This paper describes a holistic approach to the theory of instantaneous power in three-phase four-wire systems, focusing on the original theory created in 1983 and a modified theory presented in 1994. The two theories are perfectly identical if no zero-sequence voltage is included in a three-phase three-wire system. However, they are different in the instantaneous active and reactive power in each phase if a zero-sequence voltage and current are included in a three-phase four-wire system. Theory and computer simulations in this paper lead to the following conclusions: an active filter without energy storage components can fully compensate for the neutral current even in a three-phase four-wire system including a zero-sequence voltage and current, when a proposed control strategy based on the original theory is applied. However, the active filter cannot compensate for the neutral current fully, when an already-proposed control strategy based on the modified theory is applied.
{"title":"The theory of instantaneous power in three-phase four-wire systems: a comprehensive approach","authors":"H. Akagi, S. Ogasawara, Hyosung Kim","doi":"10.1109/IAS.1999.799991","DOIUrl":"https://doi.org/10.1109/IAS.1999.799991","url":null,"abstract":"This paper describes a holistic approach to the theory of instantaneous power in three-phase four-wire systems, focusing on the original theory created in 1983 and a modified theory presented in 1994. The two theories are perfectly identical if no zero-sequence voltage is included in a three-phase three-wire system. However, they are different in the instantaneous active and reactive power in each phase if a zero-sequence voltage and current are included in a three-phase four-wire system. Theory and computer simulations in this paper lead to the following conclusions: an active filter without energy storage components can fully compensate for the neutral current even in a three-phase four-wire system including a zero-sequence voltage and current, when a proposed control strategy based on the original theory is applied. However, the active filter cannot compensate for the neutral current fully, when an already-proposed control strategy based on the modified theory is applied.","PeriodicalId":125787,"journal":{"name":"Conference Record of the 1999 IEEE Industry Applications Conference. Thirty-Forth IAS Annual Meeting (Cat. No.99CH36370)","volume":"19 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1999-10-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"121411191","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}
In this work, we report several approaches for the removal of SO/sub 2/ using nonthermal pulsed discharge plasma processing under absence of NH/sub 3/. The gas-phase reaction was found to be less attractive due to its high energy cost. The increase in temperature decreased the SO/sub 2/ removal rate, resulting in high energy cost. In case of the wet type plasma reactor, the discharge plasma greatly enhances the liquid phase oxidation of SO/sub 3//sup 2-/ to SO/sub 4//sup 2-/. The presence of TiO/sub 2/ catalyst increased the gas phase oxidation and the liquid phase oxidation as well.
{"title":"The influence of reaction conditions on SO/sub 2/ oxidation in a discharge plasma reactor","authors":"H. Kim, C. Wu, K. Takashima, A. Mizuno","doi":"10.1109/IAS.1999.805937","DOIUrl":"https://doi.org/10.1109/IAS.1999.805937","url":null,"abstract":"In this work, we report several approaches for the removal of SO/sub 2/ using nonthermal pulsed discharge plasma processing under absence of NH/sub 3/. The gas-phase reaction was found to be less attractive due to its high energy cost. The increase in temperature decreased the SO/sub 2/ removal rate, resulting in high energy cost. In case of the wet type plasma reactor, the discharge plasma greatly enhances the liquid phase oxidation of SO/sub 3//sup 2-/ to SO/sub 4//sup 2-/. The presence of TiO/sub 2/ catalyst increased the gas phase oxidation and the liquid phase oxidation as well.","PeriodicalId":125787,"journal":{"name":"Conference Record of the 1999 IEEE Industry Applications Conference. Thirty-Forth IAS Annual Meeting (Cat. No.99CH36370)","volume":"24 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1999-10-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"122014382","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}
With the increase in operating frequency as well as voltage and current levels, power devices have to sustain a number of stress causing phenomena. For proper selection for an application, the specifications for the device need to given with emphasis on the kind of stresses it will be subjected to in the application. In that respect, the data-sheet specifications are incomplete in that they fail to predict the safe operating area of the device in the actual operating conditions resulting in field failures. Long-term effects of stresses including the degradation of the device characteristics with "age in an application" needs to be characterized. From that view a dynamic SOA is proposed. This includes an experimentally determined factor, which varies with the age of the device as per the stresses encountered by the device. The variation is modeled for different applications. It is expected to aid greatly in specific device selection for an application.
