• Journal of the Korea Institute of Military Science and Technology
• /
• v.13 no.6
• /
• pp.967-975
• /
• 2010

There have been a lot of efforts on the improvement for the ride comfort and handling stability of the combat vehicles. Especially most of vehicles for military purpose have bad inertial condition and severe operating condition such as the rough road driving, and need a high mobility in the emergency status. It is necessary to apply the controlled suspension system in order to improve the vehicle mobile stability and ride comfort ability of crews. A feasibility study is performed on the application of the semi-active suspension system with a magneto-rheological controlled shock absorber for a $6{\times}6$ combat vehicle. First, the dynamic simulation model of the vehicle including the control model for the semi-active suspension system was executed. Based on this model, a hardware-in-the-loop simulation(HILS) system which has a semi-active suspension controller hardware was constructed. After full vehicle simulations were performed in virtual proving courses with this system, the semi-active suspension system was proven to give better ride comfort and handling stability in comparison with the conventional passive suspension system.

• Journal of the Korean Institute of Navigation
• /
• v.10 no.2
• /
• pp.83-96
• /
• 1986

In the restricted sea way such as fair way in harbor, narrow channel etc, the safe ship-handling is a very important problem, which is greatly related with turning ability of ships. It is of great importance that ship-handlers can grasp the position of pivoting point varying with time increase at any moment for relevant steering activities. Mean while, in advanced ship-building countries they study and investigated pivoting point related with turning characteristics, hut their main interest lies in ship design, not in safe ship controlling and maneuvering. In this regards it is the purpose of this paper to provide ship-handlers better under standing of pivoting point location together with turning characteristics and then to help them in safe ship-handling by presenting fact that pivoting points vary according to configuration of ships. The author calculated the variation of pivoting point as per time increase for various type of vessels, based on the hydrodynamic derivatives obtained at test of Davidson Laboratory of Stevens Institutes of Technology , New Jersey, U.S.A. The results were classified and investigated according to the magnitude of block coefficient , length-beam ratio, length-draft ratio, rudder area ratio ete, and undermentioned results were obtained. (1) The trajectory of pivoting point due to variation of rudder angle are all the same at any time, though the magenitude of turning circle are changed variously. (2) The moving of pivoting point is affected by the magnitude of block coefficient, length-beam ratio, length-draft ratio, however the effect by rudder area ratio might be disregarded. (3) In controlling and maneuvering of vessels in harbor, ship-handlers might regard that the pivoting point would be placed on 0.2~0.3L forward from center of gravity at initial stage. (4) The pivoting point of VLCC or container feeder vessels which have block coefficient more than 0.8 and length-beam ratio less than 6.5 are located on or over bow in the steady turning. (5) When a vessel intends to avoid some floating obstruction such as buoy forward around her eourse, the ship-handler might consider that the pivoting point would be close by bow in ballast condition and cloase by center of gravity in full-loaded condition.

• Journal of Convergence for Information Technology
• /
• v.7 no.6
• /
• pp.135-141
• /
• 2017

Recently, as elderly people suffering from chronic diseases have increased and disasters such as traffic accidents have increased, urgent rescue workers and doctors need to respond effectively to such emergencies. For elderly people, the difficulty in communicating their condition especially the health condition during disaster is one of the problems in which delay on immediate handling by rescue team can cause death. Providing a solution for this problem is one of the main issues in our research. In this paper, we use the QR code to communicate the minimum personal information and medical history needed for emergency medical treatment to emergency medical personnel, and to transmit the medical history and treatment data to the doctors of the hospital through QR code and fingerprint recognition, respectively. Especially, by using both QR code of smart phone and fingerprint of individual, we can protects personal information and strengthens privacy and security of medical information by allowing only authorized physicians to check medical records of the old patient.

• Proceedings of the Korean Institute of IIIuminating and Electrical Installation Engineers Conference
• /
• 2002.11a
• /
• pp.147-150
• /
• 2002

Domestic electrical construction inspection system was introduced into building site in 1963 by registered architects' law, meanwhile, inspector appointed by ministry of owners lake charge of Government managing building site. Afterwards several systems has been adopted to heal some problems each of them has revealed. These times Government granted authority for inspection on surveillancer, furthermore, formulate a supervising system which articulate the responsibilities of supervision and put it in effect as of 1st, January, 1994. This supervision system gets rid of factors causing faulty work to a considerable extent. However, as it is still in early stage, the system has various problems to overcome, For example, actual state of handling modifications of design in accordance with supervision system in field shows a difference between process provided by law and field process. Thus this study inquire and analyze actual condition of supervision system, at the same time, problems occuring in modifications of design under supervision, and then propose a way to improve it

• The Transactions of The Korean Institute of Electrical Engineers
• /
• v.57 no.10
• /
• pp.1790-1795
• /
• 2008

