• Journal of the Korea Academia-Industrial cooperation Society
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• v.17 no.3
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• pp.338-351
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• 2016

Park planning is done in a way to satisfy various expectations, including providing green space and offering urban space with specific and detailed strategies. This study focuses on large-scale parks that have been built since 2000 or that are going to be built. Their significance in the city was analyzed along with strategic characteristics for designing urban parks, and implications are suggested. First, the design aspects of urban parks have gradually tended towards flexibility for adapting to the diverse surrounding environments. Relating the parks to the surrounding area is realized through connection with facilities or planning to process the border area smoothly. Second, unlike in the past, urban parks are not just simply used as a resting space but play other productive and complex roles in the urban space for healing in the community. Third, six design strategies are being applied in these parks through mutually complex relations. Relations with external parties and planning inside the parks add more importance to the park for the community. Fourth, the changes of vertical time are reflected in park planning strategies and tend to form a floor plan. This is associated with growing park planning and is being realized as a major characteristic in urban park planning strategies.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.41 no.10
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• pp.649-657
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• 2017

A rupture in a high-pressure pipe causes the fluid in the pipe to be discharged in the atmosphere at a high speed resulting in a supersonic jet that generates the compressible flow. This supersonic jet may display complicated and unsteady behavior in general. In this study, Computational Fluid Dynamics (CFD) analysis was performed to investigate the compressible flow generated by a supersonic jet ejected from a high-pressure pipe. A Shear Stress Transport (SST) turbulence model was selected to analyze the unsteady nature of the flow, which depends upon the various gases as well as the diameter of the pipe. In the CFD analysis, the basic boundary conditions were assumed to be as follows: pipe of diameter 10 cm, jet pressure ratio of 5, and an inlet gas temperature of 300 K. During the analysis, the behavior of the shockwave generated by a supersonic jet was observed and it was found that the blast wave was generated indirectly. The pressure wave characteristics of hydrogen gas, which possesses the smallest molecular mass, showed the shortest distance to the safety zone. There were no significant difference observed for nitrogen gas, air, and oxygen gas, which have similar molecular mass. In addition, an increase in the diameter of the pipe resulted in the ejected impact caused by the increased flow rate to become larger and the zone of jet influence to extend further.

• Journal of Energy Engineering
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• v.20 no.3
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• pp.191-199
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• 2011

The char burn-out and NOx emissions from sub-bituminous coal were investigated in drop tube furnace under $O_2/N_2$ and $O_2/CO_2$ environments with different $O_2$ concentrations of 12, 21 and 31%. Results show that the char burn-out rate is faster as $O_2$ concentration increases higher and char burn-out rate under $O_2/CO_2$ decreases due to the lower oxygen diffusion into coal surface through the $CO_2$ rich boundary layer. NO concentration increases with increasing $O_2$ concentration, but declines at $O_2$ concentration of 31%. Meanwhile, NO emission indexes decreases monotonically with increasing $O_2$ concentration, which indicates that more NO reduction occurs with higher $O_2$ concentration probably due to greater HCN formation. For all conditions of $O_2$ concentration, the NO concentration under $O_2/N_2$ maintains higher than those of $O_2/CO_2$ due to presence of thermal NO.

• The Journal of the Korea Contents Association
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• v.18 no.8
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• pp.536-543
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• 2018

In 2003, the local police system was adopted, and the personnel and installation of local police agencies were subsequently changed. According to the "Police Law", local police station shall be established under the control of chief of police department, and the criteria for the installation of local police stations were to take into consideration of population, administrative districts, area, geographical characteristics, traffic and other conditions. The chief of local police has the authority to install district police station according to the "National Police Agency and its Organization". However, it is hard to say they were applied. Futhermore, it is inappropriate to apply the laws and regulations equally across the nation. Also, it has been criticized for its difficulties of patrolling, the weakened relationship with local residents, and poor quality of security services in rural areas. Therefore, this study suggests that the criteria for the installation of the police station should be made through a comprehensive analysis of the characteristics of the areas and security needs.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.21 no.5
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• pp.28-38
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• 2020

Semiconductor deposition equipment is an important example of Complex Products and Systems (CoPS) and requires in-depth understanding of user requirements. For this reason, we analyzed and compared users' and producers' perspectives on the quality attributes of semiconductor deposition equipment using the Kano model. The results show that the patterns of users' perspectives were different from those of producers. Out of 22 level-2 quality attributes, producers evaluated all 22 attributes as attractive qualities, but users evaluated only 6 as "attractive," 10 as "indifferent," 2 as "must have," and 4 as "other." Although all quality attributes were attractive for producers, only those related to reliability were attractive or must-have qualities, and all others were "indifferent." This result implies that the perspectives on quality attributes may be different between users and producers, and producers should revise their perspectives and strategies. In addition, the results support the characteristics of CoPS suggested by literature implying that performance is more important than economies of scale and cost reduction. It is suggested that producers of semiconductor deposition equipment strategize their approaches to users by considering the characteristics of CoPS.

