• Title/Summary/Keyword: the objects of the connection

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THE MILLIMETER-RADIO EMISSION OF BL LACERTAE DURING TWO γ-RAY OUTBURSTS

  • Kim, Dae-Won;Trippe, Sascha;Lee, Sang-Sung;Park, Jong-Ho;Kim, Jae-Young;Algaba, Juan-Carlos;Hodgson, Jeffrey A.;Kino, Motoki;Zhao, Guang-Yao;Wajima, Kiyoaki;Kang, Sincheol;Oh, Junghwan;Lee, Taeseok;Byun, Do-Young;Kim, Soon-Wook;Kim, Jeong-Sook
    • Journal of The Korean Astronomical Society
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    • v.50 no.6
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    • pp.167-178
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    • 2017
  • We present a study of the inexplicit connection between radio jet activity and ${\gamma}$-ray emission of BL Lacertae (BL Lac; 2200+420). We analyze the long-term millimeter activity of BL Lac via interferometric observations with the Korean VLBI Network (KVN) obtained at 22, 43, 86, and 129 GHz simultaneously over three years (from January 2013 to March 2016); during this time, two ${\gamma}$-ray outbursts (in November 2013 and March 2015) can be seen in ${\gamma}$-ray light curves obtained from Fermi observations. The KVN radio core is optically thick at least up to 86 GHz; there is indication that it might be optically thin at higher frequencies. To first order, the radio light curves decay exponentially over the time span covered by our observations, with decay timescales of $411{\pm}85$ days, $352{\pm}79$ days, $310{\pm}57$ days, and $283{\pm}55$ days at 22, 43, 86, and 129 GHz, respectively. Assuming synchrotron cooling, a cooling time of around one year is consistent with magnetic field strengths $B{\sim}2{\mu}T$ and electron Lorentz factors ${\gamma}$ ~ 10 000. Taking into account that our formal measurement errors include intrinsic variability and thus over-estimate the statistical uncertainties, we find that the decay timescale ${\tau}$ scales with frequency ${\nu}$ like ${\tau}{\propto}{\nu}^{-0.2}$. This relation is much shallower than the one expected from opacity effects (core shift), but in agreement with the (sub-)mm radio core being a standing recollimation shock. We do not find convincing radio flux counterparts to the ${\gamma}$-ray outbursts. The spectral evolution is consistent with the 'generalized shock model' of Valtaoja et al. (1992). A temporary increase in the core opacity and the emergence of a knot around the time of the second ${\gamma}$-ray event indicate that this ${\gamma}$-ray outburst might be an 'orphan' flare powered by the 'ring of fire' mechanism.

A Study on Utilization of GNSS and Spatial Image for River Site Decision Supporting (하천 현장업무 의사지원을 위한 GNSS와 공간영상 활용방안에 관한 연구)

  • Park, Hyeon-Cheol;Choung, Yun-Jae;Jo, Myung-Hee
    • Journal of the Korean Association of Geographic Information Studies
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    • v.14 no.1
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    • pp.118-129
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    • 2011
  • This Study has developed the information system of the rivers based on 3D image GIS by converging the latest information technology of GIS(Geographic Information System), RS(Remote Sensing), GNSS(Global Navigation Satellite System), aerial laser survey(LiDAR) with real time network technology in order to understand the current situation of all the four major rivers and support the administrative management system. The said information system acquires the high resolution aerial photographs of 25cm, aerial laser survey and water depth surveying data to express precise space information on the whole Youngsan River which is the leading project site out of the four river sites. Monitoring the site is made available on the transporting means such as a helicopter, boat or a bus in connection with locational coordinate tracking skill for the moving objects in real time using GNSS. It makes monitoring all the information on the four river job sites available at a glance, which can obtain the reliability of the people to such vast areas along with enhancing the recognition of the people by publicity of four Rivers Revitalizing Project and reports thereof.

