• 대한전자공학회논문지SP
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• 제42권6호
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• pp.177-186
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• 2005

이 논문에서는 계산 복잡성이 단순화된 비선형 추정기를 소개하고, 이를 적용한 Bussgang 블라인드 등화 알고리즘을 제안한다. 제안한 알고리즘은 베이즈 추정기가 눈 모형이 닫힌 등화 초기에는 시그모이드 추정기로 잘 근사화되며, 눈 모형이 열린 조건에서는 임계 추정기에 근사화되는 사실을 이용하였다. 제안 방법에서는 매 갱신 마다 채널 왜곡의 정도에 따라 시그모이드 추정기와 임계 추정기를 선택적으로 적용하고, 특히 시그모이드 추정기에 축소 신호점을 도입함으로써 고차 QAM 신호의 블라인드 등화에 적용 시 계산 복잡성을 극히 단순화하는 동시에 블라인드 수렴 특성과 정상상태 성능을 개선할 수 있음을 보인다.

• BMB Reports
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• 제50권2호
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• pp.60-70
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• 2017

Glaucoma is characterized by a slow and progressive degeneration of the optic nerve, including retinal ganglion cell (RGC) axons in the optic nerve head (ONH), leading to visual impairment. Despite its high prevalence, the biological basis of glaucoma pathogenesis still is not yet fully understood, and the factors contributing to its progression are currently not well characterized. Intraocular pressure (IOP) is the only modifiable risk factor, and reduction of IOP is the standard treatment for glaucoma. However, lowering IOP itself is not always effective for preserving visual function in patients with primary open-angle glaucoma. The second messenger cyclic adenosine 3',5'-monophosphate (cAMP) regulates numerous biological processes in the central nervous system including the retina and the optic nerve. Although recent studies revealed that cAMP generated by adenylyl cyclases (ACs) is important in regulating aqueous humor dynamics in ocular tissues, such as the ciliary body and trabecular meshwork, as well as cell death and growth in the retina and optic nerve, the functional role and significance of cAMP in glaucoma remain to be elucidated. In this review, we will discuss the functional role of cAMP in aqueous humor dynamics and IOP regulation, and review the current medications, which are related to the cAMP signaling pathway, for glaucoma treatment. Also, we will further focus on cAMP signaling in RGC growth and regeneration by soluble AC as well as ONH astrocytes by transmembrane ACs to understand its potential role in the pathogenesis of glaucoma neurodegeneration.

• 대한건축학회논문집:계획계
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• 제34권6호
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• pp.23-30
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• 2018

Gordon Cullen, who tried to understand urban landscapes in terms of visual attention, introduced a concept called 'Space and Infinity' in his book 'Townscape'. According to him, urban images like infinity spreading across the sky are more effectively created when we happen to see an open space while walking along a ground-level street than when we look at the sky. This study aims to quantitatively examine if urban observers pay more attention to spaces like pilotis on the bottom of a building. Thus, this study collected observers on actual urban landscape images and partially-edited images and conducted an experiment by adopting Eye-movement Tracking to find out if they actually pay more visual attention to a space like pilotis. This study selected a total of 50 people as research subjects and divided them into two groups. Image 1 was shown to one group, and Image 2 with the pilotis space edited was shown to the other group. As an experiment to find objective evidences on Gordon Cullen's 'Space and Infinity', this study analyzed difference between Image 1 and Image 2, and it was found that the domain of pilotis showed a value five times higher than the average visual attention since it attracted much visual attention although it was very small in area. That is, it has objectively clarified that people get most fascinated with a place with infinite images in the background like a pilotis space out of all the urban landscapes as Gordon Cullen's theory. In addition, the differences in visual concentration of pilotis space by sex, by subject was examined, and there was no significant difference in visual concentration of pilotis space by gender. As a result of examining the difference of visual concentration by classifying the subjects into architectural related major, the major group showed higher frequency of viewing than the non - major group.

