• The Journal of Engineering Geology
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• v.32 no.1
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• pp.13-26
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• 2022

Calcite twins were analyzed in six oriented samples of the Pungchon limestone, Joseon Supergroup, to reconstruct the paleostress field. The orientations of c-axis of calcite and e twin plane were measured along with the average thickness and numbers of twins, and the widths of calcite grains. Twin strain, mean width, and intensity of twinning, and the relative magnitude and orientations of principal stresses were calculated using Calcite Strain Gauge program. Twin strain, mean width, and intensity of twinning showed ranges of 1.09-15.36%, 0.53-3.72 ㎛ and 21.0-53.1 twim/mm, respectively. Metamorphic temperatures calculated from the twins were 170-200℃, indicating that the twins developed after the Pungchon limestone was uplifted to at least half of the maximum burial depth. Results for five of the samples indicate that the calcite twins formed during two events with principal stress axes of different orientations, while the remaining sample recorded only one event that produced calcite twins. The axis of maximum compressive stress was oriented mainly WNW-ESE to ENE-WSW, and to a lesser degree NW-SE and NE-SW. Comparison of paleostress orientations measured here and in other studies indicates that most twins were produced during the Songrim orogeny. However, the Daebo orogeny and the Bulguksa orogeny also produced calcite twins in the Punchon limestone.

• Journal of Preventive Medicine and Public Health
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• v.45 no.1
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• pp.29-36
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• 2012

Objectives: The purpose of this study was to identify any influence of socioeconomic status on smoking and smoking cessation in a situation where genetic factors are controlled. Methods: The sample for this study was 2502 members of the twins and families cohort who participated in the Korean Healthy Twins Study from 2005 to 2009. Groups of brothers or sisters, including twins and fraternal twins, were compared in terms of smoking and smoking cessation behaviors according to differences in socioeconomic status and gender. Results: In a situation with complete control of genetic factors, results showed that the daily smoking amount, cumulative smoking amount, and dependence on nicotine decreased with higher-status occupations, and the rate of smoking and amount of cumulative smoking decreased with higher levels of education. Regarding smoking cessation behavior, a higher level of education was associated with a lower smoking cessation rate, and no significant gender differences were found. Conclusions: Environmental factors had a stronger influence on smoking behavior than did genetic factors. Genetic factors had greater influence on smoking cessation than did environmental factors; however, this requires verification in further studies.

• Journal of applied mathematics & informatics
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• v.17 no.1_2_3
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• pp.109-120
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• 2005

Using the notion of intuitionistic fuzzy sets, the concepts of intuitionistic fuzzy finite state machines (iffsm), intuitionistic successor s, intuitionistic subsystems, intuitionistic submachines, intuitionistic q-twins, and intuitionistic retrievable iffsm are introduce d, and related properties are studied. Relations between intuitionistic q-twins and intuitionistic q-related iffsm are given. A characterization of an intuitionistic retrievable iffsm is provided.

• Proceedings of the Korean Society for Technology of Plasticity Conference
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• 1995.10a
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• pp.167-171
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• 1995

The formation of preferred orientations in cold rolled and recrystallized Inconel 690 sheets was studied by the x-ray texture measurements and TEM observations. The increasing{220} pole intensity in the plane normal at the higher reductions was related to the{110}<112> texture component. The rolling texture of the Inconel 690 was the pure metal type. THe dislocation cells were found in the near{110}<112> oriented grains. The onset of deformation twins in the {112}<111>oriented grains. The onset of deformation twins in the {112}<111> oriented grains. The onset of deformation twins in the {112}<111> oriented grains caused the weakening of {112}<111> and the development of {552}<115> in the rolling texture. The annealing texture of the Inconel 690 sheets was dependent on the annealing temperature. The annealing texture of 750$^{\circ}C$ annealed sheets was similar to the cold rolling texture. The major preferred orientations of the 950$^{\circ}C$ annealed specimens were {112}<110> and {001}<110>. The formation of fine and closely spaced annealing twins in the specimen annealed at 1150$^{\circ}C$ led to the randomization of the annealing texture.

• Women's Health Nursing
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• v.23 no.2
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• pp.89-98
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• 2017

Purpose: This study was conducted to identify effects of breastfeeding knowledge, attitude, and barriers on breastfeeding practice on twin mothers and to provide basic data for successful breastfeeding for twins. Methods: Participants were 151 mothers with two to twelve months-old twins. Data were collected from online support groups by an online survey. Results: Mean score for breastfeeding knowledge was $18.34{\pm}4.63$, for breastfeeding attitude was $3.61{\pm}0.51$, and for barriers to breastfeeding was $13.35{\pm}1.08$. The breastfeeding practice rate was 27.8% when twins were two months old. The breastfeeding knowledge was significantly different depending on mother's occupation, number of children, utilization of postpartum caretaker, and age of the children. There were significant differences in the breastfeeding attitude depending on gestational week of twins, planned length of the breastfeeding, and decision period for the breastfeeding. The practice of the breastfeeding was significantly different depending on the number of children. Factors influencing the breastfeeding practice were the breastfeeding attitude (p<.05), age of mother (p<.01), and the number of children (p<.01). Conclusion: An educational program and expert-led supportive system that is designed for twins are necessary, and they need to be included in prenatal care in order to have positive attitude for the breastfeeding as well as to breastfeed successfully.

