24 results on '"Tatsuya Kitano"'
Search Results
2. Are sham‐operated mice a valid comparator in studies using a bladder outlet obstruction model? A pitfall reveals a meaningful insight
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Hiroki Chiba, Takeya Kitta, Tatsuya Kitano, Yukiko Kanno-Kakibuchi, Tsuyoshi Hattori, Mio Togo, Naohisa Kusakabe, Mai Michishita, Madoka Higuchi, Nobuo Shinohara, Mifuka Ouchi, and Yui Abe-Takahashi
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medicine.medical_specialty ,Urology ,media_common.quotation_subject ,Urinary system ,030232 urology & nephrology ,Urination ,Sham group ,Mice ,03 medical and health sciences ,Bladder outlet obstruction ,0302 clinical medicine ,Lower urinary tract symptoms ,Animals ,Medicine ,RNA, Messenger ,media_common ,Mucous Membrane ,business.industry ,Sham surgery ,Urination Frequency ,medicine.disease ,Urinary Bladder Neck Obstruction ,030220 oncology & carcinogenesis ,Serotonin ,business - Abstract
Objective To evaluate voiding behavior characteristics in intact and sham mice, and to examine whether intact mice show changes in "normal" micturition with aging. Methods A total of 72 8-week-old mice were divided into two groups - intact and sham - and the latter group was subjected to a sham of partial bladder outlet obstruction surgery. Urination frequency was evaluated (through metabolic cages) at 1, 2, 3, 6 and 12 months after the surgery (or at the equivalent time points for the intact mice). To address possible mechanisms for aging and surgical effects on urinary behavior, quantitative real-time polymerase chain reaction assays were carried out. Primary data were evaluated using scatter plots and descriptive statistics. Results In sham mice, urination frequency showed strong variation at the earlier post-surgical time points (especially at 1 month), with variation decreasing with time. Quantitative real-time polymerase chain reaction showed that the serotonin 2C receptor-encoding mRNA accumulated to >28-fold higher levels at 24 months compared with 3 months in intact mice. A major limitation of the quantitative real-time polymerase chain reaction experiments was that we did not separate whole bladder into muscle and mucosa. Conclusions Although a sham operation is typically used in partial bladder outlet obstruction experiments to provide control animals, the sham group might itself show increased variation in micturition frequency at early times after surgery, compared with intact animals.
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- 2020
3. Long‐term administration of alpha‐1 blocker can reverse the micturition pattern in a bladder outlet obstruction murine model
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Tatsuya Kitano, Madoka Higuchi, Mai Michishita, Nobuo Shinohara, Yui Abe-Takahashi, Mio Togo, Tsuyoshi Hattori, Yukiko Kanno-Kakibuchi, Hiroki Chiba, Takeya Kitta, and Mifuka Ouchi
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Male ,medicine.medical_specialty ,Urology ,media_common.quotation_subject ,medicine.medical_treatment ,030232 urology & nephrology ,Urination ,urologic and male genital diseases ,Mice ,03 medical and health sciences ,Bladder outlet obstruction ,0302 clinical medicine ,medicine ,Animals ,PROXIMAL URETHRA ,Circadian rhythm ,5-HT receptor ,media_common ,Tissue Inhibitor of Metalloproteinase-2 ,Naftopidil ,business.industry ,Alpha-1 blocker ,female genital diseases and pregnancy complications ,Urinary Bladder Neck Obstruction ,Disease Models, Animal ,Murine model ,030220 oncology & carcinogenesis ,business ,medicine.drug - Abstract
Objective To investigate the effect of chronic administration of an alpha-1 blocker on micturition patterns in long-term partial bladder outlet obstruction. Methods Mice were divided into three groups: a normal group, in which animals were fed a standard diet; a partial bladder outlet obstruction group, in which the proximal urethra was tied and animals were fed a standard diet; and a partial bladder outlet obstruction + naftopidil group, in which the proximal urethra was tied and animals were fed a standard diet containing naftopidil. Micturition behavior was evaluated in all groups for 6 months after partial bladder outlet obstruction surgery. The parameters evaluated included voided volume, time per void, urination frequency and total urine volume. Quantitative assessment of gene expression was also carried out. Results Total urine volume, as well as total and average voided volume during night, was significantly decreased in partial bladder outlet obstruction + naftopidil mice compared with partial bladder outlet obstruction animals. The levels of transcripts encoding 5-hydroxytryptamine 2A and tissue inhibitor of metalloproteinase 2 were significantly decreased in the partial bladder outlet obstruction + naftopidil group compared with the partial bladder outlet obstruction group. Conclusions Long-term administration of an alpha-1 blocker seems to reverse the disturbance of the micturition pattern caused by partial bladder outlet obstruction. Mechanistically, this effect might be mediated by changes in the expression of a serotonin receptor and/or in the activity of the fibrogenesis pathway.
