• Title/Summary/Keyword: 책거리

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A Study on the Transmitter Design for Transmitting Output Power Enhancement of Active Magnetic Sensor (능동형 자기센서의 송신출력 향상을 위한 송신기 설계에 관한 연구)

  • Chung, Hyun-Ju;Yang, Chang-Seob;Jeon, Jae-Jin
    • Journal of the Korean Magnetics Society
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    • v.23 no.5
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    • pp.159-165
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    • 2013
  • A active magnetic sensor has been widely used in the underwater guided weapon system because it is able to detect a target accurately in close range, but the target doesn't have any good countermeasure to overcome the threat from the active magnetic sensor. Recently, in order to increase the damage area of target by shock wave with explosion of the underwater weapon system and to detect small target, the maximum target detection range of the active magnetic sensor needs to be increased. One method for improving maximum target detection range is to improve output power from transmitter through demagnetization factor minimization of a transmitting core. Thus, in this paper, we describe the study results on the transmitter core shape design to enhance output power of the active magnetic sensor.

A Fast Encoding Algorithm for Image Vector Quantization Based on Prior Test of Multiple Features (복수 특징의 사전 검사에 의한 영상 벡터양자화의 고속 부호화 기법)

  • Ryu Chul-hyung;Ra Sung-woong
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.30 no.12C
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    • pp.1231-1238
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    • 2005
  • This paper presents a new fast encoding algorithm for image vector quantization that incorporates the partial distances of multiple features with a multidimensional look-up table (LUT). Although the methods which were proposed earlier use the multiple features, they handles the multiple features step by step in terms of searching order and calculating process. On the other hand, the proposed algorithm utilizes these features simultaneously with the LUT. This paper completely describes how to build the LUT with considering the boundary effect for feasible memory cost and how to terminate the current search by utilizing partial distances of the LUT Simulation results confirm the effectiveness of the proposed algorithm. When the codebook size is 256, the computational complexity of the proposed algorithm can be reduced by up to the $70\%$ of the operations required by the recently proposed alternatives such as the ordered Hadamard transform partial distance search (OHTPDS), the modified $L_2-norm$ pyramid ($M-L_2NP$), etc. With feasible preprocessing time and memory cost, the proposed algorithm reduces the computational complexity to below the $2.2\%$ of those required for the exhaustive full search (EFS) algorithm while preserving the same encoding quality as that of the EFS algorithm.

The Role of Proximity in the Internalization of Corporate Social Responsibility: Lessons from the U.S Corporations' Participation in the B-Corp Movement (기업의 사회적 책임 확산과정에서의 근접성의 역할: 미국 기업들의 비콥 무브먼트 참여과정을 중심으로)

  • Lee, Jiun;Lee, Yeowon;Kim, Sang-Joon
    • Korean small business review
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    • v.43 no.2
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    • pp.31-57
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    • 2021
  • This study delves into a question as to how the concept of corporate social responsibility (CSR) is internalized across corporations. CSR internalization refers to the process where a corporation incorporates CSR practices into its business practices. Drawn from the institutionalization process of knowledge adoption under environmental pressure, we pay attention to the roles of proximity, defined as the distance between environmental characteristics and organizational characteristics of corporations. And we argue that the extent to which a given firm is situated in the environment knowledgeable will make the firm likely to adopt CSR practices. To test this idea, we figure out when and how corporations participate in the B-Corporation Movement in the U.S., through the lens of proximity. Specifically, we subdivide proximity into geographical proximity, organizational proximity, and overlapped proximity and examine whether proximity can increase the likelihood of adopting CSR practices. With a sample of 536 start-ups which had participated in the B-Corporation Movement between 2007 and 2017, we find that the three types of proximity consistently increase the likelihood of becoming a certified B-Corp. This suggests that a corporation is highly likely to accept the concept of CSR under external pressures, along with its intrinsic motivation, which provide theoretical and practical implications on CSR internalization.

FEM Analysis on the Damage for the Cable of Cabled-suspension Bridges by Fire (화재에 의한 사장교 케이블의 유한요소 해석)

  • Song, Young-Sun;Lee, Byung-Sik;Kim, Hyeong-Joo;Park, Weon-Tae
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.9 no.1
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    • pp.136-142
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    • 2008
  • Recently, cabled-suspension bridges and suspension bridge have been increasingly built in korea. But such structures were often damaged by fire due to car collison. In this study, the cabled-suspension bridges constructed under the kind of the project of national road aggrandizement are modeled using Solid Works 2007. The COSMOS FloWorks 2007 software are used for Heat Transfer Analysis and Thermal Stress Analysis. The safety of wire, HDPE pipe and stainless steel pipe are investigated. The major variables for the analysis are the temperature of the heat source, the distance between the fire-proof bulk head and the heat source, wind velocity, and the height of the end of Stainless steel pipe.

