• Journal of Space Technology and Applications
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• v.1 no.2
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• pp.178-198
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• 2021

The Solar Space Environment Division of the Korean Society of Space Science (KSSS) has recently conducted a survey among the domestic researchers affiliated with academia, national research institutes, and for-profit institutes of how the data and models in their professional research field are produced, maintained, and utilized. The primary purpose of this survey is to increase the awareness and utilization of the space environment data and models as well as to promote constructive collaborations among the domestic and international researchers. The models and data surveyed are categorized into three sub-fields: the solar and interplanetary space, the (terrestrial) magnetosphere, and the ionosphere and upper atmosphere. The present paper reports the survey results in the "Magnetosphere" category. The survey shows that the domestically produced data in this category are far less than the data produced in other categories. This can be understood in part as follows: Magnetospheric research relies heavily on the in-situ observations but the development and operation of space-hardened satellites require a significant investment. Nevertheless, the recent publications show an increasing trend of research using the data from the ground stations and the recently launched domestic space missions. In the modeling front, there are first-principles physics models covering from the magnetospheric scale to the sub-ion scale and the models geared towards the space weather prediction. The detailed survey results can be accessed from the KSSS website (http://ksss.or.kr/).

• Journal of the Korea Institute of Information and Communication Engineering
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• v.17 no.5
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• pp.1253-1258
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• 2013

This Paper deals with detection and defense methods for underwater weapons because there are so many dangers of underwater weapons not only in the war period but also in the peace time. Underwater mines are the representative strategic arms. The sensors and target detection methods, threat elimination method of mines included in this paper. Among the various sensors of mine, we use the magnetometor for target detection method in the simulation and execute the analysis of magnetic field of detected target ships. It will be also provided that effectiveness of target detection, sweeping method of mine, tactics of mine planning and mine sweeping and so on.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.24 no.11
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• pp.1534-1538
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• 2020

Smart farming education service focuses on the dissemination of farming information that is the farming knowledge, farming skill, and farmer's experiences and knowhow, etc. This farming information is supposed from current activities, farming product and from the experience of farmer on the field. If the information is not available, or if available and not in a form that is amenable to being brought to the end producer then the process stalls at this point. The core component of the automation process for smart farming education service is the creation of a data store which will be a repository for the information of the smart farming education. The farming sector will benefit immensely from the implementation of farming data in farming contents repository which will serve as the knowledge base for the smart farming education service.

• 한국정보교육학회:학술대회논문집
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• 2007.08a
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• pp.221-226
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• 2007

군 복무 중 이러닝을 통해 군 장병의 자기 계발을 돕기 위해 정부는 군 이러닝 포털시스템을 구축하였다. 본 연구에서는 군 이러닝 포털 시스템을 통해 다양한 교육용 콘텐츠를 제공하기 위해 교육용 콘텐츠에 대한 메타데이터를 설계하였다. 군 장병들이 원하는 콘텐츠와 이를 표현하는 방법에 대한 설문 조사를 통해 요구 분석하였으며, 이를 토대로 분류 체계와 분류 항목을 선정하였다. 이러한 분류 체계와 분류 항목을 KEM과 SCORM과 같은 국내 외 콘텐츠 표준화 규격을 참조하여 교육 콘텐츠 메타데이터로 설계하였다.

• Proceedings of the KIPE Conference
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• 2017.11a
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• pp.71-72
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• 2017

본 논문에서는 비선형 최적화 기법을 이용하여 자기 포화(magnetic saturation) 및 교차 결합 현상(cross-coupling effect)을 고려한 매입형 영구자석 전동기(IPMSM)의 실시간 MTPA 제어 방법을 제안한다. 이는 토크 지령 추종과 최소 동손 운전을 만족하는 제한 최적화(constraint optimization) 문제로 접근할 수 있다. 이를 통해 유도한 연립 비선형 방정식의 경우, Levenberg-Marquardt 수치 해석법을 적용하여 안정적이면서 빠르게 해를 구할 수 있다. 이러한 방법을 이용하면 참조표(look-up table) 없이 운전 환경의 실시간 변동을 고려한 효율적인 MTPA 운전이 가능하다. 시뮬레이션을 통해 제안된 알고리즘의 전류 해가 최적 운전점과 일치함을 확인하였다.

• Journal of The Korean Association of Information Education
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• v.9 no.4
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• pp.595-606
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• 2005

7차교육과정에서의 초등 컴퓨터교육은 재량활동시간 또는 특별활동시간에 단순한 응용프로그램(워드프로세서, 엑셀, 파워포인트 등)을 활용하거나 인터넷을 이용한 정보검색 수준이다. 따라서, 문제해결 능력이나 논리적 사고력을 향상시키는데는 미흡하다. 인지능력이 뛰어난 초등학교 5, 6학년에는 이러한 컴퓨터 활용방법 교육보다 컴퓨터 기초원리 또는 프로그래밍교육이 필요하다. 본 논문은 프로그래밍교육을 재량 특별활동 시간에 학년별(5, 6학년) 또는 통합학년으로 학습할 수 있게 프로그래밍교육과정 60차시 분을 개발하여 제안하였다. 개발한 교육과정은 교수 및 학습자의 요구사항을 최대한 반영하기 위해 설문조사 등을 통해 얻은 기초자료를 참조하였다. 제안한 교육과정이 초등학교 5, 6학년에 적합하고 우수한지를 검토하기 위해 일부 차시의 교육과정으로 5, 6학년을 대상으로 재량활동시간에 직접 교수 학습한 후 자기평가, 설문조사를 실시하였다. 결과로 제안한 교육과정이 적합성과 우수성이 있다고 판단되었다.

