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Optimization of energy saving device combined with a propeller using real-coded genetic algorithm
Ryu, Tomohiro,Kanemaru, Takashi,Kataoka, Shiro,Arihama, Kiyoshi,Yoshitake, Akira,Arakawa, Daijiro,Ando, Jun The Society of Naval Architects of Korea 2014 International Journal of Naval Architecture and Oc Vol.6 No.2
This paper presents a numerical optimization method to improve the performance of the propeller with Turbo-Ring using real-coded genetic algorithm. In the presented method, Unimodal Normal Distribution Crossover (UNDX) and Minimal Generation Gap (MGG) model are used as crossover operator and generation-alternation model, respectively. Propeller characteristics are evaluated by a simple surface panel method "SQCM" in the optimization process. Blade sections of the original Turbo-Ring and propeller are replaced by the NACA66 a = 0.8 section. However, original chord, skew, rake and maximum blade thickness distributions in the radial direction are unchanged. Pitch and maximum camber distributions in the radial direction are selected as the design variables. Optimization is conducted to maximize the efficiency of the propeller with Turbo-Ring. The experimental result shows that the efficiency of the optimized propeller with Turbo-Ring is higher than that of the original propeller with Turbo-Ring.
Optimization of energy saving device combined with a propeller using real-coded genetic algorithm
Tomohiro Ryu,Takashi Kanemaru,Shiro Kataoka,Kiyoshi Arihama,Akira Yoshitake,Daijiro Arakawa,Jun Ando 대한조선학회 2014 International Journal of Naval Architecture and Oc Vol.6 No.2
This paper presents a numerical optimization method to improve the performance of the propeller with Turbo-Ring using real-coded genetic algorithm. In the presented method, Unimodal Normal Distribution Crossover (UNDX) and Minimal Generation Gap (MGG) model are used as crossover operator and generation-alternation model, respectively. Propeller characteristics are evaluated by a simple surface panel method “SQCM” in the optimization process. Blade sections of the original Turbo-Ring and propeller are replaced by the NACA66 a = 0.8 section. However, original chord, skew, rake and maximum blade thickness distributions in the radial direction are unchanged. Pitch and maximum camber distributions in the radial direction are selected as the design variables. Optimization is conducted to maximize the efficiency of the propeller with Turbo-Ring. The experimental result shows that the efficiency of the opti-mized propeller with Turbo-Ring is higher than that of the original propeller with Turbo-Ring.
Fumiaki Ishibashi,Konomi Kobayashi,Keita Fukushima,Ryu Tanaka,Tomohiro Kawakami,Junko Kato,Kazuaki Sugihara 대한소화기내시경학회 2020 Clinical Endoscopy Vol.53 No.6
Background/Aims: While Helicobacter pylori (HP)-negative gastric cancer is frequently reported, little is known about the predictors for detecting HP-negative early gastric cancer (EGC). We aimed to evaluate the predictors for the detection of HP-negative EGC. Methods: We retrospectively reviewed 13,477 consecutive asymptomatic cases where upper endoscopy was performed by nine physicians from April 2017 to March 2019 and analyzed the detection rate of high-risk lesions (HRLs), including EGC, tubular adenoma, and lymphoma, according to the status of HP infection. The observation time was corrected for multiple regression analyses. Results: For all physicians, the average observation time for screening HP-eradicated and -naïve patients was shorter than that for screening HP-positive patients (p<0.05). Multiple regression analyses revealed that the observation time in the three groups was an independent predictor for detecting HRLs in HP-eradicated patients (p=0.03106, 0.01263, and 0.02485, respectively), while experience of endoscopy was an independent predictor for detecting HRLs in HP-naïve patients (p=0.02638). Conclusions: While observation time during screening endoscopy was a quality indicator for detecting HRLs in HP-eradicated patients, experience of endoscopy was a quality indicator for detecting HRLs in HP-naïve patients.