Journal of Graphics ›› 2025, Vol. 46 ›› Issue (6): 1233-1246.DOI: 10.11996/JG.j.2095-302X.2025061233
• Core Industrial Software for Manufacturing Products • Previous Articles Next Articles
BO Wen1,2(
), JU Chen2, LIU Weiqing3, ZHANG Yan4, HU Jingjing1, CHENG Jinghan2, ZHANG Changyou2(
)
Received:2025-09-10
Accepted:2025-11-04
Online:2025-12-30
Published:2025-12-27
Contact:
ZHANG Changyou
About author:First author contact:BO Wen (1995-),PhD candidate. His main research interests cover system simulation and industrial intelligence. E-mail:bowen@iscas.ac.cn
Supported by:CLC Number:
BO Wen, JU Chen, LIU Weiqing, ZHANG Yan, HU Jingjing, CHENG Jinghan, ZHANG Changyou. Degradation-driven temporal modeling method for equipment maintenance interval prediction[J]. Journal of Graphics, 2025, 46(6): 1233-1246.
Add to citation manager EndNote|Ris|BibTeX
URL: http://www.txxb.com.cn/EN/10.11996/JG.j.2095-302X.2025061233
| 编号 | 参数 |
|---|---|
| S1 | 刀盘滚动角 |
| S2 | 电机电流 |
| S3 | 掘进速度 |
| S4 | 穿透力 |
| S5 | 贯入度 |
| S6 | 姿态水平(尾) |
| S7 | 刀盘转速 |
| S8 | 刀盘转矩 |
| S9 | 姿态垂直(尾) |
| S10 | 姿态垂直(首) |
| S11 | 推进推力 |
| S12 | 姿态水平(首) |
| S13 | 左侧夹持器的杆侧压力 |
| S14 | 右侧夹持器的杆侧压力 |
Table 1 TBM dataset of sensors information
| 编号 | 参数 |
|---|---|
| S1 | 刀盘滚动角 |
| S2 | 电机电流 |
| S3 | 掘进速度 |
| S4 | 穿透力 |
| S5 | 贯入度 |
| S6 | 姿态水平(尾) |
| S7 | 刀盘转速 |
| S8 | 刀盘转矩 |
| S9 | 姿态垂直(尾) |
| S10 | 姿态垂直(首) |
| S11 | 推进推力 |
| S12 | 姿态水平(首) |
| S13 | 左侧夹持器的杆侧压力 |
| S14 | 右侧夹持器的杆侧压力 |
| 数据集 | TBM-1 | TBM-2 |
|---|---|---|
| 训练样本数量 | 10423 | 11126 |
| 测试样本数量 | 428 | 5784 |
| 训练周期数 | 173 | 196 |
| 测试周期数 | 126 | 139 |
Table 2 TBM dataset information
| 数据集 | TBM-1 | TBM-2 |
|---|---|---|
| 训练样本数量 | 10423 | 11126 |
| 测试样本数量 | 428 | 5784 |
| 训练周期数 | 173 | 196 |
| 测试周期数 | 126 | 139 |
| 模型 | MAE | RMSE |
|---|---|---|
| LSTM | 11.57 | 16.21 |
| RNN | 10.03 | 14.01 |
| Attention+LSTM | 10.50 | 14.83 |
| Ours | 9.32 | 12.14 |
Table 3 Experiment results of TBM dataset
| 模型 | MAE | RMSE |
|---|---|---|
| LSTM | 11.57 | 16.21 |
| RNN | 10.03 | 14.01 |
| Attention+LSTM | 10.50 | 14.83 |
| Ours | 9.32 | 12.14 |
| 模型 | MAE | RMSE |
|---|---|---|
| Ours without PDI | 9.78 | 13.78 |
| LSTM+PDI | 10.67 | 14.53 |
| RNN+PDI | 9.92 | 13.52 |
| Attention+LSTM +PDI | 9.83 | 13.35 |
Table 4 PDI index ablation experiment results
| 模型 | MAE | RMSE |
|---|---|---|
| Ours without PDI | 9.78 | 13.78 |
| LSTM+PDI | 10.67 | 14.53 |
| RNN+PDI | 9.92 | 13.52 |
| Attention+LSTM +PDI | 9.83 | 13.35 |
| 编号 | 符号 | 描述 |
|---|---|---|
| S1 | T2 | 风机入口总温度 |
| S2 | T24 | 低压压气机出口总温度 |
| S3 | T30 | 高压压气机出口总温度 |
| S4 | T50 | 低压涡轮出口的总温度 |
| S5 | P2 | 风机入口压力 |
| S6 | P15 | 旁通管道中的总压力 |
| S7 | P30 | 高压压缩机出口总压力 |
| S8 | Nf | 物理风扇转速 |
| S9 | Nc | 物理核心速度 |
| S10 | epr | 发动机压力比 |
