• Title/Summary/Keyword: External Diffusion

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An A2CL Algorithm based on Information Optimization Strategy for MMRS

  • Dong, Qianhui;Li, Yibing;Sun, Qian;Tian, Yuan
    • KSII Transactions on Internet and Information Systems (TIIS)
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    • v.14 no.4
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    • pp.1603-1623
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    • 2020
  • Multiple Mobile Robots System (MMRS) has shown many attractive features in lots of real-world applications that motivate their rapid and wide diffusion. In MMRS, the Cooperative Localization (CL) is the basis and premise of its high-performance task. However, the statistical characteristics of the system noise should be already known in traditional CL algorithms, which is difficult to satisfy in actual MMRS because of the numerous of disturbances form the complex external environment. So the CL accuracy will be reduced. To solve this problem, an improved Adaptive Active Cooperative Localization (A2CL) algorithm based on information optimization strategy for MMRS is proposed in this manuscript. In this manuscript, an adaptive information fusion algorithm based on the variance component estimation under Extended Kalman filter (VCEKF) method for MMRS is introduced firstly to enhance the robustness and accuracy of information fusion by estimating the covariance matrix of the system noise or observation noise in real time. Besides, to decrease the effect of observation uncertainty on CL accuracy further, an observation optimization strategy based on information theory, the Model Predictive Control (MPC) strategy, is used here to maximize the information amount from observations. And semi-physical simulation experiments were carried out to verity the A2CL algorithm's performance finally. Results proved that the presented A2CL algorithm based on information optimization strategy for MMRS cannot only enhance the CL accuracy effectively but also have good robustness.

Factors Affecting the Adoption of Innovative Service System in Public Sectors : A Case Study on Implementing Double Entry Bookkeeping With Accrual Basis in Government Accounting System (공공부문의 서비스 혁신 수용에 관한 실증연구 : 중앙정부 및 지방자치단체 회계담당자의 복식부기${\cdot}$발생주의 회계시스템 도입에 관한 사례를 중심으로)

  • Pyun Ho-Bum;Han Kwang-Hyun;Kim Tae Ung
    • Korean Management Science Review
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    • v.22 no.1
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    • pp.103-125
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    • 2005
  • Korean government is planning to adopt double entry bookkeeping with accrual basis in the government accounting system. This paper attempts to identify influencing attitudes of information producers toward the acceptance of the new service system. Several models are introduced, including Luder's Contingency Model, Cheng's Politico-Economic Model of Accounting Policy Choice, Roger's Diffusion of innovation, and Davis's Technology Acceptance Model(TAM). A set of constructs are developed as fellows : information producers' knowledges, experiences, altitudes toward the reform, characteristics of cash based accounting system and new accrual based system, a chief executive officer's willingness to support, availability of supporting systems, and social Influences from external environment. This study also incudes hey factors used in TAM, such as perceived usefulness and ease of use. Survey responses are gathered from accounting officers in government ministries and agencies as well as from local governments. Regression analysis shows that, for information producers, both 'perceived ease of use' and 'perceived usefulness' of the new system are the best explanatory variable for the dependent variable. It has also found that 'perceived usefulness' is explained best by individual characteristics such as knowledge and experiences, quality of current cash based s1n91e entry bookkeeping system, chief executive's support, Positive supporting systems and social influences. The useful guidelines for implementing double-entry bookkeeping system with accrual basis are also provided.

A study on the realities of color in apartment exteriors (아파트 외부 색채 환경의 실태연구-일산 신도시 아파트 중심으로-)

  • 박연선;김지혜
    • Archives of design research
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    • v.20
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    • pp.265-276
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    • 1997
  • I intend to grope for the desirable outdoor color environment creation plan through researching situation of our apartment houses color environment and grasping the point at issue. The rearch was made that Ilsan(16 items) new city apartment were selected and the color seperately measured such as the dominant, the aid, the accent colors through applied color component ratio was researched by calculating square measure of matched colors and through that the evaluation of apartment complex color environment was formed. The planned construction problems were issued from comparing the planned scheme and the present carrying color status guide by investigating the color plan applied Ilsan new city. The current out apartment outdoor color environment is poor, and the color plan of the early stage has many insufficient parts and many operation errors. For the creation of desirable color environment, the color plan establishment by regional characteristics, the color environment management, though exhaustive color consultation, and the external construction technique improvement, the standard color sheet diffusion, the color understanding of architects, the public relations (P.R), the education on the importance of color are required.

