• Research in Plant Disease
• /
• v.29 no.4
• /
• pp.399-404
• /
• 2023

Agricultural activities and the number of farms in the subarctic regions have been increasing annually after the coronavirus disease 2019 pandemic to achieve food self-sufficiency. Potatoes are vulnerable to soft rot bacteria at all stages of production, storage, and transportation. A novel bacterium, Pseudomonas sp. N3-W, isolated from Alaska tundra soil, grows at 5-25℃ and produces extracellular protease(s). N3-W caused necrotic spots (hypersensitivity) in hot pepper leaves and soft rot disease (pathogenicity) in potato tubers. The psychrotolerant N3-W caused significant soft rot symptoms on potatoes at a broad temperature range (5℃, 15℃, and 25℃). In contrast, mesophilic Pectobacterium carotovorum KACC 16999 induced severe rotting symptoms in potatoes at their optimal growth temperature of 15℃ and 25℃. However, it barely produced symptoms at 5℃, which is the appropriate storage and transportation temperature for potatoes. The results of pathogenicity testing imply that psychrotolerant soft rot pathogens from polar regions may cause severe soft rot not only during the crop growing season but also during storage and transportation. Our study indicates the possibility of new plant pathogen emergence and transmission due to the expansion of crop cultivation areas caused by permafrost thawing in response to recent polar warming.

• Journal of the Institute of Electronics Engineers of Korea SP
• /
• v.47 no.1
• /
• pp.44-52
• /
• 2010

In this paper, we propose a novel method for face recognition which uses polar coordinate instead of conventional cartesian coordinate. Among the central area of a face, we select a point as a pole and make a polar image of a face by evenly sampling pixels in each direction of 360 degrees around the pole. By applying conventional feature extraction methods to the polar image, the recognition rates are improved. The polar coordinate delineates near-pole area more vividly than the area far from the pole. In a face, important regions such as eyes, nose and mouth are concentrated on the central part of a face. Therefore, the polar coordinate of a face image can achieve more vivid representation of important facial regions compared to the conventional cartesian coordinate. The proposed polar coordinate transform was applied to Yale and FRGC databases and LDA and NLDA were used to extract features afterwards. The experimental results show that the proposed method performs better than the conventional cartesian images.

• Korean Journal of Remote Sensing
• /
• v.34 no.4
• /
• pp.649-659
• /
• 2018

The aim of this study is to develop a protocol for obtaining spectral signals that are robust to varying lighting conditions, which are often found in the Polar regions, for creating a spectral library specific to those regions. Because hyperspectral image (HSI)-derived spectra are collected on the same scale as images, they can be directly associated with image data. However, it is challenging to find precise and robust spectra that can be used for a spectral library from images taken under different lighting conditions. Hence, this study proposes a new radiometric calibration protocol that incorporates radiometric targets with a traditional vicarious calibration approach to solve issues in image-based spectrum measurements. HSIs obtained by the proposed method under different illumination levels are visually uniform and do not include any artifacts such as stripes or random noise. The extracted spectra capture spectral characteristics such as reflectance curve shapes and absorption features better than those that have not been calibrated. The results are also validated quantitatively. The calibrated spectra are shown to be very robust to varying lighting conditions and hence are suitable for a spectral library specific to the Polar regions.

