• 지질공학
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• 제32권1호
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• pp.13-26
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• 2022

본 연구는 방해석 내 쌍정을 이용하여 조선누층군 풍촌석회암층의 고응력장을 규명하기 위함이다. 이를 위해 조선누층군 두위봉형의 풍촌석회암에서 6개의 시료를 채취하여 방해석 c-축의 방향 및 경사, e 쌍정면의 방향 및 경사, 쌍정의 평균 두께 및 갯수, 방해석 입자의 크기 등을 측정하였다. 측정된 자료들은 Calcite Strain Gauge 프로그램에 입력되어 쌍정의 변형률, 평균 두께, 치밀도 및 고응력장의 상대적 크기 및 방향 등을 계산하였다. 쌍정의 변형률은 1.09~15.36%, 평균 두께는 0.53~3.72 ㎛, 치밀도는 21.0~53.1 twin/mm의 범위를 보인다. 쌍정의 변형률, 치밀도 및 두께에 의한 변성온도 계산결과 대부분의 시료에서 170~200℃ 이하를 보여, 풍촌층의 상부층인 직운산층의 변성온도에 비교할 때 최대 심도의 절반 이상 상승한 후에 쌍정이 생성된 것으로 판단된다. 응력장의 방향은 5개의 시료에서 2방향을 보이는 반면, 단지 1개의 시료에서만 한 방향을 보여 대부분의 시료에서 압축응력이 2번 이상 작용하였음을 보여준다. 압축응력은 WNW-ESE~ENE-WSW의 방향성이 가장 우세하고 NW-SE와 NE-SW의 방향성도 보인다. 본 연구에서 측정된 고응력장과 연구지역 인근에서 지질구조나 다른 방법에 의하여 규명된 고응력장과 비교할 때 E-W 방향의 고응력장은 트라이아스기 말에서 쥬라기 초에 발생한 송림조산운동에 가장 큰 압축응력이 작용하였고 쥬라기에 발생한 대보조산운동과 불국사 변동에 의해서도 쌍정이 생성된 것으로 판단된다.

• Journal of Preventive Medicine and Public Health
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• 제45권1호
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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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• 제17권1_2_3호
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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.

• 한국소성가공학회:학술대회논문집
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• 한국소성가공학회 1995년도 추계학술대회논문집
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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.

• 여성건강간호학회지
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• 제23권2호
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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.

• 대한소아치과학회지
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• 제1권1호
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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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• 제24권1호
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• pp.65-70
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• 2017

거대세포바이러스 감염은 선천감염의 가장 흔한 원인 중의 하나이다. 본 증례는 쌍생아에서 다른 임상 양상을 보인 선천 거대세포바이러스 감염 증례에 대한 국내 첫 보고이다. 31세 초산부가 쌍생아(2 융모막, 2 양막)를 임신하였다. 임신 34주 산전 초음파에서 한쪽 태아의 크기가 작고 양측 뇌실 확장증이 발견되었으며 임신 37주경에 제왕절개로 분만하였다. 첫 번째 신생아는 남자로 출생 체중 2,410 g, 아프가 점수 8/9점으로 출생하였으며 두 번째 신생아는 여자로 출생 체중 1,380 g, 아프가점수 5/8점으로 출생하였다. 두 번째 신생아는 자궁 내 성장지연, 소두증, 소하악증, 사지 관절의 강직을 보였다. 불일치 쌍생아에 대한 원인을 찾기 위한 검사를 진행하였으며 두 번째 신생아의 혈액검사에서 거대세포바이러스 immunoglobulin M이 양성반응을 보였으며 소변과, 혈액, 뇌척수액에서 거대세포바이러스 중합효소연쇄반응이 양성소견을 보였다. 반면에 정상으로 출생한 남아의 거대세포바이러스에 대한 검사는 모두 음성이었다. 감염된 환자의 안과적 검진에서 거대세포바이러스 망막염이 관찰되었고, 후에 실시한 청력검사에서 양측의 감음 난청이 확인되었다. 환자는 ganciclovir 치료를 받았으며 현재 여아는 심한 발달지연이 있으며 침대에서 누워서 생활하는 중이다. 이와 같이 쌍생아에서의 선천 거대세포 바이러스 감염증이 한 명에게만 발생하는 경우의 원인은 현재까지 명확하지 않다. 하지만 이 증례를 통하여 심한 불일치 쌍생아의 경우에 선천 거대세포바이러스 감염의 가능성을 고려해 보아야 한다.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2001년도 하계학술대회 논문집
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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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• 제16권3호
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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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• 제29권4호
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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.