{"title":"Dynamic SOA of power MOSFETs","authors":"N. Keskar, M. Trivedi, K. Shenai","doi":"10.1109/IAS.1999.801641","DOIUrl":"https://doi.org/10.1109/IAS.1999.801641","url":null,"abstract":"With the increase in operating frequency as well as voltage and current levels, power devices have to sustain a number of stress causing phenomena. For proper selection for an application, the specifications for the device need to given with emphasis on the kind of stresses it will be subjected to in the application. In that respect, the data-sheet specifications are incomplete in that they fail to predict the safe operating area of the device in the actual operating conditions resulting in field failures. Long-term effects of stresses including the degradation of the device characteristics with \"age in an application\" needs to be characterized. From that view a dynamic SOA is proposed. This includes an experimentally determined factor, which varies with the age of the device as per the stresses encountered by the device. The variation is modeled for different applications. It is expected to aid greatly in specific device selection for an application.","PeriodicalId":125787,"journal":{"name":"Conference Record of the 1999 IEEE Industry Applications Conference. Thirty-Forth IAS Annual Meeting (Cat. No.99CH36370)","volume":"6 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1999-10-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"125319862","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}
Additional heat produced in induction machines due to stray load losses could influence the plant rating, winding insulation design, operating limit and the machine protection design. Quantifying this additional heat and stray load losses accurately and, hence, investigating the extent of some of these influences are the concerns of this paper. Two experimentally verified models, electrical and thermal, are presented. A method for accurately measuring stray load losses is also proposed. The study, thereafter, gives insight into the relationship between stray load losses and the influences mentioned above and contribute results, which are useful to the design and operation of this machine and its protection.
{"title":"Thermal effects of stray load losses in induction machines","authors":"A. Jimoh","doi":"10.1109/IAS.1999.799997","DOIUrl":"https://doi.org/10.1109/IAS.1999.799997","url":null,"abstract":"Additional heat produced in induction machines due to stray load losses could influence the plant rating, winding insulation design, operating limit and the machine protection design. Quantifying this additional heat and stray load losses accurately and, hence, investigating the extent of some of these influences are the concerns of this paper. Two experimentally verified models, electrical and thermal, are presented. A method for accurately measuring stray load losses is also proposed. The study, thereafter, gives insight into the relationship between stray load losses and the influences mentioned above and contribute results, which are useful to the design and operation of this machine and its protection.","PeriodicalId":125787,"journal":{"name":"Conference Record of the 1999 IEEE Industry Applications Conference. Thirty-Forth IAS Annual Meeting (Cat. No.99CH36370)","volume":"3 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1999-10-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"125165329","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}
Five-phase synchronous reluctance machines (SynRM) have a higher torque density over conventional three-phase synchronous reluctance machines due to utilizing the third harmonics in the magnetic field interacting with appropriate armature current. However, for effective utilization of the third harmonics, it is critical that the rotor of the SynRM creates sufficient coupling between the fundamental and third harmonic components in the field. This paper presents a comparison study of the rotor structures for the non-sine five-phase SynRMs with a detailed examination of two different reluctance rotor structures. The comparison results show that with a simple structure, the salient-pole rotor creates strong mutual coupling between the fundamental and third harmonic MMFs and thus outperforms the complicated axially laminated rotor structures for non-sine five-phase SynRMs in terms of torque and ease of manufacturing.
