• Journal of the Korean Society for Railway
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• v.15 no.6
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• pp.558-565
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• 2012

Abnormal climate or weather is more frequently reported nowadays due to the global climate change. Especially, extremely low temperature in winter season may cause bad thermal discomfort of passengers. In this study, the effect of car heating modes on cabin temperature change and distribution was studied by using a real-scale environmental chamber for passenger cabin. It was found that the cabin temperature rose quickly at the initial stage of heating system operation, but it stopped increasing after certain point. And, temperature was higher when the height from the floor was higher. Based on the obtained result, the way to minimize the decrease of passengers' thermal comfort was suggested.

• Journal of the Korean Institute of Gas
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• v.16 no.6
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• pp.17-22
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• 2012

In this study, characteristics of reforming process of Automotive LPG fuel using plasma reactor are investigated. Because plasma reformer technology has advantages of a fast start-up and wide fuel/oxidizer ratio of operation, and reactor size is smaller and more simple compared to typical combustor and catalytic reactor, plasma reforming is suitable to the on-board vehicle reformer. To evaluate the characteristics of the reforming process, parametric effect of $O_2$/C ratio, reactant flow rate and plasma power on the process were investigated. In the test of varying $O_2$/C ratio from partial oxidation stoichiometry to combustion stoichiometry, conversion of LPG was increased but selectivity of $H_2$ decreased. The optimum condition of $O_2$/C ratio for the highest $H_2$ yield was determined to be 0.8~0.9 for 20~50 lpm. The result can be a guide to map optimal condition of reforming process.

• Journal of Korean Society for Atmospheric Environment
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• v.23 no.3
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• pp.277-285
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• 2007

Porous cordierite beads, of which the average pore size was $130{\mu}m$ and porosity was about 80%, were prepared by the foaming method and then their application as support of the $Pt/{\gamma}-alumina$ catalyst for $NO_x$, reduction with propene was investigated. The pressure drop of a 2 mm porous beads filter was less than that of a 1 mm porous beads filter and the difference in pressure drop between these two increased as the flow rate increased. The catalytic activity of $Pt/{\gamma}-alumina$ washcoated on the porous bead was tested with varying Pt loading $(0.005{\sim}0.1g/cm^3),\;C_3H_6/NO$ mole ratio $(0.5{\sim}8)$, space velocity $(20,000{\sim}30,000h^{-1})$ and oxygen contents (1 and 8). Pt loading of $0.04g/cm^3$ showed the highest activity for $NO_x$ conversion. The $De-NO_x$, test was operated in the temperature range of $200{\sim}400^{\circ}C$ and the best operation temperature of the catalytic filter is about $250^{\circ}C$. As the C/N ratio increased, increase of the $NO_x$, conversion might result from the increase in exhaustion of the amount of oxygen by the reduction of hydrocarbon. $NO_x$ conversion at $20,000h^{-1}$ of space velocity shows a maximum 34% higher conversion than that at $30,000h^{-1}$. On condition that $O_2$ was 5%, space velocity was $20,000h^{-1}$ and the C/N ratio was 8, the $NO_x$ conversion exhibited a maximum of 40% at $250^{\circ}C$.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.37 no.2
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• pp.241-248
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• 2013

In this study, bearings were developed for a high-power propulsion motor operating in inclined operation conditions through a simulation and similitude-experimental methods using commercial rotating machinery dynamics analysis software. The developed journal bearing is electrically insulated and has low thermal conductivity because each part is connected with 2-4 -mm-thick epoxy plates. To realize an appropriate oil thickness, an oil lift system is adopted, and a half separated structure is applied to ensure the feasibility of maintaining very heavy components. This study discusses some of the key design aspects of sleeve bearing design for high-torque and low-speed propulsion motor applications. Furthermore, the conditions of variable slope tests are examined to prevent oil leakage from the bearing lip seal on the test rig.

• 제어로봇시스템학회:학술대회논문집
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• 2003.10a
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• pp.2451-2456
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• 2003

In biological cell manipulation, manual thrust or penetration of an injection pipette into an egg is currently performed by a skilled operator, relying only on visual feedback information. Massive load of various micro injection of either genes, fluid or cells in the postgenomic era calls a more reliable and automatic micro injection system that can test hundreds of genes or cell types at a single experiment. We initiated to study cellular force sensing in zebrafish eggs as the first step for the development of a more controllable micro injection system by any inexperienced operator. Zebrafish eggs at different developmental stages were collected and an integrated biomanipulation system was employed to measure cellular force during penetrating the egg envelope, the chorion. First of all, the biomanipulation system integrated with cellular force sensing instrument is implemented to measure the penetration force of cell membranes and characterize mechanical properties of zebrafish embryo cells. Furthermore, implementation of cellular force sensing system and calibration are presented. Finally, the cellular force sensing of penetrating cell membranes at each developmental stages was experimentally performed. The results demonstrated that the biomanipulation system with force sensing capability can measure cellular force at real-time while the injection operation is undergoing. The magnitude of the measured force was in the range of several hundreds of uN. The precise real-time measurement should provide the first step forwards for the development of an automatic and reliable injection system of various materials into biological cells.

