• Earthquakes and Structures
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• v.13 no.3
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• pp.289-297
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• 2017

This paper presents seismic performance and reliability evaluation on steel-timber hybrid shear wall systems composed of steel moment resisting frames and infill light frame wood shear walls. Based on experimental observations, damage assessment was conducted to determine the appropriate damage-related performance objectives for the hybrid shear wall systems. Incremental time-history dynamic analyses were conducted to establish a database of seismic responses for the hybrid systems with various structural configurations. The associated reliability indices and failure probabilities were calculated by two reliability methods (i.e., fragility analysis and response surface method). Both methods yielded similar estimations of failure probabilities. This study indicated the greatly improved seismic performance of the steel-timber hybrid shear wall systems with stronger infill wood shear walls. From a probabilistic perspective, the presented results give some insights on quantifying the seismic performance of the hybrid system under different seismic hazard levels. The reliability-based approaches also serve as efficient tools to assess the performance-based seismic design methodology and calibration of relative code provisions for the proposed steel-timber hybrid shear wall systems.

• Computers and Concrete
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• v.22 no.5
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• pp.439-447
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• 2018

One of the important factors is the infill walls in the change of the structural rigidity, ductility, dynamic and static characteristics of the structures. The infill walls are not generally included in numerical analysis of reinforced concrete (RC) structural system due to lack of suitable theory and the difficulty of calculating the recommended models. In seismic regions worldwide, the residential structures are generally RC buildings with infill wall. Therefore, understanding the contribution of the infill walls to seismic performance of buildings may have a vital importance. This paper investigates the effects of infill walls on seismic performance of the existing RC residential buildings by considering requirements of the Turkish Earthquake Code (TEC). Seismic performance levels of residential RC buildings with and without walls in high-hazard zones were determined according to the nonlinear procedure given in the code. Pushover curves were obtained by considering the effect of masonry infill walls on seismic performance of RC buildings. The analysis results showed that the infill walls beneficially effected to the rigidity, roof displacements and seismic performance of the building.

• Asian Pacific Journal of Cancer Prevention
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• v.13 no.10
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• pp.4959-4962
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• 2012

The objective of this retrospective study was to investigate prognostic factors associated with survival of patients with extensive stage small cell lung cancer (ES-SCLC). Included were 200 patients admitted to the Liberation Army General Hospital with a diagnosis of ES-SCLC. The demographics of patients, disease characteristics, pre-treatment biochemical parameters and therapeutic plan were assessed or evaluated. Univariate analysis found that second-line chemotherapy, radiotherapy, and no liver metastasis were associated with improved survival. Tumor response to first-line chemotherapy and normal initial hemoglobin levels were also associated with a survival benefit (all P-values ${\leq}$ 0.0369). Multivariate Cox regression analysis indicated that liver metastasis and the total number of all chemotherapy cycles were independent prognostic factors of survival. The morbidity risk in patients with liver metastasis was 2.52-fold higher than that in patients without liver metastasis (hazard ratio (HR)=2.52 (1.69-3.76); P<0.0001). However, one unit increase in the total number of chemotherapy cycles decreased the risk of death by 0.86-fold (HR=0.86 (0.80-0.92); P<0.0001). Absence of liver metastasis and ability of a patient to receive and tolerate multiple lines of chemotherapy were associated with longer survival.

• Earthquakes and Structures
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• v.18 no.2
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• pp.249-261
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• 2020

Seismic loss estimation studies require fragility curves which are usually derived using ground motion datasets. Ground motion records can be either in the form of recorded or simulated time histories compatible with regional seismicity. The main purpose of this study is to investigate the use of alternative ground motion datasets (simulated and real) on the fragility curves. Simulated dataset is prepared considering regional seismicity parameters corresponding to Erzincan using the stochastic finite-fault technique. In addition, regionally compatible records are chosen from the NGA-West2 ground motion database to form the real dataset. The paper additionally studies the effects of hazard variability and two different fragility curve derivation approaches on the generated fragility curves. As the final step for verification purposes, damage states estimated for the fragility curves derived using alternative approaches are compared with the observed damage levels from the 1992 Erzincan (Turkey) earthquake (Mw=6.6). In order to accomplish all these steps, a set of representative masonry buildings from Erzincan region are analyzed using simplified structural models. The results reveal that regionally simulated ground motions can be used alternatively in fragility analyses and damage estimation studies.

