以重点工程科技楼建设项目为例,通过建立建筑信息模型(Building Information Modeling,BIM),运用信息增益算法,研究多专业参数化模型构件在常规碰撞及复杂碰撞情况下BIM系统对结果的自决及人工决策情况。通过对算法结果进行分析可知,在...以重点工程科技楼建设项目为例,通过建立建筑信息模型(Building Information Modeling,BIM),运用信息增益算法,研究多专业参数化模型构件在常规碰撞及复杂碰撞情况下BIM系统对结果的自决及人工决策情况。通过对算法结果进行分析可知,在常规三大项碰撞中,BIM对问题的自我决策结果大多可在项目中直接应用,自决率高,总体自决率达到85.71%;在面对复杂碰撞情况中,人工后期干预决策率远高于BIM自决结果,达到了62.5%。两大类碰撞环境与数据特征明显,对利用数字手段指导建筑工程应用难点起到很好的示范指导作用。展开更多
The increasing demand for airline services amidst limited resources results in passenger dissatisfaction and dwindling revenue for airports and airlines. The dynamics of service demand and resource supply results in c...The increasing demand for airline services amidst limited resources results in passenger dissatisfaction and dwindling revenue for airports and airlines. The dynamics of service demand and resource supply results in check-in issues for the stakeholders in the commercial aviation industry. This has the effect of impacting negatively on service performance, cost of operations, customer satisfaction, and overall throughput. Hence, this paper modelled the travelers’ check-in process at the “D Wing” of the Departure Section of Murtala Muhammed International Airport (MMIA), Ikeja, using Arena Software Tool. The work was carried out by determining the parameters of the queues at designated service points in the check-in process. The primary data required to develop the model were acquired by direct observation of passenger flow and oral interview. Thus, the average check-in time was determined. Thereafter, a model of the international check-in system of the MMIA was developed using Arena software in combination with Microsoft Office tools. The data collected were therefore inputted into the model and simulated;the real result was compared with the simulation result of 133 completions and there was no significant difference. The result showed that the model is a representation of the real system under study. Further work will be tailored towards simulation (<em>i.e</em>. the model will be subjected to experimentation in order to have different scenario).展开更多
With the current situation of insecurity in Nigeria and the worsening condition of Nigerian roads, there is increasing demand for air travel. This increasing demand for airline services amidst limited resources result...With the current situation of insecurity in Nigeria and the worsening condition of Nigerian roads, there is increasing demand for air travel. This increasing demand for airline services amidst limited resources results in passenger dissatisfaction and reduction of revenue for airports and airlines. The dynamics of service demand and resource supply result in check-in issues for all the stakeholders in the commercial aviation industry. Hence, this research simulated the developed model for travelers’ check-in process at the “D Wing” of the Departure Section of Murtala Muhammed International Airport (MMIA), Ikeja, using Arena Software Tool. The simulation of the developed model was carried out by varying five different configurations of the servers with respect to the baggage weighing machines and passenger profiling devices to obtain the minimum average check-in time (ACT) for the process, with each configuration undergoing 133 completions of simulation runs. The result of the experimentation revealed that the 3 × 3 × 4 configuration of servers produced the smallest ACT of 18.25 minutes. This translates to a difference of about 58 minutes from the 76.16 minutes ACT of the real system;representing about 76% improvement in the check-in time of passengers. This study contributed to knowledge by revealing that the main choke points in the MMIA check-in system occur at the baggage weighing and passenger profiling areas as against the check-in counter sub-section as advanced by previous works. Furthermore, the research added value to knowledge by creating a balance between customer satisfaction and cost of operations thereby accommodating the interests of the passenger and the operator who are the two main stakeholders in the commercial aviation industry.展开更多
