The design response spectrum presented in the seismic design standard reflects the characteristics of the tectonic environment at a site. However, since the design response spectrum does not represent the ground motion with a specific earthquake magnitude or distance, input ground motions for response history analysis need to be selected reasonably. It is appropriate to use observed ground motions recorded in Korea for the seismic design. However, recently recorded ground motions in the Gyeongju (2016) or Pohang (2017) earthquakes are not compatible with the design response spectrum. Therefore, it is necessary to convert the recorded ground motion in Korea to a model similar to the design response spectrum. In this study, several approaches to adjust the spectral acceleration level at each period range were tested. These are the intrinsic and scattering attenuation considering the earthquake environment, magnitude, distance change by the green function method, and a rupture propagation direction's directivity effect. Using these variables, the amplification ratio for the representative natural period was regressed. Finally, the optimum condition compatible with the design response spectrum was suggested, and the validation was performed by converting the recorded ground motion.

The brake system drives the vehicle by converting the kinetic energy into thermal energy. The heat energy generated during the braking process increases the temperature of the structure. It causes thermal deformation due to overheating and causes cracks, noise, and vibration that degrade performance. However, it is not possible to fundamentally prevent the temperature rise of the brakes. There is a need for research on improving the heat dissipation performance by improving the shape of the brake. Therefore, this study analyzed the concentrated stress caused by overheating of the brake disc. In order to improve the performance of the disk, shape optimization design was performed. For stress and thermal analysis, the analysis was conducted using the finite element program ANSYS Transient Thermal and Structural tools. PIAnO (Process Integration and Design Optimization) was used to perform optimal design. In the formulation of the optimum design, the stress was minimized by satisfying the constraints. This study intends to present a new brake disc model by performing perforated shape and arrangement.

High-pressure membrane system like nanofiltration(NF) and reverse osmosis(RO) was investigated as a part of water treatment processes to produce high quality potable water with low organic matter concentration through membrane module tests and design simulation. River water and sand filtration permeate in Busan D water treatment plant were selected as feed water, and NE4040-90 and RE4040-Fen(Toray Chemical Korea) were used as NF and RO membranes, respectively. Total organic carbon(TOC) concentrations of NF and RO permeates were mostly below 0.5 mg/l and the average TOC removal rates of NF and RO membranes were 93.99% and 94.28%, respectively, which means NF used in this study is competitive with RO in terms of organic matter removal ability. Different from ions rejection tendency, the TOC removal rate increases at higher recovery rates, which is because the portion of higher molecular weight materials in the concentrated raw water with increasing recovery rate increases. Discharge of NF/RO concentrates to rivers may not be acceptable because the increased TDS concentration of the concentrates can harm the river eco-system. Thus, the idea of using NF/RO concentrate as the raw water for industrial water production was introduced. The design simulation results with feed water and membranes used in this work reveal that the raw water guideline can be satisfied if the recovery rate of NF/RO system is designed below 80%.

본 연구에서는 철골편심가새골조 시스템을 대상으로 다목적최적화기법을 통해 설계를 수행하고 그 결과를 분석하였다. 최적화 설 계를 위해 유전 알고리즘의 일종인 NSGA-II를 활용하였다. 여기서, 목적함수는 이율배반적 관계를 갖는 구조물량과 층간변위로 하여 최소화되고, 제약조건에는 구조기준에서 요구하는 내력비, 링크의 회전각 등을 포함하였다. 제약조건은 최적화 알고리즘 내에서 각 항목을 위반할수록 목적함수 값을 크게 증가시키는 벌금함수의 형태를 가지고 있다. 설계기준에서 EBF 시스템의 설계규정은 링크 부재만 항복이 허용되며 나머지 부재는 링크 항복 시 발생되는 부재력을 탄성상태에서 견디도록 의도한 역량설계법에 기초한다. 그러나 최적화를 통해 도출된 결과 중 일부는 구조기준의 설계조항은 만족하지만 특정층 링크에 소성변형이 집중되어 연약층을 형성함 으로써 기준에서 의도하는 역량설계의 원칙을 위배하는 결과가 나타났다. 이를 해결하기 위해 모든 링크의 전단 초과강도계수 중 최 대값이 최소값의 1.25배를 넘지 않도록 하는 제약식을 추가하였다. 새로운 제약식을 추가한 경우 모든 최적해는 설계기준과 역량설계의 원칙을 준수하는 것으로 나타났다. 모든 설계안에서 보 경간에 대한 링크의 길이비는 전단링크의 범주에 해당하는 10% ~ 14%였다. 전체적으로 설계안들은 링크의 초과강도 계수비가 가장 지배적인 제약으로 작용하였으며, 구조기준의 요구사항 중 층간변위와 내력비 등의 항목에서 허용치에 비해 매우 보수적으로 설계되었다.

