• 제목/요약/키워드: Tightness

검색결과 438건 처리시간 0.023초

Thermal Resistance and Condensation in the Light-frame Timber Wall Structures with Various Composition of Insulation Layers

  • Jang, Sang Sik;Lee, Hyoung Woo
    • Journal of the Korean Wood Science and Technology
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    • 제47권4호
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    • pp.533-542
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    • 2019
  • As energy costs increase, more people has become interested on energy efficiency and savings in residential buildings. The two main subjects related to energy in residential buildings are insulation and condensation. There are two approaches to prevent condensation; increasing air tightness and maintaining the temperature inside of the wall structure over the dew point, which is in turn related to insulation. Even though the Korean government has highlighted the importance of energy efficiency for residential housings, and in spite of the customers' demands, the timber construction industry is still using conventional light-frame construction without even trying to improve energy efficiency. In this study, various types and combinations of wall structures were tested under cold outdoor and warm indoor temperatures to analyse the temperature gradients and to determine the possible sites of condensation in the wall structures. In addition to the experimental tests, three theoretical models were developed and their estimations of temperature change through the wall structure were compared with the actual measurements to evaluate accuracy of the models. The results of the three models agree relatively well with the experimental values, indicating that they can be used to estimate temperature changes in wall structures. The theoretical analysis of different insulation layers' combinations show that condensation may occur within the mid-layer in the conventional light-frame wall structures for any combination of inner-, mid-, and outer-layers of insulation. Therefore, it can be concluded that the addition of an inner and outer insulation layer or increasing the thickness of insulation may not be adequate to prevent condensation in the wall structure without preventing penetration of warm moist air into the wall structure.

패시브 공동주택 계획을 위한 설계 중점항목 및 관련 기준 연구 (A Study of Critical Items and Related Standards on Designing for Passive Apartments)

  • 이명주
    • 대한건축학회논문집:계획계
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    • 제34권7호
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    • pp.21-29
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    • 2018
  • This study aimed to find and suggest the purpose of future plans, critical items on designing and Related standards to amend construction standards for domestic energy saving and environmentally friendly housings. It would also activate and increase the supplies of passive house minimizing the problems on current apartment housings in winter and reducing heating energy which brings fine dust pollution. After defining the standard model of Korean apartment housings(reference model), this study calculated the amount of heating energy demand per unit area annually as applying the yearly changed standards from 2008 to 2017 to existing standard model. It turned out that applying 2017 construction standards of energy saving and eco-friendly housings to reference model has saved up to 75% of heating energy demand comparing to the one applied 2008's. However, it still could not solve the fundamental problems such as winter fungus, condensation, freezing, freeze and burst, and insulation weakness space, and could not be free from fine dust particles. To solve them, this study suggested improved standards adding critical items on design related to outside insulation, cut off the heat-bridge, enforce air-tightness and heat change efficiency on heat recovery ventilator. As a result, it has reduced more than 10% of heat demand from 2017. It would be more than 90% of savings from 2008 if we make the amount of heat loss be zero on heat bridge on designing stage in the future.

MRT(Moisture Responded Transformable)섬유의 의료용 압박소매 적용에 관한 연구 (A Study on the Application of Medical Compression Arm Sleeves Using a MRT(Moisture Responded Transformable) Fibers)

  • 조대현;정태두;박은희;박영미
    • 한국염색가공학회지
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    • 제33권2호
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    • pp.87-95
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    • 2021
  • In this study, the application of a medical compression sleeve of Moisture Responded Transformable(MRT) fibers to the treatment of lymphedema after surgery in breast cancer patients was investigated. MRT fibers were manufactured with PET and Nylon6 bi-component cross-section yarns, and compression sleeves of sleeves 1, 2, 3, and 4 were knitted in order of size, and then the physical properties and clinical tests were evaluated. As a result, the pressure of compression sleeve in wrinkle was the lowest in sleeve 1 with 3.81 kPa, and the highest in sleeve 4 with 5.22 kPa. Elastic recovery rate is that all parts except the top of the sleeve 1 exhibited 100%. The air permeability was good at 12.1 ~ 16.1 cm3/cm2/sec, and peeling was also comparatively excellent as grade 3. In addition, the weight of the compression sleeves 1, 2, and 3 decreased as 18.3 ~ 23.0 g/m2 depend on size, while the compared sample was heavier with 17.39 ~ 32.61 g/m2. In lymphoscintigraphy test, it was confirmed that the function of remaining lymph node was good in all patients. Although there were no differences between samples in skin irritation and tightness in wearing comfort, the manufactured sleeves showed better fit, lightness, fashion and breathability than the comparable sleeves.

