• Title/Summary/Keyword: shape characteristic

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A Study on the Design Characteristics of Multimedia Center in Public Library by Space Planning Elements (공공도서관 디지털자료실의 공간계획요소별 디자인특성 연구)

  • Lim, Eun-Young;Hwang, Yeon-Sook
    • Korean Institute of Interior Design Journal
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    • v.27 no.2
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    • pp.68-76
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    • 2018
  • A public library is changing into a place where people can freely acquire and make use of information in digital environment with the basic ideology of publicity. In spite of such changes, multimedia center is still biased with the function of computer room to use PC and is not used actively by many users. This study can be summarized and concluded as follows and spatial characteristics of digital data room of public library can make use of space planning elements by aspects as an analysis tool. First, designed characteristics focusing too much on the possession of seats for reading digital data. Therefore, spatial planning for users to choose necessary facilities according to the data they wish to read and type of users is needed. Second, interior tone of multimedia center is applied with identical color for all floors, walls, and ceilings, to create sense of unification. However, due to the arrangement of similar colors, while using identical brightness and chroma, some users felt difficult to realize shape or depth in space. It is more appropriate to apply distinctive color plan according to the characteristic of the data or space region, in order to create pleasant digital environment for visually weaker people or elderly. Third, psychological or technical factors of multimedia center is not sufficiently applied in space planning elements for users. In order for various digital service of public library to be technically implemented, it is necessary to organize open space by expanding the size of multimedia center to utilize high-tech facilities.

Accuracy of maximal expiratory flow-volume curve curvilinearity and fractional exhaled nitric oxide for detection of children with atopic asthma

  • Park, Sang Hoo;Im, Min Ji;Eom, Sang-Yong;Hahn, Youn-Soo
    • Clinical and Experimental Pediatrics
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    • v.60 no.9
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    • pp.290-295
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    • 2017
  • Purpose: Airway pathology in children with atopic asthma can be reflected by the concave shape of the maximal expiratory flow-volume (MEFV) curve and high fractional exhaled nitric oxide (FeNO) values. We evaluated the capacity of the curvilinearity of the MEFV curve, FeNO, and their combination to distinguish subjects with atopic asthma from healthy individuals. Methods: FeNO and angle ${\beta}$, which characterizes the general configuration of the MEFV curve, were determined in 119 steroid-naïve individuals with atopic asthma aged 8 to 16 years, and in 92 age-matched healthy controls. Receiver operating characteristic (ROC) curve analyses were performed to determine the cutoff points of FeNO and angle ${\beta}$ that provided the best combination of sensitivity and specificity for asthma detection. Results: Asthmatic patients had a significantly smaller angle ${\beta}$ and higher FeNO compared with healthy controls (both, P<0.001). For asthma detection, the best cutoff values of angle ${\beta}$ and FeNO were observed at $189.3^{\circ}$ and 22 parts per billion, respectively. The area under the ROC curve for the combination of angle ${\beta}$ and FeNO improved to 0.91 (95% confidence interval [CI], 0.87-0.95) from 0.80 (95% CI, 0.75-0.86; P<0.001) for angle ${\beta}$ alone and 0.86 (95% CI, 0.82-0.91; P=0.002) for FeNO alone. In addition, the combination enhanced sensitivity with no significant decrease in specificity. Conclusion: These data suggest that the combined use of the curvilinearity of the MEFV curve and FeNO is a useful tool to differentiate between children with and without atopic asthma.

Geometric Characteristics of Methane Steam Reforming with Low Temperature Heat Source (중저온 열원에 의한 메탄 수증기 개질의 형상 인자에 따른 특성)

  • Shin, Gahui;Yun, Jinwon;Yu, Sangseok
    • Transactions of the Korean Society of Mechanical Engineers B
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    • v.40 no.12
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    • pp.793-799
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    • 2016
  • In a hybrid fuel cell system, low-temperature reforming technology, which uses waste heat as a heat source, is applied to improve system efficiency. A low temperature reformer is required to optimize geometry in low thermal conditions so that the reformer can achieve the proper methane conversion rate. This study analyzed internal temperature distributions and the reaction patterns of a reformer by considering the change of the shape factor on the limited heat supply condition. Unlike the case of a high temperature reformer, analysis showed that the reaction of a low temperature reformer takes place primarily in the high temperature region of the reactor exit. In addition, it was confirmed that the efficiency can be improved by reducing the GHSV (gas hourly space velocity) or increasing the heat transfer area in the radial direction. Through reacting characteristic analysis, according to change of the aspect ratio, it was confirmed that a low temperature reformer can improve the efficiency by increasing the heat transfer in the radial direction, rather than in the longitudinal direction.

