• Proceedings of the KIEE Conference
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• 2006.11a
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• pp.158-160
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• 2006

The role of SVL (Sheath voltage limiter) in cable system is to protect the PVC(or PE) jacket in case of transient overvoltage resulting from lightning and other causes. But, in Korea, there is so many SVL failure cases resulting from power frequency overvoltage. So, the paper investigates the phenomenon of failure SVL comparing with other countries' system. Finally, the installation of ECC(Earth Connectivity Conductor) in under ground cable system is presented to remove the possibilities of SVL thermal runaway due to the power frequency overvoltage.

• Proceedings of the KIEE Conference
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• 2008.07a
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• pp.470-471
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• 2008

SVL is installed at underground transmission system to protect cables and insulation joint-box from overvoltages caused by lightning, switching, and line-to-ground fault. Domestic underground power system adopts cross bonding type to reduce the induced voltage at sheath, but single-point bonding is required depending the system installation configuration. SVL can be easily broken by overvoltages induced at joint-box because single-point bonding has uneffective system structure to extract fault current. ANSI/IEEE recommends Parallel Ground Continuity Conductor(PGCC) to prevent SVL breakdown. In this paper, EMTP simulation is performed to analyze effects on SVL under PGCC installation when single-line-to-ground fault occurs. The result shows that PGCC and short single-point bonding distance can reduce overvoltages at SVL.

• Proceedings of the KIEE Conference
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• 2008.11a
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• pp.119-121
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• 2008

In underground power cable system, the device for limiting over-voltage is needed when transient over-voltage break out between sheath and ground. For this reason, the SVL(Sheath Voltage Limiter) has been applied on weak points. But the broken SVLs which are installed on the single point bonding system on underground cable are frequently found. In this paper, EMTP(Electromagnetic Transient Program) is utilized to analyze effects on the installation methodology of the parallel ground conductor and SVL for the single point bonding system on the underground cable. The result shows that the proposed installation methodology can be applied for single point bonding system and contribute for power system stabilization.

• Journal of Ecology and Environment
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• v.33 no.4
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• pp.325-331
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• 2010

In this study, we have evaluated the physical characteristics of neonate, female, and male Mongolian racerunners (Eremias argus) and determined the age structure of a population of the species in a field located in Taean-gun, Chungnam, South Korea. The physical parameters of females and males, including snout-vent length (SVL), head length, head width, and body mass were found to be significantly interrelated. Male Mongolian racerunners exhibited significantly longer heads than the females, but other physical parameters, such as SVL, head width, and body mass did not differ between the female and male specimens. In the study population, the females ranged in age from two to eleven years old and the males ranged between two to eight years of age. The number of females and males, when separated into different age classes, did not differ within each age class. Male Mongolian racerunners evidenced greater SVL growth coefficients than the females, but asymptotic SVL did not differ between the females and males.

• The Korean Journal of Ecology
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• v.25 no.1
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• pp.25-28
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• 2002

The advertisement call of anurans functions to attract potential mates. The dominant frequency of an advertisement call is generally getting lower with increased snout-vent length (SVL) of the caller Rana rugosa has an advertisement call tilth a particularly high frequency modulation. We conducted a playback experiment to verify the function of frequency modulation, and investigated the territorial behavior of the frog. The frog has five types of territory defense strategy. Strategy choice depended on the caller's SVL. Small males became satellites or lowered the dominant frequency of their advertisement call, whereas large males actively defended their territory with encounter calls. In response to high frequency (1107 Hz) playback, the frogs lowered their advertisement call frequency, and towered them further in response to the low frequency (1028 Hz) playback. In addition, the number of pulses in a call was increased in response to the playback. These results indicate that the frog avoids physical conflict with competitors by selecting a territory defense strategy suitable for the caller's size, and by lowering its call frequency to disguise its SVL.

• Korean Journal of Environment and Ecology
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• v.26 no.5
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• pp.668-674
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• 2012

This study was conducted to find the sexual size dimorphism(SSD) in morphometric characters of three species, Eremias argus, Takydromus amurensis and T. wolteri in lacertid lizard from Korea. Six external traits, snout-vent length, tail length, head length, head width, forelimb length and hind-limb length were focused to compare two sexes among the each three lizards. Student's t-test was used to compare the adult SVL between the sexes for each species. For the other parts of the body, a one-way analysis of covariance(ANCOVA) with SVL as the covariate was used. In all these species, males have longer tail and head than females like general lacertid lizard. In addition, male E. arugus have broader head and longer forelimbs and hind-limbs than conspecific females. Likewise, male T. wolteri have broader head than females. In the three lacertid lizards from Korea, snout-vent length did not significantly differ between the sexes. To understand the causes for SSD in SVL, ecological information, such as the presence/absence of male-male combat and the correlation between the SVL of female and litter size, is required. Therefore, further ecological study on the three species of lacertid lizard from Korea will make it possible to explain the reason SSD is not found in SVL.

