• 제목/요약/키워드: Mean period

검색결과 5,863건 처리시간 0.03초

사춘기 초기 여자 어린이의 골질량 변화와 이에 영향을 미치는 요인 분석 (Factors Associated with Changes in Bone Mineral Content among Girls in Early Pubertal Age)

  • 윤소윤;박민경;백희영;정효지
    • Journal of Nutrition and Health
    • /
    • 제40권1호
    • /
    • pp.69-77
    • /
    • 2007
  • The study was conducted to investigate the factors associated with bone mineral content (BMC) changes among early pubertal aged girls. Two hundred and thirty girls between 9 to 11 years of age participated in (our surveys over 2 year period. During each survey, dietary intakes were collected with 3-day food records, BMC of left leg's calcaneus were measured by PIXI (Lunar Ltd.) and body composition was measured by bioimpedance method (Inbody 3.0 Biospace Co. Ltd, Seoul, Korea). Mean values of BMC increased in consecutive measurements -1.48 g, 1.54 g, 1.61 g and 1.66 g. The change of BMC between the first and last measurements was significantly positively correlated with % body fat, negatively correlated with BMC at the baseline (p < 0.05). Change of BMC was also significantly positively correlated with % change of lean mass and mineral mass between the first and last measurements. Nutrient intakes during the study period were calculated as mean daily intakes from all surveys. Mean daily intakes of Vit. C and Vit. $B_6$ were positively and isoflavone intake was negatively correlated with changes of BMC (p < 0.05). In stepwise regression of BMC change with body composition and nutrient intakes, baseline values of BMC, weight, BMI and age, % change of mineral mass during the study period, mean intakes of isoflavone, Vit. $B_6$, protein, carotene and zinc were significant explanatory variables ($R^2=0.38$, p <.001, F = 32.39). The results imply that the change of BMC among early pubertal aged girls are associated with some body composition and intakes of certain nutrients.

급격한 평균유속 변동에 의한 관내 Air/$C_3$$H_8$ 예혼합 화염의 소화특성에 관한 실험적 연구 (An Experimental Study on the Flame Characteristics of the Air/$C_3$$H_8$ Premixed Flame Using Large Axial Mean Velocity Variation)

  • 김남일;이은도;신현동
    • 대한기계학회논문집B
    • /
    • 제25권4호
    • /
    • pp.540-545
    • /
    • 2001
  • Many previous researches on the premixed flame in a tube have treated the unsteady flame behaviors in which the shape, position and intensity of the flame varied, but more detail and fundamental research has been necessary. The flame stabilization condition in a tube, a unique steady state, and the unsteady behaviors, using the stabilization condition as an initial condition, were carried out in recent years. In this paper, propane-air premixed flame was stabilized in a tube and the flame behavior was observed when the mean velocity variation was imposed into the opposite direction of the initial mean velocity. The velocity variation is larger than the burning velocity and longer than the reaction time scale. During the period of the velocity variation flame is not extinguished. But after the period of the mean velocity variation the flame could be re-stabilized or be extinguished depending on the experimental conditions: equivalence ratio, period of velocity variation and magnitude of velocity variation. The extinction mechanisms were classified into the two cases, one is caused by the flame stretch in the shear layer near the wall, and the other is caused by the vortices and vortexes, which are generted by the acoustic waves.

