• The Journal of Korean Institute of Communications and Information Sciences
• /
• v.27 no.2C
• /
• pp.170-183
• /
• 2002

This paper proposes an efficient frequency and symbol synchronization structure which could solve problems of the conventional methods to implement DVB-T receive modem which adopted OFDM transmission method. The main considerations of frequency synchronization algorithms are that the frequency tracking performance is not stable enough, and lots of symbols are required, especially when the decimal part of normalized frequency offset (which original frequency offset is divided by the subcarrier spacing) is around $\pm$0.5 to solve these problems, we propose an efficient frequency offset is divided by the subcarrier spacing) is around $\pm$0.5 by using the average of coarse synchronization over several symbol. Also, we suggest a new symbol synchronization structure which is easy to implement without performance degradation in multipath fading channel with only coarse symbol synchronization by making window offset to the range of guard interval in contrast to the conventional structure of dividing symbol synchronization in fine and coarse mode during synchronization. By extensive simulation, we have shown the superiority of the proposed schemes.

• Journal of the Korean Mathematical Society
• /
• v.44 no.5
• /
• pp.1163-1184
• /
• 2007

In this presentation dedicated to the tricentennial birth anniversary of the great eighteenth-century Swiss mathematician, Leonhard Euler (1707-1783), we begin by remarking about the so-called Basler problem of evaluating the Zeta function ${\zeta}(s)$ [in the much later notation of Georg Friedrich Bernhard Riemann (1826-1866)] when s=2, which was then of vital importance to Euler and to many other contemporary mathematicians including especially the Bernoulli brothers [Jakob Bernoulli (1654-1705) and Johann Bernoulli (1667-1748)], and for which a fascinatingly large number of seemingly independent solutions have appeared in the mathematical literature ever since Euler first solved this problem in the year 1736. We then investigate various recent developments on the evaluations and representations of ${\zeta}(s)$ when $s{\in}{\mathbb{N}}{\backslash}\;[1],\;{\mathbb{N}}$ being the set of natural numbers. We emphasize upon several interesting classes of rapidly convergent series representations for ${\zeta}(2n+1)(n{\in}{\mathbb{N}})$ which have been developed in recent years. In two of many computationally useful special cases considered here, it is observed that ${\zeta}(3)$ can be represented by means of series which converge much more rapidly than that in Euler's celebrated formula as well as the series used recently by Roger $Ap\'{e}ry$ (1916-1994) in his proof of the irrationality of ${\zeta}(3)$. Symbolic and numerical computations using Mathematica (Version 4.0) for Linux show, among other things, that only 50 terms of one of these series are capable of producing an accuracy of seven decimal places.

• Journal of the Korean Chemical Society
• /
• v.13 no.2
• /
• pp.121-129
• /
• 1969

The apparent and partial molal volumes({\phi}\nu$and $V^{\circ}$) of a series of homologous n-alkylamine hydrochlorides $C_nH_{2n+1}NH_3^+Cl^-$, where n varies from zero to four, have been determined by means of a float method at 30$^{\circ}C$ to the fifth decimal place down to 0.01M in aqueous solutions. The experimental results indicate that the partial molal volumes of the salts are almost additive for successive homologues depending on the increment of molecular weight ($CH_2$). It has been observed that the concentration dependence of the ${\Phi}v$ are linear in general and limiting slopes are positive and relatively close to the theoretical values. Anionic partial molal volume of chlorides anion $V^{\circ}_{Cl^-}$ is found to be 18.6 ml $mole^{-1}$, which is in good agreement with the results of other workers. {\phi}\nu$ data also show that in solution the hydrophobic effect of ions are in competition with the charge effect, but the latter, that is, electrostriction seemed to be considerably predominant.

• Journal of the Korean BIBLIA Society for library and Information Science
• /
• v.27 no.3
• /
• pp.25-50
• /
• 2016

Archives and Records Management Studies is being developed its own independent domains. However, the existing library classification scheme such as the KDC don't properly reflect the characteristics of Archives and Records Management Studies. This classification scheme has the irrational part of the arrangement of the subject items and should be required to rearrange subdivision of the subject areas. In this study, According to the characteristics of Archives and Records Management Studies, It is set up 8 subject areas, Records Management (General), the law and polices of records management, the collection and appraisal of the records, the documentary organization, recording information services, preservation of the records, archives management, archives and records center, etc. After analyzing the major contemporary library classification system such as KDC, DDC, NDC, UDC, LCC, then It is suggested that improvement measures through analyzing classification status and keywords of the Archives and Records Management data contained in Korean National Bibliography. In Archives and records management studies, The contents of the eight subject areas related to the field are changed to allow integration with KDC 028.

• Journal of the Korean Society for Library and Information Science
• /
• v.52 no.3
• /
• pp.61-89
• /
• 2018

The purpose of this study is to analyze the items related to digital reading and information literacy which were measured by PIAAC and PISA, to examine the measurement contents and methods of these literacy items, and to derive the implications for providing reading and information services for librarians at public libraries and teacher librarians. In order to solve the questions measuring digital reading literacy and digital information literacy, respondents commonly needed ICT skills as well as cognitive strategies. However, in digital reading literacy measurement items, the ability to comprehend and critically think about texts was emphasized. And in digital information literacy measurement items, the ability to use ICT skills, navigate, and evaluate whether or not to read the retrieved text was emphasized. Librarians and teacher librarians need to encourage readers to read and provide a customized competencies improvement program to reflect the performance results and characteristics of a particular group. And It is also necessary to improve and develop the library environment so that library user can understand and use library search system and the Korean decimal classification.

