• Journal of Ceramic Processing Research
• /
• 제13권spc1호
• /
• pp.154-157
• /
• 2012

We present the simultaneous growth of single-walled carbon nanotubes and graphene with the optimal conditions of the synthesizing parameters. The dense and vertically aligned SWNTs having the length of over 100 ㎛ was grown by 2 nm-thick Fe catalytic layer. From 650 ℃, the vertically well-grown SWNTs were obtained by increasing the temperature. The severallayered graphene was synthesized with the gas mixing ratio of 15 : 1(H2 : C2H2) at 650 ℃ and higher temperatures. With these optimal conditions, the vertically well-grown SWNTs and the several-layered graphene were synthesized simultaneously. The presence of SWNTs and the layer of graphene were verified by field emission scanning electron microscopy and high resolution transmission electron microscopy. From the result of this simultaneous synthesizing approach, the possibility of one step growth process of CNTs and grapheme could be verified.

• 한국반도체및디스플레이장비학회:학술대회논문집
• /
• 한국반도체및디스플레이장비학회 2004년도 International Symposium
• /
• pp.1-15
• /
• 2004

o Various microfluidic components including mixromixers and micropumps have been developed for disposable biochip applications. o Single cell capturing, positioning and nanoliter drug injection chip has been demostrated. o Multi-channel, two-dimensional micro-well array has been fabricated and cell capturing and specific reagent injection have been performed.

• Maxillofacial Plastic and Reconstructive Surgery
• /
• 제34권3호
• /
• pp.186-199
• /
• 2012

Purpose: Single implants, of which screw loosening has been observed frequently, presents problems such as fixtures fractures, marginal bone loss, and inflammation of the soft tissue around the implant. However, the single implant is more conservative, cost effective, and predictable compared to the 3 unit bridge with respect to the long-term outcome. This study evaluated the survival rate as well as future methods aimed at increasing the survival rate in single implants in posterior teeth. Methods: Among the implants placed in the Dankook University Dental Hospital department of Oral & Maxillofacial surgery from January 2001 to June 2008, 599 implants placed in the maxillar and mandibular posterior were evaluated retrospectively. Survival rates were investigated according to implant location, cause of tooth loss, gender, age, general disease, fixture diameter and length, surface texture, implant type and shape, presence of bone graft, surgery stage, surgeons, bone quality and opposite teeth. Results: Out of 599 single implants in posterior teeth, 580 implants survived and the survival rate was 96.8%. The difference in survival rate was statistically significant according to the implant location. The survival rate was low (84.2%) in implants exhibiting a wide diameter (${\geq}5.1mm$) and the surface treated by the acid etching group demonstrated a significantly lower survival rate (91.1%). One stage surgical procedure, which implemented a relatively better bone quality survival rate (100%), was higher than the two stage surgical procedure (96.1%). The survival rate of type IV bone quality (75%) was significantly lower than the other bone quality. Conclusion: Single posterior teeth implant treatments should use an improved surface finishing fixture as well as careful and safe procedures when performing implant surgery in the maxilla premolar and molar regions since bone quality is poor.

• 한국정보시스템학회지:정보시스템연구
• /
• 제28권4호
• /
• pp.1-25
• /
• 2019

Purpose The purpose of this study is to investigate cognitive mechanism of goal relations (Single-goal vs. Multiple-goals) and to-do list (Packing vs. Unpacking) and also verify the role of self-efficacy in the perspective of motivation belief. The perspective of cognitive mechanism is related to the effects of how the relations of multitasking environments affects to facilitating relation or conflicting relations. In pursuit of a single goal, judgement of task importance can be facilitated by unpacking effect due to relations of strongly associated project components including to-do list. On the other hands, in pursuit of multiple goals, judgement of task importance can be conflicted due to mutually exclusive relations of multiple goals. Additionally, the cognitive mechanism can be regulated from the role of self-efficacy, which contributes to motivation belief on how much a person is confident in achieving given tasks. In the end this research is to identify self-efficacy as boundary condition in inhibiting the effects of facilitation and conflict. Design/methodology/approach This study conducted Two-way ANOVA (Packing/ Unpacking * Single-goal/ Multiple-goals) to explore the effects of cognitive mechanism on task importance. After that we performed Three-way ANOVA, 2 (To-do list: Packing/ Unpacking) * 2 (Goal relation: Single-goal/ Multiple-goals) * 2 (Self-efficacy: Low self-efficacy/ High self-efficacy) to verify the role of self-efficacy between goal relations and to-do list. Findings In the cognitive mechanism, the task importance is not significantly different between in packed and in unpacked condition in pursuit of a single goal. But multitasking with multiple goals causes goal conflict, which means packed condition indicates significantly higher task importance than unpacked condition. Additionally, for a group with low self-efficacy unpacking leads to conflicting relation, which implies that packed condition is more efficient strategy than packed condition. On the other hands, in pursuit of mulitple goals, either packing or unpacking has no distinctive effects on task importance. However, participants with high self-efficacy are no longer affected by facilitating relation and conflicting relation as well in pursuit of either a single goal or multiple goals as well.

