• Journal of the Computational Structural Engineering Institute of Korea
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• v.28 no.5
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• pp.535-542
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• 2015

A reactor containment acts as a final barrier to prevent leakage of radioactive material due to the possible reactor accidents into external environment. Because of the functional importance of the containment building, the SIT(Structural Integrity Test) for containments shall be performed to evaluate the structural acceptability and demonstrate the quality of construction. In this paper, numerical analyses are presented, which simulate the results obtained from the SIT for a prestressed concrete(PSC) structure. A sophisticate structural analysis model is developed to simulate the structural behavior during the SIT properly based on various preliminary analysis results considering contact condition among structural elements. From the comparison of the analysis and test results based on the acceptance criteria of ASME CC-6000, it can be concluded that the construction quality of the containment has been well maintained and the acceptable performance of new design features has been verified.

• Journal of the Computational Structural Engineering Institute of Korea
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• v.28 no.5
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• pp.523-533
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• 2015

A reactor containment acts as a final barrier to prevent leakage of radioactive material due to the possible reactor accidents into external environment. Because of the functional importance of the containment building, the SIT(Structural Integrity Test) for containments shall be performed to evaluate the structural acceptability and demonstrate the quality of construction. An initial numerical analysis was performed to simulate the results obtained from the SIT for a prestressed concrete(PSC) structure. But the analysis results by the initial model expected smaller displacements than the measured ones by 30% at some locations. Accordingly, the research and development to improve the initial model to corelate the measured results of the SIT more properly have been performed. In this paper, the effects of the loss of concrete due to duct for tendons and the contact of duct and tendons in un-bonded tendon system are mainly evaluated based on the preliminary analysis results. In addition, the importances of the proper definition of mesh connectivity among structural elements of concrete, liner plates, rebars and tendons are discussed.

• Corrosion Science and Technology
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• v.13 no.1
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• pp.20-27
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• 2014

The structures of reinforced concrete has been extensively increased with rapid development of industrial society. Futhermore, these reinforced concretes are easy to expose to severe corrosive environments such as sea water, contaminated water, acid rain and seashore etc.. Thus, corrosion problem of inner steel bar embedded in concrete is very important in terms of safety and economical point of view. In this study, multiple mortar test specimen(W/C:0.4) with six types having different cover thickness each other was prepared and was immerged in seawater solution for five years to evaluate the effect of cover thickness and immersion years to corrosion property of embedded steel bar. And the polarization characteristics of these embedded steel bars was investigated using electrochemical methods such as measuring corrosion potential, cathodic polarization curve, and cyclic voltammogram. At the beginning of immersion, the corrosion potentials exhibited increasingly nobler values with increasing cover thickness. However, after immersed for 5 years, the thicker cover of thickness, the corrosion potentials shifted in the negative direction, and the relationship between corrosion potential and cover thickness was not in good agreement with each other. Therefore, it is considered that the thinner cover of thickness, corrosive products deposited on the surface of the embedded steel bar plays the role as a resistance polarization which is resulted in decreasing the corrosion rate as well as shifting the corrosion potential in the positive direction. As a result, it seemed that the evaluation which corrosion possibility of the reinforced steel would be estimated by only measuring the corrosion potential may not be a completely desirable method. Therefore, it is suggested that we should take into account various parameters, including cover thickness, passed aged years as well as corrosion potential for more accurate assessment of corrosion possibility of reinforced steel which is exposed to partially or fully in marine environment for long years.

• Journal of Science and Technology Studies
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• v.14 no.2
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• pp.1-48
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• 2014

Recently, governance of science and technology emerged as one of most important social problems and as a result it is crucial to understand it in science and technology studies. This article discusses three most important realms in science and technology goverance - research and development, regulation, and social movement - in the concrete Korean contexts. First of all, the Korean state has driven research and development and promoted its commercialization unlike other developed countries. Consequently, this nationalistic view on science disseminated to Korean public and it generated uniformity in research style and organization. Second, science and technology regulations embraced developed countries' policies, leading to its glocalization. As a result, technocratic old governance and new governance including precautionary principle and participatory democracy coexist. Third, the civil society has challenged expertise and state-driven science and technology governance and fueled social movements related to environment, safety, and health issues. The politics of knowledge created by citizens' voluntary participation and collaborative experts made it clear that science and technology should be no longer tool for economic development. In conclusion, we discuss characteristics of science and technology governance in Korea, giving various implication on current research and policy.

