• Journal of Ecology and Environment
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• v.38 no.2
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• pp.123-131
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• 2015

During several visits to the Cebu City landfill in the Philippines, plants were observed growing within the area, including on top of the garbage piles. Studying the response of these plants is important in assessing which can be used in remediating metal contaminated soils. This study aimed to determine whether the plants in the Cebu City landfill excluded or accumulated cadmium (Cd) and chromium (Cr) in the plant tissues. The floristic composition of the landfill was analyzed prior to the sample collection. The samples were acid-digested before the desired elements were measured using atomic absorption spectrophotometry (AAS). The Cd and Cr concentrations in the plant root-zone soil were also measured using AAS. The results indicated that the landfill substrate was generally acidic based on the results of the pH measurement. Of the 32 plant species sampled, Cyperus odoratus showed potential for Cd uptake and internal transfer; Cenchrus echinatus, Vernonia cinerea and Terminalia catappa for Cr uptake, and Cynodon dactylon for Cr internal transfer. The plants in the landfill differed in their response towards the heavy metals. To confirm the behavior of C. odoratus towards Cd, and C. echinatus, C. dactylon, V. cinerea, and T. catappa towards Cr, controlled experiments are recommended, as the plant samples analyzed were collected from the field.

• Journal of Korean Society for Atmospheric Environment
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• v.15 no.3
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• pp.291-303
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• 1999

The purpose of this experimental study is to investigate seasonal deposition flux variations of the total dustfall and various inorganic elements in it. Total of 84 dustfall samples were collected from September, 1997 thur August, 1998 at 7 different sites in Kunsan. Each sample was analyzed by an AAS to determine the levels of 5 inorganic elements Zn, Cd, Cr, Fe and Pb. Deposition fluxes, soluble/total fractions for each element were extensively investigated. Estimated depositon fluxes of dustfall and elements in Kunsan were in the range of 37.5~45.1 ton/$ extrm{km}^2$/yr for dustfall, 43.5~81.8kg/$\textrm{km}^2$/yr for Zn, 6.6~11.0kg/$\textrm{km}^2$/yr for Cd, 44.8~110.0kg/$\textrm{km}^2$/yr for Cr, 223~323 kg/$\textrm{km}^2$/yr for Fe, 10.9~22.3 kg/$\textrm{km}^2$/yr for Pb, respectively. Thus, the estimated average total deposition fluxes of dustfall in Kunsan(376.35$\textrm{km}^2$) per day were 43.3 ton and 58.6 kg for Zn, 8.9 kg for Cd, 80.6 kg for Cr, 293.8 kg for Fe and 14.1 kg for Pb, respectively.

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.12 no.1
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• pp.70-76
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• 2013

Recently, the performance and function of electrical and electronic system in automotive vehicles is developing at a rapid rate with the advancement of IT technologies. Combined together with micro-controller and sensor technologies, the Vehicle Smart System (VSS) being developed to improve driver's convenience and comfort has been employed to a variety of applications. In addition to the convenience system, the Auto-parking Assistance System (AAS) that is now attracting a new attention has been already applied to some vehicles, but it is currently limited to luxury car models only. In this paper, we present a fuzzy controller that enables autonomous parking assistance without the AAS. The controller can perform the assistance with information provided from moving status, current position and steering angle as one is able to park a car based on his/her experience and knowledge for driving and parking. We have evaluated its performance of the proposed controller by simulation and tested the excellence of the controller by building a model vehicle embedded with the micro-controllers.

• Journal of the Korea Society of Computer and Information
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• v.7 no.2
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• pp.9-18
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• 2002

SECOS(SoonChunHyang E-Commerce System) is the e-commerce system which was developed by e-commerce software research center in soonchunhyang univ. The system was composed of payment system, retrieving system and framework being used to combine these systems. The modules in the system was composed of components which was developed by CBSE(Component Based Software Engineering) method. In this paper. we implement the Role Based Access Control(RBAC) component for access control of SECOS. We use Attribute Certificates(ACs) in order to implement RBAC in the distributed retrieving system, and implement Attribute Authorities(AAs) which can provide ACs. The Proposed system is implemented by EIB component based JAVA.

• Journal of the Korea Institute of Building Construction
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• v.18 no.3
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• pp.267-275
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• 2018

This study is to investigate the effect of various temperature and humidity conditions on the strength and efflorescence of alkali activated slag cement(AAS) using the red mud. As a result of examining the strength and efflorescence characteristics of AAS mixed with red mud according to the curing conditions, The compressive strength and flexural strength were the highest at 28 days, but the absorption rate, efflorescence area and soluble $Na^+$ elution were lowest in standard wet curing compared to the air curing, high temperature curing and low temperature curing.

