• Nuclear Engineering and Technology
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• v.52 no.1
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• pp.51-58
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• 2020

Despite the recent growth of interest in molten salt reactor technology and the crucial role which heat transfer plays in the design of power reactors, specific studies on the design of heat exchangers for the Molten Salt Fast Reactor have not yet been performed. In this work we deliver a preliminary but quantitative analysis of the intermediate heat exchangers, based on reference design data from the SAMOFAR H2020-Euratom project. Two different promising reference technologies are selected for study thanks to their compactness features, the Printed Circuit and the Helical Coil heat exchangers. We present preliminary design results for each technology, based on simplified design tools. Results highlight the limiting effects of the compactness constraints imposed on the fuel salt inventory and the allowed size. Large pressure drops on both flow sides are to be expected, with negative consequences on pumping power and natural circulation capabilities. The small size required for the flow channels also represents possible fabrication issues and safety concerns regarding channel blockage.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2011.04a
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• pp.193-195
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• 2011

An abrupt increase of duct cross-section is frequently encountered in pressure reducing devices, valves of internal combustion engines and in gas pipelines. Supersonic flow in a rectangular duct passing an abrupt increase of cross-section is studied numerically. The behavior of base pressure of the dead-air region at sudden enlargement of the duct is clarified. This investigation concerns the determination of the base pressure, which is independent of the size of the enlarged part. Several flow patterns are identified with different enlargements according to the ratio between the downstream ambient pressure and the upstream reservoir pressure. Base pressure and the resulting shock-structure are highly depending on the size of duct enlargement. For a given duct, base pressure tends to minimum for a particular pressure ratio. In addition, the locations of secondary separation and reattachment points of the jet plume are found with respect to different duct enlargements.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2005.06a
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• pp.2028-2031
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• 2005

This paper concerns stress distribution of the soft golf clubs using FEM. The identification of the stress distribution of the soft golf clubs used the finite element method using ABAQUS. The soft golf clubs which were designated is a new golf clubs to keep a good health for the elderly. To design the soft golf clubs, we concerns two main purpose ; First, our efforts concentrate to reduce the weight of the soft golf clubs. We considers the change of material and geometry of the golf club‘s head and shaft. Second, it is to increase the size and shape of 'sweet spot' of the soft golf club’s head face. To accomplish this purpose, we made the various type of the soft golf club's head. In this paper, we simulates putter models of the soft golf clubs. The pre-processing which generates the mesh of the model used HyperMesh with geometry data by CATIA ver 5.0 This paper compares the stress distribution of putter type which was loaded.

• Journal of the Korean Society of School Health
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• v.17 no.2
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• pp.23-34
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• 2004

Purpose: The purpose of this study was to investigate the prevalence fate of obesity and to assess the relationship between obese children and their family Characteristics in 3 rural area in the Chung Cheong Nam Do province. Method: The children's height, weight and family characteristics of 327 5th and 6th grade elementary school students were obtained from the individual health records and self-recorded questionnaire surveys from June 25th to July 15, 2004. Results: The results of this study are summarized as follows: 1. The prevalence rate of obesity of 5th and 6th grade of rural elementary school students was 10.5%. 2. 20.9% of obese children had obese family members and 9.4% of obese children did not have any obese family members. The birth order, family size and family structure showed no significantly difference. 3. The obese children were more affected by their parents' concerns of body image (upper quartile of 84.1) and exercise (upper quartile 61.4%) than normal children. However, there was no significantly increase with the parents' concerns about meals. 4. There was no relationship in the obese children by PBI. 5. There was no relationship in the obese children by FACES III. Conclusion: The elevation of a parent's concern of their obese child about meal regulation should be investigated further.

• Proceedings of the Korean Institute of Interior Design Conference
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• 2006.05a
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• pp.67-70
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• 2006

In modern society industrial structure is being altered in complex and various way owing to rapid technical development and economic development, and concerns and recognition for surrounding environment is being moth heightened. For this reason, modern people requite the environment which can be applied in more pleasant and convenient way, and in order to satisfy such requirements, importance of the interior design mote vividly stands out, and concerns or the society for the design is being more Heightened these days. Especially, as for the design of the office space, the study transforming the office, which is the rendezvous of the information, into the business environment with more comfortable and sensitivity, being free rrom the design concentrated on the business efficiency and economic feasibility, has been actively proceeded. As it is the reality that various and new types of the business spaces have appeared, new office landscape design is requited as the device to solve the matter related to the society change. It is purposed to propose the office space which is comfortable together with flowing sensitivity by applying the color plan that unconsciously controls the human sense through remodeling of mid size of the office space.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.11 no.6
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• pp.151-156
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• 2011

The Korean domestic cloud market will reach a value of 2 trillion Korean won by 2014. The domestic market is expected to grow rapidly in size despite the fact that there exist activation barriers in mobile cloud services, concerns about the reliability of service, and concerns about security and confidentiality of data. Under these circumstances, existing IT security technologies may be be utilized to provide sufficient response characteristics. Despite this, they must be optimized for mobile cloud computing and enhanced to mitigate inherent security flaws. In this study, mobile cloud security is covered along with use cases that cover the cases where mobile devices are particularly vulnerable and suggest ways to mitigate security vulnerabilities.

