• 대한치과교정학회지
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• 제53권3호
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• pp.194-204
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• 2023

Objective: To investigate sex-specific correlations between the dimensions of permanent canines and the anterior Bolton ratio and to construct a statistical model capable of identifying the sex of an unknown subject. Methods: Odontometric data were collected from 121 plaster study models derived from Caucasian orthodontic patients aged 12-17 years at the pretreatment stage by measuring the dimensions of the permanent canines and Bolton's anterior ratio. Sixteen variables were collected for each subject: 12 dimensions of the permanent canines, sex, age, anterior Bolton ratio, and Angle's classification. Data were analyzed using inferential statistics, principal component analysis, and artificial neural network modeling. Results: Sex-specific differences were identified in all odontometric variables, and an artificial neural network model was prepared that used odontometric variables for predicting the sex of the participants with an accuracy of > 80%. This model can be applied for forensic purposes, and its accuracy can be further improved by adding data collected from new subjects or adding new variables for existing subjects. The improvement in the accuracy of the model was demonstrated by an increase in the percentage of accurate predictions from 72.0-78.1% to 77.8-85.7% after the anterior Bolton ratio and age were added. Conclusions: The described artificial neural network model combines forensic dentistry and orthodontics to improve subject recognition by expanding the initial space of odontometric variables and adding orthodontic parameters.

• Journal of Preventive Medicine and Public Health
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• 제53권5호
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• pp.371-380
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• 2020

Objectives: This study investigated the effects of socio-demographic factors on the decreasing trend in the sex ratio at birth from 1997 to 2017 in Korea. Methods: Data from 10 349 602 live births registered with Statistics Korea from 1997 to 2017 were analyzed. The secondary sex ratio (SSR), defined as the ratio of male to female live births, during the study period (1997-1999 [phase I], 2000-2002 [phase II], 2003-2005 [phase III], 2006-2008 [phase IV], 2009-2011 [phase V], 2012-2014 [phase VI], and 2015-2017 [phase VII]) was calculated according to selected socio-demographic factors, such as parental age, education, occupation, and birth order. Logistic regression models were used to estimate odds ratios (ORs) and 95% confidence intervals for a male birth after adjusting for potential confounders. Results: The SSR gradually decreased from 1.10 (in 1998-2000 and 2002) to 1.05 (in 2013-2016). While a decreasing trend in the SSR was not noted among first births, male-biased sex ratios were prominent among third and higher-order births, for which the highest SSR was 1.46 in 1998. Higher birth order was significantly associated with an excess of male births in phases I-VI (≥third vs. first, OR range, 1.03 to 1.35). Advanced maternal age was significantly associated with an excess of female births in phases II, III, and V (≥40 vs. 20-24 years, OR range, 0.92 to 0.95). Conclusions: This study demonstrated that advanced maternal age and reduction of the artificially-biased SSR among third and higher-order births may partially explain the decreasing trend in the SSR from 1997 to 2017 in Korea.

• 한국수정란이식학회지
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• 제24권1호
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• pp.15-19
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• 2009

This study was carried out to collect the basic data about gestation lengths and offspring's birth weights and sex ratio of the dairy recipients transferred with Hanwoo IVF embryos. Blastocysts cultured for $7{\sim}8$ days were transferred to 96 and 167 heads for the basic data about gestation length and offspring's birth weight and sex ratio of the dairy recipients, respectively. The gestation lengths of the dairy recipients transferred with Hanwoo IVF embryos were $287.3{\pm}11.2$ ($257{\sim}311$) and $284.1{\sim}7.7$ ($266{\sim}295$) days in male and female of the offspring, respectively. The gestation lengths of the recipients were $290.7{\pm}10.4$, $285.8{\pm}3.4$, $280.0{\pm}9.3$ and $286.1{\pm}7.9$ days in spring, summer, autumn and winter of the calving season, respectively, and were significantly different among the calving season (p<0.05). The birth weights of male and female calves were $25.5{\pm}2.4$ ($21{\sim}30$) and $26.3{\pm}3.9$ ($21{\sim}40$ kg in offsprings of the dairy recipients transferred with Hanwoo IVF embryos, respectively. The sex ratio was 90.7 in the offsprings of the dairy recipients transferred with Hanwoo IVF embryos.

• 한국가금학회지
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• 제7권1호
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• pp.43-51
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• 1980

본 연구는 산란계에 있어 일령에 따른 수정율 및 부화율의 변화상을 조사하여 실용적인 중란생산기간을 구명함과 동시에 성비가 조절된 품종을 육성하기 위한 기초연구로서 일령에 따른 성비의 변화 및 성비와 경제형질간의 상관관계를 추정하고자 실시하였으며 백색레그혼 순종 248수의 165-262일 령까지의 7회 부화성적과 500일령까지의 주요경제형질에 대한 성적을 이용하여 분석한 결과는 다음과 같다. 1) 수정율 90%이상을 얻을 수 있는 실용적인 중란생산 기간은 7개월령이후가 적합한 것으로 사료된다. 2) 성비 40%이하군이 성비 60%이상군보다 수정율 및 부화율이 높은 경향을 나타냈다. 3) 성비 60%이상군이 성비 40%이하군보다 일영에 따른 성비의 변이폭이 컸다. 4) 체중과 란중에 있어서는 성비 60%이상군이 산란지수에 있어서는 성비 40%이하군이 좋은 성적을 나타냈다. 5) 성비 60%이상군에서 성비와 산란지수간에 빈의 상관이었으나 성비 40%이하군에서는 정상관이었다.

