• 한국태양에너지학회:학술대회논문집
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• 2008.11a
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• pp.214-219
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• 2008

This study is describes thermal performance of solar cooling and hot water for demonstration system with ETSC(Evacuated tubular solar collector) installed at Seo-gu culture center of Kwanju. Control condition for solar cooling and hot water system is changed by connection of auxiliary heater. Demonstration system was connected to central air conditioning system. Demonstration system was operated by two types. First type(A) was operated to cooling and hot water supply in that order. Second type(B) was operated to hot water supply and cooling in that order. As a result. it was indicated that the total solar energy consumption of (A) was 799 MJ and the solar energy consumption rate for the cooling and hot water supply was 70% and 30% respectively. Total solar energy consumption of (b) was 898 MJ and the solar energy consumption rate for the cooling and hot water supply was 31% and 69% respectively.

• Journal of Engineering Education Research
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• v.15 no.3
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• pp.3-11
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• 2012

This paper discusses the effect that classroom demonstrations have on students' conceptual understanding in concepts in introductory physics. We used the same conceptual survey to probe the students' understanding on certain concepts before and after taking the course. We introduce Hake's , which is used to evaluate the effect of various kind of teaching methods, suggested by physics education research groups, on conceptual understanding of students who took the class. The effect of physics class using demonstration turned to be better than the traditional lecture, higher for students who graduated from science schools with higher prior knowledge and demonstration experience. Authors suggest to use to probe concepts which need more attention.

• The Journal of Korean Association of Computer Education
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• v.16 no.3
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• pp.23-30
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• 2013

With proliferation of the internet, the internet ethics in contrast to existing ethics has been recognized as one of the disciplines. Internet ethics is one of liberal arts courses in a college as well as a class in elementary, middle and high schools. We also have taught this subject for a number of years. In order to effectively communicate to students the internet ethics course as computer scientists, we gave some demonstration practice lectures by taking advantage of internet ethics related videos. Since the latest UCC presentation and its discussion were performed, it was helpful for students to recognize the internet ethical issues and concerns. We confirmed that classroom students' concentration and understanding for internet ethics increases by a survey of the regular attendees. This research presented a lecture practice case model to teach comprehensive internet ethics topics to college students effectively.

• Korean Journal of Logic
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• v.12 no.2
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• pp.59-88
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• 2009

According to David Hume, a deductive demonstration for inductive inference is not possible, because inductive inference is not deductive; and an inductive demonstration for inductive inference is not possible either, because such a demonstration is circular. Thus, on his view, there is no way of justifying inductive inference. Ever since Hume raised this problem of induction, a fair number of philosophers have tried to solve it. Nevertheless there is still no solution which is plausible enough to receive wide endorsement. According to Wilfrid Sellars, we cannot justify inductive inference by any theoretical reasoning; we can vindicate it only by a certain sort of practical reasoning. In this paper, I defend this Sellarsian proposal by developing and explaining it.

• Proceedings of the Korea Information Processing Society Conference
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• 2005.11a
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• pp.713-716
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• 2005

차세대 원자로로 부각되고 있는 고온가스냉각 원자로에서는 고온 안정성 및 핵분열생성물 차단 성능이 우수한 TRISO(Tri-Isotropic) 핵연료를 사용하고 있다. TRISO 핵연료 입자는 직경이 약 1mm인 구 형태로 입자의 중심에는 직경 $0.35^{\sim}0.6\;{\mu}m$의 핵연료 입자가 포함되며 입자 외곽을 코팅 층이 에워 싸고 있다. 이 코팅층은 완충(buffer) PyC 층, 내부 PyC 층, 외부 PyC 층으로 구성되어 있다. 각 코팅 층의 두께를 수십$^{\sim}$백 ${\mu}m$ 범위이며 사양으로 정해져 있어 핵연료 입자 제조 후 사양을 만족하는지를 검사해야 한다. 본 연구에서는 TRISO 핵연료 입자 정보를 컴퓨터로 생성하고 가상의 X-선 래디오그래피 방법을 이용하여 투시 영상을 구성한 후 Filtered Backprojection 기법을 이용하여 단면 영상을 재구성하고 이 단면 영상을 이용하여 코팅 층의 두께를 정밀하게 측정하기 위한 모의 실험을 수행하였다. 경계선이 불명확한 투시영상이 아닌 경계선이 명확한 재구성 단면 영상을 이용하여 코팅 층의 두께를 약 2.3% 이내의 오차율로 정밀하게 측정하였다.

