• Korean Journal of Fisheries and Aquatic Sciences
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• v.53 no.1
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• pp.83-89
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• 2020

This study provides a detailed morphological description of larvae obtained from Urocampus nanus and Syngnathus schlegeli male brood fish over 20 days of culture in the laboratory. In both species, mating takes place when several males each spread their brood pouch like a wing to attract a female's attention. When the female begins to swim upward, the males follow her and receive her eggs in their brood pouches. Newborn larvae of U. nanus and S. schlegeli had already completed formation of dorsal and caudal fin rays, but not of pectoral fin rays. Pectoral fin rays were completely formed 15 days after release in S. schlegeli and 20 days after release in U. nanus. The ratio of caudal fin length to standard length increased until 8 days and decreased thereafter in S. schlegeli, while in U. nanus this ratio declined continuously after hatching. The larvae of the two species were very similar in external morphology, but well distinguished by the number of dorsal fin rays (15-16 in U. nanus vs. 39-43 in S. schlegeli), the presence of a membrane under the tail (absent in U. nanus vs. present in S. schlegeli), and the presence of melanophores in the dorsal fin (present in U. nanus vs. absent in S. schlegeli). Based on this study, U. nanus appears to be evolutionally more similar to pipefish than to seahorse.

• Physical Therapy Korea
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• v.6 no.3
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• pp.82-93
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• 1999

Stroke is a serious disease despite recent improvement in medical and surgical treatment. Hence, identification of modifiable risk factors for stroke is important. This case-control study was done to demonstrate that relationship between smoking, alcohol consumption, obesity, perception of saltness and the incidence of stroke and to identify that smoking, alcohol consumption, obesity and perception of saltness, after adjusting for age, hypertension. A structured interview was carried out from April 15, 1996 to May 3, 1996 in Yonsei Medical Center. The study group consisted of 59 neurologically confirmed stroke patients as the study group and 59 non-stroke patients as controls. Analysis of the data was done by means of ${\chi}^2$-test and logistic regression analysis. The results were as follows. In the study group: 1) Hypertension in males had a 10.2 odds ratio (p<0.05), cardiovascular disease in females had a 11.3 odds ratio (p<0.05) and a farnily history of stroke in males had a 3.1 odds ratio (p<0.05). 2) Females smoking one or more cigarettes had a 8.3 odds ratio (p<0.1), but males had no direct relationship with odds ratio of 1.5 (non-significant). 3) Alcohol consumption in males had a 0.4 odds ratio, and in females had a 0.8 odds ratio. The odds ratio was decreased in alcohol consumption group (non-significant). 4) Males with more than 20 cigarettes pack-years history had a 2.5 odds ratio (p<0.05), more than 25 Body Mass Index had a 3.1 odds ratio (p<0.05) and more than 220 ml ethanol weekly consumption had a 1.5 odds ratio (non-significant). 5) Female smokers had a 8.3 odds ratio (p<0.1), drinkers a 0.8 odds ratio and more than 25 Body Mass Iidex, a 43.1 odds ratio (p<0.05). 6) Females without saltness perception from a 0.5% salt solution had a 6.8 odds ratio (non-significant). 7) By logistic regression analysis independent risk factors for stroke in males were found to be hypertention, age, and obesity. The study was limited because number of subjects was too small for practical implications. However, like as other results, this study suggest that people should be advised to control hypertension, and obesity since these carry a risk of stroke.

• Korean Journal of Ichthyology
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• v.35 no.3
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• pp.160-170
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• 2023

Life history of the endangered endemic species, Rhynchocypris semotilus, was investigated to obtain baseline data for its ecological characteristics in Songhyeoncheon, Hyeonnae-myeon, Goseong-gun, Gangwon-do, Korea from April to October, 2022. A total of 10 families and 18 species of fishes were collected from 4 survey stations, and R. semotilus was a subdominant species in the survey period (seven times). The main habitat of R. semotilus was the middle-upper stream of rock and boulder bottoms with aquatic plants and slow rapids and pools. The age groups for R. semotilus estimated by the frequency distribution of total length in spawning season (May) indicated the 4~12 mm is 0-year old, 32~49 mm is 1-year old, the 50~65 mm group is 2-years old, the 66~91 mm is 3-years old, and the 92~116 mm is more than 4-years old, and showed rapid growth from May to September. Total length range of female and male were the relatively similar, and sex ratio (♂/♀) was 0.78. The spawning period is from May to July (water temperature is 17 to 21℃), and gonad was developed more than three years old (more than TL 66 mm). In May, the gonadosomatic index (GSI) was 10.6±2.99% for females and 8.2±2.34% for males, fecundity was 6,830±1,943, and mature eggs size was 1.34±0.16 mm. Finally, life history characteristics of R. semotilus was discussed between the genus Rhynchocypris and Phoxinus species.

