Estimating shear strength of high-level pillars supported with cemented backfilling using the HoekeBrown strength criterion

Deep metal mines are often mined using the high-level pillars with subsequent cementation backfilling(HLSCB)mining method.At the design stage,it is therefore important to have a reasonable method for determining the shear strength of the high-level pillars(i.e.cohesion and internal friction angle)when they are supported by cemented backfilling.In this study,a formula was derived for the upper limit of the confining pressure σ3max on a high-level pillar supported by cemented backfilling in a deep metal mine.A new method of estimating the shear strength of such pillars was then proposed based on the Hoek eBrown failure criterion.Our analysis indicates that the horizontal stress σhh acting on the cemented backfill pillar can be simplified by expressing it as a constant value.A reasonable and effective value for σ3max can then be determined.The value of s3max predicted using the proposed method is generally less than 3 MPa.Within this range,the shear strength of the high-level pillar is accurately calculated using the equivalent MohreCoulomb theory.The proposed method can effectively avoid the calculation of inaccurate shear strength values for the high-level pillars when the original HoekeBrown criterion is used in the presence of large confining pressures,i.e.the situation in which the cohesion value is too large and the friction angle is too small can effectively be avoided.The proposed method is applied to a deep metal mine in China that is being excavated using the HLSCB method.The shear strength parameters of the high-level pillars obtained using the proposed method were input in the numerical simulations.The numerical results show that the recommended level heights and sizes of the high-level pillars and rooms in the mine are rational.

Improved Scatter Search Algorithm for Multi-skilled Personnel Scheduling of Ship Block Painting

This paper focuses on the optimization method for multi-skilled painting personnel scheduling.The budget working time analysis is carried out considering the influence of operating area,difficulty of spraying area,multi-skilled workers,and worker’s efficiency,then a mathematical model is established to minimize the completion time. The constraints of task priority,paint preparation,pump management,and neighbor avoidance in the ship block painting production are considered. Based on this model,an improved scatter search(ISS)algorithm is designed,and the hybrid approximate dynamic programming(ADP)algorithm is used to improve search efficiency. In addition,the two solution combination methods of path-relinking and task sequence combination are used to enhance the search breadth and depth. The numerical experimental results show that ISS has a significant advantage in solving efficiency compared with the solver in small scale instances;Compared with the scatter search algorithm and genetic algorithm,ISS can stably improve the solution quality. Verified by the production example,ISS effectively shortens the total completion time of the production,which is suitable for scheduling problems in the actual painting production of the shipyard.

Analysis of the Digital Skill Gap of Agricultural Extension Personnel in South-East, Nigeria

The study analysed the digital skill gap of agricultural extension personnel on the use of digital technologies for extension services delivery in South-East, Nigeria. The specific objectives were to describe the socioeconomic characteristics of agricultural extension personnel in South-East Nigeria and identify the digital skill gaps among agricultural extension personnel in the area of study. Purposive sampling technique was used to select 364 Agricultural Extension personnel for the study. Data were collected through the use of structured questionnaire and were analysed using simple descriptive statistical tools such as percentages, mean score, and standard deviation. Findings indicated that most of the personnel were male (57.8%), within the age bracket of 38 - 47 years (62.9%), had B.Sc./HND as their highest educational qualification (74.7%), married (86.3%), and had a household size of 6 - 10 Persons (57.7%). It was further revealed that the majority (70.1%) were members of professional organization, earned a monthly income of N50,001.00 - N100,000.00 (65.7%), had a work experience of 11 - 15 years (51.1%), and owned a smartphone/ iPad/laptop (91.5%). Findings further indicated that they had moderate skill gap in Basic Computer skills (Mean = 4.32), and digital communication and collaboration skills (Mean = 4.26). Findings also showed that they had a high skill gap in digital technical skills (Mean = 2.46), digital data analysis skills (Mean = 2.09), digital content creation skills (Mean = 2.43), digital ethical skills (Mean = 2.79), multimedia production skills (Mean = 2.81), and video library management skills (Mean = 2.39). The study concluded that though there exists a high digital skill gap among agricultural extension personnel in South-East, Nigeria, their socioeconomic characteristics are capable of supporting the implementation of digital extension services in the area. The study recommended that the management of Agricultural Development Programs in South-East, Nigeria, should provide digital training for extension personnel to close the digital skill gap that currently exists among the personnel.

