• International Journal of Reliability and Applications
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• 제13권2호
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• pp.91-104
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• 2012

Sarhan and Kundu (2009) introduced a new distribution named as the generalized linear failure rate distribution. This distribution generalizes several well known distributions. The probability density function of the generalized linear failure rate distribution can be right skewed or unimodal and its hazard function can be increasing, decreasing or bathtub shaped. This distribution can be used quite effectively to analyze lifetime data in place of linear failure rate, generalized exponential and generalized Rayleigh distributions. In this paper, we apply the simulated annealing algorithm to obtain the maximum likelihood point estimates of the parameters of the generalized linear failure rate distribution. Simulated annealing algorithm can not only find the global optimum; it is also less likely to fail because it is a very robust algorithm. The estimators obtained using simulated annealing algorithm have been compared with the corresponding traditional maximum likelihood estimators for their risks.

• 약학회지
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• 제22권4호
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• pp.207-214
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• 1978

Influence of Akebiae Lignum on the renal function of the dog was observed with water-extract, utilizing clearance technique. Akebiae Lignum water-extract (AWE) given intravenously in does of 3.0mg/kg and 30.0mg/kg elicited a marked antidiuretic effect and produced a distinguished decrease of glomerular filtration rate and renal plasma flow as reduction of sodium and potassium excretion in urine, positive free water clearance and osmolar clearance. AWE infused into a renal artery in doses of 0.03mg/kg/min and 0.1mg/kg/min exhibited identical results to the intravenous action confined only to the infused kidney. These results suggest that AWE elicits antidiuresis in the dog by decreasing glomerulor filtration and renal plasma flow, which are caused by the constriction of vas afferens in the glomeruli.

• Bulletin of the Korean Chemical Society
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• 제16권3호
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• pp.238-243
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• 1995

A pulsed molecular beam source having short pulse duration (typically 70 ${\mu}s)$ and narrow velocity distribution (${\Delta}$v/v=8% for helium) has been costructed utilizing a commercial fuel injector. Beam characteristics of helium and ammonia seeded in helium expansions are accomplished by the use of an electron impact time-or-flight mass spectrometer. The comparisons between experimental data and theoretical calculations show that the proper beam speed is important to predict the evolution of stream temperature and valve shutter function. The decreasing tendency of pulse duration with increasing cluster size leads to the conclusion that the cluster beam property is described as a function of cluster mass and disinct cluster temperature.

• Journal of Yeungnam Medical Science
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• 제40권3호
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• pp.225-232
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• 2023

Cognitive dysfunction is relatively less considered a complication of hypertension. However, there is sufficient evidence to show that high blood pressure in middle age increases the risk of cognitive decline and dementia in old age. The greatest impact on cognitive function in those with hypertension is on executive or frontal lobe function, similar to the area most damaged in vascular dementia. Possible cognitive disorders associated with hypertension are vascular dementia, Alzheimer disease, and Lewy body dementia, listed in decreasing strength of association. The pathophysiology of cognitive dysfunction in individuals with hypertension includes brain atrophy, microinfarcts, microbleeds, neuronal loss, white matter lesions, network disruption, neurovascular unit damage, reduced cerebral blood flow, blood-brain barrier damage, enlarged perivascular damage, and proteinopathy. Antihypertensive drugs may reduce the risk of cognitive decline and dementia. Given the high prevalence of dementia and its impact on quality of life, treatment of hypertension to reduce cognitive decline may be a clinically relevant intervention.

• 한국콘텐츠학회논문지
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• 제9권5호
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• pp.91-98
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• 2009

