• Title/Summary/Keyword: 환경자기

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An Efficient Future Indexing Technique for the Moving Object Location Prediction System (이동 객체 위치 예측 시스템을 위한 효율적인 미래 인덱싱 기법)

  • Lee, Kang-Joon;Kim, Joung-Joon;Han, Ki-Joon
    • 한국공간정보시스템학회:학술대회논문집
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    • 2007.06a
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    • pp.3-8
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    • 2007
  • 최근 도로 네트워크 환경에서 이동 객체 위치 정보를 관리하고 이동 객체의 미래 위치를 예측하는 이동 객체 위치 예측 시스템의 필요성이 나날이 증가되고 있다. 이동 객체위치 예측 시스템은 교통 관제 및 다양한 응급 상황 시 이동 객체의 미래 위치를 신속히 예측하기 위해 사용되며, 보다 편리한 위치 기반 서비스의 제공을 가능하게 해준다. 이러한 시스템을 위한 대부분의 미래 인덱싱 기법은 일반적으로 이동 객체의 미래 위치 예측을 위해 과거 이동 궤적을 이용하고 있다. 그러나, 수많은 이동 객체의 과거 이동 궤적 관리가 어렵고, 실시간으로 변화하는 이동 객체의 미래 궤적을 반영하기 위한 방대한 미래 인덱스의 갱신 요청으로 인해 인덱스 유지 비용이 증가하여 미래 위치 질의 요청에 대한 신속한 처리 성능이 떨어지게 된다. 따라서 본 논문에서는 이동 객체 위치 예측 시스템에서 방대한 이동 객체의 과거 이동 궤적으로부터 효율적으로 미래 위치를 예측하기 위해 셀 기반의 미래 인덱싱 방법인 PFCT-Tree(Probability Future Cell Trajectory-Tree)를 제시한다. PFCT-Tree는 방대한 과거 이동 궤적을 셀 단위로 재구성하여 인덱스 크기를 줄이고, 셀 내부 경험치를 기반으로 장기간 질의 시 빠른 미래 위치를 예측할 수 있다. 또한 신속한 미래 이동 궤적의 갱신 속도를 향상시키기 위해 미래 시간을 미래 궤적과 분리하여 인덱싱함으로써 위치 예측 오류로 인한 미래 인덱스 갱신 비용을 최소화 할 수 있다. 마지막으로 실험을 통해 도로 네트워크 환경에서 PFCT-Tree가 기존 인덱싱 기법들보다 갱신 및 검색 성능이 우수함도 입증하였다.ential oil (Bergamot, Grapefruit, Lemon, Petigrain)은 농도 의존적으로 ROS 생성을 증가시켰다. 이상의 결과를 종합하여 볼 때 citrus essential oil은 MSH에 의한 melanin 생성을 억제하는 것으로 보아 미백제로서의 개발 가능성이 있는 것으로 사료된다.가 사용될 수 있음을 제시한다.찍 발견되어 크기는 작았으며, 육안적으로 폴립의 Yamada 형태의 분류는 II, III의 형태를 띠고 있었다.EX>로 한반도 후기 백악기의 고지자기극$(Lat./Long.=70.9^{\circ}N/215.4^{\circ}E,\;A_{95}=5.3^{\circ})$의 위치와 유사하므로 암석의 생성 시기는 후기 백악기로 판단하였다. 한편 함평분지에 분포하는 백악기 화산암류에서는 한 개의 정자화 방향과 두 개의 역자화 방향이 확인되었다. 이들 특성잔류자화 방향은 백악기 화산암 형성 당시 암석에 기록된 성분으로써 당시 지구자기장의 상태를 기록한 것으로 해석하였으며, 이중 정자화 방향을 함평분지 화산암의 대표 방향으로 채택하였다 함평분지 화산암의 고지자기 극의 위치는 정자극의 경우는 $Lat./Long.=70.2^{\circ}N/199.5^{\circ}E,\;(K=18.1,\;A_{95}=9.6^{\circ})$ 이며 역자극의 경우는 $Lat./Long.=65.5^{\circ}S/251.3^{\circ}E,\;(K=7.1,\;A_{95}=20.7^{\circ})$이다. 이중 정자극의 위치는 한반도의 후기 백악기극의 위치와 통계적으로 동일한 것으로 나타나 함평분지 화산암

