• Title/Summary/Keyword: ATA

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Thermal Decomposition and Ablation Analysis of Solid Rocket Propulsion (삭마 및 열분해 반응을 고려한 고체 추진기관의 열해석)

  • Kim, Yun-Chul
    • Journal of the Korean Society of Propulsion Engineers
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    • v.14 no.5
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    • pp.32-44
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    • 2010
  • A two-dimensional thermal response and ablation analysis code for predicting charring material ablation and shape change on solid rocket nozzle is presented. The thermogravimetric analysis (TGA) techniques have been used to characterize the thermal decomposition constants for Arrhenius parameters. Two heterogeneous reactions involving carbon and the oxidizing species of $H_2O$ and $CO_2$ are considered and determined by Zvyagin's ablation model and kinetic constants. The moving boundary problem and mesh moving are solved by remeshing-rezoning method in MSC-Marc-ATAS program. The difference between the calculated and experimental value of char and ablation thickness is up to 20%. For the performance prediction of thermal protection systems, this method will be integrated with a three-dimensional finite-element thermal and structure analysis code through the real time sensing of in-depth temperature and heat flux.

Levels of Depression and Anxiety Post-Mastectomy in Breast Cancer Patients at a Public Sector Hospital in Karachi

  • Khan, Sara;Khan, Naveed Ali;Rehman, Ata Ur;Khan, Iqra;Samo, Khursheed A;Memon, Amjad Siraj
    • Asian Pacific Journal of Cancer Prevention
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    • v.17 no.3
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    • pp.1337-1340
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    • 2016
  • Background: There is a noticeable change in the approach with which women nowadays seek help for diseases like breast cancer, primarily due to awareness campaigns, but what happens after surgical procedures is of great significance too. This study focused on the several psychological connotations attached to mastectomy and how the patients cope. Objective: To understand the pattern of anxiety and level of depression among Pakistani patients undergoing mastectomy. Materials and Methods: The sample size consisted of 88 patients who had undergone mastectomy at the different surgical units of the Civil Hospital, Karachi, from January 2012-December 2014; The questionnaire was administered before they were discharged i.e. within 3 days of surgical procedures. The patients were asked if they were willing to participate in this study, those who agreed signed the consent form and then we preceded by asking questions with a standardized tool. A self made questionnaire was constructed keeping in mind the nature and specification of the disease, which consisted of 20 questions related to anxiety and depression, focusing on a mixture of psychological and physiological symptoms. Results: There were a total of 88 patients out of which 36 (41%) were aged 51 to 60 years, 24 (27.2%) of the patients were in the age category of 41 to 50 years, 17 aged 61 and above (19.3%) and only 11 (12.5%) 30-40 years of age, the youngest of all the age categories. The pattern of depression and anxiety was found to be similar among all age categories, severe depression and anxiety predominating over moderate level of such symptoms, with only relatively few patients sufering mild or no depression symptoms. Conclusions: It was concluded that going through mastectomy leads to moderate to severe levels of depression and anxiety, primarily because the females feel incomplete and insecure after losing a part of themselves.

Rapid Identification of Ginseng Cultivars (Panax ginseng Meyer) Using Novel SNP-Based Probes

  • Jo, Ick-Hyun;Bang, Kyong-Hwan;Kim, Young-Chang;Lee, Jei-Wan;Seo, A-Yeon;Seong, Bong-Jae;Kim, Hyun-Ho;Kim, Dong-Hwi;Cha, Seon-Woo;Cho, Yong-Gu;Kim, Hong-Sig
    • Journal of Ginseng Research
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    • v.35 no.4
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    • pp.504-513
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    • 2011
  • In order to develop a novel system for the discrimination of five ginseng cultivars (Panax ginseng Meyer), single nucleotide polymorphism (SNP) genotyping assays with real-time polymerase chain reaction were conducted. Nucleotide substitution in gDNA library clones of P. ginseng cv. Yunpoong was targeted for the SNP genotyping assay. From these SNP sites, a set of modified SNP specific fluorescence probes (PGP74, PGP110, and PGP130) and novel primer sets have been developed to distinguish among five ginseng cultivars. The combination of the SNP type of the five cultivars, Chungpoong, Yunpoong, Gopoong, Kumpoong, and Sunpoong, was identified as 'ATA', 'GCC', 'GTA', 'GCA', and 'ACC', respectively. This study represents the first report of the identification of ginseng cultivars by fluorescence probes. An SNP genotyping assay using fluorescence probes could prove useful for the identification of ginseng cultivars and ginseng seed management systems and guarantee the purity of ginseng seed.

