• Bulletin of the Korean Chemical Society
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• 제30권8호
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• pp.1755-1759
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• 2009

Surface structure and molecular orientation of self-assembled monolayers (SAMs) formed by the spontaneous adsorption of tetrahydrothiophene (THT) and thiophene (TP) on Au(111) were investigated by means of scanning tunneling microscopy (STM) and carbon K-edge near edge X-ray absorption fine structure (NEXAFS) spectroscopy. STM imaging revealed that THT SAMs have a commensurate (3 ${\times}\;2\sqrt[]{3}$) structure containing structural defects in ordered domains, whereas TP SAMs are composed of randomly adsorbed domains and paired molecular row domains that can be described as an incommensurate packing structure. The NEXAFS spectroscopy study showed that the average tilt angle of the aliphatic THT ring and $\pi$-conjugated TP ring in the SAMs were calculated to be about $30^o\;and\;40^o$, respectively, from the surface normal. It was also observed that the $\pi$* transition peak in the NEXAFS spectrum of the TP SAMs is very weak, suggesting that a strong interaction between $\pi$-electrons and the Au surface arises during the self-assembly of TP molecules. In this study, we have clearly demonstrated that the surface structure and adsorption orientation of organic SAMs on Au(111) are strongly influenced by whether the cyclic ring is saturated or unsaturated.

• Bulletin of the Korean Chemical Society
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• 제32권4호
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• pp.1253-1257
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• 2011

The surface structures, adsorption conditions, and thermal desorption behaviors of cyclopentanethiol (CPT) self-assembled monolayers (SAMs) on Au(111) were investigated by scanning tunneling microscopy (STM), X-ray photoelectron spectroscopy (XPS), and thermal desorption spectroscopy (TDS). STM imaging revealed that although the adsorption of CPT on Au(111) at room temperature generates disordered SAMs, CPT molecules at $50^{\circ}C$ formed well-ordered SAMs with a $(2{\surd}3{\times}{\surd}5)R41^{\circ}$ packing structure. XPS measurements showed that CPT SAMs at room temperature were formed via chemical reactions between the sulfur atoms and gold surfaces. TDS measurements showed two dominant TD peaks for the decomposed fragments ($C_5H_9^+$, m/e = 69) generated via C-S bond cleavage and the parent molecular species ($C_5H_9SH^+$, m/e = 102) derived from a recombination of the chemisorbed thiolates and hydrogen atoms near 440 K. Interestingly, dimerization of sulfur atoms in n-alkanethiol SAMs usually occurs during thermal desorption and the same reaction did not happen for CPT SAMs, which may be due to the steric hindrance of cyclic rings of the CPT molecules. In this study, we demonstrated that the alicyclic ring of organic thiols strongly affected the surface structure and thermal desorption behavior of SAMs, thus providing a good method for controlling chemical and physical properties of organic thiol SAMs.

• 한국정보전자통신기술학회논문지
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• 제11권6호
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• pp.664-670
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• 2018

현대 사회는 감시의 눈이라 하는 CCTV가 일상생활 속에서 다양한 방법으로 영상데이터를 수집하기 위해 사용되고 있다. 치안 및 감시, 방범용으로 CCTV를 활용할 뿐만 아니라 자동차에 블랙박스 등 많은 분야에서 활용되고 있다. 본 논문에서는 STM32F407 ARM 칩을 기반으로 다양한 분야에 응용할 수 있는 카메라 시스템을 개발하기 위해 연구를 진행하였다. 카메라 시스템 개발을 위해 솔리드 웍스 환경에서 전체적인 구조를 3D를 기반으로 카메라 시스템을 모델링을 진행하였다. PCB 보드 설계는 카메라 시스템 모델링 파일에서 PCB 부품을 iges 파일로 추출하여 Altium Designer 툴에서 3D와 2D 보드로 변환하여 PCB 설계 진행함으로써 완성도 높은 조립성을 가질 수 있도록 진행하였다. 카메라 시스템 회로 및 PCB를 설계한 후, TRM(Thermal Risk Management) 툴을 활용해서 보드에서 발생하는 발열 시뮬레이션을 진행을 통해 대처할 수 있도록 함으로써 안정적인 시스템 구현에 관한 연구를 진행하였다.

