On the basis of the analysis on the disadvantages of the original goal-setting about rock drivage, this paper defined the ＂life cycle quality＂. With project management theory and the Cobb-Douglas function, ＂quality...On the basis of the analysis on the disadvantages of the original goal-setting about rock drivage, this paper defined the ＂life cycle quality＂. With project management theory and the Cobb-Douglas function, ＂quality-cost and quality-price curve model＂ and the ＂total cost-period prediction model＂ were built. Then the goal-setting method of the balance among quality, cost and period of rock drivage was constructed by finding ＂life cycle cost＂ through ＂life cycle quality＂ using ＂quality-cost and quality-price curve model＂ and ensuring period through ＂life cycle cost＂ using ＂total cost-period prediction model＂ （hereinafter referred to as the ＂three goals balance method＂）. ＂Value contribution＂ which is the value of the contribution to a mine because of rock drivage, was found in the process of constructing the ＂quality-cost and quality-price curve model＂. An industrial test was done in coal mine A with the research results, staff footage efficiency improved by 24.24%, the period shortened by 14.3%, the ＂life cycle cost＂ dropped by 2.09%, the ＂life cycle quality price＂ improved by 3.29%, and value contribution increased by 25.3%. The result shows that the new goal method setting on the basis of coal mine profit maximization can ensure construc- tion period. At the same time, it can realize cost and quality objectives and the optimization and balance of relationship among them; rewarding excavation teams by ＂value contribution＂ can combine organizational goal with personal goal, it significantly raise the employee＇s work efficiency.展开更多
To improve the energy efficiency of a direct expansion air conditioning(DX A/C) system while guaranteeing occupancy comfort, a hierarchical controller for a DX A/C system with uncertain parameters is proposed. The con...To improve the energy efficiency of a direct expansion air conditioning(DX A/C) system while guaranteeing occupancy comfort, a hierarchical controller for a DX A/C system with uncertain parameters is proposed. The control strategy consists of an open loop optimization controller and a closed-loop guaranteed cost periodically intermittent-switch controller(GCPISC). The error dynamics system of the closed-loop control is modelled based on the GCPISC principle. The difference,compared to the previous DX A/C system control methods, is that the controller designed in this paper performs control at discrete times. For the ease of designing the controller, a series of matrix inequalities are derived to be the sufficient conditions of the lower-layer closed-loop GCPISC controller. In this way, the DX A/C system output is derived to follow the optimal references obtained through the upper-layer open loop controller in exponential time, and the energy efficiency of the system is improved. Moreover, a static optimization problem is addressed for obtaining an optimal GCPISC law to ensure a minimum upper bound on the DX A/C system performance considering energy efficiency and output tracking error. The advantages of the designed hierarchical controller for a DX A/C system with uncertain parameters are demonstrated through some simulation results.展开更多
Background: Systematic chest X-ray is the most prescribed examination by occupational physicians during periodic medical check-ups in our context, unlike in most countries where this practice has been discontinued. Ob...Background: Systematic chest X-ray is the most prescribed examination by occupational physicians during periodic medical check-ups in our context, unlike in most countries where this practice has been discontinued. Objective: The objective was to determine the diagnostic yield and cost-effectiveness of chest radiography during periodic medical check-ups of workers in Ngaoundere. Materials and Methods: A cross-sectional and descriptive study was carried out in Ngaoundere Regional Hospital from January to December 2018, concerning all persons coming to perform a systematic chest X-ray in the context of the periodic medical check-up having been consented to participate in the study. Posteroanterior (PA) chest radiographs were obtained from all workers during this periodic medical check-up. The variables studied were: age, sex, clinical manifestations, antecedents, job type, cost, and chest X-ray results. Statistical analysis was performed using the Sphinx Plus2-Lexica-V5 Edition software. Results: 753 workers were selected for this study, of whom 88.04% were men and 11.96% were women, a sex ratio H/F is of 7.4, the average age was 39 ± 7.89 years with extremes of 24 and 56 years, the most frequent job type was the administration (38.37%), the storekeepers (17.92) and the drivers (15.27%), most of them were asymptomatic (97.47%), some had cough (2.52%), chest pain (2.12%), dyspnea (0.26%) and fever (0.13%). History was dominated by lung infection (2.39%), pleurisy (1.06%) and tuberculosis (0.79%). 7.43% of workers occasionally smoked tobacco and consumed alcohol. 