• Earthquakes and Structures
• /
• v.16 no.2
• /
• pp.185-196
• /
• 2019

One of the shortcomings of seismic bridge design codes is the lack of clarity in defining the role of different seismic isolation systems with linear or nonlinear behavior in terms of R-factor. For example, based on AASHTO guide specifications for seismic isolation design, R-factor for all substructure elements of isolated bridges should be half of those expressed in the AASHTO standard specifications for highway bridges (i.e., R=3 for single columns and R=5 for multiple column bent) but not less than 1.50. However, no distinction is made between two commonly used types of seismic isolation devices, i.e., elastomeric rubber bearing (ERB) with linear behavior, and lead rubber bearing (LRB) with nonlinear behavior. In this paper, five existing bridges located in Iran with two types of deck-pier connection including ERB and LRB isolators, and two bridge models with monolithic deck-pier connection are developed and their R-factor values are assessed based on the Uang's method. The average R-factors for the bridges with ERB isolators are calculated as 3.89 and 4.91 in the longitudinal and transverse directions, respectively, which are not in consonance with the AASHTO guide specifications for seismic isolation design (i.e., R=3/2=1.5 for the longitudinal direction and R=5/2=2.5 for the transverse direction). This is a clear indicator that the code-prescribed R-factors are conservative for typical bridges with ERB isolators. Also for the bridges with LRB isolators, the average computed R-factors equal 1.652 and 2.232 in the longitudinal and transverse directions, respectively, which are in a good agreement with the code-specified R-factor values. Moreover, in the bridges with monolithic deck-pier connection, the average R-factor in the longitudinal direction is obtained as 2.92 which is close to the specified R-factor in the bridge design codes (i.e., 3), and in the transverse direction is obtained as 2.41 which is about half of the corresponding R-factor value in the specifications (i.e., 5).

• Journal of the korean academy of Pediatric Dentistry
• /
• v.33 no.2
• /
• pp.233-243
• /
• 2006

The aim of this study was to investigate the relationship between the C-factor and shrinkage strain values of composite resin and examine the strain values in different incremental filling techniques. Experiment consisted two aims. First, we compared with strain value in two different C-factors(3.7 and 1.0). Second, we examined the strain values in three different filling techniques. The results of the present study can be summarized as follows : 1. High C-factor groups showed higher contraction stress values than low C-factor groups at 900 sec after polymerization. 2. Hybrid resin showed higher contraction stress values than flowable resin in high C-factor cavities. But contraction stress was not revealed significant difference between hybrid resin and flowable resin in low C-factor cavities (P>0.05). 3. Bulk felling with hybrid resin(Group 1) showed high contraction stress and lining with flowable resin followed hybrid resin (Group 5) showed lower contraction stress. 4. Contraction stress were increased during 900 sec after polymerization in high C-factor groups but decreased gradually after 900 sec. 5. Low C-factor groups showed tight marginal seal between resin and cavity wall but high C-factor groups showed gaps formed between resin and cavity wall in part. On the basis above results, layering techniques in high C-factor cavity showed advantages in reducing contraction stress and gap formation between cavity wall and resin restoration.

• Journal of Climate Change Research
• /
• v.9 no.1
• /
• pp.69-74
• /
• 2018

The purpose of this study is to suggest the methodology of $CO_2$ Emission Factor Verification and Quantitative Assessment in Ethylene Product Processes. At first, this study compare the IPCC (Intergovernmental Panel on Climate Change) 1996 Guideline and 2006 Guideline. And analyse methodology for estimating $CO_2$ emission and $CO_2$ emission factor in Ethylene product process. Also analyse cases of estimating $CO_2$ emission factor based on material balance. Methodology of $CO_2$ Emission Factor Verification and Quantitative Assessment are following the categories proposed by GIR (Greenhouse Gas Inventory and Research Center). There are total 12 factors in 8 categories and give 5 or 10 points according to their importance. Also this study suggests necessary data of document to meet the conditions. The result would help estimate accuracy Greenhouse Gas Inventory. Also contribute to establish policy on environmental assessment, air conservation, etc.

• Journal of the Korean housing association
• /
• v.12 no.2
• /
• pp.45-54
• /
• 2001

The purpose of this research was to analyze the correlation between the Apartment Purchase Price Decision Factor and Amenity decision Factor with cognition of the Consumer. The result are as follows; 1. The correlation coefficient between the Apartment Price Decision Factor and Amenity decision Factor with cognition of the Consumer was 0.587. 2. The ranking of the purchase price factor which it prefers were analyzed orientation > sunlight > view > the rising price expectation > natural environment etc. And the ranking of the amenity were analyzed orientation > natural environment > view > sunlight > noise etc. 3. Consumer group was classified the location, sex, year of ages and unit scale. The rank correlation coefficient of (the significant was below 0.05) sex was 0.617~0.644, year of ages was 0.62~0.771 and unit scale was 0.762~0.852. This research proved the fact that the amenity correlated with the apartment purchase price decision factor, so amenity contained an economic value. And this result will be used in decision-making-process of apartment construction.

