• Structural Engineering and Mechanics
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• v.80 no.6
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• pp.645-655
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• 2021

Performance-based reliability analysis is a practical approach to investigate the seismic performance and stochastic nonlinear response of structures considering a random process. This is significant due to the uncertainties involved in every aspect of the analysis. Therefore, the present study aims to evaluate the performance-based reliability within a stochastic finite element (FE) framework for reinforced concrete (RC) shear walls that are considered as one of the most essential elements of structures. To accomplish this purpose, deterministic FE analyses are conducted for both squat and slender shear walls to validate numerical models through experimental results. The presented numerical analysis is performed by using the ABAQUS FE program. Afterwards, a random-effects investigation is carried out to consider the influence of different random variables on the lateral load-top displacement behavior of RC members. Using these results and through utilizing the Monte-Carlo simulation method, stochastic nonlinear analyses are also performed to generate random FE models based on input parameters and their probabilistic distributions. In order to evaluate the reliability of RC walls, failure probabilities and corresponding reliability indices are calculated at life safety and collapse prevention levels of performance as suggested by FEMA 356. Moreover, based on reliability indices, capacity reduction factors are determined subjected to shear for all specimens that are designed according to the ACI 318 Building Code. Obtained results show that the lateral load and the compressive strength of concrete have the highest effects on load-displacement responses compared to those of other random variables. It is also found that the probability of shear failure for the squat wall is slightly lower than that for slender walls. This implies that 𝛽 values are higher in a non-ductile mode of failure. Besides, the reliability of both squat and slender shear walls does not change significantly in the case of varying capacity reduction factors.

• Journal of Environmental Science International
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• v.26 no.7
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• pp.859-868
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• 2017

In this study, the reductive dechlorination of triclosan using zero-valent iron (ZVI, $Fe^0$) and modified zero-valent iron (i.e., acid-washed iron (Aw/Fe) and palladium-coated iron (Pd/Fe)) was experimentally investigated, and the reduction characteristics were evaluated by analyzing the reaction kinetics. Triclosan could be reductively decomposed using zero-valent iron. The degradation rates of triclosan were about 50% and 67% when $Fe^0$ and Aw/Fe were used as reductants, respectively, after 8 h of reaction. For the Pd/Fe system, the degradation rate was about 57% after 1 h of reaction. Thus, Pd/Fe exhibited remarkable performance in the reductive degradation of triclosan. Several dechlorinated intermediates were predicted by GC-MS spectrum, and 2-phenoxyphenol was detected as the by-product of the decomposition reaction of triclosan, indicating that reductive dechlorination occurred continuously. As the reaction proceeded, the pH of the solution increased steadily; the pH increase for the Pd/Fe system was smaller than that for the $Fe^0$ and Aw/Fe system. Further, zero-order, first-order, and second-order kinetic models were used to analyze the reaction kinetics. The first-order kinetic model was found to be the best with good correlation for the $Fe^0$ and Aw/Fe system. However, for the Pd/Fe system, the experimental data were evaluated to be well fitted to the second-order kinetic model. The reaction rate constants (k) were in the order of Pd/Fe > Aw/Fe > $Fe^0$, with the rate constant of Pd/Fe being much higher than that of the other two reductants.

• Journal of the Korea Society of Computer and Information
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• v.15 no.11
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• pp.1-9
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• 2010

As the process technology scales down, an interconnection has became a major performance constraint for multi-core processors. Recently, in order to mitigate the performance bottleneck of the interconnection for multi-core processors, a 3D integration technique has drawn quite attention. The 3D integrated multi-core processor has advantage for reducing global wire length, resulting in a performance improvement. However, it causes serious thermal problems due to increased power density. For this reason, to design efficient 3D multi-core processors, thermal-aware design techniques should be considered. In this paper, we analyze the temperature on the 3D multi-core processors in function unit level through various experiments. We also present temperature characteristics by varying application features, cooling characteristics, and frequency levels on 3D multi-core processors. According to our experimental results, following two rules should be obeyed for thermal-aware 3D processor design. First, to optimize the thermal profile of cores, the core with higher cooling efficiency should be clocked at a higher frequency. Second, to lower the temperature of cores, a workload with higher thermal impact should be assigned to the core with higher cooling efficiency.

