• Ocean and Polar Research
• /
• 제30권1호
• /
• pp.11-19
• /
• 2008

Incubation routine and sex role of Streaked Shearwaters Calonectris leucomelas at Sasudo Island, in Jeju, South Korea, were studied during the incubation period, June to August in 2002. Incubation routine in Procellariiformes represents a sequence of alternating shifts taken in turn by female and male in a species-specific pattern. Hence, coordination of individual incubation rhythms between partners is crucial for successful breeding attempt. In Streaked Shearwaters, incubation routine represents a sequence of alternating shifts taken in turn by male and female. The first incubation shift was made by male after female had laid the egg. The mean incubation period was 50.8 days until hatching. Males had spent on average 26.5 days incubating and females 24.3 days accordingly. The mean duration of incubation shifts decreased progressively from 6th and 7th shift to hatching. Overall, males had spent more time incubating than females during the incubation period, but the mean duration of the incubation shift 5.6 days for males and 5.7 days for females did not differ between males and females. There were no effect of the body size of the breeding pair on incubation performance. For males the mean of body weight decreased during the incubation, whereas for females it remained approximately stable. In Streaked Shearwaters, the duration of incubation shift and subsequent foraging trip are related to loss of body weight during the period of fasting. In addition, coordination of individual incubation rhythms affects their incubation behaviour.

• 천문학회지
• /
• 제33권2호
• /
• pp.89-95
• /
• 2000

As an efficient method to detect blending of general gravitational microlensing events, it is proposed to measure the shift of source star image centroid caused by microlensing. The conventional method to detect blending by this method is measuring the difference between the positions of the source star image point spread function measured on the images taken before and during the event (the PSF centroid shift, ${\delta}{\theta}$c,PSF). In this paper, we investigate the difference between the centroid positions measured on the reference and the subtracted images obtained by using the difference image analysis method (DIA centroid shift, ${\delta}{\theta}$c.DIA), and evaluate its relative usefulness in detecting blending over the conventional method based on ${\delta}{\theta}$c,PSF measurements. From this investigation, we find that the DIA centroid shift of an event is always larger than the PSF centroid shift. We also find that while ${\delta}{\theta}$c,PSF becomes smaller as the event amplification decreases, ${\delta}{\theta}$c.DIA remains constant regardless of the amplification. In addition, while ${\delta}{\theta}$c,DIA linearly increases with the increasing value of the blended light fraction, ${\delta}{\theta}$c,PSF peaks at a certain value of the blended light fraction and then eventually decreases as the fraction further increases. Therefore, measurements of ${\delta}{\theta}$c,DIA instead of ${\delta}{\theta}$c,PSF will be an even more efficient method to detect the blending effect of especially of highly blended events, for which the uncertainties in the determined time scales are high, as well as of low amplification events, for which the current method is highly inefficient.

• Journal of Ecology and Environment
• /
• 제45권3호
• /
• pp.130-142
• /
• 2021

Background: Climate change is occurring rapidly around the world, and is predicted to have a large impact on biodiversity. Various studies have shown that climate change can alter the geographical distribution of wild bees. As climate change affects the species distribution and causes range shift, the degree of range shift and the quality of the habitats are becoming more important for securing the species diversity. In addition, those pollinator insects are contributing not only to shaping the natural ecosystem but also to increased crop production. The distributional and habitat quality changes of wild bees are of utmost importance in the climate change era. This study aims to investigate the impact of climate change on distributional and habitat quality changes of five wild bees in northwestern regions of Iran under two representative concentration pathway scenarios (RCP 4.5 and RCP 8.5). We used species distribution models to predict the potential range shift of these species in the year 2070. Result: The effects of climate change on different species are different, and the increase in temperature mainly expands the distribution ranges of wild bees, except for one species that is estimated to have a reduced potential range. Therefore, the increase in temperature would force wild bees to shift to higher latitudes. There was also significant uncertainty in the use of different models and the number of environmental layers employed in the modeling of habitat suitability. Conclusion: The increase in temperature caused the expansion of species distribution and wider areas would be available to the studied species in the future. However, not all of this possible range may include high-quality habitats, and wild bees may limit their niche to suitable habitats. On the other hand, the movement of species to higher latitudes will cause a mismatch between farms and suitable areas for wild bees, and as a result, farmers will face a shortage of pollination from wild bees. We suggest that farmers in these areas be aware of the effects of climate change on agricultural production and consider the use of managed bees in the future.

