• Proceedings of the Korea Water Resources Association Conference
• /
• 2009.05a
• /
• pp.2153-2157
• /
• 2009

도시하천은 Eco-network의 근간이며, 하천을 통해 인간이 느낄 수 있는 정서적인 안정감, 친밀감, 쾌적함 등 어메니티의 모체로서, 최근 도심내 Open space로서의 위상을 높여가고 있다. 양재천을 위시하여 수원천, 전주천 등 지역을 대표하는 하천들이 자연형 하천으로 정비되어 하천 이용에의 관심이 고조되고, 청계천의 성공을 기점으로 하천의 친수공간으로서의 기능이 강조됨에 따라 도시하천에 대한 개발 요구도는 급속히 높아지게 되었다. 이러한 개발요구의 급속한 증가가 있음에도 불구하고 보전과 이용이 상충하는 도시하천의 어메니티 향상을 위한 기준은 마련되지 않고, 일부 하천에서 이용과 관리의 효율성을 고려하지 않은 무분별한 개발을 부추기게 되어, 오히려 어메니티 향상의 측면에서는 부정적인 결과를 초래하였다. 따라서 본 연구에서는 하천 특성에 적합한 어메니티 도입 기준을 설정하기 위하여 하천의 규모, 자연도, 이용지수를 기준으로 하천유형을 분류하였으며, 이를 바탕으로 지속적인 연구를 진행하여 선진사례와 국내하천조사를 통해 지표요소를 분석하고, 분석된 지표요소에 따라 유형을 추출해내는 과정을 통해 하천유형과 활동유형, 도입시설간의 관계를 설정하여 도시하천 어메니티 향상을 위한 기준으로서 하천복원모델(안)을 제시하고자 한다.

• The Journal of the Institute of Internet, Broadcasting and Communication
• /
• v.12 no.6
• /
• pp.155-164
• /
• 2012

The compression of software development schedule has a limit without regarding to a development manpower. However, the actually developed softwares includes the impossible short time or unreal long time date. Previously suggested models are driving the development schedule from all of the actually developed software without considering these constraints. This paper recommends a standard of minimum and the most suitable development time period. This paper has chosen a criterion that shows the best development schedule among 5 criteria based on the actually performed projects. Moreover, this paper suggests a model that estimates the development schedule based on the best criterion.

• The Journal of the Institute of Internet, Broadcasting and Communication
• /
• v.11 no.5
• /
• pp.139-144
• /
• 2011

Most real world system such as world economy, management, medical and engineering applications contain a series of complex phenomena. One of common methods to understand these system is to build a model and analyze the behavior of the system. As a first step, Determining the best clusters on data. As a second step, Determining the model of the cluster. In this paper, we investigated heuristic search methods for efficient clustering. It is also confirmed that the Bayesian Information Criterion more reliable than Cheeseman-Stutz ones.

• Journal of Korean Society for Geospatial Information Science
• /
• v.16 no.1
• /
• pp.43-48
• /
• 2008

In this study, it was estimated efficiency of GPS/INS photogrammetry by comparison of accuracy and economical efficiency between conventional aerial triangulation and GPS/INS aerial triangulation at the base of large scale digital mapping using GPS/INS aerial survey. The results of aerial triangulation with GPS/INS showed that 40% of working amount was reduced in the process of ground control point survey compared to conventional aerial triangulation. In case of 1/5000 scale aerial triangulation, the results showed that 55% GCP work was reduced in 10 and 20 block size, and 60% GCP work was reduced in 30 block size, under the assumption of keeping the same accuracy.

• Proceedings of the Korean Institute Of Construction Engineering and Management
• /
• 2008.11a
• /
• pp.445-448
• /
• 2008

This study attempts to estimate approximate cost on construction of PSC BEAM Bridge using Case-Based Reasoning and suggests approximate estimation model at the planning and design stage. This paper suggests phased influence factors on construction cost and approximate estimation model for integrated project cost management.

• The Bulletin of The Korean Astronomical Society
• /
• v.37 no.2
• /
• pp.138.1-138.1
• /
• 2012

