• Communications of the Korean Mathematical Society
• /
• v.13 no.3
• /
• pp.603-627
• /
• 1998

The leaky bucket scheme is a promising method that regulates input traffics for preventive congestion control. In the ATM network, the input traffics are bursty and transmitted at high-speed. In order to get the low loss probability for bursty input traffics, it is known that the leaky bucket scheme with static leaky rate requires larger data buffer and token pool size. This causes the increase of the mean waiting time for an input traffic to pass the policing function, which would be inappropriate for real time traffics such as voice and video. We present the leaky bucket scheme with dynamic leaky rate in which the token generation period changes according to buffer occupancy. In the leaky bucket scheme with dynamic leaky rate, the cell loss probability and the mean waiting time are reduced in comparison with the leaky bucket scheme with static leaky rate. We analyze the performance of the proposed leaky bucket scheme in discrete-time case by assuming arrival process to be Markov-modulated Bernoulli process (MMBP).

• Proceedings of the IEEK Conference
• /
• 1998.06a
• /
• pp.50-53
• /
• 1998

In this paper, the modified Usage Parameter Control(UPC) method based on Dual Leaky Bucket algorithm is proposed to improve the perfor mance of multimedia synchronization and to control burst traffic. In the proposed algorithm, Synchronous cells are by passed to the 2nd stage Leaky Bucket (LB) of the DLB. for overloaded traffic condition, the violated cells are saved in a temporary buffer and they are retransmitted when the 2nd stage bucket is empty.

• Journal of the Korea Institute of Information and Communication Engineering
• /
• v.16 no.5
• /
• pp.939-946
• /
• 2012

Recently privacy breaches has been an social issues. If we should encrypt the sensitive information in order to protect the database, the leakage of the personal sensitive data will be reduced for sure. In this paper, we analyzed the existing protection algorithms to protect the personal sensitive data and proposed the combined method using the bucket index method and the bloom filters. Bucket index method applied on tuples data encryption method is the most widely used algorithm. But this method has the disadvantages of the data exposure because of the bucket index value presented. So we proposed the combined data encryption method using bucket index and the bloom filter. Features of the proposed scheme are the improved search performance of data as well as the protection of the data exposure.

• Journal of Drive and Control
• /
• v.19 no.2
• /
• pp.11-16
• /
• 2022

It is important to measure the excavator's work productivity that estimates the bucket's payloads on a process. If the bucket isn't filled at every working cycle, the excavator's operator has to drive the machine more to achieve his work quota. If bucket is filled over with the load, the other way around, the transferred object has to spread out on the workplace. That causes additional work to clean the site. This paper proposes a method that can estimate the bucket's payload to improve the excavator's work productivity. This method assumes that the excavator is a lumped mass system. And it uses a 3 points angle (boom link, arm link, swing) and 2 points pressure (boom cylinder's input port and output port) of measurable data. Depending on assumptions, the bucket's payload can be calculated by the payload's motion equation. And this suggested method can be verified by simple experiments.

• IE interfaces
• /
• v.21 no.3
• /
• pp.333-342
• /
• 2008

Warehouses form an important link in a supply chain network. Among a variety of activities in warehouses, order picking is the process of retrieving a number of items out of storage to meet customer orders. Today, as the transactions through direct sales are wide spread, warehouses often receive a large amount of small orders to be handled within tight time windows, which makes fast and efficient order picking more important than ever. This paper examines a new order picking method where the concept of bucket brigade (BB) is applied. Bucket brigade is a way of dynamically coordinating workers who progressively perform a set of operations along a flow line. In bucket brigades, a worker is not assigned his jobs in a static way. Each worker takes a job from his predecessor when he is free. We identify some considerations when bucket brigades are applied to order picking activities. A new BB picking protocol is presented to improve existing BB picking protocols. Through simulation experiments, the performance of BB order picking is evaluated under various logistics environments.

• The Journal of Korean Institute of Communications and Information Sciences
• /
• v.22 no.5
• /
• pp.1116-1125
• /
• 1997

In this paper, the modified UPC(Usage Parameter Control) algorithm is proposed. The proposed UPC algorithm is based on Leakey Bucket algorithm and adds the characteristics of the jumping window algorithm for monitoring the average bit rate. The proposed algorithm let a cell, which is tagged by Leaky Bucket algorithm, pass through the network, if the network does not violate the average bit rate. The measuring method of window mechanism like jumping window. This paper supposes On/Off traffic source model of rthe performance evaluation and analysis of the proposed algorithm. Therefore, as simulation results, the proposed algorithm acquires more reduced results of the cell loss rate and bucket size than the Leaky Bucket algorithm.

• Journal of Digital Contents Society
• /
• v.8 no.4
• /
• pp.573-579
• /
• 2007

The Leaky Bucket mechanism has been studied in many areas. There has been much interest in flow control in High Speed Networks using the Leaky Bucket. In this paper, We propose the Burst Tokens Fill method that performs well in Leaky Bucket to control the average rate, peak rate, and burst size. This scheme show the improvement of performance. However, This method does not apply all area of applications. Especially application of on-off shape is appropriate and the other area must need to care for appling this scheme.

• Journal of the Korean Operations Research and Management Science Society
• /
• v.22 no.2
• /
• pp.45-65
• /
• 1997

We build a queueing model for buffered leaky bucket system. First, we set up system equations and them calculate the steady-state probabilities at an arbitrary time epoch by recursive method. We derive the mean waiting time and the mean number of cells in the input buffer, and evaluate the performance of the buffered leaky bucket system to find the optimal queue capacity and token generation rate that meet the quality of service(QoS).

• Journal of Environmental Science International
• /
• v.13 no.7
• /
• pp.637-643
• /
• 2004

A new method of automatic recording raingauge is developed to measure rainfall with 0.01mm resolution. This use two different signals to measure rainfall more accurately compare than other raingauges. One is weight of the tipping bucket with rainfall amount and the other is pulse from tipping bucket reverse. New method applied 1 mm tipping bucket mechanism and install loadcell under tipping bucket mechanism for measuring rainfall weight. Loadcell measure weight of rainfall until 1 mm with 0.01 mm resolution and more than 1 mm than bucket reverse and pulse signal generate, after that loadcell measure weight again. The validation of new instrument was examined in the room 65 mm/hour rainfall rate total 53 mm range. There is below than 1 % error of absolute rainfall amount and 0.01 mm resolution. The field test of instrument was carried out by comparing its measured values with values recorded by weight type and standard type on June 1 2003 at Terrestrial Environmental Research Center at Tsukuba University in Tsukuba of Japan, when it has recorded total amount of 40.58 mm rainfall by standard raingauge and new raingauge recorded 41.032 mm. Same rainfall intensity pattern observed in field observation with weight type raingauge. Rainfall intensity between weight type and Lee-A type raingauge reached 0.9947 correlation in 3 minute average.

• Proceedings of the KIEE Conference
• /
• 2005.07d
• /
• pp.2507-2509
• /
• 2005

Because the rain gauges of tipping bucket type can easily use the digital signal, the rain gauges are widely used for the meteorological observation. In general, the resolution of rain gauges of tipping bucket type can be categorized by the 0.1mm, 0.5mm, and 1.0mm classes. But, the error of the tipping bucket rain gauges is made by the intensity of rainfalls and is expected to make the standard calibration method for error measurement. Thus, we developed the hardware of standard calibration facility for rain gauges by weighting measurement method and proposed the standard procedure by rainfall intensity in this study. Also, we calculated the error for the rainfall intensity and obtained useful result through the proposed calibration method.