• 폴리머
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• 제27권1호
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• pp.17-25
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• 2003

원자 이동 라디칼 중합 (ATRP)을 이용하여 CuBr/N,N,N',N",N"-pentamethyldiethylene triamine 촉매 시스템하에서 용액중합으로 polystyrene 거대 개시제와 polystyrene-b-t-poly(butyl acrylate) (PS-b-P(tBA)) 블록 공중합체를 합성한 후, 가수분해를 통해 polystrene-b-poly(acrylic acid) 양친매성 블록 공중합체를 얻었다. 또한, 이를 중화하여 블록 이오노머를 제조하였다. 합청된 PS-b-P(tBA) 블록 공중합체는 분자량이 5000-10000 정도로 조절되었고, 분자량 분포도 1.2 이하로 비교적 좁게 나타났다. 공중합체는 $^1$H-NMR, FT-IR로 분석하였으며, DSC로 열적 성질을 측정한 결과, styrene의 비율이 더 많기 때문에 100 $^{\circ}C$ 근처에서 T$_{g}$가 나타났으며, TEM을 통해 이온 그룹의 상분리를 확인하였다.분리를 확인하였다.

• Journal of the Korean Wood Science and Technology
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• 제47권1호
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• pp.51-65
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• 2019

A wood-plastic composite (WPC) paver block was manufactured using wood chips waste through an extrusion process, and it was intended to be used for paving in basic rest areas. The first stage in this study covered preliminary tests in terms of flexural strength and dimensional swelling to determine the optimal WPC compounding mix condition, by variation of the WPC ingredients. Next, three different paver blocks including the WPC block, a non-porous cement block, and a porous cement block were tested in terms of various material properties in the laboratory. Finally, two outdoor test sections of the proposed paver blocks were prepared to simulate a basic rest area. Test results indicated that the flexural strength of the WPC paver blocks was about 1.6 times greater than that of the tested cement paver blocks. The WPC block pavement was unaffected by water buoyance as well as volume expansion due to swelling. Results from the impact absorbance test and light falling weight deflectometer (LFWD) test clearly showed that the WPC block paving system marginally satisfied the comfortable and safe hardness range from the pedestrians' perspective, while the results demonstrated that it is structurally sound for application as a road paving block.

• 한국안전학회지
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• 제14권4호
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• pp.3-12
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• 1999

This research concentrates on the influence of non-linearities associated with impact for the nonlinear rocking behavior of rigid block subjected to one dimensional sinusoidal excitation of horizontal direction. The transition of two governing rocking equations, the abrupt reduction in the kinetic energy associated with impact, and sliding motion of block. In this study, two type of rocking vibration system are considered. One is the undamped rocking vibration system, disregarding energy dissipation at impact and the other is the damped rocking system, including energy dissipation and sliding motion. The response analysis using non-dimensional rocking equation is carried out for the change of excitation parameters and friction coefficient. The chaos responses were discovered in the wide response region, particularly, for the case of high excitation amplitude and their chaos characteristics were examined by the time history, Poincare map, power spectra and Lyapunov Exponent of rocking responses. The complex behavior of chaos response, in the phase space, were illustrated by Poincare map. The bifurcation diagram and Poincare map were shown to be effective in order to understand chaos of rocking system.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2003년도 춘계학술대회 논문집
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• pp.1751-1754
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• 2003

Due to advances in information technology, even Engineering Simulations can now be performed in web-based JAVA through an integrated operating system called Virtual Machine and the use of byte code, which guarantees the compatibility of identical codes in every computing system and makes it suitable for web-based simulation system development. This paper introduces an implementation embodied in JAVA Applet that allows a block-diagram type GUI that runs in a web browser for use in the dynamics simulation modeling of powertrains of vehicles and multi-body systems. This system is not restrained by any of the H/W and S/W in the user's computer, so that it has the advantage of providing a GUI that allows web-based block-diagram type modeling.

