• 한국통신학회논문지
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• 제28권12C호
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• pp.1258-1267
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• 2003

최근에 초고속 무선인터넷 서비스로 각광받고 있는 무선랜 환경에서 무선랜 단말이 액세스포인트사이를 로밍할 때 무선랜단말의 안전한 핸드오프를 위한 프로토콜로서 IAPP가 있고 관련된 IEEE표준으로 802.11f가 있다. 무선 랜단말의 안전한 핸드오프를 위해서는 IAPP를 통하여 기존에 접속되었던 액세스포인트에서 새로운 액세스포인트에게 무선랜단말의 인증 또는 과금관련정보를 안전하게 전달하는 것이 필요하다. IEEE 802.11f에서는 무선랜단말의 핸드오프를 지원하는 액세스포인트를 인증하고 액세스포인트사이의 안전한 통신을 위한 정보를 제공하는 IAPP 서버로 라디우스 서버를 권고한다. 본 논문에서는 라디우스 서버의 한계를 극복하고 보다 확장성과 신뢰성이 뛰어난 서버를 위해 Diameter를 사용한 IAPP서버를 설계하고 서버의 동작과 기존 시스템과의 연동방안에 대해서 설명한다.

• 디지털융복합연구
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• 제13권11호
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• pp.133-139
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• 2015

본 연구의 목적은 고용창출과 고용유지를 활성화하기 위해 규정된 "조세특례제한법"상의 조세지원제도를 통해 효용성 극대화를 위한 개선방안을 제시하는데 있다. 연구결과를 간략히 기술하면 다음과 같다. 첫째, 고용창출과 고용유지를 장려하기 위한 세제혜택인 세액감면과 세액공제에 대한 중복공제를 허용하고 고용 유발효과의 극대화를 위해 최저한세 적용대상에서 제외시켜야 한다. 둘째, 최저임금 기준초과액에 대한 세액공제 및 세액감면을 신설한다. 셋째, 중소기업 위주의 조세지원 대상을 비영리 중견 대기업으로 확대해야 한다. 넷째, 기업의 인적자원관리의 예측가능성을 높이고, 현재 세대 및 미래 세대의 고용창출과 안정을 위하여 조세지원의 일몰기한을 폐지하거나 대폭 확대해야 한다. 마지막으로 소득세 및 법인세의 조세부담이 없는 기업을 대상으로 조세특례제한법상의 고용지원 관련 규정의 이행상황을 종합적으로 평가하여 일정 기준 이상의 고용성과를 달성한 기업들에게는 세액공제 및 세액감면 외에 정부보조금을 지급할 수 있는 방안을 추가적으로 고려해야 한다. 이러한 논의는 고용정책과 조세법의 융합을 전제로 도출된 것이다.

• Wind and Structures
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• 제19권3호
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• pp.339-352
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• 2014

This paper discusses the appropriate duration for basic gust wind speeds in wind loading codes and standards, and in wind engineering generally. Although various proposed definitions are discussed, the 'moving average' gust duration has been widely accepted internationally. The commonly-specified gust duration of 3-seconds, however, is shown to have a significant effect on the high-frequency end of the spectrum of turbulence, and may not be ideally suited for wind engineering purposes. The effective gust durations measured by commonly-used anemometer types are discussed; these are typically considerably shorter than the 'standard' duration of 3 seconds. Using stationary random process theory, the paper gives expected peak factors, $g_u$, as a function of the non-dimensional parameter ($T/{\tau}$), where T is the sample, or reference, time, and ${\tau}$ is the gust duration, and a non-dimensional mean wind speed, $\bar{U}.T/L_u$, where $\bar{U}$ is a mean wind speed, and $L_u$ is the integral length scale of turbulence. The commonly-used Durst relationship, relating gusts of various durations, is shown to correspond to a particular value of turbulence intensity $I_u$, of 16.5%, and is therefore applicable to particular terrain and height situations, and hence should not be applied universally. The effective frontal areas associated with peak gusts of various durations are discussed; this indicates that a gust of 3 seconds has an equivalent frontal area equal to that of a tall building. Finally a generalized gust response factor format, accounting for fluctuating and resonant along-wind loading of structures, applicable to any code is presented.

