• Korean Journal of Ecology and Environment
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• v.39 no.3 s.117
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• pp.366-377
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• 2006

Environmental gradients and phytoplankton community were studied on a monthly basis, at 3 stations of Lake Yongdam, from April 2002 March 2004. During July to August, thermocline formed at the depth of about 10 m, but it was lowerd depth, in between 25${\sim}$30 m in October. Monthly variations of the epilimnetic (0${\sim}$5 m) TP concentrations at station 1, 2 and 3 were in the range of $5.1{\sim}36.1\;mg\;P\;{\cdot}\;m^{-3}$, $6.1{\sim}77.7\;mg\;P\;{\cdot}\;m^{-3}$ and $6.7{\sim}47.7\;mg\;P\;{\cdot}\;m^{-3}$ respectively; with higher concentrations at the upstream areas showing. Monthly average of the epilimnetic (0${\sim}$5 m) TN concentration at Station 1 was in the range of $0.88{\sim}1.73\;mg\;N\;{\cdot}\;L^{-1}$, and Station 3 was in the range of $0.94{\sim}2.77\;mg\;N\;{\cdot}\;L^{-1}$, which is higher if compared with the values of station 1. Transparency wa:s in the range of 0.8${\sim}$6.7 m, with lower values at upstream areas and higher at the downstream area. As for phytoplankton, during the winter season, diatoms had high appearance rate; during the spring season, Cyclotella comta, Aulacoseira ambigua f. spiralis, A. granulata and similar diatoms, during spring and summer Ankistrodesmus spiralis, Chodatella subsala, Crucigenia irregularis, Coelastrum cambricum, Scenedesmus ecornis v. ecornis.

• Journal of the Korean Institute of Landscape Architecture
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• v.40 no.4
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• pp.114-126
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• 2012

The purpose of this study is to find ways of the view evaluation of biotope classification before development by selecting an area, which is as large as about $10.0km^2$ around Non Gong Up, Auk Po Myun, Dalsung Gun, Daugu where the large project has been planned, as a subject of this study. The results of this study are as follows. Because of the classification of biotope, there are 23 kinds of types that are subdivided into 140 types. Three surveys for selecting the assessment indicators were performed. The first survey analyzed the importance of 22 selected assessment indicators based on the evaluation of an existing literature review and on the spot research. The second survey performed factor analysis and reclassified the value indicators. The third survey computed additive values of the selected assessment indicators. It used a method of standardizing the average importance of indicators by making their sum equal by 10. Theses additive values were then multiplied by each grade of indicators in order to make a final evaluation. The number of assessment indicators finally selected through the survey of asking specialist is vitality elements, visual obstructs elements etc 19. According to the result of evaluation of 1st, 1 grade spaces which especially valuable is analyzed that 7 spaces, 2 grade spaces for 4, 3 grade spaces for 5, 4 grade space for 2, 5 grade space for 5. Because of the evaluation of 2st, 1 grade spaces which especially valuable(1a, 1b) is analyzed that 15 spaces, 2 grade spaces which valuable is analyzed that 28 space. As the evaluation of site suitability model of this study couldn't have high applicability to other similar area because of having only one site as a subject, it is needed to do synthesize and standardization of various examples to have higher objectivity later.

• Sleep Medicine and Psychophysiology
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• v.10 no.1
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• pp.39-51
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• 2003

