• Title/Summary/Keyword: science and engineering practice

Search Result 580, Processing Time 0.032 seconds

A Study on Valuation of Foreign Real Estate Investment using Real Option (실물옵션을 이용한 해외 부동산 투자 가치평가 연구)

  • Gu, Seung-Hwan;Ping, Wang;Jang, Seong Yong
    • Journal of the Korea Academia-Industrial cooperation Society
    • /
    • v.14 no.11
    • /
    • pp.5465-5475
    • /
    • 2013
  • In this study, when to invest in real estate abroad, to present a real option in the way of decision-making. Thus, by using the binomial option model of one of the real thing and DCF, we compared the choice of real estate investment in China and South Korea. Research concerns the real estate market of Shanghai and Seoul, Analyzed the data between 2001-2009. Results were calculated NPV investment period (Net Present Value), Seoul appears in 435.44, Shanghai was 398.26. Investment decision by NPV method will select Seoul. However, as a result of calculating the value using the real option, it was found that for Seoul appear in 615.4, Shanghai has been shown to 626.1, and is suitable for investment in Shanghai. Assuming on the basis of this, that it has invested in practice, and compare the results, Seoul is intended for since 2010, real estate prices fell to 2013 currently, damage has occurred, profit's occurred Shanghai. This ensures that when making decisions in real estate investment and to use the real option than the existing DCF is appropriate.

Simulation-based Education Model for PID Control Learning (PID 제어 학습을 위한 시뮬레이션 기반의 교육 모델)

  • Seo, Hyeon-Ho;Kim, Jae-Woong;Park, Seong-Hyun
    • Journal of Convergence for Information Technology
    • /
    • v.12 no.3
    • /
    • pp.286-293
    • /
    • 2022
  • Recently, the importance of elemental technologies constituting smart factories is increasing due to the 4th Industrial Revolution, and simulation is widely used as a tool to learn these technologies. In particular, PID control is an automatic control technique used in various fields, and most of them analyze mathematical models in certain situations or research on application development with built-in controllers. In actual educational environment requires PID simulator training as well as PID control principles. In this paper, we propose a model that enables education and practice of various PID controls through 3D simulation. The proposed model implemented virtual balls and Fan and implemented PID control by configuring a system so that the force can be lifted by the air pressure generated in the Fan. At this time, the height of the ball was expressed in a graph according to each gain value of the PID controller and then compared with the actual system, and through this, satisfactory results sufficiently applicable to the actual class were confirmed. Through the proposed model, it is expected that the rapidly increasing elemental technology of smart factories can be used in various ways in a remote classroom environment.

The Measurements of Energy and Distribution of Scattered Electrons in Therapeutic X-Ray Beam (치료 방사선 선속(Flux)에 포함된 산란전자의 분포와 에너지 측정)

  • Vahc, Young-Woo;Park, Kyung-Ran;Ohyun Kwon;Lee, Yong-Ha;Kim, Tae-Hong;Kim, Sookil
    • Progress in Medical Physics
    • /
    • v.13 no.1
    • /
    • pp.1-8
    • /
    • 2002
  • Accurate knowledge of the distribution of contamination electrons ( which comes from mainly gantry head by Compton scattering, pair production, and tray: henceforth called leptons ) at the surface and in the first centimeters of tissue is essential for the clinical practice of radiation oncology. Such lepton tends to reduce or eliminate the ‘skin-sparing’ advantage of megavoltage photon beam radiotherapy, This information is needed to prescribe a absorbed dose to a skin volume at a few millimeter depth in high energy therapeutic radiation photon beam All experiments were done with 15 MV photon beam from a dual energy linear accelerator (Clinac 1800, Varian). Field size is defined by ranged from 10.0$\times$10.0 to 30.0$\times$30.0 $\textrm{cm}^2$. The absorbed dose and distribution of leptons in therapeutic radiation beam (15 MV) are investigated by means of variable blocked beams of 30.0$\times$30.0 $\textrm{cm}^2$ and dose beam profiles partly removed leptons with a copper plate. A numerous leptons mainly are distributed as shape of broad cone in the central photon beam and leptons path length in the water are shorter than 2.5 cm because of the leptons energy having around 3.0 MeV. These results clearly appears that the subtraction of leptons from the total depth dose curve not only lower the absolute dose in the buildup region and surface dose, it also causes a shift of d$_{max}$ to a deeper depth.

