• Title/Summary/Keyword: Stabilization control

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A Study on the Characteristics of Information Design in Multimedia Design (멀티미디어디자인에서 정보디자인 특성에 관한 연구)

  • 류시천
    • Archives of design research
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    • v.17 no.1
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    • pp.63-76
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    • 2004
  • Although information design principles had originated from the graphic design field including publishing design in 1970s, information design have taken one of the most important positions in multimedia design fields as the present since Richard Saul Wurmn started his researches on information design and its practical application on internet environments. However, relatively little researches have been performed for building identity of information design in multimedia design fields so far and moreover in some cases, information design is likely to be narrowly viewed as 'the representation of a piece of information and its visualization' which was defined in traditional graphic design field. This research circumstance leads the study to investigate characteristics of information design in current multimedia design with contingent perspective which is compared to the traditional information design. The study results suggest 5 characteristics of information design including 'suggesting context & finding out information hierarchy', 'access of integrated consideration & share of information control', 'using of multi-dimensional media & content first', 'stabilization of information quality & combinational understanding of meaning', 'bilateral information representation & user's knowledge expansion'. Future researches, based on the results of the study, are expected to be expanded to a degree with argument for inter-dependent and/or exclusive characteristics of adjacent fields of information design such as interface design, interaction design and experience design.

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A Study on th Quality Stabilization of Iron Oxide (산화철의 품질 안정화)

  • 변태봉;한기현;김형석;배우현
    • Resources Recycling
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    • v.7 no.4
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    • pp.55-63
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    • 1998
  • The main purpose of the present study is to reduce quality variation of iron oxide for soft ferrite produced at hydrochloric acid facility )HAF) in a cold rolled mill factory. We investigated the factor of iron oxide quality variation, the operating condition of hydrochloric acid facility and the iron oxide quality with the production lot. Based on this information, we liad developed proper working plan for the diminution of iron oxide quality variation. To reduce iron oxide quality variation, the first priority is to control the picking steels, which seriously affect iron oxide quality variation, and then to separate generated waste acid. theretore, it was possible to reduce iron oxide quality variation with the proper operation of various kinds of waste acid tanks. We could produce iron oxide below 20 ppm SiO$_{2}$ content variation by operation after separation waste acid generated at TCM line.

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Development and Application of Operation Methods of Battery Energy Storage System for Frequency Regulation (주파수조정용 배터리 에너지저장장치 운전방법의 개발과 적용)

  • Lim, Geon-Pyo;Park, Doo-Yong
    • The Transactions of the Korean Institute of Electrical Engineers P
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    • v.64 no.2
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    • pp.57-61
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    • 2015
  • Current research and development efforts and other projects for energy storage systems (ESS) have recently been gaining attention. This is due to the many applications where ESS, particularly batteries, can be used. Among these are peak shaving, frequency regulation, and stabilization of renewable energy output. KEPCO has completed the construction and demonstration of a 4-MW battery energy storage system (BESS) located in Jeju City to verify its practicability in the power grid. KEPCO Research Institute has also been developing technology for the commercialization of BESS, and has been conducting a trial run of a 52-MW ESS (28MW + 24MW of Seo-Anseong and Shin-Yongin substations) constructed in 2014 for frequency regulation. This paper discusses the development of operation methods, as well as an operation user interface, for the safe operation and monitoring of BESS used for frequency regulation in a power system. Included are operation and simulation methods for various normal and transient frequency situations that can be experienced by a power system. Also discussed are the results obtained after applying these methods to the 4-MW BESS and the 52-MW ESS, both used for frequency regulation. The technology in this paper will be applied to 500MW ESS for frequency regulation of KEPCO by 2017. It is expected that this technology helps a safe and reliable operation and control of ESS for frequency regulation through its continuous upgrade.

