• Title/Summary/Keyword: specific rotation

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Theory and technology of growing striation-free crystals

  • Scheel, Hans J.
    • Journal of the Korean Crystal Growth and Crystal Technology
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    • v.14 no.4
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    • pp.174-186
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    • 2004
  • Striations are growth-induced inhomogeneities which hamper the applications of solid-solution crystals and of doped crystals in numerous technologies. Thus the optimized performance of solid solutions often can not be exploited. The inhomogeneity problem can be solved in specific cases by achieving a distribution coefficient one in growth from melts and from solutions. Macrostep-induced striations can be suppressed by controlling the growth mode, by achieving growth on facets thereby preventing step bunching. Thermal striations are commonly assumed to be caused by convective instabilities so that reduced convection by microgravity or by damping magnetic fields was and is widely attempted to reduce such inhomogeneities. Here it will be shown that temperature fluctuations at the growth interface cause striations, and that hydrodynamic fluctuations in a quasi-isothermal growth system do not cause striations. The theoretically derived conditions were experimentally established and allowed the growth of striation-free crystals of $KTa_{1-x}Nb_xO_3$"KTN" solid solutions. Hydrodynamic variations from the accelerated crucible rotation technique ACRT did not cause striations as long as the temperature was controlled within $0.03^{\circ}$ at $1200^{\circ}C$ growth temperature. Alternative approaches to solve or reduce the segregation and striation problems in growth from melts and from solutions are discussed as well.

Factor XI deficiency and orthognathic surgery: a case report on anesthesia management

  • Lee, Soo Eon;Choi, Yoon Ji;Chi, Seong-In;Kim, Hyun-Jeong;Seo, Kwang-Suk
    • Journal of Dental Anesthesia and Pain Medicine
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    • v.15 no.1
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    • pp.25-29
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    • 2015
  • Factor XI deficiency (Hemophilia C) is a very rare autosomal recessive bleeding disorder. Patients with factor XI deficiency do not typically show any spontaneous bleeding or specific symptoms. Sometimes those who have this disorder are identified during special situations such as trauma or surgery. Orthognathic surgery is particularly associated with a high bleeding risk. Therefore, great care must be taken when treating patients with bleeding disorders such as factor XI deficiency. There are a few reports that address the management of patients with bleeding disorders during orthognathic surgery. The current report describes a patient with factor XI deficiency who underwent Le Fort I osteotomy together with bilateral sagittal split osteotomy. The patient's condition was assessed using both rotation thromboelastometry ($ROTEM^{TM}$) and noninvasive measurements of total hemoglobin (SpHb) using Masimo Radical 7 (Masimo Co. CA, USA).

An exosolar planetary system N-body simulator II

  • Hong, ChaeLin;van Putten, Maurice
    • The Bulletin of The Korean Astronomical Society
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    • v.43 no.1
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    • pp.46.3-47
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    • 2018
  • We present a general N-body exasolar system simulator in anticipation of upcoming searches for exoplanets and even exomoons by next generation telescopes such as James Webb Space Telescope. For habitable zones, traditionally defined by temperature, we here address the essential problem of dynamical stability of planetary orbits. Illustrative examples are presented on P-type orbits in stellar binary systems, that should be fairly common as in Kepler 16b. Specific attention is paid to reduced orbital lifetimes of exoplanets in the habitable zone by the stellar binary, that is propoesed by Maurice van Putten (2017). Especially, we focused on a classic work of complex three-body problem that is well known by Dvorak(1986). We charge his elliptic restricted three-body problem to extend unrestricted three-body problem to look into dynamical motions in view of circumbinary planet, furthermore, we suggest that opposite angular orientation of the planet is relative to the stability of orbits. In here, counter-rotation case is relatively more faster than co-rotation case for being stable. As a result, we find that various initial conditions and thresholds to approach dynamical stability and unstability with unexpectable isolated islands over enormous parameter space. Even, superkeplerian effect of binary is important to habitability of the exoplanet and we can verify that superfaster binary doesn't effect on th planet and increases survivality of planet around the binary.

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Researches on Populus in Korea for Various Purposes

  • Kim, Chul-Woo;Cha, Du-Song;Choi, Yong-Eui;Koo, Yeong-Bon;Choi, Wan-Yong;Oh, Jae-Heon;Yi, Jae-Seon
    • Journal of Korean Society of Forest Science
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    • v.98 no.5
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    • pp.513-523
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    • 2009
  • Many species, cultivars, and hybrids in Populus have been introduced and developed by the scientists of Department of Forest Genetic Resources, Korea Forest Research Institute in Korea. P. alba ${\times}$ glandulosa, P. euramericana, P. nigra ${\times}$ maximowiczii, P. koreana ${\times}$ P. nigra var. italica, and P. davidiana have been studied from many aspects, i.e., genetics, breeding, physiology, propagation, silviculture, biomass production, biotechnology and phytoremediation. These precedent results will provide a sound basis for a newly-arising research on short-rotation coppice as one of renewable resources and phytoremediation plants. It was found that there were many promising varieties and clones for these purposes. However, minute analysis on specific gravity and caloric values for those plants should be followed under several silvicultural and rotational systems.

