• Title/Summary/Keyword: engineering problem

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Noise-robust electrocardiogram R-peak detection with adaptive filter and variable threshold (적응형 필터와 가변 임계값을 적용하여 잡음에 강인한 심전도 R-피크 검출)

  • Rahman, MD Saifur;Choi, Chul-Hyung;Kim, Si-Kyung;Park, In-Deok;Kim, Young-Pil
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.18 no.12
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    • pp.126-134
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    • 2017
  • There have been numerous studies on extracting the R-peak from electrocardiogram (ECG) signals. However, most of the detection methods are complicated to implement in a real-time portable electrocardiograph device and have the disadvantage of requiring a large amount of calculations. R-peak detection requires pre-processing and post-processing related to baseline drift and the removal of noise from the commercial power supply for ECG data. An adaptive filter technique is widely used for R-peak detection, but the R-peak value cannot be detected when the input is lower than a threshold value. Moreover, there is a problem in detecting the P-peak and T-peak values due to the derivation of an erroneous threshold value as a result of noise. We propose a robust R-peak detection algorithm with low complexity and simple computation to solve these problems. The proposed scheme removes the baseline drift in ECG signals using an adaptive filter to solve the problems involved in threshold extraction. We also propose a technique to extract the appropriate threshold value automatically using the minimum and maximum values of the filtered ECG signal. To detect the R-peak from the ECG signal, we propose a threshold neighborhood search technique. Through experiments, we confirmed the improvement of the R-peak detection accuracy of the proposed method and achieved a detection speed that is suitable for a mobile system by reducing the amount of calculation. The experimental results show that the heart rate detection accuracy and sensitivity were very high (about 100%).

Analysis of Orthotropic Body under Ultimate Moment Load (극한(極限)모멘트 하중(荷重)을 받는 이방성(異方性) 구조체(構造體)의 해석(解析))

  • Chang, Suk Yoon
    • KSCE Journal of Civil and Environmental Engineering Research
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    • v.5 no.3
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    • pp.95-105
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    • 1985
  • This dissertation presents an exact solution for the normal and shearing stresses of an orthotropic plane body loaded by a moment load. The solution satisfies the conditions of equilibrium compatibility equations concurrently and is governing for the body being in the elasto-plastic state. An Airy stress function is introduced to solve the problem related to an orthotropic half-infinite plane under a moment load. All the equations for orthotropy must be degenerated into the expressions for isotropy when orthotropic constants are replaced by isotropic ones. The author has evaluated all the equations of orthotropy and succeeded in obtaining exactly identical expressions to the equations of isotropy which were derived independently by of L'hosptials rule. The analytical results of isotropy are compared with the simple results of other investigator. Since moment Load under the elastic state and plastic state only is a particular case of moment load under the elasto-plastic state. All the equations of elasto-plastic state case are degenerated into the expressions for the each case. The formal solution is expressed in terms of closed form. The orthotropic constants are evaluated for two kinds and two different orientations of the grain of wood and two kinds of structures. The numerical results for orthotropy are evaluated for one kind and two different orientations of three-layered ply wood. The distribution of normal and shearing stresses are shown in figures. It is noted that the distribution of stresses of orthotropic materials depends on the type of materials and orientations of the grain and stiffening.

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Applications of "High Definition Digital Climate Maps" in Restructuring of Korean Agriculture (한국농업의 구조조정과 전자기후도의 역할)

