• 한국전자거래학회지
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• 제9권3호
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• pp.277-288
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• 2004

멀티미디어 컨텐츠의 전송은 대용량 및 비정형적인 데이터를 처리해야하는 특성을 해결하는 데 목적이 있다. 이를 지원하기 위한 멀티캐스팅 기술에 대한 연구가 최근 활발히 진행되고 있다 본 연구에서는 멀티미디어 컨텐츠를 안정적이고 신속하게 전송하기 위해, 서버 그룹간의 멀티캐스트 라우팅을 지원하는 기법을 제안한다. 서버 노드의 부하에 따른 가중치에 따라 라우팅을 하여, 부하가 가중된 노드를 고려하여 컨텐츠 전송의 효율을 높이는 방법으로, 가중치는 멀티캐스트 서버의 통신 부하에 따라 계산한다. CDN(Contents Delivery Network)에서 둘 이상의 ES(Edge Server)가 존재하는 경우, 지연이 적은 라우팅을 제공함으로써 멀티미디어 컨텐츠를 효과적으로 전송할 수 있다. 멀티캐스트 서버간의 라우팅 기법을 설계하고 분석을 통해 네트워크의 부하를 줄여 네트워크 지연이 감소됨으로써 전체 네트워크 성능이 향상됨을 보인다.

• 수산해양교육연구
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• 제5권1호
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• pp.1-14
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• 1993

This study is to observe and activate a groping of education based on the perceptual responses from the teachers and the students in fisheries schools. The conclusions of this study are as follows : First, lower level of the perceptual response was estimated in the curriculum and experimental courses, the financial and administrative supports from the Government, the contribution of a fisheries high school to the local society the wages of seamen and the co-works between the industries and the academies. Second, a careful consideration is needed for the fisheries school to have a different shape. As one way for co-works of the industries and the academies, two year program in school and one year internship in a related company should be formed for the curriculum in a fisheries high school. A localized support for sea area, a fisheries high school's role as a re-eaducation for the seamaen and opening a educational graduate school for teachers in the fisheries university are pursued. Third, the perceptual response from the teachers and the students are globally weighted in the acquisition of the license with a graduation of the school and then the credit for the military services, the entering into the same area of the higher education, the expansion of the experimental materials in the courses, developing the curriculum, the Governmental supports and the awareness for the local society, in order. The issues indicated here should be researched continuously for activating the education in the fisheries high schools.

• 천문학회보
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• 제36권2호
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• pp.111.2-111.2
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• 2011

While many astrophysical disks are vertically stratified and obey a polytropic equation of state, most studies on gravitational instability (GI) of flattened systems consider isothermal, razor-thin disks by taking vertical averages of disk properties. We investigate local GI of rotating pressure-confined polytropic disks with resolved vertical stratification by performing linear stability analysis. We find that the GI of vertically-stratified disks is in general a combination of conventional razor-thin Jeans modes and incompressible modes. The incompressible modes that dominate in the limit of the maximal disk compression require surface distortion and are an unstable version of terrestrial water waves. Disks with a steeper equation of state are found to be more Jeans unstable because they tend to have a smaller vertical scale height as well as a steeper temperature gradient corresponding to lower pressure support. GI depends more sensitively on the vertical temperature than density distribution. The density-weighted, harmonic mean, rather than the simple mean, of the adiabatic sound speed well describes the dispersion relation of horizontal modes, and thus is appropriate in the expression for Toomre Q stability parameter of razor-thin disks. We generalize Q into vertically-stratified disks, and discuss astrophysical application of our work.

• 한국전문물리치료학회지
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• 제17권3호
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• pp.48-58
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• 2010

The aim of this study was performed to determine the inter-rater reliability of the Stroke Rehabilitation Assessment of Movement (STREAM) translated in Korean. This was a new clinical measurement tool for evaluating the recovery of voluntary movement and basic mobility following stroke. A direct-observation reliability study was conducted on 20 patients who had strokes and were in a rehabilitation setting. Subjects were assessed by two physical therapists. The reliability of the STREAM scores was demonstrated by weighted kappa statistics for inter-rater agreement on scores for individual items ranged from .83 to 1.0, intraclass correlation coefficients for total score was .99, and for subscale scores was ranged from .96 to .99. The internal consistency of the STREAM scores was demonstrated by Cronbach alphas of greater than .99 on the subscales and overall. These high levels of reliability support the use of the STREAM translated in Korean instrument for the measurement of motor recovery following stroke.

• 한국철도학회:학술대회논문집
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• 한국철도학회 2009년도 춘계학술대회 논문집
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• pp.91-98
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• 2009

For maintaining railroad, accumulated passing tonnage is a determinant factor of appropriate rail replacement time. Recently, Seoul Metro's rail maintaining system and technology is being improved from previous years, which increasing a standard of rail replacement. Thus, this brings importance of estimating and managing for accumulated passing tonnage. In case of light weighted train such as subway, current method of calculating accumulated passing tonnage has defaults of misrepresenting accumulated passing tonnage data. Because current method is based on the weight of passengers and train., and operation data. In addition, currently there is no mechanical and electronic system that could represent and support the accurate data between heavy and non-heavy traffic area, and accumulated passing tonnage is calculated inaccurately by estimating average value each line. The current method of calculating accumulated passing tonnage misleads to unpredictable data that represent inappropriate rail replacement period, which leads to under or over analyzed replacement period. If accumulated passing tonnage is over estimated, rail replacement leads to waste of budget. Hence, it is necessary to construct reliable actual measurement system to manage rail's life safely and efficiently, and in this study the accumulated passing tonnage measurement device is installed with using rail pad of optical fiber sensors and its effect is analyzed.

