• IEMEK Journal of Embedded Systems and Applications
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• v.5 no.4
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• pp.243-253
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• 2010

Multihop data delivery in vehicular ad hoc networks (VANETs) suffers from the fact that vehicles are highly mobile and inter-vehicle links are frequently disconnected. In such networks, for efficient multihop routing of road safety information (e.g. road accident and emergency message) to the area of interest, reliable communication and fast delivery with minimum delay are mandatory. In this paper, we propose a multihop vehicle-to-infrastructure routing protocol named Vertex-Based Predictive Greedy Routing (VPGR), which predicts a sequence of valid vertices (or junctions) from a source vehicle to fixed infrastructure (or a roadside unit) in the area of interest and, then, forwards data to the fixed infrastructure through the sequence of vertices in urban environments. The well known predictive directional greedy routing mechanism is used for data forwarding phase in VPGR. The proposed VPGR leverages the geographic position, velocity, direction and acceleration of vehicles for both the calculation of a sequence of valid vertices and the predictive directional greedy routing. Simulation results show significant performance improvement compared to conventional routing protocols in terms of packet delivery ratio, end-to-end delay and routing overhead.

• Journal of the Korean housing association
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• v.22 no.1
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• pp.85-93
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• 2011

As passing through the Japanese colonial period, Daegu has been changed into a modern city. In addition, the nature of the city had changed a lot by withdrawal of Eup-sung and the opening of the road and the increase of population in Japan. Of course, the expansion of the city was caused by the increase of the Japanese population. To understand the current city, it is most important to understand the past city's characteristics and especially the formation and change of city must be considered with understanding the situation of city. And now the city reflects the role of the city in the past. In fact, the effect of the street constitution in Daegu Eup-sung during Japanese colonial period on the present time was very big and continues. Especially, in order to understand the situation of the city and consider the direction in the future, the analysis of the development process has important implications.This study aimed to consider the change of Daegu Eup-sung Street and Formation of Dwelling Site focusing on the Buksung Street. The purpose of this study is to investigate the nature of the city and changing process of the city by the past Buksung street and the current Buksung street as time goes by.

• KIEAE Journal
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• v.9 no.2
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• pp.81-90
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• 2009

Relating to grasping sequential landscape characteristics in consideration of the behavioral characteristics of the subject experiencing visual perception, this study was made on the subject of main walking line section for visitors of three treasures of Buddhist temples. Especially, as a method of obtaining data for grasping sequential visual perception landscape, the researcher employed [momentum sequential viewpoint setup] according to [the interval of pointers arbitrarily] and fisheye-lens-camera photography using the obtained omni-directional angle visual perception information. As a result, in terms of viewpoint selection, factors like approach road form, change in circulation axis, change in the ground surface level, appearance of objects, etc. were verified to make effect, and among these, approach road form and circulation axis change turned out to be the greatest influences. In addition, as a result of reviewing the effectiveness via the subjects, for the sake of qualitative evaluation of landscape components using the VR picture image obtained in the process of acquiring omni-directional angle visual perception information, a positive result over certain values was earned in terms of panoramic vision, scene reproduction, three-dimensional perspective, etc. This convinces us of the possibility to activate the qualitative evaluation of omni-directional angle picture information and the study of landscape through it henceforth.

• Journal of the Ergonomics Society of Korea
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• v.28 no.2
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• pp.9-16
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• 2009

The aim of this study was to evaluate the effects of the driving performance and workload according to changing driving environment and types of steering wheel. Twelve drivers who participated in this study consisted of two groups; six Japanese as the left-lane drivers who was accustomed to driving on left-hand side of the road, and six Europeans, Americans, and Korean as the right-lane drivers who was accustomed to driving on right-hand side of the road. They were asked to operate a driving simulator while using two different types of steering wheel (for the left-hand side driving and the right-hand side driving). During the experiment, a range of data were measured including driving performance, mental workload, and eye movements which were recorded in order to identify the amount of time looking towards the in-vehicle route guidance. Results indicated that the use of the steering wheel by parallel moving led to increase high attentional demand and worse glance behavior to traffic signs for the left-lane drivers. In the case of the right-lane drivers, the effects by changing driving direction were more effective than the types of steering wheel due to their habit or traits.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2004.04b
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• pp.195-198
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• 2004

In this paper, the disk-type piezoelectric transformer for the high power was investigated with the variation of road resistance. The diameter and thickness of a disk-type piezoelectric transformer was 50mm and 4.5mm, respectively. The piezoelectric transformer was composed to PZT-PMN-PSN. The ratio of driving electrode and generating electrode ranges from 1.4:1 to 3:1. The poling direction of driving part and generating part are the same. A voltage step-up ratio increased with increasing the load resistance, $R_L$, so it reached 60 times under no road resistance. also, the maximum efficiency of 97% was obtained.