• Journal of the Korean Solar Energy Society
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• v.32 no.6
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• pp.76-84
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• 2012

This study conducted experiments to measure air currents in an experimental building according to external conditions, types of induction ducts, and types of internal sockets by applying an external induction duct comprised of inducing openings and lines and induction units to the kitchen and bathroom vents at the rooftop of a super high-rise apartment building in order to help to improve the venting performance. The study also proposed the optimization of the external induction-style kitchen and bathroom vents capable of wind power generation. (1) As for air current distribution according to vent velocity changes, it increased the venting performance of the kitchen and bathroom by 1.0m/s at vent velocity of 2.0m/s or higher and allowed for wind power generation. (2)As for air current distribution according to external velocity changes, it increased the venting performance of the kitchen and bathroom by 1.2m/s at external velocity of 2.0m/s or higher and allowed for wind power generation. (3)As for air current distribution according to wind direction changes($0{\sim}180^{\circ}$), it was favorable for higher vent velocity when the angle between the external induction duct direction and prevailing wind direction was within ${\pm}30^{\circ}$. (4)As for air current distribution according to induction duct type, the[M1] type combining the inducing openings and lines with the induction units recorded the highest improvement effects in the kitchen and bathroom venting performance by increasing vent velocity by 46%. (5)As for air current distribution according to the changing types of internal sockets where the main ducts of the kitchen and bathroom are connected to the external induction ducts, the venturi tube type[Sv] increased vent velocity by 66% based on the smoothest external inflow.

• Journal of Korean Physical Therapy Science
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• v.15 no.2
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• pp.41-51
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• 2008

Background: The purpose of this study is to determine how the cognitive state of the elderly influences the activities of daily living(ADL) in order to increase their achievement capacity and their ability to exercise this capacity in daily life. The MMSE-K(Mini-Mental State Examination-Korean) was used to evaluate the daily activities and cognitive state of a group of subjects more than 65 years of age. The goal was to understand (1) How their achievement level in their daily activities changes according to the increase and decrease of their cognition points by analyzing and comparing their achievement points in the mental state examination, and (2) What variables influence that daily achievement level. Methods: The survey was conducted by a group of students from AnSan College who were trained for this method of data collection. The group surveyed 224 senior citizens older than 65 to determine their ADL performance. The subjects were selected from Silver Care Centers in the Gyounggi Province area including centers in Suwon, Anyang, Kwachun, and Sanbon City. The subjects were given enough information to fully understand the purpose of the study and the method by which it would be conducted. The survey method was a direct interview: which involved an interviewer reading the questionnaire to the subject and recording the answer. Result: The following results were calculated using SPSS WIN ver. 13.0: In the lower score of the MMSE-K regarding ADL performance (K-MBI) for activities such as individual hygiene, bathing activity, food activity, toilet management, going up stairs, getting dressed ad undressed, controlling stools and urination, walking, and chair/bed movement, most of the subjects responded that they could not perform these activities by themselves (p<.01). In the higher scores for the same activities, most response that they could perform the tasks by themselves (p<.01). In the results of the multiple regression analysis, there influence of the variables for ADL performance (K-MBI) and MMSE-K score was higher for females than males. Conclusion: This study evaluated the cognitive state of the elderly using the MMSE-K, which is the most convenient method, and examined how the cognitive state influences the achievement capacity of the daily lives with other variables. In conclusion, the higher the score on the MMSE-K, the more independent the elders are in the activities of daily living, especially among women more than men.

• Korean Journal of Poultry Science
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• v.25 no.3
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• pp.129-136
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• 1998

