• 제목/요약/키워드: Science and engineering

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Pharmacokinetics of oxytetracycline in rabbits after intravenous and intramuscular administrations (토끼에서 oxytetracycline의 정맥 및 근육 투여시의 약물동태학)

  • Kim, Eun-jung;Yun, Hyo-in;Park, Seung-chun;Oh, Tae-kwang;Cho, Chun-hyung
    • Korean Journal of Veterinary Research
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    • v.34 no.2
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    • pp.259-266
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    • 1994
  • The study was carried out to determine the pharmacokinetic parameters after intravenous(iv) and intramuscular(im) administration (10mg/kr) in healthy rabbits. The results obtained through the experiments were summarized as follows: 1. Bioassay (Bacillus cereus 11778) was evaluated very useful for the determination of oxytetracycline(OTC) in the rabbit serum and tissues, with the detection limit of $0.125{\mu}g/ml$. 2. The pharmacokinetic profiles of OTC (10mg/kg, iv) in rabbits were best described with a two compartment open model $(C=29.5e^{-4,3t}{\pm}3.6^{-0.2t})$, whereas that of OTC (10mg/kg, im) showed a one compartment curve fitting. 3. Following iv administration, a rapid distribution phase was predominant [$t_{\frac{1}{2}}({\alpha}):1.43{\pm}0.98hr$ (♂), $0.5{\pm}0.1hr$(♀)], and then more slow elimination phase ensued [$t_{\frac{1}{2}}({\beta}):4.52{\pm}0.76hr$(♂), $7.32{\pm}2.52hr$(♀)]. Other computer generated pharmacokinetic values were as follows:C1 [$67.76{\pm}18.59ml/kg/h$(♂), $76.03{\pm}22.98ml/kg/h$ (♀)] Vd [$257.74{\pm}180.47ml/kg$ (♂), $92.33{\pm}23.62$ (♀)] AUC [$25.6{\pm}4.44mgh/L$ (♂), $39.6{\pm}12.13mgh/l$ (♀)]. There were no statistical significance between both sexes for all the parameters at the confidence level of 95%. 4. After im administaration, the absorption from the injection sites was very rapid [ Ka:$0.18{\pm}0.03h^{-1}$ (♂), $0.24{\pm}0.02h^{-1}$ (♀)] followed by a monoexponential elimination fashion. The time to peak blood level (Tmax) were calculated $1.64{\pm}0.15hr$ and $1.34{\pm}0.24hr$, in the male and female, respectively. The peak levels (Cmax) at the corresponding time were $1.69{\pm}0.23{\mu}g/ml$ (♂) and $2.08{\pm}0.16{\mu}g/ml$ (♀), with no statistical differences (p>0.05).

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The study on corrosion of the inner area of closed box-girder for unpainted weathering steel bridges (무도장 내후성 강 교량의 밀폐형 박스거더 내부의 부식에 대한 고찰)

  • Ma, Seung-Hwan;Noh, Young-Tai;Jang, Gun-Ik
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.16 no.4
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    • pp.2391-2400
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    • 2015
  • Weather proof steels are used for steel bridges due to its high corrosion resistance under atmospheric conditions. However, instead of forming stabilized rust layers, general rust occurs on weather proof steels under high humidity condition close to seawater or shady places. In Japan, therefore, they perform rust stabilization treatment instead of unpainted treatment due to severe atmospheric conditions. However, most of domestic weather proof steels were constructed unpainted in the form of closed box-girder, which makes the periodical repetition of dry and wet hard to occur. For the steel bridges constructed on the Han river, the evaporation of water, dew condensation due to temperature change, and stagnant water due to rain affect harmfully on the formation of passive film on weather proof steels. Thus, in this research, in order to analyze corrosion properties inside the closed box-girder for the unpainted weather proof steel bridge in the waterworks safety zone, multiple ways of analysis such as observation with eyes, cellophane-tape test, steel thickness measurement, surface corrosion potential measurement, electron microscope analysis, and X-ray diffraction analysis of the rust were performed. As a result, unstable rust layer was observed inside the closed box-girder, and severe corrosion was observed on the top and bottom of the flanges due to the effects of stagnant water caused by rain, dew condensation, and de-icing materials.

Study of Spin Jig Development for Cleaning of the PCB component (PCB기판 세척용 스핀 지그개발에 관한 연구)

  • Lee, Seung-Chul;Park, Suk-Chul
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.15 no.8
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    • pp.4736-4741
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    • 2014
  • This study examined PCB component cleaning on a PCB component surface, which has defects of precipitation type washing (existing rinse method), sealant and foreign material formed in the adhesive process that could not be removed easily. The spin jig was developed for PCB component cleaning, in which the PCB component settled down, to solve the conventional problem of the removal of foreign material with the centrifugal force by high speed rotation. The results are as follows. With decreasing fraction defect in PCB component washing, the development and substrate damage decreased by more than 80% according to the abstergent in the rotary type using the centrifugal force in the existing precipitation type. When the base plate showed a large difference with the time to include the process after washing the design using the existing method, easy attachment and separation of the PCB component could be possible. The washing time was enhanced 90% compared to the existing time. The reliability of the security and washing collaboration of the design and stability of the cleaning process could be secured so that there was no phenomenon of secession, the PCB component fixed for a cleansing rotation jig could maintain a fixed force by the centrifugal force. The stability and reliability of the washing process and the defective rate could be improved to less than 1%.

