• Title/Summary/Keyword: 선택적 공유

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An Efficient Query-based XML Access Control Enforcement Mechanism (효율적인 질의 기반 XML 접근제어 수행 메커니즘)

  • Byun, Chang-Woo;Park, Seog
    • Journal of KIISE:Databases
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    • v.34 no.1
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    • pp.1-17
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    • 2007
  • As XML is becoming a de facto standard for distribution and sharing of information, the need for an efficient yet secure access of XML data has become very important. To enforce the fine-level granularity requirement, authorization models for regulating access to XML documents use XPath which is a standard for specifying parts of XML data and a suitable language for both query processing. An access control environment for XML documents and some techniques to deal with authorization priorities and conflict resolution issues are proposed. Despite this, relatively little work has been done to enforce access controls particularly for XML databases in the case of query access. Developing an efficient mechanism for XML databases to control query-based access is therefore the central theme of this paper. This work is a proposal for an efficient yet secure XML access control system. The basic idea utilized is that a user query interaction with only necessary access control rules is modified to an alternative form which is guaranteed to have no access violations using tree-aware metadata of XML schemes and set operators supported by XPath 2.0. The scheme can be applied to any XML database management system and has several advantages over other suggested schemes. These include implementation easiness, small execution time overhead, fine-grained controls, and safe and correct query modification. The experimental results clearly demonstrate the efficiency of the approach.

Alternative Evaluation Model for Tower Crane Operation Plan in Modular Construction - Focusing on Modular Unit Installation and Finishing works - (모듈러 건축 타워크레인 운용 계획의 대안 평가 모델 - 유닛 설치 및 마감공사를 중심으로 -)

  • Kim, Joo Ho;Park, Moonseo;Lee, Hyun-Soo;Hyun, Hosang
    • Korean Journal of Construction Engineering and Management
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    • v.19 no.2
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    • pp.50-60
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    • 2018
  • Recently, modular construction method has been widely applied to projects with repetitive processes including dormitory, the residential facility, and the hotel construction due to reduced labor input and shortened construction schedule. Generally, about 40% of total on-site construction cost excluding unit installation cost, is put on exterior finishing work, and thus management of finishing work is deemed important in maintaining the targeted schedule and cost. Since limited equipment is shared so that subsequent activities are not affected while carrying out on-site installation and finishing work, lifting plan becomes more important for modular projects with greater portion of finishing work load. In this regard, tower crane operation plan may take the form of a single cycle or multiple cycles in which equipment efficiency can be affected. However, difficulties exist in evaluating alternatives to tower crane operation plans supporting unit installation and finishing work. Therefore, this study aims to evaluate the alternative of tower crane operation method according to the cyclic period setting in modular building site to determine the effect on T/C uptime and process by parameterizing lifting time for unit and exterior finishing material, lift cycle for unit and exterior finishing material and time required for finishing work. Accordingly, this study develops a simulation model that can increase the tower crane efficiency by controlling the work speed. An academic contribution of this study is to suggest a resource leveling method applying the concept of lifting cycle, and further is expected to be managerially used as a basis for an alternative evaluation of equipment plan.

A Study on Development of Network Management Systems base on Component (컴포넌트 기반의 망관리 시스템 개발에 관한 연구)

  • Kim, Haeng-Kon;Kim, Ji-Young
    • The KIPS Transactions:PartD
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    • v.11D no.4
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    • pp.937-950
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    • 2004
  • With growing population of internet and web applications, distributed environment is considered to be the standard architecture of application. A network management systems(NMS) is necessary to control and monitor the complex network resources for providing and sharing the heft quality service. We recognize the NMS as a standard infrastructure for supporting efficient networking and a separate commercial applications. We believe every resource including software, hardware and environment for the network management should be separated from special protocols, vendors and applications. Therefore, We need a standard network management system that is efficient and consistent because of the heterogeous network features. In regards to software development, software reuse through assembling and extending the reusable elements such as patterns and components assures to realize the best productivity and quality The component based development(CBD) methodology that can assemble black box though well defined interfaces makes it possible to develop easer and quicker applications and is proved as the best software development solution involved in construction, selection and assembly of components. In this thesis, we describe the architecture for the network management and identify, define and design the components through analysis and design in the network management domain and Identified components mapped to the component architecture. We also specify the component development and design and implement the component for developing the network management. Implemented components apply to the component repository system that register, retrieve and understand the components. We analyze, design and implement the entire network management system based on configuration, connection, performance and fault management through the pre-developed components.

