• The Journal of the Acoustical Society of Korea
• /
• v.19 no.1
• /
• pp.97-102
• /
• 2000

Subband coding is to divide the signal frequency band into a set of uncorrelated frequency bands by filtering and then to encode each of these subbands using a bit allocation rationale matched to the signal energy in that subband. The actual coding of the subband signal can be done using waveform encoding techniques such as PCM, DPCM and vector quantizer(VQ) in order to obtain higher data compression. Most researchers have focused on the error in the quantizer, but not on the overall reconstruction error and its dependence on the filter bank. This paper provides a thorough analysis of subband codecs and further development of optimum filter bank design using vector quantizer. We compute the mean squared reconstruction error(MSE) which depends on N the number of entries in each code book, k the length of each code word, and on the filter bank coefficients. We form this MSE measure in terms of the equivalent quantization model and find the optimum FIR filter coefficients for each channel in the M-band structure for a given bit rate, given filter length, and given input signal correlation model. Specific design examples are worked out for 4-tap filter in 2-band paraunitary filter bank structure. These optimum paraunitary filter coefficients are obtained by using Monte Carlo simulation. We expect that the results of this work could be contributed to study on the optimum design of subband codecs using vector quantizer.

• Journal of the Korea Academia-Industrial cooperation Society
• /
• v.12 no.10
• /
• pp.4359-4368
• /
• 2011

Among several macroeconomic missteps blamed for the recent global financial crisis including the social problems of income distribution and the lack of proper financial remedies, two of them have received particular attention: the global BOP(Balance of Payment) imbalance and the misguided monetary policy. Such BOP imbalance was blamed for massive foreign exchange investment flows from Asia into the U.S., triggering the financial and real estate bubble in America. The latter refers to the excessively loose monetary policy of the U.S. Federal Reserve, which pushed financial institutions and households into reckless investment behavior in search of higher returns. Given the abuse of certain innovative financial techniques and new investment instruments that have been created in recent decades, both collateralized debt obligations (CDOs) and credit default swaps (CDS) enjoyed a symbiotic and toxic relationship prior to the financial crisis This paper is organized as follows: The first section analyzes the real causes of the recent financial crisis. The second details the role of CDOs and CDS. Then, to identify key determinants of the CDS spreads in an emerging capital market, the sample data of major Korean firms' CDS spreads are used to estimate the risk premium by utilizing the multiple regression analysis. The empirical test result indicates that Korean 3-year treasury bond rate(TYIELD), market to book value ratio(MV/BV), and assets size(INASSETS) are shown to demonstrate statistically significant influences on the changes of the CDS premium for sample firms.

• Journal of Information Management
• /
• v.25 no.1
• /
• pp.24-46
• /
• 1994

In this paper I will discuss definitions of hypermedia, multimedia and hypertext. Hypertext is the grouping of relevant information in the form of nodes. These nodes are then connected together through links. In the case of hypertext the nodes contain text or graphics. Multimedia is the combining of different media types for example sound, animation, text, graphics and video for the presentation of information by making use of computers. Hypermedia can be viewed as an extension of hypertext and multimedia. It is based on the concept of hypertext that uses nodes and links in the structuring of information in the system. In this case the nodes consist of an the different data types that are mentioned in the multimedia definition above. The 'node-and-link' concept is used in organisation of the information in hypermedia systems. The 'book' metaphor is an example of the way these systems are implemented. This concept is explained and a few advantages and disadvantages of making use of hypermedia systems are discussed. A new approach for the development of hypermedia systems, namely the knowledge-based approach is now looked into. Joel Peing-Ling Loo proposed this approach because he thought that it is the most effective way for handling this kind of technology. A semantic-based hypermedia model is developed in this approach to formulate solutions for the restrictions in presenting information authoring, maintenance and retrieval. The knowledge-based presentation of information includes the use of conventional data structures. These data structures make use of frames(objects), slots and the inheritance theory that is also used in expert systems. Relations develop between the different objects as these objects are included in the database. Relations can also exist between frames by means of attributes that belong to the frames.

• Journal of the Korean Society for information Management
• /
• v.21 no.3
• /
• pp.1-14
• /
• 2004

Visualization of documents will help users when they do search similar documents. and all research in information retrieval addresses itself to the problem of a user with an information need facing a data source containing an acceptable solution to that need. In various contexts. adequate solutions to this problem have included alphabetized cubbyholes housing papyrus rolls. microfilm registers. card catalogs and inverted files coded onto discs. Many information retrieval systems rely on the use of a document surrogate. Though they might be surprise to discover it. nearly every information seeker uses an array of document surrogates. Summaries. tables of contents. abstracts. reviews, and MARC recordsthese are all document surrogates. That is, they stand infor a document allowing a user to make some decision regarding it. whether to retrieve a book from the stacks, whether to read an entire article, etc. In this paper another type of document surrogate is investigated using a grouping method of term list. lising Multidimensional Scaling Method (MDS) those surrogates are visualized on two-dimensional graph. The distances between dots on the two-dimensional graph can be represented as the similarity of the documents. More close the distance. more similar the documents.

