• Title/Summary/Keyword: age of air

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Comparison of old-old aged women's pants basic pattern using 3D data (3차원 계측데이터를 활용한 고령 여성의 팬츠 원형 비교)

  • Cha, Su-Joung
    • The Research Journal of the Costume Culture
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    • v.26 no.3
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    • pp.360-376
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    • 2018
  • The purpose of this study was to make a pants pattern suitable for women 70 to 85 years of age, then analyze that- pattern's shape, size, appearance, fit, allowance and air gap. Participants made the pattern using 3D simulation program DC Suite version 5.1. The results suggest a design method suitable for the lower-body shapes of elderly women. In external appearance, the A-type earned the highest evaluation in all items except the allowance of the back waist and back hip. The L type earned the highest evaluation in the allowance of back waist and hips. The A-type's, back waist appeared set at an angle that did not match the body shape of an old-old aged woman in the center-back-line setting. Therefore, the pattern method of A-type combined with L-type's method of center back, produces an excellent pants pattern. Evaluation of the air gaps among patterns revealed that; the A-type showed the largest air gap in waist and hip circumference and the smallest air gap in thigh circumference. The waists, abdomen, and hip circumferences of older women often become larger while their legs become slimmer. This study accounted for those factors in determining a pattern suitable for the lower-body shape of old-old aged women. However, participants only analyzed four patterns and compared them with women 70 to 85, years of age. Therefore, it is necessary to develop industrial patterns applicable to a wide age group.

A Study on the Effect of Open and Closed Room Doors on Apartment Ventilation Characteristics (공동주택에서 각 실 문의 개폐에 따른 환기 특성 연구)

  • Choi, Im-Kyoo;Kim, Young-Il;Chung, Kwang-Seop
    • Proceedings of the SAREK Conference
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    • 2008.11a
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    • pp.469-474
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    • 2008
  • The objective of this study is to propose basic design guidelines for more effective air ventilation system in apartments. It is well known that ventilation depends on whether the room doors are open or closed as well as people's living patterns. This study considers 84 ㎡-sized apartment which has extended living room without balcony. Ventilation of bathroom and kitchen is not considered. The height of the building, external air pressure and air infiltration through the windows are also neglected. The regulation on indoor air quality made it mandatory that the air change per hour be more than 0.7. Four models are suggested to study the effect of open and closed doors. Models 1 and 3 are open door types and models 2 and 4 are closed door types. The open types have 50 mm hole near the top of the door to substitute exhaust outlet. The ventilation effectiveness was evaluated by 3-dimensional numerical simulation using finite volume method by a commercial software. This work compares air flow, temperature of air, age of air and the efficiency of ventilation of apartments with wooden doors of bedroom 1 and 2, which are open or closed.

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An Experimental Study of Ventilation Effectiveness in Mechanical Ventilation systems using a Tracer Gas Method

  • Lee, Jae keun;Kang, Tae-Wook;Lee, Kam-Gyu;Cho, Min-Chul;Shin, Jin-Hyuk;Kim, Seong-Chan;Koo, Jeong-Hwan;Lee, Jong ho
    • Journal of Mechanical Science and Technology
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    • v.14 no.11
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    • pp.1286-1295
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    • 2000
  • The ventilation effectiveness is evaluated as a function of air exchange rate and supply / extract locations in a simplified model chamber using a tracer gas technique of CO$_2$ gas injected into a supply duct. Ventilation systems consist of supply and extract fans, a CO$_2$gas generator, a CO$_2$gas analyzer and a test chamber. The ventilation effectiveness is evaluated using a step-down method based on ASTM Standard E741-83. The room mean age of the model chamber is decreased with increasing air exchange rate fanged from 6to 10 air changes per hour. The ventilation effectiveness of the mechanical inlet/natural extract system is better than that of the mechanical extract system.

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The study on the effect of the solar radiation on thermal comfort and ventilation performance in room space (태양일사가 실내공간의 열적 쾌적성과 환기성능에 미치는 영향에 관한 연구)

  • Yeon, Seong Hyeon;Lee, Hyo Joon;Rhee, Gwang Hoon
    • Journal of the Korean Society of Visualization
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    • v.14 no.1
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    • pp.19-26
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    • 2016
  • Modern people spend much time at indoor space. So, People want to make better indoor air condition. But the facade of building is made of glass to be seen urbanely, the effect of solar radiation makes indoor environment worse. This study designs an open space affected by solar radiation with 4-way cassette air-conditioner. Using numerical simulation, this paper investigates thermal comfort and ventilation performance with discharge angles $30^{\circ}$ and $45^{\circ}$. To study thermal comfort, this paper studies distribution of velocity, temperature and effective draft temperature. Also, this paper introduces concept of air age to study ventilation performance. The flow influenced by solar radiation determines thermal comfort and ventilation performance in room space. This study shows that discharge angle of 45 degree has better thermal comfort and ventilation performance than that of 30 degree.

Estimation of Local Mean Ages of Air in a Room with Multiple Inlets (다중 급기구를 갖는 실내공간에서의 공기연령 산정방법에 관한 연구)

  • Han, Hwa-Taik;Shin, Cheol-Yong;Lee, In-Bok;Kwon, Kyeong-Seok;Kwon, Yong-Il
    • Proceedings of the SAREK Conference
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    • 2009.06a
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    • pp.148-153
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    • 2009
  • This paper considers the age of air in a ventilated space with multiple supply inlets. The local mean age of air at a point from one supply inlet is different from those from the other supply inlets. It is the purpose of the present paper to investigate theoretically the relations between the LMA's from each supply and overall combined LMA whether or not to trace the origins of supply air. Transient concentration distributions are calculated with a step-up injection of tracer gas at each supply inlet, and at both inlets simultaneously. The steady state concentration with a continuous tracer injection at a supply inlet works as a weighting factor for the corresponding LMA in calculating the average overall LMA from multiple inlets.

