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Optimal Replacement Time of Electrical Components Based on Constant-Interval Replacement Model: Equipment Inspection Method and Weibull Analysis

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Energy and Power Engineering 2017年第4期9卷 475-485页

作者： Ohn Zin Lin hajime miyauchi Department of Computer Science and Electrical Engineering Kumamoto University Kumamoto Japan

The operation of distribution system with the components in deteriorating condition makes the system reliability worsen. It is important to find the solution for balancing failure cost and maintenance benefits such as down-time and reliability. In this paper, time to replace the components in optimum condition based on constant-interval replacement mode is investigated. The optimal replacement time is mainly depended on component’s reliability and the cost ration of preventive replacement and failure replacement. In this paper, equipment inspection method and Weibull Analysis is applied to obtain the accurate reliability estimation. Weibull Analysis is applied with constant-interval replacement model to investigate the optimum replacement time for each component considering the different cost ratios. According to the quantitative results, the determination of the optimal replacement time (OPT) can minimize the total downtime and failure cost. Consequently, the reliability of the system is maximized and estimation also becomes more accurate due to sufficient approach.

关键词： Optimal Replacement Reliability Cost Inspection Weibull Distribution

Seasonal Regression Models for Electricity Consumption Characteristics Analysis

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Engineering（科研） 2013年第1期5卷 108-114页

作者： Yusri Syam Akil hajime miyauchi Department of Frontier Technology for Energy and Devices Kumamoto University Kumamoto Japan Department of Frontier Technology for Energy and Devices Kumamoto University Kumamoto Japan Department of Electrical Engineering Hasanuddin University Makassar Indonesia

This paper presents seasonal regression models of demand to investigate electricity consumption characteristics. Electricity consumption in commercial areas in Japan is analyzed by using meteorological variables, namely temperature and relative humidity. A dummy variable for holidays is also considered. We have developed models for two levels of period to analyze demand characteristics, that is, half year models and seasonal models. Some options for each model are calculated and validated by statistical tests to obtain better models. As results, half year and seasonal models present explicit information about how the variables affect the demand differently for each period. These specific information help in analyzing characteristics of studied commercial demand.

关键词： Commercial Area Demand Characteristics Regression Model Seasons Relative Humidity Temperature

PID-Type Fuzzy Controller for Grid-Supporting Inverter of Battery in Embedded Small Variable Speed Wind Turbine

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Journal of Power and Energy Engineering 2014年第4期2卷 151-160页

作者： Ferdian Ronilaya hajime miyauchi Adi Kurniawan Department of Frontier Technology for Energy and Devices Kumamoto University Kumamoto-shi Japan Department of Electrical Power Engineering The State Polytechnic of Malang Malang Indonesia Institut Teknologi Sepuluh Nopember Surabaya Indonesia

Frequency and voltage of embedded variable speed wind turbine (VSWT) driving a permanent magnet synchronous generator (PMSG) is strongly affected by wind speed fluctuations. In practice, power imbalance between supply and demand is also common, especially when VSWT-PMSG is connected to a weak micro grid (MG). If load demand fluctuations become high, isolated MG may be unable to stabilize the frequency and voltage so that battery storage needs to be installed into the MG to adjust energy supply and demand. To allow flexible control of active and reactive power flow from/to battery storage, grid-supporting inverters are used. For a system that contains highly nonlinear components, the use of conventional linear proportional-integral-derivative (PID) controllers may cause system performance deterioration. Additionally, these controllers show slow, oscillating responses, and complex equations are required to obtain optimum responses in other controllers. To cope with these limitations, this paper proposes PID-type fuzzy controller (PIDfc) design to control grid-supporting inverter of battery. To ensure safe battery operating limits, we also propose a new controller scheme called intelligent battery protection (IBP). This IBP is integrated into PIDfc. Several simulation tests are performed to verify the scheme’s effectiveness. The results show that the proposed PIDfc controller exhibits improved performance and acceptable responses, and can be used instead of conventional controllers.

关键词： Battery PID-Type Fuzzy Controller Inverter Permanent Magnet Synchronous Generator (PMSG) Variable Speed Wind Turbine (VSWT)

A New Evolutionary Method for Solving Combined Economic and Emission Dispatch

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Energy and Power Engineering 2013年第4期5卷 774-779页

作者： A. N. Afandi hajime miyauchi Computer Science and Electrical Engineering GSST Kumamoto University Kumamoto Japan

This paper presents a new evolutionary method called in Harvest Season Artificial Bee Colony (HSABC) algorithm for solving constrained problems of Combined Economic and Emission Dispatch (CEED). The IEEE-30 bus system is adopted as a sample system for determining the best solutions of the CEED problems considering operational constraints. Running outs of designed programs for the HSABC show that applications of various compromised factors have different implications on the CEED’s results, that minimum cost computations are started at different values, and that increasing load demands have affected costs, pollutant emissions and generated powers.

