• Journal of the Korean housing association
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• v.24 no.1
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• pp.21-31
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• 2013

This study focuses on the regional characteristics observed in the composition and floor plan of folk houses in the Young-cheon region situated in the Southern East inland of Gyungsangbukdo. According to the typical characteristics of the Korean folk house, Young-cheon region is supposed to be classified as the Young-Nam region. Our study shows that the open inverse 'ㄱ' type composition is the most common among others, which consists the living room, UtChae and one BoosokChae that serves as a living room and a farm shop. The typical floor plan is called 'Young Nam type' 'H$\hat{o}$tjib' composed of four rooms. Young Nam type of house has a wall in front of the room floor with a door to make the space with the room floor as the internal space. This can be explained by the climatic conditions in the Southern region of Gyungsangbukdo, which has a very cold winter and has a harsh spring wind in Young-cheon. The structural feature to which we should pay attention is the Young Nam type house has a gambrel roof. The evolutions of the house in the 70s are observed in the roof during the Saemaeul Movement from a hut to a modernized roof. In the 80s, the replacement of the heating system, expansion of rooms, modernization of kitchen, replacement of paper windows, modernization of roof, and construction of amenities had taken place to change the space, construction and structure following the modern house features.

• Korean Institute of Interior Design Journal
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• v.20 no.5
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• pp.135-142
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• 2011

This study applies the 'interface' as the concept to interpret the facade design of parking garages. This study investigates the characteristics of interface design in the parking garages to improve design qualities of parking garages as a daily living space as well as a public space in today's city. The facade of parking garage is an interface between the urban streets and the parking space. Three concepts of interface and design in parking garage are defined. The concept of interface is explained as a boundary surface which activates communication and interaction. In facade design of parking garage, three main concepts of interface design are screen, communication and mobility. Through the investigation of the examples, this study summarizes the characteristics of the facade design of parking garage as follow; first, the facade of parking garage is designed as a screen which represents immateriality by specially selected and arranged surface materials. The screen facade is designed as one homogeneous surface as well as an irregular pattern with operable louvers. Second, the facade of parking garage is designed as a communication media to deliver direct information. The representation of natural or artificial characteristics at the local areas is to communicate with the people in the community. Third, the facade of parking garage is represented mobility which a car symbolizes. It emphasizes various movements and visual changes by movements. People can experience the visual changes of the building facade as they walk or drive. The visual changes of the facade are caused by natural elements such as wind and light as well as an optical illusion.

• Atmosphere
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• v.18 no.4
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• pp.317-338
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• 2008

Analyses of observational data and numerical simulations were performed to understand the mechanism of MCSs (Mesoscale Convective Systems) occurred on 13-14 July 2004 over Jindo area of the Korean Peninsula. Observations indicated that synoptic environment was favorable for the occurrence of heavy rainfall. This heavy rainfall appeared to have been enhanced by convergence around the Changma front and synoptic scale lifting. From the analyses of storm environment using Haenam upper-air observation data, it was confirmed that strong convective instability was present around the Jindo area. Instability indices such as K-index, SSI-index showed favorable condition for strong convection. In addition, warm advection in the lower troposphere and cold advection in the middle troposphere were detected from wind profiler data. The size of storm, that produced heavy rainfall over Jindo area, was smaller than $50{\times}50km^2$ according to radar observation. The storm developed more than 10 km in height, but high reflectivity (rain rate 30 mm/hr) was limited under 6 km. It can be judged that convection cells, which form cloud clusters, occurred on the inflow area of the Changma front. In numerical simulation, high CAPE (Convective Available Potential Energy) was found in the southwest of the Korean Peninsula. However, heavy rainfall was restricted to the Jindo area with high CIN (Convective INhibition) and high CAPE. From the observations of vertical drop size distribution from MRR (Micro Rain Radar) and the analyses of numerically simulated hydrometeors such as graupel etc., it can be inferred that melted graupels enhanced collision and coalescence process of heavy precipitation systems.