2012 BDI의 예측 (Forecasting the BDI during the Period of 2012)

  • 모수원
    • 한국항만경제학회지
    • /
    • 제27권4호
    • /
    • pp.1-11
    • /
    • 2011
  • 미국 신용등급 하락 이후 미국의 더블딥 우려와 유럽 재정위기가 세계 경제를 크게 뒤흔들고 있다. 미국의 재정적자가 심각한 수준에 도달하여 재정정책수단이 제대로 작용하지 못하고 유럽의 일부 국가에서도 재정위기 가능성이 상존하여 실물위기로 파급될 가능성이 높다. 이러한 점들은 세계경제가 내년에도 상당한 불확실성을 보일 것이라는 것을 의미한다. 세계경제에 대한 전망이 밝지 못한 가운데 해운경기는 세계 경기와 밀접한 관계가 있기 때문에 어두운 전망의 세계경제는 해운경기 역시 밝지 않을 것이라는 것을 쉽게 예측할 수 있다. 본고는 2012년의 해운경기를 예측하기 위하여 단변량 모형인 4개의 ARIMA 모형과 6개의 개입ARIMA모형을 이용한다. 먼저 사후적 예측을 하여 10개의 모형의 RMSPE가 비교적 높을 뿐만 아니라 일부 모형에서는 상당히 높아 ARIMA모형에 의한 예측이 어려움을 의미한다. 사전적 예측을 통해 모형들의 예측치가 큰 차이를 보이지 않으며 그러나 2012년 예측치가 모형 4개의 최대 2178-2320, 모형 6개의 최대 2071-2533에 불과하여 해운경기가 여전히 불황에서 벗어나기 어려울 것이라는 것을 보인다.

1904년 이래의 부산 기후 변동성 및 생활기상지수들의 기후변화 특성 연구 (A Study on Characteristics of Climate Variability and Changes in Weather Indexes in Busan Since 1904)

  • 전하은;하경자;김혜렴
    • 대기
    • /
    • 제33권1호
    • /
    • pp.1-20
    • /
    • 2023
  • Holding the longest observation data from April 1904, Busan is one of the essential points to understand the climate variability of the Korean Peninsula without missing data since implementing the modern weather observation of the South Korea. Busan is featured by coastal areas and affected by various climate factors and fluctuations. This study aims to investigate climate variability and changes in climatic variables, extremes, and several weather indexes. The statistically significant change points in daily mean rainfall intensity and temperature were found in 1964 and 1965. Based on the change point detection, 117 years were divided into two periods for daily mean rainfall intensity and temperature, respectively. In the long-term temperature analysis of Busan, the increasing trend of the daily maximum temperature during the period of 1965~2021 was larger than the daily mean temperature and the daily minimum temperature. Applying Ensemble Empirical Mode Decomposition, daily maximum temperature is largely affected by the decadal variability compared to the daily mean and minimum temperature. In addition, the trend of daily precipitation intensity from 1964~2021 shows a value of about 0.50 mm day-1, suggesting that the rainfall intensity has increased compared to the preceding period. The results in extremes analysis demonstrate that return values of both extreme temperatures and precipitation show higher values in the latter than in the former period, indicating that the intensity of the current extreme phenomenon increases. For Wet-Bulb Globe Temperature (effective humidity), increasing (decreasing) trend is significant in Busan with the second (third)-largest change among four stations.

Horizontal ridge augmentation with porcine bone-derived grafting material: a long-term retrospective clinical study with more than 5 years of follow-up

  • Jin-Won Choi;Soo-Shin Hwang;Pil-Young Yun;Young-Kyun Kim
    • Journal of the Korean Association of Oral and Maxillofacial Surgeons
    • /
    • 제49권6호
    • /
    • pp.324-331
    • /
    • 2023
  • Objectives: The purpose of this study was to evaluate the outcomes of implants placed in horizontally augmented alveolar ridges using porcine bone grafts and to investigate the long-term stability of the porcine bone grafts. Materials and Methods: A retrospective analysis was conducted on 49 sites that underwent horizontal ridge augmentation using porcine bone grafts and implant placement with a follow-up period longer than 5 years. Furthermore, additional analysis was conducted on 24 sites where porcine bone grafts were used exclusively for horizontal ridge augmentation and implant placement. Results: The mean follow-up period after prosthesis loading was 67.5 months, with a mean marginal bone loss of 0.23 mm at 1 year and a cumulative mean marginal bone loss of 0.40 mm over the entire follow-up period. Of the 49 implants, 2 were lost and 3 did not meet the success criteria, resulting in a survival rate of 95.9% and a success rate of 89.8%. In 24 sites, the mean marginal bone loss was 0.23 mm at 1 year and 0.41 mm at 65.8 months, with 100% survival and success rates. Conclusion: Porcine bone grafts can be successfully used in horizontal ridge augmentation for implant placement in cases of ridges with insufficient horizontal width.

