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기상특보 발령과 해양폐기물 처리량의 연관성 분석을 통한 해양폐기물처리량의 추정
박기연,이종수,김도완,박순호,배재근 한국환경정책학회 2023 環境政策 Vol.31 No.1
본 연구에서는 국가기상특보 발령현황과 해양폐기물 처리량과의 관계를 규명하고, 두 인자의 상관관계를 이용하여 국가 기상특보 발령현황 예측 결과에 따라 해양폐기물 발생량을 예측하였다. 국가기상특보 발령현황과 해양폐기물 처리량과의 연관성을 알아보기 위해 선형회귀법을 사용하였으며. 두 데이터 사이의 기본 단위가 결정하였다. “예측. ETS” 기능과 기본단위를 이용하여 2021년부터 2030년까지 국가기상특보 발령현황과 해양폐기물 처리량을 예측하였다. 연도별로 약간의 변동성은 있으나, 두 인자가 서로 연관되어 있어 서로의 기본단위로 계산하였을 때 해양폐기물의 처리량은 64.5톤/건으로 나타났다. 2021년부터 2030년까지 국가기상특보 발령현황과 해양폐기물 처리량 예측 결과는 꾸준히 증가하고 있다. 본 연구의 결과는 미래 기상재해 및 해양폐기물에 대한 정부의 대비를 위한 기초자료로 활용될 수 있을 것이다.
박기연,염승용,김홍래,장영근 한국항공우주학회 2015 한국항공우주학회 학술발표회 논문집 Vol.2015 No.11
위성의 개발 초기단계에서 사용자의 요구사항을 맞추고 개발방향을 정립하기 위해 임무를 설계하고 분석하는 과정과 위성시스템의 개념설계를 수행하는 과정을 반복하게 된다. 이러한 반복적인 과정에서 많은 시간과 비용을 소요하게 된다. GUI(Graphical User Interface) 기반의 소프트웨어인 SCDT (Spacecraft Conceptual Design Tool)를 사용함으로써 개발 초기단계에서 소요되는 시간과 비용을 현저하게 줄일 수 있다. GUI 기반의 소프트웨어는 입력된 값들의 수정이 용이하고 다양한 방법으로 사용자에게 결과를 보여줄 수 있다. 본 논문에서는 MATLAB GUI 기반의 SCDT를 개발한 과정 및 개발된 SCDT GUI를 소개한다. The development of high performance satellite requires considerable time and cost in early phase, in particular, during the development of mission and system requirements through iterations of conceptual design and mission design. The Spacecraft Conceptual Design Tool(SCDT), based on Graphical User Interface(GUI), was developed to reduce the time and cost for early phase development. Furthermore, GUI-based software can make the input values to be editable easily and show users design results in various way. In this paper, the development results of MATLAB GUI-based SCDT are introduced.
박기연,김원석,곽인실 한국해양과학기술원 2019 Ocean science journal Vol.54 No.4
The ecdysone receptor (EcR) induces hormonal pathways by binding ecdysteroids to other nuclear receptors for development, reproduction, and molting processes. To further understand the role of EcR in polluted environments, we characterized EcR and assessed the transcriptional responses of the EcR gene to osmotic stress, and to endocrine disrupting chemicals (EDCs) such as bisphenol A (BPA) and di-(2-ethylhexyl) phthalate (DEHP) in the intertidal mud crab Macrophthalmus japonicus. Phylogenetic analysis showed that the ligand binding domain of M. japonicus EcR formed two different clusters among crab species. Osmotic stress prompted different expression patterns of EcR mRNA in M. japonicus crabs under low and high salinities. BPA exposure induced significant up-regulation of EcR as early as day 1 in M. japonicus gills and hepatopancreas. However, the expression levels of EcR returned to similar, or lower, levels as controls, by days 4 and 7. In contrast, EcR mRNA expression was significantly induced in M. japonicus gills and hepatopancreas exposed to most of the DEHP concentrations over all exposure times. Hepatopancreatic tissue is more sensitive than gill tissue in terms of EcR gene responses to EDCs. Taken together, these results suggest that the role of EcR in endocrine protection may involve different processes according to the type of EDCs and up-regulatory responses of the EcR transcript could be used as an indicator for detecting changes in hormonal systems caused by environmental stressors.
