• KCI Concrete Journal
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• v.11 no.3
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• pp.181-189
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• 1999

An experimental study was performed on the Pull-out behavior of 90-deg standard hooks from the exterior beam-column connections. the effects of the number of hooked bars and fiber reinforcement of the joint area were investigated with the following conclusions : (1) Under the pull-out action of hooked bars. the damage and cracking of joint area the number of hooks pulling out from a joint increases; (2) Substitution of the transverse column (confining) reinforcement with steel fibers at the joint region effectively reduces the extent of cracking in exterior joints caused by the pull-out of hooked bars; (3) The pull-out strength and post-peak ductility of hooked bars are adversely influenced by the increase in number of hooks pulling out from an exterior joint. Current hooked bar anchorage design guidelines may be improved by considering the effect of the number of hooked bars on anchorage conditions at the exterior joints; and (4) The strength and ductility of hooked bars under pull-out forces are positively influenced by substituting the conventional confining reinforcement of exterior joints with steel fibers . The application of steel fibers to the exterior joints is an effective technique for improving the anchorage conditions of hooked bars, and also for reducing the congestion of reinforcement in the beam-column connections.

• Journal of Satellite, Information and Communications
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• v.12 no.2
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• pp.33-37
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• 2017

This paper suggests a new reliable push pull converter. The proposed push-pull converter have additional two diodes comparing with conventional push-pull converter. When one of two MOSFETs of the push-pull converter is on state, the other MOSFET is automatically off state due to adding additional diodes. Therefore, the converter is under electric noise environments, the converter avoids short circuit due to turning on of two MOSFETs. In this paper, the suggested converter has been simulated by PLECS software for 100 kHz switching frequency. In simulation, the current of the converter switches increases about 10 % for $20{\mu}sec$ electric noise environments. However, the converter operates very reliably without any short circuit conditions.

• Journal of the Korean Geotechnical Society
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• v.24 no.8
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• pp.43-52
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• 2008

In this study, the verification test and creep test for both a single-rebar nail and a multi-rebar nail are carried out to investigate a tensile strength for both nails. The adhesion effects between a rebar and a cement grout, a mobilized frictional force induced by pull-out load, and load transfer characteristics are examined. The results obtained from the field pull-out tests and from the numerical analysis using $FLAC^{2D}$ which is one of the programs developed based on the finite difference method are analyzed and compared for a single-rebar nail and a multi-rebar nail. The field pull-out test results for a multi-rebar nail relative to a single-rebar nail show that a tensile failure load is relatively large and the pull-out loads are well transferred to the ground in deep depth.

• Journal of the Korean Society of Food Culture
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• v.24 no.4
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• pp.401-412
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• 2009

The aims of study were to provide basic data for the internationalization of Contract Foodservice Management Companies (CFMC) and to gain a better understanding of internal push-and-pull factors through in-depth interviews. The interviewees were managers of four large CFMCs and one small-to-medium CFMC. The non-structured interview format employed an interview guide of open-ended questions. All interviews were digitally recorded and notes were taken simultaneously by an interview assistant. The narrative data analysis involved transcription, coding, classification by categories, and content analysis. Eighty-eight codes were generated from the interview analyses, and the subordinate variables uncovered included seven push factors, eight pull factors, one interactive factor, and 10 internal dynamics. These factors will be useful in further studies of the internal operations of specific CFMCs, and more generally, the practical condition of the industry.

• Journal of Korean Orthopaedic Sports Medicine
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• v.11 no.1
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• pp.37-43
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• 2012

Purpose: This study is to evaluate the clinical results of pull-out suture for root tear of posterior horn of medial meniscus. Materials and Methods: Between March 2006 and February 2011, We studied 40 cases with the root tear of posterior horn of medial meniscus which follow up more than 1 years. Mean age was 49.5 years old. We excluded osteoarthritis or varus deformity patients more than 5 degrees. pull-out suture was performed to the patients with grade 0-2 of Kellgren and Lawrence classification. According to Outerbridge classification, evaluation of cartilage damage was performed during arthroscopy. Evaluation of clinical result was used the Lysholm score. Results: The mean pre-operation Lysholm score was 63.9 and post-operation score was 86.3. The complete failure rate was 3 of 40 cases (7.5%). Twenty of 40 cases (50%) showed cartilage lesions in weight bearing portion of medial femoral condyle which were 12 cases in grade 1, 5 cases in grade 2 and 3 cases in grade 3 according to the Outerbridge classification. Conclusion: In the treatment of pull-out suture for root tear of posterior horn of medial meniscus, exclusion of more than moderate arthritis or varus deformity is very importment. Pull-out suture seems to be a useful treatment of the root tear of posterior horn of medial meniscus in mild osteoarthritis or varus deformity of middle ages.

