• Journal of Soil and Groundwater Environment
• /
• v.17 no.6
• /
• pp.33-42
• /
• 2012

This study was performed to find the problems according to interference factors (organic matter, pH, Cr, Mn, Fe, clay, and etc.) when we analyzed the hexavalent chromium [Cr(VI)] in soils using UV/VIS spectrometer (US EPA 7196A), attempted to evaluate the domestic applicability of analytical method (US EPA 7199) using IC-UV/VIS spectrometer as alternative method. The recovery rate of certified reference materials was 75.0% (US EPA 7196A) and 101.4% (US EPA 7199) by the analytical methods. As the results of performing QA/QC about US EPA 7199, method detection limit (MDL) and limit of quantification (LOQ) were 0.062 mg/kg, 0.196 mg/kg, respectively. The LOQ of US EPA 7199 was lower than that of the current soil official testing method in Korea (0.5 mg/kg). Cr(VI) contents in 23 soil samples were compared by the analytical methods of EPA 7196A and 7199. Cr(VI) was detected in 13 of 23 soil samples by EPA 7196A, while EPA 7199 was not detected in any soil samples. The Cr(VI) content in 23 soil samples by EPA 7196A was not clearly correlated with Cr, Fe, Mn and clay content in the soil samples. However, the contents of Cr(VI) and organic matter of the soil samples had the highest coefficient of determination ($R^2$) of 0.80. In order to evaluate the correlation between the recovery rates of Cr(VI) and organic matter contents in the soil samples, the recovery rates of 5 soil samples added Cr(VI) standard solution were analyzed by the analytical methods. According to the results, the higher the organic matter contents in soil samples, the lower the recovery rates of Cr(VI) by US EPA 7196, while in case of US EPA 7199, the recovery rates were stable regardless of the organic matter contents.

• Journal of the Korean Vacuum Society
• /
• v.18 no.5
• /
• pp.358-364
• /
• 2009

We investigated the growth of ZnO thin films with prominent emission characteristics through minimizing the formation of defects by using pulsed laser deposition (PLD). To do so, the ZnO films were deposited on sapphire(0001) substrates at the substrate temperature of $400-850^{\circ}C$ and then the variation of their structural and optical properties were analyzed by x-ray diffraction, atomic force microscope and photoluminescence. As a result, all ZnO films were grown with c-axis preferential orientation irrespective of the substrate temperature. However, the crystallinity and stress state were dependent on the substrate temperature and the ZnO film deposited at $600^{\circ}C$ showed the best surface morphology and crystallinity with nearly no strain. And also this film exhibited outstanding emission characteristics from the viewpoint of full width half maximum of UV emission peak as well as visible emission due to defects. These results indicate that the emission characteristics of the ZnO films are strongly related to their structural characteristics influenced by substrate temperature. Consequently, ZnO films with strong UV emission and nearly no visible emission, which are applicable to UV emission devices, could be grown at the substrate temperature of $600^{\circ}C$ by PLD.

• Journal of the Korean Institute of Gas
• /
• v.27 no.1
• /
• pp.70-77
• /
• 2023

Air environment regulations have been strengthened due to increasing air pollutant emissions, the target of reducing emissions has increased and interest in gas measurement methods is also increasing. The sampling method is mainly used, but due to the spatial and temporal measurement limitations, the laser absorption spectroscopy which is a real-time and in-situ method is in the spotlight. In this study, we studied the wavelength modulation spectroscopy and described the calibration-free algorithm. The developed algorithm was modified to reflect 46 multi-absorption lines and was applied to light absorption signal analysis in visible and mid-infrared regions. In addition, the difference between the modulation parameters of laser was analyzed. As a result of reviewing the performance through O₂ and NO gas measurement experiments of various concentration conditions, the linearity was R²_O2=0.99999 and R²_NO=0.99967.

• Journal of the Korean Society for information Management
• /
• v.24 no.3
• /
• pp.321-341
• /
• 2007

It will be possible to prevent the infringement of the trademarks and the insueing disputes regarding the originality of the trademarks by using an efficient content-based trademark image retrieval system. In this paper, we describe a content-based image retrieval system using the Self Organizing Map(SOM) algorithm. The SOM algorithm utilizes the visual features, which were derived from the gray histogram representation of the images. In addition, we made the objective effectiveness evaluation possible by coming up with a quantitative measure to gauge the effectiveness of the content-based image retrieval system.

• The Transactions of the Korea Information Processing Society
• /
• v.7 no.5
• /
• pp.1559-1569
• /
• 2000

CHILL96 is recommended as development language for telecommunication systems by ITU-T. In this paper, we describe the design and implementation of CHILL96 compiler using C++ intermediate code. Translation rules from CHILL96 to C++ are designed for code generation. The CHILL96 compiler is composed of four parts such s syntax analyzer, visibility checker, semantic analyzer and code generator, and each part has very close relationship with symbol table and abstract syntax tree. Performance evaluation has been performed for feasibility study. After performance evaluation, we conclude the CHILL96 compiler using C++ intermediate sho good performance compared with other CHILL compilers. In addition to high performance and portability, the CHILL96 compiler using C++ intermediate code helps application developers to maintain and enhance telecommunications software by translating CHILL96 program to C++ program.