Objectives: The Profile of Mood States (POMS) has been used broadly and frequently in various medical studies with various subjects. For the development and application of the Korean edition of POMS, called K-POMS, we translated POMS into Korean and then evaluated the reliability and validity of K-POMS. Methods: The subjects were 161 male students with a mean age of 18.1 years (15-30) and 244 female students with a mean age of 16.6 years (14-23). They were requested to perform K-POMS and SCL-90-R (Korean version) at the same time. Means, reliability coefficients, and test-retest correlations of K-POMS were calculated. Content validities, correlations with SCL-90-R, and discrimination validities in comparison with 76 depressive patients were obtained, and factor analyses were carried out. Results: Mean scores of Total Mood Disturbance (TMD) and some subscales (T, F, C, V factor) showed a significant difference between male and female students. The internal consistency coefficient ($\alpha$) of the total 65 items was 0.93, and ranged from 0.67 to 0.90 for subscales. Test-retest correlations of 43 subjects ranged from 0.27 to 0.63. Seven psychiatrists rated the properness of the content of each item as more than moderate degree (mean scale points=2.66, in the range of 0 to 4). Every subscale of KPOMS exhibited significant correlation with the matching subscale of SCL-90-R. Mean scores of K-POMS of the total 405 subjects were significantly different from those of the 76 depressive subjects after age correction. Six factors were extracted, accounting for 51.2% of total variance. Factor 6 consisted of 6 items which came from various subscales of POMS and represented "uncertainty and helplessness," which may be somewhat different to depression or sadness proper. Conclusion: The validity and reliability of K-POMS could be confirmed. The significant difference in K-POMS scores between depressive subjects and normal subjects suggests that K-POMS can be used clinically for the evaluation and screening of depression. The main structure of K-POMS is very similar to that of POMS, except the Confusion-Bewilderment factor which shows weak factor consistency in K-POMS. This may reflect some emotional characteristic of Koreans such as an undifferentiated aspect of cognitive efficiency. The sixth factor newly extracted from K-POMS also may be indicative of an unique emotional aspect of young Koreans.

• The Journal of Korean Academy of Prosthodontics
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• v.50 no.3
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• pp.162-168
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• 2012

Purpose: Teeth are generally exposed when people smiling. Moreover, the exposed teeth and soft tissue when smiling becomes an important guideline for esthetically prosthetic restoration. This research is to compare and find out differences of Korean young men's smile living in presence and twenty years ago. Materials and methods: Subjects, 100 young men (50 male and 50 female), were required about several aspects; normally developed physical condition, no psychological or genetic disorders, a fine face with no loss of teeth, no experience in orthodontic or prosthetic treatment, relatively normal occlusion, aged between 20-29. The photos of the subject at rest position and front face when fully smiled were taken three times. 100 photos (50 male and 50 female) were chosen at random from the 240 university students' smile photos taken by Yoon and his colleagues in 1991. By Hulsey's method of measuring smile, several factors; the change of upper lip curvature, the change of the relation between the upper lip and teeth, parallelism between Mx. incisor and lower lip, contact relation between Mx. incisor and lower lip and teeth displayed in a smile, were measured and analyzed. Meanwhile, ten dentists assessed aesthetic evaluation about men and women's smile for twice and recorded and compared smile score. The -test (P<.05) was used to compare the measured value. The difference of smile score was analyzed by t-test (P<.05). Results: The smile score calculated in 2011 (60.22) was higher than that of 1991 (52.80). Among five measurement categories, the noticeable difference was distinguished from two factors; the change of upper lip curvature and contact relation between Mx. incisor and lower lip. Conclusion: The Korean young men's smile has been considerably improved for twenty years. And it is found that the change of upper lip curvature plays an important role, that is, the smile formed with an ascended labial commissure has been increased significantly.

• The Magazine of the IEIE
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• v.29 no.6
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• pp.76-80
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• 2002