A Study on Improvement of Satellite Surveying Infrastructure through Analysis of Operation Status of GNSS CORS (GNSS 상시관측소 운영 현황 분석을 통한 위성측량 인프라 개선방안 연구)

  • Park, Joon Kyu;Um, Dae Yong
    • Asia-pacific Journal of Multimedia Services Convergent with Art, Humanities, and Sociology
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    • v.7 no.11
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    • pp.933-940
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    • 2017
  • The modern society is changing paradigm by the 4th industrial revolution. In these changes, the importance of geospatial information leading to the fusion and connection of persons and objects is increasing day by day. GNSS CORS(Continuously Operating Reference Station) plays a pivotal role in the geospatial information by providing basic data for surveying control points, mapping, navigation, geophysical research, and so on. On the other hand, the satellite surveying technologies are developing rapidly and it is necessary to investigate the status of the satellite surveying environment and search for future directions. In this study, the environment related to satellite survey by operation status of domestic and overseas CORS(Continuously Operating Reference Station) was tried to analyze. Through the research, The operation status of NGII and IGS CORS were presented. It was found that the availability ratio of multiple satellites to the CORS of NGII are lower than that of IGS CORS. Considering the improvement of positioning performance by using multiple GNSS, it is necessary to use multi-satellites in the future.

Ch'oe Han-gi's Reflection on Relationalities in Existence (최한기의 존재론적 관계성 성찰)

  • Rhee, Myung-Su
    • The Journal of Korean Philosophical History
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    • no.59
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    • pp.395-423
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    • 2018
  • Since the middle of the 19th century, East Asia, especially Korea, was oppressed externally by the imperialism of Japan and others while internally long-lasting political convention like in-law government was driving the country into troubles at home and abroad. Witnessing such a situation and building up scholarly capability through reading over nearly all spheres, a Confucian philosopher, Ch'oe Han-gi (崔漢綺, 1803-1877), philosophized about the clue to the solution of such a choking phenomenon. Ch'oe believed that there was movement, ki (matter, material force, energy) of revolving transformation inherent in all things, people, or objects. Grasping even the principle and order of existence inherent in things from the viewpoint of ki, he tried to change the traditional theory on the law of existence of things that there existed an ontological reason lacking in motility, which was more dominant than anything existing in the universe and which ruled over the world. From this, he elucidated that the Way, an identity that rules over all affairs and things, was not simply one but diverse. This means, on one hand, that he tentatively accepted the relativity of things. On the other hand, he also taught us "oneness in all things" in which all including human beings exist in close connection to each other transcending the relativity or "agreement" in which they exist in harmony as one and "unity" in which they are united into one.

Quality Improvement in Patient Care Services : Obstacles and Approaches (진료의 질관리에 대한 시론 -장애와 접근-)

  • 한달선
    • Health Policy and Management
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    • v.2 no.2
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    • pp.112-130
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    • 1992
  • Patient care services are provided to individual patients in response to their health needs produced by illnesses or injuries. The services are often addressed to very serious conditions, and also they constitute the most expensive component of health care services. Therefore, the importance of quality is emphasized, but there are many indications that patient care quality is far from a satisfactory state in most of the countries. Based upon this observation, it is attempted to examine obstacles and approaches to quality improvement in patient care services. In doing so, following Taguchi's(1986) definition of product quality, quality of patient care services is conceived of as better when the less is the sociental loss attributalbe to variability of intended function and harmful side effects they emhibit after being delivered. Some distinguishing features of medical care sector pose difficulties in implementing effective quality improvement programs in patient care services. Nevertheless, newly proposed method of quality management, based on industrial quality management approach, seems to have a great deal of potential to effectively cope with such difficulties. This method, unlike the traditional approach to quality assurance, focuses on total organisational processes, not individuals, as the obproach to quality assurance, focuses on total organizational processes, not individuals, as the objects of quality improvement; variation, not comparison with standards, in quality measurement; and continuous improvement, not removing only bad quality care, as an ideal. Prerequisite to a successful use of any quality mangement method is motivating providers to improve quality. Conceivable approaches for such motivation are self-regulation, external controls and promotion of competition. Since these approaches are not mutually exclusive, they may be employed in an appropriate combination. In Korea, medical care providers are now functioning under the circumstances where they have little reason for making efforts to improve quality of their services. Once these circumstantial conditions are changed to exert pressures on providers to improve quality, the use of adequate quality management method becomes an issue. In this connection, much attention shoould be directed to the newly proposed method described above. In all these efforts for improving quality of patient care services, health insurance would be able to play a pivotal role. Poviders of medical care, buth indiciduals and organizations, are usually very responsive to the measures that affect their financing, and thus health insurance can be a strong instrument for motivationg providers to improve quality. Also, the insurance continuously acquires data on patient care, which could be processed to produce information required to effective quality control.

