Dynamic Behavior of Precast Concrete Beam-Column Sub-Assemblages with High Performance Connections Subjected to Sudden Column Removal Scenario

Unbonded posttensioned precast concrete (UPPC) structure has shown its excellent aseismic performance in laboratory tests and earthquake investigation. However, the progressive collapse behavior of UPPC subjected to column removal scenario is still unclear. To fill this knowledge gap, two 1/2 scaled UPPC beam-column sub-assemblages were tested under a penultimate column removal scenario. The dynamic test results indicated that UPPC sub-assemblages have desirable load redistribution capacity to mitigate progressive collapse. The failure modes of the sub-assemblages observed in dynamic test were quite similar to that in static counterparts

On the possibility for constraining cosmic topology from the celestial distribution of astronomical objects

We present a method to constrain cosmic topology from the distribution of astronomical objects projected on the celestial sphere. This is an extension of the 3D method introduced in Fujii & Yoshii (2011) that is to search for a pair of pairs of observed objects (quadruplet) linked by a holonomy, i.e., the method we present here is to search for a pair of celestial sphere $n$-tuplets for $n \geq 3$. We find, however, that this method is impractical to apply in realistic situations due to the small signal to noise ratio. We conclude therefore that it is unrealistic to constrain the topology of the Universe from the celestial distribution, and the 3D catalogs are necessary for the purpose.Comment: 4 pages, 1 figure, accepted for publication in A&A (2011

A CASE STUDY OF ENGINEERING ETHICS: LESSON LEARNED FROM BUILDING COLLAPSE DISASTER TOWARD MALAYSIAN ENGINEERS

This paper presents the case study on the Hotel New World tragedy. The building collapsed on 15th March 1986 and an investigation was conducted to determine the main cause of this tragedy. There were several speculations made on the cause of the collapse such as internal explosion, bad concrete mixture and swampy land affecting the building’s foundations. However, after thorough investigations, these speculations were proved to be inappropriate and the main cause was found to be due to the engineer’s miscalculation during the designing stage which leads to this catastrophic failure of the building. Rescue operation was initiated immediately after the collapse to rescue the victims and the aftermath of this tragedy had led to multiple reclamations. These reclamations include the endorsement of Building Control Act 1989 along Building Control (Accredited Checkers) Regulations 1989 as a stricter quality control measure. The analysis shows that this case may be due to unwanted mistakes or negligence of the engineers in carrying out their duties. Several actions were taken according to the ethical theories and codes of ethics. However after the analysis and evaluation were done, duty ethics and right ethics were more relevant to the collapse of Hotel New World case as compared to the other ethical theories and thus reclamations were done based on duty ethics and right ethic

A CASE STUDY OF ENGINEERING ETHICS: LESSON LEARNED FROM BUILDING COLLAPSE DISASTER TOWARD MALAYSIAN ENGINEERS

This paper presents the case study on the Hotel New World tragedy. The building collapsed on 15th March 1986 and an investigation was conducted to determine the main cause of this tragedy. There were several speculations made on the cause of the collapse such as internal explosion, bad concrete mixture and swampy land affecting the building’s foundations. However, after thorough investigations, these speculations were proved to be inappropriate and the main cause was found to be due to the engineer’s miscalculation during the designing stage which leads to this catastrophic failure of the building. Rescue operation was initiated immediately after the collapse to rescue the victims and the aftermath of this tragedy had led to multiple reclamations. These reclamations include the endorsement of Building Control Act 1989 along Building Control (Accredited Checkers) Regulations 1989 as a stricter quality control measure. The analysis shows that this case may be due to unwanted mistakes or negligence of the engineers in carrying out their duties. Several actions were taken according to the ethical theories and codes of ethics. However after the analysis and evaluation were done, duty ethics and right ethics were more relevant to the collapse of Hotel New World case as compared to the other ethical theories and thus reclamations were done based on duty ethics and right ethic

A CASE STUDY OF ENGINEERING ETHICS: LESSON LEARNED FROM BUILDING COLLAPSE DISASTER TOWARD MALAYSIAN ENGINEERS

This paper presents the case study on the Hotel New World tragedy. The building collapsed on 15th March 1986 and an investigation was conducted to determine the main cause of this tragedy. There were several speculations made on the cause of the collapse such as internal explosion, bad concrete mixture and swampy land affecting the building’s foundations. However, after thorough investigations, these speculations were proved to be inappropriate and the main cause was found to be due to the engineer’s miscalculation during the designing stage which leads to this catastrophic failure of the building. Rescue operation was initiated immediately after the collapse to rescue the victims and the aftermath of this tragedy had led to multiple reclamations. These reclamations include the endorsement of Building Control Act 1989 along Building Control (Accredited Checkers) Regulations 1989 as a stricter quality control measure. The analysis shows that this case may be due to unwanted mistakes or negligence of the engineers in carrying out their duties. Several actions were taken according to the ethical theories and codes of ethics. However after the analysis and evaluation were done, duty ethics and right ethics were more relevant to the collapse of Hotel New World case as compared to the other ethical theories and thus reclamations were done based on duty ethics and right ethic

