esa-sceva/satcom-chunk-collection huggingface dataset:
# Bioassays with _Allium cepa_ for the Monitoring of Toxicity in the Groundwater of Yucatan, Mexico
## 3 Results and Discussion
### Pesticides  
Measured concentrations of organochlorine pesticides, chlorpyrrifos, and caffeine are presented in Table 3. PCO analysis explained 69.4% of the variation in the first two axes (Figure 6). PERMANOVA indicated no significant differences between sites (\(p\) = 0.7902, PseudoF = 0.74519) or transects (\(p\) = 0.1074, Pseudo-F = 1.94). \(\alpha\)-HCH, \(\gamma\)-HCH, and DDT were the pesticides with the highest prevalence, with 85.71%, 64.29%, and 57.14%, respectively. The pesticides found at the highest concentration were \(\delta\)-HCH and chlorpyrrifos, with 141.44 and 175.92 ng/L, respectively. \(\gamma\)-HCH, heptachlor, aldrin, and DDT and its metabolites are regulated in NOM-127-SSA-2021, which includes the permitted values of pollutants in water for human use or consumption. In the present study, none of the sites had values above this threshold. Heptachlor and Aldrin were only present in sites P4 oct and P2 sept. Interestingly, DDT values are highly correlated with caffeine concentrations. This result may indicate that DDT is linked to domestic discharges. Figure 5: Cluster Analysis with SIMPROF test of nutrients measured in September (sept) and October (oct) 2021 in wells of Yucatan, Mexico. Inverted triangles are used in samples measured in transect 1 (Sierra Papacal to Chuburná) and circles are used in transect 2 (Nohuayū to Sisal). Colors indicate its nearness to the coast; inland samples are presented from red to green, and the sites nearest to the coast are blue. Dashed red lines are used to mark pseudo-groups indicated by the SIMPROF test. \begin{table}
\begin{tabular}{l l l l l l l l l} \hline \hline \multirow{2}{*}{**Compound**} & \multirow{2}{*}{**Month**} & \multicolumn{6}{c}{**Site**} \\ \cline{3-8}  & & **P1** & **P2** & **P3** & **P4** & **P5** & **P6** & **P7** \\ \hline \multirow{2}{*}{\(\alpha\)-HCH} & September & ND & 13.07 & 81.61 & ND & 38.78 & 31.75 & 85.71 \\ \cline{2-8}  & October & 43.77 & 48.03 & 79.26 & 27.7 & 25.57 & 38.19 & 64.23 \\ \hline \multirow{2}{*}{\(\beta\)-HCH} & September & 60.30 & 54.14 & 64.61 & 53.50 & ND & 41.86 & ND \\ \cline{2-8}  & October & ND & ND & ND & ND & ND & 37.01 & ND \\ \hline \multirow{2}{*}{\(\gamma\)-HCH} & September & 30.05 & 30.82 & ND & ND & 45.28 & 35.21 & 66.37 \\ \cline{2-8}  & October & 44.93 & 45.23 & 70.08 & 45.22 & ND & ND & ND \\ \hline \hline \end{tabular}
\end{table} 
Table 3: Organochlorine pesticides, chlorpyrrifos, and caffeine in wells of Yucatan, México in September and October 2021. Values expressed in ng/L. ND: Not detected. Figure 6: Principal Coordinate Analysis (PCO) of pesticides and caffeine measured in September and October 2021 in wells of Yucatan, Mexico. Inverted triangles are used in samples measured in transect 1 (Sierra Papacal to Chuburna) and circles are used in transect 2 (Nohuayün to Sisal). Colors indicate its nearness to the coast; inland samples are presented from red to green, and the sites nearest to the coast are blue.
## 4 Conclusions  
This paper reported a ten-month test including the indoor environment, outdoor environment, exhaust fume system, and makeup air system of a university canteen in Tianjin from April 2019 to January 2020. In addition, we also interviewed the chef's thermal comfort in the canteen kitchen. The main conclusions were as follows.  
1. The temperature in the canteen kitchen varied with the seasons. With 64.88% and 76.92% of the working time in the cooking zone being in the acceptable range (18-32 \({}^{\circ}\)C) in spring and autumn, respectively. In winter, the temperature was the lowest. The temperature in the cooking zone was the highest in summer, with about 82.92% of the working hours above the acceptable range.
