• Korean Journal of Plant Taxonomy
• /
• v.46 no.3
• /
• pp.288-294
• /
• 2016

The Vietnamese occurrence of Stephania subpeltata H. S. Lo (Menispermaceae) is reported here for the first time. It is morphologically allied to S. japonica but differs in having subpeltate, ovate deltoid or broadly deltoid to subdeltoid leaves, shorter petiole, fewer leaf veins, conspicuously pedicellate umbelliform cymes which are seldom compound, and purple flowers and endocarp with a reduced number of abaxial rows. A taxonomic description, distribution details, ecology, and a key to the Vietnamese species of Stephania are provided.

• Advances in concrete construction
• /
• v.9 no.5
• /
• pp.459-467
• /
• 2020

Mechanical and thermal properties of composite sandwich wall panels are affected by changes in their external environment. Humidity and temperature changes induce stress on wall panels and their core connectors. Under the action of ambient temperature, temperature on the outer layer of the wall panel changes greatly, while that on the inner layer only changes slightly. As a result, stress concentration exists at the intersection of the connector and the wall blade. In this paper, temperature field and stress field distribution of UHPC-RW-RC (Ultra-High Performance Concrete - Rock Wool - Reinforced Concrete) wall panel under high temperature-sprinkling and heating-freezing conditions were investigated by using the general finite element software ABAQUS. Additionally, design of the connection between the wall panel and the main structure is proposed. Findings may serve as a scientific reference for design of high performance composite sandwich wall panels.

• Parasites, Hosts and Diseases
• /
• v.59 no.1
• /
• pp.1-8
• /
• 2021

Leptotrombidium scutellare is one of the 6 main vectors of scrub typhus in China. It has been found in more than 15 provinces of China. Especially in Yunnan, it was found to be mainly distributed in some mountainous areas with high altitude, low temperature and low precipitation. Rodents and some other small mammals were the most common hosts of L. scutellare. To date, more than 40 host species of L. scutellare have been recorded with very low host specificity, and the main hosts varied in different geographical regions. L. scutellare had a strong resistance against the cold environment, and the temperature and humidity were 2 important factors affecting its growth and development. Among different individuals of their rodent hosts, L. scutellare mites often showed an aggregated distribution pattern, which reflected the interspecific cooperation of the mites. The chromosome karyotype of L. scutellare was 2n=16 and all the 8 pairs of chromosomes were short rod-shaped with metacentric or sub-metacentric types. The isozyme spectrum supported that L. scutellare, L. deliense and L. rubellum were in the same species group. Based on the natural infection, experimental transmission and epidemiological evidence, L. scutellare has been eventually confirmed as the second major vector of scrub typhus in China, which is second only to L. deliense.

• Steel and Composite Structures
• /
• v.44 no.3
• /
• pp.407-421
• /
• 2022

Prefabricated hybrid wind turbine towers (WTTs) are promising due to height increase. This study proposes the use of ultra-high performance concrete (UHPC) to develop a new type of WTT without the need to use reinforcement. It is demonstrated that the UHPC WTT structure without reinforcing bars could achieve performance similar to that of reinforced concrete WTTs. To simplify the design of WTT, a design approach for the calculation of stresses at the horizontal joints of a WTT is proposed. The stress distribution near the region of the horizontal joint of the WTT structure under normal operating conditions and different load actions is studied using the proposed approach, which is validated by the finite element method. A further parametric study shows that the degree of prestressing and the bending moment both significantly affect the principal stress. The shear-to-torsion ratio also shows a significant influence on the principal tensile stress.

• The Journal of Industrial Distribution & Business
• /
• v.10 no.1
• /
• pp.9-17
• /
• 2019

Purpose - Urban agglomeration construction is one of national strategic plans to accelerate the development of industrialization and urbanization in China, which has threatened the eco-environmental quality at the same time. This paper selected the urban agglomeration in the middle reaches of the Yangtze River as the research area. Research design, data, and methodology - The the slack-based measurement (SBM) model considering undesirable outputs is applied to measure the eco-efficiency of this urban agglomerations during 2006-2015. Results - The empirical results show that average eco-efficiency of the urban agglomeration in the middle reaches of the Yangtze River is 0.595. Regional ecological development is unbalanced. The highest eco-efficiency is recorded at Wuhan Metropolitan Area, and the lowest one is at the Changsha-Zhuzhou-Xiangtan City Group. Energy consumption and waste dust emissions are the key factors led to ecological inefficiency. Based on this, potentials for energy saving and waste dust reducing are calculated. Conclusions - Finally, this study provides policy implications targeted to promote the coordinating development of economy and eco-environment under the construction of urban agglomeration.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
• /
• v.23 no.7
• /
• pp.560-565
• /
• 2010

