• Journal of the Korea Institute of Information and Communication Engineering
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• v.18 no.5
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• pp.1096-1102
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• 2014

In remote gaze tracking system using infra-red LEDs, calibrating the position of reflected light is essential for computing pupil position in captured images. However, there are limitations in reducing errors because variable locations of head and unknown radius of cornea are involved in the calibration process as constants. This study purposes a gaze tracking method based on pupil-corneal reflection that does not require user-calibration. Our goal is to eliminate the correction process of glint positions, which require a prior calibration, so that the gaze calculation is simplified.

• Journal of Biomedical Engineering Research
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• v.25 no.3
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• pp.227-233
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• 2004

In this paper, it is proposed that the four channel electrode arrangement at a frontal lobe and the noise reduction method using a JADE for the EEG biofeedback system. The proposed electrode arrangement is based on the retina-cornea dipole model. Using JADE and signals which are acquired by the proposed arrangement, four independent components are separated. To estimate a pure EEG component among four components, it is measured that a ratio of alpha wave to the whole signal and then the component that has a maximum value is considered as a pure EEG which the noise is eliminated. As a result of experiments, the proposed methods are effective in reduction of noises during acquisition of the EEG.

• Journal of Veterinary Clinics
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• v.10 no.2
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• pp.215-220
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• 1993

The anesthetic effects by dosages of Tiletamlne-Zolazepam in the dogs were investigated and then the optimal dosages for the operation of patients were suggested. 1. In groups of T+Z 20, 10 and 5 mg/kg administration, anesthetic periods are 180~300, 33~47 and 40~50 minutes, respectively and complete recovery from anesthesia was shorted with taking 53~72 minutes in the group of 5 mg/kg administration. 2. Reflex responses to eyelids, cornea and pharyngolarynx were maintained but pedal reflexes became considerably sluggish 3. It showed tachycardias on ECG but there were no specific dysrhythmias. On EEG, it showed low voltage-fast waves before anesthesia, high voltage-fast waves in induction stage, low voltage-slow waves in anesthetic stage and high voltage-fast waves again in recovery stage. 4. Surgical procedures could be performed satisfactorily in 6 cases of the 10 mg/kg administration group, but in 3 of 5 cases of 5 mg/kg administration group it could be completed after additional administration. 5. In conclusion, it was considered desirable for anesthetizing dogs that for healthy cases T+Z at the level of 10 mg/kg B.W. was administered, and for poor risk patients, 5 mg/kg B.W., followed by an additional administration in unsatisfied cases.

• Radiation Oncology Journal
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• v.10 no.2
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• pp.155-161
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• 1992

The eye lens is known to be radiosensitive organ and catarat can be induced by relatively low dose of radiation. In the treatment of head and neck tumors, shielding blocks are frequently used to minimize dose on sensitive organs. The shielding block, which is made of high atomic number materials (cerrobend), produce significant dose perturbations in megavoltage photon beams. The effects of these perturbations of eye shielding blocks are measured with film and ion chambers for the treatment of head and neck malignancies. Optimum parameters for the treatment are suggested.

• Journal of Veterinary Clinics
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• v.16 no.1
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• pp.203-209
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• 1999

A 4-year-old female Shih-tzu with severe episcleral congestion and buphthalmos in left eye was referred to the Veterinary Teaching Hospital, Chonnam National University in October 1998. During two months in local veterinary clinics, the dog had been treated unsuccessfully with tarsorrhaphy and antibiotics. By history taking, cause of the glaucoma was ascertained as accidental nonpenetrated cornea trauma by owner, Ophthalmic examination revealed that the left eye was buphthalmic with severe episcleral congestion, pain and fever. The direct pupillary light response could not be evaluated in the left eye, but right eye had normal reaction. The intraocular pressure was 4.5 mmHg in the right eye and 33 mmHg in the left eye, as measured with a Schiotz tonometer, Ultrasonographic finding revealed hyperechoic vitrous body and central echofree material. The Schirmer tear test showed 20 mm in the left eye and 8 mm in the right eye. The hematologic examination revealed monocytosis. The initial medical treatment was admitted, but there was no response. Transpalpebral enucleation in the left eye under inhalation anesthesia with enflurane 1.2 vol% in oxygen was performed. The day after operation the left eye ravealed no exudate, and pain, and the systemic vital signs were normal. The prognosis is excellent.