• Advances in environmental research
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• v.3 no.4
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• pp.293-306
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• 2014

The present study primarily focuses on the evaluation of the comparative effect of chemical coagulation and ultrasonication for elimination of aromatic amines (AAs) present in anaerobically pretreated textile wastewater containing different types of dyes including azo dyes. Color and COD reduction was also monitored at the optimized conditions. The production of AAs was measured spectrophotometrically in the form of total aromatic amines (TAAs) and also verified with high performance liquid chromatography (HPLC) selectively. A composite coagulant, magnesium chloride (MC) aided with aluminium chlorohydrate (ACH) in an equal ratio (MC + ACH) was utilized during the coagulation process, which yielded 31% of TAAs removal along with 85% of color and 52% of COD reduction. At optimized power (200 W) and sonication time (5 h), an appreciable TAAs degradation efficiency (85%) was observed along with 51% color reduction and 62% COD removal using ultrasonication. The chromatographic data indicate that sulphanilic acid and benzidine types of aromatic amines were produced after the reductive cleavage of utilized textile dyes, which were effectively mineralized after ultrasonication. The degradation followed the first order kinetics with a correlation coefficient ($R^2$) of 0.89 and a first-order kinetic constant (k) of $0.0073min^{-1}$.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.9 no.8
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• pp.1762-1767
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• 2005

PKI provides good resolutions for the authentication of user in the situation not to meet each other, but it is not enough to provide the resolution of authorization in distributed computing environments. Especially, we offer a variety forms of the user Authentication, the Integrity and a security service of the Non-Repudiation, but an authorization Policy, because of the complexity with a lot of information, using m understandable XML, makes a simple and easy certificate to read, and we get the information from DOM fee and do a XML analysis and stardardized-method usage easily In this paper, we provide the AAS model being able to use with the solution of the distributed users' authorization, and we implement an authorization policy module, using XML. in the Linux-based Apache Web server.

• Journal of Pharmaceutical Investigation
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• v.29 no.3
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• pp.171-177
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• 1999

Lidocaine(2-Diethylaminoaceto-2', 6'-xylidide) was transdennally delivered by iontophoresis and the effect of enhancer on the delivery of lidocaine was studied. We delivered lidocaine through the skin of hairless mouse using diffusion cell and investigated the effect of the amount of cation salts such as sodium chloride, calcium acetate, zinc acetate and aluminum acetate on the drug delivery. The amounts of transported drugs and adsorbed metal ions were measured by HPLC(High Perfonnance Liquid Chromatography) and AAS(Atomic Absorption Spectrophotometry), respectively. The addition of zinc acetate and aluminum acetate greatly enhanced the delivery of lidocaine. The detection of two metal ions by AAS seemed to support the idea that the astringency effect of these ions were the main reason for the enhancement of transdermal delivery.

• Economic and Environmental Geology
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• v.25 no.2
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• pp.145-151
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• 1992

In order to study the optimum depth for the soil geochemical exploration in the area which is affected by agricultural activities and waste disposal of metal mine, the soil samples were sampled from the B layer of residual soil and vertical 7 layers up to 250 cm in the rice field and 3 layers up to 90 cm in the ordinary field. They were analyzed for Au, As, Cu, Pb and Zn by AAS, AAS-graphite furnace and ICP. To investigate the proper depth for the soil sampling in the contaminated area, the data were treated statistically by applying correlation coefficient, factor analysis and trend analysis. It is conclude that soil geochemical exploration method could be applied in the farm-land and a little contaminated area. The optimum depth of soil sampling is 60 cm in the ordinary field, and 150~200 cm in the rice field. Soil sampling in the area of a huge mine waste disposal is not recommendable. Plotting of geochemical map with factor scores as a input data shows a clear pattern compared with the map of indicater element such as As or Au. The second or third degree trend surface analysis is effective in inferring the continuity of vein in the area where the outcrop is invisible.

• Elastomers and Composites
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• v.30 no.3
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• pp.229-234
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• 1995

Membrane process has been applied widely to petroleum chemistry, fine chemistry, polymer, electronics, food, bioprocessing, and wastewater treatment process. Membrane process has advantage that there's no phase change through separation, energy consumption is smaller than other separation processes. And equipment investment and operation cost are inxpensive too. We prepared the silicone rubber membrane and then separated the heavy metal ion from wastewater. Silicone rubber membrane was prepared using a superitical fluid process and heavy metal ions were separated from the chromium nitrate, ferric sulfate, cupric sulfate, nickel sulfate aqueous solution. The pressure difference between top and bottom of separation apparatus was preserved by vacuum pump, and the removal amount of heavy metal at each separation step were analyzed by instrumental analysis, AAS. The surface and pore of silicone rubber membrane was investigated using SEM, and the capability of wastewater treatment using a silicone rubber membrane was proposed as calculated removal rate of heavy metal after comparing removal amount of heavy metal to amount of heavy metal in mother solution by AAS analysis.