• 한국기계가공학회지
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• 제20권8호
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• pp.52-59
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• 2021

In this study, we experimentally evaluated the mechanical properties and geometric form accuracy in FDM 3D printing processes based on the printing direction, building direction, and layer thickness. The specimen test results showed that the tensile strength increased by over 33% in the printing direction compared to the direction perpendicular to printing and the tensile strength becomes larger as the layer thickness decreased. Furthermore, the tensile and impact strengths in the building direction were significantly reduced due to the difference in the interlayer joining and bonding strengths of the fused material. Additionally, shrinkage of the material due to phase change induced curl distortion especially in thin and long 3D-printed products, which increased as the layer thickness increased.

• 한국컴퓨터정보학회:학술대회논문집
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• 한국컴퓨터정보학회 2022년도 제66차 하계학술대회논문집 30권2호
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• pp.567-568
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• 2022

헤어 시뮬레이션은 수많은 가닥으로 구성되어 있으며, 헤어 동역학을 기반으로 계산되기 때문에 일반적으로 계산양이 큰 범주에 속한다. 뿐만 아니라 곱슬머리 형태를 유지하려는 제약은 더 큰 계산을 요구하며, 본 논문에서는 수분에 의해 곱슬머리가 젖었을 때 표현되는 구부러짐과 수축을 모델링 할 수 있는 새로운 알고리즘을 제시한다. 이전 연구에서는 곱슬머리에 대한 헤어 시뮬레이션은 곱슬머리의 회전(Curl)형태를 유지하려는 알고리즘을 제안했지만, 강한 외력에 의한 회전형태만을 유지하려고 했으며, 수분이나 열에 의한 곱슬머리의 상태변화는 고려하지 못했다. 따라서 본 논문에서는 IIR(Infinite impulse response) 필터로 스무딩된 헤어 커브를 따라 회전의 수직 성분을 추출하여 회전의 세로방향 신축성을 제어할 수 있는 방법을 제안한다. 우리의 헤어 모델은 곱슬머리의 회전과 신축성을 제어하기 위해 스프링 동역학을 사용하며, 젖은 헤어의 부분적인 상태 변화에도 안정적으로 표현할 수 있음을 보여준다.

• 한국펄프종이공학회:학술대회논문집
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• 한국펄프종이공학회 2004년도 제30회 국제세미나
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• pp.93-133
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• 2004

• The Plant Pathology Journal
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• 제18권4호
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• pp.179-186
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• 2002

Four newly developed cotton mutants (M-111, M-7662, M-358 and M-218) were compared for their resistance against Cotton leaf curl virus(CLCuV) together with commercial resistant (CIM-443, CIM-482, CIM-473, FH-900 and FH-901) and susceptible (5-12) varieties by artificial inoculation through grafting and under natural field conditions. Infectivity and success of grafting were 100% in all cases. None of the grafted plants were found immune or asymptomatic. All the grafted mutants and most of their single plant progeny rows (SPPRs) showed highly resistant responses as the symptoms displayed by these mutants were milder than the commercial cultivars. Grafted mutants also had delayed disease reactions as they took more time (25-30 days) to produce disease symptoms, as compared with resistant commercial varieties that produced disease 18-22 days after inoculation. Growth of the grafted SPPRs of tested mutants was normal, which is an indication that there will be no production losses. Observations under natural infestation of whitefly showed that two SPPRs of M-ll/CE and M-7662-1/2 and one resistant variety CIM-443 exhibited slight incidence of disease, while one SPPR of M-l1/59 and S-12 were moderately susceptible and highly susceptible with 21％ and 97.l％ disease incidence, respectively. This study also showed that plants displaying more disease symptoms through grafting were easily infected under natural conditions. These results suggest that preference should be given to those plants that exhibited highly resistant responses after artificial inoculation.

