• Membrane Journal
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• v.33 no.6
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• pp.352-361
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• 2023

Steam methane reforming is currently the most widely used technology for producing hydrogen, a clean fuel. Hydrogen produced by steam methane reforming contains impurities such as carbon monoxide, and it is essential to undergo an appropriate post-purification step for commercial usage, such as fuel cells. Recently, membrane separation technology has been gaining great attention as an effective purification method; in this study, we evaluated the feasibility of using commercial polysulfone membranes for biogas upgrading to separate and recover hydrogen from a hydrogen/carbon monoxide gas mixture. Initially, we examined the physicochemical properties of the commercial membrane used. We then conducted performance evaluations of the commercial membrane module under various conditions using mixed gas, considering factors such as stage-cut and operating pressure. Finally, based on the evaluation results, we carried out simulations for process design. The maximum H₂ permeability and H₂/CO separation factor for the commercial membrane process were recorded at 361 GPU and 20.6, respectively. Additionally, the CO removal efficiency reached up to 94%, and the produced hydrogen concentration achieved a maximum of 99.1%.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 2010.04a
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• pp.173-174
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• 2010

As the quantity of goods transported, port industry and inland transport industry have developing to transport 630million ton goods annually. And the inland transport industry consists of ground transport for almost 80% of total transported goods. But, ground transport causes some serious problems especially the emission of greenhouse gases from trucks. According to issue "global warming", many regulations and agreements with countries in the world are becoming necessary and it is being fulfilled now. It is sure that Korea will have duty to reduce CO2 emission from 2013. Thus inland transport must cut off CO2 emission level. Therefore this paper will address that the calculation of CO2 emission under route of transportation container from six major container ports in Korea. And then, it will predict CO2 emission of inland transport industry according to increasing container traffic rate at ports.

• The Korean Journal of Quaternary Research
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• v.19 no.2
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• pp.50-54
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• 2005

Some basic summer precipitation features over East Asia during the $20^{th}-21^{st}$ century as simulated / projected by the 22 coupled climate models under the IPCC AR4 program are investigated. Keeping in view that these are climate runs without prescribed SSTs, models perform well in simulating the regional annual cycle, spatial patterns (not shown) and the inter-annual variability. The projections under the 1% increase in $CO_2$ compounded until reaching double and held constant thereafter reveal that (a) Precipitation is likely to increase in all the months in particular during the summer monsoon (JJA) months. (b) The mean summer monsoon rainfall can increase from 4.2 to 13.5% and its variability is also likely to increase in the warming world due to increase in $CO_2$ (c) Extreme excess and deficient seasonal monsoons are likely to become more intense (not shown here) (d) Once the increase in $CO_2$ is cut-off, the system will reach a state of equilibrium, and then the rate of increase in precipitation is also expected to remain constant.

• Journal of Fashion Business
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• v.10 no.6
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• pp.110-121
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• 2006

The purpose of this study is to analyze the various types and areas of recent collaborations in fashion industry and to find the utility value of collaboration. Seventy seven cases of fashion collaboration marketing strategies were selected from officially announced literature survey and enterprises information around the world. Among the seventy seven cases of fashion collaboration surveyed in this study, collaboration with other fields made up 59.7 percent, collaboration between the same fashion categories made up 40.3 percent. Among the areas of other fields, collaboration with IT(Information Technology) or Motor enterprises were included and made up 36.4 percent. Collaborations with Culture and art world that fashion brands collaborate with world-renowned industrial designer or artist and star entertainers were also included and made up 23.3 percent. Among the areas of the same categories, collaboration of fashion designer and sports or casual brand made up 22.1 percent. Collaborations of home shopping mall and fashion designer made up 18.2 percent. Collaboration cases surveyed in this study were classified according to three types; co-product development, co-branding, and co-marketing. Collaboration for co-product development made up 72.7 percent. Collaboration for co-branding made up 27.3 percent. Collaboration for co-marketing made up 37.7 percent. These collaboration marketing strategies are very efficient to upgrade brand image and cut the marketing cost by creating new target, product, brand, and promotion through successful partnerships. Therefore, much more various types and areas of fashion collaborations should be developed to create something new for future consumers.

• Journal of Biosystems Engineering
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• v.42 no.1
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• pp.12-22
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• 2017

Purpose: This aim of this study was to develop a pick-up type pulse crop harvester for harvesting cut and dried pulse crop. Methods: The pick-up type pulse crop harvester was designed and constructed. Its specifications and operating performance were investigated. Results: Compared with conventional bean harvesters, the pick-up type pulse crop harvester adopted seven rows of chains with tines to pick-up the cut and dried pulse crop on a flat or ridged field, two transverse threshing drums with steel wire teeth to reduce the threshing speed, and a tilt plate and plastic bucket elevator for conveying clean grain to reduce damage. The threshing speed and the oscillating frequency of the separating and cleaning parts according to crop type and condition could be varied easily to efficiently use engine power and to improve harvesting performance. The harvester showed forward speed ranges of 0 ~ 1.5 m/s during harvesting operation, and 0 ~ 2.5 m/s during road travelling. The pick-up width of the harvester was about 1 m. Conclusions: The pick-up type self-propelled 51.5 kW harvester was designed and constructed to harvest cut and dried pulse crop. The effective field capacity of the harvester was predicted as above 40 a/h.

