• The Journal of Korean Institute of Communications and Information Sciences
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• v.34 no.8C
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• pp.731-741
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• 2009

Optical repeater is often installed at the isolated area. Spatial separation makes it possible to reduce the inter-code interference when secondary scrambling codes are used for traffic connected through repeater. In this paper, we propose five secondary scrambling code usage scenarios with the aids of optical repeater to maximize the user capacity. In order to evaluate the performance, dynamic system level simulation is performed. We also propose a base station-repeater switching where each active users can change access points by comparing the channel condition from base station and repeater thorough secondary common pilot channel (S-CPICH) signal to noise-interference ratio (SINR). Moreover, primary-secondary scramble code replacing scheme is proposed which replaces secondary scramble code with primary scramble code when a call using primary scramble code is ended and its corresponding OVSF code is available to users using the secondary scramble code

• Journal of the Korean Institute of Intelligent Systems
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• v.15 no.7
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• pp.875-880
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• 2005

OWL(Web Ontology Language) is the Ontology Standard Language and the a lot of Ontologies are being constructed in OWL. But the research on the extension of OWL is also progressing because of the limit of representation power of in OWL language. The W3C suggests the SWRL(Semantic Web Rule Language) based on the combination of OWL and RuleML(Rule Markup Language), which is improved in the representation of rule. Thus, both OWL and SWRL are used for developing ontologies. However, research on inference of ontologies written in both languages is just begun. These day, for the inference of ontologies written in both languages, ontologies and divided in to two parts. The part written in OWL and written in SWRL. For the inference of the part written in OWL, Racer, a DL based inference engine, is used and for the other part Jess, a rule-based engine, is used. In this paper, we will propose three methods for integrated inference of the OWL part and the SWRL part of ontologies using Jess and some tools for ontology inference : OWLJessKB and SWRL Factory

• Journal of the Korean Institute of Intelligent Systems
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• v.19 no.4
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• pp.525-531
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• 2009

Data mining is the process of extracting hidden patterns from collected data. At this time, for collected data which take important role as the basic information for prediction and recommendation, the process to discriminate incorrect data in order to enhance the performance of analysis result, is needed. The existing methods to discriminate unexpected data from collected data, mainly relies on methods which are based on statistics or simple distance between data. However, for these methods, the problematic point that even meaningful data could be excluded from analysis due that the environment and characteristic of the relevant data are not considered, exists. This study proposes a method to endow human heuristic knowledge with weight value through the comparison between collected data and human heuristic knowledge, and to use the value for creating a decision tree. The data discrimination by the method proposed is more credible as human knowledge is reflected in the created tree. The validity of the proposed method is verified through an experiment.

• Proceedings of the Korean Institute of Intelligent Systems Conference
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• 2008.04a
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• pp.243-246
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• 2008

ISM(Industrial, Scientific, Medical)대역은 비면허 대역으로 일정한 출력 규제만 지키면 자유롭게 사용할 수 있다는 장점으로 인하여 육상 통신뿐만 아니라 해상 통신 영역까지 그 사용량이 급증하고 있다. 이에 어선 내에서 사용하는 전파응용설비 및 ISM대역을 사용하는 소출력무선기기 등과의 전파간섭 문제는 시스템의 안정성을 열화시킬 수 있는 요인이 되며, 선박상황을 고려하면 안전성과 직결되므로, 간과되지 말아야 한다. 따라서 ISM대역에서 사용되거나 사용될 무선설비의 간섭확률 분석은 필수적이다. 본 논문에서는 Monte-Carlo 방식을 기반으로 하는 SEAMCAT를 이용하여 거리 및 밀도에 따른 간섭 시나리오와 전파 간섭 simulation methodology를 제안하였으며, 해상에서 환경을 가정하여 다른 전파간섭을 배제하였다. 제안된 시나리오를 적용하여 13.56MHz ISM 대역의 거리 시나리오 시뮬레이션 결과 RFID는 4.7m 이상, 모형기기는 2.7m 이상의 동종 기기간 이격거리를 가질 경우 간섭 영향이 양호하였다. 밀도 시나리오 시뮬레이션 결과 RFID(${V_r}$)를 중심으로 간섭 영향권에 RFID와 모형기기가 각각 2개 이하, 모형기기(${V_r}$)를 중심으로 간섭 영향권에 모형기기 2개 이하, RFID 1개 이하로 사용될 경우 통신환경이 양호함을 알 수 있었다. 제안된 간섭 시나리오 및 시뮬레이션 기법은 향후 ISM대역의 규제 정책 및 간섭확률 분석에 기여할 것으로 기대된다.

