• Title/Summary/Keyword: ceiling effect

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Natural Ventilation Planning by Analysis on Air Velocity Property of a Traditional Korean House (한국 전통주거의 기류 분석을 통한 자연통풍 설계 연구)

  • 최윤정;김인선;허범팔
    • Proceedings of the Korean Institute of Interior Design Conference
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    • 2001.05a
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    • pp.117-120
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    • 2001
  • This study is a preliminary research to develop design principles for environmentally friendly housing. The purposes of study are to investigate the literatures related passive design for summer and theory of ventilation, to analyze the indoor airflow patterns in traditional Korean house during summer, and to propose the design factors for effective passive cooling system. The analysis for airflow patterns was focused on the ‘An bang’and the ‘Dae Chung’in the ‘An Chae’of a traditional house located in Seoul. Field measurements of air temperature and air velocity were carried out at 30 different measuring points with 8 different window-opening conditions. The measurements were taken on the hottest summer days in August 2000. It is concluded that from an environmentally friendly standpoint design factors to control indoor thermal environment by a passive cooling system during the summer are as follows; ceiling structure has thermal performance like a time-lag effect, optimum height and length of eaves which can prevent sunlight and divert airflow toward the sitting level, building arrangement acceptable the prevailing wind, strategic window arrangement which makes cross ventilation possible (especially north-south) at the sitting level, window opening condition which is possible to intersect two cross-ventilation stream at the main living areas, northward windows remaining in shade to create the air pressure difference, and planning building shape like a bracket that has optimum width and depth.

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Evaluation of Natural Ventilation Performance using the Multi-Functional Floor Heating System (다기능온돌시스템을 이용한 자연환기성능 평가)

  • Cho, Dong-Woo;Yu, Ki-Hyung;Yu, Jung-Yeon;Jung, Hae-Kwon
    • Proceedings of the SAREK Conference
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    • 2007.11a
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    • pp.105-112
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    • 2007
  • Recently developed raised floor heating system is not only capable of basic function to reduce noise between floors, but also is a multi-functional floor heating system enabling natural ventilation. The procedure of this system for natural ventilation is to import outdoor air through bottom space of the floor heating system, circulate indoor space and discharge it out of ceiling. In winter, powerless natural ventilation is possible with buoyancy effect caused by temperature difference between outdoor and indoor. And it also allows saving of energy by importing pre-heated air in bottom space of the floor heating system. To evaluate ventilation performance of this system, on-site measurement was conducted in 2 test laboratories, and the nominal air change rate was satisfied as 0.4$\sim$0.8 h-1 under the condition of outdoor temperature $5^{\circ}C{\sim}-5^{\circ}C$, which was evaluated as highly possible to be applied as a natural ventilation system in multi-family houses.

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Analytical Studies on Seismic Performance of Multi-Story Coupled Piping System in a Low-Rise Building

  • Jung, WooYoung;Ju, BuSeog
    • Journal of the Earthquake Engineering Society of Korea
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    • v.17 no.4
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    • pp.181-186
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    • 2013
  • The construction costs for nonstructural systems such as mechanical/electrical equipment, ceiling system, and piping system occupy a significant proportion of the total cost. These nonstructural systems can also cause considerable economic losses and loss of life during and after an earthquake. Therefore, reduction of seismic risk of nonstructural components has been emerging as a key aspect of research in recent year. The primary objective of this study was to evaluate the seismic performance of a single-story and multi-story piping system installed in low-rise building and to identify the seismic vulnerability of the current piping systems. The seismic performance evaluation of the piping systems was conducted with 5 different earthquakes to account for the ground motion uncertainty and the preliminary results demonstrated that the maximum displacements of each floor in the multi-story piping system increased linearly with increasing floor level in the building system. This study revealed that the current design piping systems are significantly sensitive to the effect of floor height, which stress the necessity to improve the seismic performance of the current piping systems by, for example, strengthening with seismic sway bracing using transverse/longitudinal bracing cables or hangers.

