• 대한전자공학회:학술대회논문집
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• 대한전자공학회 2008년도 하계종합학술대회
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• pp.339-340
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• 2008

This paper presents a novel design of the printed hyperpolar-transformed Sierpinski Carpet (HSC) antenna. By hyperpolar transforming the Sierpinski carpet geometry, from isotropic scaling symmetry to equiangular scaling symmetry, we get improved performance rather than that of the general Sierpinski Carpet antenna. The design parameter and performance of the proposed monopole antenna are investigated by simulation. And we showed that proposed HSC geometry gives more freedom for wideband antenna design such as flare angle, (angular)scale factor.

• 한국응용과학기술학회지
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• 제23권2호
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• pp.147-152
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• 2006

The accidents occurred by unstable material which is easily exploded or burnt up were caused by heat and collision under the condition of relatively low temperature without oxygen, have been reported frequently. However, the amount of the unstable material is getting higher by development of fine ceramic research area even though its dangerous characteristic is disregarded. This research studied a heat stability and measured boiling point of various carpet material. Carpet has been used in home as well as general indoor usage. Now a day, carpet material which is hardly burnt has been on commercial, but its detailed unstable conditions is not mentioned. This research reports the measurement of the initial temperature of generation heat and heat-radiation change on differential scanning calorimeter (DSC). The DSC data of nylon bulked continuous filament (N-BCF) yam 100%, nylon (NY), poly propylene (PP), and a new material named polytrimethylene terephthalate (PTT) are studied and researched about the effect of them using TGA, furnace, and direct-burning experiment.

• 한국화재소방학회논문지
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• 제28권2호
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• pp.48-53
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• 2014

본 연구에서는 운동장과 건물의 옥상 등 실외에 설치되고 있는 인조잔디에 대해 국내 기준에 의한 화재위험성을 평가하고자 한다. 현재 인조잔디에 대한 국내 기준은 실외에 한하고 있으며 특히 학교체육시설이라고 국한하여 KS M 3888-1에 강제하고 있고, 실내 기준은 소방방재청고시(2012-35호)에 권장사항으로 규정하고 있다. 이에 본 연구는 강제규정하고 있는 실외에 설치되는 인조잔디에 국한하여 연소시험을 진행하였다. $45^{\circ}$ 방염시험을 진행하여 분석한 결과, 현재 설정되어 있는 기준이 화재의 위험성을 판단하기에 매우 미흡함을 확인하였다. 이에 바닥재로 통용되고 있는 방염처리된 카페트의 연소시험을 통해 그 특징을 비교한 후 분석하였다. 45o 방염시험기를 이용하여 착화성을 시험한 후 평가한 결과, 해당기준에서 크게 벗어난 인조잔디와 달리 카페트는 방염성능기준을 만족하였다. 이에 추가로 인조잔디에 대해 콘칼로리미터시험을 진행하여 착화 이후의 연소특성을 분석 및 평가함으로써 실외 적용되는 인조잔디의 기준 강화를 위한 대책을 제안하였다.

• 한국학교보건학회지
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• 제23권1호
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• pp.29-40
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• 2010

Purpose: The purposes of this study were: (a) to assess indoor air quality such as $PM_{10}$, $CO_2$ concentrations in child daycare centers, (b) to compare the levels with each standard, and (c) to identify teachers' awareness of indoor air quality in child care centers. Methods: Data were obtained from seventeen child daycare centers and ninety-eight teachers in a district of Seoul, from April 3 to May 12, 2009. Collected data were analyzed by SAS 8.2, and descriptive statistics, $x^2$ test, student t-test, Pearson correlation analysis, and Spearman rank correlation were used. Results: The mean of $PM_{10}$ and $CO_2$ level were $50.3{\mu}g/m^3$ and 792.1ppm. Sixteen child daycare centers (94.2%) met the guidelines of the $PM_{10}$ level, so did thirteen child daycare centers (76.5%) in the $CO_2$ level. $CO_2$ levels were significantly low in child daycare centers using air cleaners than those do not using them (t=-6.03, p<.001). Types of child daycare centers were significantly correlated to the levels of $CO_2$, which public child daycare centers were low in $CO_2$ levels than those of private child daycare centers (t=-2.54, p=.013). There was no significant correlation between teachers' awareness and management attitude of indoor air quality while teachers' awareness of indoor air quality significantly raised the frequency of carpet cleaning. Methods of cleaning routines were significantly correlated with $PM_{10}$, and $CO_2$ levels. Conclusion: The $PM_{10}$ and $CO_2$ concentrations in child daycare centers were satisfactory. Those conditions are affected by general characteristics of child daycare centers and teachers' attitude regarding management of indoor air quality.

