Bubbles

"Speculators may do no harm as bubbles on a steady stream of enterprise. But the position is serious when enterprise becomes the bubble on a whirlpool of speculation."
—JOHN MAYNARD KEYNES

Is investor behavior rational during times of high market volatility, bear, and bull markets? If investors are armed with the knowledge that markets can be vulnerable to irrational exuberance1 And, therefore, causing speculative bubbles, how can they improve their decision-making process during these periods of market change? These questions can begin to be answered by understanding the history and theory of behavioral finance and learning to implement the lessons that it teaches. Given the current academic understanding of behavioral finance theory: how people think and react to market bubbles; the majority of investors, advisors, and institutions do not act rationally during times of changing market conditions. Investors can correct their decision making processes during times of financial bubbles by learning from past market bubbles, understanding behavioral finance theory, learning to implement its concepts through self reflection of one’s rational expectations, recognizing and understanding their mistakes and those of others, and garnering self control of one’s actions and decisions during any type of financial situation.

A bubble is defined as a period of substantial price deviations from a fundamental value. Bubble detection and crash prediction are by default quite tough processes. Financial bubbles are of great importance; their growth attracts media attention, even small households are interested on taking part on this fest. In that state of euphoria where a “perpetual money machine” operates, no one could think that things might go worst. In the early literature developed in the 80’s and 90’s there was not clear evidence on detecting bubbles; empirical evidence was poor and there was absence of well developed econometric tools.

Implementation of bubbles in reinforced reactive powder concrete deep beams due
to reduce their weight are one of the practical solutions. These bubbles could reduce
the beams ultimate strength and increase the mid-span deflection. An experimental
work was carried out to test the effect of bubbles on the behavior of reactive powder
concrete deep beams. Six simply supported deep beam had the same rectangular crosssection,
flexural and shear reinforcement. They were cast with overall height (h) of 340
mm, width (b) of 120 mm and they were classified into two major groups (A and B)
because of their total length (L) 0f (1000 mm and 1400 mm) respectively. The main
parameter in this study were existing bubbles, flexural behavior and shear span to
depth ratio. The results showed that increasing layer of bubbles caused a decreasing
in first load cracking and ultimate loads and increasing in mid span deflection for all
beams. Also, the result showed the existence of bubbles was caused reducing the weight
of deep beam and ultimate load. For deep beam with shear span to depth ratio (1.11)
and with one and two layers the reduction in weight was (9.35% and 18.7%)
respectively, while in other hand, there were reduction in ultimate load with (7.31%
and 11.7%) respectively. Moreover, the reduction in weight of deep beam with shear
span to depth ratio (1.67) and with one and two layers were (13.09% and 26.18%)
respectively resulting reduction in ultimate load (12.5% and 21.8%) respectively.
Therefore, the effect of bubbles for deep beam with shear span to depth ratio (1.11)
more useful than deep beam with shear span to depth ratio (1.67).

Requisite philosophical reframing of bubbles, globes and foams?
Bubbles, balloons and cocoons
Clues to effective bubble pricking from the physics of bubbles?
Clues to bubble pricking from geometry and structural design?
Strategic implications of engaging with psycho-social bubbles?
Psycho-social hyperbubbling: beyond one-bubble credibility and despair?

This paper presents an analytical method to calculate expansion of intumescent coating under heating and in fire. The analytical method is based on a cell-model, which gives solution to expansion of spherical bubbles in viscous fluid when subject to increase in pressure within the bubbles. This paper extends the analytical method to non-uniform temperature field and temperature-dependent viscosity of intumescent melt. The pressure increase inside the bubbles is a result of conversion of intumescent coating from melt to gases at high temperatures. Accuracy of this extended analytical method is assessed by comparison against the cone calorimeter and furnace fire tests on intumescent coating protected steel plates with different intumescent coating thicknesses, steel plate thicknesses, and heating conditions. Comparison of the analytical calculation and test results indicates that the extended cell-model is suitable for quantifying the expansion process of intumescent coating and it gives accurate results for the expansion.

