• Journal of the Korean Society for Nondestructive Testing
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• v.22 no.4
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• pp.333-346
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• 2002

The continuous indentation techniques are one of the most effective methods to nondestructively estimate mechanical properties. There are many applications in various dimensions of materials from macro-scale, through micro-scale, even to nano-scale range. The macro-range technology of kgf-load level is now focused on the evaluation of tensile properties and residual stress of bulk materials, for example, used in conventional load-bearing structures and in-use pipelines. The technology and the apparatus were successfully developed by a domestic research group. The micro-range technology of gf-load level can be applied to investigate some property-gradient materials such as weldment. Because it has better spatial resolution than the macro-range technology. The nano-range technology (called nanoindentation technique) of mgf-load level is basically used to evaluate hardness and modulus of micro- and nano-materials. Moreover, many researches are going on to measure tensile properties and residual stress. The nanoindentation technology is easy to be applied to the various fields, such as semiconductor devices, multiphase materials, and biomaterials, though other methods are too difficult to be applied due to dimensional or environmental limitations. On the basis of these accomplishments, the international and the domestic standards are being established.

• Transactions of the Korean Society of Automotive Engineers
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• v.24 no.2
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• pp.242-254
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• 2016

This paper is the forth investigation on the evaluation methods of flow characteristics in a steady flow bench. In the previous works, it was concluded that the assumption of the solid rotation might cause serious problems and both of the eccentricity and the velocity profile distort the flow characteristics when using the ISM at 1.75B plane. Also particle image velocimetry (PIV) measurement at this position showed that the real velocity profile was far from the assumption of ISM evaluation. In this paper, the planar velocity profiles were measure from 1.75B to 6.00B position by PIV and the characteristics were examined according to the valve angles and lifts for further investigations about the effect of the position on the velocity profile. The results show that $26^{\circ}$ valve angle is always an unique exceptional case in all aspects. If the valve angle is $21^{\circ}$ and below, the planar velocity profiles according to the lift and the position are similar to each other, however, the tangential velocity curves along with the radial direction have common tendencies up to $16^{\circ}$ angle. Also the well arranged swirl behaviors are generally observed at the position above 3.00B and the velocity contour lines come closer to the concentric circle as the valve lift increases. In addition, the gradient of tangential velocity along with the radial direction from the swirl center becomes stable and constant as the position goes downstream. Concurrently the velocity gradient is larger to the eccentric direction of the center. In the meantime the tangential velocity curves along with the radial direction are irregular and various at 1.75B, however, they become regular and reach higher level as the evaluation position goes downstream. At this time the curves of 4.50B are the best fitted to the ideal one. On the other hand in an exceptional case, $26^{\circ}$, the velocity contours are very complicated over 6mm valve lift regardless the position and the gradient increases to the opposite direction of the eccentric center. Also, 6.00B is a best fitting position in the geometrical cylinder center base. With respect to the swirl center, the distribution range of centers for 1.75B is different to that for the other positions and the eccentricities of this plane are larger regardless the valve angle. After 1.75B, there is no certain tendency in the center position change according to the valve angle and lift. Additionally, the eccentricities are not sufficiently small to neglecting the effect on ISM measurement.

• Economic and Environmental Geology
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• v.52 no.1
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• pp.29-35
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• 2019

The purpose of this study was to assess the applicability of acid mine drainage sludge (AMDS) pellets for the arsenic (As) stabilization and to suggest an evaluation method for arsenic stabilization efficiency in soil around abandoned coal mines. The soil samples were collected from the agricultural field around Ham-Tae, Dong-Won, Dong-Hae, and Ok-Dong coal mine. The As concentration in soil was exceeding the criteria of soil pollution level, except for Ham-Tae coal mine. The AMDS pellets are more appropriate to use by reducing dust occurrence during the transport and application process than AMDS powder. In addition, AMDS pellets were maintained the As stabilization efficiency. The application of AMDS pellets for the As stabilization in soil was assessed by column experiments. The AMDS pellets were more effective than limestone and steel slag, which used as the conventional additives for the stabilization process. The As extraction by $0.43M\;HNO_3$ or $1M\;NaH_2PO_4$ solution were appropriate evaluation methods for evaluation of As stabilization efficiency in the soil.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.39 no.3
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• pp.100-108
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• 2016

