• Journal of the Korea Concrete Institute
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• v.26 no.3
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• pp.315-321
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• 2014

Concrete as a construction material is widely used in nuclear vessel and plant for excellent radiation shielding. However the isolation characteristics in concrete may affect adversely in the case of fire and melt-down in nuclear vessel since temperature cooling down is very difficult from outside. This study is for development of high thermal conductive concrete, and its mechanical and thermal properties are evaluated. Magnetite aggregates with volume ratio of 42.3% (maximum) and steel powder of 1.5% are replaced with normal aggregates and thermal properties are evaluated. Thermal conductivity little increases by 30% addition of magnetite but rapidly increases afterwards. Finally thermal conductivity is magnified to 2.5 times in the case of 42.3% addition of magnetite. Steel powder has a positive effect on high thermal conduction to 106~113%. Several models for thermal conduction like ACI, DEMM, and MEM are compared with test results and they are verified to reasonably predict the thermal conductivity with increasing addition of magnetite aggregates and steel powder.

• Journal of the Korean Society of Food Science and Nutrition
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• v.46 no.1
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• pp.77-82
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• 2017

The purpose of this study was to evaluate the quality of crackers added with different concentrations (0%, 3%, 5%, 7%, and 10%) of tomato concentrate. The study results found that pH and baking loss rate of crackers of the control were higher than those of the samples. On the other hand, density and moisture of crackers with 10% tomato concentrate were higher than those of the samples. Hunter L values of crackers decreased as concentration of tomato concentrate increased, whereas a and b values of crackers increased. In the texture analysis, hardness of crackers decreased according to concentration of tomato concentrate. DPPH free radical scavenging activity of crackers increased as concentration of tomato concentrate increased. In the sensory evaluation, taste, color, flavor, texture, and overall acceptability of crackers added with 5% tomato concentrate were higher than those of other samples. Therefore, the results suggest that addition of 5% tomato concentrate is effective for increasing consumer acceptability and functionality of crackers.

• Journal of Advanced Marine Engineering and Technology
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• v.38 no.9
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• pp.1070-1074
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• 2014

According to IEEE 1662(2009), IPS is a power system where all prime movers produce electrical power that is shared among propulsion, mission, and ship service loads. Discriminating attributes of integrated power systems are flexibility of movers' arrangements, mechanical decoupling between prime movers and propulsors, an increased level of energy conversion and transmission redundancy, and flexibility of redistributing available electrical power for future electronic weapons. IPS could have various steps of power that can be produced at optimal load of movers. In this study, an evaluation method for optimal arrangement of movers was investigated when an IPS warship is projected. The two factors are utilized for the quantitative analysis which are the weight of system as the fighting power and the fuel consumption per year as the economic feasibility. And also the ways for arrangement of system were studied according to existence of small diesel generator. The evaluation method that decides the optimization level is based on the DEA(Data Envelopment Analysis)

• Journal of Bio-Environment Control
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• v.23 no.2
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• pp.131-138
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• 2014

'Hanareum' pear is expected to produce the high quality small and medium-sized fruits without any major changes in the current cultivation techniques, inasmuch as its basic characteristics are already included in the range of small and medium-sized fruits. Thus, we tested the possibility of utilization of 'Hanareum' pear for producing small and medium-sized fruits, while establishing the limit of minimum fruit weight for the fruits in high quality. With the results of correlation analysis, it was possible to predict the fruit weight through the observation of soluble solid contents and flesh firmness, because both factors were closely correlated to fruit weight in all treatments. Moreover, these factors were confirmed to be useful indicators of forecasting consumer preference in the sensory evaluation. The fruit marketability was excellent under the conditions that were greater than $11.6^{\circ}Bx$ and less than 25.6 N for soluble solid contents and flesh firmness, respectively. When applying these standards of fruit quality to the results of regression analysis for fruit weight, non-treated fruits fulfilled both standards when the fruit weight was higher than 436 g, and the quality uniformity was also high on this state. Therefore, the production of high quality small and medium-sized fruits was determined to be under this condition. The weight limit for GA treated fruits was 620 g, and both fruit quality and uniformity were below the weight range of small and medium-sized fruits, with 300~500 g. Thus, GA treatment was suggested to be avoided, in order to produce the high quality small and medium-sized fruits.

