• Title/Summary/Keyword: 발생원리

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Evaluation of Electrical Conductivity Reduction of CDI and RO for Salt Removal in Developing Countries (개발도상국 염분 제거를 위한 CDI와 RO의 전기전도도 감소 성능평가)

  • Kim, Beomgyu;Yang, Dongjin
    • Journal of Appropriate Technology
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    • v.6 no.2
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    • pp.183-189
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    • 2020
  • Developing countries are areas where many problems arise from poor drinking water infrastructure. Developing countries often use groundwater as their primary source of drinking water, which causes problems. Among them, coastal areas are easily exposed to saltwater intrusion due to their geographical characteristics. Groundwater in areas exposed to saltwater intrusion has higher salinity than usual. If you continue to consume high salinity groundwater can cause a variety of fatal effects on the human body. Therefore, various alternatives have been proposed. This study explores the applicability of CDI(Capacitive Deionization) and RO(Reverse Osmosis) for water purification systems in areas where saltwater intrusion has occurred. Therefore, we will evaluate this by conducting water purification experiment. On the other hand, the supply of electricity is also important in the operation of water purification facilities. However, in many areas of developing countries, electricity is often not available. Therefore, this study intends to calculate the power consumption required for the actual use of the filter and to include it in the evaluation.

Application of Stable Isotope Analysis for Aquaculture Organisms (수산 · 양식 생물 연구를 위한 안정동위원소 분석 기법의 소개와 활용)

  • Eun-Ji, Won;Hee Young, Yun;Bohyung, Choi;Kyung-Hoon, Shin
    • Journal of Marine Life Science
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    • v.7 no.2
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    • pp.61-73
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    • 2022
  • Stable isotope analysis (SIA) is being used in various research fields including environmental science, ecology, biogeochemistry, forensics, and archeology. In this paper, for the purpose of enhancing applications and utilizations stable isotope analysis techniques to aquaculture research, we would like to introduce the background knowledge necessary to utilize stable isotope analysis techniques. In particular, with a focus on the approach using natural abundance, the principle of fractionation (change in isotope ratio) that occurs in the process of the integration of elements into biological tissues and how stable isotope ratios are determined by fractionation. This paper is intended to suggest whether SIA is used as a valuable tool in the fields of ecology and environmental science. With the understanding of the field of stable isotopes through this paper, various applications of stable isotope ratios are expected in fisheries science and aquaculture research in the future.

Estimation of water surface evaporation in Yongdam Dam using Empirical wind function (경험적 바람공식을 적용한 용담댐 내의 수면증발량 추정)

  • Minwoo Park;Sumiya Uranchimeg;Ho-Jun Kim;Min-kyu Jung;Hyun-Han Kwon
    • Proceedings of the Korea Water Resources Association Conference
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    • 2023.05a
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    • pp.291-291
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    • 2023
  • 증발량을 산정하는 방법 중 증발접시를 활용한 방법은 하천의 증발량을 직접적으로 측정할 수 있는 장점이 있는 반면, 장기간의 증발접시를 활용한 증발량 추정은 현실적으로 쉽지 않다. 대표적인 증발량 산정식으로는 에너지 수지 및 공기동역학적 원리의 혼합적용 방법(PCE, Penman combination equation)과 경험적 바람공식(PWF, Penman wind function)이 있다. PCE로 산정된 증발량의 경우 하천 내 바닥열(bed heat flux)과 물기둥의 열저장 변화율이 장기간 규모의 순 복사량에 비해 작은 값을 가져 식에서 제외되므로 전반적으로 증발량이 과대 추정되는 문제가 발생한다. 반면, PWF로 산정한 증발량에서는 광범위한 매개변수 범위와 기상자료의 부족으로 모형의 불확실성을 증대시키는 요인으로 작용한다. 본 연구의 최종적인 목표는 하천 수로의 수면증발량을 추정하는 것이지만, 실제 하천 중심에서 증발량을 추정하기 위한 수문학적 자료는 매우 부족한 실정이다. 따라서, 본 연구에서는 유역단위에서의 증발량을 전이하는 방안을 모색하고자 하며, 구체적인 연구과정은 다음과 같다. 첫째, 유역단위 수문학적 자료를 수집하여(flux tower 자료 활용) 유역단위의 증발량을 산정한다. 둘째, PCE와 PWF으로 산정한 증발량과 관측된 증발량을 이용하여 각 식의 매개변수를 최적화한다. 마지막으로 최적화된 매개변수를 적용한 증발량과 관측값의 유사성을 분석한다. 본 연구에서는 하천단위의 증발량을 산정하기 위해 PWF을 적용하였으며 용담댐 내의 기상자료를 활용하여 산정한 증발량과 실제 용담댐 내의 수면증발량의 상관성을 분석한 결과 높은 상관성 확인할 수 있었다. 따라서 하천 주변에 증발량 추정을 위한 최소한의 기상정보가 존재하는 지역에서, 하천단위의 증발량을 산정할 수 있으며 장기간의 증발량도 산정할 수 있을 것으로 판단된다.

