• Korean Journal of Fisheries and Aquatic Sciences
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• v.38 no.3
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• pp.205-213
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• 2005

A hydroacoustic and a close-open-close zooplankton net survey were conducted to understand the distribution characteristics of the deep scattering layer (DSL) and to estimate the density of zooplankton in the DSL, in the Uljin coastal area. The survey was carried out during March 13-14 and June 4-5, 2003 at each station for zooplankton. The vertical migration mechanisms of zooplankton are very variable to the taxa. In this study, after we grasp the vertical migration of zooplankton through the results of an echo-sounder survey, we verified the mechanisms of their vertical migration in the Uljin coastal area. Also, to estimate effectively the biomass of zooplankton, we researched the acoustic scattering strength according to the species. On the basis of these results, we devised a method for estimating zooplankton biomass through comparing net and echo-soundings. We obtained the results as a follows; 1) According to the examination of collections from the net sampling, in March, 2003, Euphausia pacifica comprised $38\%$ of zooplanktons inhabiting the sound scattering layer, while copepods, chaetognaths, and amphipods accounted for $29\%,\;23\%\;and\;10\%$, respectively. And in June, 2003, the ratio of E. pacifica was $51\%$, copepods $43\%$, and the others comprised $6\%$. In both March and June E. pacifica showed dominance among the species of zooplankton. 2) The analysis of vertical distribution through acoustic data in the scattering layer was more apparent in June (spring/summer) of 2003, than in March (winter/spring) of that year. The vertical migration of zooplankton peaked around sunrise and sunset in both March and June. 3) As for the sound scattering layer, it distributed in the open sea in March, and in the inland sea in June. Therefore it is suggested that some zooplankton species such as E. pacifica performed ontogenic horizontal migration througth the spring and early summer.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.24 no.5
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• pp.315-326
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• 1991

This study was tried for a mathematical approaches related to daily fluctuations in the stomach fullness of Agrammus agrammus. The specimen was collected by angling and gill net from September 1984 to August 1985 off Shinsudo, Samchonpo. Fullness of the stomachs was increased in the early morning and the late afternoon, decreased in the late morning, at noon, and during the night. That is, feeding activity of the fish was more intense at sunrise and sunset. Daily feeding activity of the fish in a day was divided into the time period of gastric evacuation and both feeding and gastric evacuation. Stomach fullness with the lapse of time in the time period of gastric evacuation was geometrically decreased. Stomach fullness in the time period of both feeding and gastric evacuation was affected by gastric evacuation rates, feeding rates, and maximum fullness of the stomach. These parameters were able to estimate from the method estimating the regression coefficient in the relationship between the time(t) and the stomach fullness$(F_t)$, or between stomach fullness at the time t and $t+\Deltat$. The rates of feeding and gastric evacuation were the highest in spring and the lowest in winter. The relationships between time(t) and stomach fullness$(F_t)$ in the time period of gastric evacuation and both feeding and gastric evacuation induced from hypotheses were respectively as follows. $$F_t=F_{to}e^{-r(t-to)}$$, $$F_t=F\infty-(F\infty-F_{to})e^{-(p+r)(t-{to})}$$

• Publications of The Korean Astronomical Society
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• v.28 no.2
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• pp.25-36
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• 2013

Chumsungdae is an ancient astronomical observatory whose main role was doing 'chunmoon'. It was administrate by a royal advisory agency on state affairs. The observers observed the heaven on the observatory platform, recorded peculiar events, and watched and interpreted the signs displayed in the heaven. Chumsungdae is an stonemasonry which represents almanac principles with its peculiar shapes and the numbers of strata and stones. The numbers were thoroughly invented to match exactly the almanac constants. Chumsungdae is comprised largely of three main parts, namely the square base, the stratified cylindrical body, and the top #-shaped stonework, and the total number of stones is 404. The number of the strata (27) and the height of the cylindrical body (27 尺) stand for the days in a sidereal month (27.3 days), which implies that the motion of the Moon with respect to the stars was given more priority than to the Sun at that time of geocentricism. And the cylindrical body was thoroughly designed to consist of 365 stones, which is of course the number of days in a solar year. In addition, there are 12 strata each under and above the south entrance and this in sum makes the 24 divisions of the year. Also there is 182 stones below the 13th stratum and this represents the number of days in the winter ~ summer solstice period, and the rest 183 stones the vice versa. The #-shaped top stonework was aligned in such a way that one of the diagonals points the direction of sunrise on the winter solstice. The square base also layed with the same manner. The south entrance was built 16 degrees SE, and the upright direction of the right pillar stone coincides with the meridian circle. This was a kind of built-in standard meridian circle facilitating the observations. In a symbolic sense, Chumsungdae was thought as the tunnel reaching the heaven, where the observers wished to be enlightened with the signs and inspirations in need. With the craftsmanship and skill, the builder reinforced the stratified cylindrical body with two sets of #-shaped beam stones, piercing at a right angle at 19th ~ 20th and 25th ~ 26th strata. Likewise, by placing the double #-shaped stonework with 8 beam stones on the platform of the observatory, both the stability of the stonemasonry and a guard rail for the nightly observers were securely provided.

