• Title/Summary/Keyword: Rare

Search Result 12,035, Processing Time 0.032 seconds

An Optimal Design of BLDC Motor Using Rare Earth Magnet By Niching Genetic Algorithm (Niching 유전 알고리즘을 이용한 희토류 자석 BLDC 모터의 최적설계)

  • Chung, Byung-Ho;Chung, Tae-Kyung;Jin, Yang-Sun
    • Proceedings of the KIEE Conference
    • /
    • 2000.07b
    • /
    • pp.717-719
    • /
    • 2000
  • In this paper, we discussed an optimal design of BLDC motor using rare earth magnet. In motor design using rare earth magnet, because of the characteristics that rare earth magnets have high remanence, the effect of saturation of steel has to be considered. For this, we used nonlinear finite clement method. For optimal design, a Niching genetic algorithm is used. As a result, we found out a set of BLDC motor shapes increasing motor efficiency, and decreasing cogging torque.

  • PDF

A review of rare complications of maxillary sinus floor augmentation

  • On, Sung Woon;Cho, Seoung-Won;Yang, Byoung-Eun
    • Journal of the Korean Association of Oral and Maxillofacial Surgeons
    • /
    • v.45 no.6
    • /
    • pp.351-356
    • /
    • 2019
  • Maxillary sinus floor augmentation (MSFA) is an essential procedure for implant installation in the posterior maxillary area with vertical alveolar bone deficiency. For the past several decades, MSFA has been refined in terms of surgical methods along with technical progress, accumulation of clinical studies, and development of graft materials and surgical instruments. Although some complications in MSFA are inevitable in clinical situations, management of those complications in MSFA has been well established thanks to many clinicians and researchers. Nevertheless, some rare complications may arise and can result in fatal results. Therefore, clinicians should be well aware of such rare situations and complications associated with MSFA. In this review, the authors present several rare complications regarding MSFA, along with corresponding management strategies through a thorough review of the literature.

Improvement of Demagnetization by Rotor Structure of IPMSM with Dy-free Rare-Earth Magnet

  • Imamura, Keigo;Sanada, Masayuki;Morimoto, Shigeo;Inoue, Yukinori
    • Journal of international Conference on Electrical Machines and Systems
    • /
    • v.2 no.2
    • /
    • pp.141-147
    • /
    • 2013
  • Permanent magnet (PM) motors that employ rare-earth magnets containing dysprosium (Dy) are used in electric and hybrid electric vehicles. However, it is desirable to reduce the amount of Dy used since it is expensive. This study investigates the rotor structure of a PM synchronous motor with a Dy-free rare-earth magnet. Flux barrier shapes and PM thicknesses that enhance the irreversible demagnetization are investigated. In addition, a rotor structure that improves the irreversible demagnetization is proposed. We demonstrate that the proposed rotor structure without Dy improves the irreversible demagnetization.

Ultra-rare Disease and Genomics-Driven Precision Medicine

  • Lee, Sangmoon;Choi, Murim
    • Genomics & Informatics
    • /
    • v.14 no.2
    • /
    • pp.42-45
    • /
    • 2016
  • Since next-generation sequencing (NGS) technique was adopted into clinical practices, revolutionary advances in diagnosing rare genetic diseases have been achieved through translating genomic medicine into precision or personalized management. Indeed, several successful cases of molecular diagnosis and treatment with personalized or targeted therapies of rare genetic diseases have been reported. Still, there are several obstacles to be overcome for wider application of NGS-based precision medicine, including high sequencing cost, incomplete variant sensitivity and accuracy, practical complexities, and a shortage of available treatment options.