Comparative Study on Unsaturated Characteristic Curves of Boeun Granite Weathered Soil during Drying and Wetting Paths (건조 및 습윤과정에서 보은 화강암 풍화토의 불포화특성곡선 비교)

  • Song, Young-Suk
    • Journal of the Korean Geotechnical Society
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    • v.32 no.7
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    • pp.15-24
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    • 2016
  • To investigate the unsaturated characteristics of the Boeun granite weathered soil, matric suction and volumetric water content were measured in both drying and wetting paths using Automated Soil-Water Characteristics Curve Apparatus. Based on the measured results, Soil-Water Characteristics Curve was estimated by van Genuchten (1980) model. The relationship between effective degree of saturation and matric suction showed the non-linear curve with S-shape and the hysteresis phenomenon occurred during drying and wetting paths. Suction Stress Characteristics Curve was estimated by the Lu and Likos (2006) model. The suction stress in drying path was constantly maintained and that in wetting path tended to increase when the effective degree of saturation was low. But the suction stress in drying path was larger than that in wetting path at the same degree of saturation when the effective degree of saturation became larger. Meanwhile, Hydraulic Conductivity Function was evaluated by the van Genuchten (1980) model which is one of the parameter estimation methods. The unsaturated hydraulic conductivity decreased with increasing the matric suction, and the decreasing velocity regarding to the matric suction in drying path was larger than that in wetting path.

The Characteristic of Decoration in Indonesian Traditional House - Focused Javanese Hous - (인도네시아 전통주택의 의장 특성에 관한연구 - 자바주택을 중심으로 -)

  • Kim, Do-Yeon;Ju, Seo Ryeung;Oh, Hye-Kyung
    • Journal of the Korean housing association
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    • v.25 no.6
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    • pp.111-121
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    • 2014
  • The purpose of the study is to understand the unique characteristics of decoration style in traditional Javanese houses. Reviewing literature and visiting site were applied as the research method. Javanese House can be divided into three parts; roof, wall and floor. First, the roof of the traditional Javanese House is the most unique and important decorative element. The roofs are covered with roof-tiles and have clay carving ornaments on top. Usually there are no ceilings, just exposed to the oblique shape roof, which are made of wood to enable air ventilation. Joglo roof is the outstanding and representative roof type of Javanese houses. There is artistic and constructive roof structure named as tumpang sari in Joglo roof. The decoration on tumpang sari is the most colorful and symbolic ornaments. Secondly, the most unique element in the wall is the gebyok. Gebyok is made of wood and full of carved ornament, which has an artistic appearance, and also important function. The top part of doors are designed as perforated woodcarving, which give both aesthetic and ventilation purposes. Last, the stratified floor is begin with ground yard, then veranda that made from hardened clay, and main room constituted with a wood scaffold to provide air circulation and remove the humidity of the ground. The decorations of the column stand (umpak) are unique, where usually lotus flower is carved into black stone or lime stone. The outside of the buildings in Java Houses is not decorated by colors or symbols, whereas colors are only used in temples, pavilion or in royal housings. Instead they have carvings and decorations on important structural elements such as columns and beams inside. The ornaments and colors of decorations symbolize their god, ancestors and piece.

Shape Characteristics of Exhaust Plume of Dual-Stage Plasma Thruster using Direct-Current Micro-Hollow Cathode Discharge (직류 마이크로 할로우 음극 방전을 이용한 이단 마이크로 플라즈마 추력기의 배기 플룸의 형상 특성)

  • Ho, Thi Thanh Trang;Shin, Jichul
    • Journal of the Korean Society of Propulsion Engineers
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    • v.20 no.3
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    • pp.54-62
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    • 2016
  • Micro plasma thruster (${\mu}PT$) was studied experimentally with a dual-stage micro-hollow cathode discharge (MHCD) plasma. Electrostatic-like acceleration exhibiting more directional and elongated exhaust plume was achieved by a dual layer MHCD at the total input power less than 10 W with argon flow rate of 40 sccm. V-I characteristic indicated that there was an optimal regime for dual-stage operation where the acceleration voltage across the second stage remained constant. Estimated exhaust plume length showed a similar trend to the analytic estimate of exhaust velocity which scales with an acceleration voltage. ${\mu}PT$ with multiple holes exhibited similar performance with single-hole thruster indicating that higher power loading is possible owing to decreased power through each hole. Boltzmann plot of atomic argon spectral lines showed average electron excitation temperature of about 2.6 eV (~30,170 K) in the exhaust plume.

Ozone Production Characteristics of the DBD Discharge the Electrode Shape at the Same Electrode surface area (동일한 전극 표면적에서 DBD방전형 내부전극 형상에 따른 오존생성특성 연구)

  • Kwon, Young-Hak;Park, Hyunmi;Song, HyunGig;Park, Won-Zoo
    • Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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    • v.30 no.2
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    • pp.71-77
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    • 2016
  • The dielectric barrier discharge (DBD) has low efficiency due to about 70% input power is consumed as thermal energy in the discharge space. However, because of the usage of DBD ozone generator is easier than other methods. The DBD ozone generator has been widely applied for high concentration ozone generation in the industrial application. But, the low-capacity compact DBD ozone generator is not applied so far. Therefore, the DBD ozone generator is necessary to improve ozone production efficiency and reduce the capacity. In this paper, the stainless steel pipe inner electrode was designed with hall type and screw type to improve the ozone production yield. The manufactured two inner electrodes were experimented with normal type for comparison of the discharge characteristics and the ozone generating characteristics. As the experimental results, the discharge current effective value of designed inner electrodes with hall type and screw type are higher than the normal type, due to unequal electric field is formed at the boundary. However, the difference of designed and original electrodes is less than 0.1mA that has no effect on the discharge characteristic. On the other hand, the screw type inner electrode increased higher than original model about 7 times when the flow rate of the oxygen source gas was increased from $0.6{\ell}/min$ to $1.0{\ell}/min$ The reason was assumed by the flow rate of the raw gas through the inner electrode was became fast that has a cooling effect. The designed hall type and screw type inner electrodes have shown good performances in ozone generation and ozone production that better than normal type in the same electrode surface area.

