• Title/Summary/Keyword: 표면강화

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Design of Brushless Permanent Machine with Skewed Stator for Electrical Power Steering System (전동 조향 장치용 브러쉬리스 영구자석 전동기의 스테이터 스큐 설계)

  • Lee, Choong-Sung;Jung, Kyung-Tae;Hong, Jung-Pyo;Kim, Hae-Joong;Kim, Young-Kyun
    • Journal of the Korean Magnetics Society
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    • v.25 no.6
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    • pp.189-197
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    • 2015
  • As enforced the regulation of fuel efficiency, the electrification of automotive components in internal combustion vehicle has been applied instead of hydraulic pressure. A typical example of such parts is the EPS (electric power steering), and it is applied to most automotive at present. In electric power steering system, the core component is motor. The reduction of cogging torque and torque ripple is required to improve steering feeling and reduce NVH (Noise Vibration Harshness) in EPS. Generally the skewed design of stator or rotor is applied in order to reduce cogging torque and torque ripple. This paper propose the design and analysis methodology of Brusheless PMSM (Permanent Magnet Synchronous Motor) which is applied to skewed stator. The proposed methodology is as follows: First Intial Design PMSM with skewed stator for EPS, Second Optimal design using RSM (Response surface method), Third Performance Analysis such as Phase Back EMF, Inductance, Load torque using FEA (Finite Element Method). Finally, the reliability of proposed design methodology will be verified through the experiments of prototype sample.

A Study on Dual Structure in a Mirror - Revolve around the Relations between 'A Person Who sees' and 'A Person Who is Seen' - (거울(mirror)의 이중적인 구조에 대한 연구 - '보는 자'와 '보이는 자'의 관계를 중심으로 -)

  • Song, Dae-Sup;Lee, Eun-Young
    • Cartoon and Animation Studies
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    • s.41
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    • pp.429-454
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    • 2015
  • The starting point of this discussion resides in the 'eyes' of mirror in a sense of seeing the self reflected in a mirror. The meaning of mirror has been evolved over the centuries while strengthening its sense of identity by bringing up some questions for resemblance, reproduction, self-reflection and reality. A mirror has also extended its vision and provided with a range of images that the self can't have. In this regard, looking into a mirror has been a sustained focus of attention by creating another ostensible being of self-image. This shows the two sides of mirror, which reveals an ambiguous gap between substance and illusion. An excessive immersion in a reflected image in a mirror is intensified and expressed today. The eyes of mirror consisting of a complex dual structure show relations between a person who sees and a person who is seen, which draws a hazy line of demarcation between the subject and the object. This opens up the possibility of the world of chiasme, where you could face all the aspects being from the eyes of others. Furthermore, the meaning of the reflection in a mirror has formed a creative discourse as an enigmatic medium that creates a variety of 'eyes' in various forms of aesthetic expression like paintings and literature. I accordingly suggest that the 'eyes of mirror' is the ambiguous 'eyes of human being' reflected in two territories of the world. Therefore, I will present the historical development of the perspective on the mirror to take a concrete approach in which it opens up the reflective structure of resemblance through a series of examples projected onto the literary and artistic productions. This study will serve as ruminations on the fact that your life is being existent in 'chiasme' of mutual entanglement between the self and the world by investigating relations between a person who sees and a person who is seen, in other words, relations between the perceiving subject and the eyes of others reflected in a mirror.

