• Journal of the Korean Magnetic Resonance Society
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• v.1 no.1
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• pp.7-20
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• 1997

The mapping of the spin-spin relaxation time T2 in pixed-by-pixel was suggested as a quantitative diagnostic tool in medicine. Although the CPMG pulse sequence has been known to be the best pulse sequence for T2 measurement in physics NMR, the supplied pulse sequence by the manufacture of MRI system was able to obtain the maximum of 4 CPMG images. Eight or more images with different echo time TEs are required to construct a reliable T2 map, so that two or more acquisitions were required, which easily took more than 10 minutes. 4-echo CPMG imaging pulse sequence was modified to generate the maximum of 8 MR images with evenly spaced echo time TEs. In human MR imaging, since patients tend to move at least several pixels between the different acquisitions, 8-echo CPMG imaging sequence reduces the acquisition time and may remove any misregistration of each pixel's signal for the fitting T2. The resultant T2 maps using the theoretically simulated images and using the MR images of the human brain suggested that 8 echo CPMG sequence with short echo spacing such as 17∼20 msec can give the reliable T2 map.

• Journal of Positioning, Navigation, and Timing
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• v.9 no.4
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• pp.337-345
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• 2020

In this paper, an efficient signal tracking method to simultaneously track both GPS L1 C/A and Galileo E1B CBOC(6,1,1/11) using a low cost GPU is proposed. In the existing method that each GNSS signal is processed within 1 ms, more than 2 ms processing time is required in GPU to process 4 ms CBOC signal. It means that real time operation is possible if only Galileo E1B CBOC signal is concerned. But when both GPS C/A and Galileo CBOC is required, it cannot process GPS C/A signal in real time. To process 1 ms GPS C/A and 4 ms Galileo CBOC signal in real time, 4 ms Galileo CBOC signal is divided into 4 by 1 ms signal block in the proposed method. Specially, a buffer that simultaneously manages 1 ms and 4 ms signals is designed. In addition, a module that accumulates the 1 ms correlation value of the Galileo CBOC by 4 ms and passes it to the PLL and DLL is implemented. The operation and performance are evaluated with real measurements in the GPU based SDR. The experimental results show that tracking of more than 16 satellites of GPS C/A and Galileo E1B is possible using the proposed method.

• Journal of KIBIM
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• v.11 no.2
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• pp.24-32
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• 2021

Recently, starting with smart construction research, interest in technology that automates construction site management using artificial intelligence technology is increasing. In order to automate construction site management, it is necessary to recognize objects such as construction equipment or workers, and automatically analyze the relationship between them. For example, if the relationship between workers and construction equipment at a construction site can be known, various use cases of site management such as work productivity, equipment operation status monitoring, and safety management can be implemented. This study derives a real-time object detection platform architecture that is required when performing construction site management using deep learning technology, which has recently been increasingly used. To this end, deep learning models that support real-time object detection are investigated and analyzed. Based on this, a deep learning model development process required for real-time construction site object detection is defined. Based on the defined process, a prototype that learns and detects construction site objects is developed, and then platform development considerations and architecture are derived from the results.

• International Journal of Internet, Broadcasting and Communication
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• v.16 no.2
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• pp.255-266
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• 2024

The purpose is to evaluate evacuation safety by simulating the toxic effects of hydrogen fluoride leaks in areas surrounding national industrial complexes and to suggest alternatives for areas that do not satisfy evacuation safety. For human casualties caused by hydrogen fluoride leakage accidents, Available Safe Egress Time (ASET) is calculated by the toxic effects quantified with the Areal Locations of Hazardous Atmospheres (ALOHA), an off-site consequence assessment program. The Required Safe Egress Time (RSET) is calculated through Pathfinder, an evacuation simulation program. Evacuation safety is assessed by comparing ASET and RSET. The ALOHA program was used to evaluate the time to reach AEGL-2 concentration in 12 scenarios. The Pathfinder program was used to assess the total evacuation time of the high school among specific fire-fighting objects. Of the 12 accident scenarios, ASET was larger than RSET in the worst-case scenarios 1 and 9. For the remaining 10 accident scenarios, the ASET is smaller than the RSET, so we found that evacuation safety is not guaranteed, and countermeasures are required. Since evacuation safety is not satisfactory, we proposed to set up an evacuation area equipped with positive pressure equipment and air respirators inside specific fire-fighting objects such as the high school.

• Journal of the Ergonomics Society of Korea
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• v.31 no.1
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• pp.7-13
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• 2012

Objective: This paper discussed the characteristics of service design process by comparing with product design process. Background: Service design has different design outcomes, project participants, and design constraints than product design. Method: The comparison took two perspectives: one was shorter-term, design process of a service, and the other was longer-term, process of service development. Results: It was discussed that service design process is similar in overall, but has four differences. First, the role of design is required earlier and longer in the process, which means service designers need to participate from the begging of the project to service operation. Thus service designers are required to have holistic viewpoint of the project. Second, service design requires many design expertise thus collaboration needs to be well defined and managed throughout the process. Third, since service provider has limited resources, regulations, and market competition, some service features cannot be provided. Service designers are required to know both customers' needs and functional constraints. Last, service design is highly coupled with service operation. Designing and providing service happens at the same time and evolves over time. Conclusion: Consequently it was asserted that the role of designers in service design is essential for success. In specific, the role of service design architect, who manages design process and design outcomes, is a new and important role in service design project.

