• Title/Summary/Keyword: Physical Mode

Search Result 675, Processing Time 0.024 seconds

Subjective Evaluation of Wear Comfort and Related Physical Variables under Warm and Humid Condition (고온 다습한 환경에서의 주관적 착용 쾌적감과 관련 물성 변인)

  • Kim, Jeong-Hwa;Hong, Gyeong-Hui;Jo, Seung-Sik
    • Journal of the Korean Society of Clothing and Textiles
    • /
    • v.21 no.6
    • /
    • pp.1021-1030
    • /
    • 1997
  • Physical variables related to the subjective evaluation of wear comfort were explored. Experimental fabrics was those used in the previous paper where subjective sensations of women's thin shirts were reported. Fabrics include 100% cotton (unfinished), 100% cotton (water repellent finished), cotton/polyester 35/65 (unfinished), cotton/polyester 35/65 (peach skin finished), 100% polyester fabric(plain), 100% polyester crepe. Among various physical properties of the experimental fabrics, heat 8E moisture transport properties and surface properties were chosen as important variables based on the regression coefficient. Especially, humidity at the microclimate in dynamic mode was highly correlated to the subjective evaluation and appeared to be a sensitive physical predictor, compared to dry thermal transmission rate or water vapor transmission rate. Surface characteristic parameters, however, did not show consistant trend in the prediction of the human's subjective sensation. Interaction between surface properties and humidity measurement was also observed.

  • PDF

Utilizing virtual vibration tests to optimize physical endurance tests

  • Kihm, Frederic
    • Advances in aircraft and spacecraft science
    • /
    • v.5 no.2
    • /
    • pp.239-249
    • /
    • 2018
  • Physical tests are performed at various stages of the development cycle of a product, from prototype validation to product qualification. Although costly, there are growing demands for qualification tests like endurance vibration testing to be more representative of the real world. At the same time there are growing demands to assess the durability of these items based on FEA simulation. In this paper, we will explain how to set up a CAE-based test and how to correlate the results with some physical measurements. Specific assumptions will be explained and some advantages of using virtual tests will be highlighted such as the reduction of the number of prototypes needed, investigations on failures, evaluation of the level of reliability via sensitivity analysis, evaluation of the margins are at the end of a successful test. This presentation will therefore focus on explaining and showing how virtual tests can enrich the exploitation of physical tests.

Evaluation of Spin Direction in Ferrite-Plated Films by $Fe^{57}$ Conversion Electron Mossbauer Spectroscopy

  • Shirasaki, Fumio;Kitamoto, Yoshitaka;Kantake, Shusuke;Abe, Masanori
    • The Korean Journal of Ceramics
    • /
    • v.6 no.4
    • /
    • pp.405-407
    • /
    • 2000
  • Polycrystalline films of Ni- and Co-ferrites films are prepared from aqueous solution at $90^{\circ}C$ by ferrite plating, which are subjected to Fe$^57$ conversion electron Mossbauer spectroscopy in backscatter mode. The average angle of Fe spins relative to the film plane is evaluated as 18 degree and 82 degree for the Ni- and Co-ferrite films, respectively, indicating a prominent magnetic anisotropy parallel and perpendicular to the film plane. It was also verified by the magnetization measurements.

  • PDF

Determination of Physical Dimensions of ${\mu}$ Cassiopeiae

  • Bach, Kie-Hunn;Kang, Won-Seok
    • Bulletin of the Korean Space Science Society
    • /
    • 2010.04a
    • /
    • pp.35.1-35.1
    • /
    • 2010
  • Using the spectroscopic analysis and the theoretical modeling, physical properties of the nearby astrometric binary $\mu$ Cas have been determined. In spite of the well-defined parallax and astrometric orbit, there has been a chronic mass ratio problem between components. Recently, the radius of the primary component has been detected from the optical interferometric observation of the CHARA array. Using the high resolution spectroscopic analysis, we found that $\mu$ Cas have $\alpha$-enhanced chemical composition with respect to the scaled solar abundance by a factor of two. Combining our abundance analysis with recently determined physical properties, the consistent models for $\mu$ Cas have been constructed within the frame work of standard stellar theory. Through a statistical minimization between theoretical model grids, a reliable set of physical dimensions has been defined. Furthermore, the mode oscillation frequency of the best model has been calculated.

  • PDF

A temperature adjustment process of stratified fluid induced simultaneously by sidewall thermal variation and vertical through-flow (용기의 온도변화와 수직관류가 동시에 작용하는 성층유체의 과도유동)

  • Park, Jun-Sang;Hyun, Jae-Min
    • Proceedings of the KSME Conference
    • /
    • 2001.06e
    • /
    • pp.450-455
    • /
    • 2001
  • An analytical study is made of transient adjustment process of an initially stationary, stably-stratified fluid in a square. The boundary walls are highly-conducting. The overall Rayleigh number $R_a$ is large. Considerations are given to both opposing (${\delta}w/{\delta}T>0$) and cooperating (${\delta}w/{\delta}T<0$) configurations. The flow character in opposing configuration can be classified into (a) a forced-convection dominaut mode (${\delta}w/{\delta}T>1/\sqrt{2}$), (b) a buoyancy-convection dominant mode ($0<{\delta}w/{\delta}T<1/\sqrt{2}$), and (c) a static mode (${\delta}w/{\delta}T{\cong}1/\sqrt{2}$). Global evolutionary processes are depicted. and physical rationalizations are provided.

