• 대한전자공학회:학술대회논문집
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• 대한전자공학회 2002년도 ITC-CSCC -3
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• pp.1626-1629
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• 2002

This paper describes novel methods to construct fuzzy inference rules with gradient descent. The present methods have a constructive mechanism of the rule unit that is applicable in two parameters: the central value and the width of the membership function in the antecedent part. The first approach is to create the rule unit at the nearest position from the input space, for the central value of the membership function in the antecedent part. The second is to create the rule unit which has the minimum width, for the width of the membership function in the antecedent part. Experimental results are presented in order to show that the proposed methods are effective in difference on the inference error and the number of learning iterations.

• 대한원격탐사학회:학술대회논문집
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• 대한원격탐사학회 2003년도 Proceedings of ACRS 2003 ISRS
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• pp.750-752
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• 2003

The objective of this investigation is to compare the geometric precision of Rigorous Sensor Model and Rational Function Model for QuickBird images. In rigorous sensor model, we use the on-board data and ground control points to fit an orbit; then, a least squares filtering technique is applied to collocate the orbit. In rational function model, we first use the rational polynomial coefficients provided by the satellite company. Then the systematic bias of the coefficients is compensated by an affine transformation using ground control points. Experimental results indicate that, the RFM provides a good approximation in the position accuracy.

• The Korean Journal of Physiology
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• 제28권1호
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• pp.1-17
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• 1994

• The Korean Journal of Physiology and Pharmacology
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• 제1권3호
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• pp.315-323
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• 1997

Central tryptaminergic system has been shown to play an important role in the regulation of renal function: $5-HT_1(5-hydroxytryptamine_1)$ receptors might seem to mediate the diuresis and natriuresis, whereas the $5-HT_2\;and\;5-HT_3$ receptors mediate the antidiuretic and antinatriuretic effects. This study attempted to delineate the role of central $5-HT_{1A}$ subtype in the regulation of rabbit renal function by observing the renal effects of intracerebrovent-ricularly(icv)-administered PAPP(p-aminorhenylethyl-m-trifluoromethytphenyl piperazine, LY165163), a selective agonist of $5-HT_{1A}$ receptors. PAPP in doses ranging from 40 to $350{\mu}g/kg$ icv induced significantly diuresis, natriuresis, and kaliuresis, along with increased renal perfusion and glomerular filtration. Systemic blood pressure was also increased. Free water reabsorption$(T^cH_2O)$, a measure of ADH(antidiuretic hormone) secretion, was increased also. Intravenous $350{\mu}g/kg$ of PAPP elicited antidiuresis and antinatriuresis together with decreased blood pressure, thus indicating that the effects of icv PAPP were brought about through the central mechanisms, not by direct peripheral effects of the drug on kidney. Ketanserin, a selective $5-HT_2$ antagonist, $40{\mu}g/kg$ icv, did not affect the renal effects of the icv PAPP. Methysergide, a non-selective $5-HT_1$ antagonist, also did not block the renal functional responses by the icv PAPP. NAN-190, a $5-HT_{1A}$ antagonist, also did not antagonized the renal action of the icv PAPP. However the increased free water reabsorption was abolished by both methysergide or ketanserin pretreatment. The increments of blood pressure by icv PAPP was blocked only by NAN-190 pretreatment. These observations suggest that the central $5-HT_{1A}$ receptor might be involved in the central regulation of rabbit renal function by exerting the diuretic and natriuretic influences.

• International Journal of Stem Cells
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• 제15권2호
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• pp.155-163
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• 2022

Background and Objectives: Mesenchymal stem cells (MSCs) have immunomodulatory function and participate in the pathogenesis of many immunoregulation-related diseases, including psoriasis. Previously, we found that MSCs from psoriatic lesions overexpress the proinflammatory microRNA, miR-155 and exhibit a decreased immunosuppressive capacity. But the origin of these aberrant characteristics is still not clear. To investigate whether inflammatory cytokines in serum and peripheral blood mononuclear cells (PBMCs) from psoriatic patients can regulate the expression patterns of immunoregulation-related cytokines and the immunoregulation function of MSCs. Methods and Results: Normal dermal mesenchymal stem cells (nDMSCs) were treated with serum or PBMCs derived from patients with psoriasis or healthy donors. Expression of miR-155 and immunoregulation-related genes in each MSCs were measured using real-time PCR or western-blot. Meanwhile, the immunosuppressive capacity of DMSCs was evaluated by its inhibitory ability on proliferation of activated PBMCs. Compared to control serum, psoriatic serum significantly increased the expression levels of miR-155 (27.19±2.40 vs. 3.51±1.19, p<0.001), while decreased TAB₂ expression (0.28±0.04 vs. 0.72±0.20, p<0.01) in DMSCs. Expression levels of immunoregulation-related genes such as PGE₂, IL-10, and TLR4 were also markedly down-regulated following the psoriatic serum treatment. Those DMSCs treated with healthy serum could inhibit PBMC proliferation, while those psoriatic serum-treated DMSCs could not inhibit PBMC proliferation effectively. Conclusions: Psoriatic serum up-regulate the expression of miR-155, down-regulate the expression of immunoregulation-related genes (PGE₂, IL-10, and TLR4) in DMSCs, and along with the inhibition of the immunosuppressive function of MSCs.

