• Title/Summary/Keyword: frequency measurement

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Design and Fabrication of Miniaturized Dual-bandpass filter Using Rectangular ring resonator and Interdigital capacitive feeding-structure (Rectangular Ring 공진기와 Interdigital Capacitive 급전구조를 이용한 소형화된 이중대역통과필터의 설계 및 제작)

  • Yoon, Hyun-Soo;Kang, Sang-Rok;Choi, Byoung-Ha
    • Journal of Navigation and Port Research
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    • v.31 no.5 s.121
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    • pp.415-420
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    • 2007
  • In this paper, we have designed and fabricated a new type of bandpass-filter that used rectangular ring and interdigital capacitive feeding-structure. The filter is applied the modified rectangular ring and interdigital capacitive feeding-structure in patch, which reduce rho size of filter and IEEE 802. 11 correspond to wireless LAN domain(2.45GHz and 5.2GHz) for operating. As a result, the design and fabrication process of the filter become simple and the size of it is reduced more than 60% compared with RF filter are available conventional PEMBF(Parallel Edge-coupled Microstrip Bandpass Filter) of accounted circuit by minimum stage, measurement result of fabricated filter, center frequence is down 2.408GHz and 5.075GHz. input return loss is -39.169dB at 2.408GHz, -40.922dB at 5.075GHz. insertion loss is -0.437dB at 2.408GHz, -1.669dB at 5.075GHz.

On the Study of Initializing Extended Depth of Focus Algorithm Parameters (Extended Depth of Focus 알고리듬 파라메타 초기설정에 관한 연구)

  • Yoo, Kyung-Moo;Joo, Hyo-Nam;Kim, Joon-Seek;Park, Duck-Chun;Choi, In-Ho
    • Journal of Broadcast Engineering
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    • v.17 no.4
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    • pp.625-633
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    • 2012
  • Extended Depth of Focus (EDF) algorithms for extracting three-dimensional (3D) information from a set of optical image slices are studied by many researches recently. Due to the limited depth of focus of the microscope, only a small portion of the image slices are in focus. Most of the EDF algorithms try to find the in-focus area to generate a single focused image and a 3D depth image. Inherent to most image processing algorithms, the EDF algorithms need parameters to be properly initialized to perform successfully. In this paper, we select three popular transform-based EDF algorithms which are each based on pyramid, wavelet transform, and complex wavelet transform, and study the performance of the algorithms according to the initialization of its parameters. The parameters we considered consist of the number of levels used in the transform, the selection of the lowest level image, the window size used in high frequency filter, the noise reduction method, etc. Through extended simulation, we find a good relationship between the initialization of the parameters and the properties of both the texture and 3D ground truth images. Typically, we find that a proper initialization of the parameters improve the algorithm performance 3dB ~ 19dB over a default initialization in recovering the 3D information.

Wave and surface current measurement with HF radar in the central east coast of Korea (동해중부에서 HF Radar를 이용한 파랑 및 해수유동 관측)

  • Kim, Moo-Hong;Kim, Gyung-Soo;Kim, Hyeon-Seong
    • Journal of Advanced Marine Engineering and Technology
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    • v.38 no.6
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    • pp.771-780
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    • 2014
  • We installed HF Radar of Array type in Site A and Site B, observing the real-time wave and current in the central East coast of Korea. WERA(WavE RAdar) in this research uses HF Radar of Array Type with frequency range of 24.525 MHz, developed by Helzel, Germany. Each site is a 8-Channel system consisting of four transmitters and eight receivers, generating wave and current data, being observed every thirty minutes at the present time. HF Radar has grid resolution of an interval of 1.5 km using bandwidth of 150 kHz; The wave data covers an observation range of about 25 km, and the current data covers the maximum observation range of about 50 km. The Wave data observed by HF Radar was compared and verified with the AWAC data observed in the research sites. MIT also compared the Current data observed by HF Radar with Monthly the East sea average surface current and current flow pattern provided by KOHA(Korea Hydrographic and oceanographic Administration). The regression line and deviation of the comparison data of Wave was calculated by Principal Component Analysis, which showed correlation coefficient 0.86 and RMSD 0.186. Besides, data analysis of long-term changes of the current in the East coast showed that, during August and September, the North Korean Cold Current flow into the southward direction and the East Korean Warm Current flow into the northward direction in the coast.

