• The KIPS Transactions:PartC
• /
• v.10C no.3
• /
• pp.305-310
• /
• 2003

The performance of various GFR implementations has been recently studied due to the interest to provide bandwidth guarantees with a simpler implementation than ABR in ATM networks. One of the important factors is buffer management for guaranteeing QoS in GFR service. An efficient buffer management algorithm is necessary to guarantee MCR for untagged cell in ATM switch. In this paper, we propose and evaluate a buffer management scheme to provide the GFR service guarantees. The proposed scheme can control the cell discarding for fairness in each VC, and compared with Double-EPD and DFBA. Our results show that the proposed buffer management with per-VC queuing achieves significant enhancement on goodputs and fairness index than those of existing methods.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
• /
• 2001.07a
• /
• pp.174-177
• /
• 2001

We have seen the effects of buffer layer in organic light-emitting diodes using poly(N-vinylcarbazole)(PVK). Polymer PVK buffer layer was made using spin casting techniques. Two different types of spin casting have been applied; static coating and dynamic coating. Two device structures were fabricated; one is ITO/TPD/Alq$_3$/Al as a reference, and the other is ITO/PVK/TPD/Alq$_3$/Al to see the effects of buffer layer in organic light-emitting diodes. Current-voltage characteristics and luminous efficiency were measured with a variation of spin-casting methods and rpm speeds. We have obtained an improvement of luminous efficiency by a factor of two and half when the PVK buffer layer is used.

• Journal of the Korean Institute of Telematics and Electronics D
• /
• v.35D no.6
• /
• pp.28-36
• /
• 1998

We have proposed a new non-inverting SOI buffer circuit for the high speed operation at low supply voltage. The body biases of main MOS devices in the proposed circuit are controlled dynamically via subsidiary MOS device connected efficiently to the body terminal. We showed current derivability of the body controlled devices obtained by device simulation and compared with that of conventional SOI devices. Delay time characteristics of the buffer circuit were analyzed by SPICE simulation and compared with those of conventional SOI CMOS buffer circuits. Delay time reduction of the SOI buffer over conventional SOI CMOS buffer with same area is about 36 % at $V_{S}$=1.2 V and $C_{L}$=2 pF. pF.

• Journal of the Korean Institute of Telematics and Electronics
• /
• v.20 no.3
• /
• pp.61-68
• /
• 1983

In this paper various aspects of statistical maltiplexing of data signs have been investigated. A queueing model with finite waiting room and batch poisson arrivals is studied assuming that data signals are transmitted at a constant rate. Using traffic intensity and average burst length as parameters, overflow probabilities and expected queueing delay due to buffering are obtained. Also, a real system model of a statistical multiplexer that can be directly used in micro-programmed hardware realization is proposed. To examine the performance of the system, computer simulation has been done at various conditions. The results obtained can be used in designing a buffer efficiently.

• The KIPS Transactions:PartA
• /
• v.9A no.2
• /
• pp.137-146
• /
• 2002

In VOD server, in order to guarantee playback of continuous media, such as video, without hiccups for multiusers, the server has to manage its buffer sophisticatedly by prefeching a part of the data into the buffer As the continuous media data buffered by one user can be used again by the others, the number of disk accesses is reduced and then the latency time far the users is also reduced. In this paper, we propose a new buffer management technique for continuous media in VOD server. Our basic algorithm partitions the buffer into groups and then a group of buffer which has the lowest utilization is chosen and partitioned again for a new user. The basic algorithm is extended for supporting multiple streams and clip data and for providing VCR functions. Our proposed technique is able to increase in the number of concurrent users as increasing the utilization of the buffer and to minimize the average waiting time for multiuser accesses as the bandwidth of storage is slowly reached to the limit. In the simulation study for comparing the performance of our technique with that of the existing techniques, we show that the average waiting time is reduced mere than 50% and the number of concurrent users increases by 1 ∼5% as compared with those of the exiting techniques.