This experiment was carried out to investigate the effect of feeding system on performance in Korean Native Commercial Chicken. A total 864 birds produced from (Cornish ♂ X (Korean Native Chicken ♂ XRhode Island Red♀)♀ ] crossbreeds in National Livestock Research Institute, for 16 weeks. Feeding system of T1 and T$_2$ were same types from hatch to 8 weeks, starter diets(O~4 weeks, mash, ME 3,100kcal, CP 22.94%), grower diets(4~8 weeks, crumble, ME 3,100kcal, CP 19.31%). Nutrient content of finisher diets of T$_1$(pellet, ME 3,200kcal, CP 20.44%) was higher than T$_2$(mash, ME 3,100kcal, CP 14.88%) in order to improve meat quality for 8~16 weeks. Fertility and hatchability of Korean Native Commercial Chicken was 83.9% and 69.7%, respectively. Viabilities of T$_1$ and T$_2$ at 0, 4, 8, 12 and 16 weeks were 98.8%, 97.9%, 96.5% and 99.1%, 95. 8%, 92.8%, 90.3%, respectively. The viability of 0 to 8 weeks was not significantly in feed treatments, but 12 and 16 weeks was significantly T$_1$ higher than T$_2$(P<0.05). Body weights of T$_1$and T$_2$ at 4, 8, 12 and 16 weeks were 551g, 1,379g, 2,441g, 3,056g and 554g, 1,360g, 2,254g, 2,956g, respectively. The body weight of 0 to 8 weeks was not significantly feed treatments but 12 and 16 weeks was significantly T1 higher than T$_2$(P<0.05). Feed conversion of T$_1$ and T$_2$ to 4, 8,12 and 16 weeks were 1.91, 2.28, 3.34, 4.23 and 1.90, 2.28, 3.53, 4.46, respectively. The feed conversion of 0 to 8 weeks was not significantly feed treatments but 12 and 16 weeks was significantly T$_1$ lower than T$_2$(P<0.05). The ME intake 1 bird per 1 day of T$_1$ and T$_2$were 3S9kcal, 357kca1, respectively, not significantly feed treatments but CP intake were 24.8g, 20.3g, respectively. T$_2$ was lower than T$_1$(P$_1$ and T$_2$were 13,426kca1, 13,819Ykcal, respectively, not significantly feed treatments but CP requirement per kg body weight gain were 928g, 763g, respectively, T$_2$ was lower than T$_1$(P<0.05).

• Journal of the Korean Recycled Construction Resources Institute
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• v.9 no.4
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• pp.451-459
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• 2021

The purpose of this study is to evaluate the performance of a solidifying agent for recycling the fine powder separated from the nuclear power plant decommissioned concrete as a solidifying agent(SA) for radioactive waste. In order to evaluate the performance of the solidifying agent, a powder simulating the fine powder of waste concrete separated from the dismantled concrete of a nuclear power plant was produced, and the main variables were the type of binder and the replacement ratio of zeolite. The solidifying agent was evaluated for fluidity performance, compressive strength, and leaching resistance to non-radioactive cesium. The compressive strength of SA increased as the zeolite replacement ratio increased, and the SA containing 5% or more of zeolite showed a compressive strength that was 1.4 to 1.7 times higher than the acceptance criteria. The cesium leaching index of all specimens was 6 or higher, satisfying the acceptance criteria, and the leaching index of SA was 1.47~1.63 times higher than that of OPC. In particular, the average leaching index after 28 days of the 5% zeolite-substituted solidifying agent was 9.15, which was improved by about 6.4% compared to OPC, and it was confirmed that the zeolite was effective in improving the leaching resistance to cesium ions by showing stable performance over the entire period.

• Journal of Biosystems Engineering
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• v.6 no.1
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• pp.15-27
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• 1981

In order to investigate on the field performance of 3.5PS power tiller and to obtain the optimum using conditions of it, this experiment has been carried on the plowing operation, the rotary harrowing operation and the ridging operation that compared 3.5PS power tiller(KC-450) with the existing 5PS(DT-40) and 8PS(DT-85) power tiller. It has been performed at Suck Jung-Dong, Ansung Country, from March to October in 1980. The results of this field test were obtained as follows; 1. The plowing performance of KC-450 tiller was found to be 125min/10a that was lower than that of DT-85 tiller by 26min/10a in the effective plowing speed 0.9m/sec. 2. The field efficiency of KC-450 tiller was the highest among the power tillers as to be 82 persent that was higher than that of DT-85 tiller by 5 persent in the effective plowing speed 1m/sec. 3. The rotary harrowing performances of DT-40 tiller and DT-85 tiller were higher than that of KC-450 tiller in the rotary harrowing operation of the same speed, and the field efficiency of KC-450 tiller and DT-40 tiller were higher than that of DT-85 tiller in the rotary harrowing operation. 4. The ridging Performance of testing power tillers were nearly equality in the ridging operation of the same speed, and the field efficiency of testing tillers were higher KC-450 tiller than DT-40 tiller, DT-40 tiller than DT-85 tiller. 5. The work performance of power tiller increased with increase in the size of field area. Work performance and field efficiency of KC-450 tiller were higher than other tillers below 8a in field size 6. DT -85 tiller was more useful in deep plowing depth. But below 8a in field size KC-450 tiller was more easily operated and its field efficiency was higher 7. KC-450 tiller should be more useful to operate in the small size field or in the small scale farming and for the cultivation of vegetables, gardening plants, medicinal herb and tobacco plants, or for the cultivation in vinyl house.

