• 대한토목학회논문집
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• 제32권5A호
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• pp.267-275
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• 2012

본 연구에서는 철근 콘크리트 벽과 강판 콘크리트 벽이 이질접합 형태로 만나는 구조물의 휨 및 전단거동 특성을 검토하기 위하여 L형과 I형 타입의 실험체를 제작하고 구조실험을 수행하였다. 실험 시, 지진하중 등에 대한 실험체의 동적특성을 확인하기 위하여 Push 및 Pull을 반복하는 싸이클 하중을 구현하고자 하였다. L형 실험체에 대한 면외 휨 실험결과, 실험체의 공칭강도를 초과하는 휨 성능을 발휘하였으며, 이에 따라 설계에 적용된 수직철근의 미겹침 이음길이의 타당성을 확인할 수 있었다. 한편, 강판 콘크리트 벽 내에 수평철근의 배근 유무를 변수로 구성한 두 개의 I형 실험체에 대한 면내 전단 실험결과, 수평철근의 배근 유무에 상관없이 공칭강도를 초과하는 전단 성능을 보였다.

• International Journal of Control, Automation, and Systems
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• 제5권4호
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• pp.419-428
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• 2007

This paper describes the development of a six-axis force/moment sensor with rectangular taper beams for an intelligent robot's wrist and ankle. In order to accurately push and pull an object with an intelligent robot's hand, and in order to safely walk with an intelligent robot's foot, the robot's wrist and ankle should measure three forces Fx, Fy, and Fz, and three moments Mx, My, and Mz simultaneously from the mounted six-axis force/moment sensor to the intelligent robot's wrist and ankle. Unfortunately, the developed six-axis force/moment sensor utilized in other industrial fields is not proper for an intelligent robot's wrist and ankle in the size and the rated output of the six-axis force/moment sensor. In this paper, the structure of a six-axis force/moment sensor with rectangular taper beams was newly modeled for an intelligent robot's wrist and ankle, and the sensing elements were designed by using the derived equations, following which the six-axis force/moment sensor was fabricated by attaching strain-gages on the sensing elements. Moreover, the characteristic test of the developed sensor was carried out by using the six-component force/moment sensor testing machine. The rated outputs from the derived equations agree well with those from the experiments. The interference error of the sensor is less than 2.87%.

• Journal of Electrical Engineering and Technology
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• 제12권4호
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• pp.1484-1494
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• 2017

We present a two-stage inverter with high step-up conversion ratio engaging modified finite-set Model Predictive Control (MPC) for utility-integrated photovoltaic (PV) applications. The anticipated arrangement is fit for low power PV uses, the calculated efficiency at 150 W input power and 19 times boosting ratio was around 94%. The suggested high-gain dc-dc converter based on Cockcroft-Walton multiplier constitutes the first-stage of the offered structure, due to its high step-up ability. It can boost the input voltage up to 20 times. The 3S current-source inverter constitutes the second-stage. The 3S current-source inverter hires three semiconductor switches, in which one is functioning at high-frequency and the others are operating at fundamental-frequency. The high-switching pulses are varied in the procedure of unidirectional sine-wave to engender a current coordinated with the utility-voltage. The unidirectional current is shaped into alternating current by the synchronized push-pull configuration. The MPC process are intended to control the scheme and achieve the subsequent tasks, take out the Maximum Power (MP) from the PV, step-up the PV voltage, and introduces low current with low Total Harmonic Distortion (THD) and with unity power factor with the grid voltage.

• 대한전자공학회:학술대회논문집
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• 대한전자공학회 2002년도 하계종합학술대회 논문집(2)
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• pp.165-168
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• 2002