Globally mobile workers are often depicted as isolated individuals and families, who navigate crises and hazards more or less on their own (McNulty et al., 2019; Dabic et al., 2015). However, experiential knowledge suggests that in the case of, for example, assigned-, and self-initiated expatriates as well as multinational professionals, their assignments are rarely undertaken as isolated individuals (Fechter, 2016). Rather, it has been documented that mobile workers across the globe seek contact in ways that suggest the existence of distinct communities (Cohen, 1977). These groupings can in some instances become secluded collectives that effectively insulate foreign nationals from the local socio-cultural environments. In this situation, it is not uncommon to observe nationality-based bonding in places where global mobile workers work on international assignments. In some instances, they are even physically isolated in gated communities (Lauring and Selmer, 2009). Alternatively, globally mobile employees and professional experts can sometimes unite around shared identities and values (Harrington and Seabrooke, 2020; Selmer and de Leon, 1993). Although some research has been conducted on mobile work communities, this theme has generally received limited attention and many questions remain unanswered. This could for example be in relation to their ultimate purpose, their acceptance and rejection criteria, and their robustness.

... Samuel Thibault, François Broquedis, Brice Goglin, Raymond Namyst, and Pierre-André Wacrenier INRIA Futurs - LaBRI 351 cours de la libération 33405 Talence cedex, France {thibault,goglin,namyst,wacrenier}@labri.fr, francois.broquedis@etu.u-bordeaux1.fr Abstract. ...

Recent studies have shown that the local environment of the Sun is a complex one with the presence of several supernova shock bubbles and interstellar clouds. Even within this environment, the Sun is moving with a velocity of about 15 km/s toward the interior of the galaxy. We examine the changes in the local ISM environment experienced by the Sun in the past and then discuss the interaction of the Sun with these different environments. Lastly, we inquire how this must have changed the cosmic ray environment of the earth since this remains one of the few methods to test the changes in the local ISM environment over astronomical time scales. %

Over the past two decades, Chinese cities have experienced real estate booms displaying clear signs of "bubble" elements, including, inter allia, prohibitive residential prices, an accumulation of debt, and severe overbuilding. In 2014, many media commentators claimed that Chinese property markets were about to burst. Yet house prices have started to rise again in major cities, and no significant slowdown has been recorded to date. This chapter addresses the challenges posed by China's residential market dynamics to the bubble theory. Adopting a political economy perspective that breaks with the approaches of real estate economics, it highlights the self-fulfilling logic of the housing booms, resulting from pervasive practices of land value capture by local governments. The paper stresses the inadequacy of the bubble framework to distinguish speculative and "fundamental" explanatory factors of price increases, and provides an alternative reading based on André Orléan's theory of conventions. It is argued that the asymmetric nature of the State's regulation of housing markets-a failure to rein in housing price hikes, yet efficiency in managing downturns-has played a crucial role in shaping the common representation of the market by investors. Beyond the challenge to bubble theory, China's experience of housing booms opens the way for the recognition of alternative paths to finance-led regimes of capital accumulation in the built environment.

in: Chen, P. - Ippoliti, E. (eds). (2017). Methods and Finance. A Unifying View on Finance, Mathematics and Philosophy , pp. 3-15

The view from outside on finance maintains that we can make sense of, and profit from, stock markets’ behavior, or at least few crucial properties of it, by crunching numbers and looking for patterns and regularities in certain sets of data.
The basic idea is that there are general properties and behavior of stock markets that can be detected and studied through mathematical lens, and they do not depend so much on contextual or domain-specific factors. In this sense the financial systems can be studied and approached at different scales, since it is virtually impossible to produce all the equations describing at a micro level all the objects of the system and their relations. The typical view of the externalist approach is the one provided, for instance, by the application of statistical physics. By focusing on collective behaviour, statistical physics neglects all the conceptual and mathematical intricacies deriving from a detailed account of the inner, individual, and at micro level functions of a system. This chapter examines how the view from outside deals with critical issues such as the mathematical modeling (Sect. 2), the construction and interpretation of data (Sect. 3), and the problem of prediction and performativity (Sect. 4).

