• Design & Manufacturing
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• v.9 no.1
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• pp.18-22
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• 2015

Mold making and product manufacturing process was made by a die through a number of stages. Thereby, it takes a long period of time from the manufacture of mold until passed the products to consumers. However, it is not possible to meet the diverse desires purchasing of consumer. We made a 3D CAD Model aligned with product scan data using reverse engineering. Utilizing thereafter flow analysis to derive the optimal mold conditions, by applying the condition, and devised a mold fabrication process that is much shorter than the conventional process for fabricating a mold. In this study, the outlet cover to the product, it describes a process, as a result, it was confirmed that the number of steps can be shortened much more than the conventional process.

• Proceedings of the Korean Society for Agricultural Machinery Conference
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• 2017.04a
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• pp.74-74
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• 2017

밀식파종 묘 이앙 시스템은 벼농사 생력화를 위한 재배법으로 비용 및 노동력을 획기적으로 줄일 수 있어 시간과 잉여 공간의 유효 활용을 통해 영농 규모의 확대로 인한 농업의 경쟁력을 높일 수 있다. 하지만 밀식 파종한 육묘를 관행과 동일한 1개 소당 3~4주 이앙 가능한 식부부 개발은 미흡한 실정이다. 밀식 파종한 육묘를 기존 이앙기로 이앙작업을 할 경우, 1개 소당 이앙되는 양이 많아져, 벼 생육을 저하 시키는 요인이 된다. 이러한 부분을 해결하기 위해서는 이앙 작업에 직접적으로 영향을 주는 이앙기식부부의 로터케이스, 이앙암을 분석하여 밀식파종 묘에 적용할 수 있는 기술이 필요한 실정이다. 본 연구에서는 식부부의 로터케이스, 이앙암을 3D 스캐너를 활용하여 스캐닝 작업을 한 뒤 역설계를 통하여 도면화 작업을 실시하여 식부부 궤적 분석을 실시하였다. 분석은 다물체 동역학 해석 프로그램인 Recurdyn(V8R4, Functionbay)을 활용하여 진행하였다. 분석결과, 식부부에 위치하는 이앙집게의 형상 및 로터케이스의 기어 배열에 따라 식부부가 형성하는 궤적의 형태가 달라지는 것을 확인 할 수 있었다. 이러한 부분은 밀식파종 묘에 적합한 궤적 분석 및 현장 필드 실험에 필요한 기초자료로 활용하고자 한다.

• Design & Manufacturing
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• v.6 no.1
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• pp.29-33
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• 2012

A 3D scanner scans and captures the shape of a real-world object. The captured shape can be used to construct three-dimensional model for CAD/CAM applications. In this study we have tried to design a cell phone cover by using the 3D scanner and reverse engineering. A 3D scanner is used to capture the shape of a cell phone. The 3D scanner generates a point cloud as the shape information. A three-dimensional CAD model for the cell phone is constructed from the point cloud. A cell phone cover is designed based on the CAD model of the cell phone. To check the integrity of this design process a prototype of the cover is made and assembled with the cell phone.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.35 no.10
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• pp.884-890
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• 2007

The procedure for the aerodynamic design of the rotor blades for 10 kW-level HAWT (horizontal axis wind turbine) has been investigated to be practiced systematically. The approximately optimal shape was designed using an inverse method based on the momentum theory and the blade element method. The configuration was tested in the wind tunnel of the Korea Air Force Academy, and the data was compared with those obtained from the real system manufactured from the present design. From this research, the authors established the systematic technolo for wind turbine blades, and set up the technical procedure which can be extended for the future design of middle and large sized wind turbines.

• Transactions of the Korean Society of Automotive Engineers
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• v.16 no.6
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• pp.10-18
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• 2008

Metal stamping is widely used in the mass-production process of the automobile industry. During the stamping process, air may be trapped between the draw die and the panel. The high pressure of trapped air induces imperfections on the panel surface and creates a situation where an extremely high tonnage of punch is required. To prevent these problems, many air ventilation holes are drilled through the draw die and the punch. The present work has developed a simplified mathematical formulation for computing the pressure of the air pocket based on the ideal gas law and isentropic relation. The pressure of the air pocket was compared to the results by the commercial CFD code, Fluent, and experiments. The present work also used the Bisection method to calculate the optimum cross-sectional area of the air ventilation holes, which did not make the pressure of the air pocket exceed the prescribed maximum value.

• The KSFM Journal of Fluid Machinery
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• v.18 no.1
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• pp.20-28
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• 2015

The pump-turbine impeller is the key component of pumped storage power plant. Current design methods of pump-turbine impeller are private and protected from public viewing. Generally, the design proceeds in two steps: the initial hydraulic design and optimization design to achieve a balanced performance between pump mode and turbine mode. In this study, the 3D inverse design method is used for the initial hydraulic impeller design. However, due to the special demand of high performance in both pump and reverse mode, the design method is insufficient. This study is carried out by modifying the geometrical parameters of the blade which have great influence and need special consideration in obtaining the high performance on the both modes, such as blade shape type at low pressure side (inlet of pump mode, outlet of turbine mode) and the blade lean at blade high pressure side (outlet of pump mode, inlet of turbine mode). The influence of the geometrical parameters on the performance characteristic is evaluated by CFD analysis which presents the efficiency and internal flow results. After these investigations of the geometrical parameters, the criteria of designing pump-turbine impeller blade low and high sides shape is achieved.

