• Title/Summary/Keyword: type of defects

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Electrical Conductivity of the System NiO-$Y_2O_3$ (NiO-$Y_2O_3$계의 전기전도성)

  • Jae Shi Choi;Keu Hong Kim;Won Yang Chung
    • Journal of the Korean Chemical Society
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    • v.30 no.1
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    • pp.27-32
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    • 1986
  • Electrical conductivities of NiO-$Y_2O_3$ systems containing 0.8, 1.6, and 3.2 mol% NiO have been measured in the temperature range of 400 to 1100$^{\circ}$C at $PO_2$'s of 1 ${\times}10^{-5}$ to 2 ${\times}10^{-1}$ atm. Plots of $log\sigma$ vs 1/T at constant $PO_2$'s are found to be linear with an inflection at temperature around 650$^{\circ}$C. The slopes are steeper in the high temperature region above 650$^{\circ}$C than in the low temperature region below 650$^{\circ}$C. The average activation energies are 41.8kcal/mol in the high temperature region and 12.5kcal/mol in the low temperature region. $PO_2$'s dependence value, 1/n, is 1/5.1~1/5.4 in the high temperature region and 1/5.9~1/6.2 in the low temperature region. The NiO-$Y_2O_3$ systems are found to be an electronic p-type semiconductor. The predominant defects in the systems are believed to be triply ionized yttrium vacancy in the high temperature region and doubly ionized oxygen interstitial in the low temperature region. Ionic contribution to the total conductivity is found from ${\sigma}^{\propto}PO_2$ in the temperatures below 650$^{\circ}$C.

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Modified Fontan Operation: Physio-anatomic Causes of Low Cardiac Output and Persistent Pleural Effusion (Fontan 수술후 저심장박출증 및 지속성 흉막 삼출액이 발생되는 해부생리학적 원인)

  • Han, Jae-Jin;Seo, Gyeong-Pil
    • Journal of Chest Surgery
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    • v.23 no.2
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    • pp.213-221
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    • 1990
  • We have experienced 62 cases of modified Fontan operations in Seoul Nat’l University Hospital from Apr. 1986 to Jul. 1989, They were 38 males and 24 females, and their age was ranged from 16 months to 15.5 years of age. [mean age : 5.73$\pm$2.99 years] There were 16 operative deaths and 2 late deaths, therefore 29% of overall mortality. Their diagnoses were as follows; 28 single ventricle, 11 tricuspid atresia, 6 DORV with LV hypoplasia, 3 pulmonary atresia with hypoplastic RV, 3 TGA with hypoplastic RV, 3 cor\ulcornerGA with hypoplastic LV and PA, 6 AV canal defects with PA, and 2 others. Low cardiac output and pleural effusion were developed frequently, so we divide 40 patients into some groups to analyze the physiologic and anatomic causes of them. By the degree of the LCO, group A was no LCO[mean amount of inotropics used: 0-5 \ulcornerg/kg/min] with 17 cases, B mild LCO [5-10] with 11, C moderate to severe LCO but alive[>10] with 8, D severe LCO to death with 4 cases. For the pleural effusion, group 1 was to be removed the chest tube within 1 week with 8 cases, group II within 3 weeks with 21 cases, group III beyond 3 weeks with 12 cases. We considered their age, diagnosis, pulmonary artery size[PA index], pulmonary artery abnormality, palliative shunt, systemic ventricular type, pulmonary artery wedge pressure, as preoperative factors, and operative methods, and as postoperative factors, CVP, LAP, arrhythmia, thrombosis, atrioventricular valvular insufficiency, etc. In the view of LCO, pulmonary artery size and PCWP were statistically significant [P<0.05], and arrhythmia, A-V valve insufficiency were inclined to the group C and D Pleural effusion was influenced by the pulmonary artery size, pulmonary artery resistance, PCWP, and CVP significantly. [P<0.05] And arrhythmia, residual shunt, and A-V valvular insufficiency were inclined to group II and III, too. As a results, the followings are to be reminded as the important factors at the care of post-Fontan LCO, and persistent pleural effusion [1] pulmonary artery size, [2] pulmonary artery resistance, [3] PCWP, [4] CVP, [5] arrhythmia, [6] residual shunt, [7]A-V valvular insufficiency.

