Field Test Results Research Articles

Refining Glaucoma Management: Korean Population-Specific Findings from Visual Field and Optical Coherence Tomography Testing

Background/Objectives: This study aimed to serve as a reference for establishing glaucoma evaluation standards for the Korean by analyzing the results of visual field tests and optical coherence tomography (OCT). We also determined the correlation between these test results and patient demographics, such as age and sex, which is crucial for early glaucoma detection and management. Methods: This study was conducted at a national hospital in Seoul and analyzed 1510 visual field tests and 1337 OCT tests. The patients underwent the Humphrey automated visual field test and OCT measurements. Glaucoma was classified into early, moderate, and advanced stages based on the mean deviation (MD) value. Statistical analyses were performed to assess the relationships between age, sex, and test results. Results: The visual field test results showed that the visual field index and MD values decreased as age increased for both males and females, with a more significant decrease observed in males. The OCT findings revealed gradual thinning of the ganglion cell–inner plexiform layer (GCIPL) and retinal nerve fiber layer (RNFL) with increasing age, although, compared to males, thicker GCIPLs and RNFLs were maintained in females until their 60s. Conclusion: This study indicates that there may be an association between age and sex in glaucoma progression and provides valuable insights for establishing diagnostic and management modalities specifically for Korean patients. These findings support the use of both visual field testing and OCT in glaucoma diagnosis, emphasizing the importance of early detection and personalized treatment strategies for effective glaucoma management in Korea.

Application of deep learning for real-time detection, localization, and counting of the malignant invasive weed Solanum rostratum Dunal

Solanum rostratum Dunal (SrD) is a globally harmful invasive weed that has spread widely across many countries, posing a serious threat to agriculture and ecosystem security. A deep learning network model, TrackSolanum, was designed for real-time detection, location, and counting of SrD in the field. The TrackSolanmu network model comprises four modules: detection, tracking, localization, and counting. The detection module uses YOLO_EAND for SrD identification, the tracking module applies DeepSort for multi-target tracking of SrD in consecutive video frames, the localization module determines the position of the SrD through center-of-mass localization, and the counting module counts the plants using a target ID over-the-line invalidation method. The field test results show that for UAV video at a height of 2m, TrackSolanum achieved precision and recall of 0.950 and 0.970, with MOTA and IDF1 scores of 0.826 and 0.960, a counting error rate of 2.438%, and FPS of 17. For UAV video at a height of 3m, the model reached precision and recall of 0.846 and 0.934, MOTA and IDF1 scores of 0.708 and 0.888, a counting error rate of 4.634%, and FPS of 79. Thus, the TrackSolanum supports real-time SrD detection, offering crucial technical support for hazard assessment and precise management of SrD.

基于 DEM 的开沟刀结构参数优化与试验

This study developed a chain counter-rotating trenching and backfilling device to reduce high tillage resistance in orchard operations. A 3D mathematical model of the trenching blade was created using Cartesian coordinate transformation. Taking curvature (β), curve angle (α), bend radius (R), and cone residual angle (θ) as experimental factors, and soil cutting resistance as the evaluation index. The optimized parameters were β=95°, α=10°, R=24 mm, θ=39°. Bench tests were performed with the optimal parameters, and the results showed that the optimized ditching blade reduced the resistance by 18.7% compared to the ordinary trenching blades. Field test results showed a 9.64% reduction in furrowing torque.

Swelling potential and swelling pressure calculation methods: A comprehensive review

Expansive soils, characterized by volume changes due to variations in water content, significantly affect geotechnical engineering. Proper assessment of swelling potential and swelling pressure is essential for improving foundation design on expansive soils, enabling a reduction in risks arising from soil expansion. Different methods for measuring and calculating swelling potential and swelling pressure have been developed, ranging from empirical to analytical approaches, many of which are based on laboratory tests and analysis of soil properties. The paper presents a new classification of these methods, categorizing them into qualitative, semi-qualitative, and quantitative methods. Indirect methods of swell classification are qualitative and semi-qualitative approaches, which may be either single or multi-index methods. In contrast, quantitative approaches are direct methods based on laboratory or field test results. This review will provide researchers and engineers with an easy evaluation of the expansion potential of expansive soils using various methods.

