• Korean Journal of Environment and Ecology
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• v.2 no.1
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• pp.50-65
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• 1988

Trail and campground deteriorations and their environmental changes of soil and vegetation were studied in Guryong district of Mt. Chiak National Park in 1988. The Widths of both the entire trail and the bare portion as the trail condition were significantly greater on the more heavily used trail. and regressions showed the significant positive relationship between slope along the trail and maximum depth of the trail($R^2$=0.35). Deterioration types of trail which had higher frequency for a total of 63 observations were rock exposure(48%), trail deepening(29%) and root exposure(27%) in the high order. And occurence of trail deterioration was considerably influenced by slope along the trail Ecological changes of soil and vegetation of trailsides were not found at a uniform tendency but could be grouped, by the types of user's disturbance. On campsites. tree damage types and their frequencies were basic as a means of which grasp the limits of user's impact. The area with damaged trees on campsite in pine forest were larger than that in mixed forest and the frequency by damage type of trees varied according to the distance from the core of campsite and to the crown layer. Water content, pH and hardness of soil. coverage of lower trees, species and individuals per 100$m^2$, basal areas of upper and middle layer of trees had significant relationship with the distance from campsite to forest. The range influenced by user's disturbance was more than 70-80m, md Staphylea bumalda, Morns bombycis, Stephanandra incisa and Securinega suffruticosa were considered as tolerant species to user's impact.

• Korean journal of applied entomology
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• v.53 no.4
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• pp.485-490
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• 2014

This study was conducted to assess the occurrence and damages by thrips on greenhouse-cultivated fig in Hwaseong, Gyeonggi Province, Korea. We identified the collected species as Thrips tabaci Lindeman, Frankliniella occidentalis Pergande, and F. intonsa Trybom. The density of thrips in the greenhouses during the summer months was monitored using yellow sticky traps; T. tabaci showed the highest density, followed by F. occidentalis and F. intonsa. The damages by thrips were characterized by stunted plant growth because of delayed discoloration of the pericarp, and development of rough fruit surface. Stereomicroscopic observation on the fruit flesh revealed the growth of gray mold at the damaged area, as well as the dead bodies and exuviae of thrips. The rates of fig fruit damages per month, were 18.2%, 9.7%, 2.9%, and 1.3% in July, August, September, and October, respectively.

• Proceedings of the Korean Society of Crop Science Conference
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• 2017.06a
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• pp.326-326
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• 2017

Climate warming is the issue on the global scale. Soybean can be seriously damaged when high temperature occurs during a reproductive stage such as the flowering and pod-setting period according to the Representative Concentration Pathway (RCP) (2021~2100) 8.5 scenarios. The weather in 2016 was very different from other years (average for 30 years from 1980 to 2010) ; the highest temperature was $33.7^{\circ}C$ which was higher $3.29^{\circ}C$ than average temperature from last 30 years and average rainfall was 26.5 mm, lower 140.9 mm than average rainfalls from other years. Especially, the highest temperature during soybean flow-ering and pod setting stage was $26.8^{\circ}C$ which was higher $0.1^{\circ}C$ and rainfall was 172.2 mm, higher 47.8 mm than other years from the first to the 20th in the October at soybean seed elongation stage. Soybean leaves were turned upside down by the drought stress during the flowering and pod-setting stage. The numbe-r of pods and seeds per unit area decreased 11.0% and 30.3% compared with the previous year, respectively. The ripening period was prolonged by 21 days because of high temperature and soil moisture contents due to the continual rainmade increase of the seed weight up to 15.6% and the yield decreased 7.1% compared to the previous year.

• Horticultural Science & Technology
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• v.31 no.4
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• pp.429-436
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• 2013

Kimchi cabbage 'Choongwang' cultivar is mainly cultivated during summer in Gangneung area. 'Choongwang' cultivar was harvested in late July, applied with predrying, room cooling, and forced air cooling, and then packaged with/without 0.02 mm HDPE film to estimate the effect of postharvest treatment on quality characteristics (weight loss, trimming loss, firmness, SSC, color index, sensory evaluation) during 8 week storage at $2^{\circ}C$. Kimchi cabbage without 0.02 mm HDPE film showed high weight loss up to 13-20% while those of with liner were significantly lower. Also forced air cooling among the postharvest treatments was effective to reduce both weight loss and trimming loss. Appearance and freshness in sensory evaluation were the important factors in estimating good quality during storage. Liner treatment with forced air cooling showed highly significant for maintaining appearance and freshness ($P{\leq}0.01$). Color index was no differences between with/without 0.02 mm HDPE film and postharvest treatments. After 6 weeks storage in without 0.02 mm HDPE film with room cooling or control appearance was severely damaged and also internal browning was found. While in with 0.02 mm HDPE film internal browning was found after 8 weeks storage, just in room cooling or predrying treatment.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.24 no.1
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• pp.52-58
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• 1991

