• 제목/요약/키워드: Cutting process model

검색결과 389건 처리시간 0.027초

연속 아연 도금 코-팅 두께에 관한 수치 해석적 연구 (A Numerical Analysis on the Coating Thickness in Continuous Hot-Dip Galvanizing)

  • 이동원;신승영;김병지;권영두;권순범
    • 대한기계학회:학술대회논문집
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    • 대한기계학회 2007년도 춘계학술대회B
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    • pp.2955-2960
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    • 2007
  • To control the coating thickness of zinc in the process of continuous hot-dip galvanizing, it is known from early day that the gas wiping through an air knife system is the most effective because of the obtainable of uniformity of coating thickness, possibility of thin coating, working ability in high speed and simplicity of control. But, the gas wiping using in the galvanizing process brings about a problem of splashing from the strip edge for a certain high speed of coating. And, it is known that the problem of splashing is caused mainly by the existence of separation bubble at the neighbor of the strip surface. In theses connections, in the present study, we proposed two kinds of air knife systems having the same expansion rate of nozzle, and the jet structures and coating thicknesses from a conventional and new proposed nozzles are compared. In numerical analysis, the governing equations consisted of two-dimensional time dependent Navier-Stokes equations, standard ${\kappa}-{\varepsilon}$ turbulence model to solve turbulence stress and so on are employed. As a result, it is found that it had better to use the constant rate nozzle from the point view of the energy saving to obtain the same coating thickness. Also, to reduce the size of separation bubble and to enhance the cutting ability at the strip, it is recommendable to use an air knife having the constant expansion rate nozzle.

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실시간 협업지원 그룹 ICN 에디터의 설계 및 구현 (Design and Implementation of A Real-time Collaborative Group ICN Editor)

  • 류재광;김광훈
    • 인터넷정보학회논문지
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    • 제2권5호
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    • pp.1-7
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    • 2001
  • 본 논문에서는 기업 내 사무업무 프로세스를 자동화하고 보다 효율적인 작업 환경 구축을 위하여 실시간 그룹 협업 지원 기술과 ICN 기반의 워크플로우 모델링 도구를 설계하고 구현한다. 모델링 도구는 그룹 단위의 실시간 협업 지원을 가능하게 하는 워크플로우 비즈니스 프로세스를 정의하므로 "그룹 ICN 에디터"라 부른다. 본 논문에서는 그룹 ICN 에디터가 여러 사용자가 동시에 작업이 가능하게 하기 위해 Flexible rJAMM을 이용하여 에디터를 구현한다. 에디터를 통하여 정의된 워크플로우 비즈니스 프로세스 모델들의 집합은 데이터베이스에 저장이 되고, WfMC에서 표준화한 워크플로우 프로세스 정의 언어(WPDL)로 변환되게 된다.로 변환되게 된다.

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연속 아연 도금 두께에 관한 수치 해석적 연구 (A NUMERICAL STUDY ON THE COATING THICKNESS IN CONTINUOUS HOT-DIP GALVANIZING)

  • 이동원;신승영;조태석;권영두;권순범
    • 한국전산유체공학회지
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    • 제14권1호
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    • pp.1-8
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    • 2009
  • To control the coating thickness of zinc in the process of continuous hot-dip galvanizing, it is known from early days that the gas wiping through an air knife system is the most effective because of the obtainable of uniformity of coating thickness, possibility of thin coating, working ability in high speed and simplicity of control. But, the gas wiping using in the galvanizing process brings about a problem of splashing from the strip edge for a certain high speed of coating. Also, it is known that the problem of splashing directly depends upon the galvanizing speed and nozzle stagnation pressure. In theses connections, in the present study, we proposed two kinds of air knife systems having the same expansion rate of nozzle, and the jet structures and coating thicknesses from a conventional and new proposed nozzles are compared. In numerical analysis, the governing equations consisted of two-dimensional time dependent Navier-Stokes equations, standard k-e turbulence model to solve turbulence stress and so on are employed. As a result, it is found that it had better to use the constant rate nozzle from the point view of the energy saving to obtain the same coating thickness. Also, to enhance the cutting ability at the strip, it is advisable to use an air knife with the constant expansion rate nozzle.