'Liquid Crystal의 상전이(相轉移)와 광학적 이방성(異方性)이 1888년과 1889년 F. Reinitzer와 O. Lehmann에 의해 Monatsch Chem.과 Z.Physikal.Chem.에 각각 보고된 후 부터 제2차 세계대전이 끝난 뒤인 1950년대 까지는 Liquid Crystal을 단지실험실에서의 기초학문 차원의 연구 대상으로만 다루어 왔다. 1963년 Williams가 Liquid Crystal Device로는 최초로 특허 출원을 하였으며, 1968년 RCA사의 Heilmeier등은 Nematic 액정(液晶)에 저주파(低周波) 전압(電壓)을 인가하면 투명한 액정이 혼탁(混濁)상태로 변화하는 '동적산란(動的散亂)'(Dynamic Scattering) 현상을 이용하여 최초의 DSM(Dynamic Scattering Mode) LCD(Liquid Crystal Display)를 발명하였다. 비록 150V 이상의 높은 구동전압과 과소비전력의 특성 때문에 실용화에는 실패하였지만 Guest-Host효과와 Memory효과 등을 발견하였다. 1970년대에 이르러 실온에서 안정되게 사용 가능한 액정물질들이 합성되고(H. Kelker에 의해 MBBA, G. Gray에 의한 Cyano-Biphenyl 액정의 합성), CMOS 트랜지스터의 발명, 투명도전막(ITO), 수은전지등의 주변기술들의 발전으로 인하여 LCD의 상품화가 본격적으로 이루어지게 되었다. 1971년에는 M. Shadt, W. Helfrich, J.L. Fergason등이 TN(Twisted Nematic) LCD를 발명하여 전자 계산기와 손목시계에 응용되었고, 1970년대 말에는 Sharp에서 Dot Matrix형의 휴대형 컴퓨터를 발매하였다. 이러한 단순 구동형의 TN LCD는 그래픽 정보를 표시하는 데에는 품질의 한계가 있어 1979년 영국의 Le Comber에 의해 a-Si TFT(amorphous Silicon Thin Film Transistor) LCD의 연구가 시작되었고, 1983년 T.J. Scheffer, J. Nehring, G. Waters에 의해 STN(Super Twisted Nematic) LCD가 창안되었고, 1980년 N. Clark, S. Lagerwall 및 1983년 K.Yossino에 의해 Ferroelectric LCD가 등장하여 LCD의 정보 표시량 증대에 크게 기여하였다. Color화의 진전은 1972년 A.G. Ficher의 셀 외부에 RGB(Red, Green, Blue) filter를 부착하는 방안과, 1981년 T. Uchida 등에 의한 셀 내부에 RGB filter를 부착하는 방법에 의해 상품화가 되었다. 1985년에는 J.L. Fergason에 의해 Polymer Dispersed LCD가 발명되었고, 1980년대 중반에 이르러 동화상(動畵像) 표시가 가능한 a-Si TFT LCD의 시제품(試製品) 개발이 이루어지고 1990년부터는 본격적인 양산 시대에 접어들게 되었다. 1990년대 초에는 STN LCD의 Color화 및 대형화(大型化) 고(高)품위화에 힘입어 Note-Book PC에 LCD가 본격적으로 적용이 되었고, 1990년대 후반에는TFT LCD의 표시품질 대비 가격경쟁력 확보로 인하여 Note-Book PC 시장을 독점하기에 이르렀다. 이후로는 TFT LCD의 대형화가 중요한 쟁점으로 부각되고 있고, 1995년 삼성전자는 당시 세계최대 크기의 22' TFT LCD를 개발하였다. 또한 LCD의 고정세(高情細)화를 위해 Poly Si TFT LCD의 개발이 이루어졌고, 디지타이져 일체형 LCD의 상품화가 그 응용의 폭을 넓혔으며, LCD의 대형화를 위해 1994년 Canon에 의해 14.8', 21' 등의 FLCD가 개발되었다. 대형화 방안으로 Tiled LCD 기술이 개발되고 있으며, 1995년에 Sharp에 의해 21' 두장의 Panel을 이어 붙인 28' TFT LCD가 전시되었고 1996년에는 21' 4장의 Panel을 이어 붙인 40'급 까지의 개발이 시도 되었으며 현재는 LCD의 특성향상과 생산설비의 성능개선과 안정적인 공정관리기술을 바탕으로 삼성전자에서 단패널 40' TFT LCD가 최근에 개발되었다. Projection용 디스플레이로는 Poly-Si TFT LCD를 이용하여 $25'{\sim}100'$사이의 배면투사형과 전면투사형 까지 개발되어 대형 TV시장을 주도하고 있다. 21세기 디지털방송 시대를 맞아 플라즈마디스플레이패널(PDP) TV, 액정표시장치 (LCD)TV, 강유전성액정(FLCD) TV 등 2005년에 약 1500만대 규모의 거대 시장을 형성할 것으로 예상되는 이른바 '벽걸이TV'로 불리는 차세대 초박형 TV 시장을 선점하기 위하여 세계 가전업계들이 양산에 총력을 기울이고 있다. 벽걸이TV 시장이 본격적으로 형성되더라도 PDP TV와 LCD TV가 직접적으로 시장에서 경쟁을 벌이는 일은 별로 없을 것으로 보인다. 향후 디지털TV 시장이 본격적으로 열리면 40인치 이하의 중대형 시장은 LCD TV가 주도하고 40인치 이상 대화면 시장은 PDP TV가 주도할 것으로 보는 시각이 지배적이기 때문이다. 그러나 이러한 직시형 중대형(重大型)디스플레이는 그 가격이 너무 높아서 현재의 브라운관 TV를 대체(代替)하기에는 시일이 많이 소요될 것으로 추정되고 있다. 그 대안(代案)으로는 비교적 저가격(低價格)이면서도 고품질의 디지털 화상구현이 가능한 고해상도 프로젝션 TV가 유력시되고 있다. 이러한 고해상도 프로젝션 TV용으로 DMD(Digital Micro-mirror Display), Poly-Si TFT LCD와 LCOS(Liquid Crystals on Silicon) 등의 상품화가 진행되고 있다. 인터넷과 정보통신 기술의 발달로 휴대형 디스플레이의 시장이 예상 외로 급성장하고 있으며, 요구되는 디스플레이의 품질도 단순한 문자표시에서 그치지 않고 고해상도의 그래픽 동화상 표시와 칼라 표시 및 3차원 화상표시까지 점차로 그 영역이 넓어지고 있다. <표 1>에서 보여주는 바와 같이 LCD의 시장규모는 적용분야 별로 지속적인 성장이 예상되며, 새로운 응용분야의 시장도 성장성을 어느 정도 예측할 수 있다. 따라서 LCD기술의 연구개발 방향은 크게 두가지로 분류할 수 있으며 첫째로는, 현재 양산되고 있는 LCD 상품의 경쟁력강화를 위하여 원가(原價) 절감(節減)과 표시품질을 향상시키는 것이며 둘째로는, 새로운 타입의 LCD를 개발하여 기존 상품을 대체하거나 새로운 시장을 창출하는 분야로 나눌 수 있다. 이와 같은 관점에서 현재 진행되고 있는 LCD기술개발은 다음과 같이 분류할 수 있다. 1) 원가 절감 2) 특성 향상 3) New Type LCD 개발.

