• The Bulletin of The Korean Astronomical Society
• /
• v.39 no.1
• /
• pp.89.1-89.1
• /
• 2014

빛공해란, 불필요하거나 필요 이상의 인공빛이 야생 동식물들과 우리 인간들에게 악영향을 미치는 현상을 말하며, 실생활에서 인공빛 에너지를 목적에 맞지 않게 사용하는 것이 이 현상의 주요 원인이라고 할 수 있다. 빛공해 현상은 야생 동식물들에게 악영향을 주어 개체수를 감소시킬뿐만 아니라 멸종에까지 이르게 할 수 있으며, 지구 자전의 영향으로 하루 24시간 주기로 설정되어 있는 우리 인간의 생체리듬을 교란시켜 암, 비만, 당뇨병, 그리고 우울증 등과 같은 인간의 목숨을 위협할 수 있는 질병들을 일으키기도 한다. 하지만 인공빛을 목적에 맞게 올바르게 사용한다면 그로 인해 절약된 에너지와 그 비용을 다른 필요한 분야에 대체하여 사용할 수 있을 것이다. 우리는 과거의 빛공해 관련 논문과 보고서의 설문조사 결과를 통하여 빛공해로 인한 피해와 에너지 낭비 문제가 빛공해에 대한 일반 시민들의 무관심으로부터 발생하고 있다는 사실을 확인할 수 있었다. 따라서 우리는 빛공해에 대한 일반 시민들의 인식 변화를 알아보기 위하여 기존에 진행된 설문조사와 같은 문답내용의 설문조사를 올해 다시 실시하였다. 그 설문조사의 결과를 통하여 우리는 과거보다 빛공해에 대한 인식이 많이 확산되어 있다는 사실을 알 수 있었으며, 그 이유로는 최근 빛공해와 관련된 많은 뉴스 기사들과 함께 웹상의 소셜네트워크와 같은 다양한 경로의 정보매체들을 통하여 빛공해에 대한 정보를 보다 빠르고 쉽게 접할 수 있는 환경이 조성되었기 때문이라고 분석하였다. 빛공해 인식 확산에 더욱 더 기여하기 위하여 최근에 우리는 국제 어두운 밤하늘 협회 한국 지부 (Korean Chapter, International Dark-Sky Association) 인가를 받아 그 단체 이름으로 빛공해 방지 홍보 사업을 온라인과 오프라인을 통하여 보다 더 활발히 진행하기 위하여 많은 노력을 하고 있다.

• Journal of the Korean School Mathematics Society
• /
• v.22 no.4
• /
• pp.351-367
• /
• 2019

Slope is an important mathematical concept that is connected to advanced mathematics as well as a basic concept as an indicator of the steepness of a straight line. The purpose of this study is to see how the concept of slope is presented in mathematics textbooks of middle school. For this study, we analyzed the types of slope concepts in the textbooks. In particular, we analyzed motivation activity, definition, examples of slope in them and used a concept framework of slope by Stump(1999, 2001), Moore-Russo, Connor & Rugg (2011). As a result, it was shown that middle school mathematics textbooks use the types of slope concepts to be biased when explaining the slope or presenting the slope problems. In addition, the real contexts of slope is poorly presented, and the concept types change from visual aspect to analytical aspect in the processes. This study provides suggestions on how to present the slope concepts in mathematics curriculum and middle school textbooks.

• Communications of Mathematical Education
• /
• v.24 no.3
• /
• pp.659-689
• /
• 2010

Taxicab distance function is a practical distance notion which gives us information of real world pathway distance that really taxi can go through. As one of the non-Euclidean geometry, this study of an ideal city with all roads running horizontal or vertical, was introduced by the Russian Mathematician H. Minkowski and synthetically reported by the E. F. Kraus in 1986. After that, there were many reports and papers on this topic and still being researched. At this point of view, our research about taxicab geometry provides its differences from Euclidean plane geometry, and considers about several theorems on plane geometry using the taxicab distance function.

• Journal for History of Mathematics
• /
• v.25 no.4
• /
• pp.1-10
• /
• 2012

In Chinese mathematics, there have been two numeral systems, namely one in spoken language for recording and the other by counting rods for computations. They concerned with problems dealing with practical applications, numbers in them are concrete numbers except in the process of basic operations. Thus they could hardly develop a pure theory of numbers. In Song dynasty, 0 and TianYuanShu were introduced, where the coefficients were denoted by counting rods. We show that in this process, counting rods took over the role of the numeral system in spoken language and hence counting rod numeral system plays the role of that for abstract numbers together with the tool for calculations. Decimal fractions were also understood as denominate numbers but using the notions by counting rods, decimals were also admitted as abstract numbers. Noting that abacus replaced counting rods and TianYuanShu were lost in Ming dynasty, abstract numbers disappeared in Chinese mathematics. Investigating JianJie YiMing SuanFa(簡捷易明算法) written by Shen ShiGui(沈士桂) around 1704, we conclude that Shen noticed repeating decimals and their operations, and also used various rounding methods.

