• Title/Summary/Keyword: limiting normal

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The Study on a sensitive current limiting breaking device using RF Sputtering (RF Sputtering을 이용한 전류 민감성 차단 디바이스에 관한 연구)

  • Lee, S.H.;Jeong, K.H.;Park, D.K.;Kim, Y.L.;Lee, J.C.;Koo, K.W.;Han, S.O.
    • Proceedings of the KIEE Conference
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    • 1995.07c
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    • pp.1088-1092
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    • 1995
  • In this paper, we evaluated the sputter-deposited Cr/Cu thin film fuses on $Al_2O_3$ substrates by the adhesive, breaking and repetitive over-current test as a function of temperature on them. Each Cr and Cu was deposited $1700{\pm}300{\AA},\;3700{\pm}300{\AA}$ using RF sputtering unit. The electroplated Cu of $25{\mu}m$ thickness was added in order to make sensitive thin film fuse of the normal current 15[A]. The adhesive strength and the number of repetition were Increasing and then decreasing with the temperature. The maximum adhesive strength of over $9kgf/9mm^2$ was obtained at $400^{\circ}C$. In the breaking test, the post-arc time characteristic was better than any other factor.

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Botox Injection for the Management of Spasmodic Dysphonia (연축성 발성장애(Spasmodic Dysphonia)에 대한 보톡스 주입치료)

  • Choi, Hong-Shik
    • Journal of the Korean Society of Laryngology, Phoniatrics and Logopedics
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    • v.23 no.2
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    • pp.99-103
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    • 2012
  • Spasmodic dysphonia is a chronic, focal, movement-induced, action-specific dystonia of the laryngeal musculature during speech. It can have a profound effect on quality of life, severely limiting people's communication, especially via telephone and in noisy backgrounds. Spasmodic dysphonia (SD) is usually of the adductor type characterized by glottic contractions causing tightness and voice breaks with forced-strangled voice, but it may also be abductor type or, much less commonly, mixed. Treatment options for adductor spasmodic dysphonia (ADSD) include voice therapy, surgical procedures, and botulinum toxin injections (Botox). The use of Botox injected into the laryngeal muscles remains the "gold standard" treatment for reducing the vocal symptoms of ADSD and Botox induces a temporary paresis of the laryngeal muscles and provides short-term relief of symptoms. Repeated injections of the laryngeal muscles, generally every 3-4 months, are required for continuous relief of symptoms. Improvement in vocal function has been reported after use of Botox injections, though a completely normal voice is rarely achieved. In this hospital, 1,030 patients have been enrolled for Botox injection therapy so far (May, 2012). In this review article, I'd like to present my personal experience of management of spasmodic dysphonia mainly by Botox injection.

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Improvement of Field Screening for Winter Hardiness of Barley

  • Park Dong-Soo;Ko Jong-Min;Kim Hyun-Tae;Yang Sae-Jun;Kim Soon-Chul;Sohn Jae-Keun
    • KOREAN JOURNAL OF CROP SCIENCE
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    • v.50 no.4
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    • pp.276-280
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    • 2005
  • Low temperature is one of the most severe abiotic stress factors limiting growth, productivity and distribution of winter cereals. Reliable field screening method, which can detect small differences in winter survival, is important for the effective selection and development of plants to identity superior cold tolerant winter cereal genotypes. This study was undertaken to provide improved screening method of winter hardiness in the field by increasing the accuracy in evaluating winter hardiness of barley (Hordeum vulgare L.). We introduced furrow in field screening of winter survival. By sowing the plants at the ridge and base, we could minimize the effect of topographic variation in a field by giving higher and lower level of stress at the same time. This method could be used by breeders to conduct accurate evaluation of winter hardiness by selecting the better treatment, which shows close to normal distribution, among the winter survival rate from the ridge, base and mean survival rate of the two in a screening field.

A Variables Repetitive Group Sampling Plan for Minimizing Average Sample Number (평균 샘플 수 최소화를 통한 계량형 반복 샘플링 검사의 설계)

  • Park, Heekon;Moon, Young-gun;Jun, Chi-Hyuck;Balamurali, S.;Lee, Jaewook
    • Journal of Korean Institute of Industrial Engineers
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    • v.30 no.3
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    • pp.205-212
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    • 2004
  • This paper proposes the variables repetitive group sampling plan where the quality characteristic following normal distribution has upper or lower specification limit. The problem is formulated as a non-linear programming problem where the objective function to minimize is the average sample number and the constraints are related to lot acceptance probabilities at acceptable quality level (AQL) and limiting quality level (LQL) under the operating characteristic curve. Sampling plan tables are constructed for the selection of parameters indexed by AQL and LQL in the cases of known standard deviation and unknown standard deviation. It is shown that the proposed sampling plan significantly reduces the average sample number as compared with the single or the double sampling plan.

