• Korean Journal of Environmental Agriculture
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• v.24 no.4
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• pp.370-378
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• 2005

The characteristics of heavy metal biosorption on the seaweeds were investigated to develop a biological treatment technology for wastewater polluted with heavy metals. The heavy metal biosorption on seaweeds ranked in the tallowing order: U. pinnatifida$\geq$E. stolonifera$\geq$Laminaria sp.>G. amansii. The Pb was biosorbed in the range of $93{\sim}99%$, and the Cu and Cd were biosorbed in the range of $70{\sim}80%$ at the concentration of the heavy metal of $100mg/{\ell}$ respectively. The seaweed which was pretreated with $CaCl_2$ solution improved the biosorption of the heavy metals. The temperature and pH didn't affect the biosorption of heavy metals. The Langmuir isotherm reasonably fit the data of heavy metal biosorption compared to the Freundlich isotherm. The affinity of metals on the biosorption ranked in the following order: Pb>Zn>Cu>Cd. The biosorption efficiency of the heavy metals on the U. pinnatifida decreased in the multi-component rather than the single component. The heavy metals adsorbed on the U. pinnatifida were recovered using 0.3%-NTA. U. pinnatifida among the seaweed used in this work showed the best performance for the biosorption of the heavy metals.

• Reproductive and Developmental Biology
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• v.34 no.3
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• pp.263-270
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• 2010

Luteal cells produce progesterone that supports pregnancy. Steroidogenesis requires coordination of the anabolic and catabolic pathways of lipid metabolism. In the present study, the corpus luteum (CL) in early pregnancy established from luteal phase and pregnant phase was analyzed. The first study determined progesterone changes in the bovine CL at day 19 (early maternal recognition period) and day 90 in mid-pregnancy and compared them to the CL from day 12 of the estrous cycle. CL alternation was tested using two-dimensional polyacrylamide gel electrophoresis (2-DE) and matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF). Comparing CL from luteal phase to those from pregnant phase counterparts, significant changes in expression level were found in 23 proteins. Of these proteins 17 were not expressed in pregnant phase CL but expressed in luteal phase counterpart, whereas, the expression of the other 6 proteins was limited only in pregnant phase CL. Among these proteins, vimentin is considered to be involved in regulation of post-implantation development. In particular, vimentin may be used as marker for CL development during pregnancy because the expression level changed considerably in pregnant phase CL tissue compared with its luteal phase counterpart. Data from 2-DE suggest that protein expression was disorientated in mid pregnancy from luteal phase, but these changes was regulated with progression of pregnancy. These findings demonstrate CL development during mid-pregnancy from luteal phase and suggest that alternations of specific CL protein expression may be involved in maintenance of pregnancy.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.19 no.3
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• pp.171-179
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• 2018

In order to ensure the interoperability of products and technologies, companies apply standard technology in R&D but encounter various obstacles in this process, which they try to overcome through active standardization activities. Various studies have investigated the obstacles and coping strategies of companies in the R&D process. However, studies on the obstacles and coping strategies in the standardization process are insufficient, and the types of obstacles related to standardization, so a variety of studies are also needed on the types of activities. In this study, we tried to determine the types of obstacles related to standardization and to examine how these obstacles affect the standardization activities of companies. The analysis used the data from the 'National Standards Survey' which was conducted by the Korean Standards Association in Korea for companies engaged in the electrical, electronic, and information-related fields in Korea. The relationship between standard-related difficulties, needs and standardization activities was verified through structural equation modeling. The analysis results revealed that the standards-related disability issues have some influence on the standardization activities and the mediating effect by the necessity of the standard was investigated. We also found that many companies are making various efforts to overcome the barriers caused by standard activities. This suggests that a company can build a virtuous cycle structure by performing strategic actions to overcome obstacles by standardization activity and reducing the obstacles caused by standard-related research and development.

• Journal of the Korean Institute of Landscape Architecture
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• v.46 no.5
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• pp.36-43
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• 2018

In Korea, 'forest welfare' is officially included as a policy object and used as an academic term. The Korea Forest Service strives to provide a forest welfare services suitable for each life cycle from birth to death, and the public is highly aware of the need for these policies. The demand for National Woodland Burial Grounds is expected to increase as the interest in natural burials including woodland burial is increasing. As the demand for the Woodland Burial Grounds is increasing, there is only one National Woodland Burial Grounds currently available. Although other forest welfare facilities, such as natural recreation forests, must have undergone feasibility assessment according to relevant laws before approval of the designation, there are no institutions performing Woodland Burial Grounds feasibility assessments at the time. Therefore, it is necessary to consider the policies to cope with the increased demand. This study used GIS to prepare the basic data to be used in the process of selecting suitable forest locations. The area that cannot be used according to related laws was analyzed and the size of the possible areas in the state forests was assessed.