• The Journal of Korean Medical History
• /
• v.17 no.2
• /
• pp.111-127
• /
• 2004

This paper is mainly on the rsearch of the prescriptions of "Sanbeon-bang(刪 繁方)". For the research of prescription, investigated "Sanbeon-bang" from the side of symptoms of a disease, number of drugstuffs, table of contents, drugstuffs and acupuncture and moxibustion. With these investigation, made out a few tables, and with these tables made an attempt to understand the whole prescriptions of "Sanbeon-bang". "Sanbeon-bang" is of rich contents in internal medicine. Among internal medicine, related to Oro-Yukgeuk-Chilsang(五勞-六極-七傷) was most abundant. So we can guess "Sanbeon-bang" was a medical book specialized in exhaustion syndromes. It also deals with the Samcho-syndromes, as investigate from medical comments, has the perfect system of prescription in relative. From the investigation of the combination of drugstuffs, ascertained that, the number of simple prescription composed of one drugstuff was 38, combinational prescription composed of two drugstuffs was 9, minor prescription composed of three to five drugstuffs was 47, midum prescription composed of six to ten drugstuffs was 95, major prescription composed of eleven to twenty drugstuffs was 45, and mixed prescription composed over twenty drugstuffs was 1. Mentionable unique prescriptions in internal use were the forms of keeping in mouth. In external use they were fumigants, suppositories, powdered medicines, spraying the granular medication into the nasal cavity and eyedrops. And were abundant in soft extract(ointment) and plaster. In addition, there were the recordings of 18 types of cellulitis, types of incurable cellulitis and curing an illness by a charm. By the way, when comparing "Sanbeon-bang" with "Cheongeum-bang", all of which was quoted a lot in "Oedaebiyo-bang", "Cheongeum-bang" rather took medical comments of "Sanbeon-bang" than prescription. Although there were some prescriptons in "Sanbeon-bang" at the same category, "Cheongeum-bang" took another prescriptions which are more complexed than those of "Sanbeon-bang". In the same way, when comparing "Cheongeum-bang" with "Sonjinin-Cheongeum-bang(孫眞人千金方)", which didn't go through the correction of GyojeongUiseoguk of Bug-Song goverment, "Cheongeum-bang" often didn't take the prescriptions of "Sonjinin-Cheongeum-bang". Hence we can guess, "Cheongeumyo-bang" may have added a lot of prescriptions when undergoing the correction of of GyojeongUiseoguk. The total number of species of drugstuffs in "Sanbeon-bang" from the investigation was 284. The plant drugs were 208 species, the animal were 31 species, the minerals were 19 species and the other were 26 species. The prescriptions related to acupuncture and moxibustion in "Sanbeon-bang" were only moxibustional prescriptions. Which appeared one time per exhaustion and steaming of bone syndrome, Oro-Yukgeuk-Chilsang and Samcho syndrome. Appeared six times in muscle syndromes. But I cannot imagine the original form of acupuncture and moxibustion in "Sanbeon-bang" for deficiency of data.

• School Mathematics
• /
• v.11 no.3
• /
• pp.479-496
• /
• 2009

Some children can construct a basic concept of addition and subtraction during the preschool years. Children start to experience mathematics via numbers and their of operations and contact with various contexts of addition and subtraction. In special, word problems reflect mathematics which is appliable to real life. In this paper, I analyse the types of word problems in text book and its students' responses. First, I analyse the types of addition word problems which consist of change add-into situations and part-part-whole situations. Second, I analyse the types of subtraction word problems which consist of change take-away situations, compare situations and equalize situations. Third, I analyse the students' responses by the types of word problems in addition and subtraction. And 115 2nd grade elementary school students participated in this survey. The following results have been drawn from this study. First, the proposition of word problems of part-part-whole situations is higher than that of change add-into situations and the proposition of word problems of take-away situations is higher than that of compare situations and equalize situations. According to the analysis about students' responses, It is no difference between change add-into situations and part-part-whole situations. But the proposition of word problems of take-away situations is higher than that of compare situations and equalize situations. This results from word problems which contain unnecessary information in problem. So, we have to present the various word problems to students.

