• Korean Journal of Agricultural and Forest Meteorology
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• v.15 no.4
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• pp.312-319
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• 2013

Our understanding of the sensitivities of crop responses to changes in carbon dioxide, temperature, and water is limited, which makes it difficult to fully utilize crop models in assessing the impact of climate change on future agricultural production. Genetic coefficients of CERES-Barley model for major domestic cultivars in South Korea (Olbori at Suwon, Albori at Milyang, Saessalbori at Iksan, and Samdobori at Jinju) were estimated from the observed data for daily weather and field trials for more than 10 years by using GenCalc in DSSAT. Data from 1997-2002 annual crop status report (Rural Development Administration, RDA) were used to validate the crop coefficients. The sitecalibrated CERES-Barley model was used to perform crop growth simulation with the 99 treatments of step change combinations in temperature, precipitation and carbon dioxide concentration with respect to the baseline climate (1981-2010) at four sites. The upper boundary corresponds to the 2071-2100 climate outlook from the RCP 8.5 scenario. The response surface of grain yield showed a distinct pattern of model behavior under the combined change in environmental variables. The simulated grain yield was most sensitive to $CO_2$ concentration, least sensitive to precipitation, and showing a variable response to temperature depending on cultivar. The emulated impacts of response surfaces are expected to facilitate assessment of projected climate impacts on a given cultivar in South Korea.

• International Journal of Highway Engineering
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• v.10 no.4
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• pp.9-18
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• 2008

Curling is caused by the difference in the temperature and humidity by the depth of the slab in Jointed Plain Concrete Pavement. Slab curvature shape and size change due to curling exert a profound influence on the internal stress and roughness of the pavement, affecting structural and functional performance of the pavement. Direct measurement of the slab curvature entails many problems. Many measuring instruments have to be installed at the early-stage of the pavement construction, and the behavior of the slab curvature needs to be measured accurately from the early-stage. Moreover, the cost and technical difficulty are very formidable to measure the slab curvature. This study develops a measurement method for slab curvature in jointed concrete pavement at any given time by applying Power Spectrum Density Analysis and Inverse Fast Fourier Transformation to the profile data, that can be easily obtained at the construction field site. The effectiveness of this developed method is verified by measuring the profile data of the test road of jointed concrete pavement at an inland central expressway by the hour and by examining the result of extracting the slab curvature shape from this profile data. Additionally, the profile data of CRCP(Continuously Reinforced Concrete Pavement) sections on the same expressway were obtained and analyzed at the same time. The validity of the method developed for the slab curvature shape extraction is verified by comparing the result from the analysis of the profile data of CRCP sections with that from the analysis of the prof1Ie data of jointed concrete pavement sections.

• Korean Security Journal
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• no.18
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• pp.143-167
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• 2009

As of entering the 21st century, a trend in the field of a private security industry among the advanced countries have been increased a qualification system and train session to meet the needs of professionalism. Intensifying the professionalism in Korea, education and train system has been initiated to change but the oligopoly market already formulated due to impractical selection standard and management of education system. Issuing certification and offering basic training through a designated institution for the purpose of improving quality of the private security industry worker, its practical effectiveness were lower than expectation. Rather certification-holder or security agency, institution or truster's rent-seeking behavior have been increased by occupational licensing system. The founded results, which were associated to problems in selecting and educating to the private security guard, in this study were that any verification has been initiated towards dual-system in official approval and structural problems in education system, and non-existence of verification for professionalism and management capability to security agency owner and its upper managerial level. Current a dual system in an officially authorized verification system and completion of security guard credential requested change to an unified official qualification verification system to solve those problems. Ranges of an applicant to the unified official qualification verification system should be extend to the whole population in the private security industry. Moreover, minimization of the dead-weigh loss, which is caused by oligopoly phenomenon while using its market-dominant status, increasement number of designated institution, which allows self-regulating competition, and endowment of autonomy, which is in selecting education and agency, were requested to solve the problems in selecting and educating to the private security guard. In order to minimize stated problems while maintaining objectiveness, a new manage and supervise institution, which is called a 'private security industry committee', should be establish. The private security industry committee is a formation of governance network which are participated from professional group to civil organization.

