• Title/Summary/Keyword: 조직기억

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A Study on Change of Texture During Thermal Cycling in Cu-Zn-AI Shape Memory Alloy (Cu-Zn-AI 형상기억 합금의 열사이클에 따른 집합조직의 변화에 관한 연구)

  • Hong, D.W.;Park, Y.K.
    • Journal of the Korean Society for Heat Treatment
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    • v.5 no.3
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    • pp.179-185
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    • 1992
  • The shape memory effect results from the martensite transfomation of each individual grain. Thus it is necessary to study the texture and its variation. In this study the change of texture during thermal cycling and it's effect on shape memory ability are investigated. The major component of the rolling texture in the parent phase is identified (001) [110], and minor components are (112) [110], (111) [112], {hkl}<100> fiber texture is developed at $45^{\circ}$ from rolling direction. In the case of martensite phase, it is estimated that the major component is (011) [100] and the minor components are (105) [501], (010) [101] and (100) [001]. According to thermal cycling. severity of texture, especially (001) [110] component in parent phase and (011) [100] component in martensite phase are increased. The shape memory ability is increased with increase of thermal cycles and also increased as the direction of specimen approach to $45^{\circ}$ from rolling direction. After first thermal cycling the temperature of transformation can be define clearly and Ms and As are raised by thermal cycling.

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A Study on the Shera′s sociological aspect of librarianship. (세라(Shera)의 도서관 인식론 연구)

  • 남태우
    • Journal of the Korean Society for information Management
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    • v.20 no.1
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    • pp.199-230
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    • 2003
  • The purpose of this study is on the Shera's sociological aspect of librarianship. Jesse H. Shera, educator, philosopher, and theoretician, considered that perhaps his most significant contribution to librarianship was not a “thing” but a “concept”. Library was created to meet certain social necessities, and that its development is closely related not only to intellectual history but also to change in the organizational structure and the value system of its supporting culture. It is axiomatic, then, that the library as a social instrumentality. is, as it has always been, conditioned and shaped by the social milieu within which it function. Therefore we are concerned with the need for a new epistemological discipline, a body of new about knowledge itself.

Microstructure and Transformation Characteristics with Cooling Rate in Cu-Al-Ni Based SMA Ribbons Fabricated by Melt-Spinning (Cu-Al-Ni계 형상기억리본 제조시 냉각속도에 따른 미세조직 및 변태특성)

  • Lee, Y.S.;Jang, W.Y.;Lee, E.G.
    • Journal of the Korean Society for Heat Treatment
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    • v.13 no.4
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    • pp.265-271
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    • 2000
  • The microstructural change and transformation characteristics with cooling rate i.e. wheel speed were investigated in 82.8wt%Cu-12.8wt%Al-4.3wt%Ni SMA ribbons fabricated by melt-spinning. The thickness and width of ribbon were decreased with increasing wheel speed, while the uniformity of it was improved. At same wheel speed, the grain size of the contact surface of ribbon was smaller than that of free surface. The mean grain size was decreased with increasing wheel speed, resulted in obtaining grains with $3{\mu}m$ in mean diameter in the wheel speed of 30 m/s. However, micro-voids and cracks at grain boundary could be observed at higher wheel speed. $M_s$ and $A_s$ temperatures were decreased, and $M_s{\sim}M_f$ and $A_s{\sim}A_f$ temperature ranges were broadened with increasing wheel speed. All the ribbons were retained the ordered $D0_3$ due to rapid cooling, the volume fraction of it was increased with increasing wheel speed.

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A Study on the Moon Jae-in Government's Records of 'Committees Related to Elimination of Accumulated Ills' (문재인 정부의 '적폐청산 위원회' 기록 연구 교육부의 『역사교과서 국정화 진상조사 백서』를 중심으로)

  • Yi, Kyoung-yong
    • The Korean Journal of Archival Studies
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    • no.60
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    • pp.5-48
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    • 2019
  • In this paper, under the assumption that the documents related to the Military and Political Government of the Government of Japan are an important record that should be recorded as social memories of the time, the Ministry of Education's history textbook, In the white paper (Appendix) issued by the Investigation Committee, we analyzed the main contents of the records produced by the organization responsible for the history textbooks and the management of them, which were presented as evidence of the power abuse of the Park Geun-hye Government.

A Study on Understanding of Middle-East Terrorism : Focusing on Islamic Fundamentalism (이슬람 원리주의를 통해 본 중동지역테러리즘의 이해)