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Implement module system for detection sudden unintended acceleration (자동차급발진을 감지하기 위한 모듈 시스템 구현)

  • Cha, Jea-Hui;Jang, Jong-Wook
    • Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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    • 2017.05a
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    • pp.255-257
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    • 2017
  • These days automotive markets are launching models that include a variety of IT technologies. Tesla's Tesla model S and Google's unmanned automobiles are emerging one after another. This type of automobile with IT technology provides various convenience to the driver and the driver is getting benefit by various conveience services. on the contrary, it is also true that defects for errors in electronic components cause accidents that threaten the safety of drivers. There is a sudden unintended acceleration among these accidents. The cause of the accident is not clear yet, but the claim that the ECU device caused by the magnetic field causes accident of the car due is the most reliable. But, in Korea, when occur a car sudden unintended acceleration accident, the char maker often claims that an accident occurred due to driver's pedal malfunction. Also most drivers are responsible for the lack of grounds to refute. In this paper, the pedal operation image of the driver is acquired and the sensor is attached to the control part such as the excel and brake so as to discriminate whether the vehicle sudden unintended acceleration accident is the driver's pedal operation error or the fault of. i have implemented a system that can do this.

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The Improvement of Fabrication Process for a-Si:H TFT's Yield (a-Si:H TFT의 수율 향상을 위한 공정 개선)

  • Hur, Chang-Wu
    • Journal of the Korea Institute of Information and Communication Engineering
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    • v.11 no.6
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    • pp.1099-1103
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    • 2007
  • TFT's have been intensively researched for possible electronic and display applications. Through tremendous engineering and scientific efforts, a-Si:H TFT fabrication process was greatly improved. In this paper, the reason on defects occurring at a-Si:H TFT fabrication process is analyzed and solved, so a-Si:H TFT's yield is increased and reliability is improved. The a-Si:H TFT of this paper is inverted staggered type TFT. The gate electrode is formed by patterning with length of $8{\mu}m{\sim}16{\mu}m$ and width of $80{\sim}200{\mu}m$ after depositing with gate electrode (Cr). We have fabricated a-SiN:H, conductor, etch-stopper and photo-resistor on gate electrode in sequence, respectively. We have deposited n+a-Si:H, NPR(Negative Photo Resister) layer after forming pattern of Cr gate electrode by etch-slower pattern. The NPR layer by inverting pattern of upper Sate electrode is patterned and the n+a-Si:H layer is etched by the NPR pattern. The NPR layer is removed. After Cr layer is deposited and patterned, the source-drain electrode is formed. The a-Si:H TFT made like this has problems at photo-lithography process caused by remains of PR. When sample is cleaned, this remains of PR makes thin chemical film on surface and damages device. Therefor, in order to improve this problem we added ashing process and cleaning process was enforced strictly. We can estimate that this method stabilizes fabrication process and makes to increase a-Si:H TFT's yield.

Study on the Property of Guided Wave Signal Analysis according to Defect Shape of Small Size (소구경 튜브 결함 형태에 따른 유도초음파 신호 해석 특성에 관한 연구)

  • Gil, Doo-Song;Ahn, Yeon-Shik;Jung, Gye-Jo;Park, Sang-Gi;Kim, Yong-Gun
    • Journal of the Korean Society for Nondestructive Testing
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    • v.32 no.4
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    • pp.410-417
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    • 2012
  • Currently domestic thermal and nuclear power plants are comprised of many type's condenser and steam generator tubes to produce the electricity of good quality. There are some methods to inspect these tubes in the event that several defects were discovered in these facilities. Among many non-destructive methods, we used guided wave to inspect the soundness of tubes, because this method is very fast to detect the defect and very simple to install the equipment and also, can inspect up to the long range at a fixed point. Also, this method has a drawback that does not detect a very small size defect. So, we made an effort to overcome this drawback through the experimentation and signal analysis according to the size and shape of the defect through the manufacture of various artificial cracks capable to generate within the small size tube in the study and we anticipate that these detect limits can be overcome along with the development of the signal processing and manufacturing technology of the sensor for the inspection.

