• Fire Science and Engineering
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• v.33 no.1
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• pp.39-44
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• 2019

In this study, the relationships between the material properties of the wall and the fuel mass flux in compartment fire. The fire resistant board (fire-board) and steel plate compartments are constructed with a 0.3 m width, 0.5 m height and 3.0 m length. To obtain the mass loss rate considering the location of the fire origin in compartment, experiments of a heptane pool fire are performed with a combustion area of $0.01m^2$ and $0.0225m^2$. The results show that the initial mass flux of heptane, $0.0087kg/m^2{\cdot}s$, is increased to $0.166kg/m^2{\cdot}s$ for fire board and $0.019kg/m^2{\cdot}s$ for steel plate. It means that the fire-scenario should be considered with the thermal characteristics of the material properties and geometric shapes of the compartment to predict fire propagation accurately in a compartment space.

• Economic and Environmental Geology
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• v.52 no.1
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• pp.37-48
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• 2019

In geological $CO_2$ sequestration, the behavior of $CO_2$ within a reservoir can be characterized as two-phase flow in a porous media. For two phase flow, these processes include drainage, when a wetting fluid is displaced by a non-wetting fluid and imbibition, when a non-wetting fluid is displaced by a wetting fluid. In $CO_2$ sequestration, an understanding of drainage and imbibition processes and the resulting NW phase residual trapping are of critical importance to evaluate the impacts and efficiencies of these displacement process. This study aimed to observe migration and residual trapping of immiscible fluids in porous media via cyclic injection of drainage-imbibition. For this purpose, cyclic injection experiments by applying n-hexane and deionized water used as proxy fluid of $scCO_2$ and pore water were conducted in the two dimensional micromodel. The images from experiment were used to estimate the saturation and observed distribution of n-hexane and deionized water over the course drainage-imbibition cycles. Experimental results showed that n-hexane and deionized water are trapped by wettability, capillarity, dead end zone, entrapment and bypassing during $1^{st}$ drainage-imbibition cycle. Also, as cyclic injection proceeds, the flow path is simplified around the main flow path in the micromodel, and the saturation of injection fluid converges to remain constant. Experimental observation results can be used to predict the migration and distribution of $CO_2$ and pore water by reservoir environmental conditions and drainage-imbibition cycles.

• Journal of Internet Computing and Services
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• v.20 no.1
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• pp.17-24
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• 2019

Since the information of $4^{th}$ Industrial Revolution is introduced in WEF (World Economic Forum) in 2016, IoT, AI, Big Data, 5G, Cloud Computing, 3D/4DPrinting, Robotics, Nano Technology, and Bio Engineering have been rapidly developed as business applications as well as technologies themselves. Among the diverse business applications for IoT, wearable devices are recognized as the leading application devices for final customers. This longitudinal study is compared to the results of the 1st study conducted to identify customer needs of activity trackers, and links the identified users' needs with the well-known marketing frame of marketing mix. For this longitudinal study, a survey was applied to university students in June, 2018, and ANOVA were applied for major variables on usable features. Further, potential customer needs were identified and visualized by Word Cloud Technique. According to the analysis results, different from other high tech IT devices, activity trackers have diverse and unique potential needs. The results of this longitudinal study contribute primarily to understand usable features and their changes according to product maturity. It would provide some valuable implications in dynamic manner to activity tracker designers as well as researchers in this arena.

• Journal of Navigation and Port Research
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• v.43 no.1
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• pp.9-15
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• 2019

Mooring bollards are the mandatory facility in ports for they are the objects used to fasten the ship to its position at the berth. All the mooring bollards were installed following suggested sizes, numbers, materials and shape of installation according to Port and Fishing Design Standards. However, Korea has no management standard for use of mooring bollards to safety in ship berthing. In this research, the installation standard for mooring bollards including the holding power applied to mooring bollards in berthing was studied. Also, the performance of mooring bollards for minimum safety guarantee in berthing based on research of various specification by their sizes was analyzed. The analysis on mooring bollards was examined by each power on mooring bollards from the applied force in berthing divided into horizontal and vertical direction in order to examine the performance of domestic mooring bollards, the limit force is calculated based on detailed specification research result. As a result, the working stress according to the towing force was found to be at least 150Mpa and it was evaluated to be 60% of the limit strength. Also, by comparing each forces, the appropriateness was examined and the specification of maximum capability calculated. This performance evaluation method based on detail specification of mooring bollards will be expected to be useful to examine the appropriateness of mooring bollards for various types of vessel in berthing and to develop maintenance and management standard through the performance change evaluation referring to mooring bollard detailed specification changes.

• Korean Journal of Environment and Ecology
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• v.33 no.1
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• pp.107-115
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• 2019

The purpose of this study is to examine the effect of forest healing programs with walking, sightseeing, and forest scent among six healing forest treatments using forest environment on the cognitive function, depression, and quality of life of elderly living alone. The subjects of the study were 17 senior citizens living in Samcheok and complaining of severe depression and forgetfulness. They were divided into two groups, and each group participated in the six sessions of the weekly forest healing program. All of them were surveyed of a Korean version of the MMSE-K, BDI (Beck Depression Inventory Korean Version), and SF-36 (Short Form 36 health survey questionnaire) with the questionnaire designed for the one-group pre-post test to examine changes in cognitive function, depression, and quality of life. The results showed that the mental status, depression level, and quality of life of respondents were significantly higher after healing programs. These results suggest that participation in healing program activities using forest environment can improve cognitive function, relieve depression and improve quality of life for senior citizens living alone. Therefore, inducing older adults who live alone and avoid outside activities to participate in the regular forest healing program will contribute to the prevention of dementia due to age and environment.