  • Park, Gi-Beom;Kang, Min-Wan;Jun, Yong-Tae
    • Korean Security Journal
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    • no.12
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    • pp.149-175
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    • 2006
  • The purpose of this study is to understand and analyze the character of Islamic fundamentalism and Middle-Ease Terrorism. The aim of Islamic fundamentalism is reconstruction of Ummah(Muslim Unity), thee early society of Muhammad's age. Islamic movement insist to restore the spirit of Islam and purify the society of Islam from the United State and Western world. Now, Islamic fundamentalism movement as a new ideology, appeals to muslim in the world. The concept of modern national state from the Western countries do not accord with the traditional Islamic principles of reign and a spirit of nationalism. On the other hand, Islamic movement have no legitimacy in the system of modern state which govern the Arab world, regardless of the form of government. For this reasons, Islamic fundamentalist have an insecure position and their political activities. It is yet far from their purpose, to reconstruct the muslim unity, to realize the Islamic political principle close to their practical methods. Yet Islamic fundamental movement have not overcome the system of secular state. The Middle East terrorism supported by government might be eradicated by America's anti-terrorism policy. However, it will be serious and spread all over the world that the terrorist attack against the U. S. and western countries is acted by militant warriors of Islamic fundamentalism, uniting Arab and Islamic people's emotions against America and western countries. There are some reasons that we need to focus on the Arab and Islamic fundamentalism. We need to get out of misunderstanding and discrimination about Islamic religion and culture from America's and Western' standard Which are only their new world order. The discrimination of America and western nations against muslim could make other ideologies, opposite to the world peace. There are a lot of foreign workers from Islam countries in Korea. We need to give consideration and attention to them for the our globalization and world peace. It is time to consider what to do for the nation's profit(economical, political, strategic)with right understanding. We are not safe and free from the terrorism yet.

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Anti-amnesic and Neuroprotective Effects of Artemisia argyi H. (Seomae mugwort) Extracts (섬애쑥 추출물의 뇌 신경세포 보호효과에 의한 학습 및 기억능력 개선 효과)

  • Ha, Gi-Jeong;Lee, Doo Sang;Seung, Tae Wan;Park, Chang Hyeon;Park, Seon Kyeong;Jin, Dong Eun;Kim, Nak-Ku;Shin, Hyun-Yul;Heo, Ho Jin
    • Korean Journal of Food Science and Technology
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    • v.47 no.3
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    • pp.380-387
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    • 2015
  • The anti-amnesic effect of Artemisia argyi H against trimethyltin (TMT)-induced learning and memory impairment and its neuroprotective effect against $H_2O_2$-inducedoxidative stress were investigated. Cognitive behavior was examined by Y-maze and passive avoidance test for 4 weeks, which showed improved cognitive functions in mice treated with the extract. In vitro neuroprotective effects against $H_2O_2$-induced oxidative stress were examined using 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl-tetrazolium-bromide and lactate dehydrogenase (LDH) assays. A. argyi H. extract showed protective effects against $H_2O_2$-induced neurotoxicity; moreover, LDH release into the medium was inhibited. Finally, high-performance liquid chromatography (HPLC) analysis showed that eupatilin and jaceosidin were the major phenolic compounds in A. argyi H. extract. These results suggest that A. argyi H. could be a good source of functional substances to prevent neurodegenerative diseases.

Antioxidant Effect of Chungkukjang Supplementation against Memory Impairment induced by Scopolamine in Mice (Scopolamine으로 유도된 기억 손상 마우스에서 청국장 식이의 항산화 효과)

  • Kong, Hyun-Joo;Lee, Kyung-Eun;Yang, Kyung-Mi
    • Journal of the East Asian Society of Dietary Life
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    • v.26 no.3
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    • pp.237-249
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    • 2016
  • In this study, the antioxidant effect of Chungkukjang supplementation against memory impairment and oxidative stress in scopolamine (2 mg/kg i.p)-injected mice was investigated. The experimental animals were divided into five groups and fed experimental diets for 12 weeks; normal diet group (C), scopolamine + normal diet group (S), scopolamine + 63.0% soybean Chungkukjang supplementation group (SS), scopolamine + 45.0% Yakkong Chungkukjang supplementation group (SY), and scopolamine + 50.0% black foods such as black rice, black sesame seeds, and sea tangle added Yakkong Chungkukjang group (SYB). For the results of food intake, body weight gain, and brain weights, levels of scopolamine-injected groups were lower than the levels of the control group. The reduced brain weight of the scopolamine-injected group (S) was regulated to control level by supplementation of three types Chungkukjang. In the oxidative stress indicator, nitric oxide and malondialdehyde levels in serum of scopolamine-injected mice were higher than those of other groups. However, supplementation of soybeans, Yakkong and black foods added Yakkong Chungkukjang was proven to regulate them. Antioxidant enzyme activities such as superoxide dismutase (SOD) and glutathione-S-transferase (GST) in serum showed no significant differences among the groups. The reduced levels of vitamin A and vitamin E in serum and brain tissue of scopolamine-injected mice were controlled by supplementation of three types of Chungkukjang. Total antioxidant capacity (TAC) of scopolamine-injected group was lower than those of other groups. However, TAC was significantly elevated by Chunggukjang supplementation. Therefore, antioxidative effects of soybeans, Yakkong, and black foods added Yakkong Chungkukjang supplementations against oxidative stress in scopolamine-injected in mice could expected.

