• 한국정밀공학회:학술대회논문집
• /
• 한국정밀공학회 2005년도 추계학술대회 논문집
• /
• pp.689-693
• /
• 2005

Inkjet printing is a non-contact and direct writing associated with a computer. In the industrial field, there have been many efforts to utilize the inkjet printing as a new way of manufacturing, especially for electronic devices. For the application of inkjet printing to electronic field, one of the key factors is exact realization of designed images into printed patterns. In this work, micro patterning for conducting line has been studied using the piezoelectric print head and silver nano ink. Dimensions of printed images have been predicted in terms of print resolution and diameter of a single dot. The predicted and the measured values showed consistent results. Using the results, the design capability for industrial inkjet printing could be achieved.

• 한국레이저가공학회지
• /
• 제10권2호
• /
• pp.5-15
• /
• 2007

A new printing process for LCD color filter is proposed in this work by using the localized laser heating, which is called laser-induced spray printing (LISP) process. The LISP is a non-contact process, which injects the ink from the donor substrate to the glass substrate by the bubble pressure induced by laser heating. The temperature distribution of the donor substrate is calculated numerically to explain the ink ejection phenomena. The composition of the ink was includes the red pigment, n-butanol, xylene, BCA and epoxy. Experiments were conducted by using the fiber laser system, and the color filter patterns were deposited successfully under the proper laser heating conditions.

• 한국어교육
• /
• 제28권1호
• /
• pp.141-171
• /
• 2017

This study investigates Korean language teachers' perception/beliefs and practices in written feedback. Two types of data were collected: (1) teachers' feedback on three compositions by elementary-level learners, and (2) a survey questionnaire. The result showed that teachers perceived written feedback to be important even though they had not enough opportunities to receive appropriate training. Lack of training brought about limited feedback in terms of both quantity and quality, and inconsistency between their beliefs and practice. This study closes with the needs for teacher training and further studies on teachers' feedback practices.

• 한국재료학회지
• /
• 제34권3호
• /
• pp.144-151
• /
• 2024

This work focuses on the fabrication of excellent magnetic structures for trapping breast cancer cells. Micromagnetic structures were patterned for trapping cancer cells by depositing 30 nm of permalloy on a silicon substrate. These structures were designed and fabricated using two fabrication techniques: electron beam lithography and laser direct writing. Two types of magnetic structures, rectangular wire and zig-zagged wire, were created on a silicon substrate. The length of each rectangular wire and each straight line of zig-zagged wire was 150 ㎛ with a range of widths from 1 to 15 ㎛ for rectangular and 1, 5, 10 and 15 ㎛ for zigzag, respectively. The magnetic structures showed good responses to the applied magnetic field despite adding layers of silicon nitride and polyethylene glycol. The results showed that Si + Si₃N₄ + PEG exhibited the best adhesion of cells to the surface, followed by Si + Py + Si₃N₄ + PEG. concentration of 5-6 with permalloy indicates that this layer affected silicon nitride in the presence of Polyethylene glycolPEG.