Evaluation of Fiber Arrangement Condition of CF/PP Composites Using Electrical Resistance Measurement and Wettability (전기저항 평가법 및 접촉각을 이용한 CF/PP 복합재료 사출성형품 섬유 배열성 평가)

  • Kwon, Dong-Jun;Shin, Pyeong-Su;Kim, Jong-Hyun;Park, Joung-Man
    • Journal of Adhesion and Interface
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    • v.17 no.1
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    • pp.15-20
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    • 2016
  • Fiber arrangement was important for fiber reinforced thermoplastic composites using injection fabrication. In this work, fiber arrangement in CF/PP was investigated to use electrical resistance (ER) method during injection times. There were 3 types of injection products of CF/PP with different ER change ratio by fiber arrangement. High ER change ratio case of injection CF/PP products had better increased tensile strength. This reason was due to the fiber arrangement of CF/PP by injection. Fractured surface and contact angle of CF/PP products were used to evaluate for injection product quality. Uniform fiber arrangement of CF/PP by injection type exhibited the uniform heat condition of melted CF/PP. Steady thermal transfer effect occurred from melted CF/PP to steel injection mold. Steady thermal transfer effect of CF/PP was transmitted to high ER change ratio of mold. Ultimately, good condition CF/PP product by injection molding method could be predicted by using ER method.

Thermal and Mechanical Properties of Epoxy Composites Using Silica Powder (실리카 파우더를 이용한 에폭시 복합소재의 열적/기계적 특성)

  • Lee, Hye Ryeon;Song, JeeHye;Kim, Daeyeon;Lim, Choong-Sun;Seo, BongKuk
    • Journal of Adhesion and Interface
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    • v.17 no.1
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    • pp.7-14
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    • 2016
  • Epoxy composites with concentrations of 5-70 wt% of silica particles were prepared in order to improve mechanical property and poor thermal stability. The mechanical and thermal properties were investigated and compared to the corresponding properties of neat epoxy composite. Furthermore, the effects of silane compound treatment on silica particles were observed by the experimental results of the tensile strength, glass transition temperature, and thermal stability of epoxy composite. Tensile strength of epoxy composites was measured by universal testing machine (UTM) and after that, the structure and morphology analysis of epoxy nanocomposites were analyzed by field emission scanning electron microscope (FE-SEM) and energy dispersive spectroscopy (EDS). The increased solid content of CA0030 particle improved the tensile strength of epoxy/ modified composites to give 30-50 MPa. The thermal expansion coefficients (CTE) of neat epoxy resin and epoxy/silica composites measured with a thermomechanical analyzer (TMA) showed that the incorporation of silica particles was helpful to reduce the CTE of neat epoxy resin.

Tooth preparation design of dental laminate veneer: a review article (라미네이트 치아형성 디자인에 관한 문헌고찰)

  • Jo, Eun-Hye;Ko, Kyung-Ho;Park, Chan-Jin;Cho, Lee-Ra;Huh, Yoon-Hyuk
    • Journal of Dental Rehabilitation and Applied Science
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    • v.32 no.3
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    • pp.149-157
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    • 2016
  • Tooth preparation design is essential for successful laminate veneer treatment. Preservative tooth preparation limited on enamel, supra-margin advantageous for plaque control, and maintaining contact points known as a standard concept. However, the tooth preparation design has been the controversial issue. In biomechanical considerations, the incisal coverage should be decided on esthetic needs and necessity for the anterior guidance reconstruction. In occasion for sufficient enamel thickness, preparation can prolong to the palatal side but not recommended at palatal concavity. Elongation to contact point is selective option according to the cases. If an old resin restoration located at contact area, laminate veneer should cover over half area of that after surface treatment. The laminate veneer can be also selected at a partially discolored tooth root canal therapy (RCT) and at this occasion, the fiber-reinforced composite (FRC) posts are recommended.

Effects of a Herbal Composition (HemoHIM) on the Activation of Dendritic Cells (생약복합조성물(HemoHIM)의 수지상세포 활성화 효과)