• 대한의용생체공학회:의공학회지
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• 제28권6호
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• pp.825-831
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• 2007

An elbow orthosis with a pneumatic rubber actuator has been developed to assist and enhance upper limb movements and has been examined for the effectiveness. The effectiveness of the elbow orthosis was examined by comparing muscular activities during alternate dumbbell curl exercises with and without the orthosis. The subjects participated in the experiment were younger adults in their twenties. The subjects were instructed to perform dumbbell curl motion in a sitting position with and without orthosis in turn and a dynamometer was used to measure elbow joint torque outputs in an isovelocity mode. The measurements were done with four various dumbbell loads: 0 kg, 1 kg, 3 kg, and 5 kg. The orthosis was pneumatically actuated and controlled in a passive mode. The most comfortable air pressure to the pneumatic actuator was determined to be 0.294MPa. Electromyography(EMG) was also measured during curl exercises. The muscles of interest were biceps brachii(BB), triceps brachii(TB), brachioradialis(Bo), and flexor carpi ulnaris(FCU) in the upper limbs. The experimental results showed that the muscular activities themselves significantly reduced with elbow orthosis on in performing similar activities without orthosis. As a result of this experiment, the effectiveness of the developed upper limb orthosis was confirmed and the level of assistance was quantified.

• Ocean and Polar Research
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• 제31권1호
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• pp.11-29
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• 2009

Variability of sea surface temperature (SST) in the Japan/East Sea (JES) was studied using complex empirical orthogonal function (CEOF) analysis. Two daily data sets were analyzed: (1) New Generation 0.05o-gridded SST from Tohoku University, Japan (July 2002-July 2006), and (2) 0.25o-gridded SST from the Japan Meteorological Agency (October 1993-November 2006). Linkages with wind stress curl were revealed using 6-h 1o-gridded surface zonal and meridional winds from ancillary data of the Sea- WiFS Project, a special National Centers for Environmental Prediction/National Center for Atmospheric Research (NCEP/NCAR) product (1998-2005). SST anomalies (SSTA) were obtained by removing the seasonal signal, estimated as the leading mode of the CEOF decomposition of the original SST. Leading CEOF modes of residual SSTA obtained from both data sets were consistent with each other and were characterized by annual, semiannual, and quasi-biennial time scales estimated with 95% statistical significance. The Semiannual Mode lagged 2 months behind the increased occurrence of the anticyclonic (AC) wind stress curl over the JES. Links to dynamic processes were investigated by numerical simulations using an oceanic model. The suggested dynamic forcings of SSTA are the inflow of subtropical water into the JES through the Korea Strait, divergence in the surface layer induced by Ekman suction, meridional shifts of the Subarctic Front in the western JES, AC eddy formation, and wind-driven strengthening/weakening of large-scale currents. Events of west-east SSTA movement were identified in July-September. The SSTA moved from the northeastern JES towards the continental coast along the path of the westward branch of the Tsushima Current at a speed consistent with the advective scale.

• The Plant Pathology Journal
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• 제18권5호
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• pp.231-236
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• 2002

Bemisia tabaci Genn. is an important pest worldwide because of its ability to cause damage by direct feeding and its role as a vector of some viruses including geminiviruses. The first report of Tobacco leaf curl virus (TLCV), a Geminiviruses, in Indonesia was in 1932 when the virus was found infecting tobacco plants in Central Java. The characteristic symptoms of TLCV included upward curling of the leaf edge, vein thickening, and sometimes the occurrence of enation on the underside of the leaves. Basic studies were carried out to elucidate the characteristics of TLCV transmission by its vector, B. tabaci. A single whitefly was able to transmit the virus and the efficiency of transmission was increased when the number of adult whiteflies was increased up to 20 per plant. Inoculation access period of 1 h could cause transmission up to 20% and the optimum inoculation access period was 12 h. Acquisition access period of 30 minutes resulted in 70% transmission while 1(10% transmission occurred with a 24-h acqui-sition access period. The virus was proven to be persistently but not transovarially transmitted. Discrete fragments of 1.6 kb were observed when polymerase chain reaction method was applied to detect the virus in viruliferous nymphs and individual adults of B. tabaci, while no bands were obtained from non-viruliferous nymphs and adults.

