Pub Date : 2009-12-18DOI: 10.1109/ISIEA.2009.5356408
N. Intan, M. Amir, S. Sakrani, M. Afham, ICmic-UniKL Academy
The rapid growth in the microelectronics industry and the challenges increasing such as globalization, technological changes and specialization has brought about a demand for skill manpower. Therefore, the apprenticeship program in IC Design which provided a comprehensive training is really significant to the industry need. The apprenticeship program was conducted at ICmic-UniKL Academy which focuses on Microelectronics competency development for Malaysian in producing commercial Integrated Circuit (IC) products. Through this apprenticeship, apprentice was exposed to the hands-on job with entrepreneurial skills who can directly participate in microelectronics design and related industries thus closing the gap with industry requirement. A supervisory circuit with watchdog timer feature was highlighted to show one of the project carried out by the apprentice. At the end of this apprenticeship, the apprentice will able to master the skills and has necessary knowledge to become a highly competent and entrepreneurial design engineer.
{"title":"Grooming IC Designer through apprenticeship programme","authors":"N. Intan, M. Amir, S. Sakrani, M. Afham, ICmic-UniKL Academy","doi":"10.1109/ISIEA.2009.5356408","DOIUrl":"https://doi.org/10.1109/ISIEA.2009.5356408","url":null,"abstract":"The rapid growth in the microelectronics industry and the challenges increasing such as globalization, technological changes and specialization has brought about a demand for skill manpower. Therefore, the apprenticeship program in IC Design which provided a comprehensive training is really significant to the industry need. The apprenticeship program was conducted at ICmic-UniKL Academy which focuses on Microelectronics competency development for Malaysian in producing commercial Integrated Circuit (IC) products. Through this apprenticeship, apprentice was exposed to the hands-on job with entrepreneurial skills who can directly participate in microelectronics design and related industries thus closing the gap with industry requirement. A supervisory circuit with watchdog timer feature was highlighted to show one of the project carried out by the apprentice. At the end of this apprenticeship, the apprentice will able to master the skills and has necessary knowledge to become a highly competent and entrepreneurial design engineer.","PeriodicalId":6447,"journal":{"name":"2009 IEEE Symposium on Industrial Electronics & Applications","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2009-12-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"79330092","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2009-12-18DOI: 10.1109/ISIEA.2009.5356404
Michael McCarty, T. Taufik, Andre Pratama, M. Anwari
Harmonic analysis of input current of single phase uncontrolled rectifier is widely known. However, little has been known about harmonic of the input current of single phase controlled or thyristor rectifier. This paper presents such an analysis using the bridge configuration for the controlled rectifier circuit. Results obtained from mathematical derivation, computer simulation, and hardware measurements will also be discussed.
{"title":"Harmonic analysis of input current of single- phase controlled bridge rectifier","authors":"Michael McCarty, T. Taufik, Andre Pratama, M. Anwari","doi":"10.1109/ISIEA.2009.5356404","DOIUrl":"https://doi.org/10.1109/ISIEA.2009.5356404","url":null,"abstract":"Harmonic analysis of input current of single phase uncontrolled rectifier is widely known. However, little has been known about harmonic of the input current of single phase controlled or thyristor rectifier. This paper presents such an analysis using the bridge configuration for the controlled rectifier circuit. Results obtained from mathematical derivation, computer simulation, and hardware measurements will also be discussed.","PeriodicalId":6447,"journal":{"name":"2009 IEEE Symposium on Industrial Electronics & Applications","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2009-12-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"85518813","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2009-12-18DOI: 10.1109/ISIEA.2009.5356388
M. B. Bannae Sharifian, M. Abapour, E. Babaei
Since magnetic core of an inductor is easily saturated and then absorbs extra energy due to saturation, most of inductors are designed with an air core. The inductor requires so many wires to make large inductance and these expensive coils are one of the weak points of the dc reactor type fault current limiter (FCL). To solve this problem, reverse magnetization bias method is introduced. One kind of fault current limiter using dc biased saturated core has been studied in this paper. All exciting saturated cores are ac type. The proposed FCL is a dc reactor type where all the windings carry dc current. The B-H curve of a magnetic circuit shows that less inductance value can be achieved in saturated region and very high value in unsaturated region. The reactance window between the saturated and unsaturated region depends on magnetic material, core size and its biasing condition [1]. The complete mathematical analysis in different modes of operations of the proposed FCL is given. The simulation results are presented to validate its effectiveness.
