• 산업경영시스템학회지
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• 제36권4호
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• pp.45-58
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• 2013

Korean local governments have been planning for u-City construction with great efforts. Such efforts are needed in order to reflect the urban characteristics of each city, to promote local economic growth, and to have a sustainable operation model. Thus it is critical at an earlier stage to set a strategic direction based on urban environment analysis, which will lead to a feasible implementation of u-City. This paper derives issues and suggests improvement methods based on a case study on the USPs (u-City Strategy Planning's) of ten local governments. It is expected that the improvement methods will greatly reduce risks involved in u-City construction and contribute to better provided local-specific u-services.

• Journal of electromagnetic engineering and science
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• 제17권3호
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• pp.133-137
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• 2017

In this study, a 28-GHz U-slot array antenna for a wideband communication system is proposed. The U-slot patch antenna structure consists of a patch, two U-shaped slot, and a ground plane. With the additional U-slot, the proposed antenna has around 10% of bandwidth at -10 dB. To increase gain, the U-slot antenna is arrayed to $2{\times}2$. The proposed antenna is designed and fabricated. The $2{\times}2$ array antenna volume is $41.3mm{\times}46mm{\times}0.508mm$. The proposed antenna was measured and compared with the simulation results to prove the reliability of the design. The bandwidth and gain of the measurement results are 3.35 GHz and 13 dBi, respectively and the operating frequency is around 28 GHz.

• 콘크리트학회논문집
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• 제12권6호
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• pp.43-50
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• 2000

In this paper, a new splicing method was applied to design the girder section of bridges with the span length of 25m, 30m, 35m, 40m and 45m. A U-type precast prestressed section was also determined for each bridge. Additionally, the sectional area, beam depth and Guyon's efficiency factor of the spliced U-type sections in each span were analyzed in comparison with the present I-type PSC bridges. As a result, in spite of an increase of 31%∼50% in the sectional areas compared with the I-type precast girders, the spliced U-type the beam depth of the spliced U-type girder was designed as 2,050 mm compared with the I-type precast girder of 2,600mm in a 40m span bridge. The sectional efficiency factors of the spliced U-type sections were analyzed as 0.76∼0.99. It shows that the spliced U-type sections ar of a superior structural efficiency in contrast to the average sectional efficiency factor of 0.66 value in the I-type girders.

• 한국전자통신학회논문지
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• 제10권9호
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• pp.1049-1058
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• 2015

본 논문은 U-교통서비스 품질요인과 사용자만족의 관계에 대하여 독립변수로 U-교통서비스 품질요인인 서비스품질과 시스템품질을, 매개변수로 공공성, 유용성, 경제성을, 종속변수로 사용자만족으로 각각 구성하였다. SPSS 18.0을 이용하여 요인분석, 신뢰도분석, 다중회귀분석, 경로분석을 실시하였으며 결과는 다음과 같다. 첫째로 U-교통서비스 품질요인이 직접적으로 사용자만족에 정적 영향을 미치며 둘째로 U-교통서비스 품질요인이 공공성, 유용성, 경제성을 매개하여 간접적으로 사용자만족에 정적 영향을 미치며 셋째로 U-교통서비스 품질요인 중 서비스품질이 시스템품질보다 사용자만족을 높게 나타냈으며 넷째로 공공성, 유용성, 경제성의 매개변수중에서 유용성이 사용자만족을 높게 나타냈다.

• 한국전자거래학회지
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• 제14권1호
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• pp.13-34
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• 2009

최근 유비쿼터스 컴퓨팅 기술이 발전함에 따라서 유비쿼터스 컴퓨팅 기술을 이용한 다양한 서비스들이 개발되고 있고, 일부 u-서비스들은 상용화되고 있다. 이와 더불어 u-서비스의 비즈니스 모델에 대한 연구의 중요성 또한 커지고 있다. 하지만 비즈니스 모델에 대한 명확한 정의가 없고, 작성되는 비즈니스 모델의 방법론이 통일되지 않는 등 u-서비스에 대한 구조적인 비즈니스 모델을 작성하는 구조적인 방법론이 아직 거의 존재하지 않는다. 더욱이 현재 개발된 비즈니스 모델 작성 및 분석 방법론은 기존 전통적인 서비스나 e-service를 대상으로 작성된 반면 u-service의 특성에 대한 고려가 되고 있지 않다. 따라서 본 논문에서는 비즈니스 모델 개념의 정의와 비즈니스 모델의 설계, 분석에 이르는 비즈니스 모델에 대한 통합 방법론을 개발하는 것이 목적이다. 이를 위해 u-서비스에 맞는 모델 컴포넌트를 포함한 비즈니스 모델링 다이어그램(BMD)라고 하는 도구를 제안하였다.

