• 한국농촌건축학회논문집
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• 제21권2호
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• pp.1-10
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• 2019

This research aimed to identify characteristics of housing repairs for the weak class in rural area. Data are analyzed by the status according to year focusing on voluntary activity of the Korean Institute of Rural Architecture that is performing more than 10 years. The results are followings. First, approximately 63.3% of residents living in benefit houses are 70s and 80s in their age. They are weak in financial and physical and they have more than two weak points. Second, housing repairs were performed total 1,990 cases among 797 houses and average 2.5 cases per one house. Repair work in house interior is at the highest, the next is repair work in kitchen, repair work related to restroom, repair work for housing structure improvement, and repair work for insulation in order. Third, repair work required difficult work process and high cost is tend to decrease recently. However, work changing of wallpaper and papered floor and performing in outside is tend to increase because it has simple work process and low cost. Finally, barrier free needs to be more actively reflected for the weak class in rural area.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1999년도 하계학술대회 논문집 C
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• pp.1067-1069
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• 1999

This paper presents a network reduction using weak coupling method. Weak coupling method of identifying coherent generator groups are proposed. The partitioning technique used in this paper is based on a property of sparse matrix factorization. When a matrix has been factorized, a system is divided into study area, boundary buses and external area. A reduction process for external system starts with the load bus elimination and coherent generator aggregation. An identification of coherent generator group, network partitioning and network reduction are presented.

• 대한전자공학회논문지TC
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• 제48권10호
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• pp.13-19
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• 2011

이 논문은 위성항법시스템을 이용한 위치측위에서 지역별 특성에 따른 위치오차실험을 통하여, 음영지역 발생 원인과 해결 방법을 제안하기 위한 연구이다. 동적측위에서 이동체는 이동 위치에 따라 사용할 수 있는 위성항법시스템의 수가 변화한다. 정확한 위치측위를 위해서는 4개 이상의 위성항법시스템으로부터 위치정보데이터를 수신 받아야 한다. 하지만 급격한 산업화와 열악한 지역 환경으로 위치오차가 커지고 음영지역이 발생한다. 이러한 위치오차를 줄이고 음영지역 발생을 해소하기 위해서는 대도시의 환경과 지역 환경 특성에 따른 원인을 파악하는 것이 중요하다. 따라서 본 논문에서는 대도시, 주택 지역, 숲 지역, 바다 지역, 대지 등을 선정하여 위치오차와 음영지역 발생 원인을 실험하였다. 그리고 이 논문을 기반으로 지역 환경에 따른 적합한 고정밀 측위 알고리즘을 제안하고, 음영지역해소 알고리즘을 제안하려고 한다.

• Geomechanics and Engineering
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• 제11권1호
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• pp.41-58
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• 2016

This paper focuses on the deformation behavior of tunnels crossing a weak zone in conventional tunneling. A three-dimensional finite element model was adopted that allows realistic modeling of the tunnel excavation and the support installation. Using the 3D FE model, a parametric study was conducted on a number of tunneling cases with emphasis on the spatial characteristics of the weak zone such as the strike and dip angle, and on the initial stress state. The results of the analyses were thoroughly examined so that the three-dimensional tunnel displacements at the tunnel crown and the sidewalls can be related to the spatial characteristic of the weak zone as well as the initial stress state. The results indicate that the effectiveness of the absolute displacement monitoring data as early warning indicators depends strongly on the spatial characteristics of the weak zone. It is also shown that proper interpretation of the absolute monitoring data can provide not only early warning for a weak zone outside the excavation area but also information on the orientation and the extent of the weak zone. Practical implications of the findings are discussed.

• 한국대기환경학회지
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• 제9권2호
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• pp.168-173
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• 1993

Air quality impacts of point and area sources were analyzed by using ISCST2 with wind speed and stability class combinations of SCREEN. Stack height was important in determining the impact of point sources. With the stack height reduced to 21m from 75m, the concentration in the vicinity increased several times in spite of decreasing the emission rate by half. When the emission rates were same, concentrations from an area source of 10m release height were slightly lower than those from a point source of 21m stack height at the plume centerline. Bur the area source resulted in larger area of high concentration. Concentration from the point source was high in neutral to slightly unstable conditions with strong winds in a short distance, and in stable conditions with weak winds in a long distance. Concentration from the area source decreased with distance from the source, and was high in stable conditions with weak winds.