• 한국정밀공학회지
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• 제15권3호
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• pp.99-106
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• 1998

Recently, scientists introduced a new type of microscope capable of investigating nonconducting surfaces in an atomic scale, which is called AFM (Atomic Force Microscope). It was an innovative attempt to overcome the limitation of STM (Scanning Tunnelling Microscope) which has been able to obtain the image of conducting surfaces. Surfaces of samples are imaged with atomic resolution. The AFM is an imaging tool or a profiler with unprecedented 3-D resolution for various surface types. The AFM technology, however, leaves a lot of room for improvement due to its delicate and fragile probing mechanism. One of the room for improvements is gap control between probe tip and sample surface. Distance between probe tip and sample surface must be kept in below one Angtrom in order to measure the sample surface in Angstrom resolution. In this paper, AFM system modeling, experimental system identification and control scheme based on system identification are performed and finally sample surface is measured by home-built AFM with such a control scheme.

• 한국도서관정보학회지
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• 제53권2호
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• pp.333-353
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• 2022

본 연구는 '물리학' 수업에서 교과독서 활동으로 작성된 독후감상문의 교육과정 연계성을 분석하는데 목적이 있다. 연구를 수행하기 위해 교과독서 활동으로 작성한 332편의 물리학 독서감상문을 수집하여 키워드와 키워드들의 연결 관계를 분석하고, STM(Structural Topic Modeling)을 적용하여 토픽을 추출하였다. 분석 결과, 물리학 독서감상문의 주요 키워드는 '생각', '내용', '설명', '이론', '사람', '이해' 등으로 나타났으며, 도출된 키워드의 영향력과 연결 관계를 살펴보기 위해 연결중심성, 매개중심성, 위세중심성을 제시하였다. 토픽모델링 분석 결과, 물리학 교육과정과 관련된 11개 토픽이 추출되었으며, 3과목(물리학I, 물리학II, 과학사), 6개 영역(힘과 운동, 현대물리, 파동, 열과 에너지, 서양과학사, 과학이란 무엇인가)에서 교육과정 연계성을 확인할 수 있었다. 본 연구의 결과는 추후 교과 특성을 반영한 교과독서를 보다 체계적으로 시행할 수 있는 근거자료로 활용할 수 있을 것이다.

• Maxillofacial Plastic and Reconstructive Surgery
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• 제28권1호
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• pp.21-26
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• 2006

Considering the skeletal class III malocclusion that complains of mandibular prognathism, there have been some studies of the mandibular change for comparing the changes of pre operative with post operative state. Nowadays it is common to do the orthognathic 2-jaw surgery for the correction of the maxillary deficiency, the post operative stability and the esthetics. We compare and analyze the changes of soft tissue around the nose and the lip with the changes in the direction and the amount of maxilla. Patients who were diagnosed as maxillofacial deformity and received orthognathic surgery of both jaws at Yongdong Severance hospital from 2001 through 2003 were included in this study. Their lateral cephalograms were analyzed, and the post operative change of hard tissue and soft tissue were studied. Upon analyzing the preoperative cephalograms and 6 month post operative cephalograms, there were significant in the vertical change of Labialis superius(Ls) and Stomion(Stm) in soft tissue in relation to the vertical change of skeletal landmarks (Anterior Nasal Spine, Subspinale, Prosthion, Incision Superious). In addition, there were no significance in horizontal movement of the skeletal landmarks among groups. In terms of hard tissue landmarks, group 3(maxillary posterior impaction and advancement surgery group) showed significantly greater change in the vertical movement of Anterior Nasal Spine(ANS), Subspinale(A), Prosthion(Pr), and Incision Superious(Is) compared with other groups. In terms of soft tissue change, group 3 showed more significant change in the vertical movement of Ls and Stm. This study calculated the changes of the skeletal and soft tissue landmarks in order to act as a guide in planning and performing the surgery and as a reference in predicting the postoperative change of facial appearance.

• Spatial Information Research
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• 제11권4호
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• pp.371-389
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• 2003

이 연구는 사이버국토의 개념을 학문적으로 정립하고 사이버국토의 구성요소를 도출한 후, 전국을 대상으로 한 사이버국토 구축 전략과 방안을 제시하는 데 목적을 두고 있다. 이 연구에서 사이버국토란 지상과 지하 그리고 바다를 포함한 국토전체를 비롯하여 국토에 설치된 각종 시설물과 건축물을 현실세계와 유사하게 디지털화 해 놓은 가상현실에서 국토를 체계적으로 관리하고 공공기관의 디지털 행정과 정책을 실현하며 기업의 경제활동과 국민의 일상생활까지 담을 수 있는 역동적인 제 2의 국토로서, 시공자재(時空自在)의 세상을 열기 위한 국가의 정보기반시설이라 정의한다. 이러한 사이버국토의 구축에는 10년 이상의 오랜 기간이 필요하므로 범정부 차원의 장기계획 하에 각급 지방자치단체에서 추진하는 것이 바람직하다.

