• Title/Summary/Keyword: Bearing selection

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Two-Way Car Ferry Thrust Shaft Primary Support Part Structural Integrity Evaluation (양방향 카페리 추진축 1차 지지부 구조건전성 평가)

  • Kang, Byoung-Mo;Oh, Young-Cheol;Bae, Dong-Gyun;Ko, Jae-Yong
    • Proceedings of the Korean Institute of Navigation and Port Research Conference
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    • 2013.10a
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    • pp.163-164
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    • 2013
  • Two-Way CAR-FERRY land and islands, islands to islands, the connection between sustainable marine transportation in conjunction with the increasing demand of tourists, according to the associated coastal maritime tourism and passenger transport has a role. Subsequent Two-Way CAR-FERRY and the increased ease of use due to berthing maritime accidents can be reduced. Two-Way CAR-FERRY as the draft (even) in the state on both sides of the propeller, because the propeller due to the small diameter, low speed forward flight by the reaction at the shaft and propeller damage can occur. Engine output accordingly, linear and torsional vibration reducer by, elastic coupling selection transverse vibration and shaft alignment (Shaft alignment) considering the shaft design (bearing size, width, thickness) and the primary drive shaft support portion of the hull structure of evaluated for quality.

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A Study on the Pump System Design Optimization for Regional Water Supply Facilities (광역상수도용 펌프의 규격 최적결정방법에 관한 연구)

  • Roh, Hyung-woon;Suh, Sang-Ho;Kim, Kyung-Yup;Kim, Sung-Won;Kim, Il-Soo;Park, Jong-Moon;Park, HeeKyung;Park, No-Suk;Lee, Bong-Joo;Lee, Jeung-Woo;Lee, Young-Bum;Lee, Young-Ho;Kim, Sang-Gyun
    • 유체기계공업학회:학술대회논문집
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    • 2001.11a
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    • pp.159-164
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    • 2001
  • An extensive range of pumping facilities are employed in the regional water supply system in metropolitan areas, and optimization and the systematic combination of the pump facilities have direct bearing on the stability and economy of the water supply system concerned. These systems must be able to guarantee stability, efficiency and offer high reliability. Preparation of metropolitan area regional water supply system construction project must include a basic plan which takes into account the suitability of pumping facilities to be used, the environment in which facilities will be installed, man-power requirements and basic operational and management policies. This paper contains over-all analysis of the management of metropolitan area regional water supply systems and highlights the cause of Inefficiency and energy waste and puts forward a remedial plan of action. In addition, pump/motor specification programs were developed using Visual Basic to assist selection of the same.

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Effect of the Curing Behavior on Electrical and Mechanical Properties of Multifunctional Structural Electrolyte (경화 거동에 따른 다기능 구조 전해질의 전기적 기계적 특성 연구)

  • Kwon, Suk Jin;Choi, U Hyeok;Jung, Byung Mun;Kim, Yang Do;Lee, Sang Bok
    • Composites Research
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    • v.29 no.6
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    • pp.395-400
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    • 2016
  • Recently, many research groups have studied on the epoxy-based multifunctional electrolyte to develop the structural composite bearing high mechanical properties without sacrificing the ionic conductivity at the same time. The studies on the optimal content and material selection for structural electrolyte have been published, while its curing behavior has not much analyzed yet. In this study, epoxy-based structural electrolyte containing solid electrolyte was prepared by varying the curing temperature and time. In addition, the ionic conductivities and mechanical properties of specimens were measured. We also find out the optimal hardening condition where the epoxy domain enables to be hardened within the range of temperature at which the thermal decomposition of electrolyte does not occur. Finally, we propose the multifunctional structural electrolyte showing achievable electrical and mechanical properties (282 MPa and $9{\times}10^{-6}S/cm@25^{\circ}C$).

