H. Ramadan, フサーム アーメド ラマダン, Y. Imamura, 今村 泰隆, Sihun Yang, 梁 時熏, M. Shoyama, 庄山 正仁, ヤスタカ イマムラ, ヤン シフン, マサヒト ショウヤマ
{"title":"Stability considerations for dc power systems with multi-level virtual conductors","authors":"H. Ramadan, フサーム アーメド ラマダン, Y. Imamura, 今村 泰隆, Sihun Yang, 梁 時熏, M. Shoyama, 庄山 正仁, ヤスタカ イマムラ, ヤン シフン, マサヒト ショウヤマ","doi":"10.15017/1546810","DOIUrl":"https://doi.org/10.15017/1546810","url":null,"abstract":"","PeriodicalId":39314,"journal":{"name":"Research Reports on Information Science and Electrical Engineering of Kyushu University","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2014-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"66745356","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}
Integration of Ge on the Si platforms is essential for the development of next generation large-scale integrated circuits. The Ge-on-insulator (GOI) structure is suited for the realization of high-mobility transistors channels and as epitaxial templates for optoelectronic and spintronic materials. In this work, the fabrication of thin (~50 nm) (100) GOI by the rapid melting growth process has been investigated. Growth with unstable crystal orientation has been observed in wide (=1 µm) GOI strips. However, orientation stabilized growth was achieved in narrow strips (~0.5 µm). Further stabilization of growth orientation was observed in mesh patterned growth with GOI width of 1 µm. Epitaxial growth of Ge was performed on the above structures and the formation of uniform epitaxial layer was demonstrated.
{"title":"Orientation stabilized rapid melting growth of thin (100) ge-on-insulator structures and their implementation in Homoepitaxial growth","authors":"M. Anisuzzaman, S. Muta, A. M. Hashim, T. Sadoh","doi":"10.15017/26855","DOIUrl":"https://doi.org/10.15017/26855","url":null,"abstract":"Integration of Ge on the Si platforms is essential for the development of next generation large-scale integrated circuits. The Ge-on-insulator (GOI) structure is suited for the realization of high-mobility transistors channels and as epitaxial templates for optoelectronic and spintronic materials. In this work, the fabrication of thin (~50 nm) (100) GOI by the rapid melting growth process has been investigated. Growth with unstable crystal orientation has been observed in wide (=1 µm) GOI strips. However, orientation stabilized growth was achieved in narrow strips (~0.5 µm). Further stabilization of growth orientation was observed in mesh patterned growth with GOI width of 1 µm. Epitaxial growth of Ge was performed on the above structures and the formation of uniform epitaxial layer was demonstrated.","PeriodicalId":39314,"journal":{"name":"Research Reports on Information Science and Electrical Engineering of Kyushu University","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2013-07-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"66745680","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 the design consideration of a low-profile LLC resonant converter using two flat trans- formers. The trend toward high power density, high efficiency, and low profile in power supplies has exposed a number of limitations in the use of magnetic component structures. The LLC resonant converter can be operated at a high switching frequency with high efficiency because the switching loss is reduced by soft-switching. However, flat transformer loss causes problems at a high switching frequency. As a result, temperature of flat transformers becomes high. Therefore, it is necessary to reduce the transformer temperature by analyzing the loss. In this proposed con- verter, flat transformer is integrated into advanced power conversion application systems. Low-profile power module of profile of about 14mm is achieved. Temperature inside of transformer repressed to 66.5 ℃ and an overall efficiency of about 96.5% was obtained.
{"title":"Design consideration of low-profile LLC resonant converter for reducing temperature of the transformer","authors":"Sihun Yang, S. Abe, M. Shoyama","doi":"10.15017/26513","DOIUrl":"https://doi.org/10.15017/26513","url":null,"abstract":"This paper presents the design consideration of a low-profile LLC resonant converter using two flat trans- formers. The trend toward high power density, high efficiency, and low profile in power supplies has exposed a number of limitations in the use of magnetic component structures. The LLC resonant converter can be operated at a high switching frequency with high efficiency because the switching loss is reduced by soft-switching. However, flat transformer loss causes problems at a high switching frequency. As a result, temperature of flat transformers becomes high. Therefore, it is necessary to reduce the transformer temperature by analyzing the loss. In this proposed con- verter, flat transformer is integrated into advanced power conversion application systems. Low-profile power module of profile of about 14mm is achieved. Temperature inside of transformer repressed to 66.5 ℃ and an overall efficiency of about 96.5% was obtained.","PeriodicalId":39314,"journal":{"name":"Research Reports on Information Science and Electrical Engineering of Kyushu University","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2012-09-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"66745671","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}
Global localization is a fundamental requirement for a mobile robot. Map-based global local- ization is a popular technique and gives a precise position by comparing a provided geometric map and current sensory data. However, it is quite time-consuming if 3D range data is processed for 6D global lo- calization. On the other hand, appearance-based global localization using a captured image and recorded images is simple and suitable for real-time processing. However, this technique does not work in the dark or in an environment in which the lighting conditions change remarkably. To cope with these problems, we have proposed a two-step strategy which combines map-based global localization and appearance-based global localization. Firstly, several candidate positions are selected according to an appearance-based technique, and then the optimum position is determined by a map-based technique. Instead of camera images, we use reflectance images, which are captured by a laser range finder as a by-product of range sensing. In this paper, a new technique based on this global localization technique is proposed by combin- ing the two step algorithm and a sampling-based approach. To cope with the odometry data, a particle filter is adopted for tracking robot positions. The effectiveness of the proposed technique is demonstrated through experiments in real environments.