Rediscovery of Nefopam for the Treatment of Neuropathic Pain

  • Kim, Kyung Hoon;Abdi, Salahadin
    • The Korean Journal of Pain
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    • v.27 no.2
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    • pp.103-111
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    • 2014
  • Nefopam (NFP) is a non-opioid, non-steroidal, centrally acting analgesic drug that is derivative of the nonsedative benzoxazocine, developed and known in 1960s as fenazocine. Although the mechanisms of analgesic action of NFP are not well understood, they are similar to those of triple neurotransmitter (serotonin, norepinephrine, and dopamine) reuptake inhibitors and anticonvulsants. It has been used mainly as an analgesic drug for nociceptive pain, as well as a treatment for the prevention of postoperative shivering and hiccups. Based on NFP's mechanisms of analgesic action, it is more suitable for the treatment of neuropathic pain. Intravenous administration of NFP should be given in single doses of 20 mg slowly over 15-20 min or with continuous infusion of 60-120 mg/d to minimize adverse effects, such as nausea, cold sweating, dizziness, tachycardia, or drowsiness. The usual dose of oral administration is three to six times per day totaling 90-180 mg. The ceiling effect of its analgesia is uncertain depending on the mechanism of pain relief. In conclusion, the recently discovered dual analgesic mechanisms of action, namely, a) descending pain modulation by triple neurotransmitter reuptake inhibition similar to antidepressants, and b) inhibition of long-term potentiation mediated by NMDA from the inhibition of calcium influx like gabapentinoid anticonvulsants or blockade of voltage-sensitive sodium channels like carbamazepine, enable NFP to be used as a therapeutic agent to treat neuropathic pain.

Effects of Surface Radiation on the Unsteady Natural Convection in a Rectangular Enclosure

  • Baek, Seung-Wook;Kim, Taig-Young
    • International Journal of Aeronautical and Space Sciences
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    • v.3 no.1
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    • pp.95-104
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    • 2002
  • Numerical solution of the full Navier-Stokes equation as well as the energy equation has been obtained for the unsteady natural convection in a rectangular enclosure. One side wall was maintained at very high temperature simulating fires. Especially the effect of surface radiation was taken into account. While the enclosed air was assumed to be transparent, the internal walls directly interacted one another through the surface radiation. Due to a significant temperature difference in the flow field, the equation of state was used instead of the Boussinesq approximation. It was found that the rapid heating of the adiabatic ceiling and floor by the incoming radiation from the hot wall made the evolution at thermo-fluid field highly unstable in the initial period. Therefore, the secondary cells brought about at the floor region greatly affected the heat transfer mechanism inside the enclosure. The heat transfer rate was augmented by the radiation, resulting in requiring less time for the flow to reach the steady state. At the steady state neglecting radiation two internal hydraulic jumps were clearly observed in upper/left as well as in lower/right comer. However, the hydraulic jump in the lower/right comer could not be observed for the case including radiation due to its high momentum flow over the bottom wall. Radiation resulted in a faster establishment of the steady state phenomena.

T A Study on the Composition Elements and Evaluation of Image in Lobby of the Local Cultural Institution (지역문화회관 로비공간의 이미지 형성요소와 평가에 관한 연구)

  • Son, Kwang-Ho;Kang, Hye-Kyung
    • Korean Institute of Interior Design Journal
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    • v.17 no.3
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    • pp.68-76
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    • 2008
  • This study investigated composition elements and estimation of image in lobby from user viewpoint that is the central space of local cultural institution, and spectator mainly utilizes. Progress process of study develops investigation device including literature investigation, professional panel and lobby space image measurement tool through on-the-spot probe and, executed supporting research to spectator. As the result of the study, first, lobby space image exerts absolute effect to local cultural institution image-building, and is grasped on constituent that floor, ceiling, entrance and lighting and decoration is important in image-building of lobby space. Second, the image of the important lobby space was grasped in order of convenient image(M = 3.98) bright image(M = 3.87), and cozy image(M = 3.80). Third, the results on investigating semantic structure of the lobby image, emotional factor, styling factor, spatial factor, and peculiar factor are composed of important factors that decides image of lobby space. Fourth, as the result of image analysis for lobby space, the degree of satisfaction for the local cultural institution was entirely low against the importance. In particular, the image for convenience, individuality, locality and dignity was not sufficient in all the three places. Therefore, lobby design of local cultural institution shall also suggest more various lobby space image from culture oriented viewpoint.