• Atmosphere
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• v.15 no.2
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• pp.101-118
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• 2005

Atmospheric ozone changes temporally and spatially according to both anthropogenic and natural causes. It is essential to quantify the natural contributions to total ozone variations for the estimation of trend caused by anthropogenic processes. The aims of this study are to understand the intrinsic natural variability of long-term total ozone changes and to estimate more reliable ozone trend caused by anthropogenic ozone-depleting materials. For doing that, long-term time series for Seoul of monthly total ozone which were measured from both ground-based Dobson Spectrophotometer (Beck #124)(1985-2004) and satellite TOMS (1979-1984) are analyzed for selected period, after dividing the whole period (1979~2004) into two periods; the former period (1979~1991) and the latter period (1992~2004). In this study, ozone trends for the time series are calculated using multiple regression models with explanatory natural oscillations for the Arctic Oscillation(AO), North Atlantic Oscillation(NAO), North Pacific Oscillation(NPO), Pacific Decadal Oscillation(PDO), Quasi Biennial Oscillation(QBO), Southern Oscillation(SO), and Solar Cycle(SC) including tropopause pressure(TROPP). Using the developed models, more reliable anthropogenic ozone trend is estimated than previous studies that considered only QBO and SC as natural oscillations (eg; WMO, 1999). The quasi-anthropogenic ozone trend in Seoul is estimated to -0.12 %/decade during the whole period, -2.39 %/decade during the former period, and +0.10 %/decade during the latter period, respectively. Consequently, the net forcing mechanism of the natural oscillations on the ozone variability might be noticeably different in two time intervals with positive forcing for the former period (1979-1991) and negative forcing for the latter period (1992-2004). These results are also found to be consistent with those analyzed from the data observed at ground stations (Sapporo, Tateno) of Japan. In addition, the recent trend analyses for Seoul show positive change-in-trend estimates of +0.75 %/decade since 1997 relative to negative trend of -1.49 %/decade existing prior to 1997, showing -0.74 %/decade for the recent 8-year period since 1997. Also, additional supporting evidence for a slowdown in ozone depletion in the upper stratosphere has been obtained by Newchurch et al.(2003).

• The Journal of Korean Medicine
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• v.32 no.6
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• pp.10-17
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• 2011

Background: Vibration response imaging (VRI) is a new technology that records energy generated by airflow during the respiration cycle. Analysis of lung sound using VRI may overcome the limitations of auscultation. Objectives: To set a VRI standard for healthy Koreans, we conducted a clinical assessment to evaluate breath sound images and quantification in healthy subjects and compared the findings with reported breath sound characteristics. Methods: Recordings were performed using the VRIxp. Eighty subjects took a deep breath four times during a 12-second interval while sitting upright. The quantitative aspect was analyzed using the VRI quantitative lung data (QLD) for total left lung, total right lung and for six lung regions: left upper lung (LUL), left middle lung (LML), left lower lung (LLL), right upper lung (RUL), right middle lung (RML), right lower lung (RLL). The qualitative aspect was provided through image assessments by three reviewers. Results: In all regions the left lung had significantly higher QLD than the right lung (P<0.005, paired t-test). The inter-rater agreement was 0.78. 84% of the images were found normal by the final assessment. Among the 16% (n=13) of images with abnormal final assessment, the most common flawed features were dynamic image (77%, n=10) and maximum energy frame (MEF) shape (77%, n=10). No significant differences were found between males and females for QLD but there were significant differences in qualitative aspects including dynamic images, MEF shape, and missing LLL. Conclusion: The characteristics of healthy Koreans are similar to those of Western subjects reported previously. VRI is easy to use and objective, and so is helpful to diagnose patients with respiratory diseases and to monitor the progress of diseases after medical treatments.

