• Computers and Concrete
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• 제13권1호
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• pp.71-82
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• 2014

Chloride ion ingress is one of the major problems that affect the durability of concrete structures such as bridge decks, concrete pavements, and other structures exposed to harsh saline environments. Therefore, durability based design of concrete structures in severe condition has gained great significance in recent decades and various mathematical models for estimating the service life of rein-forced concrete have been proposed. In spite of comprehensive researches on the corrosion of rein-forced concrete, there are still various controversial concepts in quantitation of durability parameters such as chloride diffusion coefficient and surface chloride content. Effect of environment conditions on the durability of concrete structures is one of the most important issues. Hence, regional investigations are necessary for durability based design and evaluation of the models. Persian Gulf is one of the most aggressive regions of the world because of elevated temperature and humidity as well as high content of chloride ions in seawater. The aim of this study is evaluation of some parameters of durability of RC structures in marine environment from viewpoint of corrosion initiation. For this purpose, some experiments were carried out on the real RC structures and in laboratory. The result showed that various uncertainties in parameters of durability were existed.

• 한국음향학회지
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• 제9권4호
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• pp.33-44
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• 1990

본 연구는 공동주택의 자기세대에서 가족간의 프라이버시를 확보하고 쾌적한 환경을 유지하기 위해 필요한 차음성능 설계목표치를 설정한 후 기존 공동주택의 소음환경 실태를 파악, 설계목표치와 비교하였다. 또한 현행 공법을 다양하게 변화하여 설계목표치를 만족하는 조건을 찾고자 하였다. 이를 위해 세대내에서의 주침실, 자녀실 및 거실의 실간 차음성능을 파악하였으며, 실배치유형에 따른 차음성능 변화, 구성 재료 변화에 따른 플러쉬도아의 차음성능, 경량벽체의 구성재료 변화에 따른 차음성능 변화를 검토하여 소음환경 개선방안을 제시하였다.

• Journal of Astronomy and Space Sciences
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• 제27권4호
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• pp.377-382
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• 2010

In lunar explorer development program, computer simulator is necessary to provide virtual environments that vehicle confronts in lunar transfer, orbit, and landing missions, and to analyze dynamic behavior of the spacecraft under these environments. Objective of simulation differs depending on its application in spacecraft development cycle. Scope of use cases considered in this paper includes simulation of software based, processor and/or hardware in the loop, and support of ground-based flight test of developed vehicle. These use cases represent early phase in development cycle but reusability of modeling results in the next design phase is considered in defining requirements. A simulator architecture in which simulator platform is located in the middle and modules for modeling, analyzing, and three dimensional visualizing are connected to that platform is suggested. Baseline concepts and requirements for simulator development are described. Result of trade study for selecting simulation platform and approaches of defining other simulator components are summarized. Finally, characters of lunar elevation map data which is necessary for lunar terrain generation is described.

• 항공우주시스템공학회지
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• 제10권3호
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• pp.63-69
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• 2016

The properties of composite materials, when compared to those of metallic materials, are highly variable due to many factors including the batch-to-batch variability of raw materials, the prepreg manufacturing process, material handling, part-fabrication techniques, ply-stacking sequences, environmental conditions, and test procedures. It is therefore necessary to apply reliable statistical-analysis techniques to obtain the design allowables of composite materials. A new composite-material qualification process has been developed by the Advanced General Aviation Transport Experiments (AGATE) consortium to yield the lamina-design allowables of composite materials according to standardized coupon-level tests and statistical techniques; moreover, the generated allowables database can be shared among multiple users without a repeating of the full qualification procedure by each user. In 2005, NASA established the National Center for Advanced Materials Performance (NCAMP) with the purpose of refining and enhancing the AGATE process to a self-sustaining level to serve the entire aerospace industry. In this paper, the statistical techniques and procedures for the generation of the allowables of aerospace composite materials will be discussed with a focus on the pooling-across-environments method.

• 제어로봇시스템학회논문지
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• 제12권2호
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• pp.154-160
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• 2006

Instantaneous reaction and intelligence are required for autonomous mobile robots to achieve multiple goals in the unpredictable and dynamic environments. Design of the appropriate control architecture and clear definitions of systems are needed to construct and control these robots. This research proposes the hybrid deliberative/reactive control architecture which consists of three layers and uses the method of software structure design. The highest layer, Deliberative Layer makes the overall run-time schedule for navigation and/or manipulation, and the middle layer, Task Execution Layer carries out various missions. The lowest layer, Reactive Layer enables a robot to react rapidly in the dynamic environment and controls the mechanical devices concurrently. This paper proposes independent system supervisors called Manager to reuse the modules so that the Manager supports common use of the system and multi-processing tasks. It is shown that the mobile robot based on the proposed control scheme can perform the basic navigation and cope with the dynamic obstacles reasonably well.