关键词： Bees Cost Economic Emission Harvest Minimum

Application of Slantlet Transform Based Support Vector Machine for Power Quality Detection and Classification

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Journal of Power and Energy Engineering 2015年第4期3卷 215-223页

作者： Faridah Hanim M. Noh hajime miyauchi M. Faizal Yaakub Department of Frontier Technology for Energy & Devices Kumamoto University Kumamoto Japan Department of Electrical Power Engineering Universiti Tun Hussein Onn Malaysia Johor Malaysia Department of Electrical Engineering Technology Universiti Teknikal Malaysia Melaka Melaka Malaysia

Concern towards power quality (PQ) has increased immensely due to the growing usage of high technology devices which are very sensitive towards voltage and current variations and the de-regulation of the electricity market. The impact of these voltage and current variations can lead to devices malfunction and production stoppages which lead to huge financial loss for the production company. The deregulation of electricity markets has made the industry become more competitive and distributed. Thus, a higher demand on reliability and quality of services will be required by the end customers. To ensure the power supply is at the highest quality, an automatic system for detection and localization of PQ activities in power system network is required. This paper proposed to use Slantlet Transform (SLT) with Support Vector Machine (SVM) to detect and localize several PQ disturbance, i.e. voltage sag, voltage swell, oscillatory-transient, odd-harmonics, interruption, voltage sag plus odd-harmonics, voltage swell plus odd-harmonics, voltage sag plus transient and pure sinewave signal were studied. The analysis on PQ disturbances signals was performed in two steps, which are extraction of feature disturbance and classification of the dis- turbance based on its type. To take on the characteristics of PQ signals, feature vector was constructed from the statistical value of the SLT signal coefficient and wavelets entropy at different nodes. The feature vectors of the PQ disturbances are then applied to SVM for the classification process. The result shows that the proposed method can detect and localize different type of single and multiple power quality signals. Finally, sensitivity of the proposed algorithm under noisy condition is investigated in this paper.

关键词： Features Extraction Power Quality Disturbances Slantlet Transform Support Vector Machine

Evaluation of bacterial contamination and medium-term oncological outcomes of intracorporeal anastomosis for colon cancer:A propensity score matching analysis

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World Journal of Gastrointestinal Surgery 2024年第3期16卷 670-680页

作者： hajime Kayano Nana Mamuro Yutaro Kamei Takashi Ogimi Hiroshi Miyakita Toshio Nakagohri Kazuo Koyanagi Masaki Mori Seiichiro Yamamoto Department of Gastroenterological Surgery Tokai University School of MedicineIsehara 259-1193KanagawaJapan

BACKGROUND Although intracorporeal anastomosis(IA)for colon cancer requires longer operative time than extracorporeal anastomosis(EA),its short-term postoperative results,such as early recovery of bowel movement,have been reported to be equal or *** IA requires opening the intestinal tract in the abdominal cavity under pneumoperitoneum,there are concerns about intraperitoneal bacterial infection and recurrence of peritoneal dissemination due to the spread of bacteria and tumor ***,intraperitoneal bacterial contamination and medium-term oncological outcomes have not been *** cavity in *** Of 127 patients who underwent laparoscopic colon resection for colon cancer from April 2015 to December 2020,75 underwent EA(EA group),and 52 underwent IA(IA group).After propensity score matching,the primary endpoint was 3-year disease-free survival rates,and secondary endpoints were 3-year overall survival rates,type of recurrence,surgical site infection(SSI)incidence,number of days on antibiotics,and postoperative biological *** Three-year disease-free survival rates did not significantly differ between the IA and EA groups(87.2%and 82.7%,respectively,P=0.4473).The 3-year overall survival rates also did not significantly differ between the IA and EA groups(94.7%and 94.7%,respectively;P=0.9891).There was no difference in the type of recurrence between the two *** addition,there were no significant differences in SSI incidence or the number of days on antibiotics;however,postoperative biological responses,such as the white blood cell count(10200 vs 8650/mm^(3),P=0.0068),C-reactive protein(6.8 vs 4.5 mg/dL,P=0.0011),and body temperature(37.7 vs 37.5℃,P=0.0079),were significantly higher in the IA *** IA is an anastomotic technique that should be widely performed because its risk of intraperitoneal bacterial contamination and medium-term oncological outcomes are comparable to those of EA.