2. The indoor air environment quality was affected by the cooking methods. When four stoves were used simultaneously, the cooking methods of four stoves were stir-frying or frying, the temperature of the cooking zone was 4.30 \({}^{\circ}\)C or 4.70 \({}^{\circ}\)C higher than that of three or two stoves used to stir-fry or fry, respectively. Therefore, chefs can alleviate the overheating of the cooking zone during the cooking process by avoiding cooking stir-fried or fried dishes simultaneously. In addition, the difference from the previous study result, the changing trend of the temperature and the relative humidity were opposite. It may be due to the traditional cooking methods of the Chinese canteen kitchen.
3. The questionnaire results were consistent with the test results. The chefs' thermal sensations varied with the season. In summer, 83.33% of chefs felt hot. Most chefs' wet sensations in the four seasons were neutral. In addition, there were 83.33% of the chefs felt the fume overflow from the exhaust hood during the cooking process, 83.33% of the chefs could sense the fume in the cooking area, and 69.41% of the chefs felt the noise generated by the exhaust fume system.
4. The exhaust fume system of the canteen kitchen was operated under the air velocity of 9.18 \(\pm\) 1.60 m/s, and its exhaust airflow rate was 10,634.80 \(\pm\) 189.30 m\({}^{3}\)/h, which was lower than the minimum exhaust airflow rate of 12,312 m\({}^{3}\)/h. This was probably the reason why the chefs felt the fume overflow from the exhaust hood.  
From the general view, the indoor environment of the canteen kitchen is too hot in summer, and the fume overflow from the exhaust hood and the chefs expose to higher air velocity during cooking. The measurement results indicate that the exhaust fume system could not remove the waste heat and fume pollutants effectively.  
Conceptualization, N.D. and Y.L.; Data curation, M.F. and R.H.; Investigation, M.F.; Methodology, M.F.; Supervision, N.D.; Writing--original draft, M.F.; Writing--review and editing, N.D., Y.L., M.F. and A.Z. All authors have read and agreed to the published version of the manuscript. The research was supported by the National Key Research and Development Program of China (No. 2017 YFC0211502). Not applicable. Not applicable. Not applicable. Data Availability Statement: The data presented in this study are available in the article. The authors declare no conflict of interest.
# An Improved YOLO Model for Traffic Signs Small Target Image Detection
## 3 Improvement of the YOLOv5s Algorithm
### Decoupled Head  
In the field of object detection, the shared branch between the classification and regression tasks in the YOLOv5 head is well-recognized as a problem that can negatively impact the training process, given the relatively low correlation between classification scores and localization accuracy. To address this issue, the decoupled head for classification and localization has become widely adopted in most one-stage and two-stage detectors. However, as the backbones and feature pyramids of YOLO series detectors, such as Feature Pyramid Networks (FPN) [32] and Path Aggregation Networks (PAN), continue to evolve, their detection heads remain coupled. The coupled detection head in YOLOv5 can limit performance improvements, as it can introduce noise in the error signal during backpropagation. By decoupling the detection head, the model can independently learn features, leading to improved accuracy, robustness, and generalization capabilities.  
Several experiments in the literature [26] have demonstrated that using coupled detection heads can lead to a decrease in performance, with a reduction in the end-to-end property of 4.2% AP. In contrast, when using decoupled detection heads, the decrease in AP is only 0.8%. To address this issue and improve the performance of YOLOv5, researchers have replaced the detection head with a simplified decoupled head, as illustrated in Figure 4. Specifically, this decoupled head consists of a 1 \(\times\) 1 convolutional layer that reduces the channel dimension, followed by two parallel branches, each with two 3 \(\times\) 3 convolutional  
Figure 3: Illustration of SPD-Conv when scale = 2.  
layers. These changes improve the accuracy and robustness of YOLOv5 models, even as the backbones and feature pyramids continue to evolve.  
In the new decoupled head, each branch has a smaller receptive field and fewer parameters, which help reduce overfitting. Additionally, the parallel design allows the head to learn features that are independent of each other, making the model more versatile and adaptable to different applications. The decoupled head also facilitates feature reuse, leading to more efficient computation.  
Overall, this modification provides a promising approach for improving object detection models, particularly in critical applications such as autonomous driving and surveillance. The decoupled head has been shown to enhance the accuracy and robustness of YOLOv5 models, making it an effective tool for real-world scenarios.
