• 대한통합의학회지
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• 제8권4호
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• pp.291-305
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• 2020

Purpose : The duration of speech segments reflects children's speech motor development. The purpose of this study was to determine whether segmental sound and word duration varies by age among preschool children. Methods : A total of 60 children aged 4~5 years participated in this study. Participants took the picture-naming test to produce single-word speech data. The duration of the consonant at the initial position of the word and the final position of the word, the voice onset time of plosive, the duration of the vowel following the initial consonant, and the duration of the word were measured. Results : As age increased, the duration of the initial consonant, the duration of the word, and the voice onset time decreased significantly. The main effects of age, manner of articulation, and place of articulation on the duration of the initial consonant were significant. The duration of consonants in the nasal sound and plosives and the duration of bilabial and alveolar sound differed significantly between groups. The main effects of age and vocal type on voice onset time were significant. The main effect of age on the duration of the consonant in the final position of word and on the duration of the vowel were not statistically significant. Conclusion : The results of this study showed that the duration of segmental sound and the word were associated with speech development between 4 and 5 years old. Accordingly, duration of the segmental sound and the word may serve as an acoustic cue as they reflect speech development and speech motor control maturity.

• 한국작물학회지
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• 제52권1호
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• pp.112-121
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• 2007

Grain filling is a crucial factor that determines grain yield in crops since it is the final process directly associated with crops' yield performance. Grain filling process can be characterized by the interaction of rate and duration of grain filling. This study was conducted, using 16 temperate japonica rice genotypes, with aims to (1) seek variations in grain filling duration and rate on area basis, (2) compare the contribution of grain filling duration and rate to grain yield, and (3) examine the influence of temperature and solar radiation for effective grain filling on grain yield in relation to grain filling duration and rate. Grain filling rate and duration exhibited highly significant variations in the ranges of $20.7{\sim}46.3\;g\;m^{-2}d^{-1}\;and\;11.2{\sim}35.5$ days, respectively, depending on rice genotypes. Grain yield on unit area basis was associated positively with grain filling duration but negatively with grain filling rate. Grain filling rate and duration were negatively correlated with each other. Final grain weight increased linearly with the rise in both cumulative mean temperature and cumulative solar radiation for effective grain filling. Higher cumulative mean temperature and cumulative solar radiation for effective grain filling were the results of longer grain filling duration, but not necessarily higher daily mean temperature and daily solar radiation for effective grain filling. Grain filling rate demonstrated an increasing tendency with the rise in daily mean temperature for effective grain filling but their relationship was not obviously clear. It was concluded that grain filling duration, which influenced cumulative mean temperature and cumulative solar radiation for effective grain filling, was the main factor that determined grain yield on unit area basis in temperate Japonica rice.

• 한국컴퓨터산업학회논문지
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• 제7권3호
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• pp.191-198
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• 2006

소프트웨어 측정분야는 30년 이상 수많은 연구가 있어 왔으나 아직까지 구체적인 소프트웨어 개발노력, 개발기간과 비용 추정 모델이 없는 실정이다. 소프트웨어 개발기간을 추정하기 위한 기존의 모델들은 사용된 데이터 크기가 적고 과거 프로젝트들을 대상으로 하고 있어 현재의 복잡하고 다양한 개발환경에 적용하는데 제약이 따른다. 따라서, Oligny et al.은 ISBSG Benchmark Release 4의 396개 프로젝트에 대해 개발기간이 개발플랫폼에 영향을 받음을 제기하여 각 개발플랫폼에 따른 개발기간 추정 모델을 제시하였다. 본 논문은 Oligny et al. 모델들을 ISBSG Benchmark Release 6의 534개 프로젝트에 대해 적용한 결과 개발기간이 개발플랫폼에 영향을 적게 받음을 밝혔다. 따라서, 개발기간에 보다 영향을 미치는 개발형태를 채택해, 개발형태에 따른 개발기간 추정 모델을 제시하였다. 제안된 모델들은 개발 플랫폼의 영향보다 개발기간 추정에 보다 많은 영향을 미침을 밝혔으며, 개발기간 추정시 개발형태별로 추정하는 모델 적용이 보다 타당함을 알 수 있다.

• 정보처리학회논문지D
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• 제10D권7호
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• pp.1127-1136
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• 2003

소프트웨어 개발 초기에 개발비용, 소요 인력과 기간을 추정하는 것은 소프트웨어공학 분야의 주요한 요소이며, 어려운 문제이다. 소프트웨어 개발 소요 인력을 추정하기 위한 대부분의 모델들은 소프트웨어 요구사항 명세서로부터 측정된 기능점수를 이용하였다. 본 논문은 기능점수에 기반하여 프로젝트에 대한 가장 실제적이고 생산적인 팀 규모와 개발기간을 선택하는 지침으로 사용될 수 있는 정보를 제공하기 위해 생산성 척도와 비용 척도를 도입하였다. 소프트웨어 개발과 유지보수를 수행한 300개 프로젝트 데이터 집합을 2개의 서브 그룹인 개발 프로젝트와 유지보수 프로젝트로 분류하였다. 생산성과 비용 측도 기준에 의해 분석한 결과 작은 팀 규모와 최소한의 개발기간이 소요되었을 때, 프로젝트가 성공적으로 수행됨을 보였다. 또한, 연구 결과에 근거하여 기능점수 규모에 따른 개발팀의 규모와 개발기간을 추정할 수 있는 모델을 제안하였다. 본 제안 모델은 소프트웨어 규모에 따라 필요한 개발팀의 규모와 개발기간 평가 기준을 제공한다.

