• Journal of Digital Convergence
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• v.13 no.6
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• pp.165-175
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• 2015

Methods to design programs which implement IT systems have been developed in various forms from flowchart to activity diagram of UML. However, program design tools and methods developed so far have not been efficient comparing to program coding tools and methods. In addition, Program design methods and tools developed until now have been difficult to support the bidirectional conversion between program design and coding, and the improvement of development productivity and maintainability. Therefore, in this study, we propose Convergence Development Method to enable working with wide bandwidth through fusing the program design and coding phase by using SOC and supporting tool named SETL which automatizes the convergence of design and coding. Thus, by using SETL, it is expected that the efficiency gap between the program design and coding phase is reduced, and development productivity and maintainability is increased. key words.

• Journal of Adhesion and Interface
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• v.17 no.3
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• pp.96-103
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• 2016

In this work, pellets consisting of cellulose-based natural fiber bamboo and poly(lactic acid) (PLA) was prepared by extrusion process and then bamboo fiber/PLA biocomposites with various fiber contents were produced by injection molding process. The water treatment effect of bamboo fibers on the flexural, tensile, and impact properties and heat deflection temperature of the biocomposites were investigated. The thermal stability of bamboo and the flexural properties, tensile modulus, and impact strength depended on the presence and absence of water treatment as well as on the fiber content, whereas the heat deflection temperature are influenced mainly by water treatment. The increase of the mechanical and impact properties of biocomposites is ascribed to the improvement of the interfacial adhesion between the bamboo fibers and the PLA matrix by the water treatment. The result suggests that the pre-treatment of natural fibers by using water, which is environment-friendly and labor-friendly, may contribute to enhancing the performance of biocomposites.

• Composites Research
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• v.20 no.5
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• pp.56-63
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• 2007

An approach using complex potentials is presented for analysis of composite plate with an elliptical hole or a rectilinear crack. Composite structure is susceptible to encounter impact damages, which lead to considerable decrease in its residual strength. Such impact damages could be modeled as an equivalent elliptical hole or notch-like crack. Even though finite element method is widely used to analyze stresses or fracture mechanics parameters around such damage, it is tedious to make successive FE-modeling for damage tolerance assessment under fatigue loadings. In this point of view, the solutions based on complex potentials are very simple and easy to use. The computed results are also compared and discussed with those from FEA.

• Korean Journal of Construction Engineering and Management
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• v.17 no.3
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• pp.71-80
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• 2016

PERT(Project Evaluation and Review Technique) is typical method in order to probabilistically establish the schedule plan for large scale complex project or mega project. PERT technique is impossible to estimate relationship of each activity probabilistically when there are overlapping relationships because it is limited to Finish-to-Start(FS) relationship. In order to overcome this kind of limitation of PERT technique, PLET(Probabilistic Linkage Evaluation Technique) has been suggested to probabilistically estimate project duration for various overlapping relationships for each activity. However, estimating project duration by PLET technique only considers uncertainty of relationship between activities and not activity time, thus it is not the perfect duration estimating method. The main objective of this research is to propose the integration model of PERT and PLET and verify its probabilistic validity. By verifying application of time calculation method of integration model in practical case, this research will suggest probabilistic project duration estimating method in schedule plan of high-risk construction industry.

• Korean Journal of Construction Engineering and Management
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• v.10 no.1
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• pp.91-101
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• 2009

The factors of uncertainty such as work delay could cause many problems, for example, increase of construction cost and terms of work, and the deterioration of quality. Because of these, the uncertainty risk is regarded as an important management factor to obtain the success of construction project. So, the systematic management plan about the uncertainty factors is needed because it plays an important role in the completion of entire project. And also analysis of some factors which can cause the work delay can be one way of improving construction project's certainty and making it competitive. In this reason, we have to make an effort to set a priority based on analysis of quantitatively numerical value about work delay factors to manage them effectively. Thus, this study aims to suggest the basic data for the effective management and prevention of work delay in steel-frame work which is progressive actively now, along with increasing of demand of high-rise buildings by analyzing each reasons of work delay factors and also by suggesting important management factors that are coded according to each construction work using FMEA method which could give a data about the importance of work delay factors through quantitatively numerical value.

