• Title/Summary/Keyword: k/s values

Search Result 11,524, Processing Time 0.038 seconds

Retrieval of LIDAR Aerosol Parameter Using Sun/Sky Radiometer at Gangneung, Korea

  • Shin, Sung-Kyun;Lee, Kwon-Ho;Lee, Kyu-Tae
    • Current Optics and Photonics
    • /
    • v.1 no.3
    • /
    • pp.175-185
    • /
    • 2017
  • The aerosol optical properties such as depolarization ratio (${\delta}$) and aerosol extinction-to-backscatter ratios (S, LIDAR ratio) and ${\AA}ngstr{\ddot{o}m$ exponent (${\AA}$) derived from measurement with AERONET sun/sky radiometer at Gangneung-Wonju National University (GWNU), Gangneung, Korea ($37.77^{\circ}N$, $128.87^{\circ}E$) during a winter season (December 2014 - February 2015) are presented. The PM concentration measurements are conducted simultaneously and used to identify the high-PM events. The observation period was divided into three cases according to the PM concentrations. We analysed the ${\delta}$, S, and ${\AA}$ during these high PM-events. These aerosol optical properties are calculated by the sun/sky radiometer data and used to classify a type of aerosols (e.g., dust, anthropogenic pollution). The higher values of ${\delta}$ with lower values of S and ${\AA}$ were measured for the dust particles. The mean values of ${\delta}$, S, and ${\AA}$ at 440-870 nm wavelength pair (${\AA}_{440-870}$) for the Asia dust were 0.19-0.24, 36-56 sr, and 0.48, respectively. The anthropogenic aerosol plumes are distinguished with the lower values of ${\delta}$ and higher values of ${\AA}$. The mean values of spectral ${\delta}$ and ${\AA}_{440-870}$ for this case varied 0.06-0.16 and 1.33-1.39, respectively. We found that aerosol columnar optical properties obtained from the sun/sky radiometer measurement are useful to identify the aerosol type. Moreover, the columnar aerosol optical properties calculated based on sun/sky radiometer measurements such as ${\delta}$, S, and ${\AA}$ will be further used for the validation of aerosol parameters obtained from LIDAR observation as well as for quantification of the air quality.

Design and manufacture of Bi-2223 HTS current leads for SMES magnet

  • Oh, S.S.;Cho, J.W.;Ha, H.S.;Sim, K.D.;Ha, D.W.;Seong, K.C.;Kwon, Y.K.;Ryu, K.S.;Kim, S.H.;Jang, H.M.
    • 한국초전도학회:학술대회논문집
    • /
    • v.10
    • /
    • pp.236-240
    • /
    • 2000
  • Bi-2223 HTS current leads for a superconducting magnetic energy storage(SMES) magnet were designed and manufactured. The HTS leads composed of Bi-2223/AgAu tapes and stainless steel former were connected to conventional vapor-cooled copper leads. The heat input to the liquid helium through the HTS lead was 0.39 W/lead when the warm end part's temperature is 65 K. And, the critical current of the HTS leads was about 1.6 kA when the warm end part's temperature is 80 K. The measured those values are well consistent with computed values.

  • PDF

An Analysis of the Relationships between Sense of Values and Clothing Image of Middle aged Women (중년여성의 가치관과 의복이미지의 관계 연구)

  • Ryoo, Sook-Hee;Shin, Soo-Ray
    • Journal of the Korean Home Economics Association
    • /
    • v.46 no.5
    • /
    • pp.111-121
    • /
    • 2008
  • The purpose of this study is to analyze the relationships between sense of values and clothing image of middle aged women. For this purpose, the subjects of 300 adult women from in their 40's to 50's, living in Daegu area were sampled out by convenient sampling method. The result of this analysis are as follows. 1)a factor analysis identified six different types of sense of value: materialistic, self-respect, relationship-conscious, sensation-conscious, practical, and people-conscious. 2)six different types of clothing image were identified: classy, bold, plain, feminine, casual, and peculiar. 3)the results of multiple regression analysis found that sense of values affected clothing image of middle aged women. This meant that significant relationships existed among these variables and there was a causal relationship between sense of values and clothing image.

