• Korean Chemical Engineering Research
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• v.50 no.6
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• pp.1002-1007
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• 2012

The considerable portion of energy demand has been satisfied by the combustion of fossil fuel and the consequent $CO_2$ emission was considered as a main cause of global warming. As a technology option for $CO_2$ emission mitigation, absorption process has been used in $CO_2$ capture from large scale emission sources. To set up optimal operating parameters in $CO_2$ absorption and solvent regeneration units are important for the better performance of the whole $CO_2$ absorption plant. Optimal operating parameters are usually selected through a lot of actual operation data. However theoretical approach are also useful because the arbitrary change of process parameters often limited for the stability of process operation. In this paper, a theoretical approach based on vapor-liquid equilibrium was proposed to estimate optimal operating conditions of $CO_2$ absorption process. Two $CO_2$ absorption processes using 12 wt% aqueous $NH_3$ solution and 20 wt% aqueous MEA solution were investigated in this theoretical estimation of optimal operating conditions. The results showed that $CO_2$ loading of rich absorbent should be kept below 0.4 in case of 12 wt% aqueous $NH_3$ solution for $CO_2$ absorption but there was no limitation of $CO_2$ loading in case of 20 wt% aqueous MEA solution for $CO_2$ absorption. The optimal regeneration temperature was determined by theoretical approach based on $CO_2$ loadings of rich and lean absorbent, which determined to satisfy the amount of absorbed $CO_2$. The amount of heating medium at optimal regeneration temperature is also determined to meet the difference of $CO_2$ loading between rich and lean absorbent. It could be confirmed that the theoretical approach, which accurately estimate the optimal regeneration conditions of lab scale $CO_2$ absorption using 12 wt% aqueous $NH_3$ solution could estimate those of 20 wt% aqueous MEA solution and could be used for the design and operation of $CO_2$ absorption process using chemical absorbent.

• Journal of Bio-Environment Control
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• v.7 no.4
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• pp.298-310
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• 1998

This research was carried out to find out spray characteristics of 3 types of spray nozzle to be used for greenhouse cooling. Following results were obtained from this experimental study. Water amounts sprayed with each nozzle were increased with the spraying pressure. However the increment of sprayed amount with the increase of spraying pressure were not consistent regardless of nozzle types. For the whole tested spraying pressures of nozzle-type I, II, III, the minimum droplet sizes were about 1.7~2.5$\mu$m, 1.7~2.2$\mu$m and 1.7~2.2$\mu$m, respectively, and the maximum droplet sizes were about 44~60$\mu$m, 52~71$\mu$m and 45~61$\mu$m, respectively, and the average droplet sizes were about 23~38$\mu$m, 19~24$\mu$m and 17~25$\mu$m, respectively The most appropriate spraying pressures of nozzle-type I, II, III were analyzed to be 70kgf/$\textrm{cm}^2$, 30kgf/$\textrm{cm}^2$ and 30kgf/$\textrm{cm}^2$, respectively, and their sprayed amounts were about 124mL/min, 103mL/min and 84mL/min, respectively, and average droplet sizes were 22.6$\mu$m, 21.8$\mu$m and 20.6$\mu$m, respectively. Also, with the order of nozzle-type I, II, III, droplet size distributions less than 30$\mu$m were 95.4%, 85.7% and 79.0%, respectively, and the distributions larger than 40$\mu$m were 0.2%, 1.28% and 1.67%, respectively. However most all of the droplet size were less than 50$\mu$m.

• Asia-Pacific Journal of Business Venturing and Entrepreneurship
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• v.7 no.4
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• pp.101-112
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• 2012

Business consulting which aims at advising overall management, comparative advantage in competitive environment, administration and so forth is deemed to be significant so that a credit union may flexibly respond to rapid and complicated financial environment. Accordingly, business consulting has been initiated and implemented in credit union since 2002, which seemingly leads to positive outcome to enhance its competitiveness. However, very few research exists which analyze the credit union's competitiveness and business performance after the business consulting. Thus, the research intends to verify how consulting influences on management performance by its various factors. With the above studies in mind, hypothesis is formed that the characteristics of a consulting comsumer and the characteristics of supplier will give a meaningful impact on management performance. The test shows the result as followings: Firstly, a primary credit union's trust and NACUFOK's expertise demonstrate that they are closely relevant to financial and non financial management performance. Secondly, support and willingness to apply states that they influences on non financial performance, while no direct impact is found to financial performance. Thirdly, NACUFOK's capability is rarely interrelated to financial and non financial performance. The present study implies that the credit union as a consulting beneficiary should participate in the consulting, accept the result, and make effort to solve the management problems. In addition, NACUFOK as a consulting supplier should initiate the organization in exclusive charge, perform the professional group, and foster the professional consultant for the development of consulting method, the improvement of consulting process, and the specialization of consultant including the enhancement of core competencies. When these perspectives are sufficient, it will be connected to the management outcomes, further, it will be boosted up the competitiveness of the Credit Union. Hopefully the present study helps to motivate the consulting of primary credit union, boost up the effectiveness of consulting, further, providing the perspective on consulting the credit union. And these may result in the indication of consulting development direction and the competitiveness of Credit Union.

