• 반도체디스플레이기술학회지
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• 제15권2호
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• pp.26-31
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• 2016

The Townsend to glow discharge mode transition was investigated in the dielectric barrier discharge (DBD) helium plasma source which was powered by 20 kHz / $4.5 kV_{rms}$ high voltage at atmospheric pressure. The spatial profile of the electric field strength at each modes was measured by using the intensity ratio method of two helium emission lines (667.8 nm ($3^1D{\rightarrow}2^1P$) and 728.1 nm ($3^1S{\rightarrow}2^1P$)) and the Stark effect. ICCD images were analyzed with consideration for the electric field property. The Townsend discharge (TD) mode at the initial stage of breakdown has the light emission region located in the vicinity of the anode. The electric field of the light emitting region is close to the applied field in the system. Immediately, the light emitting region moves to the cathode and the discharge transits to the glow discharge (GD) mode. This mode transition can be understood with the ionization wave propagation. The electric field of the emitting region of GD near cathode is higher than that of TD near anode because of the cathode fall formation. This observation may apply to designing a DBD process system and to analysis of the process treatment results.

• 한국식품조리과학회지
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• 제24권1호
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• pp.23-30
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• 2008

Sulgidduk samples made with additions of 2, 4, 6, 8, and 10% Houttuynia cordata Thunb. powder, and a control were examined for quality characteristics such as moisture content, water activity, color, gelatinization properties, textural characteristics, and sensory qualities in order to determine the optimal ratio of Houttuynia cordata Thunb. powder in the formulation. The moisture contents among the samples ranged from 41.98% to 44.97%, and increased as the content of Houttuynia cordata Thunb. powder increased. The water activities of the samples were not significantly different. As the Houttuynia cordata Thunb. powder content increased, the redness and yellowness of the samples also increased, but lightness decreased. For the gelatinization properties, the additions of Houttuynia cordata Thunb. powder caused decreases in peak viscosity (P) and holding strength viscosity (H). Furthermore, final viscosity (F), setback, and time to peak viscosity decreased with increasing Houttuynia cordata Thunb. powder content; however, breakdown and temperature to peak viscosity were not significantly different among the samples. Hardness and gumminess decreased with increasing Houttuynia cordata Thunb. powder content, and adhesiveness, cohesiveness, chewiness, and resilience also tended to decrease; however, springiness was not significantly different among the samples. In the consumer acceptance test, as the content of Houttuynia cordata Thunb. powder increased, the scores of all evaluated characteristics decreased; while the characteristic intensity ratings showed the reverse effect, and the 2 and 4% Houttuynia cordata Thunb. powder samples obtained fairly good scores. In conclusion, the results indicate that adding $2{\sim}4%$ Houttuynia cordata Thunb. powder to Sulgidduk is optimal, providing good physiological properties and reasonably high overall consumer acceptability.

• 한국세라믹학회지
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• 제15권4호
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• pp.213-223
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• 1978

The purpsoe of this study was to produce domestic stamping materials; sling mass which could be used as unburned refractory for iron melt'ladle. Batch compositions were based on Belgian Ladelite; mineral compositions were composed of 84 wt% of quartz and 16 wt% of clay, and particle sizes were divided into 12 wt% of 1410/297㎛, 18wt% 297/149㎛, 20wt% of 149/74㎛, 11wt% 74/44㎛ and 39wt% 44㎛ under. The effect of variable batch compositions were also investigated such as substitution of pyrophylite or industrial grade alumina for quartz and of zircon for portion of quartz and clay, increase of clay and addition on sericite. Samples were pressed at 100kg/㎠ with 7.4wt% of water or 7.4wt% of 4 wt% PVA solution. Dried and Fired properties of samples such as linear shrinkage, apparent porosity, modulus of rupture, refractoriness and corrosion resistance to blast furnace slag were investigated. The results are summarized as follows. 1. Dried samples are shrinked, but fired at 700-1400℃ expanded. Samples fired at 700-1000℃ and 1200-1400℃ tended to expand with incresing of firing temperature, but fired at 1000-1200℃ tended to shrink with increase of firing temperature. 2. Apparent porosity of samples fired at 700℃ is increased, but fired at 1200-1400℃ decreased with increasing of firing temperature. 3. Modulus of rupture of samples fired at 700℃ is decreased, but fired at above 700℃ increased with increasment of firing temperature. 4. Dried samples with 7.4 wt% of 4 wt% PVA solution better improve modulus of rupture than with 7.4 wt% of water, but the firing strength of the sampels fired at 700-1000℃ is showed reversely. 5. In quartz-clay system, mineral phases of samples fired at above 1200℃ are consisted of α-quartz, α-cristobalite and mullite. Respectively as firing temperature was rising up, intensity of α-cristobalite and mullite is in creased. 6. Quartz-Kibushi clay system, Kimcheun quartz(substitutuion of portion of industrial grade alumina for quartz) Hampyeung clay system and pyrophyllite-clay system are better in corrosion resistance to blast furnace slag than burned pyrophyllite brick. 7. 84 wt% of pyrophyllite-16wt% of clay system is superior in modulus of rupture and corrosion resistance to blast furnace slag to 84 wt% of quartz-16 wt% of clay system.

