• Title/Summary/Keyword: high-capacity

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The Study for System Specification of Rolling Stock of Honam High Speed Railroad (호남고속철도 차량 시스템 사양에 관한 연구)

  • 주인환;박광복
    • Proceedings of the KSR Conference
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    • 2002.10a
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    • pp.104-112
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    • 2002
  • The Honam conventional railroad was already exceseed the limit capacity of transportal ion at some sect ion. Therefore Honam railroad axis needs new high speed railroad line for increasing of transportal ion capacity now. This report was studied about the system technical specification of rolling stock based on new technology or high speed train or advenced countries, KHST and KTX for Honam high speed railroad.

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The Effects of Transcranial Direct Current Stimulation Combined High Intensity Interval Training on Aerobic Exercise Capacity of the Soccer Player (tDCS를 결합한 고강도 인터벌 훈련이 축구선수의 유산소 운동능력에 미치는 영향)

  • Yang, Dae-Jung;Uhm, Yo-Han
    • Journal of The Korean Society of Integrative Medicine
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    • v.9 no.4
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    • pp.105-117
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    • 2021
  • Purpose : This study examined the effect of transcranial direct current stimulation (tDCS) combined high intensity interval training (HIIT) on the aerobic exercise capacity of college soccer players. Methods : The subjects of this study were 30 college soccer players. They were divided into a high intensity interval training group combining transcranial direct current stimulation (Group I) and a high intensity interval training group (Group II). Each group had 15 subjects randomly assigned. After receiving general soccer training, each group additionally received high intensity interval training combined with transcranial direct current stimulation and high intensity interval training for 30 minutes 5 times a week for 8 weeks. Their VO2max and 20 meter shuttle run test, Yo-Yo intermittent recovery test were analyzed before the intervention. After 8 weeks of intervention, the above items were re-measured and an intergroup analysis was performed. Results : As a result of comparative analysis of VO2max intake between groups, 20 meter shuttle run test and Yo-Yo intermittent recovery test, a statistically significant difference was found. The high intensity interval training group (Group I) combined with transcranial direct current stimulation showed a significant difference in aerobic exercise capacity compared to the high intensity interval training group (Group II). Conclusion : These results showed that high intensity interval training group combined with transcranial direct current stimulation was more effective for aerobic exercise. Based on this study, this study proposes an effective program for patients as well as elite athletes. In the future, it is necessary to develop an effective transcranial direct current stimulation program and to study how to apply it for various patients.

A Study on the Electrode Characteristics of a New High Capacity Non-Stoichiometry Zr-Based Laves Phase Alloys for Anode Materials of Ni/MH Secondary Battery

  • Lee Sang-Min;Yu Ji-Sang;Lee Ho;Lee Jai-Young
    • Journal of the Korean Electrochemical Society
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    • v.3 no.2
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    • pp.72-75
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    • 2000
  • For the purpose of developing the non-stoichiometric Zr-based Laves phase alloy with higher capacity and better performance for electrochemical application, extensive work has been carried out in KAIST. After careful alloy design of $ZrMn_2-based$ hydrogen storage alloys through varing their stoichiometry while susbstituting or adding some alloying elements, the $Zr-Ti-(Lh-V-Ni)_{2.2},\;Zr-Ti-(Mn-V-Cr-Ni)_{1.8\pm0.1}$ with high capacity and better performance was developed. Consequently the $Zr-Ti-(Mn-V-Ni)_{2.2}$ alloy has a high discharge capacity of 394mAh/g and shows a high rate capability equaling to that of commercialized $AB_5$ type alloys. On the other hand, in order to develop the hydrogen storage alloy with higher discharge capacity, the hypo-stoichiometric $Zr(Mn-V-Ni)_{2-\alpha}$ alloys substituted by Ti are under developing. As the result of competitive roles of Ti and $stocihiometry({\alpha})$, the discharge capacity of $Zr-Ti-(Mn-V-Cr-Ni)_{l.8\pm0.1}$ alloys is about 400mAh/g(410 mAh/g, which shows the highest level of performance in the Zr-based alloy developed. Our sequential endeavor is improving the shortcoming of Zr-based Laves phase alloy for commercialization, i.e., poor activation property and low rate capability, etc. It is therefore believed that the commercialization of Zr-based Laves phase hydrogen storage alloy for Ni-MH rechargeable battery is in near future.

