• 제목/요약/키워드: early ages

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나노실리카와 나노칼사이트 혼입 석회석 소성 점토 시멘트(LC3) 페이스트의 기계적 성능 평가 (Assessment of the Mechanical Performance of Nano-Silica and Nano-Calcite Incorporated Limestone Calcined Clay Cement (LC3) Paste)

  • 김경률;조성민;배성철
    • 한국건축시공학회:학술대회논문집
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    • 한국건축시공학회 2023년도 봄 학술논문 발표대회
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    • pp.151-152
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    • 2023
  • This study investigates the effect of nano-silica and nano-calcite on the hydration properties and mechanical performance of limestone calcined clay cement (LC3) paste. The pastes were synthesized by replacing limestone with nano-silica and nano-calcite in order to enhance the mechanical properties in both early and late stages of hydration. The nano-calcite enhanced the strength of LC3 pastes at 1 day of hydration, however, the strength decreased compared to the ordinary LC3 pastes afterwards due to excessive amount of carboaluminate produced in the pastes. On the other hand, nano-silica improved the mechanical properties of LC3 pastes at all ages of hydration. This is mainly due to the nucleation effect and pozzolanic reaction of nano-silica, affecting the early age and late ages of hydration, respectively. The nucleation effect of both nanomaterials were confirmed by the analysis of hydration heat, supporting the enhanced early age strength of nanomaterial incorporated LC3 pastes. Furthermore, the dense matrix was shown in the pore size distribution, and the increased C-S-H due to the pozzolanic reaction evidence the improved compressive and splitting tensile strength of nano-silica incorporated LC3 pastes.

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초등학생의 과체중 이환율 추적과 관련요인 분석 (Overweight Tracking in Primary Schoolchildren and Analysis of Related Factors)

  • 윤군애
    • Journal of Nutrition and Health
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    • 제35권1호
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    • pp.69-77
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    • 2002
  • The purpose of this study was to determine the probability of overweight throughout childhood in relation to the presence of overweight at birch or in early childhood, and presence of overweight in children's parents. Weight and height measures were collected at birth and at ages of 7, 10, 12 years from 655 6th grade primary schoolchildren. Childhood overweight was defined as a body mass index at or above the 85th percentile for age and sex, and overweight in children's parents as a body mass index at or above 27. The prevalence of overweight increased with age of the children. Overweight at birth was not associated with overweight at 12 years of ages. However, overweight at 12 years old was already related to overweight at 7 years old. In comparison to non-overweight peers, overweight children at ages 7(OR = 7.64, 95% CI = 4.32-13.51) and 10 years(OR = 19.69, 95% CI = 11.42-33.94) had a higher rick of becoming overweight at 12 years of age. Among children who was overweight at age 7years, 60.7% remained overweight 5 years later, Yearly increment in BMI of overweight children was larger than that of non-obese children (1.15-1.65kg/m$^2$vs 0.50-0.71kg/m$^2$. As compared with the lower case in mealy increment of BMI, the probability of being overweight at age of 12 years was greater in higher case. BMI values at age 7years were positively correlated with BMI values at age of 10 and 127ear,i, and with annual increments in BMI. But those relationships with birth weight were not observed. Children were at greater risk for overweight if at least ogle parent was overweight. The odds ratio for child overweight associated with maternal overweight was 2.41(95% CI = 1,13-5.IS), and those associated with paternal overweight 1.70(95% CI = 0.92-3.17). And parents' BMIs were positively correlated with children's BMI values and yearly BMI increment. In conclusion, overweight at early childhood and annual inclement in BMI can be important in predicting the prevalence of overweight and the risk that overweight will remain after 7 years of age. The risk of being overweight throughout the childhood increases by the parents'overweight.