Effect of Three Different Species of Hay on Dry-matter Intake and Serum Cortisol of Ewes

  • Sekine, J.;Abdel-Rahman, Mootaz A.M.;Ismail, A.El-Moez A.;Dosoky, R.M.;Kamel, H.E.M.;Hishinuma, M.
    • Asian-Australasian Journal of Animal Sciences
    • /
    • 제16권9호
    • /
    • pp.1297-1302
    • /
    • 2003
  • To determine whether the feeding of different species of hay affects the dry-matter intake and the serum cortisol level of sheep, 6 non-pregnant, non-lactating ewes were offered alfalfa (Medicago sativa) hay (Al), oats (Avena sativa) hay (Ot) and perennial ryegrass (Lolium perenne) hay (Pr) under 6 kinds of treatment including 1) change from Al to Ot, 2) Al to Pr, 3) Ot to Al, 4) Ot to Pr, 5) Pr to Al, and 6) Pr to Ot. The experimental design was a 6${\times}$6 Latin square with a 14 day period of which 9 days were a preliminary period and 5 days as a digestion trial period. The change in hay feeding was done abruptly on the first day of each period without an adaptation period. The blood from the jugular vein was collected on the first, third and the last day of each period through a sterile catheter for the analysis of cortisol. The dry-matter intake was recorded daily throughout the period. The mean daily intake of dry matter (DM, g/kg live weight) was significantly different among the 3 species of hay (Al>Ot>Pr; p<0.05). The digestibility of DM for Al and Ot was the same, but that for Pr was significantly lower than Al and Ot (p<0.05). The mean serum cortisol levels were significantly different among the hays (p<0.05). The level for Pr was the highest and that for Al was the lowest. The abrupt change of hay feeding of 6 treatments produced a significant change in the serum cortisol levels. The DM intake was inversely related to the change of the cortisol level. It is suggested that the animal' intake response to different species of hay may be partly motivated by the psychological feelings toward the hay offered.

기후변화에 따른 강수 특성 변화 분석을 위한 대규모 기후 앙상블 모의자료 적용 (Application of the Large-scale Climate Ensemble Simulations to Analysis on Changes of Precipitation Trend Caused by Global Climate Change)

  • 김영규;손민우
    • 대기
    • /
    • 제32권1호
    • /
    • pp.1-15
    • /
    • 2022
  • Recently, Japan's Meteorological Research Institute presented the d4PDF database (Database for Policy Decision-Making for Future Climate Change, d4PDF) through large-scale climate ensemble simulations to overcome uncertainty arising from variability when the general circulation model represents extreme-scale precipitation. In this study, the change of precipitation characteristics between the historical and future climate conditions in the Yongdam-dam basin was analyzed using the d4PDF data. The result shows that annual mean precipitation and seasonal mean precipitation increased by more than 10% in future climate conditions. This study also performed an analysis on the change of the return period rainfall. The annual maximum daily rainfall was extracted for each climatic condition, and the rainfall with each return period was estimated. In this process, we represent the extreme-scale rainfall corresponding to a very long return period without any statistical model and method as the d4PDF provides rainfall data during 3,000 years for historical climate conditions and during 5,400 years for future climate conditions. The rainfall with a 50-year return period under future climate conditions exceeded the rainfall with a 100-year return period under historical climate conditions. Consequently, in future climate conditions, the magnitude of rainfall increased at the same return period and, the return period decreased at the same magnitude of rainfall. In this study, by using the d4PDF data, it was possible to analyze the change in extreme magnitude of rainfall.

Average Length and Bounds on the Busy Period for a k-out-of-n : G System with Non-identical Components

  • Jung, Kyung-Hee
    • 한국경영과학회지
    • /
    • 제17권2호
    • /
    • pp.123-130
    • /
    • 1992
  • The model of k-out-of n : G repairable system with identical components is extended to a repairable system with n different components. The objective is to analytically derive the mean time of the busy period for a k-out-of-n : G system with unrestricted repair. Then, the lower and upper bounds on the average time of the busy period of the n-component system with restricted repair are also shown.

