A fast algorithm for translating combinator expressions with BC-chains

A fast algorithm is presented for translating lambda expressions to combinator trees with BC-chains. The time complexity of this algorithm is O (n log n) in the worst case, where n is the length of an input expression. Furthermore it requires only O (n log n) working space. This result achieves a substantial improvement to the previously known algorithm having the quadratic complexity. The basic idea of the algorithm may be applied to practical processing systems, whether they use BC-chains or not.     

Linearity and bisimulation

Exploiting linear type structure, we introduce a new theory of weak bisimilarity for the π-calculus in which we abstract away not only τ-actions but also non-τ actions which do not affect well-typed observers. This gives a congruence far larger than the standard bisimilarity while retaining semantic soundness. The framework is smoothly extendible to other settings involving nondeterminism and state. As an application we develop a behavioural theory of secrecy in the π-calculus which ensures secure information flow for a strictly greater set of processes than the type-based approach, while still offering compositional verification techniques.     

EFFECTIVENESS OF INFORMATION ENTROPY FOR EVALUATION OF GRINDING EFFICIENCY

From the viewpoint of information theory, the necessity that the under size material distribution follows the exponential law is discussed and the effect of differences in the initial particle-size of the material on the energy necessary to grind is examined

It is confirmed that the concept of information entropy is useful not only to discuss the grinding efficiency by experiments but also to make clear that the energy necessary to grind is smaller as the initial particle-size of the material becomes larger. This method becomes even more useful if the amount of surface area increased is considered as well.     

On the expected behaviors of the Dijkstra's shortest path algorithm for complete graphs

Shortest path, shortest spanning tree, complete graph, number of comparisons, expected complexity     

A new ship's auto pilot design through a stochastic model

A new type of ship's autopilot system is designed by a statistical approach. A ship's motion at sea is described by a multi-variable autoregressive model using minimum AIC (Akaike's Information Criterion) procedure. Through the fitted model, the ship's behavior is analyzed and an optimal control law for a ship under a newly introduced criterion function is derived. The feasibility of our control system is checked by both digital and hybrid simulations. The results of the simulation show that with our controller the yaw motion is depressed through smoother and less rudder motion than that of the conventional autopilot systems and the ill effect of rolling is avoided. It is expected that the controller has another merit: it is quite robust for possible changes of external environments. Finally, a successful result of an actual sea test is briefly discussed. Thus, the possibility of realizing an entirely new autopilot system by a stochastic model is demonstrated.     

Syntheses of functional condensation polymers. II. A polyamide having epoxy groups and its ring-opening derivatives

Polyamides having epoxy groups and their ring-opening derivatives were prepared and characterized, and some of their properties were investigated. Reaction conditions for the low-temperature polycondensation of cis-2,3-epoxysuccinyl chloride (ESC) with aromatic diamines and the interfacial copolycondensation of ESC and adipyl chloride (AC) with aromatic diamines were established to obtain a high molecular weight polyamide having epoxy groups. In addition, the ring-opening reactions of the epoxy groups in the polyamides were carried out with various amines in order to obtain polyamides having hydrophilic pendent groups such as amino and hydroxyl. It was found that the polyamides prepared by ring-opening reaction of the epoxy group with ethylenediamine (EDA) or ethanolamine (EA) had a higher affinity for moisture than those with hexamethylenediamine (HMD) or n-butylamine (n-BA), which might be ascribed to the distance of hydrophilic groups from the polyamide chain. Those polyamides having hydrophilic pendent groups decomposed upon heating at less than 200°C.     

Designed RNAs with Two Peptide‐Binding Units as Artificial Templates for Native Chemical Ligation of RNA‐Binding Peptides

The template effect plays important roles not only in modern synthetic and enzymatic catalysis but also in the ancient “RNA‐polypeptide (RNP) world,” which has been postulated to be a crucial stage in the origin of life. To mimic primitive template catalysis of peptide ligations by RNAs, we previously reported the design and synthesis of a ternary RNP complex in which the ligation of two peptides was significantly facilitated by a template RNA with two peptide‐binding units. However, RNA molecules also promoted the ligation reaction in a nonspecific manner through electrostatic interactions between RNA and basic peptides. In this study, we suppressed this effect by reducing the length of the original template derived from the Tetrahymena intron RNA. This modification, however, decreased the template ability for the specific reaction. As an alternative RNA that was as effective as the original template, we found that a self‐dimerizing RNA was a promising template for peptide ligation without a nonspecific effect.     

Low Capture Switching Activity Test Generation for Reducing IR-Drop in At-Speed Scan Testing

At-speed scan testing, based on ATPG and ATE, is indispensable to guarantee timing-related test quality in the DSM era. However, at-speed scan testing may incur yield loss due to excessive IR-drop caused by high test (shift & capture) switching activity. This paper discusses the mechanism of circuit malfunction due to IR-drop, and summarizes general approaches to reducing switching activity, by which highlights the problem of current solutions, i.e. only reducing switching activity for one capture while the widely used at-speed scan testing based on the launch-off-capture scheme uses two captures. This paper then proposes a novel X-filling method, called double-capture (DC) X-filling, for generating test vectors with low and balanced capture switching activity for two captures. Applicable to dynamic & static compaction in any ATPG system, DC X-filling can reduce IR-drop, and thus yield loss, without any circuit/clock modification, timing/circuit overhead, fault coverage loss, and additional design effort.