• International Journal of Concrete Structures and Materials
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• 제10권sup3호
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• pp.1-17
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• 2016

Recently, advanced transit systems are being constructed to reduce traffic congestions in metropolitan areas. For these projects, curved bridges with various curvatures are required. Many curved bridges in the past were constructed using aesthetically unpleasant straight beams with curved slabs or expensive curved steel box girders with curved slabs. Therefore, many recent studies have been performed to develop less expensive and very safe precast prestressed concrete (PSC) curved girder. One method of reducing the construction cost of a PSC curved girder is to use a reusable formwork that can easily be adjusted to change the curvature and length of a girder. A reusable and curvature/dimension adjustable formwork called Multi-tasking formwork is developed for constructing efficient precast PSC curved girders. With the Multi-tasking formwork, two 40 m precast PSC box girders with different curvatures were constructed to build a two-girder curved bridge for a static flexural test to evaluate its safety and serviceability performance. The static flexural test results showed that the initial cracking load was 1400 kN, exceeding the design cracking load of 450 kN. Also, the code allowed deflection of 50 mm occurred at a load of 1800 kN, verifying the safety and serviceability of the precast PSC curved bridge constructed using the multi-tasking formwork.

• 스마트미디어저널
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• 제9권1호
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• pp.16-22
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• 2020

본 연구에서는 Multi-Tasking U-net를 사용하여 영역 세분화 작업(Segmentation) 과 분류 작업(Classification) 이 동시에 수행되게 함으로써 파프리카 병과 충 진단을 수행하였다. 시설 농장의 파프리카에는 병의 종류가 다양하지 않다. 이 연구에서는 비교적 발생빈도가 높은 흰가루병과 응애에 의한 피해, 정상 잎 3개의 클래스에 대해서만 진단 할 수 있도록 하였다. 이를 위한 중추 모델로는 U-net을 사용하였다. 또, 이 모델의 Encoder와 Decoder의 최종 단을 활용하여 분류 작업과 영역 세분화 작업이 각 각 수행되게하여, U-net의 Encoder가 분류작업과 영역 세분화 작업에 공유되도록 하였다. 학습 데이터로는 정상 잎 680장, 응애에 의한 피해 잎 450장, 흰가루병 370장을 사용하였다. 테스트 데이터로는 정상 잎 130장, 응애에 의한 피해 잎 100장, 흰가루병 90장을 사용하였고, 이를 통한 테스트 결과로는 89%의 인식률을 얻었다.

• 한국정밀공학회지
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• 제29권2호
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• pp.129-138
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• 2012

In this study, three types of large scale multi-tasking machine tools together with core technologies involved have been developed and introduced; a multi-tasking machine tool for large scale marine engine crankshafts, a multi-tasking vertical lathe for windmill parts, and a large scale 5-axis machine tool of gantry type. Several special purpose devices has been necessarily developed for the purpose of handling and machining big and heavy workpieces accurately, such as PTD (Pin Turning Device) with revolving ring spindle for machining eccentric crankshaft pins, hydrostatic rotary table and steady rest for supporting and resting heavy workpieces, and 2-axis automatic swiveling head for high-quality free surface machining. Core technologies have been also developed and adopted on their detail design stage; 1) structural design optimization with FEM structural analysis, 2) theoretical hydrostatic analysis for the PTD and rotary table bearings, 3) box-in-box type cross-rail and octagonal ram design to secure machine rigidity and accuracy, 4) constant spindle rpm control against gravitational torque due to unbalanced workpiece.

• 대한기계학회:학술대회논문집
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• 대한기계학회 2007년도 춘계학술대회A
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• pp.1590-1594
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• 2007

This paper describes a case study on dynamic characteristics analysis of a 5-axis multi-tasking machine tool of ram-head typed. Natural frequency and corresponding vibration modes of the machine tool structure were obtained by using both FEM modal analysis and an experimental modal test(impulse hammer test). Both the theoretical and experiment analysis results showed good agreement with each other. Finally, some discussion and review, from the view point of resonance vibration and/or mode coupled chatter, were made based on the analysis results.

• Journal of Electrical Engineering and Technology
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• 제3권1호
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• pp.125-129
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• 2008

A new genetic algorithm for the solution of a multi-tasking problem is presented in this paper. The approach introduces innovative genetic operation that guides the genetic algorithm more directly towards better quality of the population. A wide variety of standard genetic parameters are explored, and results allow the comparison of performance for cases both with and without the new operator. The proposed algorithm improves the convergence speed by reducing the number of generations required to identify a near-optimal solution, significantly reducing the convergence time in each instance.

• 한국시뮬레이션학회논문지
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• 제3권2호
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• pp.69-76
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• 1994

Traditionally, simulation-based learning games which are known as flight-simulators have been constructed as a black-box game. Within a black-box game, game-players can view and modify only a part of model parameters. Game-players cannot change the structure of a simulation model. In a black-box game, game-players cannot understand and learn the system structure which is responsible for the system behavior. In this paper, the multi-tasking at the level of operating systems is exploited to enhance the transparency of simulation-based learning game. The white-box game or transparent-box game allows game-players ot view and modify the model structure. The multi-tasking solution for white-box learning game is implemented with Smalltalk language on MS-/windows operating system.

• 한국산업정보학회논문지
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• 제14권5호
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• pp.53-59
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• 2009

본 논문에서는 윈도우즈 운영체제 환경에서 다중 작업을 수행할 시 발생하는 문제점을 제시하고 이를 효율적으로 해결하기 위한 다중 윈도우즈 매니저를 제안한다. 본 논문에서 개발한 다중 윈도우즈 매니저는 3개의 윈도우즈 가상 화면을 사용하여, 윈도우즈 내에서 총 4개의 윈도우즈를 사용하는 것과 같은 효과를 볼 수 있으며, 이를 통해 다중 작업 시 발생하는 늦은 처리 속도와 높은 복잡도 문제를 개선할 수 있도록 한다.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2013년도 춘계학술대회 논문집
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• pp.535-536
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• 2013

• 한국정보처리학회논문지
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• 제5권11호
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• pp.2809-2822
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• 1998

GNARL은 GNAT Asa'95 컴파일러의 런타임 시스템으로, Ada'95언어의 멀티태스킹 기능의 지원을 담당한다. 공개 소프트웨어인 GNARL과 GNAT을 사용하면 프로그래밍언어, 컴파일러, 실시간 기능을 지원하는 런타임 시스템에 대한 연구를 자유롭게 수행 할 수 있는데, 본 연구에서는 GNARL과 GNAT의 총체적인 구조와 구현 원리 및 Asa'95의 멀티태스킹의 효율성, 예측성 및 안정성 향상에 대한 연구 결과에 대해 설명한다.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 1991년도 한국자동제어학술회의논문집(국제학술편); KOEX, Seoul; 22-24 Oct. 1991
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• pp.1915-1919
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• 1991

The efficiency of automated assembly line is increased by realizing the automation of each assembly cell, monitoring the line information and developing the real-time line control system it. which production flow is controllable. In this paper, the several modules which are important factors when constructing automated real-time control system, such as, line control S/W module, real-time model change module, error handling module and line production management S/W module, are developed. For developing these important programming modules, real-time control and multi-tasking techniques are integrated. In this paper, operating method of real-time line control in PCB automated assembly line is proposed and for effective control of production line by using multi-tasking technique, proper operating method for relating real-time line control with multi-tasking is proposed by defining the levels of signals and tasks. CIM-Oriented modular programming method considering expandability and flexibility will be added for further research in the future.