• Journal of Korean Society of Steel Construction
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• v.17 no.6 s.79
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• pp.673-679
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• 2005

According to continuous welded rails on a bridge, temperature changes bring about the expansion of the bridge deck,adding axial forces on the track. Moreover, the ballast on the bridge deck expansion joint is moved due to the bridge deck. The longer the bridge deck is, the greater the influence will be, loosening the ballast, causing track irregularities, and deteriorating passenger comfort. Considering the structure of the bridge itself and tolerance for track irregularities caused by the loosened ballast on the bridge, the maximum length of the deck should be less than 80 m, which is the same as the standard of French railways. In this study, the interaction between the expansion related to the bridge length and the irregularity in the longitudinal level, referring to measurements and maintenance work performed in high-speed railways, was analyzed. This research shows that the installation of a sliding plate or a vertical ballast stopper is not a good option, since it is difficult. On the other hand, the installation of a ZLR fastener or gluing is easy, but its influence is insignificant. In conclusion, switch tie tamping or manual tamping is more effective than other methods of what?

• Proceedings of the KIPE Conference
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• 2009.11a
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• pp.105-110
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• 2009

The On Line Electric Vehicles(OLEV) that can pick up inductive power from underground coils on driving with high efficiency have been developed this year, and is now proposed in this paper. The IPS(Inductive Power Supply) system consists of power supply inverters, power supply rails, pick up modules, and a regulator. There are 3 generations of IPS have been developed so far, and the $4^{th}$ generation IPS is being developed. The $1^{st}$ generation has been demonstrated this Feb. 27, which is equipped with mechanically auto tracking pick-up module with 1cm air gap, and showed 80% power efficiency. The $2^{nd}$ generation IPS applied to an 120kW (average)/240kW(peak) motor powered electric bus has 17cm air gap with 72% power efficiency. For the $2^{nd}$ generation IPS, the Power supply inverter has 440V, 3phase input and 200A @ 20kHz output. The test power supply rail of 240m long is segmented by 60m each, where newly developed core structure and power cable are constructed under the road covered with asphalt of 5cm thickness. The pick-up modules which consist of core, winding wire, and rectifiers are fixed to the bottom of the bus which can carry more than 40 passengers and can pick up max. 60kW. To remove parasitic component and to transfer maximum power between them resonant circuit topology is applied to the primary and secondary sides. The EMF level is below 62.5mG at 1.75m from the center of the road to meet the regulation. Several effective ways of reducing EMF levels have been developed. In addition, effective ways to solve problems related high frequency power cables buried in ground and it's proof from soil have been studied also. This development shows that the IPS system is capable of supplying enough power to the pick-up of OLEV and can reduce battery size, weight and cost, which means the IPS with OLEV is one of the best candidate for EV.

• Korean Journal of Clinical Laboratory Science
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• v.50 no.3
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• pp.359-369
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• 2018

An essential measure to prevent healthcare-associated infections (HAI) is to develop a consistent system of surveillance, thereby promoting a reliable situation diagnosis to perform efficient control for the problem. Patient-to-patient transmission of pathogens within the hospital plays a substantial role in the epidemiology of HAIs. Contamination of healthcare environments commonly occurs, including facilities surfaces (e.g., bed rails, bedside tables), drinking water, cooling tower water, endoscopic instruments, food, airborne, endotoxin test, sterile test and medical equipment, with pathogenic organisms. In addition, epidemiological analysis is performed by multi locus sequence tying, pulsed-field gel electrophoresis for active surveillance. Therefore, an environmental surveillance culture test for prevention improves patient safety and blocks infection agents. Effective infection control and increased safety are possible by controlling the national infection control system. In conclusion, this study contributes to an effective infection control system through the standardization of active surveillance culture laboratory and secure expertise as infection control specialist. The primary objective of the standardization is to improve the safety of the nation's healthcare system by reducing the rates of HAIs.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.20 no.2
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• pp.106-113
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• 1987

