• Title/Summary/Keyword: Self-Alignment

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Fabrication Thermal Responsive Tunable ZnO-stimuli Responsive Polymer Hybrid Nanostructure

  • Lee, Jin-Su;Nam, Sang-Hun;Yu, Jung-Hun;Hwang, Ki-Hwan;Ju, Dong-Woo;Jeon, So-Hyoun;Seo, Hyeon-Jin;Yun, Sang-Ho;Boo, Jin-Hyo
    • Proceedings of the Korean Vacuum Society Conference
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    • 2014.02a
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    • pp.429.2-429.2
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    • 2014
  • ZnO nanowire is known as synthesizable and good mechanical properties. And, stimuli-responsive polymer is widely used in the application of tunable sensing device. So, we combined these characteristics to make precise tunable sensing devise. In this work, we investigate the dependence of ZnO nanowire alignment and morphology on si substrate using nanosphere template with various conditions via hydrothermal process. Also, pH-temperature dependant tuning ability of nanostructure was studied. The brief experimental scheme is as follow. First, Zno seed layer was coated on a si wafer ($20{\times}20mm$) by spin coater. And then $1.15{\mu}m$ sized close-packed PS nanospheres were formed on a cleaned si substrate by using gas-liquid-solid interfacial self-assembly method. After that, zinc oxide nanowires were synthesized using hydrothermal method. Before the wire growth, to specify the growth site, heat treatment was performed. Finally, NIPAM(N-Isopropylacrylamide) was coated onto as-fabricated nanostructure and irradiated by UV light to form the PNIPAM network. The morphology, structures and optical properties are investigated by FE-SEM(Field Emission Scanning electron Microscopy), XRD(X-ray diffraction), OM(Optical microscopy), and WCA(water contact angle).

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Design and Performance Evaluation of Carbon Fiber/Epoxy Composite-aluminum Hybrid Wheel for Passenger Cars (자동차용 탄소섬유/에폭시 복합재료-알루미늄 하이브리드 휠 설계 및 성능평가)

  • Hong, Jin-Ho;Yoo, Seong-Hwan;Chang, Seung-Hwan
    • Composites Research
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    • v.26 no.6
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    • pp.386-391
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    • 2013
  • In this paper, a carbon fiber/epoxy composite-aluminum hybrid wheel for passenger cars was suggested for better performance and a prototype was fabricated and tested. Adhesive bonding between aluminum part and a composite rim part was used, and the bonding length and thickness were determined by finite element analysis. For self alignment and the function of bonding jig the special structure with a groove and a protrusion was applied. To evaluate the performance of the hybrid wheel various FE analyses were carried out. Inner and outer molds were prepared for the composite rim part and the thermoformed composite part was bonded to the aluminum part. Vibration tests revealed that the hybrid wheel had 16% higher resonance frequency and 32% higher damping capacity with 10% weight reduction.

Thermopower Wave in Core-Shell Structures of Carbon Nanotube Chemical Fuels (나노튜브/화학연료의 동축 구조에서 생성되는 열동력 파도를 이용한 전기 에너지 생성)

  • Choi, Wonjoon;Strano, Michael S.
    • Transactions of the Korean Society of Mechanical Engineers B
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    • v.37 no.6
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    • pp.615-620
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    • 2013
  • There is considerable interest in developing energy sources capable of larger power densities. In our previous works, we proved that by coupling an exothermic chemical reaction with 1D nanostructures, a self-propagating reactive wave can be driven along its length with a concomitant electrical pulse of high specific power, which we identified as a thermopower wave. Herein, we discuss details about many different aspects of a thermopower wave. Different alignment degree in vertically aligned CNT films is evaluated in the reactive wave speed and correlated with its thermal reaction that affects the change in the magnitude of energy generation. The effects of the temperature-dependent properties of chemical fuels and CNTs are evaluated. Furthermore, we explore the convection and radiation portions in this thermal wave as well as the synchronization between the thermal reaction transfer and the oscillation of the electrical signal.

Development of An Automated Scanning Laser Doppler Vibrometer for Measurements of In-Plane Structural Vibration (평면 구조 진동 측정을 위한 자동화된 스캐닝 레이저 도플러 진동측정기의 개발 및 연구)

  • Kil, Hyun-Gwon
    • Journal of KSNVE
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    • v.7 no.2
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    • pp.231-238
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    • 1997
  • An automated scanning laser Doppler vibrometer (LDV) has been designed, and built to measure in-plane vibration fields over structures. Use of optical fibers allows the compact design of a laser probe head which can be scanned over the vibrating structures. An algorithm for automated self-alignment of the laser probe is developed. The system is completely automated for scanning over the structures, focusing two laser beams at each data point until the detected vibration signal is stable, and for recording and transferring the data to a system computer. The automated system allows one to get extensive data of the vibration field over the structures. The system is tested by scanning a piezoelectric cylindrical shell and a plate excited by a continuous signal and by a pulse signal, respectively. Results show that the automated scanning LDV system can be a useful tool to measure the in-plane vibration field and to detect the elastic waves propagating on the vibrating structures.

