• Title/Summary/Keyword: Chang-Ki(張機)

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The Radiation Characteristics Improvement and Thickness Reduction of Base Station Antenna with Artificial Magnetic Conductor (인공 자기 도체를 이용한 기지국 안테나의 방사 특성 개선 및 두께 감소)

  • Son, Cheol-Hong;Ahn, Ji-Hwan;Chang, Ki-Hun;Yoon, Ji-Hwan;Yoon, Young-Joong
    • The Journal of Korean Institute of Electromagnetic Engineering and Science
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    • v.20 no.12
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    • pp.1233-1242
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    • 2009
  • In this paper, a Base Station Antenna(BSA) utilizing Artificial Magnetic Conductor(AMC) as reflector instead of common conductive plate to improve radiation characteristics and achieve low-profile is proposed. In the case of the conventional BSA on conductive surface which acts as a reflector, a secondary radiation is caused at the corner of the conductive surface, and it increases the back-lobe of the antenna, resulting in deteriorating the radiation characteristic of the conventional BSA. However, using the AMC, the back-lobe of the BSA can be largely reduced by the surface wave suppression. And the Side-Lobe Level(SLL) is also improved, resulting in preventing the service area overlapped. Furthermore, due to the $0^{\circ}$ reflection phase on AMC, the profile of the BSA can be also reduced.

Changes in concentration of tocopherols and fatty acids during germination and maturation of soybean(Glycine max) (대두의 발아 및 성숙과정중 토코페롤과 지방산의 변화)

  • Lee, In-Bog;Chang, Ki-Woon
    • Applied Biological Chemistry
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    • v.36 no.2
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    • pp.127-133
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    • 1993
  • The concentrations of tocopherols and compositions of fatty acids during germination and maturation of soybean seeds were determined by HPLC and GC. In germination stages, when the length of seedling axis was about 10 cm, the contents of total tocopherols and lipids were the highest. At the early phase of pod filling on field condition, the concentration of ${\delta}-tocopherol$ in soybean seeds was the highest, but, in further pod filling, the content of ${\delta}-tocopherol$ decreased continuously, and ${\alpha}-$ and ${\gamma}-tocopherol$ increased. Accumulation of oil during pod filling seems to be determined at the beginning. There seem positive correlations between several tocopherol homologues and fatty acids.

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A Study on Construction and Applicability on of Smart Pole Measuring System for Monitoring Steep Slope Sites (급경사지 모니터링을 위한 스마트폴 계측시스템 구축 및 적용성 연구)

  • Lee, Jin-Duk;Chang, Ki-Tae;Bhang, Kon-Joon
    • Journal of Korean Society of Disaster and Security
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    • v.7 no.2
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    • pp.1-8
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    • 2014
  • Smart Pole Measurement System was constructed with not only the core sensors of a GNSS receiver, a TRS sensor and a soil moisture sensor but supplementary installation of power supply and radio communication for monitoring steep slope sites. Also a data processing software for displacement extraction and visualization was developed. Smart Pole Measurement sensor is composed of a GNSS antenna at the top of the pole, a TRS sensor and a gyro sensor vertical below right of the antenna and a soil moisture sensor at the bottom of the pole. The sensor combination extracts not only ground combination in real time but transltion, slide, settlement and soil moisture content. This measuring/monitoring system which cosists of data receiving part, data collection/transfer part and data processing part was built to exercise their functions and then test measuring/monitoring was conducted by introducing artificial displacement and the results were analyzed to evaluate field applicability.

Effect of Water Treatment Sludge on Growth of Rice Seedling (수도 유묘생장에 미치는 정수장슬러지 처리효과)

  • Lee, In-Bog;Lim, Jae-Shin;Chang, Ki-Woon
    • Korean Journal of Environmental Agriculture
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    • v.25 no.4
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    • pp.382-385
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    • 2006
  • To know the effect of water treatment sludge (WTS) as a rice seedling culture soil, rice seeds are sown, germinated and grown on the culture soils mixed with different ratios of WTS to sand (100:0, 50:50, 30:70, respectively), and their growth effects was compared to that of control, commercial culture soil. When WTS is used as a culture soil for rice, the length and weight of the top part of rice seedling somewhat decreased than those of control treatment while their root length and weight in all WTS treatments significantly increased. Although phosphorus and potassium uptake of rice seedling in WTS treatments was slightly decreased, WTS treatment showed to develop root growth which is necessary in the seedling stage of all plane. Such a stimulatory effect on root growth of rice seedling was significant in the mixture ratio of 50% WTS to 50% sand.