Potential Water Retention Capacity as a Factor in Silage Effluent Control: Experiments with High Moisture By-product Feedstuffs

  • Razak, Okine Abdul;Masaaki, Hanada;Yimamu, Aibibula;Meiji, Okamoto
    • Asian-Australasian Journal of Animal Sciences
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    • v.25 no.4
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    • pp.471-478
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    • 2012
  • The role of moisture absorptive capacity of pre-silage material and its relationship with silage effluent in high moisture by-product feedstuffs (HMBF) is assessed. The term water retention capacity which is sometimes used in explaining the rate of effluent control in ensilage may be inadequate, since it accounts exclusively for the capacity of an absorbent incorporated into a pre-silage material prior to ensiling, without consideration to how much the pre-silage material can release. A new terminology, 'potential water retention capacity' (PWRC), which attempts to address this shortcoming, is proposed. Data were pooled from a series of experiments conducted separately over a period of five years using laboratory silos with four categories of agro by-products (n = 27) with differing moisture contents (highest 96.9%, lowest 78.1% in fresh matter, respectively), and their silages (n = 81). These were from a vegetable source (Daikon, Raphanus sativus), a root tuber source (potato pulp), a fruit source (apple pomace) and a cereal source (brewer's grain), respectively. The pre-silage materials were adjusted with dry in-silo absorbents consisting wheat straw, wheat or rice bran, beet pulp and bean stalks. The pooled mean for the moisture contents of all pre-silage materials was 78.3% (${\pm}10.3$). Silage effluent decreased (p<0.01), with increase in PWRC of pre-silage material. The theoretical moisture content and PWRC of pre-silage material necessary to stem effluent flow completely in HMBF silage was 69.1% and 82.9 g/100 g in fresh matter, respectively. The high correlation (r = 0.76) between PWRC of ensiled material and silage effluent indicated that the latter is an important factor in silage-effluent relationship.

직접해법에 의한 공기 윤활 틸팅 패드 저어널 베어링의 윤활 해석에 관한 연구

  • 김인식;황명
    • Proceedings of the Korean Society of Precision Engineering Conference
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    • 1993.04b
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    • pp.121-126
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    • 1993
  • Tiling pad journal bearing that has high stability is analyzed about air-lubricated bearing that is usually used to need high precision by using the Direct analysis. The pressure that supports the shaft is occured by the differences between the shaft and pads radii of curvatures. So the characteristics of load capacity for their variable values is important. In this paper the load capacity is compared with some the eccentricity ratio values of0.1, 0.2, 0.5, 0.8. The large load capacity comes from large eccentricity ratio, highbearing number and high preload. But if the preload become high too much, then the shaft makes contact with pads.

EFFECT OF DESIGN PARAMITERS ON SEASONAL PERFORMANCE OF AN A/C SYSTEM (공기조화기의 설계인자가 계절성능에 미치는 영향)

  • Park, Y.C.
    • 한국전산유체공학회:학술대회논문집
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    • 2010.05a
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    • pp.239-241
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    • 2010
  • Performance evaluation for an air conditioning system is conducted at a specified test conditions. One is low temperature and the other is high temperature condition. Most of the manufactures tried to improve the performance at higher outdoor temperature. One of the reasons is that the customer wants to get ore capacity at high temperature climate. To cope with these kinds of demand, manufactures are tried to achieve higher capacity at high temperature with minimum power consumption even with same size of the system. Consequently, previous studies on performance of the air conditioning system are focused on capacity and performance improvement at high outdoor temperature.