As the demand for higher data-rate chip-to-chip communication such as memory-to-controller, processor-to-processor increases, low cost high-speed serial links\ulcorner become more attractive. This paper describes a 0.25-fm CMOS 1.6Gbps/pin 4-level transceiver using Stub Series Terminated Logic for high Bandwidth. For multi-gigabit/second application, the data rate is limited by Inter-Symbol Interference (ISI) caused by channel low pass effects, process-limited on-chip clock frequency, and serial link distance. The proposed transceiver uses multi-level signaling (4-level Pulse Amplitude Modulation) using push-pull type, double data rate and flash sampling. To reduce Process-Voltage-Temperature Variation and ISI including data dependency skew, the proposed high-speed calibration circuits with voltage swing controller, data linearity controller and slew rate controller maintains desirable output waveform and makes less sensitive output. In order to detect successfully the transmitted 1.6Gbps/pin 4-level data, the receiver is designed as simultaneous type with a kick - back noise-isolated reference voltage line structure and a 3-stage Gate-Isolated sense amplifier. The transceiver, which was fabricated using a 0.25 fm CMOS process, performs data rate of 1.6 ~ 2.0 Gbps/pin with a 400MHB internal clock, Stub Series Terminated Logic ever in 2.25 ~ 2.75V supply voltage. and occupied 500 * 6001m of area.

• 전기학회논문지P
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• 제65권2호
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• pp.101-107
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• 2016

The main target in this paper is the localization of VME Type EPSM in Generator Exciter(EX2100) System. Developed EPSM has the compatibility with the existing product in the structure and shape and electrical feature and so on, but it has a much improved capacity and reliability in comparison with origin company product. this paper, to improve these functions, put emphasis on protection, monitoring, power capacity increase(over 120%), an enlarged scale of input voltage supply, AC/DC dual voltage use and so on. After manufacturing product localization, it was carried out several tests for the performance and reliability verification of developed product. These tests were performed in Authorized Inspection Agency(KTL) and field application test and maker self-test were additionally performed. Finally, the results of all tests were "success".

• 한국전자파학회논문지
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• 제15권6호
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• pp.540-547
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• 2004

본 논문에서는 900 MHz대역에서 70 % 이상의 고효율을 갖는 전류 모드 D급 전력증폭기를 설계, 제작하였다. 푸시-풀 B급 전력증폭기의 구조를 기초로 하여 병렬 고조파 컨트롤 회로를 적용하여, 기존 D급 전력증폭기의 큰 손실 요인이었던 소자 내 커패시턴스의 충, 방전에 의한 전력 손실을 최소화하였다. 측정결과, 900 MHz 대역, 출력전력 3.2 W에서 73 % 전력 부가 효율, 그리고 출력전력 5 W에서 72 % 전력 부가 효율을 각각 얻었으며 DC 전력에 따라 출력의 크기가 선형적으로 변화하는 D급 전력증폭기의 특성을 확인하였다.

• 대한안전경영과학회지
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• 제24권2호
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• pp.127-134
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• 2022

Production management in the automobile parts industry is carried out according to the production plan of the customer, so it is important to prevent shortages in product supply. As the product composition became increasingly complex, the MES System was built for the purpose of efficient production plan management and inventory management, but its utilization is low. This study analyzed the problems of the MES system and sought to improve it. Through previous studies, it was confirmed that the inventory management of the pull approach that actually occurred in the warehouse is more suitable than the push approach based on the forecast of the warehouse for the volatility, complexity, and uncertainty of orders in the auto parts industry. To realize this, we tried distributed MRP by using the ADO function of VBA to link the standard information of the MES system with Excel and change the structure of the BOM table. Through this, it can help increase the accuracy of production planning and realize efficient inventory management, thereby increasing the utilization of the MES system in the auto parts industry and enhancing the competitiveness of the company.

• 한국염색가공학회:학술대회논문집
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• 한국염색가공학회 2011년도 제44차 학술발표회
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• pp.36-36
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• 2011

We synthesized new dye sensor based on indole compound. Through the UV-vis absorptions, we analyzed chemosensing properties to explain metal binding properties. The peak absorptions increased at 472 nm when added metal cations($Cd^{2+}$, $Cu^{2+}$, $Hg^{2+}$, $Fe^{2+}$, $Zn^{2+}$, $Ni^{2+}$ and $Cr^{3+}$) and gradually decreased the peak at 516 nm. Thus, this UV-Vis absorption behavior clearly showed the metal binding reaction. To measure energy level of used dye sensor, HOMO/LUMO energy value was calculated with cyclovaltagramm(CV) and using computational calculation method, in which we estimated the optimum structure of dye sensor. CV and computational calculation method, both compared to find suitable geometric structure. (with almost same energy values.) From the computational calculation, dye sensor has plane structure. So, Amine and ketone in the dye sensor faced each other and makes position to bind metal cations. In addition, these positions was supported pull-push electron system and generated MLCT process, when the dye sensor was bonded with the metal cations and resulted chemosensing properties. Through the electrochemical and computational calculation method analyze, we proposed the chemosensing principles that the dye sensor bind the metal cation between ketone and amine. Finally, the formation type of metal ion bindings was determined by Job's plot measurements.

