• 한국환경과학회지
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• 제5권4호
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• pp.513-524
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• 1996

Laboratory investigation was conducted to evaluat the mixing effects on organic removal efficiency to treat low-strength synthetic wastewater using modified anaerobic - filter reactor combining anaerobic filter and upflow anaerobic sludge blanket. Using the modified process the low-strength wastewater like municipal sewage could be treated with 85% T-COD removal efficiency at hydraulic retention time of 6 hours. At the constant organic loading of 0.5 kg COD/m 3-day, the organic removal efficiency and effluent COD concentration are increased as influent COD concentration increased from 125 mg/l to 500 mg/l. Mixing effects on organic removal efficiency are evident and optimum mixing speed is found as 50RPM. Placing the granular sludge and media on which slime layer was pre-formed into the reactor seemed to be very effective In achieving short start-up period. Therefore, the steady state was achived after 4 weeks and 1 week based on T-COD and S-COD, respectively.

• 한국환경보건학회지
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• 제27권3호
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• pp.81-85
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• 2001

The aim of this study was to evaluate on the removal effect of total nitrogen and posphorus in municipal wastewater by decreasing hydraulic retention time(HRT) from 6 hour to 4 hour on CNR process using influent as a Carbon Source. CNR(Cilium Nutrient Romoval) is the process combining $A^2$/O process with cilium media of H2L corporation. The removal efficiencies for BOD$_{5}$, T-N and T-P were 81.1%, 61.4%, 61.4%, respectively. The removal efficiency of nitrogen and posphorus were low by decreasing hydraulic retention time(HRT) from 6 hour to 4 hour on CNR process.s.

• 한국환경보건학회지
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• 제26권3호
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• pp.98-102
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• 2000

The aim of this study was to evaluate on the removal effect of total nitrogen in municipal wastewater by decreasing hydraulic retention time(HRT) from 6 hour to 4 hour on CNR process. CNR-A(Cilia Nutrient Removal) is the process combining A2/O process with cilium media of H2L corporation. The removal efficiencies for T-N were 63.1% in A-1 reactor, and 73.5% in A-2 reactor and 77.0% in A-3 reactor. The specific nitrification(g-NH3-N/g-MLVSS.d) of Oxic in CNR-A process was 0.07-0.32. The specific denitrification in Anoxic and the specific nitrification inOxic was higher in HRT 4 hour because of optimum F/M ratio.

• 한국실내디자인학회논문집
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• 제16권2호
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• pp.339-346
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• 2007

This thesis has purpose of explaining that light is not only appreciated but also physically percepted in contemporary space design and examining effects of space experience through the physical perception. In keeping with such developments, light has been perceived as the object of another architectural tool in modern space design and has provided men with new experience by providing space image and function different from previous ones. With the expansion of the area of light, light has changed a space that is not a simple architectural factor into the essential concept that gives the architectural space image ! by combining it with architectural space, structure, form and materials throughout the whole process from the beginning to the completion. Through phenomenological approach, light is percepted and experienced by body movement, intervention of senses and memories, and passing of time. The percepted and experienced light brings increase of mutual understanding in space, activation and continuance of user's sensation, recreational experience by event occurrence and space experience effect thorough information from media.

• 한국안전학회지
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• 제17권1호
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• pp.68-71
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• 2002

A research on accident loss calculation for polyol process without safety management activities, and safety cost estimation using process risk assessment has been implemented. In order to estimate a magnitude of loss, accident scenarios were made by combining result made from HAZOP Study method with accident possibility analysis results implemented with FTA. Also effect assessment was implement for accident consequence of each scenario. And minimum possible loss cost has been calculated when safety investment do or not. Result from cost-benefit analysis was shown as approximately \335 billion(=USS44,000 billion), as cost after subtracting safety management cost from minimum possible loss cost.

• Journal of Communications and Networks
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• 제18권5호
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• pp.773-783
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• 2016

Both coordinated multi-point transmission and frequency reuse are effective approaches to mitigate inter-cell interference and improve network coverage. The motivation of this work is to explore the manner to effectively utilize the spectrum resource by reasonably combining cooperation and frequency reuse. The $Mat{\acute{e}}rn$ cluster process, which is appropriate to model networks with hot spots, is used to model the spatial distribution of base stations. Two cooperative mechanisms, coherent and non-coherent joint transmission (JT), are analyzed and compared. We also evaluate the effect of multiple antennas and imperfect channel state information. The simulation reveals that the proposed approach to combine cooperation and frequency reuse is effective to improve the network coverage for users located at both the center and the boundary of the cooperative region.

• 농촌계획
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• 제12권3호
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• pp.67-80
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• 2006

The concept of RIS(Regional Innovation System) has widely been used in discourse and policy issues in Korea. But most studies of RIS concern on BT or IT industries combining with diverse regional agencies in urban areas. Some other studies were concentrated on general ideas or concept of the RIS. The purposes of this study are (1) to suggest a analytical method to select specialized industry in local autonomy, (2) to analyze the relationship between specialized industry and gross sales of agricultural products and stock farm products, (3) to analyze the relationship between gross sales of agricultural products and stock farm products and GRDP, and (4) to construct a model of RIS that fits particularly for rural areas. This study particularly accentuates that a specialized industry is more meaningful when it can raise GRDP, which eventually can give positive effect of RIS on regions.

• 산업공학
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• 제10권2호
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• pp.15-28
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• 1997

Knowledge acquisition has been a major bottleneck in building expert systems. To ease the problems arising in knowledge acquisition, analog concept learning systems(ACLS) has been used. In this paper, in order to avoid the overfitting problem and secure a good performance, we propose the revised ACLS, which pruning methods -cost complexity, reduced error, pessimistic pruning and production rule- are incorporated into and apply them to the credit evaluation for Korean companies. The performances of the revised ACLS are evaluated in light of the prediction accuracy. To check the effect of the training data sampling on the performance, experiments are conducted using the different proportion of the training data. Experimental results show that the revised ACLS of combining cost complexity pruning with reduced error pruning performs best among original ACLS and other methods.

• 전기학회논문지
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• 제56권10호
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• pp.1814-1819
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• 2007

A new active resonator using defected ground structure with islands (DGSI) is proposed. The proposed resonator is composed of the conventional microstrip line with DGSI and negative resistance of active devices. The negative resistance part is realized by field effect transistor (FET) series feedback circuits. The characteristic of the proposed resonator with DGSI is improved by combining the negative resistance part with the parallel microstrip line structure with islands, where the electric field is formed the most strongly. The measured improvement of the proposed active resonator with DGSI are 4.55dB and 0.32dB in S21 and S22, respectively, at the resonant frequency whorl it is compared to the existing passive resonator having DGSI only.

• 한국경영과학회지
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• 제38권1호
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• pp.45-59
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• 2013

A long-term forecasting method for a new product in early stage of diffusion is proposed. The method includes a constrained non-linear least square estimation with the logistic diffusion model. The constraints would be critical market informations such as market potential, peak point, and take-off. Findings on 20 cases having almost full life cycle are that (i) combining any market information improves the forecasting accuracy, (ii) market potential is the most stable information, and (iii) peak point and take-off information have negative effect in case of overestimation.