Is longer unemployment rewarded with longer job tenure?

This paper examines whether or not a prolonged unemployment period can raise the quality of job matching after unemployment. We focus on job tenure as an indicator of a good quality job match after unemployment. We match two sets of Japanese administrative data compiled by the public employment security offices: one includes information about the circumstances of job seekers receiving unemployment insurance, and the other includes information about job seekers applying for jobs. We first show a negative relationship between unemployment duration and the subsequent job duration. Restricting the sample to job seekers who lower their reservation wage in the final 59 days before expiration of unemployment insurance, we secondly show an even greater negative effect of unemployment duration on the following job duration. The importance lies not only in the duration of unemployment. If job seekers keep a high reservation wage because of the benefits of unemployment insurance, and lower it in response to the expiration of insurance, prolonged unemployment will result in short job duration after unemployment.job search, quality of job match, unemployment duration, unemployment insurance

Opto-Acoustic Technique for Residual Stress Analysis

Residual stress analysis based on co-application of acoustic and optical techniques is discussed. Residual stress analysis is a long-standing and challenging problem in many fields of engineering. The fundamental complexity of the problem lies in the fact that a residual stress is locked into the material and therefore hidden inside the specimen. Thus, direct measurement of residual stress in a completely nondestructive fashion is especially difficult. One possible solution is to estimate residual stress from the change in the elastic constant of the material. Residual stress alters the interatomic distance significantly large that the elastic constant is considerably different from the nominal value. From the change in the elastic constant and knowledge of the interatomic potential, it is possible to estimate the residual stress. This acoustic technique (acoustoelasticity) evaluates the elastic modulus of the specimen via acoustic velocity measurement. It is capable of determining the elastic modulus absolutely, but it is a single-point measurement. The optical technique (electronic speckle pattern interferometry, ESPI) yields full-field, two-dimensional strain maps, but it requires an external load to the specimen. Co-application of the two techniques compensates each other’s shortfalls

Duality Cascades and Parallelotopes

Duality cascades are a series of duality transformations in field theories, which can be realized as the Hanany-Witten transitions in brane configurations on a circle. In the setup of the ABJM theory and its generalizations, from the physical requirement that duality cascades always end and the final destination depends only on the initial brane configuration, we propose that the fundamental domain of supersymmetric brane configurations in duality cascades can tile the whole parameter space of relative ranks by translations, hence is a parallelotope. We provide our arguments for the proposal.Comment: 37 pages, 9 eps figures; v2: section 2.2 added, four figures adde

Highly asymmetric probability distribution from a finite-width upward step during inflation

We study a single-field inflation model in which the inflaton potential has an upward step between two slow-roll regimes by taking into account the finite width of the step. We calculate the probability distribution function (PDF) of the curvature perturbation $P[{\cal{R}}]$ using the $\delta N$ formalism. The PDF has an exponential-tail only for positive ${\cal{R}}$ whose slope depends on the step width. We find that the tail may have a significant impact on the estimation of the primordial black hole abundance. We also show that the PDF $P[{\cal{R}}]$ becomes highly asymmetric on a particular scale exiting the horizon before the step, at which the curvature power spectrum has a dip. This asymmetric PDF may leave an interesting signature in the large scale structure such as voids.Comment: 19 pages, 7 figure

A Calculus with Partially Dynamic Records for Typeful Manipulation of JSON Objects

This paper investigates language constructs for high-level and type-safe manipulation of JSON objects in a typed functional language. A major obstacle in representing JSON in a static type system is their heterogeneous nature: in most practical JSON APIs, a JSON array is a heterogeneous list consisting of, for example, objects having common fields and possibly some optional fields. This paper presents a typed calculus that reconciles static typing constraints and heterogeneous JSON arrays based on the idea of partially dynamic records originally proposed and sketched by Buneman and Ohori for complex database object manipulation. Partially dynamic records are dynamically typed records, but some parts of their structures are statically known. This feature enables us to represent JSON objects as typed data structures. The proposed calculus smoothly extends with ML-style pattern matching and record polymorphism. These results yield a typed functional language where the programmer can directly import JSON data as terms having static types, and can manipulate them with the full benefits of static polymorphic type-checking. The proposed calculus has been embodied in SML#, an extension of Standard ML with record polymorphism and other practically useful features. This paper also reports on the details of the implementation and demonstrates its feasibility through examples using actual Web APIs. The SML# version 3.1.0 compiler includes JSON support presented in this paper, and is available from Tohoku University as open-source software under a BSD-style license