• Annals of Clinical Neurophysiology
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• v.24 no.2
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• pp.59-62
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• 2022

Chronic inflammatory demyelinating polyneuropathy (CIDP) is a chronic recurrent acquired immune-mediated disease of the peripheral nerves that presents with progressive sensory and motor deficits in all four limbs. Cranial nerve involvement is not as common as in Guillain-Barre syndrome, and central nervous system involvement including optic neuritis has rarely been reported in patients with CIDP. We recently experienced a case with classic CIDP involving bilateral facial and trigeminal nerves, right lower cranial nerves, and the right optic nerve.

• Journal of Sensor Science and Technology
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• v.31 no.4
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• pp.194-213
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• 2022

This study comprehensively reviewed four types of integrated-optic electric-field sensors based on titanium diffused lithium-niobate waveguides: symmetric and asymmetric Mach-Zehnder interferometers, 1×2 directional couplers, and Y-fed balanced-bridge Mach-Zehnder interferometers. First, we briefly explain the crystal properties and electro-optic effect of lithium niobate and the waveguide fabrication process. We theoretically analyzed the key parameters and operating principles of each sensor and antennas. We also describe and compare the design, simulation, implementation, and performance tests: dc and ac characteristics, frequency response, dynamic range, and sensitivity. The experimental results revealed that the sensitivity of the sensor based on the Y-fed balanced bridge Mach-Zehnder interferometer (YBB-MZI) was higher than that of the other types of sensors.

• Journal of Yeungnam Medical Science
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• v.40 no.4
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• pp.419-422
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• 2023

Septo-optic dysplasia (SOD) is a rare congenital anomaly that is clinically defined by developmental delay and characteristic brain magnetic resonance imaging findings, including optic nerve hypoplasia, pituitary hormone abnormalities, and midline brain defects. The occurrence of SOD is generally sporadic; however, it can be inherited rarely. Although an association with HESX1, SOX2, and SOX3 mutations has been identified, the detailed etiology is multifactorial and unclear. Here, we present the case of a 7-year-old girl who was clinically diagnosed with SOD and 15q13.3 duplication. Patients with duplication at chromosome 15q13.3 were reported to be diagnosed with autism spectrum disorder, epilepsy, and schizophrenia in previous studies. The relationship between SOD and the microduplication of 15q13.3 has not yet been explored. In this study, we suggest that there may be an association between chromosome 15q13.3 microduplication and SOD.

• Current Optics and Photonics
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• v.8 no.3
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• pp.225-229
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• 2024

This paper introduces a rapid measurement technique for the stress-optic coefficient, using terahertz time-domain spectroscopy. First we propose a design combining a four-point bending device with a scanning stage to streamline the loading process. Then we detail the measurement principle and outline the signal-processing algorithm. The experiments are carried out on Al₂O₃, a representative ceramic material. The experimental data reveal that the refractive index of Al₂O₃ exhibits a linear decrease with increasing stress. This work supplies an efficient method for stress measurement rooted in the stress-optic effect.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2012.05a
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• pp.707-708
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• 2012

• Proceedings of the Optical Society of Korea Conference
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• 2009.10a
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• pp.20-21
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• 2009

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2009.10a
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• pp.415-416
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• 2009

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2007.06a
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• pp.141-142
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• 2007

• Journal of the Korean Ceramic Society
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• v.52 no.4
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• pp.229-233
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• 2015

Currently, the majority of commercial white LEDs are phosphor converted LEDs made of a blue-emitting chip and YAG yellow phosphor dispersed in organic silicone. However, silicone in high-power devices results in long-term performance problems such as reacting with water, color transition, and shrinkage by heat. Additionally, yellow phosphor is not applicable to warm white LEDs that require a low CCT and high CRI. To solve these problems, mixing of green phosphor, red phosphor and glass, which are stable in high temperatures, is common a production method for high-power warm white LEDs. In this study, we fabricated conversion lenses with LUAG green phosphor, SCASN red phosphor and low-softening point glass for high-power warm white LEDs. Conversion lenses can be well controlled through the phosphor content and heat treatment temperature. Therefore, when the green phosphor content was increased, the CRI and luminance efficiency gradually intensified. Moreover, using high heat treatment temperatures, the fabricated conversion lenses had a high CRI and low luminance efficiency. Thus, the fabricated conversion lenses with green and red phosphor below 90 wt% and 10 wt% with a sintering temperature of $500^{\circ}C$ had the best optical properties. The measured values for the CCT, CRI and luminance efficiency were 3200 K, 80, and 85 lm/w.

• Journal of the Korean Society for Nondestructive Testing
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• v.32 no.2
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• pp.177-184
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• 2012

An optical defect detection method using ESPI(electronic speckle pattern interferometry) is proposed. ESPI is widely used as a non-contact measurement system which show deformation and phase map in real time. ESPI can be divided as the in-plane, out-of-plane and shearography by operation principle and target object and also divided with bulk type and optic fiber type by the optic configurations. This paper is focused on optic fiber type out-of-plane ESPI, which has the following advantages: (1) low cost; (2) reduction of the unreliable factors generated by separated optic components; (3) simplification of the optic configuration; (4) great reduction of volume; (5) flexibility, to be easily designed into different structures to adapt to inaccessible environments such as pipeline cavity and so on.