• Title/Summary/Keyword: Maintenance free

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Comparative Analysis of domestic and foreign Convenience Facilities Laws for the Barrier-free Environment Construction (무장애 생활환경 구축을 위한 국내외 편의시설 관련법 비교분석)

  • Yun, Young-Sam;Kang, Byoung-Keun;Seong, Ki-Chang
    • Journal of The Korea Institute of Healthcare Architecture
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    • v.16 no.2
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    • pp.29-36
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    • 2010
  • Recently, the system that can eliminate discrimination and barrier to disabled, ensure the substantial independence of disabled and help participation in community of disabled is required. Therefore, the purpose of this study is 'construction of the Barrier-free environment' which members of societies included the disabled can live safely in the daily living environment. To achieve this result, this study is shown establishment and complementary direction of the policy related convenient facilities by comparing between domestic and international policy of the convenient facilities. The results of this study are as follows; Firstly, among the conflicting part between related laws and design standards shold be constantly supplemented. Secondly, policy to promote convenient in residential part is needed. Thirdly, composition of the organization that can support professional housing reconstruction is required. Fourthly, from early stage of policy making, not only opinion reflection of users but also maintenance of convenient facilities, continuous maintenance plan and making a policy for verification system is needed. Finally, when the revision of the existing policies or new policies undergo, 'Barrier-free perspective' should be considered.

Basic Study of Distribution Management Model of the Free-Form Concrete Panels (SCM 기법에 의한 비정형 콘크리트 패널의 공급관리 모델 기초연구)

  • Cho, Wonhyun;Na, Youngju;Kim, Sunkuk
    • Proceedings of the Korean Institute of Building Construction Conference
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    • 2016.05a
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    • pp.115-116
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    • 2016
  • Numerous of free-form buildings come up with external appearances using various types of free-form panels. If the panel types produced, transport and installation order and maintenance history are not properly managed, it is difficult to complete a given project successfully. For free-form building projects that satisfy 5 factors (proper time, place, price, product and quantity), a supply chain management technique is applied for distribution management of free-form concrete panels. In addition, the study listed the whole production process of free-form concrete panels and any necessary information, and suggested a basic model for the management. The study result will be a great help in effective distribution management of free-form panels for free-form building projects.

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Viability of eggs, filariform larvae and adults of Stronglyloides venezuelensis (Nematoda: Strongyloidea) maintained in vitro (베네수엘라분선충 (Strongvloides venezuelensis)의 충란, 감염자충 및 성충의 실험관 내 배양)

  • ;M.
    • Parasites, Hosts and Diseases
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    • v.36 no.2
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    • pp.99-108
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    • 1998
  • The present study was performed to check the viability of eggs, filariform larvae and adults of Strongvloines venezueLensis exposed to various conditions for an in vitro maintenance. The eggs in the feces remained viable for about 25 days at $4^{\circ}C$ and 15 days at room temperature. However, the isolated eggs in sterile saline lost their viability within 24 hr at $4^{\circ}C$. The eggs in morula stage were very sensitive to air drying and rapidly lost their viability (=12 hrs. Filariform larvae survived for a maximum period of 45 days in fecal suspension and 28 days in 0.12% nutrient broth in polyvinyl culture bags maintained at $20^{\circ}C$. On the other hand, those isolated from nutrient broth cultures survived for a maximum period of 32 days in tap water and 22 days in sterile saline at $20^{\circ}C$. The mature adult worms obtained from experimentally infected rats survived maximally for 9 days in serum supplemented (10% rat-serum) 0.12% nutrient broth and 4 days in serum free nutrient broth at $37^{\circ}C$ while the culture media were changed at an alternate day. The adult female worms deposited fertile eggs in serum supplemented and serum free nutrient broth cultures, however, the hatched larvae (Ll) were not able to develop to the filariform stage in the culture media and found to die within 24 hr of maintenance. The present findings on an in vitro maintenance of different stages of 5. uenezueLetis may provide useful information for biological and biochemical studies with Strongyloines species. Key words: Strongvloides venezuelensis. viability in vitro maintenance, free-living filariform larvae (L3), embryonation of eggs

