• Journal of Korean Society of Forest Science
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• v.97 no.4
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• pp.445-451
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• 2008

This study was carried out to develop Tablet PC based customizing system for fine mapping of forest cover type. The major contents and characteristics of FIS developed in this study were as follows. Field Investigation System (FIS) has a merit of accessibility to display exact location in various spatial data with position information received from the GPS. FIS can be used to record and manage many field information on which field investigation is done, with the help of the memo tool, field-sheet tool, calculating distance and area with measuring tool as well as editing forest type. It is possible to do field investigation effectively using FIS developed in this study. Accordingly, investigation and time costs can be reduced and field-work productivity will be improved.

• Journal of the Korea Convergence Society
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• v.6 no.5
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• pp.85-90
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• 2015

In this study, the life evaluation due to the structural configuration of bumper attached at the front side of ATV vehicle is studied on the basis of fatigue analysis. As the purpose of this study, the characteristic of bumper exposed on the repetitive loading condition like the vibration is understood. The position of crack happened at the fatigue situation is grasped in advance and complemented in advance. It is considered that the multipurpose vehicle is designed to not be driven on the paved general road but the rough road like the unpaved load. And the weak part of bumper is understood through the study of life evaluation on this driving environment. The durability can be improved by doing the safe design of automotive bumper on the basis of the analysis result. And it is possible to be grafted onto the convergence technique at design and show the esthetic sense.

• Journal of Biosystems Engineering
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• v.42 no.4
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• pp.251-257
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• 2017

Purpose: A chisel mounted on working implement, such as agricultural machinery used in irregular farming conditions, is subjected to highly variable fatigue loading during work. To ensure the safety of the chisel on a working implement for the duration of its service life, fatigue testing must be performed with the proper fatigue test load conditions. In this study, working loads for a chisel were developed by reconstructing loads from strain gage data collected during field tests and used to conduct fatigue tests on the chisel component. Methods: FE analysis with nCode software was utilized to select the proper quantity and locations of strain gages for load measurements. A fatigue test was performed to experimentally verify the fatigue strength of the chisel and to evaluate the validity of the load history developed with the load reconstruction technique. Results: A strain history for the chisel was obtained from data collected during field tests. The data was filtered for the 14-16 km/h speed range, connected, and merged. The chisel load history was developed using the load reconstruction technique. The resulting load history was expressed as a load spectrum using the rain-flow counting method. Conclusions: A fatigue test was conducted on a chisel under a constant load condition with an equivalent load amplitude and number of cycles, as calculated by Miner's Rule for linear damage accumulation. During the fatigue test, there were no cracks at any position. It is concluded that the fatigue test method proposed in this study can be utilized successfully as a durability evaluation method for the chisel.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.10 no.11
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• pp.3066-3073
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• 2009

Joint paths of master and branch pipes are induced mathematically for many kinds of joint patterns between both pipes in 3-axis pipe profile-cutting machines. By compensating them with a kerf width, the real cutting paths are determined, and their CL-data are generated, and the tool paths generated by CL-data are verified by a ghost function. A bevelling of welds is implemented through tilting a cutting torch in the $\beta$-axis direction for 8 sections in the chuck rotation of $\alpha$-axis. A PLC controls simultaneously position and velocity in a real time for $\alpha$, X, $\beta$-axis by loading CL-data generated. We developed the PLC-controlled 3-axis pipe profile-cutting system which can cut a master or branch pipe along the cutting path and simultaneously do a bevelling process.

• Journal of Navigation and Port Research
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• v.30 no.8 s.114
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• pp.685-690
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• 2006

The rail clamp is the device to prevent that a crane slips along rails due to the wind blast as well as to locate the crane in the set position for loading and unloading containers. The wedge typed rail clamp should be designed to consider the structural stability and the durability because it compresses both rail side with large clamping force by the wedge working as the wind speed increases. In this research, the design of experiments(DOE) and the variation technology(VT) built in ANSYS WORKBENCH are utilized to determine the optimum shape of a jaw. The optimum results obtained by two methods are compared and examined.

• Journal of the Korea Society of Computer and Information
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• v.16 no.8
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• pp.147-155
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• 2011

Map rendering, positioning, database managements are key elements of location based services. Google map and GPS (Global Positioning System) have become a very popular solution for map rendering and positioning, respectively. They are very effective and yet free of charge. However, they cannot be used for an indoor location based service system. We cannot render a building drawing with Google map, we cannot determine a moving object's position when it is indoor. This paper introduces our web services of rendering drawings, indoor positioning, and multimedia contents up-loading and playing so that any programmers can use them in developing indoor location based service systems. In order to experimentally show the efficiency of our web services, we have built a location based contents displaying system for museum visitors with them.