• The Plant Pathology Journal
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• 제31권2호
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• pp.132-139
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• 2015

Bt-cotton germplasm, consisting of 75 genotypes was evaluated against cotton leaf curl disease (CLCuD) under high inoculum pressure in the field and using graft inoculation in glasshouse by visual symptom scoring assessments. None of the tested genotype was found disease free under both evaluation tests. Under field conditions in 2011, 3 genotypes were found resistant, 4 moderately resistant, 3 tolerant, 2 moderately susceptible and one susceptible; in 2012, 3 genotypes were tolerant, 7 moderately susceptible, 5 susceptible and 38 highly susceptible; in 2013, one was moderately susceptible and 51 were highly susceptible with varying degree of percent disease index (PDI) and severity index (SI). However, through graft evaluation in glasshouse, none of the graft inoculated plant was symptomless. All tested genotypes showed disease symptoms with SI values ranging between 5.0 and 6.0, and latent period between 12 and 14 days. Of the 75 genotypes evaluated using graft inoculation, 11 were found susceptible with SI values of 5.0 to 5.4 while remaining 64 were highly susceptible with SI values of 5.5 to 6.0. Inoculated plants of all tested genotypes exhibited severe disease symptoms within 10 days after the appearance of initial symptoms. No reduction in SI value was observed until the end of the experiment i.e., 90 days after grafting. Information generated under the present study clearly demonstrates that no sources of resistance to CLCuD are available among the tested Bt-cotton genotypes. So, a breeding programme is needed to introgress the CLCuD-resistance from other resistant sources to agronomically suitable Bt-cotton genotypes.

• 펄프종이기술
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• 제32권1호
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• pp.10-18
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• 2000

To improve the physical properties of OCC (Old Corrugated Container) fibers, we used the mechanical pre-treatment on the fibers before refining . The mechanical action in the Hobart mixer induced high shear and compression on the fibers, which resulted in changes of fiber internal structure, and microcompressions on the surface of the fibers. We evaluated the amount of mechanical treatment on the fibers by fiber curl index for convenience. Four different refining techniques were applied to the pre-treated fibers (valley beater, Kady mill, PFI mill, and Impact refining) to find the best combination of the pre-treatment and the refining methods. Conclusions were summarized as followed. 1. Mechanical pre-treatment in Hobart mixer for more than 1 hour caused the increase of curl index of OCC fibers, and increased breaking length, burst index, and tear index the handsheets more than 10 % in this experiment. 2. Kady mill and PFI mill refining were effective in keeping fiber length from shortening Kady mill and Valley beater refining straightened out the fiber curls, and reduced the curl index. 3. Valley beating reduced fiber length very fast and generated fines more than other refining methods. 4. To increase breaking length and burst strength while keeping tear strength , combination of mechanical pre-treatment and Valley beating were most effective.

• 패션비즈니스
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• 제12권6호
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• pp.1-10
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• 2008

Public interest in healthy hairs gets growing as damaged hairs are seen more frequently with the generalization of heat permanent waves. For this study, experiments have been conducted to understand the influences on the changes in physical and morphological features of wave forms and damaged hairs, by collecting virgin hairs from the women in their mid-20's, who had not experienced chemical applications, and by dividing the applications of heat perm hair treatments, PPT(for pre-treatment) and LPP(for post-treatment), into the pre-treatment, the post-treatment, the pre & post-treatment, and the non-treatment. For the wave formations, curl waves were investigated by the bare eyes using the pictures taken by a digital camera. For the comparison of physical features, the experiments of tensile strength and elongation were done and their mean values were found. For the observations of morphological features, the pictures were taken by SEM for comparison. As for the findings, regarding the curl wave shapes of hairs, the most even and elastic S curl was formed in the case of non-treatment. In the physical features, both of the tensile strength and elongation showed a decreasing tendency in line with the hair damage levels, and the case of the pre & post-treatment indicated the tendency most similar to the control group. In the morphological features of the cuticle, observed with an SEM, the pre-treatment showed the higher possibility of reducing the cuticle damages than the post-treatment did. LPP was found to play the role of protective membrane for the post-treatment, and the pre & post-treatment turned out to reduce most effectively the cuticle damages.