Mass mortality of Halocynthia roretzi has been occurred in culturing grounds of southern coast of Korea during the long period of summer drought and the unusal high water temperature in 1988. Especially Halocynthia roretzi was damaged severely in 2 years group. Therefore we verified these phenomena by observing the environmental factors of culturing grounds and by evaluating oxygen consumption rate in indoor experiment. In culturing grounds, the mortality rate was high in Namhae Mizo area where water temperature was the highest and the lowest in dissolved oxygen concentration as low as 3.76m/l in field observation. In indoor experiment, the higher the water temperature, the more mortality was occurred and the salinity above 30 had no effect on its mortality. In oxygen consumption rate experiment, the smaller needs more oxygen than larger one, i. e., oxygen demand per unit weight was higher in 2 years group than that of 3 years. The theoretical and the actual minimum oxygen demands(MOB) for preventing asphixation was 3.7ml/kg/h at $20^{\circ}C$ and 6.3ml/kg/h gat $25^{\circ}C$, But actual MOD was 4.3ml/kg/h at $25^{\circ}C$ in indoor experiment. It seemed that mass mortality of Halocynthia roretzi in summer was caused by metabolism disorder due to insufficient oxygen level influenced by the high water temperature and the high density of Halocynthia roretzi, which results in the paucity of oxygen especially in 2 years groups.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• v.37 no.5
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• pp.415-420
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• 2011

Purpose: Calcium phosphate cement (CPC) is one of many useful materials for restoring tooth defects, periodontium and maxillofacial area. Chitosan is a biodegradable material that has been shown to promote the growth and differentiation of osteoblasts in culture. This study examined the interaction between odontoblasts and bio-calcium phosphate cement reinforced with chitosan. Materials and Methods: $5{\times}10^3$ odontoblastic cells were seeded into each well. Various concentrations of bio-calcium phosphate cement reinforced with chitosan (10, 20, 50, 100, 200, 500 ${\mu}g$/ml, 1, 2, 4 mg/ml) were diluted and added to the wells. The well was incubated for 24 h, 48 h and 72 h. After incubation, the number of cells was assessed to determine the cell viability. A cytokinesis-block micronucleus assay and chromosomal aberration test were carried out to estimate the extent of chromosomal abnormalities. Microscopic photographs and RT-PCR were performed to examine the adhesion potential of bio-calcium phosphate cement reinforced with chitosan. Results: Bio-CPC-reinforced chitosan did not show significant cytotoxicity. The number of damaged chromosomes in the cells treated with Bio-CPC-reinforced chitosan was similar to that in the control cells. There was no significant increase in the number of chromosomal aberrations in the Bio-CPC reinforced chitosan exposed cells. Microscopic photographs and RT-PCR confirmed the adhesive potential of bio-CPC reinforced chitosan to odontoblasts. Conclusion: Bio-CPC-reinforced chitosan did not affect the odontoblastic cell viability, and had no significant cytotoxic effect. Bio-CPC-reinforced chitosan showed adhesive potential to odontoblasts. These results are expected form the basis of future studies on the effectiveness of dental restorative materials in Bio-CPC reinforced with chitosan.

• Journal of the Korean Institute of Landscape Architecture
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• v.45 no.5
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• pp.1-13
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• 2017

This study was intended to provide management directions through the provision of tree spatial information as basic data for the preservation of Gyerim(legal historical site), which is located in Gyeongju city, Gyeonsangnam-do, Korea. As a result of the survey of the entire forest, there are a total of 25 species and 510 individuals growing trees. Of these species, 14 species are native and 14 are introduced species. Apart from Sophora japonica, Zelkova serrata, Celtis sinensis, most of the introduced species were adopted without historical basis after designation as a historical site. By a ratio of 36% to introduced species(including 3% of naturalized species; Ailanthus altissima), the historical heritage was significantly damaged. Gyerim, which has over 2,000 years of history, has a total 15 individuals(2.9%) large trees(over 100cm DBH). Ten of these are Salix glandulosa, and in the past, most of this area was considered a Salix glandulosa forest. Currently, however, there are many small trees(under 20cm DBH) for the next generation of growth and the Salix glandulosa forest will continue to decline. Furthermore, most small trees were afforested, so the historicity and place features as a mythological forest will quickly fade.

