• Journal of Broadcast Engineering
• /
• v.20 no.4
• /
• pp.497-508
• /
• 2015

Current communication networks consist of channels with various throughputs, protocols, and packet loss rates. Moreover, there are also diverse user multimedia consumption devices having different capabilities and screen sizes. Thus, a practical necessity of scalability on video coding have been gradually increasing. Recently, The Scalable High Efficiency Video Coding(SHVC) standard is developed by Joint Collaborative Team on Video Coding(JCT-VC) organized in cooperation with MPEG of ISO/IEC and VCEG of ITU-T. This paper introduces coding tools of SHVC including adopted and unadopted tools discussed in the process of the SHVC standardization. Furthermore, the individual tool and combined tool set are evaluated in terms of coding efficiency relative to a single layer coding structure. This analysis would be useful for developing a fast SHVC encoder as well as researching on a new scalable coding tool.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
• /
• v.29 no.4
• /
• pp.212-218
• /
• 2003

Matrix metalloproteinases (MMPs) play an important role in the normal morphogenesis, maintenance, and repair of matrix and also have important functions in pathologic conditions characterized by excessive degradation of extracellular matrix, such as rheumatoid arthritis, osteoarthritis, periodontitis and in tumor invasion and metastasis. In this study, expression of MMP-1 and -2 mRNA in retrodiscal tissue of the temporomandibular joint (TMJ) was examined and compared with magnetic resonance imaging (MRI) and surgical findings. MMP mRNAs in the retrodiscal tissue samples were detected by reverse transcription - polymerase chain reaction. TMJ internal derangement (ID) was categorized as normal disc position, disc displacement with reduction, early stage of disc displacement without reduction (DDsR) and late stage of DDsR. TMJ osteoarthrosis (OA) was classified with normal, mild and advanced OA. The amount of synovial fluid collection was divided into not detected, small, large and extremely large amount on MR T2-weighted imaging. Perforation and adhesion were examined during open surgery of the TMJ. Six out of 37 samples were excluded because of little amount of extracted total mRNA. MMP-2 mRNA was detected whole joints, and so the MMP-2 mRNA seems to be expressed normally in retrodiscal tissue. However, MMP-1 mRNA was expressed in 8 of 31 joints. Frequencies of MMP-1 mRNA expression according to the TMJ IDs, amount of synovial fluid and surgical findings made no significant difference. MMP-1 mRNA was detected more frequently in OA groups (7/16 joints, 43.8%) than in normal bony structure group (1/15 joints, 6.7%). Expression of MMP-1 mRNA in retrodiscal tissue might be related with OA of the TMJ.

• Journal of Welding and Joining
• /
• v.17 no.1
• /
• pp.124-132
• /
• 1999

Thermal fatigue strength of the solder joints is the most critical issue for TSOP(Thin Small Outline Package) because the leads of this package are extremely short and thermal deformation cannot be absorbed by the deflection of the lead. And the TSOP body can be subject to early fatigue failures in thermal cycle environments. This paper was discussed distribution of thermal stresses at near the joint between silicon chip and die pad and investigated their reliability of solder joints of TSOP with 42 alloy clad lead frame on printed circuit board through FEM and 3 different thermal cycling tests. It has been found that the stress concentration around the encapsulated edge structure for internal crack between the silicon chip and Cu alloy die pad. And using 42 alloy clad, The reliability of TSOP body was improved. In case of using 42 alloy clad die pad(t=0.03mm). $$\sigma$_{VMmax}$ is 69Mpa. It is showed that 15% improvement of the strength in the TSOP body in comparison with using Cu alloy die pad $($\sigma$_{VMmax}$=81MPa). In solder joint of TSOP, the maximum equivalent plastic strain and Von Mises stress concentrate on the heel of solder fillet and crack was initiated in it's region and propagated through the interface between lead and solder. Finally, the modified Manson-Coffin equation and relationship of the ratio of $N_{f}$ to nest(η) and cumulative fracture probability(f) with respect to the deviations of the 50% fracture probability life $(N_{f 50%})$ were achieved.

• Proceedings of the Korean Institute of Building Construction Conference
• /
• 2002.05a
• /
• pp.1-6
• /
• 2002

The study offer a suggestion that from result in being a case to efflorescence for decrease a plan: $\circled1$ A efflorescence of concreat a structure will be the prograss plan; In the materials, depress use to the water-sand in the construction, admonish unification of front and rear in the environment, consideration requisite concreat don't the occurrence efflorescence. $\circled2$ Ma sonry building efflorescence establish a ventilation opening and a waterway to ma sonry the times avoid the winter or the rainy season. Ma sonry building efflorescence will be make good among a brick to a brick interval closely mortar. $\circled3$ Tile building, tile of plasticity temperature is appropriate, reduce the deviation, parapet part of efflorescence will be make good closely mortar. A construction material part a meterial developing need Perfection of construction a efflorescence occurrence is the minimum, a plan Part developed so on, composition of a ommection field systematic effort need a efflorescence Prevention a kind of detail.

