• Korean Journal of Head & Neck Oncology
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• v.9 no.2
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• pp.183-192
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• 1993

This study reports a prospective analysis of anatomical variations of recurrent laryngeal nerves during 300 thyroidectomies. During thyroidectomies for variable thyroid diseases. the course of recurrent laryngeal nerve was completely isolated from root of neck to the inferior comus of thyroid cartilage. In left side, nerve(53.7%) predominantly ran posterior to the inferior thyroidal artery(p<0.05) but in right side there was no predominant pattern. There were three nonrecurrent laryngeal nerves in the right side. About half of the cases in both sides(51.2% in right, 50.5% in left side) had one or more branches before terminating at cricothyroidal muscles. The average length of branches from inferior comus of thyroid cartilage to the origination of individual branch were l2.0mm in right side and 13.3mm in left side. In right side, majority(50.7%) of nerves ran though paratracheal space but difference did not reach the statistical but in left side, majority(88.3%) ran through tracheoesophageal groove and it was the dominant pattern(p<0.01), the overall status of passages of the nerve were relatively straight in left side(straight 87.8%, oblique 52.1%).

• Journal of the Korean Institute of Intelligent Systems
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• v.15 no.5
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• pp.552-559
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• 2005

Recurrent neural networks(RNNs) trained with gradient based such as real time recurrent learning(RTRL) has a drawback of slor convergence rate. This algorithm also needs the derivative calculation which is not trivialized in error back propagation process. In this paper a derivative free Kalman filter, so called the unscented Kalman filter(UKF), for training a fully connected RNN is presented in a state space formulation of the system. A derivative free Kalman filler learning algorithm makes the RNN have fast convergence speed and good tracking performance without the derivative computation. Through experiments of nonlinear channel equalization, performance of the RNNs with a derivative free Kalman filter teaming algorithm is evaluated.

• Kyungpook Mathematical Journal
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• v.46 no.3
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• pp.417-423
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• 2006

The object of the present paper is to study a conformally flat quasi-Einstein space and its hypersurface.

• Communications of the Korean Mathematical Society
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• v.22 no.3
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• pp.411-417
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• 2007

N(k)-quasi Einstein manifolds are introduced and studied.

• Imaging Science in Dentistry
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• v.38 no.2
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• pp.117-120
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• 2008

The odontogenic keratocyst (OKC) is a developmental odontogenic cyst typically occurring in the jaws. Since the first description of OKC was published in 1956, the lesion has been of particular interest because of its specific histopathologic features, high recurrence rate, and aggressive behavior. Recurrences most commonly arise within bone at the site of the original cyst. However, as lining cells may find their way into surrounding tissues either from implantation during surgery or from cortical perforation recurrences may arise at a distance from the original cyst. Here, we report a rare case of recurrent OKC which was first developed in mandible and recurred within the masticatory space.

• Proceedings of the Korean Institute of Intelligent Systems Conference
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• 1993.06a
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• pp.1005-1008
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• 1993

Supervised learnmg 01 recurrent neural networks (RNNs) is discussed. First, we review the present state of art, featuring their major properties in contrast of those of the multilayer neural networks. Then, we concisely describe one of the most practical learning algorithms, i.e. backpropagation through time. Revising the basic formulation of the learning algorithms, we derive a general formula to solve for the exact solution(s) of the whole connection weights w of RNNs. On this basis we introduce a novel interpretation of the supervised learning. Namely, we define a multidimensional Euclidean space, by assigning the cost function E(w) and every component of w to each coordinate axis. Since E=E(w) turns up as a hyper surface in this space, we refer to the surface as learning surface. We see that topological features of the learning surface are valleys and hills. Finally, after explicating that the numerical procedures of learning are equivalent to descending slopes of the learning surface along the steepest gradient, we show that a minimal value of E(w) is the intersection of curved valleys.