• Ocean and Polar Research
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• v.28 no.3
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• pp.245-258
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• 2006

We investigated seasonal variations of the upper ocean temperature and the mixed layer depth (MLD) in an eddy-permitting global ocean general circulation model (OGCM) to assess the OGCM perfermance. The OGCM is based on the GFDL MOM3 which has a horizontal resolution of 0.5 degree and 30 vertical levels. The OGCM was integrated for 68 years using a monthly-mean climatological wind stress forcing. The model sea surface temperature (SST) and sea surface salinity were restored to the Levitus climatology with a time scale of 30 days. Annual-mean model SST shows a cold bias $(<\;-2^{\circ}C)$ in the summer hemisphere and a warm bias $(>\;1^{\circ}C)$ in the winter hemisphere mainly due to the restoring boundary condition of temperature. The model MLD captures well the observed features in most areas, with a slightly deep bias. However, in the Ross Sea and Weddell Sea, the model shows significantly deeper MLD than the climatology-mainly due to weak salinity stratifications in the model. For amplitude of seasonal variation, the model SST is smaller $(1{\sim}3^{\circ}C)$ than the observation largely due to the restoring surface boundary condition while the model MLD has larger seasonal variation $({\sim}50m)$. It is suggested that for more realistic simulation of the upper ocean structure in the present eddy-permitting ocean model, more refinements in the surface boundary condition for the thermohaline forcing and parameterization for vertical mixing are required, together with the incorporation of a sea-ice model.

• Journal of the Korean Society of Environmental Restoration Technology
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• v.16 no.3
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• pp.107-117
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• 2013

Problems in regard of ecological stability of urban ecosystem ensue from climate change and urbanization. Particularly, urban ecological conditions are deteriorating both quantitatively and qualitatively to a great extent. The present study aims to assess the current condition of selected sites (i. e. urban green zones and parks) in terms of preset assessment components; to find out problems and relevant solutions to improve the quality and quantity of parks and green zones; and ultimately to suggest some measures applicable to coping with climate change as well as to securing the ecological attributes of urban green zones and parks. According to the findings of this study, from quantitative perspectives, ecological attributes and responsiveness to climate change are high on account of the large natural-soil area(80%). By contrast, from qualitative perspectives including the planting structure (1 layer: 47%), the percentage of bush area(17%), the connectivity with surrounding green zones (independent types: 44%), the wind paths considered (5.6%), the tree species with high carbon absorption rates (20%), water cycles (17%), energy (8%) and carbon storage capacities(61%), ecological attributes and responsiveness to climate change were found very low. These findings suggest that the ecological values of urban parks and green zones should be improved in the future by conserving their original forms, securing natural-soil grounds and employing multi-layered planting structures and water bodies, and that responsiveness to climate change should be enhanced by planting tree species with high carbon storage capacities and obtaining detention ponds. In sum, robust efforts should be exerted in the initial planning stages, and sustained, to apply the methodology of green-zone development along with securing ecological attributes and responsiveness to climate change.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.25 no.5
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• pp.713-721
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• 2001

Characteristics of the conical vortices on the roof corner of a rectangular prism have been investigated by using a PIV(Particle Image Velocimetry) technique. The Reynolds number based on the free stream velocity and the height of the model was 5.3$\times$10$^3$. The mean, instantaneous velocity vector fields, vorticity fields, and turbulent kinetic energy distribution were measured for two different angles of attack, 30$^{\circ}$and 45$^{\circ}$. The PIV measurements clearly observed not only the conical main vortex and the secondary vortex but also the tertiary vortex which is firstly reported in this paper. Asymmetric formation of the corner vortex for the case of 30$^{\circ}$angle of attack produces relatively the high magnitude of vorticity and turbulent kinetic energy around the bigger vortex which generates the peak suction pressure on the roof. Fairly symmetric features of the roof vortex are observed in the case of 45$^{\circ}$angle of attack, however, the dynamic characteristics are proved to be asymmetric due to the rectangular shape of the roof.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2014.10a
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• pp.557-561
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• 2014

In this work, Altair Engineering's vibroacoustic modeling approach is used to simulate the acoustic signature of a simplified automobile in a wind tunnel. The modeling approach relies on a two step procedure involving simulation and extraction of acoustic sources using a high fidelity Computational Fluid Dynamics (CFD) simulation followed by propagation of the acoustic energy within the structure and passenger compartment using a structural dynamics solver. The tools necessary to complete this process are contained within Altair's HyperWorks CAE software suite. The CFD simulations are performed using AcuSolve and the structural simulations are performed using OptiStruct. This vibroacoustics simulation methodology relies on calculation of the acoustic sources from the flow solution computed by AcuSolve. The sources are based on Lighthill's analogy and are sampled directly on the acoustic mesh. Once the acoustic sources have been computed, they are transformed into the frequency domain using a Fast Fourier Transform (FFT) with advanced sampling and are subsequently used in the structural acoustics model. Although this approach does require the CFD solver to have knowledge of the acoustic simulation domain a priori, it avoids modeling errors introduced by evaluation of the acoustic source terms using dissimilar meshes and numerical methods. The aforementioned modeling approach is demonstrated on the Hyundai Simplified Model (HSM) geometry in this work. This geometry contains flow features that are representative of the dominant noise sources in a typical automobile design; namely vortex shedding from the passenger compartment A-pillar and bluff body shedding from the side view mirrors. The geometry also contains a thick poroelastic material on the interior that acts to reduce the acoustic noise. This material is modeled using a Biot material formulation during the structural acoustic simulation. Successful prediction of the acoustic noise within the HSM geometry serves to validate the vibroacoustic modeling approach for automotive applications.

