Chiba University of Commerce

About: Chiba University of Commerce is a education organization based out in Ichikawa-minami, Japan. It is known for research contribution in the topics: Social media & Marketing buzz. The organization has 74 authors who have published 212 publications receiving 2224 citations.

Language Primitives and Type Discipline for Structured Communication-Based Programming

Abstract: We introduce basic language constructs and a type discipline as a foundation of structured communication-based concurrent programming. The constructs, which are easily translatable into the summation-less asynchronous π-calculus, allow programmers to organise programs as a combination of multiple flows of (possibly unbounded) reciprocal interactions in a simple and elegant way, subsuming the preceding communication primitives such as method invocation and rendez-vous. The resulting syntactic structure is exploited by a type discipline a la ML, which offers a high-level type abstraction of interactive behaviours of programs as well as guaranteeing the compatibility of interaction patterns between processes in a well-typed program. After presenting the formal semantics, the use of language constructs is illustrated through examples, and the basic syntactic results of the type discipline are established. Implementation concerns are also addressed.

A complete terrestrial radiocarbon record for 11.2 to 52.8 kyr B.P

Abstract: Radiocarbon (14C) provides a way to date material that contains carbon with an age up to ~50,000 years and is also an important tracer of the global carbon cycle. However, the lack of a comprehensive record reflecting atmospheric 14C prior to 12.5 thousand years before the present (kyr B.P.) has limited the application of radiocarbon dating of samples from the Last Glacial period. Here, we report 14C results from Lake Suigetsu, Japan (35°35′N, 135°53′E), which provide a comprehensive record of terrestrial radiocarbon to the present limit of the 14C method. The time scale we present in this work allows direct comparison of Lake Suigetsu paleoclimatic data with other terrestrial climatic records and gives information on the connection between global atmospheric and regional marine radiocarbon levels.

Regulation of the monsoon climate by two different orbital rhythms and forcing mechanisms

Abstract: The East Asian monsoon is responsible for transferring huge amounts of heat and moisture between the land and the adjacent ocean. Significant changes in its capacity to do this will have direct impacts on regional climatic gradients and global atmospheric circulation. Determining the mechanisms that force long-term variation in monsoon behavior is therefore important for understanding global climate change. Competing theories vary in the degree of importance attached to glacial forcing, other orbital rhythms, and internal feedback mechanisms as primary drivers of change. There is, however, no convincing explanation as to why different proxy records from closely neighboring regions are tuned to different orbital rhythms. Here we present quantitative climatic reconstructions for the past 450 k.y. based on a long pollen record from Lake Biwa in Japan. The data suggest that continental and oceanic air mass temperatures respond predominantly to the 100 k.y. orbital rhythm, whereas the land-ocean temperature gradient and monsoon vigor oscillate mainly at the 23 k.y. insolation cycle. We suggest that the mechanisms for this behavior lie in the differential response of land and ocean to solar forcing, and conclude that the 100 k.y. signal dominates monsoon intensity only when the amplitude of solar forcing falls below a threshold level.