• Journal of Environmental Health Sciences
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• v.34 no.1
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• pp.42-48
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• 2008

The objectives of this study were to measure ambient TGM concentrations in Seoul Korea, to determine the temporal variation of TGM, and to analyze the relationships among TGM, meteorological data and PM2.5 measured at the same time. Ambient TGM and PM2.5 concentrations were measured at the roof of the Graduate School of Public Health building in Seoul, Korea for the period of January to October 2004. Average TGM concentration was $3.43{\pm}1.17ng/m^3$. The average TGM was at a low concentration similar to those of background sites in other countries. The temporal variations and meteorological phenomena of TGM were not statistically significant. There was a positive link between TGM and PM2.5. It didn't indicate that reduction of $Hg^{2+}$ to Hg0 had occurred in liquid water contained in smog as in a previous study, but it shows that PM2.5 and TGM could be emitted from the same sources such as power plants and combustion engines. Also, the strong correlation between TGM and $SO_2$ concentrations indicated that the source of TGM was from fossil fuel combustions including coal combustion. Specifically, $SO_2\;and\;SO_4{^2-}$ concentrations correlated to TGM concentrations could be linked to TGM emitted from local and regional sources as well.

• Korean Journal of Food Science and Technology
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• v.37 no.3
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• pp.334-338
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• 2005

Method was developed to efficiently analyze semicarbazide (SEM) in foods. Although SEM is produced by thermal decomposition of blowing agent azodicarbonamide, it is too small to be activated by ultraviolet light or fluorescence. When 2-nitrobenzaldehyde semicarbazone, derivatization of SEM, was analyzed by HPLC with triple column system, coefficient correlation over 0.9997 and detection limit of 0.48 ng/g were observed. SEM level in commercial bottle cap gasket was 812.20-5771.30ng/g. Recoveries for SEM in food and PVC gasket were 83.45-97.33% and 92.12-98.71%, respectively. SEM level in plastic seals of press twist-off metal lids was ND-5771.330ng/g.

• Journal of environmental and Sanitary engineering
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• v.20 no.1 s.55
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• pp.1-11
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• 2005

This research was performed to investigate the generation and physico-chemical characteristics of municipal solid wastes in the east coast of gangwon. The results were as follows: i) The generation rate of G city and Y gun were 0.187-0.384 $\cal{kg/cap/d}$ and 0.136-0.259 $\cal{kg/cap/d}$. Apparent density of G city and Y gun were 137.9-191.9 g/L and 157.3-238.3 g/L, respectively. ii) The wastes consisted of $76.1-97.5\%$ of combustibles and $2.5-23.9\%$ of incombustibles in G city. And the wastes consisted of $73.7-98.6\%$ of combustibles and $1.4-26.3\%$ of incombustibles in Y gun. Most of municipal solid wastes are composed of food, paper, and vinyl-plastics waste. Water content of commercial area, agricultural resident, detached resident, apartment area, school zone were 42.5-45.9, 37.6-43.4, 32.4-38.4, 29.3-32.3, $6.8-26.9\%$, respectively. iii) The low heating value of G city and Y gun were 1,125.5-2,540.7 $\cal{kcal/kg}$, 1,104.4-2,062.3 $\cal{kcal/kg}$, and school and apartment area were higher than commercial area.

• The Journal of Korean Society for Radiation Therapy
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• v.11 no.1
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• pp.6-10
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• 1999

The field size can be beam output, therefore MonitorUnit can be varied due to field size dependence The purpose of this study is to evaluate and compare the dose variation according to exchange of collimator The measurements were perfomed with Wellhofer dosimetry system(water phantom. ion chamber. electrometer. system controller. build up cap. etc)and two types of linear accerlerator (Mevatron KD, MevatronMX) Scatter can be affected to field size dependence and scatter correction is separated into collimator and phantom components, scatter components can affect by exchanging of collimator Measurements of collimator scatter factor(Sc) was done in air with build up cap. 1)Square field (5cm2 to 40cm2) was measured 2)and then keeping the upper jaw constant at loom and varing lower jaw from 5cm to 40cm, 3)keeping the lower jaw constant at 10cm and varing upper jaw from 5cm to 40cm Measurements of total scatter factor(Scp) was done in water at Dmax as the procedure of collimator scatter factor measurements in water Dmax The total scatter factors were obtained to the following equation(Sp=Scp/Sc) The measured data is normalized to the data of reference field size($10{\times}10$), rectangular field is inverted to equivalent field to compare three field size data As the collimator setting is varied, the output was changed In conclusion, the error was obtained small but it must be eliminated if we intend to reach the common stated goal of $5\%$ overall uncertainty in dose determination

• Interaction and multiscale mechanics
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• v.2 no.4
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• pp.397-411
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• 2009

The effect of soil-structure interaction on a simple single storeyed and two bay space frame resting on a pile group embedded in the cohesive soil (clay) with flexible cap is examined in this paper. For this purpose, a more rational approach is resorted to using the three dimensional finite element analysis with realistic assumptions. The members of the superstructure and substructure are descretized using 20 node isoparametric continuum elements while the interface between the soil and pile is modeled using 16 node isoparametric interface elements. Owing to viability in terms of computational resources and memory requirement, the approach of uncoupled analysis is generally preferred to coupled analysis of the system. However, an interactive analysis of the system is presented in this paper where the building frame and pile foundation are considered as a single compatible unit. This study is focused on the interaction between the pile cap and underlying soil. In the parametric study conducted using the coupled analysis, the effect of pile spacing in a pile group and configuration of the pile group is evaluated on the response of superstructure. The responses of the superstructure considered include the displacement at top of the frame and moments in the superstructure columns. The effect of soil-structure interaction is found to be quite significant for the type of foundation used in the study. The percentage variation in the values of displacement obtained using the coupled and uncoupled analysis is found in the range of 4-17 and that for the moment in the range of 3-10. A reasonable agreement is observed in the results obtained using either approach.

