• Journal of Environmental Science International
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• v.22 no.8
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• pp.953-963
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• 2013

Reliable long-term streamflow forecasting is invaluable for water resource planning and management which allocates water supply according to the demand of water users. Forecasting of seasonal inflow to Andong dam is performed and assessed using statistical methods based on hydrometeorological data. Predictors which is used to forecast seasonal inflow to Andong dam are selected from southern oscillation index, sea surface temperature, and 500 hPa geopotential height data in northern hemisphere. Predictors are selected by the following procedure. Primary predictors sets are obtained, and then final predictors are determined from the sets. The primary predictor sets for each season are identified using cross correlation and mutual information. The final predictors are identified using partial cross correlation and partial mutual information. In each season, there are three selected predictors. The values are determined using bootstrapping technique considering a specific significance level for predictor selection. Seasonal inflow forecasting is performed by multiple linear regression analysis using the selected predictors for each season, and the results of forecast using cross validation are assessed. Multiple linear regression analysis is performed using SAS. The results of multiple linear regression analysis are assessed by mean squared error and mean absolute error. And contingency table is established and assessed by Heidke skill score. The assessment reveals that the forecasts by multiple linear regression analysis are better than the reference forecasts.

• Journal of Korea Society of Digital Industry and Information Management
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• v.6 no.4
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• pp.95-105
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• 2010

DNS(Domain Name System) is a huge distributed database that converts host name to IP address. We are expecting the importance of DNS is more increased because many Internet application services appear according to the continuous increase of Internet users and nearly all the Internet application services use DNS. To prevent the interruption of DNS service, DNS server is configured with primary DNS server and a secondary DNS server which takes the place of primary DNS server in case of the service interruption. But this scheme is difficult for providing DNS service constantly in case of DDoS attack, which brings about much network load or network problems in DNS server group. Therefore, This paper proposed the scheme to locally distribute load of DNS server, and the use of address system to group the distributed DNS servers. Also, it proposed the authentication scheme of the correspondent server in case the server is changed in DNS server group having grouping address. In this paper, it is shown that the prosed scheme guarantees the improved service reliability with maintaining the present service performance through the evaluation. Through this, we can expect the high improved DNS service can be provided in the Internet environment in the future.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.15 no.3
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• pp.73-76
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• 2015

In this paper, we propose energy harvesting apply to spectrum sensing. In this case, we can be spectrum sensing without consume energy. Algorithms of sensing and harvesting are determine active or idle of primary network, Compares with the threshold energy and the amount of energy that is harvested by energy harvesting scheme. If the secondary network want to send a message while the primary network is active, secondary users will change frequency to use the spectrum. Further, if the secondary network has not message, it will continues harvest energy. Therefore, spectrum sensing applied the energy harvesting method, energy of secondary network is remove waste and charge energy. So, efficiency and utilization of cognitive network can be increase.

• Asia pacific journal of information systems
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• v.29 no.3
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• pp.328-358
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• 2019

Business-to-Business electronic commerce websites are a common form of inter-organizational systems that span organizational boundaries and enables organizations to exchange information in a seamless fashion. To reap the desired benefits it is important that the website be used in the intended manner. The level and extent of use of a business-to-business website depends partly on the inclination to use the website by the users in the primary organization and in the user organizations independently and the combined inclination of the organizations together. This combined inclination is referred to as the System Inclination, with dominance playing a key role. Each organization has certain characteristics of its own and may differ significantly in their inclination to use. It is important to analyze the factors that determine this inclination to use, so that organizations can adopt appropriate management mechanisms to control it. This paper proposes a framework to explain the organizational factors and their influence on the inclination to use a website, based on study of four Indian buyer-supplier dyads. Inclination to use is found to be influenced by factors like top management support, website characteristics, adequate support mechanisms, user group orientation towards electronic commerce and basic IT drive among the employees, at both the primary and user organizations.

