• Tunnel and Underground Space
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• v.10 no.2
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• pp.196-210
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• 2000

This study was aimed to verify the validity of the flexural toughness evaluation method of steel fiber reinforced shotcrete(SFRS) currently being adopted by Korea Highway Corporation(KHC). Total 33 beam specimens using six different kinds of steel fiber products were prepared at tunnel construction sites and flexural toughness tests were executed at laboratory. Equivalent flexural strengths and toughness quotients were evaluated from the tests following the KHC guide iud these were compared with the quality grades determined under the guides proposed by ASTM, ITA and EFNARC. To discard the disadvantage that the toughness quotient could be influenced by flexural strength when following the KHC guide, a modification substituting the designed flexural strength for the flexural strength in the toughness quotient calculation formula was proposed to rate the quality of SFRS more adequately.

• Structural Engineering and Mechanics
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• v.74 no.4
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• pp.457-470
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• 2020

The force resisting ability of a connection has direct implications on the overall response of a timber framed structure to various actions, thereby governing the integrity and safety of such constructions. The behavior of timber framed structures has been studied by many researchers by testing full-scale-connections in timber frames so as to establish consistent design provisions on the same. However, much emphasis in this approach has been unidirectional, that has focused on a particular connection configuration, with no research output stressing on the refinement of the existing connection details in order to optimize their performance. In this regard, addition of adhesive to dowelled timber connections is an economically effective technique that has a potential to improve their performance. Therefore, a comparative study to evaluate the performance of various full-scale timber frame Nailed connections (Bridled Tenon, Cross Halved, Dovetail Halved and Mortise Tenon) supplemented by adhesive with respect to Nailed-Only counterparts under tensile loading has been investigated in this paper. The load-deformation values measured have been used to calculate stiffness, load capacity and ductility in both the connection forms (with and without adhesion) which in turn have been compared to other configurations along with the observed failure modes. The observed load capacity of the tested models has also been compared to the design strengths predicted by National Design Specifications (NDS-2018) for timber construction. Additionally, the experimental behavior was validated by developing non-linear finite element models in ABAQUS. All the results showed incorporation of adhesive to be an efficient and an economical technique in significantly enhancing the performance of various timber nailed connections under tensile action. Thus, this research is novel in a sense that it not only explores the tensile behavior of different nailed joint configurations common in timber construction but also stresses on improvising the same in a logical manner hence making it distinctive in its approach.

• Journal of the Microelectronics and Packaging Society
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• v.14 no.2 s.43
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• pp.23-33
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• 2007

The growing environmental regulation governs the use of lead by RoHS, WEEE, and then. The electronic industry is moving to replace Pb-bearing solder with Pb-free solder. To use the Pb-free solder, microelectronic industry needs consequently the new reliability appraisal such as the packaging for high temperature process, various mechanical change caused by new solder, and the development of Pb-free sloder for long life of product. The evaluation of solder bar and mechanical properties of joint were performed compared with international standard, and new appraisal standard was established. The solderability and spread ability of Sn-0.7Cu solder material showed up to the standard. Shear test of solder joint using by the solder resulted that the shear strengths after thermal shock or after aging were not much lower than the shear strength of as-soldered and that they were also up to the standard.

• Journal of Welding and Joining
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• v.20 no.4
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• pp.505-509
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• 2002

Pb is considered to be eliminated from solder, due to its toxicity. However, melting temperatures of most Pb-free solders are known higher than that of Sn37Pb. Therefore, there is a difficulty to apply Pb-free solders to electronic industry. Since Sn3Ag8Bi5In has relatively lower melting range as $188~200^{\circ}C$, on this study. Wettability and soldering characteristics of Sn3Ag8Bi5In solder in BGA were investigated to solve for what kind of problem. Zero cross time, wetting time, and equilibrium force of Sn3Ag8Bi5In solder for Cu and plated Cu such as Sn, Ni, and Au/Ni-plated on Cu were estimated. Plated Sn on Cu showed best wettability for zero cross time, wetting time and equilibrium farce. Shear strength of the reflowed joint with Sn3Ag8Bi5In ball in BGA was investigated. Diameter of the ball was 0.5mm, UBM(under bump metallurgy) was $Au(0.5\mu\textrm{m})Ni(5\mu\textrm{m})/Cu(18\mu\textrm{m})$ and flux was RMA type. For the reflow soldering, the peak reflow temperature was changed in the range of $220~250^{\circ}C$, and conveyor speed was 0.6m/min.. The shear strength of Sn3Ag8Bi5In ball showed similar level as those of Sn37Pb. The soldered balls are aged at $110^{\circ}C$ for 36days and their shear strengths were evaluated. The shear strength of Sn3Ag8Bi5In ball was increased from 480gf to 580gf by aging for 5 days.

• Archives of Plastic Surgery
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• v.42 no.5
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• pp.614-618
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• 2015

Background Hand strength deficit following digital replantation is usually attributed to the mechanical deficiency of the replanted digit. Zone 1 replantation, however, should not be associated with any mechanical deficit, as the joint and tendon are intact. We evaluate shortterm motor functions in patients who have undergone single-digit zone 1 replantation. Methods A single-institution retrospective review was performed for all patients who underwent zone 1 replantation. Hand and pinch strengths were evaluated using standard dynamometers. Each set of measurements was pooled according to follow-up periods (within 1 month, 1 to 2 months, 2 to 3 months, and after 3 months). The uninjured hand was used as reference for measurements. Results The review identified 53 patients who had undergone zone 1 replantation and presented for follow-up visits. Compared to the uninjured hand, dynamometer measurements revealed significantly less strength for the hand with replanted digit at one month. The relative mean grip, pulp, and key pinch strength were 31%, 46%, and 48% of the uninjured hand. These three strength measurements gradually increased, with relative strength measurements of 59%, 70%, and 78% for 4-month follow up. Conclusions Despite the lack of joint or tendon injury, strength of the injured hand was significantly lower than that of the uninjured hand during the 4 months following replantation. Improved rehabilitation strategies are needed to diminish the short-term negative impact that an isolated zone 1 replantation has on the overall hand strength.

