• Title/Summary/Keyword: Maintenance and Repair

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Effect of 1,2,3,4,6-penta-O-gallolyl-β-ᴅ-glucose on markers of cognitive function in human neuroblastoma SK-N-SH cell line (1,2,3,4,6-Penta-O-gallolyl-β-ᴅ-glucose가 인간 유래 신경모세포주인 SK-N-SH세포의 인지기능 표지자에 미치는 영향)

  • Yoon, Hyeon Seok;Park, So Yeon;Kim, Yoon Hee
    • Korean Journal of Food Science and Technology
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    • v.53 no.6
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    • pp.715-721
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    • 2021
  • Cognitive impairment and Alzheimer's disease are serious social problems associated with the rising elderly population in Korea. 1,2,3,4,6-Penta-O-galloyl-β-ᴅ-glucopyranose (PGG) is a gallotannin isolated from medicinal plants such as Rhus chinensis. This study was performed to evaluate the effect of PGG on biomarkers related to cognitive function in human neuroblastoma SK-N-SH cells. Inhibition of acetylcholinesterase (AChE) activity is considered to be one of the main therapeutic strategies. PGG inhibited AChE activity in the test tube as well as in SK-N-SH cells. In addition, PGG induced protein and mRNA expression of brain-derived neurotrophic factor (BDNF), which is a mammalian neurotrophin that plays major roles in the development, maintenance, repair, and survival of neuronal populations. As one of the underlying molecular mechanisms that induce BDNF expression, PGG induced the activation of Ca2+/calmodulin (CaM)-dependent protein kinase II (CaMKII)-cAMP response element binding protein (CREB) pathway. In conclusion, PGG may be an useful material for improving cognitive function.

Back-scattering Characteristic Analysis for SAR Calibration Site (SAR 검보정 Site 구축을 위한 후방 산란 특성 분석)

  • Lee, Taeseung;Yang, Dochul
    • Korean Journal of Remote Sensing
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    • v.37 no.2
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    • pp.305-319
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    • 2021
  • The overseas calibration sites such as Mongolia used for Korea Multi-purpose Satellite (KOMPSAT-5 or K5), have a disadvantage in that maintenance and repair costs are high and immediate response is difficult when an unexpected problem occurs. Accordingly, the necessity of establishing a domestic SAR calibration site was suggested, but the progress of related research is insignificant. In this paper, we investigated what conditions should be satisfied in terms of backscattering characteristics to construct a site for SAR satellite image quality evaluation and calibration. First of all, it was selected first by applying general indicators such as accessibility and availability among places recommended as satellite image calibration candidate sitesin Korea. Next, three places, site A (Goheung-gun, Jeollanam-do), site B (Jeonju-si, Jeollabuk-do), and site C (Daedeok Research Complex, Daejeon), were selected as the final candidates because they are relatively wide and easy to install AT or CR. Site A, located in Goheung-gun, Jeollanam-do, was best considered in terms of slope measurements, minimum site area to obtain ISLR, uniformity of DN values and backscatter coefficients, interference by strong reflectors, and backscatter clutter level.

A Study on Real-Time SOC Structure Behavior Evaluation System using Big Data (Big data를 이용한 실시간 SOC 구조물 거동분석 시스템 연구)

  • Jung-Youl Choi;Jae-Min Han;Dae-Hui Ahn;Jee-Seung Chung
    • The Journal of the Convergence on Culture Technology
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    • v.9 no.1
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    • pp.691-695
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    • 2023
  • Currently, the utilization of measurement results of the automated measurement system is very low and is at the level of providing only fragmentary measurement results. In this study, we are going to study a structure behavior analysis 3D display system with high precision and reliability for automated measurement data obtained by constructing big data by transmitting massive data values measured in real time to the cloud and using a Python-based algorithm. As a result of the study, as a system that can evaluate the behavior of a structure to a manager in real time, it provides analysis data in real time without significant restrictions regardless of the type of measurement data and sensor, and derived it as a 3D display. In addition, it was analyzed that the manager could grasp the behavior graph of the structure in real time and more easily judge the derivation of the weak part of the structure through data analysis. In the future, by analyzing the behavior of structures in three dimensions using past and present data, it is expected that more effective measurement results can be obtained in terms of repair, reinforcement, and maintenance of realistic structures.