• Human Ecology Research
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• v.55 no.5
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• pp.555-566
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• 2017

This study analyzes the practical tasks and required competency for technical designers to provide basic data on the training of domestic technical designers. The survey was applied to 21 technical designers of big vendors as well as investigated tasks, task flow, important tasks, time-consuming tasks, and required competencies. The results of the study are as follows. First, the technical designers were in charge of several brands of buyers and distributors of fashion companies, or several lines of the same brand. The main production items were cut and sewn knits. Second, the flow of task and tasks were in the order of buyer comments analysis, sloper decision to matching style, sewing specification, productive sewing method research, size specification suggestion, pattern correction comments, construction decision to matching style & fabric, sample evaluations, fit approval, business e-mail writing, specification & grading confirmation, and communication with buyer. Third, five tasks (analysis of buyer comments analysis, communication with buyer, pattern correction comments, productive sewing methods research, sample evaluation) were important and time-consuming tasks. Fourth, reeducation was required in order of sewing, pattern, English, fabric, and fitting. Fifth, competencies to be a technical designers were fitting, pattern correction, size specification & grading, construction & sewing specification, sewing terms & techniques, and communication skills. In conclusion, technical designer training should focus on technology-based instruction, such as sample evaluation, fitting, pattern correction, and productive sewing methods research of cut and sewn knits.

• Journal of Dairy Science and Biotechnology
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• v.21 no.2
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• pp.88-96
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• 2003

Cheese flavor is derived from three main pathways, that are proteolysis, lipolysis and glycolysis, the extent of which varies according to the cheese variety. Proteolysis is the most complex of the three primary events during cheese ripening. The basis of EMC technology is the use of specific enzymes acting at optimum conditions to produce required cheese flavors from suitable substrates. These enzymes consist of proteinases, peptidases, lipases, esterases. The key factors in EMC production are the type of cheese flavor required, the type and specificity of enzyme or cultures used, their concentration and some processing parameters, such as pH, temperature, agitation, aeration, and incubation time. The emulsifiers, bacteriocins, flavor compounds, and precursors also effect to it importantly. The dosage of enzyme or starter culture used is dependent on the intensity of flavor required, processing time and temperature and the quality of the initial substrate. To produce a consistent EMC product it is necessary to have a highly controlled process, and a detailed knowledge of the enzymatic reactions under the conditions used must be fully understood.

• Journal of the Earthquake Engineering Society of Korea
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• v.26 no.2
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• pp.59-69
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• 2022

The use of dampers is being considered a means to improve the seismic performance of buildings. It may take considerable time and effort to find an optimal design solution since repeated three-dimensional nonlinear time history analyses are required. Therefore, a preliminary design procedure for seismic retrofit using hysteretic dampers was proposed in this study. In the proposed procedure, the amount of retrofit (required number of dampers) is estimated from the capacity curve of the building before retrofit and allowable story drift of the building. In combining the capacity curves of the building and the dampers, the deformation demand for the dampers can be easily checked against their deformation capacity. The equations to transform the device displacement to roof displacement for the combination of capacity curves are developed. The proposed procedure was applied to the seismic retrofit design of sample buildings. The study found that the estimated capacity curve was very close to the actual capacity curve obtained from the pushover analysis, which can determine an appropriate configuration to meet the required seismic performance.

• Fashion & Textile Research Journal
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• v.16 no.6
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• pp.979-986
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• 2014

This study establishes basic data for operations management by organizing processes and measuring time in the mini line for female jackets to improve productivity, ensure competitiveness, and maintain operator competency and the line process flow balance between apparel manufacturing companies. The results of this study are as follows. Sewing operations are divided into preparation functions, arrangement, partial tasks, and assembly that consist of 84 processes. The results from time measurement indicate that 3238.41seconds (sec) were required to produce a single jacket and that the average time required for operators was 231.32 sec. A control limit was established to increase the reliability of the measured value for net time. After outside values were removed, the operation time was measured to be 3176.35 sec. This accounted for 98.08% of the total operation time, with net time decreasing by 62.06. Skill and effort level coefficients were applied to measure the operator performance, the total real time was calculated to be 3415. The requirement for preparation and arrangement operations were 1233.35 sec, and 2182.22 sec for partial tasks and assembly operations. Process separation and organization were performed after the bottleneck operation was selected to identify the maximum line balance. Consequently, process efficiency of preparation and arrangement operations increased from 79.19% to 93.00%, and the partial tasks and assembly operations increased from 62.36% to 90.93%.

• Proceedings of the Korean Society of Surveying, Geodesy, Photogrammetry, and Cartography Conference
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• 2004.04a
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• pp.45-49
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• 2004

The Navstar Global Positioning System(GPS) is an advanced navigation satelite system for determination of position, velocity and time. It can provide three-dimensional positioning on a global basis, independent of weather, 24 hours per day. Test results show that the carrier phase and pseudorange corrections are suitable for a kinematic GPS system. Using these corrections are more effective than using raw GPS data, since fewer bits are required for transmission Additionally, the number of computation required at the rover is reduced when corrections, rather than raw measurement are transmitted