• 대한방사선기술학회지:방사선기술과학
• /
• 제36권2호
• /
• pp.99-110
• /
• 2013

현재 방사선 분야가 사회의 중요한 직업군으로 성장하기 위한 전문적인 방사선사 양성교육의 필요성이 강조되고 있다. 또한 대부분의 병원 및 기업에서는 급변하는 대내외적 환경에서 능동적으로 대처하고 보다 깊이 있는 전문가 양성을 위해서 논문에 대한 중요성이 높아지고 있으며, 급변하는 외부상황에 보다 능동적으로 대처할 수 있는 새로운 교수학습모형의 도입이 필요성이 대두되고 있다. 논문작성 수업은 정해진 프로그램에만 의존하여 시간적 제약과 수동적인 참여가 불가피하여 깊이 있는 교육 및 학습에 한계를 가져왔다. 그리고 작성한 논문에 대하여 다양한 발표기회를 갖지 못하고 있으며, 강의 중심의 수업으로 실제 작성하고 논의 할 수 있는 기회가 많이 제공되지 못하였다. 이는 논문의 질에도 직접적인 영향을 미칠 뿐 아니라 다양한 학술대회 참여기회를 가지는데 한계점으로 나타났으며, 궁극적으로 산업체와 연계에도 긍정적 영향을 주지는 못하였다. 이러한 문제점을 개선하기 위해서 본 연구에서는 논문 작성을 일관성 있는 점진적 심화학습으로 교육운영을 편성함과 동시에 연계성 있는 통합 운영을 기반으로 운영상의 아이디어를 제안하고 실제 논문작성 수행능력 향상을 위한 효율적인 교육프로그램과 학습지도도구를 개발 적용하였다. 개발한 교수학습모형은 모델링(modeling), 발판화(scaffolding), 명료화(articulation), 탐색(exploration)으로 4단계의 시스템으로 구성하였다. 교과목의 특성에 따라 연계교과를 고려하여 개인의 관심도와 주제에 따라 팀을 구성하고 이를 바탕으로 단계별 평가와 피드백을 통해 연구역량을 증진하고, 저널스터디(journal study)를 통하여 문제해결 능력을 근본적으로 강화하고, 위키스페이스(wiki-space)를 활용하여 실시간의 문제해결을 돕고 효율적인 시간활용을 도우며, 멘토링(mentoring)을 통해 산학협력을 활성화하여 논문의 질을 높이며, 긍정적인 산과 학의 협력관계를 도모하게 하였다. 지원시스템에서는 크게 3단계로 주제 기획, 진행 및 작성, 논문작성 및 발표로 구성되었으며, 이는 인지적 도제를 기반으로 하고 있다. 이러한 활동을 원활하게 유지하기 위해 교수자와 전문가의 지속적인 코칭(coaching)과 성찰(reflection)을 적용하였다. 본 연구를 통하여 학습자에게 실질적이고 능동적, 자발적 참여를 유도함으로써 창의성, 독창성의 향상과 공동업무 능력을 배양하고 지식기반의 전문성을 보다 강화함으로써 종합적으로 능력을 향상시키는데 도움이 되리라 사료된다.

• Macromolecular Research
• /
• 제17권3호
• /
• pp.197-202
• /
• 2009

Solution-based, direct-write patterning by an automated, computer-controlled, inkjet technique is of particular interest in a wide variety of industrial fields. We report the construction of three-dimensional (3D), micro-patterned structures by polymer inkjet printing. A piezoelectric, drop-on-demand (DOD) inkjet printing system and a common polymer, PVA (poly(vinyl alcohol)), were explored for 3D construction. After a systematic preliminary study with different solvent systems, a mixture of water and DMSO was chosen as an appropriate solvent for PVA inks. The use of water as a single solvent resulted in frequent PVA clogging when the nozzles were undisturbed. Among the tested polymer ink compositions, the PVA inks in a water/DMSO mixture (4/1 v/v) with concentrations of 3 to 5 g/dL proved to be appropriate for piezoelectric DOD inkjet printing because they were well within the proper viscosity and surface tension range. When a dot was printed, the so-called 'coffee-ring effect' was significant, but its appearance was not prominent in line printing. The optimal polymer inkjet printing process was repeated slice after slice up to 200 times, which produced a well-defined, 3 D micro-patterned surface. The overall results implied that piezoelectric DOD polymer inkjet printing could be a powerful, solid-freeform, fabrication technology to create a controlled 3D architecture.

