• ETRI Journal
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• 제43권4호
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• pp.694-701
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• 2021

Catastrophic events cause casualties, damage property, and lead to huge social impacts. To build common standards and facilitate international communications regarding disasters, the relevant authorities in social management rank them in subjectively imposed terms such as direct economic losses and loss of life. Terrorist attacks involving uncertain human factors, which are roughly graded based on the rule of property damage, are even more difficult to interpret and assess. In this paper, we collected 114 183 open-source records of terrorist attacks and used a machine learning method to grade them synthetically in an automatic and objective way. No subjective claims or personal preferences were involved in the grading, and each derived common factor contains the comprehensive and rich information of many variables. Our work presents a new automatic ranking approach and is suitable for a broad range of gradation problems. Furthermore, we can use this model to grade all such attacks globally and visualize them to provide new insights.

• 인문언어
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• 제1권2호
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• pp.123-139
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• 2001

In the history of linguistics in the world the scholars in India could be regarded as the representative linguists, who had provided the cornerstone of the academic development at linguistics. Without looking into the contents of Indian linguistic theories devised and developed in the past it would be almost impossible to account for the origin of descriptive linguistics and historical linguistics. These linguistics trends became full-fledged in 19 and 20 century and are still accepted by a lot of researchers in order to analyze newly revealed languages and train students only coming up the toddling level of linguistic studies. In this paper I will show how far the influence of Indian linguistics has colored the flow of linguistic growth historically. Especially through the analysis of Panini grammar I will prove the intimate relationship between the Indian linguistic theory and the generative grammar - it is the most active theory at present. The methods that Panini applied to constitute the rules like sutra include lots of information, that also could be discovered at the rules postulated in the generative grammar. One of the common features found at both linguistic theories is the simplicity of rule representation. At the generative grammar a rule has to be established without any redundancy. When certain number of sounds like p, b, m show the same phonological. change relevant to lips (labial in linguistic term) different rules need not to be given for each sound separately. It is better to find a way of putting the sounds together in a rule with grouping the 3 sounds with the shared phonetic feature 'labial'. In Panini grammar the form of a rule was decided based on the simplicity, too. For example, sutra 6.1.77 shows the phonological connection between the vowels i, u r 1 and the semi-vowels y, v, r, 1. However, it does not require to postulate 4 individual rules respectively. Instead a rule in which the vowels and the semi-vowels are involved is suggested, and linguistically the rule make it clear that the more simpler the rules will be the better they can reflect the efficiency of human language acquisition. Although the systems introduced at Panini grammar have some sense of distance from the language education itself we cannot deny the fact that the grammar formulates the a turning point of linguistic development. It is essential for us to think over the grammar from the view point of the modem linguistic theories to understand their root and trunk more thoroughly. It will also help us to predict in which way linguistic tendency will proceed to in future.

• 대한산업공학회지
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• 제27권1호
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• pp.30-36
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• 2001

We present a new algorithm for mining association rules in the large database. Association rules are the relationships of items in the same transaction. These rules provide useful information for marketing. Since Apriori algorithm was introduced in 1994, many researchers have worked to improve Apriori algorithm. However, the drawback of Apriori-based algorithm is that it scans the transaction database repeatedly. The algorithm which we propose scans the database twice. The first scanning of the database collects frequent length l-itemsets. And then, the algorithm scans the database one more time to construct the data structure Common-Item Tree which stores the information about frequent itemsets. To find all frequent itemsets, the algorithm scans Common-Item Tree instead of the database. As scanning Common-Item Tree takes less time than scanning the database, the algorithm proposed is more efficient than Apriori-based algorithm.