• Journal of Forest and Environmental Science
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• v.24 no.2
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• pp.111-118
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• 2008

Pull-out resistance tests of root were carried out for 7 shrub species which are mainly used greening of deteriorated forest slope. Mean pull-out resistance forces of Aralia elata, Salix koreensis and Stephanandra incisa were 37.26 kgf, 34.56 kgf and 26.00 kgf, respectively. The pull-out resistances were high as collar diameter and volume of the root increased. Correlations between root collar diameter and root volume were high in Rubus crataegifolius, but on the other hand, the correlation was lowest in Zanthoxylum schinifolium. There were significant differences in pull-out resistance by root collar diameters, and the difference of pull-out resistance by species showed only below 20 ml root volume.

• The KIPS Transactions:PartA
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• v.11A no.3
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• pp.207-212
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• 2004

This paper provides the higher user QoS(Quality of Service) by analyzing media service model between server and client in single VoD(Video on Demand) environment and applying it to parallel VoD environment. Media service model is divided into the Client Pull, Server Push, and IPP(Interleaving Pull & Push) model. A server sends data based on client's request in the Client Pull Model. A server one-sidedly sends data without client's request in the Server Pull model. And the WP model unites above two models. For a parallel VoD environment, We built the PMSS system which provides the parallel media streaming services that one client is simultaneously served by several servers. In the single and parallel VoD environment, We compare and analyze the performance of service models with respect to network delay and data size in buffer. In this experiment, we found that IPP service model keeps the least network delay and stable client buffer in the parallel VoD environment. This result shows that PMSS can provide the more quality of service.

• International Journal of Highway Engineering
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• v.8 no.1 s.27
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• pp.33-43
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• 2006

Pull-out strength of tie-bin used in pavement construction is not an issue because those are embedded in newly placed concrete slabs. However, sufficient pull-out strength should be secured in widening constructions because, in case, the tie-bars are inserted into drilled holes of the existing slabs with liquid filler. Insufficient pull-out strength will result in lowered load transfer efficiency between adjacent slabs in addition to poor serviceability and durability due to joint widening. The pull-out strength of the tie-bars installed by current method is evaluated and improved methods are proposed. The field pull-out strength obtained by the current method was only 42.7% of required strength. Its first counterproposal is using to insert the liquid filler into drilled holes and stoppers to prevent it from flowing out of the holes. However, this method was not judged to secure desired level of quality control. The second counterproposal which substitutes the existing type of the tie-bars by SL anchor bolts was judged to secure sufficient pull out-strength in addition to the quality control and constructibility.

• Journal of Korean Society of Occupational and Environmental Hygiene
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• v.21 no.4
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• pp.209-214
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• 2011

Objectives: To assess the risk of pushing or pulling the yarn-carrying cart, the survey was performed in some fiber manufacturing factories. Methods: We selected 6 fiber-twisting factories which agreed to in-site survey of their workplace. To measure both initial and sustained forces of the push-pull tasks, Chatillon CSD500 dynamometer(2004, Ametek, USA) was used. The mean of 3 tests for the same cart was adopted as the measured forces. Height and width of cart, weight of spooled yarns, and distance of movement were also measured. Inspection of cart wheel, moving path, and the actual hand position while moving was done. Results: More than one pushing or pulling task exceeded the push-pull force limits of design goal in 5 factories. Though the cart was not loaded the heaviest weight in the factory, the measured push or pull force exceeded the limits several times. A few cart wheels were worn out and tangled with pieces of yarn. It was also observed some holes in the moving path. Conclusions: While the push-pull task is not included in the 11 scopes of over-burdened work notified by Korean government, it should be recognized as risk factor of work-related musculoskeletal disorders. The maintenance work such as regular change and frequent cleaning of cart wheel, the use of fitting wheel, and flattening of bumpy floor through the moving path should be advised importantly in the worksite management of work-related musculoskeletal disorders.

• Journal of the Korean Geosynthetics Society
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• v.8 no.4
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• pp.19-25
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• 2009

In this study, field pull-out tests were performed for steel pipe nailing installed foldable wedge and non-wedge type steel pipe nailing under the same test conditions. This is to evaluate pull-out resistance improvement effect of steel pipe nailing installed foldable wedge. Evaluating for field pull-out characteristics of steel pipe nailing installed foldable wedge was performed through analysis of ultimate pull-out resistance ($T_L$), ultimate unit skin friction ($q_s$, $u_{max}$), tensile normal stiffness ($K_{\beta}$), tension of nail. As a result, the steel pipe nailing installed foldable wedge have an effect of pull-out resistance increased about 30% in comparison with non-wedge type steel pipe nailing.