• Tribology and Lubricants
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• 제40권1호
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• pp.17-23
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• 2024

This study analyzes the thermal effects on the performance of an air foil thrust bearing (AFTB) using COMSOL Multiphysics to approximate actual bearing behavior under real conditions. An AFTB is a sliding-thrust bearing that uses air as a lubricant to support the axial load. The AFTB consists of top and bump foils and supports the rotating disk through the hydrodynamic pressure generated by the wedge effect from the inclined surface of the top foil and the elastic deformation of the bump foils, similar to a spring. The use of air as a lubricant has some advantages such as low friction loss and less heat generation, enabling air bearings to be widely used in high-speed rotating systems. However, even in AFTB, the effects of energy loss due to viscosity at high speeds, interface frictional heat, and thermal deformation of the foil caused by temperature increase cannot be ignored. Foil deformation derived from the thermal effect influences the minimum decay in film thickness and enhances the film pressure. For these reasons, performance analyses of isothermal AFTBs have shown few discrepancies with real bearing behavior. To account for this phenomenon, a thermal-fluid-structure analysis is conducted to describe the combined mechanics. Results show that the load capacity under the thermal effect is slightly higher than that obtained from isothermal analysis. In addition, the push and pull effects on the top foil and bump foil-free edges can be simulated. The differences between the isothermal and thermal behaviors are discussed.

• 문화기술의 융합
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• 제9권6호
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• pp.339-345
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• 2023

기술의 배후에는 디자인이 존재한다. 디자인은 일상 생활의 필요성과 시장 구조와 얽혀 기술을 다루면서도 그 의미에 대해서는 둔감해질 수 있다. 다른 소셜 미디어 플랫폼들과 달리 인스타그램은 이미지 기반의 콘텐츠로 이루어진다. 이에 본 연구의 목적은 중독성 있는 인스타그램 디자인 기능의 검토하고 나아가 디자이너가 지녀야 할 윤리적 책임에 대해 논의한다. 선행 연구된 국내외 주요 문헌의 고찰을 통해 먼저 인스타그램 디자인을 이해하기 위한 이론적 틀을 수립한다. 인스타그램의 역사 및 구조와 기능을 파악하고 이와 관련지어 소셜 미디어 중독을 조장하는 인스타그램 디자인 특성을 확인한다. 이러한 과정을 통해 본 연구는 디자인을 '더 나은 삶을 위한 문제해결의 방법론'으로 정의할 때, 디자인에 있어서 오늘날 디자이너의 역할은 어떠한 문제를 중심으로 어떠한 해결방법을 제시해야 하는지에 대한 성찰을 시도한다. 본 연구에서는 디자인적 쟁점을 통해 인스타그램이 사용자의 중독을 조장하는 메커니즘을 소개하였다. (1) 당겨서 새로고침(Pull-to-Refresh) (2) 푸시 알람에서의 빨간색 색채 (3) 인스타그램 스토리의 프로필 사진 테두리 표현이 그것이다. 이러한 디자인은 사용자의 사회적 욕구와 포모(FOMO, fear of missing out)심리를 자극해, 강박적인 인스타그램 사용 습관의 구조를 형성한다. 인스타그램은 기술의 발전과 함께 디자인과 디자이너의 윤리적 역할을 재고하게끔 하는 사례다. 디지털이 미치는 영향력이 강력한 오늘날의 세계에서 디자이너는 디자인의 목적, 즉 우리 사회와 삶 자체를 포함하여 만드는 것의 본질적인 가치에 대한 재정립이 촉구된다.