• Coupled systems mechanics
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• 제5권3호
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• pp.223-234
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• 2016

The main purpose of current study is to find the soil effects on natural period of elevated tank. The coupled analytical method is used to assess in this study. The current study presented models which are capable to consider the soil dynamic stiffness changes and fluid- structure interaction effects on natural period of elevated tanks. The basic of mentioned models is extracted from elastic beam and lumped mass theory. The finite element is used to verify the results. It is observed that, external excitation can change the natural period of elevated tanks. Considering the increase of excitation frequency, the natural period will be decreased. The concluded values of natural period in case of soft and very soft soil are more affected from excitation frequency values. The high range of excitation frequency may reduce the natural period values. In addition it is observed that the excitation frequency has no significant effect on convective period compare with impulsive period.

• Asian-Australasian Journal of Animal Sciences
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• 제13권3호
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• pp.287-291
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• 2000

The study was based on 1921 service period records of Nili Ravi buffaloes maintained at six dairy farms in Pakistan during the period 1978 to 1994. The mean service period was $237.57{\pm}4.5$ days in the over all data. The highest mean service period ($393.59{\pm}16.18$ days) was at MDF Rawalpindi and the lowest ($199.15{\pm}14.35$ days) was at MDF Peshawar. The difference was significant p<0.001. Late maturing buffaloes showed significantly longer service period as compared to early maturing buffaloes. Parity and seasonal effects on Service Period were studied. There was an overall trend of reduction in the length of service period with the increase in parity. The mean ($287.54{\pm}6.89$ days) service period was (highest) in parity number one and lowest in parity number eight ($107.95{\pm}19.72$ days). The difference was highly significant. In overall data significantly lower service periods were seen in buffaloes calving in spring+winter as compared to summer+fall.

• 공학교육연구
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• 제24권2호
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• pp.3-11
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• 2021

In the COVID-19 era, it was implemented to be used as a basic material for setting the direction of learning support and student guidance for university institutions and professors who are experiencing confusion. The purpose of this study is to compare the actual status of daily-routines of COVID-19 period, general semester period, and vacation period, and to examine whether there is a difference between the period of general semester and COVID-19 period, and whether there is a difference in daily use of COVID-19 period depending on grade. For this reason, a questionnaire survey was conducted from April 23 to 29, 2020, targeting students of University A, which is a small-scale technical centered university in the region, and 754 students answered. As a result of the study, first of all, when we looked at the trends in the use of daily-routines by period of general semester, vacation period, and COVID-19 period, the trends of the general semester period and COVID-19 period were similar in the areas of learning and self-development. Second, there were statistically significant differences in sleep, relaxation, learning and other areas between the period of the general semester and the duration of COVID-19. Third, there were statistically significant differences over grade in relaxation, learning, development, and other areas.

• 한국동물학회지
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• 제37권4호
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• pp.478-487
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• 1994

The developmental changes of three enteroendocrine cells, i.e. gastrln, somatostatin and serotonin, of gastric and small intestinal mucosa in pre- and postnatal rat were examined by peroxidase-antiperoxidase (PAP) method. In the course of development, gastrin cells were obsenred in the pyloric gland region and the whole part of small intestine, while somstostatin and serotonin cells in the whole gastric gland region and small intestine. More entroendocrine cells were detected in the pyloric gland region and duodenum than in the other portion. In the stomach, gastrin, somatostatin and serotonin ceils were first obsenred in the pyloric Bland region on 17, 19 and 19 days of gestation respectively. The small intestinal gastrin and serotonin cells were first appeared in the duodenum and iriunum on 17 and 15 days of gestation respectively, and somatostBtin cells in duodenum on 17 days of gestation. The number of cells examined from the stomach were increased from fetal to weanling period and showed a decrease during adult period: the notable increase was shown at the end of suckling period or at early weanling period. The cells of the small intestine increased from fetal to suckling period, especially, these cells markedly increased at the end of fetal period or at early suckling period, and decreased from weanling period. The shape of these cells was oval or fusiform during fetal period. In the stomach, most of gastrin cells turned out to be oval and open-type from suckling period, while the remaining two tripes of cells were oval and open- or closed-type. In the small intestine, 311%Ves of cells examined were changed to fusiform and open-type from the end of fetal period. Three types of cell were distributed over the stratified epithelium on 15 and 17 days of gestation. In the stomach, these cells were distributed lower gastric pit and gland from the following fetal period, and were detected mainly on the upper part of gland from suckling period, and then obsenred on the whole part of gland. In the small intestine, most of cells distributed over only between epithelium of villi on 19 days of gestation, increased in number on the crypt from following fetal period, and also observed abundantly in the crypt at adult period.

