• Title/Summary/Keyword: Free-space method

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A Study on the Efficient Establishment and Operation of a Gallery in Public Libraries (공공도서관의 효율적인 갤러리 설치·운영 방안 연구)

  • Young-Seok Kim
    • Journal of the Korean Society for Library and Information Science
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    • v.57 no.4
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    • pp.263-287
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    • 2023
  • This study aims to find an efficient establishment and operation of a gallery in public libraries. A literature review, field case study, and interview method were used. 15 public library galleries in 5 regions in Korea and 11 public library galleries in 11 cities in 3 countries were examined. 22 people were interviewed and 21 (95.5%) of them claimed that a gallery needs to be operated in a public library. The result of the analysis proposes the followings for an efficient establishment and operation of a gallery in public libraries: firstly, employing an art gallery curator according to the library's situation. Secondly, establishing a gallery of at least 55m2 in size. Thirdly, allocating an appropriate budget. Fourthly, if possible, gallery rental requests are reviewed by external experts and a gallery needs to be rented out to the public free of charge. Fifthly, having an operating manual or a regulation. Sixthly, a gallery should be operated directly by the library.

Study on the Positioning Method using BLE for Location based AIoT Service (위치 기반 지능형 사물인터넷 서비스를 위한 BLE 측위 방법에 관한 연구)

  • Ho-Deok Jang
    • The Journal of Korea Institute of Information, Electronics, and Communication Technology
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    • v.17 no.1
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    • pp.25-30
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    • 2024
  • Smart City, a key application area of the AIoT (Artificial Intelligence of Things), provides various services in safety, security, and healthcare sectors through location tracking and location-based services. an IPS (Indoor Positioning System) is required to implement location-based services, and wireless communication technologies such as WiFi, UWB (Ultra-wideband), and BLE (Bluetooth Low Energy) are being applied. BLE, which enables data transmission and reception with low power consumption, can be applied to various IoT devices such as sensors and beacons at a low cost, making it one of the most suitable wireless communication technologies for indoor positioning. BLE utilizes the RSSI (Received Signal Strength Indicator) to estimate the distance, but due to the influence of multipath fading, which causes variations in signal strength, it results in an error of several meters. In this paper, we conducted research on a path loss model that can be applied to BLE IPS for proximity services, and confirmed that optimizing the free space propagation loss coefficient can reduce the distance error between the Tx and Rx devices.

The Treatment for The Intractable Epidural Abscess Using Tensor Fascia Lata Graft and Anterolateral Thigh Free Flap (대퇴근막 이식과 전외측 대퇴 유리 피판을 이용한 난치성 경막 외 농양의 치료)

  • Park, Byung-Chan;Ryu, Min-Hee;Kim, Tae-Gon;Lee, Jun-Ho
    • Archives of Reconstructive Microsurgery
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    • v.18 no.1
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    • pp.23-26
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    • 2009
  • Purpose: Artificial dura maters are commonly used in cranioplasty, but sometimes they can result in serious postoperative infection. Once complications such as epidural abscess or chronic draining ulcer arise, they are very difficult to treat. In this case, reclosure of dura defect using artificial dura mater may give rise to recurrence of infection. We experienced a case of intractable epidural abscess caused by use of artificial dura. To avoid repeated infection, we decided to use autologous tissue for the coverage of dura and soft tissue defect. Therefore, autologous tensor fascia lata graft and anterolateral thigh free flap were harvested at the same donor site incision to cover composite defect on the scalp and dura mater. Methods: A 13 year old male patient, who underwent the decompression cranioplasty and duroplasty, suffered from the intractable infection lesion. Twice, the epidural abscess was removed, both times the infection recurred. And eventually dura mater was exposed through the infected open wound. Nine months after dura exposed, infected aritificial dura mater was removed and extensive debridement was performed. Through a surgical incision on donor thigh, first, tensor fascia lata graft was harvested in process of the anterolateral thigh flap elevation. After the fascia lata graft was fixed over the dural defect, the anterolateral thigh flap was used to fill the dead space as well as the scalp defect. Results: Postoperatively, no recurrent infection and cerebrospinal fluid leakage are observed for a year. After the surgery, on the first and second day, venous congestion of the flap was observed, this problem was solved by thrombectomy and vein reanastomosis. And partial necrosis of flap occurred, but completely healed as conservative treatment for two weeks. Conclusion: Using the autologous tensor fascia lata graft and anterolateral thigh flap, we could obtain satisfactory results as treatment for the intractable infection lesion after duroplasty. Autologous tensor fascia lata in conjunction with anterolateral thigh flap is useful method for covering composite defect of scalp and dura mater.

