• The Transactions of The Korean Institute of Electrical Engineers
• /
• v.63 no.5
• /
• pp.703-712
• /
• 2014

To improve the efficiency and safety of railway systems, the train control system has been considerably evolved from the ground-equipment-based control system (e.g. track circuit, interlocking system, etc.) into the on-board-equipment-based control system. In addition, this train control system enables the rolling stock to intelligently control the trackside facilities by introducing the information and communication technologies (ICT). Accordingly, since the ICT-based train control system makes the railway system be simplified (i.e. the heavy ground-equipment can be removed), the efficient and cost-effective railway system can be realized. In this paper, we perform the feasibility test of the ICT-based train control system via a simulation. To this end, we have developed the prototypes of the on-board controller and wayside object control units which control the point and crossing gate and performed the integrated operation simulation in a testbed. In this paper, before the field test of the on-board-controller-based train control system, we perform the Consecutive operation test for prototypes of the on-board controller, wayside object control units and local control computer.

• Korean Journal of Veterinary Research
• /
• v.44 no.4
• /
• pp.637-641
• /
• 2004

A variety of enteric deseases may result in the manifestation of abdominal pain in horse. An acute colic in a 5-month-old Thoroughbred filly is described. The filly was presented with acute colic characterized by rolling and pawing. Next day she suffered from severe abdominal pain and subsequently died. Post mortem examination revealed very heavy ascarid, Parascaris equorum (P. equrum) infection in cmall intestine. In addition, it is also noted the presence of P. equorum in the stomach. Infection due to P. equorummanifests itself in foals between 6-8weeks and one year of age. P. equorum is a common and ubiquitous parasite that persists for many years in stables and on pasture in spite of good hygiene and anthelmintic control programs.

• International Journal of Highway Engineering
• /
• v.16 no.5
• /
• pp.9-18
• /
• 2014

PURPOSES : The objective of this study is to evaluate the applicability of the pitch, which is produced during SDA petroleum upgrading process, as a pavement paving material. In order for the purpose, the physical and chemical properties of the pitch are analyzed, and then the various plasticizers are applied in the pitch. METHODS : Two types of pitch are selected from oil refinery companies, which are owned the SDA petroleum upgrading process. Also, two types of asphalt binders, PG 64-22 and PG 58-22, are employed to compare with the pitch because these two types of asphalt binders are currently used as paving materials. For the chemical property of the pitch, the composition of SARA (Saturate, Aromatic, Resin, Asphaltene), the elementary composition, and the functional group are analyzed. For the physical property of the pitch, the basic material property tests, such as penetration test, softening point test, flash point test, ductility test, and rotational viscometer test, are performed. Also, the DSR (Dynamic Shear Rheometer) test and the BBR (Bending Beam Rheometer) test are conducted using asphalt binder specimens obtained by both short term aging (Rolling Thin Film Oven, RTFO) and long term aging (Pressure Aging Vessel, PAV) processes. The rheological property of each pitch type is evaluated as a function of temperatures and loading cycles. PG 64-22 asphalt binder is used as a control material. RESULTS AND CONCLUSIONS : The Pitch may not be suitable for the pavement paving material without modifications, but the pitch can be used as alternatives of modified addictive or asphalt. If low molecular component, such as saturate and aromatic components, are added in the pitch based on the development of various plasticizers, it has a strong possibility for the pitch to be used as a alternative. However, in order to verify the performance property of the pitch, further research is needed.

• KSCE Journal of Civil and Environmental Engineering Research
• /
• v.38 no.2
• /
• pp.319-325
• /
• 2018

Pot-holes are steadily increasing due to abnormal climate such as heavy rainfall and frequent snowfall. Pot-hole related to traffic accidents cause injuries, car damage and distress of road facilities. To reduce pot-holes, the use of an anti-stripping agent is mandatorily recommended to asphalt concrete mixture. Hydrated lime is commonly used as anti-stripping agent due to the convenience and economics. Byproduct ash from circulating fluidized bed boiler was reviewed as an anti stripping agent. According to the test results, the byproduct ash is satisfied with TSR specification using 1% to 3% by weight of the asphalt mixture. The byproduct ash was examined under various condition changes of aggregate and asphalt concrete mixture considering quality movement. According to the results, using the byproduct ash was measured average 0.87 of TSR and coverage rates of 60% after rolling bottle test. Test results also revealed that the byproduct ash showed stable performance. Using the byproduct ash to decrease pot-hole in asphalt concrete pavement is suitable for demonstrating stable performance as anti-stripping agent.