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Contents Recommendation Search System using Personalized Profile on Semantic Web (시맨틱 웹에서 개인화 프로파일을 이용한 콘텐츠 추천 검색 시스템)

  • Song, Chang-Woo;Kim, Jong-Hun;Chung, Kyung-Yong;Ryu, Joong-Kyung;Lee, Jung-Hyun
    • The Journal of the Korea Contents Association
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    • v.8 no.1
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    • pp.318-327
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    • 2008
  • With the advance of information technologies and the spread of Internet use, the volume of usable information is increasing explosively. A content recommendation system provides the services of filtering out information that users do not want and recommending useful information. Existing recommendation systems analyze the records and patterns of Web connection and information demanded by users through data mining techniques and provide contents from the service provider's viewpoint. Because it is hard to express information on the users' side such as users' preference and lifestyle, only limited services can be provided. The semantic Web technology can define meaningful relations among data so that information can be collected, processed and applied according to purpose for all objects including images and documents. The present study proposes a content recommendation search system that can update and reflect personalized profiles dynamically in semantic Web environment. A personalized profile is composed of Collector that contains the characteristics of the profile, Aggregator that collects profile data from various collectors, and Resolver that interprets profile collectors specific to profile characteristic. The personalized module helps the content recommendation server make regular synchronization with the personalized profile. Choosing music as a recommended content, we conduct an experience on whether the personalized profile delivers the content to the content recommendation server according to a service scenario and the server provides a recommendation list reflecting the user's preference and lifestyle.

Development of Integrated Design Methodology for Relational Database Application -Focusing on Object-Oriented Analysis and Design Methodology- (관계형 데이터베이스 응용시스템을 위한 통합 설계방법론 개발 -객체지향 분석.설계 방법론을 중심으로-)

  • Joo, Kyung-Soo;Jho, Do-Hyung
    • Journal of the Korea Society of Computer and Information
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    • v.16 no.11
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    • pp.25-34
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    • 2011
  • In this paper we present an integrated design methodology for relational database based on object-oriented analysis and design. The integrated design methodology is based on business profile and has six phases. In the first phase, business use cases are identified and described by macroactivity diagrams and then the macroactivity diagrams are transformed to detailed business activity diagrams by using objects, object flows and business worker's responsibilities. In the third phase, the detailed business activity diagrams are transformed to business class diagrams that describe the static structure of the entire business system based on detailed business activity diagrams. In the four phase, the business class diagrams are transformed to class diagrams that represent the initial conceptual model of the target relational database. In the five phase, we add additional transformations on the class diagrams with generalization and specialization of associations, roles, activities, additional classes and redundant associations. Eventually, the final class diagrams are transformed to relational database schema. The methodology presented in this paper by applying that proposal for organic connection between object-oriented analysis and design methodology and relational database design methodology. And it will be able to deal with integration management. By the integrated design methodology, we can make more easily software systems based on relational database. In the case study, proposal integrated design methodology applied for a visa issuing system.