The Alaska pollack longline operations, which consist of baiting, shooting, hauling and arrangement of hooks, are dependant on manual labour up to the present. The automation against this traditional way is necessary to eliminate the manual operations and to reduce crew. We have developed a prototype longline system suitable for Alaska pollack longline gear, which is composed of an automatic baiting machine, an automatic line hauler, a hook cleaner and storage rails. The automatic bailing machine driven by hydraulic power is precise baiting method controlled sequentially, and the automatic line hauler is to haul up the mainline by means of hydraulic power and at the same time to split every hook and to carry it onto storage rail automatically. A series functioning tests on shooting and hauling apparatus were carried out in the laboratory and at sea. The results obtained are as follows ; 1. As for the baiting machine, the exciting time of solenoid which operates a directional valve, bait feeding and cutting time, is shortened according to the increase of pressure, and also, after cutting the bait, the over-rotated angle of the blade increased in accordance with the increase of pressure. 2. The baiting efficiency is about $90\%$ when using sand lance (Hypoptychus dybowskii), and the most proper pressure of the hydraulic circuit in feeding and cutting the bait is between $13\;kgf/cm^2\;and\;20\;kgf/cm^2$. 3. The hook splitting rate of the automatic line hauler is about $95.5\%$ regardless of hauling speed and materials of snood. 4. The case of unseparating hook is appeared when the snood gets entangled or the hook is sticked in the mainline.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.19 no.7
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• pp.275-282
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• 2018

Mountain trams are an environmental-friendly transportation system that run wirelessly on an embedded track constructed on previous mountain roads, and can run despite the frozen road. On the other hand, there is some difficulty on sharp and steep tracks. In this study, after possible technical problems were defined in mountain trams running on a sharp and steep track, the design solutions for the interface structure of bogie and carbody were proposed. In addition, a prototype was made and its performance was tested to verify the solutions. Because the difference in the distance of the inner and outer rails on a sharp curve is severe enough to interrupt running, independent rotating wheels with different angular speeds were developed and applied. To prevent derailment due to the large attack angle and lateral force caused by the previous vehicle of 2bogie-and-1carbody on the sharp curve, a vehicle with 1bogie-and-1carbody was designed and applied. A prototype vehicle of 1bogie-and-1carbody with independent rotating wheels was made to improve the performance during the test running on a small track. A coupler was designed to absorb the large rotations of 3 degrees-of-freedom between the carbodies of a mountain tram running on the steep curved track. After a small scale prototype was made, the performance was verified by a function test.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.19 no.4
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• pp.532-542
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• 2018

Because maglev trains have a propulsion and absorption force without contact with the rails, they can drive safely at high-speed with little oscillation. Recently, test model of a maglev propulsion train was produced and operated, and has since been chosen as a national growth industry in South Korea; there have been many studies and considerable investment in these fields. This study examined the dynamic responses due to bridge-maglev train interaction and basic material to design bridges for maglev trains travelling at high-speed. Depending on the major factors affecting the dynamic effects, the scope of this study was restricted to the relationship between dynamic responses. A concrete box girder was chosen as a bridge model and injured train and rail types in domestic production were selected as the moving train load and guideway analysis model, respectively. From the analysis results, the natural frequency of a bridge for a maglev train, which has a deflection limit L/2000, was higher than those of bridges for general trains. The dynamic responses of the girder of the bridge for a maglev train showed a substantial increase in proportion to the velocities of the moving train like other general bridge cases. Maximum dynamic response of the girder is shown at a moving velocity of 240km/h and increased with increasing moving velocity of train. These results can be used to design a bridge for maglev propulsion trains and provide the basic data to confirm the validity and verification of the design code.

• Journal of Korea Water Resources Association
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• v.47 no.4
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• pp.397-409
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• 2014

In this study, the assessment scheme has been developed to evaluate the ecological function of rivers which were changed by the river improvement project. The evaluating factors are composed of physical structure in river channels and ecological connectivity in river areas, and each value of the factors is quantified based on 4 and 2 variables, respectably. This scheme was applied to past (1918, before artificial river improvement) and present Mankyung River area. A GIS model was adopted for calculating, analysing, and presenting river ecological conditions using the 204 grids and 7 reaches in study area. Comparison results show that the evaluation grade was decreased in both factors after river improvement. The main causes of lower grade (from II to IV) for physical structure are the river straightening and crossing structures. The reduction (from II to III) in ecological connectivity grade effected by linear fragmentation due to roads and rails is found to be greater than areal fragmentation due to land-use. In particular, it is also found that a high degree of ecological connectivity in 1918 was distributed along the river, but that one in 2007 showed a tendency to scatter because of the construction of levee and increase of urbanized area.

