• Journal of the Institute of Electronics Engineers of Korea TC
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• v.43 no.7 s.349
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• pp.14-23
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• 2006

Wireless Sensor Network(WSN) consists of huge number of sensor nodes which are small and inexpensive with very limited resources. The public key cryptography is undesirable to be used in WSN because of the limitations of the resources. A key management and predistribution techniques are required to apply the symmetric key cryptography in such a big network. Many key predistribution techniques and approaches have been proposed, but most of-them didn't consider the real WSN assumptions, In this paper, we propose a security framework that is based on a hierarchical grid for WSN considering the proper assumptions of the communication traffic and required connectivity. We apply simple keying material distribution scheme to measure the value of our framework. Finally, we provide security analysis for possible security threats in WSN.

• Journal of the Korea Institute of Information Security & Cryptology
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• v.7 no.3
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• pp.41-52
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• 1997

In this paper, we analyze two claws of Zhou-Gollmann's protocol. The protocol divide the message into a key K and a ciphertext C. The ciphertext C is delivered to the recipient, but the key K is submitted to the TTP, after the message originator receive the recipient's receipt for the ciphertext. TTP puts the key in the directory which is accesaible to the public. So, the recipient's obtaining the message dependson whether the originator submits the key or not. We will show that the originator. which is in such an advantageous position, could make the protocol be unfair and present how to improve the protocol. On the other hand, Zhou-Gollmann's protocol doesn't provide the secrecy of the message, since the key K is published. This means that, to send a secret message, additional mechanism is required. In this paper, we will present an improvement of Zhou-Gollmann's protocol to keep the message secret. The key distribution of the proposed protocol is based on the Diffie-Hellman's one.

• Health Policy and Management
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• v.25 no.2
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• pp.71-79
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• 2015

With the growth of aging population in Korea, a better care of chronic and other degenerative illnesses is urgently needed. Evidences suggest that this can be achieved through incorporating a wide range of care options, expanding beyond medical interventions. The aim of this study is to analyze the distribution of publically funded research to understand if the Korean research and development funding system matches various approaches and purposes to successfully tackle the chronic care needs of an aging society. We complied the list of funded projects to be analyzed by searching the National Technical Information Service database with key words such as aging society/senescence, chronic diseases, disability, and health promotion. Most projects were based on the biomedical approach with the purpose of establishing the etiology and clinical (treatment) interventions. Health promotion projects showed a distinctive distribution with more percentage of projects based on psycho-behavioral approaches while research on chronic diseases predominantly biomedical. It would be necessary to diversify publically-funded research projects to develop effective and efficient care technologies for the future.

• Journal of Korea Society of Digital Industry and Information Management
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• v.9 no.4
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• pp.103-110
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• 2013

In Information Technology era, various amazing IT technologies, for example Big Data, are appearing and are available as the amount of information increase. The number of counselling for violation of personal data protection is also increasing every year that it amounts to over 160,000 in 2012. According to Korean Privacy Act, in the case of treating unique personal identification information, appropriate measures like encipherment should be taken. The technologies of encipherment are the most basic countermeasures for personal data invasion and the base elements in information technology. So various cryptography algorithms exist and are used for encipherment technology. Therefore studies on safer new cryptography algorithms are executed. Cryptography algorithms started from classical replacement enciphering and developed to computationally secure code to increase complexity. Nowadays, various mathematic theories such as 'factorization into prime factor', 'extracting square root', 'discrete lognormal distribution', 'elliptical interaction curve' are adapted to cryptography algorithms. RSA public key cryptography algorithm which was based on 'factorization into prime factor' is the most representative one. This paper suggests algorithm utilizing telescoping series as a safer cryptography algorithm which can maximize the complexity. Telescoping series is a type of infinite series which can generate various types of function for given value-the plain text. Among these generated functions, one can be selected as a original equation. Some part of this equation can be defined as a key. And then the original equation can be transformed into final equation by improving the complexity of original equation through the command of "FullSimplify" of "Mathematica" software.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.10 no.11
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• pp.1996-2001
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• 2006

Open System Authentication Method, Shared Key Method, Mac Based Authentication Method are very hard to use in wireless network that needs security. So now, many researches have been performed about 802.1x and user authentication method applying PKI. but certificate verification protocol has been used abolished list called CRL since it's first usage of PKI, there were still has a problem about distribution point. This paper applied CVS to use CA direct not to use CRL and OSCP server in order to improve this problems. Also It suggested the system that can make authentication steps more shorter using authentication server and Mutual authentication system by public certificate(small size/low speed wireless terminal can access to wireless network fast and safely)

• Health Policy and Management
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• v.18 no.2
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• pp.19-38
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• 2008