• Journal of Korean Society on Water Environment
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• v.22 no.6
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• pp.1119-1122
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• 2006

Aeration by using diffusers usually requires approximately 50~90% of the total electricity needed to operate WWTP (WasteWater Treatment Plant)s. Accurate evaluation of the oxygen transfer efficiency for an aeration system, and recommendation of a better alternative may help saving WWTP operational costs. Appropriate techniques and methods to achieve this purpose have not been introduced in Korea. In this study, in-process analysis was performed for a coarse bubble aeration system by the off-gas method to evaluate its applicability in Korea. To accomplish this analysis, an off-gas test, unsteady-state clean water test and steady-state off-gas column test was conducted and comparisons to other aeration systems were made. The ${\alpha}$ and the F estimated from the results of the unsteady-state clean water test and the steady-state off-gas column test were 0.61 and 0.90 respectively in a coarse bubble aeration system. The comparison of P.E tube diffusers laid out single spiral roll and ceramic dome diffusers laid out full floor coverage showed that the oxygen transfer efficiency of the coarse bubble aeration system was less than or similar to other aeration systems. But, airflow rates per unit area were 4~5 times greater than other aeration systems. In regards to the oxygen transfer efficiency for airflow rates per unit area, a retrofit to higher efficiency diffusers was urgently needed. This study showed proved that off-gas methods can apply to evaluate diffuser performances to estimate operating factors and to compare other aeration systems in Korea.

• Journal of the Korean Society of Food Science and Nutrition
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• v.43 no.2
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• pp.265-272
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• 2014

In this study, we investigated the quality properties and sensory evaluation of pudding added with peach (Prunus persica L. Batsch) juice and gelatin. The water content and pH of pudding decreased with increased peach juice content, whereas the sugar content increased. Further, the water content of pudding decreased with increased gelatin content, whereas the pH was constantly maintained and the sugar content slightly increased. Regarding the color of pudding, the L and b values decreased with increased peach juice content, whereas the L value increased with increased gelatin content. Regarding the texture of pudding, hardness and springiness decreased with increased peach juice content, whereas adhesiveness, chewiness, and cohesiveness all increased. All texture properties increased with higher gelatin content. In the sensory evaluation of color, flavor, taste, texture, and overall preference, pudding with 60% (w/w) peach juice and 1.5% (w/w) gelatin showed the highest values. These results demonstrate the possibility of using high value-added products for peach processing in the food industry, as the addition of peach juice and gelatin enhanced the quality and sensory properties of pudding.

• Journal of Wetlands Research
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• v.22 no.2
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• pp.139-144
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• 2020

Recently, high-concentration linked wastewater has been introduced into a nearby municipal wastewater treatment plants(MWTPs), but it is difficult to MWTP in local governments due to an unreasonable linked treatment charge system, and there is insufficient evidence or data to prove this. However, the MWTP, which is a national essential infrastructure, is generally exempt from the preliminary feasibility study, so there have been no cases where economic evaluation was conducted. Therefore, we proposed an improvement plan that can compensate for the disadvantages of the existing linked processing charges through previous studies. In this study, a comparative evaluation of how much economic feasibility can be improved compared to the existing ones when applying the improvement plan by conducting an economic analysis. For this, reference was made to the preliminary feasibility assessment data of the existing environmental facilities and the cost factors and benefit factors established during the modernization of the old sewage treatment facilities. As a result of the study, the B/C(Benefit/cost) value was quite low in the past, but when the improvement proposal proposed by the researchers was applied, it was confirmed that the B/C value increased close to 1. Therefore, it is considered to be very reasonable to calculate the linkage processing charge according to the linked wastewater load proposed by the researchers.