Vitamin D dependent rickets type I

  • Kim, Chan-Jong
    • Clinical and Experimental Pediatrics
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    • v.54 no.2
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    • pp.51-54
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    • 2011
  • Vitamin D is present in two forms, ergocalciferol (vitamin $D_2$) produced by plants and cholecalciferol (vitamin $D_3$) produced by animal tissues or by the action of ultraviolet light on 7-dehydrocholesterol in human skin. Both forms of vitamin D are biologically inactive pro-hormones that must undergo sequential hydroxylations in the liver and the kidney before they can bind to and activate the vitamin D receptor. The hormonally active form of vitamin D, 1,25-dihydroxyvitamin D3 $[1,25(OH)_2D]$, plays an essential role in calcium and phosphate metabolism, bone growth, and cellular differentiation. Renal synthesis of $1,25(OH)_2D$ from its endogenous precursor, 25-hydroxyvitamin D (25OHD), is the rate-limiting and is catalyzed by the $1{\alpha}$-hydroxylase. Vitamin D dependent rickets type I (VDDR-I), also referred to as vitamin D $1{\alpha}$-hydroxylase deficiency or pseudovitamin D deficiency rickets, is an autosomal recessive disorder characterized clinically by hypotonia, muscle weakness, growth failure, hypocalcemic seizures in early infancy, and radiographic findings of rickets. Characteristic laboratory features are hypocalcemia, increased serum concentrations of parathyroid hormone (PTH), and low or undetectable serum concentrations of $1,25(OH)_2D$ despite normal or increased concentrations of 25OHD. Recent advances have showed in the cloning of the human $1{\alpha}$-hydroxylase and revealed mutations in its gene that cause VDDR-I. This review presents the biology of vitamin D, and $1{\alpha}$-hydroxylase mutations with clinical findings.

The Growth Patterns of Major Landscaping Trees by Site Conditions in Two Apartment Complexes (아파트단지내 조경용 교목의 입지조건별 생장특성)

  • 윤근영;안건용
    • Journal of the Korean Institute of Landscape Architecture
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    • v.26 no.2
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    • pp.207-218
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    • 1998
  • A site survey in two apartment complexes and a nursery experiment were carried out in this study to provide basic data of the long-pending growth characteristics of major landscaping trees, such as Picea abies, Pinus parviflora, Metasequoia glyptostroboides, Magnolia denudata, Acer buergerianum and Acer palmatum. According to the main results, the survival rates were very low, reflected by the average survival rate of the four species was 95% at the nursery site. And, it was presumed that the site conditions of two apartment complexes for tree growth were very inferior to those of the nursery site, taking into consideration that the increment percents of growth factors of the tree species at the nursery site were relatively higher than those of the apartment complexes. The distribution patterns of the current growth factors of trees showed a normal distribution. The regression equation of breast diameter on diameter at root collar showed especially high predictability. And, it was thought that the most critical limiting environmental factors on tree growth at the apartment complexes were found to be alkaline pH caused by excessive Ca, high percent base saturation, insufficiency of available moisture content, bad drainage due to inferior soil texture, high soil hardness, lack of organic matter and shortage of cation exchange capacity in soil.

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Dual Substituent Effects on Anilinolysis of Bis(aryl) Chlorothiophosphates

  • Barai, Hasi Rani;Lee, Hai Whang
    • Bulletin of the Korean Chemical Society
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    • v.34 no.12
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    • pp.3597-3601
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    • 2013
  • The reactions of bis(Y-aryl) chlorothiophosphates (1) with substituted anilines and deuterated anilines are investigated kinetically in acetonitrile at $55.0^{\circ}C$. The Hammett plots for substituent Y variations in the substrates show biphasic concave upwards with a break point at Y = H. The cross-interaction constants (${\rho}_{XY}$) are positive for both electron-donating and electron-withdrawing Y substituents. The kinetic results of 1 are compared with those of Y-aryl phenyl chlorothiophosphates (2). The cross-interaction between Y and Y, due to additional substituent Y, is significant enough to result in the change of the sign of ${\rho}_{XY}$ from negative with 2 to positive with 1. The effect of the cross-interaction between Y and Y on the rate changes from negative role with electron-donating Y substituents to positive role with electron-withdrawing Y substituents, resulting in biphasic concave upward free energy correlation with Y. A stepwise mechanism with a rate-limiting leaving group departure from the intermediate involving a predominant frontside attack hydrogen bonded, four-center-type transition state is proposed based on the positive sign of ${\rho}_{XY}$ and primary normal deuterium kinetic isotope effects.