• Journal of Environmental Science International
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• v.23 no.12
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• pp.2045-2056
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• 2014

In this study, pressure drop was measured in the pulse jet bag filter without venturi on which 16 numbers of filter bags (Ø$140{\times}850{\ell}$) are installed according to operation condition(filtration velocity, inlet dust concentration, pulse pressure, and pulse interval) using coke dust from steel mill. The obtained 180 pressure drop test data were used to predict pressure drop with multiple regression model so that pressure drop data can be used for effective operation condition and as basic data for economical design. The prediction results showed that when filtration velocity was increased by 1%, pressure drop was increased by 2.2% which indicated that filtration velocity among operation condition was attributed on the pressure drop the most. Pressure was dropped by 1.53% when pulse pressure was increased by 1% which also confirmed that pulse pressure was the major factor affecting on the pressure drop next to filtration velocity. Meanwhile, pressure drops were found increased by 0.3% and 0.37%, respectively when inlet dust concentration and pulse interval were increased by 1% implying that the effects of inlet dust concentration and pulse interval were less as compared with those changes of filtration velocity and pulse pressure. Therefore, the larger effect on the pressure drop the pulse jet bag filter was found in the order of filtration velocity($V_f$), pulse pressure($P_p$), inlet dust concentration($C_i$), pulse interval($P_i$). Also, the prediction result of filtration velocity, inlet dust concentration, pulse pressure, and pulse interval which showed the largest effect on the pressure drop indicated that stable operation can be executed with filtration velocity less than 1.5 m/min and inlet dust concentration less than $4g/m^3$. However, it was regarded that pulse pressure and pulse interval need to be adjusted when inlet dust concentration is higher than $4g/m^3$. When filtration velocity and pulse pressure were examined, operation was possible regardless of changes in pulse pressure if filtration velocity was at 1.5 m/min. If filtration velocity was increased to 2 m/min. operation would be possible only when pulse pressure was set at higher than $5.8kgf/cm^2$. Also, the prediction result of pressure drop with filtration velocity and pulse interval showed that operation with pulse interval less than 50 sec. should be carried out under filtration velocity at 1.5 m/min. While, pulse interval should be set at lower than 11 sec. if filtration velocity was set at 2 m/min. Under the conditions of filtration velocity lower than 1 m/min and high pulse pressure higher than $7kgf/cm^2$, though pressure drop would be less, in this case, economic feasibility would be low due to increased in installation and operation cost since scale of dust collection equipment becomes larger and life of filtration bag becomes shortened due to high pulse pressure.

