• Proceedings of the Korean Society of Propulsion Engineers Conference
• /
• 2004.10a
• /
• pp.274-277
• /
• 2004

Fuel/air mixing in air turbo ramjet(ATR) combustor is a significant parameter of combustion stability and efficiency. In this study, fuel distribution in the ATR model combustor was measured to compare the degree of mixing with respect to the velocity ratio$(r=v_a/v_f)$ between fuel gas and air. Planar laser-induced fluorescence(PLIF) and image processing method were used to obtain two dimensional fuel distribution. Fuel mixing went bad with approaching to r=1.

• Korean Journal of Ecology and Environment
• /
• v.38 no.3 s.113
• /
• pp.313-321
• /
• 2005

Based on the result that biological control agent (BCA) increased the dissolved microcystin-LR in a field experiment to control the cyanobacterial bloom (Kim etal., 2005), a laboratory experiment was used to evaluate the effects of dissolved microcystin-LR (MCLR) with different concentrations on abundance, dominance, diversity of phytoplankton community, concentration of chlorophyll a and microcystin concentration in replicated microcosms. The treatments in this laboratory experiment comprised different concentrations of T1 (natural MCLR concentration), T10 (ten times to natural MCLR concentration), and T100 (one hundred times to natural MCLR concentration). MCLR treatment of exclusively Stephanodiscus hantzschii-dominated community in Chonho bridge hardly changed in algal species, but abundance. In Kildong pond, Aulacoseira and Dinobryonrich community was replaced by green algae Scenedesmus-rich community especially in T100 experiment. However, in Yangsoori-Ryukgakji Pond having the highest concentration of initial MCLR, Microcystis aeruginosa was decreased in abundance. Therefore, the treatment of BCA to control M. aeruginosa severely changed the Phytoplankton community in term of algal species, abundance (chlorophyll a) and dissolved microcystin-LR via a high release of MCLR.

• Journal of Bio-Environment Control
• /
• v.21 no.4
• /
• pp.419-427
• /
• 2012

This study was carried out to investigate the effect of two shading methods, shading agent spray on the glasshouse and internal shading screen treatment, on the growth and fruit quality of paprika (Capsicum annuum L. 'Cupra' and 'Coletti') in summer season cultivation. In the shading agent treatment, a commercial shading agent diluted with water at a ratio of 1 : 4 was sprayed on the roof of a glasshouse. In the internal shading screen treatment, a 10~20% shaded screen was used during the day time when the sun radiation was greater than $700W{\cdot}m^{-2}$. Compared to the unshaded control, photosynthetic photon flux density (PPFD) decreased in the greenhouse in the shading agent (SA) and shading screen (SS) treatments by 20% and 30%, respectively. Lower air temperatures and higher relative humidities were observed in the SA than in both the control and the SS treatment. Time to reach the break point of humidity deficit $8g{\cdot}m^{-3}$ was 2 hours late in the SA than in both the control and the SS treatment. Compared to control, both the SA and the SS treatments showed lower instantaneous temperatures of leaf, fruit, and flower by $2^{\circ}C$, $5^{\circ}C$ and $3^{\circ}C$, respectively. There were no differences in number of branches, stem diameter, and leaf size among treatments although both shading treatments promoted plant height in both cultivars. Botrytis infection ratio declined with the SA treatment by 14.7% in 'Cupra' and 22.1% in 'Coletti' as compared to that in the control. Shading increased fruit size in both cultivars, whereas no differences were observed in the number of locules and thickness of fruit tissue among treatments. Shading treatment increased mean fruit weight by a range of 10 to 15 g per fruit, while it decreased soluble solids contents as compared to that in the control. Similar Hunter values were observed among treatments, while fruit firmness increased slightly in shading treatments. Compared to the control, shading treatments improved marketable fruits by 11.7~22.6% and increased the number of fruits per plant by 4~9.2 in both 'Cupra' and 'Coletti'. The results of this study indicate that shading agent application on the roof of glasshouse would be one of the most effective options to reduce heat stress imposed on the paprika crop in summer cultivation, resulting in improved crop growth and fruit yield.

• The KIPS Transactions:PartC
• /
• v.11C no.4
• /
• pp.545-554
• /
• 2004

WebDAV is a protocol to support collaboration among the workers in geographically distant locations through the Internet. WebDAV extends the web communication protocol HTTP/1.1 to provide a standard infrastructure for supporting asynchronous collaboration for various contents across the Internet. To provide the WebDAV functionality in legacy applications such as web-based collaborative systems or document management systems, those systems need to be implemented additionally to handle the WebDAV methods and headers information. In this paper, we developed an Apache-based WebDAV server, named DAVinci(WebDAV Is New Collaborative web-authoring Innovation)which supports the WebDAV specification. DAVinci was implemented as a form of service provider on a mod_dav Apache module. Mod_day, which is an Apache module, is an open source module to provide WebDAV capabilities in an Apache web server. We used a file system for storing resources and the PostgreSQL database for their properties. In addition, the system provides a consistency manager to guarantee that both resources and properties are maintained without inconsistency between resources and their properties.

