Changes of Landscape Structure for the Recent 20 Years in the Wangsuk Stream Basin of the Central Korea

Lee, Chang-Seok,Cho, Yong-Chan,Shin, Hyun-Chul,Lee, Seon-Mi The Ecological Society of Korea 2006 Journal of Ecology and Environment Vol.29 No.4

Landscape changes for 20 years between 1981 and 2001 in the Wangsuk stream basin located on the central Korea were investigated on the basis of physiognomic vegetation map made from the aerial photograph interpretation and field check. Changes of landscape structure were noticeable in agricultural field and forest landscape elements. Changes in the agricultural fields due to transformation of agricultural pattern into the institutional agriculture dominated landscape change, although urbanization also contributed to such change. The former change due to change of food production structure originated from socio-economic development during this period and the latter to the overpopulation of Seoul. As energy sources for heating and cooking, fertilizer, and fodder for livestock transform from plant materials to fossil fuel, manufactured one, and grain, succession of forest escaped from direct human disturbance dominated change of landscape structure in forested land. Differently from the positive landscape change in the upper area, change in the lower area deteriorated landscape quality by increasing artificial land. It was estimated that such landscape deterioration in the Wangsuk stream basin would influence water quality of the stream. In order to realize sustainable land-use against such environmental degradation, systematic environmental management based on landscape ecological perspective such as "an eco-plan for creating riparian vegetation belt," which is under preparation by Ministry of Environment, was recommended.

Vegetation change and emerging research feedback for Korean National Long Term Ecological Research (KNLTER)

Cho, Yong-Chan,Lee, Chang-Seok,Cho, Hyun-Je,Lee, Kyu-Song,Park, Pil-Sun The Ecological Society of Korea 2011 Journal of Ecology and Environment Vol.34 No.1

Various responses of forest ecosystems to climate change underscore the need to improve our understanding of the environmentally-driven changes in forests, most effectively by long-term monitoring protocols. We have explored vegetation dynamics based on changes in community structure, species composition, diversity and demographics in four Korean National Long Term Ecological Research (KNLTER) sites--Mt. Nam, Mt. Jeombong, Mt. Worak, and Mt. Jiri--between 2004 and 2009. Most of the sites and forests studied exhibited increments in total basal area, but this was not observed in Quercus mongolica forests in Mt. Nam and Mt. Worak. Stem density exhibited various changes. Altitude gradient was the representative factor in differences in species composition. Two patterns of compositional change--convergence and divergence--were detected. The vegetation of Mt. Nam and Q. mongolica community of Mt. Work showed relatively larger changes in composition. However, in the other sites, few changes were observed. Changes of species richness were not notable except for Mt. Nam, where three species were added in the pine forest, whereas one species disappeared in the oak forest. In the oak forests, mortality rate was as follows (in descending order): Mt. Nam (25.5%), Mt. Jeombong (24.3%), Mt. Worak (16.4%) and Mt. Jiri (0.8%). In the pine forest, the recruitment rate was as follows (in descending order): Mt. Nam (63.7%), Mt. Worak (12.9%), Mt. Jeombong (7.6%) and Mt. Jiri (7.3%). The mortality rate and change rate of basal area were strongly negatively correlated (r = -0.9, P = 0.002), and the recruitment rate and change rate of density were positively correlated (r = 0.77, P = 0.026). In the KNLTER sites, larger vegetation changes were attributed to anthropogenic activities such as salvage logging. Suppression or competition for resources would also affect these changes. Research suggestions such as monitoring to clarify the causes of species mortality were discussed.

Which Environmental Factors Caused Lammas Shoot Growth of Korean Red Pine?

Lee, Chang-Seok,Song, Hye-Gyung,Kim, Hye-Soo,Lee, Bit-Na-Ra,Pi, Jeong-Hoon,Cho, Yong-Chan,Seol, Eun-Sil,Oh, Woo-Seok,Park, Sung-Ae,Lee, Seon-Mi The Ecological Society of Korea 2007 Journal of Ecology and Environment Vol.30 No.1

Lammas growth, a rare phenomenon for Korean red pine (Pinus densiflora), occurred in 2006. Lammas shoots showed higher frequency and longer length in Seoul's hotter urban center than in urban boundary or suburban forest sites. Frequency and length showed a close correlation with urbanization density and vegetation cover expressed in NDVI. Air temperature in the late summer of 2006 was more than $1^{\circ}C$ higher than an average year. Of the predominant environmental signals that modulate bud flush, only temperature changed significantly during the year. Differences in temperature between the urban centers, urban boundaries and suburban forests correlated with varying land-use density. The rise in temperature likely spurred lammas growth of the Korean red pine. Symptoms of climate change are being detected throughout the world, and its consequences will be clearer in the future. Considerate interest in the responses of ecological systems to the variable changes is required to prepare for unforeseeable crises. Monitoring of diverse ecological phenomena at Long Term Ecological Research sites could offer harbingers of change.

