• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 2003년도 ICCAS
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• pp.1315-1318
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• 2003

In this paper, a neural network based approach using a self-organizing feature map is proposed for the segmentation of X ray images. A number of algorithms based on such approaches as histogram analysis, region growing, edge detection and pixel classification have been proposed for segmentation of general images. However, few approaches have been applied to X ray image segmentation because of blur of the X ray image and vagueness of its edge, which are inherent properties of X ray images. To this end, we develop a new model based on the neural network to detect objects in a given X ray image. The new model utilizes Mumford-Shah functional incorporating with a modified adaptive SOFM. Although Mumford-Shah model is an active contour model not based on the gradient of the image for finding edges in image, it has some limitation to accurately represent object images. To avoid this criticism, we utilize an adaptive self organizing feature map developed earlier by the authors.[1] It's learning rule is derived from Mumford-Shah energy function and the boundary of blurred and vague X ray image. The evolution of the neural network is shown to well segment and represent. To demonstrate the performance of the proposed method, segmentation of an industrial part is solved and the experimental results are discussed in detail.

• JSTS:Journal of Semiconductor Technology and Science
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• 제12권2호
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• pp.230-239
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• 2012

In this paper, we present the radio-frequency (RF) modeling for gate-all-around (GAA) junctionless (JL) MOSFETs with 30-nm channel length. The presented non-quasi-static (NQS) model has included the gate-bias-dependent components of the source and drain (S/D) resistances. RF characteristics of GAA junctionless MOSFETs have been obtained by 3-dimensional (3D) device simulation up to 1 THz. The modeling results were verified under bias conditions of linear region (VGS = 1 V, VDS = 0.5 V) and saturation region (VGS = VDS = 1 V). Under these conditions, the root-mean-square (RMS) modeling error of $Y_{22}$-parameters was calculated to be below 2.4%, which was reduced from a previous NQS modeling error of 10.2%.

• 대한임상독성학회지
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• 제15권1호
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• pp.47-50
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• 2017

Nitrogen is an inert gas that is harmless to humans under normal conditions. While it is not inherently toxic, nitrogen gas becomes dangerous when it displaces oxygen, resulting in suffocation. Herein, we report a case of a 34-year-old man who attempted suicide by nitrogen asphyxiation who presenting with decreased mental function and agitation. Lactic acidosis and hyperammonemia were observed on presentation at the emergency department, but these improved after a few hours. After 2 days, the patient regained full consciousness, and was discharged without any complications. Survival after asphyxiation due to nitrogen gas is very rare, and these patients are more likely to have poorer outcomes. There is a potential for the increasing use of nitrogen gas as a method of committing suicide because of the ease of access to this gas.

• Journal of Korean Neurosurgical Society
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• 제56권5호
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• pp.428-430
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• 2014

Isolated traumatic pseudoaneurysms of the basilar artery are extremely rare but often fatal resulting in a mortality rate as high as 50%. A 51-year-old man presented with craniofacial injury after blunt trauma. A brain computed tomography (CT) scan showed thick basal subarachnoid hemorrhage associated with multiple craniofacial fractures, while CT angiography revealed contrast extravasation at the distal basilar artery with pseudoaneurysm formation. After this primary survey, the condition of the patient suddenly deteriorated. Conventional angiography confirmed the contrast extravasation resulted from pseudoaneurysm formation, which was successfully treated with endovascular coil embolization. Decompressive craniectomy and coma therapy with propofol were also performed. However, the patient died on the 7th hospital day because of the poor initial clinical condition. The current case is the first report of acute pseudoaneurysm rupture arising from the basilar artery within the first day after trauma. Our findings suggest the possibility that pseudoaneurysm rupture should be considered if brain CT shows thick traumatic subarachnoid hemorrhage on the basal cistern with a basal skull fracture.

• 한국정밀공학회지
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• 제27권11호
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• pp.92-97
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• 2010

The object of this study is to investigate the definite method for pitting damaged surfaces. Pitting is a sort of fatigue damages and it is made by a repetitive load. For a judgment between damages or not, sensing vibrations of test equipment is simple. However, it is not only difficult to observe a growth of pitting but also impossible to detect the juncture of initial pitting. Therefore, a method for the pitting damaged area measuring technique was effectively implemented by Two Roller Machine. The change of surface damaged area was measured by an optical microscope in regular time and calculated by the use of dark and bright ratio of test specimens' pictures taken by optical microscope. In conclusion, S - N Curves gained by Failure rate - Cycle graph was led and the curves are able to be chosen as occasion demands for a failure area percentage.

