시에 새로운 기능을 도입)사업이 추진되고 있다. 이러한 정책은 국가적 차원에서도 필요하지만 근본적으로 지방자치단체와 민간이 함께 참여하여 추진하는 민관합동 대책이 동시에 추진될 때 더 큰 시너지 효과를 구현할 수 있을 것이다.

We estimated population density gradients for five major cities of Korea, namely, Seoul, Pusan, Daejeon, Taegu and Gwangju to explain changes in the internal spatial structure of cities. Basically, population density gradients of large cities in Korea and population in the city center areas tend to decline over the time, which indicates the suburbanization is continuously taking place. Furthermore, we have analyzed the effects of basic characteristics of a city on the size of population in central areas of the city. Higher education level of residents, high level of financial independence, high level of population growth rate, and high ratio of automobile users caused suburbanization reducing population in the city center. Additionally, cities with good subway and other public transportation facilities, and cities with active information processing sectors where the finance, security and real estate industry becomes a core industry are considered to be cities with high level of urban development. In such cities, the phenomenon of city center doughnut hole in which residential function is eradicated from the city center takes place. In order to avoid a rapid decrease of city center’s population, the city center must maintain residential functions. To achieve this goal, it is essential to investigate the dynamics of the residential areas in a city in depth and to acquire a full understanding of the factors causing the differences in city center's population shares among various cities.

본 연구의 주된 목적은 벡터-기반 보조 정보를 사용하는 대시메트릭 매핑의 방법론을 정련화하고, 그것의 GIS-기반 실행 프로그램을 개발하여, 2000년 서울시 인구밀도 분포도 제작에 적용하는 것이다. 대시메트릭 매핑은 해당 변수와 공간적 연관성을 가지는 보조 정보를 사용하여, 해당 변수의 분포 패턴을 보다 정확하게 재현하는 지도화 방식을 의미한다. 즉, 대시메트릭 매핑은 임의적인공간단위의 데이터를 보조 자료를 이용하여 변환함으로써 기저에 있는 통계적 밀도면(statistical density surface)를 복원하여 제시하는 주제도 제작 기법이다. 중요한 연구 결과는 다음과 같다. 첫째, 보조 정보가 가진 범주의 수와 범주 별 가중치 산출 방식을 모두 포괄하는 다중-클래스 대시메트릭 매핑의 일반식이 도출되었다. 둘째, 기존의 연구들에서 사용된 가중치 부여 방식을 정리하여‘인구 비중법’,‘ 표준 밀도법’,‘ 회귀분석법’으로 체계화하였다. 셋째, GIS 환경 하에서 대시메트릭 기법이 실행되는 프로그램이 제작되었다. 넷째, 서울의 2000년 522개 동 별 인구 수를 기본 데이터로 하고 벡터-기반의 토지이용현황도를 보조 정보로 하여 세 종류의 대시메트릭 매핑을 실시한 결과 코로플레스 매핑 보다는 기저의 통계적 밀도면을 보다 잘 반영하는 인구밀도 분포도가 제작되었다.

The main purpose of the research is to refine the dasymetric mapping technique based on vector-based ancillary data, to develop a program implemented in a GIS environment, and to apply the GIS-based dasymetric mapping techniques to population data of Seoul in 2000. Dasymetric mapping can be defined as a mapping technique to represent spatial distribution of a variable under investigation more accurately by utilizing ancillary data whose distribution is associated with that of the given variable. In other words, dasymetric mapping is a procedure of making a thematic map to recover and reveal the underlying statistical density surface by manipulating the data given in an arbitrary zoning system by reference to ancillary data. The main results are as follows. First, a generalized equation for dasymetric mapping was derived, which could be applied to any mapping situations, regardless of the number of categories in ancillary data and of the weighting scheme allocating a weight to each of the categories. Second, three different weighting schemes were identified by critically reviewing the methods presented in previous works: population proportion method, standard density method, and regression method. Third, a GIS-based program implementing dasymetric mapping techniques was developed. Fourth, population density maps which were believed to be better reflective of the underlying population density surface especially in comparison with choropleth maps were created for Seoul 2000. Those maps were drawn by applying three different dasymetric mapping procedures to the census 2000 population data as source data and a vector-based land use data as ancillary information.

In this paper the use of panchromatic KOMPSAT-1 imagery is proposed to provide detailed information on built-up areas in suburban regions. In order to derive this information a texture analysis is utilized. In the next processing step census data are incorporated in order to perform refined demographic analysis. Assuming that the population lives in settlements rather than in agricultural areas, the census data are assigned to the actual residential areas within each census unit. Using this information a number of questions can be addressed which cannot be answered by statistical data alone.

The black soldier fly is economically important because its prepupae are used as feed for many animals, including fish and swine. In Korea, black-soldier-fly farms have attempted to increase annual breeding and mass egg production for use in animal feed, as well as the decomposition of organic waste. Such efforts require an understanding of optimal mating and oviposition techniques. Specifically, adult densities and cage size may both improve the efficiency of mass egg production. Our study used four sizes of nylon cages ($1.0{\times}1.0{\times}2.5m$, $1.5{\times}1.5{\times}2.5m$, $2.0{\times}2.0{\times}2.5m$, $2.5{\times}2.5{\times}2.5m$) and three density treatments (4 kg, 8 kg, and 10 kg of pupae) to investigate optimal habitat size and adult density. We found that cage size (independent of density) did not significantly influence female fecundity (number of egg clutches and egg weight), whereas higher densities increased egg number and weight regardless of cage size. Thus, we recommend manipulating adult density to enhance productivity in commercial black-soldier-fly farming. However, we also propose further detailed research to develop methods that account for seasonal changes and environmental conditions, as climatic variables (temperature, sunlight) likely influence female fecundity as well.