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Molecular Characterization of Legionellosis Drug Target Candidate Enzyme Phosphoglucosamine Mutase from Legionella pneumophila (strain Paris): An In Silico Approach

  • Hasan, Md. Anayet;Mazumder, Md. Habibul Hasan;Khan, Md. Arif;Hossain, Mohammad Uzzal;Chowdhury, A.S.M. Homaun Kabir
    • Genomics & Informatics
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    • v.12 no.4
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    • pp.268-275
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    • 2014
  • The harshness of legionellosis differs from mild Pontiac fever to potentially fatal Legionnaire's disease. The increasing development of drug resistance against legionellosis has led to explore new novel drug targets. It has been found that phosphoglucosamine mutase, phosphomannomutase, and phosphoglyceromutase enzymes can be used as the most probable therapeutic drug targets through extensive data mining. Phosphoglucosamine mutase is involved in amino sugar and nucleotide sugar metabolism. The purpose of this study was to predict the potential target of that specific drug. For this, the 3D structure of phosphoglucosamine mutase of Legionella pneumophila (strain Paris) was determined by means of homology modeling through Phyre2 and refined by ModRefiner. Then, the designed model was evaluated with a structure validation program, for instance, PROCHECK, ERRAT, Verify3D, and QMEAN, for further structural analysis. Secondary structural features were determined through self-optimized prediction method with alignment (SOPMA) and interacting networks by STRING. Consequently, we performed molecular docking studies. The analytical result of PROCHECK showed that 95.0% of the residues are in the most favored region, 4.50% are in the additional allowed region and 0.50% are in the generously allowed region of the Ramachandran plot. Verify3D graph value indicates a score of 0.71 and 89.791, 1.11 for ERRAT and QMEAN respectively. Arg419, Thr414, Ser412, and Thr9 were found to dock the substrate for the most favorable binding of S-mercaptocysteine. However, these findings from this current study will pave the way for further extensive investigation of this enzyme in wet lab experiments and in that way assist drug design against legionellosis.

S&T Collaboration in Developing Countries: Lessons from Brazilian Collaboration Activities with South Korea

  • Fink, Daniel;Hameed, Tahir;So, Minho;Kwon, Youngsun;Rho, Jae Jeung
    • STI Policy Review
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    • v.3 no.2
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    • pp.92-110
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    • 2012
  • An active policy role is suggested for collaboration that will enhance national level Science and Technology (S&T) capabilities. In contrast, some studies see a limited role of policy support for collaborative S&T research at the individual level (including research groups or institutional levels) due to their self-organizing nature. Two views on S&T collaboration look at different levels but existing research largely ignores the context of developing countries. This paper shows how S&T collaborations between Brazil and Korea have developed over the past two decades. The paper indicates the gaps between initiation and the actual establishment of collaborative research at national and individual levels, differences in the focus areas of research, differences in resources and project planning, and the nature of collaborations. Collaborative research activities at the national level were initiated before the individual level but activated later than the individual level; in addition, the focus areas of research were laid down earlier at the national level with individual collaborations focused on different areas. Project types remained different at each level (i.e. top-down and bottom-up) or with a slightly changing mix. This study suggests appropriate policy measures (such as the timely and effective information collection of activities at different levels and proactive coordination) that could reduce the gaps in the timing and alignment of research areas. This paper also alludes to an evolutionary model to develop S&T collaboration among developing countries.

A Critical Review on Platform Business and Government Regulation Alignment (디지털경제 시대의 플랫폼비즈니스와 정부규제에 관한 리뷰: 디지털플랫폼 속성과 정부규제 유형을 중심으로)

  • Sungsoo Hwang;Sung-Geun Kim;Junghyun Yoon
    • Informatization Policy
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    • v.30 no.1
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    • pp.3-22
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    • 2023
  • This review article summarizes the issues around platform business with government regulation. We illustrated types and characteristics of platform business. We examined the current policy tools and government activities for regulating platform business in a digital economy. Policy tools of government regulation for platform business are not suitable or fit at times. We suggest an approach to look at the fit of platform business types and regulation policy tools. We also offer a policy recommendation to define situations whether to focus on minimizing conflicts among stakeholder or invite them to participate in anticipatory decision making process for new technology market.

