• Title/Summary/Keyword: K5 system

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Classification of Synoptic Meteorological Conditions for the Medium or Long Term Atmospheric Environmental Assessment in Urban Scale (도시규모 중·장기 대기질영향평가를 위한 종관기상조건의 분류)

  • Kim, Cheol-Hee;Son, Hye-Young;Kim, Ji-A
    • Journal of Environmental Impact Assessment
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    • v.16 no.2
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    • pp.157-168
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    • 2007
  • In case there is a need to run the multi-year urban scale air qulaity model, it is a difficult task due to the computational demand, requiring the statistical approach for the long time atmospheric environmental assessment. In an effort to approach toward long term urban assessment, the sixteen synoptic meteorological conditions are statistically classified from the estimated geostrophic wind speeds and directions of 850 hPa geopotential height field during 2000 ~ 2005. The geostrophic wind directions are subdivided into four even intervals (north, east, south, and west), geostrophic wind speeds into two classes(${\leq}5m/s$ and >5m/s), and daily mean cloud amount into 2 classes(${\leq}5/10$ and >5/10), which result into sixteen classes of the synoptic meteorological cases for each season. The frequency distributions for each 16 synoptic meteorological case are examined and some discussions on how these synoptic classifications can be used in the environmental assessment are presented.

A Study on the Performance of Fayoumi, Rhode Island Red and Fayoumi × Rhode Island Red Chickens under Rural Condition of Bangladesh

  • Barua, A.;Howlider, M.A.R.;Yoshimura, Y.
    • Asian-Australasian Journal of Animal Sciences
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    • v.11 no.6
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    • pp.635-641
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    • 1998
  • Two months old Fayoumi, Rhode Island Red, and Fayoumi ${\times}$ Rhode Island Red chickens were reared upto 512 days of their age in the villages surrounding Bangladesh Agricultural University in order to study comparative performances of the 3 genetic groups with or without extra feeding to scavenging system of rearing and also, to study the suitability of these breeds reared under the rural condition. Fayoumi attained earlier sexual maturity (238.5 vs 262.5 d) and laid more eggs than other breeds/types. Rhode Island Red produced the largest eggs, but mortality rates were highest and Fayoumi showed greatest resistance to diseases. Crossbred was heaviest (1,275 g at 247.5 d of age) and had highest hatchability than parental breeds. Age at sexual maturity (247.5 d), 50% egg production, peak production and mortality in crossbreds were mostly influenced by sire Fayoumi but for the egg weight and body weight, the effect of the dam Rhode Island Red was significant. Extra feeding was found more beneficial to the chickens irrespective of breeds and types. The crossbred Fo ${\times}$ RIR chickens were found more suitable under rural scavenging system than the exotic breeds, Fayoumi and Rhode Island Red in the rural areas of Bangladesh.

A study on the development of MVR desalination plant and its performance analysis (MVR해수담수화플랜트의 개발 및 성능에 관한 연구)

  • Kim, Yeongmin;Chun, Wongee;Kim, Dongkook
    • Journal of Energy Engineering
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    • v.25 no.3
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    • pp.59-65
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    • 2016
  • MVR evaporation is a method of pressurizing the evaporating steam to raise its temperature with an electric compressor instead of burning fuel and reusing the heat source through the embraced heat exchanger to minimize energy use. MVR desalination system with wind power uses varying wind power instead of stable electricity and can flexibly control the volume of fresh water production. The present study introduces the design, construction and operation of a MVR desalination system of 30ton/day capacity. Experimental results, MVR compression ratio is higher than 1.5, temperature difference of the main heat exchanger is $5{\sim}7^{\circ}C$. This value shows the same performance as the designed value.

Implementation of A Dielectric-Resonator Oscillator for the Microwave Radar Sensor Applications (마이크로파 레이더 센서 응용을 위한 발진기 설계 및 제작)

  • Kim, Kang-Wook
    • Journal of Sensor Science and Technology
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    • v.12 no.4
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    • pp.185-190
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    • 2003
  • Recently, sensors which use the infrared light, supersonic waves, and electromagnetic waves have been used for many applications to detect information of the object. For these sensors, the accompanying system which utilizes the sensor should be systematically developed. In this paper, a general microwave radar sensor system is briefly described, and then basic applications of a CW doppler radar sensor system are introduced. For the CW doppler radar sensor applications, a highly-stable, low-cost Dielectric Resonator Oscillator (DRO) has also been designed and implemented, which can be used for commercial microwave sensor systems. The implemented DRO has output power of +5.33 dBm at 12.67 GHz and phase noise of -108.5 dBc/Hz at the 100 kHz offset frequency.