Table 5 CMPASS dataset of sensors information
| 编号 | 符号 | 描述 |
|---|---|---|
| S1 | T2 | 风机入口总温度 |
| S2 | T24 | 低压压气机出口总温度 |
| S3 | T30 | 高压压气机出口总温度 |
| S4 | T50 | 低压涡轮出口的总温度 |
| S5 | P2 | 风机入口压力 |
| S6 | P15 | 旁通管道中的总压力 |
| S7 | P30 | 高压压缩机出口总压力 |
| S8 | Nf | 物理风扇转速 |
| S9 | Nc | 物理核心速度 |
| S10 | epr | 发动机压力比 |
| 方法名称 | FD001 | FD002 | FD003 | FD004 | ||||
|---|---|---|---|---|---|---|---|---|
| RMSE | Score | RMSE | Score | RMSE | Score | RMSE | Score | |
| Hybrid | 14.53 | 322 | 21.37 | 3077 | 13.24 | 367 | 27.08 | 5649 |
| MODBNE | 15.04 | 334 | 25.05 | 5585 | 12.51 | 421 | 28.66 | 6557 |
| AConvLSTM | 13.10 | 262 | 14.11 | 737 | 12.13 | 276 | 14.64 | 1011 |
| KDNet | 13.68 | 362 | 12.95 | 929 | 12.95 | 327 | 15.96 | 1303 |
| GCN | 12.58 | 237 | 13.78 | 849 | 11.92 | 218 | 14.44 | 967 |
| AutoFormer | 23.04 | 1063 | 16.51 | 1248 | 25.40 | 2034 | 20.30 | 2291 |
| DAGN | 16.11 | 595 | 16.43 | 1242 | 18.05 | 1216 | 19.04 | 2321 |
| CNN-LSTM | 12.47 | 257 | 15.02 | 835 | 12.42 | 252 | 14.49 | 870 |
| SCTA-LSTM | 12.10 | 207 | 16.90 | 1267 | 12.14 | 248 | 21.93 | 3310 |
| GAT-DAT | 13.83 | 319 | 14.85 | 1163 | 14.85 | 438 | 16.80 | 1928 |
| Ours | 12.02 | 204 | 12.86 | 835 | 11.92 | 215 | 13.74 | 838 |
Table 6 Comparison of C-MAPSS results from different representative algorithms
| 方法名称 | FD001 | FD002 | FD003 | FD004 | ||||
|---|---|---|---|---|---|---|---|---|
| RMSE | Score | RMSE | Score | RMSE | Score | RMSE | Score | |
| Hybrid | 14.53 | 322 | 21.37 | 3077 | 13.24 | 367 | 27.08 | 5649 |
| MODBNE | 15.04 | 334 | 25.05 | 5585 | 12.51 | 421 | 28.66 | 6557 |
| AConvLSTM | 13.10 | 262 | 14.11 | 737 | 12.13 | 276 | 14.64 | 1011 |
| KDNet | 13.68 | 362 | 12.95 | 929 | 12.95 | 327 | 15.96 | 1303 |
| GCN | 12.58 | 237 | 13.78 | 849 | 11.92 | 218 | 14.44 | 967 |
| AutoFormer | 23.04 | 1063 | 16.51 | 1248 | 25.40 | 2034 | 20.30 | 2291 |
| DAGN | 16.11 | 595 | 16.43 | 1242 | 18.05 | 1216 | 19.04 | 2321 |
| CNN-LSTM | 12.47 | 257 | 15.02 | 835 | 12.42 | 252 | 14.49 | 870 |
| SCTA-LSTM | 12.10 | 207 | 16.90 | 1267 | 12.14 | 248 | 21.93 | 3310 |
| GAT-DAT | 13.83 | 319 | 14.85 | 1163 | 14.85 | 438 | 16.80 | 1928 |
| Ours | 12.02 | 204 | 12.86 | 835 | 11.92 | 215 | 13.74 | 838 |
| 数量 | FD001 | FD002 | FD003 | FD004 | ||||
|---|---|---|---|---|---|---|---|---|
| RMSE | Score | RMSE | Score | RMSE | Score | RMSE | Score | |
| 4 | 15.27 | 376 | 15.18 | 1181 | 15.59 | 610 | 16.37 | 1261 |
| 7 | 14.64 | 333 | 14.57 | 1109 | 14.02 | 334 | 15.49 | 1037 |
| 10 | 12.99 | 241 | 13.34 | 949 | 13.28 | 266 | 14.67 | 952 |
| 14 | 12.24 | 204 | 12.92 | 882 | 12.48 | 220 | 13.92 | 891 |
Table 7 Prediction results with different sensors
| 数量 | FD001 | FD002 | FD003 | FD004 | ||||
