• 한국산업융합학회 논문집
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• 제25권6_2호
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• pp.1097-1102
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• 2022

With the continuous development of the current industry, the current global environment is in a very serious situation, with resource supply and demand dependent on imports and huge costs for waste disposal due to the depletion of resources and mass generation of industrial waste. Its limitations have already been revealed in many fields, and the importance of re-manufacturing is drawing attention as a countermeasure to these problems. Re-manufacturing aims to recover products that are in the aging and disposal stages, recover to performance close to new products, and re-commercialize them. Among them, most of the machine tools are made of materials such as steel and cast iron with large structures, and raw materials are widely used when producing new products. In addition, since a lot of carbon is generated due to production, it is an object that can obtain a great re-manufacturing effect. Planner millers belonging to large machine tools are one of the machine tool equipment that can greatly reduce resources and energy through re-manufacturing because the structure is very large and the casting is several to tens of tons. Through this machine tool, performance tests and results are derived on the development of re-manufacturing source technology and domestic servo motor and CNC control device.

• 한국기계가공학회지
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• 제21권2호
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• pp.54-63
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• 2022

Among the various industrial robots, palletizing robots have received particular attention because of their higher productivity in accordance with technological progress. When designing a palletizing robot, the main components, such as the servo motors and reducers, should be properly selected to ensure its performance. In this study, a practical method for selecting the motors and reducers of a robot was proposed by performing the dynamic analysis of rigid-flexible multibody systems using ANSYS and ADAMS. In the first step, the links and frames were selected based on the structural analysis results obtained from ANSYS. Subsequently, a modal neutral file (MNF) with information on the flexible body was generated from the links and frames using modal analysis through ANSYS and APDL commands. Through a dynamic analysis of the flexible bodies, the specifications of the major components were finally determined by considering the required torque and power. To verify the effectiveness of the proposed method, the analysis results were compared with those of a rigid-body model. The comparison showed that rigid-flexible multibody dynamic analysis is much more useful than rigid body analysis, particularly for movements heavily influenced by gravity.

• 한국전자통신학회논문지
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• 제17권4호
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• pp.729-738
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• 2022

기존의 옷장은 단순한 의류를 보관하는 용도로만 사용되어 왔었다. 단순히 옷들을 보관하는 기능만 있기 때문에 습도나 온도 같은 환경을 조절하려면 따로 제습제 등의 물품을 구매해서 비치하는 방법밖에 없어 불편함이 있었다. 본 논문에서는 기존 옷장에서 편의성을 증대시켜 자동으로 온습도 조절 및 여러 편의 기능에 대한 것을 추가하였으며 기능을 효율적으로 동작 시키기 위하여 실험을 통하여 기능을 동작 시키기 위한 센서의 위치를 정하였고 여러 편의 기능과 실험 데이터를 기반으로 센서를 설치한 옷장 개발과 더불어 최근 다년간 성장한 스마트 홈 시장과 스마트 폰 애플리케이션 시장의 흐름에 맞춰 옷장과 스마트폰의 블루투스 페어링을 통한 옷장 내부의 온습도 조절 기능 및 다른 기능을 스마트폰을 사용하여 사용자에 맞춘 의류선택기능과 애플리케이션 내의 날씨 데이터를 통해 옷장 내부의 옷을 날씨에 맞는 코디 추천 기능 등의 편의 기능을 구현하고자 한다.

• 한국정밀공학회지
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• 제13권9호
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• pp.114-129
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• 1996

This paper describes the whole development phase for the underwater vehicle actuating system with high hydroload torque disturbance. This includes requirement analysis, system modeling, control algorithm design, real time implementation, test and performance evaluations. As for driving control algorithms, fuzzy logic, variable structure and PD(Proportional-Differential) algorithm were designed and implemented on board controller using a single chip microprocessor. Intel 8797. And test and performance evaluation is carried out both single test and wystem integration test. We could confirm the basic performance of actuating system through the single test and gereral developing work of any actuating systems was finished with a single performance test of actuating system without system integration test. But, we suggested that system integration test be needed. System integration test is carried out using G/C HILS(Guidance and Control Hardware-In-the -Loop Simulation) which is constituted flight motion simulator, load simulator, real time host computer and the related subsystems such as inertial navigation system, power supply system and Guidance and Control Computer etc.. The most important practical contribution of this paper is that full system characteristics such as minimal control effort, enhancement of guidance and autopilot performance by the actuating system using G/C HILS technique are investigated. Through full running G/C HILS, in spite of the passing to single tests, some control algorithm resulted in failure as to stability of full system and system time frame.

