• 수산해양교육연구
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• 제29권2호
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• pp.526-536
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• 2017

This study intended to understand similarity of image between games and position of image attribute perceived by consumers according to the games of marine sports using MDS (Multidimensional Scaling). Through the foregoing, this study aims to provide preliminary data for establishing marketing strategies for games of marine sports by accurately understanding images of marines sports perceived by consumers. For survey targets, this study selected students of K University located in Gyeonggi-do as a population, and extracted samples using convenience sampling out of non-probability sampling methods targeting 200 students who showed intention of participation in this study, and total 188 sheets of questionnaire were used as final data excepting 12 sheets that are filled up unfaithfully or considered unreliable. For data processing, this study conducted Frequency Analysis, Descriptive Statistical Analysis, Reliability Analysis, MDS (Multidimensional Scaling) and Multiple Regression Analysis, and study results show that water ski and wakeboard(.602) have the most similar image attribute, indicating that image attributes of scuba diving and water ski(2.031) are positioned farthest with each other. As for image attribute, image attribute of water ski has appearance and progressiveness, windsurfing has an image attribute of positive, scuba diving has an image attribute of negation, and marin rafting has an image attribute of friendliness.

• 천문학회보
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• 제44권1호
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• pp.43.1-43.1
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• 2019

We perform the Lomb-Scargle Periodogram analysis to protostars identified by the JCMT Transient Survey, which monitors 8 nearby star forming regions. The observations have been done monthly for over 3 years using SCUBA-2 (the Submillimetre Common User Bolometer Array 2) in two wavelengths, 450 and $850{\mu}m$. Under the threshold of 1% False Alarm Probability, we found 16 variable sources including EC53, which is the first variable protostar detected by the JCMT Transient Survey. Most of the variable sources are cataloged as protostars (classified via the Spitzer data, Megeath et al. 2012; Dunham et al. 2015), but SerpS-MM19, which has a clear 1-year period, is a candidate of a first hydrostatic core (Maury et al. 2011; Young et al. 2018).

• 천문학회보
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• 제44권2호
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• pp.74.3-74.3
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• 2019

SCUBA-2 North Ecliptic Pole survey, one of the ongoing JCMT large programs, is designed to obtain 850 ㎛ imaging data over ~4 deg² around the NEP based on the AKARI NEP-Wide survey. By August 2019, the program is 50 % complete in terms of observing time, increasing the submillimeter coverage by a factor of 2 with the comparable depth. The rms measured in the deepest center is 0.92 mJy/beam, slightly above the 850 ㎛ confusion limit. With 4 σ detection, the source count is 50 % complete at 9 mJy. The surface density of submillimeter galaxies at this flux limit is 200 deg^-2. Multi-wavelength identification of the 850 ㎛ sources was done through the likelihood analysis based on the far-infrared (250-500 ㎛), mid-infrared (18 ㎛), near-infrared (2-4 ㎛), and optical (i-band) source catalog. We are going to present morphologies and physical properties of 850 ㎛ selected submillimeter galaxies with the help of ancillary multi-wavelength datasets over the NEP area.

• 천문학회지
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• 제51권3호
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• pp.49-63
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• 2018

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 $850{\mu}m$ source catalog, released as part of the SCUBA-2 Cosmology Legacy Survey (S2CLS) program. The SCUBA-2 $850{\mu}m$ map has a root mean square (rms) noise of $1.2mJy\;beam^{-1}$ and covers an area of $0.60degree^2$. 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.

• Ocean and Polar Research
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• 제28권3호
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• pp.225-236
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• 2006

Seagrass meadows are considered as critical habitats for a wide variety of marine organisms in coastal and estuarine ecosystems. In many cases, studies on the spatial/temporal distribution of seagrass have depended on direct observations using SCUBA diving. As an alternative method fur studying seagrass distribution, an application of hydroacoustic technique has been assessed for mapping seagrass distribution in Dongdae Bay, on the south coast of Korea, in September 2005. Data were collected using high frequency transducer (420 kHz split-beam), which was installed with towed body system. The system was linked to DGPS to make goo-referenced data. Additionally, in situ seagrass distribution has been observed using underwater cameras and SCUBA diving at four stations in order to compare with acoustic data. Acoustic survey was conducted along 23 transects with 3-4 blot ship speed. Seagrass beds were vertically limited to depths less than 3.5m and seagrass height ranged between 55 and 90cm at the study sites. Dense seagmss beds were mainly found at the entrance of the bay and at a flat area around the center of the bay. Although the study area was a relatively small, the vertical and spatial distributions of the seagrass were highly variable with bathymetry and region. Considering dominant species, Zostera marina L., preliminary estimation of seagrass biomass with acoustic and direct sampling data was approximately $56.55g/m^2$, and total biomass of 104 tones (coefficient variation: 25.77%) was estimated at the study area. Hydroacoustic method provided valuable information to understand distribution pattern and to estimate seagrass biomass.

• 천문학회보
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• 제42권1호
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• pp.39.2-39.2
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• 2017

Stars form through the gravitational collapse of molecular clouds. However, the rate at which a star gains most of its mass and the physics that drives the main phase of stellar growth is still unclear. The typical luminosity of observed protostars is smaller than what expected from the Shu's inside-out collapse model, which predicts a constant mass accretion rate. The episodic accretion model has been suggested as a solution of this luminosity problem. The JCMT Transient survey is a long term monitoring program using JCMT/SCUBA-2 to detect accretion variability of protostars in the eight nearby star-forming regions. Recently, we found a rise of the 850 micron flux at a clump in the Serpens main region at the rate of ~17% relative to the mean flux over previous observations. The submm clump is associated with a class I protostar, EC53, which has been reported as a binary system with a periodic variability. In this talk, we will provide a brief overview of the JCMT Transient Survey project, present the detection of the variable source, and discuss about follow-up observations.

