• 디지털융복합연구
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• 제10권11호
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• pp.343-349
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• 2012

사용 조절 모델은 보호된 컨텐츠의 사용에 대한 포괄적인 기술을 허용하는 새로운 접근 조절 모델의 시초이다. 이 범례에서 객체로의 접근에 관련된 결정은 요청 시간에만 제한되어있지 않다. 그것은 보호된 객체의 사용과 결합되며 사용과 병렬식으로 진행되는 지속적 처리가 된다. 사용 조절의 실현은 오랫동안 보안 문서의 전파에 있어서 조절 능력을 잃게 되는 문제를 해결하려한 연구 과제이다. 클라우드 컴퓨팅의 발현으로 문서들이 클라우드에 저장이 되고 문서를 보거나 편집할 수 있는 프로세서들이 클라우드안에 상주하며 문서들은 브라우저와 같은 신 클라이언트에 의해 접근이 가능해진다. 우리는 그러한 시나리오가 이해 당사자의 정책에 기반을 둔 문서 사용 보안에 대한 사용 조절의 실행에 있어 이상적인 기회를 제공하는 사실에 주목한다. 본 논문에서는 클라우드 기반의 어플리케이션에서 더 나은 멀티미디어 컨텐츠를 실행하기 위한 멀티미디어 컨텐츠 관리(MCM)를 제안한다. 그리고 클라우드 컴퓨터의 발현과 사용을 통해 보안된 객체의 사용에 있어 매끄러운 조절을 제공하기 위한 강력한 구성을 설계한다. 우리는 이러한 실현을 위해 설계 원칙을 기술하고 제안 구조를 논한다.

• 자원환경지질
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• 제16권2호
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• pp.65-78
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• 1983

This report deals with the sedimentological study of the littoral sand of beaches in the Busan area. The purpose of this report is to know the grain size, mineralogical composition, heavy mineral and clay mineral of the beach sands, and gravity measurements of the Nagdong River Deltas. 1) As a whole, the littoral sand of the beaches are composed of uniformly medium grained, moderately sorted and nearly symmetrical. The barrier sand of the Nagdong Estuary is composed of fine grained, well sorted and nearly symmetrical. 2) The littoral sand of the beaches is transported by saltation and rolling. The barrier sand of the Nagdong Estuary is transported by suspension and saltation. 3) In the littoral sand of the beaches, the ratio of feldspar to quartz is 1 :2.31 and in the barrier sand of the Nagdong Estuary 1:1.40. 4) The content of heavy mineral of samples ranges from 0.54 to 3.87 %. The principal heavy minerals are hornblende, pyroxene, epidote, garnet, leucoxene, zircon, apatite, magnetite, hematite and ilmenite with minor accessories of rutile and olivine. 5) The x-ray diffraction analysis of the clay mineral informs the existence of quartz, feldspar, kaolinite and montmorillonite. The montmorillonite is considered to have been derived from the alteration of acidic volcanic rocks. 6) To determine the depositional structure of the Nagdong Estuary, Gravity measurements were made. Free air anomaly ranges from 14.5 mgal to 33.5 mgal and Bouguer anomaly ranges from 14.3 to 23.5 mgal and both are closely related to the topography. According to the interpreted layer structure, the upper layer composing sand, silt and clay, the intermediate layer composing sand with gravel, the lower layer composing weathered and soft rock, and bed rock composing hornfels or andesite. 7) The depositional environments of the study, the littoral area is dominated by the marine environment and the Nagdong Estuary by the mixed environment.

• International Journal of Computer Science & Network Security
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• 제21권11호
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• pp.199-206
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• 2021

Rhetorical relations between two text fragments are essential information and support natural language processing applications such as Question - Answering (QA) system and automatic text summarization to produce an effective outcome. Question - Answering (QA) system facilitates users to retrieve a meaningful response. There is a demand for rhetorical relation based datasets to develop such a system to interpret and respond to user requests. There are a limited number of datasets for developing an Arabic QA system. Thus, there is a lack of an effective QA system in the Arabic language. Recent research works reveal that unsupervised learning can support the QA system to reply to users queries. In this study, researchers intend to develop a rhetorical relation based dataset for implementing unsupervised learning applications. A web crawler is developed to crawl Arabic content from the web. A discourse-annotated corpus is generated using the rhetorical structural theory. A Naïve Bayes based QA system is developed to evaluate the performance of datasets. The outcome shows that the performance of the QA system is improved with proposed dataset and able to answer user queries with an appropriate response. In addition, the results on fine-grained and coarse-grained relations reveal that the dataset is highly reliable.