{"title":"Global Localization for a Mobile Robot Using Laser Reflectance and Particle Filter","authors":"Dong Zhang, R. Kurazume","doi":"10.15017/21947","DOIUrl":"https://doi.org/10.15017/21947","url":null,"abstract":"Global localization is a fundamental requirement for a mobile robot. Map-based global local- ization is a popular technique and gives a precise position by comparing a provided geometric map and current sensory data. However, it is quite time-consuming if 3D range data is processed for 6D global lo- calization. On the other hand, appearance-based global localization using a captured image and recorded images is simple and suitable for real-time processing. However, this technique does not work in the dark or in an environment in which the lighting conditions change remarkably. To cope with these problems, we have proposed a two-step strategy which combines map-based global localization and appearance-based global localization. Firstly, several candidate positions are selected according to an appearance-based technique, and then the optimum position is determined by a map-based technique. Instead of camera images, we use reflectance images, which are captured by a laser range finder as a by-product of range sensing. In this paper, a new technique based on this global localization technique is proposed by combin- ing the two step algorithm and a sampling-based approach. To cope with the odometry data, a particle filter is adopted for tracking robot positions. The effectiveness of the proposed technique is demonstrated through experiments in real environments.","PeriodicalId":39314,"journal":{"name":"Research Reports on Information Science and Electrical Engineering of Kyushu University","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2012-05-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"66745647","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 describes the design of a power conditioning unit (PCU) for photovoltaic power system to be interconnected with the utility grid (UG). The proposed PCU employs six-pulse three-phase inverter with modified-sinusoidal-pulse- width-modulation (MSPWM) switching technique, a parallel and series filters and an efficient control of dc to ac power conversion. The parallel and series filters are de- signed for both harmonics reduction and power factor correction. The efficient control of dc to ac power conversion makes the inverter output voltage immune to the variation in the dc voltage. The proposed PCU has been studied with both equation solving and extensive simulations. A 5 MW PCU has been designed and its performance has been investigated in detail.
{"title":"Low-Harmonics Three-Phase Power Conditioner for hotovoltaic Integration","authors":"H. El-Tamaly, G. M. Dousoky, M. Shoyama","doi":"10.15017/18986","DOIUrl":"https://doi.org/10.15017/18986","url":null,"abstract":"This paper describes the design of a power conditioning unit (PCU) for photovoltaic power system to be interconnected with the utility grid (UG). The proposed PCU employs six-pulse three-phase inverter with modified-sinusoidal-pulse- width-modulation (MSPWM) switching technique, a parallel and series filters and an efficient control of dc to ac power conversion. The parallel and series filters are de- signed for both harmonics reduction and power factor correction. The efficient control of dc to ac power conversion makes the inverter output voltage immune to the variation in the dc voltage. The proposed PCU has been studied with both equation solving and extensive simulations. A 5 MW PCU has been designed and its performance has been investigated in detail.","PeriodicalId":39314,"journal":{"name":"Research Reports on Information Science and Electrical Engineering of Kyushu University","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2010-09-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"66745630","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}
E. Firmansyah, S. Tomioka, 富岡 聡, S. Abe, 安部 征哉, M. Shoyama, 庄山 正仁, T. Ninomiya, 二宮 保, サトシ トミオカ, アベ セイヤ, マサヒト ショウヤマ, タモツ ニノミヤ
This paper explains about basic working principles, implementation problems, and experimental results of a new power factor correction (PFC) topology. In this proposed topology, a totem-pole boost PFC circuit that works under interleaved critical-conduction-mode (CRM) condition is presented. The circuit is developed towards high efficiency, high performance, lowcost, simple control scheme, and low conducted electro magnetic interference (EMI) PFC circuit. The application is targeted toward middle power applications that normally employs continuous or non-bridgeless interleaved boost converter.
