• Journal of Ocean Engineering and Technology
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• v.25 no.4
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• pp.1-6
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• 2011

The installation of a topside structure can be categorized into the following stages: start, pre-lifting, lifting, lifted, rotating, positioning, lowering, mating, and end of installation. The transfer of the module onto the floating spar hull occurs in the last three stages, from lowering to the end. The coupled multi-body motions are calculated in both calm water and in irregular waves with a significant wave height (1.52m). The effects of the hydrodynamic interactions between the heavy lifting vessel and the spar hull during the lowering and mating stages are considered. The internal forces caused by the load transfer and ballasting are derived for the mating phases. The results of the internal forces for the calm water condition are compared with those in the irregular sea condition. Although the effect of the pitch motion on the relative vertical motion between the deck of the floating structure and the topside module is significant in the mating phases, the internal force induced pitch motion is too small to have this influence. However, the effect of the internal force on the wave-induced heave responses in the mating phases is noticeable in the irregular sea condition because transfer mass-induced draught changes for the floating structure are observed to have higher amplitudes than the external force induced responses. The impacts of the module on the spar hull in the mating phase are investigated.

• Asian-Australasian Journal of Animal Sciences
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• v.20 no.1
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• pp.112-118
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• 2007

The present study was conducted to investigate the attributes of ram sexual behaviour under different social conditions. Six intact rams and eight overiectomized ewes were used in this experiment. Ewes were artificially brought into oestrus. All mating traits were recorded every 10 sec during a 1 h mating session under five social conditions viz., ram exposed to single oestrus ewe, ram exposed to single oestrus ewe and audience ram, ram exposed to multiple oestrus ewes, ram exposed to single oestrus ewe with competitor ram and ram exposed to multiple oestrus ewes with competitor ram. Mean intensity of the mating activities during the 1 h mating session under five social conditions was compared. Either vocalization or leg kicking was found to be the predominant teasing activity under all five conditions. Sniffing differed significantly (p<0.05) between different social conditions. Vocalization, leg kicking, and leg kicking with vocalization did not differ significantly (p<0.05) between different social conditions. Mounts/h in the multiple oestrus ewe condition was higher and differed significantly (p<0.05) from other social conditions. Ejaculations/h for the experimental ram was higher when exposed to multiple oestrus ewes in comparison to other social conditions. Mounts/ejaculation was low in the audience ram condition in comparison to the other four social conditions.

• Journal of Ecology and Environment
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• v.29 no.1
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• pp.49-53
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• 2006

The fiddler crab, Uca lactea, which lives on intertidal mudflats in Korea, exhibits both burrow mating and surface mating. We observed 17 cases of surface mating that occurred on Ganghwa Island, South Korea. Most surface-mating males did not build semidomes, structures that attract searching females for burrow mating. Based on the conclusion of a previous study that semidome building is condition-dependent, we suggest that food availability may influence the mating tactic of this species. In addition, there was a strong correlation between the carapace size of both sexes that surface-mated, which suggests that males use body size of females as a mating cue.

• International Journal of Industrial Entomology and Biomaterials
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• v.21 no.2
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• pp.189-191
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• 2010

The black soldier fly, Hermetia illucens, has a worldwide distribution in the tropics and warm temperate regions and is active in the Korea from May through October. This species colonize a wide variety of decomposing vegetable and animal matter and oviposits in a variety of decomposing materials. In this study, how the black soldier fly pupation, adult emergence and mating rate changed with season at the artificial rearing system was investigated. The black soldier fly larvae and pupae were reared under laboratory condition ($27^{\circ}C$, 60% R.H.). In this study, under the laboratory condition, pupation and adult emergence were not influenced by season, but the data shows definitely different mating numbers throughout whole year. The time of the day is changed with seasons and it influence to mating on artificial rearing. To culture the black soldier fly throughout the year in Korea needs a more deep study under the artificial rearing system.