• Journal of the Institute of Electronics Engineers of Korea TC
• /
• v.40 no.10
• /
• pp.8-15
• /
• 2003

In this paper, we address how to provide absolute differentiated services for optical burst switching (OBS) networks based on dynamic wavelength assignment. Unlike existing quality of service (QoS), such as buffer-based and offset-time based scheme, our proposed dynamicvirtual lambda partitioning (DVLP) scheme does not mandate any buffer or extra offset time, but can achieve absolute service differentiation between classes. This new DVLP scheme shares wavelength resources based on several different priority of classes in an efficient and QoS guaranteed manner. The performance results show that the proposed scheme effectively guarantees a target blocking probability of each traffic classes both in Poisson and Self-similar traffic environment.

• The Journal of Korean Institute of Communications and Information Sciences
• /
• v.36 no.9B
• /
• pp.1082-1091
• /
• 2011

Power-reduction techniques based on DVFS(Dynamic Voltage and Frequency Scaling) are crucial for lengthening operating times of battery powered mobile systems. This paper proposes an optimal DVFS scheduling algorithm for decoders with memory size limitation on display buffer, which is realistic constraints not properly touched in the previous works. Furthermore, we mathematically prove that the proposed algorithm is optimal in the limited display buffer and limited clock frequency model, and also can be used for feasibility check. Simulation results show the proposed algorithm outperformed the previous heuristic algorithms by 7% in average, and the performance of all algorithms using display buffers saturates at about 10 frame size.

• KDI Journal of Economic Policy
• /
• v.28 no.1
• /
• pp.117-144
• /
• 2006

This study is to analyze the existence of the real buffer effect that reflects the effect of beginning-of-period inventory stocks effect on the demand for fixed investment, and the financial buffer effect indicates the substitution effect between end-of-period inventory stock and the source of financing for fixed investment. I use panel data of 361 Korean listed non-financial firms during 1990-2003. After the crisis, it also observed whether the relationship between inventory stocks and fixed investment has altered or not. I review the theoretical connection between inventory stock and fixed investment through the paper by Bo(2004) and estimate the investment model by the method of GMM-SYS. The results show negative relation between end-of-period inventory stock and fixed investment in the whole period and each period classified, also it confirms that the relation between fixed investment and end-of-period investment is significantly negative. It can be interpreted through two aspects that firms not only use inventory stock as a buffer in response to unexpectedly high demand, but also utilize inventory stock as a source of financing for fixed investment. The results imply that firm's decision-making is much correlated with production-and-inventory stock adjustment, decision-making about fixed investment, and decision-making about financial affairs.

• Journal of the Institute of Electronics Engineers of Korea TC
• /
• v.38 no.8
• /
• pp.30-41
• /
• 2001

In this paper, the architecture of Dynamic GSMP V3(General Switch Management Protocol Version 3), an open interface protocol with resource management functions for efficient IP service on ATM over MPLS, is proposed and implemented in hardware. And we compare and analyze the proposed GSMP with the GSMP under standardization process in terms of CLR (Cell Loss Rate). We design the Slave block of the Dynamic GSMP V3 using SAM-SUNG SoG $0.5{\mu}m$ process, which performs functions for switch connection control in the ATM Switch. In order to compare difference performanaces between the proposed method and the conventional one, we conducts simulations using the minimum buffer search algorithm with random cell generation. The exponential results show that the proposed method leads to performance enhancement in CLR.

• KDI Journal of Economic Policy
• /
• v.34 no.4
• /
• pp.69-90
• /
• 2012

This paper explores the effect of the countercyclical capital buffer using a DSGE (Dynamic Stochastic General Equilibrium) model with a banking sector. The main results are following. First, if the CAR (capital asset ratio) rises by 1%p as the countercyclical capital buffer, output and credit would increase less than otherwise by 0.8%p and 1.2%p, respectively. Second, the countercyclical capital buffer would decrease both credit and debt of banks, or deposit, and, as a result, boost the CAR. However, if we are going to use monetary policy to control credit expansion by allowing the interest rate to respond to credit, bank capital would also diminish, which would cause the CAR to be lower.