• Korean Journal of Medicinal Crop Science
• /
• v.6 no.4
• /
• pp.258-264
• /
• 1998

This study was conducted to establish mass propagation system from seeds of Lavandula angustiolia Mill. Only 4% of dry seeds were germinated when they were incubated in $4^{\circ}C$. Germination rate of stratified seeds for 9 weeks was 15% higher in light than darkness. Soaking with 1000mg/l of $GA_3$ was helpful to overcome the effect of darkness. The optimal temperature for germination was $25^{\circ}C$ for the seeds that were treated with$GA_3$, solution. For the improvement of germination rates, pretreatment of $GA_3$ at 500-2000mg/l showed about 75% of germination, and in the combination treatment of $GA_3$, and BA, germination rate increased by about 10% in the treatment of 1000mg/l $GA_3+10mg/l$ BA compared with the 1000mg/l $GA_3$ treatment. Cold stratification treatment was very effective for seed germination, and over 70% of seeds were germinated when they were incubated in $4^{\circ}C$ for 9-12 weeks. In addition, there was synergic effect on the seed germination subject to stratification and 1000mg/l $GA_3$, treatment for 6 months. In the mixture of vermiculite: peatmoss (1 : 1, v/v), emergence rate was 6.7% in control and 65% in 1000mg/l $GA_3$ treatment, respectively.

• Journal of the Korean Society of Marine Environment & Safety
• /
• v.15 no.4
• /
• pp.329-338
• /
• 2009

Using physiological data which had been already published, we investigated variation of phytoplankton communities due to changes of marine environmental factor at 2 stations of northern Gamak Bay from November 2007 to September 2008. Dominant species (occupied species above 10%) were dinoflagellates 1 species and diatom 11 species. Diatom Skeletonema costatum was observed as dominant species during the periods except in summer (i.e. July and August), especially, which occupied above 90% in December. On the other hand, dominant species during summer were diatom Eucampia zodiacus and Chaetoceros spp., Considering the results of other physiological studies, S. costatum might be non-dominant species during summer by following reasons 1) growth rate of E. zodiacus might be taster than that of S. costatum under the temperature during summer although both S. costatum and E. zodiacus are eurythermal and euryhaline species. 2) Species as E. zodiacus characterized by low affinity with light might have a chance to be dominant with increasing optical transparency due to low suspended solids in July. 3) In aspect of nutrition, species of growth strategist as S. costatum could be dominant in relatively low concentration of phosphate and species of storage strategist as E. zodiacus could be dominant in relatively high concentration of phosphate during summer in this study area. In order to understand the phytoplankton dynamics in detail, the physiological informations about strains isolated from this study area are necessary because physiological conditions are different depending on isolated area.

• Transactions of the Korean Society of Mechanical Engineers
• /
• v.16 no.1
• /
• pp.122-131
• /
• 1992

An expert system is developed which can design the power transmission involute cylindrical gears on the basis of strength and durability. Bending strength, surface durability, scoring, and wear probability are considered as the basis. The basic components of the expert system are knowledge base, inference engine, and working memory. The knowledges in knowledge base are classified hierarchically into the knowledges used in selection of gear type, selection of materials, and determination of K factor and are represented by rules. In the inference engine two inference methods are implemented with the depth first search method. For-ward chaining method is introduced in the selection of gear type and materials and in the determination of K factor. Backward chaining method is introduced in the detailed design of module and face width in accordance with the validation of strength. And inference efficiency is achieved by constructing the part needing a lot of numerical calculations in strength estimation separately from inference mechanism. The working memory is established to save the results during inference temporarily. In addition, design database of past design results is built for consultation during design and knowledge acquisition facility, explanation facility, and user interface are included for the usefulness of user. This expert system is written with the PROLOG programming language and the FORTRAN language in numerical calculation part which interfaced with PROLOG and can also be executed on IBM-PC compatible computer operated by MS-DOS alone.

• Journal of Nuclear Fuel Cycle and Waste Technology(JNFCWT)
• /
• v.11 no.1
• /
• pp.41-54
• /
• 2013

Radionuclide sorption data is necessary for the safety assessment of radioactive waste disposal. However the use of sorption database is often limited due to the accessability. A web-based sorption database program named KAERI-SDB has been developed to provide information on the sorption of radionuclides onto geological media as a function of geochemical conditions. The development of KAERI-SDB was achieved by improving the performance of pre-existing sorption database program (SDB-21C) developed in 1998 and considering user's requirements. KAERI-SDB is designed that users can access it by using a web browser. Main functions of KAERI-SDB include (1) log-in/member join, (2) search and store of sorption data, and (3) chart expression of search results. It is expected that KAERI-SDB could be widely utilized in the safety assessment of radioactive waste disposal by enhancing the accessibility to users who wants to use sorption data. Moreover, KAERI-SDB opened to public would also improve the reliability and public acceptance on the radioactive waste disposal programs.