Modeling vesicle traffic reveals unexpected consequences for Cdc42p-mediated polarity establishment

SummaryBackgroundPolarization in yeast has been proposed to involve a positive feedback loop whereby the polarity regulator Cdc42p orients actin cables, which deliver vesicles carrying Cdc42p to the polarization site. Previous mathematical models treating Cdc42p traffic as a membrane-free flux suggested that directed traffic would polarize Cdc42p, but it remained unclear whether Cdc42p would become polarized without the membrane-free simplifying assumption.ResultsWe present mathematical models that explicitly consider stochastic vesicle traffic via exocytosis and endocytosis, providing several new insights. Our findings suggest that endocytic cargo influences the timing of vesicle internalization in yeast. Moreover, our models provide quantitative support for the view that integral membrane cargo proteins would become polarized by directed vesicle traffic given the experimentally determined rates of vesicle traffic and diffusion. However, such traffic cannot effectively polarize the more rapidly diffusing Cdc42p in the model without making additional assumptions that seem implausible and lack experimental support.ConclusionsOur findings suggest that actin-directed vesicle traffic would perturb, rather than reinforce, polarization in yeast

An improved cosmic crystallography method to detect holonomies in flat spaces

A new, improved version of a cosmic crystallography method for constraining cosmic topology is introduced. Like the circles-in-the-sky method using CMB data, we work in a thin, shell-like region containing plenty of objects. Two pairs of objects (quadruplet) linked by a holonomy show a specific distribution pattern, and three filters of \emph{separation, vectorial condition}, and \emph{lifetime of objects} extract these quadruplets. Each object $P_i$ is assigned an integer $s_i$, which is the number of candidate quadruplets including $P_i$ as their members. Then an additional device of $s_i$-histogram is used to extract topological ghosts, which tend to have high values of $s_i$. In this paper we consider flat spaces with Euclidean geometry, and the filters are designed to constrain their holonomies. As the second filter, we prepared five types that are specialized for constraining specific holonomies: one for translation, one for half-turn corkscrew motion and glide reflection, and three for $n$-th turn corkscrew motion for $n=4, 3,$ and 6. {Every multiconnected space has holonomies that are detected by at least one of these five filters.} Our method is applied to the catalogs of toy quasars in flat $\Lambda$-CDM universes whose typical sizes correspond to $z\sim 5$. With these simulations our method is found to work quite well. {These are the situations in which type-II pair crystallography methods are insensitive because of the tiny number of ghosts. Moreover, in the flat cases, our method should be more sensitive than the type-I pair (or, in general, $n$-tuplet) methods because of its multifilter construction and its independence from $n$.}Comment: 12 pages, 8 figures, accepted for publication in A&A (2011

Integrating information theory and adversarial learning for cross-modal retrieval

Accurately matching visual and textual data in cross-modal retrieval has been widely studied in the multimedia community. To address these challenges posited by the heterogeneity gap and the semantic gap, we propose integrating Shannon information theory and adversarial learning. In terms of the heterogeneity gap, we integrate modality classification and information entropy maximization adversarially. For this purpose, a modality classifier (as a discriminator) is built to distinguish the text and image modalities according to their different statistical properties. This discriminator uses its output probabilities to compute Shannon information entropy, which measures the uncertainty of the modality classification it performs. Moreover, feature encoders (as a generator) project uni-modal features into a commonly shared space and attempt to fool the discriminator by maximizing its output information entropy. Thus, maximizing information entropy gradually reduces the distribution discrepancy of cross-modal features, thereby achieving a domain confusion state where the discriminator cannot classify two modalities confidently. To reduce the semantic gap, Kullback-Leibler (KL) divergence and bi-directional triplet loss are used to associate the intra- and inter-modality similarity between features in the shared space. Furthermore, a regularization term based on KL-divergence with temperature scaling is used to calibrate the biased label classifier caused by the data imbalance issue. Extensive experiments with four deep models on four benchmarks are conducted to demonstrate the effectiveness of the proposed approach.Computer Systems, Imagery and Medi