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A Matroid Extension Result, James Oxley Jan 2019

A Matroid Extension Result, James Oxley

Faculty Publications

Adding elements to matroids can be fraught with difficulty. In the Vámos matroid V 8 , there are four pairs X 1 , X 2 , X 3 , and X 4 that partition E(V 8 ) such that (X 1 ∪ X 2 , X 3 ∪ X 4 ) is a 3-separation while exactly three of the local connectivities (X 1 , X 3 ), (X 1 , X 4 ), (X 2 , X 3 ), and (X 2 , X 4 ) are one, with the fourth being zero. As is well known, there is no …

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A Splitter Theorem For 3-Connected 2-Polymatroids, James Oxley, Charles Semple, Geoff Whittle Jan 2019

A Splitter Theorem For 3-Connected 2-Polymatroids, James Oxley, Charles Semple, Geoff Whittle

Faculty Publications

Seymour’s Splitter Theorem is a basic inductive tool for dealing with 3-connected matroids. This paper proves a generalization of that theorem for the class of 2-polymatroids. Such structures include matroids, and they model both sets of points and lines in a projective space and sets of edges in a graph. A series compression in such a structure is an analogue of contracting an edge of a graph that is in a series pair. A 2-polymatroid N is an s-minor of a 2-polymatroid M if N can be obtained from M by a sequence of contractions, series compressions, and dual-contractions, where …

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Performance Analysis Of A High-Sensitivity Multi-Pinhole Cardiac Spect System With Hemi-Ellipsoid Detectors, Narayan Bhusal, Joyoni Dey, Jingzhu Xu, Kesava Kalluri, Arda Konik, Joyeeta M. Mukherjee, P. Hendrik Pretorius Jan 2019

Performance Analysis Of A High-Sensitivity Multi-Pinhole Cardiac Spect System With Hemi-Ellipsoid Detectors, Narayan Bhusal, Joyoni Dey, Jingzhu Xu, Kesava Kalluri, Arda Konik, Joyeeta M. Mukherjee, P. Hendrik Pretorius

Faculty Publications

Purpose: Single-photon emission computed tomography (SPECT) is a noninvasive imaging modality, used in myocardial perfusion imaging. The challenges facing the majority of clinical SPECT systems are low sensitivity, poor resolution, and the relatively high radiation dose to the patient. New generation systems (GE Discovery, DSPECT) dedicated to cardiac imaging improve sensitivity by a factor of 5–8. This improvement can be used to decrease acquisition time and/or dose. However, in the case of ultra-low dose (~3 mCi) injections, acquisition times are still significantly long, taking 10–12 min. The purpose of this work is to investigate a new gamma camera design with …

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A Chain Theorem For 4-Connected Graphs, Chengfu Qin, Guoli Ding Jan 2019

A Chain Theorem For 4-Connected Graphs, Chengfu Qin, Guoli Ding

Faculty Publications

A sequence of 4-connected graphs G0,G1,.,Gn is called a (G0,Gn)-chain if each Gi (i

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Emergence Of Intrinsic Superconductivity Below 1.178 K In The Topologically Non-Trivial Semimetal State Of Casn3, Y. L. Zhu, J. Hu, F. N. Womack, D. Graf, Y. Wang, P. W. Adams, Z. Q. Mao Jan 2019

Emergence Of Intrinsic Superconductivity Below 1.178 K In The Topologically Non-Trivial Semimetal State Of Casn3, Y. L. Zhu, J. Hu, F. N. Womack, D. Graf, Y. Wang, P. W. Adams, Z. Q. Mao

Faculty Publications

Topological materials which are also superconducting are of great current interest, since they may exhibit a non-trivial topologically-mediated superconducting phase. Although there have been many reports of pressure-tuned or chemical-doping-induced superconductivity in a variety of topological materials, there have been few examples of intrinsic, ambient pressure superconductivity in a topological system having a stoichiometric composition. Here, we report that the pure intermetallic CaSn3 not only exhibits topological fermion properties, but also has a superconducting phase at ∼1.178 K under ambient pressure. The topological fermion properties, including the nearly zero quasi-particle mass and the non-trivial Berry phase accumulated in cyclotron motions, …

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Simplicial Volume Of Links From Link Diagrams, Oliver Dasbach, Anastasiia Tsvietkova Jan 2019

Simplicial Volume Of Links From Link Diagrams, Oliver Dasbach, Anastasiia Tsvietkova

Faculty Publications

The hyperbolic volume of a link complement is known to be unchanged when a half-twist is added to a link diagram, and a suitable 3-punctured sphere is present in the complement. We generalise this to the simplicial volume of link complements by analysing the corresponding toroidal decompositions. We then use it to prove a refined upper bound for the volume in terms of twists of various lengths for links.

