• Journal of Korean Society of Water and Wastewater
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• v.23 no.4
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• pp.417-430
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• 2009

A BNR comprehensive performance evaluation (BNR CPE) system was established employing system-oriented evaluation methodology for biological nutrient removal (BNR) processes based on the CPE techniques developed by U.S. EPA for evaluation of conventional biological processes. The BNR CPE system applied to five domestic BNR plants adopting $A^2/O$ process confirmed that all target plants except the smallest one had not any serious defective performance and process stability was enhanced with increasing plant size. The system also clearly verified relatively poor performances in anoxic reactors without exception mainly due to influent carbon limit rather than functional defect. Consistent good performances were confirmed even during both winter season and wet weather generally known to be difficult to achieve satisfactory removals. Presentation of evaluation results by modified radar chart system simplified and clarified the evaluation and analysis procedures. The BNR CPE system could not only discover readily the causes of present and prospective poor performances but also facilitate the suggestion of their optimization options. Mutual effect and cause-and-effect among operation parameters and unit processes were also found easily using the evaluation system. The system justified that the adverse effect of defective operating parameters could be compensated by other favorable parameters, especially in anaerobic and anoxic reactors as well as during the winter season.

• Korean Journal of Microbiology
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• v.52 no.3
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• pp.375-379
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• 2016

In this study, the structure and diversity of bacterial community were investigated in the surface and subsurface marine sediments using a NGS method (i.e. illumina sequencing technology). The bacterial community in the surface was distinct from that in the subsurface of marine sediment; with the exception of the phylum Proteobacteria, the relative abundance of Bacteroides phylum were higher in the surface than subsurface, whereas the sequences affiliated to the phyla Chloroflexi and Acidobacteria were relatively more copious in the subsurface than surface sediment. Moreover, interestingly, we observed that the phyla Nitrospinae and Nitrospirae contribute to nitrogen cycle in the marine sediment. This study may present the possibility for the presence of novel microorganisms as unexplored sources and provide basic information on the microbial community structure.

• Journal of Animal Environmental Science
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• v.20 no.1
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• pp.21-26
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• 2014

The goal of this study was to investigate acoustic characteristic of feed anticipating calls of heifers and cows. 6 cows and 6 heifers housed in a pen ($6.0m{\times}10.0m$) which was bedded with sawdust and straw. They were fed a standard ration of commercial concentrate and hay was ad libitum. The calls of heifers and cows were divided into Type 1 and Type 2 which were classified based on the shapes of waveform and spectrograms, respectively. There was difference in the fundamental frequency (P < 0.0001) and $1^{st}$ formant (P < 0.0077) among the calls. Acoustic parameters with the exception of fundamental frequency and $1^{st}$ formant were no difference between cows' calls and heifers' calls (P > 0.05). Duration of cows' calls was lower than that of heifers' calls, whereas the intensity of Type 1 calls was higher than that of Type 2 calls (P > 0.05).

• Journal of Korean Society of Disaster and Security
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• v.7 no.1
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• pp.43-50
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• 2014

Based on the reliability theory, the risk assessment of steel beams is performed by the determination of failure probability. In the calculation, bending, shearing and combined (bending + shearing) modes are examined. The resistance and the loads on the beam are assumed to be normal distribution. To investigate the failure probability changes, total load applied at the mid span of beam is divided into 1 to 1 and 1 to 2 ratio and then these divided loads are placed on the trisected points on beam. The change of boundary conditions at beam ends are also included in the investigation. It shows that failure is governed by the combined mode for the present beams and the second order bound analysis of failure probability is not crucial. On the whole failure probability decreases with increasing end restraints at the beam ends with some exception.

• Journal of the Korea Furniture Society
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• v.25 no.3
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• pp.173-181
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• 2014

Since the onset of the 21st century, digital technology has been widely adopted in various fields of art; it has enabled artists or designers to try diverse and brand-new ways of expression in literally every possible field of art, including painting, sculpture, and other design work. Furniture design is no exception. From the initial design step to the final production of furniture, modern digital skills are broadly utilized, creating a whole new set of designs that would otherwise be hardly conceivable and realizing a highly efficient furniture-making mechanism. More recently, the 3D printing technique, which is called a 21st century alchemy, has been successfully commercialized and is getting more popular, heralding yet another innovative shift in the area of furniture design and production. In this context, this study discusses the background of the furniture design using digital technology, and identifies the correlations between the modern digital technology and furniture design by redefining the concept of such digital technology. By reviewing multiple real-life cases, some of the key digital expressions found in modern furniture design are also analyzed. This study aims at suggesting the reason why digital technology is significant and promising in diverse ways for the development of modern furniture design.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.22 no.1
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• pp.1-8
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• 1989