A Study of the Usefulness of Pediatric Balance Scale as a Prediction Indicator for Gross Motor Function Classification System in Children with Cerebral Palsy

  • Lim, Hyoung-Won
    • The Journal of Korean Physical Therapy
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    • v.28 no.1
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    • pp.22-26
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    • 2016
  • Purpose: The purpose of this study was to evaluate the relation between PBS scores and GMFCS levels and to examine whether pediatric balance scale (PBS) scores were useful for predicting gross motor functional classification system (GMFCS) levels in children with cerebral palsy. Methods: This cross-sectional study was performed conducted for to evaluatione of PBS and GMFCS using in 26 children with cerebral palsy (16 males and 10 females with GMFCS level I to III). PBS total and item scores at different levels of GMFCS were measured. Results: The hHigh PBS item average scores obtained from standing and postural change dimensions except sitting dimension were observed at the low levels of GMFCS and these results were statistically significant (p<0.05). The relation between PBS (standing and postural change dimensions) and GMFCS levels were was significantly different, except the relation between PBS sitting dimension and GMFCS levels showing a ceiling effect. Conclusion: GMFCS is designed to for classificationy of gross motor functions emphasizing on walking movement and PBS is was developed to for evaluatione of functional balance. Based on the results of this study showing high relation between GMFCS levels and PBS scores, PBS scores can be used for predicting GMFCS levels.

Analysis on Dimming Control Effect by Algorithm Variation for Direct/Indirect Lighting in a Small Office (알고리듬 변화에 따른 직/간접 조명시스템에 대한 디밍제어 효과분석)

  • Kim, Soo-Young
    • Journal of the Korean Solar Energy Society
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    • v.28 no.5
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    • pp.36-48
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    • 2008
  • This study examines the influence of control algorithms on dimming performance to determine appropriate control setting when direct/indirect lighting is controlled by a daylight dimming system. Computer simulation were performed for a small office with double skin envelope under various daylight conditions. A retractable fabric shading and Venetian blind were applied for internal and external envelopes under three CIE standard sky conditions. Unshielded and partially-shielded photosensors were used, and three control algorithms were applied for the sensors. In general, dimming level was too excessive due to the direct impact of light from lighting fixture to the photosensor. Providing insufficient lighting output, the unshielded photosensor completely failed to secure required illuminance under any daylight condition. When a partially-shielded photosensor was applied under clear sky, three setting points functioned effectively. Less sensitivity for the partially-shielded photosensor was effective to control the dimming system optimally with reasonable energy saving. However, the daylight dimming control system for direct/indirect lighting does not appear to be energy effective when photosensors without enough shielded area is installed on ceiling where light from fixtures reaches directly.

Two Cases of Opioid-Induced Hyperalgesia in Cancer Patients Treated with Opioids for Pain Management (아편유사제를 사용한 암환자에서 발생한 통각과민 2례)

  • Hong, Sukchul;Kwon, Jung Hye;Han, Su Jung
    • Journal of Hospice and Palliative Care
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    • v.22 no.2
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    • pp.100-104
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    • 2019
  • Opioids are important drugs for the management of severe cancer pain without a ceiling effect. However, opioid administration leads to dose-limiting complications including drowsiness, hallucinations, delirium, respiratory depression, cognitive impairment, seizure, myoclonus, and hyperalgesia. Opioid-induced hyperalgesia (OIH) is a paradoxical phenomenon as opioid exposure increases pain sensitivity. Reducing or stopping opioids, opioid rotation, or co-administration of N-methyl-D-aspartate (NMDA) antagonists have been suggested for the management of OIH. In this study, we report two clinical cases of successful management of OIH in cancer pain patients that were treated with opioids.

Seismic Performance Evaluation of Vibration Attenuation Wireway-Pulley System Using the FE Analysis (유한요소해석을 통한 진동 감쇠형 와이어웨이시스템의 내진성능 검증)

  • Tran, V. Han;Jin, Su Min;Kim, Sung Chan;Cha, Ji Hyun;Shin, Jiuk;Lee, Kihak
    • Journal of Korean Association for Spatial Structures
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    • v.20 no.4
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    • pp.185-192
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    • 2020
  • A new lighting support structure composing of two-way wires and pulley, a pulley-type wireway system, was developed to improve the seismic performance of a ceiling type lighting equipment. This study verifies the seismic performance of the pulley-type wireway system using a numerical approach. A theoretical model fitted to the physical features of the newly-developed system was proposed, and it was utilized to compute a frictional coefficient between the wire and pulley sections under tension forces. The frictional coefficient was implemented to a finite element model representing the pulley-type wireway system. Using the numerical model, the seismic responses of the pulley-type wireway system were compared to those of the existing lighting support structure, a one-way wire system. The addition of the pulley component resulted in the increasement of energy absorption capacity as well as friction effect and showed in significant reduction in maximum displacement and oscillation after the peak responses. Thus, the newly-developed wireway system can minimize earthquake-induced vibration and damage on electric equipment.