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The Design of DRAM Memory Modules in the Fabrication by the MCM-L Technique (DRAM 메모리 모듈 제작에서 MCM-L 구조에 의한 설계)

  • Jee, Yong;Park, Tae-Byung
    • Journal of the Korean Institute of Telematics and Electronics A
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    • v.32A no.5
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    • pp.737-748
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    • 1995
  • In this paper, we studyed the variables in the design of multichip memory modules with 4M$\times$1bit DRAM chips to construct high capacity and high speed memory modules. The configuration of the module was 8 bit, 16 bit, and 32 bit DRAM modules with employing 0.6 W, 70 nsec 4M$\times$1 bit DRAM chips. We optimized routing area and wiring density by performing the routing experiment with the variables of the chip allocation, module I/O terminal, the number of wiring, and the number of mounting side of the chips. The multichip module was designed to be able to accept MCM-L techiques and low cost PCB materials. The module routing experiment showed that it was an efficient way to align chip I/O terminals and module I/O terminals in parallel when mounting bare chips, and in perpendicular when mounting packaged chips, to set module I/O terminals in two sides, to use double sided substrates, and to allocate chips in a row. The efficient number of wiring layer was 4 layers when designing single sided bare chip mounting modules and 6 layers when constructing double sided bare chip mounting modules whereas the number of wiring layer was 3 layers when using single sided packaged chip mounting substrates and 5 layers when constructing double sided packaged chip mounting substrates. The most efficient configuration was to mount bare chips on doubled substrates and also to increase the number of mounting chips. The fabrication of memory multichip module showed that the modules with bare chips can be reduced to a half in volume and one third in weight comparing to the module with packaged chips. The signal propagation delay time on module substrate was reduced to 0.5-1 nsec.

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Volatility of Herbicides Sprayed in Zoysia japonica Turf and Bare Soil (잔디밭과 나지에 산포된 주요 잔디밭용 제초제의 휘산)

  • 김석정;박진희;죽내안지;김길웅;신동현;허영조
    • Asian Journal of Turfgrass Science
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    • v.10 no.3
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    • pp.263-270
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    • 1996
  • This experiment was conducted to investigate the loss of various herbicides by means of vola-tility from the turfgrass field and the hare ground with the different soil moisture contents and temperatures. Different herbicides were applied at the rates of 375 g a.i. /l0a of pendimethalin,250 g a.i. /l0a of napropamide, and 96.4 g a.i. /l0a of dicamba with 200 \ulcorner/10a of spray volume in the turfgrass(Zoysia japonica cut off 5cm) grown in pots(265.8 $cm^2$) and bared soil. The pots were placed in the growth chamber with 10,000 lux of light intensity(12h per day) at 25 and 35˚C for 7days. Amberlite XAD polymeric resin(20/50 mesh) was used as sampling media for herbicide airborne residues. Air flow was maintained at 10 \ulcorner /min by vacuum pump regulated with a factory calibrated flow meter. Herbicide airborne residues were extracted from the XAD resin with 300 ml of 1:1 acetone and hexane. The extracts were concentrated by rotary evaporation at 35˚C and dissolved in 1 ml MeCN for HPLC analysis. The airborne losses of the herbicide applied in the turfgrass and bare soil increased as the temperature and soil moisture contents were increased, regardless of the kinds of herbicide. Higher airborne residues was observed in the turfgrass pots than the bare soil pots. Pendimethalin and dicamba with higher vapor pressure gave rise to the increased loss of airborne herbicides, showing that 6.26 and 6.4% of average airborne loss in pendimethalin and dicamba, respectively, compared to 0.56% in napropamide. The amount of airborne losses in turfgrass was highest at one day after application and then a declined trend was observed as the time was prolonged. Key words. Herbicides, Turfgrass field, Bare ground, Volatility.

