• Title/Summary/Keyword: weak dependence

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A Study on Environmental Design Treatments of Subway Stations in Terms of Visual Cues for Place Indication - Focused on the Cases of Seoul, Tokyo and Taipei - (장소지시단서로서의 지하철역 환경디자인 기법에 관한 연구 -서울, 동경, 타이페이 사례를 중심으로-)

  • Park, Hey-Kyung
    • Archives of design research
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    • v.19 no.5 s.67
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    • pp.351-362
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    • 2006
  • Currently, finding one's way in the underground spaces associated with subway stations in large cities is becoming a serious problem, and an environment that facilitates wayfinding is becoming more important. This study investigated interior treatments that function as visual cues in the subway stations of Seoul, Tokyo, and Taipei in order to develop design guidelines that would improve the place-cognition environment. A theoretical study has shown that there are three categories of visual cue for place cognition: marked trails, regional differentiation, and landmarks. The case study showed that marked trails involve treatments like vertical markers, confrontational positioning, and subway color codes. Regional differentiation involves patterns on the floors and walls, and accent colors on the walls and columns. Landmarks include treatments such as super graphics, symbolic features, artistic decoration and special lights. In the cases of Seoul, marked trails and regional differentiation were predominant. In addition, the Olympic symbol 'Hodori' and the ancient Korean character "Hunminjungeum" were used as landmarks. In the cases of Tokyo, regional differentiation predominated over marked trails because of the complexity of the spatial structure and subway line connection system. In the cases of Taipei, simple, unified images predominated, and there was minimal dependence on marked trails and landmarks. The need for regional differentiation was weak, because the stations studied have open structures that guarantee an open field of view. The results of this research could be used as design guidelines, after further experimental verification, that would help to improve the public environment in terms of wayfinding.

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An Analysis and Industrial Classification of Modeling and Simulation Service Industry (모델링 및 시뮬레이션 서비스 산업 분류 및 현황 분석)

  • Kim, Myungil;Jung, Jaeyun;Han, Yuri;Park, Sung-Uk;Kim, Jaesung
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.18 no.3
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    • pp.185-198
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    • 2017
  • Since the year 2000, the growth rate of domestic manufacturing has declined and the sales and employment have decreased. Major developed countries have established a variety of strategies to strengthen their manufacturing competitiveness, and promote manufacturing innovation through the convergence of technology and ICT. The key to manufacturing innovation is to reduce the time and cost for developing new products using modeling and simulation (M&S) technology in the product design stage. M&S industries, which belong to the top sector of the industry value chain, have a huge ripple effect across other industries. On the other hand, the competitiveness of the domestic M&S industry is weak compared to developed countries and even the definition and classification of domestic M&S companies have not been made. In this paper, by analyzing the Korea Standard Industry Classification (KSIC), five fine industry classifications included in M&S service companies were derived. In addition, the 307 M&S service companies were derived in accordance with the selection procedure of 3 steps from the 11,822 related companies. To analyze the capabilities of domestic M&S service companies, the current status of the selected M&S service companies was investigated. Considering the Korean economy's high dependence on the manufacturing industry, strengthening the competitiveness of manufacturing industry is required by enhancing the capacities and building an ecosystem in domestic M&S services for future sustainable economic growth.

Thermal Stable Ni-silicide Utilizing Pd Stacked Layer for nano-scale CMOSFETs (나노급 CMOSFET을 위한 Pd 적층구조를 갖는 열안정 높은 Ni-silicide)

