• Korean Journal of Remote Sensing
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• v.36 no.6_1
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• pp.1339-1348
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• 2020

Phytoplankton controls marine ecosystems in terms of nutrients, photosynthetic rate, carbon cycle, etc. and the degree of its influence on the marine environment depends on their physical size. Many studies have been attempted to identify marine phytoplankton size classes using the remote sensing techniques. One of successful approach was the three-component model which estimates the chlorophyll concentrations of three phytoplankton size classes (micro-phytoplankton; >20 ㎛, nano-; 2-20 ㎛ and pico-; <2 ㎛) as a function of total chlorophyll. Here, we examined the applicability of Geostationary Ocean Colour Imager (GOCI) to the mapping of the phytoplankton size class distribution in the East Sea. A fit of the three-component model to a biomarker pigment dataset collected in the study area for some years including a large harmful algal bloom period has been carried out to derive size-fractioned chlorophyll concentration (CHL). The tuned three-component model was applied to the hourly GOCI images to identify the fractions of each phytoplankton size class for the entire CHL. Then, we investigated the distribution of phytoplankton community in terms of the size structure in the East Sea during the harmful Cochlodinium polykrikoides blooms in the summer of 2013.

• Journal of Aerospace System Engineering
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• v.12 no.5
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• pp.69-75
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• 2018

In this study, we proposed a nylon wire cutting-type solar panel separation mechanism for CubeSat applications using spring-loaded pogo-pins, which has been widely used as temporary electrical interface between two separate electronics. The mechanism proposed in this study has great advantages of higher holding capability, ability to constrain along in-plane and out-of-plane directions of solar panels, simplicity in tightening of nylon wire and synchronous separation of multiple panels. In addition, the pogo-pins used for the proposed mechanism act as electrical power interface, separation status switch and separation spring. In this study, the functionality of the proposed mechanism was validated through the separation tests with various number of nylon wire windings.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.44 no.9
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• pp.814-824
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• 2016

The mission objective of STEP Cube Lab. (Cube Laboratory for Space Technology Experimental Project) classified as a pico-class satellite is to find space core technologies researched at domestic industry or university and to verify these technologies on mission orbit. To implement this objective, system level electrical integration and function test (EIT) by using developed flight software were performed in compliance with system requirements. And the effectiveness of the flight model (FM) was verified through launch and thermal vacuum test at acceptance level. This paper will introduce a series of process of electrical function tests for FM EIT, launch and thermal vacuum tests.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.42 no.5
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• pp.430-436
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• 2014

The mission objective of STEP Cube Lab. (Cube Laboratory for Space Technology Experimental Project) classified as a pico-class satellite is to verify the technical effectiveness of payloads such as variable emittance radiator, SMA washer, oscillating heat pipe and MEMS based solid propellant thruster researched at domestic universities. In addition, the MEMS concentrating photovoltaic power system and the non-explosive holding and separation mechanism with the advantages of high constraint force and low shock level will be developed as the primary payloads for on-orbit verification. In this study, the feasibility of the mission actualization has been confirmed by the preliminary system design.