• Title/Summary/Keyword: Technical Issue

Search Result 535, Processing Time 0.02 seconds

A Study on the Access Control Mechanism for Supporting Multiple Classes of Service in the IMT-2000 (IMT-2000에서 다양한 서비스를 제공하기 위한 채널 액세스 방식 연구)

  • Lee, Kwang-Je;Chung, Jin-Wook;Ryu, Hee-Sahm;Won, Young-Jin
    • Journal of the Institute of Electronics Engineers of Korea TE
    • /
    • v.37 no.1
    • /
    • pp.42-49
    • /
    • 2000
  • A major technical issue related to supporting multiple classes of service in IMT-2000 is the efficient management of limited channel. The selection of channel access control technique has a significant impact on user QOS, system capacity, and is therefore an important design parameter. In this paper, to achieve the service at resonable QOS level, while utilizing channel resource effectively, some improved methods are proposed by analyzing of the recently released methods.

  • PDF

Technical and Strategic Approach for the Control of Cyanobacterial Bloom in Fresh Waters (담수수계에서 남조류 증식억제의 기술적, 전략적 접근)

  • Lee, Chang Soo;Ahn, Chi-Yong;La, Hyun-Joon;Lee, Sanghyup;Oh, Hee-Mock
    • Korean Journal of Environmental Biology
    • /
    • v.31 no.4
    • /
    • pp.233-242
    • /
    • 2013
  • Cyanobacteria (blue-green algae) are not only the first oxygenic organisms on earth but also the foremost primary producers in aquatic environment. Massive growth of cyanobacteria, in eutrophic waters, usually changes the water colour to green and is called as algal (cyanobacterial) bloom or green tide. Cyanobacterial blooms are a result of high levels of primary production by certain species such as Microcystis sp., Anabaena sp., Oscillatoria sp., Aphanizomenon sp. and Phormidium sp. These cyanobacterial species can produce hepatotoxins or neurotoxins as well as malodorous compounds like geosmin and 2-methylisoborneol (MIB). In order to solve the nationwide problem of hazardous cyanobacterial blooms in Korea, the following technically and strategically sound approaches need to be developed. 1) As a long-term strategy, reduction of the nutrients such as phosphorus and nitrogen in our water bodies to below permitted levels. 2) As a short term strategy, field application of combination of already established bloom remediation techniques. 3) Development of emerging convergence technologies based on information and communication technology (ICT), environmental technology (ET) and biotechnology (BT). 4) Finally, strengthening education and creating awareness among students, public and industry for effective reduction of pollution discharge. Considering their ecological roles, a complete elimination of cyanobacteria is not desirable. Hence a holistic approach mentioned above in combination to addressing the issue from a social perspective with cooperation from public, government, industry, academic and research institutions is more pragmatic and desirable management strategy.

Mechanism of China's Internet Regulation (중국의 인터넷 통제 메커니즘)

  • Kim, Jin Yong
    • Informatization Policy
    • /
    • v.20 no.1
    • /
    • pp.61-84
    • /
    • 2013
  • This article examines how the Chinese government blocks the inflow of undesirable information, focusing on the technical aspect of the control mechanism. Unlike Cuba and North Korea, which regulate the whole Internet, China uses both state-of-the-art technological supervision and labor-intensive physical control due to economic reasons in order to prepare for actors who can threaten the Communist party. The Chinese government will not overlook the inflow of information which can be the link between demonstrations and democratization. This is because stronger protests utilizing information technology will trigger the Chinese government's flexible control based on large scale violation and technology. In this article, we first review the concept of universal internet control involved in internet regulation in nations, and then focus on China's internet censorship and its regulatory control from the '90s to the present. Finally, we analyze how the Chinese government actively controls the internet access by utilizing the relationship dynamics between the central and local governments, depending on protest issue. This thesis will assume that it is difficult for China to become democratized due to its information interception, and search how the government manages the internet.

  • PDF

On the Balanced Blending of Formally Structured and Simplified Approaches for Utilizing Judgments of Experts in the Assessment of Uncertain Issues

  • Ahn Kwang-Il;Yang Joon-Eon;Ha Jae-Joo
    • Nuclear Engineering and Technology
    • /
    • v.35 no.4
    • /
    • pp.318-335
    • /
    • 2003
  • Expert judgment is frequently employed in the search for the solution to various engineering and decision-making problems where relevant data is not sufficient or where there is little consensus as to the correct models to apply. When expert judgments are required to solve the underlying problem, our main concern is how to formally derive their technical expertise and their personal degree of familiarity about the related questions. Formal methods for gathering judgments from experts and assessing the effects of the judgments on the results of the analysis have been developed in a variety of ways. The most important interest of such methods is to establish the robustness of an expert's knowledge upon which the elicitation of judgments is made and an effective trace of the elicitation process as possible as one can. While the resultant expert judgments can remain to a large extent substantiated with formal elicitation methods, their applicability however is often limited due to restriction of available resources (e.g., time, budget, and number of qualified experts, etc) as well as a scope of the analysis. For this reason, many engineering and decision-making problems have not always performed with a formal/structured pattern, but rather relied on a pertinent transition of the formal process to the simplified approach. The purpose of this paper is (a) to address some insights into the balanced use of formally structured and simplified approaches for the explicit use of expert judgments under resource constraints and (b) to discuss related decision-theoretic issues.

