Critical Edge Research Articles

The stakes of situated knowledges

This commentary explores the politics of Dragos Simandan’s (2019) proposal to expand the concept of situated knowledge beyond social difference. I argue that while an expanded conception of situated knowledges is welcome, Simandan’s focus on de-politicized instances of situated knowledge ends up blunting the theory’s critical edge. Any attempt to expand situated knowledge beyond social difference must ensure that we do not lose sight of the ways that our embodied positions within fields of power affect the production of knowledge.

Finding Critical Links for Closeness Centrality

Closeness centrality is a class of distance-based measures in the network analysis literature to quantify reachability of a given vertex (or a group of vertices) by other network agents. In this paper, we consider a new class of critical edge detection problems, in which given a group of vertices that represent an important subset of network elements of interest (e.g., servers that provide an essential service to the network), the decision maker is interested in identifying a subset of critical edges whose removal maximally degrades the closeness centrality of those vertices. We develop a general optimization framework, in which the closeness centrality measure can be based on any nonincreasing function of distances between vertices, which, in turn, can be interpreted as communication efficiency between them. Our approach includes three well-known closeness centrality measures as special cases: harmonic centrality, decay centrality, and [Formula: see text]-step reach centrality. Furthermore, for quantifying the centrality of a group of vertices we consider three different approaches for measuring the reachability of the group from any vertex in the network: minimum distance to a vertex in the group, maximum distance to a vertex in the group, and the average centrality of vertices in the group. We study the theoretical computational complexity of the proposed models and describe the corresponding mixed integer programming formulations. For solving medium- and large-scale instances of the problem, we first develop an exact algorithm that exploits the fact that real-life networks often have rather small diameters. Then we propose two conceptually different heuristic algorithms. Finally, we conduct computational experiments with real-world and synthetic network instances under various settings, which reveal interesting insights and demonstrate the advantages and limitations of the proposed models and algorithms. The online appendices are available at https://doi.org/10.1287/ijoc.2018.0829 .

Structuration of the Surface Layer during Drying of Colloidal Dispersions.

During evaporative drying of a colloidal dispersion, the structural behavior at the air-dispersion interface is of particular relevance to the understanding of the consolidation mechanism and the final structural and mechanical properties of the porous media. The drying interface constitutes the region of initial drying stress that, when accumulated over a critical thickness, leads to crack formation. This work presents an experimental study of top-down drying of colloidal silica dispersions with three different sizes (radius 5, 8, and 13 nm). Using specular neutron reflectivity, we focus on the structural evolution at the free drying front of the dispersion with a macroscopic drying surface and demonstrate the existence of a thick concentrated surface layer induced by heterogeneous evaporation. The reflectivity profile contains a strong structure peak due to scattering from particles in the interfacial region, from which the interparticle distance is deduced. A notable advantage of these measurements is the direct extraction of the corresponding dispersion concentration from the critical total reflection edge, providing a straightforward access to a structure-concentration relation during the drying process. The bulk reservoir of this experimental configuration renders it possible to verify the evaporation-diffusion balance to construct the surface layer and also to check reversibility of particle ordering. We follow the structural evolution of this surface layer from a sol to a soft wet-gel that is the precursor of a fragile skin and the onset of significant particle aggregation that precedes formation of the wet-crust. Separate complementary measurements on the structural evolution in the bulk dispersion are also carried out by small-angle neutron scattering, where the particle concentration is also extracted directly from the experimental curves. The two sets of data reveal similar structural evolution with concentration at the interface and in the bulk and an increase in the degree of ordering with the particle size.

Modeling the intersectionality of processes in the social production of health inequalities

BackgroundThe recent pair of studies by Bauer and Scheim make substantial contributions to the literature on intersectionality and health: a validation study of the Intersectional Discrimination Index and a study outlining a promising analytic approach to intersectionality that explicitly considers the roles of social processes in the production of health inequalities. RationaleIn this commentary, I situate Bauer and Scheim's contribution within the wider landscape of intersectional scholarship. I also respond to emerging concerns about the value of descriptive intersectional approaches, in particular the critique that such approaches blunt the critical edge and transformative aims of intersectionality. Finally, I outline important future directions for intersectional scholarship modeling social processes, in particular, the need for addressing structural determinants of inequalities intersectionally. ConclusionsWhether a study is descriptive or analytic, engagement with theory is essential in order to maintain the critical and transformative edge of intersectionality. Theories of population health such as fundamental causes, social production, and ecosocial theory, should be framed and applied in explicitly intersectional terms. As the field moves toward intersectional evaluations of social processes, attention should be given to all ecological levels but especially the structural/institutional level. This attention includes considering interactions between intersectional social strata and contexts and considering the roles of structural-level discrimination in shaping population health outcomes intersectionally.