This paper presents the design factor of an overhead transmission tower structure in order to reduce the tower weight. The behaviour of transmission tower structures are affected by the horizontal angle of the tower structure, the equivalent wind pressure group, the slope of the main post of the tower, the separation of the internode and the use of high-strength materials in their construction. Tower weight can be reduced by approximately 30% reduce weight by means of optimal design based on a consideration of all the above factors. In addition, the design of the foundation of the tower with the shear key installation to increase horizontal support together with a modified angle of inclination to the ground can reduce by about 37% the amount of concrete used during construction. The area of ground disturbed by the construction of the tower foundation can thus be reduced by approximately 33%. Therefore it is possible to build an environmently-friendly T/L tower with the mechanical properties of existing towers.

• Proceedings of the Korea Information Processing Society Conference
• /
• 2006.05a
• /
• pp.995-998
• /
• 2006

IGMP(Internet Group Management Protocol)는 멀티캐스트 그룹의 멤버쉽 관리를 위한 프로토콜로서, 임의의 호스트가 멀티캐스트 라우터에게 특정한 멀티캐스트 통신의 수신을 요청할 경우에 사용된다. 본 논문에서는 이와 같은 IGMP 메시지를 이용한 정당하지 않은 호스트의 DoS 공격 등으로부터 멀티캐스트 분배트리의 보호를 위한 수신자 접근제어 기법을 제안한다. 또한 제안기법은 수신자 접근제어 기능뿐만 아니라, 실제 다양한 상업적인 멀티캐스트 서비스에도 적용될 수 있는 비즈니스 모델을 기반으로 하며 과금과 관련하여 활용이 가능하다.

• Proceedings of the Korean Society of Computer Information Conference
• /
• 2009.01a
• /
• pp.373-376
• /
• 2009

최근 네트워크 기술의 발전에 의해 VoIP, IP-TV 등 다양한 서비스들이 등장하였다. 이러한 실시간 서비스들은 품질을 보장하면서 통신 내용을 안전하게 보호할 수 있는 보안 메커니즘이 필수적이다. 우리는 VoIP를 이용한 다자간 통화 및 화상 회의, 그리고 IP-TV와 같은 그룹 기반의 서비스들을 안전하고 효율적으로 보호하기 위한 그룹 카 분배 프로토콜을 제안한다. 제안하는 프로토콜은 빠르고 효율적인 연산만으로 구성되었으며, 그룹 내부 및 외부의 공격으로부터 그룹 키를 안전하게 보호한다. 성능평가 및 분석 결과는 제안하는 프로토콜이 최근에 연구된 다른 프로토콜들에 비해 안전하고 효율적임을 증명하였다.

• Genomics & Informatics
• /
• v.4 no.4
• /
• pp.182-187
• /
• 2006

6-Phosphogluconolactonase (6PGL) is one of the key enzymes in the ubiquitous pathways of central carbon metabolism, but bacterial 6PGL had been long known as a missing enzyme even after complete bacterial genome sequence information became available. Although recent experimental characterization suggests that there are two types of 6PGLs (DevB and YbhE), their phylogenetic distribution is severely biased. Here we present that proteins in COG group previously described as 3-oarboxymuconate cyclase (COG2706) are actually the YbhE-type 6PGLs, which are widely distributed in Proteobacteria and Fimicutes. This case exemplifies how erroneous functional description of a member in the reference database commonly used in transitive genome annotation cause systematic problem in the prediction of genes even with universal cellular functions.

• 한국정보디스플레이학회:학술대회논문집
• /
• 2005.07a
• /
• pp.167-170
• /
• 2005

The mechanism of striation in the coplanar- and matrix-type plasma display panel (PDP) cells has been studied using the particle-in-cell Monte-Carlo Collision (PIC-MCC) model. The striation formation is related to the ionization energy of neutral atoms and the well-like deformation of space potential by space charge distribution. Negative wall charge accumulation by electrons on the MgO surface of the anode region is also one of the key factors for the formation of striation. The clearness of the striation phenomenon in PIC-MCC code in comparison with fluid code can be explained by using nonlocal electron kinetic effect.