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Hochschild cohomology ring modulo nilpotence of a one point extension of a quiver algebra defined by two cycles and a quantum-like relation

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Frontiers of Mathematics in China 2016年第4期11卷 1003-1015页

作者： daiki OBARA Department of Mathematics Tokyo University of Science Shinjuku-ku Tokyo Japan

We consider a one point extension algebra B of a quiver algebra Aq over a field k defined by two cycles and a quantum-like relation depending on a nonzero element q in k. We determine the Hochschild cohomology ring of B modulo nilpotence and show that if q is a root of unity, then B is a counterexample to Snashall-Solberg＇s conjecture.

关键词： Hochschild cohomology, quantum-like relation one point extension

Diffusion and collective motion of rotlets in 2D space

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Chinese Physics B 2020年第6期29卷 37-43页

作者： daiki Matsunaga Takumi Chodo Takuma Kawai Graduate School of Engineering Science Osaka University5608531 OsakaJapan

We investigate the collective motion of rotlets that are placed in a single plane. Due to the hydrodynamic interactions,the particles move through the two-dimensional(2D) plane and we analyze these diffusive motions. By analyzing the scaling of the values, we predict that the diffusion coefficient scales with φ0.5, the average velocity with φ, and relaxation time of the velocity autocorrelation function with φ-1.5, where φ is the area fraction of the particles. In this paper, we find that the predicted scaling could be seen only when the initial particle position is homogeneous. The particle collective motions are different by starting the simulation from random initial positions, and the diffusion coefficient is the largest at a minimum volume fraction of our parameter range, φ = 0.05. The deviations based on two initial positions can be explained by the frequency of the collision events. The particles collide during their movements and the inter-particle distances gradually increase. When the area fraction is large, the particles will result in relatively homogeneous configurations regardless of the initial positions because of many collision events. When the area fraction is small(φ < 0.25), on the other hand, two initial positions would fall into different local solutions because the rare collision events would not modify the inter-particle distances drastically. By starting from the homogeneous initial positions, the particles show the maximum diffusion coefficient at φ≈ 0.20. The diffusion coefficient starts to decrease from this area fraction because the particles start to collide and hinder each other from a critical fraction ~23%. We believe our current work contributes to a basic understanding of the collective motion of rotating units.

关键词： rotlet diffusion Stokes flow

Global Search of a Three-dimensional Low Solidity Circular Cascade Diffuser for Centrifugal Blowers by Meta-model Assisted Optimization

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Journal of Thermal Science 2018年第2期27卷 111-116页

作者： Daisaku Sakaguchi daiki Sakue Min Thaw Tun Nagasaki University 1-14 Bunkyo-machi Nagasaki 852-8521 Japan Yangon Technological University Insein Road East Gyogone Insein Township Yangon

A three-dimensional blade of a low solidity circular cascade diffuser in centrifugal blowers is designed by means of a multi-point optimization technique. The optimization aims at improving static pressure coefficient at a design point and at a small flow rate condition. Moreover, a clear definition of secondary flow expressed by positive radial velocity at hub side is taken into consideration in constraints. The number of design parameters for three-dimensional blade reaches to 10 in this study, such as a radial gap, a radial chord length and mean camber angle distribution of the LSD blade with five control points, control point between hub and shroud with two design freedom. Optimization results show clear Pareto front and selected optimum design shows good improvement of pressure rise in diffuser at small flow rate conditions. It is found that three-dimensional blade has advantage to stabilize the secondary flow effect with improving pressure recovery of the low solidity circular cascade diffuser.

关键词： Multi-point optimization Low solidity cascade diffuser Flow range enhancement

New Technical Trends on Adjustable Speed AC Motor Drives

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Chinese Journal of Electrical Engineering 2017年第1期3卷 1-9页

作者： Kouki Matsuse daiki Matsuhashi Meiji University TokyoJapan Meidensha Corporation TokyoJapan

Adjustable speed AC Motor drives have been used extensively in modern industry and transportation which calls for electrical and mechanical energy conversion with wide output power range *** of its modularity and scalability,the drive system can be extended to many different application *** recently,adjustable speed AC motor drive applications are spreading not only in industry applications,but also sky and the *** this paper,after summarizing the history of adjustable speed AC motor drives and applications,the main issues of AC drive technologies are reviewed and investigated in the *** issues of adjustable speed AC motor drives including its standardization are surveyed and analyzed for more ***,the paper provides the latest technical trends on adjustable speed AC motor drives technologies,and discusses the development of high speed high power PM motor.

关键词： Electric machine drive technology adjustable speed motor drive AC machine drive system Industry applications transportation application high speed PM motor

Technical aspects in pancreaticoduodenectomy and therapeutic strategies for pancreatic cancer:History,current status,and future perspectives

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Hepatobiliary & Pancreatic Diseases International 2022年第6期21卷 600-602页

作者： Tomohide Hori daiki Yasukawa Department of Surgery Shiga General HospitalMoriyama 524-8524Japan Department of Surgery Shiga University of Medical ScienceOtsu 520-2192Japan

The incidence of pancreatic cancer(PC)has increased,and in-vasive ductal adenocarcinoma is the most common among PC pa-tients[1].Even in patients who receive radical treatments,namely chemotherapy and surgery,the five-year survival is only 2%-9%[1].Currently,many physicians recognize that further developments in multidisciplinary therapy are crucial to overcome PC[1].