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- 2020
4. Bladder outlet obstruction disrupts circadian bladder function in mice
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Yui Takahashi, Tatsuya Kitano, Hiroki Chiba, Takeya Kitta, Yukiko Kanno, Mio Togo, Mifuka Ouchi, Tsuyoshi Hattori, Mai Michishita, Madoka Higuchi, and Nobuo Shinohara
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medicine.medical_specialty ,media_common.quotation_subject ,Urology ,Circadian clock ,Urinary Bladder ,030232 urology & nephrology ,Neurophysiology ,Urination ,lcsh:Medicine ,Serotonergic ,Article ,03 medical and health sciences ,Bladder outlet obstruction ,Mice ,0302 clinical medicine ,Urethra ,Circadian Clocks ,Receptor, Serotonin, 5-HT2B ,medicine ,Nocturia ,Animals ,Humans ,Circadian rhythm ,RNA, Messenger ,Receptor ,lcsh:Science ,media_common ,Multidisciplinary ,business.industry ,lcsh:R ,Urinary Bladder Neck Obstruction ,Disease Models, Animal ,Gene Expression Regulation ,030220 oncology & carcinogenesis ,lcsh:Q ,Serotonin ,medicine.symptom ,business ,Muscle Contraction - Abstract
The circadian clock programs daily rhythms and coordinates multiple behavioural processes, including micturition. Partial bladder outlet obstruction (pBOO) in mice produces hyperactive voiding. However, long-term effects of pBOO on bladder function have not been clarified. In this study, we investigated micturition under conditions of impaired circadian bladder function by inducing long-term pBOO by tying the proximal urethra. Micturition behavior was evaluated at 1, 3, 6 and 12 months after surgery. We used automated voided stain on paper method for a precise micturition recording for mice. And quantitative assessment of gene expression was performed at 24 months after pBOO surgery using qRT-PCR procedure. The micturition frequencies in the pBOO group were significantly decreased at 3, 6, and 12 months compared to those at 1 month after operation in the same group (p
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- 2020
5. Peripheral tetrahydrobiopterin is involved in the pathogenesis of mechanical hypersensitivity in a rodent postsurgical pain model
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Hirokazu Arai, Satoru Yoshikawa, Yoshiaki Sakamoto, Okishi Mashita, Koh Kawasaki, Hiroshi Ichinose, Tatsuya Kitano, Satoshi Hara, and Rina Takahashi
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Rodentia ,Pharmacology ,Pathogenesis ,Mice ,03 medical and health sciences ,0302 clinical medicine ,030202 anesthesiology ,In vivo ,Animals ,Medicine ,GTP Cyclohydrolase ,Sepiapterin reductase ,Pain, Postoperative ,business.industry ,Heterozygote advantage ,Tetrahydrobiopterin ,Biopterin ,Rats ,Anesthesiology and Pain Medicine ,Nociception ,Neurology ,Neuropathic pain ,Immunohistochemistry ,Neurology (clinical) ,business ,030217 neurology & neurosurgery ,medicine.drug - Abstract
Because treatment for postsurgical pain (PSP) remains a major unmet medical need, the emergence of safe and innovative nonopioid drugs has been strongly coveted. Tetrahydrobiopterin (BH4) is an interesting molecule for gaining a better understanding the pathological mechanism of neuropathic pain. However, whether BH4 and its pathway are involved in the pathogenesis of PSP remains unclear. In this study, we found that early in a rat paw incision model, the gene expression of GTP cyclohydrolase 1 (GTPCH) and sepiapterin reductase (SPR), BH4-producing enzymes in the de novo pathway, were significantly increased in incised compared with naive paw skin. Although a significant increase in GTPCH protein levels was observed in incised paw skin until only 1 day after incision, a significant increase in BH4 levels was observed until 7 days after incision. In vivo, Spr-knockout mice showed an antinociceptive phenotype in the hind paw incision compared with the wild-type and Spr heterozygote groups. Furthermore, QM385, the SPR inhibitor, showed a significant dose-dependent, antinociceptive effect, which was supported by a reduction in BH4 levels in incised skin tissues, with no apparent adverse effects. Immunohistochemical analysis demonstrated that macrophages expressing GTPCH protein were increased around the injury site in the rat paw incision model. These results indicate that BH4 is involved in the pathogenesis of PSP, and that inhibition of the BH4 pathway could provide a new strategy for the treatment of acute PSP.
