• 제목/요약/키워드: The fourth generation

검색결과 331건 처리시간 0.03초

간섭 상쇄 기법과 장기 누적 기법을 이용한 WiBro 지상파 측위 시스템의 가청성 향상 (Enhancement of Hearability in Geolocation Using Mobile WiMAX Network with Interference Cancellation and Long Integration)

  • 박지원;임정민;성태경
    • 제어로봇시스템학회논문지
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    • 제18권4호
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    • pp.375-383
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    • 2012
  • Together with the GPS-based approach, geolocation through mobile communication networks is a key technology for location-based service. Since the Mobile WiMAX system is considered as a candidate for fourth-generation mobile systems, it is important to investigate its location capability. The geolocation of Mobile WiMAX can be realized when the preamble symbols in the down-link channel are appropriately used for a TDOA (Time-Difference-of-Arrival) approach. However, the cellular structure of Mobile WiMAX inevitably generates co-channel interference, and it is difficult for the mobile terminal to acquire distance measurements from multiple base stations. Therefore, for geolocation via multilateration using the Mobile WiMAX network, it is very important to increase hearability. This paper proposes a geolocation method for Mobile WiMAX which employs interference cancellation and preamble signal overlapping for the enhancement of hearability. A novel interference cancellation strategy for complex-valued Mobile WiMAX signals is presented which has an iterative structure. Simulation results show that the proposed geolocation method provides the user's position with an accuracy of less than 20 m through the Mobile WiMAX cellular network if there is no multi-path or NLOS (None-Line-of-Sight).

뉴실버 여성의 선호 섬유와 재질감에 대한 연구 (New-silver women's fiber and material property preferences)

  • 최인려
    • 복식문화연구
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    • 제24권1호
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    • pp.107-113
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    • 2016
  • The purpose of this study was to examine new-silver women's fiber and material property preferences and purchasing behaviors. The survey subjects were 115 new-silver women ranging in age from 50 to 60 years old. This study utilized a questionnaire as a measurement tool. The results of this study were as follows: First, the home ownership rate of the participants in this was 81.4%, and 54.9% of them had a bachelor's degree or higher. Therefore, they turned out to be a new silver generation with higher education and stable income and assets. Second, regarding their purchasing behaviors, it was shown that they purchased the largest amount of clothing for themselves and their spouses, children, and grandchildren at the change of seasons. Third, with regard to their average spending on clothing, when they purchased clothing for themselves, it was shown that they purchased clothing at the price of KRW 500,000 or above for themselves but not for their family members. Fourth, their favorite type of fiber was synthetic fiber, and their favorite material property was heaviness, followed by roughness, stiffness, bulkiness, and glossiness. Moreover, with regard to their favorite functional textile, it was shown that the highest percentage of them preferred vitamin textiles, followed by ocher and scented textiles.

실활치 표백술 후 치관내 수복물의 미세누출에 관한 비교 (THE COMPARISON OF MICROLEAKAGE ON INTRACORONAL RESTORATION AFTER NON-VITAL BLEACHING)

  • 정재은;이희주;허복
    • Restorative Dentistry and Endodontics
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    • 제28권1호
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    • pp.57-63
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    • 2003
  • The purpose of the present study were to evaluate microleakage of a fourth generation dentin-bonding agent following a walking bleaching treatment, to determine the effect of temporary postbleaching dressing with calcium hydroxide on microleakage and to investigate the effect of delayed intracoronal restoration on microleakage. The results of this study were as follows : 1. Bleached groups showed more microleakage than unbleached group 2. Immediately restored group following bleaching procedure showed the highest microleakage score. 3. One-week delayed restorations showed less microleakage but there were no statistically significant difference between group II and III. 4. Provisional dressing with calcium hydroxide had no influence on microleakage. It is necessary to know the time that has elapsed from the bleaching treatment to the restoration procedure to achieve optimal seal, as well as to reduce the risk of microleakage in adhesive restoration.

