Improving Rewriting Induction Approach for Proving Ground Confluence

In (Aoto&Toyama, FSCD 2016), a method to prove ground confluence of many-sorted term rewriting systems based on rewriting induction is given. In this paper, we give several methods that add wider flexibility to the rewriting induction approach for proving ground confluence. Firstly, we give a method to deal with the case in which suitable rules are not presented in the input system. Our idea is to construct additional rewrite rules that supplement or replace existing rules in order to obtain a set of rules that is adequate for applying rewriting induction. Secondly, we give a method to deal with non-orientable constructor rules. This is accomplished by extending the inference system of rewriting induction and giving a sufficient criterion for the correctness of the system. Thirdly, we give a method to deal with disproving ground confluence. The presented methods are implemented in our ground confluence prover AGCP and experiments are reported. Our experiments reveal the presented methods are effective to deal with problems for which state-of-the-art ground confluence provers can not handle

Synthesis of Dinaphtho[2,3-d:2',3'-d']anthra[1,2-b:5,6-b']dithiophene (DNADT) Derivatives: Effect of Alkyl Chains on Transistor Properties

To investigate organic field-effect transistor (OFET) properties, a new thienoacene-type molecule, 4,14-dihexyldinaphtho[2,3-d:2',3'-d']anthra[1,2-b:5,6-b']dithiophene (C6-DNADT), consisting of pi-conjugated nine aromatic rings and two hexyl chains along the longitudinal molecular axis has been successfully synthesized by sequential reactions, including Negishi coupling, epoxidation, and cycloaromatization. The fabricated OFET using thin films of C6-DNADT exhibited p-channel FET properties with field-effect mobilities (mu) of up to 2.6 x 10(-2) cm(2) V-1 s(-1), which is ca. three times lower than that of the parent DNADT molecule (8.5 x 10(-2) cm(2) V-1 s(-1)). Although this result implies that the installation of relatively short alkyl chains into the DNADT core is not suitable for transistor application, the origins for the FET performance obtained in this work is fully discussed, based on theoretical calculations and solid-state structure of C6-DNADT by grazing incidence wide-angle X-ray scattering (GIWAXS) and atomic force microscopy (AFM) analyses. The results obtained in this study disclose the effect of alkyl chains introduced onto the molecule on transistor characteristics

Effects of a Domestic Merger on Exports : The Case Study of a Merger of Korean Automakers in 1998

本稿では，1998年韓国での現代自動車と起亜自動車の水平合併を定量的に評価する．合併によって生じたであろう競争制限効果及び効率性向上効果を勘案した上で，現代・起亜自動車合併が韓国の国内市場及び輸出市場に与えた影響を経済厚生の観点から分析する．車種レベルの市場データを使って構造推定を行なったところ，本合併によって現代・起亜自動車における車種別の限界費用は8.4％低下したことが分かった．推定結果を踏まえたシミュレーション分析の結果，当該合併は韓国の国内価格に平均わずか1％未満の上昇しかもたらさなかったのに対し，韓国からの輸出は合併によって倍以上に拡大したことが明らかになった．しかし，この合併が与えた影響は車種によって一様ではなく，国内価格について大型車は約0.3％下がったものの，国内販売台数シェアでほぼ7 割を占める軽・小・中型車は2％上がっている．車種による合併の影響の違いは，韓国自動車市場における輸出の経済メカニズムに深く関係しており，当該合併による効率性向上効果が軽・小型車では輸出増にのみに影響を与えたのに対し，大型車については輸出増と国内価格の下落の双方を促したことが分かった．当該合併によって，韓国における社会厚生は約9％上昇し，そのうち輸出から得られた企業利潤の増加は8 割以上を占めると推定された．現代・起亜自動車の企業結合事案の定量分析を通じて，一定の取引分野における競争を実質的に制限する場合であっても，企業結合の効率性向上効果が輸出の活性化を通じて消費者厚生の減少分を上回る社会厚生増を生み出し得ることが分かった．この論点は本稿が企業の輸出行動を分析して初めて明らかになった点であり，国内産業の合理化・集約化とともに「国際競争力」の強化が喫緊の課題となっているわが国において，現行の企業結合規制が持つ限界を示唆するものとなっている．論文/Articl

Neighborhood environmental factors and physical activity status among rural older adults in Japan

(1) Background: Although several neighborhood environmental factors have been identified to be associated with older adults’ physical activity, little research has been done in rural areas where the population is aging. This study aimed to investigate neighborhood environmental factors and the longitudinal change of physical activity status among rural older adults in Japan. (2) Meth-ods: The study included 2211 older adults, aged over 60 years, residing in three municipalities in Shimane prefecture and participating at least twice in annual health checkups between 2010 and 2019. Physical activity was identified based on self-report. Hilliness, bus stop density, intersection density, residential density, and distance to a community center were calculated for each subject. Hazard ratios for the incidence of physical inactivity were estimated using Cox proportional hazards models. (3) Results: We found that 994 (45%) of the study subjects became physically inactive during the follow-up. Those living far from a community center had a lower risk of becoming physically inactive compared to those living close to a community center. When the analysis was stratified by residential municipality, this association remained in Ohnan town. Those living in hilly areas had a higher risk of becoming physically inactive in Okinoshima town. (4) Conclusions: The impact of neighborhood environmental factors on older adults’ physical activity status might differ by region possibly due to different terrain and local lifestyles

Social participation and physical prefrailty in older Japanese adults: The Shimane CoHRE study.

As older adults in an early stage (prefrailty) of frailty may return to a healthy state, it is necessary to examine the prevention of prefrailty. In this context, the number and types of social participation activities associated with physical prefrailty in community-dwelling older adults have remained relatively unexplored. This cross-sectional study investigates this issue by analyzing 616 participants living in Okinoshima, Shimane, a rural area of Japan, in 2019. Frailty was assessed using the 5-item frailty phenotype (unintentional weight loss, self-reported exhaustion, weakness, slow walking speed, and low physical activity). Data on social participation were obtained using a questionnaire based on participants' level of involvement with volunteer groups, sports clubs/groups, neighborhood associations, religious organizations/groups, and community elderly salons; their answers were categorized as "yes" if they answered "several times per year or more" and "no" if they answered "never." Binominal logistic regression was used to estimate odds ratios (OR) and 95% confidence intervals (CI) of prefrailty by the number or types of social participation activities, adjusted for gender, age, body mass index, smoking, medication-taking, educational attainment, working status, and living arrangement. Of the 616 participants, 273 (44.3%) and 28 (4.5%) had prefrailty and frailty, respectively. The analysis showed that the number of social participation activities was significantly associated with lower odds of prefrailty (OR = 0.83; 95% CI, 0.74-0.94). Regarding the types of social participation, sports clubs/groups were associated with lower odds of prefrailty (OR = 0.47; 95% CI, 0.31-0.73). Participation in neighborhood associations was associated with prefrailty/frailty (OR = 0.57; 95% CI, 0.37-0.86). These results suggest that increasing the number of social participation activities or involvement in sports clubs/groups and neighborhood associations may be important to prevent physical prefrailty in the older population