LARGE STORAGE SYSTEM FOR HIGH-SPEED RECORDING OF OBSERVED DATA (관측 데이터의 고속기록을 위한 대용량 저장시스템)

  • OH SE-JIN;ROH DUK-GYOO;KIM KWANG-DONG;SONG MIN-GYU;JE DO-HEUNG;WI SEOG-OH;KIM TAE-SUNG;WHITNEY ALAN R.
    • Publications of The Korean Astronomical Society
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    • v.19 no.1
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    • pp.83-92
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    • 2004
  • In this paper, we introduce the development of the large storage system in order to record the observed space radio signal in the Korean VLBI Network(KVN) with high-speed. The KVN is the Very Long Baseline Interferometery(VLBI) to observe the birth of star, the structure of space by constructing radio telescope with diameter 21m at the Seoul, Ulsan, Jeju from 2001 to 2007 years. To do this, Korea Astronomy Observatory joined the international consortium for developing the high-speed large storage system(Mark 5), which is developed by MIT Haystack observatory. The Mark 5 system based on hard disk has to record up to 1 Gbps the observed space radio signal. The main features of Mark 5 system are as follows; First it is able to directly record the input data to the hard disk without PC1(Peripheral Component Interconnect) internal bus, and the second, it has two hard disk banks, which are able to hot-swap ATA/IDE type very cheap up to 1 Gbps recording and playback. The third is that it follows the international VLBI standard interface hardware(VSI-H). Therefore it can be connect directly the VSI-H type system at the input/output. Finally it also supports e- VLBI(Electronic-VLBI) through the standard Gigabits Ethernet connection.

Bearing capacity of footing supported by geogrid encased stone columns on soft soil

  • Demir, Ahmet;Sarici, Talha
    • Geomechanics and Engineering
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    • v.12 no.3
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    • pp.417-439
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    • 2017
  • The stone columns are increasingly being used as a soil improvement method for supporting a wide variety of structures (such as road embankment, buildings, storage tanks etc.) especially built on soft soil. Soil improvement by the stone column method overcomes the settlement problem and low stability. Nevertheless, stone column in very soft soils may not be functional due to insufficient lateral confinement. The required lateral confinement can be overcome by encasing the stone column with a suitable geosynthetic. Encasement of stone columns with geogrid is one of the ideal forms of improving the performance of stone columns. This paper presents the results of a series of experimental tests and numerical analysis to investigate the behavior of stone columns with and without geogrid encasement in soft clay deposits. A total of six small scale laboratory tests were carried out using circular footing with diameters of 0.05 m and 0.1 m. In addition, a well-known available software program called PLAXIS was used to numerical analysis, which was validated by the experimental tests. After good validation, detailed of parametric studies were performed. Different parameters such as bearing capacity of stone columns with and without geogrid encasement, stiffness of geogrid encasement, depth of encasement from ground level, diameter of stone columns, internal friction angle of crushed stone and lateral bulging of stone columns were analyzed. As a result of this study, stone column method can be used in the improvement of soft ground and clear development in the bearing capacity of the stone column occurs due to geogrid encasement. Moreover, the bearing capacity is effected from the diameter of the stone column, the angle of internal friction, rigidity of the encasement, and depth of encasement. Lateral bulging is minimized by geogrid encasement and effected from geogrid rigidity, depth of encasement and diameter of the stone column.

