• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.16 no.11 s.102
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• pp.1138-1146
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• 2005

This paper makes a study of a formulation of net filter discrimination(NFD) and its computation for analyzing adjacent channel interference and suggests a systematic algorithm for calculating protection ratios of co-channel and adjacent channel applicable to frequency coordination in the fixed radio relay networks. It is shown that adjacent channel protection ratio can be derived from two factors: One is NFD depending upon receiver filter characteristic as well as transmitter spectrum mask and the other is co-channel protection ratio given by a function of fade margin, modulation scheme, and allowable interference. Actually to show the computing procedure from transmitter spectrum mask and receiver filter characteristic, NFD has been obtained for channel bandwidth of 29.65 and 40 MHz at 6.2 and 6.7 GHz band, respectively. According to the results, NFDs at the first adjacent channel of 29.65 and 40 MHz provide 27.4 and 28.9 dB, respectively. From these data, adjacent channel protection ratios corresponding to each channel bandwidth yield 47.5 and 46.3 dB for a given 64-QAM and 60 km. The proposed method gives some merits of an easy calculation, systematic extension, and applying the same concept to frequency coordination in millimeter radio relay networks.

• Journal of KIISE:Software and Applications
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• v.27 no.7
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• pp.769-783
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• 2000

In this paper, in order to disambiguate Korean noun word sense, we define a local context and explain how to extract it from a raw corpus. Following the intuition that two different nouns are likely to have similar meanings if they occur in the same local context, we use, as a clue, the word that occurs in the same local context where the target noun occurs. This method increases the usability of extracted knowledge and makes it possible to disambiguate the sense of infrequent words. And we can overcome the data sparseness problem by extending the verbs in a local context. The sense of a target noun is decided by the maximum similarity to the clues learned previously. The similarity between two words is computed by their concept distance in the sense hierarchy borrowed from WordNet. By reducing the multiplicity of clues gradually in the process of computing maximum similarity, we can speed up for next time calculation. When a target noun has more than two local contexts, we assign a weight according to the type of each local context to implement the differences according to the strength of semantic restriction of local contexts. As another knowledge source, we get a co-occurrence information from dictionary definitions and example sentences about the target noun. This is used to support local contexts and helps to select the most appropriate sense of the target noun. Through experiments using the proposed method, we discovered that the applicability of local contexts is very high and the co-occurrence information can supplement the local context for the precision. In spite of the high multiplicity of the target nouns used in our experiments, we can achieve higher performance (89.8%) than the supervised methods which use a sense-tagged corpus.

• Korean Journal of Cognitive Science
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• v.19 no.2
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• pp.143-161
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• 2008

The goal of this paper is to extract the hyponymy relation between words in the corpus. Adopting the basic algorithm of Hearst (1992), I propose a method of pattern-based extraction of semantic relations from the corpus. To this end, I set up a list of hypernym-hyponym pairs from Sejong Electronic Dictionary. This list is supplemented with the superordinate-subordinate terms of CoroNet. Then, I extracted all the sentences from the corpus that include hypemym-hyponym pairs of the list. From these extracted sentences, I collected all the sentences that contain meaningful constructions that occur systematically in the corpus. As a result, we could obtain 21 generalized patterns. Using the PERL program, we collected sentences of each of the 21 patterns. 57% of the sentences are turned out to have hyponymy relation. The proposed method in this paper is simpler and more advanced than that in Cederberg and Widdows (2003), in that using a word net or an electronic dictionary is generally considered to be efficient for information retrieval. The patterns extracted by this method are helpful when we look fer appropriate documents during information retrieval, and they are used to expand the concept networks like ontologies or thesauruses. However, the word order of Korean is relatively free and it is difficult to capture various expressions of a fired pattern. In the future, we should investigate more semantic relations than hyponymy, so that we can extract various patterns from the corpus.

• Korean journal of communication and information
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• v.46
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• pp.387-419
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• 2009

The concept of strategic group is defined as an aggregate of corporations utilizing similar strategies with similar resources. It becomes a kinds of contact point in the middle of corporation and industry between the industrial organization theory and the strategic management theory. This study tried to apply the strategic group model, which has been a main theory in the management studies, to program providing industry in Korea. This study shed lights upon research problems such as number of strategic groups, differences of strategic variables among the groups, finally differential performances according to strategic groups. 40 commercial broadcasting companies were analyzed to find answers. 9 strategic groups were drawn as a result of cluster analysis. Major variables which contribute to making groups were operating efficiency(4.05), pricing(3.83), size(number of system operator, 3.56), reliance on license revenue(2.58), horizontal integration(number of sister networks, 2.16) in order. An analysis of variance between performance variables has shown statistical significance regarding total net revenue per subscriber, however, insignificances statistically in regards to ratio of operating profit to net sales, cash Abstracts 687 flow ratio. Some studies in the past insisted that history variable played an important role to classifying strategic groups. However, this study found that the history didn't exert significant influence on either the group classification itself or performance.

