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A Study on the Comovements and Structural Changes of Global Business Cycles using MS-VAR models (MS-VAR 모형을 이용한 글로벌 경기변동의 동조화 및 구조적 변화에 대한 연구)

  • Lee, Kyung-Hee;Kim, Kyung-Soo
    • Management & Information Systems Review
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    • v.35 no.3
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    • pp.1-22
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    • 2016
  • We analyzed the international comovements and structural changes in the quarterly real GDP by the Markov-switching vector autoregressive model (MS-VAR) from 1971(1) to 2016(1). The main results of this study were as follows. First, the business cycle phenomenon that occurs in the models or individual time series in real GDP has been grasped through the MS-VAR models. Unlike previous studies, this study showed the significant comovements, asymmetry and structural changes in the MS-VAR model using a real GDP across countries. Second, even if there was a partial difference, there were remarkable structural changes in the economy contraction regime(recession), such as 1988(2) ending the global oil shock crisis and 2007(3) starting the global financial crisis by the MS-VAR model. Third, large-scale structural changes were generated in the economic expansion and/or contraction regime simultaneously among countries. We found that the second world oil shocks that occurred after the first global oil shocks of 1973 and 1974 were the main reasons that caused the large-scale comovements of the international real GDP among countries. In addition, the spillover between Korea and 5 countries has been weak during the Asian currency crisis from 1997 to 1999, but there was strong transmission between Korea and 5 countries at the end of 2007 including the period of the global financial crisis. Fourth, it showed characteristics that simultaneous correlation appeared to be high due to the country-specific shocks generated for each country with the regime switching using real GDP since 1973. Thus, we confirmed that conclusions were consistent with a number of theoretical and empirical evidence available, and the macro-economic changes were mainly caused by the global shocks for the past 30 years. This study found that the global business cycles were due to large-scale asymmetric shocks in addition to the general changes, and then showed the main international comovements and/or structural changes through country-specific shocks.

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A STUDY ON THE FIVE ELEMENT THEORY INTODUCED (<황제내경(黃帝內經)>에 유입(流入)된 오행학설(五行學說)에 관(關)한 연구(硏究))

  • Kim, Boo-Hwan;Park, Hyun-Kook
    • The Journal of Dong Guk Oriental Medicine
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    • v.1
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    • pp.161-191
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    • 1992
  • The purpose of this study is how have the form and theory of the five element theory in the (黃帝內徑) by the investigation of the course of the course of the five element introduced the ancient oriental medicine from ancient oriental philosophy. The following results were obtained. 1. The five elements in (尙書) meaned the uses of water, fire, earth, wood, metal which were important in living. Because these had very important meaning in ancient political and economic society, emphasized to big law(洪範) 2. The five elements in (左傳) and (國語) mean the five uses too, and there are the phases of "five win metal"(火勝金) and "wather win fire"(水勝火), but these only meaned the physical interrelation. 3. In the five circulating factor theory made by Chu Yen(鄒衍) which have the attribute of the five elements, he more reasonably had argued human affairs like that a dynasty become different in step with the circulating five favors. There is the regular annual policy in the (呂氏春秋) which closely connected nature and human living, and attached the various colors, animals, visceras, flavors, sounds, the sexagenary cycle and so on to the five elements. 4. In the (春秋繁露) writed in fore-period of Han(漢) dynasty, the interactions of the five elements are concretely applicated to policy, Dong Jung Soe(童仲舒) had discrived the interactions of the five elements by Dong Lyu Sang Dong theory(同類相動說) and the misfortune theory(災異說), emphasized the sympathy of nature and human. Thought there is many content which are superstitious and contradictory, I concider which that affcted many effects in the formation of five element theory of oriental medicine. In the (淮南子) the order of matters were explained by the five element theory too, as the interrelations of the five elements were explained by the sexagenary ctcle, I assume that the bud of O-Un theory(五運理論). And there was not founded the fullscale intriduction of the five element theory in the Ma Wang Tye(馬王堆) excavated finds, the Mu Yyi medical writings formed the dynasty(武威漢代醫簡) and the documents about Pyun Jak(偏鵲) and Sun U Ie(淳于意). 5. The application of the five element theory in the (Whang Di Nei Qing) (黃帝內徑) is devided into the attachement to the five elements, the interelations of the five elments, and Un Gi theery(運氣論). In the attachment to the five elemeant theory, it made the attachment of the five viseras of (今文尙書) party a standard and attached the sections of a human body, the whole internal organs of sense, the five colors, the five flavors and the five sounds and so on to the five elements. It put to use by means of the apllivation of the interrelation of the five elements in the transferations of the diseases and the relative severeness of a disease in step with change of time and season. Un Gi theory(運氣論) which synthesized by the attachment to the five elements, the inter-relations of the five elements and the climate which observerd from ancient times systematically argued the effects of weather to human. 6. The application of the five elements theory in (黃帝內徑) have the significant what had get rid of irrational factors like that the emotion and action of human could to influense the weather, what had been formes more rational thingking by the obesrvation of human and nature. It is required more reserches about the possibility of the formation of the doctrinal faction bt the geographical effect of the Yon, Je(燕,薺) region, the application of the five element theory in other ancient medical books and the relationship of the five element theory and Yin Yang(陰陽)