• The Journal of Advanced Prosthodontics
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• 제1권2호
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• pp.68-74
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• 2009

STATEMENT OF PROBLEM. When veneering composite resin-metal restoration is prepared, the fact that bond strength between Ti and composite resin is relatively weak should be considered. PURPOSE. The purpose of this study is to evaluate the shear bond strength between the veneering composite resin and commercial pure (CP) Ti / Ti-6Al-4V alloy according to the method of surface treatment. MATERIAL AND METHODS. The disks were cast by two types of metal. Their surfaces were treated by sandblasting, metal conditioner, TiN coating and silicoating respectively. After surface treatment, the disks were veneered by composite resin (Tescera$^{TM}$, Bisco, USA) which is 5 mm in diameter and 3 mm in thickness. The specimens were stored in water at $25^{\circ}C$ for 24 hours, and then evaluated for their shear bond strength by universal testing machine (STM-$5^{(R)}$, United Calibration, USA). These values were statistically analyzed. RESULTS. 1. All methods of surface treatment were used in this study satisfied the requirements of ISO 10477 which is the standard of polymer-based crown and bridge materials. 2. The metal conditioner treated group showed the highest value in shear bond strength of CP Ti, silicoated group, TiN coated group, sandblasted group, in following order. 3. The silicoated group showed the highest value in shear bond strength of Ti-6Al-4V alloy, metal conditioner treated group, sandblasted group, TiN coated group, in following order. CONCLUSION. Within the limitations of this study, all methods of surface treatment used in this study are clinically available.

• 대한치과기공학회지
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• 제39권3호
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• pp.161-167
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• 2017

Purpose: We compare the bond strength of heat-cured PMMA of Lucitone 199 and QC-20 and Tokuyama Rebase Resin of self-cured resin, which are widely used and well accepted in clinical practice. In order to test the mechanical bonding and chemical bonding, we will compare the bond strength between EstheShot Bright, Smiletone, Repair and Rebase resins. Methods: The denture base resin used in this study was PMMA heat-cured QC-20 and Lucitone 199, polyamide resin EstheShot Bright, Smiletone. And Two types of self-curing Rapid Repair and Tokuyama Rebase were used as resection resins. To measure the bond strength, the denture specimens were fabricated in the size of $10{\times}64{\times}3.5mm$ as instructed by the manufacturer. A surface treatment agent was applied to the cut surfaces of each denture specimen, and the specimens were placed in a preformed silicone mold, and autoclaved excimer resins were prepared. The bending strength of the fabricated specimens was measured using a universal testing machine (STM-5, United Calibration Co., U.S.A.) to measure the three-point bending strength. Results: In both polycarbonate and polyacetal resin, a special resin surface treatment agent showed higher bonding strength than the resin surface treatment agent(p<0.05). Regardless of the type of surface treatment, polycarbonate showed higher bond strength than polyacetal resin(p<0.05). Conclusion: It is considered desirable to use a special surface treating agent for the thermoplastic denture base resin such as polycarbonate and polyacetal resin.

• 융합정보논문지
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• 제10권9호
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• pp.200-205
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• 2020

본 연구는 도구를 이용한 연부조직 가동술(IASTM)과 도수 근막이완술(MFR)이 위팔두갈래근의 근활성도에 미치는 영향을 알아보기 위해 수행하였다. 본 연구는 20대 성인 남녀 10명을 대상으로 하였고, 모든 대상자는 3일 동안 실험에 참석하여 위팔갈래근의 근활성도를 측정하였다. 첫 날은 중재 전 근활성도 값을 측정하였고, 남은 이틀은 임의의 순서로 각각의 수기요법을 중재 후 근활성도를 측정하였다. 모든 근활성도 값은 대응t검정과 독립t검정을 통해 비교 분석되었다. 본 연구의 결과에 따르면 두 중재(IASTM, MFR) 모두 중재 전후로 유의하게 위팔두갈래근의 근활성도가 증가하였고, 중재 후 집단간 근활성도 값의 유의한 차이는 없었다. 두 수기요법(IASTM, MFR) 모두 신경근 조절 능력의 증진에 효과적임으로 사료된다.