Kinetics and Mechanism of the Benzylaminolysis of O,O-Dimethyl S-Aryl Phosphorothioates in Dimethyl Sulfoxide

  • Adhikary, Keshab Kumar;Barai, Hasi Rani;Lee, Hai-Whang
    • Bulletin of the Korean Chemical Society
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    • v.32 no.12
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    • pp.4304-4308
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    • 2011
  • Kinetic studies of the reactions of O,O-dimethyl Z-S-aryl phosphorothioates with X-benzylamines have been carried out in dimethyl sulfoxide at $85.0^{\circ}C$. The Hammett (log $k_2$ vs ${\sigma}_X$) and Br$\ddot{o}$nsted [log $k_2$ vs $pK_a$(X)] plots for substituent X variations in the nucleophiles are discrete with a break region between 4-Me and H, while the Hammett plots (log $k_2$ vs ${\sigma}_Z$) for substituent Z variations in the leaving groups are linear. The sign of the cross-interaction constant (${\rho}_{XZ}$) is positive for both the strongly and weakly basic nucleophiles. Greater magnitude of ${\rho}_{XZ}$ (= 2.54) value is observed with the weakly basic nucleophiles compared to with the strongly basic nucleophiles (${\rho}_{XZ}$ = 0.17). The deuterium kinetic isotope effects ($k_H/k_D$) involving deuterated benzylamines [$XC_6H_4CH_2ND_2$] are primary normal ($k_H/k_D$ > 1). The proposed mechanism is a stepwise with a rate-limiting leaving group expulsion from the intermediate involving a frontside nucleophilic attack with a hydrogen bonded, four-center-type transition state for both the strongly and weakly basic nucleophiles.

Short-circuit Analysis by the Application of Control Signal of Power Converter to the Inductive Fault Current Limiter

  • Ahn, Min-Cheol;Hyoungku Kang;Bae, Duck-Kweon;Minseok Joo;Park, Dong-Keun;Lee, Sang-Jin;Ko, Tae-Kuk
    • Progress in Superconductivity and Cryogenics
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    • v.6 no.2
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    • pp.25-28
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    • 2004
  • Three-phase inductive superconducting fault current limiter (SFCL) with DC reactor rated on 6.6 $KV_{rms}/200 A_{rms}$ has been developed in Korea. This system consists of one DC reactor, AC/DC power converter, and a three-phase transformer, which is called magnetic core reactor (MCR). This paper deals with the short-circuit analysis of the SFCL. The DC reactor was the HTS solenoid coil whose inductance was 84mH. The power converter was performed as the dual-mode operation for dividing voltage between the rectifying devices. The short-term normal operation (1 see) and short-circuit tests (2∼3 cycles) of this SFCL were performed successfully. In regular short-circuit test, the fault current was limited as 30% of rated short-circuit current at 2 cycles after the fault. The experimental results have a very similar tendency to the simulation results. Using the technique for the fault detection and SCR firing control, the fault current limiting rate of the SFCL was improved. From this research, the parameters for design and manufacture of large-scale SFCL were obtained.

Characteristics of a FCL Applying Fast Interrupter According to the Current Limitation Elements (고속 인터럽터를 적용한 한류기의 전류제한요소에 따른 특성)

  • Im, In-Gyu;Choi, Hyo-Sang;Jung, Byung-Ik
    • The Transactions of The Korean Institute of Electrical Engineers
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    • v.61 no.11
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    • pp.1752-1757
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    • 2012
  • With the development in industry, power demand has increased rapidly. As consumption of power has increased, Demand for new power line and electric capacity has risen. However, in the event of fault, problems occur in extending the range of fault coverage and increasing fault current. In these reasons, protection devise is recognized as the prevention of an accident and fault current. This paper dealt with minimizing fault propagation and limiting fault current by adjusting fault current limiter (FCL) with fast interrupter. At this point, we compared and analyzed characteristics between non-inductive resistance and fault current which is limited by superconducting units. In normal state of the power system, power was supplied to the load, but when fault occurred, the interrupter was operated as CT which detected the over-current. Its operation made the limitation of fault current through a FCL. We concluded that the limiter using superconducting units was more efficient with the increase of power voltage. Superconducting fault current limiter with the fast interrupter prevented the spread of a fault, and improved reliability of power system.