• Composites Research
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• 제25권6호
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• pp.178-185
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• 2012

본 연구에서는 기능성 나노복합재를 제작하는 방법이 제시되었다. 미소 입자들을 포함하고 있는 점성을 가진 유체에 전기장을 가하여 유체속에 포함된 입자들을 전기장의 방향에 따라 규칙적으로 배열을 하였다. FAiMTa 기술이라고 불리는 이 방법은 마이크로 혹은 나노 사이즈의 입자들을 체인의 형태로 배열하여 직교이방성 폴리머 나노복합재의 제작을 가능하게 하였다. 알루미나($Al_2O_3$), 탄소나노튜브(CNT), 탄소(Graphite), 텅스텐(W) 등의 마이크로 혹은 나노 사이즈 입자 분말을 사용하여 FAiMTa기술의 유효성을 확인하는 시험을 수행하였다. 이러한 입자들을 전기장을 사용하여 일정한 방향으로 배열하여 직교이방성 폴리머 복합재를 만들었고, 시험시편의 물리적 특성 즉 기계적 열적 특성을 측정하여 방향성을 확인하였다. 이렇게 제작된 첨단 나노복합재는 각종 산업분야에서 큰 효과가 기대된다.

• The Journal of Korean Physical Therapy
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• 제16권1호
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• pp.157-182
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• 2004

The purpose of this study was to evaluate effects of lumbar stabilizing exercise on the functional recovery and the range of motion of low back pain patients. The subjects were consisted of sixty patients who had non specific chronic low back pain(32 females. 28 males; mean aged 37.3) from 19 to 65 years of age(mean age : 37.3). All subjects randomly assigned to the lumbar stabilizing exercise group, the modalities treatment group, the manual treatment group. Lumbar stabilizing exercise group received manual treatment with lumbar stabilizing exercise for 30minutes, modalities treatment group received hot pack used thermal therapy for 20minutes and ICT used electrical therapy for 20minutes and US or MWD used deep thermal therapy for 15minutes, manual treatment group received modalities treatment with therapeutic massage for 10minutes and joint mobilization or manipulation for 10minutes per day and three times a week during 4 weeks period. The Multilevel Roland-Morris Disability Questionnaire(MR-MDQ) was used to measure functional disability level. Visual Analogue Scale(VAS) was used to measure subjective pain level. Remodified Schober test(RST) was used to measure forward flexion range of motion of lumbar segment. Finger-to-Floor test(F-T-FT) was used to measure forward flexion range of motion of full spine of low back pain patients. All measurements of each patients were measured at pre-treatment and 4 week post-treatment. The results of this study were summarized as follows : 1. The MR-MDQ of lumbar stabilizing exercise group, modalities treatment group, and manual treatment group was significantly reduced between pre-treatment and post-treatment(p<.05). 2. The VAS of lumbar stabilizing exercise group, modalities treatment group, and manual treatment group was significantly reduced between pre-treatment and post-treatment(p<.05). 3. The RST of lumbar stabilizing exercise group, modalities treatment group, and manual treatment group was significantly reduced between pre-treatment and post-treatment(p<.05). 4. The F-T-FT of lumbar stabilizing exercise group, modalities treatment group, and manual treatment group was significantly reduced between pre-treatment and post-treatment(p<.05). 5. The results of analyzed effects of MR-MDQ, RST, F-T-FT were significantly reduced (p<.05), but VAS wasn't significantly reduced(p>.05) between treatment type of lumbar stabilizing exercise group and modalities treatment group and manual treatment group according to pre-treatment and post-treatment. 6. The results of LSD post-hoc to find difference between treatment type of lumbar stabilizing exercise group and modalities treatment group and manual treatment group according to pre-treatment and post-treatment that MR-MDQ was significantly reduced stabilizing exercise group than modalities treatment group(p<.05), and VAS wasn't significantly reduced all treatment group(p>.05), and RST was significantly reduced stabilizing exercise group than modalities treatment group(p<.05), and F-T-FT was significantly reduced stabilizing exercise group than modalities treatment group and manual treatment group (p<.05).

• 한국진공학회:학술대회논문집
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• 한국진공학회 2013년도 제44회 동계 정기학술대회 초록집
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• pp.73-75
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• 2013

Atomic force microscopy (AFM) [1] can now not only image individual atoms but also construct atom letters using atom manipulation method [2]. Therefore, the AFM is the second generation atomic tool following the well-known scanning tunneling microscopy (STM). The AFM, however, has the advantages that it can image even insulating surfaces with atomic resolution and also measure the atomic force itself between the tip-apex outermost atom and the sample surface atom. Noting these advantages, we have been developing a novel bottom-up nanostructuring system, as shown in Fig. 1, based on the AFM. It can identify chemical species of individual atoms [3] and then manipulate selected atom species to the designed site one-by-one [2] to assemble complex nanostructures consisted of many atom species at room temperature (RT). In this invited talk, we will introduce our results toward atom-by-atom assembly of composite nanomaterials based on the AFM at RT. To identify chemical species, we developed the site-specific force spectroscopy at RT by compensating the thermal drift using the atom tracking. By converting the precise site-specific frequency shift curves, we obtained short-range force curves of selected Sn and Si atoms as shown in Fig. 2(a) and 2(b) [4]. Then using the atom-by-atom force spectroscopy at RT, we succeeded in chemical identification of intermixed three atom species in Pb/Sn/Si(111)-(${\surd}3$'${\surd}3$) surface as shown in Fig. 2(c) [3]. To create composite nanostructures, we found the lateral atom interchange phenomenon at RT, which enables us to exchange embedded heterogeneous atoms [2]. By combining this phenomenon with the modified vector scan, we constructed the atom letters "Sn" consisted of substitutional Sn adatoms embedded in Ge adatoms at RT as shown in Fig. 3(a)~(f) [2]. Besides, we found another kind of atom interchange phenomenon at RT that is the vertical atom interchange phenomenon, which directly interchanges the surface selected Sn atoms with the tip apex Si atoms [5]. This method is an advanced interchangeable single atom pen at RT. Then using this method, we created the atom letters "Si" consisted of substituted Si adatoms embedded in Sn adatoms at RT as shown in Fig. 4(a)~(f) [5]. In addition to the above results, we will introduce the simultaneous evaluation of the force and current at the atomic scale using the combined AFM/STM at RT.