• Title/Summary/Keyword: tall

Search Result 1,920, Processing Time 0.036 seconds

Experimental Study on the Vibration Control Capacity of Hybrid Buckling-Restrained Braces (하이브리드 비좌굴가새의 진동제어능력에 관한 실험적 연구)

  • Kim, Do Hyun;Ju, Young Kyu;Kim, Myung Han;Sung, Woo Gi;Kim, Sang Dae
    • Journal of Korean Society of Steel Construction
    • /
    • v.21 no.1
    • /
    • pp.83-91
    • /
    • 2009
  • Buckling Restrained Braces (BRBs) show good seismic behavior. They do not dissipate energy, however, when they are subjected to minor earthquakes or wind. Hybrid Buckling Restrained Braces (H-BRBs), which can improve the wind performance of the BRB system, are a kind of hybrid damper system composed of a viscoelastic damper and BRBs. In this paper, two H-BRB specimens with different cores were experimentally investigated to ensure the structural behavior of the H-BRB system in an elastic range. The axial deformation of the primary resisting system was compared with that of the secondary resisting system, and the equivalent damping ratio of the H-BRBs was estimated. It was concluded that H-BRBs with double shear dampers show good structural behavior and are applicable to tall buildings, to improve the building performance at a comfortable level.

Resistance to the Fungal Pathogen Phytophthora infestans of Transgenic Potato Plants Harboring of Chitinase Gene (Chitinase 유전자 도입 형질전환 감자식물체의 역병저항성)

  • Choi, Kyung-Hwa;Yang, Duk-Chun;Kim, Hyun-Soon;Choi, Kyung-Ja;Cho, Kwang-Yeon;Jung, Hyuk
    • Korean Journal of Plant Tissue Culture
    • /
    • v.26 no.3
    • /
    • pp.177-182
    • /
    • 1999
  • A fungal infection assay between normal and transgenic potato harboring chitinase gene in cultivar Belchip was investigated. In the first stage of experiment, seven transgenic lines having 12cm tall were tested for their resistance against potato late blight pathogen Phytophthora infestans by infection with the zoospores, artificially, Susceptibility to potato late blight infection could be classified into three types based on the rate. In terms of resistance to the disease, two lines were higher, two lines were more suppressive, and three lines were similar as compared with the control. In the following experiment, only 2 risistant lines and 1 suppressed line were used to confirm the resistance again. The results of both experiments were similar. Furthermore, two highly resistant transgenic lines grown in field exhibited a higher resistance than control under the conditions of natural ocurrence of the fungal disease.

  • PDF

An Experimental Study of Hydraulic Characteristic Variation due to Tall Trees on Floodplain (홍수터의 교목식재에 따른 수리학적 특성 변화)

  • Lee, Joon-Ho;Song, Ju-Il;Han, Chyung-Such;Yoon, Sei-Eui
    • Proceedings of the Korea Water Resources Association Conference
    • /
    • 2007.05a
    • /
    • pp.941-945
    • /
    • 2007
  • 도시하천에서 환경적 기능이 중요성을 더해가면서 복단면의 홍수터에 교목이 식재 되어지는 경우가 있다. 그러나 식생은 하천의 흐름저항을 크게 하고 통수능을 감소시켜 수위상승이나 국부적인 유속 증가를 유발할 수 있으므로 하천에 식생대를 조성하거나 향후 관리를 위해서는 식재로 인해 변화되는 수리학적 특성들을 이해하는 것이 무엇보다 중요하다. 따라서 본 연구에서는 하천복원의 주 대상이 될 수 있는 도시하천의 홍수터에 교목의 식재 가능성을 알아보기 위해 수리실험을 실시하였다. 실험수로는 우리나라 도시하천의 대부분이 홍수터를 갖는 복단면임을 고려하여 복단면 형태로 제작하였으며, 실험은 길이 16 m, 폭 0.8 m, 높이 0.9 m이고 벽면이 아크릴로 된 직사각형 가변 경사 개수로 실험 장치를 이용하였다. 수로경사는 0.5 %, 실험 식생의 밀도는 4.4 %로 고정하고, 실험유량을 $0.03{\sim}0.04\;m^3/s$, 수심(h)과 홍수터 폭(w)의 비(h/w)를 1.2, 1.7, 2.2로 변화시키면서 실험을 실시하였다. 실험결과 최대 수심변화는 유량이 $0.04\;m^3/s$이고 수심/홍수터 폭 비가 1.2일때 약 4 %로 측정되었고, 저수로에서의 유속의 증가 범위는 단면 평균유속에 비교하여 약 $50{\sim}85\;%$로 확인되었다. 이는 복단면에서의 저수로 유속은 홍수터에 식재가 되었을 경우가 그렇지 않은 경우에 비해 더욱 빨라짐을 의미한다. 따라서 복단면의 홍수터에 교목을 식재할 경우에는 식재에 의한 수위상승 영향 보다는 저수로에서의 유속증가에 더 많은 관심을 가질 필요가 있다고 판단된다.

