• Title/Summary/Keyword: Memory school

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Manufacturing of Cu-26.7Zn-4.05Al(wt.%) Shape Memory Alloy Using Spark Plasma Sintering (Spark Plasma Sintering을 이용한 Cu-26.7Zn-4.05Al(wt.%) 형상기억합금의 제조)

  • Park, No-Jin;Lee, In-Sung;Cho, Kyeong-Sik;Kim, Sung-Jin
    • Korean Journal of Materials Research
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    • v.13 no.6
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    • pp.352-359
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    • 2003
  • In order to control the grain size, the spark plasma sintering technique is applied for the manufacturing of Cu-26.7Al-4.05AI(wt.%) shape memory alloy with pure Cu, Zn, and Al element powders. The sintering processes were carried out under different atmospheres. The sintered bodies were denser under Ar or Ar+4%$H_2$gas atmosphere than under vacuum. With use of small-sized powders, a very small average grain size of 2∼3 $\mu\textrm{m}$ was obtained, but the single phase was not formed. With the large-sized powders the single austenitic phase was observed with the average grain size of $70∼72\mu\textrm{m}$. When the different size of raw powders was mixed, it is confirmed that the average grain size of the manufactured alloys was 15 $\mu\textrm{m}$ with single austenitic phase, but the distribution of grain size was not uniform.

Electrical Properties of Metal-Ferroelectric-Insulator-Semiconductor Field-Effect Transistor Using an Au/$(Bi,La)_4Ti_3O_{12}/LaZrO_x$/Si Structure

  • Jeon, Ho-Seung;Lee, Gwang-Geun;Kim, Joo-Nam;Park, Byung-Eun;Choi, Yun-Soo
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 2007.11a
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    • pp.171-172
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    • 2007
  • We fabricated the metal-ferroelectric-insulator-semiconductor filed-effect transistors (MFIS-FETs) using the $(Bi,La)_4Ti_3O_{12}\;and\;LaZrO_x$ thin films. The $LaZrO_x$ thin film had a equivalent oxide thickness (EOT) value of 8.7 nm. From the capacitance-voltage (C-V) measurements for an Au/$(Bi,La)_4Ti_3O_{12}/LaZrO_x$/Si MFIS capacitor, a hysteric shift with a clockwise direction was observed and the memory window width was about 1.4 V for the bias voltage sweeping of ${\pm}9V$. From drain current-gate voltage $(I_D-V_G)$ characteristics of the fabricated Fe-FETs, the obtained threshold voltage shift (memory window) was about 1 V due to ferroelectric nature of BLT film. The drain current-drain voltage $(I_D-V_D)$ characteristics of the fabricated Fe-FETs showed typical n-channel FETs current-voltage characteristics.

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A Study on Concept of Chongmyeong and Chongmyeong-tang Based on Visual, Auditory Sense and Brain Science Based on Complex System (시각, 청각과 복잡계 기반 뇌과학에 근거한 총명개념과 총명탕 연구)

  • Jeon, Hong-Seok;Baek, Kyu-Tae;Jeon, Kyung-Bae;Kwon, Kang
    • The Journal of Korean Medicine Ophthalmology and Otolaryngology and Dermatology
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    • v.30 no.4
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    • pp.104-130
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    • 2017
  • Objectives : This study was designed to signpost the study of brain, intelligence and memory, while interpreting the concept of 'Chongmyeong(聰明)' neotrically and linking it to the clinic of Korean medicine. Methods : In this paper, the meaning of the word 'Chongmyeong(聰明)' is divided into two parts, intelligence and memory. We also explored the relationship between brain science and 'Chongmyeong(聰明)' based on complex system theory, cognitive science and embodied cognition. Results : Through the process of refining the concept of 'Chongmyeong(聰明)' neoterically, we proposed the new method to understand the concept of 'Chongmyeong(聰明)'. Conclusions : The concept of 'Chongmyeong(聰明)' should be interpreted not as a reductionistic viewpoint of brain science but as a viewpoint of brain science based on visual and auditory system and complex system. Human cognition is physically embodied in the environment, from the viewpoint of embodied cognition that it is constituted and formed in an interactive context with society and culture connected with the environment.

Electrical characteristics of poly-Si NVM by using the MIC as the active layer

  • Cho, Jae-Hyun;Nguyen, Thanh Nga;Jung, Sung-Wook;Yi, Jun-Sin
    • Proceedings of the Korean Vacuum Society Conference
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    • 2010.02a
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    • pp.151-151
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    • 2010
  • In this paper, the electrically properties of nonvolatile memory (NVM) using multi-stacks gate insulators of oxide-nitride-oxynitride (ONOn) and active layer of the low temperature polycrystalline silicon (LTPS) were investigated. From hydrogenated amorphous silicon (a-Si:H), the LTPS thin films with high crystalline fraction of 96% and low surface's roughness of 1.28 nm were fabricated by the metal induced crystallization (MIC) with annealing conditions of $650^{\circ}C$ for 5 hours on glass substrates. The LTPS thin film transistor (TFT) or the NVM obtains a field effect mobility of ($\mu_{FE}$) $10\;cm^2/V{\cdot}s$, threshold voltage ($V_{TH}$) of -3.5V. The results demonstrated that the NVM has a memory window of 1.6 V with a programming and erasing (P/E) voltage of -14 V and 14 V in 1 ms. Moreover, retention properties of the memory was determined exceed 80% after 10 years. Therefore, the LTPS fabricated by the MIC became a potential material for NVM application which employed for the system integration of the panel display.