Front-End Processing for Speech Recognition in the Telephone Network (전화망에서의 음성인식을 위한 전처리 연구)

  • Jun, Won-Suk;Shin, Won-Ho;Yang, Tae-Young;Kim, Weon-Goo;Youn, Dae-Hee
    • The Journal of the Acoustical Society of Korea
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    • v.16 no.4
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    • pp.57-63
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    • 1997
  • In this paper, we study the efficient feature vector extraction method and front-end processing to improve the performance of the speech recognition system using KT(Korea Telecommunication) database collected through various telephone channels. First of all, we compare the recognition performances of the feature vectors known to be robust to noise and environmental variation and verify the performance enhancement of the recognition system using weighted cepstral distance measure methods. The experiment result shows that the recognition rate is increasedby using both PLP(Perceptual Linear Prediction) and MFCC(Mel Frequency Cepstral Coefficient) in comparison with LPC cepstrum used in KT recognition system. In cepstral distance measure, the weighted cepstral distance measure functions such as RPS(Root Power Sums) and BPL(Band-Pass Lifter) help the recognition enhancement. The application of the spectral subtraction method decrease the recognition rate because of the effect of distortion. However, RASTA(RelAtive SpecTrAl) processing, CMS(Cepstral Mean Subtraction) and SBR(Signal Bias Removal) enhance the recognition performance. Especially, the CMS method is simple but shows high recognition enhancement. Finally, the performances of the modified methods for the real-time implementation of CMS are compared and the improved method is suggested to prevent the performance degradation.

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A Study on Technology Transfer in IT Industry (IT 산업계의 기술이전에 관한 연구)

  • Sung, Tae-Kyung
    • Management & Information Systems Review
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    • v.28 no.3
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    • pp.45-68
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    • 2009
  • The Korean government is actively pursuing an ambitious IT strategy to establish Korea as one of the leaders in the world IT market. To implement the strategy, successful technology transfer from research institutions to market should be achieved. Comprehensive literature identifies sixteen variables affecting the process and results of technology transfer. The research results in four key factors in technology transfer: Communication, Distance, Equivocality, and Motivation. Communication refers to the degree to which a medium is able to efficiently and accurately conveys task-relevant information and media while distance involves both physical and cultural proximity. Equivocality refers to the degree of concreteness of technology to be transferred while motivation involves incentives for and the recognition of the importance of technology transfer activities. Further analysis shows that there are four distinctive clusters and they show very contrasting characteristics in terms of four key factors. The careful mapping of the four clusters on the four key factors show very informative technology transfer patterns, the Technology Transfer Grid.

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An Analysis And Criticism on Mathematics Terminologies Used in Elementary School Mathematics: Focused on Some Examples (우리나라 초등학교 수학용어의 분석과 비판: 몇 가지 예를 중심으로)

  • Park, Kyo Sik
    • Journal of Elementary Mathematics Education in Korea
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    • v.17 no.1
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    • pp.1-17
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    • 2013
  • In this paper, firstly, 'value', 'vertices', 'height' are discussed, which are used in the multiple contexts. Then 'sketch', 'mental math', 'zero point oneth place/zero point zero oneth place/zero point zereo zero oneth place', 'number of place', 'natural number part/decimal part' are discussed, which are not used consistently. Finally, middle school mathematics terms 'distance', 'number line', 'the value of the expression' are discussed which are used in elementary school mathematics textbooks/workbooks. From these discussions, the following four suggestions are proposed as conclusions. First, as a mathematical term 'value' and 'distance' should be emphasized. As 'distance' is a middle school term, there is a need to consider the 'height' as 'the length of the line segment' instead of 'distance'. Second, 'number of place' which can be replaced with other suitable term, 'the value of the expression' including 'value of $20{\times}4$', 'natural number part/decimal part', 'vertex of pyramid/vertex of cone', 'mental math' should not be used. Third, there is a need to consider the use of 'mixed decimal' and 'proper decimal'. In addition, there is a need to expand the use of 'sketch'. Fourth, there is a need to consider the confirmation of 'number line' as an elementary school mathematics term. In addition, there is a need to consider to specify that 'decimal first place', 'decimal second place', 'decimal third place' can be used equivalently with 'zero point oneth place', 'zero point zero oneth place', 'zero point zereo zero oneth place' respectively.