Design and implementation of a 3-axis Motion Sensor based SWAT Hand-signal Motion-recognition System (3축 모션 센서 기반 SWAT 수신호 모션 인식 시스템 설계 및 구현)

  • Yun, June;Pyun, Kihyun
    • Journal of Internet Computing and Services
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    • v.15 no.4
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    • pp.33-42
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    • 2014
  • Hand-signal is an effective communication means in the situation where voice cannot be used for expression especially for soldiers. Vision-based approaches using cameras as input devices are widely suggested in the literature. However, these approaches are not suitable for soldiers that have unseen visions in many cases. in addition, existing special-glove approaches utilize the information of fingers only. Thus, they are still lack for soldiers' hand-signal recognition that involves not only finger motions, but also additional information such as the rotation of a hand. In this paper, we have designed and implemented a new recognition system for six military hand-signal motions, i. e., 'ready', 'move', quick move', 'crawl', 'stop', and 'lying-down'. For this purpose, we have proposed a finger-recognition method and motion-recognition methods. The finger-recognition method discriminate how much each finger is bended, i. e., 'completely flattened', 'slightly flattened', 'slightly bended', and 'completely bended'. The motion-recognition algorithms are based on the characterization of each hand-signal motion in terms of the three axes. Through repetitive experiments, our system have shown 91.2% of correct recognition.

A Study on the Consideration Factors for State-of-the-art Defense Business Orders from Chasm Marketing Perspective (캐즘마케팅 관점으로 바라본 최첨단 무기체계 수주를 위한 고려요소에 관한 연구)

  • Kim, Young-Bok;Kim, Hong-Ki;Lee, Seung-Hee
    • Journal of Digital Convergence
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    • v.14 no.11
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    • pp.81-90
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    • 2016
  • In the civil market, companies launch new products when the acquired innovations are ready, but in defense, customer requests the innovation applied weapon systems. The technology adoption cycle model takes unusual form of market like inverse chasm takes technology inversely. This thesis describes an inverse chasm from the perspective of technology adoption cycle, equipped product model, and technical progress S-curve. As a way to overcome the inverse chasm, considering factors like a self-investment demo model, customer needs, and the temporary chasm expanding phenomenon are derived. And order-effective relationship analysis and chasm marketing strategy are suggested. Especially securing the core technologies and possibility for equipped product by developing self-investment demo model are identified as a good marketing strategy of chasm. This analysis and strategy suggest the policy implications for preemptive advantage of market positioning in the procurement process of defense, discontinuous innovation technology applied on.

α-feature map scaling for raw waveform speaker verification (α-특징 지도 스케일링을 이용한 원시파형 화자 인증)

  • Jung, Jee-weon;Shim, Hye-jin;Kim, Ju-ho;Yu, Ha-Jin
    • The Journal of the Acoustical Society of Korea
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    • v.39 no.5
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    • pp.441-446
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    • 2020
  • In this paper, we propose the α-Feature Map Scaling (α-FMS) method which extends the FMS method that was designed to enhance the discriminative power of feature maps of deep neural networks in Speaker Verification (SV) systems. The FMS derives a scale vector from a feature map and then adds or multiplies them to the features, or sequentially apply both operations. However, the FMS method not only uses an identical scale vector for both addition and multiplication, but also has a limitation that it can only add a value between zero and one in case of addition. In this study, to overcome these limitations, we propose α-FMS to add a trainable parameter α to the feature map element-wise, and then multiply a scale vector. We compare the performance of the two methods: the one where α is a scalar, and the other where it is a vector. Both α-FMS methods are applied after each residual block of the deep neural network. The proposed system using the α-FMS methods are trained using the RawNet2 and tested using the VoxCeleb1 evaluation set. The result demonstrates an equal error rate of 2.47 % and 2.31 % for the two α-FMS methods respectively.