A Study on the Corrosivity according to Soil Characteristics and Electrolytic Protection for the Materials of Fuel Gas Pipe (토양 특성 및 전기방식에 따른 연료 가스용 강관의 부식 차이에 관한 연구)

  • Yim, Sang-Sik;Kim, Ji-sun;Ryu, Young-don;Lee, Jin-Han
    • Journal of the Korean Institute of Gas
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    • v.20 no.6
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    • pp.16-22
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    • 2016
  • Coating pipe(PLP) has been generally used in buried site for protecting the corrosion. To prevent the damage by occurring the defect, other construction or execution works, an anti-oxidation environment was forcibly made by using protective potential. Coating and protective potential are applied simultaneously, but corrosion rate or defects are not easy to observe because soil composition has many uncertainty. Also, defect of coating pipe can not be directly observed. A corrosion coupon can easily measure a corrosion rate directly. The corrosion rate was measured with 6 scenarios using corrosion coupon during about 1 year(6 scenarios are based on soil type and protective potential or not in this research. Resultingly, the corrosion coupon has not occurred in the case of protected by potential current, but corrosion has occurred in a non-protected site. The corrosion rate was measured at least in the clay, and the propensity of corrosion rate was similar in other soil(sand and loams). The local corrosion has occurred in the clay because of high water content. On the other hand, general corrosion was occurred in sand and loams. Commonly, sand is not to corrosive soil. Although, corrosion occurred in sand can be estimated by chemical component and valid with chemical analysis report.

Internal Growth Type Character and Popular Sympathy of Heroic Narrative (영웅서사의 내적 성장형 캐릭터와 대중적 공감형성 - 마블과 DC의 시네마틱 유니버스를 기반으로 -)

  • Jeon, Yeongdon
    • The Journal of the Korea Contents Association
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    • v.20 no.1
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    • pp.364-377
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    • 2020
  • Although it is never easy to create charming characters that people can relate to, well-formed characters have the power to enable the audience to not only empathize but identify with them. Thus, there is a need for us to examine the parts that make up a well-formed character. According to empathy theory, when the character in the play has a human face that is not different from me, I can feel familiarity and human empathy. Rather than perfection without loopholes, I relate to and sympathize with someone who looks similar to me, with many mistakes and some lack. This study aims to examine the attractiveness of characters in narrative dramas in terms of defects and internal growth. To do this, we tried to compare the setting, evaluation, and performance of characters based on the movie worldviews of two famous brands (DC and Marble), which can be compared directly. I looked at it. In conclusion, the work of hero character but human character setting based on internal growth not only has high evaluation and public evaluation, but also high sales, and thus direct and indirect correlation with the public favorability is significant.

Seasoning of Commercial Wood Using Solar Energy (태양에너지를 이용한 유용목재의 건조)