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The Gauss Decomposition Of Products Of Spherical Harmonics, Ricardo Estrada Jan 2019

The Gauss Decomposition Of Products Of Spherical Harmonics, Ricardo Estrada

Faculty Publications

The product of two homogeneous harmonic polynomials is homogeneous, but not harmonic, in general. We give formulas for the Gauss decomposition of the product of two homogeneous harmonic polynomials.

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The Funk-Hecke Formula, Harmonic Polynomials, And Derivatives Of Radial Distributions, Ricardo Estrada Jan 2019

The Funk-Hecke Formula, Harmonic Polynomials, And Derivatives Of Radial Distributions, Ricardo Estrada

Faculty Publications

We give a version of the Funk-Hecke formula that holds with minimal assumptons and apply it to obtain formulas for the distributional derivatives of radial distributions in Rn of the type Yk ∇ ∆j (f (r)), where Yk is a harmonic homogeneous polynomial. We show that such derivatives have simpler expressions than those of the form p ∇ (f (r)) for a general polynomial p.

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Backstepping Design For Output Feedback Stabilization For A Class Of Uncertain Systems, Frédéric Mazenc, Laurent Burlion, Michael Malisoff Jan 2019

Backstepping Design For Output Feedback Stabilization For A Class Of Uncertain Systems, Frédéric Mazenc, Laurent Burlion, Michael Malisoff

Faculty Publications

We construct bounded globally asymptotically stabilizing output feedbacks for a family of nonlinear systems, using a dynamic extension and a converging-input-converging-state assumption. We provide sufficient conditions for this assumption to hold, in terms of Lyapunov functions. The novelty is that our construction provides formulas for the control bounds while allowing uncertainties that prevent the use of classical backstepping, and cases where only part of the state variable is available for measurement, without requiring the time lagged states in the feedback control that were required in the artificial delays approach. We illustrate the relevance of our work to engineering in an …

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Benchmarking Substellar Evolutionary Models Using New Age Estimates For Hd 4747 B And Hd 19467 B, Charlotte M. Wood, Tabetha Boyajian, Kaspar Von Braun, John M. Brewer, Justin R. Crepp, Gail Schaefer, Arthur Adams, Timothy R. White Jan 2019

Benchmarking Substellar Evolutionary Models Using New Age Estimates For Hd 4747 B And Hd 19467 B, Charlotte M. Wood, Tabetha Boyajian, Kaspar Von Braun, John M. Brewer, Justin R. Crepp, Gail Schaefer, Arthur Adams, Timothy R. White

Faculty Publications

Constraining substellar evolutionary models (SSEMs) is particularly difficult due to a degeneracy between the mass, age, and luminosity of a brown dwarf. In cases where a brown dwarf is found as a directly imaged companion to a star, as in HD 4747 and HD 19467, the mass, age, and luminosity of the brown dwarf are determined independently, making them ideal objects to use to benchmark SSEMs. Using the Center for High Angular Resolution Astronomy Array, we measured the angular diameters and calculated the radii of the host stars HD 4747 A and HD 19467 A. After fitting their parameters to …

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Conquered: Why The Army Of Tennessee Failed, Benjamin Franklin Cooling Jan 2019

Conquered: Why The Army Of Tennessee Failed, Benjamin Franklin Cooling

Civil War Book Review

Yes, Virginia, to paraphrase David Goldfield’s book title (2002), we are “still fighting the Civil War.” Lest we forget, this is probably a good thing and the carnage of military history is always worth remembering. In this case, trying once again to explain (rationalize) Confederate military collapse, well-known authority on the Army of Tennessee Larry Daniel has taken on other doyens of the war in the western theater from Stanley Horn, Tom Connelly, James McDonough, Steven Woodworth, Earl Hess and Richard McMurray to Grady McWhiney, Nathaniel Hughes, Wiley Sword to Michael Ballard, and others. Sometimes pretentious and sometimes convincing but …