Effects of PVA and CMC addition on Rheological Characteristics and Curtain Stability of GCC Based Curtain Coating Colors (PVA와 CMC 첨가가 커튼 코팅용 GCC 도공액의 유변 특성 및 커튼 안정성에 미치는 영향)

  • Choi, Eun-Heui;Kim, Chae-Hoon;Lee, Hak-Lae
    • Journal of Korea Technical Association of The Pulp and Paper Industry
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    • v.42 no.5
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    • pp.74-82
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    • 2010
  • Curtain stability without curtain contraction is critical for a successful operation in curtain coating, and this can be influenced by the change in particle dynamics and rheological properties of coating colors. In this study, polyvinyl alcohol (PVA) and carboxymethyl cellulose (CMC) were added to control the rheology of GCC based curtain coating colors. Surface tension was increased slightly with increasing content of cobinder. Shear-thinning of viscosity was more pronounced for the CMC containing GCC coating colors. Complex modulus decreased when small amount of PVA was used as a cobinder, but it increased in other coating colors. Extensional viscosity was increased with increasing of the cobinder content, but CMC was more effective. Results indicate that pigment interaction with PVA is different from that with CMC. Dispersibility of coating colors was improved due to steric stabilization when small amounts of PVA was used, but flocculation occurred by bridging when the amount of PVA was increased. Dispersibility of coating colors was improved when small amount of CMC was added, while flocculation was observed by depletion effect when the concentration of CMC was increased in coating colors. Addition of cobinders at proper levels gave positive effects both in rheological properties and curtain stability. On the other hand, excessive amount of cobinders caused particle flocculation and this resulted in rheological and curtain stablity problems.

A Study of Thermo-rheological Behaviour from Long Term Responses of Solid Composite Propellant (고체 추진제 장시간 물성거동 반응 연구)

  • Ryu, Taeha;Kim, Nakhyun;Khil, Taeock;Choi, Yongkyu
    • Journal of the Korean Society of Propulsion Engineers
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    • v.21 no.1
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    • pp.8-16
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    • 2017
  • Structural integrity of solid rocket depends on the residual reactions between constituents of its composition(post cure, migration etc.), the oxygen(or anti-oxydent) in the free volume and humidity (desiccant) under the perfect sealed condition. Mechanical Properties of composite solid propellant arising from those factors are very complex. Moreover the propulsion are faced with thermal loads from diurnal & seasonal cycle till firing. In this study, the fast evaluation method of long term mechanical properties is suggested based on Thermo-Rheological Simplicity from curing oven to cool-down stage in view point of thermal stabilization. For this subject, endurance tester having temperature control capability are devised. From the results from incremental load and strain, non-linear characteristics are discussed.

Synthesis of Polymers in Supercritical Carbon Dioxide (초임계 유체를 이용한 고분자 합성 연구)

  • Lee, Hyun-Suk;Kim, Jin-Woong
    • Journal of the Society of Cosmetic Scientists of Korea
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    • v.36 no.1
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    • pp.17-32
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    • 2010
  • This review shows the design and the development of new $CO_2$-soluble hydrocarbon copolymers which can be used as effective stabilizers for successful dispersion polymerizations of bio-compatible materials in supercritical carbon dioxide ($scCO_2$). The basic concepts of supercritical fluid including its solvent properties and applications in polymer synthesis are described. We report the facile synthesis of highly soluble hydrocarbon based copolymers, prepared with good control via controlled free radical polymerization from readily accessible and commercially available monomers. The phase behaviour of these materials was monitored in pure $CO_2$ to investigate how the molecular weights and the composition of the copolymers affect their solubility in $CO_2$. Their activity as a stabilizer was then tested in dispersion polymerization of N-vinyl pyrrolidone in $CO_2$ at various reaction conditions to identify the key parameters required for a successful dispersion stabilization of growing PVP particles. Some prospective potentials of this research which can be applied in developing new polymer materials in an environmentally-friendly fashion for use in cosmetics are also discussed.