  • Yu, Ji-Won;Zhang, Ying-Ying;Park, Kee-Young;Li, Shi-Guang;Zhong, Zhun;Jung, Soon-Yen;Yim, Kyoung-Yean;Lee, Ga-Won;Wang, Jin-Suk;Lee, Hi-Deok
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 2008.11a
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    • pp.10-10
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    • 2008
  • Silicide is inevitable for CMOSFETs to reduce RC delay by reducing the sheet resistance of gate and source/drain regions. Ni-silicide is a promising material which can be used for the 65nm CMOS technologies. Ni-silicide was proposed in order to make up for the weak points of Co-silicide and Ti-silicide, such as the high consumption of silicon and the line width limitation. Low resistivity NiSi can be formed at low temperature ($\sim500^{\circ}C$) with only one-step heat treat. Ni silicide also has less dependence of sheet resistance on line width and less consumption of silicon because of low resistivity NiSi phase. However, the low thermal stability of the Ni-silicide is a major problem for the post process implementation, such as metalization or ILD(inter layer dielectric) process, that is, it is crucial to prevent both the agglomeration of mono-silicide and its transformation into $NiSi_2$. To solve the thermal immune problem of Ni-silicide, various studies, such as capping layer and inter layer, have been worked. In this paper, the Ni-silicide utilizing Pd stacked layer (Pd/Ni/TiN) was studied for highly thermal immune nano-scale CMOSFETs technology. The proposed structure was compared with NiITiN structure and showed much better thermal stability than Ni/TiN.

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Analysis of upconversion luminescence from Yb3+, Er3+ co-doped SrMoO4 (Yb3+와 Er3+ 이온이 동시 도핑 된 SrMoO4에서 발생되는 업컨버젼 현상에 대한 분석)

  • Chung, Jun Ho;Heo, Tae Hyung;Lee, Jeong Hoon;Lee, Sang Yeop;Kang, Suk Hyun;Kim, So Yeon;Kim, Sae Am;Choi, Bong Geun;Shim, Kwang Bo
    • Journal of the Korean Crystal Growth and Crystal Technology
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    • v.22 no.5
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    • pp.241-246
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    • 2012
  • $Yb^{3+}$, $Er^{3+}$ co-doped $SrMoO_4$ ($SrMoO_4$ : $Yb^{3+}/Er^{3+}$) specimens have been successfully synthesized via the complex citrate-gel method and their structural and optical properties were investigated in detail. Under 980 nm excitation, $SrMoO_4$ : $Yb^{3+}/Er^{3+}$ UC phosphors have been emitted strong green luminescence at 530 and 550 nm with weak red emission around 670 nm corresponding to the intra 4f transitions of $Er^{3+}$ ($^4F_{9/2}$, $^2H_{11/2}$, $^4S_{3/2}$) ${\rightarrow}$ $Er^{3+}$ ($^4I_{15/2}$). The optimal doping concentrations of $Er^{3+}$ and $Yb^{3+}$ ions were verified to 2/16 mol% and a possible upconversion mechanism depending on pump power dependence is studied in detail.

Upconversion luminescence from poly-crystalline Yb3+, Er3+ co-doped NaGd(MoO4)2 by simple solid state method (Er3+, Yb3+ 이온이 동시 도핑된 NaGd(MoO4)2의 업컨버젼 분석)

  • Kang, Suk Hyun;Kang, Hyo Sang;Lee, Hee Ae;Shim, Kwang Bo
    • Journal of the Korean Crystal Growth and Crystal Technology
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    • v.26 no.4
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    • pp.159-163
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    • 2016
  • Up-conversion (UC) luminescence properties of polycrystalline $Er^{3+}/Yb^{3+}$ doped $NaGd(MoO_4)_2$ phosphors synthesized by a simple solid-state reaction method were investigated in detail. Used to 980 nm excitation (InfraRed area), $Er^{3+}/Yb^{3+}$ co-doped $NaGd(MoO_4)_2$ exhibited very weak red emissions near 650 and 670 nm, and very strong green UC emissions at 540 and 550 nm corresponding to the infra 4f transitions of $Er^{3+}(^4F_{9/2},\;^2H_{11/2},\;^4S_{3/2}){\rightarrow}Er^{3+}(^4I_{15/2})$. The optimum doping concentration of $Er^{3+}$, $Yb^{3+}$ for highest emission intensity was determined by XRD and PL analysis. The $Er^{3+}/Yb^{3+}$ (10.0/10.0 mol%) co-doped $NaGd(MoO_4)_2$ phosphor sample exhibited very strong shiny green emission. A possible UC mechanism for $Er^{3+}/Yb^{3+}$ co-doped $NaGd(MoO_4)_2$ depending on the pump power dependence was discussed.