• Journal of the Korean Society of Hazard Mitigation
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• v.4 no.3 s.14
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• pp.9-17
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• 2004

In recent years slope failure due to heavy rainfalls or local downpours usually accompanied by typhoons has increasingly occurred in Korea. Also, the damages caused by slope failure have a tendency to be more disastrous than before. This study has been conducted to prepare an early warning system for slope failure by : (1) analyzing types and causes of slope failure, (2) examining the published evaluation criteria for slope stability, (3) estimating slope stability by considering the properties of slope-forming materials as well as the topographical and geological properties of slopes, and (4) determining the most important variables of affecting the stability of the slope under consideration. The data on the variations of slope conditions measured by an automatic in-situ measurement system and then transmitted to the central analysis system by using an internet. The most important variables can be back-calculated in the central system and compared with the values for the first and second management criteria. These management criteria should be modified and corrected continuously in the future by accumulated data and knowledge related to the early warning system for slope failure.

• Proceedings of the Korean Society of Soil and Groundwater Environment Conference
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• 1996.05a
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• pp.15-33
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• 1996

우리나라의 토양은 지형적인 요인과 토양모재 및 기후적인 조건에 의해 토양에 유입되는 유해물질에 대한 보유력이 낮은 특성으로 인해 외부에서 유입되는 유해 중금속에 대하여 취약한 특성을 가지고 있다. 우리나라 토양의 중금속 자연 함유량은 논토양의 경우 Cd 0.13, Cu 4.15, Pb 4.17, Zn 3.95 mg/kg의 수준이며 밭토양은 Cd 함량이 논토양보다 높은 수치를 보인다. 과수토양은 과거에 중금속이 함유된 영농자재가 투입된 결과로 자연함량을 결정하기 힘드며 매우 높은 중금속 농도를 보인다. 그리고 현재 토양환경보전법이 시행되어 중금속류 및 유해유기물에 대한 오염기준을 제시하고 있다. 토양의 중금속 오염현황은 환경부의 토양오염 측정망에서 금속광산, 제련소, 매립지 부근에서 높은 농도를 나타내고 있으며, 산업폐수 및 생활하수가 관개수로 유입되는 논토양에서 중금속 오염이 우려되고 있다. 제련소 및 금속광산 부근의 토양은 거리에 따라 중금속 농도가 감소하는 경향을 보이고 있으나 인접지역에서는 규제농도에 육박하거나 초과하고 있다. 또한 폐광산 부근에서 생산된 현미 역시 전반적으로 작물재배제한 기준를 초과하지는 않으나 상당 지역이 이 기준을 초과하고 있으며 0.1 M HCl로 침출가능한 Cd 함량과 상관관계를 보인다. 이 상관관계에 의하면 0.1 M HCl로 침출가능한 토양 중 Cd의 양이 5 mg/kg 이면 생산된 현미의 Cd 함량이 1 mg/kg을 초과할 확률은 40%인 반면, 일본 식량청 수거대상인 0.4 mg/kg을 초과할 가능성은 100%로 파악된다. 광명시 가학광산 인근 지역을 대상으로 한 중금속 오염에 대한 대책연구에서는 현미 중 Cd 함량이 0.4 mg/kg을 초과할 가능성이 높은 지역(토양 농도 5 mg/kg)은 최소 20 cm 이상 두께로 객토를 하고, 현미 중 Cd 함량이 0.4 mg/kg 을 초과할 가능성이 낮은 지역은 석회, 규산질 비료, 용성인비, 등을 사용하여 중금속의 용해도를 낮추어 작물이행을 경시키는 것이 바람직한 것으로 판단되었다. 그리고 광미사를 현위치에서 처리하는 방안이 제시되었다.

