Rejoinder: A Study on the Population Structure of Democratic People's Republic of Korea

Jeon, Saebom,Kim, Seong Eun,Park, Yousung The Korean Statistical Society 2015 Communications for statistical applications and me Vol.22 No.1

A Study on the Population Structure of Democratic People's Republic of Korea

Jeon, Saebom,Kim, Seong Eun,Park, Yousung The Korean Statistical Society 2015 Communications for statistical applications and me Vol.22 No.1

The re-unification of the two Koreas is seen as a potential solution to the aging problem and low fertility, along with the increase in the old population structure of the Republic of Korea. Population structure is an indicator of national competitiveness or growth, but little is known officially about the populations of Democratic People's Republic of Korea (DPRK). Understanding the population structure of the DPRK is important to prepare for re-unification and estimate the socio-economic costs of national welfare under a re-unified Korea. In this paper, we assess reliability of the two modern national censuses of DPRK and use the limited resources available to reconstruct the intercensal populations between these two censuses. Excess deaths from the 1995 famine are estimated at 489,972 to 574,306 and are close to the estimates of Goodkind et al. (2011) and the reconstructed populations in the of DPRK implies a big difference between two Koreas.

선거예측 개선을 위한 새로운 대체방법: 제19대 총선 출구조사를 중심으로

전새봄 ( Saebom Jeon ),박유성 ( Yousung Park ) 한국조사연구학회 2016 조사연구 Vol.17 No.3

출구조사 예측실패의 큰 원인 중 하나는 출구조사에서 발생하는 무응답이다. 이에 출구조사의 예측력을 개선하기 위하여, 무응답을 줄이기 위한 노력과동시에 무응답을 사후층화(post-stratification)하거나 대체(imputation)하는 등다양한 방법이 연구 및 적용되어 왔다. 그러나 무응답을 추정 및 대체하는방법은 무응답 메커니즘에 따라 다름에도 불구하고, 추정에 앞서 그 메커니즘을 식별하는 방법은 제한적으로 연구되어 왔다. 본 연구는 메커니즘에 대한식별이 불가하다고 알려진 우도기반 추정방법의 한계를 극복하고자, 새로운추정법인 적률추정법을 제안하고 있다. 또한 각 응답 메커니즘 하에서의 변방값 발생 특성 및 무응답 메커니즘의 정의를 이용하여 메커니즘을 식별하는방법을 제안하고 있다. 2012년 제19대 총선 출구조사 자료를 이용하여 실증분석한 결과, 무응답 메커니즘을 식별 및 대체한 예측결과가 기존의 조사기관예측결과 및 ML, 그리고 베이지안 방법보다 더 우수한 예측력을 보여, 본 연구방법에서 제안한 방법이 출구조사 선거예측 정확도를 개선시키고 있음을 확인할 수 있었다. One of the biggest causes of failure in exit poll prediction is nonresponses during exit polling. In this regard, there have been many efforts to reduce non-responses, and various researches and applications on imputation method including post-stratification. However, although these imputation methods depend on the missing mechanism, studies on the identification of mechanism prior to estimation are very limited. This research proposes a method of moment as a new estimation method to overcome the nonidentifiability of mechanism due to the same likelihood. Also, we suggest a way to identify the missing mechanism, using the definition of missing mechanism as well as the occurrence of boundary solution problem of moment estimates. From the empirical analysis of the exit polls of 19th general election in 2012, our method of moment imputation according to the identified missing mechanism shows better prediction than other methods including ML and Bayesian imputation. Therefore, our proposed imputation method can be a new alternative to improve the prediction accuracy of exit poll.

Stochastic Traffic Congestion Evaluation of Korean Highway Traffic Information System with Structural Changes

Yongwoong Lee,Saebom Jeon,Yousung Park 한국경영정보학회 2016 Asia Pacific Journal of Information Systems Vol.26 No.3

Stochastic Traffic Congestion Evaluation of Korean Highway Traffic Information System with Structural Changes

Lee, Yongwoong,Jeon, Saebom,Park, Yousung The Korea Society of Management Information System 2016 Asia Pacific Journal of Information Systems Vol.26 No.3

The stochastic phenomena of traffic network condition, such as traffic speed and density, are affected not only by exogenous traffic control but also by endogenous changes in service time during congestion. In this paper, we propose a mixed M/G/1 queuing model by introducing a condition-varying parameter of traffic congestion to reflect structural changes in the traffic network. We also develop congestion indices to evaluate network efficiency in terms of traffic flow and economic cost in traffic operating system using structure-changing queuing model, and perform scenario analysis according to various traffic network improvement policies. Empirical analysis using Korean highway traffic operating system shows that our suggested model better captures structural changes in the traffic queue. The scenario analysis also shows that occasional reversible lane operation during peak times can be more efficient and feasible than regular lane extension in Korea.

A sample size calibration approach for the p-value problem in huge samples

Park, Yousung,Jeon, Saebom,Kwon, Tae Yeon The Korean Statistical Society 2018 Communications for statistical applications and me Vol.25 No.5

The inclusion of covariates in the model often affects not only the estimates of meaningful variables of interest but also its statistical significance. Such gap between statistical and subject-matter significance is a critical issue in huge sample studies. A popular huge sample study, the sample cohort data from Korean National Health Insurance Service, showed such gap of significance in the inference for the effect of obesity on cause of mortality, requiring careful consideration. In this regard, this paper proposes a sample size calibration method based on a Monte Carlo t (or z)-test approach without Monte Carlo simulation, and also proposes a test procedure for subject-matter significance using this calibration method in order to complement the deflated p-value in the huge sample size. Our calibration method shows no subject-matter significance of the obesity paradox regardless of race, sex, and age groups, unlike traditional statistical suggestions based on p-values.