• Journal of Hospice and Palliative Care
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• v.8 no.2
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• pp.163-172
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• 2005

Purpose: This study is to identify the effect of a death education program to the nursing students on their anxiety of death and attitudes toward nursing care of the dying. Methods: The design of this study is nonequivalent control group pretest-posttest design. The subjects of experimental group 20 and control group 16 in senior grade of department of Nursing G university in J city. The experimental group had Death education Program, which was a three days per week program, for 2 weeks. And post-test was carried out in the same way as the pre-test. Data analysis was done using frequency, percentage, mean, standard deviation, Chi-square test, t-test, paired Sample t-test using with SPSS win 10.0. Results: the experimental group was decreased in degree of anxiety of death and was improved in degree of positive attitudes toward nursing care of the dying. Conclusion: The death Education Program can be an effective nursing education program for their Nursing students to decrease their death anxiety and to prepare care of the dying.

• Journal of Hospice and Palliative Care
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• v.13 no.4
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• pp.232-242
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• 2010

Purpose: This study was done to investigate effects of foot massage and supportive communication provided by hospice volunteers on depression, anxiety, and mood of cancer patients who are going under intravenous chemotherapy at out patient department (OPD). Methods: A non-equivalent control group non-synchronized design was used. Sixty-four participants were recruited from out-patients setting in a university hospital by a convenient sampling. Two trained- hospice volunteers first provided regular hospice volunteer service to 34 patients in the control group. Subsequently, foot massage and supportive communication were provided to 30 participants in the experimental group. After the intervention, all participants answered the structured questionnaire with visual analog scales on depression, anxiety, and mood including general characteristics. Data were analyzed using descriptive statistics, two sample t-test, and paired t-test by PASW 17. Results: After the intervention, changes in negative moods, i.e. strain and powerlessness in the experimental group were significantly different from those in control group; strain and powerlessness in the experimental group were significantly decreased by foot massage and supportive communication provided by hospice volunteers. Conclusion: The current findings provide an empirical evidence of a brief and efficacious intervention for cancer patients. Further studies are warranted with larger sample size to validate the effectiveness of foot massage and supportive communication as a solid intervention for cancer patients who are undergoing intravenous chemotherapy at OPD.

• Journal of the Korean Society of Radiology
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• v.14 no.5
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• pp.563-575
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• 2020

The purpose of this study is to evaluate the activation characteristics that occur in a linear accelerator for container security inspection. In the computer simulation design, first, the targets consisted of a tungsten (Z=74) single material target and a tungsten (Z=74) and copper (Z=29) composite target. Second, the fan beam collimator was composed of a single material of lead (Z=82) and a composite material of tungsten (Z-74) and lead (Z=82) depending on the material. Final, the concrete in the room where the linear accelerator was located contained magnetite type and impurities. In the research method, first, the optical neutron flux was calculated using the MCNP6 code as a F4 Tally for the linear accelerator and structure. Second, the photoneutron flux calculated from the MCNP6 code was applied to FISPACT-II to evaluate the activation product. Final, the decommissioning evaluation was conducted through the specific activity of the activation product. As a result, first, it was the most common in photoneutron targets, followed by a collimator and a concrete 10 cm deep. Second, activation products were produced as by-products of W-181 in tungsten targets and collimator, and Co-60, Ni-63, Cs-134, Eu-152, Eu-154 nuclides in impurity-containing concrete. Final, it was found that the tungsten target satisfies the permissible concentration for self-disposal after 90 days upon decommissioning. These results could be confirmed that the photoneutron yield and degree of activation at 9 MeV energy were insignificant. However, it is thought that W-181 generated from the tungsten target and collimator of the linear accelerator may affect the exposure when disassembled for repair. Therefore, this study presents basic data on the management of activated parts of a linear accelerator for container security inspection. In addition, When decommissioning the linear accelerator for container security inspection, it is expected that it can be used to prove the standard that permissible concentration of self-disposal.

• Food Science of Animal Resources
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• v.25 no.4
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• pp.449-457
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• 2005

This study was conducted to evaluate the effects of feeding rye silage on growth performance, blood and carcass characteristics in finishing pigs. The total of eighteen $(Landrace{\times}Yorkshire{\times}Duroc)$ pigs $(94.03\pm0.71kg)$ were used in a 28-days assay. Dietary treatments included 1) CON(commercial diet ME 3,350 kcal/kg and crude fiber $2.84\%$), 2) T1(ME 3,294kcal/kg and crude fiber $2.99\%$ diet with rye silage $1.66\%$) and 3) T2(ME 3,237kcal/kg and crude fiber $3.15\%$ with rye silage $3.32\%$). In growth performance, total feed intake, basal feed intake and average daily feed intake were significantly higher in T1 and T2 treatments than CON treatment(P<0.05). Cortisol concentration in blood of pigs fed rye silage was significantly decreased compare to pigs fed CON diet(p<0.05). In meat quality characteristics, the hunter's $L^*$ value and marbling of pork were the highest in T2 treatment among treatments (P<0.05). Fatty acid composition in lean meat, the composition of palmitic and arachidic acid were significantly Higher in CON than others(P<0.05), also, palmitoleic acid was highest in T2 treatment among treatments(P<0.05). In fats those, palmitic and arachidic acid were the highest in CON treatment than those of other treatments(P<0.05). Digestibility of dry matter and nitrogen in pigs fed T1 and T2 diets were greater than that of pigs fed CON diet(p<0.05). Propionic acid concentration of fecal was the highest in T1 treatment among treatments(P<0.05). In conclusion, feed intake, the hunter's $L^*$ value, meat color of sensory evaluation and marbling of pork were affected by $3.32\%$ rye silage feeding.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.18 no.10
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• pp.136-152
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• 2017

