• Journal of the Korean Society of Safety
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• v.23 no.5
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• pp.7-14
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• 2008

The temperature distribution in a surface of diesel particulate filter(DPF) was measured using an infrared temperature camera. In order to regenerate the DPF, five partitioned electric heaters were used for heating the ceramic filter. The five partitioned heaters were switched on/off with some time interval one the other. The surface temperature distribution in the ceramic filter and electric heaters were measured with varying both the electrical power supply to the heaters and the mass flow rate of the air supply from a blower. The higher mass flow rate in the DPF system enhanced the uniformity in the surface temperature distribution of the ceramic filter due to effective convection heat transfer. The flow in the monolith ceramic structure of the DPF move mainly in the axial direction, which could be identified from the surface temperature of the ceramic filter.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.29 no.11
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• pp.66-73
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• 2015

AC-based power systems, having the advantages that voltage transformation and long distance transmission are easy, have been constructed since the last 19th century. However, DC-based power system is paid attention these days because of the development of power electronic devices as well as the increase of digital loads and distributed generation. For instance, the transmission systems using High Voltage DC (HVDC) are commercially operated in the world and the researches on distribution system using Low Voltage DC (LVDC) are gradually increased. This paper analyzes voltage sag, resulted from faults, in LVDC distribution system according to the number of poles. Modeling and simulation with various conditions are conducted by using ElectroMagnetic Transients Program (EMTP). Moreover, some countermeasures to reduce voltage sag in LVDC distribution system are suggested briefly.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.8 no.5
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• pp.1034-1041
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• 2007

This paper presents the developing results of improved distribution automation system including system configuration and subsystem design, prototype hardware and software implementation, and pilot tests on the real distribution networks of Korea Electric Power Corporation (KEPCO). An integrated system is designed to combine independent system for the distribution field works with DAS; transformer monitoring, power quality monitoring, voltage monitoring, outage monitoring, etc. The communication network is hierarchically configured as main network and branch network and well-defined integrated terminal units were developed. In addition, useful host configuration and applications were developed to integrate the services with DAS or interfacing other systems. Pilot tests were performed to verify that the system enables to properly integrate the DAS and other services of the distribution network.

• Journal of Korean Society of Water and Wastewater
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• v.20 no.2
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• pp.295-302
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• 2006

Over the past decades, a flocculation and/or sedimentation process have been adopted to remove pollutants from CSOs. It has been learned that major factors affecting settlement of pollutants are the particle size distribution, their settling velocities and their specific gravity. It is, therefore, a good idea to analyze the particle size distribution and settleability of CSOs pollutants in order to develop details in designing a process. Discussed in this study are pollutant characteristics of CSOs such as particle size distribution and settleability of pollutants. The power law function is applied and is found to be an effective and reliable index for expressing the particle size distribution of pollutants in CSOs. Based on the regression analysis it is observed that the derived constants of curves representing settling velocity profile are proportional to the initial concentration of particles and to the ${\beta}$-values of power law distributions.

• Korean Journal of Materials Research
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• v.16 no.10
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• pp.633-638
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• 2006

Silica powders with spherical shape and narrow size distribution were prepared by large-scale ultrasonic spray pyrolysis applying the droplet classification apparatus. On the other hand, silica powders prepared by large-scale ultrasonic spray pyrolysis without droplet classification apparatus had broad size distribution. Droplet classification apparatus used in this paper applied the principles of cyclone and dispersion plate with small holes. The droplets formed from the ultrasonic spray generator applying the droplet classification apparatus had narrow size distribution. The droplets with fine and large sizes were eliminated by droplet classification apparatus. The optimum flow rate of the carrier gas and diameter of the hole of the dispersion plate were studied to reduce the size distribution of the silica powders prepared by large-scale ultrasonic spray pyrolysis. The size distribution of the silica powders prepared by large-scale ultrasonic spray pyrolysis at the optimum preparation conditions was 0.76.