关键词： cancer chemotherapy surgery

Eosinophilic gastroenteritis with cytomegalovirus infection in an immunocompetent child

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World Journal of Gastroenterology 2007年第34期13卷 4653-4654页

作者： Junji Takeyama daiki Abukawa Katsushi Miura Department of Pathology Miyagi Children's Hospital Sendai 989-3126 Japan Department of General Pediatrics Miyagi Children's Hospital Sendai 989-3126 Japan

A 3-year-old boy developed transient protein-losing gastroenteropathy associated with cytomegalovirus (CMV) infection. Both IgG and IgM antibodies to CMV were positive in a serologic blood test. Upper gastrointestinal endoscopy showed multiple erosions throughout the body of the stomach, without enlarged gastric folds. Histological examination of the biopsy specimens indicated eosinophilic gastroenteritis and CMV infection. The patient had complete resolution without specific therapy for CMV in four weeks. An allergic reaction as well as CMV infection played important roles in the pathogenesis of this case.

关键词： Eosinophilic gastroenteritis Cytomegalovirus Protein-losing gastroenteropathy Allergy Menetrier'sdisease

Facile synthesis and characterization of a novel thiophene-fused polycyclic aromatics based on pyrene

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Chinese Chemical Letters 2011年第7期22卷 819-822页

作者： daiki Hoshino Tsuyoshi Morita Yasushiro Nishioka College of Science and Technology Nihon UniversityNarashinodaiFunabashiChiba 2748501Japan

A novel large thiophene-fused polycyclic aromatics 1 based on pyrene 5 has been synthesized, and its structure was confirmed by ^1H NMR, ^13C NMR, MS, UV-vis and elemental analysis. The key steps of the synthesis involved the Stille cross-coupling reaction and followed by selective β-β oxidative cyclization of pendant thienyl rings by FeCl3 under mild conditions.

关键词： Pyrene Thiophene Stille coupling reaction Oxidative cyclization

Flow Range Enhancement by Secondary Flow Effect in Low Solidity Circular Cascade Diffusers

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Journal of Thermal Science 2014年第4期23卷 391-400页

作者： Daisaku Sakaguchi Min Thaw Tun Kanata Mizokoshi daiki Kishikawa Nagasaki Japan

High-pressure ratio and wide operating range are highly required for compressors and blowers. The technical issue of the design is achievement of suppression of flow separation at small flow rate without deteriorating the efficiency at design flow rate. A numerical simulation is very effective in design procedure, however, cost of the numerical simulation is generally high during the practical design process, and it is difficult to confn＇m the optimal design which is combined with many parameters. A multi-objective optimization technique is the idea that has been proposed for solving the problem in practical design process. In this study, a Low Solidity circular cascade Diffuser （LSD） in a centrifugal blower is successfully designed by means of multi-objective optimization technique. An optimization code with a meta-model assisted evolutionary algorithm is used with a commercial CFD code ANSYS-CFX. The optimization is aiming at improving the static pressure coefficient at design point and at low flow rate condition while constraining the slope of the lift coefficient curve. Moreover, a small tip clearance of the LSD blade was applied in order to activate and to stabilize the secondary flow effect at small flow rate condition. The optimized LSD blade has an extended operating range of 114 % towards smaller flow rate as compared to the baseline design without deteriorating the diffuser pressure recovery at design point. The diffuser pressure rise and operating flow range of the optimized LSD blade are experimentally verified by overall performance test. The detailed flow in the diffuser is also confirmed by means of a Particle Image Velocimeter. Secondary flow is clearly captured by PIV and it spreads to the whole area of LSD blade pitch. It is found that the optimized LSD blade shows good improvement of the blade loading in the whole operating range, while at small flow rate the flow separation on the LSD blade has been successfully suppressed by the secondary flow e

关键词： Low solidity circular cascade diffuser Multi-objective optimization Secondary flow Flow range enhancement

Crucial anatomy and technical cues for laparoscopic transabdominal preperitoneal repair: Advanced manipulation for groin hernias in adults

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World Journal of Gastrointestinal Surgery 2020年第7期12卷 307-325页

作者： daiki Yasukawa Yuki Aisu Tomohide Hori Department of Surgery Shiga University of Medical ScienceOtsu 520-2192Japan Department of Surgery Kyoto University Graduate School of MedicineKyoto 606-8507Japan

Groin hernias include indirect inguinal, direct inguinal, and femoral hernias. Obturator and supravesical hernias appear very close to the groin. High-quality repairs are required for groin hernias. The concept of "tension-free repair" is generally accepted, and surgical repairs with mesh are categorized as "hernioplasties". Surgeons should have good knowledge of the relevant anatomy. Physicians generally focus on the preperitoneal space, myopectineal orifice, topographic nerves, and regional vessels. Currently, laparoscopic surgery has therapeutic potential in the surgical setting for hernioplasty, with laparoscopic transabdominal preperitoneal(TAPP) repair appearing to be a powerful tool for use in adult hernia patients. TAPP offers the advantages of accurate diagnoses, repair of bilateral and recurrent hernias, less postoperative pain, early recovery allowing work and activities, tension-free repair of the preperitoneal(posterior) space, ability to cover obturator hernias, and avoidance of potential injury to the spermatic cord. The disadvantages of TAPP are the need for general anesthesia, adhering to a learning curve, higher cost, unexpected complications related to abdominal organs, adhesion to the mesh, unexpected injuries to vessels, prolonged operative time, and as-yet-unknown long-term outcomes. Both technical skill and anatomical familiarity are important for safe, reliable surgery. With increasing awareness of the importance of anatomy during TAPP repair, we address the skills and pitfalls during laparoscopic TAPP repair in adult patients using illustrations and schemas. We also address debatable points on this subject.

关键词： Inguinal hernia Femoral hernia Obturator hernia Laparoscopic surgery Laparoscope Anatomy