Transmitting Devices Selection Based on Viewpoint Popularity for Wireless Free-Viewpoint Video Streaming (무선 자유시점 비디오 스트리밍에서 인기도 기반 전송 기기 선택 기법)

  • Koo, Jae-Woo;Cho, Young-Jong;Kang, Kyungran
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.41 no.5
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    • pp.546-554
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    • 2016
  • Free-viewpoint video (FVV) is a synthesization technology that generates a virtual viewpoint video using multiple videos recorded via wireless devices at heterogeneous locations. In order to introduce a new service that grafts the FVV onto the real-time streaming service using wireless devices, we need to overcome several constraints. Two main factors of those constraints are the limited wireless capacity that are shared fairly by multiple devices, and the transmission time constraint with which live streaming services have to comply. Therefore, for optimal quality of entire videos, a set of transmitting devices should be effectively selected depending on the condition of wireless channel and the required video popularity of specific viewpoint requested from users. For optimal selection, this study proposes a heuristic algorithm that takes into account the aforementioned factors from possible wireless transmission error behaviors and the requested viewpoint popularity. Through analysis and simulation, we show that with this algorithm, quality of most popular viewpoint videos is guaranteed. Furthermore, performance comparison against the existing scheme which is based only on the location of recording devices is made.

Pedagogical Content Knowledge of Socio-Scientific Issues: Characterizing Teachers' Experiences (과학 기술 관련 사회쟁점 교육에 대한 과학 교사들의 SSI-PCK 사례연구)

  • Chung, Haengnam;Ryu, Suna
    • Journal of The Korean Association For Science Education
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    • v.37 no.4
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    • pp.679-691
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    • 2017
  • Despite the growing importance of socio-scientific issues (SSI), little work has focused on teachers' pedagogical knowledge, and few studies have examined how in-service teachers use and apply SSI-related instructional methods and strategies. Consequently, the purpose of this study was to explore how science teachers with lots of SSI teaching experience determined teaching orientation, selected and revised instructional methods, and devised assessments in science classroom. We used a case study approach aimed at a deep description of these teachers' teaching experiences and employed semi-structured and in-depth interviews with five experienced teachers. Our findings indicate that teaching orientation and learning objectives seemed to influence the selection and modification of instructional strategies and methods. In addition, students' learning experiences or classroom environment were considered and modified in light of achieving these learning objectives. However, introducing SSI into the classroom assessment is not seriously considered by most teachers. This study can provide teachers with useful information when designing and developing SSI classes, taking into account various aspects of the PCK such as learning orientation, instructional methods, learner expereince and curriculum standards.

Multi-Hop Vehicular Cloud Construction and Resource Allocation in VANETs (VANET 망에서 다중 홉 클라우드 형성 및 리소스 할당)

  • Choi, Hyunseok;Nam, Youngju;Lee, Euisin
    • KIPS Transactions on Computer and Communication Systems
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    • v.8 no.11
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    • pp.263-270
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    • 2019
  • Vehicular cloud computing is a new emerging technology that can provide drivers with cloud services to enable various vehicular applications. A vehicular cloud is defined as a set of vehicles that share their own resources. Vehicles should collaborate with each other to construct vehicular clouds through vehicle-to-vehicle communications. Since collaborating vehicles to construct the vehicular cloud have different speeds, directions and locations respectively, the vehicular cloud is constructed in multi-hop communication range. Due to intermittent wireless connectivity and low density of vehicles with the limited resources, the construction of vehicular cloud with multi-hop communications has become challenging in vehicular environments in terms of the service success ratio, the service delay, and the transmitted packet number. Thus, we propose a multi-hop vehicular cloud construction protocol that increases the service success ratio and decreases the service delay and the transmitted packet number. The proposed protocol uses a connection time-based intermediate vehicle selection scheme to reduce the cloud failure probability of multi-hop vehicular cloud. Simulation results conducted in various environments verify that the proposed protocol achieves better performance than the existing protocol.

