• 한국지능시스템학회:학술대회논문집
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• 한국퍼지및지능시스템학회 2003년도 ISIS 2003
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• pp.307-310
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• 2003

In the maritime container terminal, LMTT(Linear Motor-based Transfer Technology) is horizontal transfer system for the yard automation, which has been proposed to take the place of AGV(Automated Guided Vehicle). The system is based on PMLSM (Permanent Magnetic Linear Synchronous Motor) that is consists of stator modules on the rail and shuttle car (mover). Because of large variant of mover's weight by loading and unloading containers, the difference of each characteristic of stator modules, and a stator module's trouble etc., LMCPS (Linear Motor Conveyance Positioning System) is considered as that the system is changed its model suddenly and variously. In this paper, we will introduce the soft-computing method of a multi-step prediction control for LMCPS using DR-FNN (Dynamically-constructed Recurrent Fuzzy Neural Network). The proposed control system is used two networks for multi-step prediction. Consequently, the system has an ability to adapt for external disturbance, cogging force, force ripple, and sudden changes of itself.

• Journal of Oral Medicine and Pain
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• 제39권1호
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• pp.22-25
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• 2014

Synovial chondromatosis (SC) in temporomandibular joint is a rare benign disorder characterized by cartilaginous metaplasia of the mesenchymal remnants of the synovial tissue. The etiology of the disease is unclear but may be associated with trauma, overuse, local infection, and embryologic disturbance. SC does not spontaneously resolve and respond to nonsurgical treatment. SC should be differentially diagnosed with other temporomandibular joint disorders such as arthralgia or osteoarthritis because surgery should be done for managing it. However, primary diagnosis of SC is not easy because of nonspecific symptoms and signs. For the patients with unsuccessful conservative treatment response, especially accompanied by crepitus, preauricular swelling or posterior open bite, computed tomography/cone-beam computed tomography or magnetic resonance imaging should to be performed to exclude SC. We discussed the importance of the early diagnosis and surgical treatment of SC from this case.

• Journal of Mechanical Science and Technology
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• 제16권12호
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• pp.1583-1593
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• 2002

This paper discusses the model validation and vibration suppression of an AMB flexible rotor via additional LQG controller. The main difficulty in the vibration suppression of the flexible rotor using AMB is to realize a controller that can minimize resonance without injuring the stabilized rigid modes. In order to solve this problem, simple scheme for system modeling and controller design are developed. Firstly, the AMB flexible rotor is stabilized with a PID controller, which leads to a new stable rotor-bearing system. Then, authors propose the model validation procedure using measured open-loop frequency responses to obtain an accurate model of the AMB flexible rotor system. After that, LQG controller with modal weighting is designed to suppress resonances of the stable rotor-bearing system. Due to the poor controllability and observability of flexible modes compared to rigid ones, balancing of two Gramians is prerequisite for the fair LQG controller design. Simulation with step disturbance and experimental results of unbalance response up to 10,000 rpm verified the effectiveness of the proposed scheme.

• Parasites, Hosts and Diseases
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• 제51권6호
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• pp.739-742
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• 2013

A 52-year-old woman presented with lower back pain, progressive symmetrical paraparesis with sensory impairment, and sphincter disturbance. Magnetic resonance imaging (MRI) of the whole spine revealed multiple intradural extramedullary serpiginous-mass lesions in the subarachnoid space continuously from the prepontine to the anterior part of the medulla oblongata levels, C7, T2-T8, and T12 vertebral levels distally until the end of the theca sac and filling-in the right S1 neural foramen. Sparganosis was diagnosed by demonstration of the sparganum in histopathological sections of surgically resected tissues and also by the presence of serum IgG antibodies by ELISA. DNA was extracted from unstained tissue sections, and a partial fragment of mitochondrial cytochrome c oxidase subunit 1 (cox1) gene was amplified using a primer set specific for Spirometra spp. cox1. After sequencing of the PCR-amplicon and alignment of the nucleotide sequence data, the causative agent was identified as the larva of Spirometra erinaceieuropaei.

• Journal of Korean Neurosurgical Society
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• 제56권5호
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• pp.436-440
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• 2014

Sarcoidosis is a systemic disease of unknown etiology that may affect any organ in the body. The nervous system is involved in 5-16% of cases of sarcoidosis. Here, we report a case of intramedullary sarcoidosis presenting with delayed spinal cord swelling after laminoplasty for the treatment of compressive cervical myelopathy. A 56-year-old woman was admitted to our hospital complaining of upper extremity pain and gait disturbance. The patient had undergone laminoplasty for compressive cervical myelopathy 3 months previously. Follow-up magnetic resonance imaging revealed a large solitary intramedullary lesion with associated extensive cord swelling, signal changes, and heterogeneous enhancement of spinal cord from C2 to C7. Spinal cord biopsy revealed non-necrotizing granulomas with signs of chronic inflammation. The final diagnosis of sarcoidosis was based upon laboratory data, imaging findings, histological findings, and the exclusion of other diagnoses. Awareness of such presentations and a high degree of suspicion of sarcoidosis may help arrive at the correct diagnosis.