The purpose of this study is to present a business strategy plan to increase organizational effectiveness of small and medium-sized enterprises. The research investigated in the level of human resource activity, such as recruitment, education, evaluation, compensation and development for the employees and executives who are working at small and medium-sized enterprises where located in Busan and Gyongnam province. With this, the research carried out actual proof analysis on the level of human resource activity effects on organization effectiveness like job satisfaction and organizational commitment. The following implications can be acquired from the result of multiple regression analysis on the 201 employees of small and medium enterprises. First, small and medium-sized enterprises should carry out human resource management activities and improve research and development capacity to enhance organization effectiveness. Second, in order to improve job satisfaction of the members of small and medium-sized enterprises, the management should concentrate on recruitment activity and reward maintenance management activity and come up with strategies to enhance learning ability and external network ability. Third, in order to enhance organizational commitment of the members of small and medium-sized enterprises, recruitment activity, training activity, and reward maintenance management activity should be carried out and the management should come up with strategies to enhance learning ability and external network ability. In this research, the objective was only to find out antecedents of organization effectiveness, but considering that causality might arise among the antecedents, in the studies hereafter, the verification on the structural relationship of various factors will be needed.

• Transactions of the Korean Society of Automotive Engineers
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• v.21 no.4
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• pp.135-143
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• 2013

In this study, we suggested effective countermeasure of biodiesel oxidation problems by investigating the oxidation degradation of biodiesels derived from variable resources and the level of oxidation stability of current distributing biodiesel blended fuels (2%) in Korea, and oxidation stability change according to storage time (for 3 month) and biodiesel blending ratio (2, 5, 7, 10%). By the composition analysis results of biodiesel from various resources which are possible to distribute in Korea, the biodiesel from animal fat has poor oxidation stability and cold performance, while the biodiesel from coconut and palm kernel which are considered as future potential raw material showed good oxidation stability and cold performance. The oxidation stability level of current distributing biodiesel blended fuels in Korea was excellent with showing over 30 hours (average 68 hours) stability, but the oxidation stability of the blended fuel with animal fat biodiesel having poor oxidation property (1.22 hours) was rapidly decreased to below 32 hours by mixing only 2%. Therefore, we have to pay attention to quality control of oxidation property, because the oxidation stability problem can be caused by increasing biodiesel blending ratio and diversifying raw materials those have worse property.

• Journal of the Korean Society of Food Culture
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• v.5 no.4
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• pp.425-430
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• 1990

The taste describing terms of Monosodium glutamate(MSG) was surveyed by questionnaires, and the sensory threshold value of MSG solution was compared to those of other basic taste substances. The effects of MSG addition to the other basic tastes were also evaluated. From the 96 responders, the taste of MSG itself was expressed as greasy(58%) or nauseous(24%), but the taste expected when MSG was added to food was expressed as sapidity and relish(79%). From the sensory evaluation, the panel expressed greasy, bitter or sweet at the absolute threshold level(0.002 M) of MSG solution, but changed to greasy and salty at the recognition threshold level(0.006 M). When MSG was added to salt solution, it expanded the salty taste, but with citric acid solution it suppressed the sourness. When MSG was added to sugar solution, it expanded sweet taste at the lower concentration of MSG(0.01 M), but suppressed the sweet taste as MSG concentration increased.

• Nuclear Engineering and Technology
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• v.52 no.11
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• pp.2652-2659
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• 2020

The methyl iodide (CH₃I) removal performance of tri-ethylene-di-amine impregnated activated carbon (TEDA-AC) used in the air cleaning unit of nuclear power plants (NPPs) should be maintained at least 99% between 24 month-performance test period. In order for evaluating the effectiveness of TEDA-AC on the removal performance of CH₃I in nuclear power plant during the operation of NPPs, the long-term test for up to 15 months was carried out under the simulated operating conditions (e.g., 25 ℃, RH 50%, ppb level poisoning gases injection) at nuclear power plants (NPPs). The TEDA-AC samples were analyzed with the Brunauer-Emmett-Teller (BET) specific surface area and TEDA content as well as CH₃I penetration test. It is clearly evident that more than 99% of CH₃I removal performance of TEDA-AC was observed in the TEDA-AC samples during 15 months of long-term operation under the simulated NPP operating conditions including the ppb level of organic and oxide form of poisoning gases. BET specific surface area and TEDA content that can affect the CH₃I removal performance of TEDA-AC were also maintained as those in new TEDA-AC during 15 months of long-term operation.