• Animal cells and systems
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• v.3 no.4
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• pp.369-374
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• 1999

The life history and development of Tetrastichus sp. parasitizing fallwebworm pupa in Korea were studied. The mean lifetime fecundity was 94.7 with a maximum of 125, and the portion of female progeny averaged 90.3%. A male and a female lived for an average of 19.8${\pm}$4.5 and 21.7${\pm}$4.2 days, respectively. The duration of development for each stage was as follows: egg, 2 d; the 1st instar larva, 2${\pm}$1 d; the 2nd instar larva, 2${\pm}$1 d: the 3rd instar larva, 3${\pm}$1 d; the 4th instar larva, 6${\pm}$2 d; and pupa, 8${\pm}$2 d. Total developmental duration from hatching of the larva to adult emergence required 21.1${\pm}$3.7 d, and females took 1-2 days more than males in the incubator (28$^{\circ}C$, 70% RH, and 16:8 LD).

• Animal cells and systems
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• v.6 no.1
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• pp.19-22
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• 2002

Life table studies were conducted in the laboratory for the eulophid gregarious pupal parasitoid, Tetrastichus sp., on Hyphantria cunea Drury at a constant temperature of 28.2$\pm$2$^{\circ}C$, 50-60% RH to evaluate their impact on the host and their potential biological control. Development of immature stage took 20.1$\pm$2.7 d: adult females lived for 23.2$\pm$2.2 (range, 16-27)d and produced a mean of 53.6$\pm$26.6 adult progeny per female, with a sex ratio of 1: 9.5 (M:F). The intrinsic rate of natural increase (r$_{m}$) was 0.178/ female/day; the net reproductive rate (R$_{o}$), 46.74; the capacity for increase (r$_{c}$) 0.177; the finite rate of increase (λ) 1.19/female/day; thus each female contributed 46.74 individuals to the population in a mean generation time of 21.6 d. Biological factors in determining the life history trait variation of the parasitoid were discussed.d.d.d.

• Korean Journal of Ichthyology
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• v.26 no.2
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• pp.89-98
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• 2014

Eggs development and early life history of the endangered Korean dwarf loach, Kichulchoia brevifasciata (Teleostei: Cobitidae) was investigated to provide basic information regarding biological characteristics and restoration. Adult fish specimens were sampled using a spoon net at Geurnsan-myeon, Goheung-gun, Jeollanam-do, Korea from June to July 2011. Since, spawning characteristics were analyzed, and females were induced to spawn by injecting Ovaprim (0.5 mL/kg) and their eggs were artificially fertilized with sperms by the dry method in the laboratory. Total length of mature female were 46~76 mm with GSI $9.6{\pm}3.77%$, and total length of mature male was 42~52 mm with GSI $3.5{\pm}1.04%$. Sex ratio (♂/♀) was 0.10, and there were no secondary sexual characteristics. The number of mature eggs was averaged $60{\pm}28.7$ per female. The lemon yellow eggs were slightly adhesive $1.46{\pm}0.07mm$ in diameter. The embryo hatched approximately 66 h after fertilization at $25^{\circ}C$, and the hatched larvae were averaged $5.5{\pm}0.07mm$ in total length (TL). At 6 days after hatching, the larvae averaged $9.0{\pm}0.29mm$(TL) and their yolk sac was completely absorbed. At 17 days after hatching, they entered the juvenile stage and reached $12.6{\pm}0.24mm$ (TL). At 80 days after hatching, the band patterns and external form of the juveniles were similar to those of adults, and they averaged $33.0{\pm}2.19mm$(TL).