# A Review: Machine Learning for Combinatorial Optimization Problems in Energy Areas
## 2 Background
### Reinforcement Learning
#### 2.3.2 Multi-Agent Reinforcement Learning  
Multi-agent RL (MARL) is a sub-field of RL that is becoming increasingly relevant and is extremely impressive. Considering that there exist more than one agent in the systems over enormous applications, such as communication networks [206; 207], cyber-physical systems [208; 209], financial activities [210; 211], and social communities [212], research individuals and groups have started to transfer single-agent RL (SARL) models to the MARL ones. An obvious distinction between SARL and MARL is the number of agents in the environment. Hence, the research objective on MARL is to investigate how multiple agents are going to interact with each other in a common system and how this system evolves [213]. Specifically, the goal of each agent in this multi-agent system is, by treating other agents as part of the environment, to constantly optimize its policy for maximizing the expected long-term rewards.  
According to the types of agents, MARL can be generally divided into homogeneous MARL [214], where all agents in the system are homogeneous and able to play an interchangeable role, and heterogeneous MARL [215], in which agents possess different action space and state space.
## 3 Proposed Three-Phase Energy Mutual-Aid Strategy of a Grid-Connected Inverter
### Three-Phase Energy Mutual-Aid Strategy Aiming at Three-Phase Voltage Balance  
The control strategy described above is a lower-level control strategy, aimed at realizing three-phase energy flowing to each other. The amount of energy that is needed to flow among phases is decided by an upper-lower strategy. This section provides an example of an upper-lower strategy, aimed at three-phase voltage balance.  
In practical application, a distribution network which needs three-phase energy mutual aid often has three-phase voltage unbalance. Based on this scenario, this section proposes a three-phase energy mutual-aid strategy aiming at three-phase voltage balance.  
In a distribution network, as shown in Figure 8, assume that the voltage at the head of the line is three-phase balanced. However, since the loads P\({}_{\text{LA}}\), P\({}_{\text{LB}}\), and P\({}_{\text{LC}}\) of the ABC three phases are different and act on the same line impedance \(Z_{\text{grid}}\), the RMS values of the three-phase voltage at the tail of the line V\({}_{\text{A},\text{rms}}\), V\({}_{\text{B},\text{rms}}\), V\({}_{\text{C},\text{rms}}\) are different, in other words, three-phase voltage unbalance occurs. For example, if P\({}_{\text{LA}}\) is significantly larger than P\({}_{\text{LB}}\) and P\({}_{\text{LC}}\), then V\({}_{\text{A},\text{rms}}\) would be lower than V\({}_{\text{B},\text{rms}}\) and V\({}_{\text{C},\text{rms}}\). Therefore, it is necessary for the grid-connected inverter to increase the grid current of Phase A and reduce the grid current of Phases B and C to achieve three-phase voltage balance by means of three-phase energy mutual aid.  
The specific steps are as follows: Define the average of the RMS values of three-phase voltages as V\({}_{\text{rms},\text{avg}}\), shown in control block Figure 9. When V\({}_{\text{rms},\text{avg}}\) is greater than the RMS value of a certain phase, the current output of this phase is increased separately by PI control. The ultimate goal of this strategy is to ensure the RMS values of three-phase voltages V\({}_{\text{A},\text{rms}}\), V\({}_{\text{B},\text{rms}}\), and V\({}_{\text{C},\text{rms}}\) are all equal to the average of RMS values V\({}_{\text{rms},\text{avg}}\), in other words, to achieve three-phase voltage balance.  
Figure 8: Three-phase voltage unbalance caused by three-phase power unbalance.  
Figure 9: Three-phase energy mutual-aid strategy aimed at three-phase voltage balance.