Dynamic Heat Transfer Modeling and Validation of Super-Long Flexible Thermosyphons for Shallow Geothermal Applications

In comparison to borehole heat exchangers that rely on forced convection, super-long thermosyphons offer a more efficient approach to extracting shallow geothermal energy. This work conducted field tests on a super-long flexible thermosyphon (SFTS) to evaluate its heat transfer characteristics. The tests investigated the effects of cooling water temperature and the inclination angle of the condenser on the start-up characteristics and steady-state heat transfer performance. Based on the field test results, the study proposed a dynamic heat transfer modeling method for SFTSs using the equivalent thermal conductivity (ETC) model. Furthermore, a full-scale 3D CFD model for geothermal extraction via SFTS was developed, taking into account weather conditions and groundwater advection. The modeling validation showed that the simulation results aligned well with the temperature and heat transfer power variations observed in the field tests when the empirical coefficient in the ETC model was specified as 2. This work offers a semi-empirical dynamic heat transfer modeling method for geothermal thermosyphons, which can be readily incorporated into the overall simulation of a geothermal system that integrates thermosyphons.

Numerical simulation study of coal seam dual-porosity medium fluid-solid coupling model and directional long borehole gas drainage

To accurately reflect the gas migration law during coal seam gas drainage, this study established a coal seam dual-porosity medium fluid-solid coupling model that takes into account the influence of matrix gas diffusion, fracture gas seepage, Klinkenberg effect and tortuosity. A three-dimensional numerical simulation of directional long boreholes gas drainage in coal seams was then performed using COMSOL simulation software and the accuracy of the model was verified by field test results. The research results showed that the maximum error between the effective drainage radius of directional long boreholes obtained from numerical simulation and the field test results is 6.0%, which validates the accuracy of the constructed dual-porosity medium fluid-solid coupling model in coal seams. In addition, this paper compared and analyzed the effective drainage radius of long boreholes and coal seam permeability obtained by numerical simulation under different influencing factors, and found that the effective drainage radius and permeability without considering Klinkenberg effect and fracture gas seepage are relatively small, while the effective drainage radius and permeability without considering tortuosity and matrix gas diffusion are relatively large. This indicated that Klinkenberg effect and fracture gas seepage promote coal seam gas flow, while tortuosity and matrix gas diffusion inhibit it.

Investigating the potential of geothermal heat pump and precision air supply system for heat stress abatement in dairy cattle barns.

Maintaining an optimal indoor thermal environment is crucial for enhancing the welfare and productivity of livestock in intensive breeding farms. This paper investigated the application of a combined geothermal heat pump with a precision air supply (GHP-PAS) system for cooling dairy cows on a dairy farm. The effectiveness of the GHP-PAS system in mitigating heat stress in lactating dairy cattle, along with its energy performance and local cooling efficiency in the free stalls were evaluated. A total of 140 multiparous lactating Holstein cows was tested in two groups. One group was housed in a barn equipped with a GHP-PAS system (GP barn, n=70), and the other was housed in a barn with a conventional fan-sprinkling system (FS barn, n=70). Results showed that the ambient temperature of both GP and FS barns were lower than that outside the barn (P<0.05), with no significant difference between the GP and FS barns (P>0.05). Compared to cows in the FS barn, those in the GP barn exhibited lower skin temperature, rectal temperature, and respiratory rate (P<0.05). The mean temperature difference between outflow and inflow water was 2.56°C of the GHP unit. The average energy efficiency ratios (EER) of the GHP unit and the GHP-PAS system were 5.03 and 2.92, respectively. The daily average electricity consumption was 20.4±1.0 kWh. The field test results indicated that the airflow from a single nozzle of the GHP-PAS system effectively covered a stall space with an average width of 1.84m at a cow reclining height of 0.5m, with an average air velocity of 1m/s. The per-cow hourly electricity consumption for cooling was 2.04 kWh for the GHP-PAS system and 0.36 kWh for the FS system, highlighting that the GHP-PAS system is approximately 5.6 times more energy-intensive than the FS system. In conclusion, the GHP-PAS system showed the potential for alleviating heat stress in dairy cows. Further research is needed to enhance the energy efficiency and cooling effectiveness of the current GHP-PAS system.

