• Title/Summary/Keyword: Terrace

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Three-level Skip-lot sampling plan split by two stages (2단으로 분할된 3단계 스킵-로트 샘플링 검사계획)

  • 최병철;이은주
    • The Korean Journal of Applied Statistics
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    • v.8 no.2
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    • pp.55-64
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    • 1995
  • Three-level Skip-lot sampling plan split by two stages (Split2-SkSP0 is proposed by modifying multi-level skip-lot sampling plan proposed by Choi(1993), which has normal and terrace inspections on the first and the second stages, respectively. The plan is designed to work more higher level inspections when the quality of the submitted products are good, otherwise, return to the normal or the terrace inspection as fast as possible. Also, the formula of the operating characteristic function for the split skip-lot sampling plan is derived using the Markov chain approach. Also, operating characteristic properties of the proposed plans are studied and graphically compared with those of the multi-level skip-lot sampling plans.

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Surface Morphological Evolution of (0001) α-Al2O3 Substrate During Low Temperature Annealing (저온 열처리 과정에서 일어나는 (0001) α-Al2O3 기판 표면의 형상 변화)

  • Lee, Geun-Hyoung
    • Journal of the Korean Institute of Electrical and Electronic Material Engineers
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    • v.23 no.11
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    • pp.859-863
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    • 2010
  • Evolution of surface morphology of ${\alpha}-Al_2O_3$ substrate was investigated as a function of annealing temperature and time. Commercial (0001) ${\alpha}-Al_2O_3$ single crystal substrates were annealed in the range of $600-1000^{\circ}C$ in air. At $600^{\circ}C$, step-terrace structure started to be formed on the substrate. However, the surface roughness on the terrace was still considerable and a number of islands were observed on the step edges as well as the terraces. As the annealing temperature increased, the islands were absorbed into the step edges. Thus the terraces were smoother and the step edges were more straightened. Well-defined surface with a step height of 0.2 nm was formed above $900^{\circ}C$. On the other hand, when the substrate was annealed at a fixed temperature of $1000^{\circ}C$, the change of surface morphology was observed for the substrate annealed for 10 min. After the annealing for 30 min, the surface on which any islands could not survive was observed.

Hydrogen Adsorption on the Stepped Planes of Tungsten : I. (210) Plane (Stepped 텅스텐 결정면의 수소 흡착에 관한 연구 : I.(210)면)

  • 최대선;한종훈;백선목;박노길;김기석;황정남
    • Journal of the Korean Vacuum Society
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    • v.4 no.2
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    • pp.142-149
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    • 1995
  • 본 연구에서는 새로운 장전자 방출법(DOFEC법)으로 W(210)면의 수소 흡착에 의한 일함수의 변화, heat of desorption에 대하여 연구하였다. 텅스텐(210)면에 수소가 흡착될 때 흡착율에 따라 일함수가 증가하다가 다시 감소하는데 이것은 수소가 처음에는(210)면의 step((100)면)에 흡착되고 dose를 증가시킴에 따라 terrace((110)면)에 흡착되기 때문임을 알았다. 즉, terrace보다 step의 sticking coefficient가 더 크며 zero coverage에서의 그 비는 2.57이며 이는 타 연구 결과와 잘 일치한다. (210)면의 step과 terrace의 수소 흡착에 대한 일함수의 정량적인 변화량 그리고 수소 dose량에 대한 각각의 면에 대한 상대적인 흡착율을 얻었으며, 이 결과는 독립된(110)면 또는 (100)면의 결과와 잘 일치됨을 알았다. 또한 이 결과는 흡착 실험에 있어서 dose량을 흡착률로 환산하는데 사용될 수 있다. 텅스텐(210)면에는 4개의 흡착 site가 존재하며 이 site들 중 $\beta$2과 $\beta$4 state는 second order 탈착 과정을 따르며 $\beta$1과 $\beta$3 state는 first order 탈착과정을 따른다. 따라서 텅스텐(210)면에는 수소가 해리적 흡착을 함과 동시에 비해리적 흡착도 함을 알았으며(210)면의 각 흡착 site를 이에 대응되는 (100)면과 (110)면의 흡착 site와 비교 검토하였다.

