• Title/Summary/Keyword: Low maintenance

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Performance Evaluation of SSD-Index Maintenance Schemes in IR Applications

  • Jin, Du-Seok;Jung, Hoe-Kyung
    • Journal of information and communication convergence engineering
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    • v.8 no.4
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    • pp.377-382
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    • 2010
  • With the advent of flash memory based new storage device (SSD), there is considerable interest within the computer industry in using flash memory based storage devices for many different types of application. The dynamic index structure of large text collections has been a primary issue in the Information Retrieval Applications among them. Previous studies have proven the three approaches to be effective: In- Place, merge-based index structure and a combination of both. The above-mentioned strategies have been researched with the traditional storage device (HDD) which has a constraint on how keep the contiguity of dynamic data. However, in case of the new storage device, we don' have any constraint contiguity problems due to its low access latency time. But, although the new storage device has superiority such as low access latency and improved I/O throughput speeds, it is still not well suited for traditional dynamic index structures because of the poor random write throughput in practical systems. Therefore, using the experimental performance evaluation of various index maintenance schemes on the new storage device, we propose an efficient index structure for new storage device that improves significantly the index maintenance speed without degradation of query performance.

Control system modeling of stock management for civil infrastructure

  • Abe, Masato
    • Smart Structures and Systems
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    • v.15 no.3
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    • pp.609-625
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    • 2015
  • Management of infrastructure stock is essential in sustainability of society, and its analysis and optimization are studied in the light of control system modeling in this paper. At the first part of the paper, cost of stock management is analyzed based on macroscopic statistics on infrastructure stock and economical growth. Stock management burden relative to economy is observed to become larger at low economic growth periods in developed economies. Then, control system modeling of stock management is introduced and by augmenting maintenance actions as control input, dynamic behavior of stock is simulated and compared with existing time history statistics. Assuming steady state conditions, applicability of the model to cross sectional data is also demonstrated. The proposed model is enhanced so that both preventive and corrective maintenance can be included as system inputs, i.e., feedforward and feedback control inputs. Optimal management strategy to achieve specified deteriorated stock level with minimal cost, expressed in terms of preventive and corrective maintenance actions, is derived based on estimated parameter values for corrosion of steel bridges. Relative cost effectiveness of preventive maintenance is shown when target deteriorated stock level is lower.

Bluetooth Low-Energy Current Sensor Compensated Using Piecewise Linear Model

  • Shin, Jung-Won
    • Journal of Sensor Science and Technology
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    • v.29 no.5
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    • pp.283-292
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    • 2020
  • Current sensors that use a Hall element and Hall IC to measure the magnetic fields generated in steel silicon core gaps do not distinguish between direct and alternating currents. Thus, they are primarily used to measure direct current (DC) in industrial equipment. Although such sensors can measure the DC when installed in expensive equipment, ascertaining problems becomes difficult if the equipment is set up in an unexposed space. The control box is only opened during scheduled maintenance or when anomalies occur. Therefore, in this paper, a method is proposed for facilitating the safety management and maintenance of equipment when necessary, instead of waiting for anomalies or scheduled maintenance. A Bluetooth 4.0 low-energy current-sensor system based on near-field communication is used, which compensates for the nonlinearity of the current-sensor output signal using a piecewise linear model. The sensor is controlled using its generic attribute profile. Sensor nodes and cell phones used to check the signals obtained from the sensor at 50-A input currents showed an accuracy of ±1%, exhibiting linearity in all communications within the range of 0 to 50 A, with a stable output voltage for each communication segment.

Perceived Benefits and Barriers According to the Stage of Mammography Adoption in Adult Women (성인 여성의 유방조영술 검진 참여 단계에 따른 이익요인과 장애요인 분석)

