Photograph of a baseball game at Ogden Field on the Armour Institute of Technology campus, likely taken from the Armour Mission or Main... Show morePhotograph of a baseball game at Ogden Field on the Armour Institute of Technology campus, likely taken from the Armour Mission or Main Building at the corner of 33rd and Federal Streets. The building to the north of the field, a former residence, served as a cafeteria in the early 20th century before being converted to a fieldhouse in 1933, then an Armour Research Foundation magnetic recording laboratory in 1947. The building was demolished in 1956. Photographer unknown. Date of photograph is unknown. Date range listed is approximate. Show less
Photograph of the Main Building, designed by Patton & Fisher and constructed 1891-1893, and the other buildings on Federal Street (looking... Show morePhotograph of the Main Building, designed by Patton & Fisher and constructed 1891-1893, and the other buildings on Federal Street (looking south). Photograph appears on page 33 of the 1906 Integral, the Armour Institute of Technology Yearbook. Photographer unknown. Show less
Photograph of the Armour Institute of Technology campus, including Main Building, Machinery Hall, Armour Mission, Armour Flats, and Ogden... Show morePhotograph of the Armour Institute of Technology campus, including Main Building, Machinery Hall, Armour Mission, Armour Flats, and Ogden Field. Photographer unknown. Date of photograph is unknown. Date range listed is approximate. Show less
Photograph of a School of Design in Chicago exhibit identified only as "Exhibit B," likely held at the school's 247 East Ontario Street... Show morePhotograph of a School of Design in Chicago exhibit identified only as "Exhibit B," likely held at the school's 247 East Ontario Street location. The photograph shows what appear to be camouflage experiments or exercises by students and an object labeled "texture chart" at right. Photographer unknown. Date of photograph unknown. Date range listed is approximate. Show less
Photograph of a School of Design in Chicago exhibit identified only as "Exhibit B," likely held at the school's 247 East Ontario Street... Show morePhotograph of a School of Design in Chicago exhibit identified only as "Exhibit B," likely held at the school's 247 East Ontario Street location. Text from attached caption: "Experiments in camouflage. A special course given during World War II by the Institute in collaboration with the Office of Civilian Defense." Photographer unknown. Date of photograph unknown. Date range listed is approximate. Show less
Photograph of the Armor Research Foundation's Antarctic Snow Cruiser on a crowded street (location unknown) during the trip between Chicago... Show morePhotograph of the Armor Research Foundation's Antarctic Snow Cruiser on a crowded street (location unknown) during the trip between Chicago and the Boston Army Wharf, the Snow Cruiser's departure point for Antarctica. The Snow Cruiser was designed by Armor Research Foundation Scientific Director Thomas C. Poulter, constructed by ARF, and taken on Richard Byrd's third Antarctic expedition. This photograph originally appeared in the December 1939 issue of the Armor Engineer and Alumnus. Photographer unknown. Show less
Photograph of the Armor Research Foundation's Antarctic Snow Cruiser on the Cherry Valley Turnpike east of Cazenovia, New York, during the... Show morePhotograph of the Armor Research Foundation's Antarctic Snow Cruiser on the Cherry Valley Turnpike east of Cazenovia, New York, during the trip between Chicago and the Boston Army Wharf, the Snow Cruiser's departure point for Antarctica. The Snow Cruiser was designed by Armor Research Foundation Scientific Director Thomas C. Poulter, constructed by ARF, and taken on Richard Byrd's third Antarctic expedition. This photograph originally appeared as part of an advertisement for Economy Fuse and Manufacturing Co. in the December 1939 issue of the Armor Engineer and Alumnus. Photographer unknown. Show less
This paper closely examines HMMs in which all the hidden random variables are... Show moreThis paper closely examines HMMs in which all the hidden random variables are
binary. Its main contributions are (1) a birational parametrization for every such HMM, with an
explicit inverse for recovering the hidden parameters in terms of observables, (2) a semialgebraic
model membership test for every such HMM, and (3) minimal dening equations for the 4-node
fully binary model, comprising 21 quadrics and 29 cubics, which were computed using Grobner
bases in the cumulant coordinates of Sturmfels and Zwiernik. The new model parameters in (1) are
rationally identiable in the sense of Sullivant, Garcia-Puente, and Spielvogel, and each model's
Zariski closure is therefore a rational projective variety of dimension 5. Grobner basis computations
for the model and its graph are found to be considerably faster using these parameters. In the
case of two hidden states, item (2) supersedes a previous algorithm of Schonhuth which is only
generically dened, and the dening equations (3) yield new invariants for HMMs of all lengths
4. Such invariants have been used successfully in model selection problems in phylogenetics, and
one can hope for similar applications in the case of HMMs. Show less
The motivation for this paper is the geometric approach to statistical learning Bayesiannetwork (BN) structures. We review three vector... Show moreThe motivation for this paper is the geometric approach to statistical learning Bayesiannetwork (BN) structures. We review three vector encodings of BN structures. The first one has been used by Jaakkola et al. [9] and also by Cussens [4], the other two use special integral vectors formerly introduced, called imsets [18, 20]. The topic is the comparison of outer polyhedral approximations of the corresponding polytopes. We show how to transform the inequalities suggested by Jaakkola et al. [9] into the framework of imsets. The result of our comparison is the observation that the implicit polyhedral approximation of the standard imset polytope suggested in [21] gives a tighter approximation than the (transformed) explicit polyhedral approximation from [9]. As a consequence, we confirm a conjecture from [21] that the above-mentioned implicit polyhedral approximation of the standard imset polytope is an LP relaxation of that polytope. In the end, we review recent attempts to apply the methods of integer programming to learning BN structures and discuss the task of finding suitable explicit LP relaxation in the imset-based approach. Show less