• 수산해양기술연구
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• 제56권2호
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• pp.147-154
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• 2020

The questionnaire survey was carried out to collect basic data to identify the cause of the risk that did not appear in the current data provided by the fishermen's occupational accidents of the National Federation of Fisheries Cooperative (NFFC) to the onsite specialist, such as a fishing master, chief engineer and fisher in stow net fishing vessel from June to July 2018. The results are as follows. A total of 134 cases were surveyed, including 53 cases in Yeosu, 44 cases in Mokpo, 30 cases in Boryeong and 7 cases in Gunsan. Approximately 60% of the respondents on board the stow net fishing vessel were more than 20 years old, and the boarding experience was seasoned and suitable for the respondents. In the 4M analysis by safety accident factor during fishing work, the mechanical factors included 51 cases (25.0%) of decrepit equipment or poor maintenance and 49 cases (24.0%) of systemic error of fishing equipment. The environmental factors exhibited 71 cases (33.5%) of poor communication by mixed manning of foreign fishermen and 63 cases (29.7%) of poor environment such as heavy weather etc. The human factors showed 78 cases (37.3%) of personnel's carelessness and 45 cases (21.5%) of unskillfulness of operating net and haulers. The management factors exhibited 59 cases (32.1%) of work practice of poor safety precautions and 56 cases (30.4%) of inadequacy of education on hazard factor. The results are expected to contribute to the creation of a safe operating environment for stow net fishery, such as a fisher boarding a stow net fishing vessel, enabling the analysis of major causes of working safety accidents by cause.

• Journal of Advanced Marine Engineering and Technology
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• 제23권4호
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• pp.488-503
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• 1999

The present paper considers the constraint effect on J-R curves under the two-parameter $J-A_2$ controlled crack growth within a certain amount of crack extension. Since the parameter $A_2$ in $J-A_2$ three-term solution is independent of applied loading under fully plasticity or large-scale defor-mation $A_2$ is a proper constraint parameter uring crack extension. Both J and $A_2$ are used to char-acterize the resistance curves of ductile crack growth using J as the loading level and $A_2$ are used to char-acterize the resistance curves of ductile crack growth using J as the loading level and A2 as a con-straint parameter. Approach of the constraint-corrected J-R curve is proposed and a procedure of transferring the J-R curves determined from standard ASTM procedure to non-standard speci-mens or real cracked structures is outlined. The test data(e.g. initiation toughness JIC and tearing modulus $T_R$) of Joyce and Link(Engineer-ing Fracture Mechanics 1997, 57(4) : 431-446) for single-edge notched bend[SENB] specimen with from shallow to deep cracks is employed to demonstrate the efficiency of the present approach. The variation of $J_{IC}$ and $T_R$ with the constraint parameter $A_2$ is obtained and a con-straint-corrected J-R curves is constructed for the test material of HY80 steel. Comparisons show that the predicted J-R curves can very well match with the experimental data for both deep and shallow cracked specimens over a reasonably large amount of crack extension. Finally the present constraint-corrected J-R curve is used to predict the crack growth resistance curves for different fracture specimens. over a reasonably large amount of crack extension. Finally the present constraint-corrected J-R curve is used to predict the crack growth resistance curves for different fracture specimens. The constraint effects of specimen types and specimen sizes on the J-R curves can be easily obtained from the constrain-corrected J-R curves.

• 전자공학회논문지SC
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• 제44권4호통권316호
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• pp.79-88
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• 2007

산업계에서 디바이스 제어 네트워크에 접속을 위한 기술과 인터넷을 통한 빌딩 자동화 시스템에 접속을 위한 기술의 수요가 커지고 있다. 이러한 기술에서는 디바이스 제어 네트워크와 인터넷 같은 데이터 네트워크의 통합과 광역 분산제어 시스템으로 조직화하느 것이 필요하며, 이는 VDN(virtual device network)라는 구조 하에서 실현될 수 있다 [1,2]. 디바이스 제어 네트워크와 데이터 네트워크의 내역은 그 응용의 차이 때문에 아주 다르다. 따라서 VDN의 구현을 위하여는 디바이스 제어 네트워크와 데이터 네트워크 간에 통신 프로토콜을 번역하고, 목적지로 정보를 효과적으로 송신할 수 있는 라우터가 필요하다. 이 논문은 VDN에 기반한 NCS(networked control system)의 개념을 제안하고 임베디드 시스템[3]을 이용하는 라우팅 알고리듬을 제안한다.

