• Title/Summary/Keyword: 수학일지

Search Result 27,826, Processing Time 0.053 seconds

A study of the Implications of French vocabularies and the de-locality in LEE Sang's Poems (이상(李箱)의 시 작품에 구사되는 프랑스어와 탈 지방성)

  • Lee, Byung-soo
    • Cross-Cultural Studies
    • /
    • v.53
    • /
    • pp.1-24
    • /
    • 2018
  • This following research is a study on the use of French and de-locality in the modern Korean poet Lee Sang's poetry (1910-1937). His hometown was Kyung Sung, Seoul. He mainly wrote his works in Korean, Chinese character, and Japanese, using the language of education and his native language at that time. So then, what was the spirit that he wanted to embody through use of French words? By using words like "ESQUISSE", "AMOUREUSE", Sang's French was not a one-time use of foreign words intended to amuse, but to him the words were as meticulously woven as his intentions. French words were harmonized with other non-poetic symbols such as "${\Box}$, ${\triangle}$, ${\nabla}$", and described as a type of typographical hieroglyphics. Instead of his mother-tongue language, French was applied as a surrealistic vocabulary that implemented the moral of infinite freedom and imagination, and expressed something new or extrasensory. Subsequently, the de-localized French (words) in his poetry can be seen as poetic words to implement a "new spirit", proposed by western avant-garde artists. Analysis of French in his poetry, showed a sense of yearning for the scientific civilization, calling for his sense of defeat and escape from the colonized inferior native land. Most of all, comparing his pursuit of western civilization and avant-garde art to French used in his poetry, is regarded as world-oriented poetry intended to implement the new tendency of the "the locomotive of modernity," transcending the territory of the native country.

Identification of Foreign Objects in Soybeans Using Near-infrared Spectroscopy (근적외선 분광법을 이용한 콩과 이물질의 판별)

  • Lim, Jong-Guk;Kang, Sukwon;Lee, Kangjin;Mo, Changyeon;Son, Jaeyong
    • Food Engineering Progress
    • /
    • v.15 no.2
    • /
    • pp.136-142
    • /
    • 2011
  • The objective of this research was to classify intact soybeans and foreign objects using near-infrared (NIR) spectroscopy. Intact soybeans and foreign objects were scanned using a NIR spectrometer equipped with scanning monochromator. NIR spectra of intact soybeans and foreign objects in the wavelength range from 900 to 1800 nm were collected. The classification of intact soybeans and foreign objects were conducted by using partial least-square discriminant analysis (PLS-DA) and soft independent modelling of class analogy (SIMCA) multivariate methods. Various types of data pretreatments were tested to develop the classification models. Intact soybeans and foreign objects were successfully classified by the PLS-DA prediction model with mean normalization pretreatment. These results showed the potential of NIR spectroscopy combined with multivariate analysis as a method for classifying intact soybeans and foreign objects.

Analysis of influence of parameter error for extended EMF based sensorless control and flux based sensorless control of PM synchronous motor (영구자석 동기전동기의 확장 역기전력 기반 센서리스 제어와 자속기반 센서리스 제어의 파라미터 오차의 영향 분석)

  • Park, Wan-Seo;Cho, Kwan-Yuhl;Kim, Hag-Wone
    • Journal of the Korea Academia-Industrial cooperation Society
    • /
    • v.20 no.3
    • /
    • pp.8-15
    • /
    • 2019
  • The PM synchronous motor drives with vector control have been applied to wide fields of industry applications due to its high efficiency. The rotor position information for vector control of a PM synchronous motor is detected from the rotor position sensors or rotor position estimators. The sensorless control based on the mathematical model of PM synchronous motor is generally used and it can be classified into back EMF -based sensorless control and magnet flux-based sensorless control. The rotor position estimating performance of the back EMF-based sensorless control is deteriorated at low speeds since the magnitude of back EMF is proportional to the motor speed. The magnitude of the magnet flux for estimating rotor position in the flux-based sensorless control is independent on the motor speed so that the estimating performance is excellent for wide speed ranges. However, the estimation performance of the model-based sensorless control may be influenced by the motor parameter variation since the rotor position estimator uses the mathematical model of the PM synchronous motor. In this paper, the rotor position estimation performance for the back EMF based- and flux-based sensorless controls is analyzed theoretically and is compared through the simulation and experiment when the motor parameters including stator resistance and inductance are varied.

