• Solar Energy
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• v.19 no.4
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• pp.11-20
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• 1999

The study on ice thermal storage system is to improve total system performance and increase the economical efficiency in actual air-conditioning facilities. To obtain the high charging and discharging efficiencies in ice thermal storage system, the improvement of thermal stratification is essential, therefore the process flow must be piston flow in the cylindrical type. In the influence of the inlet port type, the inflowing water in the distributor type diffuses through the whole storage tank more than in the slot type. In case of the flow process in the ice storage tank, the upward flow type in the charging process and the downward flow type in the discharging process make the stratification well, thereby the loss of energy wored be smaller. The influence of the inlet temperature difference and the change of the inlet flow rate is intensive when the temperature difference is larger, the flow rate is smaller in case of charging and the results are opposite in case of discharging with the reason that the good coduction condition. The total effeciency of the ice thermal storge system is 73% on condition that the porosity in the thermal storage tank is 0.55. This result shows that cylinderical ice storage tank has better storage capacity than rectangular type in case of the same porosity.

• Environmental Engineering Research
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• v.19 no.2
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• pp.151-155
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• 2014

This study compares the effects of flow on oil and suspended solids removal efficiencies in circular enhanced gravity plate separator equipped with coalescence medium. Coalescence medium acts to capture rising oil droplets and settling solid particles and assist in the coalescence of oil and coagulation of solid. The circular separator uses an upflow center-feed perforated-pipe distributor as the inlet. The co-current flow is achieved using 4 increasing sizes of frustum, whereas cross flow uses inclined coalescence plates running along the radius of the separator. The different arrangement gave the cross flow separator a higher coalescence plan area per operational volume, minimal and constant travelling distance for the oil droplets and particles, lower retention time, and higher operational flowrate. The cross flow separator exhibited 6.04% and 13.16% higher oil and total suspended solids removal efficiencies as compared to co-current flow.

• KIEAE Journal
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• v.7 no.5
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• pp.81-86
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• 2007

The research analyzes the arrangement of boiler and hot water header, the method of radiator pipe setting, hot water supply control, hourly heating situation of each room for underfloor radiant heating systems in Korea and suggests an alternative to improve to efficient heating method. One of the best options for install position of hot water distributor is under kitchen sink which is center point of all rooms, according to previous research of the energy saving strategies. When the radiator pipes are arranged to each individual room instead of bedrooms through livingroom and kitchen, it has energy saving effects. For rooms without occupancy according to a time period, hot water supply method should be intermittent heating rather than continuous heating. For this intermittent heating method, individual control of hot water supply is more practical, and it can lead to massive energy savings. The intermittent heating system has time-lag, so it is more effective in energy saving with mild and comfort condition if the spaces are preheated by automatic control equipment prior to required time.

• Annual Conference of KIPS
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• 2015.10a
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• pp.332-334
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• 2015

Nowadays a disaster event such as a building on fire, an earthquake or typhoon could occur any time, and any where. In such event, a warning notification system is a vital tool to send warning notifications to at-risk people in advance and provide them useful information to escape the dangerous area. Though some systems have been proposed such as emergency alert system using android, SMS or P2P overlay network, these works mainly focus on a reliable message distribution methods. In this work, we introduce a full prototype implementation of a personalized warning notification system based on geosocial information, which generates a personalized warning message for each user and delivers the messages through email or an android application. The system consists of four main modules: a web interface, database, a knowledge-based message generator, and message distributor. An android application is also created for user to receive warning messages on their smart phone. The prototype has been demonstrated successfully with a building-on-fire scenario.

• Korean Journal of Remote Sensing
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• v.24 no.5
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• pp.397-408
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• 2008

A wide variety of applications of imaging spectrometer have been proved using data from airborne systems. The Compact Airborne Imaging Spectrometer System (CAISS) was jointly designed and developed as the airborne hyperspectral imaging system by Korea Aerospace Research Institute (KARI) and ELOP inc., Israel. The primary mission of the CAISS is to acquire and provide full contiguous spectral information with high spatial resolution for advanced applications in the field of remote sensing. The CAISS consists of six physical units; the camera system, the gyro-stabilized mount, the jig, the GPS/INS, the power inverter and distributor, and the operating system. These subsystems are to be tested and verified in the laboratory before the flight. Especially the camera system of the CAISS has to be calibrated and validated with the calibration equipments such as the integrating sphere and spectral lamps. To improve data quality and its availability, it is the most important to understand the mechanism of imaging spectrometer system and the radiometric and spectral characteristics. The several performance tests of the CAISS were conducted in the camera system level. This paper presents the major characteristics of the CAISS, and summarizes the results of performance tests in the camera system level.