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- 2020
6. EVALUATION OF THE MECHANICAL PROPERTIES OF BRAID-CFRTP PRODUCED BY PULTRUSION
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Tsutao Katayama, Masataka Kawaguchi, Tatsuya Kitano, and Kazuto Tanaka
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Materials science ,Pultrusion ,Braid ,Composite material - Published
- 2020
7. Design and synthesis of benzoacridines as estrogenic and anti-estrogenic agents
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Kaoru Umehara, Rintaro Koga, Xiaohui Liu, Kenji Watanabe, Kohei Torikai, Yasuyuki Shimohigashi, Hiroshi Noguchi, Tatsuya Kitano, and Tohru Oishi
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medicine.drug_class ,Clinical Biochemistry ,Pharmaceutical Science ,Estrogen receptor ,Antineoplastic Agents ,Pharmacology ,010402 general chemistry ,Binding, Competitive ,01 natural sciences ,Biochemistry ,Structure-Activity Relationship ,Estrogen-related receptor alpha ,Drug Discovery ,Tumor Cells, Cultured ,medicine ,Humans ,Receptor ,Molecular Biology ,Estrogen receptor beta ,Cell Proliferation ,Dose-Response Relationship, Drug ,Molecular Structure ,010405 organic chemistry ,Chemistry ,Organic Chemistry ,Estrogen Antagonists ,Estrogens ,0104 chemical sciences ,Receptors, Estrogen ,Nuclear receptor ,Estrogen ,Drug Design ,MCF-7 Cells ,Acridines ,Molecular Medicine ,Estrogen-related receptor gamma ,Drug Screening Assays, Antitumor ,Estrogen receptor alpha ,hormones, hormone substitutes, and hormone antagonists ,HeLa Cells - Abstract
Estrogens play undisputedly important physiological roles, but lifetime exposure to estrogens has also been linked to the development of breast cancer. Moreover, imbalanced estrogen levels have been associated with various symptoms such as osteoporosis and menopausal disorders. For the improvement of such estrogen imbalances, estrogenic reagents with regulatory properties have shown promising potential. Herein, we report the construction of a 12-arylbenzoacridine library via a diversity-oriented strategy that furnished non-toxic estrogenic and anti-estrogenic agents. Derivatives with a hydroxy group at the molecular edge exhibit potent binding affinity to the estrogen receptor α (ERα) and ERβ (IC50 < μM), while binding to the estrogen-related receptor γ (ERRγ), i.e., an orphan nuclear receptor on which estrogens often trigger unfavorable events, was not observed. These findings offer valuable insights into 12-arylbenzoacridines as a novel platform for the development of selective estrogen-receptor modulators (SERMs).