• 한국농공학회지
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• 제28권4호
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• pp.66-76
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• 1986

This study was attempted to investigate the effects of delayed compaction on the unconfined compressive strengh and dry density of Soil-cement mixtures. Soil-cement construction is a time-consuming procedure. Time-delay is known as a detrimental factor to lower the quality of soil-cement layer. A laboratory test was performed using coarse and fine weathered granite soils. The soils were mixed with 7% cement at optimum moisture content and excess moisture content in part. Socondary additives such as lime, gypsum-plaster, flyash and sugar were tried to counteract the detri-mental effect of delayed compaction. The specimens were compacted by Harvard Miniature Compaction Apparatus at 0,1,2,4,6 hors after mixing. Two kinds of compactive efforts(9 kgf and 18 kgf tamper) were applied. The results were summarized as follows: 1.With the increase of time delay, the decrease rate of dry density of the specimen compacted by 9 kgf tamper was steeper than that of the specimen compacted by 18kgf tamper. In the same manner, soil-B had steeper decreasing rate of dry density than soil-A. 2.Based on the results of delayed compaction tests, the dry density and unconfined compressive sterngth were rapidly decreased in the early 2 hours delay, while those were slowly decreased during the time delay of 2 to 6 hours. 3.The dry density and unconfined compressive strength were increased by addition of 3% excess water to the optimum moisture content during the time delay of 2 to 6 hours. 4.Without time delay in compaction, the dry densities of soil-A were increased by adding secondary additives such as lime, gypsum-plaster, flyash and sugar, on the other hand, those of soil-B were decreased except for the case of sugar. 5.The use of secondary additives like lime, gypsum-plaster, flyash and sugar could reduce the decrease of unconfined compressive strength due to delayed compaction. Among them, lime was the most effective. 6.From the above mentioned results, several recommendations could be suggested in order to compensate for losses of unconfined compressive strenght and densit v due to delayed compaction. They are a) to use coarse-grained granite soil rather than fined-grained one, b) to add about 3% excess compaction moisture content, c) to increase compactive effort to a certain degree, and d) to use secondary additives like line gypsum-plaster, flyash, and sugar in proper quantity depending on the soil types.

• Geomechanics and Engineering
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• 제11권2호
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• pp.197-209
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• 2016

Clayey rock has large clay mineral content. When in contact with water, this expands considerably and may present a significant hazard to the stability of the rock in geotechnical engineering applications. This is particularly important in the present work, which focused on mitigating some unwelcomed properties of clayey rock. Changes in its physical properties were simulated by subjecting the rock to a low voltage direct current (DC) using copper, steel and aluminum electrodes. The modified mechanism of the coupled electrical and chemical fields acting on the clayey rock was analyzed. It was concluded that the essence of clayey rock electrochemical modification is the electrokinetic effect of the DC field, together with the coupled hydraulic and electrical potential gradients in fine-grained clayey rock, including ion migration, electrophoresis and electro-osmosis. The aluminum cathodes were corroded and generated gibbsite at the anode; the steel and copper cathodes showed no obvious change. The electrical resistivity and uniaxial compressive strength (UCS) of the modified specimens from the anode, intermediate and cathode zones tended to decrease. Samples taken from these zones showed a positive correlation between electric resistivity and UCS.

• 지질공학
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• 제19권3호
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• pp.409-415
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• 2009

일반적으로 흙의 투수계수를 예측하기 위하여 Kozeny-Carman 공식이 널리 적용되어왔다. 그러나 Kozeny-Carman 공식은 모래질 흙의 투수계수 예측에는 좋은 결과를 나타내나 점성토와 같은 세립토에는 적합하지 않다. 따라서 본 논문에서는 Kozeny-Carman 공식을 고려하여 점성토의 투수계수를 예측할 수 있는 이론식을 제시하였다. 이론식을 위해 해안가의 점성토와 댐의 심벽재로 사용하는 다짐 점성토의 토질특성에 대해 조사 분석하였다. 연구 결과, 토질특성과 투수계수 사이의 주요 관계 요소로, 해안가 점성토는 점토함유율, 다짐 점성토는 #200통과율과 관계가 있는 것으로 나타났다.