• 천문학회보
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• 제44권2호
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• pp.68.2-68.2
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• 2019

Most of the stellar mass accretes during the early evolutionary stage of protostars. However, the accretion process in protostars is in a veil of the thick envelope. Monitoring the submillimeter emission from the envelope is a way to trace the accretion process in protostars since the submillimeter emission linearly responses to the temperature of the envelope, which is heated by the accretion process at the center. In the JCMT transient Survey, we detected a submillimeter variable, EC 53. EC 53 is a Class 1 protostar that was known to have a periodic variation at NIR. EC 53 has been monitored with United Kingdom InfraRed Telescope (UKIRT), Liverpool telescope, and JCMT/SCUBA-2 since we detected the 850 ㎛ flux enhancement in the JCMT transient survey. We also adopt the photometric data sets of Wide-field Infrared Survey Explorer (WISE). Over all wavelengths from NIR to submillimeter, we see two modes of variation, a 1.5-years periodic variation and a long-term increase. We present the light curves of EC 53 at multi-wavelengths and discuss the cause of variability in EC 53.

• 한국어류학회지
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• 제22권3호
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• pp.168-178
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• 2010

2006년 2월부터 10월까지 남해 거문도 연안의 암반초와 비 암반 정점의 어류 종조성을 비교 분석하였다. 어류자료는 밤에는 삼중자망으로 수집하였고, 낮에는 스쿠버 잠수관찰로 수집하였다. 조사기간 동안 세 정점에서 삼중자망에는 총 40종, 380마리, 71,426.9 g의 어류가 채집되었다. 어획된 어종 가운데 전갱이가 최우점하였으며, 그 외 홍어, 노랑가오리, 쥐치, 전기가오리, 참돔, 볼락, 꼬치고기 등이 많이 채집되었다. 암반 초 정점에서는 26종, 264마리, 46,776.7 g의 어류가 채집되었고, 우점종은 전갱이이었다. 다음으로 비 암반 정점 1에서는 17종, 45마리, 10,535.1 g의 어류가, 비 암반 정점 2에서는 19종, 71 마리, 14,115.1 g의 어류가 채집되었다. 스쿠버 다이빙에 의한 3정점 잠수조사에서는 13종, 1,749마리의 어류가 관찰되었다. 주로 관찰된 어종은 자리돔이며, 기타 범돔, 쥐치, 망상어, 육동가리돔, 뱅에돔, 용치놀래기, 노래미, 쥐돔, 볼락, 혹돔 등이 관찰되었다. 암반초에서 어류의 풍도는 어종수 7종, 개체수 1,739마리이며, 이는 전체의 99.4%를 차지하는 것이다. 거문도 해역에서 어류군집은 많은 암초성 어류들을 포함하고 있었지만, 전갱이, 고등어 같은 회유성 어종들도 다량 포함하고 있었다. 또한 암반초에서 어류의 풍도는 다른 비암반 정점들에 비해 높았으며, 암초성 어종이 대부분을 차지하였지만 낮과 밤 간에 우점종은 차이가 있었다. 결과적으로, 거문도 해 역의 높은 어류 풍도는 암반초와 같은 물리적 구조물과 관련이 있었으며, 이는 암반초지역이 많은 어류에게 주요 서식처의 하나가 될 수 있음을 시사하는 것이다.

• 한국해양학회지:바다
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• 제18권2호
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• pp.104-109
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• 2013

이번 연구에서는 서해와 남해에 서식하는 노래미(Hexagrammos agrammus)와 쥐노래미(Hexagrammos otakii)의 산란특성 연구를 위해 2012년 11월부터 12월까지 스쿠버다이빙을 통한 잠수조사를 실시하였다. 서해에서는 수심 6-7 m의 크고 작은 암반지역 위에 있는 홍조류에 노래미 난괴가 간격을 두고 부착되어 있었으며, 난괴 주변에도 홍조류가 많이 분포하고 있었다. 산란기의 노래미 수컷은 붉은색의 혼인색을 띄며 난괴를 보호하고 있었고, 수정란과 함께 은폐되어 눈에 잘 띄지 않았다. 남해의 경우 수심은 서해와 같은 6-7 m이지만, 사질 및 암반에 놓인 폐그물 위, 바위 틈, 해조가 무성한 암반지역 등 비교적 다양한 곳에 노출되어 있는 4-8개의 쥐노래미 난괴를 확인할 수 있었으며, 서해와는 다르게 외부에 노출되고 조류소통이 좋은 지역에서 난괴가 확인되었으며, 쥐노래미 수컷의 혼인색은 황금빛을 띄고 있어 쉽게 발견할 수 있었다.

• Animal Systematics, Evolution and Diversity
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• 제29권1호
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• pp.1-17
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• 2013

Micronesia is an island nation located north of Papua New Guinea in the Pacific Ocean. A survey was executed on Kosrae, which is one of the four main islands of Micronesia, during January 23-30, 2011 and January 8-15, 2012. The echinoderms were collected at eight intertidal areas and at 12 SCUBA diving points at depths of 10-50 m in the subtidal zone. They were identified based on morphological characteristics. In total, 50 species from 276 individuals were identified: three crinoids, 11 asteroids, seven ophiuroids, 10 echinoids, and 19 holothuroids. Among them, two crinoids, five asteroids, three ophiuroids, four echinoids and two holothuroids were newly recorded from Kosrae.