• International Journal of Highway Engineering
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• v.17 no.1
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• pp.35-41
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• 2015

PURPOSES : The purpose of this study is to analyze the service life of expressway pavement based on both traffic volumes and use of deicing chemicals. METHODS : A database was built using expressway rehabilitation history information from over the last decade. In order to estimate the service life of expressway pavement, various analysis methods were considered, and a decision was made to perform analysis using a method based on an accumulated rehabilitation ratio. The service life of expressway pavement was then analyzed by classifying the scale of traffic volume and extent of de-icing chemicals used. RESULTS : The service life of PMA and SMA ranged from 7.8 to 10.6 years and from 9.9 to 12.0 years, respectively. The service life of JCP ranged from 16.0 to 22.2 years, and the service life of CRCP was 33.5 years on average. Results of assessing service life according to traffic volumes and de-icing chemicals showed that the lower the traffic volumes were, the greater the service life of PMA and JCP, and the less that de-icing chemicals were applied, the greater the service life of JCP. CONCLUSIONS : The dependence of expressway pavement service life on traffic volumes and de-icing chemicals makes it possible to apply LCCA for regional maintenance plans and cost-effective selection of expressway pavement type.

• Journal of Preventive Medicine and Public Health
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• v.35 no.3
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• pp.255-262
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• 2002

Objectives : To investigate the fetal cholesterol levels and related factors in a rural adult population. Methods : 3,207 adults(1,272 men and 1,935 women) were examined in 1997 Their heights, weights, and fasting serum total cholesterol levels were measured, and their body mass indices were calculated. A questionnaire interviewing method was used to collect risk factor data. Results : The mean value of total cholesterol were 190.5 mg/dl, and 198.8 mg/dl, and the age-adjusted prevalence rates for hypercholesterolemia (above 240 mg/dl) were 13.7% and 10.2%, in men and women, respectively. From simple analyses, age, educational level, coffee intake, amount of meat and food intake, waist circumference, waist-hip circumference ratio(WHR), and body mass index(BMI) were significant risk factors in men (p<0.05) relating to serum total cholesterol levels. In women, age, educational level, hypertension history, diabetes history, herbal drug history, amount of feed intake, alcohol consumption, waist circumference, WHR, BMI, and menopausal status were significant risk factors (p<0.05). In multiple linear regression analyses, waist circumference (p<0.01), BMI (p<0.01), and coffee intake (p<0.05) proved to be significant risk factors in men. Whereas, menopausal status (p<0.01), BMI (p<0.01), herbal drug history (p<0.01), amount of food intake (p<0.05), waist circumference (p<0.05), and alcohol consumption (p<0.05) were significant risk factors in women. Conclusions : The significant risk factors, for both men and women, relating to the serum total cholesterol were waist circumference and BMI. Thus, for the reduction of serum total cholesterol level, it is recommended that health education for the control of obesity should be implemented.

• Journal of agriculture & life science
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• v.44 no.1
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• pp.43-49
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• 2010

Life history of Gampsocleis sedakovi abscura Walker, an amenity sound producing insect, was investigated in Jinju, Korea from 2005 to 2007. G. sedakovi abscura had a generation per year and could be seen in the field from early March to late September. The peak emergence period of adults was early July. Developmental period from egg to adult was 357 days in average of three years in the field. Egg and nymphal periods, and adult longevity were 269, 88, and 357 days in average, respectively. The average ovipositional period was 63 days, and an adult laid 94 eggs in average throughout her life. The average longevity of adult was 90 days for female and 82 days for male. The sex ratio was 52%. G. sedakovi abscura over-wintered as egg stage in the soil. Circadian rhythm of the adult emergence showed that more than 70% of the adults emerged in the morning.

• Journal of Korea Spatial Information System Society
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• v.10 no.3
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• pp.45-54
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• 2008

This paper designs and Implements a connectivity analyzer for the hybrid vehicular network based on the real-life movement history data achieved from the Taxi telematics system currently in operation, aiming at providing a useful guideline and information to build a telematics network. The simulator traces the location of each vehicle, sets the vehicle type, either gateway or normal, decides whether it can be connected to a mobile gateway, keeps track of status of the vehicle, and calculates the duration of disconnected state. With this analysis considering the transmission range and gateway ratio, we can decide the cost-effective number of mobile gateways having both cellular and ad-hoc network interfaces, and buffer space requirement based on the measured disconnection time and message generation ratio.