  • Yun, Jin-I.
    • Korean Journal of Agricultural and Forest Meteorology
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    • v.9 no.1
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    • pp.1-16
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    • 2007
  • The use of information on natural resources is indispensable to most agricultural activities to avoid disasters, to improve input efficiency, and to increase lam income. Most information is prepared and managed at a spatial scale called the "Hydrologic Unit" (HU), which means watershed or small river basin, because virtually every environmental problem can be handled best within a single HU. South Korea consists of 840 such watersheds and, while other watershed-specific information is routinely managed by government organizations, there are none responsible for agricultural weather and climate. A joint research team of Kyung Hee University and the Agriculture, forestry and Fisheries Information Service has begun a 4-year project funded by the Ministry of Agriculture and forestry to establish a watershed-specific agricultural weather information service based on "high definition" digital climate maps (HD-DCMs) utilizing the state of the art geospatial climatological technology. For example, a daily minimum temperature model simulating the thermodynamic nature of cold air with the aid of raster GIS and microwave temperature profiling will quantify effects of cold air drainage on local temperature. By using these techniques and 30-year (1971-2000) synoptic observations, gridded climate data including temperature, solar irradiance, and precipitation will be prepared for each watershed at a 30m spacing. Together with the climatological normals, there will be 3-hourly near-real time meterological mapping using the Korea Meteorological Administration's digital forecasting products which are prepared at a 5 km by 5 km resolution. Resulting HD-DCM database and operational technology will be transferred to local governments, and they will be responsible for routine operations and applications in their region. This paper describes the project in detail and demonstrates some of the interim results.

Evaluation of Indoor Air Quality in a Department of Radiation Oncology Located Underground (지하에 위치한 방사선종양학과에서의 실내공기 질 평가)

  • Kim, Won-Taek;Shin, Yong-Chul;Kang, Dong-Mug;Ki, Yong-Kan;Kim, Dong-Won;Kwon, Byung-Hyun
    • Radiation Oncology Journal
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    • v.23 no.4
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    • pp.243-252
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    • 2005
  • Purpose: Indoor air quality (IAQ) in the radiation treatment center which is generally located underground is important to the health of hospital workers and patients treated over a long period of time. this study was conducted to measure and analyze the factors related to IAQ and subjective symptoms of sick building syndrome, and to establish the causes influencing IAQ and find a solution to the problems. Methods and Materials : Self administrated questionnaire was conducted to check the workers' symptoms and understanding of the work environment. Based on a preliminary investigation, the factors related to IAQ such as temperature, humidity, fine particulate. carbon dioxide, carbon monoxide, formaldehyde, total volatile organic compounds (TVOC), and radon gas were selected and measured for a certain period of time in specific sites where hospital workers stay long in a day. And we also evaluated the surrounding environment and the efficiency of the ventilating system simultaneously, and measured the same factors at the first floor (outdoor) to compare with outdoor all quality, All collected data were assessed by the recommended standard for IAQ of the domestic and international environmental organizations. Results: Hospital workers were discontented with foul odors, humidity and particulate. They complained symptoms related to musculo-skeletal system, neurologic system, and mucosal-irritatation. Most of the factors were not greater than the recommended standard, but the level of TVOC was third or fourth times as much as the measuring level of some offices in the United States. The frequency and the amount of the ventilating system were adequate, however, the problem arising in the position of outdoor-air inlets and indoor-air outlets involved a risk of the indraft of contaminated air. A careful attention was a requirement in handling and keeping chemical substances including a developing solution which has a risk of TVOC emissions, and repositioning the ventilating system was needed to solve the contaminated-air circulation immediately Conclusion We verified that some IAQ-related factors and inadequate ventilating system could cause subjective symptoms in hospital workers. The evaluation of IAQ was surely needed to improve the underground working environments for hospital workers and patients. On the basis of these data, from now on, we should actively engage in designs of the department of radiation oncology or improvement in environments of the existing facilities.

