• Title/Summary/Keyword: 전도 메커니즘

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Effect of calf strengthening exercise on walking mechanism in middle-aged women (종아리 강화 운동이 중년여성의 보행메커니즘에 미치는 영향)

  • Jong-Geun Kim;Gyeong-Hee Cho
    • The Journal of the Convergence on Culture Technology
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    • v.10 no.4
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    • pp.235-240
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    • 2024
  • We designed this study because it is necessary to take health care from middle age for to healthy old age. The purpose of this study was to confirm the effect of middle-aged women on the walking mechanism by applying an exercise program that can achieve the maximum effect through simple exercise regardless of time and place. A total of 20 subjects were selected from middle-aged women aged 45 years or older, with 10 calf-enhancing exercise groups and 10 control groups. As a result of comparing before and after exercise in the calf-enhancing exercise group, the step length left and right, and double support, step time, and speed were improved. As a result of comparing the walking mechanisms of the calf-enhancing exercise group and the non-exercise group after exercise, the step length left and right, and step time left and right were improved. The positive effect of the walking mechanism was shown through the calf-enhancing exercise regardless of time and place. In particular, it is judged that the stride was widened, resulting in an increase in the speed of walking due to the strength of the lower extremities and the shortening of the one-foot support section, resulting in meaningful results. In future studies, it is considered desirable to present measurement data for each life cycle by evaluating all ages, such as adolescents and the elderly, and to provide it as basic data for causing social problems due to lack of normal exercise.

A Study on the Flame Configuration and Flame Stability Mechanism with a Nozzle Diameter of Laminar Lifted Jet Flame (층류제트 화염의 노즐직경에 따른 안정화 메커니즘과 화염형상에 관한 연구)

  • Kim, Tae-Kwon;Kim, Kyung-Ho;Ha, Ji-Soo
    • Journal of Advanced Marine Engineering and Technology
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    • v.35 no.2
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    • pp.204-215
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    • 2011
  • Flame stability is the one of the main mechanism of laminar lifted flame and flame propagation velocity becomes a yardstick to measure the flame stability. Bilge has presented the flame propagation velocity of the triple flame and the flame stability mechanism related the flame configuration and mixture fraction. However, there was not able to observe all process of flame ignition and extinction for small nozzle diameter. In this paper, we have subdivided the flame configuration and stability mechanism and classified the flame behavior with a nozzle diameter. Also we have subdivided the 'triple flame propagation opened' and the 'triple flame propagation closed' from the triple flame propagation of triple flame criterion.

Charge Trap Flash 메모리 소자 프로그램 동작 시 전하수송 메커니즘

  • Yu, Ju-Tae;Kim, Dong-Hun;Kim, Tae-Hwan
    • Proceedings of the Korean Vacuum Society Conference
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    • 2011.08a
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    • pp.273-273
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    • 2011
  • 현재 사용되고 있는 플로팅 게이트를 이용한 플래시 메모리 소자는 비례축소에 의해 발생하는 단 채널 효과, 펀치스루 효과 및 소자간 커플링 현상과 같은 문제로 소자의 크기를 줄이는데 한계가 있다. 이러한 문제를 해결하기 위하여 silicon nitride와 같은 절연체를 전자의 트랩층으로 사용하는 charge trap flash (CTF) 메모리 소자에 대한 연구가 활발히 진행되고 있다. CTF 메모리 소자의 전기적 특성에 대한 연구는 활발히 진행 되었지만, 수치 해석 모델을 사용하여 메모리 소자의 전하수송 메커니즘을 분석한 연구는 매우 적다. 본 연구에서는 수치 해석 모델을 적용하여 개발한 시뮬레이터를 사용하여 CTF 메모리 소자의 프로그램 동작 시 전하수송 메커니즘에 대한 연구를 하였다. 시뮬레이터에 사용된 모델은 연속방정식, 포아송 방정식과 Shockley-Read-Hall 재결합 모델을 수치해석적 방법으로 계산하였다. 또한 CTF 소자 프로그램 동작 시 트랩 층으로 주입되는 전자의 양은 Wentzel-Kramers-Brillouin 근사 법을 이용하여 계산하였다. 트랩 층에 트랩 되었던 전자의 방출 모델은 이온화 과정을 사용하였다. 게이트와 트랩 층 사이의 터널링은 Fowler-Nordheim (FN) tunneling 모델, Direct tunneling 모델, Modified FN tunneling 모델을 적용하였다. FN tunneling 만을 적용했을때 보다 세가지 모델을 적용했을 때가 더 실험치와의 오차가 적었다. 그 이유는 시뮬레이션 결과를 통해 인가된 전계에 의해 Bottom Oxide 층의 에너지 밴드 구조가 변화하여 세가지 tunneling 모델의 구역이 발생하는 것을 확인 할 수 있었다. 계산된 결과의 전류-전압 곡선을 통해 CTF 메모리 소자의 프로그램 동작 특성을 관찰하였다. 트랩 층의 전도대역과 트랩 층 내부에 분포하는 전자의 양을 시간에 따라 계산하여 트랩 밀도가 시간이 지남에 따라 일정 값에 수렴하고 많은 전하가 트랩 될 수록 전하 주입이 줄어듬을 관찰 하였다. 이와 같은 시뮬레이션 결과를 통해 CTF 메모리의 트랩층에서 전하의 이동에 대해 더 많이 이해하여 CTF 소자가 가진 문제점 해결에 도움을 줄 것이다.

