• The Korean Journal of Malacology
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• v.32 no.2
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• pp.133-139
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• 2016

The incubation time required for hatching of O. ocellatus were investigated through the processes of egg and embryonic developments by the dissecting microscopic and visual observations. And differences in ecological characteristics of the plankton mode of life or the benthic mode of life according to total numbers of the suckers on each short arm of the hatched juvenile larvae of O. ocellatus were studied by comparisons with other octopodidae species. Compared with the recent a few results reported by other researchers associated with the incubation time required for hatching by female adult mother of O. minor (73-90 days after spawning at $20.9-21.5^{\circ}C$ ranges), in this study, the incubation time required for hatching by female adult mother of O. ocellatus was 56-57 days after spawning at $11.0-20.4^{\circ}C$. Therefore, the incubation time required for hatching by female adult mother varied with Octopodidae species. In this studies, each ovarian egg laid by a female was connected to an egg string attaching to the surface of the wall or bottom of vacunt shell of Rapana venosa. Egg and embryonic developments of this species were studied in the indoor aquaria, in the specific gravity ranging 1.024-1.025. the hatched juvenile of O. ocellatus is 10.3 mm in the mean total length and 4.5 mm in mantle length, and each of its short arms has 18-20 suckers. The just hatched juvenile larvae of O. ocellatus enter the benthic mode of life (benthic larval stage) after hatching. In particular, regarding differences in ecological characteristics of the mode of life according to total numbers of the suckers, O. vulgaris may not need to have many suckers because they enter the planktonic mode of life after hatching, however O. ocellatus may need to have many suckers, because they should adapt to the benthic mode of life. And also the just hatched juvenile larvae of O. minor (bearing many suckers more than O. ocellatus) enter the benthic mode of life (benthic larval stage) after hatching. Therefore, the total number of the suckers on each short arm of the hatched juvenile larvae can be used for determining whether an octopus species has planktonic larval stages or benthic larval stage (benthic mode of life). In particular, The intracohort cannibalism phenomena appeared at the hatched juvenile larval stage because the larval stage of O. ocellatus and O. minor enter into the benthic larval stage in the early stage, unlike entering into the plaktonic larval stage in other Octopus species such as O. vulgaris: at this time, the early hatched larvae fed the late hatched larvae (they are the same species and almost same ages). Therefore, the intracohort cannibalism pheneomena occur in the just hatched juvenile stage of only O. ocellatus and O. minor.

• Korean journal of applied entomology
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• v.59 no.2
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• pp.133-138
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• 2020

In 2016, the two-spotted cricket was approved as a general food ingredient by the Korean Ministry of Food and Drug Safety. Additionally, the two-spotted crickets have high protein content (60%) and can be reared throughout the year even during the overwintering period. In this study, storage conditions were set in case cricket breeding was not possible due to problems such as breeding space and labor costs, and selection oviposition mats to determine high fecundity rates and low cannibalism rates for the eggs were investigated. The oviposition mat was mostly composed of soil (p < 0.05). Less than 62 crickets per 10 litters were found to be best suited for 1 day of spawning, based on the cannibalism rate of the eggs during the egg laying period. The results from the hatched eggs indicated that the hatching extended 12 to 14 days, and the best hatching rate was approximately 85% when stored at low temperatures(16℃) for 10 days. An efficient production proposed method that established the best oviposition mat and egg storage method for the cricket.

• Journal of Popular Narrative
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• v.25 no.3
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• pp.181-209
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• 2019

The purpose of this article is to compare zombie narratives in relation to the Other. In previous research, the view of zombies as post-capitalist soulless consumers or workers has been frequently expressed. But in this article, I wanted to look at zombies as the main cause of the collapse of the world and a new future. First, zombies do not only mean the representation of the consumer in the late capitalist era. Rather, it is an awakening subject desiring the outside of the system. As you can see from the Uncanny's point of view, zombies are something that we should oppress as freaks and monsters that threatened the Other. To be a zombie in this way is to meet one's other self, the "Fundamentals of Humanity," and it is the moment when everything becomes the subject ex nihilo, the new beginning. Second, the concept of infection shows a new ethic. Zombie cannibalism is different from the selfish love of a vampire who sucks a worker's blood. Zombie cannibalism is an infection, which is a model of Christian love for one's neighbor. It is a moment of awakening and the beginning of solidarity. It is on the waiting for the solidarity that the zombie hangs in such a way, and the attack on the human being is an active illusion. Third, the situation of the end of a zombie narrative is another event for newness. The anger of a zombie serves not just to show monsters, but acts as a catalyst that accelerates the world's catastrophes. The anger of zombies is the messianic violence that stops the false world, and presents a new way. The emergence of zombies and the popular response to them embody a desire for the possibility of a new subject and world.

• International Journal of Industrial Entomology and Biomaterials
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• v.31 no.1
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• pp.20-24
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• 2015

Increased use of rhinoceros beetles (Allomyrina dichotoma ) for food and medicine, and their elevated value as pets has led to an increase in the number of their breeding farms. Mass breeding of the insects in these farms leads to entomological diseases. In this study, we investigate cannibalism resulting from overcrowded breeding of A. dichotoma larvae, as well as secondary fungal infections in epidermal wounds in the surviving larvae. Some of the fungi detected in the present study showed entomopathogenicity, and the larvae showed different times of death. In particular, larvae infected with Clonostachys sp., an endophytic plant fungus, grew for a long time after infection, but died without pupating.