• Journal of Environmental Science International
• /
• v.7 no.2
• /
• pp.171-176
• /
• 1998

This study was conducted to evaluate water quality utilizing principal component analysis in the Nakdong River Estuary. From the results of analysis, water quality in the Nakdong River Estuary could be explained up to 65.3 Percente by three factors which were Included In river loadlnwastes from the Nakdong River and rainfalls : 39.1%1, sediment resuspension(13.7BS) and metabolism(12.5%). In the eastern part of estuary In flowing the Nakdong River, river loading factor score(factor 1 Pas higher than that In western part. Sediment resuspension factor score(factor 2) was high in shallow water, while metabolism factor score(factor 3) was high in deeper water. For seasonal variations of factors score, factor 1 was h19h- 1y related to rainfall season.

• Journal of the Earthquake Engineering Society of Korea
• /
• v.6 no.2
• /
• pp.29-37
• /
• 2002

The purpose of this study is to provide a fundamental data of earthquake resistant design through the estimation of the response modification factor and nonlinear displacement for moment resisting reinforced concrete frames by linear and nonlinear static analysis. The analysis models are designed in accordance with AIK code and then, estimated the response modification factor and nonlinear displacement of the buildings. The parameters such as story numbers(10, 20, 30), plan ratios(1:1, 1:2) and analysis types(2D, 3D) of building structure are chosen for use in this study. After comparing the results of linear and nonlinear static analysis, the response modification factor is obtained as the product of four factors: ductility factor, strength factor, damping factor and redundancy factor. The response modification factor are close to 3.5 in case of 2 span, 4.3 in case of 3 span and 5.0 in case 4 or more span models regardless number of stories and plan ratios. The nonlinear displacement is evaluated from the ratio of story drift angle(nonlinear drift/linear drift). The ratio of story drift angle increases as story numbers increase and the value varies from 5.85 to 9.34.

• Journal of applied mathematics & informatics
• /
• v.28 no.1_2
• /
• pp.325-331
• /
• 2010

Let a and b be nonnegative integers with 2 $\leq$ a < b, and let G be a Hamiltonian graph of order n with n > $\frac{(a+b-5)(a+b-3)}{b-2}$. An [a, b]-factor F of G is called a Hamiltonian [a, b]-factor if F contains a Hamiltonian cycle. In this paper, it is proved that G has a Hamiltonian [a, b]-factor if $\delta(G)\;\geq\;\frac{(a-1)n+a+b-3)}{a+b-3}$ and $\delta(G)$ > $\frac{(a-2)n+2{\alpha}(G)-1)}{a+b-4}$.

• The Journal of Korean Association of Computer Education
• /
• v.9 no.3
• /
• pp.67-74
• /
• 2006

The purpose of this study is identifying variables that affect to learners' preference toward specific e-learning programs, using an exploratory factor analysis(EFA) method. We extract common factors that explain the correlations among variables. In the result, 8 factors were identified as main influential factors: e-learning program design(1st factor), the purpose of e-learning use(2nd factor), social and cultural issues(3rd factor), demographics(4th factor), organizational needs(5th factor), impacts of e-learning(6th factor), e-learning management(7th factor), and technical issue(8th factor).

• The Korean Journal of Physiology and Pharmacology
• /
• v.26 no.3
• /
• pp.165-174
• /
• 2022

As the mechanism underlying glucose metabolism regulation by oxymatrine is unclear, this study investigated the effects of oxymatrine on pyroptosis in INS-1 cells. Flow cytometry was employed to examine cell pyroptosis and reactive oxygen species (ROS) production. Cell pyroptosis was also investigated via transmission electron microscopy and lactate dehydrogenase (LDH) release. Protein levels were detected using western blotting and interleukin (IL)-1β and IL-18 secretion by enzyme-linked immunosorbent assay. The caspase-1 activity and DNA-binding activity of nuclear factor kappa B (NF-κB) and nuclear factor (erythroid-derived 2)-like 2 protein (Nrf2) were also assessed. In the high glucose and high fat-treated INS-1 cells (HG + PA), the caspase-1 activity and LDH content, as well as Nod-like receptor family pyrin domain containing 3, Gsdmd-N, caspase-1, apoptosis-associated speck-like protein containing a CARD, IL-1β, and IL-18 levels were increased. Moreover, P65 protein levels increased in the nucleus but decreased in the cytoplasm. Oxymatrine attenuated these effects and suppressed high glucose and high fat-induced ROS production. The increased levels of nuclear Nrf2 and heme oxygenase-1 (HO-1) in the HG + PA cells were further elevated after oxymatrine treatment, whereas cytoplasmic Nrf2 and Keleh-like ECH-associated protein levels decreased. Additionally, the elevated transcriptional activity of p65 in HG + PA cells was reduced by oxymatrine, whereas that of Nrf2 increased. The results indicate that the inhibition of pyroptosis in INS-1 cells by oxymatrine, a key factor in its glucose metabolism regulation, involves the suppression of the NF-κB pathway and activation of the Nrf2/HO-1 pathway.

• Journal of Environmental Science International
• /
• v.17 no.4
• /
• pp.405-412
• /
• 2008

Statistical analysis technique was applied to operating parameters and removal efficiency data sets obtained from advanced wastewater treatment plant during 1 year. Through factor analysis three factors derived varimax rotation were selected each plant. Three components explained 96%, 87% of the total variance of the process, respectively. The components on $A_2O$ Plant were identified in the following order : 1) Shortening the SRT during high-flow period, 2) Keeping biomass high on winter 3) factor was related to DO. On DNR plant, we defined them as follows: factor 1, Prolonged the SRT during high-flow period; factor 2 was related to sludge return; factor 3, Influent BOD during low-DO period. This technique was believed to assist operators in identifying priorities to improve operation efficiency.