시스템 다이내믹스의 정책지렛대를 활용한 RTE 핵심성공요인 도출에 관한 연구

정재운,김현수,최형림,홍순구 한국시스템다이내믹스학회 2007 한국시스템다이내믹스학회 춘계학술대회 발표논문집 Vol.2007 No.-

본 연구는 실시간 기업(Real-Time Enterprise:RTE)의 핵심성공요인(Critical Success Factor: CSF)을 도출에 관한 내용으로써 기존에 연구되었던 ``시스템 사고로 분석한 RTE 주요성공요인``의 연구 방법론을 개선하기 위해 동일주제로 연구되었다. 본 연구에서 도출된 성공요인의 결과를 기본 연구와 비교하였을 때 기존보다 크게 개선된 바는 없지만, 연구방법론 측면에서 시스템 다이내믹스의 정책지렛대라는 문제해결 방안도출 방법론을 활용함으로써 기존보다 객관화된 요인 도출과정을 설명할 수 있었다. 본 연구는 기존에 연구되었던 정재운 외(2006)의 ``시스템 사고로 분석한 RTE 주요성공요인``의 내용을 개선하기 위한 것으로써 기존 연구의 내용 및 내용 전개방식의 상당부분을 별도의 표기 없이 참조하고 있음을 서두에 밝혀둔다.

Event Mean Concentrations (EMCs) and First Flush Characteristics of Runoff from a Public Park in Korea

정재운,박하나,윤광식,최동호,임병진 한국응용생명화학회 2013 Applied Biological Chemistry (Appl Biol Chem) Vol.56 No.5

Characteristics of non-point source (NPS) pollution runoff from a public park in Gwangju, Korea were investigated. Results exhibited the highest pollutant concentrations at the start of the rainfall events due to their build-up and wash off processes. The average event mean concentrations (EMCs) were 27.8, 7.2,56.3, 7.5, and 0.84 mg/L (range: 4.2-54.8 mg/L) for COD, (0.5-20.8 mg/L) for TOC, (22.3-138.4) for SS, (1.4-18.5 mg/L) for TN,and (0.17-2.02 mg/L) for T-P, respectively. The study site presented a strong first flush effect for most rainfall events. However, no first flush effect was observed in rainfall events with small rainfall factors (e.g. intensity, amount, and runoff depth). On the other hand, the ratios of total pollution loads discharged by the first 20% of runoff volume were 32% for COD, 34% for TOC,36% for SS, 42% for T-N, and 50% for T-P. Especially, MFF20(mass first flush) values of T-N and T-P were larger than those of other pollutants (COD, TOC, SS), indicating that T-N and T-P are easily transported by stormwater runoff from the public park. First flush management of T-N and T-P, therefore, is required for efficient water quality management of the public park.

신앙미담 / 믿음의 선한 싸홈(1)

정재운 기독교대한성결교회 활천사 1932 활천 Vol.110 No.-

블록 트레인 서비스 운영 전략 학습 시뮬레이터 개발

정재운,김현수 한국디지털정책학회 2012 디지털융복합연구 Vol.10 No.11

Short-term Predictive Models for Influenza-like Illness in Korea:Using Weekly ILI Surveillance Data and Web Search Queries

정재운 한국디지털정책학회 2018 디지털융복합연구 Vol.16 No.9

Since Google launched a prediction service for influenza-like illness(ILI), studies on ILI prediction based on web search data have proliferated worldwide. In this regard, this study aims to build short-term predictive models for ILI in Korea using ILI and web search data and measure the performance of the said models. In these proposed ILI predictive models specific to Korea, ILI surveillance data of Korea CDC and Korean web search data of Google and Naver were used along with the ARIMA model. Model 1 used only ILI data. Models 2 and 3 added Google and Naver search data to the data of Model 1, respectively. Model 4 included a common query used in Models 2 and 3 in addition to the data used in Model 1. In the training period, the goodness of fit of all predictive models was higher than 95% (R2). In predictive periods 1 and 2, Model 1 yielded the best predictions (99.98% and 96.94%, respectively). Models 3(a), 4(b), and 4(c) achieved stable predictability higher than 90% in all predictive periods, but their performances were not better than that of Model 1. The proposed models that yielded accurate and stable predictions can be applied to early warning systems for the influenza pandemic in Korea, with supplementary studies on improving their performance.

새만금유역의 배출부하 특성

정재운,장정렬,최강원,임병진,이영재,강재홍,박혜린,조소현,Jung, Jae-Woon,Jang, Jeong-Ryeol,Choi, Kang-Won,Lim, Byung-Jin,Lee, Young-Jae,Kang, Jae-Hong,Park, Hye-Lin,Cho, So-Hyun 한국관개배수위원회 2010 한국관개배수논문집 Vol.17 No.2

For efficient water quality management of Saemangeum lake, it is very important to accurately analyze discharged load characteristics using investigated pollution sources data from Saemangeum watershed. Investigation of pollution sources was conducted from 2003 to 2007. In this study, pollution sources are largely classified into human population, livestock, industry, and land use. Discharged loads of BOD, T-N and T-P from classified pollution sources were calculated by Korea TMDL (Total Maximum Daily Load) technical guideline. The calculated results showed that the major sources of BOD and T-N were land use, human population, livestock, and industry in order. However, the major sources of T-P were livestock, land use, human population, and industry in order. Our results clearly show that pollution sources of the priority management for water quality enhancement in the Saemangeum lake has represented land use and livestock.

