• The Korean Journal of Applied Statistics
• /
• v.35 no.1
• /
• pp.1-17
• /
• 2022

We propose a test of consistency for two differentially private histograms using parametric bootstrap. The test can be applied when the original raw histograms are not available but only the differentially private histograms and the privacy level α are available. We also extend the test for the case where the privacy levels are different for different histograms. The resident population data of Korea and U.S in year 2020 are used to demonstrate the efficacy of the proposed test procedure. The proposed test controls the type I error rate at the nominal level and has a high power, while a conventional test procedure fails. While the differential privacy framework formally controls the risk of privacy leakage, the utility of such framework is questionable. This work also suggests that the power of a carefully designed test may be a viable measure of utility.

• Proceedings of the Korea Information Processing Society Conference
• /
• 2022.11a
• /
• pp.365-367
• /
• 2022

본 논문에서는 서울시를 대상으로 2020년 기준 자치구별 공공체육시설의 개수를 분석하고, 도출된 서비스 지역 적정 개소 수를 기준으로 추가 설치가 필요한 자치구 내 입지를 예측하였다. 기존 공공 체육시설 수와 선행연구의 입지 지표를 활용해 회귀분석을 바탕으로 유의한 입지요인을 도출하고, 이를 변수로 한 k-means 군집화를 통해 자치구별 입지 후보군이 될만한 행정구역상 동을 구분하였다. 이후 선정된 행정구역 내 기준 인구 당 공공체육시설 비율이 같아지도록 공공체육시설 설치 개수를 결정한 다음 각 구역의 중심점으로부터 가까운 동 순으로 공공체육시설의 추가 설치가 필요한 동을 선정하였다.

• The Korean Journal of Applied Statistics
• /
• v.33 no.6
• /
• pp.739-751
• /
• 2020

Seoul public bike program facilitates access to bicycles and offers potential for greater mobility and health for users. Furthermore, it would have positive impacts on transport congestion, energy use, and the environment. Hence, it is important to find future rental locations by taking to account both bike-demand and regional imbalance. This paper first finds eligible candidates of rental locations with the required spatial conditions such as a sufficient sidewalk width and accessibility of bike pick-up vehicles. And then, estimates public bike daily usage for each selected location via random forest based on Seoul public bike historical usage, Seoul geographical features, regional characteristics, and populations. This study contributes to a better comprehension of the Seoul public bike program, and would be useful in determining new public bike rental locations.

• Journal of Technology Innovation
• /
• v.25 no.2
• /
• pp.1-34
• /
• 2017

This paper seeks to explore the effects of the board structure and director characteristics on the R&D investment of a company. The results from analyzing 95 Korean listed companies reveal that the directors' demographic characteristics substantially affect the R&D intensity. When the directors are younger, major in science or engineering, and have an experience of studying abroad, they tend to be supportive of R&D, thereby increasing the R&D expenditure. Particularly, the effects of insider directors are shown to be greater than those of outside directors, which implies that the Korean corporate boards are mainly operated by insiders. Furthermore, when the relative power of boards is greater than the management, the effects of inside directors, rather than overall directors, on R&D intensity are weakened.

• The Journal of Society for e-Business Studies
• /
• v.19 no.3
• /
• pp.125-141
• /
• 2014

Nowadays, overflowing data produced every second from the internet make people to be difficult to search for the useful information. That's why people have invented and developed unique tools that they get some relevant information. In this paper, the recommender system, one of the effective tools, is used and it helps us to get the useful information that we want by using demographic information to predict new items of interest. The demographic recommender system in this paper computes users' similarity using demographic information, age and gender. So we performed demographic analysis on movie ratings on Internet Movie Database (IMDB) web site that movies are rated by thousands of people, where users submitted a movie rating after they watched a recent popular film. Meanwhile, we can understand that user's ratings, among various determinants of box office, is very essential factor in the study on recommendation of movie. This paper is aimed at analyzing movie average ratings directly given by film viewers, categorizing them into groups by sex and age, investigating the entire group and finding the representative group by examining it with F-test and T-test. This result is used to promote and recommend for the target group only. Therefore, this study is considerably significant as presenting utilization for movie business as well as showing how to analyze demographic information on movie ratings on the web.

