• 한국기계연구소 소보
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• s.17
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• pp.99-109
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• 1987

Mechanisms with fully elastic members must consider both inertial forces due to the rigid motion of mechanisms and due to the elastic vibration of links. The main objectives of the kineto-elasto static and dynamic analyses are to calculate the quasi-static and the time-domain responses, respectively. An iterative transfer matrix method is used for a four-bar, fully elastic linked mechanism. Houbolt direct integration scheme is incorporated for the inertial effects due to the elastic link vibration. The analytical results are compared with the experimental responses and both responses show in good agreement.

• 제어로봇시스템학회:학술대회논문집
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• 1997.10a
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• pp.1613-1616
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• 1997

In order to develop a human hand mechanism, a 5-bar finger with redundant actuation is designed and implemented. an optimal set of acutator locations and link lengths for the case of one redundant actuator is obtained by employing a composite design index which simulataneously consider several performance indices such as workspace, isotropic index, and force transmission ratio. Each joing is driven by an compact actuator mechanism having ultrasonic motor and a gear set with poeneiometer an controlled by VME Bus-based control system.

• CDE review
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• v.22 no.2
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• pp.6-10
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• 2016

This paper presents the kinematics of a walking robot leg based on Jansen mechanism. By using simple mathematics, all trajectories of walking robot leg links can be calculated. A foot point trajectory is used to evaluate the performance of a walking robot leg. Trial and Error method is used to find a best combination of link lengths under certain restrictions. All simulations are performed by Matlab. Ground score, drag score, step size, foot lift, instant speed, and average speed of foot point trajectories are used for selecting the best one.

• Journal of Korean Society of Steel Construction
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• v.12 no.6
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• pp.715-725
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• 2000

As a link composition of a double link type level luffing jib crane was determinated through the link composition design, the design to be considered will be computations of the luffing trajectory deviation at the fly jib tip and the required luffing device capacity. This paper is a study regarding the static and dynamic analysis for a mechanism of the crane. The objective of the static analysis is to determinate the capacity and the dimension of luffing device when the crane selfload, rated hoisting load, wind load and inertia force are applied on the crane. The objective of dynamic analysis is to compute the luffing trajectory deviation, velocity and inertia force due to luffing acceleration for each link. All analyses are performed by computer programs. The reliability of the program was checked by results from analyses of the related commercial package. It is expected that the productivity and reliability of the design can be improved by this program which can rapidly and exactly deal with static and dynamic analysis for a given link composition of the crane.

• Journal of KSNVE
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• v.11 no.1
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• pp.125-131
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• 2001

There is a clearance between the parts of a machine due to design tolerance, manufacturing error, wear, looseness, or misalignment. If the clearance is large, the vibration and noise of the machine is generally large. Therefore, the analysis on the nitration and noise of a machine can tell the clearance of the machine, which reveals the condition of the machine, i.e., the existence of faults and the safety of the machine. The investigation of this kind of research should be on the basis of experimental results. A link mechanism with a clearance at a joint between the coupler and locker is made for the investigation of the condition monitoring of a machine due to clearance. The vibration and sound are measured from the link driving system during the operation. The signals are clarified using line enhancement technique. The noise removed signals are used to develop the dynamic model of the system for a model based fault diagnosis. Also this study showed that the clarified signals can be used for the calculation of the joint forces between the coupler and rocker and for the correlation between the vibration and sound levels and the clearance sizes.

• The Journal of Korea Robotics Society
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• v.5 no.4
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• pp.359-366
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• 2010

This study proposes the design method for the robot rotation arm which the end effector that is connected in end of the arm keeps parallel motion even though the robot arm rotates. So far, most robot arm rotates together the end effector when the arm rotates. For this, this study proposes the mechanism that the arm is linked to each 4 parallel link so that rotation is possible by 4 pins, and the rotation arm connects 2 joints of diagonal line direction to a link in each 4 joint for rotation, and designs so that can change length of the link. For verification of design, this study targeted that develop the rotation arm for medical examination that use in ophthalmology. It is important that a medical robot offers comport to patient and design compactly so that medical examination and treatment space may can be defined enough. It is designed so that all drive elements may be positioned on interior of the arm and optimization of design for main parts was carried out in this study for this. The robot arm which is developed in this study manufactured to use by medical phoropter arm, and got good result by an experiment. The robot rotation arm which is proposed in this study is judged to contribute very effectively in case use of a medical robot arm for medical examination and treatment, also the robot arm which the end effector that is connected in the end of the arm needs to keep parallel motion. And, the robot arm which is developed in this study made an application as license.