• 한국경영과학회지
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• 제32권2호
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• pp.141-147
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• 2007

We consider a GI/M/1 queue with vacations such that the server works with different rate rather than completely stops working during a vacation period. We derive the transform of the joint distribution of the length of a busy period, the number of customers served during the busy period, and the length of the subsequent idle period.

• 비교문화연구
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• 제31권
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• pp.371-394
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• 2013

This study aims to know word forms and usages according to personal relationships of 'Kureru Kudasaru' by analyzing dialogues of female speakers. Novels of the Meiji period when there were attempts of a language revolution were mainly used for this study as well as novels of the Edo Period and the Taisho Period. Firstly, the number of examples according to gender differences in the novels was as follows. In case of 'Kureru', female speakers showed a high usage rate in the novels of the Edo period. 'Kureru' was mostly connected with female languages such as 'Naharu', 'Namasu', 'Nansu'. These expressions were not used in the novels of the Meiji Period and the Taisho Period. Although 'Okureru' and 'Okurenasaru' were used in the novels of the Meiji Period, the number of examples of 'Kureru' by female speakers was decreased in the novels of the Meiji Period and the Taisho Period. 'Kudasaru' was predominantly used by female speakers. Especially, female speakers used clearly to show vertical relationships in the novels of the Edo Period and"Doseishoseikatagi"of Meiji 10s. After"Ukigumo", the usage rate of female speakers was decreased but the usage rate of male speakers was increased. Gender differences became gradually smaller. Female speakers in the novels were increased from geisha and relatives such as wife, sister, mother and children to young women, teacher and student. Aspects of benefactive verbs' usages could be summarized as follows. Female speakers at licensed quarters used clearer and more typical expressions according to vertical relationships and gender differences in the novels of The Edo Period than the novels of The Meiji Period and the Taisho Period. In the novels of the Meiji Period, female speakers in a sophisticated social group used benefactive verbs to show strong respect and concern for the other person. In the novels of the Taisho Period, female speakers used benefactive verbs to show respect and concern for the other person according to their areas of outside activities. In the novels of the Meiji Period, female speakers used 'Okureru' when the other person was younger than them and was socially and psychologically close to them. Also, 'O~Nasaru' which was one of respect expressions was used by female speakers. Female speakers used it to older people in the Edo period but they also used it to younger people in the Meiji Period. Examples were not shown in the novels of the Taisho Period. Usages of 'Kureru' 'Kudasaru' according to vertical relationships were as follows. If 'a giver' was an older person, 'Kureru' with respect expressions 'Nasaru' 'Nansu' 'Namasu' was used more than 'Kudasaru' in the novels of the Edo Period. However, many examples of 'Kudasaru' were shown on the novels of the Meiji Period and the Taisho period. In the novels of the Meiji Period, 'Okureru' and 'Okurenasaru' which were expressions included in 'Kureru' were shown. Female speakers used them to older people who were socially and psychologically close to them like family. There were not many examples of 'a giver' and 'a receiver' around the same age. However, 'Kureru' and 'Okureru' were used in a younger group and 'Kudasaru' was used in an older group in the novels of the Meiji Period. If 'a giver' was an younger person, 'Kureru' was mainly used in the novels of the Edo period and "Doseishoseikatagi"in Meiji 10s. However, 'Kudasaru' was used many times in the novels of the latter Meiji Period and the Taisho Period.

