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Asynchronous Multilevel Search Strategy for Fast Acquisition of AltBOC Signals

  • Kim, Binhee;Kong, Seung-Hyun
    • Journal of Positioning, Navigation, and Timing
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    • v.4 no.4
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    • pp.161-171
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    • 2015
  • Alternative binary offset carrier (AltBOC) signals can be approximated by four synchronized direct sequence spread spectrum (DSSS) signals, each pair of which is a quadrature phase shift keyed (QPSK) signal at a different frequency. Therefore, depending on the strength of an incoming AltBOC signal, an acquisition technique can reduce the mean acquisition time (MAT) by searching the four DSSS signals asynchronously; the search for each of the four DSSS signals can start at one of the evenly separated hypotheses on the two-dimensional hypothesis space. And detection sensitivity can be improved by multiple levels when different numbers of search results for the same hypothesis are combined. In this paper, we propose a fast AltBOC acquisition technique that has an asynchronous search strategy and efficiently utilizes the output of the four search results to increase the sensitivity level when sensitivity improvement is needed. We provide a complete theoretical analysis and demonstrate with numerous Monte Carlo simulations that the MAT of the proposed technique is much smaller than conventional AltBOC acquisition techniques.

Mediation Effect of Appearance Management Behavior on the Relationship between Satisfaction of Personal Image and Job Search Efficacy among Female College Students (여대생의 퍼스널 이미지 만족도와 구직효능감과의 관계에서 외모관리행동의 매개효과)

  • Kim, Mikyung
    • Journal of Fashion Business
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    • v.22 no.4
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    • pp.160-177
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    • 2018
  • The objective of this study was to investigate mediation effect of appearance management behavior on the relationship between satisfaction of personal image and job search efficacy. Based on previous studies on components of personal image, appearance management behaviors, and job search efficacy, questionnaire items were developed. For this study, we conducted a questionnaire survey among 422 students from women's university in Seoul. Statistical analyses were performed using SPSS 23. Results are as follows. First, there were positive and moderate bivariate correlations among satisfaction of personal image, appearance management behavior, and job search efficacy. Second, satisfaction of personal image was found to have a partially significant effect on job search efficacy while satisfaction of internal image, visual image, and social image had a positive effect on job search skill. Satisfaction of internal image had a positive effect on job search strength. However, satisfaction of visual image or social image did not have a significant effect on job search strength. Third, fashion management behavior among components appearance management behavior could partially mediate the relationship between satisfaction of personal image and job search efficacy, indicating that satisfaction of internal image and visual image among components personal image not only has a direct effect on job search skill among job search efficacy, but also has an indirect effect on job search skill by affecting fashion management behavior. These results suggest that it is important to build personal image effectively and increase satisfaction with oneself through active appearance management behavior to improve job search efficacy.

Dynamic Characteristics and Stability of an Infrared Search and Track (적외선 탐색 및 추적장비의 동적 특성 및 안정화)

  • Choi, Jong-Ho;Park, Yong-Chan;Lee, Joo-Hyoung;Choi, Young-Soo
    • Journal of the Korea Institute of Military Science and Technology
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    • v.11 no.2
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    • pp.116-124
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    • 2008
  • Current paper investigates the dynamic behavior and stability of an infrared search and track subjected to external disturbance having gimbal structure with three rotating axes keeping constant angular velocity in the azimuth direction. Euler-Lagrange equation is applied to derive the coupled nonlinear dynamic equation of motion of infrared search and track and the characteristics of dynamic coupling are investigated. Two equilibrium points with small variations from the nonlinear coupling system are derived and the specific condition from which a coupled equation can be three independent equations is derived. Finally, to examine the stability of system, Lyapunov direct method was used and system stability and stability boundaries are investigated.

