In order to obtain the goal of the weight reduction of automobile components, the researches about lighter and stronger wheel carriers have been studied without sacrificing the safety of them. In this study, the weight reduction design process of wheel carrier could be proposed based on the variation of von-Mises stress contour by substituting an AA6061 (aluminum 6061 alloy) having tensile strength of 310 MPa grade instead of FCD600 Irons. From the stress analysis results before and after design modification, the stress relaxation was done at every given loading conditions. Therefore, it could be reached that this approach method could be well established and be contributed for light-weight design guide and the optimum design conditions of the automotive wheel carrier development.

This study investigates on the tuning stainless steel(STS630) to understand for groove cutting characteristics. For this purpose, we observed the cutting force according to feed rate and cutting speed variation and performed the computational analysis due to groove cutting depth. In groove cutting of stainless steel, there were principal force, feed force and radial force by arranging the highest cutting force in order. In case of wall thicknesses of 0.3mm and 0.5mm at groove cutting, principal force increases according to the increase of feed rate but it is not related to cutting speed. We found the unstable region of cutting force that is caused to the friction resistance of cutting tool and elastic deformation of groove wall. In computational analysis, we confirmed that the more feed rate increases, the more strain increases around the tooth root.

항로표지란 해상교통의 안전을 도모하고 선박운항 능률을 향상시키기 위한 해양교통안전시설로 새로운 위험물(New Danger)은 측방표지, 방위표지, 고립장해표지 등을 이용하거나 비상침선표지(Emergency Wreck Marking Buoy)를 사용하여 적절하게 표시하여야 한다. 그러나, 침선표지의 경우 설치의 신속성, 정확성, 부표의 특성 등의 문제로 인해 실질적인 설치·운영상의 문제가 제기 되고 있으며, 선박침몰 사고의 경우 기상악화, 해역의 특성, 사고 위치의 확인이 어려워 신속한 신위험물표지(New Danger Mark) 설치가 어려운 실정이다. 이 연구는 항상 선박 상갑판에 부착된 해양안전설비 중 하나로 Maritime Buoyage System(MBS)에 근거한 자동이탈식 비상침선표지를 개발하였다. 자동이탈식 비상침선표지Auto Releasing Emergency Wreck Marking Buoy)는 총 3개의 세부기술(자동이탈, 자동릴체인, 자동구동등명기)로 구성되며, 선박 상갑판에 부착된 자동이탈식 비상침선표지가 선박의 좌초 전복 침몰 등 해양사고 발생 시 일정수압에 의해 자동으로 이탈(Auto Release) 후 자기 부상(Auto Buoyance)하여 사고 발생 지점에 신속하고 정확하게 설치된다. 이러한 자동이탈식 비상침선표지는 선박의 항해안전을 위협하는 장해물로부터 해당 해역에서의 2차 사고를 방지하고, 신속한 수색 및 구조가 이루어질 수 있도록 한다.

본 논문은 확장된 프로젝션 기법을 사용한 위상 최적설계 방법을 다루고 있다. 다양한 형상과 길이 스케일을 가지는 프로젝션 함수를 개발해 위상 최적설계 기법에 적용시킴으로써, 복합재료의 설계에서 형상 및 크기가 미리 주어진 보강재의 최적 배치를 위상 최적설계를 통해 결정할 수 있음을 확인하였다. 또한 이와 같은 프로젝션 기법이 균질화법과 결합되어 체적탄성률 또는 전단탄성률 등의 유효 재료특성을 최대화시키는 단위 구조를 설계함으로써, 주기 구조를 가지는 복합재료에서 보강재의 최적 배치를 결정하고 그 유효 재료특성값을 수치적으로 계산할 수 있음을 여러 수치 예제들을 통해서 검증하였다.

본 논문은 확장된 프로젝션 기법을 사용한 위상 최적설계 방법을 다루고 있다. 다양한 형상과 길이 스케일을 가지는 프로 젝션 함수를 개발해 위상 최적설계 기법에 적용시킴으로써, 복합재료의 설계에서 형상 및 크기가 미리 주어진 보강재의 최 적 배치를 위상 최적설계를 통해 결정할 수 있음을 확인하였다. 또한 이와 같은 프로젝션 기법이 균질화법과 결합되어 체적 탄성률 또는 전단탄성률 등의 유효 재료특성을 최대화시키는 단위 구조를 설계함으로써, 주기 구조를 가지는 복합재료에서 보강재의 최적 배치를 결정하고 그 유효 재료특성값을 수치적으로 계산할 수 있음을 여러 수치 예제들을 통해서 검증하였다.

