• 한국지구물리탐사학회:학술대회논문집
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• 2001.09a
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• pp.90-93
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• 2001

Various soil remedial technologies have been developed and main effort has been to overcome the limiting factors. Major factors were the geophysical characteristics, especially hydraulic, electrical, and heat conductivities. In this paper, I have reviewed the remedial technologies depending on those. Only with comprehensive understanding and information on those characteristics, selection of the best remedial method can be possible.

• Proceedings of the Korea Society for Industrial Systems Conference
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• 2003.11a
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• pp.747-752
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• 2003

많은 양의 유즈넷 뉴스 중에서 사용자가 찾고자 하는 정확한 정보를 빠른 시간 안에 검색하고, 원하는 정보만 필터링 하는 것은 중요하다. 그러나 뉴스 문서는 이메일과 달라서 미리 자신에게 맞는 뉴스그룹을 등록해 주어야만 정보를 얻을 수 있다. 본 연구에서는 다양한 뉴스그룹들 중에서 사용자와 취향이 가장 유사한 뉴스그룹을 분류하여 뉴스 문서의 키워드들을 선택하기 위해 예제 문서들로부터 후보 용어들을 추출하고 퍼지 추론을 적용하여 대표용어들을 선택한다. 이에 본 연구에서는 통계적인 결정계수를 도입하여 불필요한 차원을 제거한 후 신경망을 학습시키는 새로운 방법을 제안한다. 제안된 방법은 모든 차원을 활용할 때 보다 클러스터간 거리와 표준편차, 클러스터간 거리의 척도 면에서 우수한 분류 성능을 보여줌을 확인하였다.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2010.05a
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• pp.905-908
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• 2010

Our purpose is to develope the system which detects splogs automatically among blogs on Web environment. After removing HTML of blogs, they are tagged by part of speech(POS) tagger. Words and their POS tags information is used as a feature type. Among features, we select useful features with $x^2$ statistics and train the SVM with the selected features. Our system acquired 90.5% of F1 measure with SPLOG data set.

• Communications for Statistical Applications and Methods
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• v.15 no.3
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• pp.333-342
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• 2008

Variable selection theorem in the linear regression model is extended to the analysis of covariance model. When some of regression variables are omitted from the model, it reduces the variance of the estimators but introduces bias. Thus an appropriate balance between a biased model and one with large variances is recommended.

• Annual Conference of KIPS
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• 2010.04a
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• pp.463-466
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• 2010

길이가 긴 질의에는 검색에 불필요한 단어가 포함되어 있어서 사용자가 원하지 않는 문서가 검색결과에 포함된다. 질의에서 불필요한 단어를 제거하고 핵심 단어만 선택한다면 검색에 효율을 높일 수 있다. 본 논문에서는 질의 조합을 기반한 클러스터를 이용해 핵심 단어를 찾고 핵심 단어와의 근접도를 이용해 상위 문서의 정확율을 향상시키는 기법을 제안한다. 실험은 뉴스 집합인 TREC AP 문서를 검색한 결과를 제안한 알고리즘으로 재순위화하여 초기 검색 결과의 상위 문서의 정확율을 비교함으로써 제안된 알고리즘의 유효성을 검증한다.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.10 no.1
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• pp.42-48
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• 2006

In this paper a joint detection method for other cell interference cancellation is proposed in the next generation hybrid TD-CDMA mobile communication systems. A joint detection technique, a most characteristic feature of hybrid TD-CDMA mobile communication systems. retrieves users' data in the same time slot simultaneously with the elimination of multiple user interference. Previously a two stage joint detection method was proposed to cancel other cell interference as well as multiple user interference in the target cell. However the previous scheme does not have concrete ways to recognize other cell users who give major interference to the target cell. Thus all users in neighbor other cells has to be jointly detected and it causes huge complexity of the two stage joint detection. In this paper a method is proposed to perform two stage joint detection according to users' interference with the target cell. Performances of the proposed scheme are investigated through simulations and compared to the previous method the proposed method has no performance degradation and also lower the complexity of two stage joint detection significantly.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.12 no.6
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• pp.10-21
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• 2013

This study suggested combined filtering model to eliminate outlier travel time data in transportation information system, and it was based on Median Absolute Deviation and Voting Rule. This model applied Median Absolute Deviation (MAD) method to follow normal distribution as first filtering process. After that, Voting rule is applied to eliminate remaining outlier travel time data after Median Absolute Deviation. In Voting Rule, travel time samples are judged as outliers according to travel-time difference between sample data and mean data. Elimination or not of outliers are determined using a majority rule. In case study of national highway No. 3, combined filtering model selectively eliminated outliers only and could improve accuracy of estimated travel time.

• Resources Recycling
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• v.21 no.5
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• pp.50-57
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• 2012

A comparative study has been carried out on the removal of impurities such As, Sb, Bi from the copper sulfate solution by ion exchange resin containing aminophosphosphonic acid as functional group. The various parameters which affect the removal of impurities; such as the reaction temperature, the reaction time, the amount of ion-exchange resins, the concentration of sulfuric acid in electrolyte, were studied. The basic experimental results showed that about 88% of Sb & 94% of Bi can be adsorbed in these chelate resins and removed from the copper sulfate solutions but As was removed below 10% from the solutions. And the selective elution of Bi and Sb from the adsorbed ion exchange resin also can be achieved by $H_2SO_4$ or HCl solutions. The results also showed that 98.1% of Sb and 96.6% of Bi can be adsorbed from the copper sulfate solutions after 2 Bed-volume of continuous ion exchange column test.

• Analytical Science and Technology
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• v.15 no.1
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• pp.1-6
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• 2002

The selective removal of cesium by ammonium molybdophosphate (AMP) was studied in order to reduce an interference by high radioactivity of cesium on the determination of low radioactive elements in leachate of spent fuel. The removal of Cs, U, Ce, La, Co Ca, Na Sr and K was investigated for the leachate and the bentonite in contact with a spent fuel. More than 90% of cesium was removed by AMP and Ca, Na, Co and Sr was remained in 0.1 M $HNO_3$. However, three valence elements such as La and Ce were also removed by AMP. Though a little of potassium of the bentonite components was adsorbed on AMP, the potassium in the bentonite solution diluted to its concentration in a real sample would not affect the capacity of AMP greatly. From another experiment for the separation of strontium as a leaching indicator of spent fuel, the recovery of strontium in 8.0 M $HNO_3$ solution by using Sr-resin (Eichrom, P/N SR-B50-A) was more than 95% by eluting with 0.05 M $HNO_3$.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.10 no.4
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• pp.830-837
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• 2009

In this thesis, Multi-code/Multi-carrier CDMA(MC/MC CDMA) system which is combination of Multi-code CDMA and Multi-carrier CDMA is analyzed. This system is suitable fur multi-rate services that use multi-codes and high data rate transmission that employ multi-carriers. In addition, the MC/MC CDMA system is robust against frequency selective fading, is good for narrowband interference rejection, and has higher spectral efficiency. In this paper, The users are assigned OVSF codes as a spreading code according to their data rates and divides the active users having different representative code split into a number of groups for effective cancellation. At the receiver, The code grouping interference canceller performs cancellation between the groups. The proposed receiver does not require any information about interference users, such as code, data and amplitude, and has relatively low complexity. The results show the large improvement in performance that can be attained by cancellation scheme.