• 한국직업건강간호학회지
• /
• 제8권1호
• /
• pp.22-41
• /
• 1999

This study intended to analyze the health promoting behaviors, compare their factors according to the shift pattern of duties of women workers who were working in the industrial workplace and present basic data in planning systematic and effective programs of health promotion for three-shift system and day-duty. Using Quota Sampling, 219 women workers were selected as subjects from 5 workshops which had 50 settled workers up to 300 and 10 factories which had more than 300 located in Taegu and Kyung-Book Province. Data were collected by means of questionnaire from September 12 to September 30, 1998. As the instruments of the study were used Health Promotion Lifestyle Profile(HPLP) which was adapted and adjusted by Seo, Y. O. for health promoting behavior, the one developed by Moon, J. S. (1990) for health-belief, the one developed by Sherer et al.(1982) and then adapted by Oh, H. S. for self-efficacy, and the one developed by Park, J. W. (1985) for social support. The analysis of data were performed with Cronbach's ${\chi}^2$-test, t-test, ANCOVA, Kendal tau, Pearson correlation, Stepwise Multiple Regression test using SPSS program. The results of the study are as follows : 1. There was a significant difference in age(${\chi}^2=32.46$, p=0.000), career (${\chi}^2=18.47$, p=0.000), working day(t=-3.18, p=0.000) by the shift pattern of duties in terms of socio-demographic characteristics. 2. There was a statistically significant difference between the two groups on the health promoting behaviors (t=2,52, p=0.012). The score of three-shift group on health promoting behaviors was 2.27, showing that it was lower by .13 than that of day-duty group(2.40). 3. ANCOVA involving age, career and working day as covariables, which had revealed significant difference before, showed that health promoting behaviors by the shift patterns of duties was significantly different(F=4.88, p=0.028). 4. In consideration of variables that have an influence on health promoting behavior by the shift pattern of duties, social support occupied 19.4% of health promoting behavior in the three-shift group and 22.5% including the sense of self-efficacy. In the day-duty group, social support occupied 34.4% of health promoting behavior. 5. The score of three-shift group(2.94) was significantly lower than that of day-duty group(3.12) in the perceived benefit of health-belief(t= -3.29, p=0.001), while the score of three-shift group (2.48) was significantly higher than that of day-duty group(2.24) in the perceived barrier (t=4.22, p=0.000). In the sense of self-efficacy(t=-4.20, p=0.000), the score of three-shift group(3.24) was significantly lower than that of day-duty group(3.53) while in social support(t=-4.56, p=0.000) the one of three-shift group(2.64) was significantly lower than that of day-duty group(2.88). The suggestions are as follows on the basis of the results of this study : 1. It is required to develop health promoting program that takes the shift pattern of duties of women workers into consideration. In addition, there are special demands on developing nursing strategies for health promoting behavior of three-shift workers. 2. It is required to develop specific strategies for social support which is the most significant factor to the health promoting behavior for women workers. 3. It is necessary to develop some programs for improving the sense of self-efficacy, social support, and health-belief of three-shift workers. To achieve these tasks, industrial nurses should play an active role and improve the ability of self-health care of women workers.