Analysis of Sucess Factors on Crop Switching Management: Applying the HERO Model (작목전환의 단계별 성공요인 분석 -HERO 모델 적용-)

  • Ahn, Kyeong Ah;Park, Sung Hee;Jo, Hea Bin;Choe, Young Chan
    • Journal of Agricultural Extension & Community Development
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    • v.19 no.3
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    • pp.699-727
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    • 2012
  • Conditions of farm crop switching are affected by several important external factors such as agricultural products import opening, policy support, and climate change. Farming environment is always changing; barriers to imports are becoming lower and lower because of FTA and others, and climate change affects a boundary line of cultivation. Those situations give farmers motivation to change crops in order to cope with them. In addition, crop switching has been done in response to the local government measures about purchase of local agricultural products according to the local food and the expansion of organic agricultural products in school meal. Even though the favorable environment toward crop switching has been created, there are not many researches or outcomes regarding crop switching. Only few studies focus on the list of decision-making in crop switching, and locally suitable crop selection is not treated. In order to utilize crop switching as a farm management strategy, the proper frame should be studied and practical researches on application possibility also need. Therefore, study on crop switching is in a timely, proactive manner because farms catch the chance of expansion of school meal by changing crops. This paper applies HERO model used for venture foundation process to crop switching process. Success factors of HERO model are comprised of Habitate, Entrepreneurship, Resource, and Opportunity, and these phased application factors are applied to crop switching process. By doing so, each phase success factor of crop switching can be uncovered. Three farm organizations supplying organic agricultural products to schools are studied in Gyeonggi province. As a result, the stabilization stage cannot be achieved because of the habitate conditions and social conditions with low risk bearing of crop switching and current school meal systems are the main problems to block the diversification of risks. In order to succeed in crop switching, constructing the habitate in local districts or in systems of school meal is more effective than supporting each farm.

Teak (Tectona grandis Linn. f.): A Renowned Commercial Timber Species

  • Palanisamy, K.;Hegde, Maheshwar;Yi, Jae-Seon
    • Journal of Forest and Environmental Science
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    • v.25 no.1
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    • pp.1-24
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    • 2009
  • Teak (Tectona grandis) is one of the most valuable timber yielding species in the world, with predominant distribution in tropical or sub-tropical countries. However, natural teak available only in few countries like India, Myanmar, Laos People's Democratic Republic and Thailand. Teak grows well in deep, well-drained alluvial soils, fairly moist, warm, tropical climate with pH ranges from 6.5-7.5. Teak is cultivated in many Asian, African and South American countries for timber production. The global teak plantations are estimated to be three million hectare with major share in India (44%) followed by Indonesia (33%). India is considered as richest genetic resources of teak with large areas of natural teak bearing forests (8.9 million ha), plantations (1.5 million ha), clonal seed orchards (1000 ha) and seed production areas (5000 ha). The studies on diversity of teak populations showed that teak is an out crossing species with major portion of diversity present within the populations. The productivity and quality of teak timber varies depending upon the site and environmental conditions. Teak wood is moderately heavy, strong and tough,straight grained, coarse textured and ring porous with specific gravity varies from 0.55 to 0.70. The sapwood is white to pale yellow in colour and clearly demarcated while heartwood is dark brown or dark golden yellow in colour. Teak is one of the most durable timbers in the world, practically, impervious to fungus and white ant attack and resistant to decay. Teak wood is used in ship and boat constructions, furnitures and aesthetic needs. Genetic improvement programmes have been undertaken in countries like Thailand, India, Malaysia and Indonesia. The programme includes provenance identification and testing, plus tree selection and clonal multiplication, establishment of seed orchards and controlled hybridization. Several aspects like phenology, reproductive biology, fruit characteristics, silvicultural practices for cultivation, pest and diseases problems, production of improved planting stock, harvesting and marketing, wood properties and future tree improvement strategy to enhance productivity have been discussed in this paper.

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Genotype $\times$ Environment Interaction for Yield in Sesame (Sesamum indicum L.)