In military, empty cartridge recovery case of personal small arms is a device used to collect the empty cartridge after consumption of bullets. It has different shapes depending on the shape of small arms. However, It should be designed in a shape that wraps around the outlet for empty cartridge and it should be no restrictions to the movement of small arms. It has been used to spread military. but military is demanding design improvement due to frequent damage of empty cartridge recovery case. In this report, We improved the shape of the product in order to prevent damage to the product and verified through the FEM analysis and prototype test. According to the result of simulation, best modified modelling of this study has been reduced about 19% of the stress compared to initial modelling. In addition, modified products were confirmed durability, wearability and fixability through fire test.

A new design concept for integrated thermal energy storage system is suggested to increase energy saving rate for heating and cooling system of the closed glass greenhouse. Heat pump of air source is installed in the mechanical room and air flows then controlled by damper system located between the greenhouse and outdoor environments. A damper control algorithm is designed to enhance the usage of excessive energy in the glass greenhouse. Since the proposed system is installed at the actual glass greenhouse site for experimental verification of energy savings, the proposed system with damper control is compared with conventional greenhouse heating and cooling system. From results, it is found that more than 10% increase of energy saving rate is achieved.

In the companion papers (I, II), site-specific response analyses were performed at more than 300 domestic sites and a new site classification system and design response spectra (DRS) were proposed using the results of the site-specific response analyses. In this paper, the proposed site classification system and the design response spectra are compared with those in other seismic codes and verified by different methods. Firstly, the design response spectra are compared with the design response spectra in Eurocode 8, KBC 2016 and MOCT 1997 to estimate quantitative differences and general trends. Secondly, site-specific response analyses are carried out using VS-profiles obtained using field seismic tests and the results are compared with the proposed DRS in order to reduce the uncertainty in using the SPT-N value in site-specific response analyses in the companion paper (I). In addition, site coefficients from real earthquake records measured in Korean peninsula are used to compare with the proposed site coefficients. Finally, dynamic centrifuge tests are also performed to simulate the representative Korean site conditions, such as shallow depth to bedrock and short-period amplification characteristics. The overall results showed that the proposed site classification system and design response spectra reasonably represented the site amplification characteristic of shallow bedrock condition in Korea.

본 연구에서는 철골모멘트골조의 보-힌지 붕괴모드를 유도하는 최적 내진설계기법을 제안한다. 이는 유전자알고리즘을 사용하며, 기둥의 소성힌지 발생을 억제하는 제약조건을 설정하여 보-힌지 붕괴모드를 유도한다. 제안하는 기법은 구조물량를 최소화하고 에너지소산능력을 최대화하는 목적함수를 사용한다. 제안하는 기법은 9층 철골모멘트골조 예제 적용을 통해 검증한다. 예제 적용을 통해 철골모멘트골조의 보-힌지 붕괴모드를 유도하기 위해 요구되는 기둥-보 강도비를 평가한다. 패널존에 대한 3가지 모델링 기법을 각각 적용하여 모델링 조건에 따른 휨강도비 영향이 추가적으로 검토된다.

In the companion paper (I – Database and Site Response Analyses), site-specific response analyses were performed at more than 300 domestic sites. In this study, a new site classification system and design response spectra are proposed using results of the site-specific response analyses. Depth to bedrock (H) and average shear wave velocity of soil above the bedrock (VS,Soil) were adopted as parameters to classify the sites into sub-categories because these two factors mostly affect site amplification, especially for shallow bedrock region. The 20 m of depth to bedrock was selected as the initial parameter for site classification based on the trend of site coefficients obtained from the site-specific response analyses. The sites having less than 20 m of depth to bedrock (H1 sites) are sub-divided into two site classes using 260 m/s of VS,Soil while the sites having greater than 20 m of depth to bedrock (H2 sites) are sub-divided into two site classes at VS,Soil equal to 180 m/s. The integration interval of 0.4 ~ 1.5 sec period range was adopted to calculate the long-period site coefficients (Fv) for reflecting the amplification characteristics of Korean geological condition. In addition, the frequency distribution of depth to bedrock reported for Korean sites was also considered in calculating the site coefficients for H2 sites to incorporate sites having greater than 30 m of depth to bedrock. The relationships between the site coefficients and rock shaking intensity were proposed and then subsequently compared with the site coefficients of similar site classes suggested in other codes.

