• Journal of the Korean Wood Science and Technology
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• v.42 no.6
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• pp.714-722
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• 2014

In the previous study, a variety of wood-based panels was thermally decomposed to manufacture carbonized boards that had been proved to be high abilities of insect and fungi repellence, corrosion and fire resistant, electronic shielding, and formaldehyde adsorption as well as sound absorption performance. Based on the previous study, carbonized medium density fiberboard (c-MDF) was chosen to improve sound absorption performance by holing and sanding process. Three different types of holes (cross shape, square shape, and line) with three different sanding thickness (1, 2, and 3 mm) were applied on c-MDF and then determined sound absorption coefficient (SAC). The control c-MDF without holes had 14% of SAC, however, those c-MDFs with holes had 16.01% (square shape), 15.68% (cross shape), and 14.25% (line) of SAC. Therefore, making holes on the c-MDF did not significantly affect on the SAC. As the degree of sanding increased, the SAC of c-MDF increased approximately 65% on sanding treated c-MDFs (21.5, 21.83, and 19.37%, respectively) compared to the control c-MDF (13%). Based on these results, composite sound absorbing panel was developed with c-MDF and MDF (11 mm). The noise reduction coefficient of composite sound absorbing panel was 0.45 which was high enough to certify as sound absorbing material.

• Proceedings of the Korea Water Resources Association Conference
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• 2007.05a
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• pp.1033-1037
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• 2007

하천의 수위를 유지하거나 농업용수를 취수할 목적으로 현재 국내에 약 18,000개 정도의 크고 작은 보가설치되어 있다. 이러한 보 중에는 극히 일부에 어도와 같은 생태통로가 인위적으로 설치되어 있지만 전체적으로는 매우 미미한 수준이다. 더욱이 도시 인구 집중황 따른 도심부의 확대로 인한 농경지의 도시화, 경작 방식의 변화에 의한 논농사 위주에서 비닐하우스 단지로의 변화와 같은 토지이용의 변화, 대형 저수지의 축조／양수장 설치 등에 따른 취수 시설물의 통합, 시설의 노후화 등으로 매년 50-150개 정도의보가 폐기되고 있다. 그러나 이렇게 폐기되는 보는 하천에 그대로 방치되어 하천생태통로의 단절, 수질악화, 수변 서식처악화 등의 문제를 지속적으로 야기시키고 있다. 연구지역은 경기도 고양시 곡릉천 곡릉2보로 선정하여 보 철거전 과 보 철거 후의 모니터링을 통한 수질분석을 시행하였다. 곡릉2보는 과거 취수용 보로 이용되었으나 주변지역 토지이용 변화로 용도를 상실한 보이다. 보 철거 전에는 보로 인한 보 상류 지역에 퇴적물이 쌓이면서 정체구역이 생기고 부유물질이 많아지면서 수질 악화를 초래하는 것으로 나타났다. 그러나 보 철거 후에는 화학적으로 상류 하류지점에서 SS 및 BOD의 농도가 감소하여 전체적으로 수질향상에 기여한 것으로 나타났다. 보 철거에 따른 수질분석에 대한 연구는 아직 진행 단계에 머물러 있으며, 그 주변에 대한 상세한 이론은 아직 미미하다. 따라서 현재 국내외 보의 현황 및 보 철거 기술을 조사하고, 우리나라의 조건이 다른 보를 선정하여 하천의 보가 수질에 미치는 영향을 정량적으로 분석함으로써, 향후 우리나라의 보 관리방안의 방향을 제시하는데 도움이 되고자 한다.를 제시하고 있다. 미국의 경우는 이러한 가이드라인을 실제로 현장에 적용하고 있으며 조성효과가 정성적으로 검증되었고 정량적인 관계 도출을 위한 연구가 지속적으로 진행되고 있다. 국내의 경우 수질개선 및 생태서식처 조성, 하천환경을 개선하기 위한 관련 정책이 꾸준히 제시되고 있다. 한 예로 정부에서는 수변구역을 지정 고시하여 상수원으로 유입되는 비점오염물질을 저감하고 생태서식처를 조성함으로써 양질의 상수원과 건전한 생태계를 확보하기 위한 제도를 시행 중이다. 수변 구역의 범위는 한강수변구역의 경우 약 $500{\sim}1,000m$로 설정되어 있으나 아직까지는 관리적 성격이 강하며, 향후에는 구체적인 조성방안이 요구된다. 본 연구에서는 한강 수변구역 내에 미국의 가이드라인에서 제시하는 수변완충지대의 물리적 조건과 국내 지역 토착식생을 적용하여 시험완충지대를 조성하였고, 실험조건 하에서 그 효과를 정량적으로 분석 검증한 결과와 외국사례를 분석하여 국내여건에 맞는 수변완충지대 조성 가이드라인(안)을 제시하였다.EX>$\ulcorner$세종실록$\lrcorner$(世宗實錄) $\ulcorner$지리지$\lrcorner$(地理志)와의 비교를 해보면 상 중 하품의 통합 9개소가 삭제되어 있고, $\ulcorner$동국여지승람$\lrcorner$(東國與地勝覽) 에서는 자기소와 도기소의 위치가 완전히 삭제되어 있다. 이러한 현상은 첫째, 15세기 중엽 경제적 태평과 함께 백자의 수요 생산이 증가하자 군신의 변별(辨別)과 사치를 이유로 강력하게 규제하여 백자의 확대와 발전에 걸