  • Jung, Hee-Suk;Lee, Hyoung-Woo;Lee, Nam-Ho;Lee, Sang-Bong
    • Journal of the Korean Wood Science and Technology
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    • v.16 no.4
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    • pp.10-39
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    • 1988
  • This study investigated the temperatures and relative humidities in the semi-greenhouse type solar dryer with a black rock-bed heat storage and without heat storage and outdoor temperature and relative humidity at 9 a.m. and 2 p.m.. A comparison was made of the drying rates, final moisture contents, moisture content distributions, casehardening stresses, drying defects, volumetric shrinkage of dried lumber for solar- and air-drying from the green condition of mixtures of Douglas-fir, lauan, taun, oak and sycamore 25mm- and 50 mm-thick lumber during the same period for four seasons, and heat efficiencies for solar dryer with and without the heat storage for saving of heat energy and the cost of lumber drying using the solar energy. The results from this study were summarized as follows: I. The mean weekly temperatures in the solar dryers were 3 to $6^{\circ}C$ at 9 a.m. and 9 to $13^{\circ}C$ at 2 p.m. higher than mean outdoor temperature during all the drying period. 2. The mean weekly relative humidities in the solar dryers were about 1 to 19% at 9 a.m. higher than the outdoor relative humidity. and the difference between indoor and outdoor relative humidity in the morning was greater than in the afternoon. 3. The temperatures and relative humidities in the solar dryer with and without the heat storage were nearly same. 4. The overall solar insolation during the spring months was highest and then was greater in the order of summer, atumm, and winter month. S. The initial rate of solar drying was more rapid than that of air drying. As moisture content decreased, solar drying rate became more rapid than that of air drying. The rates of solar drying with and without heat storage were nearly same. The drying rate of Douglas-fir was fastest and then faster in the order of sycamore, lauan, taun and oak. and the faster drying rate of species, the smaller differences of drying rates between thicknesses of lumber. The drying rates were fastest in the summer and slowest in the winter. The rates of solar drying during the spring were more slowly in the early stage and faster in the later stage than those during the autumn. 6. The final moisture contents were above 15% for 25mm-thick air dried and about 10% for solar dried lumber, but the mean final MCs for 50mm-thick lumber were much higher than those of thin lumber. The differences of final MC between upper and lower course of pile for solar drying were greater than those of pile for air drying. The differences of moisture content between the shell and the core of air dried lumbers were greater than those of solar dried lumber, smallest in the drying during summer and greatest in the drying during winter among seasons. 7. Casehardening stresses of 25mm- and 50mm-thick dried lumber were slight, casehardening stress of solar dried lumber was severer than that of air dried lumber and was similar between solar dried lumber with and without heat storage, Casehardening stresses of lumber dried during spring were slightest and then slighter in the order of summer, autumn, and winter. Casehardening stresses of Douglas -fir, sycamore and lauan were slight, comparing with those of taun and oak. 8. Maximum initial checks of 25mm-thick lumber occurred above and below fiber saturation point and those of 50mm-thick lumber occurred in the higher moisture content than thin lumber. As the moisture content decreased, most of checks were closed and didn't show distinct difference of the degree of checks among drying methods. The degree of checks were very slight in case of Douglas-fir and lauan, and severe in case of taun and oak. The degree of checks for 50mm-thick lumber were severer than those for 25mm-thick lumber. 9. The degree of warpage showed severe in case of oak and sycamore lumber, but no warping was found in case of Douglas-fir, lauan and taun. 10. The volumetric shrinkages of taun and oak were large and medium in case of Douglas-fir, lauan and sycamore. 11. Heat efficiencies of solar dryer with heat storage were 6.9% during spring, 7.7% during summer, 12.1% during autumn and 4.1% during winter season. Heat efficiency of solar dryer with heat storage was slightly greater than that of without heat storage. As moisture content of lumber decreased, heat efficiency decreased.

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8 Years Report of Urine Organic Acid Analysis - Comparison before and after Introduction of Neonatal Screening Test using Tandem Mass Spectrometry - (소변 유기산 분석 8년의 정리 -탠덤매스(Tandem mass spectrometry)를 이용한 신생아 선별검사 도입 전후의 비교-)

  • Ahn, Seok Min;Shin, Woo Chul;Jeong, Han Bin;Seo, Young Jun;Jeong, Hwal Rim;Yoon, Jong Hyung;Bae, Eun Ju;Lee, Hong Jin
    • Journal of The Korean Society of Inherited Metabolic disease
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    • v.18 no.1
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    • pp.1-12
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    • 2018
  • Purpose: Disorders of organic acid metabolism have various clinical manifestations and it may be life-threatening. The prognoses of affected children are dependent on early diagnosis and treatment. We report this study to find out detection rate of referred samples, clinical manifestations and age distribution after introduction of neonatal screening test using tandem mass spectrometry in Hallym University Chuncheon Sacred Heart Hospital during 8 years and 9 months. Methods: The 2,794 patients referred from Jan. 2007 to Sep. 2015 were divided into four groups according to age. We conducted organic acid analysis of urine samples of patients and analyzed clinical manifestations and distributions of age at the diagnosis. For patients with ambiguous results, reanalysis of urine organic acid after diet restriction, protein loading and restriction, has been done. Results: A total of 626 patients with 20 disorders were diagnosed. Mitochondrial disorders (482 patients) were the most common diagnosis, followed by ketolytic defects (67), 3-hydroxyisobutyric aciduria (32), EPEMA syndrome (8), 3-methylcrotonyl glycinuria (7), glutaric aciduria type II (6) and type I (4), methylmalonic aciduria (3), isovaleric aciduria (3) and medium chain acyl-CoA dehydrogenase deficiency (3). Conclusion: As neonatal screening test using tandem mass spectrometry is increasingly common and medical environment is changed, detection rate of disorders of organic acid metabolism in this study has decreased compared to previous report. Because the deterioration can be prevented by early diagnosis and treatment, many pediatricians have to pay special attention to possibility of the disorders and make an effort for early diagnosis in clinical setting.