각주형 부품상의 가공 특징형상 인식 (Recognition of Machining Features on Prismatic Components)

  • 손영태;박면웅
    • 대한기계학회논문집
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    • 제17권6호
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    • pp.1412-1422
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    • 1993
  • 본 연구는 각주형 금형부품을 절삭가공할때 부품의 설계데이터로부터 부품의 형상적인 특징을 추출하여 공정설계시스템인 MOLDCAPP과 작업설계시스템인 COPS에서 사용할 수 있는 정보를 생성함으로써 CAD/CAM의 연결을 자동화할 수 있는 특징형상 인식 시스템을 개발하는 연구로, 특징형상 인식기법의 창안보다는, 가용한 기술의 장 점을 사용하여 각주형 공작물의 기계 절삭가공으로 생성될 수 있는 형상을 특징형상으 로 정의하고 ACIS로 설계된 CAD데이터로부터 정의된 특징형상을 추출하여 각 특징형상 들의 형상 데이터를 결정함으로써 MOLDCAPP, COPS 등의 공절설계시스템의 입력데이터 를 생성할 수 있도록 Fig.1과 같이 설계하였다. 특히 PART시스템과 같이 인식대상이 포괄적이지 않으나, 금형부품상의 특징형상으로 범위를 축소하고 금형부품의 가공특징 을 고려하여 인식규칙을 단순화함으로써 금형가공공정의 CAD/CAM연결에 이용될 수 있도록 하였다.

1D CNN 알고리즘 기반의 가속도 데이터를 이용한 머시닝 센터의 고장 분류 기법 연구 (A Study on Fault Classification of Machining Center using Acceleration Data Based on 1D CNN Algorithm)

  • 김지욱;장진석;양민석;강지헌;김건우;조용재;이재욱
    • 한국기계가공학회지
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    • 제18권9호
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    • pp.29-35
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    • 2019
  • The structure of the machinery industry due to the 4th industrial revolution is changing from precision and durability to intelligent and smart machinery through sensing and interconnection(IoT). There is a growing need for research on prognostics and health management(PHM) that can prevent abnormalities in processing machines and accurately predict and diagnose conditions. PHM is a technology that monitors the condition of a mechanical system, diagnoses signs of failure, and predicts the remaining life of the object. In this study, the vibration generated during machining is measured and a classification algorithm for normal and fault signals is developed. Arbitrary fault signal is collected by changing the conditions of un stable supply cutting oil and fixing jig. The signal processing is performed to apply the measured signal to the learning model. The sampling rate is changed for high speed operation and performed machine learning using raw signal without FFT. The fault classification algorithm for 1D convolution neural network composed of 2 convolution layers is developed.

CAD/CAM 밀링 시스템을 활용한 단일 치관과 3본 교의치의 3D 적합도 평가 (Three-dimensional evaluation of the internal adaptation of single and three-unit fixed dental restoration by CAD/CAM milling system)

  • 김소리;김총명;김웅철;김지환
    • 대한치과기공학회지
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    • 제39권1호
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    • pp.35-42
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    • 2017
  • Purpose: The purpose of this paper was to evaluate the occurrence of errors regarding adaptation by conducting a three-dimensional assessment comparing the bridge type dental restoration after the cutting process, which has multiple abutments, with a single type dental restoration. Methods: By using ten identical files obtained by scanning the master model, thirty designs were created consisting of ten maxillary right first premolars and ten maxillary right first molars with single crown abutments, along with ten bridge designs with the identical abutment. A 5-axis milling machine was used to produce the design file. The produced denture prostheses were scanned using a silicone replica for a STL file. An evaluation was conducted using 3D analysis software on the master model and each of the thirty data files. Results: The RMS value of the pre-molar (14) was $38.4{\pm}4{\mu}m$ for single and $54.7{\pm}6{\mu}m$ for bridge abutment; therefore, a statistically significant difference was observed for single and bridge designs although both shared the same abutment form (P<.05). Also, the RMS value of the molar (16) was $47.6{\pm}2{\mu}m$ and $56.6{\pm}5{\mu}m$ for the single and bridge designs, respectively, thereby presenting a statistically significant difference (P<.05). Conclusion: As a result, dental prosthesis fabricated using the single method presented better internal adaptation outcomes.