SOCIAL PEACE AS A VALUE ORDER

Social peace, as a system of values, is based on the value of solidarity, which must embody a progressive development of humankind towards a unity that is both genuine and realistic in terms of attaining the desired objectives. Social values, such as solidarity, are of huge significance for social peace. They are particularly necessary in the process of building institutions that can maintain social peace without pressure or coercion. Yet, it does not imply superficial affection and sympathy for the human predicament but a sincere and committed advocacy for the general well-being. Thus, if we can raise man’s awareness and sensitivity to social values, we are likely to develop legal institutions that will not only preserve but also attain social peace based on the highest social values. A reasonable approach to this matter entails that the development of such institutions will not lead (with absolute certainty) to establishing a value system based on social peace, but it will certainly lead to identifying the undesirable state of affairs, which is the direct opposite of social peace and a trigger for moving forward.The concept of solidarity which recognizes that individuals can survive in a holistic environment in spite of their specificities leads to the desired social peace; supported by the multi-perspective relationship between “myself” and “others”, it will suppress man’s inherent egoism, and shed a new light on the value-oriented track of being that has no alternative.Thus defined, social peace turns into a value system which may also be designated as an axiological track of moral conduct, eventually leading to "the logic of the heart" (Blaise Pascal) and "the order of the heart" (Max Scheler). Admittedly, it makes social peace somewhat idyllic but not unattainable because a value system, including social peace as a highest value, is a given constant which is governed by its own laws; thus, it cannot be destroyed by immoral and unlawful conduct.This postulate gives law the necessary axiological critical edge. In times of growing legal positivism which can substantiate anything as long as it has the form of law, it will contribute to distinguishing between the acceptable value system, such as social peace, and its antipodes. Establishing a balance within a legal order enables the law to come closer to the ideal of justice, which will suppress man’s inherent egoism (by referring to “others” rather than “myself”) and enable the exercise of common interests.In the context of legal positivism per se, social peace is guaranteed by the rights which are ensured by the monopoly of physical coercion. However, as such, it is not absolutely acceptable because it entails an element of force which may be interpreted as coercion for the sake of (social) peace of the ruling class. As opposed to such a conception of social peace, the axiological stance is that social peace is a value system which does not retreat in times of adversity but steadily progresses, thus defying the evil that coexists with values in all human matters.

The Shortest Path Problem and Its Critical Edge in Uncertain Environment

In order to make strategic, tactical and operational decisions for the shortest path in an uncertain environment. Firstly, the information transmission time expectation-variance shortest path model in uncertain environment is proposed. Secondly, to avoid the interruption of information transmission caused by sudden situations, a fuzzy shortest path critical edge model is established. Then, an improved ant colony algorithm with traffic congestion factor and random variables is developed. Finally, to assess the performance of Improved ant colony algorithm, experiments on a set of 6 benchmark test functions are conducted, and numerical examples of these models are given to illustrate its effectiveness.

Belgrade 1968 protests and the post-evental fidelity: Intellectual and political legacy of the 1968 student protests in Serbia