• Applied Biological Chemistry
• /
• v.26 no.4
• /
• pp.211-216
• /
• 1983

The physicochemical properties of starches isolated from three kinds of waxy ricer were investigated. The average diammeter of Orchal starch granule was 3.6u, and those of Hangang and Baegoon starch granules were 4.8u and 5.6u, respectively. X-ray diffraction patterns of all samples were A types. Optical transmittance of starch suspensions was increased rapidly $60{\sim}62^{\circ}C$, $50{\sim}55^{\circ}C$ and $50{\sim}60^{\circ}C$ in Olchal, Hangang and Baegoon, respectively, and all of them exhibited maximum transmittance $75{\sim}80^{\circ}C$ in range. Initial gelationization temperature by means of amylogram pattern was $60{\sim}61^{\circ}C$, then, Olchal starch had a little higher temperature than others. Raising power of them was $260\sim220$, and then, Olchal starch has a little higher raising power. But, water binding capacity of Baegoon and Hangang were somewhat higher than that of Olchal. Blue values of Olchal and Hangang were similar with 0.13, and that of Baegoon was 0. 14. Alkari numbers of Olchal, Hangang and Baegoon were 4.2, 4.9 and 5.1. The degree of retrogradation of Hangang and Baegoon starch gels were somewhat higher than that of Olchal starch gel.

• Korean Chemical Engineering Research
• /
• v.55 no.3
• /
• pp.332-340
• /
• 2017

This study aims to propose a new optimization-based approach for design and analysis of the stand-alone hybrid energy supply system using renewable energy sources (RES). In the energy supply system, we include multiple energy production technologies such as Photovoltaics (PV), Wind turbine, and fossil-fuel-based AC generator along with different types of energy storage and conversion technologies such as battery and inverter. We then select six different regions of Korea to represent various characteristics of different RES potentials and demand profiles. We finally designed and analyzed the optimal RES stand-alone energy supply system in the selected regions using multiobjective optimization (MOOP) technique, which includes two objective functions: the minimum cost and the minimum $CO_2$ emission. In addition, we discussed the feasibility and expecting benefits of the systems by comparing to conventional systems of Korea. As a result, the region of the highest RES potential showed the possibility to remarkably reduce $CO_2$ emissions compared to the conventional system. Besides, the levelized cost of electricity (LCOE) of the RES-based energy system is identified to be slightly higher than conventional energy system: 0.35 and 0.46 $/kWh, respectively. However, the total life-cycle emission of $CO_2$ ($LCE_{CO2}$) can be reduced up to 470 g$CO_2$/kWh from 490 g$CO_2$/kWh of the conventional systems.

• The Journal of the Korea institute of electronic communication sciences
• /
• v.13 no.2
• /
• pp.357-368
• /
• 2018

For well over 100 years, oil has enabled remote communities to generate electricity and enjoy the benefits of a consistent electrical supply. Relying solely on oil for electricity generation has left island and remote communities exposed to several risks and drawbacks. Oil-based electricity generation is often more expensive and subject to price volatility, which can result in the use of risky fuel hedging strategies. The residents of islands and remote communities express concern over the future impacts of climate change or insist on their opinions for the corresponding action with reduction of carbon emissions. These risks and drawbacks can be overcomed with continuing cost reductions in solar, wind, and energy storage technologies by maker. Reducing costs is not always a straightforward process, relying on more diversely and renewably arranged renewable energy sources led to reduced local construction cost in every situation reviewed in this study. In this paper, a convenient and simple design solution which will facilitate the optimum location and transmission route of renewable energy facility using GIS(Geographic Information System) is proposed. The suggested solutions exercised to the case of geomoon island using GIS and identified by local site survey.

• The korean journal of orthodontics
• /
• v.35 no.5 s.112
• /
• pp.361-370
• /
• 2005

Fiber reinforced composite (FRC) has been widely used in operative and prosthetic fields of dentistry and its use is expanding into the orthodontic field. The purpose of this study was to examine the changes of flexural properties of FRC reinforced with silica glass fiber (FibreKor, Jeneric/Pentron Inc.. Wallingford. U.S.A.) according to the duration of water absorption. Specimens were grouped according to their shape as round and rectangular cross sections, and were immersed in distilled water at room temperature $(23^{\circ}C)$ for 0 hour 1 hour 1 week. 15 days, 1 mouth and 3 mouths. The number of specimens was 5 for each duration and bending test was done using a torque tester The flexural stiffness after 24 hour water immersion was reduced to 59% for round specimens and 25% for rectangular specimens and after 3 mouths of water immersion it was reduced to 29% and 19% stiffness of the 0 hour-specimen respectively Yield flexural moment after 24 hour water immersion was reduced to 45%for round specimens and 76% for rectangular specimens and after 3 months of water immersion it was reduced to 29% and 60% stiffness of the 0 hour-specimen respectively Ultimate flexural moment after 24 hour water immersion was reduced to 35% for round specimens and 76% for rectangular specimens and after 3 mouths of water immersion it was reduced to 25% and 37% stiffness of 0 hour-specimen respectively. Those results suggested that the flexural stiffness of FibreKor decreased greatly after initial water immersion. Consequently, further research for the maintenance of strength against water will be necessary

