• 수산해양기술연구
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• 제32권4호
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• pp.386-394
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• 1996

The temporal variations of the transparency with water temperature, salinity and density during spring-neap tidal cycle of spring, summer, autumn and winter time were investigated at 34 stations using observation data in Deukryang Bay, Korea, in 1995. It was found that the transparency was depended on spread of tidal currents and vertical stratification of water. The depth of transparency during neap tide was deeper than that of spring tide. The value of transparency in summer was the largest among four seasons. We concluded that the vertical stratification intensity of water mass and vertical distribution of transparency.

• 한국화재소방학회논문지
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• 제32권4호
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• pp.75-85
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• 2018

2016년 6월 영국 그렌펠 타워 화재는 외단열에 의한 수직화재확산으로 인한 대표적인 피해사례이다. 외단열 공법에서 많이 사용되는 유기단열재는 단열성능이 좋은 반면 화재에 취약한 단점이 있다. 알루미늄 복합패널을 외벽 마감재로 사용하는 외단열 공법에서 알루미늄 내부에 사용되는 플라스틱은 수직 화재확산의 원인으로 지목되고 있다. 알루미늄복합패널을 외벽에 고정하기 위해 사용되는 철재 프레임 때문에 외벽과 외벽 마감재 사이에 중공층이 형성된다. 외벽에 화재가 발생하면 가연성외벽의 연소뿐만 아니라 단열재로부터 발생된 화염이 중공층을 통해 수직으로 급격히 확산되어 인명 및 재산피해가 발생할 수 있다. 국내의 경우 국토교통부고시 2015 - 744에 의한 소재단위 성능시험이 수행되고 있으며, 영국에서는 실제 규모의 화재시험으로 외벽의 수직화재확산 시간의 측정이 가능한 BS8414 시험이 시행되고 있다. 본 연구에서는 현행 국내 고시 기준으로 적합한 준불연 소재의 알루미늄복합패널을 대상으로 영국에서 시행되고 있는 실규모 외벽화재시험(BS 8414)을 수행하여 수직화재확산에 대한 거동 관찰과 현재 마감재료의 소재단위 평가의 한계를 확인하고자 하며, 실제 규모의 화재 시험을 통한 외벽화재 화재확산 방지를 위한 시스템 도입 필요성 확인하고자 한다.

• 한국화재소방학회논문지
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• 제32권1호
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• pp.66-75
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• 2018

랙크 내 설치되는 차단막은 초기 화재확산을 지연시키는데 큰 역할을 담당하고 있으나 소화를 목적으로 설치되는 천장형 스프링클러의 입장에서는 소화수의 원활한 공급에 장애물로서 비춰질 수도 있다. 이에 In-Rack 스프링클러와 차단막을 동시에 적용하는 방법 등이 제시되고 있으나 차단막의 설치조건에 따른 화재확산 지연성능 및 In-Rack 스프링클러에 미치는 영향 등에 관한 연구는 부족한 실정이다. 이에 본 연구에서는 축소모델 화재실험을 통해 차단막의 설치조건에 따른 화재확산 지연성능과 In-Rack 스프링클러에 미치는 영향 등을 분석하였다. 그 결과, 랙크 내에 수평과 수직 차단막을 동시에 설치한 경우, 4배 이상의 화재확산 지연성능이 발휘되는 것을 확인하였으며, 구획화로 인한 구획 내 온도 상승 또한 약 2~3배 가량 높은 것으로 나타나 In-Rack 스프링클러가 조기에 작동될 수 있도록 유도하는 긍정적인 효과 또한 존재하는 것으로 나타났다.

• Maxillofacial Plastic and Reconstructive Surgery
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• 제21권1호
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• pp.41-47
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• 1999

The route of bony invasion and spread pattern of tumor in the mandible are important in management of gingival cancer. Ten patients with gingival cancer involving mandibular body region were operated by composite resection. The radiographic and histopathologic features of the mandibular invasion and spread were analysed and compared. Our results showed that histopathologic extent of tumor invasion were greater than the radiographic prediction, especially in width of the tumor. And the pattern of bony invasion in the body area was mostly found in transmedullary spread rather than perineural spread. The vertical involvement in the mandibular body with tumor was evaluated. It indicated that if a oncologic surgeon was to ensure an adequate safety margin for extirpation of tumor, in most cases, the maintenance of the mandibular continuity is difficult. If the mandibular involvement by gingival cancer was identified radiographically and clinically, segmental mandibulectomy was required for the adequate safety margin, in consideration of the spread pattern in the body area.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• 제49권2호
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• pp.91-95
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• 2023

This study examined the effects of a vertical incision on postoperative edema after third molar extraction. The study design was that of a comparative split-mouth approach. Evaluation was performed via magnetic resonance imaging (MRI). Two patients with homogeneous bilateral impacted mandibular third molars were enrolled. These patients underwent facial MRI within 24 hours after simultaneous extraction surgery. Modified triangular flap and enveloped flap incisions were made. Postoperative edema was evaluated by MRI and was assessed according to anatomical space. The two pairs of homogeneous extractions demonstrated that vertical incisions were associated qualitatively and quantitatively with extensive postoperative edema. The edema associated with these incisions spread toward the buccal space, beyond the buccinator muscle. In conclusion, a vertical incision with mandibular third molar extraction was related to edema in the buccal space and the fascial space, which contributed to clinical facial swelling.

