• Title/Summary/Keyword: 대학정보시스템

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Effective Evaluation of Quality of Protection(QoP) in Wireless Network Environments (무선 네트워크 환경에서의 효과적인 Quality of Protection(QoP) 평가)

  • Kim, Hyeon-Seung;Lim, Sun-Hee;Yun, Seung-Hwan;Yi, Ok-Yeon;Lim, Jong-In
    • Journal of the Korea Institute of Information Security & Cryptology
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    • v.18 no.6A
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    • pp.97-106
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    • 2008
  • Quality of Protection(QoP) provides a standard that can evaluate networks offering protection. Also, QoP estimates stability of the system by quantifying intensity of the security. Security should be established based on the circumstance which applied to appropriate level, and this should chose a security policy which fit to propose of network because it is not always proportioned that between stability of security mechanism which is used at network and performance which has to be supported by system. With evolving wireless networks, a variety of security services are defined for providing secure wireless network services. In this paper, we propose a new QoP model which makes up for weak points of existing QoP model to choose an appropriate security policy for wireless network. Proposed new QoP model use objectively organized HVM by Flow-based Abnormal Traffic Detection Algorithm for constructing Utility function and relative weight for constructing Total reward function.

XQuery Query Rewriting for Query Optimization in Distributed Environments (분산 환경에 질의 최적화를 위한 XQuery 질의 재작성)

  • Park, Jong-Hyun;Kang, Ji-Hoon
    • Journal of the Korea Society of Computer and Information
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    • v.14 no.3
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    • pp.1-11
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    • 2009
  • XQuery query proposed by W3C is one of the standard query languages for XML data and is widely accepted by many applications. Therefore the studies for efficient Processing of XQuery query have become a topic of critical importance recently and the optimization of XQuery query is one of new issues in these studies. However, previous researches just focus on the optimization techniques for a specific XML data management system and these optimization techniques can not be used under the any XML data management systems. Also, some previous researches use predefined XML data structure information such as XML schema or DTD for the optimization. In the real situation, however applications do not all refer to the structure information for XML data. Therefore, this paper analyzes only a XQuery query and optimize by using itself of the XQuery query. In this paper, we propose 3 kinds of optimization method that considers the characteristic of XQuery query. First method removes the redundant expressions described in XQuery query second method replaces the processing order of operation and clause in XQuery query and third method rewrites the XQuery query based on FOR clause. In case of third method, we consider FOR clause because generally FOR clause generates a loop in XQuery query and the loop often rises to execution frequency of redundant operation. Through a performance evaluation, we show that the processing time for rewritten queries is less than for original queries. also each method in our XQuery query optimizer can be used separately because the each method is independent.

Reexamination of foreign collector's sites and exploration routes in Korea (IV) - with respect to T. Ishidoya (외국인의 한반도 식물 채집행적과 지명 재고(IV): Tstomu Ishidoya 석호곡면(石戶谷勉))

  • Chang, Chin-Sung;Chang, Kae-Sun
    • Korean Journal of Plant Taxonomy
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    • v.40 no.2
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    • pp.90-104
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    • 2010
  • Tstomu Ishidoya (1891-1958), a Japanese taxonomist and pharmacognosist, conducted his plant explorations on the Korean peninsula from 1911 to 1943. Especially from 1912 to 1923 Ishidoya, as a governmentemployee of Chosen Governor-General collected numerous specimens of woody plants which were later studied by T. Nakai. Collection numbers totalling 6,487 (= collections) were recorded according to Nakai's studies, while only 1,350 speciemens are confirmed to be preserved now in three Japanese herbaria (Tokyo Universtiy, Kyoto University and National Museum of Nature and Science). All collection sites were described by Nakai using romanized characters with Japanese pronunciation. For this study, one hundred seventy three locality names were reviewed using those of Ishidoya's specimens that are deposited at TI, KYO, and TNS; the database, Korean Biodiversity Information System (http://www.nature.go.kr), and the articles and literature of Nakai and Ishidoya. These are listed in the order of his collection dates.

