• Title/Summary/Keyword: Space-Power

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Study on Compensation Method of Anisotropic H-field Antenna (Loran H-field 안테나의 지향성 보상 기법 연구)

  • Park, Sul-Gee;Son, Pyo-Woong
    • Journal of Navigation and Port Research
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    • v.43 no.3
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    • pp.172-178
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    • 2019
  • Although the needs for providing resilient PNT information are increasing, threats due to the intentional RFI or space weather change are challenging to resolve. eLoran, which is a terrestrial navigation system that use a high-power signal is considered as a best back-up navigation system. Depending on the user's environment in the eLoran system, the user may use one of E-field or H-field antennas. H-field antenna, which has no restriction on setting stable ground and is relatively resistant to noise of general electronic equipment, is composed of two loops, and shows anisotropic gain pattern due to the different measurement at the two loops. Therefore, the H-field antenna's phase estimation value of signal varies depending on its direction even at the static environment. The error due to the direction of the signal should be eliminated if the user want to estimate the own position more precisely. In this paper, a method to compensate the error according to the geometric distribution between the H-field antenna and the transmitting station is proposed. A model was developed to compensate the directional error of H-field antenna based on the signal generated from the eLoran signal simulator. The model is then used to the survey measurement performed in the land area and verify its performance.

Principle of restoration ecology reflected in the process creating the National Institute of Ecology

  • Kim, A. Reum;Lim, Bong Soon;Seol, Jaewon;Lee, Chang Seok
    • Journal of Ecology and Environment
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    • v.45 no.3
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    • pp.105-116
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    • 2021
  • Background: The creation of the National Institute of Ecology began as a national alternative project to preserve mudflats instead of constructing the industrial complexes by reclamation, and achieve regional development. On the other hand, at the national level, the research institute for ecology was needed to cope with the worsening conditions for maintaining biodiversity due to accelerated climate change such as global warming and increased demand for development. In order to meet these needs, the National Institute of Ecology has the following objectives: (1) carries out studies for ecosystem change due to climate change and biodiversity conservation, (2) performs ecological education to the public through exhibition of various ecosystem models, and (3) promotes regional development through the ecological industry. Furthermore, to achieve these objectives, the National Institute of Ecology thoroughly followed the basic principles of ecology, especially restoration ecology, in the process of its construction. We introduce the principles and cases of ecological restoration applied in the process. Results: We minimized the impact on the ecosystem in order to harmonize with the surrounding environment in all the processes of construction. We pursued passive restoration following the principle of ecological restoration as a process of assisting the recovery of an ecosystem degraded for all the space except in land where artificial facilities were introduced. Reference information was applied thoroughly in the process of active restoration to create biome around the world, Korean peninsula forests, and wetland ecosystems. In order to realize true restoration, we pursued the ecological restoration in a landscape level as the follows. We moved the local road 6 and high-voltage power lines to underground to ensure ecological connectivity within the National Institute of Ecology campus. To enhance ecological diversity, we introduced perch poles and islands as well as floating leaved, emerged, wetland, and riparian plants in wetlands and mantle communities around the forests of the Korean Peninsula in the terrestrial ecosystem. Furthermore, in order to make the public aware of the importance of the intact nature, the low-lying landscape elements, which have disappeared due to excessive land use in most areas of Korea, was created by imitating demilitarized zone (DMZ) landscape that has these landscape elements. Conclusions: The National Institute of Ecology was created in an eco-friendly way by thoroughly reflecting the principles of ecology to suit its status and thus the impact on the existing ecosystem was minimized. This concept was also designed to be reflected in the process of operation. The results have become real, and a result of analysis on carbon budget analysis is approaching the carbon neutrality.

An Influence Analysis on the Gap Space of an Engineered Barrier for an HLW Repository (고준위폐기물처분장 공학적방벽의 갭 공간이 미치는 영향 분석)

  • Yoon, Seok;Lee, Changsoo;Kim, Min-Jun
    • Journal of the Korean Geotechnical Society
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    • v.37 no.4
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    • pp.19-26
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    • 2021
  • The high-level radioactive waste (HLW) produced from nuclear power plants is disposed in a rock-mass at a depth of hundreds meters below the ground level. Since HLW is very dangerous to human being, it must be disposed of safely by the engineered barrier system (EBS). The EBS consists of a disposal canister, backfill material, buffer material, and so on. When the components of EBS are installed, gaps inevitably exist not only between the rock-mass and buffer material but also between the canister and buffer material. The gap can reduce water-retarding capacity and heat release efficiency of the buffer material, so it is necessary to investigate properties of gap-filling materials and to analyze gap spacing effect. Furthermore, there has been few researches considering domestic disposal system compared to overseas researches. In this reason, this research derived the peak temperature of the bentonite buffer material considering domestic disposal system based on the numerical analysis. The gap between the canister and buffer material had a minor effect on the peak temperature of the bentonite buffer material, but there was 40% difference of the peak temperature of the bentonite buffer material because of the gap existence between the buffer material and rock mass.