• Atmosphere
• /
• v.26 no.2
• /
• pp.277-288
• /
• 2016

Polar lows are intense mesoscale cyclones that mainly occur over the sea in polar regions. Owing to their small spatial scale of a diameter less than 1000 km, simulating polar lows is a challenging task. At King Sejong station in West Antartica, polar lows are often observed. Despite the recent significant climatic changes observed over West Antarctica, adequate validation of regional simulations of extreme weather events such as polar lows are rare for this region. To address this gap, simulation results from a recent version of the Polar Weather Research and Forecasting model (Polar WRF) covering Antartic Peninsula at a high horizontal resolution of 3 km are validated against near-surface meteorological observations. We selected a case of high wind speed event on 7 January 2013 recorded at Automatic Meteorological Observation Station (AMOS) in King Sejong station, Antarctica. It is revealed by in situ observations, numerical weather prediction, and reanalysis fields that the synoptic and mesoscale environment of the strong wind event was due to the passage of a strong mesoscale polar low of center pressure 950 hPa. Verifying model results from 3 km grid resolution simulation against AMOS observation showed that high skill in simulating wind speed and surface pressure with a bias of $-1.1m\;s^{-1}$ and -1.2 hPa, respectively. Our evaluation suggests that the Polar WRF can be used as a useful dynamic downscaling tool for the simulation of Antartic weather systems and the near-surface meteorological instruments installed in King Sejong station can provide invaluable data for polar low studies over West Antartica.

• Proceedings of the Korean Society of Surveying, Geodesy, Photogrammetry, and Cartography Conference
• /
• 2009.04a
• /
• pp.95-100
• /
• 2009

Global warming melts polar ice, changes ocean currents, creates variation of local climate, and inundates low-altitude regions resulting in disasters to mankind. Accordingly, developed countries including U.S.A. and U.K. spend great amounts of efforts and money to plan and manage research activities on polar ice which is regarded as a key indicator of climate change. The proposed research aims to provide basic information for chasing and monitoring the melting phenomena of polar ice through multiple GPS to enhance the GPS quality.

• Animal Systematics, Evolution and Diversity
• /
• v.28 no.2
• /
• pp.84-96
• /
• 2012

Some gorgonians in the families, Primnoidae and Isididae within the suborder Calcaxonia were collected from subtidal zones between depths of 10 and 45 m in the coastal regions of King Sejong Station ($62^{\circ}13'S$, $058^{\circ}47'W$), Korea Polar Research Institute of Korea Ocean Research and Development Institute (KORDI) by SCUBA diving from 2009 to 2011. Three species in the Primnoidae, $Arntzia$ $gracilis$ (Molander, 1929), $Thouarella$ ($Thouarella$) $antarctica$ (Valenciennes, 1846) and $Onogorgia$ $nodosa$ (Molander, 1929), and also one species in the family Isididae, $Tenuisis$ $microspiculata$ (Molander, 1929) are newly recorded to octocorallian fauna in Marian Cove and Potter Cove of King George Island. These four species have been described in detail.

• Ocean and Polar Research
• /
• v.25 no.4
• /
• pp.617-623
• /
• 2003

Organisms living in the Arctic and Antarctic regions are exposed to strong constraints, of which temperature is a driving factor. Evolution has led to special adaptations, some with important implications at the biochemical, physiological, and molecular levels. The northern and southern polar oceans have very different characteristics. Tectonic and oceanographic events have played a key role in delimiting the two polar ecosystems and influencing evolution. Antarctica has been isolated and cold longer than the Arctic; its ice sheet developed at least 10 million years earlier. As an intermediate system, the Arctic is a connection between the more extreme, simpler Antarctic system and the very complex temperate and tropical systems. By studying the molecular bases of cold adaptation in polar fish, and taking advantage of the information available on hemoglobin structure and function, we analysed the evolutionary history of the ${\alpha}\;and\;{\beta}globins$ of Antarctic and Arctic hemoglobin using the molecular clock hypothesis as a basis for reconstructing the phylogenetic relationships among species.

• Korean Journal of Remote Sensing
• /
• v.34 no.6_2
• /
• pp.1203-1213
• /
• 2018

In Arctic and Antarctic ocean, remote sensing is the most effective observation for environmental changes due to the inaccessibility of the regions. Even though satellite, UAV (Unmanned Aerial Vehical) are well known remote sensing platforms, and research vessel also used for automatic measurement on the regions, varied environment of Polar regions require time series and wide coverage of data. Especially, in high latitude, apply an optical satellite remote sensing is not easy due to low sun altitude. In this paper, we introduce an operation of hyper-spectrometer (HyperSAS/Satlantic inc.) which is mounted on Ice Breaker Research Vessel ARAON of Korea Polar Research Institute since 2010, to acquire an above water reflectance atomatically through every research cruise on Arctic and Antarctic ocean and transit both regions. In addition to, auxiliary data for the remotely acquired data, in situ water sampling were also obtained. The above water reflectance and in situ water sampling data are continuously acquired since 2010 will contribute to improve an Ocean Color algorithm in the high latitude and help to understand ocean reflectances over from high latitude through low latitude. Preliminary result from above water reflectance showed characteristics of Arctic ocean and Antarctic Ocean and used to develop algorithms for estimating various ocean factors such as chlorophyll and suspended sediment.