Comparative Study of the Socioeconomic Characteristics and Digital Literacy Level of Agricultural Extension Personnel in Imo and Ebonyi States, South-East, Nigeria

The study comparatively analysed the socioeconomic characteristics and digital literacy level of Agricultural Extension personnel (AEP) in Ebonyi and Imo States, South-East, Nigeria. The specific objectives were to describe the socioeconomic characteristics of agricultural extension personnel in Ebonyi and Imo States, and to ascertain the digital literacy level of AEP in the studied states. Purposive sampling technique was used to select 312 Agricultural Extension personnel (132 from Ebonyi State Agricultural Development Program and 180 from Imo State Agricultural Development Program) for the study. Data were collected through the use of validated and structured questionnaire, and administered through the help of well-trained enumerators. Data were analysed using simple descriptive statistical tools such as percentages mean score, standard deviation and weighted mean. Findings indicated that they were more male in the both States (55.3% and 57.8%) for Ebonyi and Imo State respectively and that the average age of AEP in Ebonyi and Imo States were 44.7 years and 49.2 years respectively. It was further revealed that the majority (77.3% and 82.8%) had B.Sc./HND as their highest academic qualifications, belonged to professional organisations (62.1% and 75%), and were earning an average monthly income of N58,798 and N62,648 for Ebonyi and Imo State respectively. Also, it was revealed that their mean years of service were 12.4 years and 13.4 years for Ebonyi and Imo State respectively. Almost all of them (87.9% and 95.0%) own a smartphone, had access to the internet (80.3% and 90.0%), but do not own a laptop/ipad (82.6% and 72.8%) for Ebon-yi and Imo State respectively. Results further revealed that Agricultural extension personnel in both Ebonyi and Imo State respectively had low digital literacy level ( = 2.41 and 2.32). The study concluded that AEP in Ebonyi and Imo State respectively had similar socioeconomic characteristics and low level of digital literacy. The study recommended that the management of ADPs in both Ebonyi and Imo State should ensure the training of AEP in digital skills to enhance their digital literacy level to enable them use digital technologies in their work.

Detection Algorithm of Laboratory Personnel Irregularities Based on Improved YOLOv7

Due to the complex environment of the university laboratory,personnel flow intensive,personnel irregular behavior is easy to cause security risks.Monitoring using mainstream detection algorithms suffers from low detection accuracy and slow speed.Therefore,the current management of personnel behavior mainly relies on institutional constraints,education and training,on-site supervision,etc.,which is time-consuming and ineffective.Given the above situation,this paper proposes an improved You Only Look Once version 7(YOLOv7)to achieve the purpose of quickly detecting irregular behaviors of laboratory personnel while ensuring high detection accuracy.First,to better capture the shape features of the target,deformable convolutional networks(DCN)is used in the backbone part of the model to replace the traditional convolution to improve the detection accuracy and speed.Second,to enhance the extraction of important features and suppress useless features,this paper proposes a new convolutional block attention module_efficient channel attention(CBAM_E)for embedding the neck network to improve the model’s ability to extract features from complex scenes.Finally,to reduce the influence of angle factor and bounding box regression accuracy,this paper proposes a newα-SCYLLA intersection over union(α-SIoU)instead of the complete intersection over union(CIoU),which improves the regression accuracy while increasing the convergence speed.Comparison experiments on public and homemade datasets show that the improved algorithm outperforms the original algorithm in all evaluation indexes,with an increase of 2.92%in the precision rate,4.14%in the recall rate,0.0356 in the weighted harmonic mean,3.60%in the mAP@0.5 value,and a reduction in the number of parameters and complexity.Compared with the mainstream algorithm,the improved algorithm has higher detection accuracy,faster convergence speed,and better actual recognition effect,indicating the effectiveness of the improved algorithm in this paper and its potential for practical application in laboratory scenarios.

