• Structural Engineering and Mechanics
• /
• v.68 no.3
• /
• pp.335-344
• /
• 2018

The execution of an experiment is a complex affair. It includes the preparation of test specimens, the measurement process itself and also the evaluation of the experiment as such. Financial requirements can differ significantly. In contrast, the cost of numerical simulations can be negligible, but what is the credibility of a simulated experiment? Discussions frequently arise concerning the methodology used in simulations, and particularly over the geometric model used. Simplification, rounding or the complete omission of details are frequent reasons for differences that occur between simulation results and the results of executed experiments. However, the creation of a very complex geometry, perhaps all the way down to the resolution of the very structure of the material, can be complicated. The subject of the article is therefore a means of creating the material structure of concrete contained in a test specimen. Because a complex approach is taken right from the very start of the numerical simulation, maximum agreement with experimental results can be achieved. With regard to the automation of the process described, countless material structures can be generated and randomly produced samples simulated in this way. Subsequently, a certain degree of randomness can be observed in the results obtained, e.g., the shape of the failure - just as is the case with experiments. The first part of the article presents a description of a complex approach to the creation of a geometry representing real concrete test specimens. The second part presents a practical application in which the numerical simulation of the compressive testing of concrete is executed using the generated geometry.

• Asian Pacific Journal of Cancer Prevention
• /
• v.15 no.22
• /
• pp.9939-9943
• /
• 2014

Lobaplatin, one of the third - generation platinum compounds, has shown encouraging anticancer activity in a variety of tumor types. However, the efficacy of lobaplatin in ovarian cancer has not been systemically evaluated. In this study, lobaplatin as a single agent and in combination with taxanes was investigated in - vitro and in an in vitro model of ovarian carcinoma. Using the sulforhodamine B (SRB) assay, the cytotoxic effects of lobaplatin alone and in combination with taxanes were compared with cisplatin and carboplatin in seven ovarian cancer cell lines. In addition, in - vitro antitumor activities were evaluated with cisplatin - sensitive and cisplatin - resistant human ovarian cancer xenografts in nude mice. The cytotoxicity of lobaplatin was similar to or higher than that of cisplatin and carboplatin, with $IC_{50}$ values from 0.9 to $13.8{\mu}mol/L$ in a variety of ovarian cancer cells. The combination of lobaplatin with docetaxel yielded enhanced cytotoxic activity in vitro. In addition, in platinum - sensitive ovarian cancer xenografts, lobaplatin alone showed similar antitumor activity to cisplatin and carboplatin. Furthermore, lobaplatin alone or in combination with docetaxel exhibited significant activity in platinum - resistant ovarian cancer xenografts. These results indicate that the use of lobaplatin alone or in combination with docetaxel might be a rational and novel therapeutic strategy for ovarian cancer. Further clinical development of lobaplatin is clearly warranted.

• Journal of Applied Biological Chemistry
• /
• v.50 no.2
• /
• pp.78-84
• /
• 2007

The anti-fibrotic effects of hot water extract of adventitious root culture of Panax ginseng (ARCP) and the possible mechanisms were investigated on $CCl_4-induced$ hepatotoxicity model mice. Fibrosis was induced by a mild treatment of $CCl_4$. Then silymarin as a positive control drug and ARCP or carrier alone as a negative control were treated. Serum GPT, GOT and ALP activity levels were lowered by 25, 21 and 11% for silymarin treated group and by 48, 39 and 14% for ARCP treated group compared to carrier treated alone. Hepatic collagen for ARCP treatment group was reduced by 18% and MDA contents decreased a little more. Pro-fibrotic gene ($TGF-{\beta}1$, TIMP-1 and ${\alpha}-SMA$) expression increased following the $CCl_4$ treatment, but both the silymarin and the ARCP treatments decreased the expressions of these genes by 20% to 50%. The antioxidant effect of ARCP was studied by DPPH free radical scavenging activity. In addition, a generation of reactive oxygen species (ROS) was also reduced in $H_2O_2-treated$ HepG2 cells upon the ARCP treatment. In summary, ARCP has antioxidant property, and can have some protection against oxidative stress; more importantly, ARCP can efficiently protect mice against $CCl_4-induced$ fibrosis.