Complete Blood Count Reference Intervals and Patterns of Changes Across Pediatric, Adult, and Geriatric Ages in Korea

  • Nah, Eun-Hee;Kim, Suyoung;Cho, Seon;Cho, Han-Ik
    • Annals of Laboratory Medicine
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    • 제38권6호
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    • pp.503-511
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    • 2018
  • Background: Sampling a healthy reference population to generate reference intervals (RIs) for complete blood count (CBC) parameters is not common for pediatric and geriatric ages. We established age- and sex-specific RIs for CBC parameters across pediatric, adult, and geriatric ages using secondary data, evaluating patterns of changes in CBC parameters. Methods: The reference population comprised 804,623 health examinees (66,611 aged 3-17 years; 564,280 aged 18-59 years; 173,732 aged 60-99 years), and, we excluded 22,766 examinees after outlier testing. The CBC parameters (red blood cell [RBC], white blood cell [WBC], and platelet parameters) from 781,857 examinees were studied. We determined statistically significant partitions of age and sex, and calculated RIs according to the CLSI C28-A3 guidelines. Results: RBC parameters increased with age until adulthood and decreased with age in males, but increased before puberty and then decreased with age in females. WBC and platelet counts were the highest in early childhood and decreased with age. Sex differences in each age group were noted: WBC count was higher in males than in females during adulthood, but platelet count was higher in females than in males from puberty onwards (P <0.001). Neutrophil count was the lowest in early childhood and increased with age. Lymphocyte count decreased with age after peaking in early childhood. Eosinophil count was the highest in childhood and higher in males than in females. Monocyte count was higher in males than in females (P <0.001). Conclusions: We provide comprehensive age- and sex-specific RIs for CBC parameters, which show dynamic changes with both age and sex.

뇌성마비의 조기치료에 관한 문헌적 고찰 - 최근 중의 잡지 중심으로 - (A Literary Review on Early Treatment of Cerebral Palsy - Centered on the Chinese Medical Journal -)

  • 곡수영;이승연;유선애
    • 대한한방소아과학회지
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    • 제22권3호
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    • pp.35-62
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    • 2008
  • Objectives : This study has been carried out to look into the methods of early treatment of cerebral palsy and the treatment effect by ages. Methods : The fifteen theses dealing with treatment effects by ages were analyzed, which were selected from the 121 theses retrieved out of the wu-ruan(五軟), wu-chi(五遲), wu-ying(五硬), naotan(腦癱), naoxing-tanhuan(腦性癱癱), during the period between the January 2004 to August 2008 by using the China Academic Journal(CAJ) of China National Knowledge Infrastructure(CNKI). Results : 1. Among the study objects in the 15 theses, it was identified that there were 1.97 times more boys with cerebral palsy than that of girls, and it appeared that there was no significant relationship between gender and the treatment. 2. The early treatment referred to the treatment which was carried out based on the early diagnosis within 6 months to one year after the birth. This is the time when the adaptability and plasticity of the brain are high, and it was found out that the treatment effective as babies are young. 3. For the treatment of cerebral palsy, the combination of Traditional Chinese and Western Medicine Therapy was more frequently used than the exclusive Chinese medical treatment method, and it was more effective. Especially in the case, the Chinese medical treatment was focused on the acupuncture and the Tuina Massage. Conclusions : 1. For the treatment of cerebral palsy, when the age between one and two years old was established as the standard. The younger the babies were, the higher treatment effects were obtained. 2. It appeared that the early treatment of oriental medicine had relatively excellent effects on cerebral palsy, but it turned out that we needed more studies for accurate results.

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미국인의 조기퇴직 역전현상과 고령자 사회정책의 미래 (A Reversal in Retirement Ages and the Future of Social Policy in the United States)