## 4 Active Antiresonance Assignment with No Additional Masses
### The Fully-Active, Virtual Active Tuned Mass Damper  
The TMDs discussed so far in Section 3 introduce at least one additional DOF in the system due to the mass of the TMD. A different approach in the design of ATMDs is the so-called virtual ATMD, VATMD, which emulates, in a fully-active framework, the force \(u(\mathbf{t})\) that the passive TMD (sketched in Figure 13) would exert on the main system without any passive mass, dampers or springs. The operating principle has been first proposed in [44]. The idea can be easily explained through a virtual undamped TMD, the actuator force emulates the elastic forces transmitted to the primary system by the spring:  
\[u(t)=-k_{c}(q(t)-q_{a}(t)) \tag{34}\]  
where \(q_{a}(t)\) emulates the displacement of the mass of classical, undamped, passive TMD:  
\[m_{c}\tilde{q}_{a}(t)=k_{c}(q(t)-q_{a}(t)) \tag{35}\]  
Hence, the control action in the frequency domain \(s=j\omega\) is:  
\[u(s)=\frac{-k_{c}m_{c}s^{2}}{m_{c}s^{2}+k_{c}}q(s) \tag{36}\]  
The mass and stiffness of the VATMD are, in practice, tuning parameters. This idea can be also extended to include damping in Equation (35), with the aim of increasing robustness, as done in passive TMDs.  
The concept of VATMD has been further extended in [44] to emulate more complicate and effective TMDs. For example, the absorption of vibration during the transient can be achieved by emulating a TMD made by a series of two equal masses connected through a virtual linear damper and linked to the primary system (the first one) and the ground  
Figure 12: The steady-state response of the open-loop and closed-loop system (**a**) and the control force with the _mldivide_ gains (**b**).  
Figure 13: Sketch of the single-DOF VATMD.  
(the second one) through two equal springs. This arrangement is denoted as the virtual symmetric absorber; more symmetric absorbers can be also employed to enhance the performances. In the same paper, the virtual symmetric absorber has been applied to more challenging systems such as a multi-DOF structures, nonlinear systems, open-loop unstable systems, and to an inverted-pendulum subjected to actuator constraints.  
The virtual TMD with variable stiffness is analyzed in [78] to enhance the robustness whenever it is applied to systems with time-varying harmonic excitations. The adaptation algorithm consists of a phase detector with a low-pass filter.  
The idea of the VATMD control logic has been recently extended to damp the vibrational modes too, in [79], leading to the active modal tuned mass damper (AMTMD) where each VATMD is tuned to damper a specific vibrational mode of the controlled structure. To keep the controlled modes decoupled, the number of actuators must match the number of modes to be controlled, and a control action similar to the one in Equations (35) and (36), plus damping terms, is obtained.
## 1 Introduction
However, route preferences and historical travel routes are sensitive information that can be potentially leaked even if anonymous identities are used in blockchains. As for the anonymity paradox of Bitcoin, though every Bitcoin account is anonymous, identity information can still be leaked through transaction pattern analysis because every transaction is transparent. The historical travel routes associated with an account can be used to deduce that user's travel pattern and potentially leak their real-world identity. Therefore, on-chain computation alone does not enable a privacy-preserving incentive mechanism for collaborative routing. Secure multi-party computation (MPC) is a subfield of cryptography which allows a group to jointly compute a function without disclosing any participants' private inputs. A few studies [28; 29] leverage MPC in intelligent transportation systems to address privacy concerns. However, none of them address its potential for collaborative routing. To address privacy concerns in collaborative routing for CVs, this study first proposes a privacy-preserving incentive mechanism based on the decentralized mechanism developed in our previous work [21]. Specifically, a collaborative routing scheme is developed to enable travelers to update routes and compute associated incentives following an MPC protocol without disclosing their value of time. Then, a blockchain-based route validation scheme is proposed to securely validate travelers' whereabouts at checkpoints along selected routes with the assistance of nearby vehicles (i.e., witness vehicles) while allowing them to conceal their trajectories in the blockchain. Combining on-chain and off-chain cryptographic protocols, the proposed incentive mechanism protects sensitive personal information throughout peer vehicle collaborations and prevents malicious parties from conducting pattern-analysis attacks on the blockchain, ensuring that the entire collaborative routing process adheres to a high standard of privacy. It is worth noting that the privacy concerns mentioned earlier are not specifically associated with the collaborative routing strategy presented in [21]. Rather, they stem from the inherent nature of personalization. To effectively account for the diverse heterogeneities of individual users, personalization necessitates the incorporation of users' unique characteristics and preferences to generate tailored outputs that cater to their specific interests. Consequently, while [21] primarily addresses the computational efficiency of enabling personalization within the routing context, the current study emphasizes the implementation of structured privacy protection techniques to mitigate the privacy challenges associated with personalization. The rest of the paper is organized as follows. Section 2 provides an overview of the proposed incentive mechanism. Section 3 presents detailed protocols of the mechanism. Section 4 discusses numerical studies. Section 5 concludes the paper by summarizing contributions and future directions.
