• Proceedings of the KSR Conference
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• 2002.05a
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• pp.392-398
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• 2002

In this paper, an engineering database management system(EDMS) has been developed to support the system engineering for design of the high speed titling train to be put into the conventional lines. The developed system can be operated on client-server or web circumstances. To accomplish the concurrent engineering in design of the rolling stocks, this system has been fully equipped with a powerful viewer and a postprocessor for 3D CAD data or FE results. The system was tested using the engineering data produced during carrying out the G7 project to design KHST(Korean High Speed Train) in a crashworthy viewpoint. Through this example, it is shown that the system should be powerfully applied to improving the performance of the system engineering.

• Journal of the Korean Institute of Telematics and Electronics B
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• v.33B no.9
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• pp.124-134
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• 1996

Korean has a large set of characters, and has a two-dimensional formation: each character is composed of graphemes in two dimensions. Whereas connections between characters are rare, connections inside a grapheme and between graphemes happen frequently and these connections generate many cursive strokes. To deal with the large character set and the cursive strokes, using the graphemes as a recognition unit is an efffective approach, because it naturally accommodates the structural characteristics of the characters. In this paper, we propose a grapheme-based on-line recognition method for cursive korean characters. Our method uses a TDNN recognition engine to segment cursive strokes into graphemes and a graph-algorithmic postprocessor based on korean grapheme composition rule and viterbi search algorithm to find the best recognition score path. We experimented the method on freely hand-written charactes and obtained a recognition rate of 94.5%.

• Bulletin of the Society of Naval Architects of Korea
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• v.31 no.1
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• pp.22-25
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• 1994

종래의 재설계 방법으로는 시행착오 방법이 있다. (Fig. 1 참고). 이 방법은 설계자의 경험이나 직관 등에 의하여 설계를 변경한 후 다시 구조해석을 하여 재설계조건의 만족여부를 확인하는 방법이다. 이때 재설계조건을 만족하지 않을 경우 설계를 다시 바꾸고 구조해석으로 재설계조 건을 확인하여야 한다. 따라서 이 방법은 비효율적이고 설계조건에 쉽게 맞추기도 어렵다. 이러한 단점을 보완한 새로운 재설계방법으로 민감도 해석(Sensitivity Analysis)과 섭동법(Perturbation )에 의한 방법이 있다. 민감도 해석은 설계조건을 설계변수의 민감도로 나타내는 방법이고 섭동 법은 설계조건을 설계변수들의 함수로 나타내는 방법이다. 대형구조물의 구조해석과 구조설계 문제는 대부분 유한요소법에 의존한다. 따라서 이러한 대형구조물의 재설계 도구가 되기 위해서 쟤설계 프로그램은 유한요소해석 프로그램의 후처리 프로그램(Postprocessor)으로 개발되어야 한다. 이러한 전제조건 때문에 설계가 끝나고 유한요소해석을 행한 후 재설계를 하기 위해서 유한요소해석 모델을 사용하는 것이 바람직하다.

• The Transactions of the Korea Information Processing Society
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• v.7 no.8
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• pp.2400-2410
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• 2000

Many researches on recognition of Korean characters have been undertaken. But while the majority are done on Korean character recognition, tasks for developing document recognition system have seldom been challenged. In this paper, I designed a recognizer of Korean courtesy amounts to improve error correction in recognized character string. From the very first step of Korean character recognition, we face the enormous scale of data. We have 2350 characters in Korean. Almost the previous researches tried to recognize about 1000 frequently-used characters, but the recognition rates show under 80%. Therefore using these kinds of recognizers is not efficient, so we designed a statistical multiple recognizer which recognize 16 Korean characters used in courtesy amounts. By using multiple recognizer, we can prevent an increase of errors. For the Postprocessor of Korean courtesy amounts, we use the properties of Korean character strings. There are syntactic rules in character strings of Korean courtesy amounts. By using this property, we can correct errors in Korean courtesy amounts. This kind of error correction is restricted only to the Korean characters representing the unit of the amounts. The first candidate of Korean character recognizer show !!i.49% of recognition rate and up to the fourth candidate show 99.72%. For Korean character string which is postprocessed, recognizer of Korean courtesy amounts show 96.42% of reliability. In this paper, we suggest a method to improve the reliability of Korean courtesy amounts recognition by using the Korean character recognizer which recognize limited numbers of characters and the postprocessor which correct the errors in Korean character strings.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2008.05a
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• pp.632-635
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• 2008

Concurrent engineering concept is used in factory automation recently. In this paper, described instance that apply concurrent engineering production concept in sheet metal cutting process. Automation system to produce metal parts designed by Client/server structure, and designed NC postprocessor on inside. Also, in this paper, when handled all justices of part production by breakup design of concurrent engineering, proved can shorten tine required in product manufacture than system past.

• Transactions of Materials Processing
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• v.9 no.3
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• pp.233-241
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• 2000

It is well known that the quality and efficiency of the design of metal forming processes can be significantly improved with the aid of effective numerical simulations. In the present study, a two-and three-dimensional finite element simulation system, CAMP form, was developed for the analysis of metal forming processes in the PC environment. It is composed of a solver based on the thermo-rigid-viscoplastic approach and graphic user interface (GUI) based pre-and post-processors to be used for the effective description of forming conditions and graphic display of simulation results, respectively. In particular, in the case of CAMPform 2D (two-dimensional), as the solver contains an automatic remeshing module which determines the deformation step when remeshing is required and reconstructs the new mesh system, it is possible to carry out simulations automatically without any user intervention. Also, the forming analysis considers ductile fracture of the workpiece and wear of dies for better usage of the system. In the case of CAMPform 3D, general three-dimensional problems that involve complex die geometries and require remeshing can be analyzed, but full automation of simulations has yet to be achieved. In this paper, the overall structure and computational background of CAMPform will be briefly explained and analysis results of several forming processes will be shown. From the current results, it is construed that CAMPform can be used in providing useful information to assist the design of forming processes.