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An Analysis of Concrete Characteristics by Admixing Agent and Additive Contents According to the Change of Unit-Water (단위수량 변화에 따른 혼화제 종류 및 첨가량별 콘크리트의 특성 분석)

  • Ryu, Hyun-Gi;Woo, Jong-Kwon;Cho, Myeong-Ken
    • Journal of the Korea Institute of Building Construction
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    • v.7 no.4
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    • pp.139-144
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    • 2007
  • The purpose of this study is to analyze concrete characteristics by admixing agent and additive contents according to the change of unit-water to identify its effect on compressive strength. First of all, as for flesh concrete, overall unit-water showed a tendency to decrease as component inclusion rate of admixing agent was increased. In addition, air content showed a tendency to increase by increasing WR, WB, NP series admixing agent contents, on the other hand, the change of air content was gentle by around $1.5{\pm}0.5%$ for S, T, M series agents. Bulk density showed an inverse proportion to the change of air content. As for hardened concrete, expression rate of 3-day age compressive strength was generally decreased for S, T, WR, WB, NP, M series admixing agent component. Also, expression rate of 7-day age compressive strength showed an excellent record for S, M series agents, and expression rate of 28-day age compressive strength showed a tendency to increase more than plain on the whole.

Evaluation and Prediction of Cleanliness Level in the Mini-Environment System Using Local Mean Air-Age (국소평균공기연령을 이용한 국소환경시스템의 청정도 평가 및 예측)

  • Noh, Kwang-Chul;Lee, Hyeon-Cheol;Park, Jung-Il;Oh, Myung-Do
    • Transactions of the Korean Society of Mechanical Engineers B
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    • v.31 no.5
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    • pp.457-466
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    • 2007
  • A numerical and experimental study on the evaluation and the prediction of cleanliness level in the mini-environment system was carried out. Using the concept of local mean air-age (LMA) and effective flow rate, the new direct method for estimating the mini-environment was developed and compared with the previous performance index of airflow pattern characteristics. It was found out that the airflow pattern analysis is a restricted method to estimate the real performance of the mini-environment. The reason is that the airflow pattern cannot predict the effect of the increment of the ventilation rate on the cleanliness level in the mini-environment. While LMA is capable of showing the effects of the contaminant accumulation caused by turbulent intensity, eddy, and the increment of the effective flow rate. This result showed that LMA is more exact and effective performance index than the previous one like the airflow pattern characteristics.

A Study on the Early-Age Strength Property of Concrete Using Liquid Admixture (액상형 조강제를 사용한 콘크리트의 초기강도 특성에 관한 연구)

  • Song, Tae-Hyeob;Lee, Sea-Hyun;Ryu, Deug-Hyun;Park, Cho-Bum
    • Proceedings of the Korea Concrete Institute Conference
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    • 2006.05b
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    • pp.469-472
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    • 2006
  • Amount used of admixture fare is increasing for concrete economic efficiency and ability security. Security of economic efficiency and ability can expect by use of this admixture fare but is displaying a lot of problems on early age strength hold by hydrate delay relatively. Specially, in the case of construction site, concrete strength can speak that interrelation is high with mold removal of forms time. Therefore, is economical and need examination of plan that can secure robber within 3 days using admixture fare such as fly ash and blast furnace slage differential speech to secure function. In this study, adding liquid admixture within 1% of a binding agent quantity to examine these problem with physical characteristic after hardening ago specially, strength change at standard and air dry curing of observed change in priority. Air dried and water curing total strength enhancement effects appeared by thing which is in case of add test result liquid admixture by below 1% and strength deputy by passage of age could know is not big.

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Distributions of Local Supply and Exhaust Effectiveness according to the Room Airflow Patterns (실내 기류패턴에 따른 급기효율과 배기효율의 분포)

  • 한화택;최선호;장경진
    • Korean Journal of Air-Conditioning and Refrigeration Engineering
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    • v.13 no.9
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    • pp.853-859
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    • 2001
  • A pulsed tracer gas technique is applied to measure distributions of local mean age and residual life time of air in a half-scale experimental chamber. The room airflow patterns are flow-visualized by a Helium bubble generator for three different exhaust locations. A supply slot is located at the top of a right wall, and an exhaust slot is either at bottom-left(Case 1), bottom-right(Case 2), or top-left(Case 3) location. Results show that the distribution of LMA and LMR are different from each other, but both of them are closely related to the airflow pattern in the space. Results on overall room ventilation effectiveness are provided depending upon ventilation airflow rates for three different supply-exhaust configurations.

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The Effect of Job Stress Responses on Human Error (직무스트레스 반응이 인적과오에 미치는 영향)

  • Ahn, Kwan-Young;Son, Yong-Seung
    • Journal of the Korea Safety Management & Science
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    • v.13 no.4
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    • pp.53-60
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    • 2011
  • Job stress weakens physical ability causing the diseases related to working condition, decreases a production level, and increases mistakes and accidents. This study examined the relationship between job stress and human error, and focused on the moderating effect of age and maintenance type on the relationship between job stress and human error. The study used a quantitative design based on the 450 questionnaires of maintenance personnel in the Air force. The results of multiple regression analysis showed that physiological and psychological stress responses have positively related with human error. In moderating effect test, age appeared to impact on the relationship between physiological/behavioral stress and human error.