The thermodynamic models, PC-SAFT (Perturbed-Chain Statistical Associated Fluid Theory) state equation and the Two-model approach liquid activity coefficient model NRTL (Non Random Two Liquid) + Henry + Peng-Robinson, for modeling the Rectisol process using methanol aqueous solution as the $CO_2$ removal solvent were compared. In addition, to determine the new binary interaction parameters of the PC-SAFT state equations and the Henry's constant of the two-model approach, absorption equilibrium experiments between carbon dioxide and methanol at 273.25K and 262.35K were carried out and regression analysis was performed. The accuracy of the newly determined parameters was verified through the regression results of the experimental data. These model equations and validated parameters were used to model the carbon dioxide removal process. In the case of using the two-model approach, the methanol solvent flow rate required to remove 99.00% of $CO_2$ was estimated to be approximately 43.72% higher, the cooling water consumption in the distillation tower was 39.22% higher, and the steam consumption was 43.09% higher than that using PC-SAFT EOS. In conclusion, the Rectisol process operating under high pressure was designed to be larger than that using the PC-SAFT state equation when modeled using the liquid activity coefficient model equation with Henry's relation. For this reason, if the quantity of low-solubility gas components dissolved in a liquid at a constant temperature is proportional to the partial pressure of the gas phase, the carbon dioxide with high solubility in methanol does not predict the absorption characteristics between methanol and carbon dioxide.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.8 no.1
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• pp.123-136
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• 2004

In this paper, complexity and regularity of polynomial multiplication over $GF({2^n})$ are defined by using Hamming weight of rows and columns of the matrix ever GF(2) which represents polynomial multiplication. It is shown experimentally that in order to construct the block cipher robust against differential cryptanalysis, polynomial multiplication of substitution layer and the permutation layer should have high complexity and high regularity. With result of the experiment, a way of constituting S box and G function is suggested in the block cipher whose structure is similar to SEED, which is KOREA standard of 128-bit block cipher. S box can be formed with a nonlinear function and an affine transform. Nonlinear function must be strong with differential attack and linear attack, and it consists of an inverse number over $GF({2^8})$ which has neither a fixed pout, whose input and output are the same except 0 and 1, nor an opposite fixed number, whose output is one`s complement of the input. Affine transform can be constituted so that the input/output correlation can be the lowest and there can be no fixed point or opposite fixed point. G function undergoes linear transform with 4 S-box outputs using the matrix of 4${\times}$4 over $GF({2^8})$. The components in the matrix of linear transformation have high complexity and high regularity. Furthermore, G function can be constituted so that MDS(Maximum Distance Separable) code can be formed, SAC(Strict Avalanche Criterion) can be met, and there can be no weak input where a fixed point an opposite fixed point, and output can be two`s complement of input. The primitive polynomials of nonlinear function affine transform and linear transformation are different each other. The S box and G function suggested in this paper can be used as a constituent of the block cipher with high security, in that they are strong with differential attack and linear attack with no weak input and they are excellent at diffusion.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.19 no.9
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• pp.279-287
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• 2018

Sealants are an important element of modern architecture and serve as a building protection against weathering by providing barriers against ingress of moisture, air, and other materials. Exposure to a variety of environments often reduces lifespan due to changes in physical, chemical and mechanical characteristics, and UV, humidity, and temperature expansion are important issues that are directly related to durability. In this study, a combined deterioration test chamber was developed to simulate the environment of the open air as an instrument for verifying the durability of structural sealing materials indoors. In order to replicate special weather conditions, such as yellow dust, acid rain, and contamination by microorganisms, it was deemed impossible to replicate the outdoor environment by 100 %, and the results of the results of the results of the external exposure test of the structural sealant and the combined deterioration testing device. As a result of the displacement test of the outdoor exposure test, it was determined that the sealant was breaking apart and that it would be smooth, and the displacement would be up to three times greater than the initial material value of 1 year. The displacement test results of the combined deterioration test device show the tendency to deteriorate, decreasing the elasticity and tensile characteristics. In the case of denatured silicon, the current 400 cycles have been completed to confirm 12 months of degradation of the external exposure. The deformation of the test specimen cannot be verified with the naked eye, so it is considered that the conditions of the specimen are more stable than the silicon sealant. As a result of the outdoor exposure test, if the combined deterioration test device is structured and proposed in the relevant guidance or specification, the anticipated lifespan of 12 months in the actual use environment can be verified indoors and below 3 months later, economically.