• Korean System Dynamics Review
• /
• v.4 no.2
• /
• pp.131-151
• /
• 2003

Traffic congestion stems from the widespread desires of people to purse certain goals that inevitably overload existing roads every day. he a transportation policy, congestion toll system has been implemented in Seoul, since 1996. The growing concerns on whether the system would achieve sustained results in the future motivated us to investigate the effectiveness of this policy. Developing and running the congestion toll simulation model, we find that this policy is not an effective policy in the long m. The paper indicates the power of system dynamics approach as a tool for evaluating complex policy like a congestion toll, and suggest that city transportation policy maker should approach the problem with systems thinking and analyze the effectiveness of policy on the basis of understanding the dynamic relationships among subsystems.

• Explosives and Blasting
• /
• v.23 no.2
• /
• pp.1-14
• /
• 2005

The Korean Atomic Energy Research Institute is currently planning the construction of an Underground Research Tunnel to carry out research and development related to the disposal of high-level wastes from nuclear reactors used to generate electrical power. This paper discusses the excavation methods used to construct the Canadian Underground Research Laboratory and their application in planning for the construction of a similar underground laboratory and eventually an underground repository for high-level wastes in Korea.

• Wind and Structures
• /
• v.8 no.4
• /
• pp.269-281
• /
• 2005

The paper describes the work of the IAWE Working Group WGF - Extreme Wind Prediction and Zoning, one of the international codification working groups set up in 2000. The topics covered are: the international database of extreme winds, quality assurance and data quality, averaging times, return periods, probability distributions and fitting methods, mixed wind climates, directionality effects, the influence of orography, rare events and simulation methods, long-term climate change, and zoning and mapping. Recommendations are given to promote the future alignment of international codes and standards for wind loading.

• Proceedings of the Korean Society of Precision Engineering Conference
• /
• 2000.11a
• /
• pp.555-558
• /
• 2000

Conventional aerodynamic simulations have carried out by using Supercomputer and over a hundred grid point or wind tunnel experiment. It takes s long time to get a result. This paper has dealt on flow characteristics of automobile in the flow field. CFD(Computational Fluid Dynamics) has been able to apply to industrial field in these days. This new method has been applied to the aerodynamic simulation system, a designer has been able to carry out the practical on early designing phase of automobile. This paper has been focused on the necessity of rear-spoiler, the peculiarity of aerodynamic drag, and the level of drive safety.

• Proceedings of the KSR Conference
• /
• 2010.06a
• /
• pp.389-396
• /
• 2010

After analyzing network of the region of western sea, which is the center of Circle Yellow-Sea economic region, and Circle Bo-Hai and the delta of a long river economic region, which are belong to three major economic region of China, as an efficient strategy, rail & sea multi-transport system of Korea-China joint SOC strategy is suggested. Rail & Sea multi-transport system, which is the links of railroads and shipping transport, can be subdivided into train-ferry, which is the transport of loaded trains into a vessel, and transshipment, which is transshipment of containers from railroads to vessels. And, the way of railroads transport through a tunnel under the sea is also suggested.

• Proceedings of the SAREK Conference
• /
• 2009.06a
• /
• pp.739-744
• /
• 2009

The filter has long been used in purification processes for indoor air quality. To determine the deodorization effect of several filter materials in a full-scale air-handling system, the present study has been carried out using a wind tunnel equipped with a heat exchanger and various filter materials, such as commercial fabric, activated carbon(AC) and silver nano-particles attached to activated carbon(Ag-AC). The experiment was conducted using an odor substance with ammonia, acetaldehyde, acetic acid. The results obtained indicate that odor substance is substantially decreased on the moisture condensation on the surface of the heat exchanger. The fabric filter has no effect for removal of odor substances. The deodorization efficiency is found to be approximately 7% in the AC filter, while the deodorization efficiency is increased up to 10% using the Ag-AC filter.

• Proceedings of the Optical Society of Korea Conference
• /
• 2000.02a
• /
• pp.130-131
• /
• 2000

One of the more promising proposals for guiding and focusing neutral atoms involves dark hollow laser beams. When the frequency of the laser is detuned to the blue of resonance, the dipole force the atoms feel in the light confines them to the dark core where the atoms can be transported with minimal interaction with the light. The ability of the all-light atom guides to transport large number of ultracold atoms for long distances without physical walls leads to the possibility of a versatile tool for atom lithography, atom interferometry, atomic spectroscopy as well as for transporting and manipulating Bose-Einstein condensates. Furthermore since the atoms transported in all-light atom guides do not come into contact with matter, they can in principle be used to transport antimatter as well. The ability to vary the core size of the hollow beam makes the all-light atom guide potentially useful for focusing neutral atoms. The atoms could be focused as tight as the core size of the hollow beam at its waist. This new focusing scheme, called the atom funnel, would not show spherical and chromatic aberrations that conventional harmonic focusing suffers from. (omitted)

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
• /
• 2000.06a
• /
• pp.811-816
• /
• 2000

It has been long suspected that the transition region may give rise to local pressure fluctuations and radiated sound that are different from those created by the fully-developed turbulent boundary layer at equivalent Reynolds number. Experimental investigation described in this paper concerns the characteristics of pressure fluctuations at the transition. Flush-mounted microphones and hot wires are used to measure the pressure fluctuations and local flow velocities within the boudary layer in the low noise wind tunnel. From this experimental we could observe the spatial and temporal development process of T-S wave using Wigner-Ville method and found the possibility of relation between the characteristic frequency of T-S wave and free stream velocity and the boundary layer thickness based on nondimensional pressure spectra scaled on outer variables.

• Proceedings of the Korea Concrete Institute Conference
• /
• 1996.04a
• /
• pp.225-231
• /
• 1996

The dense graded asphalt concrete materials have been used for construction of pavement for a long time. The performance of asphalt concrete pavement, however, is influenced by various factors including high temperature and heavy axle loads which cause plastic deformation. The plastic deformation is one of the main functional disadvantages of flexble pavement. In this study, the semi-rigid pavement is considered to solve the problem. A set of experimental evaluation on semi-rigid pavement material has been coducted in laboratory to obtain it's physical properties and serviceabilities. The results of tests, including compressive strength, flexural strength, ravelling and wheel tracking, show that the semi-rigid pavement has a good mechanical properties and serviceabilities. Consequently, the semi-rigid pavement may be suitable to bridge deck, tunnel, slow lane and parking area pavements.

• Magazine of korean Tunnelling and Underground Space Association
• /
• v.22 no.1
• /
• pp.26-35
• /
• 2020

Tunnelling to bypass major landslide areas is considered as a good and long-term environmentally friendly solution to reduce an existing hazard. In Norway, hundreds of kilometres of tunnels have been constructed in areas prone to landslides and snow avalanches. Although tunnelling is considered as an expensive mitigation strategy for bypassing landslides, analysis indicate that in some cases the cost of building a tunnel can be repaid by savings in driving costs (fuel) alone over a period of 5-10 years due to reduced driving distances. The other benefits of constructing tunnels in landslide areas include savings in time and increased safety. The Norwegian Method of Tunnelling (NMT) is considered safe, efficient and cost effective compared to other tunnelling techniques. Some aspects of NMT, which are considered safe and cost efficient, are presented. The application of updated rock support techniques, including reinforced ribs of shotctrete (RRS), which is a key component of the Norwegian Method of Tunnelling (NMT), is highlighted.