• Asian-Australasian Journal of Animal Sciences
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• v.29 no.4
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• pp.500-508
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• 2016

This study was conducted to investigate the effects of Momordica charantia saponin (MCS) on ruminal fermentation of maize stover and abundance of selected microbial populations in vitro. Five levels of MCS supplements (0, 0.01, 0.06, 0.30, 0.60 mg/mL) were tested. The pH, $NH_3-N$, and volatile fatty acid were measured at 6, 24, 48 h of in vitro mixed incubation fluids, whilst the selected microbial populations were determined at 6 and 24 h. The high dose of MCS increased the initial fractional rate of degradation at t-value = 0 ($FRD_0$) and the fractional rate of gas production (k), but decreased the theoretical maximum of gas production ($V_F$) and the half-life ($t_{0.5}$) compared with the control. The $NH_3-N$ concentration reached the lowest concentration with 0.01 mg MCS/mL at 6 h. The MSC inclusion increased (p<0.001) the molar proportion of butyrate, isovalerate at 24 h and 48 h, and the molar proportion of acetate at 24 h, but then decreased (p<0.05) them at 48 h. The molar proportion of valerate was increased (p<0.05) at 24 h. The acetate to propionate ratio (A/P; linear, p<0.01) was increased at 24 h, but reached the least value at the level of 0.30 mg/mL MCS. The MCS inclusion decreased (p<0.05) the molar proportion of propionate at 24 h and then increased it at 48 h. The concentration of total volatile fatty acid was decreased (p<0.001) at 24 h, but reached the greatest concentration at the level of 0.01 mg/mL and the least concentration at the level of 0.60 mg/mL. The relative abundance of Ruminococcus albus was increased at 6 h and 24 h, and the relative abundance of Fibrobacter succinogenes was the lowest (p<0.05) at 0.60 mg/mL at 6 h and 24 h. The relative abundance of Butyrivibrio fibrisolvens and fungus reached the greatest value (p<0.05) at low doses of MCS inclusion and the least value (p<0.05) at 0.60 mg/mL at 24 h. The present results demonstrates that a high level of MCS quickly inhibits in vitro fermentation of maize stover, while MCS at low doses has the ability to modulate the ruminal fermentation pattern by regulating the number of functional rumen microbes including cellulolytic bacteria and fungi populations, and may have potential as a feed additive applied in the diets of ruminants.

• Economic and Environmental Geology
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• v.37 no.5
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• pp.477-497
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• 2004

In the Hongseong and Kwangcheon areas, two ultramafic rocks are exposed as isolated bodies in the Precambrian Kyeonggi gneiss complex. The ultramafic rocks extend for several hundred meters to NNE direction and are contact with adjacent metasediments by steeply dipping faults. The rocks are dunite or harzburgite showing dominantly equigranular-mosaic and protogranular textures with a minor amount of porphyroclastic textures. They contain varying amounts of fosteritic olivine (F$o_{0.91-0.93}$), magnesian pyroxene (E$n_{0.89-0.93}$) and tremolitic to magnesian hornblende with minor amounts of spinel, serpentine, chlorite, magnetite, phlogopite and talc. The rocks are in contrast with adjacent gneiss complex or metabasite (amphibole, biotite, plagioclase, alkali-feldspar and quartz). Geochemically, these ultramafic rocks are characterized by high magnesium number (M$g_#$> 0.88) and transitional element (mainly, Ni>1716 ppm, Cr>1789 ppm), low alkali element (e.g. $K_2$O<0.09 wt.%, Na$_2$O<0.19 wt.%) and depletion of incompatible elements. The calculated correlation coefficients showed good positive correlations among the ferrous (e.g. Sc, V, Zn) elements, incompatible elements (e.g. REE), and among SiO$_2$ or $Al_2$O$_3$ with ferrous elements, whereas negative correlations are appeared between Ni and major elements. These results involve increasing of the ferrous- and $Al_2$O$_3$-bearing minerals(e.g. amphibole and mica) with decreasing of Mg-bearing minerals (e.g. olivine) depending on the degree of alteration. Calculated geothermometries and mineral assemblages suggest that the ultramafic rocks have been metamorphosed through the condition from the greenschist to amphibolite facies. Compared with ultramafic rocks elsewhere, it is thought that those of the Hongseong and Kwangcheon areas are derivatives of the depleted sources since they are depleted in incompatible elements including REE abundances. Moreover overall characteristics of the ultramafic rocks are similar to the those of orogenic related Alpine type ultramafic rocks, especially, shallow mantle slab varieties.

