• Journal of Environmental Impact Assessment
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• v.12 no.1
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• pp.1-8
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• 2003

The Master Plan of Natural Environment Conservation in Korea by Ministry of Environment has been carried out since 1986. The 2nd 10-year survey started in 1997, and there are three major parts in the Master Plan : First, the basic natural environment survey, second, sites in special features of ecological characteristics such as uninhabitable islands, wetlands, etc, and third, biological species featuring status of habitat, and population dynamics. However the information in the Master Plan is very fragmented and collected data are not so abundant due to insufficient man-power and unsynchronized survey time/season. In this regard this paper examined the similar National Biological Survey in USA and compared the differences with the Master Plan in Korea. The Master Plan in Korea should separate the management zone based on hydrological characteristics, and in each zone we should set a management goal in the long term basis. Secondly the species list is not so meaningful that we must concentrate more on research activities. In each taxonomical group we set up hypotheses and research goals. Thirdly local residents and communities should be involved in research so that enhanced biological diversity should benefit people in areas. Lastly legislation and laws should be reexamined and rectified to provide information to the managers that deals with natural resources, expecially when conflicting with economic matters.

• The Korean Journal of Quaternary Research
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• v.13 no.1
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• pp.1-23
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• 1999

A palynological investigation of the Annyeong-ri, Hwasung-gun Gyeonggi-do, in where Yung-Nung and Gun-Nung are located, was carried out for the first time. From the pollen analysis, two pollen zones are established: Pollen Zone I : Ainus-Quercus-Pinus and Pollen Zone Ⅱ : Pinus. Pollen Zone I is characterized by Mixed coniferous and deciduous broadleaved vegetation during about 3,500 yr. B.P.-2,000 yr. B.P., while after 2,000 yr. B.P. Pollen Zone Ⅱ appears to be Coniferous vegetation and Evergreen broadleaved vegetation. The former reflects there was a lowland fluvio-lacustrine environment before fully lacustrine one which represents the latter. Pollen analysis indicates the vegetation before 2,000 yr. B.P. was controled by environmental factor such as climate conditions, whereas after that time vegetation was strongly effected by human's impact. It is concluded that pollen analysis is useful to find out the relationship between vegetation history and man's interference. In addition freshwater algae play to tell the lake environments.

• Archives of Plastic Surgery
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• v.42 no.5
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• pp.614-618
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• 2015

Background Hand strength deficit following digital replantation is usually attributed to the mechanical deficiency of the replanted digit. Zone 1 replantation, however, should not be associated with any mechanical deficit, as the joint and tendon are intact. We evaluate shortterm motor functions in patients who have undergone single-digit zone 1 replantation. Methods A single-institution retrospective review was performed for all patients who underwent zone 1 replantation. Hand and pinch strengths were evaluated using standard dynamometers. Each set of measurements was pooled according to follow-up periods (within 1 month, 1 to 2 months, 2 to 3 months, and after 3 months). The uninjured hand was used as reference for measurements. Results The review identified 53 patients who had undergone zone 1 replantation and presented for follow-up visits. Compared to the uninjured hand, dynamometer measurements revealed significantly less strength for the hand with replanted digit at one month. The relative mean grip, pulp, and key pinch strength were 31%, 46%, and 48% of the uninjured hand. These three strength measurements gradually increased, with relative strength measurements of 59%, 70%, and 78% for 4-month follow up. Conclusions Despite the lack of joint or tendon injury, strength of the injured hand was significantly lower than that of the uninjured hand during the 4 months following replantation. Improved rehabilitation strategies are needed to diminish the short-term negative impact that an isolated zone 1 replantation has on the overall hand strength.