팬츠 실루엣에 따른 실제착의와 가상착의의 유사도 비교 연구 (A Study on the Comparison of Fit Similarity Between the Actual and Virtual Clothing According to the Pants Silhouette)

  • 원윤혜;이정란
    • 한국의류산업학회지
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    • 제23권6호
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    • pp.826-835
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    • 2021
  • The purpose of this study was to compare the similarity between actual and virtual pants using a virtual 3D CLO program. A subject corresponding to the average size of a women in her twenties was selected and an avatar with the same specifications was produced. Silhouettes of the pants were classified into trousers, slacks, and wide pants and images of actual and virtual pants were evaluated from the front, side, and back. The results were as follows: Overall, the resemblance of the trousers was evaluated higher than that of other pants. The average similarity of trousers was 4.20 at the front, 3.98 at the side, and 4.17 at the back, which was much like the actual clothing. In contrast, that of the slacks was 3.62, 3.73, and 3.79 and of the wide pants was 3.81, 3.53, and 3.97. The similarity between the actual and virtual clothing was relatively well reproduced when the shape of the pants was like the silhouette of the human body. However, if the pants were tight or loose, virtual fits failed to display the wrinkles caused by the tightness or the excessive slack. The virtual fit showed fewer wrinkles and did not depict the location and the shape of hemlines as accurately as the actual fit, although virtual fits adequately displayed the baseline and dart on the pants.

Research on sealing ability of granular bentonite material after 10.5 years of engineered barrier experiment

  • Ni, Hongyang;Liu, Jiangfeng;Pu, Hai;Zhang, Guimin;Chen, Xu;Skoczylas, Frederic
    • Geomechanics and Engineering
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    • 제27권6호
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    • pp.583-594
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    • 2021
  • The gas permeability behavior of unsaturated bentonite-based materials is of major importance for ensuring effective sealing of high-level radwaste repositories. This study investigated this by taking a sample of Granular Bentonite Material (GBM) at the end of the Engineered Barrier Emplacement (EB) experiment in the Opalinus Clay, placing it under different humidity conditions until it achieved equilibration, and testing the change in the gas permeability under loading and unloading. Environmental humidity is shown to have a significant effect on the water content, saturation, porosity and dry density of GBM and to affect its gas permeability. Higher sensitivity to confining pressure is exhibited by samples equilibrated at higher relative humidity (RH). It should be noted that for the sample at RH=98%, when the confining pressure is raised from 1 MPa to 6 MPa, gas permeability can be reduced from 10-16 m2 to 10-19 m2, which is close to the requirements of gas tightness. Due to higher water content and easier compressibility, samples equilibrated under higher RH show greater irreversibility during the loading and unloading process. The effective gas permeability of highly saturated samples can be increased by 2-3 orders of magnitude after 105℃ drying. In addition, cracks possibly occurred during the dehydration and drying process will become the main channel for gas migration, which will greatly affect the sealing performance of GBM.

코로나-19 사회적 사태를 경험한 65세 이상 노인들의 정서적 변화에 대한 현상학적 연구 (A Phenomenological Study on the Emotional Change of the Elderly Aged 65 and older who Experienced COVID-19 Social Situation)

  • 이나윤;강진호
    • 한국엔터테인먼트산업학회논문지
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    • 제14권6호
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    • pp.171-179
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    • 2020
  • 본 연구는 코로나-19 사회적 사태를 경험한 노인들의 정서적 변화를 알아보기 위해 J 시에 거주 중인 65세 이상 노인 6명을 대상으로 진행되었다. 연구 결과 1개의 구성요소와 4개의 하위 구성요소가 도출되었으며, 구성요소는 정서적 변화로 노인들은 코로나-19를 경험하면서 확산에 대한 불안함, 확진자 및 사망자 증가 소식에 대한 두려움, 외출 자제 등으로 인한 우울과 답답함, 종식에 대한 기대감을 경험하였다. '기술적 방역'을 아무리 열심히 해도 '심리적 방역'이 없으면 노인들의 불안은 커질 수밖에 없다. 본 연구에서는 코로나-19로 인한 두려움의 확산을 막기 위해 정확한 정보를 제공하고 '기술적 방역'뿐 아니라 노인들에게 '심리적 방역'인 정서적 지원 프로그램 등을 제공하여 노인들이 경험하는 부정적 정서에 대한 중재가 필요할 것으로 사료된다.

가변추력 핀틀 분사기의 고압 분무 및 연소특성 (High Pressure Spray and Combustion Characteristics of Throttleable Pintle Injector)

  • 김대환;허수범;김인호;황동현;강철웅;이신우;안규복;윤영빈
    • 한국추진공학회지
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    • 제26권2호
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    • pp.60-71
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    • 2022
  • 최근 발사체 시장의 저비용·재사용 발사체 개발 움직임은 여러 방향으로 세분화되고 있으며, 그중 하나는 가변추력 엔진 개발이다. 또한, 우주 선진국들은 그 청정성 때문에 차세대 우주발사체 추진제로 메탄을 선택하여 연구개발을 진행하고 있다. 본 연구에서는 이에 기체메탄과 액체산소를 추진제로 사용하는 가변추력 핀틀 분사기를 개발했고, 고압 수류시험과 고압 연소시험을 통해 분무 및 연소 특성을 분석했다. 개발된 가변추력 핀틀 분사기는 이중 슬리브 구조를 가졌으며, 반복적인 상압수류, 고압수류 및 연소시험에서 기밀성과 작동성 등에 문제없음을 확인할 수 있었다. 그러나 목표했던 추력 조절 범위는 연소시험에서 달성치 못하는 등 설계상의 문제점이 발견되어 보완이 필요하다.

