• Title/Summary/Keyword: Limiting factors

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A Study on the Utilization of Alternative Materials for the Visually Impaired Using Reading Aids Devices (독서보조기기를 이용한 시각장애인 대체자료 이용 활성화 방안 연구)

  • Hwang, Shin-Ae;Lee, Seungmin
    • Journal of the Korean BIBLIA Society for library and Information Science
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    • v.31 no.3
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    • pp.191-211
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    • 2020
  • The main purpose of this research is to identify limitations and problems in access to information using reading aids devices for the visually impaired and to suggest ways to activate the use of alternative materials using reading aids devices. A survey was conducted on adults with visual impairment in order to identify the factors of limitation in using reading aids devices. The analysis resulted in six aspects of limiting factors in activating the use of reading aids devices. The approaches for activating the use of reading aids devices were proposed by dividing them into policy and operational aspects, focusing on the limiting factors derived. Policy aspects suggested developing low-cost reading aids devices, increasing awareness of the devices, and complying with Web standard guidelines for improving the applicability of the devices, while operational aspects suggested reinforcing hearing-use functions, expanding information services related to reading aids devices, and enhancing portability of the devices.

Effect of the Compound Factors on the Survival of Tapes Philippinarum (복합요인이 바지락( Tapes Philippinarum)의 생존에 미치는 영향)

  • 최기철;권오길
    • The Korean Journal of Zoology
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    • v.9 no.2
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    • pp.1-6
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    • 1966
  • Effects of compound factors (temperature , salinity and turbidity 0 on Tapes philippinarum are as follows : 1. At 3 and 6 hours , critical temperature of 0.9-1.05 mm size is 38$^{\circ}C$ and 7.5-8.5mm, 23-25 mm exist between 35$^{\circ}C$ and 41$^{\circ}C$. 2. The main limiting factor of three combined factors is temperature. The effect on the survival of Tapes philippinarum is as follows : Temperature > salinity > turbidity. 3. In the worst condition, treatment time is also an important factor. Mortality is higher at 6 hour treatment than 3 hour. 4. We observed 39$^{\circ}C$ of water temperature at Tapes bed of Inchon in July 1965. Compared with experimental results, we are able to suppose that the mortality will be occurred at high degrees in the natural state. 5. As the size of the individual is increased , the survival rate is increased as well.

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Particle Agglomerate Effect on Intermediate/Final Microstructure (입자 응집이 중기/말기 미구조에 미치는 영향)

  • 손영돈;전병세
    • Journal of the Korean Ceramic Society
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    • v.29 no.11
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    • pp.843-850
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    • 1992
  • The purpose of this study was to describe the heterogeneity effects on Intermediate/Final microstructure in isothermal liquid phase sintering. Several kinds of pore shapes were made by the different in the heterogeneity stress level during Intermediate/Final stage. Specimen with 48% green density especially showed that the local regions of a sintered compact were subject to more rapid shrinkage than the surroundings. This densification limiting factors generally inhibited sintering and made the large isolated crack-like pore in heterogeneous microstructures.

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Surgical Treatment of the Funnel Chest by Sternoturnover method (우두흉(漏斗胸)의 외과적(外科的) 치료(治療) (Sterno-turnover 방법(方法)에 의(依)한))

  • Choi, Soon Ho
    • Journal of Chest Surgery
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    • v.9 no.2
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    • pp.143-147
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    • 1976
  • A case of congenital funnel chest which was observed in 6 year old male was reported. The patient represented clinical status of depression of lower sternum, recurrent upper respiratory tract infection, and slight exertional dyspnea. The treatment was carried out by "turnover" method, and it was easy to do viable on sternum, costal cartilage, and intercostal muscles. And it is fit to reimplantation by free autograft when repair was indicated. The plane of the manubrium, an acute hump on the sternum, and asymmetry constitute limiting factors in the cosmetic results.

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Developing Elements of E-Commerce in Ubiquitous Environment (유비쿼터스 환경하의 전자상거래 증진요소)

  • Kim, Kwang-Hyun
    • Proceedings of the Korea Contents Association Conference
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    • 2013.05a
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    • pp.115-116
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    • 2013
  • There are other limitations on B2C e-commerce that have the potential to cap its growth rate and ultimate size. Table 1.4 describes some of these limiting factors. Some limitations may be minimized in the next decade. For instance, the price of an entry-level computer such as a netbook has fallen to $200-$300, although this still represents a substantial amount of money to many.

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Unusual ALD Behaviors in Functional Oxide Films for Semiconductor Memories

  • Hwang, Cheol Seong
    • Proceedings of the Korean Vacuum Society Conference
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    • 2013.08a
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    • pp.77.1-77.1
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    • 2013
  • Atomic layer deposition (ALD) is known for its self-limiting reaction, which offers atomic-level controllability of the growth of thin films for a wide range of applications. The self-limiting mechanism leads to very useful properties, such as excellent uniformity over a large area and superior conformality on complex structures. These unique features of ALD provide promising opportunities for future electronics. Although the ALD of Al2O3 film (using trimethyl-aluminum and water as a metal precursor and oxygen source, respectively) can be regarded as a representative example of an ideal ALD based on the completely self-limiting reaction, there are many cases deviating from the ideal ALD reaction in recently developed ALD processes. The nonconventional aspects of the ALD reactions may strongly influence the various properties of the functional materials grown by ALD, and the lack of comprehension of these aspects has made ALD difficult to control. In this respect, several dominant factors that complicate ALD reactions, including the types of metal precursors, non-metal precursors (oxygen sources or reducing agents), and substrates, will be discussed in this presentation. Several functional materials for future electronics, such as higher-k dielectrics (TiO2, SrTiO3) for DRAM application, and resistive switching materials (NiO) for RRAM application, will be addressed in this talk. Unwanted supply of oxygen atoms from the substrate or other component oxide to the incoming precursors during the precursor pulse step, and outward diffusion of substrate atoms to the growing film surface even during the steady-state growth influenced the growth, crystal structure, and properties of the various films.