• Journal of Korean Physical Therapy Science
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• v.13 no.4
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• pp.7-16
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• 2006

The purpose of this study was designed to find out the effectiveness of vertebral segment instability, muscle fatigue response on lumbar spine after apply lumbosacral stabilization exercise program to 4 patients with chronic low back pain and for 12 weeks. In this study, the lumbar spine motion with blind by MedX test machine and the difference of instability to lumbar vertebra segments in flexion, extension test of standing position and spinal load test(Matthiass Test) by Spinal Mouse. The stabilization exercise program was applied 2 times a week for 12 weeks in hospital and 2 times a day for 20 minutes at home. The results of the present study were as follows: 1. Instability test of lumbar vertebra segment is 2 type differential angle test between vertebrae segment and loading test of spine(matthiass) by Spinal Mouse. It appeared to improve stability of segments in sagittal plane after program. So lumbar spine curve increased lordosis toward anterior and was improved of the lumbar spine flexibility in flexion and extension. Specially, in matthiass test, ( - ) value was increased between lumbar vertebra segment when was the load on spine. And so stability improved after program. 2. Fatigue response test(FRT) results, in male, was raised muscle fatigue rate during increase weight, on the other hand female appeared lower than male. As a results, lumbosacral stabilization exercise was aided to improvement of lumbar spine vertebra segments stabilization. Spine instability patients will have a risk when in lifting a load or working with slight flexion posture during the daily of living life and it is probably to increase recurrence rate. Thus, not only lumbar extension muscle strength but also stability of vertebra segments in lumbar spine may be very important.

• Bulletin of the Society of Naval Architects of Korea
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• v.13 no.1
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• pp.17-23
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• 1976

Some methods of analysis of rectangular plates under distributed load of various intensity with interior supports are presented herein. Analysis of many structures such as bottom, side shell, and deck plate of ship hull and flat slab, with or without internal supports, Floor systems of bridges, included crthotropic bridges is a problem of plate with elastic supports or continuous edges. When the four edges of rectangular plate is simply supported, the double Fourier series solution developed by Navier can represent an exact result of this problem. If two opposite edges are simply supported, Levy's method is available to give an "exact" solution. When the loading condition and supporting condition of a plate does not fall into these cases, no simple analytic method seems to be feasible. Analysis of a simply supported rectangular plate under irregularly distributed loads of various intensity with internal supports is carried out by applying Navier solution well as the "Principle of Superposition." Finite difference technique is used to solve plates under irregularly distributed loads of various intensity with internal supports and with various boundary conditions. When finite difference technique is applied to the Lagrange's plate bending equation, any of fourth order derivative term in this equation produces at least five pivotal points leading to some troubles when the resulting linear algebraic equations are to be solved. This problem was solved by reducing the order of the derivatives to two: the fourth order partial differential equation with one dependent variable, namely deflection, is changed to an equivalent pair of second order partial differential equations with two dependent variables. Finite difference technique is then applied to transform these equations to a set of simultaneous linear algebraic equations. Principle of Superposition is then applied to handle the problems caused by concentrated loads and interior supports. This method can be used for the cases of plates under irregularly distributed loads of various intensity with arbitrary conditions such as elastic supports, or continuous edges with or without interior supports, and this method can also be solve the influence values of deflection, moment and etc. at arbitrary position of plates under the live load.

• Journal of the Society of Naval Architects of Korea
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• v.42 no.3
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• pp.259-267
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• 2005

The effects of hull flexibility on shaft alignment are growing as ship sizes are increased mainly for container carrier and LNG carrier. In order to consider hull flexibility on a propulsion shafting system, standardization of ship service conditions is necessary because hull deformation is continuously variable according to ship service conditions. How to summarize ship service conditions is suggested based on practically applicable four viewpoints : hull, engine, loading and sea status. Effects of the external forces acting on a ship propulsion shafting system are generally commented. Several design criteria regulated by classification societies are pointed at issue which seems to have Insufficient technical background. A qualitative verification is carried out to point out the invalidity of the assumption of effective supporting position. In this work, an elastic nonlinear multi-supporting bearing system is introduced as a key concept of the elastic shaft alignment. Hertz contact theory is proved to be more proper one than projected area method in calculation of the nonlinear elastic stiffness of the bearing, The squeezing and oil film pressure calculations in the long journal bearing like an after stern tube bearing are recognized as a necessary process for elastic shaft alignment design.

• Journal of the Ergonomics Society of Korea
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• v.30 no.5
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• pp.613-619
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• 2011

Objective: The purpose of this study is to compare the muscle activities of lumbar and lower extremity muscles between left and right sides using EMG(Electromyogram) when patients are transferred by physical therapists. Background: Asymmetrical lift was recognized as a major cause of musculoskeletal disorder. Several studies show that physical therapists' transferring patients needs caution as it could cause a lumbar pain to patients but there is not sufficient data to support. Method: Forty healthy rehabilitation hospital physical therapists joined for this study. The subjects were transferred from wheelchair to treatment mat(from left to right) by connecting the EMG device to the patients' body both on erector spine and rectus fermoris. At the moment when subjects were being transferred, the EMG device collected data from both erector spine and rectus femoris and it was normalized as %MVC. Then the EMG data was statistically analyzed using paired t-tests. Results: The EMG data show that the left erector spinae and rectus femoris are more activated than right erector spinae and rectus femoris in all position(p<.05) in a significant degree. Conclusion: The result implies that physical therapists' asymmetrical lifting when patients are transferred by them has a potential cause of musculoskeletal disorder of patients. Further studies will be conducted to find out a same tendency in other muscles of a body and to see if there are other factors to affect to patients during asymmetrical lifting. Application: These results can be used to provide baseline information for more understanding to asymmetrical lift loading.