• Korean Journal of Environment and Ecology
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• v.27 no.2
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• pp.253-265
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• 2013

This study was correlation analysis between provision and management of street green and street environment through field survey about city official roads(93 routes, 629.2km) in Seoul. Green belt under the street trees were 17.5% of all routes. Composition of street green belt width of 1~ 2m was the most common(11.6%). Management status as a protected facilities were protect frame and prtect cover installed inerval(60.1%). Interval of pruning was 63.5%. Type of tree was mainly 47.9%. Road width was mainly more than 8-line(51.3%). Sidewalk width was mainly 3~6m(84.1%)in environment status of street. Landuse was mainly commercial and business(70.3%). Electronic wire complete was mainly compete with crown(33.6%). Use of sidewalk was mainly used(16.3%). ANOVA analysis was conducted between the Street green and environment of Street. Street green belt(more than with 3m) was analyzed to be effective in street green manufacture. Natural green area of city's outside and Industrial area were analyzed to be effective. Use of sidewalk was to be a management. Protection facilities are installed on the narrow sidewalk width lower intensity. There was a higher strength in narrow sidewalk width, road width and compete with crown. And type of tree was higher strength similarly. Pruning and type of tree showd a significant correlation. Thus, ensure sufficient sidewalk width and land use should be considered for street green was effective manufacture and management. Species selection and pruning management was needed by consider electronic wire management, type of tree and landscape.

• Journal of The Korean Astronomical Society
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• v.38 no.2
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• pp.283-287
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• 2005

The slow evolution of global magnetic fields and other dynamical processes in atmospheres of CP magnetic stars lead to the development of induced electric currents in all conductive atmospheric layers. The Lorentz force, which results from the interaction between a magnetic field and the induced currents, may modify the atmospheric structure and provide insight into the formation and evolution of stellar magnetic fields. This modification of the pressure-temperature structure influences the formation of absorption spectral features producing characteristic rotational variability of some spectral lines, especially the Balmer lines (Valyavin et al., 2004 and references therein). In order to study these theoretical predictions we began systematic spectroscopic survey of Balmer line variability in spectra of brightest CP magnetic stars. Here we present the first results of the program. A0p star $\Theta$ Aur revealed significant variability of the Balmer profiles during the star's rotation. Character of this variablity corresponds to that classified by Kroll (1989) as a result of an impact of significant Lorentz force. From the obtained data we estimate that amplitudes of the variation at H$\alpha$, H$\beta$, H$\gamma$ and H$\delta$ profiles reach up to $2.4\%$during full rotation cycle of the star. Using computation of our model atmospheres (Valyavin et al., 2004) we interpret these data within the framework of the simplest model of the evolution of global magnetic fields in chemically peculiar stars. Assuming that the field is represented by a dipole, we estimate the characteristic e.m.f. induced by the field decay electric current (and the Lorentz force as the result) on the order of $E {\~} 10^{-11}$ cgs units, which may indicate very fast (< < $10^{10}$ years) evolution rate of the field. This result strongly contradicts the theoretical point of view that global stellar magnetic fields of CP stars are fossil and their the characteristic decay time of about $10^{10}$ yr. Alternatively, we briefly discuss concurring effects (like the ambipolar diffusion) which may also lead to significant atmospheric currents producing the observable Lorentz force.

• Journal of Environmental Health Sciences
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• v.39 no.5
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• pp.408-417
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• 2013

Objectives: Phthalates are used as plasticizers in polyvinyl chloride (PVC) plastics. As phthalate plasticizers are not chemically bound to the PVC, they can leach, migrate or evaporate into indoor air and atmosphere, foodstuffs, other materials, etc. Therefore, humans are exposed through ingestion, inhalation, and dermal exposure over their entire lifetime, including during intrauterine development. In particular, university students have a great number of opportunities to contact products including phthalates during campus life (food packaging, body care products, cosmetic, lotions, aftershave, perfume etc.). The purpose of this study was to examine levels of phthalate exposure as undergraduate students begin to use pharmaceuticals and personal care products including phthalates. Methods: Phthalate metabolites, mono-ethyl phthalate (MEP), mono-n-butyl phthalate (MnBP), mono-isobutyl phthalate (MiBP), mono-2- ethylhexyl phthalate (MEHP), {(mono-(2-ethyl-5-hydroxyhexyl) phthalate (MEHHP}, and mono-(2-ethlyl-5-oxohexyl) phthalate (MEOHP} were examined. 80 urine samples collected from university students were analyzed using LC/MS/MS(API 4000, Applied Bioscience) with on-line enrichment and columnswitching techniques. This study was carried out at Y university located in Gyonggi Province from 2008 to 2011. Results: The detection limit of phthalate metabolites were 0.03 ng/mL for MEP, 0.11 ng/mL for MnBP, 0.08 ng/mL for MiBP, 0.93 ng/mL for MEHP, 0.19 ng/mL for MEOHP and 0.16ng/mL for MEHHP. MnBP showed the highest urinary levels (median: 31.6 ug/L, 24.8 ug/g creatinine (cr)). Concentrations were also high for MEHHP (median: 24.1 ug/L, 19.0 ug/g cr), followed by MEOHP (median: 22.8 ug/L, 17.9 ug/g cr). In individual cases, the maximum level reached up to 348 ug/L, and 291 ug/g cr, respectively. The urinary and creatinine adjusted levels of MEP were lower than those for DBP and DEHP metabolites, but were higher in 95th percentiles. As a result, the mean daily DEP intake value was 2.3 ${\mu}g/kg$ bw/day, 3.5 ${\mu}g/kg$ bw/day for DEHP and 4.9 ${\mu}g/kg$ bw/day for DBP. Conclusion: These students' phthalate exposure levels were below the international safe level set by the EU, but higher than the 2012 KFDA survey of the age group from 3 to 18.