WiBro 서비스를 이용한 응용프로그램의 취약점 분석 및 보안 대책 연구 (A Study of Security Measures and Vulnerability Analysis on the Application using WiBro Service)

  • 천우성;박대우
    • 한국정보통신학회:학술대회논문집
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    • 한국정보통신학회 2012년도 춘계학술대회
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    • pp.479-482
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    • 2012
  • WiBro(Wireless Broadband)서비스는 우리나라에서 세계표준화한 4세대 통신이다. WiBro 통신기반을 사용한 인터넷기반 응용프로그램을 통한 서비스이용이 늘어나고 있다. WiBro 서비스에서 인터넷 기반 응용프로그램으로 서비스 이용할 때, 응용프로그램의 취약점을 분석할 필요가 있다. 본 논문에서는 WiBro 서비스에서 인터넷을 이용할 때 취약점을 분석하고, 인터넷기반 응용프로그램에 대한 해킹공격이 발생할 수 있는 취약점을 분석한다. WiBro 서비스와 응용프로그램의 취약점 분석을 통해 보안대책을 연구한다.

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WiBro 서비스를 이용한 응용프로그램의 취약점 분석 및 보안 대책 연구 (A Study of Security Measures and Vulnerability Analysis on the Application using WiBro Service)

  • 천우성;박대우
    • 한국정보통신학회논문지
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    • 제16권6호
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    • pp.1217-1222
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    • 2012
  • WiBro(Wireless Broadband)서비스는 우리나라에서 세계표준화한 4세대 통신이다. WiBro 통신기반을 사용한 인터넷기반 응용프로그램을 통한 서비스이용이 늘어나고 있다. WiBro 서비스에서 인터넷기반 응용프로그램으로 서비스 이용할 때, 응용프로그램의 취약점을 분석할 필요가 있다. 본 논문에서는 WiBro 서비스에서 인터넷을 이용할 때 취약점을 분석하고, 인터넷기반 응용프로그램에 대한 해킹공격이 발생할 수 있는 취약점을 분석한다. WiBro 서비스와 응용프로그램의 취약점 분석을 통해 보안대책을 연구한다.

여대생의 성역할 태도에 따른 의복관여와 의복소비행동에 대한 고찰 (A Study on the Clothing Involvement and Clothing Consumption Behavior of Female University Students according to Gender Role Attitude)

  • 최미영
    • 복식
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    • 제60권8호
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    • pp.15-28
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    • 2010
  • The purpose of this study was to investigate how gender role attitudes affect clothing involvement and clothing consumption behaviors in young female generation by changing the traditional sex role stereotype. For the research, the survey was conducted for a month from June 15 to July 15, 2009. Data was collected a total of 368 questionnaires from 20's female university students and analyzed 301 questionnaires with SPSS 12.0. The results were as follows. First, the results of factor analysis on gender role attitudes confirmed the multifactorial theory of gender schema: modern masculinity, conservative gender roles, modern feminity based on emotion, gender role openness, and traditional feminity. Second, gender role attitude of female university students was a little conservative but flexible to accommodate masculinity and active in the emotion expression. Third, gender role attitudes had important effects on clothing involvement which was identified into 4 different factors; fashion involvement, clothing interest, performance risk, and social psychological risk. Fourth, gender role attitudes were related with clothing consumption behaviors as like shopping orientation, on-going information search behavior and brand loyalty because of needs for innovation, exhibition and differentiation. Therefore, it was concluded that not only 'androgynous' from modern feminity based on emotion but also 'masculinity' was applied to important fashion marketing strategic tools by statically affecting female consumer's clothing involvement and clothing behaviors.

시각화방법을 이용한 객체지향프로그래밍 교육에 관한 연구 (A Study on Object-Oriented Programming Education using Visualization Method)

  • 신우창
    • 정보교육학회논문지
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    • 제21권5호
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    • pp.557-565
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    • 2017
  • 4차 산업혁명시대를 맞이하여 학생들에 대한 프로그래밍 교육이 더욱 중요시되고 있다. 그러나, 학생들이 프로그래밍 능력을 습득하는 데에는 많은 시간과 연습이 필요하다. 특히, 산업현장에서 널리 사용되고 있는 JAVA, C++와 같은 객체지향언어를 학습하는데 있어서 학생들은 더욱 많은 어려움을 느낀다. 본 논문에서는 객체지향프로그래밍 개념을 교육하고, 기능을 이해하며, 소스코드 분석 및 이해향상에 도움을 줄 수 있는 객체 상호작용 시각화 방법을 제안한다. 제안된 시각화 방법은 기존 소스코드를 자동적으로 변경하여 프로그램 실행과 동시에 객체들이 동작하는 모습을 시각적으로 보인다.

