• The Korean Journal of Applied Statistics
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• v.23 no.5
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• pp.955-966
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• 2010

Canonical correlation biplot is a useful biplot for giving a graphical description of the data matrix which consists of the association between two sets of variables, for detecting patterns and displaying results found by more formal methods of analysis. Nevertheless, when some values are missing in data, most biplots are not directly applicable. To solve this problem, we estimate the missing data using the median, mean, EM algorithm and MCMC imputation methods according to missing rates. Even though we estimate the missing values of biplot of incomplete data, we have different shapes of biplots according to the imputation methods and missing rates. Therefore we use a RMS(root mean square) which was proposed by Shin et al. (2007) and PS(procrustes statistic) for measuring and comparing the shape variability between the original biplots and the estimated biplots.

• Korean Journal of Cognitive Science
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• v.13 no.3
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• pp.33-46
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• 2002

Recently, unstructured random data such as website logs, texts and tables etc, have been flooding in the internet. Among these unstructured data there are potentially very useful data such as bulletin boards and e-mails that are used for customer services and the output from search engines. Various text mining tools have been introduced to deal with those data. But most of them lack accuracy compared to traditional data mining tools that deal with structured data. Hence, it has been sought to find a way to apply data mining techniques to these text data. In this paper, we propose a text mining system which can incooperate existing data mining methods. We use text mining as a preprocessing tool to generate formatted data to be used as input to the data mining system. The output of the data mining system is used as feedback data to the text mining to guide further categorization. This feedback cycle can enhance the performance of the text mining in terms of accuracy. We apply this method to categorize web sites containing adult contents as well as illegal contents. The result shows improvements in categorization performance for previously ambiguous data.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.22 no.8
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• pp.1049-1054
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• 2018

Keyword searching used in the past as a method of finding similar patents, and automated classification by machine learning is using in recently. Keyword searching is a method of analyzing data that is formalized through data refinement. While the accuracy for short text is high, long one consisted of several words like as document that is not able to analyze the meaning contained in sentences. In semantic analysis level, the method of automatic classification is used to classify sentences composed of several words by unstructured data analysis. There was an attempt to find similar documents by combining the two methods. However, it have a problem in the algorithm w the methods of analysis are different ways to use simultaneous unstructured data and regular data. In this paper, we study the method of extracting keywords implied in the document and using the LDA(Latent Semantic Analysis) method to classify documents efficiently without human intervention and finding similar patents.

• Journal of the Institute of Electronics and Information Engineers
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• v.51 no.11
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• pp.83-93
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• 2014

It is a widespread concern that electrical interconnection based network-on-chip (NoC) will ultimately face the limitation in communication bandwidth, transmission latency and power consumption in the near future. With the development of silicon photonics technology, a hybrid optical network-on-chip (HONoC) which embraces both electrical- and optical interconnect, is emerging as a promising solution to overcome these problems. Today's leading edge systems-on-chips (SoCs) comprise heterogeneous many-cores for higher energy efficiency, therefore, extended study beyond regular topology based NoC is required. This paper proposes an energy and latency optimization topology design technique for HONoC taking into account the traffic characteristics of target applications. The proposed technique is implemented with genetic algorithm and simulation results show the reduction by 13.84% in power loss and 28.14% in average latency, respectively.

• Journal of KIISE:Databases
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• v.36 no.2
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• pp.63-72
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• 2009

Digital forensics refers to finding electronic evidences related to crimes. As cyber crimes are increasing daily, digital forensics for finding electronic evidences is also becoming important. At present, various aspects of digital forensics have being researched including the overall process model and analysis techniques such as network forensics, system forensics and database forensics for digital forensics. Regarding database forensics, only analysis techniques dependent on specific vendors have been suggested. And general process models and analysis techniques which can be used in various databases have not been studied. This paper proposes an integrated process model and analysis technique for database forensics. The proposed database forensics model (DFM) allows us to solve problems and analyze databases according to the situation and purpose, and to use a standard model and techniques for various database analyses. In order to test our model(DFM), we applied it to various database analyses. And we confirmed the results of our experiment that it can be applicable to acquisition in the scene as well as analysis of data relationships.

