PREDICTION OF RESIDUAL STRENGTH OF COMPOSITE COLUMNS USING FEM ANALYSIS

Fires in buildings cause not only economic losses but also many casualties. A prolonged fire involves the possibility of the damage to structural members, which calls for the repair or reinforcement of the building. Since it is critical to decide whether structural members need reinforcement, the technique to determine the degree of the damage to structural members caused by a fire should be established.  CFT columns are superior to generic steel columns in terms of fire resistance performance thanks to the thermal storage effect of the concrete inside the columns.  Studies have suggested how to reinforce the concrete to further improve the structural strength and fire resistance performance of CFT columns. When CFT columns of a building are damaged by a fire, it is required to determine preciously how serious the structural deterioration of the members is.  The purpose of this study is to evaluate the residual strength of CFT columns damaged by a fire by evaluating the temperature distribution inside the columns and determining the degree of deterioration in the load capacity of concrete and steel in relation to temperature distribution

Proposal of Strength Formula and Type Development of Composite Mega Column to Beam Connections with T-shaped Stiffener

[EN] As buildings are becoming larger, demand for mega-sized composite columns (over 1-meter diameter) is increased. We have developed and commercialized welded built-up CFT column (ACT Column I) since 2005 which are structurally stable and economical using cold-formed steel with rib. However, there has a limit in size of cross section (618 X 618mm) by a fabrication facilities. And due to charateristics of closed cross section, there has a limit to construction of connection of moment frame. Composite mega column (ACT Column II) has same concept of forming closed cross section. But in order to enlarge cross sectional size, thick plate is inserted between cold-formed steels. Since composite mega column can control thickness and width of thick plate, steel or composite beams can be directly attached to the connection. In this study, we propose strength formula of composite mega column to beam connections with T-shaped stiffener as internal diaphragm and verified through finite element analysis and simple tensile experiment.Lee, JH.; Kim, SH.; Kim, BK.; Yom, KS.; Choi, SM. (2018). Proposal of Strength Formula and Type Development of Composite Mega Column to Beam Connections with T-shaped Stiffener. En Proceedings of the 12th International Conference on Advances in Steel-Concrete Composite Structures. ASCCS 2018. Editorial Universitat Politècnica de València. 465-473. https://doi.org/10.4995/ASCCS2018.2018.7016OCS46547

Clinicopathological Characteristics of Male Breast Cancer

PURPOSE: To investigate clinicopathological characteristics and outcomes of male breast cancer (MBC). PATIENTS AND METHODS: We retrospectively analyzed the data of 20 MBC patients in comparison with female ductal carcinoma treated at Yonsei University Severance Hospital from July 1985 to May 2007. Clinicopathological features, treatment patterns, and survival were investigated. RESULTS: MBC consists of 0.38% of all breast cancers. The median age was 56 years. The median symptom duration was 10 months. The median tumor size was 1.7 cm, 27.8% showed node metastasis, and 71.4% were estrogen receptor positive. All 20 cancers were arisen from ductal cells. No lobular carcinoma was found. The incidence of stages 0, I, II, and III in patients were 2, 10, 4, and 3, respectively. All patients underwent mastectomy. One with invasive cancer did not receive axillary node dissection and stage was not exactly evaluated. Adjuvant treatments were determined by pathologic parameters and stage. Clinicopathological parameters and survival rates of MBC were comparable to those of female ductal carcinoma. CONCLUSION: The onset age of MBC was 10 years older and symptom duration was longer than in female patients. No difference in outcomes between MBC and female ductal carcinoma suggests that the biology of MBC is not different from that of females. Therefore, education, an appropriate system for early detection, and adequate treatment are necessary for improving outcomes.ope

Test of patch cosmology with WMAP

We calculate the power spectrum, spectral index, and running spectral index for inflationary patch cosmology arisen from Gauss-Bonnet braneworld scenario using the Mukhanov equation. This patch cosmology consists of Gauss-Bonnet(GB), Randall-Sundrum (RS-II), and four dimensional (4D) cosmological models. There exist several modifications in higher order calculations. However, taking the power-law inflation by choosing different potentials depending on the model, there exist minor changes up to second order corrections. Since second order corrections are rather small in the slow-roll limit, we could not choose a desired power-law model which explains the WMAP data. Finally we discuss the reliability of high order calculations based on the Mukhanov equation by comparing the perturbed equation including 5D metric perturbations. It turns out that first order corrections are reliable, while second order corrections are not proved to be reliable.Comment: 20 pages, 3 figures, final version to appear in IJMP

A Simple Method for Simulating Horizontal Ozone Concentration Fields over Coastal Areas: A Case Study of the Seoul Metropolitan Area, Korea

This paper describes a simple semi-empirical photo chemical simulation method to generate horizontal ozone (O3) concentration fields over coastal areas. Based on a simple semi-empirical photochemical reaction model (SEGRS), consisting of a simple photochemical reaction set and a diagnostic wind model, aggregated VOC emission strength is empirically scaled from measured photochemical gas phase concentrations of (O3-2NO-NO2) against cumulative actinic light flux for the case of relatively weak off-shore geostrophic wind at 850 hPa in sum mer. This scaled emission rate for volatile organic compounds (VOCs) is equally applied to horizontal O3 concentration simulation under on-shore synoptic conditions, and results are com pared with observations. The results indicate that spatial distribution patterns and temporal variations of spatially aver aged ground level ozone concentrations are reasonably well simulated. In addition, from the more than 100 box-form SEGRS simulations, close agreement between simulated and ob served daily maximum O3 concentrations suggests that the semi empirical SEGRS model has great potential in getting horizontal ozone distribution pat terns. This indicates that this simple semi-empirical approach to the simulation of O3 concentration pat terns using SEGRS makes for an easy alternative method in multi-year simulation for impact studies of O3 concentrations by lowering heavy computational cost

C-terminally mutated tubby protein accumulates in aggresomes

The tubby protein (Tub), a putative transcription factor, plays important roles in the maintenance and function of neuronal cells. A splicing defect-causing mutation in the 3'-end of the tubby gene, which is predicted to disrupt the carboxy-terminal region of the Tub protein, causes maturity-onset obesity, blindness, and deafness in mice. Although this pathological Tub mutation leads to a loss of function, the precise mechanism has not yet been investigated. Here, we found that the mutant Tub proteins were mostly localized to puncta found in the perinuclear region and that the C-terminus was important for its solubility. Immunocytochemical analysis revealed that puncta of mutant Tub co-localized with the aggresome. Moreover, whereas wild-type Tub was translocated to the nucleus by extracellular signaling, the mutant forms failed to undergo such translocation. Taken together, our results suggest that the malfunctions of the Tub mutant are caused by its misfolding and subsequent localization to aggresomes.ope