  • 전광희
    • 한국인구학
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    • 제26권1호
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    • pp.115-141
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    • 2003
  • 본 연구의 목적은 미국 인구의 고령화 과정에서 장기적인 조기퇴직의 경향과 1985년 이후 일어난 그것의 역전현상에 주목하면서, 그것에 기여하는 사회경제적 여건과 사회정책 프로그램의 변화를 검토하는 것이다. 미국인의 조기퇴직, 곧 퇴직연령 하락의 주원인은 장기적인 부(富)의 증대이며, 이것은 고령 노동자들이 소득창출을 위한 유급노동시장 참여를 하지 않고서도 높은 수준의 생활을 가능하도록 하였다. 사회보장 퇴직연금과 기업 연금제도의 확대 성장은 강제퇴직제도의 도입과 아울러 1980년대 중반까지 조직퇴직의 증가추이에 공헌하였다. 본 연구는 최근의 조기퇴직 역전현상을 지속시킬 수 있는 유인책으로서 고령자 사회정책 프로그램 등에 주목한다. 물론, 여기서 과연 조기퇴직의 역전을 가져오는 사회정책이 필요한가에 대한 질문이다. 환언하면, 노동생산성의 증대나 은퇴전의 근면성(勤勉性)의 향상은 미국인들이 평균수명의 신장으로 퇴직, 곧 "제3의 인생" 이 길어진다고 하더라도 보다 높은 사회생활을 유지하는데 아무런 어려움이 없을 것임을 의미한다. 대부분의 미국인은 현행 각종 사회정책 프로그램이 현역 노동자들에게 상당한 부담을 가져다주더라도 조기퇴직을 허용하는 각종 사회정책 프로그램이 유지되기를 원하고 있다. 이러한 관점에서 볼 때, 미국의 고령자 사회정책은 조기퇴직의 역전을 지속하려는 정책을 계속하기보다는 현역 노동자의 근면성 향상이나 노동생산성의 향상에 초점을 맞추는 프로그램의 개발에도 관심을 집중할 필요가 있을 것이다.요가 있을 것이다.

근대 연길도심지구의 형성과 발전과정 (The Formation and Development Process of Yanji Urban Area in Modern Ages(1870-1949))

  • 박세영;김태영
    • 한국농촌건축학회논문집
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    • 제8권2호
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    • pp.72-79
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    • 2006
  • This study is to find out formation and development process of urban area in modern ages(1870-1949) focused Yanji city in the east-northern area in china. After the discharge of confinement in the late 19 century, the settlements were formed around east area, that is, the present Yanji urban area. The japanese consular office had been moved in east area since the beginning of the early 20 century, and so, the existing residents moved to west area. And the military and administrative facilities were located on the urban outskirts. After the September 18th Incident on 1932, Yanji had been constructed with the strategic center area under the urban planning. The administrative facilities of those days had been altered to he functional branches and educational facilities, and become the basis of development of Yanji city.

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Testing Whether New Is Better Than Used of Specified Age Using Moments Inequalities

  • Ahmad, Ibrahim A.;Al-Wasel, Ibrahim A.
    • International Journal of Reliability and Applications
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    • 제3권1호
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    • pp.17-23
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    • 2002
  • The class of “new better than used of a specified age” is a large and practical class of life distributions. Its properties, applicability, and testing was discussed by Hollander, Park and Proschan (1986). Their test, while remaining the yardstick for this class, suffers from weak efficiency and weak power, especially for specified ages below the average age. Thus, it is beneficial to have an alternative testing procedure that would work better for early ages and still work well for later ages. This is exactly the subject of the current note. The test developed here is also simpler than that of Hollander, et. al. (1986).

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강섬유 보강 콘크리트의 조기 재령에서의 휨 인성 발현에 관한 연구 (Investigation of Flexural Toughness Development of Steel Fiber Reinforced Concrete at Early Ages)

