• The Transactions of the Korea Information Processing Society
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• v.13 no.4
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• pp.189-198
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• 2024

Lipreading is one of the important parts of speech recognition, and several studies have been conducted to improve the performance of lipreading in lipreading systems for speech recognition. Recent studies have used method to modify the model architecture of lipreading system to improve recognition performance. Unlike previous research that improve recognition performance by modifying model architecture, we aim to improve recognition performance without any change in model architecture. In order to improve the recognition performance without modifying the model architecture, we refer to the cues used in human lipreading and set other regions such as chin and cheeks as regions of interest along with the lip region, which is the existing region of interest of lipreading systems, and compare the recognition rate of each region of interest to propose the highest performing region of interest In addition, assuming that the difference in normalization results caused by the difference in interpolation method during the process of normalizing the size of the region of interest affects the recognition performance, we interpolate the same region of interest using nearest neighbor interpolation, bilinear interpolation, and bicubic interpolation, and compare the recognition rate of each interpolation method to propose the best performing interpolation method. Each region of interest was detected by training an object detection neural network, and dynamic time warping templates were generated by normalizing each region of interest, extracting and combining features, and mapping the dimensionality reduction of the combined features into a low-dimensional space. The recognition rate was evaluated by comparing the distance between the generated dynamic time warping templates and the data mapped to the low-dimensional space. In the comparison of regions of interest, the result of the region of interest containing only the lip region showed an average recognition rate of 97.36%, which is 3.44% higher than the average recognition rate of 93.92% in the previous study, and in the comparison of interpolation methods, the bilinear interpolation method performed 97.36%, which is 14.65% higher than the nearest neighbor interpolation method and 5.55% higher than the bicubic interpolation method. The code used in this study can be found a https://github.com/haraisi2/Lipreading-Systems.

• Applied Microscopy
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• v.28 no.3
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• pp.255-262
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• 1998

This study was performed to observe the morphological changes of the synaptic structures in the interpolar part of the spinal trigeminal nucleus of rat during aging. Transmission electron microscopy has been used to determine the r)umber of synapses, length of postsynaptic densities, number and area of axon terminals. Sprague-Dawley rat 3, 12, 24 and 36 months of age were used in this study. 1. The number of synapses was 51.7, 43.1, 28.4 and 16.8 in the 3, 12, 24 and 36 months of age respectively. Therefore, the number of synapses decreased gradually with age, but decreased significantly in the 24 and 36 months. 2. The length of postsynaptic densities was $30.2{\mu}m,\;23.6{\mu}m,\;10.4{\mu}m\;and\;4.9{\mu}m$ in the 3, 12, 24 and 36 months of age respectively. Therefore, the length of postsynaptic densities decreased gradually with age, but decreased significantly in the 24 and 36months. 3. The number of axon terminals was 84.3, 73.7, 51.4 and 26.6 in the 3, 12, 24 and 36 months of age respectively. Therefore, the number of axon terminals decreased gradually with age, but decreased significantly in the 24 and 36months. 4. The area of axon terminals was $76.1{\mu}m^2,\;64.1{\mu}m^2,\;29.9{\mu}m^2\;and\;13.8{\mu}m^2$ in the 3, 12, 24 and 36 months of age respectively. Therefore, the area of axon terminals decreased gradilally with age, but decreased significantly in the 24 and 36 months. The results suggest that there are the changes of the synaptic structures in the interpolar part of spinal trigeminal nucleus of rat during aging. These changes nay be concerned to the decreased function of mediating pain and temperature sensation in the face and oral cavity during aging.

• Journal of Korean Neurosurgical Society
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• v.29 no.1
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• pp.118-125
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• 2000