Design of attitude-adjustable chassis and dynamic stress analysis of key components for crawler combine harvester

To address the issues of leveling difficulties and poor stability of crawler combine harvesters in hilly and mountainous regions, this research analyzed the mechanical causes of overturning instability in crawler combine harvesters and designed an omnidirectional attitude adjustment chassis based on a five-bar mechanism. A 3D model was developed in SolidWorks, and coupled rigid-flexible simulations were performed using RecurDyn. Results showed that the chassis could achieve an overall lift, lateral adjustments and longitudinal adjustments (0-100 mm, -5.18° to 5.55° and -4.06° to 5.15° respectively), with maximum dynamic stress occurring on the left front and left rear rotational arms. A dynamic stress testing system was established to conduct response surface experiments. Field test results revealed that the primary factors affecting the maximum stress of the left front rotational arm were the grain tank loading mass, lateral adjustment angle, and longitudinal adjustment angle. For the left rear rotational arm, the order was the longitudinal adjustment angle, lateral adjustment angle, and grain tank loading mass. Validation tests showed that at a lateral adjustment angle of 3.61°, a longitudinal adjustment angle of 3.20°, and a grain tank load of 350 kg, the average maximum stresses were 483.19 MPa for the left front rotational arm and 188.95 MPa for the left rear rotational arm, with corresponding structural safety factors of 1.61 and 4.31, meeting strength requirements. This work provides methods for optimizing the design and reliability testing of agricultural machinery chassis with attitude adjustment functions in hilly terrains.

Automated Mulched Transplanting of Angelica Seedlings Using a Pneumatic Sowing Device

To address the challenges of labor-intensive, inefficient, and inconsistent manual hole sowing and transplanting of Angelica sinensis in rain-fed hilly regions of Northwest China, a pneumatic hole-sowing device was designed based on the principle of electromagnetically controlled, high-speed reciprocating cylinder motion. Considering the agronomic requirements for transplanting mulched Angelica sinensis, the device’s structure and operational parameters were optimized. The key mechanisms involved in hole sowing and seedling placement were analyzed. A pneumatic circuit system, controlled by a relay circuit, was established, and a hole-sowing mechanism with a delayed closure effect was designed. Using the Discrete Element Method (DEM) and Multi-Body Dynamics (MBD) coupling technology, a simulation of the hole-sowing process was conducted to evaluate the device’s performance and its impact on soil disturbance and hole reformation in the seedbed. Prototype device performance tests were conducted, using qualified seeding depth under mulch and hole spacing as indicators. When the theoretical hole spacing was 30 cm and the hole-sowing frequency was 60 plants/(min·row), the soil bin test results indicated a seeding depth qualification rate of 93%, a misalignment rate of 3%, and a spacing qualification rate of 83%; the field test results showed a qualified seeding depth rate under mulch of 96%, the hole misalignment rate was 5%, and the spacing qualified rate was 86%. The pneumatic hole-sowing device’s performance meets the agronomic requirements for vertical transplanting of Angelica sinensis seedlings. This research can serve as a reference for designing planting machinery for rhizomatous medicinal plants.

Development of a magnetic activator to protect an electric water heater against scale formation

The paper is dedicated to the research and development of a magnetic activator for the prevention of scale formation in electric water heaters, which is a pressing problem in regions with hard water, typical for Сentral Kazakhstan. During the operation of water heaters, salt deposits on heating elements lead to increased energy consumption and reduced efficiency. The developed activator uses powerful neodymium magnets that change the structure of the hardness salts in the water, preventing their deposition in the form of scale. Research has shown that the use of a magnetic activator can reduce water hardness by 15–20 %, resulting in a significant reduction in scale formation. In particular, under normal operating conditions, the thickness of the scale layer can reach 2–4 mm, but with the use of the magnetic activator this indicator is reduced to less than 1 mm. Descaling the heating elements not only extends the life of the water heater, but also reduces energy costs. Energy consumption is reduced by 10–15 %, as water heaters with less scale work more efficiently without requiring additional energy for heating. The paper also discusses the design features of the magnetic activator, the principles of its operation and the results of laboratory and field tests. Economic analysis has shown that the installation of the magnetic activator pays for itself within 1–2 years due to the reduction in limescale and energy costs. This makes it an attractive solution for private households as well as for industrial companies that use water heaters in their production process, as the proposed magnetic activator is an effective solution for protecting water heaters from the negative effects of hard water

