• Title/Summary/Keyword: combined systems

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Thermodynamics of the Formation of Polymethylbenzene-Halogens Charge Transfer Complexes (IV) (폴리메틸벤젠과 할로겐 사이의 전하이동 착물생성에 관한 열역학적 연구 (제4보))

  • Oh Chun Kwun;Jeong Rim Kim;Je Ha Yang
    • Journal of the Korean Chemical Society
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    • v.26 no.5
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    • pp.274-281
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    • 1982
  • Ultraviolet spectrophotometric investigation have been carried out on the systems of pentamethylbenzene and hexamethylbenzene with iodine and iodine monochloride in carbon tetrachloride. The results reveal the formation of the one to one molecular complexes. The equilibrium constants were obtained in consideration of that absorption maxima due to the formation of the charge transfer complexes shift to blue with the increasing temperature. Thermodynamic parameters for the formation of the charge transfer complexes were calculated from these values. These results indicate that the complex formed between polymethylbenzene and iodine monochloride is more stable than that in the case of iodine. This may be a measure of their relative acidities toward polymethylbenzene, which is explained in terms of the relative electronegativities of halogen atoms. These results combined with previous studies of this series indicated that ${\lambda}_{max}$ shift to red with the increasing number of methyl groups on benezene ring and that the relative stabilities of these complexes increase in the order, Benzene < Toluene < Xylene < Durene < Mesitylene < Pentamethylbenzene < Hexamethylbenzene. The reason for the order found is thus additionally discussed.

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Automatic Construction of Foreign Word Transliteration Dictionary from English-Korean Parallel Corpus (영-한 병렬 코퍼스로부터 외래어 표기 사전의 자동 구축)

  • Lee, Jae Sung
    • The Journal of Korean Association of Computer Education
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    • v.6 no.2
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    • pp.9-21
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    • 2003
  • This paper proposes an automatic construction system for transliteration dictionary from English-Korean parallel corpus. The system works in 3 steps: it extracts all nouns from Korean documents as the first step, filters transliterated foreign word nouns out of them with the language identification method as the second step, and extracts the corresponding English words by using a probabilistic alignment method as the final step. Specially, the fact that there is a corresponding English word in most cases, is utilized to extract the purely transliterated part from a Koreans word phrase, which is usually used in combined forms with Korean endings(Eomi) or particles(Josa). Moreover, the direct phonetic comparison is done to the words in two different alphabet systems without converting them to the same alphabet system. The experiment showed that the performance was influenced by the first and the second preprocessing steps; the most efficient model among manually preprocessed ones showed 85.4% recall, 91.0% precision and the most efficient model among fully automated ones got 68.3% recall, 89.2% precision.

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Delamination evaluation on basalt FRP composite pipe by electrical potential change

  • Altabey, Wael A.
    • Advances in aircraft and spacecraft science
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    • v.4 no.5
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    • pp.515-528
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    • 2017
  • Since composite structures are widely used in structural engineering, delamination in such structures is an important issue of research. Delamination is one of a principal cause of failure in composites. In This study the electrical potential (EP) technique is applied to detect and locate delamination in basalt fiber reinforced polymer (FRP) laminate composite pipe by using electrical capacitance sensor (ECS). The proposed EP method is able to identify and localize hidden delamination inside composite layers without overlapping with other method data accumulated to achieve an overall identification of the delamination location/size in a composite, with high accuracy, easy and low-cost. Twelve electrodes are mounted on the outer surface of the pipe. Afterwards, the delamination is introduced into between the three layers (0º/90º/0º)s laminates pipe, split into twelve scenarios. The dielectric properties change in basalt FRP pipe is measured before and after delamination occurred using arrays of electrical contacts and the variation in capacitance values, capacitance change and node potential distribution are analyzed. Using these changes in electrical potential due to delamination, a finite element simulation model for delamination location/size detection is generated by ANSYS and MATLAB, which are combined to simulate sensor characteristic. Response surfaces method (RSM) are adopted as a tool for solving inverse problems to estimate delamination location/size from the measured electrical potential changes of all segments between electrodes. The results show good convergence between the finite element model (FEM) and estimated results. Also the results indicate that the proposed method successfully assesses the delamination location/size for basalt FRP laminate composite pipes. The illustrated results are in excellent agreement with the experimental results available in the literature, thus validating the accuracy and reliability of the proposed technique.