Even though Belgrade student protests emerged and ended abruptly after only seven days in June of 1968, they came as a cumulative point of a decade-long accumulated social dissatisfaction and antagonisms, as well as of philosophical investigations of the unorthodox Marxists of the Praxis school (Praksisovci). It surprised the Yugoslav authorities as the first massive rebellion after WWII to explicitly criticize rising social inequality, bureaucratization and unemployment and demand free speech and abolishment of privileges. This article focuses on the intellectual destiny and legacy of the eight professors from the Faculty of Philosophy close to the Praxis school, who were identified as the protests? instigators and subsequently expelled from the University of Belgrade due to their ?ethico-political unsuitability?. Under both international and domestic pressure, they were later reemployed in a separate research unit named the Centre for Philosophy and Social Theory, where they kept their critical edge and argued for political pluralism. From the late 1980s onwards, they and their colleagues became politically active and at times occupied the highest positions in Serbia - Dragoljub Micunovic as one of the founders of the modern Democratic Party and the Speaker of the Parliament, former Serbian President and Prime Minister Vojislav Kostunica and former Prime Minister late Zoran Djindjic. Still, while some members became strong anti-nationalists and anti-war activists, other embraced Serbian nationalism, therefore pivoting the intellectual split into the so called First and Second Serbia that marked Serbian society during the 1990s and remained influential to this day.

Giving contingency theory of management accounting and control a critical edge

This paper describes the background of contingency theory and some of its research findings, and offers a critique. There are problems with contingency theory, ranging from a simple lack of clarity in its theoretical statements to subtle issues such as its reliance on a statistical model to show interactions between organisational structure and its impacting variables. The paper examines contingency theory from functionalist perspectives and identifies shortcomings of the theory. It is suggested that the narrow view of contingency theory that relies on responses to generally applicable questionnaire needs to be replaced by an approach that takes into consideration the context of specific organisations.

Giving contingency theory of management accounting and control a critical edge

This paper describes the background of contingency theory and some of its research findings, and offers a critique. There are problems with contingency theory, ranging from a simple lack of clarity in its theoretical statements to subtle issues such as its reliance on a statistical model to show interactions between organisational structure and its impacting variables. The paper examines contingency theory from functionalist perspectives and identifies shortcomings of the theory. It is suggested that the narrow view of contingency theory that relies on responses to generally applicable questionnaire needs to be replaced by an approach that takes into consideration the context of specific organisations.

Designing an anisotropic noise filter for measuring critical dimension and line edge roughness from scanning electron microscope images

The scanning electron microscope (SEM) is often employed in inspecting patterns transferred through a lithographic process. A typical inspection is to measure the critical dimension (CD) and line edge roughness (LER) of each feature in a transferred pattern. Such inspection may be done by utilizing image processing techniques to detect the boundaries of a feature. Since SEM images tend to include a substantial level of noise, a proper reduction of noise is essential before the subsequent process of edge detection. In a previous study, a method of designing an isotropic Gaussian filter adaptive to the noise level was developed. However, its performance for relatively small features was not so good as for large features, especially in the case of LER. The main objective of this study is to improve the design method such that the accuracy of the measured CD and LER is not deteriorated substantially as the feature size decreases. The new design method allows a Gaussian filter to be anisotropic for the better adaptability to the signal and noise, both of which show a substantial level of directional correlation. The cutoff frequency for the direction normal to features is determined to include most of the signal components, and the cutoff frequency in the other direction is set to balance the signal and noise components to be included. This procedure enables a systematic and easy design of the filter. Also, the method of estimating the noise has been modified for higher accuracy. The performance of the new design method has been thoroughly analyzed using the reference images for which feature boundaries are known. It has been shown that the anisotropic filter designed by the proposed method performs better than the isotropic filter from the viewpoint of CD, LER, and power spectral density accuracy.

Traditional conservation strategies still the best option

The conservation movement has lost its critical edge by befriending agribusiness. With deforestation on the rise and a continuous roll-back of environmental protection, it is time to rethink this strategy.

Bayesian approach to determine critical dimensions from scatterometric measurements

Supplement one of the ‘Guide to the Expression of Uncertainties in Measurements (GUM)’ recommends to estimate measurement uncertainties by Monte Carlo calculations. For computationally expensive models, Monte Carlo sampling can be often only realized for a small number of samples. This may cause inaccurate or even useless results for problems with a slow convergence rate. In this paper we apply a recently developed method that enables the Bayesian approach to determine the geometry of photo masks from measurements in extreme ultraviolet (EUV) scatterometry. The key idea of this approach is the construction of an efficient surrogate model which reduces the computational costs of sampling steps by several orders of magnitude. This allows us to use Markov Chain Monte Carlo sampling to determine the posterior distribution of desired critical dimensions of the photo mask geometry. The Bayesian approach leads to substantially larger uncertainties of the critical dimension than the previously employed maximum likelihood approach. The results for critical dimensions and line edge roughness are consistent with independent atomic force measurements of a test photo mask arrays from which scatterometric data were used.