|---|---|---|---|---|---|---|---|---|
| RMSE | Score | RMSE | Score | RMSE | Score | RMSE | Score | |
| 4 | 15.27 | 376 | 15.18 | 1181 | 15.59 | 610 | 16.37 | 1261 |
| 7 | 14.64 | 333 | 14.57 | 1109 | 14.02 | 334 | 15.49 | 1037 |
| 10 | 12.99 | 241 | 13.34 | 949 | 13.28 | 266 | 14.67 | 952 |
| 14 | 12.24 | 204 | 12.92 | 882 | 12.48 | 220 | 13.92 | 891 |
| 策略 | FD001 | FD002 | FD003 | FD004 | ||||
|---|---|---|---|---|---|---|---|---|
| RMSE | Score | RMSE | Score | RMSE | Score | RMSE | Score | |
| 随机去除 | 14.64 | 333 | 14.57 | 1 109 | 14.02 | 334 | 15.49 | 1 037 |
| 去除低相关性 | 14.61 | 340 | 13.82 | 1 004 | 14.76 | 358 | 14.68 | 910 |
| 去除高相关性 | 13.67 | 317 | 15.99 | 1 398 | 13.85 | 453 | 17.57 | 1 455 |
| 高与低相关性去除 | 16.12 | 426 | 15.35 | 1 187 | 13.88 | 377 | 15.76 | 1 032 |
Table 8 Results of correlation screening strategy
| 策略 | FD001 | FD002 | FD003 | FD004 | ||||
|---|---|---|---|---|---|---|---|---|
| RMSE | Score | RMSE | Score | RMSE | Score | RMSE | Score | |
| 随机去除 | 14.64 | 333 | 14.57 | 1 109 | 14.02 | 334 | 15.49 | 1 037 |
| 去除低相关性 | 14.61 | 340 | 13.82 | 1 004 | 14.76 | 358 | 14.68 | 910 |
| 去除高相关性 | 13.67 | 317 | 15.99 | 1 398 | 13.85 | 453 | 17.57 | 1 455 |
| 高与低相关性去除 | 16.12 | 426 | 15.35 | 1 187 | 13.88 | 377 | 15.76 | 1 032 |
| 策略 | FD001 | FD002 | FD003 | FD004 | ||||
|---|---|---|---|---|---|---|---|---|
| RMSE | Score | RMSE | Score | RMSE | Score | RMSE | Score | |
| 单头注意力 | 13.13 | 270 | 12.96 | 880 | 12.87 | 228 | 14.29 | 969 |
| 多头注意力 | 12.24 | 204 | 12.92 | 882 | 12.48 | 220 | 13.92 | 891 |
Table 9 Rresults of different attention mechanisms
| 策略 | FD001 | FD002 | FD003 | FD004 | ||||
|---|---|---|---|---|---|---|---|---|
| RMSE | Score | RMSE | Score | RMSE | Score | RMSE | Score | |
| 单头注意力 | 13.13 | 270 | 12.96 | 880 | 12.87 | 228 | 14.29 | 969 |
| 多头注意力 | 12.24 | 204 | 12.92 | 882 | 12.48 | 220 | 13.92 | 891 |
Fig. 10 Effect diagram of TBM multimodal time-series data information collection ((a) Surrounding rock geological type, particle distribution quantity; (b) Rock debris size; (c) Rock debris volume)
| [1] | HUANG X, CHEN W W, QU D R, et al. Remaining useful life prediction method based on multisensor fusion under time-varying operating conditions[J]. IEEE Transactions on Instrumentation and Measurement, 2024, 73: 3516413. |
| [2] | JAVID A, ZARKESH M, BOROUMAND Y, AL-FAWA’REH M. Enhancing safety and minimizing risk in mining processes with artificial intelligence[M]//RAZMJOU A, ASADNIA M, eds. Artificial Intelligence in Future Mining. Cambridge: Academic Press, 2025: 355-382. |
| [3] |
WEST J, SIDDHPURA M, EVANGELISTA A, HADDAD A. Improving equipment maintenance—switching from corrective to preventative maintenance strategies[J]. Buildings, 2024, 14: 3581.