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Effects of Extracellular Matrix Protein-derived Signaling on the Maintenance of the Undifferentiated State of Spermatogonial Stem Cells from Porcine Neonatal Testis

  • Park, Min Hee;Park, Ji Eun;Kim, Min Seong;Lee, Kwon Young;Hwang, Jae Yeon;Yun, Jung Im;Choi, Jung Hoon;Lee, Eunsong;Lee, Seung Tae
    • Asian-Australasian Journal of Animal Sciences
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    • v.29 no.10
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    • pp.1398-1406
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    • 2016
  • In general, the seminiferous tubule basement membrane (STBM), comprising laminin, collagen IV, perlecan, and entactin, plays an important role in self-renewal and spermatogenesis of spermatogonial stem cells (SSCs) in the testis. However, among the diverse extracellular matrix (ECM) proteins constituting the STBM, the mechanism by which each regulates SSC fate has yet to be revealed. Accordingly, we investigated the effects of various ECM proteins on the maintenance of the undifferentiated state of SSCs in pigs. First, an extracellular signaling-free culture system was optimized, and alkaline phosphatase (AP) activity and transcriptional regulation of SSC-specific genes were analyzed in porcine SSCs (pSSCs) cultured for 1, 3, and 5 days on non-, laminin- and collagen IV-coated Petri dishes in the optimized culture system. The microenvironment consisting of glial cell-derived neurotrophic factor (GDNF)-supplemented mouse embryonic stem cell culture medium (mESCCM) (GDNF-mESCCM) demonstrated the highest efficiency in the maintenance of AP activity. Moreover, under the established extracellular signaling-free microenvironment, effective maintenance of AP activity and SSC-specific gene expression was detected in pSSCs experiencing laminin-derived signaling. From these results, we believe that laminin can serve as an extracellular niche factor required for the in vitro maintenance of undifferentiated pSSCs in the establishment of the pSSC culture system.

Optimized study of an in vitro 3D culture of preantral follicles in mice

  • Hehe Ren;Yingxin Zhang;Yanping Zhang;Yikai Qiu;Qing Chang;Xiaoli Yu;Xiuying Pei
    • Journal of Veterinary Science
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    • v.24 no.1
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    • pp.4.1-4.16
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    • 2023
  • Background: In vitro culture of preantral follicles is a promising technology for fertility preservation. Objectives: This study aims to investigate an optimized three-dimensional (3D) fetal bovine serum (FBS)-free preantral follicle culture system having a simple and easy operation. Methods: The isolated follicles from mouse ovaries were randomly divided in an ultra-low attachment 96-well plates supplement with FBS or bovine serum albumin (BSA) culture or encapsulated with an alginate supplement with FBS or BSA culture. Meanwhile, estradiol (E2) concentration was assessed through enzyme-linked immunosorbent assay of culture supernatants. The diameter of follicular growth was measured, and the lumen of the follicle was photographed. Spindle microtubules of oocytes were detected via immunofluorescence. The ability of oocytes to fertilize was assessed using in vitro fertilization. Results: The diameters were larger for the growing secondary follicles cultured in ultra-low attachment 96-well plates than in the alginate gel on days 6, 8, and 10 (p < 0.05). Meanwhile, the E2 concentration in the BSA-supplemented medium was significantly higher in the alginate gel than in the other three groups on days 6 and 8 (p < 0.05), and the oocytes in the FBS-free system could complete meiosis and fertilization in vitro. Conclusions: The present study furnishes insights into the mature oocytes obtained from the 3D culture of the preantral follicle by using ultra-low attachment 96-well plate with an FBS-free system in vitro and supports the clinical practices to achieve competent, mature oocytes for in vitro fertilization.