• Journal of Radiation Protection and Research
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• v.16 no.2
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• pp.41-54
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• 1991

This paper aimed to analyse dose sensitivity to the controllable parameters of indoor radon $(^{222}Rn)$ and its decay products (Rn-D) by applying the input~output linear system theory. Physical behaviors of $^{222}Rn\;&\;Rn-D$ were analyzed in terms of $(^{222}Rn)$ gas -generation, -migation and -infiltration to indoor environments, and the performance output-function, i. e. mean dose equivalent to Tracho-Bronchial (TB) lung region, was assessed to the following extented ranges of the controllable paramenters; a) the ventilation rate $constant({\lambda}_v)\;:\;0{\sim}50[h^{-l}].\;b)$ the attachment rate $constant({\lambda}_a)\;:\;0{\sim}500[h^{-l}].\;c)$ the unattached-deposition rate constant (${\lambda}^u_d)\;:\;0-50[h-l]$. A linear input-output model was reconstructed from the original models in literatures, as follows, which was modified into the matrices consisting of 111 nodal equations; a) indoor $^{222}Rn\;&\;Rn-D$ Behaviour; Jacobi-Porstendoerfer-Bruno model.

• Food Science and Preservation
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• v.24 no.1
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• pp.134-144
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• 2017

This study evaluated the changes of physiochemical properties, phytochemical compounds (isoflavones and phenolic acids), and biological activity during the fermentation of Doenjang without and with bitter melon powder (BMP). The pH decreased from 6.41-5.83 to 5.81-5.24, during the fermentation of Doenjang, while the acidity increased from 0.42-0.65% to 1.28-1.48%. The viable cell numbers of Bacillus and Yeast, salinity, and total amino acid contents increased at the end fermentation (60 day). Also, the fermented Doenjang (FD) with 10% BMP showed the highest ${\gamma}$-aminobutyric acid (GABA, 129.87 mg/100 g) contents, among all the Doenjang samples. The FD exhibited significantly higher inhibitory activities than unfermented Doenjang (UFD) on radicals and ${\alpha}$-glucosidase. The phytochemical compounds including isoflavone-aglycones and phenolic acids increased, whereas isoflavoneglycosides decreased in the BM following fermentative processing. Moreover, the total phenolic, isoflavone-aglycone, and phenolic acid contents were markedly increased, leading to a general increase in antioxidant and ${\alpha}$-glucosidase inhibition activities after fermentation. These results suggest that BMP may be used to prepare a new type of fermented Doenjang with improved antioxidant and antidiabetic activities.

• International Journal of Railway
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• v.1 no.4
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• pp.149-156
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• 2008

During maintenance or construction works in or at the tracks of railways, high risks for passengers and railway staff, especially for the workers on the construction site exist. The high risks result out of the movement of rail vehicles, like trains or construction vehicles, which must be faced by using any available technical and operational technologies for securing them against the environment. Therefore, it is necessary to evaluate the level of protection continuously and to identify new and innovative methods and technologies for the protection of the gang (construction worker, machines and material). Especially on construction sites at line sections with two or more parallel tracks but also with single tracks, there are still a lot of incidents and accidents mostly with seriously injured persons or fatalities. These were mainly gang members that breach the railway-loading gage. By using proper warning or protection systems, the avoidance of such accidents must be achieved. The latest developments. in gang protection systems concern on the one hand fixed barriers in the middle between the construction site and the operated track and on the other hand construction vehicles equipped with automatic warning systems. The disadvantage of such protection methods is that the gang can be warned against an approaching train but a monitoring of the gang members cannot be performed. Only one part of a potential dangerous situation will be detected. If the gang members will overhear the acoustic warning signal of the security staff and the workers will not leave the danger zone in the track, the driver of the approaching train had no chance to react to the dangerous situation. An accident is often inevitable. While the detection of acoustic warning signals by the gang members working on a construction site is very difficult, the acoustical planning of an automatic warning system has to be designed for an acoustic short range level of one meter besides the construction vehicle. The decision about the use of today's technical warning system (fixed systems, automatic warning systems, etc.) must be geared to the technical feasibility and the level of safety which is needed. Criteria for decision guidance to block a track should be developed by danger estimation and economical variables. To realize the actual jurisdiction and to minimize the hazards of railway operations by the use of construction vehicles near the tracks further developments are needed. This means, that the warning systems have to be enhanced to systems for protection, which monitor the realization of the warning signal as a precondition for giving a movement authority to a train. This method can protect against accidents caused by predictable wrongdoing. The actual state of the art technique of using a collective warning combined with additional security staff is no longer acceptable. Therefore, the Institute of Transportation System of the German Aerospace Center in Braunschweig (Germany) will develop a gang warning and protection system based upon imaging methods, with optical sensors such as video in visible and invisible ranges, radar, laser, and other. The advantage of such a system based on the possibility to monitor both the gang itself and the railway-loading gauge either of the parallel track or of the same track still in use. By monitoring both situations, the system will be able to generate a warning message for the approaching train, that there are obstacles in the track, so that the train can be stopped to prevent an accident. And also the gang workers will be warned, while they breach their area.