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Application of ECVAM as a Indicator for Monitoring National Environment in Korea (국토환경 모니터링 지표로서의 국토환경성평가지도 활용방안)

  • Kim, Eunyoung;Jeon, Seong-Woo;Song, Wonkyong;Kwak, Jaeryun;Lee, June
    • Journal of Environmental Policy
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    • v.11 no.2
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    • pp.3-16
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    • 2012
  • Objectives of the Korean Environmental Conservation Value Assessment Map (ECVAM) is to evaluate environmental value used in comprehensive environmental information in order to encourage eco-friendly land use and management. The first research was conducted in 2001 to establish the evaluation items and the criteria of the ECVAM, and the first nationwide map was established in the period of 2003 to 2005. The maps are updated annually to reflect environmental changes of land. The evaluation items and the criteria have been modified based on feasibility studies to improve the accuracy of the maps. This study re-evaluated the ECVAMs from 2005 to 2010 with criteria used in current environment and analyzed the changes in the area of the maps in 6 years. This is also an investigation on the maps whether they are appropriate as an index for sustainable environmental monitoring. The result shows that the 1st grade level of the ECVAM area with the highest conservation value had been expanding since 2005. These changes were analyzed in terms of updating the 4th Forest Map (2008) produced once every 10 years, reflecting the new legal protected areas such as Baekdudaegan Protected Area(2010), and the environmental/ecological assessment items such as the National Ecological Network (2009). This mean the ECVAM are a monitoring index that integrates individual environmental indexes including the increase of forest age and diameter due to sustainable management of forest areas, and the change of conservation areas. Therefore, ECVAM can be used as a new index integrating national environmental indicators for monitoring changes of national environment and policy. In order to utilize the ECVAM, improving accuracy and reducing renewal cycle time of thematic maps are required.

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Effects of Some Environmental Factors on the Germination of Seeds in Ambrosia artemisiifolia var. elatior (몇가지 환경요인이 돼지풀의 종자발아에 미치는 영향)

  • Cha, Seung-Hee;Kim, Won-Hee;Kim, Jong-Hong
    • The Korean Journal of Ecology
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    • v.25 no.3 s.107
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    • pp.163-170
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    • 2002
  • In order to analyze the life cycle of A. artemisiifolia var. elatior dormancy and some environmental factors inducing germination of the seeds were examined. The results were as follows : Dormancy of fertile seeds was broken in part within a month after seed collection in case of adequate moisture and alternating temperature was also effective in breaking dormancy. The temperature range, which allow germination was $12^{\circ}C{\sim}32^{\circ}C$. Optimum temperature for germination was $24^{\circ}C$. The seed of A. artemisiifolia var. elatior was light-independent. The difference of storage period appeared to have no particular effect on the viability of seeds at any time during the 9-month storage period. In the increasing temperature(IT) regime, A. artemisiifolia var. elatior seeds started to germinate at $16^{\circ}C$, showing the higher temperature the greater germination rate : the final germination percentage was 99.34%. On the other hand, in the decresing temperature(DT) regime, seeds began to germinate at $20^{\circ}C$ with the 1.34% germination. An induced dormancy occurred at $12^{\circ}C$ making the 5.34% final germination in the DT regime. Low temperature was more effective to break dormancy than higher temperature. Seeds of A. artemisiifolia var. elatior seems to be germinated in mid to late autumn or germination delayed until following spring. The above results suggest these variation of germination response in diverse environmental factors seems to be a physiological strategy to maintain their existence and to reproduce in the extreme thermal variation.