비가림 조건에서 시비에 대한 논담수 중 총질소 및 총인 농도 반응

정재운,최우정,윤광식,김한용,곽진협,임상선,장남익,허유정,Jung, Jae-Woon,Choi, Woo-Jung,Yoon, Kwang-Sik,Kim, Han-Yong,Kwak, Jin-Hyeob,Lim, Sang-Sun,Chang, Nam-Ik,Huh, Yu-Jeong 한국관개배수위원회 2007 한국관개배수논문집 Vol.14 No.1

Temporal changes in total nitrogen (T-N) and phosphorus (T-P) concentrations in paddy floodwater in response to fertilization under rain-shielding pot and small-scaled field conditions were investigated. On the basis of the changing patterns, suggestions for the use of fertilization factors, such as days after fertilization, in developing models for the estimation of T-N and T-P loads from paddy fields were made. Total N concentration was susceptible to fertilization, showing a peak concentration right after fertilization followed by a decreasing pattern with the elapse of days after fertilization. The decreasing pattern of T-N concentration followed the first- order kinetics, indicating that the models are likely to be an exponential equation using days after fertilization as an independent variable. Comparison between the pot and field experiments conducted with soils different in soil fertility revealed that indigenous soil N concentration significantly affected T-N concentration, and this suggests that soil N status can be used as the second variable for the models. Meanwhile, temporal changes in T-P concentration did not respond to P fertilization as sensitively as T-N. In combination with other published results, our study suggests that rainfall intensity and other factors associated with farming activities that are likely to cause disturbance of soil particles containing P may be used as possible variables for the models.

Application of Google Search Queries for Predicting the Unemployment Rate for Koreans in Their 30s and 40s

정재운,황진호 한국디지털정책학회 2019 디지털융복합연구 Vol.17 No.9

Prolonged recession has caused the youth unemployment rate in Korea to remain at a high level of approximately 10% for years. Recently, the number of unemployed Koreans in their 30s and 40s has shown an upward trend. To expand the government’s employment promotion and unemployment benefits from youth-centered policies to diverse age groups, including people in their 30s and 40s, prediction models for different age groups are required. Thus, we aimed to develop unemployment prediction models for specific age groups (30s and 40s) using available unemployment rates provided by Statistics Korea and Google search queries related to them. We first estimated multiple linear regressions (Model 1) using seasonal autoregressive integrated moving average approach with relevant unemployment rates. Then, we introduced Google search queries to obtain improved models (Model 2). For both groups, consequently, Model 2 additionally using web queries outperformed Model 1 during training and predictive periods. This result indicates that a web search query is still significant to improve the unemployment predictive models for Koreans. For practical application, this study needs to be furthered but will contribute to obtaining age-wise unemployment predictions.

만경강유역에서의 HSPF 모형의 보정

정재운,장정렬,정지연,최강원,임병진,김상돈,김갑순,윤광식,Jung, Jae-Woon,Jang, Jeong-Ryeol,Jung, Ji-Yeon,Choi, Kang-Won,Lim, Byung-Jin,Kim, Sang-Don,Kim, Kap-Soon,Yoon, Kwang-Sik 한국관개배수위원회 2011 한국관개배수논문집 Vol.18 No.1

The HSPF (Hydrological Simulation Program-Fortran) model was applied to Mangyeong river watershed to examine its applicability through calibration using monitoring data. For the model application, digital maps were constructed for watershed boundary, land-use, Digital Elevation Model of Mangyeong river watershed using BASINS (Better Assessment Science for Intergrating point and Nonpoint Sources) program. The observed runoff was 1976.4mm while the simulated runoff was 1913.4mm from 2007 to 2008. The model results showed that the simulated runoff was in a good agreement with the observed data and indicated reasonable applicability of the model. In terms of water quality, trends of the observed value were in a good agreement with simulated value despite its model performance lower than expected. However, its reliability and performance were with the expectation considering complexity of the watershed, pollutant sources and land use intermixed in the watershed. Overall, we identified application of HSPF model as reliable evidence by model performance.

인터넷 검색어를 활용한 실업률 예측

정재운,황성원,권치명 한국경영과학회 2015 한국경영과학회 학술대회논문집 Vol.2015 No.4

It is well-known that the unemployment issue is not just limited to the personal economic activity so all countries of the world spend efforts to reduce unemployment rates. However, any policy against the endemic issue, which varied from month to month by various factors, has difficulty for showing the expected effects in a short time because of delays inherent in the existing survey mechanism that it takes a long time to survey un/employment data as well as to develop their proper countermeasures. Depending on countries, the time required to collect the data ‘unemployment rate’ is various from month to quarter and even year. If each government can save time to monitor the critical data, faster and more accurate strategies will be presented for solving unemployment and related social issues like tax, crime, etc. On this account, recently an advanced analytics utilizing internet queries is suggested. This research uses an ARIMA model for forecasting a fluctuation of the unemployment rate specific in Korea and utilizes the information of keyword queries provided from the Naver(Korean representative portal site) trend for better prediction on unemployment rate of Korea.