Biphasic Regulation of Mitogen-Activated Protein Kinase Phosphatase 3 in Hypoxic Colon Cancer Cells

  • Kim, Hong Seok;Kang, Yun Hee;Lee, Jisu;Han, Seung Ro;Kim, Da Bin;Ko, Haeun;Park, Seyoun;Lee, Myung-Shin
    • Molecules and Cells
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    • v.44 no.10
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    • pp.710-722
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    • 2021
  • Hypoxia, or low oxygen tension, is a hallmark of the tumor microenvironment. The hypoxia-inducible factor-1α (HIF-1α) subunit plays a critical role in the adaptive cellular response of hypoxic tumor cells to low oxygen tension by activating gene-expression programs that control cancer cell metabolism, angiogenesis, and therapy resistance. Phosphorylation is involved in the stabilization and regulation of HIF-1α transcriptional activity. HIF-1α is activated by several factors, including the mitogen-activated protein kinase (MAPK) superfamily. MAPK phosphatase 3 (MKP-3) is a cytoplasmic dual-specificity phosphatase specific for extracellular signal-regulated kinase 1/2 (Erk1/2). Recent evidence indicates that hypoxia increases the endogenous levels of both MKP-3 mRNA and protein. However, its role in the response of cells to hypoxia is poorly understood. Herein, we demonstrated that small-interfering RNA (siRNA)-mediated knockdown of MKP-3 enhanced HIF-1α (not HIF-2α) levels. Conversely, MKP-3 overexpression suppressed HIF-1α (not HIF-2α) levels, as well as the expression levels of hypoxia-responsive genes (LDHA, CA9, GLUT-1, and VEGF), in hypoxic colon cancer cells. These findings indicated that MKP-3, induced by HIF-1α in hypoxia, negatively regulates HIF-1α protein levels and hypoxia-responsive genes. However, we also found that long-term hypoxia (>12 h) induced proteasomal degradation of MKP-3 in a lactic acid-dependent manner. Taken together, MKP-3 expression is modulated by the hypoxic conditions prevailing in colon cancer, and plays a role in cellular adaptation to tumor hypoxia and tumor progression. Thus, MKP-3 may serve as a potential therapeutic target for colon cancer treatment.

Organic amendment-driven removal and speciation of metals using wormwood in two contrasting soils near an abandoned copper mine

  • Ro, Hee-Myong;Choi, Hyo-Jung;Yun, Seok-In;Park, Ji-Suk
    • Horticulture, Environment, and Biotechnology : HEB
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    • v.59 no.6
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    • pp.775-786
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    • 2018
  • To test the hypothesis that humic acid (HA), anaerobically digested pig slurry filtrate (APS), and their combination would differently affect the chemical speciation and extractability of metals (cadmium, copper, and zinc) and their uptake by plants, we conducted a pot experiment using wormwood in two texturally contrasting soils (sandy loam and clay loam) collected from a field near an abandoned Cu mine. Four treatments were laid out: HA at $ 23.5g\;kg^{-1}$ (HA), APS at $330mL\;kg^{-1}$ (APS), HA at $ 23.5g\;kg^{-1}$ and APS at $330mL\;kg^{-1}$ (HA + APS), and a control. Each treatment affected the chemical speciation and mobility of the metals, and thereby resulting in variable patterns of plant biomass yield and metal uptake. The APS supported plant growth by increasing nutrient availability. HA supported or hindered plant growth by impacting the soil's water and nutrient retention capacity and aeration, in a soil texture-dependent manner, while consistently enhancing the immobilization of heavy metals. Temporal increases in whole-plant dry matter yield and metal accumulation suggested that the plants were capable of metal hyperaccumulation. The results were discussed in terms of the mobility of metals and plant growth and corroborated by the $^{15}N$ recovery of soil- and plant-N pools under H and HS treatments. Therefore, for effective phytoremediation of polluted soils, an appropriate combination of plant growth promoters (APS) and chelating agents (HA) should be predetermined at the site where chemical stabilization of pollutants is desired.