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Vaccine Strategy That Enhances the Protective Efficacy of Systemic Immunization by Establishing Lung-Resident Memory CD8 T Cells Against Influenza Infection

  • Hyun-Jung Kong;Youngwon Choi;Eun-Ah Kim;Jun Chang
    • IMMUNE NETWORK
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    • v.23 no.4
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    • pp.32.1-32.15
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    • 2023
  • Most influenza vaccines currently in use target the highly variable hemagglutinin protein to induce neutralizing antibodies and therefore require yearly reformulation. T cell-based universal influenza vaccines focus on eliciting broadly cross-reactive T-cell responses, especially the tissue-resident memory T cell (TRM) population in the respiratory tract, providing superior protection to circulating memory T cells. This study demonstrated that intramuscular (i.m.) administration of the adenovirus-based vaccine expressing influenza virus nucleoprotein (rAd/NP) elicited weak CD8 TRM responses in the lungs and airways, and yielded poor protection against lethal influenza virus challenge. However, a novel "prime-and-deploy" strategy that combines i.m. vaccination of rAd/NP with subsequent intranasal administration of an empty adenovector induced strong NP-specific CD8+ TRM cells and provided complete protection against influenza virus challenge. Overall, our results demonstrate that this "prime-and-deploy" vaccination strategy is potentially applicable to the development of universal influenza vaccines.

Dual mode LCD with dynamic mode of horizontal switching

  • Lee, Joong-Ha;Lee, Seong-Ryong;Kim, Tae-Hyung;Jhun, Chul-Gyu;Yoon, Tae-Hoon;Kim, Jae-Chang
    • 한국정보디스플레이학회:학술대회논문집
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    • 2009.10a
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    • pp.215-217
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    • 2009
  • The authors propose a novel dual mode liquid crystal display (LCD) which has both dynamic and memory operating LCD modes. The mode uses a horizontal switching and bistable chiral splay nematic (BCSN) LCD. The proposed dual mode does not require pixeldivision and has a higher aperture ratio and resolution than the previously proposed dual mode. Experimental results of the memory and dynamic mode show a high contrast ratio of over 100:1.

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Repeated Neonatal Propofol Administration Induces Sex-Dependent Long-Term Impairments on Spatial and Recognition Memory in Rats

  • Gonzales, Edson Luck T.;Yang, Sung Min;Choi, Chang Soon;Mabunga, Darine Froy N.;Kim, Hee Jin;Cheong, Jae Hoon;Ryu, Jong Hoon;Koo, Bon-Nyeo;Shin, Chan Young
    • Biomolecules & Therapeutics
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    • v.23 no.3
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    • pp.251-260
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    • 2015
  • Propofol is an anesthetic agent that gained wide use because of its fast induction of anesthesia and rapid recovery post-anesthesia. However, previous studies have reported immediate neurodegeneration and long-term impairment in spatial learning and memory from repeated neonatal propofol administration in animals. Yet, none of those studies has explored the sex-specific long-term physical changes and behavioral alterations such as social (sociability and social preference), emotional (anxiety), and other cognitive functions (spatial working, recognition, and avoidance memory) after neonatal propofol treatment. Seven-day-old Wistar-Kyoto (WKY) rats underwent repeated daily intraperitoneal injections of propofol or normal saline for 7 days. Starting fourth week of age and onwards, rats were subjected to behavior tests including open-field, elevated-plus-maze, Y-maze, 3-chamber social interaction, novel-object-recognition, passive-avoidance, and rotarod. Rats were sacrificed at 9 weeks and hippocampal protein expressions were analyzed by Western blot. Results revealed long-term body weight gain alterations in the growing rats and sex-specific impairments in spatial (female) and recognition (male) learning and memory paradigms. A markedly decreased expression of hippocampal NMDA receptor GluN1 subunit in female- and increased expression of AMPA GluR1 subunit protein expression in male rats were also found. Other aspects of behaviors such as locomotor activity and coordination, anxiety, sociability, social preference and avoidance learning and memory were not generally affected. These results suggest that neonatal repeated propofol administration disrupts normal growth and some aspects of neurodevelopment in rats in a sex-specific manner.

All-optical Read Only Memory Employing SOAs

  • Jung, Young-Jin;Park, Nam-Kyoo;Jhon, Young-Min;Lee, Seok
    • Journal of the Optical Society of Korea
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    • v.12 no.1
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    • pp.52-56
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    • 2008
  • An all-optical read only memory utilizing cross gain modulation in semiconductor optical amplifiers (SOAs) has been demonstrated for the first time to our knowledge. In our demonstration, an all-optical 2-to-4 line decoder constructed with SOAs has been employed for the construction of this all-optical read only memory. Storing four characters in an American standard code for information interchange (ASCII) format has been successfully carried out. Each character consisting of seven binary bits could be read out at a rate of 10 Giga characters per second.

Study of the power consumption of ECC circuits designed by various evolution strategies (다양한 진화 알고리즘으로 설계된 ECC회로들의 전력소비 연구)

  • Lee, Hee-Sung;Kim, Eun-Tai
    • Proceedings of the IEEK Conference
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    • 2008.06a
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    • pp.1135-1136
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    • 2008
  • Error correcting codes (ECC) are widely used in all types of memory in industry, including caches and embedded memory. The focus in this paper is on studying of power consumption in memory ECCs circuitry that provides single error correcting and double error detecting (SEC-DED) designed by various evolution strategies. The methods are applied to two commonly used SEC-DED codes: Hamming and odd column weight Hsiao codes. Finally, we conduct some simulations to show the performance of the various methods.

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