  • PDF

The Effect of Primary Solidification Mode on Physical Properties of Austenitic Stainless Steels (오스테나이트계 스텐리스 강의 물성에 미치는 초정응고 형식의 영향)

  • 정호신
    • Journal of the Korean Society of Fisheries and Ocean Technology
    • /
    • v.26 no.4
    • /
    • pp.372-379
    • /
    • 1990
  • The effect of primary solidification phase on the solidification cracking sensitivity, corrosion resistance and toughness at cryogenic temperature was investigated for the austenitic stainless steel welds. The conclusions were summarized as follows; 1. Soldification crack sensitivity of austenitic stainless steel welds depends on the primary solidification mode. 2. Austenitic stainless steels were very susceptible to solidification cracking in case of solidification as primary ${\gamma}$ and immune when solidified as primary $\delta$. 3. When the ratio of Creq/Nieq is in the range of 1.46 to 1.55, the most resistance against solidification cracking was obtained. These results agreed well with the relationship between primary solidification mode, corrosion resistance and toughness at cryogenic temperature. 4. Optimum toughness, corrosion and solidification cracking resistance can be obtained when alloys having chemical compositions described above and solidifies as primary $\delta$ containing no ferrite at room temperature.

  • PDF

Dynamic Modeling and Control of Flexible Space Structures

  • Chae, Jang-Soo;Park, Tae-Won
    • Journal of Mechanical Science and Technology
    • /
    • v.17 no.12
    • /
    • pp.1912-1921
    • /
    • 2003
  • This paper presents a global mode modeling of space structures and a control scheme from the practical point of view. Since the size of the satellite has become bigger and the accuracy of attitude control more strictly required, it is necessary to consider the structural flexibility of the spacecraft. Although it is well known that the finite element (FE) model can accurately model the flexibility of the satellite, there are associated problems : FE model has the system matrix with high order and does not provide any physical insights, and is available only after all structural features have been decided. Therefore, it is almost impossible to design attitude and orbit controller using FE model unless the structural features are in place. In order to deal with this problem, the control design scheme with the global mode (GM) model is suggested. This paper describes a flexible structure modeling and three-axis controller design process and demonstrates the adequate performance of the design with respect to the maneuverability by applying it to a large flexible spacecraft model.

A Study on the Economical Feasibility Analysis For Development of Dual Mode Trailer System

  • Kim, Kwang-Hee
    • Journal of Navigation and Port Research
    • /
    • v.34 no.2
    • /
    • pp.137-144
    • /
    • 2010
  • In light of the growing traffic congestion problem and congestion cost, the container transport by railway has to be increased. The freight transport by railway can have decided advantages over trucks in terms of energy efficiency, emissions and cost for certain freight movements, just as transportation in the metropolitan region can have great advantages over driving truck. But the freight transport by truck should gain significant mobility benefits from a freight railway system. Thus, the DMT(Dual Mode Trailer) transport system which is coupled railway transport advantages with load transport advantages has been developed and used in the european countries. The DMT transport will therefore serve the areas required by transport organizers. The purpose of this paper is to estimate economical feasibility analysis for development of DMT transport system. Consequently, this study analyzed the characteristics of the DMT system. The horizontal load.unload system is being considered as an adoptable DMT system in consideration of the situation in Korea.

Structural dynamic optimization with probability constraints of frequency and mode

  • Chen, Jian-Jun;Che, Jian-Wen;Sun, Huai-An;Ma, Hong-Bo;Cui, Ming-Tao
    • Structural Engineering and Mechanics
    • /
    • v.13 no.5
    • /
    • pp.479-490
    • /
    • 2002
  • The structural dynamic optimization problem based on probability is studied. Considering the randomness of structural physical parameters and the given constraint values, we develop a dynamic optimization mathematical model of engineering structures with the probability constraints of frequency, forbidden frequency domain and the vibration mode. The sensitivity of structural dynamic characteristics based on probability is derived. Two examples illustrate that the optimization model and the method applied are rational and efficient.

A comparison study of measured values and subjective experience of mercury thermometer and tympanic thermometer (수은체온계와 고막체온계의 측정치와 측정시 경험에 관한 비교연구)

  • Min Soon
    • The Journal of Korean Academic Society of Nursing Education
    • /
    • v.4 no.1
    • /
    • pp.95-106
    • /
    • 1998
  • This study aims to provide a better nursing service in the dimension of economizing time and human efforts. This is to present some basic knowledge necessary to improving a nursing quality in measuring body temperature by analyzing the contents that the objects experienced at the time of measure with tympanic thermometer and mercury thermometer Subjects of the survey consisted of 71 college students, 47 adult patients and 40 pediatric patients. The results were as follows : 1. The oral temperature by mercury thermometer and tympanic thermometer with oral mode was : $36.83^{\circ}C$ by mercury thermometer and $37.02^{\circ}C$ by tympanic thermometer in college students : it showed an significant difference statistically. 2. Comparsion between oral mode and rectal mode by tympanic thermometer in college students : $37.03^{\circ}C$ by oral mode and $37.55^{\circ}C$ by rectal mode and this defference was significant statistically 3. Comparision between rectal temperature by mercury thermometer and rectal mode of tympanic thermometer : $37.54^{\circ}C$ by mercury thermometer and $37.73^{\circ}C$ by tympanic thermometer, it showed a significant difference statistically. 4. Comparision between oral temperature by mercury thermometer and oral mode of tympanic thermometer of the pediatric patients : $36.51^{\circ}C$ by mercury temperature and $36.94^{\circ}C$ by tympanic thermometer, it showed a significant difference statistically. 5. Comparision between oral body temperature by mercury thermometer and oral mode of tympanic thermometer of the adult patients : $36.56^{\circ}C$ by mercury thermometer and $36.90^{\circ}C$ by tympanic thermometer, it did not show statistically any difference. 6. At the measure by mercury thermometer this data can classified In three main categorise : their feeling to a thermometer, thermometer itself and aspect physical of the clients. It is considered that an subjective experience to tympanic thermometer was more positive.

  • PDF