• Korean Journal of Environmental Agriculture
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• v.30 no.2
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• pp.189-195
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• 2011

BACKGROUND: Wastewaters were collected from 25 sites of two industrial areas of Mymensingh and Gazipur in Bangladesh to assess metallic toxicity of wastewater for irrigation usage. METHODS AND RESULTS: The analyzed wastewaters were slightly alkaline to alkaline in nature and were problematic for irrigation except 3 samples. As per TDS values, 9 samples were rated as fresh water and the rest 16 were classified as brackish water. EC and SAR reflected that all samples were medium salinity (C2), high salinity (C3), very high salinity (C4) and low alkalinity (S1) hazard classes expressed as C2S1, C3S1 and C4S1. Wastewaters of different industries were graded as excellent, good, permissible and doubtful for irrigation purpose as per SSP. According to hardness ($H_T$), wastewater were under moderately hard, hard and very hard classes. Cd, Cr and Cu ions were treated as toxicant for irrigating soils and crops. Zn was problematic for long-term irrigation. The concentrations of Pb, Fe and Na were far below the toxic levels. Synergistic relationships were observed between pH-EC, pH-TDS, EC-TDS, SAR-SSP and SSP-hardness. CONCLUSION(s): If wastewater is applied for irrigation due to the fresh water shortage, it can contaminate soil due to some toxic metal ions.

• Journal of Korean Society of Water and Wastewater
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• v.29 no.3
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• pp.381-393
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• 2015

This study is carried out in order to propose a drought risk assessment methodology. This methodology is required to deal with practical questions that a variety of stakeholder often raise in the course of discussions on mitigation measures. With a focus on the socioeconomic aspect of drought, more particularly, residents' hardship from water scarcity, it suggests basic concepts and a system of methods in order to assess hazard, exposure, vulnerability and risk. The case study shows a considerable possibility of the methodology in evaluating potential levels of damages in a certain area, in identifying the boundary of districts where risk is disproportionately concentrated, and also in understanding the underlying risk factors of those districts. The authors think that the proposed methodology is able to offer risk information in terms of socioeconomic damages, and therefore contribute to reducing information gaps that policy-makers are currently encountered with.

• Proceedings of the Korean Geotechical Society Conference
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• 2008.10a
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• pp.893-903
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• 2008

A method for predicting surface failures which occur during heavy rainfall on mountain slopes is proposed by using the digital land form model that is obtained by reading altitude on a topographical map at 10m grid point space. A depth of a potential failure layer is assumed at each grid point. In the layer, an infiltrated water movement from cell to cell is modeled in the study (cell is a square of the grid). Infiltrated ground water levels which show the three dimensional effects of a topographical factor in an area can be hourly calculated at every cell by the model. The safety factor of every cell is also calculated every hour by the infinite slope stability analysis method with the obtained infiltrated ground water level. Failure potential delineation is defined here as the time when the safety factor becomes less than unity under the assumptions that effective rainfall is 20mm/h and continues 20 hours.

• Advances in environmental research
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• v.1 no.3
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• pp.181-189
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• 2012

Trihalomethanes, produced as a result of chlorination of drinking water, are considered a potential health hazard. The trihalomethane formation potential (THMFP) of a raw water source may indicate the maximum trihalomethanes (THMs) that are likely to be produced when chlorine reacts with natural organic matter (NOM) present in the water. A study was conducted to evaluate the THMFP in seven different drinking water sources in the vicinity of Kalpakkam, a rural township, on the east coast of India. Water from seven stations were analysed for THMFP. THMFP was compared with surrogate parameters such as dissolved organic carbon (DOC), ultraviolet absorbance ($UV_{254}$) and bromide. The data showed that THMFP was high in water from open wells as compared to closed bore wells, possibly due to more photosynthetic activity. Proximity to sea, and consequently the levels of bromide, was an important factor that influenced THM formation. THM surrogate parameters showed good correlation with THMFP.

• Earthquakes and Structures
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• v.7 no.1
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• pp.101-117
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• 2014

This paper presents a reliability-based analysis on seismic performance of timber-steel hybrid shear wall systems. Such system is composed of steel moment resisting frame and infill wood frame shear wall. The performance criteria of the hybrid system with respect to different seismic hazard levels were determined through a damage assessment process, and the effectiveness of the infill wood shear walls on improving the seismic performance of the hybrid systems was evaluated. Performance curves were obtained by considering different target non-exceedance probabilities, and design charts were further established as a function of seismic weight. Wall drift responses and shear forces in wood-steel bolted connections were used as performance criteria in establishing the performance curves to illustrate the proposed design procedure. It was found that the presence of the infill wood shear walls significantly reduced the non-performance probabilities of the hybrid wall systems. This study provides performance-based seismic evaluations on the timber-steel hybrid shear walls in support of future applications of such hybrid systems in multi-story buildings.

• 한국방재학회:학술대회논문집
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• 2008.02a
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• pp.41-44
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• 2008

The purposes of this study are to estimate thestrength of concrete and quantify the deterioration of concrete by a unique X-ray technique with a contrast medium. In order to estimate the strength of concrete, specimens with different water-cement ratios were fabricated using non-air-entrained concrete, air-entrained concrete and mortar to determine the relationship between their compressive strength and the transit dose obtained by the X-ray technique. Also, an experiment to quantify deterioration was carried out on specimens that were subjected to freezing and thawing action to different levels of dynamic elastic modulus. As a result of this experiment, estimation of the strength and relative dynamic elastic modulus of deteriorated mortar, concrete and air-entrained concrete was found feasible by measuring the transit dose by the X-ray technique.