• Atmosphere
• /
• v.31 no.4
• /
• pp.421-431
• /
• 2021

The Yeongdong region is frequently vulnerable to heavy snowfall in winter in terms of societal and economical damages. By virtue of a lot of previous efforts, snowfall forecast has been significantly improved, but the performance of light snowfall forecast is still poor since it is very conducive to synoptic and mesoscale interactions, largely attributable to Taeback mountains and East Sea effects. An intensive observation has been made in cooperation with Gangwon Regional Meteorological Office and National Institute of Meteorological Studies in winter seasons since 2019. Two distinctive Cold Air Damming (CAD) events (14 February 2019 and 6 February 2020) were observed for two years when the snowfall forecast was wrong specifically in its location and timing. For two CAD events, lower-level temperature below 2 km ranged to lowest limit in comparisons to those of the previous 6-years (2014~2019) rawinsonde soundings, along with the stronger inversion strength (> 2.0℃) and thicker inversion depth (> 700 m). Further, the northwesterly was predominant within the CAD layer, whereas the weak easterly wind was exhibited above the CAD layer. For the CAD events, strong cold air accumulation along the east side of Taeback Mountains appeared to prevent snow cloud and convergence zone from penetrating into the Yeongdong region. We need to investigate the influence of CAD on snowfall in the Yeongdong region using continuous intensive observation and modeling studies altogether. In addition, the effect of synoptic and mesoscale interactions on snowfall, such as nighttime drainage wind and land breeze, should be also examined.

• Journal of Ocean Engineering and Technology
• /
• v.35 no.5
• /
• pp.382-392
• /
• 2021

In recent years, floating offshore wind turbines have attracted more attention as a new renewable energy resource while bottom-fixed offshore wind turbines reach their limit of water depth. Various projects have been proposed with the rapid increase in installed floating wind power capacity, but the economic aspect remains as a biggest issue. To figure out sensible approaches for saving costs, a comparison analysis of the levelized cost of electricity (LCOE) between floating and bottom-fixed offshore wind turbines was carried out. The LCOE was reviewed from a social perspective and a cost breakdown and a literature review analysis were used to itemize the costs into its various components in each level of power plant and system integration. The results show that the highest proportion in capital expenditure of a floating offshore wind turbine results in the substructure part, which is the main difference from a bottom-fixed wind turbine. A floating offshore wind turbine was found to have several advantages over a bottom-fixed wind turbine. Although a similarity in operation and maintenance cost structure is revealed, a floating wind turbine still has the benefit of being able to be maintained at a seaport. After emphasizing the cost-reduction advantages of a floating wind turbine, its LCOE outlook is provided to give a brief overview in the following years. Finally, some estimated cost drivers, such as economics of scale, wind turbine rating, a floater with mooring system, and grid connection cost, are outlined as proposals for floating wind LCOE reduction.

• The Journal of the Korea Contents Association
• /
• v.19 no.8
• /
• pp.35-43
• /
• 2019

There has been not the research on the reason of success based on the characteristic of narrative and characters of , I defined the major characteristic of this genre as family animation, and aimed at researching strategic character and narrative. The characteristics of each characters are identified, and compared with other animation, soap opera, and sitcom. The portion that characters participated in the narrative was analyzed, and the relationship between the point and viewers was also researched in the specific episodes. 1) The characters against the ideal ones function to satirize the fixed idea pursued by the mass, and stimulate the viewers' desire. 2) All the characters are protagonist and sometimes antagonist, or advisor. The circulating position expands the target of viewers, and decreases the cultural discount. 3) It produces a couple of layered narrative, then children, teenagers, and adults enjoy the each different depth of the narrative, resulted in the target expansion. Considering on the limit of theme and target in Korean animation, I expect the findings above will enable to produce more valuable and consistent contents. Later, characters in the Korean family animation is to be researched and the expandability and sustainability would be ensured.