본 논문는 개폐식 대공간 구조물의 지진하중에 대한 동적응답을 줄이기 위한 목적으로 파라메트릭 설계 기법을 적용한 TMD에 관한 연구이다. 인공지능 알고리즘을 이용하여 감쇠장치의 설치 위치를 자동 탐색하는 컴포넌트를 개발하였다. 이는 구조물의 동적응답을 실시간으로 확인하고, 구조물의 감쇠장치 최적의 위치를 찾을 수 있을 있다. 또한, 여러 대안에 대한 감쇠장치 질량의 최적 값을 찾아주며, 지붕의 열린 상태와 닫힌 상태에 모두 효과적으로 적용될 수 있는 설계안을 찾을 수 있다.

The domestic of modern architectural remodeling method emphasizes simple aesthetic elements, and the correct design and construction methods are not established based on quantitative grounds, thus damaging the value of cultural properties. This study attempts to re-examine the value of modern buildings recognized as old buildings. It is a basic step to present the correct remodeling of the building. The design criteria for exterior wall remodeling of modern buildings were presented. These research results are suitable for energy conservation design standards and can prevent defects in buildings. In the future, more accurate analysis will be required by securing physical property values for various domestic materials through subsequent research.

In this study, we studied the method of using general architectural glass instead of using the existing acrylic material for high luminance flat lighting. The flat panel lighting used the side illumination method to increase the ease of installation and aesthetic satisfaction. In general, glass has an amorphous structure with a lower angle of refraction than acrylic, so it is not suitable for use in flat panel lighting as a light guide, but in this study, the role of light distribution characteristics and diffusion patterns in the case of using such a glass light guide. Quantitative simulations were conducted to confirm new possibilities. In the simulation, the backlight estimation method was used, and about 10,000,000 rays were placed within a unit area in order to obtain a result similar to the real thing. As a result of the simulation, the geometry of the diffusion pattern could be specified, and the value of the geometry could be quantified using the ratio of the diameter and height of the pattern. As a result of the calculation, it was found that the maximum amount of light was generated around 75 degrees by quantitatively calculating the ratio and the outgoing light angle at which the maximum value of the outgoing light occurred between 05 and 1.0. As a result of these studies, it was confirmed that it is possible to use ordinary glass at the same time as a transparent window and light-emitting lighting at night.

본 연구의 목적은 형광직물과 재귀반사 소재만으로 제작, 보급되고 있는 현 안전의복에, LED 부착으로 시인성을 높여 야간이나 기상악화 시 안전사고로부터 작업자나 보행자를 보호하고, 기울기 센서와 소리신호를 탑재하여 의식불명 자의 구명에 도움을 주는데 있다. 이를 위하여 공학적 하이테크를 적용하여 설계·제작한 산업용 서스펜더형 안전벨트 및 기울기 센서와 소리신호가 탑재된 안전조끼형 벨트를 개발하였다. 그 효과로 첫째, 서스펜더형 안전벨트는 필름에 접착된 자동 점멸 LED에 의해 빛을 방출하도록 설계하여 벨트 착용자의 신체는 LED와 재귀반사를 통해 멀리서 인식되 어 사고예방에 도움이 된다. 또한 야간에 실시하는 도로변이나 고지대에서의 작업, 구조대원 활동, 스포츠 활동 시 사고를 예방하거나, 비상상황이 발생할 경우 LED 발광을 변화시키는 신호로 사고 지점을 빨리 발견할 수 있어 인명구조 에 도움이 된다. 둘째, 착용자가 조난사고 등으로 인하여 의식불명으로 쓰러질 경우, 조난신호를 발생하는 첨단 디바이스를 개발하여 감지 및 신호 장치를 탑재한 결과 제어부의 기울기 센서가 인체의 각도를 자동 감지하였다. 동시에 조끼형의 벨트 형태로 제작함으로써 탈착이 용이하도록 하여 활용도를 높였다. 사고로 착용자가 쓰러지면 이 벨트의 기울기 센서가 각도를 감지하고 제어기가 고주파 음과 LED 점멸신호를 동시에 발생시킨다. 기존의 안전 조끼의 경우 주변 조명이 없을 때는 조끼를 착용한 사람을 감지하는 것이 거의 불가능 하였지만, 본 연구에서는 안전벨트의 음향과 빛 신호로 주변 조명이 없을 때에도 100 m 이내에서 착용자를 발견할 수 있었다. 그러므로 본 연구에서 LED 부착과 기울기 센서, 소리신호 소자를 부착한 스마트 안전의류의 개발은 사고발생 감소와 구명에 이바지할 수 있을 것이다.