A Report on the Inter-Gene Correlations in cDNA Microarray Data Sets (cDNA 마이크로어레이에서 유전자간 상관 관계에 대한 보고)

  • Kim, Byung-Soo;Jang, Jee-Sun;Kim, Sang-Cheol;Lim, Jo-Han
    • The Korean Journal of Applied Statistics
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    • v.22 no.3
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    • pp.617-626
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    • 2009
  • A series of recent papers reported that the inter-gene correlations in Affymetrix microarray data sets were strong and long-ranged, and the assumption of independence or weak dependence among gene expression signals which was often employed without justification was in conflict with actual data. Qui et al. (2005) indicated that applying the nonparametric empirical Bayes method in which test statistics were pooled across genes for performing the statistical inference resulted in the large variance of the number of differentially expressed genes. Qui et al. (2005) attributed this effect to strong and long-ranged inter-gene correlations. Klebanov and Yakovlev (2007) demonstrated that the inter-gene correlations provided a rich source of information rather than being a nuisance in the statistical analysis and they developed, by transforming the original gene expression sequence, a sequence of independent random variables which they referred to as a ${\delta}$-sequence. We note in this report using two cDNA microarray data sets experimented in this country that the strong and long-ranged inter-gene correlations were still valid in cDNA microarray data and also the ${\delta}$-sequence of independence could be derived from the cDNA microarray data. This note suggests that the inter-gene correlations be considered in the future analysis of the cDNA microarray data sets.

Photo Spacer Induced Bistable Mode Plastic PSFLCDs for High Mechanical Stability

  • Kim, Yu-Jin;Park, Seo-Kyu;Kwon, Soon-Bum;Lee, Ji-Hoon;Son, Ock-Soo;Lim, Tong-Kun
    • 한국정보디스플레이학회:학술대회논문집
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    • 2005.07a
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    • pp.489-492
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    • 2005
  • We report new polymer stabilized ferroelectric liquid crystal (PSFLC) cells with mechanical stability which is achievable by introducing photospacers in the cells. It was found that the mechanical st ability of the PSFLC cell was effected by introduction of photo spacers. We analyzed the dependence of mechanical stability and memory property on the density of photospacers in the PSFLC cell. The stability and memory properties of PSFLC Cells depending on photospacer density are discussed. 1. Introduction Recently, flexible displays have attracted much attention because they have remarkable advantages: thinner, lighter, non-breakable and conformable features. Flexible displays have various potential applications such as e-book and e-paper displays utilizing the distinct features. E-book and E-paper displays demand very low power consumption, so that bistable memory liquid crystal modes are required in case of flexible plastic LCDs for those application. Three kinds of memory LC modes have been developed; bistable nematic, bistable cholesteric and bistable FLC. Among them SSFLC as one of bistable FLC has big advantages such as low driving voltage, wide view angle and fast response time, SSFLC cells are, however, very weak against mechanical shock. Polymer stabilized FLC (PSFLC) has been developed to overcome the poor mechanical stability of SSFLC. PSFLC was known to have network structure that FLCs are oriented with smectic layer ordering in polymer network. The polymer network stabilizes the FLC orientation, which leads to improvement of mechanical stability of PSFLCD. A lot of studies have been done for the application of PSFLC to flexible $LCDs.^{[1{\sim}12]}$ However, it should be noted that PSFLC does not have sufficient mechanical stability for the particular applications such as smart card LCD, where LCD is highly bendable.Bead spacer was mainly used to maintain cell gap of conventional PSFLCDs. But the spacer density of it is not locally uniform in the cell, so that it is generally difficult that the PSFLCDs with bead spacers show sufficient mechanical stability. In order to more improve the mechanical stability of PSFLCDs, we introduced photospacers into PSFLCDs. In this paper, we describe the improvement of mechanical stability by introducing photospacers into PSFLCDs.