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Verification on the Application of Monitoring for Frame Structures Using the VRS-RTK Method through the Free Vibration Test (자유 진동 실험을 통한 VRS-RTK 기법을 이용한 골조 구조물의 모니터링 적용성 검토)

  • Choi, Se-Woon;Park, Hyo-Seon;Kim, Bub-Ryur;Lee, Hong-Min;Kim, You-Sok
    • Journal of the Korea institute for structural maintenance and inspection
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    • v.18 no.1
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    • pp.174-182
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    • 2014
  • To monitor the wind-induced responses of buildings, conventional real-time kinematic (RTK) methods based on two global positioning system (GPS) receivers (e.g., a reference and a rover) are widely applied. However, these methods can encounter problems such as difficulty in securing and maintaining a space for a reference station. With the recently developed virtual reference station (VRS)-RTK approach, the position of a structure can be measured using only a rover receiver. In this study, to evaluate the applicability of VRS-RTK methods in monitoring the lateral structural responses of frame structures, we performed free vibration tests on a one-story frame model (the first natural frequency of 1 Hz) and a three-story frame model (the first natural frequency of 0.85 Hz). To assess the reliability of the displacement and acceleration responses measured by the GPS, we performed a concurrent measurement using laser displacement sensors and an accelerometer. The accelerometer results were consistent with the GPS measurements in terms of the time history and frequency content. Furthermore, to derive an appropriate sampling rate for the continuous monitoring of buildings, the errors in the displacement responses were evaluated at different GPS sampling rates (5, 10, 20 Hz). The results indicate that as the sampling rate increased, the errors in the displacement responses decreased. In addition, in the three-story model, all modal components (first, second, and third modes) could be recorded at a sampling rate of 20 Hz.

A Study on the Visual Effects of Non-Photorealistic Rendering Animation focusing on 'Paperman,' a Short Animation (넌-포토리얼리스틱(Non-Photorealistic) 렌더링 애니메이션의 시각 효과 기법 - 단편 애니메이션 Paperman을 중심으로)

  • Park, Sung-Won
    • Cartoon and Animation Studies
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    • s.40
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    • pp.139-155
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    • 2015
  • Animation is completed in accordance with the original planning of visual direction in the process of post-production. Especially, a variety of visualization skills to meet the planning idea are directed in editing and compositing processes such as rendering and shading in the production of 3D animation. Therefore, the studies how to implement these visual effects have been conducted since the emergence of the animation. The rendering method which appears in the recent animations so often is the effect of 2D animation style although it is applied by 3D technique. 3D animation can be classified as two types including photo realistic and non-photo realistic renderings. The former is to render the images realistically while the latter is to highlight the formative effect with analogue style free from the realism of the photographs. Visual effect of 2D animation is non-realistic, that is, non-photo realistic rendering. The animations produced by this method have the depth of 3D animation expression in terms of space and animating, and can direct the viewer-friendly analogue style visuals, which are widely used as a post-production effect. Hence in this study, we selected a short animation, 'Paperman,' one of Disney's animations, produced by cartoon rendering method which belongs to the class of non-photo rendering technique in 3D graphics, as our subject. We analyzed their techniques and visual effects of the scenes expressed by cartoon rendering method so as to understand whether they meet the original direction idea with the composition work. In addition, we expect further developments of post-production methods, exceeding the limit of graphic expression in alignment with the trend that has become more various in the types and genres of non-photo rendering.

