• Title/Summary/Keyword: 타면적비

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Physicochemical Properties of Bamboo Charcoal Prepared from China-grown Bamboo (Phyllostachys pubescens) (중국산 죽순대(모죽)로부터 제조한 대나무 숯의 이화학적 특성)

  • 문성필;구창섭;박상범;권수덕
    • Journal of Korea Foresty Energy
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    • v.22 no.1
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    • pp.17-23
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    • 2003
  • Three different aged Chinese bamboo (Phyllostachys pubescense; 3, 5, and 7 years) was carbonized using three different types of kilns (special, improved and simple kiln) and their physicochemical charcoal properties were investigated. The fixed carbon of the bamboo charcoal prepared from the special kiln (800 - $1,000^{\circ}C$) tended to be decreased, while the specific surface area tended to be increased, according to the increase of bamboo ages. The bamboo charcoal prepared from the 5-year-aged showed the highest value in iodine value. In the improved kiln (600 - $700^{\circ}C$), the specific surface area and the iodine value increased with the growth period. In the simple kiln (400 - $500^{\circ}C$), the amount of volatile matter of the bamboo charcoal was approximately two times higher than that obtained from the special and improved kilns. Despite of the high amount of volatile matter in the simple kiln, the fixed carbon was more than 80%. The 5-year-aged bamboo charcoal showed the highest levels in specific surface area and iodine value. The physical properties of the bamboo charcoals prepared from the 3- and 5-year-aged Chinese bamboo were relatively worse those of Korean bamboo of the same ages. It was probably thought caused by less dense structure of the Chinese bamboo of 3- and 5-year-aged than the domestic in morphological aspects.

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A Study on Construction Manner of City Wall Parks in China Beijing (북경의 성곽역사공원 조성방식 연구)

  • Li, Ao-Fei;Kang, Tai-Ho
    • Journal of the Korean Institute of Traditional Landscape Architecture
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    • v.33 no.4
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    • pp.129-139
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    • 2015
  • Parks in order to find the inspiration and implication from their construction. The research is focused on a few cross-sectional city wall parks, which are Huangchenggen city wall park, Ming city wall park and Yuandadu city wall park. to come to the conclusion, it defines the generic concept of city wall park, clarifies the transitional process of the city of Beijing, organize the current situation and basis of the construction of the Beijing city wall parks. besides, by analyzing the Beijing city wall parks' specific construction manners including the basis of their planning, the support by government, planning functionality, landscape theme arrangement and gardening arrangement, the research puts forwards their construction characters and drawbacks. through comprehensive analysis on the aspects above, a series of inspirations are obtained for the construction of city wall parks. these include: specialized and legally valid regulation systems need to be setup before planning; government and citizens' proactive support is necessary for the protection of ancient city wall ruins and the construction of the city wall parks; when planning, existing situation should be utilized to the maximum extent, efficiency of space usage should be improved through smooth connection between different spacial locations.

Cause Analysis on Dry of stream flow for the Ui-Cheon (우이천의 건천화 원인분석)