대수 오차방정식 외란관측기를 이용한 직렬탄성 액추에이터의 강인제어
박기연,박승규,윤태성,곽군평 제어·로봇·시스템학회 2019 제어·로봇·시스템학회 논문지 Vol.25 No.1
Muscle-strengthening robots have been developed in various ways and are used in military applications and recently in medical applications. The ball-screw-type series elastic actuator (SEA) as an actuator used in a muscle-strengthening robot is considerably advantageous in terms of cost because force sensors and harmonic gears can be replaced by variable resistors and ball screws. In this paper, we propose a new disturbance observer (DOB) for robust performance against a disturbance in the control of the ball-screw-type SEA with a ball screw, and show its performance by applying it to an SEA developed using a 3D printer. The proposed DOB had no difficulty in the design of a low-frequency filter as compared to the existing frequency domain DOB, and had the merit that the observer order was less than the state-space-design DOB and was easy to implement.
박기연,곽인실 한국해양과학기술원 2012 Ocean science journal Vol.47 No.4
The objective of this study was conducted to identify the possibility of using Chironomus metallothionein (MT) and vitellogenin (VTG) as biomarkers of stress caused by endocrinedisrupting chemicals (EDCs), heavy metals, herbicides and veterinary antibiotics. We characterized the MT and VTG cDNA in Chironomus riparius and evaluated their mRNA expression profiles following exposure to different environmental pollutants. The gene expression analysis showed that the MT mRNA levels increased significantly after long-term exposure to cadmium (Cd), copper (Cu), Lead (Pb), di(2-ethylhexyl) phthalate (DEHP), and 2,4-dichlorophenoxyacetic acid (2,4-D). Moreover, the VTG mRNA expression increased significantly in C. riparius larvae exposed to BPA, NP, DEHP, Cd, 2,4-D and fenbendazole. Evaluation of the long-term effects of environmental pollutants revealed up regulation of Chironomus MT mRNA in response to DEHP exposure among EDCs, and the level of the VTG mRNA was increased significantly following treatment with Cd and herbicide 2,4-D at all concentrations in a dose-dependent manner. These results indicate that VTG could be used as a potential biomarker of herbicide and Cd as well as EDCs, while MT was a potential biomarker of heavy metals such as Cd, Cu, and Pb in aquatic environments.
박기연,곽인실 한국해양과학기술원 2013 Ocean science journal Vol.48 No.2
The Asian paddle crab, Charybdis japonica, is a potential bio-indicator reflecting marine sediment toxicity as well as a commercially important species living along coastal areas in Korea. This study investigated its stress response by looking at the heat shock protein (HSP70) gene of C. japonica when the organism is exposed to bisphenol A (BPA) and 4-nonylphenol (NP). We characterized partial sequence of HSP70 as the stressresponse gene of C. japonica. The nucleotide sequence of C. japonica HSP70 is over 90% homologous with the corresponding gene of other crabs. Phylogenetic tree analysis revealed a close relationship between C. japonica HSP70 and HSP70 in other species of lobster and shrimps. HSP70 mRNA transcripts were detected in all the examined tissues of C. japonica, with the highest level in gills, the organ that most frequently came into contact with the external BPA or NP-laden water. As no reference data were available for C. japonica crab exposure, the BPA and NP 24-h LC50 values have not been previously determined. The expression of the C. japonica HSP70 gene to various BPA or NP concentrations during short and longer times was assessed. Gene expression was significantly induced in concentration- and time-dependent manners after BPA or NP exposures. These results support the postulation that crab C. japonica HSP70 could be a potential stress response molecular marker to monitor marine ecosystems.