• Korean Journal of Microbiology
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• v.54 no.2
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• pp.98-104
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• 2018

Naegleria fowleri and Acanthamoeba spp. are free-living amoebas that are widely distributed in natural environments. Although uncommon, infection with these protozoans can cause fatal disease in humans and animals. In this study, in order to select the appropriate method to survey Naegleria fowleri and Acanthamoeba spp. in water samples, four molecular biology techniques and one commercially available kit for real-time PCR were compared. The results indicated that the duplex real-time PCR was the most sensitive, and could be used to simultaneously detect two different free-living amoebas. Using the duplex real-time PCR approach, the two free-living amoebas were surveyed in three local streams in Daejeon, Republic of Korea. The concentrated free-living amoebas were inoculated onto non-nutrient agar plates which had been spread with heat-inactivated Escherichia coli and incubated for 5~7 days. After incubation, gDNA was extracted and used as the template for amplification by duplex real-time PCR. Acanthamoeba spp. and N. fowleri was detected from ten (83.3%) and two (16.6%) of the twelve samples, respectively. As these two free-living amoebas can be fatal, continuous surveillance is needed to track their distribution in the aquatic environment for the drinking water safety.

• Research in Community and Public Health Nursing
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• v.14 no.3
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• pp.397-406
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• 2003

The purpose of this study is to provide the basic data in order to improve the quality of charged recuperation facilities which are specialized in the old. after finding out the satisfaction degree for the services which are provided in the current charged recuperation facilities specialized in the old and surveying the services which are demanded by users. As for the research method. the subjects were 88 family members of the users in the five charged recuperation facilities, which are specialized in the old and located in Seoul and Incheon. The survey research was executed from 27th July to 15th September, 2002. Then the collected data were analyzed by using the SPSS 10.0 for windows program. The research results are as follows. Firstly, in the satisfaction degree of the user's family about the daily service showed the highest satisfaction degree for the kind service of the staff to the users. In the satisfaction degree about the specialized service of the user's family, the satisfaction degree was high in bedsore prevention, periodical health care, proper medical treatment, family counsel, and adequate disease management. In the satisfaction degree about the facility and environmental service, the satisfaction degree about the surrounding environment of the facility or safety facility, and the comfort condition was high. In the satisfaction degree about the services related to the local society, it was high in the hospital and medical-related field. Secondly, in the demanded services, the demanding degree for worship, mental and spiritual nursing, hospice, funeral service, family meeting, and support for the special vehicle were not so high, but it was shown that they were generally demanded. Thirdly, it was shown that the provided services had an overall high satisfaction degree. In the service satisfaction degree according to the general characteristics of the user's family, it was recognized that there was a significant difference between the distinction of sex and local society related services. Also, there was a significant difference in the satisfaction degree between age and specialized service. Through the above research results, detailed rehabilitation programs such as linguistic treatment and working treatment should be more and more compensated in order to supplement the insufficient points of the services provided by the charged recuperation facility specialized in the old. Additionally, the correlation with the local society such as education and training for specialized human labor, close cooperation among the facilities, and positive participation in local society events are thought to be reinforced.

• Journal of the Korea Concrete Institute
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• v.17 no.2 s.86
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• pp.179-189
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• 2005

Corrosion of steel due to chloride attack is a major concern in reinforced concrete structures which are located in the marine environments. In this case, Fick's 2nd law has been used for the prediction of chloride diffusion related with service life of concrete structures. However, those studies were confined mostly to the single deterioration due to chloride only, although actual environment is rather of combined type. The purpose of the present study is, therefore, to explore the influences of carbonation to chloride attack in concrete structures and to investigate the validity of Fick's law to chloride attack combined carbonation. The test results indicate that the chloride ion profiles from Fick's law using the diffusion coefficient of immersion tests is not reflected the effect of separation of chloride ions in carbonation region but valid in sound region in case of combined action. On the other hand, the chloride ion profiles from Fick's law using the diffusion coefficient of Tang and Nilsson's method coincide with test results under dry-wet condition but not under combined condition. The results of present study may Imply that the new method for the measurement of diffusion coefficient is required to predict the chloride ion profiles in case of combined action at early.