• Title/Summary/Keyword: characteristic ratio

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A Study on Real-time Implementing of Time-Scale Modification (음성 신호 시간축 변환의 실시간 구현에 관한 연구)

  • Han, Dong-Chul;Lee, Ki-Seung;Cha, Il-Hawan;Youn, Dae-Hee
    • The Journal of the Acoustical Society of Korea
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    • v.14 no.2
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    • pp.50-61
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    • 1995
  • A time scale modification method yielding rate-modified speech while conserving the characteristic of speech was implemented in real-time using a goneral purpose digital signal processor. Time scale modification changed pronunciation speed only, producing a time difference between the input signal and the modified signal, making it impossible to implement it in real-time. In this thesis, a system was implemented to remove the time difference between the input and modified signals. Speech signals slowed down or speeded up by a physical time scale modification method, such as adjusting the motor speed of the cassett tape recorder, was used as the input signal. Physical modification that controled only the inter speed of the cassette tape player distorted the pitch period of the original speech. In this study, a real-time system was implemented so that the pitch-distorted speech was reconstructed back to the original by fractional sampling pitch shifting using an FIR filter, and this signal was time scale modified to match the cassette tape recorder motor speed using SOLA time-scale medification. In experiments using speech signals medifiedby the proposed method, results obtained using a 16-bit resolution ADSP2101 processor and using computer simulations employing floating point operations showed about the same average frame signal-to-noise ratio of about 20 dB.

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TEMPERAMENTAL CHARACTERISTICS OF ATTENTION DEFICIT HYPERACTIVITY DISORDER (주의력결핍 ${\cdot}$ 과잉운동장애아의 기질적 특성)

  • Cho, Soo-Churl;Kim, Dong-Hyun;Kim, Ja-Sung
    • Journal of the Korean Academy of Child and Adolescent Psychiatry
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    • v.4 no.1
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    • pp.114-123
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    • 1993
  • The authors applied Toddler Temperament Scale(TTS) to ADHD patient group, other disease group and normal control group to elucidate temperamental characteristics of ADHD patients in their toddler stage. 1) ADHD group showed significant difference from the control group in 'activity', 'rhythmicity', 'approach', 'adaptability', 'intensity', 'persistence' and 'threshold' categories. 2) ADHD group and other disease showed significant difference from the control group in 'adaptability' and 'persistence' categories. 3) ADHD group was significantly different from other disease group or control group in 'activity' and 'approach' categories. 4) In total scores of TTS, ADHD group and other diease group showed significant difference from control group. 5) Classification ratio of TTS for ADHD by discriminant analysis was 84.3%. Above results suggest that the ADHD patients may reveal characteristic traits in their toddler stage Further research should be focused on the development and refinement of assessment tools for the early detection and prevention for ADHD.

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Numerical study on the effect of viscoelasticity on pressure drop and film thickness for a droplet flow in a confined microchannel

  • Chung, Chang-Kwon;Kim, Ju-Min;Ahn, Kyung-Hyun;Lee, Seung-Jong
    • Korea-Australia Rheology Journal
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    • v.21 no.1
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    • pp.59-69
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    • 2009
  • The prediction of pressure drop for a droplet flow in a confined micro channel is presented using FE-FTM (Finite Element - Front Tracking Method). A single droplet is passing through 5:1:5 contraction - straight narrow channel - expansion flow domain. The pressure drop is investigated especially when the droplet flows in the straight narrow channel. We explore the effects of droplet size, capillary number (Ca), viscosity ratio ($\chi$) between droplet and medium, and fluid elasticity represented by the Oldroyd-B constitutive model on the excess pressure drop (${\Delta}p^+$) against single phase flow. The tightly fitted droplets in the narrow channel are mainly considered in the range of $0.001{\leq}Ca{\leq}1$ and $0.01{\leq}{\chi}{\leq}100$. In Newtonian droplet/Newtonian medium, two characteristic features are observed. First, an approximate relation ${\Delta}p^+{\sim}{\chi}$ observed for ${\chi}{\geq}1$. The excess pressure drop necessary for droplet flow is roughly proportional to $\chi$. Second, ${\Delta}p^+$ seems inversely proportional to Ca, which is represented as ${\Delta}p^+{\sim}Ca^m$ with negative m irrespective of $\chi$. In addition, we observe that the film thickness (${\delta}_f$) between droplet interface and channel wall decreases with decreasing Ca, showing ${\delta}_f{\sim}Ca^n$ Can with positive n independent of $\chi$. Consequently, the excess pressure drop (${\Delta}p^+$) is strongly dependent on the film thickness (${\delta}_f$). The droplets larger than the channel width show enhancement of ${\Delta}p^+$, whereas the smaller droplets show no significant change in ${\Delta}p^+$. Also, the droplet deformation in the narrow channel is affected by the flow history of the contraction flow at the entrance region, but rather surprisingly ${\Delta}p^+$ is not affected by this flow history. Instead, ${\Delta}p^+$ is more dependent on ${\delta}_f$ irrespective of the droplet shape. As for the effect of fluid elasticity, an increase in ${\delta}_f$ induced by the normal stress difference in viscoelastic medium results in a drastic reduction of ${\Delta}p^+$.

