• Journal of the Korean Society for Railway
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• v.12 no.3
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• pp.396-404
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• 2009

With developing the next generation high speed railway, there need to be plans to make sure of running safety though researchs on the crack and break of rail by rolling contact fatigue. Therefore, this study performed the parametric analysis effecting on the fatigue life of rail using simplified equations. It analyzed the internal stress of rail according to the track quality, train velocity, wheel radius, track stiffness, sleeper space, wheel load. For the more, via the finite element method, it analyzed shear force on the rail head which could be changed by the early length of crack, angle of crack and temperature. As a result, this study continued the main parameter effecting on the fatigue life of rail.

• Journal of the Institute of Convergence Signal Processing
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• v.5 no.1
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• pp.46-52
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• 2004

In this paper, we introduce a case study of developing a miniature humanoid robot which has 16 degrees of freedom, 42 cm heights, and 1.5kg weights. For easy implimentation, the integrated RC-servo motors are adopted as actuators and a digital camera is equipped on its head. So, it can transmit vision data to a remote host computer via wireless modem. The robot can perform staircase walking as well as straight walking and turning to any direction. The user-interface program running on the host computer contains a robot graphic simulator and a motion editor which are used to generate and verify the robot's walking motion. The experimental results show that the robot has various walking capability including straight walking, turning, and stairs walking.

• Journal of the Korean Society of Safety
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• v.34 no.2
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• pp.22-27
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• 2019

Bikers can be subjected to accidents during their bicycling. Helmets are only good, if any, for their head protection. A wearable airbag can protect the human neck area if it is properly designed. This airbag system is composed of an inflater and an airbag. The inflater contains a pressurized gas cylinder and a piercing device. The airbag is an inflatable fabric surrounding the human neck. When a bicycle accident happens, a sensor captures the motion of the biker and a microcomputer sends a signal to open a valve in the inflator to supply the pressurized gas to the airbag. An important issue of this system is that the airbag should be quickly inflated to protect the human neck. This paper deals with the airbag inflation time simulation and some issues to design a wearable airbag system. Also, a prototype was tested to show its feasibility using a human dummy mounted on a running cart.

• International Journal of Computer Science & Network Security
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• v.23 no.5
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• pp.7-12
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• 2023

Remote sensor systems are utilized in a few applications, including military, restorative, ecological and family unit. In every one of these applications, vitality use is the deciding component in the execution of wireless sensor systems. Thusly, strategies for information steering and exchanging to the base station are critical in light of the fact that the sensor hubs keep running on battery control and the vitality accessible for sensors is constrained. There are two explanations for the various leveled directing Low Energy Adaptive Clustering Hierarchy convention be in investigated. One, the sensor systems are thick and a considerable measure of excess is engaged with correspondence. Second, with a specific end goal to build the versatility of the sensor arrange remembering the security parts of correspondence. In this exploration paper usage of LEACH steering convention utilizing NS2 test system lastly upgraded vitality productive EE-LEACH directing convention guarantees that the chose cluster heads will be consistently conveyed over the system with a specific end goal to enhance the execution of the LEACH convention. EE-LEACH enhances vitality utilization by around 43%.

• Journal of the Korean Society for Marine Environment & Energy
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• v.12 no.4
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• pp.273-278
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• 2009

Overtopping Wave Energy Convertor (OWEC) is an offshore wave energy convertor for collecting the overtopping waves and converting the water pressure head into electric power through the hydro turbines installed in the vertical duct which is fixed in the sea bed. The numerical wave tank based on the commercial computational fluid dynamics code Fluent is established for the corresponding analysis. Several incident wave conditions and shape parameters of the overtopping device are calculated. The straight line type and parabolic type of the sloping arm are compared in the optimal designing investigation of the overtopping characteristics and discharge for OWEC device. The numerical results demonstrate that the parabolic sloping arm is available for wave running up and the overtopping discharge increasing.

• Development and Reproduction
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• v.21 no.3
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• pp.287-295
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• 2017

This study was conducted to observe egg and larvae morphological development of carp to obtain basic data for resource conservation and taxonomic research. Brood carp used in the research (total length 67.3-75.5 cm, average $71.0{\pm}3.45cm$) were bred in a circular rearing aquarium ($600{\times}300{\times}100cm$) using a running water system from January to July, 2015. Breeding water temperature was maintained at $23.0-25.0^{\circ}C$(average $24.0^{\circ}C$). Fertilized carp eggs were translucent and globular, and their size was 1.75-1.89 mm (average $1.82{\pm}0.06mm$). Blastoderms formed 10 min after fertilization and reached the two-cell stage 30 min after fertilization. Then, the embryo turned dark and exhibited melanophores, and blood started flowing from the heart across the egg yolk at 42 hrs and 50 min after fertilization. Hatching began 70 hrs and 26 min after fertilization larvae emerged through the egg membrane, starting from the head. The length of prelarvae immediately after hatching was 5.23-5.38 mm (average $5.31{\pm}0.11mm$) the mouth and anus were closed, and the pectoral fin was formed. Postlarvae at 18 days after hatching had a total length of 11.9-13.9 mm (average $12.9{\pm}1.40mm$), separate anal fin and back membranes, and fin ray. Juveniles fish at 35 days after hatching had a total length of 29.9-30.2 mm (average $30.1{\pm}0.13mm$), with the body covered with scales, and the same number of fin rays, color, and shape as their broodstork.

