• Convergence Security Journal
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• v.5 no.4
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• pp.41-48
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• 2005

Objective of this study is to design and implement security system based on intrusion tolerance technology for the improvement of dependability in defense system. In order to do so, I identify and extract core technologies through the research and analysis into characteristics, structures, main functions, and technologies of intrusion tolerance architecture. And I accomplish a design of security system through the redundant system based on these core technologies. To implement and verify intrusion tolerance system, I chose 'wargame system' as a subjected system, and accomplished 'Wargame Intrusion Tolerance System' and verified security required functions through a performance test. By applying showed security system into the development of application software based on intrusion tolerance, systematic and efficient system could be developed. Also applying 'WITDS' can solve the current security problems, and this will be basic model for design of security architecture in the federation system after.

• Korean Chemical Engineering Research
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• v.53 no.4
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• pp.496-502
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• 2015

Hydrocarbon dew point(HCDP), a property which is the most generally used for describing natural gas condensation, is a very important parameter of natural gas quality specifications. HCDP is strongly influenced by the concentration of the heavier hydrocarbon components, especially $C_6+$, so, along with compliance with gas quality specifications, build up of procedures for obtaining accurate HCDP is essential for gas transmission company, because hydrocarbon condensation present may cause serious operational and safety problems. This study has been carried out in an attempt to measure HCDP accurately by the automatic hydrocarbon dew point meter under the actual field conditions. Measured HCDP also has been compared with calculated HCDP using the composition determined by gas chromatograph and industry accepted equation of state at multiple pressures, along with the cricondentherm. The test results are 1) the automatic hydrocarbon dew point meter was able to measure stable HCDP continuously 2) the automatic hydrocarbon dew point meter has been performed reference measurement by pure propane with a known dew point from literature, and 3) A meaningful differences was observed when comparing the automatic hydrocarbon dew point meter and gas chromatograph results for synthetic standard gas mixtures and real gas mixtures.

• Clean Technology
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• v.20 no.4
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• pp.433-438
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• 2014

There is an increasing interest in the development of rechargeable batteries suitable for use in both hybrid electric vehicles and energy storage systems that require higher charge & discharge rates, bigger battery sizes and increased safety of the batteries. Spinel-type lithium titanium oxide ($Li_4Ti_5O_{12}$) as a potential anode for lithium ion batteries has many advantages. It is a zero-strain materials and it experiences no structural change during the charge/discharge precess. Thus, it has long cycle life due to its structural integrity. It also offers a stable operation voltage of approximately 1.55 V versus $Li^+/Li$, above the reduction potential of most organic electrolyte. In this study, Ru added $Li_4Ti_5O_{12}$ composites were synthesized by solid state process. The characteristics of active material were investigated with TGA-DTA, XRD, SEM and charge/discharge test. The capacity was reduced when Ru was added, however, the polarization decreased. The capacity rate of $Li_4Ti_5O_{12}$ with Ru (3%, 4%) addition was reduced during the charge/discharge precess with 10 C-rate as a high current density.

• Journal of Bio-Environment Control
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• v.27 no.3
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• pp.206-212
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• 2018

As many consumers prefer good quality food, farms have used various facilities to cultivate products for satisfying their desires. Among them, the most representative facilities are plastic and glass multi-span greenhouse. The height of both plastic greenhouse and glass greenhouse is around three meters high in Korea. As a result, the crop productivity is limited. The solution is to increase the height of the greenhouses to improve the greenhouses' environment. The device for raising columns consists of a stop device, a pneumatic cylinder, and a vertical member. Pneumatic cylinders were designed with a diameter of 160 mm and a stroke length of 50 mm, taking into consideration the safety factor of 1.5. In addition, the air flow was controlled by nozzle to achieve a time of less than 30 seconds per stroke. It was calculated that $21.5L{\cdot}min^{-1}$ of air was needed to complete in less than 30 seconds. Accordingly, the diameter of the nozzle is designed to be 0.5 mm. When the pressure was 0.9 MPa, the average raising force was 13,805N, which was close to the calculated value of 15,612N. The field test results show that any inconsistency in the row columns was not generated. and that it is considered applicable to the actual glass and plastic greenhouses.

• Composites Research
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• v.29 no.1
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• pp.40-44
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• 2016

Nuclear fuel cladding used in a nuclear power plant must possess superior oxidation resistance in the coolant atmosphere of high temperature/high pressure. However, as was the case for the critical LOCA (loss-of-coolant accident) accident that took place in the Fukushima disaster, there is a risk of hydrogen explosion when the nuclear fuel cladding and steam reacts dramatically to cause a rapid high-temperature oxidation accompanied by generation of a huge amount of hydrogen. Hence, an active search is ongoing for an alternative material to be used for manufacturing of nuclear fuel cladding. Studies are currently aimed at improving the safety of this cladding. In particular, ceramic-based nuclear fuel cladding, such as SiC, is receiving much attention due to the excellent radiation resistance, high strength, chemical durability against oxidation and corrosion, and excellent thermal conduction of ceramics. In the present study, cladding with $SiC_f/SiC$ protective films was fabricated using a process that forms a matrix phase by polymer impregnation of polycarbosilane (PCS) after filament-winding the SiC fiber onto an existing Zry-4 cladding tube. It is analyzed the oxidation and microstructure of the metal cladding with $SiC_f/SiC$ composite protective films using a drop tube furnace for thermal shock test.