Financial ratios are key indicators of an organization's financial and business conditions. Among various financial indicators, profitability, financial structure, financial activity and liquidity ratios are frequently used and analyzed. Using the structural equation modeling(SEM) technique, this study examines the structural causal relationships among key financial indicators. Data for this study are taken from complete financial statements from 142 hospitals that passed the standardization audit undertaken by the Korean Hospital Association from 1998 to 2001 for the purpose of accrediting teaching hospitals. In order to improve comparability, ratio values are standardized using the Blom's normal distribution. The final model of the SEM has four latent constructs: financial activity(total asset turnover, fixed asset turnover), liquidity(current ratio, quick ratio, collection period), financial structure(total debt to equity, long-term debt to equity, fixed assets to fund balance), and profitability(return on assets, normal profit to total assets, operating margin to gross revenue, normal profit to gross revenue). While examining several model fit indices(Chi-square (df) = 178.661 (40), likelihood ratio=4.467, RMR=.11, GFI=.849, RMSEA=.157), the final SEM we employed shows a relatively good fit. After examining the path coefficient of the constructs, the financial structure of the hospital affects the hospital's profitability in a statistically significant way. A hospital which utilizes its liabilities, more specifically fixed liabilities, and makes a stable investment decision for fixed assets was found to have a higher profitability than other hospitals. Then, the standard path coefficients were examined to directly compare the influence of variables. It was found that there were no statistically significant path coefficients among constructs. When it comes to variables, however, statistically significant relationships were found. between. financial activity and. fixed. asset turnover, and between profitability and normal profit to gross revenue. These results show that the observed variables of fixed asset turnover and normal profit to gross revenue can be used as indicators representing financial activity and profitability.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.13 no.8
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• pp.3917-3941
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• 2019

The recent interest in artificial intelligence and machine learning has partly contributed to an interest in the use of such approaches for hyperspectral remote sensing (HRS) imagery classification, as evidenced by the increasing number of deep framework with deep convolutional neural networks (CNN) structures proposed in the literature. In these approaches, the assumption of obtaining high quality deep features by using CNN is not always easy and efficient because of the complex data distribution and the limited sample size. In this paper, conventional handcrafted learning-based multi features based on expert knowledge are introduced as the input of a special designed CNN to improve the pixel description and classification performance of HRS imagery. The introduction of these handcrafted features can reduce the complexity of the original HRS data and reduce the sample requirements by eliminating redundant information and improving the starting point of deep feature training. It also provides some concise and effective features that are not readily available from direct training with CNN. Evaluations using three public HRS datasets demonstrate the utility of our proposed method in HRS classification.

• Korean Institute of Interior Design Journal
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• v.21 no.5
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• pp.343-354
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• 2012

Museums in Korea have experienced continuing quantitative growth since the late Choson Dynasty. However, a careful examination of visitors' viewing behavior has not been properly performed. Accordingly, social education for visitors in museums is not properly conducted despite the vast amount of information that museums possess. Given these circumstances, this study which focuses on the factors that influence visitors' behavior in museums intends to examine the effects that the configuration of exhibition space and the resulting visitor circulation patterns have on visitors' behavior with regard to visitor density. From this perspective, and considering five public historical museums within the seoul metropolitan area of korea, a correlation analysis has been conducted based upon quantitative analysis related to the configuration of exhibition space and visitors' observed viewing behaviors. The result of our study is that the configuration of exhibition space influences the patterns of visitor circulation, distribution of space, and the subsequent state of visitor density. Accordingly, the effects of visitor density on the viewing speed and other viewing behaviors could be identified. Based on these findings, the configurational differences in exhibition spaces were identified as one of the key factors that influence visitors' viewing behaviors.

• The Journal of Asian Finance, Economics and Business
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• v.8 no.3
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• pp.201-208
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• 2021

This study aimed to identify the key factors that affect the financial market performance (Price-Earnings Model) through a sample of 35 public shareholding industrial companies on the Amman Stock Exchange for the period 2010-2019, using statistical models and methods, such as the Simple Linear Regression Model, Correlation Coefficient, and dispersion board. The study results showed the nonexistence of a statistically significant effect between the intellectual capital and market value added (MVA) and market performance. Results also showed a statistically significant positive effect between financial leverage (FL) and the market performance, where the interpreted variation reached 64%. It showed from the analysis results that the relationship between (MVA) and market performance (P/E) agrees with the study hypotheses, while the result related to (FL) disagrees with the study hypotheses. The study recommends that public shareholding industrial companies should focus more on intellectual capital and show its value in the annual financial statements and reports, and those companies that have high profitability and the chance to hold gains and profits should rely less on debt and more on retained earnings, due to the high risk of debt and in line with the present unstable circumstances in Jordan, especially in light of the global Covid-19 crisis.

• The Journal of Asian Finance, Economics and Business
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• v.8 no.8
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• pp.251-258
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• 2021

In recent years, there have been several studies on service quality in higher education, however, research on service quality and sustainable activities affecting student loyalty has been largely ignored in previous studies. This paper investigates the role of service quality in creating student loyalty, and how university sustainability practices and student satisfaction mediate the relationship between service quality and student loyalty. The paper draws attention to university sustainability practices and understanding its impact on student satisfaction and loyalty in Vietnamese public universities. A quantitative methodology is explored, and data was collected through an online structured questionnaire. Responses are gathered from 278 students of public universities in Ho Chi Minh City, Vietnam. Structural equation modeling is used to examine the associations between the constructs by using the PLS-SEM approach. The results show that service quality has a significant effect on university sustainability practices, student satisfaction, and student loyalty. In addition, university sustainability practices and student satisfaction also mediate the relationship between service quality and student loyalty. The author's findings may guide the key decision-makers in universities to incorporate service quality and universities' sustainability practices in their strategy and thereby improve student satisfaction and student loyalty.