• Journal of the Korean Academy of Child and Adolescent Psychiatry
• /
• 제18권1호
• /
• pp.58-65
• /
• 2007

Objectives : Motivational factor is a unique contributor to the typically poor academic performance of children with ADHD. However, few study has directly intervened learning motivation in children with ADHD. We conducted this study to explore the direct effects of the learning motivation improvement program applied to children with ADHD. Method The program was designed in order to increase an interest-inducing educational intervention, an academic skills integration, a basic learning activity (reading, writing, and math), and children's self-esteem. We conducted the program twice a week (total 10 sessions) and assessed learning motivation, teaming attitude, self-esteem, academic performance, and problem behaviors of participating children. Results : After the program, teachers reported improvement in teaming motivation. In addition, parents notified sisnificant reduction of problem behaviors. Children reported improvement in a few domains of teaming motivation and learning attitude. Conclusion : While loaming motivation is regarded as an important factor in education, there have been few studies considering this issue in both educational and psychiatric fields. The teaming motivation improvement would be needed in both field in order to reduce the deficits in academic performance in children with ADHD.

• 제어로봇시스템학회논문지
• /
• 제21권6호
• /
• pp.583-588
• /
• 2015

Flexible tactile sensors can provide valuable feedback to intelligent robots regarding the environment around them. This is especially important when robots such as, service robots share a workspace with humans. This paper presents a contact force measurement algorithm of a flexible tactile sensor. This sensor is manufactured by a direct-writing technique, which is one 3D printing method, using multi-walled carbon nano-tubes. An analog signal processing circuit has been designed and implemented to reduce noise contained in the sensor output. In addition, a digital version of the Butterworth filter was implemented by software running on a microcontroller. Through various experiments, characteristics of the sensor system have been identified. Based on three traits, an algorithm to detect the contact and measure the contact force has been developed. The entire system showed a promising prospect to detect the contact over a large and curved area.

• 한국정밀공학회:학술대회논문집
• /
• 한국정밀공학회 2004년도 추계학술대회 논문집
• /
• pp.590-595
• /
• 2004

The shape and size variations of the nanopatterns produced on a positive photoresist using a near-field scanning optical microscope(NSOM) are investigated with respect to the process variables. A cantilever type nanoprobe having a 100nm aperture at the apex of the pyramidal tip is used with the NSOM and a He-Cd laser at a wavelength of 442nm as the illumination source. Patterning characteristics are examined for different laser beam power at the entrance side of the aperture( $P_{in}$ ), scan speed of the piezo stage(V), repeated scanning over the same pattern, and operation modes of the NSOM(DC and AC modes). The pattern size remained almost the same for equal linear energy density. Pattern size decreased for lower laser beam power and greater scan speed, leading to a minimum pattern width of around 50nm at $P_{in}$ =1.2$\mu$W and V=12$\mu$m/. Direct writing of an arbitrary pattern with a line width of about 150nm was demonstrated to verify the feasibility of this technique for nanomask fabrication. Application on high-density data storage using azopolymer is discussed at the end.

• 한국재료학회:학술대회논문집
• /
• 한국재료학회 2003년도 추계학술발표강연 및 논문개요집
• /
• pp.71-71
• /
• 2003

Hot embossing has been widely accepted as an alternative to photolithography in generating patterns on polymeric substrates. The optimization of embossing process should be accomplished based on polymer substrate materials. In this paper, the effect of polymer substrates on nano scale hot embossing process was studied. Silicon molds with nano size patterns were fabricated by e-beam direct writing. Molds were coated with self-assembled monolayer (SAM) of (1, 1, 2.2H -perfluorooctyl)-trichlorosilane to reduce the stiction between mold and substrates. For an embossing, pressure of 55, 75 bur, embossing time of 5 min and temperature of above transition temperature were peformed. Polymethylmethacrylates (PMMA) with different molecular weights of 450,000 and 950,000, MR-I 8010 polymer (Micro Resist Technology) and polyaliphatic imide copolymer were applied for hot embossing process development in nano size. These polymers were spun coated on the Si wafer with the thickness between 150 and 200 nm. The nano size patterns obtained after hot embossing were observed and compared based on the polymer properties by scanning electron microscopy (SEM). The imprinting uniformity dependent on the Pattern density and size was investigated. Four polymers have been evaluated for the nanoimprint By optimizing the process parameters, the four polymers lead to uniform imprint and good pattern profiles. A reduction in the friction for smooth surfaces during demoulding is possible by polymer selection.