• Title/Summary/Keyword: resistance changes

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An Ananlysis on the Clothing Pracices between Seoul and yanbian -Focusing on the clothing weight- (서울.연변간 착의실태 조사분석 -착의량을 중심으로-)

  • Oh, Soon;Lee, Won-Ja
    • Journal of the Korean Society of Clothing and Textiles
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    • v.23 no.7
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    • pp.1019-1029
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    • 1999
  • In order to find out the influences upon not only the thermal resistance of human body but also the clothing action and the clothing weight which are caused by the differences in the thermal living conditions by using air conditioner and so on to adapt themselves to the changes of their residential environment according to the changes of seasons we investigated the clothing practices upon the male and female students in Seoul and Korean male and female students in Yanbian who are estimated to have different thermal living conditions in spite that they are same folk as well as living in the same age. 1. The total clothing weight of body surface erea was increased in order of summer autumn spring and winter seasons and by seasons the changes of the clothing weight were found in both areas, In Seoul the changes of upper outwear clothing weight were found on both sexes but in Yanbian the changes of underwear weight were found on both sexes. And the underwear weight of both sexes in Seoul was lighter than that of both sexes in Yanbian. 2. Those in Seoul tended to fell colder in winter and hotter in summer than those in Yanbian on account that the formers are more sensitive of thermal conditions than the latters. 3. Comparing clo-value claculated by the fomula of with the Winshlow's clo-value those in Yanbian had higher thermal resistance than those in Seoul. Consequently those in Seoul adapted thermselves to the seasons by controling the upper outwear weight but those in Yanbian did it with underwear weight, The male and female students in Seoul tended to feel colder in winter and hotter in summer than hose in Yanbian because the thermal sense of the former is more sensitive than that of the latter.

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Comparison of Various Methods for Estrus Stage Determination in Bitch (개의 발정 진단 방법에 따른 효율 비교)

  • Ko, Young-Jin;Kang, Eun-Ju;Lee, Sung-Lim
    • Journal of Embryo Transfer
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    • v.24 no.3
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    • pp.131-137
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    • 2009
  • In dogs, correct diagnosis of estrus is important and the exact time of ovulation can be determined by variouse methods. Vaginal cytology has commonly used in conjunction with the physical examination, clinical history, vaginoscopy, and hormonal assays to determine the stage of the reproductive cycle. This study was therefore investigated the effectiveness of direct ovulation detector designed by changes of electrical resistance in vaginal mucus following different estrus cycles with several methods; vaginal cytology, concentration of plasma estrogen and progesterone, and direct examination by laparotomy. A total of 12 bitches was selected for the study and observed estrus signs. The bitches were evaluated clinical sign (vulvar swelling and bleeding), cytological examination (keratocyte and RBC), electrical resistance, plasma estrogen and progesterone concentration for estrus assessment. Accuracy of ovulation detection by vaginal cytology was significantly (p<0.05) lower than those by electrical resistance and plasma progesterone concentration, based on the confirmation by laparotomy. Vaginal smear is not confidential method compared to detection of electrical resistance and plasma progesterone concentration at ovulation. Although the value of electrical resistance was varied at the same points of estrus in individuals, ovulation was occurred at the first day which shown the peak of electrical resistance and mating time was third day after peak. In conclusion, ovulation detector designed by changes of electrical resistance is an effective and economic instrument for predicting estrus and ovulation in bitches.

Nanomechanical properties and wear resistance of dental restorative materials

  • Karimzadeh, A.;Ayatollahi, Majid R.;Nikkhooyifar, M.;Bushroa, A.R.
    • Structural Engineering and Mechanics
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    • v.64 no.6
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    • pp.819-826
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    • 2017
  • The effects of thermocycling procedure and material shade on the mechanical properties and wear resistance of resin-based dental restorative materials are investigated. The modulus of elasticity, hardness, plasticity index and wear resistance are determined for the conventional composite, the nanohybrid composite and the nanofilled dental composites. Disc-shape samples are prepared from each material to investigate the effects of thermocycling procedure on the mechanical properties and wear resistance of different types of dental restorative materials. In this respect, a group of samples is thermocycled and the other group is stored in ambient conditions. Then nano-indentation and nano-scratch tests are performed on the samples to measure their mechanical properties and wear resistance. Results show that the A1E shade of the dental nanocomposite possesses higher modulus of elasticity and hardness values compared to the two other shades. According to the experimental results, the mean values for the modulus of elasticity and hardness of the A1E shade of the nanocomposite are 13.71 GPa and 1.08 GPa, respectively. The modulus of elasticity and hardness of the conventional dental composite increase around 30 percent in the oral environment due to the moisture and temperature changes. The wear resistance of the dental composites is also significantly affected by moisture and temperature changes in the oral conditions. It is observed that thermocycling has no significant effect on the hardness, plasticity index and wear resistance of the nanohybrid composite and the nanocomposite dental materials.

