• Journal of the Korea Academia-Industrial cooperation Society
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• v.19 no.2
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• pp.644-652
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• 2018

This paper describes the conceptual design of a customized gripper for the assembly process of IT products, which has a relatively short and regular product replacement cycle. The grippers that are used in the manufacturing field are mostly composed of one to two degrees of freedom and they can only handle one object, not multiple ones. Cost is also an important factor. If it were possible to develop a gripper suitable for the assembly process quickly and easily, some of the difficulties involved in its automation caused by the frequent changes of product and process could be solved. The assembly process utilized for this research is defined and described as the procedure and method of the process analysis due to the confidentiality of the manufacturer. We used an axiomatic design to derive the functional requirements and design parameters of the gripper used for the tablet PC assembly process. We proposed a design method for the conceptual design of the gripper by determining these parameters. For the feasibility study, a specific process was selected and the progress of the gripper design was described as an example. Although there have been studies on the design guidelines for grippers, their considerations are too general and their degree of freedom is too high. This paper defines the function of the gripper based on the assembly process of the IT products, which allows their production to be streamlined and automated. In this research, we attempted to produce a design that reflects the assembly process, not just one that enables objects to be held.

• The Journal of Korea Robotics Society
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• v.9 no.1
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• pp.48-56
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• 2014

In robotic surgery, a surgeon checks only a surgical site of patient in the progress of surgery by vision and sound information. In order to solve this limited information, the haptic function is necessary. And haptic surgical robot is also necessary to design a haptic master device. The master device for laparoscope operation with cable-conduit was developed in previous research to give haptic function. It suggested a possibility of developing a master device by using the cable-conduit. However, it is very inconvenient to use. Therefore, this paper suggests a new mechanism design structure to solve the problems of the previous work by new forming a new master device. And it has proved that it's usability is better than previous one. Furthermore it has also experimented and analyzed that a backlash of new master device is compensated by smooth backlash inverse algorithm.

• Journal of Engineering Education Research
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• v.7 no.2
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• pp.40-50
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• 2004

To keep pace with rapidly changing social and technological trends, the Department of Mechanical and System Design Engineering at Hongik University is in the process of updating teaching materials and learning methodologies while evaluating/revising our existing curriculum. In order to be better apprised of the employment needs and student aspirations, we have conducted three separate but related surveys by targeting experienced professionals and managers, alumni working in industries as practising engineers, and our current students. The surveys have furnished us with valuable insights that, we hope, will lead to a new curriculum and learning methods more in tune with needs of our students as well as their future employers. Among other findings, the analysis of the survey responses points towards expansion of integrated laboratory and design experiences, cultivation of improved written and oral communication capabilities involving individual and team efforts, and development of interdisciplinary courses encompassing related fields of engineering as well as emerging fields such as nano and information technologies.

• International Journal of Fluid Machinery and Systems
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• v.10 no.1
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• pp.63-75
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• 2017

Many axial fans have circular arc blades with constant thickness. It is still a challenging task to calculate their performance, i.e. to predict how large their pressure rise and pressure losses are. For this task a need for cascade data exists. Therefore, the designer needs a method which works quickly for design purposes. In the present contribution a design method for such cascades consisting of circular arc blades with constant thickness is described. It is based on a singularity method which is combined with a CFD-data-based flow loss model. The flow loss model uses CFD-data to predict the total pressure losses. An interpolation method for the CFD-data are applied and described in detail. Data of measurements are used to validate the CFD-data and parameter variations are conducted. The parameter variations include the variation of the camber angle, pitch chord ratio and the Reynolds number. Additionally, flow patterns of two dimensional cascades consisting of circular arc blades with constant thickness are shown.