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Consumers' Subjective Risk Perceptions of Tab Water and Stated Preferences for Safe Drinking Water (소비자들의 수돗물에 대한 주관적 위험인지와 안전한 음용수에 대한 진술선호 분석)

  • Eom, Young Sook
    • Environmental and Resource Economics Review
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    • v.15 no.2
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    • pp.147-175
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    • 2006
  • This paper attempts to incorporate three important factors-perceptions, behavior and valuation-in analysing consumers' responses to health risks from environmental pollutants. Using a survey sample of 500 consumers in the Chonbuk province area, this paper empirically investigated determinants of risk perceptions from using tap water as drinking water. Most consumers were considerably concerned about health risks from drinking tap water. Moreover, those subjective concerns were not random, but were systematically related to individuals' demographic variables such as age, gender, and family size. Those subjective beliefs also influenced respondents' purchase intentions on safer water bottles, in response to a contingent behavior question of presenting two types of water bottles. The technical risk information provided in the survey had significant effects on purchase intentions only when it was interacted with respondents' actual averting practice. In addition, the sample selection effects were present by eliminating respondents who decided not to purchase either of two types of water bottles. The potential selection bias had impacts on the coefficients of the price difference variable, and subsequently the estimates of the price increments for health risk reductions.

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A Study of the Disaster Safety Management Systems on the Satellite Communication Networks for Solar Maximum (태양극대기 대비 위성통신망에 관한 재난안전관리시스템에 관한 연구)

  • Oh, Jongwoo
    • Journal of Satellite, Information and Communications
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    • v.7 no.3
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    • pp.78-85
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    • 2012
  • This paper takes precautions proposals against prospective disasters from the space weather maximum in 2013. The space weather maximum could wreak havoc in this world. A geomagnetic space storm sparked by a solar eruption like the one that flared toward earth is bound to strike again and could wreak havoc across the modern world. Despite of the fact that not only researches by colleges and institutions current researches have been focusing on warning systems of space communication and the earth network systems, but also management and control systems are not situated for the space weather blasters. The purpose of the study is that the damage reduces methods implementation on the ultimate space weather communication systems by above lists proposed type analysis. In result, the implementation of the communication disaster management systems deals with the smart IT converged GIS analysis on the flare, solar proton event, geomagnetic storm to the effects of the geomagneticsphere, ionosphere and troposphere from solar maximum. This research can provide affective methods for the saving lives and property protections that implementation of the disaster prediction and disaster prevention systems adapts smart IT systems and converged high tech information systems using decision making support systems of the GIS methodology.

Position Estimation of Autonomous Mobile Robot Using Geometric Information of a Moving Object (이동물체의 기하학적 위치정보를 이용한 자율이동로봇의 위치추정)

  • Jin, Tae-Seok;Lee, Jang-Myung
    • Journal of the Korean Institute of Intelligent Systems
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    • v.14 no.4
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    • pp.438-444
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    • 2004
  • The intelligent robots that will be needed in the near future are human-friendly robots that are able to coexist with humans and support humans effectively. To realize this, robots need to recognize their position and posture in known environment as well as unknown environment. Moreover, it is necessary for their localization to occur naturally. It is desirable for a robot to estimate of his position by solving uncertainty for mobile robot navigation, as one of the best important problems. In this paper, we describe a method for the localization of a mobile robot using image information of a moving object. This method combines the observed position from dead-reckoning sensors and the estimated position from the images captured by a fixed camera to localize a mobile robot. Using the a priori known path of a moving object in the world coordinates and a perspective camera model, we derive the geometric constraint equations which represent the relation between image frame coordinates for a moving object and the estimated robot's position. Since the equations are based or the estimated position, the measurement error may exist all the time. The proposed method utilizes the error between the observed and estimated image coordinates to localize the mobile robot. The Kalman filter scheme is applied for this method. its performance is verified by the computer simulation and the experiment.