• Economic and Environmental Geology
• /
• v.18 no.1
• /
• pp.55-63
• /
• 1985

Studies based on field observation and laboratory analysis of the littoral sands of beaches in Jeju Island indicate that the shores exhibit a great variation in both the beach geometry and the composition in terms of geological agents. Most of the beaches around the Island are developed in relatively small patches and discontinuous, as the result of intervening sea cliffs and rocky headlands. The sand quality and the dimensions of the beaches in the Island are relatively poor; for example, these beaches are 220~2,780m in length, 41~313m in width, and $7^{\circ}$ steepness in average foreshore slope. According to the textural parameters analysis, the beach sediments in study portion shows medium grained ($average\;1.42{\phi}$), moderately well sorted ($average\;0.65{\phi}$) and negative skewed ($average\;0.34{\phi}$), which seems to reflecting a high energy marine depositional environment. The heavy and light minerals of te beach sediments are composed of quartz, volcanic fragments, Na-Ca feldspar, olivine, augite as major constituents, along with apatite, biotite and other minor components, which originates from the adjacent geology. The content of CaO-MgO in shell fragments of the littoral sands ranged from 4.69~51.96%, suggesting that the high CaO-MgO content in some of the Island's beaches is attributable to geologic environments conducive to the growth of shell organisms and sediments migration. The provenance of the sediments studied are derived predominantly from adjacent continental shelves and/or terrigenous older river portion, Which sediments were transported mostly by rolling or bottom suspension. The depositional environments of the Jeju beaches can be divided into two types: beaches distributed in the North and the Northeastern parts of the Island are dominated by marine enviroment, whereas beaches in the Southwestern portion are characterized by terrigenous agencies.

• Proceedings of the KSR Conference
• /
• 2009.05a
• /
• pp.284-290
• /
• 2009

As the increased importance is placed on the new transit systems owing to the environmental pollution caused by the road traffic congestion, the policy for the introduction of the new transit systems as an alternative solution to ease the heavy burden of the construction expenses is being actively established. Since the explicit recognition of such transit systems and the review on the method of its adoption have been a pressing matter in the light of reducing the pending traffic congestion, the development of the rolling stock systems in modes of new transportation has been made in various ways taking into consideration the regional circumstances to alleviate traffic congestion, and offer a more efficient service with the application of their intrinsic characteristics. Such systems also have been developed as a mix of punctuality for railway systems operating on the runway and flexibility for buses. This paper, therefore, deals in more detail with 3 modes of systems such as low-floor articulated buses, GRT(Guided Rapid Transit) and tram cars, and studies the overseas cases of the operation of those systems involving both negative and positive aspects.

• Journal of the Computational Structural Engineering Institute of Korea
• /
• v.25 no.1
• /
• pp.27-36
• /
• 2012

The mobile harbor is a new concept system to solve the problems of a port. These problems are that container ships cannot be anchored at the dock because they have become larger or the waiting times of anchoring the ships are increased due to heavy container traffic. A new system is designed to carry out the loading and unloading of containers between the mobile harbor and the container ship using the mobile harbor crane at sea. The crane plays an important role when transferring the containers. In this research, various types of the mobile harbor crane are proposed and structural optimization for each type of the crane is carried out. The loading conditions consider the rolling and pitching conditions of the unstable sea state and the wind force are considered. The constraints are mainly the regulations made by the Korean Register of Shipping. The structure of the crane is optimized to minimize the mass while various constraints are satisfied.