Enhancement of UAV-based Spatial Positioning Using the Triangular Center Method with Multiple GPS

  • Joo, Yongjin;Ahn, Yushin
    • Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
    • /
    • v.37 no.5
    • /
    • pp.379-388
    • /
    • 2019
  • Recently, a technique for acquiring spatial information data using UAV (Unmanned Aerial Vehicle) has been greatly developed. It is a very crucial issue of the GIS (Geographic Information System) mapping system that passes way point in the unmanned airframe and finally measures the accurate image and stable localization to the desired destination. Though positioning using DGPS (Differential Global Navigation System) or RTK-GPS (Real Time Kinematic-GPS) guarantee highly accurate, they are more expensive than the construction of a single positioning system using a single GPS. In the case of a low-priced single GPS system, the stability of the positioning data deteriorates. Therefore, it is necessary to supplement the uncertainty of the absolute position data of the UAV and to improve the accuracy of the current position data economically in the operating state of the UAV. The aim of this study was to present an algorithm enhancing the stability of position data in a single GPS mode of UAV with multiple GPS. First, the arrangement of multiple GPS receivers through the center of gravity of the UAV were examined. Next, MD (Mahalanobis Distance) is applied to detect instantaneous errors of GPS data in advance and eliminate outliers to increase the accuracy of previously collected multiple GPS data. Processing procedure for multiple GPS reception data by applying the center of the triangular method were presented to improve the position accuracy. Second, UAV navigation systems integrated multiple GPS through configuration of the UAV specifications were implemented. Using the unmanned airframe equipped with multiple GPS receivers, GPS data is measured with the TCM (Triangular Center Method). In addition, UAV equipped with multiple GPS were operated in study area and locational accuracy of multiple GPS of UAV with VRS (Virtual Reference Station) GNSS surveying were compared. The result showed that the error factors are compensated, and the error range are reduced, resulting in the reliability of the corrected value. In conclusion, the result in this paper is expected to realize high-precision position estimation at low cost in UAV using multiple low-cost GPS receivers.

Experiences with Guiding Students with Mental Health Support Needs among Middle and High School Teachers (중·고등학교 교사의 정신건강 관심군 학생 지도 경험)

  • Park, Ok Nam
    • Journal of the Korean Society of School Health
    • /
    • v.30 no.3
    • /
    • pp.211-223
    • /
    • 2017
  • Purpose: The purpose of this study is to clarify the social stigma phenomenon in teachers' perceptions and attitudes toward students who are classified as mental health support needs students in middle and high schools. Methods: Qualitative research was conducted through in-depth interviews and observations of 17 teachers and 2 consultants from 2 middle and high schools in Green City, which were evaluated as successful among the six pilot project schools designated by the Ministry of Education in 2013. The study's analysis is based on Hatch's hermeneutical method. Common categories were developed from the interviews and observations. Then, inferences were made per category and given importance to draw conclusions and lessons. Results: Teachers had a strong stigma in their perceptions of and attitudes to special needs students. Their perception was that those students are bound to go wrong due to family problems, even some having difficulty breathing, and that it's beyond their limit to help them. In addition, their attitudes included stereotypes, favoritism, punishment, and referral to experts. As a result, teachers did not expect those students would be cured or change and showed passive attitudes while shifting the responsibility to families and experts. Conclusion: This study is meaningful in that it showed the limitations of the role of teachers regarding mental health support needs students from the perspective of the teachers themselves. Today, when students' mental health problems are emerging as a serious issue, it is necessary to provide support to improve teacher's awareness and capabilities regarding adolescent mental health problems. In addition, we suggest the current selective policy that sorts out special needs students and provides care for them to evolve into a universal policy that improves public awareness and focus on prevention.