최근 디지털카메라의 기술 개발은 빛이 부족한 상황에서도 사진용 플래시와 같은 장비를 사용하지 않고서 사진을 촬영할 수 있는 다양한 고감도 기능을 탑재하는 경향이다. 또한 다양한 고감도에 적용시킬 수 있는 디지털카메라의 노이즈감소기능도 동시에 개발되고 있다. 그러나 노이즈가 발생하기 쉬운 고감도 상황에서 디지털카메라의 노이즈감소기능은 노이즈를 감소시키는 동시에 이미지의 해상도도 감소시키는 경향을 보인다. 따라서 본 연구에서는 디지털카메라의 노이즈감소기능이 이미지 해상도에 미치는 영향을 실험을 통해 양적으로 수치화 하고자 한다. 실험은 해상도와 노이즈 타깃을 디지털카메라의 감도별로 촬영하고, 측정값을 분석한 결과 노이즈감소기능이 적용될 때 최대 15%까지 해상도가 감소하는 것을 확인할 수 있었다. 이와 같은 연구는 디지털카메라의 사용자에게는 노이즈감소기능의 정확한 활용을 가능하게 하며 제조사에게는 노이즈감소기능을 검증해 볼 수 있게 할 것이다.

• 한국재료학회지
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• 제21권9호
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• pp.491-496
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• 2011

Transparent conducting oxides (TCOs) used in the antireflection layer and current spreading layer of heterojunction solar cells should have excellent optical and electrical properties. Furthermore, TCOs need a high work function over 5.2 eV to prevent the effect of emitter band-bending caused by the difference in work function between emitter and TCOs. Sn-doped $In_2O_3$ (ITO) film is a highly promising material as a TCO due to its excellent optical and electrical properties. However, ITO films have a low work function of about 4.8 eV. This low work function of ITO films leads to deterioration of the conversion efficiency of solar cells. In this work, ITO films with various Zn contents of 0, 6.9, 12.7, 28.8, and 36.6 at.% were fabricated by a co-sputtering method using ITO and AZO targets at room temperature. The optical and electrical properties of Zn-doped ITO thin films were analyzed. Then, silicon heterojunction solar cells with these films were fabricated. The 12.7 at% Zn-doped ITO films show the highest hall mobility of 35.71 $cm^2$/Vsec. With increasing Zn content over 12.7, the hall mobility decreases. Although a small addition of Zn content increased the work function, further addition of Zn content over 12.7 at.% led to decreasing electrical properties because of the decrease in the carrier concentration and hall mobility. Silicon heterojunction solar cells with 12.7 at% Zn-doped ITO thin films showed the highest conversion efficiency of 15.8%.

• 대한간호학회지
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• 제51권3호
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• pp.294-304
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• 2021

Purpose: This study aimed to investigate objectively measured physical activity (PA) in institutionalized older adults with mild cognitive impairment (MCI) and to elucidate the influence of autonomic nervous function, salivary cortisol, and PA on cognitive functions based on neurovisceral integration model. Methods: Overall cognitive function was evaluated using the mini-mental state examination (MMSE) and executive function was evaluated using semantic verbal fluency test and clock drawing test. Actigraph for PA, HRV and sAA for autonomous function, and the geriatric depression scale for depression were used. Saliva specimens were collected in the morning for sAA and cortisol. Results: Ninety-eight older adults from four regional geriatric hospitals participated in the study. They took 4,499 steps per day on average. They spent 753.93 minutes and 23.12 minutes on average in sedentary and moderate-to-vigorous activity, respectively. In the multiple regression analysis, lower salivary cortisol level (β = - .33, p = .041) and greater step counts (β = .37, p = .029) significantly improved MMSE score. Greater step count (β = .27, p = .016) also exerted a significant influence on verbal fluency, and greater sAA (β= .35, p = .026) was significantly associated with a better clock drawing test result. Conclusion: Salivary cortisol, sAA and physical activity were significantly associated with cognitive functions. To prevent older adults from developing dementia, strategies are needed to increase their overall PA amount by decreasing sedentary time and to decrease salivary cortisol for cognitive function, and to maintain their sympathetic nervous activity for executive function.