• Korean System Dynamics Review
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• v.7 no.2
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• pp.97-120
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• 2006

This paper deals with the extension of and discussion on the System Dynamics model (Jeong & Jeon, 2005) of river crabs in Korea. The previous model has been elaborated to empirically search for the optimal restoration and harvest rates of crabs in the Imjin River, on the basis of theoretical models of population dynamics in the field of bio-mathematics and environmental economics. In this paper, the authors tries to couple a series of new feedback loops related to density restrictions and cannibalistic behaviors with a stage-structured model of the crab ecosystem, and also to endogenize the parameter of baby crabs' survival that is caused by water quality improvement and income increase. Through these extensions and relaxations, the authors are able to argue about the strategic decision of the optimal rates additional considerations as well as the properties of the integrated system that was not covered in the previous paper.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.39 no.1
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• pp.42-48
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• 2006

Analysis of stomach content for common squid was carried out to investigate the difference in seasonal and ontogenetic feeding behavior. Totals of 1368 common squid were collected monthly off Busan from September 2004 to August, 2005. Size range of common squid was 8.5-31.8 cm mantle length (ML) during the study period. Of the 1368 stomachs examined, 599 specimens (43.8%) were empty. Stomach contents indicated that common squid was carnivore: Large portion of stomach contents consisted of fish and mollusca (mainly common squid). The stomach contents index (SCI) seemed to increase with size, though there was no statistical difference between size classes significantly. Cannibalism was minimum in size range of 15-20 cm ML, but was steadily increased with size. Cephalopods were the major prey during spring and summer when common squid were small, but fish replaced it during autumn and winter when they became large.

• The Bulletin of The Korean Astronomical Society
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• v.44 no.1
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• pp.50.1-50.1
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• 2019

In coronagraph images, it is often observed that two successive CMEs merge into one another and form complex structures. This phenomenon, so called CME cannibalism caused by the differences in ejecting times and propagating velocities, can significantly degrade forecast capability of space weather, especially if it occur near the Earth. Regarding this, we attempt to analyze the cases that two CMEs are expecting to meet around 1 AU based on their arrival times. For this, we select 13 CME-CME pairs detected by ACE, Wind and/or STEREO-A/B. We find that 8 CME-CME pairs show a shock structure, which means they already met and became one structure. Meanwhile 5 pairs clearly show magnetic holes between two respective shock structures. Based on detailed investigation for each pair and statistical analysis for all events, we can get clues for following questions: 1) How does the solar wind structure change when they are merging? 2) Are there any systematic characteristics of merging process according to the CME properties? 3) Is the merging process associated with the occurrence of energetic storm particles? 4) What causes errors in calculating CME arrival times? Our results and discussions can be helpful to understand energetic phenomena not only close to the Sun but also near the Earth.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.45 no.4
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• pp.187-198
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• 2022

This paper addresses the maintenance optimization problem in multi-component systems in which parts are connected in series, carrying out several missions interspersed with scheduled finite breaks. Due to limited time or resources, maintenance actions can be only carried out on a limited set of components. The decision maker then has to decide which components to maintain to ensure a pre-specified performance level during next mission. Most of the existing models in the literature usually assume only one system and enough spare parts. However, there are situations in which maintenance is required for multiple systems of the same type. To overcome this restrictive assumption, this study optimizes the maintenance problem considering the lack of repair parts and cannibalism for many identical systems. This study presents two optimization models with different objectives to solve the problem and analyzes the results so that the decision maker can decide. The results of this study are expected to be used for the maintenance of multiple systems of the same type, such as swarm drones.

• Animal cells and systems
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• v.16 no.2
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• pp.162-171
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• 2012

We investigated food webs of a $Salix$ $subfragilis$-dominated wetland in the Janghang wetland in the Hangang estuary, which is very close to the Demilitarized Zone, along the west coast of Korea. Our study focused on understanding sesarmine crab ($Sesarma$ $dehaani$)-related food webs in a $S.$ $subfragilis$ forest. For our study, we used carbon and nitrogen stable isotopes and fatty acid biomarkers. We collected samples of plants, animals, and detrital sediment from four quadrats ($5{\times}5m^2$) set in the $S.$ $subfragilis$ community. Samples were collected from September 2006 to June 2009, except during the winter hibernation period of $S.$ $dehaani$. In the wet season, the sediment showed relatively high ${\delta}^{13}C$ and low ${\delta}^{15}N$ signatures compared with relatively low ${\delta}13C$ and high ${\delta}15N$ signatures in the dry season. Mature $S.$ $dehaani$ appeared to feed on fresh leaves and other carbon sources, such as immature individuals or fish, in addition to detrital sediment, which appeared to be the main carbon source for immature crabs. Principal component analysis of fatty acid biomarkers of $S.$ $dehaani$ showed a clear difference between immature individuals (10-30 mm) and mature ones (larger than 30 mm), indicating that the main food source for immature crabs was detrital sediment, whereas mature crabs foraged plants in addition to consuming detrital sediment. On the basis of our results from stable isotope and fatty acid analyses, mature $S.$ $dehaani$ appeared to feed on detrital sediment and fresh leaves of $S.$ $subfragilis$ in summer in addition to engaging in cannibalism of immature individuals.

• Korean Journal of Environment and Ecology
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• v.25 no.5
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• pp.666-672
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• 2011

This study examined the different growth rate of larval salamander Hynobius leechii by the predation risk. We collected salamander's eggs from Mountain Inwang. Eggs were treated by two different conditions: (1) cue - which had a predation risk three times a day; (2) no cue - which had no predation risk. Predation risk was conducted by using chemical cue from Chinese minnows. The chemical cue treatment started from the next day after the collection and ended one week after the hatching. Between the first week and the second week after the hatching we fed salamander larvae with tubifex ad. libitium. After the treatment phase, we measured snout - vent length of the each larva on the first week and the second week after the hatching. The results showed that there was a significant difference in the growth rate by the predation risk. From these results we found that predation risk can cause the different growth rate to the larval salamander and these changes could be affect their mortality.