Direct Search Methods for Nonlinear Optimization Problem used ART Theory

  • Son, Jun-Hyeok;Seo, Bo-Hyeok
    • Proceedings of the KIEE Conference
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    • 2006.07d
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    • pp.1830-1831
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    • 2006
  • In this paper, the search is conducted along each of the coordinate directions for finding the minimum. If $e_i$ is the unit vector along the coordinate direction i, we determine the value a, minimizing f(a)= $f(x+ae_i)$, where a is a real number. A move is made to the new point $x+a_ie_i$ at the end of the search along the direction i. In an n dimensional problem, we define the search along all the directions as one stage. The function value at the end of the stage is compared to the value at the beginning of the stage in establishing the convergence. The gradient appears to be zero at point. We can safeguard this by introducing an acceleration step of one additional step along the pattern direction developed by moves along the coordinate directions.

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Performance Analysis of Burst-Format DS-SS Acquisition system Using a Serial-Maximum Likelihood Search- A Modified State Transition diagram Approach (직렬-최대 공차 탐색을 사용한 비스트형 DS-SS 초기 동기 시스템의 성능 분석-수정된 상태 천이도 접근법-)

  • 이독욱;김근묵;황금찬
    • Journal of the Korean Institute of Telematics and Electronics A
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    • v.28A no.11
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    • pp.855-865
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    • 1991
  • A simple method for analysis of serial search burst-format direct-sequence spread-spectrum (DS-SS) code acquisition system had been recently proposed, and therein, the effect of the code autocorrelation sidelobes on the performance of DS-SS code acquisition system has been assessed [4],[5]. In this paper, a new hybrid scheme which combines the serial search with maximum likelihood search is proposed to eliminate the deleterious effect of code autocorrelation sidelobes, and the performance is analyzed for the additive withe Gaussian noise (AWGN) channels. To analyze the performance of this system, we have generalized the method used in [4],[5] to arbitrary burst-format DS-SS acquisition schemes. The results show that a new hybrid scheme has good immunity against the effect of code autocorrelation sidelobes. Thevalidity of the presented approach has been confirmed form the results of simulation.

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Improved Piracy Site Detection Technique using Search Engine

  • Kim, Eui-Jin;Kim, Deuk-Hun;Kwak, Jin
    • KSII Transactions on Internet and Information Systems (TIIS)
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    • v.16 no.7
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    • pp.2459-2472
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    • 2022
  • With the increase in copyright content exports to overseas markets due to the recent globalization of the Korean culture, the added value of the Korean digital content market is increasing at a significant rate. As such, as the size of the copyright market increases, different piracy sites have emerged that generate profits by illegally distributing works without the permission of the copyright holders, resulting in direct and indirect damage to these copyright holders. The existing copyright detection methods used in public institutions for solving this problem are limited, while the piracy sites are ever-changing. Methods are being continuously developed to achieve better detection results. To this end, it is possible to detect the latest infringement site domain by detecting the infringement site domain that is constantly changed through the search engine. This paper proposes an improved piracy site detection method using a search engine to prevent the damage caused by piracy sites.

An Analysis of Key Words Related to Traditional Korean Medicine Using Big Data of Two Search Engines (2대 포털사이트 빅데이터를 이용한 한방관련 키워드 분석)

  • Ahn, Jung-Yun;Keum, Ga-Jeong;Jang, Ah-Ryeong;Song, Ji-Chung
    • The Journal of Korean Medical History
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    • v.30 no.2
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    • pp.45-61
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    • 2017
  • Objectives : This research aims to investigate the consumer's interest in the Korean Medicine (KM) industry by using Google-trends and Naver-Data lab. A quick and uncomplicated way for those who are already involved with KM industry but do not have expertise in utilizing Big-data searches, is introduced. Methods : 'Direct keyword' was set by FGI (Focus Group Interview) and 'Detailed keyword' was set by using relevant word search and autocomplete search functions in the search engine. By inquiring Naver-Data lab, keyword search volumes are compared by age and sex, date range, and originating region of the researcher. It is possible to determine whether the data is reliable or authentic through examining the associated query. Selected direct keywords used through FGI (Focus Group Interview) were 'Acupuncture', 'Herbal Medicine', 'Cupping', 'Musculoskeletal Disease', 'Diet', and 'Stemina'. Based on these keywords, the following results were derived from the keyword analysis. Results : From August 2016, there was a noticeable surge of interest in men's 'Cupping'. The search for 'Diet' increased in the second quarter of 2016 from all ages. The search volume of 'Stemna' for individuals in their 20s is higher than that of those in their 30s or 40s'. Researchers from the region of Chungcheongbuk-do had a higher level of interest in analgesics and less interest in Korean Medicine. There is a greater interest in the KM market from European countries and America, than from Korea, China, and other Asian countries. Discussion : Despite the limitations of the research, it is meaningful to introduce a quick and easy data search method to compare information by age, sex, and region. Conclusion : The future of research into Korea Medicine and this market is confirmed by our data results which indicate interest from Europe, the United States, and other western countries, but less interest from Korea, China and other Asian countries.