Study on the Development and Verification of Dry Manufacturing Technology for improving Quality of Recycled Fine Aggregate (순환잔골재 품질개선을 위한 건식생산기술의 개발 및 검증에 관한 연구)

  • Na, Chul-Sung;Choi, Hyeong-Gil;Kim, Young-Duck;Kwon, Soo-Kil;Kim, Gyu-Yong;Kim, Moo-Han
    • Proceedings of the Korea Concrete Institute Conference
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    • 2008.04a
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    • pp.469-472
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    • 2008
  • As recycled fine aggregate manufacturing technology with exceeding in economical efficiency, reduction efficiency of environmental load and quality improvement effect of recycled fine aggregate, it is to develop dry manufacturing system composed specific gravity separator of high-speed rotation impact type and centrifugal Force Powder Collector, etc. in this study. And it is to verify performance with evaluating quality of recycled fine aggregate. In consequence, it is identify that performance improvement effect of recycled fine aggregate by crushing recycled fine aggregate according to high-speed rotation impact, separating and collecting powder and minuteness dust according to centrifugal Force and mass defect, separating and reclaiming minuteness sand to mass defect.

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Comparison Among Shoulder Diagonal Pattern of Exercises Considering Phase of Contraction Based on Muscle Activity (상지의 대각선 운동형태와 수축형태에 따른 근활성도 비교연구)

  • Soo-Han Kim;Se-Yeon Park
    • PNF and Movement
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    • v.22 no.1
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    • pp.151-158
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    • 2024
  • Purpose: The present study investigated how variations in diagonal exercises affect shoulder muscle activity, examining changes in neuromuscular activation during scapular and shoulder diagonal patterns of exercises. Furthermore, we explored whether the exercise phase affects muscle activation. Methods: Sixteen asymptomatic male participants were recruited. Four diagonal pattern exercises (scapular anterior elevation, posterior elevation, flexion-adduction-external rotation, flexion, abduction-external rotation), and two exercise phases (concentric and eccentric) were administered. Surface electromyography data were collected. Results: Upper trapezius activity was significantly higher during the concentric phase of scapular posterior elevation exercises compared with the others (p<0.05). The serratus anterior, anterior deltoid, and infraspinatus activities were significantly higher during shoulder diagonal pattern exercises compared with the scapular diagonal pattern exercises (p<0.05). Except for the lower trapezius, muscular activities during the concentric phase were significantly greater compared with the eccentric phase (p<0.05). Conclusion: The current study suggests that the diagonal pattern of exercise may contribute to selective strengthening of the shoulder complex muscles and that the form of exercise should be tailored to the subject. It also suggests that diagonal exercises with concentric contractions tend to be more beneficial than eccentric contractions for overall muscle recruitment, but the effects vary for specific diagonal patterns.

Analysis of Cis- Trans Photoisomerization Mechanism of Rhodopsin Based on the Tertiary Structure of Rhodopsin

  • Yamada, Atsushi;Yamato, Takahisa;Kakitani, Toshiaki;Yamamoto, Shigeyoshi
    • Journal of Photoscience
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    • v.9 no.2
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    • pp.51-54
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    • 2002
  • We propose a novel mechanism (Twist Sharing Mechanism) for the cis-trans photoisomerization of rhodopsin, based on the molecular dynamics (MD) simulation study. New things devised in our simulations are (1) the adoption of Mt. Fuji potentials in the excited state for twisting of the three bonds C9=C10, C11=C12 and C13=14 which are modeled using the detailed ab initio quantum chemical calculations and (2) to use the rhodopsin structure which was resolved recently by the X-ray crystallographic study. As a result, we found the followings: Due to the intramolecular steric hindrance between 20-methyl and 10-H in the retinal chromophore, the C12-C13 and C10-C11 bonds are considerably twisted counterclockwise in rhodopsin, allowing only counterclockwise rotation of the C11 =C12 in the excited state. The movement of 19-methyl in rhodopsin is blocked by the surrounding three amino acids, Thr 118, Met 207 and Tyr 268, prohibiting the rotation of C9=C10. As a result only all-trans form of the chromophore is obtainable as a photoproduct. At the 90$^{\circ}$ twisting of C11=C12 in the course of photoisomerization, twisting energies of the other bonds amount to about 20 kcal/mol. If the transition state for the thermal isomerization is assumed to be similar to this structure, the activation energy for the thermal isomerization around C11=C12'in rhodopsin is elevated by about 20 kcal/mol and the thermal isomerization rate is decelerated by 10$\^$-14/ times than that of the retinal chromophore in solution, protecting photosignal from the thermal noise.