• 비교문화연구
• /
• 제33권
• /
• pp.385-406
• /
• 2013

This research starts based on the assumption that the changes of educational system in China which had been caused by accepting western educational system in the late Qing Dynasty and the early Republic of China are indeed considered as a paradigm shift of educational system in China, This research aims first to investigate what kinds of problems and changes Chinese educational system confronted at that time and second to examine what kinds of implications such changes and problems of paradigm shift may have today in China. In order to achieve the goals of this research, I first researched changes and characteristics of educational paradigm shift occurred in the history of China. On the basis of those findings, I tried to analyze acculturation problems of Chinese educational system for that of western countries at that time, their implications in present time Chinese educational system, and the possibility of further paradigmatic shift in present Chinese education. In this paper, I assumed three historical paradigmatic shifts in educational system in China which had big influences on the foundation of Chinese education, such as the introduction of Confucian Thoughts, the introduction of Civil Examination System in Sui Dynasty, and lastly the introduction of western educational system in the late Qing Dynasty. The last paradigmatic shift occurred by the introduction of western education system into China was very different from the previous two paradigmatic shifts in China in that it was literally initiated by the world with cultures different from those of China, and that's why it is called Spatial Collision. It was also one of the many changes China had been forced to confront unvoluntarily. It was done for many other complicated factors such as the greed of western imperialistic countries, spreading of Christianity and missionary education, domestic resistance against long feudal reigning of Qing Dynasty, and lastly the intellect's eagerness for new knowledge and new ways of thinking. What is surely regretful for the paradigmatic shift of Chinese educational system was that it had been triggered by those many heterogeneous factors, thereby leading to such a sudden, entire and complete shift of Chinese education system. In addition, it was done without a deeper and further consideration of Chinese education system with thousand years of tradition. This situation could be understood to be an impetus strong enough to encourage the advent of a new paradigm propelled by rapid economic growth of China, many problems of western education system, reconsideration of Chinese tradition, and strengthening of women power in China, etc.

• 한국수소및신에너지학회논문집
• /
• 제26권5호
• /
• pp.423-430
• /
• 2015

$Cu/ZnO/Al_2O_3$ catalysts for water gas shift (WGS) reaction were synthesized by co-precipitation method with the fixed molar ratio of Cu/Zn/Al precursors as 45/45/10. Copper and zinc precursor were added into sodium carbonate solution for precipitation and aged for 24h. During the aging period, aluminum precursor was added into the aging solution with different time gap from the precipitation starting point: 6h, 12h, and 18h. The resulting catalysts were characterized with SEM, XRD, BET surface measurement, $N_2O$ chemisorption, TPR, and $NH_3$-TPD analysis. The catalytic activity tests were carried out at a GHSV of $27,986h^{-1}$ and a temperature range of 200 to $400^{\circ}C$. The catalyst morphology and crystalline structures were not affected by aluminum precursor addition time. The Cu dispersion degree, surface area, and pore diameter depended on the aging time of Cu-Zn precipitate without the presence of $Al_2O_3$ precursor. Also, the interaction between the active substance and $Al_2O_3$ became more stronger as aging duration, with Al precursor presented in the solution, increased. Therefore, it was confirmed that aluminum precursor addition time affected the catalytic characteristics and their catalytic activities.

• 한국인터넷방송통신학회논문지
• /
• 제23권6호
• /
• pp.55-60
• /
• 2023

컴퓨터로 두 이진수 m과 r의 곱셈 m×r=p을 수행함에 있어 시간이 과다 소요되는 곱셈을 전혀 수행하지 않고 단지 덧셈과 우측 자리이동만을 수행하는 방법으로 자리이동-덧셈법이 있다. SA는 승수 r의 자리 수 r_i가 0이면 m×0=0으로 결과 값 p를 우측 자리이동만 하면 되며, r_i가 1이면 m×1=m으로 결과 값 p=p+m을 수행하고, p를 우측자리이동하면 되는 매우 단순한 방법이다. SA에서 SR 횟수는 더 이상 단축시킬 수 없으며, 단지 개선부분은 덧셈 횟수 단축 여부이다. 본 논문에서는 인간이 수행하는 방식인 10진수를 기준으로 보다 작은 수를 r로 설정하는 경우에 비해 컴퓨터가 처리할 이진수로 변환시켰을 때 1의 개수가 보다 작은 수를 r로 설정하는 방법이 덧셈 횟수를 크게 줄일 수 있다는 점에 착안하여 덧셈 최소화 SA 방법을 제안하였다. 제안된 알고리즘을 [-127,128] 범위에서 일부 숫자를 대상으로 부호가 (-,-), (-,+), (+,-), (+,+)인 4가지 경우에 대해 덧셈 횟수를 비교하였다. 실험 결과 얻은 결론은 m과 r을 결정할 때 10진수가 아닌 2진수로 판단해야 함을 보였다.