• 한국발생생물학회:학술대회논문집
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• 한국발생생물학회 1998년도 제4차 학술발표대회 및 정기총회
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• pp.61-62
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• 1998

The effects of rearing temperature on the sex determination of zebrafish were examined to address the questions, "Is it possible to control phenotypic sex artificially; and what genes may be involved in that process\ulcorner". At higher temperature(${32-34}^{\circ}C vs 28.5^{\circ}$C), a dramatic shift of the sex ratio(female 1 : male 9) was found. with DD-PCR cloning, several candidate genes were cloned and analyzed. Further analysis should help to understand sex-determining mechanisms involved in the artificial induction.induction.

• 한국보건간호학회지
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• 제12권2호
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• pp.149-171
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• 1998

This study attempted to find out a way which is to establish a desirable value and social culture related to sexuality. This study examined student's value and preference about sex and at the same time resolving method to correct ill-rooted value of male preference in our social culture. This study subjects consisted of 409 male and female students of a college located in Incheon area. The study data collected from June 5th to June 11th. 1998. Survey technique was chosen to collect data and analized by SPSS/PC+, SAS program using statistical methods of frequency. percent. $X^ 2-test$ and t-test. The study results are as follows ; 1) Sex satisfaction score of male students was higher than female students and the difference was significant statistically (p<0.0001). 2) There was a difference between male and female student's thought that our socity's structure has a sex discrimination. But female students felt strongly unequality of sex in our socity. 3) $65.4\%$ of total students have a general knowledge about sex and female student's score was higher than male students. The high percent of students get into know sex through mass media $(32.6\%)$ and peer groups $(31.9\%)$. 4) Student's attitude to sex was different from male and female students. Male students have more liberal attitude about sex than female students. 5) $97.1\%$ of the total students believe that our socity has son preference. 6) $86.5\%$ of the total students thought that sex ratio disproportion resulted from male preference is worriable problems in our socity. But there was no significant difference between both sexes.

• 한국인구학
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• 제24권2호
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• pp.117-147
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• 2001

이 연구는 북한의 1994년 인구센서스 자료에 나타난 성 및 연령구조를 분석하기 위한 것이다. 이 연구에서는 우선 1994년 1월 남북분단 이후 최초로 실시된 북한 인구센서스의 배경과 특징을 설명하고, 아울러 가용한 자료들을 활용하여 북한인구의 추세와 현황을 개관하였다. 이 연구의 초점은 북한 인구센서스 자료의 성 및 연령구조와 관련된 몇 가지 문제를 제기하고, 이를 재검토하는 데 맞추어져 있다. 북한이 제공하고 있는 인구자료에는 16-25세 연령집단의 남녀 성비가 비정상적으로 낮게 나타나고 있다. 또한 총인구규모에 있어서도 연령별 인구합계와 지역별 인구합계가 다르게 기재되어 있다. 이 연구에서는 북한 인구센서스 자료에 나타난 성 및 연령구조의 특징과 정확도를 파악하기 위하여 몇 가지 지수들이 작성되었으며, 이러한 작업을 토대로 북한인구의 성 및 연령별 분포를 재구성하여 수정인구를 추정하는 시도가 이루어졌다.

• 한국작물학회지
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• 제42권4호
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• pp.424-428
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• 1997

This study was carried out to investigate the effects of sowing dates, Apr. 25, May 15, June 5 and June 25, on sex ratio, growth and seed yield of "Chonnam species", local variety of hemp plant. The results were following as. : In sex ratio according to the different seeding dates, the revealating rate of female and male plants were highest on June 25, and Apr. 25, respectively. The length of stem, the number of branches, nodes, and seed yield were increased on May 15, but these charateristics were rapidly reduced on June 25 because of short growing period. Yield of seeds was increased by 24％ on May 15 comparing with 1.30ton /ha on Apr. 25.

• 한국응용곤충학회지
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• 제28권1호
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• pp.28-31
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• 1989

쌀바구미좀벌은 쌀바구미의 3영유충과 4영유충에 생난, 기생하였으며, 4영유충에 대해 현저한 선호성을 보였다. 기주가 4영유충일 때의 성비가 3영유충일 때에 비해 유의하게 높아서 생난시 암컷에 의해 인식되는 기주의 크기에 따라 좀벌의 성비가 조걸됨을 암시하였다.

• Animal cells and systems
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• 제13권2호
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• pp.223-227
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• 2009

This study was carried out on the ark shell Scapharca broughtonii in order to examine if organotin compounds, which are known to induce reproductive abnormalities in gastropods, have the same affect on bivalves. The research was conducted during seven weeks in spring season through a field transplantation experiment in one reference area (Ra) and two organotin-polluted areas (Opa) near a shipyard complex. Sex ratio in the Ra was 1:1.6 (female:male). Sex ratio in Opa I and Opa II were 1:0.49 and 1:1.03, respectively, illustrating slightly higher proportion of females. Gonad activity exhibited a sequence of Opa II>Ra>Opa I. Intersex individuals of 3.33% (n=4/120) were confirmed in Opa. Intersex gonads were observed only in females. The results show that organotin compounds caused reproductive disruption in Scapharca broughtonii.