Analysis and Measurement of RCS for UHF Band RFID Tag Antennas (UHF 대역 RFID 태그 안테나의 RCS(Radar Cross Sections) 분석 및 측정)

  • Moon, Hyo-Sang;Kim, Nam-Hoon;Lee, Jong-Wook;Lee, Bom-Son
    • The Journal of Korean Institute of Electromagnetic Engineering and Science
    • /
    • v.18 no.1 s.116
    • /
    • pp.31-36
    • /
    • 2007
  • In the RFID system, one of the important criteria of tag antenna performance is the detection distance. The most important factor determining the detection distance of the tag antenna is the Radar Cross Sections(RCS). In this paper, we propose a method to simply measure the RCS of the RFID tag antenna using two reader antennas(Tx and Rx) and a network analyzer. We estimate RCS' from the RCS equation based on the measured $S_{21}$ using the network analyzer. We compare the measured $S_{21}$ values with the calculated $S_{21}$ values and the simulated $S_{21}$ values using EM simulator. The used tag antennas are two kinds of dipole-type, metal-type, and an inductively-coupled type ones. In case of the dipole type, the measured, simulated and calculated values of the RCS are almost the same. In case of other types, we obtain the measured RCS values with a difference of about 3 dB.

Study on the Solubilization of 4-Halogenated Anilines by Cationic Surfactants (DTAB, TTAB, and CTAB) (양이온성 계면활성제(DTAB, TTAB 및 CTAB)에 의한 4-할로겐화 아닐린의 가용화에 대한 연구)

  • Lee, Byung-Hwan;Lee, Dong-Cheol
    • Journal of the Korean Applied Science and Technology
    • /
    • v.38 no.4
    • /
    • pp.994-1002
    • /
    • 2021
  • The solubilization constants (Ks) of 4-halogenated aniline derivatives by cationic surfactants (DTAB, TTAB, and CTAB) were measured by the UV-Vis method. As a result, the Ks values decreased as the temperature increased for all the aniline derivatives and showed a tendency to increase as the radius of the halogen substituent and the hydrophobic length of surfactant increased. The calculated values of ΔGo and ΔHo for these solubilizations all showed negative values within the measured range, but all the ΔSo values showed positive values. For all the 4-halogenated anilines, the ΔGo values all tended to decrease as the temperature increased, but both values of ΔHo and ΔSo showed a tendency to increase. In addition, as the radius of the halogen substituent increased, the values of ΔHo and ΔSo tended to decrease in general. However, when the hydrophobic group length of the surfactant was increased, the values of these thermodynamic functions showed a tendency to increase in general, although it differed depending on the type of aniline derivative. From the changes of such functions, it was possible to estimate the type and strength of interactions between 4-halogenated aniline and micelle, and the location at which they were solubilized in the micelle.

Accuracy of linear approximation for fitted values in nonlinear regression

  • Kahng, Myung-Wook
    • Journal of the Korean Data and Information Science Society
    • /
    • v.24 no.1
    • /
    • pp.179-187
    • /
    • 2013
  • Bates and Watts (1981) have discussed the problems of reparameterizing nonlinear models in obtaining accurate linear approximation confidence regions for the parameters. A similar problem exists with computing confidence curves for fitted values or predictions. The statistical behavior of fitted values does not depend on the parameterization. Thus, as long as the intrinsic curvature is small, standard Wald intervals for fitted values are likely to be sufficient. Accuracy of linear approximation for fitted values is investigated using confidence curves.

A Study on the Relationship between Social Values and Clothing Motivations for a Group of Female College Students in Seoul (여대생의 사회적 가치관과 의복 착용 동기와의 관계 -서울을 중심으로-)

  • Kim Kyung Hee;Lim Sook Ja
    • Journal of the Korean Society of Clothing and Textiles
    • /
    • v.7 no.2
    • /
    • pp.1-10
    • /
    • 1983
  • The purpose of this study is to investigate the relationship between the social values and the clothing motivations for a group of female college students in Seoul, Korea. Through this study, the followings were found : 1. A significant relationship was found between the social values and the five dothing motivations : Decoration, Modesty, Protection, Belongingness, Self-Esteem. 2. A significant relationship was found between the clothing motivations and the environmental factors concerning school : college type (coeducational college or women's college), major. grade. 3. A significant relationship was found between the clothing motivations and the environmental factors concerning family : father's income, father's educational level, order among sisters.