• 대한기계학회논문집A
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• 제20권2호
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• pp.481-487
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• 1996

A snapping-beam microswitch has been designed, fabricated and tested. From a design analysis, necessary and sufficient conditions for a snap-through switching fouction have been derived for a clamped shallow beam. The necessary condition has resulted in a geometric relation, in which the ratio of beam thickness to initial beam deflection plays a key role in the snapping ability. The sufficient condition for the snapping action has been obtained as a function of the inertia force due to applied acceleration, and the electrostatic force, adjustable by an inter-electrode voltage. For experimental investigations, a set of microbeams of silicon dioxide/$P^+$silicon bimorphs have been fabricated. Geometric size and mechanical behavior of each material film have been measured from on-chip test structures. Estimated and measured characteristics of the fabricated devices are compared.

• Journal of Korean Neurosurgical Society
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• 제29권6호
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• pp.822-825
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• 2000

Lymphocytic infundibuloneurohypophysitis is a rare inflammatory disorder, which may be caused by autoimmune response, affecting the infundibulum and the posterior lobe of the pituitary gland. The authors present a 15-year-old man with central diabetes insipidus, whose sellar magnetic resonance imaging (MRI) showed a focal thickening of the infundibulum and loss of high signal of the normal neurohypophysis on T1-weighted images. The histopathological diagnosis was lymphocytic infundibuloneurohypophysitis. When a patient presents with central diabetes insipidus and infundibular thickening on brain MRI, this entity should be included in the differential diagnosis though it is very rare. The significance of this entity in treatment is that it is basically not a surgical one, and surgery is needed only for tissue diagnosis. Symptomatic treatment and observation make it regress spontaneously.

• Clinical and Experimental Reproductive Medicine
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• 제15권1호
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• pp.61-65
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• 1988

Retrograde ejaculation, an infrequent cause of male infertility, may be the sequala of prostate or bladder neck surgery or the result of interruption in the sympathetic innervation, the diagnosis is established by history and examination of urine. Infertile couple artificial insemination homologous(AIH) using retrograde ejaculate recovered from bladder has been successfully acomplished. In this case, ovulation was induced by clomiphene citrate, osmorality and pH of urine was controlled by buffer solution and immediately specimen collection, to improve sperm mobility. We had experienced a successful pregnancy and delivery case by above method. So here reported with brief review of literature.

• 대한두경부종양학회지
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• 제7권2호
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• pp.114-119
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• 1991

Malignant oncocytoma(oxyphil cell adenoma) is a extremely rare malignant tumor of the salivary glands and almost occurs in the parotid gland. A case of malignant oncocytoma of the parotid gland occurring in a 63 year old man is reported. Establishing a diagnosis of malignant oncocytoma essentially requires the application of two sets of criteria to the tumor under examination. First, the tumor cells must be identified as oncocyte and second, malignancy must be determined. Histochemical stains are not as useful as generally believed. Electron microscopy confirms the diagnosis by demonstrating an abundance of mitochondria. The diagnosis of malignant oncocytoma depends on several additional criteria in addition to cellular and nuclear pleomorphism, including lack of encapsulation, local infiltration, perineural and intravascular growth, and regional and/or distant metastasis. Satisfactory results from surgical resection and postoperative radiotherapy in our patient serve as additional experience in the treatment of this rare malignancy.

• Journal of Yeungnam Medical Science
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• 제8권2호
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• pp.222-226
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• 1991

In advant of high-resolutional CT and MRI, it is not so difficult to detect the lumbar synovial cyst, however the unusual disease should be included in the differential diagnosis of cauda equina compression syndromes. The case of a 55-year-old man who had a low back pain and severe radiating pain on both legs showed a retrolisthesis at L3-4 and L4-5 and epidural enhansing mass just around L4-5 facet joint on MRI. Microscopically a lining of synovial tissue was demonstrated. After surgery of the total resection of synovial cyst and stabilization, the patient's presenting symptoms were improved.