PMN-PZT 세라믹스에 있어서 열에이징 효과

이개명 濟州大學校工科大學産業技術硏究所 1995 尖端技術硏究所論文集 Vol.6 No.-

Two types of Pb(Mn1/3Nb2/3)O₃+PZT ceramics had been fabricated by hot-pressing method. One had coarse grain and the other had fine grain due to Cr₂O₃ addition. These specimen were poled by applying the DC electric field in various steps. The effects of thermal aging on their piezoelectric characteristics and temperature stability of the frequency were investigated. The results are as follows. Change rates of piezoelectric characteristics by thermal aging in small-grain size specimens were greater than in large-grain size specimens. And only small-grain size specimens could have been better frequency temperature stability through thermal aging.

Pb(Zr0.53)O₃+ x[wt%]Cr₂O₃세라믹스의 공진주파수 온도안정성 및 열에이징 효과

이개명,임대관 濟州大學校工科大學産業技術硏究所 1998 尖端技術硏究所論文集 Vol.9 No.2

In this paper, Pb(??)O₃ + x[wt%]Cr₂O₃ceramics were fabricated. and thermal aging effects on the specimens were investigated. Thermal shock changed the temperature coefficients of resonant frequency of the specimens but, after thermal aging, the changing rate of their temperature coefficients due to thermal shock became very low. Thermal aging increased relative dielectirc constants of the specimen with no and a small Cr₂O₃ additives. After thermal aging, Electro-mechanical coopting factor of all specimens decreased but the specimens with Cr₂O₃ additives had the smaller temperature coefficients for resonant and antiresonant frequencies.

刈取管理가 Pearl Millet[Pennisetum typhoideum]의 刈取後 新枝의 發生, 乾物重 및 枯死에 미치는 影響

安桂洙,趙聖均 順天大學校 1984 論文集 Vol.3 No.1

This experiment was carried out to investigate the effects of the different cutting stage and cutting height on the appearance, dry weight and the death of new bud (branch and tiller) of pearl millet (Pennisetum typhoideum). The cultivar used in the present study was feed mill. The experiment was undertaken in the Experimental Livestock Farm of Suncheon National College, 1984. The results obtained are summarized as follows: 1. The frequency of the branching was increased and the rate of the tillering was decreased as the high stubble height, both of the frequency of the branching and the rate of the tillering were also decreased as the late cutting stage. 2. The yield of forage mostly depended on the tiller regardless of cutting height, and minor portion of the yield was resulted from the branch. 3. In the number of dead bud, there was no significant difference in different cutting stage, and was increased as the low stubble height.

동화를 통한 극화놀이가 유아의 어휘력과 언어표현력에 미치는 영향

최계숙,김영중 제주관광대학 2005 論文集 Vol.11 No.-

언어는 인간이 살아가기 위해 필요한 도구이다. 현대 사회에서 언어의 역할은 더욱 중요하게 인식되고 있으며, 유아기 언어 발달에 관한 교육적 관심이 점점 높아지고 있다. 따라서 본 연구는 5세 유아를 대상으로 하여 동화를 통한 극화놀이가 유아의 어휘력 및 언어표현력에 어떠한 영향을 미치는지 그 효과를 알아보는데 목적을 두었다. 본 연구에서 극화놀이는 교사가 들려주는 동화를 듣고 동화에 나타난 문제 상황이나 사건 또는 등장 인물의 역할에 대하여 이야기를 나누고, 어떤 소품이 필요한지 알아보고 준비하여, 무대를 꾸미고 동화를 회상한 뒤 배역을 정하여 극화놀이를 하고, 극화놀이 활동 후에는 활동에 대하여 평가하는 활동이다. 극화놀이 활동을 유아에게 경험하게 하여 이러한 활동이 유아의 어휘력과 언어표현력 신장에 어떠한 영향을 미치는지에 대해 분석하였다.

PZT세라믹스에 있어서 길이진동모드의 온도안정성

이개명,현덕수 濟州大學校 産業技術硏究所 2001 산업기술연구소논문집 Vol.12 No.1

Temperature stabilities of dielectric constants and resonant frequencies of the substrates are very important in piezoelectric ceramics oscillators and filters. In this study. it was investigated temperature stability of the length-extensional vibration mode of Pb(Zr_(y)Ti_(1-y)O_(3)+x[wt%]Cr_(2)O_(3) ceramics. The mode can be utilized in fabricating ultra-small 455kHz IF devices. Addition of Cr_(2)O_(3) in morphotrophic phase PZT decreased the variations of dielectric constant. electro-mechanical coupling factor k_(31) and resonant frequency by thermal shock. As additive weight of Cr_(2)O_(3) increased. the temperature coefficient of resonant frequency changed from positive number to negative one. And the composition with zero temperature coefficient of resonant frequency was shifted to the one with increased Cr_(2)O_(3) additive weight by thermal aging.