In this paper, we propose a new method to derive a family of regular rate-compatible low-density parity-check（RC-LDPC） convolutional codes from RC-LDPC block codes. In the RC-LDPC convolutional family, each extended...In this paper, we propose a new method to derive a family of regular rate-compatible low-density parity-check（RC-LDPC） convolutional codes from RC-LDPC block codes. In the RC-LDPC convolutional family, each extended sub-matrix of each extended code is obtained by choosing specified elements from two fixed matrices HE1K and HE1K, which are derived by modifying the extended matrices HE1 and HE2 of a systematic RC-LDPC block code. The proposed method which is based on graph extension simplifies the design, and prevent the defects caused by the puncturing method. It can be used to generate both regular and irregular RC-LDPC convolutional codes. All resulted codes in the family are systematic which simplify the encoder structure and have maximum encoding memories which ensure the property. Simulation results show the family collectively offer a steady improvement in performance with code compatibility over binary-input additive white Gaussian noise channel（BI-AWGNC）.展开更多
Objective To study the feasibility of enforcing immunization certificate check before children enroll in primary schools or kindergartens in Guizhou Province. Methods Quantitative and qualitative studies were conducte...Objective To study the feasibility of enforcing immunization certificate check before children enroll in primary schools or kindergartens in Guizhou Province. Methods Quantitative and qualitative studies were conducted. The multi-stage and cluster sampling approach was adopted for the quantitative part of the study. A questionnaire was designed and 996 children and their keepers were interviewed. Principals, doctors or teachers of the primary schools, directors and child care nurses of kindergarten, and staff of immunization agencies were invited to take part in 12 focus group discussions; meanwhile, face-to-face individual in-depth interviews with 16 officials of the Health, Education and Governmental Departments at various levels were conducted. Results The total number of subjects was 996. 16.7% of the children in the study completed all the procedures of the National Immunization Programme. 34.3% of them had immunization certificates while the remainder 44.7% registered in immunization agencies. Factors, including the migrant children, doubt about vaccine efficiency, mother’s occupation and educational background, knowledge of the National Immunization Programme on targeted vaccines, played an important role in obtaining or not immunization certificates. 95% of the keepers interviewed thought the immunization certificates were useful; 94.8% of them considered the check was critical while only 3.6% of them thought it unnecessary. The first reason from those who found it unnecessary was that they feared that repeated immunization might affect their children’s health. The second reason was the cost of immunization, which some of them could not afford to pay. However, the Health Department expressed a favorable attitude to the checking scheme. Though the Education Department agreed that the scheme was essential, they worried that it would affect the enrollment rate.Conclusion In spite of the difficulty in administering immunization certificate check, the effort would be rewarding for raising the immunization coverage rate among the children in Guizhou Province.展开更多
文摘以重点工程科技楼建设项目为例,通过建立建筑信息模型(Building Information Modeling,BIM),运用信息增益算法,研究多专业参数化模型构件在常规碰撞及复杂碰撞情况下BIM系统对结果的自决及人工决策情况。通过对算法结果进行分析可知,在常规三大项碰撞中,BIM对问题的自我决策结果大多可在项目中直接应用,自决率高,总体自决率达到85.71%;在面对复杂碰撞情况中,人工后期干预决策率远高于BIM自决结果,达到了62.5%。两大类碰撞环境与数据特征明显,对利用数字手段指导建筑工程应用难点起到很好的示范指导作用。
文摘The increasing demand for airline services amidst limited resources results in passenger dissatisfaction and dwindling revenue for airports and airlines. The dynamics of service demand and resource supply results in check-in issues for the stakeholders in the commercial aviation industry. This has the effect of impacting negatively on service performance, cost of operations, customer satisfaction, and overall throughput. Hence, this paper modelled the travelers’ check-in process at the “D Wing” of the Departure Section of Murtala Muhammed International Airport (MMIA), Ikeja, using Arena Software Tool. The work was carried out by determining the parameters of the queues at designated service points in the check-in process. The primary data required to develop the model were acquired by direct observation of passenger flow and oral interview. Thus, the average check-in time was determined. Thereafter, a model of the international check-in system of the MMIA was developed using Arena software in combination with Microsoft Office tools. The data collected were therefore inputted into the model and simulated;the real result was compared with the simulation result of 133 completions and there was no significant difference. The result showed that the model is a representation of the real system under study. Further work will be tailored towards simulation (<em>i.e</em>. the model will be subjected to experimentation in order to have different scenario).