Improvement of Rotary Tine for Barley Seeder Attached to Rotary Tiller (로우터리 맥류파종기 경운날의 개량시험)

  • 김성래;김문규;김기대;허윤근
    • Journal of Biosystems Engineering
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    • v.4 no.1
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    • pp.1-23
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    • 1979
  • The use of barley seeder attached to rotary tiller in the rural area has a significant meaning not only for the solution of labor peak season, but also for the increase of land utilization efficiency. The facts that presently being used barley seeders are all based on the mechanical principles of the reverse rotation, center drive and are all using forward rotating tine, which is used to be easily and heavily worn out when it rotates reversely, raise problem of recommending them to rural area in Korea. Therefore, the main objective of the study was to develop new type of rotary tine attachable to barley seeders. To attain the objective the following approaches were applied. (1) The kinematic analysis of reverse rotating barley seeders. (2) The studies on the soil bin and artificial soil. (3) The comparative experiment on the power requirement of prototype tine. The results obtained from the studies are summarized as follow: 1. The kinematic analysis of barley seeder attached to rotary tiller: The following results were obtained from the kinematic analysis for deriving general formulae of the motion and velocity characterizing the rotary tine of barley seeders presently being used by farmers. a) The position vector (P) of edge point (P) in the rotary tine of reverse rotating, center drive was obtained by the following formula. $$P=(vt+Rcos wt)i+Rsin wt j+ \{ Rcos \theta r sin \alpha cos (wt- \beta +\theta r) +Rsin \theta r sin \alpha sin (wt-\beta + \theta r) \} lk $$ b) The velocity of edge point $(P^')$ of reverse rotating, center drive rotary tine was obtained by the following formula. $$(P^')=(V-wR sin wt)i+(w\cdot Rcoswt)j + \{ -w\cdot Rcos \theta r\cdot sin \alpha \cdot sin (wt-\beta +\theta r) + w\cdot Rsin \theta r\cdot sin \alpha \cdot cos (wt- \beta + \theta r \} k $$ c) In order to reduce the power requirement of rotary tine, the angle between holder and edge point was desired to be reduced. d) In order to reduce the power requirement, the edge point of rotary tine should be moved from the angle at the begining of cutting to center line of machine, and the additional cutting width should be also reduced. 2. The studies on the soil bin and artificial soil: In order to measure the power requirement of various cutting tines under the same physical condition of soil, the indoor experiments Viere conducted by filling soil bin with artificially made soil similar to the common paddy soil and the results were as follows: a) When the rolling frequencies$(x)$ of the artificial soil were increased, the densIty$(Y)$ was also increased as follows: $$y=1.073200 +0.070780x - 0.002263x^2 (g/cm^3)$$ b) The absolute hardness $(Y)$ of soil had following relationship with the rolling frequencies$(x)$ and were increased as the rolling frequencies were increased. $$Y=37.74 - \frac {0.64 + 0.17x-0. 0054x^2} {(3.36-0.17x + 0.0054x^2)^3} (kg/cm^3)$$ c) The density of soil had significant effect on the cohesion and angle of internal friction of soil. For instance, the soil with density of 1.6 to 1.75 had equivalent density of sandy loam soil with 29.5% of natural soil moisture content. d) The coefficient of kinetiic friction of iron plate on artificial soil was 0.31 to 0.41 and was comparable with that of the natural soil. e) When the pulling speed of soil bin was the 2nd forward speed of power tiller, the rpm of driving shaft of rotary was similar to that of power tiller, soil bin apparatus is indicating the good indoor tester. 3. The comparative experiment on the power requirement of prototype tine of reverse rotating rotary: According to the preliminary test of rotary tine developed with various degrees of angle between holder and edge pcint due to the kinematic analysis, comparative test between prototype rotary tine with $30 ^\circ $ and $10 ^\circ$ of it and presently being used rotary tine was carried out 2nd the results were as follows: a) The total cutting torque was low when the angle between holder and edge point was reduced. b) $\theta r$ (angle between holder and edge point) of rotary tine seemed to be one: of the factors maximizing the increase of torque. c) As the angle between holder and edge point ($\theta r$) of rotary tine was $30 ^\circ $ rather than $45 ^\circ $, the angle of rotation during cutting soil was reduced and the total cutting torque was accordingly reduced about 10%, and the reduction efficiency of total cutting torque was low when the angle between holder and edge point ($\theta r$) of rotary tine was $10 ^\circ $, which indicates that the proper angle between holder and edge point of rotary tine should be larger than $10 ^\circ $ and smaller than $30 ^\circ $ . From above results, it could be concluded that the use of the prototype rotary tine which reduced the angle between holder and edge point to $30 ^\circ $, insted of $45 ^\circ $, is disirable not only decreasing the power requirements, but also increasing the durabie hour of it. Also forward researches are needed, WIlich determine the optimum tilted angle of rotary brocket, and rearrangement of the rotary tine on the rotary boss.