Using a cross section of countries, this paper examines the association between regional population densities in 1500 AD and current income inequality. After controlling for other regional and historical factors, I find that past population density is negatively associated with income inequality today. Formerly high density regions are predicted to have lower income inequality. These findings support the view that higher density areas were better able to form more diverse and mobile societies that affected the long-run distribution of income.

단계구분도는 인구분포를 나타내기 위해 흔히 사용되는 방법으로 인구가 단위지역 내에 균등하게 존재함을 가정한다. 대시메트릭 지도제작법은 주거지역 정보를 통해 단계구분도보다 공간적으로 더 세밀한 인구분포를 작성할 수 있게 한다. 또한 피크노필랙틱 보간법은 단위지역 내 총인구를 유지하면서 주변지역의 인구를 고려하여 인구분포를 보간하는 방법으로 대시메트릭 지도제작법에 의한 인구분포를 연속적이고 부드럽게 하여 좀더 현실적인 인구분포도를 작성할 수 있게 한다. 따라서, 본 연구에서는 대시메트릭 지도제작법과 피크노필랙틱 보간법을 연계하는 방법을 제시하여 인구분포도의 정확도를 향상하고자 하였다. 제시한 방법을 적용하여 인구분포도를 작성하기 위해 1990년도 미국조지아주 Athens 시의 인구자료와 위성영상으로부터 추출된 주거지역 자료를 활용하였다. 결과를 검증하기 위해 인구분포도 작성에 활용된 공간단위보다 더 세밀한 공간단위의 인구자료를 활용하였으며 하이브리드 방법에 의해 높은 정확도를 확보할 수 있음을 확인하였다. 본 연구에서 제시한 하이브리드 대시메트릭에 의한 인구분포는 선거구, 학군, 분수계 등 각종 경계지역으로 변환이 용이해 다양한 응용분야에서 활용될 수 있을 것이다.

Choropleth mapping of population distribution is based on the assumption that people are uniformly distributed throughout each enumeration unit. Dasymetric mapping technique improves choropleth mapping by refining spatially aggregated data with residential information. Further, pycnophylactic interpolation can upgrade dasymetric mapping by considering population distribution of neighboring areas, while preserving the volumes of original units. This study proposed a combined solution of dasymetric mapping and pycnophylactic interpolation to improve the accuracy of population density distribution. Specifically, the dasymetric method accounts for the spatial distribution of population within each census unit, while pycnophylactic interpolation considers population distribution of neighboring area. This technique is demonstrated with 1990 census data of the Athens, GA. with land use land cover information derived from remotely-sensed imagery for the areal extent of populated areas. The results are evaluated by comparison between original population counts of smaller census units (census block groups) and population counts of the grid map built from larger units (census tracts) aggregated to the same areal units. The estimated populations indicate a satisfactory level of accuracy. Population distribution acquired by the suggested method can be re-aggregated to any type of geographic boundaries such as electoral boundaries, school districts, and even watershed for a variety of applications.

As the rapid and various changing of social aspects, the structures are getting bigger, higher and more complex. The importance of evacuation is on the rise as increased using frequency of multiplex sale facility and it's high population density. According to the result of a survey with 4 domestic wholesales mart's population density, the average and maximum was 0.41(人/$m^2$) and 0.46(人/$m^2$). considering evacuation dangerousness, the maximum value will be suitable for computation of evacuation capacity and this will be submitted as a basic data for computation of evacuation capacity.

Natural and beneficial associations between plants and bacteria have demonstrated potential commercial application for several agricultural crops. The sunflower has acquired increasing importance in Brazilian agribusiness owing to its agronomic characteristics such as the tolerance to edaphoclimatic variations, resistance to pests and diseases, and adaptation to the implements commonly used for maize and soybean, as well as the versatility of the products and by-products obtained from its cultivation. A study of the cultivable bacteria associated with two sunflower cultivars, using classical microbiological methods, successfully obtained isolates from different plant tissues (roots, stems, florets, and rhizosphere). Out of 57 plant-growth-promoting isolates obtained, 45 were identified at the genus level and phylogenetically positioned based on 16S rRNA gene sequencing: 42 Bacillus (B. subtilis, B. cereus, B. thuringiensis, B. pumilus, B. megaterium, and Bacillus sp.) and 3 Methylobacterium komagatae. Random amplified polymorphic DNA (RAPD) analysis showed a broad diversity among the Bacillus isolates, which clustered into 2 groups with 75% similarity and 13 subgroups with 85% similarity, suggesting that the genetic distance correlated with the source of isolation. The isolates were also analyzed for certain growth-promoting activities. Auxin synthesis was widely distributed among the isolates, with values ranging from 93.34 to 1653.37 ${\mu}M$ auxin per ${\mu}g$ of protein. The phosphate solubilization index ranged from 1.25 to 3.89, and siderophore index varied from 1.15 to 5.25. From a total of 57 isolates, 3 showed an ability to biologically fix atmospheric nitrogen, and 7 showed antagonism against the pathogen Sclerotinia sclerotiorum. The results of biochemical characterization allowed identification of potential candidates for the development of biofertilizers targeted to the sunflower crop.