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On the manufacturing of WPC (Wood Plastic Composites) with Heat-Catalyst Polymerization (I) - On the characteristics of composites made from monomer Methyl MethacryIate and several commercial woods in Korea (가열(加熱)·촉매중합법(觸媒重合法)에 의한 목재(木材)·고분자복합체(高分子複合體) 제조(製造)(I) - MMA에 의한 한국산(韓國産) 주요목재(主要木材)의 복합체특성(複合體特性))

  • Cho, Nam-Seok;Jo, Jae-Myeong;Ahn, Won-Yong
    • Journal of the Korean Wood Science and Technology
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    • v.2 no.3
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    • pp.3-16
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    • 1974
  • One of the disadvantages of. wood and wood products is their hydroscopicity or dimensional instability. This is responsible for the loss of green volume of lumber as seasoning degrade. Dimensional stabilization is needed to substantially reduce seasoning defects and degrades and for increasing the serviceability of wood products. Recently, considerable world-wide attention has been drawn to the so-called Wood-Plastic Composites by irradiation-and heat-catalyst-polymerization methods and many research and developmental works have been reported. Wood-Plastic Composites are the new products having the superior mechanical and physical properties and the combinated characteristics of wood and plastic. The purpose of this experiment was to obtain the basic data for the improvement of wooden materials by manufacturing WPC. The species examined were Mulpurae-Namoo (Fraxinus, rhynchophylla), Sea-Namoo (Carpinus laxiflora), Cheungcheung-Namoo (Cornus controversa), Gorosae-Namoo (Acermono), Karae-Namoo(Juglans mandshurica) and Sanbud-Namoo (Prunus sargentii), used as blocks of type A ($3{\times}3{\times}40cm$) and type B ($5{\times}5{\times}60cm$), and were conditioned to about 10~11% moisture content before impregnation in materials humidity control room. Methyl methacrylate (MMA) as monomer and benzoyl peroxide (BPO) as initiator are used. The monomer containing BPO was impregnated into wood pieces in the vacuum system. After impregnation, the treated samples were polymerized with heat-catalyst methods. The immersed weights of monomer in woods are directly proportionated to the impregnation times. Monomer impregnation properties of Cheungcheung-Namoo, Mulpurae-Namoo and Seo-Namoo are relatively good, but in Karae-Namoo, it is very difficult to impregnate the monomer MMA. Fig. 3 shows the linear relation between polymer retentions in wood and polymerization times; that is, the polymer loadings are increasing with polymerization times. Furthermore species, moisture content, specific gravity and anatomical or conductible structure of wood, bulking solvents and monomers etc have effects on both of impregnation of monomer and polymer retention. Physical properties of treated materials are shown in table 3. Increasing rates of specific gravity are ranged 3 to 24% and volume swelling 3 to 10%. ASE is 20 to 46%, AE 14 to 50% and RWA 18 to 40%. Especially, the ASE in relation to absorption of liquid water increases approximately with increase of polymer content, although the bulking effect of the polymerization of monomer may also be influential. WPCs from Mulpurae-Namoo and Cheungcheung-Namoo have high dimensional stability, while its of Karae-Namoo and Seo-Namoo are-very low. Table 4 shows the mechanical properties of WPCs from 6 species. With its specific gravity and polymer loading increase, all mechanical properties are on the increase. Increasing rate of bending strength is 10 to 40%, compression strength 25 to 70%, ;impact bending absorbed energy 4 to 74% and tensile strength 18 to 56%. Mulpurae-Namoo and Cheungcheung-Namoo with high polymer content have considerable high increasing rate of strengths. But incase of Karae-Namoo with inferior monomer impregnation it is very low. Polymer retention in cell wall is 0.32 to 0.70%. Most of the polymer is accumulated in cell lumen. Effective. of polymer retention is 58.59% for Mulpurae-Namoo, 26.27% for Seo-Namoo, 47.98% for Cheungcheung-Namoo, 25.64% for Korosae-Namoo, 9.96% for Karae-Namoo and 25.84% for Sanbud-Namoo.

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