  • PDF

The Production Structure of Genetic Information in South Korea (한국의 유전적 정보 생산 구조)

  • Yi Cheong-Ho
    • Journal of Science and Technology Studies
    • /
    • v.5 no.1 s.9
    • /
    • pp.55-92
    • /
    • 2005
  • The factors contributing to the formation of an important scientific concept in South Korea and its circulation in the society are the scientific knowledge that had been already formed, matured, and established in the U.S.A, Europe and Japan and has been introduced into Korea, and the institutions that have been formed during the recent modernization in South Korea. The concept of 'genetic information' cannot be an exception in this context. The concept of genetic information is the one that has been extended and intensified by the genomics and bioinformatics formed and matured through the Human Genome Projects from the former concept of inheritance or heredity within the framework of classical and molecular genetics. The purpose of this study was to find out 'how the production structure of genetic information in South Korea has been formed', under the perspective of the conceptual, epistemic, and institutional holisticity or integratedness in the concept and knowledge production structure idealized in Western advanced nations. The discourse of genetic engineering popular in the mid 1980's in South Korea has catalyzed the development of molecular biology. However, the institutional balance that had been established for the biochemistry departments in Natural Science College and Medical College was not formed between the genetic engineering and genetics departments in South Korea. Therefore, they were unable to achieve the more integrative and macro-level disciplinary impact on life sciences, largely due to institutional lack of the capable (human) genetics departments in some leading Korean colleges of Medicine. In genomics, the cutting-edge reprogramming and restructuring of the traditional genetics in the West, South Korea has not invested, even meagerly, in the infrastructure, fund, and research and development (R & D) for the Basic or First Phase of the research trajectory in the Human Genome Project. Without a minimal Basic Phase, the genomics research and development in Korea has been running more or less for the Advanced or Second Phase. Bioinformatics has started developing in Korea under a narrow perspective which regards it as a mere sub-discipline of information technology (IT). Having developed itself in parallel with genomics, bioinformatics contains its own unique logics and contents that can be both directly and indirectly connected to the information science and technology. As a result, bioinformatics reveals a defect in respect of being synergistically integrated into genetics and life sciences in Korea. Owing to the structural problem in the production, genetic information appears to be produced in a fragmented pattern in the Korean society since its fundamental base is weak and thin. A good example of the conceptual and institutional fragmentedness is that 'the genetics of individual identification' is not a normal integrated part of the Korean genetics, but a scientific practice exercised in the departments of legal medicine in a few Medical Colleges. And the environment contributing to the production structure of genetic information in South Korea today comprises 'sangmyung gonghak'(or life engineering) discourse and non-governmental organization movement.

  • PDF

A Study on the Change in Microstructures of Traditional Forged High Tin Bronzes by Quenching (담금질 조건에 따른 방짜유기의 미세조직 변화 연구)

  • Lee, Jae-Sung;Jeon, Ik-Hwan;Park, Jang-Sik
    • Journal of Conservation Science
    • /
    • v.27 no.4
    • /
    • pp.421-430
    • /
    • 2011
  • Thermal conditions in practice at the traditional bronze workshop of the Korean Folk Village in Yongin were examined along with the microstructures of some high tin bronze objects made there. Laboratory experiments approximating the conditions of the workshop were also carried out and the results were compared. The operating temperature of the workshop furnace was measured to range from $750^{\circ}C$ to $850^{\circ}C$ while the surface temperature of an object, upon its removal from the furnace for additional thermo-mechanical treatments, was generally in the range of $600^{\circ}C$ to $685^{\circ}C$. This variation in working temperatures was reflected in varying microstructures developed upon quenching. The products of the Folk Village were found to consist of microstructures where the ${\alpha}$ grains of the Cu-Sn system were distributed in the background of different phases including the ${\beta}$-martensite phase, retained ${\gamma}$ phase, ${\alpha}+{\delta}$ eutectoid or their mixtures. This variability, which is also identified in objects made in ancient times as well as in our laboratory experiments, suggests that the actual thermal conditions given during the quenching treatments are much more complicated than is inferred from the temperature measurements. This paper will present detailed accounts of the thermo-mechanical treatments as observed in the high tin bronze workshop of the Korean Folk Village and discuss the evolution of varying microstructures in terms of the substantial variability involved in the implementation of the traditional forged high tin bronze technology of Korea.