The Diffusion Period and Productivity of Smartwork by Business Simulation (비즈니스 시뮬레이션으로 살펴본 스마트워크의 확산 기간과 생산성 연구)

  • Jung, Byoungho
    • Journal of Korea Society of Digital Industry and Information Management
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    • v.17 no.1
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    • pp.57-73
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    • 2021
  • The purpose of this study is to analyze the diffusion period and productivity of smartwork in an organization. Firms are increasingly interested in smartwork for non contact work and working from home because of the corona 19. The smartwork is a new technology that changes face-to-face work in an organization. It helps the work of individuals and organizations regardless of time and place. The theoretical background describes the complexity, system thinking, diffusion theory, smart work, organizational resistance, and productivity. This study analyzes the diffusion period and productivity of smart work through business simulation techniques. A simulation study progresses four stages. There are problem definition, hypothesis establishment and causal loop diagram, model construction and verification, and policy evaluation. The simulation models contain an individual's resistance variables organizational investment and leadership variables related to the operation of smartwork. The organizational investment variables include organizational culture, legal system, implement systems and technology investment. The individual resistance variables include cognitive, attitude, structure and technological resistance. The leadership includes leadership interest variables and performance linkage variables. The simulation executed the changes of a people number adopting smart work and the organizational productivity monthly. As a result of the simulation, many organization members have accepted the smart work innovation after 20 months. The organizational productivity through smart work showed very high value after 16 months. In scenario analysis, the individuals' awareness and attitude resistance showed very important variables to productivity and a personal change of smart work adoption. Meanwhile, The organizational investment showed that the high driving-force increased not productivity and the low driving-force showed decreased low productivity. Also, leadership variables showed a powerful driver for changing smart work productivity. The implication of the study has suggested extending complexity, diffusion theory and organization resistance theory based on simulation methods.

Evaluation of high plasticity clay stabilization methods for resisting the environmental changes

  • Taleb, Talal;Unsever, Yesim S.
    • Geomechanics and Engineering
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    • v.30 no.5
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    • pp.461-469
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    • 2022
  • One of the most important factors that should be considered for using any ground improvement technique is the stability of stabilized soil and the durability of the provided solution for getting the required engineering properties. Generally, most of the earth structures that are constructed on clayey soils are exposing movements due to the long periods of drying or wetting cycles. Over time, environmental changes may result in swells or settlements for these structures. In order to mitigate this problem, this research has been performed on mixtures of high plasticity clay with traditional additives such as lime, cement and non-traditional additives such as polypropylene fiber. The purpose of the research is to assess the most appropriate ground improvement technique by using commercially available additives for resisting the developed desiccation cracks during the drying process and resisting the volume changes that may result during wet/dry cycles as an attempt to simulate the changes of environmental conditions. The results show that the fiber-reinforced samples have the lowest volumetric deformation in comparision with cement and lime stabilized samples, and the optimum fiber content is identified as 0.38%. In addition, the desiccation cracks were not visible on the samples' surface for both unreinforced and chemically stabilized samples. Regarding cracks resistance resulting from the desiccation process, it is observed, that the resistance is connected with the fiber content and increases with the increase of the fiber inclusion, and the optimum content is between 1% and 1.5%.

An Experimental Study on the Fire Resistance Performace of Intumescent Coating System by Environmental Testing Procedure (환경시험방법에 의한 내화도료의 내화성능에 관한 실험적 연구)

  • Park, Soo-Young;Sung, Si-Chang;Choi, Dong-Ho;Kim, Dae-Hoi;Lee, Sea-Hyun;Lee, Jong-Chan
    • Proceedings of the Korea Institute of Fire Science and Engineering Conference
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    • 2008.04a
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    • pp.69-72
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    • 2008
  • This study is designed to understand changes in fire resistance performance of intumescent coating system through follow-up tests on temperature of unexposed surface for the domestic intumescent coating system by environmental testing procedure.

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Shrinkproof Effect and Property of Shrinkproof-Finished Wool Knit

  • Park Myung-Ja;Kwak Soo-Kyoung
    • The International Journal of Costume Culture
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    • v.7 no.2
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    • pp.103-111
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    • 2004
  • The shrinkproof-finished wool fibers treated with resin coating and chlorination methods were used to find out an optimal shrinkproof finishing method keeping the quality properties of wool fabric to manufacturers. Shrinkage during repeated washing, electrostatic propensity, thermal resistance and pilling propensity of shrinkproof-finished wool knits, and analysis of finishing methods were measured. Upon the results from the surface examination of shrinkproof-finished wool fibers, the patterns of scale layer and degree of scale removal were subject to change according to the finishing processes. The shrink resistance was significantly enhanced on repeated washing of shrinkproof-finished knits, especially, chlorinated wool. Addition of strong physical force and alkali detergent applied in this washing experiment brought about superior effects with the low shrinkage rate although it was very severe washing conditions for wool fabrics. The results from the washing experiment implies that shrinkproof-finished knitted fabrics can be machine washed at individual households with other ordinary laundry. There was some changes and variation found in thermal resistance, electrostatic propensity, and pilling, however, it seems to be minor within standard limits. Therefore, shrinkproof-finished knitted fabrics did not bring serious changes to other physical properties comparing with original wool, which helps consumers handle wool knitted clothes more conveniently.

