• Title/Summary/Keyword: Chracteristics

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Stability Of $ZnO-Pr_{6}O_{11}-CoO-Cr_{2}O_{3}-Y_{2}O_{3}$Based Varistors with Cooling Rate (냉각속도에 따른 $ZnO-Pr_{6}O_{11}-CoO-Cr_{2}O_{3}-Y_{2}O_{3}$계 바리스터의 안정성)

  • 류정선;정영철;김향숙;남춘우
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 2001.07a
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    • pp.410-414
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    • 2001
  • The microstructure, V-I characteristics, and stability of ZnO-Pr$_{6}$O$_{11}$-CoO-Cr$_2$O$_3$-Y$_2$O$_3$based vairstors were investigated with cooling rate in the range of 2~8$^{\circ}C$/min. The cooling rate relatively weakly affected the microstructure, and the varistor voltage and the leakage current in the V-I chracteristics. But the nonlinear exponent relatively strongly affected by cooling rate. And the cooling rate also greatly affected the stability for DC stress. In gross, the varistors cooled with 4$^{\circ}C$/min exhibited the highest performance in the densification, nonlinearity, and stability. Especially, they exhibited a high stability, in which the variation rate of the varistor voltage and the nonlinear exponent is -1.44% and -4.85%, respectively, under more severe DC stress such as (0.80 V$_{1mA}$9$0^{\circ}C$/12 h)+(0.85 V$_{1mA}$115$^{\circ}C$/12 h)\`(0.90 V$_{1mA}$12$0^{\circ}C$/12 h)+(0.95 V$_{1mA}$1$25^{\circ}C$/12 h)+(0.95 V$_{1mA}$15$0^{\circ}C$/12 h). It should be emphasized that the stability of these varistors is much superior to that of others.s.of others.s.

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The Biological Base of Learning and Memory(II):A Review of the Studies Employing Animal Model Systems (학습과 기억의 생물학적 기초(II) :실험동물 모델체계를 사용한 연구들의 개관)

  • 문양호
    • Korean Journal of Cognitive Science
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    • v.7 no.3
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    • pp.37-60
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    • 1996
  • From the biopsychological point of view,learning could be defined as the processes to transfer the information that we obtain from environment to the neural circuits in the brain.In the studies to determine the biological substrates of learning and memory,there was a remarkable effort to identify neural circuits related with a specific type of learning and to describe the mechanixm of neural plasticity of learning and memory,under the assumption that the memory orinformation may be stored as a modificationof neural synapes in the central nerviys system.On the other hand,there was a different kind of tendency to analyze the mechanism of interactions between neural substrates involved in learning and memory,under the assumption that a specific information may be represented in the patterns of comples neural network of the central nervous system.The present review,in the former position.focused on the research methods and the chracteristics and finding of the investigations employing animal model systems to indentify the essential site of engram for learning and memory.Specifically,the review presents major advances in ourunderstanding of the memory trace circuit for a specific type of learning,with the use of animal model system,the detemination of the critical lodi of neuaral plastic chabges In learing abd memory,and the neurophysiological an biocemical mechanixms of the neural modifia by learint.

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A Shear Bond Chracteristics of Composite Slab with Closed-Shape Deckplate (폐쇄형 데크플레이트를 사용한 합성슬래브의 전단부착 특성에 관한 연구)

  • Ju, Gi Su;Park, Sung Moo
    • Journal of Korean Society of Steel Construction
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    • v.13 no.5
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    • pp.557-566
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    • 2001
  • Composite slab with deckplate needs sufficient bond strength between deckplate and concrete to conduct composite behavior Composite slab can transfer the shear by either chemical adhesion interface interlock, or active friction. There are several way of mechanical shear connection in composite slab. that is embossments shear connector shape of deckplate etc. Effect of mechanical interaction is deped on shape of deckplate which is to prevent peeling between deckplate and concrete and an amount of shear connector. The behavior and strength of the connection between the decking and the concrete slab due to embossments and end anchorage may be estimated using the push-off tests described in this paper We proposed the equation of shear bond strength in the composite slab It will be use to design by basic data in composite slab.

