• 대기
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• 제29권3호
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• pp.283-294
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• 2019

For the upper air observations, a temperature measurement using radiosonde is a common method, and the compensation of solar radiation effects in the radiosonde temperature sensor is an important factor. In this paper, we present various experiments and compensation methods of the radiosonde temperature sensor to overcome the errors caused by the movement of the radiosonde rotation, etc. The methods and procedures of this study are as follows. First, we used the solar simulator to analyze the temperature variation and solar effect of the temperature sensor in the radiosonde according to the insolation. We also analyzed the temperature variation and solar effect of the temperature sensor according to the incident angle between the solar simulator and radiosonde. Second, we measured and analyzed solar radiation absorbed by solar cells attached to radiosonde. Third, we present combined compensate solution of the first and the second experiment results, to overcome errors caused by insolation effects in the radiosonde temperature sensors. Fourth, we compared that the reference temperature in similar environment with the upper air conditions, to verify the new radiated compensation performance of the radiosonde temperature sensor. Finally, the radiosonde fabricated in this study was raised to the atmosphere, and the laser correction algorithm proposed through experiments was reviewed. As a result of the radiosonde SRS-10 produced in this study, the temperature deviation from Vaisala RS92 was $0.057^{\circ}C$ in nighttime observation, $0.17^{\circ}C$ in daytime observation, It is expected that the GRUAN under WMO will be able to obtain a high test rating of 5.0.

• 한국IT서비스학회지
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• 제17권4호
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• pp.101-117
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• 2018

Companies are responding appropriately to the rapidly changing business environment and striving to lead those changes. As part of that, we are meeting our strategic goals through IT projects, which increase the number of simultaneous projects and the importance of project portfolio management for successful project execution. It also strives for efficient deployment of human resources that have the greatest impact on project portfolio management. In the early stages of project portfolio management, it is very important to establish a reasonable manpower plan and allocate performance personnel. This problem is a problem that can not be solved by linear programming because it is calculated through the standard deviation of the input ratio of professional manpower considering the uniformity of load allocated to the input development manpower and the importance of each project. In this study, genetic algorithm, one of the heuristic methods, was applied to solve this problem. As the objective function, we used the proper input ratio of projects, the input rate of specialist manpower for important projects, and the equal load of workload by manpower. Constraints were not able to input duplicate manpower, Was used as a condition. We also developed a program for efficient application of genetic algorithms and confirmed the execution results. In addition, the parameters of the genetic algorithm were variously changed and repeated test results were selected through the independent sample t test to select optimal parameters, and the improvement effect of about 31.2% was confirmed.

• 한국정보통신학회논문지
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• 제23권4호
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• pp.394-400
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• 2019

잡음 제거는 디지털 영상처리 과정에서 필수적으로 이루어지며, 다양한 분야에서 그 목적과 환경에 맞는 알고리즘을 개발하기 위해 많은 연구가 진행되고 있다. 그러나 기존 임펄스 잡음 제거 방법들은 영상의 에지 성분 및 고주파 성분의 잡음 제거에 다소 미흡한 성능을 보이고 있다. 따라서 본 논문에서는 고주파 성분을 보존하기 위해 잡음 판단에 따른 잡음 밀도에 따라 마스크의 범위를 확장하였다. 선택된 마스크는 임펄스 잡음을 제외한 내부 화소의 메디안 값과 표준편차를 기준으로 화소 범위가 설정된다. 그리고 화소 범위에 존재하는 화소는 거리에 따른 가중치를 적용하여 최종 출력 계산에 사용하였다. 제안한 알고리즘은 기존 방법에 비해 영상의 에지 부분 및 고주파 성분이 많은 영역에서 잡음 제거성능이 우수하였으며, 시뮬레이션을 통해 성능을 비교하였다.

• 한국환경농학회지
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• 제39권4호
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• pp.368-374
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• 2020

