본 연구는 VR을 활용한 중국문화수업을 국내 중국어 혹은 중국문화교육에서 학습 자에게 IT 기술을 활용한 새로운 학습방법을 제시하고 학습효과를 높이는 것에 그 목적이 있다. 본 연구에서는 중국문화수업의 설계 방법을 도출하고 몰입 방법에 따라 ‘완전몰입형’, ‘부분몰입형’, ‘비몰입형’의 세 가지 방법으로 VR 중국문화수업 설계 방안을 제안하였으며 각 방식에 따라 장·단점과 학습효과 등을 분석하였다. 또한 설계방안을 바탕으로 실제 수업 사례를 들어 살펴보았다. 끝으로 VR을 활용한 중국문 화수업 설계를 위한 VR 콘텐츠 사용 빈도와 비중 조절, 적절한 환경구축을 위한 지원과 기술적인 지원을 제안하였다.

캐주얼게임은 게임의 난이도나 규칙이 어려운 하드코어 게임에 비해 상대적으로 규칙이 쉽고 간단한 게임을 말한다. 캐주얼 게임은 게임의 특성상 짧은 여유시간에 즐기는 킬링 타임용 플레이에 더 적합하며, 단순한 규칙을 바탕으로 다양한 사용자층이 쉽게 즐길 수 있는 장점을 가진 콘텐츠이다. 2016년 이후글로벌 게임 산업의 비중에 있어서도 모바일 게임 시장 규모가 다른 플랫폼을 넘어섰으며, 캐주얼 게임의 장점과 특징이 모바일 게임 시장의 성장과 확대에 큰 영향을 미쳤다. 캐주얼 게임은 간단하고 사용자가 게임을 이해하기 쉬운 구성을 가지고 있으며, 순차적인 난이도 구성을 통해 사용자에게 지속적인 도전의식을 부여하여 안정적인 과금 설계 및 수익 모델 구축이 가능하다. 최근 중ž소 개발사들의 신규 게임 서비스 이후 생존이 점차 어려워지고 있으며, 이는 게임의 서비스 이후 체계적이고 효율적인 운영 솔루션 구축의 부재로 인한 결과로 유추가 가능하다. 본 연구에서는 모바일 게임의 글로벌 서비스를 위해 게임 사용자의 요구사항에 빠르게 대처하며, 개발 비용을 절감하고 업무의 효율성을 증가시킬 수 있도록 운영 툴을 설계하고 구현한다.

Seismic designs for Korean nuclear power plants (NPPs) under earthquakes’ design basis are noticed due to the recent earthquake events in Korea and Japan. Japan has developed the technologies and experiences of the NPPs through theoretical research and experimental verification with extensively accumulated measurement data. This paper describes the main features of the design-time history complying with the Japanese seismic design standard. Proper seed motions in the earthquake catalog are used to generate one set of design time histories. A magnitude and epicentral distance specify the amplitude envelope function configuring the shape of the earthquake. Cumulative velocity response spectral values of the design time histories are compared and checked to the target response spectra. Spectral accelerations of the time histories and the multiple-damping target response spectra are also checked to exceed. The generated design time histories are input to the reactor building seismic analyses with fixed-base boundary conditions to calculate the seismic responses. Another set of design time histories is generated to comply with Korean seismic design procedures for NPPs and used for seismic input motions to the same reactor containment building seismic analyses. The responses at the dome apex of the building are compared and analyzed. The generated design time histories will be also applied to subsequent seismic analyses of other Korean standard NPP structures.

본 연구에서는 20,000 톤급 해양플랜트 상부구조물(Topside)의 플로트오버 설치작업을 위해 개발된 수동형 갑판 지지 프레임 (Deck support frame)의 구조설계에 대해 다양한 실험계획법을 이용한 최소중량설계와 민감도 평가의 비교연구를 수행하였다. 수동형 갑판 지지 프레임의 주요 구조부재의 두께 치수 변수는 설계인자로 고려하였고, 응답치는 중량과 강도성능으로 선정하였다. 최소중량설계와 민감도 평가의 비교연구에 사용한 실험계획법은 직교배열설계법, Box-Behnken 설계법, 그리고 Latin hypercube 설계법이다. 실험계획법의 설계공간 탐색의 근사화 성능을 평가하기 위해 반응표면법을 각 실험계획법 별로 생성하여 근사화 정확도 특성을 검토하였다. 또한 최소 중량설계를 위해 최상 설계안의 결과로 부터 실험계획법의 특성에 따른 수치계산 비용, 중량감소 효과 등을 평가하였다. 수동형 갑판 지지 프레임의 구조설계에 대해 Box-Behnken 설계법이 가장 적합한 설계 결과를 나타내었다.

