• Journal of the Korean Society of Safety
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• v.24 no.3
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• pp.71-78
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• 2009

During a learning process, a human being is assumed to experience knowledge-based behaviors, rule-based behaviors, and skill-based behaviors sequentially if Rasmussen was right. If any psycho-physiological symptom to those different levels can be obtained, it can be useful as a measure whether a human being is fully trained and has gotten a skill in his work. Therefore, this study aimed to draw relationships between human performance measures and psycho-physiological measures while committing a computer-simulated pointing task by utilizing the power spectrum technique of EEG data, especially with the ratio of relative beta-to-alpha band power. The result showed that, during correct responses, the ratio came to stabilize as all the performance data went stable. However, response time was not a simple linear function of task difficulty level only, but a joint function of task characteristics as well as behavior levels. Comparing relative band power ratios from errors and correct responses, activated states of one's brain could be explained, and characteristics of the task could understood. To tell that of pointing task, correlations around C3, C4, P3, P4 and 01, 02 area were significant and high in correct response cases whereas most correlation coefficients went down in error cases standing for imbalance of psycho-motor functions. Though task difficulty was the only one factor that could influence on relative band power ratio with statistical significance, it should be comprehended to mean a different way of expression indicating task characteristics since at least error-some situation could be explained with the help of relative band power ratio that absolute band power failed.

• Korean Journal of Construction Engineering and Management
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• v.5 no.5 s.21
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• pp.143-150
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• 2004

Nowaday, The tendency of complexity and extension of construction fields increase the need for efficient works managements like a construction management. Consequently, by the introduction of Decision-Making Theories, researches for improving construction field's efficiencies are actively performed. Fuzzy Analytical Hierarchy Process method is invented, so that describes a decision maker's ambiguous linguistic judgment with fuzzy numbers. but most of researches on Fuzzy-AHP use symmetric triangular fuzzy function for estimating each evaluation item with the consequence that exact judgments are impossible. those limits are caused by the point that employed fuzzy ranking methods can not support dissymmetric fuzzy numbers. In this research, we aims to overcome this problem with R.P.R(Relative Preference Ratio) method and suggest improved Fuzzy-AHP method which can use dissymmetric fuzzy triangular numbers.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2016.10a
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• pp.79-80
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• 2016

In this study, we measured the relative density and the compressive strength in order to select the appropriate W/ B for the ultra-high strength concrete development. If W/B is lowered than the W/B of highest relative density, it was confirmed that the strength is lowered. However, if water is increased than the W/B of highest relative density, the relative density is decreased compressive strength was similar. The selection of the W/B of the lower than the highest relative density is not appropriate. Appropriate W/B is selected to be more than the maximum relative density of W/B.

• Journal of Korean Academy of Nursing
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• v.30 no.4
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• pp.948-955
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• 2000

This study was done to compare the difference of obesity index(waist-hip ratio, body fat, body mass index, relative body weight), blood pressure and serum lipids in abdominal obesity and non abdominal in both men and women. Abdominal and non abdominal obesity was divided into waist-hip ratio above 0.85 in women and 0.95 in men. The subjects were 412 adults (age range 40-59), who had regular health examinations between 1996 to 1997 at the S-Hospital in Seoul. The data were analyzed using ANCOVA (for adjusted for age) and Pearson correlation coefficient. The results were as follows: 1. 39.9% of men and 42.5% of women had abdominal obesity. The average age group of abdominal obesity was 50.8 which is older than the non abdominal obesity group(48.0). 2. After they were adjusted for age, the group of men who have abdominal obesity had higher levels in body fat, body mass index, relative body weight, blood pressure, total cholesterol, LDL- cholesterol and triglyceride than the group of non abdominal obesity group. The group of women with abdominal obesity had higer levels in body fat, body mass index, relative body weight , blood pressure and triglyceride than the group of non abdominal obesity. 3. In the group of non abdominal obesity, the waist-hip ratio was significantly correlated to body fat, body mass index, relative body weight, blood pressure and serum lipids the group of abdominal obesity in men and women.

• Current Research on Agriculture and Life Sciences
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• v.3
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• pp.99-104
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• 1985

This research was carried out study the effect of several relative humidities on the cracking of kernels of chestnuts. The moisture contents of total kernel increased at the higher humidity over 88% relative humidity. but the moisture contents of inner layer was decreased at low relative humidity below 76 %. The starch contents of kernel decreased, but free stgars increased during the total period of storage. The tannin contents increased during total of storage, and the tannin contents of out layer was higher than inner layer because of tannin transfer from astringent shell. As we considered the sprouting ratio, the rotting ratio and the cracking ratio, the optimal relative humidity of chestnut storage was proved 88% relative humidity.