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A study of apoptosis induction of Euonymus alatus (Thunb.) Sieb via mitochondrial pathway prooxidant in leiomyomal smooth muscle cells (귀전우(鬼箭羽)의 인간 자궁근종 세포에서 미토콘드리아 경로를 통한 산화제로서 apoptosis 유도작용에 관한 연구)

  • Kwon, Cha-Nam;Lee, Tae-Kyun;Kim, Dong-Il
    • The Journal of Korean Obstetrics and Gynecology
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    • v.18 no.3
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    • pp.67-76
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    • 2005
  • Purpose : 귀전우(Euonymus alatus, EA)는 현재까지 항종양활성을 나타낸다고 보고되었지만 그 작용 메커니즘에 대해서는 아직 밝혀지지 않은 채 남아 있다. 본 연구에서는, 자궁근종세포(ULSMC)에서 EA의 분자적 수준에서의 작용메커니즘을 연구${\cdot}$검토하고자 하였다. Methods : EA의 열수추출액이 자궁근종세포(ULSMC)와 caspase-3 pretense의 활성도에 미치는 영향을 측정하였다. Results : 우리는 자궁근종에서 EA 유도 세포독성의 메커니즘을 검토하였는바, 근종 세포들은 20-200g/ml 농도의 EA추출물에 6시간 배양될 때, caspase-3가 활성화되고, 그때 세포들은 apoptosis를 유발하게 되었다. EA에 의한 apoptosis의 유도가 진행되었으며, cytochrome- c의 세포질분획에서 양적증가가 caspase-3의 활성보다도 우세하였다. GSH합성의 저해제인 5mM buthionine용액에 전처리는 EA유도 apoptosis를 용이하게 하지만 pan-caspase inhibitor인 Z-VAD-fmk용액 전 처리는 부분적으로 apoptosis유도를 억제하였다. 한편, EA는 건강한 지원자들로 부터 채취한 말초혈액 단핵세포들에 있어서는 독성의 효과는 없었다. Conclusion : 이들 결과들은 EA가 prooxidant로 작용을 하고 그리고 caspase-3 activation과 mitochondrial pathway를 경유하는 apoptosis를 유발한다는 것을 나타낸다. EA의 탕제약제로서 열수추출액이 항산화활성뿐만 아니라, 종양세포에 대한 세포독성효과를 나타낸다고 보고된 바, 이에 향후 근종치료에 대한 임상연구가 필요할 것으로 보인다.

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Development Processes of Well-being Market and Mechanism of Well-being Marketing (웰빙산업 시장의 형성과정과 웰빙마케팅 메커니즘에 관한 연구)

  • Lee, Min-Sang;Sim, Wan-Seop
    • Proceedings of the Korean DIstribution Association Conference
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    • 2005.11a
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    • pp.385-416
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    • 2005
  • The rapid growth of wide Korean Well-being Market in recent years. The purpose of this is to define the definition of 'Development Processes of Well-being Market and Mechanism of Well-being Marketing' and discover the main factorss of the Mechanism of Well-being Marketing in order for Korean Well-being Market to be Successful, it must have a Competitive Advantage. But as of yet, there virtually no such strategies. Hitting upon this situation, this study intends to discover the Mechanism of Well-being Marketing in Korean Well-being Market Consequently, the study results show that Market Advantage like Well-being, Real valuece, and Well-being Marketing product in Korean Well-being Market.

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Reaction Mechanism of Low Temperature NH3 SCR over MnOx/Sewage Sludge Char (MnOx/Sewage Sludge Char를 이용한 저온 NH3 SCR의 반응 메커니즘)

  • Cha, Jin-Sun;Park, Young-Kwon;Park, Sung Hoon;Jeon, Jong-Ki
    • Applied Chemistry for Engineering
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    • v.22 no.3
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    • pp.308-311
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    • 2011
  • The reaction mechanism of selective catalytic reduction of NOx over sewage sludge char impregnated with MnOx using $NH_3$ as the reducing agent was investigated. The active Mn phase was shown to be $Mn_3O_4$ from the XRD analysis. Adsorption was the dominant NOx removal mechanism at low temperatures below $150^{\circ}C$ although reduction reaction also contributed partly to the NOx removal at $100{\sim}150^{\circ}C$. The reaction rate constants of NOx removal over non-impregnated and MnOx-impregnated active chars were compared based on experimental results. The MnOx-impregnated char was shown to have a higher reaction rate constant and a higher NOx removal efficiency due to a higher collision coefficient and a lower activation energy. The activation energy for both chars was shown to be relatively low (10~12 kJ/mol) under the experimental conditions of this study.

