• Title/Summary/Keyword: four point method

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Effects of Nitrogen Addition on Thermal Stability of Ta-Al Alloy Films (Ta-Al 합금박막의 열적안정성에 미치는 질소첨가 효과)

  • Jo, Won-Gi;Kim, Tae-Yeong;Gang, Nam-Seok;Kim, Ju-Han;An, Dong-Hun
    • Korean Journal of Materials Research
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    • v.7 no.10
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    • pp.877-883
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    • 1997
  • Ar 및 Ar과 $N_{2}$ 분위기하에서 rf 마그네트론 스퍼터링방법으로 Ta-AI과 Ta-AI-N합금막을 제조하였다. Ta-7.9at.% AI계열, Ta-26.7 at% AI게열과 Ta-45.4at.%AI계열에 Ar에 대한 질서유량비로 26%까지 질소를 첨가하여 Ta-AI-N박막을 증착한후, 300-$600^{\circ}C$온도 구산에서 열처리 전후의 구조 및 전기적 특성과 열적안정성을 통하여 레지스터의 적용가능성을 조사하였다. 구조 및 조성 분석은 X-선 회절과 Rutherford Backscattering Spectrometry(RBS)로 관찰하였고 열적안정성은 4단자법(four point probe method)을 이용한 저항변화를 통하여 측정하였다. 순수 Ta에 AI을 첨가하면 확장된 $\beta$($\beta$-Ta)N 합금박막에서 가장 열적안정성이 우수하게 나타났던 질소첨가 범위는 Ta $N_{hcp}$또는 TaN/ sub fcc/또는 Ta $N_{fcc}$와 비정질과의 혼합상순으로 상천이를 나타내었다. Ta-AI-N 합금박막에서 가장 열적안정성이 우수하게 나타났던 질서첨가 범위는 Ta-26.7at. % AI계열의 경우 19-36at.% $N_{2}$구간이었고, Ta-45.5at.% AI계열의 경우는 30-45at.%구간이었다. Ta-AI합금박막은 질소가 첨가되지 않아도 열처리 온도 및 시간에 따라 약 10% 이내의 비교적 작은 저항변화를 보여 열적안정성이 우수하지만 질소를 첨가하여 Ta-AI-N합금박막을 형성시킬경우, 증착된 상태에서 이미 큰 비저항을 나타내었고 열처리 동안 3%이내의 매우 작은 저항변화를 나타내었기 때문에 레지스터용 재료로써 열적안정성에 대한 잠재력이 크다.

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Improved Conductivities of SWCNT Transparent Conducting Films on PET by Spontaneous Reduction

  • Min, Hyeong-Seop;Kim, Sang-Sik;Lee, Jeon-Guk
    • Proceedings of the Materials Research Society of Korea Conference
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    • 2011.10a
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    • pp.43.2-43.2
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    • 2011
  • Single-walled carbon nanotubes (SWCNT) are transparent in the visible and show conductivity comparable to copper, and are environmentally stable. SWCNT films have high flexibility, conductivity and transparency approaching that indium tin oxide (ITO), and can be prepared inexpensively without vacuum equipment. Transparent conducting Films (TCF) of SWCNTs has the potential to replace conventional transparent conducting oxides (TCO, e.g. ITO) in a wide variety of optoelectronic devices, energy conversion and photovoltaic industry. However, the sheet resistance of SWCNT films is still higher than ITO films. A decreased in the resistivity of SWCNT-TCFs would be beneficial for such an application. We fabricated SWCNT sheet with $KAuBr_4$ on PET substrate. Arc-discharge SWCNTs were dispersed in deionized water by adding sodum dodecyl sulfate (SDS) as surfactant and sonicated, followed by the centrifugation. The dispersed SWCNT was spray-coated on PET substrate and dried on a hotplate at $100^{\circ}C$. When the spray process was terminated, the TCF was immersed into deionized water to remove the surfactant and then it was dried on hotplate. The TCF film was then treated with AuBr4-, rinsed with deionized water and dried. The surface morphology of TCF was characterized by field emission scanning electron microscopy. The sheet resistance and optical transmission properties of the TCF were measured with a four-point probe method and a UV-visible spectrometry, respectively. $HNO_3$ treated SWCNT films with Au nano-particles have the lowest 61 ${\Omega}$/< sheet resistance in the 80% transmittance. Sheet resistance was decreased due to the increase of the hole concentration at the washed SWCNT surface by p-type doping of $AuBr_4{^-}$.

