• Title/Summary/Keyword: path widening

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Typology of Deteriorated Hiking Trails in Mountain National Parks of Korea (산악 국립공원 등산로의 훼손 유형과 요인)

  • Kim, Tae-Ho
    • Journal of the Korean association of regional geographers
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    • v.17 no.4
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    • pp.416-431
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    • 2011
  • Hiking trails in Mt Jiri, and Mt Halla, National Park have been examined in terms of their degrading factors. The trails are deteriorated by natural erosion processes as well as human trampling. Trail deterioration is classified into tread lowering, sidewall retreat, path widening and divergence based upon a place where erosional processes occur. Tread lowering and sidewall retreat is generally produced by natural erosion factors, whereas path widening and divergence is generated by human trampling. Rainwash is the most contributing process to tread lowering. By contrast, several processes such as rainwash, needle ice action, deflation, tree falling and animal activity play a major role in sidewall retreat according to physical conditions of a hiking trail. Path widening and divergence could be classified by a factor producing human trampling. There are lots of cases related to rainwash such as the tree root, gravel, and bedrock, exposed by a surface flow lowering a tread and the riser produced by tread scouring. A puddle of rainwater on a flat tread and a fallen tree of Abies koreana in a forest region are also major factors to cause path widening and divergence. A paved tread with stones encourages a hiker to walk out of a trail. Taking a shortcut also results in path widening and divergence without a factor giving a hiker inconvenience on a trail.

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Rates and Factors of Path Widening in Seongpanak Hiking Trail of Mount Halla, Jeju Island (한라산 성판악 등산로 노폭의 확대 속도와 요인)

  • Kim, Tae-Ho
    • Journal of the Korean Geographical Society
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    • v.43 no.3
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    • pp.296-311
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    • 2008
  • In order to examine the rates and factors of path widening in Mount Halla, the retreat of path sidewalls was monitored at 32 sites of Seongpanak Hiking Trail located between 875 m and 1,400 m in elevation. The mean rate of sidewall retreat for the period 2002-2008 is 50.6 mm, equivalent to 10.0 mm/yr. The retreat rate of frozen period is 19.3 mm/yr, while the rate of unfrozen period is 4.3 mm/yr. The latter is divided into the rainy and dry periods that exhibit the retreat rates of 5.9 mm/yr and 2.9 mm/yr, respectively. The retreat rate of sidewalls is also varied with seasons; winter shows the maximum rate of 42.2 mm/yr, while summer exhibits the minimum rate of 1.3 mm/yr. Spring and fall show the intermediate rates of 13.9 mm/yr and 6.4 mm/yr, respectively. Soil hardness and elevation are not closely related to the retreat rate of sidewalls, even though the retreat rate is larger at the north-faced sidewalls than the south-faced sidewalls during the frozen period. Pipkrake is likely to be the most important factor contributing to the path widening in that the retreat of winter months accounts for 76.7% of the total retreat. The hiking trail is placed under the climatic conditions which develop pipkrake in 85 days annually. In addition, it is usual to observe the path sidewall covered with pipkrake in the freezing month of December and the thawing months of March and April. On the other hand, deflation and rainsplash erosion are not important due to the weak wind speed and the forested trail. Rainwash is also insignificant in that the path has been almost paved to mitigate trampling effects. Although biological activity is not dominant, hikers cause a large retreat of sidewalls in the thawing months since they would walk on the sidewalls to avoid snow-melting pools on the path.

Development of a Dynamic Offtracking Model on Horizontal Curve Sections (Based on Articulated Vehicles) (도로 평면곡선부에서 동적궤도이탈모형 개발에 관한 연구 (굴절차량을 중심으로))

