• Journal of Ecology and Environment
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• 제48권2호
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• pp.196-206
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• 2024

Background: Most of the biomass equations were developed using sample trees collected mainly from pan-tropical and tropical regions that may over- or underestimate biomass. Site-specific models would improve the accuracy of the biomass estimates and enhance the country's measurement, reporting, and verification activities. The aim of the study is to develop site-specific biomass estimation models and validate and evaluate the existing generic models developed for pan-tropical forest and newly developed allometric models. Total of 140 trees was harvested from each diameter class biomass model development. Data was analyzed using SAS procedures. All relevant statistical tests (normality, multicollinearity, and heteroscedasticity) were performed. Data was transformed to logarithmic functions and multiple linear regression techniques were used to develop model to estimate aboveground biomass (AGB). The root mean square error (RMSE) was used for measuring model bias, precision, and accuracy. The coefficient of determination (R² and adjusted [adj]-R²), the Akaike Information Criterion (AIC) and the Schwarz Bayesian information Criterion was employed to select most appropriate models. Results: For the general total AGB models, adj-R² ranged from 0.71 to 0.85, and model 9 with diameter at stump height at 10 cm (DSH₁₀), ρ and crown width (CW) as predictor variables, performed best according to RMSE and AIC. For the merchantable stem models, adj-R² varied from 0.73 to 0.82, and model 8) with combination of ρ, diameter at breast height and height (H), CW and DSH₁₀ as predictor variables, was best in terms of RMSE and AIC. The results showed that a best-fit model for above-ground biomass of tree components was developed. AGB_Stem = exp {-1.8296 + 0.4814 natural logarithm (Ln) (ρD²H) + 0.1751 Ln (CW) + 0.4059 Ln (DSH₃₀)} AGB_Branch = exp {-131.6 + 15.0013 Ln (ρD²H) + 13.176 Ln (CW) + 21.8506 Ln (DSH₃₀)} AGB_Foliage = exp {-0.9496 + 0.5282 Ln (DSH₃₀) + 2.3492 Ln (ρ) + 0.4286 Ln (CW)} AGB_Total = exp {-1.8245 + 1.4358 Ln (DSH₃₀) + 1.9921 Ln (ρ) + 0.6154 Ln (CW)} Conclusions: The results demonstrated that the development of local models derived from an appropriate sample of representative species can greatly improve the estimation of total AGB.

• 대한간호학회지
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• 제22권4호
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• pp.506-525
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• 1992

Older people, because of the psychological and physiological changes related to the aging process are more vulnerable to experiencing powerlessness than any other age group. This self destructive cycle of depression in older people related to the experience of continued and long term powerlessness can lead even to death. The purpose of this study was to measure powerlessness and resources to increase power in older people, and to measure the effectiveness of a psychological rehabilitation program for reducing powerlessness. The research methodology used was a two step process. In the first step, a survey was done of perceived powerlessness and power resources comparing four groups of elderly people ; those living at home, those in hospital, those living in nursing homes and those attending educational programs for the elderly. The total sample size was 236. In the second step, a psychological rehabilitation program was carried out, pre and post measurements were taken related to this program. The sample consisted of 29 residents in a nursing home. The results of the study are as follows : 1. Powerlessness was classified as cognitive, emotional, activity and learning. The lowest score for powerlessness was in the area of activity, that is the people in the sample felt more power concerning their activities. The highest score was in the area of cognition where they felt they had less power. 2. When the different groups of elderly were compared, it was found that the residents of the nursing home had the highest score on perceived powerlessness and the group who were living at home had the lowest score. 3. Among the general characteristics, the factors influencing the powerlessness score were age, sex, level of education, financial resources and health status. In the interaction effects among these factors, it was found that level of education and health status were factors influencing perceived powerlessness. The elderly with lower education and poorer health status had the higher scores for perceived powerlessness. 4. The power resources could be classified into the following areas : physical strength, emotional strength, positive self-image, energy, knowledge, motivation and belief system. Belief system was given the highest score among the power resources and energy, knowledge and motivation were given low scores. 5. The group participating in an educational program for the elderly had the highest score for power resources while the group made up of residents of a nursing home had the lowest score as well as the highest score for perceived powerlessness. 6. The factors influencing the power resource scores were sex, level of education, financial resources and health status. In the analysis of the interaction effect among the factors, it was found that sex, level of education and financial resources were the factors that influenced the power resource score, that is, women, those with a low level of education and those with poor financial resources reported a lower level of power resources. 7. There was a negative correlation between perceived powerlessness and power resources in the elderly in this study. Since power resources explainded 49% of the variance for powerlessness, it can be concluded that the power resources can be used to reduce powerlessness. 8. The psychological rehabilitation program was carried out with the nursing home residents over a period of five weeks. No statistically significant difference was found in the scores on powerlessness between the pre and post tests, but there was a slight decrease in the raw scores on the post test for emotional, activity and learning powerlessness. There was a statistically significant increase in the power resource scores for emotional strength, positive self-image, energy, knowledge and motivation in the post test as compared to the pre test. In conclusion, the study indicates that a psychological rehabilitation program for the elderly could be effective in increasing power resources and this in turn could lead to a decrease in perceived powerlessness.

• 인터넷정보학회논문지
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• 제25권1호
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• pp.99-107
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• 2024

경제성장과 산업 발전에 따라 반도체 제품부터 SMT 제품, 전기 배터리 제품에 이르기 까지 많은 전자통신 부품들의 제조과정에서 발생하는 철, 알루미늄, 플라스틱 등의 이물질로 인해 제품이 제대로 동작하지 않거나, 전기 배터리의 경우 화재를 발생하는 문제까지 심각한 문제로 이어질 가능성이 있다. 이러한 문제를 해결하기 위해 초음파나 X-ray를 이용한 비파괴 방법으로 제품 내부에 이물질이 있는지 판단하여 문제의 발생을 차단하고 있으나, X-ray 영상을 취득하여 이물질이 있는지 판정하는 데에도 여러 한계점이 존재한다. 특히. 크기가 작거나 밀도가 낮은 이물질들은 X-Ray장비로 촬영을 하여도 보이지 않는 문제점이 있고, 잡음 등으로 인해 이물들이 잘 안 보이는 경우가 있으며, 특히 높은 생산성을 가지기 위해서는 빠른 검사속도가 필요한데, 이 경우 X-ray 촬영시간이 짧아지게 되면 신호 대비 잡음비율(SNR)이 낮아지면서 이물 탐지 성능이 크게 저하되는 문제를 가진다. 따라서, 본 논문에서는 저화질로 인해 이물질을 탐지하기 어려운 한계를 극복하기 위한 5단계 방안을 제안한다. 첫번째로, Global 히스토그램 최적화를 통해 X-Ray영상의 대비를 향상시키고, 두 번째로 고주파 영역 신호의 구분력을 강화하기 위하여 Local contrast기법을 적용하며, 세 번째로 Edge 선명도 향상을 위해 Unsharp masking을 통해 경계선을 강화하여 객체가 잘 구분되도록 한다, 네 번째로, 잡음 제거 및 영상향상을 위해 Resdual Dense Block(RDB)의 초고해상화 방법을 제안하며, 마지막으로 Yolov5 알고리즘을 이용하여 이물질을 학습한 후 탐지한다. 본 연구에서 제안하는 방식을 이용하여 실험한 결과, 저밀도 영상 대비 정밀도 등의 평가기준에서 10%이상의 성능이 향상된다.