• Journal of the Korean Society of Systems Engineering
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• v.4 no.2
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• pp.1-13
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• 2008

The development of hull curved plate forming automation system in ship production field begins from the need of stakeholders such as enterprise organization, who need the reduction of cost and time and improvement of productivity, and end users who work for this production process. Even though hull curved plate forming automation system has small scale, it is reasonable to consider the system as an interdisciplinary system, because the system includes all of hardware, software, human and information and has a specified objective to be performed. In this paper, introduction of 4 leading Model-Based Systems Engineering (MBSE)methodologies is described and SysML(Systems Modeling Language), which is designed to analyze, specify, design, and verify complex systems, is introduced in order to support those methodologies. Especially, SysML is applied to system modeling of hull curved plate forming automation system and focused on. The structure diagrams and behavior diagrams based on operational context of the automation system are used to make system architecture. The performed application of SysML to the hull curved plate forming automation system shows an example of applying SysML to the development of other autonomous systems in ship production domain.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.35 no.6
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• pp.616-621
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• 2022

Numerical simulation is a good way to predict the conversion efficiency of solar cells without a direct experimentation and to achieve low cost and high efficiency through optimizing each step of solar cell fabrication. TOPCon industrial solar cells fabricated with n-type silicon wafers on a larger area have achieved a higher efficiency than p-type TOPCon solar cells. Electrical and optical losses of the front surface are the main factors limiting the efficiency of the solar cell. In this work, an optimization of boron-doped emitter surface and front electrodes through numerical simulation using "Griddler" is reported. Through the analysis of the results of simulation, it was confirmed that the emitter sheet resistance of 150 Ω/sq along the front electrodes having a finger width of 20 ㎛, and the number of finger lines ~130 for silicon wafer of M6 size is an optimized technology for the front emitter surface of the n-type TOPCon solar cells that can be developed.

• Journal of Biomedical Engineering Research
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• v.32 no.1
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• pp.32-36
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• 2011

The insufflators in endoscopic surgery supply carbon dioxide to make the air-filled cavity in the abdomen. It contains many kinds of pneumatic and electronic parts and they are connected with the air tubes and electrical wires. The printed circuit boards (PCB) perform wiring, holding and cooling tasks in electronic systems. In this study, the PCB is used as the air channel for insufflators to decrease the cost, volume, and the malfunction according to aging of the device. Three layers of PCB made of FR4 are combined with prepreg as adhesive which has the internal airway channel according to the design. By mounting the pressure sensors and valves, the PCB based fluidic system is implemented. After calibration of flow sensor, the flow rate of the gas also can be measured. The climate test, temperature test, and biocompatibility test showed this idea can be used in insufflators for laparoscopic surgery.

• Journal of the Korean Society for Precision Engineering
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• v.31 no.12
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• pp.1127-1132
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• 2014

Fast tool servo (FTS) is an enabling technology to fabricate various shapes of functional surface geometries in a precise and controllable manner. FTS can be also employed as a straightforward and efficient surface treatment way of making such products more durable. In this work, process characteristics using high-precision FTS-based surface texturing were qualitatively and quantitatively investigated to provide a class of surface design rule. The morphologies of surfaces processed with different conditions were first examined by observing the resultant 2D/3D surface profiles. In addition, the effects of the surface treatment using FTS on hardness and wear properties were characterized and compared to those without treatment.

• Proceedings of the KOSOMBE Conference
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• v.1998 no.11
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• pp.247-248
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• 1998

The effect of unattached valve leaflet on flow field downstream of a floating and flapping polyurethane heart valve prosthesis was investigated. With a triggering system and a time-delay circuit the instantaneous velocity field downstream of the valve was measured by particle image velocimetry (PIV) in conjunction with the opening posture of a flexible valve leaflet during a cardiac cycle. Reynolds shear stress distribution was calculated from the velocity fields and wall shear stress was directly measured by hot-film anemometry (HFA). The floating motion of the valve leaflet resulted in the reduction of pressure drop and recirculating flow region downstream of the valve.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.37 no.4
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• pp.323-329
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• 2013

This study attempts to simulate the structure of a woody leaf netted venation system by using topology optimization techniques. Based on finite element method (FEM) analysis of an incompressible fluid, a topology optimal design is applied to those woody leaf netted venation models. To solve the transverse shear locking problem of a thin plate caused by the Mindlin-Reissner plate model where a leaf netted venation is assumed to be a thin plate, a P1-nonconforming element and selective reduced integration are employed. Topology optimal design is applied to multiple physical domains. Combined with the Darcy-Stokes flow problems and extended to the optimal design of fluid channels, the multiple physical models of the flow system are analyzed and venation patterns of leafs are simulated. The calculated optimal shapes are compared with the natural shapes of woody leaf venation patterns. This interdisciplinary approach may improve our understanding of the leaf venation system.