Korea is part of a region of low to moderate seismicity located inside the Eurasian plate with bedrock located at depths less than 30 m. However, the spectral acceleration obtained from site response analyses based on the geologic conditions of inland areas of the Korean peninsula are significantly different from the current Korean seismic code. Therefore, suitable site classification scheme and design response spectra based on local site conditions in the Korean peninsula are required to produce reliable estimates of earthquake ground motion. In this study, site-specific response analyses were performed at more than 300 sites with at least 100 sites at each site categories of SC, SD, and SE as defined in the current seismic code in Korea. The process of creating a huge database of input parameters - such as shear wave velocity profiles, normalized shear modulus reduction curves, damping curves, and input earthquake motions - for site response analyses were described. The response spectra and site coefficients obtained from site response analyses were compared with those proposed for the site categories in the current code. Problems with the current seismic design code were subsequently discussed, and the development and verifications of new site classification system and corresponding design response spectra are detailed in companion papers (II-development of new site categories and design response spectra and III-Verifications)

Peak load rate(i.e., maximum daily flow/average daily flow) has not been considered for industrial water demand planning in Korea to date, while area unit method based on average daily flow has been applied to decide capacity of industrial water treatment plants(WTPs). Designers of industrial WTPs has assumed that peak load would not exist if operation rate of factories in industrial sites were close to 100%. However, peak load rates were calculated as 1.10~2.53 based on daily water flow from 2009 to 2014 for 9 industrial WTPs which have been operated more than 9 years(9-38 years). Furthermore, average operation rates of 9 industrial WTPs was less than 70% which means current area unit method has tendency to overestimate water demand. Therefore, it is not reasonable to consider peak load for the calculation of water demand under current area unit method application to prevent overestimation. However, for the precise future industrial water demand calculation more precise data gathering for average daily flow and consideration of peak load rate are recommended.

타지키스탄공화국에는 10군데의 우라늄광산 부지에 55백만톤의 우라늄광산 폐기물이 적치 되어 있는데 부지 면적이 200 핵 타아르에 달한다. 이에 따라 우라늄 폐광과 폐기물의 안전한 관리가 주요 이슈로 부각되고 있다. 부지 복원을 위한 천연방벽 과 인공방벽으로 구성된 다중 복토층은 성능 목표와 부지 조건을 고려하여 설치되어야 한다. 본 논문의 목적은 Degmay 부 지에 장기간 (100년 이상)의 환경보호를 제공할 수 있는 경제적인 다중 복토층 개념을 제시 하는 것이다. HELP 코드를 사용 하여 Degmay 부지의 복토층 설계 개념의 평가를 수행하였다. 그 결과 70 cm의 덮개층, 30 cm의 배수층, 지오멤브레인 라 이너 그리고 60 cm의 토양 방벽층으로 구성된 복토층 개념이 두께를 최소화 할 수 있고 비교된 여러 설계개념 중 가장 경제 적인 설계 안으로 제시되었다.

