• Knowledge Management Research
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• v.22 no.2
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• pp.269-288
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• 2021

In a rapidly changing corporate environment, the relationship among organizational justice, job attitude, and cynicism as factors influencing exit, voice, loyalty, and neglect that can promote the performance improvement of organizational members was analyzed with the PLS (Partial Least Squares) structural equation in two stage approach. Organizational justice constitutes a formative secondary factor by the first order of distributional justice, procedural justice, and interactional justice, and job attitude is a formative secondary factor of job satisfaction and organizational commitment. We analyze the direct and indirect effects by mediating relationships of cynicism and job attitude on the factors such as exit, voice, loyalty, and neglect. From the perspectives of knowledge management, we analyzed how the perception of organizational justice affects the overall performance of the organization through the improvement of the employees' performance.

• Journal of the Korean Society of Clothing and Textiles
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• v.16 no.2
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• pp.181-187
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• 1992

일반적으로 면섬유는 햇빛에 의해서 변색되거나 약해지며 또 그 외에도 여러가지 물리적, 화학적인 변화를 일으키게 된다. 구체적인 화학반응의 메카니즘은 사용되는 광선의 스펙트럼, 대기조건(실내인 경우는 실내 환경조건) , 산소의 유무 그리고 염료 등 첨가물의 종류와 같은 여러 요소에 의해 크게 영향을 받게 된다. 환경조건 중에서 산소의 존재는 매우 중요하지만 open system에서 산소의 농도가 일정하다고 가정할 때 면섬유가 접하고 있는 환경조건 중에서 온도와 습도는 photodegradation의 속도를 결정짓는 중요한 요인으로 작용하게 된다. 박물관,:기념관, 도서관 등의 소장품이 자연광선이나 인공조명으로부터 손상되는 것을 막기 위해서는 먼저 이들의 photodegradation 현상에 대한 연구를 필요로 한다. 본 연구에서는 면시칩포를 자연광선과 가장 흡사한 스펙트럼을 가진 xenon arc lamp를 사용한 내후도 시험기내에서 온도와 습도를 조절하여 이에 따른 반응속도의 차이를 인열강도의 감소와 중합도 저하로 측정하였다. 1차 반응식은 실험결과를 설명하는데 유용하였으며 온 · 습도의 증가는 반응속도를 증가시키는 것으로 나타나 기존의 상반된 연구결과의 차이를 입증하였다. 또 온도와 습도는 상호관련이 있는 것으로 나타났으며 고온인 경우습도의 영향을 더 크게 받는 것으로 분석되었다. 반응의 활성에너지는 $30\~75\%$ RH에서는 12 kcal/mole 정도이며 수분의 함량이 낮을수록 활성화에너지는 커지는 것으로 나타나 수분은 섬유소 분자구조내에서 가소제 (plasticizer)의 역할을 하는 것으로 판명되었다.

• Clean Technology
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• v.23 no.4
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• pp.413-420
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• 2017

The batch experiments and response surface methodology (RSM) have been applied to the investigation of the Cs adsorption with zeolite X synthesized using coal fly ash generated from the thermal power plant. Regression equation formulated for Cs adsorption was represented as a function of response variables. The model was highly relevant because the decision coefficient ($r^2$) was 0.9630. It was confirmed from the statistical results that the removal efficiency of Cs was affected by the order of experimental factors as pH > Cs concentration > temperature. The adsorption kinetics were more accurately represented by a pseudo second-order model. The maximum adsorption capacity calculated from the Langmuir isotherm model was $151.52mg\;g^{-1}$ at 293 K. Also, according to the thermodynamic parameters calculated from Vant Hoff equation, it could be confirmed that the adsorption reaction was an endothermic reaction and a spontaneous process.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 1996.11a
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• pp.137-144
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• 1996

The kinetic coefficients far decomposition of the cured phenol resin (SC-1008) using a modified Arrhenius relationship have been determined from thermogavimetric analyses (TGA). The kinetic parameters were determined by multiple heating rate technique developed by Freideman and Henderson. Weight loss (decomposition) and weight loss rate (decomposition rate)were measured and recorded for three heating rates; $5^{\circ}C$/min ,$10^{\circ}C$/min, and $20^{\circ}C$/min. Relatively good agreement was obtained between measured and calculated decomposition as a function of temperature. By separating the reaction, the reaction order and pre exponential factor become empirical parameters which provide a "best fit" of the data. However, this method yields an extremely accurate reproduction of the thermograms over a wide range of heating rates. This is the desired result for kinetic parameters used in thermal models.al models.