Objective : Trigeminal neurinomas are rare tumors that may locate in the middle fossa or posterior fossa and straddled both the middle and posterior fossa, according to their origin in the nerve complex. The aim of this study was to analyze the clinical presentation, operative approaches employed and outcome in 15 patients who were treated surgically, with special emphasis on surgical approach. Method : Between 1994 and 1998, a total of fifteen patients were histopathologically identified as neurinomas originating from the trigeminal nerve complex at the tumor clinic in the neuroscience center of the our university. Results : The surgical approach to these tumors depends on their anatomical location and tumor size. Six patients had tumors confined to the middle fossa, five patients had tumors limited to the posterior fossa, and four patients both in middle and posterior fossa components of their tumors. Nine neurinomas were removed via the conventional approach(pterional, subtemporal, suboccipital) and six were excised using skull base approach(transzygomatic subtemporal, orbitozygomatic, transpetrosal). Total resection of the tumor was possible in 10 cases. Total resection of tumor was accomplished in 83% of patients following skull base approach compared with 56% of patients following conventional approach. The surgical outcome was excellent or good in 13 cases, fair in one and, poor in one. There was no operative death. In the immediate postoperative period, aggravation of preoperative facial hypesthesia and 6th cranial nerve palsy were common. Although, these deficits were generally transient, eight patients remained with some degree of trigeminal hypesthesia, two had facial weakness, one neurotrophic keratitis, one diplopia, and one mastication difficulty. Conclusion : Surgical approach to the trigeminal neurinoma depends on the tumor location and tumor size. Skull base approach provides more complete tumor excision without increased morbidity compared to conventional approach. Surgeons have to be meticulous in order to reduce postoperative complication.

• Journal of Oral Medicine and Pain
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• v.33 no.3
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• pp.279-294
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• 2008

This study aimed to make an analysis of the occlusion in the state of muscle fatigue produced by excessive mouth opening and clenching during the dental treatment to control the dental pain and to evaluate the sensory nerve in the muscle pain state. Most of the reasons why patients visit the dental office result in pain-either conceivably the dental origin pain or the non-dental origin pain. The dental offices have many therapeutic actions to produce the masticatory muscle fatigue for the treatment. Dental treatment with long minutes of mouth opening can cause some headaches, masticatory muscle pain and mouth opening difficulties. Patients with mastication problems who visits a dental office to alleviate pain run against another unexpected pain with other aspects. This study uses T-scan II system(Tekscan Co., USA) for the evaluation on the occlusal pattern in the experimental muscle fatigue after clenching, opening the mouth excessively and chewing gum. The occlusal contact pattern is analyzed by the contact timing, namely first, intercuspal, maximum and end point of contact. This inspection was performed at frequencies of 2000Hz, 250 Hz and 5 Hz before and after each experimental muscle pain was produced to 24 subjects who had normal occlusion without the orthodontic treatment or a wide range of the prosthesis by using $neurometer^{\circledR}$ CPT/C(Neurotron, Inc. Baltimore, Maryland, USA). The measuring sites were mandibular nerve experimental muscle fatigue respectively. This study could obtain the following results after the assessment of occlusion and sensory nerve of the experimental muscle fatigue. 1. There were the fastest expression after the excessive mouth opening in muscle fatigue and after tooth clenching in muscle pain. In the visual analog scale that records the subjective level, there was the highest scale after the clenching in the muscle fatigue in jumping off the point of pain. 2. Tooth contact time, contact force, relative contact force on the point of the first contact had no difference, and there were decreases in the contact force after the excessive mouth opening on intercuspal position point, after the excessive mouth opening and the gum chewing on the point of the maximum, and in the contact time after all the experimental muscle fatigue state on the point of the end contact. 3. There was no statistic significance in the current perception threshold before and after the experimental muscle fatigue. 4. There was no significant difference in the contact number, the maximal contact number on the point of the first contact, and the contact number after the mouth opening and gum chewing on the point of the intercuspal position and the contact number after the experimental muscle fatigue on the maximum point, and showed significant decreases. In conclusion, it was found that the occlusal pattern can cause the changes on the case of the clinical muscle weakness by intra-external oral events. It was important that the sedulous attention to details is required during dental treatment in case of excessive mouth opening, mastication and clenching.

