• Proceedings of the Korean Geotechical Society Conference
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• 2008.10a
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• pp.1555-1558
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• 2008

In this paper, result of whole test, When the Transfer Distance is increasing, Strength of Backfilling Material of NATM Composite lining Tunnel due to increasing Gravity was increased, but that is higher the Air Flotation than increasing Strength. So, That was predicted a drop of Permeability. And Performing the placing Lightweight Foamed Mortar, we think that it's performance in drain material was lost. Therefore We conclude that Proper Transfer Distance that taking Permeability through minimizing of Air Flotation Loss and getting the Need Strength is 50m.

• Proceedings of the Korea Electromagnetic Engineering Society Conference
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• 2003.11a
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• pp.33-37
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• 2003

This paper presents the characteristics of large-scale fading in a tunnel environment. The Ray-Launching Method has been used to analyze the characteristics of the tunnel. For a curved tunnel, The concept of RDN (Ray Density Normalization) is introduced in order to obtain more accurate results. For our purposes, the structure of tunnel is assumed to be either a straight or curved tunnel having rectangular cross-section. A large scale fading has been presented shown in several tunnel cases.

• Journal of the Institute of Electronics Engineers of Korea TC
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• v.43 no.5 s.347
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• pp.162-168
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• 2006

Understanding of propagation characteristics is very important for the wireless communication system design and wireless communication service construction. In this paper, propagation characteristics is measured and analyzed at 2.45Ghz frequency band under curved subway tunnel environment. We constituted channel measurement system with sliding correlation and five different kind of antennas. The purpose of five different type of antennas is to compare propagation characteristics according to beam shape of antennas. The path loss under tunnel environment is average $4.38^{\sim}14.41dB$ lower than free space and circular polarization antenna marked smallest path loss. Also, path loss is smallest when the receiver antenna located outside of tunnel in th curved section. 90% of delay components of all antennas measured within 20ns and directional antenna has more wide coherence bandwidth than omni-directional antenna. According to measured result, when we consider path loss and delay characteristics, circular polarization antenna is most suitable under tunnel environment.

• Asian-Australasian Journal of Animal Sciences
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• v.32 no.5
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• pp.748-756
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• 2019

Objective: The objective of this study was to examine the effect of using a tunnel ventilation system within the dairy barn environment upon the productivity of dairy cows during the winter season. Methods: The study was performed at the University Farm, Faculty of Agriculture, Utsunomiya University. Twenty-one Holstein dairy cows (5 heifers and 16 multiparous) were enclosed in a stall barn. Unventilated (UV) and tunnel-ventilated (TV) was operated by turns every other week, and a number of key parameters were measured in the barn, including tunnel ventilation output, temperature, relative humidity, gas concentrations (oxygen [$O_2$], carbon dioxide [$CO_2$], and ammonia [$NH_3$]). Also, skin and rectal temperature, respiratory rate, blood gas concentrations, and bacterial count were measured from nipple attachments on ten cows. The amount of fodder left uneaten, and general components and somatic cell count of the milk were measured. Results: As for our dairy barn environment, air temperature dropped significantly with the passage of time with TV. Humidity was significantly higher with TV at 0600 h compared to UV, while $CO_2$ and $NH_3$ concentrations with UV were significantly higher than with TV at 0000 h and 0600 h. Skin temperature was significantly lower with TV compared to UV at 0000 h and 0600 h. Respiratory rate was also significantly lower at 0600 h with TV than with UV. Bacterial count for the nipple attachments was significantly lower with TV than with UV at 0600 h. The amount of leftover fodder was significantly less with TV in comparison with UV. Conclusion: Our results suggest that a TV system in the winter barn results in environmental improvements, such as reductions in unfavorable gas concentrations and bacterial growth. Consequently, it is expected that barns utilizing a TV system will be beneficial for both animal health and production.