41 cases of pathologies (5.44%) were found on the chest X-ray, including 1 case (0.13%) of evolutionary pathology, 40 cases (5.31%) of sequelae pathologies. When the results of the chest X-ray are compared with the clinical signs and the pathological history of the workers, it is found that the only case with evolutionary abnormalities on the chest X-ray showed clinical signs and that the other cases with sequelae abnormalities had either clinical signs or antecedents related to these abnormalities. The cost of a chest X-ray at the time of our study was 5,000 FCFA ($8.59), for a total of 3,765,000 FCFA ($6473.74) for all the X-rays performed. Conclusion: In view of the low rate of abnormalities on the chest X-ray and the sequelae nature of the pathologies, it can be said that the routine X-ray of the chest during the periodic medical check-ups has a low diagnostic yield and a low cost-effectiveness ratio and is not profitable. It should be non-systematic and case-by-case based on the clinical context and background of workers.展开更多
目的:了解中国女性1990—2019年妇科疾病负担变化趋势及其年龄、时期、队列效应,为妇科疾病的预防和控制策略的制定提供科学依据。方法:利用2019年全球疾病负担研究(Global Burden of Disease Study 2019,GBD 2019)数据,采用Joinpoint...目的:了解中国女性1990—2019年妇科疾病负担变化趋势及其年龄、时期、队列效应,为妇科疾病的预防和控制策略的制定提供科学依据。方法:利用2019年全球疾病负担研究(Global Burden of Disease Study 2019,GBD 2019)数据,采用Joinpoint回归模型分析中国妇科疾病发病率和伤残调整寿命年(disability adjusted life year,DALY)率的变化趋势,基于年龄-时期-队列模型探讨年龄、时期和队列效应对发病率和DALY率的影响,并分析经前期综合征、生殖器脱垂、子宫肌瘤、子宫内膜异位症、多囊卵巢综合征发病率和DALY率的顺位。结果:1990—2019年中国妇科疾病发病率和DALY率均呈下降趋势,平均每年分别下降0.63%(95%CI:-0.73%~-0.54%,P<0.05)和0.34%(95%CI:-0.43%~-0.24%,P<0.05)。年龄-时期-队列模型结果显示,1990—2019年中国妇科疾病发病率和DALY率的纵向年龄曲线均呈先上升后下降的趋势,在30~34岁达高峰。随着时期的推移,妇科疾病的发病风险和DALY风险均呈下降趋势,以2000—2004年为参考时期(RR=1),2015—2019年时期发病风险下降至最低(RR=0.73,95%CI:0.74~0.71)。1905—1909至1985—1989年出生队列的发病风险和DALY风险呈下降趋势,1990—1994至2000—2004年出生队列略呈上升趋势。1990和2019年常见妇科疾病中经前期综合征发病率(7245.53/10万、5695.02/10万)和DALY率(222.21/10万、197.95/10万)居于首位。结论:我国减少妇科疾病负担的工作已取得一定进展,但疾病负担仍然严重,应加强对年轻女性妇科疾病的健康宣传教育,开展有针对性的普查,提高诊断和治疗技术,继续降低我国的妇科疾病负担。展开更多
文摘On the basis of the analysis on the disadvantages of the original goal-setting about rock drivage, this paper defined the ＂life cycle quality＂. With project management theory and the Cobb-Douglas function, ＂quality-cost and quality-price curve model＂ and the ＂total cost-period prediction model＂ were built. Then the goal-setting method of the balance among quality, cost and period of rock drivage was constructed by finding ＂life cycle cost＂ through ＂life cycle quality＂ using ＂quality-cost and quality-price curve model＂ and ensuring period through ＂life cycle cost＂ using ＂total cost-period prediction model＂ （hereinafter referred to as the ＂three goals balance method＂）. ＂Value contribution＂ which is the value of the contribution to a mine because of rock drivage, was found in the process of constructing the ＂quality-cost and quality-price curve model＂. An industrial test was done in coal mine A with the research results, staff footage efficiency improved by 24.24%, the period shortened by 14.3%, the ＂life cycle cost＂ dropped by 2.09%, the ＂life cycle quality price＂ improved by 3.29%, and value contribution increased by 25.3%. The result shows that the new goal method setting on the basis of coal mine profit maximization can ensure construc- tion period. At the same time, it can realize cost and quality objectives and the optimization and balance of relationship among them; rewarding excavation teams by ＂value contribution＂ can combine organizational goal with personal goal, it significantly raise the employee＇s work efficiency.
基金supported by the National Natural Science Foundation of China(61773220,61876192,61907021)the National Natural Science Foundation of Hubei(ZRMS2019000752)+2 种基金the Fundamental Research Funds for the Central Universities(2662018QD057,CZT20022,CZT20020)Academic Team in Universities(KTZ20051)School Talent Funds(YZZ19004)。
文摘To improve the energy efficiency of a direct expansion air conditioning(DX A/C) system while guaranteeing occupancy comfort, a hierarchical controller for a DX A/C system with uncertain parameters is proposed. The control strategy consists of an open loop optimization controller and a closed-loop guaranteed cost periodically intermittent-switch controller(GCPISC). The error dynamics system of the closed-loop control is modelled based on the GCPISC principle. The difference,compared to the previous DX A/C system control methods, is that the controller designed in this paper performs control at discrete times. For the ease of designing the controller, a series of matrix inequalities are derived to be the sufficient conditions of the lower-layer closed-loop GCPISC controller. In this way, the DX A/C system output is derived to follow the optimal references obtained through the upper-layer open loop controller in exponential time, and the energy efficiency of the system is improved. Moreover, a static optimization problem is addressed for obtaining an optimal GCPISC law to ensure a minimum upper bound on the DX A/C system performance considering energy efficiency and output tracking error. The advantages of the designed hierarchical controller for a DX A/C system with uncertain parameters are demonstrated through some simulation results.
