• JSTS:Journal of Semiconductor Technology and Science
• /
• v.12 no.4
• /
• pp.433-448
• /
• 2012

A source-synchronous receiver based on a delay-locked loop is presented. It employs a shared global calibration control between channels, yet achieves channel expandability for high aggregate I/O bandwidth. The global calibration control accomplishes skew calibration, equalizer adaptation, and phase lock of all the channels in a calibration period, resulting in the reduced hardware overhead and area of each data lane. In addition, the weight-adjusted dual-interpolating delay cell, which is used in the multiphase DLL, guarantees sufficient phase linearity without using dummy delay cells, while offering a high-frequency operation. The proposed receiver is designed in the 90-nm CMOS technology, and achieves error-free eye openings of more than 0.5 UI across 9-28 inch Nelco4000-6 microstrips at 4-7 Gb/s and more than 0.42 UI at data rates of up to 9 Gb/s. The data lane occupies only $0.152mm^2$ and consumes 69.8 mW, while the rest of the receiver occupies $0.297mm^2$ and consumes 56.0 mW at the 7- Gb/s data-rate and supply voltage of 1.35 V.

• The Journal of The Korea Institute of Intelligent Transport Systems
• /
• v.15 no.6
• /
• pp.62-70
• /
• 2016

Increased bus traffic leads inefficiency at near-side bus stops in median exclusive bus lane because buses are waiting for a signal does not have a vehicle arrived. This study suggests a method for estimating a proper spacing between bus stops and signalized intersection to prevent the inefficiency. We modified the Poisson model for a proper spacing by using both dwell time and waiting time of signal instead of using dwell time only. The waiting time of signal changes by spacing and it was measured using micro simulation program. The iterative algorithm using the change of waiting time of signal was also suggested. By applying the proposed method, measure waiting time by simulation and iterative algorithm, the spacing of near-side bus stops, proper spacing is suggested according to flow rate level.

• KDI Journal of Economic Policy
• /
• v.28 no.2
• /
• pp.179-198
• /
• 2006

This paper estimates relationships between the supply of national highways, measured in lane-km, and the quantity of traffic, measured in vehicle-km traveled. The analysis uses a panel data set of annual observations for the years 1984 to 2003. By using a log-linear lag effect model designed to capture short and long term effects, the paper estimates that national highway vehicle-km traveled has a lane-km elasticity of 0.268 at the country level (Non-Seoul Metropolitan area) and 0.41 at the Seoul metropolitan area for the short term. For the long term, the paper estimates 0.8 for the country level and 1.23 for the Seoul metropolitan area. This paper finds conclusive evidence that increases in highway lane-miles have generated traffic over the period of study, however the increasing ratio of the generated traffic decreases gradually, particularly during the late 1980s.

• International Journal of Highway Engineering
• /
• v.11 no.2
• /
• pp.175-184
• /
• 2009

The study analyzes likely impacts of left truck lane restriction strategies on urban freeways based on a traffic simulation model. This study contains two main parts. The first part is performed to develop feasible alternatives as well as provide insights into conditions under left truck lane restrictions would be effective based on the analysis of two representative hypothetical highways. Different levels of O-D demands and truck percentage is at least restrictions would work when maximum rate of flow is more than 1,300vphpl or truck percentage is at least over loft of the total traffic. The second part of our study concerns a case study on a region with perhaps the highest truck volumes in the U.S. - a northbound section of Interstate 710 corridor in Los Angeles County, Southern California. The results show that restricting the two leftmost lanes under congested traffic with heavy ruck use, provides the most positive impacts in terms of improving the flow of traffic and saving fuel. In addition, our study demonstrates that in general, the number of lanes restricted is a crucial factor in the success of this strategy.

• Development and Reproduction
• /
• v.17 no.3
• /
• pp.199-205
• /
• 2013

Genomic DNAs were extracted from the turtle leg (Pollicipes mitella, 1798) population of Tongyeong, Yeosu and Manjaedo located in the southern sea of Korea. The turtle leg population from Tongyeong (0.929) exhibited higher bandsharing values than did turtle leg from Manjaedo (0.852). The higher fragment sizes (>1,200 bp) are much more observed in the Yeosu population. The number of unique loci to each population and number of shared loci by the three populations, generated by PCR using 7 primers in the turtle leg (P. mitella) population of Tongyeong, Yeosu and Manjaedo. Genetic distances among different individuals of the Tongyeong population of the turtle leg (lane 1-07), Yeosu population of the turtle leg (lane 08-14) and Manjaedo population of the turtle leg (lane 15-21), respectively, were generated using the CLASSIFICATION option in Systat version 10 according to the bandsharing values and similarity matrix. The dendrogram, obtained by the seven decamer primers, indicated three genetic clusters: cluster 1 (TONGYEONG 01 TONGYEONG 07), cluster 2 (YEOSU 08 YEOSU 14), and cluster 3 (MANJEDO 15 MANJEDO 21). Tongyeong population could be evidently discriminated with the other two Yeosu and Manjaedo populations among three populations. The longest genetic distance (0.305) was found to exist between individuals' no. 02 of the Tongyeong population and no. 13 of the Yeosu population. It seems to the authors that this is a result of a high degree of inbreeding in narrow region for a long while.