• Korean Journal of Ecology and Environment
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• v.37 no.3 s.108
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• pp.297-303
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• 2004

Two dimensional cellular automaton (CA) models were developed to investigate growth of biofilms in aquatic ecosystems. Simple local rules on CA were applied to governing growth of bacterial populations in relation to different nutrient concentrations. Initial bacterial distribution played an important role in determining population size and morphology of biofilm at low concentrations of nutrition. With clumped distribution, population size increased slowly compared with uniform and random distributions, while the porosity tented to be higher with uniform distribution compared with other initial distributions.

• Journal of Advanced Navigation Technology
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• v.14 no.6
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• pp.951-969
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• 2010

A Study on the Management Performance of the Distribution channel's CRM : Balanced Scorecard Approach as to CRM application field of the Distribution Company About Korea Airport Service In this paper, the performances of Distribution channel's estimation schemes for CRM system are investigated. We anticipate these moves will have a positive effect on the CRM Scorecard infra, process, elevate royalty environments. As is study of used SPSSWN 15.0 correlation analysis, regression analysis & AMOS 7.

• Journal of the Korean Applied Science and Technology
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• v.31 no.3
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• pp.402-407
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• 2014

Herein, we describe the effect of the cooling-off condition of a solution-processed 6,13-bis(triisopropylsilylethynyl)-pentacene (TIPS-pentacene) film on its molecular distribution and the resultant electrical properties. Since the solvent in a TIPS-pentacene droplet gradually evaporates from the rim to the center exhibiting a radial form of solute, for a quenched case, domains of the TIPS-pentacene film are aboriginally spread showing original features of radial shape due to suppressed molecular rearrangement during the momentary cooling period. For the slowly cooled case, however, TIPS-pentacene molecules are randomly rearranged during the long cooling period. As a result, in the lopsided electrodes structure proposed in this work, the charge transport generates more effectively under the case for radial distribution induced by the quenching technique. It was found that the molecular redistribution during the cooling-period plays an important role on the magnitude of the mobility in a solution-processed organic transistor. This work provides at least a scientific basis between the molecular distribution and electrical properties in solution-processed organic devices.

• The Journal of Industrial Distribution & Business
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• v.4 no.2
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• pp.31-40
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• 2013

Purpose - This study attempted to identify the value promotion clues that may operate as a consumer's motive, by shedding new light on consumer value and by reconstructing each variable analyzed through the means-end chain (MEC) theory. Research design, data, and methodology - In this study, 202 copies of effective questionnaires using the data of Yang and Ju (2012) were subjected to correlation, regression, and SEM. Results - All store selection attributes were verified as having a positive influence on the relationship quality. Although the store selection attributes were verified as exerting a positive influence on the relationship quality, according to the verification result of the mediating effect, consumer value was verified to be influenced only by the relationship quality instead of by the store selection attributes. Conclusion - As a result of path analysis on the proposed model after modification, it was verified that only product factor had a statistically significant positive influence and that social value was completely mediating between relationship quality and emotional value. It may be highlighted that the MEC theory concept would be applicable to the cause-and-effect relationship model.

• The Journal of Industrial Distribution & Business
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• v.4 no.2
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• pp.41-49
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• 2013

Purpose - Currently, the distribution environment has been changing rapidly because of the advent of super-supermarkets (SSM),which adopt the "price break" and "lowest price" strategies. Specifically, a diversification of the distribution environment allowed customers to reasonably decide where to shop. With a broadened range of criteria governing the choice of a store, determining changes in the distribution environment should be based on customer satisfaction surrounding the service levels of SSMs. This study examines the effects of service quality and product quality of SSMs on customer satisfaction levels, and analyzes whether these factors affect customers' revisit intention directly. Research design and methodology - A survey method was used and 127 SSM customers responded to the questionnaires that were developed to measure service quality, product quality, customer satisfaction, and store revisit intention. A multi-regression analysis was used to test the hypotheses. Results - Except hypothesis 2, the other seven hypotheses were supported. Hypothesis 2 suggested a positive relationship between product factors and customer satisfaction. Conclusions - This study found a systematic effect of service factors and product factors on customer satisfaction and word-of-mouth, and consequently on store revisit intention.