• Title/Summary/Keyword: ENVIRONMENTAL INTERPRETATION

Search Result 608, Processing Time 0.021 seconds

Two-Dimensional Magnetotelluric Interpretation by Finite-Element Method (유한요소법에 의한 MT 법의 2차원 해석)

  • Kim, Hee-Joon;Choi, Ji-Hyang;Han, Nu-Ree;Lee, Seong-Kon;Song, Yoon-Ho
    • Geophysics and Geophysical Exploration
    • /
    • v.11 no.2
    • /
    • pp.85-92
    • /
    • 2008
  • Magnetotelluric (MT) methods are widely applied as an effective exploration technique to geothermal surveys. Two-dimensional (2-D) analysis is frequently used to investigate a complicated subsurface structure in a geothermal region. A 2-D finite-element method (FEM) is usually applied to the MT analysis, but we must pay attention to the accuracy of so-called auxiliary fields. Rodi (1976) proposed an algorithm of improving the accuracy of auxiliary fields, and named it as the MOM method. Because it introduces zeros into the diagonal elements of coefficient matrix of the FEM total equation, a pivoting procedure applied to the symmetrical band matrix makes the numerical solution far less efficient. The MOM method was devised mainly for the inversion analysis, in which partial derivatives of both electric and magnetic fields with respect to model parameters are required. In the case of forward modeling, however, we do not have to resort to the MOM method; there is no need of modifying the coefficient matrix, and the auxiliary fields can be elicited from the regular FEM solution. The computational efficiency of the MOM method, however, can be greatly improved through a sophisticated rearrangement of the total equation.

Detection of Buried Objects and Imaging of Subsurface Resistivity Structure using Loop-Loop EM Methods (소형루프 전자탐사법을 이용한 매설물 탐지 및 지하 전기비저항 영상화)

  • Seol Soon Jee;Song Yoonho;Cho Seong-Jun;Son Jeong-Sul;Chung Seung-Hwan
    • Geophysics and Geophysical Exploration
    • /
    • v.5 no.4
    • /
    • pp.309-315
    • /
    • 2002
  • Conventional electromagnetic (EM) method using small loops as a source and receiver has been used in detection of conductive buried objects like a metal detector or in qualitative estimation of the subsurface conductivity variation. Recently, however, since detection of buried objects and imaging of the subsurface conductivity distribution in a relatively conductive area are in a high demand for environmental and engineering purposes, the quantitative interpretation technique of EM data is actively studied. In this regard, we introduce a brief principle of EM survey and show an example of the detection of buried conductive material and imaging of the subsurface conductivity distribution based on data measured at a test survey area. Through this study, we show that multi-frequency EM surveys using small loops may be a good solution to give quick and detail information of subsurface in a conductive survey area.

Preliminary Study on the Paleoenvironment Reconstruction using a Bivalve from Sangmori Shell Mound (상모리패총에서 산출되는 이매패류 패각을 이용한 고환경 복원 예비연구)

  • Kim, Jeong-Suk;Woo, Kyung-Sik;Hong, Wan;Kang, Chang-Hwa
    • The Korean Journal of Quaternary Research
    • /
    • v.24 no.2
    • /
    • pp.35-48
    • /
    • 2010
  • The purpose of this study is to investigate paleoenvironmental conditions of the shallow sea around Jeju Island during the Late Holocene using geochemical contents of the bivalve (Glycymeris albolineata) collected from the Sangmori Shell Mound. The bivalve shell used shows the archaeological age of 2,300 yr BP. Stable carbon and oxygen isotope compositions show that growth rates decreased with aging. Coeval trends of both isotope compositions can be observed: heavier values during winters and lighter values summers except for their young and old growth stages. The seasonality of bivalve shell appear to reflect seasonal variations of paleotemperature as well as paleosalinity. Especially China Coastal Water with low salinity was transported into the southern Jeju Strait from Changjiang River during summer periods. Heavier carbon isotope values during winter indicate higher productivity, and this is supported by high density of phytoplanktons and higher chlorophyll contents during winter time. For accurate interpretation, monitoring of present-day conditions of shallow marine water as well as additional geochemical analysis of the same Recent bivalve may be necessary.