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The method of making Rule Cases to build Rule-Based System (규칙기반시스템의 구축에 필요한 규칙 발생 기법)

  • Zheng, BaoWei;Yeo, Jeongmo
    • Proceedings of the Korea Information Processing Society Conference
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    • 2010.04a
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    • pp.852-855
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    • 2010
  • Tree type of Rule Case will be processed by the method that provide practical Rule Case to Rule Engine that is made with procedural language beforehand, then the Rule Engine according to the condition of the special Rule Case to return result in current Rule-Based System. There are two disadvantages in the method; the first is according to specific business rule after construct the Rule Engine when the business rule changing the Rule Engine also must be changed. The second is when Rule have many conditions the Rule Engine will become very complex and the speed of processing Rule Case will become very slow. In this paper, we will propose a simplified algorithm that according to the theory of ID Tree to produce Rules which be used in Rule-Based System. The algorithm can not only produce Rules but also make sure of satisfying change of business rule by execute the algorithm. Because it is not necessary to make a Rule Engine, we will anticipate effect of increasing speed and reducing cost from Rule-Based System of applying the algorithm.

Management of Maxillary Impacted Canines (매복 상악 견치의 처치)

  • Ki-Taeg Jang
    • Journal of the korean academy of Pediatric Dentistry
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    • v.50 no.2
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    • pp.142-154
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    • 2023
  • The canine tooth is important both functionally and aesthetically, being positioned between the anterior and posterior teeth. The upper canine has the longest eruption path, forming in the deepest part of the maxillary bone and often experiencing eruption disorders, leading to significant aesthetic and functional issues. Early detection and management of canine impaction are crucial in pediatric dentistry, which focuses on tooth growth and eruption. The prevalence of maxillary canine impaction ranges from 1.1% to 3.0%. In Western populations, palatal impaction is twice as common as labial impaction, while some Korean studies report more labial impaction. Maxillary canine impaction occurs more frequently in women and is associated with various factors such as structural obstacles, pathological conditions in surrounding tissues, developmental abnormalities, and genetic factors. Labial displaced canines are linked to narrow maxillary intercanine width, total dental crowding, and skeletal Class III malocclusion. Maxillary palatal displaced canine impaction is more prevalent in patients with familial agenesis of lateral incisors or conical supernumerary lateral incisors. Understanding these factors aids in early diagnosis and appropriate intervention for canine tooth impaction, ensuring optimal oral health and aesthetics.