• Journal of the Korean Society for Precision Engineering
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• v.28 no.1
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• pp.80-88
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• 2011

The dental high-speed air turbine handpiece is one of the most popular devices that have been widely used as the main means of cutting tooth structure and restorative material in dentistry. In consideration of usage and marketability of the dental handpiece, it is obviously worthy of investigating it. The goal of this paper is to establish the relationship between the air turbine speed and the supply route inside the handpiece. To do this, the Computational Fluid Dynamics(CFD) tool, Fine$^{TM}$/Turbo is used and the optimal supply route position is suggested from the simulation results. In addition, as an attempt for domestic product, the reverse engineering process of a high speed dental handpiece by 3D X-Ray CT equipment and wire cutting is presented for the Mark II model in NSK. In doing so, the 3D modeling of the handpiece parts is carried out with CATIA V5, and the interference between parts is examined. Finally, the result of performance test for the prototype produced in this research is presented.

• Journal of the Korean Society of Manufacturing Technology Engineers
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• v.25 no.5
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• pp.393-399
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• 2016

In this study, an experiment was conducted using a 3D scanner, commonly used in reverse engineering techniques, and the newly introduced CT measuring machine. The hole, width, and angle of specimens having various shapes were designated, the error rates in dimensional modelling generated during scanning with each device were compared, and the models were printed using a 3D printer. A secondary comparative analysis of the two printed specimens was conducted; the causes of dimension errors that occur during the printing process after scanning with each device and the differences associated with variation in shape were also analyzed. Based on the analysis results, the featured shape for each scanning application method and issues to consider in reverse engineering were presented, and the use of the CT measuring machine was recommended as a method to minimize error rates in dimensions and ensure efficient reverse engineering.

• Journal of Physiology & Pathology in Korean Medicine
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• v.21 no.3
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• pp.583-590
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• 2007

The significance of Han medicine (韓醫學), the Korean traditional medicine, that has lasted throughout the past couple millenniums relies upon Han Philosophy distinguished by its uniqueness. In brief, the specificity of Han medicine is characterized by unity of spirit and body, part and whole. According to this theory, when curing a frozen shoulder, it is usually cured by acupuncturing the area around the part that aches, but also doing so on the area that is totally different from the aching part such as the opposite part of the body. In fact, this can be pursued only through aspects that enable one to realize the unity of part and whole, and a ground for this possibility bases upon the crux of Eastern Philosophy, I-ching(역), such as theory of Five Elements (음양오행) and Three Pillars(삼재). In Western set theory, the issues of Class(부류) and elements(요원), whole and part were independently discussed in the area of mereology, and the question of part and whole was encountered with aporia and paradox since Greek ancient philosophy. At the turn of this century, many philosophers endeavored to pursue academic inquiry to resolve this paradox, especially by Russell and Whitehead through ${\ll}$Principia Mathematica${\gg}$ at the beginning of this century. in the process, there came out a phrase 'Russell's Paradox'. Russell himself proposed a typological resolution as an answer to the inquiry. However, 'Russell's Paradox' still remains as an aporia even till present days. During medieval period, this inquiry was even considered as 'insolubia'. Throughout this paper, 1 attempt to provide an analytic aspect on 'Russell's Paradox' from an unique thinking method and perspective of Han medicine that embodies the concept of 'unity of part and whole'. To do so, 1 suggest a physiological model in the first place depicted by diagrams of Circle 원, Quadrangle 방, Triangle 각(CQT) that portray the logic of Hado or Hotu 하도 which is 'the pattern from the river Ho'. That is to suggest that CQT원방각 of Hado can De a logical foundation that explains the notions of spirit (정신,뇌), internal organs(장부), and meridian system which functions as a solution to the question of 'Russell's Paradox'. There are precedent academic works examining the issue from philosophical aspect such as Sangil Kim's ${\ulcorner}$Han medicine과 러셀역설 해의${\lrcorner}$ Han Medicine and Resolution of Russell's Paradox(2005), and this analysis will further attempt to critically examine such works from a perspective of Han medicine.

• IE interfaces
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• v.25 no.1
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• pp.134-141
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• 2012

The steering gear box for mid-heavy duty electric vehicles are usually produced by only a few specialized companies. The special techniques, such as designing, producing and testing technology have been veiled. For this reason, steering gear boxes are imported from other country. The durability test with the electric vehicle which is satisfies the design parameters takes several years, and a prototype is installed in the real vehicle for the test. In this research, the steering gear box of the steering system was developed based on the reverse engineering and the testing methods and the steering gear box development process have been suggested. The prototype is also developed with the CAD and CAE tools. Developed steering gear box have been tested in torque tester and have satisfied requied torque. As a result, the process and testing methods studied in this research are useful in the development processes of electric vehicles steering system.