• Title/Summary/Keyword: toe load

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Estimating Wildfire Fuel Load of Coarse Woody Debris using National Forest Inventory Data in South Korea

  • Choi, Suwon;Lee, Jongyeol;Han, Seung Hyun;Kim, Seongjun;Son, Yowhan
    • Journal of Climate Change Research
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    • v.6 no.3
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    • pp.185-191
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    • 2015
  • This study presents an estimate of on-site surface fuel loadings composed of coarse woody debris (CWD) using $5^{th}$ National Forest Inventory (NFI) data in South Korea. We classified CWD data into forest type, region and decay class, and used conversion factors by decay class and tonne of oil equivalent developed in the country. In 2010, the total wildfire fuel load of CWD was estimated as 8.9 million TOE; those of coniferous, deciduous and mixed forests were 3.5 million TOE, 2.8 million TOE and 2.6 million TOE, respectively. Gangwon Province had the highest wildfire fuel load of CWD (2.3 million TOE), whereas Seoul exhibited the lowest wildfire fuel load of CWD (0.02 million TOE). Wildfire fuel loads of CWD were estimated as 2.9 million TOE, 1.9 million TOE, 2.4 million TOE and 1.7 million TOE for decay classes I, II, III and IV, respectively. The total wildfire fuel load of CWD corresponded to the calorific value of 8.2 million tons crude oil, 2.46% of that of living trees. Proportionate to the growing stock, total wildfire fuel load of CWD was in a broad distinction by region, while its TOE $ha^{-1}$ was not. This implies that there is no need to establish different guidelines by region for management of CWD. The results of this work provide a baseline study for scientific policy guidelines on preventing wildfires by proposing CWD as wildfire fuel load.

Effect of the Short Foot Exercise with 2nd~5th Toe Extension on the Abductor Hallucis Activity and Medial Longitudinal Arch under Various Loads (다양한 부하에서 2~5번째 발가락 폄을 동반한 짧은 발 운동이 엄지벌림근 근활성도와 안쪽세로활에 미치는 영향)

  • Seong-in Song;Chang-hwan Bae;Sang-hyun Kim
    • The Journal of Korean Academy of Orthopedic Manual Physical Therapy
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    • v.29 no.1
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    • pp.25-31
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    • 2023
  • Background: In this study, the abductor hallucis activity and medial longitudinal arch angle were compared by performing four exercises, namely the short foot exercise, the short foot exercise with 2nd~5th toe extension, the short foot exercise with 2nd~5th toe extension with a load of 1kt on the sole, and the short foot exercise with 2nd~5th toe extension with a load of 2kg on the sole. Methods: Four short foot exercises as described above were performed by 20 healthy adult males and females. The abductor hallucis activity and medial longitudinal arch angle were measured and analyzed by surface electromyography and the Kinovea software program. Results: The short foot exercise with 2nd~5th toe extension, short foot exercise with 2nd~5th toe extension with a load of 1kg on the sole, and the short foot exercise with 2nd~5th toe extension with a load of 2kg on the sole showed significantly higher abductor hallucis activity than the short foot exercise alone. Among these, the short foot exercise with the 2nd~5th toe extension was the most effective. All exercises showed a significantly decreased medial longitudinal arch angle post-exercise than pre-exercise, and the short foot exercise with the 2nd~5th toe extension showed a significantly decreased medial longitudinal arch angle compared to the other three exercises. Conclusion: It is believed that the short foot exercise with the 2nd~5th toe extension can be proposed as an effective exercise that can replace the short foot exercise alone.

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Design and Implementation of a Hybrid TCP/IP Offload Engine Prototype (Hybrid TCP/IP Offload Engine 프로토타입의 설계 및 구현)