• Polymer(Korea)
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• v.30 no.1
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• pp.45-49
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• 2006

In this study, it was investigated on the boron separation ken synthetically prepared seawater. ion exchange resin used in the experiments was Amberlite IRA 743, containing glucamine functional group. The experiments were carried out as a function of the conditions of the pH, boron initial concentration and temperature of seawater in a batch reactor. As a result, optimum conditions for boron adsorption were at pH 8.5 and 313 K, respectively. The adsorption rate was increased very fast with increasing the temperature, but decreased with increasing the initial concentration of boron. Also, the kinetics for boron adsorption applied the pseudo-second order model, as follows: $$\frac{X}{1-X}=780[C_0]^{-1.65}t^{1.48}\;exp\;({-\frac{17883}{RT}}\)\;;\;pH8.5$$

• Journal of Environmental Impact Assessment
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• v.32 no.6
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• pp.431-436
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• 2023

As the industry develops, the amount of heavy metals flowing into the ecosystem is increasing. Heavy metals are difficult to decompose and remain in the ecosystem for a long time and cause toxicity, which is removed by physicochemical methods such as adsorption, filtration, and chemical precipitation during water treatment. In this study, Alginate bead was selected as a chelating resin for adsorbing and removing heavy metals, and the Jellyfish Extract at Immunity reaction (JEI) were mixed to evaluate the adsorption efficiency of heavy metals accordingly. beads mixed with JEI showed high adsorption efficiency in lead (79-99%) and copper (64-70%) according to the characteristics of Alginate, and low adsorption efficiency in cadmium (25-37%) and zinc (5-6%). Although heavy metal adsorption did not increase in proportion to the content of JEI, 50% and 100% JEI beads showed significant increases. As a result of applying the reaction rate equation, it was found that it was more suitable for the pseudo-secondary reaction equation than the pseudo-first reaction equation.

• Science of Emotion and Sensibility
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• v.20 no.1
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• pp.115-132
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• 2017

Differences in reaction time and accuracy were compared among driver groups of middle-, old-, and stroke old-age drivers using various reaction time tasks including simple reaction task, 2-choice task, 4-choice task with different stimuli eccentricity, search task, and moving target detection task. The results can be summarized as followings. First, although overall reaction time tended to be slowed with age and stroke, stroke old drivers showed significantly slower reaction time than the other driver groups when the stimuli were presented in a large eccentricity. Second, differences in reaction time for 2-choice task and moving target detection task seemed to be determined mainly by participants' simple reaction time. Third, the search task which required temporary retention of previously presented stimuli was found to be more sensitive in discriminating difference in reaction time between middle-age drivers and old-age drivers (including stroke old drivers). Fourth, reaction accuracy of old (and stroke old) drivers decreased when more stimuli alternatives were presented and temporary retention for stimuli was required. Altogether, memory demand in reaction time task can be sensitive to evaluate performance for different age groups, whereas size of useful field of view for brain stroke.

• Journal of the Korean GEO-environmental Society
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• v.11 no.1
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• pp.45-51
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• 2010

Cadmium (Cd) adsorption by the activated carbon containing hydroxyapatite (HAP) was investigated. Cd adsorption with different HAP mass ranged from 10% to 30%. With more HAP, more Cd was adsorbed. These results suggest that the higher HAP dose causes an increase of the ion exchange potential in HAP sorbent. Kinetics and equilibrium studies were investigated in series of batch adsorption experiments. Langmuir and Freundlich isotherm models were fit to the equilibrium data and Cd adsorption on HAP sorbent were found to follow the Freundlich isotherm model well in the initial adsorbate concentration range. The simple kinetic model, the pseudo first order kinetic model and the pseudo second order kinetic model, were used to investigate the adsorption. The adsorption reaction of Cd followed the pseudo second order kinetic model, and the adsorption pseudo second order kinetic constants ($k_2$) increased with increasing initial HAP amounts onto activated carbon. Also, intraparticle diffusion model was used to investigate the adsorption mechanism between adsorbate and adsorbent in the aqueous phase. Surface adsorption reaction and intraparticle diffusion occur simultaneously Cd adsorption mechanism from aqueous phase in this study.

• Korean Journal of Food Science and Technology
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• v.34 no.2
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• pp.238-243
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• 2002

The effects of concentration and temperature on degradation of anthocyanins of purple-fleshed sweet potato pigment concentrate and a Japanese plum juice were determined over temperature ranges of 60 to $90^{\circ}C$ and 5 to $60^{\circ}C$, respectively. Degradation of anthocyanins in pigment concentrates followed the first-order reaction rate. Activation energies of the pigment solutions ranged 51.29-73.02 kJ/mol, linearly decreasing as concentration increased except the pigment solution of $8.4^{\circ}Brix$ which was not concentrated after extraction. Anthocynins in Japanese plum juice was also degraded by the first-order reaction kinetics with activation energy of 75.80 kJ/mol. Storage life of the beverage was extended with decreasing storage temperature. Pigment was ratained more than 80% until 8 months storage at $5^{\circ}C$.

• Korean Journal of Food Science and Technology
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• v.32 no.1
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• pp.147-153
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• 2000

We could produce algin-like biomaterial of polyiduronan using polyglucuronic acid C5-epimerase with polyglucuronic acid prepared by specific oxidation of primary alcohol groups of four kinds of polysaccharides(corn starch, rice starch, sweet potato starch, and cellulose). The enzyme activity was determined by the modified Dische carbazole methodology with the isolated crude enzyme from the supernatant centrifuged at $100,000{\times}g$ for 1 hr after grinding fresh bovine liver. And then, the optimal substrate, pH, and temperature for the enzyme reaction of polyglucuronic acid C5-epimerase were determined as the oxidized sweet potato starch, 7.0, and $30^{\circ}C$, respectively. Conclusively, it could be possible to epimerize polyglucuronic acid in the oxidized sweet potato starch to polyiduronic acid. Therefore, we could obtain algin-like polysaccharide using the oxidized sweet potato starch and polyglucuronic acid C5-epimerase isolated from bovine liver.