• Korean Journal of Plant Taxonomy
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• v.45 no.1
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• pp.96-107
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• 2015

This study presents a comprehensive account of the flora of hydrophytes and hygrophytes on Jeju Island. This approach aims to contribute to fundamental information about the conservation of plant diversity in wetlands. Field surveys were carried out from May of 2010 to September of 2014 in various types of wetlands on Jeju Island. A total of 189 taxa, including 52 families, 98 genera, 181 species, 6 varieties, 2 forma and 189 taxa, were found. Among them, 99 taxa (38 families, 60 genera, 96 species and 3 varieties) were hydrophytes and 90 taxa (23 families, 45 genera, 85 species, 3 varieties and 2 forma) were hygrophytes. In addition, Eleocharis${\times}$yezoensis H. Hara (Cyperaceae) was newly added to the flora of Korea. The protected wild plants designated by the Ministry of the Environment were 5 taxa, including Brasenia schreberi J. F. Gmel. and Dysophylla yatabeana Makino. The endangered species found included one Critically Endangered Species (i.e., Mankyua chejuense B.-Y. Sun, M. H. Kim & C. H. Kim), 5 Endangered Species (e.g., Lysimachia leucantha Miq.) and 7 Vulnerable Species (e.g., Tillaea aquatica L.). The floristic regional indicator plants found in this area were 44 taxa comprising 10 taxa of grade V, 7 taxa grade IV, 15 taxa of grade III, 5 taxa of grade II, and 7 taxa of grade I. The identified naturalized plants were 10 taxa; 8 families, 8 genera, 9 species and 1 variety. In the wetlands on Jeju Island, high plant species diversity was shown, and a number of rare plants and phytogeographically important plants were found. For these reasons, we consider that the wetlands on Jeju Island are very important areas from a botanical point of view. It is necessary to establish specific protection and maintenance policies in an effort to conserve these wetlands and species.

• Journal of the Korea Concrete Institute
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• v.23 no.6
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• pp.711-722
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• 2011

Beam-column gravity or Intermediate Moment frames subjected to unexpected large displacements are vulnerable when no seismic details are provided, which is typical. Conversely, economic efficiency of those frames is decreased if unnecessary special detailing is applied as the beam and column size becomes quite large and steel congestion is caused by joint transverse reinforcement in beam-column connections. Moderate seismic design is used in Korea for beam-column connections of buildings with structural walls, which are to be destroyed when the unexpected large earthquake occurs. Nonetheless, performance of such beamcolumn connections may be substantially improved by the addition of steel fibers. This study was conducted to investigate the effect of steel fibers in reinforced concrete exterior beam-column connections and possibility for the replacement of some joint transverse reinforcement. Ten half-scale beam-column connections with non-seismic details were tested under cyclic loads with two cycles at each drift up to 19 cycles. Main test parameters used were the volume ratio of steel fibers (0%, 1%, 1.5%) and joint transverse reinforcement amount. The test results show that maximum capacity, energy dissipation capacity, shear strength and bond condition are improved with the application of steel fibers to substitute transverse reinforcement of beam-column connections. Furthermore, several shear strength equations for exterior connections were examined, including the proposed equation for steel fiber-reinforced concrete exterior connections with non-seismic details.