Continuity Simulation and Trend Analysis of Water Qualities in Incoming Flows to Lake Paldang by Log Linear Models (로그선형모델을 이용한 팔당호 유입지류 수질의 연속성 시뮬레이션과 경향 분석)

  • Na, Eun-Hye;Park, Seok-Soon
    • Korean Journal of Ecology and Environment
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    • v.36 no.3 s.104
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    • pp.336-343
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    • 2003
  • Two types of statistical models, simple and multivariate log linear models, were studied for continuity simulation and trend analysis of water qualities in incoming flows to Lake Paldang. Water quality is a function of one independent variable (flow) in the simple log linear model, and of three different variables (flow, time, and seasonal cycle) in multivariate model. The independent variables act as surrogate variables of water quality in both models. The model coefficients were determined by the monthly data. The water qualities included 5-day Biochemical Oxygen Demand ($BOD_5$), Total Nitrogen (TN), and Total Phosphorus (TP) measured from 1995 to 2000 in the South and the North branches of Han River and the Kyoungan Stream. The results indicated that the multivariate model provided better agreements with field measurements than the simple one in a31 attempted cases. Flow dependency, seasonality, and temporal trends of water quality were tested on the determined coefficients of the multivariate model. The test of flow dependency indicated that BOD concentrations decreased as the water flow increased. In TN and TP concentrations, however, there were no discernible flow effects. From the temporal trend analyses, the following results were obtained: 1) no trends on BOD at all three upstreams, 2) increase on TN at the South Branch and the Kyoungan Stream, 3)decrease on TN at the North Branch,4) no trends on TP at the North and the South Branches and 5) increase on TP at the Kyoungan Stream by 3 to 8% per years. The seasonality test showed that there were significant seasonal variations in all three water qualities at three incoming flows.

Effect of Trichostatin A on Anti HepG2 Liver Carcinoma Cells: Inhibition of HDAC Activity and Activation of Wnt/β-Catenin Signaling

  • Shi, Qing-Qiang;Zuo, Guo-Wei;Feng, Zi-Qiang;Zhao, Lv-Cui;Luo, Lian;You, Zhi-Mei;Li, Dang-Yang;Xia, Jing;Li, Jing;Chen, Di-Long
    • Asian Pacific Journal of Cancer Prevention
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    • v.15 no.18
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    • pp.7849-7855
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    • 2014
  • Purpose: To investigate the effect of deacetylase inhibitory trichostatin A (TSA) on anti HepG2 liver carcinoma cells and explore the underlying mechanisms. Materials and Methods: HepG2 cells exposed to different concentrations of TSA for 24, 48, or 72h were examined for cell growth inhibition using CCK8, changes in cell cycle distribution with flow cytometry, cell apoptosis with annexin V-FTIC/PI double staining, and cell morphology changes under an inverted microscope. Expression of ${\beta}$-catenin, HDAC1, HDAC3, H3K9, CyclinD1 and Bax proteins was tested by Western blotting. Gene expression for ${\beta}$-catenin, HDAC1and HDAC3 was tested by q-PCR. ${\beta}$-catenin and H3K9 proteins were also tested by immunofluorescence. Activity of Renilla luciferase (pTCF/LEF-luc) was assessed using the Luciferase Reporter Assay system reagent. The activity of total HDACs was detected with a HDACs colorimetric kit. Results: Exposure to TSA caused significant dose-and time-dependent inhibition of HepG2 cell proliferation (p<0.05) and resulted in increased cell percentages in G0/G1 and G2/M phases and decrease in the S phase. The apoptotic index in the control group was $6.22{\pm}0.25%$, which increased to $7.17{\pm}0.20%$ and $18.1{\pm}0.42%$ in the treatment group. Exposure to 250 and 500nmol/L TSA also caused cell morphology changes with numerous floating cells. Expression of ${\beta}$-catenin, H3K9and Bax proteins was significantly increased, expression levels of CyclinD1, HDAC1, HDAC3 were decreased. Expression of ${\beta}$-catenin at the genetic level was significantly increased, with no significant difference in HDAC1and HDAC3 genes. In the cytoplasm, expression of ${\beta}$-catenin fluorescence protein was not obvious changed and in the nucleus, small amounts of green fluorescence were observed. H3K9 fluorescence protein were increased. Expression levels of the transcription factor TCF werealso increased in HepG2 cells following induction by TSA, whikle the activity of total HDACs was decreased. Conclusions: TSA inhibits HDAC activity, promotes histone acetylation, and activates Wnt/${\beta}$-catenin signaling to inhibit proliferation of HepG2 cell, arrest cell cycling and induce apoptosis.