• Geomechanics and Engineering
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• 제29권5호
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• pp.567-582
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• 2022

In the present study, a series of physical experiments and numerical simulations were conducted to investigate the effects of mode I and mixed-mode I/II cracks on the fracture modes and stability of roadway tunnel models. The experiments and simulations incorporated different inclination angle flaws under both static and dynamic loads. The quasi-static and dynamic testing were conducted by using an electro-hydraulic servo control device and drop weight impact system (DWIS), and the failure process was simulated by using rock failure process analysis (RFPA) and AUTODYN software. The stress intensity factor was also calculated to evaluate the stability of the flawed roadway tunnel models by using ABAQUS software. According to comparisons between the test and numerical results, it is observed that for flawed roadways with a single radical crack and inclination angle of 45°, the static and dynamic stability are the lowest relative to other angles of fractured rock masses. For mixed-mode I/II cracks in flawed roadway tunnel models under dynamic loading, a wing crack is produced and the pre-existing cracks increase the stress concentration factor in the right part of the specimen, but this factor will not be larger than the maximum principal stress region in the roadway tunnel models. Additionally, damage to the sidewalls will be involved in the flawed roadway tunnel models under static loads.

• 한국전자통신학회논문지
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• 제18권6호
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• pp.1379-1386
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• 2023

본 논문에서는 시각장애인을 위한 스마트 지팡이의 설계와 개발에 대해 다루고 있다. 스마트 지팡이는 초음파 거리 센서, 피에조부조, 조도 센서, LED선, 블루투스 모듈, 카메라 모듈, 스위치, 배터리 등의 센서와 모듈을 내장하고 있으며, 사용자가 지팡이를 사용하는 동안 주변 환경을 카메라로 실시간 스트리밍할 수 있고 보호자에게 공유할 수 있다. 스마트 지팡이는 초음파 거리 센서를 사용하여 앞에 있는 장애물의 거리를 측정하여 사용자에게 경고음을 울려줍니다. 블루투스 모듈과 스마트폰 앱을 이용하여 보호자에게 자신의 위치를 알려준다. 이러한 스마트 지팡이는 시각장애인이 일상생활에서 자신의 이동을 보다 안전하게 할 수 있도록 돕는데 큰 도움이 될 수 있다.

• 한국의류학회지
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• 제48권2호
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• pp.312-327
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• 2024

In this study, a rehabilitation 3D printed wearable device was developed by combining an assembly-type robot hand and an integral-type robot hand through fused deposition 3D printing manufacturing with various hardness TPU (Thermoplastic Polyurethane) filaments. The hardware configuration of the robot hand includes a controller designed with four motors, one small servo motor, and a circuit board. In the case of the assembly-type robot hand model, a 3D printed robot hand was assembled using samples printed with TPU of hardness 87A and 95A. It was observed that TPU with a hardness of 95A was suitable for use due to shape stability. For the integrated-type robot hand model, the external sample using TPU of hardness 95A could be modified through a cutting method, and the hardware configuration is the same as the assembly-type. The system structure of the 3D printed robot hand was improved from an individual control method to a simultaneous transmission method.Furthermore, the system architecture of an integrated 3D printed robotic hand rehabilitation device and the application of the rehabilitation device were developed.

• Smart Structures and Systems
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• 제33권1호
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• pp.1-16
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• 2024

The investigation on vehicle-bridge coupling system (VBCS) is crucial in bridge design, bridge condition evaluation, and vehicle overload control. A real-time hybrid testing (RTHT) method for VBCS (RTHT-VBCS) is proposed in this paper for accurately and economically disclosing the dynamic performance of VBCSs. In the proposed method, one of the carriages is chosen as the experimental substructure loaded by servo-hydraulic actuator loading system in the laboratory, and the remaining carriages as well as the bridge structure are chosen as the numerical substructure numerically simulated in one computer. The numerical substructure and the experimental substructure are synchronized at their coupling points in terms of force equilibrium and deformation compatibility. Compared to the traditional iteration experimental method and the numerical simulation method, the proposed RTHT-VBCS method could not only obtain the dynamic response of VBCS, but also economically analyze various working conditions. Firstly, the theory of RTHT-VBCS is proposed. Secondly, numerical models of VBCS for RTHT method are presented. Finally, the feasibility and accuracy of the RTHT-VBCS are preliminarily validated by real-time hybrid simulations (RTHSs). It is shown that, the proposed RTHT-VBCS is feasible and shows great advantages over the traditional methods, and the proposed models can effectively represent the VBCS for RTHT method in terms of the force equilibrium and deformation compatibility at the coupling point. It is shown that the results of the single-degree-of-freedom model and the train vehicle model are match well with the referenced results. The RTHS results preliminarily prove the effectiveness and accuracy of the proposed RTHT-VBCS.