  • PDF

Parametric optimization of an inerter-based vibration absorber for wind-induced vibration mitigation of a tall building

  • Wang, Qinhua;Qiao, Haoshuai;Li, Wenji;You, Yugen;Fan, Zhun;Tiwari, Nayandeep
    • Wind and Structures
    • /
    • v.31 no.3
    • /
    • pp.241-253
    • /
    • 2020
  • The inerter-based vibration absorber (IVA) is an enhanced variation of Tuned Mass Damper (TMD). The parametric optimization of absorbers in the previous research mainly considered only two decision variables, namely frequency ratio and damping ratio, and aimed to minimize peak displacement and acceleration individually under the excitation of the across-wind load. This paper extends these efforts by minimizing two conflicting objectives simultaneously, i.e., the extreme displacement and acceleration at the top floor, under the constraint of the physical mass. Six decision variables are optimized by adopting a constrained multi-objective evolutionary algorithm (CMOEA), i.e., NSGA-II, under fluctuating across- and along-wind loads, respectively. After obtaining a set of optimal individuals, a decision-making approach is employed to select one solution which corresponds to a Tuned Mass Damper Inerter/Tuned Inerter Damper (TMDI/TID). The optimization procedure is applied to parametric optimization of TMDI/TID installed in a 340-meter-high building under wind loads. The case study indicates that the optimally-designed TID outperforms TMDI and TMD in terms of wind-induced vibration mitigation under different wind directions, and the better results are obtained by the CMOEA than those optimized by other formulae. The optimal TID is proven to be robust against variations in the mass and damping of the host structure, and mitigation effects on acceleration responses are observed to be better than displacement control under different wind directions.

A Study on Typhoon-Disasers in the Korean Peninsula (한반도의 태풍피해에 관한 연구)

  • 유희정
    • Magazine of the Korean Society of Agricultural Engineers
    • /
    • v.25 no.4
    • /
    • pp.61-68
    • /
    • 1983
  • In order to study the disaster of typhoons which hit the Korean peninsula a period of 22 years from 1959 through 1980 was covered to collect necessary data with respect to attack of typhoons and their damage. Centering around the Korean peninsula, typhoons which attacked between 1959 and 1980 were grouped according to their treking routes and damage for detailed analyses. The results are summarized as follows: 1. The average annual damage of typhoons in the Korean peninsula was found to be 1.27 from June to September. The monthly distributions were found to be 53.6% in August, 28.6% in September and 14.2% in July. 2. About an half (56.4%) of the typhoons which hit the Korean peninsula passed through the western coast and 27.3% through the southern and 14.6% through the eastern. Typhoons of the we8tern coast were divided by their treking routes as 25.5% in CWE type (Jul., Aug., Sep.), 14.6% in WE type (Jul., Aug.), 16.3% in W type (Jul.). 3. The minimum SLP averaged 976.6mb and ordere:l by the treking routes as E$_1$$_1$ and CWE types are higher 20mb than S, E or WE types. 4. The Korean peninsula was damaged by all number of the typhoons in WE or S type, by a third at number of its in E or WE and WI type. 5. The annual probabilities of typhoon-disasters were 0.773 for once or more, 0. 409 for twice or more, and 0.091 for three times or more. Hearvy damage experienced in the Korean peninsula are found to have an annual. 6. Amount of the damage by the treking routes in ordered S>WE>CWE>E>W$_1$, and heavy storms experienced in the Xorean peninsula are found to have accompanied the WE and S types during the months of August and September. 7. The average annual damages were found to be 110 at the death-tall, 45, 000 at the sufferers and 10.5 billion at the property damage. 8. Seventy-sex percent of the all damage in the Korean peninsula distributed on the district from the 36th Parallel south and included Chie Ju island.