• Earthquakes and Structures
• /
• v.21 no.5
• /
• pp.515-530
• /
• 2021

In a tall reinforced concrete (RC) core wall system subjected to strong ground motions, inelastic behavior near the base as well as mid-height of the wall is possible. Generally, the formation of plastic hinge in a core wall system may lead to extensive damage and significant repairing cost. A new configuration of core structures consisting of buckling restrained braced frames (BRBFs) and RC walls is an interesting idea in tall building seismic design. This concept can be used in the plan configuration of tall core wall systems. In this study, tall buildings with different configurations of combined core systems were designed and analyzed. Nonlinear time history analysis at severe earthquake level was performed and the results were compared for different configurations. The results demonstrate that using enough BRBFs can reduce the large curvature ductility demand at the base and mid-height of RC core wall systems and also can reduce the maximum inter-story drift ratio. For a better investigation of the structural behavior, the probabilistic approach can lead to in-depth insight. Therefore, incremental dynamic analysis (IDA) curves were calculated to assess the performance. Fragility curves at different limit states were then extracted and compared. Mean IDA curves demonstrate better behavior for a combined system, compared with conventional RC core wall systems. Collapse margin ratio for a RC core wall only system and RC core with enough BRBFs were almost 1.05 and 1.92 respectively. Therefore, it appears that using one RC core wall combined with enough BRBF core is an effective idea to achieve more confidence against tall building collapse and the results demonstrated the potential of the proposed system.

• Journal of the Korean Geotechnical Society
• /
• v.38 no.8
• /
• pp.53-66
• /
• 2022

The national ground survey database (GeoInfo) distributes numerous ground survey data nationwide. Many standard penetration test results exist in this database; however, the number of shear wave velocity (V_S) data is small. Hence, to use abundant standard penetration test-N values to predict V_S, this study proposed a new empirical N-V_S relationship model using GeoInfo data. The proposed N-V_S model is a single equation regardless of geological layer types; the layer type only specifies the upper limit of V_S. To validate the proposed model, residual analysis was performed using a test dataset that was not used for the model development. Therefore, this study's proposed model performed better than N-V_S models from previous studies. Since the N-V_S model in this study was developed using sufficient data from GeoInfo, we expect that it is the most applicable to GeoInfo dataset for V_S prediction.

• Journal of Practical Agriculture & Fisheries Research
• /
• v.10 no.1
• /
• pp.29-41
• /
• 2008

This research was conducted to develop a technology transfer and farmer's extension of newly released technology of Bokto seeding method for crop and vegetable production based on the theory of Asian and Pacific Center for Transfer of Technology(APCTT). This technology has recently transferred to not only Korea but also other countries like North Korea, China, Japan, Taiwan, Russia and Africa(Cameroon, Sudan and South Africa) since 2005. It has known as a highly reduction of production cost in terms of labors, chemical fertilizer and pesticides as well as environmental friendly due to a deep and side banded placement of chemical fertilizer at basal application. In addition this technology was proven to a precision farming on sowing depth and mechanism of chemical application method and also highly resistant against disasters like typhoon, flooding, low temperature, drought and lodging due to silicate application. It has improved a constraints such as a poor seedling establishment, weed occurrence, lodging, low yield and poor grain and eating quality in the previous direct seeding methods but still have a problem in occurrence of weedy rice and ununiformed operation of wet or flooded soil condition. Also this technology has a limit in marketing and A/S system. Based on a theory of APCTT evaluation and analysis this technology may be more concentrated on establishment of a special cooperation team among researcher and scientists, extension workers, industry sections and governmental sectors in order to rapidly transfer this technology to farmer's field. Also there will be needed to operate a web site for this newly released technology to inform and exchange an idea, experiences and newly improved information. A feed back system might be operated in this technology as well to improve a technology under way on users' operation. Also user's manual will be internationally released and provided for farmer's instruction and training at field site.

