• Journal of computational fluids engineering
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• v.21 no.1
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• pp.78-85
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• 2016

While most AUV researches have concerned about single hydrofoil, practical AUV's are generally operated with multiple hydrofoils. Double hydrofoil study attempts to evaluate thrust and efficiency with various flapping motions, and carries out design optimization using parametric analysis. Flow patterns such as vortex shedding and wake-body interaction are carefully investigated during design variable sensitivity analysis. The purpose of this design optimization is to find out the optimal motion that yields maximum thrust and efficiency. The design optimization employes several techniques such as table of orthogonal arrays, Kriging method, ANOVA analysis and MGA. Throughout this research, it is possible to find the optimal values of heaving ratio, heaving shift and pitch shift: Heaving ratio 0.950, heaving shift $23.120^{\circ}$ and pitch shift $89.991^{\circ}$ are found to be optimal values in double hydrofoil motions. Thrust and efficiency are 16.7% and 35.1% higher than existing AUV that did not consider nonlinear dependency of motion parameters. This results may offer an effective framework that is applicable to various AUV motion analyses and designs.

• Proceedings of the Korean Magnestics Society Conference
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• 2008.12a
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• pp.28-28
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• 2008

• International Journal of Precision Engineering and Manufacturing
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• v.7 no.2
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• pp.3-7
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• 2006

We propose a new concept of transmission-tribology design based on the investigation of development and existing problems of the gear drive and tribology. The content of transmission-tribology and transmission-tribology design is probed. Some effective methods of transmission-tribology design is probed. Some effective methods of transmission-tribology design are put forward. Partial achievements in this research are introduced tersely. Mechanical transmission, which is represented by the gear drive, and tribology are two main branches of mechanical engineering. They have their own definite research field. In recent years, we have been doing our utmost to suggest combining mechanical transmission-tribology and transmission-tribology design. Partial achievements in this research area are obtained.

• Journal of Drive and Control
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• v.17 no.4
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• pp.97-102
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• 2020

This paper presents the basic research for the design and fabrication of a 3D-printed load cell made of NCPC (nano-carbon piezo-resistive composite). We designed a structure that can resonate at a low frequency range of about 5-6 Hz with ANSYS using sensitivity analysis and a response surface method. The design was verified by fabricating the device with a low-quality commercial 3D printer and ABS filament. We conducted a feasibility test for a commercial sensor using 1000 cyclic load tests at 0.3 Hz in a material testing system. A manufacturing process for the 3D printer filament based on the NCPC was also developed using the nano-composite process.

• 한국가스학회:학술대회논문집
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• 2007.04a
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• pp.18-23
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• 2007

• Advances in aircraft and spacecraft science
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• v.4 no.1
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• pp.65-80
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• 2017

Small aircrafts, Unmanned Aerial Vehicles (UAVs), are used especially for military purposes. Because landing fields are limited in rural and hilly places, take-off or landing distances are very important. In order to achieve a short landing or take-off distance many parameters have to be considered, for instance the design of aircrafts. Hence this paper represents a better design to enlarge the use of fixed wing aircrafts. The document is based on a live and simulated experiments. The various components of designed aircraft are enhanced to create short take-off distance, greater lift and airflow without the need for proper runway area. Therefore, created aerodynamics of the remotely piloted aircraft made it possible to use fixed wing aircrafts in rural areas.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2006.10a
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• pp.675-676
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• 2006

• Journal of the Korean Society for Precision Engineering
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• v.20 no.8
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• pp.126-134
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• 2003

In this study we do for the thing to develop automatic geometry design program of a mechanical element that we have used in CAD/CAM system. The program, which produces automatically three-dimensional surface and a solid model that have been used in CAD/CAM system, widely create automated two and three-dimensional model to by inputting several necessaries for a design, fur the design element. It is emphasized if you are just a beginner having only basic knowledge of the mechanical engineering, you might be able to design easily a three-dimensional model. The software to be used to develop automatic geometry design program is visualLISP to be a developer program of AutoCAD.

• Tribology and Lubricants
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• v.38 no.1
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• pp.1-7
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• 2022

Chemical-mechanical polishing (CMP) process is a semiconductor process that planarizes a wafer surface using mechanical friction between a polishing pad and a substrate surface during a specific chemical reaction. During the CMP process, polishing pad conditioning is applied to prevent the rapid degradation of the polishing quality caused by polishing pad glazing through repeated material removal processes. However, during the conditioning process, uneven wear on the polishing pad is inevitable because the disk on which diamond particles are electrodeposited is used. Therefore, the abrasion of the polishing pad should be considered not only for the variables during the conditioning process but also when designing the CMP conditioning system. In this study, three design variables of the conditioning system were analyzed, and the effect on the pad wear profile during conditioning was investigated. The three design variables considered in this study were the length of the conditioner arm, diameter of the conditioner disk, and distance between centers. The Taguchi method was used for the experimental design. The effect of the three design variables on pad wear and uniformity was assessed, and new variables used in conditioning system design were proposed.

• Korean Journal of Computational Design and Engineering
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• v.17 no.6
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• pp.398-408
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• 2012

This paper investigates the tolerance stack-up in a commercial sliding-type mobile phone model developed by a Korean electronics company, with focus on the dimensional quality of the gap between the sliding top and the main body. The tolerance analysis in this study is done using a commercial software package, which runs Monte Carlo simulations to produce the statistical distributions of the gap size at desired locations. Such an analysis revealed that the original design did not yield the desired dimensional quality of the gap. Through a series of systematic analyses and syntheses, an improved design is proposed for the nominal dimensions and tolerances of selected features of the parts. The proposed design was validated, through tolerance analysis simulation, to meet the desired requirement of the gap quality.