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A Study on Intensive Quantities Handled in Korean Elementary Math Textbooks and Workbooks (우리나라 초등학교 수학 교과서 및 익힘책에서 취급하는 내포량에 관한 연구)

  • Choi, Jong Hyeon;Ko, Jun Seok;Lee, Jeong Eun;Park, Kyo Sik
    • Journal of Elementary Mathematics Education in Korea
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    • v.20 no.1
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    • pp.1-15
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    • 2016
  • In this paper, the following three issues are discussed in connection with intensive quantities. (1) Is there any relationship among intensive quantity, per unit quantity, and ratio? (2) Which intensive quantities obtained by two same extensive quantities are handled? And How are they handled? (3) Which intensive quantities obtained by two different extensive quantities are handled? And How are they handled? Based on the results of this discussions, three implications are suggested as conclusions to explore the direction for the development of handling intensive quantities in elementary math textbooks and workbooks. Firstly, it is necessary to systematize the systemize a series of processes to handle intensive quantities. There is a need to rethink to use terms like speed and velocity before handling the ratio. Secondly, there is a need to rethink the definition of intensive quantities which have the particular names. For example, it is necessary to rethink using average distance in the definition of speed and the average population in the definition of density of population. Thirdly, it is necessary to consider the limiting the kinds of intensive quantities obtained by two same extensive quantities handled in the elementary math. There is a need to set limit to them which are used in daily life, and there is a need to rethink to use them which are used in the specialized area. There is a need to rethink the using hitting ratio in the form of %.

Relationship between Reading Speed and Blinking Rate according to Longitudinal Chromatic Aberration during Book Reading (종이책 독서 시 종색수차에 따른 읽기속도와 순목횟수의 상관관계)

  • Kim, Se-il;Park, Mijung;Kim, So Ra
    • Journal of Korean Ophthalmic Optics Society
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    • v.20 no.3
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    • pp.369-375
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    • 2015
  • Purpose: The current study was performed to estimate the changes in reading speed and blinking rate according to different background colors when reading paper book and further investigate their correlation. Methods: Twenty-nine adults (10 males, 19 females) who consented to the present study and had no ocular disease, ocular surgery history showing normal binocular vision were participated into the study. The subjects were asked to read the novels with black letter printed on white, red, green and blue background for 15 min, respectively. Then, the reading speed per page and blinking rate per page were measured during reading and analyzed according to background colors. Results: Reading speed per page according to the background color showed a tendency to accelerate in the white and green background as the reading time increased however, it was almost unchanged in the blue background and rather decelerated in the red background. On the other hand, the blinking rate per page tended to decrease in all background as the reading time was increased however, the smallest reduction was shown in the red background. There was a correlation that the reading speed increased as the blinking rate decreased in all backgrounds and the best correlation was shown in the green background. Conclusions: From the results, a correlation between the increasing reading speed and the reducing blinking rate while reading paper book with same demand on accommodation and convergence was confirmed however, the change in blinking rate and reading speed was varied depending on the main wavelength of light. It might mean that the working speed and visual fatigue can be varied depending on the difference of main wavelength when doing near work. Thus, it can be suggested that the adjustment of working environment and conditions should be made according to the kind of required perception.

An Analysis of the Addition and Subtraction of Fractions in Elementary Mathematics Instructional Materials (분수의 덧셈과 뺄셈에 관한 초등학교 수학과 교과용 도서 분석)

  • Pang, Jeong-Suk;Lee, Ji-Young
    • Journal of Elementary Mathematics Education in Korea
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    • v.13 no.2
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    • pp.285-304
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    • 2009
  • The operations of fractions are the main contents of number and operations in the elementary mathematics curriculum. They are also difficult for students to understand conceptually. Nevertheless, there has been little study on the addition and subtraction of fractions. Given this, this paper explored the connection between the national mathematics curriculum and its concomitant textbooks, the adequacy of when to teach, and the method of constructing each unit to teach addition and subtraction of fractions. This paper then analyzed elementary mathematics textbooks and workbooks by three parts aligned with the general instructional flow: 'introduction', 'activity', and, 'exercise'. First, it was analyzed with regard to the introduction part whether the word problems of textbooks might reflect on students' daily lives as intended, how different meanings of operations would be expected to be taught, and how the subsequent activities were connected with the original word problems. Second, the main analysis of activity part of the textbooks dealt with how to use concrete or iconic models to promote students' conceptual understanding of operations and how to formalize the calculation methods and principles with regard to addition and subtraction of fractions. Third, the analysis of the part of exercise in the textbooks and workbooks was conducted with regard to problem types and meanings of operations. It is expected that the issues and suggestions stemming from this analysis of current textbooks and workbooks are informative in developing new instructional materials aligned to the recently revised mathematics curriculum.

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