• Fire Science and Engineering
• /
• v.28 no.6
• /
• pp.90-98
• /
• 2014

Lately accidents of harmful chemical substance in korea were repeatedly replaying. We studied problems and preparation plan in 2008 years~2014 years through analysis cases of harmful chemical substance. Leakage of chemical substance's accident situation shows that leakage in the workplace is the most 10 cases, accounting for 58.6% is the largest proportion in 2009. Leakage according to explosion accounting for 50% (5 cases) in 2004, 25% (4 cases) in 2007 and 33.3% (4 cases) in 2011 has very irregular change. Therefore, A major cause of accidents is lack of safety management. Harmful chemical substance showed various aspects, high residual substance and non-visible characteristic so response and recovery was easy. And the second damage to move a distance causes environment pollution. So a mutual-assistance system and integrated system of related organization have to build and expert of chemical incident response and therapist of chemical substance response have to establish to do efficient and rapid response.

• Korean Journal of Optics and Photonics
• /
• v.11 no.3
• /
• pp.147-151
• /
• 2000

We deposited the ion assisted ${Ta_2}{O_5}$ films and conventional thermal evaporated ${Ta_2}{O_5}$ films by using electron beam gun, and measured the optical properties and mechanical properties of the fabricated films according to the evaporation conditions. In the case of the TazOs films by oxygen ion assisted deposition with the anode voltage of 120 V, and current density of $50~500\muA/cm^2$, the refractive index exhibited 2.15 which was higher than the conventionally deposited film index 1.94 and the tensile stress exhibited $5.0\times10^8 dyne/cm^2$ which was lower than $7.0\times10^8 dyne/cm^2$. This properties coincided with the optical and mechanical properties of the films deposited at the elevated substrate temperature of $230^{\circ}C$. In the case of the argon ion assisted films the tensile stress was decreased but the absorption existed at the short wavelength in the visible spectral region. And all the fabricated films were found to be amorphous by the X-ray diffraction analysis. lysis.

• Korean Journal of Social Welfare
• /
• v.62 no.1
• /
• pp.55-81
• /
• 2010

Self-sufficiency of the female victims of prostitution has been understood as a 'result' at a particular moment focusing on an economic self-sufficiency. Overcoming such limitation, this study originates from a problem posing that evaluating self-sufficiency of the female victims of prostitution should be approached as a series of 'processes' in which experiences of the victims are integrated. The methodology of the study included a questionnaire survey with questions designed based on the self-sufficiency experiences which were analyzed through an in-depth interview with 34 female victims of prostitution. The questionnaire survey was conducted with 243 female victims of prostitution, and construct validity and reliability were verified. As a result of an exploratory factor analysis, a validity of scale in four factors and 24 questions was verified. A reliability of each factor was high ranging from .823 to .871. It could be achieved to make a relatively invisible process of self-sufficiency visible by developing the scale. Subsequently it complements the existing concept of self-sufficiency and overcomes limitations of measuring its results, hence reflecting the reality of the self-sufficiency practices.

• Polymer(Korea)
• /
• v.35 no.5
• /
• pp.402-408
• /
• 2011

To improve $Na^+$-saponite(SPT) film flexibility, we prepared SPT hybrid clay films with various poly(vinyl alcohol) (PVA) concentrations(0~10 wt%) using the solution intercalation method. In this study, we investigated the thermo-optical properties, morphology, and gas permeability of the SPT hybrid films. We also examined the relationship between the film properties and PVA content using wide angle X-ray diffraction measurements(XRD), field emission scanning electron microscopy(FESEM), differential scanning calorimetry(DSC), thermogravimetric analysis(TGA), thermomechanical analysis(TMA), ultraviolet-visible(UV-vis) spectroscopy, and oxygen transmission rate($O_2$TR) testing. The properties of the clay hybrid films were strongly affected by PVA filler content. The presence of a small amount of PVA was sufficient to improve the flexibility of SPT hybrid films.

• Journal of the Society of Disaster Information
• /
• v.17 no.1
• /
• pp.128-142
• /
• 2021

Purpose: This study examines the safety management of anchors that have already been constructed and evaluates the results of lift-off tests conducted at the site. The purpose of the project is to study countermeasures if necessary. Method: Compare the residual load gained after the lift-off test at 36 points behind the site with the preemptive load, allowable load, and design load. We also analyze stability through this and evaluate the stability of anchors. Results and Conclusion: The residual tension at 26 points remained stable. However, the residual load at 10 points was analyzed to be greater than the designed load and less than the allowable load, and it was evaluated as an instability that could cause fracture problems. Therefore, anchors with unstable conditions at 10 points should be monitored and monitored through periodic measurements and quality tests, and the anchor should be observed at the surrounding points as well as the relevant points to maintain stability.