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Study on the Stability Evaluation of Concrete Erosion Control Dam by using Non-destructive Test for Compressive Strength (콘크리트 비파괴시험법을 이용한 사방댐 안정도 평가에 관한 연구)

  • Park, Ki-Hyung;Kim, Min-Sik;Joh, Sung-Ho;Lee, Chang-Woo;Youn, Ho-Joong;Kim, Kyong-Ha
    • Journal of Korean Society of Forest Science
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    • v.102 no.1
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    • pp.90-96
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    • 2013
  • This study was conducted to investigate a stability trend within 6 above average and 4 blow average erosion control dams, which were selected by The Korean Association of Soil and Water Conservation and were built in 1990s in Gyeonggi and Gangwon Province. The study was aimed to measure rebound hardness of upstream face, flood way and downstream face from those dams selected by using 'Concrete Test Hammer'. The main purposes of the study are selection of compression strength prediction equation and scope of wavelength, which successfully demonstrate non-destructive test results for erosion control dams. There is an opportunity to increase disaster prevention ability when stability vulnerability of concrete erosion control dam is detected in a timely manner. Results of the compression strength investigation express that there is a consistency with visual inspection of stability that has been processed by The Korean Association of Soil and Water Conservation. We concluded that a prediction equation, which was developed by Architectural Institute of Japan (AIJ), shows highest suitability in Korean erosion control dams when stability investigation is performed. The detailed criteria for the test result are 'stable', 'detail inspection required' and 'poor' for over 300 $kgf/cm^2$, 250~300 $kgf/cm^2$ and below 250 $kgf/cm^2$ respectively. Standards for stability of Korean erosion control dam and a compression strength prediction equation (that corresponds to the standards of the stability) should be established on the basis of chronological data of erosion control dam compression strength. Systematical approach for stability inspection that carries out remodeling or repair when problem on erosion control structures are detected through visual inspection and simple stability test, is necessary for the future disaster prevention.

Enhanced PHB Accumulation in Photosystem- and Respiration-defective Mutants of a Cyanobacterium Synechocystis sp. PCC 6803 (Synechocystis sp. PCC 6803의 에너지 대사 결함 돌연변이 균주에서의 Poly(3-hydroxybutyrate) 축적량 증진)

  • Kim Soo-Youn;Choi Gang Guk;Park Youn Il;Park Young Mok;Yang Young Ki;Rhee Young Ha
    • Korean Journal of Microbiology
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    • v.41 no.1
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    • pp.67-73
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    • 2005
  • Photoautotrophic bacteria are promising candidates for the production of poly(3-hydroxybutyrate) (PHB) since they can address the critical problem of substrate costs. In this study, we isolated 25 Tn5-inserted mutants of the Synechocystis sp. PCC 6803 which showed enhanced PHB accumulation compared to the wild-type strain. After 5-days cultivation under nitrogen-limited mixotrophic conditions, the intracellular levels of PHB content in these mutants reached up to $10-30\%$ of dry cell weight (DCW) comparable to $4\%$ of DCW in the wild-type strain. Using the method of inverse PCR, the affected genes of the mutants were mapped on the completely known genome sequence of Synechocystis sp. PCC 6803. As a result, the increased PHB accumulation in 5 mutants were found to be resulted from defects of genes coding for NADH-ubiquinone oxidoreductase, O-succinylbenzoic-CoA ligase, photosystem II PsbT protein or histidine kinase, which are involved in photosystem in thylakoid inner membrane of the cell. The values of $NAD(P)H/NAD(P)^+$ ratio in the cells of these mutants were much higher than that of the wild-type strain as measured by using pulse-amplitude modulated fluorometer, suggesting that PHB synthesis could be enhanced by increasing the level of cellular NAD(P)H which is a limiting substrate for NADPH-dependent acetoacetyl-CoA reductase. From these results, it is likely that NAD(P)H would be a limiting factor for PHB synthesis in Synechocystis sp. PCC 6803.