• Journal of the Korea Institute of Military Science and Technology
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• v.12 no.3
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• pp.259-265
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• 2009

In the traditional percussion locks of small arms, a firing pin is struck by a hammer rotating on a single center of rotation, which makes the percussion mechanism simple and reliable. In order to strike the firing pin by the hammer, however, the firing pin should be located within the radius of rotation of the hammer. As the distance between the striking point of the firing pin and the center of rotation of the hammer becomes longer, the radius of rotation of the hammer should also be increased, which results in the increase of the volume and weight of the small arms because the hammer needs the more space for its operation inside of the small arms. In this paper, a link type percussion lock was newly proposed in order to overcome the limitation of designing small arms when using traditional percussion locks, as mentioned above. The link type percussion lock was modeled by using multi-body dynamics software and designed to satisfy the requirements such as striking force level of the hammer exerting on the firing pin enough to detonate the percussion cap of ammunitions and the safety on the accidental drop. It was applied to the newly developed dual-barrel weapon system, in which the weight and overall length are important design factors, and verified by durability test and drop test on the ground.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.11 no.12
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• pp.5729-5744
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• 2017

Vehicular Ad Hoc Networks (VANET) in the large-scale road section usually have typical characteristics of large number of vehicles and unevenly distribution over geographic spaces. These two inherent characteristics lead to the unsatisfactory performance of VANETs. This poor performance is mainly due to fragile communication link and low dissemination efficiency. We propose a novel routing mechanism to address the issue in the paper, which includes a competition-based routing discovery with priority metrics and a local routing repair strategy. In the routing discovery stage, the algorithm uses adaptive scheme to select a stable route by the priorities of routing metrics, which are the length of each hop, as well as the residual lifetime of each link. Comparisons of different ratios over link length and link stability further show outstanding improvements. In the routing repair process, upstream and downstream nodes also compete for the right to establish repair process and to remain as a member of the active route after repair. Our simulation results confirm the improved performance of the proposed algorithm.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.19 no.5
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• pp.892-900
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• 1994

Recently, ITU-TSS recommends a service specific connection oriented protocol (SSCOP) which assures the successful transmission of signalling information for B-ISDN. In the SSCOP, there is a mechanism to exchange periodically status informations for both error and flow controls. In this paper, we analyze the SSCOP with a discrete-time queueing model. We consider two cases for link-by-link and end-to-end controls. As the performance measures, we investigate delay, throughput, and buffer size of the receiver. The average values of these measures are analyzed with respect to the loss probability of messages, the traffic load, and the exchange period of status information. We also verify the accuracy of this model with simulations.

• Steel and Composite Structures
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• v.12 no.1
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• pp.13-29
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• 2012

This paper is an experimental study on the behavior of vertical shear link in normal (steel section with and without stiffener) and composite (steel section with concrete located at the area limited to web and flanges of the section) configurations. This study is mainly aimed to perceive failure mechanism, collect laboratory data, and consider the effect of number of transverse reinforcements on strength and ductility of composite vertical links. There have been four specimens selected for examining the effects of different details. The first specimen was an I section with no stiffener, the second composed of I section with stiffeners provided according to AISC 2005. The third and fourth specimens were composed of I sections with reinforced concrete located at the area between its flanges and web. The tests carried out were of quasi-static type and conducted on full scale specimens. Experimental findings show remarkable increase in shear capacity and ductility of the composite links as compared to the normal specimens.