• Food Science and Preservation
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• v.13 no.3
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• pp.382-388
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• 2006

Physicochemical properties of chufa starch were investigated The result are summarized as follow: Moisture content crude protein and crude fat were 10.10%, 0.31% and 0.41,% respectively. Amylose content of chufa starch was 41.6% and blue value was 0.49. Lightness and whiteness of chufa starch was 96.36 and 92.23 of Hunter's color value. In iodine reaction, maximum absorbance wavelength (${\lambda}max$) was 628 nm. Water binding capacity was 83% and swelling power and solubility of chufa starch were increased slowly to $60^{\circ}C$, but increased rapidly after $60^{\circ}C$. Scanning election microscope(SEM) showed that granule type of chufa starch was round or elliptic type, and average granule size was $10{\mu}m$. The results by differential scanning calorimetry(DSC) revealed that gelatinization patterns were similar to those of potato or rice starch. In rapid viscoanalyzer(RVA) examination, pasting temperature was $79.95^{\circ}C$ and peak viscosity of chufa starch was 385.08.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2000.05a
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• pp.410-418
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• 2000

In general, the experienced diver go into the water to find out Pan Shell which is spontaneously generated and brought up at the depth of 25-30 meters in the slime along the bank of an inlet of western and southern sea. However, this searching system has caused some problems in terms of economical efficiency and riskiness of diver. To overcome such problems and enhance the competence capability of fishermen, a new Pan Shell searching system is required. If an onboard searching system as a substitute of the way of diving into the deep water to identify the existence of Pan Shell is developed, it would be greatly beneficial to fishermen. The purpose of this research is to develop a new searching system of Pan Shell by making use of 50-200 Khz Ultra Sonic Signal, A/D Converter and computer process program. Based on the fact that Sonic Signal between the soft part of slime and the hard part of sand, pebble and Pan Shell is different, the possibility of this system have been approved in some degree by this time of research. However, to utilize this new system, further research on the establishment of data base and sample data is required. With the theoretical knowledge, the systematic research on the searching capability of Ultra Sonic Signal will be continued to identify the influence against the sea water subject. In this research, signal will be analyzed according to the influence range, power and sensitiveness of Ultra Sonic Generator. In addition, the radius of Ultra Sonic Signal will be included. The experimental field work will be executed at Nockdong, Pulkyo and other places well known as a habitat of Pan Shell.

• Journal of The Korean Association For Science Education
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• v.40 no.1
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• pp.13-28
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• 2020

This study attempted to understand the characteristics of images of scientific experiments represented and consumed on YouTube, a representative of today's new media. In particular, this paper analyzes the case studies of YouTube's hydrogen peroxide decomposition experiment based on Baudrillard's theory of Simulation and Simulacra, which discusses the strong status of images and the ambiguity of the boundary between virtual and reality. A total of 14 YouTube videos related to hydrogen peroxide decomposition experiments were analyzed. In those videos, hydrogen peroxide decomposition experiments were typically conducted with several signs representing scientific experiments, but the most important sign in the videos were bubbles produced through experiments. For more public consumption of the content, the bubbles resulted from hydrogen peroxide decomposition reproduced in YouTube have been transformed into a more spectacular image as 'super-huge' and 'explosive' bubble. Considering the influence of new media that can be accessed by students anytime and anywhere, it is positive that science experiments in new media enhance students' intimacy and access to science. At the same time, however, it is also important to note the danger that the purpose of scientific experiments will be limited to only 'showing specular images', due to the nature of new media, which mainly deals with immediate and superficial images. Furthermore, this study argues that improving students' science media literacy is required to critically examine the science-related images represented in the new media based on understanding the characteristics and limitations of new media that deeply affect daily life.

• Journal of the Korean Crystal Growth and Crystal Technology
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• v.19 no.5
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• pp.228-236
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• 2009

In this study, we investigated morphological characteristics of $SF_6$ clathrate hydrate crystals to understand its formation and growth mechanism. $SF_6$ clathrate hydrate crystals were formed in high-pressure reaction cell charged with pure water and $SF_6$ gas at constant pressure and temperature. Two-phase ($SF_6$ gas/aqueous solution) and three-phase ($SF_6$ gas/aqueous solution/$SF_6$ liquid) conditions were investigated, In both conditions, dendritic shape hydrate crystals were grown as like fibriform crystals along upward growth direction at the gas/aqueous solution interface. In the case of the reaction process of three-phase condition, when the $SF_6$ gas bubbles which were generated in $SF_6$ liquid phase due to the reduction of reaction cell pressure stuck to the gas/aqueous interfaces, the hydrate phase were appeared at the surface of the bubbles. This paper presents the detail growth characteristics of $SF_6$ hydrate crystals including crystal nucleation, migration, growth and interference.

• 한국데이터정보과학회:학술대회논문집
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• 2006.04a
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• pp.267-278
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• 2006

The purpose of this research is to identify differences between characteristics of purchase behavior of outdoor wear consumers, demographic variables and mountain climbing related variables. The subjects of surveys are selected among men and women consumers having experiences of purchasing outdoor wear in ages from 20's to over 50's who live in the vicinity of Busan. Data and information collected are analyzed by using SPSS Program. Results from the analysis of purchasing purpose indicates that they buy outdoor wear conducive to two similar reasons; that is, "only to exercise and enjoy mountain climbing" and "either to wear it in time of climbing mountain or everyday life," and results from the analysis of purchase frequency reveals that '$1\sim2$ times'a you is the highest. Results from analysis of preference of brand of outdoor wear reveals that Kolon Sport is followed by the North Face and K2.