Multi-family Housing Complex Breakdown Structure for Decision Making on Rehabilitation (노후 공동주택 개선여부 의사결정을 위한 공동주택 분류체계 개발)

  • Hong, Tae-Hoon;Kim, Hyun-Joong;Koo, Choong-Wan;Park, Sung-Ki
    • Korean Journal of Construction Engineering and Management
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    • v.12 no.6
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    • pp.101-109
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    • 2011
  • As climate change is becoming the main issue, various efforts are focused on saving building energy consumption both at home and abroad. In particular, it is very important to save energy by maintenance, repair and rehabilitation of existing multi-family housing complex, because energy consumption in residential buildings is not only forming a great part of gross energy consumption in Korea but the number of deteriorated complexes is also sharply increasing. However, energy saving is not considered as a main factor in decision making on rehabilitation project. Also, any supporting tool is not appropriately prepared in existing process. As the first step for development of decision support system on rehabilitation, this paper developed a breakdown structure, which makes clusters of multi-family housing complexes. Decision tree, one of data mining methods, was used to make clusters based on the characteristics and energy consumption data of multi-family housing complexes. Energy saving and CO2 reduction will be maximized by considering energy consumption during rehabilitation process of multi-family housing complex, based on these results and following research.

A Study on the Improvement of Defect Management through Judicial Precedents of Landscape Construction Defect (조경공사 하자판례 분석을 통한 하자처리 개선방안 연구)

  • Jung, Myeung-Muk;Lee, Sang-Suk
    • Journal of the Korean Institute of Landscape Architecture
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    • v.40 no.1
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    • pp.81-91
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    • 2012
  • The purpose of this study was to analyze judicial precedents related on landscape construction defects(JPLCD) and suggested the improvement plan for dealing with it. The results are as the following: 1. Landscape construction defects litigations have been increased so far since 2000 and the duration of original trial was approximately 603 days, while appeal trials took up to 550 days. Therefore, the analysis revealed that settlement of disputes were lengthy and wasteful to consumers and constructors. 2. Judgement's cost accepted by the judge was only 53.6% of appraisal's cost appraised by appraiser, therefore it revealed appraiser overestimated the repair cost of landscape construction defects. 3. According to work classification categorized by Landscape Construction Standard Specification(2008) of the Korean Institute of Landscape Architecture, landscape planting amounted to 75% of JPLCD and plaintiff(consumers)'s prevailing rate of it reached 77% to be a serious burden to constructors. 4. According to JPLCD categorized by the type of dispute, defects caused by consumer's negligence for maintenance amounted to 29% and defendant(constructors)'s prevailing rate of it reached 64% to be the main responsibility of consumers. Further study will be required to make the judge standard of landscape construction defects through legal and technical research.

The Examination of Load Carrying Capacity Based on Existing Data for Improved Safety Assessment Method of Expressway Bridges (고속도로 교량의 개선된 안전성 평가방안을 위한 실측자료에 기초한 공용 내하력 검토)

  • Lee, Jong Ho;Han, Sung Ho;Sin, Jae Chul
    • KSCE Journal of Civil and Environmental Engineering Research
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    • v.29 no.6A
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    • pp.597-605
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    • 2009
  • The safety of expressway bridges was estimated by checking the external condition rank based on the nondestructive inspection and material test and by measuring load carrying capacity based on the result of load test. Although the load carrying capacity of the bridges was clearly low compared to the design standard, it was examined that many of the bridges have good external condition rank relatively. Also, it can be assured that load carrying capacity shows a considerable difference according to various condition even though the bridges have similar construction year and a structural type. Therefore, this study showed various problems of the current safety measurement of expressway bridges by considering the status of the expressway bridges, external condition rank, and method of safety diagnosis and repair, rehabilitation for maintenance. Based on the existing data of over 400 expressway bridges, the load carrying capacity was analyzed quantitatively considering bridge type, serviced life, design live load, external condition rank and traffic count as variables. The result of this study will be expected to provide the basic information for a reasonable safety assessment of expressway bridge.

Characteristics of Residential Areas in the Transition Zone of Central Daegu (대구시 중심시가지 점이지대의 주거지 특성)

  • Kim, Ta-Yeul;Jin, Won-Hyung;Yang, Seong-Hwan
    • Journal of the Korean association of regional geographers
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    • v.17 no.6
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    • pp.710-725
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    • 2011
  • The purpose of this study is to analyze both residential conditions and the resident impressions of the transition zone of central Daegu. The results drawn from a questionnaire survey of the residents are summarized as follows: 1) The proportion of people over the age of 60 living on a low income is high and consists mostly of retired citizens who have lived in the transition zone, in their own homes, for an extended length of time 2) The condition of infrastructure in the transition zone is very poor, however, despite the housing deterioration, the internal repair and maintenance of houses is more satisfactory than their external appearance. 3) Residential satisfaction received high ratings in every category except pollution and housing price. This response appears to stem from the easy commute of residents as well as the ready availability of facilities in the city center. 4) In terms of residential satisfaction, the residents can be divided into two groups. The first, with a high satisfaction rate, consists mainly of senior citizens who possess both personal homes and a stable living, having resided in the city center for most of their lives. The second, with a lower satisfaction rate, is composed mostly of younger residents who have lived temporarily in inexpensive rental homes. As a results, the residential area in the transition zone of central Daegu does not appear to be a problematic area like the slum of the West, but instead a stable settlement for its residents.