• Steel and Composite Structures
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• v.34 no.1
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• pp.1-15
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• 2020

This paper presents experimental and numerical studies on effects of local damages on the in-plane elastic-plastic buckling and strength of a fixed parabolic steel tubular arch under a vertical load distributed uniformly over its span, which have not been reported in the literature hitherto. The in-plane structural behaviour and strength of ten specimens with different local damages are investigated experimentally. A finite element (FE) model for damaged steel tubular arches is established and is validated by the test results. The FE model is then used to conduct parametric studies on effects of the damage location, depth and length on the strength of steel arches. The experimental results and FE parametric studies show that effects of damages at the arch end on the strength of the arch are more significant than those of damages at other locations of the arch, and that effects of the damage depth on the strength of arches are most significant among those of the damage length. It is also found that the failure modes of a damaged steel tubular arch are much related to its initial geometric imperfections. The experimental results and extensive FE results show that when the effective cross-section considering local damages is used in calculating the modified slenderness of arches, the column bucking curve b in GB50017 or Eurocode3 can be used for assessing the remaining in-plane strength of locally damaged parabolic steel tubular arches under uniform compression. Furthermore, a useful interaction equation for assessing the remaining in-plane strength of damaged steel tubular arches that are subjected to the combined bending and axial compression is also proposed based on the validated FE models. It is shown that the proposed interaction equation can provide lower bound assessments for the remaining strength of damaged arches under in-plane general loading.

• Food Science and Preservation
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• v.18 no.4
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• pp.527-534
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• 2011

The purpose of this studies was analyzed moisture content, rheology and sensual test of jujube jungkwa by addition of water, sugar, fructose at processing of jujube jungkwa for development the optimization for processing of jujube jungkwa. The changes of moisture contents at process condition of jujube jungkwa were increased by increasing of sugar and water quantity. And moisture contents of jujube jungkwa were increased by high fructose quantity and low sugar quantity, but were decreased by high sugar and fructose quantity. The 'b' values of jujube jungkwa at low sugar quantity were decreased by the increasing of water quantity, but increased at high sugar quantity. The cohesiveness of jujube jungkwa at 0.03 kg of fructose were high by the increasing of sugar quantity, but those at 0.065 kg of fructose were high by the decreasing of sugar quantity. And those at 0.050 kg of fructose were similar without the quantity of sugar. The sweet taste of jujube jungkwa were increased by the increasing of water and fructose quantity. The characteristics of jungkwa at conditions of processing for the best quality of jujube jungkwa were 18-20% of moisture content, 2.0-3.0 of 'b' values, 3.0-3.2 of color scores, and 3.3-3.4 of sweet taste scores. The conditions of processing for the best quality of jujube jungkwa were determined to 0.95-1.04 L of water, 0.052-0.060 kg of fructose at 0.95 kg of sugar.

• Journal of Digital Convergence
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• v.16 no.7
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• pp.89-96
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• 2018

In this paper, we proposed a parametric estimation method for estimating H/W cost by using the development data of professional service robot in Korea. In addition, we derived the factors and weights that we can estimate the costs depending on the application environmental conditions of the robot. For the analysis, we developed the equation of professional service robot cost estimation using parametric method. We also derived the adjustment factors and following weights through FGI and Delphi for environmental conditions. We have developed a cost estimation equation that reflects the weight, volume, and manufacturing difficulty, and can derive a relational equation that reflects the environmental factors(dust/water, heat/cold, safety, test, technology innovation). This provides an objective basis for estimating the cost of professional service robots and will lead to ongoing research for estimating the H/W development cost of professional service robots. In the future, we will increase reliability by collecting abundant data, and will strengthen models through finding functional factors.

• Journal of Digital Convergence
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• v.18 no.4
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• pp.67-74
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• 2020

The purpose of this study has developed a teaching and learning informatization indicator that provides the basis for utilizing or disseminating the beneficial teaching and learning informatization environment promoted by each university. The research method analyzes various informatization indicators developed by KERIS from 2002 to 2015 and recent environment such as Edutech, future education report, teaching and learning field report, and reflects them in indicator development. The development of the third indicator was completed by dividing it into Input, Process, Output stages by reflecting expert opinions in the first and second indicators. As a result, the core words of the university's teaching-learning informatization infrastructure building, sharing of educational resources, open development and sharing, joint purchase of resources, information safety system and literacy education, current status grasping, and resource utilization were derived. In the future, I will fill out the questionnaire to supplement the question through a pilot test and to grasp the current status of teaching and learning informatization in the entire university.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.19 no.2
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• pp.89-103
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• 2020

As we face an aging society, the demand for personal mobility for disabled and aged people is increasing. In fact, as of 2017, the number of electric wheelchair in the country continues to increase to 90,000. However, people with disabilities and seniors are more likely to have accidents while driving, because their judgment and coordination are inferior to normal people. One of the causes of the accident is the interference of personal vehicle steering control due to unbalanced road surface conditions. In this paper, we introduce a encoder type semantic segmentation algorithm that can recognize road conditions at high speed to prevent such accidents. To this end, more than 1,500 training data and 150 test data including road surface damage were newly secured. With the data, we proposed a deep neural network composed of encoder stages, unlike the Auto-encoding type consisting of encoder and decoder stages. Compared to the conventional method, this deep neural network has a 4.45% increase in mean accuracy, a 59.2% decrease in parameters, and an 11.9% increase in computation speed. It is expected that safe personal transportation will be come soon by utilizing such high speed algorithm.