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A STUDY OF SEALING ABILITY OF DENTIN BONDING AGENT AS ROOT CANAL SEALER (Dentin Bonding Agent의 근관폐쇄(根管閉鎖) 효과(效果)에 관(關)한 실험적(實驗的) 연구(硏究))

  • Min, Hyo-Kie;Min, Byung-Soon;Choi, Ho-Young;Park, Sang-Jin
    • Restorative Dentistry and Endodontics
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    • v.13 no.1
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    • pp.103-111
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    • 1988
  • The purpose of this study was to, examine the sealing ability of the denting bonding agent, when used with gutta percha cone, as a root canal sealer. Seventy two upper and lower extracted human teeth with single root were randomly selected and instrumented in a conventional method with K-file. After instrumentation and dry the canal with paper point, there were divided into three groups and twenty four teeth in each group were filled with the following material; In group I: Scotchbond in combination with gutta percha cone. In group II: AH 26 in combination with gutta percha cone. In group III: Tubli-Seal in combination with gutta percha cone. All specimens were immersed in Indian Ink, decalcified, and cleared. The depth of dye penetration into the canals were evaluated by caliper at the intervals of 1 day, 1 week, 2 weeks. The results were as follows; 1. Depth of dye penetration for all groups increased with time. 2. As to difference in mean dye penetration at time interval of 1 day and 14 days, Scotchbond group exhibited the smallest value as 0.53mm and Tubli-Seal group exhibited the largest value as 0.70mm. 3. There was the difference of dye penetration between each group, but its difference was not significant, statistically.

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Effect of Heating Time on Contents of Amino Acids and Related Compounds in the Muscle Extract of Snakehead (가열시간별 가물치육 엑스중의 아미노산 및 그 관련화합물의 변화)

  • HAN Young-Sil;KIM Kyung-Jin;PYEUN Jae-Hyeung
    • Korean Journal of Fisheries and Aquatic Sciences
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    • v.19 no.2
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    • pp.141-146
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    • 1986
  • As a fundamental study of fresh water fish on a suitable cooking method and on flavor components from the view point of food science, changes in the free amino acid composition of the muscle extracts of snakehead (Channa argus) during heating in boiling water were investigated. The muscle extract of raw fish was featured a very high content of glycine, taurine, glutamic acid and histidine, and a large amount of urine was also determined in the extract; the former four components comprised about $53\%$ of the total free amino acids. The total extractable nitrogen was greatly increased with the heating time till 120 minutes of heating, while it gradually decreased thereafter. The apparently increased components on heating of 120 minutes were taurine, glycine, alanine, hydroxyproline, and ${\beta}$-aminoisobutyric acid, etc. including urea. After hydrolysis of the extracts, some of the amino acids were increased, the content of ethanolamine, lysine, 1-methyl histidine, phenylalanine, glutamic acid and taurine, etc. were apparently increased.