• Structural Engineering and Mechanics
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• 제52권6호
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• pp.1069-1084
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• 2014

The long-term performance of plates resting on viscoelastic foundations is a major concern in the analysis of soil-structure interaction. As a powerful mathematical tool, fractional calculus may address these plate-on-foundation problems. In this paper, a fractionalized Zener model is proposed to study the time-dependent behavior of a uniformly loaded rectangular thin foundation plate. By use of the viscoelastic-elastic correspondence principle and the Laplace transforms, the analytical solutions were obtained in terms of the Mittag-Leffler function. Through the analysis of a numerical example, the calculated plate deflection, bending moment and foundation reaction were compared to those from ideal elastic and standard viscoelastic models. It is found that the upper and lower bound solutions of the plate response estimated by the proposed model can be determined using the elastic model. Based on a parametric study, the impacts of model parameters on the long-term performance of a foundation plate were systematically investigated. The results show that the two spring stiffnesses govern the upper and lower bound solutions of the plate response. By varying the values of the fractional differential order and the coefficient of viscosity, the time-dependent behavior of a foundation plate can be accurately captured. The fractional differential order seems to be dependent on the mechanical properties of the ground soil. A sandy foundation will have a small fractional differential order while in order to simulate the creeping of clay foundation, a larger fractional differential order value is needed. The fractionalized Zener model is capable of accounting for the primary and secondary consolidation processes of the foundation soil and can be used to predict the plate performance over many decades of time.

• Journal of Biosystems Engineering
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• 제33권4호
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• pp.260-268
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• 2008

Optical diffuse reflectance sensing has potential for rapid and reliable on-site estimation of soil properties. For good results, proper calibration to measured soil properties is required. One issue is whether it is necessary to develop calibrations using samples from the specific area or areas (e.g., field, soil series) in which the sensor will be applied, or whether a general "factory" calibration is sufficient. A further question is if specific calibration is required, how many sample points are needed. In this study, these issues were addressed using data from 42 paddy fields representing 14 distinct soil series accounting for 74% of the total Korean paddy field area. Partial least squares (PLS) regression was used to develop calibrations between soil properties and reflectance spectra. Model evaluation was based on coefficient of determination ($R^2$) root mean square error of prediction (RMSEP), and RPD, the ratio of standard deviation to RMSEP. When sample data from a soil series were included in the calibration stage (full information calibration), RPD values of prediction models were increased by 0.03 to 3.32, compared with results from calibration models not including data from the test soil series (calibration without site-specific information). Higher $R^2$ values were also obtained in most cases. Including some samples from the test soil series (hybrid calibration) generally increased RPD rapidly up to a certain number of sample points. A large portion of the potential improvement could be obtained by adding about 8 to 22 points, depending on the soil properties to be estimated, where the numbers were 10 to 18 for pH, 18-22 for EC, and 8 to 22 for total C. These results provide guidance on sampling and calibration requirements for NIR soil property estimation.

• The Journal of Asian Finance, Economics and Business
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• 제4권2호
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• pp.75-80
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• 2017

Hand phones are standard paraphernalia among university students. Factors that motivate them to own the gadget would be of interest to both the students as well as marketers. Hand phone usage is an unexamined field in academic literature, this exploratory study attempts to investigate student purchasing motives in cellular phone markets. It also intends to know the student's satisfaction with the different services and its future impact on socio economic changes. In this study, undergraduates (n=336) were requested to specify their purchase criteria of hand phone. The instrument used in the study to collect feedback from the respondents contains a combination of open-ended and scaled questions, and some background demographics. The study employed content analysis, Pearson's correlation, and t-tests as the primary tools to analyze the responses. Results show that brand was rated as the most important factor in student purchase decisions. Other factors, arranged in decreasing order of importance comprise price, product quality, features, durability, availability, promotion, and post purchase service. Brand and price correlated significantly. It is also observed that there is very little difference regarding preference between brand and price in purchasing a hand phone. Marketers may formulate suitable strategies out of the findings to promote hand phones to university undergraduates in Malaysia by emphasizing at brands and price.

• 대한간호학회지
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• 제20권3호
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• pp.341-356
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• 1990

Cancer is still a threat to human beings. The incidence and mortality rate of cancer have been gradually increasing as the life span has been lengthened. Radiotherapy is one of the most commonly used treatments for cancer. This study explored the influence of social support and stress on sick role behavior of patients receiving radiotherapy for cancer. The subjects for this study were 60 patients undergoing radiotherapy for cancer, selected from the radiotherapy treatment unit of the out patient departments of two major medical centers in Jeonju. Data were collected from February 1 to 28, 1990 by a Likert Scale Questionnaire and an interview schedule designed by the inverstigator. Data analysis included percentages, mean and standard deviation, t or F-test, Pearson Correlation Coefficient and stepwise multiple regression. Results included the following : 1. Support came primarily from sons and daughters (90.1%) ; the type of support was primarily emotional support from friends(60.0%) ; informational support came from health personnel(81.7%) ; and material support was sons and daughters(40.0%) ; satisfaction with support was highest for the spouse(4.02$\pm$.52). 2. Among the patient's demographic status was occupation the was the only socioeconomic characteristic influencing sick role behavior (F＝2.91 , p＝.029). 3. Directly perveived support was positively correlated with sick role behavior (r＝.2374, p＝.034). 4. Stepwise multiple regression was used to determine the predictors of sick role behavior. Directly perceived support was the most significant predictor accounting for the hightest contribution to sick role behavior(5.6%). Directly perceived support. socioeconomic status, perceived stress and indirectly perceived support variables together, accounted for only 6.8% of sick role behavior.