• Korean Journal of Medicinal Crop Science
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• v.19 no.3
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• pp.157-161
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• 2011

Growth characteristics, root yield and ginsenoside contents of 3-year-old ginseng in greenhouse shaded by $30^{\circ}$ sloped-curtain made of aluminum were compared to traditional shade facility in order to develop cultural practice for organic ginseng. Light transmittance ratio in greenhouse with $30^{\circ}$ sloped-curtain shade was distinctly lower than that of traditional shade from sunrise to 9 a.m., while its ratio in greenhouse was higher than traditional shade since 9 a.m. due to the reflection of light. Air temperature of greenhouse was $1.3^{\circ}C$ higher than that of traditional shade on the first ten days of August due to more reflected light. Root yield of greenhouse was 44% higher than that of traditional cultivation because of the inflow of reflected light and the decrease of disease of Alternaria and Anthracnose by blocking rainfall. Dry matter partitioning ratio of rhizome and lateral root were increased in ginseng cultivated at greenhouse due to longer survival time in leaf than traditional cultivation. Total ginsenoside contents cultivated at greenhouse was decreased in the part of taproot, while it was increased in the part of lateral and fine root compare to traditional cultivation. Individual ginsenoside contents between greenhouse and traditional cultivation showed significant difference more frequent in fine root than taproot and lateral root. Total ginsenoside contents including $Rb_1$, $Rb_2$, Rc, Rd, Re, Rf, $Rg_1$, and $Rg_2$ in whole root of 3-year-old ginseng did not showed significant difference by greenhouse and traditional cultivation.

• Korean journal of applied entomology
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• v.27 no.2
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• pp.111-116
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• 1988

Fruit piercing moths were collected at every other at orchaed(16.5ha) planted with plum, peach and pear, and surrounded by forest in Gyeongnam province from jun to September in 1987. Four black light (BL) traps were lightened to attract the moths from sunset to sunrise and sweep net was also used to catch the moths on fruit and around fruit trees from 22 to 23 o'clock, 20 minutes per fruit tree species. Forty-one species, including 15 primary piercing species(PPS) and 22 secondary piercing species (SPS), from 3 families were collected and identified as fruit piercing moths. Among them, 16 species are newly recorded as fruit piercing moths in Korea. O. emarginata, L. juno, P. stuposa, C. lata and O. excavata were diminant species of PPS, comprising 86.7% of the whole PPS. Dominant species of SPS were A. ipsilon, M. turca, S. retorata, A. livida and T. oldenlandiae, comprising 80.5% of the whole SPS. The ratios of PPS to the whole fruit piercing moths collected by BL traps and net were sweep 15.2% and 79.7%, repectively. By sweep net L. juno, P. stuposa, and O. emarginata was also captured in a large numbers on peach, C. lata was on plum, and S. retorata was on pear.

• Korean Journal of Ichthyology
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• v.19 no.3
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• pp.236-245
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• 2007

Feeding habits of Liobagrus andersoni were investigated in a tributary of the Namhan river from October 2005 to October 2006. L. andersoni was considered as an entirely bottom-feeding carnivore based on it's stomach contents. Because, the diet of L. andersoni was mainly aquatic insect such as Ephemeroptera, Trichoptera, Diptera. The most important prey was Ephemeroptera species. Small sized individuals (<50 mm SL) fed mainly on small prey organisms such as Baetis. However, larger Ephemeroptera and Trichoptera were heavily selected with increasing fish size. The relative proportion of food items was changed with season. The prey materials were more various at summer and autumn than winter. L. andersoni eaten Ephemeroptera intensively in spring and summer but eaten Trichoptera and Chironomidae in winter. Feeding activity of L. andersoni was started after sunset and was most active at midnight, but the activity was reduced after sunrise and during day period. So it was considered that L. andersoni was a nocturnal stalkers.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.19 no.11
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• pp.2597-2602
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• 2015

