• Title/Summary/Keyword: 변동성 분석

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Comparative Analysis of Long-term Water Quality Data Monitored in Andong and Imha Reservoirs (안동호와 임하호에서 관측한 장기 수질자료의 비교 분석)

  • Park, Sun-Jae;Choi, Seong-Mo;Park, Jong-Seok;An, Kwang-Guk
    • Korean Journal of Ecology and Environment
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    • v.39 no.1 s.115
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    • pp.21-31
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    • 2006
  • The objectives of this study were to analyze trends of temporal water quality and trophic state in Andong and Imha reservoirs using chemical dataset during 1993 ${\sim}$ 2004, obtained from the Ministry of Environment, Korea. According to long-term limnological analyses, Suspended solids (SS) in Imha Reservoir were 2 ${\sim}$ 8 fold2 greater, than those in SS of Andong Reservoir, and the high solids increased total phosphorus (TP) and biological oxygen demand ($BOD_5$) and decreased the transparency, measured as Secchi depth (SD). Chlorophyll-a (CHL-a) increased little or decreased slightly in the both reservoirs during the high solids, resulting in reduced yields of CHL-a : TP ratios. The deviation analysis of Trophic State Index (TSI) in Imha Reservoir showed that about 70% of TSI (CHL-a)-TSI (SD) and TSI (CHL-a)-TSI(TP) values were less than zero and the lowest values were-60, indicating that influence of inorganic solids (or non-volatile solids) on phytoplankton growth was evident in Imha Reservoir and the impact was greater than that of Andong Reservoir. Inorganic solids in Imha Reservoir resulted in light limitation on phytoplankton growth and thus contributed variations in the relations among three parameters of trophic state index. Especially, seasonal data analysis of nutrients in both reservoirs showed that during the postmonsoon, mean TP concentration was Imha Reservoir greater in than that in Andong Reservoir. The higher TP concentrantion was mainly attributed to increases of inorganic solids from soil erosions and nonpoint source inputs within the watershed. The high inorganic turbidity in Imha Reservoir should be reduced for the conservation of water quality for, especially a tap water supply.

Comparative Study on the Independence of Central bank in Transition Countries: Focused on the Russia, Czech Republic, Poland (체제전환기 국가의 중앙은행 독립성 비교 연구 - 러시아, 체코, 폴란드를 중심으로)

  • Kim, Sang Won
    • Journal of International Area Studies (JIAS)
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    • v.14 no.2
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    • pp.499-524
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    • 2010
  • The purpose of this study is to based on review of theoretical and empirical studies to assess the independence of central banks - the former Socialist republics, including the Russian Federation and Czech, Poland. In addition, the work is expected to clarify whether a link exists between independence and the most important economic indicators such as inflation, economic activity, the budget deficit. And The subject of this study are the formal and actual independence of national banks, as well as limiting factors: political and economic. Background investigation of the problem of independence of central banks from the fact that, according to many economists, it is essential to the successful development of a market economy. The effectiveness of any country's economy due to currency volatility, low inflation, high reliability of the banking system, etc. As far as the independence of monetary regulation contributes to these goals - one of the most actively debated issues in the world of economic theory and practice for a long time. The issue of central bank independence is extremely important for Russia, Czech, Poland. In the near future to the central bank has important tasks, among which are the transition to inflation targeting in the rejection of significant intervention in the foreign exchange market, as well as improving the sustainability of the national banking system. Transparency and independence of the Bank of Russia, Czech Republic, Poland, in my view, should be an important factor in achieving these goals. The countries of Czech Republic, Poland have already made a number of steps to bring the status of their banks to the European standards. Many other developing countries are also in the process of reforming their central banks and the improving conditions of their functioning. However, despite the fact that as a model for reform used by the central banks of countries with developed market economies, central banks in developing countries are still yet deprived of the legal, economic and political independence. A different situation exists in transition space. Because of significant differences in the views of the authorities in transition republics at the necessary level of independence of central banks and the exchange rate and monetary policy reform of monetary management in these countries led to different results.