A Closed Counter-Current Two-Phase Thermosyphon Loop of a Cold Neutron Source in HANARO Research Reactor (하나로 원자로에 설치될 대향 이상 열사이펀 루프에 관한 실험)

  • Hwang, Kwon-Sang;Cho, Man-Soon;Sung, Hyung-Jin
    • Transactions of the Korean Society of Mechanical Engineers B
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    • v.24 no.8
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    • pp.1038-1045
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    • 2000
  • An experimental study was carried out to delineate the flow characteristics in a closed countescurrent two-phase thermo syphon with concentric tubes. This is to be installed in the HANARO research reactor as a part of a Cold Neutron Source(CNS). In the present investigation, experiments ata room temperature with Freon-II3 as a moderator were performed. Results show that, based on the magnitude of pressure fluctuation, the flow regimes could be divided into 4 distinct ones in the ($V_f,\;Q_i$) plane, where $V_f$ represents the volume of the charged liquid and $Q_i$ the heat load: a stable flow regime, an oscillatory flow regime, a restablized flow regime and a dryout flow regime. For $V_f$>2.5l, the flow is stable at low $Q_i$. However, as $Q_i$ increases, the flow becomes oscillatory and finally restablizes As $V_f$ increases, the oscillation amplitude decreases, reaching to the restablized flow region at low $Q_i$, and the liquid level in the moderator cell remains high. In the oscillatory flow regimes, for a fixed VI; the oscillating period of time varies with $Q_i$, having a minimum value at a certain value of $Q_i$. The heat load, where the oscillating period of time is minimum, decreases as $V_f$ increases.

Development of a Spatio-Temporal DSMS for the Real-time Management of Moving Objects Data Stream (이동체 데이터 스트림의 실시간 관리를 위한 시공간 DSMS의 개발)

  • Shin, In-Su;Kim, Jang-Woo;Kim, Joung-Joon;Han, Ki-Joon
    • Journal of Korean Society for Geospatial Information Science
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    • v.20 no.1
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    • pp.21-31
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    • 2012
  • Recently, according to the development of ubiquitous computing technology, the efficient management of locations of moving objects is increasing rapidly in various fields. However, MODBMS and DSMS can not support the efficient real-time management of spatio-temporal stream data of moving objects. Therefore, this paper designed and implemented a spatio-temporal DSMS which can support the efficient real-time management of spatio-temporal stream data of moving objects. Especially, to develop the spatio-temporal DSMS, we extended STREAM of Stanford University and used GEOS that supports spatial data types and spatial operators of OGC. Finally, this paper proved the efficiency of the spatio-temporal DSMS by applying it to the real-time monitoring field which requires the real-time management of spatio-temporal stream data of moving objects.

Formative Characteristics Regarding Traditional Cultural Identity and Development of Fashion Culture Products - Past, Present, and Future - (전통문화 정체성에 관한 조형성 특성과 패션문화상품 개발연구 - Past, Present & Future -)

  • Jon, Ji-Hyon;Raftery, Andrew
    • Journal of the Korean Society of Costume
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    • v.59 no.7
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    • pp.65-76
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    • 2009
  • Korea has established a code for the economic and cultural industry that covers a wide range of classes unlike the old information era which was limited to the simple knowledge, technology, tools, morals, and customers that had been established in our society. On the other hand, 'culture marketing' is a series of marketing activities in which value-added items are created and shared. The combination of business management and culture seemed pretty awkward considering how rapidly the world was changing, however, the nature of today's culture has changed and the economic nature of culture products has resulted from those changes. In this paper, two authors who expressed the cultural identity in the culture products are studied through a comparison analysis; the author Min Yeongsoon expressed the identity confusion that she experienced in a foreign country and how she overcame homesickness in her work; and the author Kim Ata expressed his confidence in Asia and used his clear and loud voice to express the culture in his work. In addition, today's culture products are affected by the surrounding cultures such as the member's traditional society, environmental culture, and individual's culture. It is a good source for good works of art. In this study, the efforts of seeking the cultural identity, structuring the concept, seeking a new market and possibilities are used to make a consistent process in order to make a series of the systems required for planning and developing culture products.