The Role of Serum Pepsinogen in Detection of Gastric Cancer (위암 검출에서 혈중 Pepsinogen검사의 의의)

  • Ryu, Hyong-Kyun;Park, Jeon-Woo;Lee, Keon-Ho;Jeon, Chang-Ho;Lee, Ho-Joon;Chae, Hyun-Dong
    • Journal of Gastric Cancer
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    • v.9 no.4
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    • pp.167-171
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    • 2009
  • Purpose: This study was done to determine the usefulness of serum pepsinogen (PG) levels as a screening method for gastric cancer, and to assess the relationships between serum PG and clinicopathologic factors of gastric adenocarcinoma. Materials and Methods: Serum PG concentrations were measured in 94 subjects who were classified into (a) a control group (50 subjects) without abnormal endoscopic finding on a health checkup, or (b) a gastric cancer group (44 subjects) who had surgery at Daegu Catholic University Hospital between Nov. 2008 and May 2009. Receiver operator characteristic curves were utilized to select the most suitable test. Using different cutoff points, sensitivity and specificity were calculated. We compared preoperative serum PG levels with several clinicopathologic findings for patients with gastric adenocarcinoma. Results: The Serum PG I:II ratio was the most useful as a screening test. The sensitivity and specificity of PG screening for gastric cancer were, respectively, 81.8% and 82%. The cut off point correlated with the type of intestinal cancer (Lauren classification; P=0.003), tumor stage (P=0.001), and gastric adenocarcinoma with peritumoral chronic atrophic gastritis (P=0.036). Conclusion: Serum PG levels were found to be a potentially useful screening test and to correlate with clinicopathologic factors in gastric cancer patients. But, in order to use serum PG found in a health checkup for gastric cancer as a clinical application a large scale study is recommended.

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Optimization of Corrosion Properties of Ti/TiO2/IrO2-RuO2 Electrodes via Taguchi Method (Taguchi법을 이용한 Ti/TiO2/IrO2-RuO2전극의 부식특성 최적화)

  • 이득용;채경선;최형기;예경환;안중홍;송요승
    • Journal of the Korean Ceramic Society
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    • v.39 no.6
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    • pp.582-588
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    • 2002
  • IrO$_2$-RuO$_2$ films were deposited on plasma sprayed TiO$_2$ buffer layer above Ti metal by sol-gel and dip-coating method. Organic vehicle (ethyl cellulose and $\alpha$-terpineol) and glass frit were added to improve adherence of the coatings. Taguchi method and L$_{18}$ (2$^1$$\times$3$^{7}$ ) orthogonal arrays were evalvated in terms of current density to determine the optimal combination of levels of factors that best satisfy the bigger is better quality characteristic. The observed conditions were as fellows: ethyl cellulose (100 cp), drying temperature and time (17$0^{\circ}C$,20 min), heat treatment temperature and time (75$0^{\circ}C$,10 min), the weight ratio of IrO$_2$-RuO/powders to glass frit (99:5), final heat treatment time (120 min) and flow rate of air (5 sccm), respectively. ANOVA analysis suggested that the influence of the factors within $\alpha$= 0.1 was significant with a 90% confidence level.

The Processing Conditions of Extracts from Rapid Fermented Anchovy Sauce (속성멸치간장엑기스분의 가공조건)

