Making the Black Box Transparent

1999 ◽  
Vol 92 (9) ◽  
pp. 780-784
Author(s):  
Lawrence M. Lesser
Keyword(s):  
Mathematical Theory ◽  
Black Box ◽  
Mathematical Understanding ◽  
Complete Graphs ◽  
Interpolating Polynomials ◽  
Mathematics Curricula ◽  
Best Fit ◽  
Shed Light

Although introducing technology into our mathematics curricula allows us to tackle problems of size and complexity as never before, we face a danger of introducing tools to students before they have a sufficient understanding of how mathematics content within their reach can be used to shed light on the algorithms within the tools or on the use of the tools themselves. Fortunately, we can view mathematical theory and technology not as opponents but rather as partners that make the whole of mathematical understanding richer than the sum of its parts. Indeed, bringing technology into our classrooms can encourage new questions that technology-free mathematics must answer. This article focuses mainly on a common example in technology-rich mathematics curricula, namely, the line of best fit, followed by a discussion of two additional examples—interpolating polynomials and complete graphs. In each case, connections between theory and technology do not appear to be as widely known and used as they could be.

Creating Dynamic Pretrade Models: Beyond the Black Box

2018 ◽  
Keyword(s):  
Functional Form ◽  
Information Leakage ◽  
Black Box ◽  
Sensitivity Analyses ◽  
Stock Selection ◽  
Market Participants ◽  
Box Models ◽  
Portfolio Managers ◽  
Black Box Models ◽  
Shed Light

We provide a framework for investment managers to create dynamic pretrade models. The approach helps market participants shed light on vendor black-box models that often do not provide any transparency into the model’s functional form or working mechanics. In addition, this allows portfolio managers to create consensus estimates based on their own expectations, such as forecasted liquidity and volatility, and to incorporate firm proprietary alpha estimates into the solution. These techniques allow managers to reduce overdependency on any one black-box model, incorporate costs into the stock selection and portfolio optimization phase of the investment cycle, and perform “what-if” and sensitivity analyses without the risk of information leakage to any outside party or vendor.

Modulation of cardiovascular control mechanisms and their interaction

1996 ◽  
Vol 76 (1) ◽  
pp. 193-244 ◽  
Author(s):  
P. B. Persson
Keyword(s):  
Nitric Oxide ◽  
Black Box ◽  
Control Element ◽  
Control Mechanisms ◽  
Severity Of Disease ◽  
The Brain ◽  
Specific Control ◽  
Central Level ◽  
Shed Light

It is generally held that the role of a specific control element can only be understood within its physiological environment. The reviewed studies make it clear that there is a potent interplay between locally produced substances such as adenosine, nitric oxide, prostaglandins, and various others all interacting with the central level of control. This can occur at central sites (e.g., nitric oxide in the brain) or in the periphery (e.g., neural influence on autoregulation). The interactions are more or less pronounced during specific physiological challenges. Furthermore, several of these interactions are altered under pathological circumstances, and in some cases, the interactions seem to maintain or even augment the severity of disease. When more than three parameters participate in an interaction, the resulting regulation may become extremely complex. If these parameters are nonlinearly coupled with each other, the only way to shed light onto the nature of control network is by treating it as a black box. With the use of spectral analysis or nonlinear methods, it is possible to disentangle the fundamental nature of the system in terms of the complexity and stability. Therefore, modern developments in cardiovascular physiology utilizing these techniques, some of which are derived from the "chaos theory," are reviewed.

scholarly journals Learning to be a mother: Comparing two groups of Chinese immigrants in the Netherlands

2019 ◽  
Vol 28 (2) ◽  
pp. 220-241
Author(s):  
Lijie Zheng ◽  
Mariëtte de Haan ◽  
Willem Koops
Keyword(s):  
Social Networks ◽  
Chinese Immigrants ◽  
Black Box ◽  
Immigrant Parents ◽  
Long Distance ◽  
Dense Networks ◽  
Immigrant Mothers ◽  
Parenting Knowledge ◽  
Parental Ethnotheories ◽  
Shed Light

Immigrant parents may have to rebuild their parenting knowledge after migration to keep up with their new milieu. Comparing two subgroups of Chinese immigrants, economic and knowledge immigrants, this study shows that the construction of different parental ethnotheories can be understood through the characteristics of their parenting knowledge acquisition, social networks and networking strategies. Findings from ego-network interviews with 15 economic immigrant mothers and 20 knowledge immigrant mothers indicate that the former tends to obtain practical tips and specific instructions directly from experts and acquire practical help from local, co-ethnic, small and dense networks, while the latter engages in critical peer-based learning in multicultural, open and long-distance networks. This study argues that a social network perspective can shed light on the “black box” of how parenting theories are reconstructed after migration.

