• 한국정보전자통신기술학회논문지
• /
• 제14권5호
• /
• pp.362-368
• /
• 2021

본 논문에서는 알킬 사슬 길이에 따른 러빙 처리된 불소화 자기 조립 단분자막(fluorinated self-assembled monolayers; FSAM)의 수직 액정 배향 상태를 보고한다. FSAM의 증착을 위해 간단한 공정인 기체-상 방법이 사용되었다. FSAM의 가시광선 영역대 광학 평균 투과율은 77.63%~78.21%로 75.89%의 투과율을 갖는 기존의 폴리이미드막보다 우수하였다. 또한 프리틸트각 측정과 편광현미경 사진을 통해 FSAM의 우수한 수직 배향 특성을 관찰하였다. 접촉각과 FSAM의 표면에너지 측정을 통해 알킬 사슬 길이에 따른 프리틸트각이 증가하는 것을 확인하였다. FSAM의 높은 광학 투과율과 균일한 수직 배향 특성은 FSAM이 액정 배향막으로서의 가능성을 보여주었다.

• 한국운동역학회지
• /
• 제31권3호
• /
• pp.183-188
• /
• 2021

Objective: The purpose of this study was to develop a stretchable joint motion sensor that is based on silver nano-particle. Through this sensor, it can be utilized as an equipment for rehabilitation and analyze joint movement. Method: In this study, precursor solution was created, after that, nozel printer (Musashi, Image master 350PC) was used to print on a circuit board. Sourcemeter (Keithley, Keithley-2450) was used in order to evaluate changes of electric resistance as the sensor stretches. In addition, the sensor was attached on center of a knee joint to 2 male adults, and performed knee flexion-extension in order to evaluate accurate analysis; 3 infrared cameras (100 Hz, Motion Master 100, Visol Inc., Korea) were also used to analyze three dimensional movement. Descriptive statistics were suggested for comparing each accuracy of measurement variables of joint motions with the sensor and 3D motions. Results: The change of electric resistance of the sensor indicated multiple of 30 times from initial value in 50% of elongation and the value of electric resistance were distinctively classified by following 10%, 20%, 30%, 40% of elongation respectively. Through using the sensor and 3D camera to analyze movement variable, it showed a resistance of 99% in a knee joint extension, whereas, it indicated about 80% in flexion phase. Conclusion: In this research, the stretchable joint motion sensor was created based on silver nanoparticle that has high conductivity. If the sensor stretches, the distance between nanoparticles recede which lead gradual disconnection of an electric circuit and to have increment of electric resistance. Through evaluating angle of knee joints with observation of sensor's electric resistance, it showed similar a result and propensity from 3D motion analysis. However, unstable electric resistance of the stretchable sensor was observed when it stretches to maximum length, or went through numerous joint movements. Therefore, the sensor need complement that requires stability when it comes to measuring motions in any condition.

• 방송공학회논문지
• /
• 제24권3호
• /
• pp.452-462
• /
• 2019

차세대 영상시스템의 하나인 디지털홀로그램은 다양한 형태로 생성되고 재생될 수 있고, 디지털홀로그램은 재생을 위한 시스템의 특성에 맞게 생성된다. 다양한 조건으로 생성된 디지털홀로그램이 다양한 재생환경에서 어떠한 특성을 나타내는지에 대한 척도로써 회절효율의 측정을 사용할 수 있다. 본 논문에서는 다양한 조건으로 생성된 컴퓨터생성홀로그램(Computer-generated Hologram, CGH)에 대한 회절효율을 측정하였다. 이를 통해 홀로그램 재생 시 고려해야되는 생성 조건에 대해 논의한다. 위상 방식의 복소 홀로그램을 대상으로 프레넬 조건 하에서 생성된 프린지의 1차 회절 패턴의 강도를 측정함으로써 각 조건들을 비교한다. 본 논문을 통해서 객체 포인트, 복원 거리, 레이저 및 SLM의 종류에 따른 회절효율의 특성에 대한 경향성을 보였다.

