• ALGAE
• /
• 제25권1호
• /
• pp.17-26
• /
• 2010

The effects of salinity on various ecophysiological parameters of Ulva pertusa such as growth, nutrient uptake, photosynthetic performance and internal nutrient composition were tested. U. pertusa was collected from an eelgrass bed in a semi-protected embayment on the southwest coast of Korea. Under salinity regimes from 5 to 40 psu, the specific growth rates $(\mu)$ of U. pertusa ranged from 0.019 to $0.032\;d^{-1}$. Maximum growth rate was observed at 20 psu, and minimum at 40 psu. This species showed various uptake rates for nitrate and phosphate. Nutrient uptake was noticeably higher at intermediate salinity levels, and lower at both extremes. Salinity significantly influenced chlorophyll-$\alpha$ content and effective quantum yield. Tissue nitrogen content ranged from 1.5 to 2.9% N (dry weight), whereas tissue phosphorus ranged from 0.1 to 0.14% P (dry weight). The N : P ratio in the tissue of U. pertusa was considerably higher, ranging from 30 to 50. Increased growth at lower salinity suggests that the initial growth rate of U. pertusa is greater during the rainy season (i.e., late spring and early summer) than any other season during the year. The appearance of an Ulva bloom in eelgrass beds may be triggered by salinity more than by other environmental factors such as light and temperature.

• 한국치위생학회지
• /
• 제2권1호
• /
• pp.21-41
• /
• 2002

This study is designed to offer basic materials necessary for the instruction of effective clinical practices and the establishment of relationship with patients by means of making an analysis of the characteristics of patients affecting the behavior of students majoring in dental hygiene avoiding patients and countermeasures. With this in mind, the researcher worked with sophomores and juniors exposed to clinical practices during the period ranging from October 22, 2001 to November 9, 2001. The researcher came to the following conclusions on the basis of the findings of this survey. 1. The characteristics of patients influencing the behavior of avoiding them were categorized into appearance characteristics, personality characteristics, treatment-cooperative characteristics, and speech and behavior characteristics. Speech and behavior characteristics(4.26) turned out to be the most influential factor of all, which was followed by treatment-cooperative characteristics(3.68), personality characteristics(3.62) and appearance characteristics(3.42) in the right order. 2. The survey shows that foul breath and obnoxious oral(3.94) cavity were the worst factors of appearance characteristics and that using abusive language and being too aggressive(4.41) were the worst factors of personality characteristics. The study reveals that not putting faith in trainees(4.02) was the highest factor of treatment-cooperative characteristics and that using abusive language(4.50) was the highest factor of speech and behavior characteristics. 3. There was a significant positive relation between the domains of the characteristics of avoiding patients. The study indicates that the more subjects avoided the characteristics of patients, the more they avoided appearance characteristics(r =.444, p<.001) and that the more subjects avoided treatment-cooperative characteristics, the more they avoided appearance characteristics(r=.324, P<.001) and personality characteristics(r=.691, p<.001), and that the more they avoided speech and behavior characteristics, the more they avoided appearance characteristics(r=.265, p<.001) and personality characteristics (r=.531, p<.001). 4. The study shows that there was a significant difference between appearance characteristics and the growth areas of the subjects(p<.05) and that there was a significant difference between the satisfaction of clinical practices(p<.05) and health status(p<.05) in terms of personality characteristics. 5. The subjects avoided preschoolers, whose age ranged from 4 to 6(33.5%), most and avoided boys(71.4%) more than girls. They avoided those who were bereft of jobs(62.9%). And they avoided handicapped persons most in terms of special patients and avoided infant patients(31.0%). 6. The subjects turned out to have negative and passive countermeasures against those patients that had ever been avoided. So the researcher would like to suggest that theoretic education and training programs should be conducted in this respect by incorporating this mailer into the hygiene curriculum.

• Asian Journal of Innovation and Policy
• /
• 제5권3호
• /
• pp.275-292
• /
• 2016

Many countries set growth engine technologies and industries for economic growth and job creation. Each country always wants to know their technological or industrial position in the world in these industries. This study aims at identifying the worldwide position of 19 growth engine industries defined in Korean government. The methods are quantitative by counting the number of startup companies in the world. The ORBIS database was used to extract the number. Therefore, this article may be the first research for the world appearance of growth engine industries and its comparison between world and G7, and between G7 countries. Also, this may be the first study using the ORBIS database on the analysis of certain technology industries. Further, we showed a method to identify world features of technology industries.