자기 구름은 자기 구조를 가지고 방출된 CME로 지구 자기장에 영향을 주는 중요한 원인 중 하나이다. 지구 자기장의 교란으로 발생하는 지자기 활동은 K 지수로 표현되는데 우주기상을 연구하는데 기본 자료로 활용된다. 따라서 자기 구름은 우주기상을 연구하는데 필요한 자료라 할 수 있다. 기존에 Lynch et al.(2005), Huttunen et al.(2005), Lepping et al.(2006), Feng et al.(2007) 등이 만든 자기 구름 리스트가 있지만 자기 구름에 적합하지 않는 이벤트가 적지 않게 포함되어 있어 이벤트를 지자기 활동 연구에 활용하기에 어려움이 있었다. 이 연구에서는 우리만의 자기 구름 기준을 정하고, 이 기준과 실린더 모델을 이용해 새로운 자기 구름 리스트를 완성하였다. 우리가 정한 자기 구름 기준은 (1)자기장의 벡터 성분이 천천히 회전하고 (2)자기장의 세기가 평균보다 세며 (3)자기 구름 지속시간이 7시간보다 짧은 이벤트도 모두 포함하는 것이다. ACE위성과 WIND 위성이 2000년에 관측한 행성간 자기장 자료에 우리의 자기 구름 기준을 적용하여 자기 구름 이벤트 후보를 선정하였고, 마루바시 박사가 만든 실린더 모델을 자기 구름 이벤트 후보에 적용하여 자기 구름 이벤트를 최종 선정하였다. 이렇게 선정된 2000년도 자기 구름 이벤트는 총 63개이고 이를 리스트로 작성하였다. 우리가 만든 자기 구름 이벤트 리스트는 CME와 K 지수 등 지자기 활동 연구에 활용되고 있다.

• Journal of the Korean Geophysical Society
• /
• v.9 no.2
• /
• pp.87-97
• /
• 2006

LIDAR(Light Detection and Ranging) is a new technology for obtaining DEM(Digital Elevation Model)ewith high density and high point acuracy. As LIDAR emerged, DEM could be developed in the earthsurface more efficiently and more economically, compared to the conventional aerial photogrametry.In this study, a digital camera is simultaneously used in combined LIDAR surveying, and acquired digitial image and DEM produce digital orthoimage. In this process, methods of combining sensor andorthoimage, GCPs determined by GPS surveying are used. Two digital orthoimage are produced; onewith a few GCP and the other without them. The produced maps can be used to corect or revised1:1,000 or 1:5,000 scale maps acordingly.

• Transactions of the Korean Society of Mechanical Engineers B
• /
• v.35 no.12
• /
• pp.1351-1358
• /
• 2011

To approximate the threshold of the fault detection and diagnosis (FDD) system, validation of the measurements is mandatory. Naturally, the system shows uncertainties due to measuring sensors - mostly thermocouples or RTDs - and due to repeatability. The uncertainty of a thermocouple comes from natural variation or a drift of the thermocouple measurement. Considering the natural variation behaves like zero-mean white noise, its natural variation can be characterized closely by the steady-state standard deviation. However, residuals between measurements and no-fault references in FDD systems show a statistical distribution with various uncertainties. In this paper, steady-state variations of measurement residuals were investigated by utilizing built-in temperature sensors in a heat pump for the model development and the final application.

• The Journal of the Korea Contents Association
• /
• v.7 no.6
• /
• pp.22-30
• /
• 2007

Most real word systems such as world economy, stock market, and medical applications, contain a series of dynamic and complex phenomena. One of common methods to understand these systems is to build a model and analyze the behavior of the system. In this paper, we investigated methods for best clustering over time series data. As a first step for clustering, BIC (Bayesian Information Criterion) approximation is used to determine the number of clusters. A search technique to improve clustering efficiency is also suggested by analyzing the relationship between data size and BIC values. For clustering, two methods, model-based and similarity based methods, are analyzed and compared. A number of experiments have been performed to check its validity using real data(stock price). BIC approximation measure has been confirmed that it suggests best number of clusters through experiments provided that the number of data is relatively large. It is also confirmed that the model-based clustering produces more reliable clustering than similarity based ones.

• Journal of the Korea Concrete Institute
• /
• v.23 no.3
• /
• pp.365-376
• /
• 2011

The current Concrete Structural Design Code (2007) prescribe the equivalent rectangular stress block of the ACI 318 Building Code as concrete compressive stress distribution for design of concrete structures. The rectangular stress block may be enough for flexural strength calculation, but realistic stress-strain relationship is required for performance verification at selected limit state in performance-based design. Moreover, the ACI rectangular stress block provides non-conservative flexural strength for high strength concrete columns. Therefore a new stress distribution model is required for development of performance-based design code. This paper proposes a concrete compressive stress-strain distribution model for design and performance verification. The proposed model has a parabolic-rectangular shape, which is adopted by Eurocode 2 and Japanese Code (JSCE). It was developed by investigation of experimental test results conducted by the authors and other researchers. The test results cover high strength concrete as well as normal strength concrete. The stress distribution parameters of the proposed models are compared to those of the ACI 318 Building Code, Eurocode 2, Japanese Code (JSCE) and Canadian Code (CSA) as well as the test results.