Environmental Studies in the Lower Part of the Han River - IX. Succession of Epilithic Diatoms on the Artificial Substrate and Factor Analysis (한강하류의 환경학적연구 - IX. 인공기질을 이용한 부착돌말류의 천이와 요인분석)

  • Park, Sung-Hwan;Lee, Jin-Hwan
    • Korean Journal of Environmental Biology
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    • v.25 no.1
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    • pp.16-26
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    • 2007
  • To study the succession of epilithic diatoms on the artificial substrate, we investigated environmental factors and the diatom assemblages biweekly from Mar. 2004 to Feb. 2005 at 2 stations in the lower part of the Han River. A total of 60 taxa, representing 2 orders, 3 suborders, 8 families, 17 genera, 51 species, 7 varieties and 2 forms were identified, and mean number of species were 19 species in spring, 20 in summer, 22 in autumn and 22 in winter. Standing crops of epilithic diatoms varied extensively by months and stations; mean values of those were $3.2{\times}10^4$ cells $cm^{-2}$ in spring, $1.9{\times}10^4$ in summer, $1.7{\times}10^4$ in autumn and $1.8{\times}10^5$ in winter. Chlorophyll a concentrations were also similarly showed as variations of the diatom assemblages. Succession of the diatoms in St. 1 was as follows; Melosira varians, Fragilaria capucina, Cyclotella comta, Nitzschia palea in spring, Fragilaria capucina in summer, Aulacoseira granulata var. angustissima in autumn, Aulacoseira granulata var. angustissima and Melosira varians, Cymbella minuta in winter. In station 2, Aulacoseira granulata and Nitzschia palea dominated in spring as a pioneer in early stage of succession, Fragilaria capucina in summer, and Nitzschia palea in winter. According to Canonical Correspondence Analysis (CCA), there showed similar to that of succession of epilithic diatoms within St. 1 and St. 2, and they were not changed by stations but seasons. Nitzschia palea belonged to saprophilous taxa correlated with nitrogen sources and suspended solids. Meanwhile, Fragilaria capucina and Cymbella minuta included in xenosaprobic taxa show correlation with DO and pH. Eurysaprobic taxa correlated with all environmental factors.

Analysis of the Characteristics of Water Quality Difference Occurring between High Tide and Low Tide in Masan Bay (만조와 간조시 마산만 수질의 농도차 발생 특성의 분석)

  • Yoo, Youngjin;Kim, Sung Jae
    • Journal of Wetlands Research
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    • v.21 no.2
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    • pp.102-113
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    • 2019
  • Slack-tide sampling was carried out at 6 stations at high and low tide for a tidal cycle during spring tide of the early summer (June) and summer (July, August) of 2016 to determine the difference of water quality according to tide in Masan Bay, Korea. The mixing regime of all the water quality components investigated was well explained through the correlation with SAL. In the early summer and summer, TURB, DSi and NNN which mainly flow into the bay from the streams and SS, COD, AMN and $H_2S$ which mainly indicate the internal sink and source materials have a property of conservative mixing and non-conservative mixing, respectively. The conservative mixing showed a good linear relationship of the water quality between high and low tide, and the non-conservative mixing showed a variation of different pattern each other. Factor analysis performed on the concentration difference data sets between high and low tide helped in identifying the principal latent variables for them. In early summer, multiple effects (tidal action, natural influx and internal sinks and sources etc.) acted in combination for the differences to be distributed evenly in four factors (VF1~4), since there were few allochthonous inputs as a low-water season. On the contrary, in summer, the parameters showing large concentration difference at ST-1 affected by stream water were concentrated in one factor (VF1) and clearly distinguished from the parameters affected by the internal sinks and sources. In fact, there is no estuary (bay) that always maintains steady state flow conditions. The mixing regime of an estuary might be changed at any time due to the change of flushing time, and furthermore the change of end-member conditions due to the internal sinks and sources makes the occurrence of concentration difference inevitable. Therefore, when investigating the water quality of the estuary, it is necessary to take a sampling method considering the tide to obtain average water quality data.