Development of Integrated Flood Analysis Program for Standardization of Disaster Map (재해지도 작성 표준화를 위한 내·외수 통합 침수해석 프로그램(i-FIM)의 개발)

  • Lee, Jae Yeong;Keum, Ho Jun;Kim, Beom Jin;Cha, Young Ryong;Han, Kun Yeun
    • Proceedings of the Korea Water Resources Association Conference
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    • 2018.05a
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    • pp.278-278
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    • 2018
  • 현재 우리나라에서는 행정안전부의 풍수해저감종합계획, 사전재해영향성검토협의, 재해위험지구개선사업 등에 해외에서 개발된 상용프로그램이 사용돼 접근성 저하로 인해 지자체 방재담당자의 실무나 대학에서 연구용으로 다루기에는 한계가 있다. 이에 본 연구에서는 내수침수, 외수침수, 2차원 침수해석으로 구성하여 GUI 기능을 강화한 통합침수재해지도 작성시스템(i-FIM, Integrated Flood Inundation Modeling system)을 개발하여 입력자료의 구성 및 매개변수의 수정이 용이하게 함으로써 하수관망 등에 부분적인 설계 변경이 있는 경우 지자체 방재담당자가 간단한 작업을 통해 침수영향 변화를 쉽게 파악할 수 있도록 하였다. 또한, 상세한 지형의 반영이 필요한 도시지역의 2차원 침수해석의 경우 계산격자 망의 크기가 작아질수록 소요되는 계산시간이 기하급수적으로 증가하는 한계가 있어 i-FIM에서는 계산격자를 $2{\times}2$, $3{\times}3$, $5{\times}5$ Subgrid 형태의 격자를 적용하고, 병렬프로그래밍과 계산시간조정 기능을 추가하여 2차원 침수해석 모형의 계산 속도를 향상시켰다. 이를 실무에 적용하기 앞서 2006년 집중호우로 인해 안성시에서 발생한 제방 붕괴사상, 2016년 태풍 차바로 인해 울산시에서 발생한 제방 월류 사상을 통해 침수흔적도와 비교하여 검증을 실시하였다. i-FIM에서 최종적인 2차원 침수해석 결과는 2017년에 개정된 '재해지도 작성 기준 등에 관한 지침'의 침수심 등급 구분의 색채 설정에 따라 각 격자별 침수심을 표출함으로써 표준화된 재해지도 작성이 가능하도록 하였다. 또한, 포털사이트의 지도 및 위성지도에 표출함으로써 침수 위험이 발생할 수 있는 지역의 현재 이용 용도를 파악하여 침수재해에 대한 상세한 대책을 마련할 수 있을 것으로 판단된다.

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Removal of Radioactive Caesium ion using Ferromagnetic in water : A reivew (강자성체를 통한 수중의 방사능 세슘이온 제거 동향)