A Dynamic Behavior Evaluation of the Curved Rail according to Lateral Spring Stiffness of Track System (궤도시스템의 횡탄성에 따른 곡선부 레일의 동적거동평가)

  • Kim, Bag-Jin;Choi, Jung-Youl;Chun, Dae-Sung;Eom, Mac;Kang, Yun-Suk;Park, Yong-Gul
    • Proceedings of the KSR Conference
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    • 2007.11a
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    • pp.517-528
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    • 2007
  • Domestic or international existing researches regarding rail damage factors are focused on laying, vehicle conditions, driving speed and driving habits and overlook characteristics of track structure (elasticity, maintenance etc). Also in ballast track, as there is no special lateral spring stiffness of track also called as ballast lateral resistance in concrete track, generally, existing study shows concrete track has 2 time shorter life cycle for rail replacement than ballast track due to abrasion. As a result of domestic concrete track design and operation performance review, concrete track elasticity is lower than track elasticity of ballast track resulting higher damage on rail and tracks. Generally, concrete track has advantage in track elasticity adjustment than ballast track and in case of Europe, in concrete track design, it is recommended to have same or higher performance range of vertical elastic stiffness of ballast track but domestically or internationally review on lateral spring stiffness of track is very minimal. Therefore, through analysis of service line track on site measurement and analysis on performance of maintenance, in this research, dynamic characteristic behaviors of commonly used ballast and concrete track are studied to infer elasticity of service line track and experimentally prove effects of track lateral spring stiffness that influence curved rail damage as well as correlation between track elasticity by track system and rail damage to propose importance of appropriate elastic stiffness level for concrete and ballast track.

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Expression of CsRCI2s by NaCl stress reduces water and sodium ion permeation through CsPIP2;1 in Camelina sativa L.

  • Kim, Hyun-Sung;Lim, Hyun-Gyu;Ahn, Sung-Ju
    • Proceedings of the Korean Society of Crop Science Conference
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    • 2017.06a
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    • pp.194-194
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    • 2017
  • Camelina (Camelina sativa L.) is a potential bio-energy crop that has short life cycle about 90 days and contains high amount of unsaturated fatty acid which is adequate to bio-diesel production. Enhancing environmental stress tolerance is a main issue to increase not only crop productivity but also big mass production. CsRCI2s (Rare Cold Inducible 2) are cold and salt stress related protein that localized at plasma membrane (PM) and assume to be membrane potential regulation factor. These proteins can be divide into C-terminal tail (CsRCI2D/E/F/G) or no-tail group (CsRCI2A/B/C/H). However, function of CsRCI2s are less understood. In this study, physiological responses and functional characterization of CsRCI2s of Camelina under salt stress were analyzed. Full-length CsRCI2s (A/B/E/F) and CsPIP2;1 sequences were confirmed from Camelina genome browser. Physiological investigations were carried out using one- or four-week-old Camelina under NaCl stress with dose and time dependent manner. Transcriptional changes of CsRCI2A/B/E/F and CsPIP2;1 were determined using qRT-PCR in one-week-old Camelina seedlings treated with NaCl. Translational changes of CsRCI2E and CsPIP2;1 were confirmed with western-blot using the antibodies. Water transport activity and membrane potential measurement were observed by cRNA injected Xenopus laevis oocyte. As results, root growth rate and physiological parameters such as stomatal conductance, chlorophyll fluorescence, and electrolyte leakage showed significant inhibition in 100 and 150 mM NaCl. Transcriptional level of CsPIP2;1 did not changed but CsRCI2s were significantly increased by NaCl concentration, however, no-tail type CsRCI2A and CsRCI2B increased earlier than tail type CsRCI2E and CsRCI2F. Translational changes of CsPIP2;1 was constitutively maintained under NaCl stress. But, accumulation of CsRCI2E significantly increased by NaCl stress. CsPIP2;1 and CsRCI2A/B/E/F co-expressed Xenopus laevis oocyte showed decreased water transport activity as 61.84, 60.30, 62.91 and 76.51 % at CsRCI2A, CsRCI2B, CsRCI2E and CsRCI2F co-expression when compare with single expression of CsPIP2;1, respectively. Moreover, oocyte membrane potential was significantly hyperpolarized by co-expression of CsRCI2s. However, higher hyperpolarized level was observed in tail-type CsRCI2E and CsRCI2F than others, especially, CsRCI2E showed highest level. It means transport of $Na^+$ ion into cell is negatively regulated by expression of CsRCI2s, and, function of C-terminal tail is might be related with $Na^+$ ion influx. In conclusion, accumulation of NaCl-induced CsRCI2 proteins are related with $Na^+$ ion exclusion and prevent water loss by CsPIP2;1 under NaCl stress.