Studies on the Mechanism of Positive Inotropic Action of Higenamine -Interrelationship with calcium- (Higenamine의 강심작용기전(强心作用機轉)에 관(關)한 연구(硏究) -$Ca^{++}$과의 상호작용(相互作用)-)

  • Chang, Ki-Chul;Lim, Jung-Kyoo;Park, Chan-Woong;Kim, Myung-Suk
    • The Korean Journal of Pharmacology
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    • v.17 no.2
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    • pp.7-16
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    • 1981
  • Higenamine ($Ca_{26}H_{17}No_3$. HCI, d1-1- (4-hydroxybenzyl) -6,7-dihydroxy-1,2,3,4-tetrahydroiso-quinoline hydrochloride), which has recently teen isolated from the Aconite root, was known to the cardiotonic component of the Aconite root. The positive inotropic effect of Higenamine was observed in the isolated electrically driven left atrium from rabbits with respect to the influences of extracellular calcium and of calcium antagonists, e.g. $La^{+++}$ and verapamil. A synergistic relation in the positive inotropic effect could be demonstrated between Higenamine and extra cellular calcium. The inotropic potency of $10^{-7}\;g/ml$ Higenamine was equivalant to that of 0.058 mM of calcium in the medium. In the preparation, of which contractility had been reduced by the treatment of $La^{+++}(10^{-5}-10^{-4}M)$ and verapamil$(2{\times}10^{-7}-10^{-6}M)$, Higenamine was able to restore the contractility. These results indicated that one of the possible mechanism of positive inotropism of Higenamine was to accelerate the influx of calcium from the extracellular space through the sarcolemma.

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Analysis of Fog using the FSSP-100 and Microwave Radiometer at Daegwallyoung in the 2003 winter case (전방산란스펙트로미터 (FSSP-100)와 마이크로 레디오메타를 이용한 2003년도 대관령 동계 안개 사례 분석)

  • Cha, Joo-Wan;Chang, Ki-Ho;Jeong, Jin-Yim;Park, Gyun-Myeong;Yang, Ha-Young
    • Atmosphere
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    • v.15 no.3
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    • pp.167-178
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    • 2005
  • Using the FSSP-100(FSSP) and Microwave Radiometer (MWR), the fog and clear day characteristics (the size and number concentration of fog particles and the liquid water content) have been measured and analyzed at Daegwallyoung observation site ($37^{\circ}41^{\prime}N$, $128^{\circ}45^{\prime}E$) during 27 - 30 November 2003 (fog day) and 19 January 2004 (clear day). During the fog days, the measured fog-particle size by using FSSP is 0.8~8.4 ${\mu}m$, which is similar to the WMO typical value, the fog number concentration varies from 121 to 200 count ($No./cm^2$) and the fog liquid water content from $0.018g/m^3-0.1g/m^3$ in the site. The precipitable water vapor obtained by the MWR, showing the correlation coefficient $R^2$=0.83 between the total precipitable water vapor obtained from the radio sonde and MWR, shows the larger amount (0.75-8.3 cm) during the fog days than the clear-sky data (0.2 cm).

Changes of Soil Physico-chemical Properties by Repeated Application of Chicken and Pig Manure Compost (계분 및 돈분퇴비의 연용에 의한 토양의 물리화학성 변화)

  • Chang, Ki-woon;Cho, Sung-hyun;Kwak, Jung-ha
    • Journal of the Korea Organic Resources Recycling Association
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    • v.7 no.1
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    • pp.23-30
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    • 1999
  • The changes of soil physico-chemical properties were investigated in the sandy loam soil amended with various application rates of chicken and pig manure composts. After repeated application of the composts for 3 years, total nitrogen content in soil treated with applied 120Mg/ha of chicken and pig manure composts was 2.1 g/kg equally. Organic matter content was 38.8 and 39.1 g/kg, available phosphate content was 602 and 585 mg/kg, and cation exchange capacity(CEC) was 10.1 and 12.4 cmol/kg in chicken and pig manure compost 120 Mg/ha treatment, respectively. Exchangeable K, Ca, Na, Mg contents, and electrical conductivity(EC) increased with the amount of applied compost. Also, with increased amount of applied compost, porosity of soil increased, but hardness, bulk density and Y value decreased.