염분 변화에 따른 명태(Gadus Chalcogrammus)의 스트레스 반응; 혈액생리학적 변화 및 유전자 발현

전소희(So-Hee JEON),최진(Jin CHOI),김기태(Ki-Tae KIM),변순규(Soon-Gyu BYUN),임현정(Hyun-Jeong LIM),김이경(Lee-Kyung KIM),손새봄(Saebom SOHN) 한국수산해양교육학회 2022 水産海洋敎育硏究 Vol.34 No.6

출산율 예측모형을 이용한 한국의 출산력 시나리오 분석

김기환,전새봄,Kim, Keewhan,Jeon, Saebom 한국통계학회 2015 응용통계연구 Vol.28 No.4

한국의 지속적인 저출산은 세계적으로 유례가 없을 정도의 급격한 고령화 속도와 맞물려 국가경쟁력 및 사회보장 시스템을 약화시키는 요인이 되었다. 저출산 문제를 해결하기 위하여 정부에서는 각종 출산장려정책을 실시하고 있으나, 현재까지 저출산에서 벗어나지 못하고 있어 정책이 효과적이지 못하였던 것으로 평가된다. 그러므로 본 연구에서는 보다 효과적인 정책개발의 근간을 마련하기 위하여 조건부 순위별 출산율을 제안하고, 이를 이용하여 한국의 출산정책 효과를 파악하였다. 조건부 순위별 출산율을 사용하면 순위별 출산율을 사용하는 것보다 합계출산율의 변화와 효과를 명확히 산출할 수 있으므로, 다양한 순위별 출산율의 시나리오에 따라 합계출산율의 변화를 비교하였다. 이를 통하여 현재 정부의 셋째 아 출산지원 정책으로 도달할 수 있는 합계출산율 및 둘째 아 또는 첫째 아의 출산지원을 하였을 때 도달할 수 있는 합계출산율을 산출할 수 있었다. 또한 지속적인 저출산으로 빠르게 감소하고 있는 가임여성(15-49세)을 고려하여 합계출산율에 따른 출생아수를 함께 제시하여 실질적인 출생아수의 증가를 유도하는 정책개발에 도움이 될 수 있도록 연구결과를 정리하였다. The low fertility rate and the unprecedented rapid pace of population aging is a significant factor degrading the national competitiveness and the social security system of Korea. The government has implemented various maternity incentives to alleviate the low birth problem; however, the policy seems in effective to solve the problem of low fertility. This study proposes a conditional birth-order specific fertility rate and investigates the policy effects of fertility transition in Korea to provide a basis for more effective policy development. The use of a conditional birth-order specific fertility rate allows for an effective calculation of the change and the effect in total fertility rate than a birth-order specific fertility rate. We compare the effects of the total fertility rate according to various scenarios that enables us to calculate how the total fertility rate can achieve the current multi-child childbirth support policy of the government and estimate how the total fertility rate can be achieved when focusing on the first or second childbirth support policy. We also summarize the research results on policy development for a practical increase in the childbirth that considers the rapid decrease in women of childbearing age (15-49 years) due to continued low fertility and present the number of childbirths in accordance with the total fertility rate.

A Study on the Population Structure and Aging of Reunified Korea

Yousung Park(박유성),Saebom Jeon(전새봄) 서울대학교 사회발전연구소 2015 Journal of Asian Sociology Vol.44 No.3

The Republic of Korea is undergoing both unprecedented, rapid population aging and lowest-low fertility problems. These population trends eventually cause a population decline, manpower decrease, and other related socio-economic problems. Recently, reunification of the two Koreas has been discussed as a possible breakthrough to overcome population problems. This paper first conducts a population projection of the Democratic People’s Republic of Korea, and then predicts the future population of a reunified Korea under possible scenarios of fertility and mortality. We further examine the population structure of reunified Korea using age-specific populations, aging indices and dependency ratios to investigate population aging and the socio-economic sustainability of the reunified Korea. Based on the projection results, reunification cannot drastically change the aging trend of the Republic of Korea, but can delay the decrease of the working- age population.

Complete genome sequence of Bacillus subtilis BS16045 isolated from Gochujang

전새봄,허준,엄태붕,Jeon, SaeBom,Heo, Jun,Uhm, Tai-Boong The Microbiological Society of Korea 2017 미생물학회지 Vol.53 No.1

한국 발효식품의 보존성을 높이기 위한 스타터 균주를 얻기 위하여 고추장에서 Bacillus subtilis BS16045를 분리하였다. B. subtilis BS16045에 대한 유전체 분석을 실시하였으며, G+C 비율이 43.6%인 4,165,121 bp 크기의 염기서열을 얻었다. 또한 이 유전체로부터 항진균 및 항균 활성에 연관이 있는 surfactin, kanosamine, bacillaene, plipastatin, subtilosin A, bacilysin 생산 유전자들을 확인하였다. 이러한 결과들을 통해 B. subtilis BS16045는 장류 제조시설에서 유해균의 오염문제를 해결할 수 있는 스타터로 이용될 수 있을 것으로 보인다. Bacillus subtilis BS16045 was isolated from Gochujang, a Korean red chili paste, in order to get a starter strain that can be used for preservation of the fermented foods. We report the whole genome sequence of B. subtilis BS16045, which contains 4,165,121 bp with a G+C content of 43.6%. We also confirmed the set of antibiotic genes producing surfactin, kanosamine, bacillaene, plipastatin, subtilosin A, and bacilysin, which are related to antifungal and antibacterial activities. These results indicate that B. subtilis BS16045 could be a potential starter strain for solving contamination by food-borne pathogens in the soybean products factory.