• 로봇학회논문지
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• 제6권2호
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• pp.141-146
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• 2011

In the TV manufacturing industry, a demand for chic design of TVs is increasing. As a reult of this trend in TV design, more curved surfaces in a TV cabinet are introduced, which enforces the use of fixers to combine a front cabinet with a TV main body. In this paper, we introduce a robot system for attaching various types of fixers to a TV cabinet. The developed system consists of three main blocks. The first one is the dispensing block, in which transferred cabinet is centered and UV adhesives are dispensed on the cabinet. The second one is the fixer attaching block, in which a cabinet is centered again and fixers are attached to pre-determined places on a cabinet by a robot with several end effectors. The last one is the UV hardening block, in which very strong ultraviolet rays are applied to the cabinet for attaching fixers tightly to the cabinet. The developed system is successfully adopted in a TV manufacturing process.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2006년도 춘계학술대회 논문집
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• pp.47-48
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• 2006

A roughness measuring system which comprises an integrating sphere and a stabilized laser has been fabricated with the aim of measuring the roughness correction value which is necessary in gauge block measurement by optical interferometry. To calibrate the system, a Newton's ring interferometer has been introduced. The method how to calibrate the roughness measurement system has been described.

• 한국건축시공학회:학술대회논문집
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• 한국건축시공학회 2007년도 추계 학술논문 발표대회
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• pp.119-123
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• 2007

Recently, the green roofs market is active, but most constructors use former waterproofing method. So there are a lot of problems in the sub-organization of the green roofs system. I studied to use the block panel for the sub-organization of the green roofs system and I tested about the effectiveness of waterproofing, root barrier, drainage, and insulation. I have not found any problems about waterproofing, root barrier, drainage, and insulation in the results. The sub-organization of the green roofs system using the block panel is effective for waterproofing, root barrier, drainage, and insulation. We can apply it to the dried and unified execution technology.

• 한국철도학회:학술대회논문집
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• 한국철도학회 2003년도 추계학술대회 논문집(III)
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• pp.170-175
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• 2003

In order to scheme the optimal assumption that satisfies the travel demand, it should be review the elements that affect on determining the headway, which are signal systems, line shape, vehicle(Light Rail Transit) performance, and so on. When applying the conventional signal systems, including Fixed Block System and Moving Block System, It was confirmed whether or not satisfy the requirements of target line with the way of a numerical formula reviewing and Train performance Simulation on the main line, station, depot, and so forth. Therefore, it should be used as references that decide target line and each sub-system after identifying the compliances for Minimum Headway to Moving Block System.

• 전력전자학회:학술대회논문집
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• 전력전자학회 2007년도 하계학술대회 논문집
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• pp.400-402
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• 2007

This paper presents a vector control implementation for PMSM using Real Time Workshop and Embedded Target for TI C2000 DSP in MATLAB/SIMULINK. Speed, current and vector controllers are easily designed and implemented by using the MATLAB/SIMULINK program. Feedback of motor speed is processed through C28x QEP(Quadrature Encoder Pulse) block from encoder pulse. 3-Phase currents ares processed through C28x ADC block from current sensors. And gating signal of PWM inverter is generated through SVPWM and PWM block. Real-time program is drawn using SIMULINK and then converted program code for speed control of PMSM is downloaded into the TI eZdsp 2812 board. Experiments were carried out to examine validity of the proposed vector control implementation.

• 한국철도학회:학술대회논문집
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• 한국철도학회 2011년도 정기총회 및 추계학술대회 논문집
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• pp.2745-2754
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• 2011

In this paper, we propose a Peak to Average power Ratio(PAR) reduction algorithm by using the Adaptive Block Coding(ABC). The problem of a PAR due to each sub-carrier overlap phenomenon in the OFDM (Orthogonal Frequency Division Multiplexing) system causes the an increasing in the complexity of the A/D converter in the transmitter and a reduction in the efficiency of the amplifier. The proposed ABC algorithm selects the block coding which provides the lowest PAR value based on the various check bit position. It is shown that a PAR of the ABC algorithm can be reduced from 8.35dB to 6.02dB in 16 sub-carriers compared to theconventional block coding scheme. We also extended the ABC algorithm to a larger number of sub-carriers and estimated their PAR values.