{"title":"Comparison study of rotor structures for five-phase synchronous reluctance machines","authors":"Longya Xu, Baoguo Wang","doi":"10.1109/IAS.1999.801608","DOIUrl":"https://doi.org/10.1109/IAS.1999.801608","url":null,"abstract":"Five-phase synchronous reluctance machines (SynRM) have a higher torque density over conventional three-phase synchronous reluctance machines due to utilizing the third harmonics in the magnetic field interacting with appropriate armature current. However, for effective utilization of the third harmonics, it is critical that the rotor of the SynRM creates sufficient coupling between the fundamental and third harmonic components in the field. This paper presents a comparison study of the rotor structures for the non-sine five-phase SynRMs with a detailed examination of two different reluctance rotor structures. The comparison results show that with a simple structure, the salient-pole rotor creates strong mutual coupling between the fundamental and third harmonic MMFs and thus outperforms the complicated axially laminated rotor structures for non-sine five-phase SynRMs in terms of torque and ease of manufacturing.","PeriodicalId":125787,"journal":{"name":"Conference Record of the 1999 IEEE Industry Applications Conference. Thirty-Forth IAS Annual Meeting (Cat. No.99CH36370)","volume":"7 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1999-10-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"125260622","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}
This paper addresses the impact of power devices switching characteristics on design and performance of pulse width modulated current stiff converter (CSC) topologies with resonant snubbers. The MTO thyristors were selected for this study due to their high voltage and current ratings, simplified gate drive circuitry, unity gain turn-off, greatly reduced storage time allowing higher switching frequencies, and reverse voltage blocking capability. The analysis presented in this paper is supported by experimental data obtained from a CSC commutation cell capable of reproducing all the commutation processes in the current stiff converter topologies with active resonant snubbers. Issues involved in the implementation of the commutation cell itself and MTO characteristics relevant for their operation in CSC topologies with resonant snubbers are addressed in detail in this paper.
{"title":"Application of MTO-thyristors in current stiff converters with resonant snubbers","authors":"B. Filho, T. Lipo","doi":"10.1109/IAS.1999.805994","DOIUrl":"https://doi.org/10.1109/IAS.1999.805994","url":null,"abstract":"This paper addresses the impact of power devices switching characteristics on design and performance of pulse width modulated current stiff converter (CSC) topologies with resonant snubbers. The MTO thyristors were selected for this study due to their high voltage and current ratings, simplified gate drive circuitry, unity gain turn-off, greatly reduced storage time allowing higher switching frequencies, and reverse voltage blocking capability. The analysis presented in this paper is supported by experimental data obtained from a CSC commutation cell capable of reproducing all the commutation processes in the current stiff converter topologies with active resonant snubbers. Issues involved in the implementation of the commutation cell itself and MTO characteristics relevant for their operation in CSC topologies with resonant snubbers are addressed in detail in this paper.","PeriodicalId":125787,"journal":{"name":"Conference Record of the 1999 IEEE Industry Applications Conference. Thirty-Forth IAS Annual Meeting (Cat. No.99CH36370)","volume":"64 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1999-10-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"123466674","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}
The removal performance of dilute trichloroethylene (100-1,000 ppm TCE) contaminated in air by using nonthermal plasma processing combined with a catalyst is newly studied. Two catalysts are tested by comparing three different types of reactors. Catalysts tested were a few mm disc-like Cu-ZSM-5 (zeolite) and vanadium oxide pellets of a few mm (V/sub 2/O/sub 5//TiO/sub 2/). In order to separate TCE removals by the TCE absorption effect on the catalyst and the decomposition by the plasma processing with catalyst, TCE removal rate change with time was investigated. The relaxation time of absorption was from 6 to 80 minutes, which may be dependent on geometry and surface of the catalyst. Decomposition energy efficiency was estimated to realize the practical TCE remover.