Co-doping Effects on the Blue Up-conversion Characteristics of Fluoride Glasses (희토류 원소의 복합첨가에 의한 fluride 유리에서의 청색 상향전이현상)

  • 류선윤
    • Journal of the Korean Ceramic Society
    • /
    • v.37 no.1
    • /
    • pp.33-43
    • /
    • 2000
  • Up-conversion of rare-earth element added glass is promising area for short wavelength laser source by utilizing high power semiconductor infra-red laser if the efficiency can be increased by proper method. In this study, relatively low phonon energy fluoride glasses were prepared by co-doping rare-earth elements to realize the high efficiency up-convertor. The physical, chemical, andoptical properties of co-doped fluoride glasses were measured. 10 combinations of 5 different rare-earth fluoride elements doped samples were prepared and their transition temperatures, chemical durability, density, hardness, refractive index, absorption, fluorescence, and fluorescence lifetime were measured. 480nm wavelengths blue up-conversion was found in the Yb3+/Tm3+ co-doped glass sample with 800nm laser source and the optimum composition for the most efficient blue up-conversion was found from the glass sample with 0.3 mol% TmF3 and 1 mol% YbF3.

  • PDF

A rare and unique experience of a blunt intrathoracic traumatic injury of the trachea and its management in South Africa: a case report

  • Rudo Mutsa Vanessa Pswarayi;Anna Katariina Kerola
    • Journal of Trauma and Injury
    • /
    • v.36 no.4
    • /
    • pp.416-420
    • /
    • 2023
  • Blunt intrathoracic tracheal injuries are rare, even among blunt chest trauma patients. An early diagnosis based on a high index of suspicion allows for timely surgical management of potentially fatal airway trauma, thereby improving overall outcomes. Diagnosing these injuries can be difficult due to their nonspecific clinical features and the occasional difficulty in radiologic diagnosis. If a patient exhibits respiratory compromise with difficult ventilation and poor lung expansion, despite the insertion and management of an intercostal drain following high-energy blunt trauma, there should be a heightened suspicion of potential airway trauma. The aim of primary repair is to restore airway integrity and to minimize the loss of pulmonary parenchyma function. This case report discusses the rare clinical presentation of a patient with blunt trauma to the intrathoracic airway, the surgical management thereof, and his overall outcome. Although blunt traumatic injuries of the trachea are extremely rare and often fatal, early surgical intervention can potentially reduce the risk of mortality.

Understanding and managing patients with adult rare diseases

  • Jangsup Moon
    • Journal of Genetic Medicine
    • /
    • v.21 no.1
    • /
    • pp.1-5
    • /
    • 2024
  • Despite advances in the diagnosis and management of rare diseases (RDs), there remains a tendency to overlook adult RD patients. In addition to the considerable number of adult-onset RDs, advances in the diagnosis and management of pediatric RDs have led to an increase in the survival of these patients into adulthood. Adult RDs exhibit distinct features from pediatric counterparts, necessitating careful consideration during medical assessments. Given the extended life expectancy of adult RD patients, precise diagnosis and management strategies can significantly enhance patient outcomes. This review aims to provide an in-depth exploration of the characteristics unique to adult RDs. Special emphasis will be placed on the importance of cascade screening and prenatal genetic testing in the context of adult RDs, highlighting the need for a comprehensive understanding of these aspects in clinical practice.

Ruptured mirror DACA aneurysm: A rare case report and review of literature

  • Deepak Kumar Singh;Prevesh Kumar Sharma;Arun Kumar Singh;Vipin Kumar Chand
    • Journal of Cerebrovascular and Endovascular Neurosurgery
    • /
    • v.25 no.3
    • /
    • pp.340-346
    • /
    • 2023
  • Bilateral distal anterior cerebral artery (DACA) aneurysms also called "kissing aneurysms" or "mirror aneurysm" are extremely rare, accounting for only 0.2% of all intracranial aneurysms. There have only been a few examples of mirror DACA aneurysms reported in the literature. Here, we report a rare case of mirror DACA aneurysm in a middle aged female with its successful clipping. Patient was admitted with severe headache and altered sensorium. Computed tomography (CT) head was suggestive of anterior inter-hemispheric hematoma. Digital subtraction angiography (DSA) was done which was suggestive of two distal anterior cerebral artery aneurysms located at same anatomical position. It was treated through microsurgical clipping. Mirror image DACA aneurysms are rare occurrence. All patients with ruptured DACA aneurysms should have angiography with 3D reconstruction studies. This aids in determining the aneurysm's morphology and planning treatment accordingly.