• Ocean and Polar Research
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• v.40 no.4
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• pp.223-235
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• 2018

This study was carried out to investigate benthic sedimentary environments and benthic polychaetous communities on the coast of Ulsan, located on the southern East Sea of Korea. This survey was conducted at 15 stations, four times seasonally in January, April, July and October 2016. From the coast to the outer sea, surface sediments turned into fine grained sediments. There were complex coarse-grained sedimentary facies in various forms in the coastal zones while those with mud facies were found in the offshore zone. Organic matter content (LOI) and sulfide amount (AVS) recorded extremely high values, and increased from the coast to the outer sea, showing a similar trend to mud content with depth. The benthic polychaetous community revealed a mean density of $525ind./m^2$, and the total species number of species was 84. The major dominant polychaetous species were Magelona japonica, Lumbrineris longifolia and Heteromastus filiformis throughout the four seasons. Magelona japonica was concentrated predominantly in shallow coastal areas, but was present in all the regions of the survey area. Lumbrineris longifolia showed higher density in offshore regions more than 30 m deep, whereas H. filiformis showed higher density in coastal areas less than 30 m in depth. As a result of cluster analysis, the study area was divided into three ecological areas according to species composition, such as the northern coastal area between Ulsan PortOnsan Port, the southern area around Hoeya River and the outer sea area. Benthic environments in the study area, as determined by AMBI and BPI index, maintained a healthy condition in all four seasons with the AMBI at a level above GOOD and BPI at a level above FAIR. As organic matter accumulation continues to take place in the Ulsan coastal area, it is essential that detailed research activities continue to be carried out and ongoing monitoring be maintained.

• Journal of Korean Institute of Architectural Sustainable Environment and Building Systems
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• v.12 no.6
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• pp.655-668
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• 2018

This paper analyzes the applicability and technology level of the green building element technology by analyzing the scorecard of the LEED Canada certified buildings. The results of this analysis will be able to evaluate the current status and level of application of green building element technology, and it will be used as a basic data to prepare for the revision of the certification standards and the establishment of strategies for the future green building activation. In this study, 1,010 LEED Canada certified buildings from 2011 to 2016 were analyzed. The results were analyzed by focusing on the status of greening by certification category and the characteristics of adoption by sub-category. The results of the study are summarized as follows. (1) EA category showed the biggest difference between the certification scores and the adoption rates than other categories, and it was confirmed that it is not easy category from the viewpoint of practical adoption. On the other hand, the ID (Innovation & Design Process) and WE were analyzed to be relatively easy to apply, with a score of over 72%. (2) In the case of Platinum class, the upper adoption rate is shown in all categories except MR. The Gold class shows the adoption rate of WE and ID in the top, and the middle rate in most categories. Silver grades showed lower rates in the three categories except WE, ID and EQ. Certified grades showed the adoption rates of the bottom except the two categories.

• Animal Bioscience
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• v.35 no.10
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• pp.1592-1605
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• 2022

Objective: The objective of this study was to select an effective in vitro digestion-fermentation model to estimate the effect of decreasing dietary crude protein (CP) on odor emission during pig production and to suggest potential prediction markers through in vitro and in vivo experiments. Methods: In the in vitro experiment, three diet formulations with different CP contents (170 g/kg, 150 g/kg, and 130 g/kg) but containing the same standardized ileal digestible essential amino acids (SID-EAA) were assessed. Each diet was evaluated by two different in vitro gastric-intestinal phase digestion methods (flask and dialysis), combined with fresh pig feces-ferment inoculation. Eighteen growing barrows (31.9±1.6 kg) were divided into three groups: control diet (180 g CP/kg, without SID-EAA adjustment), 170 g CP/kg diet, and 150 g CP/kg diet for 4 weeks. Results: The in vitro digestion results indicated that in vitro digestibility was affected by the gastric-intestinal phase digestion method and dietary CP level. According to the gas kinetic and digestibility results, the dialysis method showed greater distinguishability for dietary CP level adjustment. Nitrogen-related odor compounds (NH₃-N, indole, p-cresol, and skatole) were highly correlated with urease and protease activity. The feeding study indicated that both EAA-adjusted diets resulted in a lower odor emission especially in p-cresol and skatole. Both protease and urease activity in feces were also closely related to odor emissions from nitrogen metabolism compounds. Conclusion: Dialysis digestion in the gastric-intestinal phase followed by fresh fecal inoculation fermentation is suitable for in vitro diet evaluation. The enzyme activity in the fermentation and the fecal samples might provide a simple and effective estimation tool for nitrogen-related odor emission prediction in both in vitro and in vivo experiments.