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- 2017
8. Hybrid Map building using SLAM with loop closure
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Kousuke SHIZUKU, Rahok SAM ANN, Tatsuya KITANO, and Kazumichi INOUE
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- 2021
9. Practical Synthesis of DOPA Derivative for Biosynthetic Production of Potent Antitumor Natural Products, Saframycins and Ecteinascidin 743
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Takayoshi Saruwatari, Kohei Torikai, Kenji Watanabe, Takuya Sano, Atsuko Nakane, Hiroshi Noguchi, and Tatsuya Kitano
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polypeptide ,sarcoma ,Recrystallization (geology) ,Non-natural amino acid ,3,4-dihydroxyphenylalanine ,Organic Chemistry ,Saframycin ,Biosynthesis ,Biochemistry ,Combinatorial chemistry ,chemistry.chemical_compound ,chemistry ,DOPA ,Organic chemistry ,Ecteinascidin 743 ,bacteria ,tyrosine ,Derivative (chemistry) - Abstract
The features in the synthesis of title compound (X) are higher reproducibility, more facile handling without needs of setting dry and inert conditions, easy purification of (X) by recrystallization, and much better scalability.
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- 2011
10. An MPPT control scheme for a PV system utilizing limit cycle operation and its system design
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Mikihiko Matsui, Dehong Xu, and Tatsuya Kitano
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Operating point ,Engineering ,business.industry ,Photovoltaic system ,Energy Engineering and Power Technology ,Boundary (topology) ,Maximum power point tracking ,Power (physics) ,Control theory ,Limit cycle ,Systems design ,Electrical and Electronic Engineering ,Constant (mathematics) ,business - Abstract
This paper proposes a new simple maximum power point tracking (MPPT) control scheme for a PV system without using conventional “mountain climbing” optimum operating point searching technique. Although no information is needed on PV array, the generated output power is maximized by utilizing limit cycle phenomena occurring on the equilibrium/nonequilibrium boundary of system power flow. A parameter design procedure to determine operating period based on a theoretical model is presented. It has been found that the operating period of limit cycle is kept constant depending on the circuit and control parameters irrespective of the insolation conditions of PV array. Availability of the proposed new MPPT control scheme has been shown by simulation and experimental results. © 2003 Wiley Periodicals, Inc. Electr Eng Jpn, 143(2): 67–75, 2003; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/eej.10134
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- 2003
11. A MPPT Control Scheme for PV System Utilizing Limit Cycle Operation and Its System Design
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Mikihiko Matsui, Tatsuya Kitano, and Dehong Xu
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Operating point ,Engineering ,business.industry ,Photovoltaic system ,Boundary (topology) ,Industrial and Manufacturing Engineering ,Maximum power point tracking ,Power (physics) ,Control theory ,Limit cycle ,Electronic engineering ,Systems design ,Electrical and Electronic Engineering ,business ,Constant (mathematics) - Abstract
This paper proposes a new simple maximum power point tracking (MPPT) control scheme for a PV system without using conventional “mountain climbing” optimum operating point searching technique. Although no information is needed on PV array, the generated output power is maximized by utilizing limit cycle phenomena occurring on equilibrium/non-equilibrium boundary of system power flow. A parameter design procedure to determine operating period based on a theoretical model is presented. It has turned out that the operating period of limit cycle is kept constant depending on the circuit and control parameters irrespective of the insolation conditions of PV array, Availability of the proposed new MPPT control scheme has been shown by simulation and experimental results.
