• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.17 no.12
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• pp.1341-1346
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• 2004

The OLED research is gone for two directions. One is material development research, and another one is structural improvement part. All two are thing to heighten luminescence efficiency of OLED. n other to improve luminescence efficiency of OLED Electron - hole pairs must consist much more in the device Their profiles are sensitive to mobility velocity of electrons and holes. In this paper, we demonstrate the difference of velocity between hole and electron by experiments, and compare with a data of simulation and experiment changing hole carrier transport layer thickness, so we get the optimal we improve luminescence efficiency. We suggest improving the efficiency of OLEDS would be to balance the injection of electrons and holes into light emission layer of the device. And, we improve understanding of the various luminescence efficiency through experiments and numerical analysis of luminescence efficiency in variable hole carrier transport layer's thickness.

• Natural Product Sciences
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• v.19 no.1
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• pp.1-7
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• 2013

AMP-activated protein kinase (AMPK) is a major cellular energy sensor and master regulator of metabolic homeostasis. On activation, this cellular fuel sensing enzyme induces a series of metabolic changes to balance energy consumption via multiple downstream signaling pathways controlling nutrient uptake and energy metabolism. This pivotal role of AMPK has led to the development of numerous AMPK activators which might be used as novel drug candidates in the treatment of AMPK related disorders, diabetes, obesity, and other metabolic diseases. Consequently, a number of patents have been published on AMPK activators from natural products and other sources. This review covers the patented AMPK activators from natural products and their therapeutic potential in treatment or prevention of metabolic diseases including diabetes and obesity.

• The Journal of the Korea Contents Association
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• v.16 no.8
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• pp.693-705
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• 2016

The purposes of this study were to develop work-life balance supportive organizational culture scale(WLB supportive organizational culture) and to verify it's validity. We reviewed comprehensive studies about work-life balance and organizational culture as well as scales related to them. We theoretically extracted some important factors of WLB organizational culture from reviews and then made 38 preliminary questions. 773 married workers in their 30s to 50s were responded to a questionnaire consisted of 38 preliminary questions and 9 variables(work-life balance, quality of life, job satisfaction, turnover etc) for criterion related validity verification. As the results of factor analysis such as EFA and CFA, we could confirm five factors including WLB organizational management, WLB supportive supervisors, empathetic communication with coworkers, coworkers' material support to WLB and accessibility to WLB programs. Second, correlation analyses were performed to investigate the validation of this scale. In result, it was revealed that the WLB supportive organizational culture scale was highly correlated with other family supportive organizational culture measures as well as dependent variables such as work-life balance, quality of life, job satisfaction, turnover. We expect this study contribute to improve the quality of studies about work-life balance and organizational culture.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.34 no.12
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• pp.90-95
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• 2006

The wall of thermal vacuum chamber which is used for the satellite thermal balance test doesn't absorb satellite's IR emission perfectly and reflects some part of that. It is estimated that small thermal vacuum chamber has relatively larger wall effect than the big one. The small thermal vacuum chamber is required for the small satellite test to reduce the test cost. A quantitative analysis was carried out to investigate the chamber wall effect. As a result, temperature errors caused by chamber wall effect was calculated, and the temperature data acquired in the thermal balance test have been compensated. By defining the optimized area ratio between chamber surface and satellite surface area, the baseline to be able to determine the minimum size of thermal vacuum chamber was established to minimize the wall effect. Also, theoretical analysis about transparent material coating which can reduce the chamber wall effect is conducted.

• Analytical Science and Technology
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• v.30 no.5
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• pp.226-233
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• 2017

In general, quantitative chemical analysis in various areas including food, the environment, in vitro diagnostics, etc., requires traceability in order to increase the reliability of the measurements. Measurement traceability is a property of an unbroken chain of comparisons relating an instrument's measurements to SI units. Purity analysis is the first process for establishing traceability to SI units in chemical measurements. The purpose of this study is to develop and validate a method of purity assignment for establishing the traceability of $17{\beta}$-estradiol measurements in an in vitro diagnostics field. The establishment of this method is very important as it can be applied to the development of CRM and to the analysis of the purity of other hormones. The method of assignment of the purity of $17{\beta}$-estradiol was developed using the mass balance method and was validated through participation in an International comparison. In the mass balance method, impurities are categorized into four classes as follows: total related structure impurities, water, residual organic solvents, and nonvolatiles/inorganics. In this study, total related structure impurities were characterized by a gas chromatography-flame ionization detector (GC-FID) and a high-performance liquid chromatography-ultraviolet (HPLC-UV) detector, water content was determined by a Karl-Fisher coulometer, and total residual solvents and nonvolatiles/inorganics were checked simultaneously by thermogravimetric analysis (TGA). The purity of the $17{\beta}$-estradiol was 985.6 mg/g and the expanded uncertainty was 2.1 mg/g at 95% confidence. The developed method can be applied to the development of certified reference materials, which play a critical role in traceability.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.27 no.3
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• pp.123-127
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• 2015