In this study, the cooling performance of the motor was analyzed according to the number and the length of the fins of the heat sink, and at the same time, the effect of forced convection on the cooling performance improvement by changing the air flow speed of the cooling fan was conducted. In order to find out the cooling performance in terms of turbulent kinetic energy, pressure, and temperature according to the number of heat sink fins, length of fins, and wind speed of the cooling fan, an aluminum heat sink was modeled according to the size of the motor. The heating value of the motor was calculated, and it was set to be the same under all analysis conditions. The turbulence model applied for numerical analysis in this study used the standard k-ε model. As a result, it was confirmed that the cooling effect of the heat sink increases as the air flow speed of the cooling fan, the number of fins, and the length of fins increase.

LMU(Leg Mating Unit)는 해양구조물의 플로트오버 실치에서 활용되는 장비 중 하나로 충격을 흡수하는 부분과 결합부로 구성된다. 본 연구에서는 최적설계를 통해 부유식 해양구조물의 플로트오버 설치용 LMU의 성능을 개선하여 설계 요구 조건을 만족하는 설계를 개발하였다. 초기설계는 고정식 해양구조물의 플로트오버 설치용으로 개발된 것의 제원을 참조하였으며, 초탄성재료의 거동을 표현하기 위해 Mooney-Rivlin 모델을 활용하였다. 설계민감도해석 결과를 바탕으로 중요도에 따라 설계 변수들을 선별하였고, 진화 알고리듬 기반 최적설계를 수행하였다. 최적설계 문제에서 목적함수는 LMU의 중량이며, 제약 조건은 LMU에 작용하는 최대 폰-미세스 응력과 LMU의 성능을 평가할 수 있는 반발력이다.

The purpose of this study was to develop an optimized hull-form of a coastal fishing vessel operating at high speed. In order to achieve the purpose of the study, HOTBOAT, that can perform an automatic hull-form optimal design of a coastal fishing vessel, was developed. HOTBOAT was composed of an objective function estimation algorithm and an optimization algorithm and a hull-form modification algorithm. In this study, the wave-making resistance was selected as an objective function and the potential-based panel method was applied to predict the objective function. SQP(sequential quadratic programming) method were adopted to predict the optimal direction and answer. Bell-shaped hull-form modification function method and NURBS(non-uniform rational B-spline) geometry modeling method were applied to modify the hull-form during the whole optimization process. HOTBOAT was applied to develop the optimal hull-form of a coastal fishing vessel with minimum wave resistance. The initial hull-form of the coastal fishing vessel was compared with the optimal hull-form. As a result of hull-form optimization, a coastal fishing vessel with a reduction of about 30% was developed compared with the initial hull-form and the displacement and the wetted surface area of the optimal hull-form was decreased to less than about 1% in comparison with the initial hull-form.

PURPOSES : The purpose of this study is to contribute to the utilization of standards while considering the possible upgrade of a local system as a subject of the application. Therefore, this study aims to explore the possible application of LandInfra for a local road management (maintenance) system in the context of enabling the basis of 3D geospatial road information management in Korea. METHODS : Based on a review of related literature and international standards, an analysis of the current system is performed. After reviewing the LandInfra standard, an examination of corresponding classes between each data model (HMS and LandInfra) is performed for the mapping process. After the mapping process, a data model of the LandInfra-based HMS pavement data model is proposed. RESULTS : To apply the LandInfa to the HMS pavement part, an examination of each data model is performed. After this procedure, a LandInfra-based HMS pavement database schema is proposed in the context of enabling 3D geospatial road information management and maintenance, particularly for pavement management information. CONCLUSIONS : This paper presents how the LandInfra international open geospatial standard can be applied to the local road management system (HMS pavement part). As a result of this study, the LandInfra standard could be applied to the HMS; however, an encoding of the standard is required for conformance. Thus, further studies would be the encoding of the proposed data model for conformance with InfaGML encoding standards. In addition, a system prototype may be needed for complete application.

Eutrophication and algal blooms can lead to increase of taste and odor compounds and health problems by cyanobacterial toxins. To cope with these eco-social issues, Ministry of Environment in Korea has been reinforcing the effluent standards of wastewater treatment facilities. As a result, various advanced phosphorus removal processes have been adopted in each wastewater treatment plant nation-widely. However, a lot of existing advanced wastewater treatment processes have been facing the problems of expensive cost in operation and excessive sludge production caused by high dosage of coagulant. In this study, the sedimentation and dissolved air flotation (SeDAF) process integrated with sedimentation and flotation has been developed for enhanced phosphorus removal in wastewater treatment facilities. Design and operating parameters of the SeDAF process with the capacity of 100 m3/d were determined, and a demonstration plant has been installed and operated at I wastewater treatment facility (located in Gyeonggi-do) for the verification of field applicability. Several empirical evaluations for the SeDAF process were performed at demonstration-plant scale, and the results showed clearly that T-P and turbidity values of treated water were to satisfy the highest effluent standards below 0.2 mg/L and 2.0 NTU stably for all of operation cases.

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.