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Protective Effect of Rhus Semialata M. extract on Epidermal Stem Cells against UV Irradiation (자외선 조사된 상피 줄기세포에 대한 붉나무 추출물의 보호 효과)

  • Woo, Hyunjoo;You, Jiyoung;Park, Deokhoon;Jung, Eunsun
    • Journal of the Society of Cosmetic Scientists of Korea
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    • v.45 no.4
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    • pp.415-422
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    • 2019
  • Human epidermal stem cells(ESCs) residing in the basement membrane of the skin have an important role in maintenance of skin homeostasis of epidermal layer. Although, ESCs provide new cells to repair damaged tissue in response to tissue injury, subsets of stem cells remain in the quiescent state protected from differentiation and senescence for prolonged survivals. In this perspective, the stem cell niche, which is specific microenvironment composed of niche cells and an extracellular matrix(ECM), supplies the relevant signal to save stem cells from microenvironmental damages. The expression of stemness marker on the surface of ESCs contributes to the attachment on their ECM of the basement membrane, which lead to growth potential and apoptotic resistance against environmental stimuli. In this study, we observed that UV irradiation, a major factor of environmental stimuli, reduced the expression of α2, β1 and α6 integrin in ESCs. Rhus Semialata M extract(RSE) showed inhibitory effect on the UVB-induced reduction of integrin expression. Furthermore, RSE could upregulate the expression of Col-IV and Laminin, which contribute to the attachment of ESCs. These results indicated that RSE could be a potent ingredient for the protection of ESCs from UV irradiation by increasing the expression of integrin and substrate ECM components at their niche.

A Study of the Combination Method for Earthwork Equipments Using the Environmental Loads and Costs (토공사 환경오염물질 부하량 및 공사비를 이용한 장비조합방법 연구)

  • Kang, Min-Ho;Park, Hyung-Keun
    • KSCE Journal of Civil and Environmental Engineering Research
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    • v.33 no.3
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    • pp.1215-1224
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    • 2013
  • Great efforts have been made worldwide to reduce the Green House Gas (GHG) emission following the "Kyoto Protocol" declared during the United Nations Framework Convention on Climate Change in 1997. Many industries have restructured to meet the standard set by the Protocol. However, no clear guidance has been established for the purpose of reducing the GHG emission in construction industry. In addition, no significant effort has been made to conserve the energy during construction activities. For more effective energy saving in construction industry, it is essential to collect data about energy consumption, quantity of environmental emissions and costs. However, most studies on sustainable construction have been concentrated on the use of equipment, maintenance and repair works during construction due to the difficulties of collecting such data. This study suggests a method to select the most environmentally friendly equipment combination for earthwork with comparing environmental loads and costs using the database of Life Cycle Inventory in the Ministry of Knowledge Economy and Ministry of Environment of Korea.

Study on ALDT Optimal Setting Considering Retention Level of Repair Items (수리품목 보유수준을 고려한 ALDT 최적화 설정방안 연구)

  • Jun, Joon-Hyung;Hwang, Kyoung-Hwan
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.21 no.3
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    • pp.269-275
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    • 2020
  • RAM of elements to support weapon systems is conducted at the initial development phase and standard is suggested to accomplish strategy requirement performance from a design spec. Operational availability is a key point of the military's ability to ensure combat readiness and to win the battle. In the weapon system development phase, operational availability is used as a development standard. The military provides ALDT, operation and standby time, which are elements of operational availability. ALDT is a key element of operational availability that must be maintained for combat readiness, as it depends on the aging of a weapon system, maintenance policies and geographical conditions. Operational Availability to be set at the development phase has many differences from the operational availability that is analyzed in the actual operational phase because ALDT is applied as a simple assumption. In the paper, we analyzed ALDT applying the decision tree method through failure data acquired from initial operation. Through this study, we have devised the optimal ALDT setting method to achieve operational availability about operation when the weapons system is unstable.