• The KIPS Transactions:PartB
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• v.10B no.4
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• pp.389-396
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• 2003

In this paper, we present a Korean partial parser based on rules, which is used for running applications such as a grammar checker and a machine translation. Basically partial parsers construct one or more morphemes and/or words into one syntactical unit, but not complete syntactic trees, and accomplish some additional operations for syntactical parsing. The system described in this paper adopts a set of about 140 manually-written rules for partial parsing. Each rule consists of conditional statements and action statement that defines which one is head node and also describes an additional action to do if necessary. To observe that this approach can improve the efficiency of overall processing, we make simple experiments. The experimental results have shown that the average number of edges generated in processing without the partial parser is about 2 times more than that with the partial parser.

• Journal of Advanced Marine Engineering and Technology
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• v.35 no.5
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• pp.566-575
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• 2011

Since LPG (Liquefied petroleum gas) fuel supply system has an advantage of low emission characteristics, many studies have been conducted. In spite of the advantage of LPG supply system, a higher vapor pressure and lower viscosity than diesel or gasoline fuel may cause unstable running of fuel pump by the deterioration in lubrication performance and chemical reaction with rubber parts than that of diesel and gasoline fuel. Therefore its physical properties can cause the deterioration of durability. In this research, we developed an external type LPG pump which has the advantage of the price competitiveness and the convenient maintenance for LPLi system. The experiments were carried out in order to assess characteristics of the external type fuel pump at different fuel composition and temperature. As a result, there aren't any differences between internal and external type pump performance. It is observed that the same level of efficiency was maintained for both pumps as flow rate was increased with higher fuel temperature and more contents of propane in the fuel. And the pressure difference in LPLi system is maintained at constant with the various fuel compositions and temperatures due to their own characteristics of fuel supply system.

• Journal of Preventive Medicine and Public Health
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• v.5 no.1
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• pp.105-110
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• 1972

On 6 healthy adult males aged 20-30 years, oxygen pulse was observed during carrying sand bags weighing 10, 20 and 30 kg on a level treadmill running with speeds of 3, 4 and 5 km/hr. The results obtained were as follows. 1. Oxygen pulse during load carrying on a level treadmill was proportionately increased with an increase of work load, average oxygen uptake per minute. Regression equation of oxygen pulse (y: $m\iota$/beat) on the average oxygen uptake (x:$\iota$/min) required for each grade of work was expressed as y=3.34x+5.99, $s_{y.x}=0.858$). 2. Oxygen pulse reached the highest value 2-5 minutes after the start of load carrying, and thereafter it decreased gradually to some extend as the load carrying was continued. Rate of decrease in the oxygen pulse was greater in lighter works. 3. In lighter works requiring less than $2.0\iota/min$ of oxygen uptake, no difference in oxygen pulse could be seen between methods of carrying even when the same amount of load was carried. In heavier works requiring more than $2.0\iota/min$ of oxygen uptake, oxygen pulse was larger in case of carrying a load by embrace, in both hands and on head than on back or on shoulder.

• Journal of the Korean Professional Engineers Association
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• v.17 no.3
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• pp.32-49
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• 1984

The East gate station area is 205M long and 24m deep which is located 13 meter in front of cultural treasure east gate. The area to be excavated by blasting is composed of granite rocks from 10M depth to 25M. Surface earth extends to up 10M depth. This job site has in involves heavy traffic congestion such as over 10,000 cars passing in rush hour where clossing No 1 lint of subway running 3 minitues head way. This east gate station construction is to be executed for the provent of the setting down of underground level and blasting vibration effects to cultural treasure east gate. Therefore, the caltural treasure committee approved this execution subject to the following condition. 1. Subway gelogical foundation and measured natural frequency 2. Execution of water tight wall 3. Sellection and test of damping material for wall and under rail 4. Measurement of monitoring system during the execution 5. Measurement of histogram system The above two projects was carried out by Dr. Kwang team in KAIST and prof, Han in Hanyang University under accadamic study contract. In the blasting work, for the pourpose of reduced vibration and low explosion velocity such as CCR, Kovex slurry. The 2nd, used electrical caps shall be delay cap and M/S caps in multi delay. The 3rd, drilling pattern is bench cut in open cut and applied control blasting in tunnelling and also shall drill anti-vibration holes as line drilling.