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Active Force Control of Electro-Hydraulic Hybrid Load Simulator using Quantitative Feedback Theory (QFT를 이용한 전기유압 하이브리드 부하 시뮬레이터의 능동 힘제어)

  • Yoon, Joo-Hyeon;Ahn, Kyoung-Kwan;Truong, Dinh Quang;Jo, Woo-Geun
    • Journal of the Korean Society for Precision Engineering
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    • v.26 no.2
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    • pp.45-53
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    • 2009
  • Today, reduction of $CO_2$ exhaustion gas for global-warming prevention becomes important issues in all industrial fields. Hydraulic systems have been widely used in industrial applications due to high power density and so on. However hydraulic pump is always being operated by engine or electric motor in the conventional hydraulic system. Therefore most of the conventional hydraulic system is not efficient system. Recently, an electro-hydraulic hybrid system, which combines electric and hydraulic technology in a compact unit, can be adapted to a wide variety of force, speed and torque requirements. In the electro-hydraulic hybrid system, hydraulic pump is operated by electric motor only when hydraulic power is needed. Therefore the electro-hydraulic system can reduce the energy consumption drastically when compared to the conventional hydraulic systems. This paper presents a new kind of hydraulic load simulator which is composed of electro-hydraulic hybrid system. Disturbances in the real working condition make the control performance decrease or go bad. QFT controller is designed to eliminate or reduce the disturbance and improve the control performance of the electro-hydraulic load simulator. Experimental results show that the proposed controller is verified to apply for electro-hydraulic hybrid system with varied external disturbances.

Effects of Different Precursors on the Surface Mn Species Over $MnO_x/TiO_2$ for Low-temperature SCR of NOx with $NH_3$

  • Kim, Jang-Hoon;Yoon, Sang-Hyun;Lee, Hee-Soo
    • Proceedings of the Materials Research Society of Korea Conference
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    • 2011.10a
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    • pp.29.1-29.1
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    • 2011
  • The selective catalytic reduction (SCR) of $MnO_x$ with $NH_3$ is an effective method for the removal of $MnO_x$ from stationary system. The typical catalyst for this method is $V_2O_5-WO_3(MoO_3)/TiO_2$, caused by the high activity and stability. However, This catalyst is active within $300{\sim}400^{\circ}C$ and occurs the pore plugging from the deposition of ammonium sulfate salts on the catalysts surface. It needs to locate the SCR unit after the desulfurizer and electrostatic precipitator without reheating of the flue gas as well as deposition of dust on the catalyst. The manganese oxides supported on titania catalysts have attracted interest because of its high SCR activity at low temperature. The catalytic activity of $MnO_x/TiO_2$ SCR catalyst with different manganese precursors have investigated for low-temperature SCR in terms of structural, morphological, and physico-chemical analyses. The $MnO_x/TiO_2$ were prepared from three different precursors such as manganese nitrate, manganese acetate (II), and manganese acetate (III) by the sol-gel method and then it calcinated at $500^{\circ}C$ for 2 hr. The structural analysis was carried out to identify the phase transition and the change intensity of catalytic activity by various manganese precursors was analyzed by FT-IR and Raman spectroscopy. These different precursors also led to various surface Mn concentrations indicated by SEM. The Mn acetate (III) tends to be more suppressive the crystalline phase (rutile), and it has not only smaller particle size, but also better distributed than the others. It was confirmed that the catalytic activity of MA (III)-$MnO_x/TiO_2$ was the highest among them.

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A Case Study of U.S. Academic Libraries' Research Data Support Services (미국 대학도서관의 연구데이터 지원 서비스 사례 연구)

  • Shim, Wonsik
    • Journal of the Korean Society for Library and Information Science
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    • v.50 no.4
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    • pp.311-332
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    • 2016
  • Academic libraries have actively responded to social requirements and changes in scholarly communication system. In recent years, social and scholarly requirements for systematic management and sharing of research data have become apparent. Major countries including U.S., UK and Australia have begun national policies requiring management and sharing of research data from publicly funded R&D projects. This case study identified four academic libraries in the US with active research data support services and analyzed them in terms of how they established dedicated unit and the extent of services in the areas of instruction, consulting and system support. The analysis provides context for academic libraries in Korea in formulating their future research data strategies. The core of the recommendation is primarily concerned with developing instructional services and strengthening library's capabilities for research data management and sharing.

