Power Distribution Network Problem (PDNP) can be generally defined as determining the configuration of power distribution network. Power Distribution Network Reconfiguration Problem (PDNRP) can be defined as, for a given PDNP instance and two feasible configurations, determining the reachability from one configuration to another one while satisfying the transition constraints. This paper focuses on searching the shortest path of PDNRPs. In this paper, we propose an approach to solving PDNPs and PDNRPs based on Answer Set Programming (ASP). In our approach, at first, a problem instance is converted into a set of ASP facts. Then, the facts combined with ASP encoding for PDNP/PDNRP solving can be solved by using ASP systems, in our case clingo. To evaluate the effectiveness of our approach, we conduct experiments using benchmark sets including a practical PDNP instance called fukui-tepco.

Algebraic effects and handlers, which abstract effect occurrences in programs and define their behaviors in the handlers, enable programmers to clearly write effectful programs thanks to the separation of effect implementations. Trace effects, which statically estimate the order of events occurring during program executions, enable temporal property verification of programs. In this paper, we propose a type-and-effect system where algebraic effect handlers and trace effects coexist, with which we can capture temporal properties of the program while enjoying the ability of algebraic effect handlers to separate effect implementations. Also, we show the type safety of the type-and-effect system, which states that evaluations of well-typed terms do not get stuck and that trace effects of terms derived by the type-checking conservatively estimate event traces which possibly occur during the evaluations of the terms. We also construct a sound type inference algorithm for the proposed system.

A language L is said to be regular-measurable if there exists an infinite sequence of pairs of regular languages that “converges” to L. Instead of regular languages, this paper examines measuring power of several fragments of regular languages: piecewise testable (PT) and alphabet testable (AT) languages. In particular, we showed that, while AT-measurability for regular languages is co-NP complete, PT-measurability is decidable in linear time.

We conducted a survey on program synthesis techniques that automatically generate programs from specification information. Full papers from 2016 to 2020 of major conferences in the fields of software engineering, programming languages, artificial intelligence and natural language processing were covered and categorized by methods and application domains. This paper provides a bird's eye view of the trends in program synthesis techniques in the last five years.

We propose a method and workflow for producing various sensors and electrical circuits for interactive devices by partially carbonizing the wood surface with a laser cutting machine. Similar to wiring on a conventional printed circuit board (PCB), the carbonized part functions as a conductive electrical path. A method for creating electronic circuits and sensors made of carbon graphene has been proposed. This technique makes use of a raster-scanning femtosecond (fs) laser, which is less common for personal fabrication than a constant-wave (CW) laser. Moreover, raster-scanning requires a substantial amount of time to create a circuit that is mainly made of conductive lines. This paper extends the method with a defocused vector-scanning CW laser beam and reduces the time and cost required for fabrication. The proposed method uses an affordable CW laser cutter to fabricate a circuit, including touch sensors, damage sensors, and load sensors on wood boards. The circuit can be easily connected to conventional PCBs and electric parts such as one-board microcomputers using metal screws and nails typically used in DIY woodworking.

To understand why features of existing software can depend on each other is important for correct addition of a new feature to the software. Although some work has been done to detect feature dependency, it is not clear how effective such existing approaches are when they are applied to feature dependency comprehension because they are aimed at detection of runtime dependency between features. Therefore in this thesis, the author presents an extraction method of source code that can be used to comprehend feature dependency. The method can extract a wider range of source code than existing techniques of feature dependency detection by using delta extraction. The author conducted a controlled experiment with 20 professional Java programmers and confirmed that the source code extracted by our method is more effective for feature dependency comprehension than exsiting method. To figure out an internal mechanism to enable feature dependency, the author also defined semi-static parts of object graphs that can be used to make features depend on each other. Finally, the author confirmed that semi-static structures are actually used in feature dependencies in three open-source programs and can be effectively extracted by our method.