A Study on Risks and Returns Using A Housing Capital Asset Pricing Model (CAPM): the Case of Three Gangnam Districts Apartment Market in Seoul (주택 자본자산가격결정모형(Capital Asset Pricing Model)을 활용한 위험과 수익 분석: 서울 강남 3개구 아파트시장의 경우)

  • Lee, Jong-Ah;Jeong, Jun-Ho
    • Journal of the Economic Geographical Society of Korea
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    • v.13 no.2
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    • pp.234-252
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    • 2010
  • This paper examines the tendency of housing assets to become increasingly quasi-financial assets by analyzing the relationships between risks and returns in three Gangnam districts (Gangnam-gu, Seocho-gu and Songpa-gu) apartment markets in Seoul, especially for the apartments to be reconstructed, capitalizing upon some capital asset pricing models (CAPM). A single factor CAPM model shows positive relationships between risks and returns regardless of the types of apartments in three Gangnam districts. Multi-factors CAPM models also confirm that the market and SMB (small minus big) factors are positively related to the rate of returns regardless of the types of apartments. However, the unsystematic risk factor is found to be statistically positive especially for the apartments to be reconstructed, while the momentum factor is dependent upon the regression models used. An analysis on some portfolios classified by the size of apartments and price volatility and/or beta values suggests that there are the positive linear relationships between risks and returns and the SMB factor is clearly found to be significant in determining the rate of returns. In particular, housing assets are highly highlighted as investment goods and/or quasi financial assets for the apartments to be constructed in the Gangnam housing.

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Topographical Chemical Properties of Paddy Soils in Gyeongnam Province (경남지역 논토양 지형과 화학성의 관계)

  • Lee, Young-Han;Sonn, Yeon-Kyu;Lee, Seong-Tae;Heo, Jae-Young;Kim, Min-Keun;Kim, Eon-Seok;Song, Won-Doo;Zhang, Yong-Sun;Jeon, Weon-Tai;Ok, Yong-Sik
    • Korean Journal of Soil Science and Fertilizer
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    • v.45 no.2
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    • pp.143-148
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    • 2012
  • Sustainable agriculture requires reliable information on the spatial distribution of the soil chemical properties for effective management of paddy fields. In order to provide adequate soil nutritional information for environmental-friendly agriculture, we investigated the soil chemical properties for 260 paddy soils sampled in Gyeongnam Province from 1999 to 2011 by four years of interval. Soil chemical properties of pH, organic matter, available phosphate and silicate, exchangeable potassium, calcium, and magnesium contents were analyzed. The pH value, organic matter, available phosphate and silicate, and exchangeable calcium and magnesium in paddy soils were significantly elevated in 2011 compared to 1999. The excessive levels of organic matter and available phosphate in paddy soils were detected in 2011. The soil available phosphate was highest in mountain foot-slope (p<0.05) and the soil organic matter was highest in diluvial terrace (p<0.05). It revealed that the soil available phosphate was the responsible factor for the differentiation of soil chemical properties by the topography in paddy soils.

Calibration Kit for 4-Port Horizontal/Vertical Probing (4-포트 수평/수직 겸용 프로브용 교정키트)

  • Kim, Taeho;Kim, Jonghyeon;Kim, Sungjun;Kim, Kwangho;Pu, Bo;Nah, Wansoo
    • The Journal of Korean Institute of Electromagnetic Engineering and Science
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    • v.25 no.5
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    • pp.559-575
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    • 2014
  • In this paper, we propose a horizontal/vertical calibration kit for calibrating a vector network analyzer(VNA) to measure the vertical connector pin. If the conventional calibration kit is used, we should change the arm for a probe or need an assistant device and it takes a long time. In addition there is a risk of precision degradation caused by the position change of the probe tip sensitive to the surroundings. We suggest a 4-port vertical calibration kit to make up for the aforementioned shortcomings. The calibration kit was manufactured for the SOLT calibration method. 'Short', 'Open', and 'Load' are available in the horizontal plane, 'Thru' is available not only in the horizontal plane on the two planes of a PCB, but in the vertical plane between the two planes according to the positions of the probes. We complemented the conventional calibration kit to make a vertical calibration kit to be used for the vertical measurement method. We compared and analysed their reflection/transfer characteristics of the SOLT calibration standards of the proposed calibration kit and conventional one, we get a ${\pm}0.1$ dB differences of transfer characteristics in the range from 300 kHz to 8.5 GHz. In order to demonstrate usefulness, and we performed a case study for horizontal and vertical cases, and compared the results of the proposed calibration kit and conventional one.