• The Journal of Advanced Prosthodontics
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• 제8권1호
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• pp.21-29
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• 2016

This in vitro study investigated and compared the durability and retention of three types of attachments. MATERIALS AND METHODS. Three commercially available attachments were investigated: $Clix^{(R)}$, Dalbo-$Plus^{(R)}$ and $Locator^{(R)}$. In total, 72 samples of these attachments were placed in the acrylic resin forms and subjected to mechanical testing (5400 cycles of insertion and removal) over the respective ball or Locator abutments immersed in artificial saliva at pH 7 and $37^{\circ}C$. The abutments were placed at angulations of $0^{\circ}$, $10^{\circ}$ and $20^{\circ}$. The retention force was recorded at the beginning and after 540, 1080, 2160, 3240, 4320 and 5400 insertion-removal cycles. RESULTS. The results revealed that there were significant differences in the average values of the insertion/removal force due to angulation ($F_{(2.48)}=343619$, P<.05) and the type of attachment ($F_{(7.48)}=23.220$, P<.05). CONCLUSION. Greater angulation of the abutments was found to influence the retention capacity of the attachments, and the fatigue test simulating 5 years of denture insertion and removal did not produce wear in the metal abutments.

• 공학교육연구
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• 제21권6호
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• pp.3-12
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• 2018

The importance of software in the engineering field is increasing day by day, so the utilization and understanding of the simulation software in the engineering design stage has become the core competence of the engineer. This study presents a new software education method for multiple systems in the field of mechanical engineering using a workflow execution environment as a sub-module of a computational platform (called EDISON platform) that can incorporate in-house software tools developed by many simulation tool developers. It can execute not only individual software tools such as fluid flow, structure, optimal design, but also conduct connective executions of multiple software tools. Based on this simulation environment, a methodology was proposed that can be applied to convergence types of engineering educations. By properly using this methodology, it is expected that beginning engineers could encourage their specialties understanding the big pictures of the analysis processes.

• 한국산학기술학회논문지
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• 제20권7호
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• pp.166-172
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• 2019

금속 일체형 판재 도어 임팩트 빔 개발을 위해 단면 형상의 최적설계를 진행하였다. 기존의 도어 임팩트는 충격을 흡수하는 강관과 양쪽에 브라켓을 용접하여 자동차에 설치하는 구조로 이루어졌다. 하지만, 브라켓을 설치하기 위한 용접작업은 생산성을 떨어뜨리고 생산단가를 증가시키는 과정이다. 이러한 단점을 극복하기 위해 일체형 판재 도어 임팩트 빔의 개발은 반드시 필요한 공정이다. 본 논문에서는 일체형 판재 도어 임팩트의 단면 형상을 수치해석의 방법으로 제안하는 연구를 진행하였다. 외부 충격에 대한 반력 하중 및 생산성을 고려하여 엔지니어의 직관적인 설계 형상 6가지에 대하여 수치해석을 진행하였다. 객관적인 비교를 위해 3점 굽힘 하중 실험을 모사하는 유한요소해석을 진행하였다. 형상과 치수가 상이한 6가지의 단면 형상 중 최적의 형상을 선정하고, 상세 설계를 위해 단면형상의 높이와 폭의 치수를 변화시키며 해석을 진행하였다. 이를 통해, 일체형 판재 도어 임팩트의 최적의 단면 형상을 제안하였다.

• International Journal of Computer Science & Network Security
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• 제22권7호
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• pp.443-450
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• 2022

The method of studying 3D-technologies abroad and in Ukraine is considered. The analysis of educational resources and experience of use of the equipment in branch is carried out. The didactic principles of the educational process for 3D-printing specialists are determined. The use of FDM technology and the ability to minimize the occurrence of defects in the future have been studied. An analysis of the international experience of the educational process of relevant specialists in the field. The content of training for 3D printing specialists has been developed. The experience of using 3D-technologies is described and the list of recommendations for elimination of defects during production of products by means of additive technologies is made. The recommendations will be useful not only for beginners, but also for experienced professionals in additive technologies. The need to study such experience is the main condition for the development of enterprises in Ukraine that plan to automate their own production. A 3D printing engineer must know the basics of economics and marketing, because his responsibilities include optimizing workflows to reduce the cost and speed up printing. Therefore, the knowledge gained from practical experience presented and in building for learning 3D printing engineers by the authors will be important.