Effects of Fume silica on synthesis of New Austria Tunnel Method Resin for new material in space aviation (우주항공의 신소재를 위한 New Austria Tunnel Method 수지합성에 대한 Fume silica의 영향)

  • Kim, Kijun;Lee, Jooho;Park, Taesul;Lee, Joo-Youb
    • Journal of the Korean Applied Science and Technology
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    • v.31 no.4
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    • pp.595-601
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    • 2014
  • The microstructures of NATM were examined by SEM, FT-IR spectra, tensile properties, mole % of [NCO/OH], and particle size analyzer. Growing concerns in the environment-friendly industries have led to the development of solvent-free formulations that can be cured. We had synthesized NATM(New Austria Tunnel Method) resin having the ability to protect stainless steel against corrosion. Comparing with general NATM resin and coatings, this resin that synthesized with polyurethane and epoxy was highly stronger in intensity and longer durability. Hybrid resin was composed of polyols, MDI, epoxy, silicone surfactant, catalyst and crosslink agent, and fillers. Moreover, fillers such as fume silica not only accelerated the curing rate but also improved the physical property as thermal barriers. The rigid segments of synthetic resin in mechanical properties were due to fume silica and the increase the mole% of [NCO/OH] for corrosion protection. In conclusion, the hybrid resin microstructure with crosslink agent and fume silica are good material for thermosetting coating of metal substrates such as stainless steel.

A Study on the Ethnic Minimalism Expressed in Modern Fashion - Comparing with Minimalism - (현대 복식에 나타난 에스닉 미니멀리즘에 관한 연구 - 미니멀리즘(minimalism)과의 비교 고찰을 통하여 -)

  • Chae, Hye-Sook;Chae, Keum-Suk
    • Journal of the Korean Society of Costume
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    • v.58 no.3
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    • pp.63-78
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    • 2008
  • Since 1960, minimalism has been one of the fashion phenomenon and turned out in many different ways. After postmodernism which contains negotiation and pluralism, appeared in 1980, there was a new wave of post minimalism that inherited 1960's minimalism. Minimal style which come out of 60's fashion, is marked by simplicity, minimal expression, and monochrome color, and it shows up simple style with no decoration. It opened up a young fashion period, and we saw minimal style in sports wear which utilized simplicity and function with spread of sports in the 70's. And also since 1980, Post-Modern widely influenced the idea about modern culture as well as complicated clothes getting rid of fixed concept, seeking to break the boundary between culture and life which were seek in fashion and personality as well as various characteristic, Accordingly in different ages, The style and image were borrowed from different culture and natural environment mixing the image, cultural phenomena like these appearing in complexity and expression, variety and possibility of new vision was expanded. Since 1980, Fashion has become more gradually diversity, high classed, required of each individuality. The phenomenon of fashion reappearance which was influenced by minimalism is continued to 2000. The Oriental style fashion is still attracted, so The new term "Ethic Minimalism" has appeared along with the trends which is put together. Therefore the purpose of this study is to search the concept and the characteristics of ethnic minimalism, to consider the relationship between minimalism and ethnic minimalism, and reveal the characteristic of ethnic minimalism happened to modern fashion. The study method went through literature research and practice research. The range of this study is oriental fashion spanning of from 1960 to current day. Photo records from this period show well the spirit of the oriental and the personality of minimalism. The oriental representative designer and western representative designer are centered Consequently, The formative characteristics of ethnic minimalism are simple, pure, unbalanced free style and representing the phenomena of compromise, blending oriental and western fashion. Structually, Elements of space and plane are emphasized, colors are restricted, and materials are composed mainly of natural fiber. So, minimalism based on simplicity combined with a structure of oriental spiritual depth and space, It could be called ethnic minimalism as a rational fashion.