• Journal of Institute of Control, Robotics and Systems
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• v.17 no.1
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• pp.47-53
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• 2011

To enable the efficient operation of ITS, it is necessary to collect location data for vehicles on the road. In the case of futuristic transportation systems like ubiquitous transportation and smart highway, a method of data collection that is advanced enough to incorporate road lane recognition is required. To meet this requirement, technology based on radio frequency identification (RFID) has been researched. However, RFID may fail to yield accurate location information during high-speed driving because of the time required for communication between the tag and the reader. Moreover, installing tags across all roads necessarily incurs an enormous cost. One cost-saving alternative currently being researched is to utilize GNSS (global navigation satellite system) carrierbased location information where available. For lane recognition using GNSS, a precise digital map for determining vehicle position by lane is needed in addition to the carrier-based GNSS location data. A "precise digital map" is a map containing the location information of each road lane to enable lane recognition. At present, precise digital maps are being created for lane recognition experiments by measuring the lanes in the test area. However, such work is being carried out through comparison with vehicle driving information, without definitions being established for detailed performance specifications. Therefore, this study analyzes the performance requirements of a precise digital map capable of lane recognition based on the accuracy of GNSS location information and the accuracy of the precise digital map. To analyze the performance of the precise digital map, simulations are carried out. The results show that to have high performance of this system, we need under 0.5m accuracy of the precise digital map.

• Journal of Astronomy and Space Sciences
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• v.37 no.2
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• pp.143-156
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• 2020

Korea Polar Research Institute (KOPRI) installed an ionospheric sounding radar system called Vertical Incidence Pulsed Ionospheric Radar (VIPIR) at Jang Bogo Station (JBS) in 2015 in order to routinely monitor the state of the ionosphere in the auroral oval and polar cap regions. Since 2017, after two-year test operation, it has been continuously operated to produce various ionospheric parameters. In this article, we will introduce the characteristics of the JBS-VIPIR observations and possible applications of the data for the study on the polar ionosphere. The JBS-VIPIR utilizes a log periodic transmit antenna that transmits 0.5-25 MHz radio waves, and a receiving array of 8 dipole antennas. It is operated in the Dynasonde B-mode pulse scheme and utilizes the 3-D inversion program, called NeXtYZ, for the data acquisition and processing, instead of the conventional 1-D inversion procedure as used in the most of digisonde observations. The JBS-VIPIR outputs include the height profiles of the electron density, ionospheric tilts, and ion drifts with a 2-minute temporal resolution in the bottomside ionosphere. With these observations, possible research applications will be briefly described in combination with other observations for the aurora, the neutral atmosphere and the magnetosphere simultaneously conducted at JBS.

• Journal of the Korean Society of Safety
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• v.35 no.3
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• pp.58-63
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• 2020

At the construction site of the driving site, the pile rebound and penetration measurements are performed manually to determine the end point of the driving operation, thereby causing the measurer to be exposed to a death accident. In this study, in order to eliminate the risk of this work, a non-contact penetration measuring device was developed and usability evaluation was conducted. The penetration measuring device is manufactured based on the ultrasonic sensor, and can be combined with the pile to deliver the data in real time, and the delivered data can be output in real time on the portable PC and the final penetration can be calculated. Usability evaluation on the device was conducted by comparison with manual work. Usability evaluation was largely evaluated on measured values, subjective comfort, and body parts comfort. The result of the measured value tended to overestimate the value measured manually by the measuring device, which is similar to the previous research. In terms of subjective comfort and body part comfort, overall satisfaction was higher than the manual method when using the measuring device. Taken together, these results indicate that it is possible to use the rudder measuring device in place of manual work in the construction site, and it is judged that the worker's comfort is greatly increased by using the measuring machine. The results of this study suggest that the use of non-contact measuring device in the field can be used as basic data to support them.

• Journal of the Korean Dietetic Association
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• v.7 no.1
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• pp.65-71
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• 2001

The purpose of this study was to produce proper nutrition and foodservice through positive intervention for diet-refusal patients who has difficulties in adaptation to hospital diet, and to contribute to hospital management with the focus of fast recovery. The survey was conducted using questionnaires between July 18 and August 17, 2000. The subjects were consisted of 24 diet-refusal patients who were hospitalized in St. Mary's Hospital except the patients hospitalized for the purpose of operation or pre-therapy tests. Also chart reviews were conducted. The statistical analysis of data was done by SAS/win 6.11 package to determine descriptive analysis and paired t-test and Pearson's correlation. The summary of study results is as follows : 1. Most of the subjects was receiving chemotherapy. The leading place for offering private food was from patient's home. Subjects worried about delayed recovery from illness due to nutritional problems caused by extreme fasting. The problems were in order of anorexia, nausea and vomiting during therapy process. 52.4% of subjects ate hospital diet after positive intervention. 2. Major reasons of hospital diet-refusal patients' dissatisfaction were in order of expenses, dissatisfaction, serum total protein levels were significantly lower(p<.05). 3. Serum Alb(p<.05), Hb(p<.05), Hct(p<.05) and TLC(p<.001) levels showed significantly negative correlations with fasting duration. With these results, it is concluded that a major cause of malnutrition among patients is to last fasting.

• Journal of Digital Convergence
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• v.13 no.8
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• pp.301-313
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• 2015

Robot technology has become a crucial part of today's business operation. In fact, more manufacturing firms have been utilizing robot technology in order to increase operational efficiency and productivity. Thus, this study develops the research model investigating firms; behavior for process innovation with intelligent robot. Three categories - Technical, Entrepreneur, and Environmental characteristic - are proposed in the research model as determinants of process innovation. These three characteristics include six variables(Perceived Direct Usefulness, Perceived Indirect Usefulness, Innovation, Risk Senstivity, Perceived Industry Pressure, and Perceived Government Pressure) as influencing factors on process innovation. The data from 77 employee at manufacturing firms were analyzed to test proposed hypotheses. The results reveal that all variables with exception of Perceived Government Pressure have a significant influence on process innovation. Based on the study results, theoretical and practical implications for process innovation with intelligent robot technology are discussed.