• 한국건축시공학회:학술대회논문집
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• 한국건축시공학회 2020년도 봄 학술논문 발표대회
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• pp.111-112
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• 2020

As buildings in South Korea become more skyscrapers, the risk of fire is also emerging. Thus, regulations, regulations, and guidelines are being improved to prevent the spread of smoke in the event of a fire in high-rise buildings, but research on smoke flow and pressure distribution in vertical spaces is insufficient. Therefore, in this study, the temperature of each floor in the vertical space according to the size of the fire is measured through the miniature model experiment, and the pressure difference is calculated to establish the basic data for the improvement of the performance of domestic air supply facilities in the future. Thus, a scale model of one-sixth the size of the actual building was produced to measure the temperature, and the pressure difference was derived by substituting the value for the expression. The pressure difference varies depending on the size of the cause of the fire, and it is believed that the differential pressure and conditions of the building should be taken into account before calculating the supply volume for the analysis of the pressure difference according to the size of the cause of the fire in the event of fire.

• 한국실내디자인학회논문집
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• 제18권3호
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• pp.102-113
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• 2009

The SARS virus began to appear and spread in North America and Southeast Asia in the early 2000' s, infecting and harming many people. In the process of examining the causes for the virus, studies on the airborne SARS virus and the way it spread were carried out mainly in the medical field. In the field of architecture, studies were done on the diffusion of air pollutants in buildings using gases such as $CO_2$, $N_2O$, or $SF_6$, but research on virus diffusion was limited. There were also explanations of only the diffusion process without accurate information and discussion on virus characteristics. The aim of this study is to analyze the physical characteristics of airborne virus, consider the possibility of using coupled analysis model and tracer gas for analyzing virus diffusion in building space and, based on reports of how the infection spread in a hospital where SARS patients were discovered, analyze infection risk using tracer gas density and also diffusion patterns according to the location, shape, and volume of supply diffusers and exhaust grilles. This paper can provide standards and logical principles for evaluating various alternatives for making decisions on vertical or horizontal ward placement, air supply and exhaust installation and air volumes in medium or high story medical facilities.

• 한국화재소방학회논문지
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• 제26권4호
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• pp.48-54
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• 2012

외장재의 수직화재에 의한 동시다발적인 화재 발생 시 피난위험성을 확인하기 위하여 시나리오에 의한 피난시뮬레이션을 수행하였다. 피난시뮬레이션 결과, 가연성 외장재가 연소하면서 수직화재로 확대되어 개구부를 통해 유입되는 화재에 의해 층 대부분이 550초에서 650초 사이에 허용피난안전시간에 도달하였고, 특히 1층은 358초에, 6층과 10층은 490초와 473초에 피난한계에 도달하였다. 또한, 1층과 26층, 28층~30층의 총 5개 층에서 피난위험성이 나타나는 것으로 분석되었다. 동시다발적인 화재성상으로 인해 모든 재실자가 전관 피난을 하여 15층 이상의 고층 부분에서 병목현상이 심하게 발생하여 피난계단으로 진입이 어렵다는 것을 확인하였다. 특히, 1층의 경우는 발화지점과 가까워서 358초에 허용안전피난시간에 도달하여 상부층에 있는 699명의 피난이 난해한 것으로 분석되었다. 외장재 화재의 위험성 대책으로 불연성 외장재의 사용과 연소 확대를 방지하기 위한 적극적인 진압방법의 도입이 요구된다.

• Environmental Sciences Bulletin of The Korean Environmental Sciences Society
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• 제4권4호
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• pp.263-271
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• 2000

To investigate the distribution of air pollutants dispersion in the horizontal wind fields, a chaff release experiment was carried out by an airplane. The temporal and spatial variations of a chaff plume from an elevated point source using the WSR-88D(NEXRAD) radar. The observed profiles of radar reflectivity were compared with the Gaussian diffusion model at slightly unstable atmospheric condition. The present study shows that the distributions of radar reflectivity from chaffs and their concentration by the model are in general agreement with time variation. The dispersion coefficients in downwind($\sigma$(sub)x) and crosswind($\sigma$(sub)y) spread data exceeded what has generally been found at Pasquill and Brigg\`s estimates. As a result, it was clearly shown that horizontal and vertical diffusion coefficients are more accurately determined as compared with theoretical coefficients. At longer diffusion distances(than 10km), a radar observation provided the determination of maximum range and diffusion height more qualitatively, too.

• 한국환경복원기술학회지
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• 제7권6호
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• pp.19-28
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• 2004

Segmental Retaining Wall(SRW) has been variously applying in Civil and Architecture construction. Recently, the application of environmental element in all type's structures came to essential requirement, and the construction cases of retaining wall using reinforced soil and block are more increased than the past. But, this trend more widely was spread environmental element as landscape work for the backside of reinforced retaining wall as well as block itself. New environmental block, Greenstone Block, developed to apply of this tendency. The retaining wall system using Greenstone can be environmental constructing at both block itself and backside of retaining wall. The material tests, the axial compressive strength test of block and bending test of fiber-pipe, exercised to design and construction of vertical SRW, which were satisfied NCMA standard. Through this procedure, Rewall (ver 1.0) was developed, which can be automation design of SRW including internal stability, external stability and local stability. And these can be considered setback of retaining wall, as well the examples of vertical retaining wall using block presented to satisfying the follows; strength of reinforced geotextile, height of retaining wall, surcharge, types of backfill and groundwater level etc. Many problems investigated on after or before of construction were due to local failure, insufficiency of bearing capacity and groundwater level. Especially, the local failure was many occurred to during compaction or after construction, and the cases of SRW construction is similar to the results of model test on vertical SRW.