Multi-day Trip Planning System with Collaborative Recommendation (협업적 추천 기반의 여행 계획 시스템)

  • Aprilia, Priska;Oh, Kyeong-Jin;Hong, Myung-Duk;Ga, Myeong-Hyeon;Jo, Geun-Sik
    • Journal of Intelligence and Information Systems
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    • v.22 no.1
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    • pp.159-185
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    • 2016
  • Planning a multi-day trip is a complex, yet time-consuming task. It usually starts with selecting a list of points of interest (POIs) worth visiting and then arranging them into an itinerary, taking into consideration various constraints and preferences. When choosing POIs to visit, one might ask friends to suggest them, search for information on the Web, or seek advice from travel agents; however, those options have their limitations. First, the knowledge of friends is limited to the places they have visited. Second, the tourism information on the internet may be vast, but at the same time, might cause one to invest a lot of time reading and filtering the information. Lastly, travel agents might be biased towards providers of certain travel products when suggesting itineraries. In recent years, many researchers have tried to deal with the huge amount of tourism information available on the internet. They explored the wisdom of the crowd through overwhelming images shared by people on social media sites. Furthermore, trip planning problems are usually formulated as 'Tourist Trip Design Problems', and are solved using various search algorithms with heuristics. Various recommendation systems with various techniques have been set up to cope with the overwhelming tourism information available on the internet. Prediction models of recommendation systems are typically built using a large dataset. However, sometimes such a dataset is not always available. For other models, especially those that require input from people, human computation has emerged as a powerful and inexpensive approach. This study proposes CYTRIP (Crowdsource Your TRIP), a multi-day trip itinerary planning system that draws on the collective intelligence of contributors in recommending POIs. In order to enable the crowd to collaboratively recommend POIs to users, CYTRIP provides a shared workspace. In the shared workspace, the crowd can recommend as many POIs to as many requesters as they can, and they can also vote on the POIs recommended by other people when they find them interesting. In CYTRIP, anyone can make a contribution by recommending POIs to requesters based on requesters' specified preferences. CYTRIP takes input on the recommended POIs to build a multi-day trip itinerary taking into account the user's preferences, the various time constraints, and the locations. The input then becomes a multi-day trip planning problem that is formulated in Planning Domain Definition Language 3 (PDDL3). A sequence of actions formulated in a domain file is used to achieve the goals in the planning problem, which are the recommended POIs to be visited. The multi-day trip planning problem is a highly constrained problem. Sometimes, it is not feasible to visit all the recommended POIs with the limited resources available, such as the time the user can spend. In order to cope with an unachievable goal that can result in no solution for the other goals, CYTRIP selects a set of feasible POIs prior to the planning process. The planning problem is created for the selected POIs and fed into the planner. The solution returned by the planner is then parsed into a multi-day trip itinerary and displayed to the user on a map. The proposed system is implemented as a web-based application built using PHP on a CodeIgniter Web Framework. In order to evaluate the proposed system, an online experiment was conducted. From the online experiment, results show that with the help of the contributors, CYTRIP can plan and generate a multi-day trip itinerary that is tailored to the users' preferences and bound by their constraints, such as location or time constraints. The contributors also find that CYTRIP is a useful tool for collecting POIs from the crowd and planning a multi-day trip.

Verification the Systems Thinking Factor Structure and Comparison of Systems Thinking Based on Preferred Subjects about Elementary School Students' (초등학생의 시스템 사고 요인 구조 검증과 선호 과목에 따른 시스템 사고 비교)

  • Lee, Hyonyong;Jeon, Jaedon;Lee, Hyundong
    • Journal of The Korean Association For Science Education
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    • v.39 no.2
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    • pp.161-171
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    • 2019
  • The purposes of this study are: 1) to verify the systems thinking factor structure of elementary school students and 2) to compare systems thinking according to their preferred subjects in order to get implications for following research. For the study, pre-tests analyze data from 732 elementary school students using the STMI (Systems Thinking Measuring Instrument) developed by Lee et al. (2013). And exploratory factor analysis was conducted to identify the factor structure of the students. Based on the results of the pre-test, the expert group council revised the STMI so that elementary school students could respond to the 5-factor structure that STMI intended. In the post-test, 503 data were analyzed by modified STMI and exploratory factor analysis was performed. The results of the study are as follows: First, in the pre-test, elementary school students responded to the STMI with a test paper consisting of two factors (personal internal factors and personal external factors). The total reliability of the instrument was .932 and the reliability of each factor was analyzed as .857 and .894. Second, for modified STMI, elementary school students responded a 4-factor instrument. Team learning, Shared Vision, and Personal Mastery were derived independent factors, and mental model and systems analysis were derived 1-factor. The total reliability of the instrument was .886 and the reliability of each factor was analyzed as .686 to .864. Finally, a comparison of systems thinking according to preferred subjects showed a significant difference between students who selected science (engineering) group and art (music and physical education). In conclusion, it was confirmed that statistically meaningful results could be obtained using STMI modified by term and sentence structure appropriate for elementary school students, and it is a necessary to study the relation of systems thinking with various student variables such as the preferred subjects.