BACKGROUND: The residual analysis of polar pesticides has remained a challenge. It is even more difficult to simultaneously analyze multiple polar pesticides. Diquat, paraquat, and chlormequat are typical examples of highly polar pesticides. The existing methods for the analysis of diquat, paraquat and chlormequat are complex and time consuming. Therefore, a simple, quick and effective method was developed in the represent study for simultaneous analysis of diquat, paraquat and chlormequat in animal products, meat and fat using UPLC-MS/MS. METHODS AND RESULTS: Sample extraction was carried out using acidified acetonitrile and water and re- extracted with acidified acetonitrile and combine the extracts followed by centrifugation. The extract was then cleaned up with a HLB cartridge after reconstitution with acidic acetonitrile and water. The method was validated in quintuplicate at three different concentrations. The limits of detection (LOD) and quantification (LOQ) were 0.0015 and 0.005 mg/L, respectively. Matrix suppression effect was observed for all of the analytes. A seven point matrix matched calibration curve was constructed for each of the compound resulted excellent linearity with determination coefficients (R2) ≥ 0.991. Accuracy and precision of the method was calculated from the recovery and repeatability and ranged from 62.4 to 119.7% with relative standard deviation less than 18.8%. CONCLUSION: The recovery and repeatability of the developed method were in the acceptable range according to the Codex Alimentarius guideline. The developed method can be applied for the routine monitoring of diquat, paraquat, and chlormequat in animal products, meat and fat.

• 한국정보통신학회논문지
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• 제25권1호
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• pp.75-80
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• 2021

측위 기술은 증강현실, 스마트 팩토리, 자율주행 등에서 중요한 기능을 수행하고 있다. 측위 기술 중에서 비콘을 이용한 측위 방법은 RSSI(Receiver Signal Strength Indicator) 값의 편차로 인하여 도전적인 과제로 여겨져 왔다. 본 논문에서는 수신기의 RSSI 값을 입력으로 하고 거리를 목표 값으로 하는 신경망을 학습시켜서 이동하는 객체에 대한 위치를 예측하였다. 이를 수행하기 위해 RSSI 대비 거리 실측값을 수집하였다. 수집한 데이터로 합성 데이터를 만들기 위한 신경망을 도입하였다. 이 신경망을 바탕으로 거리 대비 RSSI 값을 예측하였다. 합성 데이터를 바탕으로 가상으로 좌표계를 구성하여 객체의 위치를 예측하였다. 합성 데이터를 생성하기 위한 신경망으로 RSSI의 표준편차는 구하였고 이 값을 기반으로 가상환경에서 단말의 위치를 추적하는 신경망을 학습시켜 객체의 좌표를 추정하였다.

• 디지털융복합연구
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• 제19권3호
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• pp.13-24
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• 2021

본 연구는 대학생을 대상으로 복합적 문제해결능력을 갖춘 융합인재 양성을 위한 플립러닝을 활용한 글쓰기 프로그램의 효과를 알아보기 위한 단일군 전후설계의 원시실험연구이다. G도 C대학교 대학생 27명을 2020년 9월 1일부터 10월 30일까지 자료수집 하였다. IBM SPSS 25.0을 활용하여 빈도(백분율), 평균과 표준편차, paired t-test로 분석하였다. 셀프리더십은 평균 0.45점 향상(p<.001), 메타인지는 0.87점 향상(p<.001), 목표지향성은 0.77점 향상(p<.001), 창의성은 평균 0.51점(p<.001) 향상되어 통계적으로 유의하였다. 본 연구를 통해 플립러닝을 활용한 글쓰기가 복합적 문제해결능력 역량을 향상시키는 효과가 있었다. 이는 현 세대의 대학생들에게 복합적 문제해결능력을 갖춘 융합인재 양성을 위한 교육프로그램 개발에 기초자료로 활용되어 질 것으로 기대한다. 또한 온라인 환경이 자유로운 현 대학생들에게 플립러닝을 e-러닝으로 적용하는 다양한 수업 개발이 요구된다.

• International Journal of Knowledge Content Development & Technology
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• 제11권1호
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• pp.49-64
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• 2021

This research paper delved into the availability and utilization of library portal services for research in university libraries in Nigeria. Two research questions and two null hypotheses were formulated to guide the study. A structured questionnaire was used for data collection. The study was carried out in Nnamdi Azikiwe Library, University of Nigeria Nsukka (UNN) and Felix Aghagbo Nwako Library, Nnamdi Azikiwe University Library (UNIZIK), Awka. A total of 70 professionals (librarians and system analysts) in these libraries supplied data for the study. Data collected was analyzed using mean and standard deviation. These were used to answer the research questions while the null hypotheses were tested using t-test statistic at 0.05 level of significance and 68 degree of freedom. Major findings showed that portal services available in the library showed that the areas of availability of library portal services in Nnamdi Azikiwe Library, U.N.N. includes Agriculture, Health Sciences, Engineering, Environmental Sciences and information about institution, Social Sciences, Arts and Humanities, Natural Sciences. In Festus Aghagbo Nwako Library, Awka, the areas of Portal Library Services include Career Development, Federal Government Programs, Environmental Sciences, Biological Sciences, Social Sciences, Arts and Humanities, Engineering, and Health Sciences. Findings on extent of utilization of portal services available in the libraries indicated that portal services are utilized to a low extent in the university libraries. Furthermore, librarians did not significantly differ in their opinions on the availability of library portal services and on the extent of utilization of library portal services in the libraries under study. It is therefore recommended that provisions should be made by the universities and library management to provide and update required portal services in addition to creating enabling environment for enhanced access and utilization of these services. The governments must make an effort to provide funds for policy implementation, necessary technology training for librarians and users, and develop general information infrastructure.