• Journal of the Korean earth science society
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• v.31 no.6
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• pp.563-572
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• 2010

Both multi-channel temperature monitoring and geophysical electric survey were performed together for an embankment to assess the leakage zone. Temperature variation according to space and time on the inner parts of engineering constructions (e.g.: dam and slope) can be basic information for diagnosing their safety problem. In general, as constructions become superannuated, structural deformation (e.g.: cracks and defects) could be generated by various factors. Seepage or leakage of water through the cracks or defects in old dams will directly cause temperature anomaly. This study shows that the position of seepage or leakage in dam body can be detected by multi-channel temperature monitoring using thermal line sensor. For that matter, diverse temperature monitoring experiments for a leakage physical model were performed in the laboratory. In field application of an old earth fill dam, temperature variations for water depth and for inner parts of boreholes located at downstream slope were measured. Temperature monitoring results for a long time at the bottom of downstream slope of the dam showed the possibility that temperature monitoring can provide the synthetic information about flowing path and quantity of seepage of leakage in dam body. Geophysical data by electrical method are also added to help interpret data.

• Journal of Korean Society of Forest Science
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• v.102 no.1
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• pp.24-29
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• 2013

This study was carried out for preliminary feasibility review to investigate work efficiency of chestnut harvest using yield net and to find a way to reduce the cost for purchasing and managing yield net. To this end, we conducted a survey of 6 forest farm houses in Cheongyang, Gongju and Buyeo regions where yield nets are being used efficiently. Cost-benefit analysis based on Net Present Value and Benefit Cost Ratio was used to examine the investment profitability. While regions of Cheongyang A, Cheongyang B and Buyeo A are profitable in spite of no subsidy for purchasing yield net from the government, the regions of Gongju A, Gongju B and Buyeo B are not profitable without subsidy. When an 80% of subsidy for purchasing yield nets is provided, the forest farm houses in Cheongyang A, Cheongyang B, Buyeo A and Gongju B regions are found to be profitable while those in Gongju A and Buyeo B regions are still not profitable. We consider that the different results come from the differences in the planting method of chestnut, labor efficiency, labor skill and the orchard conditions such as slop. Finally, several efforts for government and cultivator are suggested to expand the use of yield net; planting chestnut in line, establishing installation and management methods, supporting the cost for purchasing yield net and studying detailed effects besides profitability issue.

• Journal of the Korean Data and Information Science Society
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• v.27 no.3
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• pp.791-801
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• 2016

The purpose of this study is to examine factors affecting the intent of re-employment of inactive registered nurses. This study presents a secondary analysis of data collected in 'Nurse Turnover On-line Survey' by Korean Nurses Association and Korea Institute for Health and Social Affairs in 2014. The analysis shows that 70.9% of inactive RNs has an intent to return to practice, and most of them preferred 'flexible working options' (47.8%) or 'fixed day shifts' (43.3%) as a work pattern. Main reasons for resigning from their last job have been found to be 'high work intensity' (18.8%) and 'difficulties of night shifts' (16.7%). Inactive married RNs who have working histories in a general hospital or a long-term care hospital or have preferences for traditional shift works showed a stronger intent to return to practice than their reference group. Our study shows that, for inactive RNs to return to practice, it is recommendable to adopt various non-traditional working patterns, to make a staffing distribution considering the labor intensity and to develop education programs designed to increase RNs' professional satisfaction.

