• Korean Journal of Soil Science and Fertilizer
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• v.29 no.3
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• pp.312-320
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• 1996

This study was to investigate the changes of phytotoxicity of food waste during composting at an aerated static pile for 80 days. The concentration of sodium in the final compost increased by more than 30% and almost of the sodium was a water soluble type which corresponds to about 94% of the total concentration. Major volatile fatty acid(VFA) produced during the composting was acetic acid and also somewhat of butyric acid. High concentration of acetic acid during the composting was kept up for a month and then decreased progressively. It suggests that the phytotoxicity by the VFAs produced during composting of food waste could be removed through a stabilization process in a period of about 40 days. From the statistical analysis between germination index(G.I.) and VFAs. or G.I. and sodium, the phytotoxicity of food waste samples was more dependent in the changes of acetic acid concentration than that of sodium concentration. Considering low G.I. value in the final food waste compost which is matured completely, however. the agricultural utilization of the food waste compost may be to have a big problem due to excess sodium of the compost which is impossible to remove by composting and seriously inhibits growth of plants.

• Journal of Korean Society of Transportation
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• v.23 no.5 s.83
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• pp.123-134
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• 2005

This research aims at developing a new method which can replace the existing method. known as the quality factor(Q factor) method by an L-R-C test for use in the performance test of inductive loop detectors(ILD) being installed and maintained. In this study, a sensor to detect a magnetic field in terms of frequency and intensity, a method to collect field data, the method of analysis, and the method of diagnosis were developed. An automatic diagnosis system which was developed to overcome those drawbacks has the following features : First, field data is collected automatically by a test vehicle equipped with magnetic field sensors that is running can be said to along the roadway and. thus, the new system completely overcome the roadway and, thus, the new system can be said to completely overcome the inefficiency of the existing method second, since the magnetic fold generated from the ILD is the final output of the whole system of ILD, the existing problem has been solved. third. since each of the detection area by height is collected by the magnetic sensors installed by height. a basic for the identification of the vehicle types to be detectable and the setting of adjustment factors has been made. For the automatic diagnosis system developed during in this study, a reliability test was carried out by comparing vehicle times of ILD installed ideally.

• Journal of Korean Society of Transportation
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• v.25 no.3
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• pp.145-154
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• 2007

Determining stop spacing is a very important process in transit system planning. This study is involved in an analytical approach to decide the transit stop spacing. Transit stop spacing should be longer as 1) user access speed, 2) user travel time, and 3) dwell time increase, and shorter as 1) passengers (boardings and alightings) and 2) headway increase. In this study, a methodology is proposed to determine transit stop spacing to minimize total cost (user cost plus operator cost) with irregular passenger distribution (boardings and alightings) Without considering in-vehicle passengers, the transit stop spacing should be shorter in the concentrated sections of the passenger distribution than in others to minimize total cost. Through the conceptual analysis, it is verified that the transit stop spacing could be longer as the in-vehicle passengers increase in certain sections. This study proposes a simple practical method to determine transit stop spacing and locations instead of a dynamic programming method which generally includes a complex and difficult calculation. If the space axis is changed to a time axis. the methodology of this study could be expanded to analyze a solution for the transit service (or headway) schedule problem.

• Journal of the Korea Organic Resources Recycling Association
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• v.10 no.1
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• pp.128-138
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• 2002

Waste recyling is a very important concept with waste minimization in the waste managment. Especially, recycling waste from the point of environmental and economical view is useful. The recycling part of package waste needs to continuously grow. But, cosmetic container, which is continuosly increased as waste. The difficulty of waste treatment in cosmetic industy produces complicated environment problem. Cosmetic container is difficult to recycle because it mostly made of complex material. Also, cosmetic container is difficult to separate I source and thus usually are generated mixed waste. In this study we performed an analysis on the Recycling Improvement method of a Cosmetic Container The result of this study could be summarized as follows 1) As a part of law and a system improvement, must be achieved Improvement Cosmetic law, Deposit refund system. and charge system, Technology development for recycling of a cosmetic container, Extension of refill productions, Recovery system establishment of a cosmetic container and inducement of a maker's recycling paticipation. 2) As a part of a cosmetic container design improvement, must be achieved simplification and standardize of container's cuality, Cosmetic life cycle extension, Selection of recycling materials and Cosr reduction of a cosmetic container. In conclusion, To the recycling improvement of a cosmetic container, must be achived collective development of system improvement, participation of the government and company and a consumer's recycling consciousness. Most of all, A company need to try to recycling container development of a cosmetic container.