• Journal of Astronomy and Space Sciences
• /
• v.18 no.1
• /
• pp.21-26
• /
• 2001

As part of a long-term program for polar upper atmospheric studies, temperatures and intensities of the OH(3-1) bands were derived from spectrometric observations of airglow emissions over King Sejong station($62.22^{circ}S,\;301.25^{circ}E$). These measurements were made with a Michelson interferometer to cover wavelength regions between 1000nm and 2000 nm. A spectral analysis was performed to individual nights of data to acquire information on the waves in the upper mesosphere/lower thermosphere. It is assumed that the measured fluctuations in the intensity and temperature of the OH (3-1) airglow were caused by gravity waves propagating through the emission layer. Correlation of intensity and temperature variation revealed oscillations with periods ranging from 2 to 9 hours. We also calculated Krassovsky’s parameter and compared with published values.

• Journal of The Korean Astronomical Society
• /
• v.54 no.2
• /
• pp.49-60
• /
• 2021

Observations of line of sight (LOS) Doppler velocity and non-thermal line width in the off-limb solar corona are often used for investigating the Alfvén wave signatures in the corona. In this study, we compare LOS Doppler velocities and non-thermal line widths obtained simultaneously from two different instruments, Coronal Multichannel Polarimeter (CoMP) and Hinode/EUV Imaging Spectrometer (EIS), on various off-limb coronal regions: flaring and quiescent active regions, equatorial quiet region, and polar prominence and plume regions observed in 2012-2014. CoMP provides the polarization at the Fe xiii 10747 Å coronal forbidden lines which allows their spectral line intensity, LOS Doppler velocity, and line width to be measured with a low spectral resolution of 1.2 Å in 2-D off limb corona between 1.05 and 1.40 RSun, while Hinode/EIS gives us the EUV spectral information with a high spectral resolution (0.025 Å) in a limited field of view raster scan. In order to compare them, we make pseudo raster scan CoMP maps using information of each EIS scan slit time and position. We compare the CoMP and EIS spectroscopic maps by visual inspection, and examine their pixel to pixel correlations and percentages of pixel numbers satisfying the condition that the differences between CoMP and EIS spectroscopic quantities are within the EIS measurement accuracy: ±3 km s-1 for LOS Doppler velocity and ±9 km s-1 for non-thermal width. The main results are summarized as follows. By comparing CoMP and EIS Doppler velocity distributions, we find that they are consistent with each other overall in the active regions and equatorial quiet region (0.25 ≤ CC ≤ 0.7), while they are partially similar to each other in the overlying loops of prominences and near the bottom of the polar plume (0.02 ≤ CC ≤ 0.18). CoMP Doppler velocities are consistent with the EIS ones within the EIS measurement accuracy in most regions (≥ 87% of pixels) except for the polar region (45% of pixels). We find that CoMP and EIS non-thermal width distributions are similar overall in the active regions (0.06 ≤ CC ≤ 0.61), while they seem to be different in the others (-0.1 ≤ CC ≤ 0.00). CoMP non-thermal widths are similar to EIS ones within the EIS measurement accuracy in a quiescent active region (79% of pixels), while they do not match in the other regions (≤ 61% of pixels); the CoMP observations tend to underestimate the widths by about 20% to 40% compared to the EIS ones. Our results demonstrate that CoMP observations can provide reliable 2-D LOS Doppler velocity distributions on active regions and might provide their non-thermal width distributions.