• Journal of Korean Society for Quality Management
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• v.34 no.1
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• pp.34-39
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• 2006

This paper applies approximation of the renewal function for Hjorth model and Dhillon model which show the trend change in its aging properties. We obtain the renewal function for Hjorth model and Dhillon model by a numerical solution of an approximate integral. We observe the influence of each parameter in these models. The results of the computation are described and their corresponding graphs are provided.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.57 no.5
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• pp.735-740
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• 2008

Recently, the research of PM (Preventive Maintenance) method on the RCM(Reliability-Centered Maintenance) of the system equipment is being actively advanced for a few years. For the most of the current power equipment maintenance, the state of the equipment after maintenance is assumed to be becoming 'as good as new ones' state. However, the state of the power equipment is maintained like the states of the between 'as good as new ones' and 'as bad as old ones' by imperfect maintenance that implies the life decrease of the equipment by frequent breakdown, the error of maintenance process, and so on. So, the Maintenance method considering the real case has to reflect Imperfect maintenance than perfect maintenance. This paper suggests the Preventive Maintenance method by using Quasi - Renewal Theory for the gas turbine equipment as deliberating the imperfect maintenance for the real cases.

• Journal of the Korea Institute of Military Science and Technology
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• v.9 no.2 s.25
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• pp.51-59
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• 2006

The purpose of this paper is to present reliability analysis procedures for repairable systems and apply the procedures for assessing the reliabilities of two subsystems of a specific group of military equipment based on field failure data. The mean cumulative function, M(t), the average repair rate, ARR(t), and analytic test methods are used to determine whether a failure process follows a renewal or non-renewal process. For subsystem A, the failure process turns out to follow a homogeneous Poisson process, and subsequently, its mean time between failures, availability, and the necessary number of spares are estimated. For subsystem B, the corresponding M(t) plot shows an increasing trend, indicating that its failure process follows a non-renewal process. Therefore, its M(t) is modeled as a power function of t, and a preventive maintenance policy is proposed based on the annual mean repair cost.

• Asian Journal of Turfgrass Science
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• v.10 no.1
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• pp.21-29
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• 1996

The mathematical expression in the forest and grassland soils to express the general concepts involved in such terms "a soil erosion and soil renewal. " The net addition rate in the forest and grassland soils are represented by an equation of $(S_{rb}-S_{ra})-(S_{eb}-S_{ea})={\int}_a^bR(m, cl, re, b, t )dt-{\int}E(w, r, cl, re, ch, b, t)dt{\gtreqqless}0$ where $S_r$, is renewal soil, $S_e$ is soil erosion, and variable factors are m =parent material of soil, cl=climate, re=relief or topography, ch=soil characteristics, r=rain or water, w=wind, b=biota, and t = time.

• International Journal of High-Rise Buildings
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• v.10 no.1
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• pp.17-28
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• 2021

In Harbin, a network of underground commercial spaces has been developed to occupy spaces that were originally created as civil defense shelters. With the gradual extension of the local metro rail system, the existing underground commercial space is no longer an isolated regional development, but a space that represents "three-dimensional city" and coordinated development taking place in many Chinese cities. Based on the analysis of the unique development process taken in underground space of Harbin, this paper summarizes three characteristics of its early model of "fragmented development" of underground space. By conducting a comprehensive field research and survey, the researchers analyzed 472 questionnaires related to the development trend, and proposed multi-level synergistic elements for the renewal and development of underground commercial space. The paper concludes by discussing the trend of "three-dimensional and collaborative development," suitable for the development needs of the new era, and the corresponding development strategies for the renewal of underground space.

• Journal of Korean Neurosurgical Society
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• v.64 no.3
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• pp.367-373
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• 2021

Secondary neurulation (SN) is a critical process to form the neural tube in the posterior region of the body including the tail. SN is distinct from the anteriorly occurring primary neurulation (PN); whereas the PN proceeds by folding an epithelial neural plate, SN precursors arise from a specified epiblast by epithelial-to-mesenchymal transition (EMT), and undergo self-renewal in the tail bud. They finally differentiate into the neural tube through mesenchymal-to-epithelial transition (MET). We here overview recent progresses in the studies of SN with a particular focus on the regulation of cell lineage, self-renewal, and EMT/MET. Cellular mechanisms underlying SN help to understand the functional diversity of the tail in vertebrates.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2021.11a
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• pp.254-255
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• 2021

The urban renewal type redevelopment project is a project to improve the urban environment for the recovery of urban functions and revitalization of commercial districts in commercial and industrial areas. Urban regeneration projects are not progressing smoothly. The urban renewal type is not so for landowners, who require a high level of professional knowledge and experience to carry out smooth projects. In addition, the core part of business conflicts can be seen as the problem of management and disposal methods. Therefore, as landowners, etc. become the actual subjects, the public will take charge of project execution, but all development gains and losses will be attributed to the owner of the land, etc.

