This paper proposes an improved optimal operation planning method for residential PEFC-CGS (Polymer Electrolyte Fuel CellCo-Generation System). Residential PEFC-CGS has recently been gathering attention as one of the ...This paper proposes an improved optimal operation planning method for residential PEFC-CGS (Polymer Electrolyte Fuel CellCo-Generation System). Residential PEFC-CGS has recently been gathering attention as one of the distributed power sources with high efficiency and low environmental impacts. Previous research pointed out that the output variations of PEFC adversely affect the durability. It can be surmised that smaller output variations will be desired to extend durability years. However, in this field, ramping rate have not been sufficiently considered. For local search and tabu search, ramping rate constraint makes our operation planning difficult because it restricts the search for feasible neighborhood solutions. Therefore, the authors proposed a method to deal with typical and harsher ramping rate constraints in comparison with conventional methods. There are two key points for the improvement. One is the reinforcement of the search along the output power axis;the other is to make use of the strategy of tabu search which avoids the local optimal solutions. The simulation results show the effectiveness of the proposed method in the daily operation planning. Furthermore, in the case using typical ramping rate parameter, it is confirmed that tabu search doesn’t contribute the reduction of daily operational cost due to the above stated restriction of the search area.展开更多
AIM: To investigate the success rate of mini-implants and its characteristics and risk factors by survival analyses. METHODS: Three hundred and ninety-four miniimplants of the same type were placed by a single clinici...AIM: To investigate the success rate of mini-implants and its characteristics and risk factors by survival analyses. METHODS: Three hundred and ninety-four miniimplants of the same type were placed by a single clinician. Age, gender, treatment duration, time of failure, side and jaw of implantation and the soft tissue at placement site were recorded. Odds ratio, survival curves, and Cox proportional hazard model were applied to evaluate the factors influencing the miniimplants' success rate. RESULTS: The cumulative success rate was 88.1%.The maxilla had a significantly higher success rate than that of the mandible(91.7% vs 83.7%, respectively, P = 0.019). Placement of mini-implants in the attached gingiva(AG) showed a higher success rate than that of the mucogingival junction(MGJ) and mucous membrane(MM)(AG, 94.3%; MGJ, 85.8%; MM, 79.4%; P < 0.001). Significant association was found between the jaw and the gingival tissue type(P < 0.001). There were no significant differences between maxilla and mandible when compared within each placement site.CONCLUSION: The gingival tissue type had the most significant effect on the success rate of the mini-implant with higher success rate in the attached gingiva.展开更多
To effectively evaluate the fuzziness of the market environment in product planning,a customer requirements analysis method based on multiple preference information is proposed.Firstly,decision-makers use a preferred ...To effectively evaluate the fuzziness of the market environment in product planning,a customer requirements analysis method based on multiple preference information is proposed.Firstly,decision-makers use a preferred information form to evaluate the importance of each customer requirement.Secondly,a transfer function is employed to unify various forms of preference information into a fuzzy complementary judgment matrix.The ranking vector is then calculated using row and normalization methods,and the initial importance of customer requirements is obtained by aggregating the weights of decision members.Finally,the correction coefficients of initial importance and each demand are synthesized,and the importance of customer requirements is determined through normalization.The development example of the PE jaw crusher demonstrates the effectiveness and feasibility of the proposed method.展开更多
文摘This paper proposes an improved optimal operation planning method for residential PEFC-CGS (Polymer Electrolyte Fuel CellCo-Generation System). Residential PEFC-CGS has recently been gathering attention as one of the distributed power sources with high efficiency and low environmental impacts. Previous research pointed out that the output variations of PEFC adversely affect the durability. It can be surmised that smaller output variations will be desired to extend durability years. However, in this field, ramping rate have not been sufficiently considered. For local search and tabu search, ramping rate constraint makes our operation planning difficult because it restricts the search for feasible neighborhood solutions. Therefore, the authors proposed a method to deal with typical and harsher ramping rate constraints in comparison with conventional methods. There are two key points for the improvement. One is the reinforcement of the search along the output power axis;the other is to make use of the strategy of tabu search which avoids the local optimal solutions. The simulation results show the effectiveness of the proposed method in the daily operation planning. Furthermore, in the case using typical ramping rate parameter, it is confirmed that tabu search doesn’t contribute the reduction of daily operational cost due to the above stated restriction of the search area.
文摘AIM: To investigate the success rate of mini-implants and its characteristics and risk factors by survival analyses. METHODS: Three hundred and ninety-four miniimplants of the same type were placed by a single clinician. Age, gender, treatment duration, time of failure, side and jaw of implantation and the soft tissue at placement site were recorded. Odds ratio, survival curves, and Cox proportional hazard model were applied to evaluate the factors influencing the miniimplants' success rate. RESULTS: The cumulative success rate was 88.1%.The maxilla had a significantly higher success rate than that of the mandible(91.7% vs 83.7%, respectively, P = 0.019). Placement of mini-implants in the attached gingiva(AG) showed a higher success rate than that of the mucogingival junction(MGJ) and mucous membrane(MM)(AG, 94.3%; MGJ, 85.8%; MM, 79.4%; P < 0.001). Significant association was found between the jaw and the gingival tissue type(P < 0.001). There were no significant differences between maxilla and mandible when compared within each placement site.CONCLUSION: The gingival tissue type had the most significant effect on the success rate of the mini-implant with higher success rate in the attached gingiva.
文摘To effectively evaluate the fuzziness of the market environment in product planning,a customer requirements analysis method based on multiple preference information is proposed.Firstly,decision-makers use a preferred information form to evaluate the importance of each customer requirement.Secondly,a transfer function is employed to unify various forms of preference information into a fuzzy complementary judgment matrix.The ranking vector is then calculated using row and normalization methods,and the initial importance of customer requirements is obtained by aggregating the weights of decision members.Finally,the correction coefficients of initial importance and each demand are synthesized,and the importance of customer requirements is determined through normalization.The development example of the PE jaw crusher demonstrates the effectiveness and feasibility of the proposed method.