• Journal of muscle and joint health
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• v.2 no.2
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• pp.197-208
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• 1995

The purpose of this study is to describe specific system manifestations and suggested nursing interventions in patients with lupus. Lupus is a chronic, inflammatory, multisystemic disorder of the immune system. Antibodies are formed which react against the person's own normal tissue. This abnormal response can be very damaging and leads to the many manifestations of the lupus. Lupus can affect any part of the body, and patients experience symptoms in organs involved. So lupus patients have integumentary, blood, central nervous system, eye, gastrointestinal, musculoskeletal, kidney, heart and lining membranes, reproductive system involvement. The courses are unpredictable and very individualized. Lupus varies greatly in severity from mild cases requiring minimal interventions to those in which significant damage occurs to vital organs such as the lungs, heart, kidney and brain which ultimately can be fatal. In addition to direct physical care, the nursing professional has an excellent position from which to support the lupus patient. Patients need assistance with receiving current, accurate information about the disease process and also to be helped in developing realistic expectations and goals. Nursing interventions for the patient with lupus is challenge drawing on at the resources, knowledge and strengths the nursing teams have to offer. Because of the unpredictable, highly individualized and frequently changing the nature of the disease itself as well as the intricacy of the patient's needs. The nurse has a key role in its management. The patient and nurse, working together, have much to offer each other. These are of inestimable value to the patient. As the nurse listens to the patient and learns what problems the patient perceives, can guide the patient in a self-help program that allows to adapt to living with a chronic illness.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.37 no.8
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• pp.751-758
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• 2009

Failure strengths of composite single-lap adhesive joints were investigated with various parameters such as manufacturing method, overlap length and adherend thickness. A total of 335 single-lap joint specimens were tested under tension. Specimens were fabricated with 4 different manufacturing processes; cocuring without and with adhesive, secondary bonding and co-bonding. Each manufacturing process has 5 different overlap lengths and 4 different thicknesses, respectively. As expected, failure strength is higher in thicker adherend joints and lower in larger overlap length specimens. Interesting result is that the secondary bonded joints show the higher strength than the cobonded and cocured joints with adhesive, and give close or even higher strength compared with non-adhesive cocured case.

• Korean Journal of Cognitive Science
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• v.30 no.1
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• pp.1-30
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• 2019

The main goal of this paper is to understand the underlying cognitive mechanisms of collaborative learning and how it can be supported by technology. The paper first overviews changes in conceptions of learning and distinguishes different types of joint works including collaborative learning. Cognitive mechanisms of collaborative learning are examined in terms of resource pooling, facilitation of constructive activities, knowledge co-construction, and supports for monitoring and regulation. Socio-emotional mechanisms of collaborative learning moderate the directions and strengths of these cognitive mechanisms. Technology supports these mechanisms in a number of different ways. Seven major supports technology provides for collaborative learning are discussed. A deeper understanding of the cognitive mechanisms of collaborative learning can help us to harness the benefits of collaborative learning better and also to develop more sophisticated tools supporting collaborative learning.

• Composites Research
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• v.20 no.5
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• pp.26-33
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• 2007

Pull-out and shear strengths of insert Joints of sandwich structure were investigated by experiment. Specimens were prepared by cocuring of nomex honeycomb core and carbon-epoxy composite face using an adhesive FM73. A total of 75 specimens with 10 different types depending on the core height and density, face thickness, and loading direction were tested. In the test under pull-out loading, although both the core height and density affect the failure loads, the effect of cell density is more serious. Dominant factor fur failure loads of the joints under shear loading is face thickness and the effect of core height is negligible. In the joint with same dimension, failure loads vary depending on the potted area of the core, particularly in the pull-out test.

• Korea Trade Review
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• v.45 no.6
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• pp.133-156
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• 2020

This study analyzed the research trend of the papers in the field of customs clearance published from the first issue of the Korean Trade Review to the August 2020 issue. The research method used mixed methods. This method uses both quantitative and qualitative methods, and is a research method to make use of the strengths and weaknesses of each research method. The quantitative study results are as follows. First, an average of 0.7 papers were published for the entire period, but since 2006, an average of 1.2 papers have been published, and the overall interest is increasing. Second, in the case of researchers, the proportion of joint research was slightly higher, with 43.8% of independent research and 56.2% of joint research. In particular, the ratio of 3 or more people is also increasing to 21. Third, looking at the trends by research subject, it was found that among the research fields, there were relatively more studies in the fields of FTA, country of origin, and CISG than in the fields of tariff policy, tariff system and legislation. Fourth, Domestic studies accounted for 75.2% and overseas studies 24.8%, with a high proportion of domestic studies, 13.4 articles in domestic literature, 12.2 articles overseas, and 40 articles supporting research funding. The results of qualitative research need to secure diversity in terms of the generality and specificity of the research topic, and that research in industry-academia or public-private connection should increase, and research from the point of view of "why" rather than "how" Suggested that it is necessary.