• Title/Summary/Keyword: Tightness

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ON SPACES WHICH HAVE COUNTABLE TIGHTNESS AND RELATED SPACES

  • Hong, Woo-Chorl
    • Honam Mathematical Journal
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    • v.34 no.2
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    • pp.199-208
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    • 2012
  • In this paper, we study some properties of spaces having countable tightness and spaces having weakly countable tightness. We obtain some necessary and sufficient conditions for a space to have countable tightness. And we introduce a new concept of weakly countable tightness which is a generalization of countable tightness and show some properties of spaces having weakly countable tightness.

Time Serial Change of Proximal Contact Tightness after Crown Restoration (인공치관 수복 후 인접면 접촉강도의 경시적 변화)

  • Na, Hyun-Joon;Kang, Dong-Wan;Oh, Sang-Ho
    • Journal of Dental Rehabilitation and Applied Science
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    • v.26 no.2
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    • pp.197-204
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    • 2010
  • The purpose of the study was to observe the time serial changes in proximal contact tightness after single crown restoration. Initial proximal contact tightness before crown preparation and after prosthesis restoration were measured repeatedly in 12 subjects. In consequence proximal contact tightness of temporary setting on prosthesis was bigger than contact tightness before initial preparation, contact tightness of the prostheses of 1-2 weeks after the setting was similar to that before the preparation, tightness of 2-4 weeks after the setting showed little change and maintained constant contact tightness.

Relationship of Ankle Dorsiflexion and Gastrocnemius Tightness and Posterior Talar Glide

  • Kang, Min Hyeok
    • Journal of International Academy of Physical Therapy Research
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    • v.9 no.3
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    • pp.1517-1520
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    • 2018
  • It has been reported that gastrocnemius tightness and posterior talar glide are crucial factors influencing ankle dorsiflexion. However, the relationship of ankle dorsiflexion and these factors is not identified in previous studies. The purpose of this study was to identify the relationship of ankle dorsiflexion passive range of motion and gastrocnemius tightness and posterior talar glide. Twenty-five male subjects participated in this study. Bilateral weight-bearing ankle dorsiflexion passive range of motion and amount posterior talar glide of participants were measured using an inclinometer. Change in myotendinous junction of medial gastrocnemius was measured using ultrasonography to identify gastrocnemius tightness. Pearson product moment correlations were performed to examine correlations between ankle dorsiflexion passive range of motion and gastrocnemius tightness and posterior talar glide. Present findings revealed significant correlation between ankle dorsiflexion passive range of motion and gastrocnemius tightness (p=0.017, r=0.336). Also, ankle dorsiflexion passive range of motion was correlated with posterior talar glide (p=0.001, r=0.470). The present findings provide experimental evidence for factors influencing weight-bearing ankle dorsiflexion.

A Study on the adaptedness of brassiere underbust length (브래지어 총(總) 길이 적합성(適合性)에 관(關)한 연구(硏究)(II))

  • Park, You-Shin;Choi, Young-Soon
    • Journal of Fashion Business
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    • v.10 no.1
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    • pp.31-40
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    • 2006
  • We studied relation between the clothing pressure applied by types of brassiere, postures, feeling of tightness. The main results were summerized as follows; 1. The research subjects of this study were 9 who rate of body fat was borderline and degree of fatness was normal. As a result of clothing pressure, the most prefered value was $36.86g/cm^2$ on sensor 2 in standing position and the next was $34.76g/cm^2$ on sitting position. Furthermore, The maximum value of sensor 2 was $59.08g/cm^2$ (in standing), $57.93g/cm^2$ (in sitting). On the other hand, The average clothing pressure of bra C type was $23.67g/cm^2$ 2. The study of feeling of tightness applied by bra type was high in order of C

Developing the Construction Guideline for ZEB Based on Air-tightness of Public Buildings in Korea (국내 비주거용 건물의 기밀성능 측정 결과를 통한 기밀 시공 가이드라인 개발)