  • Yi, Choong Sung;Choi, Seung An;Kim, Hung Soo;Shim, Myung Pil
    • Proceedings of the Korea Water Resources Association Conference
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    • 2004.05b
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    • pp.753-758
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    • 2004
  • 건천화란 하천이 건천이 되어가는 과정이라고 할 수 있다. 그러나 이의 정량적 접근이 어려운 이유는 건천이 되어가는 과정에 대한 현상을 지속적으로 관찰하기 어렵고, 순수한 자연현상이라기보다 인위적 요소가 간섭한 결과이기 때문이다. 본 연구는 건천이 되어가는 하천 중에서도 도시화에 의한 건천화의 영향이 큰 것으로 보이는 우이천 유역에 대해 건천화의 원인을 분석하여 몇 가지 결론과 대책을 제시하였다. 우이천은 유역면적 $27.67km^2$, 유로연장 11.75km의 비교적 좁은 면적 내에 인구 461,351명이 거주하고 주변 행정구역 총 인구가 604,282명인 지방2급하천이다. 유역 내 북부와 북서부의 산악지역을 통과하는 상류는 대부분 계류(溪流)로서 자연상태를 유지하고 있으나, 중${\cdot}$하류는 양안의 셋방, 복개, 직강화, 보 및 낙차공 등 인공구조물로 인해 하천형상이 크게 왜곡되어 있는 전형적인 도시하천유역이다. 본 연구는 우이천에 대한 건천화 원인분석을 위해 크게 4가지 방봅으로 접근하였는데 반분포형 유출모형인 TOPMODEL에 의한 장기유출분석, 수문${\cdot}$기상자료에 의한 분석, 인문${\cdot}$사회자료의 분석, 지하수위 분석 등이었다. 분석결과 우이천 유역과 같이 장기간에 걸쳐 도시화가 진행된 유역은 수문순환계의 왜곡이 돌이킬 수 없는 수준이므로, 적절한 건천화 방지대책의 방향은 건천화의 원인이 되는 인자를 제거함으로써 줄어든 유량을 회복하는 방안보다는 인위적이고 강제적인 방식으로 추가적인 하천수량을 확보하는 것이 타당하다 사료된다. 하천의 건천화는 하나의 주된 원인이 지배적일 수도 있지만 간접적인 영향이 많고, 하나의 원인이 다른 인자에 영향을 주어 연쇄적인 영향을 미칠 수도 있는 복잡한 현상이다. 따라서 다양한 각도에서 다양할 접근방식으로 방지대책을 수립하여야 할 것이다.적에 따른 임계지속기간과 유출량의 변화를 검토해 보았다.이를 각각의 경우의 해석해 결과와 비교${\cdot}$분석하였다. 후방추적 퍼프모형은 전방추적 퍼프모형에 비하여 사용된 퍼프수와 관계없이 작은 오차를 발생하였으며, 전체적으로 퍼프 모형이 입자모형보다는 훨씬 적은 수의 계산을 통해서도 작은 오차를 나타낼 수 있다는 것을 알 수 있었다. 그러나 Gaussian 분포를 갖는 퍼프모형은 전단흐름에서의 긴 유선형 농도분포를 모의할 수 없었고, 이에 관한 오차는 전단계수가 증가함에 따라 비선형적으로 증가하였다. 향후, 보다 다양한 흐름영역에서 장${\cdot}$단점 분석 및 오차해석을 수행한 후에 각각의 Lagrangian 모형의 장점만을 갖는 모형결합 방법을 제시할 수 있을 것으로 판단된다.mm/$m^{2}$로 감소한 소견을 보였다. 승모판 성형술은 전 승모판엽 탈출증이 있는 두 환아에서 동시에 시행하였다. 수술 후 1년 내 시행한 심초음파에서 모든 환아에서 단지 경등도 이하의 승모판 폐쇄 부전 소견을 보였다. 수술 후 조기 사망은 없었으며, 합병증으로는 유미흉이 한 명에서 있었다. 술 후 10개월째 허혈성 확장성 심근증이 호전되지 않아 Dor 술식을 시행한 후 사망한 예를 제외한 나머지 6명은 특이 증상 없이 정상 생활 중이다 결론: 좌관상동맥 페동맥이상 기시증은 드물기는 하나, 영유아기에 심근경색 및 허혈성 심근증 또는 선천성 승모판 폐쇄 부전등을 초래하는 심각한 선천성 심질환이다. 그러나 진단 즉시 직접 좌관상동맥-대동맥 이식술로 수술적 교정을 해줌으로써 좋은 성적을 기대할 수 있음을 보여주었다.특히 교사들이 중요하게 인식하는 해방적 행동에 대한 목표를 강조하여 적용할 필요가 있음을 시사하고 있다.교하여 유의한 차이가 관찰되지 않았다. 또한 HSP 환자군에서도 $IL1RN^{*}2$ allele 빈도와 carria