{"title":"Decomposition of trichloroethylene by non-thermal plasma with catalyst","authors":"T. Oda, T. Takahashi, S. Kohzuma","doi":"10.1109/IAS.1999.805939","DOIUrl":"https://doi.org/10.1109/IAS.1999.805939","url":null,"abstract":"The removal performance of dilute trichloroethylene (100-1,000 ppm TCE) contaminated in air by using nonthermal plasma processing combined with a catalyst is newly studied. Two catalysts are tested by comparing three different types of reactors. Catalysts tested were a few mm disc-like Cu-ZSM-5 (zeolite) and vanadium oxide pellets of a few mm (V/sub 2/O/sub 5//TiO/sub 2/). In order to separate TCE removals by the TCE absorption effect on the catalyst and the decomposition by the plasma processing with catalyst, TCE removal rate change with time was investigated. The relaxation time of absorption was from 6 to 80 minutes, which may be dependent on geometry and surface of the catalyst. Decomposition energy efficiency was estimated to realize the practical TCE remover.","PeriodicalId":125787,"journal":{"name":"Conference Record of the 1999 IEEE Industry Applications Conference. Thirty-Forth IAS Annual Meeting (Cat. No.99CH36370)","volume":"35 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1999-10-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"122613286","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}
Mobile roof support (MRS) machines are used as roof support during pillar recovery in retreat operations in lieu of wooden posts, cribs, or hydraulic props. A Mine Safety and Health Administration permissible load rate monitoring system was developed for the MRS by researchers at the Spokane Research Laboratory of the National Institute for Occupational Safety and Health. The system uses a dedicated embedded processor to monitor changes in pressure inside the hydraulic cylinders of the MRS through multiplexed data acquisition channels and converts these pressure changes to load rates that sequentially activate three load-rate-indicator lights mounted on the machine. Each light represents a different loading rate to alert mine personnel to dangerous conditions during pillar extraction.
{"title":"Mobile roof support load rate monitoring system","authors":"W. L. Howie, J. Owens","doi":"10.1109/IAS.1999.799962","DOIUrl":"https://doi.org/10.1109/IAS.1999.799962","url":null,"abstract":"Mobile roof support (MRS) machines are used as roof support during pillar recovery in retreat operations in lieu of wooden posts, cribs, or hydraulic props. A Mine Safety and Health Administration permissible load rate monitoring system was developed for the MRS by researchers at the Spokane Research Laboratory of the National Institute for Occupational Safety and Health. The system uses a dedicated embedded processor to monitor changes in pressure inside the hydraulic cylinders of the MRS through multiplexed data acquisition channels and converts these pressure changes to load rates that sequentially activate three load-rate-indicator lights mounted on the machine. Each light represents a different loading rate to alert mine personnel to dangerous conditions during pillar extraction.","PeriodicalId":125787,"journal":{"name":"Conference Record of the 1999 IEEE Industry Applications Conference. Thirty-Forth IAS Annual Meeting (Cat. No.99CH36370)","volume":"27 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1999-10-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"128303544","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}
This paper presents an adaptive parallel processing control scheme, using an artificial neural network (ANN) which is trained while the controller is operating online. The proposed control structure incorporates five-multilayer feedforward ANNs, which are online trained using the Levenburg-Marquadt learning method. The five networks are used exclusively for system estimation. The estimation mechanism uses continual online training to learn the unknown stator model dynamics and estimate the rotor fluxes of an inverter-fed induction motor. Subsequently, the estimated stator currents are fed into an adaptive controller to track the desired stator current trajectories. The adaptive controller is constructed as a feedback signal (a predetermined control law), depending on estimated stator currents supplied by the neural estimators and the reference trajectories to be tracked by the output. The control of the direct and quadrature components of the stator current successfully tracked a wide variety of reference trajectories after relatively short, online training periods. This paper also suggests two three-layer ANNs control scheme to simultaneously identify and adaptively adjust the rotor speed to follow a predetermined reference track.