• Tuberculosis and Respiratory Diseases
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• 제45권1호
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• pp.169-175
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• 1998

연구배경: Heliox는 기도 저항이 증가된 환자에서 분시환기량의 증가와 호흡일의 감소로 인해 $PaCO_2$가 감소함이 알려져 있다. 이러한 효과 이외에도 최고 호기 유량비의 증가와 가스 분포의 호전에 의한 사강 호흡률의 감소효과도 있을 것으로 기대된다. 이에 저자등은 공기($N_2-O_2$)호흡 시와 통일한 분시환기량과 호흡일의 조건에서 heliox투여로 $PaCO_2$가 감소하는지 연구하였다. 대상 및 방법: 호흡 부전으로 기계호흡 중인 환자 중 기관지 천식이나 상기도 협착이 있으며 근 이완제 투여로 자신의 호흡일이 없는 8명(남 : 여 =5 : 3, 평균 68세)을 대상으로 하였다. 연구는 각 15분씩 기저 $N_2-O_2$투여, heliox투여 및 washout순으로 진행하였다. Heliox는 Servo 900C기종의 저압입구(low pressure inlet)를 통해 공급하였다. 호흡 역학 지표는 CP-100 monitor(Bicore, USA)로 측정하였고 heliox 투여시 동일한 일호흡량 유지을 위해 $N_2-O_2$에 대한 상대유량 비로 상시 호흡량을 보정하였다. 사강 호흡률용 Bohr의 공식으로 구하였다. 결 과: 일호흡량, 분시환기량, 최고 흡기압 및 최고 흡기 유량 비는 $N_2-O_2$와 heliox투여 군 사이에 차이가 없었다. 최고 호기 유량 비는 heliox투여 군에서 ($0.52{\pm}0.19$L/sec) $N_2-O_2$투여 군($0.44{\pm}0.13$L/sec)보다 높았다 (p=0.024). $PaCO_2$는 heliox투여 군 ($56.1{\pm}14.1$mmHg)이 $N_2-O_2$투여 군 ($60.5{\pm}15.9$mmHg) 보다 낮았고 (p=0.027), 사강 호흡률은 heliox투여군 ($71{\pm}10%$)이 $N_2-O_2$ 투여 군 ($73{\pm}9%$)보다 낮았다. 결 론: 분시환기량과 호흡일이 동일한 조건에서도 heliox투여 시 $N_2-O_2$투여에 비해 $PaCO_2$의 감소가 관찰되며 이는 사강 호흡률의 감소와 관련이 있을 것으로 사료된다.

• Tuberculosis and Respiratory Diseases
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• 제48권5호
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• pp.766-772
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• 2000

배경 : 압력조절환기법(pressure control ventilation mode, PCV)에서 설정된 기도압의 달성은 기도저항이 일정한 조건에서 초기 흡기 유량 (inspiratory flow)에 의해 결정되며 압력상승시간(pressure rise time) 조절은 이 흡기 유량을 변동시킨다. 압력조절환기법에서 흡기 일환기량은 흡기 시간과 흡기 시간내 평균 흡기 유량에 따라 결정되므로 압력 도달 시간을 짧게 하면 초기 유량이 많아지게 되고 따라서 흡기되는 용적이 증가할 것으로 예상된다. 본 연구는 압력조절환기 법에서 압력상승시간을 줄이는 것이 흡기 일환기량 및 가스교환을 호전시키는지 알아보고자 하였다. 방법 : 호흡부전으로 기계호흡 중인 환자 13명(58$\pm$16세, 남 : 여=7 : 6)에서 Servo 300 (Simens-Elema, Solna, Sweden) 상의 압력상승시간 10%. 5% 및 30분 간 씩 적용하고 동맥혈 검사, 혈역동학적 지표(혈압, 분당맥박수) 및 호흡 지표(일회 호흡량, 최대 흡기유량, 최대 흡기압, 평균 기도압, 기도저항, 탄성도, 호기말 이산화탄소, 동맥혈가스)를 측정하였다. 결과 : 1) 압력상승시간이 10%, 5%, 0%로 변경시 일회 호흡량은 425$\pm$94 ml, 439$\pm$101 ml, 456$\pm$106ml로 증가되었다(p<0.001). 압력상승시간 단축에 따라 평균기도압 역시 증가되었다(각각 11.2$\pm$3.7cm $H_2O$, 12.0$\pm$3.7 cm $H_2O$, 12.5$\pm$3.8 cm $H_2O$; p<0.001). 2) pH는 10% 와 5% 보다 0%에서 높았으며(각각 7.40$\pm$0.08, 7.40$\pm$0.92, 7.41$\pm$0.96 ; p<0.0), $PaCO_2$도 10%와 5%에서 보다 0%에서 낮았다(각각 47.4$\pm$15.8 mm Hg, 47.2$\pm$15.7 mm Hg, 44.6$\pm$16.2 mm Hg ; p<0.01). 결론 : 압력조절환기법에서 압력상승시간의 단축은 일환기량과 평균기도압을 증가시키고, 동맥혈이산화탄소분압 저하 및 이에 따른 pH 상승 효과가 있었다. 압력조절 환기법에서 압력상승시간은 일환기량을 조절할 수 있는 한 변수로 사료된다.