• 한국응급구조학회지
• /
• 제23권1호
• /
• pp.61-69
• /
• 2019

Purpose: The study aims to provide basic data to enhance the health of paramedics responsible for patient transport and treatment by analyzing the exposure level of paramedics to electromagnetic waves generated by electric devices used in ambulances. Methods: The study measured electromagnetic waves in ambulances in N region from July to December 2018. ME3030B produced by German Gigahertz Solutions was used to measure these waves and the maximum value was selected by moving it slowly in various directions. Each measurement part was selected and the mean value was calculated by repeatedly measuring at 10-minute intervals three times in total: $1^{st}$, $2^{nd}$, and $3^{rd}$ phase. Results: Among the electrical devices installed in the patient room of the ambulance measured at distances of 1 cm or 30 cm, results showed a high level of electric waves at the inverter ($26.25{\pm}39V/m$) and high level of electromagnetic waves ($564.00{\pm}31.75nT$) at the ozone sterilizer. According to measurements toward the front near the driver's seat, results indicated high levels of electric waves ($3.67{\pm}1.15V/m$) and electromagnetic waves ($450.00{\pm}19.52nT$) at the black box hard drive. Conclusion: Electromagnetic waves within the ambulance were stable and not beyond the range that might impact human health. However, in the case of the black box hard drive ($3.67{\pm}1.15V/m$, $450.00{\pm}19.52nT$) located under the passenger seat, it may have a direct effect on the human body and, thus it is necessary to move it to a storage area further away from the paramedics to minimized the impact.

• 대한치과교정학회지
• /
• 제49권3호
• /
• pp.161-169
• /
• 2019

Objective: To evaluate the effectiveness of the Frog appliance in three dimensions by using cone-beam computed tomography (CBCT) images. Methods: Forty patients (21 boys and 19 girls), averaged 11.7 years old, with an Angle Class II division 1 malocclusion were included in our study. They had either late mixed dentition or early permanent dentition, and the maxillary second molars had not yet erupted. All patients underwent CBCT before and after the treatment for measuring changes in the maxillary first molars, second premolars, central incisors, and profile. Paired-samples t-test was used to compare the mean difference in each variable before treatment and after the first phase of treatment. Results: The maxillary first molars were effectively distalized by 4.25 mm (p < 0.001) and 3.53 mm (p < 0.05) in the dental crown and root apex, respectively. The tipping increased by $2.25^{\circ}$, but the difference was not significant. Moreover the teeth moved buccally by 0.84 mm (p < 0.05) and 2.87 mm (p < 0.01) in the mesiobuccal and distobuccal cusps, respectively, whereas no significant changes occurred in the root apex. Regarding the anchorage parts, the angle of the maxillary central incisor's long axis to the sella-nasion plane increased by $2.76^{\circ}$ (p < 0.05) and the distance from the upper lip to the esthetic plane decreased by 0.52 mm (p = 0.01). Conclusions: The Frog appliance effectively distalized the maxillary molars with an acceptable degree of tipping, distobuccal rotation, and buccal crown torque, with only slight anchorage loss. Furthermore, CBCT image demonstrated that it is a simple and reliable method for three-dimensional analysis.

• 한국식품영양학회지
• /
• 제31권6호
• /
• pp.957-963
• /
• 2018

Deoduk (Codonopsis lanceolata) has a complex chemical composition that includes polyphenols, saponins, amino acids, and other unidentified compounds. The contents of tangshenoside and lobetyolin are considered as standard of quality evaluation of Deoduk. In this study, an ultra-performance liquid chromatography (UPLC) method was developed for the quantitative determination of the two marker constituents, tangshenoside and lobetyolin. The methods for determining the standards of quality were validated by measuring their linearity, specificity, limit of detection (LOD), limit of quantification (LOQ), precision, and accuracy using UPLC. Reversed-phase UPLC analysis was conducted quantitatively to identify individual tangshenoside and lobetyolin in Deoduk extracted with 50% (v/v) aqueous ethanol. We used 21 samples to carry out quantitative analysis of tangshenoside and lobetyolin. Based on their dry weights, the levels of tangshenoside and lobetyolin were 0.36~3.54 mg/g, 0.24~1.29 mg/g, respectively. These results will be valuable as basic data for standardization of Korean Deoduk.

