• Journal of Life Science
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• v.31 no.8
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• pp.710-718
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• 2021

Placenta-derived mesenchymal stem cells (PD-MSCs) are promising candidates for cell-based therapy in regenerative medicine. The migration and homing potential of PD-MSCs to injured sites is a critical property of MSC engraftment. MicroRNAs (miRNAs) have recently been shown to regulate the critical functions of MSCs, such as proliferation, survival, and migration. The objective of the present study was to identify the miRNA and target genes involved in PD-MSCs homing in a bile duct ligation (BDL) rat model. We selected candidate miRNAs targeting genes for PD-MSCs homing based on microarray analysis. PD-MSC engraftment in BDL-injured rat liver was identified by immunofluorescence assay and human-specific Alu gene expression by quantitative real-time polymerase chain reaction (qRT-PCR) one week after transplantation. Compared with migrated naïve PD-MSCs under hypoxic and normoxic conditions (Hyp/Nor), the transplanted group with PD-MSCs (Tx) showed distinct differences in miRNA expressions in BDL-injured rat liver. We also validated the miRNAs and their target genes for PD-MSCs homing. The expressions of integrin α4 (ITGA4) and integrin α5 (ITGA5) target genes for miR-199a-5p and miR-148a-3p were significantly upregulated in the Tx group (p<0.05). In addition, integrin β1 (ITGB1) and integrin β8 (ITGB8) were upregulated by suppressing miR-183-5p and miR-145-5p, respectively. These results demonstrated that PD-MSCs regulate miRNA expression related to the integrin family for their homing effects on the BDL-injured rat liver. The findings further suggest that miRNA-mediated regulation of the integrin family contributes to the therapeutic efficacy of PD-MSCs in the rat hepatic fibrosis model by BDL.

• Journal of Navigation and Port Research
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• v.48 no.3
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• pp.137-145
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• 2024

Recently, there has been an increase in the use of Automatic Identification Systems. Class A AIS is used for ships engaged in international voyages, while Class B AIS is utilized for smaller vessels navigating domestic coastlines. AtoN AIS is used for aids to navigation, AIS is employed for search and rescue aircraft, and AIS-SART is widely used worldwide. Accordingly, in 2022, the Maritime Safety Committee(MSC) of the International Maritime Organization(IMO) revised the performance standards for the satellite emergency positioning radio beacon(EP IRB) to include AIS signals along with 121.5 MHz for aircraft, which has been used as a homing signal. It was recommended to use together as a homing signal, and from July 1, 2022, it was decided that AIS-EP IRB that satisfies the revised performance standards will replace the existing EP IRB. Consequently, starting from July 1, 2022, it was decided that AIS-EPIRB, which meets the revised performance standards, will replace the existing EP IRB. This paper aims to verify the feasibility of implementing AIS-EPIRB, which has not yet been developed domestically. To achieve this, a dedicated chipset for AIS was used to additionally implement frequency generation of 161.975 MHz and 162.025 MHz and GMSK modulation to satisfy the requirements.

• Proceedings of the Korean Operations and Management Science Society Conference
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• 1997.10a
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• pp.138-141
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• 1997

In this study, a simulation model is developed to analyze the effects of routing and scale-economy of transmission facilities on the traffic network topology and investment cost changes in a metropolitan telephone network. Computational experiments showed that the wide deployment of bifurcated routing in a dual-homing configuration reduces significantly the traffic network connectivity and the investment cost. Its enhanced version, when combined with the subscriber network cost model, can be used as a prototype cost proxy model for figuring out the access charges in a multi-operator environment.

• Electronics and Telecommunications Trends
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• v.18 no.3 s.81
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• pp.11-20
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• 2003

최근 SCTP(Stream Control Transmission Protocol)는 TCP/UDP 이후의 차세대 수송계층 프로토콜로서 주목 받고 있다. SCTP는 기존 TCP 및 UDP의 문제점을 극복하도록 설계되었으며 특히 multi-streaming 및 multi-homing 특성을 제공한다. 본 고에서는 SCTP 프로토콜의 기본 특징에 대하여 알아보고, 현재 논의중인 확장작업의 주요 골자를 살펴본다.

• International Journal of Precision Engineering and Manufacturing
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• v.3 no.4
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• pp.24-30
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• 2002

In grinding operations, one of the most important problems is to increase efficiency of process. In order to achieve this purpose, it is necessary to administer the tool lift of grinding wheel and to optimize grinding conditions. Frequently dressing result in lowering the process efficiency remarkably and makes production cost high. On the other hand, grinding with a worn wheel causes the workpiece surface roughness to increase and often results in the occurrence of such troubles as chatter vibration and homing.

• Proceedings of the IEEK Conference
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• 2008.06a
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• pp.699-700
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• 2008

In this paper, we implement Mobile AP system, which has Multihoming function providing vertical handover between WiBro and HSDPA networks. We monitor packet drop in networks during binding updates(BU) and acknowledgement(BA) and analyze handover latency. We propose methodology to reduce handover latency and describe the further development direction of Mobile AP system.

• Bulletin of Food Technology
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• v.23 no.4
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• pp.535-543
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• 2010

장관은 우리 몸에서 가장 넓은 표면적을 가지고 있으며, 외부로부터 침입하는 이물에 대항하여 면역세포의 배치가 필수적이다. 항원과 만난 적이 없는 naive lymphocyte는 임파절 등 2차 임파기관의 수지세포(dendritic cell)가 임파구에 항원을 제시할 때 레티노인산(retinoic acid)을 생산하여 제공함으로써, 소장 조직에 특이적으로 임파구가 호밍(homing)하는 능력을 부여한다. 한편, 장에 있어서는 식품항원에 대한 면역반응을 억제할 필요가 있는데, RA는 T세포의 기능분화를 억제하여 면역관용의 성립에도 관여함이 밝혀졌다.

• Proceedings of the Korean Institute of Communication Sciences Conference
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• 2004.11a
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• pp.461-461
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• 2004

• Proceedings of the Korean Institute of Communication Sciences Conference
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• 2004.11a
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• pp.393-393
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• 2004

• Journal of the Korean Society for Industrial and Applied Mathematics
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• v.19 no.3
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• pp.305-325
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• 2015

In this paper, missile homing guidance laws to control the impact angle and time are proposed based on the polynomial function. To derive the guidance commands, we first assume that the acceleration command profile can be represented as a polynomial function with unknown coefficients. After that, the unknown coefficients are determined to achieve the given terminal constrains. Using the determined coefficients, we can finally obtain the state feedback guidance command. The suggested approach to design the guidance laws is simple and provides the more generalized optimal solutions of the impact angle and time control guidance.