{"title":"Design and study of a saturated dc reactor fault current limiter","authors":"M. B. Bannae Sharifian, M. Abapour, E. Babaei","doi":"10.1109/ISIEA.2009.5356388","DOIUrl":"https://doi.org/10.1109/ISIEA.2009.5356388","url":null,"abstract":"Since magnetic core of an inductor is easily saturated and then absorbs extra energy due to saturation, most of inductors are designed with an air core. The inductor requires so many wires to make large inductance and these expensive coils are one of the weak points of the dc reactor type fault current limiter (FCL). To solve this problem, reverse magnetization bias method is introduced. One kind of fault current limiter using dc biased saturated core has been studied in this paper. All exciting saturated cores are ac type. The proposed FCL is a dc reactor type where all the windings carry dc current. The B-H curve of a magnetic circuit shows that less inductance value can be achieved in saturated region and very high value in unsaturated region. The reactance window between the saturated and unsaturated region depends on magnetic material, core size and its biasing condition [1]. The complete mathematical analysis in different modes of operations of the proposed FCL is given. The simulation results are presented to validate its effectiveness.","PeriodicalId":6447,"journal":{"name":"2009 IEEE Symposium on Industrial Electronics & Applications","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2009-12-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"79464561","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2009-12-18DOI: 10.1109/ISIEA.2009.5356416
Omar Almomani, O. Ghazali, S. Hassan
In this paper, we report an investigation on performance of the forward error correction (FEC) with random early detection (RED) queuing policy. FEC is a technique that uses redundant packet to reconstruct the dropped packet, while RED is an active queue management algorithm. It monitors the average queue size and drops arriving packets probabilistically, the probability of drop increases as the estimated average queue size grows. In the investigation we consider simulation settings with varies size of the queue buffer. Results obtained from the simulation experiments show that FEC and queue size affect the performance the network. Consequently, the qualities of multimedia applications are also affected.
{"title":"Performance study of large block forward error correction with random early detection queue policy","authors":"Omar Almomani, O. Ghazali, S. Hassan","doi":"10.1109/ISIEA.2009.5356416","DOIUrl":"https://doi.org/10.1109/ISIEA.2009.5356416","url":null,"abstract":"In this paper, we report an investigation on performance of the forward error correction (FEC) with random early detection (RED) queuing policy. FEC is a technique that uses redundant packet to reconstruct the dropped packet, while RED is an active queue management algorithm. It monitors the average queue size and drops arriving packets probabilistically, the probability of drop increases as the estimated average queue size grows. In the investigation we consider simulation settings with varies size of the queue buffer. Results obtained from the simulation experiments show that FEC and queue size affect the performance the network. Consequently, the qualities of multimedia applications are also affected.","PeriodicalId":6447,"journal":{"name":"2009 IEEE Symposium on Industrial Electronics & Applications","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2009-12-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"79703697","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2009-12-18DOI: 10.1109/ISIEA.2009.5356427
Amideddin Mousavi, E. Rahimpour
One of the powerful methods by transformer transient analysis is traveling wave theory. Two important factors named reflection and transmission coefficients are defined in this method, so that the applying of theory is been easier. These coefficients are given usually in frequency domain with help of executing some tests on transformer. Since such tests are difficult, costly and even sometimes impossible, using a model to calculate the above mentioned coefficients is very helpful. This paper shows the validity of detailed model based on self and mutual inductances by calculating of these coefficients. A three phase 2.5 MVA and 6300/420 V transformer is used by this investigation.
