• Title/Summary/Keyword: U.A.V

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Photoelastic Stress Analysis of Fixed Partial Dentures (가공의치(架工義齒)에 작용(作用)하는 Stress에 관(關)한 광탄성학적(光彈性學的) 분석(分析))

  • Cho, Won-Haeng
    • The Journal of Korean Academy of Prosthodontics
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    • v.18 no.1
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    • pp.15-35
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    • 1980
  • The purpose of this study was to investigate stresses in the various components of fixed partial dentures restoring the posterior teeth of the lower jaw, and to measure quantitatively the effects of certain modifications in structural design on the stresses in the restorations using two-dimensional photoelasticity. Two-dimensional photoelastic methods were used in this study. Several models of fixed partial dentures were constructed. Shoulder less margins and anatomic occlusal reduction were incorporated in Model 1. Rounded shoulders and flat occlusal reduction were incorporated in Model 2, while Model 3 was a cantilever fixed partial denture. Other similar fixed partial dentures were constructed with V and U notches deliverately included in the region of the fixed joints for comparative reasons. The birefringent materials used in this study were PSM-1 and PSM-5 in standard sheets. PSM-1 was used for constructing the substructure, and PSM-5 was used in making the components of the fixed partial dentures. The two materials were used in the construction of composite photoelastic models. Improved artificial stone was used to represent dental cement in luting the composite photoelastic models. Static loading procedures were used at preplanned sites to represent occlusal loads in the mouth. 35 mm color and B/W film were used to record isochromatics in accordance with photoelastic procedures. Data reduction was performed using the grid method, which helped in, the mathematical integration procedure (Shear difference method) to separate the principal stresses. The results were as follows. 1. Fixed partial dentures do not function in bending as a symmetrical beam. Alternate areas of tension and compression were demonstrated when multiple contact loading was used. 2. The weakest part in posterior fixed partial dentures is the fixed joint. 3. (1) Models I and modified Model I were loaded on the pontic using a 50 pound vertical static load. The shear stress near the posterior fixed joint in Model 1 (U notches) was+129.4 p.s.i., and at the same fixed joint in modified Model 1 (V notches) was+239.4 p.s.i. The concentration of stress in fixed joint was reduced by 50% when U notches replaced the V notches. (2) Modified Model 2 was loaded using a multiple contact loader at a total load of 125 pounds. The difference between the principal stresses (${\sigma}_1-{\sigma}_2$), shear stress, at the V notches was+600 p.s.i., and at the U notches was+3l7 p.s.i. The shear stress was reduced by 50% when U notches replaced the V notches. V-grooves at the fixed joints should be avoided, and should be replaced by regular shaped U-grooves. 4. Cantilever fixed partial dentures had much higher stresses at the fixed joint than fixed partial dentures that were attached at both ends.

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Cross-generational Change of /o/ and /u/ in Seoul Korean II: Spectral Interactions in Normalized Vowel Space

  • Kang, Hyunsook;Han, Jeong-Im
    • Phonetics and Speech Sciences
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    • v.5 no.2
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    • pp.33-41
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    • 2013
  • This is a follow-up study on Han and Kang (2013) which argued that the Euclidean distances between /o/ and /u/ in Seoul Korean decreased in the first syllable position as speakers were among younger female speakers but not for male speakers, whereas in the second syllable position both gender groups showed a cross-generational decreasing effect of the Euclidean distance between /o/ and /u/. This study normalized the same data in Han and Kang (2013) which measured 12 speakers (six males and six females) for each Age group and investigated the spectral changes vowels /o/ and /u/ between age and gender, using the log-mean normalized statistical results. This study also examined overlap fraction values generated in SOAM 2D ($F1{\times}F2$) (cf. Wassink, 2006), which may also indicate the proximity of two vowels in question. The results showed that /o/ and /u/ vowels were making closer with /o/ raising for female speakers in $V_1$ and $V_2$ positions but only in the $V_2$ position for male speakers. That is, females led the upward movement of peripheral /o/ vowel, just like the raising of 'e' and 'o' in New York City (Labov, 1991). The results also showed that younger speakers used a rather narrow vowel space for the vowels. This also contributed to the proximity of the vowels /o/ and /u/, resulting in rather large overlap fraction values for younger speakers between these two vowels.