Design and implementation of Robot Soccer Agent Based on Reinforcement Learning (강화 학습에 기초한 로봇 축구 에이전트의 설계 및 구현)

  • Kim, In-Cheol
    • The KIPS Transactions:PartB
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    • v.9B no.2
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    • pp.139-146
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    • 2002
  • The robot soccer simulation game is a dynamic multi-agent environment. In this paper we suggest a new reinforcement learning approach to each agent's dynamic positioning in such dynamic environment. Reinforcement learning is the machine learning in which an agent learns from indirect, delayed reward an optimal policy to choose sequences of actions that produce the greatest cumulative reward. Therefore the reinforcement learning is different from supervised learning in the sense that there is no presentation of input-output pairs as training examples. Furthermore, model-free reinforcement learning algorithms like Q-learning do not require defining or learning any models of the surrounding environment. Nevertheless these algorithms can learn the optimal policy if the agent can visit every state-action pair infinitely. However, the biggest problem of monolithic reinforcement learning is that its straightforward applications do not successfully scale up to more complex environments due to the intractable large space of states. In order to address this problem, we suggest Adaptive Mediation-based Modular Q-Learning (AMMQL) as an improvement of the existing Modular Q-Learning (MQL). While simple modular Q-learning combines the results from each learning module in a fixed way, AMMQL combines them in a more flexible way by assigning different weight to each module according to its contribution to rewards. Therefore in addition to resolving the problem of large state space effectively, AMMQL can show higher adaptability to environmental changes than pure MQL. In this paper we use the AMMQL algorithn as a learning method for dynamic positioning of the robot soccer agent, and implement a robot soccer agent system called Cogitoniks.

Study for Aerodynamic and Aeroacoustic Characteristics of Multirotor Configurations Considering the Wake Interaction Effect (멀티로터형 비행체의 후류 상호작용을 고려한 공력 및 공력소음 해석 연구)

  • Ko, Jeongwoo;Kim, Dong Wook;Lee, Soogab
    • Journal of the Korean Society for Aeronautical & Space Sciences
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    • v.47 no.7
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    • pp.469-478
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    • 2019
  • Multirotor configurations such as VTOL and urban air mobility have been focused on today due to the high maneuverability. Aerodynamic and aeroacoustic characteristics of multirotor have much difference to those of a single rotor. In this study, a numerical analysis based on the free wake vortex lattice method is used for identifying the wake interaction effect. In order to compare the various configurations and operating conditions, the effects of the spacing between the rotors in hovering flight and the effects of the advancing ratio and the formation in forward flight are discussed. In the hovering flight, the unsteady loading of multirotor changes periodically and loading fluctuation increases as decreasing the spacing. It causes the variation in unsteady loading noise and the noise directivity pattern. In the forward flight, the difference in loading fluctuation and noise characteristics are observed according to the diamond and square formation of rotors. By comparing with results of single rotor analysis, multirotor configurations have different directivity pattern and amplitude of loading noise according to the location of each rotor. As a result, wake interaction effect becomes a highly important factor for aerodynamic and aeroacoustic analysis according to multirotor configurations and operating conditions.

An Exploration of IT Convergence Methods for School Forests Education (초, 중등 학교 숲 활용 교육을 위한 IT 융합 방안 탐색)

  • Kim, Sung-Ae
    • Journal of Convergence for Information Technology
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    • v.9 no.6
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    • pp.112-120
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    • 2019
  • The purpose of this study is to explore educational methods for elementary, middle and high schools using school forests via IT convergence. To this aim, we reviewed the previous literature on education using school forests to identify the problems with the existing education using school forests, and conducted interviews with experts to analyze the demands. we proposed an educational method that can utilize the school forests via IT convergence, and explored its validity through content reviews conducted by experts. The findings of this study are as follows. First, we proposed the IT convergence instruction focused on hands-on activities on top of the existing educational contents. Second, we proposed IT convergence instruction that incorporates diverse materials, physical computing tools, and programming tools. Third, we presented methods for utilizing such IT convergence instruction in connection with various elements of the 2015 Revised Curriculum as well as with various other activities such as middle school free semester activities and after-school activities. The school forest is a crucial learning space for the areas related to agriculture and biotechnology. Thus, we anticipate that the IT convergence instruction proposed in this study will lead to the re-discovery and re-evaluation of a value of school forests as an educational space that contributes to fulfilling the objective of the 2015 Revised Curriculum to nurture creative convergent talent.