• 대한전자공학회논문지
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• 제27권9호
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• pp.1351-1363
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• 1990

In this paper, a reliable control system structured with dual CPU modules and dual I/O modules is implemented as a means of achieving a highly reliable fault tolerant control system. For this, faults in the system modules are first examined, and a fault detection technique consisting of self diagnostic, comparison process, and exception processing is applied. Self diagnostic is used to locate which components in the modules have been failed, while comparison process is to cmpare control outputs computed by both CPU modules and protect the plant from malfunction by blocking failed control outputsin advance. Finally exception processing is used to determine the faults that are not detected immediately by the self diagnostic and comparison process, e.g. bus error processing when acknowledge signal for data transfer is not activeted in the I/O modules. Also reliability analysis is conducted for the discrete time Markov model with dual structure. It is shown quantitatively that the reliability is improved in the control system with dual structure in comparison with a system with single module structure.

• 대한전기학회논문지:시스템및제어부문D
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• 제50권4호
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• pp.168-176
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• 2001

In this paper, we develop a dual-duplex system which detects a fault by hardware comparator and switches to hot standby redundancy. This system is designed on the basis of MC68000 and can be used in VMEbus. To improve reliability, the dual-duplex system is designed in dual modular redundancy. The failure rate of electrical element is calculated in MILSPEC-217F, and the system RAMS(Reliability, Availiability, Maintainability and Safety) and MTTF(Mean Time to Failure) are evaluated by Markov modeling method. As the evaluation result shows improved reliability, it can be used as a component hardware for a highly reliable control system.

• 실천공학교육논문지
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• 제5권2호
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• pp.139-149
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• 2013

본 논문에서는 한국기술교육대학교가 새롭게 제시하는 한국형 듀얼 시스템인 K-Dual 시스템의 개념과 세부모델들에 대해 제안하고 주요사항에 대해 논의한다. K-Dual 시스템은 기존의 우리나라에서 다양한 형태로 진행되어 오고 있는 일학습 병행관련 제도들의 문제점을 보완하고 이들을 하나의 시스템으로 통합 운영하기위해 한국의 실정에 맞게 대한민국 교육시스템에 적합하게 설계한 한국형 일학습 병행 모델로 크게 Academic 트랙과 Vocational 트랙의 2가지 트랙에 IPP, $W^3$ 및 기업대학형의 3가지 유형으로 정의된다. Academic 트랙의 경우에는 선진학 후취업 모델로 대학에 진학중인 학생들을 대상으로 현장실습교육을 강화함으로써 향후 취업 시 현장 적응력을 극대화시키고 취업과 연계하여 취업률 및 취업의 질/업무 만족도를 향상하고자 함에 그 목적이 있다. 반면 Vocational 트랙의 경우 기업체의 재직자를 대상으로 일정기간의 경력을 취득한 후 연계된 대학 또는 전문대학의 정규교과과정과 함께 일정한 산업체 현장실무/실습 교육(예, 기업체 멘토의 지도하에 진행되는 프로젝트 수행 등) 학점을 이수하면 대졸 또는 전문대졸 학위를 취득하는 형태(선취업 후진학 모형)로 교과과정은 대학과 기업체가 공동으로 설계 및 운영하게 된다. 본 논문에서 제안하는 K-Dual 시스템이 성공적으로 정착되어 운영되기 위해서는 무엇보다도 기업의 대학교육에 대한 적극적인 참여와 열린 마음가짐이 필요하며, 대학은 체계적인 학사시스템 설계 및 온/오프라인 교육센터 등 인프라 구축이 선행되어야 할 뿐만 아니라 정부도 참여기업 및 대학을 위한 제도적 재정적 지원을 아끼지 않아야 할 것이다.

• 한국환경과학회지
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• 제23권4호
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• pp.737-742
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• 2014

This study aimed for evaluating the applicability of the two stage dual media filtration system in field water treatment plant. The field plant of two stage and dual media filtration system was operated for 2 months. Average iron concentrations of the settled water, existing filtered water and second stage filtered water was 0.041 mg/L, 0.007 mg/L and 0.005 mg/L, respectively. Removal efficiency of iron concentration in the second stage is appropriately 35% more than in existing filtered water. Also removal efficiency of residual chlorine in the dual media filtration system is relatively 42.3% more than in existing filtered water due to adsorption of activated carbon, but the removal of ammonia nitrogen by adsorption is insufficient. Average concentrations of THM and chloroform in the settled water are 0.033 mg/L, 0.026 mg/L, respectively and in existing filtered water are 0.023 mg/L and 0.023 mg/L. Average concentrations of THM and chloroform in the dual media filtration system are 0.008 mg/L and 0.013 mg/L. Therefore removal efficiency of THM concentration in second stage is more than 66.4% in existing filtrated water. Also removal efficiency of chloroform in the dual media filtration system is more than 50.0% in existing filtered water because of the adsorption of activated carbon. In this case backwashing period in dual stage system is 4~5 days, but in existing filtration system is 1~2 days.