A Sensitive Detection of Actinide Species in Solutions Using a Capillary Cell (모세관 셀을 이용한 수용액 내 악티나이드 화학종의 고감도 검출)

  • Cho, Hye-Ryun;Park, Kyuong-Kyun;Jung, Euo-Chang;Song, Kyu-Seok
    • Journal of Nuclear Fuel Cycle and Waste Technology(JNFCWT)
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    • v.7 no.2
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    • pp.109-114
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    • 2009
  • Absorption spectra for a quantitative analysis of actinide elements such as U(VI) and Pu(V) were measured by using a liquid waveguide capillary cell (LWCC) which has an optical path length of 1.0 meter. In order to investigate radioactive elements, a LWCC is installed in a glove box and is coupled to a spectrophotometer with optical fibers. Limits of detection (LOD) for the system were determined as 0.74 and 0.35 M with molar absorption coefficients of 8.14${\pm}$0.07 (414 nm) and 17.00${\pm}$0.16 (569 nm) $M^{-1}cm^{-1}$ for U(VI) and Pu(V) ions, respectively. The measured LOD values are about 30 times more sensitive when compared to those achievable by using a conventional quartz cell with an optical path length of 1.0 cm. As an application with an enhanced sensitivity, a quantitative analysis for micromolar concentrations of Pu(V) has been performed to decrease the uncertainty in the formation constant of the Pu(VI)-OH complex.

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ON CHARACTERIZATIONS OF PRÜFER v-MULTIPLICATION DOMAINS

  • Chang, Gyu Whan
    • Korean Journal of Mathematics
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    • v.18 no.4
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    • pp.335-342
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    • 2010
  • Let D be an integral domain with quotient field K,$\mathcal{I}(D)$ be the set of nonzero ideals of D, and $w$ be the star-operation on D defined by $I_w=\{x{\in}K{\mid}xJ{\subseteq}I$ for some $J{\in}\mathcal{I}(D)$ such that J is finitely generated and $J^{-1}=D\}$. The D is called a Pr$\ddot{u}$fer $v$-multiplication domain if $(II^{-1})_w=D$ for all nonzero finitely generated ideals I of D. In this paper, we show that D is a Pr$\ddot{u}$fer $v$-multiplication domain if and only if $(A{\cap}(B+C))_w=((A{\cap}B)+(A{\cap}C))_w$ for all $A,B,C{\in}\mathcal{I}(D)$, if and only if $(A(B{\cap}C))_w=(AB{\cap}AC)_w$ for all $A,B,C{\in}\mathcal{I}(D)$, if and only if $((A+B)(A{\cap}B))_w=(AB)_w$ for all $A,B{\in}\mathcal{I}(D)$, if and only if $((A+B):C)_w=((A:C)+(B:C))_w$ for all $A,B,C{\in}\mathcal{I}(D)$ with C finitely generated, if and only if $((a:b)+(b:a))_w=D$ for all nonzero $a,b{\in}D$, if and only if $(A:(B{\cap}C))_w=((A:B)+(A:C))_w$ for all $A,B,C{\in}\mathcal{I}(D)$ with B, C finitely generated.

A Study on the 0.5$\mu\textrm{m}$ Dual Gate High Voltage Process for Multi Operation Applications (Multi Operation을 위한 0.5$\mu\textrm{m}$Dual Gate 고전압 공정에 관한 연구)

  • 송한정;김진수;곽계달
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 2000.11a
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    • pp.463-466
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    • 2000
  • According to the development of the semiconductor micro device technology, IC chip trends the high integrated, low power tendency. Nowadays, it can be showed the tendency of single chip in system level. But in the system level, IC operates by multi power supply voltages. So, semiconductor process is necessary for these multi power operation. Therefore, in this paper, dual gate high voltage device that operate by multi power supply of 5V and 20V fabricated in the 0.5${\mu}{\textrm}{m}$ CMOS process technology and its electrical characteristics were analyzed. The result showed that the characteristics of the 5V device almost met with the SPICE simulation, the SPICE parameters are the same as the single 5V device process. And the characteristics of 20V device showed that gate length 3um device was available without degradation. Its current was 520uA/um, 350uA/um for NMOS, PMOS and the breakdown voltages were 25V, 28V.