The Effects of Information-searching for Korean Food Brand on Risk Perception and Preference (한식브랜드의 정보탐색이 위험지각과 애호도에 미치는 영향)

  • Kim, Jung-Soo
    • Culinary science and hospitality research
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    • v.23 no.2
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    • pp.189-202
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    • 2017
  • The purpose of the study is to investigate the effects of information search for Korean food brand on perceived risk and preference. To achieve this goal, using 10 exemplary restaurants appointed as Korean food brands in Seoul, a questionnaire survey was used to collect data through interview. Using the SPSS 21.0. total 296 responses were analyzed to test the relationship among variables. The findings are as follows. First, information search for Korean food brand showed that all external search, internal search and direct experience had a positive effect on preference. Second, there was no difference between information search for Korean food brand, risk perception and preference according to gender, but there was a significant difference between information search for Korean food brand, risk perception, and preference according to their age. Third, indifference moderated the relationship between external and internal information search and Korean food preference. Fourth, maladjustment moderated the relationship between external information and direct experience for Korean food preference.

A Study on Direct Cooling and Indirect Cooling in Etching Process Cooling System (식각 공정용 냉각시스템에서의 직접 냉각 방식과 간접 냉각 방식에 관한 연구)

  • Jang, Kyungmin;Kim, Kwangsun
    • Journal of the Semiconductor & Display Technology
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    • v.17 no.3
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    • pp.100-103
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    • 2018
  • Due to the plasma applied from the outside, which acts as an etchant during the etching process, considerable heat is transferred to the wafer and a separate cooling process is performed to effectively remove the heat after the process. In this case, a direct cooling method using a refrigerant is suitable for cooling through effective heat exchange. The direct cooling method using the refrigerant using the latent heat exchange is superior to the cooling method using the sensible heat exchange. Therefore, in this paper, AMESim is used to design a direct refrigerant cooling system using latent heat exchange simulator was built.The constructed simulator is reliable compared with the actual experimental results. It is expected that this simulator will help to design and search for optimal process conditions.

Construction of a Database for New Bioactive Compounds and Development of Search Systems

  • Park, Kie Jung;Yong Ha Park
    • Journal of Microbiology and Biotechnology
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    • v.6 no.1
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    • pp.54-59
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    • 1996
  • In the research and development of bioactive compounds, determining whether a compound is novel is necessary at almost every stage. Fast and efficient determination can save money, time and effort, and thereby increase efficiency. Analysis and investigation of empirical results for previously determined compounds is also important in such research. The need to communicate research findings between workers is necessary. In effect, a systematic, centralized communication medium is required. Therefore, we have developed and constructed our own database and search systems. We have developed a search system on DOS and constructed a source file for our own database. To support multiple users, we have developed another specific and comprehensive search system, including powerful searching and output management features. The system has been developed to be simple and user-friendly, using the curses library of UNIX, while still allowing complicated queries to be performed easily with simple full-screen facilities. This UNIX version will be available for use by researchers on a computer network and is expected to make numerous contributions to basic research in universities. It will also have direct applications for institutes and industry.

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