• Ocean and Polar Research
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• 제25권2호
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• pp.133-145
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• 2003

Deep-sea surface sediments were collected using a multiple corer at 20 stations of Clarion-Clipperton fracture zone in the northeast equatorial Pacific to understand latitudinal and longitudinal variations of geotechnical properties. There was a distinct latitudinal variation of geotechnical properties in the study area. The northern sediments showed finer grain size, lower water content and porosity, higher bulk density and specific grain density, lower liquid limits and plastic limits than their southern counterparts. The northern sediments are classified into inorganic clays of low plasticity (fat clays) on plasticity charts and normal to active clay on activity chart, whereas, the southern sediments are classified into fine-grained, highly-plastic, inorganic and biogenic silt or organic clays on plasticity chart and normal to very active clay on activity chart. When shear strength are considered, the northern sediments were found to be in unconsolidated states, while the southern ones to be normal to over-consolidated states. These latitudinal variations in sediment characteristics are likely caused by differences in productivity of surface water that controls sediment compositions, sedimentation rates, and grain solubility.

• Geomechanics and Engineering
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• 제12권1호
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• pp.111-125
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• 2017

Swelling and shrinkage characteristics of expansive fine grained soil cause volumetric changes followed by distress and damage to the structures. Soil stabilization can be explained as the alteration of the soil properties by chemical, mechanical or any other means in order to enhance the engineering properties of the soil. Utilization of industrial wastes in soil stabilization is cost effective and environment friendly. This paper presents an experimental study on stabilization of expansive soil using industrial wastes, viz. fly ash and dolochar. The paper includes the evaluation of engineering properties like unconfined compressive strength and California bearing ratio (CBR) of expansive soil collected from Balasore district of Odisha stabilized with fly ash and dolochar in different proportions and to predict the influence of these additives on engineering properties and strength characteristics of expansive soil. Both fly ash and dolochar were found to increase the CBR and decrease many index properties such as liquid limit, plastic limit, plasticity index, swelling index and UCS, thus enhancing the strength parameters of expansive soil.

• 한국지반공학회:학술대회논문집
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• 한국지반공학회 2004년도 춘계학술발표회
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• pp.533-537
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• 2004

The erodibility of soil is an important factor to scour, especially in fine-grained soils. In this study, the erosion characteristics of kaolinite are quantified through the scour rate tests using the Erosion Function Apparatus called EFA. The basic soil property tests are also performed. The kaolinite samples are prepared by mixing with distilled water and formed to the designed maximum consolidation pressure of 60, 110, 160, 240, 360kPa, respectively. The results of the scour rate tests are presented in a format of a plot showing the relationship between erosion rates and shear stresses. Erosion properties of kaolinite showed a striking contrast according to the maximum consolidation pressure, and a correlation was established between the erosion properties of kaolinite and the soil properties; water content, undrained shear strength, dry density.

• 한국가구학회지
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• 제11권2호
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• pp.25-35
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• 2000

This study was carried out to investigate the wood properties for development the proper uses of lesser-known tree species. The tested species are Tamiang(Hydnocarpus woodii) Bangelem (Strombosia zeylanica) and Kamasulan(Anisophyllea ferruginea) grown in Indonesia. fundamental wood properties such as anatomical, physical and chemical properties and characteristics related to wood processing were examined. The results are summarized as follows : These species are diffuse porous, interlocked grained and coarse textured wood. Exceptionally, texture of Tamiang is fine. The heartwoods of these species are not distinguished clearly to the sapwoods. These species have high specific gravity, high shrinkage, and excellent strength properties. However, Tamiang has moderate specific gravity. Sawing characteristics are poor for these species except Tamiang. Sawing characteristics is moderate for Tamiang. Drying characteristics are moderate for Tamiang and Bangelem, and Poor for Kamasulan. The surfacing characteristics by planer are moderate f3r all these species. Bending property and durability are poor. Ash content is low in Bangelem.