• Journal of Korean Society for Atmospheric Environment
• /
• v.29 no.2
• /
• pp.135-151
• /
• 2013

This study has been carried out to analyze the sensitivity of ozone concentrations by employing different options of cumulus parameterization schemes (CPSs) and microphysics schemes in MM5 models. These sensitivity tests were applied to long-range transport case of higher ozone over Northeast Asia. Employed CPS schemes are Betts-Miller (BM), Grell (GR), Kain-Fritsch2 (KF2), Anthes-Kuo (AK), None scheme (grid scale physics only), and four microphysics used here are Simple ice, Reisner1, Reisner2, Schultz scheme in MM5. We chose two cases of high ozone long range transport case by employing both concentrations ozone level and backward trajectory model. The results showed that modeled ozone concentrations indicated about 10% differences among CPSs. Of the all options, GR and KF2 (for CPS), and Rersiner-1 and Resiner-2 (for microphysics) showed relatively good and stable variations against ensemble mean values. For both CPS and microphysics schemes, the difference of precipitation arising from different parameterization schemes was significant by itself, but the resultant ozone variations showed only marginal. But the cloud fraction differences arising from different parameterization schemes showed better correlation with ozone variations than precipitation differences, indicating that the photochemical ozone generation variations is more dominant by cloud fraction than wet removal process for high and long-ranged transported ozone cases over Northeast Asia.

• Journal of Microbiology and Biotechnology
• /
• v.27 no.6
• /
• pp.1163-1170
• /
• 2017

Clostridium difficile releases two exotoxins, toxin A and toxin B, which disrupt the epithelial cell barrier in the gut to increase mucosal permeability and trigger inflammation with severe diarrhea. Many studies have suggested that enteric nerves are also directly involved in the progression of this toxin-mediated inflammation and diarrhea. C. difficile toxin A is known to enhance neurotransmitter secretion, increase gut motility, and suppress sympathetic neurotransmission in the guinea pig colitis model. Although previous studies have examined the pathophysiological role of enteric nerves in gut inflammation, the direct effect of toxins on neuronal cells and the molecular mechanisms underlying toxin-induced neuronal stress remained to be unveiled. Here, we examined the toxicity of C. difficile toxin A against neuronal cells (SH-SY5Y). We found that toxin A treatment time- and dose-dependently decreased cell viability and triggered apoptosis accompanied by caspase-3 activation in this cell line. These effects were found to depend on the up-regulation of reactive oxygen species (ROS) and the subsequent activation of p38 MAPK and induction of $p21^{Cip1/Waf1}$. Moreover, the N-acetyl-$\text\tiny L$-cysteine (NAC)-induced down-regulation of ROS could recover the viability loss and apoptosis of toxin A-treated neuronal cells. These results collectively suggest that C. difficile toxin A is toxic for neuronal cells, and that this is associated with rapid ROS generation and subsequent p38 MAPK activation and $p21^{Cip1/Waf1}$ up-regulation. Moreover, our data suggest that NAC could inhibit the toxicity of C. difficile toxin A toward enteric neurons.

• Journal of the Korea Organic Resources Recycling Association
• /
• v.28 no.1
• /
• pp.83-95
• /
• 2020

The economic issue of the period of return versus investment has emerged to efficiently utilize the thermal energy of public resource recovery facilities using waste and private thermal source facilities using BIO-SRF. Accordingly, the optimum temperature and pressure facilities are required beyond the traditional designed, constructed and operated. In this study, we analyzed current energy output by different heat and pressure model in domestic facilities, and calculated the characteristics of green-house gas emission. In order to, utilize the thermal energy producing facilities using waste and biomass fuel more efficiently, it is temperature and pressure, which will lead to more lucrative investment and return as well.