• Conservation Science in Museum
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• v.22
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• pp.53-68
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• 2019

Two lime-soil mixture barrier tombs were excavated from the tomb complex of the Woo Family of the Danyang Wu clan dating to the Joseon dynasty in Godeung-dong, Seongnam-si, Gyeonggi-do. Relevant records offer information for more precisely dating these tombs and identifying their occupants. Tomb No. 4, in which a married couple was interred, has a corbeled square ceiling and inscriptions and paintings on its outer walls. The conservation treatment and an infrared inspection revealed that they were intended to express mourning. Tomb No. 6 has a corbeled rectangular ceiling and a single individual interred within. As the basic structure of the tomb was partially damaged in the process of disassembling it while moving the burial site, it was planned to exhibit the tomb outdoors after the remains and relics are collected. However, as the conservation treatment revealed the presence of funeral fans and pitch, and since the remaining structure clearly demonstrates the features of lime-soil mixture barrier tombs from the Joseon dynasty, the plan was changed following a meeting of an advisory council that decided in favor of presenting the tomb indoors. According to the analysis, the pitch is assumed to be resin of a rather low purity due to the immixture of foreign substances. The two tombs are expected to serve as important materials for related research, such as changes by period in the forms of Joseon-era tombs.

• Design & Manufacturing
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• v.13 no.4
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• pp.10-16
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• 2019

Semiconductor chip is bonded to the substrate by melting solder bumps. In general, the chip bonding is applied by a Reflow process or a Thermo-Compression(TC) bonding process. In this paper, we introduce a Laser Assisted Thermo-Compression bonding (LATCB) process to improve the anxiety of the existing process(Reflow, TC bonding). In the LATCB process, the chip is bonded to the substrate by irradiating a laser with a uniform energy density in the same area as the chip to melt only the solder bumps and press the chip with a Transparent Compression Module (TCM). The TCM consists of a fused silica header for penetrating the laser and pressurizing the chip, and a piezoelectric actuator (P.A.) coupled to both ends of the header for micro displacement control of the header. In addition, TCM is a structure that can pressurize the chip and deliver it to the chip and solder bumps without losing the energy of the laser. Fused silica, which is brittle, is vulnerable to deformation, so the header may be damaged when an external force is applied for pressurization or a displacement differenced is caused by piezoelectric actuators at both ends. On the other hand, in order to avoid interference between the header and the adjacent chip when pressing the chip using the TCM, the header has a notch at the bottom, and breakage due to stress concentration of the notch is expected. In this study, the thickness and notch length that the header does not break when the external force (500 N) is applied to both ends of the header are optimized using structural analysis and Coulomb-Mohr failure theory. In addition, the maximum displacement difference of the P.A.s at both ends where no break occurred in the header was derived. As a result, the thickness of the header is 11 mm, and the maximum displacement difference between both ends is 8 um.

• Korean Journal of Remote Sensing
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• v.31 no.2
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• pp.77-83
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• 2015

Leaf water content is one of important indicators that shows states of vegetation. It is important to monitor vegetation water content using remote sensing for forest management. In this study, we investigated the degree of water stress in Korean peninsula with Normalized Difference Water Index (NDWI) to study the water content of vegetation canopy. We calculated the NDWI using SPOT/VEGETATION S10 channel data over forest from 1999 to 2013. We calculated Simple Moving Average (SMA) to remove temporal noises of NDWI in time series, and used standardized anomaly to investigate temporal changes. We classified the NDWI anomalies into three scales (low, moderate, and high) in order to monitor intuitively. We also investigated suitability of the NDWI as an evaluation criterion about water stress of vegetation canopy by comparing and verifying forest fires damaged area over 150 ha. Consequently, huge forest fire occurred 24 times during the study period. Also, negative anomalies appeared in every forest fire location and their neighboring areas. In particular, we found huge forest fires where NDWI anomalies were in 'high' scale.