목적 : 본 연구는 렌즈를 향해 입사하는 광선의 구면수차를 제거하기 위해 광선추적법과 스넬의 법칙을 사용하 여 계산과정을 유도하여 렌즈를 설계하였다. 방법 : 스넬의 법칙을 활용하여 렌즈의 초점이 한 점으로 진행하도록 역산하여 설계하는 과정을 거친 후 광학 시뮬레이션 소프트웨어인 SPEOS를 활용하여 수치를 측정하였다. 결과 : 렌즈의 입사각에 따라 렌즈의 후면 곡률반경이 변화하였고, 일정 입사고에 도달하였을 때 렌즈 후면의 곡률반경이 구면수차 보정함으로 인해 일정 입사고 이전의 값에서 변화하는 구간이 발생하였다. 결론 : 본 연구를 통해 구면수차를 제거하는 렌즈를 스넬의 법칙과 광선추적의 방식으로 설계하여 광학 시뮬레 이션 소프트웨어를 통하여 구현하였다. 이를 통하여 스넬의 법칙을 이용한 광선 추적방식의 설계가 구면수차를 제 거한 비구면렌즈의 제작에 있어서 도움이 될 것으로 기대한다.

Smart City operates with the purpose of solving urban problems. The important thing in smart city operation is that spatial information must be managed at a high level. In addition, it has the characteristics of being managed by one platform. This study presented the core value dimension of smart city based on analysis of various domestic and overseas smart city operation cases. Smart cities are basically operated based on spatial information, and the higher the level of spatial information, the more smart city services can be connected and managed in an integrated manner. The performance dimension of smart city core values presented in the study includes prosperity, personalization, convenience, accuracy, sustainability, safety, environment, integration, etc., and there is a connectivity dimension, a concept that can be managed in an integrated manner. This study will be useful for empirical research on smart city performance dimension design and surveys based on case studies. It will also help field managers who develop, operate, and manage smart cities when quantifying performance dimensions.

In recent years, importance of blockchain systems has been grown after success of bitcoin. Distributed consensus algorithm is used to achieve an agreement, which means the same information is recorded in all nodes participating in blockchain network. Various algorithms were suggested to resolve blockchain trilemma, which refers conflict between decentralization, scalability, security. An algorithm based on Byzantine Agreement among Decentralized Agents (BADA) were designed for the same manner, and it used limited committee that enables an efficient consensus among considerable number of nodes. In addition, election of committee based on Proof-of-Nonce guarantees decentralization and security. In spite of such prominence, application of BADA in actual blockchain system requires further researches about performance and essential features affecting on the performance. However, performance assessment committed in real systems takes a long time and costs a great deal of budget. Based on this motivation, we designed and implemented a simulator for measuring performance of BADA. Specifically, we defined a simulation framework including three components named simulator Command Line Interface, transaction generator, BADA nodes. Furthermore, we carried out response surface analysis for revealing latent relationship between performance measure and design parameters. By using obtained response surface models, we could find an optimal configuration of design parameters for achieving a given desirable performance level.

A manufacturing company should produce its products and make a profit to continue its management. With the adoption of a multi-category small-volume production system, manufacturers that produce concrete pump-cine products are carrying out improvement activities to increase their market share amid the business-to-customer business environment. However, the slump in the construction investment environment has led to a decline in sales of concrete pump trucks. The purpose of holding inventory is to prevent loss of sales opportunities with the rate of change in the sales plan, and reducing the rate of change in the product can reduce unnecessary inventory and, in order to realize this, the goal of reducing inventory can be achieved by reviewing the parts that can be designed for common use. Therefore, to reduce the inventory of concrete pump trucks, semi-finished publicization design is necessary. According to the analysis, the frame assembly process of the 32M model is common. Production capacity can be secured without loss of sales opportunity.

In this study, a tuned mass damper(TMD) was installed to control the displacement response to earthquakes by generalizing to six analysis models according to the shape of the upper structure based on the case of various large spatial structures around the world. The six analysis models are ribbed type, latticed type, elliptical type, gable type, barrel type, and stadium type composed of 3D arch trusses. In this paper, ribbed type, latticed type and elliptical type were analyzed. The mass of each TMD was set to 1% of the total structural mass. Result of analyzing the optimal number and position of the analysis model, the displacement response control was the most excellent in the model with 6 and 8 TMDs, and the displacement response decreased in most cases. The displacement response control was better with installing the TMD at the edge point than focusing the TMD at the center of the analysis model. However, when 10 or more TMDs are installed or concentrated in the center, large loads intensively act on the structure, resulting in increased displacement. Therefore, although it is slightly different depending on the shape, it is judged that the displacement response control is the best to install 6 and 8 TMDs at the close to the edge point.