• Proceedings of the KWS Conference
• /
• 2005.11a
• /
• pp.189-191
• /
• 2005

Dissimilar joining of AI 6013-T4 alloys and austenite stainless steel was carried out using friction stir welding technique. Microstructures near the weld zone and mechanical properties of the joint have been investigated. Microstructures in the stainless steel side and AI alloy were depended on the thermo-mechanical condition which they received. TEM micrographs revealed that the interface region was composed of the mixed layers of elongated stainless steel and ultra-fine grained AI alloy and intermetallic compound layer which was identified as the $Al_{4}Fe$ with hexagonal close packed structure. Mechanical properties were lower than those of 6013 AI alloy base metal, because tool inserting location was deviated to AI alloy from the butt line, which resulted in the lack of the stirring.

• Proceedings of the Korean Society For Composite Materials Conference
• /
• 2004.04a
• /
• pp.165-168
• /
• 2004

Carbon nanotube is a geometrical frame-like structure and the primary bonds between two nearest-neighboring atoms act like beam members, whereas an individual atom acts as the joint of the related beam members. The sectional property parameters of these beam members are obtained from molecular mechanics. Computations of the elastic deformation of single-walled carbon nanotubes reveal that the Young's moduli of carbon nanotubes vary with the tube diameter and are affected by their helicity. With increasing tube diameter, the Young's moduli of carbon nanotubes approach the Young's modulus of graphite.

• Composites Research
• /
• v.34 no.2
• /
• pp.96-100
• /
• 2021

The lightweight industry continuously demands reliable near-net-shape fabrication where the preform just out-of-machine is close to the final shape. In this study, different half-finished preforms are made π-beams. Then the preforms are unfolded to make a 3D shape with integrated structure of fibers, providing easier handling in the further processing of composites. Several 3D textile preforms are made using weaving technique and are examined after resin infusion for mechanical properties such as inter-laminar shear strength, compressive strength and tensile strength. Considering that the time and labor are important parameters in modern production, 3D weaving technique reduces the manufacturing steps and therefore the costs, such as hand-lay up of textile layers, cutting, and converting into preform shape. Hence this 3D weaving technique offers many possibilities for new applications with efficient composite production.

• International Journal of High-Rise Buildings
• /
• v.13 no.2
• /
• pp.113-145
• /
• 2024

Bamboo is seen as a low cost, lightweight, widely available and environmental-friendly material. In Vietnam, it also connects deeply to our culture. However, it wasn't seen as a viable material for large structures before VTN Architects. Furthermore, Vietnamese cities are facing the same environmental problems as many developing metropolises in the world. Globally, climate change is a serious issue. The need for sustainable construction material is clear. The increasing development of eco-tourism in Vietnam and Asia is also a background. These become the background to the foundation and the development of bamboo architecture by VTN Architects. The journal analyses our development of bamboo construction, joints, structures, and how to use them to realise space and to create eco-friendly architecture. We will talk about our process of bamboo procurement, our construction methods, our unique joint system, how we make a frame unit and how we construct VTN bamboo structures from units.

• Smart Structures and Systems
• /
• v.22 no.4
• /
• pp.383-397
• /
• 2018

Traditional base isolation systems focus on isolating the seismic response of a structure in the horizontal direction. However, in regions where the vertical earthquake excitation is significant (such as near-fault region), a traditional base-isolated building exhibits a significant vertical vibration. To eliminate this shortcoming, a rocking-isolated system named Telescopic Column (TC) is proposed in this paper. Detailed rocking and isolation mechanism of the TC system is presented. The seismic performance of the TC is compared with the traditional elastomeric bearing (EB) and friction pendulum (FP) base-isolated systems. A 4-storey reinforced concrete moment-resisting frame (RC-MRF) is selected as the reference superstructure. The seismic response of the reference superstructure in terms of column axial forces, base shears, floor accelerations, inter-storey drift ratios (IDR) and collapse margin ratios (CMRs) are evaluated using OpenSees. The results of the nonlinear dynamic analysis subjected to multi-directional earthquake excitations show that the superstructure equipped with the newly proposed TC is more resilient and exhibits a superior response with higher margin of safety against collapse when compared with the same superstructure with the traditional base-isolation (BI) system.

• Steel and Composite Structures
• /
• v.30 no.3
• /
• pp.217-230
• /
• 2019

One of the most important design criteria in underground structure is to design lightweight protective layers to resist significant blast loads. Sandwich blast resistant panels are commonly used to protect underground structures. The front face of the sandwich panel is designed to resist the blast load and the core is designed to mitigate the blast energy from reaching the back panel. The design is to allow the sandwich panel to be repaired efficiently. Hence, the underground structure can be used under repeated blast loads. In this study, a novel sandwich panel, named RC panel - Helical springs- RC panel (RHR) sandwich panel, which consists of normal strength reinforced concrete (RC) panels at the front and the back and steel compression helical springs in the middle, is proposed. In this study, a detailed 3D nonlinear numerical analysis is proposed using the nonlinear finite element software, AUTODYN. The accuracy of the blast load and RHR Sandwich panel modelling are validated using available experimental results. The results show that the proposed finite element model can be used efficiently and effectively to simulate the nonlinear dynamic behaviour of the newly proposed RHR sandwich panels under different ranges of free air blast loads. Detailed parameter study is then conducted using the validated finite element model. The results show that the newly proposed RHR sandwich panel can be used as a reliable and effective lightweight protective layer for underground structures.