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Preliminary semi-quantitative evaluation of developed latent fingerprints on non-porous surface with natural powders using a densitometric image analysis (비 다공성 표면에서 천연분말로 현출된 잠재지문의 농도계 이미지분석을 이용한 예비적인 반 정량적 평가)

  • Kim, Eun-Mi;Heo, Bo-Reum;Ok, Yun-Seok;Kim, Jin-Kyung;Joung, In-Nam;Choi, Sung-Woon
    • Analytical Science and Technology
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    • v.29 no.6
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    • pp.283-292
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    • 2016
  • Conventional fingerprint powders used during crime scene investigations pose potential health hazards. Thus, multiple natural replacement powders, including squid ink powder, indigo and rice powder were used to develop (visualize) latent fingerprints on non-porous surfaces (e.g., glass, plastic and tile). Fingerprints developed using the natural powders were compared using the Automatic Fingerprint Identification System (AFIS) with those developed with traditional black powder. The peak areas of ridges were also compared using densitometric image analyses. Collectively, objective and quantitative evaluation methods were developed. The effectiveness of natural powders varied depending on the surface but, in general, squid ink powder performed well on most surfaces. Indigo powder performed well on tile surfaces, while rice powder performed well on glass surfaces. Plastic was the most difficult surface from which to develop fingerprints. Image analysis using Field Emission Scanning Electron Microscopy (SEM) demonstrated the importance of the size and shape of natural powder particles to properly adhere to the ridges. Although densitometric image analyses did not correlate the number of minutiae and ridge peak areas, an unbiased, objective evaluation method would be possible using image analyses with a reference image. Additional experimentation will yield safe and cost-effective natural powders with which adequate fingerprint development can be performed.

Influence of Preferred Chewing Habit on Electromyographic Activity of Masticatory Muscles and Bite Force (편측저작이 저작근의 근활성도와 교합력에 미치는 영향)

  • Yang, Ho-Yeon;Shin, Jun-Han;Choi, Jong-Hoon;Ahn, Hyoung-Joon
    • Journal of Oral Medicine and Pain
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    • v.30 no.1
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    • pp.45-55
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    • 2005
  • As people prefer to use right or left hand, some have preferred chewing side while others do not. Totally, 82 volunteers composed of students and staffs from Dental Hospital College of Dentistry Yonsei University participated in this study for the investigation of influence of preferred chewing habit, that has lasted for more than a year, on electromyographic(EMG) activity of masticatory muscles and bite force. Among the 82 volunteers, 46 had preferred chewing habit while the other 36 did not. Prior to the investigation, those with factors that could affect the study, such as, general disease, irregular dentition and malocclusion, were screened and excluded by questionnaire and clinical examination. The results were as follows: 1. There was no significant difference in EMG activities between chewing side and non-chewing side of preferred chewing subjects at rest as well as maximal voluntary contraction(MCV)(p>0.05). 2. Asymmetrical coefficient of temporal and masseter muscle EMG activities between preferred chewing subjects and non-preferred chewing subjects at rest was not significantly different(p>0.05). 3. Asymmetrical coefficient of masseter EMG activity was significantly higher(p<0.05) than that of non-preferred chewing subjects at MCV, whereas that of anterior temporal muscle showed no difference(p<0.05). 4. In preferred chewing subjects, there was no significant difference in average bite force and occlusal contact area between chewing side and non-chewing side(p>0.05). 5. There was no significant difference in Asymmetrical coefficients of average bite force and occlusal contact area between preferred chewing subjects and non-preferred chewing subjects (p>0.05). Consequently, preferred chewing habit can be considered as physiological asymmetry with normal function rather than to have influence on EMG muscle activity of masticatory muscles, average bite force and occlusal contact area. Objective standardization to differentiate preferred chewing subjects and non-preferred chewing subjects should be established in the further study.

