• Korean Journal of Head & Neck Oncology
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• v.28 no.1
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• pp.46-49
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• 2012

Primary tumors of the parapharyngeal space are rare and account for only 0.5% of head and neck neoplasm. About 80% of parapharyngeal tumors are benign and 20% are malignant. Parapharyngeal space is classified into the Prestyloid space and the Poststyloid space. The Poststyloid tumors are usually benign lesions such as neurogenic tumors, paragangliomas, vascular tumors, or aneurisms. The origins of prestyloid tumors are much more diverse pathology, the pleomorphic adenoma in parotid deep lobe is most common type. Several surgical approaches have been introduced for management of parapharyngeal tumor, such as transcervical, transparotid-transcervical and the transcervical-transmandibular approaches. This paper is aimed to present a large parapharyngeal space tumor removed via transoral approach. It is possible to remove easier by using microdebrider. The pathologic diagnosis was pleomorphic adenoma.

• Korean Journal of Head & Neck Oncology
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• v.24 no.2
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• pp.214-216
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• 2008

Parapharyngeal space tumors are extremely rare accounting for about 0.5% of all head and neck tumors and treat mostly by surgical removal. Due to their inherent location, they present with varied non-specific signs and symptoms, resulting in a delay in diagnosis and unnecessary procedures, such as a 'tonsillectomy' or 'incision and drainage' of a 'quinsy'. We recently confirmed a case about a the neurilemnoma on parapharyngeal space during tonsillectomy. To present our experience with the transoral approach for parapharyngeal space tumor and describe our technique for removal of these neoplasms. Although parapharyngeal space tumours are uncommon, recognizing them would enable the correct sequence of investigations, instead of unnecessary procedures resulting in an increased morbidity for the patient.

• Journal of Astronomy and Space Sciences
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• v.32 no.4
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• pp.419-425
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• 2015

In this study, a new idea for developing a space scale for measuring mass in a microgravity environment was proposed by using the inertial force properties of an object to measure its mass. The space scale detected the momentum change of the specimen and reference masses by using a load-cell sensor as the force transducer based on Newton's laws of motion. In addition, the space scale calculated the specimen mass by comparing the inertial forces of the specimen and reference masses in the same acceleration field. By using this concept, a space scale with a capacity of 3 kg based on the law of momentum conservation was implemented and demonstrated under microgravity conditions onboard International Space Station (ISS) with an accuracy of ${\pm}1g$. By the performance analysis on the space scale, it was verified that an instrument with a compact size could be implemented and be quickly measured with a reasonable accuracy under microgravity conditions.

• Korean Journal of Head & Neck Oncology
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• v.12 no.1
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• pp.43-46
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• 1996

An unusual case of nodal metastases from thyroid neoplasm known as parapharyngeal space mass is likely to be overlooked. And identification of the primary lesion by excisional biopsy calls for a secondary operation. Therefore, it is important to be aware of the possible lymphatic spread of the thyroid neoplasm to the parapharyngeal space. In this case, completion thyroidectomy should be considered. Here, we present a case of thyroid papillary carcinoma masquerading as a parapharyngeal space tumor. The mass was removed by transcervical approach and pathologically diagnosed as a metastatic thyroid papillary carcinoma. Successful results were obtained after additional completion thyroidectomy.

• Korean Journal of Head & Neck Oncology
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• v.26 no.2
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• pp.259-261
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• 2010

The meningiomas are slowly growing tumors arising from meningoepithelial cells and they generally occur in the intracranial space. Tumor extension to the extracranial structures occurred in about 20 percent of intracranial meningiomas. Meningiomas extending to the cervical area are uncommom. Beacuse these patients complain of localized symptoms, sometimes those tumors have been operated as cervical tumors. In this report, we incidentally found a meningioma in the left parapharyngeal space in a 63-year-old female, who was confirmed by histopathologic diagnosis to have meningioma. We report herewith this case with the review of literatures.

