• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.22 no.11
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• pp.905-909
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• 2009

The new Junction Field Effect Transistors (JFETs) with Silicon-germanium (SiGe) layers is investigated. This structure uses SiGe layer to prevent out diffusion of boron in the channel region. In this paper, we report electrical properties of SiGe JFET measured under various design parameters influencing the performance of the device. Simulation results show that out diffusion of boron is reduced by the insertion SiGe layers. Because the SiGe layer acts as a barrier to prevent the spread of boron. This proposed JFET, regardless of changes in fabrication processes, accurate and stable cutoff voltage can be controlled. It is easy to maintain certain electrical characteristics to improve the yield of JFET devices.

• 한국정보디스플레이학회:학술대회논문집
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• 2003.07a
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• pp.978-980
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• 2003

Perylene tetracarboxylic anhydride derivatives have been well-known as an n-type channel material.$^1$ Here, we report perylene-based pyrrolopyrone derivatives as an n-type channel material. 1,8-naphthalene(l) and 1,2-phenylene(2)-based pyrrolopyrone derivatives were synthesized and characterized. Derivatives 1, 2 were soluble only protonic solvents with high acidity such as methane sulfonic acid and trifluoroacetic acid. Thin film transistors were fabricated by vacumn deposition and solution casting and electron mobility of the device were measured.

• Journal of Information Processing Systems
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• v.10 no.2
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• pp.215-222
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• 2014

In this paper, we discuss optical encryption and decryption considering wireless communication channels. In wireless communication systems, the wireless channel causes noise and fading effects of the transmitted information. Optical encryption technique such as double-random-phase encryption (DRPE) is used for encrypting transmitted data. When the encrypted data is transmitted, the information may be lost or distorted because there are a lot of factors such as channel noise, propagation fading, etc. Thus, using digital modulation and maximum likelihood (ML) detection, the noise and fading effects are mitigated, and the encrypted data is estimated well at the receiver. To the best of our knowledge, this is the first report that considers the wireless channel characteristics of the optical encryption technique.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.20 no.8
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• pp.761-769
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• 2009

In this paper, we report on the channel capacity and diversity gain of the vehicle on-glass antenna for FM radio reception. The correlation coefficient and channel capacity were obtained using the simulated 3D radiation pattern of each antenna and the Rayleigh channel model for urban environment. To examine the channel capacity we used two antennas which are a simple straight antenna and L-type antenna. Then we observed the available channel capacity by varying the position of feeds and the shape of the L-type antenna. The sample antenna, which has a maximum feed distance with different polarizations, was built and the receiving performance was measured in the weak FM field area. From the results we confirmed that the distance between the feeds should be placed as far as possible for the high channel capacity. If the distance between the feeds are greater than a certain threshold value than the polarizations of the two antennas are getting more important for determining the channel capacity.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2006.11a
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• pp.87-88
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• 2006

Recently, poly-Si TFT-LCD starts to be mass produced using excimer laser annealing (ELA) poly-Si. The main reason for this is the good quality poly-Si and large area uniformity. We report the influence of channel length and width on poly-Si TFTs performance. Transfer characteristics of p-channel poly-Si thin film transistors fabricated on polycrystalline silicon (poly-Si) thin film transistors (TFTs) with various channel lengths and widths of 2-30 ${\mu}m$ has been investigated. In this paper, we analyzed the data of p-type TFTs. We studied threshold voltage ($V_{TH}$), on/off current ratio ($I_{ON}/I_{OFF}$), saturation current ($I_{DSAT}$), and transconductance ($g_m$) of p-channel poly-Si thin film transistors with various channel lengths and widths.

• The Korean Journal of Physiology and Pharmacology
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• v.21 no.4
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• pp.439-447
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• 2017

Myotonia congenita (MC) is a genetic disease that displays impaired relaxation of skeletal muscle and muscle hypertrophy. This disease is mainly caused by mutations of CLCN1 that encodes human skeletal muscle chloride channel (CLC-1). CLC-1 is a voltage gated chloride channel that activates upon depolarizing potentials and play a major role in stabilization of resting membrane potentials in skeletal muscle. In this study, we report 4 unrelated Korean patients diagnosed with myotonia congenita and their clinical features. Sequence analysis of all coding regions of the patients was performed and mutation, R47W and A298T, was commonly identified. The patients commonly displayed transient muscle weakness and only one patient was diagnosed with autosomal dominant type of myotonia congenita. To investigate the pathological role of the mutation, electrophysiological analysis was also performed in HEK 293 cells transiently expressing homo-or heterodimeric mutant channels. The mutant channels displayed reduced chloride current density and altered channel gating. However, the effect of A298T on channel gating was reduced with the presence of R47W in the same allele. This analysis suggests that impaired CLC-1 channel function can cause myotonia congenita and that R47W has a protective effect on A298T in relation to channel gating. Our results provide clinical features of Korean myotonia congenita patients who have the heterozygous mutation and reveal underlying pathophyological consequences of the mutants by taking electrophysiological approach.