• Journal of the Institute of Convergence Signal Processing
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• v.4 no.1
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• pp.15-26
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• 2003

Ultrasonic inspection methods are widely used for detecting flaws in materials. The signal analysis step plays a crucial part in the data interpretation process. A number of signal processing methods have been proposed to classify ultrasonic flaw signals. One of the more popular methods involves the extraction of an appropriate set of features followed by the use of a neural network for the classification of the signals in the feature space. This paper describes an alternative approach which uses the least mean square (LMS) method and expectation maximization (EM) algorithm with the model based deconvolution which is employed for classifying nondestructive evaluation (NDE) signals from steam generator tubes in a nuclear power plant. The signals due to cracks and deposits are not significantly different. These signals must be discriminated to prevent from happening a huge disaster such as contamination of water or explosion. A model based deconvolution has been described to facilitate comparison of classification results. The method uses the space alternating generalized expectation maximization (SAGE) algorithm In conjunction with the Newton-Raphson method which uses the Hessian parameter resulting in fast convergence to estimate the time of flight and the distance between the tube wall and the ultrasonic sensor Results using these schemes for the classification of ultrasonic signals from cracks and deposits within steam generator tubes are presented and showed a reasonable performances.

• Journal of the Korean Society of Environmental Restoration Technology
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• v.15 no.3
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• pp.29-43
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• 2012

This study evaluated 23 botanic gardens and arboretums under two main categories including professional group and operational group. As for professional group, the main difference between the functions of botanic gardens and arboretums was analyzed. In the case of operational group compared professional group respectively, on categories including importance of function and implementation, seeking to provide fundamental data of botanic gardens and arboretums by enhancing the quality of visitors and examining functional differences. The result of a difference in arboretums' function between professional and operational groups, the study analyzed the importance of botanic gardens and arboretums in terms of detailed categories such as research, education, collection, display, retention, and service for visitors. As a result, professional group showed retention 4.32>education 4.11>research 4.09>service for visitors 4.05, and operational group showed retention 3.70>service 3.52>education 3.41>research 3.37, indicating that both groups had retention as the most selected answer. Looking closely at the functions of the currently implemented detailed categories of botanic gardens and arboretums, such as research, education, collection, display, retention, and service for visitors, the study showed that 91.3% selected rare species and individual multiplication for research function, 78.3% chose education of natural ecosystem for children for education, 73.9% answered space for experiencing nature for display, and 73.9% also replied managon, diof rare species, reproduction, and retention of native plants' species for retention category, and service for visitors showed 95.7% for implementation. The study could not clearly point out the influence between predictors due to absence of an established comprehensive evaluation model. Also, it analyzed and reviewed comparison of functions of professional group and operational group, but in the future, it should conduct study on a systemic and objective classification of botanic gardens and arboretums to clearly examine the difference in views between groups, which also requires, at the same time, study on management policy of botanic gardens and arboretums or suggesting guidelines that suit types of forms, and also study on facilities and program development that can be applied to each class.

• Journal of Radiation Protection and Research
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• v.38 no.4
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• pp.228-233
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• 2013

It has been continuously generated the requirement for the replacement of the main components such as a steam generator due to the deterioration of the nuclear power plant all around the world. Also, a large amount of radioactive metal was generated during the decommissioning in a short period. It is required to make an accurate measurement of the residual radioactivity for recycling the metal waste for releasing from regulatory control. In planning the measurement procedures, the influence of geometry, self-absorption, density and other relevant factors on the representativeness of the measurements should be considered for the decommissioning metal waste. In this study, the method for measurement procedures, the source term evaluation, the ways to secure representative samples, the measurement device for wide area and the self-absorption correction factors for different density were evaluated. The metal samples for measurement were prepared for securing the simple geometry and representative by melting process. The developed correction method for measuring the radioactivity a variety density of metal waste could improve the reliability of the evaluation results for clearance.