• 여성건강간호학회지
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• 제27권4호
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• pp.286-296
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• 2021

Purpose: This study compared infant mortality and its associated factors between Korean and immigrant women using vital statistics gathered by Statistics Korea. Methods: Birth and death statistics from the period between 2009 and 2019 were extracted from the census of population dynamics data of the Microdata Integrated Service, Korea. Statistical data were derived from a complete survey and infant mortality was analyzed from mortality statistics data. Descriptive statistics were used for comparison. Results: The average infant mortality rate (IMR) of Korean women was 2.7 in Korea, which did not change significantly between 2009 and 2019; however, the IMR of immigrant women increased significantly in 2018 to 4.2 and subsequently decreased to 2.6 in 2019. Moreover, the age of Korean and immigrant women at the time of infant death gradually increased from 31.1 years and 25.9 years in 2009 to 32.8 years and 30.9 years in 2019, respectively. The gestational age was lower for deceased infants born to immigrant women (mean, 31.04 weeks; standard deviation [SD], 6.42; median, 30.00) compared to infants born to Korean women (mean, 31.71 weeks; SD, 6.48; median, 32.00). Immigrant women (91.7%) received slightly fewer antenatal care visits compared to Korean women (93.1%). Conclusion: It is vital to devise a plan to lower the IMR of immigrant women in Korea. Moreover, it is necessary to explore the factors related to infant mortality among immigrant women within the context of Korean societal situation, culture, and home environment.

• 한국ITS학회 논문지
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• 제21권2호
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• pp.74-84
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• 2022

자율주행 관련 기술의 고도화와 함께 자율차와 비자율차가 혼재된 교통 환경이 예측됨에 따라서 미시구간의 차량 속도정보 예측은 안전한 교통 환경 구축에 가장 중요한 정보 중 하나로 판단되고 있다. 하지만, 현재 제공되는 링크 기준 미시구간 주행 속도는 속도 변화 구간을 정확하게 반영하지 못하는 한계가 있다. 본 연구에서는 미시구간 속도정보 서비스를 위한 개별 차량 빅데이터 기반의 공간 분할 방안을 제시한다. 본 연구에서는 차량 빅데이터를 이용한 동질속도구간 도출과 지오해시 기반의 단계적 구간 분할을 통하여 미시적 속도 정보 변화 지점을 분류하였다. 경부고속도로 경기지역에 대하여 제안된 방법을 적용한 결과 해당 구간 도로는 130 및 170개의 동질속도구간으로 세분되었다. 본 연구에서는 결과 분석을 통하여 제안된 방법은 기존 링크 기반 정보에 비하여 정밀하고 정확한 속도 정보 제공이 가능함을 제시하였으며, 개별 차량 빅데이터를 이용한 미시적 속도 정보 제공을 위한 구간 세분화가 필요함을 검증하였다.

• Nuclear Engineering and Technology
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• 제54권6호
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• pp.2077-2083
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• 2022

In the unlikely event of core disruptive accident in sodium cooled fast reactors, the reactor containment building would be bottled up with sodium and fission product aerosols. The behavior of these aerosols is crucial to estimate the in-containment source term as a part of nuclear reactor safety analysis. In this work, the evolution of sodium aerosol characteristics (mass concentration and size) is simulated using HAARM-S code. The code is based on the method of moments to solve the integro-differential equation. The code is updated to FORTRAN-77 and run in Microsoft FORTRAN PowerStation 4.0 (on Desktop). The sodium aerosol characteristics simulated by HAARM-S code are compared with the measured values at Aerosol Test Facility. The maximum deviation between measured and simulated mass concentrations is 30% at initial period (up to 60 min) and around 50% in the later period. In addition, the influence of humidity on aerosol size growth for two different aerosol mass concentrations is studied. The measured and simulated growth factors of aerosol size (ratio of saturated size to initial size) are found to be matched at reasonable extent. Since sodium is highly reactive with atmospheric constituents, the aerosol growth factor depends on the hygroscopic growth, chemical transformation and density variations besides coagulation. Further, there is a scope for the improvement of the code to estimate the aerosol dynamics in confined environment.