• Journal of KIISE:Software and Applications
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• v.31 no.12
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• pp.1684-1690
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• 2004

This paper presents a method for classifier selection that uses distribution information of the training samples in a small region surrounding a sample. The conventional DCS-LA(Dynamic Classifier Selection - Local Accuracy) selects a classifier dynamically by comparing the local accuracy of each classifier at the test time, which inevitably requires long classification time. On the other hand, in the proposed approach, the best classifier in a local region is stored in the FSA(Feature Space Attribute) table during the training time, and the test is done by just referring to the table. Therefore, this approach enables fast classification because classification is not needed during test. Two feature space attributes are used entropy and density of k training samples around each sample. Each sample in the feature space is mapped into a point in the attribute space made by two attributes. The attribute space is divided into regular rectangular cells in which the local accuracy of each classifier is appended. The cells with associated local accuracy comprise the FSA table. During test, when a test sample is applied, the cell to which the test sample belongs is determined first by calculating the two attributes, and then, the most accurate classifier is chosen from the FSA table. To show the effectiveness of the proposed algorithm, it is compared with the conventional DCS -LA using the Elena database. The experiments show that the accuracy of the proposed algorithm is almost same as DCS-LA, but the classification time is about four times faster than that.

• Journal of Korean Tunnelling and Underground Space Association
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• v.19 no.3
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• pp.475-488
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• 2017

Wear prediction of TBM disc cutters is a very important issue for hard rock TBMs as number of cutter head intervention. In this regard, some model such as NTNU, Gehring model, CSM models have been used to predict disc cutter wear and intervention interval. There are some deficiencies in these models. This paper developed a new test method for wear prediction for TBM disc cutter and proposed a new abrasion index. In this regard, different abrasivity indices along with their testing methods are explained. A comparative study is performed to develop the predictability of different cutter life evaluation methods and index. The evaluation of the new methods proposed in this paper shows a very good agreement with the actual cutter life and intervention interval length. The proposed tester and index can be easily used to predict the intervention interval length and cutter wear evaluation in both planning and construction stages of a TBM tunneling project.

• Journal of Korean Tunnelling and Underground Space Association
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• v.18 no.5
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• pp.431-439
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• 2016

This paper dealt with contents of the quality evaluation method of lattice girder utilizing non-destructive method. Quality evaluation of ordinary lattice girder is performed through the tensile strength test of structural steel and visual inspection. The tensile strength test of structural steel is performed by collecting samples of lattice girder brought into the site, during which lattice girder must be damaged to obtain sample. In addition to such disadvantage, tensile strength tester is not available at the site in most cases, requiring an inconvenient service from test certification agency. In addition, it is substituted by mile sheet issued during the production of structural steel, which inevitably lacks reliability. Furthermore, visual inspection at the site entails a problem of lack of reliability, thereby requiring a method of easily and quickly evaluating the quality of lattice girder without damaging the material. Accordingly, this study comparatively analyzed the yield strength of tensile strength test and the yield strength of instrumented indentation test with same sample. The test results ensured over 95% precision level for the instrumented indentation test, based on which a quality evaluation method based on instrumented indentation test that allowed onsite direct quality evaluation is proposed.

• The Journal of the Korea Contents Association
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• v.15 no.12
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• pp.121-128
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• 2015

This study analyzes the space in A Brighter Summer Day, covering the meaning of space from inside to outside of the film extended. A violent spaces in the inside causes Xiao Si'r's homicide, including society, house, and school. In the external space, the film's form presents director's attitude and will resisting against dominant system of society with an audience's space. The audience join the space being the director's intention, actively interpreting this film, doing self-reflection and taking an opportunity for social participation.

• Journal of the Korean Geotechnical Society
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• v.22 no.1
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• pp.5-14
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• 2006

A simple and useful plane strain testing device was newly developed and its mechanical features were presented in this paper. The new testing device was designed to be capable of testing various stress paths expected under plane strain condition with only the conventional triaxial loading system. The applicability of the new testing device was systematically checked both by theoretical evaluation and by experiments. As a result, it was found that the new testing device has much wider range of application than the conventional plane strain testing devices.