Projections of summertime ozone concentration over East Asia under multiple IPCC SRES emission scenarios

Lee, Jae-Bum,Cha, Jun-Seok,Hong, Sung-Chul,Choi, Jin-Young,Myoung, Ji-Su,Park, Rokjin J.,Woo, Jung-Hun,Ho, Changhoi,Han, Jin-Seok,Song, Chang-Keun Elsevier 2015 Atmospheric environment Vol.106 No.-

<P><B>Abstract</B></P> <P>We have developed the Integrated Climate and Air Quality Modeling System (ICAMS) through the one-way nesting of global–regional models to examine the changes in the surface ozone concentrations over East Asia under future climate scenarios. Model simulations have been conducted for the present period of 1996–2005 to evaluate the performance of ICAMS. The simulated surface ozone concentrations reproduced the observed monthly mean concentrations at sites in East Asia with high R<SUP>2</SUP> values (0.4–0.9), indicating a successful simulation to capture both spatial and temporal variability. We then performed several model simulations with the six IPCC SRES scenarios (A2, A1B, A1FI, A1T, B1, and B2) for the next three periods, 2016–2025 (the 2020s), 2046–2055 (the 2050s), and 2091–2100 (the 2090s). The model results show that the projected changes of the annual daily mean maximum eight-hour (DM8H) surface ozone concentrations in summertime for East Asia are in the range of 2–8 ppb, −3 to 8 ppb, and −7 to 9 ppb for the 2020s, the 2050s, and the 2090s, respectively, and are primarily determined based on the emission changes of NO<SUB>x</SUB> and NMVOC. The maximum increases in the annual DM8H surface ozone and high-ozone events occur in the 2020s for all scenarios except for A2, implying that the air quality over East Asia is likely to get worse in the near future period (the 2020s) than in the far future periods (the 2050s and the 2090s). The changes in the future environment based on IPCC SRES scenarios would also influence the change in the occurrences of high-concentrations events more greatly than that of the annual DM8H surface ozone concentrations. Sensitivity simulations show that the emissions increase is the key factor in determining future regional surface ozone concentrations in the case of a developing country, China, whereas a developed country, Japan would be influenced more greatly by effects of the regional climate change than the increase in emissions.</P> <P><B>Highlights</B></P> <P> <UL> <LI> Change in ozone level is determined by the combination of NO<SUB>x</SUB> and NMVOC emissions. </LI> <LI> Ozone level over East Asia would get worse in the near future (the 2020s) than far future. </LI> <LI> A high-concentration event generally increases and more frequently occurs in the future. </LI> <LI> Change in ozone air quality in a developing country depends more on emissions change. </LI> <LI> Change in ozone air quality in a developed country depends more on climate change. </LI> </UL> </P>

비정질 합금이 나타내는 소성의 원천

이석우,이창면,채수원,김유찬,이재철 대한금속재료학회 2005 대한금속·재료학회지 Vol.43 No.5

Various Cu-Zr bearing monolithic amorphous alloys, exhibiting different stress-strain behaviors, were prepared to investigate the nature of the plasticity shown by theses alloys. Microscopic observation of the quasi-statically compressed Cu_(50)Zr_(43)A1_(7) specimen revealed abundant precipitation of nanocrystallites, while insignificant changes in the microstructure were observed from the Cu_(64)Zr_(36) alloy. Finite element analysis was conducted in order to better understand the role of nanocrystallites in an amorphous matrix on the plasticity of the amorphous alloy. The activation energies for crystallization of the amorphous alloys were measured and correlated with the plasticity of the amorphous alloys. Herein, we report for the first time that the origin of the plasticity of monolithic amorphous alloys lies in the activation energy for crystallization. (Received February 14, 2005)

洪水追跡法에 의한 河道變移豫測(Ⅰ) (理論)

李大澈,이종석,朴昌圭 大田産業大學校 1996 한밭대학교 논문집 Vol.13 No.1

This study is in order to evaluate for the topographic variation by the flood routing method in alluvial channel of the erodibility. Basic equations in natural open channel induced from the control volume for the governing equation with continuity and momentum in water and sediment and the solution for these equations worked out by the finite difference method in numerical analysis. Predictions of the topographic variation leading out from as change direction and rate the various in channel width, changes in bed profiles and radius of curvature. And also, bank erodibility factor induced by the correction coefficient with conditions of bank organization and material properties, and the values used in zero to one from non-erodibility bank to non-cohesive bank, respectively.