• Journal of the Korean Society of Marine Environment & Safety
• /
• v.7 no.3
• /
• pp.17-28
• /
• 2001

The wheelhouse front glass of a Fore-Bridge-Ship (Ro-Ro Ship) was broken by the shipping of water in rough seas, and then the flooding of seawater into the wheelhouse caused the uncontrollable condition of the ship. The hull which was entered into the floating condition rolled severely, and the heavy rolling caused secondary damage such as the collapse of a lot of cargo. It was an incredible accident because the height of bow freeboard was about 2.5 times higher than the standard height of minimum bow freeboard regulated by the International Load Line Convention(1966). And it would be also difficult for navigators to imagine a great deal of seawater flooding into the wheelhouse because the front glass was positioned at about 20m height above the sea surface. In this paper, we carried out the evaluation for the safety navigation of the Fore-Bridge-Ship numerically against ship's speed and encountering angle to the wave in each sea state of rough sea, by using the integrated seakeeping performance index (ISPI) which is able to evaluate synthetically the safety operation of ships. And then the problem on the application of the past criteria proposed as the safety navigation of a merchant ship was clarified by inquiring the dangerousness of the shipping of water at her bow deck, which caused the breakage of the wheelhouse front glass.

• Proceedings of the Korea Water Resources Association Conference
• /
• 2018.05a
• /
• pp.149-149
• /
• 2018

Prediction on initial motion of sediment is crucial to evaluate sediment transport and channel stability. The condition of incipient movement of sediment is characterized by bed shear stress, which is generated from force of moving water against the bed of the channel, and by critical shear stress, which depends on force resisting motion of sediment due to the submerged weight of the grains. When the bed shear stress exceeds the critical shear stress, sediment particles begin rolling and sliding at isolated and random locations. In Mountain River, debris flow frequently occurs due to heavy rainfall and can lead some natural stones from mountain slope into the bed river. This phenomenon could add additional forces to sediment transport system in the bed of river and also affect or change direction and magnitude of sediment movement. In this paper, evaluations on incipient motion of uniform coarse gravel under falling spheres impacts using small scale flume channel were conducted. The drag force of falling spheres due to water flow and length movement of falling spheres were investigated. The experiments were carried out in flume channel made by glass wall and steel floor with 12 m long, 0.6 m wide, and 0.6 m deep. The bed slopes were selected with the range from 0.7% to 1.5%. The thickness of granular layer was at least 3 times of diameter of granular particle to meet grain placement condition. The sphere diameters were chosen to be 4cm, 6 cm, 8 cm, 10 cm. The spheres were fallen in to the bed channel for critical condition and under critical condition of motion particle. Based on the experimental results, the Shields curve of particles Reynold number and dimensionless critical shear stress were plotted. The relationship between with drag force and the length movement of spheres were plotted. The pathways of the bed material Under the impact of spheres falling were analyzed.

• Journal of People, Plants, and Environment
• /
• v.24 no.1
• /
• pp.39-51
• /
• 2021

Background and objective: Urban topology can be characterized as impervious, which changes the hydrologic features of an area, increasing surface water flow during local heavy rain events. The pluvial flooding is also influenced by the vertical structures of the urban area. This study suggested a modified digital elevation model (DEM) to identify changes in urban hydrological conditions and segmentalized urban micro catchment areas using a geographical information system (GIS). Methods: This study suggests using a modified DEM creation process based on Rolling Ball Method concepts along with a GIS program. This method proposes adding realized urban vertical data to normal DEM data and simulating hydrological analyses based on RBM concepts. The most important aspect is the combination of the DEM with polygon data, which includes urban vertical data in three datasets: the contour polyline, the locations of buildings and roads, and the elevation point data from the DEM. DEM without vertical data (DCA) were compared with the DEM including vertical data (VCA) to analyze catchment areas in Shin-wol district, Seoul, Korea. Results: The DCA had 136 catchments, and the area of each catchment ranged from 3,406 m² to 423,449 m². The VCA had 2,963 catchments, with the area of each ranging from 50 m² to 16,209 m². The most important finding is that in the overlapped VCA; the boundary of areas directly affected by flooding and the direction of surface water flow could be identified. Flooding data from September 21, 2010 and July 27, 2011 in the Shin-wol district were applied as ground reference data. The finding is that in the overlapped VCA; the boundary of areas directly affected by flooding and the direction of surface water flow could be identified. Conclusion: The analysis of the area vulnerable to surface water flooding (SWF) was more accurately determined using the VCA than using the DCA.