Research on the Improvement of Incentive Mechanism for Pharmaceutical Sales Personnel - Taking Company A as an Example

Objective To analyze the improvement of the incentive mechanism of sales personnel in pharmaceutical company A,and to promote the smooth operation and further development of the company in a long term.Methods Compensation incentive,performance appraisal,welfare benefit,training incentive,promotion motivation and enterprise cultural inspiration were explored through questionnaires,telephone interviews and in-person interviews.Results and Conclusion This company’s incentive mechanism has problems in two aspects:Material incentives and spiritual incentives.As to the company’s characteristics and strategic development,the optimization countermeasures of incentive mechanism are proposed from the following three aspects:constructing a reasonable incentive system,establishing an efficient spiritual incentive mechanism,and implementing the dynamic incentive and differentiated incentive simultaneously.

Research on the Path of Cultivating High-Level Technical and Skilled Talents in Vocational Undergraduate Colleges and Universities

This paper explores strategies to cultivate high-level technical talents in vocational undergraduate colleges by analyzing their development,the essence of such talents,and proposing several key measures.Strategies include optimizing professional settings and curricula,enhancing school-enterprise cooperation and the integration of industry-university-research,improving teaching staff quality and educational standards,and expanding international cooperation.The importance of policy support and funding and establishing robust quality assurance systems is emphasized for effectively cultivating skilled talents in vocational undergraduate colleges.

民办高校应用型绿色建筑技能人才培养研究

当前国家政策统筹调整产业结构,随着协同推进生态减污、生态保护的美丽中国建设中,伴随建筑产业绿色化、智能化、工业化的发展趋势,中国建造的转型升级需要培养大量新型建筑专业人才。民办高校作为行业人才需求的蓄水池,应以行业变化趋势为依据,以企业人才新需求为基点,重构人才培养体系,一方面要强化新知识、打牢新基础;另一方面建立强化实践育人的人才培养机制。

Relationship between acute stress and sleep disorder in grass-root military personnel:Mediating effect of social support

Background: To explore the relationship between acute stress, social support and sleep disorder in grass-root military personnel, and construct the relational model through structural equation modeling. Methods: A total of 2,411 grass-root military personnel were randomly selected by cluster sampling, and administered the Chinese Military Personnel Sleep Disorder Scale, Military Acute Stress Scale and Social Support Rating Scale.Results: The total score of acute stress scale was positively correlated with the total score and factor scores of sleep disorder scale(r=0.209~0.465, P【0.01); The total score of social support scale was positively correlated with the total score of acute stress scale and the total score and factor scores of sleep disorder scale(r=0.356~0.537, P【0.01). The analysis of mediating effects showed that lack of social support partially mediated between acute stress and the factors of sleep disorder. The analysis of structural equation model showed that acute stress not only had a direct effect on sleep disorder(the path coefficient was 0.29, P=0.000), but also on lack of social support(the path coefficient was 0.39, P=0.000); lack of social support had a direct effect on sleep disorder(the path coefficient was 0.48, P=0.000).Conclusions: Acute stress and lack of social support are two significant factors of sleep disorder in grass-root military personnel. Well-established social support could alleviate sleep disorder induced by acute stress. Lack of social support was a partial mediator between acute stress and sleep disorder.