• 한국임상수의학회지
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• 제20권1호
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• pp.59-65
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• 2003

This study was performed to investigate the immunopotentiative effects of conjugated linoleic acid on mice immunosuppressed by administratin corticoids. Mice were divided into four groups of 8 mice. Two groups (C, CP) were given diet supplemented with 1% linoleic acid (CLA) and the other two groups (L, LP) were given diet supplemented with 1% linoleic acid (LA) instead of CLA. Prednison was administered to two groups (CP, LP) for immune depression. After feeding diets for 3 weeks containing PDS injection for last 1 week. Serum and gut lumen lavage were taken. Measurement of total Ig were executed using sandwich ELISA. Serum levels of IgA, IgG, and IgM showed some trend which groups fed with CLA were higher than groups fed with LA while IgE was reduced in those fed the CLA intake, and groups administered with PDS were lower than groups administered with saline. However, no significant differences were seen in the proportion of total immunoglobulin in serum. In case of secretory IgA, Group C and CP were significantly higher than group L and LP. Especially between CP and LP, it can be seen effects of CLA. In addition that the CLA treated group weighted a significantly lower level than the one's that have not been treated with CLA. These result support the view that CLA potentiate the immune response and prevent immune depression caused by administrating of corticoids. In conclusion, CLA produced a situation favorable for immunopotentiative effects. Thus, the clinical application of CLA is warranted.

• Journal of Astronomy and Space Sciences
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• 제35권1호
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• pp.39-46
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• 2018

In this study, the performance of ranging techniques for the Korea Pathfinder Lunar Orbiter (KPLO) space communication system is investigated. KPLO is the first lunar mission of Korea, and pseudo-noise (PN) ranging will be used to support the mission along with sequential ranging. We compared the performance of both ranging techniques using the criteria of accuracy, acquisition probability, and measurement time. First, we investigated the end-to-end accuracy error of a ranging technique incorporating all sources of errors such as from ground stations and the spacecraft communication system. This study demonstrates that increasing the clock frequency of the ranging system is not required when the dominant factor of accuracy error is independent of the thermal noise of the ranging technique being used in the system. Based on the understanding of ranging accuracy, the measurement time of PN and sequential ranging are further investigated and compared, while both techniques satisfied the accuracy and acquisition requirements. We demonstrated that PN ranging performed better than sequential ranging in the signal-to-noise ratio (SNR) regime where KPLO will be operating, and we found that the T2B (weighted-voting balanced Tausworthe, voting v = 2) code is the best choice among the PN codes available for the KPLO mission.

• 한국구조물진단유지관리공학회 논문집
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• 제6권2호
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• pp.233-244
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• 2002

The purposes of this research are to use the buildings efficiently and long, save energies, make the cozy and comfortable environment of residential and living spaces, rearrange the related acts for easy implementation of remodeling, and activate the government's support programs so as to make remodeling activated in a safe mode. The scope and methodology of this research include the review of existing literatures and data on remodeling, census on apartment residents, influence factors, and the development of methods for activation of building remodeling and strengthening of safety management, like activation measures, licensing and ordering regulation updates, etc regarding the remodeling. Safety inspection and in-depth inspection before and after remodeling should be regulated. The construction materials for remodeling should be light weighted and the construction methods which can minimize the impact and vibration during construction should be selected. The improvement of regulation on the remodeling contractor qualification and order method should be updated. If the remodeling is activated and safety management is reinforced by the suggested measures, solving of lack of house, prevention of abuse of resources, and improvement of residential environment could be accomplished rationally.

• ETRI Journal
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• 제27권6호
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• pp.777-787
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• 2005

In this paper, we propose an urgency- and efficiency-based wireless packet scheduling (UEPS) algorithm that is able to schedule real-time (RT) and non-real-time (NRT) traffics at the same time while supporting multiple users simultaneously at any given scheduling time instant. The UEPS algorithm is designed to support wireless downlink packet scheduling in an orthogonal frequency division multiple access (OFDMA) system, which is a strong candidate as a wireless access method for the next generation of wireless communications. The UEPS algorithm uses the time-utility function as a scheduling urgency factor and the relative status of the current channel to the average channel status as an efficiency indicator of radio resource usage. The design goal of the UEPS algorithm is to maximize throughput of NRT traffics while satisfying quality-of-service (QoS) requirements of RT traffics. The simulation study shows that the UEPS algorithm is able to give better throughput performance than existing wireless packet scheduling algorithms such as proportional fair (PF) and modified-largest weighted delay first (M-LWDF), while satisfying the QoS requirements of RT traffics such as average delay and packet loss rate under various traffic loads.

• 한국디지털건축인테리어학회논문집
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• 제7권2호
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• pp.51-58
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• 2007

The saying likely as "In the rapidly-changing outside management environment, the light-weighted body only able to survive" means the 'lightness' in working space, reducing expenditure for immovable property and unnecessary facility, and also means the flexibility of facility which is ready to cope promptly with the approaching situation. For such reason, as many enterprises do not support an individual workstation for each person but by introduction of sharing system, also reducing the area for working space, they have made the immovable property expense per person curtailed. Though the reduction of the immovable property expense that subsequently gained by merely decreasing of working space brings a remarkable effect of retrenchment, there is also a worrying opinion that because of the narrowed working space than before, or by disappearing of private space, a possible non-productive effect which let working enthusiasm falls down might be brought. By practicing such investigating method, at the first stage survey, the Satisfaction of non-territorial and territorial office user and the order of required improvement are figured out, also arranged the appraisal items as 6 factors in total, and all of the factors were being influenced to the entire satisfaction in statistically meaningful level.