• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2000년도 춘계학술대회논문집
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• pp.658-663
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• 2000

Slopping phenomena deteriorate the productivity and the stability of operation in oxygen converter process. To predict and prevent that, it needs reliable perception of the internal state of the oxygen converter chamber. Equipment was developed to measure the dynamic and static behavior of the oxygen-blowing lance 3-dimensionally and the measured signal is analyzed in relation to slopping phenomena. It was found that the behavior of the lance is strongly correlated to the change of slag foam height and the instability of molten steel behavior. So slopping phenomena can be predicted by simultaneously analyzing the measured behavior of the lance and the control factors such as the flow rate of oxygen and the height of lance.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2000년도 하계학술대회 논문집 D
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• pp.2545-2547
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• 2000

In this paper, a hybrid fuzzy controller using genetic algorithm based on parameter estimation mode to obtain optimal control parameter is presented. First, The control input for the system in the HFC is a convex combination of the FLC's output in transient state and PID's output in steady state by a fuzzy variable, namely, membership function of weighting coefficient. Second, genetic algorithms is presented to automatically improve the performance of hybrid fuzzy controller utilizing the conventional methods for finding PID parameters and estimation mode of scaling factor. The algorithms estimates automatically the optimal values of scaling factors, PID parameters and membership function parameters of fuzzy control rules according to the rate of change and limitation condition of control input. Computer simulations are conducted to evaluate the performance of proposed hybrid fuzzy controller. ITAE, overshoot and rising time are used as a performance index of controller.

• 대한방사성의약품학회지
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• 제6권2호
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• pp.116-130
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• 2020

The aging society is globally one of biggest issue because it is related with various degenerative brain disease such as dementia, Parkinson's disease, Alzheimer's disease, multiple sclerosis, and cerebrovascular disease. These diseases are characterized by misfolded-protein aggregation; another pathological trait is "neuroinflammation". In physiological state, the resting microglia cells are activated and it removes abnormal synapses and cell membrane debris to maintain the homeostasis. In pathological state, however, microglia undergo morphological change form 'resting' to 'activated amoeboid phenotype' and the microglia cells are accumulated by neuronal damage, the inflammatory reactions induced nerve metamorphosis with a variety of neurotoxic factors including cytokines, chemokines, and reactive oxygen species. Thus, the activated microglia cell with various receptors (TSPO, COX, CR, P2XR, etc.) was perceived as important biomarkers for imaging the inflammatory progression. In this review, we would like to introduce the current status of the development of radiotracers that can image activated microglia.

• 성인간호학회지
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• 제15권1호
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• pp.126-136
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• 2003

Purpose: The purpose of this study was to analyze related factors for major nursing diagnoses used in caring for institutionalized elders. Method: This study was a descriptive study. The participants were 92 residents in a long-term care facility in Wonju, selected by convenience sampling. The instrument was a checklist designed on the basis of the related factors suggested by NANDA (1997) and a literature review. Data was collected by chart review, observation, and interviews with the participants. Data was analyzed using descriptive statistics with the SPSS WIN program. Result: The most frequent nursing diagnosis was 'risk for injury', 'self-esteem disturbance', 'activity intolerance', 'impaired phyical mobility', and 'powerlessness'. The most frequent component for related factors for the five component for each nursing diagnosis was the physical component, followed by the social component. Common related factors for the nursing diagnoses were 'pain', 'change of emotional state/disorder', 'cognitive disorder', 'change of physical structure and function', and 'physical impairment', and 'immobility'. Conclusion: The results of this study can contribute to the development of appropriate nursing intervention programs for elders (eg. 'Injury Prevention Programs', 'Self-esteem Improvement Programs' etc.). Clinical guidelines that gerontological nurses can use to accurately assess health problems and select appropriate nursing interventions may be developed.

• 한국자동차공학회논문집
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• 제21권1호
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• pp.121-127
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• 2013

In this study, suspension geometry is controlled to improve vehicle handling performance. The toe and camber of the rear suspension is controlled independently by using a double knuckle structure designed to enhance the vehicle cornering stability. Camber and toe changes in the rear wheel during high speed turning maneuver are important factors that influence the vehicle stability. Toe in the rear outer wheel plays a dominant role in cornering. A control algorithm for the camber and the toe angle input is developed to carry out the control simulation of the vehicle such as single lane change, the steady state cornering, the double lane change and the step steering simulation. Effects of the camber and toe angle control are analyzed from the computer simulations. A double lane change simulation revealed that the suspension mechanism with variable camber angle and variable toe angle decreases the peak body slip angle and peak yaw rate, 50% and 10%, respectively.

