• Journal of KIISE:Information Networking
• /
• v.34 no.3
• /
• pp.203-217
• /
• 2007

In this paper, a performance evaluation model of Networks with the multiple-buffered crossbar switches is proposed and examined. Buffered switch technique is well known to solve the data collision problem of the switch networks. The characteristic of a network with crossbar switches is determined by both the connection pattern of the switches and the limitation of data flow in a each switch. In this thesis, the evaluation models of three different networks : Multistage interconnection network, Fat-tree network, and other ordinary communication network are developed. The proposed evaluation model is developed by investigating the transfer patterns of data packets in a switch with output-buffers. Two important parameters of the network performance, throughput and delay, are evaluated. The proposed model takes simple and primitive switch networks, i.e., no flow control and drop packet, to demonstrate analysis procedures clearly. It, however, can not only be applied to any other complicate modern switch networks that have intelligent flow control but also estimate the performance of any size networks with multiple-buffered switches. To validate the proposed analysis model, the simulation is carried out on the various sizes of networks that uses the multiple buffered crossbar switches. It is shown that both the analysis and the simulation results match closely. It is also observed that the increasing rate of Normalized Throughput is reduced and the Network Delay is getting bigger as the buffer size increased.

• Journal of IKEEE
• /
• v.1 no.1 s.1
• /
• pp.31-46
• /
• 1997

In this paper, a parallel Optimal Best-First search Branch-and-Bound(B&B) algorithm(pobs) is designed and evaluated for MIN-based multiprocessor systems. The proposed algorithm decomposes a problem into G subproblems, where each subproblem is processed on a group of P processors. Each processor group uses tile sub-Global Best-First search technique to find a local solution. The local solutions are broadcasted through the network to compute the global solution. This broadcast provides not only the comparison of G local solutions but also the load balancing among the processor groups. A performance analysis is then conducted to estimate the speed-up of the proposed parallel B&B algorithm. The analytical model is developed based on the probabilistic properties of the B&B algorithm. It considers both the computation time and communication overheads to evaluate the realistic performance of the algorithm under the parallel processing environment. In order to validate the proposed evaluation model, the simulation of the parallel B&B algorithm on a MIN-based system is carried out at the same time. The results from both analysis and simulation match closely. It is also shown that the proposed Optimal Best-First search B&B algorithm performs better than other reported schemes with its various advantageous features such as: less subproblem evaluations, prefer load balancing, and limited scope of remote communication.

• Journal of KIISE:Information Networking
• /
• v.29 no.6
• /
• pp.696-705
• /
• 2002

This paper presents a new copy network for multicast ATM switches. Many studies have been carried out up to date since the proposition of Lee's copy network. However, the overflows and cell conflicts within the switch have still been raised a problem in argument. In order to reduce those problems, we proposed a 3-dimensional multicast switching architecture which has shared buffers in this paper. The proposed architecture can reduce the overflows and cell conflicts through multiple paths and output ports even in the high load environments. Also, we proposed a cell splitting algorithm which handles the cell in the case of large fan-out, and a copy network to increase throughput by expanding the Lee's Broadcast Banyan Network(BBN). Cell copy uses the Boolean interval splitting algorithm and the multicast pattern of the cells according to the self-routing characteristics of the network. In the proposed copy network, we improve the problems such as overflow, cell splitting of large fanout, cell conflicts, etc., which were still existed in the Lee's network. The results of performance evaluation by computer simulation show that the proposed scheme has better throughput, cell loss rate and cell delay than the conventional method.

