• Title/Summary/Keyword: 수학관

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Mathematical Modeling and Simulation on the Control of Heart rate by Baroreceptor Control System in the Cardiovascular System (심혈관 시스템의 압수용체에 의한 심박동 제어의 수학적 모델링 및 시뮬레이션)

  • Choi, B.C.;Lee, S.J.;Eom, S.H.;Nam, G.K.;Lee, Y.W.;Jun, K.R.
    • Proceedings of the KOSOMBE Conference
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    • v.1996 no.11
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    • pp.80-85
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    • 1996
  • The various function of the cardiovascular system(CVS) and the dynamic characteristics on each part of human body can be acquired in the electric analog circuit model. According to the performed outcome by other researchers, viscos resistance, flow inertia, and vascular compliance in the CVS are analogous to resister, inductor, and capacitor in electric circuit, so the CVS models were represented by the electric circuit models. these approaches were to propose the suitable models interest part of body and to simulate the various characteristics on the CVS. In this paper, the electric circuit model considering the characteristics of morphologic structure is represented, the parameter values of model is sotted up, and the dynamic characteristics of the the CVS is simulated using VisSim, one of the simulation tools. The observed simulation results are similar to the cardiovascular functions of nomal adults who have no heart failure. Besides, the simulation is operated to observe the pathophysiological abnomal symptoms(for example, bleeding within a certain period). The controller by baroreceptor, which is one of controllers to control the CVS, is appended in the model. and the dynamic response characteristics and the procedure to return normal state is observed in simulation when the bleeding last within a certain period.

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A Study on Building a Cyber Attack Database using Open Source Intelligence (OSINT) (공개출처정보를 활용한 사이버공격 데이터베이스 구축방안 연구)

  • Shin, Kyuyong;Yoo, Jincheol;Han, Changhee;Kim, Kyoung Min;Kang, Sungrok;Moon, Minam;Lee, Jongkwan
    • Convergence Security Journal
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    • v.19 no.2
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    • pp.113-121
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    • 2019
  • With the development of the Internet and Information Communication Technology, there has been an increase in the amount of Open Source Intelligence(OSINT). OSINT can be highly effective, if well refined and utilized. Recently, it has been assumed that almost 95% of all information comes from public sources and the utilization of open sources has sharply increased. The ISVG and START programs, for example, collect information about open sources related to terrorism or crime, effectively used to detect terrorists and prevent crime. The open source information related to the cyber attacks is, however, quite different from that in terrorism (or crime) in that it is difficult to clearly identify the attacker, the purpose of attack, and the range of damage. In addition, the data itself of cyber attacks is relatively unstructured. So, a totally new approach is required to establish and utilize an OSINT database for cyber attacks, which is proposed in this paper.

A Model for Liquid Circulation Velocity in Airlift Reactors (공기부양반응기 내에서의 액체순환속도를 위한 모델)

  • Keun Ho Choi
    • Korean Chemical Engineering Research
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    • v.61 no.3
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    • pp.446-455
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    • 2023
  • A mathematical model for predicting the liquid circulation velocity in an airlift reactor was developed based on the mechanical energy balance of the fluid circulation loop. The model considered the energy loss due to a 90° turn, the energy loss due to friction, and the energy loss due to the change in cross-sectional area at each part of the reactor. The model that separately considered the loss coefficients related to friction, direction change, and cross-sectional area change was able to predict the liquid circulation velocity better than the previous model using lumped parameters. The liquid circulation velocity was measured by the tracer pulse method. Most of our experimental results obtained in external-loop airlift reactors, which had the top and bottom connecting pipes, as well as other investigators' results obtained in various types of airlift reactors, were well predicted by the developed model with an error within 20%. Useful empirical equations for the loss coefficient related to the 90° turn of the circulating fluid were obtained in external and internal-loop airlift reactors and used to predict the liquid circulation velocity.

Prediction of Land-Use Change based on Urban Growth Scenario in South Korea using CLUE-s Model (도시성장 시나리오와 CLUE-s 모형을 이용한 우리나라의 토지이용 변화 예측)