Exploring Elementary Teachers' Difficulties on Teaching Science by Analyzing Questions in an Autonomous Online Teacher Community : Focusing on Physics Questions in Indischool (자생적 온라인 교사 공동체의 질문분석을 통한 초등교사의 과학 교수 관련 어려움 탐색 -인디스쿨의 물리 관련 질문 게시글을 중심으로-)

  • Kim, Yunhwa;Yoo, Junehee
    • Journal of The Korean Association For Science Education
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    • v.39 no.1
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    • pp.73-88
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    • 2019
  • The purpose of this study is to explore elementary teachers' difficulties on teaching science by analyzing questions that have been posted for a long time in an autonomous online teacher community named Indischool. For this purpose, 409 question postings(the 2007 and 2009 revised curriculum, third to sixth grade) were analyzed using the framework for analyzing questions about elementary teachers' science teaching(modified from Alake-Tuenter et al., 2013). The study revealed that there were more science-SMK questions than science-PCK questions, and most of the questions were 'about lenses' and 'in 2014 and 2015, when the curriculum was changing from the 2007 to the 2009 revised curriculum'. The long-standing difficulties in science-SMK were 'an application of facts and concepts in lenses' and 'an unexpected experimental error in electricity'. In particular, there are the principle of transparent cup-shaped objects acting as lenses, the process of image formation by convex lenses, experimental errors of 'compass movement due to current flow change' and experimental errors 'serial connection of bulbs'. The long-standing difficulties in science-PCK were 'understanding and response to context' and 'understanding and response to aims mentioned in standard document' and these are not related to physical units but to others. In particular, there are request class materials, activity ideas at the end of the semester and understanding the national curriculum guidelines. These teachers' difficulties should be reflected in the science teaching support system like a teacher's guide compilation, teacher's training curriculum development, etc.

A Study on the Improvement of UAV based 3D Point Cloud Spatial Object Location Accuracy using Road Information (도로정보를 활용한 UAV 기반 3D 포인트 클라우드 공간객체의 위치정확도 향상 방안)

  • Lee, Jaehee;Kang, Jihun;Lee, Sewon
    • Korean Journal of Remote Sensing
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    • v.35 no.5_1
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    • pp.705-714
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    • 2019
  • Precision positioning is necessary for various use of high-resolution UAV images. Basically, GCP is used for this purpose, but in case of emergency situations or difficulty in selecting GCPs, the data shall be obtained without GCPs. This study proposed a method of improving positional accuracy for x, y coordinate of UAV based 3 dimensional point cloud data generated without GCPs. Road vector file by the public data (Open Data Portal) was used as reference data for improving location accuracy. The geometric correction of the 2 dimensional ortho-mosaic image was first performed and the transform matrix produced in this process was adopted to apply to the 3 dimensional point cloud data. The straight distance difference of 34.54 m before the correction was reduced to 1.21 m after the correction. By confirming that it is possible to improve the location accuracy of UAV images acquired without GCPs, it is expected to expand the scope of use of 3 dimensional spatial objects generated from point cloud by enabling connection and compatibility with other spatial information data.

Performance Comparison of TCP and SCTP in Wired and Wireless Internet Environment (유무선 인터넷 환경에서 TCP와 SCTP의 성능 비교)

  • Sasikala, Sasikala;Seo, Tae-Jung;Lee, Yong-Jin
    • 대한공업교육학회지
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    • v.33 no.2
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    • pp.287-299
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    • 2008
  • HTTP is one of the most widely used protocols of the WWW. Currently it uses TCP as the transport layer protocol to provide reliability. The HTTP uses separate TCP connection for each file request and adds unnecessary head-of-line blocking overhead for the file retrieval. The web application is short sized and affected by the increased handover latency of TCP in wireless environment. SCTP has attractive features such as multi-streaming and multi-homing. SCTP's multi-streaming and multi-homing avoid head-of-line blocking problem of TCP and reduce handover latency of TCP in wired and wireless environment. Mean response time is the important measure in most web application. In this paper, we present the comparison of mean response time between HTTP over SCTP with that of HTTP over TCP in wired and wireless environments using NS-2 simulator. We measured mean response time for varying packet loss rate, bandwidth, RTT, and the number of web objects in wired environment and mean response time and packet loss rate for varying moving speed and region size in wireless environment. Our experimental result shows that SCTP reduces the mean response time of TCP based web traffic.