• Korean Journal of Environment and Ecology
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• v.25 no.6
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• pp.861-866
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• 2011

Using skeletochronology in the Daejung-eup, Jeju, we determined the age structure of Kaloula borealis. The study was performed during the breed season in June 2009. We measured the snout-vent length(SVL) and body weigth(BW) and analyzed the age structure of 38 male and 58 female frogs. The mean value of SVL is $43.69{\pm}3.44mm$ in males and $46.32{\pm}4.23mm$ in females. The age at first reproduction was estimated to be 2 years of age in males and 3 years in females. The oldest males and females were 8 and 10 years of age, respectively. Therefore, the longevity in this species was estimated to be more than 8 years for males and 10 years for females. So, females live longer than males. Also, this difference between the male and the female in age structure was significant. We estimated the growth curve for Kaloula borealis using von Bertalanffy growth model. The growth coefficient (K) was 0.56 in male and 0.41 in female. The asymptotic size was 46.41 mm in male and 50.22 mm in female.

• Journal of Ecology and Environment
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• v.31 no.3
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• pp.183-191
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• 2008

To determine the age structure of a Hynobius leechii breeding population and analyze relationships between the order of entrance to breeding ponds and physical parameters and age, we studied a wild population of the species in the Research Forests of Kangwon National University in Chuncheon, Kangwon, South Korea from March 16 to April 13, 2005. The age of breeding males ranged one to nine years old and that of females ranged from three to nine years old. The asymptotic sizes of males and females were 6.36 and 6.51 cm, respectively, and the growth coefficients of males and females were 0.71 and 0.81, respectively. The snout-vent length (SVL), head length, and body mass of males were all positively correlated with their age, but female age did not show a significant relationship with any physical parameter. The tail depth, body mass, and condition factors (SVL/body mass $\times$ 100) of both males and females were negatively related with the order of entrance to the breeding pond. The head width and SVL of males were also negatively correlated with the order of entrance, but the SVL of females was positively related with the order of entrance. These results suggest that physical parameters are more important determinants of breeding migration patterns than age. We discuss which of two hypotheses, the mate opportunity hypothesis and the susceptibility hypothesis, is better able to explain the order of entrance to breeding ponds for male and female H. leechii.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.63 no.6
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• pp.764-769
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• 2014

This paper describes sheath voltage limiter(SVL) transient characteristics by switching overvoltage considering single point bonding in underground transmission cables. The crossbonding system is generally used for grounding methods of underground transmission system. However, the single point bonding system is used in selective area which is difficult to consist of crossbonding major section. The sheath voltage limiters are connected between joints in the single point bonding. Specially, the high overvoltage might be generated in that section as well as the aging of sheath voltage limiter might be progressed by various electrical stress including lightning overvoltage, switching overvoltage and power frequency overvoltage. Therefore, in this paper, the switching overvoltage characteristics in underground cables are firstly analysed using EMTP simulation. Then, the switching overvoltage of sheath voltage limiter is also studied in single point bonding. Finally, the reduction method of sheath voltage limiter switching overvoltage is proposed by various simulation studies including circuit breaker operating order.

• Journal of Chest Surgery
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• v.19 no.1
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• pp.43-49
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• 1986

At the Department of Thoracic and Cardiovascular Surgery, Hanyang university, from 1976 to 1984, 102 patients operated for isolated patent ductus arteriosus were studied. The correlation between the degree of left ventricular hypertrophy [LVH] and hemodynamic data, and postoperative changes of electrocardiographic findings were evaluated. The following results were obtained; [1] Of 102 patients with isolated patent ductus arteriosus, 78 patients [76.5%] were found to have LVH by EKG, preoperatively. [2] The patients with LVH had higher incidence of respiratory infection [79.4%] compared to patients without LVH. [3] Frequent physical findings in the patients with LVH were precordial bulging and P2 accentuation on auscultation. The typical continuous machinery murmur was not different in two group with or without LVH. [4] 66.1% of patients with LVH showed more than 56% of cardiothoracic ratio [CTR] on simple chest X-ray. 56.5% of patients without LVH showed less than 50% of CTR. [5] In the patients found to have LVH by EKG, the correlation between values of Svl+Rv6 and Qp/Qs in hemodynamic data was correlation coefficient 0.57 and between CTR and Qp/Qs was correlation coefficient 0.51. [6] In patent ductus arteriosus with LVH following surgery, the values of Svl+Rv6 was changed from preoperative 153.6$\pm$42.78% to 107.7$\pm$19.58% within 3 months and to 80.4$\pm$12.22%, which is within normal range of Svl+Rv6 on EKC, after 6 months.