  • LEE, Yong-Gwan;CHO, Young-Hyun;KIM, Seong-Joon
    • Journal of the Korean Association of Geographic Information Studies
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    • v.19 no.3
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    • pp.75-88
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    • 2016
  • In this study, we used the CLUE-s model to predict the future land-use change based on the urban growth scenario in South Korea. The land-use maps of six classes (water, urban, rice paddy, upland crop, forest, and grass) for the year 2008 were obtained from the Ministry of Environment (MOE), and the land-use data for 5-year intervals between 1980 and 2010 were obtained from the Water Resources Management Information System (WAMIS), South Korea. For predicting the future land-use change, the MOE environmental conservation value assessment map (ECVAM) was considered for identifying the development-restricted areas, and various driving factors as location characteristics were prepared for the model. The predicted results were verified by comparing them with the land-use statistics of urban areas in each province for the year 2008. The prediction error rates were 9.47% in Gyeonggi, 9.96% in Gangwon, 10.63% in Chungbuk, 7.53% in Chungnam, 9.48% in Jeonbuk, 6.92% in Jeonnam, 2.50% in Gyeongbuk, and 8.09% in Gyeongnam. The sources of error might come from the gaps between the development of political decisions in reality with spatio-temporal variation and the mathematical model for urban growth rate in CLUE-s model for future scenarios. Based on the land-use scenario in 2008, the land-use predictions for the year 2100 showed that the urban area increased by 28.24%, and the rice paddy, upland crop, and forest areas decreased by 8.27, 6.72, and 1.66%, respectively, in South Korea.

Model on the Contact Lens Movement from Eye-lid Blinking (순목 작용에 의한 콘택트 렌즈의 운동 모델)

  • Kim, Daesoo
    • Journal of Korean Ophthalmic Optics Society
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    • v.9 no.1
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    • pp.145-159
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    • 2004
  • A mathematical model and its computer solution program were proposed to analyze the motion of contact lenses which are being subject to lid-blinking. The equation was derived by incorporating an acceleration induced lid's force exerting on the contact lens, the viscous damping resistance in the tear layer beneath the lens and the sliding frictional force between the lid and the contact lens surface into the formulation of differential equation describing the vibration. The model predicts the time-dependent displacement from the equilibrium postion during/after the blinking. During the blinking, as the time for the completion of one cycle of blinking decreases the off-the-equilibrium displacement of contact lens increases while the decrease of diameter in the contact cause the opposite effect. It is found that lid pressure exerting on the lens cause an insignificant lens displacement from the equilibrium position. After blinking the frequency of damped oscillation of contact lens decreases as the diameter of lens increases, due to the incresed surface while the reduced blinking time does not cause a significant frequency change. This is because that driving force for the contact lens movement posterior to blinking is the capillary-induced force not the lid force.

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A Study on Construction of Multiplication Knowledge with Low Reasoning Ability (추론 능력이 열등한 초등학교 2학년 학생의 곱셈 지식 구성 능력에 관한 연구)

  • Lee, So-Min;Kim, Jin-Ho
    • Journal of the Korean School Mathematics Society
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    • v.12 no.1
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    • pp.47-70
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    • 2009
  • The purpose of this research was to confirm one of constructivists' assumptions that even children 조o are with low reasoning ability can make reflective abstracting ability and cognitive structures by this ability can make generation ability of new knowledge by themselves. To investigate the assumption, learner-centered instruction were implemented to 2nd grade classroom located in Suseong Gu, DaeGu City and with lesson plans which initially were developed by Burns and corrected by the researchers. Recordings videoed using 2 video cameras, observations, instructions, children's activity worksheets, instruction journals were analyzed using multiple tests for qualitative analysis. Some conclusions are drawn from the results. First, even children with low reasoning ability can construct mathematical knowledge on multiplication in their own. ways, Thus, teachers should not compel them to learn a learning lesson's goals which is demanded in traditional instruction, with having belief they have reasoning ability. Second, teachers need to have the perspectives of respects out of each child in their classroom and provide some materials which can provoke children's cognitive conflict and promote thinking with the recognition of effectiveness of learner-centered instruction. Third, students try to develop their ability of reflective and therefore establish cognitive structures such as webs, not isolated and fragmental ones.

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Optimal temperature for Pleurotus eryngii cultivation (큰느타리(새송이)버섯 최적 생육온도 조건)

  • Kim, Sun-Young;Kim, Min-Keun;Im, Chak-Han;Kim, Kyung-Hee;Park, Ki-Kwan;Song, Won-Du;Ryu, Jae-San
    • Journal of Mushroom
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    • v.10 no.4
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    • pp.160-166
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    • 2012
  • The effects of fixed and variable temperatures on fruiting body formation and characters of mushrooms were investigated with normal and thinning treatment plots. In fixed temperature, as temperature was lower, period of harvest was longer as well as days for pinheading in the both of normal and thinning plots. Harvest rate were 91.0, 90.3, and 95.8% at $13^{\circ}C$, $17^{\circ}C$, and $15^{\circ}C$. In the thinning plot, qualities of mushrooms were 7.5, 8.1, and 7.7, and yields were 86.0, 105.9, 104.0g at 13, 15, and $17^{\circ}C$ respectively. In variable temperature with a variable temperature plot, condition II($17^{\circ}C$ for pin-heading(before reverting, 7-8 days)${\rightarrow}16^{\circ}C$ for extending primodia(before thinning, 4-5 days)${\rightarrow}15^{\circ}C$ for extending (after thinning)) was the best for yield which was better than other conditions by 17.4% and 4.0% and quality of mushroom was highest 8.1 among all conditions.