• Industrial Engineering and Management Systems
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• 제7권2호
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• pp.126-132
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• 2008

The bin packing problem (BPP) is an NP-Complete Problem. The problem can be described as there are $N=\{1,2,{\cdots},n\}$ which is a set of item indices and $L=\{s1,s2,{\cdots},sn\}$ be a set of item sizes sj, where $0<sj{\leq}1$, ${\forall}j{\in}N$. The objective is to minimize the number of bins used for packing items in N into a bin such that the total size of items in a bin does not exceed the bin capacity. Assume that the bins have capacity equal to one. In the past, many researchers put on effort to find the heuristic algorithms instead of solving the problem to optimality. Then, the quality of solution may be measured by the asymptotic worst-case ratio or the average-case ratio. The First Fit Decreasing (FFD) is one of the algorithms that its asymptotic worst-case ratio equals to 11/9. Many researchers prove the asymptotic worst-case ratio by using the weighting function and the proof is in a lengthy format. In this study, we found an easier way to prove that the asymptotic worst-case ratio of the First Fit Decreasing (FFD) is not more than 11/9. The proof comes from two ideas which are the occupied space in a bin is more than the size of the item and the occupied space in the optimal solution is less than occupied space in the FFD solution. The occupied space is later called the weighting function. The objective is to determine the maximum occupied space of the heuristics by using integer programming. The maximum value is the key to the asymptotic worst-case ratio.

• International Journal of Internet, Broadcasting and Communication
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• 제15권2호
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• pp.187-195
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• 2023

Sarcopenia is a phenomenon in which muscle function, including muscle strength, deteriorates as muscle mass decreases in the process of increasing age. The diagnosis of sarcopenia utilizes total muscle mass and limb muscle mass, and limb muscle mass is expressed as height squared, body weight, and BMI. Each divided value is used as an index, mainly less than 7.23 kg/m2 for men and less than 5.67 kg/m2 for women. Grip strength, standing up from a chair, and walking speed were mainly used as physical function factors, and grip strength less than 27 kg for men and less than 16 kg for women were used as indicators. The limb muscle mass showed a decreasing trend after peaking in the mid-20s in men, and maintaining a gradual peak in women from the mid-20s to the mid-40s, showing a more rapid decline in men. The rate of decrease in muscle mass and strength continues to increase after the age of 20, and muscle strength rapidly decreases after the age of 80. In Korean men, total muscle mass and limb muscle mass show a decreasing trend from the mid-30s, and a more markedly rapid decrease from the age of 60. For women, it remains constant from the age of 30 to the age of 50, then gradually decreases after the mid-50s, and shows a rather rapid decrease after the mid-70s, showing a more gradual decrease than that of men. Men show a sharp decrease from the mid-40s when limb muscle mass is divided by height squared, and women show a marked decrease after 70 years old when limb muscle mass is divided by height squared. Exercise for the prevention and treatment of sarcopenia results in an increase in protein assimilation hormone, an increase in antioxidant activity, a decrease in inflammation, an increase in muscle insulin sensitivity, and an increase in protein synthesis. Resistance exercise is basically used, and aerobic exercise and equilibrium A combination of exercises is effective. In addition, for a more efficient effect of sarcopenia through resistance exercise, it is necessary to supplement nutrition including protein.

• 보건의료산업학회지
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• 제9권3호
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• pp.201-210
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• 2015

Objectives : The purpose of this study was to identify the effect on cognitive function in elderly people above 65 years of age. Methods : The data were collected from June 1 to August 30 2014. Data were collected by questionnaire from 994 elderly people. The instruments for this study were ADL, IADL, depression, MMSE-DS. The data were analyzed using descriptive statistics, t-test, ANOVA, Pearson's correlation coefficients, multiple linear regression with the SPSS/WIN 18.0 program. Results : The significant factors influencing MMSE-DS were education(${\beta}=-0.314$, p<.001), IADL(${\beta}=0.196$, p<.001), age(${\beta}=-0.168$, p<.001), exercise time(${\beta}=0.089$, p=.004), economic conditions(${\beta}=0.086$, p=.007), depression(${\beta}=-0.084$, p=.001), income(${\beta}=-0.083$, p=.003), sleep time(${\beta}=-0.079$, p=.001), medical insurance(${\beta}=0.059$, p=.024) and leisure(${\beta}=0.057$, p=.039). Conclusions : Based on the study, subjects with cognitive impairment detected at an early stage it is necessary to intervene in consideration of the individual characteristics and to develop and apply the program that improve the living habits such as exercise and sleep, and decreasing depression.