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- 2002
12. Abstract 3473: Functional analysis of the KIF22 in human prostate cancer cells
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Hiroji Uemura, Hitoshi Ishiguro, Akimitsu Takagi, Tadashi Nittami, Shungo Saito, Tatsuya Kitano, Jieun Seo, Rina Sakamaki, and Masatoshi Watanabe
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Oncology ,PCA3 ,Cancer Research ,medicine.medical_specialty ,Cell growth ,Cancer ,Cell migration ,Biology ,medicine.disease ,Prostate cancer ,DU145 ,Internal medicine ,LNCaP ,Cancer cell ,medicine ,Cancer research - Abstract
In the previous study, we identified genes that were differentially expressed between monolayers and spheroids in prostate cancer cell lines. The KIF22 gene was extracted as one of candidate genes related with spheroid formation and multicellular resistance. KIF22 is one of the kinesin superfamily proteins that are microtubule-dependent molecular motor proteins with DNA-binding capacity. KIF22 plays an important role in eukaryotic cell mitosis and macromolecule transportation. Alteration of KIF22 expression and function may lead to cancer development and progression. In this study, we explored the function of the KIF22 in prostate cancer cell lines, DU145 and LNCaP using the KIF22 siRNA. The KIF22 mRNA levels in LNCaP and DU-145 monolayers were detected, and time-dependently increased in both spheroids. The inhibition of KIF22 mRNA using siRNA affected cell proliferation in DU145 and LNCaP spheroids as well as monolayers. In addition, this suppression caused G2/M arrest and apoptosis in both cell lines. In clinical samples, its mRNA expression was significantly higher in tumor portions than in non-cancerous portions. However, the inhibition of KIF22 mRNA did not affect cell migration and invasion in DU145 and LNCaP cells. These findings suggest that KIF22 may play an important role in prostate cancer proliferation, especially spheroid formation, and have the potential to be targeted for prostate cancer treatments such as combination therapy with docetaxel. Citation Format: Rina Sakamaki, Shungo Saito, Tatsuya Kitano, Tadashi Nittami, Jieun Seo, Akimitsu Takagi, Hitoshi Ishiguro, Hiroji Uemura, Masatoshi Watanabe. Functional analysis of the KIF22 in human prostate cancer cells [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2017; 2017 Apr 1-5; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2017;77(13 Suppl):Abstract nr 3473. doi:10.1158/1538-7445.AM2017-3473
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- 2017
13. A Maximum Power Point Tracking Control Scheme for PV System Based on Power Equilibrium and Its System Design
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Dehong Xu, Mikihiko Matsui, and Tatsuya Kitano
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Engineering ,business.industry ,Photovoltaic system ,Industrial and Manufacturing Engineering ,Maximum power point tracking ,Power (physics) ,Experimental system ,Control theory ,Control system ,Grid-connected photovoltaic power system ,Electronic engineering ,Systems design ,Electrical and Electronic Engineering ,business ,Power control - Abstract
Since maximum power point tracking (MPPT) control is useful to realize an efficient PV system, many papers on MPPT scheme have been proposed. In most cases, they basically depend on so-called mountain climbing method which depends on the information of output power of PV array. Authors previously proposed a new MPPT control scheme for PV system connected in parallel with the ac system line. The system also depends on mountain climbing method. However, it needs no sensors or calculation for PV array power detection, and utilizes an interior control signal of dc link voltage control loop itself. For this reason, system response and stability greatly depend on the main circuit and control system parameters. This paper shows system design to ensure well-damped stable operation and fast response based on system analysis. Response of the experimental system has been proved fast enough for practical use.
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- 2001
14. M408 Research on the Combination Design of Internal and External Cooling of Gas Turbine Blade
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Tatsuya Kitano, Tadayuki Matsushita, and Yutaka Kawata
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Gas turbines ,Materials science ,Turbine blade ,Blade (geometry) ,law ,Mechanical engineering ,law.invention - Published
- 2016
15. ChemInform Abstract: Practical Synthesis of DOPA Derivative for Biosynthetic Production of Potent Antitumor Natural Products, Saframycins and Ecteinascidin 743
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Kohei Torikai, Atsuko Nakane, Tatsuya Kitano, Hiroshi Noguchi, Takayoshi Saruwatari, Takuya Sano, and Kenji Watanabe
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Inert ,Chemistry ,Recrystallization (metallurgy) ,General Medicine ,Combinatorial chemistry - Abstract
The features in the synthesis of title compound (X) are higher reproducibility, more facile handling without needs of setting dry and inert conditions, easy purification of (X) by recrystallization, and much better scalability.