  • 최재성;김우현
    • Journal of Korean Society of Transportation
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    • v.20 no.3
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    • pp.115-128
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    • 2002
  • Dislike the tangent sections, the horizontal curve sections of roads should be designed, considering several factors : one of such factors is widening. In other words, since widening results from that when a vehicle runs on the horizontal curve sections, the rear wheels of the vehicle run not along with tracks of the front wheels but out of that, such offtracking should be exactly investigated and reflected in design of the curve sections. Especially in the case of industrial roads which semi-trailers and large trucks run frequently or arterial roads with small curve radiuses in mountainous regions. serious offtracking Phenomenons result in increasing the risk of accidents. decreasing the capacities and jeopardizing pedestrians' safety on the curve sections. For the offtracking, widening amounts of roads has been determined under the traditional presumption that vehicles run at a low speed and there is no superelevation. In fact, however, since the vehicles run at a high speed as well as at a low speed and the superelevation is installed on the horizontal curve sections in the structural aspect of roads, the existing standards for installing widening have a limitation to reflect exactly actual Phenomenons. In particular, for articulated wheel axles of a tractor and a trailer and long articulated vehicles, not only the offtracking degree is very high but also the interpretation shows different aspects from one of single axles. Comparing and reviewing the results of Korean and foreign studies related to the trailer offtracking model theory and the standards for installing widening, this study developed a realistic dynamic offtracking model which considers geometric structures of roads and speeds of vehicles, suggested how to measure widening with this model and examined applicability of the model. The findings of this study are as follows ; First. a dynamic offtracking model. which considers dynamic movements of a tractor and a trailer and the superelevation, was developed. Second, a new method to measure widening with the developed dynamic offtracking model was developed and a method to measure widening with swept path width was suggested as well. Finally, validity of the current standards for installing widening was examined by determining actual offtracking and widening amounts with the developed model and the applicability was investigated through the case studies. Compared with the existing offtracking models, the dynamic offtracking model developed in this study can reflect practically vehicle speed. dimension and geometric structural aspects of roads. In conclusion, the meaning of this study is that it reviews validity of the current standards for installing widening and provides a base to establish such standards by suggesting new methods to measure the widening with this dynamic offtracking model.

Types and Factors of Trail Degradtion in Daisetsuzan National Park, Hokkaido, Northern Japan (일본 홋카이도 다이세츠산 국립공원 등산로의 훼손 유형 및 요인)

  • KIM, Taeho
    • Journal of The Geomorphological Association of Korea
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    • v.19 no.2
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    • pp.187-195
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    • 2012
  • Daisetsuzan National Park in Hokkaido, Japan, has an extensive alpine region due to the topographic feature of lava plateau, and exhibits the surface geology largely composed of pyroclastic materials. In addition, the peak season of mountain climbing in the park coincides with a snow-melting period, resulting in severe soil erosion along hiking trails generated by human trampling, snow-melting water and pipkrake. Trail section has been particularly enlarged because the snow-melting water scours a trail surface and the pipkrake erodes sidewalls of a trapezoid-shaped trail. The scoured tread also forces hikers to walk out of a trail, and then frequently brings about path divergence as well as path widening. The soil particles, which are produced by erosional processes in a slope reach, flow downward, and cause the secondary trail degradation by covering a tread in a flat reach and nearby grassland.

Inclusive Innovation and Growth Based on a National Innovation System: Experience from China

  • Junfang, Zhang;Rong, Guo;Wei, Zhou
    • STI Policy Review
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    • v.3 no.2
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    • pp.66-78
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    • 2012
  • China is becoming a global hot topic because of its rapid economic growth. However, the country show signs of not meeting the expectation of retaining its long-term industrial competitiveness and economic growth, especially with a widening rich-poor gap and natural resource exhaustion. Realizing inclusive growth requires study of an inclusive innovation solution. In this paper, we analyze the feasibility and development path of China's inclusive innovation based on the framework of a National Innovation System, identify examples of inclusive innovation in China, and seek to provide policy suggestions for China's future sustainable development.

Hybrid-type stretchable interconnects with double-layered liquid metal-on-polyimide serpentine structure

  • Yim, Doo Ri;Park, Chan Woo
    • ETRI Journal
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    • v.44 no.1
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    • pp.147-154
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    • 2022
  • We demonstrate a new double-layer structure for stretchable interconnects, where the top surface of a serpentine polyimide support is coated with a thin eutectic gallium-indium liquid metal layer. Because the liquid metal layer is constantly fixed on the solid serpentine body in this liquid-on-solid structure, the overall stretching is accomplished by widening the solid frame itself, with little variation in the total length and cross-sectional area of the current path. Therefore, we can achieve both invariant resistance and infinite fatigue life by combining the stretchable configuration of the underlying body with the freely deformable nature of the top liquid conductor. Further, we fabricated various types of double-layer interconnects as narrow as 10 ㎛ using the roll-painting and lift-off patterning technique based on conventional photolithography and quantitatively validated their beneficial properties. The new interconnecting structure is expected to be widely used in applications requiring high-performance and high-density stretchable circuits owing to its superior reliability and capability to be monolithically integrated with thin-film devices.