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Distribution and Habitat Chracteristics of Lonicera japonica Thunb. in the Inland and the Seashore Areas of Korea

  • Kim, Seong-Min;Shin, Dong-Il;Yoon, Seong-Tak;Song, Hong-Seon
    • Korean Journal of Medicinal Crop Science
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    • v.15 no.5
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    • pp.362-366
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    • 2007
  • This study was conducted to evaluate the status of habitat distribution, environmental characteristics and plant species growing with Lonicera japonica in its habitats. In the distribution of plant coverage below 30%, it was 84.6% in the inland area and 80.7% in the seashore area. There was similar coverage in both inland and seashore areas. But the average relative coverage in the seashore area was 26.1%, which is a little higher than that of the inland area (22.5%). In the habitats, both inland and seashore areas showed a high distribution ratio below 10 degrees. But among them, inland areas showed a high distribution ratio (62.4%) below 10 degrees, which was about twice as much as the seashore areas (32.2%). Habitat distribution was most often found on the southern slopes in both inland and seashore areas. The average soil pH of Lonicera japonica habitat was 5.2 in the inland areas and 6.9 in the seashore areas. Also, the seashore areas showed little content of $P_2O_5$, but high content of K, Mg, Na on the other hand compared to the inland area. Miscanthus sinensis was the highest importance value (16.4) among plants growing with Lonicera japonica in their habitats in both inland and seashore areas. But in the inland areas, Artemisia princeps showed the highest importance value, and Miscanthus sinensis was the highest in the seashore areas.

Biomass Production of Pinus densiflora forma erecta Uyeki by Planting Density and Its Allocation Chracteristics (식재밀도에 따른 강송의 Biomass 생산 및 배분 특성)

  • 이돈구;권기철;김영환
    • Journal of Korea Foresty Energy
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    • v.18 no.1
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    • pp.6-10
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    • 1999
  • This study was conducted to examine biomass production and its allocation characteristics by the planting density for 12- year - old Pinus densiflora forma erecta Uyeki plantation located in Chilbo Experimental Forest of Seoul National University in Suwon, Kyonggj-do. Different sample trees were selected for harvest by the planting density as follows; six trees from 1.0m X 1.0m, five trees from 1.8m X 1.8m, four trees from 3.0m X 3.0m. Stem, previous year branches, current year branches, previous year needles and current year needles were weighed respectively with the stratified clipping method, and biomass production and its allocation characteristics were analyzed : (1) Total biomass of the above-ground was the highest at the planting density of 1.8m X l.8m and followed by 1.0m X l.0m. (2) The higher the planting density was, the lower the ratio of biomass in branches and needles. (3) As the planting density decreased, the moisture contents of stem and current year branches increased but those of needles and previous year branches decreased. (4) Maximum photosynthetic layer appeared in the upper portion of the tree at higher density plantation.

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The Style Characteristics and Illustration of Armors Worn by high Navy Officers During the period of Japanese Invasion of Korea(1592~1598) (임진왜란기(1592~1598) 상급 수군 갑옷갑[甲]의 유형별 특성과 일러스트화)

  • Lee, Joo-Young
    • Journal of the Korean Society of Costume
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    • v.63 no.7
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    • pp.94-108
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    • 2013
  • This study is about the armors that high navy officers of Joseon wore during the period of Japanese invasion of Korea(1592~1598). The kinds of armors that these officers wore during this period are Sueungap, cheolgap, pigap, jigap and myeongap. Sueungap, cheolgap, pigap are all described in literatures, which were released in that period and the early Joseon period. According to publications that were released during that period, Yuyeopgap was a type of an iron armor. Armors that are recorded in only literatures published in the early Joseon period include swaejagap, gyeongbeongap, dujeonggap, hwangdongdujeonggap and dudumigap. Myeongap is found only in publications that were made in the above war time. The styles of armors are largely classified into chalgap and dujeonggap. The chalgap-styled armors used gapchal as their main component. Dujeonggap-styled armors used fabrics and dujeong. The names and the manufacturing methods of the gapchal did not changed since its creation in the early Joseon period until the above wartime. But, their shapes were considerably changed between the two times. This is clearly shown in armors that were found in the moat of the Dongrae-eup fortress. Dujeonggap-styled armors that were used during the period of the Japan-Korea war were a successor to those of dujeonggap-styled armors of the early Joseon period. But the former armors were different from the latter in that they had no gapchal inside. They are well represented by Jeong Chung Sin's armor.

Variation of Major Characters in Soybean Varieties II. Effects of Day Length (대두품종의 주요특성 변이 II. 일장조건의 영향)

  • 이성춘;최경구;김진호;장영남
    • KOREAN JOURNAL OF CROP SCIENCE
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    • v.35 no.1
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    • pp.10-15
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    • 1990
  • These experiments were conducted to investigate the effect of day length on some chracteristics and seed weight in the soybean cultivars. Those were classified into three type's of seed weight with delaying seeding date in the previous paper. Flowering was delayed as the longer day length was employed. When the length became longer. the number of leaves at flowering greatly length of main stem and the number of nodes at maturity greatly increased. The seed weight decreased when the day length was longer than 14 hours. Negative correlation was obtained between seed weight and day length. There was negative correlation between seed weight and the number of days required to flowering, and length of main stem and the number of nodes at maturity. Type I cultivars decreased in seed weight when the day length was longer than 16 hours, but this trend was found to be clear with type II cultivars. Type III cultivars decreased in seed weight with increasing the day length.

