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        검색결과 26

        1.
        2023.10 구독 인증기관·개인회원 무료
        모기는 감염병을 매개하는 종으로 전염병 확산 억제를 위해서는 개체수의 감시와 정확한 예측이 필요하다. 본 연구에서는 모기 개체수 및 기상 및 현장 자료를 활용해 모기 개체수 머신러닝 모델을 개발하였다. 모기 개체수는 디지털 모기 측정기(Digital Mosquito Monitoring System, DMS)의 2015 년~2022년의 5월~10월의 자료를 활용하였다. 기상 자료는 기온, 강수량, 풍속, 습도를 사용하였으며, 현장 조사 자료는 현장을 명목척도와 서열척도로 나누어 기록하여, 명목 척도의 경우 원핫 인코딩으 로 변환해 수치화하여 사용하였다. 분석에 사용된 머신러닝 모델은 Artificial Neural Network, Random Forest, Gradient Boosting Machine, Support Vector Machine이며 성능지표로 R2, RMSE를 사용하였다. 연구 결과, Gradient Boosting 모델이 R2 0.4, RMSE 22.45로 가장 좋은 성능을 나타냈다. 현장 조사 자료 를 분석에 활용하였을 때 R2는 증가하였고, RMSE는 감소하였다. 본 연구 결과 모기 개체수에 현장 조사 자료가 예측 정확도를 향상시킬 수 있음을 확인하였다.
        4.
        2018.06 KCI 등재 SCOPUS 구독 인증기관 무료, 개인회원 유료
        We carry out a study of Sub-Millimeter Galaxies (SMGs) in the AKARI NEP-Deep field using the James Clerk Maxwell Telescope (JCMT) SCUBA-2 850 μm source catalog, released as part of the SCUBA-2 Cosmology Legacy Survey (S2CLS) program. The SCUBA-2 850 μm map has a root mean square (rms) noise of 1.2 mJy beam−1 and covers an area of 0.60 degree2. We find four SMGs which have counterparts to Herschel sources with spectroscopic redshifts in the literature. In addition, three dust obscured galaxies (DOGs) detected in Herschel bands are selected as a comparison sample. We derive IR luminosities of SMGs using the CIGALE code, which are similar to those of high redshift SMGs from previous studies. The contribution of AGN to the total IR luminosity in SMGs (2%–11%) is smaller than the lower limit for the one in DOGs (19%–35%), which is consistent with the expectation from the evolutionary scenario of massive galaxies. We search for SMGs in overdense regions as protocluster candidates and investigate four regions, including candidates around three DOGs. Finally, we argue that follow-up spectroscopic observation for the NEP-Deep field will provide crucial information to understand the role of SMGs in the evolution of massive galaxies.
        4,800원
        5.
        2018.05 구독 인증기관·개인회원 무료
        Roads in Korea are equipped with PMS (Pavement Management System) computation data that runs on highway, national highway and municipal road. PMS is a program that selects and manages the road pavement optimal maintenance alternative as a indicator of the road pavement structural and functional performance. PMS is a system that has been developed for the primary purpose of maintaining the structural performance of road pavement, and so far does not include any indicators associated with the safety of road users. However, the road cave-in, which have recently become an issue on social networking sites, mass-media, and other issues, should pose systematically because it can make a safety risk to road users, and in particular lead to the structural and functional failure of the PMS program in view of the road pavement. Accordingly, this research has developed a practical use case for developing an integrated road cave-in management program based on the results of various studies on the exploration, analysis, assessment and handling of the existing road cave-in in Korea.
        11.
        2017.02 KCI 등재 SCOPUS 구독 인증기관 무료, 개인회원 유료
        We carry out the study of 850 μm sources in a part of the XMM-LSS field. The 850 μm imaging data were obtained by the SCUBA-2 on the James Clerk Maxwell Telescope (JCMT) for three days in July 2015 with an integration time of 6.1 hours, covering a circular area with a radius of 15′. We choose the central area up to a radius of 9.′15 for the study, where the noise distribution is relatively uniform. The root mean square (rms) noise at the center is 2.7 mJy. We identify 17 sources with S/N > 3.5. Differential number count is estimated in flux range between 3.5 and 9.0 mJy after applying various corrections derived by imaging simulations, which is consistent with previous studies. For detailed study on the individual sources, we select three sources with more reliable measurements (S/N > 4.5), and construct their spectral energy distributions (SEDs) from optical to far-infrared band. Redshift distribution of the sources ranges from 0.36 to 3.28, and their physical parameters are extracted using MAGPHYS model, which yield infrared luminosity LIR = 1011.3−1013.4 L⊙, star formation rate SFR = 101.3−103.2 M⊙yr−1 and dust temperature TD = 30−53 K. We investigate the correlation between LIR and TD, which appears to be consistent with previous studies.
        4,600원
        12.
        2016.10 KCI 등재 SCOPUS 구독 인증기관 무료, 개인회원 유료
        We present an optical imaging survey of AKARI Deep Field South (ADF-S) using the Korea Microlensing Telescope Network (KMTNet), to find optical counterparts of dusty star-forming galaxies. The ADF-S is a deep far-infrared imaging survey region with AKARI covering around 12 deg2, where the deep optical imaging data are not yet available. By utilizing the wide-field capability of the KMTNet telescopes (∼4 deg2), we obtain optical images in B, R and I bands for three regions. The target depth of images in B, R and I bands is 24 mag (AB) at 5, which enables us to detect most dusty star-forming galaxies discovered by AKARI in the ADF-S. Those optical datasets will be helpful to constrain optical spectral energy distributions as well as to identify rare types of dusty star-forming galaxies such as dustobscured galaxy, sub-millimeter galaxy at high redshift.
        4,000원
        20.
        2010.03 KCI 등재 구독 인증기관 무료, 개인회원 유료
        The purpose of this study is to investigate the effects of group exer˗ cise program on depression in the elders with dementia. Subjects of this research were selected from the patients of Hyoja hospital(Yong˗ in, Korea). They were elders with dementia having minor to moderate degrees of cognitive function. Twenty-four subjects were randomly assigned into two groups, each with 12 people; exercise group and the control group. The control group only performed general physio˗ therapy, while the exercise group performed exercise program and general physiotherapy for 8 weeks. Depression of the exercise group and the control group were measured at baseline before the study, at 4 weeks, and at 8 weeks after the study. Depression was measured by Geriatric Depression Scale Short Form Korea Version(GDSSF-K). Firstly, when comparing the levels of depression within the same group, depression was significantly lower in the exercise group, after the group exercise program. However, depression of the control group did not show significant changes before or after the study. Secondly, when comparing the levels of depression of the control group and the exercise group, differences between the levels meas˗ ured before the study and 8 weeks after the study, was a statistically significant decrease of depression. Thirdly, effects of group exercise program according to the applied period were analyzed showing 8 weeks of group exercise to be more beneficial than 4 weeks. People who performed continuous group exercise program showed decrease in depression compared to the absence of group exercise program. This can infer beneficial effects of group exercise program. Group exercise program had desirable influence on decreasing the level of depression.
        4,000원
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