Studies on the Flowering and Maturity in Sesame (Sesamum indicum L.) IV. Effects of Foliage Clipping on the Seed Maturity (참깨의 개화.등숙에 관한 연구 IV. 적엽처리가 참깨의 등숙에 미치는 영향)

  • Lee, Jung-Il;Kang, Chul-Whan;Son, Eung-Ryong
    • KOREAN JOURNAL OF CROP SCIENCE
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    • v.30 no.2
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    • pp.165-173
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    • 1985
  • The objectives of the study were to investigate the effects of foliage clipping on photosynthesis and grain filling for branch and non branch types under the polyethylene film mulch and non mulch conditions in mono cropping and second cropping after barley in sesame (Sesamum indicum L.), and to improve poor grain filling at later flowering time utilizing these data. One thousand grain weight was more decreased in branch type than in non branch type, in polyethylene film mulch condition than in non mulch condition, and in second cropping after barley than in mono cropping by clipping lower part foliage. Twentyfive percent clipping of lower part foliage showed a little increase than no clipping. Matured grain rate also showed same tendency between branch and non branch type and between mono cropping and second cropping after barley as well as 1,000 grain weight except for polyethylene film mulch. Matured grain rate of 25% foliage clipping at 30 days after flowering in non branch type presented a little increase but decreased in branch type. Clipping of higher part leaves were so serious decrease of matured grain rate that higher part leaves at late maturing time have a major role in photosynthesis. Matured grain rate of foliage clipping at 10 days after flowering was decreased in all treatments. Chlorophyll content of higher part leaves at 50% lower part foliage clipping presented 39% increase compared to same positioned leaves of non treatment, and 66% increase by 50% higher part foliage clipping in lower part leaves. Photosynthetic activity was 58% more increased in 50% lower part foliage clipping than no clipping, but seriously decreased in 50% higher part foliage clipping. Therfore, photosynthates of remained lower part leaves could not only support their own demands, but also any contribution to translocation of photosynthates from source to sink at late maturing time. Harvest index was 28% increased in 25% lower part foliage clipping and 13% decreased in 50% higher part foliage clipping compared to no clipping. Leaf area was 48% increased in 50% lower part foliage clipping compared to the same positioned leaves of no clipping, and only 5% increased in higher part foliage clipping. Productivity by foliage clipping compared to non treatment, was highly decreased in branch type than in non branch type, in second cropping after barley than in mono cropping. Little difference was detected between polyethylene film mulch and non mulch conditions. Twenty five percentage of lower part foliage clipping on mono cropping of non branch type appeared 5% and 8% yield increase in each of polyethylene film mulch and non mulch conditions compared to no clipping, and all decreased in other treatments. Mean loss of productivity by foliage clipping at 10 days after flowering was serious than clipping at 30 days after flowering. As the result, contribution to photosynthesis of source at 10 days after flowering are larger than that at 30 days after flowering in sesame. Fifty percent lower part foliage clipping at 10 days after flowering showed so the most serious yield decrease that lower part leaves at that time were considered as the main role leaves for photosynthesis.

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The Effects of Renewable Energy in Agricultural Sector (농업분야 신재생에너지 보급현황 및 파급효과 분석)

  • Park, Jiyun;Kim, Yeonjoong
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.20 no.1
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    • pp.224-235
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    • 2019
  • The increase in the amount of energy used in the agricultural sector due to the expansion of agricultural machinery and greenhouse horticulture has caused a range of problems, such as an increase in the cost of input, such as heating costs and greenhouse gas emission. To overcome these problems, this study examined the current status of energy use in greenhouse horticulture as well as the change patterns of non-taxable oil and agricultural electricity, and reviewed the current status of the supply of renewable energy and energy saving facilities for agriculture. This study investigated the area of advanced and renewable energy and energy saving facilities implemented, applied the energy saving ratio of advanced and renewable energy and energy saving facilities, and determined the effects of renewable energy in the agricultural sector, such as increase in production, decrease in heating cost, reduction in Government financial expenditure, reduction in greenhouse gas emission, and oil substitution effect.