• Journal of KIISE:Software and Applications
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• v.32 no.9
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• pp.888-900
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• 2005

Several researches have been proposed to formalize the knowledge preconditions problem - j.e., an action or a plan is epistemically feasible. However, since the feasibility is only checked at design-time and is assumed that it will also 1)e feasible at run-time, it is not suitable in the context of Semantic Web services composition, where many agents should share the limited resources required for the execution of Web services composition. Therefore, in this paper, we formalize a transactionally executable Web services composition which enables to guarantee its atomicity. Moreover, in order to formalize the transactional executability, we propose $TL-ALCFK_{NF}$ which extends TL-ALCF with the modal operators K and A. Based on $TL-ALCFK_{NF}$, we show how to carry out the epistemic reasoning with TL-ALCF as a language to represent Semantic Web services composition.

• 한국벤처창업학회:학술대회논문집
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• 2018.11a
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• pp.187-192
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• 2018

현재 급변하는 정보기술, 다양성을 추구하는 시장의 니즈, 미리 예측하지 못한 다양한 형태의 경쟁자 등의 출현으로 인해 경영환경이 급변하고 있는 것은 더 이상 새로운 현상이라고 보기는 어렵다. 이와 같이 급변하는 경영 환경은 기업 간 경쟁 심화를 불러일으키고 있으며, 경쟁 심화는 생존 및 발전을 위해 기업 특성에 맞지 않는 무분별한 전략을 활용하면서 오히려 역효과를 내고 있다는 문제를 야기하고 있다. 특히 변화하고 있는 환경 내 벤처기업 및 창업기업들의 경우 창업 후 생존율이 점차 낮아지면서 일반 기업들에 비해 경쟁력을 갖춘 기업을 찾아보기 어려운 것이 현실이다. 이에 벤처기업들은 도태되지 않고 생존하기 위해경쟁력을 강화시킬 수 있는 다양한 전략을 구사하고 있다. 벤처기업은 하나의 비즈니스 생태계 내 유기적 생명체로서 진화하기 위해 제품이나 산업의 수명주기와 마찬가지로 창업기, 초기 성장기, 고도 성장기, 성숙기, 쇠퇴기 등의 정형화된 단계를 거친다. 따라서 벤처기업은 무차별적인 전략을 통해 기업의 생존 및 성장을 도모 하는 것이 아니라 해당 기업이 놓인 수명주기 단계별로 전략, 조직 구조, 의사결정방식, 통제유형 등을 상이하게 판단하고 이에 적절한 전략을 수행해야 한다. 예를 들어, 동일 생산요소를 투입하더라도 이를 적용할 수 있는 지식이 있는 경우 더 높은 가치 창출이 가능(Aghion & Howitt, 1992) 하지만 창업 초창기의 기업은 고도 성장기의 기업보다 보유한 지식 수준 및 경험이 상대적으로 낮기 때문에 다양한 협력을 필요로 한다. 그러나 현재의 여러 선행연구들은 기업이 처한 상황을 고려하지 않은 단편적인 대처 방안이거나 혹은 부분적인 방법론을 제공하는 수준에 그치고 있다는 한계가 있다(이병헌 외, 2014). 따라서 본 연구에서는 '2016년 벤처기업정밀실태조사' 데이터를 기반으로 기업의 외부 협력 정도 및 벤처기업 지원제도 활용 정도가 경쟁력과 성과에 미치는 영향이 기업의 수명주기별로 상이하다고 보고 관련 전략 프레임워크를 제시하고자 한다.

• Journal of the Korean Geotechnical Society
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• v.36 no.12
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• pp.69-76
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• 2020

Since the mechanically stabilized earth walls have a form of retaining wall compatible with a narrow section, the geogrid overlaps according to the separation distance between the walls. There is a problem that the overall behavior may occur in the state of being integrated with the stress change due to the interaction of the geogrid. Therefore, a careful approach is required at the design stage, but there are currently no design criteria or guidelines in Korea. This study investigated the optimal reinforcement length ratio according to the retaining wall width to height ratio (width to height ratio, Wb/H) for these back-to-back mechanically stabilized earth walls. Retaining wall width ratio is 1.1H, 1.4H, 1.7H, 2.0H for Case II of the FHWA design standard, and the height is 3.0 m, 5.0 m, 7.0 m, and 10.0 m, which are most commonly applied. Through numerical analysis, the appropriateness of the FHWA design standard and the optimal reinforcement length ratio according to the height of the retaining wall and the width of the retaining wall were proposed.

