• Title/Summary/Keyword: toad

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The incidence of abnormalities in the fire-bellied toad, Bombina orientalis, in relation to nearby human activity

  • Kang, Changku;Shin, Yujin;Kim, Ye Eun;Moon, Jongyeol;Kang, Jae Yeon;Jang, Yikweon
    • Journal of Ecology and Environment
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    • v.39 no.1
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    • pp.11-16
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    • 2016
  • Declines in amphibian populations are occurring worldwide, and have been attributed to many factors, including anthropogenic environmental changes. One of the ramifications of such declines is abnormalities in many amphibian species. A strong association has been detected between human activities and abnormalities in amphibian populations, but studies on this association are largely focused on lentic species. In this study, it was analyzed whether the degree of local human activity was associated with the rate of abnormalities in Bombina orientalis which inhabited lotic environments. We found that the proportions of abnormalities in wild populations of B. orientalis increased, when i) the closest human land use was located within 100 m from the frogs' habitat, and ii) the proportion of human land use within a 300-m radius was high. Our findings suggest that human activity has a negative impact on the fitness of nearby amphibian populations, and that wild populations very close to human-induced disturbance are affected.

A Study on the Symbolical Significance in Korean Kasa - Focusing on the embroideries - (한국가사의 상징성에 대한연구 -가사에 나타난 문양을 중심으로-)

  • Lee Soon Duk
    • Journal of the Korean Society of Clothing and Textiles
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    • v.16 no.2
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    • pp.189-195
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    • 1992
  • Buddhism as one of alien thoughts has been developed conflicting and fusing with Korean Cultural bases. From these fusion process Korean Kasa (i.e, sacerdotal robe for Buddhist monk) also came into possession of different features from original Kasa which Buddhist Command- ment regulates or Kasa of South Asia which is the birthplace of Buddhism. 1. Original kasa was Pamsukula (i.e., a shabby, abandoned, muddy cloth), which did not permit special ornament or luxurious materal. However, we can find splendid colors, letters and embroideries in Korean Kasa. 2. These phenomenon originated from Three Treasures Faith, that is to say, the faith for three treasures, such as Buddha, Buddhist Commandment and Buddhist monk, which was formed by the fusion of Buddhism and conventional Shamanism. 3. Such letters as 천(Heaven), 왕(God). 영(om) stand for what shaped Guardian Deities protecting buddhist Sanctum. 4. The rmbroideries of three-legged bird, such as rabbit and toad, which symbolyze 일(sun) and 월(moon) stand for what shaped conventional divinities. 5. After Kasa possessing originally practical significance, such as Kasa Charity, was penetrated into Korea, it became the object of faith, possessing symbolical significance in addition.

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The Cutaneous Xanthophore Differentiation in Bombina orientalis (무당개구리(Bombina orientalis Boulenger)皮膚 黃色素細胞(Xanthophore)의 分化에 관한 硏究)

  • 문명진;김우갑;김창환
    • The Korean Journal of Zoology
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    • v.29 no.4
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    • pp.261-271
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    • 1986
  • The cutaneous xanthophore differentiation from larvae to adult in Bombina orientalis-the Korean fire bellied toad-is studied with light and electron microscopes. General structure of adult xanthophore which is composed of many pterinosomes and a small quantity of carotenoid vesicles is forming chromatophore complex with other dermal pigment cells. And the cytoplasmic process of xanthophore is distributed just beneath the basement membrane. The first differentiated xanthophore is originated from both rER rich cells and Golgi complex rich cells before and after the feeding larval stage. Formation of the pigment granule is proceeded gradually along the sequental metamorphic stages. After the metamorphosis, rapid multiplication of pterinosome is observed and enlargement of carotenoid vesicle is appeared after hybernation. These pigment granules are seen several structures by the differentiated level.

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Characteristics of Forming toad in Forward and Backward Can Extrusion Processes (전ㆍ후방 캔 압출공정의 성형하중특성)

  • Choi H. J;Ham B. S;Ok J. H;Shim J. H;Kim S. H;Hwang B. B
    • Transactions of Materials Processing
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    • v.13 no.8
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    • pp.689-695
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    • 2004
  • This paper is concerned with the analysis of the forming load characteristics of a forward-backward can extrusion process. The analysis in this paper is extended to the selection of press frame capacity for producing efficiently final product at low cost. The possible extrusion processes to shape a forward-backward can part with different outer diameters are categorized to investigate quantitatively the forming load, forming energy and maximum pressure exerted on the die-material interface. The categorized processes are composed of combined and/or some basic extrusion processes. After the analysis of the forming load characteristics, the frame capacity of press suitable for a selected process could be determined along with securing the load capacity and with considering productivity. In addition, it is also suggested that different load capacities be selected for different dimensions of a part such as the wall thickness in forward direction. The work in this paper could be a good reference for analysis of complex extrusion and selection of proper frame capacity of press to achieve low production cost and thus high productivity.

Correction of Mean Phase Error for OFDM and SC-CP Systems using Decision-Directed Method (OFDM 및 SC-CP 시스템에 대한 결정지향 방식의 평균위상에러 정정)

  • Kim Ji-Heon;Kim Whan-Woo
    • Journal of the Institute of Electronics Engineers of Korea TC
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    • v.42 no.12
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    • pp.77-84
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    • 2005
  • The orthogonal frequency division multiplexing (OFDM) technique and the single carrier with cyclic prefix (SC-CP) scheme are very attractive solutions for wireless applications, being computationally efficient since equalization is performed in the frequency domain. The equalizer could not entirely handle significant mean. Doppler shift. This motivates the use of a phase error tracking loop that operates jointly with the frequency equalizer. This paper describes the effect of the mean phase error and the performance of the proportional equalizer coupled with a phase error tracking loop based on decision-directed method. Furthermore, simulation results show that we can reduce the computational toad of the tracking loop with minimal performance degradation.

