• Journal of Life Science
• /
• v.19 no.1
• /
• pp.58-64
• /
• 2009

This study was conducted to know the molting sequence and the aging points of flight feathers of steller's sea eagles (Haliaeetus pelagicus). For this study, two captive immature steller's sea eagles raised at the Ornithology Laboratory attached to Kyungsung University were surveyed for five years from Nov. 2000 to Nov. 2005. The survey indicated that the first molting began in July of the second year, and the primaries of P1-3, the secondaries of S18-19 (female), S17-18 (male), and S1 and S4 were replaced by one-time with second generation feathers. Generally molting stopped during the winter period, but a few feathers continued to molt during the winter. The two secondaries of S18-19 (female) and S17-18 (male) always molted every year but some of the juvenile secondaries (male: S10, S11, etc) retained for 2 or 3 years. In the molting order of primaries, the first molting started at P1 and it proceeded to P10 of outside. In the secondaries, the first molting started at S17(male) and S19(female), and it proceeded to outside. After that molting it started at S1 and proceeded to inside. In the other secondaries, the pattern of molting which proceeded in the mid-part of the secondaries was usually beginning in several different points at the same time. The molting seemed as if it depends on both the conditions of the individuals and the environment, so it was very difficult to explain the molting pattern in the mid-part of the secondaries. The longer quills (P7, P8) required for more than 68 days to develop. In the comparison of the length in the remiges between the first and the second generation feathers, the first generation feathers were the larger than that of the second. And the reduction of the length between the second and the third generation feathers was a few. The reduction of the length between the third and the fourth generation feathers was slight. The juvenile primaries were dark brown with a whitish base, which could be observed until the second or the third generation feathers (in their third or fourth winter plumage).

• Korean journal of applied entomology
• /
• v.16 no.1 s.30
• /
• pp.13-19
• /
• 1977

The smaller brown planthopper overwinters mostly as the fourth instar nymph. The emerged adult disperses to winter barley or wheat plants. The adult of the first generation disperses into the rice field, and spends three generations in the rice field. The population densities of the adults of the first generation and the overall density of the second generations are the most important in relation to the incidents of the rice stripe disease which is transmitted by this insects. This study was intended to analyse the population increases in these important generations in relation to the kind and the different growing stage of the host plants. The insects were reared on potted host plants of different growing stage in the insect cages. The population increases of the insects in the cages were compared with those on the rice seedlings in the laboratory. The results are as follows: 1. The average longevities of the adults of the generations were 13.4 days for the overwintered, 12.9 days for the first, and 10.2 days for the second generation, and showed no significant differences between the generations even they seemed to be shorter than normal condition probably caused by the frequent disturbance at the time of food renewal in 2 or 3 days. 2. When they were reared on the rice seedling, the average numbers of the eggs per female were 131.2 for the overwintered generation, 124.9 for the first generation grown on the barley, and 142.3 for the second generation grown on rice, and shelved no significant differences between the generations. More than $90\%$ of the eggs were laid within 3 weeks. 3. The hatchabilities of the eggs laid on the rice seedling in laboratory were $77.4\%$ for the first generation, $93.1\%$ for the second generation and $62.1\%$ for the third generation. The estimated hatchabilities of the eggs were $67.5\%$ for the first generation, $84.1\%$for the second generation, and $21.9\%$ for the third generation with the growing plants on the plots. The hatchability on the eggs laid by the adults infested on the barley on May 17 was $13.5\%$ compared with $67.5\%$ for the eggs laid by those infested on barley in late April. 4. The average total nymphal periods were 19.4 days for the first generation, and 13.3 days for the second generation in the laboratory and the mortalities of the nymphs seemed to related with the growing stages of the host plants. 5. With the pot experiments, the average per cents of the emerged adults were $37.2\%$ for the first generation, $55.3\%$ for the second generation, and $11.6\%$, for the third generation. The average numbers of the emerged adults were $7.4\%$ for the pots infested on the barley on May 17, instead of $37.2\%$ adults for those infested in late April. 6. From above results, it may suggest that the innate qualities of the insect are not significantly different between generations, and the differences in the increase of the population for the generations might effected considerably by the differences in the physiological conditions of tile host plant, besides the differences in physical and other biological factors.