文摘Background: Systematic chest X-ray is the most prescribed examination by occupational physicians during periodic medical check-ups in our context, unlike in most countries where this practice has been discontinued. Objective: The objective was to determine the diagnostic yield and cost-effectiveness of chest radiography during periodic medical check-ups of workers in Ngaoundere. Materials and Methods: A cross-sectional and descriptive study was carried out in Ngaoundere Regional Hospital from January to December 2018, concerning all persons coming to perform a systematic chest X-ray in the context of the periodic medical check-up having been consented to participate in the study. Posteroanterior (PA) chest radiographs were obtained from all workers during this periodic medical check-up. The variables studied were: age, sex, clinical manifestations, antecedents, job type, cost, and chest X-ray results. Statistical analysis was performed using the Sphinx Plus2-Lexica-V5 Edition software. Results: 753 workers were selected for this study, of whom 88.04% were men and 11.96% were women, a sex ratio H/F is of 7.4, the average age was 39 ± 7.89 years with extremes of 24 and 56 years, the most frequent job type was the administration (38.37%), the storekeepers (17.92) and the drivers (15.27%), most of them were asymptomatic (97.47%), some had cough (2.52%), chest pain (2.12%), dyspnea (0.26%) and fever (0.13%). History was dominated by lung infection (2.39%), pleurisy (1.06%) and tuberculosis (0.79%). 7.43% of workers occasionally smoked tobacco and consumed alcohol. 41 cases of pathologies (5.44%) were found on the chest X-ray, including 1 case (0.13%) of evolutionary pathology, 40 cases (5.31%) of sequelae pathologies. When the results of the chest X-ray are compared with the clinical signs and the pathological history of the workers, it is found that the only case with evolutionary abnormalities on the chest X-ray showed clinical signs and that the other cases with sequelae abnormalities had either clinical signs or antecedents related to these abnormalities. The cost of a chest X-ray at the time of our study was 5,000 FCFA ($8.59), for a total of 3,765,000 FCFA ($6473.74) for all the X-rays performed. Conclusion: In view of the low rate of abnormalities on the chest X-ray and the sequelae nature of the pathologies, it can be said that the routine X-ray of the chest during the periodic medical check-ups has a low diagnostic yield and a low cost-effectiveness ratio and is not profitable. It should be non-systematic and case-by-case based on the clinical context and background of workers.
文摘目的:了解中国女性1990—2019年妇科疾病负担变化趋势及其年龄、时期、队列效应,为妇科疾病的预防和控制策略的制定提供科学依据。方法:利用2019年全球疾病负担研究(Global Burden of Disease Study 2019,GBD 2019)数据,采用Joinpoint回归模型分析中国妇科疾病发病率和伤残调整寿命年(disability adjusted life year,DALY)率的变化趋势,基于年龄-时期-队列模型探讨年龄、时期和队列效应对发病率和DALY率的影响,并分析经前期综合征、生殖器脱垂、子宫肌瘤、子宫内膜异位症、多囊卵巢综合征发病率和DALY率的顺位。结果:1990—2019年中国妇科疾病发病率和DALY率均呈下降趋势,平均每年分别下降0.63%(95%CI:-0.73%~-0.54%,P<0.05)和0.34%(95%CI:-0.43%~-0.24%,P<0.05)。年龄-时期-队列模型结果显示,1990—2019年中国妇科疾病发病率和DALY率的纵向年龄曲线均呈先上升后下降的趋势,在30~34岁达高峰。随着时期的推移,妇科疾病的发病风险和DALY风险均呈下降趋势,以2000—2004年为参考时期(RR=1),2015—2019年时期发病风险下降至最低(RR=0.73,95%CI:0.74~0.71)。1905—1909至1985—1989年出生队列的发病风险和DALY风险呈下降趋势,1990—1994至2000—2004年出生队列略呈上升趋势。1990和2019年常见妇科疾病中经前期综合征发病率(7245.53/10万、5695.02/10万)和DALY率(222.21/10万、197.95/10万)居于首位。结论:我国减少妇科疾病负担的工作已取得一定进展,但疾病负担仍然严重,应加强对年轻女性妇科疾病的健康宣传教育,开展有针对性的普查,提高诊断和治疗技术,继续降低我国的妇科疾病负担。