• Journal of Life Science
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• v.29 no.1
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• pp.37-44
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• 2019

Leaves of Sasa quelpaertensis Nakai are used in folk medicine for their anti-inflammatory, antipyretic, and diuretic properties. To ensure efficient utilization of S. quelpaertensis leaf, we previously reported a preparation method for phytochemical-rich extract (PRE) using the leaf residue, which was produced after hot water extraction. This study was undertaken to evaluate the hypouricemic potential of S. quelpaertensis leaf PRE in potassium oxonate (PO)-induced hyperuricemic mice. The administration of PRE significantly reduced serum uric acid (UA), blood urea nitrogen (BUN), and serum creatinine levels and increased urine UA and creatinine levels in the PO-induced hyperuricemic mice. It also reduced liver UA levels and xanthine oxidase (XA) activity. A histological analysis revealed that PRE administration protected against PO-induced liver damage, pointing to anti-inflammatory and cytoprotective effects in PO-induced hyperuricemic mice. We analyzed the transcriptome response to PRE administration in PO-induced hyperuricemic mice using RNA sequencing (RNA-Seq) in kidney tissues. The administration of PRE mainly enriched genes involved in mediating immune and inflammatory responses and the metabolic pathway. A Kyoto Encyclopedia of Genes and Genomes (KEGG) analysis showed that the metabolic pathway, purine metabolism, and antibody biosynthesis were the major pathways altered in the PRE and PO groups. These results suggest a potential role for PRE in the prevention and treatment of hyperuricemia with inflammation.

• Journal of the Korean Institute of Landscape Architecture
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• v.47 no.1
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• pp.1-9
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• 2019

The objective of this study was to derive the served distance of the senior-friendly park considering physical changes, which were estimated through a comparison experiment at an actual target site. The time to walk 500m was examined because 500m is considered the served distance of a neighborhood park and as a standard set by the city. The mean walking time of the control group (younger than 65 years) was 536 seconds, while that of the treatment group (older than 65 years) was 889 seconds, which was approximately 1.7 times longer than the control group. The results of this study also showed that the walking time of females was longer than that of males when they were older than 65 years old. The walking velocities of the control group and the treatment groups were also calculated using the mean walking time. The weight estimated by a proportional formula was 0.6. When it was applied to 500m, which is the served distance of a neighborhood park, the served distance of the senior-friendly park was estimated as 300m. Lastly, the green service excluded area was quantified by applying the 300m, the served distance of a senior-friendly park, to the Jung-gu, Daegu, which had the highest elderly population in the Daegu Metropolitan City. The results of this calculation showed that the area served by a city park was $2,425,747m^2$ and the area excluded from the city park service was $4,627,700m^2$ for senior citizens. The results also showed that, in terms of the distributive equity, the administrative districts received unequal am ounts of urban green area services.

• Journal of Environmental Impact Assessment
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• v.28 no.1
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• pp.23-34
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• 2019

Global warming becomes a serious issue that poses subsidiary issues like a sea level rise or a capricious climate over the world. Because of severe heat-wave of the summer in Korea in 2016, a big attention has been focused on urban heat island since then. Not just about heat-wave itself, many researches have been concentrated on how to adapt in this trendy warming climate and weather in a small scope. A big part of existing studies is mitigating "Urban Heat Island effect" and that is because of huge impervious surface in urban area where highly populated areas do diverse activities. It is a serious problem that this thermal context has a high possibility causing mortality by heat vulnerability. However, there have been many articles of a green infrastructures' cooling impact in summer. This research pays attention to measure cooling effect of a street planting considering urban canyon and type of green infrastructures in neighborhood scale. This quantitative approach was proceeded by ENVI-met simulation with a spatial scope of a commercial block in Seoul, Korea. We found the dense double-row planting is more sensitive to change in temperature than that of the single-row. Among the double-row planting scenarios, shrubs which have narrow space between the plant and the land surface were found to store heat inside during the daytime and prevent emitting heat so as to have a higher temperature at night. The quantifying an amount of vegetated spaces' cooling effect research is expected to contribute to a study of the cost and benefit for the planting scenarios' assessment in the future.

• Journal of Industrial Convergence
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• v.16 no.1
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• pp.35-40
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• 2018

The procedural generation algorithm is an algorithm that automatically generates a content to be used in a game by repeatedly executing a series of rules. As the size of the game increases, the amount of content used in the game increases. Accordingly, artificial intelligence research is actively conducted to automatically generate game contents using game artificial intelligence such as procedural generation. In this paper, we propose an algorithm to create 3D game world using procedural generation. The proposed algorithm generates a two-dimensional contour in which the path is naturally connected using Perlin-Noise whose noise is gradually changed. A three-dimensional Height-Map is created based on the generated two-dimensional contour lines. The generated Height-Map show that the shape of the map is normal and that the player is able to move around all the sections as in the game world created by hand. In the future, we will improve the performance of algorithms and apply them to game.

• Korean Journal of Remote Sensing
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• v.35 no.3
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• pp.483-489
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• 2019

True color images display colors similar to natural colors. This has the advantage that it is possible to monitor rapidly the complex earth atmosphere phenomenon and the change of the surface type. Currently, various organizations are producing true color images. In Korea, it is necessary to produce true color images by replacing generations with next generation weather satellites. Therefore, in this study, visual enhancement for true color image production was performed using Top of Atmosphere (TOA) data of Advanced Himawari Imager (AHI) sensor mounted on Himawari-8 satellite. In order to improve the visualization, we performed two methods of Nonlinear enhancement and Histogram equalization. As a result, Histogram equalization showed a strong bluish image in the region over $70^{\circ}$ Solar Zenith Angle (SZA) compared to the Nonlinear enhancement and nonlinear enhancement technique showed a reddish vegetation area.