• Physical Therapy Rehabilitation Science
• /
• 제10권2호
• /
• pp.161-166
• /
• 2021

Objective: The purpose of this study was to quantitatively evaluate the Wii Balance Board (WBB)-based jump performance for the elderly and to confirm the difference in jump performance according to age. Design: Cross-sectional study. Methods: 40 young adults (aged 22.5±2.2 years) and 33 elderly (aged 75.1±5.2 years) without orthopedics disease participated in this study. Standing on the WBB then, with the signal "start," jump vertically to the maximum height at which you can jump, land on the force plate after jump and keep it standing on both feet. All subjects were required to practice the jump sufficiently before starting the measurement, each measuring three times, and the mean values were used. A one-minute break was provided between each trial. Evaluators waited within 1meter for every test to prepare for fall. Results: The vertical ground reaction force of elderly and young adults when jumping using WBB showed a significant difference (p<0.05) and demonstrated discriminant validity. Between two groups, there were significant differences in overall jump time (p<0.05), maximum value (p<0.05), minimum value (p<0.05), center of pressure (COP) pathlength (p<0.05), and flight time p<0.05). Conclusions: This study found that performing the vertical jump, the elderly showed longer jump time, lower vertical ground reaction force, COP pathlength and shorter flight phase than healthy young adults using WBB and demonstrated that as a measurement tool, WBB discriminated vertical jump performance between elderly and young adults.

• 한국분말재료학회지
• /
• 제28권4호
• /
• pp.336-341
• /
• 2021

In this study, a nanocrystalline FeNiCrMoMnSiC alloy was fabricated, and its austenite stability, microstructure, and mechanical properties were investigated. A sintered FeNiCrMoMnSiC alloy sample with nanosized crystal was obtained by high-energy ball milling and spark plasma sintering. The sintering behavior was investigated by measuring the displacement according to the temperature of the sintered body. Through microstructural analysis, it was confirmed that a compact sintered body with few pores was produced, and cementite was formed. The stability of the austenite phase in the sintered samples was evaluated by X-ray diffraction analysis and electron backscatter diffraction. Results revealed a measured value of 51.6% and that the alloy had seven times more austenite stability than AISI 4340 wrought steel. The hardness of the sintered alloy was 60.4 HRC, which was up to 2.4 times higher than that of wrought steel.

• 한국분말재료학회지
• /
• 제28권1호
• /
• pp.20-24
• /
• 2021

Ti-based alloys are widely used in biomaterials owing to their excellent biocompatibility. In this study, Ti-Mn-Cu alloys are prepared by high-energy ball milling, magnetic pulsed compaction, and pressureless sintering. The microstructure and microhardness of the Ti-Mn-Cu alloys with variation of the Cu addition and compaction pressure are analyzed. The correlation between the composition, compaction pressure, and density is investigated by measuring the green density and sintered density for samples with different compositions, subjected to various compaction pressures. For all compositions, it is confirmed that the green density increases proportionally as the compaction pressure increases, but the sintered density decreases owing to gas formation from the pyrolysis of TiH2 powders and reduction of oxides on the surface of the starting powders during the sintering process. In addition, an increase in the amount of Cu addition changes the volume fractions of the α-Ti and β-Ti phases, and the microstructure of the alloys with different compositions also changes. It is demonstrated that these changes in the phase volume fraction and microstructure are closely related to the mechanical properties of the Ti-Mn-Cu alloys.

• Animal Bioscience
• /
• 제34권3_spc호
• /
• pp.354-362
• /
• 2021

Broiler chickens grow rapidly, and their nutrient requirements change daily. However, broilers are fed three to five diet phases, meaning nutrients are under or oversupplied throughout production. Increasing diet phases improves production efficiency as there is less time in the production cycle that nutrients are in under or over-supply. Nevertheless, the process of administering four or more diets is costly and often impractical. New technologies are now available to blend feed to match the daily nutrient requirements of broilers. Thus, the aim of this review is to evaluate previous studies measuring the impact of increasing feed phases on nutrient utilisation and growth performance, and review recent studies taking this concept to the extreme; precision nutrition - feeding a new diet for each day of the production cycle. This review will also discuss how modern precision feeding technologies have been utilised and the potential that new technologies may bring to the poultry industry. The development of a precision nutrition regime which targets daily requirements by blending dietary components on farm is anticipated to improve the efficiency of production, reduce production cost and therefore improve sustainability of the industry. There is also potential for precision feeding technology along with precision nutrition strategies to deliver a plethora of other management and economic benefits. These include increased fluidity to cope with sudden environmental or market changes, and the ability to alter diets on a farm by farm level in a large, integrated operation. Thus, the future possibilities and practical implications for such technologies to generate a paradigm shift in feed formulation within the poultry industry to meet the rising demand for animal protein is also discussed.