• Journal of The Korea Institute of Healthcare Architecture
• /
• v.29 no.2
• /
• pp.7-16
• /
• 2023

Purpose: Seclusion room in a psychiatric facility limit the body and space for treatment or protection, so controversy over human rights violations arises despite their necessity. The seclusion room should be created as an environment that can promote the recovery and healing of patients, not the purpose of managing patients. while ensuring the safety of medical staff. Therefore, the purpose of this study is to compare and analyze the standards of overseas guidelines for the seclusion room in psychiatric facility, and through this, it is intended to contribute to the improvement of facility standards for seclusion rooms in Korea, which are at a very insufficient level. Method: This study takes the method of comparative analysis through literature review. We analyze the facility standards of seclusion room in Korea, and compare and analyze guidelines for seclusion rooms in Australia, US, UK, and Canada. Result: As a result, the elements of the guideline for seclusion room were classified into size, space, opening, furniture and equipment, and etc. The results of comparative analysis of details are presented. Implications: Korea should also prepare guidelines for psychiatric institutions, and among them, the standards for seclusion room, which are at the center of controversy over human rights violations, should be reviewed in depth.

• Steel and Composite Structures
• /
• v.44 no.4
• /
• pp.503-517
• /
• 2022

This paper presents the mechanical buckling of bi-directional functionally graded sandwich beams (BFGSW) with various boundary conditions employing a quasi-3D beam theory, including an integral term in the displacement field, which reduces the number of unknowns and governing equations. The beams are composed of three layers. The core is made from two constituents and varies across the thickness; however, the covering layers of the beams are made of bidirectional functionally graded material (BFGSW) and vary smoothly along the beam length and thickness directions. The power gradation model is considered to estimate the variation of material properties. The used formulation reflects the transverse shear effect and uses only three variables without including the correction factor used in the first shear deformation theory (FSDT) proposed by Timoshenko. The principle of virtual forces is used to obtain stability equations. Moreover, the impacts of the control of the power-law index, layer thickness ratio, length-to-depth ratio, and boundary conditions on buckling response are demonstrated. Our contribution in the present work is applying an analytical solution to investigate the stability behavior of bidirectional FG sandwich beams under various boundary conditions.

• Geomechanics and Engineering
• /
• v.35 no.5
• /
• pp.525-538
• /
• 2023

The development of a city is closely linked to the construction and operation of its subway system. However, constructing a new subway tunnel under an existing station is an extremely complex task, and the deformation characteristics and mechanical behavior of the new subway tunnel during the excavation process can greatly impact the normal operation of the existing station. Although the previous studies about the case of underpass engineering have been carried out, there is limited research on the condition of a newly-built subway tunnel that closely undercrossing an existing station with zero distance between them. Therefore, this study analyzes the deformation law and mechanical behavior characteristics of the preliminary lining of the underpass tunnel during the excavation process based on the real engineering case of Chengdu Metro Line 8. This study also makes an in-depth comparison of the influence of different excavation methods on this issue. Finally, the accuracy of numerical simulation is verified by comparing it with on-site result. The results indicate that the maximum bending moment mainly occurs at the floor slab of the preliminary lining, while that of the ceiling is small. The stress state at the ceiling position is less affected by the construction process of the pilot tunnel. Compared to the all-in-one excavation method, although the process of partial excavation method is more complicated, the deformation of preliminary lining caused by it is basically less than the upper limit value of the standard, while that of the all-in-one excavation method is beyond standard requirements.

• Korean Journal of Ichthyology
• /
• v.35 no.4
• /
• pp.366-371
• /
• 2023

A shrimp goby, Amblyeleotris japonica is reported firstly from Korea, based on a single specimen (70.3 mm in SL) collected at a depth of 14 m in the southern Jejudo Island. The species is characterized by having a lower number of scales in longitudinal series, a rather compressed body, anterior limit of opercular opening located below between posterior margin of eye and preopercle, second dorsal fin with a single spine and 13 soft rays, anal fin with a single spine and 14 soft rays, and five brownish vertical bands on lateral body between head and caudal peduncle when fresh. New Korean names, "Se-u-but-i-mang-dug-sog" and "Bulg-eun-dong-gal-se-u-but-i-mang-dug", are proposed for the genus and the species, respectively.