PQQ-Dependent Organic Acid Production and Effect on Common Bean Growth by Rhizobium tropici CIAT 899

  • Cho, Young-Shin;Park, Ro-Dong;Kim, Yong-Woong;Hwangbo, Hoon;Jung, Woo-Jin;Suh, Jang-Sun;Koo, Bon-Sung;Krishnan, Hari-B.;Kim, Kil-Yong
    • Journal of Microbiology and Biotechnology
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    • v.13 no.6
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    • pp.955-959
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    • 2003
  • Rhizobium tropici CIAT 899 is capable of synthesizing inactive apo-glucose dehydrogenase (GDH). To become an active holo enzyme, the GDH requires a cofactor, PQQ. When R. tropici CIAT 899 was grown in a broth culture medium containing hydroxyapatite and pyrrolo quinoline quinone (PQQ), pH decreased while the concentration of soluble P increased. The solubilization of hydroxyapatite was associated with the production of gluconic acid and 2-ketogluconic acids. The organic acid production and P solubilization were greatly enhanced when the bacterium was grown with air supply. Effect of R. tropici CIAT 899 with (CI+PQQ) and without PQQ (CI) on the common bean growth was examined. Shoot and root weight, and N and P contents in CI+PQQ treatment, were significantly higher than those in control and CI treatment. Nodule weight and acetylene reducing activities were also significantly higher in CI+PQQ treatment than in other treatments.

Medium Optimization and Application of Affinity Column Chromatography for Trypsin Production from Recombinant Streptomyces griseus

  • Chi, Won-Jae;Song, Ju-Hyun;Oh, Eun-A.;Park, Seong-Whan;Chang, Yong-Keun;Kim, Eung-Soo;Hong, Soon-Kwang
    • Journal of Microbiology and Biotechnology
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    • v.19 no.10
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    • pp.1191-1196
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    • 2009
  • The production of Streptomyces griseus trypsin (SGT) by S. griseus IFO13350 transformed with the expression vector pWHM3-TR1R2, containing sprT encoding SGT and the two positive regulatory genes sgtR1 and sgtR2, was investigated in various media. Cultivation in Ferm-0 gave 1.4 times more trypsin activity than in C5/L medium. In addition, replacement of 2% glucose and 1% skim milk in Ferm-0 with 2% dextrin and 1% tryptone (designated Ferm-II) enhanced trypsin activity 4.1-fold. To simplify the purification process, the supernatant from the S. griseus transformant cultured in Ferm-II medium was fractionated with ammonium sulfate (25-55%), then subjected to Hitrap Benzamidine FF affinity column chromatography. The specific activity of SGT purified by one-step chromatography was 69,550 unit/mg protein and the overall purification yield was above 8%, indicating that this method is more effective than those previously reported. Purified SGT was most active at pH 8.0 and $50^{\circ}C$, and it maintained activity between pH 7.0 and 9.0 and at temperatures up to $70^{\circ}C$. These enzymatic properties are very similar to those of authentic eukaryotic trypsin purified from bovine pancreas.

A Study on the Visual Perception Space Structure Analysis of Exhibition Contents Organization in Natural History Museum (자연사박물관 전시내용구성의 시지각적 공간구조분석에 관한 연구)

  • Kim, Eun-Jung;Hong, Kwan-Seon
    • Korean Institute of Interior Design Journal
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    • v.18 no.2
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    • pp.80-92
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    • 2009
  • Natural history museums preserve and manage the creatures living in each country, so they play unique roles for bio-diversity, and in fact, their roles are really instrumental for the collection, preservation, research, exhibition and education of creatures in the 21st century. Therefore, this research has the purpose to survey the status of our country's existing natural history museums, analyze their visual perception space structural characteristics, and ultimately utilize their characteristics as basic data in planning out and designing spaces of natural history museums to be established later on. As for the research scope, the research selected as research subjects 7 natural history museums that currently have composite set of open type and mixed type and have been accommodating comparatively active exhibitions since 2000 among 10 or so natural history museums in our country. Research method is that the research analyzed the exhibition spaces of 7 natural history museums by using depthmap program which can analyze space with visual graph analysis function, and analyzed the visibility among unit areas by each natural history museum integration and exhibition contents composition. In such analysis method, the research was able to quantitatively analyze the visual characteristics of exhibition space that induces and adjusts the motion of audience. Visual perception quantitative analysis as in this research will enhance exhibition design by considering the correlation between audience and exhibited items when planning out natural history museums space to be established later on.

Development of NCS and Embedded System-Based Training Program for Smart Manufacturing Application (스마트제조 적용을 위한 NCS 및 임베디드 기반 교육훈련 프로그램 개발)

  • Lee, Woo-Young;Son, Deuk-soo;Oh, Jae-Jun;Yu, Jong-Hyeok
    • Journal of Practical Engineering Education
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    • v.11 no.2
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    • pp.283-289
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    • 2019
  • Recently, product mobility, data compatibility and communication connectivity have become very important to the control system, depending on the application of smart manufacturing. Accordingly, embedded systems are essential in all industries including home appliances, telecommunication, and national defense. Therefore, the demand for embedded system development personnel is increasing further, and education and training programs are needed to combine the practical skills of industrial sites, including programming skills and hardware. Currently, embedded system education offers a variety of education centered on Aduino, but this is mostly for beginners and is not sufficient for majors. In addition, while various prototype studies related to embedded systems are active, the training and training programs for working-level human resources needed at industrial sites are very scarce. Therefore, in order to foster the working personnel of the embedded system for the application of smart manufacturing, this paper selected the capability unit through in-depth interviews and survey analysis of 10 experts based on NCS, and developed education and training programs and contents.

