• Title/Summary/Keyword: Use Diversity

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A Connection Management Protocol for Stateful Inspection Firewalls in Multi-Homed Networks

  • Kim, Jin-Ho;Lee, Hee-Jo;Bahk, Sae-Woong
    • Journal of Communications and Networks
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    • v.10 no.4
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    • pp.455-464
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    • 2008
  • To provide network services consistently under various network failures, enterprise networks increasingly utilize path diversity through multi-homing. As a result, multi-homed non-transit autonomous systems become to surpass single-homed networks in number. In this paper, we address an inevitable problem that occurs when networks with multiple entry points deploy firewalls in their borders. The majority of today's firewalls use stateful inspection that exploits connection state for fine-grained control. However, stateful inspection has a topological restriction such that outgoing and incoming traffic of a connection should pass through a single firewall to execute desired packet filtering operation. Multi-homed networking environments suffer from this restriction and BGP policies provide only coarse control over communication paths. Due to these features and the characteristics of datagram routing, there exists a real possibility of asymmetric routing. This mismatch between the exit and entry firewalls for a connection causes connection establishment failures. In this paper, we formulate this phenomenon into a state-sharing problem among multiple fire walls under asymmetric routing condition. To solve this problem, we propose a stateful inspection protocol that requires very low processing and messaging overhead. Our protocol consists of the following two phases: 1) Generation of a TCP SYN cookie marked with the firewall identification number upon a SYN packet arrival, and 2) state sharing triggered by a SYN/ACK packet arrival in the absence of the trail of its initial SYN packet. We demonstrate that our protocol is scalable, robust, and simple enough to be deployed for high speed networks. It also transparently works under any client-server configurations. Last but not least, we present experimental results through a prototype implementation.

The Proposal and Performance Analysis for the Detection Scheme of D-STTD using Iterative Algorithm (반복 알고리즘을 적용한 D-STTD 시스템의 검출 기법 제안 및 성능 분석)

  • Yoon, Gil-Sang;Lee, Jeong-Hwan;You, Cheol-Woo;Hwang, In-Tae
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.33 no.9A
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    • pp.917-923
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    • 2008
  • The D-STTD system obtains the diversity gain through the STTD scheme and the Multiplexing gain through parallel structure of the encoder using the STTD scheme known Alamouti Code. We are difficult to use Combining scheme of the STTD scheme for the D-STTD detection in the decoder because the D-STTD system transmits mutually different data in each other STTD encoder for multiplexing gain. Therefore, in this paper we combine the D-STTD system with Linear algorithm, SIC algorithm and OSIC algorithm known multiplexing detection scheme based on MMSE scheme and compare the performance of each system. And we propose the detection scheme of the D-STTD using MAP Algorithm and analyze the performance of each system. The simulation results show that the detector using iterative algorithm has better performance than Linear MMSE Detector. Especially, we show that the detector using MAP algorithm outperforms conventional detector.

An Introduction of Management and Policy of Biological Resources (생물자원의 관리와 정책)

  • Cho, Soon-Ro;Seol, Sung-Soo;Park, Jung-Min
    • Journal of Korea Technology Innovation Society
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    • v.11 no.2
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    • pp.219-240
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    • 2008
  • This paper aims to suggest a policy for biological resource based on a comprehensive understanding on biological resources. Biological resources are different from traditionally recognized viable organisms (Biodiversity) in ecosystems. Biological resources are culturable and replicable resources of living organisms such as tissues, cells and genes. Moreover, biological resources include human-derived biological materials. Biological resources is not simply a matter of science and technology. Biological resources should be dealt with as national resources. There are many international issues regarding biological resources, such as intellectual property rights (IPRs), safety on handling and distribution, material transfer agreements (MTAs) for mutual benefits and biological standards. Ethical debates are also being raised because biological resources are related with human-derived biological materials. Every nation has tendency to adopt its government policies to strengthen its sovereignty on biological resources and international cooperation. In addition, international linkages are essential for providing enhanced worldwide accessibility to biological resources. Japan has shown several international initiatives in the field of biological resources. Korea has just begun to design appropriate policies for the use and R&D of biological resources. Therefore, this paper suggests the following needs: 1) policy at the national level beyond the interests of researchers, 2) inter-ministerial coordination across government ministries, 3) expansion of scope and size of each BRC (Biological Resource Centers), and 4) building networks and systems such as national information center, representative centers by field, and each BRC.