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Acupuncture & Moxibustion Bibliographic Studies on the Wei symptom for Clinical Treatment (위증(痿證)의 침구 치료에 대한 문헌 고찰)

  • Park, Man Young;Won, Jin Hee;Kim, Sung Chul
    • Journal of Physiology & Pathology in Korean Medicine
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    • v.26 no.6
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    • pp.842-848
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    • 2012
  • This study was performed to investigate the acupuncture & moxibustion therapy of the Wei symptom(痿證) in order to find out the clinical possibility. We investigated the acupuncture & moxibustion therapy of Wei symptom through six books published after 1993, searched sites as like 'Oasis', 'Pubmed', 'RISS', 'KISS', 'NDSL' and 'Google scholar'. Acupuncture & moxibustion prescriptions recorded in the orietal medicine literatures that were published before and after 1993 had a similar basis. Since 2000, in the clinical papers on the wei symptom searched from domestic journal, sa-am and dong's acupuncture therapy were mainly applied, but papers were confined in a case study. Since the mid-2000s, the clinical effectiveness of bee venom and electroacupuncture therapy on the wei symptom were uncovered, but the researches about the chracteristics in accordance with acupoints are more required. Since 2010, the mechanism of the bee venom and electroacupuncture on the wei symptom was revealed in animal experiments. On this basis, the systematic clinical studies beyond case paer or pilot study is(are) needed. The development of various treatment implements as like electroacupuncture, pharmacopuncture was required to access the incurable disease like wei syptom, and the efforts of providing evidence through systemic clinical trials are needed.

Extracellular Wood-degradative Enzymes from Lentinus edodes JA01 (표고 균주(菌株) JA01에서 분비되는 세포외(細胞外) 목재성분(木材成分) 분해효소(分解酵素)에 관하여)

  • Hong, Soon-Woo;Shin, Kwang-Soo;Yoon, Yeup;Lee, Won-Kyu
    • The Korean Journal of Mycology
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    • v.14 no.3
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    • pp.189-194
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    • 1986
  • The aim of this study was to investigate physiological chracteristics of Lentinus edodes in Korea. We tried to detect properties of the several wood-degradative enzymes and investigate patterns of the enzyme production. A specific carbon source was used in the enzyme induction media for each enzymes, and the crude extract was used for the enzyme solution. With these enzyme solution, we investigated optimum temperature and pH conditions of their reactions. Moreover we investigated transition patterns of the enzyme production of the several wood-degrad­ative enzmes from Complex and Saw dust media for the purpose of studying the mechanisms of the wood component degradation by this fungus. It was assumed that the order of the wood com­ponent degradation was cellulose, xylan, and then pectic substances, and that the synergistic effects of these substances also influenced the degradation of wood components.

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A Study on the Restoration of Renaissance Costume (16세기(世紀) Renaissance시대(時代)의 복식분석(服飾分析)과 재현(再現))

  • Mun, Yun-Kyeong;Lee, Soon-Hong
    • Journal of Fashion Business
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    • v.7 no.4
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    • pp.1-16
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    • 2003
  • Nowadays, retro to the past fashion is appeared just as often as new challenge and trial. The style of Renaissance Era is the most often revival theme for contemporary fashion. So, this study was focused on 16C of Renaissance costume. It is investigated the characteristics of Renaissance costume through referring the literature to be able to restore the past costume as through as possible with the object of building database for developing new design. This study is done in two different ways at the same time, direct study to restore and indirect study to refer. Direct one is of the past costume as thoroughas possible based on referring to the originals. The other is referring the costume historical literature The costumes to restore is chosen among 16C famous pictures on the basis of how much they can show the typical chracteristics of 16C costume. Materials including textiles and ornaments which are necessarily to restore were shopped in Dongdeamoon Market. Some materials had a problem to get exactly the same one in Seoul on 21C. After visiting imes, the materials is chosen as similar as originals. Three sets of costume were restored on the basis of referring "Pattern of Fashion" written by Janet Arnold. The costumes were restored by reinforcing bodice based on the size of waist and in every three works. The way of sewing is based on hand sewing for details and machin-sewing for seam. Quilting intl lining is uwed giving the fabric stiffness to maintain the form from the heavy padding. Also the part of piles on margins is used darts instead of gather, because of reducing bulkiness of seam. General closing methods are hook and eyes, and lacing with points.