A Study on Robust Feature Vector Extraction for Fault Detection and Classification of Induction Motor in Noise Circumstance (잡음 환경에서의 유도 전동기 고장 검출 및 분류를 위한 강인한 특징 벡터 추출에 관한 연구)

  • Hwang, Chul-Hee;Kang, Myeong-Su;Kim, Jong-Myon
    • Journal of the Korea Society of Computer and Information
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    • v.16 no.12
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    • pp.187-196
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    • 2011
  • Induction motors play a vital role in aeronautical and automotive industries so that many researchers have studied on developing a fault detection and classification system of an induction motor to minimize economical damage caused by its fault. With this reason, this paper extracts robust feature vectors from the normal/abnormal vibration signals of the induction motor in noise circumstance: partial autocorrelation (PARCOR) coefficient, log spectrum powers (LSP), cepstrum coefficients mean (CCM), and mel-frequency cepstrum coefficient (MFCC). Then, we classified different types of faults of the induction motor by using the extracted feature vectors as inputs of a neural network. To find optimal feature vectors, this paper evaluated classification performance with 2 to 20 different feature vectors. Experimental results showed that five to six features were good enough to give almost 100% classification accuracy except features by CCM. Furthermore, we considered that vibration signals could include noise components caused by surroundings. Thus, we added white Gaussian noise to original vibration signals, and then evaluated classification performance. The evaluation results yielded that LSP was the most robust in noise circumstance, then PARCOR and MFCC followed by LSP, respectively.

Engineering Characteristics of Liquid Filler Using Marine Clay and In-situ Soil (해양점토와 현장토를 활용한 유동성 채움재의 공학적 특성)

  • Oh, Sewook;Bang, Seongtaek
    • Journal of the Korean GEO-environmental Society
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    • v.21 no.9
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    • pp.25-32
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    • 2020
  • The underground utilities installed under the ground is an important civil engineering structure, such as water supply and sewerage pipes, underground power lines, various communication lines, and city gas pipes. Such underground utilities can be exposed to risk due to external factors such as concentrated rainfall and vehicle load, and it is important to select and construct an appropriate backfill material. Currently, a method mainly used is to fill the soil around the underground utilities and compact it. But it is difficult to compact the lower part of the buried pipe and the compaction efficiency decreases, reducing the stability of the underground utilities and causing various damages. In addition, there are disadvantages such as a decrease in ground strength due to disturbance of the ground, a complicated construction process, and construction costs increase because the construction period becomes longer, and civil complaints due to traffic restrictions. One way to solve this problem is to use a liquid filler. The liquid filler has advantages such as self-leveling ability, self-compaction, fluidity, artificial strength control, and low strength that can be re-excavated for maintenance. In this study, uniaxial compression strength test and fluidity test were performed to characterize the mixed soil using marine clay, stabilizer, and in-situ soil as backfill material. A freezing-thawing test was performed to understand the strength characteristics of the liquid filler by freezing, and in order to examine the effect of the filling materials on the corrosion of the underground pipe, an electrical resistivity test and a pH test were performed.

