• Geomechanics and Engineering
• /
• 제17권3호
• /
• pp.271-278
• /
• 2019

In recent years, the crack accidents of earth and rockfill dams occur frequently. It is urgent to study the tensile strength and tensile failure mechanism of the gravelly soil in the core for the anti-crack design of the actual high earth core rockfill dam. Based on the self-developed uniaxial tensile test device, a series of uniaxial tensile test was carried out on gravelly soil with different gravel content. The compaction test shows a good linear relationship between the optimum water content and gravel content, and the relation curve of optimum water content versus maximum dry density can be fitting by two times polynomial. For the gravelly soil under its optimum water content and maximum dry density, as the gravel content increased from 0% to 50%, the tensile strength of specimens decreased from 122.6 kPa to 49.8 kPa linearly. The peak tensile strain and ultimate tensile strain all decrease with the increase of the gravel content. From the analysis of fracture energy, it is proved that the tensile capacity of gravelly soil decreases slightly with the increasing gravel content. In the case that the sample under the maximum dry density and the water content higher than the optimum water content, the comprehensive tensile capacity of the sample is the strongest. The relevant test results can provide support for the anti-crack design of the high earth core rockfill dam.

• 한국콘텐츠학회:학술대회논문집
• /
• 한국콘텐츠학회 2003년도 춘계종합학술대회논문집
• /
• pp.209-213
• /
• 2003

컨텐츠 암호화를 통하여 컨텐츠를 보호하고 통제하려는 DRM 관련 기술은 현재 몇 가지 제품으로 상용화 되어 서비스 되고 있는 상황이다. 하지만 현재지 DRM기술은 최종 사용자로부터의 컨텐츠 보호에 중점을 두고 있어, 컨텐츠 유통에 참여하는 창조자, 제공자, 분배자 등 주체들에게 저작권의 보호 및 관리 문제, 올바른 유통 체계 확립 문제 등을 효과적으로 해결할 수 있는 수단을 제공하지 뭇하고 있다. 본 논문은 DRM을 기반으로 컨텐츠를 유통하기 위한 컨텐츠와 메타데이터에 대한 처리 방법을 제시하고 다양한 컨텐츠 유통 모델에서 쉽게 컨텐츠를 유흥시킬 수 있는 환경을 제안한다.

• 지능정보연구
• /
• 제14권4호
• /
• pp.135-145
• /
• 2008

인터넷의 활성화로 멀티미디어 콘텐츠의 저작권 보호에 대한 필요성이 점차 증대되고 있다. 본 연구에서는 디지털 워터마킹 기술을 이용하여 사용자 레벨에 따라 차별화된 콘텐츠 서비스를 제공하여 저작권을 보호할 수 있는 새로운 기술을 연구하였다. 여기서는 유료 사용자와 무료 사용자의 두 계층으로 분리하여 서비스를 할 수 있도록 하였으며, 유료 사용자는 고품질의 서비스를 무료 사용자는 저품질의 콘텐츠나 가시적인 로고가 들어가 있는 콘텐츠를 서비스 받도록 차별화할 수 있다. 디지털 워터마킹 기술은 콘텐츠의 품질을 높일 수 있는 정보를 은닉하는 데 활용된다.

• 전기학회논문지
• /
• 제65권8호
• /
• pp.1407-1417
• /
• 2016

In this paper, we propose a multi-level content transmission mechanism for intelligent quality of service (QoS) in social networking services (SNSs). Because existing SNSs and related work send image content to a client with a single fixed mechanism, they cannot consistently support content accessibility according to different conditions of QoS factors such as network congestion and throughput. In the proposed image transmission mechanism, our communication middleware (CM) provides an SNS developer with three transmission modes so that an SNS server or client can dynamically change the quality of images if required. In each transmission mode, an SNS server can send images to a requesting client with original high quality, thumbnail quality, or send only text information. With varying qualities of downloaded images, an SNS developed on top of CM can provide users with consistent QoS for access to SNS content.

• ETRI Journal
• /
• 제41권3호
• /
• pp.348-357
• /
• 2019

Fog radio access network (F-RAN) architectures provide markedly improved performance compared to conventional approaches. In this paper, an efficient genetic algorithm-based content distribution scheme is proposed that improves the throughput and reduces the transmission delay of a F-RAN. First, an F-RAN system model is presented that includes a certain number of randomly distributed fog access points (F-APs) that cache popular content from cloud and other sources. Second, the problem of efficient content distribution in F-RANs is described. Third, the details of the proposed optimal genetic algorithm-based content distribution scheme are presented. Finally, simulation results are presented that show the performance of the proposed algorithm rapidly approaches the optimal throughput. When compared with the performance of existing random and exhaustive algorithms, that of the proposed method is demonstrably superior.

• 한국치위생학회지
• /
• 제9권3호
• /
• pp.229-247
• /
• 2009

The purpose of this study is to provide the improvement basis for Dental Hygiene education program by analyzing the current implement status of Dental Hygiene curriculum in Korea and comparing the status with the US ADA standard. The researcher analyzed the Dental Hygiene syllabus limiting "Dental prophxis", "Comprehensive dental hygiene" subjects only from 31 universities which offer 3 years program. The main interest was to figure the implementing status of the curriculum and to compare the actual teaching content with the CODA 2-17 standard. The results show that there are a number of problems in implementing the Dental Hygiene courses among different universities. First, there is a significant inconsistence among schools in terms of course title, total credit, hours, the ratio for theory and practice, etc. In addition, there is a big gap between the actual content of Dental Hygiene courses and the essential/required content of CODA 2-17 standard. For instance, most of the Dental Hygiene programs in Korea cover the overall assessment stage content and some of implementation stage content. However, very few programs deal with the planning and evaluation stage content. To improve these problematic circumstance a number of suggestions were made. Developing the standardized curriculum for the Dental Hygiene program might be one of the major solutions. Next, the regular accreditation and/or assessment system for the Dental Hygiene program should be developed. This research can provide the basis for the need to assess and improve the Dental Hygiene curriculum.