• Proceedings of the Korean Geotechical Society Conference
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• 2008.10a
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• pp.992-1006
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• 2008

The tunnel type spillways is under construction to increasing water reservoir capacity in Dae-am dam. Cutting-slope adjacent to outlet of spillways had been originally designed to be 63 degrees and about 65m in height. Examination is carried out in preceding construction that it is caused to some problems possibility which of machine for slope cutting couldn't approach to the site, blasting for cutting slope might have negative influence on highway and roads nearby, and fine view along the Tae-hwa river would be eliminated. In order to establish stability of tunnel and more friendly natural environment that we are carry out detailed geological surface survey and analysis of slope stability. So, we are design and construct for tunnel excavation with possible method that it is keep up natural slope. The result of survey and analysis that natural slope was divided 3 zone(A, B, C zone). In A and B zone, in first removed floating rock, high tensile tension net is install that it prevent of release and falling of rock, in order to security during under working. In addition to, pre-stressed rock anchor is install purpose of security during tunnel excavation because of fault zone near vertical developed above excavation level. Zone C is relatively good condition of ground, design is only carry out random rock bolt. All zone are designed and constructed drainage hole for groundwater and surface water is easily drain. Desinged slpoe is harmony with near natural environment. Successfully, construction is completed.

• Journal of Korean Society for Atmospheric Environment
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• v.30 no.6
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• pp.519-530
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• 2014

Twenty four individual polycyclic aromatic hydrocarbon (PAH) compounds both in gas- and particle-phase were quantified in three tunnels (Namsan Tunnel 3, Jeongneung Tunnel, Bukak Tunnel) to characterize vehiculate emission of PAHs. Gas phase PAHs were dominant in tunnels which consisted of 85% of total PAHs concentrations. Naphthalene and 2-methyl naphthalene were the most abundant gas phase PAH compounds, while the concentrations of fluoranthene and pyrene were highest in the particle phase. Most (96%) of the gas phase PAH compounds consisted of two- and three-aromatic rings whereas most of the particle phase PAHs were in four and five-rings (67%) in tunnels. Average BaP-eq concentrations of PAHs in the particle phase ($20.8{\pm}11.6ngm^{-3}$) was about twenty fold higher than that in the gas phase ($1.6{\pm}0.6ngm^{-3}$). It means that the particle phase PAHs has more adverse health effect than the gas phase PAHs even though the concentrations of the particle phase PAHs were lower than those of the gas phase PAHs. Compared to previous studies reporting diagnostic ratios for specific PAH compounds, the profile of individual PAH compounds measured in this study reflected well for the vehiculate emissions. We reported, for the first time, on the results of the profile of individual PAH compounds measured in tunnels for both gas and particle phases.

• Journal of Soil and Groundwater Environment
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• v.17 no.2
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• pp.28-36
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• 2012

This study carried out several kinds of investigations such as geology, hydrogeology, groundwater level and quality, surface-water quality, and the quantity and quality of groundwater discharge from the subway to identify the causes of groundwater contamination around the subway tunnel at Suyeong District in Busan City. Geostatistical analyses were also conducted to understand the characteristics of groundwater level and quality distributions. There are Kwanganri Beach and Suyeong River in the study area, which are basically influenced by seawater. The total quantities of groundwater utilization and groundwater discharge from the subway tunnel in Suyeong District are 2,282,000 $m^3$/year, which is 2.4 times larger than the sustainable development yield of groundwater. The lowest groundwater level around the subway tunnel is about 32 m below the mean sea-level. The large drawdown of groundwater led to the inflow of seawater and salinized river water toward the subway tunnel, and therefore the quality of groundwater didn't satisfy the criteria of potable, domestic, agricultural and industrial uses. Distribution maps of groundwater level and qualities produced by kriging were very useful for determining the causes of groundwater contamination in the study area. The distribution maps of electrical conductivity, chloride and sulfate showed the extent of seawater intrusion and the forceful infiltration of the salinized Suyeong River. This study revealed that seawater and salinized river water infiltrated into the inland groundwater and contaminated the groundwater around the subway tunnel, because the groundwater level was seriously drawdowned by groundwater discharge from the subway tunnel. The countermeasure for the minimization of groundwater discharge from the subway tunnel is necessary to prevent the groundwater obstacles such as groundwater depletion, groundwater-quality deterioration, and land subsidence.