• 대한물리의학회지
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• 제16권4호
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• pp.23-31
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• 2021

PURPOSE: This study compared the effect of training ankle joint and hip joint thera-band exercise on balance. METHODS: The participants were divided into two groups of 11 each. Group A performed hip exercise after ankle exercise, and Group B performed ankle exercise after hip exercise. Using a green thera-band, the dorsiflexion and plantarflexion and hip flexion and hip extension were exercised repeatedly for 15 seconds three times with a five-second rest between each set. After the exercise and measurement of one area were complete, the exercise and measurement of the other area were performed at one-day intervals. The balance ability was assessed using a Tetrax and Y-balance test and repeated three times; the best values were taken. RESULTS: In the stability index (ST) of the static balance, the hip joint exercise group (HTG) during the follow-up of normal eye open (NO) revealed notable improvement over the ankle joint exercise group (ATG), and in the follow-up of the normal eye closed (NC), the ATG showed significant improvement over the HTG. In the pillow with eye closed (PC) follow-up, the ATG showed significant improvements over the HTG. At the left (Lt) and Y-balance test (YBT), the ATG showed significant improvements in the follow-up over the HTG (p <.05). CONCLUSION: In static balance, the ATG showed significant improvement in the follow-up of NC and PC over the HTG. In the dynamic balance, the Lt. dynamic balance on the non-dominant side in the ATG showed significant improvement in the follow-up over the HTG.

• 한국의사학회지
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• 제35권1호
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• pp.135-147
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• 2022

Sin Dae-woo was a scholar representing the Ganghwa School in the late Joseon Dynasty. He was Jeong Je-du's grandson-in-law and also in charge of organizing Jeong Je-du's collection of writings. His three sons had a particularly close relationship with their father, so even when they published a collection of writings after his father's death, the names of the three were combined and marked as Jin-jak-shin. The records they left include Seokcheon Il-seung, who described the history of the family along with the collection of writings, Seongdo Il-rok, a diary of the time of Seongcheon Busa, and many letters exchanged over time. These records draw attention as they contain records of medical life, such as eye diseases that the family suffered, infectious diseases that caused many casualties, and Yakro (distilled herbal essence) that showed records of being used for treatment at the time. In this paper: 1) We examine the medicines, prescriptions, acupuncture, and medication used to treat eye diseases. 2) We carefully examine the epidemic, the responses of the parties to it, and the attitudes of those who stood at the boundary between death and life. 3) We look for clues to the use of Western-origin drugs called Yakro. Intellectuals of the time looked deeper into Lee Kyugyung's book and Seo Yu-gu's book on how they were reflected in Joseon's medical life. In conclusion, in the 18th and 9th centuries, we see that the influential families of the Ganghwa school freely brought in famous acupuncturists, used prescriptions that were included in medical books or not, and used Yakro from western origin that were not traditional methods of Joseon. Thus, we reveal that doctors of the Joseon had the capacity to pursue their medical life more actively and had open-minded exchanges than our existing perceptions.

• 한국안광학회지
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• 제17권4호
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• pp.403-410
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• 2012

목적: 정시와 안경 및 콘택트렌즈 착용자의 조절반응량을 비교하고, 각 그룹내에서 굴절이상도와 조절래그의 상관성을 확인하고자 하였다. 방법: 안질환이 없고 굴절이상이 완전 교정된 72명(144안)을 대상으로 폐쇄형 자동굴절검사기로 측정한 굴절이상도를 사용하여 정시, 안경착용자 및 콘택트렌즈 착용자로 분류하였다. 이후 우세안, 나안시력 및 교정시력을 측정하고, 개방형 자동굴절검사기를 이용하여 단안 및 양안으로 원/근거리(5 m/33 cm)를 주시할 때의 굴절이상도를 측정하여 조절래그를 산출하였다. 결과: 좌우안 및 우세안/비우세안의 조절래그는 단안/양안주시 모두 통계적으로 유의한 차이가 없었으며, 단안주시의 조절래그가 양안주시보다 더 크게 검출되었다. 또한 남녀간의 조절래그는 단안주시는 남자가 컸지만 양안주시는 유의한 차이가 없었다. 근시도와 조절래그는 단안/양안주시 모두 근시안이 정시안에 비해 더 컸지만, 안경착용자와 콘택트렌즈 착용자의 조절래그는 단안/양안주시 모두 유의한 차이는 없었다. 전체 대상자의 굴절이상도와 조절래그 상관성은 단안/양안주시 모두 굴절이상도가 클수록 조절래그가 컸으며, 정시안과 콘택트렌즈 착용자는 단안/양안주시 모두 유의한 상관성이 있었으나 안경착용자는 단안/양안주시 모두 유의한 상관성이 없었다. 결론: 정시안과 근시안의 조절래그는 유의한 차이가 있고, 근시안 중 안경착용자와 콘택트렌즈 착용자의 조절래그는 유의한 차이가 없었다. 정시안과 콘택트렌즈 착용자의 굴절이상도는 조절반응량과 상관성을 보였다.