• Clinical and Experimental Pediatrics
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• v.59 no.sup1
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• pp.116-120
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• 2016

Congenital hyperinsulinism (CHI) is a rare condition that can cause irreversible brain damage during the neonatal period owing to the associated hypoglycemia. Hypoglycemia in CHI occurs secondary to the dysregulation of insulin secretion. CHI has been established as a genetic disorder of islet-cell hyperplasia, associated with a mutation of the ABCC8 or KCNJ11 genes, which encode the sulfonylurea receptor 1 and the inward rectifying potassium channel (Kir6.2) subunit of the ATP-sensitive potassium channel, respectively. We report the case of a female newborn infant who presented with repetitive seizures and episodes of apnea after birth, because of hypoglycemia. Investigations revealed hypoglycemia with hyperinsulinemia, but no ketone bodies, and a low level of free fatty acids. High dose glucose infusion, enteral feeding, and medications could not maintain the patient's serum glucose level. Genetic testing revealed a new variation of ABCC8 mutation. Therefore, we report this case of CHI caused by a novel mutation of ABCC8 in a half-Korean newborn infant with diazoxide-unresponsive hyperinsulinemic hypoglycemia.

• Biomedical Science Letters
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• v.21 no.3
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• pp.144-151
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• 2015

Development of hypertension is caused by complex contributions of genetic and environmental factors. In spite of the increased understanding of hypertension, genetic factors that contribute to hypertension largely remain elusive. ANO1 gene encoding a calcium-activated chloride channel has recently been reported to affect spontaneous hypertension in the animal model. In this report, we investigated possible association of the ANO1 gene with hypertension in human with ANO1 variants found in Korean population. Fourteen polymorphisms of ANO1 gene were analyzed to be associated with hypertension. Interestingly, the six polymorphisms that showed statistically significant association were all the male subjects. The highest significant SNP was rs7127129 (OR=1.14, CI: 1.02~1.28, additive P=0.023; OR=1.24, CI: 1.03~1.49, dominant P=0.025), and other five SNPs (rs2509153, rs11235473, rs10751200, rs10898827 and rs10899928) were also statistically associated with hypertension. Consequently, we found that the genetic variants of ANO1 present statistically significant associations with hypertension in human, especially, in male. To the best of our knowledge, this study is the first report describing association of genetic polymorphisms of ANO1 with hypertension in human.

• Journal of Physiology & Pathology in Korean Medicine
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• v.21 no.1
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• pp.303-307
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• 2007

This clinical experience reports the effect of wood and fire acupoints therapy on a hypertensive patient. Wood acupoint indicates Jing point in yin channel or Shu point in yang channel. Fire acupoint is Jing in yin channel or Jing in yang channel among the five acupoints of Jing, Xing, Shu, Jing and He. The patient was treated with indicated acupoints of 7 channels: lung, large intestine, spleen, pericardium, triple warmer, heart and liver, for 5 weeks. In case of necessity, another acupoints were added with wood and fire acupoints. After 5 weeks treatment, the blood pressure improved by 125/80 which is in normal level. This result suggests that wood and fire acupoints therapy is effective in the treatment of hypertension.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.63 no.4
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• pp.546-550
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• 2014

In this research, we report all the elements are placed in the space above the patient table as a transmit coil to give optimized B1+ field for the body object. Through the simulations, we compared upper-and-lower parts combined 8 channel Tx array to upper only 8 channel Tx array and showed the utilities of B1+ shimming in multi-channel Tx body imaging at 3T. Half-cylinder shaped upper array shows weak B1+ field area around back of patient without B1+ shimming. After B1+ shimming, highly induced SAR places occurred in the arm region due to the close distance to the both end elements which were driven by very high RF current to enhance B1+ in back area. The proposed upper and lower combined array provides an enhanced homogeneous B1+ field in large ROI imaging as a result of shimming over the body size phantom. Through this research we proved the usefulness of the proposed insertional upper and lower parts combined transmit array for 3T body imaging.