Bubble tea is a novel soft drink, which consists of tea, syrup and “bubbles”. A 1H NMR screening method for the analysis of constituents and contaminants in bubble tea was developed. A total of 36 bubble tea samples was analyzed, including finished products, which are offered in so-called bubble tea shops and bars, as well as individual components
and raw materials. The screening can detect various sugars such as glucose, fructose, galactose, xylose, maltose, sucrose and lactose. It is additionally possible to quantify substances such as caffeine, benzoic acid, sorbic acid, tartaric acid, acesulfame-K and acetophenone. In most of the samples caffeine was found because of the content of tea. All samples contained fructose and almost all glucose. The samples of
“bubble” raw materials additionally contained maltose and sucrose. The analysis of the possible contamination with acetophenone was negative in all cases. Otherwise, bubble tea is problematic due to the presence of additives because the retailers often did not conform with their obligation
of labelling.

We have calculated the equilibrium shape of the axially symmetric Plateau border along which a spherical bubble contacts a flat wall, by analytically integrating Laplace's equation in the presence of gravity, in the limit of small Plateau border sizes. This method has the advantage that it provides closed-form expressions for the positions and orientations of the Plateau border surfaces. Results are in very good overall agreement with those obtained from a numerical solution procedure, and are consistent with experimental data. In particular we find that the effect of gravity on Plateau border shape is relatively small for typical bubble sizes, leading to a widening of the Plateau border for sessile bubbles and to a narrowing for pendant bubbles. The contact angle of the bubble is found to depend even more weakly on gravity.

Recent studies have shown that the local environment of the Sun is a complex one with the presence of several supernova shock bubbles and interstellar clouds. Even within this environment, the Sun is moving with a velocity of about 15 km/s toward the interior of the galaxy. We examine the changes in the local ISM environment experienced by the Sun in the past and then discuss the interaction of the Sun with these different environments. Lastly, we inquire how this must have changed the cosmic ray environment of the earth since this remains one of the few methods to test the changes in the local ISM environment over astronomical time scales. %

Finansal balonlar, finans piyasasinda dogal bicimde ortaya cikmaktadir ve finansal varliklarin sanal degeri ile gercek degeri arasinda olusan surekli ve sistematik fiyat farkliliklari olarak tanimlanmaktadir. 1990’li yillardan onceki yaygin goruse gore, finansal balonlar genellikle patladiklari zaman fark edilirlerdi ve tahmin edilemezlerdi. Balonlarin etkisini olcmek icin basit bir balon tespit algoritmasi olan LPPL (log-periodic power law) modeli kullanilmaktadir. LPPL modeli, balonun rejimi degistirecegi zamana ait tahminleri veren dogrusal olmayan en kucuk kareler yontemine dayanmaktadir. Bu calismanin amaci, 03.01.1996-15.03.2018 donemi icin BIST 100 endeksinde cokus ve balon etkisini tespit etmektir. Calismada, LPPL modelinin ileri surdugu kaliplarla, BIST 100 serisindeki spekulatif balonlarin gozlenip gozlenemeyecegi; LPPL modelinin spekulatif balonlarin ne zaman sonecegini tahmin etmede ne kadar basarili oldugu incelenmistir.

Methane represents an important greenhouse gas, and its ebullition is a significant way of releasing gas from bottom sediments of shallow fresh waters to the atmosphere. Estimation of ebullition is complicated because of high spatiotemporal variability; however, a hydroacoustical survey represents an effective method for quantifying it. Commonly used vertical beaming in deep waters can be quite limited in very shallow waters. This study was thus aimed to investigate the possibility of using a horizontally oriented sonar beam for gas bubble quantification. Artificially prepared methane bubbles of various sizes, ranging from 2.5 to 905 3 10 23 mL (1.7–12 mm of equivalent spherical diameter), were released from a depth of 6 m in a freshwater reservoir. The acoustic target strength (TS) of these bubbles was observed using both the vertical and horizontal beams of a 120 kHz frequency split-beam sonar. TS obtained in both the vertical and horizontal modes increase with growing bubble size. However, for identical bubble size, the vertical observation gives stronger TS than the horizontal one. Further, TS distribution around mean value is wider with an increase in bubble size, and this distribution is greater in case of the horizontal mode of observation than vertical. It was observed that during bubble rise TS changes for both the vertical and horizontal mode of observation lie within the range of standard deviation of TS measurement; hence, depth is not relevant for TS regression models used in depth up to 6 m.