Prospective study of the prevalence and co-morbidities of obstructive sleep apnea in active-duty army personnel in the three southernmost provinces of Thailand using questionnaire screening

Background: It is crucial for the army to know the prevalence of obstructive sleep apnea(OSA) syndrome in activeduty army personnel. Little information has been reported on the prevalence of OSA and clinical features in activeduty army personnel. This study was aimed to estimate the prevalence of snoring and risk of developing OSA in activeduty army personnel in Thailand and to identify the co-morbidities of OSA. In total, 1107 participants who were aged20–60 years and were deployed to the three southernmost provinces of Thailand were enrolled. All the participants completed the Phramongkutklao(PMK) Hospital OSA Questionnaire that was modified and validated from the Berlin Questionnaire and underwent physical examination. The participants were 1107 active-duty army personnel in the three southernmost provinces of Thailand, both males and females, aged 20–60 years.Methods: The PMK OSA Questionnaire was used to assess the risk of OSA together with interviewing for snoring,fatigue, falling asleep and day-time sleepiness. Physical examination of the neck, chest and hip circumference,and height was performed. Information concerning physical training, co-morbid diseases, smoking and alcoholic consumption was collected.Results: The prevalence of snoring was 58.5, and 4.8% met the PMK OSA Questionnaire criteria, thus indicating a high risk of OSA. The information obtained indicated that laryngopharyngeal reflux(LPR), current smoking and alcoholic consumption were significantly higher in the high-risk OSA group.Conclusions: Early detection and treatment of OSA in active-duty army personnel are imperative. Physical examination and polysomnography can be used to reveal the high-risk group. High body mess index(BMI), laryngopharyngeal reflux, current smoking and alcoholic consumption are modifiable factors for OSA and are avoidable. A policy to decrease the BMI and risk of LPR, as well as to stop smoking and alcoholic consumption, should be applied.

The Beishan underground research laboratory for geological disposal of high-level radioactive waste in China:Planning, site selection,site characterization and in situ tests

With the rapid development of nuclear power in China, the disposal of high-level radioactive waste（HLW） has become an important issue for nuclear safety and environmental protection. Deep geological disposal is internationally accepted as a feasible and safe way to dispose of HLW, and underground research laboratories（URLs） play an important and multi-faceted role in the development of HLW repositories. This paper introduces the overall planning and the latest progress for China＇s URL. On the basis of the proposed strategy to build an area-specific URL in combination with a comprehensive evaluation of the site selection results obtained during the last 33 years, the Xinchang site in the Beishan area,located in Gansu Province of northwestern China, has been selected as the final site for China＇s first URL built in granite. In the process of characterizing the Xinchang URL site, a series of investigations,including borehole drilling,geological mapping, geophysical surveying,hydraulic testing and in situ stress measurements, has been conducted. The investigation results indicate that the geological,hydrogeological, engineering geological and geochemical conditions of the Xinchang site are very suitable for URL construction. Meanwhile, to validate and develop construction technologies for the Beishan URL, the Beishan exploration tunnel（BET）, which is a 50-m-deep facility in the Jiujing sub-area, has been constructed and several in situ tests, such as drill-and-blast tests, characterization of the excavation damaged zone（EDZ）, and long-term deformation monitoring of surrounding rocks, have been performed in the BET. The methodologies and technologies established in the BET will serve for URL construction.According to the achievements of the characterization of the URL site, a preliminary design of the URL with a maximum depth of 560 m is proposed and necessary in situ tests in the URL are planned.

High-level radioactive waste disposal in China: update 2010

For geological disposal of high-level radioactive waste （HLW）, the Chinese policy is that the spent nuclear fuel （SNF） should be reprocessed first, followed by vitrification and final disposal. The preliminary repository concept is a shaft-tunnel model, located in saturated zones in granite, while the final waste form for disposal is vitrified high-level radioactive waste. In 2006, the government published a long-term research and development （R＆D） plan for geological disposal of high-level radioactive waste. The program consists of three steps： （1） laboratory studies and site selection for a HLW repository （2006-2020）; （2） underground in-situ tests （2021-2040）; and （3） repository construction （2041-2050） followed by operation. With the support of China Atomic Energy Authority, comprehensive studies are underway and some progresses are made. The site characterization, including deep borehole drilling, has been performed at the most potential Beishan site in Gansu Province, Northwestern China. The data from geological and hydrogeological investigations, in-situ stress and permeability measurements of rock mass are presented in this paper. Engineered barrier studies are concentrated on the Gaomiaozi bentonite. A mock-up facility, which is used to study the thermo-hydro-mechano-chemical （THMC） properties of the bentonite, is under construction. Several projects on mechanical properties of Beishan granite are also underway. The key scientific challenges faced with HLW disposal are also discussed.