A Improved Case of Post Cerebral Infarction Dizziness and Gait Discomfort after Treated with Korean Medicine Treatment and Vestibular Rehabilitation Practice (한의복합치료와 전정재활운동을 병행하여 뇌졸중 후 어지러움과 보행불안 증상이 개선된 증례 보고)

  • Chu, Hongmin;Lim, Hyeon-Seo;Kim, Kwangho;Lee, Young-Ung;Park, Kyungtae;Jang, Jongwon;Ryu, Ho-sun;Kim, Su-hak;Kim, Cheol-hyun;Lee, Sangkwan;Sung, Kang-keyng
    • Journal of Korean Medicine Rehabilitation
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    • v.30 no.4
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    • pp.179-186
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    • 2020
  • The aim of this study was to report the effect of Korean medicine treatments and vestibular rehabilitation practice on an stroke patient with dizziness. The patient received Korean medicine treatments, such as acupuncture and herbal medication, and vestibular rehabilitation practice. The effects of treatments were assessed with the Korean dizziness handicap inventory, Korean activities-specific balance confidence scale, Korean vestibular disorders activities of daily living scale. Researchers conducted gait analysis for evaluation patient's gait disturbance's improvement during treatments. The intensity of dizziness were significantly reduced after the complete treatment. After treatment with traditional Korean medicine and vestibular rehabilitation practice, the patient showed significant improvements in symptoms and gait parameters. This case proved that combined therapy of Korean medicine treatment and vestibular rehabilitation practice can be useful for stroke patients who suffered from dizziness. however, studies of larger populations are required in the future.

A Study on the Characteristics of Garden Architecture in Italian Renaissance Villa Lante (이탈리아 르네상스 빌라 란테의 정원건축적 특성)

  • Choi, Jong-Hee
    • Journal of the Korean Institute of Traditional Landscape Architecture
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    • v.29 no.2
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    • pp.90-98
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    • 2011
  • This study aims to discuss the characteristics of garden architecture in Italian Renaissance Villa Lante that was constructed by the cardinal in Bagnaia at 16th century through actual survey and analysis of the garden's elements. To do this, it was studied in two ways: Analysis of the present conditions and review historical documents. The results are as follows. First, the buildings, the gardens and the surrounding landscapes are visually connected each other in relations between the topography and the surrounding landscapes. Second, the spatial composition accepted Neoplatonic law of multiple proportions and was influenced by ancient myth and "Liber ruralium commodorum" of Pietro de Crescenzi(1305). Third, the garden's elements consist of plants, buildings and items. In plants, the upper plants are fir tree, cypress and pine tree and the lower plants are english holly, box tree and sweet oleander. The buildings are casino, loggia and terrace. The items are pot, sundial, chair, viewing platform and fountain. The result of this study, the political and social, technical phenomena which constitute construction pattern affected the locational property and the spatial organization of the neighbor on Villa Lante.

The life and academic world of 鶴皐(Hakgo) 金履萬(Kim Ee-man) (학고(鶴皐) 김이만(金履萬)의 생애와 학문세계)

  • Kim, Jong-soo
    • The Journal of Korean Philosophical History
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    • no.37
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    • pp.97-134
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    • 2013
  • Kim Ee-man was born and grew up in Jecheon (堤川). As a government officer and a Confucian scholar belonging to Namin School, Kim Ee-man was active in the early and middle of 18th century. Kim Ee-man composed good poems since he was a child. In addition to being a good poet, Kim Ee-man later became a model government officer, who had thorough awareness on serving citizens (爲民). When he was a governor in Yangsan (梁山) county, he built an embankment for farmers by out of his own salary. The academic world of Kim Ee-man faithfully succeeded the basis of Toegyehak (退溪學) and he took Sohak (小學) as important. The reason of Kim Ee-man having established a practical guideline in the form of inscription and proverbs was also directly related to the issue of moral practice. Kim Ee-man also received the influence of ancient classic study from his teacher Lee Seo-woo (李瑞雨) and took Yookgyeong (六經, Six Classics in China) important in practice. Kim Ee-man started the study on Joojahak (朱子學, the doctrines of Chu-tzu) in later years. He became more thorough in being a public figure while reinforcing effort on differentiating the principle of heaven (天理) and human desire (人欲).