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Photosynthetic Characteristics and Growth Performances of Containerized Seedling and Bare Root Seedling of Quercus acutissima Growing at Different Fertilizing Schemes (시비 처리에 따른 상수리나무(Quercus acutissima) 용기묘와 노지묘의 광합성 및 생장특성)

  • Kwon, Ki Won;Cho, Min Seok;Kim, Gil Nam;Lee, Soo Won;Jang, Kyung Hwan
    • Journal of Korean Society of Forest Science
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    • v.98 no.3
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    • pp.331-338
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    • 2009
  • This present study was conducted to investigate photosynthetic characteristics, chlorophyll fluorescence, chlorophyll contents, and growth performances of containerized seedling and bare root seedling of Quercus acutissima growing under different fertilizing schemes. Both of containerized seedling and bare root seedling of Quercus acutissima showed good photosynthetic capacity and apparent quantum yield in the seedlings applied with one gram refining fertilizer (each of N, P, and K is 19%) diluted in one liter water. And chlorophyll contents also showed higher in the seedlings applied with the above fertilization scheme. The seedlings also showed good relative growth performances of root collar diameter, seedling height, total biomass, and leaf area in the some treatment scheme. In most of the treatments, containerized seedlings showed better photosynthetic capacity, apparent quantum yield, chlorophyll contents, and growth performances than bare root seedlings.

The heat transfer characteristics of a desorber for 150 RT absorption heat pump (150 RT급 흡수식 열펌프용 고온재생기의 열전달 특성)

  • 박찬우;정종수
    • Korean Journal of Air-Conditioning and Refrigeration Engineering
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    • v.11 no.3
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    • pp.369-376
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    • 1999
  • Experiments were carried out to study the heat transfer characteristics of a disrober for 150 RT LiBr-water absorption heat pump. An experimental apparatus was divided into four sections, a combustion chamber area, two bare-tube areas, and finally a finned-tube area to quantify the heat transfer rate of each section by measuring the generation rate of vapor. Dividing plates was installed at the upper inside part of deserter to prohibit the moving of vapor generated at heating tubes of a section to another section near. In the first bare-tube area, the generation rate of vapor was the largest among the four sections. The finned-tube area only contributed to give sensible heat increase of solution to the saturation temperature. The heat transfer area of the finned-tube area was 52.2%, which absorbed only 9.2% of the total heat from the combustion gas. On the contrary, the heat transfer area of the first bare-tube area was 16.6%, but it absorbed 52.4% of the total absorbed heat. The temperature of the solution at upper part at the finned-tube area was lower than that of the lower part, because weak solution came in upper part of the finned-tube area. But, this tendency was changed at the first and second bare-tube area due to the vigorous heat transfer and fluid flow enhanced by vapor generation through heating tubes. The overall heat transfer coefficient and heat flux were the largest at the first bare-tube area among the other sections.

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Influence of Walking With High-Heeled Shoes on the Knee Joint of Obese Women (하이힐 보행이 비만여성의 슬관절에 미치는 영향)

  • Chang, Yun-Hee;Lee, Wan-Hee
    • Physical Therapy Korea
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    • v.14 no.3
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    • pp.23-31
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    • 2007
  • The purpose of this study was to determine the influence of high-heeled shoes on walking of obese women as it was already proven an extrinsic factor of knee osteoarthritis in women with normal weight. In this study the aimed therefore in particular was to utilize high-heeled shoes in proving it's causal influence on knee osteoarthritis by measuring the angle and torque of the knee joint. Fifteen obese women (BMI>25 $kg/m^2$) were measured in their twenties. Each angle and torque of their knee joints during walking on 6.5 cm high-heeled shoes and with a bare feet, were compared with each other and analyzed with a 3D motion analysis system. There was no significant difference in walking speed, cadence and stride length between the two conditions. However, there was a significant increase in a double limb support time and the stance phase when walking on high-heeled shoes as when walking with bare feet. The peak knee flexion angle and peak knee varus torque was higher when walking on high-heeled shoes than with bare feet. On the contrary, the peak knee flexion angle in the swing phase was not statistically different. The prolongation of peak knee varus torque was also proven. There was a significant increase in peak knee varus torque in the initial and last stance phases during walking on high-heeled shoes as compared to walking on bare feet. Through the above results, it was proven that when obese women walked on high-heeled shoes, rather than with bare feet, peak knee flexor and varus torque increased along with the changes of the in knee joint angle. Therefore, the influence of high-heeled shoes might be a significant intrinsic factor in knee osteoarthritis of obese women.