• Journal of Korean Traditional Oncology
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• v.15 no.1
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• pp.19-27
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• 2010

The roots and leaves of Angelica keiskei (AK) have been used for the treatment of various diseases including coronary heartdisease, hypertension, and cancer in the Korean folk medicine. However, the mechanism by which methylenechloride fraction (MF) from AK exerts anti-tumorigenic activity in human prostate cancer cells has not been fully understood. In the present study, we report the MF exerted the highest cytotoxicity against prostate cancer DU145 cells compared with other fractions. Especially, MF caused the accumulation of sub-G1 DNA contents of cell cycle and increased annexin V-positive apoptotic bodies and DNA fragmentation. MF down-regulated several proliferative (Cyclin D1) and anti-apoptotic (Bcl-xl, Bcl-2, IAP-1/2, and survivin)gene products in these cells. Hence, MF induced apoptosis through the caspase-3 activation in DU145 cells. We further confirmed that caspase-3 plays an importance role in MF-induced apoptosis in DU145 cells by using caspase-3 inhibitor. Additionally, we observed that MF potentiated Dox-induced apoptosis in DU145 cells. Taken together, our data demonstrate the evidence that MF induces apoptosis depend on caspase-3 activation of and overcomes resistance to chemotherapy in human prostate cancer cells.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.41 no.8
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• pp.639-648
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• 2013

This paper describes on the NOx/CO emission characteristics, temperature characteristics and flame structures when firing coal derived synthetic gas especially for gases of Buggenum and Taean IGCC. These combustion characteristics were observed by conducting ambient-pressure elevated-temperature combustion tests in GE7EA model combustor when varying heat input and nitrogen dilution ratio. Nitrogen addition caused decrement in adiabatic flame temperature, thus resulting in the NOx reduction. At low heat input condition, nitrogen dilution raised the CO emission dramatically due to incomplete combustion. These NOx reduction and CO arising phenomena were observed at certain flame temperature of $1500^{\circ}C$ and $1250^{\circ}C$, respectively. As increasing nitrogen dilution, adiabatic flame temperature and combustor liner temperature were decreased and singular points were detected due to change in flame structure such as flame lifting. From the results, the effect of nitrogen dilution on the NOx/CO and flame structure was examined, and the test data will be utilized as a reference to achieve optimal operating condition of the Taean IGCC demonstration plant.

• Asia-Pacific Journal of Business Venturing and Entrepreneurship
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• v.13 no.1
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• pp.119-129
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• 2018

Companies' efforts to secure and sustain a competitive advantage in the market may also appear in the form of new product development. This has increased the importance of leveraging knowledge from other companies in a global competition that is accelerating with an accelerating product life cycle and the development of transportation and communications. In order to create valuable knowledge through the exchange and combination of knowledge, the absorptive capacity of the recipient of the knowledge should be considered as important, but also the knowledge protection tendency, which is characteristic of the knowledge transferor, should be considered. However, studies that considered these factors at the same time were very limited. This study examines the effect of suppliers 'absorptive capacity and buyer' s knowledge protection on new product development performance during the joint development of new products. In addition, we investigated the interaction effect between supplier's absorption capacity and buyer's knowledge protection tendency. For this purpose, data were collected for automobile industry, electronics industry and defense industry, where joint development of new products occurred frequently, and statistical verification was performed by regression analysis. The results showed that the absorptive capacity of the supplier was positively correlated with the performance of the new product development, and the buyer 's knowledge protection tendency had a negative relationship with the new product development performance. In addition, the absorptive capacity of the supplier and the buyer 's knowledge protection tendency have an interaction effect on the new product development result. These results suggest that suppliers' absorption capacity is an important factor in the joint development of new products, but suppliers with superior absorption capacity may have a negative impact on new product development performance if buyers have a negative attitude toward knowledge transfer.

• The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
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• v.9 no.3
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• pp.137-152
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• 2004

The climatological characteristics of coastal zone over the southwestern coast of Korea peninsula were investigated using the data observed by AWS (automatic weather system) and 4 buoy points. Coastal zone is climatologically defined as the region bounded by the distinct contrast of temperature gradient and wind speed across coastline. In the southwest of peninsula four cross-lines consisted of AWS aligned with each buoy were selected as Geojedo buoy line, Geomundo buoy line, Chilbaldo buoy line and Dukjukdo buoy line. Analysis on the diurnal cycle and intra-month variation, monthly mean and maximum value, the temperature gradient with distance between buoy and each station and the accumulative frequency of wind speed were applied to find out the characteristics and the range of coast zone. The maximum ranges of coastal zone vary from offshore to Sanglim (about 34 km distance from coastline) for Geojedo buoy line, to Sunchun (about 52 km) for Geo-mundo buoy line, to Jaeundo (about 27 km) for chilbaldo buoy line and to Yongin (about 65 km) for Dukjukdo buoy line. The modification of coastal zone according to synoptic flow was investigated for the onshore, off-shore and calm cases. The ranges of coastal zone are significantly changed with the distance between 65∼90 km for the case of onshore. In addition, we tried to find out the variation of the wind and temperature and the wind ratio of wind speed at ocean to land stations along Geojedo buoy line during 12∼13 Sep. 2003 affected by typhoon (MAEMI).