• Investigative Magnetic Resonance Imaging
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• v.14 no.2
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• pp.103-114
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• 2010

Purpose : To generate a Korean specific brain template, especially in patients with Alzheimer's disease (AD) by optimizing the voxel-based analysis. Materials and Methods : Three-dimensional T1-weighted images were obtained from 123 subjects who were 43 cognitively normal subjects and patients with 44 mild cognitive impairment (MCI) and 36 AD. The template and the corresponding aprior maps were created by using the matched pairs approach with considering differences of age, gender and differential diagnosis (DDX). We measured several characteristics in both our and the MNI templates, including in the ventricle size. Also, the fractions of gray matter and white matter voxels normalized by the total intracranial were evaluated. Results : The high resolution template and the corresponding aprior maps of gray matter, white matter (WM) and CSF were created with the voxel-size of $1{\times}1{\times}1\;mm$. Mean distance measures and the ventricle sizes differed between two templates. Our brain template had less gray matter and white matter areas than the MNI template. There were volume differences more in gray matter than in white matter. Conclusion : Gray matter and/or white matter integrity studies in populations of Korean elderly and patients with AD are needed to investigate with this template.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• v.30 no.1
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• pp.1-16
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• 2004

The use of artificial nerve conduit containing viable Schwann cells is one of the most promising strategies to repair the peripheral nerve injury. To fabricate an effective nerve conduit whose microstructure and internal environment are more favorable in the nerve regeneration than existing ones, a new three-dimensional Schwann cell culture technique using $Matrigel^{(R)}$. and dorsal root ganglion (DRG) was developed. Nerve conduit of three-dimensionally arranged Schwann cells was fabricated using direct seeding of freshly harvested DRG into a $Matrigel^{(R)}$ filled silicone tube (I.D. 1.98 mm, 14 mm length) and in vitro rafting culture for 2 weeks. The nerve regeneration efficacy of three-dimensionally cultured Schwann cell conduit (3D conduit group, n=6) was assessed using SD rat sciatic nerve defect of 10 mm, and compared with that of silicone conduit filled with $Matrigel^{(R)}$ and Schwann cells prepared from the conventional plain culture method (2D conduit group, n=6). After 12 weeks, sciatic function was evaluated with sciatic function index (SFI) and gait analysis, and histomorphology of nerve conduit and the innervated tissues of sciatic nerve were examined using image analyzer and electromicroscopic methods. The SFI and ankle stance angle (ASA) in the functional evaluation were $-60.1{\pm}13.9$, $37.9^{\circ}{\pm}5.4^{\circ}$ in 3D conduit group (n=5) and $-87.0{\pm}12.9$, $32.2^{\circ}{\pm}4.8^{\circ}$ in 2D conduit group (n=4), respectively. And the myelinated axon was $44.91%{\pm}0.13%$ in 3D conduit group and $13.05%{\pm}1.95%$ in 2D conduit group to the sham group. In the TEM study, 3D conduit group showed more abundant myelinated nerve fibers with well organized and thickened extracellular collagen than 2D conduit group, and gastrocnemius muscle and biceps femoris tendon in 3D conduit group were less atrophied and showed decreased fibrosis with less fatty infiltration than 2D conduit group. In conclusion, new three-dimensional Schwann cell culture technique was established, and nerve conduit fabricated using this technique showed much improved nerve regeneration capacity than the silicone tube filled with $Matrigel^{(R)}$ and Schwann cells prepared from the conventional plain culture method.

• Journal of Korean Neurosurgical Society
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• v.29 no.5
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• pp.650-658
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• 2000

Objective : To evaluate the role of Gamma Knife radiosurgery in essential and tumor-related(secondary) trigeminal neuralgia, outcomes of radiosurgery and microsurgery were compared each other. Methods : Five patients with essential trigeminal neuralgia underwent stereotactic radiosurgical treatment with Leksell Gamma Knife and twenty five patients were treated with microsurgery during the same period(1994. 1-1997. 6). A 4-mm collimator was used and REZ or proximal portion of trigeminal nerve was targeted with maximal dose of 60-72Gy. The mean follow-up after radiosurgery was 39.4 months and that after microsurgery was 47.9 months. Results : At the last follow-up, four patients(80%) had excellent(pain free) or good(50-90% pain relief) outcomes, one(20%) had poor control after radiosurgical treatment. Twenty-three patients(92%) had excellent or good outcomes and two(8%) had poor results after microsurgery. Postoperative complications occurred in ten(40%) with microsurgery, but there were no complications in patients with Gamma Knife radiosurgery. Six patients with secondary trigeminal neuralgia received radiosurgical treatment directed at their tumors, and three patients were surgically treated. Three of six(50%) patients treated with Gamma Knife had pain relief while two of three patients with surgical treatment showed immediate pain relief. Post-treatment complications were developed in two of six radiosurgical patients and in one of three surgical patients. Conclusion : Gamma Knife stereotactic radiosurgery may be considered as a useful and alternative option for the treatment of essential and secondary trigeminal neuralgia owing to of its safety and less complications. The preliminary results obtained in our series appear encouraging, although the outcome is not so good as that of surgery.