Evaluation of the Coefficient of Thermal Expansion of Constituents in Composite Materials using an Inverse Analysis Scheme (역해석기법을 이용한 복합재료 구성성분의 열팽창계수 예측)

  • Lim, Jae Hyuk;Sohn, Dongwoo
    • Journal of the Computational Structural Engineering Institute of Korea
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    • v.27 no.5
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    • pp.393-401
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    • 2014
  • In this paper, we propose an evaluation scheme of the coefficients of thermal expansion (CTE) of constituents in composite materials using an inverse analysis. The size of constituents typically is about a few micrometers, which makes the identification of material properties difficult as well as the measurement results inaccurate. The proposed inverse analysis scheme, which is combined with the Mori-Tanaka method for predicting an equivalent CTE of composite materials, provides the CTE of the constituents in a straightforward manner by minimizing the cost function defined in lamina scale with the steepest descent method. To demonstrate the effectiveness and accuracy of the proposed scheme, the CTEs of several fibers (glass fiber, P75, P100, and M55J) embedded in matrix are evaluated and compared with experimental results. Furthermore, we discuss the effects of uncertainty of laminar and matrix properties on the prediction of fiber properties.

Are the conservation areas sufficient to conserve endangered plant species in Korea?

  • Kang, Hye-Soon;Shin, Sook-Yung;Whang, Hye-Jin
    • Journal of Ecology and Environment
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    • v.33 no.4
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    • pp.377-389
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    • 2010
  • Understanding the factors relevant to endangerment and the patterns of habitat locations in relation to protected areas is critically important for the conservation of rare species. Although 64 plant species have recently been listed as endangered species in Korea, this information has, until now, not been available, making appropriate management and conservation strategies impossible to devise. Thus, we collected information on potentially threatening factors, as well as information on the locations in which these species were observed. The potentially threatening factors were classified into seven categories. National parks, provincial parks, ecosystem conservation areas, and wetland conservation areas were defined as protected conservation areas. Korean digital elevation model data, along with the maps of all protected areas were combined with the maps of endangered plant species, and analyzed via Geographic Information Systems (GIS). Excluding the category of "small population", endangered plant species in Korea were associated more frequently with extrinsic factors than intrinsic factors. Considering land surface only, all conservation areas in Korea totaled 4.9% of the land, far lower than International Union for Conservation of Nature and Natural Resources (IUCN)'s 10% coverage target. At the species level, 69% of the endangered plant species were detected in conservation areas, mostly in national parks. However, this result demonstrates that 31% of endangered species inhabit areas outside the conservation zones. Furthermore, at the habitat level, a large proportion of endangered species were found to reside in unprotected areas, revealing "gaps" in protected land. In the face of rapid environmental changes such as population increases, urbanization, and climate changes, converting these gap areas to endangered species' habitats, or at least including them in habitat networks, will help to perpetuate the existence of endangered species.

NVST DATA ARCHIVING SYSTEM BASED ON FASTBIT NOSQL DATABASE

  • Liu, Ying-Bo;Wang, Feng;Ji, Kai-Fan;Deng, Hui;Dai, Wei;Liang, Bo
    • Journal of The Korean Astronomical Society
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    • v.47 no.3
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    • pp.115-122
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    • 2014
  • The New Vacuum Solar Telescope (NVST) is a 1-meter vacuum solar telescope that aims to observe the fine structures of active regions on the Sun. The main tasks of the NVST are high resolution imaging and spectral observations, including the measurements of the solar magnetic field. The NVST has been collecting more than 20 million FITS files since it began routine observations in 2012 and produces maximum observational records of 120 thousand files in a day. Given the large amount of files, the effective archiving and retrieval of files becomes a critical and urgent problem. In this study, we implement a new data archiving system for the NVST based on the Fastbit Not Only Structured Query Language (NoSQL) database. Comparing to the relational database (i.e., MySQL; My Structured Query Language), the Fastbit database manifests distinctive advantages on indexing and querying performance. In a large scale database of 40 million records, the multi-field combined query response time of Fastbit database is about 15 times faster and fully meets the requirements of the NVST. Our slestudy brings a new idea for massive astronomical data archiving and would contribute to the design of data management systems for other astronomical telescopes.