  • Shin, Sung-Hae;Kim, Do-Soon;Kim, Sung-Ho;Jo, Sung-Kee;Byun, Mung-Woo;Yee, Sung-Tae
    • Journal of the Korean Society of Food Science and Nutrition
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    • v.35 no.10
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    • pp.1322-1328
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    • 2006
  • In our previous study, a novel herb mixture (HIM-I) of Angelica gigas radix, Cnidium officinale rhizoma, and Paeonia japonica radix was developed to protect= the intestinal and immune systems and to promote their recovery from radiation damage. A new herbal composition (HemoHIM) with the high immune modulating activity was developed from HIM-I. In the present study, we examined the effects of HemoHIM on the maturation process of murine bone marrow (BM)-derived dendritic cells (DC). BM cells were cultured in the presence of iL-4 and GM-CSF and the generated immature DC were stimulated with HemoHIM for 24 hours. HemoHIM significantly enhanced the expression of co-stimulatory molecules, CD80 and CD86, especially. The activation capacity of HemoHIM-treated DC was significantly higher than that of immature DC, as analyzed by IL-2 and $IFN-\gamma$ production and proliferation of the responding T cells in the co-culture with allogeneic T cells. The antigen-presenting capacity of HemoHIN-treated DC was also increased by the co-culture with OVA-specific T cells (HS-1), as analyzed by IL-2 and $IFN-\gamma$ production and the proliferation. These results indicate that HemoHIM causes the maturation and ;Activation of DC, which may be a part of mechanisms of immunomodulation by HemoHIM.

Simultaneous Concentration and Determination of Several Trace Elements in Sea Water by Ce(OH)$_3$ Coprecipitation (Ce(OH)$_3$의 공침부선에 의한 해주중 몇 가지 미량원소의 동시 농축 및 정량)

  • Woo-Sik Sung;Hee-Seon Choi;Young-Sang Kim
    • Journal of the Korean Chemical Society
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    • v.37 no.3
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    • pp.327-333
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    • 1993
  • A method was developed for the determination of trace elements in seawater by precipitate flotation preconcentration and subsequent flame atomic absorption detection. In order to quantitatively coprecipitate trace ions such as Cd(II), CuI(II), Fe(III), Mn(II), Pb(II) and Pd(II), 2.0 ml of 1.0M cerium(III) solution was added to 1.0l of seawater and the pH was adjusted to 9.5 with 5.0 M sodium hydroxide solution while stirring with a magnetic stirrer. The precipitate was floated with the aid of surfactant solution (1.0 ml of 0.3% sodium oleate) by bubbling nitrogen gas through a porous (No. 4) fritted glass disk. The floats was collected in a small Erlenmeyer flask by suction. The washed precipitate was dissolved in 8.0 M nitric acid and marked with deionized water in the volumetric flask of 10.0 ml. The analyte was determined by measuring the atomic absorbances in 100-fold concentrated solution. Above all analytes in Kangnung (East Sea) and Kanghwado (West Sea) sea waters were found to be under the detection limit of this method. The recoveries of over 92% for all analytes spiked into seawater samples showed that this method was applicable to the analysis of real seawater.

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A Study on the 'fragmentation' trend of modern film montage (현대영화 몽타주의 '파편화(fragmentation)' 경향 연구)

  • LEE, Jiyoung
    • Trans-
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    • v.3
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    • pp.29-53
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    • 2017
  • The film scholar Vincent Amiel divides into three types of montage through his book The Aesthetics of Montage ; Montage narratif, Montage discursif, and Montage decorrespondances. These three categories are the concept that encompasses the aesthetic class to which most movies belong. Early films pursued the essential and basic functions of editing, which tend to be modified in the direction of enhancing the director's goals over time. In this way, "Expressive Montage" is one of most important concepts of montage, not as a 'methodology' that combines narrative but as a 'purpose'. In the montage stage, the expressive montage work is done through three steps of decision. The process of 'combining' to combine the selected films in a certain order, after the process of 'selection' which selects only necessary parts of the rush film, and 'connection' to determine the scene connection considering the duration of the shot. The connection is the final stage of the montage. There are exceptions, of course. When fiction films of classical narratives use close-ups, or when using models or objects of neutered animals, the film induces the tendency of a "montage decorrespondances" rather than a "montage narratif" or "montage discursif". This study attempts to analyze the tendency of montage of works with 'uncertain connection' through 'collage' used by close-ups and montage decorrespondances as 'fragmentation tendency of modern films'. The fragmentation of the montage in contemporary film breaks the continuous and structural nature of the film, and confuses the narration structure that is visible on the surface of the film. The tendency of the fragmentation of the montage, which started from this close-up, seems to give an answer to the extensibility of the modern image.