  • Yeo, Wooseok;Kim, Jong Kyu
    • Proceedings of the Korea Water Resources Association Conference
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    • 2018.05a
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    • pp.266-270
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    • 2018
  • 원자력 방사능 폐기물 또는 원자력 발전소 해체시 발생 가능한 세슘 이온은 인체뿐만 아니라 생태계 환경에도 큰 악영향을 미친다고 알려져 있다. 이러한 세슘 이온은 자연 속으로 손쉽게 스며들어 발생한 지역뿐만 아니라 쉽게 퍼지게 되어 넓은 지역까지 피해를 주게 되며, 반감기가 30년으로써 한번 자연계에 누출되면 장시간 잔존하여 인간 및 생태계에 악영향을 미치게 된다. 세슘이온이 몸속에 들어오게 되면 장에서 몸으로 100% 흡수되며 내장에 축척되어 연조직 전체에 분포하게 되며 갑상선 암과 같은 심각한 위험에 초래하게 된다. 2011년 발생한 후쿠시마 원전 사고 이후 국내에서도 많은 관심을 가지기 시작하였으며, 따라서 수중의 세슘이온을 제거하기 위하여 나노 입자 형태의 기능성을 가진 물질들을 적용한 많은 연구가 이루어지고 있다. 이러한 나노물질들은 수중의 세슘이온 제거에 대하여 우수한 제거효율을 보여주고 있으나 나노 입자 특성상 사용 이후 회수가 어려워 기능성 물질들의 확산 및 축적에 따른 2차 환경오염의 문제점까지 발생하게 된다. 최근 수처리 분야에서 외부 자기장을 주게 되면 자성을 띄게 되는 물질인 자성체에 대한 관심이 급등하고 있다. 이러한 자성체들은 수중에서 별도의 회수 시스템 없이 자성으로 인하여 완벽히 자기분리 된다. 세슘제거에 탁월한 기능성 물질과 완벽한 자기분리가 가능한 자성체를 결합하여 특별한 회수장치 없이 외부 자기장만 주어진다면 수중의 세슘을 효과적으로 제거 또는 처리할 수 있다. 자성체 입자 표면에 흡착제인 프러시안 블루나 제올라이트와 같은 흡착제를 합성하여 수중의 세슘을 제거하는 연구가 활발히 이루어지고 있다. 그러나 기존의 자성체보다 좀 더 높은 자성을 가지고 있으며 외부 자기장에 의해 강하게 반응을 한다고 알려져 있는 강자성체(Ferromagnetic)를 사용하게 된다면 흡착제와 결합 이후 더욱더 강한 자성을 가진 흡착제가 탄생하며 이를 사용하면 높은 처리율뿐만 아니라 높은 슬러지 회수율을 가질 수 있다. 따라서 본 연구는 흡착제나 이온교환수지와 같은 기능성 물질을 사용하여 수중의 세슘을 제거하는 메커니즘과 강자성체가 가지고 있는 강한 자성의 성질을 결합한 복합체 제조에 대한 연구조사를 중점적으로 실시하였다. 본 연구에 의해 연구 조사된 결과를 바탕으로 수중의 세슘 이온에 대하여 높은 제거효율과 회수율을 가지는 새로운 형태의 복합체 제조에 관한 정보를 제공하고자 한다.

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Implementation of IoT Application using Geofencing Technology for Mountain Management (산악 관리를 위한 지오펜싱 기술을 이용한 IoT 응용 구현)

  • Hyeok-jun Kweon;Eun-Gyu An;Hoon Kim
    • Journal of Advanced Navigation Technology
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    • v.27 no.3
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    • pp.300-305
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    • 2023
  • In this paper, we confirmed that an efficient sensor network can be established at a low cost by applying Geofencing technology to a LoRa-based sensor network and verified its effectiveness in disaster management such as forest fires. We detected changes through GPS, gyro sensors, and combustion detection sensors, and defined the validity size of the Geofencing cell accurately. We proposed a LoRa Payload Frame Structure that has a flexible size according to the size of the sensor information.

Development of a regressive prediction method of solute transport in rivers based on relation between breakthrough curve and travel distance (하천에서 농도곡선-유하거리 상관성 기반 회귀적 물질혼합 예측 기법)