• 수산해양교육연구
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• 제14권2호
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• pp.229-248
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• 2002

The primary objective of this study is to firstly survey and analyze the working environment and actual condition, secondly know their problems, and then provide the basic data about how to improve their working conditions. The specific study items for getting the goal above is as follows: 1. How does the industrial company connect with highschool vocational education well? 2. How does the mechanical technical highschool graduate apply with industrial field? The result of study is as follows: 1. In case of employment's information and the industrial educationed cooperation, the workers who has the working history in less than 5 years takes short to find the job. National high school graduates and those who get the job through the school and the teacher changed their job at short period compared to other. 2. There was no benefit about the same major's worker at industrial field. The workers admitted that there is the exemption fo military service and the certification's allowance, only for which is related to their job. The longer the workers stay their job, the more they had the chance to get the exemption of military service. National highschool were carried out the curriculum well as planed especially for their major subjects. Whereas, the public and private highschools weren't. The seniors of their job and the coworkers are very helpful for learning the actual knowledge. The workers said that the school's curriculum and club activity weren't effective applying with their working field. 3. The study says that the important things of their job is the knowledge of their major. Those who 80% answered that the worker must improve the knowledge of their major to be a good engineer. Learning from their senior in working field was very helpful. The question above was ranked as the first. 4. The answer says that the new changed job's pay is more than the previous job. That is, the reason of leaving the job is the pay gap. The most dissatisfaction and problems in present job was the environment of working and the working condition. 5. Regarding to asking next year's plan, the answer says that keeping the job was ranked as the first. That answer means that they conservative.

• 실천공학교육논문지
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• 제12권1호
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• pp.203-212
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• 2020

본 연구는 제철산업학과 2015년에서 2019년 2월 졸업생 총 356명 중 취업자 244명을 대상으로 연구하였다. 졸업생의 주요 취업처인 포스코의 취업율은 67.7%, 현대제철은 23.8%, 포스코 계열사 13.1%, 현대제철 계열사는 8.5%로 조사되었다. 각 분야별 취득한 자격증은 금속 분야 53.1%, 기계 분야 39.8%, 기타분야 7.1%이다. 국가자격증의 종류와 분포는 포스코의 경우, 기계정비 산업기사, 제선 기능사 및 제강 기능사 순이며, 현대제철은 제강기능사, 제선 기능사 및 기계정비 산업기사 순으로 조사되었다. 이 외 기타분야의 자격증 중 산업안전 산업기사 국가자격증을 비중이 높은 것으로 나타났다. 취업자 1인당 평균 국가자격증의 수는 포스코 5.06개, 포스코 계열사 5.35개, 현대제철 5.29개, 현대제철 계열사 4.73개이다. S-오일, 한국전력, 풍산금속 등 기타 취업처의 평균 국가자격증 수는 2.51개로 나타났다. 본 연구를 통해 조사한 전공 관련 국가 자격증이 입사시 직무에 필요한 인재를 채용하고, 직무에 적합한 전공자를 발굴하는 데에 있어서 주요한 평가자료로 사용 된다는 결론을 얻었다.

• 한국재료학회지
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• 제1권3호
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• pp.156-167
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• 1991

본 연구의 목적은 항공기용 터어보팬 엔진의 재료선정을 위한 데이타 베이스를 구축하는 것이다. 터어보팬 엔진은 고성능이면서도 연료소모율이 적어 경제적인 운용이 가능하므로 최근 여러 용도로 사용되고 있는 엔진이다. 현재 서로 다른 특성을 가진 수백종의 초내열재료들이 개발되어 있는데, 한 엔진설계자가 어떤 엔진요소에 사용할 재료를 선택한다는 것은 매우 어려운 작업이다. 따라서 수 많은 재료에 대한 정보를 관리할 수 있는 데이타 베이스가 절실히 요구되고 있으나, 국내에서는 아직 이 방면의 기초연구가 이루어져 있지 않은 실정이다. 본 연구에서는 재료공학적 관점에서 초내열재료의 대표적 성질로서 고온강도, 내식성, 내산화성, 항복강도, 열팽창계수, 융정등을 고려해서 후보재료를 선정할 수 있도록 하였다. 이외에도 성 형성이나 제조단가등도 고려해야할 변수가 된다. 본 연구에 의해 사용자의 편의를 고려한 전산프로그램이 개발되었으며, 이를 이용하여 새로운 재료정보의 입력, 요구 재료선정 및 선정결과의 출력등이 가능하다. 끝으로 선정된 재료에 대한 성능검토도 실시하였다.