• Journal of Korea Multimedia Society
• /
• v.10 no.5
• /
• pp.642-651
• /
• 2007

Recently, digital convergence, whose core demand is OSMU (One Sourse Multi Use),has been the main topic in e-learning domain and industry. However, the existing web learning content and the new resource developed toprovide contents to different learning environment must be processed to adapt the new learning settings, which causes the cost and time problem, So in this paper we design and implement a Java based SCORM content transcoding system which can transcode the SCORM-based learning content into MHP-based DiTV content in order to adapt t-learning environment using DiTV, which is closer to our real life. Using this system which has ability of inter-operation, reuse, highly-use, the problem mentioned above can be solved well. Moreover, it is possible for a learner who is not familiar with computer to study using DiTV instead of PC.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
• /
• 2019.05a
• /
• pp.190-192
• /
• 2019

Not only learners majoring in computer science, but also non-engineered learners want to implement their ideas as apps through real-life problems. In response, first-year university students with little experience in creating apps studied how to develop mobile platform apps to improve computing thinking skills. We applied the teaching and learning procedures of the Discovery-Design-Development among the software teaching and learning models, and used Android Studio Unified Development Environment (IDE) as a development tool to design mobile platform app development projects and assess whether they helped improve computing thinking skills. The application of the designed teaching and learning method found that the project output was implemented as an app through emulator, which gave students high interest in class and satisfaction, and was effective in improving their computing thinking ability.

• Journal of the Korea Institute of Information Security & Cryptology
• /
• v.19 no.5
• /
• pp.3-15
• /
• 2009

The short group signature introduced by Boneh et al. is one of famous anonymous signature schemes. However, for applying it to the real applications, several restrictions should be considered. The perfect anonymity of users, which is given by group signatures, prevents service providers to provide certain services or resources. For this reason, the local linkability which reduces the anonymity of users has to be provided to the service providers. In addition, the group signature keys, which are one-sidedly assigned from a group manager, cannot support the strong exculpability of users. Hence, the short group signature has to be modified for supporting the strong exculpability. In this paper, we perform a study on the use of the short group signature by proposing a few methods for supporting those two properties.

• Journal of the Korea Institute of Information Security & Cryptology
• /
• v.11 no.6
• /
• pp.41-51
• /
• 2001

Group signature schemes allow a group member to sign messages anonymously on behalf of the group. In case of dispute, only a designated group manager can reveal the identity of the member. During last decade, group signature schemes have been intensively investigated in the literature and applied to various applications. However, there has been no scheme properly handling the situation that a group member wants to leave a group or is excluded by a group manager. As noted in[3], the complexity of member deletion stands in the way of real world applications of group signatures and the member deletion problem has been a pressing open problem. In this paper we propose an efficient group signature scheme that allows member deletion. The length of the group public key and the size of signatures all independent of the size of the group and the security of the scheme relies on the RSA assumption. In addition, the method of tracing all signatures of a specific member is introduced.

• The Korean Journal of Applied Statistics
• /
• v.34 no.3
• /
• pp.389-399
• /
• 2021

In recent years, word embedding has been a popular field of natural language processing research and a skip-gram has become one successful word embedding method. It assigns a word embedding vector to each word using contexts, which provides an effective way to analyze text data. However, due to the limitation of vector space model, primary word embedding methods assume that every word only have a single meaning. As one faces multi-sense words, that is, words with more than one meaning, in reality, Neelakantan (2014) proposed a multi-sense skip-gram (MSSG) to find embedding vectors corresponding to the each senses of a multi-sense word using a clustering method. In this paper, we propose a modified method of the MSSG to improve statistical accuracy. Moreover, we propose a data-adaptive choice of the number of clusters, that is, the number of meanings for a multi-sense word. Some numerical evidence is given by conducting real data-based simulations.

• Journal of the Korea Society of Computer and Information
• /
• v.27 no.4
• /
• pp.111-118
• /
• 2022

In recent years, the number of single-person elderly households has increased, but when an emergency situation occurs inside the house in the case of single-person households, it is difficult to inform the outside world. Various smart home solutions have been proposed to detect emergency situations in single-person households, but it is difficult to use video media such as home CCTV, which has problems in the privacy area. Furthermore, if only a single sensor is used to analyze the abnormal situation of the elderly in the house, accurate situational analysis is limited due to the constraint of data amount. In this paper, therefore, we propose an algorithm of abnormal situation detection fusion inside the house by fusing 2DLiDAR, dust, and voice sensors, which are closely related to everyday life while protecting privacy, based on their correlations. Moreover, this paper proves the algorithm's reliability through data collected in a real-world environment. Adnormal situations that are detectable and undetectable by the proposed algorithm are presented. This study focuses on the detection of adnormal situations in the house and will be helpful in the lives of single-household users.