• 영재교육연구
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• 제16권1호
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• pp.21-42
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• 2006

이 연구의 목적은 1990년 1월부터 2003년 12월까지 국내 주요일간지에 게재된 영재교육 관련 기사의 양과 내용을 분석함으로써 시대에 따른 영재교육의 사회적 인식과 경향을 살펴보기 위한 것이다. 연구대상의 기간은 3기로 나누었고, 관련기사의 내용은 영재교육의 동향, 영재교육 정책, 영재교육 정보, 사회 환경으로 분류하여 분석하였다. 분석 결과 영재교육 관련 기사의 양은 시기별로 꾸준히 증가하였고, 특히 2000년 영재교육진흥법 제정 이후에 큰 폭의 증가를 나타내었다. 이를 통해 영재교육이 정착화 됨에 따라 영재교육 관련기사도 점차 영재교육 전반에 걸쳐 큰 폭으로 다루어지고 있음을 알 수 있다. 또한 영재교육 관련 기사의 내용에 있어서는 1기에는 체제와 제도에 관련된 기사가, 2기와 3기에는 영재교육기관에 관한 기사가 많았다. 이는 1기에는 영재교육에 대한 여러 논의를 통해 영재교육의 필요성에 대한 인식 정착되었고, 2기와 3기에 영재교육에 대한 제도화가 이루어지면서 영재교육 기관에 대한 관심이 커졌음을 알 수 있다.

• 한국수학사학회지
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• 제24권2호
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• pp.91-108
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• 2011

중국의 수학교육을 실험시기(제1기, 1949년~1965년), 침체시기(제2기, 1966년~1976년), 수정시기(제3기, 1977년~1999년), 발전시기(제4기, 2000년 이후)로 구분하여 시기별 변천 과정을 고찰하고, 수학교육의 변천 원인 등 몇 가지 특정과 시사점을 도출하였다.

• 대한치과보철학회지
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• 제25권1호
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• pp.195-204
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• 1987

The purpose of this study was to investigate the effect of occlusal splints on the masseteric silent period and the changes of the masseteric silent period after experimental bruxism with occlusal splints. In nine subjects, anterior occlusal splints were fabricated. The jaw-jerk reflex was induced by tapping over mandibular symphysis area with solenoid driven hammer and electromyogram of left masseter muscle was recorded. In the recorded electromyogram of left masseter muscle the silent period duration was measured. This procedure was done before insertion of anterior occlusal splints, after insertion of anterior occlusal splints, after 30 min experimental bruxism with anterior occlusal splints, and 3hr after removal of anterior occlusal splints. The result were as follows; 1. The mean silent period duration was increased after insertion of occlusal splints compared with the mean silent period duration before insertion of occlusal splints. 2. There was no change of the mean silent period duration after 30 min experimental bruxism with occlusal splints compared with the mean silent period duration after insertion of occlusal splints. 3. 3hr after the removal of occlusal splints, the mean silent period duration showed no difference from the mean silent period duration before insertion of occlusal splints.

• Structural Engineering and Mechanics
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• 제31권2호
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• pp.211-223
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• 2009

Transient response analysis can be conducted either in the time domain, or via the frequency domain. Sometimes a frequency domain method (FDM) has advantages over a time domain method. A practical issue in the FDM is to find out an appropriate extended period, which may be affected by several factors, such as the excitation duration, the system damping, the artificial damping, the period of interest, etc. In this report, the extended period of the FDM based on the Duhamel's integral is investigated. This Duhamel's integral based FDM does not involve the unit impulse response function (UIRF) beyond the period of interest. Due to this fact, the ever-lasting UIRF can be simply set as zero beyond the period of interest to shorten the extended period. As a result, the preferred extended period is the summation of the period of interest and the excitation duration. This conclusion is validated by numerical examples. If the extended period is too short, then the front portion of the period of interest is more prone to errors than the rear portion, but the free vibration segment is free of the wraparound error.