• Tunnel and Underground Space
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• v.18 no.5
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• pp.366-374
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• 2008

Tunnelling under water table induces many geotechnical problems because of groundwater. In subsea tunneling, reduction of face stability can induce flooding in the vicinity of a fracture zone characterized by high permeability and high water pressure. In this study, the effects of high water pressure on the stability of a tunnel face in a limited zone with high permeability(hazardous zone) are analyzed. On the basis of the 'advance core' concept, the seepage force acting on a hypothetical cylinder ahead of a tunnel face is modeled. This study focuses on the hydraulic behavior of the ground ahead of the tunnel face by three-dimensional steady-state seepage analyses. The impact of the hazardous zone on the seepage force and stability of the tunnel face are simulated and analyzed. In light of the analysis results, it is estimated that the distance from the tunnel face to the exterior boundary limit, which the seepage force significantly affects the stability of the tunnel face, of a hypothetical cylinder is approximately 5 times the tunnel radii. Despite the restrictive assumptions of this study, the results are highly indicative regarding the risks of hazardous zones.

• Journal of Korean Society on Water Environment
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• v.24 no.5
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• pp.556-562
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• 2008

We divided the downstream of South-Han River into three water zones, such as river zone, transition zone and lacustrine zone depending on the flow rate, and elucidated the major effect factors on the growth of phytoplankton and the sources of organic matters in each water zone. The difference of chlorophyll-a concentration which represents the standing crop of phytoplankton was statistically significant among the water zones. From the results of bivariate correlation analysis between chlorophyll-a concentration and water quality parameters in each water zone, the outflow of Chungju dam and hydraulic retention time of Lake Paldang which are directly related with the flow rate seemed to have obvious impact on phytoplankton growth in the downstream of South-Han River. The concentration of nutrients such as phosphorus and nitrogen exceeded the criterion of eutrophication and did not showed significant relationship with chlorophyll-a concentration. There were strong correlations between $BOD_5$ and chlorophyll-a concentrations in transition and lacustrine zone showing autochthonous production of phytoplankton was dominant source of organic matters in these zones especially in dry seasons. The results of this study show that the control of abundance of phytoplankton is the key target for reduction of the organic pollution in the downstream of South-Han River.

• Journal of Korean Tunnelling and Underground Space Association
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• v.8 no.2
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• pp.87-100
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• 2006

A kinematically constrained microplane constitutive model is developed for intact granite. The model is verified by fitting the experimented data of Westerly granite and Bonnet granite. Using the model with the standard finite element method, the behavior of the intact granite subjected blasting impact is studied. What is studied includes the attenuation of the blasting waves, the size of the fractured zone and the effect of the charge condition to avoid overbreak of the rock mass. The model developed captures the energy loss due to the inelastic behavior and the microcracking of granite during blasting very well. The attenuation of the blasting waves calculated based on the model is much more than that based on the linear-elastic constitutive law. The size of damaged (or fractured) zone is calculated directly from the principal strain as blasting impact is spreading, not like in the case with the linear elasticity model.

• Korean Journal of Environment and Ecology
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• v.6 no.1
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• pp.44-54
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• 1992

A survey of subalpine zone (altitude is 1, 440-1, 700m) in Mt. Halla, was conducted using 37 sampling plots of l00$m^2$ size. The classification by TWINSPAN and RA. DCA ordination were applied to the study area in order to classify them based on woody plants and environmental variables. And to investigate vegetation deterioration by livestock's and user's impact on subalpine zone, seventeen plots were set up. By TWINSPAN techniques, the plant community were divided into five groups by the altitude. The dividing groups are Abies koreana-Taxus cuspidata community, Rhododendron yedoense var. poukhanense-Rh. mucronulatum var. ciliatum-Sasa quelpaertensis community, Ilex crenata- Elaeagnus umbellata-S. quelpaertensis community, Rh. yedoense var. poukhallense-Juniperus chinensis var. sargentii-Rh. mucronulatum var. ciliatum community and Empetrum nigrum var. japonicum-J. chinensis var. sargentii community. The species divirsity of plant community were decreased severely by livestock's and user's impact.