• The Transactions of the Korea Information Processing Society
• /
• v.4 no.4
• /
• pp.1106-1120
• /
• 1997

In this paper,we prosent a new run-time support system for SR usitn POSIX threads (Pthreads),called SR/RTS +.SR supports a rich set of concurent programming techniques with multiple cincurrency control primit-ives Since the original RTS for SR uses its own thread management facility,it should be modifide to work on different computer systems.Furthermore,the run-time efficiency of the RTS should be considered in association with those different sytems.Thus,to portability and to guarantee the predictable run-time ef-ficiency,SR/RTS + is designed on the pthreads(POSIX Threads )which supports multiple threads of con-trol within a single POSIX process.Also, the SR compiler is modified to generate the codes appropriate for pthreads interface.SR/RTS + has been develped on Spare Workstation using pthreads library announced by Florida State University and tested with the SR verification suite distribute by the University of Arizona.

• Polymer(Korea)
• /
• v.33 no.5
• /
• pp.452-457
• /
• 2009

Hybrid nanomaterials consisting of multi-walled carbon nanotube(MWNT) and/or PEDOT of conductive polymer were prepared in this study. In the presence of catalyst and ligand, the MWNT-Br compound prepared by the successive surface treatment reaction was mixed with MMA to initiate the atom transfer radical polymerization process. PMMA was covalently linked to the surface of MWNT for the formation of MWNT/PMMA nanocomposites. The EDOT and oxidant were added in the aqueous emulsion of PS produced via a miniemulsion polymerization process and then it proceeded to carry out the oxidative chemical polymerization of EDOT for the preparation of PEDOT/PS nanoparticles with the core-shell structure. The aqueous dispersion of PEDOT:poly(styrene sulfonate) (PSS) was mixed with the silica particles treated with a silane compound and thus PEDOT:PSS-clad silica nanoparticles were prepared by the surface chemistry reaction. The hybrid nanomaterials were analyzed by using TEM, FE-SEM, TGA, EDX, UV, and FT-IR.

• The KIPS Transactions:PartC
• /
• v.11C no.5
• /
• pp.703-710
• /
• 2004

WebDAV is a protocol to support collaboration among one or more groups in geographically distant locations through the internet. WebDAV extends the web communication protocol HTTP/1.1 to provide a standard infrastructure for .supporting asynchronous collaboration for various contents across the internet. A WebDAV client uses HTTP requests to perform a renewal and update action to the resources in WebDAY servers. So, it is desirable that the client supports the ability of authoring and version management with a good concurrency control and property management. In this paper, to enhance usability, we developed a .NET-based WebDAV client with a user interface similar to the Windows Explorer. The developed WebDAV client supports easy launching of the authoring application and appropriate lock control for the server resources. In addition, through the functionality of process monitoring, it supports automatic update of the server resources when the modification of the resources are completed by the user. The WebDAY client is a .NET-based application written in the C＃ language, running on any platform supporting a .NET framework.

• Journal of IKEEE
• /
• v.14 no.1
• /
• pp.8-16
• /
• 2010

This paper presents a design of the successive approximation ADC(SA-ADC) applicable to a midium-low speed analog-front end(AFE) for the maximum 15MS/s CCD image processing. SA-ADC is effective in applications ranging widely between low and mid data rates due to the large power scaling effect on the operating frequency variations in some other way of pipelined ADCs. The proposed design exhibits some distinctive features. The "differential capacitor-coupling scheme" segregates the input sampling behavior from the sub-DAC incorporating the differential input and the sub-DAC output, which prominently reduces the loading throughout the signal path. Determining the MSB(sign bit) from the held input data in advance of the data conversion period, a kind of the signed successive approximation, leads to the reduction of the sub-DAC hardware overhead by 1 bit and the conversion period by 1 cycle. Characterizing the proposed design in a 3.3 V $0.35-{\mu}m$ CMOS process by Spectre simulations verified its validity of the application to CCD analog front-ends.

• The Korean Journal of Petroleum Geology
• /
• v.1 no.1 s.1
• /
• pp.29-35
• /
• 1993

Seismic reflection data can be used to extract information about the velocity structure of the earth. This process is called a velocity inversion of the seismic data. However, it is difficult to recover a broad band reflection coefficient series because the frequency band of seismic trace is limited. The linear programming method has been examined to find the simplest velocity model that has frequency components consistent with the usable frequencies of the seismic trace and interval velocity data. The velocity structure of the earth is displayed in pseudovelocity section. After the linear program had been tested with a synthetic seismic trace, it was applied to the seismic reflection data of the Block Ⅱ in the Yellow Sea. By comparing the pseudovelocity section with sonic logs obtained from the well in the same area, it was possible to define the lithostratigraphy and the boundaries of Cretaceous volcanics and Cretaceous metavolcanics.

• Journal of Korean Society of Forest Science
• /
• v.96 no.4
• /
• pp.470-476
• /
• 2007

This study is conducted to identify responses of plants to low $O_3$ concentration, Five species, Liriodendron tulipifera, Cornus officinalis, Ginkgoba biloba, Zelkova serrata, and Acer palmatum, were exposed to low ozone concentration from June 9 to July 8 in the phytotron, We measured chlorophyll contents, leaf diffusion resistance, leaf transpiration, and antioxidant enzyme activities; ascorbate peroxidase(APX), Especially, Liriodendron tulipifera and Cornus officinalis showed sensitive responses to ozone treatment as visible injuries, while other four species relatively showed tolerant responses. However, we noticed that almost all species under ozone treatment were lower physiological activities such as chlorophyll contents, leaf diffusion resistance, leaf transpiration, and antioxidant enzyme activities with time even without any visible injury.