A Study on the Origin and Transformation of Jeonju-Palkyung (전주팔경의 시원(始原)과 변용(變容)에 관한 연구)

  • Rho, Jae-Hyun;Son, Hee-Kyung;Shin, Sang-Sup;Choi, Jong-Hee
    • Journal of the Korean Institute of Traditional Landscape Architecture
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    • v.33 no.3
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    • pp.1-15
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    • 2015
  • Based on the analysis and interpretation of the headwords and poetic words of a group of eleven collecting sceneries of Jeonju, the origin and transformations of the Jeonju-Palkyung(Eight sceneries of Jeonju) investigated by a time-series analysis are as follows. As there is no collection of landscape with a formal structure similar to that of the current Jeonju-Palkyung, prior to the Palkyung by Chujae(秋齋) Cho Soo-Sam(趙秀三, 1762~1849), there is no significant problem in assuming the eight poems in Chujaejib(秋齋集) are the origins of the Jeonju-Palkyung, and it is estimated to have been produced in 1829. In the late-19th century poem 'Wansanseunggyeong(完山勝景)', 'the Palkyung in Yeollyeo Chunhyang Sujeolga', and 'the Palkyung delivered by poet Shin Seokjeong in the Japanese colonial era', only the 'Dongpogwibeom(東浦歸帆)' changed from Dongjipo to Dongchon of Bongdong as for 'Landscape Setting There($L_{ST}$)' according to changes in district administration; despite this change, the fact that they are not too different from the Palkyung of Cho Soo-Sam, also supports this. Moreover, according to the headword concordance analysis, it is proven that the Jeonju-Palkyung was established in the late-19th century and continued to be the region's representative sceneries even during the Japanese colonial era, and later 'Namcheonpyomo(南川漂母)' and 'Gonjimangwol(坤止望月)' were added to expand to the Jeonju-Sipkyung(ten sceneries of Jeonju). But when we see there are famous spots that are the origins of the Jeonju-Sipkyung, including Gyeonggijeon, Geonjisan, Jogyeongdan, Omokdae, and Girinbong, Deokjinyeon, and Mangyeongdae, all of which have great representational significance as the capital of Jeolla Provincial Office as well as of the place of origin for Joseon Dynasty in the grouping of sceneries during the early Joseon Dynasty, including "Paehyangsipyeong (沛鄕十詠)", "Gyeondosipyeong (甄都十詠)", and "Binilheonsipyeong(賓日軒十詠)", the beginnings of the semantic Jeonju-Palkyung should be considered up to the first half of Joseon Dynasty. During this period, not only the fine sceneries with high retrospective merit as the capital of Hubaekje, like Gyeonhwondo(甄萱都), but also the sceneries like Mangyeongdae that reminds people of Jeong Mongju(鄭夢周) and Yi Seonggye(李成桂) in the late period of Goryeo appeared, elevating the status of Jeonju as the capital of Hubaekje and shortening the historical gaps as the place of origin of the Joseon Dynasty. The Jeonju-Palkyung is an organic item that carries the history of the Joseon Dynasty after Hubaekje and has gone through many cycles of disappearing and reappearing, but it has continued to change and transform as the region's representative sceneries. The Jeonju-Palkyung is a cultural genealogy that helps one understand the 'Jeonju Hanpunggyeong(韓風景: the sceneries of Korea in Jeonju)', and the efforts to preserve and pass it down to the next generation would be the responsibility of the people of Jeonju.

