• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.21 no.1
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• pp.9-17
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• 2003

Typhoon RUSA, which caused serious damage was passed over in Korea peninsula during 30 August to 1 September, 2002. We estimated tropospheric wet delay using GPS data and meteorological data during this period. Integrated Water Vapor(IWV) gives the total amount of water vapor from tropospheric wet delay and Precipitable Water Vapor(PWV) is calculated the IWV scaled by the density of water. We obtained GPS PWV at 13th GPS permanent stations(Seoul, Wonju. Seosan, Sangju, Junju, Cheongju, Taegu, Wuljin, Jinju, Daejeon, Mokpo, Sokcho, Jeju). We retrieve GPS data hourly and use Gipsy-Oasis II software and we compare PWV and precipitation. GPS observed PWV time series demonstrate that PWV is, in general, high before and during the occurrence of the typhoon RUSA, and low after the typhoon RUSA. GPS PWV peak time at each station is related to the progress of a typhoon RUSA. We got very near result as we compare GMS Satellite image with tomograph using GPS PWV and we could present practical use possibility by numerical model for weather forecast.

• ALGAE
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• v.19 no.3
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• pp.257-270
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• 2004

In order to clarify the structure and seasonal dynamics of warm tolerant benthic marine algal community in Korea, the species composition and biomass of marine algae at the discharge canal of Uljin nuclear power plant on the East Coast of Korea were investigated seasonally from February 1992 to October 2000. 107 species of marine algae were found at the discharge canal during the past nine years. In general, the number of species observed was abundant in spring or summer and less in autumn or winter. 27 species (4 blue-green, 5 green, 6 brown and 12 red algae) of marine algae occurred more than 1/ 6 frequency and thus can be categorized as warm tolerant species. Among these, one brown (Dictyota dichotoma) and four red algae (Gelidium amansii, Anphiroa ephedraea, Hydrolithon sargassi, Marginisporum crassissimum) are recorded as warm tolerant marine algae for the first time in Korea. Padina arborescens, Anphiroa zonata and Corallina pilulifera were common species found more than 75% frequency. Seasonal fluctuations of mean biomass were 0-1,330 g dry wt m^(-2) and dominant species in biomass were Corallina pilulifera (contribution to a total biomass proportion 34%), Anphiroa zonata (23%), Padina arborescens (18%) and Sargassum micracanthum (11%). The red algae appeared as predominant algal group at the discharge canal of Uljin nuclear power plant in the qualitative and quantitative aspects. The green algae such as Enterornorpha compressa appeared rather frequently at the discharge canal, but the biomass proportion was very low, in contrast to Kori nuclear power plant where there was definite green algal dominance. Differences in algal communities developed at the discharge canals of Uljin and Kori nuclear power plant on the East Coast of Korea, particularly biomass proportions of green algae, can probably be related to local environmental factors such as water velocity through the canal and natural seawater temperatures.

• Journal of the Korean Association of Geographic Information Studies
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• v.17 no.1
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• pp.1-12
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• 2014

Crown fire, the main propagation type of large forest fire, has caused extreme damage with the fast spread rate and the high flame intensity. In this paper, we developed the probability equation to predict the crown fires using the spatial features of topography, fuel and weather in damaged area by crown fire. Eighteen variables were collected and then classified by burn severity utilizing geographic information system and remote sensing. Crown fire ratio and logistic regression model were used to select related variables and to estimate the weights for the classes of each variables. As a results, elevation, forest type, elevation relief ratio, folded aspect, plan curvature and solar insolation were related to the crown fire propagation. The crown fire propagation probability equation may can be applied to the priority setting of fuel treatment and suppression resources allocation for forest fire.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.33 no.1
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• pp.23-30
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• 2015

A shoreline mapping is essential for describing coastal areas, estimating coastal erosions and managing coastal properties. This study has planned to map the 3D shorelines with the airborne LiDAR(Light Detection and Ranging) data and the KOMPSAT-2 imagery, acquired in Uljin, Korea. Following to the study, the DSM(Digital Surface Model) is generated firstly with the given LiDAR data, while the NDWI(Normalized Difference Water Index) imagery is generated by the given KOMPSAT-2 imagery. The classification method is employed to generate water and land clusters from the NDWI imagery, as the 2D shorelines are selected from the boundaries between the two clusters. Lastly, the 3D shorelines are constructed by adding the elevation information obtained from the DSM into the generated 2D shorelines. As a result, the constructed 3D shorelines have had 0.90m horizontal accuracy and 0.10m vertical accuracy. This statistical results could be concluded in that the generated 3D shorelines shows the relatively high accuracy on classified water and land surfaces, but relatively low accuracies on unclassified water and land surfaces.

• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.50 no.4
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• pp.520-529
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• 2014

Experiment was set up to analyze bycatch and discards situation including snow crap Chionoecetes opilio of whelk trap. Four types of trap were used: drum type trap with PE net; drum type trap with PBS net; cylinder type trap with PE net; and cylinder type net with PBS net. Three funnels were attached in drum type trap and two funnels were used in cylinder type trap. A fleet of traps was consisted with one hundred traps. 25 traps of each type were set on a line in repeated sequence. Field experiments were conducted with 6 fishing operations in the Uljin waters, East Sea in July 2014. Catch of target whelks were 173,261 g and catch rate was 48.7% of total catch, while bycatch were 182,571 g, 51.3% of tatal catch. The catch rate of bycatch was 2.6% higher than that of target catch. Bycatch weight of snow crap was the highest as 142,987 g and formed about 40.2% of total catch, followed giant octopus, Enteroctopus dofleini, 31,762 g (8.9%). Bycatch rate of cylinder type trap was 2.3 times higher than that of drum type trap. Discard rate (discard/(discard+landing)) was 43.6%. Discard rate was the highest at cylinder type trap with PBS net as 63.1%, followed cylinder type trap with PE net as 47.9%, drum type trap with PE net as 33.4%, the lowest at drum type trap with PBS net as 22.1%.

• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.50 no.4
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• pp.583-594
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• 2014

This study was performed to estimate biomass and provide management guidance through population ecological characteristics, including growth parameters, instantaneous coefficients of natural and fishing mortalities, and age at first capture of the starry flounder, Platichthys stellatus and olive flounder, Paralichthys olivaceus of Korea. For describing growth of this species, a von Bertalanffy growth model was adopted. The von Bertalanffy growth parameters estimated from a non-linear regression for starry flounder were $L_{{\infty}}=48.25cm$, K=0.16/yr, and $t_0=-1.48$, respectively and those for olive flounder were $L_{{\infty}}=86.46cm$, K=0.26/yr, and $t_0=-0.29$, respectively. Biomass of Platichthys stellatus was estimated by direct biomass estimation method was 2.6 M/T, that was estimated by indirect method was 13.4 M/Tt. Those of Paralichthys olivaceus were estimated as 10.1 M/T, 19.3 M/T, respectively. An yield per recruit analysis showed that the current yield per recruit on Platichthys stellatus was about 48.2 g with F=0.646/yr and the age at first capture ($t_c$) 1.35yr, that on Paralichthys olivaceus was about 167.6 g with F=1.121/yr and the age at first capture ($t_c$) 1yr.

• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.50 no.4
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• pp.567-582
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• 2014

Coastal fisheries in Korean waters have highly complexity with a variety of fishing gears, and scale of those fisheries is smaller than that of offshore fisheries. As a result, important spawning and nursery grounds for many species of fish has been destroyed. The pragmatic ecosystem-based approach was developed for the assessment of fisheries resources in Korean waters by Zhang et al. (2009; 2010). As for the species risk index (SRI), common squid caught by coastal gillnet in the Uljin region had the highest risk. As for the fisheries risk index (FRI), coastal gillnet in the Uljin coastal waters had the highest risk. For the common squid which had the highest SRI, resources management strategies must be established such as catch prohibition of length and period with TAC. For the coastal gillnet in the Uljin region which had the highest FRI, it is judged to need management plans for conserving biodiversity as reducing the catch of non-target species and discards. Also to protect existing habitat, illegal fishery should be prohibited, and fishing gears should be designed in the environmental-friendly way considering when fishing gears lost.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.30 no.1
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• pp.97-104
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• 2012

In this paper, the GPS precipitable water vapor was retrieved by estimating of GPS signal delay in the troposphere during the progress of heavy snowfall on the Gangwon Province, 2011. For this period, the time series analysis between GPS precipitable water vapor and fresh snow depth was accomplished. The time series and the comparison with the GPS precipitable water vapor and the fresh snow depth indicates that the temporal change of two variations is closely related to the progress of the heavy snowfall. Also, the periodicity of GPS precipitable water vapor using the wavelet transform method was showed a similar cycle of saturated water vapor pressure as the limitation of this study span. The result shows that the decrement of GPS precipitable water vapor was conflicted with the increment of fresh snow depth at two sites, Gangneung and Uljin. The correlation between the GPS precipitable water vapor and the saturated water vapor pressure for the event was showed a positive correlation, compare with the non-heavy snowfall periods.

• Journal of Aquaculture
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• v.13 no.3
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• pp.245-251
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• 2000

Carapace width (CW) of main size class of the snow crab was 70~90 mm for females and 80~100 mm for males. The CW holds a stronger relation with body weight than that of carapace length (CL). The number of eggs attached to the pleopods was in the range of 35,000 and 114,000 eggs in crabs with 65 and 88 mm CW, respectively). The logistic maturity curve on morphometric measurements and gonad examination, defined by the presence of egg brooding in wide abdomen of the female and spermatophores inside the vasa deferentia of the male indicated that 50 % of crabs attained gonadal maturity at 54.2 mm and 58.8 mm CW for females and males, respectively. In the relationship between CW and body weight, a sharp break at 53~55 mm CW indicates that morphological changes associated with maturity have occurred.

• The Journal of the Petrological Society of Korea
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• v.11 no.3_4
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• pp.271-277
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• 2002

Pyeonghae Series, Giseong Series. Wonnam Series, Pyeonghae Unite gneiss, Hada leuco-granite gneiss are the Precambrian gneisses distributed in the north-eastern part of the Yeongnam massif. Even though there are no difference in lithologies between Pyeonghae and Wonnam Serieses. they have been regarded as different Serieses because of the presence of Giseong Series which has been considered meta-volcanics. However, field investigations reveal that the Giseong Series represents ductile shear zone having meta-volcanics-like appearances in some outcrops. The fact that both Pyeonghae and Wonnam Serieses experienced high grade metamorphism reaching upper amphibolite facies implies that any volcanics between these two Serieses should also occur as high-grade metamorphic rocks at present. The absence of Giseong Series as a low-grade meta-volcanics indicates the absence of logical base to distinguish Pyeonghae and Wonnam Serieses. Therefore, these two Serieses should be regarded as identical Series.