RESEARCH PAPERS : THE KINETICS ON THE BIOLOGICAL REACTION IN MEMBRANE BIOREACTOR (MBR) WITH GRAVITATIONAL AND TRANSVERSAL FILTRATION

  • Jang, Nam-J.;Hwang, Moon-H.;Yeo, Young-H.;Shim, Wang-G.;S. Vigneswaran;Kim, In-S.
    • Environmental Engineering Research
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    • v.9 no.5
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    • pp.238-247
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    • 2004
  • The objective of this study was to develop kinetic model for the MBR and investigate kinetic characteristics of the gravitational flow transverse direction MBR system. Kinetic model was derived by mass balance of substratc and biomass combined with empirical membranc filtration rerm for the MBR. To find kinctic values, permeale flux and COD removal were analyzed through the laboratory, MBR operation as different solids retention times. Permeate flux was ranged 2.5-5.0 LMH (L/m$^2$/hr) as sludge characteristics in each run. Although the soluble COD in the bioreactor was changed, the effluent COD was stable as average 99% removal rate during the experimental periods. Y$_g$ of this MBR system was higher than those of cross-flow MBR processes. The kinetics of this MBR showed that smaller k, larger b, and larger K$_s$ values than the conventional activated sludge process. These results indicated that substrate was used for cell maintenance rather than growth in this MBR system.

PFM-Mode Boost DC-DC Convertor for Mobile Multimedia Application (휴대용 멀티기기를 위한 PFM방식의 승압형 DC-DC 변환기)

  • Kim, Ji-Man;Park, Yong-Su;Song, Han-Jung
    • 전자공학회논문지 IE
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    • v.47 no.3
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    • pp.14-18
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    • 2010
  • In this paper, we describe a CMOS DC-DC converter with a variable output voltage(5-7V @100mA) for a portable battery-operated system applications. The proposed DC-DC converter is used along with a Pulse-Frequency Modulation (PFM) method and consists of reference circuit, a feedback resistor, a controller, and an internal oscillator. The integrated DC-DC converter with two external passive components(L,C) has been designed and fabricated on a 0.5um 2-poly 3-metal CMOS process and could be applied to the Personal Digital Assistants(PDA), cellular Phone, Laptop Computer, etc.

Fabrication of an On System based on an Optical Delay line with Cylindrical PZT (실린더형 압전소자 광지연선을 이용한 광 간섭형 단층촬영(OCT) 시스템 제작)

  • Park, Sung-Jin;Kim, Young-Kwan;Kim, Yong-Pyung
    • Korean Journal of Optics and Photonics
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    • v.17 no.2
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    • pp.159-164
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    • 2006
  • We demonstrate a compact optical coherence tomography(OCT) system based on the optical fiber delay line controlled by a cylindrical piezo-electric transducer(PZT). An 18-m length of single mode fiber is wrapped under constant tension around a PZT. Approximately 134 windings are used. Wraps of the long length of fiber allow the small expansion of the PZT to be magnified to an optical path length delay of 0.78 m. The OCT system shows characteristics for 2-dimensional imaging, exhibiting 96.9dB of signal-to-noise ratio(SNR), $18.6{\pm}0.5\;{\mu}m$ of axial resolution, and $5\;{\mu}m$ of lateral resolution with samples.

An Extended L-band Erbium-doped Fiber Amplifier to Amplify 1625 nm OTDR Signal for a Long Distance Monitoring System (장거리 광선로 감시용 1625 nm OTDR 신호 증폭을 위한 효율적인 Extended L-band Erbium-doped Fiber Amplifier)

  • Lee, Han-Hyub;Seo, Dae-Dong;Lee, Dong-Han;Choi, Hyun-Beom;Jeon, Jeon-Gu
    • Korean Journal of Optics and Photonics
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    • v.16 no.5
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    • pp.411-416
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    • 2005
  • We have designed an extended L-band Erbium-doped fiber amplifier to amplify 1625 nm optical time domain reflectometry signal for a long distance monitoring system. The proposed amplifier has a dual-stage structure without an isolator. Gain improvement of 5.1 dB has been achieved by adding a fiber Bragg grating and a narrow band pass filter. As a result, the 16.3 dB gain and 7.1 dB noise figure has been successfully accomplished.