• Proceedings of the KSRS Conference
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• 2009.03a
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• pp.181-185
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• 2009

Web 2.0 패러다임이 공간정보 처리분야에서 정착되면서 국내외에서 웹 기반의 다양한 공간정보 콘텐츠 서비스가 개발되고 활용되고 있다. 또한 새로운 기술발전 추세에 따라 다양한 공간정보를 효과적으로 처리하기 위한 사용자 중심의 인터페이스 개발도 중요한 연구 주제로 간주되고 있다. 본 연구에서는 현재 KML과 같이 제한적인 웹 표준 공간정보 자료 구조를 주로 다루는 클라이언트 기반의 Web 2.0 웹 컴퓨팅 기법을 보다 확장하여 미들웨어와 연동시키는 계층적 웹 서비스 구조를 설계하고 이를 기반으로 시험구현을 하고자 한다. 본 연구에 적용된 미들웨어는 공개 소스로 제공되는 Deegree를 적용하였으며 클라이언트 모듈 처리는 Google Maps API에서 제공되는 기만 클래스를 채택하였다. 공개 소스 및 공개 API을 적용한 웹 GIS 개발은 시스템 확장성이나 추가 개발에 대한 접근이 용이하므로 수요자의 요구 사항에 즉시 대응할 수 있다는 주요 장점이 있고 본 연구 결과에서도 이러한 점을 강조하고자 한다. 또한 본 연구의 결과인 Geo-Browser는 OQC의 다양한 GIS 국제 표준을 바로 지원하므로 사용자가 기존에 사용하고 있는 GIS 엔진이나 응용 프로그램과도 연동이 가능한 구조로 설계하였다.

• Tunnel and Underground Space
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• v.10 no.2
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• pp.211-217
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• 2000

In this, study, some laboratory tests and in-situ test were performed for Taegu area. Test blasting was conducted to determine blasting vibration coefficients. The uniaxial strength of rocks vary widely from weathered rock to extremely hard rock. Boasting vibration coefficient, K and n were 114.8, 1.48 for Sungseu site, where rocks show weathered to medium strength.

• Explosives and Blasting
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• v.19 no.1
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• pp.53-62
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• 2001

주변 보안물건에 직전각인 피해를 유발시킬 수 있는 발파진동은 암반의 파쇄를 위해 화약의 폭박력을 이용하는 발파작업에서 발생하는 대표적인 발파공해로 이러한 발파진동을 저감시키기 위한 많은 연구들이 수행된 바 있다. 본 연구에서는 2자유면 발파시 최소저항선과 대구경 무장약공을 자유면으로 활용하는 터널 심발발파시 무장약공과 첫 번째 심발발파공의 중심사이 거리가 발파진동에 영향을 정량적으로 평가하기 위해 균질한 모르타르 시험체에 대한 소규모 단일공 시험발파를 수행하였다. 11g의 화약을 장약한 2자유면 단일공 시험발파시 발파진동의 크기는 최소저항선을 표준장약의 경우인 150mm에서 2/3 수준인 100mm로 줄인 경우 삼승근 환산거리 $10~40{\;}m/kg^{1/3}$인 범위에서 약 13~38% 작아지는 것으로 나타났다. 또한 직경이 180mm인 무장약공을 자유면으로 활용하는 첫 번째 심발 시험발파공에 22g의 화약을 장약하여 수행한 단일공 시험발파시 무장 약공 중심으로부터 발파공 중심까지의 공간격이 짧아질수록 발파진동이 더 작아지는 것으로 나타났다.

• Tunnel and Underground Space
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• v.19 no.5
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• pp.450-462
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• 2009

To analyze the behavioral characteristics of rocks on indirect tests and uniaxial compressive strength, researchers have investigated 1417 pieces of rock block, which include igneous, metamorphic and sedimentary rocks in Korea. The same behavioral characteristics have been shown in every type of sedimentary rock and in the same species of rock in the case of Brazilian strength application. This suggests that correlations of rocks for geological considerations can lead to high reliability of the experimental results in case of an indirect method.

• Proceedings of the Korea Institute of Fire Science and Engineering Conference
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• 2010.04a
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• pp.141-146
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• 2010

특수선(FPSO, Drillship)의 거주구역이나, 대형 여객선(크루즈선) 공간의 70% 이상을 차지하는 수용시설(accommodation) 즉, 객실, 라운지, 공공장소, 창고 등은 24시간 사람이 상주하는 구역임으로 화재로부터 완벽하게 보호되어야 한다. 이를 위해 국제해사기구(IMO)에서는 SOLAS II-2 Reg. 10.6과 FSS code Ch. 8에 적합한 미분무수 소화설비를 설치할 것을 강제화하고 있다. 이러한 미분무수 소화설비는 미분무수 노즐, 압력용기, 섹션밸브, 펌프유닛 등으로 구성되는데 특히 핵심부품인 미분무수 노즐은 IMO Res. MSC 265(84)에 따라 노즐성능시험 및 화재진압성능시험을 통해 형식승인을 득해야 한다. 본 연구에서 이러한 기준에 만족하는 미분무수 노즐을 개발하고자 선실 및 복도에 대한 화재시험에 이어 공공장소 화재시험을 수행하였으며, 두 가지 천장 높이에 대한 화재진압성능을 평가하였다.