• Proceedings of the KSR Conference
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• 2000.05a
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• pp.143-150
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• 2000

Like conventional railways, improving running performance of vehicle in curve is more effective than improving maximum speed to reduce traveling time. But some vehicles have problems concerning running performance in cure because of insufficient study for our conventional railway characteristics. So, these problems brought about increasement of maintenance cost. This study was started to deliberate several plans to solve problems concerning running performance in curve. Some modifications of primary suspension and tests were carried out to improve curve negotiation. Here, we describe some results.

• Proceedings of the KSR Conference
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• 2006.11b
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• pp.281-287
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• 2006

Subway line becomes an important way of transportation as road traffic goes to limit. Recently the large number of passengers of the subway lines near metropolitan area, In-Cheon, Su-Won, Pyung-Teak and Chon-An, is rapidly increasing. The electric cars of the No. 1 subway line in the suburbs are now running fast compared to the downtown area. However, the fast electric car can be uncomfortable to ride in, because there are so much noise and vibration. In this research, the running characteristics of the electric car of the No. 1 subway line in the suburbs is investigated through the measurements of the noise and vibration at running condition.

• Journal of information and communication convergence engineering
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• v.19 no.1
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• pp.61-66
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• 2021

An underwater remotely operated vehicle (ROV) has been implemented. It can inspect foreign substances through a CCD camera while the ROV is running in water. The maximum thrust of the ROV's running thruster is 139.3 N, allowing the ROV to move forward and backward at a running speed of 1.03 m/s underwater. The structural strength of the guard frame was analyzed when the ROV collided with a wall while traveling at a speed of 1.03 m/s underwater, and found to be safe. The maximum running speed of the ROV is 1.08 m/s and the working speed is 0.2 m/s in a 5.8-m deep-water wave pool, which satisfies the target performance. As the ROV traveled underwater at a speed of 0.2 m/s, the inspection camera was able to read characters that were 3 mm in width at a depth of 1.5 m, which meant it could sufficiently identify foreign objects in the water.

• Proceedings of the KSR Conference
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• 2011.10a
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• pp.1905-1913
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• 2011

The dynamic characteristic of bogie that is driving system of railway vehicle is very important regarding decision of vehicle characteristics as running safety and comport. The dynamic characteristic test of bogie is tested on full size in place on field testing on track. But, the testing on the full size caused many problems. To overcome these problem by full size test, the Railway Safety Research Center in Seoul National University of Science & Technology developed 1/5 scale size of small scale derailment simulator and is currently testing running stability of 1/5 scaled bogie. Also To take effectively advantage of running stability test using small scale derailment simulator in actuality design and reliability estimation, it is necessary comparison and examination with field test and theoretical analysis result In this paper. to achieve running stability analysis of 1/5 scaled bogie on small scale derailment. the program using MATLAB that is fast compose and analysis the motion equation of Saemaul power bogie is developed. It is achieved analysis according to various specification (weight, size, suspension, etc..) and is evaluated corelation between test result and dynamic characteristic of actual railway vehicle.

• Proceedings of the IEEK Conference
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• 2004.08c
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• pp.772-775
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• 2004

Generally, arterial pulse waves are measured at the radial arterial of wrist or carotid arterial of neck using a sensor such as pressure sensor, piezoelectric sensor or optic sensor. But in this paper, arterial pulse wave is measured at the temple using PZT piezo sensor which is attached on the temple in form of a hair-band. Arterial Pulse waves are generally measured when a reagent is in a static state. But in this paper, we implemented the arterial pulse wave measurement system, as a previous stage of the arterial pulse wave measurement system for running at outdoors or on a running machine, that measures arterial pulse waves at the temple, which is the least moving part when running. Thorough the continuous study, if the motion artifact when running is possible to be removed, the system will be able to perform monitoring of running men's states and especially emergency signals such as serious pulse waves of an/old and feeble persons and handicapped persons.