  • Hur, Hea Kung;Song, Hee-Young
    • Korean Journal of Adult Nursing
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    • v.17 no.3
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    • pp.474-483
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    • 2005
  • Purpose: This descriptive study was undertaken to explore the distribution of stages of mammography adoption and identify benefits and barriers perceived by women according to the stage of mammography adoption. Methods: A total of 227 women aged between 30 - 60 was selected by the convenient sampling in W city. The instrument developed by the researcher based on the scales of Champion(1993), Champion & Skinner(2003), and Rakowski et al (1992) was used. Results: The distribution of stages of mammography adoption was as following; precontemplation 30.7%, contemplation 23.8%, relapse 20.2%, action 14.4%, and maintenance 10.8%. Women in maintenance and actors showed high scores in benefits and low scores in barriers. Those in relapse reported high scores in both benefits and barriers, while precontemplators and contemplators showed high score in barriers and low scores in benefits. Conclusion: Despite the rate of mammography participation has increased, the proportion of maintenance stage is still low and that of relapse is high. For those in relapse, strategies to eliminate barriers hindering regular and continuous mammography are necessary. For precontemplators and contemplators, detail information including purpose, procedure and benefits of mammography should be given primarily.

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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.

The Development of Maintenance Process in Long-Life Housing (장수명 공동주택 유지관리를 위한 프로세스 구축에 대한 연구)

  • Ji, Jang-Hun;Kim, Soo-Am;Yoon, Sang-Cho
    • Journal of the Korean housing association
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    • v.21 no.3
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    • pp.115-124
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    • 2010
  • The environment which has been destroyed for the national growth since 1960's would seem to offer infinite resources to human, but now, the existence of human being is threatened by the development thoughtless for the environment. The World Powers have concentrated on green growth with eco-friendly resource since the end of 20th century. Korea suggested that the vision was the low carbon for green growth in 2008. It is necessary to supply Long-Life Housing in the green technology in terms of the sustainable housing development based on various life style, life cycle of the residences, the restrain remodeling and redevelopment in construction. This study is aim to establish the development of maintenance process to make continuous inhabitation of Long-Life Housing that has the separated SI for maintenance, durability, variability and remodeling. The maintenance for Long-Life Housing is very important to have more than 50~70 years the long term of life cycle in comparison with Housing. Also, the roles of manager and user are important parts in Long-Life Housing. The present maintenance for Housing is shift and repair works by the routine maintenance and demage. However, The maintenance for Long-Life Housing should consider movement and flexibility. In addition, Long-Life Housing requires the proper process of maintenance because it is different from Housing in housing concept, design and constructions stage. Therefore this study shows the efficient maintenance process for Long-Life Housing.

A Study on Value Orientation of Health of Rural Health Center Milieu (농촌지역 보건소 환경에 있어서의 건강가치관에 관한 일 조사연구)

  • 김순자
    • Journal of Korean Academy of Nursing
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    • v.5 no.1
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    • pp.17-30
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    • 1975
  • The concept and definition of nursing and her role have been changing in accordance with the socio-cultural factors of the initial society. At present, nursing is conceptualized as a health care profession assisting man to restore, maintain and promote health by providing knowledge, wilt strength and resources through various processes of interaction. Man′s behavior, of individual and group activities for health inclusive, is driven by the initial man′s value orientation. The purpose of this study is to investigate the value orientation regarding health of rural health center milieu in order to give data for; 1. the planning for the delivery of community nursing service, 2. the health education plan at all level of nursing care activities, and 3. the planning of curriculum for nursing education. A hundred opinion leaders among the labor population residing in rural areas (P-group), hundred and six professional nurses at rural health centers (N-group) were indirectly interviewed through questionaries. And ninety five of N-group were interviewed likewise of their perceptions of P-group (NP-group) from July 15, to October 15, 1974. The result is as follows: 1. Maintenance of health is revealed to be the most valued component for man′s happiness in all the three groups. (P-group: 7.30 S. D.=1.31), (N-group :7.84 S. D. =49), and (NP-group : 5.93 S. D. =2.28) 2. The average value score of the maintenance of health revealed significant difference by P〈.001 level between each of the three groups. (Between N-group and P-group : T= -4.07 P and NP ; T=-6.93, N and NP: T=-9.35) 3. Basic health maintenance activities necessary for maintenance and promotion of personal health were moderately valued by all the three groups, P-group ; 3.74 (S. D. =.43) , N-group: 3.52 (S. D. =.34), NP-group: 3.07 (S. D. :.55) Among the 8 categories of basic health maintenance activities, "food intake" was highly valued by P-group (mean value score; 4.00 S. D=.51) , "exercise and rest" and "personal cleanliness" was highly valued by both P-group (4.02, 4.08) and N-group (4.08, 4.22). 4. The mean value score of basic health maintenance activities revealed significant difference by P〈.001 level between each of the three groups (between P-group and N-group: T=-4, 07, N-and NP: T=-6.93, P and NP T=-9.35) 5. Among the 30 questionaries, dynamic activities for health maintenance were more valued in comparison to passive activities in an tile three groups. 6. In N-group, correlation between the value of basic health maintenance activities and the personal health status personal revealed moderate significance. Correlation between the value of basic health maintenance activities and the age revealed low significance. 7. In group, correlation between the value of basic health maintenance activities and; perception of personal health status revealed non significance, between the age and sex revealed low sign affiance, and between the educational status revealed moderate significance. Recommendations are as follows ; 1. The efforts towards alteration of value orientation concerning health in general in community nursing practice de focussed be that of family Planning. 2. In order to prepare professional nurses competent in understanding individual and group, social science and behavioral science be strength ended in planning nursing curriculum. 3. Milieu of nursing experience during nursing education be Planned to begin at simple nursing problem and move towards complex, f. e. home care towards health crisis situation in order to achieve dynamic role mastery.