• Journal of Korea Society of Industrial Information Systems
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• v.17 no.2
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• pp.19-27
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• 2012

In railway tunnel environment, the reliability of a high-data-rate and real-time train-to-wayside communication should be maintained especially when high-speed train moves along the track. In China and Europe, the communication frequency around 900 MHz is widely used for railway applications. At this carrier frequency band, both of the solutions based on continuously laid leaky coaxial cable (LCX) and discretely installed base-station antennas (BSAs), are applied in tunnel radio coverage. Many available works have concentrated on the radio-wave propagation in tunnels by different kinds of prediction models. Most of them solve this problem as natural propagation in a relatively large hollow waveguide, by neglecting the transmitting/receiving (Tx/Rx) components. However, within such confined areas like railway tunnels especially loaded with train, the complex communication environment becomes an important factor that would affect the quality of the signal transmission. This paper will apply a full-wave numerical method to this case, for considering the BSA or LCX, train antennas and their interacted environments, such as the locomotive body, overhead line for power supply, locomotive pantograph, steel rails, ballastless track, tunnel walls, etc.. Involving finite-difference time-domain (FDTD) method and uni-axial anisotropic perfectly matched layer (UPML) technique, the entire wireless RF downlinks of BSA and LCX to tunnel space to train antenna are precisely modeled (so-called integrative modeling technique, IMT). When exciting the BSA and LCX separately, the field distributions of some cross-sections in a rectangular tunnel are presented. It can be found that the influence of the locomotive body and other tunnel environments is very significant. The field coverage on the locomotive roof plane where the train antennas mounted, seems more homogenous when the side-laying position of the BSA or LCX is much higher. Also, much smoother field coverage solution is achieved by choosing LCX for its characteristic of more homogenous electromagnetic wave radiation.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.23 no.9
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• pp.1082-1087
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• 2019

Video Incident Detection System is a detection system for the purpose of detection of an emergency in an unexpected situation such as a pedestrian in a tunnel, a falling object, a stationary vehicle, a reverse run, and a fire(smoke and flame). In recent years, the importance of the city center has been emphasized by the construction of underpasses in great depth underground space. Therefore, in order to apply Video Incident Detection System to a Double Deck Tunnel, it was developed to reflect the design characteristics of the Double Deck Tunnel. and In this paper especially, the fire detection technology, which is not it is difficult to apply to the Double Deck Tunnel environment because it is not supported on existing Video Incident Detection System or has a fail detect, we propose fire detection using color image analysis, silhouette spread, and statistical properties, It is verified through a real fire test in a double deck tunnel test bed environment.

• Geotechnical Engineering
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• v.10 no.2
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• pp.41-56
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• 1994

Under the groundwater level, the tunnel face is affected by the seepage force and the groundwater flow may cause a trouble to the tunnel support systems. The appropriate methods of analysis and design in the tunnel face and the lining, considering groundwater flow according to tunnel drainage condition are presented in this thesis. First, the effect of seepage on the stability of tunnel face was studied. Seepage force was estimated by the 3-D finite element analysis and the stability of tunnel face was checked by analytical method. Furthermore, using the finite difference method the stress and displacement on the face were computed for either case, where the seepage force is or is not considered, and the effect of seepage on the tunnel face stability was evaluated. Second, the effect of seepage force on the tunnel lining when construction is finished and steady state seepage flow occurs was studied and a design methodology considering seepage effect was made. Consequently, in case where the groundwater level remains almost unchanged and the steady state groundwater flow occurs, the proper countermeasures for face staility are required according to the condition of groundwater flow. Moreover, the tunnel lining should be designed and constructed considering the seepage force occuring by the groundwater flow toward the tunnel linings.