关键词： Colon cancer Intracorporeal anastomosis 3-year disease-free survival Recurrence Surgical site infection Postoperative biological response

Soft ground tunnel lithology classification using clustering-guided light gradient boosting machine

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Journal of Rock Mechanics and Geotechnical Engineering 2023年第11期15卷 2857-2867页

作者： Kursat Kilic hajime Ikeda Tsuyoshi Adachi Youhei Kawamura Department of Geosciences Geotechnology and Materials Engineering for ResourcesGraduate School of International Resource SciencesAkita UniversityAkita010-8502Japan Division of Sustainable Resources Engineering Faculty of EngineeringHokkaido UniversityKita 13Nishi 8Kita-kuSapporo060-8628Japan

During tunnel boring machine(TBM)excavation,lithology identification is an important issue to understand tunnelling performance and avoid time-consuming ***,site investigation generally lacks ground samples and the information is subjective,heterogeneous,and imbalanced due to mixed ground *** this study,an unsupervised(K-means)and synthetic minority oversampling technique(SMOTE)-guided light-gradient boosting machine(LightGBM)classifier is proposed to identify the soft ground tunnel classification and determine the imbalanced issue of tunnelling *** the tunnel excavation,an earth pressure balance(EPB)TBM recorded 18 different operational parameters along with the three main tunnel *** proposed model is applied using Python low-code PyCaret ***,four decision tree-based classifiers were obtained in a short time period with automatic hyperparameter tuning to determine the best model for clustering-guided SMOTE *** addition,the Shapley additive explanation(SHAP)was implemented to avoid the model black box *** proposed model was evaluated using different metrics such as accuracy,F1 score,precision,recall,and receiver operating characteristics(ROC)curve to obtain a reasonable outcome for the minority *** shows that the proposed model can provide significant tunnel lithology identification based on the operational parameters of *** proposed method can be applied to heterogeneous tunnel formations with several TBM operational parameters to describe the tunnel lithologies for efficient tunnelling.

关键词： Earth pressure balance(EPB) Tunnel boring machine(TBM) Soft ground tunnelling Tunnel lithology Operational parameters Synthetic minority oversampling technique (SMOTE) K-means clustering

Analyses and architectural typology of preserved traditional mosques in the old city of Herat in Afghanistan:the case of Quzzat Quarter

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Built Heritage 2022年第4期6卷 51-64页

作者： Ghulam Mohammad Asim Shimizu hajime Faculty of Engineering and Science University of the Ryukyus1 Aza-SenbaruNishihara-choNakagami-gunOkinawa 903-0213Japan

The study aims to analyse the architectural typology and determine the period of construction for the preserved traditional mosques of the Quzzat Quarter in the Old City of Herat(known as the Pearl of Khorasan).Twenty-nine mosques are located in the area,three of which are modern and 26 are *** out of the 26 traditional mosques still exist and have preserved their traditional *** analogy to analyse water cisterns and mosques,we determine when each mosque was developed and establish the period of development for each *** analyses are carried out on the edifces’architectural *** analyses and mosque typologies suggest that fve buildings were built before the Timurid dynasty;two were built during the Timurid dynasty(1370−1507 CE);and one was built after the Timurid *** mosques incorporating elements from diferent periods are counted as exceptions,and the remaining two are considered to have been built during transitional periods.

关键词： Architectural analyses Analogy Period of development Preserved traditional mosques Built heritage conservation Herat Old City Afghanistan

Physical features and analysis of traditional mosques:the case of Quzzat quarter of Herat Old City,Afghanistan

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Built Heritage 2023年第3期7卷 1-17页

作者： Ghulam Mohammad Asim hajime Shimizu Faculty of Engineering and Science The University of the Ryukyus1 Aza-SenbaruNishihara-ChoNakagami-GunOkinawa903-0213Japan

This study examines the physical features of traditional mosques in the Quzzat(Bardrani)quarter of Herat Old City,*** mosques are constructed with locally available materials and are planned based on cultural and climatic *** are categorised as modern or *** mosques are divided into three subcategories:preserved,damaged(defaced),and *** mosques are formerly traditional mosques reconstructed with modern or industrial materials(concrete and reinforcement).This study explores the distribution of mosques and analyses their plan *** are categorised into five plan types,and three relative case studies are described in detail to provide a better understanding and an in-depth analysis of mosque typology.

关键词： Physical features Spatial and architectural analyses Traditional mosques Built heritage conservation Herat Old City Afghanistan