• Journal for History of Mathematics
• /
• v.21 no.4
• /
• pp.1-10
• /
• 2008

In this paper, we investigate the part dealing with algebra in Hong Gil Ju's GiHaSinSul to analyze his algebraic structure. The book consists of three parts. In the first part SangChuEokSan, he just renames Die jie hu zheng(疊借互徵) in Shu li jing yun to SangChuEokSan and adds a few examples. In the second part GaeBangMongGu, he obtains the following identities: $$n^2=n(n-1)+n=2S_{n-1}^1+S_n^0;\;n^3=n(n-1)(n+1)+n=6S_{n-1}^2+S_n^0$$; $$n^4=(n-1)n^2(n+1)+n(n-1)+n=12T_{n-1}^2+2S_{n-1}^1+S_n^0$$; $$n^5=2\sum_{k=1}^{n-1}5S_k^1(1+S_k^1)+S_n^0$$ where $S_n^0=n,\;S_n^{m+1}={\sum}_{k=1}^nS_k^m,\;T_n^1={\sum}_{k=1}^nk^2,\;and\;T_n^2={\sum}_{k=1}^nT_k^1$, and then applies these identities to find the nth roots $(2{\leq}n{\leq}5)$. Finally in JabSwoeSuCho, he introduces the quotient ring Z/(9) of the ring Z of integers to solve a system of congruence equations and also establishes a geometric procedure to obtain golden sections from a given one.

• Korean Journal of Construction Engineering and Management
• /
• v.6 no.1 s.23
• /
• pp.99-108
• /
• 2005

Interactive electronic technical manual(IETM) for construction projects means an electronic tool that regulations and specifications related to construction method or maintenance process ale described by electronic book type. It has a meaning of integrated information system that includes virtual reality(VR), 3D animation and image contents for representing real construction information so that user can easily understand the construction situation and maintenance process. The basic information and technical manuals of construction facilities are being written as paper documents in our construction industry. As the result, the information management in the maintenance phase of construction projects is inefficient, and maintenance cost is being increased. This study attempts to improve the lack of understanding about construction IETM through the analysis of necessity and unique function of construction IETM comparing with the IETMS in other industry, Finally, this study shows a scenario of construction IErM for mitigating natural disaster of construction facilities to verify applicability of IETM.

• Journal of Digital Convergence
• /
• v.13 no.2
• /
• pp.73-81
• /
• 2015

SNS is in the process of fast evolution as well. This study is about influence of authenticity and interactivity among Facebook Fan Page users. Authenticity is something people form in the process of expressing and sharing information thru SNS Facebook Fan Page. Interactivity is a level of participation of users in the process of expressing and sharing information thru SNS Facebook Fan Page. The focus of this paper is to see the power of authenticity and interactivity of SNS Facebook Fan Page users in a time of crisis. Authenticity is proven as a valuable asset for corporations for it showed a sturdy characteristic even when something terrible happened. When a crisis attacked, high authenticity user group was not willing to change their evaluation on a company reputation and image as much as low authenticity user group. Interestingly enough, the meaning interactivity level was strikingly different from what we expected. The more their level of interactivity, was the more they were likely to change their evaluation on a company in a time of crisis. A serious discussion is necessary for this contraty results.

• Korean Journal of Logic
• /
• v.8 no.1
• /
• pp.23-46
• /
• 2005

The purpose of the paper Is to discuss and estimate early Popper's theory of probability, which is presented in his book, The Logic of of Scientific Discovery. For this, Von Mises' frequency theory shall be discussed in detail, which is regarded as the most systematic and sophisticated frequency theory among others. Von Mises developed his theory to response to various critical questions such as how finite and empirical collectives can be represented in terms of infinite and mathematical collectives, and how the axiom of randomness can be mathematically formulated. But his theory still has another difficulty, which is concerned with the inconsistency between the axiom of convergence and the axiom of randomness. Defending the objective theory of probability, Popper tries to present his own frequency theory, solving the difficulty. He suggests that the axiom of convergence be given up and that the axiom of randomness be modified to solve Von Mises' problem. That is, Popper introduces the notion of ordinal selection and neighborhood selection to modify the axiom of randomness. He then shows that Bernoulli's theorem is derived from the modified axiom. Consequently, it can be said that Popper solves the problem of inconsistency which is regarded as crucial to Von Mises' theory. However, Popper's suggestion has not drawn much attention. I think it is because his theory seems anti-intuitive in the sense that it gives up the axiom of convergence which is the basis of the frequency theory So for more persuasive frequency theory, it is necessary to formulate the axiom of randomness to be consistent with the axiom of convergence.