Effects on Self-esteem among Female Undergraduate Students (여대생의 자아존중감에 미치는 영향)

  • Heo, Narae
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.19 no.6
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    • pp.536-548
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    • 2018
  • This study was conducted to investigate the effects of appearance stress, alcohol intake, and eating attitude on self-esteem of female undergraduate students. Participants were 150 female undergraduate students who responded to a survey conducted from March to July of 2017. Data collected were analyzed by stepwise multiple regression analysis using an IBM SPSS 23.0. The influencing factors of self-esteem were satisfaction with college life and appearance stress, and the power of the variables was 11%. The results verified that college life and appearance stress were important factors influencing self-esteem, a critical element in the personality dimension that assesses self-affirmation. Therefore, self-esteem should be improved by providing a buffer to revitalize character resources for positive self-internalization, the formation of a healthy self-image and affect regulation which can enable one to flexibly cope with situations of appearance stress. Also, external resources should be provided inside and outside of school to help university students become cognizant of an objective perspective of the various environments of college life they face, as well as to have a positive view of themselves in college life by regulating the differences between the environments they face and their individual circumstances.

A study on teaching and learning of youth detention center school: Focused on cartoon and animation field (소년원학교 교수학습과정안 연구: 만화.애니메이션분야를 중심으로)

Paleomagnetism and Radiometric Age of Trachytes in Jeju Island, Korea (한국(韓國), 제주도(濟州島)에 산출(産出)하는 조면암류(粗面岩類)의 고지자기(古地磁氣) 및 절대연령(絶對年齡)에 관(關)한 연구(硏究))

  • Won, Jong Kwan;Matsuda, Jun-ichi;Nagao, Keisuke;Kim, Kwang Ho;Lee, Moon Won
    • Economic and Environmental Geology
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    • v.19 no.1
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    • pp.25-33
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    • 1986
  • The geology of the Jeju island is characterized by the occurrence of thick voluminous basaltic lava flows and minor trachytic lavas. The land form can be divided topographically into the lava plateau, the shield-shaped Halla volcanic edifice and the parasitic cones whose number is more than 360, which is closely related to the cyclic volcanism of the island. Especially, the trachytic lavas seem to be the latest differentiation products of the cyclic activities and largely classified into two groups (Backlokdam group and Sanbangsan group) on the basis of the occurrence and the petrography. The paleomagnetism and the radiometric age on the two groups of trachyte suggest a lower and an upper time limits of the volcanic stratigraphy of the island. An average age of the trachyte of the Sanbangsan group is $0.733{\pm}0.056m.y.$, and is correlated to a horizon a little lower than the boundary (0.69m.y.) between the Brunches normal epoch and Matuyama reversed epoch. An average age of $0.025{\pm}0.008m.y.$ determined from the Backlokdam trachyte may be corrected to anyone horizon of the Laschamp, or the Lake Biwa, or the Lake Mono excursion. The two groups of trachytes are distributed with the latitude difference of 9'($0.15^{\circ}$), and with age difference of about 0.71 m.y. Assuming that the two trachyte groups were erupted from the same stationary hot spot, the lithosphere comprising the Jeju island is considered to have moved southward with a rate of about 2.3 cm/year.

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On the Attractive Teaching Methods of Mathematics with Parents of Students (학부모와 함께 하는 흥미로운 수학지도 방안)

  • Park, Hyung-Bin;Lee, Heon-Soo
    • Journal of the Korean School Mathematics Society
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    • v.10 no.4
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    • pp.455-469
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    • 2007
  • In this study, we want to being helpful to improvement of ability to solve mathematical problem, that is grafted on the subjects being able to occur in real life, of students in teaching materials and results studied and developed in the university. For increasing ability to solve ingenious problem and growing in the learning ability of oneself leading of students. The goal of this study is to make possible open research as a result of that students look for problem around real life by one's own efforts and take interest in them through learning mathematics of parents of students, they are the most important fact of educational environment in the mathematics education - earlier than students. In particular, the goal of this study is that students have an positive attitude of mind for mathematics and maximize ability of practical application by the analytic thinking learned through experience of their parents, they survey, analyze and solve problems taken from real life in the method transmitting one's knowledge to others. This study is divided into 2 categories: education of students and education of their parents. By these, we want to disseminate advanced knowledge and theory through students improve the powers of thought, logic and inference, develop ability to solve mathematical problem, stir up motivation of learning and learn knowledge of mathematics become familiar with real life.

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