• Journal of the Korea Society of Computer and Information
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• v.28 no.4
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• pp.65-73
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• 2023

In this paper, we propose a data augmentation method based on CNN(Convolutional Neural Network) learning for efficiently obtaining concrete crack image datasets. Real concrete crack images are not only difficult to obtain due to their unstructured shape and complex patterns, but also may be exposed to dangerous situations when acquiring data. In this paper, we solve the problem of collecting datasets exposed to such situations efficiently in terms of cost and time by using vector and thickness-based data augmentation techniques. To demonstrate the effectiveness of the proposed method, experiments were conducted in various scenes using U-Net-based crack detection, and the performance was improved in all scenes when measured by IoU accuracy. When the concrete crack data was not augmented, the percentage of incorrect predictions was about 25%, but when the data was augmented by our method, the percentage of incorrect predictions was reduced to 3%.

• Proceedings of the Korean Society for Agricultural Machinery Conference
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• 2017.04a
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• pp.84-84
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• 2017

직립식 마늘파종기는 마늘 종구를 한 알씩 집어 올려 중간이송컵으로 이송하는 자세교정컵과 배종부와 자세교정컵에서 낙하된 마늘종구를 땅속으로 파종하는 구조로 설계 제작되었으며,전라북도 익산시에 테스트베드를 구축하여 기계파종을 통한 파종기의 성능개선연구를 수행하였다. 기계파종은 1차년도 기존 파종기의 성능을 개선한 7조식 시제품과, 국내산과 스페인산 마늘을 파종하였으며, 11조용 참여기업의 기존 파종기를 이용하여 테스트베드에서 수행하였다. 비가 온 뒤의 땅에 파종한 라인의 샘플링 자료조사 결과(5m 구간 기준으로 체크) 결주율이 각각 17.81%, 35.6%로 평균적인 결주율이 0.57%인 일반 기상상태와 비교하면 매우 높은 결주율을 보이는 것을 알 수 있다. 마늘 파종법에 대한 결과로, 총 4가지의 파종법을 사용하였으며, 사용한 파종방법에는 2조 병목식 스페인식 파종법, 11조식 트랙터용 파종법, 7조식 트랙터용 파종법, 6조식 이양기용 파종법이다. 이 4가지 파종법 중에서 3가지 파종법에 대한 성장률에 대해서 조사를 해보았다. 11조식의 경우에는 제주도식 파종을 하여 비닐 멀칭이 되어있지 않으며, 7조식의 경우에는 비닐 멀칭이 되어있는 파종방식을 사용하였고, 2조식 병목식 스페인식 파종법의 경우에는 자유낙하 방식으로 비닐 멀칭의 유무에 따라 성장률에 대해서 조사를 하였다. 결주율은 파종된 마늘 중 샘플링한 데이터에 대해서 얼마나 파종이 잘되었는지에 퍼센트로 나타낸 것으로 11조식의 경우 비닐멀칭도 없고 비온 뒤에 파종 되어 파종시기에 문제가 있는 것으로 사료됨. 비가오지 않은 날씨에서 측정한 7조식 1차년도 성능개선 시작품의 결주율은 0.57%로 우수하게 나타났다. 발아율은 파종된 마늘 중 샘플링한 데이터에 대해서 다립파종 되어서 미성장된 것과 결주율을 합하여 퍼센트로 나타낸 것으로 시제품으로 개발한 7조식 파종기는 스페인산과 국내산 마늘의 발아율이 모두 90% 이상으로 나타났으며, 차이점은 파종시기의 차이에 따라 발아율의 차이가 있는 것으로 사료(토양, 재배환경 및 기후에 따른 변동요인이 많음)되며, 이는 파종법의 종류뿐만 아니라 비닐멀칭의 온도유지가 마늘 성장률에 얼마나 영향을 끼치는지에 대한 병행연구도 필요한 것으로 나타났다. 마늘의 성장률에 대해서는 아직 표준화, 정형화 되어있는 측정방법이 없기 때문에 이를 표준화, 정형화를 할 필요가 있다. 향후 이와 같은 결과를 토대로 직립식 마늘파종기의 성능을 더욱 개선시키는 연구를 지속적으로 수행할 계획이다.