A Strong Address Generation and Verification Scheme using Hash Functions in the IPv6 Environments (IPv6 환경에서 해쉬 함수 기반 강건한 주소 생성 및 검증 기법)

  • Gyeong, Gye-Hyeon;Ko, Kwang-Sun;Eom, Young-Ik
    • Journal of the Korea Institute of Information Security & Cryptology
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    • v.17 no.1
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    • pp.115-119
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    • 2007
  • The IPv6 protocol provides the method to automatically generate an address of a node without additional operations of administrators, Before the generated address is used, the duplicate address detection (DAD) mechanism is required in order to verify the address. However, during the process of verification of the address, it is possible for a malicious node to send a message with the address which is identical with the generated address, so the address can be considered as previously used one; although the node properly generates an address, the address cannot be used. In this paper, we present a strong scheme to perform the DAD mechanism based on hash functions in IPv6 networks. Using this scheme, many nodes, which frequently join or separate from wireless networks in public domains like airports, terminals, and conference rooms, can effectively generate and verify an address more than the secure neighbor discovery (SEND) mechanism.

Implementation of authentication mechanism for 3GPP, 3GPP2 on java card (자바 카드상에서의 3GPP, 3GPP2 인증 메커니즘 구현)

  • 조승환;전성익;이정우;이옥연;한진희;이세광
    • Journal of the Korea Institute of Information Security & Cryptology
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    • v.13 no.6
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    • pp.67-75
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    • 2003
  • The development of mobile phone is growing fast in the all over the world. Besides the basic voice communication, many multimedia services and global roaming service are capable in the 3rd generation mobile telecommunication. Because mobile phone has been the essential tool to communicate, the protection of privacy and the safe transmission are critical ones. In synchronous, asynchronous mode IMT2000 service, the mechanism of mutual authentication and generation of cipher key and integrity key are implemented in smart card chip called UIM, USIM. In this paper, we describe the authentication mechanism of 3GPP and 3CPP2 and its implementation results. Then, we specify a few problems which are not defined in standard.

Literature Review on Material Development and Performance Evaluation Method for EMP Shielding Concrete (EMP 차폐 콘크리트 개발 및 성능평가 방법에 관한 문헌 연구)

  • Lee, Woong-Jong;Lee, Hwan;Kim, Young-Jin
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.21 no.12
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    • pp.67-76
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    • 2020
  • The purpose of this study was to derive the directionality of technology development of high-power electromagnetic pulse (EMP) shielding concrete and standardization of a shielding performance evaluation method. Because the EMP shielding mechanism of concrete has not been identified clearly, and the verification method for EMP shielding performance has not been standardized, it is difficult to compare the research results between researchers. The development direction of EMP shielding concrete was derived from a consideration of the electromagnetic wave loss mechanism of metal. The standardization direction for verifying the EMP shielding performance of concrete was derived from a consideration of the electrical properties of concrete and the shielding performance evaluation methods of previous studies. As a result, the development of electrically conductive concrete is required, and test methods classified by the electromagnetic wave loss mechanism should be applied. For quality verification, the development of EMP shielding concrete will be feasible and its performance can be evaluated if a test method referencing the generalized shielding evaluation method (MIL-STD, etc.) is applied.

A Precision Rotational Device using Piezoelectric Elements and Impact Drive Mechanism (압전소자와 충격구동 메커니즘을 이용한 초정밀 회전장치)

  • Ten, Aleksey-Deson;Ryu, Bong-Gon;Jeon, Jong-Up
    • Journal of the Korean Society for Precision Engineering
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    • v.27 no.1
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    • pp.49-57
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    • 2010
  • This paper describes the design, construction, and fundamental testing of a precision rotational device that utilizes piezoelectric elements as a source of driving force and impact drive mechanism as a driving principle. A novel device structure is designed and the numerical simulations about the static displacement, stress distribution, and mode shape of the designed structure are performed. A fabricated rotational device has been rotated successfully by applying saw-shaped voltages to the piezoelectric elements. The one-step rotational angle was $0.44{\times}10^{-3}$ rad at the applied voltages of 80V. The angular velocities of the device were revealed to be increased as the driving frequency and voltage were respectively increased and the preload was decreased. The device has a feature that it can be translated as well as rotated. An experimental result shows that the device was translated by ${\pm}4.56{\mu}m$ maximum when the 120V sinusoidal voltages with a phase difference of $180^{\circ}$ were respectively supplied to two piezoelectric elements.