• 한국결정성장학회:학술대회논문집
• /
• 한국결정성장학회 1996년도 The 9th KACG Technical Annual Meeting and the 3rd Korea-Japan EMGS (Electronic Materials Growth Symposium)
• /
• pp.526-526
• /
• 1996

The single crystal of LiTaO3 is well known eletro-optic material as well as the piezoelectric one applied to SAW filter. LiTaO3 has large electro-optic effects, so applied to optical switch, acosto-optic deflector, and optical memory device using photorefractive effects. The crystal growth of SAW-grade LiTaO3 has been studied many aspects, but there is no detail research about optic-grade crystal growth. The conditions of optic-grade LiTaO3 single crystal are as below. The optical transmittance must be over 75%, and axial and radial concentratiom uniformity below 1%. The variation of Curie temperature depending on Li/Ta ratio must be also below 2$^{\circ}C$ and no internal no internal cracks and defects. Because of the limitation of crystal quality, the growing of optic-grade LiTaO3 single crystal is very difficult compared with the growing of SAW-grade. In this research, upper conditions of optic-grade single crystal was investigated after growing of 1 inch diameter and 1.5 inch length LiTaO3 single crystal having no internal cracks and defects using Czochralski method. Curie temperature was determined with DSC and measuring capacitance and lattice parameter was calculated about the grown crystal and ceramic powder samples of various Li/Ta ratio. The result of Tc variation was below 1.2$^{\circ}C$ all over the grown crystal, so it is confirmed that LiTaO3 was grown under congruent melting composition having optical homogeniety. Also, the optical transmittance was about 78%, which was sufficient for optical device.

• 대한전자공학회:학술대회논문집
• /
• 대한전자공학회 2002년도 하계종합학술대회 논문집(2)
• /
• pp.21-24
• /
• 2002

A sensor array (35mm'! in diaphragm dimension) of 12 sensing elements with different operating temperatures was optimized with respect to thermal operation. This sensor array with single heater on a glass diaphragm over back-etched silicon bulk realizes a novel concept of a sensor array: an way of sensor elements operated at different temperatures can yield more information than single measurement. The proposed micro sensor array could provide well-integrated way structure because it has only single heater at the center of the diaphragm and used the various sensing properties of two kinds of metal oxide layers with various operating temperatures.

• 한국섬유공학회:학술대회논문집
• /
• 한국섬유공학회 2003년도 가을 학술발표회 논문집
• /
• pp.291-292
• /
• 2003

Although the tensile strength of textile materials are determined by that of their components, it is well known that the tensile strength of fiber bundles and yams is not accurately predicted from that of single-fibers by simple averaging methods or mathematical calculations, because of variations in their strength. Therefore, there have been attempts to interpret the bundle strength from that of its elements by the stochastical approach. (omitted)

• Nonlinear Functional Analysis and Applications
• /
• 제27권4호
• /
• pp.731-742
• /
• 2022

In this paper, we present a new mixed type iterative process for approximating the common fixed points of single-valued nonexpansive mapping and multi-valued nonexpansive mapping in a CAT(0) space. We demonstrate strong and weak convergence theorems for the new iterative process in CAT(0) spaces, as well as numerical results to support our theorem.

• 한국생산제조학회지
• /
• 제25권6호
• /
• pp.452-457
• /
• 2016

Single screw compressors are widely used in the fields of air/gas compression, refrigeration, and chemical fluid transportation systems. A single-screw compressor is composed of a screw rotor and two gate rotors located at both sides. This simple construction enables low rotational speed of the rotor, efficient compression with low noise, low vibration, and long bearing life. Despite these merits, the design method of single-screw compressors is not well known. To accelerate the industrial application of single-screw compressors, a design method using coordinate transformation is presented in this paper, and a tool trajectory is established for machining. Finally, the screw rotor, which is machined using the proposed method, is presented.

• JSTS:Journal of Semiconductor Technology and Science
• /
• 제2권1호
• /
• pp.7-18
• /
• 2002

Single-ended differential RF circuit topologies fully utilizing complementary characteristics of both NMOS and PMOS are proposed, which have inherent advantage of both single-ended and differential circuits. Using this concept, we propose a CCPP (Complementary CMOS parallel push-pull) amplifier which has single-ended input/output with differential amplifying characteristics, leading to more than 30 dB improvement on $IIP_2$. In addition, complementary resistive mixer is also proposed, which provides not only differential IF outputs from single-ended RF input, but much better linearity as well as isolation characteristics. Experimental results using $0.35{\;}\mu\textrm{m}$ CMOS process show that, compared with conventional NMOS resistive mixer, the proposed mixer shows 15 dB better LO-to-IF isolation, 4.6 dB better $IIP_2$, and 4.5 dB better $IIP_3$performances.