• Journal of Ecology and Environment
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• 제35권3호
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• pp.243-249
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• 2012

Biomass expansion factors, which convert timber volume (or dry weight) to biomass, are used for estimating the forest biomass and accounting for the carbon budget at a regional or national scale. We estimated the biomass conversion and expansion factors (BCEF), biomass expansion factors (BEF), root to shoot ratio (R), and ecosystem biomass expansion factor (EBEF) for Quercus mongolica Fisch. and Quercus variabilis Bl. forests based on publications in Korea. The mean BCEF, BEF, and R for Q. mongolica was 1.0383 Mg/$m^3$ (N = 27; standard deviation [SD], 0.5515), 1.3572 (N = 27; SD, 0.1355), and 0.2017 (N = 32; SD, 0.0447), respectively. The mean BCEF, BEF, and R for Q. variabilis was 0.7164 Mg/$m^3$ (N = 17; SD, 0.3232), 1.2464 (N = 17; SD, 0.0823), and 0.1660 (N = 8; SD, 0.0632), respectively. The mean EBEF, as a simple method for estimating the ground vegetation biomass, was 1.0216 (N = 7; SD, 0.0232) for Q. mongolica forest ecosystems, and 1.0496 (N = 8; SD, 0.0725) for Q. variabilis forest ecosystems. The biomass expansion factor values in this study may be better estimates of forest biomass in Q. mongolica or Q. variabilis forests of Korea compared with the default values given by the Intergovernmental Panel on Climate Change (IPCC).

• Asian Pacific Journal of Cancer Prevention
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• 제17권3호
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• pp.1577-1581
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• 2016

Tobacco use is a well-established risk factor for many types of cancers. Recent data on selected cancer incidence and mortality related to smoking in the Indonesian population are provided in this study. Morbidity and mortality data were derived from GLOBOCAN 2012 and the population attributable fraction (PAF) was estimated using the standard methodology developed by the World Health Organization. Using these data, we calculated disability adjusted life year (DALY) values for smoking-related cancer. The DALY was estimated by summation of the years lived with disability (YLD) and years life lost due to premature death (YLL). The cancer cases related to smoking in Indonesia numbered 45,132, accounting for 35,580 cancer deaths. The morbidity and mortality of lung cancer can be considered as the highest priority in both men and women. Furthermore the greatest YLD due to smoking in Indonesian men and women were from pancreas and lung cancers. For YLL among men, the highest years lost were from lung and liver cancers. On the other hand, among women lung oral cavity and lip were most important. Based on the DALY indicator, burden priorities for Indonesian men were lung cancer (298,980), liver cancer (60,367), and nasopharynx (46,185), while among Indonesian women they were lung cancer (34,119), cervix uteri (9,213) and pancreas cancer (5,433). In total, Indonesian burden of cancers attributed to smoking was 638,682 DALY. This study provides evidence about the burden of cancers caused by smoking as a rational basis for initiating national tobacco control policies in Indonesia.

• 한국인터넷방송통신학회논문지
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• 제14권5호
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• pp.27-33
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• 2014

UCI (Universal Content Identifier) 식별체계가 국가표준식별체계로 자리를 잡으면서 다양한 저작물의 디지털 콘텐츠에 대하여 UCI 식별자가 부여되어 유통이 이루어지고 있으나, 콘텐츠의 저작권 정보 부재로 인해 의도되지 않은 저작권 침해 행위 발생 및 저작권 계약 등에 있어 많은 문제점이 발생하고 있다. 통합저작권관리번호인 ICN (Integrated Copyright Number)는 국내에서 저작권 관리를 위해 개발된 코드체계로 저작물 활용에 따른 사용내역에 대한 정산과 분배, 불법 모니터링, 필터링을 목적으로 하며, 권리자의 보호를 위해 저작물에 대한 저작권 관계 정보를 포함하고 있다. 그러나 ICN은 그 목적이 저작권 관리에 집중되어 있어 디지털콘텐츠자체의 속성이나 유통에 필요한 정보들을 포함하고 있지 않다. 따라서 생산되는 디지털저작물을 보다 효율적으로 관리하고 유통하기 위해서는 콘텐츠를 식별하기 위한 식별체계인 UCI와 디지털저작물에 대한 권리의 소유관계를 식별할 수 있는 저작권 권리관리체계인 ICN과 연계와 통합은 권리자와 사업자간의 투명하고 효과적인 저작물 유통의 기반이 될 수 있다. 본 논문에서는 UCI 식별체계와 ICN 식별체계를 연계와 통합의 관점에서 식별체계간의 정책적 요인들과 핵심적인 기술 요소를 분석하고 각 식별체계의 가치사슬간의 효율화를 기할 수 있는 연계 및 통합 인프라의 구축에 대한 모델을 제시하고자 한다.