A Study on the Implementation of the Web-Camera System for Realtime Monitoring (실시간 영상 감시를 위한 웹 카메라 시스템의 구현에 관한 연구)

  • Ahn, Young-Min;Jin, Hyun-Joon;Park, Nho-Kyung
    • Journal of IKEEE
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    • v.5 no.2 s.9
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    • pp.174-181
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    • 2001
  • In this study, the architecture of the Web Camera System for realtime monitoring on Internet is proposed and implemented in two different structures. In the one architecture, a Web-server and a Camera-server are implemented on the same system, and the system transfers motion pictures compressed to JPEG file to users on the WWW(World Wide Web). In the other architecture, the Web-server and the Camera-server are implemented on different systems, and the motion pictures are transferred from the Camera-server to the Web-server, and finally to users. For JPEG image transferring in the Web Camera system, the Java Applet and the Java Script are used to maximize flexibility of the system from the Operating system and the Web browsers. In order to compare system performance between two architectures, data traffic is measured and simulated in the unit of byte per second.

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Risk Factors for Surgical Site Infections in Patients Undergoing Craniotomy (개두술을 받은 환자의 수술부위감염 관련요인 분석)

  • Cha, Kyeong-Sook;Cho, Ok-Hee;Yoo, So-Yeon
    • Journal of Korean Academy of Nursing
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    • v.40 no.2
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    • pp.298-305
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    • 2010
  • Purpose: The objectives of this study were to determine the prevalence, incidence, and risk factors for postoperative surgical site infections (SSIs) after craniotomy. Methods: This study was a retrospective case-control study of 103 patients who had craniotomies between March 2007 and December 2008. A retrospective review of prospectively collected databases of consecutive patients who underwent craniotomy was done. SSIs were defined by using the Centers for Disease Control criteria. Twenty-six cases (infection) and 77 controls (no infection) were matched for age, gender and time of surgery. Descriptive analysis, t-test, $\chi^2$-test and logistic regression analyses were used for data analysis. Results: The statistical difference between cases and controls was significant for hospital length of stay (>14 days), intensive care unit stay more than 15 days, Glasgrow Coma Scale (GCS) score (${\leq}7$ days), extra-ventricular drainage and coexistent infection. Risk factors were identified by logistic regression and included hospital length of stay of more than 14 days (odds ratio [OR]=23.39, 95% confidence interval [CI]=2.53-216.11) and GCS score (${\leq}7$ scores) (OR=4.71, 95% CI=1.64-13.50). Conclusion: The results of this study show that patients are at high risk for infection when they have a low level of consciousness or their length hospital stay is long term. Nurses have to take an active and continuous approach to infection control to help with patients having these risk factors.

The Effect of Problem-Based Learning on Adolescent Consumer Consciousness and skill (문제충심학습(PBL)이 청소년 소비자 의식과 기능에 미치는 효과 - 중학교 가정과 `소비 생활` 단원을 중심으로 -)

  • 정혜영;신상옥
    • Journal of Korean Home Economics Education Association
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    • v.13 no.3
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    • pp.147-160
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    • 2001
  • The purpose of this study is to suggest one of teaching methods through developing a new guideline of the teaching-learning applied the Problem-Based Learning which is derived from the Constructionism. And then we apply this guideline to the class of Home Economics. especially the unit of the Consumption life for investigating the effect of this method in the aspect of improving man-power development as a consumer The results of this study are summarized as follows : First. the class applied a new method of Problem-Based Learning turn out to be more improved in the aspect of consumer consciousness than the untested class going through explanation-based teaching(P< .01). This is, the former result more positive than the latter because the former could be given chances to handle faced problems in class. Second there is no significant difference between the tested class and the untested class in the aspect of consumer skill. This is the fact that the research was conducted in a short Period of time and that the researcher failed to show the suitable stimulation or materials. even though the researcher was well aware of what Problem-Based Learning is. Third students\` evaluation after the test indicates that the tested class not only increase interest in home economics but also help them to take an active Part in class as the main of the class. and that the learning atmosphere is improved and that the effect of learning was also enhanced. Although the aspect of consumer skill is not statistically significant. the result show that adolescents try to Practice their learning from the class in their life.

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