• Title/Summary/Keyword: Pohang area

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Control of secondary electron emission coefficient with microstructural change of polycrystalline MgO films

  • Yu, Hak-Ki;Lee, Jong-Lam;Park, Eung-Chul;Kim, Jae-Sung;Ryu, Jae-Hwa
    • 한국정보디스플레이학회:학술대회논문집
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    • 2008.10a
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    • pp.1445-1447
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    • 2008
  • Micro crystal structure of polycrystalline MgO film is controlled by adjusting the energy of particles arrived at the substrate during deposition. The change of crystal structure affects on the total area of (200) surface where the oxygen vacancies are formed easily, resulting in the change of secondary electron emission (SEE) coefficient($\gamma$).

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High Mobility Single-Crystal OTFTs based on TIPS Anthracene Derivatives

  • Park, Jong-Won;Chung, Dae-Sung;Kang, Dong-Min;Kim, Yun-Hi;Park, Chan-Eon;Kwon, Soon-Ki
    • 한국정보디스플레이학회:학술대회논문집
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    • 2008.10a
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    • pp.841-843
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    • 2008
  • We elucidated a way to increase the mobility of $\pi$-stacked materials by comparing various single-crystal OFETs. A high field-effect mobility (of $3.7\;cm^2/Vs$) was obtained by increasing the effective $\pi$-stacking area and decreasing the $\pi$-stacking distance.

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TIPS Anthracene Derivatives for Solution Process OTFT Materials : Large $\pi$-stacking area and Easy Crystallizability

  • Park, Jong-Won;Chung, Dae-Sung;Park, Jong-Hwa;Kim, Yun-Hi;Shim, Hong-Ku;Park, Chan-Eon;Kwon, Soon-Ki
    • 한국정보디스플레이학회:학술대회논문집
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    • 2008.10a
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    • pp.98-100
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    • 2008
  • A series of new channel materials using triisopropylsilylethynyl anthracene(TIPSAN) derivatives are synthesized by well known reaction. The TIPSAN derivatives exhibit an excellent field-effect mobility with hole mobility as high as 0.1 cm2V-1s-1 by solution-process and slip stack structure of core and end groups with short $\pi-\pi$ stacking distance of $3.525{\sim}3.485\;{\AA}$ by single crystal structures.

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Evolution and Design Principles of the Diverse Chloroplast Transit Peptides

  • Lee, Dong Wook;Hwang, Inhwan
    • Molecules and Cells
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    • v.41 no.3
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    • pp.161-167
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    • 2018
  • Chloroplasts are present in organisms belonging to the kingdom Plantae. These organelles are thought to have originated from photosynthetic cyanobacteria through endosymbiosis. During endosymbiosis, most cyanobacterial genes were transferred to the host nucleus. Therefore, most chloroplast proteins became encoded in the nuclear genome and must return to the chloroplast after translation. The N-terminal cleavable transit peptide (TP) is necessary and sufficient for the import of nucleus-encoded interior chloroplast proteins. Over the past decade, extensive research on the TP has revealed many important characteristic features of TPs. These studies have also shed light on the question of how the many diverse TPs could have evolved to target specific proteins to the chloroplast. In this review, we summarize the characteristic features of TPs. We also highlight recent advances in our understanding of TP evolution and provide future perspectives about this important research area.

Design of a Built-In Current Sensor for IDDQ Testing (IDDQ 테스팅을 위한 내장형 전류 감지 회로 설계)

  • Kim, Jeong-Beom;Hong, Sung-Je;Kim, Jong
    • Journal of the Korean Institute of Telematics and Electronics C
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    • v.34C no.8
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    • pp.49-63
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    • 1997
  • This paper presents a current sensor that detects defects in CMOS integrated circuits using the current testing technique. The current sensor is built in a CMOS integrated circuit to test an abnormal current. The proposed circuit has a very small impact on the performance of the circuit under test during the normal mode. In the testing mode, the proposed circuit detects the abnormal current caused by permanent manufacturing defects and determines whether the circuit under test is defect-free or not. The proposed current sensor is simple and requires no external voltage and current sources. Hence, the circuit has less area and performance degradation, and is more efficient than any previous works. The validity and effectiveness are verified through the HSPICE simulation on circuits with defects.