Thermochemical heat storage is a cutting-edge technology which can balance the energy usage between supplies and demands. Recent studies have suggested that thermochemical heat storage has significant advantages, compared to other storage methods such as latent heat storage or sensible heat storage. Nevertheless, ongoing research and development studies showed that the thermochemical heat storage has some serious problems. To bring the thermochemical heat storage method into market, we introduce experimental setup with composite material using perlite that supports calcium chloride sorbent. Also, to compare thermal properties with composite material, we used pure thermochemical material. Then, we found that the composite material has higher heat storage density by mass than pure calcium chloride. Moreover, it can be easily regenerated, which was impossible in the pure thermochemical materials.

• Nuclear Engineering and Technology
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• v.51 no.1
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• pp.198-206
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• 2019

A new methodology to analyze the nuclear material accountability for pyroprocessing system is developed. The $Pu-to-^{244}Cm$ ratio quantification is one of the methods for Pu accountancy in pyroprocessing. However, an uncertainty in the $Pu-to-^{244}Cm$ ratio due to the non-uniform composition in used fuel assemblies can affect the accountancy of Pu. A random variable, LOPu, is developed to analyze the probability of detection for Pu diversion of hypothetical scenarios at a pyroprocessing facility considering the uncertainty in $Pu-to-^{244}Cm$ ratio estimation. The analysis is carried out by the hypothesis testing and the event tree method. The probability of detection for diversion of 8 kg Pu is found to be less than 95% if a large size granule consisting of small size particles gets sampled for measurements. To increase the probability of detection more than 95%, first, a new Material Balance Area (MBA) structure consisting of more number of Key Measurement Points (KMPs) is designed. This multiple KMP-measurement for the MBA shows the probability of detection for 8 kg Pu diversion is greater than 96%. Increasing the granule sample number from one to ten also shows the probability of detection is greater than 95% in the most ranges for granule and powder sizes.

• Journal of rehabilitation welfare engineering & assistive technology
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• v.5 no.1
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• pp.47-52
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• 2011

The functional loot orthoses, when wearing shoes, are in the direct contact with bottom of foots to improve and recover the correctness of abnormal lower limb musculoskeletal imbalance and the primary role of foot and also, it can act to keep the balance and weight of body and support the weakened region, so that it is very helpful to keep body balance for the standing position. In this paper, it was researched that foot orthoses which is accommodable for the function of impact absorption including the gait stability affect on the balanced performances of body in according to the formation and the material of foot part. Taking into account the balanced performances by using the sway velocity, the estimation and comparison of the effects on the balanced performances by each formation and material for foot orthoses was evaluated into significant values(p<0.006) in only the eye-opening posture with Firm state, In this posture, the static process performed by each foot formation reveals in order of normal foot(p<0.010), flat foot(p<0.000) and hollow foot(p<0.003) and then, on the base of each formation of foot part, the result that analyze the effects of the materials of foot orthoses on the balance performance appeared showing that soft materials is more effective on the normal foot and, on the other hand, rigid materials is more effective in balancing on flat foot and hollow foot.

• Journal of the Korean Institute of Gas
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• v.22 no.1
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• pp.64-77
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• 2018

This paper presents the prediction of the original gas in place(OGIP) by using the material balance method and decline curve analysis method with production history and pressure transient test data for four coalbed methane wells in the Horseshoe Canyon field. In this study, the conventional gas equation and the Jensen and Smith(J&S) equation were used to material balance analysis, and the Arps' empirical correlation and Khaled method were applied to decline curve analysis. From the results, the OGIP estimated from the conventional gas and the J&S method was small in difference as under 12%. Also, in case of decline curve analysis, it was found that the Khaled method has appropriated to calculate the OGIP, because the OGIP was estimated as unlimited value by the Arps' equation from the decline exponent of 1 - 3.5. The OGIP difference between conventional gas method and Khaled method was calculated as 8.67% ~ 31.04%, and those between J&S method and Khaled method was 13.67% ~ 26.49%.

• 한국가스학회:학술대회논문집
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• 1998.09a
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• pp.241-246
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• 1998

This paper considers the applicability of a pseudosteady-state approach to the long-time behavior of real gas flow in a closed reservoir. The method involves a combination of a linearized gas diffusivity equation using a normalized pseudotime and a material balance equation. Comparison with a commercial reservoir simulator showed that highly accurate values of pseudopressure drawdown and well pressure are obtained by the pseudosteady-state approach with much less computational effort.