• Journal of the Microelectronics and Packaging Society
• /
• v.24 no.2
• /
• pp.11-15
• /
• 2017

As the heat dissipation problem is increased in 3D multi flip chip packages, an improvement of thermal conductivity in bonding interfaces is required. In this study, the effect of alumina filler addition was investigated in non-conductive paste(NCP). The fine alumina filler having average particles size of 400 nm for the fine pitch interconnection was used. As the alumina filler content was increased from 0 to 60 wt%, the thermal conductivity of the cured product was increased up to 0.654 W/mK at 60 wt%. It was higher value than 0.501 W/mK which was reported for the same amount of silica. It was also found out that the addition of fine sized alumina filler resulted in the smaller decrease in thermal conductivity than the larger sized particles. The viscosity of NCP with alumina addition was increased sharply at the level of 40 wt%. It was due to the increase of the interaction between the filler particles according to the finer particle size. In order to achieve the appropriate viscosity and excellent thermal conductivity with fine alumina fillers, the highly efficient dispersion process was considered to be important.

• Journal of the Microelectronics and Packaging Society
• /
• v.26 no.2
• /
• pp.31-43
• /
• 2019

In this study, polymer elastic bumps were fabricated for the flexible electronic package flip chip bonding and the viscoelastic and viscoplastic behavior of the polymer elastic bumps according to the temperature and load were analyzed using FEM and experiments. The polymer elastic bump is easy to deform by the bonding load, and it is confirmed that the bump height flatness problem is easily compensated and the stress concentration on thin chip is reduced remarkably. We also develop a spiral cap type and spoke cap type polymer elastic bump of $200{\mu}m$ diameter to complement Au metal cap crack phenomenon caused by excessive deformation of polymer elastic bump. The proposed polymer elastic bumps could reduce stress of metal wiring during bump deformation compared to metal cap bump, which is completely covered with metal wiring because the metal wiring on these bumps is partially patterned and easily deformable pattern. The spoke cap bump shows the lowest stress concentration in the metal wiring while maintaining the low contact resistance because the contact area between bump and pad was wider than that of the spiral cap bump.

• The Journal of the Korea Contents Association
• /
• v.19 no.2
• /
• pp.516-524
• /
• 2019

The purpose of this study is to analyze the cases related to the multi-dimensional urban planning and its related systems that can contribute to the urban regeneration as the policies and projects for stereoscopic city increase. Through the case analysis, urban regeneration function and role of multi-dimensional urban planning are identified as connection of places, activation of local economy, expansion of infrastructure and supply of housing. In the institutional sector, private participation is hindered due to the ban on the establishment of the right to hold state property. In addition, it is difficult to utilize the three-dimensional urban space without land securing at a certain rate based on uniform installation standards of the two-dimensional land use plan, and the problem of insufficient interconnection between law and institution is derived. In conclusion, it should actively support and promote the promotion of the three-dimensional facility with the aim of diversifying the regional infrastructure structure and strengthening the urban function. In addition, development of stereoscopic and compound development should be promoted for old urban areas, and parking lots, underground shopping malls, parking lots, etc. should be installed using the subspaces of parks, schools, roads and traditional markets of old residential areas. Finally, cooperation between the central government, the municipalities and the private sector is necessary for the realization of these urban regeneration projects.

• KSCE Journal of Civil and Environmental Engineering Research
• /
• v.42 no.6
• /
• pp.879-885
• /
• 2022

Of increasing global popularity is the multi-dimensional use and development of cities to address land use and urban issues caused by high urban density and challenging topography. In Korea, the city of Busan has a large proportion of mountainous areas, and the Gyeongbu Line that runs through the city's center has been interrupting this urban area for over 117 years. Because a lack of usable land is hindering the development of the city, introducing a multi-dimensional approach to urban development is seen as important. Accordingly, the Gyeongbu Line underground project is attempting to solve the problem of disconnection of Busan's city center and increase the amount of usable land for varied multi-dimensional use. In this study, by conducting a preference survey among those who live near the underground project sites of the Gyeongbu Line stations in Busan, the planned use of each available land arearesulting from the multi-dimensional development of railroadsand railway stations was investigated. However, in order to further the results of the survey, legal and institutional support is needed. There are limits to the multi-dimensional use of land, such as the lack of interconnection between individual laws and the lack of specific guidelines for multi-dimensional development.