  • Bae, Minjung;Choi, Gyeongseok
    • Land and Housing Review
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    • v.11 no.3
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    • pp.69-74
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    • 2020
  • Since the design Standard for Energy Conservation in Building was implemented in 2008 for the first time, building elements such as window and door should satisfy the minimum criteria to apply for a building. Though its regulation does not cover the whole building yet, recent demand to reduce energy consumption in building sector grows rapidly year by year and also draws a lot of interest to ensure the whole building level. For example, a Zero energy building, one of low-energy buildings, requires a customized solution to resolve the air leakage issue to meet the standards in achieving the high level of air tightness. In this study, six non-residential buildings were tested by fan pressurization method to observe the air tightness of whole building to suggest the construction guideline for air tightness of low-energy building. Five out of six tested buildings showed 0.27 to 1.16 h-1 of number of air changes except one community center. These buildings were carefully constructed not only for building planning but also for parts where there was a concern of air leakage, thereby securing high levels of air-tightness. The construction skills were developed as a checklist to manage and supervise the construction site. It is our suggestion to use this checklist at construction sites for ZEB with the high level of air-tightness.

A Study on the Liquid Tightness Design on LNG Tank Incorporating Cryogenic Temperature-induced Stresses (LNG 탱크의 극저온 온도응력을 고려한 수밀성 설계방법 비교 연구)

  • 전세진;김영진;정철헌;진병무;김성운
    • Proceedings of the Korea Concrete Institute Conference
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    • 2003.11a
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    • pp.128-131
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    • 2003
  • In a design of LNG storage tank, one of the major loading conditions that significantly affects liquid tightness of the outer concrete wall is the cryogenic temperature of LNG under the emergency condition of LNG leakage. Proposed in this study are the more consistent procedures to ensure the liquid tightness of LNG tank focusing on the design of prestressing tendon. It is expected that the proposed schemes lead to a more effective serviceability design of LNG tank that satisfies various requirements for the liquid tightness in an efficient manner.

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The Concepts of Tightness for Fuzzy Set Valued Random Variables

  • Kim, Yun-Kyong
    • International Journal of Fuzzy Logic and Intelligent Systems
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    • v.9 no.2
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    • pp.147-153
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    • 2009
  • In this paper, we introduce several concepts of tightness for a sequence of random variables taking values in the space of normal and upper-semicontinuous fuzzy sets with compact support in $R^p$ and give some characterizations of their concepts. Also, counter-examples for the relationships between the concepts of tightness are given.

A Study on Estimation of Air Tightness for Train (철도차량의 공기압 기밀도 평가에 관한 연구)

  • Nam, Seong-won
    • Journal of the Korean Society for Railway
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    • v.19 no.5
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    • pp.576-584
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    • 2016
  • In this study, we measured the air tightness of a train using pressure variation in tunnels. To estimate the air tightness of a train is essential to comprehend the pressure variation of the cabin because air tightness is strongly related with ear discomfort. If we can determine the air tightness, we can predict the pressure variation of the cabin. Also, ear discomfort is a problem that can be caused in a high speed train, as well as in Korea's Great Train Express. In this study, we compared the various international standards for ear discomfort and estimated the air tightness of each vehicle based on experimental data obtained using the ITX, KTX and KTX-sancheon(honam) vehicles. The internal pressure variation of the trains is numerically calculated using the air tightness value. The results are good compared to the experimental results. Instead of flap type ventilation, in the future, continuous ventilation equipment will be needed for speed-up.

A NOTE ON SPACES WHICH HAVE COUNTABLE TIGHTNESS

  • Hong, Woo-Chorl
    • Communications of the Korean Mathematical Society
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    • v.26 no.2
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    • pp.297-304
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    • 2011
  • In this paper, we introduce closure operators [${\cdot}$]c and [${\cdot}$]a on a space and study some relations among [${\cdot}$]c, [${\cdot}$]a and countable tightness. We introduce the concepts of a strongly sequentially closed set and a strongly sequentially open set and show that a space X has countable tightness if and only if every strongly sequentially closed set is closed if and only if every strongly sequentially open set is open. Finally we find a generalization of the weak Fr$\'{e}$chet-Urysohn property which is equivalent to countable tightness.