Italian ryegrass의 秋季刈取가 牧草의再生, 炭水化物 蓄積 및 乾物收量에 미치는 影響

安桂洙 順天大學校 1983 論文集 Vol.2 No.1

本 試驗은 秋播 이탈리안라이그라스의 秋季刈取時期가 牧草의 再生, 炭水化物 蓄積 및 乾物收量에 미치는 영향을 究明하기 爲하여 圃場實驗을 遂行하였으며 結果를 要約하면 다음과 같다. 1.乾物收量은 刈取時期가 빠른 區일수록 높았고(P<0.05), 刈取時期가 제일 늦은 區는 無刈取區보다도 收量이 낮았다. 2. 乾物中 全水溶性炭水化物(TSC)의 含量은 一番刈取直後에 약간 떨어졌다가 再生長에 따라 점점 높아졌으며 二番刈取期에 가까울수록 다시 떨어졌다. 氣溫이 零下로 下降하기 1週日 前의 TSC含量水準은 그루터기, 줄기, 잎 別로 모두 共히 刈取時期가 빠른 區일수록 高水準이었으며 (P<0.01), 二番草의 乾物收量과의 사이에 相關이 成立되었다.(P<0.05) 3. 收量生長速度(CGR)는 平均氣溫이 8℃에서 下降할수록 떨어졌으며, 上昇할수록 높았다. 相對葉面積生長率(RLGR)과 純同化率(NAR)은 各區 共히 再生30日間이 가장 높았으며 再生後期에는 低下되었다. 葉面積指數(LAI)의 增大는 各區 共히 刈取後 50日까지는 빨랐으며 그 後에는 완만하였고 最大値의 節圍는 3.4∼5.8이었다. 또한 刈取後 70日까지의 LAI가 큰 區일수록 二番草의 乾物收量이 높았다. 4. 生長이 抑制되는 低溫期의 TSC, LAI, CGR, NAR 및 LWR와 二番草乾物收量과의 사이에 相關이 認定되었으며, 그 貢獻度는 LWR>LAI>TSC>NAR>CGR의 順이었다. This experiment was carried out to study the effect of the regrowth, the accumulated carbohydrate and dry matter yielding on the cutting time at the autumn in fall sowing Italian ryegrass. The results obtained were summarized as follows; 1. In dry matter yield, the plot of eariler cutting was shown the highest yielding(P<0.05), and that of the last cutting was shown the lower yielding of dry matter than that of the nonecutting plot. 2. TSC(Total water Soluble Carbohydrate) content in the dry matter slightly decreased directly after the first cutting and made gradual increase according to the regrowth of this crops and then decreased again to be coming on the second cutting time. In the TSC content levels at one week before falling to sub-zero temperature were all the high level in stubble, stem and leaf to the plot of eariler cutting(P<0.01), and there was significant correlation between the TSC content level and the dry matter yield of the second harvested grass(P<0.05). 3. CGR(Crop Growth Rate) was getting decreasing and increasing as the average temperature was falling and rising from 8℃. RLGR(Relative Leaf area Growth Rate) and NAR(Net Assimilation Rate) were both the highest during 30 days after regrowing, and lowered after regrowing in all the plots. LAI(Leaf Area Index) was shown a rapid increase during 50 days after cutting and then a slow increase in all the plots, and it's range of maximum value was 3.4-5.8. And also it was observed that dry matter yielding was high in the plots having a high LAI to 70 days after cutting. 4. It was recognized that there were significant correlation between TSC, LAI, CGR, NAR, LWR(Leaf weight Ratio) and dry matter yielding of the second harvested grass in the low temperature stage of making growth inhibition, and its degree of contribution was in order of LWR>LAI>TSC>NAR>CGR.

