• Journal of Korean Society of Forest Science
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• v.98 no.6
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• pp.772-779
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• 2009

This study was conducted to estimate the carbon (C) contents in pure and mixed stands of pine (Pinus densiflora) and oak (Quercus spp.) trees for establishing the C inventory of forest ecosystems. A total of fifteen 20 m${\times}$20 m pure and mixed stands of pine and oak trees were chosen in natural forests in Hoengseong, Kangwon based on the basal area of all trees ${\geq}$ 5 cm DBH: three of 95% of pine and 5% oak trees [pine stand], three of 100% of oak trees [oak stand], and nine of 20 to 70% of pine and 80 to 30% of oak trees [mixed stand]. To estimate C contents in the study stands, biomass in vegetation, forest floor and coarse woody debris (CWD) were calculated and C concentrations in vegetation, forest floor, CWD and soil (0-30 cm) were analyzed. There was no significant difference in vegetation C contents among the stands; 147.6 Mg C/ha for the oak stand, 141.4 Mg C/ha for the pine stand and 115.8 Mg C/ha for the mixed stand. Forest floor C contents were significantly different among the stands (p<0.05); 12.7 Mg/ha for the pine stand, 9.9 Mg/ha for the oak stand, and 8.4 Mg/ha for the mixed stand. However, CWD C contents were not significantly different among the stands (p>0.05); 2.2 Mg/ha for the mixed stand, 1.7 Mg/ha for the oak stand, and 1.1 Mg/ha for the pine stand. Soil C contents up to 30 cm depth were not significantly different among the study stands; 44.4 Mg C/ha for the pine stand, 41.6 Mg C/ha for the mixed stand, and 33.3 Mg C/ha for the oak stand. Total ecosystem C contents were lower in the mixed stand than those in the pure stands, because vegetation C contents which occupied almost total ecosystem C contents were lower in the mixed stand than those in the pure stands; 199.6 Mg C/ha for the pine stand, 192.5 Mg C/ha for the oak stand and 169.1 Mg C/ha for the mixed stand. Lower vegetation C contents in the mixed stand might be influenced by interspecific competition between pine and oak trees and intraspecific competition among the oak trees resulted from high stand density. We suggest that forest management such as thinning to enhance C storage is indispensible for minimizing the competition in forest ecosystems.

• Progress in Medical Physics
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• v.16 no.2
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• pp.70-76
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• 2005

For clinical implementation of Enhanced Dynamic Wedge (EDW), it is necessary to adequately analyze and commission its dosimetric properties in comparison to common physical metal wedge (MTW). This study was implemented with the essential measurements of parameters for clinical application, such as percentage depth dose, peripheral dose, surface dose, effective wedge factor, and wedge profile. In addition, through the comparison study of EDW with open and MTW, the analysis was performed to characterize the EDW. We also compared EDW dose profiles of measured values using chamber array 24 (CA24) with calculated values using radiation treatment planning system. PDDs of EDW showed good agreements between $0.2\~0.5\%$ of open beam, but $2\%$ differences with MTW. In the result of the measurements of peripheral dose, it was shown that MTW was about $1\%$ higher than open field and EDW. The surface doses of $60^{\circ}$ MTW showed 10% lower than the others. We found that effective wedge factor of EDW had linear relationships according to Y jaw sizes and was independent of X jaw sizes and was independent of X jaw sizes and asymmetric Y jaw opening. In comparison with measured values and calculate values from Golden-STT based radiation treatment planning system (RTP system), it showed very good agreement within difference of $1\%$. It could be concluded that EDW is a very reliable and useful tool as a beam modification substitute for conventional MTW.

• Journal of the Korean Institute of Landscape Architecture
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• v.37 no.3
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• pp.105-112
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• 2009