  • Jang Han-Kook;Chung Sang-Hwa;Oh Soo-Cheol
    • Journal of KIISE:Computer Systems and Theory
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    • v.33 no.5
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    • pp.257-266
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    • 2006
  • Recently TCP/IP Offload Engine (TOE) technology, which processes TCP/IP on a network adapter instead of the host CPU, has become an important approach to reduce TCP/IP processing overhead in the host CPU. There have been two approaches to implementing TOE: software TOE, in which TCP/IP is processed by an embedded processor on a network adapter; and hardware TOE, in which all TCP/IP functions are implemented by hardware. This paper proposes a hybrid TOE that combines software and hardware functions in the TOE. In the hybrid TOE, functions that cannot have guaranteed performance on an embedded processor because of heavy load are implemented by hardware. Other functions that do not impose as much load are implemented by software on embedded processors. The hybrid TOE guarantees network performance near that of hardware TOE and it has the advantage of flexibility, because it is easy to add new functions or offload upper-level protocols of TCP/IP. In this paper, we developed a prototype board with an FPGA and an ARM processor to implement a hybrid TOE prototype. We implemented the hardware modules on the FPGA and the software modules on the ARM processor. We also developed a coprocessing mechanism between the hardware and software modules. Experimental results proved that the hybrid TOE prototype can greatly reduce the load on a host CPU and we analyzed the effects of the coprocessing mechanism. Finally, we analyzed important features that are required to implement a complete hybrid TOE and we predict its performance.

Design and Implementation of a Hardware-based Transmission/Reception Accelerator for a Hybrid TCP/IP Offload Engine (하이브리드 TCP/IP Offload Engine을 위한 하드웨어 기반 송수신 가속기의 설계 및 구현)

  • Jang, Han-Kook;Chung, Sang-Hwa;Yoo, Dae-Hyun
    • Journal of KIISE:Computer Systems and Theory
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    • v.34 no.9
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    • pp.459-466
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    • 2007
  • TCP/IP processing imposes a heavy load on the host CPU when it is processed by the host CPU on a very high-speed network. Recently the TCP/IP Offload Engine (TOE), which processes TCP/IP on a network adapter instead of the host CPU, has become an attractive solution to reduce the load in the host CPU. There have been two approaches to implement TOE. One is the software TOE in which TCP/IP is processed by an embedded processor and the other is the hardware TOE in which TCP/IP is processed by a dedicated ASIC. The software TOE has poor performance and the hardware TOE is neither flexible nor expandable enough to add new features. In this paper we designed and implemented a hybrid TOE architecture, in which TCP/IP is processed by cooperation of hardware and software, based on an FPGA that has two embedded processor cores. The hybrid TOE can have high performance by processing time-critical operations such as making and processing data packets in hardware. The software based on the embedded Linux performs operations that are not time-critical such as connection establishment, flow control and congestions, thus the hybrid TOE can have enough flexibility and expandability. To improve the performance of the hybrid TOE, we developed a hardware-based transmission/reception accelerator that processes important operations such as creating data packets. In the experiments the hybrid TOE shows the minimum latency of about $19{\mu}s$. The CPU utilization of the hybrid TOE is below 6 % and the maximum bandwidth of the hybrid TOE is about 675 Mbps.

TECHNIQUE OF SEPARATE MEASURING SIDE SLIP FOR TOE ANGLE AND CAMBER ANGLE

  • Nozaki, H.
    • International Journal of Automotive Technology
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    • v.7 no.6
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    • pp.681-686
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    • 2006
  • The current flat type side slip tester measures only the total side slip. Therefore, measurement techniques which can be used to determine the side slip for each alignment element were examined. Because the side slip related to the camber angle varies depending on the unit load per travel wheel while the side slip related to the toe angle does not on the unit per travel wheel, but depends only on the direction of the tire, the side slip for each alignment element can be determined separately.

The Studies on the Foot Stability and Kinesiology by Direction of Carry a Load during Gait (보행 시 부하의 위치에 따른 발의 안정성 및 운동학적 분석에 관한 연구)

  • Lee, Sang-Yeol;Bae, Sung-Soo
    • The Journal of Korean Physical Therapy
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    • v.21 no.2
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    • pp.97-101
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    • 2009
  • Purpose: This study examined how the direction of carrying a load affects the foot stability and kinesiology while walking. Methods: The heel rotation, Hallux stiffness, foot balance, metatarsal load, toe out angle, subtalar joint flexibility were measured in 40 adults (men and women) who carried a load back and forth, walking on a 2-meter-long board. The measurement was carried out three times and the mean of the measurements was used to compare the difference between the front, back and the condition without a load. Results: While walking, heel rotation and hallux stiffness occurred most when a front load was applied compared to a back load or no load condition (p<0.05). A metatarsal load also appeared to be the highest with the frond load, but there was no significant difference in the balance of the whole foot. Both the toe out angle and subtalar joint flexibility appeared to increase significantly (p<0.05). Conclusion: Applying the front load causes subtalar joint instability and increases the plantar foot pressure imbalance during walking.