  • PDF

Dyeing Properties Wood Dyes by Screen Printing (날염을 이용한 소목의 염색성에 관한 연구)

  • 김은경;장지혜
    • Journal of the Korean Home Economics Association
    • /
    • v.38 no.9
    • /
    • pp.119-130
    • /
    • 2000
  • The purpose of this study was to confirm the possibility of screen printing with Natural dyes. The coloring matter such as sappan wood was used in order to obtain the colorant powder through the processes of extraction, low pressure concentration and the spray dry. After the screen printing on silk and cotton fabrics with colorant, K/S value changes of color and color fastness were measured. The main resets were as follows : 1. The viscosity of printing thickeners of sappan wood powder was about 15,200 cps, and the highest K/S value of the fabrics printed with sappan wood was obtained at 90$\pm$2$\^{C}$ of steaming temperature and 80 minutes of steaming time. 2. For the fabrics printed with sampan wood, adding of urea was not effective, since the more the concentration of urea increased, the more K/S values decreased. 3. For the natural dyes printing, the more the concentration of colorants increased, the more K/S values increased. In general, the K/S values of the printed fabrics were higher when treated with mordants rather than without mordants. Specifically, the λmax sappan wood was 520∼570 nm, and the K/S value was highest when treated with Cu mordant and lowest when treated with Sn. 4. Generally, the color fastness was relatively fair.

  • PDF

Field measurements of natural periods of vibration and structural damping of wind-excited tall residential buildings

  • Campbell, S.;Kwok, K.C.S.;Hitchcock, P.A.;Tse, K.T.;Leung, H.Y.
    • Wind and Structures
    • /
    • v.10 no.5
    • /
    • pp.401-420
    • /
    • 2007
  • Field measurements of the wind-induced response of two residential reinforced concrete buildings, among the tallest in the world, have been performed during two typhoons. Natural periods and damping values have been determined and compared with other field measurements and empirical predictors. Suitable and common empirical predictors of natural period and structural damping have been obtained that describe the trend of tall, reinforced concrete buildings whose structural vibrations have been measured in the collection of studies in Hong Kong compiled by the authors. This data is especially important as the amount of information known about the dynamic parameters of buildings of these heights is limited. Effects of the variation of the natural period and damping values on the alongwind response of a tall building for serviceability-level wind conditions have been profiled using the gust response factor approach. When using this approach on these two buildings, the often overestimated natural periods and structural damping values suggested by empirical predictors tended to offset each other. Gust response factors calculated using the natural periods and structural damping values measured in the field were smaller than if calculated using design-stage values.

A Study on the Quantative Analysis of a Ship's Collision Avoding Action by Using the Maneuvering Indices (조종성지수에 의한 충돌회피동작의 양적 파악에 관한 연구)

  • 윤점동
    • Journal of the Korean Institute of Navigation
    • /
    • v.1 no.1
    • /
    • pp.27-44
    • /
    • 1977
  • The Maneuvering Indices of a ship are the values that decide the quantity of her motion in turning when her rudder is turned over to an angle to the starboard or the port. They consist of two kinds of indices, one of which is called index K and the other, index T. Index K decides a ship's turning ability and index T does the length of time delay of a normal turning motion after her rudder has finished the turn of an ordered angle. Generally, the values of the indices are calculated through some mathematic formulas with figures of her heading degrees recorded at a fixed time intervals during her Z test. The values of the same kind index of a ship appear differently according to the ship'sspeed, trim, rudder angle and loaded condition, etc. In this paper, the author analyzed all the amthematic formulas required to calculate the values of the indices in their forming process and examined them from the point of mathematics and dynamics and also actually figured out the values of maneuvering indices of the M.S. "HANBADA", the training ship of Korea Merchant Marine College through her Z test. The author supposed a case in which two same typed ships as the "HANBADA" in size, shape and conditions were approaching each other in meeting end on situation and each ship turned her rudder hard over to the starboard respectively when they approached to the distance of 3 times as long as the ship's length. The author worked out mathematic formulas calculating forward and transverse ship's motions within the above mentioned situation for the quantative analysis of the collision avoding action to certify whether they are in collision status or not. Applying the calculated values of the maneuvering indices of the "HANBADA" to the motion calculating formulas, the author found out the two ships were passing over each other with the clearing distance o 39m between their port quarters. With the above mentioned examinations and explanations, the author demonstrated that a ship's motion in any collision avoiding action can be shown with quantities of time and distance within reliable limit.istance within reliable limit.

  • PDF