• Journal of Korean Society on Water Environment
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• v.25 no.4
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• pp.481-493
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• 2009

This study was conducted to performance appraisal of Total Maximum Daily Loads (TMDLs), especially in terms of performance on development & reduction plan and water quality status of unit watershed. Because load allocations for pollution sources were predicted redundantly by uncertainty of prediction, TMDLs master plan has been frequently changed to acquire load allocation for local development. Therefore, It need to be developed more resonable prediction techniques of water pollution sources to preventing the frequent change. It is suggested that the reduction amount have to be distributed properly during the planning period. In other words, it has not to be concentrated on the specific year (especially final year of the planning period). The reason why, if the reduction amount concentrate on the final year of the planning period, allotment loading amount could not be achieved in some cases (e.g., insufficiency of budget, extension of construction duration). If the development plan was developed including uncertain developments, it is necessary to be developed reduction plan considered with them. However, some of the plans in the reduction plan could not be accomplished in some case. Because, it is not considered financial abilities of local governments. Consequently, development plan must be accomplished to avoid uncertain developments, and to consider financial assistance to support the implementation of effective plan. Water quality has been improved in many unit watersheds due to the TMDLs, especially in geum river and yeongsang/seomjin river.

• Journal of the Korean Geosynthetics Society
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• v.9 no.3
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• pp.9-18
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• 2010

A series of model tests were performed to investigate the load transfer by soil arching in geosynthetic-reinforced and pile-supported(GRPS) embankment systems. In the model tests, model piles with isolated cap were inserted in the model container and geosynthetics was laid on the pile caps below sand fills. The settlement of soft ground was simulated by rubber form. The loads acting on pile caps and the tensile strain of geosynthetics were monitored by data logging system. At the given interval ratio of pile caps, the efficiency in GRPS embankment systems increased with increasing the height of embankment fills, then gradually converged at constant value. Also, at the given height of embankment fills, the efficiency decreased with increasing the pile spacing. The embankment loads transferred on pile cap by soil arching increased when the geosynthetics installed with piles. This illustrated that reinforcing with the geosynthetics have a good effect to restraint the movement of surrounding soft grounds. The load transfer in GRPS embankment systems was affected by the interval ratio, height of fills, properties of grounds and tensile stiffness and so on.

• Korean System Dynamics Review
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• v.14 no.4
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• pp.113-141
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• 2013

The main purpose of this research is to introduce PsyCap(Positive Psychological Capital) and new leadership helping ordinary people to create positive thinking and leading to social integration in South Korea. Additionally, by looking at conventional leadership theories and by applying the PsyCap to leadership based on causal loop analysis, this study is to seek new approach which political leader is able to communicate with the people and can help the people to build positive mine. Throughout this study, there are several important implications how political leader can lead to social integration and stable political development in South Korea. In particular, when political leader encourage the people to have confidence to take on and put in the necessary effort to succeed at challenging tasks, when political leader make the people a positive attribution (optimism) about succeeding now and in the future, when political leader help the people to persevere toward goals and redirection paths to goals (hope) in order to succeed, and when political leader make the people beset by problems and adversity environment to overcome these concerns, it can be expected political leader to build social integration and the people to create positive thinking which has been emphasized by political leader in South Korea. Finally, 21st century has required new political leadership that the people are able to make positive psychological capital composed by optimism, hope, confidence, and resilience.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.24 no.1
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• pp.36-46
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• 2013

This paper proposes the design of broadband spiral antenna for a potable non-linear junction detector (NLJD) system. To realize the broadband antenna design, it was considered optimization of the number of spiral turns by iteration calculation. Ground plane with the Archimedean spiral slit to keep the same current distribution between radiating plane and ground is considered for circular polarization design. In order to realize high directivity and high gain of the proposed antenna, the cavity wall and the metal cap which is located on back of ground plane were also considered in design. Measurement results of return loss were agreed well with VSWR 2:1 at interested frequency band among 2.4 to 2.44 GHz, 4.84 to 4.92 GHz and 7.28 to 7.36 GHz. Measured axial ratio was observed 3 dB below and showed reasonable agreement with simulation results. Characteristics of the RHCP(Right Hand Circular Polarization) with the measured gain of 6.8 dBi above at interested frequency band were also observed.

• Korean Journal of Construction Engineering and Management
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• v.7 no.5
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• pp.94-104
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• 2006

The changed Korean government law associated with the public apartment housing supply, so called the $^{\circ}{\AE}$Apartment Sales Price $Cap^{\circ}{\phi}$, requires new system for estimating construction cost in order to set appropriate price. A model apartment project was carefully designed and its construction cost were analyzed in many different ways. Based on the analyses outcomes, 1,028,000 Won/m2 (excluding cost for underground parking lot) is the most appropriate Price Cap for a smaller than $85{\beta}{\geq}$ apartment unit. Further, it was revealed that the price have to be adjusted reflecting such factors as underground size; structural system; external complex quality; and consumer preferences. Findings from this study will enable the Korean government to realize faster and better application of the related laws. The methodology for obtaining appropriate apartment construction cost will also benefit for future researchers.