• Geophysics and Geophysical Exploration
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• v.13 no.3
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• pp.249-255
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• 2010

Since the 1990's, a number of ULF geomagnetic disturbance associated with earthquake occurrences have actively been reported, and polarization analysis of geomagnetic fields becomes one of potential candidates to be capable of predicting short-term earthquake. This study develops the modified polarization analysis method based on the previous studies, and analyzes three-component geomagnetic fields obtained at Cheongyang geomagnetic observatory using the developed method. A daily polarization value (the ratio of spectral power of horizontal and vertical geomagnetic field) is calculated with a focus on the 0.01 Hz band, which is known to be the most sensitive to seismogenic ULF radiation. We analyze a total of 10 months of geomagnetic data obtained at Cheongyang observatory, and compare the polarization values with the Kp index and the earthquake occurred in the analysis period. The results show that there is little correlation between the temporal variations of polarization values and Kp index, but remarkable increases in polarization values are identified which are associated with two earthquakes. Comparison the polarization values obtained at Cheongyang and Kanoya observatory indicates that the increases of polarization values at Cheongyang might be due to not global geomagnetic induction but the locally occurred earthquakes. Furthermore, these features are clearly shown in normalized polarization values, which take account in the statistical characteristics of each geomagnetic field. On the basis of these results, polarization analysis can be used as promising tool for monitoring the earthquake-precursory phenomenon.

• The Journal of Society for e-Business Studies
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• v.17 no.3
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• pp.85-103
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• 2012

This study focused on user evaluation for personalized recommender systems with the integrated view of performance of the system and user attitude of recommender systems. Since users' evaluations of recommender systems can be affected by recommendation outcomes and presentation methods, both system performances based on outcomes and user attitudes formed by the presentation methods should be considered when explaining users' evaluations. However, an integrated view of system performance and user attitudes has not been applied to explain users' evaluation of recommender systems. Thus, the goal of this study is to explain users' evaluations of recommender systems under the integrated view of predictive features and explanation features at the same time. Our findings suggest that social presence, both accuracy and noveltyhave impacts onuser satisfaction for recommender systems. Especially, predictive features including accuracy and novelty affected user satisfaction. Novelty as well as accuracy is one of the significant factors for user satisfaction while recommender systems provided usual items users have experienced when systems provide serendipitous items. Likewise, explanation features with social presence and self-reference were important for user evaluation of personalized recommender systems. For explanation features, while social presence appears as one of important factors to user satisfaction of evaluating personalized recommendations, self-reference has no significant effect on user's satisfaction for recommender systems when compared to the result of social presence. Self-referencing messages did not affect user satisfaction but the levels of self-referencing are different between low and high groups in the experiment.

• Journal of the Institute of Electronics and Information Engineers
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• v.49 no.12
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• pp.156-163
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• 2012

Recently, Information Hiding Technology are becoming increasingly demanding in the field of international security, military and medical image This paper proposes data hiding technique utilizing parity checker for gray level image. many researches have been adopted LSB substitution and XOR operation in the field of steganography for the low complexity, high embedding capacity and high image quality. But, LSB substitution methods are not secure through it's naive mechanism even though it achieves high embedding capacity. Proposed method replaces LSB of each pixel with XOR(between the parity check bit of other 7 MSBs and 1 Secret bit) within one pixel. As a result, stego-image(that is, steganogram) doesn't result in high image degradation. Eavesdropper couldn't easily detect the message embedding. This approach is applying the concept of symmetric-key encryption protocol onto steganography. Furthermore, 1bit of symmetric-key is generated by the self-reference of each pixel. Proposed method provide more 25% embedding rate against existing XOR operation-based methods and show the effect of the reversal rate of LSB about 2% improvement.

• Journal of Korea Port Economic Association
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• v.26 no.1
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• pp.43-60
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• 2010

The purpose of this paper is to show the clustering measurement way for Korean container terminals by using neural network based SOM(Self Organizing Map). Inputs[Number of Employee, Quay Length, Container Terminal Area, Number of Gantry Crane], and output[TEU] are used for 3 years(2002,2003, and 2004) for 8 Korean container terminals by applying both DEA and SOM models. Empirical main results are as follows: First, the result of DEA analysis shows the possibility for clustering among the terminals and reference terminals except Gamcheon and Gwangyang terminals because of the locational closeness. Second, the result of neural network based SOM clustering analysis shows the positive clustering in clustering positions 1, 2, 3, 4, and 5. Third, the results between SOM clustering and DEA clustering show the matching ratio about 67%. The main policy implication based on the findings of this study is that the port policy planner of Ministry of Land, Transport and Maritime Affairs in Korea should introduce the clustering measurement way for the Korean container terminals using neural network based SOM with DEA models for clustering Korean ports and terminals.