DEVELOPMENT OF LIGHTWEIGHT OPTICAL TELESCOPE KIT USING ALUMINUM PROFILE AND ISOGRID STRUCTURE

  • Park, Woojin;Lee, Sunwoo;Han, Jimin;Ahn, Hojae;Ji, Tae-Geun;Kim, Changgon;Kim, Dohoon;Lee, Sumin;Kim, Young-Jae;Kim, Geon-Hee;Kim, Junghyun;Kim, Ilhoon;Pak, Soojong
    • Journal of The Korean Astronomical Society
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    • v.55 no.1
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    • pp.11-22
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    • 2022
  • We introduce the Transformable Reflective Telescope (TRT) kit that applies an aluminum profile as a base plate for precise, stable, and lightweight optical system. It has been utilized for optical surface measurements, developing alignment and baffle systems, observing celestial objects, and various educational purposes through Research & Education projects. We upgraded the TRT kit using the aluminum profile and truss and isogrid structures for a high-end optical test device that can be used for prototyping of precision telescopes or satellite optical systems. Thanks to the substantial aluminum profile and lightweight design, mechanical deformation by self-weight is reduced to maximum 67.5 ㎛, which is an acceptable misalignment error compared to its tolerance limits. From the analysis results of non-linear vibration simulations, we have verified that the kit survives in harsh vibration environments. The primary mirror and secondary mirror modules are precisely aligned within 50 ㎛ positioning error using the high accuracy surface finished aluminum profile and optomechanical parts. The cross laser module helps to align the secondary mirror to fine-tune the optical system. The TRT kit with the precision aluminum mirror guarantees high quality optical performance of 5.53 ㎛ Full Width at Half Maximum (FWHM) at the field center.

Introducing a New Pedagogical Approach for Ergonomic Pattern Education: Leveraging a Half-Scale Body Form Based on 3D Modeling (인체공학적 패턴 교육을 위한 새로운 교수법 제안: 3D 모델링 기반으로 제작한 Half Scale Body Form를 이용하여)

  • Lin Chen;Yuhwa Hong;Juyeon Park
    • Fashion & Textile Research Journal
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    • v.26 no.1
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    • pp.78-87
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    • 2024
  • This study aimed to propose an innovative teaching pedagogy using a half-scale body form in apparel design education and evaluate its effectiveness in augmenting students' understanding of ergonomic patterns. Constructed in alignment with Phoenix's (2018) study, which used 3D body scanning and digital editing software, the half-scale body form was created through a five-step process, encompassing body measurement, 3D body modeling, fabrication of a physical half-scale body form, pattern making, and evaluation. Implemented in an undergraduate patternmaking course offered at a 4-year university in the metropolitan Seoul, this instructional approach's effectiveness was gauged through students' course projects and exit interviews. The results underscored the positive impact of the proposed teaching pedagogy on students' grasp of ergonomic pattern development, fostering a keen understanding of diverse body shapes and sizes and the relationship between the human body and garments. Furthermore, it played a role in cultivating positive body image and self-endorsement among students. The research contributes meaningfully by presenting a fresh perspective in apparel design education, seamlessly integrating advanced anthropometric and technological tools into a conventional patternmaking classroom. It offers a novel learning experience for students majoring in apparel, creating a fun and interactive teaching environment.

Process Governance Meta Model and Framework (프로세스 거버넌스 메타모델과 프레임워크)

  • Lee, JungGyu;Jeong, Seung Ryul
    • Journal of Internet Computing and Services
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    • v.20 no.4
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    • pp.63-72
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    • 2019
  • As a sub-concept of corporate or organization governance, business governance and IT governance have become major research topics in academia. However, despite the importance of process as a construct for mediating the domain between business and information technology, research on process governance is relatively inadequate. Process Governance focuses on activities that link business strategy with IT system implementation and explains the creation of corporate core values. The researcher studied the basic conceptual governance models of political science, sociology, public administration, and classified governance styles into six categories. The researcher focused on the series of metamodels. For examples, the traditional Strategy Alignment Model(SAM) by Henderson and Venkatraman which is replaced by the neo-SAM model, organizational governance network model, sequential organization governance model, organization governance meta model, process governance CUBE model, COSO and process governance CUBE comparison model, and finally Process Governance Framework and etc. The Major difference between SAM and neo-SAM model is Process Governance domain inserted between Business Governance and IT Governance. Among several metamodels, Process Governance framework, the core conceptual model consists of four activity dimensions: strategic aligning, human empowering, competency enhancing, and autonomous organizing. The researcher designed five variables for each activity dimensions, totally twenty variables. Besides four activity dimensions, there are six driving forces for Process Governance cycle: De-normalizing power, micro-power, vitalizing power, self-organizing power, normalizing power and sense-making. With four activity dimensions and six driving powers, an organization can maintain the flexibility of process governance cycle to cope with internal and external environmental changes. This study aims to propose the Process Governance competency model and Process Governance variables. The situation of the industry is changing from the function-oriented organization management to the process-oriented perspective. Process Governance framework proposed by the researcher will be the contextual reference models for the further diffusion of the research on Process Governance domain and the operational definition for the development of Process Governance measurement tools in detail.