Conditions for Integrated Public Welfare Delivery System: Case Studies in Britain (통합적 공공 복지전달체계를 위한 조건: 영국 사례 연구)

  • Kim, Bo-Yung
    • 한국사회정책
    • /
    • v.25 no.2
    • /
    • pp.403-428
    • /
    • 2018
  • There has been constant attempts for integration of public welfare delivery system which lead to integrated case management, then this become more significant issue regarding 'community care' recently in Korea. However, most of them was limited to fractional organization rearrangement or more use of private resources rather than realising user-centred approach. Therefore, in this research, we would like to do a couple of case studies in Britain which has rich experience of reforms for integrated approaches between health and social services and Troubled Family programme resembles the integrated case management in Korea by visiting a London Borough and a local council respectively. In conclusion, we found three conditions are required to establish successful integrated delivery system: elimination of institutional barriers relating to workforce, organization, and finance; shared objectives and partnership among the professional groups and agencies; and information sharing system with technical support regarding individual cases.

Appraising the Performance of Construction Projects during Implementation in Kenya, 1963-2018: A Literature Review Perspective

  • Ong'ondo, Cyrus Babu;Gwaya, Abednego Oswald;Masu, Sylvester
    • Journal of Construction Engineering and Project Management
    • /
    • v.9 no.2
    • /
    • pp.1-24
    • /
    • 2019
  • Poor project performance has been noted as the bane in the construction industry globally. This paper sought to investigate, by way of literature, the performance patterns of construction projects in Kenya since independence (1963-2018). This was informed by reports of undesirable project performance in the industry. This descriptive study used available studies previously done in this subject area. In sum, literature is replete with evidence on a myriad of challenges facing the execution of projects. The study established that generally, the project performance is poor and has assumed a chronic trajectory spanning over five decades. On average, the findings reveal that 35-60% of projects initiated in Kenya face cost overruns while time overrun is most severe with 35-73% projects overrunning their schedule. In addition, the findings problematize the issue of plurality of performance measurement regimes in the construction industry. Here, it was observed that no singular construct exists to objectively measure the various facets that constitute the 'health' of a project. This paper has contributed to the body of knowledge by examining the performance patterns in Kenya for over fifty years while at the same time identifying the bottlenecks inherent in projects execution. Importantly, the conceptual performance efficiency framework derived in the current study presents a paradigm shift in the monitoring and evaluation of projects. To this end, an in-depth analysis is recommended on the interaction of efficiency enablers in the buildup of performance efficiency index (PEI). Similarly, a further inquiry is recommended on the integration and impact of the proposed framework in the management of projects.

Convergence of Art and Technology: Based on E.A.T.'s Periodic Background and Characteristics of Works (예술과 기술의 융합: E.A.T.의 시대적 배경과 작품 특성을 중심으로)

  • Zhang, Cheng;Um, Myoung-Yong
    • The Journal of the Korea Contents Association
    • /
    • v.19 no.4
    • /
    • pp.477-489
    • /
    • 2019
  • Recently, interdisciplinary studies have been receiving attention. Interdisciplinary research, especially in arts and technology, is a very interesting issue. E.A.T. was founded in New York in 1966 by artists and engineers. Based on the E.A.T. case, this study analyzed the period background in which art and technology could be converged, and the characteristics of E.A.T. works. The analysis results of the period background revealed that five factors influenced the organization and development of E.A.T.. Economic factors, artistic factors, technical factors, educational factors, and sponsored cultural factors influenced the convergence of art and technology. E.A.T. works collaborated by artists and engineers generally had three characteristics. Convergence across various fields, multi-sensitivity utilizing different senses, and interaction between the environment and humans appeared in E.A.T. works. This study provides meaningful implications for both artists and engineers who wish to overcome the limitations of artistic expression and develop new technology.

Mixed Reality Extension System Using Beam Projectors : Beyond the Sight (빔 프로젝터를 이용한 혼합현실 확장 시스템 : Beyond the Sight)

  • Kim, Jongyong;Song, J.H;Park, J.H.;Nam, J.;Yoon, Seung-Hyun;Park, Sanghun
    • Journal of the Korea Computer Graphics Society
    • /
    • v.25 no.3
    • /
    • pp.65-73
    • /
    • 2019
  • Recently commercial mixed-reality devices have be launched and a variety of mixed-reality content has produced, but narrow field of view, which appear to be hardware technical limitations, are mentioned as an important issue for hindering immersion and limiting the scope of use. We propose a new innovative system that cooperate multiple beam projectors and a number of mixed reality devices. Using this technology, users can maximize immersion and minimize frustration of narrow viewing angles through 3D object rendering on background of large 2D screens. This system, named BtS (Beyond the Sight), is implemented on a client-server basis and includes the ability to calibrate between devices, share spatial coordinate systems, and synchronize real-time renderings as core modules. In this paper, each configuration module is described in detail and the possibility of its performance and application is shown through the introduction of mixed reality content case created using BtS system.