Three Steps Polyalphabetic Substitution Cipher Practice Model using Vigenere Table for Encryption (Vigenere 테이블을 이용한 3단계 다중 알파벳 치환 암호화 모델)

  • Nguyen Huu Hoa;Dang Quach Gia Binh;Do Yeong Kim;Young Namgoong;Si Choon Noh
    • Convergence Security Journal
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    • v.22 no.3
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    • pp.33-39
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    • 2022
  • Recently, cyberattacks on infrastructure have been continuously occurring with the starting of neutralizing the user authentication function of information systems. Accordingly, the vulnerabilities of system are increasing day by day, such as the increase in the vulnerabilities of the encryption system. In this paper, an alternative technique for the symmetric key algorithm has been developed in order to build the encryption algorithm that is not easy for beginners to understand and apply. Vigenere Cipher is a method of encrypting alphabetic text and it uses a simple form of polyalphabetic substitution. The encryption application system proposed in this study uses the simple form of polyalphabetic substitution method to present an application model that integrates the three steps of encryption table creation, encryption and decryption as a framework. The encryption of the original text is done using the Vigenère square or Vigenère table. When applying to the automatic generation of secret keys on the information system this model is expected that integrated authentication work, and analysis will be possible on target system. ubstitution alphabets[3].

Development of ViscoElastoPlastic Continuum Damage (VEPCD) Model for Response Prediction of HMAs under Tensile Loading (인장하중을 받는 아스팔트 혼합물의 점탄소성 모형의 개발)

  • Underwood, B. Shane;Kim, Y. Richard;Seo, Youngguk;Lee, Kwang-Ho
    • KSCE Journal of Civil and Environmental Engineering Research
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    • v.28 no.1D
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    • pp.45-55
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    • 2008
  • The objective of this research was to develop a VEPCD (ViscoElastoPlastic Continuum Damage) Model which is used to predict the behavior of asphalt concrete under various loading and temperature conditions. This paper presents the VEPCD model formulated in a tension mode and its validation using four hot mix asphalt (HMA) mixtures: dense-graded HMA, SBS, CR-TB, and Terpolymer. Modelling approaches consist of two components: the ViscoElastic Continuum Damage (VECD) mechanics and the ViscoPlastic (VP) theory. The VECD model was to describe the time-dependent behavior of HMA with growing damage. The irrecoverable (whether time-dependent or independent) strain has been described by the VP model. Based on the strain decomposition principle, these two models are integrated to form the VEPCD model. For validating the VEPCD model, two types of laboratory tests were performed: 1) a constant crosshead strain rate tension test, 2) a fatigue test with randomly selected load levels and frequencies.

Resistance as a Category in Southeast Asian Cultural History : A Millenarian Revolt in Colonial Burma (동남아 문화사의 한 범주로서의 '저항' : 식민지 버마의 천년왕국 봉기)