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A Typology of Modern Housing in Malaysia

  • Ju, Seo-Ryeung;Omar, Saari Bin
    • International Journal of Human Ecology
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    • v.11 no.1
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    • pp.109-119
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    • 2010
  • Modernization of cities and housing in Malaysia is a reflection of the history of the establishment of colonial trading ports for worldwide maritime trade and exchange. In cosmopolitan cities, new housing typology appeared from the influence of various ethnic immigrants and with the fusion of traditional Malay housing characteristics. This study is to focus on classifying the housing typologies of Malaysia which were formed through the modernization process of cities. The typologies of modern housing in Malaysia can be classified into two categories. The first category is the 'transformation of traditional housing'. The representative typology of this group is the ubiquitous shophouse. The shophouse was originally brought in by the Chinese immigrants from the south coast of China and transformed into the Malaysian urbanscape. The other typology is a detached-house known as the bungalo, which was the housing style combining the Malay traditional timber house and European palazzo. The second category is the 'modern urban housing typology'. Modern urbanization after the independence from the British in 1957 required the maximum utilization of land. To accommodate new social and economic needs, the new typologies were developed in the form of medium-density terrace houses (row houses) and high-density apartment. In the suburban areas, the British terrace house was adopted and developed into unique Malaysian terrace house and semi-detached house based on the British system of land sub division. In premium area of the city, luxurious housing type in the form of high-end condominium is one of the popular housing for upper middle-class and high-class society.

Macrotidal Beach Classifications Considering Beach Profiles and Changes: The Case of Beaches in Taean Region (2017-2018) (지형형태와 변화를 반영한 대조차 해빈 분류: 태안지역 해빈을 사례로(2017-2018))

  • Kim, Chan Woong
    • Journal of The Geomorphological Association of Korea
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    • v.26 no.4
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    • pp.47-65
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    • 2019
  • A case study was conducted in Taean region to seek a more detailed macrotidal beach classification than existing beach classification models (Masselink and Short, 1993). Seepage and ridge & runnel were used for classification. On 20 beaches, 68 transects were surveyed 5 times using VRS-GPS. Cross-section area from the transect profiles, mean grain size from sediment analysis, significant wave height from Swan-wave modeling and beach embaymentization from aerial photograph analysis were used to identify the characteristics of the individual types. The transects were classified into 5 types in Taean region; Type 1: low tidal terrace, Type 2: low tidal terrace & ridge, Type 3: dissipative, Type 4: seasonal ridge, and Type 5: ridge & runnel. Generally, seepage was related to coarse sediment size and ridge & runnel was related to high significant wave height. Each type has different characteristics and there was a tendency between the types. The low tidal terrace type had coarse sediments, because this type is excluded from the littoral cell. In this study, the ridge and runnel type could be applied to the classification because the study area is limited only to the macrotidal environment in Taean region.

Grain Size Partitioning Using the Weibull Function and Origin of Fluvial Terrace Deposits (Weibull 함수를 이용한 입도 분리와 하안단구 퇴적층의 기원)

  • Park, Chung-Sun;Cho, Young-Dong;Lee, Gwang-Ryul
    • Journal of The Geomorphological Association of Korea
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    • v.26 no.2
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    • pp.15-27
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    • 2019
  • This study tries to reveal transport mechanism and origin of components from fluvial terrace deposits in Danyang and Geum River basins, through grain size partitioning using the Weibull function. Grain size parameters suggest that the samples analyzed in this study can be grouped into the coarse, fine and medium samples. The coarse samples are partitioned into three or four components. More than 65% of the coarse samples consist of components by suspension and saltation by fluvial process, while components by attachment to coarse grains or aggregates and/or by individual grains deposited under non-flow condition are also found in the coarse samples. The fine samples consist of four components and components found in loess deposits in Korea occupy >70%, suggestive of the same transport mechanisms (westerlies and winter monsoon) and common source areas with loess deposits in Korea. However, components by aeolian process from local sources as well as by fluvial process are also found in the fine samples. The medium samples are partitioned into components with similar sizes to the coarse and fine samples, respectively.

Fluvial Terrace and Incision Rate in the Middle Sobaek Mountain Range (소백산맥 중부 지역의 하안단구와 하각률)

  • Lee, Gwang-Ryul;Park, Chung-Sun
    • Journal of The Geomorphological Association of Korea
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    • v.28 no.2
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    • pp.15-30
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    • 2021
  • This study tried to reveal distribution of incision rate and the factors from fluvial terrace deposits on the western and eastern slopes in the Middle Sobaek Mountain Range, using OSL age dating and topographical analysis. An average incision rate of 0.220 m/ka was estimated in the western slope streams, while the streams on the eastern slope showed a lower average incision rate of 0.121 m/ka. These results seem to indicate that the study area experienced an asymmetric uplift. Patterns of incision rate in the study area were different from those in the Northern Sobaek Mountain Range, probably suggesting that the Sobaek Mountain Range experienced spatially different uplift patterns. Among the factors, which were considered to influence on distribution of incision rate in the study area (e.g., altitude of sampling point, distance from divide, distance from axis, channel width, and bedrock type), distance from axis showed the strongest relationship with incision rate. Therefore, uplift is thought to be the most significant factor in distribution of incision rate in the Middle Sobaek Mountain Range.