• Journal of Korean Academy of Nursing Administration
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• v.6 no.1
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• pp.83-96
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• 2000

With the increased use of computers in medical fields, we can consider introducing computer mediated communication into the area of patient care such as medical or health counseling and education. But little was known about what problems can be counseled, what is the main direction of counseling, and what difficulties are met during the computer mediated counseling. So I conducted this study. This is a fundamental study concerning the health counseling by the inter-net. In this study, medical counseling using a method of questioning -answering through a computer mediated communication system was carried out from June 1998 to May 1999. I analyzed the contents of questions and answers by the ICPC classification. The ICPC classification emerged as a standard for information categorization in Primary Health Care within a few years. One of the most prominent features of this classification is the inclusion of the complaints of the patients (symptoms & complaints) and the social problems (Chapter Z). Thus, and for the first time, the demand of patients may be assessed such as it is expressed in the reality. The ICPC list is now an international standard whose validity is not questioned any more. It is translated in more than twenty different languages. The data collected were analyzed by descriptive statistical method, c2 test by cross tabulations. Followings are the results of this study. 1. The 3,054 users composed of 64% of males and 36% of females. The highest number of users was showed in the age group of $25{\sim}29$ (39.4%). 2. During the one-year period, the average number of counseling per user was 2.5 cases and per day was 21.1 cases. 3. In classifying symptoms and complaints by 17 chapter, digestive(17.6%), general and unspecified (12.7%), skin(12.7%) and musculoskeletal system (9.6%) were most common questions. 4. The distribution of diagnosis by 17 chapter, general and unspecified (21.4%), digestive (15.3%), skin (11.9%) and mus- culoskeletal system (8.9%) were most common answers. 5. Many users wanted to know symptoms and complaints(3,609 cases), treatment principles (2,928 cases), prognosis and preventive methods for health problems which were previously diagnosed (284 cases).

• Journal of the Korea Society of Computer and Information
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• v.18 no.4
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• pp.171-181
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• 2013

In the recent information-oriented age, various information technologies (ITs) have been introduced in construction industries. However, since construction ITs tend to be employed by the demand of the government or owners rather than the demand of information accepters (users), this tendency inhibits the spread of user-friendly construction ITs. In order to find these inhibitive factors, this research conducted practical studies, based on Davis' technology acceptance model, for construction ITs' acceptance according to the information accepters' (users) features. This study was hypothesized whether or not each inner and outer factors with respect to construction ITs are influential to the information accepters (users). As a result of this study, the primary factors which can maximize the usefulness and ease of use and should be considered when developing new information technologies were suggested.

• Journal of Internet Computing and Services
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• v.16 no.4
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• pp.93-99
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• 2015

The purpose of this study was to explore the reasons why college students use Facebook and the ways in which they feel of social presence while using Facebook. In fact, the study aimed to specify the links between motivations for using SNS and a sense of 'being together'. The findings of this study suggest that major motivations of SNS use were social interaction, entertainment, self-presentation, and information-seeking. Specifically, results from a survey of 280 respondents revealed that college students used Facebook to seek maintenance and connection with friends, to express themselves, to get information about school activities, and to be entertained. These findings are consistent with the existing literature regarding SNS as a primary channel to maintain the existing social relationships among college students. The study also found that all motivation factors, except information-seeking factor, were positively and significantly related to social presence. The strongest correlations were between social presence and Facebook use for social interaction and entertainment needs. It seemed that users who seek social interaction and entertainment needs are more likely to feel a sense of being with others while users who seek to get information are less likely to feel a sense of social presence. These findings implied that to some extent, a sense of social presence occurs in the context of Facebook and that the experience of social presence depends on what college students seek from Facebook use. In addition, the results showed a positive relationship between Facebook use and social presence; the more college students use Facebook, the more they are likely to experience sense of social presence. Given that Facebook provides college students with a place where they can share thought and feelings among friends, it can be concluded that Facebook contributes to the sense of belonging among users. And such feeling may enhance a sense of presence with others while using Facebook. These findings suggest that uses and gratifications researchers should consider the concept of social presence as an important variable in explaining what audience members do with media.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.12 no.4
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• pp.1594-1617
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• 2018