  • PDF

Understory Evapotranspiration Measured by Eddy-Covariance in Gwangneung Deciduous and Coniferous Forests (광릉 활엽수림과 침엽수림에서 에디공분산으로 관측한 하부 군락의 증발산)

  • Kang, Min-Seok;Kwon, Hyo-Jung;Lim, Jong-Hwan;Kim, Joon
    • Korean Journal of Agricultural and Forest Meteorology
    • /
    • v.11 no.4
    • /
    • pp.233-246
    • /
    • 2009
  • The partitioning of evapotranspiration (ET) into evaporation (E) and transpiration (T) is critical in understanding the water cycle and the couplings between the cycles of energy, water, and carbon. In forests, the total ET measured above the canopy consists of T from both overstory and understory vegetation, and E from soil and the intercepted precipitation. To quantify their relative contributions, we have measured ET from the floors of deciduous and coniferous forests in Gwangneung using eddy covariance technique from 1 June 2008 to 31 May 2009. Due to smaller eddies that contribute to turbulent transfer near the ground, we performed a spectrum analysis and found that the errors associated with sensor separation were <10%. The annual sum of the understory ET was 59 mm (16% of total ET) in the deciduous forest and 43 mm (~7%) in the coniferous forest. Overall, the understory ET was not negligible except during the summer season when the plant area index was near its maximum. In both forest canopies, the decoupling factor ($\Omega$) was about ~0.15, indicating that the understory ET was controlled mainly by vapor pressure deficit and soil moisture content. The differences in the understory ET between the two forest canopies were due to different environmental conditions within the canopies, particularly the contrasting air humidity and soil water content. The non-negligible understory ET in the Gwangneung forests suggests that the dual source or multi-level models are required for the interpretation and modeling of surface exchange of mass and energy in these forests.

Establishment of Korea National Counter-terrorism System and Development Plan (국가대테러체제의 구축 및 발전방안)

  • Park, Jun-Seok
    • Korean Security Journal
    • /
    • no.42
    • /
    • pp.229-249
    • /
    • 2015
  • As the post-cold war era and globalization go on, national security problems which were not traditional national security problems such as terrorism, crime, environmental disasters, economic crises, cyber-terrorism, diseases, and energy problems threat humanity and nations and demands changes. Also, with the change, the concept of "big government" has emerged as the role of nation expanded. The modern society sees every country change from small government to big government in order to realize the establishment of welfare state. A comprehensive interpretation of security is needed in order to comprehensive protection of citizens beyond outside invasion such as crime, new disaster, terrorism. In Korea, incidents such as Cheonan-Ham, Yeonpeyong-Do, foot-and-mouth disease, Ddos terrorism, pirates hostages, mad cow disease, AI are happening and the humanitarian support for North Korea and the summit of South and North Korea are at a standstill. Also, National emergency management system, comprehensive emergency management center, countrol tower, national security system, cooperation with citizens, establishment of legal and institutional system are needed. The importance of this research is on the reestablishment of new national security and emergency management system according to the comparison between the national security and counter-terrorism system of Korea and that of the United States which is a leading country in this field. Also, the establishment of national emergency management act is needed as a statute for effective function as currently various laws and administrative organizations are dispersed.

  • PDF

Hydrogeochemistry of shallow groundwaters in western coastal area of Korea : A study on seawater mixing in coastal aquifers (서해 연안지역 천부지하수의 수리지구화학 : 연안 대수층의 해수 혼입에 관한 연구)