A study on 'Life-giving function' of Dance as a performing arts (공연예술로서 무용의 '생명적 기능'에 관한 연구)

  • KIM, JI WON
    • (The) Research of the performance art and culture
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    • no.33
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    • pp.195-222
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    • 2016
  • This study says that giving a life through the mixed power of motions which can not be fixed. It is a fundamental activity of the art of dance. In the fact, the art of dance is defined as the most instinctive and intuitive arts show that dance is a harmony of emotion on the body, thus, this view wants to discuss the relations between "sense and body". This view doesn't focus on the mere motions of dancing form, but characterizes dance as an art of another vitality through the mixture and combination of these motions. In other words, this study emphasizes that dance transcends time and space on stages, and that dance, as an expression of identity, is an art which shows a sense from inside of human. Therefore, when we want to understand the true meaning of the art of dance, we should attend what attributes of dance define it as an art and show its creative. This study, thus, seeing those attributes as the life-giving function of dance, aims to help understand the principle meaning of the art of dance that realizes creation as well as the attitudes of audience who appreciate the art of dance. And by doing so, this study contemplates how we should see the creative idea of choreography, forming sympathy and the art of dance.

Implementation of A Security Token System using Fingerprint Verification (지문 인증을 이용한 보안 토큰 시스템 구현)

  • 문대성;길연희;안도성;반성범;정용화;정교일
    • Journal of the Korea Institute of Information Security & Cryptology
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    • v.13 no.4
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    • pp.63-70
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    • 2003
  • In the modern electronic world, the authentication of a person is an important task in many areas of online-transactions. Using biometrics to authenticate a person's identity has several advantages over the present practices of Personal Identification Numbers(PINs) and passwords. To gain maximum security in the verification system using biometrics, the computation of the verification as well as the store of the biometric pattern has to be taken place in the security token(smart card, USB token). However, there is an open issue of integrating biometrics into the security token because of its limited resources(memory space, processing power). In this paper, we describe our implementation of the USB security token system having 206MHz StrongARM CPU, 16MBytes flash memory, and 1MBytes RAM. Also, we evaluate the performance of a light-weighted In-gerprint verification algorithm that can be executed in the restricted environments. Based on experimental results, we confirmed that the RAM requirement of the proposed algorithm was about 6.8 KBytes and the Equal Error Rate(EER) was 1.7%.

Combined Inland-River Operation Technique for Reducing Inundation in Urban Area: The Case of Mokgam Drainage Watershed (도시지역의 침수저감을 위한 내외수 연계 운영 기법 개발: 목감천 유역을 중심으로)

  • Kwon, Soon Ho;Jung, Hyun Woo;Hwang, Yoon Kwon;Lee, Eui Hoon;Kim, Joong Hoon
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.22 no.1
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    • pp.257-266
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    • 2021
  • Urban areas can often suffer flood damage because of the more frequent catastrophic rainfall events from climate change. Flood mitigation measures consist of (1) structural and (2) non-structural measures. In this study, the proposed method focused on operating an urban drainage system among non-structural measures. The combined inland-river operation technique estimates the inflow of pump stations based on the water level obtained from a preselected monitoring point, and the pump station expels the stored rainwater to the riverside based on those estimates. In this study, the proposed method was applied to the Mokgam drainage watershed, where catastrophic rainfall events occurred (i.e., 2010- and 2011-years), and severe flood damage was recorded in Seoul. Using the proposed method, the efficiency of flood reduction from the two rainfall events was reduced by 34.9 % and 54.4 %, respectively, compared to the current operation method. Thus, the proposed method can minimize the flood damage in the Mokgam drainage watershed by reserving the additional storage space of a reservoir. In addition, flooding from catastrophic rainfall can be prevented, and citizens' lives and property in urban areas can be protected.

A Numerical Study on the Step 0 Benchmark Test in Task C of DECOVALEX-2023: Simulation for Thermo-Hydro-Mechanical Coupled Behavior by Using OGS-FLAC (DECOVALEX-2023 Task C 내 Step 0 벤치마크 수치해석 연구: OGS-FLAC을 활용한 열-수리-역학 복합거동 수치해석)

  • Kim, Taehyun;Park, Chan-Hee;Lee, Changsoo;Kim, Jin-Seop
    • Tunnel and Underground Space
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    • v.31 no.6
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    • pp.610-622
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    • 2021
  • The DECOVALEX project is one of the representative international cooperative projects to enhance the understanding of the complex Thermo-Hydro-Mechanical-Chemical(THMC) coupled behavior in the high-level radioactive waste disposal system based on the numerical simulation. DECOVALEX-2023 is the current phase consisting of 7 tasks, and Task C aims to model the THM coupled behavior in the disposal system based on the Full-scale Emplacement (FE) experiment at the Mont-Terri underground rock laboratory. This study performs the numerical simulation based on the OGS-FLAC developed for the current study. In the numerical model, we emplaced the heater with constant power horizontally based on the FE experiment and monitored the pressure development, temperature increase, and mechanical deformation at the specific monitoring points. We monitored the capillary pressure as the primary effect inducing the flow in the buffer system, and thermal stress and pressurization were dominant in the surrounding rocks' area. The results will also be compared and validated with the other participating groups and the experimental data further.