• 대한치과교정학회지
• /
• 제19권3호
• /
• pp.99-111
• /
• 1989

To study the sexual maturity at puberty and interrelation between pubertal growth peak and sexual maturity, 68 malocclusions (female 44, male 24) were longitudinally studied for 4 years and cross-sectional samples of 210 malocclusions were studied together. The pubertal growth peak was determined by stature increment and sexual maturity was studied using developmental stages of pubic hair and breast, menarche in female and those of pubic hair in male. The following results were obtained. 1. Mean age at menarche was 12.8 years and it was 11.8 months later than PHV. 2. At pubertal growth peak, developmental stage 2 (54.2%) and 3 (29.2%) of pubic hair were most in male, and stage 1 (72.7%) and 2 (20.5%) were most in female. 3. At pubertal growth peak, the developmental stage 2 (50%) of breast was most and the stage 3 (43.2%) was next. 4. In interrelation between skeletal growth and sexual maturity, PHV had most high correlation with menarche and stage 3 of breast, and menarche had most high correlation with stage 3 of breast. 5. Appearance of remarkable sexual maturity suggested that the PHV was passed already.

• 한국환경농학회지
• /
• 제24권2호
• /
• pp.185-190
• /
• 2005

일부 농가에서 이용하고 있는 기능성 쌀 생산 농자재인 게 껍질, 견운모 및 숯 분말의 시용이 벼의 생육, 수량 및 쌀의 품질에 미치는 영향을 구명하고자 본 실험을 실시하였다. 게 껍질 분말 시용구는 다른 처리에 비하여 분얼수, 이삭수, 엽면적지수, 식물체의 질소함량을 증가시켰으나 등숙율은 낮았고, 백미수량은 차이가 없었다. 미질은 게 껍질 분말 시용구에서 완전미 비율과 Toyo 식미치는 낮았고, 분상질미 비율, 단백질 함량은 높았다. 견운모와 숯 분말 처리는 벼의 생육, 수량 및 수량구성요소, 쌀의 품질은 무처리와 차이가 없었고, 단백질 함량는 무처리보다 높았으나 Toyo 식미치는 낮았다.

• 한국해양공학회지
• /
• 제3권2호
• /
• pp.125-137
• /
• 1989

To check technical improvement in the soundness and strength of 12% Cr steel rotor, a 25 tons of rotor with 65 tons of ingot was made in real size and was cut to pieces to take test samples, and the various mechanical tests such as impact, tensile, creep, and fatigue were carried out. The strengths are compared with those of 1% Cr-Mo-V rotor of same size. Microstructures of the samples are examined and reviewed. The results can be summarized as follows. 1) Fracture appearance transition temperatures are 80.deg. C at the center part and 60.deg. C near surface of 12% Cr rotor, and 8.deg. C near surface of 1% Cr-Mo-V rotor. 2) Comparative rapid softening occurs at higher temperatures above 600.deg. C for 12% Cr steel and 550.deg. C for 1% Cr-Mo-V steel in tension tests. 3) Fatigue crack propagation rate of 12% Cr steel is almost same as that of 1% Cr-Mo-V steel at the same corresponding surface part of the rotors. The crack growth rate of center part of 12% Cr rotor is faster than near surface part of the rotor, and the crack growth rate at the load condition of R=0.04 is slower than that of the load condition of R=0.5 for both 12% Cr steel and 1% Cr-Mo-V steel. 4) Crack growth rate of radial direction near surface of 12% Cr rotor is faster than that of transverse direction at the same part because of the difference in residual stresses. 5) Both creep and fatigue strengths of 12% Cr steel are superior to those of 1% Cr-Mo-V steel and the difference is thought the effect of climb and glide controlled creep by solid solution of alloying elements and dispersion of carbides.