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Performance Improvement of Space-Time OFDM System with Concatenated Codes (연접부호를 적용한 시공간 OFDM 시스템의 성능 개선)

  • 서완우;정연호
    • Journal of the Korea Institute of Information and Communication Engineering
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    • v.8 no.3
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    • pp.541-546
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    • 2004
  • Space-Time Coding(STC) is a technique that utilizes joint correlation of transmitted signals in both time and space domains. Through this approach, diversity and coding gains can be simultaneously obtained. In this paper, we use SPW simulation tool to implement the IEEE 802.11a system. Based on this system, OFDM system with STC and convolutional coder concatenated is implemented. The system performance is analyzed and compared with the performance of the IEEE 802.11a system. The simulation results show that the performance with concatenated codes at a data rate of 6Mbps shows approximately a 5dB gain over the system with the convolutional code only. At a data rate of 12Mbps, the performance with concatenated codes is further improved by approximately 6dB.

Traditional Foods: Historical Perspectives and Future Prospects (문화와 과학의 융합적 관점에서 본 전통음식의 역사 및 미래)

  • Kim, Hee Sup
    • Journal of the Korean Society of Food Culture
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    • v.30 no.1
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    • pp.1-7
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    • 2015
  • Traditional cuisine reflects cooking traditions shaped by political, economic, social, cultural, and environmental conditions characterized by authenticity and uniqueness. Traditional food is not only a part of our cultural heritage but also a knowledge resource. Application of food science and technology in Korean traditional foods was reviewed from six points of view, including food preservation, fermentation, changes in food materials, utilization of food functionality, and packaging and development of cooking appliances. Books from disparate times were chosen in order to cover a wide range of materials from the past to the present. Food preservation and fermentation techniques were applied to various food materials. Combination of science and skills contributes to the accessibility of diverse food materials and better quality foods. Koreans use assorted and resilient plants, which have an abundance of functional substances such as food materials. Among cooking appliances, microwave oven and refrigerator are the most innovative products with huge influences on food eating patterns as well as lifestyle. Packaging effectively reduces post-harvest preservation losses, and better packaging has technical improvements for storage and distribution. Kimchi was chosen as an example in order to study technology from the past to the present. Availability of Kimchi cabbage, enrichment of functional ingredients, identification of useful microbial species, standardization of recipe for commercialization, prevention of texture softening, introduction of salted Kimchi cabbage and Kimchi refrigerators, and packaging were reviewed. The future of traditional foods in the market will be competitive. First, traditional foods market should be maintained to protect the diversity of food materials. Secondly, tailored foods for individuals should be considered using foods with functional properties. Information on health benefits would provide insights into health and traditional food products. Third, speedy transfer of new technology to the traditional food industry is needed to ensure food quality production and new opportunities in the market. Fourth, safety of traditional foods should be ensured without sacrificing the essential characteristics of culturally important foods. Improvement of logistics, distribution, and facility should be carried out. As demand for convenience foods increases, traditional foods should be developed into products.

Senior Men's Concern About Appearance and Their Cosmetics Buying Behavior

  • Kim, HyoKyoung;Shin, SaeYoung
    • Journal of Fashion Business
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    • v.19 no.3
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    • pp.88-100
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    • 2015
  • In our increasingly aged society, the term centenarian, meaning people 100 years old or older, is used more and more frequently. Indeed, anticipating long life, middle-aged to advanced-age people have changed their lifestyles to purchase goods for themselves. In addition, as the social trend of careful grooming for positive appearance spreads within the Korean society, the demand for senior male cosmetic products is likely to grow as the society ages further. However, previous large studies on the market for senior male cosmetics are limited. Since information is lacking about senior male consumers' awareness of cosmetics, this study examined their use of cosmetic products, purchase behaviors, and demand for cosmetics in order to explore correlations among interest levels in appearance, cosmetic purchase behavior, and cosmetic demand levels through diverse factors related to multiple variables. The results of this study were as follows : First, the more senior men managed their practical appearance, the more frequent their functional and psychological purchase behaviors. Second, the higher their practical purchase behavior, the stronger their demand for reasonable cosmetic prices. Third, the higher their value-oriented purchase behavior, the stronger the demand for greater product diversity. This study investigated men aged 50 or older residing in Seoul. Therefore, generalizing the findings of this study will be limited. Relevant subsequent studies should examine men aged 50 or older in each Korean region and more clearly identify the correlations among interest in appearance, cosmetic product purchase behavior, and cosmetic product demand using various factors related to multiple variables.