  • 이창준;신성우
    • 한국안전학회지
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    • 제24권6호
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    • pp.103-110
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    • 2009
  • Since the mechanical properties of cement-based materials are time-dependent due to the prolonged cement hydration process, those of fiber reinforced concrete(FRC) may also be time-dependent. Toughness is one of important properties of FRC. Therefore, it should be investigated toughness development of FRCs with curing ages to fully understand the time-dependent characteristics of FRCs. To this end, the effect of curing ages on flexural toughness development of steel fiber reinforced concrete is studied. Three point bending test with notched beam specimen was adapted for this study. Hooked-end steel fiber(DRAMIX 40/30) was used as a fiber ingredient to investigate w/c ratio and fiber volume fraction effect on toughness development during curing. Three different water-cement ratios(0.44, 0.5 and 0.6) and fiber volume fractions(0%, 0.5% and 1%) were used as influence factors. Each mixture specimens were tested at five different ages, 0.5, 1, 3, 7 and 28 days. The study shows that flexure toughness development with age is quite different than other concrete material properties such as compressive strength. The study also shows that the toughness development trend correlates more closely to water/cement ratio than to fiber volume fraction.

건축공간-형태의 이론과 변천에 관한 연구 (A Study on the Theories and Changes of Architectural Spatial Form)

  • 이기승;윤도근
    • 한국실내디자인학회논문집
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    • 제13호
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    • pp.238-248
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    • 1997
  • The spatial form of architecture in the same era has its own common characteristic spatial form. This study is based on this proposition and is focused on how architectural spatial forms have been changed up to now after modern ages(from the beinging of 1900s to the early days of 1990s ; from early modern age, golden modern age, post modern, late modern architecture to recent experimental trend) and how architectural theories of spatial forms will be changed in the future is predicted.

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한국 동남부 마이오세 분지 화산암과 기반암의 피션트랙 연대 재검토와 연대층서 고찰 (Revised Fission-track Ages and Chronostratigraphies of the Miocene Basin-fill Volcanics and Basements, SE Korea)

  • 신성천
    • 암석학회지
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    • 제22권2호
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    • pp.83-115
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    • 2013
  • 피션트랙(fission-track: FT) 연대측정 초기단계의 부적합한 연대보정법에 기인한 오류 원인을 정밀진단하고, 중복시료에 의한 재실험과 제타보정법에 의해 최초 보고된 피션트랙(FT) 연대를 재정의한다. 재검토된 FT 저콘연대는 기반암인 유천층군 유문암질-데사이트질응회암의 생성연대를 후기 백악기부터 고제3기 초($78{\pm}4$ Ma부터 $65{\pm}2$ Ma)로 재정의하며, 곡강동유문암질응회암을 전기 에오세($52.1{\pm}2.3$ Ma) 산물로 정의한다. 전기 마이오세 화산암의 경우, 효동리화산암류 상부 데사이트질응회암($21.6{\pm}1.4$ Ma)과 범곡리화산암류 최상부 데사이트 용암($21.3{\pm}2.0$ Ma)의 FT 저콘연대는 각각 어일분지 남부와 와읍분지 중앙부의 상부 범곡리층군의 연대층서를, 그리고 금오리데사이트질응회암($19.8{\pm}1.6$ Ma)의 FT 저콘연대는 장기분지 내 후기 데사이트질 화산활동 시기를 정의한다. 데사이트질암의 FT 저콘연대와 현무암질-안산암질암의 기존 연대자료(대부분 K-Ar 전암, 일부 Ar-Ar)를 기반으로 하여, 한국 동남부의 마이오세 분지의 화산암과 기반암의 층서대비에 길잡이가 될 수 있는 참고연대를 설정 제안한다. 관계화산암의 연대에 기반하여 분지충전 퇴적지층의 퇴적시기도 추정한다. 제안된 참고연대는 마이오세 분지의 복잡한 분지구조와 비교적 짧은 연대범위에도 불구하고 지질층서에 잘 부합된다. 범곡리층군은 어일-와읍분지에서 장기층군보다 하위인 것이 확실하나, 장기분지의 전기 장기층군과 상당부분 중첩 병립되므로, 두 층군을 획일적으로 선후관계로 정의할 수는 없다. 장기분지에서 장기층군 하나로 묶여있는 일련의 지층군은 약 20 Ma를 기준으로 전기(23-20 Ma)의 안산암질-데사이트질암과 후기(20-18 Ma)의 현무암질암으로 뚜렷하게 구분된다.