With the development of economy and improving of people's living standards, people dietary needs will be achieved from subsistence to high nutrition and from high nutrition to healthy transformation. Mushroom as a kind of highly nutritious, low fat, rich vitamin food has a great interest among the people. This makes the mushroom into a new sunrise industry and it gradually from pure manual cultivation develops toward the fully automatic factory. In the process of mushroom factory production, regulation of environmental factors directly affects the yield and quality of mushroom. In related to the methods of mushroom cultivation, the recent technologies apply the new technology such as sensors and IT convergence services. And then cultivating mushroom is managed effectively. This paper in order to solve the above problems and construct an effective mushroom growth environment using technology such as humidity sensor construct an environment that can automatically adjust the humidity. This environment has important significance to improve the level of automation mushroom production, increase yield per unit area and quality of mushroom, increase economic efficiency of mushroom production, and enhance the competitiveness of mushroom production.

• Journal of the Korean Society of Environmental Restoration Technology
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• v.24 no.6
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• pp.109-119
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• 2021

Thermal environment of city is getting worse due to severe urban heat island caused by climate change and urbanization. Green roof improves the urban thermal environment and save the cooling energy in buildings. This study presented a green roof combined with a storage system that stores rain-water and supplies water through a wick and evaluated the temperature reduction effect as surface temperature and amount of evapotranspiration. For about a week, the surface temperature using a infrared thermal imager and the evapotranspiration by recording change of module weight were measured at intervals of 30 minutes from sunrise to sunset. The results show that the mean surface temperature of the green roof was 15.4 degrees lower than that of the non-green roof from 12:00 P.M. to 14:00 P.M. There was no significant difference between mean surface temperature of green roof with and without storage system immediately after rain, but more than a week after rain, there was a difference with average of 2.49 degrees and maximum of 4.72 degrees. The difference in daily amount of evapotranspiration was measured to be 1.66 times on average. As drought stress increased over time, the difference in daily amount of evapotranspiration and surface temperature between with/without storage system increased simultaneously. The results of the study show a more excellent cooling effect of green roof combined with the rainwater storage system.

• Korean Journal of Agricultural and Forest Meteorology
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• v.24 no.2
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• pp.95-114
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• 2022

This study presented the possibility of automatic frost observation and the related image data acquisition through the design and installation of a Multiple-sensor based Frost Observation System (MFOS). The MFOS is composed of an RGB camera, a thermal camera and a leaf wetness sensor, and each device performs complementary roles. Through the test operation of the equipment before the occurrence of frost, the voltage value of the leaf wetness sensor increased when maintaining high relative humidity in the case of no precipitation. In the case of Gapyeong- gun, the high relative humidity was maintained due to the surrounding agricultural waterways, so the voltage value increased significantly. In the RGB camera image, leaf wetness sensor and the surface were not observed before sunrise and after sunset, but were observed for the rest of the time. In the case of precipitation, the voltage value of the leaf wetness sensor rapidly increased during the precipitation period and decreased after the precipitation was terminated. In the RGB camera image, the leaf wetness sensor and surface were observed regardless of the precipitation phenomenon, but the thermal camera image was taken due to the precipitation phenomenon, but the leaf wetness sensor and surface were not observed. Through, where actual frost occurred, it was confirmed that the voltage value of leaf wetness sensor was higher than the range corresponding to frost, but frost was observed on the surface and equipment surface by the RGB camera.

• Food Science of Animal Resources
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• v.42 no.5
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• pp.816-832
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• 2022

To evaluate the effects of early postmortem vacuum packaging (VP) on meat quality during postmortem chilled storage, hot-boned lamb was vacuum-packaged at 1, 6, 12, 24, and 48 h postmortem and stored around 2℃ until 168 h postmortem, with lamb packaged in plastic wrap as the control (aerobic packaging). Intramuscular pH decline was delayed when lamb was vacuum packaged at 1, 6, and 12 h postmortem (p<0.05). The lamb vacuum-packaged at 1 h postmortem (VP-1h group) had significantly lower shear force values and purge losses accompanied by lower free thiol group values than other treatments during postmortem storage and was also higher in extractable calpain-1 activity by 6 h postmortem (p<0.05). Free thiol group concentrations were significantly higher after VP at 6 and 12 h postmortem (p<0.05). Packaging lamb under vacuum very early postmortem produced the lowest shear force and purge loss, likely by slowing heat loss and muscle temperature decline, implying that lamb quality is improved by VP when applied very early postmortem. This was at the expense of protein oxidation, which was unrelated to other meat quality measurements, most likely because potential contracture during hot boning confounded its impact. Further research is required to understand the implications of the interaction between protein oxidation, VP, and hot boning on the acceptability of lamb.