- 著者
- Takayuki Miyazaki Yasuhiko Minamide
- 出版者
- Information Processing Society of Japan
- 雑誌
- Journal of Information Processing (ISSN:18826652)
- 巻号頁・発行日
- vol.27, pp.422-430, 2019 (Released:2019-06-15)
- 参考文献数
- 22
- 被引用文献数
- 6
Lookahead is an extension of regular expressions that has been adopted in many implementations and is widely used. Lookahead represents what is allowed as the rest of input. Morihata developed a conversion from regular expressions with lookahead (REwLA) to deterministic finite automata by extending Thompson's construction. In this paper, we develop a conversion from REwLA to deterministic finite automata by extending derivatives of regular expressions. First, we formalize the semantics of REwLA. An REwLA has information about the rest of the input, so the definition of the semantics of REwLA is not languages but structures different from those of regular expressions. Thus, we introduce languages with lookahead as sets of pairs of strings with several operations and define the semantics of REwLA as languages with lookahead. Next, we define two kinds of left quotient for languages with lookahead and give corresponding derivatives. Then, we show that the types of expressions obtained by repeatedly applying derivatives are finite under some equivalence relation and give a conversion to deterministic finite automata. We also show that the semantics of REwLA is a finite union of sets of the form A × B, where A and B are regular languages.
- 著者
- Takayuki Miyazaki Michiyuki Komiyama Naoki Matsumaru Hideki Maeda Katsura Tsukamoto
- 出版者
- The Pharmaceutical Society of Japan
- 雑誌
- Biological and Pharmaceutical Bulletin (ISSN:09186158)
- 巻号頁・発行日
- vol.45, no.4, pp.477-482, 2022-04-01 (Released:2022-04-01)
- 参考文献数
- 20
- 被引用文献数
- 7
Early access to novel drugs, regardless of regional differences, is significant for patients worldwide. Although various efforts have been made to reduce the drug lag, it still exists in some regions, including Japan. In this study, we focused on the drug lag of first-in-class drugs in Japan and obtained fundamental information because we considered that first-in-class and me-too drugs are essentially different and should be treated separately. We analyzed 97 first-in-class and 176 me-too drugs in new molecular entity (NME)-approved drugs in Japan and the United States during the fiscal years between 2009 and 2019. Since government policy and the Evaluation Committee on Unapproved or Off-labeled Drugs with High Medical Needs (the Committee) have a huge impact on drug lag, we distinguished NMEs developed at the Committee’s request. First-in-class drugs were developed at the Committee’s request significantly more than the me-too drugs (p = 0.0034). Although it was not statistically significant, the approval lags were 498.0 d for first-in-class drugs and 535.0 d for me-too drugs. Multiple regression analysis showed that multi-regional clinical trial (MRCT) development strategy (p = 0.0043) and foreign origin drugs (p = 0.0072) were a reducing factor and a prolonging factor of drug lag, respectively. In conclusion, the drug lag for first-in-class drug approval was one year. Global drug development using MRCT is one of the most effective development strategies for reducing drug lags.