  • Kim, Byunguk;Seo, Il Won
    • Proceedings of the Korea Water Resources Association Conference
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    • 2022.05a
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    • pp.45-45
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    • 2022
  • 산업화에 따른 화학물질 사용량의 증가는 담수로의 유해화학물질 유출사고의 위험을 증가시키며, 이러한 사고는 하천수 수질과 수환경 생태계에 심각한 위해와 손상을 야기한다. 이러한 수질사고 발생시 신속 대응을 위해, 하천에 유입된 물질의 거동을 신속하게 예측하는 것이 필요하며 이 경우 1차원 추적모형이 주로 사용된다. 1차원 물질혼합 모형은 하천을 하나의 유선으로 보며, 복잡한 하천흐름의 시스템을 현상학적으로 해석하고, 오염물질의 이송 및 혼합 메카니즘을 모델 매개변수에 반영하여 모형화한다. 이러한 매개변수들은 직접적으로 측정하기 어려우며, 이론에 기반한 매개변수 산정 기법이 구축되지 않은 실정이다. 따라서 대부분의 연구에서는 추적자 실험을 실시하여 유한한 하천구간에서 추적자의 시간-농도곡선(Breakthrough curve, BTC)을 취득하고, 이를 통하여 대상 구간의 매개변수를 역산하는 최적화 기법에 의존하고 있다. 하지만, 모든 하천구간에 대하여 추적자 실험을 수행하여 데이터를 확보하는 것이 어렵기 때문에 최적화 기법의 적용성에 한계가 있다. 본 연구는 흐름정보가 제공되지 않은 미계측 하천구간에서 BTC를 신속하게 예측할 수 있는 회귀모형을 구축하는 것을 목표로 한다. 국내 하천에서 수행한 4회의 추적자 실험으로부터 취득한 28개 구간 케이스의 데이터에 대하여 농도곡선 전처리를 수행하고 14개의 통계적 특징을 추출하였으며, 계측된 흐름특성과의 상관관계를 분석하였다. 분석 결과, 대상 구간에서의 BTC의 변화가 추적자의 유하거리에 매우 높은 상관관계를 보였으며, 이를 이용하여 회귀모형을 제시하였다. 제안된 회귀모형을 적용하여 하류의 지점에서의 BTC를 예측하였으며, 1차원 이송-분산 방정식과 하천저장대모형을 활용한 예측결과와 비교하여 검증하였다. 그 결과, BTC의 변화특성을 활용한 회귀적 예측이 하천 지형 및 흐름의 변동성이 작은 구간에서 1차원 혼합모형들을 이용한 예측보다 더 높은 정확도를 보였으며, 이러한 장점은 장거리 예측에서 더 분명하게 나타났다.

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Recommender system using BERT sentiment analysis (BERT 기반 감성분석을 이용한 추천시스템)