• Journal of the Korean Ceramic Society
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• v.31 no.6
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• pp.637-642
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• 1994

Using SHS(Self-propagating High-temperature Synthesis) method, the optimum synthetic condition of titanium carbonitride was established by controlling the parameters such as relative density of mixture (Ti+C), nitrogen pressure, additive amounts of titanium hydride(TiH1.924) and protecting heat loss. Under 1 atm nitrogen pressure, nitridation ratio with changing relative density of the sample compacts has a maximum (87.2%) at about 55%, and in the case of enveloping the pellet with a quartz tube, the highest nitridation ratio of 90% was obtained at about 68%. At relative density of 55%, nitridation ratio with the nitrogen pressure has a miximum (87.3%) at 7 atm. As the amounts of additive titanium hydride increased, nitridation ratio decreased at below 7 atm nitrogen pressure and, increased at above this pressure until percent of addition percent reached 15 wt% and decreased abruptly upon futher increases in titanium hydride. In the synthesis of TiCxNy by combustion reaction, heat transfer from combustion zone to preheating zone and nitrogen gas penetration into the compact were found to be important factors affecting the TiCxNy formation. It was difficult to obtain high nitridation ratio when the conbustion temperature was either too high or too low, and it seems that the retention of high temperature after a combustion wave sweeped through the reactant mixture pellet is critical to obtain a satisfactory nitridation ratio.

• Journal of the Korea Concrete Institute
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• v.13 no.3
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• pp.237-243
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• 2001

The prediction model is proposed to estimate the variation of compressive strength of fly ash concrete with aging. After analyzing the experimental result with the model, the regression results are presented according to fly ash replacement content and water-cement ratio. Based on the regression results, the influence of fly ash replacement content and water-cement ratio on apparent activation energy was investigated. According to the analysis, the model provides a good estimate of compressive strength development of fly ash concrete with aging. As the fly ash replacement content increases, the limiting relative compressive strength and initial apparent activation energy become greater. The concrete with water-cement ratio smaller than 0.40 shows that the limiting relative compressive strength and apparent activation energy are nearly constant according to water-cement ratio. But, the concrete with water-cement ratio greater than 0.40 has the increasing limiting relative compressive strength and apparent activation energy with increasing water-cement ratio.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.22 no.4
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• pp.855-869
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• 1997

In this paper, we proposed two kids of dynamic priority control mechanisms controlling the cell service ratio in order to improve the QOS(Quality of Service). We also analyse theoretically the characteristics of cell loss probability and mean cell delay time by applying the proposed priority control mechanisms to ATM switch with output buffer. The proposed priority control mechanisms have the same principles of storing cells into buffer but the different principles of serving cells from buffer. The one is the control mechanism controlling the cell service ratio according to the relative cell occupancy ratio of buffer, the other is the control mechanism controlling the cell service ratio according to both the relative cell occupancy ratio of buffer and the average arrival rate. The two service classes of our concern are the delay sensitive class and the loss sensitive class. The analytical results show that the proposed control mechanisms are able to improve the QOS, the characteristics of cell loss probability and mean cell delay time, by selecting properly the relative cell occupancy ratio of buffer and the average arrival rate. conventional DLB algorithm does not support synchronous cells, but the proposed algorithm gives higher priority to synchronous cells. To reduce synchronous cell loss rate, the synchronous cell detector is used in the proposed algorithm. Synchronous cell detector detects synchronous cells, and passes them cells to the 2nd Leaky-Bucket. So it is similar to give higher priority to synchronous cells. In this paper, the proposed algorithm used audio/video traffic modeled by On/Off and Two-state MMPP, and simulated by SLAM II package. As simulation results, the proposed algorithm gets lower synchronous cell loss rate than the conventional DLB algorithms. The improved DLB algorithm for multimedia synchronization can be extended to any other cells which require higher priority.

• Journal of Navigation and Port Research
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• v.34 no.2
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• pp.111-115
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• 2010

In this paper, the electromagnetic (EM) wave absorbers using TiO2 as a dielectric material with chlorinated polyethylene (CPE) were investigated in W-band radio frequencies. We compared the relative permittivity with reflectionless curve and the absorption properties of samples containing 40 wt.%, 50 wt.%, 60 wt.%, 70 wt.%, and 80 wt.% TiO2. It is possible to realize a complex relative permittivity satisfying the reflectionless condition by choosing composition ratio of TiO2. The optimized composition ratio of TiO2 for the maximum absorption property is about 70 wt.%. As a result, we have confirmed the realization of an EM wave absorber with a high absorption property in W-band radio frequencies.

• Health Policy and Management
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• v.11 no.2
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• pp.58-84
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• 2001

This study was conducted to explore the relationship between the efficiency and its organizational determinants of tile Community Mental Health Centers(CMHCs). Data are obtained from 81 personnel of 27 CMHCs from Sept. to Oct. in 1999(19 in Kyunggi province, 7 in Seoul City and 1 in Chunchon, Kangwon province). Major findings of this study are as follows. 1. DEA is a mathematical programming technique that optimizes the relative efficiency ratio of inputs over outputs for each decision-making unit(DMU). It produces a summary scalar efficiency ratio for each DMU of CMHCs. It assessed multiple inputs and multiple outputs simultaneously, and compared to specific peer group of CMHCs. 2. Organizational determinants of DEA efficiency of CMHCs we proved as advertisement(＋), location of CMHCs(in public facility)(＋), area of facility(＋), period of operation(＋), job satisfaction(＋), clarity of work-role(vague), cohesion(－), rate of certified personnel(＋), number of referral(＋), and voluntary service time(－).