Analysis of Radiation Dose Enhancement for Spread Out Bragg-peak of Proton (확산된 피크의 양성자에서 선량 증강 현상에 대한 분석)

  • Hwang, Chulhwan;Kim, JungHoon
    • Journal of the Korean Society of Radiology
    • /
    • v.13 no.2
    • /
    • pp.253-260
    • /
    • 2019
  • Radiation dose enhancement is a method of increasing the cross section of interaction, thus increasing the deposited dose. This can contribute to linear energy transfer, LET and relative biological effectiveness, RBE. Previous studies on dose enhancement have been mainly focused on X, ${\gamma}-rays$, but in this study, the dose enhancement was analyzed for proton using Monte Carlo simulation using MCNP6. Based on the mathematical modeling method, energy spectrum and relative intensity of spread out Bragg-peak were calculated, and evaluated dose enhancement factor and dose distribution of dose enhancement material, such as aurum and gadolinium. Dose enhancement factor of 1.085-1.120 folds in aurum, 1.047-1.091 folds in gadolinium was shown. In addition, it showed a decrease of 95% modulation range and practical range. This may lead to an uncertain dose in the tumor tissue as well as dose enhancement. Therefore, it is necessary to make appropriate corrections for spread out Bragg-peak and practical range from mass stopping power. It is expected that Monte Carlo simulation for dose enhancement will be used as basic data for in-vivo and in-vitro experiments.

An Analysis of Domestic Research Trend on Walking and Positioning : Focusing on Comparative Analysis between the Visually Impaired and the Non-disabled (보행 및 위치에 관한 국내 연구 동향 분석 : 시각장애인과 비장애인의 비교 분석을 중심으로)

  • Bae, Sun-Young
    • The Journal of the Korea Contents Association
    • /
    • v.18 no.11
    • /
    • pp.611-622
    • /
    • 2018
  • In this study, I was to investigate the trends in research on walking and positioning in Korea and to compare the results of researches on the Visually Impaired and the Non-disabled. I selected 113 papers in order to know the current status of the study for the visually impaired and to suggest future research directions. This study analyzed the general features (publication year, academic journals, number of authors, keywords, research methods, research types, implementation methods, research support, references) and research themes and contents of domestic research on walking and positioning. As a result, there was no an upward trend in number of publications by the Visually Impaired compared to the Non-disabled. In addition, in the case of the non-disabled, Research topics, types of research, implementation include various attempts of location-related technologies, and system development, improvement, stabilization, and accuracy, whereas in the case of the visually impaired, there were focused on development of systems, portable or attachable devices that reflect the characteristics of the visually impaired. There were not many studies on system improvement. Research support also showed that the non-disabled received various research support. Therefore, I suggested the need to continuously develop and improve the research, to diversify research topics and research types, to expand the research scope, to improvement feasibility for the visually impaired.

The Research of Layout Optimization for LNG Liquefaction Plant to Save the Capital Expenditures (LNG 액화 플랜트 배치 최적화를 통한 투자비 절감에 관한 연구)

  • Yang, Jin Seok;Lee, Chang Jun
    • Korean Chemical Engineering Research
    • /
    • v.57 no.1
    • /
    • pp.51-57
    • /
    • 2019
  • A plant layout problem has a large impact on the overall construction cost of a plant. When determining a plant layout, various constraints associating with safety, environment, sufficient maintenance area, passages for workers, etc have to be considered together. In general plant layout problems, the main goal is to minimize the length of piping connecting equipments as satisfying various constraints. Since the process may suffer from the heat and friction loss, the piping length between equipments should be shorter. This problem can be represented by the mathematical formulation and the optimal solutions can be investigated by an optimization solver. General researches have overlooked many constraints such as maintenance spaces and safety distances between equipments. And, previous researches have tested benchmark processes. What the lack of general researches is that there is no realistic comparison. In this study, the plant layout of a real industrial C3MR (Propane precooling Mixed Refrigerant) process is studied. A MILP (Mixed Integer Linear Programming) including various constraints is developed. To avoid the violation of constraints, penalty functions are introduced. However, conventional optimization solvers handling the derivatives of an objective functions can not solve this problem due to the complexities of equations. Therefore, the PSO (Particle Swarm Optimization), which investigate an optimal solutions without differential equations, is selected to solve this problem. The results show that a proposed method contributes to saving the capital expenditures.

Pansori master Bak songhui's life and her activities (박송희 명창의 삶과 예술 활동)

  • Chae, Soo-jung
    • (The) Research of the performance art and culture
    • /
    • no.36
    • /
    • pp.255-287
    • /
    • 2018
  • This article deals with one of the pansori master's life and activities. Bak Songhui(1927~2017), who was the holder of National Intangible Cultural Asset No. 5 for pansori Heungboga. She had played a significant role through the modern history of pansori genre including Yeoseong Gukkeuk(Korean classical opera by women) and Changgeuk(Korean traditional opera in pansori style) as well as original pansori itself. In the article, the early stage of her learnings and the way she got involved to pansori from Gwonbeon period are offered, and the activities by group, solo recitals, and educational activity lists are also provided. Bak Songhui began to learn pansori, Geommu(dance), Seungmu(dance), Gayageum, Yanggeum, and Gagok genres at her age of 13 in Gwangju. She fulfilled 5 years of study in Gwangju Gwonbeon, and entered to a Hyeomnyulsa-travelling theater company, led by Gim Yeonsu at her age around 19. Later, Bak used to be an actress in Yeoseong Gugak Donghohoe(Female Korean music fans' club) led by Gim sohui as well as in Haennim Gukkeukdan, and Saehan Gukkeukdan at around her age of 30. She took the main actress' role in several performances. And thanks to her effort, the Yeoseong Gukkeuk can be one of the representative genre in history. As she entered to the National Changgeuk company, her brilliant talents worked well by leading the company's big hit with her talents of taking many different characters, devotions, and know-hows from her experience. After her 70s, she kept the pansori go on its right way to pass down. She unfolded pansori performances as well as her own students' public presentations, recordings, TV and radio broadcasting activities as the holder of National Intangible Cultural Asset. The activities that Bak Songhui showed us can become another chance to make her a great master of pansori, especially in Dongpyeonje style.