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Using Trophic State Index (TSI) Values to Draw Inferences Regarding Phytoplankton Limiting Factors and Seston Composition from Routine Water Quality Monitoring Data (영양상태지수 (trophic state index)를 이용한 수체 내 식물플랑크톤 제한요인 및 seston조성의 유추)

  • Havens, Karl E
    • Korean Journal of Ecology and Environment
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    • v.33 no.3 s.91
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    • pp.187-196
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    • 2000
  • This paper describes a simple method that uses differences among Carlson's (1977) trophic state index (TSI) values based on total phosphorus (TP), chlorophyll a (CHL) and Secchi depth (SD) to draw inferences regarding the factors that are limiting to phytoplankton growth and the composition of lake seston. Examples are provided regarding seasonal and spatial patterns in a large subtropical lake (Lake Okeechobee, Florida, USA) and inter- and intra-lake variations from a multilake data set developed from published studies. Once an investigator has collected routine water quality data and established TSI values based on TP, CHL, and SD, a number of inferences can be made. Additional information can be provided where it also is possible to calculate a TSI based on total nitrogen (TN). Where TSI (CHL)<>TSI (SD), light attenuating particles are large (large filaments or colonies of algae), and the phytoplankton may be limited by zooplankton grazing. Other limiting conditions are inferred by different relationships between the TSI values. Results of this study indicate that the analysis is quite robust, and that it generally gives good agreement with conclusions based on more direct methods (e.g., nutrientaddition bioassays, zooplankton size data, zooplankton removal experiments). The TSI approach, when validated periodically with these more costly and time-intensive methods, provides an effective, low cost method for tracking long-term changes in pelagic structure and function with potential value in monitoring lake ecology and responses to management.

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Characterization of Water and Sediment Environment in Water Shield (Brasenia schreberi) Habitats (순채 생육지에서 수체와 저토의 환경요인 분석)

  • Kim, Yoon-Dong
    • The Korean Journal of Ecology
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    • v.19 no.3
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    • pp.209-216
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    • 1996
  • In order to identify the habitat characteristics of water shield (Brasenia schreberi), water quality and sediment characters were investigated. Water shield had peculial habitats such as old reservoir, developed basin-like reservior, a water depth within 1.5 m, constant water level, and thick sediment layer at the bottom. The species had very dense populations under the favorable growing conditions and occasionally grew together with Utricularia japonica. When water shield decreased, Nelumbo nucifera, Nuphar japonicum and Zizania latifolia increased. Natural populations of water shield need protection because it is endangered by the human activities and their harvest. The optimal conditions for the growth of water shield was near neutral pH. low conductivity and low turbidity. Therefore the input of pollutants should be controlled for its growth. The inorganic ion contents such as K, Mg, and Na were higher in the water shield growing area. Especially iron content of the sediments in the reservoirs with water shield was nearly five times as high as that in the reservoirs without water shield. thus iron might be one of the major limiting factors for the growth. It was considered that molybdenum can be another major factor because water shield is a nitrogen fixing plant.

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Minimum Thickness of Long Span RC Deck Slabs for Composite 2-girder Bridges Designed by KL-510 Load Model (KL-510 하중모형을 적용한 강합성 2거더교 RC 장지간 바닥판의 최소두께)

  • Park, Woo-Jin;Hwang, Hoon-Hee
    • Journal of the Korean Society of Safety
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    • v.29 no.3
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    • pp.72-78
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    • 2014
  • The minimum thickness of long-span deck slab is proposed by checking the limit state according to the Korean highway bridge design code(limit state design). Both minimizing thickness and ensuring safety of deck slab are important design factors to increase a competitive price of the long span deck slabs. The required thicknesses for satisfying flexural capacity, preventing punching shear failure and limiting deflection were calculated by considering KL-510 load model which has increased total load compared to DB 24 from 432 kN to 510 kN. The results of the required thickness for various limit states were compared to propose the minimum thickness as a function of span length of deck slabs. The proposed minimum thickness is influenced by satisfying flexural capacity and limiting deflection. It turns out to be similar compared to the results of the previous study by ultimate strength design method even if the live load model was increased in total weights.

EMERGING DISEASE PROBLEMS IN KOREAN RICE AND THEIR ORIGINS

  • Brown William M.
    • Korean journal of applied entomology
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    • v.15 no.1 s.26
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    • pp.39-46
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    • 1976
  • As the technology of rice production in Korea has rapidly developed and progressed over the last few years, many problems in rice production have been solved. But with the introduction of new genetic material, the increased use of pesticides, higher fertilizer rates and closer plantings, new problems are beginning to emerge. The brown plant hopper outbreak in 1975 resulted to a great extent from some of the changes in management practices. Some rice diseases and nutritional problems that have existed in Korea but have not been considered of serious consequence, are now becoming increasingly severe and possibly as limiting as the hopper outbreak in 1975. Other diseases and nutritional problems are completely new and their cause and significance have not yet been adequately defined. In this discussion there is no Intention to state, nor is there evidence to support a statement, that any of these problems are going to be limiting factors in the future production of rice on the Korean peninsula. Rather this is an attempt to bring together some of the current field problems in Korean rice so that they can be discussed and where necessary receive suitable consideration for research and control.

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