• 제목/요약/키워드: TCP

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홈오토메이션을 위한 영상/로봇제어 시스템의 설계와 구현 (Design and Implementation of Visual/Control Communication Protocol for Home Automated Robot Interaction and Control)

  • 조명지;김성환
    • 인터넷정보학회논문지
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    • 제10권6호
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    • pp.27-36
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    • 2009
  • 기존의 음성통신 위주의 공중전화망 (PSTN) 시스템은 TCP/IP 프로토콜을 사용하는 데이터통신 위주의 IP 망으로 진화하고 있으며, IP 망을 이용하여, 멀티미디어 서비스를 제공할 수 있는 VoIP (voice over IP) 서비스를 제공한다. 본 논문은 원격지의 사용자에게 해당 가정의 로봇이 제공하는 VoIP 서비스를 사용하여, 홈오토메이션 기능을 제공하기 위한 시스템을 제안한다. 본 논문에서 구현한 시스템은, VoIP서비스를 위한 대표적인 시그널링 표준인 HTTP (hyper-text transfer protocol) 기반의 SIP (session initiation protocol) 를 이용하여, 시그널링 프로토콜을 구성하였으며, 원격사용자와 로봇 내 장착된 카메라를 통해 가정의 환경을 모니터링하기 위한 RTP (real-time transport protocol)과 홈오토메이션 신호전달을 위한 DTMF (dual tone multi-frequency) 신호 전송프로토콜을 제공한다. 본 논문에서 제안한 시스템을 실제 구현하여 로봇의 통신모듈로 구성하였으며, KT 망을 통한 영상통화 및 제어신호 전달품질측정결과, 대부분의 트래픽환경에도 원활한 로봇제어 및 평균 MOS 9.15 이상의 우수한 영상품질을 보임을 확인하였다.

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CORBA 기반의 멀티미디어 멀티캐스트 애플리케이션을 위한 통신 서비스 아키텍쳐 (Communication Service Architecture for CORBA -Based Multimedia Multicast Application)

  • 마영식;강우식;안순신
    • 한국정보과학회논문지:컴퓨팅의 실제 및 레터
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    • 제5권6호
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    • pp.771-781
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    • 1999
  • 오늘날의 컴퓨팅 환경은 통신 네트워크의 복잡성과 다양한 멀티미디어 서비스 처리를 위해 객체지향 기술을 분산 시스템에 도입하고 통신망을 소프트웨어 계층적 모델로 구조화한 개방형 정보 통신망 구조 연구가 활발히 진행되고 있다. 본 논문은 분산환경에서 멀티미디어 스트림 데이타를 전송하기 위한 아키텍쳐에 관한 모델의 설계 및 구현에 관한 것으로 분산 환경에서 멀티미디어 스트림 데이타를 효율적으로 전송할 수 있는 구조를 제시하고 있다. 설계한 구조는 Point-to-Point와 멀티캐스트를 지원하며 컴퓨터 통신망에서 멀티캐스트 연결을 효율적으로 관리하고 추후 기능 확장 및 기능 변경이 용이하도록 모듈화하고 유연성을 가지는 연결 관리 구조를 설계하고 구현하였다. 신호기능은 CORBA(Common Object Request Broker Architecture)의 ORB를 이용하여 실현하였으며, 데이타 전송 기능은 TCP/IP연결을 이용하였다. 이렇게 신호처리 부분과 데이타 전송 부분을 독립적으로 만들어서 하부망 기술에 독립적인 연결 관리 구조를 채택하고 있으므로 향후 다른 환경에서도 신호처리 부분을 그대로 적용할 수 있다. 분산 객체 개념을 적용하여 연결 관리 기능을 분산 객체화 하였으며 각 분산 객체간 인터페이스를 OMG(Object Management Group) IDL(Interface Definition Language)로 정의함으로써 유연성을 갖도록 하였다.AbstractThis paper proposes communication service architecture to support dynamic communication configuration and multiple connection management which are required to handle a variety of multimedia multicast application. Our communication service architecture was designed to fulfil the objectives as the following:- To build a common networking system for various multimedia multicast services- To build a platform for rapid service development and provisioning- To provide service networking independent on transport network technologiesWe implemented communication service architecture based on Common Object Request Broker Architecture (CORBA) for multimedia multicast applications. Our communication service architecture is distributed and object-oriented for extensibility and easy modification. The interfaces between the distributed objects are specified in (Object Management Group) OMGs Interface Definition Language.