In this study, a tuned mass damper(TMD) was installed to control the displacement response to earthquakes by generalizing to six analysis models according to the shape of the upper structure based on the case of various large spatial structures around the world. The six analysis models are ribbed type, latticed type, elliptical type, gable type, barrel type, and stadium type composed of 3D arch trusses. In this paper, ribbed type, latticed type and elliptical type were analyzed. The mass of each TMD was set to 1% of the total structural mass. Result of analyzing the optimal number and position of the analysis model, the displacement response control was the most excellent in the model with 6 and 8 TMDs, and the displacement response decreased in most cases. The displacement response control was better with installing the TMD at the edge point than focusing the TMD at the center of the analysis model. However, when 10 or more TMDs are installed or concentrated in the center, large loads intensively act on the structure, resulting in increased displacement. Therefore, although it is slightly different depending on the shape, it is judged that the displacement response control is the best to install 6 and 8 TMDs at the close to the edge point.

At ship design stage, the maneuverability is generally estimated based on the empirical formula or the computational fluid dynamic (CFD), which is one of the numerical simulation methods. Using the hydrodynamic derivatives derived through these methods can quantitatively estimate the maneuverability of target vessels and evaluate indirect maneuverability. Nevertheless, research on estimating maneuverability is insufficient for ships not subject to IMO maneuverability standard, especially fishing vessels, and even at the design stage, the empirical formula developed for merchant ships is applied without modification. An estimation error may occur due to the empirical formula derived from the regression analysis results of a model test if the empirical formula developed for merchant ships with different hull shapes is applied to fishing vessels without any modification. In this study, the modified empirical formula that can more accurately estimate the fishing vessel's maneuverability was derived by including the hull shape parameter of target fishing trawlers in the regression analysis process that derives Kijima et al. (1990) formula. As a result, the modified empirical formula showed an average estimation error of 6%, and the result improved the average error of 49% of Kijima et al. (1990) formula developed for merchant ships.

In the event of an earthquake, non-structural components require seismic performance to ensure evacuation routes and to protect lives from falling non-structural components. Accordingly, the seismic design code proposes horizontal force for the design and evaluation of non-structural components. Ground motion observed on each floor is affected by a building's eigen vibration mode. Therefore, the earthquake damage of non-structural components is determined by the characteristics of the non-structural component system and the vibration characteristics of the building. Floor response spectra in the seismic design code are estimated through time history analysis using seismic waves. However, it is difficult to use floor response spectra as a design criterion because of user-specific uncertainties of time history analysis. In addition, considering the response characteristics of high-rise buildings to long-period ground motions, the safety factor of the proposed horizontal force may be low. Therefore, this study carried out the horizontal force review proposed in the seismic design code through dynamic analysis and evaluated the floor response of seismic waves considering buildings and predominant periods of seismic waves.

In seismic design standards such as KDS 41 17 00 and ASCE 7, three procedures are provided to estimate seismic demands: equivalent lateral force (ELF), response spectrum analysis (RSA), and response history analysis (RHA). In this study, two steel special moment frames (SMFs) were designed with ELF and RSA, which have been commonly used in engineering practice. The collapse probabilities of the SMFs were evaluated according to FEMA P695 methodology. It was observed that collapse probabilities varied significantly in accordance with analysis procedures. SMFs designed with RSA (RSA-SMFs) had a higher probability of collapse than SMFs designed with ELF (ELFSMFs). Furthermore, RSA-SMFs did not satisfy the target collapse probability specified in ASCE 7-16 whereas ELF-SMFs met the target probability.

본 논문은 학부 외국인 유학생을 위한 한국 한자어 교육 방안을 원격 수업 설계 및 운영 사례를 중심으로 살펴보았다. 대학에서 원격 수업의 중요성과 비중이 갑작스레 커진 상황에서, 대면 수업에 준하는 수업 효율을 유지할 수 있는 방안을 찾는 일은 중요한 과제 가운데 하나라고 할 수 있다. 이 과정에서 ‘외국인 유학생 대상 한자(漢字) 수업’이라는 변수를 고려하여 실제 대학 강의 현장에서 수업 설계와 운영에 반영하고자 하였다. 원격 수업은 그 특성상 대면 수업이 가지는 현장성·동시성·양방향성·상호교감성을 완벽하게 재현해내기는 어렵다. 하지만 주어진 환경 속에서 대면 수업의 효율을 유지하고 원격 수업의 장점을 극대화하기 위한 노력이 필요하다는 점을 언급하였다. 코로나 19 이후 빠르게 변화하고 있는 강의 환경을 고려할 때, 본 연구를 하나의 사례로 삼아 후속 논의가 지속되기를 기대한다.