• Particle and aerosol research
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• v.9 no.3
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• pp.133-137
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• 2013

Measuring particle size distribution is one of the primary concerns in aerosol studies. For a nano-particle size distribution measurement, many scientists use a combination of a differential mobility analyzer (DMA) and a condensation particle counter (CPC) system, which is a called scanning mobility particle sizer (SMPS). Although it has a very high particle size resolution, some issues still remain. These problems include residence time between a DMA and a CPC, discontinuity of a CPC, and disturbance due to long scanning time during the precise measurement of particles. In particular, long scanning time is not adequate for measuring particle size distribution since the particle concentration is changing during the measurement. In this study, we developed radial exhaust multi-port system (REM-system) with no scanning time and high resolution to measure real-time particle size distribution. As a result of the REM-system performed using mono-disperse particle, it is expected that this system will be suitable for measuring continuously changing aerosol. If the counting efficiency of multi-condensation particle counter (M-CPC) and data inversion matrix are completed, REM-system will be a very adequate system for unsteady aerosol, which changes for SMPS scanning time.

• Journal of KIISE:Software and Applications
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• v.32 no.3
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• pp.227-235
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• 2005

In the embedded system domain, both memory requirement and energy consumption are great concerns. To save memory and energy, the 32 bit ARM processor supports the 16 bit Thumb instruction set. For a given program, the Thumb code is typically smaller than the ARM code. However, the limitations of the Thumb instruction set can often lead to generation of poorer quality code. To generate codes with smaller size but a little slower execution speed, Krishnaswarmy suggests a profiling guided selection algorithm at module level for generating mixed ARM and Thumb codes for application programs. The resulting codes of the algorithm give significant code size reductions with a little loss in performance. When the instruction set is selected at module level, some functions, which should be compiled in Thumb mode to reduce code size, are compiled to ARM code. It means we have additional code size reduction chance. In this paper, we propose a profile guided selection algorithm at function level for generating mixed ARM and Thumb codes for application programs so that the resulting codes give additional code size reductions without loss in performance compared to the module level algorithm. We can reduce 2.7％ code size additionally with no performance penalty

• Journal of ILASS-Korea
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• v.10 no.1
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• pp.43-52
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• 2005

The effect of fuel injection spray on engine performance has been known as one of the major concerns for improving fuel economy and reducing emissions. In general, reducing the spray droplet size could prevent HC emission in gasoline engine. As far as PFI (Port Fuel Injection) gasoline engine is concerned, the mixture of air and fuel may not be uniform under a certain condition, because breakup and production of spray droplets are made in a short distance between the fuel injector and intake valve. This study, by constituting PFI gasoline spray system, was performed to study the transient spray characteristics and dynamic behavior of droplets from 2hole 2spray type injector used in DOHC gasoline engine. Mean droplet size and optical concentration in accordance with various conditions were measured by LDPA and CCD camera. Through this study, the variation of drop size and optical concentration could be used for understanding the behavior of unsteady spray was declared and the existing the small droplets between each pulse spray could be estimated caused to the development of wall film was conformed.

• Journal of Fashion Business
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• v.18 no.2
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• pp.54-65
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• 2014

This study developed basic pattern for competition figure skating wear for school girls. Figure skating wears are difficult for making basic patterns based on standard size chart, because girls' body size are slimmer and more slender compared to the general girl's and the competition wears such as, swim suit with sleeves are, closely in contact with the player's body. The competition wears for school girl was made with consideration of changing of the body shape, physical exercises, and various specificities according to stretch material. To raise artistic effect while doing beautiful motions, and to assist in facile technique motions, competition wears need to have enough ease on the side line from waist to armpit, from armpit to wrist, and in trunk girth including crotch girth. Also, to stand out in beauty, a costume designing has a proper skirt position, length, flare width, and a tight bodice according to the player's body proportion. Most of the customers are displeased at the high price, unfitness of size, insufficient design, and difficulty in access, since they are not sold in sporting goods store. Therefore, a competition wear's basic pattern was made through scientific and emotional process including concerns on material properties, room for activities, and ideal body proportion. Systemizing the basic patterns of production method will solve high repairing expenses, unsuitable sizing, and improve accessibility for purchase.