• Korean Journal of Medicinal Crop Science
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• v.24 no.5
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• pp.341-350
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• 2016

Background: Prenatal exposure to infectious and/or inflammatory insults can increase the risk of developing neuropsychiatric disorder such as bipolar disorder, autism, and schizophrenia later in life. We investigated whether Valeriana fauriei (VF) treatment alleviates prepulse inhibition (PPI) deficits and social interaction impairment induced by maternal immune activation (MIA). Methods and Results: Pregnant mice were exposed to polyriboinosinic-polyribocytidilic acid (5 mg/kg, viral infection mimic) on gestational day 9. The adolescent offspring received daily oral treatment with VF (100 mg/kg) and injections of clozapine (5 mg/kg) for 30 days starting on the postnatal day 35. The effects of VF extract treatment on behavioral activity impairment and protein expression were investigated using the PPI analysis, forced swim test (FST), open field test (OFT), social interaction test (SIT), and immunohistochemistry. The MIA-induced offspring showed deficits in the PPI, FST, OFT, and SIT compared to their non MIA-induced counterparts. Treatment with the VF extract significantly recovered the sensorimotor gating deficits and partially recovered the aggressive behavior observed in the SIT. The VF extract also reversed the downregulation of protein expression induced by MIA in the medial prefrontal cortex. Conclusions: Our results provide initial evidence of the fact that the VF extract could reverse MIA-induced behavioral impairment and prevent neurodevelopmental disorders such as schizophrenia.

• Journal of the Mineralogical Society of Korea
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• v.16 no.4
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• pp.295-305
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• 2003

This study aims to provide the physicochemical properties of three kinds of organo­smectites which can be diversely used in industries. Some properties of them were compared with Na­smectite. Three kinds of organo­smectites such as Hexadecyltrimethylammonium(HDTMA), Benzyldimethyltetradecylammonium(BDTDA), and Cetylpyridinium(CP) exchanged smectites were manufactured for this study. Three types of organo­smectites showed the alkaline character(pH 9), very low swelling property and viscosity, and a fast flocculation behavior because of strong hydrophobic property in contrast to hydrophilic Na­smectite. Three organo­smectites showed the strong interlayer expansion with basal spacing from $19\AA$ to $23\AA$ compared with the Na­smectite of about 12 $\AA$. Organic cations such as HDTMA, BDTDA, and CP exchanged into smectite were completely decomposed in the temperature range from $250^{\circ}C$ to $400^{\circ}C$. Generally, three organo­smectites showed the similar mineralogical, physicochemical and thermal properties. But their properties are quite different from Na­smectite. Considering economically, CP exchanged smectite would be used for the diverse utilization field in the future time.

• Journal of Powder Materials
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• v.24 no.4
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• pp.302-307
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• 2017

In this study, Fe-Cu-C alloy is sintered by spark plasma sintering (SPS). The sintering conditions are 60 MPa pressure with heating rates of 30, 60 and $9^{\circ}C/min$ to determine the influence of heating rate on the mechanical and microstructure properties of the sintered alloys. The microstructure and mechanical properties of the sintered Fe-Cu-C alloy is investigated by X-ray diffraction (XRD) and field-emission scanning electron microscopy (FE-SEM). The temperature of shrinkage displacement is changed at $450^{\circ}C$ with heating rates 30, 60, and $90^{\circ}C/min$. The temperature of the shrinkage displacement is finished at $650^{\circ}C$ when heating rate $30^{\circ}C/min$, at $700^{\circ}C$ when heating rate $60^{\circ}C/min$ and at $800^{\circ}C$ when heating rate $90^{\circ}C/min$. For the sintered alloy at heating rates of 30, 60, and $90^{\circ}C/min$, the apparent porosity is calculated to be 3.7%, 5.2%, and 7.7%, respectively. The hardness of the sintered alloys is investigated using Rockwell hardness measurements. The objective of this study is to investigate the densification behavior, porosity, and mechanical properties of the sintered Fe-Cu-C alloys depending on the heating rate.

• Journal of Korean society of Dental Hygiene
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• v.10 no.6
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• pp.991-1000
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• 2010