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Broad and stage-based sensing function of HCFRP sensors

  • Wu, Z.S.;Yang, C.Q.
    • Smart Structures and Systems
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    • v.3 no.2
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    • pp.133-146
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    • 2007
  • This paper addresses a new type of broad and stage-based hybrid carbon fiber reinforced polymer (HCFRP) sensor that is suitable for the sensing of infrastructures. The HCFRP sensors, a type of composite sensor, are fabricated with three types of carbon tows of different strength and moduli. For all of the specimens, the active materials are carbon tows by virtue of their electrical conductivity and piezoresistivity. The measurement principles are based on the micro- and macro-fractures of different types of carbon tows. A series of experiments are carried out to investigate the sensing performances of the HCFRP sensors. The main variables include the stack order and volume fractions of different types of carbon tows. It is shown that the change in electrical resistance is in direct proportion to the strain/load in low strain ranges. However, the fractional change in electrical resistance (${\Delta}R/R_0$) is smaller than 2% prior to the macrofractures of carbon tows. In order to improve the resistance changes, measures are taken that can enhance the values of ${\Delta}R/R_0$ by more than 2 times during low strain ranges. In high strain ranges, the electrical resistance changes markedly with strain/load in a step-wise manner due to the gradual ruptures of different types of carbon tows at different strain amplitudes. The values of ${\Delta}R/R_0$ due to the fracture of high modulus carbon tows are larger than 36%. Thus, it is demonstrated that the HCFRP sensors have a broad and stage-based sensing capability.

Shrink-Resist Effects and Properties of the Knitted Fabrics from Wool/Acrylic Fiber Blends (양모/아크릴 혼방사 편성물의 방축 효과 및 물성에 관한 연구)

  • Lee Youn-Hee;Kwak Soo Kyoung;Park Myung-Ja
    • The Research Journal of the Costume Culture
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    • v.12 no.6 s.53
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    • pp.945-952
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    • 2004
  • Shrink-resist effects and properties of the knitted fabrics from wool/acrylic(W/A) fiber blends were determined to find out an optimal blending ratio keeping the quality properties of wool products. The test fabrics were knitted by a weft knitting machine with all needle knitting structure ($0{\times}0$ rib) under the same knitting conditions with five different types of yarns: $W100\%,\;A100\%$, and W/A blended yarns(70/30, 50/50, 30/70). Shrinkage during repeated washing, electrostatic propensity, thermal resistance and pilling propensity of W/A knits. The shrink resistance was significantly enhanced on repeated washing of W/A knits, especially, over $50\%$ acrylic blended knits. Addition of strong physical force and alkali detergent applied in this washing experiment brought about superior effects with the low shrinkage rate although it was very severe washing conditions for wool fabrics. The results from the washing experiment implies that W/A blend knits can be machine washed at individual households with other ordinary laundry. There was some changes and variation found in thermal resistance, electrostatic propensity, and pilling. W/A 50/50 blended knits did not bring serious changes to other physical properties comparing with original wool, which helps consumers care wool knitted clothes more conveniently.

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A Comparison of Various Exercises for Scapular Stabilization (견갑골 안정화를 위한 다양한 운동의 비교연구)

  • Kim, Myungjin;Lee, Yujin;Kim, Jihyuk;Bae, Wonsik
    • Journal of The Korean Society of Integrative Medicine
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    • v.1 no.3
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    • pp.51-62
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    • 2013
  • PURPOSE : This study of 20 healthy male subjects by applying various scapular stabilization exercise to compared Serratus anterior and lower trapezius is change in ultrasound images. METHOD : Thirty healthy subjects voluntarily participated in this study. Ultrasound imaging was recorded from the increasing the activity of Serratus anterior(SA) and Lower trapezius(LT) muscles using Push-up plus, Wall slide, Scapular plane shoulder elevation with resistance exercise. Thickness changes in the Serratus anterior(SA) and lower trapezius(LT) muscles between the relaxed and contracted states in the each exercises. To identify statistical significance, one-way ANOVA with repeated measures was used with the significance level of .05. RESULT : The results of this study were as follows : 1) There were statistically significant difference in thickness changes in the Serratus anterior(SA) and lower trapezius(LT) muscles between the relaxed and contracted states in the each exercises. 2) The Scapular plane shoulder elevation with resistance is more effective to Strengthening in the scapular stabilization muscles than Push up-plus and Wall slide. CONCLUSION : The Scapular plane shoulder elevation with resistance may be used to effectively that patient with various shoulder pain.