• Elastomers and Composites
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• v.27 no.1
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• pp.13-19
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• 1992

In this work, properties of ABS/AES blends were investigated. Blends were prepared by casting from THF. The thermal stability, light resistance, storage modulus and flame retardancy were measured by thermogravimetric analysis, cole. difference in Fade-o-meter, Rheovibron, and limiting oxygen index(LOI). The thermal stability, light resistance and storage modulus increased with increasing contents of AES. ABS and AES showed similar LOI. The LOI of the ABS/AES blends increased with rising contents of AES but all the blends were found to be flammable. It was observed that ABS and AES was incompatible from the morphology by scanning electron microscope(SEM).

• Proceedings of the IEEK Conference
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• 1998.06a
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• pp.863-866
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• 1998

In this paper two quick boosting charge pump circuits for high-speed EEPROM memory are proposed. In order to improve initial charge transfer efficiency, one uses weighted capacitors where each stage has different clock coupling capacitance, and the other uses a multi-path structure at the first stage. SPICE simulation results show that these charge pumps have improve drising-time characteristics, but their $V_{DD}$ mean currents are increased a little compared with conventioanl charge pumps. The rising time upt o 15V of the proposed charge pumps is 3 times faster than that of dickson's pump at the cost of 1.5 tiems more $V_{DD}$ mean current.rrent.

• Journal of Environmental Science International
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• v.11 no.8
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• pp.773-781
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• 2002

The natural carbon cycle has been perturbed since the mid-19th century by anthropogenic CO$_2$emissions from fossil fuel combustion and deforestation due to population growth and industrialization. The current study simulated the global carbon cycle for the past 42 years using an eight-box carbon cycle model. The results showed that since the terrestrial biospheric carbon sink was roughly offset by the deforestation source, the fossil fuel emission source was partitioned between the atmospheric and oceanic sinks. However, the partitioning ratio between the atmosphere and the ocean exhibited a change, that is, the carbon accumulation rate was faster in the atmosphere than in the ocean, due to a decrease in the so-called ocean buffering capacity. It was found that the ocean buffering capacity to take up excess CO$_2$decreased by 50% in terms of the buffer factor over the past 42 years. Accordingly, these results indicate that if the current CO$_2$emission trend continues, the future rate of increase in the atmospheric CO$_2$concentration will accelerate.

• Proceedings of the KSR Conference
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• 2007.05a
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• pp.1293-1296
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• 2007

An amenity requirement of the passenger using public traffic is rising continuously, and also The Ministry of Environment established "Indoor air quality management guidelines in public facilities(Dec. 2006)". To satisfy such requirement, the photoplasma device to decrease VOCs(Volatile Organic Compounds) and suspended bacillus is applied to the underframe mounted HVAC(Heating, Ventilating and Air-Conditioning) system for train. Air purifying method of photoplasma device is optical and chemical reaction that UV-light(wavelength less than 280nm) react with catalyst material(TiO2). To analyze the efficiency of photoplasma in this study, we measured the requirement time for toluene to decease down to 0.3ppm after contaminating the passenger cabin for train to toluene 1ppm.

• Korean Journal of Computational Design and Engineering
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• v.17 no.3
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• pp.164-174
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• 2012

The recent introduction of BIM technology has raised the interest on the BIM quality assurance and management more than ever. This study aims to consider the ways of BIM quality improvement by analyzing the most frequent issues rising from multiple BIM projects. For this purpose, the 12 test models from BIM education program hosted by buildingSMART Korea are investigated based on the requirements in the public BIM guidelines. All the BIM issues generated are categorized by the criteria applied and analyzed for each kind of building element. The results showed that more than half of the issued at least could be cleared out by improving modeling habits and technical guides.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2012.05a
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• pp.101-102
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• 2012

A policy for recycling waste concrete has been extensively studied, but it is still lacking to recycle and reuse as a cementitious powder, and the property has big different depending on the aggregate rates. In this study, the amount of cement powder according to the internal properties of the aggregate were mixed. From as a result, Concrete Powder to play inside the aggregate composition of the cement composition CaO rigs that causes loss of power and strength reduction due to rising real water cement ratio will affect large.

• 한국정보디스플레이학회:학술대회논문집
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• 2002.08a
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• pp.539-540
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• 2002

A self-discharge in multi-EEFLs and CCFLs has been found to provide a high luminance and efficiency. With a fast rising and falling times of $2{mu}s$, and the peak voltage over 1.6KV, the self-discharge occurs in EEFLs and CCFLs driven by a full bridge switching inverter. Particularly in CCFLs connected with a typical value of ballast capacitance, a self-discharge follows by the main discharge when the voltage falls to the ground.

• The Transactions of the Korean Institute of Electrical Engineers
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• v.32 no.5
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• pp.157-163
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• 1983

Positive and negative coronas in point-to-plane short gap have been investigated with the variations of point radius and gap length. Mainly the onset potentials and current pulses under various conditions were measured with a 70 MHz C.R.O. and a precise-controllable D.C. power supply. In the case of negative corona, the Trichel pulse corona, glow corona and spark regions were distinguished apparently and the critical gap lengths between them were also found clearly. In the case of positive corona, there are streamer corona, spark regions and the critical gap length between them, too. The current pulse forms of Trichel pulse corona of negative and streamer pulse corona of positive are similar in rising time, peak-to-peak time and pulse width. The glow corona current shows D.C. component in form.

• Journal of Biosystems Engineering
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• v.23 no.2
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• pp.187-194
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• 1998

This study was carried out to investigate mechanical properties o major part for agricultural machinery in Korea. The results are as follows ; 1. The mechanical Properties for heat resisting steel bars, alumium alloy castings, carbon steel for machine structural use, chromium molybdenum steels, high strength brass castings and carbon tool steels are proper for Korean standard. 2. The mechanical properties fir spring steels used to mould board, share of plow and blade of rotary are not suitable to Korean standard. Ⅰ think that a counterplan for quality rising is necessary such as supply of good quality materials and improvement of new materials in Korean agricultural machinery.

• Proceedings of the KIEE Conference
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• 2001.11b
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• pp.223-225
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• 2001

When a wide area blackout occurres, reenergizing transmission lines should be done at first. The KEPCO(Korea Electric Power Corporation) divides whole power system grid Into seven subsystem. This paper describes the investigation of facts, such as voltage rising and system stability, which occur in case that the blackstart plant of the Honam area will be displaced from Juam H/P to Seojingang H/P.