• Title/Summary/Keyword: Stress indices

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Nutritional Efficiency in Antheraea mylitta D. during Food Deprivation

  • Rath, S.S.;Sinha, B.R.R.P.;Thangavelu, K.
    • International Journal of Industrial Entomology and Biomaterials
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    • v.9 no.1
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    • pp.111-115
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    • 2004
  • Nutrition plays an important role in maintaining the larval health, cocoon quality and reproductive potential in Antheraea mylitta D. Nutritional efficiency greatly influenced if food is not adequate and of quality. A. mylitta silkworms were subjected to food deprivation for the period of 0 hr to 12 hrs /day to assess its effect on various nutritional parameters and indices, and its manifestation at different levels. Food ingesta, digesta, gain in body weight declined significantly at each level of deprivation, so also food utilization efficiency like consumption index (CI), growth rate (GR), approximate digestibility (AD), and efficiency of conversion of ingested food (ECI). This stress leads to decline in mean daily food ingesta by 16.73% to 39.76% and digesta by 28.98% to 54.01 % following a significant reduction in average daily body weight gain (27.68% to 55.09%). Food deprivation a1so caused significant loss in the silk gland weight, cocoon and shell weight (14.37% to 53.69%), lowered the fecundity (35.86 % to 83.59%) and in number of eggs laid per gram body weight, but simultaneously the number of non-chorionated eggs increased significantly.

Analysis of Spring Drought Using NOAA/AVHRR NDVI for North Korea (NOAA/AVHRR NDVI를 이용한 북한지역 봄 가뭄 분석)

  • Jang, Min-Won;Yoo, Seung-Hwan;Choi, Jin-Yong
    • Journal of The Korean Society of Agricultural Engineers
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    • v.49 no.6
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    • pp.21-33
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    • 2007
  • Different vegetation indices from satellite images have been used for monitoring drought damages, and this study aimed to develop a drought index using NOAA/AVHRR NDVI(Normalized Difference Vegetation Index) and to analyze the temporal and spatial distribution of spring drought severity in North Korea from 1998 to 2001. A new drought index, DevNDVI(Deviation of NDVI), was defined as the difference between a monthly NDVI and average monthly NDVI at the same cover area, and the DevNDVI images at all years except for 2001 demonstrated the drought-damaged areas referred from various domestic and foreign publications. The vegetation of 2001 showed high vitality despite the least amount of rainfall among the target years, and the reason was investigated that higher temperature above normal average would shift the growing stages of plants ahead. Therefore, complementary methods like plant growth models or ground survey data should be adopted in order to evaluate drought-induced plant stress using satellite-based NDVI and to make up far the distortion induced by other environments than lack of precipitation.

A posteriori error estimator for hierarchical models for elastic bodies with thin domain

  • Cho, Jin-Rae
    • Structural Engineering and Mechanics
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    • v.8 no.5
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    • pp.513-529
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    • 1999
  • A concept of hierarchical modeling, the newest modeling technology, has been introduced in early 1990's. This new technology has a great potential to advance the capabilities of current computational mechanics. A first step to implement this concept is to construct hierarchical models, a family of mathematical models sequentially connected by a key parameter of the problem under consideration and have different levels in modeling accuracy, and to investigate characteristics in their numerical simulation aspects. Among representative model problems to explore this concept are elastic structures such as beam-, arch-, plate- and shell-like structures because the mechanical behavior through the thickness can be approximated with sequential accuracy by varying the order of thickness polynomials in the displacement or stress fields. But, in the numerical, analysis of hierarchical models, two kinds of errors prevail, the modeling error and the numerical approximation error. To ensure numerical simulation quality, an accurate estimation of these two errors is definitely essential. Here, a local a posteriori error estimator for elastic structures with thin domain such as plate- and shell-like structures is derived using the element residuals and the flux balancing technique. This method guarantees upper bounds for the global error, and also provides accurate local error indicators for two types of errors, in the energy norm. Compared to the classical error estimators using the flux averaging technique, this shows considerably reliable and accurate effectivity indices. To illustrate the theoretical results and to verify the validity of the proposed error estimator, representative numerical examples are provided.

