• The Journal of Korean Institute of Communications and Information Sciences
• /
• v.39B no.9
• /
• pp.578-589
• /
• 2014

In this paper, we introduce the concept of cyber-physical intersection systems (CPIS) which interconnects roadside units (RSU) located at the intersection, on-board units (OBU) of moving vehicles, and the smartphone apps, named the Smartphone Agent (SA). At the pedestrian mode of the SA, the connectivity management schemes, such as a location update and a handover control algorithm, are proposed to better support the CPIS services while minimizing the power consumption of the pedestrian's smartphone. We develop a real prototype of the CPIS, including RSU, OBU, and the SA. Based on the numerical results collected from a pedestrian moving around the Pusan National University campus, we validate that the proposed connectivity management schemes can improve not only the power efficiency of the pedestrian's smartphone, but also the quality of the CPIS services.

• The Journal of Korean Institute of Communications and Information Sciences
• /
• v.39B no.8
• /
• pp.544-554
• /
• 2014

In this paper, we introduce a cyber-physical intersection systems (CPIS) which intimately interconnects roadside units (RSU) located at intersection, on-board units (OBU) of moving vehicles, and smartphone apps. Based on the architecture of CPIS, we also present a green light optimal speed advisory based on the reference mobility models (GLOSA-RMM) to reduce intersection stopping time (IST) and fuel consumption. Based on several reference mobility models, the GLOSA-RMM determines the appropriate speed advisory by taking into account the current mobility and the intersection traffic light status, and then provides screen/voice GLOSA instructions to minimize the driver's distraction. We show that the GLOSA-RMM can reduce both the IST and the fuel consumption through the numerical results obtained from the prototype of the CPIS consisting of the OBU, the RSU and the smartphone app.

• Journal of the Korean Society of Environmental Restoration Technology
• /
• v.1 no.1
• /
• pp.141-150
• /
• 1998

This study was conducted to find out the possibility of seeding of Zoysia japonica and woody plants for the revegetation of rock-exposed-cutslopes by Natural Topsoil Restoration Methods (NTRM). The 5cm thick layer of artificial soil was attached at rock-exposed cutslopes for the growth of Zoysia japonica and native woody plants by NTRM. The main results were summarized as follows. 1. Artificial soil attached at rock-exposed-slopes by NTRM was not eroded until recovered by Zoysia japonica and native woody plants. It shows extremely low soil erodibility. 2. One year later after seeding, woody plants show 100% ground coverage. But, in early stage, they grew more quickly at northwest slopes than at southeast slopes. 3. In seeding of Zoysia japonica, it grew more quickly at southeast slopes than at northwest slopes. Also, it grew better at lower part of the slopes than at middle part of the slopes. 4. After one year from seeding, the height of Lespedeza cyrtobotrya and Indigo/era pseudo-tinctoria were longer than any other plants. The next were Albizzia julibrissin, Lespedeza cuneata and wild flowers. The tree height of Rhus chinensis shows 28cm length, so it has enough possibility to be used for roadside revegetation works. 5. Lespedeza cyrtobotrya and Indigo/era pseudo-tinctoria show different importance values according to slope aspect. But, they show tendency to outweigh the other plants at all slope-aspects. 6. Most of the plants seeded by NTRM were germinated well and they covered rock-exposed-slopes so quickly and effectively. Thus it leads to conclusion that the revegetation methods used in this experiment was a very effective methods to recover rock-exposed-slopes by seeding of zoysia japonica and native woody plants.

• Journal of the Korean Institute of Landscape Architecture
• /
• v.22 no.1
• /
• pp.53-63
• /
• 1994

There are lots of forests around the Korean rural village. This study was conducted to investigate the state of the forests by the 15 forests case study of the Kamgok region in Chon-guk-Do province, Korea. The results are as follows. 1. The forests lose mostly original form by the construction of road and forest clearing for the land development business. And almostly the form of the forests is a trapezoid or roundness. 2. The forests were remained on account of the Korean cemetery customs which is burying underground. 3. The conservation of the forests becomes more difficult because of the continuous development pressure. 4. Because the scale of the forests is so small, they aren't named as the natural resort forest by the forest law. So it will be the better alternative that they are conserved and used by inducing the concept of the village resort forest. 5. Because the owenership of the forests exists in a person or a family, the forests will be destructed continuously by the cemetery development. 6. The vegetation of the upper trees in the forests is the simple forests of Pinus densiflora, Pinus rigida and bamboo. The height of upper tree is average 10-12m. And average root diameter is 13-29cm. The age of the tree is average 50 years old. The state of the forests is mostly fine. 7. It is clarified that the price of the forest land is 3-5 times expensive than the other cultivated land. 8. The forests were made by the forefathers for the purpose of the practical use and were reforested in the era 1960s, 1970s.

• Journal of the Korea Institute of Information and Communication Engineering
• /
• v.19 no.2
• /
• pp.393-400
• /
• 2015

As the development and distribution of the intelligent transport system is spreading recently and some of the services are commercialized through a pilot project, interest in DSRC with high utilization is increasing and antennas for roadside and on board equipment are being studied. A single patch was used for a vehicle antenna due to the requests of miniaturization of size, but there was performance degradation in most cases due to miniaturization. In addition, some methods to improve performance have been used in the antennas that were previously researched using the arrays, but they have the disadvantages of bulkiness in size of the antennas when using the arrays. Therefore, in this paper, the CPW fed microstrip patch antenna with the simple structure of being compact and easy to produce, which can be used in the OBU of DSRC, was designed.