The Autocrat’s Advisors: Opening the Black Box of Ruling Coalitions in Tunisia’s Authoritarian Regime

2017 ◽  
Vol 71 (2) ◽  
pp. 330-346 ◽  
Author(s):  
Matt Buehler ◽  
Mehdi Ayari
Keyword(s):  
Middle East ◽  
Social Groups ◽  
Black Box ◽  
Authoritarian Regime ◽  
Insider Threats ◽  
National Archives ◽  
Dominant Parties ◽  
The Military ◽  
Shed Light

Why do autocrats retain some elites as core, long-term members of their ruling coalitions for years, while others are dismissed in months? How and why might the type of elites retained within coalitions vary across time and different autocrats? Although what constitutes an authoritarian regime’s ruling coalition varies across countries, often including the military and dominant parties, this article focuses on one critical subcomponent of it—an autocrat’s cabinet and his elite advisors within it, his ministers. Because coalitions function opaquely to prevent coups, scholars consider their inner-workings a black box. We shed light through an original, exhaustive dataset from the Middle East of all 212 ministers who advised Tunisian autocrats from independence until regime collapse (1956–2011). Extracting data from Arabic sources in Tunisian national archives, we track variation in minister retention to identify which elites autocrats made core, long-term advisors within ruling coalitions. Whereas Tunisia’s first autocrat retained elites as ministers due to biographical similarities, capacity to represent influential social groups, and competence, its second autocrat did not. He became more likely to dismiss types of elites retained under the first autocrat, purging his coalition of ministers perceived to be potential insider-threats due to their favored status under his predecessor.

Shed light on the black box: Using MEG to recover brain activity during tACS

2015 ◽  
Vol 8 (2) ◽  
pp. 381-382 ◽  
Author(s):  
T. Neuling ◽  
P. Ruhnau ◽  
M. Fuscà ◽  
G. Demarchi ◽  
C.S. Herrmann ◽  
...  
Keyword(s):  
Brain Activity ◽  
Black Box ◽  
Shed Light

scholarly journals Analysis on the Performance of a Second-order and a Third-order RLC Circuit of PRBS Generator

2021 ◽  
Vol 1 (1) ◽  
pp. 1-10
Author(s):  
Ahmad’ ‘Athif Mohd Faudzi ◽  
Na Zhang
Keyword(s):  
System Identification ◽  
Black Box ◽  
Second Order ◽  
Order Model ◽  
Complex Signals ◽  
Third Order ◽  
The Third ◽  
Rlc Circuit ◽  
Best Fit ◽  
Sample Time

A pseudo-binary random signal (PRBS) has been widely utilized for system identification in complex signals to develop an experimental approach. PRBS generator is a circuit that generates pseudo-random numbers. This work aims to analyze the best fit value of the PRBS generator with second-order and third-order under-damped black-box RLC circuit of the estimated model. The procedures conducting here can be divided into three parts. First, to design two black boxes using the RLC circuit representing a critically under-damped second-order and third-order system. PRBS generated with maximum-length sequence (MLS) equals 127 bits by using seven shift registers. Second, simulate the PRBS generator using MATLAB software and validate the estimated model from the simulation using the System Identification Tool in MATLAB. Next, connecting hardware RLC circuit and reading input and output signals using an oscilloscope. Finally, 2500 samples of captured data were used for estimation. Then, analyze and compare the best fit of the simulation and experiment with second-order and third-order under-damped black-box RLC circuit. Furthermore, analyze and compare best fit using different sample time. The results showed that the best fit of the second-order model with under-damped black-box RLC circuit was autoregressive with the exogenous term (ARX) 211, where the best fit of the simulation was 99.88%, and the best fit of the experiment was 96.04%. And the results showed that the best fit of the third-order model with an under-damped black-box RLC circuit was ARX 331, where the best fit of the simulation was 99%, and the best fit of the experiment was 94.28%. It was concluded that the best fit value of the second-order was better than the third order. What’s more, the results showed that when the select range is the same, the bigger the sample time, the better the best fit.

scholarly journals Evaluating an Alleged Mimic of the Monarch Butterfly: Neophasia (Lepidoptera: Pieridae) Butterflies are Palatable to Avian Predators