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Nutrients and Decomposition Rate Accumulated on Soil Layers in Quercus mongolica Forest of Mt. Songnisan National Park (속리산 신갈나무림의 토양층별 영양염류 함량과 분해율)

  • 강상준;한동열
    • Korean Journal of Environmental Biology
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    • v.22 no.1
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    • pp.93-100
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    • 2004
  • The content of nutrients such as organic carbon, nitrogen, phosphorus and potassium accumulated on soil layers in Quercus mongolica forest of Mt. Songnisan National Park located at central part of Korea was measured, and then the decomposition constants and decay times of the nutrients were also calculated by the negative coefficience model(O1son,1963). The quantities of organic carton of L-layer, F-layer, H-layer and $A_1$-layer of the forest stand were 231.25 g $m^{-2}$, 291.50 g $m^{-2}$,166.91 g$m^{-2}$ and 174.51 g $m^{-2}$, respectively. The content of organic carbon and nitrogen contained in L-layer and F-layer showed large quantity than those of other layers. The large amount of phosphorus and potassium was observed at the B-layer and $A_1$-layer. On the other hand, the decomposition constants(k) of soil organic matter were as follows : organic carbon (k = 0.3657), nitrogen (k = 0.3319), phosphorus (k = 0.2050), and potassium (k = 0.0934) and the decay times needed to 99% decomposition of nutrients in soil organic matter were as follows: that is, organic carton, nitrogen, phosphorus and potassium was 13.94 years, 15.18 years, 24.79 years, and 55.11 years, respectively. By the application of Turbo Pascal Program on the inflowed and outflowed nutrients to the forest stand,87.67% (714.84 g $m^{-2}$) of organic carbon inflowed was decomposed and 81.62% (1,594.62 g $m^{-2}$) of organic carbon accumulated was decomposed. And 84.98% of nitrogen inflowed was decomposed and 70.26% of nitrogen accumulated was also decayed.50.00% of phosphorus input and 40.31% of potassium input were decomposed, and 38.40% of phosphoyus and 33.03% of potassium accumulated were also decayed, respectively. Therefore, it is suggested that Quercus mongolica forest surveyed in the present study is maintaining in steady state because input and output amounts of nutrients is shown a similar pattern.

AN EXPERIMENTAL STUDY ON THE TENSILE STRENGTH OF POSTERIOR RESIN-BASED COMPOSITES (구치부 복합레진의 인장강도에 관한 실험적 연구)

  • Kim, Jae-Gon;Lee, Yong-Hee;Yang, Cheol-Hee;Baik, Byeong-Ju
    • Journal of the korean academy of Pediatric Dentistry
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    • v.28 no.3
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    • pp.464-470
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    • 2001
  • The purpose of this study was to evaluate the tensile strength of light-cured restorative posterior resin-based composites. Five commercially available light-cured composites(Denfil : DF, P60 : PS, Unifil S : US, Z100 : ZH, Z250 : ZT) were used. Rectangular tension test specimens were fabricated in a teflon mold giving 5mm in gauge length and 2mm in thickness. Specimens were subjected to the 5,000 thermal cycles between $5^{\circ}C$ and $55^{\circ}C$ and the immersion time in each bath was 15 second per cycle. Tensile testing was carried out with Instron at a crosshead speed of 0.5mm/min and fractured surface were observed with scanning electron microscope. The obtained results were summarized as follows; 1. The tensile strength of PS was highest. PS was significantly higher than DF, US and ZH(p<0.05) but in the case of ZT was similar to PS(p>0.05). 2. The tensile strength DF was lowest. DF was significantly lower than PS, US, ZH and ZT(p<0.05). 3. The tensile strength of US and ZH were significantly lower than PS and ZT(p<0.05). but were significantly higher than DF(p<0.05). The tensile strength of US and ZH were similar(p>0.05).

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