• Tribology and Lubricants
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• v.21 no.3
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• pp.107-113
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• 2005

Micro/nano adhesion and friction properties of self-assembled monolayers (SAMs) with different head- and end-group were experimentally studied according to the coating methods. Various kinds of SAM having different spacer chains (C10 and C18), head-group and end-group were deposited onto Si-wafer by dipping and chemical vapour deposition (CVD) methods under atmospheric pressure, where the deposited SAM resulted in the hydrophobic nature. The adhesion and friction properties between tip and SAM surfaces under nano scale applied load were measured using an atomic force microscope (AFM) and also those under micro scale applied load were measured using a ball-on-flat type micro-tribotester. Surface roughness and water contact angles were measured with SPM (scanning probe microscope) and contact anglemeter respectively. Results showed that water contact angles of SAMs with the end-group of fluorine show higher relatively than those of hydrogen. SAMs with the end-group of fluorine show lower nano-adhesion but higher micro/nanofriction than those with hydrogen. Water contact angles of SAMs coated by CVD method show high values compared to those by dipping method. SAMs coated by CVD method show the increase of nano-adhesion but the decrease of nano-friction. Nano-adhesion and friction mechanism of SAMs with different end-group was proposed in a view of size of fluorocarbon molecule.

• Steel and Composite Structures
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• v.18 no.6
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• pp.1423-1450
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• 2015

The paper presents the details and results of an experimental study on bolted end-plate joints of industrial type steel building frames. The investigated joints are commonly used in Lindab-Astron industrial buildings and are optimized for manufacturing, erection and durability. The aim of the research was to provide an experimental background for the design model development by studying load-bearing capacity of joints, bolt force distribution, and end-plate deformations. Because of the special joint details, (i.e., joints with four bolts in one bolt-row and HammerHead arrangements), the Eurocode 3 standardized component model had to be improved and extended. The experimental programme included six different end-plate and bolt arrangements and covered sixteen specimens. The steel grade of test specimens was S355, the bolt diameter M20, whereas the bolt grade was 8.8 and 10.9 for the two series. The end-plate thickness varied between 12 mm and 24 mm. The specimens were investigated under pure bending conditions using a four-point-bending test arrangement. In all tests the typical displacements and the bolt force distribution were measured. The end-plate plastic deformations were measured after the tests by an automatic measuring device. The measured data were presented and evaluated by the moment-bolt-row force and moment-distance from centre of compression diagrams and by the deformed end-plate surfaces. From the results the typical failure modes and the joint behaviour were specified and presented. Furthermore the influence of the end-plate thickness and the pretension of the bolts on the behaviour of bolted joints were analysed.

• Journal of the Ergonomics Society of Korea
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• v.17 no.3
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• pp.1-11
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• 1998

Focuses of this study are to investigate the usage status of head-restraint system(H/R) in usual driving and to simulate usage conditions of H/R at rear-end crashes. The usage of H/R was categorized into five classes according to the height and distance from occupant's head ; Large-$90^{\circ}$ H/R for enough height and short distance. Large-$70^{\circ}$ H/R for enough height and long distance. Small-$90^{\circ}$ H/R for low height and short distance. Small-$70^{\circ}$ H/R for low height and long distance. and No H/R. Then. these five conditions were tested to find out the degree of neck injuries by using a car-crash simulation package, DYNAMAN. Results from the investigation of H/R usage show that most of drivers(60%) have Small-$70^{\circ}$ H/R for low height and long distance. Results from the simulation performed at 15mph and 30mph show that: 1) at 15 mph, there is a possibility for neck injury in Small-$90^{\circ}$ H/R and Small-$70^{\circ}$ H/R. 2) at 30 mph. there is a high possibility of death in Small-$70^{\circ}$ H/R and Small-$90^{\circ}$ H/R.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.23 no.7 s.166
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• pp.1196-1204
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• 1999

adaption of the model predictions is highly desirable. In general, the width deviation at the head and tail ends of strip may be different from that of the steady state region. Therefore, the dynamic edger corrections can be used to compensate the width deviations which would otherwise occur. For the precise width control, the effect of edger roll gap and rolling conditions on the width deviation of head and tail ends of strip has been investigated and the effective method to decrease width deviation has been proposed. On-line application of dynamic edger control method in this study shows about 50% width compensation at the head end of the strip, and near perfect compensation at the tail end of strip.

• Progress in Superconductivity and Cryogenics
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• v.14 no.3
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• pp.48-52
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• 2012

This paper describes experimental study on the orientation dependence of GM-type pulse tube refrigerator with helium and neon as working gas. A pulse tube refrigerator generates refrigeration work with gas expansion by gas displacer in the pulse tube. The pulse tube is only filled with working gas and there exists secondary flow due to large temperature difference between cold-end and warm-end. The stability of secondary flow is affected by orientation of cold-head and thus cooling performance is deteriorated by gas mixing due to secondary flow. In this study, a single stage GM-type pulse tube with orifice valve as a phase control device is fabricated and tested. The fabricated pulse tube refrigerator is tested with two different working gases of helium and neon. First, optimal valve opening and operating frequency are determined with experimental results of no-load test. And then, the variation of no-load temperature as orientation angle of cold-head is measured for two different working gases. Effect of orientation dependence of cold-head as working gas is discussed with experimental results.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2012.05a
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• pp.733-734
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• 2012

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2010.05a
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• pp.845-846
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• 2010

• Korean Journal of Head & Neck Oncology
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• v.3 no.1
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• pp.5-13
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• 1987

Cancer of the head and neck is an uncommon disease accounting for 5 % of all cancers. In an anatomic area so readily visible and palpable for examination without special and expensive diagnositic tools, it is unfortunate that many patients still present with advanced diseases. Since the prognosis is so intimately related to stage of disease, it is very important to detect the earliest stage of cancer with a complete head and neck examination. In the evaluation of cancer at any anatomic site, the description of the extent of the lesion is important. Not only does proper staging of the tumor lead to make decision of the most appropriate treatment, it also serves as a guide for the results of treatment. Proper staging demands a careful clinical assesment of the extent of the cancer. The current staging system for head and neck cancer uses the TNM system devised by American Joint Committee for Cancer Staging and End Result Reporting. T represent the primary tumor, N, regional nodal metastases, and M, distant metastases. The detection, diagnosis, and appropriate treatment of eary cancer will result in improved survival.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.8 no.5
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• pp.1-12
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• 2008

The multimedia streaming service in NGN architecture is not only to deliver video streaming (VoD, Broadcasting TV, etc.) but also to provide new services and service bundles, such as Triple Play (IPTV + VoIP + Internet). Among these services, Internet Protocol Television (IPTV) is becoming a convergence of communication, content, computing, as well as an integration of broadcasting and telecommunication services. In this paper, we addresses enhanced IPTV management scheme aspect of E2E from Home Network to Head End Center over NGN to support efficient service management with a full quality of service (QoS) guarantee.

• The Magazine of the IEIE
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• v.35 no.9
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• pp.25-36
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• 2008