• Transactions of the Korean Society of Mechanical Engineers
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• v.13 no.1
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• pp.48-58
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• 1989

An assembly modeling system, with which a designer can interactively create an assembly of components ready for the dynamic analysis, has been developed. In this system, an assembly model is created from the mating conditions between the components in the assembly, and then most information required for the dynamic or kinematic analysis packages are derived. For this development, the following problems have been solved; the creation of assembly data structure, the derivation of the joint information, the inference of each component's position, and the creation of the joint coordinate systems. Through this work, the designer can easily model an assembly by assigning mating conditions, and check the dynamic or kinematic performance with the automatic creation of inputs for the assembly analysis packages.

• Asian-Australasian Journal of Animal Sciences
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• v.18 no.4
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• pp.463-469
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• 2005

An attempt was made to analyze the factors affecting mating performance of rams in pen mating systems. Due to many types of social interactions, mating performance of rams may decrease or increase. Six intact Muzaffarnagari rams were used and divided into three dominant subordinate pairs by food and ewe competition test. For dominant rams subordinate ram became competitor and vice versa. In the first experiment, ram was exposed to ewe but the competitor ram was kept outside the pen with the facility of visibility only. In the second experiment each ram was exposed to ewe along with the competitor ram and in third experiment ram was exposed to ewes (two) along with competitor ram in observation pen. Recordings of different mating and agonistic behaviour were done in all the experiments. It was found that subordinate ram's mating behaviour was inhibited by mere presence of a dominant ram out side without physical contact. However, when ram exposed to oestrus ewe(s) along with competitor ram, both dominant and subordinate rams spent much of their time in guarding activities instead of mating. In addition dominant ram tried to curtail the subordinate ram mating by agonistic interaction like fight and butting. Different guarding activities were observed either as active or passive type depending on level of dominanace. It was concluded that in a limited space the interaction of two or more rams might affect the number of services adversely.

• Asian-Australasian Journal of Animal Sciences
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• v.10 no.2
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• pp.192-195
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• 1997

Thirty adults Desi and Khaki Campbell ducks were distributed to 6 farmers of Chakcharpur village of Mymensingh district. These ducks were subjected 3 types of mating e.g. Desi ${\times}$ Desi, Khaki Campbell ${\times}$ Khaki Campbell and Khaki Campbell ${\times}$ Desi-having 10 ducks (male : female = 1 : 4) in each mating group. Each mating group was then divided into two having 5 ducks(male : female = 1 : 4) and distributed to 2 farmers. After collecting eggs from each mating category, these were hatched by broody hens from which a total of 90 day old ducklings, 30 from each genotype were raised from birth to 90 days after the onest of laying. Although the weight of the day old chicks were similar in all genotypes (40-43 g), body weight was the highest (p <0.01) for Khaki Campbell ${\times}$ Desi (1,543) before the onset of laying followed by Khaki Campbell (1,552 g) and Desi (1,448 g) ducks. Khaki Campbell attained maturity at an earlier (p < 0.01) age (147 days) followed by Khaki Campbell ${\times}$ Desi, (154 days) and Desi (161 days) ducks. Khaki Campbell laid maximum (p < 0.01) number of eggs (46) compared to Khaki Campbell ${\times}$ Desi, (30) and Desi (18) ducks 90 days after the onset of laying. However, eggs were heavier (p < 0.01) in Desi (61.9) ducks compared to other genotypes. Fertility and hatchability were also higher in Desi ducks than the other two genotypes. Mortality was also lover in Desi ducks (3.33%) followed by Khaki Campbell ${\times}$ Desi (6.66%) and Khaki Campbell (16.66%) ducks. The results presented here indicated the superiority of Desi ducks over the other two genotypes with respect to egg weight, fertility, hatchability and mortality under village condition. Pure and crossbreds, on the other hand, were heavier at sexual maturity at relatively younger age and laid more eggs.