• Journal of Nutrition and Health
• /
• 제27권3호
• /
• pp.215-227
• /
• 1994

Changes in total lipid content, total cholesterol content and fatty acid composition of preterm milk were investigated during early lactation. Milk samples were collected from Korean mothers of 16 premature(34 to 36 weeks gestation age) infants on day 2 to 5(colostrum) and at 6 weeks(mature) postpartum. We estimated the lipid nutrition of preterm milk by comparing with the lipids of term milk. The total lipid content of preterm colostrum was significantly lower than the lipid content of preterm mature milk(p<0.001). Lipid content, determined gravimetrically in colostrum and matured milk, was 1.50g/이 and 3.2g/dl, respectively. Also the total cholesterol content(mg/dl) in preterm milk tends to increase from 14.16mg/dl to 15.20mg/dl, while the total cholesterol(mg/g lipid) concentration higher significantly in colostrum(12.36mg/g) than in mature(5.73mg/g)(p<0.001). The total unsaturated fatty acid contents in preterm milk were higher in colostrum than in mature milk and the total saturated fatty acids were higher in mature milk. The average DHA contents of colostrum and matured milk was 0.64%, 0.53% and the P/M/S ratio of preterm milk were 0.63 : 1.05 : 1.00, 0.47 : 0.79 : 1.00, respectively. Also, $\omega$6/$\omega$3 ratio of preterm milk were 2.35 in colostrum and 5.81 in mature. Therefore, colostrum in preterm milk contained higher amounts of $\omega$3 PUFA than mature milk. The levels of total lipid in preterm milk were higher than term milk. Also, preterm milk is richer in cholesterol, and long chain polyunsaturated fatty acid than term. It appears that the milk secreted by mothers who delivered prematurely differs from milk in several important respect. These components may serve as precursors for membrane, myelin development in the preterm infants. Therefore, it would be necessary to study further into the machanism of how the gestation age might affect to the lipid composition in human milk. These data may provide a basis for better construction of infant formaulas to provide more adequately for the lipid requirements of the Korean premature infant.

• Journal of Communications and Networks
• /
• 제17권1호
• /
• pp.67-74
• /
• 2015

In this paper, we propose a web-based content syndication system in which users can easily choose Internet protocol television (IPTV) contents. This system generates personalized content guide to provide a list of IPTV contents with respect to users' interests and statistics information of their online social community. For this, IPTV contents and relevant metadata are collected from various sources and transformed. Then, the service and content metadata are processed by user metadata including audience measurement and community metadata. The metadata flows are separated from content flows of transport network. The implementation of IPTV content syndication system demonstrates how to arrange IPTV contents efficiently from content providers to the end user's screen. We also show that the user metadata including online community information are important for the system's performance and the user's satisfaction.

• 한국융합학회논문지
• /
• 제9권6호
• /
• pp.17-23
• /
• 2018

본 논문에서는 기존의 콘텐츠 관리 시스템의 한계를 극복하고자, 하나의 콘텐츠 관리 시스템의 트랜스코딩 엔진을 이용하여 IPTV, WEB, Mobile, Smart Device 등에 서비스할 수 있는 콘텐츠 관리 시스템(CMS)을 개발한 사례를 소개한다. 개발된 CMS는 하나의 콘텐츠를 동시에 여러 개의 콘텐츠로 트랜스코딩하여 각 각의 디바이스에 자동으로 인지하여 최상의 콘텐츠를 서비스함으로써 CMS 추가 도입에 대한 부담감을 줄이고, 관리자의 개입을 최소화시킴으로써 효율적인 콘텐츠 관리를 할 수 있도록 설계 되었다. 스튜디오에서 제작된 콘텐츠에 대한 자동화시스템과 모바일에서 촬영된 영상에 대한 자동관리 기능으로 활용에 중점을 두고 있으며, 추후 콘텐츠 생산에 대한 기능을 추가함으로써 콘텐츠에 대한 One-Stop Service를 할 수 있도록 발전시켜갈 계획이다.

• 한국지구과학회지
• /
• 제38권5호
• /
• pp.367-377
• /
• 2017

The purpose of this research is to investigate characteristics of science content knowledge and pedagogical content knowledge shown in the primary school science classes. Through analysis of classroom teaching, explore the features and differences between primary and secondary school science PCK. Using open-ended interviews with the teachers and group discussions on a regular basis to analyze and compare classes of five primary school teachers, the relationship between CK and PCK. Regardless of the school level the teacher's PCK and professionalism is required with varying focus and emphasis. The features of the primary school teacher's PCK are as follows: Firstly, elementary teach secondary teach content, teachers value pedagogical knowledge (PK) content knowledge (CK). The primary school PCK requires more of understanding of students and teaching methods that to subject areas. PCK be without content knowledge, and the teacher's PCK is subject-specific In addition to the characteristics of PCK in the primary school science teaching, ways to set up professional exchange or collaboration between primary and secondary teachers, and to provide supplementary in-service training focused on content knowledge for primary school teachers.