  • PDF

Fertilization and Embryo Development in Pollination and Culture for Interspecific and Intergeneric Crossing of Forage Crops (기내 수분과 배양에 의한 화본과 사료작물 종속간 수정과 배의 발육)

  • 이호진;한지연
    • KOREAN JOURNAL OF CROP SCIENCE
    • /
    • v.32 no.4
    • /
    • pp.455-461
    • /
    • 1987
  • The ovaries or the ovules of grasses were pollinated and cultured in vitro to raise the interspecific or the intergeneric hybrids between tall fescue, meadow fescue, and Italian ryegrass. The isolated and suface-sterili-zed pistils were dusted with compatible pollens on stigma, on stump after removing stigma, or on excised ovule. Furthermore, the fertilized ovaries and ovules were cultured on MS, M6, or White's media and treated with plant growth regulators: IAA, kinetin, BA to promote embryo development and seed maturity. The in vitro fertilization in grass species ranged from 44 to 92% depending on ovary and pollen parents. The stigmatic pollination was resulted in 67.8% fertilization, the stump pollination 89.0%, and the excised ovule pollination 61.0%, repectively. White's medium was the most effective to provide embryo development and seed maturity in grass species. And the combined treatment of IAA 10mg/$\ell$, kinetin 0.2mg/$\ell$, was better than the non-treatment. Only two seedlings, one complete and one abnormal with root formation were obtained from 127 ovaryies cultured. The anatomy of ovules in vitro cultured was revealed the differentiation of vascular system and meristematic tissue, and the formation of sclerenchyma cells inside ovule.

  • PDF

Image Analysis of Color in Clothes Style (의복스타일별 색채에 대한 이미지 분석)

  • Choi, Jae-Ran;Ryoo, Sook-Hee
    • Journal of the Korean Society of Clothing and Textiles
    • /
    • v.34 no.2
    • /
    • pp.266-279
    • /
    • 2010
  • This research investigates the influence of color as an important factor of the visual image created by clothes. First, the factor analysis of the adjectives describing the images of clothes shows that the images of clothes are classified into 4 factors that include attraction, brightness, femininity, and the figure type (of which the attraction factor and brightness factor were found to be important dimensions). Second, as for the images of feminine style clothes colors, violet appears more refined and attractive than other colors in all 3 tones. Red appears as a brilliant and glowing image in a vivid tone. Yellow in a vivid tone and pale tone, and red in deep tone appear as a warm image, while blue appears as a cold image in all 3 tones. Blue and violet appear as a tall and slim image in all 3 tones. As for the images of mannish style clothes colors, yellow in vivid tone, violet in pale tone and red in deep tone appear as the most refined and attractive image, while green in all the tones appears as a rustic and unattractive image. Red in vivid tone, yellow in pale tone and violet in deep tone appear as a very brilliant and glowing image. Red in pale tone and deep tone appear as a warm and feminine image. Third, yellow in all the tones is evaluated to be attractive in the mannish style in the comparison of the image of feminine and mannish style clothes color, while blue in a pale tone in feminine style and in deep tone in mannish style earned high points. Red and violet did not show any significant differences between the two styles.

Application of the Habitat Evaluation Procedure(HEP) for Legally Protected Wildbirds using Delphi Technique to Environmental Impact Assessment - In case of the Common Kestrel(Falco tinnunculus) in four areas (Paju, Siheung, Ansan, Hwaseong) - (델파이기법을 이용한 법적보호종 서식환경평가의 환경영향평가 적용방안 개발 - 파주시, 시흥시, 안산시, 화성시에서의 황조롱이를 대상으로 -)