  • PDF

Tall fescue 품종의 환경적응성 II. 가을철 건물생산의 품종간 차이와 수량구성요소 (Environmental Adaptation of Tall Fescue Varieties in Mountainous Pastures II. Varieties differences of dry matter production and yield components in growth period of Autumn)

  • 이주삼;한성윤;조익환
    • 한국초지조사료학회지
    • /
    • 제13권2호
    • /
    • pp.78-85
    • /
    • 1993
  • This experiment was carried out to select for the varieties with high environmental adaptability in mountainous pastures of Taekwalyong area, and the evaluation was based on the data of varietal differences of dry matter production and yield components in Tall fescue cutting at various developmental stages in growth period of autumn. The results were summarized as follows; 1. The varieties with high number of tillers per plant(NT) showed a high dry weight of plant(DW) in all autumn cuttings. These varieties(Barce1 and Fuego) may be more adaptable to mountainous pastures of Taekwalyon area than other varieties. 2. The number of tillers per plant(NT) was significantly positive correlated with dry weight of plant (DW), but dry weight of tiller(WT) was not significantly correlated with dry weight of plant(DW) in all autumn cuttings. 3. The multiple regression equations of autumn cutting stages with mean dry weight of plant(DW) and number of tillers per plant(NT) can be used to estimate the cutting time to obtain maximum mean dry weight of plant(DW) and the highest number of tillers per plant(NT). The maximum mean dry weight of plant(DW) and the highest number of tillers per plant(NT) was estimated at the time of 21 Oct. and 26 Oct, respectively. 4. Dead leaves tended to increase greatly after the 2nd cutting(l4 Oct.) in growth period of autumn. 5. The number of tillers per plant(NT) was an important yield component before tiller density achieved equilibrium, but dry weight of tiller(WT, including dead leaves) was of most significant as a yield determinant after maximum tiller density reached in growth period of autumn.

  • PDF

Outcome of Pallidal Deep Brain Stimulation in Meige Syndrome

  • Ghang, Ju-Young;Lee, Myung-Ki;Jun, Sung-Man;Ghang, Chang-Ghu
    • Journal of Korean Neurosurgical Society
    • /
    • 제48권2호
    • /
    • pp.134-138
    • /
    • 2010
  • Objective : Meige syndrome is the combination of blepharospasm and oromandibular dystonia. We assessed the surgical results of bilateral globus pallidus internus (GPi) deep brain stimulation (DBS) in patients with medically refractory Meige syndrome. Methods : Eleven patients were retrospectively analyzed with follow-ups of more than 12 months. The mean follow-up period was $23.1{\pm}6.4$ months. The mean age at time of surgery was $58.0{\pm}7.8$ years. The mean duration of symptoms was $8.7 {\pm}7.6$ years. DBS electrodes were placed under local anesthesia using microelectrode recording and stimulation. After $2.4{\pm}1.3$ days of trial tests, the stimulation device was implanted under general anesthesia. Patients were evaluated using the Burke-Fahn-Marsden Dystonia Rating Scale (BFMDRS). Results : BFMDRS total movement scores improved by 59.8%, 63.5%, 74.1%, 74.5%, and 85.5% during the immediate postoperative period of test stimulation, 3, 6, 12, and 24 months (n = 5) after surgery, respectively. The BFMDRS total movement scores were reduced gradually and the results reached statistical significance in the postoperative period (test period, p < 0.001; 3 months, p < 0.001; 6 months, p = 0.003; 12 months, p < 0.001; 24 months, p = 0.042). There was no statistical difference between 12 months and 24 months. BFM subscores improved by 63.3% for the eyes, 80.9% for the mouth, 68.4% for speech/swallowing, and 87.9% for the neck at 12 months after surgery. The adverse effects were insignificant. Conclusion : The bilateral GPi-DBS can be effective for the treatment of intractable Meige syndrome without significant side effects.