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The Intraday Lead-Lag Relationships between the Stock Index and the Stock Index Futures Market in Korea and China (한국과 중국의 현물시장과 주가지수선물시장간의 선-후행관계에 관한 연구)

  • Seo, Sang-Gu
    • Management & Information Systems Review
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    • v.32 no.4
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    • pp.189-207
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    • 2013
  • Using high-frequency data for 2 years, this study investigates intraday lead-lag relationship between stock index and stock index futures markets in Korea and China. We found that there are some differences in price discovery and volatility transmission between Korea and China after the stock index futures markets was introduced. Following Stoll-Whaley(1990) and Chan(1992), the multiple regression is estimated to examine the lead-lag patterns between the two markets by Newey-West's(1987) heteroskedasticity and autocorrelation consistent covariance matrix(HAC matrix). Empirical results of KOSPI 200 shows that the futures market leads the cash market and weak evidence that the cash market leads the futures market. New market information disseminates in the futures market before the stock market with index arbitrageurs then stepping in quickly to bring the cost-of-carry relation back into alignment. The regression tests for the conditional volatility which is estimated using EGARCH model do not show that there is a clear pattern of the futures market leading the stock market in terms of the volatility even though controlling nonsynchronous trading effects. This implies that information in price innovations that originate in the futures market is transmitted to the volatility of the cash market. Empirical results of CSI 300 shows that the cash market is found to play a more dominant role in the price discovery process after the Chinese index started a sharp decline immediately after the stock index futures were introduced. The new stock index futures markets does not function well in its price discovery performance at its infancy stage, apparently due to high barriers to entry into this emerging futures markets. Based on EGAECH model, the results uncover strong bi-directional dependence in the intraday volatility of both markets.

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Review and Prospects on Venture Firm Accumulation Center: The Case of Kwan-Ak Venture Town (벤처기업집적시설의 현황과 문제점 및 개선방안에 관한 연구 서울시 관악구 벤처타운 사례를 중심으로)

  • 최지훈
    • Journal of the Economic Geographical Society of Korea
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    • v.3 no.2
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    • pp.81-96
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    • 2000
  • The study examines the present condition and prospects of venture firm accumulation center in the case of kwan-ak venture town. The survey shows most of companies have been founded since 1997. Their major items are software development and the average employees are under 10 workers. According to the questionary about the type of R&D and the level of innovation, technology innovation such as the development of new product is advanced whereas tacit innovation like inter-firm cooperation is very weak. And the source of idea and information is concentrated on the within-firms and research center As a result of the analysis of regional linkage, the dependence of production and R & D is large on kwan-ak-gu, but sales and information services have emphasis on Seoul area. In the light of the affiliation of inter-firm, they response sympathy with cooperation, but could not strengthen their commercial ties yet. At last, the policy for venture firm accumulation center must intend to make tacit measures through inventing of system instead of the simple means such as the assistance of location, finance and tax.

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A Study on Isolation Performance of High Damping Rubber Bearing Through Shaking Table Test and Analysis (진동대 실험 및 해석을 통한 고감쇠 고무받침의 면진성능 연구)

  • Kim, Hu-Seung;Oh, Ju
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.17 no.5
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    • pp.601-611
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    • 2016
  • The research, development and use of seismic isolation systems have been increasing with the gradual development of structure safety assurance methods for earthquakes. The High Damping Rubber Bearing (HDRB), one type of seismic isolation system, is a Laminated Rubber Bearing using special High Damping Rubber. However, as its damping function is slightly lower than that of the Lead Rubber Bearing, a similar seismic isolation system, its utilization has not been high. However, the HDRB has a superior damping force to the Natural Rubber Bearing, which has similar materials and shapes, and the existing Lead Rubber Bearing has a maleficence problem in that it contains lead. Thus, studies on HDRBs that do not use lead have increased. In this study, a test targeting the HDRB was done to examine its various dependence properties, such as its compressive stress, frequency and repeated loading. To evaluate the HDRB's seismic performance in response to several earthquake waves, the shaking table test was performed and the results analyzed. The test used the downscaled bridge model and the HDRB was divided into seismic and non-seismic isolation. Consequently, when the HDRB was applied, the damping effect was higher in the non-seismic case. However, its responses on weak foundations, such as in Mexico City, represented increased shapes. Thus, its seismic isolator.