A Design of Floating-Point Geometry Processor for Embedded 3D Graphics Acceleration (내장형 3D 그래픽 가속을 위한 부동소수점 Geometry 프로세서 설계)

  • Nam Ki hun;Ha Jin Seok;Kwak Jae Chang;Lee Kwang Youb
    • Journal of the Institute of Electronics Engineers of Korea SD
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    • v.43 no.2 s.344
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    • pp.24-33
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    • 2006
  • The effective geometry processing IP architecture for mobile SoC that has real time 3D graphics acceleration performance in mobile information system is proposed. Base on the proposed IP architecture, we design the floating point arithmetic unit needed in geometry process and the floating point geometry processor supporting the 3D graphic international standard OpenGL-ES. The geometry processor is implemented by 160k gate area in a Xilinx-Vertex FPGA and we measure the performance of geometry processor using the actual 3D graphic data at 80MHz frequency environment The experiment result shows 1.5M polygons/sec processing performance. The power consumption is measured to 83.6mW at Hynix 0.25um CMOS@50MHz.

Physicochemical Properties and Copper(II) Ion Adsorption Ability of Wood Charcoals (소나무 및 참나무 백탄의 물성과 구리(II) 이온 흡착 효과)

  • Lee, Oh-Kyu;Jo, Tae-Su
    • Journal of Korea Foresty Energy
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    • v.25 no.2
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    • pp.55-63
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    • 2006
  • Physicochemical properties and copper (II) adsorption ability of two oakwood and two pinewood charcoals, which were manufactured in traditional mode and commercialized in Korea, were examined pHs of these four wood charcoals were between 9.5 and 9.8. In the elemental contents of the wood charcoal, the contents of carbon atom (C) in the four samples were between 85-90%, while the content of hydrogen atom (H) in pinewood charcoal of the company 'S' was 1.62% and this value was three time higher than those of other samples. For iodine adsorption and specific surface area, the pinewood charcoal sample showed higher values than those of the oakwood charcoals. In the copper (II) ion adsorption in aqueous solution, the adsorption rate was increased by the increase of treated amounts of charcoal, treatment time, and pH.

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The Comparison of Experimental Results of Liquid Ejector Performance to Predictions by the Computer Aided Design Program (液休용 이젝터 性能에 관한 CAD와 實驗結果와의 比較)

  • 김경근;김명환;홍영표;고상철
    • Transactions of the Korean Society of Mechanical Engineers
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    • v.12 no.3
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    • pp.520-527
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    • 1988
  • Liquid ejectors are widely used as marine pumps, inducer stage for the boiler feed water pump, boiler recirculating pump, cooling water recirculating pump in boiling water type nuclear reactor and a deep well pump, because of their high working confidence and simplicity. Furthermore, it requires only a modest net positive suction head for cavitation-free operation and it can be installed in remote location from mechanical power source. It is not easy to presume the friction losses, because it is complicately affected by area ratio, flowrate ratio, nozzle spacing, throat length, shape of liquid ejector and so on. Therefore, the optimization of liquid ejector design is still dependent, to a large extent, on the experimental results and empirical procedures. On the design of the liquid ejector, the area ratio and the nondimensional throat length are the most important design factors among the mentioned above. In this experiment, the effects of the area ratio and the nondimensional throat length to ejector efficiency are carried out systematically by the combination of 4 kinds of motive nozzle and 2 kinds of throat length. In this paper, the present experimental results are compared with the calculated ones by the previous computer aided design program based on one dimensional flow equation. And also, an empirical equation for the working limit of liquid ejector is reported.