• The Journal of the Convergence on Culture Technology
• /
• v.9 no.1
• /
• pp.525-530
• /
• 2023

Although double-stage hanger is used in many homes for its space utilization and ease of installation, it is inconvenient for users to take off clothes hung on the upper bar due to its high height. Therefore, this paper proposes a new type of double-stage hanger that allows users to easily hang or take out clothes hung on the upper bar while maintaining the function of the existing double-stage hanger. 4-bar link mechanism is applied so that the upper bar can come down to a convenient height with one operation. In addition, an appropriate link shape, length, and joint type are selected so that the height is adjusted three-dimensionally to prevent overlapping of clothes hanging on upper/lower bars. FEA analysis is performed to ensure that the presented hanger shape can support the load of clothes during height adjustment and the feasibility of the three-dimensional height adjustment hanger is verified through fabrication.

• KSCE Journal of Civil and Environmental Engineering Research
• /
• v.28 no.3D
• /
• pp.431-436
• /
• 2008

Recently, the rapid development of GIS technology has made it possible to handle a various data associated with spatially hydrological parameters with their attribute information. Therefore, there has been a shift in focus from lumped runoff models to distributed runoff models, as the latter can consider temporal and spatial variations of discharge. In this research, a distributed rainfall-runoff model based on physical kinematic wave for analysis of surface and river flow was used to simulate temporal and spatial distribution of long-term discharge. The snowfall and melting process model based on Hydro-BEAM was developed, and various hydrological parameters for input data of the model was extracted from basic GIS data such as DEM, land cover and soil map. The developed model was applied for the Shonai River basin(532) in Japan, which has sufficient meteorological and hydrological data, and displayed precise runoff results to be compared to the hydrograph.

• Proceedings of the Korea Water Resources Association Conference
• /
• 2022.05a
• /
• pp.372-372
• /
• 2022

스마트시티 하천관리를 위해 선행된 연구에서는 도시하천관련 데이터를 수집-정제-제공하는 도시하천 통합데이터 플랫폼을 개발하였다. 이에 하천 분석을 위한 유역 유출, 하천 흐름 그리고 도시유출 등의 모듈과 하천 환경, 친수, 종합 평가 모델을 연계하여 도시하천관리 연계플랫폼으로 연구개발을 진행하였다. 본 연구에서는 스마트시티 하천관리를 위한 시나리오 기반 제방 파제 시뮬레이션 분석 결과 가시화 모듈에 관한 연구를 진행한다. 부산 EDC 지역을 대상으로 DEM, 항공영상, 위성영상, 하천 지리 정보, 하천 단면도 등의 데이터를 결합하여 하천 및 유역 전산 3D 형상 모델링을 진행한다. 또한 하천 내부 유량 및 파제 제체 모델링, 유동장 격자 모델링을 통해 제방 붕괴 범람 시뮬레이션 대상 지역을 구현한다. 해당 EDC 지역 구현 모델에 연속방정식, 운동량방정식, 수송방정식 등 지배방정식과 삼상 유동 기법 등 수치 해석 기법을 활용하여 제방 파제 시뮬레이션을 수행한다. 시뮬레이션의 침수범위 및 침수심 분포 결과는 위경도를 포함한 ASCII Grid로 반환되며 GeoServer를 통한 좌표계 설정 및 도시하천 연계플랫폼에서 가시화하는 연구를 진행하였다. 제방 파제 시나리오는 제방 높이 2m, 제방 폭 7.5m, 파제 길이 20m로 설정하여 4개의 붕괴 위치를 지정하였고, 지정된 위치에 대한 제방 파제 3D 시뮬레이션을 통해 도출된 Case 별 2D/3D 영상과 침수심 공간 분포에 대한 Raster Graphics를 전처리하여 시나리오별 침수범위-침수심을 도시하천 연계플랫폼 상에서 가시화하는 연구를 진행하였다. 도시하천 연계플랫폼의 시나리오 기반 제방 파제 시뮬레이션 모듈을 통하여 스마트시티의 제방 파제 피해 양상 및 대책 마련 의사결정 보조로 활용할 수 있을 것으로 기대된다.

• Journal of Korean Society of Disaster and Security
• /
• v.16 no.2
• /
• pp.65-73
• /
• 2023

Fishways are essential structures that must be installed in rivers to facilitate the movement of fish between upstream and downstream areas. However, the efficiency of fish passage varies depending on the flow conditions within the fishway. Therefore, this study examined the fish-friendly flow characteristics within a stepped fishway at different overflow depths using FLOW-3D, and conducted experiments for model validation. The key parameters affecting fish swimming ability include velocity, turbulent kinetic energy, and energy dissipation rate. These factors were assessed using a simulated fish species, the zacco platypus, to evaluate the suitability of fish-friendly flow condition. It was confirmed that overflow depth significantly influences fish behavior, and an appropriate overflow depth is required for stepped fishway design. The results of this study are expected to serve as fundamental data for the design of stepped fishways in the future.

• The Journal of the Convergence on Culture Technology
• /
• v.9 no.6
• /
• pp.429-434
• /
• 2023

Kitchen cabinets are essential furniture for storing the kitchen tools, but their high installed location makes it difficult for users to access the upper of the cabinets. Therefore, in this paper, we propose a new type of kitchen cabinet that allows users to easily take out or store items by adding new height adjustment features while maintaining the function of the existing cabinet. For convenience and safety, an appropriate complex link mechanism is designed so that the selected floor, not the entire cabinet, can come down to a desired height with one operation. Moreover, the optimal descent path is set to prevent the floor tilting or interfloor interference during descent, and appropriate link shapes, lengths, and joint types are selected to implement it. FEA analysis is performed to ensure that the stretched complex linkage can support the load of the stored items and the feasibility of the height adjustable kitchen cabinet is verified through fabrication.