Changes of Sugar Composition and Related Enzyme Activities during Fruit Development of Asian Pear Cultivars ‘Niitaka’ and ‘Whangkeumbae’

Jin-Ho Choi,Jang-Jeon Choi,Chang-Seok Bang,Jung-Sup Lee,Dong-Woog Choi,Hye-Sun Cho,Jun Cheul Ahn 한국원예학회 2009 Horticulture, Environment, and Biotechnology Vol.50 No.6

We report on the seasonal changes of soluble sugar accumulation and several enzyme activities related to sugar metabolism, in two Asian pear cultivars (Pyrus pyrifolia) cultivars ‘Niitaka’ and ‘Whangkeumbae’. Soluble sugar content increased as the fruit developed and its total contents in matured fruits were 104.6 and 95.1 ㎎ㆍg?¹ fresh weight for ‘Niitaka’ and ‘Whangkeumbae’, respectively. However, the fructose-glucose-sucrose-sorbitol ratio was not significantly changed. Sorbitol-6-phosphate dehydrogenase activity was maintained at high level in leaves and low in fruits throughout the fruit development, although the enzyme activity highly fluctuated in young and mature fruits. NAD-dependent sorbitol dehydrogenase activity increased sigmoidally in both leaves and fruits during fruit development, and correlated with accumulation of total sugar in fruits. Sucrose synthase and sucrose phosphate synthase (SPS) activities remained low in leaves, but higher with two peak fluctuations in fruits. The change of soluble sugar contents positively correlated with SPS activity, based on the seasonal fluctuation of SPS activity and soluble sugar accumulation.

생약제제인 이공산(異功散)의 Cisplatin 유도 신장독성 보호 및 항산화 효과

Lee, Kyung-Tae,Ahn, Kyoo-Seok,Chang, Sung-Goo,Oh, Soo-Myung,Jung, Jee-Chang 경희대학교 동서의학연구소 1999 INTERNATIONAL SYMPOSIUM ON EAST-WEST MEDICINE Vol.1999 No.1

Kyung-Tae Lee, Kyoo-Seok Ahn¹, Sung-Goo Chang², Soo-Myung Oh²and Jee-Chang Jung²¹College of Pharmacy, ²Oriental Medicine and ³College of Medicine, and East-West Medical Reserch Institute, Kyung Hee University, Seoul, Korea. Preventive and Antioxidative Effects of Crude Drug Preparation(E-kong-san) on Cisplatin Induced Nephrotoxicity. Proceedings of International Symposium on East-West Medicine, Seoul. 201-211, 1999. -Nephroprotective effects of a crude drug-prearation (E-kong-san) were determined from cisplatin on rabbit kidney proximal tubule and human renal cortical cells by MTT assays and sustained glucose consumption on ciplatin-induced human renal cortical tissue. Levels of creatinine and blood ure nitrogen(BUN) in serum after administration of cisplatin(0.75mg/kg,i.p.) to E-kong-san(0.75g/kg/day,p.o.)-pretreated rats were markedly lower compared to those of cisplatin-treated rats. Moreover, the administration of E-kong-san significantly inhibited the loss of body weight of cisplatin injected rts. These findings suggest that E-kong-san on the cisplatin induced nephrotoxicity led us to investigate whether the effect of this water extract was a result of anti-oxidation. E-kong-san showed strong free radical scavenger activities on 1,1-dipheny1-2picrylhydrazil(DPPH) radical and xanthine/xanthine oxidase(XOD) generated superoxide anion radical(O2-). We further studied the effects of E-kong-san on lipid peroxidation in rat liver microsomes induced by enzymatic and nonenzymatic methods. E-kong-san exhibited significant inhibition on both ascorbic acid/Fe2+and ADP/NADPH/Fe3+ induced lipid peroxidation in rat liver microsomes. Based on these results, we suggest that-E-kong-san attenuate the cisplatin induced cytotoxicity and its mechanism can be eplained by antioxidant.

