• Journal of Korean Society of Environmental Engineers
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• v.31 no.10
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• pp.927-932
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• 2009

Toxic and recalcitrant organic pollutants in wastewaters can be effectively treated when advanced oxidation and biodegradation are combined, ideally with intimate coupling, in which both processes occur simultaneously in the same system. One means to achieve intimate coupling is to coat nanoscale $TiO_2$ on the outside of macroporous biofilm carriers. This study investigated the kinetics of photocatalysis with $TiO_2$-coated porous carriers. The carriers were made of polyvinyl alcohol (PVA) and coated with $TiO_2$ using a low-temperature sol-gel process. The $TiO_2$-coated carriers catalyzed the oxidation of methylene blue (MB) effectively under irradiation of UV light. The overall reaction rate with adsorption and photolysis saturated at high MB concentration, and approached the adsorption rate, which was first order for all MB concent rations. This result indicates that adsorbed MB may have slowed photocatalysis by blocking active sites for photocatalysis. The overall kinetics could be described by a quasi-Langmuir model. The estimated maximum specific (per unit mass of $TiO_2$) transformation rate of MB by the $TiO_2$-coated carriers was four times larger than that obtained from slurry-$TiO_2$ reactors. This observation demonstrated that the $TiO_2$ present as a coating on the carriers maintained high efficiency for transforming recalcitrant organic matter via photocatalysis. These findings serve as a foundation for advancement of an intimate coupling of photocatalysis to biodegradation.

• Journal of Digital Convergence
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• v.18 no.9
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• pp.81-91
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• 2020

The logistics industry is a basic and strategic industry that supports the development of national economy and society. The purpose of this paper is to evaluate the logistics efficiency of 22 cities in Guangxi and Yunnan provinces in China, and to grasp the problems and constraints and present policy proposals to promote the transformation and upgrading of the industrial structure in Guangxi and Yunnan provinces. In this paper, five input indexes and four output indexes were selected and the data from 2016 to 2018 were analyzed through DEA method. According to the analysis, the logistics efficiency of Guangxi and Yunnan provinces is not bad overall, but the development of each region is not balanced and the level of logistics efficiency is quite different. And it is found that each city needs to further improve the level of scale because the input and production structure of logistics resources is unreasonable. The limitation of this study is that it is difficult to generalize the analysis results because only the data over the past three years have been analyzed. It is necessary to comprehensively implement longitudinal and transverse analyses by extending the future analysis period over a long period of time.

• Journal of the Korean Association of Geographic Information Studies
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• v.20 no.4
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• pp.115-125
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• 2017

In current, as the release of national base map with an equivalent scale and accuracy for the whole territory areas in South Korea, rapid spatial information industry such as national land development, GIS, and car navigation are used in a variety of spatial information industry as decision making method, and a lot of research and policies are proposed for the wide expansion of spatial information industry. For this, as of 2013, it contributes to the latest trend of spatial information field in order to solve the problems for the latest trend of spatial information, replacing modification of base maps as dividing the whole territory to zone with policy transformation by ordinary modifications. Therefore, this paper evaluates the possibility of modification and renewal of national base maps(scale: 1:5,000) using drones which currently get the limelight from a variety of research fields and industries. In particular, as a result of overlapping orthophoto, 3D point clouds extracted from images acquired by low-cost drones, and digital maps which are applied for the tasks of modification and renewal, it presents 0.2m precision and 0.1m accuracy. This means that drone-based photorgammetry technique can be fully utilized in the tasks of digital map modification and renewal because it conforms the error range of work regulation in making the national base maps(scale 1: 5000).

• The Proceedings of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.9 no.2
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• pp.58-67
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• 1995

The paper describes the variation of magnetic fields caused by the operation of induction motors. The measuring system consists of the self-integrating magnetic field sensor, amplifier, and active integrator. From the calibration experiments, the frequency bandwidth of the magnetic field measuring system ranges from 20[Hz] to 300[kHz] and sensitivity is 0.234(mV/$\mu\textrm{T}$]. The magnetic fields generated under steady state and starting operations of duction motor are recorded by the proposed measuring system, and the fast Fourier transformation(FFT) of the measured data is performed to analyze the harmonic components. A single pulsed magnetic field is strongly caused by direct starting the induction motor, and its peak value is greater than 5 times as compared with the steady state value. The long transient duration and high intensity originates from the large inductance and dynamic characteristic of the induction motor, During the steady state operation of induction motor, subharmonics of magnetic field components, which depend on the pole number of induction motor, are observed. The lower order power-line harmonics can be inferred from the voltage flicker and current ripple which are derived from the torque fluctuation of induction motor. In the case of the induction motor drived by inverter, the harmonics of magnetic field are much more than those caused by direct starting method and are found generally to increase with decreasing the driving frequency.

• Clean Technology
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• v.18 no.1
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• pp.83-88
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• 2012

In order to improve the stability of ${\gamma}-Al_2O_3$ on hydrolysis of $SF_6$, the catalytic promoters were investigated in this study. The crystal phase of ${\gamma}-Al_2O_3$ is transformed to their ${\alpha}$-phase during hydrolysis of $SF_6$. Various metal oxides were applied as the promoter material that is Ga, Mg, and Zn and the promoter of 1, 5, and 10 wt% was impregnated over ${\gamma}-Al_2O_3$ by the impregnation method. Specially, it were confirmed in the catalytic activity tests and XRD analysis that ZnO/${\gamma}-Al_2O_3$ catalyst had the high activity for decomposition of $SF_6$ by catalytic hydrolysis and the crystal phase of ZnO promoted ${\gamma}-Al_2O_3$ was not transformed. From these results, it could be known that the stability of ${\gamma}-Al_2O_3$ is enhanced with the catalytic promotion of ZnO impregnated over the surface of catalyst.