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Effects of Fertilization Treatments on Growth of Container and Bare Root Seedlings of Pinus densiflora (시비처리가 소나무 용기묘와 노지묘의 생육에 미치는 영향)

  • Cho, Min-Seok;Kim, Gil-Nam;Lee, Sang-Tae;Moon, Hyun-Shik
    • Journal of agriculture & life science
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    • v.46 no.2
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    • pp.63-73
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    • 2012
  • This study was conducted to investigate effects of fertilization treatments (non-fertilizing, deep-fertilizing 20g, 50g, 100g, and surface-fertilizing 20g) on survival rate, growth performances, and seedling quality index (SQI) of container seedling and bare root seedling of Pinus densiflora in the field. There were no significantly differences in survival rate among fertilization treatments in the field. Besides, there was no toxic effect on seedling by over 100g fertilization in deep-fertilizing treatment. The root collar diameter and height of P. densiflora in both seedling types were the highest at 100g fertilization in deep-fertilizing treatments, and the biomass products and SQI were the same as above growth of root collar diameter and height. In most of the treatments, container seedlings showed better growth performances than bare root seedlings. In optimal fertilization, effect of fertilization was higher in container seedling than bare root seedling.

Complementary Calculation of Current Carrying Capacity for Bare Overhead Conductors (가공선용 나전선의 허용전류 산정 보완)

  • Son, Hong-Gwan;Lee, Eun-Ung
    • The Transactions of the Korean Institute of Electrical Engineers A
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    • v.51 no.5
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    • pp.225-231
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    • 2002
  • Many standards have Published for calculating of current carrying capacity for bare overhead conductors. Although these standards use the same basic heat balance concept, they use different approaches to calculate current carrying capacity, This paper looks at the four approaches used to calculate individual heat balance terms, at the overall impact of these terms on the current carrying capacity And this paper is proposed to the selection of proper standard and AC resistance within a country conditions for calculating the current carrying capacity of bare overhead conductors. So current carrying capacities are Proposed to some of conductors.

A research on the features of suspended sediments origination in natural world (자연계에 있어 부유사 발생원의 특성에 관한 연구)

  • 이성기
    • Journal of Environmental Science International
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    • v.11 no.6
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    • pp.483-488
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    • 2002
  • Suspended sediment outflows mainly by natural situation and artificial action and affects in down-stream. This research studied suspended sediments origination in forests size and mountain stream for natural situation, density for artificial action, and measured the size and possible quantity of suspended sediments origination and studied obstruction method of the generation by artificial action. As the result, I found that the size of generation is about 2~3% of forest size and the forest size which is affecting bare area of valley is about 1∼2ha. In addition, possible outflow segments quantity by artificial facilities is assumed to be maximum 200ton/ha and abstract of mountain incline for mountain development needs minimize bare area valley by make right angle with minimum size.

Quench characteristics of bare and of-laminated YBCO-coated conductor (YBCO 고온초전도체의 \ulcorner치특성 연구)

  • Kim Ho-Min;Park Kwon-Bae;Lee Bang-Wook;Oh Il-sung;LEE Hai-gun;Iwasa Yukikazu
    • Progress in Superconductivity and Cryogenics
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    • v.6 no.3
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    • pp.1-5
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    • 2004
  • This paper presents a study on the stability of bare and cu-laminated YBCO-coated conductor. we investigate the characteristics of quench/recovery behavior of YBCO test samples. bare and copper-laminated, by subjecting each test sample. immersed in a bath of liquid nitrogen boiling at 77.3 K. to a transport current pulse superimposed to a baseline DC current of 90-95% the critical current. The current pulse has an amplitude up to ∼4.5 times the critical current and a duration of 300 ms. This paper presents both experimental and simulation results.

Hydrogen Absorption and Desorption Behaviors of Hydrogen Storage Alloy Powder Compacts in Hydride Cylinder (수소용기내에서 수소저장합금 분말 성형체의 수소 흡수 및 방출 거동)

  • Kim, Chan-Jung;Lee, Jae-Myoung;Kim, Dai-Ryong
    • Transactions of the Korean hydrogen and new energy society
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    • v.6 no.1
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    • pp.43-52
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    • 1995
  • Hydrogen storage alloy powder compacts were prepared by using automatic press, with PTFE as a binder. Hydrogen absorption and desorption characteristics and thermal conducting property of the compacts were studied using test hydrogen cylinder, comparing with bare alloy powder. The compacts showed better rate capability and activation characteristics than bare powder. Effective thermal conductivity and diffusivity of the compact bed were $1.0{\times}10^{-2}W/cmK$ and $2.0{\times}10^{-2}cm^2/S$, respectively, which were similar to that of bare powder bed. A good rate capability of the compacts was interpreted in terms of hydrogen permeation rather than thermal conductivity in the beds.

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