• Korean Journal of Environment and Ecology
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• v.5 no.1
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• pp.79-90
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• 1991

This study was conducted to investigate seasonal avifauna and to suggest a proper way how to manage and protect wild birds in Chirisan National Park. The survey was carried over 3 main trail districts by line transect method to figure out influence factor of inhabitation of wild birds from February to November in 1991. The study results are as follows : The observed birds were belong to 6 orders 24 families 49 species and 981 individuals and Falco tinnunculus(Natural monument No. 323). These birds also classified into 24 species for residents, 12 species for summer visitor. 9 species for winter visitor, 4 species for passage migrant, respectively. The observed average frequeney of birds was 2.09e.a./ha, and main dominant species were Parus varius, Parus major, Emberiza elegans, Garrolus glandarius, Sitta europaea, Hypsipetes amaurotis, Parus palustris in order. Cheoneun-sa trail route showed relatively decreasing trend of wild birds during spring and fall season because of the highest trail use of visitors. Maximum frequency of species and individuals appeared at Hwaum-sa route in spring and at Piagol route in fall. respectively. Those regions well explained the advantageous inhabitation area of birds in both regions. The diversity index of birds in winter showed little difference of similarity index due to balanced use of trails. Seasonal low similarity index in those 3 main trail district indicate a dissimilarity of environmental factors. Trail use restriction as a provision of proper management and protection of wild birds have to be made at Hwaum-sa route where propagation of birds actively occurred in spring and at Piagol route where birds wintering were observed will contribute to enhance species diversity in the future.

• Korean Journal of Environment and Ecology
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• v.2 no.1
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• pp.19-36
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• 1988

To investigate edge vegetation structure and edge species in Chiak Mountain National Park, field survey was executed from July to September, 1988. Canonpy drip-line type, cantilevered type and advancing type of edge vegetation were observed on site. The relative importance values of major species in each crown layer were changed along distance from edge to forest interior differently by aspect and present tree layer vegetation. Especially light-oriented edge species as codominant species were observed in Pinus densiflora forest interior at south slope and moisture - oriented species as codominant species were observed with light-oriented species in north edge beside torrential stream. No. of species and individuals by crown layer, species diversities and dissimilarities were decreased according to the distance from edge to forest interior, and edge depth was estimated as 15-20m. Dominant species of edge in shrub and ground layer were different by altitude and topographic locations; valley, ridge, summit and edge species at summit were not observed at other area. Floristic similarities between edge vegetations at different environments were affected by altitude, aspect and topographic location. Frequency classes of edge species were different by aspect, altitude and topographic location. Weigela subscssilis showed high frequency class in all environment conditions and Quercus mongolica, Lindera obtusiloba, Symplocos chinensis for, pilosa, weigela subscssilis, Fraxinus rhynchophylla, Actinidia arguta, Rubus crategifolius. Pinus densiflora, Aralia elata etc, were observed as edge species at all environmental conditions, respectively.

• Proceedings of the KSR Conference
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• 2010.06a
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• pp.1982-1990
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• 2010

Excepting tunnel of dorimstream - ccachimountain station section, the subway line No.2th section was build using ASSM and NATM methods because of soil pressure and land condition. The way of dealing underground water was selected without sufficient preconsideration of geographical features, ground condition, influence of lowing underground water, and long-term cost of running maintenance so that the form of undrained tunnel was build having decreased construction characteristics and technically improper elements. The form of partial drainage is very difficult to manage structures of tunnel, because water leakage, water pressure causing cracks of lining concretes and scaling are constantly happened. so partial drainage suggest that setting reinforced Anchor Bolt to prevent buoyancy and should increase center drainage way up to height of railroad. Partial drainage suggest that holey pipe(${\phi}$350mm) manhole, drainage checking pipe manhole are should be regularly dredged, when changing roadbed(gravel${\rightarrow}$concrete) drainage checking pipe manhole should be build and setting a limitation of entering underground water's quantities. Beside drainage degree in changed section of structures causing instability of structures is continuous degree. so if efficient drainage way and the patterns of flaws, problems are considered in survey, it will be expected to have a advantage condition in maintenance part.

• Geophysics and Geophysical Exploration
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• v.7 no.2
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• pp.136-147
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• 2004

In this study, the characteristics of magnetotelluric (MT) responses due to a three-dimensional (3-D) body are analyzed with 3-D numerical modeling. The first model for the analysis consists of a single isolated conductive body embedded in a resistive homogeneous half-space. The second model has an additional conductive overburden while the other conditions remain the same as the first one. The analysis of apparent resistivities shows well that the 3-D effects are dominant over some frequency range for the first model. Two mechanisms, current channeling and induction, for secondary electric fields due to the conductive body are analyzed at various frequencies: at high frequencies induction is more dominant than channeling, while at low frequencies channeling is more dominant than induction. Tippers have a strong relation to the position of anomalous body and the real and imaginary parts of induction vector also indicate the position of anomalous body. off-line conductive anomaly sometimes causes severe problem in 2-D interpretation. In such case, induction vector analysis can give information on the existence and location of the anomalous body. Each parameter of the second model shows similar responses as those of the first model. The only difference is that the magnitude of all parameters is decreased and that the domain showing the 3-D effects becomes narrower. As shown in this study, the analysis of 3-D effects provides a useful and effective means to understand the 3-D subsurface structure and to interpret MT survey data.