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The Elders' General Quality of Life and Oral Health-related Quality of Life (일부 노인의 일반적 삶의 질과 구강건강관련 삶의 질에 관한 연구)

  • Bae, Ji-Young
    • Journal of Korean Clinical Health Science
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    • v.3 no.4
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    • pp.466-475
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    • 2015
  • Purpose. The purpose of this study was conducted to identify the elders' general quality of life and oral health-related quality of life. Method. Questionnaire survey was conducted on 241 elders' living in Pohang area from August to September 2014. The results were obtained from t-test, one-way ANOVA analysis, pearson correlation coefficients and multiple regression analysis. Results. Oral health status had significant correlations with gender, age, education, income, drink and hypertension. Oral health-related quality of life showed the highest relationships with age; oral health status and general quality of life showed the highest relationships with monthly income; and, age and education period also showed influence on general quality of life. Conclusions. Therefore, it is required to strengthen oral health improvement program and oral health education for improvement of elders' quality of life.

Phenomenological Combustion Modeling of a Direct Injection Diesel Engine with In-Cylinder Flow Effects

  • Im, Yong-H.;Huh, Kang-Y.
    • Journal of Mechanical Science and Technology
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    • v.14 no.5
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    • pp.569-581
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    • 2000
  • A cycle simulation program is developed and its predictions are compared with the test bed measurements of a direct injection (DI) diesel engine. It is based on the mass and energy conservation equations with phenomenological models for diesel combustion. Two modeling approaches for combustion have been tested; a multi-zone model by Hiroyasu et al (1976) and the other one coupled with an in-cylinder flow model. The results of the two combustion models are compared with the measured imep, pressure trace and NOx and soot emissions over a range of the engine loads and speeds. A parametric study is performed for the fuel injection timing and pressure, the swirl ratio, and the squish area. The calculation results agree with the measured data, and with intuitive understanding of the general operating characteristics of a DI diesel engine.

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A Schematic Design Study for Jangsung High School in Pohang (포항(浦港) 장성고등학교(長城高等學校) 계획설계(計劃設計) 연구(硏究))

  • Yim, Chang-Bok;Yang, Kwan-Mok
    • Journal of the Korean Institute of Educational Facilities
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    • v.9 no.4
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    • pp.5-13
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    • 2002
  • This paper aims to analyse design conditions and propose schematic design for Jangsung High School in Pohang. As for site conditions, it has the size of $14,900m^2$ and a rather flat condition near to the ocean East Sea. And the area is under development with land subdivision method expecting high density housing around it. As a program, Education Facilities Bureau required to provide 36 classes and supporting facilities. To design the schemes, we followed the 7th education policy guidelines. During the design development stage, 3 alternatives are suggested as in the paper. However, staffs of Education Bureau and teachers favoured and selected our scheme, which gives symbolic image, as a new high school education environment.

Ozone Generation Characteristics of Silent Discharge Type Ozonizer with Varying Discharge Area (무성방전형 오존발생기의 전극면적 변화에 따른 오존생성특성)

  • Lee, S.K.;Chun, B.J.;Park, Y.K.;Lee, K.S.;Song, H.J.;Lee, D.H.;Kim, Y.H.;Kim, G.Y.
    • Proceedings of the KIEE Conference
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    • 2002.07c
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    • pp.1775-1778
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    • 2002
  • 무성방전을 이용한 오존발생기에서 오존생성에 영향을 미치는 인자로는 원료가스의 온도, 습도, 유량, 방전전극의 재질과 형태, 전원의 형태 등 다양하다. 본 연구에서는 전극의 면적변화에 의한 오존생성특성을 살펴보았다. 그 결과, 방전전극의 면적이 넓어짐에 따라 더 많은 전력의 인가가 가능하여 대용량의 오존발생기의 제작이 가능하며, 또한, 동일한 전력을 인가하는 경우에도 전극면적의 증대가 오존발생특성의 향상을 가져옴을 알 수 있었다.

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Representative Volume Element Analysis of Fluid-Structure Interaction Effect on Graphite Powder Based Active Material for Lithium-Ion Batteries

  • Yun, Jin Chul;Park, Seong Jin
    • Journal of Powder Materials
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    • v.24 no.1
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    • pp.17-23
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    • 2017
  • In this study, a finite element analysis approach is proposed to predict the fluid-structure interaction behavior of active materials for lithium-ion batteries (LIBs), which are mainly composed of graphite powder. The porous matrix of graphite powder saturated with fluid electrolyte is considered a representative volume element (RVE) model. Three different RVE models are proposed to consider the uncertainty of the powder shape and the porosity. P-wave modulus from RVE solutions are analyzed based on the microstructure and the interaction between the fluid and the graphite powder matrix. From the results, it is found that the large surface area of the active material results in low mechanical properties of LIB, which leads to poor structural durability when subjected to dynamic loads. The results obtained in this study provide useful information for predicting the mechanical safety of a battery pack.