• Korean Journal of Applied Biomechanics
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• v.27 no.2
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• pp.109-116
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• 2017

Objective: This study aimed to investigate the relationship between leg stiffness and kinematic variables according to load while running. Method: Participants included eight healthy men (mean age, $22.75{\pm}1.16years$; mean height: $1.73{\pm}0.01m$; mean body weight, $71.37{\pm}5.50kg$) who ran with no load or a backpack loaded with 14.08% or 28.17% of their body weight. The analyzed variables included leg stiffness, ground contact time, center of gravity (COG) displacement and Y-axis velocity, lower-extremity joint angle (hip, knee, ankle), peak vertical force (PVF), and change in stance phase leg length. Results: Dimensionless leg stiffness increased significantly with increasing load during running, which was the result of increased PVF and contact time due to decreased leg lengths and COG displacement and velocity. Leg length and leg stiffness showed a negative correlation (r = -.902, $R^2=0.814$). COG velocity showed a similar correlation with COG displacement (r = .408, $R^2=.166$) and contact time (r = -.455, $R^2=.207$). Conclusion: Dimensionless leg stiffness increased during running with a load. In this investigation, leg stiffness due to load increased was most closely related to the PVF, knee joint angle, and change in stance phase leg length. However, leg stiffness was unaffected by change in contact time, COG velocity, and COG displacement.

• The Journal of Fisheries Business Administration
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• v.47 no.3
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• pp.35-52
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• 2016

This paper analyzed economic feasibility of aquacultural construction which of large-scale. The results of the economic analysis, cage cultural and water recycling cultural by post-water treatment were analyzed that NPV is 2,083,685 thousand won and -14,105,896 thousand won and B/C ratio is 0.590 and 0.855, respectively. These were shown economic infeasibility. But, running water culture by pre-water treatment(small scale) and running water culture by pre-water treatment(large scale) were analyzed that the one is 5,555,747 thousand won and 15,048,589 thousand won and the other is 1,154 and 1,1221, respectively. these were shown economic feasibility. In addition, measurement of B/C ratio through a sensitivity analysis on running water cultural by pre-water treatment(small scale) and running water cultural by pre-water treatment(large scale) is economic feasibility in all cases. However, these were analyzed when the selling price was falling to 20 percent, it has shown economic infeasibility and when the selling price rises to 20 percent, water recycling culture by post-water treatment has economic feasibility. The significance of the study analyzed a sensibility as well as economic feasibility by methods and scales. It is expected that used as basic materials when constructing and operating of land aquaculture in order to minimize the damage from natural disasters.

• Journal of the Korea Institute of Military Science and Technology
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• v.19 no.3
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• pp.395-403
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• 2016

A cylinder-type underwater vehicle for military use that is running near the free surface at the final homing stage to hit a surface ship target is affected by wave force and moment. Since wave can affect an underwater vehicle running at the depth less than half of the modal wave length, it is important to confirm that the underwater vehicle can work well in such a situation. In this paper, wave force and moment per unit wave amplitude depending on wave frequency, wave direction, and vehicle's running depth were calculated by 3-Dimensional panel method, and the numerical results were modeled in external force terms of six degrees of freedom equations of motion. Motion simulation of the underwater vehicle running in various speed, depth, and sea state were performed.

• Proceedings of the KSR Conference
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• 2011.10a
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• pp.1914-1921
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• 2011

When a railway vehicle passes through curves & transitions, the running speed must be improved by proposing the standards on the maximum running possibility speed of each section on conventional line (Dongdaegoo-Namsunghyun) considering derailment safety. In this paper, To improve the maximum running possibility speed of railway vehicle which passes through curves which have high risk of derailment, the track alignment conditions of conventional line (Dongdaegoo-Namsunghyun) that present transition curve length in current railway construction regulations are controlled. We presented elevation way about the section maximum running possibility speed in conventional line by analysis result.

• Journal of Aerospace System Engineering
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• v.4 no.2
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• pp.26-31
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• 2010

Reduction of the aerodynamic drag is one of the most hot issues of car industries. Many researchers have studied in the area of drag reduction methodology using experimental tools or numerical tools. In general, car shape design is the main focus to reduce the drag in aerodynamic research area. However, not many people have studied the aerodynamic interference between running cars to figure out the drag variation. In this research, the aerodynamic interference between two running cars have been analyzed by using numerical tools, FLUENT 6.2. Several different models of cars and two different distances between two running cars are considered.