• Advances in biomechanics and applications
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• v.1 no.4
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• pp.253-267
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• 2014

The human head is identified as the body region most frequently involved in life-threatening injuries. Extensive research based on experimental, analytical and numerical methods has sought to quantify the response of the human head to blunt impact in an attempt to explain the likely injury process. Blunt head impact arising from vehicular collisions, sporting injuries, and falls leads to relative motion between the brain and skull and an increase in contact and shear stresses in the meningeal region, thereby leading to traumatic brain injuries. In this paper the properties and material modeling of the subarachnoid space (SAS) as it relates to Traumatic Brain Injuries (TBI) is investigated. This was accomplished using a simplified local model and a validated 3D finite element model. First the material modeling of the trabeculae in the Subarachnoid Space (SAS) was investigated and validated, then the validated material property was used in a 3D head model. In addition, the strain in the brain due to an impact was investigated. From this work it was determined that the material property of the SAS is approximately E = 1150 Pa and that the strain in the brain, and thus the severity of TBI, is proportional to the applied impact velocity and is approximately a quadratic function. This study reveals that the choice of material behavior and properties of the SAS are significant factors in determining the strain in the brain and therefore the understanding of different types of head/brain injuries.

• International Journal of Aeronautical and Space Sciences
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• v.11 no.3
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• pp.184-192
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• 2010

In this paper, an initial fine alignment algorithm, which is developed for the strap-down inertial navigation systems of satellite launch vehicles, is considered. For fast and accurate alignment, a simple closed-loop estimation algorithm using a proportional-integral controller is introduced. Through computer simulation for the sway condition in the launch pad, it is shown that a simple filter structure can guarantee fast computational speed that is adequate for real-time implementation as well as the required alignment accuracy and robustness. In addition, its implementation results are presented for the Naro-1 flight test.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.37 no.5
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• pp.470-475
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• 2009

This paper is the study which is head tracker using pattern matching. Proposal algorithm obtains initial attitude of head tracker using pattern matching. Optical head tracker consists of infrared LEDs(features) which are attached helmet as pattern, stereo infrared cameras. Proposal algorithm analyzes patterns by error rate of feature distance and estimates feature characteristic number. Initial attitude of head tracker is obtained to compare map data and feature characteristic number.

• 제어로봇시스템학회:학술대회논문집
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• 2003.10a
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• pp.663-668
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• 2003

This paper presents a new observation system which is useful to observe the scene of the remote controlled robot vision. This system is composed of a motionless camera and head motion detector with a motion sensor. The motionless camera has a fish eye lens and is for observing a hemisphere space. The head motion detector has a motion sensor is for defining an arbitrary subspace of the hemisphere space from fish eye lens. Thus processing the angular information from the motion sensor appropriately, the direction of face is estimated. However, since the fisheye image is distorted, it is unclear image. The partial domain of a fish eye image is selected by head motion, and this is converted to perspective image. However, since this conversion enlarges the original image spatially and is based on discrete data, crevice is generated in the converted image. To solve this problem, interpolation based on an intensity of the image is performed for the crevice in the converted image (space problem). This paper provides the experimental results of the proposed observation system with the head motion detector and perspective image conversion using the proposed conversion and interpolation methods, and the adequacy and improving point of the proposed techniques are discussed.

• International Journal of Aeronautical and Space Sciences
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• v.11 no.4
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• pp.303-312
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• 2010

This paper introduces the upper stage attitude control system of KSLV-I, which is the first space launch vehicle in Korea. The KSLV-I upper stage attitude control system consists of two electro-hydraulic actuators and a reaction control system using cold nitrogen gas. A proportional, derivative, and integral controller is designed for the electro-hydraulic thrust vectoring system, and Schmidt trigger ON/OFF controllers are designed for the reaction control system. Each attitude controller is designed to have enough stability margins. The stability and performance of KSLV-I upper stage attitude control system is verified via hardware in the loop tests. Hardware in the loop tests are accomplished for perturbed flight conditions as well as nominal flight condition. The test results show that the attitude control loop of KSLV-I upper stage is very stable and the attitude controllers perform well for all flight conditions. Attitude controllers designed in this paper have been successfully applied to the first flight of KSLV-I on August 25, 2009. The flight test results show that all attitude controllers of the KSLV-I upper stage performed well and satisfied the accuracy specifications even during abnormal flight conditions.