• Journal of the Korean Society of Hazard Mitigation
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• v.10 no.1
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• pp.35-42
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• 2010

The rapid economic development induced the massive road constructions, becoming bigger and high-speed of the vehicles. However, it brings lots of social problems, such as air pollutions, traffic noise and vibration. Special concrete block for the base course of asphalt pavement is needed to decrease traffic noise such as tire's explosive and vehicles sound, applying Helmholtz Resonators theory to asphalt pavement. If it is applied to the area where it happens considerable noise such as a junction, the street of a housing complex and a residential street, it is one of considerable method to solve the social requirements of noise problem. This research examines couple of laboratory tests for the sound absorption effect of the concrete block and the base concrete block. There are specimens which is fixed hall-size, space, depth as the condition of this research, and these are analysed of noise decrease effect using different condition of the first noise of each vehicle. As a result of analysis data according to vehicle noise volume, measurement distance, a form and size of the hall using the base concrete block, the use of special concrete base showed a good alternative solution for decreasing traffic noise level, from 4 dB to 9 dB.

• Journal of Korea Water Resources Association
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• v.51 no.8
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• pp.677-686
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• 2018

There remain numerous ungauged watersheds in Korea owing to limited spatial and temporal streamflow data with which to estimate hydrological model parameters. To deal with this problem, various regionalization approaches have been proposed over the last several decades. However, the results of the regionalization models differ according to climatic conditions and regional physical characteristics, and the results of the regionalization models in previous studies are generally inconclusive. Thus, to improve the performance of the regionalization methods, this study attaches hydrological model parameters obtained using a spatial proximity model to the explanatory variables of a regional regression model and defines it as a hybrid regionalization model (hybrid model). The performance results of the hybrid model are compared with those of existing methods for 37 test watersheds in South Korea. The GR4J model parameters in the gauged watersheds are estimated using a shuffled complex evolution algorithm. The variation inflation factor is used to consider the multicollinearity of watershed characteristics, and then stepwise regression is performed to select the optimum explanatory variables for the regression model. Analysis of the results reveals that the highest modeling accuracy is achieved using the hybrid model on RMSE overall the test watersheds. Consequently, it can be concluded that the hybrid model can be used as an alternative approach for modeling ungauged watersheds.

• Korean Journal of Microbiology
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• v.41 no.2
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• pp.105-111
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• 2005

Streptomyces produces many kinds of secondary-metabolites including antibiotics. Screening of a new compound and elucidation of a biosynthetic pathway for the secondary metabolites are very important fields of biology, however, there is a main problem that most of the identified compounds are already researched compounds. To solve these problems, a microarray system that is based on the data related to the biosynthetic genes for secondary-metabolites was designed. For the main contents of DNA microarray, the important genes for the bio-synthesis of aminoglycosides, polyenes group, enediyne group, alpha-glucosidase inhibitors, glycopeptide group, and orthosomycin group were chosen. A DNA microarray with 69 genes that were involved in the bio-synthesis for the antibiotics mentioned above was prepared. The usability of the DNA microarray was confirmed with the chromosomal DNA and total RNA extracted from S. coelicolor whose genomic sequence had already been reported.