Characteristics of Geomorphological Surface and Analysis of Deposits in Fluvial Terraces at Upper Reach of Soyang River (소양강 상류 하안단구의 지형면 특성과 퇴적물 분석)

  • 이광률
    • Journal of the Korean Geographical Society
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    • v.39 no.1
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    • pp.27-44
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    • 2004
  • Upper reach of Soyang River at the northernmost area around Taebaek Mountains in South korea is profitable area to understand paleo-environment during the Quaternary such as tectonic process and climate change in the Korean Peninsula. This study explained paleo-environment affect to channel development by geomorphic distribution and characteristics of terrace surfaces, and analysis of deposits at 58 fluvial terraces in upper reach of Soyang River. Fluvial terraces were classified from T1 to T6. Most terraces are distributed on the point bar in meandering channel and one side along river valley. Terraces tend to decrease in number and superficial dissection rate to be higher and channel slope to be steeper if it takes long time from T1 to 6. The paleo-channel of Soyang River is supposed to be stronger meandering in period of T2 than T3. The weathering rind of gravel is generally thicker in older terrace, however, differs by contents of water and air in deposits. Based on the data of stratigraphy, grain size analysis, pollen analysis and rubification index in deposit, formation age of T5 terrace in Soyang River are estimated in MIS(Marine Oxygen Isotope Stage) 10, and T2 terrace are estimated in MIS 6.

Application of Potassium Feldspar pIR-IRSL Method to Dating Quaternary Marine and Fluvial Terrace Sediments in Korea: A Case Study on a Fluvial Terrace and Gusan Fault in Uljin, Korea (한반도 해안-하안단구 퇴적층에 대한 K 장석 pIR-IRSL연대측정법 적용가능성 고찰: 울진 하안단구와 구산단층 연대측정)

  • Hong, Seongchan;Choi, Jeong-Heon
    • The Journal of the Petrological Society of Korea
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    • v.25 no.3
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    • pp.241-252
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    • 2016
  • In this paper, in order to test the possibility of applying K feldspar $pIR-IRSL_{290}$ signal(read out at $290^{\circ}C$) to date old terrace sediments(up to ~ 200 ka, MIS 7) in Korea, we investigated luminescence properties of $pIR-IRSL_{290}$ signals in K feldspar extracts from 27 marine and fluvial terrace sediment samples, and these were compared with those of quartz OSL and conventional K feldspar $IRSL_{50}$ (readout at $50^{\circ}C$) signals. The averaged $2D_0$ value of K feldspar $pIR-IRSL_{290}$ growth curves was ~ 700 Gy, which is consistent with that of $IRSL_{50}$ signal, and this is 3 times higher than that for quartz OSL (~ 250 Gy) on average. Where possible, K feldspar $pIR-IRSL_{290}$ ages were compared with quartz OSL and conventional $IRSL_{50}$ ages. Our preliminary K feldspar $pIR-IRSL_{290}$ ages were older than quartz OSL ages by about 200%, while fading rate-corrected conventional $IRSL_{50}$ ages are in good agreement with those based on quartz OSL. This seems to indicate the possibility of K-feldspar $pIR-IRSL_{290}$ age overestimation due to the presence of unbleachable $pIR-IRSL_{290}$ signals, even with a prolonged exposure to sunlight. Both quartz OSL and K-feldspar $pIR-IRSL_{290}$ signals for the samples from Noeum fluvial terrace and Gusan fault site were all in dose saturation level, thus unable to estimate the formation ages of the sediments. However, $2D_0$ values derived from the dose response growth curves strongly indicate that the Noeum fluvial terrace sediments have formed before 109-140 ka, while the fluvial sediments from Gusan fault were desposited before 100-105 ka. Further, this seems to suggest that the previous quartz OSL ages of ~40-50 ka for Gusan fault sediments should be the underestimated ones due to dose saturation problem.