Using Topology Optimization, Light Weight Design of Vehicle Mounted Voltage Converter for Impact Loading (위상 최적화 기법을 이용한 충격하중에 대한 차량 탑재형 전력변환장치의 마운트 경량화 설계)

  • Ko, Dong-Shin;Lee, Hyun-Kyung;Hur, Deog-Jae
    • Journal of the Computational Structural Engineering Institute of Korea
    • /
    • v.31 no.6
    • /
    • pp.353-358
    • /
    • 2018
  • In this study, it is describe to an optimization analysis process for the weight reduction of the voltage converter in the electric vehicle charging systems. The optimization design is a technique that finds the optimal material distribution under a given material quantity constraint by combining the design sensitivity with the material properties and the mathematical optimization. Among the topology optimization, a lightweight design is performed by a solid isotropic material with penalization with simple formula and well-convergence. The lightweight design consists of three steps. As a first step, a finite element model for the basic design of the on-board voltage converter was constructed and static analysis was performed on the load. In the second step, the optimum shape is obtained for the lightweight by performing the topology optimization using the solid isotropic material with penalization applying the stiffness coefficient of the isotropic material to the static analysis result. As a final step, impact analysis was performed by applying a half-sinusoidal pulse shape impact load which satisfies the impact test standard of the vehicle-mounted part with respect to the optimum shape. In the topology optimization, the design domain was defined as the mounting bracket area, and the design technology was finally achieved by optimizing the mounting bracket to achieve a weight reduction of 20% over the basic design.

Development for Prediction Model of Disaster Risk through Try and Error Method : Storm Surge (시행 착오법을 활용한 재난 위험도 예측모델 개발 : 폭풍해일)

  • Kim, Dong Hyun;Yoo, HyungJu;Jeong, SeokIl;Lee, Seung Oh
    • Journal of Korean Society of Disaster and Security
    • /
    • v.11 no.2
    • /
    • pp.37-43
    • /
    • 2018
  • The storm surge is caused by an typhoons and it is not easy to predict the location, strength, route of the storm. Therefore, research using a scenario for storms occurrence has been conducted. In Korea, hazard maps for various scenarios were produced using the storm surge numerical simulation. Such a method has a disadvantage in that it is difficult to predict when other scenario occurs, and it is difficult to cope with in real time because the simulation time is long. In order to compensate for this, we developed a method to predict the storm surge damage by using research database. The risk grade prediction for the storm surge was performed predominantly in the study area of the East coast. In order to estimate the equation, COMSOL developed by COMSOL AB Corporation was utilized. Using some assumptions and limitations, the form of the basic equation was derived. the constants and coefficients in the equation were estimated by the trial and error method. Compared with the results, the spatial distribution of risk grade was similar except for the upper part of the map. In the case of the upper part of the map, it was shown that the resistance coefficient, k was calculated due to absence of elevation data. The SIND model is a method for real-time disaster prediction model and it is expected that it will be able to respond quickly to disasters caused by abnormal weather.

An Analytical Model Proposal Considering Different Surface Type of Bond Behavior between GFRP Rebar and Concrete (GFRP 보강근의 외피형상을 고려한 부착 해석모델 제안)

  • Park, Ji-Sun;Song, Tae-Hyeob;Lee, Jung-Yoon
    • Journal of the Korea institute for structural maintenance and inspection
    • /
    • v.23 no.3
    • /
    • pp.150-159
    • /
    • 2019
  • The bond analysis model equation was proposed through the regression analysis of the experimental values of bond behavior for each rebar. In order to verify the appropriateness of the bond analysis model equation, the bond behaviors calculated by the proposed bond analysis model, BPE model and CMR model were compared with experimental values. The proposed bond model showed the closest behavior to the experimental values when compared to other analysis models. The former models can not consider the different properties of GFRP rebar according to composed materials, mixing and manufacturing method and the latter has limitation to express the relationships between bond behavior because of derived formula by numerical analysis. This study proposed the analytical model different considering bond mechanism according to surface type. In order to verity the appropriateness of the bond analytical model, the bond behaviors calculated by the proposed bond analytical model, BPE model and CMR model were compared with experimental values. The proposed bond model showed the closest behavior to the experimental values when compared to other analysis models.