• 한국정보통신설비학회:학술대회논문집
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• 한국정보통신설비학회 2007년도 학술대회
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• pp.181-184
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• 2007

Up to now, a lot of houses, roads and other urban facilities have been damaged by natural disasters such as flash floods and landslides. It is reported that the size and frequency of disasters are growing greatly due to global warming. In order to mitigate such disaster, flood forecasting and alerting systems have been developed for the Han river, Geum river, Nak-dong river and Young-san river. These systems, however, do not help small municipal departments cope with the threat of flood. In this study, a real-time urban flood forecasting service (U-FFS) is developed for ubiquitous computing city which includes small river basins. A test bed is deployed at Tan-cheon in Gyeonggido to verify U-FFS. Wireless sensors such as rainfall gauge and water lever gauge are installed to develop hydrologic forecasting model and CCTV camera systems are also incorporated to capture high definition images of river basins. U-FFS is based on the ANFIS (Adaptive Neuro-Fuzzy Inference System) that is data-driven model and is characterized by its accuracy and adaptability. It is found that U-FFS can forecast the water level of outlet of river basin and provide real-time data through internet during heavy rain. It is revealed that U-FFS can predict the water level of 30 minutes and 1 hour later very accurately. Unlike other hydrologic forecasting model, this newly developed U-FFS has advantages such as its applicability and feasibility. Furthermore, it is expected that U-FFS presented in this study can be applied to ubiquitous computing city (U-City) and/or other cities which have suffered from flood damage for a long time.

• 대한수학회지
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• 제56권1호
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• pp.197-224
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• 2019

Let A be a $JB^*$-triple with Banach dual space $A^*$ and bi-dual the $JBW^*$-triple $A^{**}$. Elements x of $A^*$ of norm one may be regarded as normalised 'Q-measures' defined on the complete ortho-lattice ${\tilde{\mathcal{U}}}(A^{**})$ of tripotents in $A^{**}$. A Q-measure x possesses a support e(x) in ${\tilde{\mathcal{U}}}(A^{**})$ and a compact support $e_c(x)$ in the complete atomic lattice ${\tilde{\mathcal{U}}}_c(A)$ of elements of ${\tilde{\mathcal{U}}}(A^{**})$ compact relative to A. Necessary and sufficient conditions for an element v of ${\tilde{\mathcal{U}}}_c(A)$ to be a compact support tripotent $e_c(x)$ are given, one of which is related to the Q-covering numbers of v by families of elements of ${\tilde{\mathcal{U}}}_c(A)$.

• 자원환경지질
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• 제33권4호
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• pp.261-271
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• 2000

In order to evaluate the environmental impact of U anormaly in the drainage system around the Shinbo talc mine area, U contents, their distribution patterns, bioaccumulation and a-radioactivity in stream water, stream sediments and aquatic organisms were investigated. The U contents of stream water attenuated with increasing distance from the mine area. The same attenuation pattern is shown in stream sediments from mine to 0.75 km downstream, although these contain highly enriched U contents (24~83 mg/kg) comparing with the international average concentration of surface soils (0.79~11 mg/kg). However, U content increases abruptly in sediment at 1.5 km downstream, probably due to detrital migration and rediposition of U enriched sediments. Futhermore, enriched U in downstream sediments occur in high proportions of carbonate and Fe-Mn oxide bounded forms, which show high potential of a secondary pollution source. For aquatic organisms, bio accumulation degree of U are in the order: aquatic larvae>black snail>mountain frog>crawfish. Cultured trout by the U enrich groundwater (387 ${\mu}g$/l) shows U accumulation in the part of branchia (CRs 5.25) and bones (CRs 11.2) but not in flesh (CRs 0.03). Total a-radioactivity have been measured in the level as 0.47 nCi/l for groundwater, 2.94~18 nCi/kg${\cdot}$DW for organisms and 93~328 nCi/kg${\cdot}$DW for sediments.

• Communications for Statistical Applications and Methods
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• 제19권3호
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• pp.345-358
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• 2012

표본선택 모형을 최우추정법으로 추정할 때 오차항의 분포를 제대로 가정하는 것이 매우 중요하다. 표본선택 모형의 선택 방정식과 본 방정식의 오차항 분포를 일반적으로 이변량 정규분포로 가정하지만, 이 가정이 오차항의 실제 분포를 과도하게 제약할 가능성이 있다. 본 연구는 표본선택 모형의 오차항 분포로 $S_U$-정규분포를 도입한다. $S_U$-정규분포는 분포의 비대칭성과 초과첨도를 허용한다는 측면에서 정규분포보다 훨씬 유연하면서, 동시에 정규분포를 극한분포의 형태로 포함하고 있다. 또한 정규분포처럼 다변량 분포함수가 존재하기 때문에 표본선택 모형과 같은 다변량 모형에서도 활용할 수 있다. 본 논문은 $S_U$-정규분포를 이용한 표본선택 모형에서 로그우도 함수와 조건부 기댓값을 도출하고, 시뮬레이션을 통해 정규분포 모형과 추정성과를 비교한다. 또한 자동차 보유 가구들의 자동차 유지비에 관한 실제 데이터를 이용하여 $S_U$-정규분포 표본선택 모형의 추정결과를 제시한다.

• 대한수학회지
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• 제34권3호
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• pp.543-551
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• 1997

We prove a norm inequality of the form $\left\$\mid$ \upsilon \right\$\mid$ \leq (r - 1) \left\$\mid$ u \right\$\mid$_p, 1 < p < \infty$, between a non-negative subharmonic function u and a smooth function $\upsilon$ satisfying $$\mid$\upsilon(0)$\mid$ \leq u(0), $\mid$\nabla\upsilon$\mid$ \leq \nabla u$\mid$$ and $\mid$\Delta\upsilon$\mid$ \leq \alpha\Delta u$, where $\alpha$ is a constant with $0 \leq \alpha \leq 1$. This inequality extends Burkholder's inequality where $\alpha = 1$.