Analytical Study on the fatigue Behavior of Reinforced Concrete Bridge Piers under Earthquake (지진시 철근콘크리트 교각의 피로거동에 관한 해석적 연구)

  • 김태훈;이상철;신현목
    • Journal of the Korea Concrete Institute
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    • v.13 no.4
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    • pp.389-396
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    • 2001
  • This paper presents an analytical prediction of the fatigue behavior of reinforced concrete bridge piers under earthquake. Material nonlinearity is taken into account by comprising tensile, compressive and shear models of cracked concrete and a model of reinforcing steel. The smeared crack approach is incorporated. In boundary plane at which each member with different thickness is connected, local discontinuous deformation due to the abrupt change in their stiffness can be taken into account by introducing interface element. The effect of number of load reversals with the same displacement amplitude has been also taken into account to model the reinforcing steel. The proposed numerical method for fatigue behavior of reinforced concrete bridge piers under earthquake will be verified by comparison with reliable experimental results.

A Dynamic toad Redistribution Using Genetic Algorithm in Heterogeneous Systems (유전 알고리즘을 이용한 이질형 시스템에서의 동적 부하재분배)

  • Lee Seong Hoon
    • Journal of Internet Computing and Services
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    • v.5 no.6
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    • pp.93-101
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    • 2004
  • In a receiver-initiated load redistribution algorithm, receiver(underloaded processor) continues to send unnecessary request messages for load transfer until a sender(overloaded processor) is found while the system load is light, Therefore, it yields many problems such as low cpu utilization and system throughput because of inefficient inter-processor communications until the receiver receives an accept message from the sender in this environment. This paper presents an approach based on genetic algorithm(GA) for dynamic load redistribution in heterogeneous distributed systems. In this scheme the processors to which the requests are sent off are determined by the proposed GA to decrease unnecessary request messages. The performance of proposed algorithm shows better than that of the conventional algorithm through various experiments.

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Modeling and Parametric Studies on Moment-Curvature Relation of a Reinforced Concrete Column Subject In Axial-toad and Bi-Axil Moment (축하중과 이축모멘트를 받는 철근콘크리트 기둥의 모멘트-곡률에 관한 모델링 및 변수고찰)

  • 이차돈;최기봉;차준실;김성진
    • Journal of the Korea Concrete Institute
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    • v.14 no.5
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    • pp.677-688
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    • 2002
  • A analytical model is developed which can simulate a complete inelastic biaxial moment-curvature relations of a reinforced concrete column. The model can simulate sudden drop in moment capacity after peak moment and due to spalling of cover concrete. Parametric studies are performed examine the effects of constituent material properties as well as topological arrangement of reinforcements on moment-curvature relations and P-M interaction curve. It has been analytically observed that ductility of a reinforced concrete column is influenced mostly by magnitude of the axial load and spacings or the volume of lateral reinforcements. Compared to ACI P-M interaction curve, overall increase about 10% in square root of sum of squares of axial force and moment, and about 20% in peak load are observed for the columns reinforced according to ACI seismic design code.

Behavior of Three Story Bearing Wall Structure under Lateral toad Reversals (반복 수평하중을 받는 3층 철근콘크리트 내력벽 아파트 구조물의 거동 특성)

  • Chang Kuk-Kwan;Oh Young-Hun;Kim Ki-Hyun
    • Journal of the Korea Concrete Institute
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    • v.16 no.5 s.83
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    • pp.627-634
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    • 2004
  • The purpose of this study is to investigate seismic performance of a bearing wall system for apartment buildings. An 1/3 scale three-story specimen was constructed and tested under cyclic lateral loads. The specimen was consisted of pierced walls and coupling elements as well as floor slabs. The bearing wall system is considered to have a adequate deformation capacity up to $2.0\%$ of roof drift ratio, and the experimental results showed the ductile load-deformation characteristics even though some walls were failed in shear Nonlinear analysis was peformed to compare the load-deformation curve obtained from the experimental program. The result of nonlinear analysis could be useful to predict the actual behavior characteristics of the bearing wall system subjected to lateral loads.

An Experimental Study on Optimal Space Rate of Letters within Road Sign (도로표지내 글자간 적정 여백률에 관한 실험적 연구)

  • Lee, Gi-Yeong;Yu, Tae-Ho;Lee, Gun-Sang;O, Yeong-Tae
    • Journal of Korean Society of Transportation
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    • v.24 no.6 s.92
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    • pp.21-32
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    • 2006
  • The purpose of this study is to determine the economical standard for road signs by verifying the difference in driver's legibility time with respect to the spacing of letters on the toad signs. Laboratory simulations were conducted to confirm the difference in legibility time for six target signs of different spacing. Also. a binary logit model was used to find the main factors, which could lower the rate if misreading. This model involves not only a simple enlargement of signs but also a suitable match of letters and signs along with the optimal spacing of the text letters on the road signs to increase the legibility of the sign. The result of this study verified the importance of spacing in road signs and Proved itself to be an effective method to determine the future standard for the road signs.