Study on Aging Effect of Adhesion Strength Between Polyimide Film and Copper Layer

Seok‑Bon Koo,Chang‑Myeon Lee,Sang‑Jun Kwon,Jun‑Mi Jeon,Jin‑young Hur,Hong‑Kee Lee 대한금속·재료학회 2019 METALS AND MATERIALS International Vol.25 No.1

This paper experimentally confirmed that the adhesion strength of the copper layer formed on the surface of the polyimidefilm by wet plating greatly changes with the aging time. The adhesion strength of the copper layer showed a rapid increasefrom 4 to 10 h after aging had begun and then converged to a value without a significant change. The adhesion enhancementbetween polyimide film and copper layer by aging is due to the interlocking effect caused by the volume expansion of copperoxide (CuO) formed in the polyimide, the increased mobility of copper particles enlarged by the decrease of impuritiesin the copper layer grain boundaries, and the consequent change of the crystal structure of the copper layer leading to theinternal stress reduction. Such adhesion improvement can be confirmed by the progress of the cohesive failure indicatingthe breakdown of the polyimide film.

Safety and efficacy of dietary supplement (gintonin-enriched fraction from ginseng) in subjective memory impairment: A randomized placebo-controlled trial

Lee Woo-Jin,Shin Yong-Won,Chang Hyeyeon,Shin Hye-Rim,Kim Won-Woo,Jung Seok-Won,Kim Manho,Nah Seung-Yeol 한국한의학연구원 2022 Integrative Medicine Research Vol.11 No.1

Background: Gintonin inhibits β-amyloid production, increases acetylcholine level in the brain, and promotes neurogenesis. We evaluated the efficacy of gintonin-enriched fraction (GEF) in improving the cognitive performance in subjective memory impairment. Methods: In this 8-week, randomized, assessor and participant blinded, placebo–controlled study, participants with subjective memory impairment but preserved cognitive function (Korean Mini-Mental State Examination [K-MMSE] score ≥23) were assigned to GEF 300mg/day or placebo. K-MMSE, Korean versions of the Alzheimer's disease assessment scale, color-word stroop test (K-CWST), clinical dementia rating, and Beck depression inventory-II were evaluated along with the safety profiles. The primary outcome was set as the change in the K-MMSE. Results: Seventy-six participants complete the study protocol. After 8 weeks, there was no inter-group difference in the primary or secondary outcome score changes. However, GEF group showed an improvement in the K-MMSE scores (P= 0.026), and in the number of correct answers in both word reading (P= 0.008) and color reading (P= 0.005) of K-CWST, although only the improvement in the K-CWST scores were higher than the minimum clinically important difference. The frequency of adverse events was comparable between the groups and all were of mild severity. Conclusion: GEF is safe but might not be effective in treating subjective memory impairment within the current study setting. However, GEF showed a trend of improving the global cognition and the frontal executive function. Further large-sized studies with longer follow-up period are warranted. Clinical trial registration: This clinical trial was registered at Clinical Research Information Service of Korea Centers for Disease Control and Prevention: KCT0004636. Background: Gintonin inhibits β-amyloid production, increases acetylcholine level in the brain, and promotes neurogenesis. We evaluated the efficacy of gintonin-enriched fraction (GEF) in improving the cognitive performance in subjective memory impairment. Methods: In this 8-week, randomized, assessor and participant blinded, placebo–controlled study, participants with subjective memory impairment but preserved cognitive function (Korean Mini-Mental State Examination [K-MMSE] score ≥23) were assigned to GEF 300mg/day or placebo. K-MMSE, Korean versions of the Alzheimer's disease assessment scale, color-word stroop test (K-CWST), clinical dementia rating, and Beck depression inventory-II were evaluated along with the safety profiles. The primary outcome was set as the change in the K-MMSE. Results: Seventy-six participants complete the study protocol. After 8 weeks, there was no inter-group difference in the primary or secondary outcome score changes. However, GEF group showed an improvement in the K-MMSE scores (P= 0.026), and in the number of correct answers in both word reading (P= 0.008) and color reading (P= 0.005) of K-CWST, although only the improvement in the K-CWST scores were higher than the minimum clinically important difference. The frequency of adverse events was comparable between the groups and all were of mild severity. Conclusion: GEF is safe but might not be effective in treating subjective memory impairment within the current study setting. However, GEF showed a trend of improving the global cognition and the frontal executive function. Further large-sized studies with longer follow-up period are warranted. Clinical trial registration: This clinical trial was registered at Clinical Research Information Service of Korea Centers for Disease Control and Prevention: KCT0004636.