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A Study on Stress Concentration Factor at Fillet Welded Joint (필렛용접이음부의 응력집중계수에 관한 연구)

  • S.W. Kang;W.I. Ha;J.S. Shin;J.S. Jae
    • Journal of the Society of Naval Architects of Korea
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    • v.33 no.3
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    • pp.1-7
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    • 1996
  • The stress concentration factor gives the significant effect the fatigue strength of welded joints. The model used herein is the type of the load carrying fillet welded cruciform joint with full or partial penetration. In order to obtain the stress concentration factor at the weld toe of fillet joint, the reasonable element size of the toe part is investigated and the stress analysis for the series models by FEM under tensile load is performed. On the basis of the calculation results, the estimated formulae for the stress concentration factor(Kt) at weld toe part of the fillet welded joint, which the effect of toe radius, flank angle and other parameters are taken into account, is derived.

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Preliminary Load Tests for the Design of Large Diameter Drilled Shaft by Bi-directional Loading Method at Toe (대구경 현장타설말뚝의 설계를 위한 선단재하방법에 의한 시험말뚝 재하시험)

  • Song, Myung-Jun;Park, Yung-Ho;Kim, Dong-Jun
    • Proceedings of the Korean Geotechical Society Conference
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    • 2005.03a
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    • pp.89-98
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    • 2005
  • Preliminary pile load tests for the design of large diameter drilled shaft were performed on two of reduced scale(D=1370mm) test piles. The maximum loads of 2350 tonf in each direction were applied using bi-directional hydraulic jacks(Osterberg Cell) at toe. Neither of the test piles yielded in terms of skin friction and end bearing. Comparisons of the test results with several methods that estimate pile capacity show that the method of Horvath and Kenney(1979) for skin friction and Zhang and Einstein(1998) for end bearing were most appropriate for the site. The test results were directly applied to pile design in case RQD of skin and toe was larger than that of the test pile. It is desirable, therefore, to consider not only unconfined compression strength but also rock mass properties(i.e. TCR, RQD) for skin friction and end bearing evaluation in the future.

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Evaluation of Influence on the Fatigue Strength of Residual Stresses at the Welded Toe of Welded Structure. (용접구조물 요접토우부의 잔류응력이 피로강도에 미치는 영향 평가)

  • 차용훈;김하식;김일수;성백섭
    • Transactions of the Korean Society of Machine Tool Engineers
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    • v.10 no.4
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    • pp.7-13
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    • 2001
  • This Study is to investigate the influence of weld residual stresses on the fatigue crack growth behaviors in pressure ves-sel reinforcement. In order to perform this study, the automatically welded specimens are prepared. The material is ASTM A516 grade 60 steel used in pressure vessel mainly. For pad-on-plate of skip welding continuous welding and PWHT specimen, fatigue crack initiation is generally initiat-ed at weld starting and end toe zone, and ruptured at weld starting toe zone, Fatigue life if pad-on-plate continuous speci-men is increased more than that of pad-on-plate skip fillet welding specimene about 85% under low load, about 20% under high load, and decreased than that of two-pad continuous welding specimen about 85%. In da/dN-$\Delta$ Κ curve under low load, pad-on-plate skip fillet welding specimen showed retardation on the initial crack, and the fatigue crack growth rate at the low region of $\Delta$Κ greater specimene E(3.8{\times}10^{-6}$mm/cycle). And the fatigue life of welding specimen was smaller than that of PWHT specimen.

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Influence of Bias Weight of Vibratory Pile Driver on Load Transfer Characteristics of Piles (진동타입기의 사하중이 말뚝의 하중전이 특성에 미치는 영향)

  • Lee, Seung-Hyun;Kim, Byung-Il
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.14 no.10
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    • pp.5268-5273
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    • 2013
  • Technique for analyzing pile installed by vibratory pile driver was developed and results of analysis obtained from variation of bias weight were studied. It can be seen from load transfer curve for dynamic skin friction that load transfer curve shift to downward as bias weight increases. Shape of load transfer curve for dynamic skin friction becomes closer to shape of coil as the bias weight decreases. Magnitudes of toe resistances were not affected by the bias weight. Shape of load transfer curve for dynamic toe resistance shows the similar tendency as the load transfer curve for skin friction exhibits. Vertical displacement increases as the bias weight increases and the shape of vertical displacement with time shows more distinct shape of wave.