Objectives : The purpose of this study was to analyze 356 papers included in the Journal of the Korean Society of Dental Hygiene between 2000 when the initial number was issued and April, 2010. The papers involved articles, treatises, theses and dissertations. Methods : According to existing literature related to paper analysis, all the journals were analyzed by year to find out the subjects of the studies, places for data gathering, the presence or absence of research funds supplied, the number of researchers, research methods, methods of data collection, themes and data analysis methods. Results : As for subjects, the largest group of the papers that numbered 69(20.7%) examined dental hygienists, and the second biggest group that numbered 65(19.5%) examined dental hygienists and students. The third greatest group that numbered 47(14.2%) examined patients at dental hospitals and clinics. Concerning places of data gathering, schools(37.1%) were the most common places where data were collected, followed by dental hospitals/clinics(31.6%) and laboratories(7.4%). In terms of research design, research studies accounted for 88.5%, and experimental studies accounted for 11.5%. Research studies were far more prevalent. Concerning themes, there were 76 kinds of concepts that the studies dealt with, and the most dominant concepts were oral health awareness and behavior, which 34 studies focused on(9.6%). 10 studies or more were concerned with dental service, oral health status, dental hygiene education, infection control, oral health education, job satisfaction and stress. As to data analysis methods, frequency analysis was most dominant, followed by Chi-square test, t-test, analysis of variance, descriptive statistics, correlation analysis and regression analysis. Most of the studies made use of quantitative research methods. Conclusions : The effort by this study to analyze the papers included in the Journal of the Korean Society of Dental Hygiene to grasp research trends in the field of dental hygiene is expected to be of some use for the determination of the right directions of dental hygiene research in the future.

• The Journal of Engineering Geology
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• v.15 no.1
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• pp.29-39
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• 2005

For detecting a ground contamination survey, soil sampling method have been used a drilling or coring technique in general. However these methods are very difficult to systematically real-time monitoring of variation of contamination degree in field. ]'n this research frequency Domain Reflectometry (FDR) system was suggested and carried out to experimental approaches for determination of oil contamination on surface and underground. Experimental method using FDR method was discussed with feasibility of measurement in the laboratory column test. It is determined to degree of oil contamination due to response of dielectric constant re-lated with volumetric water content(θ/sub w/) and volumetric oil content( θ/sub al/ ) of saturated and unsaturated soil media. And physical properties such as effective porosity and oil residual ratio of saturated soil media were also measured through real-time monitoring works using installed FDR measurement sensors, which are defected characteristics of oil movement in the saturated soil media under the soil column tests. In the results of these experiments, a range of effective porosity was estimated to about 0.35 compared with initial porosity 0.40 of manufactured saturated soil media, which is also calculated to about 87.5% to the ratio of initial porosity to effective porosity. Finally oil residual ratio which is compared with volumetric water content and volumetric oil content was calculated about 62.5%.

• Applied Chemistry for Engineering
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• v.19 no.4
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• pp.407-412
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• 2008

As an activation procedure, in this study, the oxidation treatment of needle cokes with a dilute nitric acid and sodium chlorate $(NaClO_3)$, combined with heat treatment, was attempted. The structures of acid-treated and pyrolyzed coke were examined with XRD, FESEM, elemental analyzer, BET, and Raman spectroscopy. The behavior of double layer capacitance was investigated with the analysis of charge and discharge. The structure of needle coke treated with acid was revealed to a single phase of (001) diffraction peak after 24 h. On the other hand, thecoke oxidized by heat treatment was reduced to a graphite structure of (002) at $300^{\circ}C$. The distorted graphene layer structure, derived from the process of oxidation and reduction of the inter-layer, makes the pores by the electric field activation at the first charge, and generates the double layer capacitance from the second charge. The cell using pyrolyzed coke with 24 h acid treatment and $300^{\circ}C$ heat treatment exhibited the maximum capacitance per weight and volume of 33 F/g and 30 F/mL at the two-electrode system in the potential range of 0~2.5 V.

• Journal of the Korean Geotechnical Society
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• v.31 no.6
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• pp.71-82
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• 2015

Recently, due to the expansion of urban infrastructure for the citizen convenience, the shield tunnel construction has increased considering the civil complaints minimization and construction stability. Most shield tunnels are designed based on the assumption of the undrained condition that underground water does not inflow, but they are operated in the field as drained tunnels with drainage facility to drain underground water. Therefore, the drained condition needs to be considered in the shield tunnel design. It is also necessary to consider the weathered granite soil that is widely distributed throughout the country and consequently is encountered in most of construction sites. In this paper, the model test which can control total stress and pore water pressure and simulate the underground tunnel located in the weathered granite soil below ground water level is conducted. Total stress, pore water pressure and an inflow water into an inner pipe were measured using the testing device. Test results showed that the total stress in a drained condition was lower than in an undrained condition because pore water pressure decreased in a drained condition and an inflow water into an inner pipe was proportional to the loading stress in a drained condition. As a result, if a drained condition is considered in the shield tunnel design, the more economical design can be expected because of the stress reduction of the lining.