  • AUNG-THWIN, Maitrii
    • SUVANNABHUMI
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    • v.3 no.2
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    • pp.31-77
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    • 2011
  • 식민지하 동남아 천년왕국 운동에 대한 오늘날의 해석들은 그 주체인 농민들을 식민주의를 개념화하고 저항하는 동기와 조건 그리고 상징을 제공하는 토착 지식의 전수자로 간주한다. 종말론과 저항에 대한 관심의 대부분은 농민연구나 지역연구 학자들로부터 유래하며, 이들은 봉기에 대한 과거의 묘사들이 토착의 정신세계를 간과했거나 국가이념을 저항세력들의 결집원리로 과대 포장한 것에 주의를 기울인다. 천년왕국 봉기에 관한 글들에서 제공하는 해석들은 동남아 신념 체계에 관한 독립적인 관점을 제공할 뿐만 아니라, 인식론적 측면에서 식민지국가들을 이와 같은 전통에서 단절시키고 있다. 영국 식민지하에서 최대의 농민반란인 서야쌍 봉기(1930-1932)는 오늘날 이와 같은 천년왕국 운동의 정수를 보여주는 사례로 간주된다. 학자들은 수천 명의 농민들로 하여금 버마인의 권위를 되찾고, 불교를 회복시키며, 식민통치로 인해 낳은 사회-경제적 부조리를 일소시킬 그들의 왕으로 믿게 만든 한 농부의 흥미로운 이야기를 묘사하고 있다. 일련의 반란이 미신에 의해 추동되었다고 간주한 식민지 관찰자들과는 달리 이후의 역사가들은 그 반란이 불교를 재건하고 태평성대로 인도할 미래부처인 미륵불의 현신에 대한 믿음의 표현이라고 해석했다. 이러한 학자들에게 서야쌍 봉기는 어떻게 동남아 사람들의 감수성이 식민지의 사회-경제적 압력 속에서도 지속되었으며, 상좌불교의 예언이 토착의 문화적 토양에 얼마나 깊이 내재해 있는지를 말해주는 사례였다. 경험적 관점에서 본 글은 서야쌍 봉기의 근원을 재해석함으로써 천년왕국 봉기에 관한 글들이 대부분 식민지적 문서화 작업과 종교를 과장되고 세속화된 화술로 믿게 하려고 지역연구자들의 산물임을 밝히고 있다. 개념적 관점에서 본고는 버마에서 일어난 천년왕국 운동의 역사적 구성에 대한 식민주의의 역할을 보다 면밀히 관찰하였다. 또한 식민지법, 학문, 그리고 식민지하 버마 농촌에서 발생한 종교적 저항에 대한 우리들의 이해를 상호 연결하는 인식론적 관계를 탐구했다. 그리하여 본고는 천년왕국 해석이 이 시기에 공존했던 다른 유형의 불교정치적 형태를 어떻게 왜곡했는가를 밝히고 있다.

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Weight Recovery Attacks for DNN-Based MNIST Classifier Using Side Channel Analysis and Implementation of Countermeasures (부채널 분석을 이용한 DNN 기반 MNIST 분류기 가중치 복구 공격 및 대응책 구현)

  • Youngju Lee;Seungyeol Lee;Jeacheol Ha
    • Journal of the Korea Institute of Information Security & Cryptology
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    • v.33 no.6
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    • pp.919-928
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    • 2023
  • Deep learning technology is used in various fields such as self-driving cars, image creation, and virtual voice implementation, and deep learning accelerators have been developed for high-speed operation in hardware devices. However, several side channel attacks that recover secret information inside the accelerator using side-channel information generated when the deep learning accelerator operates have been recently researched. In this paper, we implemented a DNN(Deep Neural Network)-based MNIST digit classifier on a microprocessor and attempted a correlation power analysis attack to confirm that the weights of deep learning accelerator could be sufficiently recovered. In addition, to counter these power analysis attacks, we proposed a Node-CUT shuffling method that applies the principle of misalignment at the time of power measurement. It was confirmed through experiments that the proposed countermeasure can effectively defend against side-channel attacks, and that the additional calculation amount is reduced by more than 1/3 compared to using the Fisher-Yates shuffling method.

A real-time image-based sea fog observation system based on local lighthouse (항로표지 거점을 활용한 실시간 영상기반 해양안개 관측시스템 구축)

  • Mookun Kim;In-kwon Jang;Hyeong-ui Lee
    • Proceedings of the Korean Institute of Navigation and Port Research Conference
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    • 2023.11a
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    • pp.23-26
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    • 2023
  • In the past, in observing the sea fog on the major sea route and providing real-time information for the safe operation of ships, a visibility sensor or a fog detector with similar operating principles was installed to observe local fog near the place where it was installed. However, it was somewhat unreasonable to immediately provide sea fog observation information to ships and users because the reliability of real-time observation information was somewhat low due to pollution caused by dust, salt, and pollen, or malfunctions of detection sensors by organisms such as spider webs. From 2019 to 2022, the Korea Meteorological Administration and the Ministry of Oceans and Fisheries collaborated to build a more reliable real-time image-based sea fog observation system in 100 regions of the Lighthouse on major sea routes across the country to collect reliable sea fog observation information every 10 minutes and perform real-time public service(webpage).

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