• Journal of Chest Surgery
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• v.24 no.8
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• pp.792-796
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• 1991

Immature teratoma can be viewed as intermediate between mature teratoma and embryonal carcinoma. Unlike the mature teratoma, elements of the three perm cell layers are incompletely differentiated and not arranged in organoid fashion In some area, more mature forms of these tissues may also be seen, Although this tumor is clearly malignant, they may not display clear-cut cytologic features of malignancy. The clinical prognosis is poor. We have experienced one case of recurrent immature teratoma. In first operation[1987, April], tumor of anterior mediastinum was removed with wedge resection of ant. segment of RUL % med. segment of RML. In 2nd operation[1990, June], recurrent teratoma of right inner thoracic wall was resected with partial 5th rib resection and wedge resection of lat. segment of middle lobe. Two months later, the 3rd operation[1990, September] was done, which was a removal of mass on thoracic wall near sup, segment of RLL and partial rib resection of 3rd, 4th & 5th. In November 1990, last operation[4th operation] was made. It was enucleation of walnut sized tumor located between medial segment of RML, and 4th. intercostal space, well encapsulated with endothoracic fascia and invaded into lung parenchyme, Adjuvant chemotherapy was done after each operation, but radiotherapy[5000 Rad] was done only after 1st operation. There was no evidence of recurrence after last operation. The patient is well-being still now.

• Publications of The Korean Astronomical Society
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• v.30 no.2
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• pp.237-240
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• 2015

Classical novae (CNe) are interacting binary systems whose outbursts are powered by a thermonuclear runaway in accreted material onto the surface of a white dwarf (WD). The secondary star in such systems fills its Roche lobe and material is transferred onto the WD primary star via an accretion disk. Recurrent novae (RNe) show many similarities to CNe, but have had more than one recorded outburst. RNe play an important role as one of the suspected progenitor systems of Type Ia supernovae, which are used as primary distance indicators in cosmology. Thus, it is important to investigate the nature of their central binary systems to determine the relation between the parameters of the central system and the outburst type, and finally ascertain the population of novae that might be available to give rise to the progenitors of Type Ia SNe. A low outburst amplitude is adopted as a criterion that may help distinguish RNe from CNe and was therefore used to select targets for observations from ground-based observatories including the Liverpool Telescope and the Southern African Large Telescope as well as the full-sky space-based archive of the Solar Mass Ejection Imager (SMEI). We found that at least four objects currently classified as CNe are possibly RNe candidates based on their quiescent spectra. We also searched the SMEI archive for additional outbursts of bright CNe that might otherwise have been missed but did not find a conclusive example.

• Journal of the Korean Society of Radiology
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• v.83 no.4
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• pp.904-909
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• 2022

Uterine cervical cancer is one of the most common malignancies of the female genital tract. Most recurrent cases of uterine cervical cancer are diagnosed within two years after primary treatment, and late recurrence after a disease-free interval of more than five years is rare. In addition, peritoneal metastases usually present as multifocal discrete nodules in the peritoneal cavity with nodular or diffuse peritoneal thickening. Herein, we report an extremely rare case of late recurrent cervical cancer peritoneal metastasis with an unusual manifestation of a large, solitary necrotic mass in the right subphrenic space on contrast-enhanced CT.

• Journal of Korean Neurosurgical Society
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• v.56 no.6
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• pp.521-526
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• 2014

The authors report a case of symptomatic epidural gas accumulation 2 weeks after the multi-level lumbar surgery, causing postoperative recurrent radiculopathy. The accumulation of epidural gas compressing the dural sac and nerve root was demonstrated by CT and MRI at the distant two levels, L3-4 and L5-S1, where vacuum in disc space was observed preoperatively and both laminectomy and discectomy had been done. However, postoperative air was not identified at L4-5 level where only laminectomy had been done in same surgical field, which suggested the relationship between postoperative epidural gas and the manipulation of disc structure. Conservative treatment and needle aspiration was performed, but not effective to relieve patient's symptoms. The patient underwent revision surgery to remove the gaseous cyst. Her leg pain was improved after the second operation.