CDIO Based Optimization of Urban Planning Personnel Training Courses in Forestry Universities

On the basis of analyzing existing course system of urban planning discipline,this paper came up with a framework for optimization of urban planning personnel training mode and course system,oriented towards training practical engineering personnel and based on CDIO engineering education and teaching platform. Then it made empirical study on setting of the urban planning discipline in Northeast Forestry University. It proposed changing the original "3 + 2" course system,exploring and optimizing the course system,improving teaching effect of urban planning personnel training courses,and raising planning and design ability of students.

Post-traumatic stress disorder among paramedic and hospital emergency personnel in south-east Iran

BACKGROUND:Paramedic and emergency personnel may encounter directly many events that threat their own wellbeing during their daily work.This study was conducted to examine the prevalence rate of post-traumatic stress disorder(PTSD) among two groups of paramedic and emergency personnel in south-east Iran.METHODS:The study employed a descriptive design and was conducted in four hospital emergency wards and a pre-hospital emergency base supervised by Kerman Medical University.Using Mississippi PTSD,we assessed the prevalence rate in paramedics(n=150) and emergency personnel(n=250).RESULTS:The two groups had different levels of education,marital status,experience of traumatic events,work hours per month,and gender.Most(94%) of paramedic and hospital emergency personnel reported moderate PTSD.The two groups had significant different levels of PTSD in all subscale.CONCLUSION:The study suggests that health care managers should organize systematic and dynamic policies and procedures in dealing with PTSD to assist both groups of personnel.

Novel design of a personnel safety system for Hefei Light Source-Ⅱ

The Hefei Light Source-Ⅱ(HLS-Ⅱ) is a vacuum ultraviolet synchrotron light source. The personnel safety system (PSS), which is a personnel access control system, is a crucial part of the HLS-Ⅱ, as it protects the staff and users at HLS-Ⅱfrom radiation damages. The prior version of HLS-Ⅱ PSS was based on an access control system called SiPass. This lacked the personnel management function. Meanwhile, as the prior PSS is a turn-key system, it was not effective for sharing information. To overcome these drawbacks, the novel design of PSS for HLS-Ⅱ is proposed based on the Siemens redundant programmable logic controller under the Experimental Physics and Industrial Control System. The proposed PSS consists of a safety interlock system, access control system, and a radiation monitoring system. The safety interlock system is used to define the interlock logic. The access control system is designed to restrict the access of staff and users at HLS-Ⅱ, and to provide a personnel management function. The radiation monitoring system is used to monitor the radiation dose rate in both the light source and the surrounding areas. This paper details the architecture and the specific design of the novel PSS. The off-line test results demonstrate that the proposed system has achieved the design objectives.

Migration of Some Elements and Radionuclides across aGranite-Granite Contact Zone: A Natural Analoguefor Safe Disposal of High-Level Radwastes

Abstract Elements and natural radionuclides in the contact zone of two granites with different ages would migrate from one to the other because of the difference in their chemical contents and later water-rock interactions. This migration could serve as an analogue for the near-field process of radwastes in a high-level radwaste deep geological disposal repository.

Three-dimensional numerical simulation of methane drainage by high-level drill holes in a lower protective coal seam with a “U” type face

Different drill-hole positions may produce different drainage results in low protective coal seams.To investigate this possibility,a 3D stope model is established,which covers three kinds of drill holes.The FLUENT computational fluid mechanics software is used to solve the mass,momentum and species conservation equations of the model.The spatial distributions of oxygen and methane was obtained by calculations and the drainage results of different drill-hole positions were compared.The results show that,from top to bottom,methane dilution by oxygen weakens gradually from the intake to the return side,and methane tends to float;methane and oxygen distribute horizontally.The high-level crossing holes contribute to better methane drainage and a greater level of control.Around these holes,the methane density decreases dramatically and a "half circle"distribution is formed.The methane density decreases on the whole,but a proportion of the methane moves back to deep into the goaf.The research findings provide theoretical grounds for methane drainage.

