• Title/Summary/Keyword: sun position

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A Study on AC/DC Power Converter of Energy Harvesting for Considered to Solar Position Tracking Control (태양광 위치 추적 제어를 고려한 에너지 Harvesting AC/DC 전력 변환기 구동에 관한 연구)

  • Na, Seung-Kwon;Ku, Gi-Jun
    • Journal of Advanced Navigation Technology
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    • v.18 no.1
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    • pp.56-66
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    • 2014
  • In this paper, the solar cell need the characteristic interpreting because the solar cell changes greatly according to the isolation, temperature and load in the photovoltaic development. Moreover, to get many energy in photovoltaic development need the position tracking of the sun according to the environment change and it is necessary to control the output of solar cells up to the time. Simulation and composed microprocessor and sensor chip an power conversion system with boost converter to experiment results are performed to prove the analysis of the converter operation, and to show the possibility of energy harvesting and photovoltaic development need the position tracking small capacitance, the boost rate of boost converter was similar to 167 percent.

A Study on the Relationship of Power and Empowerment, Self-Efficacy of Dental Hygienists (치과위생사가 지각하는 파워와 임파워먼트, 자기효능감과의 관계 연구)

  • Lee, Sun-Mi
    • Journal of Korean society of Dental Hygiene
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    • v.5 no.1
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    • pp.77-88
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    • 2005
  • The purpose of this study was to investigate the relationship of power and empowerment, self-efficacy of dental hygienists. Date were obtained from 203 dental hygienists who were working at dental clinics, hospitals located in Seoul. The results were analyzed with spsswin 12.0 and the conclusion is as follows: 1. The level of dental hygienists formal power was 3.19, informal power was 3.41, empowerment was 3.12, self-efficacy was 3.67. 2. Formal power showed significant a positive correlation with informal power and informal power showed significant a positive correlation with empowerment 3. According to the position, there were significant differences in formal power(pE0.05). 4. According to the working place, age, experienced-years, position, marriage and turnover experience there were significant differences in informal power(pE0.05). S. According to the working place, position, and marriage there were significant differences in empowerment(pE0.05). 6. According to the age, experienced-years, position, marriage and turnover experience there were significant differences in self-efficacy(pE0.05). 7. Informal power and information structure accounted significantly for the self-efficacy.

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Phrase positional effects on F0 peak timing in Tokyo Japanese

  • Cho, Hye-Sun
    • Phonetics and Speech Sciences
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    • v.3 no.3
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    • pp.69-75
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    • 2011
  • This paper investigates phrase positional effects on the timing of F0 (pitch) peaks in Tokyo Japanese disyllabic words with varying accent type (HL or LH) and phrase position (final or non final). The F0 peak timing was normalized by the total word duration ('normalized H timing'). The normalized H timing was significantly affected by accent type and phrase position. The H timing was later in the LH accent type than in the HL accent type, and in non final positions than in final positions. In addition, to examine the validity of the quantitative results, different models of phrase position effects were compared by measuring H timing in two approaches: normalization versus relative distance measures. For the normalization measures, the H timing was measured as the time of the F0 peak divided by the total word duration or by the duration of the tone bearing syllable. For the relative distance measures, the H timing was measured as the distance in milliseconds from the end of the word or from the end of the associated syllable. The best model was the normalization by the total word duration, rather than by the duration of the tone bearing syllable. This means that phrase positional effects on the timing of F0 peaks in Japanese disyllabic words are best modeled in terms of proportion of the total word duration.

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Influence of Slashpipe Exercise on Symmetrical Contraction of Trunk Muscle in Normal Adults

  • Choi, Young In;Kim, Jung Sun;Kim, Shin Young
    • The Journal of Korean Physical Therapy
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    • v.31 no.5
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    • pp.298-303
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    • 2019
  • Purpose: This study examined the effects of slashpipe exercise on reducing the thickness of the left and right external oblique, internal oblique, transverse abdominis, erector spinae, and multifidus muscles. Methods: A total of 29 healthy adult men and women were included in the study. They performed trunk flexion in the supine position and trunk extension in the prone position with a slashpipe and weight bar. The external oblique, internal oblique, and transverse abdominis muscles were measured in the supine position, while the erector spinae and multifidus muscles were measured in the prone position. The data were analyzed using the SPSS ver 21.0 statistical program. The difference in thickness between the right and left sides of the trunk muscle was analyzed by repeated measures analysis. The statistical significance level was set to p<0.05. Results: The results showed that the slashpipe exercise reduced significantly the difference in thickness of the oblique internus and erector spinae muscles compared to the weight bar exercise. Conclusion: The chaotic fluidity of the fluid filled inside the slashpipe could be used as sensory feedback information on body mal-alignment, which would have positively affected the symmetrical contraction of the trunk muscles as a trigger for self-correction. Therefore, it will have a useful effect not only on the health of the general public, but also on low back patients and athletes with muscle asymmetry.