{"title":"Determining the traveling wave coefficients in power transformers using detailed model","authors":"Amideddin Mousavi, E. Rahimpour","doi":"10.1109/ISIEA.2009.5356427","DOIUrl":"https://doi.org/10.1109/ISIEA.2009.5356427","url":null,"abstract":"One of the powerful methods by transformer transient analysis is traveling wave theory. Two important factors named reflection and transmission coefficients are defined in this method, so that the applying of theory is been easier. These coefficients are given usually in frequency domain with help of executing some tests on transformer. Since such tests are difficult, costly and even sometimes impossible, using a model to calculate the above mentioned coefficients is very helpful. This paper shows the validity of detailed model based on self and mutual inductances by calculating of these coefficients. A three phase 2.5 MVA and 6300/420 V transformer is used by this investigation.","PeriodicalId":6447,"journal":{"name":"2009 IEEE Symposium on Industrial Electronics & Applications","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2009-12-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"85358367","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2009-12-18DOI: 10.1109/ISIEA.2009.5356376
Hussnain Ali, T. J. Ahmad, S. Khan
This paper describes design principles to design and develop a transcutaneous link for medical implants using inductively coupled coils. Parameters which optimize link efficiency have been discussed in the light of previous studies and a simple design methodology to find optimized parameters for Class E amplifier and inductive coils is outlined. Paper also describes design of an indigenously developed transcutaneous link from commercial off-the-shelf components to demonstrate the design process. Simulation and practical results of the link developed at 2.5MHz for 100mW output power are provided. We were able to achieve 40% link efficiency with data rate of 128kbps from laboratory-based discrete electronic components.
{"title":"Inductive link design for medical implants","authors":"Hussnain Ali, T. J. Ahmad, S. Khan","doi":"10.1109/ISIEA.2009.5356376","DOIUrl":"https://doi.org/10.1109/ISIEA.2009.5356376","url":null,"abstract":"This paper describes design principles to design and develop a transcutaneous link for medical implants using inductively coupled coils. Parameters which optimize link efficiency have been discussed in the light of previous studies and a simple design methodology to find optimized parameters for Class E amplifier and inductive coils is outlined. Paper also describes design of an indigenously developed transcutaneous link from commercial off-the-shelf components to demonstrate the design process. Simulation and practical results of the link developed at 2.5MHz for 100mW output power are provided. We were able to achieve 40% link efficiency with data rate of 128kbps from laboratory-based discrete electronic components.","PeriodicalId":6447,"journal":{"name":"2009 IEEE Symposium on Industrial Electronics & Applications","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2009-12-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"80748546","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2009-12-18DOI: 10.1109/ISIEA.2009.5356371
E. Babaei, Ali Aghabeigi Heris
This paper presents a new control method for three-phase to single-phase cycloconverters based on pulse width modulation (PWM) technique. Due to the proposed control method, the desired output voltage can be generated even with unbalanced input voltages. The proposed control method can easily be extend to three-phase to n-phase cycloconverters. The theoretical analysis based on the proposed method is given for both of the conventional topologies of three-phase to single-phase cycloconverters. Using the proposed control method, the maximum output/input voltage transfer ratios for balanced operation are 0.5 and 1.5 for cycloconverters that consist of three and six bidirectional switches, respectively. It is important to note that the low voltage transfer ratio is an intrinsic limitation of the conventional control methods. This method has no limitation on frequency conversion and is independent of the load. In other words, using the proposed control method, the three-phase to single-phase cycloconverter can operate as a step-up voltage and frequency. The other advantage of this method is no low order harmonics in the input and output quantities. Therefore, the size of required filters is decreased. The operation and performance of the proposed control method has been verified by simulation and experimental results of a three-phase to single-phase cycloconverter.