  • Shim, Kang-Bo;Kang, Churl-Whan;Hwang, Chung-Dong;Pae, Suk-Bok;Choi, Kyung-Jin;Byun, Jae-Cheon;Park, Keum-Yong
    • KOREAN JOURNAL OF CROP SCIENCE
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    • v.53 no.3
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    • pp.297-302
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    • 2008
  • Application of genotype by environment ($G\;{\times}\;E$) interaction would be used for identifying optimum test condition of the varietal adaptation in the establishment of breeding purpose. Yield and yield components were used to perform additive main effect and multiplicative interaction (AMMI) analysis. Significant difference for $G\;{\times}\;E$ interaction were observed for all variable examined. For yield, 0.18 of total sum of squares corresponded to $G\;{\times}\;E$ interaction. Correlation analysis was carried out between genotypic scores of the first interaction principal component axis (IPCA 1) for agronomic characters. Significant correlations were observed between IPCA 1 for yield and capsule bearing stem length (CBSL), number of capsule per plant (NOC). The biplot of grain yield means for IPCA1 which accounted for 34% of the variation in total treatment sums of squares showed different reaction according to $G\;{\times}\;E$ interaction, genotypes and environments. Taegu showed relatively lower positive IPCA1 scores, and it also showed smaller coefficient variation of yield mean where it is recommendable as a optimal site for the sesame cultivar adaptation and evaluation trial. In case of variables, Yangbaek and M1 showed relatively lower IPCA1 scores, but the score direction showed opposite each other on the graph. Ansan, Miryang1, Miryang4, and Miryang6 seemed to be similar group in view of yield response against IPCA1 scores. These results will be helpful to select experimental site for sesame in Korea to minimize $G\;{\times}\;E$ interaction for the selection of promising genotype with higher stability.

Constructing Database and Probabilistic Analysis for Ultimate Bearing Capacity of Aggregate Pier (쇄석다짐말뚝의 극한지지력 데이터베이스 구축 및 통계학적 분석)

  • Park, Joon-Mo;Kim, Bum-Joo;Jang, Yeon-Soo
    • Journal of the Korean Geotechnical Society
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    • v.30 no.8
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    • pp.25-37
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    • 2014
  • In load and resistance factor design (LRFD) method, resistance factors are typically calibrated using resistance bias factors obtained from either only the data within ${\pm}2{\sigma}$ or the data except the tail values of an assumed probability distribution to increase the reliability of the database. However, the data selection approach has a shortcoming that any low-quality data inadvertently included in the database may not be removed. In this study, a data quality evaluation method, developed based on the quality of static load test results, the engineering characteristics of in-situ soil, and the dimension of aggregate piers, is proposed for use in constructing database. For the evaluation of the method, a total 65 static load test results collected from various literatures, including static load test reports, were analyzed. Depending on the quality of the database, the comparison between bias factors, coefficients of variation, and resistance factors showed that uncertainty in estimating bias factors can be reduced by using the proposed data quality evaluation method when constructing database.

Structural System Selection and Highlights of Changsha IFC T1 Tower

  • Jianlong, Zhou;Daoyuan, Lu;Liang, Huang;Jun, Ji;Jun, Zhu;Jingyu, Wang
    • International Journal of High-Rise Buildings
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    • v.3 no.2
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    • pp.99-106
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    • 2014
  • This paper presents the determination of the structural system of the Changsha IFC T1 tower with 452 m in architectural height and 440.45 m in structural height. Sensitivity analyses are carried out by varying the location of belt trusses and outriggers. The enhancement of seismic capacity of the outer frame by reasonably adjusting the column size is confirmed based on parametric studies. The results from construction simulation including the non-load effect of structures demonstrate that the deformation of vertical members has little effect on the load-bearing capacity of belt trusses and outriggers. The elastoplastic time-history analysis shows that the overall structure under rare earthquake load remains in an elastic state. The influence of the frame shear ratio and frame overturning moment ratio on the proposed model and equivalent mega column model is investigated. It is found that the frame overturning moment ratio is more applicable for judging the resistance of the outer frame against lateral loads. Comparison is made on the variation of these two effects between a classical frame-core tube-outrigger structure and a structure with diagonal braces between super columns under rare earthquakes. The results indicate that plasticity development of the top core cube of the braced structure may be significantly improved.