• Journal of the Korean Society for Precision Engineering
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• v.29 no.6
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• pp.693-701
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• 2012

In this study, a small wind turbine airfoil specialized for national wind condition was designed in order to develop the furling control type HAWT. And then a flow analysis was carried out based on the blade drawing which was designed to characterize of the developed airfoil. The result of the flow analysis showed that the torque on the 3 blades was 180.23N.m. This is equivalent to an output power of 5.66kw and an output efficiency of 0.44. Then we produced and constructed a 3kW - furling control type HAWT by getting the system unit design technology such as the specialized furling control device. By operating this turbine, we could get 3kW of the rated power at a wind speed of 10.5m/s through the ability test. Cut-in wind speed was 2m/s, generator efficiency was 92% at the rated power output. Sound power level was 87.2dB(A). Also we observed that the output power was limited to 10.5m/s with furling system operation.

• Journal of Power System Engineering
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• v.21 no.6
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• pp.94-100
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• 2017

Due to the environmental problems caused by the greenhouse effect, regulation of $CO_2$ emissions is getting stronger day by day. In paricular, regulations of automobiles $CO_2$ emissions are being strengthen. However, existing $CO_2$ measurement methods do not reflect the environment and operating conditions on actual roads. Emissions of $CO_2$ can be increased by various conditions such as environmental condition(temperature and humidity) and driver's tendency(aggressive and passive). Therefore it is necessary to reflect the conditions of various actual roads such as 5-cycle test method on behalf of the existing $CO_2$ emission measurement method. The 5-cycle measurement method has five test modes; FTP-75, HWFET, US06, SC03, Cold FTP-75. The method reflects the following three environments and operating conditions as compared to conventional method; Using heater at low temperature, Aggressive driving such as rapid acceleration or deceleration, Using air conditioner at high temperature. Because of these various conditions of each test cycle, the 5-cycle method can reflect actual environments and operating conditions. This paper attempt to analyze $CO_2$ emission characteristics based on the results measured through the 5-cycle mode and develop the correction formula that can derive the results of the 5-cycle test method using existing test methods. As a result, the developed correction formula is expected to reduce $CO_2$ emissions and cut down expense for testing 5-cycle mode.

• Proceedings of the Korean Geotechical Society Conference
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• 2005.10a
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• pp.210-220
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• 2005

We have analyzed the stability for cut-slopes at main street 3-2 line section in Pa-ju local industrial complex. After studying an additional boring test, laboratory test and face mapping etc., we have determined the extent of reinforcement, slope inclinations and soil strength parameter from the analysis of test results. After changing the inclination of slopes for ground limit and carrying out the analysis of slope stability, we applied the Mass Nailing Method to the site because of need for reinforcement to soil and weathered rock slopes. In slope for soft and hard rock sections, we also reinforced the sections that are difficult to obtain the safety without reinforcement in alteration zone.

• Journal of Welding and Joining
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• v.13 no.4
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• pp.113-121
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• 1995

This study deals with the quality and the optimum range of laser cutting process. Cold rolled steel sheets for automobile application were cut by a high power CO$_{2}$ laser system with beam quality of TEM$_{\infty}$ mode. Both process parameters such as travel speed and assist gas pressure, and quality factors were considered to optimize the laser cutting. It was revealed that the thinner the sheet thickness, the less effect of oxidation energy for contributing the cutting process. High speed photographs demonstrated that molten spot on the cut surface moved in a random and vigorous manner according to its viscosity and the flowing direction of assist gas, which resulted in so called striation. Laser cutting produced a very smooth surface of average roughness(Ra) about less than 1.5.mu.m at the optimum range. It was also shown that the characteristics of dross formation was influenced by the flowing durection of assist gas and the fluidity of molten metal drop..

• Journal of Electrical Engineering and information Science
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• v.2 no.5
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• pp.129-133
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• 1997

A circuit model for a field emission triode has been proposed. The model parameters have been extracted from he fabricated silicon tip array and verified by comparing with the results simulated by circuit simulator(SPICE). The cut-off frequency can be calculated from the parametric capacitance and the transconductance values extracted from measurements. For the field emission triode, the capacitance of 3.45fF/tip and the transconductance of 0.94nS/tip have been measured under the emission current of 4.1nA/tip. From these values, the cut-off frequency is predicted to be 43 kHz but th measured one came out to be 6 kHz. because o the parasitic capacitance components.