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An Experimental Study for Flexure/Shear Failure Behavior of Composite Beam with GFRP Plank Used As a Permanent Formwork and Cast-in-place High Strength Concrete (영구거푸집으로 사용한 유리섬유 FRP 판과 현장타설 고강도콘크리트로 이루어진 합성보의 휨/전단파괴거동에 관한 실험적 연구)

  • Yoo, Seung-Woon
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.16 no.6
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    • pp.4245-4252
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    • 2015
  • In this study, an experiment which utilized glass fiber reinforced polymer(GFRP) plank as the permanent formwork of cast-in-place high strength concrete structures was performed. The GFRP plank currently being produced has smooth surface so that it causes problems in behavior with concrete. Therefore, this research analyzed the flexure/shear failure behavior of composite beams, which used GFRP plank as its permanent formwork and has short shear span ratio, by setting the sand coated at GFRP bottom surface, the perforation and interval of the GFRP plank web, and the width of the top flange as the experimental variables. As a result of the experiments for effectiveness of sand attachment in case of not perforated web, approximately 47% higher ultimate load value was obtained when the sand was coated than not coated case and bending/shear failure mode was observed. For effectiveness of perforation and interval of gap, approximately 24% higher maximum load value was seen when interval of the perforation gap was short and the fine aggregate was not coated, and approximately 25% lower value was observed when the perforation gap was not dense on the coated specimen. For effectiveness of top flange breadth, the ultimate load value was approximately 17% higher in case of 40mm than 20mm width.

Engraftment of Intraperitoneally Injected Bone Marrow Cells to Newborn Mice Injected with an Angiogenesis Inhibitor (혈관생성 억제제를 주사한 마우스 모델에서의 골수 세포의 복강 내 주입 후 생착)

  • Cho, Su-Jin;Ju, Sun-Young;Woo, So-Youn;Kang, Hyoung-Jin;Ahn, Hyo-Seop;Ryu, Kyung-Ha;Park, Eun-Ae
    • Neonatal Medicine
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    • v.15 no.1
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    • pp.22-31
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    • 2008
  • Purpose : Bronchopulmonary dysplasia (BPD) is characterized by arrested vascular and alveolar growth in the premature lung. Considering the consequences of arrested lung growth, the idea of administering bone marrow cells to enhance the inborn repair mechanism is promising as this may reduce the morbidity and mortality of BPD. We followed enhanced green fluorescent protein (EGFP)-labeled bone marrow cells (BMC) injected intraperitoneally into non-EGFP mice in order to determine their fate after transplantation. Methods : An angiogenesis inhibitor, SU1498, was injected subcutaneously on day 3 in non-EGFP C57BL/6 newborn mice to create a model of arrested alveolar development. On the following day, $1{\times}10^6$ BMCs isolated from major histocompatibility complex (MHC)- matched syngenic EGFP mice were injected intraperitoneally to non-EGFP BPD mice. Morphometric analysis, immunostaining, and confocal microscopy were performed to determine the fate of EGFP-positive stem cells in the injured lung. Results : SU1498 injection reduced alveolar surface area and mean alveolar volume in newborn mice. BMC injection resulted in recovery of lung structure comparable to controls. EGFP-positive BMCs were identified in the lungs of the recipient mice after intraperitoneal injection. The injected EGFP cells were co-stained with endothelial and epithelial cells of the developing lung as determined by confocal microscopy. Conclusion : Our results illustrated that EGFP-positive BMCs engrafted and trans-differentiated into epithelial and endothelial cells after intraperitoneal injection in a mouse model of arrested alveolar development.