Calculus of Communicating Systems Domain in PtolemyII (PtolemyII의 CCS 도메인)

  • 황혜정;김윤정;남기혁;김일곤;최진영
    • Journal of KIISE:Computer Systems and Theory
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    • v.31 no.5_6
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    • pp.335-346
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    • 2004
  • PtolemyII is an environment that supports heterogeneous modeling and design of concurrent systems such as embedded system. PtolemyII has several Domains which are physical rules to determine the way of communicating between components. PtolemyII has 11 domains such as PetriNet, Timed Multitasking, SR etc. Components of System can be specified using appropriate domains for their properties. Communicating Sequential Processes(CSP) is implemented as formally designed CSP domain, in PtolemyII. But CCS didn't be implemented as a domain. It is a kind of Process Algebra language which can be used for specifying and verifying concurrent systems formally. Thus, in this paper we implemented CCS domain. And that permitted developers using PtolemyII to use the same modeling pattern used in PtolemyII and to make system specifications in the base of the formal semantics of CCS. This caused the diversity of PtolemyII domains and the power of expression was improved. This paper will explain the structure of CCS domain implemented in PtolemyII and the way of implementing it.

A Study on Characteristics of the Type of Interactive Broadcast Program in Korea (국내 양방향 방송 프로그램 유형 특징에 관한 연구)

  • PARK, JIN SIK;KIM, SUNG HOON
    • The Journal of the Convergence on Culture Technology
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    • v.5 no.4
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    • pp.209-215
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    • 2019
  • The purpose of this study is to suggest the development of interactive services and technologies in the media industry. Through the analysis of domestic two-way broadcasting contents service, this study analyzed platform and services type according to service type of terrestrial broadcasting, SO operator and Telco. Also, by identifying the characteristics of interactive programs(open, interactive, personalized, stereoscopic), this study propose important convergence possibilities of the future providers and development plans through supporting technologies and services for each characteristic. In the case of terrestrial broadcasters, ARS, web sites and mobile apps were mostly provided in both directions, and SO and satellite broadcasting operators were found to provide diversity in interactive service operation using data domain. In the case of IPTV companies, most of them provide interactive services with additional video or information service through adjustment button or app, and cable TV operators had more adjustment data broadcasting than exclusive use data broadcasts. Therefore, domestic interactive broadcasting service type needs convergence type of revenue model needs and needs to be converted into new competitive interactive broadcasting program service environment.

Exploring Convergence R & D area via Data-driven Tech mining: The case of landslide prevention technology linked to ICT (데이터 기반 테크마이닝(tech-mining)을 통한 융합 R&D 영역 탐색: ICT 기반 산사태 예방 기술 사례를 중심으로)

  • Choi, Jaekyung;Seo, Seongho;Kang, Jongseok;Chung, Hyunsang
    • Journal of the Korean Society of Industry Convergence
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    • v.22 no.5
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    • pp.483-490
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    • 2019
  • Due to the high complexity and diversity of the problems of the future society, it is getting harder to solve with the traditional single technology. In recent years, there has been a growing interest in convergence technology, which combines or connects different types of technologies to create new technologies and industries. In this study, we explored the convergence R&D area of ICT technology related to landslide prevention/response. It is true that the world has been exposed to various disasters due to recent climate change. As a result, there is a tendency to use Big Data and ICT for disaster preparedness and recovery. Especially, in the case of landslides, it is a natural disaster that requires research not only to study actual landslides but also to predict potential landslides. Therefore, in this study, we analyzed what kind of convergence R&D is being carried out in the field of ICT for preventing and responding to landslide. Therefore, in this study, Web of Science article data were analyzed by using the scientometric analysis and 51 landslide-related ICT convergence R&D areas were derived.

A Study on Space Evaluation Factors and Case Analysis of Teen Space in Public Libraries in Korea (공공도서관 청소년자료실의 공간 평가요소 분석 및 사례조사 연구)

  • Kim, Gi Young;Lee, Gi Ri;Kim, Yeon Ji;Park, Ok Nam
    • Journal of the Korean Society for Library and Information Science
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    • v.53 no.3
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    • pp.215-245
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    • 2019
  • The purpose of this study is to derive evaluation elements on teen space in public libraries in Korea and to study current status and implications for teen space in public libraries. To this end, six items of space evaluation factors; Convenience, Accessibility, Safety, Diversity, Comfort and Emotionality - were derived based on the teen space guidelines by the Young Adult Library Service Association and previous studies. The research also conducted a case study on teen spaces of five public libraries in Seoul. As a result, teen space in libraries requires use guidance and convenience facilities, access to information resources, maintenance of user guidelines, various spaces for teens, pleasant library environment and learning motivation promotion, and provision space to support all necessary resources of teens.