  • 박세창;윤성택;채기탁;이상규
    • Journal of Soil and Groundwater Environment
    • /
    • v.7 no.1
    • /
    • pp.63-77
    • /
    • 2002
  • Salinization is an important environmental problem encountered in coastal aquifers. In order to evaluate the salinization problem in the western coastal area of Korea, we have performed a regional hydrochemical study on shallow well groundwaters (N=229) collected within 10 km away from the coastline. The concentrations of analyzed solutes are very wide in range, suggesting that the hydrochemistry is controlled by several processes such as water-rock interaction, seawater mixing, and anthropogenic contamination. Based on the graphical interpretation of cumulative frequency curves for some hydrochemical parameters (esp., $Cl^{-}$ and ${NO_3}^-$), the collected water samples were grouped into two major populations (1) a background population whose chemistry is predominantly affected by water-rock interaction, and (2) an anomalous population which records the potential influences by either seawater mixing or anthropogenic pollution. The threshold values obtained are 34.7 mg/l for $Cl^{-}$ and 37.2 mg/l for ${NO_3}^-$, Using these two constituents, groundwaters were further grouped into four water types as follows (the numbers in parenthesis indicate the percentage of each type water) : (1) type 1 waters (38%) that are relatively poor in $Cl^{-}$ and ${NO_3}^-$, which may represent their relatively little contamination due to seawater mixing and anthropogenic pollution; (2) type 2 waters (21%) which are enriched in $Cl^{-}$, Indicating the considerable influence by seawater mixing; (3) ${NO_3}^-$-rich, type 3 waters (11%) which record significant anthropogenic pollution; and (4) type 4 waters (30%) enriched in both $Cl^{-}$ and ${NO_3}^-$, reflecting the effects of both seawater mixing and anthropogenic contamination. The results of the water type classification correspond well with the grouping on a Piper's diagram. On a Br x $10^4$versus Cl molar ratio diagram, most of type 2 waters are also plotted along or near the seawater mixing line. The discriminant analysis of hydrochemical data also shows that the classification of waters into four types are so realistic to adequately reflect the major process(es) proposed for the hydrochemical evolution of each water type. As a tool for evaluating the degree of seawater mixing, we propose a parameter called 'Seawater Mixing Index (S.M.I.)’ which is based on the concentrations of Na, Mg, Cl, and $SO_4$. All the type 1 and 3 waters have the S.M.I. values smaller than one, while type 2 and type 4 waters mostly have the values greater than 1. In the western coastal area of Korea, more than 21% of shallow groundwaters appear to be more or less affected by salinization process.

Diagnostic Performance of Three Rapid Diagnostic Test Kits for Malaria Parasite Plasmodium falciparum

  • Park, Seo Hye;Jegal, Seung;Ahn, Seong Kyu;Jung, Haneul;Lee, Jinyoung;Na, Byoung-Kuk;Hong, Sung-Jong;Bahk, Young Yil;Kim, Tong-Soo
    • Parasites, Hosts and Diseases
    • /
    • v.58 no.2
    • /
    • pp.147-152
    • /
    • 2020
  • Malaria is a potent burden on public healthcare worldwide due to requiring rapid diagnosis and treatment. Nowadays, prompt diagnosis with rapid diagnostic tests (RDTs) has been widely accepted as an effective diagnostic technique in malaria-endemic countries, primarily due to their easy operation, fast output, and straightforward interpretation. The global availability and use of RDTs have gradually grown over recent decades as field-applicable diagnostic tests for the reliable confirmation of malaria infection and proper case management. This study was conducted to evaluate diagnostic performance of 3 commercially available malaria RDT kits : BIOCREDITTM Malaria Ag Pf(pLDH), Malaria Ag Pf(pLDH/pHRPII), and Malaria Ag Pf/Pv(pLDH/pLDH) (where pLDH and pHRPII stand for plasmodium lactate dehydrogenase and histidine-rich protein 2, respectively) for the specific detection of Plasmodium falciparum. A total of 1,129 blood samples including 95 blood samples, confirmed as vivax malaria infection by microscopic examinations and a nested-PCR method, were tested for falciparum malaria infection. The overall sensitivity and specificity of Malaria Ag Pf(pLDH/pHRPII), Malaria Ag Pf/Pv(pLDH/pLDH), and Pf(pLDH) for P. falciparum were 99.0% and 100%, 95.8% and 100%, and 100% and 100%, respectively. It is proposed that the 3 RDT kits perform reliable level of diagnostic accuracy of detection for P. falciparum parasites.

Remixed Sense of Place in Deoksugung(Kyungungung) - Since After the Daehan Empire Era' - (덕수궁(경운궁)의 혼재된 장소성에 관한 연구 - 대한제국시기 이후를 중심으로 -)

  • Han, So-Young;Zoh, Kyung-Jin
    • Journal of the Korean Institute of Traditional Landscape Architecture
    • /
    • v.28 no.2
    • /
    • pp.45-56
    • /
    • 2010
  • This study is dealing with Deoksugung around the founding of the Daehan Empire Era. It will looks closely into how locational contexts and sense of place have been changed according to the subject's view point and the interpretation of text community until Deoksugung is changed into citizen-oriented public place vested with the meaning of public park. In conclusion, Deoksugung was a place for suffering and sorrows, but also it was a place for ceaseless attempt to pursue of the recovery of past without loosing hope. As in the case of uprising war like Japanese invasion of Korea (Imjin Yeran) or Cheong Japan War, Deoksugung was an importantly historical place where autocrat temporarily stayed to stand up for the war and moreover, it was an imperial palace where the ambivalent sensibility between suffering and hope are intermingled in the very first Korean Empire in history. Unlike Kyeongbokgung and Changdeokgung, the current Deoksugung has changed its boundary from time to time since Japanese invasion of Korea up to the present. Deoksugung has evolved the present situation as endlessly changing its boundary by interacting with the neighbor of Kyungungung. The more complicated sense of place is coexisted in the features of the Deoksugung. Therefore, current hot topics concerning restoration project of Deoksugung is much more difficult than of other palaces. This issues should be carefully dealt with beyond the political interests.

