Back projection 알고리즘을 이용한 3차원 형상복원에 관한 연구

신동철 선문대학교 대학원 1997 논문집 Vol.1 No.-

In this research, we developed a 3-D shape reconstruction system which can reconstruct invisible part of the 3-D object by using the computer tomography algorithm. Computer tomography usually can be used in medical imaging system that have applied for non-distructive inspection system. We can obtain the eight directional projected image that X-ray system scanned the 3-D object that is rotated by 45 degrees. Captured image from image intensifier is distorted because the input plate of image intensifier has sphere surface. In this thesis, image distortion can be compensated and each layer of 3-D object can be reconstructed by using back projection algorithm. The 3-D shape is reconstructed to accumulate each layer obtained by back projection.

Plasticizer effects on the polymer electrolytes prepared by polymerizing the mixtures of polymerizable PEO-oligomers, Copolymer of PVDC and PAN

이계중 선문대학교 대학원 1998 논문집 Vol.2 No.-

The polymer electrolytes, lithium ion conductor, prepared by polymerizing the mixtures of polymerizable PEO-oligomer, plasticizer for enhancing ionic conductivity and SARAN. The ionic conductivites of the polymer electrolytes were measured by impedance. The "SARAN", which is a copolymer between poly(vinylidene chloride) and poly(acrylonitrile), purchased from Dow Chemical Co. was used as matrix polymer due to its high solubility in PEO acrylate system. After adding proper initiators and lithium salts, ion-conducting complexes were obtained as thick films by thermal polymerizations, and measurements of physical properties such as impedance were performed varying temperatures and plasticizer contents. As the temperature goes up, the ionic conductivity of the polymer electrolytes increases as expected, since the movement of chain and the mobility of lithium ion are enhanced. Plasticizer were added to this system to improve the ionic conductivity with low weight-percentage, because adding plasticizer made the polymerization difficult.

리튬 고분자 고체전해질 제조 및 이온전도 특성

김창숙 선문대학교 대학원 1998 논문집 Vol.2 No.-

본 논문은 라인홀트 니버가 제시한 기독교 현실주의 이해를 니버의 성서적 인간이해와 사회이해, 그리고 기독교 현실주의로 나누어 살펴보았다. 그리고 아가페적 사랑을 실현하기 위한 방법으로 사회정의를 근사치로 취한 근사적 접근법에 주목하였다. 또한, 라인홀트 니버의 기독교 현실주의를 통해 통일(정치)신학의 공의주의 사상을 살펴보고자, 통일신학의 인간 이해를 살펴보고, 축복가정에 대한 새로운 이해에 대한 필요도 지적하고 있다. 다시 말하면, 공의주의가 실현된 사회를 이루기 위해서는 보다 구체적인 현실적 이해가 절실히 필요하며 참사랑을 중심한 참가정을 이루기 위한 근사적 접근의 필요성을 지적하고자 했다. Polymerizing the mixtures of polymerizabie PEO-oligomers with matrix polymer, SARAN F-350[copolymer of poly(vinylidene chloride) and poly(acrylonitrile)] have been prepared solid polymer electrolytes. Polymerizable PEO methacrylates[poly(ethylene glycol) methyl ether methacrylate and poly(ethylene glyco)ethyl ether methacrylate] and diacrylates[poly(ethylene glycol)diacrylate] were mixed to vary the extent of cross-linking, and poly(vinylidene chloride) copolymer was also added to enhance the mechanical stability. After SARAN F-350 and initiator were added to PEO-acrylates solution with lithium salts(LiCF₃SO₃), electrolyte were obtained as thick films by thermal- and UV-radiation polymerizations and then impedances, TG-DTA and SEM photography were measured varying temperatures and SARAN contents. Adding SARAN causes initial increase in conductivity, but larger the contents of SARAN decreases the conductivity due to it effect on rigidity of polymer films. However, the mechanical stability was greatly enhanced as with the contents of SARAN. As the temperature goes up, the conductivity of the solid electrolytes increases as expected, since the movement of chain and the mobility of lithium ion are enhanced. Plasticizers such as N-mcthylpyrrolidonc(NMP) and propylene carbonate(PC) were added to this system with low weight-percentage therefore, ionic conductivity improved by increasing of flexibility on polymer chain.

PECVD로 성장시킨 유사 비정질 다이아본드박막의 특성 연구

박정홍 선문대학교 대학원 1998 논문집 Vol.2 No.-

Diamond like carbon(DLC) films have attracted much attention recently because of its mechanical, chemical and electrical properties. In spite the structure of DLC is not well defined, both the mechanical hardness and the chemical inertness are similar to those of diamond. Therefore, this structure can be applied to variety areas such as protective coating material, cold cathode field emission display, etc. A series of DLC films were grown by plasma enhanced chemical vapor deposition(PECVD) technique and were investigated by various kinds of characterization methods. The mixture of CH4, He and Ar gas was used as a process gas and the Si wafer was used as a substrate. The characterization was performed through FT-IR, Raman spectroscopy, AFM and SEM. Basically, DLC films contains the hydrogenated amorphous carbon(a-C:H) as well as the C-C bonded structure. The structural property has changed according to the variation of the CH4 flow rate or the chamber during the process. In the condition of low pressure and low CH4 gas flow rate, the formation of sp³ bonding was dominant with respect to the sp^(3) bonding.