• Women's Health Nursing
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• v.7 no.3
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• pp.317-330
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• 2001

This study was undertaken in order to examine the relationship of control, perceived health status, self efficacy, social support, and demographic characteristics to health promoting lifestyle of nursing students, and to determine factors affecting health promoting lifestyle of nursing students. The subjects were 270 students of a single university in Busan. The instruments used for this study was a survey of general characteristics, health promoting lifestyle (47 items), control(8 items), perceived health status(6 items), self-efficacy(17 items), and social support(18 items). Data analysis was done by use of mean, percentage, t-test, ANOVA, Pearson Correlation coefficients and stepwise regression with a SPSS PC+ program. The results of this study are as follows : 1) The average item score for the health promoting lifestyle was less than 2.43. In the sub-categories, the highest degree of performance was interpersonal relationships (2.94) and the lowest degree was health responsibility(1.93). 2) Students who were older and higher scores in health responsibility and interpersonal support subscale. Students who had higher grade had higher scores in health support subscale. Students who had experienced disease had higher scores in health responsibility subscale. Students who had experienced exercise had higher scores in health responsibility, exercise and nutrition subscale. 3) Significant correlation between control and self-efficacy, self-efficacy and social support was found. 4) Significant correlations was found between most of the subscales and total health promoting lifestyle. 5) Social support revealed significant correlations with total health promoting lifestyle and all subscales of health promoting lifestyle. Control revealed significant correlations with total health promoting lifestyle and self actualization and health responsibility. Perceived health status revealed significant correlations only with the exercise and nutrition subscale. Self-efficacy revealed significant correlation with the total health promoting lifestyle and all subscales of health promoting lifestyle except exercise and nutrition, stress management subscale. 6) Social support was the highest factor predicting health promoting lifestyles of nursing students(31%). Social support, excercise self-efficacy and control accounted for 35% in health promoting lifestyle of nursing students.

• Proceedings of the KSMRM Conference
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• 2003.10a
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• pp.103-105
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• 2003

After fifteen years of development, Magnetic Resonance (MR) technology for human imaging and spectroscopy is reaching a refined state with FDA approved 3T clinical products from Siemens, GE, and Philips. Broker has cleared CE approval with a 4T system. Varian supports a 4T system platform as well. Shielded magnets are standard at 3T from GE, Oxford, Magnex, and IGC. A shielded 4T whole body magnet is available from Oxford. Stronger switched gradients and dynamic shim coils, desired at any field, areespecially useful at higher static magnetic fields B0. In addition to the higher currents required for higher resolution slice or volume selection afforded by higher SNR, whole body gradient coils will be driven at increasing slew rates to meet the needs of new cardiac applications and other requirements. For example 3T and 4T systems are now being equipped with 2kV, 500A gradient coils and amplifiers capable of generating 4G/cm in 200msec, over a 67+/-cm bore diameter. High field EPI applications require oscillation rates at 1 kHz and higher. To achieve a benchmark 0.2 ppm shim over a 30cm sphere in a high field magnet, at least four stages of shimming need to be considered. 1) A good high field magnet will be built to a homogeneity spec. falling in the range of 100 to 150 ppm over this 30cm spherical "sweet spot" 2) Most modern high field magnets will also have superconducting shim coils capable of finding 1.5 ppm by their adjustment during system installation. 3) Passive ferro-magnetic shimming combined with 4) active, high order room temperature shim coils (as many as five orders are now being recommended) will accomplish 0.2 ppm over the 30cm sphere, and 0.1 ppm over a human brain in even the highest field magnets for human studies. Safety concerns for strong, fast gradients at any B0 field include acoustic noise and peripheral nerve stimulation. One or more of the mechanical decoupling methods may lead to quieter gradients. Patient positioning relative to asymmetric or short gradient coils may limit peripheral nerve stimulation at higher slew rates. Gradient designs combining a short coil for local speed and strength with a longer coil for coverage are being developed for 3T systems. Local gradients give another approach to maximizing performance over a limited region while keeping within the physiologically imposed dB0/dt performance limits.