A Physioclimatic Study on the Thermal Sensation in Korea (한국의 열감분포에 관한 생리 기후학적 연구 - 신유효온도를 중심으로 -)

  • 강철성
    • Journal of the Korean Geographical Society
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    • v.32 no.2
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    • pp.129-140
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    • 1997
  • The purpose of this paper is to analyze thermal sensation which is measured bv human physioclimatic reactions in Korea. Human physiological reactions to temperature and relative humidity are analyzed to produce a nomogram from which average human reactions to the climatic factors can be deduced. Thermal - indices for each regular stations in both South (1961-1990) and North Korea(1973-1994) are calculated based on monthly meteorological data. A generalized annual physioclimatic maps for each Annual Cumulative Thermal Index for the 52 stations are constructed to show how men tend to feel in various areas. Resuts of this study can be applied for evaluation of thermal environment in our daily activities, and for searching relevant sports training-sites.

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Emergy evaluation perspectives on the natural environment and economy of Seoul

  • Kang, Dae-Seok
    • Environmental Sciences Bulletin of The Korean Environmental Sciences Society
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    • v.10 no.S_1
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    • pp.1-10
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    • 2001
  • An emergy evaluation of the natural environment ant economy of Seoul revealed that Seoul used 1.27 E23 sej/yr of emergy in 1997. The emergy input from the Han River accounted for most of the renewable emergy sources. Emergy imported from foreign countries and other parts of Korea accounted for 97% of the total emergy use in Seoul in 1997, revealing that the economy of Seoul is more dependent on outside emergy sources than for the entire Korean economy. The emergy use per unit area(2.09 E14 sej/$m^2$/yr) was higher than that for the entire country or Pusan, whereas the emergy use per capita(1.22 E16 sej/person/yr) was lower than that for the entire country or Pusan. These results reflect the overcrowded conditions in Seoul where about one fourth of the Korean population now live. They also seem to indicate a lower living standard in Seoul than the average in Korea. The quality of living in Seoul could also be judged by a high environmental loading ratio and a low sustainability index. All there indices suggest that people in Seoul live under a higher environmental stress than the average person in Korea.

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The Structural Equation Model of Burnout of the Critical Care Nurses Based on the Job Demand-Resource Model (직무요구-자원 모델에 기반을 둔 중환자실 간호사의 소진 구조모형)

  • Park, Ok Kyoung;Son, Myeong Hee;Park, Mi Youn;Baek, Eun Sun;Kim, Phill Ja
    • Journal of Korean Clinical Nursing Research
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    • v.22 no.1
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    • pp.88-98
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    • 2016
  • Purpose: The purpose of this study was to construct and test a structural equation model of burnout of the critical care nurses based on the job demand-resource model. Methods: A structured questionnaire was completed by 414 critical care nurses. The relationships between concepts of job stress, empathic ability, resilience, job satisfaction, compassion fatigue and burnout were analyzed. Using SPSS WIN 22.0 and AMOS 22.0 programs, the direct and indirect effects of factors affecting burnout among critical care nurses were calculated and modelled. Results: The modified model was yielded as follows: Chi-square= 216.59, GFI= .93, AGFI= .89, NFI= .90, CFI= .93, RMSEA= .07, SRMR= .06 and showed good fit indices. Job satisfaction and compassion fatigue had mediation effects between other three exogenous variables and burnout. Conclusion: The major findings of this study indicate that it is important to develop a support program for critical care nurse in order to improve their job satisfaction and ameliorate their compassion fatigue.

A Study of Engineering Properties and Deformation Behavior of Weathered Rock Mass (풍화 암반의 공학적 특성 및 변형거동에 관한 연구)

  • 강추원;박현식;김수로
    • Explosives and Blasting
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    • v.22 no.2
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    • pp.33-43
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    • 2004
  • The six grades weathering system is normally used in weathered rock classification. In this study. fresh and weathered rock block of grade I to V were sampled in Jang-soo ana but samples of the grade VI was omitted from this study. The variation quantities of chemical weathering indices with weathering degree are smaller than those of physical and mechanical properties. Increase of Weathering degree is well indicated by physical and mechanical properties such as strength, hardness, ultrasonic velocity and slake durability result. Especially, absorption and porosity ratio is a good indicator. As weathering proceeds. a number of the cracks affect the rock deformation. Therefore, stress-strain curves of weathered rocks in unconfined state are quite different from ones of fresh rocks.