분산환경에서 RPC를 이용한 시스템 소프트웨어의 성능 측정 방법에 관한 연구

차영준,임동선,강희국,김광균,박윤용 선문대학교 대학원 1999 대학원학술논문집 Vol.1 No.-

본 논문에서는 이종의 분산 환경에서 동종의 하드웨어 기반아래에서의 UNIX 시스템 소프트웨어의 성능을 비교 · 분석 평가 할 수 있는 벤치마크 프로크램의 구현에 관하여 기술하였다. 이종의 분산 환경에서 시스템 소프트웨어의 성능을 us단위까지 측정 가능한 스톱워치 타이머롤 설계하였다. 그리고, 원격프로시저호출(RPC)를 이용하여 다른 UNIX 시스템 소프트웨어의 성능을 측정하였다 A UV laser annealing was carried out on amorphous SiC films which were deposited on Si substrate by using plasma-enhanced chemical-vapour deposition. Scanning electron microscope micrographs taken from the surfaces of the films exhibited images of grains that were not presented before the UV laser treatment. Fourier-transformed infrared and X-ray diffraction experiments identified those grains as microcrystals of SiC and Si transformed from the amorphous state. Auger electron spectroscopy depth profiling analysis showed that there were more Si atoms than C atoms in the layer. The resistivities of films changed abruptly from 170 Ωcm to 226 kΩcm after the UV laser annealing.

ECR PECVD를 이용한 LCD의 TFT용 a-si : H 박막의 증착시 마이크로파 펄스가 막의 특성에 미치는 영향

박상국 선문대학교 대학원 1997 논문집 Vol.1 No.-

Hydrogenated amorphous silicon(a-Si:H) thin films have been prepared by electron cyclotron resonance plasma-enhanced chemical vapor deposition(ECR PECVD) method. Ar gas and silane gas have been used as a plasma gas and a source gas respectively. 27.51kHz and 301kHz pulses have been applied to the microwave power of the ECR PECVD for the selective-generation of SiH3 radicals which are known as most desirable radicals for the deposition of high quality a-Si:H films. It was found that the total hydrogen content, its bonding configuration and substrate temperature of a-Si:H films have been changed. The optical constants such as refractive index(n). absorption coefficient( a ), the optical energy band gap(E_(g)) of a-Si:H have been increased. Especially the present method has reduced the defect density by one order of magnitude. These results suggest that the present method provide much higher quality a-Si:H films than the conventional ECR PECVD method. The quality of a-Si:H films deposited by this new method is as good as that of a-Si:H films deposited by radio-frequency(RF) PECVD at temperatures higher than 250℃, even though the a-Si:H films were deposited without intentional heating of the substrate. These results show a possibility that plastic substrates can be used for TFT-LCDs.(thin film transistor-liquid crystal displays)

CNC 공작기계의 열변위 보정장치 개발

황선창 선문대학교 대학원 1999 논문집 Vol.3 No.-

A method for the evaluation and the compensation of the vertical milling machine is presented. The method used a mathematical model of thermal deformation based on temperature variations of the machine and the environment. It follows an empirical approach and requires low cost equipment to be applied. According to this study, machine error caused by thermal deformation will be reduced to about 1/4.

열전대용 Membrane 제작을 위한 단결정 실리콘의 이방성 식각 연구

천인호 선문대학교 대학원 1999 논문집 Vol.3 No.-

Three different etching solutions KOH, KOH-IPA and TMAH were used for anisotropic etching for membrane structure formation, single crystal silicon substrate. The etching characteristic was observed for the each solution in this experiment. Also, etching rate depends on the etchant temperature and concentration. The different characteristics were observed according to pattern directions and etchant concentration was measured. The pattern was made to incline 45℃ on the primary flat and the KOH 20w t·%, the etching shape was U-groove above 80℃, and V-groove shape was observed below 80℃. The hillock which was generated at silicon surface was decreased as the etchant temperature and concentration increased. In this experiments, the new membrane structure design and process were introduced for MEMS thermocouple.

PC-NC Interface Board를 위한 Windows 95용 가상 장치 드라이버의 개발

조인호 선문대학교 대학원 1999 논문집 Vol.3 No.-

The real time processing is supported on the PLC, Controlling Servo Driver in order to implement one CPU PC-NC. In the case of implementing PC-NC based on Windows 95, Virtual Device Driver is intended to support real time processing. PC-NC Interface Board connects PC-NC with other devices. Therefore, PC-NC control PC-NC Interface Board to control Servo Driver and PLC. Virtual Device Driver(VxD) is core of Windows 95. VxD can control hardware device directly by reading and wirting any information on and from any I/O address. In the past, Windows 95 has controled I/O without VxD on PC-NC System. This system has problem to control Servo Driver and PLC, because these have strict response time. The control part of PC-NC can go into Windows System area from application program. So Faster time response to interrupt and control can be obtained using VxD on control part of PC-NC. The result of testing VxD is 50μs~500μs time response. This response time is improved five times faster. Windows 95 can be used on one CPU PC-NC system to contruct control part and MMⅠ It is expected that PC-NC system can be connected with other utilities more easily and flexibly and operator can handle and learn more easily. Unit product price will be cheaper than now.

A Study on Empirical Errors of Some Numerical Quadratures

Boulgakov, N.V 선문대학교 대학원 1999 논문집 Vol.3 No.-

In this work we study a typical problem from Information-Base Complexity. The problem is to find the computation errors of some numerical quadratures (namely Simpsons and Trapezoidal) in the numeric integration problem. Our integrands are r-fold Wiener functions from th interval [0,1] and only at finite number of points the function values are evaluated. In order to analyze this problem were chosen average case setting and Wiener measure which have advantages of others. Whil analytical analysis of numerical quadrature errors were chosen the validation criteria. Then we chose the method of empirical investigation, which muc extend the results of analytical analysis. Chosen empirical method o investigation (Monte-Carlo simulation) and its constituent parts we implemented as program on C++. Then we perform first part of empirical investigation where computed results are compared with the validation criteria. On the final part of research we perform computation for th functions which do not have the exact analytical solution. Computed result are discussed and analyzed.