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Michigan’S War: The Civil War In Documents, Kim Crawford Jan 2019

Michigan’S War: The Civil War In Documents, Kim Crawford

Civil War Book Review

Students, researchers and readers interested in the Wolverine State’s contributions and roles in the Civil War have had plenty of sources available to them in local libraries over the years, some of them good ones – from reference volumes and bibliographies published by the Michigan Civil War Centennial Observance Commission and Wayne State University in the 1960s to a number of several annotated and anecdotal histories over the years for general readers by Michigan authors and scholars. Some of these titles, books by Richard Bak, Roger Rosentreter, Frederick Williams, Frank Woodford, and Jack Dempsey, appear in the bibliography of military …

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Upon The Fields Of Battle: Essays In The Military History Of America’S Civil War, Brian Holden Reid Jan 2019

Upon The Fields Of Battle: Essays In The Military History Of America’S Civil War, Brian Holden Reid

Civil War Book Review

In recent years Civil historians have been engaged in some soul-searching as to the direction and indeed content of their studies. Old patterns of thought have been discarded and new ones have been adopted; but to what effect, indeed to what end? To some degree such questions have been prompted by the very success and expansion of military history in general since the 1950s, the growth in the number of its practitioners and the sheer variety of programmes available for the interested student. Yet success has come at a price and led to some self-doubt. And within the United States, …

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River Of Death: The Chickamauga Campaign: Vol. I The Fall Of Chattanooga, John L.S. Daley Jan 2019

River Of Death: The Chickamauga Campaign: Vol. I The Fall Of Chattanooga, John L.S. Daley

Civil War Book Review

Robertson sets the scene for the Union's only major defeat in the Western Theater mainly by giving the fog of war its due, especially that part emanating from flawed staff work, poor communication, and personal grudges. Although this first volume stops short of the culminating battle, he helps us see through some of that fog. First, by providing background information on every commander in the contending armies down to brigade and sometimes regimental level, he elucidates the human factor as few recent campaign histories have. Second, a painstakingly detailed day-by-day narrative enables the reader to understand what commanders knew and …

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War Matters: Material Culture In The Civil War Era, Emily Wells Jan 2019

War Matters: Material Culture In The Civil War Era, Emily Wells

Civil War Book Review

The Civil War remains a pivotal event in southern history, with many themes resurfacing throughout its long academic life. Yet, one area that Civil War historians tend to ignore is material culture, which could open an entirely new vein of interpretation while also underscoring the intersections between race, class, and gender on the battlefield and home front. War Matters offers a refreshing analysis of the economic, social, political, and cultural nuances of the Civil War era through the use of material culture. Editor Joan E. Cashin and her fellow contributors focus on objects as small as pocketbook bibles and as …

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Practical Liberators: Union Officers In The Western Theater During The Civil War, Zachery Fry Jan 2019

Practical Liberators: Union Officers In The Western Theater During The Civil War, Zachery Fry

Civil War Book Review

Union officers in the Civil War’s Western Theater were uninterested in waging a purely moral crusade to free slaves. Instead, they executed pro-emancipation policy as a practical measure after recognizing it would help win the war. So argues Kristopher Teters in this powerful volume focusing on the role Union forces played in the complicated process of emancipation.

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No Property In Man: Slavery And Antislavery At The Nation’S Founding, J. Matthew Ward Jan 2019

No Property In Man: Slavery And Antislavery At The Nation’S Founding, J. Matthew Ward

Civil War Book Review

Noted historian Sean Wilentz offers a weighty and sure-to-be controversial contribution to the extensive historiography on slavery and the original intent of the Constitution. Many historians agree the Constitution was, explicitly or implicitly, a proslavery document, ratified by elite white men many of whom had an interest in slavery as an American institution. But Wilentz contends that the Constitution was more ambivalent toward slavery—even indirectly antislavery in its language—than most scholars acknowledge. The Constitution’s limited protection of slavery could not be equated to the recognition of slavery as a permanent institution. The national governing document failed to specifically recognize property …

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The Hidden Light Of Northern Fires, Meg Groeling Jan 2019

The Hidden Light Of Northern Fires, Meg Groeling

Civil War Book Review

Daren Wang is not the first author to write a Civil War novel, but he is one of the few to get a review in these august pages. Hidden Light is his first novel, but Wang has written for The Atlantic Journal-Constitution, Paste, and Five Points magazine. Additionally, he is the founding executive director of the Decatur Book Festival. Such an active mind was imprinted with an interest in history at an early age when he and his family actually moved to Town Line, New York.