Critical vertices and edges in [formula omitted]-free graphs

A vertex or edge in a graph is critical if its deletion reduces the chromatic number of the graph by one. We consider the problems of deciding whether a graph has a critical vertex or edge, respectively. We give a complexity dichotomy for both problems restricted to H-free graphs, that is, graphs with no induced subgraph isomorphic to H. Moreover, we show that an edge is critical if and only if its contraction reduces the chromatic number by one. Hence, we also obtain a complexity dichotomy for the problem of deciding if a graph has an edge whose contraction reduces the chromatic number by one.

Marxism and education: fragility, crisis, critique

The article rests substantially on the work of John Holloway, especially his early articles in Common Sense: Journal of the Edinburgh Conference of Socialist Economists. On this foundation, it is argued, firstly, that the importance of Marxism resides in its capacity to pinpoint fragilities and weaknesses in the constitution, development and rule of capital in contemporary society. Understanding these fragilities sharpens the critical edge of any movements aimed at social transformation out of the madhouse of capital.

Scaling trends of the critical E × B shear for edge harmonic oscillation onset in DIII-D quiescent H-mode plasmas

Quiescent H-mode (QH-mode) has been identified as an attractive stationary operational regime in tokamaks due to its lack of edge localized modes (ELMs), along with good particle and impurity control aided by the presence of magnetohydrodynamic modes such as the edge harmonic oscillation (EHO) or edge turbulence. Experiments on the DIII-D tokamak explore local access conditions for QH-mode through measurements of the critical edge rotational shear necessary for the transition from a QH-mode with a coherent EHO to a typical ELMy H-mode. The critical E × B shear and EHO frequency are predicted by a nonlinear phase-dynamics model relating the pressure and velocity perturbations in the edge pedestal region. The reduced theoretical model predicts a linear relationship between critical shearing rate and , where is the ion acoustic velocity, Lp the pressure gradient scale length, and the radial width of the mode. This scaling of the critical shearing rate agrees with the experimental trend, although the absolute magnitude of the shearing rate threshold is over-predicted by the model. Through a normalized predicted scaling, the model demonstrates the dynamic transition into and out of QH-mode qualitatively, within a single plasma discharge. The experimental comparison lends insight into improving the theoretical model by including more accurate geometry and toroidal mode number physics for more accurate quantitative predictions.

Influence of chisel edge thinning on helical point micro-drilling performance

Chisel edge thinning can effectively improve the drilling performance of austenitic stainless steel. Four kinds of helical point micro-drills, each with a thinned chisel edge of a distinct length, are fabricated based on the mathematics models of the micro-drill by using a six-axis computer numerical control tool grinder. Micro-drilling experiments on 304 stainless steel are conducted. Drilling performance is evaluated according to the measured and observed micro-hole machining quality, chip morphology, thrust force, and tool wear of the micro-drill tip. With a decrease in the chisel edge length, the micro-holes drilled using thinned micro-drills have small entrance burrs, roundness errors, and regular shapes, which are attributed to an increase in self-centering capability. Owing to increased equivalent chip thickness and different directions of chip flow, micro-drills with thinned chisel edge can generate more small-size chips and improve chip breaking. In addition, the inner cutting edge with a positive rake angle replaces the chisel edge with a negative rake angle to cut the workpiece, significantly reducing the chip curl, thrust force, and tool wear of micro-drills. However, helical point micro-drills with critical chisel edge lengths by thinning exhibit less thrust force and tool wear than do helical point micro-drills with no chisel edge because of the increase in the uncut chip width of the micro-drill. Thus, with the selected parameter range, the optimal helical point micro-drill is the micro-drill with a specific chisel edge length by thinning to improve drilling performance.