Analysis of Budget Trends related to Creation of Urban Park in Seoul - Focusing on Budgetary Document - (서울시 도시공원조성예산 변동 추세 - 예산서를 중심으로 -)

  • Ko, Ha-jung
    • Journal of the Korean Institute of Landscape Architecture
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    • v.48 no.3
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    • pp.1-11
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    • 2020
  • Urban parks are important spaces of ecological and socio-cultural value to citizens who lead busy lives in increasingly complex and densely populated megalopolises. However, creating and maintaining city parks takes the will of the authorities to put it into practice and provide the attendant financial resources. That explains why we are focused on the budget aspects for the Seoul Metropolitan City in relation to creating park spaces. Our findings were as follows: 1) The overall city budget has steadily increased, but the budget allocated to Green Seoul Bureau and new park development has decreased since 2011. 2) As for elected officials, the budget grew during the time of the first, third, and fourth mayors as the creation of parks was considered to be a major priority, but after the sixth popularly elected mayor, the budget was sharply cut. 3) About 10% of the budget was allocated to the parks managed by the self-governing districts, compared to the ones under the direct management of the city. Furthermore, the analysis of the average annual budget for each park and how long (in terms of year) the budget for each park is invested showed that it was classified into three different types of category. Local governments adhere to the principle that their budget must be compiled and expended for a single year, which makes it hard to establish and push ahead with a long-term plan. However, as parks and green areas should not be approached from a short-term perspective for performance but from a long-term perspective, securing the consistent amount of budget is essential. This study has significance in that it attempted to analyze the budget issues related to parks, which has not been studied in depth so far, but the subject in this paper was limited to the budget for Green Seoul Bureau. Therefore, further research is needed because the parks managed by the self-governing districts were not considered.

Survey Study on Radioactivity of Domestic Fishery Product (국내 시중 유통 수산물에 대한 방사능 농도 조사)

  • Kim, Chang-Jong;Lim, Chung-seop;Lee, Wanno;Jang, Mee;Ji, Young-Yong;Chung, Kun-Ho;Kang, and Mun-Ja
    • Korean Journal of Food Science and Technology
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    • v.47 no.6
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    • pp.789-792
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    • 2015
  • Samples of fishery products were tested for radioactivity by using the intake frequency data from Korea Health Statistics. The radioactivity of $^{40}K$, $^{137}Cs$, $^{134}Cs$, and $^{131}I$ was analyzed using gamma spectrometry with a simplified sample pre-treatment procedure. The radioactivity range for $^{40}K$ was 21.9-3050 Bq/kg, whereas the radioactivities of $^{137}Cs$, $^{134}Cs$, and $^{131}I$ were under minimum detectable activity which were in the range of 0.140-1.97, 0.0900-1.89 and 0.124-1.94 Bq/kg, respectively, for the three species. The results suggest that the Fukushima accident did not have a significant impact on domestic fishery products, which were analyzed during the period from 2013 to 2015. Additionally, there seemed to be no significant impact of additional exposure dose by the analyzed radionuclides.

A Study on the Construction Cost Index for Calculating Conceptual Estimation : 1970-1999 (개략공사비 산출을 위한 공사비 지수 연구 : 1970-1999)

  • Nam, Song Hyun;Park, Hyung Keun
    • KSCE Journal of Civil and Environmental Engineering Research
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    • v.40 no.5
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    • pp.527-534
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    • 2020
  • A significant factor in construction work is cost. At early- and advanced-stage design, costs should be calculated to derive realistic cost estimates according to unit price calculation. Based on these estimates, the economic feasibility of construction work is assessed, and whether to proceed is determined. Through the Korea Institute of Civil Engineering and Building Technology, the construction cost index has been calculated by indirect methods after both the producer price index and construction market labor have been reprocessed to easily adjust the price changes of construction costs in Korea, and the Institute has announced it since 2004. As of January 2000, however, the construction cost index was released, and this has a time constraint on the correction and use of past construction cost data to the present moment. Variables were calculated to compute a rough construction cost that utilized past construction costs through surveys of the producer price index and the construction market labor force consisting of the construction cost index. After significant independent variables among the many variables were selected through correlation analysis, the construction cost index from 1970 to 1999 was calculated and presented through multiple regression analysis. This study therefore has prominent significance in terms of proposing a method of calculating rough construction costs that utilize construction costs that pre-date the 2000s.