• 청정기술
• /
• 제29권1호
• /
• pp.39-45
• /
• 2023

To investigate the effects of Mg addition at different aging times and temperatures, Cu/MgO/Al₂O₃ catalysts were synthesized for the low-temperature water gas shift (LT-WGS) reaction. The co-precipitation method was employed to prepare the catalysts with a fixed Cu amount of 30 mol% and varied amounts of Mg/Al. Synthesized catalysts were characterized using XRD, BET, and H₂-TPR analysis. Among the prepared catalysts, the highest CO conversion was achieved by the Cu/MgO/Al₂O₃ catalyst (30/40/30 mol%) with a 60 ℃ aging temperature and a 24 h aging time under a CO₂-rich feed gas. Due to it having the lowest reduction temperature and a good dispersion of CuO, the catalyst exhibited around 65% CO conversion with a gas hourly space velocity (GHSV) of 14,089 h-1 at 300 ℃. However, it has been noted that aging temperatures greater or less than 60 ℃ and aging times longer than 24 h had an adverse impact, resulting in a lower surface area and a higher reduction temperature bulk-CuO phase, leading to lower catalytic activity. The main findings of this study confirmed that one of the main factors determining catalytic activity is the ease of reducibility in the absence of bulk-like CuO species. Finally, the long-term test revealed that the catalytic activity and stability remained constant under a high concentration of CO₂ in the feed gas for 19 h with an average CO conversion of 61.83%.

• 한국콘텐츠학회:학술대회논문집
• /
• 한국콘텐츠학회 2006년도 추계 종합학술대회 논문집
• /
• pp.499-502
• /
• 2006

H.264/MPEG4 Advanced Video coding joint standard 에서 복호기(디코더)의 디블럭킹 필터는 필요하다. 본 논문에서는 MPEG-4 비디오에서 낮은 비트율과 대역폭에서도 화질을 보장하는 개선된 디블럭킹 알고리즘을 제안한다. 제안된 디블럭킹 알고리즘은 간단한 shift, addition 그리고 comparison 만을 사용하기 때문에 복잡성이 줄어든다. 블록 왜곡의 유무를 판별하기 위해 마스크 블록의 경계강도를 구해 복잡영역, 중간영역 그리고 단순영역으로 분리해 처리한다 실험 결과, 본 논문에서 제안한 디블럭킹 알고리즘은 블록 왜곡이 줄어드는 것을 알 수 있다.

• 한국수산과학회지
• /
• 제44권1호
• /
• pp.37-44
• /
• 2011

We investigated the optimum formulation to improve the gelling ability of squid, Dosidicus gigas, surimi. The solubility of minced squid muscle was highest at pH 10.7, and lowest at pH 5.0. The yields of conventional surimi and protein recovery after alkaline pH-shift processing were $68.1{\pm}2.4%$ and $65.3{\pm}2.6%$, respectively, whereas the protein recovery with acidic pH-shift processing was only $21.2{\pm}1.6%$. The addition of 5% starch decreased the breaking force regardless of the kind of starch, while the mixture of corn, potato, and wheat starch (total 15%) increased the breaking force by up to 1.9 fold. The addition of 5% egg white, 5% porcine plasma protein, 0.3% $CaCl_2$, and 0.3% Polymix GA significantly increased the breakingforce (P<0.05). None of the ingredients examined in this study significantly affected the deformation value (P<0.05). The optimum concentrations of egg white and $CaCl_2$ to obtain a breaking force of 55 g and a whiteness of 70 were 2.69% and 0.22%, respectively.