An enhanced GNSS/INS navigation compensation method using LSTM-FPN for bridging GNSS outages

Abstract The integrated navigation system combining the Global Navigation Satellite System (GNSS), and Inertial Navigation System (INS) is extensively utilized for navigation and positioning, yet it encounters significant accuracy degradation in a GNSS-denied environment due to interference with the GNSS signals. To enhance the positioning accuracy of the integrated GNSS/INS during GNSS outages, this study proposes a compensation method for the GNSS/INS integrated navigation system, assisted by Long Short-Term Memory with Feature Pyramid Network (LSTM-FPN) model. This method corrects navigation errors in the INS by predicting GNSS pseudo-measurements and integrating them with INS. The LSTM-FPN enhances its adaptability to changes at different time scales in time series by extracting and fusing multi-scale temporal features, significantly improving prediction accuracy and the robustness of the model against noise and outliers. The results of real field test demonstrate that compared to pure INS, the LSTM-FPN significantly increases positioning accuracy during GNSS outages of 30 s, 90 s, and 180 s, with improvements of 90.19%, 93.03%, and 98.83%, respectively. Thus, the method effectively enhances positioning accuracy during GNSS outages.

凹杆式薯土分离装置仿真分析与优化

The limited separation efficiency of potato-soil separation equipment in the southern potato planting areas is attributed to the high viscosity of the soil. To enhance the performance of the lifting chain separation device, a concave bar was designed. Structural parameters influencing the efficiency of potato-soil separation by bars were determined through kinetic analysis during the separation and transportation of potato-soil mixtures. Both a potato simulation model and a sticky soil simulation model were developed. Simulation tests indicated that the concave bar outperforms the straight bar in separation efficiency. Key factors investigated include the angle of the concave side, the width of the concave bar, the depth of the concave bar, and the installation angle. Orthogonal simulations were conducted using separation efficiency and the maximum force on potatoes as evaluation metrics. The results demonstrated that with a concave side angle of 15°, a concave bar width of 450 mm, a concave bar depth of 60 mm, and an installation angle of 30°, the separation efficiency of the potato-soil mixture reached 79.7%, with a maximum force on potatoes of 35.218 N, achieving the highest separation efficiency. Based on these results, test devices were constructed, and field tests were performed. The field test results showed a damage rate of 1.58%, a potato epidermal injury rate of 1.03%, and a loss rate of 2.87%. These results comply with national standards and validate the reliability of the simulation findings.

扒齿输送带式荞麦捡拾装置的设计与试验研究

To address the high rate of grain loss in the two-stage harvest of buckwheat, a pickup-tooth conveyor belt type buckwheat pickup device was developed to mitigate the grain loss in the buckwheat pickup process. The critical components of the pickup mechanism and conveyor mechanism were designed, and the essential parameters were determined. The operational efficiency of pickup-tooth conveyor belt type buckwheat pickup device was verified through field orthogonal test. The field test results indicate that the loss rate is most significantly affected by the speed of the pickup device, followed by the tilt angle of the pickup-tooth. The forward speed of the machine exerts minimal influence. After the multi-objective parameters of the regression equation model were optimized, the optimal parameters of the factors were obtained: the forward speed of the machine of 0.8 m/s, the pickup speed of 1.1 m/s, as well as the pickup-tooth tilt angle of 0°, Under the above condition, the loss rate of buckwheat grain reached 6.92%.