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- 2012
16. A proposal of a Multi-DC Tap family suited for series-connected low voltage devices
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Mikihiko Matsui, Tatsuya Kitano, and Akihiko Ogawa
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Engineering ,Terminal (electronics) ,business.industry ,Modulation ,Photovoltaic system ,Electrical engineering ,Battery (vacuum tube) ,business ,Low voltage ,Active filter ,Diode ,Voltage - Abstract
A new circuit topology, Multi-DC Tap, in which several switching devices with anti-parallel diodes are connected in series to enable several arbitrary DC terminal voltages from a common DC link, is proposed. The control switching pattern for the Multi-DC Tap is investigated based on the direction of each terminal current and its buck/boost operation conditions. As a result, a simple strategy for switching pattern generation which doesn't depend on the current direction in each terminal is proposed. Several application examples including a battery-charger and a single phase PWM converter with DC active filter function have been shown.
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- 2010
17. A solar battery charging module by means of Limit-Cycle MPPT control
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Byunggyu Yu, Mikihiko Matsui, Tatsuya Kitano, and Kang-Hoon Koh
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Battery (electricity) ,Chopper ,Engineering ,Solar battery ,business.industry ,Electronic engineering ,Electrical engineering ,business ,Low voltage ,Solar power ,Maximum power point tracking ,Voltage ,Power (physics) - Abstract
The objective of this paper is to develop a power converter module that charges a battery with solar power, and the design technique at the product level is introduced to realize a compact size and light weight. The main circuit is a buck-boost chopper so that it can cover wide range of charging voltage. The MPPT control is realized by a very simple algorithm of Limit-Cycle MPPT (LCMPPT) proposed by authors previously. All control functions are implemented in digital algorithm and a HITACHI H8 microprocessor is used for the control. In addition to the battery, a load can be directly connected also, which is automatically disconnected in the case of detecting a low voltage condition of the battery. RS-232C port is also available for observing the internal variables such as input/output voltages and currents through a PC. An example of obtained test results showing the relations of output power versus input/output voltages and efficiency are given. The efficiency is about 70-72% in a wide range of output power.
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- 2007
18. New space vector modulation scheme based high-frequency link soft-switching converter for AC system line interface
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Tatsuya Kitano, Mikihiko Matsui, Dehong Xu, and S. Ohba
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Support vector machine ,Battery (electricity) ,Engineering ,business.industry ,Interfacing ,Interface (computing) ,Photovoltaic system ,Electronic engineering ,business ,Digital signal processing ,Space vector modulation ,Line (electrical engineering) - Abstract
This paper proposes a new switching pattern generating algorithm based on SVM (space vector modulation) technique for a high-frequency link soft-switching converter. Because of its totally soft-switched operation, isolated output stage and bidirectional power flow, the proposed converter system is suited for interfacing a new energy system, such as a PV (photovoltaic) system having a battery, with AC system line. The restriction of output vector transition in applying SVM technique is discussed first. Then, a suitable pattern which satisfies soft-switching operation is proposed. The validity of the proposed scheme has been proved with simulation study using PSIM and experimental results with DSP based prototype system.
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- 2003
19. A new maximum photovoltaic power tracking control scheme based on power equilibrium at DC link
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Dehong Xu, Tatsuya Kitano, Mikihiko Matsui, and Zhong-qing Yang
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Engineering ,Electricity generation ,Control theory ,business.industry ,Control system ,Lookup table ,Photovoltaic system ,Electronic engineering ,Optimal control ,business ,Electronic circuit simulation ,Maximum power point tracking ,Power (physics) - Abstract
This paper proposes a new simple MPPT (maximum power point tracking) control scheme for A PV (photovoltaic) array based on the principle of power equilibrium at the DC link. In contrast to the typical conventional MPPT scheme based on the so-called mountain climbing method, the proposed scheme needs no detection or calculation of the power and no decision making logic or look up tables, except for several numbers of operational amplifiers. Its operation principle is explained quantitatively. In order to confirm the availability of the scheme, a simulation study using general purpose circuit simulation software PSIM and an experiment have been carried out. Although the stability study and system design are left for future study, the validity of the proposed new MPPT method has been clarified through the simulation and experimental results.