• Journal of the Korean Society for Library and Information Science
• /
• v.38 no.3
• /
• pp.249-275
• /
• 2004

The purpose of this study is to assist librarians in developing a bibliographic tool for bibliotherapy practices. Bibliotherapy is a form of psychotherapy in which carefully selected leading materials are used to assist a subject in solving personal problems or for other therapeutic purposes. However, bibliotherapy has rarely been either studied or practiced in Korea For a bibliographic tool which is called 'situational leading list', a client situation has to be classified by the factors of biological. place and personal relations. type of stress or symptoms. This study, in this regard, examined related recent researches In the field of psychology or psychoanalysis. Main conclusions made in this study are summarized as follows : The most important factors to classify a client situation in a bibliographic tool are age, sometimes sex, home background, personal relations and mental health issues. This study also suggest the scheme of situation classification according to the decimal classification system. There are the general class, child class, teenager class, adult class and senior class in the classification system.

• Journal of Educational Research in Mathematics
• /
• v.25 no.3
• /
• pp.263-279
• /
• 2015

The introduction of real numbers is one of the most difficult steps in the teaching of school mathematics since the mathematical justification of the extension from rational to real numbers requires the completeness property. The author elucidated what questions about real numbers can be unanswered as the "institutional didactic void" in school mathematics defining real numbers as the union of the rational and irrational numbers. The pre-service teachers' explanations on the extension from rational to real numbers and the raison d'$\hat{e}$tre of arbitrary non-recurring decimals showed the superficial and fragmentary understanding of real numbers. Connecting school mathematics to university mathematics via the didactic void, the author discussed how pre-service teachers could break the illusion of transparency about the real number.

• Journal of Korean Library and Information Science Society
• /
• v.36 no.1
• /
• pp.353-370
• /
• 2005

The purpose of this study aims to provide possible suggestions for the improvement of the korean Decimal Classification System in 21th century through the analysis of history field as the subject of study. As a result of this study, some problems(for example, irrational classification number system, very simplicity of $\lceil$Table of Geographic Areas. Historical Periods. Persons$\rfloor$. improper development of class 900, necessity of some internal tables and $\lceil$Table of Racial, Ethnic, National Groups$\rfloor$, insufficiency of note etc.) were found out. This study can be useful for the future revision of KDC4 because a revolutionary improvement were provided.

• Journal of Korean Library and Information Science Society
• /
• v.27
• /
• pp.171-209
• /
• 1997

The results of the study can be summarized as follows. The Shu-mu Da-wen was selected and compiled by Zhang Zhi Dong at the end of Qing Dynasty as a reading list for students preparing for the state examination and for the purpose of choosing the best from several versions. Whether it was compiled and edited by Zhang was in dispute. But it is almost certain that Zhang was the main editor because Shu-mu Da-wen showed his political, educational and scientific thoughts and knowledge distinctively. The followings are characteristics of Shu-mu Da-wen being compared with Si-ku Quan-shu Zong-mu Ti-yao. 1. In Jing-bu, the Confucian classics are divided into Zheng-jing Zheng-zhu and 'Lie-chao Jing-zhu Jing-shuo Jing-ben kao-zheng. Zheng-shi lei is divided into Zheng-shi fen he ke ben and Zheng-shi zhu bu biao pu kao-zheng. It is the special sorting method to include Du-ben lei in Jing-bu and Chu xue du-ben in Bie-lu in order to provide first learners for reading order. 2. Shi-bu included Gu-shi newly and Di-li lei is divided into Gu Di-li and Jin di-li in Shi-bu. Tian-wen Suan-fa lei is divided into Zhong-fa and Xi-fa in Zi-bu. Zhang distinguished between old books and contemporary ones to find out the origin and include newly published books in the East and the West. 3. Zhou-Qin zhu-zi is newly added to Zi-pu. In Ji-pu, Bie-ji and Zong-ji are categorized according to their style and period respectively. This show the new sorting method which added classifying system concerning academic development. It is the prominent feature in the compiling system to make Bie-lu and Cong-shu respective chapters. With those characteristics the Shu-mu Da-wen had been edited and published several times. It had a wide effect not only on compiling methods of cataloging afterwards and but also on classification systems before decimal classification was introduced in China.

• Journal of Advanced Navigation Technology
• /
• v.20 no.5
• /
• pp.496-502
• /
• 2016

In this paper, we proposed and implemented a GUI-based system to recognize and record measured values of digital instruments in the industrial site through image processing. Unlike the existing vehicle license plate recognition system, the measured values of the measuring instrument are displayed on the LCD screen as digital numbers. So, the proposed system considers the decimal point, a negative sign, light reflected by LCD protective glass, and various disturbance factors. We used blob-labeling technique to recognize the numbers displayed on the LCD screen, the recognized number images were determined as certain numbers through the template matching, and recognized values were recorded in the storage device with measurement time. Therefore, the proposed system in this paper would reduce the burden of writing when recording the measured values of the inside/outside diameter or height of the product in the industrial site, so effective and errorless process management in production process is possible by preventing errors in recording measurements when written by hand.