• Journal of Institute of Control, Robotics and Systems
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• v.16 no.12
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• pp.1150-1158
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• 2010

In this study, the Polynomial-based Radial Basis Function Neural Networks is proposed as one of the recognition part of overall face recognition system that consists of two parts such as the preprocessing part and recognition part. The design methodology and procedure of the proposed pRBFNNs are presented to obtain the solution to high-dimensional pattern recognition problem. First, in preprocessing part, we use a CCD camera to obtain a picture frame in real-time. By using histogram equalization method, we can partially enhance the distorted image influenced by natural as well as artificial illumination. We use an AdaBoost algorithm proposed by Viola and Jones, which is exploited for the detection of facial image area between face and non-facial image area. As the feature extraction algorithm, PCA method is used. In this study, the PCA method, which is a feature extraction algorithm, is used to carry out the dimension reduction of facial image area formed by high-dimensional information. Secondly, we use pRBFNNs to identify the ID by recognizing unique pattern of each person. The proposed pRBFNNs architecture consists of three functional modules such as the condition part, the conclusion part, and the inference part as fuzzy rules formed in 'If-then' format. In the condition part of fuzzy rules, input space is partitioned with Fuzzy C-Means clustering. In the conclusion part of rules, the connection weight of pRBFNNs is represented as three kinds of polynomials such as constant, linear, and quadratic. Coefficients of connection weight identified with back-propagation using gradient descent method. The output of pRBFNNs model is obtained by fuzzy inference method in the inference part of fuzzy rules. The essential design parameters (including learning rate, momentum coefficient and fuzzification coefficient) of the networks are optimized by means of the Particle Swarm Optimization. The proposed pRBFNNs are applied to real-time face recognition system and then demonstrated from the viewpoint of output performance and recognition rate.

• Journal of the Institute of Electronics Engineers of Korea TC
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• v.39 no.2
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• pp.92-100
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• 2002

The 16-port feed waveguide array with inductive walls analyzed by Galerkin's method of moments are proposed for the DBS reception system mounted on vehicle. First of all, in order to verify the validity of electromagnetic analysis and design for a $\pi$-junction feed waveguide, it is designed and fabricated at DBS band. The measurement results of a $\pi$-junction feed waveguide agree well with the theoretical ones. Based on this design method, an array design for WR-90 standard waveguide is conducted. Since the width of a $\pi$-junction feed WR-90 standard waveguide is larger than a guided wave length in an array design, the difference of amplitude and phase of 8-port array are calculated 2.3 dB and 62 degrees, respectively. The bandwidth with return loss of -20 dB below is about 220 MHz and it doesn't satisfy DBS band. To solve this problem, we propose a novel design that the width of a $\pi$-junction feed waveguide equals to a guided wave length. By the proposed novel design for 8-port feed waveguide array, the difference of amplitude and phase are decreased 1 dB and 13 degrees, respectively. The broad bandwidth of 700 MHz is also realized. The size of 16-port waveguide away compared with WR-90 array is reduced about 10 cm. The measured antenna gain for the fabricated 16-port feed waveguide array is observed 24 dBi above at DBS band.

• Maxillofacial Plastic and Reconstructive Surgery
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• v.23 no.1
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• pp.31-39
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• 2001

The purpose of this study is to reveal the factors leading to the problem of unilateral condylar fractures and suggest a treatment guideline of treatment for good prognosis in surgical treatment. The factors can be age, sex, fracture site, degree of displacement, posterior occlusion loss, post-operative alteration of condylar head position, post-operative condylar head resorption, and maxillomandibular fixation period. One hundred and eleven patients with unilateral condylar fractures, who were treated by surgical method from 1990 Feb. to 2000 Feb., were studied. Minimum follow-up period was 6 months. The results were as follows ; 1. In the age group of $41{\sim}60$, females had significantly higher complication rate than males, therefore we must be careful about treatment of female in this age group 2. In level I fractures of the mandibular condyle, because there were abundant complications when the patients were treated with fragment removal, conservative treatment is recommended over the surgical approach. 3. There were no differences in the complication rate, in the level II, III fractures. but were severe complications in the cases of patients treated by Dr.Nam's method or fragment removal. Therefore, open reduction and internal fixation is recommended over Dr.Nam's method or fragment removal. 4. In level IV fractures, open reduction and internal fixation is recommended 5. Although there was a higher complication rate depending on the degree of deviation, there was no correlation between the degree of deviation and development of complications in each level of fracture 6. Because the complication rate was higher in cases of condylar resorption, vertical dimension loss, and alteration of condylar head position, we must make an effort to prevent such complications during treatment