• Polymer(Korea)
• /
• v.25 no.5
• /
• pp.665-670
• /
• 2001

The solvent extraction of polyethylene glycol (PEG) by ethanol has been studied for the powder injection molded compacts of Sr-ferrite/PEG/carnauba wax/HDPE. The extraction rate of PEG is sensitively proportional to the solvent temperature whereas it is inversely proportional to the contents of PEG, the molecular weight of PEG. and the specimen thickness. The high extraction rate of PEG is achieved under the following conditions: solvent temperature of $70^{\circ}C$, PEG contents of 30%, and PEG molecular weight of 400 g/mol. In the early stage of solvent extraction, the non-linear relationship between the extraction rate and the square root of the extraction time indicates that the extraction of PEG does not follow the Fickian behavior. At extraction times longer than 180 min. however, the extraction of PEG follows the Fickian behavior. The extraction fate of PEG by ethanol is about$1.0{ imes}10^{-6}g/cm^2sec$ enough for common applications.

• The Magazine of the Society of Air-Conditioning and Refrigerating Engineers of Korea
• /
• v.30 no.9
• /
• pp.17-26
• /
• 2001

최근 국제적인 여건과 사회적인 상황이 급변하여 대량생산-대량소비지향으로 인한 폐기물의 대량방출사회에서 지구환경보전을 중시하는 사회로 전환되어 가고 있다. 지구환경의 보전을 위하여 다양한 분야에서 각종 논의가 진행되고 있는 가운데 건축분야에서도 지구기후변화에 영향을 미치는 것으로 알려져 있는 이산화탄소배출의 억제와 폐기물 삭감 등에 대한 관심이 증대되고 있다. 최근 관심이 집중되고 있는 건축물의 장수명화와 리모델링도 이러한 움직임과 궤틀를 같이 하는 것이다. 물론 리모델링은 신축시장의 급감에 따른 대체시장으로서 검토되고 있는 측면이 더 크게 작용하고 있는 것도 사실이지만, 그동안 신축에 대한 집중적인 투자에 중점이 두어져 재고건축물에서 간과해 왔던 유지관리와 리모델링에 대한 중요성 인식이 결부되어 있다고 보여진다. 사실 지금까지 리모델링이 전혀 이루어지지 않았던 것이 아니라 일반건축물 부문에서는 상당부분 이루어져 왔으며, 공동주택 부문에서도 극소수 이루어져 왔다. 리모델링에 대한 정의와 개념을 어떻게 보느냐에 따라 많은 차이가 있을 수 있지만, 리모델링은 건축물 또는 외부공간의 성능 및 기능의 노후화나 진부화에 대응하여 보수, 수선, 개수, 부분증축 및 개축, 제거, 새로운 기능추가 및 용도변경에 이르는 광범위한 행위를 포함한다. 리모델링을 통하여 건축물의 성능을 유지하거나 향상시켜 쾌적하고 건강한 건축물의 재고 를 구축함과 아울러 건강한 지역환경을 조성하여 국민생활의 질적인 향상을가져옴으로써 환경을보전하 고 자원낭비를 줄여 지속가능한 건축물과 사회를 만들어 갈수있도록 하는 것이다. 건축물에서 리모델링을 하게 되는 동기는 시간이 흘러 물리적인 측면이나 기능적인 측면에서 노후화가 발생하거나 기능적인 요구가 변화함에 따라 건설당시의 성능이나 기능유지가 어렵거나 건설당시의 기능만으로는 요구조건을 만족함 수 없기 때문에 건설 당시의 수준을 유지하거나 새로운 요구에 적합하도록 향 상시키기 위해서는 물리적 또는 기능적인 개선이나 개량이 필요하기 때문이다. 물리적인 개선이나개량을위하여 중요한것은건축 물을 구성하는 자재나 부품의 수명문제이다. 수명의 길이차이가 건축물의 리모델링에 영향을 주고 있을 뿐만 아니라 서로 다른 수명의 자재나 부품의 접합상태가 리모델링 공사에 많은 영향을 미치게 된다. 리모델링 공사가 신축공사의 70-80% 정도의 공사비가 소요되기 때문에 리모델링 공사가 어렵다는 업체의 불만은 바로 이러한 점을 극명하게 드러내는 좋은 사례이다. 본 고는 이러한 측면에서 건축물의 장수명화를 근간으로 한 설비의 리모델링을 용이하게 하기 위한 건축 계획 및 구법에 대하여 고찰하고자 한다. 그리고 본 고는 기존건축물의 설비자체의 보수나 개수를 용이하게 하는 것에 초점이 맞추어진 것이 아니라 건축설계 및 시공시에 향후 설비부분을 용이하게 개.보수할 수 있도록 배려하는 측면을 중심으로 설명하였다.

• Korean Journal of Plant Resources
• /
• v.13 no.1
• /
• pp.54-60
• /
• 2000

To investigate the effects of Oenanthe javanica sap (OJS) on plasma lipid composition, several biochemical parameters such as total cholesterol, HDL-cholesterol, triglyceride, GOT, GPT and malodialdehyde were compared in the four groups as follows: a normal group with basal diet, a control group with high-fat diet, a treatment group with high-fat diet and OJS 1 ml/kg, and the other treatment group with high-fat diet and OJS 1.5 mg/kg. In addition, the body weight change, food intake and food efficiency ratios were measured. In this study, treatment groups decreased plasma total cholesterol levels.