• 디지털융복합연구
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• 제15권2호
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• pp.519-525
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• 2017

본 연구는 고령친화 요양산업을 대상으로 정책의 활성화시킬 수 있는 요인과 전략방안들을 도출하는 것이 연구의 목적이다. 분석방법은 DEMATEL기법을 통해 주요 요인들 간의 인과성을 분석하였다. 이는 고령친화 요양산업을 구성하는 활성화 요인 및 그 요인 간의 관련이 복잡 불명확한 것을 정책강화의 우선순위 도출을 통해 보다 명확하게 확인하고자 하였다. 분석결과 종합강도가 가장 높게 나타난 활성화 요인으로는 식사서비스(22.095)가 가장 종합강도가 높은 것으로 분석되었다. 그리고 다음으로 건강증진시설(19.97), 건강관리(17.726) 등의 순으로 높게 나타났다. 가장 낮은 요인은 스포츠(15.896)이다. 따라서, 이러한 요인의 개선 및 증진을 위해서 시설요양서비스, 재가요양서비스, 예방지원서비스와 밀접한 연관성을 가지고 지속적인 정책방안을 모색하여야 할 것이다.

• 폴리머
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• 제28권3호
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• pp.225-231
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• 2004

폴리 카보네이트와 스티렌-아크릴로니트릴 공중합체, 그리고 이들의 혼합물이 혼합기에서 용융 가공되는 동안 고강도 초음파를 조사하였다. 순수한 고분자의 경우에 용융상태에서 가해진 초음파 에너지에 의하여 용융점도가 감소되었으며, 혼합물에서는 분산상의 크기가 감소하는 것으로 확인되었다. 초음파 조사에 따른 성분 고분자의 용융점도 저하는 가공 중에 거대 라디칼이 생성된 것과 관련이 있으며, 이들의 상호 결합으로 말미암아 폴리 카보네이트/스티렌-아크릴로니트릴 혼합물의 상용화가 진행됨을 알 수 있었다. 전체적인 상용화의 효과는 혼합물의 형태학과 기계적 성질을 측정함으로 평가하였다. 총 조사 시간 5분 중에서 약 3분을 전후하여 분산상의 크기가 현저하게 감소하였고 혼합이 끝난 시료를 20$0^{\circ}C$에서 약 10분간 방치한 후의 형태학은 초음파로 처리된 경우에 매우 안정한 상 구조를 유지하였다. 아울러 파단 신율과 인장강도와 같은 기계적 성질이 현저하게 향상되는 결과를 바탕으로, 고강도 초음파를 이용한 용융 혼합은 별도의 상용화제의 투입 없이 비상용계 고분자 혼합물을 상용화할 수 있는 효과적인 방법으로 판단되었다.

• 한국정밀공학회지
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• 제28권12호
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• pp.1425-1433
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• 2011

We investigated an early rehabilitation training system that increase the intensity of patient rehabilitation training to shorten the time it takes for patients to progress to a secondary rehabilitation training stage by allowing patients incapable of self-ambulation. It consisted of tilting bed, unstable platform using strong springs and training program for lower limb rehabilitation. We performed experimental study on the muscular activities of tibialis anterior(TA), soleus(SO), gastrocnemius(GA) in the lower extremities during training of straight line, circle, quardrangle pattern during tilting angle of $30^{\circ}$, $60^{\circ}$. The muscle activities were higher during tilting angle of $30^{\circ}$ than $60^{\circ}$. In straight line pattern, the muscle activities were higher by SO, GA and TA during medio-lateral direction, however, by TA, SO and GA during anterio-posterior direction. In circle and quardrangle pattern, the muscle activities were higher by TA, SO and GA during clockwise and counterclockwise direction. The results indicate that the early rehabilitation training system could be applied to improve the lower extremity muscular strength for elderly and patients, especially, stroke.