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The Field Of Blood: Violence In Congress And The Road To Civil War, Douglas R. Egerton Jan 2019

The Field Of Blood: Violence In Congress And The Road To Civil War, Douglas R. Egerton

Civil War Book Review

Talented historians can shed new light on familiar stories, sometimes by bringing additional data into the narrative, and some by enlarging the scope and context. In The Field of Blood, Joanne Freeman, the author of an earlier study on political violence, Affairs of Honor, does both. Historians, for example, have devoted numerous books and articles to Congressman Preston Brooks’ brutal caning of Senator Charles Sumner. But it was a revelation, to this reviewer, at least, that the affair led to eight duels or challenges, as the mayhem on the Senate floor rippled across the capital, or that Congressman …

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The Calculus Of Violence: How Americans Fought The Civil War, Lorien Foote Jan 2019

The Calculus Of Violence: How Americans Fought The Civil War, Lorien Foote

Civil War Book Review

Historians walk two tight ropes when they write about the past: one rope divides generalization from particularization and the other divides continuity from change. If a scholar falls off the rope and lands on one side or the other, the result is a book that oversimplifies and distorts the portrait of the past. Historians must find a way to identify broad patterns without losing variations and local nuance; they must explain change over time without losing sight of all that remained the same. It is a difficult balancing act, but when done well, tight-rope walking produces an interpretation of the …

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In God’S Presence: Chaplains, Missionaries, And Religious Space During The American Civil War, Robert Miller Jan 2019

In God’S Presence: Chaplains, Missionaries, And Religious Space During The American Civil War, Robert Miller

Civil War Book Review

In his book In God’s Presence, Benjamin Miller uses the philosophy of spatial theory as a prism to analyze how chaplains and missionaries in the Civil War attempted to preserve antebellum religious foundations and beliefs (“sacred space”) amidst the foreign chaos of battles, death, wounds, camp life, etc. (“profane space”). In doing so, he presents what is perhaps the most thorough and detailed analysis yet written of the religious life of Civil War chaplains and soldiers. Though thankfully more books are emerging of late which deal seriously with religion and the War, few have dealt as specifically as this …

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The Northern Home Front During The Civil War, Jennifer L. Weber Jan 2019

The Northern Home Front During The Civil War, Jennifer L. Weber

Civil War Book Review

The Northern home front officially has become its own subfield of the Civil War. We know this because Paul A. Cimbala and Randall M. Miller have synthesized much of the work on the topic that has come out over the past twenty-five years or so. The Northern Home Front during the Civil War breaks no new ground – it relies almost entirely on secondary sources – but it presents a fine once-over-lightly on many of the issues that confronted the Union during the war.

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Looming Civil War: How Nineteenth-Century Americans Imagined The Future, Joseph W. Pearson Jan 2019

Looming Civil War: How Nineteenth-Century Americans Imagined The Future, Joseph W. Pearson

Civil War Book Review

In Looming Civil War: How Nineteenth-Century Americans Imagined the Future, Jason Phillips argues that in the decades before the Civil War most Americans shared one of two visions of the future. “Some people imagined themselves traveling through time, into a future ahead of them, and forging that future and their lives in the process” (4). Phillips calls this sort of temporal thinking “anticipation,” arguing that it was a feature of more modernist outlooks, and urges readers that it was built on a belief in free will and progress. “Other people imagined themselves stationary while time passed through them. The …

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Vagrants And Vagabonds: Poverty And Mobility In The Early American Republic, Timothy A. Hacsi Jan 2019

Vagrants And Vagabonds: Poverty And Mobility In The Early American Republic, Timothy A. Hacsi

Civil War Book Review

Kristin O’Brassill-Kulfan’s Vagrants and Vagabonds: Poverty and Mobility in the Early American Republic examines the poor relief and criminal bureaucracies in Pennsylvania, New York, and neighboring Mid-Atlantic states that regularly judged, institutionalized, and transported people, often against their will, in the first half of the nineteenth century. In this era of urban growth and early industrialization, poverty was increasingly visible and seen as a fundamental danger. Vagrants and Vagabonds does an excellent job of describing and analyzing themes and approaches that were common throughout the region, and also traces the varied evolution of these approaches in different states.