文摘With the current situation of insecurity in Nigeria and the worsening condition of Nigerian roads, there is increasing demand for air travel. This increasing demand for airline services amidst limited resources results in passenger dissatisfaction and reduction of revenue for airports and airlines. The dynamics of service demand and resource supply result in check-in issues for all the stakeholders in the commercial aviation industry. Hence, this research simulated the developed model for travelers’ check-in process at the “D Wing” of the Departure Section of Murtala Muhammed International Airport (MMIA), Ikeja, using Arena Software Tool. The simulation of the developed model was carried out by varying five different configurations of the servers with respect to the baggage weighing machines and passenger profiling devices to obtain the minimum average check-in time (ACT) for the process, with each configuration undergoing 133 completions of simulation runs. The result of the experimentation revealed that the 3 × 3 × 4 configuration of servers produced the smallest ACT of 18.25 minutes. This translates to a difference of about 58 minutes from the 76.16 minutes ACT of the real system;representing about 76% improvement in the check-in time of passengers. This study contributed to knowledge by revealing that the main choke points in the MMIA check-in system occur at the baggage weighing and passenger profiling areas as against the check-in counter sub-section as advanced by previous works. Furthermore, the research added value to knowledge by creating a balance between customer satisfaction and cost of operations thereby accommodating the interests of the passenger and the operator who are the two main stakeholders in the commercial aviation industry.
基金supported by the National Natural Science Foundation of China(No.61401164,No.61201145,No.61471175)the Natural Science Foundation of Guangdong Province of China(No.2014A030310308)the Supporting Plan for New Century Excellent Talents of the Ministry of Education(No.NCET-13-0805)
文摘In this paper, we propose a new method to derive a family of regular rate-compatible low-density parity-check（RC-LDPC） convolutional codes from RC-LDPC block codes. In the RC-LDPC convolutional family, each extended sub-matrix of each extended code is obtained by choosing specified elements from two fixed matrices HE1K and HE1K, which are derived by modifying the extended matrices HE1 and HE2 of a systematic RC-LDPC block code. The proposed method which is based on graph extension simplifies the design, and prevent the defects caused by the puncturing method. It can be used to generate both regular and irregular RC-LDPC convolutional codes. All resulted codes in the family are systematic which simplify the encoder structure and have maximum encoding memories which ensure the property. Simulation results show the family collectively offer a steady improvement in performance with code compatibility over binary-input additive white Gaussian noise channel（BI-AWGNC）.
文摘Objective To study the feasibility of enforcing immunization certificate check before children enroll in primary schools or kindergartens in Guizhou Province. Methods Quantitative and qualitative studies were conducted. The multi-stage and cluster sampling approach was adopted for the quantitative part of the study. A questionnaire was designed and 996 children and their keepers were interviewed. Principals, doctors or teachers of the primary schools, directors and child care nurses of kindergarten, and staff of immunization agencies were invited to take part in 12 focus group discussions; meanwhile, face-to-face individual in-depth interviews with 16 officials of the Health, Education and Governmental Departments at various levels were conducted. Results The total number of subjects was 996. 16.7% of the children in the study completed all the procedures of the National Immunization Programme. 34.3% of them had immunization certificates while the remainder 44.7% registered in immunization agencies. Factors, including the migrant children, doubt about vaccine efficiency, mother’s occupation and educational background, knowledge of the National Immunization Programme on targeted vaccines, played an important role in obtaining or not immunization certificates. 95% of the keepers interviewed thought the immunization certificates were useful; 94.8% of them considered the check was critical while only 3.6% of them thought it unnecessary. The first reason from those who found it unnecessary was that they feared that repeated immunization might affect their children’s health. The second reason was the cost of immunization, which some of them could not afford to pay. However, the Health Department expressed a favorable attitude to the checking scheme. Though the Education Department agreed that the scheme was essential, they worried that it would affect the enrollment rate.Conclusion In spite of the difficulty in administering immunization certificate check, the effort would be rewarding for raising the immunization coverage rate among the children in Guizhou Province.
