• Journal of the Korea Institute of Building Construction
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• v.13 no.1
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• pp.38-47
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• 2013

When building with concrete in cold weather, an insulation method of heat curing must be determined, and a holistic curing plan that considers the characteristics of structures, the heat loss coefficient of a curing sheet, the joint condition of the curing materials and the quantity of heat produced by a heating apparatus is an essential prerequisite for protection against early frost damage. But on a number of national construction sites, there have been serious problems in cold weather concreting due to the unreliability of the information obtained from practical experience. In the construction field in Japan, there is a specification for heat curing prepared by Japanese Architectural Society, which provides an equation for calculating heat quantity. It is also necessary to adopt a detailed specification for a standard heat curing method that is applicable to all national construction sites. In this study, the effect of bubble sheets on the economic feasibility of cold weather concrete is investigated through a comparison with the blue sheets commonly prescribed in national construction sites. In conclusion, this study found that bubble sheets had the effect of reducing the cost of curing materials and the fuel cost consumed by a heating apparatus, compared to the use of blue sheets.

• Nuclear Engineering and Technology
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• v.46 no.5
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• pp.595-604
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• 2014

SILER (Seismic-Initiated event risk mitigation in LEad-cooled Reactors) is a Collaborative Project, partially funded by the European Commission in the $7^{th}$ Framework Programme, aimed at studying the risk associated to seismic-initiated events in Generation IV Heavy Liquid Metal reactors, and developing adequate protection measures. The project started in October 2011, and will run for a duration of three years. The attention of SILER is focused on the evaluation of the effects of earthquakes, with particular regards to beyond-design seismic events, and to the identification of mitigation strategies, acting both on structures and components design. Special efforts are devoted to the development of seismic isolation devices and related interface components. Two reference designs, at the state of development available at the beginning of the project and coming from the $6^{th}$ Framework Programme, have been considered: ELSY (European Lead Fast Reactor) for the Lead Fast Reactors (LFR), and MYRRHA (Multi-purpose hYbrid Research Reactor for High-tech Applications) for the Accelerator-Driven Systems (ADS). This paper describes the main activities and results obtained so far, paying particular attention to the development of seismic isolators, and the interface components which must be installed between the isolated reactor building and the non-isolated parts of the plant, such as the pipe expansion joints and the joint-cover of the seismic gap.

• Journal of Navigation and Port Research
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• v.30 no.7
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• pp.585-590
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• 2006

Though the issue on the integration of maritime transport market in Northeast Asia has a long history, there has never been any notable progress. Especially the lack of country-wise analysis on the barriers of market integration appears as a serious problem for more concrete discussion and the design of the roadmap for market integration. This study analyzes the maritime market of each country in the aspect of infrastructure provision, the development of the industry, change of institutions, and network connectivity and compare the competitiveness of 3 countries in the Northeast maritime market. Furthermore this study analyzes the barriers for market integration on the basis of bilateral relation, i.e. Korea-Japan, Korea-China and Japan-Korea. Based on these analyses, this study finds out the fact that the most serious barrier for market integration among 3 countries is the egocentric policies for the protection of industries in each country rather than any other institutional or physical barriers. In conclusion, this study argues that 3 countries should try to find out a third policy alternative which can make 3 countries enjoy the win-win game, such as route integration among 3 countries and joint venture for the liners operated in the region.

• The Journal of the Korea institute of electronic communication sciences
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• v.10 no.12
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• pp.1345-1354
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• 2015

This paper, information communication code standard($KS{\times}1001$, confirmation in 2004), as definded in Hangul Character Code Hangul AMI/HDB-3 the code set for the new system Hangul consonant and vowel tables presented. The result of the existing system and the code set ($4{\times}4$) bit source coding rules for comparing the frequency of use Hangul consonant and vowel tables(The National Institute of The Korea Language) and statistices showed that 44% of the data processing efficiency is improved.

