• 제목/요약/키워드: Sigma S

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Sulfuric Acid Treatment of Sapphire Substrates for Growth of High-Quality Epilayers

  • Park, Ji-Won;No, Young-Soo;Jung, Yeon-Sik;Yoon, Seok-Jin;Kim, Tae-Whan;Park, Won-Kook
    • Journal of the Korean Ceramic Society
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    • v.41 no.7
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    • pp.493-496
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    • 2004
  • The chemical etching of sapphire substrates was peformed to produce smooth surfaces on an atomic scale. The sapphire sur-face etched by using a $H_2$S $O_4$ solution showed a pit-free morphology and was yen smooth as much as $\sigma$$_{rms}$=0.13 nm, that etched by using a mixture of $H_2$S $O_4$ and $H_3$P $O_4$ contained large pits with $\sigma$$_{rms}$=0.34 nm. The $\sigma$$_{rms}$’s and the number of the pits increased with increasing etching temperature. The sapphire etched by using $H_2$S $O_4$ at 32$0^{\circ}C$ had the best surface. These results provide important information on the effects of etching treatment on the structural properties of sapphire for the growth of high-quality epilayers.ayers.

Mo Interpretation for the Substituent Effect of Stilbenes (스틸벤의 치환기 효과에 대한 분자궤도함수론적 해석)

  • Lim Sung-Mi;Park Byung-Kak;Lee Gab-Yong
    • Journal of the Korean Chemical Society
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    • v.36 no.1
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    • pp.38-43
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    • 1992
  • The Hammett's substituent constants were interpreted for substituted stilbenes by HMO method. The appropriate quantum chemical indices are chosen as independent contribution of the inductive and the resonance effects for substituent constants. It has been found that theoretical values, ${\sigma}_p{^{th}}$, defined as sum of the net charge, self atom polarizability and difference in HOMO energy between substituted- and unsubstituted-stilbenes, correlated with experimental Hammett's substituent constants. The dipole moments were found to be correlated with differences in ${\sigma}_p{^{th}}$ between two substituents for disubstituted stilbenes. It has been also found that transition optical spectra, ${\lambda}_{max}$ of the substituted stilbenes depend on difference between the HOMO and the LUMO energy as expected.

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The Influence of Learner's Individual Characteristics on Using Six Sigma and the Structural Role of an Organization's Learning Culture and its Support (학습자 개인특성이 6시그마 활용에 미치는 영향과 조직의 학습문화 및 조직지원의 구조적 역할)

  • Choi, Seung-Eun;Kim, Min-Sun;Kang, So-Ra
    • Journal of Information Technology Applications and Management
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    • v.17 no.2
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    • pp.19-45
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    • 2010
  • This research has analyzed the differentiated influence of organizational variables(an organization's learning culture and organizational support networks) and personal variables(the individual's motivation to learn and self-efficacy) on the process of gaining and using of knowledge. These two variables have been regarded as the major variables for the successful learning of 6Sigma, according to Social Cognitive Theory. In addition, this research has proven the role structure of the abovementioned two variables through a suitable methodology(Hierarchical Linear Model). In regard to this methodology, the different hierarchical level of the personal variable and organizational variable was especially focused on, and the effect of interaction between the high level and the low level was considered in detail. Considering the current situation, in that the importance of organizational factor and personal factor has been emphasized but the accurate role of each variable has not been verified, the research model is thought to help to establish an effective strategy to implement 6 Sigma.

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Implementation of 24bit Sigma-delta D/A Converter for an Audio (오디오용 24bit 시그마-델타 D/A 컨버터 구현)

  • Heo, Jeong-Hwa;Park, Sang-Bong
    • The Journal of the Institute of Internet, Broadcasting and Communication
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    • v.8 no.4
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    • pp.53-58
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    • 2008
  • This paper designs sigma-delta D/A Converter with a high resolution and low power consumption. It reorganizes the input data along LJ, RJ, I2S mode and bit mode to the output data of A/D converter. The D/A converter decodes the original analog signal through HBF, Hold and 5th CIFB(Cascaded Integrators with distributed Feedback as well as distributed input coupling) sigma-delta modulation blocks. It uses repeatedly the addition operation in instead of the multiply operation for the chip area and the performance. Also, the half band filters of similar architecture composed the one block and it used the sample-hold block instead of the sinc filter. We supposed simple D/A Converter decreased in area. The filters of the block analyzed using the matlab tool. The top block designed using the top-down method by verilog language. The designed block is fabricated using Samsung 0.35um CMOS standard cell library. The chip area is 1500*1500um.