Controlling mine pressure by subjecting high-level hard rock strata to ground fracturing

When mining extra-thick coal seams,the main cause of strong ground pressure are the high-level thick and hard strata,but as yet there is no active and effective control technology.This paper proposes the method of subjecting hard roofs to ground fracturing,and physical simulation is used to study the control effect of ground fracturing on the strata structure and energy release.The results show that ground fracturing changes the structural characteristics of the strata and reduces the energy release intensity and the spatial extent of overburden movement,thereby exerting significant control on the ground pressure.The Datong mining area in China is selected as the engineering background.An engineering test was conducted on site by ground horizontal well fracturing,and a 20-m-thick hard rock layer located 110 m vertically above the coal seam was targeted as the fracturing layer.On-site microseismic monitoring shows that the crack propagation length is up to 216 m and the height is up to 50 m.On-site mine pressure monitoring shows that(1)the roadway deformation is reduced to 100 mm,(2)the periodic weighting characteristics of the hydraulic supports are not obvious,and(3)the ground pressure in the working face is controlled significantly,thereby showing that the ground fracturing is successful.Ground fracturing changed the breaking characteristics of the high-level hard strata,thereby helping to ameliorate the stress concentration in the stope and providing an effective control approach for hard rock.

High-level expression and purification of Plutella xylostella acetylcholinesterase in Pichia pastoris and its potential application

The acetylcholinesterase 2（AChE2）cloned from Plutella xylostella was first successfully expressed in methylotrophic yeast Pichia pastoris GS115.One transformant with high-level expression of the recombinant AChE（rAChE,23.2 U mL-1in supernatant）was selected by plating on increasing concentrations of antibiotic G418 and by using a simple and specific chromogenic reaction with indoxyl acetate as a substrate.The maximum production of r ACh E reached about 11.8 mg of the enzyme protein per liter of culture.The r ACh E was first precipitated with ammonium sulfate（50%saturation）and then purified with procainamide affinity column chromatography.The enzyme was purified 12.1-fold with a yield of 22.8%and a high specific activity of 448.3 U mg-1.It was sensitive to inhibition by methamidophos and pirimicarb,the calculated 50% inhibitory concentration（IC50）values of the two pesticides were 0.357 and 0.888 mg L-1,respectively,and the calculated 70% inhibitory concentration（IC70）values were 0.521 and 0.839 mg L-1,respectively.The results suggested that it has a potential application in the detection of pesticide residues.

In-pit coal mine personnel uniqueness detection technology based on personnel positioning and face recognition

Since the coal mine in-pit personnel positioning system neither can effectively achieve the function to detect the uniqueness of in-pit coal-mine personnel nor can identify and eliminate violations in attendance management such as multiple cards for one person, and swiping one's cards by others in China at present. Therefore, the research introduces a uniqueness detection system and method for in-pit coal-mine personnel integrated into the in-pit coal mine personnel positioning system, establishing a system mode based on face recognition + recognition of personnel positioning card + release by automatic detection. Aiming at the facts that the in-pit personnel are wearing helmets and faces are prone to be stained during the face recognition, the study proposes the ideas that pre-process face images using the 2D-wavelet-transformation-based Mallat algorithm and extracts three face features: miner light, eyes and mouths, using the generalized symmetry transformation-based algorithm. This research carried out test with 40 clean face images with no helmets and 40 lightly-stained face images, and then compared with results with the one using the face feature extraction method based on grey-scale transformation and edge detection. The results show that the method described in the paper can detect accurately face features in the above-mentioned two cases, and the accuracy to detect face features is 97.5% in the case of wearing helmets and lightly-stained faces.