• Journal of KIISE:Computing Practices and Letters
• /
• v.14 no.1
• /
• pp.52-62
• /
• 2008

As various types of embedded devices are widely used, a technology that supports reuse of applications on multiple platforms is needed in order for time-to-market development of the applications. The interface middleware is one of such technology and it hides platform dependency from application programmers. Existing interface middleware such as the MT project, Xenomai and Legacy2linux have limitation in that the APIs provided by each of these middleware are fixed to a specific operating system, and the middleware does not provide dynamic expansion of its API set. In this paper, we propose a middleware which hides operating system dependencies and enables porting of applications on various operating systems. In addition, the middleware has scalable structure so that it is suitable for resource-limited embedded systems. The overhead of the middleware, i.e., the time delay occurred by the middleware is between $0.3{\mu}sec\;and\;5{\mu}sec$ in most cases. We believe that the amount of overhead is reasonable and does not hurt the performance of applications.

• Journal of the Korea Society for Simulation
• /
• v.22 no.4
• /
• pp.57-66
• /
• 2013

The needs for reusable 3D visualization tool has been being raised in various industries. Especially in the defense modeling and simulation (M&S) domain, there are abundant researches about reusable and interoperable visualization system, since it has a critical role to the efficient decision making by offering diverse validation and analyzing processes. To facilitate the effectiveness, states-of-the-arts M&S systems are applying VR (Virtual Reality) or AR (Augmented Reality) technologies. To reduce the work burden authors design a collaborative visualization environment based on a commercial game engine Unity3D. We define the requirements of the warfare simulation by analyzing pros and cons of existing tools and engines such as SIMDIS or Vega, and apply functionalities of the commercial game engine to satisfy the requirements. A prototype has been implemented as the collaborative visualization environment of iCAVE at KAIST, which is a facility for immersive virtual environment. The facility is intraoperative with smart devices.

• Proceedings of the Korean Vacuum Society Conference
• /
• 2012.08a
• /
• pp.179-179
• /
• 2012

국내에는 나노 분말 제조를 위한 RF 열플라즈마 시스템 제조 기술이 확보되어 있지 않고, 또한 나노 파우더 제조를 위한 공정 기술 역시 외국 업체에 전적으로 의존하고 있다. 본 연구에서는 나노 분말 제조를 위한 RF 열 플라즈마 토치 시스템 개발과 고품질의 나노 파우더 합성 공정 기술을 확립하여 필요 기관에 제공하는데 있다. 80 kW RF Plasma torch system의 설계 및 제작을 위해 플라즈마 Simulator인 CFD-ACE+를 이용하여 플라즈마 토치 및 반응로 내의 온도 분포, 유체 유동, 열전달 등의 해석을 통해 플라즈마 토치 및 반응로의 반경 및 길이, 구조의 설계 값을 도출하여 반응로를 설계하여 RF 파워, RF 플라즈마 토치(Torch), 반응기(Reactor), 사이클론(Cyclone), 포집부(Collector), 열교환기 및 진공배기 시스템으로 구성하였다. Si 나노 소재의 경우, 이차전지 음극재에 적용이 가능한 대표적인 소재로서 높음 비용량과 충/방전시 부피팽창을 감소시킬 수 있어 이차전지의 고용량 구현을 위해서는 가장 중요한 소재중 하나로 많은 관심 재료로 평가 받고 있다. 따라서 본 연구에서는 상용화된 Si 원료 powder를 사용하여 고상 분체 공급 장치를 통하여 고온의 플라즈마를 통과시켜 기상화 및 결정화과정을 통해 Si 나노분말을 제조하였다. 공정 변수로서 공정압력 및 플라즈마 power, Gas의 변화량에 따른 나노 분말의 제조 특성에 대한 실험을 진행한 후 제조된 나노 분말을 비표면적측정(BET) 및 SEM 측정 결과 분석을 통하여 시스템 특성을 파악하였으며 제조된 Si 나노 파우더는 이차전지 음극재로서 770 mAh/g의 용량과 93%@50 cycle 수준의 유지율을 나타내었다.

• Resources Recycling
• /
• v.16 no.1 s.75
• /
• pp.37-43
• /
• 2007

It was studied to prepare anhydrous magnesium chloride which could used as the raw material of a fused salt electrolysis of magnesium by dehydration of magnesium chloride hydrate. The dehydration was carried out in a tube furnace at $350{\sim}580^{\circ}C$. It was confirmed that magnesium chloride hydrate was oxdized to magnesia through the dehydration in ambient atmosphere, but anhydrous magnesium chloride could be obtained in hydrogen chloride gas atmosphere. And the crystallity of the product increased with increasing temperature and time of dehydration. All of the un-reacted hydrogen chloride gases which were generated during the dehydration in hydrogen chloride gas atmosphere could be recovered as hydrochloric solution, and it could be reused for chlorination of magnesia to prepare magnesium chloride hydrate.