{"title":"Parallel computation of continually on-line trained neural networks for identification and control of induction motors","authors":"A. Rubaai, R. Kotaru, M. D. Kankam","doi":"10.1109/IAS.1999.799173","DOIUrl":"https://doi.org/10.1109/IAS.1999.799173","url":null,"abstract":"This paper presents an adaptive parallel processing control scheme, using an artificial neural network (ANN) which is trained while the controller is operating online. The proposed control structure incorporates five-multilayer feedforward ANNs, which are online trained using the Levenburg-Marquadt learning method. The five networks are used exclusively for system estimation. The estimation mechanism uses continual online training to learn the unknown stator model dynamics and estimate the rotor fluxes of an inverter-fed induction motor. Subsequently, the estimated stator currents are fed into an adaptive controller to track the desired stator current trajectories. The adaptive controller is constructed as a feedback signal (a predetermined control law), depending on estimated stator currents supplied by the neural estimators and the reference trajectories to be tracked by the output. The control of the direct and quadrature components of the stator current successfully tracked a wide variety of reference trajectories after relatively short, online training periods. This paper also suggests two three-layer ANNs control scheme to simultaneously identify and adaptively adjust the rotor speed to follow a predetermined reference track.","PeriodicalId":125787,"journal":{"name":"Conference Record of the 1999 IEEE Industry Applications Conference. Thirty-Forth IAS Annual Meeting (Cat. No.99CH36370)","volume":"14 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1999-10-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"127898232","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}
N. Keskar, R. Vijayalakshmi, M. Trivedi, K. Shenai, P. Neudeck
Silicon carbide is seen as a potent material for high power, high temperature and harsh environment applications because of its large band-gap, the consequently greater breakdown electric field, higher thermal conductivity and electron saturation velocity. However the commercial use of SIC devices is prohibited by the immature process technology and wafer quality deficiencies. While the most degrading micropipe defects have been significantly reduced in number, other defect types like screw dislocations continue to contaminate SiC devices in large quantities. This paper models the presence of embedded screw dislocation type defects for SiC PN junction diodes. The defects are presented as parallel diodes to the ideal ones with areas correspondingly reduced. Since the defects affect the I-V characteristics severely, these are studied in detail. Defect diodes are shown to turn on earlier to the ideal ones depending upon their built-in voltage, thus giving an anomalous bump in the initial part of forward I-V curves. The extracted diode structure is simulated in a 2-D finite element simulator and the static characteristics and forward I-V curves matched. Reverse recovery characteristics are also studied and found to vary very slightly with forward current.
{"title":"Characterization and modeling of high voltage SiC PN diode","authors":"N. Keskar, R. Vijayalakshmi, M. Trivedi, K. Shenai, P. Neudeck","doi":"10.1109/IAS.1999.799978","DOIUrl":"https://doi.org/10.1109/IAS.1999.799978","url":null,"abstract":"Silicon carbide is seen as a potent material for high power, high temperature and harsh environment applications because of its large band-gap, the consequently greater breakdown electric field, higher thermal conductivity and electron saturation velocity. However the commercial use of SIC devices is prohibited by the immature process technology and wafer quality deficiencies. While the most degrading micropipe defects have been significantly reduced in number, other defect types like screw dislocations continue to contaminate SiC devices in large quantities. This paper models the presence of embedded screw dislocation type defects for SiC PN junction diodes. The defects are presented as parallel diodes to the ideal ones with areas correspondingly reduced. Since the defects affect the I-V characteristics severely, these are studied in detail. Defect diodes are shown to turn on earlier to the ideal ones depending upon their built-in voltage, thus giving an anomalous bump in the initial part of forward I-V curves. The extracted diode structure is simulated in a 2-D finite element simulator and the static characteristics and forward I-V curves matched. Reverse recovery characteristics are also studied and found to vary very slightly with forward current.","PeriodicalId":125787,"journal":{"name":"Conference Record of the 1999 IEEE Industry Applications Conference. Thirty-Forth IAS Annual Meeting (Cat. No.99CH36370)","volume":"54 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1999-10-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"124827665","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}
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