Electrical and Rheological Behaviors of VGCF/Polyphenylene Sulfide Composites (기상성장 탄소섬유/폴리페닐렌설파이드 복합체 제조 및 전기적$\cdot$유변학적 거동)

  • Noh, Han-Na;Yoon, Ho-Gyu;Kim, Jun-Kyung;Lee, Hyun-Jung;Park, Min
    • Polymer(Korea)
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    • v.30 no.1
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    • pp.85-89
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    • 2006
  • The effect of vapor grown carbon fiber (VGCF) contents on electrical and rheological properties of VGCF filled polyphenylene sulfide (PPS) composites prepared through melt mixing using a twin screw exruder was studied. This method was proved to be quite effective to produce good dispersion of VGCF in the matrix even for highly filled PPS. From the dependence of the electrical conductivity on VGCF content, the percolation phenomena began to occur above $10\;wt\%$. While there is only a marginal increase of viscosity for 1 and $5\;wt\%$ VGCF filled PPS, the composites containing $10\;wt\%$. While VGCF showed abrupt increase in viscosity as well as flattening of frequency vs modulus curve, indicating a transition from a liquid-like to a solid-like behavior due to the creation of VGCF network. This result agrees well to the fact that the network formation in the composite can be composite by rheological property dependence on filler content as well as by electrical conductivity measurement.

A Study on Selection Process of Web Services Based on the Multi-Attributes Decision Making (다중 속성 의사결정에 의한 웹 서비스 선정 프로세스에 관한 연구)

  • Seo Young-Jun;Song Young-Jae
    • The KIPS Transactions:PartD
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    • v.13D no.4 s.107
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    • pp.603-612
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    • 2006
  • Recently the web service area is rapidly growing as the next generation IT paradigm because of increase of concern about SOA(Services-Oriented Architecture) and growth of B2B market. Since a service discovery through UDDI(Universal Description, Discovery and Integration) is limited to a functional requirement, it is not considered an effect on frequency of service using and reliability of mutual relation. That is, a quality as nonfunctional aspect of web service is regarded as important factor for a success between consumer and provider. Therefore, the web service selection method with considering the quality is necessary. This paper suggests the agent-based quality broker architecture and selection process which helps to find a service providing the optimum quality that the consumer needs in a position of service consumer. A theory of agent is accepted widely and suitable for proposed system architecture in the circumstance of distributed and heterogeneous environment like web service. In this paper, we considered the QoS and CoS in the evaluation process to solve the problem of existing researches related to the web service selection and used PROMETHEE(Preference Ranking Organization MeTHod for Enrichment Evaluations) as an evaluation method which is most suitable for the web service selection among MCDM approaches. PROMETHEE has advantages that solve the problem that a pair-wise comparison should be performed again when comparative services are added or deleted. This paper suggested a case study with the service composition scenario in order to verify the selection process. In this case study, the decision making problem was described on the basis of evaluated values for qualities from a consumer's point of view and the defined service level.

The effect of Life Stress, Cultural Adaptation Stress and Academic Satisfaction in Chinese Students Studying in the Republic of Korea. - Target on Beauty Major College Students. (중국인 유학생의 생활스트레스 및 문화적응스트레스가 학업만족도에 미치는 영향 - 미용전공 대학생을 대상으로)

  • Lim, Sang-Ran;Lee, Ji-An
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.18 no.12
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    • pp.189-199
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    • 2017
  • This study investigated the effects of life stress, cultural adaptation stress, and academic satisfaction amongst a total of 283 20's Chinese students majoring in cosmetology at colleges in Seoul. For this, data was collected from February to March 2017. The frequency analysis was conducted to verity the general characteristic of Chinese student studying in Korea who are study objects while utilizing SPSS Statistics V22.0 for data processing and analysis while the factor analysis and reliability analysis were conducted to investigate the validity of measurement tool and evaluate the reliability. Moreover, the regression analysis between variables and regression analysis were utilized. The results found the following: First, in terms of life stress, as peer relationship, appearance stress, economic stress, family relationship stress and academic stresses decreased, their academic satisfaction increased. Second, regarding cultural adaptation stress, as interpersonal and living culture stresses were lowered, academic satisfaction increased. Therefore, this study targets to derive implications on an efficient plan to improve the academic satisfaction of Chinese students studying in the Republic of Korea by developing and providing a proper academic program with a decent support system in terms of culture, life, and education after investigating their life and cultural adaptation stresses.