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Grout Injection Control using AI Methodology (인공지능기법을 활용한 그라우트의 주입제어)

  • Lee Chung-In;Jeong Yun-Young
    • Tunnel and Underground Space
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    • v.14 no.6 s.53
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    • pp.399-410
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    • 2004
  • The utilization of AS(Artificial Intelligence) and Database could be considered as an useful access for the application of underground information from the point of a geotechnical methodology. Its detailed usage has been recently studied in many fields of geo-sciences. In this paper, the target of usage is on controlling the injection of grout which more scientific access is needed in the grouting that has been used a major method in many engineering application. As the proposals for this problem it is suggested the methodology consisting of a fuzzy-neural hybrid system and a database. The database was firstly constructed for parameters dynamically varied according to the conditions of rock mass during the injection of grout. And then the conceptional model for the fuzzy-neural hybrid system was investigated fer optimally finding the controlling range of the grout valve. The investigated model applied to four cases, and it is found that the controlling range of the grout valve was reasonably deduced corresponding to the mechanical phenomena occurred by the injection of grout. Consequently, the algorithm organizing the fuzzy-neural hybrid system and the database as a system can be considered as a tool for controlling the injection condition of grout.

Hardware Design of High Performance Arithmetic Unit with Processing of Complex Data for Multimedia Processor (복소수 데이터 처리가 가능한 멀티미디어 프로세서용 고성능 연산회로의 하드웨어 설계)

  • Choi, Byeong-yoon
    • Journal of the Korea Institute of Information and Communication Engineering
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    • v.20 no.1
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    • pp.123-130
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    • 2016
  • In this paper, a high-performance arithmetic unit which can efficiently accelerate a number of algorithms for multimedia application was designed. The 3-stage pipelined arithmetic unit can execute 38 operations for complex and fixed-point data by using efficient configuration for four 16-bit by 16-bit multipliers, new sign extension method for carry-save data, and correction constant scheme to eliminate sign-extension in compression operation of multiple partial multiplication results. The arithmetic unit has about 300-MHz operating frequency and about 37,000 gates on 45nm CMOS technology and its estimated performance is 300 MCOPS(Million Complex Operations Per Second). Because the arithmetic unit has high processing rate and supports a number of operations dedicated to various applications, it can be efficiently applicable to multimedia processors.

Study on Diagnosis by Visual Inspection of Local Regions in Nei-Ching ("황제내경"의 국소부위 망형태(望形態)에 대한 연구)

  • Seo, Jae-Ho;Kim, Jeong-Kyun;Kim, Hyun-Ho;Park, Jin-Sung;Park, Young-Bae;Park, Young-Jae
    • The Journal of the Society of Korean Medicine Diagnostics
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    • v.15 no.3
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    • pp.235-244
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    • 2011
  • Objectives: There are four types of diagnostic methods in Oriental medicine, and visual inspection is the first method among them. This study was written in order to complement further understanding on visual inspection. Methods: The authors reviewed a word related with visual inspection in Nei-Ching. The authors researched static words such as bigger/smaller, longer/shorter, slower/faster, curved/straight, one-sided/fair, and groove/uplift, and active words such as extension and contraction, shake, tremor, slow, fast, walk, run, standing, lying, and sitting related with visual inspection in Nei-Ching. Results: The static words linked with visual inspection are related with skin, muscles, fat, and especially the liver, stomach, and large intestine. The active words linked with visual inspection are related with movement of muscles, fat, and bone. Conclusion: In this study, the authors provided further understanding on visual inspection in Nei-Ching. However, there was no clear reference point about appearances and movements.

A Study on Pattern Development of Men's Slim-fit Dress Shirt - Focus on the 25-35 aged men - (슬림핏 드레스 셔츠 패턴 개발에 관한 연구 - 25~35세 영 어덜트 층 남성을 중심으로 -)