DOI URL |
| [4] |
鲜思渔, 赵泽田, 吴轩宇, 等. 基于改进红鸢优化算法与LSTM的核电换热器寿命预测方法[J]. 图学学报, 2025, 46(5): 1085-1093.
DOI |
|
XIAN S Y, ZHAO Z T, WU X Y, et al. Life prediction method of nuclear power heat exchanger based on improved red kite optimization algorithm and LSTM[J]. Journal of Graphics, 2025, 46(5): 1085-1093 (in Chinese).
DOI |
|
| [5] |
EANG C, LEE S. Predictive maintenance and fault detection for motor drive control systems in industrial robots using CNN-RNN-based observers[J]. Sensors, 2025, 25(1): 25.
DOI URL |
| [6] |
GE R H, ZHAI Q Q, WANG H, et al. Wiener degradation models with scale-mixture normal distributed measurement errors for RUL prediction[J]. Mechanical Systems and Signal Processing, 2022, 173: 109029.
DOI URL |
| [7] |
LI Z, ZHU R, VERWIMP T, et al. Estimation of remaining useful life of rolling element bearings based on the adaptive kernel Kalman filter[J]. Mechanical Systems and Signal Processing, 2025, 229: 112493.
DOI URL |
| [8] |
KUNDU P, DARPE A K, KULKARNI M S. Weibull accelerated failure time regression model for remaining useful life prediction of bearing working under multiple operating conditions[J]. Mechanical Systems and Signal Processing, 2019, 134: 106302.
DOI URL |
| [9] |
ZHU K P, LI X, LI S S, et al. Physics-informed hidden Markov model for tool wear monitoring[J]. Journal of Manufacturing Systems, 2024, 72: 308-322.
DOI URL |
| [10] |
GARCIA J, RIOS-COLQUE L, PEÑA A, et al. Condition monitoring and predictive maintenance in industrial equipment: an NLP-assisted review of signal processing, hybrid models, and implementation challenges[J]. Applied Sciences, 2025, 15(10): 5465.
DOI URL |
| [11] | LIN T T, REN Z J, ZHU L B, et al. A systematic review of multi-sensor information fusion for equipment fault diagnosis[EB/OL]. [2025-07-10]. https://ieeexplore.ieee.org/abstract/document/10840346. |
| [12] |
DONG S J, XIAO J F, HU X L, et al. Deep transfer learning based on Bi-LSTM and attention for remaining useful life prediction of rolling bearing[J]. Reliability Engineering & System Safety, 2023, 230: 108914.
DOI URL |
| [13] |
WAN A P, ZHANG H, CHEN T, et al. Aeroengine life prediction and status evaluation based on sequential multitask learning and health indicators[J]. IEEE Transactions on Reliability, 2025, 74(3): 3833-3846.
DOI URL |
| [14] |
LIU L, SONG X, ZHOU Z T. Aircraft engine remaining useful life estimation via a double attention-based data-driven architecture[J]. Reliability Engineering & System Safety, 2022, 221: 108330.
DOI URL |
| [15] | SUTSKEVER I, VINYALS O, LE Q V. Sequence to sequence learning with neural networks[C]// The 28th International Conference on Neural Information Processing Systems. Cambridge: MIT Press, 2014: 3104-3112. |
| [16] | VASWANI A, SHAZEER N, PARMAR N, et al. Attention is all you need[C]// The 31st International Conference on Neural Information Processing Systems. Red Hook: Curran Associates Inc., 2017: 6000-6010. |
| [17] |
吴沛宸, 袁立宁, 胡皓, 等. 基于注意力特征融合的视频异常行为检测[J]. 图学学报, 2024, 45(5): 922-929.