A Study for the MPEG-4 Library to operate in real-time on the DSP (DSP상에서 실시간 처리 가능한 MPEG-4 Library에 관한 연구)

  • Hong, Sung-Hwa;Jung, Suk-Yong
    • Journal of the Korea Convergence Society
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    • v.2 no.1
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    • pp.7-13
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    • 2011
  • Informations of multimedia centering in the images, are combined acoustic and letter, etc. Although the network advances and the capacity of the storage media extends, these huge informations will not be able to accommodate. From meaning which is like this, International standards for the compression and a multiplexing of image, acoustic and voice H261 where admits standard, JPEG, JBIG, MPEG-l, MPEG-2, MPEG-4 and H263, G series etc, are core techniques of multimedia. At initial step of the base technique which creates the base of like this multimedia service time, we developed the real-time MPEG-4 transmission systems to provides real-time MPEG-4 multimedia services. This system means becomes the base technique which hereafter is developed and is applied various system. This system Will be able to apply from a videoconference, a building protection system and a VOD video system to use the Internet. And, They, the image sensing, embedded linux, and MPEG4 software, will become sourceful technique to develop the different system.

Hybrid Control Model of MR Damper for Seismic Response Control of Adjacent Buildings (인접건축물의 지진응답 제어를 위한 MR 감쇠기의 복합제어 모델)

  • Kim, Gee-Cheol;Kang, Joo-Won;Chae, Seoung-Hun
    • Journal of Korean Association for Spatial Structures
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    • v.11 no.2
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    • pp.101-110
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    • 2011
  • Many researchers have attempted to apply semi-active control systems in the civil engineering structures. Recently, magneto-rheological(MR) fluid dampers have been developed. This MR damper is one of semi-active dampers as a new class of smart dampers. This paper discusses the application of MR damper for seismic response control of adjacent buildings subjected to earthquake. Here, a controllable damping force of MR damper that is installed between adjacent buildings is applied to seismic response control. A hybrid model combines skyhook and groundhook control algorithm so that the benefits of each can be combined together. In this paper, hybrid control model are applied to the multi degree of freedom system representative of buildings in order to reduce seismic response of adjacent buildings. And the performance of hybrid control model is compared with that of others. It was demonstrated that hybrid control model or adjacent buildings with MR damper was effective for seismic response control of two adjacent buildings reciprocally.

Design and Implementation of a Motor Vehicle Emergency Situation Detection System Using Accelerometer (가속도센서를 이용한 차량용 사고감지시스템 설계 및 구현)

  • Kwon, Doo-Wy;Lee, Hoon-Jae;Park, Su-Hyun;Do, Kyeong-Hoon
    • Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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    • 2010.10a
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    • pp.200-202
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    • 2010
  • The number of motor vehicle registrations in Korea is increasing steadily each year, driven by industry development and economic growth. The number of traffic accidents is also rapidly increasing. Korea has a relatively high number of traffic accidents among OECD member countries, and it ranks among the highest in traffic accident death rates. This death rate is higher compared to death rates as a proportion of the number of traffic accidents in each country. It is very common for drivers to lose consciousness in traffic collisions, which leads to a failure to carry out early emergency measures. In order to prevent such situations as well as hit-and-runs and people left uncared for after traffic accidents, there is a need for motor vehicle black boxes and accident report systems. This study addressed the need for an emergency evacuation system for people injured in traffic accidents and a secondary traffic accident prevention system by developing a motor vehicle emergency situation detection and report system combined with a black box, and materializing it as an actual system.

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A Study on Building Plan for Smart Guide Services Using Augmented Reality (증강현실을 이용한 스마트 가이드 관람 서비스 구축 방안)

  • Choi, Hun;Yoon, Young-Doo;Choi, Eun-Young
    • Journal of the Korea Institute of Information and Communication Engineering
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    • v.17 no.11
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    • pp.2723-2728
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    • 2013
  • Due to the popularity of smart phones based on personal propensities and individual lifestyle changes customerized services is increasing interest in the individual. The system for personalized services make a difference in the public institutions, museum of science and history. In particular, museums and art galleries have a common motivation which is sightseeing. Museum for the history and science education a national purpose that is put, unlikely art gallery. Museum of science and History, unlike the theme parks have a combination of entertainment and education as a public institution is a large consensus. In order to achieve this objective, exhibits raise a sufficient commitment to and the exhibits should be described by age. Using augmented reality combined with effective entertainment and education measures, we propose the effective smart guide service strategies for museum.