Structural safety reliability of concrete buildings of HTR-PM in accidental double-ended break of hot gas ducts

  • Guo, Quanquan;Wang, Shaoxu;Chen, Shenggang;Sun, Yunlong
    • Nuclear Engineering and Technology
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    • 제52권5호
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    • pp.1051-1065
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    • 2020
  • Safety analysis of nuclear power plant (NPP) especially in accident conditions is a basic and necessary issue for applications and commercialization of reactors. Many previous researches and development works have been conducted. However, most achievements focused on the safety reliability of primary pressure system vessels. Few literatures studied the structural safety of huge concrete structures surrounding primary pressure system, especially for the fourth generation NPP which allows existing of through cracks. In this paper, structural safety reliability of concrete structures of HTR-PM in accidental double-ended break of hot gas ducts was studied by Exceedance Probability Method. It was calculated by Monte Carlo approaches applying numerical simulations by Abaqus. Damage parameters were proposed and used to define the property of concrete, which can perfectly describe the crack state of concrete structures. Calculation results indicated that functional failure determined by deterministic safety analysis was decided by the crack resistance capability of containment buildings, whereas the bearing capacity of concrete structures possess a high safety margin. The failure probability of concrete structures during an accident of double-ended break of hot gas ducts will be 31.18%. Adding the consideration the contingency occurrence probability of the accident, probability of functional failure is sufficiently low.

Application of Deep Learning to Solar Data: 2. Generation of Solar UV & EUV images from magnetograms

  • Park, Eunsu;Moon, Yong-Jae;Lee, Harim;Lim, Daye
    • 천문학회보
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    • 제44권1호
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    • pp.81.3-81.3
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    • 2019
  • In this study, we apply conditional Generative Adversarial Network, which is one of the deep learning method, to the image-to-image translation from solar magentograms to solar UV and EUV images. For this, we train a model using pairs of SDO/AIA 9 wavelength UV and EUV images and their corresponding SDO/HMI line-of-sight magnetograms from 2011 to 2017 except August and September each year. We evaluate the model by comparing pairs of SDO/AIA images and corresponding generated ones in August and September. Our results from this study are as follows. First, we successfully generate SDO/AIA like solar UV and EUV images from SDO/HMI magnetograms. Second, our model has pixel-to-pixel correlation coefficients (CC) higher than 0.8 except 171. Third, our model slightly underestimates the pixel values in the view of Relative Error (RE), but the values are quite small. Fourth, considering CC and RE together, 1600 and 1700 photospheric UV line images, which have quite similar structures to the corresponding magnetogram, have the best results compared to other lines. This methodology can be applicable to many scientific fields that use several different filter images.

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Similarity measurement based on Min-Hash for Preserving Privacy

  • Cha, Hyun-Jong;Yang, Ho-Kyung;Song, You-Jin
    • International Journal of Advanced Culture Technology
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    • 제10권2호
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    • pp.240-245
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    • 2022
  • Because of the importance of the information, encryption algorithms are heavily used. Raw data is encrypted and secure, but problems arise when the key for decryption is exposed. In particular, large-scale Internet sites such as Facebook and Amazon suffer serious damage when user data is exposed. Recently, research into a new fourth-generation encryption technology that can protect user-related data without the use of a key required for encryption is attracting attention. Also, data clustering technology using encryption is attracting attention. In this paper, we try to reduce key exposure by using homomorphic encryption. In addition, we want to maintain privacy through similarity measurement. Additionally, holistic similarity measurements are time-consuming and expensive as the data size and scope increases. Therefore, Min-Hash has been studied to efficiently estimate the similarity between two signatures Methods of measuring similarity that have been studied in the past are time-consuming and expensive as the size and area of data increases. However, Min-Hash allowed us to efficiently infer the similarity between the two sets. Min-Hash is widely used for anti-plagiarism, graph and image analysis, and genetic analysis. Therefore, this paper reports privacy using homomorphic encryption and presents a model for efficient similarity measurement using Min-Hash.