• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2008.06a
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• pp.166-167
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• 2008

현재 Passive component 중의 하나인 트랜스포머의 소형화가 큰 이슈로 대두되고 있다. 본 논문에서는 기판의 와전류 효과의 영향을 줄이기 위해 LTCC기판을 이용하여 트랜스포머를 설계하고, 1:1 및 1:n의 권선 수를 갖는 두 코일의 인덕턴스 및 상호 인덕턴스를 시뮬레이션 하였다. 트랜스포머의 최대 크기는 2.55mm $\times$ 1.1 mm 이고 선폭은 50um 선간 간격은 50um이고, 기둥의 높이는 40um이다. MEMS 기술을 사용하여 기판 커플링과 저항손을 줄임으로서 8.5GHz 에서 0.33dB의 낮은 삽입 손실을 나타냈다.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2009.06a
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• pp.123-124
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• 2009

현재 전자기기의 소형화 추세에 맞물려 수동 소자중의 하나인 트랜스포머의 소형화가 큰 이슈가 되고 있다. 본 논문에서는 실리콘 웨이퍼 위에 트랜스포머와의 절연층을 삽입 하여 기판의 에디 커런트로 오는 멤돌이 손실의 영향을 줄이고 중간 코어를 투자율이 높은 퍼멀로이로 설계하여 1차 코일과 2차 코일의 턴수의 비를 기준으로 1:1 인 트랜스포머 (3/3, 5/5, 7/7)의 인덕턴스 및 상호 인덕턴스를 시뮬레이션 하였다. 트랜스포머의 최대 크기는 $1mm\;{\times}\;1.95mm$이고 선폭과 선간 간격, post의 높이는 각각 50um 이다. 이때 삽입 손실은 10GHz에서 0.12dB의 낮은 손실 값을 나타내었다.

• IEIE Transactions on Smart Processing and Computing
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• v.4 no.3
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• pp.133-140
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• 2015

Neural stimulating implantable medical devices (IMDs) have been widely used to treat neurological diseases or interface with sensory feedback for amputees or patients suffering from severe paralysis. More recent IMDs, such as retinal implants or brain-computer interfaces, demand higher performance to enable sophisticated therapies, while consuming power at higher orders of magnitude to handle more functions on a larger scale at higher rates, which limits the ability to supply the IMDs with primary batteries. Inductive power transmission across the skin is a viable solution to power up an IMD, while it demands high power efficiencies at every power delivery stage for safe and effective stimulation without increasing the surrounding tissue's temperature. This paper reviews various wireless neural stimulating systems and their power management techniques to maximize IMD power efficiency. We also explore both wireless electrical and optical stimulation mechanisms and their power requirements in implantable neural interface applications.

• Toxicological Research
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• v.26 no.1
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• pp.61-66
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• 2010

Retinoids have many beneficial effects on dermatological applications. But, retinoids cause skin irritation. In this study, the safety of retinoids was clarified via both primary skin irritation test in rabbits and sensitization study using an integrated model for the differentiation of chemical-induced allergic and irritant skin reaction (IMDS), an alternative method to sensitization test. The effects of retinoids on the change of ultraviolet A (UVA)-induced matrix metalloproteinase-1 (MMP-1) in human skin fibroblasts and the modulation of type-1 pN collagen synthesis in hairless mice were examined to clarify the anti-wrinkle effects. Alltrans retinol (t-ROL) and its derivative, all-trans retinoic acid (t-RA), showed mild skin irritation but did not induce the sensitization. t-ROL and t-RA exerted anti-wrinkle effects by inhibiting the UVA-induced MMP-1 in human skin fibroblasts and increasing the type-1 pN collagen synthesis in hairless mice. These findings suggest that retinoids do not induce the allergy, and show anti-wrinkle effects by decreasing MMP-1 activation and increasing collagen synthesis.

• Journal of The Korean Society of Inherited Metabolic disease
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• v.23 no.1
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• pp.12-16
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• 2023

Patients with inborn metabolic disorder (IMD) show multisystemic manifestations. Heterogenous renal manifestations can develop in IMD patients as well. In this review, the major renal manifestations of IMD and their representative IMDs are described. The major renal manifestations include Fanconi syndrome, renal tubular acidosis, nephrolithiasis, renal cysts and glomerulopathy, and diverse types of IMDs such as carbohydrate metabolism disorders, lysosomal disorders, organic acidemias, mitochondrial disorders, purine and pyrimidine disorders present renal manifestations. Therefore, general and regular renal function evaluation is recommended in addition to specific investigation according to IMD phenotypes.

• Proceedings of the Materials Research Society of Korea Conference
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• 1996.05a
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• pp.76-76
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• 1996

• Proceedings of the Korean Society of Toxicology Conference
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• 2005.05a
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• pp.141-141
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• 2005

• Journal of The Korean Society of Inherited Metabolic disease
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• v.22 no.2
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• pp.37-45
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• 2022

Inherited metabolic disorders (IMD) are a large group of rare disorders affecting normal biochemical pathways. The ophthalmic involvement can be very varied affecting any part of the eye, including abnormalities of cornea, lens dislocation and cataracts, retina and the optic nerve, and extraocular muscles. Eye disorders can be initial symptoms of some IMD and can be clue for diagnosis of IMD. However, eye disorders can evolve later in the natural history of an already diagnosed metabolic disorder. Awareness of IMDs is important to facilitate early diagnosis and in some cases instigate early treatment if a patient presents with eye involvement suggestive of a metabolic disorder. Ophthalmological interventions are also an important component of the multisystem holistic approach to treating patients with metabolic disorders.

• Journal of Sensor Science and Technology
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• v.32 no.4
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• pp.213-218
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• 2023

Triboelectric nanogenerators (TENGs) have emerged as a highly promising energy harvesting technology capable of harnessing mechanical energy from various environmental vibrations. Their versatility in material selection and efficient conversion of mechanical energy into electric energy make them particularly attractive. TENGs can serve as a valuable technology for self-powered sensor operation in preparation for the IoT era. Additionally, they demonstrate potential for diverse applications, including energy sources for implanted medical devices (IMDs), neural therapy, and wound healing. In this review, we summarize the potential use of this universally applicable triboelectric energy harvesting technology in the disinfection and blocking of pathogens. By integrating triboelectric energy harvesting technology into human clothing, masks, and other accessories, we propose the possibility of blocking pathogens, along with technologies for removing airborne or waterborne infectious agents. Through this, we suggest that triboelectric energy harvesting technology could be an efficient alternative to existing pathogen removal technologies in the future.

• Journal of electromagnetic engineering and science
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• v.10 no.2
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• pp.73-77
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• 2010

This paper proposes a novel memory effect measurement technique in RF power amplifiers(PAs) using a two-tone intermodulation distortion(IMD) signal with a very simple and intuitive algorithm. Based on the proposed predistortive tone cancellation technique, the proposed measurement method is capable of measuring the relative phase and magnitude of the third-order and fifth-order IMDs, as well as the fundamental signal. The measured relative phase between the higher and lower IMD signal for specific tone spacing can be interpreted as the group delay(GD) information of the IMD signal concerned. From the group delay analysis, we can conclude that an adaptive control of GD as well as the magnitude and phase is a key function in increasing the linearization bandwidth and the dynamic range in a predistortion(PD) technique.