In this paper, we consider a spectrum access scenario which consists of two groups of users, namely Primary Users (PUs) and Secondary Users (SUs) in Cooperative Cognitive Radio Networks (CCRNs). SUs cooperatively relay PUs messages based on Amplify-and-Forward (AF) and Decode-and-Forward (DF) cooperative techniques, in exchange for accessing some of the spectrum for their secondary communications. From the literatures, we found that the Conventional Distributed Algorithm (CDA) and Pragmatic Distributed Algorithm (PDA) aim to maximize the PU sum-rate resulting in a lower sum-rate for the SU. In this contribution, we have investigated a suit of distributed matching algorithms. More specifically, we investigated SU-based CDA (CDA-SU) and SU-based PDA (PDA-SU) that maximize the SU sum-rate. We have also proposed the All User-based PDA (PDA-ALL), for maximizing the sum-rates of both PU and SU groups. A comparative study of CDA, PDA, CDA-SU, PDA-SU and PDA-ALL is conducted, and the strength of each scheme is highlighted. Different schemes may be suitable for different applications. All schemes are investigated under the idealistic scenario involving perfect coding and perfect modulation, as well as under practical scenario involving actual coding and actual modulation. Explicitly, our practical scenario considers the adaptive coded modulation based DF schemes for transmission flexibility and efficiency. More specifically, we have considered the Self-Concatenated Convolutional Code (SECCC), which exhibits low complexity, since it invokes only a single encoder and a single decoder. Furthermore, puncturing has been employed for enhancing the bandwidth efficiency of SECCC. As another enhancement, physical layer security has been applied to our system by introducing a unique Advanced Encryption Standard (AES) based puncturing to our SECCC scheme.

• Journal of the Ergonomics Society of Korea
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• v.29 no.4
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• pp.569-574
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• 2010

After the beginning of Web2.0 era, newly developed interaction design patterns based on Ajax(Asynchronous JavaScript and XML) have been tried in various Web2.0 services. These new interaction design patterns enable web service to provide rich experience for users. However, it is very hard to find organized task based guideline about Web2.0 interaction design even though there are a lot of complicated interaction design techniques and patterns. It is essential to have Web2.0 interaction guide based on Ajax because it can guide designers to use appropriate interaction design patterns and to keep usability for ordinary users. Therefore, this research aims to establish task based interaction design guideline for Web2.0 service based on Ajax. The reason why this research focused on Ajax is that Ajax is most widely used language for Web2.0 service. First, primary five interaction design patterns were defined through analysis of various interaction design patterns from Web2.0 services. Second, detail interaction design tasks from five major patterns were analyzed based on the study of major Web2.0 services such as Gmail, Twitter, YouTube and Google maps. Third, general design guidelines such as heuristic guidelines for web service are studied through literature review. After all, this study proposed task based interaction design guide for Web2.0 service with Ajax. With this guide, designers and developers can choose appropriate Web2.0 interaction patterns and apply to their service and provide service to users with enhanced usability and satisfaction.

• Journal of Environmental Science International
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• v.19 no.4
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• pp.427-436
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• 2010

In this study this author made research and analysis on physical status and characteristics of community parks in Ik-san provinces and also depending on its potential resources such parks were classified into constructed parks and unconstructed parks and status of use of such parks and level of satisfaction were studied. Through this paper this author strived to provide basic data required for forming green track of land for the parks. Required time for visiting community parks either constructed or unconstructed type was within 40 minutes or less. However constructed parks appeared to be more convenient for access in comparison with natural unconstructed parks. Mostly they were used by residents in neighboring community and also residents in the area around it were found as using it frequently. At the time of using community parks either constructed or unconstructed types means of access were mostly by walking or by riding bicycles. Thus considering large number of users of such parks are from neighboring community it appeared that parks with its simplicity and convenience in terms of distance and with rich nature were preferred by users rather than large scale parks at distance. In terms of time frame of use and motivation of visit constructed parks were used mainly for exercise and relaxation in the morning at parks and its facilities whereas un constructed parks were mostly used in the afternoon for for walking and chatting and rest under with time to spare at shadows of its trees. Time spent at parks were composed mostly of rest and walking more frequently than exercise and leisure activity thus it was different from motivation for visiting parks. As for evaluation of use of parks natural elements, unique environment, trees and lawns featured highly in unconstructed parks in comparison with constructed parks. Thus it seemed visitors are more conscious of forest and landscape in a form of unchanged nature. Thus for community parks first consideration should be heightening accessibility in view of primary concern for convenience by users rather than facilities or environmental conditions.