• Proceedings of the Korean Society of Surveying, Geodesy, Photogrammetry, and Cartography Conference
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• 2005.11a
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• pp.81-104
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• 2005

Accurate 3D models in urban areas are essential for a variety of applications, such as virtual visualization, CIS, and mobile communications. LiDAR(Light Detection and Ranging) is a relatively new technology for directly obtaining 3D points. Because Manual 3D data reconstruction from LiDAR data is very costly and time consuming, many researchs is focused on the automatic extraction of the useful data. In this paper, we classified ground and non-ground points data from LiDAR data by using filtering, and we reconstructed the DTM(Digital Terrain Model) using ground points data, buildings using nonground points data. After the reconstruction, we assessed the accuracy of the DTM and buildings. As a result of, DTM from LiDAR data were 0.16m and 0.59m in high raised apartments areas and low house areas respectively, and buildings were matched with the accuracy of a l/5,000 digital map.

• Fire Science and Engineering
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• v.29 no.6
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• pp.6-12
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• 2015

This study used CONTAM modeling to analyzed analyze the stack effect in high-rise buildings for the terrain and weather conditions of Seoul and Jeju. The differential pressure caused by the stack effect is a function of the indoor and outdoor temperature difference and the height of the vertical shaft. Jeju is considered more stable than Seoul, because it is warmer than Seoul in winter. The differential pressure in Jeju is about 60% that of Seoul in for the same height of buildings in winter. However, Jeju is an island and the neutral plane is raised by over 56% by strong winds, although there is less differential pressure caused by the stack effect in Jeju than in Seoul. Due to the raised neutral plane, the region and magnitude of negative pressure in the lower part is larger in Jeju than in Seoul.

• Journal of Korea Water Resources Association
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• v.40 no.1 s.174
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• pp.25-38
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• 2007

A grid-based urban surface runoff model for simulating the temporal variation and spatial distribution of overland flow in a drainage area was developed. The process of routing of overland flow is modeled by the nonlinear storage equation which is composed of the continuity equation and the Manning's equation. For model operation, the drainage area is divided into grid areas, and spatially distributed topographical and hydrological information for model inputs is provided. Then overland flow is routed for each of the discretized cells of the area. In order to test the applicability of this model, temporal variations and spatial distributions of flow depth and overland flow was simulated in a fictitious and a real urbanized Kunja drainage area. Results indicate that the model can simulate reasonably well the urban runoff hydrograph.

• Journal of Korea Water Resources Association
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• v.32 no.3
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• pp.291-300
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• 1999

The Snyder's synthetic unit hydrograph method is selected to apply the concept of the fractal dimension by stream order for the practicable rainfall-runoff generation, and fourth types of the Snyder's relation are derived from topographic and observed unit hydrograph data of twenty-nine basins. As a result of the analysis of twenty-nine basins and the verification of two basins, the Snyder's relation which considers the fractal dimension of the stream length and uses calculated unit hydrograph data shows the best result. The concept of the fractal dimension by stream order is applied to the Snyder's synthetic unit hydrograph method. The topographic factors, used in the Snyder's synthetic unit hydrograph method, which have a property of the stream length like $L_{ma}$ (mainstream length) and $L_{ca}$ (length along the mainstream to a point nearest the watershed centroid) were considered. In order to simplify the fractal property of stream length, it is supposed that $L_{ma}$ has not the fractal dimension and the stream length between $L_{ma}$ and ($L_{ma}\;-\;L_{ca}$) has the fractal dimension of 1.027. From the utilization of this supposition, a new Snyder's relation which consider the fractal dimension of the stream length occurred by the map scale used was finally suggested.