Cultural Landscape Analysis of Changbai Mountain as Sacrifice Space (제사공간으로서 장백산의 문화경관적 해석)

  • Xu, Zhong-Hua;Sung, Jong-Sang
    • Journal of the Korean Institute of Traditional Landscape Architecture
    • /
    • v.34 no.4
    • /
    • pp.89-97
    • /
    • 2016
  • This study looked at the sacrifice space building in the Changbai Mountain area to a specific era in terms of the cultural landscape. The scared of Changbai Mountain how changes in history came despite the regime and national change, interpretation of the reason was the scared maintained. The results of this study are as follows. First, Replacement of the regime in the Republic of China in the Qing period, ethnic diversity, underwent a cultural acceptance. So Changbai Mountain nature of sacrifice, the divine subject has formed the changes. Second, the Qing Royal sacrifice space Wangji Temple(望祭殿) have formed a unique cultural space and the sacrifice of authoritative content with only space. The Republic of China period, a new folk beliefs were born between the defense in the face of the Han Chinese migration and settlement process. Build Sacrifice space of Rulai Temple(如來寺) and Shanshenlaobatou Temple(山神老把頭廟). Third, the spatial relationship between the priest and the Changbai Mountain area Wangji Temple(望祭殿) is the power of space as vertical space. Rulai Temple(如來寺), Shanshenlaobatou Temple(山神老把頭廟) is located in the Changbai Mountain and horizontal space was obedient to the space. Fourth, the sacrifice ritual Wangji Temple(望祭殿) of the Qing Dynasty is the only ritual sacrifice of satisfaction. It is cut off depending on the abolition of imperial power. Currently, public ritual sacrifice is commonplace rituals and sacrifices of the Qing Dynasty is only formally underway. In conclusion, as it has been maintained for the sanctity historically Changbai Mountain. Changbai Mountain sacrifice space was changing through the acceptance of the replacement of the regime and culture of ethnic offerings from a single culture of the Qing Dynasty. Currently, to form a sacrifice space and culture overlap through a mutually acceptable.

Spatial Analysis of the Confucian Cultural Landscapes at Jeongeuihyanggyo, Jeju Island (제주도 정의향교의 유교문화경관에 대한 공간분석)

  • Lee, HaengLyoul
    • Journal of the Korean Institute of Traditional Landscape Architecture
    • /
    • v.35 no.4
    • /
    • pp.29-42
    • /
    • 2017
  • Jeongeuihyanggyo(旌義鄕校) is a kind of traditional, Confucian cultural landscapes that is located in Jeju special self-governing province. Its historical background illustrates that the first erection was started at Goseong-li of Seongsan-eup(城山邑 古城里) at Taejong(太宗) of 16 years(1417) and it moved to the west gate of Hyunseong(縣城) at Heojong(憲宗) of 15 years,(1849) Joseon. The aim at this study is to reveal characters of these Confucian Spatial Composition and Order, which are valuable resources that can be created into the cultural contents. The results demonstrate the characters of the Confucian cultural landscape as followings; the changing process of new building and its relocation, the utilization of antique maps in location interpretation of Jeongeuihyanggyo, Confucian symbolic elements of it, the spatial compositions and layouts of its buildings, physical structures, main buildings and their characters, locational points of topographic profile, changes of axial line at Daeseongjeon(大成殿), the D/H ratio of its courts. This study can show that Jeongeuihyanggyo is a case for realizing the Confucian reformation to enhance Seongeup Hyun's education standard considering the locality of the site which is an isolated island like Jejudo(濟州島). The author can see that the example of Confucian space is applied to various layout techniques, both horizontally and vertically, in a limited space condition of being in the castle. Therefore, it is necessary to revive this point so that it can utilize unique Confucian cultural landscape possessed only by Jeongeuihyanggyo.