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Evaluation of Forward Osmosis (FO) Membrane Performances in a Non-Pressurized Membrane System (비가압식 막 공정을 통한 정삼투막 성능 평가)

  • Kim, Bongchul;Boo, Chanhee;Lee, Sangyoup;Hong, Seungkwan
    • Journal of Korean Society on Water Environment
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    • v.28 no.2
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    • pp.292-299
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    • 2012
  • The objective of this study is to develop a novel method for evaluating forward osmosis (FO) membrane performances using a non-pressurized FO system. Basic membrane performance parameters including water (A) and solute (B) permeability coefficients and unique parameter for FO membrane such as the support layer structural parameter (S) were determined in two FO modes (i.e., active layer faces feed solution (AL-FS) and active layer faces draw solution (AL-DS)). Futhermore, these parameters were compared with those determined in a pressurized reverse osmosis (RO) system. Theoretical water flux was calculated by employing these parameters to a model that accounts for the effects of both internal and external concentration polarization. Water flux from FO experiment was compared to theoretical water fluxes for assessing the reliability of those parameters determined in three different operation modes (i.e., AL-FS FO, AL-DS FO, and RO modes). It is demonstrated that FO membrane performance parameters can be accurately measured in non-pressurized FO mode. Specifically, membrane performance parameters determined in AL-DS FO mode most accurately predict FO water flux. This implies that the evaluation of FO membrane performances should be performed in non-pressurized FO mode, which can prevent membrane compaction and/or defect and more precisely reflect FO operation conditions.

Near-field Optical Lithography for High-aspect-ratio Patterning by Using Electric Field Enhanced Postexposure Baking (전기장이 적용된 노광후굽기 공정에 의한 고종횡비 근접장 광 리소그래피)

  • Kim, Seok;Jang, Jin-Hee;Kim, Yong-Woo;Jung, Ho-Won;Hahn, Jae-Won
    • Korean Journal of Optics and Photonics
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    • v.21 no.6
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    • pp.241-246
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    • 2010
  • In this paper, we propose an electric field enhanced postexposure baking (EFE-PEB) method to obtain deep and high aspect ratio pattern profile in near-field recording. To describe the photoacid distribution under an external electric field during the PEB, we derived the governing equations based on Fick's second law of diffusion. From the results of the numerical calculations, it is found that the vertical movement of photoacid increases while the lateral movement is stationary as electric field varies from 0 to $8.0{\times}10^6\;V/m$. Also, it is proven that the profile of near-field recording is improved by using the EFE-PEB method with increased depth, higher aspect ratio and larger sidewall angle.

Charge Transport Characteristics of Dye-Sensitized TiO2 Nanorods with Different Aspect Ratios

  • Kim, Eun-Yi;Lee, Wan-In;Whang, Chin Myung
    • Bulletin of the Korean Chemical Society
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    • v.32 no.8
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    • pp.2671-2676
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    • 2011
  • Nanocrystalline $TiO_2$ spherical particle (NP) with a dimension of 5 ${\times}$ 5.5 nm and several nanorods (NR) with different aspect ratios (diameter ${\times}$ length: 5 ${\times}$ 8.5, 4 ${\times}$ 15, 4 ${\times}$ 18 and 3.5 ${\times}$ 22 nm) were selectively synthesized by a solvothermal process combined with non-hydrolytic sol-gel reaction. With varying the molar ratio of TTIP to oleic acid from 1:1 to 1:16, the NRs in the pure anatase phase were elongated to the c-axis direction. The prepared NP and NRs were applied for the formation of nanoporous $TiO_2$ layers in dye-sensitized solar cell (DSSC). Among them, NR2 ($TiO_2$ nanorod with 4 ${\times}$ 15 nm) exhibited the highest cell performance: Its photovoltaic conversion efficiency (${\eta}$) of 6.07%, with $J_{sc}$ of 13.473 mA/$cm^2$, $V_{oc}$ of 0.640 V, and FF of 70.32%, was 1.44 times that of NP with a size of 5 ${\times}$ 5.5 nm. It was observed from the transient photoelectron spectroscopy and the incident photon to current conversion efficiency (IPCE) spectra that the $TiO_2$ films derived from NR2 demonstrate the longest electron diffusion length ($L_e$) and the highest external quantum efficiency (EQE).

A Study on the Variations on the Types of Korean Women′s Jackets - emphasized on the period from the Liberation in 1945 to 2000 - (한국 여성상의(Jacket)의 변화 고찰 - 1945년∼2000년을 중심으로 -)

  • Lee Sang-Eun;Kim Young-Ran
    • Journal of the Korea Fashion and Costume Design Association
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    • v.6 no.3
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    • pp.153-167
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    • 2004
  • Korea had suffered the colony of Japanese imperialism and the Korean War from the invasion of the external circumstances. Such special situation made new influences on the clothing habits. The types of Korean women clothing could escape from the traditional style that had been maintained for thousands of years. The foreign clothes for Korean women had undergone various changes from the Liberation in 1945. The jackets that had been introduced to Korea at the Enlightenment period had become popular outfits for men. The jackets made big influences on the changes such as the social advances for women from the times background of the Liberation. The jackets possess very important meaning for the changes in the diffusion of feminism and fashion. Therefore, this research tries to investigate the forms, silhouettes, changes and structures of the jackets such as the locations of the collar, the sleeve, and the waste line. The process of the changes in the style of women jackets is also analyzed from the silhouette and the structure method. The development and changes will be understood of Korean women's jackets. The Korean women's jackets should also be examined further with the history of foreign clothing from now on. The fashion to be introduced from important society cultural phenomena and the Western Europe has been reflected into the changes in the style of Korean female jackets. Also, dramatic changes in the style of clothing indicate that the society had experienced a great deal of changes. It is verified that foreign clothes have been interacted with the stream of times worldwide. After the Liberation, the female jackets become a uniform style which just followed the Western European style. However, a season trend has been announced from the SFAA since 1990. Since then trendy jackets have been detailed more with this chance.