Changes in the Energy Landscape from Multi-Level Perspective: A Case Study of the Photovoltaic Module Carbon Certification System (다층적 관점에서 바라본 에너지경관의 변동: 태양광 모듈 탄소인증제를 사례로)

  • Jang, Geunyong
    • Journal of the Economic Geographical Society of Korea
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    • v.24 no.4
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    • pp.367-385
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    • 2021
  • This study examined changes in the energy landscape, focusing on the photovoltaic module carbon certification system. As the global photovoltaic market has been reorganized around Chinese companies, the South Korean government has pushed to strengthen the competitiveness of the nation's photovoltaic industry. However, a limitation remains in that the government-led effort was not sufficient to bring about dynamic changes in the energy landscape. Against this backdrop, this study explored the stages leading to the multi-level perspectives of "macro-environment, socio-technical regime, and niche" to track the process of the government and domestic photovoltaic companies as part of a socio-technical regime responding to global market changes. In particular, this study raised an issue with the conceptual discussion of multi-level perspective, which placed a particular emphasis on the rate of change at each level and the niche in which innovative experiments take place, and thus attempted to fill this gap by tracking the energy landscape that varies differently from space. These spatial discussions can track different carbon emissions coefficients and industrial characteristics for each country, and have a higher level of explanatory power for the system thus constructed. In addition, through discussions on the problems and implications of the government-led introduction of renewable energy policies, this study suggests the need to create and implement a field-oriented system.

Position Control of Dual Redundant Asymmetric Tandem Electro-Hydrostatic Actuator for Aircraft based on Backstepping Technique (백스테핑 기법을 이용한 항공기용 이중화 비대칭형 직렬 전기-정유압 구동기의 위치제어)

  • Kim, Daeyeon;Park, Hyung Jun;Kim, Sang Seok;Kim, Dae Hyun;Kim, Sang Beom;Lee, Junwon;Choi, Jong Yoon
    • Journal of Aerospace System Engineering
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    • v.15 no.3
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    • pp.1-10
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    • 2021
  • The electro-hydrostatic actuators (EHA) are widely used in various industrial fields since they can independently execute the function of the hydraulic power source and have high efficiency. Particularly, in the aviation field, the EHA is mainly designed as dual redundant asymmetric tandem actuator to mitigate failure and minimize installation space. However, aviation EHAs designed in the form of dual redundant asymmetric tandem actuator have the disadvantage of decreased durability performance due to the occurrence of force fighting. In this paper, the controller is designed based on backstepping technique to improve control performance and reduce force fighting for aviation EHA. The augmented state observer is proposed to estimate the states required for control. Through simulation, it was verified that the proposed controller had superior control performance and significantly reduces the force fighting compared to the general PI controller.

The Formal Innovation and Social Reflection of Korean Web Fiction Fantasy -Centered on 'Book Traveler' Genre (한국 웹소설 판타지의 형식적 갱신과 사회적 성찰 -책빙의물을 중심으로)

  • Yu, In-Hyeok
    • Journal of Popular Narrative
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    • v.26 no.1
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    • pp.77-102
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    • 2020
  • This article analyzes 'book traveler' stories as a new sub-genre of Korean fantasy web fiction. Formal innovation is revealed as the major motivation of Korean fantasy web fiction's narratives. Furthermore, the imagination of social resistance was presented as the formal devices of the genre. These theses were performed during the analysis of the two characteristics of the genre. In this genre, the main character is the writer or reader of fantasy stories. He moves into a novel he is describing or reading. The original novel, which was entered by the main character, is a space characterized by the custom of a typical fantasy genre. Therefore, the main character actually experiences cliché, typical genre devices and plots. The most important action for the main character here is to 'bend' the custom of the original. Therefore, this genre is in the form of the main motive being the refraction of typology. Meanwhile, the main character is not the central character of the original, but a secondary figure. The central character of the original book is usually from the ruling class, which monopolizes the good resources of society. At this time, the genre creates a subversive situation in which the social underdog goes beyond the social power through plots that overwhelm the central figure. It converts the reader's social desire into a genre device. To summarize, the latest trend in Korean web novel fantasy has captured scenes of renewed Korean genre literature practices. It sensitively reflects the social context of the contemporaries and the reader's desire. Thus, the Korean web novel fantasy has reflected both its internal conditions and its social context.