The Early Chemical Enrichment Histories of Two Sculptor Group Dwarf Galaxies as Revealed by RR Lyrae Variables

  • Yang, Soung-Chul;Wagner-Kaiser, Rachel;Sarajedini, Ata;Kim, Sang Chul;Kyeong, Jaemann
    • The Bulletin of The Korean Astronomical Society
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    • v.39 no.1
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    • pp.39.1-39.1
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    • 2014
  • We present the results of our analysis of the RR Lyrae (RRL) variable stars detected in two transition-type dwarf galaxies (dTrans), ESO294-G010 and ESO410-G005 in the Sculptor group, which is known to be one of the closest neighboring galaxy groups to our Local Group. Using deep archival images from the Advanced Camera for Surveys (ACS) onboard the Hubble Space Telescope (HST), we have identified a sample of RR Lyrae candidates in both dTrans galaxies [219 RRab (RR0) and 13 RRc (RR1) variables in ESO294-G010; 225 RRab and 44 RRc stars in ESO410-G005]. The metallicities of the individual RRab stars are calculated via the period-amplitude-[Fe/H] relation derived by Alcock et al. This yields mean metallicities of <[Fe/H]>_{ESO294} = -1.77 +/- 0.03 and <[Fe/H]>_{ESO410} = -1.64+/- 0.03. The RRL metallicity distribution functions (MDFs) are investigated further via simple chemical evolution models; these reveal the relics of the early chemical enrichment processes for these two dTrans galaxies. In the case of both galaxies, the shapes of the RRL MDFs are well-described by pre-enrichment models. This suggests two possible channels for the early chemical evolution for these Sculptor group dTrans galaxies: 1) The ancient stellar populations of our target dwarf galaxies might have formed from the star forming gas which was already enriched through "prompt initial enrichment" or an "initial nucleosynthetic spike" from the very first massive stars, or 2) this pre-enrichment state might have been achieved by the end products from more evolved systems of their nearest neighbor, NGC 55.

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Development of Black Color Spinel Pigment for High Temperature (고온용 검정색 스피넬 안료의 개발)

  • Lee, Kwang-Ho;Myung, Min-Soo;Lee, Byung-Ha
    • Journal of the Korean Ceramic Society
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    • v.44 no.5 s.300
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    • pp.160-165
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    • 2007
  • This research studied the most suitable synthesis condition of mineral pigments of black spinel, which have a stable chromogenic characteristic also ata high temperature of $1400^{\circ}C$ (it is not currently producedin the country) to meet not only functionality of ceramics but also an individual's aesthetic. It was synthesized by the plastic synthetic method on the basis of basic formation of $Fe_2O_3,\;Cr_2O_3$, Quartz, Kaolin, CoO, $MnO_2$, and plasticity was made at $1500^{\circ}C,\;1550^{\circ}C,\;1600^{\circ}C,\;1650^{\circ}C$. We researched the most suitable condition of plasticity and composition which make crystallization of spinel system and chromogenic characteristic close to black in every composition. And for the experiment of application to Zirconia, after adding synthesized pigments to Zirconia and plasticizing them, we analyzed their color and property of matters. The most suitable synthesis conditions of mineral pigments of black spinel system require composition of $Fe_2O_3-32.01%,\;Cr_2O_3-30.47%$, Quartz-9.66%, Kaolin-18.53%, CoO-3.71%, $MnO_2-5.62%$ and condition of plasticity kept for 1 h at $1600^{\circ}C$. When we added pigments synthesized in this way to Zirconia with 5 wt% and plasticized them at $1410^{\circ}C$, the result was that the degree of $strength-32.6kgf/mm^2$, absorptance-0.108%, $luminosity-L^*:37.54,\;color-a^*:1.31,\;b^*:2.61$ and their use suited for artificial jewelry or decoration Zirconia goods.