• Journal of Hydrogen and New Energy
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• v.32 no.5
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• pp.331-339
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• 2021

This study presents a novel way to enhance uniformity of the gas flow inside the solid oxide fuel cell (SOFC), which is critically important to fuel cell performance, by using dimples. A pattern of dimple, which works as a flow distributor/collector, is designed at the inlet and outlet section of a straight channel gas separator. Size of the dimples and the gap between them were changed to optimize the flow uniformity, and any change in size or gap is considered as one design. The results show that some dimple patterns significantly enhance the uniformity compared to baseline, about 4%, while the others slightly reduce it, about 1%. Besides, the dimple pattern also affects to the pressure drop in the flow channel, however the pressure drop in all cases are negligible (less than 26.4 Pa).

• KOREAN JOURNAL OF PACKAGING SCIENCE & TECHNOLOGY
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• v.26 no.3
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• pp.155-163
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• 2020

This paper conducted a study on the operation plan of the packaging system to enhance the logistics efficiency between the manufacturer and the distributor, whose prior research in the relevant field was insignificant. By identifying problems and improvements in the operation of the packaging system between domestic manufacturers and distributors through the Retail Ready Packaging. The institutional aspects were investigated to confirm that the mediation role of government and social organizations was required to resolve issues (χ2 = 148.916, p < 0.001), and that guidelines that gathered diverse opinions for the rational operation of the packaging system were essential, while institutional aspects are needed to be supplemented to be willing to improve logistics efficiency (χ2 = 95.781, p < 0.001). In this study, even though the difference in perception between manufacturers and distributors is clear and the issue related to the operation of the packaging system is ongoing, if there is no effort to grasp the issue, the opinions between manufacturers and distributors will be left at odds and could become a social problem. Unnecessary interference from government and social organizations should be excluded, but the level of mediation to support win-win management in order to promote logistics standardization and reduce CO2 and national logistics costs can be explained as a catalyst for improving logistics efficiency through reasonable operation of the packaging system.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.42 no.3
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• pp.15-24
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• 2019

Fair Allocation of profits or costs arising from joint participation by multiple individuals or entities with different purposes is essential for their continuing involvement and for their dissatisfaction reduction. In this research, fair allocation of the profits of forming a grand coalition in Three-Echelon Supply Chain (TESC) game that is composed of manufacturer, distributor and retailer, is studied. In particular, the solutions of the proportional method of profit, the proportional method of marginal profit, and Shapley value based on cooperative game theory are proved to be in the desirable characteristics of the core. The proportional method of profit and the proportional method of marginal profit are often used because of their ease of application. These methods distribute total profit in proportion to profits or marginal profits of each game participant. In addition, Shapley value can be defined as the average marginal profit when one game player is added at a time. Even though the calculation of the average of all possible marginal profits is not simple, Shapley value are often used as a useful method. Experiments have shown that the solution of the incremental method, which calculates the marginal cost of adding game players in the order of manufacturers, distributors and retailers, does not exist in the core.

• Journal of Industrial Convergence
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• v.15 no.2
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• pp.37-43
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• 2017

As the number of SSM(Super Supermarket) has been growing, the conflict between large companies and small-to-medium retailers is being deeper in which large-sized market has been growing rapidly and small to medium retailers has been depressed. To solve the conflict, the government enacted the system of business limiting of large enterprises by SMEs. It brought growth of sales of small-to-medium retailers. However, unintended effects were caused by the system. This research aims to analyze underlying structure beyond conflicts between SSM and small to medium retailers using system thinking and draw relationships between key factors. Thus we can provide political alternatives through simulation model which is developed based on the factors.

• Journal of Hydrogen and New Energy
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• v.31 no.6
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• pp.614-621
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• 2020

Recently, as the fine dust is increased and the emission regulations of diesel engines are strengthened, interest in diesel soot filtration devices is rapidly increased. In particular, there is a demand for technology development for higher efficiency of diesel exhaust gas after-treatment devices. As part of this, many studies conducted to increase the exhaust gas treatment efficiency by improving the flow uniformity of the exhaust gas in the DPF and reducing the pressure drop between the inlet and outlet of disel particle filter (DPF). In this study, computational fluid dynamics (CFD) simulation was performed when exhaust gas flows into the canning reduction device equipped with a 13" asymmetric DPF in order to maintain the flow uniformity in the diesel exhaust system and reduce the pressure. In particular, a study was conducted to find the geometry with the smallest pressure drop and the highest flow uniformity by simulating the DPF I/O ratio, exhaust gas temperature, inlet-outlet pressure and flow uniformity according to the geometry and hole size of distributor.