• Journal of the Korean Society of Combustion
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• v.20 no.1
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• pp.15-23
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• 2015

This paper presents the results of field demonstration for fuel switching to bio-fuel oil in 4 commercial heavy oil fired power plants. The 100% fuel switching field demonstration was successfully carried out in two tangential-firing boilers at a capacity of 75 and 100 MWe respectively without major equipment retrofit, and also 25% bio-fuel oil blending for two opposite firing boilers at a capacity of 350 and 400 MWe respectively. Despite the low density and heating value, the bio fuel was successfully replaced heavy fuel oil at the full load by only adjusting operational parameters. Incase of bio fuel oil combustion, heat absorption of radiative heat transfer section was reduced while convection section has opposite trend. In pollutants emission, a major reductionin SOx as well as 10-20% reduction in NOx were achieved by the fuels witching. On the other hand, boiler efficiency was slightly underestimated.

• Tunnel and Underground Space
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• v.24 no.1
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• pp.21-31
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• 2014

In order to generate electricity from geothermal energy for non-volcanic region, the concept of enhanced geothermal system (EGS) is introduced which forms an artificial reservoir by injecting high pressure fluid to 5 km deep and circulating geothermal fluid through the reservoir. Demonstration studies have been conducted in various countries and regions for determining the feasibility of EGS. In this technical note, experiences, errors, and implications of EGS demonstration projects in UK Rosemanowes and Australia Cooper Basin which have been carried out since 2002 are introduced to be used for the EGS demonstration project in Korea.

• Journal of Korean Society on Water Environment
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• v.36 no.1
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• pp.29-35
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• 2020

To manage the non-point source pollution and restore the water circulation, many technologies including infiltration or reservoir systems were installed in the urban area. These facilities have many problems regarding maintenance as their operation period becomes lengthier. The purpose of this study was to estimate the optimal maintenance timing through a long-term load test on the infiltration trench as one of the low impact development techniques. An infiltration trench was installed in the demonstration test facility, and stormwater was manufactured by Manual on installation and operation of non-point pollution management facilities from the Ministry of Environment, Korea and entered into the infiltration trench. Particle size distribution (PSD), suspended solids (SS) removal efficiency, and infiltration rate change tests were performed on inflow and outflow water. In case of the PSD, the maximum particulate size in the outflow decreased from 64 ㎛ to 33 ㎛ as the operating duration elapsed. The SS removal efficiency improved from 97 % to 99 %. The infiltration rate changed from 0.113 L/sec to 0.015 L/sec during the operation duration. The maintenance timing was determined based on the stormwater runoff requirements with these changes in water quality and infiltration rate. The methodologies in this study could be used to estimate the timing of maintenance of other low impact development techniques.

• Smart Media Journal
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• v.7 no.1
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• pp.24-30
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• 2018

Acquisition of the FIDO authentication technology in pursuit of improved security function of the NFC-based 2 factor electronic payment system enabled GenoTech Ch., Ltd. to develop its new service, Gallery-Auction, demoed at Daegu Exhibition. The demonstration was followed by the improvement requests in banner creation & installation, changes in UI, changes in order of operation, etc, which were taken into account for the succeeding update. During the second demonstration held at 'Art: Gwangju: 17,' it analyzed and visualized the number of visitors per hour there.

• Journal of the Korean Solar Energy Society
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• v.27 no.4
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• pp.35-41
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• 2007

To demonstrate the desalination system, the demo-plant was scheduled to be installed. The system was planned to use solar thermal collector as heat source and PV as electricity source. For the design of the desalination demonstration system, firstly the solar thermal system would be well designed from the result between the supplied heat into the fresh water generator and the fresh water yield. The generator for demonstration system was chosen as the fresh water generator of the single stage and effect with plate-type heat exchanger using low pressure evaporation method. The test facility for the tests to reveal the relationship between the fresh water yield and the supplied heat flow rate was designed and manufactured. The maximum fresh water yield of two fresh water generators applied in this study was designed as 1.5 Ton/day. The parameters relating with the performance of fresh water generator are known as sea water inlet temperature, hot water inlet temperature, and hot water flow rate. Through the experiments, this study firstly showed detail operation characteristics of the generator and designed the solar thermal system for the demonstration system.