• 대한물리의학회지
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• 제18권4호
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• pp.121-131
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• 2023

PURPOSE: The purpose of this study was to evaluate the effects of ice and hot packs on proprioception, balance, and muscle strength in knee extensor muscle fatigue. METHODS: A total of 31 male and female students in their twenties from a university in A, Chungnam, Korea, were selected as participants. Three experiments were conducted to assess static balance, dynamic balance, proprioception, and muscle strength before and after induction of muscle fatigue, and following intervention. RESULTS: In the case of stability typical (ST), a significant difference was observed in pillow with eye open (PO) when a Hot pack was applied (p < .05). The weight distribution index (WDI), showed significant differences in normal eye open (NO) and Normal eye closed (NC) tests when ice packs and hot packs were applied (p < .05). In the dynamic balance assessment using Y-balance, significant differences were observed in all values except for pre- and post-intervention in the medial and lateral directions (p < .05). The recovery of proprioceptive sensation showed a significant difference when ice packs were applied (p < .05). In muscle strength, significant differences were observed in all comparisons between measurement time points (p < .05). CONCLUSION: Rest was most effective for static balance, and cold and warm compresses were most effective in recovering dynamic balance. For proprioception, cold compresses were most effective. Muscle strength had a positive effect on recovery in all three intervention methods. These results show that cold and warm compresses can be useful in the recovery of various functions related to muscle fatigue.

• Advances in robotics research
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• 제2권2호
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• pp.113-127
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• 2018

Robotics and automation are rapidly growing in the industries replacing human labor. The idea of robots replacing humans is positively influencing the business thereby increasing its scope of research. This paper discusses the development of an experimental platform controlled by a robotic arm through Robot Operating System (ROS). ROS is an open source platform over an existing operating system providing various types of robots with advanced capabilities from an operating system to low-level control. We aim in this work to control a 7-DOF manipulator arm (Robai Cyton Gamma 300) equipped with an external vision camera system through ROS and demonstrate the task of balancing a ball on a plate-type end effector. In order to perform feedback control of the balancing task, the ball is designed to be tracked using a camera (Sony PlayStation Eye) through a tracking algorithm written in C++ using OpenCV libraries. The joint actuators of the robot are servo motors (Dynamixel) and these motors are directly controlled through a low-level control algorithm. To simplify the control, the system is modeled such that the plate has two-axis linearized motion. The developed system along with the proposed approaches could be used for more complicated tasks requiring more number of joint control as well as for a testbed for students to learn ROS with control theories in robotics.

• 대한물리치료과학회지
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• 제17권1_2호
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• pp.33-39
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• 2010

Purpose: The purpose of this study was to analyze the effects of a balance training program using the TARGET Balance Trainer(TBT), which utilizes a visual target, on the balancing ability of normal, healthy individuals. Methods: Twelve healthy female students with an average of 20.7 years(SD=0.25), were participated in this study. They were randomly divided into two groups(6 subjects in each group); experimental group, control group. The experimental group underwent a 3-week training program using the TBT, while the control group trained using only a dynamic air cushion(DAC). Results: Compared to those who trained using only the DAC, participants who trained with the TBT had a smaller difference between the weights distributed(N) to their left and right foot while normal standing with their eyes open. The TBT group also showed a smaller discrepancy between the weights distributed(N) to their left and right sides while standing on one leg with their eyes open, and also with their eyes closed by eye band. Conclusions: TBT is effective to reduce the degree of weight shifting between left and right side in each group. This study is expected to provide a model for future clinical studies.

• 한국정보통신학회:학술대회논문집
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• 한국정보통신학회 2018년도 춘계학술대회
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• pp.182-183
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• 2018

현 시대의 대부분의 사진 혹은 영상에는 사람 눈으로 일일이 다 인식할 수 없을 만큼의 다양한 색을 가진 픽셀들이 분포한다. 특정 목적을 위하여 목표치의 색깔과 비슷한 색깔의 영역을 찾기 위해서는 사람의 눈을 이용한 수동적인 조사가 아닌 픽셀기반의 영상처리가 불가피하다. 본 논문에서는 영상 내에서 원하는 색 혹은 찾고자 하는 영역과 같은 색의 픽셀들은 모두 검출해내고자 한다. 또 더 나아가 찾고자 하는 색깔과 비슷한 색의 픽셀들도 오차 범위 내에서 찾아내고자 한다.