• Korean Journal of Metals and Materials
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• v.47 no.3
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• pp.139-146
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• 2009

The heat-affected zone (HAZ) of SA508 Gr.4N Ni-Mo-Cr low alloy steel, which has higher Ni and Cr contents than SA508 Gr.3 Mn-Mo-Ni low alloy steel, was investigated on the microstructure and mechanical properties. The HAZ was categorized into seven characteristic zones (CGCG, FGCG, ICCG, SCCG, FGFG, ICIC and SCSC-HAZ) according to the peak temperature from the thermal cycle experienced during multi-pass welding. Post Weld Heat Treatment (PWHT) was conducted in the temperature range of $550{\sim}610^{\circ}C$ for 30 hours to evaluate the effect of PWHT conditions on the microstructure and mechanical properties. Before PWHT, CGHAZ and FGFGHAZ showed high yield strength (YS) ranging from 1000 to 1250 MPa, while YS of SCSCHAZ decreased from 607 MPa (observed for base metal) to 501 MPa. The Charpy impact energies of sub-HAZs fell below 100J at $-29^{\circ}C$, except in the SCSCHAZ. By applying PWHT to sub-HAZ specimens, YS decreased as the PWHT temperature increased. In the case of CGHAZs and FGFGHAZ heat-treated at $610^{\circ}C$, YS dropped drastically to the range of 654~686 MPa. From the Charpy impact test, the upper-shelf energy (USE) increased to approximately 250J and Index temperature ($T_{68J}$) decreased below $-50^{\circ}C$. Specifically, in FGFG, ICIC and SCSC-HAZ, $T_{68J}$ was below -110, which was lower than the case of base metal.

• Journal of the Korean Society for Heat Treatment
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• v.35 no.4
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• pp.185-192
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• 2022

Variations in the microstructure and mechanical properties of API X70 steel processed by piping, electrical resistance welding (ERW), and post seam annealing (PSA) are investigated in this study. In the welding zone, some elongated pearlites are formed and grains coarsening occurs due to extra heat caused by the ERW and PSA processes. After the piping, the base metal shows continuous yielding behavior and a decrease in yield and impact strengths because mobile dislocation and back stress are introduced during the piping process. On the other hand, the ERW and PSA processes additionally decreased the impact strength of welding zone at room and low temperatures because some elongated pearlites easily act as crack initiation site and coarse ferrite grains facilitate crack propagation. As a result, the fracture surface of the welding zone specimen tested at low temperature revealed mostly cleavage fracture unlike the base metal specimen.

• Journal of Environmental Impact Assessment
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• v.24 no.1
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• pp.99-109
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• 2015

The Ecosystem and Nature Map (ENM) is basic map for current status of natural resources. The map has been offered information to ecological conservation and restoration, as well as to land use planning and policy making. The map composed of 794 sheets in 1:25,000 scale classifies total areas into three grade zones (1st, 2nd and 3rd grade zones) and separately managed zone. In 2005, the first draft Ecosystem and Nature Map was prepared by the second National Ecosystem Survey. It was opened for the people to search and appeal. So 1,419 cases of public appeals on the first draft Ecosystem and Nature Map were submitted in 2005. After partial revision, the first Ecosystem and Nature Map was announced in 2007. The second draft Ecosystem and Nature Map was prepared by the third National Ecosystem Survey and opened to public in 2012. As a result, 1,263 cases of public appeals were submitted in 2012. Since the first announcement of the Ecosystem and Nature Map in April 2007, 182 cases of public appeals on the Map were submitted until December 2013. Among them, 159 cases were announced with revision. According to the first Ecosystem and Nature Map announced in 2007, graded areas covered 7.5% in the 1st grade zone, 39.2% in the 2nd grade zone and 44.7% in the 3rd grade zone of the national land area, respectively. In the second draft Ecosystem and Nature Map in 2012, areas of the 1st grade zone and the 2nd grade zone were 9.2% increased 1.7 percentage points and 45.5% increased 6.3 percentage points, and areas of the 3rd grade zone were 36.6% decreased 8.1 percentage points. Among areas of the 1st grade zone, Gangwondo occupies 54.3% in 2007 and 47.6% in 2012. Gangwondo consists of the highest percentage of the 1st grade zone and the smallest of the 3rd grade zone. Seoul has the highest percentage of the 3rd grade zone. There were the highest increase of the 1st grade zone in Gyeongsangbukdo and the highest decrease in Jeollabukdo and Seoul. Vegetation is the most important evaluation factor to determine the grade of the Ecosystem and Nature Map.