• Journal of Korean Institute of Industrial Engineers
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• v.29 no.1
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• pp.49-64
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• 2003

Although assembly sequence planning is an essential task in assembly process planning, it is known as one of the most difficult and time consuming jobs because its complexity is increased geometrically when the number of parts in an assembly is increased. The purpose of this study is to develop a more efficient algorithm for generating assembly sequences automatically. By considering subassemblies, a new heuristic method generates a preferred parallel assembly sequence that can be used in robotic assembly systems. A parallel assembly sequence concept provides a new representation scheme for an assembly in which the assembly sequence precedence information is not required. After an user inputs both the directional mating relation information and the mating condition information, an assembly product is divided into subgroups if the product has cut-vertices. Then, a virtual disassembly process is executed to generate alternate parallel assembly sequences with intermediate assembly stability. Through searching parts relations in the virtual disassembly process, stable subassemblies are extracted from translation-free parts along disassembling directions and this extraction continues until no more subassemblies are existed. Also, the arithmetic mean parallelism formula as a preference criterion is adapted to select the best parallel assembly sequence among others. Finally a preferred parallel assembly sequence is converted to an assembly BOM structure. The results from this study can be utilized for developing CAAPP(Computer-Aided Assembly Process Planning) systems as an efficient assembly sequence planning algorithm.

• Journal of Ecology and Environment
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• v.31 no.1
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• pp.1-7
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• 2008

In this minireview we focus on how males may exploit female's sensitivity to predation risk in the context of mating. It has been shown in studies on guppies and jumping spiders that in response to altered female behaviors, which are adaptations to the unfavorable environment and a consequence of females' higher sensitivity to predator's presence as well as females' higher predation risk, males can adopt condition-dependent mating tactics. It appears that in such cases males do not modify their reproductive behavior directly in response to their own perception of predation risk, but indirectly in response to changes in female behavior induced by predator presence. It has also been recently shown in crabs that males can exploit female behavior by creating safer habitat spots, which increases the male mating success. Hence all the evidence suggests that males not only respond to female sensitivity to the natural variation in predation risk, but that males can also exploit female behavior by altering the environment. As a logical extension of these findings, we present a hypothesis that in certain conditions males can manipulate the environment in order to increase the predation risk and to induce female behaviors that enhance the male's mating success with the increased predation risk. We propose that such a manipulation to increase predation risk is expected to evolve in males of species with a strong sexual conflict and female-biased predation risk. Although empirical evidence has not been yet shown, initial observations in a water strider species in Korea, Gerris gracilicornis, seem to support this hypothesis.

• Journal of Apiculture
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• v.33 no.4
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• pp.251-260
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• 2018

Instrumental insemination of honey bee is an attractive alternative to natural mating in breeding program as it allows mating crosses between desirable queen and specific drone. However, nursery condition that the queen is kept before and after insemination is major factor affected to the performance of instrumentally inseminated queen. In this study, we evaluated the influences of three different nursery-conditions of push-in cages, mini nuclei and normal colonies on number of spermatozoa stored in the spermatheca, body weight, onset of ovipositon and performance of instrumentally inseminated Apis cerana queen. Our results demonstrated that instrumentally inseminated queens kept in mini nuclei and in normal hives showed no significant difference in queen's weight (159.8 and 166.2mg, respectively), number of spermatozoa in spermatheca ($2.02{\times}10^6$ and $2.76{\times}10^6$, respectively), proportion of queen supersedure (33.3 and 66.7% queen survival at 11 months after oviposition, respectively) and brood production, compared to naturally mated queens. In contrast, instrumentally inseminated queens kept in push-in cages showed significant difference of those above data in comparison to queens mated naturally. Our results suggested that instrumentally inseminated queens could be kept in mini nuclei containing about 1.000 attendant bees to have desirable performance of queen whereas the push-in method should be practiced for the purpose of using queen in the length of time less than 7 months.