• 한국지역지리학회지
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• 제12권5호
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• pp.571-582
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• 2006

지방행정의 통치 단위인 군현 지역 내에서 한 장소가 중심지로 선정되고 발전하는 것은, 해당 지역의 자연적 조건과 사회적 상황의 결합에 의한 것이다. 이러한 중심지는 사회적 상황 변화에 따라 그 역할이 변화하지만, 역할 변화에도 불구하고 중심지로서의 지리적 관성을 지니게 된다. 본 연구에서는 행정 중심지로서 역할을 수행했던 칠보 지역을 사례로, 중심지의 역할 변화와 지리적 관성 유지의 특성을 살펴보았다. 그 결과는 첫째, 시대에 따라 중심지의 역할이 변화했다. 이 지역은 삼국시대에는 국방 행정 교통의 중심지였으나, 삼국의 통일과 함께 국방 중심지로서의 역할이 사라졌다. 고려시대에 들어서면서 교통축의 변화로 교통 중심지 기능도 상실되었고, 결국 행정 중심지의 기능 상실로 이어졌다. 둘째, 외부 인물과 그 지역 내부 인물의 결합에 의해서 중심성이 유지되었다. 최치원, 정극인, 신잠 등의 외부 인물과 송세림, 정언충, 김약묵, 김관 등의 내부 인물에 의해 행정 중심 기능이 아닌 새로운 유교 문화와 교육의 중심지로서 지리적 관성을 유지했다. 셋째, 중심지의 역할 변화에 따라 미시적으로 지역 내에서 중심지의 입지 이동이 있었다. 시산리의 송산 마을에서 남전 마을 그리고 무성리의 원촌 마을로 중심 장소가 이동되었다.

• Korean Journal of Radiology
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• 제22권12호
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• pp.2052-2061
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• 2021

Objective: The role of preoperative overt hepatic encephalopathy (OHE) in the neurophysiological mechanism of cognitive improvement after liver transplantation (LT) remains elusive. This study aimed to explore changes in sub-regional thalamic functional connectivity (FC) after LT and their relationship with neuropsychological improvement using resting-state functional MRI (rs-fMRI) data in cirrhotic patients with and without a history of OHE. Materials and Methods: A total of 51 cirrhotic patients, divided into the OHE group (n = 21) and no-OHE group (n = 30), and 30 healthy controls were enrolled in this prospective study. Each patient underwent rs-fMRI before and 1 month after LT. Using 16 bilateral thalamic subregions as seeds, we conducted a seed-to-voxel FC analysis to compare the thalamic FC alterations before and after LT between the OHE and no-OHE groups, as well as differences in FC between the two groups of cirrhotic patients and the control group. Correction for multiple comparisons was conducted using the false discovery rate (p < 0.05). Results: We found abnormally increased FC between the thalamic sub-region and prefrontal cortex, as well as an abnormally decreased FC between the bilateral thalamus in both OHE and no-OHE cirrhotic patients before LT, which returned to normal levels after LT. Compared with the no-OHE group, the OHE group exhibited more extensive abnormalities prior to LT, and the increased FC between the right thalamic subregions and right inferior parietal lobe was markedly reduced to normal levels after LT. Conclusion: The renormalization of FC in the cortico-thalamic loop might be a neuro-substrate for the recovery of cognitive function after LT in cirrhotic patients. In addition, hyperconnectivity between thalamic subregions and the inferior parietal lobe might be an important feature of OHE. Changes in FC in the thalamus might be used as potential biomarkers for recovery of cognitive function after LT in cirrhotic patients.

• Kyungpook Mathematical Journal
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• 제49권3호
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• pp.435-450
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• 2009

On page 366 of his lost notebook [15], Ramanujan recorded a cubic continued fraction and several theorems analogous to Rogers-Ramanujan's continued fractions. In this paper, we derive several general formulas for explicit evaluations of Ramanujan's cubic continued fraction, several reciprocity theorems, two formulas connecting V (q) and V ($q^3$) and also establish some explicit evaluations using the values of remarkable product of theta-function.

• Biomolecules & Therapeutics
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• 제28권1호
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• pp.45-57
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• 2020

In the neurovascular unit, the neuronal and vascular systems communicate with each other. O₂ and nutrients, reaching endothelial cells (ECs) through the blood stream, spread into neighboring cells, such as neural stem cells, and neurons. The proper function of neural circuits in adults requires sufficient O₂ and glucose for their metabolic demands through angiogenesis. In a central nervous system (CNS) injury, such as glioma, Parkinson's disease, and Alzheimer's disease, damaged ECs can contribute to tissue hypoxia and to the consequent disruption of neuronal functions and accelerated neurodegeneration. This review discusses the current evidence regarding the contribution of oxygen deprivation to CNS injury, with an emphasis on hypoxia-inducible factor (HIF)-mediated pathways and Notch signaling. Additionally, it focuses on adult neurological functions and angiogenesis, as well as pathological conditions in the CNS. Furthermore, the functional interplay between HIFs and Notch is demonstrated in pathophysiological conditions.

• 한국융합학회논문지
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• 제12권7호
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• pp.1-6
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• 2021

현재, 코로나19등 바이러스 감염이 일상화 되어 있고, 비대면 ICT 서비스를 위한 분야에 무인시스템에 대한 관심이 증가하고 있다. 본 논문에서는 방송기능을 가진 IP PBX를 이용하여 원격으로 중, 소형 점포를 중앙에서 영상과 음성을 통해 성공적으로 관제할 수 있는 기능과 성능을 시험을 통하여 입증하였다. 현재 완전 무인 시스템은 여러 가지 기술적 문제로 신뢰성이 없지만, 본 논문에서 개발한 중앙관제시스템은 영상과 음성을 통해 관제사가 출입과 내부를 모니터링 함으로 직접 소비자를 관제할 수 있어 매우 효율적이고 신뢰를 할 수 있는 시스템이다. 향후에는 A.I 기술을 활용한 완전 무인 원격제어 시스템을 연구할 예정이다.