A single case study using Contextual Support Model based music therapy intervention for a terminal pediatric patient (말기질환 아동을 위한 환경적 지지모델(The Contextual Support Model of Music Therapy)에 근거한 음악치료사례연구)

  • Jun, Mi Hye
    • Journal of Music and Human Behavior
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    • v.2 no.2
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    • pp.15-31
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    • 2005
  • Terminal pediatric patient include congenital metabolic abnormalities, chromosome aberrations, congenital anomalies, neuromuscular diseases and other incurable conditions as well as malignant tumors. One third of these diseases are cancers, and two thirds of cancers are lymphadenoma and leukemia. Terminal pediatric patient may feel fear, anger and frustration against treatment process in hospitals, lose control of themselves and stay in helplessness due to restrictions within controlled hospital environment. This study examined the relationship between hospitalized childrens behavior and music using Contextual Support Model of Music Therapya theory stating therapeutic music environments possess three elements of Structure, Autonomy support and Involvement, and increase childrens active engagement. Focused on these three therapeutic elements, this study analyzed music therapy cases of terminally ill children to examine the relationship between childrens behavior and music as environmental supportive medium in the environment. This study is on a single case case subject, a 10-year-old girl with acute lymphocytic leukemia. Nine sessions of music therapy activities were conducted and analyzed using qualitative method. Focusing on three therapeutic elements of Contextual Support Model, analysis of sessions was made on the basis of activities specifically designed for this study. Main music therapy activities included singing while playing musical instruments, singing while listening to music through CD player, making up songs, and searching for song lines. The findings of this study are as follows: a) in terms of Structure, music therapy suggested a direction for effective musical activities for terminally ill children by providing environments where child can sing, play musical instruments and make up songs; b) in terms of Autonomy support, music therapy encouraged childs voluntary participation by giving her chances to make choice while singing or playing musical instruments; c) in terms of Involvement, child could gain positive approval of the therapist and conduct musical activities in cooperation with the therapist. Music therapy serves as supportive medium in the environment, develops spontaneity and self-reliance in emotionally depressed children, and promotes voluntary attitudes in the restricted hospital environment. Based on the positive effects of music therapy, more studies need to be conducted with an approach to more various terminal pediatric patients.

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A Study on the Necessity of Making Online Marketplace for the Korean Animation Industry (국내 애니메이션 산업의 온라인 마켓플레이스 구축 필요성 연구)

  • Han, Sang-Gyun
    • Cartoon and Animation Studies
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    • s.24
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    • pp.223-246
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    • 2011
  • Today, cultural content industry could be defined to service business rather than manufacturing business because of its own trait. Also, it has the realistic restriction that it can't hold the dominant position in the market competition when it can't provide consumers satisfaction regardless of its quality or degree of completion. In other word, it can only expect great success when the business plan and the activities get the perfect balance with its best quality and perfect of completion. As the result, it emphasizes the importance of business competition in the global market. In briefly, there is no doubt that the creativeness of content is very important in the cultural content industry but in the future, making system to maintain the distribution process and share the profits fairly will be taken more important role. Especially, animation genre has the feature, which compares to other genres, such as film or TV drama, would be free from cultural barriers, and it is a great advantage. So to speak, animation can get little influence from cultural discount. However, Korean animation can't use the advantage properly for the foreign distribution because of its poor infrastructure and short of professional human resources. For those reasons, it has been needed to set up the realistic and specific action plan to overcome the situation. Therefore, considering those needs and the situations of Korean animation facing, making B2B online marketplace could be a great solution. The online marketplace stands for taking more efficient and broad distribution channel instead of the passive way, which we have now. If we have the B2B online marketplace, we can share all the information about the Korean animation with the potential customers whom live outside of Korea at real time. It also could be use to the windows of multiple distribution, which can make additional profits and activate the optional markets for the Korean animation. Through the method, Korean animation would be expected to get the higher international competitiveness, and it would be developed in quality and quantity of the business. Finally, it would be a great chance to Korean animation, which can get the unique brand power by improving the backward distribution circumstances.