• Journal of Applied Reliability
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• v.14 no.1
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• pp.53-57
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• 2014

In the fields of reliability application, the most commonly used test methods for reliability demonstration are zero-failure acceptance tests since they require fewer test samples and less test time compared to other test methods that guarantee the same reliability with a given confidence level. For products with lognormal lifetime distribution, the value of scale parameter is usually assumed to be known in designing reliability demonstration tests. It is important to select correct values of scale parameters to guarantee the specified reliability with given confidence level exactly. The effect of using wrong values of scale parameters in designing reliability demonstration test for products with lognormal lifetime distribution is examined and selecting proper values of scale parameters for conservative reliability demonstration is discussed.

• Transactions of the Korean hydrogen and new energy society
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• v.35 no.1
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• pp.14-26
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• 2024

Global efforts continue with the goal of transition to a "carbon neutral (net zero)" society with zero carbon emissions by 2050. For this purpose, the technology of water electrolysis is being developed, which can store electricity generated from renewable energies in large quantities and over a long period of time as hydrogen. Recently, various research and large-scale projects on 'green hydrogen', which has no carbon emissions, are being conducted. In this paper, a comparison of water electrolysis technologies was carried out and, based on data provided by the International Energy Agency (IEA), large-scale water electrolysis demonstration projects were analyzed by classifying them by technology, power supply, country and end user. It is expected that through the analysis of large-scale water electrolysis demonstration projects, research directions and road maps can be provided for the development/implementation of commercial projects in the future.

• The Journal of Engineering Geology
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• v.28 no.2
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• pp.161-174
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• 2018

$CO_2$ storage site for small-scale demonstration has been investigated in Yeongil Bay, Pohang, SE Korea, using seismic survey and exploration well data. We found a potential storage formation consisting mainly of conglomerate and sandstone. The storage formation unconformably overlies volcanic basement rocks that are located in a depth from 650 to 950 m (below sea level). The depth of the storage formation is suitable for injecting supercritical $CO_2$ in the Pohang Basin. The average thickness of the storage formation is about 123 m, which possibly provides sufficient capacity at the level of small-scale storage demonstration. The overlying fine-grained deposits consist mainly of marine hemipelagic muds and interlayered turbidite sands. The overlying formation is considered as a good seal rock that is over 600 m thick and widely distributed in the onshore and offshore portions of the basin. NNE-trending faults found in the study area likely formed at basement level, probably not continue to seafloor. Such faults are interpreted as syndepositional faults involved to the basin initiation. This study reveals that the offshore area of the Pohang Basin contains deep geological formations suitable for small-scale $CO_2$ storage demonstration.

• 한국신재생에너지학회:학술대회논문집
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• 2008.05a
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• pp.479-482
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• 2008

Since late of 2000, KIER has developed a novel pyrolysis process for production of fuel oils from polymer wastes. It could have been possible due to large-scale funding of the Resource Recycling R&D Center. The target was to develop an uncatalyzed, continuous and automatic process producing oils that can be used as a fuel for small-scale industrial boilers. The process development has proceeded in three stages bench-scale unit, pilot plant and demonstration plant. As a result, the demonstration plant having capacity of 3,000 tons/year has been constructed and is currently under test operation for optimization of operation conditions. The process consisted of four parts ; feeding system, cracking reactor, refining system and others. Raw materials were pretreated via shredding and classifying to remove minerals, water, etc. There were 3 kind of products, oils(80%), gas(15%), carbonic residue(5%). The main products i.e. oils were gasoline and diesel. The calorific value of gas has been found to be about 18,000kcal/$m^3$ which is similar to petroleum gas and shows that it could be used as a process fuel. Key technologies adopted in the process are 1) Recirculation of feed for rapid melting and enhancement of fluidity for automatic control of system, 2) Tubular reactor specially-designed for heavy heat flux and prevention of coking, 3)Recirculation of heavy fraction for prevention of wax formation, and 4) continuous removal & re-reaction of sludge for high yield of main product (oil) and minimization of residue. The advantages of the process are full automation, continuous operation, no requirement of catalyst, minimization of coking and sludge problems, maximizing the product(fuel oil) yield and purity, low initial investment and operation costs and environment- friendly process. In this presentation, background of pyrolysis technology development, the details of KIER pyrolysis process flow, key technologies and the performances of the process will be discussed in detail.