• The KIPS Transactions:PartC
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• v.11C no.2
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• pp.149-156
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• 2004

Broadcast encryption schemes are applied to transmit digital informations of multimedia, software, Pay-TV etc. in public network. Important thing is that only user who is permitted before only must be able to get digital information in broadcast encryption schemes. If broadcast message transfers, users who authority is get digital information to use private key given in the advance by oneself. Thus, user acquires message or session key to use key that broadcaster transmits, broadcaster need process that generation and distribution key in these process. Also, user secession new when join efficient key renewal need. In this paper, introduce about efficient key generation and distribution, key renewal method. Take advantage of two technique of proposal system. One is method that server creates key forecasting user without user's agreement, and another is method that server and user agree each other and create key Advantage of two proposal system because uses a secret key broadcast message decryption do can and renewal is available effectively using one information whatever key renewal later.

• Horticultural Science & Technology
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• v.32 no.4
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• pp.463-472
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• 2014

Ion imbalance in recycled nutrient solutions is caused by selective ion uptake of plants, which occurs at different rates in different growth stages. The objectives of this study were to investigate the ion balances in both recycled nutrient solutions and rockwool media using different renewal patterns for the nutrient solutions, and to analyze the subsequent effects on uptake of water and nutrients. Over 12 weeks of paprika cultivation, two different renewal patterns (week units) of 6-4-2 and 8-2-2 weeks were compared with a constant renewal pattern of 4-4-4 weeks (control). The nutrient solution in the reservoir tank was constantly maintained at EC $2.5dS{\cdot}m^{-1}$ and pH 5.5-6.5. The changes in the ion balance with the 4-4-4 week pattern were smaller than those with the other treatments. In the early growth stage, however, the ion balances similarly changed among all treatments. Greater changes were subsequently observed for the 6-4-2 week pattern. Although fruit yield and shoot fresh weight of paprika were the lowest with 6-4-2 renewal pattern, no significant differences were observed. Our results indicate that renewal intervals can be extended in consideration of growth stage for more efficient and practical operations in closed soilless cultures.

• Journal of Ginseng Research
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• v.43 no.3
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• pp.421-430
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• 2019

Background: The ginsenoside Rg3, one of active components of red ginseng, has chemopreventive and anticancer potential. Cancer stem cells retain self-renewal properties which account for cancer recurrence and resistance to anticancer therapy. In our present study, we investigated whether the standardized Korean Red Ginseng extract (RGE) and Rg3 could modulate the manifestation of breast cancer stem cell-like features through regulation of self-renewal activity. Methods: The effects of RGE and Rg3 on the proportion of $CD44^{high}/CD24^{low}$ cells, as representative characteristics of stem-like breast cancer cells, were determined by flow cytometry. The mammosphere formation assay was performed to assess self-renewal capacities of breast cancer cells. Aldehyde dehydrogenase activity of MCF-7 mammospheres was measured by the ALDEFLUOR assay. The expression levels of Sox-2, Bmi-1, and P-Akt and the nuclear localization of hypoxia inducible $factor-1{\alpha}$ in MCF-7 mammospheres were verified by immunoblot analysis. Results: Both RGE and Rg3 decreased the viability of breast cancer cells and significantly reduced the populations of $CD44^{high}/CD24^{low}$ in MDA-MB-231 cells. RGE and Rg3 treatment attenuated the expression of Sox-2 and Bmi-1 by inhibiting the nuclear localization of hypoxia inducible $factor-1{\alpha}$ in MCF-7 mammospheres. Suppression of the manifestation of breast cancer stem cell-like properties by Rg3 was mediated through the blockade of Akt-mediated self-renewal signaling. Conclusion: This study suggests that Rg3 has a therapeutic potential targeting breast cancer stem cells.