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Study on the Improvement of Soil for High Efficient and Sustainable Agriculture-I. Effect of Repeated Application of Chicken and Pig Manure Composts on Tomato Growth and Soil Physico-chemical Properties (지속적 농업을 위한 고성능 토양의 개발 연구-I. 계분 및 돈분퇴비의 연용이 방울토마토(Lycopersicum esculentum var. cerasiforme)의 생육 및 토양의 이화학성에 미치는 영향)

  • Cho, Sung-Hyun;Lee, In-Bog;Chang, Ki-Woon
    • Applied Biological Chemistry
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    • v.41 no.6
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    • pp.451-456
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    • 1998
  • To find out the repeated application effect of chicken and pig manure composts on tomato growth and soil physico-chemical properties, different rates of the composts were applied to greenhouse soils with low fertility for 3 years and tomato was grown annually. As application rate of compost increased, the growth and fruit yield of tomato increased markedly, and there are also a little increase in sugar content in fruit juice and weight per fruit. When only compost was applied, however, physical and chemical properties in soil showed to be unbalanced such as significantly low bulk density and hardness, and high porosity as well as high organic matter and exchangeable K content, and low exchangeable Ca content than those of optimum range for soil diagnosis. Therefore mixed use of compost and chemical fertilizer is more promising way than the only use of compost to make suitable physico-chemical properties for tomato growth.

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Transition of Marker Enzymes of Rat Hepatocyte Organelles in Culture (배양중 흰쥐 간세포의 새포소기관 표지효소의 변천)

  • Song, In-Hwan;Kim, Joo-Yung;Sung, Eon-Ki;Lee, Yung-Chang
    • Journal of Yeungnam Medical Science
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    • v.6 no.2
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    • pp.133-140
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    • 1989
  • To investigate recovery, growth, and activity of hepatocyte in primary culture after cell separation, the authors followed up the marker enzyme activities of golgi complex, mitochondria and biologic membrane. Thiamine pyrophosphatase, the marker enzyme of golgi complex, activity approached the level of long term culture at 4th day. Succinate dehydrogenase, the marker enzyme of mitochondria, activity decreased with time, then it maintained constant level after 4th day. Alkaline phosphatase, the marker enzyme of biological membrane, activity increased from 3rd day, and after 5th day it showed strong reaction. These data suggested that hepatocytes were stabilized and recovered normal activity 4 day after cell separation, but the main secretory function was speculated to be reduced in culture.

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Performance Analysis of Synchronization Clock with Various Clock States Using Measured Clock Noises in NG-SDH Networks (NG-SDH망에서 측정된 클럭잡음을 이용한 다양한 클럭상태에 따른 동기클럭 성능분석)

  • Lee, Chang-Ki
    • The KIPS Transactions:PartC
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    • v.16C no.5
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    • pp.637-644
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    • 2009
  • A study about performance analysis of synchronization clock using measured clock noises is required. Therefore this paper executed the study for performance analysis of synchronization clock and acquirement of maximum number of network node with various clock states using measured clock noises in NG-SDH networks. Also this paper generated a suitable clock model using measured clock noises, and carried out simulations with various clock states. Through the simulation results, maximum numbers were 80 or more network nodes in normal state, and were below 37 nodes in short-term phase transient(SPT) state, and were 50 or more in long-term phase transient(LPT) state. Accordingly this study showed that maximum numbers to meet ITU-T specification were below 37 network nodes in three clock states. Also this study showed that when SPT or LPT states occur from NE network before DOTS system, synchronization source must change with other stable synchronization source of normal state.