This study has attempted to facilitate various new technologies related to indoor containers and develop a desirable planting environment after investigating the growth (including root growth) of shade-tolerant landscape plants under slit processing, a natural indoor ventilation system. The following results were found: In terms of the shoot growth of Fatsia japonica in a slit container, no distinctive difference was observed in comparison with the control group. However, growth was good when the container 250mm tall or taller. Therefore, it was verified that optical soil depth is more important than slit processing in shoot growth of Fatsia japonica. In Fatsia japonica root length was observed as follows: Control 2(250mm) > Slit 2(250mm) > Control 1(195mm) > Slit 3(360mm) > Control 3(360mm) > Slit 1(195mm). The largest growth was observed in Control 2(250mm), which had no slit processing. In term of root width, this was lower than the initial value in all groups, which means that the root grew vertically, not horizontally. In terms of plant height of Ophiopogon japonicus, a gradual increase was observed in the control group that had no slit processing. No significant growth was detected in the slit system, however. In terms of shoot number, slit containers were generally higher than the control group. In terms of fresh and dry weights, on the contrary, slit containers were mostly lower than the control group. In Ophiopogon japonicus, root length was observed as follows: Slit 2(250mm) > Slit 1(195mm) > Control 2(250mm) > Control 3(360mm) > Slit 3(360mm) > Control 1(195mm). In Ardisia japonica, slit containers were mostly greater than control group in terms of plant height. The greatest plant height was observed at Slit 2(250mm) instead of Slit 1(195mm) and Slit 3(360mm). Except for plant height and shoot number, however, no significant shoot and root growth was observed. Root length was observed as follows: Slit 2(250mm) > Slit 3(360mm) > Control 3(360mm) > Slit 1(195mm) > Control 2(250mm) > Control 1(195mm). Therefore, root length in slit containers was mostly greater than in the control group. The width of root, however, declined in general.

• Restorative Dentistry and Endodontics
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• v.35 no.3
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• pp.164-172
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• 2010

During a composite resin restoration, an anticipating contraction gap is usually tried to seal with low-viscosity resin after successive polishing, etching, rinsing and drying steps, which as a whole is called rebonding procedure. However, the gap might already have been filled with water or debris before applying the sealing resin. We hypothesized that microleakage would decrease if the rebonding agent was applied before the polishing step, i.e., immediately after curing composite resin. On the buccal and lingual surfaces of 35 extracted human molar teeth, class V cavities were prepared with the occlusal margin in enamel and the gingival margin in dentin. They were restored with a hybrid composite resin Z250 (3M ESPE, USA) using an adhesive AdperTM Single Bond 2 (3M ESPE). As rebonding agents, BisCover LV (Bisco, USA), ScotchBond Multi-Purpose adhesive (3M ESPE) and an experimental adhesive were applied on the restoration margins before polishing step or after successive polishing and etching steps. The infiltration depth of 2% methylene blue into the margin was measured using an optical stereomicroscope. The correlation between viscosity of rebonding agents and mciroleakage was also evaluated. There were no statistically significant differences in the microleakage within the rebonding procedures, within the rebonding agents, and within the margins. However, when the restorations were not rebonded, the microleakage at gingival margin was significantly higher than those groups rebonded with 3 agents (p < 0.05). The difference was not observed at the occlusal margin. No significant correlation was found between viscosity of rebonding agents and microleakage, except very weak correlation in case of rebonding after polishing and etching at gingival margin.

• Journal of the Korean Institute of Traditional Landscape Architecture
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• v.31 no.2
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• pp.20-30
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• 2013

'Paulownia tree', one of a tree species which has been with human civilization, has been widely used as a garden plant. The purpose of this study is to investigate concrete species of 'paulownia tree,' which had been planted in Korean traditional garden, the position of plantation, and consider its usefulness therefrom. The results of the study can be summarized as follows. 1. As the result of considering old literatures as encyclopedia, agricultural book (農書), gardening book, etc., there's a difference in the description of 'paulownia tree' depending on the complier, as well, the classification of concrete species is quite ambiguous. Therefore, it judged a limit which is planted based on point of the compass is not apply to species of tress of paulownia tree. Merely, the point of suitability and evasion(宜忌) related to the plantation of 'paulownia tree' could be identified in "Jeungbosanrimgyeongje(增補山林經濟) and "Imwongyeongjeji(林園經濟志)", not "Sanrimgyeongje (山林經濟)". 2. It could be confirmed again through poetry and prose which describe old garden that the words such as 'O(梧)', 'Dong(桐)', 'Odong(梧桐)', etc. were used without significant division. However, it is supposed that the species 'Odong' which was actually adopted at the garden might be Catalpa as well including Korean Paulownia and Chinese parasol tree. 3. It is considered that the reference point of suitability and evasion(宜忌) regarding 'paulownia tree' plantation was not generally applied. That is, species of paulownia tree was not divided for planting according to direction, as well, they seemed to willingly plant paulownia trees nearby the house as well, e.g. front yard or nearby yard, etc. 4. The usefulness of paulownia tree as a garden plant of an old garden played a role of 'the messenger of fall,' emphasizing a sense of the season. 5. Paulownia tree has another usefulness as a tree which adds an Ephemeral landscape. Therefore, the ancient people considered 'paulownia tree' that goes with 'the moon' the best, and enjoyed the quaint beauty of those two are juxtaposed. Also, 'paulownia tree' was utilized as a tree which adds an atmosphere of a rainy day, such as enjoying the sound of rain dropping on the 'paulownia tree', etc. The limitation of this study is that the research was performed being restricted to the translation among lots of Chinese references. Later-on task of research is the necessity of a more in-depth study through the discover of new historical sources and the accumulation of translation outcome.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.21 no.9
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• pp.432-439
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• 2020