• Survey Research
• /
• v.10 no.3
• /
• pp.21-36
• /
• 2009

This study suggests the applicability of web surveys regarding elections in order to contact a great number of young people. The propensity weighting model was estimated using the demographic variables and the covariate variables collected during the 2007 presidential election surveys. In order to adjust the internet survey to the telephone survey, we used the propensity score method. Propensity score weighting made the internet survey results closer to the telephone survey results. This shows that an internet survey with propensity weighting model is a potential alternative survey method in the prediction of elections.

• Journal of Korea Society of Industrial Information Systems
• /
• v.18 no.3
• /
• pp.35-46
• /
• 2013

In order to develop an accurate analytical model for domestic electricity demand forecasting, we propose a prediction method of the electric power demand pattern by combining SMO classification techniques and a dimension reduction conceptualized subspace clustering techniques suitable for high-dimensional data cluster analysis. In terms of electricity demand pattern prediction, hourly electricity load patterns and the demographic and geographic characteristics can be analyzed by integrating the wireless load monitoring data as well as sub-regional unit of census information. There are composed of a total of 18 characteristics clusters in the prediction result for the sub-regional demand pattern by using census information and power load of Seoul metropolitan area. The power demand pattern prediction accuracy was approximately 85%.

• The Korean Journal of Applied Statistics
• /
• v.35 no.5
• /
• pp.619-629
• /
• 2022

The five major violent crimes including murder, robbery, rape·forced indecent act, theft, and violence are representative crimes that threaten the safety of members of society and occur frequently in real life. These crimes have negative effects such as lowering the quality of citizens' life. In the case of Seoul, the capital of Korea, the risk for the five major violent crimes is increasing because the population density of Seoul is increasing as a large number of people in the provinces move to Seoul. In this study, to reduce this risk, the relative risk for the occurrence of the five major violent crimes in Seoul is modeled using three spatio-temporal models. In addition, various risk factors are included to identify factors that significantly affect the relative risk of the five major violent crimes. The best model is selected in terms of the deviance information criterion, and the analysis results including various visualizations for the best model are provided. This study will help to establish efficient strategies to sustain people's safe everyday living by analyzing important risk factors affecting the risk of the five major violent crimes and the relative risk of each region.

• Journal of the Korea Convergence Society
• /
• v.9 no.9
• /
• pp.263-270
• /
• 2018

The purpose of this study is to investigate the correlation between the demographic characteristics of Korean men and the preference of women's grading such as age, education, marital status, occupation, monthly income, and residence. After the questionnaire distribution, 333 questionnaires were analyzed statistically. Through this study, we will investigate the preference of men according to the step length of women's graduation cuts, and contribute to the establishment of the most preferred type of graduation cuts. As a result of the questionnaire analysis, 51.1% of all males preferred the gradation type with a large step of the cut length, and it was found that there was a difference in the preference for the step according to demographic characteristics (p <0.05) It is possible to conduct various studies on the style of the graduation cut among the hairstyles of women who are visually preferred and beautiful. In addition, it will be possible to derive the importance of customer satisfaction in hair salons, and it will be a basic index for searching for changes in the gradation cuts that can be applied in various ways while maximizing the aesthetic image of women.

• Journal of the Korean association of regional geographers
• /
• v.7 no.3
• /
• pp.107-120
• /
• 2001

This study is concerned with providing a reliable procedure of calibrating a set of places specific distance parameters and with applying it to U.S. inter-State migration flows between 1985 and 1900. It attempts to conform to recent advances in quantitative geography that are characterized by an integration of ESDA(exploratory spatial data analysis) and local statistics. ESDA aims to detect the spatial clustering and heterogeneity by visualizing and exploring spatial patterns. A local statistic is defined as a statistically processed value given to each location as opposed to a global statistic that only captures an average trend across a whole study region. Whereas a global distance parameter estimates an averaged level of the friction of distance, place-specific distance parameters calibrate spatially varying effects of distance. It is presented that a poisson regression with an adequately specified design matrix yields a set of either origin-or destination-specific distance parameters. A case study demonstrates that the proposed model is a reliable device of measuring a spatial dimension of migration, and that place-specific distance parameters are spatially heterogeneous as well as spatially clustered.