arXiv subjects

Hidetake Tanaka

Publications and source records attributed to Hidetake Tanaka.

6 recordsLinked to original sources

arXiv2026

Practical Implementation Report on Introducing Spec-Driven Development Using AI Agents in Software Development PBL

In recent years, autonomous AI agents such as GitHub Copilot and Claude Code have been rapidly gaining popularity. This study reports on the practical implementation of Spec-Driven Development, a software development methodology premised on AI agents, within a Software Development Project-Based Learning (SDPBL) course for third-year undergraduate students. We defined a workflow consisting of four phases, namely investigation, planning, implementation, and review. We also established an environment tailored for the SDPBL course where AI agents generate documentation and code during each phase. We analyzed the results from three perspectives, namely students' subjective AI usage, implementation throughput, and code comprehension. The analysis reveals that AI usage patterns varied across development phases and teams. Moreover, while AI agent utilization increased implementation throughput, it also tended to encourage students to proceed with development without fully understanding the code. This study demonstrates that regular verification of code comprehension by instructors and appropriate feedback are essential for maintaining educational effectiveness when introducing SDD into SDPBL.

cs.SE↗

arXiv2026

A Longitudinal Analysis of Good First Issue Practices and Newcomer Pull Requests in Popular OSS Projects

Open-source software (OSS) projects rely on effective newcomer onboarding to sustain their communities. OSS projects widely adopt "good first issue" (GFI) labels to highlight beginner-friendly tasks. As development practices continue to evolve, understanding how these onboarding mechanisms change over time is important for both maintainers and researchers. This study analyzes 406,826 issues and 1,117 newcomer GFI pull requests across 37 popular GitHub repositories (30 of which use GFI labels) over a four-year period from July 2021 to June 2025. We find that while the proportion of issues with GFI labels remained stable during the first three years, it underwent a statistically significant decline beginning in January 2024, with substantial variation across projects not explained by repository age or programming language. Despite this supply-side decline, newcomer engagement with GFI issues remains stable at approximately 27%, suggesting that GFI labels maintain consistent attractiveness. Examining the outcomes of this engagement, we find that the merge rate of newcomer GFI pull requests declined from 61.9% to 42.2%. Initial pull request characteristics such as description length and code size show no significant association with merge outcomes, indicating that success is not predicted by the quantitative characteristics of the initial submission alone. Together, these findings reveal a widening gap between stable newcomer interest in GFIs and the declining availability and success of GFI-based onboarding, underscoring the need for maintainers to sustain both GFI labeling and review support.

cs.SE↗

arXiv2026

Why Are Agentic Pull Requests Merged or Rejected? An Empirical Study

AI coding agents increasingly submit pull requests (Agentic-PRs) to open-source repositories, yet their performance is commonly assessed using merge and rejection outcomes alone. We hypothesized that these outcome labels do not reliably reflect agent capability without considering review interactions. To test this, we conducted a decision-oriented analysis of 11,048 closed Agentic Pull Requests, refined to 9,799 human-reviewed PRs, and manually inspected 717 representative cases to recover decision rationale from interaction artifacts. We found that rejection outcomes substantially overstate agent error: only 35.7% of rejected PRs reflected clear agentic failures, while 31.2% were driven by workflow constraints and 33.1% lacked observable decision rationale. Among merged PRs, 15.4% required explicit reviewer involvement through feedback or direct commits, and 5.5% showed no visible interaction trace. We further observed systematic differences across agents, with Copilot and Devin more often embedded in reviewer-mediated workflows, while Codex and Cursor PRs were typically merged with minimal interaction. These results reject the assumption that PR outcomes alone capture agent performance and demonstrate the need for interaction-aware evaluation grounded in review behavior.

cs.SE↗

arXiv2025

Understanding the Characteristics of LLM-Generated Property-Based Tests in Exploring Edge Cases

As Large Language Models (LLMs) increasingly generate code in software development, ensuring the quality of LLM-generated code has become important. Traditional testing approaches using Example-based Testing (EBT) often miss edge cases -- defects that occur at boundary values, special input patterns, or extreme conditions. This research investigates the characteristics of LLM-generated Property-based Testing (PBT) compared to EBT for exploring edge cases. We analyze 16 HumanEval problems where standard solutions failed on extended test cases, generating both PBT and EBT test codes using Claude-4-sonnet. Our experimental results reveal that while each method individually achieved a 68.75\% bug detection rate, combining both approaches improved detection to 81.25\%. The analysis demonstrates complementary characteristics: PBT effectively detects performance issues and edge cases through extensive input space exploration, while EBT effectively detects specific boundary conditions and special patterns. These findings suggest that a hybrid approach leveraging both testing methods can improve the reliability of LLM-generated code, providing guidance for test generation strategies in LLM-based code generation.

cs.SE↗

arXiv2025

Mining for Lags in Updating Critical Security Threats: A Case Study of Log4j Library

The Log4j-Core vulnerability, known as Log4Shell, exposed significant challenges to dependency management in software ecosystems. When a critical vulnerability is disclosed, it is imperative that dependent packages quickly adopt patched versions to mitigate risks. However, delays in applying these updates can leave client systems exposed to exploitation. Previous research has primarily focused on NPM, but there is a need for similar analysis in other ecosystems, such as Maven. Leveraging the 2025 mining challenge dataset of Java dependencies, we identify factors influencing update lags and categorize them based on version classification (major, minor, patch release cycles). Results show that lags exist, but projects with higher release cycle rates tend to address severe security issues more swiftly. In addition, over half of vulnerability fixes are implemented through patch updates, highlighting the critical role of incremental changes in maintaining software security. Our findings confirm that these lags also appear in the Maven ecosystem, even when migrating away from severe threats.

cs.SE↗

arXiv2019

Synthesis of anti-perovskite-type carbides and nitrides from metal oxides and melamine

Four anti-perovskite-type compounds, ZnNNi3, ZnCNi3, SnNCo3, and SnCCo3, are synthesised through reactions between ingredient metal oxides and organic compound melamine (C3H6N6). ZnNNi3 and ZnCNi3 are selectively synthesised by choosing different reaction temperatures and nominal oxide-to-melamine ratios. SnNCo3 is synthesised for the first time by this melamine method. Resistivity, magnetisation, and heat capacity measurements reveal that SnNCo3 is a correlated metal with a high density of states at the Fermi level. Our results demonstrate that this feasible synthetic route using melamine is useful in the search for complex metal carbides and nitrides toward novel functional materials.

cond-mat.mtrl-sci↗