• Journal of Applied Reliability
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• v.14 no.4
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• pp.220-224
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• 2014

A Bayesian zero-failure reliability demonstration test method for products with Weibull lifetime distribution is presented. Inverted gamma prior distribution for the scale parameter of the Weibull distribution is used to design the Bayesian test plan and selecting a prior distribution using a prior test information is discussed. A test procedure with zero-failure acceptance criterion is developed that guarantee specified reliability of a product with given confidence level. An example is provided to illustrate the use of the developed Bayesian reliability demonstration test method.

• Journal of the Korean Society of Combustion
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• v.16 no.2
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• pp.1-8
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• 2011

As one of the main technologies for carbon capture and storage in power generation, oxy-coal combustion is being developed for field demonstration in Korea. This study presents the results of numerical simulation for combustion in a single-wall-fired 100 $MW_e$-scale boiler proposed for the initial design of the demonstration plant. Using a commercial CFD code, the detailed combustion, flow and heat transfer characteristics were assessed both for air-mode and oxy-mode combustion. The results show that stable combustion can be achieved in the dual mode operation with the current boiler configuration. However, the differences in the flow pattern and heat transfer between the two combustion modes need to be considered in the design and operation which is mainly due to the larger density and specific heat of $CO_2$ compared to $N_2$. Further development of the boiler design is required using improved numerical modeling for radiative heat transfer and combustion.

• Journal of Mechanical Science and Technology
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• v.20 no.4
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• pp.554-560
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• 2006

This paper describes the demonstration of successful fabrication and initial characterization of micromachined pressure sensors and micromachined jets (microjets) fabricated for use in macro flow control and other applications. In this work, the microfabrication technology was investigated to create a micromachined fluidic control system with a goal of application in practical fluids problems, such as UAV (Unmanned Aerial Vehicle)-scale aerodynamic control. Approaches of this work include: (1) the development of suitable micromachined synthetic jets (microjets) as actuators, which obviate the need to physically extend micromachined structures into an external flow; and (2) a non-silicon alternative micromachining fabrication technology based on metallic substrates and lamination (in addition to traditional MEMS technologies) which will allow the realization of larger scale, more robust structures and larger array active areas for fluidic systems. As an initial study, an array of MEMS pressure sensors and an array of MEMS modulators for orifice-based control of microjets have been fabricated, and characterized. Both pressure sensors and modulators have been built using stainless steel as a substrate and a combination of lamination and traditional micromachining processes as fabrication technologies.

• Journal of Agricultural Extension & Community Development
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• v.5 no.1
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• pp.79-91
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• 1998

This study investigated and summarized the history of peasant movement which had been done by various peasant associations Yesan, Hongsong, and Tangjin from the beginning of Korean Catholic Peasant Movement from 1970 to 1995. First of all, we classified all the peasant movements(Yesan ; 120 times, Hongsong; 113 times and Tangjin; 107 times / total; 340 times) into 5 categories composed of movement time, movement type, movement method, the number of participators, and the movement subjects(issues). The frequency of peasant movement from 1990 to 1995, occupied 65.6%, which shows that the peasant movement was the most active during the time. The frequency of movement type, were we could find out, self-dependence type(62.9%), resistance type(15.6%) and request type(21.5%). The active way like congregation, demonstration, sit-in, rice file up struggle occupied 28.8% and it got the first place in movement way. In the movement subject category, the construction of organizations and solidarity activity amounted to 37.8% and democratization item(the union democratization and the social democratization related peasant) covered 16.8%. The 98 times of peasant movement were done in the active ways such as congregation and demonstration. However we cannot find these active ways in 1970s. In 1980s, the frequency of each item (congregation, demonstration, publicity and propaganda) was 28 times. But in 1990s, the frequency of congregation, or demonstration was higher than the others. The number of participators in peasant movement increased during 1980s∼1990s. The movement of which participators were 100∼499 was 32 times in 1980s and 70 times in 1990s each time. Such large scale movement amounted to over 30%. Furthermore, the large scale movement in which over 500 people participated amounted to 12 times in 1990s.

• Proceedings of the Korean Radioactive Waste Society Conference
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• 2004.02a
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• pp.191-204
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• 2004

The research and development of effective management technologies of the spent fuels discharged from power reactors are an important and essential task of KAERI. In resent several years KAERI has focused on a project named "development and demonstration of the Advanced spent fuel Conditioning Process (ACP) in a laboratory scale." The Facility for ACP demonstration consists of two Hot Cells and auxiliary facilities. It is now in the final design stage and will be constructed in 2004. After construction of the facility the ACP equipments will be installed in Hot Cells. The ACP will be demonstrated by some simulated spent fuels first and then by spent fuels.

• Proceedings of the Korea Society for Energy Engineering kosee Conference
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• 2004.05a
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• pp.109-114
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• 2004