A Study on Intuitive IoT Interface System using 3D Depth Camera (3D 깊이 카메라를 활용한 직관적인 사물인터넷 인터페이스 시스템에 관한 연구)

  • Park, Jongsub;Hong, June Seok;Kim, Wooju
    • The Journal of Society for e-Business Studies
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    • v.22 no.2
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    • pp.137-152
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    • 2017
  • The decline in the price of IT devices and the development of the Internet have created a new field called Internet of Things (IoT). IoT, which creates new services by connecting all the objects that are in everyday life to the Internet, is pioneering new forms of business that have not been seen before in combination with Big Data. The prospect of IoT can be said to be unlimited in its utilization. In addition, studies of standardization organizations for smooth connection of these IoT devices are also active. However, there is a part of this study that we overlook. In order to control IoT equipment or acquire information, it is necessary to separately develop interworking issues (IP address, Wi-Fi, Bluetooth, NFC, etc.) and related application software or apps. In order to solve these problems, existing research methods have been conducted on augmented reality using GPS or markers. However, there is a disadvantage in that a separate marker is required and the marker is recognized only in the vicinity. In addition, in the case of a study using a GPS address using a 2D-based camera, it was difficult to implement an active interface because the distance to the target device could not be recognized. In this study, we use 3D Depth recognition camera to be installed on smartphone and calculate the space coordinates automatically by linking the distance measurement and the sensor information of the mobile phone without a separate marker. Coordination inquiry finds equipment of IoT and enables information acquisition and control of corresponding IoT equipment. Therefore, from the user's point of view, it is possible to reduce the burden on the problem of interworking of the IoT equipment and the installation of the app. Furthermore, if this technology is used in the field of public services and smart glasses, it will reduce duplication of investment in software development and increase in public services.

A Study on Comparison and Analysis of Civic Education in Place for Children -A Case Study on the United States, Britain, Finland, Japan, and South Korea- (어린이 공간교육의 국내외 사례 비교연구 -미국, 영국, 핀란드, 일본, 한국의 사례를 중심으로-)

  • Hue, Youn-Sun;Im, Seung-Bin
    • Journal of the Korean Institute of Landscape Architecture
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    • v.39 no.2
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    • pp.40-51
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    • 2011
  • Recently, the public's interest in quality of life and good design has increased, and the opportunities for their participation in space planning and the design process are expanding. However, the public still lacks understanding of the role(and importance) of space and environment and is not experienced in expressing their opinion on improving the urban environment. At this point, 'Built Environment Education for Kids' will be the key to understanding space and environment as future citizens and to developing the ability of problem-solving and expressing their opinions. This study aims to change the awareness of the public as well as experts, and to make a better urban space through comparison and analysis of domestic and foreign 'Built Environment Education.' In 27 countries around the world(more than 110 institutions), 'Built Environment Education' from childhood is being implemented. Such movements aim to make people participate in the space design and decision-making process by understanding a fundamental element of the built environment and space perception. In this study, the United States, Britain, Finland, Japan and South Korea's 'Built Environment Education' are discussed Above all, the definition, range and target of 'Built Environment Education' are discussed For each case, the purpose and effect, laws and educational processes, systems and roles, and examples of programs are analyzed. Through reviewing each attribute and their implications, a conclusion is drawn on the aspects we have to consider in laying the foundation for implementing the 'Built Environment Education' in Korea, such as consideration of the locality, organizing systematic networks and composing a pool of experts, building proper institutions, and establishing the role of the government. This case study of 'Built Environment Education' can help increase the awareness of the public and build their strength in establishing a better future space. Through the analysis of the purpose, laws, systems, and contents, this case study is expected to provide and build the foundation for an educational system and develop an appropriate program that best suits our society.