Identifying significant earthquake intensity measures for evaluating seismic damage and fragility of nuclear power plant structures

  • Nguyen, Duy-Duan;Thusa, Bidhek;Han, Tong-Seok;Lee, Tae-Hyung
    • Nuclear Engineering and Technology
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    • v.52 no.1
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    • pp.192-205
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    • 2020
  • Seismic design practices and seismic response analyses of civil structures and nuclear power plants (NPPs) have conventionally used the peak ground acceleration (PGA) or spectral acceleration (Sa) as an intensity measure (IM) of an earthquake. However, there are many other earthquake IMs that were proposed by various researchers. The aim of this study is to investigate the correlation between seismic responses of NPP components and 23 earthquake IMs and identify the best IMs for correlating with damage of NPP structures. Particularly, low- and high-frequency ground motion records are separately accounted in correlation analyses. An advanced power reactor NPP in Korea, APR1400, is selected for numerical analyses where containment and auxiliary buildings are modeled using SAP2000. Floor displacements and accelerations are monitored for the non- and base-isolated NPP structures while shear deformations of the base isolator are additionally monitored for the base-isolated NPP. A series of Pearson's correlation coefficients are calculated to recognize the correlation between each of the 23 earthquake IMs and responses of NPP structures. The numerical results demonstrate that there is a significant difference in the correlation between earthquake IMs and seismic responses of non-isolated NPP structures considering low- and high-frequency ground motion groups. Meanwhile, a trivial discrepancy of the correlation is observed in the case of the base-isolated NPP subjected to the two groups of ground motions. Moreover, a selection of PGA or Sa for seismic response analyses of NPP structures in the high-frequency seismic regions may not be the best option. Additionally, a set of fragility curves are thereafter developed for the base-isolated NPP based on the shear deformation of lead rubber bearing (LRB) with respect to the strongly correlated IMs. The results reveal that the probability of damage to the structure is higher for low-frequency earthquakes compared with that of high-frequency ground motions.

Differential effect of electroacupuncture analgesia depending on the point selection in a rat model of CFA-induced arthritis (CFA로 유도한 관절염에서 선혈(選穴)에 따른 전침(電鍼)의 진통효과 차이)

  • Yang, Bum-Sik;Koo, Sung-Tae;Kim, Kyoung-Sik;Sohn, In-Cheul
    • Korean Journal of Acupuncture
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    • v.22 no.1
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    • pp.95-108
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    • 2005
  • Objective : In the present study, the effect of electroacupuncture (EA) applied to several acupoints and non-acupoint in CFA-induced knee arthritis was examined. Methods : A common source of persistent pain in humans is arthritis. Arthritis was induced by injection of CFA $125\;{\mu}l$ into knee joint cavity under enflurane anesthesia. The rat subsequently showed swelling of the ankle and a reduced stepping force of the affected limb for the next several days. The reduced stepping force of the limb was presumably due to a painful knee. EA was applied to either of $LR_2,\;LI_4$, or non-acupoint on the contralateral forelimb for 30 min under gaseous anesthesia. After the termination of EA, behavioral tests measuring stepping force were periodically conducted during the next 4 h. Results : EA applied to $LR_2$ point produced a significant improvement of stepping force of the affected foot lasting for at least 2 h. However, neigher $LI_4$ point nor non-point produced any significant increase of weight bearing force. The improvement of stepping pressure was interpreted as an analgesic effect. The analgesic effect was specific to the acupuncture point since the analgesic effect on CFA-induced knee arthritic pain model could not be mimicked by EA applied to a point, $LI_4$ or non-acupoint. In addition, both NO production and iNOS protein expression increased by arthritis were suppressed by EA applied to $LR_2$ point. Conclusion : These data suggest that EA produces a potent analgesic effect in the rat model of CFA-induced knee arthritis. This analgesic effect is produced by applying EA to an acupoint at opposite side from the painful area in a stimulus point-specific way.

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