{"title":"An Interleaved Totem-Pole Power Factor Correction Converter","authors":"E. Firmansyah, S. Tomioka, 富岡 聡, S. Abe, 安部 征哉, M. Shoyama, 庄山 正仁, T. Ninomiya, 二宮 保, サトシ トミオカ, アベ セイヤ, マサヒト ショウヤマ, タモツ ニノミヤ","doi":"10.15017/17889","DOIUrl":"https://doi.org/10.15017/17889","url":null,"abstract":"This paper explains about basic working principles, implementation problems, and experimental results of a new power factor correction (PFC) topology. In this proposed topology, a totem-pole boost PFC circuit that works under interleaved critical-conduction-mode (CRM) condition is presented. The circuit is developed towards high efficiency, high performance, lowcost, simple control scheme, and low conducted electro magnetic interference (EMI) PFC circuit. The application is targeted toward middle power applications that normally employs continuous or non-bridgeless interleaved boost converter.","PeriodicalId":39314,"journal":{"name":"Research Reports on Information Science and Electrical Engineering of Kyushu University","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2010-03-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"66745532","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}
A novel switching strategy for conducted-noise level reduction has been proposed in this paper. The proposed strategy uses three randomized parameters for generating the switching signals. These parameters are carrier frequency, duty-ratio, and the pulse position. This triple-hybrid switching strategy has been designed and implemented using field-programmable gate array (FPGA) technology. Moreover, the effect of using the proposed controller on commonmode and differential-mode noise, total conducted-noise, and radiated-noise characteristics of the dc-dc converter has been experimentally investigated. Furthermore, sweeping of the three randomization parameters has been carried-out for identifying the values which achieve the best conducted-noise level reduction. Numerous cases have been studied. All the studied cases have been designed, implemented and experimentally investigated. Then, the conducted-noise spectra have been compared. The experimental results show that using the proposed technique, with the identified randomization parameter values, significantly improves the conducted-noise spectrum and effectively reduces the noise peaks in both highand low-frequency ranges. Moreover, the radiated-noise spectrum has been improved.
{"title":"Triple-hybrid switching strategy for conducted-noise level reduction in DC-DC converters","authors":"G. M. Dousoky, M. Shoyama, T. Ninomiya","doi":"10.15017/17890","DOIUrl":"https://doi.org/10.15017/17890","url":null,"abstract":"A novel switching strategy for conducted-noise level reduction has been proposed in this paper. The proposed strategy uses three randomized parameters for generating the switching signals. These parameters are carrier frequency, duty-ratio, and the pulse position. This triple-hybrid switching strategy has been designed and implemented using field-programmable gate array (FPGA) technology. Moreover, the effect of using the proposed controller on commonmode and differential-mode noise, total conducted-noise, and radiated-noise characteristics of the dc-dc converter has been experimentally investigated. Furthermore, sweeping of the three randomization parameters has been carried-out for identifying the values which achieve the best conducted-noise level reduction. Numerous cases have been studied. All the studied cases have been designed, implemented and experimentally investigated. Then, the conducted-noise spectra have been compared. The experimental results show that using the proposed technique, with the identified randomization parameter values, significantly improves the conducted-noise spectrum and effectively reduces the noise peaks in both highand low-frequency ranges. Moreover, the radiated-noise spectrum has been improved.","PeriodicalId":39314,"journal":{"name":"Research Reports on Information Science and Electrical Engineering of Kyushu University","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2010-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"66745575","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}
Hiroshi Hayakawa, Kenya Sato, S. Tagashira, T. Nakanishi, A. Fukuda
Toward ubiquitous network society, there have been challenges to construct smart spaces in living space such as homes and offices by connecting embedded devices with each other; however, many existing smart spaces tend to depend on particular platform or be a self-contained environment. In this paper, we describe requirements on frameworks for smart spaces with embedded devices, and then propose a new framework based on the requirements. The proposed framework is designed to have high scalability and be suitable for cross-platform environments by employing RESTful web service for device interaction architecture. By encoding communication messages for requesting services in x-www-form-urlencoded scheme, the proposed framework can support many kinds of devices including resource-limited devices which can't afford an XML parser. Evaluation with existing frameworks shows the proposed framework is suitable as a framework for smart spaces because of its simple and lightweight architecture.