• 한국해양공학회지
• /
• 제3권2호
• /
• pp.625-625
• /
• 1989

To check technical improvement in the soundness and strength of 12% Cr steel rotor, a 25 tons of rotor with 65 tons of ingot was made in real size and was cut to pieces to take test samples, and the various mechanical tests such as impact, tensile, creep, and fatigue were carried out. The strengths are compared with those of 1% Cr-Mo-V rotor of same size. Microstructures of the samples are examined and reviewed. The results can be summarized as follows. 1) Fracture appearance transition temperatures are 80.deg. C at the center part and 60.deg. C near surface of 12% Cr rotor, and 8.deg. C near surface of 1% Cr-Mo-V rotor. 2) Comparative rapid softening occurs at higher temperatures above 600.deg. C for 12% Cr steel and 550.deg. C for 1% Cr-Mo-V steel in tension tests. 3) Fatigue crack propagation rate of 12% Cr steel is almost same as that of 1% Cr-Mo-V steel at the same corresponding surface part of the rotors. The crack growth rate of center part of 12% Cr rotor is faster than near surface part of the rotor, and the crack growth rate at the load condition of R=0.04 is slower than that of the load condition of R=0.5 for both 12% Cr steel and 1% Cr-Mo-V steel. 4) Crack growth rate of radial direction near surface of 12% Cr rotor is faster than that of transverse direction at the same part because of the difference in residual stresses. 5) Both creep and fatigue strengths of 12% Cr steel are superior to those of 1% Cr-Mo-V steel and the difference is thought the effect of climb and glide controlled creep by solid solution of alloying elements and dispersion of carbides.

• 한국수정란이식학회지
• /
• 제30권1호
• /
• pp.65-71
• /
• 2015

The aim of this study was to determine the relationship between the coat color appearance of Korean brindle cattle and the changes of relevant hormone levels that may affect the hair pigmentation during different stages of growth and maturation. In mature cattle, levels of both ACTH and DHEA in Korean brindle cattle with brown color were significantly higher than those with black color (p<0.05). Levels of ${\alpha}$-MSH in Korean brindle cattle with whole brindle ($${\geq_-}50%$$) color were significantly higher than those with brown color (p<0.05). In calves of Korean brindle cattle at 2 to 6 months, the concentration of estradiol was significantly higher in calves with whole brindle color than those with part brindle color (p<0.05), when the coat color was confirmed. After 6 month of coat color confirmation, levels of testosterone and ACTH increased in calves with part brindle color and were significantly higher than those with whole brindle color (p<0.05). In calves of Korean brindle cattle at 1 or 2 months, there were no significant differences in hormone levels of estradiol, ACTH, DHEA and ${\alpha}$-MSH between the calves with brindle color and brown color, except estradiol before brindle color appearance. Changes of relevant hormone levels at different stage of growth and maturation may affect the pigmentation of coat during the development of cattle. In addition to the current study correlating the different coat colors with relevant hormone levels, investigation of the coat color associated genes expressed in Korean brindle cattle may further clarify the mechanisms of coat color changes during their development.

• Agricultural and Biosystems Engineering
• /
• 제1권1호
• /
• pp.22-29
• /
• 2000

The development of bio-response feedback control system known as the speaking plant approach has been a challenging task for plant production engineers and scientists. In order to achieve the aim of developing such a bio-response feedback control system, the primary concern should be to develop a practical non-invasive technique for monitoring plant growth. Those who are skilled in raising plants can sense whether their plants are under adequate water conditions or not, for example, by merely observing minor color and tone changes before the plants wilt. Consequently, using machine vision, it may be possible to recognize changes in indices that describe plant conditions based on the appearance of growing plants. The interpretation of image information of plants may be based on image features extracted from the original pictorial image. In this study, the performance of a finite element retina was optimized by a genetic algorithm. The optimized finite element retina was evaluated based on the performance of neural plant growth monitor that requires input data given by the finite element retina.

• 한국군사과학기술학회지
• /
• 제6권4호
• /
• pp.73-79
• /
• 2003

Fatigue test is conducted to see the effect of pre-indentation on the fatigue crack retardation of Al5052-H18 plate. Metallographic observation is introduced to deduce the relationship between fatigue crack retardation and fracture appearance with indentation. The grain size of the specimen becomes smaller with the increase of indentation force and the plastic zone is formed with the decrease of grain size. The fatigue striations are appeared densely as the Indentation force becomes higher. Metallographic observation and fatigue test results show that the indentation force has the limited value in improving fatigue crack retardation. Important point to retard the fatigue crack growth is that the crack growth path should pass through the indented area.