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Design of Transverse Steel Amounts of High Strength Reinforced Tied Columns by Axial Capacity Design Method (내력설계법에 의한 고강도 철근콘크리트 띠철근 기둥의 횡보강근량 산정)

  • 한범석;신성우
    • Proceedings of the Korea Concrete Institute Conference
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    • 2003.05a
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    • pp.151-156
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    • 2003
  • On the basis of the philosophy that "the compressive axial load capacity after spalling of shell concrete should be maintained as that before spalling" by applying the confinement model of high strength concrete proposed in the previous proceeding paper and equivalent lateral confining pressure considering configurations of transverse reinforcement, the amounts of transverse reinforcement from the compressive capacity design method about high strength reinforced concrete tied columns can be calculated through the formula proposed in this paper. The proposed design equation of transverse steel amounts for high strength reinforced concrete tied columns was quite agreeable with the test results of HSC tied columns conducted by other researchers as well as author.as author.

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Convective Heat Transfer of a Paraffin Slurry in a Drag Reducing Carrier Fluid (유동저항 감소유체를 운반유체로 한 파라핀 슬러리의 대류 열전달에 관한 연구)

  • 정동주;최은수
    • Korean Journal of Air-Conditioning and Refrigeration Engineering
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    • v.13 no.12
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    • pp.1275-1281
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    • 2001
  • Aqueous polymer solutions are known to have small pressure reduction. Paraffin slurries are known to have high thermal capacity. Paraffin particles are mixed into an aqueous polymer solution to make a new heat transfer fluid having high thermal capacity but low pressure reduction. The heat transfer characteristics of the new slurry was tested in a circular tube having a constant heat transfer boundary condition. The new slurry was found to have high Nusselt numbers as well as high thermal capacity and low pressure reduction in the laminar flow. The trends of the Nusselt numbers along the heating test section were studied for various heating conditions.

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Comparing Empirical Methods of Highway Capacity Estimation (실험적 용량산정 방법 비교 연구)

  • Moon, Jaepil;Cho, Won Bum
    • International Journal of Highway Engineering
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    • v.16 no.1
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    • pp.57-62
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    • 2014
  • PURPOSES : Capacity is a main factor of determining the number of lane in highway design or the level of service in road on operation. Previous studies showed that breakdown may occur before capacity is reached, and then it was concluded that capacity is a stochastic value rather than a deterministic one. In general, estimating capacity is based on average over maximum traffic volume observed for capacity state. This method includes the empirical distribution method(EDM) and would underestimate capacity. This study estimated existing empirical methods of estimating stochastic highway capacity. Among the studied methods are the product limit method(PLM) and the selected method(SM). METHODS : Speed and volume data were collected at three freeway bottleneck sites in Cheonan-Nonsan and West Sea Freeway. The data were grouped into a free-flow state or capacity state with speeds observed in the bottlenecks and the upstream. The data were applied to the empirical methods. RESULTS : The results show that the PLM and SM estimated capacity higher than EDM. The reason is that while the EDM is based on capacity observations only, the PLM and SM are based on free-flow high volumes and capacity observations. CONCLUSIONS : The PLM and SM using both free-flow and capacity observations would be improved to enhance the reliability of the capacity estimation.

A Study on the Reliability of an Air Foil Journal Bearing for High Speed Turbomachinery (고속 터보기계용 공기 포일 저널 베어링의 신뢰성에 관한 연구)

  • Lee, Yong-Bok;Kim, Tae-Ho;Kim, Chang-Ho;Lee, Nam-Soo
    • 유체기계공업학회:학술대회논문집
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    • 2002.12a
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    • pp.199-206
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    • 2002
  • This paper describes a reliability characteristics of an air foil journal bearing for high speed turbomachinery at room temperature. To verify the reliability of air foil journal bearing, lift-off characteristics, load carrying capacity, and 10,000 cycle start-stop test were performed with motor driven test rig. Lift-off test shows the relationship between the rotating speed of the shaft and the frictional torque with bearing surface. About load carrying capacity, the tested air foil journal bearing produced a load capacity of 500N at an operating speed of 15,000rpm, which is compared with results of numerical analysis and empirical coefficients. Finally, The trends in change of start torque, stop torque, and bearing temperature were shown during 10,000 cycle start-stop test of an air foil journal bearing. from the results of this work, an air foil bearing will be done well, as a supported bearing for high speed turbo-compressor.

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