• 대한수학회지
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• 제60권1호
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• pp.33-69
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• 2023

Let α ∈ (0, ∞), p ∈ (0, ∞) and q(·) : ℝⁿ → [1, ∞) satisfy the globally log-Hölder continuity condition. We introduce the weak Herz-type Hardy spaces with variable exponents via the radial grand maximal operator and to give its maximal characterizations, we establish a version of the boundedness of the Hardy-Littlewood maximal operator M and the Fefferman-Stein vector-valued inequality on the weak Herz spaces with variable exponents. We also obtain the atomic and the molecular decompositions of the weak Herz-type Hardy spaces with variable exponents. As an application of the atomic decomposition we provide various equivalent characterizations of our spaces by means of the Lusin area function, the Littlewood-Paley g-function and the Littlewood-Paley $g^*_{\lambda}$-function.

• 한국농공학회논문집
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• 제47권6호
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• pp.47-57
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• 2005

Stress distribution in soils is the very important element to design and to solve the problems of settlement, safety of foundations and trafficability of constructing vehicle in civil engineering. This research presents the comparative estimation of the actual and theoretical measurement on the underground stress of outer layer for each soil after the observation of each top soil layer fur its vertical and horizontal stresses in (1) homogeneous sand ground (2) weak stratum with the sand soil (3) weak stratum with gravel of the soil model, and it also investigates the effect of subsidence of ground by the repeated load. The underground stresses fumed out to be different in the value of theoretical and actual measurement after the trial examination of model. This study has the purpose of suggesting the better construction method of running equipment on weak stratum by comparing the estimated value of trial experiment and theory on underground stress of the weak ground surface area and of raising up the necessity of the continuous research hereafter.

• 한국대기환경학회지
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• 제20권3호
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• pp.345-360
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• 2004

The late sea-breeze and its impacts on ozone distributions were investigated during April to September from 1998 to 2002, in the Busan metropolitan area (including surrounding areas) using the surface ozone concentrations (obtained at 9 monitoring sites), local meteorological variables (obtained near the shore), together with synoptic data. The urban scale ozone concentration was also simulated using the MM5/UAM-V to better understand the role of late sea-breeze in Busan. The results from observation study showed that most of the late sea-breeze occurred when weak offshore synoptic flow (northwesterly) suppressed development of sea - breeze, and the ozone concentration level and frequencies exceeding ozone standard increased with the onset time of sea breeze. We also found that the late sea-breeze clearly induces relatively weak wind speed and high temperature during the daytime As a result it enhances the photochemical ozone accumulation and delays the occurrence time of the averaged maximum ozone concentrations. The results of simulation for high ozone episode (24 August, 2001) by MM5/UAM -V revealed that the late sea-breeze interacted with weak offshore synoptic wind can contribute significantly to high ozone concentration in the coastal urban area. The simulated horizontal and vertical distribution of ozone concentration indicated that ozone can be accumulated over the sea under stagnant condition and return to the land in the late afternoon with the sea breeze, suggesting both the relationship between late sea-breeze and recirculation and the importance of late sea -breeze effects influencing severe ozone pollution in Busan.

• 분석과학
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• 제34권2호
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• pp.56-67
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• 2021

Due to the difficulty of grading visualized fingerprints with previously known evaluation methods for the comparison of split fingerprints, a preliminary study was performed with the densitometric image analysis (DIA) method as a potential quantitative and supplementary evaluation method. Each image of inked split fingerprints was divided into 4 zones for analysis. Weekly intra- and inter- analysis by two analysts with three whole fingerprints that were constructed by combining inked split fingerprints showed that the average area values and the ranges of difference fluctuation were not significantly different between strong fingerprints and strong-weak pairs, while they were different in weak fingerprints and weak-weak pairs. In the case of weak fingerprints, the exact acquisition of ridges was difficult and this seemed to influence the results. An additional study is needed for the improved reliability using DIA method with weak fingerprints such as 8 zones division rather than 4 zones. In addition, the analysis results performed by several analysts at different times should be used to improve the reliability of the analysis method further. Based on the above result, it can be judged that utilizing the DIA method as a secondary evaluation method of the existing scoring system would be effective with the additional studies especially on weak fingerprints.

• 한국측량학회지
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• 제34권4호
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• pp.403-411
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• 2016

This research has the purpose to develop a method to evaluate whether station’s area of influence has been formed, and verify formation of the area of influence through empirical analysis of all subway stations in Seoul. First, we created buffers of 100m intervals from 100m to 1000m, based on subway station exits, calculated the average land price of each buffer, and divided station areas of influence into 10 clusters using K-means clustering with the average land prices as values of observation. Subsequently, we have assumed a decreasing price curve from increasing distance from a nearby subway station, estimated a price curve and evaluated whether the area of influence actually exists using regression analysis of each cluster. The 10 area of influence clusters were largely divided into strong, weak, and no area of influence of subway station. The stations where the strong areas of influence are formed are mainly located in center, sub-centers, and local centers; stations where weak and no areas of influence are formed are mostly located in the adjacent areas of center or sub-centers or suburbs.