• Journal of the korean academy of Pediatric Dentistry
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• v.1 no.1
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• pp.57-61
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• 1974

The Study reported here was designed to analyze the prevalence of Dental Caries in the primary teeth of monozygote twins, and to ascertain and compare the intrapair differences with the intrapair differences in control pairs. The prevalence of dental caries in the primary teeth of 40 pairs of presumably monozygote twins, based on phenotypic analysis, was studied. The age range was from 3 to12 years. The control group consisted of pairs that included a twin chosen at random and an unrelated child of the same sex and age, so that for each pair of twins there was a corresponding control pair. The clinical examination was carried out by an operator using an oral mirror and sharp explorers, and with good lighting. 40 pairs of twins were examined with a total of 4,950 primary tooth surfaces (990 primary teeth) and 40 control pairs with a total of 4,935 primary tooth surfaces (987 primary teeth). Five surfaces were considered for each tooth. After the def individual index was determined, the ratio between this index and the number of examined surfaces was established in each case, the cer (Caries experience rate) index. The def and cer averages were determined for the subjects and the controls. All intrapair differences in twin and control groups were compared following the paired sampling method. The following conclusions were made: 1. Intrapair differences in the control group were significantly greater than in twins, when defs, ds, es, fs, and cer were compared. 2. The genotype appeared to be a determining factor in dental caries susceptibility or resistance, although the environment played an important role as well. 3. Intrapair differences in American children were significantly greater than in Korean when defs, es, fs, and cer were compared, but ds was equal.

• Pediatric Infection and Vaccine
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• v.24 no.1
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• pp.65-70
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• 2017

Cytomegalovirus (CMV) infection is one of the most common congenital infections. The first case of discordant congenital CMV infection in twins occurred in Korea. A 31-year-old woman became pregnant with twins (dichorionic-diamniotic). An elective caesarean section was performed at 37 weeks. The first baby was male, weighing 2,410 g with an Apgar score of 8/9. The second baby was female, weighing 1,380 g with an Apgar score of 5/8. She had experienced intrauterine growth retardation, and presented with microcephaly, micrognathia, and joint stiffness. During the work-up for discordant twins, the second baby's serum test was positive for CMV immunoglobulin M. Her urine, blood, and cerebrospinal fluid (CSF) were CMV polymerase chain reaction positive. The first baby's CMV tests were negative. Ophthalmologic exam and audiometry performed on the second baby showed CMV retinitis and bilateral sensorineural hearing loss. She was treated with intravenous ganciclovir. Currently, she is bed-ridden and has significant developmental delay. Although the causes of discordant congenital CMV infection in twins are unclear, this case shows that discordant congenital CMV infection should be considered in twins with significant differences in intrauterine growth or clinical symptoms after birth.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2001.07a
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• pp.1057-1060
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• 2001

By comparison of the experimental results in two systems of ZnO varistors, its appear that Sb$_2$O$_3$is the indispensable element for twinning in ZnO varistors, and the Zn$_{7}$Sb$_2$O$_{12}$ spinel acts as the nucleus to form twins. A1$_2$O$_3$is not the origin of twinning in ZnO varistor, but it was found that A1$_2$O$_3$could strengthen the twinning and form a deformation twinning by ZnA$_{12}$O$_4$-dragging and pinning effect. The inhibition ratios of grain growth and nonuniformity of two systems ZnO varistors increase with the increase of A1$_2$O$_3$content. The twins affect the inhibition of grain growth, the mechanism could be explained follow as : twins increase the mobility viscosity of ZnO grain and grain boundary, and drag ZnO grain and liquid grain boundary during the sintering, then the grain growth is inhibited, and the microstructure becomes more uniform.orm.m.

• Pediatric Gastroenterology, Hepatology & Nutrition
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• v.16 no.3
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• pp.195-199
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• 2013

Congenital chloride diarrhea (CLD) is a rare inherited autosomal recessive disorder. Mutations of the solute carrier family 26 member 3 gene cause profuse, chloride ion rich diarrhea, which results in hypochloremia, hyponatremia and metabolic alkalosis with dehydration. If a fetal ultrasound shows bowel dilatation suggestive of bowel obstruction, or if a neonate shows persistent diarrhea and metabolic alkalosis, CLD should be considered in the differential diagnosis. The severity of CLD varies, but early detection and early therapy can prevent complications including growth failure. We report a case of dizygotic twins affected by CLD who had been born to non-consanguineous parents. Both of them showed growth failure, but one of the twins experienced worse clinical course. He showed developmental delay, along with dehydration and severe electrolyte imbalance. He was diagnosed with CLD first at 6-month age, and then the other one was also diagnosed with CLD.

• Reproductive and Developmental Biology
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• v.29 no.4
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• pp.269-271
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• 2005

The freemartinism is the most frequent form of intersexuality found in cattle, and females of heterosexual twins become sterile. With increase of twinning rates due to transfer of multiple embryos derived from in vitro fertilization, it is of great economic value to establish early diagnosis of freemartins to remove infertile individuals from breeding stock. In the present study polymerase chain reaction (PCR) of two different Y-chromosome specific segments (BRY.l and AMX/Y) was performed to identify freemartins from twins and less common single born freemartins in Korean Native Cattle (KNC). Two male-specific sequences were amplified in all heterosexual twins tested (n=5). In addition, Y-specific PCR products were detectable in one of the single born females (n=4) with visible genital abnormalities. These results suggest that the sensitivity of PCR-based assay may be sufficient to detect freemartinism in single born females as well as female partners of heterosexual twins in KNC.