• Journal of Environmental Science International
• /
• v.29 no.4
• /
• pp.403-413
• /
• 2020

The purpose of this study is to understand the formation of internal wind paths of open space and its effect on meteorological factors and the generation of negative air ions. Various types of internal wind paths of open space were formed. Subsequently, changes in meteorological factors in each type were measured and the generated negative air ions were analyzed. The four key findings of the study are summarized as follows. First, the average wind speed formed inside the open space was analyzed such that the difference in wind speed was dependent on the difference in the composition of the wind path. Second, the negative air ion generation was observed to have the same trend as the average wind speed difference. Third, changes to the meteorological factors were more evident depending on the difference in wind path formation patterns. Solar radiation was expected to be highly affected by the physical structure (direction) of the target site. The relative humidity was found to show large difference depending on the different wind path type; however, this difference was significantly reduced when converting to absolute humidity. Fourth, it was found that the wind path formation type of open space affects meteorological factors through path analysis, and the changed meteorological factors affect the amount of generated negative air ions. Two conclusions can be obtained based on these results. First, the changes in internal wind speed formation of open space directly reduced the amount of generated negative air ions. Second, the changes in wind speed affect meteorological factors as well as the amount of generated negative air ions.

• Journal of Ocean Engineering and Technology
• /
• v.34 no.6
• /
• pp.406-418
• /
• 2020

In this study, a nonlinear wave simulation code is developed using a higher-order spectral (HOS) method. The HOS method is very efficient because it can determine the solution of the boundary value problem using fast Fourier transform (FFT) without matrix operation. Based on the HOS order, the vertical velocity of the free surface boundary was estimated and applied to the nonlinear free surface boundary condition. Time integration was carried out using the fourth order Runge-Kutta method, which is known to be stable for nonlinear free-surface problems. Numerical stability against the aliasing effect was guaranteed by using the zero-padding method. In addition to simulating the initial wave field distribution, a nonlinear adjusted region for wave generation and a damping region for wave absorption were introduced for wave generation simulation. To validate the developed simulation code, the adjusted simulation was carried out and its results were compared to the eighth order Stokes theory. Long-time simulations were carried out on the irregular wave field distribution, and nonlinear wave propagation characteristics were observed from the results of the simulations. Nonlinear adjusted and damping regions were introduced to implement a numerical wave tank that successfully generated nonlinear regular waves. According to the variation in the mean wave steepness, irregular wave simulations were carried out in the numerical wave tank. The simulation results indicated an increase in the nonlinear interaction between the wave components, which was numerically verified as the mean wave steepness. The results of this study demonstrate that the HOS method is an accurate and efficient method for predicting the nonlinear interaction between waves, which increases with wave steepness.

• Fashion & Textile Research Journal
• /
• v.24 no.4
• /
• pp.418-430
• /
• 2022

This study aims to analyze consumers' purchase decision-making process of buying avatar fashion items on the Metaverse platform. Drawing on the connection between the self-expression tendency of the MZ generation and that of avatars in the Metaverse, this study uses a qualitative research method to analyze how consumers express their self-image through the appearance of their avatars. Unlike previous studies on the clothing purchase decision-making process, this study shows that purchasing and consumption behavior involve the following six stages: recognizing desire, collecting information, evaluating alternatives, making purchases, evaluating the consumption, and post-purchase action-taking. In the first stage of the purchase decision-making process, consumers' desire arises with self-image expression and confirmation. In the second stage, consumers have a high tendency to shop in the best item category. In the alternative evaluation stage, consumers tend to seek items that match their highest standard while considering their personal preferences. In the fourth stage, when making actual purchases, unplanned purchase behavior often occurs along with an active practice of alternative evaluation. In the fifth stage, the evaluation of the consumption shows that consumers achieve satisfaction by applying a style to their avatars that they are unable to try in the real world. In the last stage, consumers often use their purchases to communicate their various styles with other online consumers. Therefore, we conclude that the online purchase decision-making process differs from the offline process as it is divided into six stages.

• Animal Bioscience
• /
• v.36 no.3
• /
• pp.417-428
• /
• 2023

Objective: Few studies have genetically monitored chickens over time, and no research has been conducted on ducks. To ensure the sustainable management of key duck breeds, we used microsatellite markers to monitor Brown Tsaiya ducks over time genetically. Methods: The second, fourth, sixth to eighth generations of the Brown Tsaiya duck selected for feeding efficiency and control lines were included in this study to investigate the genetic variations, effective population size, population structure and the differentiation between populations over time with 11 microsatellite markers derived from Brown Tsaiya duck. Results: The results showed there were a slight decrease in the genetic variations and an increase in within-population inbreeding coefficient (F_IS) in both lines, but no consistent increase in F_IS was observed in each line. The effective population size in the second and eighth generations was 27.2 for the selected line and 23.9 for the control line. The change in allele richness showed a downward trend over time, and the selected line was slightly lower than the control line in each generation. The number of private alleles (N_p) in the selected line were higher than in the control line. Moderate differentiation was observed between the second and eighth generations in the selected line (F_ST = 0.0510) and the control line (F_ST = 0.0606). Overall, differentiation tended to increase with each generation, but genetic variation and structure did not change considerably after six generations in the two lines. Conclusion: This study provides a reference for poultry conservation and helps to implement cross-generation genetic monitoring and breeding plans in other duck breeds or lines to promote sustainable management.