Free Vibrations of Circular Uniform Strips Resting on Two Parameter Elastic Foundation (두 변수 탄성지반으로 지지된 원호형 등단면 띠기초의 자유진동)

  • Lee, Jong-Cheon
    • Journal of the Korea institute for structural maintenance and inspection
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    • v.13 no.1 s.53
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    • pp.125-134
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    • 2009
  • This paper deals with the free vibrations of circular strip foundations which have uniform solid rectangular cross-section. The ground which supports circular strips was modeled as the two parameter elastic foundation. Differential equations governing the flexural-torsional free vibrations of circular strips supported by such foundation were derived, and solved numerically for obtaining the natural frequencies and mode shapes. Boundary condition of free-free ends was considered for numerical examples. Four lowest natural frequencies according to the variations of five system parameters i.e. subtended angle, depth ratio, contact ratio, elasticity ratio and soil parameter are reported in the non-dimensional forms. Also, typical mode shapes of both deformations and stress resultants are presented in the figures. Experiment was conducted for validating the theory developed in this study.

A Study on the Performance Elevation Methods of Next Generation Railway Freight Vehicles (차세대 철도화물차량의 성능향상방안에 관한 연구)

  • Ham Y.S.;Hong J.S.;Oh T.Y.
    • Proceedings of the Korean Society of Precision Engineering Conference
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    • 2005.06a
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    • pp.351-354
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    • 2005
  • Research purpose of this project is intending Maintenance Free of freight car and speed up of freight train. At goods transport as heightening traveling by ship speed of freight train shortening raise railway share of physical distribution and stand on tiptoe to Northeast Asia physical distribution main country to contribute expect. This paper is the performance elevation methods of next generation railway freight vehicles.

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The Reduction of Structure-borne Noise in an Elevated Station(Changdong Station) of Seoul Metro Line No. $1\sim4$ (서울메트로 $1\sim4$호선 고가역(창동역) 고체소음 저감 사례)

  • Kong, Sun-Yong;Oh, Hee-Wan;Kim, Sang-Jin
    • Proceedings of the KSR Conference
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    • 2007.05a
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    • pp.438-443
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    • 2007
  • In the recent railway construction, the concrete slab track is highlighted as the maintenance-free track and the main stream is moving from ballasted track to concrete slab track. However, in spite of many merits of concrete slab track, the higher noise generated from the concrete slab track is a troublesome question to solve and, by this reason, many studies on noise reduction of concrete slab track are carried out. The railway noise can be classified into the reflection noise emitted from wheel/rail contact and the structure-borne noise transmitted through railway structures. In this presentation, we would like to introduce an example of the successful reduction of structure-borne noise at track retrofitting to maintenance-free concrete slab track in elevated Changdong Station which was built with ballasted track on Rahmen structure.

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Shear Strength of Single Anchors in Uncracked and Unreinforced Concrete (비균열·무근콘크리트의 단일앵커 전단내력 평가)

  • Kim, Sung-Yong;Kim, Kyu-Suk
    • Journal of the Korea institute for structural maintenance and inspection
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    • v.7 no.4
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    • pp.171-181
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    • 2003
  • This study concerns the prediction of shear capacity, as governed by concrete breakout failure, concrete pryout failure and steel failure, of single anchors located close to free edge and located far from a free edge and installed in uncracked, unreinforced concrete. For this purpose, the methods to evaluate the shear capacity of the single anchors in concrete are summarized and the experimental data are compared with capacities by the two present methods: the method of ACI 349-90 and concrete capacity design (CCD) method.

A Study On Wear Pattern of Wheel Flange for Urban Railway Vehicle (도시철도 차량 차륜 플랜지의 마모패턴에 관한 연구)

  • Noh, Hang-Nak;Maeng, Hee-Young;Kwon, Seok-Jin
    • Proceedings of the KSR Conference
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    • 2007.11a
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    • pp.71-77
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    • 2007
  • The surface of railway wheel tread in wheel-rail system can not be free from wear because of various circumstance such as railway condition, maintenance condition, weather condition, characteristics of wheel surface's geometrical shape, and vehicle suspension's structural characteristics etc. Therefore, the research on wear reduction and maintenance method are very important to ensure the safety of railway vehicle, to improve car comfort and to decrease maintenance cost. In this study, the wear rates of railway wheel have been periodically measured in terms of the running distance of Electrical Multiple Unit which have been currently operated and the microstructure transformation of wheel tread using replication method have been performed. The results show that the relations between the flange wear and tread microstructure are depended on running distance and it will supply basic data on wheel maintenance.

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