• Transactions of the Korean Society of Automotive Engineers
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• v.21 no.1
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• pp.1-8
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• 2013

Recently, the automotive technology has developed with electronics and information technology as convergence technology while vehicles had been regarded as machines. Moreover, vehicles are becoming more intelligent and safer devices, assembly of advanced technologies by customers' demand. Even though all of installations of vehicle have attracted as diverting devices, it cause drivers' mistakes like delay of response on traffic condition. Here, we proposed the Field Operational Test (FOT) environment which could be used as driving and road conditions collector(Vehicle motion, Traffic condition, Driver input, Driver state, etc.) for researches about Driver Friendly Intelligent System(SCC, LDWS, etc.), Human Vehicle Interface(Driving Workload, etc.) and Economic Drive Model. Furthermore driving patten and fuel consumption patten of drivers were analyzed by measured data and direction of future research was suggested.

• Journal of Sensor Science and Technology
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• v.21 no.3
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• pp.198-203
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• 2012

In this paper, the driving information system of the bicycle has been studied by using the 3-axis acceleration sensor. The sensor module composed of 3-axis acceleration sensor and MCU(Microcontroller Unit) was mounted onto the handle of bicycle and the experiments were conducted on the flatland, uphill and downhill of bicycle road. Three axis acceleration values were converted to the pitch and roll angles, then four major compensation methods have been applied to achieve meaningful data for driving information system. The experimental results of pitch angles showed 2.46, -1.26, 7.79 degrees in case of flatland, uphill, downhill, respectively. When the steering handle turned to the left direction, roll angles showed -29.35, -41.67, -36.98 degrees at each road condition. With the right-turn, roll angles presented 20.05, 33.75, 24.44 degrees in case of flatland, uphill, and downhill, respectively. The pitch angle has been increased more than 40 degrees at stop mode. By using the change of pitch and roll angles, we could obtain the driving information system of bicycle successfully.

• 한국방재학회:학술대회논문집
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• 2008.02a
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• pp.329-332
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• 2008

This study presents a viscoelastic characterization of flexible pavement subjected to moving loads. A series of field tests have been conducted on three pavement sections (A2, A5, and A8) at the Korea Expressway Corporation (KEC) test road. The effect of vehicle speed on the responses of each test section was investigated at three speeds: 25km/hr, 50km/hr, and 80km/hr. During the test, both longitudinal and lateral strains were measured at the bottom of asphalt layers and in-situ measurements were compared with the results of finite element (FE) analyses. A commercial FE package was used to model each test section and a step loading approximation has been adopted to simulate the effect a moving vehicle. Field responses reveal the strain anisotropy (i.e., discrepancy between longitudinal and lateral strains) and the amplitude of strain normally decreases as the vehicle speed increases. In most cases, lateral strain was smaller than the longitudinal strain, and strain reduction was more significant in lateral direction.

• Journal of Korean Society of Transportation
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• v.27 no.5
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• pp.163-168
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• 2009

Travel time reduction is a benefit in economic analysis. Freight transportation time reduction benefits influence the logistics industry. The objectives of this paper are to estimate the Value of Time (VOT) for transportation time reduction with logit methodology. The data of Gyeonggi-do's domestic road freight transport in 2007 are used. VOT was estimated for five commodities. An average VOT of 19,946 won/vehicle-hr was calculated; transport of electronic parts had the highest VOT. This study will help provide direction for improving Korea's road infrastructure for freight.

• Journal of the Korean Society of Mineral and Energy Resources Engineers
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• v.55 no.6
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• pp.538-545
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• 2018

It is necessary to develop systematic mine reclamation technology according to mid- and long-term road maps to effectively promote mine reclamation projects. Evaluating the main achievements of the mine reclamation technology according to the first and second-stage roadmaps revealed the necessity of sharing the R&D achievements. In this study, by reviewing the key issues of the third-stage roadmap and considering the major technical needs of in-and-out customers, the strategic development direction of sustainable mine reclamation technology through expanded sharing of R&D achievement was examined.