Insects ◽  
2018 ◽  
Vol 9 (4) ◽  
pp. 150 ◽  
Author(s):  
Dale Halbritter ◽  
Johnalyn Gordon ◽  
Kandy Keacher ◽  
Michael Avery ◽  
Jaret Daniels
Keyword(s):  
Danaus Plexippus ◽  
Monarch Butterfly ◽  
Predation Pressure ◽  
Sister Species ◽  
Conservation Priority ◽  
Avian Predators ◽  
Monarch Butterfly Danaus Plexippus ◽  
Best Fit ◽  
Migration Event ◽  
Shed Light

Some taxa have adopted the strategy of mimicry to protect themselves from predation. Butterflies are some of the best representatives used to study mimicry, with the monarch butterfly, Danaus plexippus (Lepidoptera: Nymphalidae) a well-known model. We are the first to empirically investigate a proposed mimic of the monarch butterfly: Neophasia terlooii, the Mexican pine white butterfly (Lepidoptera: Pieridae). We used captive birds to assess the palatability of N. terlooii and its sister species, N. menapia, to determine the mimicry category that would best fit this system. The birds readily consumed both species of Neophasia and a palatable control species but refused to eat unpalatable butterflies such as D. plexippus and Heliconius charithonia (Lepidoptera: Nymphalidae). Given some evidence for mild unpalatability of Neophasia, we discuss the results considering modifications to classic mimicry theory, i.e., a palatability-based continuum between Batesian and Müllerian mimicry, with a quasi-Batesian intermediate. Understanding the ecology of Neophasia in light of contemporary and historical sympatry with D. plexippus could shed light on the biogeography of, evolution of, and predation pressure on the monarch butterfly, whose migration event has become a conservation priority.

Your body is our black box: Narrating nations in second-person fiction by Edna O’Brien and Jennifer Egan

2018 ◽  
Vol 4 (1) ◽  
pp. 42-65 ◽  
Author(s):  
Daniel Aureliano Newman
Keyword(s):  
American Foreign Policy ◽  
Black Box ◽  
Past Tense ◽  
Domestic Sphere ◽  
Second Person ◽  
Governmental Agency ◽  
National Crisis ◽  
Edna O'brien ◽  
Self Formation ◽  
Shed Light

AbstractFor a century, the disorienting effects of second-person narration have seemed peculiarly well suited to representing the experiential confusions and political contradictions of inhabiting a female body in times of national crisis. This essay examines such effects in Edna O’Brien’s A pagan place and Jennifer Egan’s “Black box,” very different narratives that similarly exploit the deictic and ontological uncertainties of second-person address. Second person in O’Brien’s novel participates in its depiction of a sexually naïve rural Irish girl confronting the conflicting pressures of enforced chastity and reproductive futurism in the name of the Irish State. Emphasis is placed on the narrative’s unusual use of past-tense second-person narration and its intriguing overlap with O’Brien’s nonfictional writings. In Egan’s story, the protean and multivocal second person suggests a sinister fusion of individual and governmental agency, effected through the protagonist’s cybernetically-enhanced body. The result is a deceptively simple critique of post-9/11 American foreign policy as an extension of paternalism and patriarchy in the domestic sphere. The patterns investigated in this paper shed light on other recent uses of the second person in other experimental narratives concerned with identity, self-formation among disenfranchised individuals, and resistance to political and cultural oppression.

scholarly journals Lying in the Gallery

October ◽  
2021 ◽  
pp. 53-72
Author(s):  
Pamela L. Lee
Keyword(s):  
Black Box ◽  
Media Environment ◽  
Female Figure ◽  
The World ◽  
The 1960S ◽  
Shed Light ◽  
Immersive Media

Abstract This essay addresses a recent exhibition phenomenon associated with time-based art: the striking preponderance of beds, beanbag chairs, and other horizontal viewing platforms in the staging of such work. Indeed, in black-box galleries around the world, viewers have been increasingly solicited to go horizontal. What might these new modes of display tell us about contemporary cultures of work when compared to historical examples from the 1960s, particularly in regard to the mass phenomenon known as “burnout” in the present? Might such novel conditions of reception shed light on the shifting interactions between humans and computers in what the ethnographer Marcel Mauss called nearly one hundred years ago, the “civilization of latitude”? Departing from Niki de Saint Phalle's She (1966)—an immersive media environment presented as a recumbent female figure—the essay argues that lying in the gallery chimes with technologies of work post-Internet, our incorporation of its media platforms, and the generalization of the network as a ubiquitous and ambient resource.

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