Experimental and numerical study on the stability of slurry shield tunneling in circular-gravel layer with different cover-span ratios

  • Liu, Xinrong;Liu, Dongshuang;Xiong, Fei;Han, Yafeng;Liu, Ronghan;Meng, Qingjun;Zhong, Zuliang;Chen, Qiang;Weng, Chengxian;Liu, Wenwu
    • Geomechanics and Engineering
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    • 제28권3호
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    • pp.265-281
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    • 2022
  • A set of slurry shield test system capable of cutter cutting and slurry automatic circulation is used to investigate the deformation characteristics, the evolution characteristics of support resistance and the distribution and evolution process of earth pressure during excavating and collapsing of slurry shield tunneling in circular-gravel layer. The influence of cover-span ratio on surface subsidence, support resistance and failure mode of excavation face is also discussed. Three-dimensional numerical calculations are performed to verify the reliability of the test results. The results show that, with the decrease of the supporting force of the excavation face, the surface subsidence goes through four stages: insensitivity, slow growth, rapid growth and stability. The influence of shield excavation on the axial earth pressure of the front soil is greater than that of the vertical earth pressure. When the support resistance of the excavation face decreases to the critical value, the soil in front of the excavation face collapses. The shape of the collapse is similar to that of a bucket. The ultimate support resistance increase with the increase of the cover-span ratio, however, the angle between the bottom of the collapsed body and the direction of the tunnel excavation axis when the excavation face is damaged increase first and then becomes stable. The surface settlement value and the range of settlement trough decrease with the increase of cover-span ratio. The numerical results are basically consistent with the model test results.

CJ CGV의 VRIO 모델을 통한 핵심역량분석 (An Analysis on the Core Competence Through the VRIO Model of CJ CGV)

  • 김은아
    • 한국엔터테인먼트산업학회논문지
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    • 제13권3호
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    • pp.333-342
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    • 2019
  • 본 연구의 목적은 CJ CGV, 롯데시네마, 메가박스의 멀티플렉스 영화산업에 관한 사례를 비교분석하여 경영전략관점에서 CJ CGV만의 혁신적인 핵심역량이 무엇인지 연구하는 데 있다. 이를 통해, 컬쳐플렉스의 확대과정을 바탕으로 주요 성공요소가 무엇인지 도출하고자 핵심역량 전략인 VRIO(Value, Rareness, Inimitability, Organization)모델 분석하였다. 분석결과, CJ CGV의 차별화된 가치로는 영화관의 문화놀이터인 컬쳐플렉스이고, 희소성에서는 영화관의 기술적 혁신을 통한 종합생활문화공간으로의 변신이며, 모방불가능성에는 사회공헌으로써 CGV의 사회적 브랜드파워 확립하였으며, 조직화하는데 전 세계의 CGV 글러벌화 등이 CJ CGV의 핵심역량으로 나왔음을 알 수 있다. 기존 영화관의 활용도를 넓혀 파격적이고 혁신적인 개발에 앞장서 CJ CGV는 문화 체험영화관의 브랜드 가치를 높이고 고객의 만족도를 높이는데 기여하고 있다. CJ CGV는 끊임없는 경쟁 지배력을 높여 CGV만의 핵심역량 기업 가치를 상승시키고 있는 것이다.