• Journal of the Korea Convergence Society
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• v.9 no.11
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• pp.117-126
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• 2018

The purpose of this study was to examine the relationship between the working posture and symptoms of musculoskeletal disorders of dental hygienists during scaling. The subjects in this study were 264 selected dental hygienists. A convergence study was implemented using questionnaire that was prepared to cover general characteristics, health care, the work of scaling, working posture and subjective musculoskeletal symptoms. As for data analysis, R 2.15.1 was employed. As a result of analyzing the collected data, the rate of good working posture during scaling stood at 29.9 percent; roughly good posture, at 37.5 percent; incorrect posture, at 32.6 percent. Regarding the area of the body in which they complained of musculoskeletal symptoms, the shoulders were 3.32-fold more mentioned than any other area(OR,3.32;95%CI, 1.58~6.98); the foot, 2.97-fold more(OR,2.97;95%CI, 1.18~7.48); the hands, 2.84-fold more(OR,2.84:95%CI, 1.35~5.98); the neck, 2.82-fold more(OR, 2.82;95%CI, 1.35~5.91); the back, 2.41-fold more(OR,2.41;95%CI, 1.02~5.68). The findings of the study that demonstrate the importance of good working posture are expected to make a contribution to the improvement of work environments, the development of efficient preventive programs and the preparation of sustained educational plans, and it's necessary in the future to make a research study by including psychosocial factors.

• Journal of Digital Convergence
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• v.10 no.2
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• pp.231-235
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• 2012

Manufacturing Information System is a information system which supports the activities such as production planning, workflow management, work stage control. Manufacturing fields are showing new properties in today such as digital information, globalization, integration, to make sophisticated production. In this paper, we descibe major issues in current systems. Eventually, we propose major factors to adapt for new changes and BI systems to support manufacturing production information system based on the major factors.

• Journal of the Korean Society of Manufacturing Technology Engineers
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• v.5 no.2
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• pp.20-28
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• 1996

Compound surface modeling is widely used for die cavities and punches. A compound surface is defined in 3-D space by specifying the topological relationship of several anlytic surface elements and a sculptured surface. A constructive solid gemonetry scheme is employed to model the analytic compound surface. the desired compound surface can be accomplished by specifying topological reationship in terms of boolean relations between pimitives and the sculptured surfaces. Additionally, a method is presented for checking and avoiding the tool interference occuued in machining the compound surface. Using this method. the interference of concave, convex, and side region can be checked easily and avoided rpapidly.

• Proceedings of the Korea Concrete Institute Conference
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• 2010.05a
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• pp.423-424
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• 2010

This study purpose is to develop the high fireproof concrete which applied method of combined fiber mixed with polymer powder and organic fiber which can satisfy flowability and the fire resistance properties for construction of the super tall building. According to the results, in case of polymix it is effective to the reduction of internal temperature rise and spalling resistance so it as fire resistance that is similar to existing fiber cocktail.

• Proceedings of the Korean Institute of Intelligent Systems Conference
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• 2008.04a
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• pp.157-160
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• 2008

Multi-Spinner 장비는 반도체 제조공정과정 중 Photo공정에서 노광(Exposure)공정을 제외한 PR 형성공정 및 현상(Development)을 수행하는 복합적인 장비이다. 이 복합적인 Multi-Spinner 장비의 각 수행 과정에서는 웨이퍼를 이동 작업하는데 있어서 이동경로를 최적 스케줄링 한다면 반도체 생산량 향상에 크게 도움이 된다. Multi-Spinner 장비내의 각 공정과정들은 PR 형성공정 및 현상 공정 순서에 맞게 순차적으로 진행되며, 이 과정들을 위해 이송 로봇이 순차적으로 웨이퍼를 이동하며, 이 과정에서 일정의 대기시간이 발생하게 된다. 대기시간을 줄이기 위해 C/S 유닛에 담겨 있는 수십 장의 웨이퍼들을 다음 공정으로 이송 시 이동경로의 최적 스케줄링이 필요하다. 본 논문은 스케줄링 문제를 풀기 위해 인공 신경회로망(Artificial Neural Network)을 이용한 최적 스케줄링 방법을 제안한다.