본 연구에서는 BES 기법을 활용하여 온실을 대상으로 실시간 에너지교환 시뮬레이션 모델 개발 및 검증을 수행하고 냉·난방부하 산정 및 경향성을 분석하였다. 우선 BES 기법과 현장실험을 기반으로 온실의 실시간 에너지 교환 모델을 개발하였다. 광흡수율, 엽면적지수, 잎 특성 길이 등 대상작물인 애플망고의 특성 값들과 온실 내부 이산화탄소 농도, 광량, 온도 등 실시간 입력 자료를 고려하여 작물 및 토양의 에너지교환을 구현하였다. 모델의 검증은 온실 내부 기온으로 수행하였으며 실측 내부 기온과 연산된 내부 기온 간의 결정계수, 일치도로 평가 하였다. 내부 기온 비교는 결정계수 0.89, 일치도 0.93으로 높은 유사성을 확인하였으며 모델의 유의성을 판단하였다. 개발한 모델과 2005년부터 2014년까지의 기상자료, 대상작물의 생육단계별 적정생육온도를 이용하여 대상온실의 냉·난방부하 산정하였다. 연도별 냉·난방부하산정 및 경향성을 파악하였으며 최대 냉·난방부하 산정을 통하여 대상온실의 냉·난방장치 용량설계의 기초자료를 확보하였다. 최근 10년 치 기상자료를 통하여 평균 최대 난방부하 525,473 kJ·hr-1, 평균 최대냉방부하 630,870 kJ·hr-1가 산정되었으며 대상 온실에 지열, 온배수, 태양열 등 신재생에너지를 활용할 경우 유용하게 활용될 것으로 판단된다. 본 연구를 통하여 온실 내 각 구성요소 간의 실시간 에너지교환을 모의할 수 있었으며 추후 온배수 활용을 위한 저류조, 히트펌프, 축열조 등의 설비를 구현함에 따라 전반적인 냉·난방 시스템의 구현 가능성을 확인하였다. 또한 동적 해석방법을 통하여 재배작물, 생육단계 및 토양을 고려하였으며 온실 에너지교환 모델에 다양한 형태로 적용 가능할 것으로 판단된다.

The purpose of this study is to present a method that can estimate the height of reaction facilities for large structural experiment through load flow as primary design procedure. The characteristic of the load transmission according to the type of experiment was analyzed to obtain tensile and compressive forces occurring on the reaction facilities. Strong walls that are affected by the bending moment is applied the post-tensioning method, and the strong floor under the control of the tension and compression is designed in accordance with the load flow. And the optimum cross-section of the reaction facilities was obtained by comparing the stresses of the tensile stress and crack the concrete. Through validating elastic analysis, the design results were satisfied a given design conditions.

In mobile communication systems, location management deals with the location determination of users in a network. One of the strategies used in location management is to partition the network into location areas. Each location area consists of a group of cells. The goal of location management is to partition the network into a number of location areas such that the total paging cost and handoff (or update) cost is a minimum. Finding the optimal number of location areas and the corresponding configuration of the partitioned network is a difficult combinatorial optimization problem. This cell grouping problem is to find a compromise between the location update and paging operations such that the cost of mobile terminal location tracking is a minimum in location area wireless network. In fact, this is shown to be an NP-complete problem in an earlier study. In this paper, artificial bee colony (ABC) is developed and proposed to obtain the best/optimal group of cells for location area planning for location management system. The performance of the artificial bee colony (ABC) is better than or similar to those of other population-based algorithms with the advantage of employing fewer control parameters. The important control parameter of ABC is only ‘Limit’ which is the number of trials after which a food source is assumed to be abandoned. Simulation results for 16, 36, and 64 cell grouping problems in wireless network show that the performance of our ABC is better than those alternatives such as ant colony optimization (ACO) and particle swarm optimization (PSO).

This paper analyzes the simulation operation flow of Bullet physics engine. Based on this analysis, four kinds of multi-rigid-body game characters are designed. This paper also profiles the performance metrics such as the CPU utilization, the memory usage, and the computation time by multi-rigid-body character simulations. For the CPU utilization, the Tongs Vehicle is the best and provides 45.1% less than the other character simulations. The computation times of the Four-leg robot and the Dragon are longer than those of the others. The memory usage of the Dragon simulation is the largest, which is average 1.32 times more than the others. Because all parts of Dragon are composed of triangular mesh models in 3DMax. The performance profiling with the criteria such as reducing the computation time and the computing resources, the complexities of the collision shapes, and the number of rigid bodies takes an important role in the design of the multi-rigid-body game characters.

The objective of this study is to propose methods to design and analyze a catenary shell using a computer program without experiments and measurements. The intial idea stems from Pendergrast’s study, but his method should be improved. In this study, the process of making catenary shell using computer was reproduced by Grasshopper script. In order to enhance credibility, two models from Grasshopper script were analyzed by SAP2000; one was just a square-based catenary shell, while the other was the re-created shell originated from the Naturtheater Grötzingen. The outcome of analysis was reasonable.