• Korean Journal of Environment and Ecology
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• v.26 no.3
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• pp.342-347
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• 2012

This study was conducted to demonstrate the relationship between experience of cannibalism and difference of phenotype in the Korean salamander Hynobius leechii from March to April 2011. We examined whether the different polyphenism of larval salamander is induced as a result of indirect cannibalism in early life cycle. We divided into two groups(one group continuously exposed to the indirect cannibalism and the other group never exposed to the cannibalism). We measured the head width at the level of eyes(HWE), the largest head width(LHW) and snout-vent length(SVL) of the each larva then calculated the ratio of the head size by dividing HWE by LHW. We found that exposure of indirect cannibalism in early life cycle cause the different polyphenism. Our result means the larval salamander responded to the chemical cue from conspecific.

• Journal of Ecology and Environment
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• v.38 no.4
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• pp.477-483
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• 2015

Characteristics of snake reproductive organs that are relatively less affected by external environmental conditions can be used as an important means of classification; additionally, such characteristics can provide useful information on a species' reproductive system. In this study, we compared the testis weights, hemipenis lengths and retractor muscle lengths of male Oocatochus rufodorsatus and Rhabdophis tigrinus in Colubridae and Gloydius saxatilis, G. brevicaudus and G. ussuriensis in Viperidae. The snake snout-vent lengths (SVLs) were positively related to the three reproductive organ sizes, but the body weight only exhibited a positive relationship with the testis weight. The three organs did not significantly differ on the left and right sides. The relative testis weights and retractor muscle lengths (divided by the body weight and SVL, respectively) of the Colubridae snakes were greater than for the Viperidae snakes, but the relative hemipenis lengths (divided by SVL) did not differ between the two groups. The relative testis weight of G. saxatilis and the relative retractor muscle lengths of the Viperidae snakes were smaller compared with the Colubridae snakes. The relative hemipenis length of O. rufodorsatus was greater than for R. tigrinus, G. saxatilis and G. brevicaudus. Additional comparisons were not significant. Our results may facilitate further studies on hemipenial morphology and mating competition in Korean snakes. This is the first study on Korean snake reproductive organs.

• Korean Journal of Environmental Biology
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• v.32 no.1
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• pp.68-74
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• 2014

Scientific study has investigated the body condition differences by habitat characteristics in larvae Korea salamander (Hynobius leechii) from March to April in 2012. To examine the sensitivity of external environment (predation risk), we divided two groups according to habitat characteristic; 1) Permanent pond and 2) Temporary pond. Howere, each larva was measured by head width at the level of the eye (HWE), largest head width (LHW) and snout-vent length, and we calculated the ratio of the head size by dividing HWE/LHW. As a result, larvae were larger in permanent pond group, had a faster growth rate than in temporary pond group. When exposed to the predator, larvae in permanent pond were smaller HWE/LHW than larvae in permanent pond. Therefore, these results indicate larvae in temporary pond more sensitive to the external environment.

• The Journal of Korean Institute of Information Technology
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• v.16 no.12
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• pp.101-107
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• 2018

In wireless sensor network technology, which has been applied to various fields, the power supply and the power management of sensors are the most important issues. For this reason, a new concept of power supply and power management device is required. In this paper, we developed an autonomous independent power supply system that supplies the stable power to a sensor node without an additional external input by applying the energy harvesting technology using the electromagnetic induction principle by utilizing the current flowing in the transmission line. The proposed autonomous independent power supply system consists of a power supply using Power CT and a power management system including a charging circuit. The power management device uses a voltage limiter circuit and a monitoring circuit of charging voltage and current to ensure the safety of charging of the battery. In order to verify the performance of the proposed system, we applied it to the SVL diagnostic system and confirmed that it operates stably.

• Proceedings of the KIEE Conference
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• 2005.07a
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• pp.15-17
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• 2005

The protection of underground cables against transient overvoltages resulting from lightning and other causes is important in cable-line which is connected with overhead line and underground cable. This paper investigates the failure of SVL(Sheath Voltage Limiter) and presents the application of protection methods for single point bonding on underground transmission cable system. EMTP(Electromagnetic Transient Program) is used in order to study the overvoltages and modeling of components of the system such as, underground cables, SVLs and towers.

• Proceedings of the KIEE Conference
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• 2005.07a
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• pp.676-678
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• 2005

In underground power cable system, the apparent impedance at the relaying point can be changed because of the complicated configuration such as the various earth resistance and the operation of sheath voltage limiter (SVL). They have a bad effect on the distance relay operation Therefore, in this paper, in order to solve this problem, the authors are going to anly the advanced computational technique(ACI) of FR-FIS(Fuzzy Relation-based Fuzzy Inference System).