액체 로켓 엔진 스태틱 실 개발 (Development of Static Seal for a Liquid Rocket Engine)

  • 전성민;윤석환;정태검
    • 항공우주시스템공학회지
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    • 제16권4호
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    • pp.53-59
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    • 2022
  • 액체 로켓 엔진의 연소기, 터보펌프, 가스발생기, 밸브 등 주요 구성품 조립 부위에는 고압의 고온 가스와 극저온 유체의 기밀을 위해 스태틱 실이 사용된다. 스태틱 실은 조립 부위의 상대적 움직임이 없는 기밀 부위에 적용되는데, 극저온 및 고온 환경에서의 열팽창과 수축은 조립부에서 원치 않는 누설을 야기할 수 있기에 효과적인 스태틱 실 설계가 필수적이다. 조립성 개선을 위하여 비정렬 조립이 가능한 구면 플랜지가 체결부에 사용되는데, 구면 플랜지의 회전이 가능하도록 스태틱 실 역시 기능이 추가된 다. 본 연구에서는 스태틱 실 적용 주요 부위의 모사 플랜지 시험기를 제작하여 구조 해석과 함께 기밀시험을 수행하여 설계된 스태틱 실의 구조 건전성을 확인하였다.

억울 경험의 과정과 특성에 대한 실증적 연구 (An Empirical Research on the 'Eogul')

  • 서신화 ;허태균 ;한민
    • 한국심리학회지 : 문화 및 사회문제
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    • 제22권4호
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    • pp.643-674
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    • 2016
  • 한국 사람들에게 억울은 자신이 처한 상황 또는 마음상태를 묘사하는 유용한 수단이자 화병에서 자살에 이르기까지 한국인의 정신건강에 부정적인 영향을 미치는 중요한 원인으로 여겨지고 있음에도 불구하고 한국 사람들이 어떤 경우에 억울함을 느끼며 어떤 방식으로 이를 해소하는지, 억울하다는 것을 어떠한 의미로 받아들이는지에 대한 실질적인 연구는 부족하다. 이에 본 연구는 억울에 대한 이해를 보다 명확히 하기위해 2개의 연구를 진행하였다. 연구 1에서는 한국인들이 억울이라는 말을 사용하여 표현하는 상황과 억울을 경험하는 전반적인 과정을 조사하여 억울 경험의 구조와 특성을 확인하였다. 그 결과 억울함은 자신의 일을 주관적으로 부당하다고 인식하고 여기에 부정적인 정서가 따름으로써 경험되는 보편적인 과정을 거쳐 발생하였다. 하지만 어떠한 상황을 부당하다고 여기는지 그리고 억울을 어떻게 표현하며 해소하는지는 각 문화권마다 다르게 나타날 수 있다. 따라서 연구 2에서 억울 경험 과정에 연관된 문화적 맥락(주체성-대상성-자율성 자기관, 개인주의-집단주의 가치관, 느슨한-경직된 체계특성, 권위주의 성향)이 억울에 미치는 영향을 실증적으로 검증하고 이상의 결과를 종합하여 억울의 특성에 대해 논의하였다.

Comparative Effects of Novel Modified Sleeper and Cross-body Stretching on Scapular Anterior Tilting and Shoulder Internal Rotation in Subjects With Anterior Tilted Scapular and Shoulder Internal Rotation Deficits

  • Yeonghun Han;Chung-hwi Yi;Woochol Joseph Choi;Oh-yun Kwon
    • 한국전문물리치료학회지
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    • 제30권1호
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    • pp.59-67
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    • 2023
  • Background: Posterior capsule tightness (PCT), commonly seen in overhead athletes, is a soft tissue adaptation that is also noted in non-throwers. PCT is associated with scapular and humeral kinematic alterations, significant restriction of shoulder internal rotation (IR) range of motion (ROM), and significant scapular anterior tilting. Sleeper and cross-body stretches (CBS) are suggested for PCT and IR deficits, and have been modified since introduction. A novel modified sleeper stretch (NMSS) was designed in this study to prevent the risk of anterior translation of the humeral head. Though the effects of posterior shoulder stretching exercise have been widely studies, to the best of our knowledge, no previous studies have investigated the effectiveness of posterior shoulder exercises in decreasing scapular anterior tilting. Objects: To compare the immediate effects of two posterior shoulder stretching exercises (NMSS and CBS) on scapular anterior tilting and shoulder IR ROM. Methods: Thirty-two subjects with anteriorly tilted scapula and IR deficits [mean age: 24.3 ± 2.5 years; 15 males and 17 females] participated in this study. Subjects were randomly assigned to either the NMSS or CBS groups. Scapular anterior tilting (at rest and at shoulder 60° active IR) and shoulder IR ROM were measured before and immediately after intervention. Results: Scapular anterior tilting significantly decreased, while the shoulder IR ROM significantly increased in both groups. However, there was no significant group-by-time interaction effect or significant difference between the groups. Conclusion: Both stretching exercises were effective in restoring shoulder IR ROM and decreasing scapular anterior tilting.