Central Venous Catheterization before Versus after Computed Tomography in Hemodynamically Unstable Patients with Major Blunt Trauma: Clinical Characteristics and Factors for Decision Making

  • Kim, Ji Hun;Ha, Sang Ook;Park, Young Sun;Yi, Jeong Hyeon;Hur, Sun Beom;Lee, Ki Ho
    • Journal of Trauma and Injury
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    • v.31 no.3
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    • pp.135-142
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    • 2018
  • Purpose: When hemodynamically unstable patients with blunt major trauma arrive at the emergency department (ED), the safety of performing early whole-body computed tomography (WBCT) is concerning. Some clinicians perform central venous catheterization (CVC) before WBCT (pre-computed tomography [CT] group) for hemodynamic stabilization. However, as no study has reported the factors affecting this decision, we compared clinical characteristics and outcomes of the pre- and post-CT groups and determined factors affecting this decision. Methods: This retrospective study included 70 hemodynamically unstable patients with chest or/and abdominal blunt injury who underwent WBCT and CVC between March 2013 and November 2017. Results: Univariate analysis revealed that the injury severity score, intubation, pulse pressure, focused assessment with sonography in trauma positivity score, and pH were different between the pre-CT (34 patients, 48.6%) and post-CT (all, p<0.05) groups. Multivariate analysis revealed that injury severity score (ISS) and intubation were factors affecting the decision to perform CVC before CT (p=0.003 and p=0.043). Regarding clinical outcomes, the interval from ED arrival to CT (p=0.011) and definite bleeding control (p=0.038), and hospital and intensive care unit lengths of stay (p=0.018 and p=0.053) were longer in the pre-CT group than in the post-CT group. Although not significant, the pre-CT group had lower survival rates at 24 hours and 28 days than the post-CT group (p=0.168 and p=0.226). Conclusions: Clinicians have a tendency to perform CVC before CT in patients with blunt major trauma and high ISS and intubation.

Pelvic Compression Using a Compression Belt and Non-elastic Taping on Trunk and Hip Extensor Muscle Activity during Prone Hip Extension: A Comparative Study of Experienced and Non-experienced Low Back Pain Group (압박 벨트와 비탄력 테이프를 이용한 골반압박이 엎드려 고관절 신전 시 체간과 고관절 신전근의 근 작용에 미치는 영향: 요통 경험군과 요통 비경험군 비교 연구)

  • Park, So-hyun;Kim, Suhn-yeop
    • The Journal of Korean Academy of Orthopedic Manual Physical Therapy
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    • v.27 no.2
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    • pp.27-36
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    • 2021
  • Background : Prone hip extension (PHE) is commonly used for exercises and tests in patients with low back pain. Previous studies have shown that pelvic compression belts (PCB) and non-elastic taping (NET) contribute greatly to improvements in lumbopelvic stability. This study aimed to compare the effect of two lumbopelvic stability methods such as PCB and NET on the trunk and hip extensor muscle activities during PHE tests. Methods: Subjects who experienced low back pain (low back pain group, LBPG; n=20) and those who did not experience low back pain (non-LBPG; n=20) participated in this study. The subjects were instructed to perform PHE with and without a PCB and NET. PHE tests were performed in the condition wherein the two stabilization methods were applied, and the actions of the muscles at that time were measured using surface electromyography (EMG). EMG data were collected from the hamstring, gluteus maximus, erector spine (ES), and multifidus (MF) muscles. The data were collected three times for 5 s with a 1-min rest between each of the three sets. Results: In the LBPG, EMG of the ES muscle was significantly reduced when NET or a PCB was applied (p<.05). There was no difference in the change in the ES muscle activity when NET and a PCB were applied. The ratio of MF/ES muscleactivity showed a significant increase in the LBPG with NET (p<.05). Conclusion: Both NET and PCB applied to subjects who experienced low back pain significantly reduced the ES muscle activity during PHE exercises and helped control the balance of the superficial and deep trunk extensor muscles.