• Journal of Electrical Engineering and Technology
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• 제8권6호
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• pp.1451-1456
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• 2013

This paper presents the improved zero power levitation control algorithm for a quadruple hybrid EMS (Electromagnetic Suspension) system. Quadruple hybrid EMS system is a united form of four hybrid EMS systems one on each corner coupled with a metal plate. Technical issue in controlling a quadruple hybrid EMS system is the permanent magnet's equilibrium point deviation caused by design tolerance which eventually leads to a limited zero power levitation control that only satisfies the zero power levitation in one or two hybrid EMS system among the four hybrid EMS system. In order to satisfy a complete zero power levitation control of the quadruple hybrid EMS system, the proposed method presented in this paper adds a compensating algorithm which adjusts the gap reference of each individual axe. Later, this paper proves the stability and effectiveness of the proposed control algorithm via experiment and disturbance test.

• 한국정밀공학회지
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• 제22권1호
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• pp.53-60
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• 2005

The wire rope of container crane is a important component to container transfer system and is used in a myriad of various applications such as elevator, mine hoist, construction machinery, and so on. If it happen wire rope failures in operating, it may lead to the safety accident and economic loss, which is productivity decline, competitive decline of container terminal, etc. To solve this problem, we developed the active and portable wire rope fault detecting system. The developed system consists of three parts that are the fault detecting, signal processing, and remote monitoring part. All detected signal has external noise or disturbance according to circumstances. Therefore we applied to discrete wavelet transform to extract a signal from noisy data that was used filter. As experimental result, we can reduce the expense for container terminal because of extension of exchange period of wire rope for container crane and this system is possible to apply in several fields to use wire rope.

• Journal of Korean Neurosurgical Society
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• 제42권6호
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• pp.441-445
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• 2007

Objective : The purpose of this study was to investigate the surgical results and prognostic factors for patients with soft cervical disc herniation with myelopathy. Methods : During the last 7 years, 26 patients with cervical discogenic myelopathy were undertaken anterior discectomy and fusion. Clinical and radiographic features were reviewed to evaluate the surgical results and prognostic factors. The clinical outcome was judged using two grading systems (Herkowitz's scale and Nurick's grade). Results : Male were predominant (4:1), and C5-6 was the most frequently involved level. Gait disturbance, variable degree of spasticity, discomfort in chest and abdomen, hand numbness were the most obvious signs. Magnetic resonance(MR) images showed that central disc herniation was revealed in 16 cases, and accompanying cord signal changes in 4. Postoperatively, 23 patients showed favorable results (excellent, good and fair) according to Herkowitz's scale. Conclusion : Anterior cervical discectomy and fusion effectively reduced myelopathic symptoms due to soft cervical disc herniation. The authors assured that the shorter duration of clinical attention, the lesser the degree of myelopathy and better outcome in discogenic myelopathy.

• Journal of Korean Neurosurgical Society
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• 제42권1호
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• pp.42-45
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• 2007

Spinal cord lipomas are commonly associated with spinal dysraphism. The lipomas without spinal dysraphism have been reported to be only 1% of all spinal cord lipomas. We report two cases of patients with spinal intramedullary lipomas without dysraphism. One patient was a 57-year-old man who had lower back pain and right-sided sciatica for 20 years. Magnetic resonance imaging (MRI) of the spine demonstrated an intradural mass occupying L1 to L2. The other patient was a 27-year-old woman who had back pain and gait disturbance for 5 months. MRI of the spine showed an elongated intradural mass occupying T7 to T9. Total laminectomy with partial resection of the lesions was performed on both patients. Pathological studies confirmed the diagnosis of spinal cord lipoma. They exhibited no dysraphism. Postoperatively, neurological symptoms improved in both patients.

• Journal of Electrical Engineering and Technology
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• 제11권3호
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• pp.675-682
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• 2016

Sudden voltage drops and outages frequently disturb the operation of sensitive loads for domestic, commercial, and industrial use. In some cases, these events may even impair the functioning of relevant equipment. To maintain power under such conditions, a UPS system is usually installed. Once a disturbance happens at the grid side, the line-interactive UPS system takes over the load to prevent an interruption. But, due to magnetic saturation of the transformer, a significant inrush current may occur for the transformer-coupled loads during this transition. The generation of such transient currents may in turn decrease the line voltage and activates over-current protecting devices of the system. In this work, a cost-effective, line-interactive UPS system is proposed that eliminates the inrush current phenomenon associated with transformer-coupled loads. The strategy was implemented by connecting a standard current-regulated voltage source inverter (CRVSI) to the secondary winding of the load transformer. During any transient condition at the grid side, the load current is monitored and regulated to achieve either seamless compensation of the load current or complete transferal of load from grid to the inverter. Experimental results were obtained for a prototype under all possible operating conditions so as to validate the performance of the proposed topology.