• 한국정보과학회논문지:소프트웨어및응용
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• 제31권1호
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• pp.20-28
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• 2004

소프트웨어 개발 초기에 개발비용, 소묘인력과 기간을 추정하는 것은 소프트웨어공학 분야의 중요하면서도 어려운 문제이다. 기존 모델은 개발업체의 생산성 수준을 고려하지 않고 단순히 기능점수와 노력, 노력과 개발기간 관계에 대한 회귀분석을 통해 개발노력과 기간을 추정하는 모델을 제시하였다. 그러나 동일한 규모의 소프트웨어라도 개발업체의 생산성 수준에 따라 다른 노력의 양이 투입되며, 동일한 노력이 투입되더라도 생산성에 따라 개발기간이 달라진다. 생산성 수준을 고려하지 않은 제안된 모델들은 실제 개발될 프로젝트 적용에 제한점을 갖고 있다. 본 논문은 기존 모텔의 단점을 보완하기 위해 생산성을 고려하여 개발기간을 추정할 수 있는 모델들을 제안한다. 생산성에 기반 하여 다양한 방법으로 개발기간을 추정할 수 있는 모델을 제안하고 모델들의 성능을 비교하였다. 모델 성능 비교 결과 생산성에 기반 하여 소프트웨어 규모로부터 개발기간을 추정하는 모델이 단순하면서도 가장 좋은 결과를 얻었다. 본 모델은 사업 초기에 프로젝트 관리자에게 소프트웨어 개발 기간 의사결정 정보를 제공한다.

• Reproductive and Developmental Biology
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• 제28권4호
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• pp.221-226
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• 2004

The present study was performed to investigate the effects of in vitro maturation (IVM) and in vitro fertilization (IVF) duration on the development of Korean Native Cattle embryos. The time of blastocyst formation and the quality of blastocysts based on cell numbers were examined. The cleavage rate increased with the length of IVF duration in the groups of 18-hr IVM, but was constant in the groups of 24-hr IVM. The development rate to the 8-cell stage was significantly higher in the IVM 18: IVF 20 group than in the IVM 24: IVF 24 group. The development rate to the blastocyst stage was highest in the IVM 18: IVF 20 group, significantly different from that of the IVM 18: IVF 16, IVM 24: IVF 20 and IVM 24: IVF 24 group. The time of blastocysts formation tended to be shorter when IVM and IVF duration were decreased. The number of inner cell mass, trophoblast and the total cells were significantly higher in the IVM 18: IVF 16 group than in the IVM 24: IVF 24 group (P<0.05). These results demonstrated that the IVM and IVF duration should be adequate for the efficient production of bovine embryos, and it might particularly be essential to determine the proper combination of IVM and IVF duration.

• 한국건축시공학회:학술대회논문집
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• 한국건축시공학회 2009년도 춘계 학술논문 발표대회 학계
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• pp.159-162
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• 2009

Today's construction is more various and more complex. Because of that, a lot of uncertain factors are occurred and they related uncertain construction duration. For management complex architecture project, importance of construction schedule management also increased. In previous studies, one of solutions to overcome those problems is suggested. It was BIM based construction simulation process which focused on construction schedule and construction schedule management. But latest process had limited point which has no duration estimation function. So this paper suggested duration estimation method and developed duration estimation module. Duration estimation module developed with current scheduling tool MS Project and their macro function. However, this module has just developed Reinforced Concrete Structure and has to do more development and research.

• 한국환경과학회지
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• 제4권2호
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• pp.117-120
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• 1995

The comparision of sunshine duration meter was carried out on the roof of Korea Meteorological Research Institude by comparing Pyrheliometer(Eppley NIP model) to sunshine duration meter(Reflection type) during from Nov. 8, 1989 to Feb. 19, 1990. In the observation Period, daily mean sunshine duration time difference of Jordan sunshine duration meter was recorded 0.47hour and Reflect sunshine duration meter was recorded 0.39hour. More than one hour time difference was observed 15 cases by Jordan sunshine duration meter and 11 cases by Reflect sunshine duration meter.

• 한국군사과학기술학회지
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• 제17권5호
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• pp.620-628
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• 2014

This paper describes the analysis results of channel characteristics in the operating area of satellite OTM (On-The-Move) terminal. The communication channel between the Koreasat-5 and OTM terminal on a test car was measured and recorded in downtown of Daejeon, using the received beacon signal of around 20 GHz. And the measurement data were statistically analyzed and then compared with highway and national road environments. The statistical evaluation of satellite channel was conducted by using probability density function and Markov model and then presented average connection duration(ACD), average fade duration(AFD), and level crossing rate(LCR) of downtown environment.

• 국제학술발표논문집
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• The 3th International Conference on Construction Engineering and Project Management
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• pp.493-498
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• 2009

Recently, the number of complex construction projects, such as high-density development and long-span mega structure construction, has been increasing globally. Therefore, the construction duration has become an even more important factor for success. Nevertheless, in domestic residential construction projects, it usually takes more time than twice as much as North American cases. The long construction duration causes a number of problems, for example growth of financial costs, fall in productivity, and weakness of competitiveness. If the framework construction duration can be shortened to 3 ~ 4 days, then it is also expected to complete the finish work of building in shorter duration, be led to reduce the entire construction duration, and eventually to save a great deal of indirect costs. For shortening the construction duration, previous researches pointed out that the development of simplified plan design should precedes. But, in reality, lack of experience of new design and innovative techniques tends to be the obstacle to wide adoption of the simplified plan design in construction fields. In this paper, a simplified structural plan design is proposed, and the construction cost is quantitatively compared between when traditional construction technique is applied to the traditional plan and when the duration-shortening key technique is applied to the developed plan.