• Journal of the Institute of Electronics Engineers of Korea SD
• /
• v.41 no.5
• /
• pp.107-114
• /
• 2004

In this paper, we present the architecture design of CDMA/TDMA modem chipset for wireless telemetry system. The wireless telemetry system a measuring data collecting system from many RTs(Remote Terminal) installed at the specific area using wireless communication technology. It consists of CU single CU (Central Unit) for collecting data and a large amount of RTs for transmitting the measuring data. We propose the hardware architecture of the modem for RT and CU. We also design those modem using Verilog HDL and synthesis them using Synopsys$^{TM}$ CAD tool. The modem of RT is implemented with 27K gates and that of CU is implemented around 220k gates using 0.6${\mu}{\textrm}{m}$ CMOS standard cell. The proposed system is implemented and tested using Altera$^{TM}$ FPGA.PGA.

• Journal of the Korea Academia-Industrial cooperation Society
• /
• v.11 no.12
• /
• pp.5058-5071
• /
• 2010

International standard is the documents that is constructed based on general and common characteristics of software. Thus, it is necessary to consider the characteristics of product and optimize the evaluation method by using related standard to adapt to some specific knowledge information security products. Also, because rapid development of software field was obliged to change the international standard, the content and construction of standard has changed, it is necessary to construct the evaluation method with this change. In this paper, we developed the evaluation model that can support the quality enhancement by evaluating the quality level and extracting the improvement method of firewall. For this, we surveyed and analyzed the trend and the technical elements of firewall and considering the general quality requirements and unique quality requirements, and proposed the quality evaluation model and method.

• 한국정보교육학회:학술대회논문집
• /
• 2010.08a
• /
• pp.243-249
• /
• 2010

2007 revised curriculum in primary schools by the educational programming should be carried out due to a number of practical constraints have been performed well. Elementary education program conducted by the EPL and Scratch Programming for haneunge was not long after the development of intuitive interface and blocks created using the syntax, contains multimedia elements, such as the benefits that can create artifacts due to the elementary education program is appropriate for. The researcher targeted the school for a semester, 4th year 12 weeks based on the results of scratch programming, programming by way of the Plan and the training and the results were analyzed. Scratch programming to increase student interest and enhance creativity and Formal help cultivate the scientific attitude can give you results. Scratch Programming for Elementary EPL Education is an effective lead of the students' prior knowledge or interest in sex by level of achievement because of the variation to allow individual learning needs to organize a program of study. And results in the production of sufficient thinking ahead and given time to discuss the purpose of education and programming will need to be alive.

• Current Industrial and Technological Trends in Aerospace
• /
• v.7 no.2
• /
• pp.68-75
• /
• 2009

Up to date, demands for satellite including communication are increasing. Advanced countries on space technology such as America, Russia, Europe, Japan, China and so on already had secured launch vehicle technology which can insert a large class satellite to proper orbit. The introduction of technologies on the large class launch vehicle including propulsion system is difficult due to the utilization possibility for defensive reason. The acquisition of indigenous technical expertise on the design and manufacture of valves is believed to contribute to the successful local development of valves for propulsion systems and to significant improvement of local technical level of valve design and development. This paper introduces current status of valves developed by other countries as well as valves developed in domestic. The Developed technology of valves may underlie the construction of engine control systems required for the reliable operation of the KSLV-II engine system and propulsion system.

• Journal of the Korea Academia-Industrial cooperation Society
• /
• v.11 no.9
• /
• pp.3204-3209
• /
• 2010

This paper suggested the future technologies of biometrics system by using Delphi method. The level of technology were also evaluated. The group for the Delphi analysis consisted of 30 experts involved in biometrics. This study also suggested the 10 future core technologies of biometrics system including Body-signal DB technology and Bio-signal analysis technology, etc. From the technological importance point of view, several technologies were suggested as critical ones including the manufacturing technology of semiconductor micro-sensor and bio-sensor, etc. This research also forecasted the realization time of each technology and gave shape the detail goal performances. This research will be able to contribute to deciding the priority order and setting the direction of biometrics R&D planning.

• 한국HCI학회:학술대회논문집
• /
• 2009.02a
• /
• pp.572-578
• /
• 2009

This paper introduce a structure of haptic collaboration system over high resolution tiled-display, and proposes a object based efficient display method for high resolution display in integrated system. in addition, a modeling of visualization system is defined to evaluate performance of the proposed method. Both haptic system and tiled-display system have requirements of computational power. A haptic device is unstable if haptic rendering rate is less than 1kHz. A requirement of tiled-display systems is frame rate of display. It requires update of 30 frame fer sec. If we use these systems independently, we can satisfy each requirements. However, if we integrate two systems, performance of entire system significantly decreases because of lack of resources. In this paper, therefore, we propose a segmentation-based display method for ultra high resolution display in integrated system. The proposed method reduces redundancy of display data by reducing a display rate of static objects. Finally, a modeling of visualization system is defined to evaluate performance of the proposed method.

• Korean Journal of Construction Engineering and Management
• /
• v.6 no.3 s.25
• /
• pp.100-110
• /
• 2005

As construction projects are getting more complex and larger in size, the amount of information is increased exponentially, which requires information management systems to accumulate as-built information throughout the project life-cycle. Particularly, a daily report system is very important, since it helps them keep track of various as-built information at the most detailed level. However, there have been many problems with daily reporting since its process is time-consuming and contains a lot of redundancies and ambiguities. Therefore, the objective of this research is to improve a process of collecting as-built information and managing daily report. To do so, this research developed a to-be process model and a daily report system. The daily report system developed in this research consists of interactive task generator and daily report management modules. The system has been successfully implemented in a real world construction project. The system development processes including process analysis, information models and system features are described along with discussions on the results and improvements.