• 한국CDE학회논문집
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• 제19권2호
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• pp.157-168
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• 2014

In this paper, HSE (Health and Safety Environments) research with smart device and biometrics is conducted for the worker's HSE enhancement in the manufacturing shop floor. Today, various kinds of smart devices are popularized extensively. In addition, the wearable type devices are being introduced such as google glass very recently. Smart device of werable type is exptected to bring great opportunity out in terms of HSE functionality. Smart devices of phone or tablet type are being used for on-line work between control center and manufacturing shop floor by virtue of wireless communication. However, those devices are not appropriate for detecting of worker's physical senses such as temperature and pulse. In this paper, we developed a glass type smart device and required funictions for HSE enhancement with the investigation of biometrics technology. Also, required sensors are investigated for the detecting of temperature, pulse and noxious gasses. Smart device of glass type has advantages in that most senses of personnel are gathered around faces, and also it's possible to detect neutral axis of body because the wearing location is fixed. We expect that the proposing HSE product of glass type smart device could contribute the enhancement of the HSE of manufacturing shop floor.

• 정보교육학회논문지
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• 제12권2호
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• pp.131-139
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• 2008

본 연구는 협력적 지식구축을 목적으로 하는 CSCL (Computer-Supported Collaborative Learning) 환경을 이용하여 교육주체간의 협동적 상호작용이 원활히 이루어질 수 있도록 하는 모바일 학급경영지원시스템을 구현하는데 목적이 있다. 이러한 목적을 위해 학급경영과 CSCL, 무선인터넷을 이론적으로 탐색하고 학급경영과 무선인터넷의 관계를 파악하여 학급경영을 지원하는 모바일 학급경영지원 시스템의 설계요소 및 전략을 수립하였다. 이를 기반으로 모바일 학급경영지원시스템을 설계하고 개발하였다.

• 한국정보통신학회논문지
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• 제13권4호
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• pp.753-758
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• 2009

본 논문은 유비쿼터스 헬스케어 시스템을 위하여 생체 정보 단말기 개발에 있어 심음 신호를 기반한 RF-Tag의 하드웨어 구조와 신호처리 방법을 제안한 것이다. 본 연구에서의 RF-Tag는 체온 센서와 심음 검출을 위한 다이나믹 마이크로폰, 측정된 헬스정보를 전송하기 위한 블루투스 통신, 적응 이득제어기로 이루어진 심박 주기 검출 알고리즘으로 구성되어 있다. RF-Tag의 성능 분석을 위해 잡음환경에서 실험하였으며, 그 결과 우수한 성능을 보였다. 본 연구에서 제안한 방법을 u-헬스케어 단말기에 적용한다면, 모바일 환경에서도 실시간적으로 정확한 헬스 정보를 얻을 수 있을 것이라 사료된다.

• 한국HCI학회:학술대회논문집
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• 한국HCI학회 2008년도 학술대회 2부
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• pp.634-639
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• 2008

사회적 컴퓨팅(social computing)의 현상이 Web 2.0 공급사슬(supply chain)의 변화관점에서 새로운 변화의 단계를 맞이하고 있다. Web 2.0 플랫폼을 어떤 형태로 기업 활동에 활용할 것인가 하는 문제제기에 대하여 다양한 기업 활동의 변화사례가 발견되고 있다. 본 논문은 그와 같은 다양한 Web 2.0 환경 확산에 대한 기업 활동의 변화현상 중에서 Web 2.0 플랫폼을 기반으로 한 신제품개발(New Product Development) 사례연구를 통하여 진행한 결과를 반영하였다. 신제품 개발을 위한 플랫폼으로서 Web 2.0 의 협업적 환경을 설계하게 될 경우, 고객의 내재적 요구사항(latent requirement)이 제품개발에 효과적으로 반영될 수 있도록 하는 절차(process)가 기존의 제품개발방법론과 연관되어, 어떤 형태로 적용되고 개선되어 발전될 수 있는가에 대한 경험적 사례를 사례연구방법의 탐험적 경향을 활용하여 살펴보았다. 본 논문에서 다루어졌던 사례는 Web 2.0 플랫폼을 기반으로 사용자 창작 콘텐츠(User Created Content)를 생산하고 증가된 연세대학교 UCC의 양적 팽창에 의해서 수익모델이 발생하는 전형적인 Web 2.0 비즈니스 모델의 구조를 보여주는 경우였다. 본 연구를 통해서 사용자의 내재적 요구사향을 Web 2.0 기술특성을 통해서 참여적 사용자, 혹은 사용자 디자이너들의 적극적인 활동에 의해서 개선 및 구현해 가는 과정을 구체적 개발방법론의 틀로서 정착하려는 시도를 하였다.

• Journal of Forest and Environmental Science
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• 제34권4호
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• pp.352-358
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• 2018

This research paper investigates available options for implementing clean development mechanism (CDM) project in Sarawak state, Malaysia. To investigate economic feasibility, data was collected using survey and field research methods. Also, economic analysis was estimated using net present value (NPV), internal rate of return (IRR) and payback period (PBP) during the 30 years CDM: afforestation and reforestation periods. The result of economic analysis indicated that, the payback period was estimated at 9 years with 18 percent of internal rate of return (IRR). This study also highlighted that CDM biomass supply project have a lot of challenges due to the reduction and exclusion of bio-Solid Recovered Fuel (SRF), supply and demand scenario, and impact of restriction of illegal logging in Malaysia. This study results demonstrate the methodology and guideline for future CDM investment and projects.