• Journal of Korean Society on Water Environment
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• v.36 no.1
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• pp.14-28
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• 2020

Future climate change may affect the hydro-thermal and biogeochemical characteristics of dam reservoirs, the most important water resources in Korea. Thus, scientific projection of the impact of climate change on the reservoir environment, factoring uncertainties, is crucial for sustainable water use. The purpose of this study was to predict the future water temperature and stratification structure of the Soyanggang Reservoir in response to a total of 42 scenarios, combining two climate scenarios, seven GCM models, one surface runoff model, and three wind scenarios of hydrodynamic model, and to quantify the uncertainty of each modeling step and scenario. Although there are differences depending on the scenarios, the annual reservoir water temperature tended to rise steadily. In the RCP 4.5 and 8.5 scenarios, the upper water temperature is expected to rise by 0.029 ℃ (±0.012)/year and 0.048 ℃ (±0.014)/year, respectively. These rise rates are correspond to 88.1 % and 85.7 % of the air temperature rise rate. Meanwhile, the lower water temperature is expected to rise by 0.016 ℃ (±0.009)/year and 0.027 ℃ (±0.010)/year, respectively, which is approximately 48.6 % and 46.3 % of the air temperature rise rate. Additionally, as the water temperatures rises, the stratification strength of the reservoir is expected to be stronger, and the number of days when the temperature difference between the upper and lower layers exceeds 5 ℃ increases in the future. As a result of uncertainty quantification, the uncertainty of the GCM models showed the highest contribution with 55.8 %, followed by 30.8 % RCP scenario, and 12.8 % W2 model.

• Proceedings of the Korea Water Resources Association Conference
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• 2004.05b
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• pp.1445-1449
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• 2004

Even though there can be a relative long-term or short-term change of their size in natural beaches due to various changes of sea condition such as the location, weather condition (wind and rain) and sea water flow, the budget of deposits in a specific area is generally regarded to be in a condition of equilibrium in terms of technology. However, as coasts are developed by many different kinds of ways (such as construction of sea walls and estuarine, dredging for gathering the aggregate and shore protection construction for establishing a structure) and sources of silt and gravel from rivers are decreased in balanced beaches, the beaches are in a serious danger of lack of sand and sand sources which are one of the maul elements to consist of them. Many swimming beaches in East Sea are directly exposed by waves generated and transmitted from outer seas. On the other hand, the Song-Do sandy beach which is this study's target area has a great condition for beach development because it locates the deepest place that is relatively shallow in Young-Il Man and there is big energy decrease given to waves from outer seas while the waves are reaching the Song-Do beach. Nevertheless, it is considered that artificial condition changes such as dredging for site extension by POSCO, getting straight of Hyoung-San Gang river flow and extension of Po-Hang harbor caused the sand loss of the beach. Therefore, some recovery plans of Song-Do sandy beach will be presented in this study and they will be compared and examined each other by numerical modeling experiment. After that, the best plan will be recommended.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.17 no.4
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• pp.13-18
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• 2016

Humidifiers are used to control indoor humidity. Element-type humidifiers have the advantages of simple structure and low energy consumption, and Japanese products have been widely used for the humidifying elements. In this study, a new humidifying element made of cellulose and PET was developed, and the performance was compared with that of a Japanese element. The mass transfer rates and pressure drops were measured for an element installed at the entrance of a suction-type wind tunnel. The humidification efficiency of the new element was 2 to 4% greater and the pressure drop was 23 to 32% smaller compared to the Japanese element. The mass transfer effectiveness ($j_m/f$) of the new element is also 5 to 28% higher. However, the water absorption capacity was smaller than that of the Japanese element, meaning further development is needed.