ECG Signal Compression based on Adaptive Multi-level Code (적응적 멀티 레벨 코드 기반의 심전도 신호 압축)

  • Kim, Jungjoon
    • Journal of the Korean Institute of Intelligent Systems
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    • v.23 no.6
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    • pp.519-526
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    • 2013
  • ECG signal has the feature that is repeated in a cycle of P, Q, R, S, and T waves and is sampled at a high sampling frequency in general. By using the feature of periodic ECG signals, maximizing compression efficiency while minimizing the loss of important information for diagnosis is required. However, the periodic characteristics of such amplitude and period is not constant by measuring time and patients. Even though measured at the same time, the patient's characteristics display different periodic intervals. In this paper, an adaptive multi-level coding is provided by coding adaptively the dominant and non-dominant signal interval of the ECG signal. The proposed method can maximize the compression efficiency by using a multi-level code that applies different compression ratios considering information loss associated with the dominant signal intervals and non-dominant signal intervals. For the case of long time measurement, this method has a merit of maximizing compression ratio compared with existing compression methods that do not use the periodicity of the ECG signal and for the lossless compression coding of non-dominant signal intervals, the method has an advantage that can be stored without loss of information. The effectiveness of the ECG signal compression is proved throughout the experiment on ECG signal of MIT-BIH arrhythmia database.

Building a Traffic Accident Frequency Prediction Model at Unsignalized Intersections in Urban Areas by Using Adaptive Neuro-Fuzzy Inference System (적응 뉴로-퍼지를 이용한 도시부 비신호교차로 교통사고예측모형 구축)

  • Kim, Kyung Whan;Kang, Jung Hyun;Kang, Jong Ho
    • KSCE Journal of Civil and Environmental Engineering Research
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    • v.32 no.2D
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    • pp.137-145
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    • 2012
  • According to the National Police Agency, the total number of traffic accidents which occurred in 2010 was 226,878. Intersection accidents accounts for 44.8%, the largest portion of the entire traffic accidents. An research on the signalized intersection is constantly made, while an research on the unsignalized intersection is yet insufficient. This study selected traffic volume, road width, and sight distance as the input variables which affect unsignalized intersection accidents, and number of accidents as the output variable to build a model using ANFIS(Adaptive Neuro-Fuzzy Inference System). The forecast performance of this model is evaluated by comparing the actual measurement value with the forecasted value. The compatibility is evaluated by R2, the coefficient of determination, along with Mean Absolute Error (MAE) and Mean Square Error (MSE), the indicators which represent the degree of error and distribution. The result shows that the $R^2$ is 0.9817, while MAE and MSE are 0.4773 and 0.3037 respectively, which means that the explanatory power of the model is quite decent. This study is expected to provide the basic data for establishment of safety measure for unsignalized intersection and the improvement of traffic accidents.

Effects of Relational and Mandatory Influence Strategies on Sales Representatives and Headquarter Trust (관계적과 강제적 영향전략이 본사 신뢰에 미치는 영향 : 영업사원 신뢰의 매개역할)

  • Lee, Chang-Ju;Lee, Phil-Soo;Lee, Yong-Ki
    • Journal of Distribution Science
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    • v.14 no.6
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    • pp.53-63
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    • 2016
  • Purpose - This study examines the effects of the influence strategies on sales representative and headquarter trust, and investigates how sales representative trust plays a mediating role in the relationship between influence strategies and headquarter trust. For these purposes, a structural model which consists of several constructs was developed. In this model, influence strategies that consist of relational influence strategies (information exchange, recommend, promise) and mandatory influence strategies (legal plea, request, threat) were proposed to affect the sales representative trust and in turn, increase the headquarter trust. Thus, this study proposed that sale representative trust plays a core mediating role in the relationship between relational and mandatory influence strategies and headquarter trust in B2B food materials distribution context. Research design, data, and methodology - For these purposes, the authors collected the data from 208 B2B specialized complex agents. We used the 2,200 B2B specialized complex agents which trade with CJ, Ottogi, and Daesang firms and supply food materials to restaurant, school cafeteria, supermarket and traditional market as a sample frame. Once we identified 330 B2B specialized complex agent owners, CEOs, and/or Directors who had agreed to participate in this study, we dropped off a questionnaire at each B2B specialized complex agent and explained the purpose of this study. The survey was conducted from October 1, 2015 to December 15, 2015. A total of 230 questionnaires were collected. Of these collected questionnaires, 28 questionnaires excluded since they had not been fully completed. The data were analyzed using frequency test, reliability test, measurement model analysis, and structural equation modeling with SPSS and SmartPLS 2. Results - First, information exchange, recommendation, and promise of relational influence strategies had positive effects on sales representative trust. The threat of mandatory influence strategies had a negative effect on sales representative trust, but legal plea and request did not have a significant effect on sales representative trust. Second, information exchange and recommendation of relational influence strategies had positive effects on headquarter trust, but promise did not. Also, legal plea, request, and threat of mandatory influence strategies did not have a significant effect on headquarter trust. Third, this findings show that sales representative trust plays a partial mediator between information exchange and headquarter trust, and threat and headquarter trust, and a full mediator between promise and headquarter trust, and recommendation and headquarter trust. Conclusions - The aim of this study was to examine the effects how diverse dimensions of relational and mandatory influence strategies relate to sales representative trust and headquarter trust. To do so, we integrated the influence strategies and the trust transfer theory to hypothesize that various influence strategies increase sales representative and headquarter trust. The findings of this study suggest that headquarter firms should establish and enforce proper influence strategies guidelines to make clear what proper actions sales representatives should implement in relationship with B2B specialized complex agents. Also, relational and mandatory influence strategies must be regarded as a long-term and ongoing strategy that eventually build a long-term orientation with B2B specialized complex agents and guarantee a company's sustainable growth and success.