Reliability Analysis Modeling for LRFD Design of Bridge Abutments (LRFD 설계를 위한 교대의 신뢰성 해석 모델)

  • Eom, Jun-Sik
    • Journal of the Korean Geotechnical Society
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    • v.30 no.8
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    • pp.5-11
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    • 2014
  • The objective of this paper is to develop a rational reliability analysis procedure for the LRFD design provisions of bridge substructures. A bridge abutments is considered in this study. The reliability analysis is applied to determine the relationship between the major design parameters for bridge abutment and reliability index. The considered load components include dead load, vertical and horizontal earth pressure, earth surcharge, and vehicle live load. Several limit states are considered: foundation bearing capacity, sliding, and overturning. The analysis results show that the most important parameter in the reliability analysis is the effective stress friction angle of the soil. The reliability indices are calculated using Monte Carlo simulations for a selected bridge abutment. The results of the sensitivity analysis indicate that reliability index is most sensitive with regard to resistance factor and horizontal earth pressure factor.

Effects of formalin on haematology and blood chemistry in crucian carp (Carassius auratus) (포르말린 침지에 의한 붕어(Carassius auratus)의 혈액학 및 혈액화학치에 대한 영향)

  • Im, Chang-Won;Park, Se-Chang;Heo, Gang-Joon
    • Korean Journal of Veterinary Research
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    • v.46 no.3
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    • pp.249-254
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    • 2006
  • To determine the effects of exposure to formalin on the secondary stress indices, changes in haematology and blood chemistry were monitored in healthy crucian carps (Carassius auratus). Fishes were separately exposed in a concentration range of 125 to 500 ppm formalin for 60 min. After exposure, red blood cell (RBC) count and packed cell volume (PCV) were elevated in the 500 ppm formalin exposed group. However, mean corpuscular volume (MCV) and mean corpuscular haemoglobin (MCH) were decreased significantly in the 500 ppm formalin exposed group. Total protein, albumin, aspartate aminotransferase (AST), alanine aminotransferase (ALT), creatinine, total bilirubin, inorganic phosphorus (IP) and magnesium were significantly increased at a concentration of 500 ppm. Alkaline phosphatase (ALP) and glucose were increased at a concentration of 500 ppm, but this was not significant. Lactate dehydrogenase (LDH) and calcium were significantly decreased at concentrations of 250 and 500 ppm. AST, ALT, glucose and magnesium were significantly increased in the 250 ppm formalin exposed group. These results suggests that formalin exposure might cause some damage in the liver and kidney of crucian carp.

A Study on the Measurement of Heart Rate Variability using the Modified Laplacian Electrodes (수정된 라플라시안 센서를 이용한 심박변이도 측정에 관한 연구)

  • Lee, Chung-Keun;Shin, Hang-Sik;Kim, Hong-Rae;Lee, Jeong-Whan;Kim, Yong-Jun;Lee, Myoung-Ho
    • The Transactions of The Korean Institute of Electrical Engineers
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    • v.58 no.5
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    • pp.1050-1056
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    • 2009
  • Heart Rate Variability(HRV) is a parameter that represents monitoring variability of time intervals between R-peak in electrocardiography. HRV serves to various applications, such as indices of autonomic functions, prediction of cardiac sudden death, assessment of stress and emotional, etc. However, as measuring R-peak in ECG needs at least 3-electrodes, and it is inconvenient for end users. In this paper, we suggested the modified laplacian electrodes for measuring HRV at one-point, which are producted by MEMS fabrication and have the two circular electrodes on the pad. For optimal position and direction, we performed an experiment that compared with pearson correlation coefficient and the amplitude of signals, between standard lead II and proposed electrodes. We analyzed the HRV parameters, such as standard deviation of the NN interval(SDNN), high frequency(HF), low frequency(LF), LF/HF ratio. The result showed that the average correlation coefficient and amplitude are 0.967 and 0.685 mVpp at the position 2. The coeffiecient correlation between the standard HRV and proposed electrode-HRV is 0.999