Understanding big consumer opinion data for market-driven product design

Big consumer data provide new opportunities for business administrators to explore the value to fulfil customer requirements (CRs). Generally, they are presented as purchase records, online behaviour, etc. However, distinctive characteristics of big data, Volume, Variety, Velocity and Value or ‘4Vs’, lead to many conventional methods for customer understanding potentially fail to handle such data. A visible research gap with practical significance is to develop a framework to deal with big consumer data for CRs understanding. Accordingly, a research study is conducted to exploit the value of these data in the perspective of product designers. It starts with the identification of product features and sentiment polarities from big consumer opinion data. A Kalman filter method is then employed to forecast the trends of CRs and a Bayesian method is proposed to compare products. The objective is to help designers to understand the changes of CRs and their competitive advantages. Finally, using opinion data in Amazon.com, a case study is presented to illustrate how the proposed techniques are applied. This research is argued to incorporate an interdisciplinary collaboration between computer science and engineering design. It aims to facilitate designers by exploiting valuable information from big consumer data for market-driven product design

Computer simulation of the compressive failure of porous material through Distinct Lattice Spring Model

This paper presents the computer simulation of dynamic failure process of porous material through a discrete numerical method. The motivation of this study is to investigate the influence of porous on the compressive failure of material by using the Distinct Lattice Spring Model (DLSM). Firstly, the basic theory of the DLSM is introduced. Due to its inherit discrete nature, DLSM is more suitable to simulate the fracturing process problems than conventional continuum based methods. Then, the methodology used to represent the porous materials is presented. Following this, details of DLSM modeling on the failure process of the porous material under dynamic loading are provided. Finally, the influence of loading ratio and porous on the final strength of the material are presented and analyzed. It indicates that porous play a significant influence on the dynamic compressive strength of material

Ketamine Inhibits Lung Fluid Clearance through Reducing Alveolar Sodium Transport

Ketamine is a broadly used anaesthetic for analgosedation. Accumulating clinical evidence shows that ketamine causes pulmonary edema with unknown mechanisms. We measured the effects of ketamine on alveolar fluid clearance in human lung lobes ex vivo. Our results showed that intratracheal instillation of ketamine markedly decreased the reabsorption of 5% bovine serum albumin instillate. In the presence of amiloride (a specific ENaC blocker), fluid resolution was not further decreased, suggesting that ketamine could decrease amiloride-sensitive fraction of AFC associated with ENaC. Moreover, we measured the regulation of amiloride-sensitive currents by ketamine in A549 cells using whole-cell patch clamp mode. Our results suggested that ketamine decreased amiloride-sensitive Na+ currents (ENaC activity) in a dose-dependent fashion. These data demonstrate that reduction in lung ENaC activity and lung fluid clearance following administration of ketamine may be the crucial step of the pathogenesis of resultant pulmonary edema

Promjena tlačne čvrstoće zida nakon korozije sulfatom uz visoku koncentraciju Ca2+

At the bedrock section of the auxiliary shaft of the Tong-ting coal mine, the sidewall has varying degradation degrees in different parts. The part on which water flowed is barely corroded, whereas the moist part near the pouring joints is seriously corroded. We first studied the mechanism of this phenomenon by chromatography, X-ray diffraction, and energy-dispersive X-ray spectroscopy. We then used simplified models built by particle flow code software (i.e., particle flow code in three dimensions, PFC3D) to analyse how increasing degradation depth affects compressive strength and failure patterns. The results were as follows. (1) Gypsum and calcite in corrosive water were supersaturated. The part on which water flowed was protected by the crystallized precipitation on the concrete. By contrast, the degradation of the part where water flowed through pouring joints was aggravated by internal crystallization and dissolution. (2) PFC3D numerical simulation indicated that decreases in vertical ultimate stress were strongly linearly correlated with degradation depth. As for the −355.5 m damaged part, reinforcement should be conducted before degradation depth reaches 250 mm. (3) No obvious signs were observed prior to the failure of the corroded sidewall. Therefore, the development of degradation depth should be monitored before degradation parts are reinforced.U pomoćnom oknu rudnika ugljena Tong-ting u pojasu temeljne stijene pojedini dijelovi zida pokazuju različite stupnjeve propadanja. Područja na kojima je tekla voda malo su korodirana, dok su vlažni dijelovi uz izljeve izrazito korodirani. Mehanizmi te pojave najprije su proučavani kromatografijom, rendgenskom difrakcijom i energijski disperzivnom rendgenskom spektroskopijom. Veza između dubine korozije i tlačne čvrstoće te obrasca sloma analizirana je pojednostavljenim modelom utemeljenim na kôdu toka čestica (kôd toka čestica u tri dimenzije, PFC3D). (1) Voda je prezasićena s obzirom na gips i kalcit. Dijelovi preko kojih je voda tekla zaštićeni su precipitatom na betonu. Nasuprot tome, propadanje je pojačano kristalizacijom i otapanjem u nutrini izljeva. (2) Numerička simulacija modelom PFC3D pokazuje linearnu vezu između smanjenja vertikalnog maksimalnog naprezanja i dubine degradacije. Oštećeni dio na −355,5 m trebat će pojačati prije nego korozija dopre do 250 mm dubine. (3) Nisu bili uočeni jasni pokazatelji propadanja prije sloma korodiranog zida. Stoga treba pratiti napredovanje propadanja prije nego uništeni dijelovi budu ojačani

Epigenetic memory in induced pluripotent stem cells.

Somatic cell nuclear transfer and transcription-factor-based reprogramming revert adult cells to an embryonic state, and yield pluripotent stem cells that can generate all tissues. Through different mechanisms and kinetics, these two reprogramming methods reset genomic methylation, an epigenetic modification of DNA that influences gene expression, leading us to hypothesize that the resulting pluripotent stem cells might have different properties. Here we observe that low-passage induced pluripotent stem cells (iPSCs) derived by factor-based reprogramming of adult murine tissues harbour residual DNA methylation signatures characteristic of their somatic tissue of origin, which favours their differentiation along lineages related to the donor cell, while restricting alternative cell fates. Such an 'epigenetic memory' of the donor tissue could be reset by differentiation and serial reprogramming, or by treatment of iPSCs with chromatin-modifying drugs. In contrast, the differentiation and methylation of nuclear-transfer-derived pluripotent stem cells were more similar to classical embryonic stem cells than were iPSCs. Our data indicate that nuclear transfer is more effective at establishing the ground state of pluripotency than factor-based reprogramming, which can leave an epigenetic memory of the tissue of origin that may influence efforts at directed differentiation for applications in disease modelling or treatment