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Moment Analysis (MA) of Lysozyme in Cation Exchange High Performance Liquid Chromatography (HPLC) (양이온교환 고성능액체크로마토그래피에서 라이소자임의 모멘트 분석)

  • Ko, Kwan Young;Kim, In Ho
    • Korean Chemical Engineering Research
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    • v.54 no.4
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    • pp.487-493
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    • 2016
  • The moment analysis of lysozyme was implemented using chromatograms that were obtained from weak cation exchange column in high performance liquid chromatography system. Three elution sodium phosphate buffers containing 1.0, 0.75, 0.5M sodium chloride were used. Experiments were conducted by varying flow rate, elution sodium chloride concentration, and lysozyme solute concentration. The general rate (GR) model was employed to calculate the first moment and the second moment. By plotting $L/u_0$ vs. $({\mu}_1-t_0)/(1-{\varepsilon}_e)(1-{\varepsilon}_i)$] equilibrium constants (K) were obtained from first moment analysis. Intra-particle diffusivity was obtained from theoretical plate number data. Based on the results of moment analysis, van Deemter plots were drawn in order to investigate the contributions of $H_{ax}$, $H_f$, and $H_d$ to total Height Equivalent to a Theoretical Plate (HETP, $H_{total}$). The effect of intra-particle diffusion ($H_d$) was the most dominant factor contributing to HETP while external mass transfer ($H_f$) was negligible factor.

Thermo-Sensitive Polyurethane Membrane with Controllable Water Vapor Permeation for Food Packaging

  • Zhou, Hu;Shit, Huanhuan;Fan, Haojun;Zhou, Jian;Yuan, Jixin
    • Macromolecular Research
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    • v.17 no.7
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    • pp.528-532
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    • 2009
  • The size and shape of free volume (FV) holes available in membrane materials control the rate of gas diffusion and its permeability. Based on this principle, a segmented, thermo-sensitive polyurethane (TSPU) membrane with functional gate, i.e., the ability to sense and respond to external thermo-stimuli, was synthesized. This smart membrane exhibited close-open characteristics to the size of the FV hole and water vapor permeation and thus can be used as smart food packaging materials. Differential scanning calorimetry (DSC), dynamic mechanical analysis (DMA), positron annihilation lifetimes (PAL) and water vapor permeability (WVP) were used to evaluate how the morphological structure of TSPU and the temperature influence the FV holes size. In DSC and DMA studies, TSPU with a crystalline transition reversible phase showed an obvious phase-separated structure and a phase transition temperature at $53^{\circ}C$ (defined as the switch temperature and used as a functional gate). Moreover, the switch temperature ($T_s$) and the thermal-sensitivity of TSPU remained available after two or three thermal cyclic processes. The PAL study indicated that the FV hole size of TSPU is closely related to the $T_s$. When the temperature varied cyclically from $T_s-10{\circ}C$ to $T_s+10^{\circ}C$, the average radius (R) of the FV holes of the TSPU membrane also shifted cyclically from 0.23 to 0.467 nm, exhibiting an "open-close" feature. As a result, the WVP of the TSPU membrane also shifted cyclically from 4.30 to $8.58\;kg/m^2{\cdot}d$, which produced an "increase-decrease" response to the thermo-stimuli. This phase transition accompanying significant changes in the FV hole size and WVP can be used to develop "smart materials" with functional gates and controllable water vapor permeation, which support the possible applications of TSPU for food packaging.

The Influence of Entrepreneurial Competences on Corporate Performance of Technology-based Start-ups (창업가역량과 창업보육 프로그램 지원이 기술창업기업 경영성과에 미치는 영향 : 창업기업 역량의 매개효과 중심으로)

  • Kim, Jinhan;Cho, Jinhyung;Lee, Saejae
    • Journal of Korean Society of Industrial and Systems Engineering
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    • v.43 no.1
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    • pp.132-142
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    • 2020
  • Many countries around the world are pursuing various support policies to foster start-ups national widely in order to secure new economic growth engines in the era of the Fourth Industrial Revolution. The South Korean government announced the diffusion strategy for the 2'nd round Start-up Boom in March 2019 and is promoting the support policies for start-up incubating by various programs. Many incubators and startup accelerators operate various kinds of programs to foster start-ups using government financial supports. The purpose of this study is to investigate the effects of entrepreneurship and technical capability of entrepreneurs as the internal factors of the technology-based start-ups and the effects of programs supported by the government as an external factor on the corporate performance of a start-up company, and the mediating effects of core competence of start-ups were analyzed using SPSS and AMOS. The results show that the entrepreneurship, technical capability and the programs supported by incubators or accelerators had no direct effects on the corporate performance of a start-up, but the core competence of the company had complete mediating effects. In addition, the type of program supported by the comprehensive accelerator programs or the marketing supports had effects on the core competence rather than simple financial supports. Lastly, the policy proposals for incubating program support and future research directions along with the limitation are suggested.