• 한국약용작물학회:학술대회논문집
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• 2010.10a
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• pp.381-381
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• 2010

2010년 5월 중 서울 약령시와 서울시내 대형마트에서 유통 중인 약용버섯 및 식용버섯류 16품목 92건 대상으로 중금속(비소, 카드뮴, 납, 수은) 모니터링을 실시하였다. 식품의약품안전청에서 고시한 생약의 잔류오염물질 허용기준 및 시험방법에 따라 실험하였으며, 유통 버섯류의 중금속 함유실태를 파악하고, 버섯의 안전성 기준 제정을 위한 기초 자료를 제공하고자 본 실험을 실시하였다. 새송이버섯 등 생버섯 7종 15건에 대한 중금속 검사 결과 비소 0.01~0.26 mg/kg, 카드뮴 0~0.10 mg/kg, 납 0~0.03 mg/kg, 수은 0~0.007 mg/kg 으로 중금속 함유량이 낮았다. 상황버섯 등 11종 77건의 건조되어 식용 및 약용으로 사용되는 버섯류 중 노루궁뎅이버섯은 4건 중 2건(50.0 %)에서 카드뮴이 0.32~0.82 mg/kg으로 한약재 기준 대비 높게 검출되었으며, 상황버섯은 15건 중 5건(33 %)에서 카드뮴 0.58~0.85 mg/kg, 표고버섯은 9건 중 3건에서 카드뮴 0.42~0.74 mg/kg, 운지버섯 5건 중 1건(20.0 %)에서 1.66 mg/kg, 영지버섯 16건 중 2건(12.5%)에서 수은 0.415 mg/kg과 카드뮴 0.66 mg/kg이 분석되었다. 특히 아가리쿠스버섯은 10건 중 10건(100.0 %)에서 카드뮴(10건) 1.49~7.35 mg/kg, 수은(9건) 0.202~0.505 mg/kg으로 높은 유해중금속 함유량을 보이는 것으로 조사되었다.

• Korean Journal of Medicinal Crop Science
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• v.3 no.1
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• pp.25-29
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• 1995

In order to obtain the basic information on cross breeding of peony, the growth and floral characteristics were investigasted for local collected strains in main cultvation area in Korea. Local peony strains were classified by early emergence lines and late emergence lines according to the emergence date. Flower color of single-petaling flower was varied with red, pink and white, on the other hand, red+red, pink+white, pink+red and pink+pink in double-petaling flower. Number of pistil of the most local peony strains was 3-4/flower, number of stamen was varied from 0 to more than 200 ea/flower, classifing by 4 groups according to the diameter of flower. Most of the cross combinations showed the cross comptibility, and number of follicle was 3-5 ea/flower, average number of seed was 15.6 ea/follicle, seed size was grouped : by small grains with less than 10g, medium grains with 10-15g and large grains with more than 15g of 100 seed weight.

• Journal of the Korean GEO-environmental Society
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• v.18 no.7
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• pp.13-20
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• 2017

Soil nailing is ground reinforcement method using the shear strength of ground and the pullout shear resistance force of nail. It is mainly used for reinforcement of cut slopes, earth retaining structures and retaining walls, etc. It may be designed considering the pullout resistance of nail in the case of earth retaining structure and retaining wall, but it should be designed considering not only pullout resistance but also shear and bending resistance in the case of slope. However, conservative designs considering only pullout resistance are being done and most of the studies are about increasing pullout resistance by improving of material, shape and construction method of nail. Actually, Shear bending deformations occur centering on the active surface in ground reinforced with the nail. The grout with relatively low strength is destroyed and separated from the reinforcing material. As a result, the ground is collapsed while reducing the frictional resistance rapidly. Therefore, it is necessary to develop the method to increase the shear resistance while preventing separation of nail and grout body. In this study, an experimental study was conducted on new soil nailing method which can increase shear resistance by forming protrusions through pressurized grouting after installing a packer on the outside of deformed bar.