• Journal of Veterinary Clinics
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• v.33 no.4
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• pp.234-236
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• 2016

A 14 kg, 9-year-old, spayed female, Cocker Spaniel was presented to the Veterinary Medical Teaching Hospital of Seoul National University with a history of head tilt and circling. Otitis externa and media were diagnosed by computerized tomography, and total ear canal ablation was performed. In preanesthetic evaluation, systemic hypertension and second-degree atrioventricular block were observed, but there was no regurgitation through the heart valves. Systemic hypertension was managed with amlodipine (0.1 mg/kg, PO, BID) for the anesthesia. The dog was premedicated with cefazolin (22 mg/kg, IV) and midazolam (0.2 mg/kg, IV). Anesthesia was induced with alfaxalone (2 mg/kg, IV) and maintained with isoflurane and 100% oxygen following intubation. During surgery, vital signs (heart rate, respiratory rate, blood pressure, end tidal carbon dioxide partial pressure and body temperature) were maintained within normal ranges, but bradycardia was observed and corrected with glycopyrrolate (5 ug/kg IV, twice). During subcuticular suture, electrohemostasis was applied at the incision line, which was close to the trigeminal nerve. In no time at all, heart rate dramatically decreased from 110 to 60 beats per minute. No additional treatment was done because mean blood pressure was maintained above 70 mmHg. The heart rate recovered according to the decrease of end tidal isoflurane concentration and there were no complications associated with the anesthesia and surgery. Sudden bradycardia after electrical stimulation around the trigeminal nerve was considered as trigeminocardiac reflex (TCR). It is recommended to be careful of bradycardia from TCR when electrocautery is used in the craniofacial area during surgery.

• Investigative Magnetic Resonance Imaging
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• v.16 no.2
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• pp.124-135
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• 2012

Purpose : The objective of this study was to investigate the differences of hippocampal volume and shape as well as the functional change between long life experienced taxi drivers and controls of Korean population. Materials and Methods: Three-dimensional T1-weighted images and blood oxygen level dependent functional MRI(fMRI) were obtained from 8 subjects, consisting of 4 experienced (20-30 years) taxi drivers and 4 age-matched controls. The hippocampal volume and shape were analyzed with three-dimensional T1-weighted images. In addition, neuronal activities of brain were analyzed using a blood oxygen level dependent fMRI between the two groups. Results: The hippocampal volume showed no statistically significant difference between the two groups (p > 0.05). The left hippocampi of the taxi drivers were slightly elongated with larger head and tail portions than those of the controls (p < 0.05, uncorrected). For the functional MRI, fusiform gyrus was specifically activated in taxi drivers, compared with the control group. Conclusion: The structural and functional changes of taxi driver's hippocampus indicate the functional differentiation as a result of occupational dependence on spatial navigation. In other words, the continuous usage of spatial navigation performance may diminish degeneration of hippocampus and the related brain regions.

• Radiation Oncology Journal
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• v.12 no.1
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• pp.109-115
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• 1994

The purpose of this paper is to develop an efficient method for the quick determination of multiple isocenters plans to provide optimal dose distribution in sterotactic radiosurgery. A Spherical dose model was developed through the use of fit to the exact dose data calculated in a 18cm diameter of spherical head phantom. It computes dose quickly for each spherical part and is useful to estimate dose distribution for multiple isocenters. An automatic computer search algorithm was developed using the relationship between the isocenter move and the change of dose shape, and adapted with a spherical dose model to determine isocenter separation and cellimator sizes quickly and automatically. A spheric81 dose model shows a comparable isodose distribution with exact dose data and permits rapid calculations of 3-D isodoses. the computer search can provide reasonable isocenter settings more quickly than trial and error types of plans, while producing steep dose gradient around target boundary. A spherical dose model can be used for the quick determination of the multiple isocenter plans with 3 computer automatic search. Our guideline is useful to determine the initial multiple isocenter plans.