Demersal fish community in Cheonsu Bay was analyzed using fish samples collected by a small otter trawl from March to November, 1986. Of the 32 species identified, Nibea argentatus, Chaturichthys stigmatias Crptocentrus filifer, Cynoglossus joyneri and Jonius belengeri pre-dominated in abundance. Based upon principal component analysis of species composition data, the fishes were grouped into resident, migrant and temporal species. Resident fish wintered in the deeper part of the bay, showing a peak in biomass during cold months. In spring, warm weather seasonals, adult N. argentatus and J. belengeri, migrated o the bay for spawing. However, the biomass of the migrant was not more than that of the wintered adult residents. From July to September, juveniles of many species were collected, but the number of individuals was smaller than that of the littoral or pelagic zones. This suggests that the deeper area of the bay did not serve as a main nursery ground of the juveniles with the exception of two migrant scianid fishes. As a result, the benthic fish of the bay were more abundant in cold months than in summer.

• Journal of the Korean Home Economics Association
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• v.45 no.9
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• pp.63-74
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• 2007

The purpose of this study was to investigate types of well-being oriented consumption values that lead to well-being food consumption behaviors, as well as to identify the variables influence well-being food consumption. A survey of 579 women aged 20 or more was conducted through azoomma.com, an online portal site. The findings of the study were as follows: The level of well-being food consumption was above the mid-value for all categories, with the exception of food with added ingredients. In addttion, multiple regression analysis indicated that approximately 22.7% of the environmentally friendly foods consumed were chosen based on emotional value, degree of price perception and educational level. Conversely, 20.8% of the confectionaeries consumed were chosen based on emotional value, age, degree of price perception, average monthly income, and functional value. When food with added ingredients were considered 16.6% of those were chosen based on emotional value, social value, and degree of price perception. Finally, 29.3% of cereals and fish consumed were chosen based on emotional value, degree of family's health, and social value.

• Journal of Convergence Society for SMB
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• v.4 no.2
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• pp.25-31
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• 2014

Sliding mode design and analysis for nonlinear system was carried out. A designer will determine the parameters to know about the performance and robustness of the system dynamics. To investigate the characteristics of sliding mode control, an inverted pendulum model is applied by the sliding mode control and the state concerned is output. Comparison is made by evaluating different initial conditions, sliding numerical components for sliding surface, and input gain, the dynamic of output will be investigated to conclude the generality. Control approaches have their limitations and sliding mode control is no exception. The chattering problem is its main negative effect to overcome. This effect is displayed and in this project chattering problem is suppressed by a modified discontinuous controller.

• Journal of Digital Convergence
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• v.7 no.3
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• pp.61-74
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• 2009

This research reviewed previous research related to Performance Measurement Models of Knowledge Management (PMMKM) in order to integrate their findings with more recent research and construct a new PMMKM. This new hypothetical PMMKM consists of an input sector, a process sector, an outcome sector, and an infrastructure sector. Each sector has three measurement items with the exception of the infrastructure sector which has two. Empirical analyses testing the overall performance model validity of the hypothetical PMMKM were favorable. However, it show be noted that the "share process" and "utilization process" items in the process sector merged into one single item. The same is true with the "individual outcome" and "organization outcome" items in the outcome sector found one single item. The study's results reveal three implications with respect to performance. First, there are derived integrated performance measurement sectors and items based on overall management process of knowledge management, which can be practically applied to the government related research entities. This became apparent after extensive review or previous theoretical studies related to the public sector and private sector. Second, weighted performance measurement of knowledge management using AHP (Analytic Hierarchy Process) Analysis makes it possible to propose PMMKM in government sponsored research institutes. Finally, measuring performance to management knowledge, as shown in this study, will prove useful for inside and outside experts who propose specific guidelines and methodologies for Knowledge management at government sponsored research institutes.

• Journal of Power System Engineering
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• v.20 no.5
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• pp.78-85
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• 2016

This paper considers the influence of internal heat exchangers to the efficiency of a refrigerating system using R170. These liquid-gas heat exchangers(internal or suction-line heat exchangers) can, in some cases, yield improved system performance while in other cases they degrade system performance. A steady state mathematical model is used to analysis the performance characteristics of refrigeration system with internal heat exchanger. The influence of operating conditions, such as the mass flowrate of R170, inner diameter tube and length of internal heat exchanger, to optimal dimensions of the heat exchanger is also analyzed in the paper. The main results were summarized as follows : the mass flowrate of R170, inner diameter tube and length of internal heat exchanger, and effectiveness have an effect on the cooling capacity, compressor work and RCI(Relative Capacity Index) of this system. Exception for the effect of inner diameter, the RCI of R170 with respect to refrigerant mass flowrate, the length and effectiveness of internal heat exchanger is about 2.1~3.3% higher than that of R13 at the same experimental conditions. With a thorough grasp of these effect, it is necessary to design the R170 compression refrigeration cycle using internal heat exchanger.