DOI |
|
WU P C, YUAN L N, HU H, et al. Video anomaly detection based on attention feature fusion[J]. Journal of Graphics, 2024, 45(5): 922-929 (in Chinese).
DOI |
|
| [18] |
AWAISI K S, YE Q, SAMPALLI S. A survey of industrial AIoT: opportunities, challenges, and directions[J]. IEEE Access, 2024, 12: 96946-96996.
DOI URL |
| [19] |
何庆, 荆传玉, 孙华坤, 等. 基于BIM和语义网的轨道智能运维管理方法[J]. 图学学报, 2024, 45(3): 601-612.
DOI |
|
HE Q, JING C Y, SUN H K, et al. An intelligent railway operation and maintenance management approach based on BIM and semantic web[J]. Journal of Graphics, 2024, 45(3): 601-612 (in Chinese).
DOI |
|
| [20] | ZHANG Q, LIU J, LIU Q. A novel multi-source domain transfer learning method for remaining useful life prediction using multi-scale attention-based temporal convolutional network[C]// The 30th International Conference on Mechatronics and Machine Vision in Practice. New York: IEEE Press, 2024: 1-5. |
| [21] |
REN H J, DAI Z X, CHEN J X, et al. Natural gas triethylene glycol dehydration equipment digital twin and condition evaluation application[J]. IEEE Transactions on Industrial Informatics, 2024, 20(10): 12147-12156.
DOI URL |
| [22] |
XIAO X Q, LI C S, HE H X, et al. Rotating machinery fault diagnosis method based on multi-level fusion framework of multi-sensor information[J]. Information Fusion, 2025, 113: 102621.
DOI URL |
| [23] |
MIKOŁAJEWSKA E, MIKOŁAJEWSKI D, MIKOŁAJCZYK T, et al. Generative AI in AI-based digital twins for fault diagnosis for predictive maintenance in industry 4.0/5.0[J]. Applied Sciences, 2025, 15(6): 3166.
DOI URL |
| [24] |
ABED A I, PING L W. Implementing data mining techniques for gas-turbine (GT) health tracking and life management: the bibliographic perspective[J]. Expert Systems with Applications, 2024, 252: 124077.
DOI URL |
| [25] |
WANG X Q, LIU M Z, LIU C H, et al. Data-driven and knowledge-based predictive maintenance method for industrial robots for the production stability of intelligent manufacturing[J]. Expert Systems with Applications, 2023, 234: 121136.
DOI URL |
| [26] |
LI Y S, ZHOU Z, HU C Y, et al. Sequence to sequence network with Bayesian attention and state transition for self-data-driven remaining useful life estimation[J]. Expert Systems with Applications, 2025, 286: 128165.
DOI URL |
| [27] |
LU O H T. A Seq2Seq transformation strategy for generalizing a pre-trained model in anomaly detection of rolling element bearings[J]. Expert Systems with Applications, 2024, 254: 124297.
DOI URL |
| [28] |
ZHANG T C, FU T, NI T, et al. Data-driven excavation trajectory planning for unmanned mining excavator[J]. Automation in Construction, 2024, 162: 105395.
DOI URL |
| [29] |
XU D, XIAO X Q, LIU J, et al. Spatio-temporal degradation modeling and remaining useful life prediction under multiple operating conditions based on attention mechanism and deep learning[J]. Reliability Engineering & System Safety, 2023, 229: 108886.
DOI URL |
| [30] |
ZHANG Y, LI C B, SU L, et al. Degradation trend prediction for centrifugal blowers based on multi-sensor information fusion and attention mechanism[J]. Expert Systems with Applications, 2025, 276: 127195.
DOI URL |
| [31] |
WANG Y W, DENG L, ZHENG L Y, et al. Temporal convolutional network with soft thresholding and attention mechanism for machinery prognostics[J]. Journal of Manufacturing Systems, 2021, 60: 512-526.
DOI URL |
| [32] |
XIAO Y T, YIN H S, ZHANG Y D, et al. A dual-stage attention-based Conv-LSTM network for spatio-temporal correlation and multivariate time series prediction[J]. International Journal of Intelligent Systems, 2021, 36(5): 2036-2057.