Effect of CQ-amine ratio on the degree of conversion in resin monomers with binary and ternary photoinitiation systems

  • Moon, Ho-Jin;Shin, Dong-Hoon
    • Restorative Dentistry and Endodontics
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    • v.37 no.2
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    • pp.96-103
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    • 2012
  • Objectives: This study evaluated the effect of camphorquinone (CQ)-amine ratio on the C=C double bond conversion of resins with binary and ternary photoinitiation systems. Materials and Methods: Two monomer mixtures (37.5 Bis-GMA/37.5 Bis- EMA/25 TEGDMA) with binary systems (CQ/DMAEMA in weight ratio, group A [0.5/1.0] and B [1.0/0.5]) and four mixtures with ternary system (CQ/OPPI/DMAEMA, group C [0.1/1.0/0.1], D [0.1/1.0/ 0.2], E [0.2/1.0/0.1] and F [0.2/1.0/0.2]) were tested: 1 : 2 or 2 : 1 CQ-amine ratio in binary system, while 1 : 1 ratio was added in ternary system. The monomer mixture was cured for 5, 20, 40, and 300 sec with a Demetron 400 curing unit (Demetron). After each exposure time, degree of conversion (DC) was estimated using Fourier transform infrared (FTIR) spectrophotometer (Nicolet 520, Nicolet Instrument Corp.). The results were analyzed by ANOVA followed by Scheffe test, with p = 0.05 as the level of significance. Results: DC (%) was expressed in the order of curing time (5, 20, 40, and 300 sec). Group A ($14.63{\pm}10.42$, $25.23{\pm}6.32$, $51.62{\pm}2.69$, $68.52{\pm}2.77$); Group B ($4.04{\pm}6.23$, $16.56{\pm}3.38$, $37.95{\pm}2.79$, $64.48{\pm}1.21$); Group C ($16.87{\pm}5.72$, $55.47{\pm}2.75$, $60.83{\pm}2.07$, $68.32{\pm}3.31$); Group D ($23.77{\pm}1.64$, $61.05{\pm}1.82$, $65.13{\pm}2.09$, $71.87{\pm}1.17$); Group E ($28.66{\pm}2.92$, $56.68{\pm}1.33$, $60.66{\pm}1.17$, $68.78{\pm}1.30$); Group F ($39.74{\pm}6.31$, $61.07{\pm}2.58$, $64.22{\pm}2.29$, $69.94{\pm}2.15$). Conclusion: All the monomers with ternary photoinitiation system showed higher DC than the ones with binary system, until 40 sec. Concerning about the effect of CQ-amine ratio on the DC, group A converted into polymer more than group B in binary system. However, there was no significant difference among groups with ternary system, except group C when cured for 5 sec only.

RELAP5/MOD3 Assessment Against a ROSA-IV/LSTF Loss-of-RHRS Experiment

  • Park, Chul-Jin;Han, Kee-Soo;Lee, Cheol-Sin;Kim, Hee-Cheol;Lee, Sang-Keun
    • Proceedings of the Korean Nuclear Society Conference
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    • 1996.05b
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    • pp.745-750
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    • 1996
  • An analysis of a loss of residual heat removal system (RHRS) event during midloop operation after reactor shutdown was performed using the RELAP5/MOD3 thermal-hydraulic computer code. The experimental data of a 5% cold leg break test conducted at the ROSA-IV Large Scale Test Facility (LSTF) to simulate a main coolant pump shaft seal removal event during midloop operation of a Westinghouse-type PWR were used in the analysis. The predicted core boiling time and the peak primary system pressure showed good agreements with the measured data. Some differences between the calculational results and the experimental results were, however, found in areas of the timing of loop seal clearing and the temperature distribution in a pressurizer. Other calculational problems identified were discussed as well.

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