• 한국수학교육학회지시리즈A:수학교육
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• 제43권4호
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• pp.337-347
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• 2004

Korea and China have maintained close relationships since the ancient times along with Japan, which also shares the common Chinese culture. The three major players in Northeast Asia have been recognizing their increasing importance in politics, economy, society, and culture. Considering those relationships among the three countries, it's necessary to compare and investigate their mathematics terminology. The purpose of this study is to investigate the similarities and differences between the terminology of school mathematics in Korean, Chinese and Japanese. The mathematics terms included in the junior high school of Korea were selected, and the corresponding terms in Chinese and Japanese were identified. Among 133 Korean terms, 72 were shared by three countries, 9 Korean terms were common with China, and the remaining 52 Korean terms were the same as Japanese terms. Korea had more common terms with Japan than China, which can be explained by the influences of the Japanese education during its rule of Korea in the past. The survey with 14 terms which show the discrepancy among 3 countries were conducted for in-service teachers and pre-service teachers. According to the result of the survey, preferred mathematics terms are different from one group to the other, yet the Korean mathematics terms were more preferred in general. However some terms in Chinese and Japanese were favored in certain degree. This result may provide meaningful implications to revise the school mathematics terms in the future.

• 한국전자파학회논문지
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• 제24권3호
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• pp.278-285
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• 2013

본 논문에서는 상용 65 n CMOS 공정을 이용하여 100~110 GHz에서 동작하는 저잡음 증폭기와 커플러를 구현하였다. 제작된 LNA는 3단 공통 소스 FET로 구성되었다. 단위 공통 소스 셀의 높은 이득 특성을 얻기 위해 이를 고려한 레이아웃을 하였다. 또한, 저잡음 특성과 충분한 이득을 얻기 위해 성능을 최적화시켰다. 커플러는 CMOS 공정의 multimetal을 이용한 broadside 커플러로 구성하였다. Density rule을 만족시키기 위한 metal strip을 사용해 이에 의한 영향을 고려해 커플러 동작이 가능하도록 설계하였다. 제작된 저잡음 증폭기의 측정 결과, 100 GHz에서 5.64 dB, 110 GHz에서 6.39 dB의 이득과 10 % 이상의 3-dB 대역폭, 11.66 dB의 잡음 지수를 얻었다. 커플러는 100~110 GHz 대역에서 2~3 dB의 삽입 손실, 1 dB 이하의 magnitude mismatch와 $5^{\circ}$ 이하의 phase mismatch를 얻었다.

• 융합신호처리학회논문지
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• 제8권4호
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• pp.272-278
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• 2007

본 논문에서는 모델 기반 접근 방법을 이용하여 임베디드 소프트웨어를 개발하기 위한 자동화된 API 변환기에 대하여 기술한다. MDA(Model Driven Architecture)가 임베디드 소프트웨어의 개발에 관해서는 지원이 매우 미약하기 때문에, 우리는 MDA의 장점인 구현 공정의 자동화를 포함하면서도 실시간 오버헤드 문제를 해결할 수 있는 새로운 접근 방법을 제시한다. 첫 번째로, 어느 특정 RTOS에 의존하지 않지만 전형적인 RTOS 서비스들의 대부분을 제공할 수 있도록 Generic API를 정의한다. 우리는 이 Generic API를 이용하여 타겟 응용프로그램의 RTOS와 관련된 행동을 CIC(Common Intermediate Code)에서 표현할 수 있다. 그 다음에, Generic API를 이용하여 기술된 CIC를 특정 RTOS에서 수행할 수 있는 C-코드로 변환할 수 있는 변환 툴을 제안한다. 제안된 API 변환기는 외부에 정의되어 있는 XML 변환 규칙을 이용하여 코드를 변환한다. 따라서 API 변환기는 이 변환 규칙을 수정하거나 추가하여 다른 RTOS로 적용할 수 있도록 확장이 가능하다. 실험을 통하여 제안된 방법을 확인한다.

• 대한조선학회논문집
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• 제46권1호
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• pp.31-42
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• 2009

Common structural rule (CSR) doesn' t provide any other specific regulations for permanent means of access (PMA) platform structure in a cargo oil tank. The PMA platform is recommended to comply with scantling requirement of local support member. However, it leads to too conservative scantlings compared with actual loads imposed on the platform. This paper proposes a strength assessment procedure for the PMA structure based on a nonlinear ultimate strength. The ultimate strength is evaluated in a sufficiently conservative way. The first linear buckling mode is used as an initial imperfection shape and its magnitude is determined using the definitions of DNV PULS. Since the same imperfection mode as the failure mode of the ultimate limit state is assumed, it can accelerate the failure. Au ultimate strength capacity curve obtained from a series of nonlinear FE analysis is compared with actual stresses calculated by CSR cargo hold analysis.

