• 농업과학연구
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• 제42권4호
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• pp.355-359
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• 2015

The cause of infertility is either fertilization failure or early embryonic death. The aetiology may involve a combination of many factors, e.g. genetic factors, abnormalities in the gametes nutritional disorders, inadequate luteal function, and delayed ovulation. This study was conducted to investigate the effect of microorganisms collected from uterus of Hanwoo cattle on early embryonic development. Microorganisms isolated from the uterus of Hanwoo cattle included Bacillus cereus (Bc), Bacillus thuringiensis (Bt), Staphylococcus warneri (Sw) and Enterococcus faecalis (Ef). When cultured with Bc, Bt, Sw, and Ef, oocytes were not developed into a blastocyst in vitro. The proportion of blastocyst was dramatically increased after reducing the number of microorganisms ($10^4CFU/ml$). Interestingly, the proportion of blastocyst was decreased by adding the Sw and Ef. These results indicate that among intrauterine microorganisms, Sw and Ef strains negatively affect theearly embryonic development, thereby aggravate the rates of implantation and pregnancy. These findings will provide useful information for association studies in other pig populations.

• Pediatric Gastroenterology, Hepatology & Nutrition
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• 제22권6호
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• pp.536-544
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• 2019

Purpose: Proper nutrition is essential for brain development during infancy, contributing to the continued development of cognitive, motor, and socio-emotional skills throughout life. Considering the insufficient published data in the Middle East and North Africa, experts drafted a questionnaire to assess the opinions and knowledge of physicians on the impact of nutrition on brain development and cognition in early life. Methods: The questionnaire consisted of two parts: The first focused on the responders' demographic and professional characteristics and the second questioned the role of nutrition in brain development and cognition. Descriptive statistics were used to summarize respondents' characteristics and their responses to questions. Results: A total of 1,500 questionnaires were distributed; 994 physicians responded. The majority of the surveyed physicians (64.4%) felt that nutrition impacts brain development in early childhood (0-4 years), with almost 90% of physicians agreeing/strongly agreeing that preventing iron, zinc, and iodine deficiency would improve global intelligence quotient. The majority of physicians (83%) agreed that head circumference was the most important measure of brain development. The majority of physicians (68.9%) responded that the period from the last trimester until 18 months postdelivery was crucial for brain growth and neurodevelopment, with 76.8% believing that infants breast-fed by vegan mothers have an increased risk of impaired brain development. Conclusion: The results of this study show that practicing physicians significantly agree that nutrition plays an important role in brain and cognitive development and function in early childhood, particularly during the last trimester until 18 months postdelivery.

• 한국가축번식학회지
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• 제13권2호
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• pp.98-104
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• 1989

Successful techniques of in vitro fertilization(IVF) are valuable for studying the process of fertilization and for developing economical procedures for gene and nuclear transfer in farm animals. To date, bovine IVF system has been developed with oocytes in vitro or vitro, but the resulting zygotes exhibit limited embryonic development after in vitro culture. Even though in vitro matured oocytes achieved high fertilization and cleavage rates, these embryos appear extremly low rate of pregnancies when transferred to synchronized recipients. Development of early bovine embryos in vitro is generally arrested at the 8-to 16-cell stage. However, recent use of somatic cells such as trophoblastic vesicle, granulosa and oviduct epithelial cell for co-culture with early bovine embryos has proven effective for development of embryos, matured and fertilized in vitro, past the in vitro cell blocks. These factors clearly indicate the value of the co-culture system in promoting development of bovine oocytes matured and fertilized in vitro to morula or blastocyst stage in vitro. In addition, co-culture system may beome a tool for evaluation of viability of ova that have been manipulated by procedures such as splitting, microinjection and nuclear transfer.

• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 1997년도 봄 학술발표회 논문집
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• pp.118-123
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• 1997

The strength development of Flyash concrete containing various amount of Flyash (0, 10, 30, 50%) using as a cement replacement material was investigated two types of curing conditions, namely water curing at $21^{\cire}C$ and steam curing at $25^{\cire}C$ were adopted for this work, in water curing the strength development of Flyash concrete was always inferior to that of OPC (Ordinary Portland Cement) concrete at early ages, although the differences were dependant up percentage of Flyash. The strength of Flyash concrete based on equivalent strength development at 28 days was also tested and the results exhibited that the strength was improved at early days, specially, the concrete containing 30% of Flyash, in steam curing for the same mix(270kg/$\textrm{cm}^2$) the strength of Flyash concrete similar to that of OPC concrete, in other words. Flyash was strongly influenced by curing temperature in the strength development.

