• 한국위성정보통신학회논문지
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• 제1권1호
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• pp.40-47
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• 2006

차세대 이동 통신 기술은 무선 환경에서 고속 및 고품질의 데이터 전송을 요구하고 있다. OFDM 기술은 대역폭당 전송 속도의 향상과 멀티패스 간섭 등의 방지를 위한 디지털 변조 방식으로 무선 환경에서 다양하게 응용되고 있다. 본 논문에서는 MBMS(Multimedia Broadcast and Multicast Service)와 같이 무선 환경에서 여러 개의 서비스를 동시에 제공하는 다중 서비스 환경에 OFDM을 적용할 때 필요한 부채널 배정에 관한 알고리즘을 제안하였다. 제안한 방법은 각 서비스의 채널 환경을 고려하여 부채널을 분배할 수 있을 뿐만 아니라 서비스의 우선순위를 고려해서 우선순위가 높은 서비스에 더 많은 부채널 분배가 가능하고 기존의 부채널 배정 알고리즘과 비교할 때 수렴 속도의 향상과 계산량 감소의 장점이 있다.

• 산업경영시스템학회지
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• 제38권4호
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• pp.30-38
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• 2015

IT security service provides customers with the capability of protecting the networked information asset and infrastructures, and the scope of security service is expanding from a technology-intensive task to a comprehensive protection system for IT environment. To improve the quality of this service, a research model which help assess the quality is required. Several research models have been proposed and used in various service areas, but few cases are found for IT security service. In this work, a research model for the IT security quality has been proposed, based on research models such as SERVQUAL and E-S-QUAL. With the proposed model, factors which affect the service quality and the best quality measure have been identified. And the feasibility of using quantitative measures for quality has been examined. For analysis, structural equation modeling and various statistical methods such as principal component analysis were used. The result shows that satisfaction is the most significant measure affected by the proposed quality factors. Two quality factors, fulfillment and empathy, are the main determinants of the service quality. This leads to a strategy of quality improvement based on factors of emotion and perception, not of technology. The quantitative measures are considered as promising alternative measures, when combined with other measures. In order to design reliable quantitative measures, more work should be done on target processing time and users' expectation. It is hoped that work of this research will provide efficient tools and methods to improve the quality of IT security service and help future research works for other IT service areas.

• 한국통신학회논문지
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• 제31권10A호
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• pp.960-967
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• 2006

이동통신은 시간과 장소의 제약없이 유비쿼터스하게 인간 중심의 서비스를 제공할 수 있는, 차세대 시스템을 향하여 진화하고 있다. 특히, 사용자의 요구와 사용자 주변 상황들이 동적으로 변화하고 있는 차세대 이동통신 환경에서 다양한 센서 및 장치 그리고 관련 기술들에 의해 상황 인식(Context Awareness)이 실현될 것이다. 이러한 상황 인식을 바탕으로 차세대 이동통신 환경에서는 사용자의 요구와 사용자 주변 상황에 가장 적절한 서비스가 제공되는 상황 인식 서비스가 핵심 서비스로 부상될 것이다. 본 논문에서는 서비스 사용자와 서비스 제공자들을 연결시켜 주는 차세대 이동통신 서비스 플랫폼을 기반으로 제공되는 차세대 이동통신 서비스 환경을 기술한다. 그리고, 이러한 서비스 환경에서 차세대 통합망, 센서 및 센서 네트워킹 기술, 단거리 통신 기술의 발전에 따른 상황 정보수집 범위의 확대, 서비스 이용 범위의 다양성 등에 따라 분류된 상황 인식 서비스의 진화 단계를 제시한다.

• International Journal of Computer Science & Network Security
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• 제22권8호
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• pp.35-44
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• 2022

The Internet is extremely important to accomplish numerous items, from education to businesses and entertainment. Therefore, the quality of its performance must be efficient. Nowadays, there is a lack of information available for users to choose a suitable Internet service. What information is available might be insufficient, inaccurate, or regularly updated. Accordingly, there is a need to develop an electronic system that enables users to evaluate their current Internet service subscription. Several factors are used as evaluation criteria in the system that affect users' decisions. In this paper, a prototype of a design science research project is proposed to address a few objectives. First, it can help Internet service users in Saudi Arabia to make the best decision for themselves regarding Internet services subscriptions. Second, it can assist the Saudi government to seek one of the 2030 vision goals: the digital transformation that depends on having a good Internet connection. The proposed solution is a promising one that would help Internet service users to make the best decision for themselves and choose the best Internet service that fits their needs. A qualitative method has been used to evaluate the efficiency and the utility of the proposed system prototype. The results showed the extent of participants' acceptance of the Internet Service Evaluation System.