Increasing Wear Resistance of Ploughshare by Electrofriction Treatment

Surface layers of agricultural machinery working bodies are subjected to intensive abrasive wear during operation, which leads to rapid wear of equipment and reduction of its service life. To increase the wear resistance of the working surfaces of tools, the method of induction cladding using ‘Sormait-1’ materials is widely used. However, after coating, additional heat treatment is required, which improves physical and mechanical properties of the material and increases its durability. When using electrofriction technology (EFT) hardening, the surface of the parts is subjected to melting under the influence of electric arcs, which affects the surface characteristics of the coatings. In this work, two types of surface treatment of L53 steel were investigated: induction cladding using ‘Sormait-1’ material, as well as a combination of induction cladding and subsequent electrofriction treatment. The coatings were characterized and compared with the substrate in terms of the following parameters: microstructure, phase composition, hardness distribution, and friction-wear characteristics. After induction cladding of the Sormait-1 material, a dendritic structure was formed; however, subsequent electrofriction treatment resulted in a reduction of this dendritic structure, which contributed to an increase in the hardness of the material. The average hardness of the coatings after electrofriction treatment was 786 HV0.1, which is more than three times the hardness of the substrate. Furthermore, the influence of structural characteristics and hardness on abrasive wear resistance was examined in accordance with ASTM G65 international standards. Field tests were conducted on plough shares before and after electrofriction hardening to evaluate their performance. Each ploughshare was scanned with a structured 3D scanner before and after use in the field. From the scan data, the cutting-edge profile was calculated and three key parameters were determined: linear wear, volumetric wear, and mass reduction. According to the results of field tests, it was found that the service life of the blades hardened by electrofriction technology was 12%–14% higher compared to serial blades processed by induction cladding with the use of ‘Sormait-1’ material. Operational tests of hardened plough shares confirmed the results of laboratory tests and proved the advantages of electrofriction technology for increasing the wear resistance of soil tillage machine working bodies.

Analysis of the indoor wind environment in buildings on the Qinghai-Tibet plateau of China: A case study of the Dege Scripture Printing House

The Dege Scripture Printing House (DSPH), built in 1729, is located on the southeastern edge of the Qinghai-Tibet plateau and serves as a significant center for Tibetan Buddhism culture. Compared to typical Tibetan architecture, DSPH features unique characteristics, such as its substantial size, diverse structures, and adaptability to the local climate. The surrounding topography of DSPH primarily comprises plateaus and hilly plains, and the region experiences a continental plateau monsoon climate. This climate is characterized by cold temperatures due to high altitude, low precipitation, long sunshine hours, dry air, long winters, short summers, and intense solar radiation. To thoroughly assess the ventilation status of DSPH, a 3D scan of the building, physical environment tests, and indoor wind environment simulations were carried out. The field test results show that the unique architectural design of DSPH helps mitigate the impact of the harsh climate on indoor activities. By analyzing and evaluating the wind environment of DSPH, locally adapted climate resilience practices are summarized, and the physical properties of buildings characteristic of the Tibetan plateau are clarified. These findings provide a reference for promoting the development of local climate-adapted buildings, preserving traditional architectural culture, and promoting the integration of modern architecture with traditional culture. Furthermore, this study represents an important step toward enhancing energy efficiency and green building practices in ethnic minority settlements, contributing to sustainable development in the region.

Efficiency of Dimensional Analysis in Predicting Compression Load–Settlement Relationship of Soft Clay Under a Rigid Foundation

Dimensional analysis is an effective tool for designing laboratory tests, and it is also a successful method to reasonably predict the results of large-scale or field tests, which are difficult and costly to perform, by considering the outcomes obtained from small-scale tests. This paper therefore focuses on predicting the compression load–settlement relationship of soft clay soil under a rigid foundation by dimensional analysis. For that purpose, a series of dimensionless pi (π) terms were first produced for the relevant problem by employing Buckingham’s pi (π) theorem via the MATLAB program. Secondly, the results of a small-scale physical test reported in the literature that investigated the load–settlement relationship of soft clay soil under a rigid foundation subjected to compression load were verified with the finite element method. Thereafter, the small-scale problem was scaled up several times using dimensionless terms, and the compression load–settlement relationship for the large-scale cases was investigated with both dimensional analysis and the validated finite element method. The findings indicate that dimensional analysis produces reasonably successful outcomes considering the computational ease. In addition, the MATLAB program presented in this paper is quite useful for those desiring to determine the dimensionless terms belonging to any sort of problem.