A Study on the Cutting Optimal Power Requirements of Fast Growing Trees by Circular Saw (원형톱에 의한 속성수 절단 적정 소요동력 산정에 관한 연구)

  • Choi, Yun Sung;Kim, Dae Hyun;Oh, Jae Heun
    • Journal of Korean Society of Forest Science
    • /
    • v.103 no.3
    • /
    • pp.402-407
    • /
    • 2014
  • In this study, Italy poplar(Populus euramericana) was selected for test specimen to measure cutting power when it harvested. The experiment has been controlled as three levels of feed rate (0.41, 1.25 and 2.5 m/s), sawing speed (800, 1,000 and 1,200 rpm), and the five levels of root collar diameter (50, 70, 90 and 110, 130 mm). The harvested volume after 3 years (root collar diameter 50 mm) was 10.5 tons, which falls short of the target amount of biomass is 20~30 ton/ha. In addition, the biomass amount of diameter 90 and 110 mm which reached the target amount were estimated to be 23.5 and 32.5 ton/ha respectively. As a result of experiment, it was found out that power of 128.2 and 175.8 W are consumed in case of cutting with the feed rate of 0.41m/s and minimum sawing speed (800 rpm) respectively. With the working area of 0.3 ha/h, it is considered to present working capacities of 16.5 and 22.8 ton/h respectively. The power consumed at the feed rate of 1.25 m/s is estimated to be 113.8 and 153.7W respectively and working capacity in a working area of 1 ha/h is estimated to be 23.5 and 32.5 ton/h. The power consumed at the feed rate of 2.5 m/s is estimated to be 119.8 and 166.9 W respectively and working capacity in a working area of 2 ha/h is estimated to be 47.0 and 65.5 ton/ha respectively. Therefore, the power source of harvest machine at the feed rate of 1.25, 2.50 m/s and sawing speed of 800 rpm shall be selected as it can process the target amount of estimated biomass.

An Analytical Study on Research Trends in Journal of Korean Academy of Sensory Integration : From 2003 to 2014 (대한감각통합치료학회지의 연구동향: 2003년부터 2014년까지의 연구를 중심으로)

  • Jung, Nam-Hae;Chang, Moonyoung
    • The Journal of Korean Academy of Sensory Integration
    • /
    • v.13 no.1
    • /
    • pp.45-56
    • /
    • 2015
  • Purpose : This study aimed to critically analyze published research papers in Journal of Korean Academy of Sensory Integration and to investigate the research field and trends. Methods : Types of studies, research trends, levels of evidence, participants, funding sources and research areas were analyzed and described by using 97 selected studies published between 2003 and 2014. Results : Every 5 years, the most frequent type of study was experimental research. The numbers of experimental studies and review studies have been increasing. The most frequent level of evidence was one group non-randomized study, followed by case reports. The highest percentage of participants were children with disability and the most common diagnoses were pervasive developmental disorder, developmental delay and intellectual disabilities. Most of the participants was elementary school students and the most frequent sample size was below 10. The percentage of research grant from Korean Academy of Sensory Integration has been over 50% since 2008. The research areas focusing on the standardized assessments were mostly sensory modulation, interaction and development and the non-standardized assessments were behavior observation and clinical observation. Conclusion : Higher level of studies and comprehensive research methods will be needed. The standardized assessment tools with the high sensibility on sensory integration which developed in the domestic need to be developed. Thus, it will be able to contribute to the evidence based practice in occupational therapy.