Energy scavenging is a technique that converts ambient energy, for example, vibration and light, to electrical energy in order to supply power to low power electronic devices such as ubiquitous sensors. In this paper, we propose an optimal operation condition of power delivery circuit and design strategy for energy scavenging system in which the generated power is order of microwatt and, consequently, efficient handling of power is critical. We also propose that high data transmission rate is more realistic optimal design objective rather than high energy efficiency. It is shown that disconnection of load from the storage capacitor right after data transmission reduces energy wasting and that optimal value of storage capacitor can be determined at this condition. The feasibility of our propose is proved by experiments and we believe that the proposed design strategy will promote the application of piezoelectric micropower generator to the ubiquitous sensor networks.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
• /
• 2001.11a
• /
• pp.450-454
• /
• 2001

The aim of the study is to develope an objective index for the evaluation of vehicle ride comfort using the measured vehicle accelerations. The equation of the index was derived from the correlation analysis of subjective ratings on selected vehicles and the reduced measure of the vehicle motions. First whole procedure of from the measurements to the calculation of the perceptual vibration was developed. Test condition of both the vehicle speed and the road condition was selected so as to maximize the reliability of the index. This paper suggested the equation of the objective ride index on vibration harshness, of which expected error is about 0.3 in 10 scale of subjective rating at 95％ of the significance level.

• Proceedings of the KIEE Conference
• /
• 2007.04a
• /
• pp.149-151
• /
• 2007

For several decades, VSC has gained much attention as one of the useful design tools for handling the practical system with uncertainties or disturbances. Generally, the disturbances in the matching condition can be perfectly rejected via VSC; however, these in the mismatching condition are known to be hardly rejected. There have been some trials on it, in which the resulting controls in fact belong to the class of robust control guaranteeing disturbance ${\gamma}$-attenuation. Therefore, in this paper, we propose a new Variable Structure Control (VSC) for a system with mismatched disturbances. The proposed controller is composed of linear and nonlinear parts; the former plays a role in stabilizing the system and the latter takes care of attenuating the disturbances. The main contribution is to introduce the concept of switching-zone, rather than switching-surface, that is designed through piece-wise Lyapunov functions. The resulting non-convex conditions are formulated with an iterative linear programming algorithm, which provides an excellent performance of almost rejecting the disturbances.

• Proceedings of the KSME Conference
• /
• 2003.11a
• /
• pp.1542-1547
• /
• 2003

Air entrainment can become a significant problem in a web handling process. The development of air film between a web and an idle roller can cause a reduction of traction and traction coefficient, by which a slip is occurrred. Computational and experimental study was carried out to describe the slippage of an idle roller for given operating conditions, tension and web velocity. An extended mathematical model to find out a slip condition was developed by using the models of air film height, dynamic traction coefficient, and torque balance of a rotational roller. And by using the extended model, a mechanism to define the slippage between the roller and the moving web was suggested. The results of simulation and experiment showed that the extended dynamic model could properly characterize the rotational motion of the idle roller by considering dynamic traction coefficient. By examining the rotational motion of the idle roller with web dynamics(speed), the mechanism to define al slip condition between the roller and the web was found to be effective.

• Journal of the Korean Society for Aviation and Aeronautics
• /
• v.7 no.1
• /
• pp.77-89
• /
• 1999

The atmosphere condition at Kimpo International Airport occasionally prevents the aircraft from landing and forces them to fly to an alternate airport, especially in October and November during a year. Many airlines designated foreign airports instead of Korean airports as alternate airports in the case of the bad weather condition preventing use of Kimpo Airport. This paper addresses 1) economic comparison of candidates for the alternate airport, 2) what are the criteria for the alternate airport selection and the relative importance among the criteria and 3) evaluation of candidates for alternate airport using Brown and Gibson's pair-wise comparison method. It is found to be possible to reduce costs related alternate flight by 36% using Korean airports rather than using Japan's Hukuoka Airport. However, airlines weigh more on the factors such as service level of ground handling, accommodation for passengers and ground access convenience than costs. Among Korean airports, Kimhae International Airport is found the most favorable airport as the alternate airport for Kimpo International Airport.

• Journal of the Semiconductor & Display Technology
• /
• v.6 no.1 s.18
• /
• pp.1-6
• /
• 2007

In order to raise productivity of the OLED and realization of the OLED TV, the enlargement of the mother glass substrate is required. The large-size glass substrate has some difficulties regarding its deflection during handling operation due to its thin thickness (0.5$\sim$0.7t) which is not even enough to stand its mass itself. This paper is demonstrating a new solution of this difficult through clamping and bending boundary condition, which helps to minimize the deflection of the glass substrate. Based on the developed method, the experiments had been done for verifying the proposed method to minimize the glass-deflection. With the developed method, the new design of glass substrate handler can be proposed to allow the large OLED displays be manufactured.