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A Study on Low-flow Frequency Analysis Using Dam Inflow (댐 유입량 자료를 이용한 갈수빈도해석에 대한 연구)

  • Jung, Younghun;Nam, Woo Sung;Shin, Hongjoon;Heo, Jun-Haeng
    • KSCE Journal of Civil and Environmental Engineering Research
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    • v.32 no.6B
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    • pp.363-371
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    • 2012
  • In this study, the low-flow frequency analysis was performed to determine the low-flow standard of dam maintenance flow for Hwacheon and Chuncheon dams. For this purpose, two methods (case 1: low-flow frequency analysis using the monthly inflow data of the specified return periods, case 2: low-flow frequency analysis using the difference of monthly accumulated inflow) were applied. As a result, it is found that the monthly inflow data of the return periods by reflecting the statistical characteristics of Hwacheon and Chuncheon dams can be utilized to determine the standard of maintenance flow or water level.

Derivation of Sustainability Factors of LID Facility and Strategy of Citizen Participation for Management (LID 시설의 지속가능성 관리인자 도출 및 시민참여 관리방안)

  • Kim, Youngman;Kim, Lee-hyung
    • Journal of Wetlands Research
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    • v.21 no.1
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    • pp.57-65
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    • 2019
  • LID(Low Impact Development) facility classified as a social infrastructure can maintain landscape sustainability and functional sustainability through continuous maintenance and management. Since LID is a natural-based solution, the sustainability can be secured through the management of weeds, wastes and vegetation. The LID facility is distributed in the city and is an infrastructure that can be managed through citizen participation because of simple maintenance. Therefore, this study was conducted to investigate the maintenance factors affecting the sustainability of the LID facilities and to suggest measures for maintenance by investigating the participation of the peoples. The factors for landscape sustainability were derived to waste and weed management. Also the factors for functional sustainability were assessed to identification and management of dead bodies and selection of applicable soil and plant species. The citizens showed high agreement of more than 80% in the questionnaires on expanding and managing LID facilities, enacting LID ordinances, and participating in the national movement. The intention to participate in LID management linked to jobs was about 64%, indicating that LID could become a job for the vulnerable. Maintenance of the LID can easily be carried out by non-specialists, which can lead to citizen participation with low cost for each facility. The maintenance cost for citizen participation can be allocated from the social infrastructure management cost reduced by LID application of the local government and the social welfare budget of the central government.

A Turnout without Movable Parts for Magnetically Levitated Vehicles with Hybrid Magnets

  • Kakinoki, Toshio;Yamaguchi, Hitoshi;Yoshinaga, Naoya;Mukai, Eiichi;Nishi, Hiroyuki
    • Journal of international Conference on Electrical Machines and Systems
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    • v.3 no.3
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    • pp.312-316
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    • 2014
  • This paper describes a turnout without movable parts for magnetically levitated vehicles with hybrid magnets, which have been studied by the authors in place of streetcars. Their low construction cost and low maintenance is key to their practical use. Magnetic levitation systems using forces of attraction can generate guidance force automatically, but the damping force against lateral motion is negligible. However, the lateral damping characteristic was improved by using divided iron type magnets and rails. Using this turnout without movable parts will facilitate smooth direction switching.