{"title":"PWM-based control strategy for forced commutated cycloconverters","authors":"E. Babaei, Ali Aghabeigi Heris","doi":"10.1109/ISIEA.2009.5356371","DOIUrl":"https://doi.org/10.1109/ISIEA.2009.5356371","url":null,"abstract":"This paper presents a new control method for three-phase to single-phase cycloconverters based on pulse width modulation (PWM) technique. Due to the proposed control method, the desired output voltage can be generated even with unbalanced input voltages. The proposed control method can easily be extend to three-phase to n-phase cycloconverters. The theoretical analysis based on the proposed method is given for both of the conventional topologies of three-phase to single-phase cycloconverters. Using the proposed control method, the maximum output/input voltage transfer ratios for balanced operation are 0.5 and 1.5 for cycloconverters that consist of three and six bidirectional switches, respectively. It is important to note that the low voltage transfer ratio is an intrinsic limitation of the conventional control methods. This method has no limitation on frequency conversion and is independent of the load. In other words, using the proposed control method, the three-phase to single-phase cycloconverter can operate as a step-up voltage and frequency. The other advantage of this method is no low order harmonics in the input and output quantities. Therefore, the size of required filters is decreased. The operation and performance of the proposed control method has been verified by simulation and experimental results of a three-phase to single-phase cycloconverter.","PeriodicalId":6447,"journal":{"name":"2009 IEEE Symposium on Industrial Electronics & Applications","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2009-12-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"83254213","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2009-12-18DOI: 10.1109/ISIEA.2009.5356470
H. Nooralizadeh, S. Moghaddam, H. Bakhshi
In this article, we deal with the Training-Based Channel Estimation (TBCE) scheme in the spatially correlated Rician flat fading Multiple-Input Multiple-Output (MIMO) channels. The performance of the Least Squares (LS) and Linear Minimum Mean Square Error (LMMSE) estimators is investigated. Moreover, optimal training signals in the Minimum Mean Square Error (MMSE) sense are achieved. It is shown that the traditional LS estimator cannot exploit the knowledge of the first and second-order statistics about the Rician fading MIMO channel. However, the LMMSE estimator uses the knowledge of spatial correlation. Furthermore, when the Rice factor increases, the Mean Square Error (MSE) of this estimator significantly decreases. Theoretical analysis and simulation results show that the performance of the LMMSE estimator in the Rician model compared with Rayleigh one is much better.
{"title":"Optimal training sequences in MIMO channel estimation with spatially correlated Rician flat fading","authors":"H. Nooralizadeh, S. Moghaddam, H. Bakhshi","doi":"10.1109/ISIEA.2009.5356470","DOIUrl":"https://doi.org/10.1109/ISIEA.2009.5356470","url":null,"abstract":"In this article, we deal with the Training-Based Channel Estimation (TBCE) scheme in the spatially correlated Rician flat fading Multiple-Input Multiple-Output (MIMO) channels. The performance of the Least Squares (LS) and Linear Minimum Mean Square Error (LMMSE) estimators is investigated. Moreover, optimal training signals in the Minimum Mean Square Error (MMSE) sense are achieved. It is shown that the traditional LS estimator cannot exploit the knowledge of the first and second-order statistics about the Rician fading MIMO channel. However, the LMMSE estimator uses the knowledge of spatial correlation. Furthermore, when the Rice factor increases, the Mean Square Error (MSE) of this estimator significantly decreases. Theoretical analysis and simulation results show that the performance of the LMMSE estimator in the Rician model compared with Rayleigh one is much better.","PeriodicalId":6447,"journal":{"name":"2009 IEEE Symposium on Industrial Electronics & Applications","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2009-12-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"89537170","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2009-12-18DOI: 10.1109/ISIEA.2009.5356366
Abdul Halim Ismail, H. Ramli, Muhammad Hazim Ahmad, M. Marhaban
A vision based application is proposed for a line following mobile robot. A low-cost webcam is used as the sensor and the image buffers are processed via a customized image segregation method to output necessary information for the mobile robot's controller under uncontrollable lighting condition. The task is to allow the mobile robot to navigate through a predefined path marked by a white line on a dark green floor surface. Experimental results shows that the mobile robot successfully able to navigate throughout the provided path. This technique is robust, reliable and easily modified for used in any other applications, such in industrial applications where costly sensors and transducers are normally used.