• 한국생물공학회:학술대회논문집
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• 한국생물공학회 2000년도 추계학술발표대회 및 bio-venture fair
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• pp.587-589
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• 2000

The production of inulooligosaccharides from inulin by a dual endoinulinase system of Pseudomonas sp and Xanthomonas sp. was investigated the optimum conditions for a dual endoinulinase reaction were as follows : pH,5.8; temperature, $50^{\circ}C$; substrate concentration, 50 g/l; enzyme ratio, 3:1 as Xanthomonas endoinulinase to Pseudomonas endoinulinase. Under optimum conditions, the maximum yield of oligosaccharides was 90.5% in total sugar basis by dual endoinulinase system

• 소음진동
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• 제7권6호
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• pp.1039-1048
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• 1997

This paper describes the effects of dual dynamic vibration absorbers attached to a primary vibration system with damping. The efficiency of dual dynamic vibration absorbers was investigated with the height of amplitude ratio at the resonance frequency ratio of the damped vibration system according to mass ratio, natural frequency ratio and damping ratio. The variation of amplitude ratio related to frequency ratio of primary vibration system is verified experimentally and theoretically according to dual dynamic vibration systems using computer program designed to find mutual relationship between two absorbers.

• 대한기계학회:학술대회논문집
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• 대한기계학회 2003년도 춘계학술대회
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• pp.1309-1314
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• 2003

The high precision positioning mechanism is used in various industrial fields. It is used in semiconductor manufacturing line, test instrument, Bioengineering, and MEMS and so on. This paper presents a positioning mechanism with dual servo system. Dual servo system consists of a coarse stage and a fine motion stage. The course stage is driven by VCM and the actuator of fine stage is the PZT. The purposes of dual servo system are stability, higher bandwidth, and robustness. Lead compensator is applied to this control system, and is designed by PQ method. Designed compensator can improve property of positioning mechanism.

• Steel and Composite Structures
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• 제37권4호
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• pp.447-462
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• 2020

In this paper, a simplified seismic design method for low-rise dual frame-steel plate shear wall (SPSW) structures is proposed in the framework of performance-based seismic design. The dynamic response of a low-rise structure is mainly dominated by the first-mode and the structural system can be simplified to an equivalent single degree-of-freedom (SDOF) oscillator. The dual frame-SPSW structure was decomposed into a frame system and a SPSW system and they were simplified to an equivalent F-SDOF (SDOF for frame) oscillator and an equivalent S-SDOF (SDOF for SPSW) oscillator, respectively. The analytical models of F-SDOF and S-SDOF oscillators were constructed based on the OpenSees platform. The equivalent SDOF oscillator (D-SDOF, dual SDOF) for the frame-SPSW system was developed by combining the F-SDOF and S-SDOF oscillators in parallel. By employing the lateral force resistance coefficients and seismic demands of D-SDOF oscillator, the design approach of SPSW systems was developed. A 7-story frame-SPSW system was adopted to verify the feasibility and demonstrate the design process of the simplified method. The results also show the seismic demands derived by the equivalent dual SDOF oscillator have a good consistence with that by the frame-SPSW structure.

• 한국군사과학기술학회지
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• 제21권3호
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• pp.331-341
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• 2018

This study proposes an integrated serial spring-damper mechanism as a dual pulse generation system. Compared to the traditional dual pulse generation system, which used multiple springs and a damper to generate a dual pulse critical for impact testing of naval equipments, currently used separated serial spring-damper mechanism is comprised of two components: an air spring, and a damper. The proposed mechanism combines the two components into one integrated system with a unique design that lets simply changing the volume and the pressure of the air tank, and the length of the annular pipe adjust the stiffness and damping constants for testing, eliminating the need to have multiple sets of air springs and dampers. Simulations using MatLab and Simulink were conducted to verify the feasibility of this design. The results show the potential of an integrated serial spring-damper mechanism as a more convenient and flexible mechanism for dual pulse generation system.

• 한국수학교육학회지시리즈C:초등수학교육
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• 제25권2호
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• pp.161-178
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• 2022

우리나라는 고유어 수사와 한자어 수사로 구성된 이중 수사 체계를 사용하고 있다. 이러한 이중 수사 체계는 실생활에서 관습적으로 특정 방식이 선택되거나, 두 가지 방식이 혼용되기도 하고, 불규칙하게 변형되기에 수사 학습지도 과정에서 학생과 교사 양측의 부담이 가중된다. 이에 본 연구는 이중 수사 체계로 인한 학습 지도 난점 개선의 필요성을 인지하였다. 이를 위하여 수사 체계 방식이 선택되는 맥락과 다양한 변형 사례, 현행 교육과정과 교과서의 관련 지도 내용을 분석·정리하였다. 분석 결과, 수사를 사용하는 실제 상황에 따라 나타나는 수사 체계 방식의 선택 및 변형의 특징이 존재하였으나 그러한 특징의 기준이 모호하고 교육과정 및 교과서 내 구체적인 지도 지침 또한 부재하였다. 이 경우 현장 교사의 역할이 더욱 중시되기 때문에 교사는 이중 수사 체계 관련 실제 상황의 세부 특징을 인지하고 학생에게는 이중 수사 체계 사용의 다양한 측면에 대한 경험과 연습을 통하여 이해하게 만듦으로써 수사 체계 교수·학습 개선을 위한 방향을 논의하였다.