Numerical modelling of pile jacking in highly sensitive clays

This paper presents large deformation finite element (FE) modelling of penetration of solid cylindrical piles into highly sensitive soft clay. The simulations are performed using a Coupled Eulerian–Lagrangian (CEL) FE modeling technique. The pile is penetrated at a constant rate, and the analyses are performed for undrained conditions to simulate the response during penetration. The soil model considers the effects of strain softening and strain rate on the undrained shear strength. The FE-calculated results are compared with available analytical and numerical solutions for idealized soil profiles. Simulations are also performed for two instrumented piles previously installed into highly sensitive clay at Saint-Alban in Québec, Canada. The installation-induced changes in stresses, degradation of undrained shear strength, and tip resistance obtained from FE analyses are consistent with the field test results. Large plastic shear strains develop near the pile, which can significantly remould the soil near the pile shaft. A parametric study shows that a quicker post-peak degradation of undrained shear strength of highly sensitive clay creates a smaller zone of high plastic shear strain near the pile, while the plastic zone is wider for low- to non-sensitive clays.

Pengembangan modul ajar menulis naskah drama satu babak Kurikulum Merdeka untuk peserta didik kelas XI SMK

This development study was conducted to create and make an independent curriculum-based teaching tool for trade school students in grade 11 that teaches them how to write play plots. The ADDIE model was used in this development research, which had five steps: analysis, design, development, implementation, and evaluation. This study led to the creation of an independent curriculum-based play script writing training program that both subject and practice experts have approved. Field tests were also done to see what the students learned and how they responded. The development study led to creating teaching modules that could be used for learning. These modules got scores of 94.22% from material experts and 96.44% from practitioner experts. The field test found that 50.8% of students learned what they were supposed to learn and that 93.3% of students responded. A score of 83.69% was found in the "very feasible" group based on validation and field test results. Thus, the teaching module developed is suitable for use in learning. However, the percentage of student learning outcomes is a consequence of researchers' limited time in conducting development research. Therefore, drama script writing training is needed based on the results obtained.

Development of FBG-based road ice thickness monitoring sensor and its application on the traffic road

To real-time monitoring of the thickness of the ice layer on the road surface and enhance the safety of traffic operation, based on the fiber grating wavelength division multiplexing (WDM) technology, this paper develops a kind of monitoring sensor for the thickness of the ice layer by pasting multiple fiber Bragg gratings (FBG) on one equal-strength beam, and constructs an experiment on the measurement of the thickness of ice layer to explore the sensor’s validity. Finally, the developed sensor was installed on the sidewalk of one traffic road to monitor the ice layer thickness of the road in real time. The experimental and field test results show that the sensor can effectively measure the thickness of ice layer, and the measurement accuracy is related to the FBG spacing on the equal-strength beam in the sensor.

Field Performance Testing and Test Codes for Gas Compressors

Abstract Field testing of gas compressor packages requires the accurate determination of efficiency, capacity, head, and power in sometimes less than ideal working environments. The results of field tests have significant implications for the compressor manufacturers and their customers, as economic considerations demand that the performance and efficiency of an installation are verified to assure a project's return on investment. Thus, for the compressor manufacturers, as well as for the end user, an accurate determination of the compressor performance in the field is of vital interest. While field performance tests have to be executed under conditions dictated by the situation at site, factory test codes like ASME PTC10 and International Organization for Standardization (ISO) 5389 provide guidance. The former code was recently revised, so a discussion of this revised code in the context of site performance testing is appropriate. A key change in PTC10 is the method to calculate polytropic work, which affects data reduction. It also affirms a method to calculate error propagation and test uncertainties. The discussion includes the appropriate use of equations of State (EOS) and the definition of steady-state requirements. Different methods to define valid operating conditions for the test based on similarity considerations are compared. However, field tests, unlike factory tests, are ultimately conducted based on the conditions at site that may or may not conform with test codes. Therefore, calculation of test uncertainties and the use of observations not covered by the codes are emphasized. The paper attempts to provide guidance for the conduct of field performance tests.