## 5 Conclusions  
In this paper, an inter-turn fault diagnosis algorithm is proposed based on impedance analysis and space voltage vector control for IMD systems. The terminal impedances when an inter-turn fault occurs in phase A are analyzed, revealing specific maximum and minimum impedance patterns with both Y and \(\Delta\) connections. The space voltage vectors of a three-phase inverter are also analyzed according to the switching states of each phase. A fault diagnosis algorithm is proposed by associating the terminal connections with the phases of the space voltage vector. An experimental setup, including a 12 kW three-phase induction motor from RENAULT TWIZY and a terminal box for winding connections, was implemented to validate the proposed algorithm. The impedances for each space voltage  
Figure 11: Experiment results for Y connection: (**a**) healthy; (**b**) fault phase A; (**c**) fault phase B; (**d**) fault phase C.  
Figure 12: Experiment results for \(\Delta\) connection: (**a**) healthy; (**b**) fault phase A; (**c**) fault phase B; (**d**) fault phase C.  
vector were calculated using a DSP (TMS320F28069) based on measured current and voltage and they were displayed on the oscilloscope using the processor's DAC. Inter-turn faults and various winding connections were implemented through the terminal box to emulate different fault conditions. The proposed diagnosis algorithm was verified through the experimental results for faults in each phase for both Y and \(\Delta\) connections, and the fault diagnosis was conducted within 3.5 s. This approach provides a practical and reliable solution for fault detection in highly integrated EV drive systems where mechanical access to motor terminals is restricted. Furthermore, the proposed ITF diagnosis does not require prior information about the electrical machine, such as healthy impedance, as it relies on the maximum and minimum impedance values associated with six space voltage vectors. Future research will focus on analyzing the frequency dependence of measured impedance to determine the optimal frequency range for reliable fault detection. To enhance diagnostic robustness, meta-heuristic techniques, such as genetic algorithms for optimization and support vector machines for classification, will also be investigated.  
Conceptualization, J.A. and H.K.; methodology, H.K.; software, J.A.; validation, J.A. and H.K.; formal analysis, H.K.; investigation, J.A.; resources, J.L.; data curation, J.A.; writing--original draft preparation, J.A. and H.K.; writing--review and editing, J.L. and H.K.; visualization, J.A.; supervision, J.L. and H.K.; project administration, H.K.; funding acquisition, J.L. All authors have read and agreed to the published version of the manuscript.  
This work was supported by the Korea Institute of Energy Technology Evaluation and Planning (KETEP) grant funded by the Korea government (MOTIE) (RS-2023-00237024, Development and demonstration of medium-sized variable speed high-power motor).  
Not applicable.  
Data Availability Statement: Data are contained within the article.  
The authors declare no conflicts of interest.
## 3 Field Tests and Results
### Deep-Hole Blasting for Hard-Roof Pre-Splitting  
Deep-hole pre-splitting blasting was applied to destroy the hard roof structure in advance of AR 4106 and prior to mining WF 4105 to optimize the surrounding rock stress environment. The deep-hole blasting scheme is as follows:  
(1) The holes were cut in the roof of the coal pillar side of AR 4106. The opening position was 1.5 m from the coal pillar side and the final hole was in the coal pillar. The drilling arrangement is shown in Figure 8.  
(2) The construction parameters of deep-hole blasting. (a) Borehole azimuth: 90\({}^{\circ}\). (b) Borehole inclination: 40\({}^{\circ}\). (c) Aperture: 75 mm. (d) Length: 44 m. (e) Hole spacing: 10 m. (f) Charging length: 24 m/60 section. (g) Charge quantity: 66 kg. (h) Hole sealing length: 20 m.  
(3) Charge and detonation. (a) Construction machinery: ZDY-4000 LR B-type full hydraulic tunnel drill for coal mining. (b) Explosives: Class-III permissible emulsion tube explosive for coal mining. The cartridge was 60 mm in diameter, 400 mm in length, and  
Figure 8: Schematic diagram of borehole location of deep-hole pre-splitting blasting.  
Figure 7: Main support section of flexible bolt.  
weighed 1.1 kg/ roll. (c) The forward charge used a series connection of detonating cord + detonator + detonator to connect the initiation.