Characterization of CYP125A13, the First Steroid C-27 Monooxygenase from Streptomyces peucetius ATCC27952

  • Rimal, Hemraj;Subedi, Pradeep;Kim, Ki -Hwa;Park, Hyun;Lee, Jun Hyuck;Oh, Tae-Jin
    • Journal of Microbiology and Biotechnology
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    • v.30 no.11
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    • pp.1750-1759
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    • 2020
  • The characterization of cytochrome P450 CYP125A13 from Streptomyces peucetius was conducted using cholesterol as the sole substrate. The in vitro enzymatic assay utilizing putidaredoxin and putidaredoxin reductase from Pseudomonas putida revealed that CYP125A13 bound cholesterol and hydroxylated it. The calculated KD value, catalytic conversion rates, and Km value were 56.92 ± 11.28 μM, 1.95 nmol min-1 nmol-1, and 11.3 ± 2.8 μM, respectively. Gas chromatography-mass spectrometry (GC-MS) analysis showed that carbon 27 of the cholesterol side-chain was hydroxylated, characterizing CYP125A13 as steroid C27-hydroxylase. The homology modeling and docking results also revealed the binding of cholesterol to the active site, facilitated by the hydrophobic amino acids and position of the C27-methyl group near heme. This orientation was favorable for the hydroxylation of the C27-methyl group, supporting the in vitro analysis. This was the first reported case of the hydroxylation of cholesterol at the C-27 position by Streptomyces P450. This study also established the catalytic function of CYP125A13 and provides a solid basis for further studies related to the catabolic potential of Streptomyces species.

A Study on Focus Position Control of Reflector Using Fuzzy Controller (퍼지제어기를 이용한 반사경의 초점 위치제어에 관한 연구)

  • Jeong, Hoi-Seong;Kim, Jun-Su;Kim, Hye-Ran;Kim, Gwan-Hyung;Lee, Hyung-Ki
    • Journal of the Korean Institute of Intelligent Systems
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    • v.21 no.5
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    • pp.645-652
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    • 2011
  • The present study investigated the tracking system of a reflector to trace the movement of sun. The system was designed to minimize the error between the vertical vector of reflector and the position of sun. The proposed system was able to collect the sun lights at a point as a useful source of light energy and transmit the collected light to a remote area through optical fibers. Also the study successfully solved the controller design problem due to the complexity of modeling of the sun tracking system using a fuzzy logic controller which mimics human reasoning.

Analysis of Heliostat Sun Tracking Error due to the Mirror Installation and Drive Mechanism Induced Errors (Heliostat 반사거울 설치 및 구동기구 유발 오차에 의한 태양추적오차의 해석)

  • Park, Young-Chil
    • Journal of the Korean Solar Energy Society
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    • v.29 no.3
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    • pp.1-11
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    • 2009
  • Heliostat sun tracking accuracy could be the most important requirement in solar thermal power plant, since it determines the overall efficiency of power plant. This study presents the effect of geometrical errors on the heliostat sun tracking performance. The geometrical errors considered here are the mirror canting error, encoder reference error, heliostat position error. pivot offset and tilt error, gear backlash and mass unbalanced effect error. We first investigate the effect of each individual geometrical error on the sun tracking accuracy. Then, the sun tracking error caused by the combination of individual geometrical error is computed and analyzed. The results obtained using the solar ray tracing technique shows that the sun tracking error due to the geometrical error is varying almost randomly. It also shows that the mirror canting error is the most significant error source, while the encoder reference error and gear backlash are second and the third dominant source of errors.

Arthroscopic Approach of the Elbow

  • Kim Seung-Ki
    • The Academic Congress of Korean Shoulder and Elbow Society
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    • 2003.11a
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    • pp.61-63
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    • 2003
  • - Injury to the neurovascular structures can be minimized - Incising the skin only - Using blunt dissection and blunt trocars - Distending the joint - Placing the anterior portals in a more proximal position - With more innovation in instrument and techni

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Cas A as a supernova remnant - The Supernova of the 16th Century

  • Chu, Sun-Il
    • Journal of The Korean Astronomical Society
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    • v.6 no.1
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    • pp.1-8
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    • 1973
  • Presumable explosion time of Cas A has been listed from Dec. 6, 1592 to Mar. 5, 1593 in ancinet Korean observational records. It may have been overlooked, due to other supernova(Cassiopeia Nova) which appeared at that time near its original position of Cas A.

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Cone-beam computed tomographic evaluation of the temporomandibular joint and dental characteristics of patients with Class II subdivision malocclusion and asymmetry

  • Huang, Mingna;Hu, Yun;Yu, Jinfeng;Sun, Jicheng;Ming, Ye;Zheng, Leilei
    • The korean journal of orthodontics
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    • v.47 no.5
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    • pp.277-288
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    • 2017
  • Objective: Treating Class II subdivision malocclusion with asymmetry has been a challenge for orthodontists because of the complicated characteristics of asymmetry. This study aimed to explore the characteristics of dental and skeletal asymmetry in Class II subdivision malocclusion, and to assess the relationship between the condyle-glenoid fossa and first molar. Methods: Cone-beam computed tomographic images of 32 patients with Class II subdivision malocclusion were three-dimensionally reconstructed using the Mimics software. Forty-five anatomic landmarks on the reconstructed structures were selected and 27 linear and angular measurements were performed. Paired-samples t-tests were used to compare the average differences between the Class I and Class II sides; Pearson correlation coefficient (r) was used for analyzing the linear association. Results: The faciolingual crown angulation of the mandibular first molar (p < 0.05), sagittal position of the maxillary and mandibular first molars (p < 0.01), condylar head height (p < 0.01), condylar process height (p < 0.05), and angle of the posterior wall of the articular tubercle and coronal position of the glenoid fossa (p < 0.01) were significantly different between the two sides. The morphology and position of the condyle-glenoid fossa significantly correlated with the three-dimensional changes in the first molar. Conclusions: Asymmetry in the sagittal position of the maxillary and mandibular first molars between the two sides and significant lingual inclination of the mandibular first molar on the Class II side were the dental characteristics of Class II subdivision malocclusion. Condylar morphology and glenoid fossa position asymmetries were the major components of skeletal asymmetry and were well correlated with the three-dimensional position of the first molar.