• The Journal of Society for e-Business Studies
• /
• v.9 no.1
• /
• pp.61-81
• /
• 2004

Learning Contents Management System(LCMS) manages the contents and the process of teaming by incorporating the both in a flexible system to help learners to be able to utilize them efficiently. The e-Learning comprises all types of educations based on electronic technologies as well as the Web. The existing e-Learning system is a simple information system providing Web based contents, therefore, it cannot support flexibility for both learners and teachers. The core part of the e-Learning system should be a remote education system which creates bilateral response between the learners and teachers, by providing substantial contents based on the LCMS. In this paper, a new e-Learning system is constructed with reusable modules generated by Component-Based software Development(CBD). Furthermore, creates new contents groups and enables to develop learning courses utilizing the Learning Objects. And also, observing the SCORM standard, lecture contents are designed and prepared to support learners Learners are supported to produce profiles which enables themselves to manage, measure, and evaluate their own capabilities, so that they can develop themselves properly in accordance with their levels, build prototypes for self development. Also a system that comprises all these individual components is suggested.

• The Transactions of the Korea Information Processing Society
• /
• v.3 no.1
• /
• pp.144-152
• /
• 1996

Recently, as the demands for radio spectrum are growing and the number of cell sites is increasing rapidly, the spectrum engineering plays an important role in estimating frequency sharing and reuse. The radio propagation analysis is essential in the basic technology of radio network design such as deciding the service area and selecting the position of the base station. But, domestic propagation environment in which mountainous region is occupying over 70% of our terrain does not allow us to apply foreign studies which are deduced in highly different environments. Therefore, we need to have our propagation analysis system derived from our own terrain condition. In this paper, we propose the propagation prediction model which issuitable toour propagation environment, and also usinghis model, we implement thesimulator based on GIS(Geographic Information System)which can be applied to both spectrum engineering and radio propagation analysis. We showed that this simulator can well be applied to frequency assignment, propagation network design as well as other radio services. Considering the results of our analysis, we could guarantee the standard deviation of error between the measured data and predicted results as 5 to 7 dB.

• Resources Recycling
• /
• v.21 no.4
• /
• pp.76-85
• /
• 2012

Fluorescent lamps generally involve mercury within their lamp bulbs. Thus if the lamps are disposed as they are, it might cause environmental pollution. On the other hand, as the life of the lamps depends on the degradation of the discharge performance, the fluorescent substance composing the fluorescent substance coating can be recycled by reusing them as the recycled fluorescent substance. Also, the glass material composing the glass bulbs can be reused. The range of search was limited in the open patents of USA (US), European Union (EU), Japan (JP), Korea (KR) and SCI journals from 1977 to 2011. Patents and journals were collected using key-words searching and filtered by filtering criteria. The trends of the patents and journals was analyzed by the years, countries, companies, and technologies. Recovery method of metals from spent fluorescent lamps is mainly the focus on the recovery of precious metals using acid treatment and, detoxification technology is related with controlling process of mercury using a filter system.

• KIPS Transactions on Computer and Communication Systems
• /
• v.2 no.5
• /
• pp.217-222
• /
• 2013

Return-Oriented Programming(ROP) is an advanced code-reuse attack like a return-to-libc attack. ROP attacks combine gadgets in program code area and make functions like a Turing-complete language. Some of previous defense methods against ROP attacks show high performance overhead because of dynamic execution flow analysis and can defend against only certain types of ROP attacks. In this paper, we propose Indirect Branch Target Address Verification (IBTAV). IBTAV detects ROP attacks by checking if target addresses of indirect branches are valid. IBTAV can defends against almost all ROP attacks because it verifies a target address of every indirect branch instruction. Since IBTAV does not require dynamic execution flow analysis, the performance overhead of IBTAV is relatively low. Our evaluation of IBTAV on SPEC CPU 2006 shows less than 15% performance overhead.

• The Korean Journal of Pesticide Science
• /
• v.11 no.4
• /
• pp.276-280
• /
• 2007

In order to select the coating materials to perilla seed for reducing endosulfan residue greenhouse soil, this study was conducted to develop seed coating method and materials and also to evaluate the effects of seed coating on germination and color contrast between soil and perilla seed for convenient sowing work. Talc and kaoline were selected as seed coating materials because easy coating and better color contrast than shell powder or lime. Water was more effective on germination compared to alcohol, com oil and spray sticker as adhesives for seed coating.

• Journal of Korean Society of Environmental Engineers
• /
• v.39 no.4
• /
• pp.214-219
• /
• 2017

We analyzed the water quality of first flush and rainfall runoff from a building rooftop, and investigated the removal of suspended solids (SS) in first flush using various media to develop a first flush filtration system. Particle size distribution exhibited most of particles in first flush from the rooftop ranged from 10 to 30 ${\mu}m$. SS concentrations maxed in 10~20 min and decreased afterwards. Dissolved organics and inorganic materials in runoff also showed highest levels in first flush (10 min). Filtration tests using anthracite (AC), polyurethane (PU), polypropylene (PP) showed about 50% of SS removal during the first 10 min operation, but the removal rates dramatically decreased after 20 min of filtration. Based upon the results from rinse and run cycle tests, only AC could achieve nice cycles without distinct decease of SS removal. SS removal rates increased with higher depth of media bed and lower flowrate. The system achieved over 50% of SS removal with a media depth of 30 cm and flowrate < 12 L/min.