• 한국통신학회논문지
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• 제27권4B호
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• pp.338-344
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• 2002

This paper proposes a transient (predictive) connection admission control (CAC) scheme using the transient quality of service (QoS) measure for CDMA cellular systems with bursts On-Off sources. We need an approximate and bounded approach for real-time CAC applications. We derive the transient outage probability as the QoS measure using the Chernoff bound and the refuted large deviation approximation. Numerical results show that the predictive CAC is a promising approach for the multicell CDMA systems.

• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 2000년도 가을 학술발표회 논문집(II)
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• pp.1091-1094
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• 2000

An experimental study is carried out to estimate the way of applying the granulated blast furnace slag[GBFS] to the lean concrete subbase of concrete pavement. According to the test results, this application seems promising. For this application, mixing percent of GBFS ranging from 30 to 45 is recommendable at this stage. Expected benefits using GGBFS in the field of concrete pavement include reduced shrinkage crack, reduced pavement thickness, and extended service life.

• 한국정보처리학회:학술대회논문집
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• 한국정보처리학회 2012년도 추계학술발표대회
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• pp.763-764
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• 2012

Web Services are considered to be a promising technology to add a new level of functionality to the existing World Wide Web. However, despite the growing use of Web Services by many organizations, there are several issues that are slowing their deployment such as service discovery, recovery from faults and security. In this paper, we give a detailed overview of issues surrounding Web Services, discuss existing solutions and describe their limitations.

• 대한산업공학회지
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• 제33권1호
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• pp.153-163
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• 2007

An adaptive framework paradigm where the bandwidth values of the ongoing calls vary according to the trafficsituations is one of the promising concepts for overcoming poor resource conditions due to handoffs in mobilecellular networks. However, quantifying the level of bandwidth degradation of the ongoing calls in an adaptiveframework is important in view of Quality of Service (QoS) Provisioning. Therefore we introduce new QoSparameters, the Degradation Degree Ratio (DDR), which represents the average portion of the degradationdegree during degradation pehod of a call, and the Degradation Area Ratio (DAR), which represents the averageratio of a call's degradation level considering both the period and the degree of degradation jointly in multi-levelbandwidth service. We also develop a new analytical model for estimating the QoS measures such as theDegradation Pehod Ratio (DPR), DDR and DAR. We show how to calculate the QoS measures and illustrate themethod by numerical examples. The proposed model can be used to determine the optimal parameter of theCAC scheme and analyze the sensitivity ofthe QoS parameters in adaptive networks.

• Computers and Concrete
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• 제12권6호
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• pp.755-774
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• 2013

Considering the well known environmental issues of cement manufacturing (direct and indirect levels of $CO_2$ emissions), clinker replacement by supplementary cementing materials (SCM) can be a very promising first step in reducing considerably the associated emissions. However, such a reduction is possible up to a particular level of SCM utilization, influenced by the rate of its pozzolanic reaction. In this study a (4-step) structured methodology is proposed in order to be able to further adjust the concrete mix design of a particular SCM, in achieving additional reduction of the associated levels of $CO_2$ emissions and being at the same time accepted from a derived concrete strength and service life point of view. On this note, the aim of this study is twofold. To evaluate the environmental contribution of each concrete component and to provide the best possible mix design configuration, balanced between the principles of sustainability (low environmental cost) and durability (accepted concrete strength and service life ). It is shown that such a balance can be achieved, by utilising SCM by-products in the concrete mix, reducing in this way the fixed environmental emissions without compromising the long-term safety and durability of the structure.

• 유통과학연구
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• 제15권2호
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• pp.21-26
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• 2017

Purpose - Sharing economy is a promising research topic as a complementary approach for solving difficult issues resulting from market economy. Motive factors for consumer participation in sharing economy are necessary to facilitate the growth of sharing economy. This study analyzes motives for participating in sharing economy using samples from a car sharing service in South Korea. Research design, data, and methodology - Four hypotheses drawn from a new research model integrating the relationships between economic and social value, social value, and the intention to use sharing economy services were proposed. 292 valid samples were collected from Socar users in South Korea. Multiple regression analysis was employed to test the hypotheses. Results - An empirical study identified the importance of convenience and time savings as determinants of intention to use continuously a car sharing service. Cost savings and social value did not significantly influence the intention to use car sharing service. Conclusions - The present study implies that managers working in sharing economy don't have to miss a role of convenience. Although a new finding implies that convenience is an important factor influencing car sharing service, the present study has a limitation of generality that samples are mostly collected from the age range of 20 to 30 years.