  • Kim, Dong-Hyun;Jang, Jeong-Ah
    • The Korean Fashion and Textile Research Journal
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    • v.15 no.6
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    • pp.950-962
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    • 2013
  • The purpose of this study was to develop the slim-fit dress shirt pattern. Among the published educational patterns, there were four patterns based on similar design and silhouette with slim-fit dress shirts. Then, the drafting method of those patternsBB were compared and analyzed. The subjects for wearing evaluation were three 20 to 39 aged average-sized men. After the wearing evaluation(5 Likert point scale), N pattern had been chosen as the final comparison pattern because it received the highest points. The slim-fit shirt pattern was developed based on the result of wearing evaluation. The foundation design were as following: shirt length (Stature/2-12), back length (Stature/4), armhole depth (Chest/4+1), width (Chest/4+3), Interscye; Back (Chest/6+5), Interscye; Front (Chest/6+4), width of the nape of neck (Neck/6+1=◎), height of the nape of neck (◎/3), of the front neck (◎-0.5), depth of the front neck(◎+1.5). After the wearing evaluation about researched pattern and N pattern, researched patternsBB scale points were bigger than N pattern and there were slight differences. The scale points for N patternsBB movement evaluation showed highest points on all contents. Therefore, the researched pattern is suitable for the original form of slim-fit dress shirt. The new dress shirt pattern reflected the slim-fit trend in the research expected to help educational environment and industrial site.

A Study on the Use of General Social Welfare Facilities for the Planning of Integrated Care Center - Focused on four social welfare facilities in Southern Gyeonggi-do (통합돌봄센터 계획을 위한 고령인구의 종합사회복지관 이용실태 연구 - 경기도 남부 4개 사회복지관을 대상으로)

  • Han, Eunbee;Zhang, Jinxiang;Kwon, Soonjung
    • Journal of The Korea Institute of Healthcare Architecture
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    • v.26 no.2
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    • pp.71-79
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    • 2020
  • Purpose: The purpose of this study is to derive basic data for desirable location and functions of the integrated care center. Methods: Survey, Questionaire and statistical analysis are the main research method of this study. In order to collect data related to utilization pattern and favorite functions of the senior people, researchers have visited 4 social welfare facilities located in Southern Gyeonggi Province. 403 questionaires have been gathered from 4 facilities and they have been analyzed by using Excel Program of MS. Results: First, compared to other services, healthcare services have been preferred by many older people in Social welfare Facilities. This means that integrated care centers providing healthcare services for older people rather than services for children or disabilities is desirable. Second, Integrated Care Centers had better be established within the walk distance of elderly people. If it is not easy, the introduction of shuttle bus for older people is desirable. Especially, in case of large Care Center. Implications: This study shows that small facility with community care rather than big facility is desirable for small community in the point of friendliness, convenience, economy, etc.. However it is necessary to combine welfare service and healthcare service even in small centers.

Computational Analysis of Tumor Angiogenesis Patterns Using a Growing Brain Tumor Model

  • Shim, Eun-Bo;Kwon, Young-Keun;Ko, Hyung-Jong
    • International Journal of Vascular Biomedical Engineering
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    • v.2 no.1
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    • pp.17-24
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    • 2004
  • Tumor angiogenesis was simulated using a two-dimensional computational model. The equation that governed angiogenesis comprised a tumor angiogenesis factor (TAF) conservation equation in time and space, which was solved numerically using the Galerkin finite element method. The time derivative in the equation was approximated by a forward Euler scheme. A stochastic process model was used to simulate vessel formation and vessel elongation towards a paracrine site, i.e., tumor-secreted basic fibroblast growth factor (bFGF). In this study, we assumed a two-dimensional model that represented a thin (1.0 mm) slice of the tumor. The growth of the tumor over time was modeled according to the dynamic value of bFGF secreted within the tumor. The data used for the model were based on a previously reported model of a brain tumor in which four distinct stages (namely multicellular spherical, first detectable lesion, diagnosis, and death of the virtual patient) were modeled. In our study, computation was not continued beyond the 'diagnosis' time point to avoid the computational complexity of analyzing numerous vascular branches. The numerical solutions revealed that no bFGF remained within the region in which vessels developed, owing to the uptake of bFGF by endothelial cells. Consequently, a sharp, declining gradient of bFGF existed near the surface of the tumor. The vascular architecture developed numerous branches close to the tumor surface (the brush-border effect). Asymmetrical tumor growth was associated with a greater degree of branching at the tumor surface.

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