인터넷 트래픽 제어에 관한 연구: IP 주소 위조 기법을 사용한 유해 정보 차단 시스템 (A Study ou Iuternet Traffic Coutrol: Blockiug of harmful information based on IP spoofing)

  • 백선욱
    • 한국산학기술학회논문지
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    • 제5권5호
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    • pp.447-453
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    • 2004
  • 본 논문에서는 사용자가 유해한 사이트에 접근하는 것을 효과적으로 방해하는 새로운 유해 정보 차단 시스템을 제안한다. 본 차단 서버 시스템은 설치된 망의 외부로 전송되는 모든 트래픽의 URL 정보를 감시하다가 외부의 유해한 사이트에 접속을 시도하는 내부 사용자를 발견하면 마치 유해 사이트로부터의 응답인 것처럼 위조된 TCP RST 세그먼트를 그 사용자에게 전송하여 사용자가 스스로 접속을 포기하도록 유도하는 IP 주소 위조(IP spoofing)기술을 사용하였다. 본 차단 시스템은 망 내부의 각 사용자 시스템에는 유해 정보 차단과 관련된 소프트웨어를 설치할 필요가 없이 하나의 서버에만 설치하면 되므로 쉽게 설치 및 유지 보수가 가능하다. 또한, 정상적인 트래픽 흐름에는 거의 영향을 미치지 않는 장점이 있다. 본 IP spoofing 기법에 기반하고 있으므로 정상적인 접속요청도 방해하는 해킹 도구로 악용될 수 도 있는데, 이러한 가능성을 예방할 수 있는 방안도 함께 제안하였다.

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정수장 감시제어망의 관리와 보안개선을 위한 산업용 보안 L2스위치 개발 및 적용사례 (The development of industrial secure L2 switch and introduction example for management and security improvement of supervisory control network in purification plant)

  • 김윤하;유철;오은;김찬문;박익동;김용성;최현주
    • 상하수도학회지
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    • 제33권5호
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    • pp.329-339
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    • 2019
  • Recently, the advancement of information and communication technology(ICT) is expanding the connectivity through Internet of Things(IoT), and the media of connection is also expanding from wire/cable transmission to broadband wireless communication, which has significantly improved mobility. This hyperconnectivity has become a key element of the fourth industrial revolution, whereas the supervisory control network of purification plants in korea is operated as a communication network separated from the outside, thereby lagging in terms of connectivity. This is considered the best way to ensure security, and thus there is hardly any consideration of establishing alternatives to operate an efficient and stable communication network. Moreover, security for management of a commercialized communication network and network management solution may be accompanied by immense costs, making it more difficult to make new attempts. Therefore, to improve the conditions for the current supervisory control network of purification plants, this study developed a industrial security L2 switch that supports modbus TCP(Transmission Control Protocol) communication and encryption function of the transmission section. As a result, the communication security performance improved significantly, and the cost for implementing the network management system using Historical Trend and information of HMI(Human Machine Interface) could be reduced by approximately KRW 200 million. The results of this study may be applied to systems for gas, electricity and social safety nets that are infrastructure communication networks that are similar to purification plants.

Verification of failover effects from distributed control system communication networks in digitalized nuclear power plants

  • Min, Moon-Gi;Lee, Jae-Ki;Lee, Kwang-Hyun;Lee, Dongil;Lim, Hee-Taek
    • Nuclear Engineering and Technology
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    • 제49권5호
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    • pp.989-995
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    • 2017
  • Distributed Control System (DCS) communication networks, which use Fast Ethernet with redundant networks for the transmission of information, have been installed in digitalized nuclear power plants. Normally, failover tests are performed to verify the reliability of redundant networks during design and manufacturing phases; however, systematic integrity tests of DCS networks cannot be fully performed during these phases because all relevant equipment is not installed completely during these two phases. In additions, practical verification tests are insufficient, and there is a need to test the actual failover function of DCS redundant networks in the target environment. The purpose of this study is to verify that the failover functions works correctly in certain abnormal conditions during installation and commissioning phase and identify the influence of network failover on the entire DCS. To quantify the effects of network failover in the DCS, the packets (Protocol Data Units) must be collected and resource usage of the system has to be monitored and analyzed. This study introduces the use of a new methodology for verification of DCS network failover during the installation and commissioning phases. This study is expected to provide insight into verification methodology and the failover effects from DCS redundant networks. It also provides test results of network performance from DCS network failover in digitalized domestic nuclear power plants (NPPs).

