• Proceedings of the Korean Society of Machine Tool Engineers Conference
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• 2003.04a
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• pp.488-493
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• 2003

This paper presents new skill in tube-mill processing getting the increase in production efficiency and quality in response to the recent request of high grade pipe. In this study, researchers developed the method to improve the precision of pipe and tool life in tube-mill processing. Optimum tool shape is devised by analyzing various simulation and mechanism in cutting process. In order to verify the confidence of the proposed machining technology, it is applied to the real processing machinery in the field.

• 제어로봇시스템학회:학술대회논문집
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• 2000.10a
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• pp.219-219
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• 2000

A Plate type pipe is used for heat exchange in radiator of a vehicle. The pipe has several rooms through which water flows and heat is dissipated into outside . In the case that there are small holes, cracks or some scratches on the plate, the radiators lost their functions due to Leakage. This may result in overheating of engine in a car. Thus, we need to perform the entire inspection of the plate type pipe in advance before assembling the radiator. In manufacturing process of the plate type pipe, the productive speed is very high and that may be performed continuously. So, there is no room to perform the outlook inspection by typical image processing techniques. This paper proposes a new method to inspect the outlook surface of the plate type pipe automatically with high speed. Especially, the sequential processing technique of an algorithm which detects defects on the surfaces of the plate type pipe is proposed for line scan camera which captures line image. To evaluate the inspection performance, a series of experiments is performed.

• Journal of the Korean Society of Safety
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• v.25 no.2
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• pp.7-11
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• 2010

Difficulties associated with full-scale pipe tests are rather obvious. That is, it is not only difficult to perform them but also very expensive and it requires lots of experience. And the process of the fracture test for the pipe specimen is very difficult and complicated. Because the pipe specimen, the test jig and the test equipment are very large and heavy, it requires lots of costs and times. In this study, to easily perform the fracture toughness test for a pipe specimen, load line displacement data was obtained using the image processing method.

• Journal of the Korean Society for Precision Engineering
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• v.31 no.7
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• pp.615-622
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• 2014

Copper pipes have been widely used as components of System Air-Conditioner due to high thermal conductivity. This system consists of 150 pipes, which are approximately 10m long in total. Dimensional changes occur during pipe processing such as expansion, reduction and bending. This processing induces changes in length of pipes and makes dimensional differences from original pipes. The summation of the differences of pipes components leads to make huge cumulative dimensional differences. The cumulative differences can cause serious problems such as crack, refrigerant leakage. However the differences have not been considered so far. To satisfy target quality of the system, it is essential to predict and calibrate the differences. In this paper, the changes in dimension were predicted using FEM and it was found that cumulative differences could cause indesirable stress during assembly process. As a result, dimensional differences or indesirable stress could be reduced using the proposed method.

• Transactions of Materials Processing
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• v.25 no.3
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• pp.176-181
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• 2016

The exhaust tail pipe is the only visible part of the exhaust system on a vehicle. The conventional way to make the tail pipe is welding after stamping. There are various problems that occur during the stamping of stainless steel sheets such as scratching and local fracture. Problems during welding can also occur due to poor weldability. Tube hydroforming can be a solution, which eliminates these problems. The current study deals with the development of tube hydroforming for a vehicle tail pipe using finite element analysis for a free-feeding method. The current study focuses on the development of a proper load path for the tail pipe hydroforming and how bending influences the subsequent processing steps. The FE analysis results were compared with experimental results. This study shows the importance of bending and the necessity of considering bending when performing a tube hydroforming analysis.

• Smart Structures and Systems
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• v.13 no.6
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• pp.1041-1063
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• 2014

This work introduces a two-module robotic pipe inspection system with ultrasonic NDE device to evaluate the integrity of pipe structures. The proposed robotic platform has high mobility. The two module mobile robot platform overcomes pipe obstacle structures such as elbow, or T-branch joints by cooperative maneuvers. Also, it can climb up the straight pipeline at a fast speed due to the wheel driven mechanism. For inspection of pipe structure, SH-waves generated by EMAT are applied with additional signal processing methods. A wavelet transform is implemented to extract a meaningful and specific signal from the superposed SH-wave signals. Intensity ratio which is normalized the defect signals intensity by the maximum intensity of directly transmitted signals in the wavelet transforms spectrum is applied to evaluate defects quantitatively. It is experimentally verified that the robotic ultrasonic inspection system with EMAT is capable of non-destructive inspection and evaluation of defects in pipe structure successfully by applying signal processing method based on wavelet transform.

• Transactions of Materials Processing
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• v.32 no.1
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• pp.5-11
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• 2023

The aim of this study is to manufacture an aluminum pipe yoke of automotive steering system for lightweight. In a multistage cold forging process for aluminum pipe yoke, the surface defects frequently occur due to excessive deformation or friction during extrusion process for forming hollow pipe part. It is import to reduce the friction between the material and the forging die. This study investigated a multistage forging process with sliding die to reduce friction for aluminum pipe yoke. After evaluating by FE analysis, the forging experiment with the sliding die was carried out. As a result, it was possible to manufacture a sound aluminum pipe yoke.

• Journal of the Institute of Electronics and Information Engineers
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• v.49 no.9
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• pp.196-204
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• 2012

Recently, many applications perform OLAP(On-Line Analytical Processing) over a very large volume of data. Multidimensional data cube is regarded as a core tool in OLAP analysis. This paper focuses on the method how to efficiently compute data cubes in parallel by using a popular parallel processing tool, MapReduce. We investigate efficient ways to implement PipeSort algorithm, a well-known data cube computation method, on the MapReduce framework. The PipeSort executes several (descendant) cuboids at the same time as a pipeline by scanning one (ancestor) cuboid once, which have the same sorting order. This paper proposed four ways implementing the pipeline of the PipeSort on the MapReduce framework which runs across 20 servers. Our experiments show that PipeMap-NoReduce algorithm outperforms the rest algorithms for high-dimensional data. On the contrary, Post-Pipe stands out above the others for low-dimensional data.

• Proceedings of the Korea Information Processing Society Conference
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• 2023.05a
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• pp.752-753
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• 2023

본 논문에서는 손가락 관절의 운동범위와 MediaPipe 손 추적기를 이용하여 3 차원 손 추적 방법을 설계하였다. MediaPipe 손 추적기가 추정한 신뢰할 수 있는 2 차원 좌표를 바탕으로 손 랜드마크의 깊이를 추정한 후, 손가락 관절 운동범위와 부합한 결과를 도출하였다. 본 논문에서 제안한 3 차원 손 추적 방법은 전용 하드웨어 없이 동작하며 기존의 3 차원 손 추적기에 비해 보다 직관적인 인간-컴퓨터 인터페이스 확산에 긍정적 영향을 줄 것으로 기대한다.

• Transactions of Materials Processing
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• v.24 no.5
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• pp.317-322
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• 2015

A process for the concurrent welding and extruding of pipe was designed for continuous production of fin tubes. Unlike a conventional pipe extrusion, the new process is able to extrude a pipe continuously without limit of length by using spring type wire material. The current paper provides the basic research for welding during the extrusion using a spring type wire material. The object of the current study is to investigate the possibility that the spring type wire material could be extrude into a welded pipe. The appropriate extrusion ratio was selected through investigation of loads using computer simulations. As a result, experiments showed that pipe could be welded and simultaneously extruded with spring type wire material of aluminum. The tensile strength of the welded and extruded aluminum pipe can reach 80% of tensile strength of original aluminum feedstock.