• The Journal of the Acoustical Society of Korea
• /
• v.43 no.4
• /
• pp.455-465
• /
• 2024

In shallow water, the array invariant, known as the effective range estimation method, is developed based on the broadband dispersion characteristics in an ideal waveguide, which can be summarized by the waveguide invariant. It is robust enough to estimate both the array tilt and range simultaneously, even in situations where array tilt exists. Recently, it has been extended to fully consider the angle dependence of the waveguide invariant. However, applying the array invariant in range-dependent environments instead of range-independent environments can lead to range estimation errors due to bathymetry mismatch. In this paper, we interpret such range estimation errors by introducing the concept of effective range. Through numerical simulations and experimental data in a weakly range-dependent environment, we demonstrate the relationship between range estimation errors and effective range.

• Journal of the Earthquake Engineering Society of Korea
• /
• v.28 no.5
• /
• pp.233-247
• /
• 2024

The damage to structures during an earthquake can be varied depending on the frequency characteristics of seismic waves and the geological properties of the ground. Therefore, considering such attributes in the design ground motions is crucial. The Korean seismic design standard (KDS 17 10 00) provides design response spectra for various ground classifications. If required for time-domain analysis, ground motion time series can be either selected and adjusted from motions recorded at rock sites in intraplate regions or artificially synthesized. Ground motion time series at soil sites should be obtained from site response analysis. However, in practice, selecting suitable ground motion records is challenging due to the overall lack of large earthquakes in intraplate regions, and artificially synthesized time series often leads to unrealistic responses of structures. As an alternative approach, this study provides a case study of generating ground motion time series based on the hybrid broadband ground motion simulation of selected scenario earthquakes at sites in the Nakdonggang delta region. This research is significant as it provides a novel method for generating ground motion time series that can be used in seismic design and response analysis. For large-magnitude earthquake scenarios close to the epicenter, the simulated response spectra surpassed the 1000-year design response spectra in some specific frequency ranges. Subsequently, the acceleration time series at each location were used as input motions to perform nonlinear 1D site response analysis through the PySeismoSoil Package to account for the site response characteristics at each location. The results of the study revealed a tendency to amplify ground motion in the mid to long-period range in most places within the study area. Additionally, significant amplification in the short-period range was observed in some locations characterized by a thin soil layer and relatively high shear wave velocity soil near the upper bedrock.

• Journal of the Earthquake Engineering Society of Korea
• /
• v.1 no.2
• /
• pp.1-15
• /
• 1997

This paper presents substructural identification methods for the assessment of local damages in complex and large structural systems. For this purpose, an auto-regressive and moving average with stochastic input (ARMAX) model is derived for a substructure to process the measurement data impaired by noises. Using the substructural methods, the number of unknown parameters for each identification can be significantly reduced, hence the convergence and accuracy of estimation can be improved. Secondly, the damage index is defined as the ratio of the current stiffness to the baseline value at each element for the damage assessment. The indirect estimation method was performed using the estimated results from the identification of the system matrices from the substructural identification. To demonstrate the proposed techniques, several simulation and experimental example analyses are carried out for structural models of a 2-span truss structure, a 3-span continuous beam model and 3-story building model. The results indicate that the present substructural identification method and damage estimation methods are effective and efficient for local damage estimation of complex structures.

• Journal of the Korean Chemical Society
• /
• v.60 no.6
• /
• pp.436-451
• /
• 2016

This study analyzed activities in chemistry chapters of middle school science textbooks for the 2009 revised curriculum using 8 science practices. All the activities that students could experience inquiry were analyzed in this study. There were the most activities in 'Molecular motion and change of state' and the least activities in 'Heat and our life' of three textbooks. There were the most science practices in 'Features of substance' in two textbooks, but there were the least science practice in 'Heat and our life' of three textbooks. 'Investigation planning and performing', 'data analyzing and interpreting', and 'explanation composition and problem solution designing' were frequently included, but 'asking questions and defining issues' was not included at all. For 'Investigation planning and performing', 'data analyzing and interpreting', and 'explanation composition and problem solution designing', a variety of achievement goals were targeted while a few goals were frequently targeted. Two to four kinds of science practices were frequently included in an inquiry activity. There were few activity that includes over 5 different kinds of science practice.

• Journal of Christian Education in Korea
• /
• v.63
• /
• pp.317-345
• /
• 2020

The dissolution and reconstruction of the male-centered social structure is being requested, but the Korean church still call on women and understand women's roles by limiting them based on traditional 'normal family ideology' and matherhood discourse. However, considering women's various aspects of life, life cycle, and individuality, confining women to existing biological maternal discourse is not suitable to help women grow as subjective leaders and contribute to society. The Korean church needs to find a new curriculum that encourages women to form subjective beliefs. In the life of Christian women of the period of port-opening, we can examine the process of the Korean Christian women establishing the subjectivity of the challenges of Protestant theology, which included stereotypes, gender division of labor, and matherhood discourse. Korean Christian women shared the oppressive experiences of traditional patriarchy after passing silent and receptive perceptions, forming a subjective perception of their injustice and seeking liberation. And it was able to act as a subject of faith by forming a procedural and constructive awareness within a sympathetic and relational community. The Korean church should reconstruct the Christian women's curriculum by reflecting on the curriculum that women formed themselves over 100 years ago.