• Steel and Composite Structures
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• v.43 no.5
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• pp.673-688
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• 2022

Post-earthquake fire is a major threat since most structures are designed allowing some damage during strong earthquakes, which will expose a more vulnerable structure to post-earthquake fire compared to an intact structure. A series of experimental research on steel-concrete composite beam-to-column joints subjected to fire after cyclic loading has been carried out and a clear reduction of fire resistance due to the partial damage caused by cyclic loading was observed. In this paper, by using ABAQUS a robust finite element model is developed for exploring the performance of steel-concrete composite joints in post-earthquake fire scenarios. After validation of these models with the previously conducted experimental results, a comprehensive numerical analysis is performed, allowing influential parameters affecting the post-earthquake fire behavior of the steel-concrete composite joints to be identified. Specifically, the level of pre-damage induced by cyclic loading is regraded to deteriorate mechanical and thermal properties of concrete, material properties of steel, and thickness of the fire protection layer. It is found that the ultimate temperature of the joint is affected by the load ratio while fire-resistant duration is relevant to the heating rate, both of which change due to the damage induced by the cyclic loading.

• Geomechanics and Engineering
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• v.8 no.6
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• pp.757-767
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• 2015

Rock mass is an important engineering material. In hydropower engineering, rock mass of bank slope controlled the stability of an arch dam. However, mechanical characteristics of the rock mass are not only affected by lithology, but also joints. On the basis of field geological survey, this paper built rock mass material containing parallel concentrated joints with different dip angle, different number under different stress conditions by PFC (Particle Flow Code) numerical simulation. Next, we analyzed mechanical property and fracture features of this rock mass. The following achievements have been obtained through this research. (1) When dip angle of joints is $15^{\circ}$ and $30^{\circ}$, with the increase of joints number, peak strength of rock mass has not changed much. But when dip angle increase to $45^{\circ}$, especially increase to $60^{\circ}$ and $75^{\circ}$, peak strength of rock mass decreased obviously with the increase of joints number. (2) With the increase of confining stress, peak strengths of all rock mass have different degree of improvement, especially the rock mass with dip angle of $75^{\circ}$. (3) Under the condition of no confining stress, dip angle of joints is low and joint number is small, existence of joints has little influence on fracture mode of rock mass, but when joints number increase to 5, tensile deformation firstly happened at joints zone and further resulted in tension fracture of the whole rock mass. When dip angle of joints increases to $45^{\circ}$, fracture presented as shear along joints, and with increase of joints number, strength of rock mass is weakened caused by shear-tension fracture zone along joints. When dip angle of joints increases to $60^{\circ}$ and $75^{\circ}$, deformation and fracture model presented as tension fracture zone along concentrated joints. (4) Influence of increase of confining stress on fracture modes is to weaken joints' control function and to reduce the width of fracture zone. Furthermore, increase of confining stress translated deformation mode from tension to shear.

• Herbal Formula Science
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• v.29 no.3
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• pp.127-145
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• 2021

Objectives : The purpose of this study was to evaluate the effects of Daeganghwal-tang on knee cartilage in monosodium iodoacetate(MIA)-induced osteoarthritis rats. Methods : Forty SD rats were randomly divided into five groups(n=8/group): normal group was SD rats group injected with normal saline at left knee joint and administrated orally distilled water, control group was MIA-induced osteoarthritis SD rats group administrated orally distilled water, Indomethacin group was MIA-induced osteoarthritis SD rats group administrated orally indomethacin 2 mg/kg, DGHT(L) group was MIA-induced osteoarthritis SD rats group administrated orally 1280 mg/kg of Daeganghwal-tang, and DGHT(H) group was MIA-induced osteoarthritis SD rats group administrated orally 2560 mg/kg of Daeganghwal-tang. After orally administration of drugs for 4 weeks, gross appearance and histological analysis were used to evaluate the degree of knee cartilage damage. In addition, pro-inflammatory cytokines, bone degrade factor and bone defence factors were analyzed to investigate the anti-inflammatory and cartilage protection effects of Daeganghwal-tang. Also, hematological test, biochemical test, and liver and kidney tissue were analyzed to determine the safety of Daeganghwal-tang. Results : Daeganghwal-tang inhibited the damage of the knee cartilage, and significantly prevented the reduction in cartilage thickness. In addition, the pro-inflammatory cytokines and the bone degrade factor significantly decreased, and the bone defence factors significantly increased. In the safety assessment of Daeganghwal-tang, there were no significant differences among the experimental groups and no abnormal findings were observed. Conclusions : Daeganghwal-tang has anti-inflammatory effect, inhibits cartilage damage, and protects cartilage in MIA-induced osteoarthritis rats.