  • Park, Ho-yeon;Kim, Kyoung-jae
    • Journal of Intelligence and Information Systems
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    • v.27 no.2
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    • pp.1-15
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    • 2021
  • If it is difficult for us to make decisions, we ask for advice from friends or people around us. When we decide to buy products online, we read anonymous reviews and buy them. With the advent of the Data-driven era, IT technology's development is spilling out many data from individuals to objects. Companies or individuals have accumulated, processed, and analyzed such a large amount of data that they can now make decisions or execute directly using data that used to depend on experts. Nowadays, the recommender system plays a vital role in determining the user's preferences to purchase goods and uses a recommender system to induce clicks on web services (Facebook, Amazon, Netflix, Youtube). For example, Youtube's recommender system, which is used by 1 billion people worldwide every month, includes videos that users like, "like" and videos they watched. Recommended system research is deeply linked to practical business. Therefore, many researchers are interested in building better solutions. Recommender systems use the information obtained from their users to generate recommendations because the development of the provided recommender systems requires information on items that are likely to be preferred by the user. We began to trust patterns and rules derived from data rather than empirical intuition through the recommender systems. The capacity and development of data have led machine learning to develop deep learning. However, such recommender systems are not all solutions. Proceeding with the recommender systems, there should be no scarcity in all data and a sufficient amount. Also, it requires detailed information about the individual. The recommender systems work correctly when these conditions operate. The recommender systems become a complex problem for both consumers and sellers when the interaction log is insufficient. Because the seller's perspective needs to make recommendations at a personal level to the consumer and receive appropriate recommendations with reliable data from the consumer's perspective. In this paper, to improve the accuracy problem for "appropriate recommendation" to consumers, the recommender systems are proposed in combination with context-based deep learning. This research is to combine user-based data to create hybrid Recommender Systems. The hybrid approach developed is not a collaborative type of Recommender Systems, but a collaborative extension that integrates user data with deep learning. Customer review data were used for the data set. Consumers buy products in online shopping malls and then evaluate product reviews. Rating reviews are based on reviews from buyers who have already purchased, giving users confidence before purchasing the product. However, the recommendation system mainly uses scores or ratings rather than reviews to suggest items purchased by many users. In fact, consumer reviews include product opinions and user sentiment that will be spent on evaluation. By incorporating these parts into the study, this paper aims to improve the recommendation system. This study is an algorithm used when individuals have difficulty in selecting an item. Consumer reviews and record patterns made it possible to rely on recommendations appropriately. The algorithm implements a recommendation system through collaborative filtering. This study's predictive accuracy is measured by Root Mean Squared Error (RMSE) and Mean Absolute Error (MAE). Netflix is strategically using the referral system in its programs through competitions that reduce RMSE every year, making fair use of predictive accuracy. Research on hybrid recommender systems combining the NLP approach for personalization recommender systems, deep learning base, etc. has been increasing. Among NLP studies, sentiment analysis began to take shape in the mid-2000s as user review data increased. Sentiment analysis is a text classification task based on machine learning. The machine learning-based sentiment analysis has a disadvantage in that it is difficult to identify the review's information expression because it is challenging to consider the text's characteristics. In this study, we propose a deep learning recommender system that utilizes BERT's sentiment analysis by minimizing the disadvantages of machine learning. This study offers a deep learning recommender system that uses BERT's sentiment analysis by reducing the disadvantages of machine learning. The comparison model was performed through a recommender system based on Naive-CF(collaborative filtering), SVD(singular value decomposition)-CF, MF(matrix factorization)-CF, BPR-MF(Bayesian personalized ranking matrix factorization)-CF, LSTM, CNN-LSTM, GRU(Gated Recurrent Units). As a result of the experiment, the recommender system based on BERT was the best.

The Origin of K orean Online Game Industry : Networks of 'Butterflies' (한국 온라인 게임 산업의 기원 : '나비들'의 네트워크)

  • Nam, Young
    • Journal of Science and Technology Studies
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    • v.11 no.2
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    • pp.1-30
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    • 2011
  • This paper analyzes system builders and their human networks of the Korean online game industry. By the early 2000s, Korea became one of the major online gaming countries in the world. In this period, important factors included the existence of system builders and their solid human networks. The few innovators who assisted the breakthrough of the development of the online gaming industry formed a human network in universities and IT companies. They shared innovations in information and collectively learned the conventions of the industry. In their achievement, the human networks which had already fully formed in the late 1990s became more noticeable. This paper, with its historical approach, will complement the limits shown by existing researches that, in their effort to find the causes for the success of the Korean online game industry, focus rather narrowly on the conditions of the period during which online games were becoming popular.

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A Vision Disabled-Aid using the Context of Internet of Things (사물인터넷을 이용한 시각 장애자 보조 방법)

  • Sahu, Nevadita;Jeong, Min Hyuk;Chun, Jonghoon;Kim, Sang-Kyun
    • Journal of Broadcast Engineering
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    • v.22 no.1
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    • pp.78-86
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    • 2017
  • The Internet of Things can offer disabled people the assistance and support, which is essential to achieve a good quality of life. The visually impaired people need assistance in finding locations, detecting obstacles on the way, and getting directions while moving around to reach their destination. Based on this persistent need, this paper proposes a navigation system for blind people using Internet of Things. The technologies used in our proposed system are: a smart cane containing an RFID reader and an ultrasonic sensor, a smart phone and Internet. The sensed data from the ultrasonic sensor for detecting obstacle is converted to International Standard format from ISO/IEC 23005-5 (MPEG-V Part 5). The system detects the blind person's location using the RFID tags implemented on the way. The system uses voice message in the smart phone to communicate with the blind person to lead him to his destination. The proposed system has been tested to navigate successfully in the campus.