• 대한기계학회논문집B
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• 제24권9호
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• pp.1166-1174
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• 2000

This work presents a two-dimensional quasi-steady state model to study the fluid flow and heat transfer in high-power density welding process of thin AISI-304 stainless steel plates. The enthalpy method and the finite volume method were used for a numerical analysis of the mushy region phase change as well as the heat flow at the weld pool and the heat-affected zone. The results show that the mushy region distributed around the weld pool becomes wider downstream and the surface heat losses by convection and radiation can be significant factors in welding process especially when a welding speed is relatively low.

• 한국소음진동공학회논문집
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• 제21권1호
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• pp.41-46
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• 2011

In this paper, we experimentally investigate factors that decrease in noise of a industrial take-out robot at driving state. For this, we analyse change in the noise of the take-out robot with gear machining accuracy and clearance. In order to calculate the noise related to gear machining accuracy that is based upon the Japanese Industrial Standard(JIS), we equally increase motor speed from 0 rpm to 1250 rpm. In addition, to investigate influence of clearance on noise, we evenly change clearance from 0.5 mm to 1.2 mm. These experiments show that clearance is more effective factor than gear machining accuracy to reduce the noise of the take-out robot.

• 상하수도학회지
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• 제12권4호
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• pp.59-69
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• 1998

Biological treatment systems generally can be divided into two main classes of a suspended sludge process and attached one like a fluidized bed reactor. These process are considered to bring remarkable change in species composition of microorganisms, due to difference of a state of biofilm, a concentration and diffusion velocity of dissolved oxygen, a concentration and diffusion velocity of substance or poisonous matter. The change of species composition bring different treatment result for influence factors like F/M ratio, DO concentration, pH or poisonous matter. This study is to investigate the reaction characteristics of both microorganisms, namely, a suspended sludge and attached sludge, through the changes of pH, temperature and substance concentration.

• Nuclear Engineering and Technology
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• 제34권2호
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• pp.176-185
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• 2002

A 4-bundle shift refuelling method of CANDU6 F/H (Fuel Handling) System is analyzed to assess the operational flexibility and capacity of F/H system. The current 8-bundle shift refuelling scheme requires to refuel eight fuel bundles from a single fuel channel, and to refuel 14 fuel channels in a week on average assuming that the reactor is in a steady state. The analysis showed that the 4-bundle shift refuelling method increases F/M (Fuelling Machine) duty cycle and operator load. However, the fuellin’g method change from the 8- to 4-bundle shift refuelling ill not require additional team of operators. A marginal increase in the maintenance cost may be resulted in by the change of fuelling method and the increase of fatigue usage factors requires some components to be replaced during the FM lifetime.

• 여성건강간호학회지
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• 제6권4호
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• pp.619-631
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• 2000

The purpose of this research is to understand the levels of crisis and quality of life and the relationship between them. Data was collected from questionnaires completed by 384 middle-aged women between 40 and 59 years old. The sense of crisis was measured by a scale which was developed by Kim(1988) and modified by Oh(1999). The quality of life was measured by the scale which was developed by Noh(1988). The data was analyzed using the SPSS (Statistical Package for the Social Sciences) program and included: descriptive statistics, Pearson correlation, and stepwise regression. The results of this study were as follows: 1) In the sense of crisis scale, 'experiencing emptiness and powerlessness through my friends is the highest item($3.56{\pm}1.06$). 'Meaninglessness in daily living' factor's score is $3.16{\pm}0.76$ and another factor, 'concept of my life thus far' score is $2.89{\pm}0.74$. Then the former is higher than the latter. 2) In the quality of life, 'eat well now' is the highest item($3.60{\pm}0.93$). 'self-esteem' is the highest factor($3.37{\pm}0.62$) and 'emotional state' is the lowest factor($2.89{\pm}0.31$). 3) According to the correlation between factors of crisis and quality of life, there was a significant negative correlation between two factors of crisis and five factors of quality of life except emotional state. 4) According to linear regression, two factors of the sense of crisis showed the explanatory power of the quality of life with 31.6%. On the basis of above findings, the following is suggested; Crisis is not precipitated by special events and new accidents, but the normal emotional change phenomena process in the human life cycle. As a result, we should develop the nursing programs and education programs about crisis intervention for middle-aged women's health.