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Of One Mind And Of One Government: The Rise And Fall Of The Creek Nation In The Early Republic, Steven J. Peach Jan 2019

Of One Mind And Of One Government: The Rise And Fall Of The Creek Nation In The Early Republic, Steven J. Peach

Civil War Book Review

In his first book, Of One Mind and Of One Government: The Rise and Fall of the Creek Nation in the Early Republic, historian Kevin Kokomoor examines the development of a Creek “nation” between the outset of the American Revolution and the War of 1812. His central argument is that the crisis of U.S. expansion spawned a Creek “nation-state” (19). The administrative unit of this polity was the National Council, which oversaw Creek domestic affairs with “coercive legal authority” (19). In his view, the Creek nation-state represented a departure from long-established “cultural and political traditions,” such as community leadership, …

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Annotations: Summer 2019, Tom Barber Jan 2019

Annotations: Summer 2019, Tom Barber

Civil War Book Review

No abstract provided.

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James Riley Weaver’S Civil War: The Diary Of A Union Cavalry Officer And Prisoner Of War, 1863-1865, Meg Groeling Jan 2019

James Riley Weaver’S Civil War: The Diary Of A Union Cavalry Officer And Prisoner Of War, 1863-1865, Meg Groeling

Civil War Book Review

One of the things asked of any new historical publication is that it deal with historiography and suggest proof of necessary change. James Riley Weaver's Civil War meets that requirement by adding substantially to the source literature on military prisoners. Most assume that when President Lincoln issued his new policy concerning the issue of African-American soldiers and their white officers (General Order No. 252, issued July 31, 1863), he also ended the exchange of all prisoners of war. Paroles had proved ineffective on both sides, and the Confederacy insisted on treating black soldiers in a much different manner than white …

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Rapidly Expanding Nuclear Arsenals In Pakistan And India Portend Regional And Global Catastrophe, O.B. Toon, C.G. Bardeen, A. Robock, L. Xia, H. Kristensen, M. Mckinzie, R.J. Peterson, C.S. Harrison, N.S. Lovenduski, R.P. Turco Jan 2019

Rapidly Expanding Nuclear Arsenals In Pakistan And India Portend Regional And Global Catastrophe, O.B. Toon, C.G. Bardeen, A. Robock, L. Xia, H. Kristensen, M. Mckinzie, R.J. Peterson, C.S. Harrison, N.S. Lovenduski, R.P. Turco

Faculty Publications

No abstract provided.

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Borders Of Engagement: Rethinking Scholarship, Activism, And The Academy, Bryan J. Mccann Jan 2019

Borders Of Engagement: Rethinking Scholarship, Activism, And The Academy, Bryan J. Mccann

Faculty Publications

The rhetorical norms around scholarly engagement presume that scholars participate in activist work outside their professional spaces. The avatar of the activist-scholar is the energetic graduate student who fulfills their academic responsibilities while also pursuing activist interests in the “community.” This chapter argues the presumption that activist rhetoricians and other scholars must traverse the border between academy and community reifies the border between the engaged scholar and academia itself. Rhetorical studies, and higher education generally, have always to some degree been invested in traversing the campus-community border. Rhetorical studies, both its communication and composition manifestations, came of age alongside the …

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Sediment Transport And Channel Dynamics Of The Lowermost Mississippi River In Recent Decades, Yijun Xu, Bo Wang, Sanjeev Joshi Jan 2019

Sediment Transport And Channel Dynamics Of The Lowermost Mississippi River In Recent Decades, Yijun Xu, Bo Wang, Sanjeev Joshi

Faculty Publications

Sediment transport and channel dynamics of large alluvial rivers in their lower reaches can strongly influence physical, chemical and biological conditions in their deltaic regions. In this paper, we report the latest assessment on sediment transport and riverbed dynamics of the last 500-km reach of the Mississippi River before entering the Gulf of Mexico. This river reach is also termed as the Lowermost Mississippi River (LmMR), which begins downstream of its division node to the Atchafalaya River. Our assessment shows that in the past 2-3 decades, suspended sediment and bed material loads in the LmMR were significantly higher at the …

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