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Klassifikation deutscher Satze nach der Verbstellung (동사 위치에 따른 문장 분류)

  • KIM Youn-Chan
    • Koreanishche Zeitschrift fur Deutsche Sprachwissenschaft
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    • v.2
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    • pp.129-147
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    • 2000
  • In dieser vorliegenden Arbeit handelt es sich urn die Verbstellung deutscher $S\"{a}tze$. Deutsche Satze lassen sich in 3 Klassen (V1-, V2-, und VE-Struktur nach der Verbstellung einteilen. Im Rahmen der GB-Theorie gibt es jedoch nur einen Platz, an dem eine Konjunktion auftreten kann. Deshalb muss man $f\"{u}r$ zusammengesetzte Konjunktionen einen Analysenbaum aufstellen, auf dem ihre einzelnen Bestandteile die C-Position einnehmen: Diese Struktur zeigt eine gute Grundlage, auf der man den 'als-ware'-Satz $f\"{u}r$ die V1-Struktur halten kann. Einerseits leitet die subordinierende Konjunktion '$au{\ss}er$' auch eine V2-Struktur, weil wir nur mit dem minimalen CP zur Verbstellung zu rechnen brauchen; Es gibt keinen Ausweg, $au{\ss}er$ wir bitten ihn um Hilfe. Andererseits ist der Satz in der V1-Form, den die koordinierende Konjunktion 'noch' mit einen anderen Satz verbindet; Sie brauchte weder Hilfe, noch bat sie um Rat. Das beruht auf der Tatsache, dass die koordinierende Konjunktion 'noch' nicht im $CP_1$-Bereich liegt.

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EXISTENCE OF A POSITIVE SOLUTION FOR THE SYSTEM OF THE NONLINEAR BIHARMONIC EQUATIONS

  • Choi, Q-Heung;Jung, Tacksun
    • Korean Journal of Mathematics
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    • v.15 no.1
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    • pp.51-57
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    • 2007
  • We prove the existence of a positive solution for the system of the following nonlinear biharmonic equations with Dirichlet boundary condition $$\{{\Delta}^2u+c{\Delta}u+av^+=s_1{\phi}_1+{\epsilon}_1h_1(x)\;in\;{\Omega},\\{\Delta}^2v+c{\Delta}v+bu^+=s_2{\phi}_1+{\epsilon}_2h_2(x)\;in\;{\Omega},$$ where $u^+= max\{u,0\}$, $c{\in}R$, $s{\in}R$, ${\Delta}^2$ denotes the biharmonic operator and ${\phi}_1$ is the positive eigenfunction of the eigenvalue problem $-{\Delta}$ with Dirichlet boundary condition. Here ${\epsilon}_1$, ${\epsilon}_2$ are small numbers and $h_1(x)$, $h_2(x)$ are bounded.

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Evaluating of Traffic Flow Distributed Control Strategy on u-TSN(ubiquitous-Transportation Sensor Network) (V2I 통신을 이용한 교통류 분산제어 전략 수립 및 평가)

  • Kim, Won-Kyu;Lee, Min-Hee;Kang, Kyung-Won;Kim, Byung-Jong;Kang, Yeon-Su;Oh, Cheol;Kim, Song-Ju
    • Journal of The Institute of Information and Telecommunication Facilities Engineering
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    • v.8 no.3
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    • pp.122-131
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    • 2009
  • Ubiquitous-Transportation sensor network is able to realize a vehicle ad-hoc network. Since there are some problems in an existing ITS system, the new technology and traffic information strategies are requirements in this advanced system, u-TSN. The purposes of this paper is to introduce the components on u-TSN system, establish new traffic strategies for this system, and then evaluate these strategies by making a comparative study of ITS and using micro traffic simulator, AIMSUN. The strategy evaluated by AIMSUN is position-based multicast strategy which provides traffic information to vehicles using V2I (vehicle to Infrastructure) communication. This paper focuses on the providing real-time route guidance information when congestion is occurred by the incidents. This study estimates total travel time on each route by API modules. Result from simulation experiments suggests that position-based multicast strategy can achieve more optimal network performance and increased driver satisfaction since the total accumulated travel times of both the major road and the total system on position-based multicast strategy are less than those on VMS.

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Study on Springback Characteristic of Cold Rolled Steel Sheet (자동차용 냉연 강판의 형상 동결성 연구)

  • 한수식;박기철;남재복
    • Proceedings of the Korean Society for Technology of Plasticity Conference
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    • 1998.06a
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    • pp.17-24
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    • 1998
  • This paper deals with the springback characteristics of cold rolled sheet steel through the use of the V-bending process and U-bending one. The influence of material properties on the springback of forming processes was investigated. In the V-bending process there was an optimum bend radius for each combination of parameters which produced minimal springback. In the U-bending process the blank holder force can control the degree of springback. A high blank holding force resulted in a uniform strain distribution and reduced the level of springback.