{"title":"RESTful device interaction architecture for embedded devices","authors":"Hiroshi Hayakawa, Kenya Sato, S. Tagashira, T. Nakanishi, A. Fukuda","doi":"10.15017/1517960","DOIUrl":"https://doi.org/10.15017/1517960","url":null,"abstract":"Toward ubiquitous network society, there have been challenges to construct smart spaces in living space such as homes and offices by connecting embedded devices with each other; however, many existing smart spaces tend to depend on particular platform or be a self-contained environment. In this paper, we describe requirements on frameworks for smart spaces with embedded devices, and then propose a new framework based on the requirements. The proposed framework is designed to have high scalability and be suitable for cross-platform environments by employing RESTful web service for device interaction architecture. By encoding communication messages for requesting services in x-www-form-urlencoded scheme, the proposed framework can support many kinds of devices including resource-limited devices which can't afford an XML parser. Evaluation with existing frameworks shows the proposed framework is suitable as a framework for smart spaces because of its simple and lightweight architecture.","PeriodicalId":39314,"journal":{"name":"Research Reports on Information Science and Electrical Engineering of Kyushu University","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2009-09-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"66745330","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}
Zhenqiang Li, 李 振強, S. Kanae, 金江 春植, Zi‐Jiang Yang, 楊 子江, K. Wada, 和田 清, シュンショク カナエ, ワダ キヨシ
This paper deals with the problem of estimating the parameters of Hammerstein systems based on recursive least squares method. Hammerstein systems can be considered as one kind of nonlinear systems, it is applied in many fields. Several identification methods of Hammerstein systems have been developed. We utilize the recursive algorithm to identify the system and the obtained simulation results show the effectiveness of this approach.
{"title":"Identification of Hammerstein Systems with a Recursive Algorithm","authors":"Zhenqiang Li, 李 振強, S. Kanae, 金江 春植, Zi‐Jiang Yang, 楊 子江, K. Wada, 和田 清, シュンショク カナエ, ワダ キヨシ","doi":"10.15017/1517946","DOIUrl":"https://doi.org/10.15017/1517946","url":null,"abstract":"This paper deals with the problem of estimating the parameters of Hammerstein systems based on recursive least squares method. Hammerstein systems can be considered as one kind of nonlinear systems, it is applied in many fields. Several identification methods of Hammerstein systems have been developed. We utilize the recursive algorithm to identify the system and the obtained simulation results show the effectiveness of this approach.","PeriodicalId":39314,"journal":{"name":"Research Reports on Information Science and Electrical Engineering of Kyushu University","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2009-03-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"66745786","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}
Temperature dependence of magnetic properties in [Co/Pd]N multilayer have been systematically studied for lithographically patterned samples with different Co thicknesses tCo and the bi-layer number N by extraordinary Hall effect measurements. The perpendicular coercive field Hc decreases with the increase of tCo, excepting a very thin thickness of 1 A. While a threshold temperature (Tth) of Hc vanishing linearly increases with the increase of tCo. The Hc and Tth monotonously increases with the increase of N, ranged from 5 to 50. The superior crystalline structure for samples with the larger N was confirmed from enhanced Co/Pd(111) peak height in the XRD pattern. A practical thermal activation coefficient α of 174 was evaluated from a sweep rate dependence of Hc. A marked improvements for the heat assisted MRAM application was attained by air annealing of [Co(1.7 A)Pd(8 A )]30 at 220 °C, that is, the Hc was increased from 1.3 kOe to 2.9 kOe, while Tth reduced from 210 °C to 190 °C.
{"title":"Structural control of magnetic properties in Co/Pd multilayer for heat assisted perpendicular MRAM application","authors":"B. Purnama, Y. Nozaki, K. Matsuyama","doi":"10.15017/1654545","DOIUrl":"https://doi.org/10.15017/1654545","url":null,"abstract":"Temperature dependence of magnetic properties in [Co/Pd]N multilayer have been systematically studied for lithographically patterned samples with different Co thicknesses tCo and the bi-layer number N by extraordinary Hall effect measurements. The perpendicular coercive field Hc decreases with the increase of tCo, excepting a very thin thickness of 1 A. While a threshold temperature (Tth) of Hc vanishing linearly increases with the increase of tCo. The Hc and Tth monotonously increases with the increase of N, ranged from 5 to 50. The superior crystalline structure for samples with the larger N was confirmed from enhanced Co/Pd(111) peak height in the XRD pattern. A practical thermal activation coefficient α of 174 was evaluated from a sweep rate dependence of Hc. A marked improvements for the heat assisted MRAM application was attained by air annealing of [Co(1.7 A)Pd(8 A )]30 at 220 °C, that is, the Hc was increased from 1.3 kOe to 2.9 kOe, while Tth reduced from 210 °C to 190 °C.","PeriodicalId":39314,"journal":{"name":"Research Reports on Information Science and Electrical Engineering of Kyushu University","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2008-09-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"66745457","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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