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- 2003
20. A New Computational Method for Dynamic Behaviour of Two-Dimensional Free Surface
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Tatsuya Kitano, Hirochika Tanigawa, Jiro Funaki, and Katsuya Hirata
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Physics::Fluid Dynamics ,Surface (mathematics) ,Engineering ,Singularity ,business.industry ,Slosh dynamics ,Free surface ,Container (abstract data type) ,Boundary (topology) ,Structural engineering ,Mechanics ,business ,Stability (probability) - Abstract
A new method is proposed in order to compute dynamic behaviours of a liquid free surface. The method is based on a discrete singularity method, and enables us to simulate sloshing problems very easily and efficiently. The authors consider the free surface in a two-dimensional rectangular container that is vibrated vertically. It was found that there is the optimum clearance of singularity from a boundary, which makes surface error minimum. Furthermore, the authors conducted some experiments, and have observed three sloshing modes, and their stability regions. Then, we confirm that for the method is effective for 2D-sloshing problems.Copyright © 2003 by ASME
- Published
- 2003
21. Power sensor-less MPPT control scheme utilizing power balance at DC link-system design to ensure stability and response
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Dehong Xu, Tatsuya Kitano, and Mikihiko Matsui
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Power optimizer ,Engineering ,Electric power system ,Control theory ,business.industry ,Control system ,Photovoltaic system ,Electronic engineering ,Transient response ,business ,Maximum power point tracking ,Power control ,Power (physics) - Abstract
The authors previously proposed a new MPPT (maximum power point tracking) control scheme for PV (photovoltaic) power systems connected in parallel with the AC system line. It is characterised by utilizing power balance at the DC link under steady state conditions, hence eliminating the array output power detection and achieving power sensorless operation. However, the system response and stability greatly depend on its main circuit and control system parameters. This paper shows a system design to ensure stability and response based on system transfer functions. Response of the experimental system has been proved fast enough for practical use. Full-daytime testing data show the successful tracking results of the system.
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- 2002
22. Enhanced LCMPPT Control Strategy for Single Stage Power Conversion
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Mikihiko Matsui, Kang-Hoon Koh, and Tatsuya Kitano
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Battery (electricity) ,Engineering ,business.industry ,Photovoltaic system ,Grid ,Industrial and Manufacturing Engineering ,Maximum power point tracking ,Power (physics) ,Control theory ,Limit cycle ,Current sensor ,Electrical and Electronic Engineering ,business ,Power control - Abstract
The authors previously proposed a new maximum power point tracking strategy based on limit cycle phenomena (LCMPPT) for a grid connected PV system with dc linked two power conversion stages. This paper enhances its principle for the systems with single power conversion stage such like a battery charging system. Since, it needs only one current sensor, it is cost effective being easy to implement by using a low cost PIC microprocessors. Experimental results in proto-type system have been shown to prove its validity and usefulness.
- Published
- 2007
23. A Maximum Power Point Tracking Control Scheme for PV System Based on Limit Cycle Operation
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Tatsuya Kitano, Dehong Xu, and Mikihiko Matsui
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Operating point ,Engineering ,business.industry ,Photovoltaic system ,Industrial and Manufacturing Engineering ,Maximum power point tracking ,Power (physics) ,Control theory ,Limit cycle ,Grid-connected photovoltaic power system ,Electronic engineering ,Inverter ,Electrical and Electronic Engineering ,business ,Power control - Abstract
This paper proposes a new simple maximum power point tracking (MPPT) control scheme for a PV system without using conventional “mountain climbing” optimum operating point searching technique. Although no information of voltage and current is needed on PV array side, the generated output power on ac system side can be automatically maximized by utilizing limit cycle phenomena occurring on equilibrium/non-equilibrium boundary of system power flow. After explaining the operating principle of proposed scheme, it is applied to a common “boost chopper/3-phase inverter” interface power converter system. The experimental results show an availability of the new control scheme.
- Published
- 2001
24. On Various Modes of Vertical Sloshing in a Rectangular Container
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Katsuya Hirata, Yoshifumi Tanigawa, Jiro Funaki, Hirochika Tanigawa, and Tatsuya Kitano
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Slosh dynamics ,Mechanics ,Container (type theory) ,Geology - Published
- 2003
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