• 한국환경과학회지
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• 제19권1호
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• pp.105-114
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• 2010

The objective of the paper is to experimentally investigate the compressive strength of the concrete incorporating fly ash. Ordinary Portland cement(OPC). Water to binder ratio(W/B) ranging from 30% to 60% and curing temperature ranging from $-10^{\circ}{\sim}65^{\circ}C$ were also adopted for experimental parameters. Fly ash was replaced by 30% of cement contents. According to the results, strength development of concrete contained with fly ash is lower than that of plain concrete in low temperature at early age and maturity. In high curing temperature, the concrete with fly ash has higher strength development than that of low temperature regardless of the elapse of age and maturity. Fly ash can have much effect on the strength development of concrete at the condition of mass concrete, hot weather concreting and the concrete products for the steam curing.

• 산업공학
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• 제19권1호
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• pp.19-25
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• 2006

In the development process, the objective of a reliability growth program is to track the increase in system reliability, and determine as early as possible whether or not the system reliability is growing at a sufficient rate to meet the required goal and allocate available resources accordingly. Implementation of this kind of program will provide very useful information on concept selection, product/process reliability, and cost effectiveness without too much time, money and engineering effort being spent on the development of failure suspect parts. The purpose of this research is to present a practical method for efficiently monitoring a reliability growth test process using AMSAA(Army Materiel Systems Analysis Activity) reliability growth model. The presented growth management is a viable method for identifying failure modes, incorporating design changes and monitoring reliability progress on an on-going basis during the early stages of a product development program.

• 한국보육지원학회지
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• 제12권4호
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• pp.151-181
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• 2016

This study examined professional development systems in America, England, and Australia, and devised ways to enhance early childhood teachers' professional development in Korea. To suggest effective ways to improve current professional development system and its operation, this research aimed to investigate first, advanced professional development systems and policies in three countries, America, England, and Australia, second, the process of teacher qualification and requirements for acquiring teacher credential and its maintenance, and lastly, the effort of quality control for professional development, its operation, and evaluation systems in three countries. Based on the analysis of the three country's systems, five solutions for effective professional development are suggested. First, it is necessary to differentiate requirements for teachers by the level of teacher credentials. Second, an incessant training process for professional development is required. Third, an individualized professional development plan should be set for an individual teacher for the best outcomes in professional competence. Fourth, instructors for professional development trainings are needed to ensure the quality of training. Lastly, individuals, organizations, and policy and its operation systems need to be considered holistically as a whole in the perspective of convergence in policy making and its operation for effective professional development.

• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 2002년도 가을 학술발표회 논문집
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• pp.695-702
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• 2002

Shotcrete (or Sprayed concrete) has been used as an important support material in New Austrian Tunnelling Method (NATM). Since the mid of 1990, permanent shotcrete tunnel linings such as Single-shell, NMT (Norwegian Method of Tunnelling) has been constructed in many countries for reducing the construction time and lowing construction costs instead of conventional in-situ concrete linings. Among essential technologies for successful application of permanent shotcrcte linings, high performance shotcrete providing high strength, high durability, better pumpability has to be developed in advance as an integral component. This paper presents the Ideas and first experimental attempts to increase early strength and bond strength of wet-mixed Steel Fiber Reinforced Shotcrete(SFRS) in sump water condition. In order to increase early strength, a new approach using high-early strength cement with liquid alkali-free accelerator has been investigated From the results, wet-mix SFRS with high-early strength cement and alkali-free accelerator exhibited excellent early strength improvement compared to the ordinary portland content and good bond strength even under sump water condition.

• 아동학회지
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• 제32권4호
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• pp.37-62
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• 2011

The purpose of this study was to develop an appropriate scale for evaluating early years children's English textbooks and to confirm the validity and reliability for the scale thus developed. The scale was administered to 563 Korean early childhood English teachers. Exploratory Factor Analysis (EFA) of the 24 item scale demonstrated Cronbach' ${\alpha}$ = .94 for internal consistency of the total items. Confimatory Factor Analysis (CFA) supported a four-factor structure. Cross-Validation for the retest accepted the four-factors. Those four factors were as follows; Contents & Organization as factor 1, Illustrations & Designs as factor 2, Materials & Topics, as factor 3 and Objectives as factor 4. The author suggests that these afore mentioned factors will prove to be most useful for evaluating the children's English textbooks which are apparently published in an often quite indiscriminant manner.

• 한국생활과학회지
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• 제21권5호
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• pp.819-835
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• 2012

The purpose of this study was to develop and test the validity of an assessment scale for determining the competency of early childhood teachers practicing unification education. For this purpose, an evaluation scale was constructed and then tested for reliability and validity. Participants for this study included 266 early childhood teachers in the unification education field. In order to the measure reliability and validity of this scale, Exploratory Factor Analysis and Confirmatory Factor Analysis were conducted with SPSS 18.0 and AMOS. The result of this study identified four principal factors: 1) Instruction skills, 2) Evaluation, 3) Attitude, and 4) Knowledge. The results of this study supported the scale's reliability and legitimacy as a valid instrument for the evaluation of early childhood teacher's competence in unification education.