• Korean Journal of Agricultural Science
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• v.29 no.2
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• pp.10-19
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• 2002

This study was conducted to investigate the avifauna of Gap stream in Daejeon metropolitan city from September in 2001 to August in 2002. For the monthly change of bird community, survey was carried at study area per each month, the obtained results could be summarized as follows. 1. The observed birds were 12 orders 31 families 83 species and 15900 individuals, 38 species are water bird as Herons, Dabbling ducks, Diving ducks, Rails, Sandpipers & Plovers and 45 species are land bird as Raptors, Woodpeckers, Wagtails, Thrushes, Warblers, Tits, Buntings, Crows. 2. These birds could be divided 29 residents, 29 summer visitors, 18 winter visitors, 7 passage migrants. 3. Among the birds, Chinese Sparrowhawk Accipiter soloensis, Eurasian Sparrowhawk Accipiter nisus, Kestrel Falco tinnunculus are legally protected species as natural monuments in Korea. 4. The major dominant species were Common Teal Anas crecca, Spot-billed Duck Anas poecilorhyncha, Mallard Anas platyrhynchos, Grey Heron Ardea cinerea, Magpie Pica pica, Little Egret Egretta garzetta in order, Gap stream should be appropriate habitats for dabbling ducks and herons. 5. Among the total number of 83 species, the highest number of species was 37 species in February and the lowest number of species was 27 species in June. 6. Among the total number of 15900 individuals, the highest number of individuals was 2899 individuals in December and the lowest number of individuals was 385 individuals in May. 7. Among the monthly species diversity index, the highest number of species diversity index was 2.6207 in September and the lowest number of species diversity index was 2.0716 in January.

• Proceedings of the Korean Geotechical Society Conference
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• 2006.03a
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• pp.86-95
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• 2006

Brillouin backscatter is a type of reflection that occurs when light is shone into an optical fibre. Brillouin reflections are very sensitive to changes in the fibre arising from external effects, such as temperature, strain and pressure. We report here several case studies on the measurement of strain using Brillouin reflections. A mechanical bending test of an I beam, deployed with both fiber optic sensors and conventional strain gauge rosettes, was performed with the aim of evaluating: (1) the capability and technical limit of the DTSS technology for strain profile sensing; (2) the reliability of strain measurement using fiber optic sensor. The average values of strains obtained from both DTSS and strain gauges (corresponding to the deflection of I beam) showed a linear relationship and an excellent one-to-one match. A practical application of DTSS technology as an early warning system for land sliding or subsidence was examined through a field test at a hillside. Extremely strong, lightweight, rugged, survivable tight-buffered cables, designed for optimal strain transfer to the fibre, were used and clamped on the subsurface at a depth of about 50cm. It was proved that DTSS measurements could detect the exact position and the progress of strain changes induced by land sliding and subsidence. We also carried out the first ever distributed dynamic strain measurement (10Hz) on the Korean Train eXpress(KTX) railway track in Daejeon, Korea. The aim was to analyse the integrity of a section of track that had recently been repaired. The Sensornet DTSS was used to monitor this 85m section of track while a KTX train passed over. In the repaired section the strain increases to levels of 90 microstrain, whereas in the section of regular track the strain is in the region of 30-50 microstrain. The results were excellent since they demonstrate that the DTSS is able to measure small, dynamic changes in strain in rails during normal operating conditions. The current 10km range of the DTSS creates a potential to monitor the integrity of large lengths of track, and especially higher risk sections such as bridges, repaired track and areas at risk of subsidence.

• Journal of Korean Society for Geospatial Information Science
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• v.16 no.4
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• pp.3-10
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• 2008

Cadastral map is a public book that has been composed by continuous parcel having location, number, classification, boundary and an area based on Cadastral Law. A few years ago, cadastral map had been managed by form drawn on 2 dimension plane paper with 7 regular scales. Recently as computer systems are upgrading, cadastral map was able to have a chance to develope one step. Its type has been remade from raster to vector. In result, the cadastral map of vector type becomes to apply variously. Therefore, digital cadastral map has been ready a system to be use with multi-propose by KLIS(Korean Land Information System). In this research, it concretely want presentation of status using land more than original parcel on basic coordination cadastral map and KLIS(Korean Land Information System). The cadastral map is composed as parcel unit was applied by new presentation technique to "Model Research on One Parcel Presentation Technique for Land Status of Cadastral Map". The function of cadastral map on One Parcel Presentation Technique which is not only location relation of possession right and expression of states using land in 28 classifications demonstrated on the cadastral law but also used as foundation data of GIS construct business is developed by lines and classification of parcel to center around public sites of roads, rails, drains and rivers. especially, this research is composed of technique elevation and development of One Parcel Projection Technique of cadastral map in using object of roads among public sites.