• Structural Engineering and Mechanics
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• 제42권4호
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• pp.507-530
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• 2012

Age-related problems especially corrosion and fatigue are normally suffered by weatherworn ships and aging offshore structures. The effect of corrosion is one of the important factors in the Common Structural Rule (CSR) guideline of the ship design based on a 20 or 25 years design life. The aim of this research is the clarification of the corrosion effect on ultimate strength of stiffened panels on various types of double hull oil tankers. In the case of ships, corrosion is a phenomenon caused by the ambient environment and it has different characteristics depending on the parts involved. Extensive research considering these characteristic have already done by previous researchers. Based on this data, the ultimate strength behavior of stiffened panels for four double hull oil tankers such as VLCC, Suezmax, Aframax, and Panamax classes are compared and analyzed. By considering hogging and sagging bending moments, the stiffened panels of the deck, inner bottom and outer bottom located far away from neutral axis of ship are assessed. The results of this paper will be useful in evaluating the ultimate strength of an oil tanker subjected to corrosion. These results will be an informative example to check the effect of ultimate strength of a stiffened panel according to corrosion addition from CSR for a given type of ship.

• 한국과학교육학회지
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• 제13권3호
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• pp.389-395
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• 1993

Science textbooks which were compiled by CHOSUN Government General are known as books which appeared after 'Science Textbook for Common School' (1923-) compiled by CHOSUN Government General which are almost similar to state authorized textbooks and are also known as leaving the effect on 'Science Textbook for Elementary School' (1931-) which were focused on the subjects being issued since then and 'Science Text for Elementary Course' (1942-) being compiled by the Education Ministry, However in this research it was found out that there were publications in 1911, 1913 and 1921 and they were harbingers for 'Science Textbook for Elementary School' 0931-). For this reason it was decided to report overall picture on the science textbooks being compiled by CHOSUN Government General. And it was possible to illustrate that such textbooks can be classified into following 5 periods ; The 1st period:The time for search--'Science Textbook for Students of Common school' 1911 compiled by CHOSUN Government General. The 2nd period:Commencing separate compilation--'Science Textbook for Common School' 1913 compiled by CHOSUN Government General. (The 2'nd period:Final Separate Compilation-- Reissue after corrections of 'Science Textbook for Common School' compiled by CHOSUN Government General, 1921.) The 3rd period:Same as the state authorized science textbook of Japan--' Science Textbook for Common School' compiled by CHOSUN Government General, totally 3 books 1923-. The 4th period:Separate compilation, centered on subjects--'Science Textbook for Elementary School' compiled by CHOSUN Government General, 1931-. (The 4'th period:Changers of subjects--'Science Text for Elementary School' compiled by CHOSUN Government General, 1937-. The 5th period:Matched to compiled by the Education Ministry--'Observation of Nature' compiled by CHOSUN Government General, 1942-'Science Text for Elementary School'(Writing laterally) 1943-.

• 한국정보통신학회:학술대회논문집
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• 한국해양정보통신학회 2008년도 춘계종합학술대회 A
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• pp.213-217
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• 2008

본 논문에서는 표준 IMC-PID 제어기에 시스템 식별상의 위상 조절 인자를 설계 변수로 추가함으로 새로운 IMC-PID 제어기 설계 방법을 제안한다. 제안된 제어기의 동조법으로 해석적으로 구해진 주파수 영역 특성을 통해 주파수 영역 성능을 보장하도록 하는 설계 변수의 구속 조건 하에서 시간영역의 적분 오차 지표를 가격함수로 최소화하는 최적 해를 얻는다. 이 제안된 동조법은 다양한 설계 사양을 동시에 고려하도록 하여 기존의 IMC-PID의 단일 설계 변수 동조가 갖는 비유연성 문제를 개선하였다. 사례 연구에서 기존의 동조법들과의 성능 비교를 통해 그 유용성을 검토했다.