Prediction and visualization of CYP2D6 genotype-based phenotype using clustering algorithms

  • Kim, Eun-Young;Shin, Sang-Goo;Shin, Jae-Gook
    • Translational and Clinical Pharmacology
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    • 제25권3호
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    • pp.147-152
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    • 2017
  • This study focused on the role of cytochrome P450 2D6 (CYP2D6) genotypes to predict phenotypes in the metabolism of dextromethorphan. CYP2D6 genotypes and metabolic ratios (MRs) of dextromethorphan were determined in 201 Koreans. Unsupervised clustering algorithms, hierarchical and k-means clustering analysis, and color visualizations of CYP2D6 activity were performed on a subset of 130 subjects. A total of 23 different genotypes were identified, five of which were observed in one subject. Phenotype classifications were based on the means, medians, and standard deviations of the log MR values for each genotype. Color visualization was used to display the mean and median of each genotype as different color intensities. Cutoff values were determined using receiver operating characteristic curves from the k-means analysis, and the data were validated in the remaining subset of 71 subjects. Using the two highest silhouette values, the selected numbers of clusters were three (the best) and four. The findings from the two clustering algorithms were similar to those of other studies, classifying $^*5/^*5$ as a lowest activity group and genotypes containing duplicated alleles (i.e., $CYP2D6^*1/^*2N$) as a highest activity group. The validation of the k-means clustering results with data from the 71 subjects revealed relatively high concordance rates: 92.8% and 73.9% in three and four clusters, respectively. Additionally, color visualization allowed for rapid interpretation of results. Although the clustering approach to predict CYP2D6 phenotype from CYP2D6 genotype is not fully complete, it provides general information about the genotype to phenotype relationship, including rare genotypes with only one subject.

Profile of phenolic compounds, antioxidant and SOD activity of millet germplasm

  • Lee, Myung-Chul;Choi, Yu-Mi;Yun, Hyemyeong;Hyun, Do-Yoon;Lee, Sukyeung;Oh, Sejong
    • 한국자원식물학회:학술대회논문집
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    • 한국자원식물학회 2019년도 춘계학술대회
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    • pp.107-107
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    • 2019
  • Millets are provided considerable amounts of nutrients and gluten-free cereal products and their rich non-nutritional compounds having proven health benefits, especially phenolic compounds. The aim of present investigation was to determine phenolic composition and antioxidant and SOD activity of three different millet of genetic resources namely, foxtail, proso and finger millet. Phenolic compounds were extracted from dehulled grain of genetic resources using methanol and examined for their total phenolic content (TPC), antioxidant activities and superoxide dismutase (SOD)-like activity. The TPC range of hog millet, finger millet and finger millet range from 3.3 to 25.1, 11.1 to 29.0 and 3.8 to 94.3 gallic acid equivalent (GAE)mg/g, respectively. Most of TCP content in dehulled millet grains was distributed from 10 to 20 gallic acid equivalent (GAE)/g, but two accessions of finger millet (IT235690 and 235689) were showed over than 90. The antioxidant activities were measured by 1,1-diphenyl-2-picrylhydrazyl (DPPH) free radical scavenging activity. Finger millet and hog millet showed 26.4% and 26.7% in the mean of DPPH scavenging activity percentage, but foxtail millet was 13%. The finger millet showed the higher value than hog and foxtail millet in superoxide dismutase (SOD)-like activity. Particularly, two accessions of finger millet (IT235690 and 235689) showed the highest phenolic content and antioxidant activities among the used millet genetic resources and will be primary resources for finger millet breeding to develop the appropriate breeding strategies.