To improve the relatively low economic efficiency of the Korean native pig, the Korean National Institute of Animal Science developed a novel pig breed, the Woori black pig (W), by crossing Korean native and Duroc (D) pigs. This study was conducted to evaluate the effects of W as a terminal sire on growth performance, body shape, and retail cut yield of crossbred pigs. By using a completely randomized design, 32 crossbred pigs were allotted to one of two treatment groups based on terminal sire. The two groups were LYD [(Landrace × Yorkshire) × D sire] and LYW [(Landrace × Yorkshire) × W sire]. The experimental assessments were conducted over 53 days. The terminal sire breed had no significant effect on body weight (BW) at d 53, or on BW gain, average daily gain, or days to reach a 90 kg body weight. Moreover, there were no significant differences in body length, body height, or chest depth between the two groups. However, there was a significant difference (p < 0.05) in backfat thickness between the LYD (17.29 mm) and LYW (18.96 mm) groups. Loin yield of crossbred pigs in the LYW group (13.11%) was significantly lower (p < 0.05) than that in the LYD group (13.85%). By contrast, the Boston butt yield was significantly higher (p < 0.05) in the LYW group (8.99%) than in the LYD group (8.21%). In conclusion, these results suggest crossbred pigs sired by a Woori black pig had growth performance, shape, and retail cut yield (except loin yield) Ed. Note: I assume the lower loin yield is a negative factor so I included this wording. similar to those sired by a Duroc pig. The results showed no overall negative effect Ed. Note: I assume the lower loin yield is a negative factor so I used this wording. on crossbred offspring, indicating the suitability of the Woori black pig as a terminal sire.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.29 no.4
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• pp.527-536
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• 1996

The patterns of diel horizontal migration (DHM) of 7 copepod species are compared as part of a general investigation of the zooplankton adaptations to the surf zone habitats. In a sandy shore surf zone of Yongil Bay, 3 sites such as the bottom and surface of 1 m water depth and water's edge are sampled with a sledge net(n=108). The surf zone copepod assemblage is dominated by 7 species; Acartia hudsonica, Fseudodiaptomus marinus, Paracalanus indicus, Calanus sinicus, Oithona similis, Sinocalanus tenellus and Labidocera bipinnata. Threefold variations in copepod abundance are observed within a diel cycle. Abundances of 7 dominant species and total copepods captured in the surface exhibit significant diel differences, but those taken in the bottom are not significantly affected by diel period. It is shown that about $90\%$ of the surf zone copepods performed DHM. The nocturnal high densities of copepods occurred for a neap tide when the offshore winds prevailed, suggesting the animals' ability for horizontal orientation and an active locomotion without invoking passive transportation by currents. Photoreactive behavior of copepods triggered by relative changes in light intensity may be a primary factor inducing DHM by aggregating in the surf zone during the night and spreading out at day; then copepods may reduce encounters with visual predators. In A. hudsonica, ontogenetic variations in timings of DHM are evident. Such variations are likely to minimize intraspecific competition for diets. Data on shoreward migration of copepods indicate that A. hudsonica, P. indicus, O. similis and S. tenellus can maintain swimming velocities of about $20m\;h^{-1}$ for durations of more than an hour. Our observations of strong diel difference in abundances point out the need for both day and night samplings in surf zone habitats, if the importance of these habitats to planktonic copepods are to be fully understood.