Gas-liquid-fiber systems are different from conventional gas-liquid-solid systems in that the solid material (i.e., fiber) is flexible, has a large aspect ratio, and forms flocs or networks when its mass fraction is above a critical value. With its wide application to the pulp and paper industry, it is important to investigate the hydrodynamics of gas-liquid-fiber systems. In this paper, 19 parameters that influence gas holdup in gas-liquid-fiber bubble columns are critically examined and then a dimensional analysis based on the Buckingham Pi Theorem is used to derive the dimensionless parameters governing gas-liquid-fiber bubble column hydrodynamics. Seven dimensionless parameters that are related to the fiber effects on gas holdup are further analyzed, and a single dimensionless parameter combining these dimensionless parameters is derived based on a force analysis and experimental results. This dimensionless parameter is shown to be sufficient to quantify the influence of fiber o...

This article applies the mildly explosive/multiple bubbles testing methodology developed by Phillips et al. (2015a, International Economic Review, forthcoming) to examine the recent time series behaviour of the six main London Metal Exchange non-ferrous metals prices. We detect periods of mild explosivity in the cash and 3-month futures price series in each of copper, nickel, lead, zinc and tin, but not in aluminium. We argue that convenience yield, although the formal counterpart to dividend yield in commodity markets, is not a useful basis on which to assess whether observed explosivity is indicative of bubbles. We construct other measures that suggest the observed explosivity in the non-ferrous metals market can be associated with tight physical markets.

Several acoustic and optical techniques have been used for characterizing natural and anthropogenic gas leaks (carbon dioxide, methane) from the ocean floor. Here, single-camera based methods for bubble stream observation have become an important tool, as they help estimating flux and bubble sizes under certain assumptions. However, they record only a projection of a bubble into the camera and therefore cannot capture the full 3D shape, which is particularly important for larger, non-spherical bubbles. The unknown distance of the bubble to the camera (making it appear larger or smaller than expected) as well as refraction at the camera interface introduce extra uncertainties. In this article, we introduce our wide baseline stereo-camera deep-sea sensor bubble box that overcomes these limitations, as it observes bubbles from two orthogonal directions using calibrated cameras. Besides the setup and the hardware of the system, we discuss appropriate calibration and the different automated processing steps deblurring, detection, tracking, and 3D fitting that are crucial to arrive at a 3D ellipsoidal shape and rise speed of each bubble. The obtained values for single bubbles can be aggregated into statistical bubble size distributions or fluxes for extrapolation based on diffusion and dissolution models and large scale acoustic surveys. We demonstrate and evaluate the wide baseline stereo measurement model using a controlled test setup with ground truth information.

While the general discussion focuses on quantitative factors regarding the financial mania in Iceland 2003-2008, this essay focuses on qualitative precipitating factors of what might develop sociologically into a speculative financial bubble.  A comparison to studies by Robert Shiller is used. This essay is thus in essence a study of socio-economics by use of an approach often referred to in the filed of economics as behavioral finance or literary economics.  The aim is creating a different and more holistic viewpoint of past events. Some of those applicable factors are compared to the Roaring Twenties, showing a remarkable similarity between the two periods despite being 70 years apart.  The discussion should show that danger signs could not only be detected by glancing at macro numbers or balance sheets of banks but also by detecting the development of society in Iceland as a whole.

In building constructions, the beam is a very important structural member to carry load of the slab. Bubble beam is a method of virtually eliminating all concrete from the middle of a Beam, which is not performing any structural function, thereby dramatically reducing structural dead load. Bubble beam is a beam whose core is replace with Spherical balls that can be of various sizes and shapes. Usually the Bubble Deck system combines the benefits of factory manufactured elements in controlled conditions along with on-site completion. Some of its major benefits are lower total cost, reduced material use, enhanced structural efficiency, decreased construction time, and is a green technology. In this project the ineffective concrete in the Centre of the beam is replaced with High density polyethylene hollow spheres, using M30 grade of concrete no of beams with and without spherical bubbles were casted to compare weight and flexural strength.