Fuzzy logic controller adopting unevenly-distributed membership function was presented with the purpose of enhancing performance of the temperature control precision and robustness for the chamber cooling system.Histo...Fuzzy logic controller adopting unevenly-distributed membership function was presented with the purpose of enhancing performance of the temperature control precision and robustness for the chamber cooling system.Histogram equalization and noise detection were performed to modify the evenly-distributed membership functions of error and error change rate into unevenly-distributed membership functions.Then,the experimental results with evenly and unevenly distributed membership functions were compared under the same outside environment conditions.The experimental results show that the steady-state error is reduced around 40% and the noise disturbance is rejected successfully even though noise range is 60% of the control precision range.The control precision is improved by reducing the steady-state error and the robustness is enhanced by rejecting noise disturbance through the fuzzy logic controller with unevenly-distributed membership function.Moreover,the system energy efficiency and lifetime of electronic expansion valve(EEV) installed in chamber cooling system are improved by adopting the unevenly-distributed membership function.展开更多
Two of the most important tasks in coal mines are to improve efficiency and to increase production besides keeping safety constantly in mind.In order to obtain these goals,mine mechanization is required.Mine mechaniza...Two of the most important tasks in coal mines are to improve efficiency and to increase production besides keeping safety constantly in mind.In order to obtain these goals,mine mechanization is required.Mine mechanization needs high levels of investment and should therefore be studied carefully before final decisions about mechanization are made.When analysizing the potential for mechanization the following,rather imprecise,factors should be considered:seam inclination and thickness,geological disturbances,seam floor conditions,roof conditions,water at the working face and the extension of seams.In our study we have used fuzzy logic,membership functions and created fuzzy rule-based methods and to considered the ultimate objective:mechanization of mining.As a case study,the mechanization of the Takht coal seams in Iran was investigated.The results show a high potential for mechanization in most of the Takht coal seams.展开更多
Tradition has been defined as practices brought forward from the past into the present. In the context of enslavement and the cultural dislocation that accompanied it, memory became critical in the recreation of tradi...Tradition has been defined as practices brought forward from the past into the present. In the context of enslavement and the cultural dislocation that accompanied it, memory became critical in the recreation of tradition. Individual memory contributed to the practices that created new traditions to be carried forward by subsequent generations. Archaeological evidence from Clifton Plantation, Bahamas, illustrates how memory and tradition shaped the identities of both enslaver and enslaved, and influenced the construction of an African Bahamian identity in the early nineteenth-century. In their consumer selections, the enslaved people of Clifton were constructing artifact assemblages that reflected their memories of their traditional cultural background. In the process they were creating an Afro-Bahamian aesthetic that would become a tradition for future generations of Bahamians. While the goods were not of their own manufacture, the choices were theirs from the selection available to them. At the same time, those of British heritage were signaling their British identity through their consumer choices. However, Clifton was unusual in being owned by a reformer who sought to ameliorate the conditions of slavery. The paper also briefly discusses whether these concepts are useful in understanding the material culture of enslaved Africans at other sites.展开更多
文摘Fuzzy logic controller adopting unevenly-distributed membership function was presented with the purpose of enhancing performance of the temperature control precision and robustness for the chamber cooling system.Histogram equalization and noise detection were performed to modify the evenly-distributed membership functions of error and error change rate into unevenly-distributed membership functions.Then,the experimental results with evenly and unevenly distributed membership functions were compared under the same outside environment conditions.The experimental results show that the steady-state error is reduced around 40% and the noise disturbance is rejected successfully even though noise range is 60% of the control precision range.The control precision is improved by reducing the steady-state error and the robustness is enhanced by rejecting noise disturbance through the fuzzy logic controller with unevenly-distributed membership function.Moreover,the system energy efficiency and lifetime of electronic expansion valve(EEV) installed in chamber cooling system are improved by adopting the unevenly-distributed membership function.
文摘Two of the most important tasks in coal mines are to improve efficiency and to increase production besides keeping safety constantly in mind.In order to obtain these goals,mine mechanization is required.Mine mechanization needs high levels of investment and should therefore be studied carefully before final decisions about mechanization are made.When analysizing the potential for mechanization the following,rather imprecise,factors should be considered:seam inclination and thickness,geological disturbances,seam floor conditions,roof conditions,water at the working face and the extension of seams.In our study we have used fuzzy logic,membership functions and created fuzzy rule-based methods and to considered the ultimate objective:mechanization of mining.As a case study,the mechanization of the Takht coal seams in Iran was investigated.The results show a high potential for mechanization in most of the Takht coal seams.
文摘Tradition has been defined as practices brought forward from the past into the present. In the context of enslavement and the cultural dislocation that accompanied it, memory became critical in the recreation of tradition. Individual memory contributed to the practices that created new traditions to be carried forward by subsequent generations. Archaeological evidence from Clifton Plantation, Bahamas, illustrates how memory and tradition shaped the identities of both enslaver and enslaved, and influenced the construction of an African Bahamian identity in the early nineteenth-century. In their consumer selections, the enslaved people of Clifton were constructing artifact assemblages that reflected their memories of their traditional cultural background. In the process they were creating an Afro-Bahamian aesthetic that would become a tradition for future generations of Bahamians. While the goods were not of their own manufacture, the choices were theirs from the selection available to them. At the same time, those of British heritage were signaling their British identity through their consumer choices. However, Clifton was unusual in being owned by a reformer who sought to ameliorate the conditions of slavery. The paper also briefly discusses whether these concepts are useful in understanding the material culture of enslaved Africans at other sites.