Protective effect of Gabjubaekmok (Diospyros kaki) extract against amyloid beta (Aβ)-induced cognitive impairment in a mouse model (아밀로이드 베타(amyloid beta)로 유도된 인지장애 마우스 모델에서 갑주백목(Diospyros kaki) 추출물의 인지기능 및 뇌 신경세포 보호 효과)

  • Yoo, Seul Ki;Kim, Jong Min;Park, Seon Kyeong;Kang, Jin Yong;Han, Hye Ju;Park, Hyo Won;Kim, Chul-Woo;Lee, Uk;Heo, Ho Jin
    • Korean Journal of Food Science and Technology
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    • v.51 no.4
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    • pp.379-392
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    • 2019
  • The current study investigated the effect of Gabjubaekmok (Diospyros kaki) ethanolic extract (GEE) on $H_2O_2$-induced human neuroblastoma MC-IXC cells and amyloid beta $(A{\beta})_{1-42}$-induced ICR (Institute of Cancer Research) mice. GEE showed significant antioxidant activity that was evaluated based on ABTS, DPPH scavenging activity, and inhibition of malondialdehyde (MDA) and acetylcholinesterase activity. Further, GEE inhibited ROS production and increased cell viability in $H_2O_2$-induced MC-IXC cells. Administration of GEE ameliorated the cognitive dysfunction on $A{\beta}$-induced ICR mice as evaluated using Y-maze, passive avoidance, and Morris water maze tests. Results of ex vivo test using brain tissues showed that, GEE protected the cholinergic system and mitochondrial functions by increasing the levels of antioxidants such as ROS, mitochondrial membrane potential (MMP), and adenosine triphosphate (ATP) against $A{\beta}$-induced cognitive dysfunction. Moreover, GEE decreasd the expression levels of apoptosis-related proteins such as $TNF-{\alpha}$, p-JNK, p-tau, BAX and caspase 3. While, expression levels of p-Akt and $p-GSK3{\beta}$ increased than $A{\beta}$ group. Finally, gallic acid was identified as the main compound of GEE using high performance liquid chromatography.

Effect of intake of dried mackerel on fatty acid compositions in liver and nervous tissue (건조 고등어 섭취가 마우스의 간 및 신경조직의 지방산 조성에 미치는 영향)

  • Choi, Hyung-Ju;Kim, Kyung-Kun;Lim, Sun-Young
    • Journal of Life Science
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    • v.17 no.4 s.84
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    • pp.546-551
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    • 2007
  • The purpose of this investigation was to determine the effect of feeding dried mackerel as a means of increasing the intake of these n-3 polyunsaturated fatty acids on fatty acid compositions in liver and nervous tissue. Twenty male mice aged at 4 weeks were fed on the control (5% palm oil, control group) and 5% dried mackerel diets (mackerel group) for four weeks. In fatty acid compositions of liver and cortex, levels of total n-3 fatty acid, specially docosahexaenoic (22:6n-3, DHA) and eicosapentaenoic (20:5n-3, EPA) acids, were increased in the mackerel group compared to the control group, while docosapentaenoic acid (22:5n-6, DPAn-6) levels were decreased (p<0.05). In cerebellum and retina, levels of DHA were not significantly different between the control and mackerel groups, but levels of total n-6 fatty acids and arachidonic acid (20:4n-6, AA) were decreased in the mackerel group. These results indicated that intake of 5% dried mackerel increased levels of n-3 polyunsaturated fatty acids in cortex. Thus, we will investigate the relationship between brain function and cortex fatty acid compositions following intake of mackerel by assessing discrimination leaning ability.

Effects of Gastrodia elata Extracts on Scopolamine-induced Memory Impairment in Rats (천마 추출액이 Scopolamine으로 유발된 기억력 감퇴 흰쥐에 미치는 영향)

  • Kim, Jin-Ho;Choo, Han-Na;Park, Eun-Hye;Jeong, Jong-Kil;Kim, Kyeong-Ok;Kim, Jeong-Sang
    • Journal of the Korean Society of Food Science and Nutrition
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    • v.42 no.4
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    • pp.595-599
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    • 2013
  • Alzheimer's disease is a progressive neurodegenerative disorder characterized by a gradual decline in memory associated with shrinkage of brain tissue, with a localized loss of neurons mainly in the hippocampus and basal forebrain. This study investigated the neuroprotective effect of Gastrodia elata aqueous extracts against scopolamine-induced neurotoxicity in the hippocampus of male Sprague-Dawley rats. The animals (n=25) were divided into five different groups with five animals per each group. The normal group (Nor) was administered with saline, while the control (Con) group was administered saline after scopolamine treatment. The experimental group (Exp) was administered Gastrodia elata aqueous extracts (200 mg/kg body weight) for 20 or 30 days after scopolamine treatment. From a light microscopy study, the nuclei of neurons in the hippocampus were more shrunken or condensed in the 20 or 30 day control groups compared to experimental groups. The densities of neurons from the CA1 and CA3 area of the hippocampus in the Exp increased compared with the Con. Amyloid ${\beta}$ protein, containing PAS-positive materials, was lower in the Exp compared with the Con. The present study demonstrates that Gastrodia elata aqueous extracts possess neuroprotective potential, thus validating its use in alleviating the toxic effects of scopolamine.