  • Lee, Eung-Ho;Kim, Jin-Soo;Ahn, Chang-Bum;Lee, Kang-Hee;Kim, Myung-Chan;Chung, Bu-Kil;Park, Hee-Yeol
    • Journal of the Korean Society of Food Science and Nutrition
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    • v.18 no.2
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    • pp.167-174
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    • 1989
  • AS a part of investigation to use anchovy more effectively as food source, this work was undertaken the processing conditions of extracts from rapid fermented anchovy sauce. To prepare rapid fermented products, the chopped anchovy was mixed with 50% water (w/w), and then hydrolyzed by autolysis or addition of koji under different conditions of hydrolysis. The optimal conditions for hydrolysis of chopped anchovy were revealed $50^{\circ}C$, 6 hours, pH 8.0 by autolysis, and ,$50^{\circ}C$, 6 hours, pH 7.0 by addition of 10% koji, respectively. But, pH control was not much beneficial in increasing yield. The effect of soybean protein isolote for improvement of bitter taste was also tested. The reasonable amount of added soybean protein isolate was revealed 5% on the weight basis of the chopped anchovy. The reaction mixture hydrolyzed under optimal conditions were added with 1% onion powder (w/w), 1% garlic powder(w/w) and 1% red pepper powder(w/w) for masking fishy odor, inactivated for 20 min at $100^{\circ}C$, and then centrifuged for 20 min at 4,000 rpm. The supernatant liquor was filtrated and evaporated to 50%(v/v). finally, table salt was added for bateriostatic effect and characteristic taste of rapid fermented products. the reasonable amount of added table salt was reversed 15% on the volume basis of the evaporated liquor. The hydrolysis ratio of product made by addition of water, product made by addition of koji and water, and product made by addition of soybean protein isolate, koji and water hydrolyzed under optimal conditions were 58.4%, 82.1% and 86.2%, respectively.

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A Study on Ash Fusibility Temperature of Domestic Thermal Coal Implementing Thermo-Mechanical Analysis (TMA를 이용한 국내 발전용 탄의 용융점 변화에 대한 연구)

  • Lee, Soon-Ho;Lim, Ho;Kim, Sang Do;Jeon, Chung-Hwan
    • Korean Chemical Engineering Research
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    • v.52 no.2
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    • pp.233-239
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    • 2014
  • The slagging which generated from ash deposition on furnace wall and tube in boiler reduces the heat transfer efficiency and damages to safety of boiler. The slag flow behavior in boiler is affected by melting temperature which is related to ash compositions. In this study, the behavior of slag is researched by using ash fusibility test, called TMA (Thermo-Mechanical Analysis). The technique measures the percentage shrinkage as the function of temperature, T25%, T50%, T75%, T90%. These temperatures indicate different stages of melting. Then, the effect of ash chemical compositions measured from XRF (X-ray Fluorescence Spectrometer) to ash fusion temperatures is discussed. Among the chemical compositions, refractory and fluxing influence on ash fusibility is described. High levels of refractory component and limited amount of fluxing components ($Fe_2O_3$, $K_2O$, CaO) increase overall melting temperatures. High $SiO_2/Al_2O_3$ ratio decrease high melting temperatures (T75%, T90%). Meanwhile, the presence of reasonable levels of fluxing components reduces overall melting temperature. A presence of fluxing component such as $K_2O$ and CaO is found to decrease the T25% values significantly. From this research, it is possible to make a reasonable explanation and prediction of ash fusion characteristic from analysis of TMA results and ash chemical compositions.

Characteristic of ITO-Ag-ITO multilayer thin films grown by linear facing target sputtering system (선형대향타겟 스퍼터로 성장시킨 ITO-Ag-ITO 다층박막의 특성 연구)

  • Jeong, Jin-A;Choi, Kwang-Hyuk;Lee, Jae-Young;Lee, Jung-Hwan;Bae, Hyo-Dae;Tak, Yoon-Heung;Ye, Min-Su;Kim, Han-Ki
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 2008.11a
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    • pp.66-66
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    • 2008
  • 본 연구에서는 ITO/Ag/ITO 다층 박막을 유기발광소자와 플렉시블 광전소자의 전극으로 적용하기 위하여 선형 대항 타겟 스퍼터(Linear facing target sputter) 시스템을 이용하여 성막하였고, ITO/Ag/ITO 다층박막의 전기적, 광학적, 구조적 특성을 분석하였다. 선형 대항 타겟 스퍼터 시스템은 강한 일방항의 자계와 타겟에 걸린 음극에 의해 전자의 회전, 왕복 운동이 가능해 마주보는 두 ITO 타겟 사이에 고밀도의 플라즈마를 구속 시켜 플라즈마 데미지 없이 산화물 박막을 성막시킬 수 있는 장치이다. 대항 타겟 스퍼터 시스템을 이용하여 성막한 ITO 전극을 DC power, working pressure, Ar/O2 ratio 에 따른 특성을 각각 분석하였다. glass 기판위에 최적화된 ITO 전극을 bottom layer로 두고, bottom ITO layer 위에 thermal evaporation 을 이용하여 Ag 박막을 6~20nm의 조건에 따라 두께를 다르게 성막하고, Ag 박막을 성막한 후에 다시 bottom ITO 전극과 같은 조건으로 ITO 전극을 top layer로 성막 하였다. 두 비정질의 ITO 전극 사이에 매우 앓은 Ag 박막을 성막 함으로 해서 glass 기판위에 ITO/Ag/ITO 다층 박막전극은 매우 낮은 저항과 높은 투과도를 나타낸다. ITO/Ag/ITO 박막의 전기적 광학적 특성을 보기 위해 hall measurement와 UV/visible spectrometer 분석을 각각 진행하였다. ITO/Ag/ITO 다층 박막 전극이 매우 얇은 두께임에도 불구하고 $4\Omega$/sq.의 낮은 면저항과 85%의 높은 투과도를 나타내는 이유는 ITO/Ag/ITO 전극 사이에 있는 Ag층의 표면 플라즈몬 공명 (SPR) 현상으로 설명할 수 있다. ITO/Ag/ITO 전극의 Ag의 거동을 분석 하기위해 FESEM분석과 synchrotron x-ray scattering 분석을 하였다. ITO/Ag/ITO 전극의 Ag층이 islands의 모양에서 연속적으로 연결되는 변화과정 중에 SPR현상이 일어남을 알 수 있다. 여기서, 대항 타겟 스퍼터 시스템을 이용하여 성막한 ITO/Ag/ITO 다층박막을 OLED 또는 inverted OLEDs의 top 전극으로의 적용 가능성을 보이고 있다.