발음시 파장 및 기간의 변화에 관한 연구

千在植,鄭世賢 단국대학교 1994 論文集 Vol.28 No.-

Sound is the sensation produced when longitudinal variations of molecules in the external environment. ie, altenate phases of condensation and rarefaction of the molecules, strike the tympanic membrane. The purpose of speaking is communication between humans. It is very important for social life to speak and hear exactly. It there were problems to speak, it is very unconvenient for social life psychologically. The purpose of this experiment was to analyse the frequency and duration of pronunciation. Each 20 male and female who were living in Seoul and speaking standard Korean, had participated in this experiment. Each 10 male and female, who were wearing dentures and adapted at least over 1 years, had participated in this experiment also. The data were taken and analysed by Philips PM 3350A Storage Oscilloscope which had 68008 up microprocessor IEEE-488 interface. The results were as follows 1. High pitches were appeared in early stage of pronunciation in plosive sounds(ㅂ, ㅋ, ㅌ, ㅍ)and Y system vowel diphthorgs. 2. Condensation waves were seen in later stage of pronunciation in frictional sounds(ㅅ,ㅎ) and nasal sound(ㄴ, ㅁ). 3. the average data of frequency and duration were as follows ◁ 표 삽입 ▷ (원문을 참조하세요) 4. There were special pitches such as 111, 181, 200, 250, 333, 400, 500, 1000, 2000 Hz in all subjects

PZT세라믹스에 있어서 길이진동모드의 온도안정성

이개명,현덕수 제주대학교 산업기술연구소 2001 尖端技術硏究所論文集 Vol.12 No.1

Temperature stabilities of dielectric constants and resonant frequencies of the substrates are very important in piezoelectric ceramics oscillators and filters. In this study, it was investigated temperature stability of the length-extensional vibration mode of Pb(ZryTi1-y)O3 + x[wt%]Cr2O3 ceramics. The mode can be utilized in fabricating ultra-small 455kHz IF devices. Addition of Cr2O3 in morphotrophic phase PZT decreased the variations of dielectric constant, electro-mechanical coupling factor k31 and resonant frequency by thermal shock. As additive weight of Cr2O3 increased. the temperature coefficient of resonant frequency changed from prositive number to negative one. And the composition with zero temperature coefficient of resonant frequency was shifted to the one with increased Cr2O3 additive weight by thermal aging.

女子卓球選手들의 體型과 體力間의 關係

李啓暎,韓泰龍 全北大學校附設 스포츠科學硏究所 1987 논문집 Vol.- No.4

The objectives of this study were to study on the somatotype and physical fitness of woman table tennis players. For this purpose the writer surveyed the Heath-Carter Anthropometric somatotype method and physical fitness. The total 26 female athletes were selected and measured. The conclusion of this study were as follows : 1. The correlation coefficient between Endomorphy and power, and Muscular endurance were revealed as the certainly correlation. 2. The correlation coefficient between mesomorphy and muscular strength was revealed as the high correlation, Agility, power turn out certainly correlation. 3. The correlation coefficient between ectomorphy and power was revealed as the certainly correlation.

飼料作物의 輪作組合이 乾物收量, 土壤의 耐水性粒團率 및 窒素含量에 미치는 影響

安桂洙,趙聖均 順天大學校 1985 論文集 Vol.4 No.1

本 試驗은 飼料作物의 輪作組合이 建物收量, 土壤의 耐水性粒團率 및 室素含量에 미치는 영향을 究明하기 爲하여 夏節期飼料作物로 수단그라스계 잡종을 擇하고 冬節期飼料作物로 이탈리안 라이그라스, 호밀, 보리, 유채등을 擇하여 年間2期作∼3期作으로 6處理區 3反復 亂塊法으로 配置하여 圃場試驗을 遂行하였으며 얻어진 結果를 要約하면 다음과 같다. 1. 年間 乾物收量은 호밀과 수단그라스계 잡종을 輪作한 것이 가장 많았으며(P<0.01), 年間 2期作栽培가 3期作栽培 보다 有利하였다. 2. 土壤의 耐水性粒團率은 冬節期作付에서는 40%內外를 보이고 夏節期에는 35%內外를 보이고 있어 季節에 따른 差異는 多少 나타내지만 處理間의 有意性은 認定되지 않았다. 3. 土壤中의 T-N含量은 處理間의 有意性은 認定할 수 없으나 季節的 作付方式에서는 多少의 差異가 있었다. This experiment was carried out to investigate the effect of the rotational combination of forage cultivation on the dry matter yield, the water-stable aggregate rates and the nitrogen contents in the soil of the experiment field. The results obtained are summarized as follows; 1. In the annual dry matter yield, rye and sudangrass-hybrid plot was the highest(P<0.01), and the second crop system was higher than the third crop system. 2. The water-stable aggregate rates of the soil in the experiment field were about 40 %, 35% of winter and summer cropping system, respectively; however, no significant differences(p>0.05) between plots were observed. 3. In the total nitrogen contents in the soil of the experiment field, no significant differences(P>0.05)between plots, were noticed but there were somewhat differences in the winter cropping systems.