Reevaluation of Lane Width Widenings on Horizontal Curve Sections (평면곡선부 확폭량 재설정에 관한 연구)

  • 최재성;백종대
    • Journal of Korean Society of Transportation
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    • v.18 no.4
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    • pp.51-62
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    • 2000
  • The objective of this study was to reevaluate current Korean design values for lane width widenings on horizontal currie sections and to develop a new method for derivation of design values based on low-speed offtracking. For this purpose, earlier research were reviewed and necessary equations were derived. Also, the method for derivation of widening values of Korea was compared with that for other countries. The result showed that present Korean method could not consider the variation of lane widths and design speeds of roads. In this Paper, to solve such problems, the new concept of widening was developed. That is the current concept of widening which concerns only the dimension of vehicles and radius of curves was replaced by a new concept that lane width widenings on horizontal curve sections is the difference between the width required on curries and tangents. The width required on a curve consists of the swept Path of a vehicle, lateral clearance, and additional allowance. The width of a tangent is calculated by multiplying lane width by the number of lanes The result of applying new concept shows that the values derived from new concept are higher than current design values for curries have same radius. This study was based only on low-speed offtracking. Therefor, it is recommended that further studies which consider the superelevation and high-speed effect on offtracking be made to derive more accurate widening values .

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Na-Ion Anode Based on Na(Li,Ti)O2 System: Effects of Mg Addition

  • Kim, Soo Hwa;Bae, Dong-Sik;Kim, Chang-Sam;Lee, June Gunn
    • Journal of the Korean Ceramic Society
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    • v.53 no.3
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    • pp.282-287
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    • 2016
  • This study involves enhancing the performance of the $Na(Li,Ti)O_2$ system as an Na-ion battery anode with the addition of Mg, which partially replaces Li ions. We perform both computational and experimental approaches to achieve a higher reversible capacity and a faster transport of Na ions for the devised system. Computational results indicate that the $Na(Li,Mg,Ti)O_2$ system can provide a lower-barrier path for Na-ion diffusion than can a system without the addition of Mg. Experimentally, we synthesize various $Na_z(Li_y,Mg_x,Ti)O_2$ systems and evaluate their electrochemical characteristics. In agreement with the theoretical study, Mg addition to such systems improves general cell performance. For example, the prepared $Na_{0.646}(Li_{0.207}Mg_{0.013}Ti_{0.78})O_2$ system displays an increase in reversible capacity of 8.5% and in rate performance of 13.5%, compared to those characteristics of a system without the addition of Mg. Computational results indicate that these improvements can be attributed to the slight widening of the Na-$O_6$ layer in the presence of Mg in the $(Li,Ti)O_6$ layer.

Analysis of Awareness of Radiation and Nuclear Power Plants after Fukushima Nuclear Accident (후쿠시마 원전 사고 후 방사선 및 원전에 대한 인식 분석)

  • Kim, Changsoo;Kim, Dong-Hyun;Kim, Jung-Hoon
    • The Journal of the Korea Contents Association
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    • v.13 no.9
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    • pp.281-287
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    • 2013
  • Based on surveys of Busan residents, this study aimed to analyze general perception: radiation knowledge, recognition of the standard of knowledge, radiation benefits, recognition of the risks of nuclear power, collection of information on the Fukushima nuclear accident, recognition of changes before and after the Fukushima nuclear accident, and the path of collecting information about nuclear power and radiation. This analysis was based on 414 people who reside in Busan metropolitan city. It has been found that the Busan metropolitan city residents acknowledged the necessity of radiation in principle, however, most have negative awareness relating to safety. It is assumed that this negative awareness is a result from past nuclear power plant accidents, rather than being based on their own knowledge of radiation. Therefore, it is considered that efforts to change people's awareness necessitate education of the public. This can be done via media, widening the range of people's knowledge, and furthermore, promoting changes within people's awareness and perspectives.