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Quality Characteristics of Yanggaeng containing Various Amounts of Loquat Fruits Puree (비파 퓨레 첨가량을 달리한 양갱의 품질특성)

  • Kwon, Soon-Yong;Chung, Chang-Ho;Park, Ki-Bong
    • Culinary science and hospitality research
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    • v.21 no.2
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    • pp.75-84
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    • 2015
  • In this study, a Yanggaeng with added loquat fruits puree was developed and studied on quality characteristics. The mixed ratio were 0%, 20%, 40%, 60%, 80%, 100% of loquat fruits puree. Loquat fruits puree have 83.49% of water, 0.36% of crude protein, 0.04% of crude fat, 0.46% of crude ash, $14.3^{\circ}Brix$ of sweetness, 75.10(mg/kg) of polyphenol and 4.01 of pH. The water contents of Yanggaeng were 41.78~53.37%, and showed significant increase (p<0.001). The sugar contents of Yanggaeng were increased from $28.7^{\circ}Brix$ at control group to $36.0^{\circ}Brix$ at 100% mixing group (p<0.001), while pH were decreased from 6.4 at control group to 4.26 to 6.4 at 100% mixing group. In color, the brightness (L-value) gradually decreased from 72.69 at control group to 43.64 at 100% mixing group (p<0.001), the redness (a-value) of control group was the lowest by -1.72 while 100% mixing group was the highest by 8.64 (p<0.001). The yellowness (b-value) of control group was 15.91 while that of 100% mixing group was 21.98 (p<0.001). The DPPH radical scavenging activity of control group was the lowest by 9.24% while that of the group 100% mixing was the highest by 46.17%. Total polyphenol was not detected from control group and 20% mixing groups, and 100% mixing group was The highest by 16.69 mg/100 g (p<0.001). Preference test showed the groups with mixing loquat fruits puree 60% or more were preferred (p<0.001) in color. There were no significant difference from sweet taste but sour taste of 100% mixing group was The highest by 4.85 (p<0.01). For texture and overall preference the most preferred groups were the groups of mixing of 60% and 80% of loquat fruits puree.

A Study on Unstable Phenomenon of Space Truss Structures Considering Initial Imperfection (트러스형 공간구조물의 초기 불완전을 고려한 불안정 현상에 관한 연구)

  • Lee, Jin-Hyouk;Baik, Tai-Soon;Shon, Su-Deok;Kim, Seung-Deog;Kang, Moon-Myung
    • Journal of Korean Association for Spatial Structures
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    • v.4 no.2 s.12
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    • pp.63-71
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    • 2004
  • The structural space is gradually wide and is wanting agreeable environment by the requirement and necessity of people who lives modem stage. The building coincides with such requirements and is the high rise building actual circumstances which is doing ultra-large. The confirmed report of the technology to organize great merit is becoming currently considerably important issue in constructing a building field. Thus, this paper examine closely for nonlinear unstable taking a picture uneasiness height of prosperity considering to initial imperfection by a numerical method with a space frame structure of discrete system in large space structure. Based on previous investigation method, this paper induce nodal stiffness matrix of solid truss elements considering geometrical nonlinear using finite element method. In this paper, three types of space structure considered; i) 1-free node space structure, ii) 2-free node space structure, iii) multi-free node space structure. It apply the above examples to a nonlinear program, next, grasp the characteristic of an unstable conduct and the result was a clearing low.

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