• The Journal of Engineering Geology
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• v.19 no.4
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• pp.517-528
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• 2009

Statistical analyses of cut-slope stability were performed over approximately 5.7 km section along the National road No. 25, which cross-cuts in NW-SE direction the Cheongwon and Boeun-Gun area, Chungbuk. A measure of slope-stability was established by using direct reinforcement and indirect protection methods in whole section. Orientations(dip/dip direction) of the slopes, foliations(bedding), cleavages and joints were measured in total of 30 slope sites. The results analyzed using stereographic projection indicate that major directions of the slopes come out predominantly in three directions: 1) $58^{\circ}/095^{\circ}$, 2) $60^{\circ}/296^{\circ}$ and 3) $59^{\circ}/212^{\circ}$. In analyses of dip direction and frequency of cut-slopes established by reinforcement and protection methods, slopes with dip direction of $80-120^{\circ}$ and $280-320^{\circ}$ mostly occur. However, slopes with dip direction of $0-80^{\circ}$(N and NW) and $120-160^{\circ}$(SE) are not distributed in the study area. Failure aspects were analyzed for three major directions of the slopes, respectively. The results of failure aspects analyzed indicate that slopes in the study area could generate various failures as the results of intersection and/or intersection combination among joints, foliations(bedding) and cleavages. However, possibility of failure in a slope of major direction No. 3 is statistically very low because of low frequency in total number of slopes with the direction and of formation of small scale-slopes geographically, although the slope might generate all aspects of failure-modes.

• Korean Security Journal
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• no.62
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• pp.113-134
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• 2020

This study was conducted to examine the influence of the psychological health of the released offenders on their adaptation to community. Researchers analyzed the survey data of 216 participants who received joint marriage support from the Korea Legal Protection and Welfare Corporation. The results showed that the education level, marriage status, and monthly income were having a positive influence on the community adaptation of the released offenders, and the higher the depression and inter-personality among the risk factors of psychological health, the more negative the community adaptation. A higher sense of self-esteem, a psychological health protection factor, has a positive effect on community adaptation while reducing the influence of risk factors, depression and inter-personality. In sum, high self-esteem can contribute to increasing social life satisfaction after release from prison, promote risk factors to positive life changes, suppress negative situations and increase the possibility of successful community adaptation. Although this study confirmed that self-esteem is the most important factor among psychological factors for successful community adaptation of inmates, it will require relevant follow-up research and multi-disciplinary support because psychological factors alone cannot solve the problem.

• Convergence Security Journal
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• v.17 no.3
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• pp.73-81
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• 2017

In April 2009, in the wake of President Obama's Prague speech, the international community held four nuclear sec urity summits from 2010 to 2016 to promote nuclear security and prevent nuclear terrorism. The Nuclear Security S ummit has made significant progress in preventing terrorists from attempting to acquire nuclear weapons or fissile materials, but it still has limitations and problems. To solve this problem, the international community should resume the joint efforts for strengthening bilateral cooperation and multilateral nuclear security regime, and the participating countries should strive to protect their own nuclear materials and fulfill their commitments to secure nuclear facilitie s. Second, the United Nations(UN), the IAEA(International Atomic Energy Agency), International Criminal Police Or ganization(INTERPOL), the Global Initiative to Combat Nuclear Terrorism(GICNT), and the Global Partnership(G P) must continue their missions to promote nuclear security in accordance with the five action plans adopted at the Fourth Nuclear Security Summit. Third, the participating countries should begin discussions on the management and protection of military nuclear materials that could not be covered by the Nuclear Security Summit. Fourth, the intern ational community must strive to strengthen the implementation of the Convention on the Physical Protection of Nuc lear Material(CPPNM) Amendment and International Convention for the Suppression of Acts of Nuclear Terrori sm(ICSANT), prepare for cyber attacks against nuclear facilities, and prevent theft, illegal trading and sabotage invo lving nuclear materials.