• Economic and Environmental Geology
• /
• v.32 no.6
• /
• pp.633-644
• /
• 1999

Gully pot is a part of urban darainage system to butter the runoff water fluxes from road to rivers and to minimize environmental pollution by prevending over the surrounding area. A series of studies have been carried out concerning the physicochemical characteristics of the sewage sludge sediments sttling down in such a gully pot in order to over to evaluate the contamination for heavy metals such as pb, Zn, Cu and Cd. The roadside soil and sewage sludge samples from gully pots were characterized by XRD analyses and sequential extraction : Zn 2595.7$\mu$g/g; Cd9.8$\mu$/g; Cu602.5$\mu$g/g; Pb260.0$\mu$g/g),because of a long-term accumulation of vehicle- and industrial-related pollutants. Mean Zn concentration in Yeouido (3873$\mu$g/g) and Junggu(3262$\mu$g/g)areas are 4-5 times higher than those in Dobonggu area, suggesting that Zn may be derived from automobile traffic (including the rubber of automobile tires). The mean concentrations of Cu and Cr are very significantly high in Junggu and Gurogu areas, possibly due to the industrial activities in these areas. The low Pb levels throughtotut the whole study areas in Seoul can be accounted for the use of unleaded gasoline since 1987. Sequential extraction experiments illustrate that a major part of Zn is bound to FII and FIII, representing about 88% of the total Zn concentration. Fraction IV, related to orgnic matter, is mostly significant for Cu accounting for 60% of the total Cu, and FII is next in importance. The main carriers of Pb are the fractions III, II and FIV, and in that order. The behavior of Cd is quite different from other elements (Zn, Cu, Pb), and most of the Cd is associated with FV. Changes in the physicochemical environments (such as acidification) may result in severe environmental pollution of surface water and rivers with respect to heavy metals (especially Zn and Cu).

• Journal of the Korea Academia-Industrial cooperation Society
• /
• v.12 no.11
• /
• pp.5135-5142
• /
• 2011

A flexible mechanism is proposed in this paper to improve the dynamic response performance of a traffic flow control system in an urban area. The roads, vehicles, and traffic control systems are all modeled as intelligent systems, wherein a wireless communication network is used as the medium of communication between the vehicles and the roads. The necessary sensor networks are installed in the roads and on the roadside upon which reinforcement learning is adopted as the core algorithm for this mechanism. A traffic policy can be planned online according to the updated situations on the roads, based on all the information from the vehicles and the roads. This improves the flexibility of traffic flow and offers a much more efficient use of the roads over a traditional traffic control system. The optimum intersection signals can be learned automatically online. An intersection control system is studied as an example of the mechanism using Q-learning based algorithm, and simulation results showed that the proposed mechanism can improve the traffic efficiency and the waiting time at the signal light by more than 30% in various conditions compare to the traditional signaling system.

• Journal of Korean Society of Forest Science
• /
• v.7 no.1
• /
• pp.35-39
• /
• 1968

1. The Fall webworm, Hyphantria cunea was widely distributed ranging from Seoul to Kangnung, Yung-ju, Taegu, Iri and Kwang-ju in 1967. 2. Heavily infested tree species by the Fall webworm were Sycamore, Cherry, ash-leaved maple, poplar, and elm. 3. The average number of larval masses per damaged garden tree and roadside tree was 7.0 and 3.4 respectively. 4. Trees of 6-10m in height had most number of larval masses and were most heavily infested. 5. More larval masses were found in the median and lower parts than higher parts of the crown. 6. The ratio of damaged by second generation was 55% higher than by first generation. The ratio of damage by 3rd generation is 18% less than by first generation.

• The Journal of The Korea Institute of Intelligent Transport Systems
• /
• v.11 no.4
• /
• pp.34-50
• /
• 2012

This study set out to define a communication environment between an ITS center and field device required to be introduced in the nation in order to guarantee the interoperability, compatibility, and global competitiveness of communication between them in the nation. It also aimed to establish technical and policy plans for its introduction, develop an emulator for information exchange, and apply VMS by way of showing an example, thus testing its validity. First, a standard environment for information exchange between an ITS center and field device required to be introduced in the nation was defined as a dual protocol between DATEX and SNMP. The study also proposed a message definition system including meta-attribution definition and OID introduction. The study then suggested technical and policy plans for its introduction including securing enough feasibility with feedback through a model project of standard introduction, offering education and promotions for the standard in advance, providing methods to introduce and systematically manage OID, developing a hardware standard proper for the information exchange standard, and setting up an integrated management system to introduce a dual protocol.

• Wind and Structures
• /
• v.17 no.3
• /
• pp.299-315
• /
• 2013

Numerical research on four typical configurations of noise mitigation structures and their characteristics of wind loads are reported in this paper. The turbulence model as well the model parameters, the modeling of the equilibrium atmospheric boundary layer, the mesh discretization etc., were carefully considered in the numerical model to improve the numerical accuracy. Also a numerical validation of one configuration with the wind tunnel test data was made. Through detailed analyses of the wind load characteristics with the inclined part and the wind incidence angle, it was found that the addition of an inclined part to a noise mitigation structure at-grade would affect the mean nett pressure coefficients on the vertical part, and that the extent of this effect depends on the length of the inclined part itself. The magnitudes of the mean nett pressure coefficients for both the vertical part and the inclined part of noise mitigation structure at-grade tended to increase with length of inclined part. Finally, a comparison with the wind load code British/European Standard BS EN 1991-1-4:2005 was made and the envelope of the mean nett pressure coefficients of the noise mitigation structures was given for design purposes. The current research should be helpful to improve current wind codes by providing more reasonable wind pressure coefficients for different configurations of noise mitigation structures.