• 대한금속재료학회지
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• 제50권5호
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• pp.401-406
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• 2012

When viewed using a magnetic resonance imaging (MRI) system, invasive materials inside the human body, in many cases, severely distort the MR image of human tissues. The degree of the MR image distortion increases in proportion not only to the difference in the susceptibility between the invasive material and the human tissue, but also to the intensity of the magnetic field induced by the MRI system. In this study, by blending paramagnetic Ti particles with diamagnetic graphite, we synthesized $Ti_{100-x}C_x$ composites that can reduce the artifact in the MR image under the high-strength magnetic field. Of the developed composites, $Ti_{70}C_{30}$ showed the magnetic susceptibility of ${\chi}=67.6{\times}10^{-6}$, which corresponds to 30% of those of commercially available Ti alloys, the lowest reported in the literature. The level of the MR image distortion in the vicinity of the $Ti_{70}C_{30}$ composite insert was nearly negligible even under the high magnetic field of 4.7 T. In this paper, we reported on a methodology of designing new structural materials for bio-applications, their synthesis, experimental confirmation and measurement of MR images.

• Geomechanics and Engineering
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• 제1권4호
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• pp.275-289
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• 2009

Electroosmosis (EO) is the movement of water in a porous medium under the influence of a direct current (dc). In past decades, electro-osmosis has been successfully employed in many soil improvement and other geotechnical engineering projects. Metal electrodes, such as steel, copper and aluminum have been used traditionally to conduct current. The shortcoming of these electrodes is that they corrode easily during an EO treatment, which results in reduced effectiveness and environmental concerns. More recently, conductive polymers are developed to replace metal electrodes in EO treatment. Electrical vertical drainages (EVDs) are one of these products under trial. The goal of this study is to assess the performance of EVDs for soil improvement and to further understand the scientific principle of the EO process, including the voltage drop at the soil-EVD interface, electrical current density, polarity reversal, and changes in soil physico-chemical properties generated by electroosmosis. It is found from the study that after 19 days of EO treatment with a constant applied dc electric field intensity of 133 V/m, the soil's moisture content decreased by 28%, the shear strength and pre-consolidation pressure increased more than 400%. It is also found that the current density required triggering the water flow in the soil tested, the Korean Yulchon marine clay, is 0.7 $A/m^2$. The project demonstrates that EVDs can serve as both electrodes and drains for soil improvement in short term. However, the EVDs, as tested, are not suitable for polarity reversal in EO treatment and their service life is limited to only 15 days.

• Nuclear Engineering and Technology
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• 제52권5호
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• pp.897-907
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• 2020

The flow characteristics of reactor fuel assembly always intrigue the designers and the experimentalists among the myriad phenomena that occur simultaneously in a nuclear core. In this work, the visual experimental method has been developed on the basis of refraction index matching (RIM) and particle image velocimetry (PIV) techniques to investigate the detailed flow characteristics in China fast reactor fuel subassembly. A 7-rod bundle of simulated fuel subassembly was fabricated for fine examination of flow characteristics in different subchannels. The experiments were performed at condition of Re=6500 (axial bulk velocity 1.6 m/s) and the fluid medium was maintained at 30℃ and 1.0 bar during operation. As for results, axial and lateral flow features were observed. It is shown that the spiral wire has an inhibitory effect on axial flow and significant intensity of lateral flow mixing effect is induced by the wire. The root mean square (RMS) of lateral velocity fluctuation was acquired after data processing, which indicates the strong turbulence characteristics in different flow subchannels.

• Physical Therapy Rehabilitation Science
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• 제10권4호
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• pp.421-429
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• 2021

Objective: The purpose of this study was to examine the effect of personalized complex aerobic training programs using wearable device on cardiovascular and respiratory functions in community based female elderly. Design: One group pre-post intervention study. Methods: Twenty-one older female participants lived in 'D' city were included. The personalized complex aerobic training program using wearable devices was applied to all participants for 4 weeks, 3 times a week, 30 minutes for per session. The participants' blood pressure, heart rate, oxygen saturation, respiration rate, submaximal exercise stress test, pulmonary function test and respiratory muscle strength test were evaluated before and after the complex training program. Results: After intervention, resting diastolic blood pressure, resting systolic blood pressure and the systolic blood pressure after submaximal exercise stress test were significantly decreased over time (p<0.05), and the submaximal exercise stress test duration were significantly increased over time (p<0.05). The maximal inspiratory pressure (MIP) was significantly increased compare to before the intervention (p<0.05). Conclusions: This study showed that personalized complex training program using wearable device can provide personalized exercise intensity according to cardiopulmonary function that give feedback, and these interventions have a significant effect on improving the cardiovascular and respiratory system functions of the female elderly in the community dwelling.