• Journal of the Korean Crystal Growth and Crystal Technology
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• v.25 no.5
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• pp.218-224
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• 2015

Recently, removing methods of red tide has been attempted by filtering the organisms using the ceramic porous bodies. However, the marine biofouling could be developed on the surfaces of porous ceramic body after use for more than one month, and it might decrease the function of the specimen. In this paper, a method of inhibiting marine biofouling by changing the physical properties or surface-modification of ceramic porous body was studied. After experiment with six different ceramic porous bodies, it was found that the specimen of lower porosity and water absorption showed the least amount of biofouling. In addition, by increasing the surface roughness with silica particles bonded to the surface of specimen, the amount of biofouling caused by large marine life such as barnacle and mussel could be decreased. On the other hand, when the surface of specimen was coated and fused by glass powder, the amount of biofouling was rather increased. This might be due to eluted inorganic ions from the glass which can promote the growth of the microorganism. In conclusion, the environmental-friendly methods to reduce the amount of marine biofouling, such as controlling the physical properties and the surface roughness of the porous ceramics, can be possible without the use of dangerous substances. So it is expected for the results obtained to be applicable to a marine structure.

• Journal of the Korean Vacuum Society
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• v.17 no.4
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• pp.270-277
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• 2008

Vacuum is any air or gas pressure less than a prevailing pressure in an environmental or, specifically, any pressure lower than the atmospheric pressure and is used by a wide variety of scientists and engineering - including clean environment, thermal insulation, very long mean free path, plasma, space simulation[1]. The space environment is characterized by such a severe condition as high vacuum, and very low and high temperature. Since a satellite will be exposed to such a space environment as soon as it goes into its orbit, space environmental test should be carried out to verify the performance of the satellite on the ground under the space environmental conditions. A general and widely used method to simulate the space environment is using a thermal vacuum chamber which consists of vacuum vessel and thermally controlled shroud. As indicated by name of vacuum chamber, the vacuum technology is applied to design and manufacture of the thermal vacuum chamber. This paper describe the vacuum technology which is applied to space business.

• Journal of the Korean Geotechnical Society
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• v.33 no.7
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• pp.5-16
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• 2017

Soil nailing is the most general method to reinforce the slope by taking pullout and shear resistance force of the nail for stabilizing the slope. Domestic soil nailing design method considers only pullout resistance and does not consider the shear resistance sufficiently. In case of nail, the effect of tensile stress is dominant, but it is desirable to design by considering shear stress as well as tensile stress in case of slope where circle failures occur. Recently, studies on the shear resistance effect of nails have been carried out in the geotechnical field. However, many researches on the shear reinforcement effect of soil nailing have not been conducted until now. Most of the studies are about increasing pullout resistance by improving material, shape and construction method of nail. Therefore, it is necessary to the study on shear resistance of soil nailing and development of new methods to increase the shear force. In this study, large shear test and limit equilibrium analysis have been performed for a new soil nailing method to increase the shear resistance by forming protrusions through pressurized grouting after installing a packer on the outside of deformed bar. The study results showed that shear resistance of protrusion type soil nailing increased compared to soil nailing and it is more effective when applied to the ground with large strength parameters.

• Journal of the Korean Institute of Intelligent Systems
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• v.25 no.2
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• pp.174-179
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• 2015

Failure Mode and Effects Analysis (FMEA) has been used by Dynamic Positioning (DP) system for risk and reliability analysis. However, there are limitations associated with its implementation in offshore project. 1) since the failure data measured from the SCADA system is missing or unreliable, assessments of Severity, Occurrence, Detection are based on expert's knowledge; 2) it is not easy for experts to precisely evaluate the three risk factors. The risk factors are often expressed in a linguistic way. 3) the relative importance among three risk factors are rarely even considered. To solve these problems and improve the effectiveness of the traditional FMEA, we suggest a Fuzzy-FMEA method for risk and failure mode analysis in Dynamic Positioning System of offshore. The information gathered from DP FMEA report and DP FMEA Proving Trials is expressed using fuzzy linguistic terms. The proposed method is applied to an offshore Dynamic Positioning system, and the results are compared with traditional FMEA.

• Journal of Sericultural and Entomological Science
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• v.49 no.2
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• pp.56-59
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• 2007

We bred new mulberry cultivar through local adaptability test, which was registered as a new cultivar for fruit production. Local adaptability test had been carried out at three places(Suwon, Konju and Cheongju) for three years since 2002. This is tetraploidy variety belonging to (Morus Lhou(Ser.) Koidz.) made by colchicine treatment on growing point of winter buds. Daeseongppong was high yielding in productivity by 48% compared to control cultivar "Chungilppong" for two years. Although Daesungppong was a little lower in sugar content of mulberry fruits, it contains more bioactive materials like C3G, rutin and amino acids than Chungilppong. It is adaptable to every where except the places where cold damage and sclerotial disease happen frequently.