• Proceedings of the Korean Society of Broadcast Engineers Conference
• /
• 2004.11a
• /
• pp.17-20
• /
• 2004

가정 내에 방송과 총신을 통합하여 제공하기 위한 방법으로서 수동광가입자망(Passive Optical Network)이 제안되고 있다 이를 구현하기 위해 여러 방식들이 연구되고 있는데 크게는 방송과 통신에 각기 다른 파장을 이용하는 방식과, 이들을 시간 다중화 하여 한 개의 과장으로 송신하는 방식으로 나눌 수 있다. 또한 동신에 이용하는 과장의 경우 각 가입자에게 다른 파장을 적용하는 WPON 방식과 모든 가입자에게 한 개의 파장만을 이용하되 시간영역에서 다중화하고 이터넷 프로토콜을 적용하는 EPON 방식으로 구분할 수 있다. WPON의 경우 EPON에 비해 수월하게 광대역 서비스를 할 수 있는 장점이 있으나, 각 가입자 과장의 제어 및 관리가 복잡하며, 고비용을 요구한다. 반면 EPON의 경우 채널의 효율성은 극대화할 수 있으나, 동시 이용자가 많을 경우 전송 속도가 하락한다. 한편, 방송과 통신을 통합한 채널의 특성을 살펴보면 가입자 방향으로의 하향 신호의 양이 중양국 방향으로의 상향 신호의 양에 비해 훨씬 많은 비대칭 구조이다. 따라서 본 연구에서는 이러한 채널 특성에 맞도록 하향 전송에는 WPON의 구조를 이용하고, 상향 전송에는 EPON의 구조를 적용하는 새로운 구조의 광가입자망을 제안하였다. 제안된 구조에 적합한 MPCP (Multi-Point Control Protocol) 프로토콜을 제시하고, 가입자 장치의 여러 종속 신호를 다중화하고 전송할 수 있는 ONU (Optical Network Unit)의 구조를 제안하였다. 또한 이러한 구조를 갖는 W-EPON 테스트베드를 구현하고 전송 시험을 통해 제시된 구조의 적합성을 측정한 결과를 보인다.4 Textual format) 파일을 생성한다. 또한, 콘텐츠 전송 및 저장의 효율성을 위해 이진 포멧인 IPMP화된 MP4 파일을 생성할 수 있다.으로써, 에러 이미지가 가지고 있는 엔트로피에 좀 근접하게 코딩을 할 수 있게 되었다. 이 방법은 실제로 Arithmetic Coder를 이용하는 다른 압축 방법에 그리고 적용할 수 있다. 실험 결과 압축효율은 JPEG-LS보다 약 $5\%$의 압축 성능 개선이 있었으며, CALIC과는 대등한 압축률을 보이며, 부호화/복호화 속도는 CALIC보다 우수한 것으로 나타났다.우 $23.87\%$($18.00\~30.91\%$), 갑폭 $23.99\%$($17.82\~30.48\%$), 체중 $91.51\%$($58.86\~129.14\%$)이였으며 성장율은 사육 온도구간별 차는 없었다.20 km 까지의 지점들(지점 2에서 지점 6)에서 매우 높은 값을 보이며 이는 조석작용으로 해수와 담수가 강제혼합되면서 표층퇴적물이 재부유하기 때문이라고 판단된다. 영양염류는 월별로 다소의 차이는 있으나, 대체적으로 지점 1과 2에서 가장 낮고, 상류로 갈수록 점차 증가하며 지점 7 상류역이 하류역에 비해 높은 농도이다. 월별로는 7월에 규산염, 용존무기태질소 및 암모니아의 농도가 가장 높은 반면에 용존산소포화도는 가장 낮다. 그러나 지점 14 상류역에서는 5월에 측정한 용존무기태질소, 암모니아, 인산염 및 COD 값이 7월보다 다소 높거나 비슷하다. 한편 영양염류와 COD값은 대체적으로 8월에 가장 낮으나

• Journal of Life Science
• /
• v.20 no.1
• /
• pp.27-32
• /
• 2010

Ultraviolet-B (UVB) radiation induces the formation of reactive oxygen species (ROS) and depletes stores of cellular antioxidants. Fucoidan, polysaccharides containing L-fucose and sulfate ester groups, are constituents of brown algae. In this study, the protective effects of fucoidan on UVB-induced oxidative stress in cultured human skin fibroblast HS68 cells were assessed. Pretreatment with fucoidan significantly reduced malondialdehyde (MDA) content in a dose-dependent manner. With fucoidan pretreatment at a dose of $100\;{\mu}g/ml$, the level of intracellular glutathione was increased by 21.5%, compared to UVB irradiation alone. Fucoidan significantly reduced UVB-induced ROS generation by 40.1% and 68.4% at 10 and $100\;{\mu}g/ml$, respectively, compared to UVB irradiation alone. The positive staining rates of senescence-associated $\beta$-galactosidase were reduced by 23.1% and 16.4% with 10 and $100\;{\mu}g/ml$ of fucoidan, compared to UVB irradiation alone. Fucoidan may exert a photoprotective effect against UVB radiation-induced oxidative stress.