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Incremental Delta-Sigma Analog to Digital Converter for Sensor (센서용 Incremental 델타-시그마 아날로그 디지털 변환기 설계)

  • Jeong, Jinyoung;Choi, Danbi;Roh, Jeongjin
    • Journal of the Institute of Electronics and Information Engineers
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    • v.49 no.10
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    • pp.148-158
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    • 2012
  • This paper presents the design of the incremental delta-sigma ADC. The proposed circuit consists of pre-amplifier, S & H circuit, MUX, delta-sigma modulator, and decimation filter. Third-order discrete-time delta-sigma modulator with 1-bit quantization were fabricated by a $0.18{\mu}m$ CMOS technology. The designed circuit show that the modulator achieves 87.8 dB signal-to-noise and distortion ratio (SNDR) over a 5 kHz signal bandwidth and differential nonlinearity (DNL) of ${\pm}0.25$ LSB, integral nonlinearity (INL) of ${\pm}0.2$ LSB. Power consumption of delta-sigma modulator is $941.6{\mu}W$. It was decided that N cycles are 200 clock for 16-bits output.

Strategic Business Process Based on Business Intelligence by Connected with BPM & 6 Sigma (BPM과 6 Sigma 연계에 의한 BI기반의 전략적 비즈니스 프로세스)

  • Park, Sang-Min;Nam, Ho-Ki;Shin, Seung-Ho;Kim, Qui-Nam
    • Convergence Security Journal
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    • v.7 no.2
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    • pp.27-37
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    • 2007
  • Companies have to take agility against change of environment and build up the capacity of new value creation in today's management environment. Until now, there are so many management method for efficiency of management, rationality of management and IT (information technology) supported this method by integration of enterprise task and process automation. but company's competitiveness through the efficiency of management realized the limitations recently. so companies needs the new management method to raise core value of enterprise. This study applies strategy intelligence which is some part of Business Intelligence. We can identify the core value driver by using this method. and the core value driver is connected the KPI (key performance indicator) of processes in BPM (Business Process Management). This help the management of process focused on value driver. and some part of activity driver that effect the process performance can be use the Six Sigma method to strategic business process. This study first introduces the concept of Business Intelligence, Business Process Management and Six Sigma. and then efficient connection plan for value based strategic business process is introduces.

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A Study on the Recognition Difference of the Success Factors of Six Sigma on the Line of Size (규모에 따른 6시그마 성공요인의 안석 차이연구: 공급자 관점에서 바라본 마케팅 성과)

  • Lee, Seung-Hee;Jo, Young-Jun;Kim, Young-Soo
    • Journal of Digital Convergence
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    • v.8 no.2
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    • pp.177-188
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    • 2010
  • This paper is aimed to examine an empirical analysis of the differences among success factors that contribute to high performance of the organizations that adopted Six Sigma according to company size. Furthermore, the research focused on empirically analyzing whether these factors affect marketing performance or not, from the provider's point of view. For this purpose, a survey was conducted among conglomerates, and small and mid-sized companies which are located in the Gumi Industrial Complex that implemented Six Sigma. The following are facts that were found by empirically analyzing the results. Therefore, it is empirically proven that there are quality performance differences according to company size. marketing performance differences from the provider's point of view. the theoretical proposed model, identified the operational definitions and 9 hypotheses were established, there were executed the survey of 250 employees in companies implementing six sigma.

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Formation and Characteristics of the Fluorocarbonated SiOF Film by $O_2$/FTES-Helicon Plasma CVD Method