DOI URL |
| [33] |
YANG T G, LI G C, LI K T, et al. The LPST-Net: a new deep interval health monitoring and prediction framework for bearing-rotor systems under complex operating conditions[J]. Advanced Engineering Informatics, 2024, 62: 102558.
DOI URL |
| [1] | JU Chen, DING Jiaxin, WANG Zexing, LI Guangzhao, GUAN Zhenxiang, ZHANG Changyou. Graph neural network-based method for approximating finite element shape functions [J]. Journal of Graphics, 2025, 46(6): 1161-1171. |
| [2] | YI Bin, ZHANG Libin, LIU Danying, TANG Jun, FANG Junjun, LI Wenqi. Prediction model of laser drilling ventilation rate in cigarette manufacturing process based on AMTA-Net [J]. Journal of Graphics, 2025, 46(6): 1224-1232. |
| [3] | ZHAO Zhenbing, Ouyang Wenbin, FENG Shuo, LI Haopeng, MA Jun. A thermal image detection method for insulators incorporating within-class sparse prior knowledge and improved YOLOv8 [J]. Journal of Graphics, 2025, 46(6): 1247-1256. |
| [4] | HE Mengmeng, ZHANG Xiaoyan, LI Hongan. Lightweight skin lesion image segmentation network based on Mamba structure [J]. Journal of Graphics, 2025, 46(6): 1257-1266. |
| [5] | LI Xingchen, LI Zongmin, YANG Chaozhi. Test-time adaptation algorithm based on trusted pseudo-label fine-tuning [J]. Journal of Graphics, 2025, 46(6): 1292-1303. |
| [6] | FAN Lexiang, MA Ji, ZHOU Dengwen. Lightweight blind super-resolution network based on degradation separation [J]. Journal of Graphics, 2025, 46(6): 1304-1315. |
| [7] | WANG Haihan. Multi object detection method for surface defects of steel arch towers based on YOLOv8-OSRA [J]. Journal of Graphics, 2025, 46(6): 1327-1336. |
| [8] | ZHU Hongmiao, ZHONG Guojie, ZHANG Yanci. Semantic segmentation of small-scale point clouds based on integration of mean shift and deep learning [J]. Journal of Graphics, 2025, 46(5): 998-1009. |
| [9] | WANG Ziyu, CAO Weiwei, CAO Yuzhu, LIU Meng, CHEN Jun, LIU Zhaobang, ZHENG Jian. Semi-supervised pulmonary airway segmentation based on dynamically decoupling intra-class regions [J]. Journal of Graphics, 2025, 46(4): 763-774. |
| [10] | WANG Daolei, DING Zijian, YANG Jun, ZHENG Shaokai, ZHU Rui, ZHAO Wenbin. Large scene reconstruction method based on voxel grid feature of NeRF [J]. Journal of Graphics, 2025, 46(3): 502-509. |
| [11] | SUN Hao, XIE Tao, HE Long, GUO Wenzhong, YU Yongfang, WU Qijun, WANG Jianwei, DONG Hui. Research on multimodal text-visual large model for robotic terrain perception algorithm [J]. Journal of Graphics, 2025, 46(3): 558-567. |
| [12] | ZHAI Yongjie, WANG Luyao, ZHAO Xiaoyu, HU Zhedong, WANG Qianming, WANG Yaru. Multi-fitting detection for transmission lines based on a cascade query-position relationship method [J]. Journal of Graphics, 2025, 46(2): 288-299. |
| [13] | PAN Shuyan, LIU Liqun. MSFAFuse: sar and optical image fusion model based on multi-scale feature information and attention mechanism [J]. Journal of Graphics, 2025, 46(2): 300-311. |
| [14] | ZHANG Tiansheng, ZHU Minfeng, REN Yiwen, WANG Chenhan, ZHANG Lidong, ZHANG Wei, CHEN Wei. BPA-SAM: box prompt augmented SAM for traditional Chinese realistic painting [J]. Journal of Graphics, 2025, 46(2): 322-331. |
| [15] | SUN Heyi, LI Yixiao, TIAN Xi, ZHANG Songhai. Image to 3D vase generation technology combining procedural content generation and diffusion models [J]. Journal of Graphics, 2025, 46(2): 332-344. |
| Viewed | ||||||
|
Full text |
|
|||||
|
Abstract |
|
|||||