• Journal of the Korean Society of Systems Engineering
• /
• v.12 no.1
• /
• pp.73-87
• /
• 2016

Combining power generation and water production by desalination is economically advantageous. Most desalination projects use fossil fuels as an energy source, and thus contribute to increased levels of greenhouse gases. Environmental concerns have spurred researchers to find new sources of energy for desalination plants. The coupling of nuclear power production with desalination is one of the best options to achieve growth with lower environmental impact. In this paper, we will per-form a sensitivity study of coupling nuclear power to various combinations of desalination technology: {1} thermal (MSF [Multi-Stage Flashing], MED [Multi-Effect Distillation], and MED-TVC [Multi-Effect Distillation with Thermal Vapour Compression]); {2} membrane RO [Reverse Osmosis]; and {3} hybrid (MSF-RO [Multi-Stage Flashing & Reverse Osmosis] and MED-RO [Multi-Effect Distillation & Reverse Osmosis]). The Korean designed reactor plant, the APR1400 will be modeled as the energy production facility. The economical evaluation will then be executed using the computer program DEEP (Desalination Economic Evaluation Program) as developed by the IAEA. The program has capabilities to model several types of nuclear and fossil power plants, nuclear and fossil heat sources, and thermal distillation and membrane desalination technologies. The output of DEEP includes levelized water and power costs, breakdowns of cost components, energy consumption, and net saleable power for any selected option. In this study, we will examine the APR1400 coupled with a desalination power plant in the Kingdom of Saudi Arabia (KSA) as a prototypical example. The KSA currently has approximately 20% of the installed worldwide capacity for seawater desalination. Utilities such as power and water are constructed and run by the government. Per state practice, economic evaluation for these utilities do not consider or apply interest or carrying cost. Therefore, in this paper the evaluation results will be based on two scenarios. The first one assumes the water utility is under direct government control and in this case the interest and discount rate will be set to zero. The second scenario will assume that the water utility is controlled by a private enterprise and in this case we will consider different values of interest and discount rates (4%, 8%, & 12%).

• Journal of Satellite, Information and Communications
• /
• v.7 no.3
• /
• pp.1-7
• /
• 2012

In this paper, we was performed the interference analysis to determine an optimal coexisting criteria for the european digital video broadcasting service (DVB-T2) and the IMT-advanced LTE based TV Band Device (TVBD). The TVBD was equipped with the spectrum cognition method. To this end, we set the various transmission parameters, that includes the emission and blocking mask, antenna height and gain, transmission power and bandwidth, channel model etc. Based on this parameters, we were calculated the allowable transmit power, the number of TVBD and the change in probability of interference for the TVBD user operating in the adjacent channels of the DVB-T2 user. Also this paper presents how many TVBD users can sharing with DVB-T2 for spectral cognition performance.

• Journal of the Korea Academia-Industrial cooperation Society
• /
• v.18 no.1
• /
• pp.287-294
• /
• 2017

BIM technology has been used in the domestic AEC field since the middle 2000s. BIM has proved its worth in cutting-edge buildings, mega-buildings and freeform buildings in particular. Many freeform buildings could not be completed due to the low level of construction technique. However, many successful cases emerged after adopting digital technology, including BIM which encouraged architects to challenge freeform designs. The modeling software that can generate the freeform shape are not usually able to build the efficient BIM data type in the AEC industry. In this study a process model of the parametric freeform construction member generation and conversion to BIM data is shown and the prototype system is demonstrated.

• Journal of Advanced Navigation Technology
• /
• v.19 no.5
• /
• pp.345-353
• /
• 2015

In this paper, we proposed an information fusion method for enhancement of automatic dependent surveillance - broadcast (ADS-B) system which is one of the next generation navigation system. Although ADS-B provides better performance than traditional radar, ADS-B still has error due to dependence of global navigation satellite system (GNSS) information. In this paper, we improved the ADS-B performance using information fusion of multilateration (MLAT) and wide area multilateration (WAM). Information fusion provides accurate data compared to original data. Mostly, information fusion methods use Kalman filter or IMM(interacting multiple model) filter as a subfilter. However, we used Robust IMM filter as a subfilter to improve the aircraft tracking performance. Also, we use actual ADS-B data not virtual data to increase reliability of our information fusion method.