  • Kyoung-Suk Oh;Min-Sung Kang;Chi-Kyu Choi;Seok-Min Yun
    • Proceedings of the Korean Vacuum Society Conference
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    • 1998.02a
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    • pp.77-77
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    • 1998
  • Present silicon dioxide (SiOz) 떠m as intennetal dielectridIMD) layers will result in high parasitic c capacitance and crosstalk interference in 비gh density devices. Low dielectric materials such as f f1uorina뼈 silicon oxide(SiOF) and f1uoropolymer IMD layers have been tried to s이ve this problem. I In the SiOF ftlm, as fluorine concentration increases the dielectric constant of t뼈 film decreases but i it becomes unstable and wa않r absorptivity increases. The dielectric constant above 3.0 is obtain어 i in these ftlms. Fluoropolymers such as polyte$\sigma$따luoroethylene(PTFE) are known as low dielectric c constant (>2.0) materials. However, their $\alpha$)Or thermal stability and low adhesive fa$\pi$e have h hindered 야1리ru뚱 as IMD ma따"ials. 1 The concept of a plasma processing a찌Jaratus with 비gh density plasma at low pressure has r received much attention for deposition because films made in these plasma reactors have many a advantages such as go여 film quality and gap filling profile. High ion flux with low ion energy in m the high density plasma make the low contamination and go어 $\sigma$'Oss피lked ftlm. Especially the h helicon plasma reactor have attractive features for ftlm deposition 야~au똥 of i앙 high density plasma p production compared with other conventional type plasma soun:es. I In this pa야Jr, we present the results on the low dielectric constant fluorocarbonated-SiOF film d밑JOsited on p-Si(loo) 5 inch silicon substrates with 00% of 0dFTES gas mixture and 20% of Ar g gas in a helicon plasma reactor. High density 띠asma is generated in the conventional helicon p plasma soun:e with Nagoya type ill antenna, 5-15 MHz and 1 kW RF power, 700 Gauss of m magnetic field, and 1.5 mTorr of pressure. The electron density and temperature of the 0dFTES d discharge are measUI벼 by Langmuir probe. The relative density of radicals are measured by optic허 e emission spe따'Oscopy(OES). Chemical bonding structure 3I피 atomic concentration 따'C characterized u using fourier transform infrared(FTIR) s야3띠"Oscopy and X -ray photonelectron spl:’따'Oscopy (XPS). D Dielectric constant is measured using a metal insulator semiconductor (MIS;AVO.4 $\mu$ m thick f fIlmlp-SD s$\sigma$ucture. A chemical stoichiome$\sigma$y of 야Ie fluorocarbina$textsc{k}$영-SiOF film 따~si야영 at room temperature, which t the flow rate of Oz and FTES gas is Isccm and 6sccm, res야~tvely, is form려 야Ie SiouFo.36Co.14. A d dielec$\sigma$ic constant of this fIlm is 2.8, but the s$\alpha$'!Cimen at annealed 5OOt: is obtain려 3.24, and the s stepcoverage in the 0.4 $\mu$ m and 0.5 $\mu$ m pattern 킹'C above 92% and 91% without void, res야~tively. res야~tively.

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Antifungal activity of N-[1-(benzotriazol-1-yl)aryl]arylamine derivatives and quntitative structure-activity relationships(QSAR) (N-[1-(benzotriazol-1-yl)aryl]arylamine 유도체의 항균성과 정량적 구조활성 관계(QSAR))

  • Sung, Nack-Do;Kim, Kyoung-Hoon;Choi, Woo-Young;Kim, Hong-Ki
    • Applied Biological Chemistry
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    • v.35 no.1
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    • pp.14-22
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    • 1992
  • A series of new N-[1-(benzotriazol-1-yl)aryl]arylamine derivatives were synthesized and their antifungal activities $(pI_{50})$ in vitro against Pyricularia oryzae, Fusarium oxysporum f. sp. sesami, Valsa ceratosperma and Botrytis cinerea were dertermined by the agar medium dilution method. From the results of the quantitative structure-activity relationships $(QSAR_S)$ analysis, $hydrophobicity({\pi})$, $electronic({\Sigma\sigma})$ and molar $refractivity({\Sigma}M_R)$ parameter of X & Y-substituents on the phenyl group were also shown to be important factor in determining the variation in the antifungal activity. 4-Bromo group substituents (1d & 2b) were the most effective compounds and the $half-life(T_{1/2})$ on the hydrolysis of X(1) at netural pH was about 1.5 day. Molecular orbital(MO) functions of substrate compound, linear free energy relationships$(LFER_S)$ on the antifungal reactivity arid the results of molecular design were also discussed.

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Effects of Anisotropic Consolidation on the Postcyclic Undrained Shear Strength of an Overconsolidated Clay (이방압밀이 반복하중을 받은 과압밀점토의 비배수전단강도에 미치는 영향)

  • Gang, Byeong-Hui;Yun, Hyeong-Seok;Park, Dong-Jin
    • Geotechnical Engineering
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    • v.14 no.1
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    • pp.37-48
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    • 1998
  • The effects of consolidation stress history including consolidation stress ratio, OCR and cyclic loading with drainage on the undrained shear strength of cohesive soil were investig toted. The ratio$(S_u/\sigma'_{vc})ckou/(S_U/\sigma_{vc})cuv$ was observed to increase with increasing OCR. The equation (1) in this paper by Mayne(1980) for the undrained shear strength of the overconsolidated clay and the equation (4) by Yasuhara(1994), for the postcyclic shear strength were found to be relatively well applicable in the case of Kofonsolidated. It was also suggested that the value of the critical state pore pressure parameter As in these two equations for the in situ shear strength of lightly overconsolidated clay(OCR< 3) be obtained by the standard consolidating test.

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