{"title":"Vision-based system for line following mobile robot","authors":"Abdul Halim Ismail, H. Ramli, Muhammad Hazim Ahmad, M. Marhaban","doi":"10.1109/ISIEA.2009.5356366","DOIUrl":"https://doi.org/10.1109/ISIEA.2009.5356366","url":null,"abstract":"A vision based application is proposed for a line following mobile robot. A low-cost webcam is used as the sensor and the image buffers are processed via a customized image segregation method to output necessary information for the mobile robot's controller under uncontrollable lighting condition. The task is to allow the mobile robot to navigate through a predefined path marked by a white line on a dark green floor surface. Experimental results shows that the mobile robot successfully able to navigate throughout the provided path. This technique is robust, reliable and easily modified for used in any other applications, such in industrial applications where costly sensors and transducers are normally used.","PeriodicalId":6447,"journal":{"name":"2009 IEEE Symposium on Industrial Electronics & Applications","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2009-12-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"89556525","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2009-12-18DOI: 10.1109/ISIEA.2009.5356346
H. Ng
Polysilicon-Oxide-Diffusion (POD) capacitor is built on CMOS-based technology by special POD implant below gate oxide. Since the device construction is similar to gate oxide test structure, the standard breakdown voltage measurement is applied to POD as a dielectric integrity qualification. This paper presents an investigation of low oxide breakdown voltage on POD capacitor. The dielectric was 7nm thermal oxide, which was grown simultaneously for MOS transistor as gate oxide. The V-Ramp measurement showed bimodal distribution of Vbd with one circular patch having ≪7V instead of the target Vbd (10V). The size of the patch depends on the POD capacitor area. This behavior was not observed on gate oxide of MOS transistor and 22.5nm POD capacitor. Process partition check, including wafer orientation and wafer slot arrangement was conducted. The patch signature has been identified closely related to the cleaning step before POD gate oxidation. Further process improvement on resist removal has successfully eliminated the patch signature giving much more process margin for subsequent cleaning steps.
{"title":"Improvement of bimodal breakdown voltage behavior on thin Oxide POD capacitor","authors":"H. Ng","doi":"10.1109/ISIEA.2009.5356346","DOIUrl":"https://doi.org/10.1109/ISIEA.2009.5356346","url":null,"abstract":"Polysilicon-Oxide-Diffusion (POD) capacitor is built on CMOS-based technology by special POD implant below gate oxide. Since the device construction is similar to gate oxide test structure, the standard breakdown voltage measurement is applied to POD as a dielectric integrity qualification. This paper presents an investigation of low oxide breakdown voltage on POD capacitor. The dielectric was 7nm thermal oxide, which was grown simultaneously for MOS transistor as gate oxide. The V-Ramp measurement showed bimodal distribution of Vbd with one circular patch having ≪7V instead of the target Vbd (10V). The size of the patch depends on the POD capacitor area. This behavior was not observed on gate oxide of MOS transistor and 22.5nm POD capacitor. Process partition check, including wafer orientation and wafer slot arrangement was conducted. The patch signature has been identified closely related to the cleaning step before POD gate oxidation. Further process improvement on resist removal has successfully eliminated the patch signature giving much more process margin for subsequent cleaning steps.","PeriodicalId":6447,"journal":{"name":"2009 IEEE Symposium on Industrial Electronics & Applications","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2009-12-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"89983799","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
京公网安备 11010802042870号
京ICP备2023020795号-1
扫码关注我们
求助内容：
应助结果提醒方式：