Exploration on the Strategies of Organizing Curriculum for Improvement of Major Basic Competencies in the Agricultural High School Students to University by Departments Identical to Their Major (농업계 고등학생들의 동일계 대학 전공기초능력 향상을 위한 교육과정 편성 방안 탐색)

  • Kim, Jin-Gu;Lee, Gun-Nam
    • Journal of vocational education research
    • /
    • v.29 no.3
    • /
    • pp.61-83
    • /
    • 2010
  • The purpose of this study was to analyze high schools' general and special subject required to successfully complete same stream curriculum which is identical to their major from agricultural high school, and to offer basic data on strategies of organizing agricultural high schools' curriculum for improving universities' major basic competencies. Using purposeful sampling technique, the professors of 116 universities professors in 8 agricultural university were analyzed through the survey research. The result was as follows. first, it appeared that for successful completion of major subjects of the same stream university, the basic science subject such as biology and chemistry has high relation with major basic ability, however math and physics are related highly in agricultural machine and agricultural civil engineering department, economics and math are in agricultural produce distribution department. Second, the basic ability such as linguistic competence and foreign language ability are essential to complete major subject. Third, if we look into relation of agriculture and life science industry stream specialized subject with major basic competencies, we can find considerable similarity between major field of university and subject name of specialized high school. Fourth, the main opinion is that basic concept and principle, laws of nature are should be main contents which is able to be practical, however experiment and practice is in food processing department, and academic theory is in biotechnology department.

A Study on the Improvement of a Fleet Management System for Construction Equipment (건설장비 플릿관리 시스템 개선에 관한 연구)

  • Kim, Sung-Keun;Lim, So-Young
    • KSCE Journal of Civil and Environmental Engineering Research
    • /
    • v.37 no.6
    • /
    • pp.1063-1076
    • /
    • 2017
  • To improve the productivity of the earthwork, a fleet management system for construction equipment was suggested in previous studies. But there were some gaps between theory and practice. To overcome this problem, some opinions are gathered form experts and field engineers and four improvements have been proposed and reflected in the system. First, the previous system consists of one hardware module, so it is hard to install it at a control office and construction equipment at the same time. The server module for the office and the mobile module for construction equipment are separately developed. Second, the transportation algorithm that is used in the previous system can generate shortest paths for the earthwork distribution, but embankment areas are not gathered. This situation leads to a decrease in compaction productivity. A modified algorithm for earthwork distribution is suggested. Third, the automated coordinate transformation is performed to show the position of construction equipment on the 3D terrain in real-time. Fourth, construction equipment groups should be formed in the initial stage of earthwork and the number of equipment of each groups should be changed by operation status and site environment. But this functions did not work properly in the previous system. This problem is corrected in the proposed system. The improvements can make the proposed system much more realistic one and can leads to an increase in the productivity of earthwork operations.

Development of a Measuring Instrument for the Coefficient of Luminous Intensity of Retro-Reflection of Miniature Telecentric Cameras (소형 텔레센트릭 카메라 광학계의 재귀반사 측정 방법 연구 및 측정 장치 개발)

  • Yeo, TaeWoon;Karasik, V.E.;Kim, Young Il
    • Korean Journal of Optics and Photonics
    • /
    • v.25 no.6
    • /
    • pp.334-339
    • /
    • 2014
  • In this paper, the optical properties of a miniature telecentric camera are studied analytically and experimentally. By means of optical properties, the luminous intensity of retro-reflection of a miniature telecentric optical system is investigated. First, from a simulation the theoretical value of the coefficient of luminous intensity of retro-reflection of a miniature telecentric system is estimated. Second, a miniature telecentric camera device is designed, and the value of the coefficient of luminous intensity of retro-reflection of the actual device is measured through experiment. From simulation and experiment, we found that both the estimated and observed values of the coefficient of luminous intensity of retro-reflection range from 0.002 to $0.03m^2/sr$ (P384200CPH: $0.0042-0.018m^2/sr$, P285200CPH: $0.0045-0.0297m^2/sr$, P321450S: $0.0021-0.00963m^2/sr$) at 1.4 to 4.9 arcminute. The results prove the significance of the mechanisms used to design the miniature telecentric camera, and the experimental method. Accordingly, with these significant results, this study contributes to the development of theory and practice in optical engineering science.