Efficiencies of Quantum Optical Detectors

We propose a definition for the efficiency that can be universally applied to all classes of quantum optical detectors. This definition is based on the maximum amount of optical loss that a physically plausible device can experience while still replicating the properties of a given detector. We prove that detector efficiency cannot be increased using linear optical processing. That is, given a set of detectors, as well as arbitrary linear optical elements and ancillary light sources, it is impossible to construct detection devices that would exhibit higher efficiencies than the initial set.Comment: 5 pages, 3 figure

Do Teachers’ Race, Gender, and Ethnicity Matter? Evidence From the National Education Longitudinal Study of 1988

Using data from the National Educational Longitudinal Study of 1988 (NELS), the authors find that the match between teachers\u27 race, gender, and ethnicity and those of their students had little association with how much the students learned, but in several instances it seems to have been a significant determinant of teachers\u27 subjective evaluations of their students. For example, test scores of white female students in mathematics and science did not increase more rapidly when the teacher was a white woman than when the teacher was a white man, but white female teachers evaluated their white female students more highly than did white male teachers

Do Teachers' Race, Gender, and Ethnicity Matter?: Evidence from NELS88

Our study uses a unique national longitudinal survey, the National Educational Longitudinal Study of 1988 (NELS), which permits researchers to match individual students and teachers, to analyze issues relating to how a teacher's race, gender, and ethnicity, per se, influence students from both the same and different race, gender, and ethnic groups. In contrast to much of the previous literature, we focus both on how teachers subjectively relate to and evaluate their students and on objectively how much their students learn. On balance, we find that teachers' race, gender, and ethnicity, per se, are much more likely to influence teachers' subjective evaluations of their students than they are to influence how much the students objectively learn. For example, while white female teachers do not appear to be associated with larger increases in test scores for white female students in mathematics and science than white male teachers 'produce', white female teachers do have higher subjective evaluations than their white male counterparts of their white female students. We relate our findings to the more general literature on gender, race, and ethnic bias in subjective performance evaluations in the world of work and trace their implications for educational and labor markets.

Functional Ownership through Fractional Uniqueness

Ownership and borrowing systems, designed to enforce safe memory management without the need for garbage collection, have been brought to the fore by the Rust programming language. Rust also aims to bring some guarantees offered by functional programming into the realm of performant systems code, but the type system is largely separate from the ownership model, with type and borrow checking happening in separate compilation phases. Recent models such as RustBelt and Oxide aim to formalise Rust in depth, but there is less focus on integrating the basic ideas into more traditional type systems. An approach designed to expose an essential core for ownership and borrowing would open the door for functional languages to borrow concepts found in Rust and other ownership frameworks, so that more programmers can enjoy their benefits. One strategy for managing memory in a functional setting is through uniqueness types, but these offer a coarse-grained view: either a value has exactly one reference, and can be mutated safely, or it cannot, since other references may exist. Recent work demonstrates that linear and uniqueness types can be combined in a single system to offer restrictions on program behaviour and guarantees about memory usage. We develop this connection further, showing that just as graded type systems like those of Granule and Idris generalise linearity, Rust's ownership model arises as a graded generalisation of uniqueness. We combine fractional permissions with grading to give the first account of ownership and borrowing that smoothly integrates into a standard type system alongside linearity and graded types, and extend Granule accordingly with these ideas.Comment: 23 pages + references. In submissio

Lector Intende, Laetaberis: A Research-Based Approach to Introductory Latin

In the 2019-20 academic year, we undertook a full redesign of our introductory Latin curriculum at the College of the Holy Cross in order to provide students with a more meaningful encounter with the Latin language. We primed our students to work with real, unedited Latin texts within their first year of study by highlighting Latin grammatical concepts that were frequent, complex, and unfamiliar to English speakers, which meant introducing topics like the passive voice, the subjunctive, third-declension adjectives, and indirect statement that are foundational to the Latin language much earlier than we had previously

Graded Modal Types for Integrity and Confidentiality

Graded type systems, such as the one underlying the Granule programming language, allow various different properties of a program's behaviour to be tracked via annotating types with additional information, which we call grades. One example of such a property, often used as a case study in prior work on graded types, is information flow control, in which types are graded by a lattice of security levels allowing noninterference properties to be automatically verified and enforced. These typically focus on one particular aspect of security, however, known as confidentiality; public outputs are prohibited from depending on private inputs. Integrity, a property specifying that trusted outputs must not depend on untrusted inputs, has not been examined in this context. This short paper aims to remedy this omission. It is well-known that confidentiality and integrity are in some sense dual properties, but simply reversing the ordering of the security lattice turns out to be unsatisfactory for the purpose of combining both kinds of property in a single system, at least in our setting. We analogize the situation to recent work on embedding both linear and uniqueness types in a graded framework, and use this framing to demonstrate that we can enforce both integrity and confidentiality alongside one another. The main idea is to add an additional flavour of modality annotated for integrity, such that the existing graded comonad for tracking confidentiality now also acts as a relative monad over the new modality, with rules allowing information to flow from trusted to public to private.Comment: 3 pages. Originally presented as a short paper at PLAS 202