‘남자한복바지만들기’에 VTR을 활용한 가정과 교수.학습의 효과 (The Effect on Method of the Teaching & Learning Home Economics by the use of VTR on Making Korean Man’s Slacks)

  • 이정희;윤인경
    • 한국가정과교육학회지
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    • 제4권1호
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    • pp.87-95
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    • 1992
  • The purpose of this study is to suggest how we can get over the difficulties of practical drill under experimentation concerning the units of making clothes in the curriculum of home economics. The import of this study was based on the results of the preceding studies the field of the making Korean clothes, from the standpoint of the teaching tools and teaching materials by the use of VTR, is one of the most insufficient. On the one hand, the teaching procedure here a VTR, running 34 minutes or so, was made up with the process of making Korean men’s slacks, and was led by the researcher’s own. The contents of the lesson are as follows: the shape of Korean clothes, the name of each part, the process of drawing, cutting and sewing, and the items of evaluation and arrangement. On the other hand, the two comparative groups were made to compare one with the other: One group was taught by help of VTR media, and the other by the model performance and explanation of the instructor’s own. All of the statistical data were analyzed in terms of SPSS/PC, and t-verification was made, to make difference between the two, after standard deviation was calculated according to the classified domains. The consequences of the test research are shown as below: 1. The difference of understanding was obviously made in considering that the group made a better score than the comparative one in understanding to process of making Korean clothes. 2. The difference of skill was highly made in considering that the group made a better score than the comparative one in the practical drill of making Korean clothes. 3. The difference of interests was evidentally made in considering that the group made a better score than the comparative one in the stage of making Koran clothes. Such means that the motivation and attitude of the learners was made stimulate by the Audio-Visual material than by the traditional cramming method. 4. The difference of frequency was fairly made in considering that the experimeatal group made a better score than the comparative one in the frequency of individual teaching. 5. The difference of the efficiency of time-consumption was clearly made in considering that the experimental group made a better score than the comparative one. As the results of the research above, the medium of VTR proved to more effective to the achievement of schoolwork and the strategies of teaching. Therefore, more use of VTR media will help the instructors with the difficulties of practical drill in the whole process of making Korean clothes; Widely use of VTR media in teaching will be surely more fruitfull to the unit of making Korean clothes than teaching by explanation.

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"Belt and Road" and Arbitration Law Teaching and Education System Theory

  • Fuyong, Zhu
    • 한국중재학회지:중재연구
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    • 제30권3호
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    • pp.47-66
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    • 2020
  • Due to the division of China's departmental laws, the disconnect between theory and practice, and the influence of traditional academic thinking on the understanding of the knowledge structure of arbitration legal talents in practice, the construction of law school colleges, teaching teams, and research centers mostly revolves around departmental laws, tearing the connection of the arbitration legal system. The student-centered, process-guaranteed, and result-oriented arbitration master of law training model is "virtualized," the shaping of arbitration professionalism is ignored, the coverage of practical teaching is narrowed, and the arbitration legal profession is mostly formalized. The prevalence of specialized curriculum systems shortage, single faculty, formalized practical teaching, outdated curriculum settings, unsuitable curriculum system design for development, and inaccurate professional curriculum standards and positioning renders it difficult to integrate the "Belt and Road." The cutting-edge, the latest research results, and practical experience cannot reflect the connotation, goals, and requirements of "Entrepreneurship" education, as well as arbitral issues such as the ineffective monitoring of practical education and the inconsistent evaluation of standards and scales. Under the background of the "Belt and Road," based on system theory and practice and through training goals that innovate and initiate organizational form, activity content, management characteristics, assessment and support conditions, etc., the arbitration law teaching curriculum system is gradually improved and integrated. Through the establishment of a "Belt and Road" arbitration case file database and other measures, a complete arbitration law theory and practice teaching guarantee system has been established. Third parties are introduced, arbitration law experimental modules are developed, students are guided how to discover new knowledge, new contents are mastered, solidarity, cooperation, and problem-solving capabilities are cultivated in the practice of the "Belt and Road," and quality education, vocational education, and innovation education are organically integrated. In order to implement the requirements of arbitration law education, innovation development and collaborative management of arbitration law teaching practice base should be cultivated, thus giving full play to the effect of collaborative education between universities and arbitration institutions.