The Crytal and Molecular Structure of Morpholinothiosemicarbazide (Morpholinothiosemicarbazide의 結晶 및 分子構造)

  • Chung Hoe Koo;Hoon Sup Kim;Hyun So Shin;Yungja Lee
    • Journal of the Korean Chemical Society
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    • v.17 no.2
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    • pp.105-114
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    • 1973
  • The crystal structure of morpholinothiosemicarbazide has been determined by single crystal X-ray analysis. The lattice constants are a = 4.19(2), b = 6.56(2) and c = 26.67(4)${\AA}$. The unit cell contains 4 molecules and the space group is$P2_12_12_1$. The atomic parameters have been refined by least-squares method to a final R value of 0.07, based on the 651 observed reflexions. The amino nitrogen atom forms hydrogen bonds to the sulfur atoms of the other molecules related by the two-fold screw axis parallel to the a-axis, the distances of the hydrogen bonds being 3.48 and 3.49${\AA}$. On the other hand, the imino nitrogen atom forms a hydrogen bond to the amino nitrogen atom of the other molecule related by the two-fold screw axis parallel to the a-axis, the distance of the hydrogen bond being 3.04${\AA}$. These three hydrogen bonds arrange the molecules around the two-fold screw axis. Apart from the hydrogen bonding system the structure is held together by van der Waals forces.

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Fluid Drag of a Trawl Net and Otter Board Spread in a Midwater Trawl (중층트롤 어구의 그물저항과 전개판 간격)

  • PARK Hae-Hoon;YOON Gab-Dong
    • Korean Journal of Fisheries and Aquatic Sciences
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    • v.34 no.3
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    • pp.238-244
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    • 2001
  • A method of estimating the fluid drag of a fishing gear and otter board spread in a midwater trawl on full scale was described by implementing a three-dimensional semi-analytic treatment of the towing cable (warp) of a trawl system with the field experiments obtained with the SCANMAR system. The shape of hand rope, bridle and float(or ground) rope attached behind otter boards in a horizontal plane was assumed to be of form $y_r=Ax_r^B$. The distance between otter boards (otter board spread) obtained by the three dimensional analysis of a towing cable must be equal to that obtained by the functional equation of the shape of ropes behind otter boards, The angle of attack of ropes which can be obtained from the functional equation enables one to estimate the fluid drag of trawl net (net drag) by subtracting the fluid drag of the hand rope and bridles from the drag component of the tension of hand rope attached just behind the otter boards.

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The Effects of Anti-Inflammatory Activities and Active Fractions Analysis of Ethanol Extract from Red Rose Petals (붉은 장미꽃잎 에탄올 추출물의 활성 분획물 분석 및 항염증 활성 효과)

  • Kim, Hyun Kyoung
    • The Journal of the Convergence on Culture Technology
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    • v.6 no.2
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    • pp.543-551
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    • 2020
  • Red rose petals are usually disposed but they are an abundant source of phenolics and traditionally used as food supplement and as herbal medicine. Of the Various phenolics, they are known to have anticancer, antioxidant, and anti-inflammatory properties. In this study, we investigated the anti-inflammatory effects of red rose ethanolic extracts(GRP) on lipopolysaccharide (LPS)-activated RAW 264.7 cells. The results demonstrated that pretreatment of GRP(500㎍/mL) significantly reduced NO production by suppressing iNOS protein expression in LPS-stimulated cells. Anti-inflammatory effects byred rose petal were observed in the following. Red rose petal inhibited the translocation of NF-κB from the cytosol to the nucleus via the suppression of IκB-α phosphorylation and also inhibited LPS-stimulated NF-κB transcriptional activity. These findings suggest that red rose petal exert anti-inflammatory actions and help to elucidate the mechanisms underlying the potential therapeutic values of red rose petal. Therefore, red rose petal could be regarded as a potential source of natural anti-inflammatory agents.

Effect of Foaming Agent Content on the Apparent Density and Compressive Strength of Lightweight Geopolymers (발포제 함량에 따른 경량 다공성 지오폴리머의 밀도와 강도 특성)

  • Lee, Sujeong;An, Eung-Mo;Cho, Young-Hoon
    • Journal of the Korean Recycled Construction Resources Institute
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    • v.4 no.4
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    • pp.363-370
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    • 2016
  • Lightweight geopolymers are more readily produced and give higher fire resistant performance than foam cement concrete. Lowering the density of solid geopolymers can be achieved by inducing chemical reactions that entrain gases to foam the geopolymer structure. This paper reports on the effects of adding different concentrations of aluminum powder on the properties of cellular structured geopolymers. The apparent density of lightweight geopolymers has a range from 0.7 to $1.2g/m^3$ with 0.025, 0.05 and 0.10 wt% of a foaming agent concentration, which corresponds to about 37~60 % of the apparent density, $1.96g/cm^3$, of solid geopolymers. The compressive strength of cellular structured geopolymers decreased to 6~18 % of the compressive strength, 45 MPa of solid geopolymers. The microstructure of geopolymers gel was equivalent for both solid and cellular structured geopolymers. The workability of geopolymers with polyprophylene fibers needs to be improved as in fiber-reinforced cement concrete. The lightweight geopolymers could be used as indoor wall tile or board due to fire resistance and incombustibility of geopolymers.