• The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
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• v.20 no.1
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• pp.1-15
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• 2015

Impacts of Sea Surface Temperature (SST) assimilation to the prediction of upper ocean temperature is investigated by using a regional ocean forecasting system, in which 3-dimensional optimal interpolation is applied. In the present study, Sea Surface Temperature and Sea Ice Analysis (OSTIA) dataset is adopted for the daily SST assimilation. This study mainly compares two experimental results with (Exp. DA) and without data assimilation (Exp. NoDA). When comparing both results with OSTIA SST data during Sept. 2011, Exp. NoDA shows Root Mean Square Error (RMSE) of about $1.5^{\circ}C$ at 24, 48, 72 forecast hour. On the other hand, Exp. DA yields the relatively lower RMSE of below $0.8^{\circ}C$ at all forecast hour. In particular, RMSE from Exp. DA reaches $0.57^{\circ}C$ at 24 forecast hour, indicating that the assimilation of daily SST (i.e., OSTIA) improves the performance in the early SST prediction. Furthermore, reduction ratio of RMSE in the Exp. DA reaches over 60% in the Yellow and East seas. In order to examine impacts in the shallow costal region, the SST measured by eight moored buoys around Korean peninsula is compared with both experiments. Exp. DA reveals reduction ratio of RMSE over 70% in all season except for summer, showing the contribution of OSTIA assimilation to the short-range prediction in the coastal region. In addition, the effect of SST assimilation in the upper ocean temperature is examined by the comparison with Argo data in the East Sea. The comparison shows that RMSE from Exp. DA is reduced by $1.5^{\circ}C$ up to 100 m depth in winter where vertical mixing is strong. Thus, SST assimilation is found to be efficient also in the upper ocean prediction. However, the temperature below the mixed layer in winter reveals larger difference in Exp. DA, implying that SST assimilation has still a limitation to the prediction of ocean interior.

• Journal of the Korean Society of Radiology
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• v.14 no.1
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• pp.15-22
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• 2020

PET(Positron Emission Tomography) devices are used as PET/CT or PET/MRI devices fused with the devices of CT or MRI for obtaining anatomical information. Therefore, the devices are constructed in circular ring-type structure whose length of gantry(the main part of filming) becomes wider and the interior depth becomes longer in comparison to other common medical equipments. scintillator, one of the components in PET devices, is inside the gantry, and as it is consisted of crystal which is sensitive to the change of temperature and humidity, large temperature change can cause the scintillator to be damaged. Though scintillator located inside the gantry maintains temperature and humidity with a thermo-hygrostat, changes in temperature and humidity are expected due to structural reasons. The output value was measured by dividing the inside of the gantry of the PET/CT device into six zones, each of which an Adafruit BME 280 temperature and humidity sensor was placed at. A thermo-hygrostat keeps the temperature and humidity constant in the PET/CT room. As the measured value of temperature and humidity of the sensor was obtained, the measured value of temperature and humidity appeared in the thermohygrostat was taken at the same time. Comparing the average measured values of temperature and humidity measured at each six zones with the average values of the thermo-hygrostat results in a difference of 2.71℃ in temperature and 21.5% in humidity. The measured temperature and humidity of PET Gantry is out of domestic quality control range. According to the results of the study, if there is continuous change in temperature and humidity in the future, the aging of the scintillator mounted in the PET Gantry is expected to be aging, so it is necessary to find a way to properly maintain the temperature and humidity inside the Gantry structure.

• Korean Journal of Ecology and Environment
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• v.33 no.2 s.90
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• pp.128-135
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• 2000

The authors surveyed the seasonal variations of environmental factors, the distributions of heterotrophic bacteria and Anabaena cylindrica growth-inhibiting bacteria at each water layer in Daechung Reservoir to verify the role of bacteria during the extinction of bloom. Average water depth at site 1, 2, and 3 were 25.5 m, 15.0 m and 12.3 m, respectively. Water temperature showed a typical pattern seasonally. The variation of DO was relatively inverse proportional to that of water temperature, although it was irregular during summer time. DO decreased gradually to early May, fluctuated sharply after then, and followed by gradual increasement after middle of September. This variation pattern was notable at surface layer. There was remarkable difference in DO concentraion between surface layer and the other water layers during the period in which DO irregulary varied. The variation range of chlorophyll-a concentraion at surface layer in summer time was broad, and it was relatively high when DO was high. The population size of heterotrophic bacteria was high from Spring to Autumn, an declined after September when the water temperature droped rapidly. Especially this variation pattern was prominent at the surface layer. Bacteria that inhibit the growth of A. cylindrica was almost not detected by June, and its distribution increased in July. Afterward, it showed different variation pattern between each site. The distribution of A. cylindrica growth-inhibiting bacteria was higher at the middle and bottom layer than the surface layer in July and October, when it was larger at all sites for the study period. This result suggests that the antagonistic bacteria exhibit higher activity when host activity drops. These results also suggest that natural water bacteria control the distirbution of cyanobacteria, especially its activity as controller is remarkable when cyanobacterial growth declines.