• Journal of the Korean Chemical Society
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• v.18 no.5
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• pp.320-328
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• 1974

It is unable to derive the standard emf ($E^{\circ}$) of the cell at high pressure from the conventional method. However, when the concept of the complete equilibrium constant($K{\circ})$) is available to the conventional Nernst equation, it is possible to get the standard emf of the cell at high pressure(complete Nernst equation). Moreover, the other thermodynamic properties, such as the net change of solvation number(k), the compressibility of solvent(${\beta}$), ionization constant(K), the standard free energy change(${\Delta}G^{\circ}$), the standard enthalpy change(${\Delta}H^{\circ}$) and the standard entropy change (${\Delta}S^{\circ}$) of the cell reaction at equilibrium state have been also obtained. In this experiment, the emf of the cell; 12.5 % Cd(Hg)│$CdSO_4(3.105{\times}10^{-3}M),\;Hg_2SO_4│Hg$ have bee measured at temperature from 20 to $35^{\circ}C$ and at pressures from 1 to 2500 atms. The emf of the cell increased with increasing pressure at constant temperature, and did with increasing temperature at constant pressure. The net change of solvation number(k) of the cell reaction was 41.96 at $25^{\circ}C$, and kept constant value with pressure, while, K and ${\Delta}S^{\circ}$ increased with pressure, but whereas ${\Delta}G^{\circ}$ and ${\Delta}H^{\circ}$ decreased. Since the standard emf of the cell at high pressure can be calculated from the complete Nernst equation, the theory of chemical equilibrium could be developed with at high pressure as well as at the atmosphere.

• The Transactions of the Korea Information Processing Society
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• v.4 no.7
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• pp.1821-1841
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• 1997

This paper presents an automated protocol conformance test sequence generation based on formal methods for LOTOS specification by using and applying many existing related algorithms and technique, such as the testing framework, Rural Chinese Postman tour concepts. We use the state-transition graphs obtained from LOTOS specifications by means of the CAESAR tool. This tool compiles a specification written in LOTOS into an extended Petri net, from which a transition graph of a event finite-state machine(EvFSM) including data is generated. A new characterizing sequence(CS), called Unique Event sequence(UE sequence) is defined. An UE sequence for a state is a sequence of accepted gate events that is unique for this state. Some experiences about UE sequence, partial UE sequence and signature are also explained. These sequences are combined with the concept of the Rural Chinese Postman Tour to obtain an optimal test sequence which is a minimum cost tour of the reference transition graph of the EvFSM. This paper also presents a fault coverage estimation experience of an automated method for optimized test sequences generation and the translation of the test sequence obtained by using our tool to TTCN notation are also given. A prototype of the proposed framework has been built with special attention to real application in order to generated the executable test cases in an automatic way. This formal method on conformance testing can be applied to the protocols related to IN, PCS and ATM for the purpose of verifying the correctness of implementation with respect to the given specification.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.40 no.2
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• pp.91-108
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• 2022

In most cases, optical images have been used as training data of DL (Deep Learning) models for object detection, recognition, identification, classification, semantic segmentation, and instance segmentation. However, properties of 3D objects in the real-world could not be fully explored with 2D images. One of the major sources of the 3D geospatial information is DSM (Digital Surface Model). In this matter, characteristic information derived from DSM would be effective to analyze 3D terrain features. Especially, man-made objects such as buildings having geometrically unique shape could be described by geometric elements that are obtained from 3D geospatial data. The background and motivation of this paper were drawn from concept of the intrinsic image that is involved in high-level visual information processing. This paper aims to extract buildings after classifying terrain features by training DL model with DSM-derived information including slope, aspect, and SRI (Shaded Relief Image). The experiments were carried out using DSM and label dataset provided by ISPRS (International Society for Photogrammetry and Remote Sensing) for CNN-based SegNet model. In particular, experiments focus on combining multi-source information to improve training performance and synergistic effect of the DL model. The results demonstrate that buildings were effectively classified and extracted by the proposed approach.