• Proceedings of the KIEE Conference
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• 2003.07a
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• pp.503-505
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• 2003

본 논문에서는 방전갭을 이용한 시스 순환 전류 저감장치 보호유닛을 제안하여 SVL형식의 저감장치 보호유닛과 뇌써지시 과도특성을 비교하였으며, 또한 시스 순환전류 저감장치 보호유닛 적용시의 고장전류분류율을 검토한 결과 모든 경우에 대하여 각 접지선의 고장전류분류율이 현행의 기준을 만족함으로써 시스 순환전류 저감장치 보호유닛을 적용한 저감장치의 현장적용 가능성을 제시하였다.

• Journal of Integrative Natural Science
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• v.16 no.1
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• pp.39-45
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• 2023

P2X receptors are ATP-activated ion channels in the plasma membrane. P2X receptors have a role in a diverse range of disorders, making them a valuable therapeutic target. Hence, the present investigation employed homology modelling of the P2X receptor based on the crystal structure of 5SVJ, 6AH4, 5YVE and 5SVL. Twenty models, using both single- and multiple template-based methods, were developed, and the best model was chosen based on the validation result. We observed that a strategy based on multiple templates provided greater accuracy. Future studies involving binding site and docking analysis can make use of the produced structures.

• Korean Journal of Environment and Ecology
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• v.28 no.5
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• pp.531-541
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• 2014

This research investigated the reproduction cycle, litter size, and the effects of factors of red-tongue viper snake inhabiting in Jeju Island, to delve into their life strategy. Field survey was conducted in Jeju Island from May 2006 to November 2008. Reproduction cycle was analyzed through measurements of testis and follicle sizes in laboratory from March 2009 to December 2010. According to the research results, the sizes of red-tongue viper snake's testis and follicle clearly changed seasonally. The number of eggs within the oviduct were greater on the right side ($2.6{\pm}1.0$ eggs, n=16) than on the left side ($1.8{\pm}0.5$ eggs, n=16) (t=-2,721, p<0.05). Average (${\pm}SD$) of survival litter size (SLS) was $4.4{\pm}1.7$ (1~9, range), while total litter size (TLS) was $4.7{\pm}1.5$ (3~9, range), which were not statistically significant. However, their litter sizes were similar to the number of eggs within the oviduct (t=0.039, P>0.05). Relative litter mass (RCM) was $0.42{\pm}0.13$ (0.18~0.79, n=33), and tended to increase, as maternal condition of pre-parturition (MCPPI) was getting better. The sexual ratio of delivered litters showed no significant difference between male and female red-tongue viper snakes (♂:♀ = 1.15:1, n=73 ; ${\chi}^2$=0.342, P>0.5). Average neonate mass showed a weak correlation with maternal mass of pre-parturition (MMPP1) (r=0.387, P<0.05, n=33). Average neonate Snout-vent length (SVL) also demonstrated a weak correlations with maternal SVL (r=0.399, P<0.05, n=33) and MMPP1 (r=0.344, P<0.05, n=33). Average neonate mass and maternal SVL approached significant probability (r=0.323, P=0.067, n=33). This indicates that mother snakes can bear bigger litter due to its larger size. In some cases, litter's weight decreases as mother snakes are bearing more litter; however, the red-tongued viper snake did not show such exchange relationship. From this, it can be conjectured that a red-tongued viper snake has peculiarity of its own species. The research results are predicted to be used as the basis to find a life history of red-tongued viper snake.

• Journal of Wetlands Research
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• v.15 no.4
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• pp.485-491
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• 2013

This study examined the cannibalistic polyphenism of larval salamander Hynobius leechii by the level of predation risk. Salamander eggs were collected from three regions (Mountain Inwang, Mountain Surak and Gwangju). Eggs were treated by three different risk conditions: (1) high risk, predation risk three times a day; (2) medium risk, predation risk once a day; and (3) low risk, no predation risk. Predation risk was conducted using a chemical cue from Chinese minnows. The chemical cue treatment started from the day of collection and ended one week after hatching. Post-treatment measurements were head width at the level of the eyes (HWE), largest head width (LHW), and Snout-vent length of the each larva. To compare the morphological change according to the predation risk, we modified the two head size, HWE and LHW, to HWE/LHW. A significant difference in HWE/LHW and snout-vent length was evident according to the level of predation risk. And larval mortality was increase by the predation risk. The results indicate that predation risk can cause cannibalistic polyphenism of larval salamander and this morphological change could influence larval mortality.