Chinese Theories of "Anti-Modern" or Alternative Modernity: Arif Dirlik, Liu Kang, and Wang Hui

In Yuyu Wu’s article, "There and Back Again: A Critical Study on 'Anti-modern Modernity,'" the author discusses the arguments about "anti-modern modernity," raised by Arif Dirlik, Kang Liu and Hui Wang, and compares different contexts in which China’s modernity has been understood and interpreted. Both Dirlik and Liu reflect upon western Critical Theory through analysis of the Chinese experience, while Wang brings this theory back to China. However, in this two-way journey, a structural change occurs. By justifying China’s historical experience through abstract western theories, western Critical Theory has not only lost its sharp critical edge, but also transmogrified into an excuse for the Chinese experience. As a result, the insights of western Critical Theory become blind spots for interpreting the Chinese experience.

Stability results for graphs with a critical edge

The classical stability theorem of Erdős and Simonovits states that, for any fixed graph with chromatic number k+1≥3, the following holds: every n-vertex graph that is H-free and has within o(n2) of the maximal possible number of edges can be made into the k-partite Turán graph by adding and deleting o(n2) edges. In this paper, we prove sharper quantitative results for graphs H with a critical edge, both for the Erdős–Simonovits Theorem (distance to the Turán graph) and for the closely related question of how close an H-free graph is to being k-partite. In many cases, these results are optimal to within a constant factor.

“The Sort of War They Deserve”? The Ethics of Emerging Air Power and the Debate over Warbots

ABSTRACTAs new military technologies change the character of war by empowering agents in new ways, it can become more difficult for our ethics of war to achieve the right balance between moral principle and necessity. Indeed, there is an ever-growing literature that seeks to apply, defend and / or update the ethics of war in light of what is often claimed to be an unprecedented period of rapid advancement in military robotics, or warbots. To increase confidence that our approach to this development finds success in appropriately constraining war, this article compares our current discourse to the ethical debate over the rise of air power during the interwar period. As moral norms largely failed to constrain air power in World War II, by highlighting the interrelated processes of technological change, ethical debate, and the eventual reconciliation of war practice and war ethics, this historical case offers insights that can help military ethicists maintain their “critical edge” as remote and autonomous robotic weapons continue to mature and proliferate.

Time To Enlist in the Analytics Army

Data analytics is the future of getting ahead for engineers and geoscientists in the exploration and production (E&P) business. Three executives of large companies recently played up the growing importance of data-driven employee development, from data science boot camps at BP to the Citizen Data Scientist program at ConocoPhillips. “We have got a data science community that is growing by leaps and bounds,” said Michael Rowley, director of technology and innovation at BP, during a presentation at the recent Data Science Convention 2018 put on by the Data Analytics Study Group of the SPE Gulf Coast Section. “The most powerful way for us to pro-mote data analytics is to give our technical people training so they are fully armed with data analytics tools,” said Greg Leveille, chief technology officer of ConocoPhillips. Those willing to learn and apply these new tools “will have a disproportional impact on each of your companies,” Leveille said, adding “our industry will be populated by people who know and who can do data analytics well.” In a tough job market, data skills could offer a critical edge. If two people are interviewing for a job in unconventional exploration, and one has analytics skills and experience and the other does not, “guess who gets the job,” said Andy Flowers, director of advanced analytics for Marathon Oil. One sign of the times was the number of data scientists asking questions at the gathering. Another was the 400-person crowd at the first-ever gathering. They are building and maintaining the industry’s new data gathering and analysis infrastructure, putting large databases and analytical tools in the hands of engineers, geoscientists, and financial managers. They are a small part of the E&P workforce, are hard to find, and costly to hire. “We feel like we won the lottery when we get a new person in” for the data science team, Flowers said. But engineers and geoscientists will remain central to E&P companies because “you cannot outsource knowledge of the oil industry,” Flowers said. They will be asked to use their experience to focus the work on the most important problems, and apply methods drawing on both traditional and statistical approaches. “People with a good grounding and understanding of physics, combined with analytics, can solve problems that are very hard to solve” with first principles physics, Leveille said. Increasingly, the data-driven tools will also integrate the economic aspects of decision making. Engineering decisions need to be aligned with current corporate goals. An application integrating technical and economic information could help an engineer tailor a gas project development plan based on predicted demand. “Not everything is about geology and physics,” Rowley said. Another priority is to figure out “how to connect up data in the financial space,” he said.