• Journal of the Korean Society for Precision Engineering
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• v.20 no.1
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• pp.205-213
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• 2003

The fiber reinforced composite material is widely used in the multi-industrial field where the weight reduction of the infrastructure is demanded because of their high specific modulus and specific strength. It has two main merits which are to cut down energy by reducing weight and to prevent explosive damage preceding to the sudden bursting which is generated by the pressure leakage condition. Therefore, Pressure vessels using this composite material in comparison with conventional metal vessels can be applied in the field such as defense industry, aerospace industry and rocket motor case where lightweight and the high pressure are demanded. In this paper, for nonlinear finite element analysis of E-glass/epoxy filament winding composite pressure vessel receiving an internal pressure, the standard interpretation model is developed by using the ANSYS, general commercial software, which is verified as the accuracy and useful characteristic of the solution based on Auto LISP and ANSYS APDL. Both the preprocessor for doing exclusive analysis of filament winding composite pressure vessel and postprocessor that simplifies result of analysis have been developed to help the design engineers.

• The Journal of the Acoustical Society of Korea
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• v.17 no.7
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• pp.50-56
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• 1998

본 논문은 자동 음소 분할기의 음소 경계 오류를 보상하기 위한 후처리 (Postprocessing)에 관한 연구이다. 이는 현재 음성 합성을 위한 음성/언어학적 연구, 운율 모델링, 합성단위 자동 생성 연구 등에 대량의 음소 단위 분절과 음소 레이블링된 데이터의 필요성에 따른 연구의 일환이다. 특히 수작업에 의한 분절 및 레이블링은 일관성의 유지가 어렵고 긴 시간이 소요되므로 자동 분절 기술이 더욱 중요시 되고 있다. 따라서, 본 논문은 자동 분절 경계의 오류 범위를 줄일 수 있는 후처리기를 제안하여 자동 분절 결과를 직접 합성 단위로 사용할 수 있고 대량의 합성용 운율 데이터 베이스 구축에 유용함을 기술한다. 제안된 후처리기는 수작업으로 조정된 데이터의 특징 벡터를 다층 신경회로망 (MLP:Multi-layer perceptron)을 통해 학습을 한 후, ETRI(Electronics and Telecommunication Research Institute)에서 개발된 음성 언어 번역 시스템을 이용한 자동 분절 결과와 후처리기인 MLP를 이용하여 새로운 음소 경계를 추출한다. 고립단어로 발성된 합성 데이터베이스에서 후처리기로 보정된 분절 결과는 음성 언어 번역 시스템의 분할율보 다 약 25%의 향상된 성능을 보였으며, 절대 오류(｜Hand label position-Auto label position ｜)는 약 39%가 향상되었다. 이는 MLP를 이용한 후처리기로 자동 분절 오류의 범위를 줄 일 수 있고, 대량의 합성용 운율 데이터 베이스 구축 및 합성 단위의 자동생성에 이용될 수 있음을 보이는 것이다.

• Transactions of the Korean Society of Automotive Engineers
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• v.10 no.5
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• pp.214-222
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• 2002

Computer simulations are widely used to analyze passenger safety in simulated traffic accidents. ATB, Articulated Total Body, is a computer simulation model developed to predict gross human body response to such dynamic environments as vehicle crashes and pilot ejections. ATB, whose code is open, has high flexibility and application capability that users can easily insert defined modules and functions. ATB is, however, inconvenient as it was coded in FORTRAN and it needs a formated input file. Moreover, it takes much time to make input files and to modify coding errors. This study aims to increase user friendliness by adding a preprocessor program, WINATB(WINdows ATB), to the conventional ATB. WINATB, programmed in Visual C＋＋ and OpenGL, uses ATB IV as a dynamic solver. The preprocessor helps users prepare input files through graphic interface and dialog box. An additional postprocessor makes the graphical presentation of simulated results. In these case of the frontal crash, the rear impact and the side impact, the simulation results obtained by WINATB and MADYMO(MAthematical Dynamic Model) are compared to validate the effectiveness of WINAIB.

• Korean Journal of Computational Design and Engineering
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• v.14 no.5
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• pp.291-296
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• 2009

This paper presents a post-processing algorithm for 5-axis machines with three rotary axes (3R-2L type). 5-axis machining needs the postprocessor for converting cutter location (CL) data to machine control (NC) data. The existing methods for post-processing use inverse kinematics equations from for-ward kinematics. However in case of 5-axis machines with three rotary axes, the inverse kinematics equations are not induced directly since the forward kinematics equations are non-linear. In order to get the joint values from the forward kinematics equations, previous algorithms use numerical method for the post-processing, which needs searching algorithms with computation time and may result in fail. This paper proposes a geometric method for the post-processing of 3 rotary type 5-axis machines. Our algorithm has three advantages: first, it does not need establishing forward kinematics equations. Second, it is reliable method that eliminates any numerical methods for the inverse kinematics, resulting in the exact solution. Finally, the proposed algorithm can also be applied to 2R-3L type of 5-axis machines.