• Parasites, Hosts and Diseases
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• v.44 no.4 s.140
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• pp.313-320
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• 2006

In an effort to characterize, on the molecular scale, the Acanthamoeba initially isolated from the cornea of an amoebic keratitis patient associated with overnight-wear orthokeratology lens in Korea, we conducted mitochondrial DNA restriction fragment length polymorphism, 18S rDNA sequencing, and drug sensitivity analyses on the isolate (KA/PE1). The patient was treated with polyhexamethylene biguanide, chlorhexidine and oral itraconazole, which resulted in resolution of the patient's ocular inflammation. The majority of the molecular characteristics of the KA/PE1 were determined to be identical, or quite similar, to those of A. castellanii Ma strain, which had been isolated also from amoebic keratitis. The risk of Acanthamoeba keratitis as a potential complication of overnight orthokeratology is briefly discussed.

• Journal of Pharmaceutical Investigation
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• v.24 no.1
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• pp.1-9
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• 1994

In order to study systemic peptide delivery through the ocular route, the stabilities of methionine enkephalin (Met-Enk) and $[D-ala^2]-methionine$ enkephalinamide (YAGFM) in the corneal extracts of rabbits were investigated using reversed phase HPLC. Met-Enk was found to be hydrolyzed most rapidly in the corneal epithelium, but YAGFM was relatively stable. Aminopeptidases appeared to contribute over 60% to the degradation of Met-Enk and the degradation rate of Met-Enk followed the first order kinetics. The half-lives of Met-Enk in the extracts of the corneal epithelium and endothelium were 36 and 673 min, respectively. From the effects of enzyme inhibitors, it was found that the application of the mixture of amastatin, thimerosal and EDTA was very useful for the inhibition of peptide degradation.

• Proceedings of the Korean Society of Applied Pharmacology
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• 1996.04a
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• pp.250-250
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• 1996

Eye irritation, primary skin irritation and skin sensitization tests for Aloewhite were tested in New Zealand White rabbits and Hartley guinea pig. In primary skin irritation test of male New Zealand White rabbits, body weights were not significantly changed and primary Irritation Index(PII) was 0.47, indicating Aloewhite as mildly irritating material, In ocular irritation test, any injury on iris, conjunctival membrane, and cornea in New Zealand White rabbits was not observed. No injuries of the ocular mucous membrane were also recorded. Skin sensitization was tested in guinea Peg after intradermal and epicutaneous induction and graded I with zero % sensitization rate. These results indicate that Aloewhite was not considered to be irritant in test organs of animals.

• The Journal of Korean Society for Radiation Therapy
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• v.9 no.1
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• pp.40-45
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• 1997

When therapeutic irradiation is indicated for the orbital tumors, the greatest concern is the risk of radiation-induced cataract. Conjunctival lymphoma is one of the good examples. We would like to report the procedure of the lens shielding device(L.S.D) and the result of irradiated dose to the lens. L.S.D. consistes of two parts : load alloy to attenuate electron beam, and dental acryl which completely covers the lead alloy to avoid discomfort of cornea from contacting directly with cerrobend and side scattering by cerrobend. And for easy location and removal, side bars were made on each side. Radiation doses were meaured with TLD(TLD 3500 Hawshaw). Markus chamber in a polystyrene phantom. The phantom was irradiated with 9MeV electron beams from Clinac 2100C with $6{\times}6cm$ electron cone. The relative dose at 6mm depth where the lens is located was $4.2\%$ with TLD and $5.1\%$ with Markus chamber clinically when 2600 cGy are irradiated to the eyeball, the mapinary dose to the lens will be 109 cGy or 132 cGy, which will significently reduce the cataract.

• Journal of Korean Ophthalmic Optics Society
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• v.4 no.2
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• pp.51-55
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• 1999

The eye movement of the eyeball's center of a rotation can represent with the rotation matrix $R_x$, $R_y$, $R_z$ due to a coordinate axis rotation transformation of Cartesian coordinate, and describes of an abduction, an adduction, an elevation, a depression, an intorsion, an extorsion in principle rotation six forms of the eye. The eye movement from primary eye position to tertiary eye position could be composed with the rotation matrix combination, and by the primary rotation of six and the secondary rotation of eight, could be represented with the extrocular muscle of six. The position of the cornea vertex point or pupil point due to the eye movement can describe to transform the rotation matrix of the cartesian coordinate to spherical coordinate$(r,{\theta},{\phi})$.