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Local and Global Navigation Maps for Safe UAV Flight (드론의 안전비행을 위한 국부 및 전역지도 인터페이스)

  • Yu, Sanghyeong;Jeon, Jongwoo;Cho, Kwangsu
    • The Journal of Korea Robotics Society
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    • v.13 no.2
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    • pp.113-120
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    • 2018
  • To fly a drone or unmanned aerial vechicle(UAV) safely, its pilot needs to maintain high situation awareness of its flight space. One of the important ways to improve the flight space awareness is to integrate both the global and the local navigation map a drone provides. However, the drone pilot often has to use the inconsistent reference frames or perspectives between the two maps. In specific, the global navigation map tends to display space information in the third-person perspective, whereas the local map tends to use the first-person perspective through the drone camera. This inconsistent perspective problem makes the pilot use mental rotation to align the different perspectives. In addition, integrating different dimensionalities (2D vs. 3D) of the two maps may aggravate the pilot's cognitive load of mental rotation. Therefore, this study aims to investigate the relation between perspective difference ($0^{\circ}$, $90^{\circ}$, $180^{\circ}$, $270^{\circ}$) and the map dimensionality matches (3D-3D vs. 3D-2D) to improve the way of integrating the two maps. The results show that the pilot's flight space awareness improves when the perspective differences are smaller and also when the dimensionalities between the two maps are matched.

Correlations between the Muscle Thickness of the Transverse Abdominis and the Multifidus Muscle with Spinal Alignment in College Students (대학생의 배가로근과 뭇갈래근 두께와 척추정렬간의 상관관계)

  • Lim, Jae-Heon
    • PNF and Movement
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    • v.12 no.4
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    • pp.243-248
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    • 2014
  • Purpose: The transverse abdominis and themultifidus muscle are located in the core. They surround one's trunk and help in body stabilization. Specifically, they control spine articulation to maintain posture and balance. Therefore, weakened deep muscle in the trunk may cause spinal malalignment. This study aims to compare the correlation between the thickness of the transverse abdominis and the multifidus muscle and the spine alignment among college students in their 20s. Methods: This study measured the thickness of the transverse abdominis and the multifidus muscle of 42 healthy college students in their 20s using ultrasonic waves. The thickness of the muscle was measured for the length of the cross-section except for fascia. The thickness of the left and right muscles was measured, and the mean value was calculated. As the thickness of the transverse abdominis can increase because of pressure during exhalation, it was measured at the last moment of exhalation. Spinal alignment was measured by the kyphosis angle, lordosis angle, pelvic tilt, trunk inclination, lateral deviation, trunk imbalance, and surface rotation using Formetric III, which is a three-dimensional imaging equipment. They were measured for three times, and the mean values were calculated. The general characteristics of the subjects were analyzed using descriptive statistics. The correlations between each factor were analyzed using Pearson's correlation analysis. Results: The transverse abdominis showed asignificant correlation with trunk inclination (p<.05). The multifidus muscle showed a significant positive correlation with pelvic tilt and a negative correlation with surface rotation (p<.05). Conclusion: The thickness of transverse abdominis and the multifidus muscle appears to influence spinal alignment. Specifically, the multifidus muscle, which plays an important role on the sagittal plane, influences surface rotation, thus making it an important muscle for scoliosis patients. Therefore, a strengthening training program for the transverse abdominis and the multifidus muscle is necessary according to specific purposes among adults with spinal malalignment.

Development of a foaling alarm system using an accelerometer

  • Youngwook, Jung;Honghee, Chang;Minjung, Yoon
    • Journal of Animal Science and Technology
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    • v.64 no.6
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    • pp.1237-1244
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    • 2022
  • Horse breeders suffer massive economic losses due to dystocia, abortion, and stillbirths. In Thoroughbred mares, breeders often miss the foaling process because approximately 86% of the foaling events occur from 19:00 to 7:00; consequently, breeders cannot assist mares experiencing dystocia. To solve this problem, various foaling alarm systems have been developed. However, there is a need to develop a new system to overcome the shortcomings of the existing devices and improve their accuracy. To this end, the present study aimed to (1) develop a novel foaling alarm system and (2) compare its accuracy with that of the existing FoalertTM system. Specifically, eighteen Thoroughbred mares (11.9 ± 4.0 years old) were included. An accelerometer was used to analyze specific foaling behaviors. Behavioral data were transmitted to a data server every second. Depending on the acceleration value, behaviors were automatically classified by the server as categorized behaviors 1 (behaviors without change in body rotation), 2 (behaviors with sudden change in body rotation, such as rolling over), and 3 (behaviors with long-term change in body rotation, such as lying down laterally). The system was designed to alarm when the duration of categorized behaviors 2 and 3 was 12.9% and that of categorized behavior 3 was 1% during 10 min. The system measured the duration of each categorized behavior every 10 min and transmitted an alarm to the breeders when foaling was detected. To confirm its accuracy, the foaling detection time of the novel system was compared with that of FoalertTM. The novel foaling alarm system and FoalertTM alarmed foaling onset respectively 32.6 ± 17.9 and 8.6 ± 1.0 min prior to foal discharge, and the foaling detection rate of both systems was 94.4%. Therefore, the novel foaling alarm system equipped with an accelerometer can precisely detect and alert foaling onset.