• Information Systems Review
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• v.22 no.1
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• pp.59-72
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• 2020

Artificial Intelligence is establishing itself as a familiar tool from an intractable concept. In this trend, financial sector is also looking to improve the problem of existing system which includes Fraud Detection System (FDS). It is being difficult to detect sophisticated cyber financial fraud using original rule-based FDS. This is because diversification of payment environment and increasing number of electronic financial transactions has been emerged. In order to overcome present FDS, this paper suggests 3 types of artificial intelligence models, Generative Adversarial Network (GAN), Deep Neural Network (DNN), and Convolutional Neural Network (CNN). GAN proves how data imbalance problem can be developed while DNN and CNN show how abnormal financial trading patterns can be precisely detected. In conclusion, among the experiments on this paper, WGAN has the highest improvement effects on data imbalance problem. DNN model reflects more effects on fraud classification comparatively.

• Korean Journal of Social Welfare
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• v.54
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• pp.295-319
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• 2003

The study starts from the critical thought on why most of female-headed single-parent families are under poverty regardless of their hard working. The study is to explore the lives of low-income single-parent families as working poor and to develop comprehensive policies for them out of poverty and other social vulnerability, using the concept of social exclusion which has been broadly introduced in the field of social science. Specifically, the study aims to analyse the process of social exclusion of low-income single-parent households, by comparing the differential lives in the economic, social, political aspects among male-headed dual-parent household, female-headed single-parent household, and poor female-headed lone-parent household who is under the public poverty line. The study was based on the secondary data analysis. A total of 3182 samples(the first 2508, the second 235, and the third 439) were included. Using SAS 6.12, frequency, chi-square, means, and ANOVA were utilized for the statistical analysis. Results show that single mothers, on the whole, are vulnerable population in terms of employment, housing stability and income. Also, low-income households of single mothers are more negatively affected by the IMF economic crisis and carry more pessimism on their future. In comparison with male-headed households, single mothers have fewer support from social insurance as well as family resources and higher burdens of additional caring need for the old, the disabled, and the chronically ill. These findings identify the reality in which female-headed households with dependent children are exposed to the overall social vulnerability and thus are easily trapped into the social disadvantaged. finally, the study suggests the development of comprehensive policies and counter-measurements for low-income female-headed families to be the primary member in our society.

• Journal of Distribution Science
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• v.13 no.7
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• pp.85-90
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• 2015

Purpose - Global trends play a part to change the structure of the fashion industry. In particular, companies attempting to conduct innovative marketing centering on such products as SPA brands are growing into global companies. SPA stands for "Specialty Store Retailer of Private Label Apparel", meaning its activities are fully integrated from manufacturing through sales, including material procurement design, product, distribution, inventory management, and final sales. For this reason, more understanding of individual corporate profitability is very sensitive to consumer's attitudinal changes. The effects that corporate marketing activities on customer lifetime value through brand attitude were analyzed based on a structural equation model. Rust suggested value equity, brand equity, and relationship equity as customer equity driver. The study examines Chinese consumer because China is the fastest growing fashion market in the world. Research design, data, and methodology - The survey targeted Chinese college student age 20s. Only respondents who had purchased SPA brands in the past year were included for this research. A total of 303, except for 47 missing data of 350 distributed questionnaires were included in this research. The questionnaire is consists of six part to measure value, brand, relationship equity, attitude toward brand, purchase intention and demographic characteristics. This research conducted exploratory factor analysis and reliability test. To verify research hypotheses, structural equation model test was conducted. As for customer equity, diversified models in consideration of the scope of acquisition data, a method of collection of data, influencing factor, and predictability were suggested based on a net present value model. However, the history of customer equity study is relatively short, and sufficient empirical analyses have not been conducted, so more integrated analysis is required. In this study, the concept of driver suggested by Rust was applied to figure out the effects that consumer's attitude has on customer equity. The customer equity driver suggested by them consists of brand equity, value equity, and relationship equity. Results - This study reveals that value equity and brand equity have a positive influence on relationship equity. And, relationship equity has a positive influence on purchase intention through brand attitude. However, value equity and brand equity do not influence on brand attitude. Conclusion - The results of this research generated following implications. First, SPA brands need to take advantage of their value equity such as perceived low price and up-to-date fashion style to attract Chinese young consumer. Second, strong brand equity promises dominants position in the competitive market. As Chinese fashion market grows rapidly, SPA brands can consider branding strategy such as flagship store and celebrity marketing enhancing brand image. Third, the core concept of customer equity strategy is to maintain a relationship with their expecting and existing customers. The relationship equity is built by brand equity and value equity. When SPA brands serves product and service meet with individual customers, customers have intimacy to the brands.