• Journal of Korean Society of Transportation
• /
• v.20 no.2
• /
• pp.93-104
• /
• 2002

The purpose of this study was to develop a improved high-order continuum model among macroscopic traffic flow models. This study was mainly performed for uninterrupted flow. In the first step, the proposed model described traffic flow at dropped lane. (no exits) It was possible to describe the traffic flow during short-term considering lane change. The proposed model was based on Payne's model. Our model was newly applied to uninterrupted traffic flow in consideration of geometry condition and driver behavior. It is possible to establish efficient control strategies, simulation and assess the effects of geometric improvements using this model. This model was simulated with field data for the actual adaption. The results of the model tests, traffic volume and density is suitably represented. we think that the results in the article can be led to predicting the situation in the near future.

• Journal of Korean Society of Transportation
• /
• v.26 no.1
• /
• pp.15-24
• /
• 2008

Located in the middle of lanes, the station of a median exclusive bus lane generates pedestrian groups on the green light of a crosswalk and causes pedestrians delays passing the access section. For the purpose of showing these facts, the pedestrian analysis, on which the queuing theory is applied, is presented in this study. The Result is that the pedestrian environment was deteriorated (LOS D) compared to an exciting pedestrian analysis based on 15 minutes of pedestrian volume (LOS A). A pedestrian level of service has been reevaluated based on an arrival rate on the median bus station in order to examine whether the result reflects reality or not. In result, it was similar outcomes to this study.

• Journal of Korean Society of Transportation
• /
• v.28 no.6
• /
• pp.85-97
• /
• 2010

The present study aims at estimating the model of bus bunching duration along with its influential determinants in an attempt to understand the status of bus bunching being created by buses from various routes converging into one bus stop. To do so, the duration analysis, a well-known survival analysis, was adopted in order to capture the distribution of duration time as for 8 base lines, accordingly developing the model best fit for weibull distribution. Key attention to draw out the duration time model for bus bunching phenomena was laid, by analyzing 18 impact factors, on such criterion variables as number of berth, number of bus line in each berth and maximum capacity of on-and-off passengers in each line. Comparison in two typical types of bus lane was made between bus-only center lane(Dobong Mia-ro) and normal street-side lane(Tongil Euiju-ro). In this regard, the study, based on the model as above, suggested appropriate alternatives to improve the bus operation by effectively controlling bus bunching.

• Journal of Korean Society of Transportation
• /
• v.22 no.4 s.75
• /
• pp.43-56
• /
• 2004

The KHCM procedure is a micro level analysis at signalized intersections requiring a lot of input variables and complex computations. The research was to investigate the possibility of simplifying the analysis procedures by using the generalized or the combined variables that less influence on the adjusted traffic volume and through-car equivalents of left or right turns. It was also tried to make lane grouping into directional flow ratio(v/s) based on a field surveys. The maximum and minimum values of each variables were compared with each other through the KHCM analysis procedures in terms of control delay. The lane grouping and the synthetical influence of a simplified method was evaluated with the scenario built in prevailing maximum and minimum conditions. The study showed that the control delay was not significantly sensitive to the selected variables and the lane grouping and their synthetical influence as well.

• Journal of the Korean Society of Fisheries and Ocean Technology
• /
• v.47 no.4
• /
• pp.428-434
• /
• 2011

To establish a vessel safety management system for improving the safety of vessel's traffic and preventing vessel's traffic accidents, the state of marine traffic in the Busan South Port was investigated and analyzed as preliminary survey of the countermeasures. As a result of the study, there are 1,158 vessels in a day, 48 vessels in an hour, and the maximum traffic is about 118 vessels between 16:00 and 17:00 hours everyday, which requires to establish and operate a traffic control system necessarily for ensuring vessel's traffic safety. Furthermore, passages of tanker, passenger ship, cargo vessel and government vessel showed to sail along main traffic lane to be obtained enough sea depth at the survey area. However, passages of fishing vessel and launch showed to sail freely at all survey area owing to outstanding maneuverability and a shallow draft. Some vessels of launch sailed along main traffic lane, but other vessels crossed to sail it. The passages to cross main traffic lane is higher the risk of collision. Therefore, safety measures are urgently needed for the operation of the Busan South Port management system and the prevention of marine pollution.