• Acta Via Serica
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• 제7권2호
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• pp.109-132
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• 2022

Two of the main elements of Persian tangible heritage are rugs and gardens, which have evolved together from the dawn of Iranian history. Emerging from the same system of thought and geographical location, together they represent the Persians' world views, desires, dreams, and design paradigms. In this study, the Persian Garden's patterns, elements, typology, and meanings are introduced and compared with the same aspects of Persian rugs. This paper uses a qualitative comparative methodology to analyze rugs' designs and patterns in relation to Persian Gardens' design principles. Data is collected primarily through library study and observation. The author uses two categories for comparison: meanings and forms. First, the author identifies underlying meanings common to the two art forms and then introduces form, function, and general principal patterns into the analysis. There is a type of rug pattern, known as Chahar-Bagh (literally, "four gardens"), that mirrors a garden design, down to the details, which is the focus of this paper. Additionally, other representations of Persian Gardens in rug design, such as Shekargah ("hunting pattern"), are discussed, as are other rug patterns with fewer elements borrowed from garden design. The paper also considers several motifs that represent flora common in gardening on the Iranian plateau, some of which have symbolic meanings dating to the Zoroastrian era. By comparing these two mediums of art (garden and rug) in the context of Persian history and geography, it becomes clear that the Persian rug design, in its roots, is an attempt to bring a garden into interior space. The study shows that the forms, patterns, and meanings reflected in Persian rugs render the study of their designs incomplete without considering the history of gardens.

• 한국수산과학회지
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• 제26권2호
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• pp.182-197
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• 1993

조하대 해조군집은 뚜렷하지는 않지만 상${\cdot}$중${\cdot}$하부로 구분되었다. 상부는 S. saganmianum, P. lanceolata, G. tenella, P. capillacea 등의 직립분기형으로 구성되었고, 투명도가 높은 지역에서는 수심 $3{\sim}5$까지이며, 탁도의 간섭에 의해 확장될 수 있었다. 중부는 투명도가 높은 외양역에서만 형성되었고, 그 범위는 $5{\sim}20m$ 사이이며, E. cava, Sargassum spp. 등의 대형갈조류에 의해 대표되며, 탁도가 높은 외양역에서는 상부에서 하부로 바로 이행하였다. 하부는 투명도가 높은 외양역은 중부와 이질적인 식생으로 보기 어렵고, 환경압박에 따른 양적인 차이로서 이해되었다. 출현종의 식물지리적 분포를 볼 때 본 조사지를 2 구역으로 나눌 수 있었다. 문섬의 구성종이 지리적 불연속을 이루는 것은 수온차에 의한다고 판단되었다. 문섬의 식생특성은 출현종수는 내만역의 도서보다 적으나 고유종이 많고, 다육질형 대형갈조류의 구성비가 높고, 종다양도 및 생체량은 거문도, 여서도 등과 유사하였다. 문섬을 제외한 9개 섬은 식생의 연속성을 나타내지만, 풍도의 차이가 있었다. 이중 관탈도, 여서도, 거문도, 추자도, 홍도는 투명도가 높은 외양역에 위치하며, 식생의 풍도가 유사하여 외양성 식생구로 뚜렷히 구분할 수 있었다. 반면 만재도, 소리도, 욕지도, 비진도는 비교적 고탁도대 내측에 위치하여 외양도서에 비해 풍도가 낮게 나타났으나, 분류군의 구성비로 볼 때 외양성 식생구의 성격을 띄고 있는 이행단계의 식생구라고 판단되었다. 그리고 이러한 식생의 구분에 있어서 탁도에 따른 조하대 E. cava 군락의 유무가 매우 중요함을 시사하였다.