  • Lee, Seok-Won;Rho, Paikho;Yoo, Jeong-Chil
    • Journal of Environmental Impact Assessment
    • /
    • v.22 no.3
    • /
    • pp.277-290
    • /
    • 2013
  • This study was carried out to propose the new procedure to apply Habitat Evaluation Procedure(HEP) of target species using delphi technique, which is suitable to develop endangered species with few researches and ecological knowledges. To identify habitat quality of specific species in development project site, we can develop habitat model and create habitat suitability maps. In this study, we select the Common Kestrel(Falco tinnunculus) as target species in four areas(Paju, Siheung, Ansan, Hwaseong) which is located near the Seoul metropolitan area. The Delphi technique was selected to get the reliable information on the species and habitats requirements. Through the delphi approach, seven habitat components were determined as suitable variables for the Common Kestrel: density($n/km^2$) of small mammals, area($km^2$) of bare-grounds, pasturelands and riparian, and open area(%), spatial distribution and area of croplands, landscape diversity, breeding sites(tall trees, cliffs, high-rise buildings), and the length of shelf. Habitat variables used in this model were classified into two categories: % of suitable land-cover type(open areas, croplands, pasturelands, wetlands, and baregrounds) and the quality of feeding sites(within 250m from edges of woodlands). Habitat quality of the Common Kestrel was assessed against occurred sites derived from the nationwide survey. Predicted habitat suitability map were closely related to the observed sites of the endangered avian species in the study areas. With the habitat suitability map of the Common Kestrel, we assess the environmental impacts with habitat loss after development project in environmental impact assessment.

Effects of Feeding High- and Low- Forage Diets Containing Different Forage Sources on Rumen Fermentation Characteristics and Blood Parameters in Non-Pregnant Dry Holstein Cows

  • Peng, Jing Lun;Kim, Byong Wan;Lee, Bae Hun;Nejad, Jalil Ghassemi;Sung, Kyung Il
    • Journal of The Korean Society of Grassland and Forage Science
    • /
    • v.37 no.1
    • /
    • pp.1-9
    • /
    • 2017
  • This research was conducted to investigate the effects of feeding high and low forage diets with different forage sources on rumen fermentation characteristics and blood parameters of Holstein cows during the dry period. Eight Holstein cows were completely randomized assigned to two groups and repeated measurement was utilized in the analysis. Cows in two treatments were fed with diets with high (F:C = 70:30, 70F; forage source: mixed-sowing whole crop barley and Italian ryegrass silage, BIRG) and low (F:C = 55:45, 55F; forage source: tall fescue hay, TF) forage level. Rumen fluid pH was higher in 70F group. Levels of acetic acid, propionic acid, and butyric acid showed a similar pattern: from the lowest value at 07:30 h to the highest at 10:30 h and then decreased in both groups. The ratio of acetic acid to propionic acid was significantly higher (p < 0.05) in 55F group at 09:30 and 10:30 h. Rumen fluid $NH_3-N$ concentrations were significantly higher (p < 0.05) in 70F group at 09:30 and 10:30 h. Blood urea nitrogen was significantly higher (p < 0.05) in 70F group. It was concluded that BIRG based diet with a high forage level had no adverse effects on rumen fermentation, some blood chemical parameters, and immune system in dry Holstein cows and could be used as a forage source instead of imported TF.

Classification of the Somatotypes for the Construction of Young Women's Clothing (Part 1) (청년기 여성의 의복설계를 위한 체형분류 (제1보))

  • 권숙희;김혜경
    • Journal of the Korean Society of Clothing and Textiles
    • /
    • v.20 no.2
    • /
    • pp.282-297
    • /
    • 1996
  • The effective construction for ready-made clothes is one of the central concerns of both consumers and manufactuers in today's apparel industry. In order to reduce the burden of stocks and increase clothing fitness, systematic information on typical body sizes and somatotypes is essential. The purpose of this study i-: to provide basic data on young women's somatotypes for form designers and pattern makers. The subjects of the survey were 310 women of 18 to 26 years old. The study collected 84 anthropometric data for each Person. The data was analyzed by using of the multivariate method. The factor analysis was utilized in regard to the 65 items obtained from anthropometric measurement respectively. The principal component analysis was applied to the data with orthogonal rotation after extraction. The factor scores used in the factor analysis became the basis of determining the value of each variable of the cluster analysis. The cluster analysis was applied for identifying typical somatotypes. Ward's minimum variance method was applied for the purpose of extracting distance metrix by the standardized Euclidean distance. The element forming each cluster can be subdivided into several sets by crosstabulation which is obtained by the fastclus of the SAS. This research has demonstrated 3 distinctive types of silhouette contour of the trunk. Incidentally it also identified 4 of the lower body from the waistline to thigh contour respectively. The discriminant analysis showed that the most significant discriminant factor of the trunk classification were side neck point -1 scapular -1 waistiline length and waist girth. In Korea, the average somatotype of female college students tends to be tall, slim and straight. Reviewing the relationship between the classifications of three parts of body, they are related to each other to some extent but their distribution are not constant. Therefore, in view of clothing construction, a proper separation of the body surface is a necessity.

  • PDF