• Korean journal of applied entomology
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• v.24 no.2 s.63
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• pp.85-95
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• 1985

It has been tried to find effective biological control measures involved in nature of soil suppressiveness to fusarium wilt of cncumber caused by Fusarium oxysporum f. sp. cucumerinum Owen. Total 28 soil samples were obtained from Jinju, Haman, Namji, Milyang and Suncheon vinyl house area. The disease response of test soil was quantified in terms of DI50 value which caculated from log-probit transformation of diseases response curves. Soils designated 5 from Jinju, 7 from Suncheon, 22 from Namji were recognized as suppressive to fusarium wilt of cucumber. This suppressiveness was completely nullified after autoclave. The disease suppressiveness of tested soil did not indicate any consistency according to either chemical property or texture of soil. Conidial germination, induction and germination of chlamydospore were markedly inhibited in supprerssive soil compared to those in intermediate or conducive soils, however, mycelial lysis did not appear to have direct relationship with disease suppressiveness of given soil. Population density of fluorescent Pseudomonads and Bacillus spp. in the soil originated from different degree of suppressiveness were not different significantly but the number of lytic bacterial plaques measured by triple layer agar method was remarkably higher in suppressive soil than that in intermediate or conducive soil.

• Journal of the Institute of Electronics Engineers of Korea CI
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• v.45 no.5
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• pp.102-109
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• 2008

In this paper, the robust hybrid modulation type classifier which use both HOS and WT key features and can recognize 10 digitally modulated signals without a priori information in multipath fading channel conditions is proposed. The proposed classifier developed using data taken field measurements in various propagation model (i,e., rural area, small town and urban area) for real world scenarios. The 9 channel data are used for supervised training and the 6 channel data are used for testing among total 15 channel data(i.e., holdout-like method). The Proposed classifier is based on HOS key features because they are relatively robust to signal distortion in AWGN and multipath environments, and combined WT key features for classifying MQAM(M=16, 64, 256) signals which are difficult to classify without equalization scheme such as AMA(Alphabet Matched Algorithm) or MMA(Multi-modulus Algorithm. To investigate the performance of proposed classifier, these selected key features are applied in SVM(Support Vector Machine) which is known to having good capability of classifying because of mapping input space to hyperspace for margin maximization. The Pcc(Probability of correct classification) of the proposed classifier shows higher than those of classifiers using only HOS or WT key features in both training channels and testing channels. Especially, the Pccs of MQAM 3re almost perfect in various SNR levels.

• Polymer(Korea)
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• v.36 no.4
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• pp.531-535
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• 2012

Conductive polyaniline (PANI) nanofibers in UV-curable resin were used for a transparent conductive film. The emeraldine-salt PANI (ES-PANI) nanofibers were prepared by chemical oxidation polymerization of aniline, which could be changed into emeraldine-base PANI by dedoping. EB-PANI nanofibers as a precursor for conductive fillers were thereby transformed into re-dpoed PANI (rES-PANI) by dodecylbenzenesulfonic acid in the UV-curable resin solution. rES-PANI nanofibers have high conductivity and long-term stability in the solution without a defect of nanostructure. The resulting conductive resin solution was proved to be highly stable where no precipitation of rES-PANI fillers was observed over a period of 3 months. The transparent film was spin-casted on a poly(methyl methacrylate) sheet of thickness ca. $5{\mu}m$. A surface resistance of $6.5{\times}10^8{\Omega}/sq$ and transmittance at 550 nm of 91.1% were obtained for the film prepared with a concentration of 1.4 wt% rES-PANI nanofibers in the solution. This transformation process of rES-PANI from ES-PANI by dedoping-redoping can be an alternative method for the preparation of an antistatic protection film with controllable surface resistance and optical transparencies with the PANI concentration in UV-curable solution.

• Korean Journal of Food Science and Technology
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• v.16 no.2
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• pp.242-250
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• 1984

Flavor components extracted from eighty species of Korean ordinary soy sauce were analyzed by gas chromatography. The relationship between the sensory scores of soy sauce flavor and the gas chromatographic data transformed with variables were analysed by method of multiple regression analysis. Simple correlation between values of each peak and sensory scores were totally low. The tenth and 12th peak had the highest correlation, 0.331. Determination coefficients of data obtained by transformation of each variables were not significantly different from each other. Flavor of soy sauce was explained about 56% at step 16 in case of stepwise multiple regression analysis of absolute values. The fact that the minimum standard errors of an estimate was found at the 16th step suggests the importance of selecting of independent variables from the whole gas chromatogram together with the results of F ratio. In the contributing proportion of each peak examined, peak 10 and 12 were contributing mainly to the good flavor of soy sauce.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.27 no.2
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• pp.169-175
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• 2009

According as standard of measurement is changed to world geodetic system by surveying law revision, we need to transform previous 1/1,000 digital maps as a standards of world geodetic system. And, we should acquire standard strategy to minimize confusion and error by conversion of geodetic surveying standards. Thus, conversion of digital maps must be transformed efficiently and consistently according to notice of relevant standard. As common point, we have used 1/1,000 digital map and local geodetic system coordinates and world geodetic system coordinates that had been used in UIS business of Pusan city and, make a analysis of distortion quantity using KASM Trans Ver 2.2. As the result of distortion quantity calculation about all Pusan city, numbers of area that error is over 0.05m are 35 in case of X(N) and 43 in case of Y(E). Because some business section have especially much error, we divided into 3 areas, that was A,B,C, and analyzed. As a result of analysis, errors of more than 0.05m are occurred only 1 X(E) in the B area and 1 X(N) and 1 Y(E) in the C area. In conclusion, We think It is a good method that we consider a distortion quantity and divide a region, and transfer to world geodetic system for large area like Pusan city.