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Development of a user-friendly training software for pharmacokinetic concepts and models

  • Han, Seunghoon;Lim, Byounghee;Lee, Hyemi;Bae, Soo Hyun
    • Translational and Clinical Pharmacology
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    • 제26권4호
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    • pp.166-171
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    • 2018
  • Although there are many commercially available training software programs for pharmacokinetics, they lack flexibility and convenience. In this study, we develop simulation software to facilitate pharmacokinetics education. General formulas for time courses of drug concentrations after single and multiple dosing were used to build source code that allows users to simulate situations tailored to their learning objectives. A mathematical relationship for a 1-compartment model was implemented in the form of differential equations. The concept of population pharmacokinetics was also taken into consideration for further applications. The source code was written using R. For the convenience of users, two types of software were developed: a web-based simulator and a standalone-type application. The application was built in the JAVA language. We used the JAVA/R Interface library and the 'eval()' method from JAVA for the R/JAVA interface. The final product has an input window that includes fields for parameter values, dosing regimen, and population pharmacokinetics options. When a simulation is performed, the resulting drug concentration time course is shown in the output window. The simulation results are obtained within 1 minute even if the population pharmacokinetics option is selected and many parameters are considered, and the user can therefore quickly learn a variety of situations. Such software is an excellent candidate for development as an open tool intended for wide use in Korea. Pharmacokinetics experts will be able to use this tool to teach various audiences, including undergraduates.

Safety and efficacy of fimasartan with essential hypertension patients in real world clinical practice: data from a post marketing surveillance in Korea

  • Han, Su-Eun;Jeong, Seung Hee;Kang, Hye Jeong;Hong, Myung Sook;Paek, Eunah;Cho, Hijung;Choe, Seong Choon
    • Translational and Clinical Pharmacology
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    • 제26권3호
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    • pp.118-127
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    • 2018
  • The safety and efficacy of fimasartan have been evaluated through post-marketing surveillance in real world clinical practice. The multi-center, prospective, open-label and non-interventional study. A total of 3,945 patients (3,729 patients for safety assessment and 3,473 patients for efficacy assessment) were screened in patients with essential hypertension in 89 study centers from 9 September 2010 through 8 September 2016. Among the total patients, 2,893 patients (77.6%) were administered fimasartan for 24 weeks or longer and were classified as 'patients with long-term follow-up', and the additional safety and efficacy analysis were performed. The improvement was defined as systolic blood pressure (SBP) controlled to ${\leq}140mmHg$ or decreased SBP differences ${\geq}20mmHg$ after treatment or diastolic blood pressure (DBP) controlled to ${\leq}90mmHg$ or decreased DBP differences ${\geq}10mmHg$ after treatment. Adverse drug reactions (ADRs) were reported in 3.8% patients; dizziness, and hypotension were the most frequently reported ADRs in total patients. The results of patients with long-term follow-up were comparable with total patients. The overall improvement rate in all efficacy assessment at the last visit was 87.1% (3,025/3,473 patients). The overall improvement rate of the patients with long-term follow-up was 88.9%. Fimasartan was well tolerated, with no new safety concerns identified and an effective treatment in the real world clinical practice for Korean patients with hypertension.

Survey on the undergraduate curriculum in clinical pharmacology and interns' prescribing ability in South Korea

  • Gu, Namyi;Kim, Kyong-Jee;Lim, Chi-Yeon;Lee, Jun Kyu;Rhee, Moo-Yong;Shin, Kwang-Hee;Lee, Seung-Hwan;Ahn, Sangzin
    • Translational and Clinical Pharmacology
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    • 제26권3호
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    • pp.128-133
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    • 2018
  • Appropriate prescription writing is one of the critical medical processes affecting the quality of public health care. However, this is a complex task for newly qualified intern doctors because of its complex characteristics requiring sufficient knowledge of medications and principles of clinical pharmacology, skills of diagnosis and communication, and critical judgment. This study aims to gather data on the current status of undergraduate prescribing education in South Korea. Two surveys were administered in this study: survey A to 26 medical schools in South Korea to gather information on the status of undergraduate education in clinical pharmacology; and survey B to 244 intern doctors in large hospitals to gather their opinions regarding prescribing education and ability. In survey A, half of the responding institutions provided prescribing education via various formats of classes over two curriculums including lecture, applied practice, group discussions, computer-utilized training, and workshops. In survey B, we found that intern doctors have the least confidence when prescribing drugs for special patient populations, especially pregnant women. These intern doctors believed that a case-based practical training or group discussion class would be an effective approach to supplement their prescribing education concurrently or after the clerkship in medical schools or right before starting intern training with a core drug list. The results of the present study may help instructors in charge of prescribing education when communicating and cooperating with each other to improve undergraduate prescribing education and the quality of national medical care.