• Korean journal of applied entomology
• /
• v.45 no.1 s.142
• /
• pp.97-100
• /
• 2006

Tipula nova appeared to have three generations a yew under the rearing conditions at room temperature. The first-generation with its eggs laid in April spent from 51 to 117 days, while the second-generation with its eggs laid in July spent from 57 to 93 days. The third-generation in which eggs were laid in September to grow until the following spring took 79 to 200 days. All the processes of life cycle of the species, when reared at room temperature from the spring to the summer with eggs deposited in the spring, were as follows: Eggs usually hatched between 7 and 10 days after oviposition. First instar larvae molted to the second instar in 7-10 days. Second instar larvae spent 7-12 days for next molting and third instar period lasted approximately 7-11 days. Fourth instar larvae spent 17-50 days for pupating. The duration of pupal stage was 3-6 days.

• Korean journal of applied entomology
• /
• v.40 no.2
• /
• pp.117-123
• /
• 2001

The occurrence and damage by the oriental fruit moth, Grapholita molesta (Busck) were investigated on pear trees from 1996 to 2000 in the Naju, Korea. The number of overwintering larvae in pear trees considerably varied depending on the maturation time of varieties. The density of overwintering larvae on late cultivars such as Gamcheonbae and Okusankichi was high, but relatively low on early cultivars. Trunk and main branch of pear trees were main overwintering sites. In 1997, overwintering larvae began to pupate from middle February, and to emerge from late March. Male moths were caught in the sex pheromone traps from late March until early October with four peaks of flight in 1996~2000. In every generation larvae damaged both the shoots and fruits of pear tree, but the first and second generation larvae tended to damage mainly shoots, while most of the injured fruits were due to the third and fourth generation larvae. In pear fruits damaged by fruit moths, most of these were caused by oriental fruit moth larvae and none of pear fruits were damaged by peach fruit moth or pear fruit moth larvae in 1998~2000.

• Human Ecology Research
• /
• v.55 no.2
• /
• pp.141-152
• /
• 2017

Recently, one-person households have surpassed nuclear families. One-person households are expected to have many problems with health due to an irregular life style and a tendency to be more isolated from society. In addition, we need to divide the generations and survey each generation due to differences in one-person household factors and characteristics as well as the unique physical conditions of each generation. Therefore, based on the sixth Korea National Health and Nutrition Examination Survey, this survey examined health behavior differences between one-person households and non-one-person households according to generation (respectively) as well as studied how one-person households and health behavior influence subjective health conditions. The major result of this survey is as follows. First, one-person households reveal a higher rate in the negative health behavior than non-one-person households. Second, the physical activity of all households reveals a high rate of non-activity. Third, health scores of one-person households are lower than that of non-one-person households; consequently, the analysis of health scores for one-person households and non-one-person households indicated that the middle age health scores for one-person households have been lowest in generations. Fourth, the factors that influence subjective health conditions indicated that one-person household and health behavior has meaningful influence; in addition, the subjective health condition of one-person households are lower than non-one-person households under controlled health behavior.

• The Journal of the Korea Contents Association
• /
• v.11 no.9
• /
• pp.174-186
• /
• 2011

This research addresses global status of Korean media firms and their future directions. Mapping of major international media firms all over the world is used in order to explain global status fully. In the four categories that classified media firms using Forbes Global 2000 mapping, all Korean media firms are included in the fourth group, which is the weakest in terms of global competitiveness. Therefore, it is essential to trace appropriate global strategy from the media industry value chain that has competence. This paper finds out that Korea has advantage in the contents, terminal, and next generation networks. That means alliance strategies of contents-terminal-next generation network have advantage to evolve into global media firms. Moreover, Korean media companies should adopt selection and concentration strategy in terms of geographical expansion. As Korea's broadcasting and game contents are already popular in Asian and Latin American regions, they would better to enter the emerging markets. In so doing, terrestrial broadcasters and game service providers should lead the way.