A Study on Statistical Properties of Vickers Hardness of Friction Welded Parts in Alloy718 Steel (Part 1. As-welded) (Alloy718 마찰용접재의 비커스 경도의 통계적 성질에 관한 연구 (As-welded 재의 경우를 중심으로))

  • Kwon, Hyeok-Yong;Choi, Sung-Yoong;Lee, Sang-Yeal;Kong, Yu-Sik;Kim, Seon-Jin
    • Journal of Ocean Engineering and Technology
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    • v.22 no.5
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    • pp.87-93
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    • 2008
  • The objective of this paper is the investigation of the statistical properties of Vickers hardness (HV) of friction welded parts in nickel based super resisting steel, alloy 718 steel. First, we examine the statistical properties on the case of as-welded parts. Several Virkers indentations were made under same nominal conditions. This was repeated for three different applied loads, 100, 200 and 300g with a duration time, 10 second. The arithmetic mean of Vickers hardness in base metal (BM) materials is larger than that of HAZ in all applied loads. The measure of dispersion, that is, the coefficient of variation (COV) for BM and HAZ is decreased by increasing with the applied load. The distribution of Vickers hardness was not found to be symmetric type. The probability distribution of Vickers hardness was well followed Weibull distribution. The shape parameter and the scale parameter (characteristic hardness) are increased by increasing with the applied load, as both BM and HAZ.

Effect of Metabolic Inhibition on Inward Rectifier K Current in Single Rabbit Ventricular Myocytes (토끼 단일 심근세포에서 대사억제시 Inward Rectifier$(I_{K1})$의 변화)

  • Chung, Yu-Jeong;Ho, Won-Kyung;Earm, Yung-E
    • The Korean Journal of Physiology and Pharmacology
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    • v.1 no.6
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    • pp.741-748
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    • 1997
  • In the present study, we have investigated the effect of metabolic inhibition on the inward rectifier K current ($I_{K1}$). Using whole cell patch clamp technique we applied voltage ramp from +80 mV to -140 mV at a holding potential of -30 mV and recorded the whole cell current in single ventricular myocytes isolated from the rabbit heart. The current-voltage relationship showed N-shape (a large inward current and little outward current with a negative slope) which is a characteristic of $I_{K1}$. Application of 0.2 mM dinitrophenol (DNP, an uncoupler of oxidative phosphorylation as a tool for chemical hypoxia) to the bathing solution with the pipette solution containing 5 mM ATP, produced a gradual increase of outward current followed by a gradual decrease of inward current with little change in the reversal potential (-80 mV). The increase of outward current was reversed by glibenclamide ($10\;{\mu}M$), suggesting that it is caused by the activation of $K_{ATP}$. When DNP and glibenclamide were applied at the same time or glibenclamide was pretreated, DNP produced same degree of reduction in the magnitude of the inward current. These results show that metabolic inhibition induces not only the increase of $K_{ATP}$ channel but also the decrease of $I_{K1}$. Perfusing the cell with ATP-free pipette solution induced the changes very similar to those observed using DNP. Long exposure of DNP (30 min) or ATP-free pipette solution produced a marked decrease of both inward and outward current with a significant change in the reversal potential. Above results suggest that the decrease of $I_{K1}$ may contribute to the depolarisation of membrane potential during metabolic inhibition.

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Effect of tannin contents on the physicochemical characteristics of acorn starch (탄닌함량에 따른 도토리전분의 물리화학적 특성)

  • Ahn, Ho-Kyoung;Choi, Hyeong-Taeg;Kim, Byong-Lyoung;Oh, Doo-Hwan
    • Applied Biological Chemistry
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    • v.33 no.4
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    • pp.301-306
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    • 1990
  • The Physical and chemical properties or dry acorn starch(DS), detannined acorn starch (DTS) and defatted and detannined acorn starch(Drn) were investigated. Ail acorn starch sample, observed by a scanning electron microscope, showed a hemispherical shape ud its size was about $5{\sim}10{\mu}m$ in diameter. It had a little change on the pasting temperature of DS, DTS and DFTS but peak viscosity of DTS was somewhat higher than that of n. Flow behavior of gelatinized starch pastes showed a pseudoplastic behavior and flow behavior index was lower than unit. The consistency coefficient showed concentraion and temperature dependency. The activation energies of DS, DTS and DFTS were $2.09{\sim}3.58Kcal/g\;{\cdot}\;mol and time dependent characteristic of acorn starch samples showed thixotrpic behavior.

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