An Analysis of Purchase Behaviors of Department Store Users based on Types of Preference for Luxury Brands (백화점 이용고객의 명품브랜드 선호도 유형에 따른 구매행태 분석)

  • Sun, Zhong-Yuan;Na, Seung-Hwa
    • Journal of Distribution Science
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    • v.11 no.10
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    • pp.5-15
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    • 2013
  • Purpose - With the increase in fervor to purchase luxury brands, new social problems have arisen, such as excessive preoccupation with luxury brands and high preference for forged luxury goods. Therefore, the issues related to luxury brands, termed "Luxury Syndrome," have emerged as an area of great interest for researchers and practitioners. However, previous studies neglect to categorize this preference for luxury brands. Therefore, this study aims to identify the different purchasing behaviors of consumers using the types of luxury brands preferences as parameters. Research design, data, and methodology - This study arranges a causal relationship model assuming that purchase behaviors positively (+) affect typified preference for luxury brands and purchase intentions. We administered a questionnaire survey to the purchasers who bought luxury brands from department stores to secure additional data necessary to verify the hypotheses in this study. We then processed the data using SPSS 19.0. We further analyzed the basic data using frequency and descriptive statistical analysis, and verified the measurement tools through feasibility and reliability analyses. Moreover, this study uses multiple regression analysis to verify the hypotheses. Further, this study tests the path effect between luxury brand purchase attitude and purchase behavior, with non-intrinsic preference and intrinsic preference as the mediating variables. Results - Based on the results, the impact of tendencies of conspicuous consumption and self-monitoring on non-intrinsic preference was significantly positive (+), while the impact of tendencies of pursuit of a reference group, conspicuous consumption, and self-monitoring on intrinsic preference and purchase intentions was significantly positive (+). Further, non-intrinsic and intrinsic preferences positively (+) influence purchase intentions and the impact of non-intrinsic preference took an absolute portion. However, the tendency of dependence on brands negatively (-) impacts purchase intentions. The results showed that self-monitoring and conspicuous consumption tendencies have greater effect on purchase intention, which is mediated by non-intrinsic preference. In contrast, reference group following tendency has a greater effect on purchase intention, which is mediated by intrinsic preference. Conclusions - Based on the results, the study verifies that the consumption of luxury brands in Korea has not yet entered the settling period. The tendency for conspicuous consumption and the tendency for pursuit of the reference group were relatively important aspects for the consumers who prefer luxury brands non-intrinsically and intrinsically, respectively. Especially, it was found that the purchase intentions for forged brands originate from the tendency to depend on brands. Based on these findings, this study suggests the measures to develop and mature the luxury brands market, and reinforce marketing performance at the three levels, that is, government, distributors, and manufacturers. The luxury brands manufacturers should devote themselves to the production and design of products to catch the attention of mature consumers of luxury brands. The luxury brands distributors should then raise the level of Customer Relationship Management (CRM) for opinion leaders. Finally, the Government should prepare effective policies for the development of luxury brands and provide a variety of economic support.